INTRODUCTION

Mobility-vulnerable populations, i.e., individuals lacking the ability and/or resources to be mobile due to permanent or temporary factors, include many people with disabilities (PWDs). The autonomy to be mobile independently allows greater participation in community and family activities, job opportunities, and access to healthcare and education. However, transportation has been, and remains, among the most challenging barriers to full inclusion, self-sufficiency, and independence for PWDs, often placing a burden on paid or unpaid caregivers [1]. While tremendous efforts, including the emergence of self-driving vehicles, implementation of accessible features and transportation systems have been made, walking between home and bus stops [2-4], traversing vehicle boarding and disembarking, and ensuring the safety of passengers and their personal belongings are well-known issues and sources of injury for PWDs [5-7]. It gets more challenging and dangerous when PWDs carry weight, such as medical equipment (i.e., oxygen cylinders, ventilators), suitcases, and shopping bags. Holding asymmetrical loads is common during many daily and occupational activities; however, depending on the load mass, it may alter postural stability and lead to falls [8]. Different solutions for PWDs carrying weight, such as mobile carts, backpack or fanny packs, smart home technologies, autonomous delivery robots (ADR), and weight carrying assistive robots (WeCAR), were developed to support PWDs. However, the challenges and issues PWDs encountered have yet to be addressed fully with existing solutions. To our knowledge, no study has comprehensively assessed the 5A's (Availability, Accessibility, Acceptability, Affordability, and Adaptability as defined in Table 1) of those solutions. While weight carrying assistive robots (WeCAR) are emerging, how PWDs perceive these technologies are not yet understood. This paper aimed to gather information about the current technology solutions for carrying weight for PWDs during physical access and transportation, assess those solutions in 5A's, and collect user opinions on a commercially available weight carrying robot.

METHODS

We evaluated the current industry and research in providing weight carrying support for PWDs and their 5A's. We reviewed lower and high-tech technologies and services available. This included the collection of brochures, technical specifications and diagrams, and descriptions of any user interfaces and controls. We reviewed the last ten years of research published on ADR and WeCAR designed specifically for PWDs and assessed their 5A's. We then demonstrated a commercially available weight carrying robot (Gita robot, as shown in Figure 1) to nine community dwelling older adults with different impairments and two physical therapists for a senior living community via a focus group study. We collected their opinions regarding the potential usefulness of the robot and the features/functions they would like to include in the robot. Thematic analysis was used to explore and identify themes regarding the use cases and the needs of the Gita robot.

RESULTS

The state-of-the-art technology to support PWDs carrying items and how each technology meets the 5A's was summarized in Table 2. The low techs are more affordable and available but less accessible, adaptable, and acceptable for PWDs, as they could cause difficulty navigating, safety concerns in crowded conditions, problems with boarding and disembarking, or strain injuries and pain. The high techs, such as robots and delivery services, are more adaptable and accessible but less affordable and acceptable as PWDs were not included during the design and development.

Keys: A1: availability; A2: acceptability; A3: accessibility; A4: affordability; A5: adaptability. Meanings of the symbol: Smile face J (J): the technology meets the specific A in large. Neutral face K (K): the technology meets the specific A but has limitations. For example, not available for all; acceptable but may have safety concerns, cause strain or pain; not accessible for all; not affordable for all; or limited adaptability. Frown face L (L): the technology fails to meet the specific A's in large.

When specific weight carrying robots were examined, ADRs were gaining popularity due to their potential to revolutionize delivery systems and their wide applications in various sectors, such as retail, hospitality, and healthcare [11, 12]. ADRs include sensors and navigation technologies that enable them to travel on roads and/or sidewalks without a human operator. Although several commercial ADRs [13-17] are available, they are not readily usable for PWDs as they are not designed to interact directly with PWDs. For example, most ADRs do not have accessible features as they were developed mainly for delivering food and grocery between different locations. They may even bring obstacles to PWDs. The University of Pittsburgh suspended the Starship ADR as it got wheelchair user accessible challenges and safety hazards [18]. While the Gita robot [19] is designed to help people carry personal items, its application to the 5A's for PWDs is limited and untested. Labrador robots [20] were designed to move large loads and keep smaller items within reach at home. There were some reported user cases from people with Multiple Sclerosis and stroke, but their availability, acceptability, and usability were largely scarce. The 5A's of ADRs and two WeCARs were summarized in Table 3.

The focus group was conducted at the resident activity center in a senior living community. Nine senior adults (three with hard of hearing and deaf, three with mobility impairment, two with visual impairment, and one with mild cognitive impairment) and two physical therapists joined the demonstration and discussion. The authors demonstrated the existing features and function of the Gita robot and how to load, unload, and set up the robot. The participants were allowed to ask questions and try the robot during the demonstration. The attendees were excited to learn about the Gita robot and its various applications. They suggested many ideas to improve the device and make it more useful for individuals with different impairments. Three themes were identified from the discussions: 1) physical robot design, where the participants loved the overall appearance and load capacity but suggested a modular design (to allow different users to carry different objects, such as garden tools, books, cakes, and to enable different users to benefit from different features and functions) with a smaller footprint (to go through narrow space and under tables). 2) safety of the robot, where the attendants expressed their concerns about the items being transported and the safety of the user and individuals in their home and community. 3) additional use cases where all participants wanted features such as health metric monitoring (synchronized with other wearables and devices), fall detection (as the robot follows the user, it could detect the falls and inform 911 or family members or caregivers), and sitting on the robot for taking rest. A few participants wanted to modify the robot to be fully autonomous instead of following a human. Individuals with hard of hearing raised concerns about how to communicate with the robot (the robot has a built-in speaker but is not used for talking with a user).

DISCUSSION AND CONCLUSIONS

Public transportation use is associated with multiple benefits for PWDs, such as increased physical activity, improved access to services and employment for PWDs, reduced transportation and healthcare costs, lower carbon emissions, better mental health, and greater transportation safety. However, PWDs are experiencing challenges to fully benefit from the current, even the future public transportation as technologies such as self-driving evolve. It is recognized by the literature and voices of PWDs and their assistants that carrying weight is one of those challenges that limit not only their access to public transportation but also physical access and mobility. Findings from this paper suggested that existing solutions, including low and high technology and services, were not addressing the issues in 5A's. The application of robotics and automation can potentially improve opportunities for an equitable transportation chain that meets the needs of the diversity of travelers with disabilities. Our focus group results indicated the enthusiasm of PWDs on WeCAR and provided insights for the further development of WeCARs to meet the 5A's. Additionally, it is crucial to include the PWDs in the technology design and development.