Multi-channel pill with integrated optical interface

• US 5,842,977 A
• Filed: 07/23/1996
• Issued: 12/01/1998
• Est. Priority Date: 07/24/1995
• Status: Expired due to Term

• Current Assignee: Johns Hopkins University
• Original Assignee: Johns Hopkins University
• Inventors: Eaton, Harry A. C., Lesho, Jeffery C.
• Primary Examiner(s): Bahr, Jennifer
• Assistant Examiner(s): WINAKUR, ERIC FRANK
• Application Number:
  US08/685,375
• Time in Patent Office: 861 Days
• Field of Search: 128/903, 128/630, 128/736, 128/631, 607/60, 607/30, 607/31, 607/32, 250/551, 600/300, 600/301, 600/549, 340/870.17
• US Class Current: 600/300
• CPC Class Codes: A61B 5/0008 Temperature signals
• CPC Class Codes: A61B 5/0017 transmitting optical signals transmission by light H04B10/00
• CPC Class Codes: Y10S 128/903 Radio telemetry

Abstract

An optical interface incorporated into a multi-channel telemetry device used principally to provide data representing physiological conditions in a human subject. Information is transmitted without the need of a bio-compatible electrical connection via an optical link which conveys calibration parameters and commands to control the operation of the telemeter. The optical link is configured to reside completely on an integrated circuit chip. Of the three channels designed into the chip by means of appropriate electronic circuitry, one of the channels measures temperature and the other two channels are dedicated to develop generic information selectively derived from other physiological conditions. Calibration information that is programmed into the telemeter by means of the optical interface is retrieved by time division multiplexing with one of the generic channels.

Claims

1. A system for improving the correlation between an output of a sensor and calibration data established for that sensors. comprising:

an integrated circuit chip;

a sensor connected to said chip for producing a first signal having a value dependent upon the measurement of a physiological parameter;

a light detector integrated on said chip;

means for producing light pulses for illuminating said light detector to produce a second signal which represents calibration data for said sensor;

memory means for storing information from said second signal;

an external receiver; and

means for telemetering said first signal and the calibration data concurrently to said receiver.

2. A system in accordance with claim 1, wherein said sensor is a temperature sensitive crystal.

3. A system in accordance with claim 1, wherein said calibration data transmitted to said receiver is combined with said first signal.

13. A system in accordance with claims 1, 4, 7, or 10, wherein said sensor is a temperature sensitive crystal which resonates at approximately 262 Khz at 25°

C.

14. A system according to claim 13, wherein said system further comprises additional sensors for producing additional signals dependent upon the measurement of additional parameters and said means for telemetering includes means for simultaneously telemetering said additional signals with said first signal and said calibration data using frequency division multiplexing.

15. A system in accordance with claims 1, 4, 7, or 10, wherein said light detector is a photodiode.

16. A system according to claim 15, wherein said system further comprises additional sensors for producing additional signals dependent upon the measurement of additional parameters and said means for telemetering includes means for simultaneously telemetering said additional signals with said first signal and said calibration data using frequency division multiplexing.

22. A system according to claims 1, 3, 4, 6, 7, 9, 10, 12, 17, 19 or 20, further comprising identification data included in said calibration data.

23. A system according to claim 22, wherein said system further comprises additional sensors for producing additional signals dependent upon the measurement of additional parameters and said means for telemetering includes means for simultaneously telemetering said additional signals with said first signal and said calibration data using frequency division multiplexing.

24. A system according to claims 1, 3, 4, 6, 7, 9, 10, 12, 17, 19 or 20, further comprising identification data time multiplexed into said first signal.

25. A system according to claim 24, wherein said system further comprises additional sensors for producing additional signals dependent upon the measurement of additional parameters and said means for telemetering includes means for simultaneously telemetering said additional signals with said first signal and said calibration data using frequency division multiplexing.

26. A system according to claim 1, 3, 4, 6, 7, 9, 10, 12, 17, 19, or 20, wherein said system further comprises additional sensors for producing additional signals dependent upon the measurement of additional parameters and said means for telemetering includes means for simultaneously telemetering said additional signals with said first signal and said calibration data using frequency division multiplexing.

