Following the magnetically coupled resonance principle, I built a wireless power transfer system to charge pacemakers wirelessly and studied its efficiency under different conditions.
At present, at least 5 million people worldwide rely on cardiac pacemakers to maintain their lives. However, pacemakers' batteries generally work for 5~7 years. Therefore, to avoid the patients' pain and economic burden when replacing the batteries for the implanted devices (pacemaker, etc.), a new wireless power transmission (WPT) technology for the pacemaker was explored. To obtain data for future application in human bodies with different fat levels, the effect of varying medium or biological tissue on the WPT performance (WPTP) was investigated.
Based on the principle of magnetically coupled resonance, a WPT system (WPTS) with coils on printed circuit boards (PCB) was fabricated, and the influence of thickness and conductivity of salt solution, agar (simulated body tissue), and pork (biological tissue) on the WPTP were quantitatively detected. In the air, the WPT efficiency is about 45%, and the maximum power transfer distance is 20cm. The WPTS can pass through 10cm thick agar and 6cm thick lean pork. For the same kind of medium, the WPT efficiency decreases as conductivity increases, and the agar has a stronger ability to block the magnetic field passing through compared to the brine.