A systematic review and conceptual hybrid framework for integrating blockchain and internet of medical things in secure healthcare systems

Internet of Medical Things (IoMT) deployments generate continuous streams of sensitive patient data, yet centralised storage remains exposed to single points of failure, unauthorised disclosure, and tampering. Blockchain offers an immutable, auditable substrate, but pairing it with resource-constrained devices raises concerns around throughput, latency, energy, and scalability. This paper presents a systematic literature review of peer-reviewed studies published between 2018 and 2025, selected under a PRISMA-aligned protocol across five databases, with all screening decisions double-rated (κ = 0.80). The review organises recurring technical gaps into a structured taxonomy, from which we derive a conceptual hybrid architecture combining an IoMT perception layer, an edge-gateway tier, a permissioned blockchain running Practical Byzantine Fault Tolerance (PBFT) consensus, and an Interplanetary File System (IPFS) off-chain store. The device–gateway key exchange is verified in ProVerif under a Dolev-Yao adversary, establishing session-key secrecy, injective agreement, and forward secrecy over unbounded sessions. Cryptographic costs measured on constrained hardware yield 35.7–141.4 ms commit latency and 707–2,798 transactions per second across a set of 4–31 validators, with an on-chain to off-chain storage ratio near 1:20. Cryptography accounts for only 2.8–10.7% of commit latency, confirming that network delay is the binding constraint. The contribution over prior surveys is a reproducible protocol, an explicit gap analysis, a unified notation and threat model, a machine-checked proof of authentication, and an analytical committee-sizing rule.