deep learning models

  • 文章类型: Journal Article
    背景:日常生活活动(ADL)对于独立和个人福祉至关重要,反映个人的功能状态。执行这些任务的障碍会限制自主性并对生活质量产生负面影响。ADL期间的身体功能评估对于运动限制的预防和康复至关重要。尽管如此,其传统的基于主观观察的评价在精确性和客观性方面存在局限性。
    目的:本研究的主要目的是使用创新技术,特别是可穿戴惯性传感器结合人工智能技术,客观准确地评估人类在ADL中的表现。提出了通过实现允许在日常活动期间对运动进行动态和非侵入性监测的系统来克服传统方法的局限性。该方法旨在为早期发现功能障碍和个性化治疗和康复计划提供有效的工具,从而促进个人生活质量的提高。
    方法:要监视运动,开发了可穿戴惯性传感器,其中包括加速度计和三轴陀螺仪。开发的传感器用于创建专有数据库,其中6个动作与肩膀有关,3个动作与背部有关。我们在数据库中注册了53,165个活动记录(包括加速度计和陀螺仪测量),在处理以删除null或异常值后,将其减少到52,600。最后,通过组合各种处理层创建了4个深度学习(DL)模型,以探索ADL识别中的不同方法。
    结果:结果显示了4种提出的模型的高性能,有了准确的水平,精度,召回,所有类别的F1得分在95%至97%之间,平均损失0.10。这些结果表明,模型能够准确识别各种活动,在准确率和召回率之间取得了很好的平衡。卷积和双向方法都取得了稍微优越的结果,尽管双向模型在较少的时间内达到了收敛。
    结论:实现的DL模型表现出了良好的性能,表明识别和分类与肩部和腰部区域相关的各种日常活动的有效能力。这些结果是通过最小的传感器实现的-是非侵入性的,并且实际上对用户来说是不可察觉的-这不会影响他们的日常工作,并促进对连续监测的接受和坚持。从而提高了收集数据的可靠性。这项研究可能对运动受限患者的临床评估和康复产生重大影响,通过提供客观和先进的工具来检测关键的运动模式和关节功能障碍。
    BACKGROUND: Activities of daily living (ADL) are essential for independence and personal well-being, reflecting an individual\'s functional status. Impairment in executing these tasks can limit autonomy and negatively affect quality of life. The assessment of physical function during ADL is crucial for the prevention and rehabilitation of movement limitations. Still, its traditional evaluation based on subjective observation has limitations in precision and objectivity.
    OBJECTIVE: The primary objective of this study is to use innovative technology, specifically wearable inertial sensors combined with artificial intelligence techniques, to objectively and accurately evaluate human performance in ADL. It is proposed to overcome the limitations of traditional methods by implementing systems that allow dynamic and noninvasive monitoring of movements during daily activities. The approach seeks to provide an effective tool for the early detection of dysfunctions and the personalization of treatment and rehabilitation plans, thus promoting an improvement in the quality of life of individuals.
    METHODS: To monitor movements, wearable inertial sensors were developed, which include accelerometers and triaxial gyroscopes. The developed sensors were used to create a proprietary database with 6 movements related to the shoulder and 3 related to the back. We registered 53,165 activity records in the database (consisting of accelerometer and gyroscope measurements), which were reduced to 52,600 after processing to remove null or abnormal values. Finally, 4 deep learning (DL) models were created by combining various processing layers to explore different approaches in ADL recognition.
    RESULTS: The results revealed high performance of the 4 proposed models, with levels of accuracy, precision, recall, and F1-score ranging between 95% and 97% for all classes and an average loss of 0.10. These results indicate the great capacity of the models to accurately identify a variety of activities, with a good balance between precision and recall. Both the convolutional and bidirectional approaches achieved slightly superior results, although the bidirectional model reached convergence in a smaller number of epochs.
    CONCLUSIONS: The DL models implemented have demonstrated solid performance, indicating an effective ability to identify and classify various daily activities related to the shoulder and lumbar region. These results were achieved with minimal sensorization-being noninvasive and practically imperceptible to the user-which does not affect their daily routine and promotes acceptance and adherence to continuous monitoring, thus improving the reliability of the data collected. This research has the potential to have a significant impact on the clinical evaluation and rehabilitation of patients with movement limitations, by providing an objective and advanced tool to detect key movement patterns and joint dysfunctions.
