Design and Control of a Transcutaneous Power Regulator for Artificial Heart

In medical implant systems high efficiency and improving the patient’s mobility. Artificial organs and monitoring devices to be implanted into human body for the extension and the improvement of human lives. The implants must operate inside the body for the considerable period of time and communicate with outside world wirelessly for exchange of medical data and commands. Rechargeable batteries are recharged remotely through the human skin via inductive links. In my project transformer model a remote power supply for use in the artificial hearts for easy controllability and high efficiency, which can monitor the charging level of the battery has been designed and implemented. In order to recharge the battery the electro-magnetic coupling between primary coil and secondary coil has been used. Primary and secondary windings of the transformer are positioned outside and inside the human body respectively. In such a transformer, the alignment and gap may change with external positioning. The coupling coefficient of the transformer is also varying, and so are the tool to large leakage inductances and the mutual inductance. Resonance-tank circuits with varying resonance frequency are formed from the transformer inductors and external capacitors. A control method is proposed to lock the switching frequency at just above the load insensitive frequency for optimized efficiency at heavy loads. Specifically operation at above resonant of the resonance circuits is maintained under varying coupling coefficient. A transcutaneous power regulator is built and found to perform excellently with high efficiency and tight regulation under variations of the alignment or gap of the transcutaneous transformer load and input voltage. Keywords— IM-SOC (implantable system on chip), Artificial heart (AF), Transcutaneous energy transfer (TET).