Electronic stethoscope – a didactic and low cost acquisition system for auscultation

Abstract

Background: This paper presents an electronic stethoscope model for cardiac auscultation, that adds innovative functionality to the conventional stethoscope, nominated "Electronic Stethoscope". Among the Electronic Stethoscope functionalities, can be cited the volume adjust in order to facilitate the hearing of the heart pulses, the graphic presentation of the heart beat sound waveforms, from a monitor, and the store of the cardiac auscultation data in a memory card for future analysis. It is believed that this additional functions, nonexistent in conventional stethoscopes, can contribute in the identification of pathology anomalies by the doctors and medicine students, growing the diagnoses trusting rate. Beyond that, the stored data in the equipment can be visualized and listened, without the necessity of the patient presence, characteristic that enables the build of a database, for example, of indicative signals of pathologies that could be used in class and practicing. With this equipment it is also possible to make adjusts on amplitude and length of the graphics (zoom), for a better details visualization. Undesirable ambient sounds can also be mitigated by the use of low-pass digital filters of IIR type implemented on the stethoscope software. This equipment has also a graphic resource for the identification of patient’s heart rate similar of the gestational ultrasound equipment. Results of interviews with doctors and medicine students shows that the equipment have practical applicability, either in clinic or classroom, and extremely intuitive mode of operation, which would require no prior specific training.