The Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto ON, Canada.
J Neuroeng Rehabil. 2013 Aug 7;10:90. doi: 10.1186/1743-0003-10-90.
Older adults are the most prevalent wheelchair users in Canada. Yet, cognitive impairments may prevent an older adult from being allowed to use a powered wheelchair due to safety and usability concerns. To address this issue, an add-on Intelligent Wheelchair System (IWS) was developed to help older adults with cognitive impairments drive a powered wheelchair safely and effectively. When attached to a powered wheelchair, the IWS adds a vision-based anti-collision feature that prevents the wheelchair from hitting obstacles and a navigation assistance feature that plays audio prompts to help users manoeuvre around obstacles.
A two stage evaluation was conducted to test the efficacy of the IWS. Stage One: Environment of Use - the IWS's anti-collision and navigation features were evaluated against objects found in a long-term care facility. Six different collision scenarios (wall, walker, cane, no object, moving and stationary person) and three different navigation scenarios (object on left, object on right, and no object) were performed. Signal detection theory was used to categorize the response of the system in each scenario. Stage Two: User Trials - single-subject research design was used to evaluate the impact of the IWS on older adults with cognitive impairment. Participants were asked to drive a powered wheelchair through a structured obstacle course in two phases: 1) with the IWS and 2) without the IWS. Measurements of safety and usability were taken and compared between the two phases. Visual analysis and phase averages were used to analyze the single-subject data.
Stage One: The IWS performed correctly for all environmental anti-collision and navigation scenarios. Stage Two: Two participants completed the trials. The IWS was able to limit the number of collisions that occurred with a powered wheelchair and lower the perceived workload for driving a powered wheelchair. However, the objective performance (time to complete course) of users navigating their environment did not improve with the IWS.
This study shows the efficacy of the IWS in performing with a potential environment of use, and benefiting members of its desired user population to increase safety and lower perceived demands of powered wheelchair driving.
老年人是加拿大使用轮椅最普遍的人群。然而，由于安全和可用性方面的考虑，认知障碍可能会阻止老年人使用动力轮椅。为了解决这个问题，开发了一种附加的智能轮椅系统（IWS），以帮助认知障碍的老年人安全有效地驾驶动力轮椅。当附加到动力轮椅上时，IWS 添加了基于视觉的防撞功能，可防止轮椅撞到障碍物，以及导航辅助功能，可播放音频提示，帮助用户绕过障碍物。
进行了两阶段评估，以测试 IWS 的功效。第一阶段：使用环境 - 评估 IWS 的防撞和导航功能与长期护理设施中发现的物体相对抗。进行了六个不同的碰撞场景（墙壁、助行器、拐杖、无物体、移动和静止的人）和三个不同的导航场景（左侧物体、右侧物体和无物体）。使用信号检测理论对系统在每种情况下的响应进行分类。第二阶段：用户试验 - 使用单被试研究设计来评估 IWS 对认知障碍老年人的影响。要求参与者在两个阶段驾驶动力轮椅通过结构化的障碍物课程：1）使用 IWS 和 2）不使用 IWS。在两个阶段之间测量了安全性和可用性，并进行了比较。使用视觉分析和阶段平均值来分析单个被试的数据。
第一阶段：IWS 在所有环境防撞和导航场景中都表现正确。第二阶段：两名参与者完成了试验。IWS 能够限制与动力轮椅发生碰撞的次数，并降低驾驶动力轮椅的感知工作量。然而，使用 IWS 并不能提高用户在其环境中导航的客观性能（完成课程的时间）。
本研究表明 IWS 在潜在使用环境中具有功效，并使期望用户群体中的成员受益，从而提高安全性并降低对动力轮椅驾驶的感知需求。
