Blockchain-based Electronic Health Record (EHR) System

Abstract

Conventional Electronic Health Record (EHR) systems improve access to patient information but commonly depend on centralized databases, creating concerns related to single points of failure, unauthorized access, limited transparency, interoperability, and patient control. This project develops a blockchain-based EHR management system that combines Ethereum, Solidity smart contracts, Angular, MetaMask, Ethers.js, Hardhat, Anvil, and the InterPlanetary File System (IPFS). The system supports Administrator, Doctor, and Patient roles. MetaMask is used for wallet-based authentication; smart contracts manage registration, appointments, medical-record references, and access permissions; and IPFS stores healthcare documents while only cryptographic hash references are maintained on the blockchain. The application was implemented and tested in a local blockchain environment. The thesis reports successful operation of user registration, authentication, appointment scheduling, medical record upload, permission management, and authorized record retrieval. The resulting architecture provides a patient-centric workflow in which access can be granted or revoked and important healthcare transactions are recorded on the blockchain to provide a transparent audit trail. The prototype demonstrates the feasibility of combining blockchain and decentralized storage for secure and transparent EHR management.