Editorial: Cardiac Vibration Signals: Old Techniques, New Tricks, and Applications

Every heartbeat sets the body into a series of vibrations that can be recorded using transducers placed on the surface of the body, such as wearables, or the surfaces that are in contact with the body, such as chairs, beds, or weight scales. These vibrations have been studied for more than a century and the corresponding signals have been given different names depending on the method of recording and the sensor placement. Currently, Phonocardiography (PCG), Ballistocardiography (BCG), and Seismocardiography (SCG) are the signals most commonly considered in this area, although other signals or signal combinations may also be considered. Since the start of the new millennium, there has been a particular burst in the research on these signals, in part triggered by the recent advances in the sensor miniaturization and signal processing techniques. In some instances, these signals have even been integrated into medical devices. However, a lot of work is still needed to improve recording and analysis of these signals, fully understand the genesis of their waveforms, and verify their applicability in the clinical practice. The goal of this article Research Topic is to bring together new research ideas on each of these challenges.