Ballistocardiography--a method worth revisiting.

The field of ballistocardiography seems to be enjoying a recent resurgence, most notably through the development of novel technologies and signal processing methods for measurement and analysis. After the method almost vanished in the late 80's and 90's, it is reasonable to wonder what is different this time, and if the technique has now more chances of becoming what its pioneer always wanted - a widespread clinical tool. This paper is an effort to compare and contrast this novel wave of research (notably in the context of the authors' own work). It also suggests that the new approaches have several key differences with past embodiments that place them in a good position to address some specific issues such as cardiac resynchronization therapy device optimization or congestive heart failure monitoring. This optimism is largely fed by the recent technological advances enabling the measurement of the BCG unobtrusively, frequently, at home or in a hospital, and by a re-focus on monitoring and trending applications.