Two stage calibration and analyte measurement scheme for spectrophotomeric analysis

Claim 1

An apparatus for performing spectrophotometric analyte concentration measurement comprising: means for communicating beams of light each having a distinct spectral content across a tissue sample for obtaining values related to a measurement of the concentration of each of a plurality of analytes in the tissue sample; means for measuring the beams of light received across the tissue sample for obtaining light measurements; first estimating means for estimating a concentration of a collection of at least one of said plurality of analytes using said measured light measurements; means for determining whether said first estimated concentration for each of the analytes in the collection satisfies a predetermined one or more constraints; and second estimating means for estimating a concentration of the remaining analytes of said plurality of analytes when said means for determining indicates that said predetermined one or more constraints have been met; wherein said second estimating means determines an estimated measurement of the remaining analytes using said measured light and using said first estimated concentration as a substantially exact measurement of said collection of analytes.

Claim 2

An apparatus for performing spectrophotometric analyte concentration measurement comprising: means for communicating beams of light each having a distinct spectral content across a tissue sample for obtaining values related to a measurement of the concentration of each of a plurality of analytes in the tissue sample; means for measuring the beams of light received across the tissue sample for obtaining light measurements; first estimating means for estimating a concentration of a collection of at least one of said plurality of analytes using said measured light measurements; means for determining whether said first estimated concentration for each of the analytes in the collection satisfies a predetermined one or more constraints; and second estimating means for estimating a concentration of the remaining analytes of said plurality of analytes when said means for determining indicates that said predetermined one or more constraints have been met; wherein said second estimating means determines an estimated measurement of the remaining analytes using said measured light and using said first estimated concentration as a substantially exact measurement of said collection of analytes.

Claim 17

A method for determining regression coefficients for a photoplethysmographic analyte measurement system, comprising: first collecting noninvasive photoplethysmographic data from a plurality of test subjects using a predetermined number of light emitters, each said light emitter providing a distinct spectral content of light; second collecting invasive concentration measurements for each of a plurality of blood analytes from each of the test subjects; determining a first set of regression coefficients, wherein said first set: (A) has regression coefficients for each analyte of a first collection of said plurality of analytes, said first collection including at least a first analyte; and (B) is determined using at least one of: (a) said noninvasive photoplethysmographic data, and (b) at least some of said invasive concentration measurements; determining a second set of regression coefficients, said second set having regression coefficients for each analyte of a second collection of said remaining analytes not in said first collection, wherein (a) said second set is determined using at least a subcollection of said noninvasive photoplethysmographic data, and (b) said subcollection satisfies a predetermined constraint related to a concentration measurement of said first analyte obtained in said second collecting step; and determining a third set of regression coefficients, said third set having regression coefficients for each analyte of said second collection using substantially all of said noninvasive photoplethysmographic data.

Claim 18

A method for determining regression coefficients for a photoplethysmographic analyte measurement system, comprising: first collecting noninvasive photoplethysmographic data from a plurality of test subjects using a predetermined number of light emitters, each said light emitter providing a distinct spectral content of light; second collecting invasive concentration measurements for each of a plurality of blood analytes from each of the test subjects; determining a first set of regression coefficients, wherein said first set: (A) has regression coefficients for each analyte of a first collection of said plurality of analytes, said first collection including at least a first analyte; and (B) is determined using at least one of: (a) said noninvasive photoplethysmographic data, and (b) at least some of said invasive concentration measurements; determining a second set of regression coefficients, said second set having regression coefficients for each analyte of a second collection of said remaining analytes not in said first collection, wherein (a) said second set is determined using at least a subcollection of said noninvasive photoplethysmographic data, and (b) said subcollection satisfies a predetermined constraint related to a concentration measurement of said first analyte obtained in said second collecting step; and determining a third set of regression coefficients, said third set having regression coefficients for each analyte of said second collection using substantially all of said noninvasive photoplethysmographic data.

Claim 24

A method for photoplethysmographic determination of analyte concentrations in a tissue comprising: directing a plurality of beams of light through the tissue wherein each beam of light is characterized by a distinct spectral content; measuring the light transmitted through the tissue; estimating concentrations for at least one analyte in a first collection of a plurality of analytes using said light measurements; comparing said estimated concentrations for the at least one analyte in said first collection with a predetermined criteria for said estimated initial concentrations; if said estimated concentrations of said first collection of analytes satisfies said criteria then estimating a concentration for each of the remaining analytes not in said first collection of analytes using said light measurements and said estimated concentrations of said first collection of analytes as a substantially accurate estimate of the actual analyte concentration.

Claim 25

A method for photoplethysmographic determination of analyte concentrations in a tissue comprising: directing a plurality of beams of light through the tissue wherein each beam of light is characterized by a distinct spectral content; measuring the light transmitted through the tissue; estimating concentrations for at least one analyte in a first collection of a plurality of analytes using said light measurements; comparing said estimated concentrations for the at least one analyte in said first collection with a predetermined criteria for said estimated initial concentrations; if said estimated concentrations of said first collection of analytes satisfies said criteria then estimating a concentration for each of the remaining analytes not in said first collection of analytes using said light measurements and said estimated concentrations of said first collection of analytes as a substantially accurate estimate of the actual analyte concentration.