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Expert System
Last edited |
10/21/2008
Written by Maurice M. Ohayon, MD, DSc, PhD
Sleep-EVAL, an artificial intelligent
computer program, is an Expert System for evaluation and diagnosis of Sleep and
Mental Disorders in general and clinical populations
What is an expert system?
An expert system is a
computer program conceived
to simulate some forms of human reasoning (by the intermediary of an inference
engine) and capable to manage an important quantity of specialized
knowledge.
These capacities for reasoning and management allow the system to
target a small number of relevant hypotheses in the mass of potential diagnoses
and being able to find a satisfactory diagnostic conclusion.
Two characteristics of the expert system are
essential to accomplish this task:
Interests and limits
There are many well known advantages
to using computerized tools and expert
systems:
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reduction of missing data,
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better collection of data,
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no omission of questions,
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no data transcription,
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broader coverage of diagnoses, etc...
Even if some
computerized tools possess some diagnostic trees, the term “computerized tools”
is not synonymous with “expert systems”.
Over
their apparent similarities, they are radically different in terms of both
conception and capabilities.
Indeed, the apparent reasoning process in computerized tools is only an
artifice: The diagnostic trees are predetermined and the software only goes from
one node to another without attempting to look for other paths.
Expert
systems are making their decision during the interview, looking for the optimal
way to reach their conclusions: to make a diagnosis.
Obviously, some limits remain.
Both types of instruments do
not possess the richness of the human language and some may complain of a
inflexibility in wording.
They cannot analyze non-verbal information such as a lack
of hygiene, etc., nor detect a contradiction between a verbal answer and
behavioral cues.
Most computerized tools are unable to analyze temporal
information, for example, to determine which symptom appeared first unless, like
Sleep-EVAL, they have a mathematical preprocessor able to make this type of
analysis.
Conclusion
There are two ways to proceed in order to
improve epidemiological studies using an expert system like Sleep-EVAL:
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The first lies in the improvement of the questionnaire.
This can be accomplished by increasing the quality of data collected by
allowing fuzzy and uncertain answers.
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The second way introduces a sharper knowledge of the
elements belonging to a diagnosis. This can be done by calculating the
relative weight of those elements in the diagnosis of a given pathology.
Quality, frequency, intensity are all elements that provide indication on the
strength of the associative links between the different criteria and the
diagnosis.
References
Ohayon MM.
Improving decision making processes with the fuzzy logic approach in the
epidemiology of sleep disorders. J Psychosom Res 1999;47:297-311.
Ohayon MM,
Guilleminault C, Zulley J, Palombini L, Raab H.
Validation of the Sleep-EVAL
system against clinical assessments of sleep disorders and polysomnographic
data. Sleep 1999; 22:925-30.
Ohayon M.
Validation of expert systems: Examples and considerations. Medinfo 1995;
8:1071-5.
Ohayon M. Knowledge Based System Sleep-EVAL:
Decisional Trees and Questionnaires. Bibliothèque Nationale du Québec,
Bibliothèque Nationale du Canada, ISBN 2-921483-06-8, 1995.
Ohayon MM. Sleep-EVAL, Knowledge Based System for the Diagnosis
of Sleep and Mental Disorders. Registration #437699, Copyright Office, Canadian
Intellectual Property Office. Ottawa: Industry Canada, 1994. (English, French,
German, Italian, Portuguese, and Spanish versions).
Ohayon M. [Expert systems in psychiatry: current nosographic
orientation]. Ann Med-Psychol (Paris) 1987;145(6):521-526.
Ohayon M. [From logical data access to the development of expert
systems] Psychol Med (Paris) 1986;18(4):578-580.
Ohayon M. [Data capture and computer sciences: interest in the
assessment of psychotropic medication] Psychol Med (Paris) 1986;18(4):581-583.
Ohayon M, Fondaraï, J. [Similarities and differences between DSM III
and French psychiatric practice]. Ann Med-Psychol (Paris) 1986;144(5):515-530.
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Sleep-EVAL
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