Development of smartphone-based stethoscope system

Heart diseases associated with living conditions, such as coronary heart disease and hypertension are becoming more and more complex. If heart condition didn´t get long-term and real-time monitoring and diagnosis, it may induce sudden heart disease. As the heart auscultation is one of the most fundamental ways to evaluate the heart functions, a stethoscope can be used to auscultate respiratory sounds and heart sounds, and diagnose most of the cardiopulmonary disorders and other diseases. Therefore, we tried to develop a smartphone-based stethoscope system that can record heart sound and calculate heart rate from the sound. The proposed system is designed to acquire the heart sounds using the iPhone or the iPad applications, record the acquired data on a real-time basis and display the heart sounds in a graph, and allow listening to the acquired sounds. Also, the peak of the heart sounds is identified on a real-time basis to determine the heart rate, thereby quantifying the information related to the cardiovascular system. The system can be utilized under various environments depending on the sensor type such as built-in microphones within the smartphones, external microphones, and electronic stethoscopes. In subsequent studies, we plan to utilize the detected heart sound peaks to display the magnitude of the heart sounds, and apply various analysis methods to quantify the information related to cardiac activities.