Noninvasive ambulatory measurement system of cardiac activity

Abstract

This work implements a noninvasive system that measures the movements caused by cardiac activity. It uses unobtrusive Electro-Mechanical Films (EMFi) on the seat and on the backrest of a regular chair. The system detects ballistocardiogram (BCG) and respiration movements. Real data was obtained from 54 volunteers. 19 of them were measured in the laboratory and 35 in a hospital waiting room. Using a BIOPAC acquisition system, the ECG was measured simultaneously to the BCG for comparison. Wavelet Transform (WT) is a better option than Empirical Mode Decomposition (EMD) for signal extraction and produces higher effective measurement time. In the laboratory, the best results are obtained on the seat. The correlation index was 0.9800 and the Bland-Altman limits of agreement were 0.7136 ± 4.3673 [BPM]. In the hospital waiting room, the best results are also from the seat sensor. The correlation index was 0.9840, and the limits of agreement were 0.4386 ± 3.5884 [BPM]. The system is able to measure BCG in an unobtrusive way and determine the cardiac frequency with high precision. It is simple to use, which means the system can easily be used in non-standard settings: resting in a chair or couch, at the gym, schools or in a hospital waiting room, as shown.

Smart Mat for Respiratory Activity Detection: Study in a Clinical Setting

“…Sadek et al [22] implemented the Maximal Overlap Discrete Wavelet Transform (MODWT) to extract the BCG signal from a microbend FOS. Previous studies [15,18,22] have shown that wavelets and especially MODWT fare better than other algorithms such as clustering and EMD. DWT's strengths rely on its ability to split the signal into multiple levels of frequency components.…”

The Latest Progress and Development Trend in the Research of Ballistocardiography (BCG) and Seismocardiogram (SCG) in the Field of Health Care

“…Part f shows portable device placed on sternum reading simultaneously ECG and BCG signals during the flight [35]. BCG/SCG can be used in different application scenarios, such as a ward [36], a hospital waiting room [37], a MRI room [38], or at home [39], for monitoring physical health status. Wearable devices can be carried easily in daily life realizing zero load measurement on human body [40].…”

“…There are many applications of BCG/SCG in cardiac activity analysis, such as diagnosis of cardiovascular diseases [61][62][63][64], monitoring of cardiovascular status of a patient [37,[65][66][67][68][69], and assisting in evaluation of human cardiovascular health level [70][71][72]. It should be noted that ECG, as the golden standard for the means of cardiovascular monitoring, always takes the leading position [73,74], therefore, BCG/SCG research, often with reference of ECG measurement results, assists waveform reference point in signal analysis [75,76].…”

A comparison of three heart rate detection algorithms over ballistocardiogram signals

“…At last, a time-domain peak detection algorithm was used to detect J-peaks. A similar approach was introduced by Pino et al [22], in which BCG signals were acquired from two EMFi sensors embedded in the seat and backrest of a typical chair. Raw sensor data were gathered from 19 subjects in a lab for over 1 min.…”