System and method for a self-calibrating non-invasive sensor

• US 7,124,048 B2
• Filed: 12/08/2004
• Issued: 10/17/2006
• Est. Priority Date: 08/11/2000
• Status: Expired due to Term

• Current Assignee: Medtor Incorporated
• Original Assignee: Elekon Industries USA Incorporated (TE Connectivity Ltd. (United Kingdom))
• Inventors: Dietiker, Thomas
• Primary Examiner(s): Barlow, John
• Assistant Examiner(s): VO, HIEN XUAN
• Application Number:
  US11/007,656
• Publication Number:
  US 20060122801A1
• Time in Patent Office: 678 Days
• Field of Search: 702/104, 702/85, 702/196, 356/40, 600/320, 600/328, 600/323, 600/473, 600/476, 600/310, 600/331
• US Class Current: 702/104
• 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 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: G01J 1/08 Arrangements of light sources specially adapted for photometry standard sources, also using luminescent or radioactive material
• CPC Class Codes: G01J 2003/2866 Markers; Calibrating of scan
• CPC Class Codes: G01J 9/00 Measuring optical phase difference devices or arrangements for controlling the phase of light beams G02F1/01; Determining degree of coherence; Measuring optical wavelength spectrometry G01J3/00
• CPC Class Codes: G01N 2021/3144 for oxymetry
• CPC Class Codes: G01N 21/274 Calibration, base line adjustment, drift correction
• CPC Class Codes: G01N 21/35 using infrared light G01N21/39 takes precedence
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis
• CPC Class Codes: G01N 21/3563 for analysing solids; Preparation of samples therefor
• CPC Class Codes: G01N 21/3577 for analysing liquids, e.g. polluted water
• CPC Class Codes: G01N 2201/1211 for temperature
• CPC Class Codes: G01N 2201/12723 Self check capacity; automatic, periodic step of checking
• CPC Class Codes: H01L 27/14647 Multicolour imagers having a stacked pixel-element structure, e.g. npn, npnpn or MQW elements
• CPC Class Codes: H01L 31/03529 Shape of the potential jump barrier or surface barrier

Abstract

A non-invasive emitter-photodiode sensor which is able to provide a data-stream corresponding to the actual wavelength of light emitted thereby allowing calibration of the sensor signal processing equipment and resulting in accurate measurements over a wider variation in emitter wavelength ranges.

Claims

1. A sensor system comprising:

a probe comprising a light source and a sensor, the sensor having a probe calibration output and a calibrated probe output, wherein the probe outputs are responsive to incident light radiation received from the light source to produce signals proportional to an amplitude and a centroid wavelength of the incident light, and the probe calibration output is generated continuously while taking a physiological measurement;

a calibration circuit in signal communication with the probe and comprising an electronic calibration output responsive to the probe calibration output, and a calibrated electronic output responsive to the calibrated probe output;

a controller in signal communication with the calibration circuit and comprising a lookup table having a wavelength value output responsive to the electronic calibration output and the calibrated electronic output, wherein the wavelength value output is determined in real-time and is then used to correct physiological data derived from the signal proportional to the amplitude of the incident light; and

,

a measuring device comprising an output generated in response to the wavelength value output.

2. The sensor system of claim 1, wherein the physiological measurement and the output of the measuring device is oxygen saturation within blood.

3. The sensor system of claim 1, further comprising software that operates on the controller.

4. The sensor system of claim 3, the software comprising instructions for compensating for wavelength variation of the incident light radiation caused by changes in temperature.

5. The sensor system of claim 1, wherein the incident light radiation is coherent.

6. A sensor system comprising:

a probe comprising a light source and a sensor, the sensor having a probe calibration output and a calibrated probe output, wherein the probe outputs are responsive to incident light radiation received from the light source to produce signals proportional to an amplitude and a centroid wavelength of the incident light, and the probe calibration output is generated continuously while taking a physiological measurement;

a calibration circuit in signal communication with the probe and comprising an electronic calibration output responsive to the probe calibration output, and a calibrated electronic output responsive to the calibrated probe output;

a controller in signal communication with the calibration circuit and comprising a software-based logic responsive to the electronic calibration output and the calibrated electronic output to produce a wavelength value output is then used to correct physiological data derived from the signal proportional to the amplitude of the incident light; and

,

a measuring device comprising an output generated in response to the wavelength value output.

7. The sensor system of claim 6, wherein the physiological measurement and the output of the measuring device are oxygen saturation within blood, cardiac output, blood pressure, or vital signs.

8. The sensor system of claim 6, further comprising software that operates on the controller.

9. The sensor system of claim 8, the software comprising instructions for compensating for wavelength variation of the incident light radiation caused by changes in temperature.

10. The sensor system of claim 6, wherein the incident light radiation is coherent.

11. A sensor system comprising:

a probe comprising a light source and a sensor, the sensor having a probe calibration output and a calibrated probe output, wherein the probe outputs are responsive to incident light radiation received from the light source to produce signals proportional to an amplitude and a centroid wavelength of the incident light, and the probe calibration output is generated continuously while taking a physiological measurement;

a calibration circuit in signal communication with the probe and comprising an electronic calibration output responsive to the probe calibration output, and a calibrated electronic output responsive to the calibrated probe output;

a controller in signal communication with the calibration circuit and comprising logic responsive to the electronic calibration output to provide an output to adjust light source temperature and to produce a wavelength value output that is determined in real-time and is then used to correct physiological data derived from the signal proportional to the amplitude of the incident light; and

,

a measuring device comprising an output generated in response to the wavelength value output.

12. The sensor system of claim 11, wherein the physiological measurement and the output of the measuring device are oxygen saturation within blood, cardiac output, blood pressure, or vital signs.

13. The sensor system of claim 11, further comprising software that operates on the controller.

14. The sensor system of claim 13, the software comprising instructions for compensating for wavelength variation of the incident light radiation caused by changes in temperature.

15. The sensor system of claim 11, wherein the incident light radiation is coherent.

16. A sensor system comprising:

a probe comprising a light source and a sensor, the sensor having a probe calibration output and a calibrated probe output, wherein the probe outputs are responsive to incident light radiation received from the light source to produce signals proportional to an amplitude and a centroid wavelength of the incident light, and the probe calibration output is generated prior to taking a physiological measurement;

a calibration circuit in signal communication with the probe and comprising an electronic calibration output responsive to the probe calibration output, and a calibrated electronic output responsive to the calibrated probe output;

a controller in signal communication with the calibration circuit and comprising logic responsive to the electronic calibration output and the calibrated electronic output to produce a wavelength value output that is used to determine, in real-time, the physiological measurement, and is then used to correct physiological data derived from the signal proportional to the amplitude of the incident light.

17. The sensor system of claim 16, wherein the physiological measurement is oxygen saturation within blood, cardiac output, blood pressure, or vital signs.

18. The sensor system of claim 16, further comprising software that operates on the controller.

19. The sensor system of claim 18, the software comprising instructions for compensating for wavelength variation of the incident light radiation caused by changes in temperature.

20. The sensor system of claim 16, wherein the incident light radiation is coherent.