Design and development of prototype for obtaining indirect ECG Bipolar Lead II through the photoplethysmograph signal

This work consists in designing and developing a prototype that obtains an approximation of a normal ECG Lead II signal by means of a normal Photoplethysmographic signal (PPG). These signals are of vital importance for the heart functioning and are obtained by means of an only one optoelectronic transducer. This transducer will offer patients the necessary comfort that is not found in similar and traditional methods. Later, a low cost electronic prototype was made for the PPG signal conditioning, its respective analog-to-digital conversion and the data sending via serial port to a PC computer. Also, a Windows Graphical User Interface (GUI) has been developed in MS Visual C++ 6.0 to allow the PPG signal processing required for the obtaining of ECG Lead II signal, and the corresponding visualization of these signals on a PC monitor. It is have been possible by means of using software algorithms for the implementation of a recursive autoregressive (RARX) model that converts PPG signal to ECG Lead II signal, considering that both signals are repetitive signals and have the same repetition frequency. This developed work (hardware and software) is of a low cost with regard to traditional Medical Monitoring equipment and appears as a great alternative to be used in the medium and low complexity medical assistance services in Peruvian remote Health Centers, improving their patients´ life quality. Likewise, we are contributing to the National Biomedical Instrumentation development in Peru.