Early clinical evaluation of a robot arm/worktable system for spinal-cord-injured persons.

In Part I, "Developmental Case Study", this evaluation traces anecdotally the increasing application of microcomputer technology in a research program examining the uses of a robot arm in the rehabilitation of the high-spinal-cord-injured person. This program, supported by the Veterans Administration since 1974, built upon still earlier VA-supported work at Johns Hopkins on powered upper-limb prostheses. The Johns Hopkins University powered shoulder prosthesis served as the basis for the Robotic Arm/Worktable System, whose evolution is described in applications ranging from handling simple reading materials to self-feeding and the operation of a personal computer, all under the user's control through the same chin control interface employed for the control of the user's power wheelchair. Part II of this report focuses on the results of clinical evaluation in the development of the system. In the early stages of development, evaluation was provided by four subjects who used the system regularly for periods ranging from 4 months to a year. A later stage of evaluation featured a total of 16 subjects located in two VA Medical Centers, using the system for periods of from a few days to 4 months in duration. The VA's new Rehab R&D Evaluation Unit has begun an intensive evaluation process based upon 25 of the Robotic Arm/Worktable Systems currently on order.

A new communications technique for the nonvocal person, using the Apple II Computer.

The purpose of this paper is to describe a technique for nonvocal personal communication for the severely handicapped person, using the Apple II computer system and standard commercially available software diskettes (Visi-Calc). The user's input in a pseudo-Morse code is generated via minute chin motions or limited finger motions applied to a suitable configured two-switch device, and input via the JHU/APL Morse code interface card. The commands and features of the program's row-column matrix, originally intended and widely used for financial management, are used here to call up and modify a large array of stored sentences which can be useful in personal communication. It is not known at this time if the system is in fact cost-effective for the sole purpose of nonvocal communication, since system tradeoff studies have not been made relative to other techniques. However, in some instances an Apple computer may be already available for other purposes at the institution or in the home, and the system described could simply be another utilization of that personal computer. In any case, the system clearly does not meet the requirement of portability. No special components (except for the JHU/APL Morse interface card) and no special programming experience are required to duplicate the communications technique described.

An assistive equipment controller for quadriplegics.

A joystick is traditionally used to manipulate electrically powered wheelchairs and radio-controlled model aeroplanes. Extensive modifications of the joystick have resulted in the development of an inconspicuous chin-operated control; the latter enables quadriplegics with high-level spinal cord injuries to operate not only electric wheelchairs but also a complete range of other assistive devices, including robotic arm and environmental control systems currently under development. Through the use of the chin-operated control such quadriplegics can manipulate any of these devices or systems without the help of an attendant and without interfering with the use of a mouthstick.