System Architecture

CARE-Link is built on a service-oriented architecture that decouples the EHR, messaging, and AI components.

High-Level Components

The system consists of three main pillars:

1. User Interfaces

   • Clinician Portal: React-based web front-end.
   • Patient Interface: WhatsApp chatbot.

2. Backend Services

   • EHR Backend: Laravel (PHP) web service handling user management and records.
   • Chatbot Service: Python FastAPI application processing WhatsApp messages.

3. Data Storage

   • PostgreSQL: Stores patient demographics, vitals, and structured medical records that require relational integrity.
   • MongoDB (Azure Cosmos DB): Stores unstructured chat logs and conversation history.

graph TD
    A[Patient (WhatsApp)] <-->|Meta Cloud API| B[Chatbot Service (FastAPI)]
    B <-->|Queries| C[LLM (OpenAI)]
    B <-->|Reads/Writes| D[MongoDB (Chat Logs)]
    B <-->|Updates| E[PostgreSQL (Medical Records)]
    F[Clinician (Web Dashboard)] <-->|HTTPS| G[EHR Backend (Laravel)]
    G <-->|Reads/Writes| E
    G <-->|Request Summary| B

Microservices Design

• EHR Platform: Deployed as an Azure App Service.
• Chatbot Service: Hosted as an Azure Function for event-driven execution.
• Communication: Secure HTTP/2 channels with TLS encryption.

Extensibility

The architecture allows for new agents (e.g., nutrition coach) to be plugged in via standard APIs. The use of widely adopted open-source stacks (React, Laravel, FastAPI) ensures maintainability.