Multiplexed pathlength resolved noninvasive analyzer apparatus with dynamic optical paths and method of use thereof

Abstract

A noninvasive analyzer apparatus and method of use thereof is described comprising a near-infrared source, a detector, and a photon transport system configured to direct photons from the source to the detector via an analyzer-sample optical interface. The photon transport system includes a dynamically position light directing unit used to, within a measurement time period for a single analyte concentration determination, change any of: radius, energy, intensity, position, incident angle, solid angle, and/or depth of penetration of a beam of photons entering skin of a subject.

1 . A method for noninvasively determining an analyte concentration of a person, comprising the steps of:
 providing a near-infrared analyzer, comprising:
 at least one near-infrared source; 
 a detector; and 
 a photon transport system configured to direct photons from said source, via a sample illumination zone, to said detector via both a detection zone and a face of an analyzer-sample optical interface; 
   dynamically changing, within a time window of data collection for a single analyte concentration determination, a mean radial illumination position of incident light from said near-infrared source relative to a center of the detection zone of said analyzer-sample optical interface, said step of dynamically changing further comprising:
 directing the photons, during a first time period of the time window, to a first arc of illumination optics at a first range of radial distances from the detection zone; and 
 directing the photons, during a second time period of the time window, to a second arc of illumination optics at a second range of radial distances from the detection zone, 
 wherein at said analyzer-sample optical interface none of said first range of radial distances overlap any of said second range of radial distances. 
   
     
     
         2 . The method of  claim 1 , said step of dynamically changing a mean radial illumination position further comprising the steps of:
 at a first time, directing light from said source to a first optic; and   at a second time, directing light from said source to a second optic, said second optic in a distinct optical path not using said first optic.   
     
     
         3 . The method of  claim 2 , further comprising the step of:
 within the time window for collection of data for determination of the single analyte concentration determination, changing an effective depth of penetration of the incident light into skin of the person by at least twenty percent.   
     
     
         4 . The method of  claim 3 , further comprising the steps of:
 at a first time, directing photons from said near-infrared source to a first subset of fiber optics in a fiber optic bundle; and   at a second time, directing photons from said near-infrared source to a second subset of fiber optics in said fiber optic bundle.   
     
     
         5 . The method of  claim 4 , further comprising the step of:
 using a rotatable and selectable opaque perimeter aperture to change a cross-sectional diameter of a light beam from said near-infrared source by at least twenty-five percent within the time window.   
     
     
         6 . (canceled) 
     
     
         7 . (canceled) 
     
     
         8 . The method of  claim 1 , said step of dynamically changing, within the time window of data collection for the single analyte concentration determination, the mean radial illumination position of incident light, further comprising the steps of:
 at a first point in time, radially directing and positioning the incident light at a first radial distance from the center of the analyzer-subject interface yielding a median maximum depth of penetration in an epidermis layer of skin of the subject; and   at a second point in time, radially directing and positioning the incident light at a second radial distance from the center of the analyzer-subject interface yielding a mean maximum depth of penetration in a dermis layer of skin of the subject.   
     
     
         9 . The method of  claim 1 , further comprising the steps of, during the time window of data collection for the single analyte concentration determination:
 generating a subject specific tissue map; and   subsequently performing said step of dynamically changing a mean radial illumination position of the incident light using information from the subject-specific tissue map.   
     
     
         10 . The method of  claim 1 , said step of dynamically changing a mean radial illumination position of the incident light further comprising the steps of:
 delivering the incident light proximate at least one of:
 an edge of a detector array; and 
 a corner of a detector array. 
   
     
     
         11 . The method of  claim 1 , said step of dynamically changing a mean radial illumination position of the incident light further comprising the step of:
 delivering the incident light sequentially to at least four optical fibers proximate at least one of:
 an edge of a detector array; and 
 a corner of a detector array. 
   
     
     
         12 . The method of  claim 1 , further comprising the step of:
 dynamically changing, within the time window of data collection for the single analyte concentration determination, a solid angle of incident light striking the analyzer-tissue interface by greater than ten percent.   
     
     
         13 . The method of  claim 12 , said step of dynamically changing a solid angle further comprising the step of:
 within the time window, irradiating the subject with two solid angles of incident light overlapping by less than twenty percent.   
     
     
         14 . An apparatus for noninvasively determining an analyte concentration of a person, comprising:
 a near-infrared analyzer, comprising:
 at least one near-infrared source; 
 a detector; and
 a photon transport system configured to direct photons from said source, via a sample illumination zone, to said detector via both a detection zone and a face of an analyzer-sample optical interface, said photon transport system further comprising:
 means for dynamically changing, within a time period of data collection for a single analyte concentration determination, a radial illumination position of incident light from said near-infrared source relative to a center of the detection zone of said analyzer-sample optical interface, said means for dynamically changing the radial illumination position comprising a dynamically positioned optic system; 
 a first arc of illumination optics configured to direct the photons, during a first time period of the time window, to a first range of radial distances from the detection zone; and 
 a second arc of illumination optics configured to direct the photons, during a second time period of the time window, to a second range of radial distances from the detection zone, wherein at said analyzer-sample optical interface none of said first range of radial distances overlap than any of said second range of radial distances. 
 
 
   
     
     
         15 . (canceled) 
     
     
         16 . The apparatus of  claim 14 , said means for dynamically changing the radial position of the incident light, comprising:
 an electromechanically directed mask wheel.   
     
     
         17 . The apparatus of  claim 16 , said detector further comprising:
 a two-dimensional detector array comprising at least six, electrically connected in series, detector elements along an arc of at least forty-five degrees.   
     
     
         18 . The apparatus of  claim 14 , said means for dynamically changing the radial position of the incident light comprising an array of light emitting diodes at least eighty percent circumferentially surrounded by said detector at the analyzer-sample optical interface, said detector comprising at least one detector array. 
     
     
         19 . The apparatus of  claim 14 , said photon transport system further comprising:
 at least one fiber optic terminating at said analyzer-sample interface at a third radial distance from the detection zone of said analyzer-sample optical interface, said third radial distance both larger than said first radial distance and smaller than said second radial distance.   
     
     
         20 . The method of  claim 1 , further comprising the step of:
 directing the photons to a third range of radial distances from the detection zone at said analyzer-sample optical interface, during a third time period of the time window, using a third arc of illumination optics,   said third range of radial distances overlapping at least some of said first range of radial distances.