4. A system for improving the correlation between an output of a sensor and calibration data established for that sensor, comprising:

an integrated circuit chip;

a sensor connected to said chip for producing a first signal having a value dependent upon the measurement of a physiological parameter;

a light detector integrated on said chip;

means for producing light pulses for illuminating said light detector to produce a second signal stored in said chip and subsequently read out when said chip is activated, said stored signal representing the calibration data for said sensor;

a current controlled oscillator receiving the calibration data as an input;

a sine shaping circuit receiving an output from said oscillator for substantially attenuating any odd harmonics present in an output from said oscillator and producing an output signal;

means for amplitude modulating said first signal by the output signal from said sine shaping circuit to produce a third signal; and

means for telemetering said third signal to an external receiver.

5. A system in accordance with claim 4, wherein said sensor is a temperature sensitive crystal.

6. A system in accordance with claim 4, wherein said calibration data transmitted to said external receiver is combined with said first signal.

7. A system for propagating a signal from a sensor located inside a human body to a point outside the body which requires correlation between an output of the sensor and calibration data established for that sensor, comprising:

an integrated circuit chip;

a sensor connected to said chip for producing a first signal having a value dependent upon the measurement of a physiological parameter detected within a human body;

a light detector integrated on said chip;

means for producing light pulses for illuminating said light detector to produce a second signal which represents the calibration data for said sensor;

memory means for storing information from said second signal; and

means for concurrently telemetering said first signal and contents of said memory means to and external receiver.

8. A system in accordance with claim 7, wherein said sensor is a temperature sensitive crystal.

9. A system in accordance with claim 7, wherein said contents of said memory means transmitted to said external receiver is combined with said first signal.

10. A system for propagating a signal from a sensor located inside a human body to a point outside the body which requires correlation between an output of the sensor and calibration figures for that sensor, comprising:

an integrated circuit chip;

a sensor connected to said chip for producing a first signal having a value dependent on the measurement of a physiological parameter detected within a human body;

a light detector integrated on said chip;

means for producing light pulses for illuminating said light detector to produce a second signal stored in a memory on said chip and subsequently read out when said chip is activated, said stored signal representing the calibration data for said sensor;

a current controlled oscillator receiving said calibration data as its input;

a sine shaping circuit receiving an output of said oscillator and substantially attenuating any odd harmonics present in the output of said oscillator;

means for amplitude modulating said first signal by the output signal from said sine shaping circuit to produce a third signal; and

means for telemetering said third signal to an external receiver.

11. A system in accordance with claim 10, wherein said sensor is a temperature sensitive crystal.

12. A system in accordance with claim 10, wherein said calibration data transmitted to said external receiver is combined with said first signal.

17. A system for propagating a signal from a sensor located inside an enclosure to a point outside the enclosure which requires correlation between an output of the sensor and calibration data established for that sensor, comprising:

an integrated circuit chip;

a sensor connected to said chip for producing a first signal having a value dependent upon the measurement of a parameter inside an enclosure;

a light detector integrated on said chip;

means for producing light pulses for illuminating said light detector to produce a second signal which represents the calibration data for said sensor;

memory means for storing information from said second signal;

an external receiver; and

means for telemetering said first and second signals concurrently to said receiver.

18. A system in accordance with claim 17, wherein said sensor is a temperature sensitive crystal.

19. A system in accordance with claim 17, wherein said calibration data transmitted to said external receiver is combined with said first signal.

20. A system for improving the correlation between the output of a sensor and the calibration data established for that sensor, comprising:

an integrated circuit chip;

a sensor connected to said chip for producing a first signal having a value dependent upon a physical measurement;

a light detector integrated on said chip;

means for producing light pulses for illuminating said light detector to produce a second signal which represents the calibration data for said sensor;

memory means for storing information from said second signal;

an external receiver;

means for combining said first signal and said stored information producing a third signal; and

means for telemetering said third signal to said external receiver.

21. A system in accordance with claim 20, wherein said sensor is a temperature sensitive crystal.

27. A method for improving the correlation between an output of a sensor and calibration data established for that sensor comprising the steps of:

(a) providing an integrated circuit chip connected to said sensor;

(b) integrating a light detector on said chip;

(c) producing light pulses for illuminating said light detector at the time of manufacture of said chip to produce a signal which represents the calibration data for said sensor stored in a memory on said chip; and

(d) activating said sensor at the time of installation to read out said stored signal.

28. A method in accordance with claim 27, wherein said light detector comprises a photodiode.

29. A method according to claim 27, wherein said calibration data according to step (c) includes identification data.

30. A method according to claim 27, further comprising the steps of:

(e) producing additional signals dependent upon the measurement of additional parameters; and

,

(f) simultaneously telemetering the additional signals with the first signal and the calibration data by frequency division multiplexing.