FILTERED DETECTOR ARRAY FOR OPTICAL PATIENT SENSORS

• US 20130060104A1
• Filed: 09/07/2011
• Published: 03/07/2013
• Est. Priority Date: 09/07/2011
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Nellcor Puritan Bennett LLC (Medtronic Plc)
• Inventors: Schlottau, Friso
• Granted Patent: US 9,037,204 B2
• Time in Patent Office: Days
• US Class Current: 600/310
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/14558 by polarisation

Abstract

The present embodiments relate generally to patient monitoring system and, more particularly, to optical patient monitoring systems. In an embodiment, a physiological sensor includes a broadband emitter configured to emit two or more wavelengths of light into the tissue of a patient. The sensor also includes a charge coupled device (CCD) or complementary metal-oxide semiconductor (CMOS) photodetector array comprising a plurality of photodetectors. Each photodetector in the photodetector array is configured to receive the light from the tissue of the patient and to produce a corresponding output signal. Additionally, the sensor also includes one or more filter layers disposed on the plurality of photodetectors. The filter layers are configured to only allow light of particular wavelengths, polarizations, or both, to be received by each of the plurality of photodetectors.

Claims

1. A physiological sensor, comprising:

an emitter configured to emit two or more wavelengths of light into the tissue of a patient;

a charge coupled device (CCD) or complementary metal-oxide semiconductor (CMOS) photodetector array comprising a plurality of photodetectors, wherein each photodetector is configured to receive the light from the tissue of the patient and to produce a corresponding output signal; and

one or more filter layers disposed on the plurality of photodetectors and configured to only allow light of particular wavelengths, polarizations, or both, to be received by each of the plurality of photodetectors.

2. The sensor of claim 1, wherein the emitter comprises a plurality of narrowband LEDs or a broadband emitter.

3. The sensor of claim 2, wherein the broadband emitter comprises a phosphor-modified LED emitter.

4. The sensor of claim 1, wherein the photodetector array comprises a linear or two-dimensional array comprising two or more photodetectors.

5. The sensor of claim 1, wherein the one or more filter layers comprise a graded filter layer.

6. The sensor of claim 1, wherein the one or more filter layers comprise a dielectric stack filter layer.

7. The sensor of claim 1, wherein the one or more filter layers comprise an RGB filter layer.

8. The sensor of claim 1, wherein the one or more filter layers comprise a polarization filter layer.

9. The sensor of claim 1, wherein the same one or more filter layers are disposed over more than one of the plurality of photodetectors in the photodetector array.

10. A method of measuring a physiological parameter of a patient comprising:

emitting light into a tissue of the patient using a broadband emitter;

filtering the light received from the tissue of the patient using one or more filters configured to block a portion of the light based on either the wavelength of the light, the polarization of the light, or both; and

measuring the light that traverses the one or more filters using a charge-coupled device (CCD) or complementary metal-oxide semiconductor (CMOS) detector array comprising a plurality of photodetectors.

11. The method of claim 10, wherein emitting light comprises emitting light into the tissue of the patient using a phosphor-modified LED emitter.

12. The method of claim 10, wherein measuring the light comprises measuring the light that traverses the one or more filters using a detector array comprising a plurality of photodetectors, wherein each photodetector comprises a plurality of photodetection layers.

13. The method of claim 10, wherein filtering the light comprises filtering the light received from the tissue of the patient using one or more filters comprising a graded or multi-segmented filter.

14. The method of claim 10, wherein filtering the light comprises filtering the light received from the tissue of the patient using one or more filters comprising a dielectric stack, a RGB filter, a polarization filter, or any combination thereof.

15. The method of claim 10, wherein filtering the light comprises filtering the light received from the tissue of the patient using one or more filters, wherein the same one or more filters are disposed over two or more of the plurality of photodetectors in the photodetector array.

16. A patient monitoring system comprising:

an optical patient sensor comprising;

a broadband emitter configured to emit light over a range of wavelengths into the tissue of a patient; and

a filtered charge-coupled device (CCD) or complementary metal-oxide semiconductor (CMOS) detector array comprising a plurality of photodetectors disposed beneath one or more filters, wherein the plurality of photodetectors is configured to receive a filtered portion of the light from the tissue and produce corresponding plurality of output signals, wherein the filtered portion of the light comprises light having a particular wavelength, polarization, or both; and

a patient monitor comprising a processor configured to;

receive the plurality of output signals from the plurality of photodetectors; and

calculate a physiological parameter of the patient based, at least in part, on the received plurality of output signals.

17. The system of claim 16, wherein a portion of the plurality of photodetectors is configured to receive the same filtered portion of the light from the tissue of the patient.

18. The system of claim 17, wherein the processor is configured to:

compare a portion of the plurality of output signals, wherein the portion of the plurality of output signals correspond to the portion of the plurality of photodetectors;

discard one or more of the portion of the plurality of output signals that differ from an average output signal by more than a threshold value.

19. The system of claim 16, wherein the one or more filters comprise a graded or multi-segmented filter.

20. The system of claim 16, wherein the one or more filters comprise a dielectric stack filter, a RGB filter, a polarization filter, or any combination thereof.