Intensive Care in-hospital mortality prediction has various clinical applications. Neural prediction models, especially when capitalising on clinical notes, have been put forward as improvement on currently existing models. However, to be acceptable these models should be performant and transparent. This work studies different attention mechanisms for clinical neural prediction models in terms of their discrimination and calibration. Specifically, we investigate sparse attention as an alternative to dense attention weights in the task of in-hospital mortality prediction from clinical notes. We evaluate the attention mechanisms based on: i) local self-attention over words in a sentence, and ii) global self-attention with a transformer architecture across sentences. We demonstrate that the sparse mechanism approach outperforms the dense one for the local self-attention in terms of predictive performance with a publicly available dataset, and puts higher attention to prespecified relevant directive words. The performance at the sentence level, however, deteriorates as sentences including the influential directive words tend to be dropped all together.
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Neural models, with their ability to provide novel representations, have shown promising results in prediction tasks in healthcare. However, patient demographics, medical technology, and quality of care change over time. This often leads to drop in the performance of neural models for prospective patients, especially in terms of their calibration. The deep kernel learning (DKL) framework may be robust to such changes as it combines neural models with Gaussian processes, which are aware of prediction uncertainty. Our hypothesis is that out-of-distribution test points will result in probabilities closer to the global mean and hence prevent overconfident predictions. This in turn, we hypothesise, will result in better calibration on prospective data. This paper investigates DKL's behaviour when facing a temporal shift, which was naturally introduced when an information system that feeds a cohort database was changed. We compare DKL's performance to that of a neural baseline based on recurrent neural networks. We show that DKL indeed produced superior calibrated predictions. We also confirm that the DKL's predictions were indeed less sharp. In addition, DKL's discrimination ability was even improved: its AUC was 0.746 (+- 0.014 std), compared to 0.739 (+- 0.028 std) for the baseline. The paper demonstrated the importance of including uncertainty in neural computing, especially for their prospective use.
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我们提出了一种三级等级变压器网络(3级),用于在临床笔记上建模长期依赖性,以患者级预测的目的。该网络配备了三个级别的基于变压器的编码器,以逐步地从单词中学到句子,句子票据,最后给患者注释。单词到句子的第一级直接将预先训练的BERT模型应用为完全可训练的组件。虽然第二和第三级实现了一堆基于变压器的编码器,但在最终患者表示进入临床预测的分类层之前。与传统的BERT模型相比,我们的模型将512个令牌的最大输入长度增加到适合建模大量临床笔记的更长的序列。我们经验检查不同的超参数,以识别给定的计算资源限制的最佳权衡。我们的实验结果对不同预测任务的模拟-III数据集表明,所提出的等级变压器网络优于以前的最先进的模型,包括但不限于BigBird。
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尽管变压器语言模型(LMS)是信息提取的最新技术,但长文本引入了需要次优的预处理步骤或替代模型体系结构的计算挑战。稀疏注意的LMS可以代表更长的序列,克服性能障碍。但是,目前尚不清楚如何解释这些模型的预测,因为并非所有令牌都在自我发项层中相互参加,而在运行时,长序列对可解释性算法提出了计算挑战,而当运行时取决于文档长度。这些挑战在文档可能很长的医学环境中是严重的,机器学习(ML)模型必须是审核和值得信赖的。我们介绍了一种新颖的蒙版抽样程序(MSP),以识别有助于预测的文本块,将MSP应用于预测医学文本诊断的背景下,并通过两位临床医生的盲目审查来验证我们的方法。我们的方法比以前的最先进的临床信息块高约1.7倍,速度更快100倍,并且可用于生成重要的短语对。 MSP特别适合长LMS,但可以应用于任何文本分类器。我们提供了MSP的一般实施。
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Transformer models have achieved great success across many NLP problems. However, previous studies in automated ICD coding concluded that these models fail to outperform some of the earlier solutions such as CNN-based models. In this paper we challenge this conclusion. We present a simple and scalable method to process long text with the existing transformer models such as BERT. We show that this method significantly improves the previous results reported for transformer models in ICD coding, and is able to outperform one of the prominent CNN-based methods.
