WPI IGS100 User manual

IGS100
Implantable Glucose Sensor
World Precision Instruments
INSTRUCTION MANUAL
Serial No._____________________
011310
www.wpiinc.com

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Copyright © 2009 by World Precision Instruments, Inc. All rights reserved. No part of this publication
may be reproduced or translated into any language, in any form, without prior written permission of
World Precision Instruments, Inc.
CONTENTS
ABOUT THIS MANUAL ......................................................................................................1
INTRODUCTION ..................................................................................................................2
Notes and Warnings .....................................................................................................2
INSTRUMENT DESCRIPTION ..........................................................................................2
Parts List ............................................................................................................................2
Unpacking ........................................................................................................................2
OPERATING INSTRUCTIONS ...........................................................................................3
Conditioning the Sensor ............................................................................................3
Preparing Solution for Calibration ...........................................................................3
Calibrating the IGS100 .................................................................................................3
SENSOR CARE AND MAINTENANCE ...........................................................................5
Storing the Sensor .........................................................................................................5
Maintaining the Sensor ...............................................................................................5
Sterilizing the Sensor ....................................................................................................5
ACCESSORIES .......................................................................................................................6
TROUBLESHOOTING .........................................................................................................6
SPECIFICATIONS ..................................................................................................................6
WARRANTY ..........................................................................................................................7
Claims and Returns .......................................................................................................7
Repairs ...............................................................................................................................7

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ABOUT THIS MANUAL
The following symbols are used in this guide:
This symbol indicates a CAUTION. Cautions warn against actions that
can cause damage to equipment. Please read these carefully.
This symbol indicates a WARNING. Warnings alert you to actions that
can cause personal injury or pose a physical threat. Please read these
carefully.
NOTES and TIPS contain helpful information.
Fig. 1–IGS100 sensor
Fig. 2–Tip of the sensor showing the coil holding the enzyme saturated cotton
plug. The diameter of the coiled tip is about 600µm.

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INTRODUCTION
IGS100 implantable glucose sensor for real-time monitoring is an
amperometric microsensor that can be used in vivo. The implantable,
sensing tip is slightly larger than a half-millimeter in diameter. The tip is
comprised of a metal coil with an enzyme-soaked cotton core. A proprietary
coating covers the entire tip. As the sensor is used, the enzyme is consumed.
The tip design resists contamination from biological materials, which
significantly improves the life of the sensor. Depending on measurement
conditions, IGS100 may be used in vivo for weeks or even months. When
not in use, it has a six-month shelf life.
Notes and Warnings
NOTE: The sensor must be polarized for at least 4 hours in 5mM glucose
solution prior to use.
INSTRUMENT DESCRIPTION
Parts List
After unpacking, verify that there is no visible damage to the sensor. Verify
that all items are included:
(1) IGS100 Glucose sensor
(1) Instruction Manual
(1) Sensor Performance Evaluation
Unpacking
Upon receipt of this sensor, make a thorough inspection of the contents and
check for possible damage. Missing cartons or obvious damage to cartons
should be noted on the delivery receipt before signing. Concealed damage
should be reported at once to the carrier and an inspection requested.
Please read the section entitled “Claims and Returns” on page 7 of this
manual. Please contact WPI Customer Service if any parts are missing at
941.371.1003 or [e-mail].
The IGS100 sensor is shipped in a sealed, rigid plastic, hinged box with
foam padding to avoid damage to your sensor during shipment.
KEEP THE SENSOR STORAGE BOX and all the documentation in a safe
place. The storage box allows you to store the sensor safely with the tip
suspended. The test date and serial number of each sensor is printed on the
bottom of its box. Use of the sensor should begin within 30 days of receipt.

