PPG Based Heart Rate Algorithm Improvement with Butterworth IIR Filter and Savitzky-Golay FIR Filter

摘要

Heart Rate is an important physiological parameter for health monitoring. Heart Rate Measurement with smart phone is used by many people all over the world and different applications are developed. Mobile camera detects Electro Magnetic radiation at 350-1000nm wavelengths & in that wavelength range, 700-1000nm is IR radiation. Infrared is a special form of invisible electromagnetic wave that can be felt by heat. Visible light's wavelength is 400-700nm. Here in our study, we have focused on Non-Invasive PPG signal based HeartRate monitoringfrom skin blood flow using IR light at 900 nm wavelength. The PPG is obtained from RED channel of the captured live video of smart phone camera as RED channel video is stable than Green & Blue channel. We have captured contact red videoto obtain PPG using smart phone and developed algorithm to remove some percentoftouch errors and followed by smoothening with Savitzky-Golay FIR filter, noise reduction with 2nd Order Butterworth (IIR) band pass filter, leakage reduction with Hanning window and FFT analysis of noise free smooth PPG signal.