Fisher&Paykel NS272, NS232 Technical manual

4 (1)
Fisher&Paykel NS272, NS232 Technical manual

TECHNICAL MANUAL

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T E C H N I C A L M A N U A L

NS232

NS242

NS252

NS272

C O N ST A N T C U RRE N T

PE RI PH E RA L N E RVE ST I M U L A T O R

A N D N E R V E L O C A T O R

RevisionI

ByI.H

December2005

Copyright 2005Fisher& PaykelHealthcareLtd

AucklandNew Zealand

Page 2 of 40

INTERNATIONAL P O Box 14 348, Panmure, Auckland 6, New Zealand Tel:+64 9 574 0100 Fax:+64 9 574 0158 E-mail:

innervator@fphcare.co.nzW eb S ite: www.fphcare.com

U S A Tel: 1800 446 3908 or +1 949 470 3900 Fax:+1 949 470 3933,

AU S TRALIA Tel:+61 3 9879 502 2 Fax:+61 3 9879 52 32 ,

AU S TRIA Tel: 0800 2 9 31 2 3 Fax: 0800 2 9 31 2 2 ,

B ENELU X Tel: +31 78 644 092 4 Fax: +31 78 644 0914,

F RANC E Tel:+33 1 6446 52 01 Fax:+33 1 6446 52 2 1,

G ERM ANY Tel: +49 7182 93777 0 Fax: +49 7182 93777 99,

IRIS H

REP U B LIC Tel: 1800 409 011,

 

 

ITALY

Tel:+39 06 7839 2 939 Fax:+39 06 7814 7709,

S P AIN Tel:+34 902 013 346 Fax:+34 902 013 379,

 

 

U K (EU

Auth oris ed R ep res entativ e) Tel:+44 162 8 62 6 136 Fax:+44 162 8 62 6 146,

 

Nth n Ir e la n d Tel: 0800 132 189.

PartNumber185 040670,Revision I,IssuedDecember2005

Technical Manual forNerve Stimulatormodels:NS272,NS242,NS252 (V2.0,V1.0& 1.1) Technical Manual forNerve Locatormodels:NS232 (V2.0)

Note:ifthe unitisan NS242 with serial numbersmallerthan 031202001629oran NS252 with serial number smallerthan 031202001627,refertoNS252/242 V1.0& V1.1Software Technical Manual on page 26

Fisher & Paykel Healthcare have a policy of continuedproduct improvement andreserve the right to alter specifications without notice

Changes made to this technical manual

W heelie bin symbol added

Maximum voltage in both internal andexternal mode are betterdefined

Separate SetCurrentOffsetandAlarm Limitsbacktothe formatasperrevision G

Include Technical Manual forNS242 andNS252 with V1.0/1.1Software

NS272/ NS252/ NS242/ NS232 Technical Manual *Revision I*IssuedDecember2005

 

 

Page 3 of 40

 

TABLE OF CONTENTS

 

INTRODUCTION .............................................................................................................................

6

1

GENERAL SPECIFICATIONS –V2.0 ................................................................................

8

1.1

General Product Information (For All Nerve Stim Types) ..................................................................

8

1.2

External Mode Electrical Specifications (NS272 & NS252)...............................................................

8

1.3

External Mode Electrical Specifications (NS242 only) .......................................................................

9

1.4

Internal Mode Electrical Specifications (NS272 & NS232) ................................................................

9

1.5

Pulse Types ........................................................................................................................................

10

2

HARDW ARE DESCRIPTION -V2.0 ................................................................................

11

2.1

Control (For All Types) .....................................................................................................................

11

2.2

Supply Rails (For All Types) .............................................................................................................

11

2.3

Low Battery Detect (For All Types) ..................................................................................................

11

2.4

Beeper (For All Types) ......................................................................................................................

12

2.5

High Voltage Rail (NS272, NS252 & NS242) ..................................................................................

12

2.6

Internal Mode Constant Current Controller (NS272 & NS232) ........................................................

12

2.7

Internal Mode Leadset Monitor (NS272 & NS232) ..........................................................................

12

2.8

External Mode Constant Current Controller (NS272, NS252 & NS242)..........................................

12

3

TEST POINTS (TP)-V2.0.............................................................................................

14

3.1

For All Types .....................................................................................................................................

14

3.2

For NS272, NS252 & NS242.............................................................................................................

14

4

SELF TEST -V2.0..........................................................................................................

