Patent ID: 6103197
Filing Date: 2000-08-15
Classification: G01N

Abstract:
Measuring apparatus for optically determining the total hemoglobin concentration (tHb) in non-hemolyzed whole blood, comprisinga capillary channel for holding a blood sample, having an inner wall and an inner diameter,an excitation device for supplying at least first and second measurement wavelengths, defining a first optical axis directed towards said capillary channel and an excitation light cone defined by an opening angle .alpha.,a detection device, defining a second optical axis directed towards said capillary channel and a detection light cone defined by an acceptance angle,wherein inclination angles .beta..sub.1, .beta..sub.2 of said first and second optical axes and a distance e of said axes at intersection points with said capillary channel are chosen with respect to said diameter of said capillary channel such that said excitation light cone and said detection cone light overlap on said inner wall of said capillay channel if said capillary channel is filled with an aqueous solution, and that they do not overlap if said capillary channel is filled with whole blood, on account of reduced mean penetration depth of first and second measurement wavelengths.