Physical basis of ballistocardiography. V: The distortion of the ballistocardiogram caused by the movement of the heart inside the body

Abstract

The influence of the binding between heart and skeleton and between skeleton and ballistocardiograph upon the representation of the human ballistocardiogram has been treated quantitatively for the low-frequency and the high-frequency ballistocardiograph.

It appeared that frequencies close to the frequency of the heart are more distorted when a high-frequency ballistocardiograph is used than when the low-frequency ballistocardiograph is the recording instrument. This is caused by the compliance between subject and ballistocardiograph as well as by that between the latter and the surroundings.