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Computer - assisted Instruction (CAI) in Medicine

INTRODUCTION

The potential of computer technology for revolutionizing higher education was analyzed in the study done for the Carnegie Commission in Higher Education in the USA by the RAND Corporation under the direction of Roger Levein. The general picture presented was one of many capabilities available but few of them being utilized. Government agencies, industry and higher educational institutions themselves will have to act to realize fully the computer’s potential, and students must demand that the faculty and admission perform their functions in this regard.

THE LEADNING PROCESS

In order to appreciate the impact of computer technology in medical education (both formal and continuing), it is important to understand the learning process itself. Once we understand this process and the attributes of the various technologies, we will be able to ascertain in which way a particular technology can most successfully strengthen the learning process, and in which, a given technology cannot usefully contribute, or is relatively useless.

Rockart and Michael of the Messachusetts Institute of Technology (MIT), Boston, USA, have proposed an operational learning model as depicted in Fig. 23.1 Facts, skills and concepts have to be acquired, embedded, integrated and tested in the learning process. A learning matrix is depicted in Fig. 23.2, which also shows the most important attributes of the educational tools in each segment of the matrix. For instance, in the acquisition of facts, skills and established concepts (1), cost-effectiveness is the most important attribute and the textbooks and lectures provide the most cost –effective tools. For the embedding process (2) feedback is most important, for which tutorial Paper Programmed Learning (PPL) texts provide the most cost-effective tools. For integration (3), learner control and manipulation of data are important wherein CAI is valuable. For learning new concepts (4) enrichment systems, emulation, and data manipulation are important, where again CAI is valuable. For learning frontier concepts (5) adaptability is most important, and the most cost-effective tool in this area is the professional lecture or guidance.

Medical education had always been a self-study, hence self-study aids are well suited to its objectives. The important educational principles are that: (i) learning should be an active rather than a passive experience, and (ii) students should be given immediate feedback about their progress. One of the primary purposes of CAI is to bring about an automated means for individualized student Instruction while serving large number of student simultaneously. The computer acts as a tutor, as a self-evaluator, as a source of enrichment to the learner while maintaining user control over the process of learning. The computer also plays a supervisory role, reviewing areas where the students’ knowledge is weak, and directing the student to supplementary learning material, covering the areas of demonstrated weakness. In CAI, each student can work at his own pace, receiving simultaneous reinforcement for correct work, and having access to special information and help when problems arise.

PRE –CLINICAL CAI

CAI programs for pre-clinical medical students are basically self-study aids for learning factual information. Most are written in multiple choice format though some are ‘free text’ tutorial interactions. The PLATO (Programmed Logic for Automatic Teaching Operation) CAI system, developed by the Computer-based Education Research Laboratory (CERL) of the University of lllinosis at Urbana-Champaign, has been in use for over two decades. Aplert and Bitzer reported that pre-clinical students using PLATO programs required far fewer hours of faculty instruction (one half or one-third as many ) than students who relied on lectures.

The University of California provides a computer-based self-evaluation program for students for reviewing or testing themselves on course material. The Ohio State University at Columbus offers an independent Study Program (ISP) as an alternative pre-clinical curriculum, which is preferred by more than 25 percent of the class of students. The ISP covers the same medical education material as the lecture discussion program but allows the students independence to determine their rate of progress. The ISP consists of two segments: ‘Normal man’, which can be completed in about six months, and ‘Patho-physiology’, which can be completed in about six months, and ‘Patho-physiology’, which takes about nine months. As an illustrative example, after a student has taken a computer lesson and test in microbiology, the program will give the following assessment.

“Overall, John, you got 25 out of a possible 51”.

1. Knows basic definitions concerning metabolic processes; 2. Understands the relationship between bacterial metabolism and the metabolic processes of other living organisms; 3. Applies a basic definition concerning metabolic processes to the classification of bacteria; 4. Knows specific facts concerning three metabolic processes; and 5. Knows basic definitions describing the oxygen requirements of bacteria.

This list goes on till all learning objectives are covered and the individual question numbers with totals are also given.

“In summary, john, at this stage of your learning, you:

• Have acceptable ability to recall facts and definitions; • Had increased difficulty in understanding terms and relationship related to the media and oxidase test; • Need help in the interpretation and application of that interpretation to metabolic processes; • Demonstrated less than desirable competence in applying the bio-chemical test results in the classification of bacteria”.

VISIBLE HUMAN PROJECT

In this project, a complete, anatomically detailed, three-dimensional representation of the normal human male and female bodies has been acquired from cadavers by transverse CT,MRI and cryosection images. These sections have been taken at intervals of one millimeter for the male, and 0.3 millimeter for the female, providing 1871 and 5189 cross-sections respectively. This data bank (39 giga bytes in size) serves as a common reference point for the study of human anatomy available in the public domain. Image libraries can be accessed via the Internet. (http://www.nlm.nlh.gov/research/visible/visible-human:html)

The data sets are already being applied to a wide range of educational, diagnostic, therapy planning, virtual reality, artistic, mathematical and industrial uses by over 1400 licenses in 42 countries.

Images are an important part of bio-medical knowledge. Pictures facilitate the understanding of biological structure and function, and are an essential component of education research and healthcare delivery. New computer-based technologies are providing an unprecedented opportunity to supplement the traditional two-dimensional images (e.g. pictures in textbooks and plain radiographs) with dynamic three-dimensional images. These images can be viewed, rotated and reversibly dissected in a manner analogous to the physical objects they represent, providing valuable instruction to the student, insight to the researcher and critical treatment planning information to the surgeon or radiotherapist. The Visible Human Project (VHP) was to be the cornerstone for future sets of related digital image libraries including libraries of normal structural variation, collections of diseases and abnormal structures, embryology and pediatrics.

