| abstract |
A spectroscopic apparatus, a method of determining a concentration and/or spatial gradient of an analyte of a bodily fluid and a corresponding computer program product are provided. The spectroscopic apparatus provides determination of a position of a capillary vessel ( 104 ) within a biological sample in order to focus spectroscopic excitation radiation to a volume ( 122 ). that is in close proximity to the capillary vessel but does not overlap with the capillary vessel. The provided apparatus, method, and computer program product advantageously exploit the permeability of the vessel wall with respect to an analyte that is subject to analyte concentration determination. By means of biological transport processes, the concentration of an analyte of a bodily fluid located in the capillary vessel influences the concentration in the surrounding of the capillary vessel. Spectroscopic analysis of a volume outside the capillary vessel can therefore serve for a precise and reliable analyte concentration determination inside the capillary vessel. |