Method and apparatus for using infrared readings to detect misidentification of a diagnostic test strip in a reflectance spectrometer

Abstract

A method and apparatus for using an infrared reading to detect the misidentification of a diagnostic test strip disposed on a feed table comprising the steps of determining if the test strip possesses specified reagents, reading the infrared reflectances from the reagent positions, determining if the reflectances are within an acceptable predetermined range and aborting the test if the infrared reflectances are not within the acceptable predetermined range.

1 . A reflectance spectroscope, comprising:
 a source of illumination for generating light rays;   a support member adapted to support a reagent pad, said support member having a position in which said reagent pad is illuminated by said light rays generated by said illumination source;   a reflectance detector positioned to receive light rays from said reagent pad, said reflectance detector occupying a detection area;   a housing having an aperture formed therein, said aperture being disposed between said illumination source and said reagent pad and being adapted to cause said light rays generated by said illumination source to illuminate an area of said reagent pad;   means for defining a first optical path from said illumination source to said reagent pad in which substantially all singly-reflected light rays generated by said illumination source are prevented from reaching said reagent pad, said means for defining said first optical path having a non-planar wall comprising:
 a first wall portion with a specular reflective surface disposed to reflect substantially all of said light-rays generated by said illumination source which reach said first wall portion to an area which does not include said aperture; and 
 a second wall portion with a specular reflective surface disposed to reflect substantially all of said light rays generated by said illumination source which reach said second wall portion to an area which does not include said aperture; 
   means for defining a second optical path from said reagent pad to said reflectance detector in which substantially ail singly-reflected light rays from said reagent pad are prevented from reaching said reflectance detector, said means for defining said second optical path having a non-planar wall comprising:
 a third wall portion with a specular reflective surface disposed to reflect substantially all of said light rays which reach said third wall portion from said reagent pad to an area which does not include said detection area; and 
 a fourth wall portion with a specular reflective surface disposed to reflect substantially all of said light rays which reach said fourth wall portion from said reagent pad to an area which does not include said detection area; and 
   means for detecting the misidentification of a diagnostic test strip by determining if said test strip possesses specified reagents, locating the position of said reagents on said test strip and reading the infrared reflectances from the reagent positions to determine if said infrared reflectances are within an acceptable predetermined infrared reflectance range.   
   
   
       2 . The reflectance spectroscope of  claim 1  further comprising the step of aborting said method if said infrared reflectances for one or more of said reagents are not within said predetermined infrared reflectance range. 
   
   
       3 . The reflectance spectroscope as defined in  claim 1  wherein at least one of said wall portions is substantially planar. 
   
   
       4 . The reflectance spectroscope as defined in  claim 1  wherein all of said wall portions are substantially planar. 
   
   
       5 . The reflectance spectroscope as defined in  claim 1  wherein said housing has a detection aperture formed therein, said detection aperture being disposed between said reagent pad and said reflectance detector. 
   
   
       6 . The reflectance spectroscope as defined in  claim 4  wherein said means for defining said second optical path comprises at least one edge defined by a pair of wall portions, said edge being substantially aligned with an edge of said detection area and an edge of said detection aperture. 
   
   
       7 . The reflectance spectroscope as defined in  claim 1  wherein said housing has a first detection aperture formed therein, said first detection aperture having a first edge and a second edge and being disposed between said reagent pad and said reflectance detector so that said edges of said first detection aperture are substantially aligned with a pair of edges of said detection area. 
   
   
       8 . A reflectance spectroscope as defined in  claim 7  wherein said housing has a second detection aperture formed therein, said second detection aperture having a first edge and a second edge and being disposed between said first detection aperture and said reflectance detector so that said edges of said second detection aperture are substantially aligned with said pair of edges of said detection area. 
   
   
       9 . A reflectance spectroscope, comprising:
 a source of illumination for generating light rays;   a support member adapted to support a reagent pad, said support member having a position in which said reagent pad is illuminated by said light rays generated by said illumination source;   a reflectance detector positioned to receive light rays from said reagent pad;   means for defining a first optical path from said illumination source to said reagent pad in which substantially all singly-reflected light rays generated by said illumination source are prevented from reaching said reagent pad; and   means for detecting the misidentification of a diagnostic test strip including a determination whether said test strip possesses specified reagents, locating the position of said reagents on said strip and reading the infrared reflectances front the reagent positions to determine if said infrared reflectances are within an acceptable predetermined infrared reflectance range.   
   
   
       10 . A reflectance spectroscope as defined in  claim 9  additionally comprising a housing having an aperture formed therein, said aperture being disposed between said illumination source and said reagent pad and being adapted to cause said light rays generated by said illumination source to illuminate an area of said reagent pad. 
   
   
       11 . A reflectance spectroscope as defined in  claim 10  wherein said means for defining a first optical path has a non-planar wall portion comprising:
 a first wall portion with a specular reflective surface disposed to reflect substantially all of said light rays generated by said illumination source which reach said first wall portion to an area which does not include said aperture; and   a second wall portion with a specular reflective surface disposed to reflect substantially all of said light rays generated by said illumination source which reach said a second wall portion to an area which does not include said aperture.   
   
   
       12 . A reflectance spectroscope as defined in  claim 11  wherein at least one of said first and second wail portions is substantially planar. 
   
   
       13 . A reflectance spectroscope as defined in  claim 9  additionally comprising means for defining a second optical path from said reagent pad to said reflectance detector in which substantially all singly-reflected light rays from said reagent pad are prevented from reaching said reflectance detector. 
   
   
       14 . A reflectance spectroscope as defined in  claim 13  wherein said reflectance detector occupies a detection area and wherein said reflectance spectroscope additionally comprises a housing. 
   
   
       15 . A reflectance spectroscope as defined in  claim 14  wherein said means for defining a second optical path has a non-planar wall portion comprising:
 a first wall portion with a specular reflective surface disposed to reflect substantially all of said light rays which reach said first wall portion from said reagent pad to an area which does not include said detection area; and   a second wail portion with a specular reflective surface disposed to reflect substantially all of said light rays which reach said second wall portion from said reagent pad to an area which does not include said detection area.