| 摘要 |
<p>A method of determining the concentration of a component from the intensity of electromagnetic waves with at least two selected wavelengths which are reflected by human tissue or transmitted through human tissue comprises the step of converting first intensities of the received electromagnetic waves into at least one first and one second electric signal (L1ÄiÜ; L2ÄiÜ). Following this, a continuous first temporal average value (L1avgÄiÜ) of the first signal and a continuous second temporal average value (L2avgÄiÜ) of the second signal are formed. A first alternating component (AC1ÄiÜ) is continuously determined from said first signal and said first average value, whereas a second alternating component (AC2ÄiÜ) is continuously determined from said second signal and said second average value. Subsequently, a continuous ratio (RÄiÜ) is determined from said first and second signals as well as from said first and second continuous temporal average values, with the exception of regions lying close to the zero passages of the alternating components (AC1ÄiÜ, AC2ÄiÜ). Finally, the concentration of the component is derived from said continuous ratio (RÄiÜ) or from the integrated ratio (R(T/2)) derived from the integrated alternating components (AC1(T/2), AC2(T/2)). <IMAGE></p> |
