IEC 62304 Draft: Software Architecture Description

Document Control

• Product: Onset iOS
• Version baseline: 1.2.6 (build 1)
• Status: Draft for FDA workstream kickoff

1. High-Level Components

• UI Layer (SwiftUI)
  Screens: Today, Daily Journal, Trends, Protocol/Routine editor, Settings.

• Domain/Engine Layer
  ProtocolEngine, InteractionEngine, generation/adaptation logic, feature-gated modifiers.

• Data Layer (SwiftData)
  Models: CheckIn, ProtocolCompletion, UserProtocolItem, UserPreferences, LabResult.

• External Integrations
  HealthKit read-only series, optional cloud AI backend (Supabase + model provider), RevenueCat subscription.

2. Regulatory Boundary Architecture

FeatureFlags acts as the primary safety gate: - Wellness profile: FDA-gated flags OFF - Adaptive profile: flags may be enabled only after clearance and verification

Critical gated boundaries: - ProtocolEngine.generateProtocol check-in/life-event adaptation - Interaction/advisory rendering in Today/Protocol/Scanner surfaces - Cloud AI insight/generator surfaces - Lab interpretation outputs

3. Data Flow Summary

1. User logs Daily Journal input.
2. Journal input persists to SwiftData.
3. Routine generation reads journal data.
4. If adaptiveProtocol == false, journal data is not used to mutate routine output.
5. Trends view reads persisted data and renders chart-only summaries.

4. Safety-Relevant Architectural Decisions

• Dual-layer gating: both computation and UI rendering are gated.
• Default-off adaptive profile: repository baseline keeps adaptive features disabled.
• No runtime self-learning model updates: cloud model calls are request/response only when enabled.
• Separation of concerns: data capture remains available even when adaptive processing is disabled.

5. Future FDA Architecture Work

• Hazard-controlled state machine for adaptive enablement.
• Signed configuration profile for regulated mode activation.
• Expanded observability trail for adaptive output provenance.