MULTI-STREAM SENSOR FOR NONINVASIVE MEASUREMENT OF BLOOD CONSTITUENTS
The present disclosure relates to a sensor having a set of photodetectors that are arranged at various locations to enable the measurement of blood glucose. The photodetectors are arranged across multiple locations. For example, the detector may comprise multiple photodetector arrays that are arranged to have a sufficient difference in mean path length to allow for noise cancellation and noise reduction. Walls may be used in the detector to separate individual photodetectors and prevent mixing of detected optical radiation between the different locations on the measurement site. A window may also be employed to facilitate the passing of optical radiation at various wavelengths for measuring glucose in the tissue.
1 - 13 . (canceled)
14 . A physiological, noninvasive detector configured to detect optical radiation from a tissue site in order to measure physiological parameters of pulsating blood in living tissue, said detector comprising:
a set of photodetectors that each provide a signal stream indicating optical radiation that has been transmitted through the tissue site from a plurality of emitters, wherein the set of photodetectors are arranged in a logarithmically spaced configuration that provides a variation in path lengths between at least some of the photodetectors; and
a conversion processor that provides information indicating an analyte in the tissue site based on ratios of pairs of the signal streams.
15 . The detector of claim 14 , wherein the set of photodetectors are arranged in a row.
16 . The detector of claim 14 , wherein the set of photodetectors are contained in optically separate compartments.
17 . The detector of claim 14 , wherein the conversion processor comprises a set of transimpedance amplifiers that convert the signal streams from the set of photodetectors into a signal having a respective stream for each photodetector.
18 . The detector of claim 14 , wherein the conversion processor comprises a set of switched capacitor circuits configured to convert the signal streams from the set of photodetectors into a digital signal having a respective stream for each photodetector.
19 . The detector of claim 14 , wherein a photodetector of the set of photodetectors comprises a set of two photodiodes coupled together.
20 . The detector of claim 14 , wherein a photodetector of the set of photodetectors comprises a set of three photodiodes coupled together.
21 . The detector of claim 14 , wherein a photodetector of the set of photodetectors comprises a set of four photodiodes coupled together.
22 . The detector of claim 14 , wherein a photodetector of the set of photodetectors comprises a set of nine photodiodes coupled together.
23 . A physiological, noninvasive detector configured to detect optical radiation from a tissue site in order to measure physiological parameters of pulsating blood in living tissue, said detector comprising:
a set of photodetectors that each provide a signal stream indicating optical radiation of light emitted from a plurality of emitters and attenuated by the tissue site, wherein the set of photodetectors are arranged in a spacial configuration that provides a variation in path lengths between at least some of the photodetectors, and the set of photodetectors are arranged in at least one row; and
a conversion processor that provides information indicating an analyte in the tissue site based on ratios of pairs of the signal streams.
24 . The detector of claim 23 , wherein the set of photodetectors are arranged in at least two rows.
25 . The detector of claim 23 , wherein the row of photodetectors is arranged to have decreasing separation distances between photodetectors in the row.
26 . The detector of claim 23 , wherein the set of photodetectors are arranged having different separation distances.
27 . The detector of claim 23 , wherein the set of photodetectors comprise a set of four photodiodes coupled together.
28 . The detector of claim 23 , wherein a photodetector in the set of photodetectors comprises a set of two photodiodes coupled together.
29 . A physiological, noninvasive sensor configured to obtain physiological information from a patient, the sensor comprising:
an emitter configured to emit light into a digit or ear of the patient; and
a set of photodetectors configured to detect optical radiation that has been transmitted through the digit or ear and each generate a signal responsive to the detected optical radiation, the set photodetectors being arranged in a two-dimensional grid that provides a variation in path lengths between at least some of the photodetectors, the signals being usable to determine physiological information concerning the patient.
30 . The sensor of claim 29 , wherein the set of photodetectors are arranged in a zig-zag pattern.
31 . The sensor of claim 29 , wherein the physiological information is a total hemoglobin measurement.
32 . The sensor of claim 29 , wherein a patient monitor receives the signal and uses a processor to determine and display the physiological information.
33 . The sensor of claim 29 , wherein photodetectors of the set are contained in optically separate compartments.