Tactile Aids for Blindness

Age: Any Age

Sex: Any

Trial Phase: Academic

Sponsor: University of Delaware

Disqualifiers: Amputations, Outer extremity conditions

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: Unknown

100 Participants Needed

Trial Summary

What is the purpose of 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.

Do I need to stop my current medications for the trial?

The trial information does not specify whether you need to stop taking your current medications.

What data supports the effectiveness of the treatment Tactile Aids with Designer Materials, Tactile Aids with Designer Materials, Tactile Coatings for blindness?

Research shows that blind individuals can significantly improve their tactile perception and spatial learning skills using touch-based technologies, such as programmable tactile displays, which enhance their ability to recognize shapes and improve spatial memory. This suggests that tactile aids, like those in the trial, could be effective in enhancing tactile perception and learning in blind individuals. ^{1 2 3 4 5}

Is the Tactile Aids for Blindness treatment safe for humans?

Some materials used in similar devices, like hearing aids, have caused allergic skin reactions in a small number of people. These reactions were linked to specific chemicals in the materials, suggesting that while the treatment may be safe for many, some individuals could experience skin irritation or allergies. ^{6 7 8 9 10}

What makes the Tactile Aids with Designer Materials treatment unique for blindness?

Tactile Aids with Designer Materials is unique because it uses specially designed tactile coatings to enhance touch-based learning and sensory function, offering flexibility and adaptability that traditional methods like raised-line drawings cannot provide. This treatment allows for programmable tactile displays, which can be customized to individual needs, improving spatial learning and shape recognition without requiring constant assistance. ^{1 2 3 11 12}

Eligibility Criteria

This trial is for individuals with low vision or blindness. Participants should be able to perceive tactile sensations and perform tasks that involve identifying objects using touch. There are no specific exclusion criteria provided, but typically participants would not have other conditions affecting their sense of touch.

Inclusion Criteria

Participants should have a basic understanding of mathematical plots, equivalent to at least high school geometry.

I have been blind or visually impaired for over 10 years.

I regularly use devices to help me with touch or feeling.

Exclusion Criteria

I do not have any amputations or conditions that affect my hand use.

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Human Testing

Participants engage in various tasks to evaluate the effectiveness of tactile aids, including fake money counting, GDP plot interpretation, and board game completion.

4 years

Ongoing visits throughout the study

Follow-up

Participants are monitored for feedback on usability and preferences regarding the tactile aids.

4 weeks

Treatment Details

Interventions

• Tactile Aids with Designer Materials

Trial Overview The study is testing new tactile aids designed with special materials to help blind subjects identify objects better than traditional aids like bumps or textures. It measures how accurately and quickly subjects can recognize different items using these new aids.

Participant Groups

Group I: Optimal design of bumps and designer materials in tactile aids Experimental Treatment 3 Interventions

Reflecting the lack of standardized methods or benchmarks for tactile technologies, the known limits of tactile sensitivity was narrowed from millimeters, microns, to nanometers within the last 10 years by use of metal wires, wrinkled plastics, and silanes, respectively. Investigators will determine the optimal design of traditional bumps which yields the highest tactile stimulus in the smallest area. Investigators expect to find that current bumps are larger than necessary, and that the same information could be placed into a smaller area (higher information density). Then, investigators will augment bumps with designer materials to increase the tactile stimulus from a bump, thereby permitting even smaller bumps to increase information density. Beyond optimal design methods, the investigators' quantitative methods, enabled by making the mechanical stimulus the dependent variable, also serve as benchmarks between tactile aids.

Group II: Identifying and synthesizing high-contrast tactile materials without physical features Experimental Treatment 3 Interventions

Beyond the few materials investigators previously identified, it is unknown which materials are useful for creating tactile sensations. Common material properties such as a friction coefficient or hydrophilicity are insufficiently detailed to accurately predict friction forces-the basis of tactile stimuli. The investigators will use expertise in connecting tactile sensations with chemical structure through mechanical testing, theory, and human testing. The investigators' goal is to identify materials that lead to high tactile contrast without relying on physical features. (Tactile contrast is defined by the investigators as large differences in friction which are easily distinguishable by humans during free tactile exploration.)

