🏥 HospitalSanitizationTracker

A blockchain-based DApp for traceability of hospital sanitization activities

Project for the Blockchain and Cryptocurrencies course – University of Bologna
Proposal 7 – DLTs for Traceability in Supply Chain (AnaNSi Research Group)

---

Table of Contents

1. Description
2. Tech Stack
3. Architecture & Project Structure
4. Smart Contract – Features
5. Frontend DApp – Features
6. Installation & Usage
7. Deployed Contract
8. Author

---

Description

An Ethereum smart contract-based system that allows authorized operators to register and certify sanitization operations of hospital areas.

Every event is recorded immutably on the blockchain and can be queried at any time, guaranteeing transparency and non-repudiation of data.

---

Tech Stack

Technology	Version	Role
Solidity	0.8.20	Smart contract language
Hardhat	2.28.0	Development / test / deploy framework
Ethers.js	v6	Contract interaction from frontend
Node.js	v22	JavaScript runtime
Infura	–	RPC Provider (Sepolia)
MetaMask	–	Wallet for transaction signing
Ethereum Sepolia	Testnet	Deployment network

---

Architecture & Project Structure

HospitalSanitizationTracker/
├── .github/
│   └── workflows/
│       └── ci.yml                       # GitHub Actions CI pipeline
├── contracts/
│   └── SanitizationTracker.sol          # Main smart contract
├── scripts/
│   └── deploy.js                        # Local deploy script
├── ignition/
│   └── modules/
│       └── SanitizationTracker.js       # Hardhat Ignition module (testnet deploy)
├── test/
│   └── SanitizationTracker.test.js      # Test suite (14/14)
├── frontend/
│   ├── index.html                       # DApp web interface
│   ├── app.js                           # DApp logic + contract interaction
│   └── style.css                        # Styles
├── Photos/
│   └── logo.png
├── artifacts/                           # Compilation output (gitignored)
├── cache/                               # Hardhat cache (gitignored)
├── hardhat.config.js
├── package.json
├── .env.example                         # Environment variables template
└── .gitignore

---

Smart Contract – Features

The SanitizationTracker.sol contract implements the following:

Data Structures

Struct	Main Fields
Area	id, name, active, exists
Operator	wallet, name, active, exists
SanitizationEvent	areaId, operatorAddress, timestamp, outcome, notes

Main Functions

Function	Access	Description
registerArea(id, name)	onlyAdmin	Register a new area
setAreaActive(id, active)	onlyAdmin	Enable/disable an area
registerOperator(wallet, name)	onlyAdmin	Register a new operator
setOperatorActive(wallet, active)	onlyAdmin	Enable/disable an operator
sanitize(areaId, outcome, notes)	onlyActiveOperator	Record a sanitization event
getAreaEvents(areaId)	public	Returns full event history
getLastSanitization(areaId)	public	Returns last event
getEventCount(areaId)	public	Returns event count

Access Modifiers

• onlyAdmin → deployer address only
• onlyActiveOperator → registered and active operators only

On-Chain Events

• AreaRegistered(id, name)
• OperatorRegistered(wallet, name)
• AreaSanitized(areaId, operator, timestamp, outcome)

---

Frontend DApp – Features

The frontend/ folder contains a full web DApp that connects to the contract via MetaMask.

Roles

Role	Description
Admin	Deployer account; can register areas and operators
Operator	Account registered by admin; can record sanitizations
Guest	Unrecognized account; read-only access

The DApp automatically detects the role by reading the admin address and the operators mapping directly from the contract.

Interface Sections

#	Section	Required Role	Function
1	Header	–	MetaMask connection, connected address, detected role
2	Register Area	Admin	Register a new area (ID + Name)
3	Register Operator	Admin	Register an operator (Wallet Address + Name)
4	Record Sanitization	Operator	Record event (Area ID, Outcome, Notes)
5	Area Status	All	Display area data + last sanitization
6	Area Events	All	Full event history for an area

---

Installation & Usage

Prerequisites

• Node.js v22+
• MetaMask installed in the browser
• Sepolia account with test ETH (Sepolia Faucet)

Setup

git clone https://github.com/FrancescoCastaldi/HospitalSanitizationTracker.git
cd HospitalSanitizationTracker
npm install
cp .env.example .env
# Edit .env with your INFURA_API_KEY and PRIVATE_KEY

Commands

# Compile the contract
npx hardhat compile

# Run tests
npx hardhat test

# Deploy to Sepolia (Hardhat Ignition)
npx hardhat ignition deploy ignition/modules/SanitizationTracker.js --network sepolia

Start Frontend

npx serve frontend
# or use the "Live Server" extension in VS Code

Open the browser at http://localhost:3000 and select the Sepolia network in MetaMask.

Typical Usage Flow

1. Connect with Admin account (deployer)
   └→ Register an area  (e.g. ID=101, Name="Operating Room")
   └→ Register an operator (wallet of 2nd MetaMask account)

2. Switch account in MetaMask → Operator
   └→ Record a sanitization (Area 101, Outcome: OK, Notes: ...)

3. With any account
   └→ Check Area Status and Area Events to verify the history

---

Deployed Contract

Field	Value
Network	Ethereum Sepolia Testnet
Address	0x679C6625f9479cf3b711F7a246C8F7a6655E4517
Deploy Date	February 21, 2026
Etherscan	View on Sepolia Etherscan

---

Author

Francesco Castaldi
University of Bologna – Blockchain and Cryptocurrencies Course

---

Project developed for academic purposes