Design of a Microcontroller-Based Automatic External Defibrillator Training Device for Community First Responders in Lagos

Out-of-hospital cardiac arrest survival rates in Lagos are critically low, partly due to the near-complete absence of bystander defibrillation, which requires community familiarity with automated external defibrillator devices. This study designs a microcontroller-based AED training device for community first responder training in Lagos, replicating the functionality and user interface of a standard AED without delivering a real therapeutic shock. The device uses an Arduino Mega microcontroller, a recorded voice instruction module (ISD1820), an LED indicator panel replicating AED status indicators, a simulated electrode pad training kit, and a rhythm analysis simulation module displaying pre-programmed shockable and non-shockable rhythm scenarios on a small LCD. The training sequence guides the user through power on, pad placement, rhythm analysis waiting period, shock advisory, and simulated shock delivery steps with identical timing and audio prompts to a reference Philips Heartstart AED. A shockable rhythm scenario simulator presents ventricular fibrillation and ventricular tachycardia rhythm patterns and confirms appropriate shock delivery by the trainee. A non-shockable scenario confirms trainee compliance with no-shock advisory. Skill retention testing was conducted following a two-hour training session with forty community members in Mushin LGA, evaluating correct AED sequence completion rate and shock delivery decision accuracy. Correct sequence completion rate was 88 percent immediately post-training and 76 percent at four weeks follow-up without refresher training. The study recommends mass production and deployment of training units to community development associations and market leader groups in Lagos LGAs. Keywords: AED training device, community first responder, cardiac arrest, defibrillator, Lagos State.