A RETROSPECTIVE STUDY OF THE USE AND ABANDONMENT OF ASSISTIVE DEVICES DEVELOPED BY STUDENT DESIGN PROJECTS

Allen H. Hoffman and Holly K. Ault Mechanical Engineering Department Worcester Polytechnic Institute Worcester, MA 01609-2280

ABSTRACT

Our institution requires that all students complete a major design project. Working in groups of 2-4 during the senior year, the students usually devote approximately one third of their time to the project. Over the past 6 years, these projects have produced 15 assistive devices which were then used by either children or young adults. A survey of the use and abandonment of these devices showed that student designed devices exhibit similar reasons for abandonment when compared to devices obtained through other means. In addition, the study revealed a need for follow up testing and design modifications after the student design team has left, particularly with more complex devices.

BACKGROUND

At our institution, student design projects that develop assistive devices have two primary goals: providing a capstone design experience for senior engineering students and providing customized assistive devices to disabled users. The educational objectives and operation of the program have been described in detail elsewhere (1). Briefly, all students are required to complete a major design project. The project is usually selected at the end of the junior year and begun in the senior year. Working in groups of 2-4, the students devote approximately one third of their time during the nine month academic year to the project. Thus each project represents the result of up to one person year of effort. Since 1989, we have used these projects to design and develop devices to assist disabled individuals. A project is not considered successful unless a working device is conveyed to a specific individual (client). The costs of materials and components used to produce the devices were supported by grants. The clients received the devices at no cost. Assistive devices developed by students represent a microcosm of the overall assistive device delivery system. Abandonment of assistive devices has been identified as a major problem in the delivery of services to the disabled and represents an inefficient use of resources. Factors that have been linked to device abandonment are: lack of user involvement in selection, easy device procurement, poor device performance and changing user needs (2). Developing custom assistive devices through student design projects mutually benefits the students and the clients (1). We were interested in determining whether there were unique issues associated with the use of student developed devices and whether the pattern of abandonment of these devices differed substantially from that reported in the literature.

OBJECTIVE

The goal of this study was to monitor the use and abandonment of assistive devices produced by major student design projects over an extended period of time. This would allow us to identify problems with past designs that could be used to improve the delivery of student developed assistive technology. In addition, detailed case studies developed from this study can be used in educating students on factors affecting assistive device usage.

METHODS

A survey was conducted in November 1995 to establish the status of all assistive devices developed through student design projects over the past six years. A standard data sheet was used to gather information about each device. Data were gathered concerning the current status and the length of time frame the device had been used. If the device was not currently being used, the reasons for that status were noted and a determination of the modifications or repairs necessary to return the device to use was made. Since all but one of the devices were developed through collaboration with a single residential rehabilitation facility, it was relatively easy to obtain detailed information regarding the use of each device. Many devices were still located at the facility. In cases where the clients had left the facility and taken their devices with them, staff at the facility were still aware of the device status.

RESULTS

During the past 6 years, 15 projects involving 46 students have yielded working prototypes (Table I).

Table I. ASSISTIVE DEVICE PROJECTS

Three of the devices (20%) have seen continuous service and are presently in use. The universal arm which is used for holding cameras and similar items and the wheelchair roller exerciser have not needed any repair. The swingaway laptray initially required some minor modifications, but has since functioned reliably for over 3 years. Four additional devices (27%), not presently in use, fulfilled their original purpose for more than one year. In each case, a change in user conditions or needs resulted in the use being discontinued. The therapeutic tricycle was outgrown; the client for the art class assistor graduated from school. The user of the mobile bow mount has a new chair, requiring modification of the device. The quick release pushcart was designed for transporting dishes in the user's residential setting. The original user lost interest in performing this task, and the device was modified for an alternative use. It is now awaiting use by a new client. Each of these devices could be modified to allow for continued use with either the same or a new client. These modifications would need to be performed by the staff of the rehabilitation facility. The reacher/gripper, a motorized robotic arm, was initially successful and extensively used. However, it proved to be a high maintenance device. Major mod- ifications were undertaken but not completed. Three early devices (20%) were abandoned within 6 months due to a combination of poor performance and a lack of client/staff/caregiver acceptance. In addition, three recent devices (20%), the secondary joystick, the bowling machine and the shock absorbing footrest, are not presently being used due to problems associated with insufficient testing during development and a lack of adequate client/staff training. These devices experienced almost immediate mechanical problems when placed in use as well as some lack of acceptance by client/staff. The shock absorbing footrest also exhibited poor performance, in part due to lack of time for design modification by the student designers. One device, the lightweight wheelchair, met all of the original design and client expectations but was lost to follow-up when the client moved.

