Toward safe clinical deployment of remote robotic surgery in Japan: five-year validation of the hinotori™ system using 5G wireless communication

Abstract

Remote robotic-assisted surgery (RRAS), a form of telesurgery, offers a potential solution to Japan's surgeon shortage and regional disparities in care. Despite advances in robotic systems and modern communication technologies, including both 5G wireless and wired networks, clinical adoption remains limited due to regulatory, infrastructural, and institutional barriers. This review consolidates five years (2020-2025) of technical and operational validation of the hinotori™ Surgical Robot System-a domestically developed platform-in alignment with the 2022 Japanese Remote Surgery Guidelines. Based on over 30 remote-session evaluations by Kobe University, Medicaroid, and NTT DOCOMO, we summarize system performance across key domains: communication latency, QoS-based prioritization, VPN redundancy, fail-safe mechanisms, electromagnetic compatibility, human-system interaction, and legal compliance. Under optimized Sub6 5G SA conditions, the system consistently achieved a round-trip latency of approximately 100 ms and stable stereoscopic video transmission, even during simulated 1 Gbps congestion. Safety was ensured through automatic standby, dual-cockpit fallback, and real-time monitoring. Although hinotori™ meets technical and safety criteria, full-scale implementation remains constrained by legal requirements-particularly the mandate for an on-site physician under Article 20 of the Medical Practitioners Act. Supervised telesurgery, where remote surgeons assist on-site teams, is legally permissible and may serve as a transitional model. This review integrates technical findings with policy considerations, proposing a path toward safe, equitable, and sustainable RRAS deployment in Japan. To our knowledge, this is the first comprehensive review aligning domestic telesurgical validation with national policy benchmarks, offering a foundation for future regulation, accreditation, and digital surgical integration.