New linear motor concepts for artificial hearts

Total artificial hearts (TAHs), available in today's market, have the disadvantage of wear-prone components. Thus, their expectation of life is limited and the devices can only be used for temporary and not destination therapy. Durability- and wear-free operations are the critical requirements, as failure is an immediate threat to the patient's life. These attributes are combined in linear motors. In this paper, the potential of a linear motor as TAH's drive is shown by a prototype. On the basis of this prototype, different motor concepts are employed. The dimensions of each concept's geometry are first roughly determined by analytical optimization, and in a second step, more finely tuned by means of finite-element (FE) calculations. After optimization, two concepts achieve the requirements, provided by the natural heart of the human body. The first motor consists of moving coils and static permanent magnets, which are embedded in a flux concentrating geometry. To avoid the disadvantage of wear-prone power connection of the coils, the other concept consists of static coils and moving permanent magnets, arranged in a Halbach array. After constructing and testing both concepts in laboratory, animal experiments will follow to identify the superior one.