Objective Mobility Documentation Using Emerging Technologies

Abstract

Historically, rehabilitation clinicians who work with people who are visually impaired (that is, are blind or have low vision) have relied on subjective checklists and clinical assessments to document the capacity of individuals to perform various tasks, including mobility, and to assess the impact of rehabilitation. Numerous instruments have been developed to measure functional outcomes and the quality of life of people who are visually impaired (De l'Aune, Williams, Watson, Schuckers, & Ventimiglia, 2004; Haymes, Johnston, & Heyes, 2001). The continued development and implementation of such instruments represents a major achievement in the coordination and standardization of measurements of functional outcomes. This article highlights a unique, objective method for assessing the mobility of clients who are visually impaired by using a combination of GPS (Global Positioning System), GIS (Geographic Information Systems), and accelerometer technologies. The use of these technologies facilitates a highly objective and reliable measurement of both indoor (accelerometer) and outdoor (GPS and accelerometer) mobility and travel patterns. Moreover, measures of mobility can be used in conjunction with other commonly used self-report and clinician-assessed measures of mobility-related behaviors, including those that assess the impact of vision loss on mobility. GPS AND GIS TECHNOLOGY GPS technology, which provides information on the spatial coordinates of a given geographic location or traveler that is derived from signals received simultaneously from multiple GPS satellites, is often used in conjunction with GIS, which provides digital mapping and other important information about a specific location. In simple terms, GPS determines an individual's geographic location, travel paths, and speeds, while GIS provides a multilayered platform that is typically displayed in maps that can be used to interpret GPS data. GPS technology has been used to investigate details about personal travel behavior (Wolf, Guensler, & Bachman, 2001; Wolf, Loechl, Thompson, & Arce, 2003) and the relationships between physical activity and travel patterns. By equipping participants who are visually impaired with GPS data loggers, investigators can process data on second-by-second GPS positions, time, and speed within a GIS framework to obtain in-depth information about various outdoor behaviors, including travel times, modes of travel, the duration of stops, the length of trips, speed profiles, routes, and types of travel environments. This information can then be augmented with information on the specific purposes of travel and levels of independence that is gathered from self-report travel diaries and assessment interviews. These behaviors are closely related to the goals associated with orientation and mobility. GIS technology involves spatial analysis software platforms that are used to manage and evaluate geographically referenced data (Brainard, Bateman, & Lovett, 1995; Brainard, Lovett, & Parfitt, 1996; Lee & Stucky, 1998; Loh, Van Stipdonk, Holtfrerich, & Hsieh, 1996; Lovett, Parfitt, & Brainard, 1997). It can be used to generate detailed information on travel routes that an individual who is visually impaired has collected via GPS. In addition, extensive comments or notes about specific features of various GIS themes, such as bus routes, commercial and entertainment districts, and other relevant community information, can be integrated into the data system. METHODS This study was conducted by researchers at the Atlanta VA Rehabilitation Research and Development Center and at GeoStats () to evaluate the efficiency of the procedures, the quality of the data, and the effectiveness of the concepts of the three technologies. It was approved by the Emory University Internal Review Board, and the participants signed informed-consent forms before they participated. …