Automated First Aid Kit with Internal UV-C Sterilisation: Design, Construction, and Functional Verification

This report documents the design, construction, and functional verification of an Automated First Aid Kit equipped with an internal ultraviolet germicidal (UV-C) sterilisation system. The project was undertaken as a diploma final year project in Biomedical Engineering at Kyambogo University, Kampala, Uganda, during the 2022/2023 academic year, under the supervision of Dr. Kafeero Hussein.

The system integrates an 8W low-pressure mercury germicidal lamp operating at 254 nm, an ATmega328P microcontroller on an Arduino Nano board, an HC-SR04 ultrasonic proximity sensor for automated lid-closure detection, and a relay module for lamp switching. UV-C dose calculations incorporating a lamp conversion efficiency of 35% yield a UV-C irradiance of approximately 1.35 mW/cm² and a calculated exposure time of 35 seconds, corresponding to a delivered dose of approximately 47 mJ/cm² — exceeding the EPA's 40 mJ/cm² minimum disinfection threshold.

The prototype successfully demonstrated automated lamp activation and deactivation in response to lid closure, stable LED status indication, and consistent timer operation. This work is presented as a proof of concept: quantitative measurement of UV-C irradiance and microbial reduction testing were outside the resource scope of this iteration and are identified as priorities for future work.

This document was originally submitted in July 2023 in partial fulfilment of the requirements for the Diploma in Biomedical Engineering, Kyambogo University. It was revised in March 2026 to correct technical errors in the UV-C intensity calculation, standardise citations, and more accurately characterise the scope and limitations of the prototype. It is made publicly available to document the proof-of-concept work of the named authors.