Wearable tails help elderly folks keep their balance

In a remarkable intersection of biology and technology, researchers at Keio University Graduate School of Media Design have developed a wearable robotic tail named Arque, designed specifically to assist elderly individuals with balance issues. This innovative prototype, which measures one meter in length, aims to provide a solution to the growing problem of falls among the aging population, particularly in Japan, where nearly 30% of residents are 65 years or older.

The concept behind Arque is rooted in biomimicry, the practice of drawing inspiration from nature to solve human challenges. In the animal kingdom, tails serve various functions that enhance mobility and balance. For instance, cheetahs utilize their tails to maintain stability while sprinting, while monkeys rely on theirs as a counterbalance when navigating through trees. The researchers propose that Arque can replicate these functions for humans, particularly in scenarios like crossing slippery surfaces. When the wearer leans in one direction, the tail swings in the opposite direction, acting as a pendulum to help realign the body's center of mass over the feet.

Mechanically, Arque consists of an articulated structure resembling vertebrae, which is attached to the lower back via a harness. The tail's movement is powered by four pneumatic artificial muscles that operate using compressed air, allowing it to move in eight different directions. Sensors embedded in the device monitor the wearer's posture and weight shifts, triggering the muscles to respond accordingly. This results in a surprisingly lifelike motion, as demonstrated in the team's promotional videos, where the tail appears to twitch and adjust in real-time to the user's movements.

The project first gained attention at the SIGGRAPH 2019 Emerging Technologies showcase, captivating audiences with its unique blend of futuristic design and practical application. However, despite the initial excitement, the project has not progressed significantly since its debut. The research paper authored by lead researcher Junichi Nabeshima and his colleagues has not led to further development, clinical trials, or commercial products, leaving many to wonder about the future of this innovative technology.

Interestingly, the concept of a balance-assisting robotic tail has not been abandoned entirely. A research team in the United Kingdom, led by Ildar Farkhatdinov at Queen Mary University of London, is currently exploring similar ideas. Their work focuses on a Supernumerary Robotic Limb (SRL), which is essentially a wearable robotic tail designed to enhance human balance. This device is mounted on a harness for easy attachment and removal, and its movement is controlled based on the distance of any carried load from the user’s body. Actuating motors not only control the tail's movement but also serve as a counterbalance, improving the overall weight-to-counterweight ratio compared to existing devices.

Preliminary testing of this robotic tail has shown promising results, with an accuracy of 89% in position control and a rapid response time of 57 milliseconds. In trials involving healthy participants, the system has demonstrated its ability to assist with balance, resulting in a 59% reduction in the displacement of the Center of Pressure (CoP) when lifting weights. This improvement in balance could lead to safer postures, particularly in industries where manual labor often requires lifting heavy objects or maintaining awkward positions.

The Future of Robotic Assistance

The development of wearable robotic systems like Arque and its counterparts in the U.K. highlights a growing interest in leveraging technology to address the challenges faced by an aging population. As the global demographic shifts towards an older population, the need for innovative solutions to enhance mobility and prevent falls becomes increasingly critical.

While the initial excitement surrounding Arque has not yet translated into widespread adoption, the ongoing research in the U.K. suggests that the concept of a balance-assisting tail has potential. The advancements in sensor technology, robotics, and materials science could pave the way for more effective and user-friendly devices in the near future.

Why it matters

For creators and technologists, the work being done on wearable robotic tails serves as a reminder of the potential for biomimicry to inspire innovative solutions. By observing and understanding how nature solves problems, researchers can develop technologies that enhance human capabilities. As the population ages, the demand for assistive technologies will likely grow, presenting opportunities for creators to contribute to this important field. Furthermore, the integration of robotics into everyday life could lead to new industries and markets focused on enhancing mobility and safety for all age groups, emphasizing the importance of interdisciplinary collaboration in driving technological advancements.