A Mobile Cough Strength Evaluation Device Using Cough Sounds.

Yasutaka Umayahara,Akira Otsuka,Toshio Tsuji,Kiyokazu Sekikawa,Toshihiro Kawae,Zu Soh

doi:10.3390/s18113810

Abstract

Although cough peak flow (CPF) is an important measurement for evaluating the risk of cough dysfunction, some patients cannot use conventional measurement instruments, such as spirometers, because of the configurational burden of the instruments. Therefore, we previously developed a cough strength estimation method using cough sounds based on a simple acoustic and aerodynamic model. However, the previous model did not consider age or have a user interface for practical application. This study clarifies the cough strength prediction accuracy using an improved model in young and elderly participants. Additionally, a user interface for mobile devices was developed to record cough sounds and estimate cough strength using the proposed method. We then performed experiments on 33 young participants (21.3 ± 0.4 years) and 25 elderly participants (80.4 ± 6.1 years) to test the effect of age on the CPF estimation accuracy. The percentage error between the measured and estimated CPFs was approximately 6.19%. In addition, among the elderly participants, the current model improved the estimation accuracy of the previous model by a percentage error of approximately 6.5% (p < 0.001). Furthermore, Bland-Altman analysis demonstrated no systematic error between the measured and estimated CPFs. These results suggest that the developed device can be applied for daily CPF measurements in clinical practice.

Highlights

The cough is an important defence mechanism for clearing excess secretions and foreign materials from airways [1,2]
This paper presents a cough strength evaluation based on cough sounds considering the effect of age and designed for daily use in clinical practice along with a custom-designed user interface
This study found that body weight and body mass index (BMI) have minimal effects on the cough peak flow (CPF) estimation accuracy

Summary

Introduction

The cough is an important defence mechanism for clearing excess secretions and foreign materials from airways [1,2]. Cough peak flows (CPFs) are measured using a spirometer or a peak flow meter to assess cough strength because cough strength reflects the ability to clear secretions from the respiratory tract and indicates the aspiration risk. It is unlikely that someone with a CPF greater than 270 L/min will develop acute respiratory distress [3]. Patients with a CPF greater than 160 L/min can manage ventilatory failure without a tracheostomy [4,5]. Dysphagic patients with persistent tracheobronchial aspiration with a CPF less than 242 L/min have a high risk of developing pulmonary complications [6]. Previous studies have reported the importance of CPF as a measurement for assessing the ability to expel airway secretions, it requires a face mask and a bacterial

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Discussion

Conclusion