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ComputerunterstützteDiagnoseverfahren
Klaus-Peter Adlassnig
Section on Medical Expert and Knowledge-Based Systems
Core Unit for Medical Statistics and InformaticsMedical University of Viennawww.meduniwien.ac.at/mes
International JournalArtificial Intelligence in Medicine
Editor-in-Chiefwww.intl.elsevierhealth.com/journals/aiim
Computers in Clinical Medicine
• step 1: patient administration– admission, transfer, discharge, and cost billing
• step 2: documentation of patients’ medical data– electronic health record: life-long, multimedia
• step 3: patient data retrieval– medical research databases– quality assurance in the medical institution
• step 4: software-based clinical decision support– quality assurance for the particular patient
Clinical Decision Supportquality assurance of clinical decision making:
for the particular patient
• determination of correct diagnoses– data interpretation and monitoring– single or differential diagnosis
* further diagnostic investigations* all pathological signs are accounted for
• selection of optimal therapies– treatment recommendations– contraindication alerts– drug interaction warnings
• assessment of prognosis– development of illness
• optimal management for the patient– clinical reminders– medical protocols, guidelines, and pathways
symptomssigns
test resultsclinical findings
biosignalsimages
diagnosestherapies
nursing data•••
standardizationtelecommunication
chip cards
anatomybiochemistryphysiology
pathophysiologypathologynosology
therapeutic knowledgedisease management
•••
subjective experienceintuition
knowledge-based systems
information systems
patient’s medical data physician’s medical knowledge
induction
deduction
manypatients
single patient
diagnosistherapy
prognosismanagement
generalknowledge
•••
generalknowledge
telemedicine telemedicineintegration
• Der sog. »schmerzlose Ikterus« ist keineswegs typisch für die Pankreaskopftumoren (weniger als 20%). Vielmehr sind die häufigsten Frühsymptome Schmerzen mit unbestimmten Verdauungsstörungen und Gewichtsverlust.
• Unter den Tumormarkern hat das Ca 19-9 eine relative Semispezifität für das Pankreaskarzinom. Es eignet sich zur Differenzierung von chronischer Pankreatitis und Karzinom ...
differential diagnosis
from: J.A.Pinard et al. (2003) Maternal Serologic Screening for Toxoplasmosis. Journal of Midwifery & Women’s Health 48, 308–316.
Structure of Knowledge-Based Systems in Medicine
medical problem solving methods
medicalknowledge bases
patient’s medical data
• rule-based recommendations• differential diagnosis• laboratory test interpretation • ICU monitoring• device control
• rules with recommendations• disease profiles• interpretive reports• pathophysiological state models• device control rules
• patient data• symptoms, signs, test results• laboratory test results• patient data• patient and device data
expertsystem
informationsystem
Knowledge-Based Methodologyin Medicine
• knowledge– modeling of knowledge
* diagnostic knowledge, therapy recommendations, prognostic information, best medical-practice management guidelines
– modeling based on linguistic concepts* recounted patient history, perception of characteristic signs,
interpreted laboratory measurements, concepts of pathophysiological states, diagnostic, therapeutic, and prognostic concepts
– objective and subjective medical knowledge* definitional, causal, statistical, and heuristic knowledge
– health knowledge* medical standards, work plans, legal requirements, etc.
• data– data-to-symbol conversion
* 1st step to intelligence– recounted, perceived, observed, and measured medical data
* patient history, physical examinations, laboratory tests, and clinical investigations
Medical Knowledge• knowledge representation and processing
– decision tables, trees, and graphs– decision rules and frames
⇒ n-ary relationships between medical entities
• standardization, e.g.,– ARDEN syntax (and FuzzyARDEN)– j.MD– MedFrame– guideline languages, e.g., ARDEN Syntax, PROforma, GLIF
• general basis– ICD—International Classification of Diseases
– SNOMED—Systematized Nomenclature of Medicine
– LOINC—Logical Observation Identifiers Names and Codes
– UMLS—Unified Medical Language System
– FMA—Foundational Model of Anatomy
Towards a Clinical Science
patient’s medical dataand
healthcare processesfor
machine processing
patient’s medical dataand
healthcare processesfor
human processing
≠
…measuring everything measurable and trying to make measurable that which has not been measurable so far …
Galileo Galilei
Knowledge-Based Patient Carepaper chart,
partially electronic
⇑physician
medical knowledge base
expert system
patient record⇑
medicaldecision support logic
electronic health care record
⇑
⇑⇑⇑ ⇑ ⇑health care personnel
fully electronic, integrated system
Numeric and Symbolic Levels in Knowledge-Based Systems
Uncertainty in Medicine• imprecision (=fuzziness) of medical concepts
– due to the unsharpness of boundaries of linguistic concepts; gradual transition from one concept to another
– modelled by fuzzy sets• uncertainty of medical conclusions
– due to the uncertainty of the occurrence and co-occurrence of imprecise medical concepts
– modelled by SigmaCounts (unconditioned and conditioned frequencies of fuzzy sets)
• incompleteness of medical data and medical theory– due to only partially known data and partially known explanations for
medical phenomena– modelled by fuzzy intervalls
Medical problem solving is theprocess of making adequate decisions
with inadequate information.
