Pulse oximeter for determining physiological variables in e.g. finger tissue, has comparison device determining current of photo detector and radiation source for determining measured variable transmission quantity

摘要

The device has a sensor with a radiation source operated by an electric current. The source determines the radiation of two different wavelengths and delivers to the tissue. A photo detector receives the radiation that is damped and/or transmitted through the tissue and converts the radiation into an electric current signal. A comparison device is connected with the radiation source and the photo detector. The comparison device determines the current of the detector and the source for determining a measured variable transmission. An independent claim is also included for a method of determining physiological variables in a tissue supplied with blood.