Neurosoft Neuro-Audio-Screen/OAE, Neuro-Audio-Screen Technical Manual

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Technical Manual

Neuro-Audio-Screen Neuro-Audio-Screen/OAE

Portable All-in-One ABR, DPOAE&TEOAE Hearing Screening Systems

TM057.02.002.00

Neurosoft Ltd. © 2013 5, Voronin str., Ivanovo, 153032, Russia P.O. Box 10, Ivanovo, 153000, Russia Phone: +7 (4932) 24-04-34 Fax: +7 (4932) 24-04-35 E-mail: com@neurosoft.ru Internet: www.neurosoft.ru

Table of Content

Introduction............................................................................................................... 5

List of Abbreviations ................................................................................................ 6

1. Important Safety Instructions ........................................................................... 7

2. Description and Operation................................................................................ 9

2.1. Neuro-Audio-Screen Function....................................................................... 9

2.1.1. Otoacoustic Emission and its Recording............................................... 9

2.1.2. Auditory Brainstem Response and Its Recording................................ 10

2.2. Main Specifications..................................................................................... 11

2.3. Arrangement and Operation........................................................................ 14

3. Description and Delivery Set .......................................................................... 16

4. Mounting and Setting...................................................................................... 19

4.1. Unpacking and Check of Delivery Set......................................................... 19

4.2. Room Selection and Placement.................................................................. 19

4.3. Requirements to the Personnel Conducting Mounting and Setting.............. 19

4.4. Getting Started............................................................................................ 20

5. Functioning...................................................................................................... 21

5.1. Control and Indication Tools ....................................................................... 21

5.1.1. Control Buttons................................................................................... 21

5.1.2. Indication............................................................................................ 22

5.1.2.1. Display Means ........................................................................... 22

5.1.2.2. Displaying of Main Parameters .................................................. 22

5.1.3. Connectors......................................................................................... 24

5.2. Turning on .................................................................................................. 25

5.3. Rechargeable Battery Charge..................................................................... 25

5.4. Entering of Personal Data of New Patient, Selection of Patient from

Database, Removal of Patient Data............................................................ 29

5.5. Patient Preparation for OAE Test................................................................ 31

5.6. TEOAE Test ............................................................................................... 34

5.7. DPOAE Test............................................................................................... 37

5.8. Patient Preparation for ABR Test................................................................ 40

5.9. ABR Test .................................................................................................... 41

5.10. Review, Printing and Removal of Results ................................................. 44

5.10.1. Review and Printing of Test Results................................................. 45

5.10.2. Removal of Test Results................................................................... 48

5.10.3. TEOAE Report Description............................................................... 49

5.10.4. DPOAE Report Description .............................................................. 50

5.10.5. ABR Report Description.................................................................... 52

6. Settings ............................................................................................................ 53

6.1. General Settings......................................................................................... 55

6.2. TEOAE Settings.......................................................................................... 56

6.3. DPOAE Settings ......................................................................................... 57

6.4. ABR Settings .............................................................................................. 59

6.5. System Settings.......................................................................................... 60

7. Data Exchange with Computer ....................................................................... 65

7.1. Screening System Connection to Computer ............................................... 65

7.2. Operation with Neuro-Audio-Screen Manager Software.............................. 69

7.2.1. Receiving of Patient List and Exams .................................................. 72

7.2.2. Operation with Saved Exams ............................................................. 74

7.2.3. Exam Review and Print ...................................................................... 75

7.2.4. Operation with Patients List................................................................ 75

7.2.5. Service Functions............................................................................... 78

7.2.6. Firmware Updating ............................................................................. 79

8. Troubleshooting .............................................................................................. 82

9. Technical Servicing......................................................................................... 84

9.1. General Requirements................................................................................ 84

9.2. Maintenance Works.................................................................................... 84

9.3. Cleaning and Desinfection.......................................................................... 84

9.4. Device Functioning Check Using Test Cavity.............................................. 85

9.5. OAE Probe Check ...................................................................................... 86

9.6. Conservation .............................................................................................. 90

10. Packing and Transportation ........................................................................... 90

11. Storage Regulations........................................................................................ 91

12. Utilization of Neuro-Audio-Screen and Neuro-Audio-Screen/OAE............... 91

13. Delivery Set and Package Data....................................................................... 91

14. Acceptance Certificate.................................................................................... 92

15. Delivery Certificate .......................................................................................... 92

16. Storage Data .................................................................................................... 92

17. Warranty........................................................................................................... 93

18. Reclamation Data ............................................................................................ 94

19. Repair Data ...................................................................................................... 96

Annex 1. Electromagnetic Emission and Immunity.............................................. 97

Annex 2. Format of Neuro-Audio-Screen Exported Files................................... 101

Introduction

This technical manual (hereinafter referred to as “manual”) is the combined document describing the operation and the servicing of Neuro-Audio-Screen portable all-in-one ABR, DPOAE&TEOAE hearing screening system (hereinafter referred to as screening systems) intended for the hearing examination of human being including the newborns using otoacoustic emission and auditory brainstem response techniques.

The manual is the document certifying the technical parameters of the products which are guaranteed by the manufacturer.

Read carefully this technical manual before starting to work!

You can send your responses and recommendations to the following address:

Introduction

P.O. Box 10, Ivanovo, 153000, Russia

or by e-mail:

help@neurosoft.ru.

You can find additional information on Neurosoft products in the Internet:

www.neurosoft.ru

or ask questions by phones:

+7 (4932) 24-04-37 (Service department),

+7 (4932) 24-04-34.

Hearing Screening Systems (Technical Manual)

List of Abbreviations

ABR – auditory brainstem response

BERA – brainstem evoked response audiometry

DPOAE – distortion product evoked otoacoustic emission

IHC – inner hair cells

LCD – liquid-crystal display

OAE – otoacoustic emission

OHC – outer hair cells

SPL – sound pressure level

TEOAE – transient evoked otoacoustic emission

1. Important Safety Instructions

Neuro-Audio-Screen and Neuro-Audio-Screen/OAE is designed to be used only by

those individuals trained to perform the testing for which it has been designed. No person should attempt to use these hearing systems without the necessary knowledge and training to understand how this equipment is to be properly utilized and interpreted.

The hearing system probe must not be inserted into an ear without an ear tip properly affixed.

The hearing systems do not contain high-voltage circuits inside which can represent a danger for a human being. The hearing systems ensure the safe operation at the correct exploitation. However, the number of precautions at the hearing systems use exists:

Important Safety Instructions

 Do not discharge the battery completely. When storing the discharged Li-ion battery

degrades fast over time.

 Do not immerse the device in water or any other solutions (for example, do not

leave it near the aquarium in the presence of a child). See the device cleaning procedures in section 9 “Technical Servicing” of this manual.

 Use and store the instrument indoors only. Do not expose this device or its

accessories to temperatures below 5ºC or above 40ºC, or to relative humidity of more than 90%.

 Do not drop or otherwise cause undue impact to this device. If the screening

system is dropped or otherwise damaged, return it to the manufacturer for repair and/or calibration. Do not use the screening system if any damage is suspected.

 Do not attempt to open or service the screening system. Return the device to the

manufacturer or send to the company authorized by the manufacturer for all service. Opening the screening system case will void the warranty.

 Do not operate the printer if the power supply has a damaged cord or plug.

 Do not expose the printed results to sunlight or heat. Printing on thermal paper

fades with exposure to light or heat.

 Photocopies of test results should be made if the records are to be kept indefinitely.

 The equipment and accessories used together with the device should satisfy the

requirements stated in the present manual (table 2 and table 3 “Document code or main specifications” column). The violation of this requirement can impact negatively the electromagnetic compatibility (result in the increase of emissions or reduction of immunity) and also the safety and functioning of the screening system.

Hearing Screening Systems (Technical Manual)

Precautions at Operation with Printer and Screening System AC Power Supply

The power supply unit of Neuro-Audio-Screen and Neuro-Audio-Screen/OAE screening systems transforms the mains voltage (220/230 V 50/60 Hz) into the direct voltage (9 V) and is intended for the charge of the rechargeable battery built in the device and the screening system power supply only in case the battery is discharged. The printer power supply unit is used ONLY for the printer power supply and has the specifications differing from the Neuro-Audio-Screen and Neuro-Audio-Screen/OAE power supply unit. The connector of printer power supply unit of different manufacturers can coincide with the device power supply connector. It can cause a mistake at the power supply unit connection that is why, please, be attentive. The use of the printer power supply unit for the supply of Neuro-Audio- Screen and Neuro-Audio-Screen/OAE screening systems can result in the device failure and the rechargeable battery outage.

 Do not connect the printer power supply unit to Neuro-Audio-Screen and

Neuro-Audio-Screen/OAE screening systems.

 It is prohibited to use the power supply of other type and manufacturer to supply the

device as it can result in the device failure or a patient’s electrical shock.

 The power supply is intended for the operation from the AC power supply with

220/230 V 50/60 Hz voltage, do not insert the unit into the 380/400 V outlet.

 The power supply is for indoor use only. Do not expose to water or excessive dust.

 The power supply is not intended for the operation in the presence of the highly

inflammable mixture of anesthetics with an air or nitrous oxide.

Do not cover the power supply body as it may result in excessive heating. The power supply operates when the plug is inserted into an outlet. To turn it off, remove the plug from the outlet. The outlet must be easily accessible and located near the printer. Should a faulty condition occur, remove the plug from the outlet immediately.

2. Description and Operation

2.1. Neuro-Audio-Screen Function

The Neuro-Audio-Screen and Neuro-Audio-Screen/OAE hearing screening

systems are intended for the objective audiometry.

The devices can be applied in patient care institutions, diagnostics centers, maternity

hospitals, neuro-surgical clinics and experimental laboratories of the research

institutions for:

 the study of the auditory brainstem response (ABR) (only Neuro-Audio-Screen)

(also known as brainstem evoked response audiometry (BERA));

 the study of the otoacoustic emission (OAE) using TEOAE and DPOAE techniques.

Description and Operation

The screening systems allow choosing a exam type, entering a patient’s data, controlling

a exam process, results displaying and a recorded exams database. It is possible to

process and archive the exam results on the computer, print them using the printer

connected via the wireless interface.

2.1.1. Otoacoustic Emission and its Recording

What is TEOAE?

Transient evoked otoacoustic emission (TEOAE) is an acoustic signal that can be

detected in the ear canal of a person with normal outer hair cell (OHC) function,

subsequent to stimulation of the auditory system with a series of wideband clicks.

What is DPOAE?

Distortion product otoacoustic emission (DPOAE) is an acoustic signal that can be

detected in the ear canal of a person with normal outer hair cell function, subsequent

to stimulation of the auditory system with a pair of pure tones at frequencies f1 and f2.

The resulting emission of interest is the distortion product tone at the

frequency 2 f1-f2.

What Do Otoacoustic Emission Results Tell Us?

Available evidence suggests that otoacoustic emission (OAE) is generated by the

cochlea’s outer hair cells, and that the presence of OAE is an indication that the outer

hair cells are normal. Although OAE test data provide no indication of inner hair cell

(IHC) function, or of hearing ability, current research indicates that the majority of

hearing-impaired individuals will be identified by a simple OAE test. Patients who fail

to generate OAE should be re-screened and/or referred for additional audiological

testing.

Hearing Screening Systems (Technical Manual)

How Does Screening Systems Record TEOAE?

The Neuro-Audio-Screen and Neuro-Audio-Screen/OAE screening systems gener-

ate a series of clicks using a telephone, direct them into the ear canal, and then

average the response received by the microphone built in the probe recording OAE.

Owing to the use of the fast Fourier transform for the spectral analysis and the

bandpass filters, the devices provide an estimate of outer hair cell function over a

wide range of frequencies.

How Does Screening System Record DPOAE?

The Neuro-Audio-Screen and Neuro-Audio-Screen/OAE screening systems

generate a series of test tones using two telephones, direct them into the ear canal,

and then measure the level of the DPOAE tone generated by the cochlea by the

microphone built in the probe. By using different test frequencies, the devices provide

an estimate of outer hair cell function over a wide range of frequencies.

2.1.2. Auditory Brainstem Response and Its Recording

What is ABR?

Auditory brainstem response (ABR) is an electrical signal recorded from the

electrodes placed on the head of a patient with the normally functioning organs of

hearing including the auditory nerve and projection areas of the cerebral cortex. This

signal is the result of the auditory analyzer stimulation by the series of the auditory

pulses.

What Do ABR Test Results Tell Us?

As far as ABR is generated by the cochlea, the auditory nerve and the projection

areas of the cerebral cortex, we can safely say that the ABR presence indicates the

normal functioning of all the above mentioned auditory system parts and a patient

hears an acoustic signal directed to the ear canal.

How Does Neuro-Audio-Screen Screening System Record ABR?

The Neuro-Audio-Screen screening system generates a series of clicks using a

telephone, directs them into the ear canal, and then averages the electrical signal

received from the electrodes placed on a patient’s head. As a result ABR is obtained.

Owing to the high frequency of stimulus delivery (up to 93 Hz), the device can register

the so called steady-state potentials. These potentials differ in the high amplitude, are

easily and quickly separated, practically not influenced by the external

electromagnetic fields.

2.2. Main Specifications

Table 1. The Screening System Specifications

Parameters Values

ABR Technique

Recorded EP range 0.15–900 µV

Common-mode rejection not less than 100 dB

Noise level (rms) not more than 0.35 µV

Amplifiers input impedance not less than 90 MΩ

Amplifiers input capacity not more than 40 pF

Description and Operation

Differential input bias voltage, maximum permissible

Bandpass flatness in the range from 200 up to 3000 Hz

Electrode impedance range 0.5–500 kΩ

Stimulus intensity range for OAE probe 0-60 dB HL

Stimulus intensity range for TDH-39 headphones 0–100 dB HL

Stimulation frequency range 9–93 Hz

TEOAE Technique

Frequency range 400–5000 Hz

Stimulus intensity range 50–90 dB SPL

Stimulus spectrum flatness

 in the frequency range 0.5–2.5 kHz  in the frequency range 0.5–5 kHz

Noise level in the frequency range 500–5000 Hz not more than 30 dB SPL

DPOAE Technique

Frequency range 0.5–12 kHz

Stimulus intensity range 30–75 dB SPL

Stimulus 3rd order intermodulation not more than -80 dB

(30030) mV

-305%

with 1 Hz step

not more than 10 dB not more than 20 dB

General Parameters and Specifications

Automatic result analysis yes

Indication of probe setting quality yes

Number of measurements saved in a device memory:

 TEOAE  DPOAE  ABR

Number of patient cards saved in device memory:

 TEOAE  DPOAE  ABR

Operating time of electronic unit at rechargeable battery use from 7 up to 10* hours

LCD 3.5" with resolution not less

from 320 up to 1000

from 260 up to 700

from 1300 up to 4000

from 320 up to 500 from 260 up to 350

from 1300 up to 2000

than 640480

Hearing Screening Systems (Technical Manual)

Table 1. Continued

Parameters Values

Interface Bluetooth

Electronic unit power supply voltage from external power supply

unit

Safety BF

Protection class from electrical shock 1

Electronic unit dimensions

Electronic unit weight not more than 0.68 kg

Total weight not more than 2 kg

Power supply:

 rechargeable battery

 power supply unit:

 model  supply voltage  output voltage

Note:

* depending on the operation mode of the device.