VHP ATLAS OF HEAD AND NECK

The goal of this project is to create a landmark functional and clinical anatomy atlas of the Human head and neck. The project is commissioned by the University of Colorado Health Science Centre. A series of clinically relevant functional anatomy modules are being created as part of the atlas. These educational models are being designed to demonstrate the functional processes involved in facial expression, mastication and deglutition, phonation, hearing and vision. The atlas website will allow the user to interact with the appropriate imagery in order to demonstrate functionally, for example, the function of the muscles that control and move the mandible bone during the chewing reflex. CT/MRI and conventional anatomic graphic materials will be integrated into each module. The module will demonstrate normal musculo-skeletal system function as well as abnormal functional deficits including clinical signs and symptoms. They will illustrate neurovascular relationships through the interactive dissection of anatomic structures and flythrough views. For example, the student will be able to experience a walking tour of the optic nerve and view the distribution of the ophthalmic artery and its branches. These web-accessible modules will emphasise interactivity over passivity. All anatomical structures are being identified by their UMLS unique identifier. Appropriate anatomical terminology and relationships were recently added to the UMLS lexicon. The ultimate goal is to transparent link the print library of functional –physiological knowledge with the image library of structural –anatomical knowledge into one unified single, multi-media resources of health information (Ackerman, M J, 2001).

SIMULATED LEARNING ENVIRONMENT IN ANATOMY AND SURGERY

The current Internet technology is constrained by low bandwidth and ‘traffic jams’. The Next Generation Internet (NGI) is an advanced communication network characterized by high bandwidth, low latency, security and definable quality of service (in terms of reserved bandwidth, priority and defined latency limits). In a new NLM-NGI initiative, two new pilot projects, viz., the ‘Anatomy Work Bench’ and Surgery Work Bench’ are being tested for teaching anatomy and surgery using real-time at many locations on the Internet. A prototype chosen is to teach functional anatomy of the hand in the anatomy work bench and a selection of basic surgical skills such as probing and dissecting through minimally invasive surgery of he trunk, in the surgery work bench. The key pedagogic features are:

• Teaching basic skills through simulation and practice; • Applying the skills in a problem context; • Surrounding with sound pedagogic content (scaffolding); and • Providing an easy and meaningful user interface (http://www.ngi.gov).

ACTIVE LEARNING CENTRE

Since the time of Socrates, it has been recognized that interactivity and feedback are crucial elements in the learning process. However, the majority of medical education sites function as passive repositories of information, with little or no user interaction. Designing questions to provide feedback to the user is usually a very laboratories process. For example, the National Board of Medical Examinations Guide to constructing written test questions is 125 pages long (Case and Swanson, 1999).

Textbooks and videos provide a uni-directional flow of information. Interactive CAI systems have shown superior to the traditional form of teaching. However, most of these programs are expensive and out-to-reach of a student’s budget. An interactive website, Active Learning Centre (ALC) has been developed at the Johns Hopkins University (Turchin and Lehmann, 1999), which offers a novel interactive approach combining remotely authored databases with computer –generated self-assessment tests. ALC is available at http://www.med.jhu.edu/medcentre/quiz/home.cgi> ALC can support an unlimited number of databases, each of them devoted to a specific topic (currently available databases include microbiology, pharmacology, vaccines and cardiovascular medications). The databases store information in a uniform object-oriented format. Each of the databases is created and edited by its author using www.based tools requiring no knowledge of programming language or even HTML. ALC consists of several common gateway interface (cgi) scripts written in Practical Extraction and Report Language (Perl). It is based on a Sun Ultraspace (R ) II Workstation, running Sun OS 5.6 and Apache HTTP server version 1.3. ALC is comprised of several CGI programs, which are detailed below.

a. The gateway script (home.cgi) introduces new users to ALC and provides access to all ALC tools and databases; b. The object presentation script (obj.Present.egi) fetches information on specific objects from ALC databases; c. The database query script (obj.Query.cgi) allows users to run keyword queries against ALC databases; d. The quiz –generated script (quiz-cgi) composes customizable tests using data stored in any of the databases. Users can request different types of questions-multiple choice, matching, essays, etc., select which features of the database object to be tested on (e.g., indications and side effects of drugs) or limit the list to a pre-defined sub-set of object (e.g., only bacteria, not fungi or viruses). The quiz generator can generator thousands of unique questions from its database. Hence, repeated use shows that the improvement in performance cannot be attributed to the users simply memorizing the questions in a previous test run. Users can vary the number of questions asked at a time and choose whether or not to keep score of correct/incorrect answers. This project has shown the utility of interactive medical educational www.sites. The most common request from ALC users was for its further expansion to cover other topics. CAI UNDERGRADUATE CLINICAL EDUCATION

Medical students must not only build up a store of medical knowledge, but also become competent in the applicant of that knowledge to solve clinical problems. During their clinical training, medical students must develop three distinct types of skills: manipulative, inter-personal and cognitive. For developing and testing manipulative and cognitive skills, different types of computer simulation are valuable. Medical students have to learn a variety of diagnostic and therapeutic procedures. The replicable performance simulation is useful where the learning outcome in an expected replication of a specific performance. The role of this simulation has associated with it a guaranteed applicability in the real setting. In medical education and medical practice, there are many situations, especially in emergency medical care, where procedures are definable, consequences of actions or decisions are definable, and there is a certainty of known expectation between each action or decision and its consequences. A good learning tool is the computer simulation of cardiac arrhythmias, and its management by electrical defibrillation or pace-making. A student or intern or resident can gain valuable experience any number of times without jeopardizing the safety of an actual patient.

