[New trends in ballistocardiography].

Balistocardiography is a method by which body vibrations caused by heart activity are registered. Evolution during the past fifty years to the present is described. Balistocardiography (BCG) represented by instruments of different natural frequencies and damping should bring information about cardiac output. This expectation was not fulfilled due to the unsuitable physical properties of apparatuses. Quantitative balistocardiography (Q-BCG) was based on the exact physical properties of the newly-developed apparatuses, force acting and force registered were exactly measured and expressed in units of force in Newtons. Quantitative seismography (Q-SCG) opens a new field of cardiovascular dynamics examination. Force applied is registered without amplitude, phase or time distortion. Using this absolutely non-invasive method, a new field of monitoring heart rate variability was opened up. Systolic force as well as heart rate variability in relation to changes in external stimuli are registered. Quantitative seismocardiography probably offers a more complex view of both inotropic and chronotropic heart functions. It will be suitable for: examining operators exposed to stress; for assessing the effect of work, fatigue and mental stress; for monitoring persons as part of disease prevention; for determining a person's ability to carry out their duties both on the ground and in the air.