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Chronic Obstructive Pulmonary Disease (COPD), as the third leading cause of death worldwide, is a major global health issue. The early detection and grading of COPD are pivotal for effective treatment. Traditional spirometry tests, requiring considerable physical effort and strict adherence to quality standards, pose challenges in COPD diagnosis. Volumetric capnography (VCap), which can be performed during natural breathing without requiring additional compliance, presents a promising alternative tool. In this study, the dataset comprised 279 subjects with normal pulmonary function and 148 patients diagnosed with COPD. We introduced a novel quantitative analysis method for VCap. Volumetric capnograms were converted into two-dimensional grayscale images through the application of Gramian Angular Field (GAF) transformation. Subsequently, a multi-scale convolutional neural network, CapnoNet, was conducted to extract features and facilitate classification. To improve CapnoNet's performance, two data augmentation techniques were implemented. The proposed model exhibited a detection accuracy for COPD of 95.83%, with precision, recall, and F1 measures of 95.21%, 95.70%, and 95.45%, respectively. In the task of grading the severity of COPD, the model attained an accuracy of 96.36%, complemented by precision, recall, and F1 scores of 88.49%, 89.99%, and 89.15%, respectively. This work provides a new perspective for the quantitative analysis of volumetric capnography and demonstrates the strong performance of the proposed CapnoNet in the diagnosis and grading of COPD. It offers direction and an effective solution for the clinical application of capnography. [ABSTRACT FROM AUTHOR]

Dementia‐associated disorders cause damage to the brains of patients and bring huge burdens to individuals and families. Electroencephalogram (EEG) monitoring is friendly to patients on account of low cost, non‐invasion, and objective. Event‐related potential (ERP) is a component of EEG that has huge potential to evaluate the cognitive function of the brain. In this study, we recorded the ERP from patients with dementia and healthy people, then proposed an ERP‐based deep learning method to realize dementia recognition via the model Dementia‐Unet (D‐Unet). To improve the performance of the model, on the base of the decoder and the primary classifier, we added new structures including a symmetric decoder and two auxiliary outputs. One of the auxiliary outputs was input reconstruction, and the other one was aimed at working like the primary classifier with the same task. The results of the experiment of four‐fold cross‐validation demonstrated the two auxiliary outputs improved the performance of the model effectively. When compared with some other machine learning methods and deep learning methods, our model obtained the best performance with an accuracy of 0.815, a precision of 0.829, a recall of 0.797, and an f1‐score of 0.812. Besides, we put up a complex training strategy with all outputs involved, but a simple testing strategy with only a primary classifier working to keep high performance but cut down the complexity burden during testing. [ABSTRACT FROM AUTHOR]

Silent speech recognition (SSR) is a system that can recognize verbal expressions when speech signals are not accessible. It has found versatile applications not only in helping those who suffer a speech impediment, but also in human–computer interaction. In this paper, we propose an SSR system based on surface electromyography (sEMG) signals. We first design a Mandarin corpus which contains 135-class utterances and collect 8-channel sEMG data from 12 subjects. After preprocessing the raw sEMG signals, we extract a time–frequency hybrid feature map for each sample. Then, we use two data augmentation strategies to obtain more data in order to improve the performance of our model. Finally, we test our proposed models on two tasks: the multi-subject mixed classification task and the single subject classification task. We use a 5-fold cross-validation to evaluate our model on both tasks. The GRU model performs best, achieving a recognition accuracy of 88.01% on the multi-subject mixed classification task and a maximum recognition accuracy of 97.19% on the single subject classification task. Experiments results demonstrate the effectiveness of our proposed system. • A silent speech system based on surface electromyography signals and deep learning models. • Time–frequency hybrid features are extracted from surface electromyography signals. • Speed perturbation and time–frequency masking are used for data augmentation. • Several deep learning models are evaluated on two different tasks; The GRU model performed the best. [ABSTRACT FROM AUTHOR]

• The MIF-AFNet can fuse the deep features of RRIs and ECG for AF binary detection. • The data augmentation method of vertical flipping can eliminate the morphological imbalance, thus effectively alleviating overfitting. • The MIF-AFNet is five-fold cross-validated on the CPSC2021 dataset and independently tested on four external databases. • The performance results verify excellent generalization performance for the method. The reliable detection of atrial fibrillation (AF) is important for diagnosing the disease, tracking its progression, and developing individualized care strategies. However, models based on limited data are prone to data dependency due to differences in data feature distribution, which generally degrades their performance on unseen external datasets. In this work, we propose a multi-input fusion AF detection network (MIF-AFNet), which cascades residual convolutional neural networks and bidirectional long short-term memory networks to capture the deep features of electrocardiogram (ECG) and RR intervals (RRIs), respectively. Additionally, the ECG signals use a data augmentation method to alleviate the morphological imbalance. MIF-AFNet learns a robust feature representation for accurate AF detection by fusing the available information from RRIs and ECG. The proposed method was developed and evaluated using 5 long-term ECG datasets (CPSC2021, AFDB, LTAF, MITDB, and NSRDB) from PhysioNet. The subject-wise five-fold cross-validation was performed on CPSC2021, and the proposed method achieved an AF detection accuracy of 98.63%. The generalization performance is further evaluated on four external independent datasets (AFDB, LTAF, MITDB, and NSRDB), achieving accuracies of 98.63%, 97.04%, 98.07%, and 100%, respectively. The results show that the proposed method can accurately detect AF from long-term ECG recordings. In addition, the low complexity of the model makes it less demanding on computing resources. Therefore, it has the potential to improve the automatic diagnosis and management of AF in wearable device-based long-term home monitoring. [ABSTRACT FROM AUTHOR]

In the field of Transfer Learning, Source-Free Unsupervised Domain Adaptation (SFUDA) emerges as a practical and novel task that enables a pre-trained model to adapt to a new unlabeled domain without access to the original training data. The advancement of SFUDA has profoundly reshaped the algorithmic design of domain adaptation methods. Given the novelty and limited exploration of SFUDA, conducting a comprehensive survey is imperative to showcase methodological advancements, identify existing gaps, and uncover potential trends in this field. This paper provides an extensive review of SFUDA, encompassing methods and applications. First, based on the learning objectives during adaptation, different SFUDA methods fall into three categories: (i) Self-Tuning , (ii) Feature Alignment , and (iii) Sample Generation , with further sub-categorization within each category. Additionally, the strengths and limitations of each category are discussed, and various application areas where SFUDA can yield significant benefits are summarized. Finally, drawing from extensive observations and insights, potential future directions for SFUDA research are analyzed, with a focus on identifying emerging trends and key areas for further exploration. • A Comprehensive Review of SFUDA : The paper offers a review of SFUDA, to fill the gaps left by previous studies. • Critical Discussions on SFUDA : Based on the review, critical discussions are highlighted to deepen the understandings. • Future Directions for SFUDA : The paper outlines research directions for SFUDA, providing guidance to future advancements. [ABSTRACT FROM AUTHOR]