In the University of South California, Arbahamson and his colleagues have created a sophisticated mannewuin (SIM-l) to teach manipulative skills, but its utilization has been limited. The development of cognitive skills involves the learning of factual data and their application in solving problems. The use of computer technology to teach clinical judgement can be compared to the LINK trainer for pilots. In the LINK, pilots are taught to fly in an automated environment that stimulates both the cockpit of the aeroplane and the flying conditions that the pilot will face. The LINK Trainer is programmed to vary environmental stresses such as weather conditions in an unpredictable but natural fashion. The trainee must adapt to the dynamic stresses and manipulate the control to maintain stability of the aircraft on the correct course. Computer-assisted simulation of patients provides learning opportunities similar to pilot training.

CLINICAL SIMULATIONS

Since it was first introduced more than 30 years ago, clinical simulation has become a popular tool for medical training and evaluation, in a way that is impossible with a paper-based test, particularly in critical care. The modern high fidelity patient simulator consists of a whole body mannequin with integrated electronic patient monitoring; it is controlled by computers capable of simulating numerous clinical scenarios and patient characteristics, and reacting to various interventions appropriately. Simulator training is theoretically superior to conventional training in the management of crisis situations, as it allows unlimited amount of practice in a safe yet environment. Training in clinical skills can be developed, together with clinical competence (Wond, et. al., 2002).

Scoring Performance on Patient Simulations

The process of solving computer-based patient simulations involves repeated cycles of requesting and receiving clinical data from the simulations. The assessment of the clinician’s performance on simulated clinical cases should measure the quality of the clinician’s judgement throughout the evolution of the case. The assessment should be context –sensitive so that credit for very expensive and invasive tests, for example, is given only when justified be previously discovered information. This prevents rewarding of novices for being too thorough and penalizing of experts for their efficiency. Finally, scoring of the simulated cases should also be sensitive to the relative seriousness of the mis-diagnosis.

It is presumed that the clinician requests for information with a diagnostic strategy in mind. The value of information (VOI) is zero whenever the information requested will not change the leading diagnosis in the diagnosis with the highest expected value. Downs, S.M. et al., (1997) developed a method for assessing performance using the decision analysis concept of expected VOI and an influence diagram (as proposed by Howard Matheson in 1981). A graphical representation of the progress of the simulations shows on the horizontal axis, the number of information items requested during the simulation, and on the vertical axis, the points at which data with positive VOI are obtained and their relationship to the type of data gathered (e.g., history, PE, laboratory, etc.).

CASE (Computer – assisted Simulation of the Clinical Encounter)

In the encounter simulation, an initial description of the patient and the setting is the only unsolicited information that the user receives. The stimulation does not present its information to the student, rather it surrenders information as a consequence of student interaction. The student can access information from the computer freely from any section by typing in the appropriate section (history, physical examination, laboratory tests). Once in the desired section, a question of the word for a physical characteristic or the name of a laboratory test will elicit an appropriate response. The diagnosis and treatment plan may be entered when the user has collected a sufficient amount of information about the patient. If the student does not know at any point what to do next, he can ask for HELP, and the computer program will suggest, on the basis of the data already collected, the leading diagnoses along with their Bayesian probability, the best diagnostic test, and the best management plan. In addition, the user may ask for normal values of laboratory tests or for a review of all items collected so far. The students’ input is evaluated and compared with the critical concepts in each section (history, physical examination, laboratory), which should have been addressed in arriving at a diagnosis. The program can also give descriptions of individual diseases under consideration, if asked by the user.

CASE interactions are currently in use at various centers in the USA, e.g., PLATO, University of lllinois at Urbana –Champaign; Ohio State University, Colombus; ;Massachusetts General Hospital, Boston; and Stanford University Medical Centre, Stanford, California. They cover cardiology, respiratory system, gastro-enterology, neurology, hematology, infectious diseases, internal medicine, pediatrics, ophthalmology, orthopedics, obstetrics and hynecology, otolaryngology, etc.

Dynamic Simulations

Apart from static simulation, dynamic simulations are also available which use a branched –tree structure. The computer determines the branching. Programs with such a structure have been developed on cardio –pulmonary resuscitation, hypertensive emergencies, cardiac arrhythmias, and diabetic ketoacidosis. The program provides a reasonably close simulation of the way the actual patient would react to a particular management. For instance, in diabetic ketoacidosis, the student might maintain the patient’s fluid balance by giving appropriate hourly IV fluid yet not give sufficient insulin. The computer program will point out that the blood sugar is still high. Similarly in a program dealing with hypertensive emergencies, the user will learn the clinical pharmacology of the drugs used including dosage, routes of administration, onset and duration of action, contra-indications and side effects. The user’s choice of different therapies will lead to different paths of the programs and different responses from the simulated patient. The user thus get an opportunity to experiment with various drug therapies before he faces the actual emergency, and without jeopardizing the safely of the real patient. Computerized dynamic simulation of clinical management has been successfully used in a training program of paediatric neonatal ventilation management. Computer simulation has recently been used to give doctors experience in running clinical trials, enterprises in which vast amount of money and time can easily be wasted by had planning and management.

