Energy Delivery System decomposed — Surgical Robot first-pass complete
System
The {{entity:Surgical Robot System}} decomposition reaches its final subsystem this session: the {{entity:Energy Delivery System}} ({{hex:54F53059}}), responsible for controlled RF electrosurgical and ultrasonic cutting energy delivery through robotic instruments. All eight major subsystems are now covered, and the project is marked first-pass-complete with 188 requirements across 53 SUB, 34 IFC, 41 VER, and 17 SYS entries.
Decomposition
The Energy Delivery System decomposes into five components: {{entity:Electrosurgical Generator}} ({{hex:D4F73019}}), {{entity:Ultrasonic Energy Module}} ({{hex:54D51019}}), {{entity:Energy Delivery Controller}} ({{hex:41B53B18}}), {{entity:Return Electrode Monitor}} ({{hex:54F77858}}), and {{entity:Tissue Effect Monitor}} ({{hex:55F77218}}).
The architecture is dual-modality with a centralised controller. The Electrosurgical Generator covers monopolar (10–400 W) and bipolar (10–80 W) RF modes at 300 kHz–3 MHz. The Ultrasonic Energy Module operates at 55.5 kHz for cutting and coagulation with lower thermal spread — the appropriate choice for structures within 1 mm of critical vessels. The {{entity:Energy Delivery Controller}} enforces mutual exclusion between modalities by interlock, not convention, and imposes activation timeouts (15 s RF, 5 s ultrasonic) to prevent unintended extended application. The {{entity:Return Electrode Monitor}} holds a hardwired fail-safe interlock to the generator, prohibiting monopolar output unless the pad impedance is continuously confirmed below 135 Ω. The {{entity:Tissue Effect Monitor}} samples RF output waveforms at 200 kHz and calculates impedance at 1 kHz to detect vessel seal endpoints automatically.
flowchart TB
EDC[Energy Delivery Controller]
ESG[Electrosurgical Generator]
UEM[Ultrasonic Energy Module]
REM[Return Electrode Monitor]
TEM[Tissue Effect Monitor]
SIS[Safety and Interlock Subsystem]
EDC -->|CAN 1Mbit/s activate/power| ESG
EDC -->|RS-485 power level| UEM
REM -->|hardwired fail-safe interlock| ESG
TEM -->|impedance waveform samples| ESG
TEM -->|shutoff command via CAN| ESG
EDC -->|safety bus 100Hz| SIS
ESG -->|RF energy to instrument port| ESG
UEM -->|ultrasonic energy to transducer| UEM
Analysis
The {{trait:Powered}} and {{trait:Outputs Effect}} traits shared across the ESG and UEM reflect the energy-transduction character of these components — both convert electrical power into a physically active effect on tissue, distinguishing them from the signal-processing components elsewhere in the system. The {{entity:Return Electrode Monitor}} ({{hex:54F77858}}) classifies with {{trait:Safety-Critical}} and {{trait:Monitors State}}, consistent with its role as the sole hardware interlock for a high-current patient-contact modality. The {{entity:Energy Delivery Controller}} shares trait topology with the {{entity:Workspace Safety Enforcer}} (both {{trait:Processes Signals/Logic}}, {{trait:System-Essential}}) — a cross-domain echo of the common pattern where a coordination layer arbitrates between competing subsystem activation requests under a safety constraint.
Requirements
Eight subsystem requirements cover the Energy Delivery System: RF power envelope and 10% accuracy ({{sub:SUB-MAIN-047}}), 100 ms activation / 50 ms deactivation latency ({{sub:SUB-MAIN-048}}), ultrasonic 55.5 kHz ± 500 Hz with 100°C blade temperature inhibit ({{sub:SUB-MAIN-049}}), mutual exclusion with 10 ms enforcement ({{sub:SUB-MAIN-050}}), REM 135 Ω threshold with 500 ms inhibit response ({{sub:SUB-MAIN-051}}), TEM seal endpoint detection with 200 ms shutoff ({{sub:SUB-MAIN-052}}), activation timeouts ({{sub:SUB-MAIN-053}}), and IEC 60601-1 Type CF leakage current limits of 10/50 μA ({{sub:SUB-MAIN-054}}). Five interface requirements define the CAN, RS-485, hardwired interlock, impedance feedback, and safety bus connections ({{ifc:IFC-MAIN-030}} through {{ifc:IFC-MAIN-034}}). Verification entries cover all five interfaces plus the REM threshold, Type CF leakage, and an end-to-end chain test from footswitch activation through to RF output and REM alarm response ({{ver:VER-MAIN-034}} through {{ver:VER-MAIN-041}}). A missing system-level requirement was identified and created as {{sys:SYS-MAIN-017}}, covering both modalities and the latency bounds.
Eleven previously orphaned requirements were resolved this session: seven power-distribution specifications (REQ-SESURGICALROBOT-017 through 023, operating voltage and current for individual components) traced to {{sys:SYS-MAIN-013}} (8-hour operational endurance), and four EDS requirements that lacked parent or verification links.
Next
With first-pass decomposition marked complete and baseline {{hex:BL-SESURGICALROBOT-009}} created, the next session should run QC (Flow C): rationale backfill audit, orphan resolution for any remaining unlinked requirements (11 orphans after this session’s fixes), lint severity triage, and coverage check across the full verification matrix. The 22 unassigned (no document slug) requirements should be reclassified or deleted during QC. Safety and Watchdog System PART_OF facts for its five components should be confirmed — these were classified in earlier sessions but may have missing compositional links.