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Licentiate thesis, Calle
In his licentiate thesis, Calle Sjöström sums up his own and Certec's experience from almost five years' work on haptic interfaces for people with disabilities. The haptic technology tested have great potential for future development, but need refinement and perfection to be useworthy for the intended user group.
Sjöström introduces the concept of "virtual search tools" to assist a blind person when exploring unknown virtual environments. He also analyzes the properties required in a force feedback device to make it suitable for haptic access. This involves manipulandum design, the size of the workspace, and not least the benefit of 2.5D devices. When trying to transform a popular program for the PHANToM 3D device to suit a 2D device, he discovered that, even though it seemed to be a 2D task, it could not be done.
At Certec, rehabilitation engineering research is viewed partly as a subset of design research. Design requires reflection-in-action. It does not remove people, objects or events from their context - to be studied separately. Sjöström's work has developed in accordance with this view during the design and testing of the haptic interfaces described in this thesis.
Today, computers are important tools for blind people, but they are mostly used as text machines. The wide adoption of the Internet as an information channel has led to a minor revolution for people with visual disabilities by giving them access to information that was previously inaccessible. Graphical interfaces like Windows have made computers more accessible and easier to use for the majority of people. Unfortunately, the graphical interface is an obstacle rather than an improvement for people with visual disabilities.
Certec has been working on touch interfaces - haptic interfaces since 1995, exploring the possibilities they can offer people with different kinds of disabilities. With a haptic computer interface, a blind person can play haptic computer games, learn mathematics by tracing touchable mathematical curves, and gain better access to graphical user interfaces like Windows.
This thesis attempts to condense experience and ideas that have resulted from our work, which began with the PHANToM (from SensAble Technologies Inc.) and now includes force feedback joysticks, the FEELit mouse (from Immersion Corp.), as well as other haptic devices. The differences between the 3D-haptics provided by the PHANToM and the 2D-haptics provided by the FEELit mouse are analyzed.
It is established that our early work on the PHANToM generated useful fundamental knowledge and a head start in our thinking which were of great use when we had the opportunity to try the FEELit mouse.
Three concept studies in the area of haptic Windows access are presented:
· FEELit Desktop from Immersion combined with synthetic speech and Braille for general Windows access
· Radial haptic menus to maximize the use of a small haptic devices
· A set of virtual haptic tools to be used as aids for searching disordered virtual objects like icons on the desktop.
A prototype of the FEELit mouse and pre-release software were used to implement test programs and to carry out a limited case study with two blind users. All of the concepts were considered to be useworthy as soon as the teething troubles and instabilities of the early implementations have been eliminated. The testers were very enthusiastic about the concept of haptics as a means of gaining better access to Windows in general and they had many ideas about possible uses for this kind of technology.
The results clearly justify further research, testing, and refinement of the use of haptics for computer access.
This licentiate thesis is based on the following papers:
of touch provides new computer interaction techniques for disabled people
C. Sjöström, K. Rassmus-Gröhn
Article published in Technology & Disability (IOS Press) Volume 10, Number 1, 1999
Force Feedback Device to Present Graphical Information to People with Visual Disabilities
K. Rassmus-Gröhn, C. Sjöström
Short paper presented at the Second Swedish Symposium on Multimodal Communication, Lund, Sweden, Oct 1998
Phantasticon - The PHANToM for blind people
Article presented at the Second PHANToM Users Group, Dedham MA, Oct 1997
To Use the
Sense of Touch to Control a Computer and the World around You
C. Sjöström, B. Jönsson
Article presented at the AAATE conference, Thessaloniki, Greece, Sep 97
Keywords: Haptic, IT, Access methods, Disability, Windows, Blind, Mobile Impairment
[PDF-format 379 kb] The IT Potential of Haptics - touch access for people with disabilities.
[TXT-format 83 kb] The IT Potential of Haptics - touch access for people with disabilities.
Appendix: Article published in Technology and Disability [PDF-format]
Last Modified: 03-03-11