LONGITUDINAL MONITORING OF ECG. Farah Magrabi, Student ... Synchronization with the server at regular intervals is automated by an ActiveX ... For replication in WebECG, an MS Access 97 database has been ... Developer Edition Tools.
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DATABASE REPLICATION AND SYNCHRONIZATIONFOR LONGITUDINAL MONITORING OF ECG Farah Magrabi, Student Member ZEEE, Nigel H.Lovell, Member IEEE, **Branko G. Celler, Member ZEEE, Graduate School of Biomedical Engineering, University of New South Wales, Sydney, Australia 2052. **Biomedical Systems Laboratory, School of Electrical Engineering, University of New South Wales, Sydney, Australia, 2052. E-mail f.magrabiQstudent.unsw.edu.au Abstract - A Web-based ECG monitoring application in which database replication is used to provide an offline review and acquisition facility, is described. Synchronization with the server at regular intervals is automated by an ActiveX Control embedded in the web pages. Confidentiality of patient data is maintained by creating partial replicas and by one-way synchronization. INTRODUCTION The WebECG system is a prototype application that maintains a longitudinal clinical record by monitoring patients in the home [l]. It uses Internet services to facilitate the collection, review, analysis and archiving of a longitudinal ECG record. An intrinsic problem with WebECG is that the user needs to remain on-line during the viewing and acquisition of clinical measurements. This paper describes a technique in which database replication is utilized is order to allow a user to remain offline during the review and acquisition of measurements. A connection to server is only required at regular intervals for synchronizationof a replica with the cenhalized database.
a connection every time the patient reviews an existing measurement or acquires a new ECG. LVPLEMENTATION For replication in WebECG, an MS Access 97 database has been implemented tbrougb the Microsoft Replication Manager, which is installed with the Microsoft Ofice 97 Developer Edition Tools. The Replication Manager uses a component called the Microsoft Jet Synchronizer to create replicas and manage replica sets. The replicas are then distributed to users so that they can be accessed and updated during the review and acquisition of clinical measurements hy the locally installed WinECG software. Synchronization of the replicas is via the Internet using a standard H?TP connection. This is accomplished by configuration of the Web server as a Microsoft Jet Replication Synchronizer. The synchronization is initiated by an ActiveX button control that is embedded on a web page. The ActiveX Control has been written in Borland Delphi 4 and uses Data Access Objects (DAO) programming, an independent object-based data access language used to manipulate Microsoft Jet engine data.
DATABASE REPLICATION AND SYNCHRONIZATION Database replication is a process of sharing data between different locations that are not always connected to each other. This is accomplished by creating copies of the database, called replicas, so that each user can work on their own copy. Synchronization reconciles all the changes and updates the data in each replica set. [2] Replication of the database and synchronization at regular intervals is particularly suited to the WebECG application because, it is a longitudinal monitoring service in which data consistency is not critical at all times and immediate dissemination of updates to the doctor is not required. The system is intended to monitor patients on a long-term basis, where the doctor requires only a summary of long-term trends rather than real-time recordings. Hence a store and forward system is better suited as opposed to real-time continuous updates. Replication of the database also allows the utilization of flexible, low-cost, off-peak communication links. Periodic synchronization of the database with the server provides sufficient updates without the expense and vulnerability of
0-7803-5674-8/99/$10.000 1999 IEEE
DISCUSSION AND CONCLUSION A method that utilizes database replication and synchronization for the maintenance of a longitudinal ECG record by monitoring in the home has been described. Security of the data is not compromized by the creation of replicas because permissions assigned to a user’s logon ID controls access to the database. Patient confidentiality is maintained, by creation of partial replicas and by implementing one-way synchronization, in which only changes to the database are sent and no changes in the server database are received. A clinical trial to evaluate this technology is currently being designed. REFERENCES [l] F. Magrabi, N. H. Lovell, and B. G. Celler, “A webbased approach for longitudinal monitoring in the home,” International Journal of Medical Informatics, vol. 54, no 2, pp. 145-153, 1999. [2] D. Haugbt and J. Ferguson, Microsoft Jet Database Engine Programmer’s Guide, Microsoft Press, 1997.
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