Safety and Electromagnetic Compatibility

(19510155)2 мм

Li-ion with 4400 mAh

100–240 V, 50/60 Hz, 0.8 A

9 V

capacity

PSU-9

9 V DC

Electromagnetic compatibility (EMC) is provided by IEC 60601-1-2:2007 requirements

fulfillment.

The screening systems are intended for operation in the electromagnetic environment

conditions which are specified in the appendix 1 “Electromagnetic Emission and

Immunity”.

Portable and mobile RF communication equipment may affect the system work.

The use of the equipment not listed in table 2 and table 3 of the present technical

manual may result in increased emission and system decreased immunity.

As for safety, screening systems satisfy IEC 60601-1:1988 + A1:1991 + A2:1995, IEC

60601-1-1:2000, IEC 60601-2-40:1998 standards requirements. The devices are

supplied by the external power supply unit of 9 V direct voltage or Li-ion rechargeable

battery, are related to class I and have BF type work parts according to IEC 60601-1.

All the computer equipment used together with the devices should correspond to IEC

60950-1 and CISPR 22:2006.

Interpretation of symbols on the electronic unit:

- attention: consult user and technical manuals.

- work parts of BF type according to IEC 60601-1.

Description and Operation

- mark of conformance to Russian standards requirements.

- mark of conformance to 93/42/EEC “Concerning Medical Devices” directive.

- mark of conformance to 2002/96/EC “On waste electrical and electronic equipment (WEEE)” directive.

Hearing Screening Systems (Technical Manual)

2.3. Arrangement and Operation

The screening system is intended for the performing of two test types: OAE and ABR.

The principle of operation at OAE performing is based on the registration of the

auditory fluctuations of the cochlea OHC with the use of the probe microphone, in

response to the auditory stimulation with the use of the telephones built in the probe.

The principle of operation at ABR performing is based on the registration of the brain

electrical response in reply to the auditory stimulation.

The functional scheme of Neuro-Audio-Screen screening system is presented in

the Fig. 1.

Bluetooth module

Biopotentials

electrodes

Probe microphone

Probe telephones

Headphones

Fig. 1

PU amplifier

Microphone

amplifier

Telephone

amplifier

ADC

DAC

CPM

Secondary power

supply source

Rechargeable

batteries

LCD

Keyboard

External power

supply +9 V

In the OAE test mode, the central processor module (CPM) generates the test signal

in a digital form and transfers it to the digital-to-analogue converter (DAC). The DAC

converts the signal to the analogue form and directs to the amplifier. After that, the

signal from the amplifier is transferred to the OAE probe telephones where it is

converted to the acoustic stimulus. The acoustic response of the cochlea OHC is

registered by the probe microphone and is converted to the electrical signal. Via the

microphone amplifier this signal is transferred to the analogue-to-digital converter

(ADC) input where it is converted to the digital form. The digitized response is directed

to CPM where it is processed and analyzed. The report concerning the test results is

based on the CPM analysis.

In the ABR test mode, the device operates in the same way. CPM generates the test

signal which is converted into the analogue form when transferring via the DAC, is

amplified by the amplifier and is directed either to the OAE probe telephones or to the

Description and Operation

headphones depending on what is used as an auditory stimulator. The brain electrical

response is recorded from the electrodes, directed to the biopotentials amplifier input

and then amplified. After that, it is transferred to the ADC, converted to the digital form

and directed to CPM. CPM processes and analyzes the received response and gen-

erates the report concerning the test results.

Except the above-mentioned functions, CPM controls completely the device

operation, keeps the settings and test results, displays the test procedure, test results,

service information using the LCD display. To transfer the results to the computer or

thermal printer and also to download the list of patients from the computer, CPM uses

Bluetooth module which provides the implementation of the Bluetooth wireless

interface. CPM is controlled by a user from a keyboard.

To provide the required supplying voltages for all the scheme units, the secondary

power supply source is provided. It can operate both from the built-in rechargeable

battery and external power supply. In the last case it provides the charge of the built-in

rechargeable battery.

Hearing Screening Systems (Technical Manual)

3. Description and Delivery Set

Neuro-Audio-Screen and Neuro-Audio-Screen/AOE screening systems are pocket

devices developed for the performing of the objective test of the auditory function. It

consists of the portable unit to which the OAE probe and electrodes for ABR recording

can be connected, the software for the data downloading from the device to the PC,

wireless thermal printer with Bluetooth interface for the printing of the tests results (is

not included in the base delivery set), set of ear tips and other accessories.

The delivery sets of Neuro-Audio-Screen and Neuro-Audio-Screen/AOE screening

systems are presented in the Table 2 and Table 3 (1 and 2 columns correspondingly).

Table 2. Base Delivery Set

Name

Neuro-Audio-Screen electronic unit

Neuro-Audio-Screen/OAE electronic

unit

Power supply unit PSU-9 NSFT 057201.009 1 1

Power cord SCZ-1 (1.5 m.) 1 1

Bluetooth adapter1) 100 m, class 1, V.2.1, CSR chipset 4 4

Accessories for EP and OAE Studies

Cable for reusable electrodes

connection

OAE probe 2) NSFT 006355.003-00

Set of OAE probe tips ER10D-RPT

Set of ear tips (pediatric) NSFT 007998.001 SP 1 1

Cable for disposable electrode

connection:

Alligator clip – touch-proof

(green, red or black)

Document code or main

specifications

NSFT 057201.015 1 –

NSFT 057201.016 – 1

NSFT 057103.003-05 1 –

OAE-02-2

NSFT 006355.003-01

OAE-02-2

NSFT 006221.001

NSFT 990103.027-02.05 NSFT 990103.027-03.05 NSFT 990103.027-04.05

Number, pcs.

1 2

1 1

1 1 1

–

Disposable surface electrode (100

pcs.) 1)

Test cavity NSFT 006201.013 1 1

Screw driver №1 GOST 17199 1 1

Dental floss Regular Oral-B (pack –

50 pcs)

Probe tip extractor NSFT 006206.016 1 1

F3081, F3001 3

pack.

Oral-B, Ireland

–

1 1

Table 2. Continued

Description and Delivery Set

Name

Document code or

main specifications

Number, pcs.

1 2

Operational Documentation

Neuro-Audio-Screen,

Neuro-Audio-Screen/OAE technical manual

Neuro-Audio-Screen, Neuro-Audio-

Screen/OAE calibration guidelines

OAE probe guidelines

Video manual on CD Version not lower than

TM057.02.002.000 1 1

CG057.01.001.000 1 1

GL032.03.001.000 1 1

001

1 1

Software

Neuro-Audio-Screen manager software

without additional

modules

1 1

Package

Transportation bag - 1 1

Note:

The accessories and consumables of analogous types can be applied, but their use should

be permitted in the country.

OAE probe NSFT 006355.003-01 is supplied with probe tip NSFT 006221.001, and OAE

probe NSFT 006355.003-00 is supplied with probe tip ER10D-RPT.

Table 3. Additional Equipment, Accessories and Software

Name Document code or main specifications

Number, pcs.

1 2

Accessories for EP and OAE Studies

Auditory stimulator

(headphones)

Insert earphones for

NSFT 032305.005 (TDH-39)

NSFT 015305.001 (TA-01)

ER3-10 1 –

1 –

audiometry

Set of disposable foam ear tips ER3-14A, ER3-14B, ER3-14D2, ER3-14C,

1 –

ER3-14E2

Adapter for earphones for

NSFT 032103.004 1 –

audiometry

Cup EP electrode with cable

(green, red, black) 1)

NSFT 990106.028-02.05 (F8909Z)

NSFT 990106.027-02.05 (EEP)

NSFT 990106.028-03.05 (F8909Z)

NSFT 990106.027-03.05 (EEP)

1 –

NSFT 990106.028-04.05 (F8909Z)

NSFT 990106.027-04.05 (EEP)

1 –

Hearing Screening Systems (Technical Manual)

Table 3. Continued

Name

Document code

or main specifications

Number, pcs.

1 2

Consumables

Electrode adhesive paste

Electrode abrasive paste

for skin preparation 1)

TC 9398-011-34616468-2002

Unipasta, 120 g

Everi, Italy, 160 g. 1

Software

Neuro-Audio.NET

version not less than 1.0.6.0 1 1

software

Computer and Electronic Equipment 2)

System unit3) TC 4013-003-13218158-2011

1 1

 “Functional”  “Elegant”  “Elite”

Notebook PC Minimal requirements

1 1

according to recommendations

stated in section 7.2

Monitor LCD 19’’ 1 1

Printer for personal

Laser or jet 1 1

computer

–

Printer for electronic unit CUSTOM S’Print BT

1 1

Citizen CMP10 2 Bluetooth

Note:

The accessories and consumables of analogous types can be applied, but their use should

be permitted in the country.

All the computer equipment should conform to IEC 60950-1 and CISPR 22 for B class.

The supply of other computer with the same or better specifications is allowed (see section

7.2).

The appearance of Neuro-Audio-Screen screening system with all the accessories

included in the base delivery set is shown in the Fig. 2.

Fig. 2. The appearance of Neuro-Audio-Screen screening system and accessories.

4. Mounting and Setting

4.1. Unpacking and Check of Delivery Set

If the box with screening system was under conditions of the excessive moisture or

low temperature which differs sharply from working conditions, it is necessary to place

it in the room and leave for 24 hours in normal conditions.

Unpack the box, extract the screening system and the components. The delivery set

should correspond to the report concerning the device packing.

The computer equipment packed in the separate boxes should be opened according

to user and technical manuals for these products.

Check screening system and components to make sure that there are no external

damages.

Mounting and Setting

4.2. Room Selection and Placement

The Neuro-Audio-Screen and Neuro-Audio-Screen/OAE screening systems are

portable devices that is why its exploitation is allowed in any rooms of patient care

institutions where the temperature and the humidity of the environment corresponds to

the conditions described in the device specifications. Also it is allowed to use the

device for the exam performing at patient’s place.

The room for OAE studies performing should be free from the noise sources such as electrical motors, powerful ventilators, electric kettles, audio equipment, aquarian compressors, etc.

4.3. Requirements to the Personnel Conducting Mounting and Setting

There are no special requirements to the personnel conducting screening system mounting and setting.

The replacement of the rechargeable battery must be performed in the service centers of Neurosoft Company.

Hearing Screening Systems (Technical Manual)

4.4. Getting Started

The offered sequence of operations will allow you to speed up the use of Neuro-Audio-Screen screening system for OAE recording. The operating order of ABR test performing is described in section 5.8 “Patient Preparation for ABR Test” and section 5.9 “ABR Test”. The first four steps are fulfilled in any case regardless of the used technique.

First of all perform the otoscopic study prior to testing. Read carefully this technical manual before you start to examine the patients.

Step 1. Connect the power supply unit to charge the battery. The battery is charged for 3-4 hours (see section 5.3 “Rechargeable Battery Charge”).

Step 2. Connect the OAE probe to the screening system. Place the ear tip as far down as possible on the OAE probe tip.

Step 3. Switch on Neuro-Audio-Screen by pressing on/off button for 2 seconds.

Step 4. After screening system loading, set the printer type and address if you have

wireless thermal printer. Enter the OAE probe sensitivity, date and time. Set the report type. The detailed procedure is described in section 6.5 “System Settings”.

Step 5. Insert the ear tip deeply into the patient’s ear canal to obtain a seal. The order of OAE probe insertion into the ear canal is described in section 5.5 “Patient Preparation for OAE Test”. Choose the technique and the tested ear with the use of “up/down” buttons and “Select” key.

Step 6. First, Neuro-Audio-Screen checks the quality of OAE probe setting, performs calibration automatically and then fulfills OAE recording. At high noise level the noise level indicator highlights red. This is normal and it takes place quite often. Anyway the study can be performed if the indicator does not glow red constantly, however it impacts the final result of the recording. Once the test is finished, the test result is displayed on the screen (PASS/REFER).

Step 7. After the test finishing, you can save the results in the screening system memory by pressing “Close” button and answering “Yes” to the question “Save exam?”. If you have printer, you can print the results. Switch on the printer by pressing the round button on top. Press “Print” button on the screening system. The results of the current exam will be printed.

5. Functioning

2 1

5.1. Control and Indication Tools

5.1.1. Control Buttons

The front panel of Neuro-Audio-Screen and Neuro-Audio-Screen/OAE screening systems contains the following control buttons (Fig. 3).

Functioning

Fig. 3. The front panel of Neuro-Audio-Screen and Neuro-Audio-Screen/OAE screening system (1).

1. On/Off button.

2. Four multifunctional buttons. They are used for the selection of the menu items,

the entering of the personal patient’s data, the printing of the results, the performing of the tests, the saving of the exams, the reviewing of the test results, etc. The function of each button varies depending on the current operation mode (the exam, the review, etc.) and is displayed in the text line straight above the button. Further in the text the denotation of these buttons indicated in the text line will be used in this manual, for example: Press the “Close” button. It means that it is necessary to press the multifunctional button above which at present moment the text “Close” is displayed. The text line will be further named “active menu”.

3. The arrow buttons are for the shifting right-left, up-down and the selection button

in the center. The buttons are intended for the moving over the menu items and

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choosing the menu item, the text typing, the settings change. The denotations “left”, “right”, “up”, “down”, “Select” will be used further in the text.

5.1.2. Indication

5.1.2.1. Display Means

The front panel of Neuro-Audio-Screen and Neuro-Audio-Screen/OAE screening systems contains the following display means (Fig. 4).

Fig. 4. The front panel of Neuro-Audio-Screen and Neuro-Audio-Screen/OAE screening systems (2).

1. TFT LCD display. It is used for the displaying of the menu, the settings, the exam

procedure and results, the additional information (battery condition, free space, Bluetooth mode (on/off) and the text line (the function of multifunctional buttons)).

2. The indicator of the rechargeable battery charge. The indicator does not light up if

the power supply unit is not connected to the device, glows green in case the battery is completely charged and glows yellow if the charging is taking place.

5.1.2.2. Displaying of Main Parameters

The indicator of the rechargeable battery charge operates in one of four modes:

1. The indicator is damped. It means that the device is either switched off or

operates from the built-in rechargeable battery.

