1 Staffordshire University, School of Art and Design. 2 Rehab Robotics Ltd. 3 University of Reading, Department of Cybernetics. 4 Trinity College Dublin.
GENTLE/S Project: Design and Ergonomics of a Stroke Rehabilitation System P. Hawkins1, J. Smith1, S. Alcock1, M. Topping1,2, W. Harwin3, R. Loureiro3, F. Amirabdollahian3, J. Brooker3, S. Coote4, E. Stokes4, G. Johnson5, P. Mak5, C. Collin6 and B. Driessen7 Abstract Cerebral Vascular Accidents such as haemorrhagic and ischaemic stroke are a leading cause of disability, and affect around 200 per 10,000 of the population particularly affecting older people. This paper describes the development of a patient interface and therapist workspace, for a new prototype clinical system using haptic interface technologies for machine mediated upper limb stroke rehabilitation.
1 Introduction The GENTLE/S project is a three year project in the European Community Framework 5 programme. The project started in Feb 2000, and is within the Quality of Life Programme, under the key action 6 “The ageing population and their disabilities”. The main objectives of the GENTLE/S project are to: • • 1
explore and identify “best practice” therapies that can be machine mediated; motivate and promote the functional recovery of the patient;
Staffordshire University, School of Art and Design Rehab Robotics Ltd. 3 University of Reading, Department of Cybernetics 4 Trinity College Dublin 5 University of Newcastle 6 Royal Berkshire Hospital 7 TNO Institute of Applied Physics 2
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• • •
develop a clinical prototype based on haptic interaction technology; design and develop the technology to be safe, usable and reduce healthcare costs; plan for effective exploitation of the technology.
2 User Needs Evaluation This is a very important and continuous part of the project. It initially consisted of a review of existing stroke rehabilitation techniques, any existing machine mediated stroke rehabilitation projects and commercially available products. A user needs workshop was organised and contact was made with a local stroke association in Staffordshire, members of which provided valuable input into the project. Therapists and patients were interviewed to find out their requirements and expectations for the prototype systems. Some early concept drawings and rough and ready prototypes were used as discussion points. Most therapists and patients were enthusiastic about a system which could potentially deliver both neuro and motor rehabilitation and measure any recovery. Therapists stated requirements which included, seating the patient at a table and fully supporting the affected limb, whilst performing various types of exercises, combined with challenging and motivating activities, both real and virtual. With the aim of helping the patient recover normal upper limb functions such as, locating a target, reaching, grasping an object and postural control, as their recovery is of extreme importance in every day manipulative tasks. As no two patients have identical problems, which can range from the loss of fine finger movements only, to the loss of all movement in the arm and shoulder, the system must be capable of providing individual rehabilitation programmes. Patients were asked which upper limb activities they would most like to achieve or improve on, the main findings were eating and drinking, writing, washing oneself, dressing and household activities.
3 Design and Ergonomics Two prototypes were to be constructed for two pilot clinical trials, the first at the Adelaide and Meath Hospital in Dublin, the second at the Royal Berkshire Hospital in Reading. Information from the user needs evaluation was incorporated into this design stage, resulting in a design specification. The main component of the prototypes is the Haptic Master robot arm supplied by Fokker Control Systems. An early decision was made to position the Haptic Master at the side of the patient to make the most efficient use of the robot arm workspace, in relation to the patients upper limb range of movement. This arrangement posed some interesting design challenges for setting the prototypes up easily for left and right arm patient therapy. A therapy session might be 30-45 minutes long and patients could be treated in any order of affected upper limb, so the prototype might have to be set up
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approximately every hour by the therapist. The overall aesthetic of the prototype was also an important consideration, with ideally a non-threatening appearance. Ideally the prototype would be fully adjustable to suit the anthropometric measurements of individual patients and therapists (design for all principle) but for the purposes of the prototypes a compromise was made and mostly mean adult anthropometric data was used.
3.1 Rapid Prototype Design Specification • • • • • • • • • • •
stationary stand for the Haptic Master robot arm and controller; fully adjustable patient chair with harness, for good patient posture; anti-gravity patient arm support mechanism; patient wrist to Haptic Master robot end effector attachment mechanism and safety release mechanism, both patient and therapist activated; patient activity table, for manipulation of real objects; 22-inch monitor for the displaying virtual objects and environments, positioned for optimum viewing by the patient; therapist computer workstation with emergency stop button; easy and safe transfer of the patient onto the prototype, using various hoists if required; easy set up of the prototype by the therapist for left and right arm patient therapy; user friendly prototype, which is easy to use for both therapist and patient; compliance to any relevant health and safety standards on medical electrical equipment.
3.2 First Rapid Prototype Concept Designs Different partners agreed to design various elements of the specification. Many sketches were done showing various concepts for and different arrangements of the items listed. Some rough and ready prototypes were constructed to test various design ideas, which were evaluated with input from users.
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Figure 1. Concept design sketch for the first rapid prototype
3.3 First Rapid Prototype Final Design The development continued until each element of the specification was refined to an acceptable level, when it could be incorporated into the chosen overall detailed design.
3.4 Pilot Clinical Trials of the First Rapid Prototype The trial in Dublin raised a number of issues and problems including; reducing the overall footprint of the prototype, improving transfer onto the prototype for the patient. The possible use of patient wheelchairs and making the prototype easier for the therapist to set up for left and right arm patient therapy.
Figure 2. First rapid prototype installed – Adelaide and Meath Hospital, Dublin
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3.5 Second Rapid Prototype Concept Designs These incorporated solutions to the above issues and problems found in the pilot trials of the first rapid protype.
Figure 3. Concept design sketch for the second rapid prototype
Figure 4. Early version of second prototype installed in Royal Berkshire Hospital, Reading
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4 Production Version of the System The design of this system will be based on results from the clinical trials of the rapid prototypes. If the clinical trials of this system are succesfull, this will lead to a commercial product which will be marketed across Europe, as exploitation is expected in all EC funded projects.
5 Conclusions The design and ergonomics of the two rapid prototype clinical evaluators for this project has been a very challenging and valuable process, which has greatly benefited from the continuous input from users.
6 Acknowledgements The project partners are pleased to acknowledge funding from the European commission quality of life programme framework 5.
7 References Department of Trade and Industry (2000) Older Adultdata, The Handbook of Anthropometric Measurements and Capabilities of the Older Adult: Data for Design Safety (free on request from DTI Publications Order line , ADMAIL 528, London, SWIW 8YT. Tel 0870 1502 500)
