[Chronobiological aspects of artificial total heart replacement in long-term animal experiments--a systemanalytic...

Biological rhythms (circadian rhythms) have been observed in the hemodynamics of experimental animals (calves). After artificial total heart replacement these rhythms are typically altered compared to control animals. These observations induce a growing consideration of chronobiological aspects in a systemanalysis for the conception of an automatic external control of the artificial heart, which has to be divided in:--parameter-progression (tendencies), --parameter-variation (discrete, oscillations), --parameter-coupling (phase shifts).