APPARTUS FOR DETERMINING FLOW RATE AND VELOCITY RATIO OF BLOOD

摘要

An appartus for determining flow rate and velocity ratio comprises a catherter and four thermocouples, which are located adjacent the exterior of said catheter. The catheter is placed in an artery or a vein. When 5% dextrose solution at 0~5°C is injected through the end pore or the side pore of the catheter, the blood-injectate mixture at lower temperature flows over successively four points each of which has a thermocouple. To select two points from the four. Instantaneous flow rate A and B of the two points can be calculated by means of the known distance between said two points and the time spend by the blood-injectate mixture flowing over the two points, then instantaneous velocity ratio also can be obtained according to the instantaneous flow rate A and B.