Pulse oximetry is a diagnostic method which allows continuous non-invasive measurement of the blood oxygen content. The method is based on the light absorption behaviour of hemoglobin, which depends on the oxygen content, and is implemented by measuring the light transmitted by the organ. In general, the problem arises that arterial pulsation and mechanical movement lead to movement artifacts that strongly impair an accurate determination of the blood oxygen content.

The invention requires a measuring device and a signal processing method to compensate motion artifacts in the determination of oxygen saturation and plethysmogram in pulse oximetry. To measure the oxygen saturation of the blood flowing in a peripheral part of the body, electromagnetic radiation is radiated into or through this part of the body in two different wavelength ranges. The reflected or transmitted radiation is then measured to form two measurement signals, which are evaluated using a software method that has also been developed and the oxygen saturation of the blood is determined.