Abstract: The RR series, which is constituted by a plurality of samples respectively defining the time intervals between pairs of successive heart beats, is filtered by means of a digital bandpass filter (Fk) presenting a predefined bandwidth [fc, f?c], and preferably by means of an IIR recursive selective filter, and a variability index (Ik) is computed which is a function of the instantaneous amplitude [vs(n)] of the discrete signal (Sk) from said bandwidth filter. The variability index (Ik) is preferably a function of, and in particular equal to, the effective value of the discrete signal (Sk) from the bandpass filter.

Abstract: The invention provides a pump regulation device. It is characterized in that the device (21) comprises: means for recording the real pressure (24) and a reference pressure, means, on the one hand for comparing the real pressure (24) in the organ and the reference pressure and, on the other hand, for emitting a signal proportional to the error, ports controlling the threshold of this error signal, an alarm controlled by the signal passing through at least one of said ports.