Electromagnetic Blood Flow Meter Yielding a Base Line Without Interruption of Flow.

Abstract

The necessity of implanting an occlusion bag to secure a base line at zero flow has been eliminated. This has been accomplished by placing the pick-up electrodes in the magnetic field to eliminate the transformer emf induced in the input lead circuit. As the sleeve is moved parallel to flow axis a point is found at which the a.c. voltage between electrodes vanishes regardless of whether the magnet is on or off. Thus, the baseline is obtained by merely switching off the magnet. The circuit has been improved to a point where the animal can be handled without interference with the recording of blood flow.