Remote heart rate monitoring system based on phonocardiography

A prototype of a simple and noninvasive system to remotely monitor the real-time heart rate of patients or individuals based on phonocardiography, the study of heart sounds has been developed. This system consists of five modules. The first module, namely the front-end module is used to acquire and capture heart sound signals. Signal transmission and reception is done wirelessly using the FM transmitter & receiver module. The received signal is then inputted into one of the following modules, either the determining heart rate module or the plotting phonocardiogram module, which both utilize a separate PIC16F877 micro controller. For the determining heart rate module, the received signal is first sent to a voltage comparator before being inputted into the PIC. This PIC then calculates the corresponding heart rate. On the other hand, the plotting phonocardiogram module samples and digitizes the received signal at a sampling rate of approximately 25 kHz. Both modules serially transmit 8-bit data with start and stop bits at a baud rate of 4800 bits/s to the computer via the RS232 interface. The software development module that uses Visual Basic 6.0 displays the heart rate for the determining heart rate module and displays the respective phonocardiogram (PCG waveform) for the plotting phonocardiogram module.