Golden Age Hub - Architecture Overview¶
The Golden Age Hub platform coordinates wearable edge devices, real-time streaming queues, and secure database engines to deliver audit-ready healthcare tracking. This document describes the system architecture, design decisions, and data pipelines that power our zero-data AI and cryptographic care ledger.
System Architecture (Expanded Scope)¶
Stack¶
- Device (Companion Patch): BLE + NFC; offline-first; watch‑dog firmware; event batching.
- Gateway/App (Caregiver Mobile App): Syncs patch data; quick‑add logs; patient training module.
- API Backend (FastAPI): AuthN/Z, event ingest, Proof‑of‑Care Ledger, exports, policy engine.
- Data: PostgreSQL with TimescaleDB (primary), Redis (queues/rate‑limits), S3‑compatible object store (US‑only).
- Ledger: Append‑only chain with hash‑linked blocks; per‑patient Merkle rollups; audit export.
- Dashboards: Web Dashboard with caregiver, family read‑only, and agency admin views.
- Observability: Structured logs, request tracing, metrics; US‑only sinks.
- ML/AI Stack: TensorFlow Lite, ONNX Runtime, Flower (FLWR); edge inference and federated learning.
- Data Governance: HIPAA compliance, provenance tracking, schema validation.
Principles¶
- Zero‑Data AI: On-device inference; no raw audio/video storage; only signals/features.
- Queueing Theory: Rate‑limit alerts; backoff under load; service level targets encoded in backend services.
- Control Theory: Hysteresis on fall/wandering triggers; debounce + confirmation windows (see Event Processing Pipeline).
- Information Theory: Denoise signals; maximize signal‑to‑noise before raising alerts (see Model Training Pipeline).
- Security: Zero‑trust architecture; signed events (device key); at‑rest & in‑transit encryption; key rotation.
- Sovereignty: U.S. persons, U.S. regions, U.S. vendors (see Compliance).
- Data Governance: Schema-first design, provenance tracking, privacy preservation.
- Edge Intelligence: Local processing, federated learning, model lifecycle management.
Core Flows¶
- Event Ingest: device → app/gateway →
/events(signed payload) → queue → validate → persist. - Ledger Write: care action → normalized event → hash block with sigs + timestamps → store in immutable ledger.
- Alert Router: policy engine applies guardrails/rate‑limits → caregiver route → escalation.
- ML Processing: Edge inference → federated learning → model updates.
- Data Governance: Schema validation → provenance tracking → compliance automation.
- Exports: EVV/RPM endpoints generate CSV/JSON with checksums for audit.
Table of Contents¶
- System Architecture (Expanded Scope)
- Stack
- Principles
- Core Flows
- Overview
- MVP Core Components
- Companion Patch
- Caregiver Mobile App
- Backend Services
- Edge Computing Hub
- Web Dashboard
- Machine Learning Architecture
- Model Training Pipeline
- Edge Inference Architecture
- Federated Learning Architecture
- Model Lifecycle Management
- Data Governance Framework
- Schema Management
- Provenance and Audit Trail
- Privacy Preservation
- Compliance Automation
- Data Flow
- Event Processing Pipeline
- Data Storage
- Data Quality Validation
- Security Architecture
- Edge Computing Architecture
- Deployment Architecture
- Scaling Considerations
Overview¶
Golden Age Hub delivers comprehensive elderly care through advanced technology integration. The platform combines traditional healthcare coordination with cutting-edge AI/ML capabilities, all while maintaining strict privacy and compliance standards.
