Microgravity: an ideal environment for cardiac force measuring

In the article main principles of ballistocardiography are considered. Special attention is paid to registration of the spatial ballistocardiogramm. There exist two principles of ballistocardiography: dynamic and seismic. In the event of dynamic ballistocardiography body displacements align to an extent with shifting of the general center of body gravity. Ideal conditions for ballistocardiogram acquisition could be reached if rigidity of internal body relations had an infinitely large value, while rigidity of external relations was nearing the zero. Then displacements of the entire body would depend only on the forces imparted by the cardiovascular system. Microgravity is the only environment providing these ideal conditions for ballistocardiography. Microgravity allows effective application of the dynamic BCG principle to recording pulse-induced body movements corresponding to the center of mass displacements. This kindled interest of the first researchers in space medicine in ballistocardiographic investigations during space flight...