Examples of a Case Simulation

The THYROID program developed by Hoffer and Steel at the Massachusetts General Hospital Laboratory of Computer Science (MGHLCS) has a glossary list containing 19 physical examination items, 23 laboratory test items, 23 diagnoses and 14 therapeutic options. The HELP option allows the selection of a teaching message on any item found in the glossary. A CONSULT option will guide the user step-wise to the correct diagnosis. In addition to teaching the diagnosis of thyroid disorders, the THYROID program reinforces two desirable clinical skills: 1. Performance of a thorough history-taking and physical examination, and 2. Concentration on relevant and necessary clinical information. Items which are considered relevant and necessary are listed and the user’s selections are compared with this list. The user is informed as to which of his selections were appropriate, and which of the necessary items he omitted. The computer will also give the lowest cost of investigations through which the diagnosis could be arrived at, and compare it with that incurred by the user. Such programs do not constitute a replacement of the classical instruction, but are of great help in developing a systematic and thorough clinical approach; the program reinforces skills in problems recognition and clinical problem-solving, Kemmis reported favourably on the evaluation of computerized patients’ simulations in use at the Glasgow Clinical Decision Making project at the Glasgow Royal Infirmary. “As students work through the case, there is no doubt that they imagine themselves to be real doctors working on real cases. The plot of the drama they are acting out is built into the machine; it controls the decision to be taken. Identification takes place, not through watching a character on a stage acting out a role before them, but through participation in the play.”

Edward Hoffer has summarized the following benefits of computer simulated patients:

1. Patients with a variety of illnesses are readily and consistently available, either as a pre-defined patient case, or an unlimited number of randomly generated cases. 2. The patient’s progress can be simulated over any desired time span, through dynamic simulations. 3. The student can assume full responsibility for patient care without jeopardizing patient safety. 4. The student can proceed at his own pace without any interference in a way that is private and non-punitive. 5. The student can gain experience in situations where actual practice would not be available or possible. 6. Reinforcement, comment, evaluation, instruction, etc. can be given at any desired point during the interaction. 7. Weakness in clinical techniques or information can be pointed out in a manner conductive to learning.

MEDCAT

MEDCAT is a computer program written in APL and implemented on a 68,000 –based microcomputer, which makes diagnoses, explains each step in its reasoning in response to questions, increase its knowledge and reasoning in response to questions, increases its knowledge and reasoning ability by conversing with expert physicians, and uses its logical and communicative skills to help and evaluate medical skills in order to assist and evaluate medical students in the proper approach to medical diagnosis. When MEDCAT is used to help medical students sharpen their diagnostic skills, the program plays the dual roles of : 1. providing patient data as requested by the student, and 2. functioning as a tutor to evaluate and guide the student’s reasoning. The program can evaluate the need for a test and can indicate that the teaching physician felt it was not warranted. MEDCAT keeps a record of each question that the student asks and constantly compares this with the information necessary to activate each diagnostic node. When conditions are such that an intermediate or definitive diagnosis can be made, the student is asked what the constellation of finding suggests or what competing hypotheses are ruled out by them.

At times, a student may not know what to ask next. He may ask for ‘help’ by entering a null response. The program then looks at the questions that the student has already asked and at the diagnostic implications (points) of each. It selects the diagnostic node that has the most student questions directed towards it. It then prompts the student to draw the correct inference by asking what additional information would be needed to support that hypothesis. Sometimes a student will ask questions in such a sequence that the diagnosis is arrived at very quickly. The program decides whether it was made too quickly by determining whether other competing lines of reasoning have been adequately rules out. If not, it will ask whether the student considered these other possibilities and what evidence would be needed to confirm or exclude them. This is necessary not only to insure that the student reasons in a logical way, but because a patient may have more than one diagnosis.

ILIAD

ILIAD, a diagnostic consultant and patient simulator system, is designed to teach and supplement the problem-solving skills required of a good clinician. It runs on a PC-AT (386) with 2 MB RAM and to 10 MB hard disk. It is an outgrowth of the HELP (Health Evaluation by Logical Processing ) system developed by Dr. Homar Warner on a mainframe which has a clinical database of 500,000 cases. The knowledge base of medical rules comprises 2,000 decision frames 1,350 diagnoses and 5,000 findings and a data dictionary that allows the knowledge base to be integrated with the clinical database. Like a seasoned clinician, the program represents its medical knowledge by grouping findings into clusters that describe patho-physiological states. Clustering enhances the program’s educational value by allowing students to examine the logic used to identify the inter-relationship between the items included. The logic is presented in a pre-digested form (as opposed to a list of raw data items) that can be understood by the medical students as its helps them to understand the manifestation of various diseases and syndromes. The use of clusters also allows the program to generate improved explanations for the selection of diagnoses.

The program, which is most impressive as an educational tool, begins by providing a brief history and chief complaint of a simulated patient. The student must then generate differential diagnostic hypotheses and indicate the most likely working hypothesis. The programme scores performance as the student obtains new information by asking the ‘patient’ questions, studying the results of the physical examination provided by the program and ordering tests. The program’s approach to diagnosis is based on a weighting scheme that directs the student to ask the most important questions first, thereby minimizing the number of questions needed to reach the correct diagnosis. The program provides instant feedback on whether the student is gathering data in an efficient and cost-effective manner. It helps to improve data gathering and interpretation, improves generation and recognition of appropriate diagnostic hypotheses, and improves verification of appropriate diagnostic (raising level of certainty to 95 per cent) and ruling out competing diagnoses. It also recommends a search for cot-effective findings.

QMR (Quick Medical Reference)

QMR, which is a unique microcomputer –based diagnostic program for internal medicine, currently covers 650 medical diseases and 4,300 clinical manifestations, which include patient symptoms, physical findings and laboratory test results. This expert system can be well utilized to learn clinical competence. For example, the program pieces together seemingly unrelated clinical evidence with a powerful function that explores how clinical findings and/or diseases can co-occur in a patient. In addition, to help the clinician interpret the strength of relationships between diseases and findings, QMR has evoking strength (EV) and frequency (FR) numbers. These EV-FR numbers allows the clinician to know the textbook euphemisms like ‘not uncommon’ and ‘usually occurs’. Each finding in the QMR knowledge base has a number of import (ranging from 1 to 5), which qualitatively reflects its diagnostics imperative. The import of a finding addresses the question” “How essential or critical is it to evaluate and explain a finding diagnostically?” For instance, a finding with value 1 rarely requires diagnostic evaluation, whereas a finding with value 5 must always be explained diagnostically.

