Patent ID: 6203501
Filing Date: 2001-03-20
Classification: A61B

Abstract:
A method for measuring cardiac stroke volume comprising the steps of:(a) supplying power to a heater positioned in the blood flow path through or adjacent to the heart to raise the temperature of the heater above the blood temperature at the selected location;(b) controlling the power supplied in step (a) to maintain the heater temperature at a constant value;(c) producing a signal corresponding to the average value of the instantaneous blood flow velocity over at least one cardiac cycle;(d) obtaining a signal proportional to blood flow over a time period greater than one cardiac cycle;(e) dividing the value obtained in step (d) by the value obtained in step (c); and(f) integrating over a cardiac cycle a value, which is a function of the ratio of power supplied to the heater to the difference between the heater temperature and the blood temperature and multiplying by the value, obtained in step (e).