IEEE Trans Biomed Circuits Syst. 2020 Jun;14(3):535-544. doi: 10.1109/TBCAS.2020.2981172. Epub 2020 Mar 18.
The primary objective of this paper is to build classification models and strategies to identify breathing sound anomalies (wheeze, crackle) for automated diagnosis of respiratory and pulmonary diseases. In this work we propose a deep CNN-RNN model that classifies respiratory sounds based on Mel-spectrograms. We also implement a patient specific model tuning strategy that first screens respiratory patients and then builds patient specific classification models using limited patient data for reliable anomaly detection. Moreover, we devise a local log quantization strategy for model weights to reduce the memory footprint for deployment in memory constrained systems such as wearable devices. The proposed hybrid CNN-RNN model achieves a score of [Formula: see text] on four-class classification of breathing cycles for ICBHI'17 scientific challenge respiratory sound database. When the model is re-trained with patient specific data, it produces a score of [Formula: see text] for leave-one-out validation. The proposed weight quantization technique achieves ≈ 4 × reduction in total memory cost without loss of performance. The main contribution of the paper is as follows: Firstly, the proposed model is able to achieve state of the art score on the ICBHI'17 dataset. Secondly, deep learning models are shown to successfully learn domain specific knowledge when pre-trained with breathing data and produce significantly superior performance compared to generalized models. Finally, local log quantization of trained weights is shown to be able to reduce the memory requirement significantly. This type of patient-specific re-training strategy can be very useful in developing reliable long-term automated patient monitoring systems particularly in wearable healthcare solutions.
本文的主要目的是构建分类模型和策略,以识别呼吸音异常(喘息、爆裂声),从而实现呼吸和肺部疾病的自动诊断。在这项工作中,我们提出了一种基于梅尔频谱图对呼吸音进行分类的深度 CNN-RNN 模型。我们还实现了一种针对特定患者的模型调整策略,该策略首先筛选呼吸患者,然后使用有限的患者数据为可靠的异常检测构建针对特定患者的分类模型。此外,我们设计了一种局部对数量化策略来对模型权重进行量化,以减少在内存受限系统(如可穿戴设备)中部署的内存占用。所提出的混合 CNN-RNN 模型在 ICBHI'17 科学挑战呼吸声音数据库的四类呼吸周期分类中获得了[Formula: see text]的分数。当使用特定于患者的数据重新训练模型时,它在留一法验证中产生了[Formula: see text]的分数。所提出的权重量化技术在不损失性能的情况下,总内存成本减少了约 4 倍。本文的主要贡献如下:首先,所提出的模型能够在 ICBHI'17 数据集上达到最新的得分。其次,当使用呼吸数据进行预训练时,深度学习模型能够成功地学习到特定领域的知识,并产生比通用模型显著更好的性能。最后,训练后的权重的局部对数量化被证明能够显著减少内存需求。这种针对特定患者的重新训练策略在开发可靠的长期自动患者监测系统,特别是在可穿戴医疗保健解决方案中,可能非常有用。