Group III: Building tactile aids with designer materials for plots, games, and object labeling Experimental Treatment 3 Interventions

Investigators will build static tactile aids with designer materials, i.e., silanes and polymers coatings. These aids will be a mathematical plot, a board game, and simulated money. Investigators will compare the speed, accuracy, and amount of information of hybrid tactile aids made from designer materials and physical features to traditional tactile aids made only with bumps.

Who Is Running the Clinical Trial?

University of Delaware

Lead Sponsor

Trials

167

Recruited

25,700+

Findings from Research

Blind Braille readers initially showed superior performance compared to sighted individuals in a hyperacuity task involving Braille-like dot patterns, but both groups reached similar levels of performance with practice.

In other tactile tasks, such as discriminating ridge width and grating orientation, there was no significant difference in performance between blind and sighted participants, suggesting that the advantages of the blind may be specific to their experience with Braille.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Tactile perception in blind Braille readers: a psychophysical study of acuity and hyperacuity using gratings and dot patterns. Grant, AC., Thiagarajah, MC., Sathian, K.[2019]

Programmable tactile displays significantly enhance spatial memory and shape recognition skills in blind and low vision children, showing improvement over a four-week testing period with minimal external assistance required.

These programmable maps are as effective as traditional raised-line drawings for education and rehabilitation, offering greater flexibility and adaptability for teaching graphical content.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

The Effect of Programmable Tactile Displays on Spatial Learning Skills in Children and Adolescents of Different Visual Disability. Leo, F., Cocchi, E., Brayda, L.[2022]

In a study involving younger and older sighted participants, it was found that tactile bars are more easily distinguished from tactile dots when there is a greater difference in their length and width, highlighting the importance of size variation for effective use by visually impaired individuals.

Additionally, tactile dots with a larger edge radius of curvature were more easily discriminated than those with a smaller radius, suggesting that the design of tactile features can significantly enhance usability for people with visual impairments.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Influences of the edge radius of curvature of tactile dots and bars on their discriminability. Toyoda, W., Doi, K., Fujimoto, H.[2019]

Blind individuals often struggle with awareness of their limb position, making it difficult to use handheld electronic travel aids effectively.

Training with auditory feedback to maintain the correct orientation of these aids significantly improves hazard detection, and the benefits of this training persist even after the feedback is removed.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

An application of bio-feedback in the rehabilitation of the blind. Bissitt, D., Heyes, AD.[2019]

A study involving 250 students from blind schools in Delhi found that while awareness of tactile and sound-based assistive technologies was high (e.g., 98% for Braille books), the utilization of visual-based technologies was very low, especially among those with severe visual impairments.

Despite the high awareness of various assistive devices, the actual use of technologies like screen readers and math/science learning tools was poor, indicating a need for better training and encouragement for students to use available technologies that could enhance their academic performance.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Assistive technology for students with visual disability in schools for the blind in Delhi. Senjam, SS., Foster, A., Bascaran, C., et al.[2021]

A 65-year-old woman developed dermatitis in her ear canal after using hearing aids, which was linked to allergic reactions to materials in the hearing aid shell, specifically certain acrylics.

The dermatitis improved after she stopped using the hearing aids, and it was recommended that she switch to a hearing device with a silicone earpiece worn behind the ear to avoid further irritation.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Allergic contact dermatitis from hearing aid materials. Sood, A., Taylor, JS.[2019]

In a study of 22 hearing aid users with severe ear canal dermatitis, 27% tested positive for contact allergies to earmold materials, particularly methyl methacrylate.

The findings suggest that routine patch testing should be implemented for these patients to identify potential allergens and improve their treatment outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Allergic contact dermatitis from the earmolds of hearing aids. Meding, B., Ringdahl, A.[2019]

Polymeric polyisocyanate prepolymers are significantly less potent as skin sensitizers compared to their diisocyanate monomer counterparts, showing at least 300 times lower sensitization potency based on the mouse Local Lymph Node Assay (LLNA).

