Design and Evaluation of a Protocol to Assess Electronic Travel Aids for Persons Who Are Visually Impaired

Article excerpt

Abstract: This study evaluated a protocol that was developed to assess how beneficial electronic travel aids are for persons who are visually impaired. Twenty persons with visual impairments used an electronic travel device (Trekker) for six weeks to conform to the protocol, which proved useful in identifying successful users of the device.


Persons who are visually impaired (that is, those who are blind or have low vision) typically experience problems with mobility and wayfinding. Not only can these problems result in limited activity, but they can restrict social participation (Marston & Golledge, 2003). One of the major concerns of persons who are visually impaired with regard to wayfinding is the lack of information they are able to obtain from their environment while traveling and crossing intersections (Loomis, Golledge, Klatzky, & Marston, 2007; Ponchillia, Eniko, Freeland, & La Grow, 2007). Electronic travel aids increase opportunities for independent wayfinding by providing information about the user's current location and with navigational instructions regarding the route to a destination. These devices are intended to be used in addition to, not instead of, a white cane or dog guide.

A number of electronic travel aids are available in the marketplace, including Trekker and BrailleNote GPS (both manufactured by Humanware) (for a recent overview of such devices, see Roentgen, Gelderblom, Soede, & de Witte, 2008). The positive impact that these tools have on the daily lives of people with visual impairments in terms of providing opportunities and promoting independence is promising. For example, Zabihaylo (2008) demonstrated that Trekker stimulated its users to explore new environments and enhanced their sense of security after one year of use. In single-subject experiments with BrailleNote GPS, Ponchillia et al. (2007) found that the device's use can lead to greater wayfinding performance than the use of general orientation and mobility (O&M) skills, even in highly familiar areas. These investigators recommended that GPS technology for people who are visually impaired should become part of rehabilitation and educational programs for both the simple and the more complicated functions of the devices.

Learning how to use an electronic travel device independently generally requires a considerable amount of training and motivation, and may not be possible for every individual who is visually impaired. To avoid prescribing a device to a visually impaired applicant who may not benefit from its use, rehabilitation centers and health insurance companies need to consider the efficacy of a device for a potential user before it is purchased. However, as Jutai, Strong, and Russell-Minda (2009, p. 219) stated, as yet there is a "deficit of effective and standardized outcome measures for evaluating satisfaction, success, and performance with assistive technologies." On request of the Dutch Health Care Insurance Board (College voor Zorgverzekeringen, n.d.), we therefore designed and evaluated a two-phase protocol to assess how beneficial a particular electronic travel device is for an individual with visual impairment, with regard to the goal of independent O&M. In Phase 1 of the protocol, the Identification Phase, the characteristics of a person who is visually impaired are tested against identification criteria to identify those who may benefit from the use of an electronic travel device. After the most appropriate device with respect to the person's mobility problems and wishes is selected, the person enters Phase 2, the Intervention Phase, which consists of structured training in the use of the device and repeated tests to assess the person's ability to operate the device. The person is encouraged to use the device frequently between training sessions. On the basis of this two-phase protocol, the decision can be made whether the use of the device meets the individual's reported mobility needs and whether the device should be prescribed. …


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