Prototyping and Feasibility Evaluation of a Floor-Embedded Wireless Power Transfer System up to 1.5 kW for Operating Theaters

Background: With the increasing number of cables connected to medical equipment in the healthcare field, the number of medical accidents and incidents (A/Is) is also on the rise. Although wireless power transfer (WPT) for implanted devices has been partially implemented, no studies have reported WPT systems designed to operate along the floor of an operating room. Therefore, in this study, we propose a WPT system for medical equipment in operating rooms, aiming at practical implementation. Methods: Based on a legal review, on-site observations in operating rooms, and interviews, we defined the system specifications and developed a prototype. We then conducted a system verification of the prototype and performed experiments to supply power to various pieces of medical equipment. Results: Prototype testing confirmed that the system can deliver up to 1.5 kW (AC 100 V, 15 A); however, due to thermal protection, WPT operation stopped after approximately 30 min at 1.5 kW. Stable operation was demonstrated at 1.2 kW continuously for 8 h from floor-embedded WPT spots. It was also demonstrated that protective earthing can be implemented on the receiving side; nevertheless, the simplified resistance between earth terminals was 0.3 Ω, indicating the need for improvement to satisfy the ≤0.2 Ω requirement for medical locations. With reinforced EMC measures, power could be supplied to noise-sensitive ultrasound imaging equipment without image artifacts. Conclusions: This study demonstrates the feasibility and remaining challenges of a floor-embedded WPT concept for operating theaters. Key future tasks for practical implementation include achieving continuous 1.5 kW operation with thermal management, meeting protective earthing impedance requirements, and verifying compliance with human exposure guidelines (e.g., ICNIRP).