GCN with External Knowledge for Clinical Event Detection

Abstract

In recent years, with the development of deep learning and the increasing demand for medical information acquisition in medical information technology applications such as clinical decision support, Clinical Event Detection has been widely studied as its subtask. However, directly applying advances in deep learning to Clinical Event Detection tasks often produces undesirable results. This paper proposes a multi-granularity information fusion encoder-decoder framework that introduces external knowledge. First, the word embedding generated by the pre-trained biomedical language representation model (BioBERT) and the character embedding generated by the Convolutional Neural Network are spliced. And then perform Part-of-Speech attention coding for character-level embedding, perform semantic Graph Convolutional Network coding for the spliced character-word embedding. Finally, the information of these three parts is fused as Conditional Random Field input to generate the sequence label of the word. The experimental results on the 2012 i2b2 data set show that the model in this paper is superior to other existing models. In addition, the model in this paper alleviates the problem that “occurrence” event type seem more difficult to detect than other event types.