Wireless power transfer system for motorized intramedullary nail

This paper presents a Wireless Power Transfer (WPT) system designed to power motorized intramedullary nails used in limb-lengthening procedures. The system operates at 134 kHz and features a belt-like transmitting coil (TX) to be accommodated around the patient's pelvis and a receiving coil (RX) embedded within the distal portion of a femoral intramedullary nail. By integrating the RX coil directly into the implant, this approach eliminates the need for transcutaneous connections, reducing the risk of infections and enhancing patient comfort. The transmitting and receiving coils were configured to maximize voltage transfer to the load, ensuring sufficient power delivery to activate the nail's internal motor. A configuration with three series-connected TX coils and a spacing of 20 mm between them demonstrated the ability of delivering a 4,6 V peak voltage to the load ensuring typical operating conditions. The proposed WPT system represents a significant advancement for orthopedic implants, offering a practical and efficient solution for powering internal motors while addressing key limitations of existing technologies.