Convergence of blockchain and IoT for managing decentralized medical records

This research introduces a strategy to integrate blockchain technology with Internet of Things. Amalgamation of blockchain technology and Internet of Things is vital as one of them offers to connect patients remotely and other provides a higher level of privacy, secure decentralized system and immutable data storage. The studies in the past were merely storing patient vitals overlooking the significance of medical reports. A medical history remains incomplete without storing medical reports. This research is offering a technique to store both medical reports and patient vitals on the blockchain ledger. To prevent overwhelming the blockchain network, a node.js application is developed which store the medical reports on the IPFS server and retrieve their corresponding hash values. Thereafter, these hash values along with the patient details and vitals are then transmitted to blockchain ledger. This study makes use of MAX30100 and DS18B20 sensors to monitor heart rate, blood oxygen and body temperature. ESP32 microcontroller is used to integrate these sensors and fetch their data periodically. Hyperledger fabric blockchain framework is used for maintaining the ledger and Hyperledger caliper tool is used to evaluate the overall performance of the proposed system. The performance is computed on three key parameters: reliability, throughput and latency. Reliability is evaluated in two phases, one with caliper tool and another with real RPM (Remote Patient Monitoring) unit. In the first phase, caliper tool transmitted 1500 transactions which are then verified by reading the ledger. In the second phase, RPM unit transmitted 480 transactions to blockchain ledger within 8 h. This study confirms that all transmitted transactions are successfully recorded on the blockchain ledger without any loss or failure. Medical reports submitted on IPFS server are also cross verified and found to be intact. The second experiment is carried out using two, four and eight workers attempting to execute 1000 transactions cumulatively at 40, 80 and 160 TPS (Transactions Per Second) respectively. It is noteworthy that when caliper tool is configured to execute transactions at 40 and 80 TPS, the achieved TPS remain unchanged. In contrast to this, when caliper tool is configured to send transactions at 160 TPS it could only achieve the transaction rate of 94 TPS. The peak of average latency is recorded as 0.45 s when transactions are executed at 94 TPS. The lowest latency is observed as 0.24 s at 40 TPS. As far as the throughput is concerned, the highest throughput is observed as 91.4 TPS when the caliper tool is attempting to execute transactions at 94 TPS. The system could achieve throughput of 39.8 and 79.4 TPS when caliper attempts to send transactions at 40 and 80 TPS respectively. The unique contribution of this study is to converge Hyperledger fabric blockchain framework, InterPlanetary File System (IPFS) and Internet of Things health sensors to develop a comprehensive solution for storing and retrieving the medical histories of remote patients, effectively managing both patient vitals and complex medical reports without compromising reliability and overall throughput.