Medtronic MMT-7900 User Manual

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Page 1

Guardian

Continuous Glucose Monitoring System

REF MMT-7900

User Guide

Page 2

Guardian

, MiniMed® and Sen-serter® are registered trademarks of Medtronic MiniMed.

Com-Station™, Shower-Pak™, Solutions™ Software are trademarks of Medtronic MiniMed.

BD Logic™ is a trademark of Becton, Dickinson and Company Detachol

is a registered trademark of Ferndale Laboratories, Inc.

Polyskin

is a registered trademark of the Kendall Healthcare Products Company.

CaviCide

is a registered trademark of the Metrex Research Corporation.

IV3000

is a registered trademark of Smith & Nephew, Inc.

YSI 2300 STAT Plus™ is a trademark of YSI Incorporated.

The Guardian RT System is covered by the following Patent Nos: 5,390,671; 5,391,250; 5,568,806; 5,586,533; 5,586,553; 5,777,060; 5,779,665; 5,786,439; 5,851,197; 5,882,494; 5,954,643; 6,093,172; 6,248,067; 6,293,925; 6,368,141; 6,418,332; 6,424,847; 6,462,162; 6,520,326; 6,607,509; DES 433,755.

The Guardian RT System is covered by other/pending patents.

6024979-012 072505

0459/0976

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Table of Contents i

Table of Contents

Chapter 1: Introduction ......................... 1

System Function....................................................... 2

System Components .................................................. 2

Glucose Sensor.................................................................... 2

Transmitter .......................................................................2

Monitor............................................................................. 3

Monitor Buttons ..................................................................3

Monitor Button Functions .......................................................4

Monitor User Guide Terms ......................................................4

Test Plug.......................................................................... 5

Sen-serter ........................................................................ 5

Availability............................................................. 5

Help..................................................................... 6

Record Keeping........................................................ 6

Warranty ............................................................... 6

User Safety .................................... ......................... 7

Indications for Use...............................................................7

Contraindications ................................................................7

Warnings...........................................................................8

Precautions........................................................................ 9

Adverse Reactions.............................................................. 11

Symptoms of Hypoglycemia .................................................. 11

Symptoms of Hyperglycemia ................................................. 12

Blood Glucose Meter........................................................... 12

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ii Table of Contents

Chapter 2: Getting Started .....................13

Quick-Reference Guide............................................. 13

Start-Up Process..................................................... 17

Installing the Batteries ....................................................... 17

Turning On the Monitor........................................................ 19

Turning Off the Monitor....................................................... 19

Home Screen.................................................................... 19

The Main Screens.................................................... 20

Programming the Monitor..................................................... 21

Setting the Language ......................................................... 22

Setting the Time Display Format ........................................... 23

Setting the Time and Date................................................... 24

Clearing the Glucose History ................................................ 26

Setting the Glucose Unit ..................................................... 29

Setting the Low Glucose Alert............................................... 30

Setting the High Glucose Alert.............................................. 33

Setting the Alert Type........................................................ 36

Entering the Transmitter ID ................................................. 37

Inserting the Sensor................................................ 39

Sensor Storage and Handling ................................................ 44

Sen-serter Maintenance...................................................... 44

Affixing the Transmitter............................................ 45

Searching for the Transmitter............................................... 46

Connecting the Sensor to the Transmitter ................................ 47

Sensor Initialization........................................................... 48

Sensor Calibration............................................................. 48

Calibration Pending........................................................... 50

No Sync ......................................................................... 50

Replacing the Glucose Sensor ..................................... 51

Removing the Sensor.......................................................... 51

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Table of Contents iii

Chapter 3: Routine Operation.................. 53

Glucose History ...................................................... 53

Entering Meter BG for Calibration................................ 55

BG Due................................................................ 56

Enter BG......................................................................... 57

Calibration Pending............................................................ 57

No Sync .......................................................................... 58

Replacing the Glucose Sensor ................................................ 58

Events.......................................... ........................59

Units of Insulin Taken ......................................................... 60

Carbohydrate Amount ......................................................... 61

Duration of Exercise ........................................................... 61

Other Events.................................................................... 62

Glucose Alarm History...............................................63

Search .................................................................65

Signals .................................................................65

The Snooze Option...................................................66

Chapter 4: Troubleshooting and Alarms ........ 67

List of Alarms........................................................ 68

No ID ............................................................................. 68

High .............................................................................. 69

Low............................................................................... 70

Check Sensor.................................................................... 71

Low Batt......................................................................... 72

Off/No Power................................................................... 73

Service C60/61 ................................................................. 74

Re Init............................................................................ 74

No Sync .......................................................................... 75

Cal Err............................................................................ 76

Key Held......................................................................... 77

Enter BG......................................................................... 77

Set Time......................................................................... 78

Replace Sensor ................................................................. 79

System Alarms....................................................... 80

Test Plug Procedure ................................................ 81

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iv Table of Contents

Chapter 5: Performance Characteristics .......83

Performance Results................................................ 84

Accuracy of Guardian RT Readings ............................... 85

Precision of Guardian RT Readings ............................... 89

Low and High Alerts................................................. 89

The Low Glucose Alert ....................................................... 90

The High Glucose Alert........................................................ 91

Guardian RT Sensor Performance and Calibration .............. 92

Affects of Calibration Frequency ................................. 94

Time-Elapsed Plots.................................................. 95

Chapter 6: System Maintenance ................99

Belt Clip .............................................................. 99

Installation ...................................................................... 99

Removal........................................................................ 100

Leather Case ....................................................... 100

Protection from Water ............................................100

Protection from Impact ...........................................101

Protection from High and Low Temperatures..................101

Cleaning the Monitor............................................... 102

Cleaning the Transmitter ......................................... 102

Cleaning the Sen-serter ........................................... 104

Interference from Electrical Equipment ........................ 105

Ordering Supplies................................................... 106

Product Specifications............................................. 107

FCC Notice for the Monitor ....................................... 110

FCC Notice for the Transmitter .................................. 110

Icon Table ........................................................... 111

Fixed Elements Table.............................................. 113

Appendix........................................ 115

Electromagnetic Compatibility Compliance Information .... 115

Glossary ........................................ 121

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Introduction

Congratulations on buying one of the most exciting devices in the field of diabetes care! The Medtronic MiniMed Guardian® RT (Real Time) System (M MT-7900) continuously monitors glucose levels, provides real-

time glucose values, and gives high and low glucose alerts. The Guardian RT uses three separate components—Sensor, Transmitter, and Monitor—to measure and display glucose levels in persons with diabetes. The Sensor is inserted in the abdomen in fluid under the skin (Interstitial Fluid) and is attached to the Transmitter. The Transmitter takes information from the Sensor and sends it to the Monitor. The Monitor is a device that can store this information for real-time review, or can download it to a personal computer using a Medtronic MiniMed Com-Station™ (MMT-7301) and the Guardian Solutions™ Software (MMT-7315). This information is used by you and your doctor to identify glucose patterns and to improve your diabetes management.

We know you are ready to start, but before you do, please read the following user guide to learn all about the Guardian RT. Chapter 1 gives a general overview of the system. Chapter 2 offers step-by-step instructions to get you started. Chapter 3 explains the routine operation of the Guardian RT. Chapter 4 walks you through the system alarms and troubleshooting approach. Chapter 5 goes over performance characteristics, and Chapter 6 covers system maintenance and other important information.

Figure 1.1

Monitor

Transmitter

Sensor

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System Function

The Guardian RT measures glucose levels in interstitial fluid: the fluid found between the body’s cells. It is from this fluid that cells get oxygen and nutrients, including glucose. Glucose levels in interstitial fluid typically match glucose levels in the blood. The system gives real-time interstitial fluid glucose values on demand (updated every five minutes). The system also features low glucose and high glucose alerts that are triggered once limits you have preset are reached. Data from the Sensor (which is placed under the skin into the interstitial fluid) triggers the low blood glucose alert if your Sensor glucose value is less than or equal to the preset limit. The high blood glucose alert is triggered if your Sensor glucose value is greater than or equal to the preset limit. Glucose values are calculated and displayed based on the blood glucose reference values entered periodically into the Monitor for calibration.

NOTE -

Before taking action based on glucose values or High and Low glucose alerts, check your blood

glucose using a home glucose meter available from your doctor or pharmacy.

System Components

Glucose Sensor

Figure 1.2

The Sensor (MMT-7002) is inserted through the skin into interstitial fluid. The Sensor gives off a signal that is related to the amount of glucose in the interstitial fluid at the insertion site. (See Figure 1.2.)

Transmitter

Figure 1.3

The Transmitter (MMT-7700) connects to the Sensor and is fixed to the skin with medical tape. The Transmitter receives and processes signals from the Sensor, and it sends the signals by radio frequency to the Monitor. (See Figure 1.3.)

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Introduction 3

Monitor

The Transmitter sends Sensor data in the form of radio signals to the Monitor (MMT-7901) about every 5 minutes. The Monitor stores this information and uses it to provide real-time glucose values and to trigger low or high glucose alerts. This information can also be downloaded for analysis to a personal computer by means of a Medtronic MiniMed Com-Station™ (MMT-7301) and the Guardian Solutions™ Software (MMT-7315).

The system is calibrated by entering into the Monitor blood glucose values from a home glucose meter. Six hours before a meter BG entry for the purpose of calibration is due, the word CAL will appear on the Monitor screen. This icon will remain on the display until you enter a meter value. If you do not enter a meter value within 12 hours of the last entry, an ENTER BG alarm is triggered. This alarm is also triggered if a calibration has not been done in the last 8 hours since the first calibration. For best performance, enter a meter value every 6 hours. A minimum of one meter value must be entered at least every 12 hours into the Guardian RT for the real-time glucose display and the low and high glucose alerts to work.

Monitor Buttons

The Monitor is controlled by 5 buttons. (See Figure 1.4.) Always press the Monitor buttons slowly and firmly.

Figure 1.4

Up Arrow

Down Arrow

Backlight Button

Select Button

Activate

Button

On/Off Button

Display

Screen

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Monitor User Guide Terms

The following terms and icons are used to describe the Monitor in this User Guide:

➠ Press means to push and release the button. ➠ Hold means to push and keep pressure on the button. ➠ Flashing words or numbers (but not icons) on the screen mean that you can change this information

in the Monitor.

➠ Information that cannot be changed appears on the screen in characters that do not flash. ➠ Button names are always UPPERCASE and bold, e.g., ACT and SEL. ➠ Screen names are always UPPERCASE, e.g., HOME and HIGH.

Monitor Button Functions

This button turns the Monitor On or Off.

SEL

The SEL (Select) button scrolls through the menu screens. It is used with the ACT button to clear alarms/alerts.

ACT

The ACT (Activate) button lets you make changes to programming, save information to memory or clear alarms/alerts. You will hear a beep when you press ACT to confirm the selection.

Up and Down

Arrows

The Up and Down arrows are used to change values or settings. Press either arrow once to pick the next highest or lowest value. Hold down either arrow to scroll through the list of values. Hold down either arrow for more than 5 seconds to speed up scrolling. When you reach the wanted value press ACT to set. If you do not press ACT within 10-20 seconds, the display will go back to the default screen.

Located on the Down arrow and used from the HOME screen, the Backlight button turns On or Off the screen light, letting you see the display at night or in dim lighting. The light will stay on for about 15 seconds after the last button press.

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Introduction 5

Test Plug

Figure 1.5

The Test Plug (MMT-7400) is a device used to troubleshoot the Guardian RT system. (See Figure 1.5.) If there is a problem with the Guardian, it can give information that will tell if the Sensor, Transmitter, or Monitor are working correctly. See Chapter 4: Troubleshooting and Alarms for more details.

Sen-serter

Figure 1.6

The Sen-serter® (MMT-7500) is a spring-loaded reusable device that inserts the Sensor (MMT-7002) at an angle under the skin and into the interstitial fluid. (See Figure 1.6.)

Availability

The Guardian RT and supporting products are available from Medtronic MiniMed and authorized distributors.

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Help

Medtronic MiniMed provides a 24-Hour Product Help Line in the United States and Canada. The help line is staffed with personnel trained in the set-up and use of the Guardian RT system, and they are able to answer your questions. When calling, please have the Guardian RT system and this User Guide with you.

Record Keeping

A serial number is found on the back of the Monitor and on the top of the Transmitter. Please enter the serial numbers and purchase date in the table below.

Warranty

Please read the enclosed warranty card carefully as it lists the terms of coverage.