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Future surveys such as the Legacy Survey of Space and Time (LSST) of the Vera C. Rubin Observatory will observe an order of magnitude more astrophysical transient events than any previous survey before. With this deluge of photometric data, it will be impossible for all such events to be classified by humans alone. Recent efforts have sought to leverage machine learning methods to tackle the challenge of astronomical transient classification, with ever improving success. Transformers are a recently developed deep learning architecture, first proposed for natural language processing, that have shown a great deal of recent success. In this work we develop a new transformer architecture, which uses multi-head self attention at its core, for general multi-variate time-series data. Furthermore, the proposed time-series transformer architecture supports the inclusion of an arbitrary number of additional features, while also offering interpretability. We apply the time-series transformer to the task of photometric classification, minimising the reliance of expert domain knowledge for feature selection, while achieving results comparable to state-of-the-art photometric classification methods. We achieve a logarithmic-loss of 0.507 on imbalanced data in a representative setting using data from the Photometric LSST Astronomical Time-Series Classification Challenge (PLAsTiCC). Moreover, we achieve a micro-averaged receiver operating characteristic area under curve of 0.98 and micro-averaged precision-recall area under curve of 0.87.
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自动化医疗编码,医疗保健操作和交付的基本任务,通过从临床文献预测医学代码来实现非结构化数据。自然语言处理中深入学习模型的最新进展已被广泛应用于此任务。然而,它缺乏对医学编码的神经网络架构设计的统一视图。本综述提出了一个统一的框架,为医疗编码模型的构建块提供了一般性的理解,并概述了近期框架下的最新模型。我们的统一框架将医疗编码分解为四个主要组件,即文本特征提取的编码器模块,为构建深编码器架构的机制,解码器模块,用于将隐藏的表示转换为医学代码,以及辅助信息的使用。最后,我们讨论了关键的研究挑战和未来方向。
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基于变压器模型架构的最近深入学习研究在各种域和任务中展示了最先进的性能,主要是在计算机视觉和自然语言处理域中。虽然最近的一些研究已经实施了使用电子健康记录数据的临床任务的变压器,但它们的范围,灵活性和全面性有限。在本研究中,我们提出了一种灵活的基于变换器的EHR嵌入管道和预测模型框架,它引入了利用了医疗域唯一的数据属性的现有工作流程的几个新颖修改。我们展示了灵活设计的可行性,在重症监护病房的案例研究中,我们的模型准确地预测了七种临床结果,这些临床结果与多个未来的时间范围有关的入院和患者死亡率。
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基于电子健康记录(EHR)的健康预测建筑模型已成为一个活跃的研究领域。 EHR患者旅程数据由患者定期的临床事件/患者访问组成。大多数现有研究的重点是建模访问之间的长期依赖性,而无需明确考虑连续访问之间的短期相关性,在这种情况下,将不规则的时间间隔(并入为辅助信息)被送入健康预测模型中以捕获患者期间的潜在渐进模式。 。我们提出了一个具有四个模块的新型深神经网络,以考虑各种变量对健康预测的贡献:i)堆叠的注意力模块在每个患者旅程中加强了临床事件中的深层语义,并产生访问嵌入,ii)短 - 术语时间关注模块模型在连续访问嵌入之间的短期相关性,同时捕获这些访问嵌入中时间间隔的影响,iii)长期时间关注模块模型的长期依赖模型,同时捕获时间间隔内的时间间隔的影响这些访问嵌入,iv),最后,耦合的注意模块适应了短期时间关注和长期时间注意模块的输出,以做出健康预测。对模拟III的实验结果表明,与现有的最新方法相比,我们的模型的预测准确性以及该方法的可解释性和鲁棒性。此外,我们发现建模短期相关性有助于局部先验的产生,从而改善了患者旅行的预测性建模。
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根据诊断各种疾病的胸部X射线图像的可观增长,以及收集广泛的数据集,使用深神经网络进行了自动诊断程序,已经占据了专家的思想。计算机视觉中的大多数可用方法都使用CNN主链来获得分类问题的高精度。然而,最近的研究表明,在NLP中成为事实上方法的变压器也可以优于许多基于CNN的模型。本文提出了一个基于SWIN变压器的多标签分类深模型,作为实现最新诊断分类的骨干。它利用了头部体系结构来利用多层感知器(也称为MLP)。我们评估了我们的模型,该模型称为“ Chest X-Ray14”,最广泛,最大的X射线数据集之一,该数据集由30,000多名14例著名胸部疾病的患者组成100,000多个额叶/背景图像。我们的模型已经用几个数量的MLP层用于头部设置,每个模型都在所有类别上都达到了竞争性的AUC分数。胸部X射线14的全面实验表明,与以前的SOTA平均AUC为0.799相比,三层头的平均AUC得分为0.810,其平均AUC得分为0.810。我们建议对现有方法进行公平基准测试的实验设置,该设置可以用作未来研究的基础。最后,我们通过确认所提出的方法参与胸部的病理相关区域,从而跟进了结果。
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变形金机对文本建模很重要。但是,由于输入文本长度的二次复杂性,它难以处理长文件。为了处理这个问题,我们提出了一种分层交互式变压器(高变压器),用于高效且有效的长文档建模。高变压器模型以分层方式模型,即首先了解句子表示,然后学习文档表示。它可以有效地降低复杂性,同时在每个句子的建模中捕获全局文档上下文。更具体地说,我们首先使用句子变压器来学习每个句子的表示。然后我们使用文档变形器从这些句子表示中模拟全局文档上下文。接下来,我们使用另一个句子变换器来使用全局文档上下文增强句子建模。最后,我们使用分层汇集方法获取文档嵌入。三个基准数据集的广泛实验验证了长文档建模中高变压器的效率和效力。
