Remote Charging for Cardiac Pacemakers Using Transcutaneous Optical Energy Transmission System.

For cardiopathy patients with an implanted cardiac pacemaker, supplying power to the pacemaker is a challenging problem. In this study, we aim to design a transcutaneous optical energy transmission system that transmits optical energy from an optical-energy-generating circuit to a receiving circuit in a human body through the skin to charge the pacemaker's battery such that the battery supplies power to the pacemaker continuously. We use 0.5-mm-thick pigskin to imitate human skin tissue. The light source of the system is a halogen lamp and the receiver is a solar cell. The beam emitted by a the halogen lamp is transmitted to the solar cell through the skin generating a photovoltaic effect so as to charge the rechargeable button battery. As optical energy is received by a four-solar-cell module, we adopt a Zener voltage regulation circuit and a pure resistance circuit to charge the battery. Experimental data show that if a four-solar-cell module is used to charge a battery with the voltage regulation circuit, the battery after 62 h of charging stores enough power to operate the pacemaker for 20--35 days. On the other hand, charging the battery using the pure resistor circuit can reduce the charging time from 62 h to 14 h for the same number of operation days. If the number of solar cells in parallel is increased to 12, the charging time for the same number of operation days can be shortened from 14 h to 12 h with the pure resistance circuit. As a result, transcutaneous remote charging is achieved. Approaches to shorten the charging time and future works are proposed as well. [ABSTRACT FROM AUTHOR]