ADVANCES IN EM

Next generation point of care device in Medicine Series: Digital Stethoscope

wongkb

Dr WONG Kwun Bun
Associate Consultant, PWH, A&E

Introduction

One of the most powerful tools available to physicians is the stethoscope. It is one of the symbol of a doctor. The stethoscope first emerged in the year 1818, invented by a French physician, René Laennec (1) . The word stethoscope comes from the Greek words stethos, meaning chest, and skopein, meaning to explore. 

A digital stethoscope is able to convert an acoustic sound to electronic signals, which can be further amplified for optimal listening. The digital stethoscope is made up of 3 different modules, data acquisition, preprocessing, and signal processing. First, data acquisition is responsible for filtering, buffering, and amplification of the auscultated sounds, as well as conversion of the acoustic sound to a digital signal by a microphone and a piezoelectric sensor. Second pre-processing module filters the digital signal and removes any artifacts. Thirdly, a signal-processing module, which will package the information in a higher-order classification and cluster the data for a clinical diagnostic decision by computer or clinical apps. 

 

Clinical applications and advantage 

Increased precision and audible advantage by digital stethoscope, it is useful in the era of obesity. Also it may be useful in our A&E noisy environment and pre-hospital setting (6). The use of digital stethoscopes and the capability to transmit the heart sounds wirelessly, there is potential to develop and advance the field of telemedicine (3). Recent research using digital stethoscopes may be useful in diseases that are difficult to diagnose by traditional stethoscope such as pulmonary hypertension (PH) (4) and obstructive coronary heart disease (5). It may be a very important screening tool for the early detection of cardiac or respiratory illnesses and guide for advanced scan. Finally, doctors with hearing issues, especially senior doctors, can benefit from electronic stethoscopes. 

Limitation

With the competition and availability of handheld ultrasound, the development of digital stethoscope is not as fascinating as ultrasound. The main factors limiting the electronic stethoscope are not only the diagnostic accuracy that the computer based system can provide, but more importantly the system’s reliability, robustness and transportability.

Reference 

  1. Roguin A. Rene Theophile Hyacinthe Laënnec (1781–1826): the man behind the stethoscope. Clin Med Res. 2006;4(3):230–235

  2. Leng S, Tan RS, Chai KT, Wang C, Ghista D, Zhong L. The electronic stethoscope. Biomed Eng Online. 2015;14:66. 

  3. Lakhe A, Sodhi I, Warrier J, Sinha V. Development of digital stethoscope for telemedicine. J Med Eng Technol. 2016;40(1):20–24

  4. Kaddoura T, Vadlamudi K, Kumar S, et al. Acoustic diagnosis of pulmonary hypertension: automated speech-recognition-inspired classification algorithm outperforms physicians. Sci Rep. 2016;6:33182.

  5.  Makaryus AN, Makaryus JN, Figgatt A, et al. Utility of an advanced digital electronic stethoscope in the diagnosis of coronary artery disease compared with coronary computed tomographic angiography. Am J Cardiol. 2013;111(6):786–792.

  6. Kang S-H, Joe B, Yoon Y, Cho G-Y, Shin I, Suh J-W. Cardiac auscultation using Smartphones: pilot study. JMIR Mhealth Uhealth. 2018;6(2):e49.