Safety-Critical Cybersecurity Architecture for Robotic-Assisted Surgical Systems: Threat Modeling, IEC 62304 Compliance, and Navigation Platform Integrity in Multi-Site Integration Programs

Abstract

Robotic-assisted surgical systems have undergone a fundamental architectural transformation, evolving from isolated electromechanical platforms into networked, multi-vendor, software-intensive systems integrating pre-operative planning databases, intraoperative navigation streams, real-time robotic control interfaces, and post-operative outcome registries through hospital network infrastructure. This transformation has created a cybersecurity attack surface for which conventional medical device safety standards   including IEC 62304 and ISO 14971   provide necessary but insufficient governance, particularly in multi-vendor integration programs where two independently developed safety-critical systems are combined through defined software interfaces under organizationally distributed development governance. This article presents a practitioner-grounded cybersecurity architecture framework for navigation-integrated robotic surgical systems   the first to address multi-vendor platform integration as a distinct cybersecurity design challenge in this domain. The framework applies STRIDE threat modeling adapted to a five-layer surgical robotic architecture, producing pre-control risk scores across six attack surface domains using the NIST SP 800-30 criteria, with a maximum score of 20 for navigation data stream tampering. A layered control architecture   comprising physical plausibility validation, cryptographic HMAC-SHA256 navigation stream authentication, redundant position verification at critical anatomy proximity, and a statistical watchdog monitoring system   achieves a 73% aggregate residual risk reduction from a pre-control score of 84 to 23, with all six domain scores below the ISO 14971 Class C residual risk acceptability threshold. IEC 62304 software safety class escalation in multi-vendor integration scenarios is analyzed, introducing a four-category cross-organizational anomaly management framework (Type 1 through Type 4) that extends the standard's requirements to cybersecurity-specific defect classes. Post-market cybersecurity maintenance under FDA 2023 guidance is addressed, covering SBOM automation via SPDX and CycloneDX standards, a coordinated vulnerability disclosure protocol with CVSS-differentiated timelines, and a three-track intraoperative incident response framework delineating manufacturer, hospital IT, and clinical team responsibilities. The framework contributes a structured methodology for a cybersecurity design challenge that is growing in urgency as multi-vendor robotic surgical integration programs proliferate across specialties.