Continuous Blood Velocity and Flow Measurements by Intravascular Elutherm Probe

Abstract

A device for measuring the mean blood velocity (by means of a thermal equilibrium method) and the intravascular electrical impedance, which determines the mean sectional area of the vessel, have been mounted on the same probe (french catheter 7F). The validity, of the method has been confirmed in vitro and by 100 measurements carried out in dogs and compared with flow measurements by means of the cardio-green method. The correlation coefficient is found to be 0.98.

Videodensitometry for Measuring Blood Vessel Diameter

“…However, the accuracy with which the measurement is made has to meet high demands, since the square of the diameter value is involved in the flow calculation (LANTZ 1975). Various intravascular sensors specially designed for determining the diameter of blood vessels have been described in the literature. One of them is based on the principle of electric impedance and measures the mean cross sectional area in the vessel (CONSTANTINESCO & MERLE 1977), while another operates on the electromagnetic induction principle (KOLIN & MACALPIN 1977).…”