Amazability: A Research Activity of the Minerva Brooks Memorial Library, Inc.Haptic Guidance |
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What is Haptics?The term haptic comes from the Greek "haptikos", meaning "to touch". In this sense, Braille material found in hard copy books, tactile drawings, embossed figures, and maps are examined using the haptic or touch sense. Here, information is transferred by one's actively feeling material that is fixed or unchanging. Another use of the term "haptic" concerns the use of vibrotactile devices such as grips, joysticks, etc. found in electronic games. The grip is vibrated or moved in concert with the game's action scenes. This is called "haptic feedback." It is also employed in cell phones, touch screens, and the like. The ultimate use of the term "haptics" is that in which devices and associated software are used to simulate real objects. This is termed "virtual reality modeling" or "rendering." The modeling system employs a mechanical linkage that it can manipulate. At the user-end of the linkage is a stylus that can be held like a pen. Alternatively, a thimble-like attachment, into which the finger can be inserted, may be provided.
Using a thimble cursor on the Phantom Premium 1.0 from Sensable The user observes a display of the object being rendered, e.g. a sculpture, a model of a building, a three-dimensional geometric form, etc. The position of the stylus is also displayed on the screen. The user actively maneuvers the stylus around a completely empty volume of space and, owing to the forces exerted, can actually "feel" the object as though it were present. This active probing or feedback can be supplemented by a mode in which the stylus is "pulled" or guided by the modeling system. An enormous advantage of this approach is that any object can be simulated or rendered using only software. Moreover, the objects can be dynamically changed so that the user may feel the model transitioning from one form to another.
The Falcon from Novint There are numerous companies offering haptic modeling systems. Key innovators include Sensable and Novint. These systems are priced at a level that schools, book publishers, and libraries can afford. The Novint Falcon is priced low enough to be purchased by individuals with visual impairment.
Our approachNearly all haptic modeling systems have relied upon the active feeling by the user of the virtual object. This has been successful, since the user can simultaneously feel and see the model. For those who are visually impaired, we intend to verbally describe the elements of the model while simultaneously guiding or "pulling" the user's hand around the model. For example, the presentation might begin by telling the user that the object to be examined is a cube. The device would then pull the finger around the edges of the cube while at the same time describing verbally what is being felt. A circuit diagram might be traced in this manner, with the component types and values being called out. Chemical diagrams can be examined and even the forces acting within chemical bonds demonstrated. Research studies have shown that persons with visual impairment can use haptic devices to discriminate successfully extremely complex shapes. Some studies have demonstrated success in rendering sculptures while others have presented complex geometrical shapes. The Amazability Research Group at the Minerva Brooks Memorial Library, Inc. looks to develop haptics authoring tools with which book publishers and teachers with normal vision could create presentations. An illustration could be verbally described while the haptic stylus is guided around the elements of a figure. The resulting "haptics tutorial" can be "played back" by the student using a Haptics Presenter. By feeling the model while listening to its description, the student can begin to "see" the object being presented, thereby strengthening powers of visualization. Virtually any kind of real-world object or illustration can be rendered in the form of a voice-accompanied haptic tutorial. Since they are entirely electronic, i.e. created in software, they can be used anywhere an appropriate haptic device exists. In fact, such tutorials can be used over the Internet or made part of an electronic or DAISY book. This technology, when available, will open up a whole new world for persons with visual impairment.
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