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


Vision loss has severe impacts on physical, social and emotional well-being. The education of blind children poses issues as many scholar disciplines (e.g. geometry, mathematics) are normally taught by heavily relying on vision. Touch-based assistive technologies are potential tools to provide graphical contents to blind users, improving learning possibilities and social inclusion. Raised-lines drawings are still the golden standard, but stimuli cannot be reconfigured or adapted and the blind person constantly requires assistance. Although much research concerns technological development, little work concerned the assessment of programmable tactile graphics, in educative and rehabilitative contexts. Here we designed, on programmable tactile displays, tests aimed at assessing spatial memory skills and shapes recognition abilities. Tests involved a group of blind and a group of low vision children and adolescents in a four-week longitudinal schedule. After establishing subject-specific difficulty levels, we observed a significant enhancement of performance across sessions and for both groups. Learning effects were comparable to raised paper control tests: however, our setup required minimal external assistance. Overall, our results demonstrate that programmable maps are an effective way to display graphical contents in educative/rehabilitative contexts. They can be at least as effective as traditional paper tests yet providing superior flexibility and versatility.
Fabrizio Leo
Published in: IEEE Transactions on Neural Systems and Rehabilitation Engineering ( Volume: PP, Issue: 99 )
DOI: 10.1109/TNSRE.2016.2619742

Using pot-magnets to enable stable and scalable electromagnetic tactile displays


We present the design, fabrication, characterization and psychophysical testing of a scalable haptic display based on electromagnetic (EM) actuators. The display consists of a 4×4 array of taxels, each of which can be in a raised or a lowered position, thus generating different static configurations. One of the most challenging aspects when designing densely-packed arrays of EM actuators is obtaining large actuation forces while simultaneously generating only weak interactions between neighboring taxels. In this work we introduce a lightweight and effective magnetic shielding architecture. The moving part of each taxel is a cylindrical permanent magnet embedded in a ferromagnetic pot, forming a pot-magnet. An array of planar microcoils attracts or repels each pot-magnet. This configuration reduces the interaction between neighboring magnets by more than one order of magnitude, while the coil/magnet interaction is only reduced by 10%. For 4 mm diameter pins on an 8 mm pitch, we obtained displacements of 0.55 mm and forces of 40 mN using 1.7 W. We measured the accuracy of human perception under two actuation configurations which differed in the force vs. displacement curve. We obtained 91% of correct answers in pulling configuration and 100% in pushing configuration.
Published in: IEEE Transactions on Haptics ( Volume: PP, Issue: 99 )
DOI: 10.1109/TOH.2016.2591951

IEEE Haptics Symposium 2016

Nadine Besse, Herbert Shea, Juan Zarate, Samuel Rosset, Luca Brayda presented the “4×4 SMP demo” at the Haptics Symposium 2016 conference held from April 8th till 11th 2016 in Philadelphia, Pennsylvania. In addition to that also a publication was successful at the Symposium.

Impressions from the Symposium


Workshop on Multisensory Interaction and Assistive Technology

We organized the first Workshop­ on Multisensory Interaction and Assistive Technology. This was co-organized with scientists in the field of neuroscience, engineering and human-machine interfaces. Within the workshop, the following talk was given: Can refreshable tactile displays be a complementary tool in rehabilitation setups for visually impaired people (by Luca Brayda)?

Image of the Workshop on Multisensory Interaction and assistive technology

The workshop website can be visited at: