Smart ballistocardiography front-end
Résumé
Ballistocardiography (BCG), a contactless heart rate monitoring method, has the potential to measure vital signs and reduce neonates' monitoring pain and discomfort. It uses an accelerometer on the mattress side. As the signal amplitude is very low, the front-end circuit needs a high amplifier gain and thus is very sensitive to baseline wander and noise. However, the usual analogue baseline wander filters are slow to settle, and the individual plus the bed are a damping system which generates noise at its resonance frequency. Consequently, the BCG signal is likely to saturate for several seconds every time the individual moves. This paper introduces a novel smart BCG front-end which identifies the system resonance frequency, filters the baseline wander and the damping noise, and highly amplifies the BCG signal without saturation after patient movement. It has been successfully tested on an experimental model and opens possibilities for medical, real-time and low-cost applications.