KHARKOV NATIONAL MEDICAL UNIVERSITY MEDICAL INFORMATICS МЕДИЧНА ІНФОРМАТИКА MEDICAL INFORMATICS

Bases of medical information science

PLAN OF THE LECTURE Aims and tasks of medical information science. 2. Information like the key notion of information science. The bases of informatics. 3. Information science structure. 4. Structure scheme of Electronic Computer. Function principles of personal computers (PC). 5. PC software. Software classification.

Informatics – an area of human activity, connected with processes of data transformation with the help of computers and their interaction with application environment. an area of human activity, connected with processes of data transformation with the help of computers and their interaction with application environment. In the narrow sense informatics is considered as aggregation of data transformation tools consisting of hardware, software and mathematical methods, models and typical algorithms. In the narrow sense informatics is considered as aggregation of data transformation tools consisting of hardware, software and mathematical methods, models and typical algorithms.

Меdical informatics – healthcare studies the process of obtaining, transmitting, analyzing, storing and presenting information using modern informational technologies in medicine and healthcare.

Aims of medical informatics: optimization of information processes in medicine through the use of computer technology, providing improvement of quality of public health care. FOR EXAMPLE: creation of data banks; creation of data banks; creation of screening systems; creation of screening systems; creation of a consultative-diagnostic systems; creation of a consultative-diagnostic systems; development of instrumentation computer systems. development of instrumentation computer systems.

The basic notions of general informatics. - INFORMATION- is new knowledge about the data describing the observed phenomenon and ideas about the world in the form of signs and symbols..

Structure schemeof obtaining information Structure scheme of obtaining information Gathering of data Processing of data Obtaining information Making decisions

With the notion of information is connected such notions as: Message – is information intended for transmission; Message – is information intended for transmission; Data – is information intended for its processing by technical means; Data – is information intended for its processing by technical means; Signal – is any process containing information; Signal – is any process containing information; Communication channel – is the environment where signals are transmitted Communication channel – is the environment where signals are transmitted

Information transmission scheme Isomorphism – is guarantee of information safety when physical media of signal is changing; Noise – is the signals distortion in the result of isomorphism infringement or exterior hindrance.

Coding Any message consists of simple signals combination of certain physical nature Any message consists of simple signals combination of certain physical nature The full set of such signals is called alphabet. The full set of such signals is called alphabet. One signal is called alphabet letter. One signal is called alphabet letter.

The notions of coding Coding – the description of some message with the help of certain alphabet. Coding – the description of some message with the help of certain alphabet. Recoding – the coding of a message into another alphabet. Recoding – the coding of a message into another alphabet. Decoding – the decryption of a message. Decoding – the decryption of a message.

In what way is the information quantity calculated? To select the mathematical function f(x), measures the amount of information you need to know the properties of the information. Consider an event which has k equally likely outcomes. So, unknown f(k) function : Consider an event which has k equally likely outcomes. So, unknown f(k) function should be equal to: 1). f(x)  P=1/k 1). f(x)  P=1/k

2. A message relating what we already know (Р=1), doesn’t carry information: f(1)=0. 2. A message relating what we already know (Р=1), doesn’t carry information: f(1)=0. 3. The more equipossible outsides the event has, the more information about it the message carries, i.e. 3. The more equipossible outsides the event has, the more information about it the message carries, i.e.

4. Information - additive quantity: the information contained in the message that there were two events must equal the sum of information about each of them : f(k 1 k 2 )=f(k 1 )+f(k 2 ). All these requirements are satisfied by function f(x)=log a (x). 4. Information - additive quantity: the information contained in the message that there were two events must equal the sum of information about each of them : f(k 1 k 2 )=f(k 1 )+f(k 2 ). All these requirements are satisfied by function f(x)=log a (x). а) It is a monotonically increasing function; б) f(1)=0; в) function is additive: log a (k 1 k 2 )=log a k 1 +log a k 2. Hartley’s formula: where I (A) - the amount of information about the outcome of event А; k - number of equally probable outcomes; P – probability of the event (P=1/k)

If the event has two equally likely outcomes, the amount of information in the message is equal to 1 bit: k=2; I=log 2 2=1 k=2; I=log 2 2=1 bit R. Hartley, American engineer 1888г- 1970г The measurement unit of amount of information Bit – is the minimum feasible unit of information; Bit – is the minimum feasible unit of information; Byte - is the basic unit used in measuring the volume of information in a computer (1 byte = 8 bits); Byte - is the basic unit used in measuring the volume of information in a computer (1 byte = 8 bits); The following units may also used for measuring information: 1 kbyte = 1024 bytes; 1 Мbyte = 1024 kbytes, 1Gbyte = 1024 Мbytes. The following units may also used for measuring information: 1 kbyte = 1024 bytes; 1 Мbyte = 1024 kbytes, 1Gbyte = 1024 Мbytes.

If events have several outcomes of different probabilities р 1, р 2 … р n, then the average amount of information that is contained in the message about the outcome of any event is calculated according to the formula of Shannon: Claude Shannon American mathematician, where n – the number of possible outcomes of the event about which the message reports; p i – i–th (i=1;2;…;n) p i – is the probability of i–th outcome (i=1;2;…;n) H – information entropy (a measure of the uncertainty of situation). H – is called information entropy (a measure of the uncertainty of situation).

Structure scheme of Electronic Computer

The System Block has a modular structure. The main unit of the system block is the microprocessor, which executes all arithmetic and logical operations and controls the synchronous operation of all other PC units. Types of memory: Random Access Memory (RAM, operating memory) is designed to temporarily store data when the computer is switched on; Random Access Memory (RAM, operating memory) is designed to temporarily store data when the computer is switched on; External long-term memory is intended for long-term storage of large amounts of data and program at hard disk, compact discs, flash discs. External long-term memory is intended for long-term storage of large amounts of data and program at hard disk, compact discs, flash discs. Cache memory is superfast part of RAM. It keeps more frequently used RAM fragments; Cache memory is superfast part of RAM. It keeps more frequently used RAM fragments; Read Only Memory (ROM, BIOS) contains the data inputted during its manufacturing, keeps programs supporting input/output operations; Read Only Memory (ROM, BIOS) contains the data inputted during its manufacturing, keeps programs supporting input/output operations; Complementary Metal-Oxide Semiconductor (CMOS) is a type of internal memory used for storage of computer parameters supplied by an accumulator; Complementary Metal-Oxide Semiconductor (CMOS) is a type of internal memory used for storage of computer parameters supplied by an accumulator; Video memory is used for storing image data displayed on the monitor. Video memory is used for storing image data displayed on the monitor.

PC software

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