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NCT Number: NCT06237829

Testing Tactile Aids With Blind Subjects

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.

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Key information

Conditions

Vision, Low Blindness Eye Diseases Nervous System Diseases Neurologic Manifestations Pathological Conditions, Signs and Symptoms Sensation Disorders Signs and Symptoms Vision Disorders

Age range

16 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

About this study

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 details on a single tactile aid quickly becomes illegible to the user because the various bumps, lines, and textures blur together, which is known as "tactile clutter".

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 include having low vision or blind subjects identify objects made from our tactile materials quicker than traditional tactile aids, or to successfully identify more categories on a mathematical plot than is currently possible with existing tactile aids.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

Single bump acuity

Behavioral

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

Optimal spacing between bumps

Behavioral

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.

Improving signal from a single bump with designer materials

Behavioral

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").

Primary outcomes

  1. Success rate for correctly interpreting a tactile numeric plot of the GDP (Gross Domestic Product) of four countries.

    Time frame: Immediately after human testing (middle of year 2)

    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.

  2. Usability of GDP plot tactile aid.

    Time frame: Immediately after human testing (middle of year 2)

    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.

  3. Time to completion of a tactile board game.

    Time frame: Immediately after human testing with this tactile aid (end of year 3)

    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.

  4. Success rate to completion for a fake money counting task.

    Time frame: Immediately after human testing with this tactile aid (end of year 4)

    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.

  5. Success time to completion for a fake money counting task.

    Time frame: Immediately after human testing with this tactile aid (end of year 4)

    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 how quickly they completed the task. This will be repeated 15 times.

  6. Usability and general feedback

    Time frame: Through study completion, 4 years.

    Subjects participating in the clinical trial will be invited to provide feedback on the usability and their preferences regarding the tactile aid introduced in the study. The assessment will be conducted using a modified Likert scale. This outcome aims to gather subjective experiences related to the use of new tactile aids throughout the trials. Throughout the study, participants will be consistently asked to comment on the usability and their preferences based on the tactile aid. This ongoing feedback will enable a comprehensive understanding of their experiences over time.

    Modified Likert Scale:

    Strongly Disagree Disagree Somewhat Disagree Neutral Somewhat Agree Agree Strongly Agree Extremely Agree Exceptionally Agree

    Title: Usability of Tactile Aid Min: 1 Max: 9 Higher the score, the better the outcome/ usability of the tactile aid.

Sponsors and collaborators

Lead sponsor

University of Delaware

Other

Registry information

Important dates

Study start
2021
Primary completion
2026
Study completion
2027
First posted
Feb 2, 2024
Registry last updated
Mar 13, 2024

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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