Extraction of Clinical Temporal Relation Fusing Dependency Syntax and Entity Information
In clinical texts,temporal relation is crucial to the study of patient's conditions and treatment options.The current temporal relation extraction is based on the simple temporal comparison,and only four temporal relations are judged.Considering that there are still a large number of complex times and relations in Chinese clinical texts,the existing temporal relation extraction task cannot fully express the temporal relation of clinical events,referring to the CTO temporal ontology,the extraction task is expanded to complex time relationship extraction.At the same time,aiming at the semantic complexity of Chinese clinical texts,a model integrating dependency syntax and entity information is proposed to learn the overall information and entity information of Chinese sentences.The model scrambles to design dependency feature matrices for intra-sentence temporal relation and inter-sentence temporal relation to guide BERT's encoder to aggregate global and local information,derive sentence representation vectors on which rich entity information is extracted using the inner product and Hadamard product.Finally,the sentence information and entity information is imported into the classifier to determine temporal relation.Compared with baseline model and other deep learning model,the effectiveness of the proposed model is demonstrated.
temporal relation extractionself-attention mechanismdependent syntaxlocal informationentity information