The respiratory sound features of COVID-19 patients fill gaps between clinical data and screening methods

Ying hui Huang; Si jun Meng; Yi Zhang; Shui sheng Wu; Yu Zhang; Ya wei Zhang; Yi xiang Ye; Qi feng Wei; Nian gui Zhao; Jian ping Jiang; Xiao ying Ji; Chun xia Zhou; Chao Zheng; Wen Zhang; Li zhong Xie; Yong chao Hu; Jian quan He; Jian Chen; Wang yue Wang; Chang hua Zhang; Liming Cao; Wen Xu; Yunhong Lei; Zheng hua Jian; Wei ping Hu; Wen juan Qin; Wan yu Wang; Yu long He; Hang Xiao; Xiao fang Zheng; Yi Qun Hu; Wen Sheng Pan; Jian feng Cai

The case series with COVID-19 were from the Affiliated Nanping First Hospital of Fujian Medical University (NPFH), located in Nanping, Fujian Province. NPFH was the designated hospital for admission of COVID-19 infection patients in Nanping city, and set up the expert group for medical treatment of COVID-19 (Conv-MG). Suspicious patients found by other medical units in Nanping city after preliminary screening should be transferred to NPFH for treatment. All patients with NCIP enrolled in this study were diagnosed according to World Health Organization interim guidance. From January 29 th to February 14 th , the ConV-TG of NPFH used electronic stethoscopes to auscultate the lungs of newly admitted patients with COVID-19 infection. On March 5, after all the patients were discharged from the hospital, the clinical data and laboratory examination results of the above patients were retrospectively analyzed, which included the pulmonary signs. The study was approved by the ethics committee of NPFH (202002050). Oral permission was obtained from patients before lung auscultation. All patients were informed prior to physical examination. With the patient's oral consent, we gave them lung auscultation. Electronic stethoscope, auscultation and recording method The stethoscope utilizes Doctorgram stethoscope DES-I (GV concepts, USA), which is a Hand-held portable Bluetooth electronic stethoscope. The stethoscope head is membrane-shaped and bellshaped, and the frequency range of receiving signals is 20Hz-2KHz, which is amplified for 24 times. There is no separate filtering of cardiac and respiratory sounds. The signal is transmitted to the software terminal of the mobile phone or computer in real time through Bluetooth. The number of terminals is unlimited, and multiple doctors can be connected at the same time. The sound can be stored by the lossless compression technology of FLAC, which can continue record for 30 s. In this study, respiratory sound data were acquired on the day of patients were admitted to the NPFH. All records were obtained with the subjects in a seated position. The order of auscultation starts from the tip of the lung, from top to bottom. The anterior chest, lateral chest and back are symmetrically examined from left to right. Tracheal breath sounds, bronchial breath sounds, bronchoalveolar breath sounds and alveolar breath sounds were examined and collected respectively ( Figure S1 .). Lastly, speech resonance is detected and left-to-right contrast is made. All breath sounds of each patient were collected by the same physician in the isolation ward, to ensure the stability of audios collected from different patients. The Conv-MG conducted multidisciplinary treatment (MDT) by video equipment outside of the isolation ward. The exported audio is preliminarily reviewed and checked by the doctor who collected the breath sounds. To conduct auscultation inspection on the recording quality, sort and label the audio by the corresponding auscultation position as well as the type of breath sound. Another data analyst used audio editing software (Cool Edit Pro v. 2.0; Syntrillium Software Corporation, USA) to initially edit the audio according to the previous label, and remove the audio with low quality. Exclusion criteria include: audio with high background noise, short recording time (at least 2 complete breathing sounds), and low breathing sound signal due to poor contacts or conduction.