Testing Tactile Aids With Blind Subjects
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age16+
SponsorUniversity of Delaware
About this trial
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.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
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.
Disqualifiers
None
Trial design
Design model
Sequential
Treatments tested in this trial
Single bump acuity
BehavioralInvestigators 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
Optimal spacing between bumps
BehavioralInvestigators 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.
Improving signal from a single bump with designer materials
BehavioralInvestigators 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").
Treatment groups
100 Participants
are divided into 3 treatment groupsGroup A: Identifying and synthesizing high-contrast tactile materials without physical featuresExperimental treatment 3 interventions
Group B: Building tactile aids with designer materials for plots, games, and object labelingExperimental treatment 3 interventions
Group C: Optimal design of bumps and designer materials in tactile aidsExperimental treatment 3 interventions
Trial outcomes
Primary outcomes
1
Success rate for correctly interpreting a tactile numeric plot of the GDP (Gross Domestic Product) of four countries.
Researchers will create a tactile plot of the GDP of four countries on an xy plot. The different countries are denoted from a combination of traditional lines or bump-dashed lines, and from a line made with a tactile coating. At three positions along the x-axis of on the plot, the relative GDP of which country has the most will change. Participants will be asked to give which country is the highest GDP and the lowest at these three positions. The primary outcome measure is if when asked, what is the GDP of country X at a certain value, participants successfully provide the correct value. More specifically, the percent of answer correct for each given country. Four countries will be used, with three being denoted through physical features, and the fourth denoted with a tactile coating.
Time frame
Immediately after human testing (middle of year 2)2
Usability of GDP plot tactile aid.
Researchers will create a tactile plot of the GDP of four countries on an xy plot. The different countries are denoted from a combination of traditional lines or bump-dashed lines, and from a line made with a tactile coating. At three positions along the x-axis of on the plot, the relative GDP of which country has the most will change. Participants will be asked to give which country is the highest GDP and the lowest at these three positions. Secondary outcome measures are usability of the tactile aid on a Likert scale, its comfort, how easy the tactile coating was to distinguish versus the physical features, and a free response of feedback on usability. Title: GDP Plot Usability Min: 0 Max: 6 Higher the score, the better the outcome/ usability of the tactile plot.
Time frame
Immediately after human testing (middle of year 2)3
Time to completion of a tactile board game.
For participants who were successful at the Outcome 1 Task, they will be asked to play a tactile board game that resembles "chutes and ladders". They will play one of two versions, with the first version being randomized across participants. In one version, the chutes and ladders are made from traditional physical features. In the second version, the chutes and ladder each have tactile coatings in addition to their physical features. Participants will be given a preselected list of spaces to move which normalizes the path length between the board made with only physical features versus the board made with physical features and tactile coatings. Participants will be timed on how quickly they finish the board game and the time to completion between the two different boards will be compared.
Time frame
Immediately after human testing with this tactile aid (end of year 3)4
Success rate to completion for a fake money counting task.
Participants will be given a random collection of 3-5 fake bills with the denominations on the bills each represented by a different tactile coating. After familiarization and training, participants will be given the random collection of 3-5 fake bills and asked to give a sum of the bills in their hand. Participants will be evaluated on whether or not their response is correct. This will be repeated 15 times.
Time frame
Immediately after human testing with this tactile aid (end of year 4)Sponsors and contacts
Click on the lead sponsor to view all of their trials.
Source ClinicalTrials.gov