Haptic Assistive Technology for Individuals who are Visually Impaired

NEW, effective methods of non-visual communication are needed for individuals who are blind or visually impaired in the modern world. Areas of relevance include tasks performed in the workplace, in educational settings, in the pursuit of leisure activities, in daily living, and navigating indoor and outdoor spaces. Providing an equivalent of what can be seen through an alternate sensory channel, such as touch or audition, is problematic owing to the intrinsic differences and significantly more limited information transmission capabilities of these alternate perceptual systems. Thus, one of the vexing challenges in developing assistive technologies for individuals who are blind or visually impaired is to provide information that is functionally equivalent to that obtained through visionwithout taxing the other sensory channels. The main focus of this special issue is the use of the tactile/haptic channel in assistive technologies for the blind and visually impaired. A significant advantage of using touch, versus audition, is that it leaves audition free to perform its normal function of listening to environmental sounds, such as cars, people and emergency alerts. The issue begins with an invited paper by Sile O’Modhrain, Nicholas A. Giudice, John A. Gardner, and Gordon E. Legge entitled “Designing Media for VisuallyImpaired Users of Refreshable Touch Displays: Possibilities and Pitfalls.” One of the difficulties in developing assistive technology for individuals who are blind or visually impaired is that many designers have sight. They may, therefore, make incorrect assumptions about the abilities and accommodation strategies of the target population. On the other hand, those who are end users of assistive technology may have difficulty articulating what an appropriate/ desirable substitution mechanism may be. This paper provides insight, particularly with respect to refreshable tactile media, from researchers and developers who have the unique experience of being both designers and users of assistive technology. Pros and cons of several classes of technology are discussed and some commonsense guidelines for assistive technology design are provided. The second paper, “Designing Haptic Assistive Technology for Individuals Who Are Blind or Visually Impaired” by Dianne T.V. Pawluk, Richard J. Adams, and Ryo Kitada, provides a review of several elements relevant to the design of tactile/haptic assistive technology for individuals who are blind or visually impaired. This includes the characteristics of the user population and their involvement in the design process, behavioral and neuroimaging research that is relevant to the design of assistive technology, examples of applying insight from behavioral research to assistive technology design, and assistive technologies that have been developed for some key tasks. The areas of focus are Braille reading, tactile diagrams andmaps, orientation, andmobility. The remaining six papers in this issue are original research papers spanning a wide variety of topics. The first paper considers the importance of user characteristics on the outcome of an assessment of a particular assistive technology. In “The Importance of Visual Experience, Gender, and Emotion in the Assessment of an Assistive Tactile Mouse,” Luca Brayda, Claudio Campus, Mariacarla Memeo, and Laura Lucagrossi consider the complexity of virtual relief maps, a user’s visual experience and a user’s gender on performance defined by mental workload, the amount of information acquired, and the user’s emotional status. In their study, performance appeared to be affected by the gender of a user but not by their previous visual experience. The next paper examines two potentially important tactile cues on user performance reading Braille that have implications for refreshable Braille display design. In “Refreshing Refreshable Braille Displays,” Alexander Russomanno, Sile O’Modhrain, Brent Gillespie, and Matthew Rodger examine the effects of both sliding contact between the finger and Braille “dots” and proprioceptive information from hand movements on a user’s error rate during Braille reading. They also consider the interaction of these effects with Braille reading speed and reading condition. From their results, the authors conclude that sliding motion, but not passive proprioceptive information, improves Braille reading accuracy. The subsequent two papers consider aspects of assistive technology to support independent and safe navigation from one location to another. In “Identification of Vibrotactile Patterns Encoding Obstacle Distance Information,” Yeongmi Kim, Matthias Harders, and Roger Gassert D. Pawluk is with the Biomedical Engineering Department, Virginia Commonwealth University, Richmond, VA 23284. E-mail: [email protected]. N. Bourbakis is with the Center of Assistive Research Technologies (CART) at Wright State University, Dayton, OH 45435. E-mail: [email protected]. N. Giudice is with the School of Computing and Information Science, University of Maine, Orono, ME 04469. E-mail: [email protected]. V. Hayward is with the Institute des Syst emes Intelligents et Robotique, Universit e Pierre et Marie Curie, Paris, France. E-mail: [email protected]. M. Heller is with the Department of Psychology, Eastern Illinois University, Charleston, IL 61920. E-mail: [email protected].