Health Information Exchange Hl7 Message Building / Parsing And Transfer Key Technologies

Since the data formats and the hardware environments vary between the existing hospital information systems, there must comply with some kind of specific standards in many layers to realize clinical data exchange. Terms and codes should be standardized, syntax wrapping the data must be mutually parsable, and transfer protocol or exchange media should be consistent. Among many health data exchange standards for the text characters, health level 7(HL7) is most successful.A lot of developed countries and areas have constructed the hospital information interchange network based on HL7; however, there is poor experience about HL7 application in China. This thesis is devoted to investigate some key techniques in hospital information interchange based on HL7.An architecture of the hospital information interchange system based on HL7 is designed in this thesis. According to analyzing the function and relationship of the modules, it can be concluded that the HL7 message parser/builder and transmission module are the core of hospital information interchange system, on which this thesis is focused.In this thesis, an I-section-like linked list data structure for HL7 encoding rules is proposed for the message validation checking during the process of message building/parsing. Furthermore, a multilevel pointer linked list data structure of message is devised to store the components of message and to reflect their relationships. In order to develop universal dynamic link library for HL7 building/parsing, an algorithm for HL7 builder/parser is studied based on the above abstract data structure of message. The dynamic link library developed could be connected to other modules as running. Through the application program interface of the library mentioned above, the interconversion of message and application data become easy. An example case for HL7 parser/builder is presented to demonstrate the validation of the algorithm and dynamic link library.On message transmission, the message sending and receiving service across network is completed through programming with winsock on TCP/IP by client -server model.Based on the techniques provided in this thesis, the fundamental process of hospital information interchange, message building - sending - receiving -parsing, has been put into implementation. This thesis also provides a technology basis for the further study on hospital information interchange.