[Biomedical technique in physiology (author's transl)].

On the basis of two examples of projects being realized in the department of physiology in Graz the use of engineering methods in physiological research is demonstrated. The first example presents a survey of the use of system-theoretical methods for the investigation of overall regulation of circulation under working conditions. Using two test-signals (impulse input, random input) for experimental identification, the impulse response of heart-rate to changes in work load was obtained. The impulse responses of the volunteers were then characterized by a set of three parameters, allowing statistical evaluation, classification for diagnostic means and verification of hypotheses. The second example deals with an investigation of the signal structure of ultrasound-CW-Doppler-systems. Basing on the general Doppler-principle, which is already in use in angiology it was tried to quantify the determinants of the audio-signal, describing it by statistical functions and by experiments on simple models (tube-models). The goal of the experiments is a quantitative assessment of volume-flow and an enhancement of information about the scattering medium (rheological properties of blood).