Layered spectroscopic sample element with microporous membrane

Abstract

A spectroscopic sample holder comprises a microporous sheet. The microporous sheet has a top surface, a bottom surface substantially parallel to the top surface, and at least one side surface oriented substantially perpendicular to the top and bottom surfaces. The side surface forms an exposed transit opening configured to contact a material sample and distribute the contacted material sample into the microporous sheet. The spectroscopic sample holder further comprises a first planar support member positioned on, and substantially parallel to, the top surface of the microporous sheet. The spectroscopic sample holder further comprises a second planar support member positioned on the bottom surface of the microporous sheet, and oriented substantially parallel to the first planar support member.

1 - 137 . (canceled)  
   
   
       138 . An analyte detection system for determining the concentration of analyte in a biological fluid sample drawn from a patient, the system comprising: 
 a near patient optical detection system comprising: 
 a source configured to emit electromagnetic radiation, and  
 a detector positioned in an optical path of the radiation;  
   a sample element configured for removable engagement with the optical detection system, the sample element comprising: 
 a sample cell configured to hold the biological fluid sample, the sample cell being located in the optical path upon engagement of the sample cell with the optical detection system, the sample cell being defined by at least one window which is highly transmissive of infrared radiation, and  
 a sample supply passage extending from and in fluid communication with the sample cell; and  
   a sample extractor comprising a skin-piercing member, the skin piercing member having a passageway that connects a distal portion of the skin-piercing structure with the sample supply passage of the sample element;    whereby the detection system performs optical analysis on the biological fluid sample to assess the concentration of at least one constituent of the biological fluid sample.    
   
   
       139 . The system of  claim 138 , further comprising a filter positioned in the sample supply passage, the filter configured to filter the biological fluid sample passing therethrough.  
   
   
       140 . The system of  claim 138 , further comprising a microporous sheet situated in the optical path, wherein the microporous sheet is positioned within the sample cell.  
   
   
       141 . The system of  claim 138 , further comprising information bearing media disposed on an outer surface of the sample cell.  
   
   
       142 . The system of  claim 138 , wherein at least a portion of the sample cell has an average baseline transmittance of at least about 1 percent.  
   
   
       143 . The system of  claim 138 , wherein at least a portion of the sample cell has an average baseline transmittance of at least about 50 percent.  
   
   
       144 . The system of  claim 138 , wherein the sample cell has a thickness between about 2.5 μm and about 25 μm.  
   
   
       145 . The system of  claim 138 , wherein at least a portion of the sample cell has a transmittance variability of less than about 25 percent.  
   
   
       146 . The system of  claim 138 , wherein at least a portion of the sample cell has a transmittance variability of less than about 10 percent.  
   
   
       147 . The system of  claim 138 , wherein a non-solid material having a network of voids through which the biological fluid sample can propagate is positioned within the sample cell.  
   
   
       148 . An analyte detection system for determining the concentration of analyte in a biological fluid sample drawn from a patient, the system comprising: 
 a source configured to emit electromagnetic radiation;    a detector positioned to receive at least a portion of the electromagnetic radiation emitted from the source;    a sample element configured to hold the biological fluid sample in a sample cell that is defined by a window, wherein the window is highly transmissive of infrared radiation;    a sample supply passage extending from a skin-piercing structure to the sample cell; and    a filter positioned in the sample supply passage to filter the biological fluid sample;    wherein the detection system performs optical analysis on the biological fluid sample to assess the concentration of at least one constituent of the biological fluid sample.    
   
   
       149 . The system of  claim 148 , further comprising a microporous sheet positioned in the sample cell.  
   
   
       150 . The system of  claim 149 , wherein the microporous sheet comprises a non-solid material having a network of voids through which the biological fluid sample can propagate.  
   
   
       151 . The system of  claim 149 , wherein the microporous sheet has a void volume of greater than about 20%.  
   
   
       152 . The system of  claim 149 , wherein the microporous sheet has an average baseline transmittance of at least about 1 percent.  
   
   
       153 . The system of  claim 148 , wherein the sample element is configured to be removably positioned within an optical path extending from the source to the detector.  
   
   
       154 . The system of  claim 148 , wherein the sample cell is reagentless.  
   
   
       155 . The system of  claim 148 , wherein the skin-piercing structure forms a part of the sample element.  
   
   
       156 . The system of  claim 148 , further comprising an optical filtering system that allows at least one wavelength between about 3.5 μm and about 14 μm to pass through the sample cell.  
   
   
       157 . The system of  claim 148 , further comprising information bearing media positioned on an exterior surface of the sample element.  
   
   
       158 . The system of  claim 148 , wherein the sample element has a transmittance variability of less than about 25 percent.  
   
   
       159 . The system of  claim 148 , wherein the sample element has a transmittance variability of less than about 10 percent.