Key Differentiators:
- Edge Intelligence: Real-time ML inference on wearable devices
- Zero-Data AI: Federated learning preserves privacy while improving models
- Data Sovereignty: Comprehensive governance framework with HIPAA compliance
- Care Coordination: Unified platform for care delivery and documentation
System Topology¶
flowchart TB
subgraph Wearable ["Wearable IoT Device"]
Patch["Companion Patch BLE/NFC"]
TFLite["Edge Fall Detection (TFLite Micro)"]
Patch --> TFLite
end
subgraph Client ["Client / Gateway Layer"]
App["Caregiver Client Gateway"]
Wearable -->|Signed Telemetry| App
end
subgraph Backend ["Backend Gateway & Broker (FastAPI + Redis)"]
GW["API Gateway (FastAPI: Port 8000)"]
Sec["Security Filter:\n• Ed25519 Signatures\n• Replay Protection\n• Token Rate Limiting"]
Queue["Redis Queue (Broker)"]
App -->|POST /v1/events/ingest| GW
GW --> Sec
Sec -->|Valid Payloads| Queue
end
subgraph Processing ["Asynchronous Worker (Celery)"]
Worker["Celery Worker (Pipeline Service)"]
Queue -->|Fetch Tasks| Worker
end
subgraph Storage ["Storage & Verification Layer"]
DB[("PostgreSQL / TimescaleDB\n• Sensor Hypertables\n• Audit logs\n• Relational data")]
Merkle["Merkle Care Ledger\n• Leaf inclusion proofs\n• Sealed block chains"]
S3[("S3 A2 Archive\n• WORM compliance cold logs")]
Worker -->|1. Write logs| DB
Worker -->|2. Archive cold| S3
Worker -->|3. Append tree| Merkle
Merkle -->|Generate proof| DB
end
subgraph Decision ["Alert Evaluation & Policy Engine"]
Policy["Policy Service (OPA: Port 8877)"]
Tuning["Tuning Script (ab_compare / tune_policy)"]
Worker -->|Evaluate routing| Policy
Tuning -->|Refine rules| Policy
end
subgraph Presentation ["Stakeholder Dashboards"]
Dash["Main Dashboard (React: Port 3000)"]
SimDash["Simulator Dashboard (React: Port 3003)"]
DB -->|Query status| Dash
Policy -->|Active alert route| Dash
SimDash -->|Control streams| App
end
MVP Core Components¶
1. Companion Patch (Wearable Device)¶
- Sensors: 6-axis IMU (accelerometer + gyroscope)
- Edge Processing: On-device fall and wandering detection using TensorFlow Lite
- Connectivity: Bluetooth Low Energy (BLE) to caregiver app
- Power: Rechargeable battery with 7+ day life
- Security: Hardware-backed key storage, signed events
- ML Capabilities: Optimized models for sub-500ms inference latency
2. Caregiver Mobile App¶
- Offline-First: Works without internet connection
- Real-time Alerts: Push notifications for events
- Simple Interface: Quick event acknowledgment
- Secure Sync: End-to-end encrypted data transfer
- Platforms: iOS and Android (React Native)
- Edge Integration: Direct communication with wearable devices
3. Backend Services¶
- API Layer: FastAPI (Python 3.10+) with comprehensive OpenAPI documentation
- Database: PostgreSQL 14+ with TimescaleDB extension for time-series data
- Authentication: JWT with device-based authentication
- Core Endpoints:
- Device registration and authentication
- Event ingestion and processing
- Data exports (EVV/RPM)
- Proof of Care ledger
- Model management and deployment
- Schema validation and governance
- Data Processing: Real-time event validation and enrichment
- Compliance Engine: Automated HIPAA compliance checking
4. Edge Computing Hub¶
- Hardware: NVIDIA Jetson or micro form-factor PC
- Connectivity:
- BLE for wearable device communication
- WiFi/Ethernet for cloud connectivity
- Local network for caregiver app access
- Storage:
- Local encrypted storage for sensor data and events
- Model versioning and experiment tracking
- ML Ops (ZenML):
- Local model training pipeline orchestration
- Experiment tracking and model versioning
- Data validation and preprocessing
- Model evaluation and validation
- Federated Learning:
- Personalized model initialization from meta-models
- Local model training on private data
- Secure gradient sharing with central server
- Differential privacy for model updates
- Processing:
- Runs real-time ML models for fall and wandering detection
- Processes and analyzes sensor data streams
- Generates and stores events locally
- Performs on-device model fine-tuning
- Security:
- On-device encryption for stored data
- Secure authentication for all connected devices
- Role-based access control for data access
- Local data storage with HIPAA-compliant encryption
- Federated learning with differential privacy
5. Web Dashboard¶
- Caregiver View: Patient monitoring and alerts with ML insights
- Admin View: User and device management with governance controls
- Family Portal: Read-only access to loved one's status
- Export Tools: Generate compliance reports with audit trails
- Analytics Dashboard: Privacy-preserving insights and model performance metrics
Machine Learning Architecture¶
Model Training Pipeline¶
- Data Collection: Wearable devices stream sensor data to the Edge Hub
- Data Preprocessing:
- Data cleaning and normalization with schema validation
