The Research And Implementation For Resident Doctors Workstation Based On Windows DNA And COM+

The primary purpose of Hospital Informatization is to deliver theinformation of the patients comprehensively and quickly so as to offer theall-dimensional service for doctors making diagnoses and hospitalmanagement. But the all-dimensional service cannot lack the combination ofIT and medical science, i.e. the informatization of clinical management.HCIS, with the focus of collecting, storing, showing and processing theinformation of patients, is an information system aimed at offering servicesfor the clinical medical personnel and medical work for technical offices.Establishing itself on doctors' routine work, serving for doctors clinicalpursuits, the doctors workstation is a brand-new and authentic clinicalinformation system. At present, HIS (Hospital Information System)manufacturers are making a new round of development and popularization todoctors workstation, inspection reporting system and image system. Becauseof the cutthroat competition of hospitals, business strategy needs changingaccordingly. It brings about increasing complication of software andextensive consumers' orders and it makes both the cycle and cost ofimplementation rise drastically. Therefore, the key of this round ofcompetition is to implement standardization, stability of products andextendibility. In this sense, HIS products' extendibility, stability andimplementing standardization are needed. At present, ensuring medicalsecurity and promoting medical care are the central tasks of hospitals. Itmakes an urgent request for developing a stable, efficient and highly flexibledoctors workstation.The resident doctors workstation system discussed in this thesis is asub-system of the Hospital Information System in SanJiu Hospital, ShenZhen(999 HIS). Adopting the technique and method of object-orientated modeling,this system can quest customers' demands properly and lay a good foundationfor successful development of the system and post-maintenance of thesoftware. Using Windows DNA and COM+ technique to design and realize,it accelerates the speed of development and makes the system of highefficiency, extendibility and security, etc.After studying and probing the current state of development of doctorsworkstation, the thesis puts forward the Windows DNA solution basing onthree-layer structure and it applies the modularization program design basingon the thought of component program of COM to instruct the development ofthe system. In this way, it can construct an application system of highlyreliability, extendibility, thus resolving the existing difficulties that confrontHIS system technique.In the first place, the thesis introduces the developing process ofstructure―the introduction of two-layer structure of client/server model andits advantages and disadvantages. Then it introduces three-layer structure, itsoperational mechanism and advantages. Windows DNA totally bases onthree-layer service model. It divides the application system into three layers:the presentation layer, the business layer and the data access layer. The thesiselaborates the constitution and advantage of Windows DNA and makes anextendable design of it. This offers a good thought for the later design of thedoctors workstation. Next the thesis lays stress on COM+ ―the coretechnique of Windows DNA, introducing COM+ structure and the service itoffers. By means of these services, the attribute of component can be set upto realize more powerful function of COM.After mastering Windows DNA basing on three-layer structure, it can beused to design this system. After analyzing the main professional logic andwork flow of resident doctors workstation, Rational Rose 2002 can be used tomodel for the system and instruct the developing of it. While designing, theinterface's design of middle business component is focused on, because thebusiness layer is the core part of three-layer structure, and the interface is theonly way directing to external service. The interface of component is ofinvariability. The interface that is already designed is not allowed to berevised, or other current applied transferring error can be caused. Use PowerDesigner 8 to design background database structure and try to keep theintegrity of the data.According to the relationship of one to many and many to many frequentin the relational database, the thesis also discusses the realization ofcomplicated Transaction. By setting a special Transaction manager, theintegrity and correctness of data can be guaranteed.In the thesis, after completing the design of the system, it comes to realizedoctors workstation system. In the process of realization, the thesis discussesCOM, DCOM and MTS techniques deeply, giving realizing methods and thekey codes of presentation layer, business logic layer and the data layer. Afterfinishing the development of business component, allocate and deployCOM+ application program on the special component server by way ofcomponent service management tool in order to offer services for the clientprogram. A well-designed system should be of elasticity and security.According to the experience accumulated in the process of developing, thethesis puts forward several solutions to promote elasticity and security.When the clients establish an object with the sign of Just-In-Timeactivation, the practical example enabled by COM+ turns the agent back toclients and they call it as usual. When the object finishes its work, COM+sets the practical example of the object as deactivated. However, the agent ofclients, the stub of server and the ORPC channel connecting them still exist.When clients transfer server, the server communicate with stub by thechannel and a new practical example of the responding objects is enabledimmediately. The result of JIT (Just in Time) can recycle resources, and theadvantage is to ensure correctness of transaction. The thesis provides theprinciple and implementation procedure to promote elasticity with theapplication of JIT.The thought of object pool is to make some components signed as"pooled". When the COM+ application program that contains thesecomponents is enabled for the first time, COM+ establishes some objects andput them into a pool. When clients establish an object, COM+ checks theobject pool first. If there are some assigned objects that can be used, COM+no longer establishes new object, it enables one in the pool;if there are not,COM+ will establish new object. Object pool technique reduces the time thatclients' request and increase the through put capacity of program. The thesisdiscusses the object pool technique profoundly.Generally, there are several component servers. In order to take fulladvantage of the server resources and introduce the CLB technique, the thesiselaborates the principle and application of CLB.Then the thesis probes the security technique basing on Character andoffers the methods to promote component security using COM+.In the end, a conclusion of the thesis is made: there still exist someburning questions to promote the system operating efficiency and thedesigning process needs perfection.