DETECTION OF CONTAMINATION AT SENSOR CONTACTS

• US 20130018597A1
• Filed: 04/13/2012
• Published: 01/17/2013
• Est. Priority Date: 04/14/2011
• Status: Active Grant

• Current Assignee: Konamite Limited
• Original Assignee: Bayer Healthcare LLC (Bayer AG)
• Inventors: Gofman, Igor, Wu, Mu
• Granted Patent: US 9,936,903 B2
• Time in Patent Office: Days
• US Class Current: 702/23
• CPC Class Codes: A61B 2560/0276 Determining malfunction
• CPC Class Codes: A61B 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors

Abstract

Embodiments herein provide detection of contamination at one or more contacts of a sensor system. The sensor system includes a sensor assembly and an electronics assembly communicatively coupled together by one or more contacts. The sensor assembly passes a sensor signal to the electronics assembly for further processing. The electronics assembly includes a detection contact for detecting contamination on or near one or more contacts of the sensor assembly and/or the electronics assembly. A switch selectively couples the detection contact to a bias voltage during a measurement mode and to a reference voltage during a detection mode, the reference voltage being different from the bias voltage. A method of contamination detection includes switching the electronics assembly between the measurement mode and the detection mode, and monitoring for a change in the output signal received by the electronics assembly.

Claims

1. An electronics assembly comprising:

a sensor contact configured to receive a sensor signal from a sensor assembly, the sensor signal being representative of a level of an analyte in a body;

a processor coupled to the sensor contact and configured to receive the sensor signal;

a detection contact; and

a switch, controlled by the processor, configured to couple the detection contact to a bias voltage during a measurement mode and to couple the detection contact to a reference voltage during a detection mode, the reference voltage being different from the bias voltage,

wherein the processor is configured to measure a first value of the sensor signal during the measurement mode and a second value of the sensor signal during the detection mode to detect a leakage current of the sensor signal.

2. The electronics assembly of claim 1, wherein the processor is configured to compare the first value to the second value to determine whether the leakage current is present.

3. The electronics assembly of claim 2, wherein the electronics assembly is further configured to take an action based on the comparison of the first value to the second value, the action including at least one of:

activating an alarm, generating an error code, transmitting the error code to an external device, logging an error, stopping collection of data from the sensor assembly, preventing the sensor data from being used in data processing, and/or taking the leakage current into account in data processing.

4. The electronics assembly of claim 2, wherein the processor is configured to take an action if a result of the comparison between the first value and the second value is above a threshold.

5. The electronics assembly of claim 1, wherein the processor is configured to transmit the first and second values to a monitoring unit, the monitoring unit configured to determine whether the leakage current is present based on the first and second values.

6. The electronics assembly of claim 1, further comprising:

an amplifier configured to receive the sensor signal at an input terminal and to pass an amplified sensor signal to the processor, the amplified sensor signal having a voltage dependent on a current of the sensor signal at the input terminal;

wherein the amplifier is biased with the bias voltage.

7. The electronics assembly of claim 1, further comprising a battery, wherein the detection contact is configured to be coupled with a battery charger to charge the battery during a charging mode of the electronics assembly.

8. The electronics assembly of claim 7, wherein the switch comprises a first switch and the electronics assembly further comprising:

a second switch configured to couple the detection contact to the battery during the charging mode and to couple the detection contact to the first switch during the measurement mode and the detection mode.

9. The electronics assembly of claim 8, further comprising an enable contact configured to receive a control signal from the battery charger to place the electronics assembly in the charging mode.

10. The electronics assembly of claim 1, further comprising a common return contact coupled to a ground potential and configured to be coupled with the sensor assembly.

11. The electronics assembly of claim 10, wherein the reference voltage is equal to the ground potential.

12. The electronics assembly of claim 10, wherein the sensor contact, detection contact, and common return contact are disposed in a sealed portion of the electronics assembly where the electronics assembly is coupled with the sensor assembly.

13. The electronics assembly of claim 1, wherein the detection contact surrounds the sensor contact.

14. The electronics assembly of claim 1, wherein the sensor assembly includes a continuous glucose monitor configured to produce the sensor signal.

23. The system of claim 14, wherein the analyte sensor includes a continuous glucose monitor.

15. An analyte sensor system, comprising:

a sensor assembly including;

a first sensor contact;

a first ground contact; and

an analyte sensor coupled to the first sensor contact and the first ground contact, the analyte sensor configured to produce a sensor signal at the first sensor contact that is representative of a level of an analyte in a body; and

an electronics assembly coupled to the sensor assembly, the electronics assembly including;

a second sensor contact configured to be coupled with the first sensor contact to receive the sensor signal;

a second ground contact coupled to the first ground contact and to a ground potential;

a processor coupled to the second sensor contact and configured to receive the sensor signal;

a detection contact; and

a switch, controlled by the processor, configured to couple the detection contact to a bias voltage during a measurement mode and to couple the detection contact to a reference voltage during a detection mode, the reference voltage being different from the bias voltage,

wherein the processor is configured to measure a first value of the sensor signal during the measurement mode and a second value of the sensor signal during the detection mode to detect a leakage current of the sensor signal.

16. The system of claim 15, wherein the processor is configured compare the first value to the second value to determine whether the leakage current is present, and to take an action if a result of the comparison is above a threshold.

17. The system of claim 15, wherein the electronics assembly further comprises an amplifier configured to receive the sensor signal at an input terminal and to pass an amplified sensor signal to the processor, wherein the amplifier is biased with the bias voltage.

18. The system of claim 15, wherein the electronics assembly further comprises a battery, and wherein the detection contact is configured to be coupled with a battery charger to charge the battery during a charging mode of the electronics assembly.

19. The system of claim 18, wherein the electronics assembly further comprises an enable contact configured to receive a control signal from the battery charger to place the electronics assembly in the charging mode.

20. The system of claim 18, wherein the reference voltage is equal to the ground potential.

21. The system of claim 15, wherein the first and second sensor contacts, first and second ground contacts, and detection contact are disposed in a sealed portion between the electronics assembly and the sensor assembly.

22. The system of claim 15, wherein the detection contact surrounds the second sensor contact to act as a guard ring.

24. A method of contamination detection for an analyte sensor system, comprising:

receiving, by an electronics assembly, a sensor signal from a sensor assembly;

measuring a first value of the sensor signal while a detection contact of the electronics assembly is coupled to a bias voltage;

coupling the detection contact to a reference voltage, the reference voltage being different from the bias voltage;

measuring a second value of the sensor signal while the detection contact is coupled to the reference voltage; and

comparing the first value to the second value to detect a leakage current of the analyte sensor system.

25. The method of claim 24, wherein comparing the first value to the second value to detect a leakage current of the analyte sensor system comprises determining if a difference between the first value and the second value is above a threshold.

26. The method of claim 24, further comprising taking an action, by the electronics assembly, based on the comparison.

27. The method of claim 26, wherein the taking the action includes at least one of:

activating an alarm, generating an error code, transmitting the error code to an external device, logging an error, stopping collection of data from the sensor assembly, preventing the sensor data from being used in data processing, and/or taking the leakage current into account in data processing.

28. The method of claim 24, further comprising amplifying, by an amplifier of the electronics assembly, the sensor signal prior to the measuring the first value and the second value, wherein the amplifier is biased by the bias voltage.

29. The method of claim 24, further comprising coupling the detection contact to a battery of the electronics assembly during a charging mode to charge the battery.