Department Telephone Number

24-Hour Product Help Line

U.S. and Canada

800-MINIMED (800-646-4633) or 818-576-5555

International

Contact your local sales office

Medtronic MiniMed Website

www.minimed.com

Serial Number Purchase Date

Monitor: Transmitter:

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Introduction 7

User Safety

Indications for Use

The Guardian RT is indicated for continuous or periodic monitoring of glucose levels in the fluid under the skin, in adults (ages 18 and older) with diabetes mellitus, for the purpose of improving diabetes management. It alerts if a glucose level falls below, or rises above, preset values. Values are not intended to be used directly for making therapy adjustments, but rather to provide an indication of when a finger stick may be required. All therapy adjustments should be based on measurements obtained using a home glucose monitor and not on Guardian RT values.

The Guardian RT provides real-time glucose values that allow users to track patterns in glucose concentrations and to possibly identify episodes of low and high blood glucose. It also stores the data so that it can be analyzed to track patterns. Glucose data can be further downloaded to PC software for analysis of historical glucose values.

Contraindications

Use of the Guardian RT is not recommended for persons whose impaired vision or hearing does not allow

full recognition of the Guardian RT signals and alarms/alerts.

The Sen-serter is not indicated for use with product other than the Glucose Sensor. Medtronic MiniMed

cannot guarantee this product’s safety and/or efficacy if other sets are used.

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Warnings

Monitor

The Monitor and Transmitter need to be kept within 6 feet (approximately 2.0 meters) of each other to ensure that communication is not interrupted.

Transmitter

The Transmitter should be removed if irritation or reaction to the Transmitter tape develops. The Transmitter should be disconnected from the Sensor while traveling on an aircraft, or if it interferes

with another transmitting device.

Sensor/Sen-serter

The Sensor may create special needs regarding your medical conditions or medications. Please discuss these conditions and medications with your doctor before using the Sensor. Bleeding, swelling, irritation and/or infection at the insertion site are possible risks associated with inserting the Sensor and may result from improper insertion and maintenance of insertion site.

After insertion, wait 2-3 minutes before attaching the Transmitter to watch for bleeding at the insertion site. If bleeding occurs, apply steady pressure using a sterile gauze or clean cloth for up to 3 minutes.

If bleeding stops:

1. Attach the Sensor to the system connector.

If bleeding does not stop:

CAUTION: Do NOT attach the Sensor to the system connector.

1. Remove the Sensor and discard.

2. Check the site for redness, bleeding, irritation, pain, tenderness, or inflammation and treat

accordingly.

3. Insert a new Sensor in a different location.

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Introduction 9

The Sensor should be removed if redness, pain, tenderness, or swelling develop at the insertion site, or if

you experience unexplained fevers. Check site often for these conditions and to make sure Sensor is still

in place, especially before going to bed and upon waking.

Confirm symptoms of low blood glucose and high blood glucose, as well as displayed glucose values and

alerts, with a home blood glucose meter available from your doctor or pharmacy.

The Sensor is sterile and non-pyrogenic unless the package has been opened or damaged. Do not use any

Sensor if its sterile package has been previously opened or damaged. Always inspect packaging for

damage prior to use. Do not use a Sensor that exceeds the expiration date printed on the package.

Remove plastic needle cover before inserting Sensor.

If Sensor is not securely placed in Sen-serter prior to insertion, pain or minor injury may occur.

Never point loaded Sen-serter toward any body part where insertion is not desired.

Precautions

Monitor

You should be trained by your healthcare professional on how to program and operate the Monitor and

respond to alarm/alert conditions before using the system.

Do not expose the Monitor to water. The Monitor should be set aside or placed in a Shower-Pak™ (MMT-

117) before doing activities in which the Monitor would be expected to get wet.

Contact sports or other activities may damage the Monitor and should be avoided. Prior to exercising,

make sure the Sensor is firmly attached.

If the Monitor shows a NO POWER alarm on the display, there will be an immediate shut-off as soon as the

alarm is acknowledged, and data collection will automatically stop. Batteries must be replaced

immediately to avoid the need for Sensor replacement and potential loss of data stored in memory. Upon

battery replacement, a SEARCH must be performed. (Refer to Searching for the Transmitter section in

Chapter 2: Getting Started.)

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Although the Monitor is tested and complies with the applicable standards, the use of the Monitor in close proximity to strong electromagnetic sources, such as MRI equipment, television transmitters, highvoltage power lines, or high-power radio transmitters is not recommended.

Keep the Monitor in its leather case to protect against electrostatic discharges that are common in cold and dry climates.

Transmitter

Establish a rotation schedule for choosing each new Transmitter site. Avoid sites that are constrained by clothing, scar tissue, accessories or subjected to rigorous movement during exercise.

Sensor

Always wash hands with soap and water before opening the Sensor package and handling Sensor. After opening the package, avoid touching any Sensor surfaces that will come in contact with the body. These surfaces include: the Sensor, needle, connector adhesive surfaces and tape.

Prior to inserting the Sensor, select insertion site, and use antiseptic to cleanse site. Allow area to dry. If you also wear an insulin pump, make sure that the Sensor insertion site is at least three (3) inches

(7.62 cm) away from the insulin infusion site. If you inject insulin, you should give injections at least three (3) inches (7.62 cm) away from the Sensor insertion site. When replacing Sensor, select new insertion site at least two (2) inches (5.08 cm) from previous site.

Do not insert Sensor through tape, and do not use sticky preps before insertion. After inserting the Sensor and attaching the Transmitter, cover the Sensor site with sterile/occlusive

dressing, such as IV3000® (MMT-174). Be aware that excessive perspiration can loosen dressing. Check dressing after any activity in which

excessive perspiration has resulted. Establish a rotation schedule for choosing each new Sensor site. Avoid sites that are constrained by

clothing, scar tissue, accessories or subjected to rigorous movement during exercise. Dispose of used Sensors and introducer needles in a sharps container after single use. Do not clean or

resterilize, and do not recap needle with Sensor needle cover.

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Introduction 11

Adverse Reactions

Operation of the Medtronic MiniMed Guardian RT requires the insertion of a Glucose Sensor into the skin.

Bleeding, swelling, bruising, or infection at the Sensor insertion site are possible risks of Sensor use. The

Sensor should be removed if redness, pain, tenderness, or swelling develop at the insertion site. The

Transmitter should be removed if irritation or a reaction to the Transmitter tape develops. In the event

of any adverse reaction associated with this system, U.S. and Canadian customers please contact your

doctor and the Product Help Line at 800-MINIMED (800-646-4633) or 818-576-5555. All other international

customers please contact your local sales office.

Symptoms of Hypoglycemia

Hypoglycemia (low blood glucose) may occur in persons with diabetes who take insulin or certain oral

medications. There are symptoms linked to low blood glucose that should not be ignored no matter how

mild they are, even if the Guardian RT does not display a low glucose value or give a low glucose alert. If

you have any of the following symptoms, take a meter blood glucose reading, and check with your doctor

before you treat:

➠ sweating ➠ confusion ➠ hunger

➠ dizziness ➠ headache ➠ blurred vision

➠ palpitations ➠ speech impairment

➠ trembling ➠ drowsiness

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Symptoms of Hyperglycemia

Hyperglycemia (high blood glucose) may develop if you do not have enough insulin. There are symptoms linked to high blood glucose that should not be ignored no matter how mild they are, even if the Guardian RT does not display a high glucose value or give a high glucose alert. If you have any of the following symptoms, take a meter blood glucose reading, and check with your doctor before you treat:

Blood Glucose Meter

Be sure to periodically maintain your home blood glucose meter periodically, and check its accuracy when using it for calibration of your Guardian RT system. Check with your BG meter’s user guide for information on meter coding, calibration, and testing against solutions and other laboratory instruments. Ask your doctor about verifying the relative accuracy of your meter, or to find a BG meter that is right for you.

➠ fatigue ➠ blurred vision ➠ excessive thirst

➠ hunger ➠ frequent urination

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Chapter 2

Getting Started

Now that you are ready to use the Medtronic MiniMed Guardian RT, there is a Start-Up process that you must follow

to ensure a rewarding glucose sensing experience. Read the Quick-Reference section below, as it outlines the steps needed to successfully operate the Guardian RT. Use this section as a general reference guide. But please read the rest of this chapter carefully for the detailed steps needed to Program the Monitor and Set up the Sensor.

NOTE -

If the ACT button has not yet been pressed, mistakes in programming often can be fixed by

simply waiting 10-20 seconds without pressing any buttons.

Quick-Reference Guide

PROGRAM MONITOR

➠ Set Language ➠ Select Time Display Format ➠ Set Date and Time ➠ Clear Glucose History ➠ Set Gluco se Units ➠ Set Low Alert ➠ Set High Alert ➠ Set Alert Typ e ➠ Enter Transmitter ID

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14 Chapter 2

SENSOR START



Clean Site



Insert Sensor



Affix Transmitter to Skin



Perform Search



Connect Sensor to Transmitter



Verify Initialization



Place Tape Over Sensor and Connector



Enter BG for Calibration at End of Initialization

Page 21

Getting Started 15

ROUTINE OPERATION



Review Glucose Sensor Values



Check Sensor Signals Periodically



Check BG Due Status



Enter BG Values for Calibration



Enter Events: Insulin, Meals, Exercise, Others



Set High Alarm Snooze as Needed



Modify Alarm Limits for Overnight and Daytime



Address Alarms and Follow Up Actions



Enter BG Values for Calibration in Response to High and Low Alarms



Check Sensor Site Periodically



Replace Tape and Secure Transmitter As Needed



Replace Sensor at 72 Hours



Code BG Meter When Changing Test Strip Lots, and Run Controls

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16 Chapter 2

LIST OF ALARMS See Chapter 4, Troubleshooting and Alarms, for More Information.



No ID (C52): Missing Transmitter ID in Setup



Sensor Glucose HIGH: Sensor Glucose Above High Setting



Sensor Glucose LOW: Sensor Glucose Below Low Setting



Check Glucose Sensor (C54): Sensor Current Outside Range



Low BATT: Monitor Batteries are Running Low



Off/No Power: Monitor Batteries are Used Up



Service C60/C61: Transmitter Battery is Low or Used Up



Re Init C62: Setup Information Not Received by Monitor



No Sync (C76): Monitor Lost Communication with Transmitter



Cal Err (Calibration Error): Last BG Entry Differed from Expected Reading



Key Held (C77): Button Pressed for Too Long/Button Stuck



Enter BG (C78): Enter New BG Value for Calibration



Set Time (C79): Time Reset to Default



Replace Sensor (C80): No More Glucose Readings/End of Sensor Life



System Alarms (F##): System Diagnostic Problem



Test Plug Procedure

Page 23

Getting Started 17

Start-Up Process

Installing the Batteries

The Monitor uses two (2) AAA alkaline batteries. When changing out used-up batteries, make sure to use

new batteries. The Monitor will alert you when a battery change is needed. Batteries should be installed

right after unpacking the Guardian RT.

NOTE -

Use only disposable AAA alkaline batteries in the Monitor. Do not use rechargeable batteries

or other battery types. These batteries can damage the Monitor or affect Monitor operation.

If batteries are not changed within 10 minutes of taking out a used-up set, an alarm will be triggered, and the Sensor will have to be replaced. (See Chapter 4: Troubleshooting and Alarms.) Be sure to have a new set of batteries ready when replacing the old set.

In order to properly save and keep stored Monitor information, always turn the Monitor off before changing batteries.

4. Find the battery compartment on the back side of the Monitor.

5. With the screwdriver provided, loosen the screw while holding the Monitor’s battery compartment

lid. Do not try to fully remove the screw; it is meant to stay attached to the lid.

6. Take off the battery compartment lid.

7. If you are changing batteries, first pull on the ribbon to loosen. Next, take out the old batteries with

your fingers.

8. Place the battery strap around the new batteries. Refer to the diagram on the inside of the battery

compartment lid.

CAUTION: If the batteries are put in with the positive and negative

terminals switched, they will become very warm, and the Monitor will not work. Carefully, place the batteries in the Monitor correctly.

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18 Chapter 2

9. Put in the new batteries, following the diagram on the bottom of the compartment. (See Figure 2.1)

Figure 2.7

10.

Place the battery compartment lid back into place, aligning it correctly against compartment seal.

11. With the screwdriver, tighten the screw to close the battery compartment and hold the lid in place.

Do not overtighten lid.

NOTE -

After changing the batteries, all programmed settings should be checked, and changed if

needed.

NOTE -

If Monitor display is blank, or not responding to button presses, U.S. and Canadian customers please contact the Product Help Line at 800-MINIMED (800-646-4633) or 818-576-5555. All other international customers please contact your local sales office.

CAUTION: Batteries must be recycled or disposed of properly. Do not

dispose of batteries by putting them in fire.

Page 25

Getting Started 19

Turning On the Monitor

NOTE -

The Monitor will turn on and automatically run a self-test when batteries are put in correctly.

NOTE -

If the Monitor does not turn On, and before that you got a LOW BATT alarm, change out the

batteries.

