The first evidence that electrical changes can cause muscles to contract was p- vided by Galvani (1791). Galvani s ideas about animal electricity were explored during the 19th and 20th century when it was firmly established that electricity is one of the most important mechanisms used for communication by the nervous system and muscle. These researches lead to the development of ever more soph- ticated equipment that could either record the electrical changes in nerves and muscles, or elicit functional changes by electrically stimulating these structures. It was indeed the combination of...