Method and arrangement for determining indicator dilution curves of an indicator in a bloodstream and cardiac parameters

摘要

A method and an arrangement for determining indicator dilution curves and cardiac parameters of a human or animal body having a central bloodstream comprising an indicator periodically passing one or more locations of the body. An ultrasound signal is applied to the indicator in the central bloodstream and ultrasound measurements are taken from a return signal in response to the ultrasound signal, of at least a first cycle of the indicator. From the ultrasound measurements an indicator concentration time signal is determined. The indicator is of such a low concentration that there is a descriptive relation between the measurements and the indicator concentration time signal. From the first cycle of the indicator concentration time signal an indicator dilution curve is modelled and the modelled indicator dilution curve is adjusted over a time interval. The time interval corresponds to at least part of the first cycle leading a further cycle of the indicator. Cardiac parameters are determined from a plurality of modelled indicator dilution curves obtained from a plurality of locations in the central bloodstream of the body.