Information Model for Multimedia Medical Record in Telemedicine

Transcription

1 Information Model for Multimedia Medical Record in Telemedicine Xu Guangyou, Shi Yuanchun Dept. of Computer Science and Technology, Tsinghua University, Beijing , P.R.China Abstract: The data used by physicians in patient care is hypermedia in true sense of the word. We propose a Distributed Hypermedia Model(DHM) to logically integrate distributed, multimedia patient data, and provide friendly user interface to give authorized physicians transparent access to these data across the network. This article discusses the architecture of DHM, which can serve as a model for defining and authoring hypermedia medical record in distributed environment. Based on distributed hypermedia medical record, cooperative medicine is supported, that includes asynchronous remote access to the shared data and synchronous consult about a case. Keywords: Multimedia Medical Record; Hypermedia Model; Cooperative Medicine Introduction In modern hospitals, diagnostic information is multimedia. For example, medical records of cardiovascular diseases patient are supplemented by information of different types and formats, such as laboratory result sheets, electrocardiograms graphs, video tape or snapshots on echocardiogram, chest X-ray images, CT, etc.these information are currently storied as papers, print-out sheets, films, or tapes. They are likely to be worn out, lost, and with a low utilization ratio. How to use this data to not only form the patient s medical history, but also provide case study reference for consultation or physician training, is of great value [1]. Advances in multimedia and network technology have made it possible of using these information in a systematic way and telemedicine [9]. There are many fundamental works to do in the way to real sense telemedicine based on patient s records. This paper concerns the information model for distributed multimedia medical record. We are setting up a prototype telemedicine system based on the proposed information model, with which doctors may edit multimedia case research or diagnose reports and consult with each other about cases asynchronously or synchronously. Hypermedia model of medical record Medical record s conceptual structure is with hypermedia feature Various media types include textual data, image, graphics, sound and/or video. With spatial and temporal relationships these elements construct multimedia nodes and they are linked with each other by hyperlinks, forming the presentation scenario of a patient in a doctor s view. On the other hand, these various medical material are distributed among 1

2 different departments of a hospital or even among many hospitals. That is, they are distributed. As to hypermedia document, there must be definition of information units which encapsulate some basic features, including the following: Association of the content (data) itself and its presentation attributes (e.g., for a still image: source data precision, color space, etc.); Synchronization, in space (i.e., on the screen s surface) and in time between components which are to be presented together; Linking between components when the activation at one triggers the presentation of the other one. There are many hypermedia models, e.g., MHEG, HyTime, Internet web approaches, such as WWW and Hyper-G, and Dexter Reference Model as well as Amsterdam Hypermedia Model [2-6]. Each of them has its grounds for existing and developing, along with drawback of itself because none of them has become the well accepted distributed hypermedia standard by now. They have been fairly fully discussed in the literature [8][10]. In this paper, we propose a distributed hypermedia model(called DHM [11][12] for short), which is a model for defining and authoring hypermedia medical record in distributed environment, and supporting several doctors consult about a case asynchronously or synchronously. The architecture of DHM consists of three layers: data layer, container layer, and presentation layer(see Figure 1). Presentation Layer Editor Player Container Layer Page1 Page2 Page3 Data Layer Bitmap1 Audio1 Text2 Video1 Text1 Bitmap2 Figure 1 Architecture Structure of Hypermedia Model Data layer, the lowest layer, represents multimedia data in medical record. Data can be stored in either separate files or in the distributed database, and reside on a single computer or across the network. Data types include text, image, audio, video, animation or any other type, and file format is unlimited within the model. This layer only concerns distributed data access, has no relationship with its representation in the hypermedia document. Container layer, this intermediate layer is called container layer because that it is just like a container(see Figure 2) containing an object list and other information, such as 2

3 background information, constructing a piece of multimedia presentation of a patient.(we call it a page.) Object list holds two kinds of objects: data object and interactive object, which are described in object-oriented paradigm. Each data object represents one particular multimedia data, with attributes and methods of its spatio-temporal and behavioral requirements. Interactive object is the one that receives user input and responds. The most common interactive way in hypermedia system is hotspot. Then button object and action object are defined. Hotspot is no more than a button of various types of a screen area, with some processes it should handle. Action object performs a serious of actions, such as jumping, changing the behavior of other objects, pausing/continuing or stopping the presentation, etc. These actions can be described in Easyscript an embedded simple script language we define to handle the synchronization of objects, user interaction, and linking. Jump action is of the most important, which performs link within the hypermedia network. Jump can be from one object to another object, from one page to another page, and from one hypermedia document to another as well. Interactive objects together with Easyscript comprise links across the hypermedia network. Container Layer Object List Background Image Video Button link to page link to data Data Layer Image File Figure 2 Video File Internal Structure within Page Background information specifies general characters of a page, e.g., size of a page, background style, end style including duration it should remains, link to another page as it reaches its end time, and channels importing shared objects, such as patient s basic information. Spatio-temporal specifications together with EasyScript language well handle the synchronization of objects, user interaction, and linking. And this document model based on page has advances for distributed storage on Web. Presentation layer, consists of two programs: editor and player, which are used to compose and playback a hypermedia page. This is a very friendly user interface for non-technical user. For example, user can define object s time attributes with the aid of timeline scheme. Timeline is a visual tool for defining synchronization, which is simple and powerful. Simple direct friendly user interface is important for physicians since you can t expect them as computer experts. We set up an authoring tool based on DHM and a player program combined in Internet Explorer, which 3