The QMR program can generate case simulations which help sharpen the diagnostic skills. The cases can be generated at random, or a focus specified by the user, and the user can select how difficult or easy the cases should be. The program can critique the user’s diagnosis by giving a list of findings that are not consistent with the diagnosis; negative findings against the diagnosis; and even suggest useful additional questions that can help in ruling in or ruling out the diagnosis. It is high time that clinical problem-solving skills using computer aids as illustrated above, were taught to medical students. Practising consultants may also use them to maintain their clinical competence.

LEARNING MEDICINE ON THE INTERNET

Undergraduate Education

With Internet access from campus or home, medical students can partake in lessons without the need to conform to a strict timetable or the need to travel. Interactive tutorials on WWW ensure that all students are provided access to the same material, which can be explored at each individual’s own pace. Although interactive in one sense, most education material does not provide the real-time one-to-one interaction between the teacher and pupil that is often critical for memorizing and embedding. Well-constructed tutorials can come much closer to simulating real-life patient encounters than do textbooks. Of course, it cannot be a substitute for a face-to-face encounter with the real patient or practical sessions in the laboratory.

CAL Software

A modest selection of medical education shareware for the pre-clinical student and general public is accessible via the Internet. These programs can be just as interactive as current web-based tutorials but have the advantage of being utilize offline.

Comparative Image Databases

The Internet can offer libraries of images that can be compared with each other, or with a particular case one may have in mind. Such a facility is especially suited to specilization like dermatology, radiology and pathology including hematology. Examples:

• Atlas of Hematology (Ichihashi, T.) <URL: http://www.med.nagoyau.ac.jppath/pictures/atlas.html>

• Dermatology online Atlas (Bittrof, A.). An interactive system for training in dermatology with a database of several thousand colour images which are accessible with a hierarchial key system that permits searching for images by their content. The online resources are useful for training as well as for CME (Bittof, et al., 1997).

<URL: http://www.rrze.uni.erlangen.de/docs/FAU/fakultaet/med/kli/derma/bilddb/db.htl

• The whole Brain Atlas (Johnson, K.A., and Becker, J.A.,) < URL: http://count51.med.harvard.edu/AANLIB/home.html

Some sites also offer CME credit. Examples:

• Pathology cases for diagnosis (Uniformed Services University of Health Sciences)

<URL: http://wwwpath.usuf2.usuhs.mil/surg-path/surg-path.html

• Radiology teaching files (University of Washington) <URL: http://www.rad.washington.edu/>

Where Medical Students Meet

The Usenet newsgroup misc.education.medical provides a forum for discussion of issues related to medical education. Here the medical students have the opportunity to exchange messages with their peers all over the world, contribute to useful discussions, and to publish themselves electronically by writing occasional articles or newsletters. There are several mailing lists for the medical students. Examples:

• MEDFORUM < URL: mailto:llistserv@arizym1.ccit.arizona.edu>send: (personal message _ • MEDSTU-L <URL: mailto:listserv@unmvm.edu>send: A number of resources are specifically available for medical students on the WWW (see Fig. 21.13). these are:

• The medical education page; <URL: http://ww.scomm.net/-greg/med.ed> • The interactive medical student lounge; <URL: http://falcon.cc.ukans.edu:so/~nsween/>.

• A list of worldwide medical schools on the www URL: http://www.anat.dote.hu/~tore/medfak/>.

Under-Graduate Clinical Education

Just as educational modules are available for pre-clinical sciences, the clinical sciences are also similarly served. The WWW acts as a supplement, not a substitute, to the existing teaching methods. Some of the available modules are:

• Primary care teaching modules (Standard University and ECFS) <URL: http://www.med.stanford.edu/school/DGIM/Teaching/modules_index.html

• The online course in Medical Bacteriology (M. Poller) < URL: http://www.amw.ac.uk/-rhbmool/intro.html>

• What is orthopaedics? (Queen’s University Belfast) <URL: http://Drigit.osqub.ac.uk/whatisp>

Post –graduate Education

Even simple e-mail message can be used to educate doctors. It has been shown that by using a basic but fundamentally interactive question and answer system, e-mail can be successfully utilized in helping resident doctors to revise for examinations. These us a growing number of special interest mailing lists (Chapter 19). In the USA, it is possible to earn CME credits on the WWW, via e-mail.

Quality issues in educational resources on the Internet/WWW are being addressed. The Leeds Interactive Medical Education (LIME) project seeks to create an update database of classified and peer reviewed resources, all mapped to the local under-graduate curriculum.

(<Url: http://www.leeds.ac.uk/medicine/lime ). Berry, et al., 1996, used a systematic methodology to assess WWW medical education materials.