15

4.1

ROM Test (For All Types).................................................................................................................

15

4.2

Display Test* (For All Types) ...........................................................................................................

15

4.3

Model Test (For All Types) ...............................................................................................................

15

4.4

Button Test (For All Types)...............................................................................................................

15

4.5

Internal Mode Current Test (NS272 & NS232).................................................................................

16

4.6

External Mode Current Test (NS272, NS252 & NS242)...................................................................

16

5

ERROR CODES -V2.0 ...................................................................................................

17

6

SERVICE INFORMATION (FOR ALL TYPES)-V2.0......................................................

18

7

PART LIST -V2.0..........................................................................................................

19

7.1

For All Types .....................................................................................................................................

19

7.2

For NS272, NS252 & NS242.............................................................................................................

19

7.3

For NS232 only..................................................................................................................................

19

8

ACCESSORIES -V2.0.....................................................................................................

20

8.1

For All Types .....................................................................................................................................

20

NS272/ NS252/ NS242/ NS232 Technical Manual * Revision I* Issued December 2005

 

 

Page 4 of 40

8.2

For NS272, NS252 & NS242 ............................................................................................................

20

8.3

For NS272, NS232 ............................................................................................................................

20

8.4

Component Layout Diagram .............................................................................................................

21

APPENDIX A PRODUCT CHANGE HISTORY (FOR NS272,NS252,NS242) - V2.0...............

22

APPENDIX B PRODUCT NUMBERS (FOR ALL TYPES) - V2.0................................................

23

B1.

Model Number Explanation ..............................................................................................................

23

B2.

Serial Number Explanation................................................................................................................

23

B3.

Product Code Table ...........................................................................................................................

24

NS272/ NS252/ NS242/ NS232 Technical Manual * Revision I* Issued December 2005

 

 

 

Page 5 of 40

1

GENERAL SPECIFICATIONS – V1.0/V1.1 .....................................................................

26

1.1

Electrical Specifications –V1.0/1.1...................................................................................................

26

1.2

Pulse Types: ROM 999630013.........................................................................................................

26

1.3

Pulse Types: ROM 367020009.........................................................................................................

27

2

HARDWARE DESCRIPTION – V1.0/1.1..........................................................................

28

2.1

Control ...............................................................................................................................................

28

2.2

Reference Rail....................................................................................................................................

28

2.3

High Voltage Rail ..............................................................................................................................

28

2.4

Constant Current Control...................................................................................................................

28

2.5

Low Battery Detect ............................................................................................................................

28

2.6

Miscellaneous.....................................................................................................................................

29

3

OPERATIONAL DESCRIPTION – V1.0/1.1 .....................................................................

30

3.1

Power Down.......................................................................................................................................

30

3.2

Self Calibration ..................................................................................................................................

30

3.3

Pulse Delivery....................................................................................................................................

30

4

TEST POINTS – V1.0/1.1...............................................................................................

31

5

SELF TEST – V1.0/1.1...................................................................................................

32

5.1

ROM 999630013 ...............................................................................................................................

32

5.2

ROM 367020009 ...............................................................................................................................

33

6

SERVICE INFORMATION – V1.0/1.1..............................................................................

34

7

PARTS LIST – V1.0/1.1 .................................................................................................

35

8

ACCESSORIES – V1.0/1.1..............................................................................................

36

8.1

Component Layout Diagram..............................................................................................................

36

APPENDIX A

SERVICE NOTE – V1.0/1.1................................................................................

37

APPENDIX B

PRODUCT CHANGE HISTORY – V1.0/1.1 .........................................................

38

APPENDIX C

PRODUCT NUMBERS – V1.0/1.1........................................................................

39

C1.

Model Number And Serial Number Explanation...............................................................................

39

C2.

Product Code Table............................................................................................................................

40

NS272/ NS252/ NS242/ NS232 Technical Manual * Revision I* Issued December 2005

Page 6 of 40

INTRODUCTION

Read the operating manual carefully before operating the unit.

Electrostatic sensitive devices

Type BF Equipment (IEC Standard).

(EU WEEE Standard) Do not throw away. See distributor for appropriate disposal for electrical and electronic components

Caution Dangerous high voltages may exist within this device for up to 1 minute after removal of batteries. The microprocessor may continue to run for up to 10 minutes after removal of batteries. It is recommended that the batteries be removed at least 10 minutes prior to disassembly.

