Single-Coil Coreless Electromagnetic Blood-Flow Meters

Abstract
The development of coreless implantable electromagnetic flow probes is reviewed. It is pointed out that their effectiveness demonstrates strict homogeneity of the magnetic field as not being an essential requirement for an electromagnetic blood-flow probe. The flow probe design is reduced to maximum simplicity by relying on one single bent coil for generation of the magnetic field. The single-coil design permits a very wide opening for the introduction of the artery affording with greater simplicity convenience offered by hinged flow probes. The manufacturing time is greatly reduced as compared to previous probe designs and performance is greatly improved. Platinized platinum electrodes reduce the noise level and the "zero error." A reliable base line can be obtained by switching off the magnet even after prolonged implantation in the course of chronic experiments.