Anonymous
Genese medizinischer ExpertensystemeMedizinische
Expertensysteme
Medizinische
Künstliche Intelligenz
Medizinische Informatik
Medizin(Kliniker)
KI(Informatiker)
Diagnose
Therapie
Prognose
Patientenmanagement
Informatik
Philosophie
Psychologie
Linguistik
A Sampling of Intelligences—I
from: Gardner, H. (1998) A Multiplicity of Intelligences. Scientific American Presents Vol. 9, No. 4, 19–23.
A Sampling of Intelligences—II
from: Gardner, H. (1998) A Multiplicity of Intelligences. Scientific American Presents Vol. 9, No. 4, 19–23.
Artificial Intelligence (1)
• Definition 1: AI is a field of science and engineering concerned with the computational understanding of what is commonly called intelligent behavior, and with the creation of artifacts that exhibit such behavior.
– from: Shapiro SC. Artificial intelligence. In: Shapiro SC, editor. Encyclopedia of Artificial Intelligence. 2nd ed., vol. 1. New York: Wiley, 1992, pp.54–7.
• Definition 2: AI is the science of artificial simulation of human thought processes with computers.
– from: Feigenbaum EA, Feldman J. editors. Computers & Thought. Menlo Park: AAAI Press 1995, back cover.
Artificial Intelligence (2)
• It is the decomposition of entire thought processes and their separate artificial simulation—also of simple instances of “thought”—that make the task of AI manageable.
• A functionality-driven science of AI that extends humans through computer systems step by step can immediately be established.
⇓artificial-intelligence-augmented systems
– from: Adlassnig KP. Artificial-intelligence-augmented systems. Artificial Intelligence in Medicine 24, 2002, pp. 1–4.
Medizinische Experten-und wissensbasierte
Systeme
MedizinischeDokumentation
Wissensbasierte Überprüfung aufDatenvollständigkeit und -konsistenz,
wissensbasierte Dokumentations-und Informationssysteme
Laboratoriums-medizin
Wissensbasierte Alarm-module, wissensbasierte
Interpretationsprogramme
Wissensbasierte adaptiveBefundungs- und Betrachtungs-stationen, digitale anatomische
Atlanten, wissensbasierte Bildverarbeitung
BildgebendeMedizin
Wissensbasierte Konsultationssysteme
für Diagnose und Therapie, wissensbasierte Monitoringsystemezur diagnostischen Früherkennung
und TherapieüberwachungKlinische
Medizin undIntensivmedizin
Wissensbasiertes Studiendesign
MedizinischeStatistik und
BiometrieWissensbasierte Analyse und
Design von Biomolekülen, wissens-basierte Suchverfahren in molekular-
biologischen Datenbanken
Bioinformatik
BiomedizinischeTechnik
Wissensbasierte Methodenin der Biomechanik,
Robotertechnik
Ein selbstbalancierender, 28gelenkiger adaptiver Zweibeiner;eine elektrochemische Reduktionsfabrik samt gesonderter Stauräume für spezielle Energieextrakte in Speicherbatterien, mit denen dann Tausende
hydraulischer und pneumatischer Pumpen mit anhängenden Motoren betrieben werden;
100 000 Kilometer Kapillaren;... gesteuert wird dieser ganze außerordentlich komplexe Mechanismus mit hervorragender Präzision von einem Gefechtsturm aus; darin befinden sich
teleskopische und mikroskopische Entfernungsmesser, die selbsttätig registrieren und protokollieren, ferner ein Spektroskop und anderes mehr;
das Kommando im Gefechtsturm steht in enger Verbindung mit der klimatisierten Luftaufnahme und der Hauptzufuhr für Brennstoff....
R. Buckminster Fuller, “A Definition of a Man”
in Raymond Kurzweil, „Das Zeitalter der Künstlichen Intelligenz“, 1993 Carl Hanser Verlag, München Wien
1. knowledge representation• formalization and representation of medical knowledge in a
knowledge base
2. knowledge acquisition• knowledge transfer from the expert to the computer
(possible contribution to standardization; filling of “white patches”)
3. inference method• connection between single data of a patient with stored medical
knowledge
4. evaluation of correctness and applicability5. man/machine interface and network integration6. legal aspects
Project Phases
Knowledge Representation• formalization and representation of medical knowledge in
a knowledge base− questions:
∗ degree of structuralization (degree of theory formation in the domain)
∗ type of knowledge (definitional, causal, statistical, heuristic)∗ imprecision, uncertainty, and incompleteness
− formal models:∗ logical models (two- and many-valued)∗ rules (with and without uncertainty)∗ objects (direct representation of complex structures)∗ networks (associative or causal)