HEMAVID: A Flexible Computer-Based Interactive Video Resource for ...

HEMAVID: A FLEXIBLE COMPUTER-BASED INTERACTIVE VIDEO RESOURCE FOR HEMATOLOGY Henry C. Chueh, G.O. Barnett, M.D., Wilson C. Hayes, Ph.D.1, William S. Beck, MD.

Laboratory of Computer Science and Department of Medicine Massachussetts General Hospital Boston, Massachussetts 02114

tiveness of specific methodologies used in training, CBIV has clear and unique advantages in the presentation of visual educational material. As an infant technology, many current CBIV systems in the medical field have been created as experimental systems. This important stage of investigation has resulted in stand-alone applications which usually offer a training course of limited scope. Fcw medical CBIV systems have been integrated with traditional modes of teaching such as lecture or lab, although some investigators promote such an approach [9]. While this approach is desirable in many situations, it complicates the development of the system because a dynamic collaboration of educator, computer scientist, and curriculum managers is essential. We have taken an approach which regards CBIV as an effective system when users view it as a resource, or tool, to solve problems in a novel way. In order to achieve this goal, we designed HEMAVID to be an integral part of a hematology course. By creating a logical bridge from traditional modes of teaching to the more innovative methods of CBIV, we expect users to obtain a clear vision of the system's utility. Then, the CBIV system will not be an isolated resource, and a user can investigate problems and questions arising from lectures, labs, or reading by using the unique facilities of a CBIV tool. Accordingly, the instructor can create problem sets which promote or require exploration of the CBIV system for their solution. This helps to extend instruction beyond the classroom and challenges students to develop a successful attitude towards independent study.

ABSTRACT This paper describes the design and development of HEMAVID, a computer-based interactive video (CBIV) HEMAVID is a PC-based resource for hematology. program that builds and maintains a versatile objectoriented database that indexes a collection of hematology slides residing on videodisc. Access to the database is flexible, allowing its use as: (1) an interactive visual reference, (2) a nucleus for the development and presentation of computer-aided instruction (CAI), and (3) image content in patient simulations. Each image in HEMAVID is associated with expert description, a prerequisite for the program's primary target population of medical students. Research fellows and physicians should also find it an effective resource for hematology review. To that end, the program incorporates an intuitive user interface; controlling the program requires only a "mouse' as a pointing device. HEMAVID's integration of expert knowledge and video imaging technology provides a unique alternative to traditional methods of teaching and reviewing hematological morphology. INTRODUCTION Recently, increasing interest in computer-based interactive video (CBIV) medical systems has been evidenced by the appearance of applications in areas including emergency training, neurologic assessment, and slide-imaging [2,3,4]. Some studies have indicated that CBIV systems are successful and effective [3,5], and a number of educators are generally enthusiastic about CBIV applications [11,121. However, other authors have also pointed out that more methodological research on interactive video training methods is still needed to define and document the effectiveness of the techniques involved [14,15]. The use of interactive video has been considered in medical education largely because of its innovative methods of presenting teaching material. The addition of video display to instruction appears to maintain student interest, and to promote highly interactive sessions [16]. In addition, the combination of video and microcomputer technology allows rapid access to large amounts of visual material. The higher Storage: Access time ratio is more efficient than in traditional media such as slides and atlases. Therefore, while some questions remain about the effec-

BACKGROUND The impetus for developing HEMAVID came from Recently the Harvard-MIT Health Sciences and Technology program (HST) was actively exploring the development of CBIV systems using a variety of available authoring tools. Simultaneously, William S. Beck, M.D., Chief of Hematology at the Massachusetts General Hospital (MGH) was investigating the possibility of incorporating images from the University of Washington's Medical Applications Videodisc: Hematology, 2nd ed. into his HST hematology course. The result of these events was a collaboration between a student researcher, instructors, and administrators to develop HEMAVID. The focus of the project was to provide medical students simple, interactive access to a large collection of hematology slide images which would be hand-selected and described by Dr. Beck. An initial prototype was created using a Digital Equipment Corporation (DEC)/IVIS workstation and DEC VAX/PRODUCER two sources.

