1. ICT in Healthcare
Expert Systems

2. Expert Systems
An ICT system that uses artificial intelligence (AI) to make decisions based on data supplied in the form of answers to questions

3. AI An AI is a reasoning process performed by computers to:
Draw deductions
Produce new information
Modify rules or write new rules

4. Neural Network
A NN is a biological system that is used by the brain for learning new things
It allows ICT systems to learn by example like humans
Advantages
Disadvantages
Are good where algorithms cannot be developed
Only suited to different tasks
Can identify structures in data
Time can be wasted and the system can be unpredictable if not chosen carefully

5. An Expert System
Knowledge Base
A huge organised set of knowledge about a particular subject. It contains facts and judgemental knowledge which gives it the ability to guess like a human
A set of rules on which to make decisions (using the if-then structure). The Inference engine does reasoning by manipulating the knowledge base
The user interface presents questions and information to the operator and also receives answers from the operator
Inference Engine
User Interface

6. How to expert systems work
An operator interacts with the UI and answers a series of questions.
Each question gets passed to the inference engine which makes a decision depending on the reply.
The inference engine looks in the knowledge base in order to find the most relevant question/answer
It is then presented to the UI.

7. How to make an Expert System
Build the system from scratch using a software language suited to your task
Program using PROLOG or ASPRIN
Use a piece of development software called an expert system shell
The shell contains a inference engine and user interface, but requires an expert to create a knowledge base
This can be done with little programming skill, but knowledge of an expert system is needed

8. MYCIN – Medicine expert system
Questions the user on symptoms (from a Knowledge base of 500 rules)
Will ask for certain tests if needed
After the symptoms it will advise on the best medication
Can also provide alternative medication with expected success rate

9. Advantages/disadvantages of an Expert System
Consistency – they provide consistent answers for repetitive decisions
No common sense – i.e. If someone had been shot and was bleeding, the system would still look for a cause
Cheaper – they are cheaper than using a human expert such as a GP
Can make absurd errors if data is entered incorrectly, i.e. Weight and height entered the wrong way around
The expert system can consult a much larger pool of knowledge compared to a human
Not able to provide a creative response in certain situations
Available 24/7
Not being able to realised when no answer is available to the problem
The Computer uses all the information it has, unlike a human who can forget
Relies on rules and knowledge being correct. Any mistakes may cause an incorrect diagnosis