Design and Validation of the Readable Device: A Single-Cell Electromagnetic Refreshable Braille Display

Mediated and non-mediated tactile fingerspelling: a comparative study

In the development of communication devices for individuals who are Deafblind, a significant challenge is achieving a seamless transition from human-generated to technology-mediated communication. This study compares the intelligibility of the Australian Deafblind tactile fingerspelling alphabet rendered on the HaptiComm tactile communication device with the same alphabet articulated by a human signer. After a short training period, participants identified the 26 English alphabet letters in both the mediated (device) and non-mediated (human) conditions. Results indicated that while participants easily identified most letters in the non-mediated condition, the mediated condition was more difficult to decipher. Specifically, letters presented on the palm or near the index finger had significantly lower recognition rates. These findings highlight the need for further research on the tactile features of communication devices and emphasize the importance of refining these features to enhance the reliability and readability of mediated tactile communication produced through tactile fingerspelling.

Biomechanical Considerations of Refreshable Braille and Tactile Graphics Toward Equitable Access: A Review

This review highlights the biomechanical foundations of braille and tactile graphic discrimination within the context of design innovations in information access for the blind and low-vision community. Braille discrimination is a complex and poorly understood process that necessitates the coordination of motor control, mechanotransduction, and cognitive-linguistic processing. Despite substantial technological advances and multiple design attempts over the last fifty years, a low-cost, high-fidelity refreshable braille and tactile graphics display has yet to be delivered. Consequently, the blind and low-vision communities are left with limited options for information access. This is amplified by the rapid adoption of graphical user interfaces for human-computer interaction, a move that the blind and low vision community were effectively excluded from. Text-to-speech screen readers lack the ability to convey the nuances necessary for science, technology, engineering, arts, and math education and offer limited privacy for the user. Printed braille and tactile graphics are effective modalities but are time and resource-intensive, difficult to access, and lack real-time rendering. Single- and multiline refreshable braille devices either lack functionality or are extremely cost-prohibitive. Early computational models of mechanotransduction through complex digital skin tissue and the kinematics of the braille reading finger are explored as insight into device design specifications. A use-centered, convergence approach for future designs is discussed in which the design space is defined by both the end-user requirements and the available technology.

Fly-LeNet: A deep learning-based framework for converting multilingual braille images

For many years, braille-assistive technologies have aided blind individuals in reading, writing, learning, and communicating with sighted individuals. These technologies have been instrumental in promoting inclusivity and breaking down communication barriers in the lives of blind people. One of these technologies is the Optical Braille Recognition (OBR) system, which facilitates communication between sighted and blind individuals. However, current OBR systems have a gap in their ability to convert braille documents into multilingual texts, making it challenging for sighted individuals to learn braille for self-learning-based uses. To address this gap, we recommend a segmentation and deep learning-based approach named Fly-LeNet that converts braille images into multilingual texts. The approach includes image acquisition, preprocessing, and segmentation using the Mayfly optimization approach with a thresholding method and a braille multilingual mapping step. It uses a deep learning model, LeNet-5, that recognizes braille cells. We evaluated the performance of the Fly-LeNet through several experiments on two datasets of braille images. Dataset-1 consists of 1404 labeled samples of 27 braille signs demonstrating the alphabet letters, while Dataset-2 comprises 5420 labeled samples of 37 braille symbols representing alphabets, numbers, and punctuations, among which we used 2000 samples for cross-validation. The suggested model achieved a high classification accuracy of 99.77% and 99.80% on the test sets of the first and second datasets, respectively. The results demonstrate the potential of Fly-LeNet for multilingual braille transformation, enabling effective communication with sighted individuals.

Novel Refreshable Braille Display Based on the Layered Electromagnetic Driving Mechanism of Braille Dots

In the digital era, Braille displays enable visually impaired people to easily access information. Different from traditional piezoelectric Braille displays, a novel electromagnetic Braille display is realized in this study. The novel display has the advantages of a stable performance, a long service life and a low cost and is based on an innovative layered electromagnetic driving mechanism of Braille dots, which can achieve a dense arrangement of Braille dots and provide a sufficient support force for them. The T-shaped screw compression spring, which causes the Braille dots to fall back instantaneously, is optimized to achieve a high refresh frequency and to enable visually impaired people to read Braille quickly. The experimental results show that under an input voltage of 6 V, the Braille display can work stably and reliably and provide a good fingertip touch; the Braille dot support force is greater than 150 mN, the maximum refresh frequency can reach 50 Hz, and the operating temperature is lower than 32 °C. Therefore, this cost-effective Braille display is expected to benefit a vast number of low-income visually impaired people in developing countries and improve their learning, working and living conditions.

Engineering Liquid-Vapor Phase Transition for Refreshable Haptic Interfaces

Haptics as a communication medium has been increasingly emphasized across various disciplines. Recent efforts have focused on developing various haptic stimulation technologies; however, most of them suffer from critical drawbacks stemming from their bulk, complexity, large power input, or high cost. Here, we describe a strategy to design portable and affordable refreshable haptic interfaces composed of an array of individually addressable and controllable liquid pouch motor-based haptic units embedded in either rigid or flexible substrates for different application contexts. The pouch motor filled with low boiling fluid, under a controlled manner, expands or contracts by Joule heating or cooling, enabling the haptic pin in contact to be protruded or retracted. Programming the actuation sequence of an array of haptic units enables the haptic interface to apply different stimuli to the skin to convey corresponding information. We finally demonstrate the applications to portable rigid braille displays and flexible epidermal VR devices. This study opens the avenue to the design of ubiquitous refreshable haptic interfaces that is portable, affordable, scalable, and uninjurious.

Refreshable Braille Display With Adjustable Cell Size for Learners With Different Tactile Sensitivity

Braille is one of the most popular mediums of education for the blind. However, learning braille requires trainers and a lot of practice. Additionally, different individuals have different levels of tactile sensitivity at their fingertips. The tactile components get often overlooked in most braille learning devices and related studies. Our solution is a single cell refreshable braille display with six custom-made electromechanical flapper actuators. It incorporates speech functionalities to facilitate self-learning and independent operation. The cell size can be adjusted according to the learner's preference by moving the actuators. The device can provide standard braille cell dimensions and elevation as well. It is designed to help learners with different tactile perceptions improve themselves through practice and adapt to standard size braille. The operational conditions and force analysis of the braille dots were performed. Two tests were also performed with two different cell sizes to evaluate the device with several blind students. The device is very affordable and easy to maintain. It can also be used to teach braille to the sighted.

A Survey on Tactile Displays For Visually Impaired People

Traditional paper documents with Braille characters and tangible graphics have obvious defects to disseminate knowledge in the information age. Information accessibility is an urgent challenge for blind individuals. Although many types of tactile displays were created for different applications, we especially focus on the tactile display for visually impaired people, which can dynamically generate tangible graphics and Braille characters, to help the blind obtain information conveniently. In this article, we present the state-of-the-art of graphic tactile displays (GTDs) and refreshable Braille displays (RBDs), then discuss their common kernel technologies about actuators and latch structures. This article summarizes the performance of typical actuators of tactile displays and analyzes the working principles of some latch structures. This article systematically summarizes latch structures of GTDs and RBDs, for the first time. Several comments in this paper will be useful to develop high-performance tactile displays for visually impaired people.