Desirable Features of Rule Based Systems for Medical Knowledge

Agfa Note 15 March 2005

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Latest version:
Stan Devitt
Jos DeRoo
Helen Chen, Agfa HealthCare Inc.

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Copyright 2005, Agfa Healthcare


This note summarizes selected aspects of our investigations into the use of proof-based technologies to validate and manage medical knowledge. In the course of our investigations we have found great benefit in being able to validate, restructure, and extend the data using a variety of tools and proof based engines. As our experience grows in this area, a number of key requirements are emerging. This paper discusses some specific use cases and then re-casts them in terms of requirements on the underlying rule based systems.

Status of this Document

This section describes the status of this document at the time of its publication. Other documents may supersede this document. This document is maintained at Agfa Healthcare.

This document has been prepared as a position paper for the W3C Workshop on Rule based systems.

A list of all current W3C related Agfa Healthcare Technical Reports can be found at

Table of Contents

1 Introduction
2 Details
    2.1 Refactoring
    2.2 Expressiveness.
    2.3 Rapid Authoring
    2.4 Validation.
    2.5 Named Formal Definitions.
    2.6 Extendability.
    2.7 Interoperability.
    2.8 Re-Use of Knowledge.
3 Conclusions


A Bibliography

1 Introduction

The past decade has seen amazing advances in our ability to acquire medical facts. These facts range from new clinical or theoretical discoveries (see [WIHIR]) to our ability to collect and utilize large volumes of patient diagnostic and treatment data. This information has the potential to drastically affect peoples medical treatment and lives in both a positive and negative manner. Proper usage of medical knowledge can literally mean life. Errors of ommission or outright mistakes can mean death or injury.

Our investigations so far have shown that the semantic web is an effective mechanism for representing a wide range of medical knowledge. For example, we have been successful in recasting published clinical guidelines (see [TRIP]) in a usable form using n3 and have been able to use a variety of proof engines to validate clinical contexts against such guidelines.

The sheer volume of largely unstructured, constantly changing facts, procedures and guidelines together with the very human need for assurances of correctness and validation against established procedures make this subject area an ideal area for applications of semantic web technologies.

Our experiments to this point made use of [N3] and rules together with systems such as Euler [EULER], CWM [CWM] and Jena [JENA] to model situations requiring both forward and backward reasoning and take into account some experience with describing the semantics for content MathML [MATHML].

In the course of these investigations we have been able to make several observations concerning the rules, the data, and their interaction.

2 Details

The key items that we wish to take into consideration when reviewing the infrastructure of rules are outlined below.

3 Conclusions

We do not presume to have absolute answers to the questions raised here. Nor do we presume that such a list is complete. An effective design will be the result of balancing these needs and most of all through buy-in by the stake-holders. A satisfactory outcome of such a workshop would be some consensus of where to draw the line and an explanations of how the emerging design addresses each of these questions. We look forward to working with participants to move forward in an organized fashion.

A Bibliography

CWM, , a general-purpose data processor for the semantic web, W3C.
Euler, , a backward-chaining reasoner enhanced with Euler path detection.
Jena - A Semantic Web Framework for Jena, an opensource project grown out of work with the HP Labs Semantic Web Programme.
Semantic Web Tutorial Using N3, W3C.
David Carlisle, Patrick Ion, Robert Miner, Nico Poppelier, Mathematical Markup Language (MathML) Version 2.0 (2nd Edition) World Wide Web Consortium, 2003 (
John S. Devitt , Ph.D, Helen H. Chen , Ph.D, Jos De Roo , ir., Using the Semantic Web and Proof Technologies to Reduce Errors in Radiological Procedure Errors, , TRIP Conference & Workshop Poster Abstracts, January 31, 2005
Futures Symposium, Futures Symposium Archive, January 11, 2005.