Ballistocardiography and seismocardiography: a review of recent advances.

In the past decade, there has been a resurgence in the field of unobtrusive cardiomechanical assessment, through advancing methods for measuring and interpreting ballistocardiogram (BCG) and seismocardiogram (SCG) signals. Novel instrumentation solutions have enabled BCG and SCG measurement outside of clinical settings, in the home, in the field, and even in microgravity. Customized signal processing algorithms have led to reduced measurement noise, clinically relevant feature extraction, and signal modeling. Finally, human subjects physiology studies have been conducted using these novel instruments and signal processing tools with promising results. This paper reviews the recent advances in these areas of modern BCG and SCG research.

Multi-signal bathroom scale to assess long-term trends in cardiovascular parameters.

This paper describes the circuits and signal processing techniques that convert an electronic bathroom scale intended for bioimpedance analysis (BIA) into a compact system to acquire the electrocardiogram (ECG), the ballistocardiogram (BCG), and the impedance plethysmogram (IPG) using only plantar measurements. The signal processing methods proposed rely on the higher quality of the IPG as compared to the ECG and BCG and they enhance the signal-to-noise ratio (SNR) of these two signals, which otherwise could be too poor in non-controlled environments. The system is suitable for long-term periodic monitoring of cardiovascular function.

Heart and respiratory rate detection on a bathroom scale based on the ballistocardiogram and the continuous wavelet transform.

Ballistocardiography is a non-invasive technique that yields information about the cardiovascular system that is not available in other external signals such as the electrocardiogram (ECG). In the last years, several research groups have obtained the ballistocardiogram (BCG) by using instrumentation methods simpler than those available in the 1950s and that did not progress because of their complexity as compared to ultrasound and other noninvasive techniques that are in common use nowadays. We describe a novel method for real-time robust heart- (HR) and respiratory- (RR) rate detection from a subject that stands on a common electronic bathroom scale. BCG signals from the scale are wirelessly sent to a PC where algorithms based on the continuous wavelet transform (CWT) extract the HR and the RR. HR results are compared to those obtained from the ECG. To better assess the RR results, subjects have been asked to synchronize their breathing rate to an on-screen bar-graph set at a constant rate of breaths per minute. This method to obtain the heart and respiratory rates is simple, compact, non-invasive and passive, and can be applied to any person able to stand on an electronic weighing scale, even if wearing shoes.