Piezoelectric Heart Monitor

Cardiovascular diseases are the leading cause of death globally. The increase in chronic diseases, such as Diabetes Mellitus and hypertensive heart disease, added to the ageing population, brings in risk factors that increase these statistics. In this scenario, studies related to these diseases are fundamental for the prevention of deaths and for improvements in quality of life. For this purpose, a cardiac monitor was constructed using a piezoelectric transducer as the sensor. The signal was conditioned using Rail-to-Rail amplifiers and digitized by a PIC microcontroller. A computer controls and receives data from the microcontroller through an interface developed on Qt. When data is received, the application presents a seismocardiogram (SCG) waveform on a real-time chart, allowing the user to save data to a file and estimate the heart rate. The developed software also applies a digital filter to reduce interferences in frequencies above 55 Hz. Recorded data were verified using MatLab^®. The characteristic points of the SCG were identified in the graphs presented on interface.