The limited sensitivity of human hearing to the need to evaluate certain low-frequency sounds (below 50 Hz) served as an incentive to develop an electronic device that surpasses a conventional stethoscope in its characteristics and complexity. In January 2018, Medical Devices: Evidence and Research published an overview of the possibilities and benefits of auscultation performed with an electronic stethoscope. The work was performed by clinicians at the Nassau University Medical Center and the School of Medicine at Hofstra, New York, USA.
The digital stethoscope consists of three modules: data acquisition, pre- and post-processing for listening and evaluation. Unlike an acoustic stethoscope, digital device transducers have a wider range of perception, allowing you to select different modes of frequency response. The capacitive noise reduction transducer is designed not only to eliminate, but also to selectively amplify (up to 100 times) the necessary components of the sound (for example, heart sounds). Separate software algorithms make it possible to extrapolate the received sounds to the work of the lungs. Actually, the use of electronic auscultation involves registration and increases the objectivity of the data obtained. Digital stethoscopes equipped with a bluetooth module can transmit auscultation data directly to a remote processing unit.
In addition to improved accuracy and audibility, electronic stethoscopes have shown benefits in screening for coronary heart disease. Turbulence of blood flow in the coronary vessels of the heart is manifested by intracoronary murmurs that are not heard with an acoustic stethoscope. The results of studies show that the use of a digital stethoscope makes it possible to detect coronary heart disease with stenotic changes >50% in 89.5% of cases (p<0.001). The efficiency of processing electronic auscultation data using a computer algorithm to detect abnormal lung sounds according to research data reaches 85%.
