A trapezoidal-wave electromagnetic blood flowmeter

Abstract

A new, electromagnetic blood flowmeter is described which has been designed to provide the physiologist with a reliable instrument allowing the measurement of blood flow in the unbroken blood vessel. The transducer has been made small enough to allow implantation in the animal for relatively long periods of time. In this way the flow in a number of vessels can be measured simultaneously in the unanesthetized animal. This flowmeter is different from existing flowmeters because of the unique trapezoidal-wave current that energizes the magnet. A method for calibrating the instrument is described and data is presented showing the femoral artery flow in response to epinephrine and norepinephrine, and hepatic artery flow in response to norepinephrine. Note: (With the Engineering Assistance of Paul Salz) Submitted on January 16, 1961