Caution This device contains CMOS and other components which are sensitive to static charges. It is recommended appropriate procedures be followed for disassembly and service.

Caution An explosion is possible if used in the presence of flammable anaesthetics. An explosion may be caused by an arc which could occur if the electrodes come into direct contact as a pulse is being delivered.

Warning In External Mode, this device is to be used with non-invasive electrodes only. If needle electrodes are used in External Mode, localised tissue burning and excessive patient discomfort may result.

NS272/ NS252/ NS242/ NS232 Technical Manual * Revision I* Issued December 2005

T E C H N I C A L M A N U A L

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V e r s i o n 2 . 0

C O N S T A N T C U R R E N T

P E R I P H E R A L N E R V E S T I M U L A T O R A N D N E R V E L O C A T O R

NS272/ NS252/ NS242/ NS232 Technical Manual * Revision I* Issued December 2005

NS272/252/242/232 V2.0 Software

Page 8 of 40

1 GENERALSPECIFICATIONS –V2.0

This part of the manual defines the technical specifications for the NS252 & NS242 Peripheral Nerve Stimulator, NS272 Peripheral Nerve Stimulator & Nerve Locator and NS232 Nerve Locator with version 2.0 software. Refer to the Operating Manual for NS272, NS252, NS242 and NS232 for detailed instructions on how to use the unit.

Any NS242 unit with a serial number smaller than 031202001629 runs on version 1.0 or 1.1 software. Any NS252 unit with a serial number smaller than 031202001627 runs on version 1.0 or 1.1 software. Please refer to the sections from page 26 onwards, for the technical specification.

1.1GENERALPRODUCT INFORMATION (FOR ALLNERVE STIM TYPES)

Battery Type: 3 times 1.5 V AA type alkaline cells (IEC type LR6)

Battery Life: Up to 160 hours continuous use with alkaline batteries Note: This figure varies greatly depending on choice of External or Internal Mode in NS272, waveforms used and current delivered.

Up to 160 hours continuous use with alkaline batteries in

NS232, NS242, NS252

Operating Temperature Range: 0 C to 35 C

Operating Humidity Range: 0% RH to 65% RH

Storage Temperature Range: -25 °C to +40 °C

Storage Humidity Range: 0% RH to 85% RH

Dimensions: NS232:

Height =167 mm, width =73 mm, depth =43 mm

NS242, NS252 and NS272

Height =175 mm, width =73 mm, depth =43 mm

Weight: 255g (185g without batteries)

1.2 EXTERNALMODE ELECTRICALSPECIFICATIONS (NS272& NS252)

Output Current Range:

0 to 160 mA

Output Current Steps

5 or 10 mA (programmable)

Tetanus Frequency

50 or 100 Hz ±10% (programmable)

Output Pulse Type:

Square, monophasic, constant current, unidirectional

Output Pulse Width:

195 ±5 µs

Output Pulse Rise Time:

<10 µs max (resistive load)

Output Pulse Fall Time:

<10 µs max (resistive load)

Maximum Internal Voltage:

420 ±10% V

Maximum Output Voltage:

350 ±10% V

Maximum Load Impedance

For TW, TOF, TET, PTC, DBS

80 mA

4 k:

160 mA

1.8 k:

 

(figures may vary depending on battery condition)

Set Current Offset:

 

0 to 80 mA

r 2.5 mA

85 to 160mA

r 5.0 mA

Alarm Limits:

r 2.5 mA of the set current

Default Program:

10 s twitch

NS272/ NS252/ NS242/ NS232 Technical Manual * Revision I* Issued December 2005

NS272/252/242/232 V2.0 Software

Page 9 of 40

Default Program Settings:

 

Tetanus Frequency

50 Hz

Maximum Current

80 mA

Current Steps

10 mA

DBS Pattern

3.3

1.3EXTERNAL MODE ELECTRICAL SPECIFICATIONS (NS242 ONLY)

Output Current Range:

0 to 80 mA

Output Pulse Type:

Square, monophasic, constant current, unidirectional

Output Pulse Width:

195 ± 5 µs

Output Pulse Rise Time:

< 10 µs max (resistive load)

Output Pulse Fall Time:

< 10 µs max (resistive load)

Maximum Internal Voltage:

420 ± 10% V

Maximum Output Voltage:

350 ± 10% V

Maximum Load Impedance

For TW, TOF, TET

80 mA

4 k:

 

(figures may vary depending on battery condition)

Set Current Offset

 

0 to 80 mA

r 2.5 mA

Alarm Limits:

r 2.5 mA of the set current

Default Program Settings:

 

Tetanus Frequency

50 Hz

Maximum Current

80 mA

Current Steps

10 mA

Note: The above specifications can not be guaranteed if the unit is used with a load impedance of more than 5 k:.