1. Press the On/Off ( ) button.

2. The Monitor will beep and vibrate, display the software version used, and display the HOME screen.

NOTE -

Every time the Monitor is turned on, a test is run. If a problem is found, it will trigger an

audible (or vibrating) alarm and an error message. See Chapter 4: Troubleshooting and Alarms.

Turning Off the Monitor

Information, including the Sensor values gathered before the Monitor was turned off, will be saved in the Monitor. No new information will be collected.

1. Press the On/Off button.

2. The Monitor will beep or vibrate, and CONFIRM will blink on the screen.

3. Press ACT to confirm. If you don’t, the Monitor will stay on and return to the HOME screen.

4. The screen will go blank when successfully turned off.

Home Screen

The HOME (Time of Day) screen for the Monitor shows the time in the upper left-hand corner. Once the Search procedure has been successfully done, the antenna icon ( ) will show that the Monitor is getting information from the Transmitter, i.e., telemetry has been achieved. The antenna icon will stay on the screen as long as there is telemetry. This screen, as shown to the right, is displayed if no buttons have been pressed or no alarms/alerts have been triggered. From any screen, if no buttons are pressed, the Monitor will “time out” and return to the HOME screen.

12:00 PM

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20 Chapter 2

The Main Screens

There are eight main screens in the Guardian RT Monitor: HOME (TIME AND ALARM), GLUCOSE HISTORY, METER BLOOD GLUCOSE (BG), EVENTS, GLUCOSE ALARMS HISTORY, SEARCH, SIGNALS and SETUP. You can enter any of these screens from the one before by pressing SEL and then ACT. Figure 2.2 describes the screen flow. These screens will be explained in detail in Chapter 3: Routine Operati on.

Figure 2.8

SETUP

12: 00

SIGNALS

GLUCOSE

SENSOR

events

GLUCOSE

mg/dl

_ _ _

SEL

11:57

CONFIRM

--:--

BG DUE

SNOOZE

11:57

SEL

SET-UP

SUB-SCREENS

UP ARROW

SEL

ACT

UP ARROW/

SEL

UP ARROW

POWER

OFF

HOME SCREEN

GLUCOSE

ALARMS

meter bg

mg/dl

_ _ _

SEL

ACT

BLANK SCREEN/

OFF

3:00

NOW

Page 27

Getting Started 21

Programming the Monitor

There are ten Setup subscreens in the Guardian RT Monitor: LOW, HIGH, ALERT, SET TIME, DISPLAY, UNIT, TRANS ID, CLEAR, LANGUAGE, and EXIT. To get to these subscreens: From the HOME Screen (See Figure

2.2) press the SEL button 7 times to reach the SETUP Screen, and press the ACT button to enter. Then press SEL to scroll through the subscreens and ACT to enter any given one. The subscreens have to be programmed before starting on the Guardian RT. This process will be explained in the following pages. Figure 2.3 describes the subscreen flow.

SET-UP SUB-SCREENS

Figure 2.9

NOTE -

Always set time and date before using the Monitor for the first time.

clear

TRANS ID

SET TIME

ALERT

UNIT

SEL

DISPLAY

language

EXIT

SEL

ACT

SEL

MAIN MENU

SEL

LIMIT

GLUCOSE

LOW

GLUCOSE LIMIT

HIGH

12:00

12:H r

GLUCOSE

SETUP

ACT

mg/dl

_ _ _

HIST:

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22 Chapter 2

Setting the Language

The Guardian RT offers the choice of displaying Monitor information in seven different languages: English, French, Spanish, Italian, Swedish, German and Dutch.

From the HOME screen:

1. Press SEL 7 times to get to the SETUP screen.

2. Press ACT once.

3. Press SEL 8 times to get to the LANGUAGE screen.

4. Press ACT. The screen will display the word ENGLISH blinking.

5. Use Up or Down arrow button to scroll through the different languages. Each language will appear

blinking until selected when the ACT button is pressed. a. With each press of the Up arrow button, this is the language order as it appears on the screen:

English —> French —> Spanish —> Italian —> Swedish —> German —> Dutch

b. With each press of the Down arrow button, this is the language order as it appears on the screen:

English —> Dutch —> German —> Swedish —> Italian —> Spanish —> French

6. Press ACT to choose the desired language.

7. The display will change to the EXIT screen. The screen information will now be shown in the chosen

language.

NOTE -

If when on a language screen SEL is pressed instead of ACT, the display will go to the EXIT

screen, and the language change will not be made.

8. Press ACT to return to the HOME screen.

LANGUAGE

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Getting Started 23

Setting the Time Display Format

The Monitor gives you a choice of using either 12 or 24-hour time format. From the HOME screen:

1. Press the SEL button 7 times until the SETUP screen appears.

2. Press the ACT button once to get to the SETUP sub-screens.

3. Press the SEL button 4 times until the DISPLAY sub-screen appears.

4. Press the ACT button once and the upper left-hand corner of the screen will be blinking. The word

SET will appear under the blinking number. Use the Up or Down arrow button to choose either “12” (AM/PM) or “24” (International) which is the time format to be used.

5. Press the ACT button to set the time format.

6. Press the SEL button and the Monitor will go to the UNIT sub-screen. Press SEL 4 times to go to EXIT.

Press ACT to go back to the HOME screen.

DISPLAY

12:HR

DISPLAY

24:Hr

DISPLAY

12:Hr

SET

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24 Chapter 2

Setting the Time and Date

NOTE -

All steps to set up the Time and Date must be done, or the time and date will not be saved.

NOTE -

If the SEL button is pressed while in a Time/Date subscreen, the display will automatically

change to the Time Display option.

From the HOME screen:

1. Press the SEL button 7 times until the SETUP screen appears.

2. Press the ACT button once to get to the SETUP sub-screens.

3. Press the SEL button 3 times until the SET TIME sub-screen appears.

Setting the Current Hour

1. Press the ACT button once, and the word HOURS will appear. The first two digits will be blinking,

and the word SET will appear.

2. Use the Up or Down arrow button to choose the correct hour. If using the 12-hour format, make sure

the screen shows the correct AM or PM text. For example: AM is displayed and you need PM; press the Up or Down arrow to scroll through the times until the correct time with PM appears.

3. If using the 24-hour time format, choose hours between “0” and “23.”

4. Press the ACT button once, and the word MINUTES will appear.

SET TIME

00:00

SET TIME

12:oo

HOURS

00:00

HOURS

12:oo

SET

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Getting Started 25

Setting the Current Minutes

1. The word MINUTES will now appear with the last two digits of the time blinking.

2. Use the Up or Down arrow button to choose the current minute from “00” to “59.”

3. Press the ACT button once, and the word YEAR will appear.

Setting the Current Year

1. The YEAR will now appear with the number “00” blinking in

the upper right-hand corner of the screen. The starting year is

2000.

2. Use the Up or Down arrow button to choose the last two digits

of the current year. For example: “00” is entered for the year 2000, and “04” is entered for the year 2004, etc.

3. Press the ACT button once, and the word MONTH will appear.

Setting the Current Month

1. The word MONTH will now appear with the number “01”

blinking in the upper right-hand corner of the screen. Use the Up or Down arrow button to choose the digits for the current month. For example: “01” is entered for the month of January, “02” is entered for the month of February, “03” is entered for the month of March, etc.

2. Press the ACT button once, and the word DAY will appear.

MINUTES

00:00

MINUTES

12:oo

SET

YEAR

12:00

SET

12:00

SET

MONTH

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26 Chapter 2

Setting the Current Day

1. The word DAY will now appear with the number “01” blinking

in the upper right-hand corner of the screen.

2. Use the Up or Down arrow button to choose the digits for the

current day of the month, from 1 to 31.

3. Press the ACT button once to save date and time values

chosen.

4. The current time and date will appear briefly, and the

Monitor will go to the DISPLAY sub-screen. Press SEL 5 times to go to EXIT. Press ACT once to return to the HOME screen.

Clearing the Glucose History

NOTE -

If there is data in the Monitor that you want to save, download the data using the Com-

Station and Guardian Solutions Software before clearing the history.

NOTE -

You only need to clear the Monitor glucose history prior to first-time use, between different users, or at the end of any training or demo sessions prior to first-time use. Glucose history data in the Monitor overwrites itself automatically, so you do not need to clear the history on a regular basis.

The Monitor glucose history should be cleared before first-time use. This is to make sure that the memory is free of unwanted information.

From the HOME screen:

1. Press the SEL button 7 times until the SETUP screen appears.

2. Press the ACT button once to get to the SETUP sub-screens.

12:00

SET

DAY

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Getting Started 27

3. Press the SEL button 7 times until the CLEAR sub-screen appears.

4. Press the ACT button once. The Monitor will beep, and the word NO will appear on the screen

blinking.

5. Use the Up or Down arrow button to choose between YES and NO. Select YES to clear the Monitor

memory.

6. With YES displayed on the screen, press the ACT button once. The Monitor will display YES with

CONFIRM blinking.

GLUCOSE HIST:

CLEAR

GLUCOSE HIST:

CLEAR

GLUCOSE HIST:

CONFIRM

YES

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28 Chapter 2

7. Press the ACT button again. The Monitor will beep or vibrate and the word CLEARING will appear for

a few seconds.

8. The Monitor will then go to the LANGUAGE screen. The memory will now be cleared. Press SEL to go

to the EXIT screen, followed by ACT to go back to the HOME screen.

9. If NO is selected, the Monitor memory will NOT be cleared, and the Monitor will go to the LANGUAGE

screen. Press SEL to go to the EXIT screen, followed by ACT to go back to the HOME screen.

CLEARING

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Getting Started 29

Setting the Glucose Unit

The Monitor gives you a choice of entering meter BG values and setting the low blood glucose and high blood glucose limits in either mg/dl or mmol/l.

From the HOME screen:

1. Press the SEL button 7 times until the SETUP screen appears.

2. Press the ACT button once to go to the SETUP sub-screens.

3. Press the SEL button 5 times until the UNIT sub-screen appears.

4. Press the ACT button once, and use the Up or Down arrow button to choose either mg/dl or mmol/l.

5. Press the ACT button again to save the chosen units, and the Monitor will go to the ID sub-screen.

Press SEL 3 times to go to EXIT, and press ACT one to go back to the HOME screen.

GLUCOSE

UNIT

mg/dl

GLUCOSE

UNIT

mg/dl

SET

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30 Chapter 2

Setting the Low Glucose Alert

The Monitor is designed to alert the user when the system finds glucose values at or above the set high glucose limit, or at or below the set low glucose limit. These alerts may be turned off if not needed or wanted. If an alert is triggered, you should confirm the glucose value with a home glucose meter before taking any action. Also, you should use a home blood glucose meter to confirm the symptoms of high and low blood glucose. (See Chapter 1: Introduction for a list of symptoms.)

The low glucose alert can be set from 40-100 mg/dl (2.2-5.5 mmol/l). Enter a glucose value within this range to set a low glucose alert. Typically , the number entered is above the value that causes you to have symptoms of low blood glucose. Confirm the alert limit with your doctor.

For this feature to work, you must select ON, a value, and CONFIRM to save the value in memory. Always treat low blood glucose per the advice of your doctor and the readings of your blood glucose meter.

From the HOME screen:

1. Press the SEL button 7 times until the SETUP screen appears.

2. Press the ACT button once to go to the SETUP sub-screens.

3. The LOW Limit sub-screen will automatically appear with the previously set low-glucose limit (or the

default value of 60 mg/dl (3.3 mmol/l) ) showing in the upper right hand of the display.

4. Press the ACT button and the following screen appears with ON (default setting) blinking:

LOW

LIMIT

GLUCOSE

mg/dl

LOW

LIMIT

GLUCOSE

SET

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Getting Started 31

5. Press the Up or Down arrow button to choose either ON or OFF or rEP (Repeat Function - See Next

Page). If you do not want to use this feature, choose OFF and the low glucose alert feature will be turned off.

6. Press the ACT button.

7. If ON is entered, the current value will begin blinking.

8. Use the Up or Down arrow button to choose the value you want to set a low glucose alert. Press the

ACT button to save the chosen value. The value 65 mg/dl (3.6 mmol/l) has been entered in this example.

NOTE -

Since it takes time for the Guardian RT to collect and measure glucose values, there is a

delay in triggering the alert. Ask your doctor which low glucose limit is right for you.

9. Press the ACT button to confirm the chosen value. The screen will go to the HIGH sub-screen. If you

would like, program the HIGH Limit as well. If not, press SEL 8 times to go to EXIT. Press ACT once to go back to the HOME screen.

10. If you do not want to use this feature, repeat steps 1-4, and then use the Up or Down arrow button

to select OFF and press the ACT button. A CONFIRM screen will be displayed. Press the ACT button once more to set, and the low glucose alert feature will be turned off.