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With the development of natural language processing techniques(NLP), automatic diagnosis of eye diseases using ophthalmology electronic medical records (OEMR) has become possible. It aims to evaluate the condition of both eyes of a patient respectively, and we formulate it as a particular multi-label classification task in this paper. Although there are a few related studies in other diseases, automatic diagnosis of eye diseases exhibits unique characteristics. First, descriptions of both eyes are mixed up in OEMR documents, with both free text and templated asymptomatic descriptions, resulting in sparsity and clutter of information. Second, OEMR documents contain multiple parts of descriptions and have long document lengths. Third, it is critical to provide explainability to the disease diagnosis model. To overcome those challenges, we present an effective automatic eye disease diagnosis framework, NEEDED. In this framework, a preprocessing module is integrated to improve the density and quality of information. Then, we design a hierarchical transformer structure for learning the contextualized representations of each sentence in the OEMR document. For the diagnosis part, we propose an attention-based predictor that enables traceable diagnosis by obtaining disease-specific information. Experiments on the real dataset and comparison with several baseline models show the advantage and explainability of our framework.
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目的:临床票据含有其他地方未存在的信息,包括药物反应和症状,所有这些都在预测急性护理患者的关键结果时非常重要。我们提出了从临床笔记中的表型作为一种捕获基本信息的方法的自动注释,这与通常使用生命体征和实验室测试结果的互补性,以预测重症监护单元(ICU)中的结果。方法:我们开发一种新颖的表型注释模型,用于注释患者的表型特征,然后用作预测模型的输入特征,以预测ICU患者结果。我们展示并验证了我们的方法对三个ICU预测任务进行实验,包括使用MIMIC-III数据集的医院死亡率,生理失效和超过24,000名患者的逗留时间。结果:掺入表型信息的预测模型实现0.845(AUC-ROC),以预测医院死亡率,0.839(AUC-ROC)的生理失代偿和0.430(Kappa),所有这些都始终胜过基线模型利用只有生命的迹象和实验室测试结果。此外,我们进行了彻底的解释性研究,表明表型在患者和队列水平方面提供了有价值的见解。结论:该方法表明表型信息是传统上使用生命体征和实验室测试结果的补充,改善了ICU中的结果的重要预测。
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The dominant sequence transduction models are based on complex recurrent or convolutional neural networks that include an encoder and a decoder. The best performing models also connect the encoder and decoder through an attention mechanism. We propose a new simple network architecture, the Transformer, based solely on attention mechanisms, dispensing with recurrence and convolutions entirely. Experiments on two machine translation tasks show these models to be superior in quality while being more parallelizable and requiring significantly less time to train. Our model achieves 28.4 BLEU on the WMT 2014 Englishto-German translation task, improving over the existing best results, including ensembles, by over 2 BLEU. On the WMT 2014 English-to-French translation task, our model establishes a new single-model state-of-the-art BLEU score of 41.0 after training for 3.5 days on eight GPUs, a small fraction of the training costs of the best models from the literature. * Equal contribution. Listing order is random. Jakob proposed replacing RNNs with self-attention and started the effort to evaluate this idea. Ashish, with Illia, designed and implemented the first Transformer models and has been crucially involved in every aspect of this work. Noam proposed scaled dot-product attention, multi-head attention and the parameter-free position representation and became the other person involved in nearly every detail. Niki designed, implemented, tuned and evaluated countless model variants in our original codebase and tensor2tensor. Llion also experimented with novel model variants, was responsible for our initial codebase, and efficient inference and visualizations. Lukasz and Aidan spent countless long days designing various parts of and implementing tensor2tensor, replacing our earlier codebase, greatly improving results and massively accelerating our research.† Work performed while at Google Brain.‡ Work performed while at Google Research.
