APPARATUS AND METHOD FOR CONTINUOUSLY MONITORING CARDIAC OUTPUT.

摘要

process and apparatus for continuous monitoring of cardiac output based on the phase difference between an input signal and a temperature signal indicating the temperature of blood leaving the heart. according to a preferred embodiment of a cardiac output monitoring system (10), a catheter (14) is provided with a resistance heater (22).an electrical current having a sinusoidal period between 30 and 60 seconds, is applied to the heating device, so that the energy is dissipated in the blood within the heart of a patient (12). a temperature sensor (24) attached to the catheter, and produces a signal indicating the temperature of blood leaving the heart.the temperature signal and the signal corresponding to the electrical power dissipated in the heating device are filtered at a frequency omega corresponding to the frequency of electric current is applied. the amplitude of the input power, the amplitude of the temperature signal, and the phase difference is used to calculate the heart rate.