LOW

LIMITGLUCOSE

SET

mg/dl

CONFIRM

mg/dl

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32 Chapter 2

11. To customize the time delay for a specific time period between recurrences of the LOW glucose

alert, repeat steps 1-4. Next, use the Up or Down arrow button to select rEP (blinking), and press the ACT button.

12. The previously set time interval (or 20 minutes default) will be blinking. Use the Up or Down arrow

button to select the desired interval, in 10-minute increments, from 20 minutes to 60 minutes (1 hour). Press the ACT button. The CONFIRM screen will be displayed. Press the ACT button to set.

NOTE -

Ask your doctor to which Repeat time interval is right for you.

NOTE -

If after setting a REPEAT interval you change either the REPEAT setting and/or the Low

Alert limit setting, the system will reset, and the Low Glucose Alert will be activated once more.

LOW

LIMIT

GLUCOSE

rEP

SET

CONFIRM

GLUCOSE

SET

00:20

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Getting Started 33

Setting the High Glucose Alert

The high glucose alert range is 105-400 mg/dl (5.8-22.2 mmol/l). Enter a glucose value within this range to set a high glucose alert. Typically, the number entered is below the value that causes you to have symptoms of high blood glucose. Confirm the alert limit with your doctor.

For this feature to work, you must select ON, a value, and CONFIRM to save the value in memory. Always treat high blood glucose per the advice of your doctor.

From the HOME Screen:

1. Press the SEL button 7 times until the SETUP screen appears.

2. Press the ACT button once to go to the SETUP sub-screens.

3. Press the SEL button once until the HIGH Limit sub-screen appears. The previously set high-glucose

limit (or the default value of 200 mg/dl (11.1 mmol/l)) will appear in the upper right hand of the display.

4. Press the ACT button and the following screen appears with ON (default setting) blinking:

5. Press the Up or Down arrow to choose either ON or OFF or rEP (Repeat). If you do not want to use

this feature, choose OFF and the high glucose alert feature will be turned off.

HIGH

LIMIT

GLUCOSE

200

mg/dl

HIGH

LIMIT

GLUCOSE

SET

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34 Chapter 2

6. If ON is activated, the default value will be blinking.

7. Use the Up or Down arrow button to choose the value you want to set a high glucose alert.

8. Press the ACT button to save the chosen value. The following screen will appear with CONFIRM

blinking. The value 240 mg/dl (13.3 mmol/l) has been entered in this example.

NOTE -

Since it takes time for the Guardian RT to collect and measure glucose values, there is a

delay in triggering the alert. Ask your doctor which glucose limit is right for you.

9. Press the ACT button to confirm the chosen value. The screen will go to the ALERT sub-screen. Press

SEL 7 times to go to EXIT. Press ACT once to go back to the HOME screen.

10. If you do not want to use this feature, repeat steps 1-4, and then use the Up or Down arrow button

to select OFF and press the ACT button. A CONFIRM screen will be displayed. Press the ACT button once more to set, and the high glucose alert feature will be turned off.

HIGH

LIMITGLUCOSE

SET

mg/dl

200

CONFIRM

240

mg/dl

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Getting Started 35

11. To customize the time delay for a specific time period between recurrences of the HIGH glucose

alert, repeat steps 1-4. Next, use the Up or Down arrow button to select rEP (blinking), and press the ACT button.

12. The previously set time interval (or 1 hour default) will be blinking. Use the Up or Down arrow to

select the desired interval, in 30-minute increments, from 60 minutes to 180 minutes (3 hours). Press the ACT button. The CONFIRM screen will be displayed. Press the ACT button to set.

NOTE -

Ask your doctor which Repeat time interval is right for you.

NOTE -

If after setting a REPEAT interval you change either the REPEAT setting and/or the High

Alert limit setting, the system will reset and the High Glucose Alert will be activated once more.

HIGH

LIMIT

GLUCOSE

rEP

SET

CONFIRM

GLUCOSE

SET

1:00

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36 Chapter 2

Setting the Alert Type

The Set Alert feature gives the choice of BEEP, VIBRATE, or BOTH whenever an alert is triggered. The default setting for the Monitor is the audible BEEP. Choose the Alert type as follow:

From the HOME screen:

1. Press the SEL button 7 times until the SETUP screen appears.

2. Press the ACT button once to get to the SETUP sub-screens.

3. Press the SEL button 2 times until the ALERT sub-screen appears.

4. Press the ACT button once, and the word BEEP (default setting) will appear blinking. Use the Up or

Down arrow button to choose BEEP, VIBRATE, or BOTH.

5. Press the ACT button again to save your choice in the Monitor memory. If the VIBRATE alert has

been chosen, the Monitor will vibrate briefly and go to the SET TIME and DATE screen.

ALERT

SET

VIBRATE

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Getting Started 37

6. If you choose the BEEP or BOTH alert, a number 2 (default) will appear blinking above the words

BEEP VOL. You can choose between three different beep volumes: 1 = Low, 2 = Medium, and 3 = High. Use the Up or Down arrow button to choose 1, 2, or 3. (While scrolling, corresponding beep tones will sound.)

7. Press the ACT button to save your choice. The Set Time and Date screen will appear. Press SEL 6

times to go to EXIT. Press ACT to go back to the HOME screen.

Entering the Transmitter ID

Each Transmitter is given a unique 7-digit identification number in the factory , from 0000001 to 9999999, which is the serial number shown on the Transmitter device label. This number (including leading zeros) must be entered into the Monitor before glucose data sent from the Transmitter can be received and stored in the Monitor. This will limit the Monitor to only receive data from the Transmitter with that ID number. If a different Transmitter is used, the new Transm itter ID must be entered.

From the HOME screen:

1. Press the SEL button 7 times until the SETUP screen appears.

2. Press the ACT button once to go to the SETUP sub-screens.

3. Press the SEL button 6 times until the ID sub-screen appears.

4. Press the ACT button, and a 0000000 number will appear with the first digit blinking. Use the Up or

Down arrow button to choose the first digit in your Transmitter ID number.

BEEP VOL

TRANS ID

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38 Chapter 2

5. Press the ACT button again to go to the second digit.

6. The second digit will now be blinking. Use the Up or Down arrow button to choose the second digit in

your Transmitter ID number.

7. Press the ACT button once again to go to the third digit.

8. Keep using the Up or Down arrow to choose numbers for each of the digits left. Then press the ACT

button to go to the next digit. The example below uses 7596.

NOTE -

If the ID number is less than 7 digits, make sure leading zeros are entered.

9. Press the ACT button after the 7th digit has been entered to save the ID in the Monitor. Press SEL

2 times to go to the EXIT screen, followed by ACT to go back to the HOME screen.

SET

0007596

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Getting Started 39

Inserting the Sensor

Before handling the Sensor, wash hands thoroughly. Choose a site with enough subcutaneous fat for Sensor insertion. The abdominal area and upper buttocks are the best and most common-used sites for insertion of the Glucose Sensor. See Figure 2.4 for all body areas where the Glucose Sensor can be inserted.

Figure 2.10

As a rule, AVOID the following areas:

➠ Frequently used injection or pump sites. (Never insert Sensor closer than 3 inches (7.62 cm) from

pump infusion site or manual injection site.)

➠ Belt or waistline ➠ Within 2-inch (5.08 cm) area around navel or less than 3 inches (7.62 cm) from pump infusion site

or manual injection site.)

➠ Site where clothing will rub or press against the Sensor ➠ Scarred or atrophied tissue ➠ Areas experiencing a lot of movement

NOTE -

Clean site with alcohol, making sure site is dry before inserting Sensor. Do NOT use skinprep solutions prior to insertion. However, I.V. Prep may be used after insertion and before applying a sterile dressing. Lift back of tape slightly to apply I.V. Prep.

CAUTION: Do not connect Sensor to Transmitter at this time.

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40 Chapter 2

1. Carefully open sterile Sensor pouch, and take out Sensor from package by holding base or tape. Do

not hold Sensor by introducer needle handle. Place the Sensor in the Sen-serter until it fits snugly.

2. Hold Sen-serter as shown:

3. Secure white tape of Sensor, and take off clear tape using counterclockwise motion.

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Getting Started 41

4. Place fingers on back of white tape, and push carrier down until it clicks in place.

5. As a safety measure, when the Sen-serter is in the loaded position you can set the lock at the top of

the device until you are ready to insert. a. To Lock: Rotate the white knobs 90o away from the arrows on the side of the Sen-serter.

b. To Unlock: Rotate the white knobs 90o so that they align with the arrows on the side of the

Sen-serter.

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42 Chapter 2

6. Take off needle guard from introducer needle.

NOTE -

While the use of gloves at this point is required for clinicians, it is optional for patients.

7. Rest Sen-serter legs against skin at 45-degree angle, placing two fingers of opposite hand on Sen-

serter legs to keep this angle.

NOTE -

Sensor may not penetrate skin if insertion angle is less than 45 degrees.

8. Press white button to insert Sensor, checking to see that Sensor is inserted and flush with skin

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Getting Started 43

9. While holding Sensor in place, gently slide Sen-serter away from Sensor. Do not twist, bend or lift

Sen-serter while taking it off Sensor.

10. Holding Sensor base, take off white paper from adhesive pad. Press adhesive against skin.

11. Hold Sensor with two fingers on base, and gently take out introducer needle at 45-degree angle.

➠ Do NOT rotate introducer needle when taking it out ➠ Throw away needle in sharps container ➠ Check site for redness, bleeding, irritation, pain, tenderness or swelling

NOTE -

The expected life of the Sensor is at least 24 hours and is good for up to 72 hours of use. Replace Sensor at 72 hours, or earlier in the event of a REPLACE SENSOR (C80) alarm. If these alarms are triggered, follow instructions in Chapter 4: Troubleshooting and Alarms.

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44 Chapter 2

Sensor Storage and Handling

➠ Store Sensors in refrigerator at +36° to +50°F (+2° to 10°C). Do not freeze. ➠ Before opening, allow individual Sensor package to reach room temperature and 5% to 95% relative

humidity to avoid condensation.

➠ Sensors taken out of refrigeration must be kept at or below room temperature, +50° to +75°F (+10°

to 24°C), and used within 1 week to ensure Sensor sensitivity.

➠ Throw away Sensor after “Use Before” expiration date on label, or if the package is damaged or the

seal broken.

➠ Do not use Sensor if High temperature-limit indicator is black (not clear).

Sen-serter Maintenance

➠ Occasionally clean Sen-serter with soapy water, using liquid detergent or other household soaps.

Allow to dry.

➠ Disinfect Sen-serter by wiping with 10% bleach solution or 70% isopropyl alcohol as needed. ➠ Always store Sen-serter in the released position to ensure peak product performance and life.

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Getting Started 45

Affixing the Transmitter

1. Find a comfortable, protected area on the abdomen (away from the belt-line) that is within Cable

reach of the Sensor. Clean the area with isopropyl alcohol and allow to dry.

2. Use the disposable Transmitter adhesive pad (MMT-7006) to affix the Transmitter to your body.

3. Take off the paper backing from the Transmitter side of the adhesive pad (side labeled “1”).

4. Stick the adhesive pad to the smooth, flat, unlabeled side of the Transmitter.

5. Take off the paper from the skin side of the adhesive pad (side labeled “2”). Press firmly to prepped

skin.

6. Transmitter should now be affixed to skin with serial number facing outward.

NOTE -

An adhesive remover, such as Detachol®, can be used to take off the adhesive pad, or any adhesive residue left on the skin after taking off the pad. Use a product tested for use on skin, and follow the product’s instructions.

CAUTION: Do not connect Sensor to Transmitter at this time. Do a SEARCH for the Transmitter first.

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46 Chapter 2

Searching for the Transmitter

The Search procedure starts communication so that the Monitor can receive and recognize the data signals from the Transmitter.

NOTE -

Before starting a SEARCH, make sure the Transmitter ID has been entered into the Monitor.

From the HOME screen:

1. Press the SEL button 5 times until the SEARCH screen appears.

2. Press the ACT button and the Monitor will beep or vibrate, and CONFIRM will be blinking on the screen.

3. Press the ACT button again to begin a SEARCH. The screen will display WAITING and a countdown

clock starting at 8 minutes and 00 seconds. The countdown will be in 10-second intervals. Connect Sensor to Transmitter at start of countdown. It may take up to 8 minutes to finish the SEARCH.

4. If you want to cancel the SEARCH, press SEL. The Monitor will beep or vibrate, and CONFIRM will be

blinking on the screen. Press ACT to confirm.

Caution: Do not press any button on the Monitor while doing a Search. This

interferes with the Search action.

8:00

WAIting

3:58 PM

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Getting Started 47

Connecting the Sensor to the Transmitter

NOTE -

To extend Transmitter battery life, do not leave Sensor or Test Plug connected to the Transmitter when system is not in use.

