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Smart Interactive Tactile Interface Effecting Graphical Display for the Visually Impaired


A new tactile device capable of displaying simple graphics and text (in Braille) to be used by the visually impaired and blind people for using most of IT and specially in accessing the Internet. The newly developed device will be competing with an array of piezo electric actuators capable of displaying a single line of Braille text consisting of 40 or 80 characters. Currently available refreshable Braille display units are well developed but they suffer from two main limitations. These devices offer limited value for users as they display limited information and cannot display graphics or mathematical functions. The selling price of these units are quite high. The specifications of the device was drawn by researcher who are closely involved with potential end users. The newly developed device (the ItactI display unit) uses the electrorhological fluid technology. A tablet consists of 128 x 64 tactile pins, which are controlled individually to rise according to the corresponding information to be displayed. The pins are equally spaced (2.5mm pitch) to allow graphics and text to be displayed simultaneously. The unit is designed to display 43 characters by 13 lines of text. Total usable area is 320 x 160mm. Refresh rate is under 7 seconds. The unit also is designed to provide a touch sensitive feedback capability at an individual Braille cell level (a x 4 dots). The ItactI display unit was tested and its performance was evaluated by team of individuals who have long experience in analysing similar equipment. The Itact device is expected to enable end users to access the Internet. Special software package was developed by the consortium to simplify the functionality of the device. The industrial partners are keen in continuing their efforts in developing the ItactI display unit. Manufacturing plans are considered. Main suppliers are identified. Cost of the device is estimated. Marketing study was undertaken. Potential distributors (value added reseller) were identified in four European countries for the first stage of the launch of the product. Detailed questionnaire was completed by interested organisations. The responses in the questionnaire confirmed that there is a clear need for the new device. The study also confirmed the projected selling prices and demand in the four European countries. An expected benefit of the new device is improved access to most of IT equipment. Accessing the Internet by the visually impaired / the blind people will improve the quality of their life. On line shopping and on line information provision will be afforded by an important section. Training and education will be improved. Opportunities to find employment will be enhanced.
To make Graphics fully usable for visually impaired, beside a tactile display (a Dot Matrix Display -DMD-) special software is needed. Within the ItactI-Project, such basic software was developed to present information -text and graphics- to the blind user on the ItactI-display. The program allows presenting the " windows" in tactile form, highlighting the active window. The contents of the window (mainly text) are presented in Braille. Graphic structures can be shown as contour lines, coloured areas by different dot patterns. Simple pictures can be presented "disintegrated" by showing special attributed ( coloured or shaded) parts one at a time (e.g. a map can be shown with all parts, then with borders, then with water bodies, then with wooded or hilly areas, then with cities only, then with railways or roads etc). The program can be used under Windows 2000 and soon will be adapted to XP. Allowing basic functions today, a continuing program development effort is necessary and undertaken.
Electrorheological (ER) fluid is a smart material that changes its properties in the presence of an electric field. To date, the proliferation of ER fluid devices and applications has been restricted due to the difficulties associated with generating large enough electric fields to operate them effectively. Field strengths of the order of 1 MV/m (megavolt per metre) and greater are required producing discernible physical changes in the fluid. An electric field is generated between two electrodes at different potentials. The field strength is proportional to the potential difference between the two electrodes divided by the distance by which they are separated. For this project, it was necessary to produce electrical structures such that the fluid could be operated at voltages as low as 400V or less. Previous work with ER fluid had not demonstrated that this was practical, as it was usual to employ electrode separations ( gap ) of at least 1mm and to apply potential differences of the order 1kV (kilovolt) or more. Therefore, as well as producing highly accurate structures to tight mechanical tolerances in order to produce electrode gaps of order 250 micrometres, the project required the development of a fluid that was suitable for use in such confined volumes. The class of ER fluids that was required for this application consists of solid particles dispersed in oil. These particles had sizes as large as 50-100 micrometres. This presented difficulties when used in confined spaces as their behaviour was unpredictable and inconsistent due to poor mobility of particles. It was hence necessary to develop a fluid that could be used when subjected to such confinement. The consortium therefore set about developing a means of preparing particles of order 10 to 20 micrometres for use in this environment. The new particles offered significant challenges with regards to reduced yield, difficulties associated with moisture loss and absorbtion and increased current consumption. All of these challenges were overcome to develop a new range of “low voltage” fluds that could be used in this environment that were still compatible with sealing materials, non-toxic and safe for disposal.