2. The indicator glows green. This mode is activated when the device operates from

2 3 4

the power supply unit after the rechargeable battery charge termination.

3. The indicator glows yellow. It means that the rechargeable battery is being

charged. It is displayed when the device is supplied from the power supply unit.

The following message information is displayed on the LCD screen (Fig. 5).

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Fig. 5. The displaying of the message information.

1. The condition of the rechargeable battery as a sign with three segments. At

the completely charged rechargeable battery all the three segments are displayed. During the battery discharge the number of the displayed segments lessens.

2. The icon of Bluetooth technology. It means that the connection via the wireless

channel is activated at the present moment.

3. The letter “M” and the numerical value. It corresponds to the free space in the

percents left on the disk for the storage of the exam data.

4. The active menu line. The function of each of the four multifunctional buttons at

the present moment of time is displayed here.

The main part of LCD screen displays the information concerning the current exam or menu items.

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1 2 3

5.1.3. Connectors

The top panel of Neuro-Audio-Screen and Neuro-Audio-Screen/OAE screening systems contains the following connecting jacks (Fig. 6).

Fig. 6. The top panel of Neuro-Audio-Screen screening system.

1. The connector for cable for electrodes connection for Neuro-Audio-Screen (cup

EP electrodes or disposable EP electrodes are attached to this cable) (is absent in Neuro-Audio-Screen/OAE)

2. The connector for OAE probe.

3. The connector for the telephones attachment (is absent in

Neuro-Audio-Screen/OAE). The telephones are not included in the base delivery set and are bought separately. It is allowed to connect the telephones of different manufacturers. The resistance of the telephones should be not less than 10 Ω.

The bottom panel of Neuro-Audio-Screen and Neuro-Audio-Screen/OAE screening systems contains the connector for the power supply unit (Fig. 7).

Fig. 7. The bottom panel of Neuro-Audio-Screen and Neuro-Audio-Screen/OAE screening systems.

5.2. Turning on

To turn on Neuro-Audio-Screen and Neuro-Audio-Screen/OAE screening systems press and hold the device on/off button for about 2 seconds (Fig. 3). If the rechargeable battery has enough capacity, than the screen highlight will switch on in 3 seconds and the message information (the built-in software downloads into the device) will appear on the screen. After that, the main menu window will display on the screen (Fig. 8).

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Fig. 8. The main menu window.

If the device is not switched on at the pressing and holding of the on/off button or is switched off at the buttons release, see the section “Troubleshooting”.

If the rechargeable battery is absent, it is necessary to connect the power supply unit included in the delivery set.

It is prohibited to use the power supply unit of other type and manufacturer. It can lead to the device failure or patient’s electrical shock.

If the device is switched on for the first time, it is necessary to set the date and time (see the section 6 “Settings”). You should also set the printer address and type if you want to use the wireless thermal printer. It is necessary to enter the probe sensitivity (see section 6.5 “System Settings”).

5.3. Rechargeable Battery Charge

The rechargeable battery can be charged in two modes:

1. The device is switched on and used for the exams.

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2. The device is switched off.

It is allowed to charge the battery in both modes. At that, if the device is switched on and is used for the exam performing, the charge process does not impact the measurement accuracy and TEOAE and DPOAE test results.

During the ABR test it is recommended to disconnect the power supply unit from the device to get more reliable test results.

The charge of the battery is required if during the device operation the state of charge is indicated as an empty one. To do this, connect the power supply unit to the connector for the battery charge (see the section 5.1 “Control and Indication Tools”). The connection of the power supply unit is allowed in both above-mentioned modes (the device is switched on and off). After the connection the indicator on the front panel (see the section 5.1 “Control and Indication Tools”) should glow yellow which means the start of the charge procedure. The battery charge procedure lasts for about 3-4 hours. The light increase of the temperature of the battery compartment cover and the whole rear panel is admissible during the charge process. If the device is switched on, the sign with the three segments will display on the screen during the charge process. It does not mean the charge termination, it indicates that the power supply unit is being connected to the device.

The end of the charge process is defined only by the indicator located on the front panel.

After the charge process finishing, the indicator on the front device panel should glow green, what means the successful completion of the charge process. After that, one can disconnect the power supply unit and operate autonomously (for more convenience). It is also allowed to use the device with the connected power supply unit after the finishing of the charge process to prolong the service life of the battery.

If the battery charge is completed successfully (the green indicator highlighted), and you operate on the device supplied from the power supply unit, than in some time (several hours) of the continuous work the indicator will glow yellow. It means that the rechargeable battery is discharged during the operation (at the device supply from the power supply unit, the battery also discharges but much more slowly; it is called self-discharge) and the process of the charger switched to the mode of the battery “subcharge”. In this case the battery will charge automatically, at that the indicator will glow yellow and after the end of the “subcharge” process it will highlight green again.

During the charge process the battery temperature is controlled. If the specified level is exceeded, the charge cycle ends. When the battery temperature falls up to the normal level, the charge cycle renews. It allows charging the battery without close attention of the personnel and leaving the device with the power supply unit connected to the mains for a night. However it is not recommended to leave the device being plugged to the mains for longer periods.

Before starting to use the rechargeable battery, it is necessary to charge it completely.

Battery Capacity at the Delivery

The supplied rechargeable battery is delivered in a partially discharged state, as it takes considerable time from the complete charge at the manufacturer’s plant.

The spontaneous discharge of the rechargeable battery at the room temperature achieves 5% per month. It means that the battery can half discharge in 9-12 months after its complete charge.

Life Time of Rechargeable Battery

The life time of battery is defined by the number of complete “charge-discharge” cycles. In real use conditions the number of cycles varies from 500 to 1000 depending on the discharge depth, at that the battery capacity decreases to 60-80% from the nominal value. The number of cycles corresponds to 2-4 years of real operation (in average, 5-6 “charge-discharge” cycles per week).

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The life time of battery is not indicated. Usually the storage life before the operation start is 2 years.

Important Note Concerning the Correct Use and Charge of Li-Ion Battery

The battery is exposed to wear because of its construction. The life time of the battery depends also on the correct technical servicing. The charge and the discharge are the most important wear-out factors.

As far as the Li-ion battery have no “memory effect”, it is allowed to charge/discharge the battery at any charge level. Though once every several months it is recommended to discharge the device completely, i.e. wait for the device switching off and then charge it completely.

Often complete discharge of the battery is not recommended. If the battery is discharged completely, charge it as soon as possible.

The overcharge is even more harmful for the Li-ion battery than the over-discharge. The controller limits the maximal charge level but there is one peculiarity. It is well known that the battery capacity depends on the temperature. Thus, for example, we charged the battery at the room temperature and obtained 100% charge, the battery charge level may decrease to 80% and more when going out to the frosty weather and device cooling down. The reverse situation may also happen. The battery charged 100% at room temperature may warm to 105% what is rather bad for it. Such situations may occur if the device operates with the connected power supply unit during the longterm period of time. During the operation the temperature of the device and also the battery increase and as far as the charge is complete, the over-charge takes place. That is why if you intend to work with the mains supply, disconnect the device from the

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power supply unit first, work with the device for some time. As soon as the device starts working in an “operating conditions”, connect the power supply unit.

Also it is important to observe the temperature conditions during the battery discharge and especially charge. The optimal ambient temperature during the charge is about 15– 25ºC. Do not allow the device operation if the temperature exceeds 35ºC or goes below 0ºC.

The battery may also self-discharge. This process depends on the environment temperature. If the temperature is high, the battery discharges with higher speed. The high humidity, high temperature and long-term storage also contribute to selfdischarging.

Storage of Li-ion Battery

Li-ion battery should be stored charged. If Li-ion battery is kept with 2.75 V voltage and lower for three months or more, the battery capacity will be lowered greatly. Besides the corrosion of the elements may occur. The recharge of the Li-ion battery is not allowed if the voltage at the element pins dropped below the critical level. This is a safety requirement as far as the chemical structure of the completely discharged element changes and the recharging may be harmful. The best results may be achieved if you store half-charged battery.

Replacement and Utilization of Li-ion Battery

In some years of operation the replacement of Li-ion battery may be required. The replacement is carried out in the specialized service centers of Neurosoft Company. The used Li-ion battery must be utilized according to the accepted norms. The battery contains the poisonous hydride of heavy metals and should be utilized in special places.

5.4. Entering of Personal Data of New Patient, Selection of Patient from Database, Removal of Patient Data

Neuro-Audio-Screen and Neuro-Audion-Screen/OAE screening systems allow to

enter the data of new patients to the memory (maximum 100), save the personal data and patient’s exam results, remove the personal data and the results of patients’ exams.

The device memory is limited that is why it is necessary to remove the unnecessary personal data and results of patients’ exams to free the space for the new exam data.

The data in the device are saved even at the power supply blackout.

To start the exam of a new patient (a new patient is considered the one whose personal data are not saved in the device memory), it is necessary to enter her/his data to the device. To do this, select the item “Patient” of the main menu (Fig. 8) using the arrow buttons and press the “New” button. After that, the new window (Fig. 9) with the listed patient’s data entered in the device memory will appear. It is necessary to point out that it is not required to enter all the patient’s data (name, sex, date of birth, comments) to the device. You can leave all the edit lines empty, than a patient’s identification will be performed by the automatically generated patient’s number.

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If you want to edit a patient’s data saved already in the device memory, choose the “Patient” item of the main menu and press the “Select” button. The same window as for a new patient will be opened.

Fig. 9. The window of a new patent data entering.

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To enter the name, choose the “Name” menu item using the arrow buttons and press “Change” button. The new window with the display keyboard (Fig. 10) will appear on the screen. To select the required letter, shift over the keyboard using the arrow buttons, to enter this letter, press the “Select” button. If you want to remove the letter typed incorrectly, press the “Backspace” button. After the finishing of a surname entering, press “Close” button.

Fig. 10. Display keyboard.

After that, using the arrow buttons choose the “Sex” menu item and press the “Change” button several times till the required sex of a patient indicated right to “Sex” menu item appears on the screen.

The next step is the entering of a patient’s date of birth. To do it, choose the “Date of birth” menu item using the arrow buttons and press the “Change” button. After the termination of a date entering (for example, “30.12.05”), press the “Close” button.

If there are any special data concerning a patient, you would like to save (name of a doctor performing a exam, possible causes of a disease, etc.), than choose the “Comment” menu item using the arrow buttons, press “Change” button, type the required symbols, after that press “Close” button.

After the termination of patient’s data entering, press the “Save” button to save the information in a device memory. To move to the main menu, press the “Close” button.

At the performing of the next exams of the given patient, you can download her/his data from the device memory. To select a patient from the list of the already saved records, it is necessary to choose “Patient” item in the main menu using the arrow buttons. You can review the list of all the patients saved in the screening system memory by shifting “right” and “left” arrow buttons. At that, the identification in the list (“ID” line on the screen) will be displayed over the surname of each patient. As soon as you find the required patient, press the “Close” button, at that you will move to the main window.

To switch quickly to a patient, you can use the search function by a patient name. To do this, choose “Patient” item of the main menu using the arrow buttons and press “Search” button. In the appeared window enter the first letters of a patient’s surname using the virtual keyboard and press “Search” button. The device will display the list of patients whose names start with the entered buttons or the message that a patient is not found. If several patients are detected, select the required one using “up” and “down” arrow buttons. As soon as the required patient is chosen, press “Close” button. The main menu with the selected found patient will display on the screen.

If you want to change the data of a patient already saved in the list (for example, a patient’s date of birth is not indicated and you would like to enter it), select the “Patient” item in the main menu using the arrow buttons and press “Select“ button. In the opened window choose the menu item you would like to change (for example, “Date of birth”) using “up” and “down” button keys, and press the “Change” button. After finishing of the data entering, press the “Save” button and then press the “Close” button to return to the main window.

To remove all the patient’s data (both personal – name, date of birth, sex, comments and exam data) choose the patient from the list (see above) and press the “Delete” button in the main window. At that, the dialog box with the request concerning the removal of the entire patient’s data will appear on the screen. To confirm the removal, press “Yes” button, to cancel the removal, press “No” button.

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In the result of this operation fulfillment (if you press “Yes” button) the ENTIRE patient’s data such as name, surname, sex, date of birth, results of ALL tests by ALL the techniques will be deleted. If you want to delete the results of ONLY ONE test and save the results of other tests and patient’s personal data, read carefully the section 5.10.2 “Removal of Test Results”.

5.5. Patient Preparation for OAE Test

To start operation on Neuro-Audio-Screen and Neuro-Audio-Screen/OAE screening systems you should study and master OAE technique. It is especially important for the testing of newborns and babies. The experience of application of the existing systems for OAE registration shows that it takes about 3 month to get the required skills for the performing of the newborns hearing screening. At the performing of exams of newborns and infants with the use of Neuro-Audio-Screen and Neuro- Audio-Screen/OAE screening systems it is necessary to take into consideration the following.

The newborn should stay quiet and calm, it is usually preferred for the infant to be asleep. To calm a baby down, you can use a baby's dummy, however, the sucking causes the additional noise and decreases the probability of test passing.

The important stage of otoacoustic emission study is the correct placement of a probe to the external ear canal of a patient.

The OAE probe installed well should correspond to the following requirements:

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1. It obturates the external ear canal to convert the small fluctuations of the

tympanic membrane to the pressure fluctuations which can be detected with use of the probe microphone.

2. It prevents from record contamination with the external noise.

3. It provides the required acoustic environment for the generation of the correct

stimuli by the probe telephone.

To satisfy the above-mentioned requirements, the OAE probe should be inserted together with the smooth replaceable ear tips. The ear tip size is selected after the visual assessment of a patient’s external ear canal size. The delivery set of Neuro-Audio-Screen and Neuro-Audio-Screen/OAE screening system includes cone-shaped and mushroom-shaped ear tips. These tips are disposable and should be thrown away after the use.

The cone-shaped ear tips are inserted deeper down into the ear canal than the mushroom-shaped ones. Deeper insertion into the ear canal allows for the measurement of larger emissions due to the reduced ear canal volume. However the deep insertion of a probe can wake a newborn up and make her/him nervous.

In this case it is more preferable to use mushroom-shapes ear tips. At the application of the mushroom-shapes ear tip, pay attention to the ear tip insertion. It should be inserted into the ear canal, not be located near the ear canal entrance with the ear canal opened.

Warming the ear tips prior to insertion helps to keep the baby calm.

If the ear tip is too small, it can let the noise in the external ear canal or distort the stimulus. If the ear tip is too big, it can not be inserted to the external ear canal deep enough. It can lead to the decrease of the signal amplitude and the probe instability during the exam. Besides, if the ear tip is big, it is impossible to exclude the considerable noise interference.