1. With the Monitor in SEARCH mode, hold the base of the Sensor

between the thumb and forefinger so that it doesn’t move. Hold the Transmitter connector in the other hand. Place the Sensor connector so that the two connectors are closely aligned. Push together to connect the Transmitter to the Sensor. You should hear a click when fully connected.(See Figure 2.5.)

Figure 2.11

The Monitor will search for signals sent by the Transmitter. If the Transmitter is not identified by the Monitor, an alarm code will appear. See Chapter 4: Troubleshooting and Alarms for detailed information on Alarm codes.

3. When the Transmitter is identified by the Monitor, the screen will briefly display SUCCESS. The INIT

screen will then appear.

4. Cover the Sensor site with a sterile/snug dressing, such as

IV3000®. (See Figure 2.6.)

Figure 2.12

NOTE -

If the Transmitter is unplugged from the Sensor, wait 20 seconds before reconnecting in order to ensure normal operation

SUCCESS

3:58

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48 Chapter 2

Sensor Initialization

After the Transmitter Search is done, the SUCCESS screen will be briefly displayed. The INIT screen will then appear. The system automatically initializes the Sensor before starting to record glucose data. Initialization takes about 120 minutes (2 hours). The Monitor, however, will count down from 140 minutes (2 hours and 20 minutes) toward 0 hours and 0 minutes, or until finished (whichever comes first), in one-minute intervals.

Sensor Calibration

When initialization is done, the system will alarm and the Enter BG screen to the right will be displayed. This screen shows that calibration is needed. A fingerstick glucose value must be entered into the Monitor to calibrate the Sensor. The Guardian RT will not record or display any glucose values, and the High and Low glucose alerts will not work until calibration is done. Calibration is needed to make sure the Guardian RT can turn the electronic signals from the Sensor into glucose values. Make sure to enter a BG value right after taking a fingerstick glucose reading. Calibration will happen within 10 to 15 minutes of the Meter BG entry.

NOTE -

Use the same blood glucose meter for all calibrations to ensure the accuracy of the calibrations.

NOTE -

If an incorrect blood glucose value is entered, this value can be overwritten within 10-15

minutes of input.

1. Press the SEL button followed by ACT to clear the alarm.

2. Press the SEL button 2 times. When the METER BG screen appears, the last glucose value (mg/dl or

mmol/l) entered will be displayed. (Dashes will appear the first time since no entry has been made.)

12:00

INIT

2:20

12:00

ENTER BG

C 78



---

mg/dl

METER BG

GLUCOSE

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Getting Started 49

3. Press the ACT button, and the glucose value (dashes) will blink. Use the Up or Down arrow buttons

to scroll through the values until the right one is displayed in increments of 1 mg/dl or 0.1 mmol/l. Holding down either button will scroll faster through the list of values. The METER BG feature lets you enter values from 20 to 600 mg/dl (1.1 to 33.1 mmol/l). However, only values between 40-400 mg/dl (2.2-22.2 mmol/l) are used for calibration.

NOTE -

The METER BG screen will display the last value programmed. But when ACT is pressed, the scrolling will start at “---” and the screen will read ENTER BG. If the Up or Down arrow is pressed, the next value scrolled to is 100 mg/dl (5.5 mmol/l). If ACT is pressed when “---” is displayed, no value is entered.

4. Press the ACT button to save the right value. The Monitor will run a calibration and sensitivity check

using the Meter BG value entered and the Sensor value that corresponds in time. Calibration occurs 10 to 15 minutes from the time of entering the fingerstick glucose reading.

5. The HOME screen will appear.

NOTE -

The Monitor will not use values between 20-39 mg/dl (1.1-2.2 mmol/l) and 401-600 mg/dl (22.2-33.3 mmol/l) for calibration. These values will be displayed and saved for informational purposes only. BE SURE TO TREAT LOW AND HIGH CONDITIONS PER THE ADVICE OF YOUR DOCTOR. Also, when a value in the 40-400 mg/dl (2.2-22.2 mmol/l) range is displayed, ENTER BG will appear below it. When a value in the 20-39 mg/dl (1.1-2.2 mmol/l) or 401-600 mg/dl (22.2-33.3 mmol/l) ranges is displayed, NO CAL will appear below it.

NOTE -

Every time you change your Sensor, a fingerstick glucose reading must be entered into the METER BG screen. A fingerstick glucose reading should be entered every 6 hours, however, a minimum of one meter reading must be entered every 12 hours. More frequent daily readings will optimize the accuracy of the Sensor glucose readings. If you have not entered a reading into the METER BG screen in 12 hours, a C78 (ENTER BG) alarm will be triggered. This alarm is also triggered if a calibration has not been done in the last 8 hours since the first calibration.

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50 Chapter 2

Calibration Pending

If a BG value has been recently entered, but the Up arrow is pressed from the HOME screen within 15 minutes of the entry, not giving the Sensor enough time to calibrate, the screen below will be displayed. The example 90 mg/dl (5.0 mmol/l) is the recently entered Meter BG value.

No Sync

If the Sensor is not in INIT, (Initialize mode) and still working, and the Guardian RT is not synchronized, then the screen below will be displayed. This means that the Monitor is not getting Sensor data from the Transmitter at this point in time.

PENDING

mg/dl

GLUCOSE

No SYNC

12:00

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Getting Started 51

Replacing the Glucose Sensor

If the word REPLACE is displayed on the screen along with a time that is not the current time (i.e., the time displayed is a future time), the Sensor must be changed before the next calibration is due. The time displayed is the end of Sensor life. If REPLACE and the current time are displayed on the screen, then the Sensor is not working and the system is no longer sending Sensor glucose values. Change out the Sensor immediately to continue using the Guardian RT system.

Removing the Sensor

➠ Remove dressing ➠ Pinch snap arms on sides of Glucose Sensor, and gently disconnect Transmitter Sensor Connector

from Glucose Sensor

➠ Slowly remove Glucose Sensor by pulling it parallel to the skin ➠ Throw away Sensor in Sharps or other biohazard container

NOTE -

To extend Transmitter battery life, do not leave Glucose Sensor connected to the Transmitter when system is not in use.

REPLACE

12:00

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52 Chapter 2

Page 59

Chapter 3

Routine Operation

This chapter explains how to use the Main Screens of the Guardian RT. From the HOME screen, press the

SEL button to go to each of these operating screens. Press ACT to enter these screens.

NOTE -

Pressing the SEL button from the SETUP screen will take you back to the HOME screen.

Glucose History

The glucose history will display the last 8 hours of glucose values. The oldest value will be displayed if the Up arrow button is pressed, or the newest (most recent) if the Down arrow button is pressed, for a total of 96 available entries. The history can be viewed in 5- or 30-minute increments. From the HOME Screen:

1. Press the SEL button once until the GLUCOSE HISTORY screen appears. In the example below, the

most current glucose value is 108 mg/dl (6.0 mmol/l).

NOTE -

The word NOW on the screen above refers to the current Sensor glucose value.

NOW

GLUCOSE

11:57

108

mg/dl

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54 Chapter 3

2. Scroll through the history by using the Up arrow button to go from oldest to newest glucose value in 5-minute

increments. Press the Down arrow button to go from newest to oldest glucose value in 5-minute increments. In the example below, the glucose value was 112 mg/dl (6.22 mmol/l), 5 hours and 25 minutes ago.

3. If the ACT button is pressed, the scrolling display will switch from 5- to 30-minute increments, and an

asterisk ( ) will be displayed next to the time increment. If you now press the Up arrow button, the history will go from oldest to newest glucose value in 30-minute increments. If you press the Down arrow button, the history will go from newest to oldest glucose value in 30-minute increments. In the example below, the glucose value was 96 mg/dl (5.33 mmol/l) 4 hours and 35 minutes ago. Press the ACT button to go back to scrolling in 5-minute increments. The asterisk will no longer be displayed.

4. If the glucose value is lower or higher than operational range of 40-400 mg/dl (2.2 -22.2 mmol/l),

the screen will display LO or HI where the glucose value is normally found. See example below.

NOTE -

When there is no calibration for the Sensor value, NO CAL* will be displayed on the bottom

of the screen in place of NOW. In these cases,

“---”

will be displayed for the glucose value. When the Sensor value is unstable, NOISE* will be displayed on the screen. And when the Sensor value is unavailable due to bad or no telemetry, MISSED* will be displayed on the screen.

-5h 25M

GLUCOSE

HIST:

11:57

112

mg/dl

-4H 35M

GLUCOSE

HIST:

11:57

mg/dl

-5H 25M

GLUCOSE HIST:

mg/dl

11:57

Page 61

Routine Operation 55

Entering Meter BG for Calibration

In order for the electronic signals from the Sensor to be converted into glucose values, Meter BG (Blood Glucose) readings must be entered into the Guardian RT for the purpose of calibration. See Chapter 2: Getting Started, Sensor Calibration.

From the HOME screen:

1. Press the SEL button 2 times and the METER BG screen will appear. In the example below, the last

entered meter blood glucose value was 95 mg/dl (5.3 mmol/l). This value will thus appear on the display. (If no BG reading was entered before, dashes (“- - -”) will appear on the screen.)

2. Press the ACT button, and the number display will go to dashes. Enter the desired meter blood

glucose value, in increments of 1 mg/dl (0.1 mmol/l), by using the UP or Down arrow button. Remember, the number value will start at 100 mg/dl. See Chapter 2: Getting Started, Sensor

Calibration.

NOTE -

If you scroll below 40 mg/dl (2.22 mmol/l) or above 400 mg/dl (22.2 mmol/l) the screen will

display “NO CAL.” The value entered will be stored but not used for calibration.

3. Press the ACT button to set the value, and the display will return to the HOME screen.

MEter BG

mg/dl

12:00

ENter BG

mg/dl

---

SET

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56 Chapter 3

BG Due

One useful feature of the Guardian RT is the BG DUE screen. This screen lets you know when to enter the next needed blood glucose (BG) value into the Guardian RT to go on with calibration.

From the HOME screen:

1. Press the Up arrow button once. If an initial Sensor calibration has already been performed, the

screen will display when the next BG entry is due. Pressing SEL or ACT once, or the Up arrow 2 times, will return you to the HOME screen. In the example below, the last calibration was done at 12:45 A.M. Therefore, the next BG value is due before 12:45 P.M. because the last BG entered was 12 hours before.

Depending on the condition and calibration status of the Sensor, there are four other screens that may be displayed, instead of BG DUE, by pressing the Up arrow once from the HOME screen. These screens are: ENTER BG, PENDING, NO SYNC, and REPLACE.

NOTE -

If calibration is pending, do not turn off the Monitor. Otherwise, you will have to enter a new

Meter BG value.

BG DUE

12:45

Page 63

Routine Operation 57

Enter BG

If no calibration has been done, and no calibration is pending, the screen below will be displayed if the Up arrow is pressed from the HOME screen.

Calibration Pending

If a BG value has been recently entered, but the Up arrow is pressed within 15 minutes of the entry, not giving the Sensor enough time to calibrate, the screen below will be displayed. The example 90 mg/dl (5.0 mmol/l) is the recently entered Meter BG value.

ENTEr bg

12:45

PENDING

mg/dl

GLUCOSE

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58 Chapter 3

No Sync

If the Sensor is not in INIT (Initialize mode), and still working, and the Guardian RT is not synchronized, then the screen below will be displayed. This means that the Monitor is not getting Sensor data from the Transmitter at this point in time.

Replacing the Glucose Sensor

No SYNC

12:00

REPLACE

12:00

Page 65

Routine Operation 59

Events

The EVENT screens are used to record information that might affect glucose values. Events are stored but they cannot be reviewed on the Monitor display (except previously entered values). Event markers and related values can be downloaded, along with the glucose Sensor history, to the Guardian Solutions Software using the Com-Station cradle. Event information is helpful in evaluating glucose trends and patterns displayed in the software reports. There are four types of events that can be recorded into the Monitor:

‡ Insulin ‡ Carb Amount ‡ Exercise ‡ Other

From the HOME screen:

1. Press the SEL button 3 times, and the EVENTS screen will appear.

2. From the EVENTS screen, press the ACT button. The screen will display INSULIN, and it will be

blinking. Use the Up arrow to move between the following Event options:

‡ Insulin ‡ Carb Amount ‡ Exercise ‡ Other

EVENTS

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60 Chapter 3

Units of Insulin Taken

From the HOME screen:

1. Press the SEL button 3 times, and the EVENTS screen will appear.

2. Press the ACT button once, and the screen will display SET and INSULIN will be blinking. (Dashes will

be displayed if no insulin amount was entered before.)

NOTE -

If you are an insulin pump user, the dose refers to your bolus, not basal insulin. If your bolus amounts are in the hundredth of a unit (2 places after the decimal point), round to the nearest tenth of a unit (one place after the decimal point) or whole number of units.

