Adaptive Filter for the Removal of Baseline Wander and Detection of Pulse Event in Wrist Pulse Acquisition using Piezoresistive Pressure Sensors

In this paper, we report an interesting finding of the adaptive filter characteristic that aids in the accurate detection of the pulse event information. Accurate pulse detection is extremely critical as it provides sufficient cardia information. This will further enhance the chances of wearable cardiac activity monitors. The signal is acquired using the using MPVZ5004G6U piezo-resistive (PZR) sensors from the wrist of humans. The signal conditioning is performed and an adaptive FIR filter that uses the least mean squared (LMS) algorithm is designed and deployed for the system identification application. Upon careful examination of the experimental results, the error signal is found to provide the pulse event information. This is due to the sudden change in the pulse activity that causes the error signal to exhibit impulse train like characteristics. The baseline wander and low frequency motion artifacts are alleviated from the signal. The study is conduced using the LabVIEW Virtual Instruments(VI).