The sensitization potential of these prepolymers is primarily influenced by their hydrophobicity and surfactant properties, suggesting that not all isocyanate-containing substances pose the same health risks, which can inform safer development of polyurethane materials.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Exploring structure/property relationships to health and environmental hazards of polymeric polyisocyanate prepolymer substances-2. Dermal sensitization potential in the mouse local lymph node assay. West, RJ., Burleson, S., Gulledge, T., et al.[2022]

Dermal absorption of MDI and TDI is very low, at or below 1% of the applied dose, indicating minimal systemic exposure and toxicity after skin contact.

However, both MDI and TDI can cause skin irritation, with unchanged chemical remaining on the skin for up to 8 hours, suggesting the need for careful handling to prevent skin damage.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dermal uptake and excretion of 14C-toluene diisocyante (TDI) and 14C-methylene diphenyl diisocyanate (MDI) in male rats. Clinical signs and histopathology following dermal exposure of male rats to TDI. Hoffmann, HD., Leibold, E., Ehnes, C., et al.[2018]

Workers in the semiconductor industry are exposed to strong skin irritants and allergens, particularly during cleaning, repair, and maintenance tasks, which pose significant risks despite advancements in equipment safety.

The article highlights the specific cutaneous hazards associated with each step of microchip production, emphasizing the need for targeted safety measures for at-risk workers.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Dermatitis in the microelectronics industry. Adams, RM.[2004]

A new method using a 3 x 3 braille dot cell was developed to assess fine sensory function in both blind and sighted individuals, showing high reliability (r = 0.95) in braille pattern identification.

The study found that braille pattern identification correlates strongly with two-point discrimination, suggesting it is an effective measure for evaluating higher levels of hand sensibility in blind individuals.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Development of a new measure of fine sensory function. Novak, CB., Mackinnon, SE., Williams, JI., et al.[2019]

The paper presents a new, cost-effective light sensor designed to assist blind individuals, addressing the limitations of existing sensory aids that are often expensive and require extensive training.

The development includes detailed construction notes and parts requirements, making it accessible for rehabilitation training and personal use, potentially enhancing independence for users.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

A light probe adapted for use in training the blind. Schaefer, KJ., Specht, TR.[2012]

References

1. United States pubmed.ncbi.nlm.nih.gov

Tactile perception in blind Braille readers: a psychophysical study of acuity and hyperacuity using gratings and dot patterns. [2019]

2. United States pubmed.ncbi.nlm.nih.gov

The Effect of Programmable Tactile Displays on Spatial Learning Skills in Children and Adolescents of Different Visual Disability. [2022]

3. Netherlands pubmed.ncbi.nlm.nih.gov

Influences of the edge radius of curvature of tactile dots and bars on their discriminability. [2019]

4. England pubmed.ncbi.nlm.nih.gov

An application of bio-feedback in the rehabilitation of the blind. [2019]

5. England pubmed.ncbi.nlm.nih.gov

Assistive technology for students with visual disability in schools for the blind in Delhi. [2021]

6. United States pubmed.ncbi.nlm.nih.gov

Allergic contact dermatitis from hearing aid materials. [2019]

7. United States pubmed.ncbi.nlm.nih.gov

Allergic contact dermatitis from the earmolds of hearing aids. [2019]

8. England pubmed.ncbi.nlm.nih.gov

Exploring structure/property relationships to health and environmental hazards of polymeric polyisocyanate prepolymer substances-2. Dermal sensitization potential in the mouse local lymph node assay. [2022]

9. Netherlands pubmed.ncbi.nlm.nih.gov

Dermal uptake and excretion of 14C-toluene diisocyante (TDI) and 14C-methylene diphenyl diisocyanate (MDI) in male rats. Clinical signs and histopathology following dermal exposure of male rats to TDI. [2018]

10. United States pubmed.ncbi.nlm.nih.gov

Dermatitis in the microelectronics industry. [2004]

11. United States pubmed.ncbi.nlm.nih.gov

Development of a new measure of fine sensory function. [2019]

12. United States pubmed.ncbi.nlm.nih.gov

A light probe adapted for use in training the blind. [2012]