Digital ASIC sensor platform

• US 9,693,714 B2
• Filed: 02/07/2013
• Issued: 07/04/2017
• Est. Priority Date: 02/10/2012
• Status: Active Grant

• Current Assignee: Senseonics, Incorporated (Senseonics Holdings, Inc.)
• Original Assignee: Senseonics, Incorporated (Senseonics Holdings, Inc.)
• Inventors: DeHennis, Andrew, Colvin, Jr., Arthur E.
• Primary Examiner(s): Winakur, Eric
• Assistant Examiner(s): Fardanesh, Marjan
• Application Number:
  US13/761,839
• Publication Number:
  US 20130211213A1
• Time in Patent Office: 1,608 Days
• Field of Search: None
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/076 Permanent implantations telemetry using implanted circuitry A61B5/0031; implanted stimulators for therapy A61N1/3605, A61N1/362, A61N1/372
• CPC Class Codes: A61B 5/1451 for interstitial fluid
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/14556 by fluorescence A61B5/14555 takes precedence
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/6861 Capsules, e.g. for swallowing or implanting
• 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

Abstract

The present invention relates to an optical sensor that may be implanted within a living animal (e.g., a human) and may be used to measure the concentration of an analyte in a medium within the animal. The optical sensor may wirelessly receive and may be capable of bi-directional data communication. The optical sensor may include a semiconductor substrate in which various circuit components, one or more photodectors and/or a light source may be fabricated. The circuit components fabricated in the semiconductor substrate may include a comparator, an analog to digital converter, a temperature transducer, a measurement controller, a rectifier and/or a nonvolatile storage medium. The comparator may output a signal indicative of the difference between the outputs of first and second photodetectors. The measurement controller may receive digitized temperature, photodetector and/or comparator measurements and generate measurement information, which may be wirelessly transmitted from the optical sensor.

Claims

1. A method of controlling an optical sensor, the method comprising:

(a) wirelessly receiving, using an inductive element and an input/output circuit of the optical sensor, a measurement command and power, wherein the input/output circuit is fabricated in a semiconductor substrate of the optical sensor;

(b) following receipt of the measurement command, using a measurement controller fabricated in the semiconductor substrate to turn a light source of the optical sensor on and off one or more times, wherein the light source is configured to, when turned on, irradiate indicator molecules having an optical characteristic responsive to a concentration of an analyte with excitation light, the indicator molecules being configured to interact with the analyte in a medium within a living animal;

(c) while the light source is turned on, using the measurement controller to;

(i) control a temperature transducer mounted on or fabricated in the semiconductor substrate to generate a first analog temperature measurement signal indicative of a temperature of the optical sensor;

(ii) control a first photodetector mounted on or fabricated in the semiconductor substrate to generate a first analog light measurement signal indicative of the amount of light received by the first photodetector, wherein the light received by the first photodetector includes light emitted by the indicator molecules;

(iii) control a second photodetector mounted on or fabricated in the semiconductor substrate to generate a second analog light measurement signal indicative of the amount of light received by the second photodetector; and

(iv) control a comparator fabricated in the semiconductor substrate to generate an analog light difference measurement signal indicative of a difference between the first and second analog light measurement signals; and

(d) while the light source is turned off, using the measurement controller to;

(i) control the temperature transducer to generate a second analog temperature measurement signal indicative of a temperature of the optical sensor;

(ii) control the first photodetector to generate a first analog ambient light measurement signal indicative of the amount of light received by the first photodetector; and

(iii) control the second photodetector to generate a second analog ambient light measurement signal indicative of the amount of light received by the second photodetector;

(e) while the light source is turned on or turned off, using the measurement controller to;

(i) control an analog to digital converter (ADC) fabricated in the semiconductor substrate to convert the first analog temperature measurement signal to a first digital temperature measurement signal;

(ii) control the ADC to convert the first analog light measurement signal to a first digital light measurement signal;

(iii) control the ADC to convert the second analog light measurement signal to a second digital light measurement signal;

(iv) control the ADC to convert the analog light difference measurement signal to a digital light difference measurement signal;

(v) control the ADC to convert the second analog temperature measurement signal to a second digital temperature measurement signal;

(vi) control the ADC to convert the first ambient analog light measurement signal to a first digital ambient light measurement signal; and

(vii) control the ADC to convert the second analog ambient light measurement signal to a second digital ambient light measurement signal; and

(f) transmitting, using the input/output circuit and the inductive element, (i) the first digital temperature measurement signal, (ii) the first digital light measurement signal, (iii) the second digital light measurement signal, (iv) the digital light difference measurement signal, (v) the second digital temperature measurement signal, (vi) the first digital ambient light measurement signal and (vii) the second digital ambient light measurement signal.

2. The method of claim 1, wherein the optical sensor is a chemical or biochemical sensor.

3. The method of claim 1, further comprising:

reading calibration information stored in a nonvolatile storage medium fabricated in the semiconductor substrate; and

controlling the light source in accordance with the calibration information.

4. The method of claim 1, further comprising transmitting, using the input/output circuit and inductive element, identification information stored in a nonvolatile storage medium fabricated in the semiconductor substrate.

5. The method of claim 1, further comprising using a field strength measurement circuit to determine whether a current produced from the wirelessly received power is above a threshold.

6. The method of claim 1, wherein the indicator molecules are signal channel indicator molecules, and the method further comprises:

irradiating the signal channel indicator molecules and reference channel indicator molecules of the optical sensor with excitation light emitted by the light source when turned on, wherein the reference channel indicator molecules are configured to not interact with the analyte in the medium within the living animal;

receiving, by the first photodetector, light emitted by the signal channel indicator molecules; and

receiving, by the second photodetector, light emitted by the reference channel indicator molecules.

7. The method of claim 1, wherein the living animal is a living human being.

8. The method of claim 1, wherein the medium is interstitial fluid.

9. The method of claim 8, wherein the analyte is glucose.

10. The method of claim 8, wherein the analyte is oxygen.

11. The method of claim 1, wherein the medium is blood.

12. The method of claim 1, wherein the indicator molecules are fluorescent indicator molecules.