Development of a Real-Time Integrated Electrocardiogram (ECG) and Reflectance-Based Pulse Oximetry System

Abstract

Cardiovascular disease (CVD) is one of the primary causes of sudden cardiac death in Africa. Cardiac anomalies can be detected using an  electrocardiogram (ECG), but the most difficult aspect of CVD is detection during its early stages. In addition to monitoring the heart  using ECG, heart rate and blood oxygen saturation (SpO2) are also important indicators related to the heart-pulmonary system since the  two variables provide an indication of the overall functionality of the heart. Insufficient technologies for monitoring these parameters  have been documented (especially in LMIC regions and rural areas) leading to late detection. The objective of this study was to create a low-cost 3-lead ECG signal detecting system and a pulse oximeter that could detect the likelihood of CVD in real time. The design of the  device with LCD and DSO138 oscilloscope output is described in this study. Five units were used to create the device: ECG electrodes  attached to an AD8232 ECG sensor module; ECG filter system; DSO138; MAX30100 heart rate and oxygen saturation sensor, and a power  source. The results revealed that the portable device interprets the ECG signal from the 3-lead ECG system satisfactorily. The pulse  oximeter system is made from a MAX30100 sensor which displays patient heart rate and oxygen saturation levels on an alphanumeric  LCD screen. The designed system was successfully compared against a standard 3-lead ECG system and an internationally approved  Oxiline Pulse 7 Pro pulse oximeter. The system developed in this study was able to function according to the design, measuring heart  rate, and blood oxygen saturation, and displaying ECG waveforms. According to the test findings using the designed pulse oximeter  system, heart rate measurements resulted in an error value of -0.70% and -0.21% in males and females, respectively, as well as 1.28% and  0.10% for SpO2 results in males and females, respectively after comparison. For a much better assessment of CVD, there is a need to  integrate the system with a GSM module to allow for the transmission of ECG signals, heart rate, and SpO2 patient data through mobile  phones and the internet for remote and automated monitoring.