1.4 INTERNAL MODE ELECTRICAL SPECIFICATIONS (NS272 & NS232)

Output Current Range:

0 to 10 mA

Output Current Steps:

0.2 mA between 0.0 and 2.0 mA

 

0.5 mA between 2.0 and 5.0 mA

 

1.0 mA between 5.0 and 10.0 mA

Output Pulse Type:

Square wave, monophasic, constant current,

 

unidirectional

Output Pulse Width:

195 µs ± 5 µs

Output Pulse Rise Time:

< 10 µs max (resistive load)

Output Pulse Fall Time:

< 10 µs max (resistive load)

Maximum Internal Voltage:

15 V ± 10%

Maximum Output Voltage:

10 V ± 10%

Maximum Load Impedance at 10.0 mA:

1.0 k:

Set Current Offset:

 

For 0 - 2.0 mA:

± 0.15 mA

For 2.5 - 10.0 mA:

± 0.3 mA

Alarm Limits:

± 0.1 mA of the set current

Default Program:

10 s twitch

NS272/ NS252/ NS242/ NS232 Technical Manual * Revision I* Issued December 2005

NS272/252/242/232 V2.0 Software

Page 10 of 40

1.5PULSE TYPES

Twitch

±5 µs

 

 

(All Types)

Train of four

Double burst

±15 ms ±15 ms

±0.5 ms

(NS272, NS252, NS242)

(NS272 & NS252 only)

Tetanus

Post tetanic count

±0.5 ms ±0.2ms

±0.5 ms

 

(NS272, NS252) & (NS242 with 20ms at 50Hz

(NS272 & NS252 only)

only)

 

NS272/ NS252/ NS242/ NS232 Technical Manual * Revision I* Issued December 2005

NS272/252/242/232 V2.0 Software

Page 11 of 40

2 HARDW ARE DESCRIPTION -V2.0

2.1CONTROL (FOR ALL TYPES)

The core of the system is a masked ROM microprocessor, U6 which has an LCD Driver and 3 Counters/Timers on chip.

The On/Off Button, SW1, works by generating a short pulse at the reset input of U6 via C30.

The remainder of the push-buttons are arranged in a row/column scanning matrix. A diode-OR connection between the rows enables any button to bring the interrupt input of U6 low. The microprocessor is then able to determine exactly which button is being pressed by examining the status of the Port 0 outputs and the Port 2 inputs.

U6 communicates via an I²C bus serial interface to the two A/D and D/A converters, U1 and U3.

The system timing is based on a 10 ms count generated inside U6. This time base is available at TP14.

2.2SUPPLY RAILS (FOR ALL TYPES)

There are four main DC Supply Rails: +VBAT, +VCC, +VREF and +VDD. The first three are derived directly from the battery while the last is under microprocessor control.

+VBAT

This supply is the raw battery voltage and is used to supply the two switch mode power supplies for

 

+VDD and the HV Rail.

+VCC

This supply is isolated and derived from +VBAT via diode D14 and further smoothed to provide a

 

more stable voltage for the microprocessor and A/D and D/A converter ICs.

+VREF

This supply is maintained at 2.5 V by a three terminal regulator, U4 and is used as the LCD drive

 

voltage and as the reference voltage for both the A/D and D/A converters.

+VDD

This supply, nominally 15 V, is generated by a switch mode converter IC, U5 configured as a boost

 

mode DC to DC converter. The relevant components are L1, D7 and C29. The switching frequency

 

is determined by C26.

 

U5 acts to control the voltage at its VFB input at a level equal to its internal reference voltage of 1.31

 

V. Thus the voltage divider R37 and R39 determines the level of +VDD.

 

The microprocessor is able to turn U5 on by pulling its IC input high via Q20.

 

+VDD is used to power the CMOS logic and the two current controllers, to drive the two FETs and

 

supply C4 from which the Internal Mode pulses are generated.

There is an additional supply of 4 V which is used by the current controllers. This supply is produced by amplifying +VREF and is available at pin 7 of U7.

