Heart rate measurement through PPG
Heartbeat measurement in a wireless headset
J. Guyomard
R. Stortelder
G. De Graaf – Mentor
More Info
expand_more
Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.
Abstract
This thesis, assigned by Plantronics, proposes a solution to the motion artifacts that corrupt the results of PPG (Photo Plethysmo Graphic) signals and therefore the determined heart rate during physical exercises. An Infra-Red light emitting diode and phototransistor package was used to create a PPG signal that was amplified using an operational amplifier and filtered using a high pass and low pass filter. Research was done on PPG signals corrupted by motion with the help of an accelerometer. The fast Fourier transform of the signals showed that there is a relation between the frequency components of the PPG signal and motion signals. Based on this finding a working filter was designed in MATLAB that compares the frequency spectrum of the PPG to motion signals and removes any overlap. The experimental results for running motions prove the correct functioning of this system and showed that invasive sensing techniques are unnecessary.