Compact apparatus for noninvasive measurement of glucose through near-infrared spectroscopy

Abstract

The invention involves the monitoring of a biological parameter through a compact analyzer. The preferred apparatus is a spectrometer based system that is attached continuously or semi-continuously to a human subject and collects spectral measurements that are used to determine a biological parameter in the sampled tissue. The preferred target analyte is glucose. The preferred analyzer is a near-IR based glucose analyzer for determining the glucose concentration in the body.

1 . An apparatus for noninvasive measurement of an analyte property using near-infrared spectroscopy, comprising: 
 a sample module;    a base module physically separated from said sample module;    a communication bundle for coupling said base module to said sample module;    a source located in at least one of said base module and said sample module;    a first optic located in an optical train after said source, for removing photonic heat energy from said optical path; and    a second optic located in said optical train after said first optic and before a sample site.    
     
     
         2 . The apparatus of  claim 1 , said second optic substantively contacting an area about said sample site and aiding in mechanical stabilization of a collection optic, said collection optic being positioned in close proximity to said sample site to reduce specular reflectance.  
     
     
         3 . The apparatus of  claim 1 , said communication bundle carrying any of: 
 any of optical and electrical signals between said base module and said sample; and    power between said sample module and said base module.    
     
     
         4 . The apparatus of  claim 1 , at least one of said base module and said sample module further comprising a detector array.  
     
     
         5 . The apparatus of  claim 4 , wherein said detector array is optically coupled to a grating.  
     
     
         6 . The apparatus of  claim 5 , wherein at least one of said first optic and said second optic removes source light otherwise detected by said detector as second order from of said grating.  
     
     
         7 . The apparatus of  claim 1 , said analyte property comprising: 
 glucose concentration.    
     
     
         8 . The apparatus of  claim 7 , said analyzer either continuously or semi-continuously monitoring said glucose concentration.  
     
     
         9 . The apparatus of  claim 7 , further comprising: 
 means for bias correcting at least one of spectra (X) and glucose concentration data (Y).    
     
     
         10 . The apparatus of  claim 1 , said sample module performing either continuous or semi-continuous automated sampling of said sample site, wherein time between sampling comprises any of about 1, 5, 10, 20, 30, and 60 minutes.  
     
     
         11 . The apparatus of  claim 1 , said source comprising an incandescent lamp.  
     
     
         12 . The apparatus of  claim 1 , said source comprising at least one light emitting diode.  
     
     
         13 . The apparatus of  claim 1 , further comprising a reflector for reflecting light from said source toward said sample site.  
     
     
         14 . The apparatus of  claim 1 , wherein skin temperature is measured spectrally using an acquired spectrum and multivariate analysis.  
     
     
         15 . The apparatus of  claim 1 , further comprising: 
 an optical coating on at least one of said first optic and said second optic, wherein said optical coating comprises any of:    an antireflection coating;    a longpass filter; and    a shortpass filter.    
     
     
         16 . The apparatus of  claim 1 , further comprising: 
 an aperture defined at a sample module/sample site interface providing an optical opening of between about 1.2 and 5 millimeters.    
     
     
         17 . The apparatus of  claim 7 , further comprising: 
 means for enhancing equilibration in glucose concentration between said sample site and finger blood glucose concentration.    
     
     
         18 . The apparatus of  claim 1 , further comprising: 
 means for automated delivery of a coupling fluid to said sample site prior to sampling.    
     
     
         19 . The apparatus of  claim 1 , further comprising: 
 an optical collection fiber inserted into an aperture formed in said second optic.    
     
     
         20 . The apparatus of  claim 1 , further comprising: 
 means for optically detecting contact of said sample module with said sample site.    
     
     
         21 . The apparatus of  claim 1 , further comprising: 
 a user wearable power/control module coupled to said source.    
     
     
         22 . The apparatus of  claim 1 , wherein said sample module protrudes less than two centimeters from said sample site.  
     
     
         23 . The apparatus of  claim 1 , wherein said base module is coupled directly to said sample module, with said communication bundle forming an integral part thereof.  
     
     
         24 . The apparatus of  claim 1 , said sample module further comprising: 
 a Fabry-Perot interferometer.    
     
     
         25 . The apparatus of  claim 1 , further comprising: 
 means for performing an indirect determination of glucose concentration from sample constituents which comprise any of:    fat, protein, and water;    wherein said sample constituents are distributed as a function of depth in a sample.    
     
     
         26 . The apparatus of  claim 1 , further comprising: 
 means for measuring a reference spectrum and a wavelength standardization spectrum through spectroscopic measurement of a minimally absorbing substance and a material with known and immutable spectral absorbance bands.    
     
     
         27 . The apparatus of  claim 1 , said base module further comprising: 
 means for calibrating to an individual or a group of individuals based upon a calibration data set comprised of paired data points of processed spectral measurements and reference biological parameter values.    
     
     
         28 . The apparatus of  claim 1 , further comprising: 
 a docking station with which said base module is integrally connected, said docking station comprising a computer and an analyte property management center;    wherein said analyte property management center keeps track of events occurring over time.    
     
     
         29 . The apparatus of  claim 1 , further comprising: 
 means for taking any of continuous and semi-continuous measurements when said sample module is in proximate contact with said sample site.    
     
     
         30 . A method for noninvasive measurement of an analyte property using near-infrared spectroscopy, comprising the steps of: 
 providing an analyzer for collecting a near-infrared spectrum of a human tissue sample site; and    estimating said analyte property through application of a multivariate calibration model on said spectrum,    the step of providing said analyzer comprising the steps of: 
 providing a sample module;  
 providing a base module that is physically separated from said sample module;  
 providing a communication bundle for coupling said base module to said sample module;  
 providing a source located in at least one of said base module and said sample module;  
 providing a first optic located in an optical train after said source, for removing heat energy from said optical train; and  
 providing a second optic located in said optical train after said first optic and before a sample site.