title: Selection of a rechargeable internal back-up battery for a totally implantable artificial heart.
abstract: Three kinds of rechargeable batteries, NiCd, NiMH, and Li+, were compared for the purpose of selecting the most appropriate battery for use in a Rechargeable Internal Back-up Battery (RIBB) unit for a Totally Implantable Artificial Heart. Batteries of each kind were connected in series to obtain the required driving voltage of 24 V. The NiCd and NiMH batteries were charged by a constant current of 1 C, and the Li+ batteries were charged first by a constant current of 1 C and later by a constant voltage of 28.7 V. All three types of batteries were discharged using a dummy electronic pulsatile load consuming 20 W of power. The tests showed that the Li+ batteries were capable of supplying the required energy for more than 60 minutes. The Li+ batteries had a specific energy of 121.5 Wh/kg, which was more than 3x that of the NiCd and NiMH, and an energy density of 282.5 Wh/L more than double that of the other two. In addition, the Li+ batteries recorded the least temperature rise during charging and discharging. The results of our tests conclusively showed that the Li+ battery is the best among the three for use in an RIBB from the viewpoint of energy density and temperature rise.
authors.affiliation: Department of Electrical Engineering, Science University of Tokyo, Chiba, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Honda
authors.forename: K
authors.initials: K
authors.lastname: Shiba
authors.forename: E
authors.initials: E
authors.lastname: Shu
authors.forename: K
authors.initials: K
authors.lastname: Koshiji
authors.forename: T
authors.initials: T
authors.lastname: Murai
authors.forename: T
authors.initials: T
authors.lastname: Nakamura
authors.forename: T
authors.initials: T
authors.lastname: Masuzawa
authors.forename: E
authors.initials: E
authors.lastname: Tatsumi
authors.forename: Y
authors.initials: Y
authors.lastname: Taenaka
authors.forename: H
authors.initials: H
authors.lastname: Takano
mesh_terms: D004560:Electricity; D006354:Heart, Artificial