SPACE-FREQUENCY APPROACH TO DESIGN OF DISPLACEMENT TOLERANT TRANSCUTANEOUS ENERGY TRANSFER SYSTEM

One of the main concerns for transcutaneous energy transfer via inductive coupling is misalignments of coils, especially in the case of mechanical circulatory support systems, when coils placed on a chest wall or an abdomen. We proposed a space-frequency approach to this problem. It is possible to find values of so called splitting frequency by expression which incorporate the value of coupling coefficient. Given that coupling coefficient depends on the system geometry, it allows one to determine the optimal operating frequency for the specified relative position of the coils. Numerical calculations of transcutaneous energy transfer parameters show the capability of the proposed method. It was found that the operation at splitting frequency provided more stable output with respect to changes in a system geometry. The output power of the proposed system changes for not more than 5% for a distance in a range of 5-25 mm. At the same time, the output power of the system which operates at fixed resonant frequency changes for about 40%. Similar results were obtained for lateral displacements in a range of 0-20 mm.