Patent ID: 6963767
Filing Date: 2005-11-08
Classification: A61B

Abstract:
1. A method for detecting the validity of measurement circumstances in connection with a monitoring device intended for determining the amount of at least one light absorbing substance in a subject, the monitoring device comprising emitters for emitting radiation at a minimum of two wavelengths, driving means for activating said emitters, and a detector for receiving said radiation at said wavelengths and for producing an electrical signal in response to the radiation, the method comprising the steps of: providing a drive signal to an emitter, the drive signal traveling in a direction to said emitter and having predetermined characteristics; analyzing an electrical signal, traveling in a direction from a detector, in timed relation to said drive signal in order to detect whether a crosstalk component caused by electric power coupled directly from said drive signal is present in said electrical signal, said crosstalk component resulting from at least one of capacitive, inductive and resistive power coupling from said drive signal to said electrical signal; and, taking predetermined measures when said crosstalk component is detected.