Stimulation of nerves and muscles using large pulsed magnetic fields

It has been known since the work of Galvani and Volta in the 1790s that nerves and muscles can be electrically stimulated. The technique of electrical stimulation, using either needle or surface electrodes to inject current into the tissue, is today widely used in medicine both for diagnostic purposes and for other applications such as cardiac pacing, defibrillation of the heart and to aid gait. It does, however, have some disadvantages and limitations, in particular the need to use needle electrodes to stimulate deep nerves, its relative inability to stimulate structures surrounded by bone such as the human brain and the discomfort it causes. Over 2000 magnetic stimulators are now in use world-wide for both clinical and research applications. The technique has become established as a diagnostic tool in neurology and the recent emergence of a number of potential therapeutic applications suggests that the use of magnetic stimulation in medicine is likely to grow.