4.1.6(c) Uses of ICT in Healthcare/ 3 Expert systems. Starter: Case Study from Lesson 2. Task: Group Work Presentation. Working in groups you will spend 25 minutes preparing a presentation for the class. You must include: Presentation 3 Questions Revision Notes.
Task: Group Work Presentation Working in groups you will spend 25 minutes preparing a presentation for the class. You must include: Presentation 3 Questions Revision Notes • About what artificial intelligence is • What is artificial intelligence • About Neural Networks • How Parallel Processors work • About what an expert system is • About the three components of an Expert System • How expert systems work • Advantages and Disadvantages of Expert Systems • About the Software Languages used to create Expert Systems • Expert system shells • Software languages • About the Medical uses of Expert System • MYCIN • NEOMYCIN You will have 4 minutes to present these to the class
Artificial Intelligence (AI) Allows the computer to: • Draw deductions • Produce new information • Modify rules or write new rules. The computer is able to learn as it stores more and more data. AI Definition: Creating computer programs or computers that behave in a similar way to the human brain by learning from experience, etc.
Neural Networks Biological systems used by the brain for learning new things. Scientists can develop ICT systems making use of artificial neural networks that mimic the way the brain works. They can learn by example just like the human brain which means they are useful for pattern analysis of data classification. • Neural network ICT systems advantages: • Good where algorithms cannot be developed (where it is difficult to develop a computer program because the nature of the problem being solved is not understood enough). • Plenty of examples - the system can learn from. • Structure can be identified from existing data. • Disadvantages: • Suited to certain tasks • Can produce unpredictable results • Learns on its own its operation can be unpredictable.
Neural Networks Vs Ordinary ICT Systems • Ordinary ICT systems are good at: • Fast processing of data • Obeying a set of instructions given as the program code • Disadvantages: • Adapting to circumstances • Dealing with data in parallel (computer like to process data in a linear fashion). • Dealing with imprecise data or data containing erros
How Parallel Processors Work The aim of AI is to get computers thinking like humans. The computer needs to be build in a way that it works like a human brain. Most computers are used to dealing with 1 thing at a time (linear) quickly, tricking us into thinking it is doing more. The human brain is more powerful as it consists of more than 1000 billion nerve cells called neurons through which the brains commands are sent in the form of electric pulses. This enables the brain to process many pieces of data at the same time, allowing is to think, talk, listen and walk all at the same time. The human brain can process in parallel – parallel processing. Supercomputers are available that can carry out parallel processing and these are used for very complex computer tasks where millions of individual items of data need processing very quickly, such as weather forecasts. Using a single processor the problem is programmed as a series of instructions which are processed by the processor in turn.
Expert Systems ICT system that uses AI to make decisions based on data in the form of answer to question. Responds in the way that a human expert in the field would to come to a conclusion • 3 Components: • Knowledge base (Set of knowledge about a particular subject). • Inference engine – (Set of rules on which to base decisions and most of these have the ‘if-then’ structure.) • A user interface – (Presents questions and information to the operator and receives answers from the operator.) Expert system: ICT system that emulates the decision making ability of a human expert.
Expert systems: How they work? • Use a problem solving model - organises and controls the steps to solve the problem. • the If-then rules - forms a line of reasoning. Provided as part of the inference engine. • The knowledge base is all the information an expert uses when arriving at a decision or diagnosis. The more knowledge and experience a human expert has in the field, then the more knowledge can be added to the knowledge base. • A user of the expert system is asked a series of questions e.g. results of tests on the bases of the answers, then answers or diagnosis. http://www.nhsdirect.nhs.uk/
Expert Systems Advantages: • Consistent answers for repetitive decisions. • Cheaper than using a human expert. • Can consult a larger pool of knowledge compared to a human expert. • Available 24/7 • The computer doesn’t forget information. Disadvantages: • No common sense • Can make absurd errors (if the data is incorrectly input) – e.g. if a persons weight and age were swapped around. • Not able to provide a creative response. • Not able to realise when no answer is available to a problem. • Relies on the rules and knowledge base being correct.
Expert system shells Expert system shell – allows people to create their own expert systems without the need for programming skills or the need to start from scratch. • You can either build an expert system: • From scratch using software language • Use a piece of development software called an expert system shell • It is a generic piece of software • The user can use it in different ways for different applications. • It consists of an: • Inference engine • The user interface • Knowledge base - by the builder of system • The word ‘shell’ is used because the user has to build the knowledge base themselves, so it is not considered complete until this is done. It enables people who know little about programming to create expert systems. Software languages Programming languages have been developed that are specialist languages for the development of expert systems. These use English –like statements which are facts along with results and questions. Two languages used are: - PROLOG- ASPRIN
Medical uses of expert systems Medicine is based around the making of decisions based around certain facts so expert systems find many uses in this field. Two of the expert systems used for patient healthcare are: MYCIN and NEOMYCIN. NEOMYCIN Developed to train doctors. It takes the doctors through various example cases, checking the doctors conclusions and then explaining if they went wrong, where they went wrong.
Medical uses of expert systems • MYCIN • The earliest expert system used in medicine. Uses patient’s blood tests and results to enable doctors to pinpoint the correct organism that is responsible for a blood infection. Specific drugs can be given to the patient that will treat that organism. • Before this… you had to grow a culture of the infecting organism, which took 48 hours, and if the doctors waited until the results came through , the patient could be dead. • MYCIN allows junior doctors to make an accurate diagnosis with the accuracy of an expert doctor in the field and this means patients can be put on the correct medication immediately. • Features of the MYCIN system: • 500 rules • Asks further information • Asks for additional laboratory tests • Suggests the best medication to treat • Gives a list of drugs with probabilities • Make a final choice of the drug based on a series of questions the system
Questions • A medical expert system has been developed for diagnosing certain illnesses, which will enable inexperienced doctors to make accurate diagnoses. Briefly explain how it would be possible to test an expert system to check that it is coming to the correct conclusions. (3) • An expert system shell consists of the following 3 components: Knowledge base Inference engine User interface Explain briefly the purpose of each of these three components. (3)
Past exam question (for after the next 2 lessons) 8. ICT is widely used in the Health Service. • Extensive use is made of Expert Systems. State the three main components of every expert system and then describe with examples the advantages and disadvantages of using an expert system in medicine. (7) • Hospitals use ICT to monitor and care for patients. Discuss, using examples, how body scanning, blood tracking and sensors are used in patient care. Discuss the advantages and disadvantages this technology has for patient care. (11)
Help Mini site on this topic: http://www.teach-ict.com/gcse/theory/medicine/student/shome_medicine.htm
Plenary: Worked example • Expert system shells are important in the development of medical expert systems. • Describe the three main parts of every expert system. (3) • Describe, using examples, two advantages of using an expert system in medicine. (2)