4 can playback hypermedia pages distributed on Web following fttp protocol. This model separates distributed multimedia data and its representation, provides an clear easy way to define an hypermedia document of spatio-temporal relationship and hyperlink among components. The document model based on page has advances for distributed storage on Web. Cooperative medicine Based on the information model, we can create the distributed hypermedia medical information system, and then can realize cooperative medicine. Data servers and doctors are connected across the network(see Figure 3). Different doctors may study a case independently, and they may exchange views with others. This situation is more like asynchronously co-authoring. System provides role-data management and message communications, setting up the connection and communication through network. In this case, how to ensure the pre-defined synchronization relationship in network environment is a key issue. We put forward an hybrid scheme for essential data, such as background information and still objects, transfer first and then playback, as in local environment; for large volume data, such as video, transfer different quality data according to network bandwidth to perform QoS(quality of service). In addition to asynchronously cooperative work, system should also provides synchronously discussing for several doctors consulting about a case. This is implemented through a desktop conferencing platform [13] based on TCP/IP. This cooperative medicine prototype system is under developing. 4

5 Data Server Networking Data Server Conclusion Data Server Based on the similar idea of DHM, a large distributed hypermedia information system was successfully developed last year. We ever performed a co-editing system and a desktop conferencing platform. Now we have a joint project with New South Wales, Australia, and FuWai Cardiovascular Diseases Hospital, Beijing. The telemedicine prototype system is under developing. Reference [1] Ken Chee Keung Law, Horace Ho Shing Ip, SiuLok Chan, An Investigation of a Cost-effective Solution for Multimedia Medical Information Management, Information Management, No. 28, 1995, pp [2] John J. Leggett, John L. Schnase, Dexter Figure 3 Distribution of data and doctors With Open Eyes, Communications of the ACM, Vol. 37, No. 2, 1994, pp [3] Kaj Gronbaek, Randall H. Trigg, For a Dexter-Based Hypermedia System, Communications of the ACM, Vol. 37, No. 2, 1994, pp [4] Kaj Gronbaek, Jens A. Hem, Ole Madsen, Lennert Sloth, Systems: A Dexter-Based Architecture, Communications of the ACM, Vol. 37, No. 2, 1994, pp [5] Lynda Hardman, Dick Bulterman, Guido Van Rossum, The Amsterdam Hypermedia Model, Communications of the ACM, Vol. 37, No. 2, 1994, pp [6] Frank Halasz, Mayer Schwartz, The Dexter Hypertext, Communications of the ACM, Vol. 37, No. 2, 1994, pp [7] Thomas Meyer-Boudnik, Wolfgang Effelsberg, MHEG Explained, IEEE Multimedia, 1995, pp [8] Max Muhlhauser, Jan Gecsei, Services, Frameworks, and Paradigms for Distributed 5

6 Multimedia Applications, IEEE Multimedia, 1996, pp [9] Lutz Kleinholz, Martin Ohly, Supportin Cooperative Medicine: The Bermed Project, IEEE Multimedia, 1994, pp [10] Michael Bieber, Fabio Vitali, Toward Support for Hypermedia on the World Wide Web, Computer, No. 1, 1997, pp [11] Shi Yuanchun, Xu Guangyou, Distributed Multimedia Information Model, Journal of Tsinghua University, Vol.36, No.5, 1996, pp42-47 [12] Pei Yunzhang, Shi Yuanchun, Xu Guangyou, An Interactive Multimedia Model, Proceedings of The 5 th National Conference of Multimedia Technology, Oct.1996, Wuhan, P.R.China, pp [13] Wang Guoyi, Xu Guangyou, Three levels of Collaboration Support in CSCW System, Proceedings of Int. Workshop on CSCW in Design, May 8-11, 1996, Beijing, pp About the authors Xu Guangyou is a professor of Computer Department, Tsinghua University. He is a member of the IEEE. He is the chairman of Department of Multimedia Technology, China Graphics and Image Association. His research interests include HCI and computer vision. Shi Yuanchun is a lecturer of Computer Department, Tsinghua University. Her research interests include distributed multimedia information model, CSCW. She received her Master s degree in 1993, from Tsinghua University. She is now studying for a doctorate 6