3. Press the ACT button.

4. Press the Up or Down arrow button to enter units of insulin taken, from 0.1 to 99 units.

5. Press the ACT button to confirm, and a blinking CARB AMT screen will appear.

INSULIN

7.0

SET

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Routine Operation 61

Carbohydrate Amount

After an Insulin dose has been entered and the ACT button pressed, the screen will display SET, and CARB AMT will be blinking. (Dashes will be displayed if no carb amount was entered before.) If you do not want to enter a carbohydrate amount, press SEL until the HOME screen appears. Otherwise, follow these steps.

1. Press the ACT button.

2. Press the Up or Down arrow button to enter the amount of carbohydrate eaten. (Example: One

baked (6 ounce) potato is 30 grams of carbohydrate.) The unit range is from 1 to 300. Enter the Carb Amount in units, grams, or exchanges. If you do not know how to figure out amount of carbohydrate eaten, ask your doctor to learn how.

3. Press the ACT button again to save the carbohydrate amount in the Monitor memory. Return to the

HOME screen.

Duration of Exercise

From the HOME screen:

1. Press the SEL button 3 times, and the EVENTS screen will appear.

2. Press the ACT button once. The screen will display SET, and INSULIN will be blinking.

3. Use the Up or Down arrow button to choose the exercise Event option. The screen will display SET,

and EXERCISE will be blinking. (Dashes will be displayed if no exercise amount was entered before.)

CARB AMT

SET

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62 Chapter 3

4. Press the ACT button. Use the Up or Down arrow buttons to enter how long you have exercised. You

can enter Exercise in 10-minute increments up to 4 hours.

5. Press the ACT button to save the exercise length and go back to the HOME screen.

Other Events

Any other important events, such as illness, menstrual cycle, etc., can be entered using the OTHER screen.

From the HOME screen:

1. Press the SEL button 3 times, and the EVENTS screen will appear.

2. Press the ACT button once. The screen will display SET with “INSULIN” blinking.

3. Press the Down arrow, and the screen will display SET, and “OTHER” will be blinking.

4. Press the ACT button again to enter the OTHER event and go back to the HOME screen.

NOTE -

No values are associated with OTHER events. Track the type of event manually in your

logbook.

0:30

EXERCISE

SET

OTHER

Page 69

Routine Operation 63

Glucose Alarm History

The glucose alarm history will display the last 20 high and low glucose alarms received.

From the HOME Screen:

1. Press the SEL button 4 times until the GLUCOSE ALARMS screen appears.

2. Press the ACT button to view the saved alarms.

3. If there are no alarms in the history, the following screen will appear:

4. If there are alarms in the history, the newest one will be displayed first. The alarm will be displayed

with the time and date they were triggered and the corresponding value.

5. In the example below, an alarm was triggered at 13:04 (1:04 PM) on August 3, 2002 when the glucose

value reached 140 mg/dl (7.77 mmol/l). This value is at or above the High glucose limit setting.

ALARMS

GLUCOSE

NONE

- -: - -

140

13:04

03AUG02

GLUCOSE

mg/dl

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64 Chapter 3

6. If the glucose value was outside the “operational range” of 40-400 mg/dl (2.2 -22.2 mmol/l), then

the Guardian RT will display either of these two screens:

7. Use the Up or Down arrow button to go through the rest of the Glucose Alarm History. Pressing the

DOWN arrow will display the previous (next-most recent) alarm. Pressing the UP arrow will display the oldest alarm. Press SEL to return to the HOME screen.

13:04

GLUCOSE

03AUG02

13:04

GLUCOSE

03AUG02

Page 71

Routine Operation 65

The Search procedure start synchronized communication between the Monitor and the Transmitter. The Search procedure is explained in detail in Chapter 2: Getting Started, Searching for the Transmitter. Please refer to that section for more information.

Signals

The SIGNALS screen is useful to make sure the ISIG (Input Signal, i.e., Sensor signal) readings are in the

correct range. Reviewing the Signal readings is valuable for reporting Signals within an acceptable range and when doing the Test Plug Procedure (See Chapter 4: Troubleshooting and Alarms). This procedure lets you know if the Monitor, Transmitter or Sensor are working properly.

From the TIME AND ALARM Screen:

1. Press the SEL button 6 times until the SIGNALS screen appears. Press the ACT button to view the

ISIG. Press the ACT button once more and the SETUP screen will be displayed.

2. If the Up or Down arrow button is pressed from the ISIG screen, the VCTR (Sensor voltage) screen is

displayed. This screen is for diagnostic purposes only and not for everyday use.

NOTE -

When in the INIT (Initialization) mode, do not go to the signals screen until the Monitor has

counted down to between 133 and 130.

Signals

GLUCOSE

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66 Chapter 3

NOTE -

While unlikely, moisture may enter the Guardian RT Transmitter connector during normal use. This may lead to erratic ISIG values above 200 nA. Stop Sensor use if problems with moisture are suspected. Remove the Transmitter from the skin surface and allow to air dry for 3-4 hours. (More or less drying time may be needed, depending on the air temperature and humidity.) Once dry, perform the Test Plug Procedure. If the ISIG values are in the range of 24-29 nA, then the Transmitter is working correctly.

The Snooze Option

The Guardian RT has a Snooze option that works with the HIGH alert feature. This option can be turned on during a specific period of time when you are expecting your glucose level to rise above the set HIGH limit (e.g., after eating a heavy meal). It can also be set if you do not want the HIGH alert to interrupt you during a given time interval (e.g., during a business meeting). The Snooze option will thus deactivate the HIGH alert for a specified period, from 1 to 12 hours.

In order to get to, and set, this feature, the Glucose HIGH limit setting must be ON. At the end of the set SNOOZE time period, the high glucose alarm feature will be turned on once more. You can view the SNOOZE screen to see how much of the set SNOOZE time is remaining. To turn the SNOOZE feature OFF at any time, access the SNOOZE screen, select --:-- and press the ACT button.

From the HOME screen:

1. Press the Up arrow 2 times to reach the SNOOZE screen.

2. Press the ACT button to display the time interval (blinking dashes).

3. Use the Up or Down arrows to choose the desired interval. Press the ACT button to set and go back

to the HOME screen.

4. The HOME screen will now display “S” in the upper right corner.

NOTE -

Ask your doctor if the Snooze option is right for you, and if so, what your personal Snooze

setting should be.

Snooze

SET

--:--

Page 73

Chapter 4

Troubleshooting and Alarms

This chapter lists the Monitor alarms and how to troubleshoot and respond to them to keep the system working smoothly. If an alarm is triggered, the Monitor will beep, vibrate, or do both, depending on the Alert setting. All alarms are cleared by pressing the SEL button, followed by the ACT button. If an alarm is not cleared within 10 minutes, a continuous tone will sound.

Alarms with the letter “F” on the display are system errors. Before clearing these types of alarms, U.S. and Canadian customers, please contact the Product Help Line at 800-MINIMED (800-646-4633) or 818-576-5555. All other international customers please contact your local sales office.

If more than one alarm has been triggered, the alarms will be shown in order on the display, starting with the oldest. The alarm type and when it was triggered is stored in the Monitor memory for later download to the Guardian Solutions Software.

NOTE -

Always take care of alarms right away. The first button press after an alarm is triggered turns on the display backlight. The backlight will stay on for about 10 to 20 seconds after the last button press.

NOTE -

A calibration must be done after taking care of certain alarms by entering a new METER BG value. No Monitor glucose values will be reported after these alarms are triggered until a successful calibration is done.

NOTE -

If a key is pressed and held down at the same time that an alarm is triggered, the alarm will not be displayed until the key is released.

CAUTION: An audible alarm may not awaken you if you are a heavy sleeper, or if

the sleeping environment has a significant amount of background noise. If there is a chance of not being awakened by the BEEP alert mode, then you should either use the VIBRATE or the BOTH mode. You should confirm that the alarm volume will be adequate to awaken you if an alarm is triggered during sleep.

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68 Chapter 4

List of Alarms

No ID

Error Message: C52/NO ID (Missing Transmitter ID)

Cause: A Transmitter ID has not been entered in the Monitor. Action: Press the SEL button and then the ACT button to clear the alarm. Enter the Transmitter ID (serial

number) into the Monitor’ s TRANS ID setup screen. See Chapter 2: Getting Started.

NO ID

12:00



C52

Page 75

Troubleshooting and Alarms 69

High

NOTE -

If the alert pattern is set on beep, a series of ascending tones will be heard. This tone is unique to the HIGH alert. If the alert type is set on vibrate, vibrations do not vary for different alarms.

NOTE -

In the screen above, 250 mg/dl is being used as an example.

Error Message: HIGH (High Glucose Alarm)

Cause: Glucose value is higher than or equal to the high glucose limit. Action:

5. Press the SEL button and then the ACT button to clear the alarm. The alarm will turn off and the

HOME screen will reappear. The alarm will repeat about every hour (or longer if the Repeat interval has been customized) until the condition has been corrected.

6. Take a blood glucose meter reading. If the value indicates a high blood glucose level, treat per your

doctor’s instructions and enter the value into the Monitor for calibration.

7. Even if the blood glucose value does not confirm the alarm, enter the value into the Monitor for

calibration.

HIGH

12:00



GLUCOSE

mg/dl

250

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70 Chapter 4

Low

NOTE -

If the alert pattern is set on beep, a series of descending tones will be heard. This tone is unique to the LOW alert. If the alert type is set on vibrate, there is no differentiation between the vibrations for the different alarms.

NOTE -

In the screen above, 60 mg/dl is being used as an example.

Error Message: LOW (Low Glucose Alarm)

Cause: Glucose value is lower than or equal to the low glucose limit set. Action:

1. Press the SEL button and then the ACT button to clear the alarm. The alarm will turn off and the

HOME screen will reappear. The alarm will repeat about every 20 minutes (or longer if the Repeat interval has been customized) until the condition has been corrected.

2. Take a blood glucose meter reading. If the value indicates low blood glucose level, treat per your

doctor’s instructions and enter the value into the Monitor for calibration.

3. Even if the blood glucose reading does not confirm the alarm, enter the value into the Monitor for

calibration.

LOW

12:00



mg/dl

GLUCOSE

Page 77

Troubleshooting and Alarms 71

Check Sensor

Error Message: C54/CHECK

Cause: The Monitor picked up a Sensor current that is outside the operating range or is unstable. Action:

1. Press the SEL button and then the ACT button to clear the alarm. The alarm will turn off, and the

HOME screen will reappear. The alarm will repeat periodically until the condition is corrected.

2. Make sure the insertion site appears normal and the Sensor is still connected. DO NOT REMOVE

CONNECTOR.

3. If the alarm is triggered two or more times, take out the Sensor. Before putting in a new Sensor, do

the Test Plug procedure at the end of this chapter to check system function.

4. If the Transmitter is not working correctly, a new Transmitter must be used. If it is working

correctly, put in a new Sensor. Run initialization and calibration. See Chapter 2: Getting Started.

check

12:00



C54

GLUCOSE SENSOR

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72 Chapter 4

Low Batt

Error Message: LOW BATT (Low Batteries)

Cause: The voltage of the AAA batteries in the Monitor is low. Action: Press the SEL button and then the ACT button to take care of the alarm. When this alarm is first

triggered, the batteries have about eight hours of normal operating life left. The time of the first alarm is recorded into the Monitor memory. The Battery icon will be displayed on the HOME screen.

1. Turn Off the Monitor.

2. Change the batteries. See Chapter 2: Getting Started.

NOTE -

Make sure to put in new batteries within 10 minutes of taking out the old ones to avoid automatic resetting of date and time. This will also avoid the triggering of a Replace Sensor alarm.

3. Do a manual Search procedure: a. From the HOME Screen, press the SEL button 5 times until the SEARCH screen appears. b. Press the ACT button and the Monitor will beep or vibrate. CONFIRM will be blinking on the

screen.

c. Press the ACT button again to begin a SEARCH. The screen will display SEARCH and the number 8

(minutes). A countdown will begin. It may take up to 8 minutes to finish the SEARCH.

NOTE -

Frequent use of the backlight and having the alert type on “vibrate” will use up batteries

quicker.

12:00



LOW BATT

Page 79

Troubleshooting and Alarms 73

Off/No Power

Error Message: OFF/NO POWER (Replace Batteries)

Cause: There is less than one (1) hour of battery life left. The Monitor will turn off. Action:

1. Press the SEL button and then the ACT button to CLEAR the alarm.

2. CHANGE THE BATTERIES RIGHT AWAY TO AVOID LOSS OF DATA STORED IN MEMORY! Follow steps

in Chapter 2: Getting Started.

3. Perform the manual Search procedure:

a. From the HOME Screen, press the SEL button 5 times until the SEARCH screen appears. b. Press the ACT button and the Monitor will beep or vibrate. CONFIRM will be blinking on the

screen.

c. Press the ACT button again to begin a SEARCH. The screen will display SEARCH and the number 8

(minutes). A countdown will begin. It may take up to 8 minutes to finish the SEARCH.

