Millions of individuals worldwide rely on assistive devices. However, the practical application of such technologies is often hindered by numerous limitations. For example, wheelchairs struggle with stair navigation [1,2], prosthetic limbs face restricted sensory and motor capabilities [3,4,5], and assistive technologies for the visually impaired remain inadequate [6,7]. Furthermore, insufficient communication among developers, individuals with disabilities, therapists, and clinicians frequently results in devices that fail to align with user needs [8]. The objective evaluation of assistive technologies presents an additional challenge, as no standardized metrics currently exist to comprehensively assess their effectiveness [9,10]. These combined factors contribute to the rejection or suboptimal utilization of many assistive devices [11]. For instance, among upper-limb prosthesis users, approximately one-quarter discontinue use, citing issues such as discomfort, high cost, aesthetic concerns, and functional limitations [9].
Nevertheless, the introduction of competitive challenges focused on assistive technologies presents a promising path to tackle these issues. A notable example is CYBATHLON, initiated by ETH Zurich, which originates from the combination of “Cyber” and “Athlon”. Unlike the Paralympic Games, it integrates advanced assistive devices into tasks simulating activities of daily living (ADLs) [12]. This competition highlights the interplay between individual capabilities and cutting-edge technologies. To succeed, research teams are incentivized to advance technological innovation while prioritizing user needs. Additionally, such competitions provide an equitable platform to assess the effectiveness of diverse technological approaches in enhancing the quality of life for individuals with disabilities.
The loss of upper-limb functionality profoundly affects various dimensions of daily living. Current prosthetic solutions are categorized into cosmetic, body-powered (BP) [13,14], and motor-powered (primarily using myoelectric control methods, MP) prostheses [9,15,16]. Each type has distinct advantages and limitations. Cosmetic prostheses primarily serve aesthetic purposes, offering limited functional utility but contributing to psychological well-being, particularly in social interactions. BP prostheses, while effective for heavy-load tasks, are functionally constrained. In contrast, MP prostheses, supported by recent advancements in robotics and artificial intelligence [17,18,19,20,21], demonstrate the highest potential for restoring fine motor skills [19,22], particularly in low-intensity tasks [23,24,25]. As a result, contemporary research predominantly focuses on MP systems [26,27,28]. Nevertheless, no current prosthetic solution adequately addresses all user needs comprehensively [29,30,31].
Since its inception, CYBATHLON has featured the “Arm Prosthesis Race” (ARM Discipline), which aims to evaluate and showcase the comprehensive capabilities of prosthetic arms, including heavy-load lifting, multijoint dexterous control, and sensory feedback integration. To accommodate advancements in assistive technology, the tasks in each competition have become progressively more challenging. Nonetheless, the competition consistently focuses on core technical aspects, such as heavy lifting, fine manipulation, bi-manual coordination, operation within large work spaces, wrist control, and sensory feedback.
Interestingly, despite the increasing complexity of tasks and the predominance of MP-based solutions among participating teams, the champions of the 2016 and 2020 competitions were BP teams (Team DIPO Power, 2016 and Team Makerhand, 2020). BP prostheses, though limited to basic open-and-close functions, excelled because of their superior reliability, lightweight design, and simple control mechanisms. These advantages allowed pilots to operate the devices with greater ease and adaptability. Additionally, by using nonphysiological compensatory movements from the torso, the prostheses’ terminal devices could perform actions equivalent to wrist flexion or rotation. This enabled the pilots to successfully tackle the challenging tasks in the competition. Although the competition allows the use of certain body-compensation “tricks”, the primary goal for both organizers and participating teams is to promote the development of advanced prosthetic technologies. For instance, the 2024 competition introduced new rules that restricted usage of compensatory motion and increased task difficulty, placing greater emphasis on the prosthetic hand’s capabilities, such as strong grip force and force-tactile perception (details provided in Section 2). These challenges pose significant obstacles for both body-powered (BP) and motor-powered (MP) prostheses, as no existing commercial or research-based products are currently able to fully meet all the competition’s tasks.
The HANDSON hand was mainly developed by a collaborative research team from Southeast University and the Suzhou Institute of Biomedical Engineering and Technology (SIBET), Chinese Academy of Sciences. Some team members previously participated in CYBATHLON 2020 as Team Manager and Pilot under the name “Team Hands On”, achieving 8th place. The authors of this paper personally participated in the online challenges held in March 2023 and February 2024, competing as Team SIBET and achieving first and third places, respectively. Most recently, Team HANDSON competed in the CYBATHLON 2024 finals, held in Zurich, Switzerland, in October 2024 (90 points, 1st place). This paper focuses on the efforts made by the HANDSON team in CYBATHLON 2024. It details the pilot’s background, the key technologies employed in the prosthetic device, the training strategies, and the final performance. The findings aim to contribute to the exploration of future prosthetic hand designs with enhanced multifunctionality and to validate their feasibility and usability in addressing real-world challenges. |