Ear tip should be placed on OAE probe completely. If the ear tip ends in horn widening of a hole, it should be placed on a probe completely so that the horn beginning should be located on the same level with acoustic lines holes. If the ear tip does not end in the horn widening, it should be placed on a probe so that it cut should be located on the same level with acoustic lines holes (Fig. 11). The ear tips sticking out the acoustic lines can cause the additional fluctuation of stimulus signal.

Fig. 11. Ear tip placement on the probe.

The removal of the ear tip is performed in the following way. Holding the nozzle latches of OAE probe, slide the ear tip off according to Fig. 12.

Fig. 12. Correct removal of ear tip.

To avoid the break of drive latches, hold the OAE probe for the latches, other fingers positions during the ear tip removal are not recommended!

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Fig. 13. Incorrect removal of ear tip.

When the probe is inserted into an ear, its end should not be set against the wall of the external ear canal, because it prevents from the stimulus emerge and/or OAE registration. Such situation can be easily detected by watching the curve shape on the stimulus panel.

To register TEOAE in newborns, it is necessary to calm a baby down and make her/him keep quiet and calm. The external ear canal of the newborns can close during the OAE probe insertion. To prevent it, draw of the lobe of the auricle back and down very carefully to level the ear canal. Examine the external ear canal to make sure that it is opened and insert the OAE probe closely. At the moment of the OAE probe insertion it is recommended to turn the OAE probe so to direct the probe cord to the forehead. After the insertion, rotate the OAE probe (without leaving the auricle) so to place the probe cord under 45° to the vertex. After that, leave the auricle.

The ears of the newborns are often wet or contain the extraneous masses. If the good stimulation was not obtained at the first insertion of a probe, replace the ear tip with

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these extraneous masses by the new one and try again. The correctness of the OAE probe insertion at TEOAE exam can be checked indirectly by the stimulus shape.

The Fig. 14 a) represents the oscillating stimulus shape. It does not match to TEOAE registration. In the ear of adult it can be conditioned by the bad placement of OAE probe or the atypical form of the external ear canal. In the last case the stimulus shape should be accepted, however, try to insert the OAE probe again. The Fig. 14 b) represents the stimulus shape at the correct placement of OAE probe for the adults. As for the newborns, the additional fluctuations of stimulus can always be detected. The Fig. 14 c) shows the admissible level of fluctuations of the newborn.

a) b) c)

Fig. 14. The stimulus shape (1).

The Fig. 15 a) demonstrates the effect of the excessive approach of the OAE probe to the wall of the external ear canal or other barrier. The slow round low-frequency wave following the initial sharp peaks is characteristic for this condition. In this case the OAE probe should be reinstalled. The Fig. 15 b) shows the impact of the excessive noise to the stimulus shape. The cause can be in too free OAE probe installation allowing the penetration of the external noise to the external ear canal or noises emitted by the patient. The typical sounds emitted by the patient include breathing, swallowing or tooth-grinding.

a) b)

Fig. 15. The stimulus shape (2).

5.6. TEOAE Test

After the selection of a patient in the list or entering new data about a patient, choose the TEOAE technique and an ear for the exam performing (right or left) in the main menu using the arrow buttons. It is desirable to perform it before the OAE probe insertion to the ear of a newborn not to disturb her/him again. The OAE probe installation should be performed according to the recommendations given in the section 5.8 “Patient Preparation for OAE Test”.

Press the “Select” button. Just after the test start, the device switches to the OAE probe fitting control mode. The TEOAE test window appears on the display (Fig. 16). It is divided into three parts. The stimulus shape is displayed in the top part of the

window, its spectrum is represented in the left bottom part of the window. The right bottom part of the window contains the information displaying panel. Besides, the top part contains a status line and the bottom one has the active menu line. The information displaying panel contains two linear scales: the one is for the displaying of the acoustic meatus volume (“volume”) and the other one is for the noise level displaying (“noise”). If the noise level or the volume exceeds the admissible bound, the corresponding scale becomes red, if it is does not, it is of the greed color. When the OAE probe is fitted correctly, both scales are in the green area.

If during a short-term check the device detects that the OAE probe is fitted bad, the “Check probe fitting” message will appear above the stimulus shape curve. In this case it is necessary to press the “Close” function key, reinstall the OAE probe and start the test again.

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Fig. 16. TEOAE test window (1).

Note: control passing of the OAE probe fitting does not guarantee its correct setting because the device can not follow the situation when the probe tip is fit against the wall of the ear canal or when the canal is closed, for example, by the impacted cerumen.

If the device considers that the OAE probe is fitted correctly, it will switch to the mode of the stimulus intensity tuning. The information panel will display the “Stimulus calibration” message. The stimulus shape is displayed in the top part of the window; its spectrum is represented in the left bottom part of the window.

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After the stimulus intensity tuning, the device switches to TEOAE registration mode. The window displayed in this mode is given in the Fig. 17.

Fig. 17. TEOAE test window (2).

The top part of the window represents the shape of the averaged response, the left bottom one displays its spectrum. The color gamma depends on the selected ear: the blue one is for the left ear, the red one is for the right ear. The two curves of response (A and B) are displayed. Their coincidence testifies of the OAE presence, their difference shows the level of the residual noise. The response spectrum has two areas: the dark one represents the noise level, the light one represents the response level in those areas where it exceeds the noise level. The message “Acquisition” appears on the information panel.

Besides, the following information is displayed here:

 The number of the averaged responses/number of artifacts is located against the

“Stim./Art.” label. The big number of artifacts indicates either the strong external acoustic noise or bad probe fitting. When the number of artifacts exceeds the specified number of averaging (1000 by default), the message “Too much noise” appears on the screen. In this case the test should be repeated in calmer conditions or after the reinstallation of a probe.

 Stimulus stability is against the “Stability” label. The ideal variant is when it is

equal to ”1”. The stability lesser than 0.9 indicates that the probe changed considerably its position during the registration process. If OAE was not detected at that, i.e. the “REFER” signature appeared on the information panel after the test termination, repeat the test after the probe resetting; at that follow the probe position. It should be stable.

 The level of the averaged response, in dB SPL is opposite the “A&B” label. It is

the reference information about the total OAE amplitude in case the A&B value

exceeds the total level of А-В noise. If the reproducibility criteria (“Reproducibility, %”) is set in TEOAE settings, the reproducibility coefficient will be displayed instead of the given criteria in percents. The reproducibility coefficient reveals the correlation between odd and even curves of a signal.

 Total residual noise level, in dB SPL is opposite the “A-B” label. The residual

noise level decreases in the process of the averaging. If OAE is not detected, i.e. the “REFER” signature appears on the information panel after the test termination, and the residual noise level exceeds 10 dB, it indicates highly enough level of the external acoustic noises and means that the test should be repeated in calmer conditions or after the probe resetting.

 The bottom part of the information panel contains the table of OAE presence by

frequencies. The top line marked by “F” letter contains 1, 2, 3, 4 and 5 kHz frequencies. The middle line marked as “SNR” displays the current signal-tonoise ratio on the given frequency (in dB) detected with the use of the digital bandpass filter. The OAE presence on the given frequency is marked by

““ ”symbol. The criterion of its presence is the signal/noise ratio exceeding 4 dB. The general criterion of test passing is the OAE emergence on three of five frequencies. In this case the test is over and the “PASS” signature appears on the information panel. If during the specified number of averaging (1000 by default), OAE is not detected, the test is stopped and the “REFER” signature appears on the information panel.

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After the test termination, you can print the result on the wireless thermal printer by pressing “Print” button. Before printing make sure that the printer is switched on and is in the operating zone (up to 10 meters in the direct visibility conditions).

The exam can be closed by pressing “Close” button. At that the message box “Save exam?” will appear on the screen. Press “Yes” button if you want to save the test results or “No” button if you don’t. After that, you will return to the main menu.

Note: the “Close” button can be pressed at any moment of test performing. If the test is not over, you will return to the main menu, at that, the test results are not saved.

5.7. DPOAE Test

After the selection of a patient in the list or entering new data about a patient, choose the DPOAE technique and an ear for the exam performing (right or left) in the main menu using the arrow buttons. If a patient is a newborn, it is desirable to perform it before the OAE probe insertion to the ear of a baby not to disturb her/him again. The OAE probe installation should be performed according to the recommendations given in the section 5.5 “Patient Preparation for OAE Test”.

Press “Select” button. Just after the test start, the device switches to the OAE probe fitting control mode. The DPOAE test window appears on the display (Fig. 18). It is divided into three parts. The stimulus shape is displayed in the left part of the window, the information panel is in the right one and the stimulus spectrum displaying window

Hearing Screening Systems (Technical Manual)

is just under the information panel. Besides, the top part contains a status line and the bottom one has the active menu line.

The information panel contains two linear scales: the one is for the displaying of the acoustic meatus volume (“volume”) and the other one is for the noise level displaying (“noise”). If the noise level or the volume exceeds the admissible bound, the corresponding scale becomes red, if it is does not, it is of the green color. When the OAE probe is fitted correctly, both scales are in the green area. If during a short-term check the device detects that the OAE probe is fitted bad, the “Check probe fitting” message will appear above the stimulus shape curve. In this case it is necessary to press the “Close” function key, reinstall the OAE probe and start the test again.

Fig. 18. Seal control mode. DPOAE test.

If the device considers that the OAE probe is fitted correctly, it will switch to the mode of the telephones bandpass flatness calibration. In the left part of the window the bandpass flatness of the one telephone and then the other one will appear. After that the device will switch to the stimulus intensity tuning.

After the stimulus intensity tuning, the device switches to DPOAE registration mode. The screen view in this mode is given in the Fig. 19. The DP (distortion product) diagram window will appear in the left part of the screen. The levels of the received OAE on each frequency will display as filled circles of the red color for the right ear and of the blue color for the left one. The grey filled triangles show the noise level. The list of the frequencies will appear on the information panel. During the testing the “PASS”

( ) or “REFER” ( ) symbol will appear opposite each frequency. If the considerable noise or nonstable OAE probe position prevents from the results achieving, the symbol “?” will appear. Besides the information panel contains the “N” linear scale to

display the noise level and the “St.” indicator of the OAE probe fitting stability in the

form of a circle ( ) which becomes green at the normal stability and does red if it is bad. By the analogy with the seal control mode, the noise scale should be in the green area and the stability indicator should be green. If the noise scale or the stability indicator becomes red, the current data are considered to be artifact and do not participate in the OAE selection.

During the registration process the circle and the triangle representing the OAE and noise levels correspondingly on the current frequency appear in the DP diagram window. They start moving up and down showing the process of OAE selection till the specified ratio signal/noise is achieved or the specified time of one point registration expires. After that the “PASS” or “REFER” signature appears on the information panel opposite the corresponding frequency, and the device continues the testing on the next frequency. As soon as all the frequencies are tested, the screening system decides whether the test is passed or not. The corresponding signature will appear in the top part of the screen.

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Fig. 19. The screen view in the DPOAE registration mode.

Note: the “Close” button can be pressed at any moment of test performing. If the test is not over, you will return to the main menu, at that, the test results are not saved.

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5.8. Patient Preparation for ABR Test

To start operation on Neuro-Audio-Screen screening system one should study and master ABR technique. It is especially important for the testing of newborns and babies.

The quality of ABR test performing depends on many factors. Apart the device functioning, the main factors to get the reliable and correct test results are the preparation quality and patient’s condition. It is better to test a patient when she/he sleeps. The newborn is recommended to be tested in between the feedings, when a baby unlikely wants to suck or perform other artifacts connected with the muscle activity. It is better to place the electrodes in a way described in this section below before a newborn falls asleep. Though the testing by ABR technique is not so much sensitive to the acoustic noise in comparison with OAE, however, it is desirable to make no noise during the test performing. It is strongly recommended to perform the testing at the disconnected external power supply of the device and away from the electromagnetic noise sources such as the electric wiring and the electrical appliances.

The places for the electrodes setting should be degreased and treated by the electrode abrasive paste for skin preparation to decrease the skin impedance. The paste remnants can be washed by the alcohol, and the skin should be dried. In case the reusable cup electrodes are used, the cups should be filled with adhesive paste before the placement. The electrodes can be fastened by the adhesive plaster to provide the better fixation.

The electrodes should be placed in a following way: the red one (noninverting) is on the forehead, the black one (inverting) is on the mastoid near the ipsilateral ear (where the stimulus is delivered), green one (ground) is on the mastoid near the contralateral ear. It is admissible to place the ear electrodes not only on the mastoid but other places such as earlobe or ear canal. The example for the left ear is given of the Fig. 20.

Fig. 20. The schematic of the electrodes placement at ABR registration (electrodes arrangement for the left ear testing).

The alternative scheme of the electrodes placement is possible: the red one (noninverting) is on the forehead, the black one (inverting) is in the middle of nucha, the green one (ground) is on the cheek (Fig. 21).

Fig. 21. The Alternative schematic of the electrodes placement at ABR registration.

At the beginning of testing the electrode impedance is checked automatically, and in case it exceeds 5 kΩ, the testing is not started. If the satisfactory impedance is not achieved, the repeated preparation of a patient’s skin and resetting of the electrodes may be required.

Functioning

The OAE probe (by default), the headphones or the insert earphones may be used as an auditory stimulator. The OAE probe application is analogous to the one described in section 5.5 “Patient Preparation for OAE Test”. When using the insert earphones, please, make sure that the front tubes are clean and the sound passes through them. Put the foam ear tips on the front tube adapters, press it out with your fingers to fit the ear canal, insert it into the ear and wait till it straighten to obturate the ear canal.

5.9. ABR Test

After the selection of a patient in the list or entering new data about a patient, choose the ABR technique and an ear for the exam performing (right or left) in the main menu using the arrow buttons. It is desirable to perform it before the OAE probe insertion to the ear of a newborn not to disturb her/him again. The OAE probe installation should be performed according to the recommendations given in the section 5.5 “Patient Preparation for ABR Test”.

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Press the “Select” button. Just after the test start, the screening system switches to the impedance measurement mode (Fig. 22).

Fig. 22. The impedance measurement window.

The current values of impedance for the electrodes “+”, “-” and “Ground – ” (kΩ) are displayed on the screen. To the left from them the circles colored from red up to green are drawn. If all the three circles are colored green, it means that the impedance values for all the electrodes are within the norm, and the next stage will be automatically started in several seconds. At that, the ABR test window presented in the Fig. 23 will appear on the screen. If the automatic transition does not occur, and the impedance values, according to your point of view, are satisfactory for the test performing, press “Start” button to start the testing manually.

Fig. 23. ABR test window.

The window is separated into two parts. The top part represents the response shape

received during the registration process on the grid background. The bottom part contains the information panel. Besides, the status line is provided in the top part of the window, and the signature line for the buttons is located in the bottom part.

