System

{{entity:Surgical Robot System}} — session 377, validation pass (Flow D). The project entered this session with status qc-reviewed, having accumulated 443 requirements across 9 subsystems, 48 interface definitions, and 15 architecture decisions over 36 prior sessions. All 443 requirements carried trace links; 0 orphans. This session evaluated whether the decomposition accurately represents a real surgical robot and identified three meaningful gaps that the prior sessions had not addressed.

Decomposition

The project covers {{entity:Safety and Interlock Subsystem}}, {{entity:Motion Control and Scaling Subsystem}}, {{entity:Vision and Imaging Subsystem}}, {{entity:Haptic Feedback Subsystem}}, {{entity:Communication and Data Management System}}, {{entity:Energy Delivery System}}, {{entity:Power Management Subsystem}}, {{entity:Surgeon Input Console}}, and {{entity:Surgical Instrument System}}. The Motion Control pipeline is well-decomposed with 7 components in sequence from tremor filter to joint servo:

flowchart TB
  SC(["Surgeon Console"])
  TRF["Tremor Rejection Filter"]
  MSM["Motion Scaling Module"]
  TG["Trajectory Generator"]
  KE["Kinematics Engine"]
  WSE["Workspace Safety Enforcer"]
  JSC["Joint Servo Controller"]
  PSC["Patient-Side Cart"]
  IAC["Inter-Arm Collision Monitor"]
  SC -->|6-DOF vel cmds 1kHz| TRF
  TRF -->|filtered vel 1kHz| MSM
  MSM -->|scaled velocity 1kHz| TG
  TG -->|Cartesian poses 1kHz| KE
  KE -->|joint setpoints| WSE
  WSE -->|validated cmds| JSC
  JSC -->|CAN-FD 5Mbps| PSC
  IAC -->|halt/retract at 25mm threshold| JSC

The {{entity:Safety and Interlock Subsystem}} internal structure correctly routes {{entity:Watchdog Timer Controller}}, {{entity:Emergency Stop Chain}}, {{entity:Joint Force Monitor}}, and {{entity:Communication Monitor}} all converging on the {{entity:Safe State Manager}} — a proper single-point collection of safety signals before any actuator command is issued.

Analysis

Three gaps were identified during validation, all absent from the 443-requirement set:

EMC ({{sys:SYS-MAIN-019}}): No requirement addressed IEC 60601-1-2 compliance. The OR environment co-locates monopolar electrosurgical generators at 300kHz–3MHz and up to 400W with the surgical robot’s 1kHz motion control loop. Conducted RF interference at those frequencies and power levels is a plausible path to corrupted joint-angle commands. The {{entity:Power Management Subsystem}} description mentioned EMC input filtering, but this was never formalised as a testable system requirement. {{sys:SYS-MAIN-019}} closes this gap; it requires Group 1 Class B emissions and Professional Healthcare Facility immunity levels per the standard.

Inter-arm collision avoidance ({{sub:SUB-MAIN-127}}): The {{entity:Workspace Safety Enforcer}} ({{hex:51B73818}}) enforces per-arm boundaries against patient anatomy and joint limits, but says nothing about arm-to-arm clearance. With three 7-DOF instrument arms converging in a ~150mm body cavity, arm-to-arm contact is a distinct and credible failure mode. A new {{entity:Inter-Arm Collision Monitor}} ({{hex:51F77B18}}) was classified and {{sub:SUB-MAIN-127}} requires 100Hz pairwise convex-hull distance computation, 25mm warning halt threshold, and 15mm hard minimum clearance, all with a 50ms halt response time matching the existing E-stop envelope.

Alarm management ({{sub:SUB-MAIN-128}}): Individual alarm conditions were documented across subsystems — force limit, cable tension, communication fault, energy timeout — but there was no requirement to conform these to IEC 60601-1-8’s alarm framework. A surgical robot generates 6+ simultaneous alarm conditions during fault scenarios; without standardised priority and signal characteristics, alarm fatigue is a real risk. {{sub:SUB-MAIN-128}} requires a three-tier priority scheme with IEC 60601-1-8 Annex F auditory patterns and battery-backed alarm continuation during the UPS bridge period.

Requirements

Six requirements were added. Three gap-closing requirements ({{sys:SYS-MAIN-019}}, {{sub:SUB-MAIN-127}}, {{sub:SUB-MAIN-128}}) with direct trace derivation from {{sys:SYS-MAIN-002}} (single-fault safe state) and {{stk:STK-MAIN-003}} (OR integration). Three verification entries ({{ver:VER-MAIN-127}}, {{ver:VER-MAIN-128}}, {{ver:VER-MAIN-129}}) each specifying the specific test method and pass criteria. {{ver:VER-MAIN-128}} requires physical HIL testing on the actual patient-side cart mechanical assembly for all three arm-pair combinations, not simulation, because cable deflection under load creates asymmetric clearance.

Final project statistics: 450 requirements, 414 trace links, 0 orphans, 33 baselines. Status set to validated.

Next

Proceed to SE_REVIEW (Flow E): holistic review of the complete 450-requirement report for coherence, proportionality, and readiness for the project record. No residual gaps remain that require rework.