- Feature extraction with provenance tracking
- Data labeling (semi-supervised where applicable)
- Model Training:
- Initialize with latest meta-model from central server
- Fine-tune on local data using ZenML pipelines
- Apply differential privacy if sharing updates
- Model Evaluation:
- Validate performance on held-out test set
- Check for model drift and bias
- Ensure fairness and bias mitigation
- Compliance certification for production deployment
- Federated Updates:
- Securely share model updates with central server
- Receive aggregated model improvements
- Update local model while preserving privacy
Edge Inference Architecture¶
- Model Optimization: Quantization for reduced latency and memory usage
- Hardware Acceleration: GPU/TPU support for real-time inference
- Memory Management: Efficient model loading and caching
- Power Optimization: Adaptive inference scheduling
- Fallback Mechanisms: CPU-only inference when hardware unavailable
Federated Learning Architecture¶
- Decentralized Training: Edge devices train on local data
- Secure Aggregation: Cryptographic protocols for gradient aggregation
- Privacy Budgeting: Differential privacy budget management
- Model Personalization: Individual model adaptation from global updates
- Communication Efficiency: Compressed gradient updates
Model Lifecycle Management¶
- Version Control: Git-like operations for models and datasets
- Experiment Tracking: Comprehensive MLflow integration
- Deployment Automation: CI/CD pipelines for model deployment
- Monitoring: Performance drift detection and alerting
- Rollback Capabilities: Safe model rollback with audit trails
Data Governance Framework¶
Schema Management¶
- JSON Schema Validation: Draft 7 compliance for all data structures
- Schema Registry: Centralized schema management and versioning
- Data Contract Testing: Automated validation of data contracts
- Schema Evolution: Backward-compatible schema updates
Provenance and Audit Trail¶
- Data Lineage: Complete transformation history tracking
- Audit Logging: Comprehensive audit trails for compliance
- Digital Signatures: Cryptographic verification of data integrity
- Retention Policies: Automated data lifecycle management
Privacy Preservation¶
- Differential Privacy: Statistical noise addition for privacy
- Data Minimization: Collect only necessary data
- Purpose Limitation: Clear data usage boundaries
- Consent Management: Granular consent tracking and enforcement
Compliance Automation¶
- HIPAA Compliance Engine: Automated compliance checking
- Policy as Code: Rego policies for data governance
- Automated Reporting: Compliance report generation
- Breach Detection: Real-time breach monitoring and alerting
Data Ingestion and Storage Architecture¶
To ensure high availability, scalability, and data integrity, the system uses a decoupled, asynchronous pipeline for event ingestion, along with a two-tiered storage strategy.
Queue-to-Storage Pipeline¶
Instead of writing directly to the database upon ingestion, the API endpoint follows a more resilient pattern:
- Fast Ingress: The
/v1/events/ingestendpoint performs only initial, lightweight validation (Schema, Auth, Rate Limit). - Queuing: If valid, the raw event is pushed to a durable message queue (e.g., Redis Streams, RabbitMQ). The client immediately receives a
202 Acceptedresponse. - Asynchronous Processing: A separate pool of "pipeline workers" consumes events from the queue. This decouples the ingestion rate from the processing rate, allowing the system to absorb bursts of traffic. If a worker fails, the event is safely retained in the queue for another worker to process.
Two-Tiered Storage Strategy¶
The pipeline workers write data to two distinct storage destinations, each optimized for a specific purpose:
1. Normalized Store (The "Hot" Engine)¶
- Technology: PostgreSQL with the TimescaleDB extension.
- Purpose: The primary operational database for real-time dashboards, mobile app queries, and reporting. It is optimized for performance.
- Strategy: Raw JSON events are "shredded" or normalized into structured, relational tables (e.g.,
events,event_locations). This allows for fast, indexed queries. TimescaleDB's features like hypertables and compression are used to efficiently manage and query vast amounts of time-series data.
2. Raw Archive Location (The "Cold" Vault)¶
- Technology: An S3-compatible object store (e.g., American Cloud A2, MinIO) with U.S.-only data residency.
- Purpose: The immutable, long-term (7+ years) source of truth for compliance and auditing. It is optimized for durability and low cost.
- Strategy: The original, signed, canonical JSON payload for every event is stored here without modification. WORM (Write-Once, Read-Many) policies are enforced to guarantee that the raw data can never be altered, providing a cryptographically verifiable audit trail.
