1. An instrument that measures the rate of flow (movement of electric charges, gases, liquids), without interruption of the flow, by producing an electromagnetic field in a liquid that creates an interior current, proportional to the actual flow rate, which is detected by two electrodes.
2. A flowmeter that offers no obstruction to liquid flow.

Two coils produce an electromagnetic field in the conductive moving fluid.

The current induced in the liquid, detected by two electrodes, is directly proportional to the rate of flow.

3. A flowmeter in which changes in the flow of blood are measured through impedance to electromagnetic lines of force that are introduced across a stream of blood.

It has the great advantage that an intact blood vessel can be used.