DISCUSSION

Most factors affecting the use and abandonment of student designed assistive devices parallel those pub- lished for assistive technology devices as a whole (2). We deal with a young client population (ages 3-20) who are primarily in a residential setting. In this age group, it is to be expected that changing client needs, often associated with growth and maturity, will lead to discontinued use of many devices. Four of our devices were used for over 1 year before being discontinued. These devices met their original intended use and are considered to have been successful. Thus 47% (7/15) of the devices were successfully used. Three early devices (20%) were abandoned within 6 months. The lack of success in these early devices is mostly attributable to our initial lack of experience in the assistive technology area. In executing these designs we failed to give appropriate attention to the user interface and to continued involvement of the client/staff/caregiver in the design process. However, four well designed devices seem to suffer from problems specifically related to using students to design and build relatively complex assistive devices. Completion of the project is a requirement for gradua- tion. If problems are encountered in executing the project, the time originally allocated for testing and evaluation generally shrinks sometimes to as little as 1-2 weeks. This has proven to be inadequate for several of the devices. The reacher/gripper functioned well for about 3 months, then it became apparent that some of the components were not durable enough for continued use. Major repairs were initiated by the rehabilitation facility but never completed. The secondary joystick worked but not well enough to suit the client. It appears that several iterations of minor modifications will be needed before the device is acceptable to the client. The rehabilitation facility has difficulty budgeting time for these activities. The bowling machine required substan- tial redesign by other students. The shock absorbing footrest also needs design modifications. In particular, the more sophisticated or complex electromechanical devices are more readily abandoned due to issues related to insufficient testing, maintenance or training of staff. Within the limits of one academic year, student projects rarely proceed beyond a second design iteration. Several of these devices need a third or fourth design iteration, often to address issues associated with long term service. To improve the success rate of complex student designed assistive technology, academic insti- tutions can chose only to work with rehabilitation institutions that can take on device repair and accom- plish the additional design iterations or be prepared to take on these functions themselves using laboratory assistants. We are experimenting with the latter approach. To increase device utility, we now retrieve devices that need repairs that can not be readily accomplished at the rehabilitation facility. In addition we plan to modify some devices which no longer meet the needs of the original clients due to growth, changes in ability etc. so that they can be used by others. By experimenting with these approaches we hope to increase the utility and effectiveness of student designed and developed assistive technology.

REFERENCES

1. Ault, H.K. and A.H. Hoffman, "Teaching Design through the Development of Devices to Assist the Disabled" in Innovations in Engineering Design Edu- cation Resource Guide, ASME, New York, pp. 241-244, 1993.

2. Phillips, B. and H. Zhao, "Predictors of Assistive Technology Abandonment", Assistive Technology 5:36-45, 1993.

ACKNOWLEDGMENTS

A portion of this work was funded by NSF BRAD Grants #BCS-8907759 and #BES-9410510. The cooperation of the Massachusetts Hospital School and the Alfred I. duPont Institute are gratefully acknowledged. Allen H. Hoffman Mechanical Engineering Department Worcester Polytechnic Institute Worcester, MA 01609-2280 Phone: (508) 831-5217 Fax: (508) 831-5680 e-mail ahoffman@wpi.edu