Robust ballistocardiogram acquisition for home monitoring

Abstract

The ballistocardiogram (BCG) measures the reaction of the body to cardiac ejection forces, and is an effective, non-invasive means of evaluating cardiovascular function. A simple, robust method is presented for acquiring high-quality, repeatable BCG signals from a modified, commercially available scale. The measured BCG waveforms for all subjects qualitatively matched values in the existing literature and physiologic expectations in terms of timing and IJ amplitude. Additionally, the BCG IJ amplitude was shown to be correlated with diastolic filling time for a subject with premature atrial contractions, demonstrating the sensitivity of the apparatus to beat-by-beat hemodynamic changes. The signal-to-noise ratio (SNR) of the BCG was estimated using two methods, and the average SNR over all subjects was greater than 12 for both estimates. The BCG measurement was shown to be repeatable over 50 recordings taken from the same subject over a three week period. This approach could allow patients at home to monitor trends in cardiovascular health.

Evaluation of respiratory- and postural-induced changes on the ballistocardiogram signal by time warping averaging

“…The prolongation of the RJ interval during Valsalva, which could be explained as a consequence of the decreased venous return during the strain, was already reported in the literature (Inan et al 2008). However, this decrease in venous return was not visible in terms of amplitudes, in contrast to the reduced values of A IJ reported in Inan et al (2009).…”

“…weight scales, bed, chair). In particular, the RJ interval has been proposed as a surrogate for the pre-ejection period (PEP) (Inan et al 2009, Etemadi et al 2011, Javaid et al 2016, a non-invasive indirect measurement of cardiac contractility (Lewis et al 1977), and, combined with photoplethysmography (PPG), both I and J time occurrences have been shown to be an accurate estimate of arterial stiffening (Wiard 2012).…”

Fiber-optic sensors for monitoring patient physiological parameters: a review of applicable technologies and relevance to use during magnetic resonance imaging procedures

“…The signal was obtained by the superposition of several sine functions whose amplitudes and periods were chosen so that the resultant signal shape was similar to a ballistocardiogram. 176,177 In other words, the BCG signal expressed in microstrains with a 4-με amplitude and 1-s period (60 bpm) is presented in the upper graph. The middle graph shows the strain-induced Bragg wavelength shifts of the FBG peak synchronized with the strain changes.…”

Impact of the Mechanical Interface on BCG Signals obtained from Electronic Weighing Scales

“…Further, it was observed there that different weighing scales yielded different BCG waveforms for the same subject, albeit this was irrelevant for heart rate monitoring [2]. Unfortunately, these results went mostly unnoticed during later characterizations of weighing scales intended for BCG monitoring [7], which concluded that the measured waveform was not mechanically distorted as the resonant frequency of scales was significantly out of band. This view, in which the mechanic response of the weighing scale is considered not to distort the BCG signal, has been sustained until now [1,8].…”