WiraChain: a blockchain and FHIR-based platform for improving clinical data interoperability in healthcare

Interoperability challenges in healthcare frequently lead to fragmented patient records and duplicated procedures, negatively affecting continuity of care and operational efficiency. Although multiple theoretical frameworks and standards have been proposed to address these issues, practical and fully implemented solutions enabling secure and controlled data exchange remain limited. To address this gap, we developed Wirachain, a decentralized application that integrates blockchain technology with the HL7 FHIR standard for electronic health record management. The system enables patient-controlled permission granting and revocation, incorporates authentication and role-based access control, and supports persistent storage using both FHIR-compliant and traditional databases. Validation was conducted using synthetically generated clinical data and stress-testing scenarios to assess system performance under load. The results demonstrate that the proposed application can reliably manage access permissions and clinical data exchange across interoperable components. The system maintained efficient operation and secure data handling under simulated clinical workflows and increased load conditions. These findings indicate that fully implemented blockchain-based solutions can effectively bridge the gap between conceptual interoperability frameworks and practical healthcare applications. Wirachain illustrates the feasibility of combining blockchain and FHIR standards to support secure, patient-centered, and interoperable clinical operations.