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An Expert System for the Use of Occupational Therapists in Making Proposals for Adaptions to Existing Houses

Dr. Alan S. Morris and Dr. Derek Fisher, South Bank Polytechnic, London, United Kingdom

Expert System

It is the function of occupational therapists to make recommendations for the adaptation of existing houses to help physically-disabled occupiers remain independent in their homes. The authors are in the final stage of developing an expert system for assisting occupational therapists in their work of making recommendations for the adaptation of existing houses. The purpose of our expert system is to assist prior to the making of those recommendations.

The Problem Which the Expert System Alleviates

An occupational therapist makes her recommendations as a medical auxiliary. Her expertise is in the alleviation of disability in the home. Alongside the occupational therapist a building expert is needed, who will appreciate whether what is proposed to be done is possible in terms of the existing building.

A building expert can by no means always be on hand when the occupational therapist is deciding on her recommendations however. The occupational therapist will often make her recommendation without due guidance on feasibility from the building standpoint. The building dimension of the problem will only receive expert consideration at some time afterwards.

If the recommendation made is then judged impractical by the building expert, delay and frustration will result while a new recommendation is worked up. It is of importance that this should be avoided: physically disabled people already have much to contend with and time may be short due to progressive disease and short life-expectancy.

The expert system we have developed contributes towards overcoming this problem of possible delay. The occupational therapist needs to know whether her proposals are likely to be feasible: so that if they are not she can amend her proposals before involving the building expert. Our purpose is to give her necessary insight so that her proposals are more likely to be suitable for the building first time round.

Our expert system helps the occupational therapist appreciate whether there are any structural or spatial limitations in the house, or legal limitations, which are likely to rule out the adaptations she has in mind. This will guide her in the proposals she makes and improve her interaction with the building expert whose task it will be to prepare the scheme of alterations and oversee the construction work.

Figure 1. Adaptations to houses: professional expertise.

occupational therapist	building person
Expert in "aids and adaptations for compensating disability in the home"	Expert in the implications for the building of the proposed aids and adaptations...."can the existing building take them?"

The expert system helps an occupational therapist appreciate whether her proposals for adaptation are likely to be feasible from the point of view of the form of construction of the existing building.

Note on the Process of Developing the Expert System

An existing expert system shell ESP-ADVISOR was utilized at the first stage of our work. This shell proved a good start from which to organize the expert knowledge about buildings which the occupational therapist would be consulting. There were limitations to ESP-ADVISOR found which necessitated moving on the develop a purpose-written expert system program of our own.

There was thus a distinct second phase to our work in which we developed our own system. The main programming language used was BASIC. However, since the expert system outputs advice in the form of text it proved convenient to use a word-processor, Wordstar, to format this text. A separate program converts the Wordstar files into a form in which they can be included in the expert system. This combination of programming in BASIC and the facility of ready-made word-processing, suits our purpose well.

The system we are developing is menu driven and the user is afforded complete flexibility to proceed backwards and forwards within the package, exploring the territory, returning if necessary for a repeat-consultation of a particular aspect. The scope of the expert system is indicated in an Appendix to this paper.

Capturing an Expert’s Expertise

The way in which an expert uses his expertise in carrying out his expert function is only partly understood. The process is subtle and complex, not uniform. By observation over a number of years, however, important features of the process have been identified.

There are two features that appear consistently in experts’ armories of problem-solving techniques. An expert
1. takes short-cuts by using rules-of-thumb (heuristics) and
2. knows what question to ask next, depending upon answers that have been given to previous questions: he is able to beam the search towards an answer. An expert will reach the point which is at issue, quite often, after only a few questions.

Using rules-of-thumb and knowing what question to ask next are close to being essentials of an expert system. Our expert system, thus, leads to conclusions by adopting rules-of-thumb used by a building expert while also adopting his pattern of reasoning. Illustrations of these features are given in Figure 2.

Figure 2. Building expert at work (text abridged)

asks....... What do you want?

O.T....... A suspended stirrup-grip

asks....... What is the ceiling structure made of?

advises... on how to find out

O.T....... Concrete

Thinks*.. best not to try drilling that; disturb the
reinforcement; may even be prestressed

says..... let’s think of fixing to walls (a steel support-rail
across the room)

asks.... are the walls 11 cm thick** or more?

* deciding where to go from here
** rule-of-thumb

Expert System Medium Feasible

As a matter of good fortune, our subject matter and purpose lend themselves to the medium of expert systems. This is the case due to a number of reasons. The following aspects of our context and purpose have been significant ones in enabling us to produce an effective working expert system:

consensus\knowledge:     there is a good level of consensus among building experts as to the issues involved in the subject area of the expert system

subject area explicit in character:     the issues involved are readily identifiable in the main, with common-sense or ’surface’ knowledge a sufficiently small element not to diminish confidence in the expert system

the expert system’s focus:     rather than coming to definite conclusions, our focus is on helping our client to reach her own conclusions

ranking and rating between this is reserved for the user, outside the expert system.

different solutions:     The focus of the expert system is on the identification of alternatives each of which is possible.

cross-relationships between these do not normally occur in our subject matter. In our different parts of a solution:context situations do not change according to what has gone before: provision made to overcome handicap in one part of the dwelling does not normally knock-on to alter the implications for provision elsewhere within the dwelling.

Usage and Dissemination

We are optimistic that our expert system will be used by many occupational therapists. Seminars, to become conversant with the expert system, will be held over the months to come.

Appendix: Scope and Arrangement of the Expert System

The arrangement of the program is in sections as follows:

General matters: this section provides information relating to the layout of the house.

Once-only items: a section comprising one-off items - for example, a lift.

Possibly-repetitive items: these are items which may come up on several occasions as an Occupational therapist progresses from one room to another in making her assessment.

Details: this section comprises notes on regulations and construction in greater detail than in the other sections.

External approaches: a section concerning the approach to the house from the street.

Drainage: items comprising the construction, disturbance and protection of drains.