Development of a Simple Electrocardiograph Circuit for Use in Rural Clinics in Plateau State

Cardiovascular disease detection in rural Nigerian communities is severely limited by the unavailability and high cost of electrocardiograph machines in remote clinics, creating a diagnostic gap that contributes to late presentation and poor outcomes. This study develops a simple, single-lead electrocardiograph circuit prototype designed for operational feasibility in rural clinics in Plateau State. The circuit was designed around an instrumentation amplifier (INA128) for differential ECG signal acquisition, a bandpass filter network targeting the 0.05 to 150 Hz clinical ECG band, a 50 Hz notch filter for power line interference rejection, and an Arduino Nano microcontroller for analogue-to-digital conversion. Signal output was displayed on a 2.8-inch TFT LCD and simultaneously transmitted via Bluetooth to a paired Android smartphone running a custom visualization application. The total fabrication cost was estimated at under eight thousand naira using locally sourced components. Signal quality was evaluated on twenty volunteers by comparing the prototype trace with a standard clinical ECG machine at a rural clinic in Barkin Ladi LGA. Visual assessment of P-QRS-T waveform morphology by a consultant cardiologist rated ninety-three percent of prototype traces as clinically interpretable for basic arrhythmia screening purposes. Common contact artifacts were identified and partially mitigated by electrode preparation protocol refinement. The study recommends further miniaturization, clinical validation on cardiac patients, and regulatory pathway assessment with NAFDAC before wider deployment in Plateau State rural clinics. Keywords: electrocardiograph, single-lead ECG, rural clinic, cardiovascular screening, Plateau State.