12:00



NO POWER

OFF

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74 Chapter 4

Service C60/61

Error Message: C60/SERVICE (Transmitter Battery Low/End of Battery Life)

Cause: The Transmitter battery is low when C60 appears. The C60 service alarm will repeat each day

around 12:00 noon. Service C61 means that the Transmitter battery is used up.

Action: Press the SEL button and then the ACT button to clear the alarm. The battery cannot be changed in the

Transmitter . The battery life is about one year. Change out the Transmitter as soon as possible. Take off the Sensor, and insert a new Sensor to connect to the new T ransmitter. After the T ransmitter is changed, the Monitor must be reprogrammed with the new Transmitter ID number . See Chapter 2: Getting

Started.

Re Init

Error Message: C62/RE INIT (Re-Initialize Sensor)

Cause: The Monitor did not get the needed setup information from the Transmitter. Action: Press the SEL button and then the ACT button to clear the alarm. Disconnect the Sensor from the

Transmitter . Perform Search, reconnect Sensor , and following Initialization, enter blood glucose calibration. See Chapter 2: Getting Started.

NOTE -

If this alarm is triggered repeatedly, change out Sensor and do Initialization process once more.

SERvice

12:00



C60

re init

12:00



C62

Page 81

Troubleshooting and Alarms 75

No Sync

Error Message: C76/NO SYNC (Loss of Communication)

Cause: The Monitor and Transmitter are out of synchronization. As a result, the Monitor is unable to get

data from Transmitter. The search for the Transmitter has failed, or communication has been lost.

Action:

1. Press the SEL button and then the ACT button to clear alarm. If Transmitter Search is not done, the

alarm will repeat every 20 minutes.

2. Make sure that the Transmitter ID entered correctly (including leading zeros). If it is, do a manual

SEARCH procedure:

a. From the HOME Screen, press the SEL button 5 times until the SEARCH screen appears. b. Press the ACT button and the Monitor will beep or vibrate. CONFIRM will be blinking on the

screen.

c. Press the ACT button again to start a SEARCH. The screen will display SEARCH and the number 8.

A countdown will begin. It may take up to 8 minutes to finish the SEARCH.

3. If not correct, reenter the Transmitter ID number and do the Sensor Initialization procedure. See

Chapter 2: Getting Started.

4. Reposition the Monitor and Transmitter within 5-10 inches (12.7-25.4 cm) of each other and retry

the SEARCH procedure.

5. Is a cell phone or another RF transmitter working nearby? If so, move further away, and retry the

manual SEARCH procedure.

6. Wireless transmission between the Monitor and the Transmitter within the six-feet operating range

may be interrupted due to Transmitter Cable orientation. Move the Monitor closer to the Transmitter or to another position and retry the SEARCH procedure.

NO sync

12:00



C76

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76 Chapter 4

7. If alarm continues, U.S. and Canadian customers please contact the Product Help Line at 800-MINIMED

(800-646-4633) or 818-576-5555. All other international customers please contact your local sales office.

Cal Err

Error Message: CAL ERR (Calibration Error)

Cause: Calibration cannot be done successfully due to Monitor and Transmitter not communicating,

Meter BG outside expected range from Sensor reading, or Monitor was turned off for more than 2 hours.

Action:

1. Press the SEL button and then the ACT button to clear the alarm. The alarm will turn off, and the

HOME screen will appear. An alarm to recalibrate will repeat until a new calibration is done.

2. Check to make sure that the antenna icon is displayed. If it is not displayed, the communication link

between the Transmitter and the Monitor has not been set. Restore communication between the Transmitter and the Monitor. Make sure the Monitor and Transmitter are within 6 feet (2 meters) of each other.

3. Take fingerstick reading and enter meter BG value, between 40-400 mg/dl (2.2-22.2 mmol/l), for

calibration.

CAL ERR

12:00



Page 83

Troubleshooting and Alarms 77

Key Held

Error Message: C77/KEY HELD

Cause: A Monitor key has been pressed and held for more than 3 minutes. Action: Press the SEL button and then the ACT button to clear the alarm.

Enter BG

Error Message: C78/ENTER BG (Enter Calibration Value)

Cause: Calibration is needed. No new glucose values will be recorded until calibration is done.

Calibration value must be between 40-400 mg/dl (2.22-22.2 mmol/l). This alarm is triggered if calibration has not been done in the last 12 hours or following a CAL ERR alarm, or if a calibration has not been done in the last 8 hours since the first calibration.

Action: Press the SEL button and then the ACT button to clear the alarm. Take a fingerstick reading using a

meter. Press the SEL button until the METER BG screen appears. Press the ACT button, and the dashes “-

--” will blink. Press the Up or Down arrow button to scroll through the values until meter value is displayed. Press the ACT button to confirm. Until calibration is done, this alarm will repeat hourly.

Key HELD

12:00



C77

ENTER BG

12:00



C78

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78 Chapter 4

Set Time

Error Message: C79/SET TIME (Reset Date and Time in Monitor)

Cause: The internal clock has cleared. Most likely the batteries were taken out and not placed back for

more than 10 minutes, and the clock does not have the right time.

Action: Press the SEL button and then the ACT button to take care of the alarm. Reprogram your Monitor, and

change Sensor, if prompted, following the instructions in Chapter 2: Getting Started.

SET TIME

12:00



C79

Page 85

Troubleshooting and Alarms 79

Replace Sensor

Error Message: C80/REPLACE (Change Sensor/End of Sensor Life)

Cause: The maximum expected life of the Sensor has been reached. In other words, either the Monitor

has seen a problem with the Sensor, triggering two calibration alarms, one after the other, or 72 hours have passed since the Sensor was first put in and initialized. This alarm will repeat every 20 minutes until the Sensor is changed and initialized.

Action:

1. Press the SEL and then the ACT button to turn off the alarm.

2. Turn the Monitor Off.

3. Turn the Monitor On.

4. Remove the Sensor, and insert a new Sensor. Follow the Inserting the Sensor section in Chapter 2:

Getting Started. Initialize the Sensor by following the Sensor Initialization section also in Chapter 2.

NOTE -

If after changing the Sensor, but before doing the initialization, the alarm repeats, turn off

the alarm and go on with initialization.

GLUCOSE



REPLACE

SENSOR

12:00

C80

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80 Chapter 4

System Alarms

These alarms are triggered when a diagnostic test finds an error in the Monitor. If an alarm code has an “F” followed by two numbers (example shown below), do the following procedure:

1. Write down the alarm code.

2. Download data into a personal computer right away (using the Com-Station and Guardian Solutions

Software) to help with troubleshooting the device.

3. To report the alarm, U.S. and Canadian customers please contact the Product Help Line at 800-MINIMED

(800-646-4633) or 818-576-5555. All other international customers please contact your local sales office.

4. Clear the alarm by pressing the SEL button and the ACT button. The Monitor programming will

change to factory settings, except for glucose history data. All other information needs to be reprogrammed after speaking with the Product Help Line.

Service

12:00



F##

Page 87

Troubleshooting and Alarms 81

Test Plug Procedure

If you come across an operating problem, the Test Plug gives information that can let you know if a Sensor, Monitor or Transmitter is working correctly. The Test Plug sends a constant electronic signal to the Monitor. This data can be read on the Monitor Signals screen. The normal signal range is about 24-29 nA (nanoamperes).

1. Disconnect the Sensor from the Transmitter’s Sensor connector.

2. Press the SEL button until the SEARCH screen appears, and start the search for the Transmitter. See

Chapter 2: Getting Started.

3. Connect the Sensor Connector end of the Transmitter to the Transmitter Connector end of the Test

plug (see Figure 4.1). Press the parts together until the snap arms on the Cable Connector come together with a click.

Figure 4.1

If the Monitor recognizes the Transmitter, the Monitor will enter the Initialization mode. The Monitor will display INIT and 2:20 h.

5. The Monitor will count the minutes down from 2:20 h. Data is first sent in the 2:13 to 2:10 h. To

check the correct ISIG values (ISIG stands for Input Signal, which is the Sensor current) you must wait for data to be first sent. Let the Monitor reach this range in time; it will take between seven to ten minutes. This wait period ensures that the reading from the Transmitter is stable.

Sensor Connector

Transmitter Connector

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82 Chapter 4

6. When the Monitor displays between 2:13 and 2:10 h, go to the SIGNALS screen (From the HOME

screen, press SEL 6 times and then press ACT) to view the ISIG.

NOTE -

Do not go to the signals screen until the Monitor has counted down to between 2:13 and 2:10 h.

7. If the ISIG value is between 24 and 29 nA, and the Initialization screen shows 2:00 h or less, the

Transmitter and Monitor are working properly. Change the Sensor. Initialize and calibrate the new Sensor. Refer to Chapter 2: Getting Started.

NOTE -

If you miss the first transmission of data and the second transmission has been sent, the ISIG reading will typically be above 29 to 34 nA and can go very high. This value should be ignored. All following transmissions will return to the 24-to-29 nA range.

8. If the ISIG value is outside the range of 24 to 29 nA, the Transmitter, Monitor, or both, may have a

problem. U.S. and Canadian customers, please contact the Product Help Line at 800-MINIMED (800-646-4633) or 818-576-5555. All other international customers please contact your local sales office.

NOTE -

To extend the operational life of the Transmitter battery, do not leave the Test Plug connected to the Transmitter when not in use.

Signals

GLUCOSE

SENSOR

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Performance Characteristics 83

Chapter 5

Performance Characteristics

NOTE -

Users should have the information in this chapter reviewed by their healthcare provider.

The Medtronic MiniMed Guardian RT uses a glucose Sensor to continuously monitor your glucose levels. The Guardian RT Sensor is “calibrated” using your home blood glucose meter. Once calibrated, the Guardian RT reports glucose values every 5 minutes. These values were compared to reference laboratory blood glucose measurements to check the Guardian RT’s performance characteristics in a

clinical study1. Although presentations to characterize performance of the Guardian RT are given below, there is no

commonly accepted statistical approach for capturing the performance of continuous glucose monitors such as the Guardian RT. Performance may be best characterized by viewing graphs called time-elapsed plots. In these plots, the values from Guardian RT for one subject over time are overlaid with values at the same time from the glucose reference method. Three representative time-elapsed plots of Sensors that exhibited excellent performance, average performance and poor performance are shown on pp. 9597 (Figures 5.3-5.5).

Medtronic MiniMed, A Frequent Sample Accuracy Evaluation of the Medtronic MiniMed T elemetered Glucose Monitoring System

II (TGMS II) in Subjects with Type 1 Diabetes Mellitus, August 2004.

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84 Chapter 5

Performance Results

The performance of the Guardian RT was evaluated in a clinical study. Guardian RT results were compared to plasma glucose values from a reference method, the YSI 2300 STAT PlusTM glucose analyzer (referred to as YSI). Sixteen subjects with Type I diabetes participated in a single-site in-clinic study. Subjects ranged in age from 18 to 65 years old. Each subject wore 2 Guardian RT systems simultaneously. One Guardian system was calibrated an average of 3.5 times per day, and the other was calibrated approximately 5 times per day using the BD LogicTM meter. YSI measurements were taken every thirty minutes.

Users and their healthcare providers should consider that performance in this study may be idealized, and that performance may be worse when the Guardian RT is used in a less-controlled home setting. For example:

‡ The mean Hemoglobin A1c among the 16 participants was 8.2%. As hemoglobin A1c levels rise,

conditions often occur which are most challenging to test systems measuring glucose in interstitial fluid, i.e., higher glucose levels, more rapid changes in glucose concentrations, and often more hypoglycemic episodes.

‡ Subjects saw, on average, between 4 and 5 fingerstick values per day. This enables subjects to

better manage their diabetes when compared to those who perform less fingersticks per day. Agreement between Guardian RT and YSI values is shown to be closer at mid-range glucose levels, as compared to agreement at low or high glucose concentrations.

‡ Subjects were more limited in their activities than what may exist in home use, and they were

provided with all their meals. Sensors were also inserted by clinic staff rather than the subjects themselves. Subjects who are more active, or with poor eating habits, may create more challenging conditions for the Guardian RT.

‡ Performance of the Guardian RT may vary depending on the glucose meter used and how well the

meter is maintained. It is important to carry out quality-control checks on the meter and code the meter according to the manufacturer's instructions to optimize performance of the Guardian RT.

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Performance Characteristics 85

Accuracy of Guardian RT Readings

In this study, YSI measurements (taken every half hour) were paired with the corresponding Guardian RT reading (taken every 5 minutes). Pairing was done by selecting the Guardian R T value closest in time to the YSI test result. Agreement was analyzed by comparing paired glucose measurements.