The next stage depends on the applied stimulator. If the headphones are used, the screening system switches to the ABR registration mode, in case the OAE probe is applied, it passes to the OAE probe fitting control mode. At that, the “Probe fitting” signature will be displayed on the information panel in the bottom part of the screen. If during a short-term check the screening system detects that the OAE probe is placed bad, the signature “Check probe fitting” will appear on the information panel. In this case it is necessary to press the “Close” button, reinstall the probe and perform the test once again.

Note: control passing of the OAE probe fitting does not guarantee its correct setting because the device can not follow the situation when the probe tip is set against the wall of the ear canal or when the canal is closed, for example, by the impacted cerumen.

If the screening system considers that the OAE probe is placed correctly, it will switch to the stimulus volume selection mode. The “Stimulus calibration” signature will appear on the screen. The stimulus shape will display in the top part of the window.

Functioning

After the stimulus intensity tuning, the screening system switches to the ABR registration mode, at that the signature “Registration” will be displayed in the bottom part on the screen. The shape of the averaged response will be displayed in the top of the window. The color gamma depends on the selected ear: the blue color is for the left ear and the red one is for the right one. The displaying scale can be changed in the limited range using the “up” (zoom in) and “down” (zoom out) buttons of the arrow buttons. At that, the value of the scales, which current value is always represented in the top left corner of the screen, is changed. The so called “scale 1-2-5” is used for that. The visible size of the grid unit segment (in pixels) remains constant.

At the very ABR curve onset, the stimulus artifact area is located. Its duration is specified in the settings, and it is not considered at the signal parameters calculation. At the displaying, this area is represented by the straight line in the response curve onset.

The mode of the curves displaying can be changed cyclically by the “View” button pressing. There are three modes of the displaying: sum averaged curve, even and odd averaged curves (A and B buffers), native curve. By default the mode of the even and odd averaged curves displaying is activated (as in the Fig. 25). The two response curves (A and B) are displayed; their coincidence testifies the ABR presence, and their difference shows the residual noise level.

Two scales are located leftward on the information panel. The top scale “ABR” indicates the integral criterion of ABR presence calculated on the basis of Fsp, signal-tonoise ratio and residual noise level parameters. In the recording process the scale color is red until the ABR presence criteria is achieved. As soon as this criterion is achieved, the scale becomes green, the averaging is stopped and the signature “PASS” appears on the information panel top. The bottom scale “EEG” indicates the current level of EEG and noises. The lower is the level, the quicker is averaging. If the

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level is normal, the scale color is green. If it exceeds the specified rejection threshold, the scale becomes red and the current epoch is rejected. Rightward the information panel the following information is displayed:

 “Stim./Art.” – the number of the averaged responses and the number of the rejected

responses.

 “Fsp” – the statistical parameter of the signal by which the ABR presence is

defined. It is considered that ABR is present, if Fsp value is more than 3,1.

 SNR” – the signal-to-noise ratio. This ratio should be 1.5-2 and higher for the device

to detect ABR presence.

 “RNL” (“residual noise level”) – the active value of the difference between the A and

B averaged curves. The optimum value is 110 nV and lesser.

The big number of artifacts evidences either the strong external acoustic noise or the bad probe setting. In this case the test should be repeated in calmer conditions and after the probe resetting. The more is Fsp value, the better is the signal “reproducibility”. The level of the residual noise decreases in the process of the averaging. If ABR is not detected, i.e. the signature “REFER” appears on the information panel after the test termination, and the residual noise level exceeds 110 nV, it may indicate highly enough level of the external acoustic noises and means that the test should be repeated in calmer atmosphere or after the probe resetting

When the values of all the calculated parameters exceed the liminal ones, the registration is stopped and the signature indicating the test result “PASS” appears on the information panel. The maximum number of averaging is specified in ABR test settings (see section 6.4 “ABR Settings”). If during the specified number of averaging (8000 by default) ABR is not detected, the test is stopped and the “REFER” signature appears on the information panel.

After the test termination, you can print the result on the wireless thermal printer by pressing “Print” button. Before printing, make sure that the printer is switched on and is in the operating zone (up to 10 meters in the direct visibility conditions).

The exam can be closed by pressing “Close” button. At that, the message box “Save exam?” will appear on the screen. Press “Yes” button if you want to save the test results or “No” button if you don’t. After that, you will return to the main menu.

Note: the “Close” button can be pressed at any moment of test performing. If the test is not over, you will return to the main menu, at that, the test results are not saved.

5.10. Review, Printing and Removal of Results

The test results are the test data by one of the available techniques performed once. That means if you performed five tests by one of the techniques, you will get five results. It is important for the principle understanding of the results saving, printing and removal. For example, the removal of one test result will not lead to the removal of all the performed tests results.

The test results are saved in the device memory separately for each patient. The number of the tests saved in the device memory is not less than 200. The saving of several results by several techniques is possible for one patient.

5.10.1. Review and Printing of Test Results

To review, it is necessary to select a patient from the list, than in the main window choose the required technique and side using the “up” and “down” arrow buttons.

To the right of the test techniques, the list of the saved exams is represented (Fig. 24).

If the check box is checked, it means that the test is passed (the result is positive), in case the check box is unchecked, the test is failed. The first figure indicates the sequence (order) number of the current selected exam, the second one (located after the symbol “/”) indicates the total number of the saved tests by the present technique for the given patient. Further the date of the exam performing in “month-day-year” format is presented.

Functioning

Fig. 24. The exam selection for the review/printing.

The selection of the exam from the list is performed by the “left” and “right” arrow buttons, at that the date of the test and its order (or sequence) number (the first number in the displayed line) will be changed.

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After selection of the required exam, press the “View” button. The exam result and all the required data (Fig. 25, Fig. 26, Fig. 27) will appear on the screen. If you want to print the test result on the printer, press “Print” button. To terminate the review, press “Close” button.

At the review of the ABR test, you can change the vertical scale using the “up” and “down” arrow buttons. The “View” button serves for the switching between the modes of the curves displaying on the screen. There are two modes of the displaying: sum averaged curve (Fig. 26) and even and odd averaged curves (A and B buffers) (Fig. 25). By default the mode of the even and odd averaged curves displaying is activated. The two response curves (A and B) are displayed; their coincidence testifies the ABR presence, and their difference shows the residual noise level.

Fig. 25. The review of ABR test results (1).

Fig. 26. The review of ABR test results (2).

Fig. 27. The review of TEOAE test results.

Functioning

Fig. 28. The review of DPOAE test results.

At the “Print” button pressing, the Bluetooth wireless connection is activated automatically. After the printing termination, the connection deactivates that is why there is no need to change Bluetooth settings in the “Settings” menu.

If you want to review/print the results of other test, choose this test and press the “View” button.

The printing of the results is also possible from the main menu. To do this, select a patient in the main menu, choose the exam and press “Print” button.

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There are two types of the reports: complete and brief (see the report descriptions in the sections “TEOAE Report Description”, “DPOAE Report Description”, “ABR Report Description”). The report type for printing can be selected in the printer settings. The brief report type allows to use the printer paper more efficiently.

The modern thermal printers use thermal paper for the printing. Do not expose the printed results to sunlight or heat. Printing on thermal paper fades with exposure to light or heat. Keep the printing in the cool place protected from the direct sunlight.

5.10.2. Removal of Test Results

This paragraph describes the way of removal of ONE patient’s test results. To delete ALL the results of ALL tests and patient’s personal data, see the section

5.4. “Entering of Personal Data of New Patient, Selection of Patient from Database, Removal of Patient Data”.

To remove the test results, choose the patient from the list, then select the technique and an ear using “up” and “down” arrow buttons in the main menu, after that select the required exam which you would like to delete using “right” and “left” buttons and press the “Delete” button. At that, the dialog box with the request concerning the removal of test results will appear on the screen. To confirm the removal, press “Yes” button, to cancel the removal, press “No” button.

5.10.3. TEOAE Report Description

The complete report is represented in the Fig. 29.

Functioning

Fig. 29. The view of the TEOAE complete report.

The report consists of the following components:

1. Name of a patient if it was entered.

2. Date of birth if it was entered.

3. Date of the test performing based on the settings of the internal clock. If the clock is set correctly, the date in the report will also be correct.

4. Ear (right/left).

5. Test result (pass/refer).

6. Stimulus intensity during the exam in dB SPL.

7. OAE probe stability during the exam.

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8. Amplitude of the received total response (in dB), or reproducibility coefficient, %.

9. Amplitude of the received total noise (in dB).

10. Analysis table column by frequencies in which the frequency (in kHz) is given.

11. Analysis table column by frequencies in which the signal-to-noise ratio (in dB SRL) on the given frequency is given.

12. Analysis table column by frequencies in which the OAE presence/absence on the given frequency is shown. The * symbol means the OAE presence and its absence denotes the OAE missing.

13. Stimulus shape.

14. Stimulus spectrum.

15. Response shape.

16. The response (transparent) and noise (vertically hatched) spectrum.

The brief report form differs in the absence of the 7-9 and 13-16 elements.

5.10.4. DPOAE Report Description

The complete report is represented in the Fig. 30.

Fig. 30. The view of the DPOAE complete report.

The report consists of the following components:

1. Name of a patient if it was entered.

2. Date of birth if it was entered.

3. Date of the test performing based on the settings of the internal clock. If the clock is set correctly, the date in the report will also be correct.

4. Ear (right/left).

5. Test result (pass/refer).

6. Column with f2 frequencies (in kHz).

7. Column with tone levels on f1/f2 frequencies (in kHz).

8. Column with the results by frequencies. If the emission on the given frequency

is presented, it is indicated by the symbol, if not – by symbol. If the considerable noise or nonstable OAE probe position prevents from the results achieving, the symbol “?” will appear.

Functioning

9. Column with signal-to-noise ratios (in dB SPL).

10. Distortion product diagram (DP-gram). The line with circles indicate the emission on the distortion product frequency and the line with the triangles denote the noise.

The brief report form differs in the absence of distortion product diagram.

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5.10.5. ABR Report Description

The complete report is represented in the Fig. 31.

Fig. 31. The view of the ABR complete report.

The report consists of the following components:

1. Name of a patient if it was entered.

2. Date of birth if it was entered.

3. Date of the test performing based on the settings of the internal clocks. If the clock is set correctly, the date in the report will also be correct.

4. Ear (right/left).

5. Test result (pass/refer).

6. Stimulus volume during the exam in dB nHL.

7. Frequency of the stimulus delivery.

8. Criterion of the Fsp test passing.

9. Criterion of the test passing – signal-to-noise ratio (in dB SPL).

10. Criterion of the test passing – floor noise, active value in nV.

11. Scale value.

12. Response shape, odd/even curves.

The brief report form differs in the absence of the 9-12 elements.

6. Settings

The Neuro-Audio-Screen and Neuro-Audio-Screen/OAE screening systems pro- vide the possibility to change different settings. Pay attention, that OAE and ABR settings are specified by default, that is why there is no need to change these parameters without reason. If you changed the OAE and/or ABR registration parameters and want to return to the standard parameters of all the techniques, press “Standard” button in the “Settings” menu of OAE and ABR techniques. To do this, select the “TEOAE settings”, “DPOAE settings” or “ABR settings” item in the settings menu using “down” arrow button and press the “Select” button. After that, press “Standard” button. At that, the dialog box for the conforming of the standard settings application for OAE and ABR tests will appear on the screen. To set the default settings, press “Yes” button, to exit this window saving the previous settings, press “No” button. In case you press “Yes” button, the OAE and ABR settings will switch to default ones specified below. If you want to specify the standard settings only for one test, see the section 6.2 “TEOAE Settings”, 6.3 “DPOAE Settings” or 6.4 “ABR Settings”.

Settings

The default settings for TEOAE test:

 Template – “Noisy”

 Noise level, dB SPL –60.

 Intensity, dB SPL – 80.

 Stimuli number – 1000.

 SNR pass criteria, dB – 4.

 Reproducibility, % – -.

 Frequencies for pass – 3.

 Stim. rate, Hz – 66.

 Number of frequencies – 5 (1.0..5.0)

The standard settings for DPOAE test:

 Template – “Noisy (screening)”.

 Mode – 4.

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 Volume level 1, dB SPL – 65.

 Volume level 2, dB SPL – 55.

 Noise level, dB SPL – 25.

 SNR pass criteria, dB – 8.

 Frequencies for pass, % – 50.

 Point time, s – 5.

The standard settings for ABR test:

 Template – “Screening 60 dB”.

 Intensity, dB nHL – 60.

 Stim. rate, Hz – 92.

 Rejection threshold, µV – 90.

 Artifact duration, ms – 1.

 Stimulator – OAE probe.

 Stimuli number – 8000;

 Notch filter – 50 Hz.

To change the settings, it is necessary to select “Settings” item in the main menu by pressing the “down” arrow button and press “Select” button. The “Settings” window appearance is shown in the Fig. 32.

Settings

Fig. 32. The “Settings” menu window.

6.1. General Settings

The general settings include the following:

 Report type. See the report description in the sections 5.10.3 “TEOAE Report De-

scription”, 5.10.4 “DPOAE Report Description” and 5.10.5. “ABR Report Description”.

 Bluetooth.

 Version – the menu item for internal software version check.

To change the report type (complete or brief), enter the “Settings” menu, choose “Report type” item using the “up” and “down” buttons and then press “Change” button to select the required type of the report. To exit this menu, press “Close” button.

The Bluetooth setting activates/deactivates this type of the wireless connection used for the data transfer to the personal computer (see the detailed information in software manual supplied with the device). To change the Bluetooth settings, enter the “Settings” menu, choose the “Bluetooth” item using “up” and “down” buttons and activate/deactivate this option by pressing the “Change” button. Wait for several seconds till the state of this type of connection changes on the screen (the signature in “Bluetooth” menu item will change and the pictogram in the top part of the screen will highlight/disappear). To exit the menu, press “Close” button. This function should be used only for the device connection with the computer for the data exchange. Bluetooth on/off at printing occurs automatically (by “Print” button pressing).

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If the Bluetooth connection is activated, the operation time of the screening system supplied from the built-in rechargeable battery lessens, that is why disable this function if it is not required at the present moment.

6.2. TEOAE Settings

TEOAE settings include the following:

 Noise level, dB SPL. Range – from 20 up to 70.

 Intensity, dB SPL. Range – from 60 up to 80.

 Stimuli number. Range – from 100 up to 1000.

 SNR pass criteria, dB. Range – from 3 up to 10.

 Reproducibility, %. Dash (is not set), 50%, 60%, 70%, 80%, 90%.

 Frequencies for pass, 2 + 1 – two frequencies from 1 up to 4 kHz and one

frequency 5 kHz, 3 – any three frequencies, 4 – any four frequencies, 5 – any five frequencies.

 Stim. rate, Hz. Range – from 49 up to 66.

