title: A new transcutaneous energy transmission system with hybrid energy coils for driving an implantable biventricular assist device.
abstract: We have developed a new transcutaneous energy transmission (TET) system for a totally implantable biventricular assist device (BVAD) system in the New Energy and Industrial Development Organization (NEDO) artificial heart project. The TET system mainly consists of an energy transmitter, a hybrid energy coil unit, an energy receiver, an internal battery system, and an optical telemetry system. The hybrid energy coil unit consists of an air-core energy transmission coil and an energy-receiving coil having a ferrite core. Internal units of the TET system are encapsulated in a titanium alloy casing, which has a size of 111 mm in width, 73 mm in length, and 25 mm in height. In in vitro experiments, the TET system can transmit a maximum electric energy of 60 Watts, and it has a maximum transmission efficiency of 87.3%. A maximum surface temperature of 46.1 degrees C was measured at the ferrite core of the energy-receiving coil during an energy transmission of 20 Watts in air. The long-term performance test shows that the TET system has been able to operate stably for over 4 years with a decrease of energy-transmission efficiency from 85% to 80%. In conclusion, the TET system with the hybrid energy coil can overcome the drawback of previously reported TET systems, and it promises to be the highest performance TET system in the world.
authors.affiliation: Department of Human Science and Informatics, Tokai University, Sapporo, Japan. okamoto@tspirit.htokai.ac.jp
authors.forename: Eiji
authors.initials: E
authors.lastname: Okamoto
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Yuhta
authors.initials: Y
authors.lastname: Akasaka
authors.forename: Tadashi
authors.initials: T
authors.lastname: Motomura
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Mitamura
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Nosé
mesh_terms: D011211:Electric Power Supplies; D004867:Equipment Design; D006353:Heart-Assist Devices; D006801:Humans; D055096:Optical Devices; D013696:Temperature