### Summary box #### What are the new findings? #### How might it impact on healthcare in the future? COVID-19 pandemic has presented us with unique challenges. One of them is evaluating patients with lung pathologies. Wearing personal protective equipment (PPE) (especially coveralls), because of covering of ears, precludes use of one of the time-tested tools of patient assessment—the stethoscope. Because of this, rapid assessment of patients at multiple points of time is affected. To overcome this, use of bedside ultrasonography has been advocated1 ; however, ultrasonography is costly and requires additional training. Also, the availability of ultrasonography is not universal. Besides, there is no easy alternative for detection of wheeze and evaluation of symmetry of breath sounds, both of which have therapeutic implications. One of the ways around is to use electronic stethoscopes, but they are too costly for mass deployment, with a price averaging around US$500 from the established brands.2 3 We have developed a low-cost system to convert user’s existing stethoscope to a digital one without damaging it: do-it-yourself (DIY) digital stethoscope. The system consists of a microphone attached to the stethoscope, custom-built Android-based app available on Google Play Store4 and headphones. We present here the development and validation of this frugal innovation. A digital stethoscope requires a sensor to collect the sounds, a processor and a playback system. We tried various permutations and combination of multiple sensors (electret vs micro-electro-mechanical system vs piezoelectric) in different configurations (directly applied to skin vs within the chestpiece vs within the tubing of the stethoscope vs at the ear tip). For our model, we decided to use an electret microphone (eg, collar mic) at the earpiece of the stethoscope. …

中文翻译：

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低成本电子听诊器的开发和验证：DIY数字听诊器

### 摘要框#### 有哪些新发现？#### 它对未来的医疗保健有何影响？COVID-19 大流行给我们带来了独特的挑战。其中之一是评估患有肺部病变的患者。佩戴个人防护装备 (PPE)（尤其是工作服），因为耳朵被遮盖，因此无法使用经过时间考验的患者评估工具之一——听诊器。因此，在多个时间点对患者的快速评估受到影响。为了克服这个问题，提倡使用床边超声检查 1 ；然而，超声检查费用昂贵，并且需要额外的培训。此外，超声检查的可用性并不普遍。此外，对于喘息的检测和呼吸音对称性的评估，没有简单的替代方法，这两者都具有治疗意义。一种解决方法是使用电子听诊器，但其大规模部署成本太高，知名品牌的平均价格约为 500 美元。2 3 我们开发了一种低成本系统，将用户现有的听诊器转换为数字听诊器。一种不会损坏它：自己动手 (DIY) 数字听诊器。该系统由连接到听诊器的麦克风、Google Play Store4 上提供的基于 Android 的定制应用程序和耳机组成。我们在这里展示了这种节俭创新的发展和验证。数字听诊器需要一个传感器来收集声音、一个处理器和一个播放系统。我们尝试了不同配置（直接应用于皮肤、胸件内、听诊器管内、耳塞）的多种传感器（驻极体、微机电系统、压电）的各种排列和组合。对于我们的模型，我们决定在听诊器的听筒上使用驻极体麦克风（例如，领式麦克风）。…