 Number of frequencies – 5 (1.0..5.0) – 5 frequencies within the range from 1 to 5

kHz; 6 (0.7..4.0) – 6 frequencies within the range from 0.7 to 4 kHz; 6 (1.5..4.0) – 6 frequencies within the range from 1.5 to 4 kHz.

These settings are stored in the templates. The screening system provides three default templates – the set of specified parameters: “Noisy”, “Normal”, “Quiet”. To select the template, enter the “Settings” menu and then using “up” and “down” arrow buttons, select “TEOAE settings” menu item and press “Change” button. After that the window represented in the Fig. 33 will appear. Switch the template using “right” and “left” arrow buttons.

Please pay attention that the default templates can not be changed and/or removed. To add the template, press “New” button, enter the name of a new template and set it up. If you want to remove the template, press “Delete” button.

Settings

Fig. 33. TEOAE test parameters setting.

To change the settings in your template, select the required setting using “up” and “down” arrow buttons and change the value by 1 unit by pressing the “left” (-1) and “right” (+1) arrow buttons or by 10 units by pressing “-10” and “+10” buttons.

If you want to set the standard settings, press the “Standard” button. The dialog box with the request concerning the default settings setup will appear on the screen. Press “Yes” button to set them or “No” button to cancel. If you press “Yes” button, the standard settings will be set only for TEOAE test.

After finishing the settings change, press “Close” button, at that the dialog box with the request concerning the confirmation to save the changes made in TEOAE settings will appear. To save the changes, press “Yes” button, to exit without saving of the changes, press “No” button.

6.3. DPOAE Settings

DPOAE settings include the following:

 Mode (4, 8, 12).

 Volume level 1, dB SPL. Change range – from 50 up to 70.

 Volume level 2, dB SPL. Change range – from 50 up to 70.

 Noise level, dB SPL. Change range – from 20 up to 70.

 SNR pass criteria, dB. Change range – from 6 up to 10.

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 Frequencies for pass, %. Change range – from 50% up to 100%.

 Point time, s. Change range – from 0,5 s up to 5 s.

These settings are stored in the templates. The screening system provides three default templates – the set of specified parameters: “Noisy (screening)”, “Normal (screening)”, “Quiet (standard)”. To select the template, enter the “Settings” menu, select “DPOAE settings” menu using “up” and “down” arrow buttons and press “Change” button. After that the window represented in the Fig. 34 will appear. Switch the template using “right” and “left” arrow buttons.

Fig. 34. DPOAE test parameters setting.

To change the settings in your template, select the required setting using “up” and “down” arrow buttons and change the value by 1 unit by pressing the arrow buttons “left” (-1) and “right” (+1) or by 10 units by pressing “-10” and “+10” buttons. The “-10” and “+10” buttons are not used for the “Mode” setting.

The “Mode” setting allows choosing the number of frequencies for testing. In the “Screening” mode there are 4 of them – from 1,4 up to 5,7 Hz, in the “Standard” mode there are 8 of them – from 1,4 up to 8 kHz, the “Extended” mode provides 12 frequencies – from 0,55 up to 8 kHz.

The “Volume level 1, dB SPL” and “Volume level 2, dB SPL” settings allow specifying the intensity of the testing tone on f1 and f2 frequencies correspondingly.

The “Noise level, dB SPL” setting specifies the threshold of the artifacts rejection by noise level.

The “SNR pass criteria, dB” setting specifies the criteria for test passing by signal-to-noise ratio on the required frequency.

The “Frequencies count for pass, %” specifies the minimal percent of the frequencies for test performing to obtain the “PASS” total test result. This setting is used together with the “SNR pass criteria, dB” criterion to specify the general criterion for test passing. For example, if the “SNR pass criteria, dB” is set on 4 dB and the “Frequencies for pass, %” is done on 50%, than the test should contain at least 50% of frequencies on which the emission is at the minimum 4 dB higher the noise level to achieve the “PASS” result.

The “Point time, s” setting allows to specify the maximum averaging time on each frequency. In case the criterion of passing on the given frequency is achieved earlier than the maximum time expires, the test on this frequency is terminated earlier and the screening system will switch to the testing of the next one.

Settings

After finishing the settings change, press “Close” button, at that the dialog box with the request concerning the confirmation to save the changes made in DPOAE settings will appear. To save the changes, press “Yes” button, to exit without saving of the changes, press “No” button.

6.4. ABR Settings

ABR settings include the following:

 Intensity, dB nHL. Range – from 0 up to 100.

 Stim. rate, Hz. Range – from 1 up to 100.

 Rejection threshold, µV. Range – from 0 (disabled) up to 200.

 Artifact duration, ms. Range – from 0 up to 5.

 Stimulator – either OAE probe or TA-01, TDH-39 headphones or ER-5A, ER3-10

insert earphones.

 Stimuli number. Range – from 1000 up to 8000.

 Notch filter. Off, 50 Hz, 60 Hz. It allows to remove the noise emitted by alternating-

current mains.

These settings are stored in the templates. The screening system provides three default templates – the set of specified parameters: “Screening 60 dB”, “Screening 30 dB”, “Standard 60 dB”. To select the template, enter the “Settings” menu and then using “up” and “down” arrow buttons, select “ABR settings” menu item and press

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“Change” button. After that the window represented in the Fig. 35 will appear. Switch the template using “right” and “left” arrow buttons.

Fig. 35. The window of ABR technique parameters setting.

After finishing the settings change, press “Close” button, at that the dialog box with the request concerning the confirmation to save the changes made in ABR settings will appear. To save the changes, press “Yes” button, to exit without saving of the changes, press “No” button.

6.5. System Settings

System settings include the following:

 Sensitivity, mV/Pa. The change range – from 5 up to 50.

 Printer type – SPRINT or UPS.

 Address – the address of the printer.

 Date.

 Time.

 Brightness – brightness of the screen highlight. Change range – from 1 up to 11.

 Auto turn off, min. Change range is from 1 up to 30 minutes or dash (do not use

automatic device switch off).

 Password – four-digit code can be used for the protection of OAE, ABR and system

settings from unauthorized change.

 Language – allows to switch the language of menu and service information.

To change any of these settings, enter the “Settings” menu, then select the “System settings” item using “up” and “down” arrow buttons and press “Change” button. The window represented in the Fig. 36 will appear on the screen.

Settings

Fig. 36. The window of system parameters setting.

The “Sensitivity” parameter specifies the sensitivity of the OAE probe microphone. Each OAE probe can have the microphone with the sensitivity differing from others. The concrete value is marked on the label fixed on the OAE probe cable. The correct setting of the “Sensitivity” parameter is required for the receiving of the test correct results.

Before starting to work, make sure that the device settings contain the same value as on a label located on OAE probe cable.

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To change the microphone sensitivity, select the “Sensitivity” menu item using “up” and “down” arrow buttons. Change the value by 1 unit by pressing the arrow buttons “left” (-1) and “right” (+1) or by 10 units by pressing “-10” and “+10” buttons.

To change the printer type, select the “Printer type” menu item using “up” and “down” arrow buttons. To change the printer type, press the “Change” button till the required one appears, at that, the printer type will change automatically on the one printer type indicated in the already programmed list of the device.

Each printer has its unique address. To print the exam results on your printer, it is necessary to enter it in the device. Read the printer technical manual to learn the printer address. For example, for SPRINT printers, at the switching on the power supply, it is necessary to press and hold the control button till the page with the printer parameters including the printer address prints out.

To set the printer address, choose the “Address” menu item by pressing “up” and “down” buttons and press the “Change” button. The change window of the printer address is represented in the Fig. 37.

Fig. 37. The change window of the printer address.

The address is 12 hexadecimal figures. It is entered in the same format it is displayed on the screen, i.e. “AA:BB:CC:DD:EE:FF”. The figures in a position are changed by “up” and “down” buttons pressing. You can also change the figure using the screen keyboard. To do this, press “Change” button. The switching between the figure positions is performed by pressing “left” and “right” buttons. After the address entering, press the “Close” button.

To set the date, choose the “Date” menu item using “up” and “down” buttons and press “Change” button. The date setting window is represented in the Fig. 38.

Settings

Fig. 38. The date and time setting window.

In English language the date is entered in the same format it is represented in the menu, i.e. “MM:DD:YYYY” (month/date/year). As for other languages (French, German and Portuguese), the date is “DD:MM:YYYY” (date/month/year). The figures in a position are changed by “up” and “down” buttons pressing. You can also change the figure using the screen keyboard. To do this, press “Change” button. The switching between the figure positions is performed by pressing “left” and “right” buttons. After the date entering, press the “Close” button.

To change the time, choose the “Time” menu item using “up” and “down” buttons and press “Change” button. The time setting window will display on the screen. The time is entered in the same way as date, in the format it is represented in the menu, “HH:MM:SS” (hour/minutes/seconds). The hour value is entered in 0-24 range. After the time entering, press the “Close” button.

To change the display brightness, choose the “Brightness” menu item using “up” and “down” arrow buttons. The “left” arrow button will decrease the display brightness and the “right” one will increase it.

The device provides the possibility of automatic shutdown after the specified period of inactivity. To set up this period, select “Auto turn off, min” item using “up” and “down” arrow buttons. The buttons “left” and “-10” decrease the time by 1 or 10 minutes correspondingly, the “right” and “+10” buttons increase the time by 1 or 10 minutes correspondingly. If you decrease the auto turn off time up to lesser 1 minute, the dash will appear opposite the menu item. It means that the device auto turn off is not used, i.e. the device will operate constantly until it is off using on/off button.

Hearing Screening Systems (Technical Manual)

The device provides the possibility to protect the settings from unauthorized change. To do this, enter the password to access the settings. The four-digit code can be used as a password. In case the password is set, you should enter it in the appeared window to change the settings of OAE, ABR and system settings. If the entered password coincides with the specified one, the settings can be changed, otherwise, your access to the setting will be denied. The password specified earlier can be disabled and the device can be switched to operating mode without password. In this case you will not have to enter the password to change OAE, ABR and system settings. To disable the password specified earlier, select “Password” menu item and press “Change” button. In the appeared window press “Clear” button. You will automatically return to editing window of system settings. In this window press “Close” button and answer “Yes” to the question concerning the necessity of changes saving.

The screening system supports ten interface languages:

 Russian.

 English.

 French.

 German.

 Portuguese.

 Polish.

 Spanish.

 Italian.

 Czech.

 Slovak.

To change the interface language, it is required to open the “Settings” menu, after that select the “System settings” item using “up” and “down” arrow buttons, then the “Language” item by using the “up” and “down” arrow buttons and press “Change“ button to switch the interface. After that, press the “Close” button.

If you accidentally specified the language differing from the required one, and it is difficult for you to orient in the menu items, follow the instructions below:

1. Switch off the screening system.

2. Switch on the screening system. The main menu window will display on the screen.

3. Select the bottommost menu item by navigating “up” and “down” arrow buttons.

4. Press the left-most multifunctional button.

Data Exchange with Computer

5. Select the last but one menu item by pressing “down” arrow button.

6. Press the left-most multifunctional button (if the dialog box offering to enter the figures will appear on the screen, enter the password and press the right-most multifunctional button).

7. Select the last menu item by pressing “down” arrow button.

8. Press the left-most multifunctional button several times till the signature “English” appears in the top part of the screen.

9. Press the right-most multifunctional button.

After finishing the settings change, press “Close” button, at that the dialog box with the request concerning the confirmation to save the changes made in system settings will appear. To save the changes, press “Yes” button, to exit without saving of the changes, press “No” button.

7. Data Exchange with Computer

7.1. Screening System Connection to Computer

To exchange the data with Neuro-Audio-Screen screening system and the computer it is necessary to provide the connection. It is required, for example, for the downloading of the patients’ list or for the receiving of the exam results. To provide the connection, the so called Bluetooth personal area network (PAN) is used, the pass key “12345”. The connection procedure varies depending on the computer and operating system. The typical order of operations (step-by-step) in Windows XP operating system at the use of the standard Bluetooth adapter is described below. If you use other operating system or adapter manufactured by other company, it is necessary to follow the documentation supplied with these devices and software.

Hearing Screening Systems (Technical Manual)

Step 1. Activate Bluetooth on the screening system (see section 6). The screening system should be near the computer. Find the Bluetooth item on the computer task bar, press it with the right mouse button and in the appeared menu choose the “Join a Personal Area Network” item (Fig. 39).

Fig. 39. Device connection with the computer. Step 1.

Step 2. If you already set the connection to the screening system, move to step 7, otherwise the dialog box represented in the Fig. 40 will appear on the screen. Press the “Add” button in this window.

Fig. 40. Device connection with the computer. Step 2.

Data Exchange with Computer

Step 3. In the appeared dialog box check the “My device is set up and ready to be found” checkbox and press “Next” button (Fig. 41).

Fig. 41. Device connection with the computer. Step 3.

Step 4. The computer will perform searching and in some time will show the list of the detected devices. Choose Neuro-Audio-Screen screening system in the list and press the “Next” button (Fig. 42).

Fig. 42. Device connection with the computer. Step 4.

Hearing Screening Systems (Technical Manual)

Step 5. In the appeared dialog box select “Use the passkey found in the documentation” and enter the passkey “12345” (Fig. 43). Press “Next” button.

Fig. 43. Device connection with the computer. Step 5.

Step 6. The computer will exchange the passkeys with the screening system and will inform about that. In the appeared dialog box press “Finish” button (Fig. 44).

Fig. 44. Device connection with the computer. Step 6.

Data Exchange with Computer

Step 7. The dialog box with the list of the devices (Fig. 45) will appear on the screen. Choose Neuro-Audio-Screen screening system and press the “Connect” button. The computer will connect the screening system and you will have a new session.

Fig. 45. Device connection with the computer. Step 7.

7.2. Operation with Neuro-Audio-Screen Manager Software

The Neuro-Audio-Screen and Neuro-Audio-Screen/OAE screening systems are supplied with the Neuro-Audio-Screen Manager software. It can function properly on any IBM compatible computer with Intel Pentium Celeron 1 GHz (Intel Pentium IV is recommended) processor and under control of Windows XP/Vista/7 operating system. For the software setup there should be 1 Gb of free hard disk space and not less than 20 Mb of free hard disk space for the exam archive. In case of operation under control of Windows XP, the installed .NET Framework 2.0 component or higher should be available. The Bluetooth adapter either built-in or external should be connected to the computer.

As soon as you made a connection with the device, you can control the list of patients stored in the device and also transfer the data of the already executed exams to the computer. The Neuro-Audio-Screen Manager software is intended for this purpose (further “the software”).

Connect the computer to Neuro-Audio-Screen screening system as described in p. 7.1.

To start the operation with the program, first install it from the disk included in the screening system delivery set.

