Nemati Ebrahim, Rahman Md Juber, Blackstock Erin, Nathan Viswam, Rahman Md Mahbubur, Vatanparvar Korosh, Kuang Jilong
Annu Int Conf IEEE Eng Med Biol Soc. 2020 Jul;2020:4491-4497. doi: 10.1109/EMBC44109.2020.9175986.
Spirometry test, a measure of the patient's lung function, is the gold standard for diagnosis and monitoring of chronic pulmonary diseases. Spirometry is currently being done in hospital settings by having the patients blow the air out of their lungs forcefully and into the spirometer's tubes under the supervision and constant guidance of clinicians. This test is expensive, cumbersome and not easily applicable to every-day monitoring of these patients. The lung mechanism when performing a cough is very similar to when spirometry test is done. That includes a big inhalation, air compression and forceful exhalation. Therefore, it is reasonable to assume that obstruction of lung airways should have a similar effect on both cough features and spirometry measures. This paper explores the estimation of lung obstruction using cough acoustic features. A total number of 3695 coughs were collected from patients from 4 different conditions and 4 different severity categories along with their lung function measures in a clinical setting using a smartphone's microphone and a hospital-grade spirometry lab. After feature-set optimization and model hyperparameter tuning, the lung obstruction was estimated with MAE (Mean Absolute Error) of 8% for COPD and 9% for asthma populations. In addition to lung obstruction estimation, we were able to classify patients' disease state with 91% accuracy and patients' severity within each disease state with 95% accuracy.Clinical Relevance- This enables effort-independent estimation of lung function spirometry parameters which could potentially lead to passive monitoring of pulmonary patients.
肺活量测定法是衡量患者肺功能的一种方法，是诊断和监测慢性肺部疾病的金标准。目前，肺活量测定法是在医院环境中，让患者在临床医生的监督和持续指导下，用力将肺部的空气吹入肺活量计的管道中进行的。这项测试成本高昂、操作繁琐，且不易应用于这些患者的日常监测。咳嗽时的肺部机制与进行肺活量测定测试时非常相似。这包括一次深吸气、空气压缩和用力呼气。因此，可以合理地假设，肺气道阻塞对咳嗽特征和肺活量测定指标应该有类似的影响。本文探讨了利用咳嗽声学特征来估计肺部阻塞情况。在临床环境中，使用智能手机麦克风和医院级肺活量测定实验室，从4种不同病情和4种不同严重程度类别的患者那里收集了总共3695次咳嗽以及他们的肺功能测量数据。经过特征集优化和模型超参数调整后，对慢性阻塞性肺疾病（COPD）患者的肺部阻塞估计平均绝对误差（MAE）为8%，对哮喘患者群体为9%。除了肺部阻塞估计外，我们还能够以91%的准确率对患者的疾病状态进行分类，并以95%的准确率对每个疾病状态下患者的严重程度进行分类。临床意义——这使得能够独立于用力程度来估计肺活量测定法的肺功能参数，这可能会带来对肺部疾病患者的被动监测。
