Medichain

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Inspiration

The inspiration behind Medichain comes from a heartbreaking, real-life event. A young boy from my neighborhood in Douala was rushed to the hospital after an accident. He needed an urgent blood transfusion, but the doctors didn’t know his blood type. His medical record — a paper booklet — had been misplaced during a previous hospital visit and wasn’t available. Worse, parts of his records were scattered across different hospitals he had visited before, none of which were digitally connected. A wrong blood transfusion was administered, and he didn’t survive.

This tragedy exposed a painful truth: in many parts of Cameroon and across Africa, paper-based records are not only fragile — they are often misplaced, damaged, or split between different facilities, making continuity of care extremely difficult. Medichain was created to solve this — to ensure your medical information follows you, even when you cannot speak for yourself.

What it does

Medichain is a blockchain-powered medical record platform that gives patients control over their health data while ensuring doctors can access emergency information instantly.

Patients can securely store and manage their medical history.

Doctors can view emergency details (like blood type, allergies, weight, etc.) without needing prior permission.

Admin access is restricted to a single authorized MetaMask wallet.

Role-based login ensures different experiences for patients, doctors, and the admin.

Full health history is only accessible if the patient grants permission.

Future versions will include epidemic prediction based on anonymized data.

How we built it

We built Medichain using:

React + TypeScript for the frontend

Solidity smart contracts for handling secure storage and access logic

MetaMask + ethers.js for blockchain interaction

Hardhat for development and deployment on the Sepolia testnet

Challenges we ran into

Handling role-based access securely from MetaMask without a centralized user database

Designing a way for doctors to access emergency info without compromising full privacy

Overcoming MetaMask errors related to contract data decoding

Ensuring Sepolia testnet deployment worked smoothly with real MetaMask addresses

Building trust in a blockchain system in a real-world, high-stakes domain like healthcare

Accomplishments that we're proud of

Built a working, secure MVP where patients, doctors, and admins all have distinct, meaningful roles

Enabled instant emergency access for doctors

Implemented MetaMask-based auth without email/password

Brought to life a real-world solution with potential impact in low-resource settings

What we learned

The importance of real-world usability when building for communities with limited infrastructure

How to integrate blockchain, TypeScript, MetaMask, and smart contracts into a unified platform

Deepened our understanding of privacy vs. accessibility trade-offs in medical tech

Learned to handle blockchain deployment, role logic

That a powerful story behind a project can drive not just code — but change

What's next for Medichain

Roll out pilot programs with clinics in Cameroon and other African countries

Finalize and activate the $2/year subscription model after launch

mobile-first UI, and biometric login for future versions

Collaborate with public health organizations to use anonymized data for epidemic prediction

Expand interoperability with hospitals and systems lacking digital infrastructure

Built With

• css3
• html5
• react
• solidity
• supabase
• typescript