Hearing Screening Systems (Technical Manual)

In case the installation disk is missing, you can always download all the necessary components and last version of the program distributive from our site: http://www.neurosoft.ru/eng/soft/. To get an access to the files, enter the name and the password which you can obtain in the commercial department of Neurosoft Ltd.

Insert the disk into the disk driver of your computer. As soon as the menu appears on the screen, choose “Neuro-Audio-Screen Manager” item in it.

If the menu hasn’t appeared, open the disk content using Windows Explorer and start AUTORUN.EXE file.

After the installation, the shortcuts for “Neuro-Audio-Screen Manager” start will appear on the desktop and in the “Start” menu. You can use any of them.

After the program start, the main window will appear on the screen (Fig. 46).

List of exams

List of patients

Report area

Fig. 46. Neuro-Audio-Screen manager main window.

Using the program, you can carry out the transfer of patient list and performed exams from the device to the computer, generate the list of patients for the exam performing, print the results of the performed exams and update the device firmware.

The main window consists of the following parts: the menu, the toolbar, the patients list, the exams list and report area.

The toolbar is intended for quick access to the most frequently used program functions.

The list of patients is represented as the table with the following areas:

Data Exchange with Computer

 “№” – the sequence number.

 “*” – the selection area (is used to generate the reports and for exams import).

 “Patient” – patient name.

 “Sex” – patient sex.

 “Date of birth” – patient date of birth.

 Brief summary of the performed exams. Here the information concerning the

success of the test passing by TEOAE (left and right ears), DPOAE (left and right ears) and ABR (left and right ears) techniques is displayed.

The list of exams is also represented as the table with the following areas:

 “№” – the sequence number.

 “*” – the selection area (is used to generate the reports).

 “Date” – the date of exam performing.

 “Test” – the technique of test performing.

 “Ear” – the ear for which the test was performed.

 “Res” – the test result (“+” – the test is passed, “-” – the test is failed, “?” – the data

is insufficient to make a decision).

Hearing Screening Systems (Technical Manual)

7.2.1. Receiving of Patient List and Exams

To receive the list of patients and exams from the device, it is required to activate Bluetooth on it and make the connection as it was described above. After that it is

possible to receive the list of patients. Press button “Acquire data from the device”. The list of patients will appear on the screen (Fig. 47).

Fig. 47. List of patients.

Data Exchange with Computer

In this list select those patients whose exams you would like to import (or select all of

them to receive all the exams). After the patients selection, press “Import exams” button. The dialog box asking where the information should be saved will appear on the screen (Fig. 48).

Fig. 48. Folder selection.

After the folder selection the information saving will occur and the list of the selected patients and also the list of performed exams will appear on the screen (Fig. 49).

Fig. 49. List of exams.

As soon as you saved the exams to the computer, you can operate with them even if the device is switched off or disconnected.

Hearing Screening Systems (Technical Manual)

7.2.2. Operation with Saved Exams

To open the saved data, press “Open database” button. The dialog box for file selection will appear on the screen (Fig. 50).

Fig. 50. Database opening from the disk.

Select the folder where the information about the patients and exams is kept (pa- cients.xml file should be available there). After the selection of the folder, the information will download to the program and display on the screen (Fig. 51).

Fig. 51. List of patients.

Data Exchange with Computer

7.2.3. Exam Review and Print

To review and/or print the exams, select the required rows in the list of patients and

press “Generate report” button. The exam report for all selected patients will be generated and displayed in the report area (Fig. 52).

Fig. 52. Report of the performed exams.

To print the exam report, press “Print report” button. If some exams should be excluded from the report, uncheck the checkboxes opposite them in the exam list before the report generation.

7.2.4. Operation with Patients List

One of the main tasks of Neuro-Audio-Screen manager software is the control of the patients list. You can work with the patient list at any stage (after data import from the device, after data download from the disk and just after the program opening).

To add a new patient, use “Add patient” button or [Ins] key. The “Patient data” dialog box will appear on the screen (Fig. 53).

Fig. 53. “Patient data” dialog box.

You can switch between the input fields using both [Tab] key and the mouse.

Hearing Screening Systems (Technical Manual)

Enter the required patient data and press “OK” button or use “Cancel” button if you do not want to add the patient to the list. Also you can use keyboard keys: [Enter] key pressing is analogous to “OK” button pressing and [Esc] button is equal to “Cancel” one.

To edit the patient data, press “Edit patient” button. The “Patient data” dialog box will appear on the screen (Fig. 53).

To remove a patient, click the row with her/his name with the mouse (Fig. 54).

Fig. 54. Patient removal from the list.

Press “Delete patient” button or [Del] key. Confirm a patient removal in the appeared dialog box (Fig. 55) by pressing “OK” button or deny the removal using “Cancel” button.

Fig. 55. Request to delete a patient.

The list of patients can be saved to the disk using “Save patients list” button. To do this, in the appeared dialog box (Fig. 48) choose the folder where to save the list of patients and press “OK” button to save it or “Cancel” button to close the window without saving. Afterwards, to return to the patients list, open it from the disk. This procedure is described in section 7.2.2 “Operation with Saved Exams”.

Data Exchange with Computer

At any moment you can create the new patients list. To do this, press “Create new pa-

tients list” button. If the current patients list already contains the records, the warning (Fig. 56) will appear on the screen.

Fig. 56. Request how to act at the new patients list creation.

If you press “Yes” button, the current list will be saved to the disk. If you choose “No”, the current list will not be saved, the new patients list will be created. In case you press “Cancel” button, the current list will remain on the screen, at that the new one will not be created.

After creation of the patients list, it can be transferred to the device. It is performed

with the use of “Send changes to device” button. Bluetooth should be activated on the device and the connection should be established.

If at that moment the records about the patients already exist in the device database, the program will offer to add the patients from the created list to the patient in the device or remove all the records in the device and generate completely new list (Fig. 57).

Fig. 57. Request how to act at patients list saving to device.

If you press “Yes” button, the patients just entered to the program will be added to the ones already existing in the device. If you press “No” button, the current patients list which already exists in the device, will be refreshed by the new one. If press “Cancel” button, the patients list in the device will remain unchanged.

Hearing Screening Systems (Technical Manual)

7.2.5. Service Functions

Service functions include the switching of program interface language, updating of device firmware and settings.

The program allows switching the interface language if other language was selected during the installation or it is required to switch temporarily from one language to another one. To change the program language, open “Service” menu and choose “Select Language:” item. The “Select Language” dialog box will appear on the screen (Fig. 58).

Fig. 58. Selection of program interface language.

Choose the required language and press “OK” button to set the selected language or “Cancel” button if you do not want to change the manager language.

Some manager functions can be protected by the password. To do this, specify the password in the manager settings. Click “Service” menu with the mouse and select “Settings” item. The “Settings” dialog box will appear on the screen (Fig. 59).

Fig. 59. Manager settings.

Data Exchange with Computer

To change the password (or set it for the first time), enter the password in “Password:” input box and confirm it in “Re-type password:” input box. Then press “Set password” button. If the password and its confirmation coincide, the password will be set. If you check the “Protect settings and service mode by password” checkbox, you will have to enter the password to change the settings and/or update device firmware. The “Enter password” dialog box is represented in Fig. 60.

Fig. 60. Password entering.

If the manager offers to enter the password, the further operation will be possible only after the correct password entering.

7.2.6. Firmware Updating

Using the manager, you can update the device firmware. To do this, switch on the device in the updating mode. Switch off the device if it is on. Press the most left button located under the screen and holding it, press device on/off button. As soon as the screen highlights, release the button under the screen. After that, the device will download in a special mode intended for updating (Fig. 61).

Fig. 61. The updating mode.

As soon as the device is switched on in the updating mode, you can start to the firmware updating directly. Preliminary it is required to establish the connection as described in section 7.1 “Screening System Connection to Computer”.

Hearing Screening Systems (Technical Manual)

The updating is activated by pressing “Update device firmware” button. Depending on the manager settings, the dialog box for the password entering can appear on the screen.

Only the specialists can update the device firmware as far as the device operation can be violated.

To update the software, the key file is provided which is supplied with Neuro-Audio-Screen manager distributive. It detects the device with serial number which can be updated using the function of firmware update. After the updating run, the program checks the availability of this key. In case the key is not detected or does not correspond to the device being updated, the warning message will appear on the screen (Fig. 62).

Fig. 62. The warning message concerning the key file mismatch to the device.

If such message appears on the screen, address to your dealer and inform of the serial number of the device (it is given in the text of the warning message in brackets).

If the key was accepted, the dialog box for the updating file selection will appear on the screen (Fig. 63).

Fig. 63. The selection of the updating file.

Data Exchange with Computer

The file name can differ from the one indicated in the figure. The updating files are one and the same for all versions of Neuro-Audio-Screen device. After the file selection the program will update the device firmware. During the updating it is prohibited to switch off the computer or disconnect from it. If the updating file is damaged, the error message will appear on the screen (Fig. 64).

Fig. 64. Incorrect updating file.

To receive the correct updating file, address to your dealer.

After the updating finishing, you must switch off the device and after that switch it on.

To terminate the operation with the program, press button located in the right top corner of the window.

Neuro-Audio-Screen, Neuro-Audio-Screen/OAE Hearing Screening Systems (Technical Manual)

8. Troubleshooting

Table 4. Troubleshooting

Trouble Symptom Possible Cause Way of Removal

The screening system does not switch on when supplied from the rechargeable battery.

The screening system does not switch on while supplied from the power supply unit when the rechargeable battery is discharged.

The screening system does not switch off at on/off button pressing.

The screening system switches off spontaneously at the operation from the rechargeable battery.

If you press the on/off button, the screening system switches on and after releasing it, it switches off at once.

After the switching on the screening system does not respond to the button pressing.

The printer does not respond to the “Printer” button pressing.

The printer does not print the data.

The rechargeable battery is discharged.

The power supply unit is out of order.

The power supply unit produced by other manufacturer is used

The voltage (220/230 V) in the plug is not supplied.

The process of saving or printing takes place.

The error of the screening system switching off.

The rechargeable battery is discharged.

The time of the on/off button pressing is not enough,

The rechargeable battery is discharged.

The on/off button is stuck. Press the on/off button several

The printer is switched off.

The printer is too far from the screening system.

The printer settings in the screening system are not correct.

The paper is finished. Insert the new paper roll. If the

Connect the power supply unit.

Replace the power supply unit on the operable one.

Apply the power supply unit included in the delivery set.

Insert the power supply unit to other plug with 220/230 V.

Wait for several minutes and try again.

Disconnect the power supply unit if it is connected to the device. The screening system will switch off.

The battery discharge limiting circuit activates in the screening system. Connect the power supply unit and charge the rechargeable battery.

Keep the button in a pressed position more than 3 seconds at the switching on (till the image appears on the screen).

The bound circle of the battery discharge activates in the screening system. Connect the power supply unit and charge the rechargeable battery.

times.

Switch on the printer.

Locate the printer near the screening system.

Change the settings of the printer (see the section 6. “Settings”).

paper comes out without the text, it means that it is inserted by the wrong side. Extract the paper and insert it again by the end going out the roll bottom.

Table 4. Continued

Trouble Symptom Cause Way of Removal

ABR testing provides unreliable results.

When supplied from the rechargeable battery, the device discharges quickly.

When you start any test the “Memory is full” error appears.

The power supply unit is connected to the screening system.

The rechargeable battery is not operable.

The free space is not enough to start the testing.

Disconnect the power supply unit from the screening system.

Replace the rechargeable battery in the service center of Neurosoft Ltd. Please, pay attention that the replacement of the battery must be carried out in the service center of Neurosoft Ltd. as far as this procedure results in the electronic unit opening and you may loose the warranty if you address to other service centers or open the unit yourself.

Remove the unnecessary test results (see the section 5.10.2. “Removal of Test Results”) or all the patients’ data whose exam result storing is not required (see the section 5.4. “Entering of Personal Data of New Patient, Selection of Patient from Database, Removal of Patient Data”).

Troubleshooting

In case of other troubleshooting emergence and also if the troubleshooting can not be eliminated with the use of the device control tools or by restart, it is necessary to address to the Service center of Neurosoft Ltd.

Neuro-Audio-Screen, Neuro-Audio-Screen/OAE Hearing Screening Systems (Technical Manual)

9. Technical Servicing

9.1. General Requirements

Safety measures when servicing Neuro-Audio-Screen and Neuro-AudioScreen/OAE screening systems conform to the ones described in the section

1 “Important Safety Instructions”.

The qualification requirements to the medical staff are listed in the section 4.3. “Requirements to the Personnel Conducting Mounting and Setting”.

The screening system servicing in the process of operation includes the external examination, check of jacks and cables, removal of contaminations from the units’ surface using wet fabric. These operations can be performed by the personnel executing the screening system exploitation, and in case of the trouble detection, address to the technical personnel.

The servicing of the bought articles included in the screening system is conducted according to user and technical manuals or typical rules.

When detecting the troubles it is recommended to use the information given in the section 8 “Troubleshooting”.

The screening system should be serviced while the operation on the device and also maintained regularly. The volume of technical servicing is indicated in chapter 9.2 “Maintenance Works”.

The delivery set check of Neuro-Audio-Screen and Neuro-Audio-Screen/OAE screening systems is done by conformity to the device packing report.

9.2. Maintenance Works

The maintenance works include the external examination, check of connectors and cables, removal of contaminations from the units’ surface using wet fabric.

The OAE probe tip is replaced only at clogging. Three tips for the replacement are supplied with the screening system.

9.3. Cleaning and Desinfection

These screening systems may be wiped clean with a damp cloth using a detergent or mild antiseptic solutions applied in the hospitals. Take care not to put excessive pressure on the display window. Do not allow any fluid to enter the device. Do not use the isopropyl alcohol or other dissolvent for the device cleaning.

Technical Servicing

9.4. Device Functioning Check Using Test Cavity

The check should be performed in a quiet room. To check the functioning in TEOAE mode, connect the OAE probe to the device and insert it in test cavity. Switch on the device. Run TEOAE test by pressing “Select” button. Observe the TEOAE acquisition process (see the description in section 5.6 “TEOAE Test”). As far as the test cavity does not provide the normal functioning cochlea hair cells, the test result should be “REFER”. The value of sum and difference of A&B and A-B traces should be lesser than 0 (Fig. 65).

Fig. 65. The screen view after TEOAE check finishing.

If it is not so, make sure it is quiet in the room, the OAE probe sensitivity is specified correctly (see section 6.5 “System Settings”). After the test finishing, close the test. When “Save changes?” message box appears on the screen, press “No” button.

The functioning in DPOAE mode is checked with the connected OAE probe inserted to the test cavity. Using “Up” and “Down” arrow buttons, select DPOAE test and run it by pressing “Select” button. During the frequency response calibration (see description in section 5.7 “DPOAE Test”) make sure that two similar traces of stimulus spectrum from first and second telephones appear on the screen (Fig. 66).