Data Flow¶
Event Processing Pipeline¶
- Data Collection: Wearable device collects sensor data and streams to Edge Hub via BLE
- Schema Validation: Incoming data validated against registered schemas
- Local Processing: Edge Hub runs ML models to analyze sensor data in real-time
- Provenance Recording: Data lineage and transformation history recorded
- Event Detection: Potential events are detected and verified on the Edge Hub
- Privacy Preservation: Differential privacy applied to sensitive data
- Local Storage: Raw sensor data and events are stored securely on the Edge Hub
- Access Control: Patient-managed permissions control data access
- Caregiver Notification: Authorized caregivers receive real-time alerts through the mobile app
- Cloud Sync: Anonymized/aggregated data is synced to the cloud when online
- Backend Processing: Cloud backend processes and stores events
- Compliance Checking: Automated compliance validation and reporting
- Dashboard Updates: Web dashboard is updated with the latest information
Data Storage¶
Edge Hub Storage¶
- Raw Sensor Data: 7 days of high-frequency sensor data (encrypted)
- Local Events: 30 days of processed events and alerts (with provenance)
- Access Logs: 90 days of access and permission logs (auditable)
- Model Artifacts: Local model versions with integrity verification
Cloud Storage¶
- Hot Storage: 30 days of raw sensor data (anonymized)
- Warm Storage: 2 years of processed events (with full provenance)
- Cold Storage: 7+ years of audit logs (immutable)
- Immutable Ledger: All care events in append-only format (blockchain-inspired)
Data Quality Validation¶
- Schema Compliance: JSON Schema validation for all data structures
- Statistical Validation: Distribution and outlier detection
- Completeness Checks: Missing data identification and handling
- Privacy Compliance: PII detection and anonymization verification
- Automated Reporting: Data quality metrics and improvement recommendations
Security Architecture¶
Data Protection¶
- End-to-end encryption for all data in transit
- Encryption at rest for sensitive data with key rotation
- Regular security audits and penetration testing
- US-based data centers with strict access controls
- Hardware Security Modules (HSMs) for key management
Access Control¶
- Role-based access control (RBAC) with fine-grained permissions
- Multi-factor authentication for admin users
- Device attestation for all API requests
- Zero-trust network architecture
- Comprehensive audit logging with tamper detection
Compliance¶
- HIPAA Security and Privacy Rules (automated validation)
- SOC 2 Type II certification (in progress)
- Regular third-party security assessments
- Breach notification procedures with automated response
- Privacy by Design principles throughout the architecture
Edge Computing Architecture¶
Hardware Architecture¶
- Wearable Devices: Ultra-low power ML inference with TensorFlow Lite Micro
- Edge Gateways: NVIDIA Jetson or similar for local processing
- Mobile Devices: ONNX Runtime for cross-platform inference
- Embedded Systems: Custom hardware for specialized use cases
Software Architecture¶
- Inference Engine: Hardware-accelerated ML inference
- Communication Layer: Secure device-to-cloud communication
- Storage Layer: Local encrypted storage with synchronization
- Management Layer: Over-the-air updates and configuration
Network Architecture¶
- Local Networks: BLE and WiFi for device connectivity
- Edge-to-Cloud: Secure MQTT/WebSocket communication
- Federated Learning: Peer-to-peer and centralized coordination
Deployment Architecture¶
Environments¶
- Development: Local Docker containers with hot reload
- Staging: Isolated cloud environment with production-like scale
- Production: Multi-AZ deployment for high availability
- Edge: Distributed deployment across healthcare facilities
Infrastructure¶
- Compute: Containerized services (Docker) with edge optimization
- Orchestration: Kubernetes for cloud, Docker Compose for edge
- Database: Managed PostgreSQL with read replicas and automated failover
- Storage: Encrypted block storage with backup and disaster recovery
- Monitoring: Comprehensive observability stack with edge-specific metrics
CI/CD Pipeline¶
- Model Pipeline: Automated ML model training and deployment
- Data Pipeline: Schema validation and data quality checks
- Application Pipeline: Multi-stage deployment with rollback capabilities
- Edge Pipeline: Over-the-air updates for edge devices
Scaling Considerations¶
- Designed for 10,000+ active patients across multiple facilities
- Horizontal scaling for API layer with auto-scaling groups
- Read replicas for reporting and analytics workloads
- Caching layer (Redis) for frequently accessed data
- Edge distribution for local processing and reduced latency
- Federated learning for decentralized model training
- Data partitioning strategies for large-scale datasets
Technology Integration Points¶
Third-Party Integrations¶
- EHR Systems: HL7 FHIR interfaces for medical record integration
- Telemedicine Platforms: Video consultation and remote monitoring
- IoT Devices: Additional sensor integration (vital signs, environmental)
- Emergency Services: Automated emergency dispatch integration
API Ecosystem¶
- REST APIs: Comprehensive OpenAPI-compliant interfaces
- GraphQL: Flexible querying for complex data relationships
- WebSocket APIs: Real-time event streaming
- gRPC APIs: High-performance edge-to-cloud communication
Data Exchange Standards¶
- HL7 FHIR: Healthcare interoperability standard
- OpenEHR: Clinical data models and archetypes
- OMOP CDM: Observational Medical Outcomes Partnership Common Data Model
- CDISC: Clinical data interchange standards for research
Future Enhancements¶
Short Term (Post-MVP)¶
- Advanced analytics and machine learning with federated learning
- Integration with EHR systems for seamless data flow
- Additional sensor support (vital signs, environmental monitoring)
- Expanded caregiver collaboration tools with real-time coordination
Medium Term¶
- Predictive analytics for care planning and intervention
- Computer vision for activity recognition and safety monitoring
- Natural language processing for clinical documentation
- Advanced federated learning with multiple healthcare providers
Long Term Vision¶
- Autonomous care coordination with AI-driven care plans
- Population health management across multiple facilities
- Personalized medicine integration with genetic and biomarker data
- Global research collaboration while maintaining data sovereignty