Iec 62366 Usability

IEC 62366 Usability Engineering for Medical Device Software

Purpose

Implement IEC 62366-1 usability engineering for software: identify use-related risks, iterate UI with formative evaluation, confirm risk controls with summative testing, and trace results to ISO 14971 and design/verification records.

When to Apply

• Any user-facing software where use error could contribute to harm (embedded UI, mobile apps, SaMD web).
• New workflows, alarms, dosing, navigation, or language/label changes.
• EU MDR GSPR usability expectations; FDA human factors / human factors submission packages.

Requirements (testable)

1. Use Specification: Define intended users, use environments, and critical tasks per IEC 62366-1; link to hazard-related use scenarios. Rationale: scope of evaluation.
2. User Interface Specification: Document UI elements that implement risk controls (labels, alarms, confirmations, defaults) per your design process; version with software. Rationale: controlled design outputs.
3. Formative Evaluation: For non-final UIs, run structured sessions; log defects/risks; iterate design before summative. Rationale: reduce residual use-error risk early.
4. Summative Evaluation: Execute final usability validation on representative users/tasks; pass/fail criteria tied to risk controls; record raw data and summaries. Rationale: objective evidence of safe use.
5. Risk Linkage: Map use-related hazards to ISO 14971 (HZ-*, RISK-CTRL-*); verify each control with summative or justified analysis. Rationale: closed-loop risk file.
6. Software Verification: Where UI implements a software requirement, link REQ-* to automated tests where possible and to usability study IDs for human-in-the-loop behavior. Rationale: dual path: technical + behavioral.
7. Labeling: Ensure on-screen strings and IFU excerpts match validated risk communication (warnings, contraindications). Rationale: consistency with labeling skill.

Recommended Practices

• Maintain a critical task list with trace IDs (UE-TASK-###).
• Capture UI screenshots in summative reports with build IDs.
• Use simulated use environments (lighting, noise, gloves) when relevant.

Patterns

Critical task trace (YAML):

ue_task:
  id: UE-TASK-014
  description: "Confirm dose before start infusion"
  hazards: ["HZ-USE-03"]
  risk_controls: ["RISK-CTRL-UI-09"]
  ui_elements:
    - id: "screen_confirm_dose"
      build: "v2.3.1"
  summative: "UE-SUM-2026-02"
  result: pass

Automated UI test with traceability (Python pseudo):

# REQ-UI-044: Confirm step shall block start until acknowledged (RISK-CTRL-UI-09)
def test_confirm_dose_requires_ack(screen):
    screen.enter_dose(10.0)
    assert not screen.can_start_infusion()
    screen.acknowledge_dose()
    assert screen.can_start_infusion()

Anti-Patterns (risks)

• Skipping formative on “simple” UI — risk: late discovery of use errors.
• Summative with developers as stand-in users — risk: invalid evidence.
• Changing UI strings post-summative without impact analysis — risk: labeling drift and unvalidated risk communication.

Verification Checklist

• Use specification and critical tasks documented and approved.
• Formative findings closed or mitigated before summative.
• Summative protocol executed; pass/fail per predefined criteria.
• Use-related risks updated in risk management file; residuals acceptable.
• UI build IDs and screenshots archived with release.
• REQ/RISK links updated for UI code and tests.

Traceability

• IDs: UE-TASK-###, UE-FORM-###, UE-SUM-###; link to HZ-*, REQ-*, TEST-*, release v*.*.*.

References

• IEC 62366-1:2015 (+ amendment), Medical devices — Application of usability engineering to medical devices.
• ISO 14971:2019 — risk management (use-related hazards).
• FDA Guidance: “Applying Human Factors and Usability Engineering to Medical Devices” (2016).
• EU MDR 2017/745 Annex I GSPRs (e.g., ergonomics, lay use where applicable).

Changelog

• 1.0.0 (2026-03-20): Initial skill covering formative/summative, critical tasks, risk linkage.