Method and apparatus for providing dynamic multi-stage signal amplification in a medical device

• US 8,937,540 B2
• Filed: 02/24/2014
• Issued: 01/20/2015
• Est. Priority Date: 04/14/2007
• Status: Active Grant

• Current Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Original Assignee: Abbott Diabetes Care Incorporated (Abbott Laboratories Incorporated)
• Inventors: Fennell, Martin J.
• Primary Examiner(s): Tweel, Jr., John A
• Application Number:
  US14/188,659
• Publication Number:
  US 20140171773A1
• Time in Patent Office: 330 Days
• Field of Search: 340/511, 340/573.1, 422/68.1, 330/85, 204/401, 205/792
• US Class Current: 340/511
• CPC Class Codes: A61B 2560/0209 adapted for power saving
• CPC Class Codes: A61B 2560/0252 using ambient temperature
• CPC Class Codes: A61B 2560/045 with a separable interface unit, e.g. for communication
• CPC Class Codes: A61B 5/0004 characterised by the type of physiological signal transmitted
• CPC Class Codes: A61B 5/002 Monitoring the patient using a local or closed circuit, e.g. in a room or building A61B5/0017 takes precedence
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors
• CPC Class Codes: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• CPC Class Codes: A61B 5/7246 using correlation, e.g. template matching or determination of similarity
• CPC Class Codes: A61B 5/7475 User input or interface means, e.g. keyboard, pointing device, joystick
• CPC Class Codes: A61M 5/1723 using feedback of body parameters, e.g. blood-sugar, pressure measurement of body parameters A61B5/00

Abstract

Methods and apparatus for providing multi-stage signal amplification in a medical telemetry system are provided.

Claims

1. A method of processing signals from an analyte sensor, comprising:

coupling a first amplifier to a second amplifier, the first amplifier operatively coupled to a signal source;

operatively coupling an analog to digital (A/D) converter to the second amplifier;

comparing signals at an output terminal of the second amplifier to a predetermined threshold value; and

processing a signal associated with the signals at the second amplifier output terminal when another signal at the second amplifier output terminal exceeds the predetermined threshold value.

2. The method of claim 1, wherein the first amplifier includes a transimpedance amplifier.

3. The method of claim 1, wherein the first amplifier includes an inverting input terminal.

4. The method of claim 3, further including coupling a reference signal source to a noninverting input terminal of the first amplifier.

5. The method of claim 1, wherein a first output signal from the first amplifier is a predetermined ratio of a second output signal from the second amplifier.

6. The method of claim 5, wherein the first output signal is associated with a signal from the signal source.

7. The method of claim 5, wherein the first output signal and the second output signal are associated with a monitored analyte level.

8. The method of claim 1, further including configuring the signal source to receive one or more signals associated with a monitored analyte level from an analyte sensor.

9. The method of claim 1, further including operatively coupling the signal source to a glucose sensor.

10. The method of claim 9, wherein the glucose sensor comprises a plurality of electrodes including a working electrode, wherein the working electrode comprises a glucose-responsive enzyme and a mediator, wherein at least one of the glucose-responsive enzyme and the mediator is chemically bonded to a polymer disposed on the working electrode, and wherein at least one of the glucose-responsive enzyme and the mediator is crosslinked with the polymer.

11. An apparatus, comprising:

a first amplifier operatively coupled to a signal source;

a second amplifier operatively coupled to the first amplifier;

an analog to digital (A/D) converter operatively coupled to the second amplifier; and

a processing unit operatively coupled to one or more of the first amplifier, the second amplifier or the analog to digital (A/D) converter, the processing unit configured to compare signals at an output terminal of the second amplifier to a predetermined threshold value, and configured to process a signal associated with the signals at the second amplifier output terminal when another signal at the second amplifier output terminal exceeds the predetermined threshold value.

12. The apparatus of claim 11, wherein the first amplifier includes a transimpedance amplifier.

13. The apparatus of claim 11, wherein the first amplifier includes an inverting input terminal.

14. The apparatus of claim 13, further including a reference signal source operatively coupled to a noninverting input terminal of the first amplifier.

15. The apparatus of claim 11, wherein a first output signal from the first amplifier is a predetermined ratio of a second output signal from the second amplifier.

16. The apparatus of claim 15, wherein the first output signal is associated with a signal from the signal source.

17. The apparatus of claim 15, wherein the first output signal and the second output signal are associated with a monitored analyte level.

18. The apparatus of claim 11, wherein the signal source is further configured to receive one or more signals associated with a monitored analyte level from an analyte sensor.

19. The apparatus of claim 11, wherein the signal source is operatively coupled to a glucose sensor.

20. The apparatus of claim 19, wherein the glucose sensor comprises a plurality of electrodes including a working electrode, wherein the working electrode comprises a glucose-responsive enzyme and a mediator, wherein at least one of the glucose-responsive enzyme and the mediator is chemically bonded to a polymer disposed on the working electrode, and wherein at least one of the glucose-responsive enzyme and the mediator is crosslinked with the polymer.