Design of a Microcontroller-Based Patient Vital Signs Monitoring System for Primary Health Care Centres in Kwara State

Primary health care centres in Kwara State, North Central Nigeria, frequently face shortages of trained nursing staff and medical monitoring equipment, resulting in delayed detection of deteriorating patient conditions. This project presents the design of a microcontroller-based patient vital signs monitoring system capable of measuring heart rate, blood oxygen saturation, body temperature, and blood pressure, and displaying readings in real time on an LCD interface. The system employs a MAX30100 pulse oximetry sensor, a DS18B20 digital temperature sensor, and a non-invasive blood pressure sensor module, all interfaced with an Arduino Nano microcontroller. An alert mechanism triggers a buzzer and sends an SMS via a SIM800L GSM module when any vital parameter falls outside predefined safe ranges. The system was validated against a clinically certified portable patient monitor in a simulated clinical environment using 30 human volunteers. Comparative readings showed a mean absolute error of 1.8 beats per minute for heart rate, 1.4 percent for SpO2, and 0.4 degrees Celsius for temperature. A data-logging feature records timestamped readings to a microSD card for medical record-keeping purposes. Fabrication cost of the prototype was estimated at approximately 18,000 Naira, significantly lower than equivalent commercial monitoring equipment. The study recommends integration with a Raspberry Pi-based hub for multi-bed monitoring across ward units. Keywords: vital signs monitoring, patient health, microcontroller, primary health care, Kwara State