Signal transmission for implantable medical devices using figure-of-eight coils

A new skin-transparent signal transmission method is proposed. For applications on high energy-consumption medical devices such as total artificial hearts or implantable FES (Functional Electrical Stimulation) systems, we constructed a transcutaneous signal transmission system using figure-of-eight coils, as it is apparent that these applications need feedback and/or controlling signals for stable and safe opration. By employing figure-of-eight coils, we could reduce noise coming from around the coil and still suppress noise emitted from the transmitting coil. In the animal experiment using a goat, we could successfully observe the fluctuation in the amount of the transmitted energy through skin with figure-of-eight coils of 30mm in diameter. Meanwhile, figure-of-eight coils didn't cause any unfavorble interferances with the electromagnetically driven ventricular assist device connected to the goat's heart at the time.