A non-invasive subtle pulse rate extraction method based on Eulerian video magnification

Measuring pulse rate by means of video recording of the wrist area is a non-invasive approach. Eulerian Video Linear Magnification (EVLM) is used in this paper to magnify, and make visible, subtle pulse-induced wrist motions. A series of experiments are conducted to investigate the performance of ELVM under various conditions, such as light intensity, background colour and a set of video recording parameters. The results show that a light intensity of around 224 to 229 lx is optimal; excess or inadequate light significantly impairs the success of amplifying the skin movement resulting from the pulse. It is demonstrated that a white background colour enables both the radial and ulnar areas to be clearly visible in the recorded video, thus improving pulse measurement. In addition, it is shown that a female’s pulse strength is approximately 40 % weaker than that of a male averaged over the participants