2.3LOW BATTERY DETECT (FOR ALL TYPES)

The low battery detect works in two stages. Stage one lights up the battery symbol on the LCD as a warning once the battery voltage falls to 3.3 V. Stage two shuts the microcontroller down at 2.9 V, leaving only the battery symbol on the LCD to indicate why the unit is off.

The microcontroller monitors the battery voltage in two different ways. The first is by using A/D channel 3 of U3 and the potential divider R35 and R36. The second way is by monitoring the state of the LBD output of U5. When the IC input of U5 is high, the LBD output of U5 goes low whenever its LBR input falls below its internal reference voltage of 1.31 V nominal.

The microcontroller first checks the state of the LBD output of U5. down and will cease to function further until the batteries are changed. recognise this has occurred.

If it is low then the microcontroller will shut The unit must be turned off and on for U6 to

If the LBD output of U5 is high, the processor will go on to check the voltage at the LBR input of U5 using the A/D converter. If the voltage at the LBR point is too low the battery symbol will appear on the display.

NS272/ NS252/ NS242/ NS232 Technical Manual * Revision I* Issued December 2005

NS272/252/242/232 V2.0 Software

Page 12 of 40

2.4BEEPER (FOR ALL TYPES)

LS1 is a piezoelectric loudspeaker. It is driven with an audio frequency square wave produced by an astable multivibrator, Q17 and Q18. That oscillator is turned on and off by the microcontroller via Q19.

2.5HIGH VOLTAGE RAIL (NS272,NS252 & NS242)

The high voltage rail is an electrolytic capacitor, C11, which is charged up to generate External Mode pulses.

To charge the rail, U6 activates the oscillator U2, by pulling down its reset pin, causing output Q4 to switch at a frequency determined by R15, R16 and C8. Q9 drives the primary of transformer XFORM1. The voltage at the secondary is rectified to charge C11.

When high current pulses are delivered the high voltage rail is regulated to approximately 400 V by comparator U7B. The high voltage rail is monitored by the potential divider R19, R20 and R53 and compared with +VREF. When the voltage at pin 3 of U7 reaches 2.5 V, Q24 is switched on to remove the base drive from Q8 and the oscillator is turned off.

The microcontroller also monitors the voltage across C11 using A/D channel 2 of U3 and the potential divider of R19, R20 and R53. This allows U6 to establish whether the voltage on C11 has reached the lesser of 420 V or (set current x 5000 :) and provide some control of the high voltage rail.

2.6 INTERNAL MODE CONSTANT CURRENT CONTROLLER (NS272 & NS232)

In order to deliver an Internal Mode constant current pulse, C4 must first be charged up from +VDD through R10. The microcontroller monitors the voltage across C4 via the potential divider R3, R2 and A/D channel 2 of U1.

The microcontroller then sets the level of constant current to be delivered by setting a voltage at the output of the D/A converter of U1.

At the start of the pulse the microcontroller turns Q7 on and Q1 and Q2 off. Under those conditions, the voltage at the collector of Q6 will increase depending on the difference between the voltages at the emitters of Q6 and Q5. The Q6 collector voltage determines how much current the Darlington configuration of Q22 and Q4 conducts. The collector current of Q4 is the current delivered at the output and it develops a proportional voltage across R1. Thus the Q5, Q6 pair maintains the output current equal to the voltage at the output of the D/A converter divided by the resistance of R1.

A/D channel 0 of U1 monitors the voltage across R1. By doing this, U6 is able to determine whether the correct current is being delivered at all times.

Q2 holds Q22 and Q4 in their off-state between pulses and while the unit is switched off, to avoid any output leakage currents.

2.7INTERNAL MODE LEADSET MONITOR (NS272 & NS232)

The microcontroller is able to determine whether the Internal Mode leadset is connected to the unit by monitoring the voltage at A/D channel 3 input of U1.

2.8 EXTERNAL MODE CONSTANT CURRENT CONTROLLER (NS272,NS252 & NS242)

An External Mode pulse is generated in a similar way to the Internal Mode pulse.

In order to deliver an External Mode constant current pulse, C11 must first be charged up. The microcontroller monitors the voltage across C11 via the potential divider R19, R20, R53 and A/D channel 2 of U3.

The microcontroller then sets the level of constant current to be delivered by setting a voltage at the output of the D/A converter of U3.

NS272/ NS252/ NS242/ NS232 Technical Manual * Revision I* Issued December 2005

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