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Returns: Do not return any goods to WPI without obtaining prior approval
(RMA # required) and instructions from WPI’s Returns Department. Goods
returned (unauthorized) by collect freight may be refused. If a return
shipment is necessary, use the original container, if possible. If the original
container is not available, use a suitable substitute that is rigid and of
adequate size. For further details, please read the section entitled “Claims
and Returns” on page 7 of this manual.
OPERATING INSTRUCTIONS
Conditioning the Sensor
1. Turn on the free radical analyzer.
2. Set the poise voltage on the free radical analyzer to +600mV.
3. Plug the IGS100 glucose sensor into the microsensor cable (WPI
#91580) and plug the other end into the free radical analzyer.
4. Immerse the sensor element into a 5mM glucose solution with 0.05M
PBS buffer (pH=7.4). It takes about 3-4 hours to stabilize the first time.
Preparing Solution for Calibration
Prepare a 2M glucose standard solution by dissolving 7.2g glucose into
20mL distilled water. Let the solution stand overnight at room temperature
to allow equilibration of anomers. Store solution at 4ºC.
Calibrating the IGS100
1. Condition the sensor as described above.
2. Remove the sensor from the glucose solution. Rinse the sensor with
distilled water.
3. Immerse the glucose sensor tip into 20mL of 0.05M PBS solution.
4. Place a magnetic stirring bar into the solution. turn on the stirrer so that
the bar is stirring at a moderate rate.
NOTE: The rate of the stirrer should not be modified once it is set.
5. After waiting a few minutes for the current to stabilize, record its value.
Typically the current should be a few nA or less. ( It should not exceed
20nA.)
NOTE: The calibration should be carried out at the temperature at which
the measurement of glucose is to be made. This can be accomplished
by placing the vial and stand in a water bath at the appropriate

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temperature, and allowing the temperature of the solution in the bottle
to equilibrate with water bath.
5. Once the current has achieved a stable value, record this value or use
zero function in the instrument to set the baseline to zero.
6. Add 20µl of the 2M stock glucose solution into the 20mL of 0.05M PBS
buffer solution. The concentration of glucose in the solution is now
2mM. The current output will rapidly increase upon addition of glucose
and reach a plateau in a couple minutes.
7. Add an additional 20µl aliquot of 2M stock glucose solution when the
signal reaches a plateau. The concentration of glucose in the solution is
increasing by 2mM with the addition of each aliquot. When the current
output reaches a plateau, record the value displayed on the free radical
analyzer.
8. Repeat step 7 another three times. A typical calibration plot looks
similar to the one shown in Fig. 3.
2mM glucose
2.86nA
10mM glucose
14.72nA
8mM glucose
11.91nA
6mM glucose
9.18nA
4mM glucose
6.00nA
Glucose (nA)
Time (seconds)
Fig. 3–Calibration plot showing five aliquots of 2M glucose injected into PBS solution
9. Plot the current readings against the total glucose concentration on
a graph. The slope of this line indicates the sensitivity of the glucose
sensor. Once the sensitivity of the glucose sensor is known, the sensor is
ready for experimental use.

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Fig. 4–Calibration data plotted shows the linear rise in current with the increase of
the solution molarity
NOTE: Since the enzyme is consumed as the sensor is used, the sensor
should be re-calibrated before each experiment.
SENSOR CARE AND MAINTENANCE
Storing the Sensor
STANDBY: If the sensor is being used the next day, it should be stored with
the tip suspended in 5mM glucose solution at 4ºC.
LONG-TERM: For long-term storage of more than one week, rinse the
sensor tip with distilled water and let it dry. Protect the tip and store the
sensor dry at 4ºC. It is best to store the sensor in its original box with the tip
suspended.
Maintaining the Sensor
After each use, rinse the sensor with distilled water.
Sterilizing the Sensor
The sensor can be sterilized chemically using an appropriate disinfectant
(for example, Cidex, WPI#7364).
CAUTION: Do not use alcohol on the sensor.

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ACCESSORIES
Table 1: Accessories
Part Number Description
91580 Microsensor cable
TROUBLESHOOTING
If you have a problem/issue with your IGS100 sensor, contact the WPI
Technical Support team at 941.371.1003 or [e-mail].
SPECIFICATIONS
The IGS100 sensor conforms to the following specifications:
In Vitro Precision Coefficient of variation (CV) ≤5%
Glucose Range 36 - 450mg/dl (or 2-25mM)
Response Time 100-300 sec
Interference Species Acetaminophen, ascorbic acid, uric acid
Overall Length 5 cm
Sensor Size Diameter: 0.6 mm
Active sensor length: 1.5 mm
Flex body: 35 mm
Reference Electrode Ag/AgCl integral
Polarization Voltage 0.6V
Sensor Life 3-4 months in solutions at room
temperature under continuous
polarization; 15-30 days in vivo.
Shelf Life 6 months
Operating Conditions 20°–40° C (68°–104° F)
Storage Conditions 4°–25° C (50°–77° F)