Pulse wave registration from radial artery using photoplethysmographic method

This pilot study was aimed to investigate the possibilities to use the photoplethysmographic (PPG) method for the pulse wave registration from radial artery. The PPG sensor with different separation distances between light emitting diodes (LED) and photodiode was built. The PPG signal registration was carried out at the locations with two different depths of artery and at the locations without large blood vessels under the sensor. In addition, two different forces were applied on the sensor in order to decrease the blood volume in underlying tissue and lower the pulsations that originates from smaller vessels. As a result, it was found that the artery was possible to locate under the sensor, where the value of DC component is minimal. Furthermore, the pressure has to be applied on sensor and optimal separation distance has to be selected between LED and photodiode for the pulse wave registration from radial artery. Further studies and improvements of the sensor are needed.