Clinical Cases

A number of websites features clinical cases on a regular basis. The user may be presented with a simple discussion, or alternatively work progressively through the clinical history, examination findings, and investigation results before coming to a diagnosis. The issues raised in the case are discussed, as for example: • Case of the month (Medical Network Inc.) <URL http://ww.med.connect.com/home,cas.htm> • Med Round 9 University of Colorado ) <URL: http://www.uchsc.edu/sin/pmb/medrounds/index.html • Reuters Clinical Challenge (Reuters Health Information Service) <URL: http://www.reutershealth.com/clinical/>

VIRTUAL PATIENT PROJECT

Virtual Patients

Virtual patients are those wherein the student role-plays a doctor with a computer-based simulated patient. They have become an increasingly common tool across a variety of clinical disciplines. They range from simple web-based to expensive resource-intensive productions, but there are also difference in their fundamental structure. For instance, Dr. Margaret Bearman from the Centre for Medical Informaton, Monash University in Australia, has created two designs: (1) the problem-solving approach, and (2) the narrative approach. The problem –solving approach aims at teaching clinical reasoning and diagnosis –a well –known example is DxR. The narrative approach is aimed at teaching cause and effect –effects of decisions resulting in various outcomes over time. An example is ‘Virtual Practicuum’ which traces the progress of an HIV positive woman over five years, through a series of virtual consultations.

Several Web-based examples of a narrative design can be found at www.trauma.org.

The ‘Interactive Patient’s is created by the Marshall University School of Medicine . (http://medicus.marshall.edu/medicus.html).

The Jossua Macy Foundation has an ongoing Virtual Patient Project (Rosenmlatt, M.) http://www.josiahmacyfoundation.org/ongoing.

INTERACTIVE MULTIMEDIA EDUCATION IN MEDICINE

Stocking and Mo (1995) have reviewed currently available interactive medical education software packages distributed over CD-ROMs. Floppy disks DVDs. The developers and distributors include individuals, universities, publishers, software companies and pharmaceutical companies.

Virtual Medical School (VMS)

Clinical training has to emphasize mentoring and problem-based, self-directed co-operative learning. By using multi-media and Internet technology, A VMS can provide an integrated assisted learning environment. A VMS was established on the website of the School of Medicine, National Taiwan University. It consists of virtual classrooms, virtual groups, a virtual library and virtual patients. (Heng-sheun Chen, et al., MEDINFO, 2001, p. 1082). Virtual Classroom This provides synchronous video conferencing co-ordinated with live Internet broadcasting; furthermore, the courses can be stored as a synchronized video available on demand after editing. With Web courses in asynchronous classrooms, students can choose courses without the barriers of time and space.

Virtual Student Groups

A web-based interface integrating all the Internet discussion group systems including mailing lists, Net news and bulletin boards can enhance the discussions among students and teachers.

Virtual Library

This provides full text electronic books and journals with key word search functions to simplify the process literature review.

Virtual Patients

They can be created from real cases from the network database. Through an online case editor, the clinical teacher can author computer-assisted learning cases with designed reasoning processes for clinical learning.

ANGEL (A New Global Environment for Learning)

Many medical schools in Europe and America are introducing medical informatics in the under-graduate curriculum, to enable students to equip themselves with the tools of knowledge acquisition for a life-long learning process. The Indiana University School of Medicine has implemented ANGEL, a portal –based curriculum management software system, to teach the core competence in medical informatics.

(London, Susan, et al., MEDINFO, 2001, p. 1089 http://www.cyberlearninglabs.com)

Continuing Medical Education

In recent decades, the tremendous growth of new medical knowledge and techniques has already sorely tried the ability of practicing doctors to stay up-to-date. Through the American Medical Association (AMA/NET), physicians and other healthcare professionals can now use a low-cost computer terminal to obtain the latest information quickly and conveniently in their offices or homes. Information that could take hours to acquire through traditional channels can now be retrieved in minutes. For instance, the Drug Information Base will not only give the user comprehensive information of each of the over 1,100 individual drug preparations by name, but will identify drugs according to indications for therapy, special patients’ circumstances or for certain drug interactions. Critical additions and revisions, and updating of information are done routinely.

The Disease Information Base is designed as a quick reference tool for general practitioners when they are making or conforming a diagnosis, and for specialists in areas outside their immediate specialities. The user can request latest information on a specific disease in its entirely or for certain sub-topics under the disease listing. With the same user terminal, messages can be sent or received, and even filled electronically; information can be distributed to one person or to select groups of people across the country in a minute, quite economically.

The continuing medical education programs, developed at MGH covering at present more than 20 different clinical management areas, provide interactive, self-paced learning, based on computer simulated patient encounters. Cases are designed to convey the essentials of efficient diagnosis and effective patient management, in regard to priority, safety, cost and the temporal sequencing of decisions. These programs meet the criteria for category 1 of the Physician’s Recognition Award of the AMA. More and more such programs are available on micro-diskettes for use on personal computers, and their increasing use can be predicted.

PROBLEM WITH CAI

CAI material in medical education has been written at a variety of institutions, each one preferring its own unique computer language and unique hardware (e.g. PLATO lessons in TUTOT language, the Ohio State University lessons in COURSEWRITER; Massachusetts General Hospital Lesions in MUMPS; Stanford University lessons in a dialect of LISP; and Cornell University MEDCAT written in APL). As a result, programs written in one institution are not usable by others. Programs run on mainframes are not available for microcomputers. Thus, lack of standardization of hardware and associated peripherals, lack of a composite list of available software which inevitably leads to duplication of effort, and decentralized faculty efforts lead to less than optimal utilization of CAI.

One of the most encouraging recent developments in the commercial availability of authoring software which enables teachers to prepare lessons without any prior knowledge of computer programming. We can, therefore, rapidly produce lessons appropriate of Indian requirements. Most programs in USA are on mainframes. For instance, the PLATO lessons are run on CDC CYBER 73-24 and CDC 6,500 with a memory which stores four million 60-bit words. Through an interface unit (CIV) on a standard television channel or microwave link, the mainframe is linked to site controllers, each handling 32 terminals; the actual user is connected to them via a telephone line. Apart from various parts of the USA, PLATO systems are now located in Australia, Belgium, Canada, France, Israel, Korea, South Africa, Sweden, Taiwan and the United Kingdom. Such Intercommunication permits rapid, even instant, exchange of information and teaching material.

