Proposal of a Cheap Pulse Wave Velocity (PWV) Meter Using Photoplethysmography

When heart pumps oxygenated blood through artery, the arterial pulse spreads the whole body through arterial tree. The rate of this pulse is the pulse rate, which is around 70 per minute. The speed at which this pulse spreads over the arterial tree is an important index to measure the stiffness of the arterial wall, which becomes stiffer as the body ages. Faster the pulse wave moves, stiffer is the artery wall. Thus, Pulse Wave Velocity (PWV) is a measure of the artery wall stiffness. In this work, we propose a cheap device to measure PWV, using Photoplethysmography sensors. Pulse wave signals, from two locations of the body, were collected, transferred to a tablet using blue-tooth communication, and analyzed. Accurate delay measurement of the pulse wave, collected at two different points, is necessary for the accuracy of PWV measurement. Through experiments, on different subjects, we have shown that the proposed system could measure PWV accurately.