Orthopedic Biomechazics Laboratory Department of Orthopedic Surgery Beth-Israel Hospital, Boston, MA 02115

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0195-4210/88/0000/0421$01.00 0 1988 SCAMC, Inc.

software. After a successful interim evaluation with students and instructors, we decided to pursue development of HEMAVID on IBM-compatible microcomputers. METHODS AND PROCEDURES The project goals were threefold; namely, to: (1) provide a simple, usable CBIV delivery system for students, (2) develop an intuitive user interface for such programs, and (3) design a flexible CBIV program architecture which can be enhanced for future needs. To accomplish these goals within reasonable time and cost constraints, we chose to use existing materials whenever possible. Simplicity and practicality were key issues in the design of HEMAVID [1,161. Consequently, we developed HEMAVID for a hardware platform consisting of an IBM-compatible PC with a SONY PVM monitor, an Enhanced Graphics display adaptor coupled with a Videologic IVA-3000 video overlay card, and a SONY LDP-IOOOA videodisc player. All these items are available commercially. When choosing a programming environment, existing authoring packages were considered, but those reviewed were too restrictive in terms of flexible access to a large database of information. Therefore, we chose to use a complete programming language. We selected MUMPS as the development language because of its well-known comprehensive database capabilities [17], and because of the previous success of the laboratory in developing, distributing, and maintaining medical education programs written in the language. On initiation of the project, we targeted three major tasks, or subgoals, which are described below.

Program Interface

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Dictionaries

~Object Managerl

Database of Frame-Objects 1. SchenatI diagrm of the reationship betwem th. us and the database. White wrows Indicat the flow of queie from the usr and/or prorasm to the databae. Black arows indicate th flow of Infation back trom the database to the usr. Note that the objet manr hal all requets for data frm the the databse.

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able to easily design several program interface modules which provide different views of the database. In addition, the encapsulation of the data into objects allows us to modify the structure of the database without making the current programs obsolete.

Database Design The initial task was the implementation of the database. In order to provide transparent support for browsing, authoring, and simulation modules, we created as the core of HEMAVID an object-oriented style of database. While classical object-oriented systems utilize concepts of object classes, inheritance, receiver and sender objects, and messages, the object concept in reality is described by a range of approaches [181. Our intent in using an object-oriented approach was to achieve a separation of the database and methods used to access the database from the rest of the programming effort. We were able to realize this goal by encapsulating each videodisc image within a frame-object construct. Each frame-object contains information pertinent to a single video image, such as the physical index to the videodisc, associated text and graphics, special field information for delimiting areas on a image, and keywords for identification. When the program needs to access a frame-object, a query to instantiate all frame-objects satisfying particular requirements is sent to the object manager. The object manager is a core set of utility programs which provides a flexible interface between the database and program modules which require access to the database. The object manager contains the only code which accesses the database at a procedural level [Fig. 1]. In this way, the programs which provide user functions were developed independently from the database architecture. Once a frame-object has been selected, command messages can be sent to the frame-objects through the object manager. The frame-object can be directed to: 1) show its associated video image, 2) describe various parts of the image, and 3) overlay the image with graphics. The advantage of this system is that programs querying the database need only to utilize simple commands to obtain information about frame-objects. Because of this we were

Development of a User Interface A second, important task was the creation of a user interface which would promote a flexible, problem-driven approach to accessing the information in the image database. In designing such an interface we borrowed common themes in the computer industry such as the use of a pointing device, menus, and minimal keyboard input. Although MUMPS does not have these features built into its environment, it has the capability to support them. Consequently, we developed our own user interface tools within MUMPS, fully expecting to reuse our investment in these software tools in future programming efforts.

Interfacing Programs to the Database A third task was to program the specific end-user functions to be supported. We chose to develop three major functions, or program interfaces: (1) a module which provides direct access to the database for a review of morphology, (2) a topics module which mixes images with text review, and (3) a case simulation and quiz module which offers questions and records user responses. In order to make selections from the database as simple as possible, dictionaries were created which could locate, based on supplied keywords, all instances of appropriate frame-objects. Because the vocabulary of the dictionaries can expand, HEMAVID can be updated to recognize more phrases and terms, as well as utilize new videodiscs. The programming of the morphology review module utilized an extended implementation of the dictionaries. We developed methods to allow for both menu and keyword lookup for frame-objects. To support the hierarchical style of menus, we created a meta-dictionary which

