SYSTEM AND METHOD FOR NON-INVASIVE DETERMINATION OF HEMOGLOBIN CONCENTRATION IN BLOOD
First Claim
1. A method for non-invasively determining absolute value of hemoglobin concentration in blood, the method comprising:
- directing diffused light of three or more distinct wavelengths through a human tissue bed in a time-multiplexed manner;
detecting optical signal corresponding to each wavelength by a photodetector and converting transmitted portion of optical signal into current signal;
amplifying current signal corresponding to each wavelength of light to obtain a digital voltage waveform signal;
processing the digital voltage waveform signal to obtain alternating and direct components of light corresponding to each wavelength;
obtaining a system of three equations using alternating and direct components of light corresponding to each wavelength and Beer Lambert'"'"'s law, wherein the equations comprise two unknown values of primary constituent absorbers of hemoglobin concentration and an unknown value of path length;
deriving concentration values of the two primary constituent absorbers of hemoglobin concentration; and
combining concentration values of the two primary constituents and empirically derived values of one or more secondary constituent absorbers of hemoglobin concentration in order to determine absolute value of hemoglobin concentration the one or more secondary constituent absorbers comprise at least one of carboxyhemoglobin and methemoglobin,wherein the system of equations comprise known constants representing consolidated values of the one or more secondary constituent absorbers corresponding to each wavelength of light, the known constants are derived empirically by clinical calibration and/or parameter estimation matrix.
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Accused Products
Abstract
A system and method for measurement of absolute value of hemoglobin concentration non-invasively is provided. The system comprises a probe device comprising a sliding top structurally configured to be manually slid forward and backward onto the finger seat which is positioned on top of the housing for placing a fingertip. The finger seat houses two cavities for housing a set of three light emitting diodes and a photodetector respectively. Multiple distinct wavelengths of light transmitted through the fingertip is detected by the photodetector. Further, electronic signals generated by the photodetector are processed to obtain alternating and direct components of light corresponding to each wavelength. A system of three equations are obtained including unknown values of two primary constituent absorbers and known consolidated values of one or more secondary constituent absorbers corresponding to each wavelength of light. The system of equations are then solved simultaneously derive absolute value of hemoglobin concentration.
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Citations
16 Claims
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1. A method for non-invasively determining absolute value of hemoglobin concentration in blood, the method comprising:
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directing diffused light of three or more distinct wavelengths through a human tissue bed in a time-multiplexed manner; detecting optical signal corresponding to each wavelength by a photodetector and converting transmitted portion of optical signal into current signal; amplifying current signal corresponding to each wavelength of light to obtain a digital voltage waveform signal; processing the digital voltage waveform signal to obtain alternating and direct components of light corresponding to each wavelength; obtaining a system of three equations using alternating and direct components of light corresponding to each wavelength and Beer Lambert'"'"'s law, wherein the equations comprise two unknown values of primary constituent absorbers of hemoglobin concentration and an unknown value of path length; deriving concentration values of the two primary constituent absorbers of hemoglobin concentration; and combining concentration values of the two primary constituents and empirically derived values of one or more secondary constituent absorbers of hemoglobin concentration in order to determine absolute value of hemoglobin concentration the one or more secondary constituent absorbers comprise at least one of carboxyhemoglobin and methemoglobin, wherein the system of equations comprise known constants representing consolidated values of the one or more secondary constituent absorbers corresponding to each wavelength of light, the known constants are derived empirically by clinical calibration and/or parameter estimation matrix. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A probe device for non-invasively determining absolute value of hemoglobin concentration in blood, the probe device comprising:
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a housing with a flat base; a finger seat fastened and positioned on top of the housing for placing the fingertip and housing a first cavity and a second cavity, wherein the first cavity is structurally arranged to house a set of three light emitting diodes and the second cavity is structurally arranged to house a photodetector, further wherein the three light emitting diodes are arranged in a non-parallel configuration and point towards a common direction, further wherein the three light emitting diodes emit light of distinct wavelengths; one or more snap holders for snap fitting the set of three light emitting diodes and the photodetector respectively, wherein the three light emitting diodes have similar optical and physical characteristics, a sliding top structurally configured to be manually slid forward and backward onto the finger seat; a pressure inducing flap fastened on one side of the finger seat and configured to apply increased pressure on the fingertip as the sliding top is slid forward over the finger seat, wherein based on the application of pressure on the fingertip, current signal is generated by the photodetector proportional to light transmitted through the fingertip; and a recoil spring structurally connected to the pressure inducing flap and configured to push the flap upward and release pressure as the sliding top is slid backward over the finger seat. - View Dependent Claims (16)
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Specification