METHOD AND APPARATUS FOR PROVIDING DYNAMIC MULTI-STAGE SIGNAL AMPLIFICATION IN A MEDICAL DEVICE

• US 20080252443A1
• Filed: 04/14/2008
• Published: 10/16/2008
• 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.
• Granted Patent: US 7,768,387 B2
• Time in Patent Office: Days
• US Class Current: 340/539.12
• 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. An apparatus, comprising:

a first amplifier having at least one input terminal and an output terminal, the at least one input terminal coupled to a signal source, the output terminal configured to provide a first output signal;

a second amplifier having at least one input terminal and an output terminal, the at least one input terminal coupled to the output terminal of the first amplifier, the output terminal of the second amplifier configured to provide a second output signal;

a processor operatively coupled to receive the first output signal and the second output signal;

wherein the first output signal is a predetermined ratio of the second output signal; and

further

wherein the first output signal and the second output signal are associated with a monitored analyte level of a user.

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

3. The apparatus of claim 1 wherein the monitored analyte level includes glucose level.

4. The apparatus of claim 1 wherein the at least one input terminal of the first amplifier includes an inverting input terminal.

5. The apparatus of claim 4 further including a reference signal source coupled to a noninverting input terminal of the first amplifier.

6. The apparatus of claim 1 wherein the second amplifier includes a gain of approximately two.

7. The apparatus of claim 1 wherein the first output signal is associated with a signal level from the signal source.

8. The apparatus of claim 1 further including an analog to digital converter coupled to the output terminals of the first and second amplifiers.

9. The apparatus of claim 8 wherein the analog to digital (A/D) converter is a 12 bit A/D converter.

10. The apparatus of claim 8 further including a processor operatively coupled to the A/D converter for processing the one or more signals received at the one or more first amplifier output terminal and the second amplifier output terminal.

11. The apparatus of claim 10 wherein the processor is configured to compare the one or more signals received at the one or more first amplifier output terminal and the second amplifier output terminal to a predetermined threshold value.

12. The apparatus of claim 11 wherein the predetermined threshold value includes approximately 4,000 bits.

13. The apparatus of claim 11 wherein the processor is configured to process a signal associated with one of the one or more signals received at the one or more first amplifier output terminal and the second amplifier output terminal when another signal associated with the other one of the one or more signals received at the one or more first amplifier output terminal and the second amplifier output terminal exceeds the predetermined threshold value.

14. A method, comprising:

receiving a first signal having a first signal resolution and associated with a monitored analyte level of a user;

receiving a second signal having a second signal resolution and associated with the monitored analyte level of the user;

comparing the received first signal to a predetermined threshold level; and

processing one of the received first or the second signals based on the comparing step.

15. The method of claim 14 wherein the predetermined threshold level includes approximately 4,000 bits.

16. The method of claim 14 wherein when the received first signal does not exceed the predetermined threshold level, processing the first signal.

17. The method of claim 14 wherein when the received first signal exceeds the predetermined threshold level, processing the second signal.

18. A data processing device, comprising:

a multi stage amplifier unit configured to receive a signal and to generate a plurality of amplifier unit output signals each corresponding to a monitored analyte level of a patient;

an analog to digital (A/D) conversion unit operatively coupled to the multi-stage amplifier unit configured to digitally convert the plurality of amplifier unit output signals; and

a processor unit operatively coupled to the A/D conversion unit, the processor unit configured to process one of the plurality of digitally converted amplifier unit output signals.

19. The device of claim 18 further including a data communication unit operatively coupled to the processor unit, and configured to transmit the digitally converted and processed amplifier unit output signal.

20. The device of claim 19 wherein the data communication unit includes an RF transmitter for wireless data transmission to a remote device.