Rolf A. Heckemann
The PACS (Picture Archiving and Communications System) at our hospital has been in routine use for several years now. Storing every imaging study digitally together with the radiologist's report resulted in a huge database of diseases and their imaging presentations as well as normal anatomy. This database is, of course, an immensely valuable resource for teaching. However, access for educational purposes is currently limited by the lack of specialised software that presents images and diagnoses in a didactic fashion, along with the background medical information required to understand the underlying conditions. Another important concern is the protection of data identifying the patients studied: images must be anonymised before they can be used in a teaching system.
The Virtual Medical School Project was initiated with the intention to convert this image database into a knowledge base. This knowledge base will form the foundation of a digital network based teaching system for the whole of medicine at every level: the ``Virtual Medical School''.
Today more than ever, learning medicine is a huge challenge. It requires developing a vast range of manual, intellectual, visual and tactile skills as well as taking in large amounts of factual information. As the results of medical research continually impact upon clinical practice, continued medical education is essential. Traditionally, medical education is based on texts, lectures and bedside teaching, self-guided individual learning from books being the mainstay. We believe that traditional medical education, and individual learning in particular, can be complemented with methods of computer aided instruction (CAI) delivered on digital networks. If implemented thoughtfully, CAI could have a variety of advantages:
The most important advantage of CAI is that it opens the road to increased involvement of the learner. The learner sets the pace, chooses the content and selects the mode of presentation (reference/ exploration/ systematic-linear) according to the requirements of his/ her individual preference and situation. Awareness of the process of constructing knowledge is increased, as well as the satisfaction gained from learning. As an overall result, medical teaching can be more effective and efficient.
In order to achieve these benefits, a CAI system must meet certain requirements. On the infrastructural side, a client/ server network architecture is required, where a central server holds the database and most of the software specific to the task of delivering medical content. This approach facilitates continuous content updates and assessment. The network should allow fast transfers with low latencies to avoid waiting times. Finally, the client computers that the learners work on should be easy to set up and economical. Fortunately, the new academic network currently being built on our site will meet these requirements. Thanks to the availability of commodity standards that the internet is founded upon, we will be able to implement the system on widely available, scalable network hardware. On the client side, internet technology will ensure platform independence. This is important as it keeps the costs down and allows adapting to the rapidly developing marketplace for computer hardware and system software.
Designing the software for the Virtual Medical School represents the greatest challenge. At the core of the system lies a large database of images and text (content). The content will have to be labelled with ``meta-information'' to structure, classify and define the relationships between its parts. The next level consists of software modules that access the content and present it according to the meta-information and the specific task they are designed to do, which could be anything from pure textual referencing to a guided tour through a defined subject matter to a three-dimensional annotated image reconstruction of an organ system. Another class of software modules will allow updating and adding to the content database (authoring tools), and in doing so, will have to assure consistency within the meta-information.
For the internal representation of the content, suitable formats are readily available. At this early stage of the project, we are experimenting with various options. Our priority choice will be a format that allows for great flexibility in automated database manipulation, avoids the risk of fixation on certain vendors of software and/ or hardware, and scales well as the project grows.
The Virtual Medical School Project at the Hammersmith Hospital is an endeavour to bring the benefits of digital imaging, communication, interactivity and multimedia to medical education. An outline of the goals of the project, as well as the requirements and problems we are facing have been presented in this text.
Preliminary project URI: http://www.soundray.de/vms/