1. A method of obtaining physiologic parameter information of an animal or human other than blood pressure from a blood pressure signal indicative of sensed variations in blood pressure of the animal or human, the method comprising the steps of: signal processing, external from the animal or human, the blood pressure signal to develop an amplitude versus time waveform; extracting from the developed amplitude versus time waveform a sequence of selected blood pressure features derived from individual cardiac cycles of the amplitude versus time waveform over a selected time interval; fitting a mathematical model to the extracted sequence of selected blood pressure features to yield a fitted mathematical model; and computing the physiologic parameter information from the fitted mathematical model.