Paul Blenkhorn

Personalising web page presentation for older people

This paper looks at different ways of personalising web page presentation to alleviate functional impairments in older people. The paper considers how impairments may be addressed by web design and through various personalisation instruments: accessibility features of standard browsers, proxy servers, assistive technology, application adaptors, and special purpose browsers. A pilot study of five older web users indicated that the most favoured personalisation technique was overriding the CSS (cascading style sheet) with a readily available one using a standard browser. The least favoured one was using assistive technology. In a follow-up study with 16 older web users, performing goal-directed browsing tasks, overriding CSS remains the most favoured. Assistive technology remains the least favoured and the slowest. Based on user comments, one-take-home message for web personalisation instrument developer is that the best instrument for older persons is one that most faithfully preserves the original layout while requiring the least effort.

Blink detection for real-time eye tracking

This work is motivated by our goal of providing non-contact head and eye based control of computer systems for people with motor difficulties. The system described here uses spatio-temporal filtering and variance maps to locate the head and find the eye-feature points, respectively. These feature points are accurately tracked in the succeeding frames by using a modified version of the Lucas?Kanade tracking algorithm with pyramidal implementation. Accurate head and eye tracking results are obtained at a processing rate of more than 30 frames per second (fps) in more than 90% cases with a low false positive blink detection rate of 0.01%. This is achieved under varying lighting conditions for people of different ethnicity, with and without wearing glasses.

Using speech and touch to enable blind people to access schematic diagrams

A novel approach for enabling blind people to interact with computer-generated graphical information is presented. The paper discusses how computer-generated, text-based information is presented to blind people and then identifies the difficulties in providing similar access to the range of graphical information presented by computer systems. A computer-based system that allows blind users to read, create and edit one type of schematic diagram, namely data flow diagrams used in software engineering, is presented, together with the mapping from the original diagram to a suitable generic, tactile diagram. Results of the evaluation of the approach are given, as are suggested adaptations of the approach that can present tabular information and time-ordered schematic diagrams to a user.

A system for enabling blind people to identify landmarks: the sound buoy

This paper describes a set of low-cost sound beacons. The paper introduces the problem area that motivated the work, considers alternative solutions and describes the radio triggered solution adopted. The paper discusses further developments to make the system suitable for indoor as well as external use.

A system for converting print into braille

This paper describes a method for converting text into braille, in the form in which it is stored as in a computer. The system has been designed to be configurable for a wide range of languages and character sets, and uses a predominantly table driven method to achieve this. The algorithm is explained in the context of the conversion of text into Standard English Braille (British), and the tables for this transformation are given. Particular importance has been attached to enabling braille specialists, who are not experts in computer algorithms, to be able to modify the system for either slight modifications to an existing braille code translator, or for producing a braille code translator for a new language.

TeDUB: A System for Presenting and Exploring Technical Drawings for Blind People

Blind people can access and use textual information effectively in a variety of ways - through Braille, audiotape or computer-based systems. Access and use of graphic information is much more problematic, with tactile versions both time-consuming and difficult to make and textual descriptions failing to provide independent access to the material. The TeDUB Project is developing a system which will automatically generate descriptions of certain classes of graphics (electronic circuit diagrams, UML diagrams and architectural plans) and allow blind people to explore them independently. This system has great potential in work, education and leisure domains to open up independent access to graphic materials for blind people.

Presenting UML Software Engineering Diagrams to Blind People

The TeDUB system promises to deliver a UML diagram tool accessible to blind software engineers. The system uses a number of different interfaces and representation techniques to overcome the challenges of making diagrams created with the Unified Modeling Language usable for blind people. The system is entirely automated and does not require special preparation of UML diagrams by a sighted user. The results of evaluation of the system with thirty-six users were positive. The system was well-received and the participants were able to complete set UML tasks.

Screen magnifiers: evolution and evaluation

While the new generation of screen magnifiers might offer more features, they might not necessarily become more effective. The paper considers how performing usability studies helps researchers understand issues related to screen magnifier design, especially in terms of interface, functions, and features.

Development of an electronic pictorial asthma action plan and its use in primary care

OBJECTIVE Self-management education and the issuing of a written action plan improve outcomes for asthma. Many do not receive a plan and some cannot use the written word. We have developed an electronic pictorial asthma action plan (E-PAAP). METHODS A pictorial action plan was incorporated into a software package. 21 general practices were offered this tool and the software was loaded onto 63 desktop computers (46 GPs and 17 nurses). Usage was assessed and health care professionals questioned as to its use. RESULTS 190 plans had been printed in a 4-month period (17 for test purposes). The individual usage rate ranged from 0 to 28 plans. Doctors printed 73% (139/190) a mean of 3 per doctor and nurses printed 27% a mean of 2 per nurse (37/190). Excluding the test copies, 116/173(67%) were printed as picture and text together. CONCLUSION Nearly half of all healthcare professionals used the E-PAAP software. Usage was skewed with some individuals using the software significantly more than others. The software package should help overcome problems of access to paper templates, by calculating peak flow action thresholds and by prompting correct completion. Barriers to the use of asthma action plans, such as perceived time constraints, persist. PRACTICE IMPLICATIONS The development of an electronic asthma action plan facilitates health professional access to a basic template and prompts the user as to correct usage. It is to be hoped that such facilitation enhances the number of action plans issued and in this study GPs were greater users than the nurses.

Full-screen magnification for windows using DirectX overlays

This paper presents the basic features of software-based magnifiers used by some visually impaired people to read information from a computer screen. The paper briefly presents two major approaches to full-screen magnification for modern multiple window systems (the paper focuses on Microsoft Windows). This paper describes in detail the architecture and operation of a full-screen magnifier that uses Microsoft DirectX Overlays. This approach leads to a robust magnifier that has a low computational overhead. The magnifier has problems with video cards that use a YUV color model but these problems may be addressed by RGB to YUV translation software - an issue that is still to be investigated. The magnifier also has problems when the generic device driver, rather than the manufacturers device driver, is installed on the system. The paper presents two further strategies for full screen magnification, namely, using multimonitor support and true type fonts for text enlargement.