Catheters for measurement of cardiac output and blood flow velocity.

摘要

A catheter introduced into the pulmonary artery for use in measuring cardiac output or blood flow velocity includes temperature sensing device including a temperature sensing element for sensing the temperature of blood in the pulmonary artery diluted by an indicator liquid infused for measurement of cardiac output based on a thermodilution method, and a self-heating thermistor for sensing a signal relating to blood flow velocity near the temperature sensing element, the signal being an equilibrium temperature sensed by the thermistor. The catheter is connected to a cardiac output measurement system adapted to measure cardiac output on the basis of the thermodilution method, measure the blood flow velocity which prevails when the cardiac output is measured, and obtain a parameter which links this blood flow velocity to the cardiac output measured in accordance with the thermodilution method. Once the parameter is found, merely measuring the blood flow velocity enables cardiac output to be determined from the flow velocity and the parameter.