The MGH programs are available nationwide in the USA and in other foreign countries over the Telnet Communications Network. This service is available round the clock, seven days a week. Any user only needs to have access to a terminal or a computer which supports modem communication over the dial –up system. In India, 180 Medical Colleges must make active efforts to transport some of the lessons for use in India in the near future. Authoring of lessons should also be initiated, and networking from mainframes as well as stand-alone personal computers should be utilized.

SYSTEM FOR AUTHORING COMPUTER –BASED INSTRUCTION

The affordability and popularity of microcomputers has engendered a need for courseware and tools that facilitate courseware development. Authoring systems have been created to meet this need. For those who are interested in developing courseware in the health sciences, some knowledge abut the available technology will be useful, for making more informed choices about authoring systems. The technology and market are rapidly changing, and hence decisions are not easy to make.

Authoring Alternatives

Courseware can be created by using programming languages, authoring languages or authoring systems. Programming languages such as BASIC are multi-purpose codes that get computers to perform many different tasks. Authoring languages, such as PILOT, are code systems uniquely suited for creating instructions. Authoring systems, on the other hand, involve little, if any, coding. They prompt authors to enter instruction and have underlying programs controlling its presentation. Although some authoring systems do require commands, these are fewer and simpler, and usually displayed on menus when special effects are required.

While most programming and authoring languages offer unlimited use of the computer’s power, there is generally less flexibility with authoring systems; users are constrained by each system’s capabilities. Many authoring systems are powerful and there is hardly and instructional effect that cannot be achieved by some system. Usually, more capabilities mean more complexity and cost.

Generally authoring systems are needed if a substantial amount of courseware development is to be done by persons lacking programming skills, time or interest. But the identification of local needs should be more specific, so that systems can be searched that match them. Once local needs are determined, the selection of an authoring system can be made more efficient by:

1. Review of literature to identify systems that seem appropriate initially; 2. Viewing demonstration of these systems by experts; 3. Getting hands-on experience with those systems that seem to satisfy needs, and 4. Piloting one or two of the most promising systems with a representative group of potential author users. Ultimately a system will be judged by the product it produces and its capability as an authoring tool.

A system output should be defined. Several systems handle only specific lessons types while others are more versatile. For example, one system produces patient management simulation in which students are presented with options for collecting data and making a diagnosis. It has a built-in perfect patient and pre-specified menu and information displays. All test and other data that the students collect are normal except those which the authors can change to simulate disease authors can also alter, delete or add menu choices. These features make authoring easier, but only a narrow range of programs can be developed usually with set display formats. Other systems are geared for only tests or tutorials, though most major ones provide more latitude. Generally systems allowing development of several types of instruction are more desirable.

Those systems which accept open-ended responses may require exact student input or have allowances for spelling and typographical errors. A few systems create only linear instruction while most branch out. There may be limits to screen displays and branches per lesson. If testing capabilities are available, there may be random item presentation and scoring. Usually, flexible systems are performed that can generate both linear and branching instruction.

When Computer-assisted Instruction (CAI) is being used for a class of students, management capabilities are essential to register students and review their performance records by tracking student responses and compiling individual and group test scores. Sometimes scores can be aggregated, individual test items can be analyzed, and item difficult and reliability can be computed. Test security and privacy provisions are also desirable.

Current systems are geared for conventional frame-oriented computer-assisted instruction. As more intelligent programs, or those based on new learning theories appear, another generation of authoring tools may emerge but the ultimate criterion still remains: does the system provide cost-effective authoring and delivery, and create courseware appropriate to educational needs? For wider acceptance and implementation it is essential that authoring systems be microcomputer-based, and create of being interfaced with video cassettes and video players.

INTERACTIVE VIDEO

Just as microcomputers changed computing dramatically, the video disc is altering visual recording rapidly. Combining the two, we have ‘interactive video’, a hybrid just appearing in education, information dissemination and many other fields. Video discs can store very large amounts of information. For instance, two sides of a laser video disc can hold 109,000 images, or an hour of motion pictures (30 frames per seconds x 3600 seconds). The accompanying audio channels can store two hours of recorded sound. Video disc players can locate any frame on the disc within a maximum of 3-15 seconds, depending upon the models.

Since each video frame stored on a video disc contains millions of bits of information, some or all of that capacity can be used to store digital data. Up to eight gigabytes (billion bytes) of digital information can now be stored on a single video disc. It is possible to mix digital, visual and audio information in the same disc, and the microcomputer can find any point on the video disc with in a few seconds. The great potential of interactive video discs for medical education is obvious. In medical education, instructors could reproduce video images Miles Laboratories, working with the university of Washington Medical Scholl, Seattle, has developed a series of instructional video discs on medical topics. Miles has donated these video discs to medical schools and hospitals across the USA, along with hundreds of video disc players.

The Lister Hill Centre for Bio-medical Communications of the National Library of Medicine has developed interactive video disc programs in pathology and radiology. The American Medical Association, in conjunction with the University of Nebraska and others, has developed a series of instructional video discs on such topics as endoscopy and cardio-pulmonary resuscitation.

An interactive video system consists of: 1. a microcomputer, 2. a video disc player, 3. A means of interfacing the two, and 4. Video disc. Apple II, IBM PC, Sony SMC-70, DEC Professional 350 and Hitachi microcomputers have all been incorporated into ‘packaged’ interactive video systems sold by their respective manufacturers. The two major techniques for reading information of the video discs are the Capacitance Electronic Disc (CED) and the laser.

