A Real-Time Heart-Rate Estimator from Steel Textile ECG Sensors in a Wireless Vital Wearing System

This paper presents a real-time heart-rate estimator using the ECG data which are received via wireless bluetooth receiver and measured with wearable electrodes made of steel textile in a wearing system. The measured ECG signals, because of the movable electrodes and the resulting unfixed contacts, demonstrate high baseline wandering phenomena and high noisy aberrations especially when the wearing person is in motion, making the heart-rate estimation a sophisticated work. To conquer this problem, the presented heart- rate estimator first uses the subspace technique to remove the baseline wandering in ECG signals, and then applies the adaptive notch filter (ANF) technique to obtain the heart- rate estimate. Experiments for ECG data from the person with initially sitting still through walking steadily to jogging, demonstrate that the presented method obtains heart- rate estimates which satisfactorily reflect the motion status of the person. The vital system embedded with the capability of real-time heart-rate estimation makes it highly suitable for applications of remote healthcare and wellness.