| This dissertation reports on the design and testing of two novel trans-enteric magnetic induction transformers with circulatory support devices such as left ventricular assist devices (LVAD's), and additional sensor electronics system. This system herein described is capable of simultaneously performing two functions: (1) supplying power for circulatory support device operation, and (2) carrying bilateral communication signals (sensor data, control signals, etc.) between the circulatory support device and an external signal processing/diagnostic/control device. The system consists of three components: the transformer, power interface electronics, and data interface electronics. It differs from previous designs in a number of significant respects: (1) the device is trans-integumental rather transcutaneous, i.e., a pouch of small intestine (tangential but connected into the regular gastrointestinal system) is used to hold the device, (2) the device incorporates a high permeability core material configuration to increase the efficiency of operation, decrease size, and reduce stray electromagnetic fields in adjacent tissues, (3) the design problem was approached from an integrated perspective wherein impact of anatomical constrains and inter-component design decisions were considered together. This work describes two such transformer design configurations, each of which were fabricated, bench tested, and implanted for short-term (two-week) animal studies as well as four months, long term animal trials. Both designs were able to transmit 25 W at an output level of 12 VDC with DC-DC efficiencies greater than 80% and coil-coil efficiencies greater than 98%. Neither device demonstrated significant medical complications during these studies. |
