MEDICAL TEST DEVICE AND METHOD FOR THE OPTICAL DETERMINATION OF AN ANALYTE COMPRISING MEANS FOR COMPENSATING THE AMBIENT LIGHT BACKGROUND

摘要

The invention refers to a Medical test device for the optical determination of a medically important analyte in an aqueous fluid sample, particularly in blood, said test device comprising: a light source (5) for irradiating a sample with primary light (4), a signal lightdetector (10) which provides an analogue measurement signal characterizing the intensity of detected light and which is arranged for detection of secondary light (6) resulting from interaction of primary light (4) with the sample, a base lightdetector (13) which provides an analogue base signal characterizing the intensity of detected light and which is arranged for detection of ambient light (9) , which may contain primary light (4) , analyzing means (15) for analyzing the signals created by the signal lightdetector (10) and the base lightdetector (13) in order to determine the presence and/or concentration of the analyte in the sample. In order to compensate for the part of the measurement signal caused by ambient light (9) , which is detected by the signal lightdetector (10) in addition to secondary light (6) , the signal lightdetector (10) and the base lightdetector (13) are connected to a common line (14) , which leads to the analyzing means (15) , in such a way that the analogue signals created by the lightdetectors (10,13) are subtracted from each other resulting in a compensated analogue signal provided to the analyzing means (15).