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Publications (2)1.13 Total impact

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    Article: Does size really matter--using a decision tree approach for comparison of three different databases from the medical field of acute appendicitis.
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    ABSTRACT: Decision trees have been successfully used for years in many medical decision making applications. Transparent representation of acquired knowledge and fast algorithms made decision trees one of the most often used symbolic machine learning approaches. This paper concentrates on the problem of separating acute appendicitis, which is a special problem of acute abdominal pain, from other diseases that cause acute abdominal pain by use of an decision tree approach. Early and accurate diagnosing of acute appendicitis is still a difficult and challenging problem in everyday clinical routine. An important factor in the error rate is poor discrimination between acute appendicitis and other diseases that cause acute abdominal pain. This error rate is still high, despite considerable improvements in history-taking and clinical examination, computer-aided decision-support, and special investigation such as ultrasound. We investigated three databases of different size with cases of acute abdominal pain to complete this task as successful as possible. The results show that the size of the database does not necessary directly influence the success of the decision tree built on it. Surprisingly we got the best results from the decision trees built on the smallest and the biggest database, where the database with medium size (relative to the other two) was not so successful. Despite this we were able to produce decision tree classifiers that were capable of producing correct decisions on test data sets with accuracy up to 84%, sensitivity to acute appendicitis up to 90%, and specificity up to 80% on the same test set.
    Journal of Medical Systems 11/2002; 26(5):465-77. · 1.13 Impact Factor
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    Article: Meta Data Dictionary to Link and Reuse Knowledge-based Systems in Medicine
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    ABSTRACT: . Knowledge-based systems can hardly be introduced in clinical routine, if they do not operate directly with clinical data. Problems of terminological integration and correct application of decision-aids are discussed. This paper describes an approach to integrate different types of published decision-aids in a knowledge-based system linked to clinical documentation via a meta data dictionary approach. For a prototypical application decision-aids from the clinical field of acute abdominal pain were chosen. The meta data dictionary approach is compared to other existing systems, dealing with terminological integration via ontologies. 1. Introduction Data Dictionaries in medicine have been established in different areas, especially in clinical information systems (CIS) (HELP: PTXT [1], WING: GMDD [2]) and Knowledge-based Systems (KBS). They contain the controlled vocabulary of the domain of application and are used to support unambiguous medical data with respect to time and among diffe...
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