Development of a Bluetooth-Based Vital Signs Monitoring Wristband Prototype for Patients in Rural Clinics in Borno State

Remote rural health clinics in Borno State, North East Nigeria, face critical shortages of clinical monitoring equipment, leading to delayed detection of deteriorating patient conditions and preventable deaths. This project developed a Bluetooth-based vital signs monitoring wristband prototype capable of measuring heart rate, blood oxygen saturation (SpO2), and skin temperature, designed for deployment in resource-limited clinic settings. A MAX30102 pulse oximeter and heart rate sensor, an MLX90614 infrared temperature sensor, and a Nordic nRF52832 Bluetooth Low Energy microcontroller were integrated into a wristband form factor with a 180mAh lithium polymer battery. Sensor data were wirelessly transmitted to a paired Android application developed in Android Studio, which displayed real-time values with alert thresholds configurable by the attending nurse. The prototype was validated against a certified Masimo Radical-7 pulse oximeter and an Omron digital thermometer in a controlled setting using 15 volunteer participants. Heart rate agreement showed a mean absolute error of 2.8 beats per minute. SpO2 agreement was within plus or minus 2 percent across the 95 to 100 percent range. Temperature measurement error was below 0.3 degrees Celsius. Battery life was 18 hours at continuous one-second sampling rate. Bluetooth range was 9.2 metres in indoor test conditions. The study recommends adding blood pressure estimation capability using photoplethysmography analysis and incorporating an onboard buzzer alarm for clinics where the Android tablet may not always be attended by staff.

Keywords: vital signs monitoring, Bluetooth wearable, healthcare technology, Borno State, embedded systems