Testing Tactile Aids With Blind Subjects
University of Delaware
Summary
The objective of this project is to create richer tactile aids by using materials chemistry to create tactile sensations in tactile aids, as an alternative to traditional physical bumps, lines, or textures. These materials are commonly used in household products, but have not yet been used to enrich tactile aids. Successful outcomes are primarily the accuracy with which low vision or blind subjects identify objects made from tactile coatings versus traditional tactile aids. Other outcomes include time to completion of the task, or the number of distinctive categories that participants can identify.
Description
Traditional images and graphics, like mathematical plots or charts, are not accessible to low vision and blind people. Instead, for blind and low vision people, tactile aids are traditionally used to convey abstract concepts. However, tactile aids cannot convey as rich or as dense of information as traditional visual graphics, limiting independence and access to gainful employment for low vision and blind professionals. The primary reason why tactile aids are inferior to visual graphics is that tactile aids are made from a combination of physical bumps, lines, and labels. Placing too many det…
Eligibility
- Age range
- 16+ years
- Sex
- All
- Healthy volunteers
- Yes
Inclusion Criteria: * Visual Impairment: Participants should be blind or visually impaired for greater than 10 years, either congenitally or acquired. * Tactile Aid Usage: Participants must use tactile aids regularly. * Mathematical Knowledge: Participants should have a basic understanding of mathematical plots, equivalent to at least high school geometry. Exclusion Criteria: \- Limb Conditions: Participants with amputations or outer extremity conditions affecting hand use will be excluded.
Interventions
- BehavioralSingle bump acuity
Investigators will design bumps of varying heights, spacings, diameters, and bump shapes (rounded top, flat top, angled top) which give a precise amount of mechanical stimulus to the finger. Subjects will be asked if they could notice a bump on the surface and instructed to make the judgment quickly (\<2 seconds). A psychometric curve, with a standard braille bump serving as the positive, \~100% success rate control, will be constructed
- BehavioralOptimal spacing between bumps
Investigators will fabricate and characterize two bumps of varying widths (ranging from 150 μm to 3 times the bump width, based on fabrication resolution available in commercial tactile aid machines). Subjects will be asked to run their finger across the two bumps (two bumps always form a line, so investigators do not need to ask subjects to orient their fingers) quickly and asked if they felt one bump or two.
- BehavioralImproving signal from a single bump with designer materials
Investigators will coat single bumps with our designer materials (with alkyl and amino functional groups) to improve the mechanical stimuli from a single bump. Subjects will then be asked to perform a similar experiment as the "single bump acuity" test and the "optimal spacing between bumps" test. ("can you notice the bump?" or "did you feel one or two bumps").
Location
- University of DelawareNewark, Delaware