SLEEP-EVAL© RESEARCH

Sleep Epidemiology Research & Sleep-EVALTM Diagnosis Expert System


Stanford Sleep Epidemiology Journal

Stanford Sleep Epidemiology Research Center (SSERC)

Psy-EVAL Research

 

"Not everything that can be counted counts,
and not everything that counts can be counted."
Albert
Einstein

 

Sleep-EVAL Knowledge Base

First created | 01/12/1994

Last edited   | 05/11/2012

Summary by Maurice M. Ohayon, MD, DSc, PhD

Reference to cite:

1) 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, Spanish, Finnish, Swedish, Korean, Chinese versions).

2) Ohayon MM. Improving decision making processes with the fuzzy logic approach in the epidemiology of sleep disorders. J Psychosom Res 1999 Oct;47(4):297-311

 

The inference engine uses its knowledge base to pose questions, to infer hypotheses and to deduce diagnostic conclusions

 

 

Decisional Trees and Questionnaires

 

The knowledge base of Sleep-EVAL contains the knowledge representation of several thousand questions assessing:

 

Socio-demographic information

 

 

Sleep/wake schedule

 

For work-days, week-end or merely days off, and vacation periods:

 

Evening activities just preceding bedtime and activities in bed

 

 

Duration of these activities when in bed.

Quality of nocturnal sleep or longest sleep period

 

 

Symptoms or behaviors occurring in sleep

 

 

Sleep habits  and sleep hygiene

 

Insomnia symptoms, daytime sleepiness

 

The Chalder fatigue scale

 

Episodic psychic symptoms

 

Hypnagogic and hypnopompic hallucinations

 

Impacts of sleep problems on driving

 

Impacts of sleep problems on health

 

Daily intake of Substances

 

Name, quantity, frequency, effects, behavioral modifications, cognitive effects.

 

Medications

 

Qualifiers: time, frequency, schedule of intake, prescribers, effects on sleep.
Previous usage of similar drugs

 

Medical history (including medication indications)

 

 

Assessment of social life

 

 

Several pain scales  and questionnaires

 

Psychosis scales  and questionnaires

 

Depression scales (Hamilton, Montgomery-Asberg) and

questionnaires

 

Anxiety scales and questionnaires

 

Cognitive evaluations

 

Mac Nair Scale

 

Mini-Mental State Examination

 

Quality of Life

 

Autonomy Scale

 

Disability Scale

 

Fuzzy Set of Answers

 

Each question must be answered according to a fuzzy set of answers and rules.  The  system is allowed to explore and ask more questions until the subject is understanding the set of questions. When no agreement can be found, a flag is  displayed for the manager of the study.

 

Four types of fuzzy sets are used in order to evaluate:

  • frequency,

  • quantity,

  • intensity,

  • quality,

  • and finally the level of adhesion to the answer by a progressive scale.

 

 

Positive and Differential diaGNOSIS

 

Positive and differential diagnosis of Mental Disorders

According to DSM-IV (American Psychiatric Association, 1994) classification

 

Positive and differential diagnosis of Sleep Disorders

According to the International Classification of Sleep Disorders (ICSD-97) (American Academy of Sleep Medicine, 1997)

 

 

Past and current Organic diseases

 

According to the International Classification of Disease (ICD-10, WHO).

Documentation (clinical, biological, radiological examinations) are collected.

Comorbid conditions are investigated but limited to the current knowledge.

 

 

Health care and health economics

 

A lot of information concerning the costs of the care are collected.

The search is based upon medical acts which could be evaluated at the end of the study.

 

 

References

 

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, Spanish, Finnish, Swedish, Korean, Chinese versions).
Ohayon M.  Knowledge Based System Sleep-EVAL: Decisional Trees and Questionnaires. Quebec National Library, ISBN 2-921483-06-8, 1995.
Ohayon MM. Improving decision making processes with the fuzzy logic approach in the epidemiology of sleep disorders. J Psychosom Res 1999 Oct;47(4):297-311

More Information   

 

Sleep-EVAL Aims

When the first epidemiological survey was launched in 1992, we were looking for an assessment tool that could be used by interviewers with little knowledge about sleep disorders.

 

The Sleep-EVAL Expert System 

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

 

Knowledge Base
The inference engine uses its knowledge base to pose questions, to infer hypotheses and to deduce diagnostic conclusion

 

Inference Engine
Sleep-EVAL is a non-monotonic, level-2 expert system endowed with the ability to make logical connections based on patient information (causal reasoning mode).

 

Fuzzy Logic
Inference models such as probabilistic and fuzzy systems can be used to integrate uncertainty in both symptomatic assessment and diagnostic attribution. It therefore becomes possible to extend boundaries and attribute a degree of certainty to a diagnosis.
A probabilistic model can be easily computed from an existent binary data set.
A fuzzy model can also be calculated from an existent data set, but the model is obviously much more precise when the data are expressed in categorical terms.