Enabling visually disabled persons to create technical drawings: a review with a preliminary contribution

This white paper is dedicated to creating geometrical content by visually impaired persons, aiming to increase the effectiveness of several existing tools and solutions. It starts with an updated analysis of the state of the art regarding their use as an aid in accessing and designing of those contents. We observed that, besides being only a few, the existing solutions fail in one or more of the following requirements: continuous tactile feedback, error correction tools, compatibility with the most common assistive technologies and the possibility of sharing the created image, thus not allowing a sufficiently effective use. Inspired by our previous work in accessibility to mathematics and vectorised graphics by blind persons and in the multimodal human-computer interface paradigm, we created and are now presenting a preliminary contribution to improving the situation for the specific case of the creation of technical drawings. The proposed solution is based on an iterative and flexible interface with a navigation method that considers the management of the user's cognitive load during the creation process, using some Gestalt principles, the primary interface modalities, and continuous feedback on what is being created. The implementation is currently underway using web technologies to interconnect the interface devices, allowing the user to create standard geometric shapes by combining inputs through a command line, a voice interface, and a drawing pad. Continuous tactile feedback is provided through braille, a general-purpose tactile graphic display, and acoustic feedback through text-to-speech. An embossing printer and audio sonification will also be used. After the development of the application, tests with users will follow to improve and validate the proposed solution.