[Theoretical basis for the method of calculating blood-flow volume velocity from hydrogen clearance curves]

Two models: a hemodynamic one where the was out velocity is determined by means of the blood flow intensity alone, and a microcirculation one taking into consideration diffusion processes in tissue as well as architectonics of the vascular bed, gave ground for calculation of interrelationship between the time constant of the clearance curve and the local blood flow velocity. The data obtained showed the necessity of amendment depending on the time constant of the clearance curve when using the hemodynamic model.