1996 Project Reports

Assistive Technology Projects - Development of Prototypes

James Anderson, JEM; David A. Brown, PhD, PT; Charles G. Burgar, MD; Deane Denney; Arden Farey; Vincent R. Hentz, MD; David L. Jaffe, MS; Deborah Kenney, MS, OTR; Maurice LeBlanc, MS; Stephanie O'Leary, MS, OTR; Eric E. Sabelman, PhD; Alvin Sacks, PhD; Douglas Schwandt, MS; Jaime S. Vargas, MS; Peter Werner, MD; Conal B. Wilmot, MD

Ultrasonic Head Control Interface

Jaffe

The Ultrasonic Head Control Unit is an interface serving people without control of their arms or legs. The user's head position is calculated from ranging data provided by two Polaroid ultrasonic transducers. The head position information is then used for the realtime control of an electric wheelchair or a computer's mouse. Tilts of the user's head off the vertical axis (forward-backward, left-right) operate the wheelchair or move the screen cursor. The primary advantage of this device is that it requires no mechanical contact between the transducers and the user's head. The user, therefore, does not feel "wired up". The interface is intuitive to use, unobtrusive, cosmetically pleasing, and socially acceptable. Within the VA, the Technology Transfer Section in Baltimore has completed a nationwide clinical study of commercial prototype wheelchairs equipped with the interface (from Eureka Labs in Sacramento) and is now funding a cooperative effort with the Cerebral Palsy Research Foundation of Kansas to move this technology to the marketplace.

Ralph Fingerspelling Hand

Jaffe, Schwandt, Anderson

Ralph is a computer controlled electromechanical hand that serves as a tactile display for persons who are deaf and blind. In operation, the deafblind user feels the hand as it moves and interprets its motions as letters corresponding to the American One-Hand Manual Alphabet, a technique known as tactile fingerspelling. The hand is controlled by a microcontroller whose software translates incoming serial ASCII data into control signals that operate eight servo motors. These servo motors pull on the fingers' mechanical linkages causing them to flex. Ralph can use information from a computer's serial port, modem, TDD, or computer interface to a optical character recognition scanner, voice recognition system, closed caption decoder, or stenography machine facilitating translation of e-mail, telephone conversations, printed text, spoken words, subtitled television programs, or classroom/conference/courtroom interactions into fingerspelling. Commercialization of this technology is being pursued through collaborations with an electronics company and a national research laboratory. Figure - Ralph fingerspelling hand

Republished from the 1996 Rehabilitation R&D Center Progress Report.