Agreement between the matched pair was estimated by evaluating the difference between the Guardian RT reading and the YSI measurement. The difference between them was calculated as a percentage of the YSI (Mean Absolute Percent Difference). The bias was also calculated, and it is defined as the overall difference between the Guardian RT glucose values and the YSI values. The paired glucose measurements are summarized in Table 5.1.

Table 5.1

The accuracy of the Guardian RT was also evaluated by calculating the percentage of Guardian RT readings within 20% and within 30% of the YSI reading (or within 20 mg/dl (1.1 mmol/l) in the low glucose range). Results are shown in Table 5.2

Table 5.2

*For the Low glucose range, 40-80 mg/dl (2.2-4.4 mmol/l), the value shown is the percent within 20 mg/dl (1.1 mmol/l).

Number of Paired Glucose Measurements 3941

Mean Absolute Percent Difference (+ SD) 19.7 + 18.4%

Bias -15.0 mg/dl (-0.8 mmol/l)

Plasma Glucose

Range (mg/dl)

Plasma Glucose Range (mmol/l)

Number of

Paired Readings

Percent

Within 20%

Percent

Within 30%

Overall 3941 62% 79%

40-80* 2.2-4.4 356 68% 68%

>80-120 >4.4-6.7 769 60% 77%

>120-240 >6.7-13.3 2362 62% 81%

>240 >13.3 454 61% 82%

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86 Chapter 5

The Clarke Error Grid was used to assess the clinical relevance of the differences between the Guardian RT readings and the comparative YSI measurements. The Clarke Error Grid divides a correlation plot into 5 zones. See Table 5.3.

Results in zones A and B are considered clinically acceptable, while results in zones C, D, and E are potentially dangerous and, therefore, c l i n i c ally significant errors. The Clarke Error Grid zones are labeled on the correlation plot.

Table 5.3

Zone Description

A Clinically accurate, would lead to correct treatment decisions B Would lead to benign decisions or no treatment C Would lead to overcorrection of normal glucose levels D Would lead to failure to detect and treat high or low glucose levels E Would lead to erroneous treatment decisions

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Performance Characteristics 87

Figure 5.1 is a correlation plot of Guardian RT readings versus readings from the reference method, the YSI 2300 Glucose Analyzer. It is overlaid with the Clarke Error Grid. The total number of paired data points is 3941.

Figure 5.1

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88 Chapter 5

The percent of Guardian RT readings in the above graph are presented in Table 5.4 below according to the percentage of points falling within each zone (A-E). Results are further broken down (stratified) according to the range of glucose concentrations.

Table 5.4: Stratified Clarke Error Grid Analysis

*N/A means that the Clarke Error Grid does not consider the possibility of these zones in that concentration range.

Glucose Range (mg/dl)

Number and (%) of Data Points Evaluated

A+B A B C D E

40-80 356 (9) 271

(76.1)

214 (60.1)

57 (16.0)

2 (0.6) 80

(22.5)

3 (0.8)

81-120 769 (20) 768

(99.9)

463 (60.2)

305 (39.7)

1 (0.1) N/A* N/A

121-240 2362 (60) 2352

(99.6)

1476 (62.5)

876 (37.1)

4 (0.2) N/A 6 (0.2)

>240 454 (11) 394

(86.8)

277 (61.0)

117 (25.8)

N/A 59

(13.0)

1 (0.2)

Overall 3941

(100)

3785 (96.0)

2430 (61.7)

1355 (34.4)

7 (0.2) 139

(3.5)

10 (0.2)

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Performance Characteristics 89

Precision of Guardian RT Readings

This study was also designed to look at the reproducibility of two Sensors worn simultaneously at different locations on the body. Precision was estimated by comparing the glucose readings from the two Guardian RT systems. In this study 11,475 paired Sensor Guardian RT values were obtained. On average, they were different by 17.2%. Figure 5.2 is an example of how data was paired in this study. In the graph there are two tracings of Guardian RT values. Each tracing comes from a different Guardian RT unit worn by one subject during a one-day period.

Figure 5.2

In Figure 5.2, Guardian RT device #1 is represented by a solid line, and the Guardian RT device #2 by a light-gray line.

Low and High Alerts

The ability of the Guardian RT to detect high and low glucose levels was measured in the same clinical study. Since it is important to set the alert levels in a conservative fashion, the Low Glucose Alert should be set at a value slightly higher than the value of blood glucose you want to detect, and the High Glucose Alert should be set at a value slightly lower than the value of blood glucose you want to detect.

NOTE -

Please ask your doctor which low and high alert setting is best for you.

BD Monitor Calibration Point BD Monitor Evaluation Point

Time of Day

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90 Chapter 5

The Low Glucose Alert

The Low Glucose Alert was evaluated for its ability to detect glucose levels at 70 mg/dl (3.9 mmol/l), or below, using the YSI 2300 STAT Plus glucose analyzer. As a reference, with the Low Glucose Alert set at 70 mg/dl (3.8 mmol/l), 49% (100/205) of low glucose events were detected by the Guardian RT. Better detection of low blood glucose can be obtained by setting the Low Glucose Alert level higher. For example, setting the Low Glucose Alert at 90 mg/dl (5.0 mmol/l), instead of 70 mg/dl (3.9 mmol/l), increases the ability to detect low blood glucose levels from 49% to 82% (Table 5.5).

Sometimes the Guardian RT will alert when the blood glucose levels are not low. When the Guardian RT Low Alert was set at 70 mg/dl (3.9 mmol/l) in this study, 43% of the results were considered false alerts (actual blood glucose values are greater than 85 mg/dl (4.7 mmol/l)). This percentage may be exaggerated because blood glucose may be dropping when the Guardian RT alerts. Table 5.5 shows the percent of Low Glucose readings correctly identified by the Guardian RT for specific settings.

Table 5.5

* True Alert Rates are the % of times when the glucose level was at or below the alert setting and the alert sounded.

** False Alerts Rates are the % of times when the Guardian RT Sensor alarmed but the blood glucose level was greater

than the alert setting.

Increasing the Low Alert settings will improve the ability to detect low blood glucose events, but it will also increase the frequency of Guardian RT false alerts for blood glucose levels not below the target value. You should consider this trade-off between the improved ability to detect true low blood glucose versus the increased number of false alerts when setting the low alert threshold.

Guardian RT Low

Alert Setting

(mg/dl)

Guardian RT Low

Alert Setting

(mmol/l)

True Alert Rate* False Alert Rate**

70 3.9 49% 60% 80 4.4 68% 64% 90 5.0 82% 75%

100 5.6 90% 79%

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Performance Characteristics 91

The High Glucose Alert

The High Glucose Alert was evaluated for its ability to detect glucose levels at 250 mg/dl (13.8 mmol/l), or above, using the YSI analyzer. As a reference, with the High Glucose Alert set at 250 mg/dl 13.8 mmol/l), 53% (195/365) of high glucose events were detected by the Guardian RT. Better detection of high blood glucose can be obtained by setting the High Glucose Alert level lower. For example, setting the High Glucose Alert at 190 mg/dl (10.6 mmol/l), instead of 250 mg/dl (13.8 mmol/l), increases the ability to detect high blood glucose levels from 53% to 85% (see Table 5.6).

Sometimes the Guardian RT will alert when the blood glucose levels are not high. When the Guardian RT High Alert was set at 250 mg/dl (13.8 mmol/l) in this study, 7.2% of the results were considered false alerts (actual blood glucose values are less than 225 mg/dl (12.5 mmol/l)). This percentage may be exaggerated because blood glucose may be rising when the Guardian RT alerts. Table 5.6 shows the percent of High Glucose readings correctly identified by the Guardian RT for specific settings.

Table 5.6

* True Alert Rates are the % of times when the glucose level was at or above the alert setting and the alert sounded. ** False Alerts Rates are the % of times when the Guardian RT Sensor alarmed but the blood glucose level was lower

than the alert setting.

Decreasing the High Alert settings will improve the ability to detect high blood glucose events, but it will also increase the frequency of Guardian RT false alerts for blood glucose levels not above the target value. You should consider this trade-off between the improved ability to detect true high blood glucose versus the increased number of false alerts when setting the high alert threshold.

Guardian RT High

Alert Setting

(mg/dl)

Guardian RT High

Alert Setting

(mmol/l)

True Alert Rate* False Alert

Rate**

190 10.6 85% 64% 200 11.1 81% 58% 225 12.5 67% 40% 250 13.8 53% 25%

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92 Chapter 5

Guardian RT Sensor Performance and Calibration Stability As a Function of Time

The Guardian RT Sensor may be worn for up to 3 days (72 hours) and must be calibrated at least twice a day. Two sets of data, approximately equal in number, were collected during the clinical trial. One data set was generated when the frequency of calibrations averaged 3.5 per day (Data Set A), and the other averaged 5 times a day (Data Set B). During the study, a total of 38 Sensors were evaluated in 16 individuals.

As per the stratified Clarke Error Grid analysis above (Table 5.4), agreement between Guardian RT values and YSI values tends to be poorer at low and high glucose concentrations when compared to other concentration ranges.

Guardian RT performance in the hypoglycemic range, as a function of Sensor insertion time, is characterized below. Results from the two different data sets are presented. The two populations were separated according to the number of calibrations per day. Table 5.7 represents the percentage of Data Points in the 40-80 mg/dl range that fell within 20 mg/dl. Data is presented in 12-hour increments.

Table 5.7

Data Set 0-12 hrs 12-24 hrs 24-36 hrs 36-48 hrs 48-60 hrs 60-72 hrs

A 78% 81% 73% 65% 56% 41% B 67% 70% 93% 60% 75% 38%

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Performance Characteristics 93

An analysis of the mean percentage of Absolute Relative Error (ARE %) and standard deviations, across 12-hour increments of wear periods, appears in Table 5.8 below. Both data sets are pooled together in this data.

Table 5.8: Performance As a Function of Sensor-Insertion Time

The median Sensor life from Data Sets A and B were 57.5 hours and 72.9 hours, respectively. Twenty-one of the Sensors operated for 72 hours, while the others were removed for a variety of reasons, most often because of calibration errors.

The percentage of Guardian RT readings within 20 mg/dl and 30 mg/dl of YSI readings from 40-80 mg/dl (Table 5.9), and the percentage of readings within 20% and 30% of YSI readings from 81-120 mg/dl (Table 5.10), was analyzed according to time after Sensor insertion and according to the glucoseconcentration range (as determined by the YSI analyzer).

Table 5.9

Hours From

Insertion

Mean ARE (%) Std. Dev.

0-12 hrs 24.84 20.04 12-24 hrs 19.66 16.17 24-36 hrs 16.43 15.62 36-48 hrs 18.23 19.27 48-60 hrs 16.59 14.25

>60 hrs 22.95 23.51

Percentage of Guardian RT values within

20 mg/dl of YSI laboratory readings

Percentage of Guardian RT values within

30 mg/dl of YSI laboratory readings

Glucose

Range

(mg/dl)

During first 60 hours

of Sensor wear

After 60 hours

of Sensor wear

During first 60

hours of Sensor

wear

After 60 hours of

Sensor wear

40-80 62-82% 39% 78-91% 67%

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94 Chapter 5

Table 5.10

Performance of the Guardian RT was evaluated according to the length of time since calibration. This data is not conclusive because of the limited number of data points during the final 3 hours of the 12hour calibration cycle, i.e., 10. In contrast, 3-hour time bins, earlier in the 12-hour cycle, contained hundreds of data points. This may suggest that calibrations are often required prior to the 12-hour calibration cycle.

Affects of Calibration Frequency

The average bias when Guardian RT was calibrated ~ 3.5 times a day was -20.5 + 41 mg/dl (LL: -22.40 mg/dl and UL: -18.63 mg/dl). In those calibrated ~ 5 times a day, the bias was -10.2 mg/dl + 36 mg/dl (LL: -11.74 mg/dl and UL: -8.66 mg/dl).

When comparing Guardian RT units that were calibrated less often to those calibrated more often, the following alarm performance was observed:

‡ Specificity increased 2-4% in the hypoglycemic range and decreased 0-2% in the hyperglycemic

range

‡ Sensitivity increased between 5-9% across the hyperglycemic range, and decreased 7-16% when the

alarm was set to 80 mg/dl or below, and decreased 3-7% when set between 85 and 100 mg/dl

Stratified error grid analysis also shows better performance in the hypoglycemic range when fewer calibrations are performed, i.e., 62% of data points are in Zone A when fewer calibrations were performed, whereas 58% were in Zone A when more calibrations were performed.

Percentage of Guardian RT values

within 20% of YSI laboratory readings

Percentage of Guardian RT values

within 30% of YSI laboratory readings

Glucose Range

(mg/dl)

During first 60 hours

of Sensor wear

After 60 hours of Sensor wear

During first 60 hours

of Sensor wear

After 60 hours of Sensor wear

81-120 57-66% 48% 72-84% 66%