Permanent artificial hearts are being developed that are electrically powered. Wireless techniques are used to transmit the electrical energy across the body wall using the principle of:

B. Inductive coupling

DISCUSSION: Electrical energy can be transmitted across the body wall by tunnelling an electric wire; however, experience has shown that infection, starting at the skin line and burrowing deeper into the body, will occur over time. This infection can be delayed, but not stopped, by the use of a velour covering on the wire. Wireless electrical energy transmission was first used in clinical surgery by W.W.L. Glenn in the 1950s for powering pacemakers. The remarkable advances in electronics have facilitated this technique; however, the placement of the two coils parallel to one another (with the skin between), as opposed to interlocking as in an industrial transformer, reduces the efficiency of transmission from approximately 99% to 70%.