An Approach to a Multiple Channel Oximetry System

Monitoring the oxygen saturation is a standard procedure during surgical intervention and on intensive care units. A common way is to measure the arterial saturation at various locations such as the finger or the forehead. Cardio vascular interventions such as coronary bypass surgery require additional monitoring of the cerebral oxygenation. Commercial devices are bulky and allow for processing one measurement parameter only. The multiple channel oximetry system introduced here has the ability to non-invasively measure and process both the arterial and the cerebral oxygen saturation. It is an optical method that utilizes absorption of light at specific wavelength emitted by LEDs. The present work introduces such a device as well as two different sensor positions for the arterial saturation. Here the signal quality in terms of SNR is compared at the different locations. Heart of this device is an embedded smart phone processor which allows for both driving the LED circuit and processing data.