The CED video disc player is designed to read the signal, off the disc serially. It travels along a spiral path very similar to the one on a conventional phono-recording. Hence it cannot move rapidly from one part of another, nor can it find a specific frame or image according to command. Consequently, it is not suitable for interactive video systems.

In the laser video disc player a small, low-powered laser produces a beam of light which travels through a series of lenses and mirrors of microscopic ‘pits’ pressed in a spiral configuration on the disc surface. The disc itself consists of a reflective surface sandwiched between layers of acrylic plastic. The shiny disc surface reflects the laser light back to a mirror which, in turn, reflects it to a photodiode cell which ‘reads’ the pattern of light reflected back to it.

Laser video discs can be formatted in two ways: CAV (Constant Angular Velocity) and CLV (Constant Linear Velocity). Since the CLV disc can only be read in linear play, it is incapable of freeze frames, step motion, slow motion, and frame searching of picture stop, as a result of which it is not useful in interactive video, while the CAV disc is useful. As many as 54,000 frames can be stored on each side of the CAV disc, allowing 30 minutes of motion on each side. The disc is played at a constant speed of 1,800 rpm to achieve 30 frames per second, the NTSC standard.

The production of an optical video disc is as costly as a broadcast quality educational video tape or film. There are three levels of sophistication in the controlling information contained among the material recorded on the video disc. A level 1 disc has no special controlling information on the disc that lets the computer’s built-in memory manipulate the sequencing of the video disc images, thus more complex program sequences can be obtained. A level III disc is the most sophisticated. It is organized in such a way that the sequencing of its images can be completely controlled by an external microcomputer. The development of one level II disc can require a team of 20 people and costs $100,000. There are very few level III video discs with medical content. Even those few that exists use the interactive technology in only a limited way. The next decade will see exciting developments in the evolving technology.

COMPUTER AS AN EVALUATOR

A major advantage of CAI is the capability of the computer to evaluate individual and group performance. The system generates reports regarding the objectives and skills that individual students have not mastered. For example, say 56 percent of the students have not mastered. For example, say 56 per cent of the students in a class missed objective 19 in Unit B. the problem could be that the questions are worded incorrectly or that new study materials are needed. For testing students, questions banks can be organized by setting questions of various types. Authors can tell the system how many questions to present from the question bank for each objective and level. In this manner, it can be ensured that even though tests are randomly generated, each test that is presented will emphasize the same content and be of the same level of difficult. The effectiveness of a test is analyzed in terms of correct responses, difficulty index, discrimination index, high group response pattern and score range, and low group response pattern and score range. I had the privilege of seeing, in Philadelphia, at the headquarters of the National Board of Medical Examinations, a demonstration of the type of computerized examination held from 1988 onwards, with the use of interactive video discs. It is high time that we in India computerized our examinations to ensure objectively and uniformity, and a high standard of examination and evaluation.

COMPUTER-BASED TESTING (CBT)

The National Board of Medical Examination, USA, has pioneered the application of new testing techniques in examinations used for licensure, certification and self-assessment in the health professions. The NBME is now preparing to introduce another major innovation, computer-based testing. The most significant innovation made possible by computer-based testing is ‘CBX: Patient simulator’. The physician uses a computer to interact with ‘patients’ to exhibit characteristic behaviours that are closely related to ‘real-life’ actions in the care of patients. By evaluating, diagnosing and treating the simulated patient, the physician demonstrates a variety of problem-solving and patient-management capabilities that can be reviewed and evaluated in greater depth that is currently possible with traditional examination formats. The examinee has to initiate the diagnostic and therapeutic choices- history, physical examination, and diagnostic tests- and treatment options: the computer records the interchange with the ‘patient’, maps the interactive process and documents the extent to which the physician is making effective or less adequate use of the available hospital or office resources.

When the case is completed, the sequences of choices and decisions are evaluated by a series of scoring programs. The physician’s choices in the management of the clinical problem will indicate the level of knowledge of the underlying disease process, judgement in the appropriateness and timeliness of the test and therapy choices, the degree of skill in coping with unexpected complications, and the efficiency in utilizing the resources available. Large video libraries stored on video discs (up to 50,000) may be used to display visual images (clinical photographs, radiographs, microscopic slides, ECG, etc.) or motion sequences during the examination.

Field trials have indicated that of the available testing methods. CBX provides the best assessment of clinical judgement and patient management skills. CBX is a completely unstructured, uncued simulation of medical practice, unique in the fidelity which it depicts the process and outcome of healthcare. CBX can become a valuable methodology for continuing medical education and the assessment of clinical performance: If the patient’s state of the end of the simulation optimum acceptable, marginal or unacceptable? How much did this encounter cost the patient? How did the cost compare with the optimum cost for safe and effective care? How much unnecessary cost and incurred? Were healthcare resources used judiciously? To how much risk was the patient exposed by virtue of the physician’s decision? How many contra-indicated tests, procedures or therapeutic technique techniques were orders? How logical were the physician’s sequences of decisions? Were decisions made in a timely and logical sequence? Did the physician accumulate the necessary clinical information and data to justify the selection of a particular course of action? These CBX development activities are being funded through a multi-million dollar grant from the W K Kellogg Foundation. The computer software runs in several environments including mainframes and microcomputers, thereby providing maximum availability and probability to health professionals throughout the world, at home, in the physician’s office or in education institutions. Apart from CBX, conventional Multiple Choice Questions (MCQ) can also be delivered via computer. maximal savings are realized by eliminating printing and shipping costs of a paper and pencil MCQ test.