Abstract—This project developed and evaluated the utility of a mobility assistant cognitive prosthetic that leverages the computing power and GPS location determination capabilities of smart phones to provide location-sensitive mobility assistance. New relatively inexpensive smart phones offer powerful computing and location sensing capabilities. A prototype cognitive prosthetic was developed to assist users in their use of transportation systems. User Interface design included remote caregiver programming features, and automated SMS status generation. Location specific memory cues are triggered by comparing current GPS coordinate location with expected route coordinates obtained from stored route databases based on the GTFS feeds from transit systems. Additional development focused on developing algorithms to identify potential user errors, such as wrong-bus. These reminders and instructions will allow cognitively disabled persons to utilize public transportation systems with greater confidence leading to greater mobility and independence. I. INTRODUCTION he number of individuals suffering with cognitive disabilities in the United States is greater than 20 million [1]. As the population ages, the number of individuals with cognitive impairment is expected to grow rapidly [2]. The mobility and independence of these individuals is restricted due to their inability to drive a vehicle. Instead, public transportation systems represent the only viable option for independent living [3]. Existing systems aid cognitively impaired individuals through the use of schedule assistance with visual or verbal reminders. However, these systems are not able to provide reminders based on current location, nor are they capable of detecting usage mistakes common to transportation systems like wrong-bus or wrong- or missed-exit. Public transportation systems represent an important societal institution and are virtually the only means available for cognitively impaired individuals who are typically unable to operate automobiles. Manuscript received March 26, 2011. This work was supported in part by the U.S. Department of Education under Grant H133S090055 T. H. Riehle is with Koronis Biomedical Technologies, Inc. Maple Grove, MN 55369, USA (corresponding author to provide phone: 888-274- 1317; fax: 763-463-9000; e-mail: triehle@koronisbiotech.com). S. Anderson and P. Lichter are with Koronis Biomedical Technologies, Inc. Maple Grove, MN, 55369, USA A. W. Brown is Associate Professor of Physical Medicine & Rehabilitation at Mayo Clinic. Dr. Brown’s clinical research activity includes Project Director and Principle Investigator of the Mayo Clinic Traumatic Brain Injury Model System Center funded by the Department of Education through the National Institute on Disability and Rehabilitation Research. D. S. Hedin is with Advanced Medical Electronics, Maple Grove, MN 55369 USA. Proficient use of public transportation systems allows these individuals to remain independent and to be integrated into their communities [4]. The system proposed here seeks to enable these individuals to utilize these complex systems with greater confidence, safety and effectiveness. Transportation is the key element enabling independence for the disabled. Yet, the mobility of cognitively impaired individuals is restricted and their quality of life is impacted because few posses drivers licenses. Specialized transportation systems for the disabled often require reservations to be made ahead of time, and only cover limited regions. Private transportation options such as taxi services are suitable, but are cost prohibitive. Transportation was identified as a significant unmet need among the disabled, with higher levels among respondents under age 65 [5]. The negative consequences of this unmet need impact an individual’s ability to maintain employment and keep important appointments, including medical and therapy. For many individuals ubiquitous public transportation systems represent the only viable option for independent living [3]. However, mastery of complex public transportation systems presents a significant challenge for individuals with cognitive impairment: understanding complex transit schedules and vehicle identification within transportation hubs with many nearly identical vehicles is followed by the challenge of determining where and when to exit the vehicle; a task that requires planning aboard a conveyance on which stops must be requested within the precise locale and inside which the atmosphere may be busy and distracting. Transportation tasks are even more complex when establishing a new routine on routes without familiar milestones. Mistakes, such as wrong-route and wrong- or missed-exit pose a serious dilemma for the cognitively impaired. The early detection of route deviations can alert the disabled traveler and allow the consequences of the mistake to be reduced. Location and time based event notifications will increase the likelihood successful trip aboard a public conveyance. II. METHODS A. Design Overview The objective of the transportation assistant prototype is to utilize the GPS capabilities of smart phones to provide location-based memory cues to individuals with cognitive disabilities to enable them to more effectively utilize public transportation systems. Public Transportation Assistant for the Cognitively Impaired Timothy H. Riehle, Member, IEEE, Shane M. Anderson, Member IEEE, Patrick A. Lichter, Member IEEE, Allen W. Brown, MD, Daniel S. Hedin, Member IEEE T