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consists of morphological categories such as megaloblastic anemia. Each category has pointers to child categories, creating a tree of logical categories which can be presented in menus. All terminal categories contain the appropriate keywords to query the database for a collection of frameobjects. The menu system always begins this logical "walk" from the top category. On the other hand, keywords entered by the user are sent directly into the meta-dictionary, and all matching categories are used to construct a menu. Providing the instructional features required the development of an interpreter which could present a previously authored dialog of questions, text, and associated frame-objects. Each dialog can be viewed as a branched tree structure of presentation nodes. At each node, the interpreter directs the flow of the dialog based on either predefined links or user responses. Tools were created to assist authoring of these dialogs.

stance, a choice of red cells will produce a menu of red cell categories, from which the user might choose megaloblastic anemia, and so on [Fig. 2]. The user can back up at any time. At each category level, the user can choose to view all the frames in the category or narrow the search further. Frames can be viewed one at a time or scanned through quickly. Most importantly, each frame is annotated with text and graphics which are accessed by simply clicking the mouse in the region of interest on the image. If desired, all the significant areas of the image can be outlined. By allowing the user to point to an area of an image and obtain an expert description of that area, the program simulates a session with an instructor at a twoheaded microscope, a common teaching device in hematology.

Index and keyword searches are alternative ways to choose morphology topics. Keyword search is particularly powerful because it allows a user to enter a phrase in natural language [7]. The phrase is parsed using HEMAVID's internal dictionaries and is then used to construct a menu of subtopics, if any, from which a user can choose.

RESULTS, HEMAVID is currently a usable CBIV resource which meets the original project goals of providing simple access to a visual database, tools for authoring CAI and patient simulations, and a simple user interface for all aspects of program control. This was accomplished within the intended hardware and software environment. The program is composed of several modules, each of which provides a different view of the central database of images. Users access the modules by selecting it from the program's horizontal main menu. This produces a pulldown menu of the functions available in each module. Menu selections are commonly made using a mouse as a pointing device, although the keyboard can also be used. The main modules are called MORPHOLOGY, TOPICS, QUESTIONS, SYSTEM, and AUTHOR and each is de-

Topics in morphology The TOPICS module of HEMAVID incorporates images from the database into a series of morphology reviews directed at teaching different topics in hematology. A series of text and graphics overlays are coupled with video images to provide an interactive review of morphology on specific topics. Although the program can ask questions and the user may be asked to make note of specific morphology, user response has no effect on the flow of the presentation. Consequently, this module is predominantly didactic in nature. Even though this module is under program control, qualifying it as a Level Three interactive video system, its simple design essentially simulates a Level Two system as it is described in the field [17].

scribed briefly.

Computer-aided Instruction The QUESTIONS module has two sections, Case study and Quiz. Case studies are patient simulations in which a user is asked to be the consulting physician. HEMAVID presents a case history, physical, and lab data including microscopic images where appropriate, information typically available to a clinician. Case questions are targeted to help the user form differential diagnoses and understand how morphological evidence can help in this process. On the other hand, the Quiz function provides a more singular question and answer series where the user is expected to identify specific morphology on an image (by pointing with the mouse) or answer questions about images. This module provides a method for informal selftesting as well as formal, graded testing. Responses can be recorded optionally to a hard disk drive for later evaluation by the student and/or instructor.

Morphology review The MORPHOLOGY module in HEMAVID provides a direct route into the image database by means of menus, an index, or a keyword search. Menus help the user to find specific frames from more general categories. The menus are arranged hierarchically for this purpose; for in-

System data and help features The SYSTEM module allows a user of HEMAVID to track their own usage of the program. Here a user can review which topics, cases and quizzes have been covered, as well as what scores have been obtained from testing. The instructor can use the SYSTEM module to track total time usage of the system with a breakdown by module. Another important utility is HEMAVID's context-sensitive help. By providing appropriate help when needed, the program is much less frustrating for the new user. Help can be obtained at any time by choosing Help from the main menu.

Figure 2. A sample representative screen from HEMAVID. Here the the MORPHOLOGY module is being accessed in a menu search for images from the database. Red cells has been chosen from the top-level menu, and megaloblastic anemias is currently the choice in the subsequent menu.