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  • 文章类型: Journal Article
    由于在不同的成像方式下癌性病变的复杂结构,使用计算机辅助诊断(CAD)系统对医学图像进行解释是艰巨的,班级之间高度相似,类内存在不同的特征,医疗数据的稀缺性,以及工件和噪音的存在。在这项研究中,这些挑战通过开发具有最佳配置的浅层卷积神经网络(CNN)模型来解决,该模型通过改变层结构和超参数并利用合适的增强技术来执行消融研究。研究了八个具有不同模态的医疗数据集,其中所提出的模型,名为MNet-10,具有低计算复杂度,能够在所有数据集上产生最佳性能。还评估了光度和几何增强技术对不同数据集的影响。我们选择乳房X线照片数据集作为最具挑战性的成像方式之一进行消融研究。在生成模型之前,使用这两种方法来增强数据集。首先构建基本CNN模型,并将其应用于增强和非增强乳房X线照片数据集,其中利用光度数据集获得最高精度。因此,通过使用乳房X线照片光度数据集对基础模型进行消融研究来确定模型的架构和超参数。之后,网络的健壮性和不同增强技术的影响是通过用其余的七个数据集训练模型来评估的。我们在乳房X线照片上获得了97.34%的测试准确率,98.43%的人患皮肤癌,99.54%的脑肿瘤磁共振成像(MRI),97.29%的COVID胸部X光检查,96.31%在鼓膜上,胸部计算机断层扫描(CT)扫描占99.82%,和98.75%的乳腺癌超声数据集通过光度增强和96.76%的乳腺癌显微活检数据集通过几何增强。此外,使用所提出的模型,使用所有数据集来探索一些弹性变形增强方法,以评估其有效性。最后,VGG16、InceptionV3和ResNet50在性能最佳的增强数据集上进行了训练,并将它们的性能一致性与MNet-10模型进行了比较。这些发现可能会帮助未来的研究人员进行涉及消融研究和增强技术的医疗数据分析。
    Interpretation of medical images with a computer-aided diagnosis (CAD) system is arduous because of the complex structure of cancerous lesions in different imaging modalities, high degree of resemblance between inter-classes, presence of dissimilar characteristics in intra-classes, scarcity of medical data, and presence of artifacts and noises. In this study, these challenges are addressed by developing a shallow convolutional neural network (CNN) model with optimal configuration performing ablation study by altering layer structure and hyper-parameters and utilizing a suitable augmentation technique. Eight medical datasets with different modalities are investigated where the proposed model, named MNet-10, with low computational complexity is able to yield optimal performance across all datasets. The impact of photometric and geometric augmentation techniques on different datasets is also evaluated. We selected the mammogram dataset to proceed with the ablation study for being one of the most challenging imaging modalities. Before generating the model, the dataset is augmented using the two approaches. A base CNN model is constructed first and applied to both the augmented and non-augmented mammogram datasets where the highest accuracy is obtained with the photometric dataset. Therefore, the architecture and hyper-parameters of the model are determined by performing an ablation study on the base model using the mammogram photometric dataset. Afterward, the robustness of the network and the impact of different augmentation techniques are assessed by training the model with the rest of the seven datasets. We obtain a test accuracy of 97.34% on the mammogram, 98.43% on the skin cancer, 99.54% on the brain tumor magnetic resonance imaging (MRI), 97.29% on the COVID chest X-ray, 96.31% on the tympanic membrane, 99.82% on the chest computed tomography (CT) scan, and 98.75% on the breast cancer ultrasound datasets by photometric augmentation and 96.76% on the breast cancer microscopic biopsy dataset by geometric augmentation. Moreover, some elastic deformation augmentation methods are explored with the proposed model using all the datasets to evaluate their effectiveness. Finally, VGG16, InceptionV3, and ResNet50 were trained on the best-performing augmented datasets, and their performance consistency was compared with that of the MNet-10 model. The findings may aid future researchers in medical data analysis involving ablation studies and augmentation techniques.
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  • 文章类型: Journal Article
    深度学习模型是用于数据分析的工具,适用于近似变量之间的(非线性)关系,以便对结果进行最佳预测。虽然这些模型可以用来回答许多重要的问题,他们的效用仍然受到严厉批评,识别哪些数据描述符最适合表示给定的特定感兴趣现象是极具挑战性的。根据最近开发用于检测机械水表设备故障的深度学习模型的经验,我们已经了解到,如果一个人试图通过添加特定的设备描述符来训练深度学习模型,那么预测准确性可能会出现明显的下降。基于分类数据。这可能是因为数据维度的过度增加,具有相应的统计显著性损失。在使用替代方法进行了几次失败的实验之后,这些方法要么允许减少数据空间维度,要么采用更传统的机器学习算法。我们改变了训练策略,重新考虑分类数据,根据帕累托分析。实质上,我们使用了这些分类描述符,不是作为训练我们的深度学习模型的输入,但是作为一种为数据集提供新形状的工具,基于帕累托规则。有了这个数据调整,我们训练了一个性能更高的深度学习模型,能够检测有缺陷的水表设备,预测精度在87-90%之间,即使存在分类描述符。
    Deep learning models are tools for data analysis suitable for approximating (non-linear) relationships among variables for the best prediction of an outcome. While these models can be used to answer many important questions, their utility is still harshly criticized, being extremely challenging to identify which data descriptors are the most adequate to represent a given specific phenomenon of interest. With a recent experience in the development of a deep learning model designed to detect failures in mechanical water meter devices, we have learnt that a sensible deterioration of the prediction accuracy can occur if one tries to train a deep learning model by adding specific device descriptors, based on categorical data. This can happen because of an excessive increase in the dimensions of the data, with a correspondent loss of statistical significance. After several unsuccessful experiments conducted with alternative methodologies that either permit to reduce the data space dimensionality or employ more traditional machine learning algorithms, we changed the training strategy, reconsidering that categorical data, in the light of a Pareto analysis. In essence, we used those categorical descriptors, not as an input on which to train our deep learning model, but as a tool to give a new shape to the dataset, based on the Pareto rule. With this data adjustment, we trained a more performative deep learning model able to detect defective water meter devices with a prediction accuracy in the range 87-90%, even in the presence of categorical descriptors.
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