Real Time, Non-Invasive Cerebral Blood Oxygenation Monitoring Device

This paper describes the design of a simple, low-cost microcontroller based cerebral blood oxygenation monitoring device. This device is based on a non-invasive sensor that detects the blood oxygenation related to brain function. It is a reflectance based sensor which consists of IR emitter of wavelength 940 nm and ultrared LED 660nm and a detector. By measuring returned light at from the light source, the hemoglobin oxygen saturation in frontal cortex can be determined. Oxygen saturation is an indicator of oxygen transport in the body. Cerebral or regional oxygen saturation [1] is commonly termed as rSO2. There are different methods to monitor cerebral blood flow. One of them which has been recently introduced is measurement of cerebral oxygen saturation (rSO2) with cerebral oximetry, which is noninvasive [9] and easy to use. Since it measures mostly venous blood oxygen saturation and does not require pulsatile signal, it can be used as a measure of global perfusion during cardiac surgery [1].