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本文介绍了关于剧透筛选的研究。在这种用例中,我们描述了微调和组织基于文本的模型任务的方法,并具有最新的深度学习成果和技术来解释模型的结果。到目前为止,文献中的剧透研究很少描述。我们在带有带注释的扰流板(ROC AUC以上的TV Tropes Point DataSet上超过81 \%的Roc Auc以上的Roc Auc上超过81 \%)的转移学习方法和不同的最新变压器架构。我们还收集了数据并使用细粒度注释组装了新数据集。为此,我们采用了可解释技术和措施来评估模型的可靠性并解释其结果。
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医疗保健自动化的机会可以改善临床医生的吞吐量。一个这样的例子是辅助工具记录诊断代码时,当临床医生写笔记时。我们使用课程学习研究了医学法规预测的自动化,这是机器学习模型的培训策略,可逐渐将学习任务的硬度从易于到困难提高。课程学习的挑战之一是课程的设计 - 即,在逐渐增加难度的任务设计中。我们提出了分层课程学习(HICU),这是一种在输出空间中使用图形结构的算法,以设计用于多标签分类的课程。我们为多标签分类模型创建课程,以预测患者自然语言描述的ICD诊断和程序代码。通过利用ICD代码的层次结构,该层次基于人体的各种器官系统进行诊断代码,我们发现我们的建议课程改善了基于反复,卷积和基于变压器的体系结构的基于神经网络的预测模型的概括。我们的代码可在https://github.com/wren93/hicu-icd上找到。
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We propose a hierarchical attention network for document classification. Our model has two distinctive characteristics: (i) it has a hierarchical structure that mirrors the hierarchical structure of documents; (ii) it has two levels of attention mechanisms applied at the wordand sentence-level, enabling it to attend differentially to more and less important content when constructing the document representation. Experiments conducted on six large scale text classification tasks demonstrate that the proposed architecture outperform previous methods by a substantial margin. Visualization of the attention layers illustrates that the model selects qualitatively informative words and sentences.
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我们利用深度顺序模型来解决预测患者医疗保健利用的问题,这可能有助于政府更好地为未来的医疗保健使用提供资源。具体地,我们研究\纺织{发散亚组}的问题,其中较小的人口小组中的结果分布大大偏离了一般人群的群体。如果亚组的尺寸非常小(例如,稀有疾病),则对不同亚组的专业模型建造专门模型的传统方法可能是有问题的。为了解决这一挑战,我们首先开发一种新的无关注顺序模型,SANSFORMERS,灌输了适合在电子医疗记录中建模临床码的归纳偏差。然后,我们通过在整个健康登记处预先培训每个模型(接近100万名患者)之前,设计了一个特定的自我监督目标,并展示其有效性,特别是稀缺数据设置,特别是在整个健康登记处(接近一百万名患者)进行微调下游任务不同的子组。我们使用两个数据来源与LSTM和变压器模型进行比较新的SANSFARER架构和辅助医疗利用预测的多任务学习目标。凭经验,无关注的Sansformer模型在实验中始终如一地执行,在大多数情况下以至少$ \ SIM 10 $ \%表现出在大多数情况下的基线。此外,在预测医院访问数量时,自我监督的预训练将在整个始终提高性能,例如通过超过$ \ sim 50 $ \%(和高度为800美元\%)。
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电子邮件是通信最广泛的方法之一,数以百万计的人和企业每天依靠它来交流和分享知识和信息。然而,近年来,电子邮件用户的增长量增加了垃圾邮件的急剧增加。适当地为个人和公司进行处理和管理电子邮件变得越来越困难。本文提出了一种用于电子邮件垃圾邮件检测的新技术,该技术基于卷积神经网络,封闭式复发单元和注意机制的组合。在系统培训期间,网络选择性地关注电子邮件文本的必要部分。卷积层的用法是通过层次表示提取更有意义,抽象和可推广的特征,这是本研究的主要贡献。此外,此贡献还包括交叉数据集评估,从而使模型培训数据集产生了更多独立的绩效。根据跨数据库评估结果,该提出的技术通过使用时间卷积来推动基于注意力的技术的结果,这使我们使用了更灵活的接收场大小。将建议的技术的发现与最先进的模型的发现进行了比较,并表明我们的方法表现优于它们。
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临床人工智能(AI)的神经网络的发展依赖于可解释性,透明度和性能。需要深入到黑匣子神经网络中,派生模型输出的解释解释是至关重要的。高临床重要性的任务是在不久的将来预测患者在不久的将户中预留到医院的可能性,以实现有效的分类。随着电子健康记录(EHRS)采用的日益增加,对自然语言处理(NLP)的应用很有兴趣在EHRS中包含的临床自由文本。在这项工作中,我们申请Infocal,目前的最先进的模型,为其预测产生提取理性,以使用医院排放笔记预测医院入院的任务。我们比较Infocal生产的提取理由在临床文本数据上预先追溯的基于竞争变压器的模型,并可用于解释来解释。我们发现每个呈现的模型具有选定的可解释性或特征重要性方法会产生不同的结果,临床语言域专业知识和预测对性能和随后的可解释性至关重要。
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