Silke Pan wins silver in the Cybathlon with the TWIICE exoskeleton

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Paraplegic athlete Silke Pan brilliantly represented EPFL at the 2020 Cybathlon. Wearing the TWIICE exoskeleton designed by EPFL scientists, she finished in second place in the finals.

Competing against athletes from five countries (United States, Russia, Korea, India and France) Swiss paraplegic athlete and handbike champion Silke Pan took part in the 2020 edition of Cybathlon, a cybernetic race organised by ETH Zürich. The former acrobat adorned the TWIICE exoskeleton especially designed for her by EPFL scientists. She raced through a 40 meter-long circuit that included seven types of obstacles like stairs, inclined slopes, rough terrain and a slalom around tables.

TWIICE is a lower limb exoskeleton developed by the EPFL research group REHAssist. It consists of actuated segments at the hip and knee joints that are rigidly interfaced with the thighs and the tibiae. A smart controller coordinates these segments to move according to desired gait trajectories that enable a person with spinal cord injury to walk.

Mohamed Bouri, head of the REHAssist group, don’t hide his satisfaction: « Looking ahead, I would be happy to see this development result in a product marketed by a future startup that would have every chance of becoming a technological flagship in the Lake Geneva region. The Cybathlon has allowed us to explore several control strategies and efficient trajectories. To do even better, we need to push back the limits of our knowledge even further, and that is the beauty of science ».

Improvement of the exoskeleton

“Since the beginning of the training sessions, the exoskeleton has been in constant improvement thanks to Silke’s input and her drive to win,” explains Tristan Vouga, EPFL Cybathlon team leader and co-designer of the TWIICE exoskeleton. “We gained 4 minutes in the last month and 45 seconds during the last training session alone. Our latest upgrade consists of a more flexible foot that can conform to the terrain. More generally, the latest version of the exoskeleton is much more ergonomic and provides more autonomy for its pilot, so Silke for instance can now go directly from her wheelchair into the exoskeleton by herself.”

The current version of the exoskeleton, called TWIICE One, is more compact due to improved design of the motors, thanks to a collaboration with Swiss industry partner Sonceboz SA, specialized in electrical motor manufacturing. According to Vouga, TWIICE One is therefore easier to use than the 2016 model: it is closer to the body because the motors are two times more compact and two times stronger. Other strategic partnerships include a collaboration with the local company Fischer Connectors for improving the ergonomics and usability of cables.

A fundamental right to mobility

“An exoskeleton to assist a person affected by paraplegia does not only concern mobility. It also concerns basic human rights, the right to live as others, the right to share social spaces, the right to walk and to own vertical space,” says Bouri. “Alongside our colleagues in Zürich, our participation via EPFL at the Cybathlon promotes an attitude in favor of increasing access to exoskeleton technology for providing daily assistance to a wider audience.”

The development of TWIICE first began in 2015. The exoskeleton team has won 3 years in a row the « Cybathlon experience », a European exoskeleton competition also organized by the Cybathlon committee. The Cybathlon is a Swiss-organized competition that happens every 4 years to promote technologies that assist people with impairments in their daily activities.

« The Cybathlon demonstrates how a sporting event can stimulate research and development, can drive knowledge creation for society, and open up economic prospects by fostering an entrepreneurial spirit. »

The EPFL Vice-Presidency for Innovation supports the Cybathlon through the sports initiative, which consists of around forty laboratories at the service of sports for the physically challenged, for health and for performance. The initiative is part of the SmartMove network, which brings together 9 regional academic players and contributes to making the Lake Geneva region a prime place for developing projects related to sports and health. The Cybathlon demonstrates how a sporting event can stimulate research and development, can drive knowledge creation for society, and open up economic prospects by fostering an entrepreneurial spirit.

© EPFL 2020 / Alain Herzog

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