Hospital Information System - System Context Diagram

A C4 model for a Hospital Information System (HIS) provides a hierarchical view of the architecture, from high-level context to detailed component interactions. This approach ensures stakeholders understand the system’s scope, relationships, and technical implementation.

1. Context Diagram (Level 1)

• Primary Actors:
  • Patients: Access portals for appointments, test results, and billing.
  • Clinical Staff: Doctors, nurses, and technicians using EHRs, order entry, and patient monitoring tools.
  • Administrative Staff: Manage scheduling, billing, and HR functions.
  • External Systems: Integrate with pharmacies, labs, insurance providers, and public health agencies.
• Core System:
  • HIS: Centralized platform managing patient records, appointments, clinical workflows, and billing.

2. Container Diagram (Level 2)

• Containers:
  • Web Application: Frontend for clinical and administrative users (e.g., React-based portal).
  • Mobile App: Patient-facing interface for appointments and health tracking (iOS/Android).
  • API Gateway: Routes requests to microservices (e.g., Express.js).
  • Microservices:
    • EHR Service: Manages patient records, allergies, and treatment history.
    • Appointment Service: Handles scheduling and resource allocation.
    • Billing Service: Processes insurance claims and patient invoicing.
    • Notification Service: Sends alerts (e.g., appointment reminders, lab results).
  • Databases:
    • Relational DB: Stores structured data (patients, staff, appointments).
    • NoSQL DB: Manages unstructured data (clinical notes, images).
  • Message Broker: Enables asynchronous communication (e.g., Kafka for lab result updates).

3. Component Diagram (Level 3)

• Components (Example: EHR Service):
  • Patient Record Manager: Creates/updates patient profiles.
  • Medication Management: Tracks prescriptions and interactions.
  • Clinical Decision Support: Provides evidence-based treatment recommendations.
  • Audit Logging: Records access and modifications for compliance.

4. Code Diagram (Level 4)

• Technical Details:
  • Frameworks: Spring Boot (Java) for backend services, Angular for web UI.
  • APIs: RESTful endpoints with OAuth2 authentication.
  • Data Storage: PostgreSQL for relational data, MongoDB for documents.

Key Relationships

• Integration Points:
  • HIS → Lab Systems: Sends test orders, receives results.
  • HIS → Pharmacy Systems: Transmits prescriptions, checks drug availability.
  • HIS → Billing Systems: Exchanges insurance eligibility and payment data.

Design Principles

• Security: Role-based access control (RBAC), HIPAA compliance, data encryption.
• Scalability: Microservices architecture allows independent scaling of critical components.
• Resilience: Redundant databases and failover mechanisms ensure continuous operation.