Contactless nerve stimulation and signal detection by inductive transducer

In an attempt to avoid the undesirable aspects of galvanic nerve stimulation, a toroidal inductive transducer was developed and tested. It was found that a nerve threading the lumen of the toroid could be stimulated by a magnetic field which generated an EMF of 0.7-volts peak amplitude and 50-μs duration in a monitor wire. The stimulation was sufficient to cause contraction of major leg muscles in anesthetised mammals. Some earlier indication that a similar arrangement would allow detection of compound action potentials from nerve has not yet been verified by subsequent experiments. The method and its relation to established theory and procedure is described. An example of a stimulus-pulse generator is given. Possible applications and future plans of study are discussed.