Transcutaneous Energy Transmission System for a Totally Implantable Total Artificial Heart Design and In Vivo Evaluation of the Energy Backup System

• Published in: Jinko Zoki Vol. 29; no. 1; pp. 24 - 30
• Main Authors: Shiba, K, Shu, E, Koshiji, K, Tsuchimoto, K, Tsukahara, K, Masuzawa, T, Kakuta, Y, Tatsumi, E, Taenaka, Y, Takano, H
• Format: Journal Article
• Language: Japanese
• Published: JAPANESE SOCIETY FOR ARTIFICIAL ORGANS 2000
• Subjects: artificial heart; backup system; emergency; energy transmission; rechargeable battery
• ISSN: 0300-0818; 1883-6097
• DOI: 10.11392/jsao1972.29.24

We have been developing an externally-coupled transcutaneous energy transmission system (ECTETS) for a totally implantable total artificial heart (TITAH) When a patient takes a bath or if some emergency of transcutaneous energy transmission occurs, the energy backup system must switch the energy source from the ECTETS to a rechargeable internal backup battery (RIBB). Then when the transcutaneous energy transmission has been restarted, the energy backup system must switch the energy source from the rechargeable battery to the ECTETS in order to drive TITAH and charge the RIBB. In this study, an energy backup system that can automatically switch energy sources without any discontinuity of the energy supply, was designed and manufactured on an experimental basis. Further, the performance of the energy backup system was evaluated in an in vivo experiment by implanting the secondary coil of the transcutaneous transformer and the RIBB (consisting of a series connection of seven Li+ rechargeable batteries) enclosed in a titanous canister in the goat body. As a result, it was found that the switch from the ECTETS to the RIBB requires 100ms and from the RIBB to the ECTETS 50ms. The total efficiency of the ECTETS with the energy backup system was 73-97%, and the temperatures of the implanted devices were less than 40.5°C. It is concluded that the ECTETS with an energy backup system performs adequately.