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Victor Babes UNIVERSITY OF MEDICINE AND
PHARMACY TIMISOARA

• DEPARTMENT OF
• MEDICAL INFORMATICS AND BIOPHYSICS
• Medical Informatics Division
• www.medinfo.umft.ro/dim
• 2007 / 2008

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COURSE 1
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1. MEDICAL INFORMATICS

• MEDICAL INFORMATICS an interdisciplinary field
  studying
• Old definition computer applications in medical
  practice and research
• Modern definition generation, acquisition,
  storage, transmission, processing, protection and
  use of medical information

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2. INFORMATION THEORY
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2.1. INTRODUCTORY NOTIONS

• a) VARIABLES
• deterministic
• well defined values
• by repeating the measurement the same values will
  be obtained
• random (stochastic)
• get different values even will keep the
  conditions
• ex throwing the dice, tossing a coin

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• b) PROBABILITY
• EVENT EXPERIMENTS RESULT
• FREQENCES
• ABSOLUTE - ni
• RELATIVE - ni / N, S ni N
• FIELD OF EVENTS
• EVENTS X1 X2 . . . Xk
• ABS.FREQ. n1 n2 . . . nk
• DEFINITION OF PROBABILTY

EXAMPLES
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• c) FIELD OF PROBABILITIES
• - EVENTS X1 X2 . . . Xk
• - PROBABILITIES p1 p2 . . . pk
• TYPES OF EVENTS
• - certain event - - - - p 1
• - impossible event - - - p 0
• - equelprobabile events pi pj

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2.2. NOTION OF INFORMATION

• a) Definition philosophical category (with high
  degree of generality) defined by properties
• Basic property
• REMOVING AN UNCERTAINTY
• b) Information nature
• its not substance
• its not energy

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• c) Complete approach (triadic)
• matter structure
• Energy support
• information (function)
• d) Utility value of information
• depends on the receptor
• examples

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2.3. AMOUNT OF INFORMATION

• a) FOR ONE EVENT (Shannon)
• Ii log2 (1/pi) - log2 pi
• b) UNIT of measure BIT (Binary digIT)
• 1 bit removes an uncertainty of 1/2

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c) INFORMATIONAL ENTROPY

• AVERAGE INFORMATION OF ONE EVENT IN A MESSAGE OF
  LENGTH N
• Im (n1I1 . . . nkIk) / N
• Im H S piIi
• H - S pi log2 pi

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d) FOR EQUIPROBABLE EVENTS

• pi 1 / k , H Hmax log2 k
• e) Examples one proteic sequence of 100 amino
  acids
• k 20 aa , p 1 / 20
• H 20 ( (1/20) log2 (1/20) ) 4,5 bit/aa
• Itot 100 x 4,5 450 bit
• f) The relation with the thermodynamic entropy
  and order (Maxwells demon)

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2.4. REDUNDANCY

• a) DEFINITION
• - ABSOLUTE REDUNDANCY
• R HMAX - HREAL
• - RELATIVE REDUNDANCY
• Rr R / HMAX
• b) UTILITY to decrease perturbations effects in
  the information transfer process

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2.5. COMMUNICATION SYSTEMS

• a) DEFINITIONS
• MESSAGE the information which is transmitted
• SIGNAL the physical support for the message

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b) THE COMMUNICATION SYSTEM SCHEME S
source (emmitter) R destination (receptor) C
communication channel N perturbations (noise)
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c) TRANSDUCERS device which changes d) MODEMS
MOdulation / DEModulatione) CODING
translation from one alphabet to anotherf) THE
CHANNEL CAPACITY bits/seconds (bps,baud)
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2.6. INFORMATION TRANSFER IN BIOLOGICAL SYSTEMS

• a) THE GENETIC CODE
• DNA, 4 bases (A - T / U, C - G)
• REPLICATION, CODONS
• b) CODING IN NERVOUS SYSTEM
• - FREQUENCY - ON AXONS
• - AMPLITUDE - DENDRITES, SYNAPSES
• c) EXTERNAL INFORMATION - sense organs
• d) INTERNAL INFORMATION - interorceptors

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3. MEDICAL INFORMATION
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3.1. MEDICAL INFORMATION

• PACIENT PHYSICIAN RELATION
• ELEMENTARY CYCLE OF MEDICAL ACTIVITY
• MEDICAL INFORMATION USED IN MEDICAL ACTIVITY
• DATA individual character - facts
• KNOWLEDGE general character - concepts

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3.2. ELEMENTARY CYCLE OF MEDICAL ACTIVITY
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3.3. Medical Information Classificationon
Structural Levels
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3.4. TYPES OF DATA

• QUALITATIVE Anamnesis (descriptive)
• NUMERICAL Laboratory investigations
• GRAPHICAL Biosignals (ECG, EEG)
• SOUNDS Phonocardiogram
• STATIC IMAGES X-Ray, NMR
• DYNAMIC IMAGES movies

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3.5. Operations with information

• Generation (biomedical process or action)
• Acquisition (collection) depends on information
  nature
• Storage data bases, knowledge bases
• Processing for interpretation
• Transmission
• Protection
• Use

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4. CHAPTERS OF MEDICAL INFORMATICS

• Ist PART. DATA
• STORAGE - DATABASES
• ACQUISITION PROCESSING
• NUMERICAL QUALITATIVE BIOSTATISTICS
• SIGNAL PROCESSING, MEDICAL IMAGING
• IInd PART. MEDICAL KNOWLEDGE
• MEDICAL DECISION SUPPORT
• EXTRACTION FORMALIZATION OF MEDICAL KNOWLEDGE
• IIIrd PART. HEALTHCARE INFORMATICS
• INFORMATION SYSTEMS

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END