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Conclusion Future plans for HEMAVID include enhancing the program to take advantage of new digital video technology. This will allow the comparison of several images on the same screen as well as make possible such complex features as zooming into areas of an image. In addition, the use of optical media such as CD-ROM in digital systems will eliminate the need for a videodisc player, reducing the size and cost of the system and offering enhanced update capabilities. Currently HEMAVID is effective in several ways. The program provides simple access to expert description of hematological morphology without the expert present. This significant medical content coupled with a highly interactive visual interface has resulted in its independent use by students at this medical school. HEMAVID's flexible program architecture for CBIV will serve as a platform for future development of similar systems.

Integrated authoring The authoring module of HEMAVID is restricted to authorized users. Functions supported include: (1) the addition or deletion of video images with their corresponding text, graphics, and field annotations (in summary, the editing of frame-objects in the database), (2) the creation of tutorials, quizzes, and patient case simulations. Because the authoring tools are tightly integrated with program, an authoring instructor can use the program tools to search for specific images to place into instructional sequences. Furthermore, the program has full-screen text and graphics editors to aid the author. A new resource As a result of targeting specific user functions and creating a simple and flexible user interface, HEMAVID has been used to complement the HST hematology course over the past two years. The focus on providing pertinent information and content in the program has allowed us to prototype the program even in its earliest stages, even as the user interface was being developed and enhanced.

ACKNOWLEDGEMENTS The authors gratefully acknowledge the support of Roger Mark, MLD. PhD. and Les Comeau of the HarvardMIT Health Sciences and Technology program, and to the program itself for providing funding for this ongoing research. We also thank Hewlett-Packard Co. for their generous grant to the Harvard Medical School educational activities, and Digital Equipment Corp. for their donation of DEC/IVIS workstations used in earlier development.

DISCUSSION HEMAVID is one of the first CBIV systems integrated into a course at Harvard Medical School. In this regard it has been successful and highly regarded by students and instructors. The system resides in a public access area where students and faculty can use the system to review morphology at their own pace. In addition, the instructor can use the system to enhance lectures by showing significant morphology. Unlike a slide projector or a microscope, HEMAVID's interactive access to a large database of images allows the instructor to call up virtually instantly any morphological specimen.

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Limitations While a system like HEMAVID has many advantages when integrated as courseware in a curriculum, it also has limitations. A problem common to all videodiscbased systems is the addition of new images to the videodisc; in this case, a new videodisc must be created -a tedious process. In addition, the hardware required to support such a system is currently prohibitive in cost and/or space for some implementations. Effectiveness of the system Perhaps far more important are questions regarding the effectiveness of teaching from a CBIV system. Is it complementary to more traditional methods of presenting visual material? Some previous studies have answered this question affirmatively. Further objective evaluation of HEMAVID will be required to answer this question for this specific application. We are currently analyzing student usage data recorded by the system. This data will provide feedback on which modules of the program are most successful, and help us evaluate the design of the' user interface. Questionnaires were sent out to students at the end of the hematology course, and response to the system was extremely favorable, with all respondents unanimously agreeing that they used the system regularly and believed it enhanced their learning in the course. In addition, we are investigating the possibility of arranging a control study of the performance of students using HEMAVID vs. students who use traditional microscopy lab to learn morphology. An important aspect of this study will be to offer both options to some students.

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14. Brody PJ. Research on and Research with Interactive Video. Presented at the Ann Mtg of the Am Educ Res Assoc, New Orleans, LA. Apr 23-27 1984. 15. Cushall MB et al. Research on Learning from Interactive Videodiscs: A Review of the Literature and Suggestions for Future Research Activities. Presented at the Assoc for Educ Comm and Tech, Atlanta, GA. Feb 26-Mar 1 1987. 16. Kearsley GP and Frost J. Design Factors for Successful Videodisc-Based Instruction. Educ Tech. p7-13. Mar 1985. 17. Bowie J, Barnett GO. MUMPS - an economical and efficient time-sharing system for information management. Comp Prog in Biomed. 6:11-22. 1975. 18. Wiederhold G. Views, Objects, and Databases. Computer. Vol. 19, 5:37-44. 1986.

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