Neuro-Audio-Screen, Neuro-Audio-Screen/OAE Hearing Screening Systems (Technical Manual)

Fig. 66. The screen view at frequency response calibration.

After the test finishing, the test result should be “REFER”. The emission should lack for all frequencies (Fig. 67).

Fig. 67. The screen view after DPOAE test finishing.

After the test finishing, close the test. When “Save changes?” message box appears on the screen, press “No” button.

9.5. OAE Probe Check

During the operation with the device, probably you will need to check the OAE probe running order. The check should be done if you doubt about the probe operability.

Technical Servicing

To check the OAE probe, apply the test cavity supplied with the device. The run of the check while the probe is out of the test cavity will cause the wrong results!

The check is performed in special “OAE probe check” mode. In this mode the comparison of OAE probe specifications with already set specifications is carried out.

It is prohibited to press “New” button as it can lead to loss of data concerning OAE probe specifications and the check of this probe will become impossible. The given button is used only for the recording of specifications of new probe at the replacement as described below.

To check OAE probe, select “Settings” item of the main menu and press “Select” button on the device. In the appeared window select the “OAE probe check” item using device arrow buttons (Fig. 68).

Fig. 68. OAE probe check.

To run the check, press “Check” button. The message reminding of the OAE probe placing into the test cavity before the check (Fig. 69) will appear on the screen.

Neuro-Audio-Screen, Neuro-Audio-Screen/OAE Hearing Screening Systems (Technical Manual)

Fig. 69. Reminding of the necessity to perform the check in test cavity.

If you press “Close” button, the window will be closed and you will return to “Setup” menu (Fig. 68). Press “Check” button to run the OAE probe check. The check results are displayed on the screen as several bars directed up and down. The OAE probe check is performed on several frequencies, each bar corresponds to one frequency. If the bar color is green, the OAE probe is operable, in case the bar is red, the probe is faulty (Fig. 70).

Fig. 70. The results of OAE probe check.

If the OAE probe did not pass the check even on one of the frequencies and the message concerning the necessity to replace the probe appears on the screen, carry out the following operations:

 Try to extract the probe from the test cavity and insert it again. After that run the

check once again. If the probe passed the check, it means, it was inserted incorrectly.

Technical Servicing

 Try to clean the probe tip. If the OAE probe passes the repeated check, it means,

the OAE probe tip was clogged.

 In case two first operations did not work, try to replace the OAE probe tip.

 If the OAE probe tip replacement did not work, replace OAE probe.

The detailed instructions on cleaning and disinfection of the OAE probe and the removable OAE probe tip are stated in “OAE Probe OAE-02” technical manual.

After OAE probe replacement, it is required to memorize its specifications using “OAE probe check” menu item. To do this, press “New” button (Fig. 68), confirm the probe location in the test cavity, wait for the progress bar finishing and “Completed” message will appear on the screen (Fig. 71).

Fig. 71. The new OAE probe.

Neuro-Audio-Screen, Neuro-Audio-Screen/OAE Hearing Screening Systems (Technical Manual)

After that, you can press “Close” button. The message with “Remember this probe as a new one?” question will appear on the screen (Fig. 72).

Fig. 72. Question concerning the saving of new OAE probe specifications.

If you pressed by chance “Select” button and are not sure in your actions, press “No” button. To memorize the data of your new probe for its future check, press “Yes” button.

9.6. Conservation

Before the conservation the rechargeable battery should be 50% charged. The screening system components including accessories and operational documentation should be packed in separate plastic sachets and then placed in a manufacturer package.

10. Packing and Transportation

The device package should conform to the accepted one when manufacturing and delivering. In case the factory package is damaged, but the long-term screening system storage and transportation is expected, respect the following recommendations:

 the rechargeable battery should be 50% charged;

 the screening system with operational documentation should be packed in plastic

sachets and cardboard boxes according to chapter 9.6 “Conservation” of the present manual;

 the cardboard boxes should be covered by the paper tape or pressure sensitive

adhesive;

 the screening systems can be transported by all kinds of covered carries (except

non-heated airplane pods) according to rules of goods transportation for each mode of transport.

The screening systems should be transported at from +50 up to -50 °С temperature and the relative humidity not more than 90% at t=+25°С.

The screening system portage by sea transport should be done according to “Safety Regulations for Sea Transport of General Cargoes”.

The shipment type is by containers and part-load consignment.

11. Storage Regulations

The screening systems should be stored in a manufacturer package in an enclosed space at 5-40С and relative humidity 90% at 25С temperature. The air should be free from any admixtures which can cause the corrosion.

Storage Regulations

The screening systems should be put on the shelves not more than in four lines.

The rechargeable battery should be 50% charged. It is recommended to recharge it every 9-12 months. It is not recommended to store the device for more than 3 years, as the operability of the rechargeable battery may decrease.

12. Utilization of Neuro-Audio-Screen and Neuro-Audio-Screen/OAE

The device utilization is performed according to the current legislation of the area where the equipment is used. Special requirements to device utilization are not provided by the manufacturer.

13. Delivery Set and Package Data

Neuro-Audio-Screen hearing screening system,

Neuro-Audio-Screen/OAE hearing screening system

with serial number ________________________ is collected and packed according to TC 9441-057-13218158-2008 requirements.

Package report number _____________________

Package report date _______________________

Neuro-Audio-Screen, Neuro-Audio-Screen/OAE Hearing Screening Systems (Technical Manual)

The detailed information about the delivery set is described in the package report which is an integral part of the present document and should be kept along with it.

14. Acceptance Certificate

The screening system corresponds to TC 9441-057-13218158-2008 requirements and is ready for operation.

SD representative ___________________

signature

15. Delivery Certificate

The screening system is delivered to the customer ____________________________

date

Screening system was handed ___________________________________________

Screening system was accepted __________________________________________

16. Storage Data

When storing the screening system, the customer should follow the storage requirements described in the technical manual.

Information about the system storage before and in the process of operation is described in Table 6.

Table 5. Storage data.

Date of

Beginning of storage

End

of storage

Storage conditions

signature

The position, surname

and signature of the

person responsible for

the storage

17. Warranty

14.1. The manufacturer guarantees the screening system quality conformance to the TC 9441-057-13218158-2008 requirements if the rules of operation, storage, transportation and mounting prescribed in the operational documentation are observed.

Warranty

14.2. Warranty period – 24 months from the delivery date to the customer (chapter

15).

Warranty period of components exposed to wear (electrodes and cables) is 30 days.

Warranty period of OAE probe is 6 months.

Warranty is not applied to consumables (gels and pastes).

The warranty period can be prolonged for period from reclamation submission up to repair completion (chapters 18, 19).

14.3. Operation of guarantee commitment is stopped if:

 the rules of operation, storage, transportation and mounting prescribed in

the operational documentation are not observed;

 the warranty period is expired;

 the user breaks the seal without permission of the manufacturer.

14.4. The manufacturer is obliged to repair the equipment in case of breakdown during the warranty period free of charge. The repair is carried out in the service center of Neurosoft Company (5, Voronin str., Ivanovo, 153032, Russia), only if this registration certificate is provided.

Authorized European Representative Address:

Neuro-Audio-Screen, Neuro-Audio-Screen/OAE Hearing Screening Systems (Technical Manual)

Mr. Pierre Scholl

Neuromed

Chemin du tomple

84330 Le Barroux, France

Tel. +490 650 470, +622 748 384

Fax. +490 650 470

E-mail: bscholl@orange.fr

18. Reclamation Data

13.1 In case of system breakdown or faultiness in the period of warranty and also product defect detected when primary acceptance, the consumer should send written notification to Neurosoft Ltd., authorized European representative or nearest distributor. The actual list of Neurosoft Ltd. distributors is represented on the web site: http://www.neurosoft.ru/eng/useful/links.aspx. This notification should contain the following information:

 the consumer’s name and the address;

 the serial number of the stimulator (see chapter 13 of the present manual or the sys-

tem marking);

 the copy of chapter 15 of this manual or the number and the date of the invoice or

other document confirming the stimulator purchase.

 the detailed description of failures. If it is possible indicate the reasons and

circumstances preceding the fault detection (in addition it is recommended to add the test report, the exam data, photos and other materials allowing to solve the problem as soon as possible).

13.2 In case of stimulator return to the service center for the repair or the replacement, the following rules should be observed:

 it should be packed so to exclude the possibility of its damage during the

transportation;

 the notice (see item 18.1 of the chapter 18) and the present manual must be added to

the stimulator being returned.

13.3 All the reclamations, its description and taken measures should be registered in Table 7.

Table 6. Reclamation Data.

Reclamation Data

The date of

failure or

trouble

Brief description of

the trouble

The date of

reclamation

sending

Taken measures Note

appearance

Neuro-Audio-Screen, Neuro-Audio-Screen/OAE Hearing Screening Systems (Technical Manual)

19. Repair Data

Table 7. Repair Data.

Name and

code of faulty

unit

Degree of

imperfectio

completio

n of repair

Date Position,

arrival

Name of

repair works

name, signature of

Carried out

the repair

person

Accepted

after the

repair

Annex 1. Electromagnetic Emission and Immunity

Guidance and manufacturer’s declaration – electromagnetic emissions

The screening system is intended for operation in electromagnetic conditions environment described below. The customer or user of the screening system should provide the screening system operation in the specified electromagnetic conditions environment.

Emission test Compliance Electromagnetic environment – guidance

RF emissions according to СISPR 11

RF emissions according to CISPR 11

Harmonic emissions according to IEC 61000-3-2

Voltage fluctuations/ flicker emissions according to IEC 61000-3-3

Group 1 The system uses RF energy only for its internal

function. Therefore, its RF emissions are very low and are not likely to cause any interference in nearby electronic equipment.

Class В

Class А

Complies

The system is suitable for use in all establishments other than domestic and those directly connected to the public low-voltage power supply network that supplies buildings used for domestic purposes.

Neuro-Audio-Screen, Neuro-Audio-Screen/OAE Hearing Screening Systems (Technical Manual)

Guidance and manufacturer’s declaration – electromagnetic immunity

Immunity test IEC 60601

test level

±6 kV contact ±6 kV contact Electrostatic discharge (ESD) by IEC 61000-4-2

±8 kV air ±8 kV air

Compliance level Electromagnetic environment

– guidance

Floors should be wood, concrete or ceramic tile. If floors are covered with synthetic material, the relative humidity should be at least 30 %.

Electrical fast transient/burst by IEC61000-4-4

Voltage dips, short interruptions and voltage variations on power supply input lines by IEC 61000-4-11

 2 kV − for power

supply lines

 1 kV − for

input/output lines

 1 kV differential

mode

 2 kV common

mode

<5% UT (>95% dip in UT) for

0,5 and 1cycle

40% UT

(60% dip in UT) for

5 cycles

70% UT (30% dip in UT) for 25 cycles

 2 kV

Not applicable

±1 kV Surge by IEC 61000-4-5

±2 kV

20 ms

100 ms

500 ms

Mains power quality should be that of a typical commercial or hospital environment.

Mains power quality should be that of a typical commercial or hospital environment. If the user of the screening system requires continued operation during power mains interruptions, it is recommended that the screening system be powered from an uninterruptible power supply or a battery.

120% UT

(20% dip in UT) for

25 cycles

<5% UT

(>95 % dip in UT)

for 5 s

Power frequency magnetic field by IEC 61000-4-8

Note: UT is the a.c. mains voltage prior to application of the test level.

3 A/m 3 A/m Power frequency magnetic

500 ms

5000 ms

fields should be that of a typical commercial or hospital environment.

Annex 1. Electromagnetic Emission and Immunity

Guidance and manufacturer’s declaration – electromagnetic immunity

Immunity test IEC 60601

Conducted RF by IEC 61000-4-6

Radiated RF by IEC 61000-4-3

3 Vrms 150 kHz to 80 MHz outside ISM bands

3 V/m 80 MHz to 2.5 GHz

test level

Compliance level Electromagnetic environment

– guidance

3 V

3 V/m

Portable and mobile RF communications equipment should be used no closer to any part of the screening system, including cables, than the recommended separation distance calculated from the equation applicable to the frequency of the transmitter.

Pd 17.1

(80 MHz to 800 MHz);

Pd 33.2

(800 MHz to 2.5 GHz).

Field strengths from fixed RF transmitters, as determined by an electromagnetic site survey 1, should be less than the compliance level in each frequency range 2. Interference may occur in the vicinity of equipment marked with the following symbol:

Field strengths from fixed transmitters, such as base stations for radio (cellular/cordless) telephones and land

mobile radios, amateur radio, AM and FM radio broadcast and TV broadcast cannot be predicted theoretically with accuracy. To assess the electromagnetic environment due to fixed RF transmitters, an electromagnetic site survey should be considered. If the measured field strength in the location in which the system is used exceeds the applicable RF compliance level above, the system should be observed to verify normal operation. If abnormal performance is observed, additional measures may be necessary, such as re-orienting or relocating the system.

Over the frequency range 150 kHz to 80 MHz, field strengths should be less than 3 V/m. Notes:

1. At 80 MHz and 800 MHz, the higher frequency range applies.

2. These guidelines may not apply in all situations. Electromagnetic propagation is affected by absorption and reflection from structures, objects and people.

Neuro-Audio-Screen, Neuro-Audio-Screen/OAE Hearing Screening Systems (Technical Manual)

Recommended separation distances between portable and mobile RF communications

equipment and screening system

The screening system is intended for use in an electromagnetic environment in which radiated RF disturbances are controlled. The customer or the user of the screening system can help prevent electromagnetic interference by maintaining a minimum distance between portable and mobile RF communications equipment (transmitters) and the screening system as recommended below, according to the maximum output power of the communications equipment.

Separation distance according to frequency of transmitter, m Rated maximum output

power of transmitter, W

Pd 17.1

in the band

from 150 kHz up to 80

MHz

0.01 0.117 0.117 0.233

0.1 0.369 0.369 0.738

1 1.167 1.167 2.333

10 3.689 3.689 7.379

100 11.667 11.667 23.333

Notes:

1. At 80 MHz and 800 MHz, the separation distance for the higher frequency range applies.

2. These guidelines may not apply in all situations. Electromagnetic propagation is affected by absorption and reflection from structures, objects and people.

3. For transmitters rated at a maximum output power not listed above, the recommended separation distance d in meters (m) can be determined using the equation applicable to the frequency of the transmitter, where Р is the maximum output power rating of the transmitter in watts (W) according to the transmitter manufacturer.

in the band

from 80 up to 800 MHz

Pd 17.1

from 800 MHz up to 2.5

in the band

GHz

Pd 23.2

100

Neurosoft Neuro-Audio-Screen/OAE, Neuro-Audio-Screen Technical Manual

Specifications and Main Features

Frequently Asked Questions

User Manual