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arXiv 2102.08513cs.CL
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一种上下文增强的去识别系统

A Context-Enhanced De-identification System

George Mason University(乔治梅森大学);U.S. National Library of Medicine(美国国家医学图书馆)

Kahyun Lee, Mehmet Kayaalp, Sam Henry, Özlem Uzuner

摘要:

许多现代实体识别系统,包括当前最先进的去识别系统,都是基于由条件随机场(CRF)序列优化器增强的双向长短期记忆(biLSTM)单元。这些系统逐句处理输入。这种方法可以防止系统捕获句子边界的依赖关系,并使准确的句子边界检测成为先决条件。由于句子边界检测可能是有问题的,特别是在临床报告中,其中跨句子边界的依赖性和共引用是丰富的,这些系统具有明显的局限性。在这项研究中,我们在当前最先进的去识别系统之一NeuroNER的框架上构建了一个新系统,以克服这些限制。这个新系统通过向前和向后的n-gram结合了上下文嵌入,而不使用句子边界。我们的上下文增强的去识别(CEDI)系统捕获句子边界的依赖关系,并完全绕过句子边界检测问题。我们通过深层词缀特征和注意力机制来捕捉输入的相关部分,从而增强了该系统。CEDI系统在2006 i2 b2去识别挑战数据集、2014 i2 b2共享任务去识别数据集和2016 CEGS N-GRID去识别数据集上的表现优于NeuroNER(p<0.01)。所有数据集均包含英文叙述性临床报告,但包含不同的笔记类型,从出院总结到精神病笔记。用深词缀特征和注意力机制增强CEDI进一步提高了成绩。

英文摘要:

Many modern entity recognition systems, including the current state-of-the-art de-identification systems, are based on bidirectional long short-term memory (biLSTM) units augmented by a conditional random field (CRF) sequence optimizer. These systems process the input sentence by sentence. This approach prevents the systems from capturing dependencies over sentence boundaries and makes accurate sentence boundary detection a prerequisite. Since sentence boundary detection can be problematic especially in clinical reports, where dependencies and co-references across sentence boundaries are abundant, these systems have clear limitations. In this study, we built a new system on the framework of one of the current state-of-the-art de-identification systems, NeuroNER, to overcome these limitations. This new system incorporates context embeddings through forward and backward n-grams without using sentence boundaries. Our context-enhanced de-identification (CEDI) system captures dependencies over sentence boundaries and bypasses the sentence boundary detection problem altogether. We enhanced this system with deep affix features and an attention mechanism to capture the pertinent parts of the input. The CEDI system outperforms NeuroNER on the 2006 i2b2 de-identification challenge dataset, the 2014 i2b2 shared task de-identification dataset, and the 2016 CEGS N-GRID de-identification dataset (p<0.01). All datasets comprise narrative clinical reports in English but contain different note types varying from discharge summaries to psychiatric notes. Enhancing CEDI with deep affix features and the attention mechanism further increased performance.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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