Team BFH-CybaTrike at Cybathlon 2020

24. Février 2020
Februar 2020
CYBATHLON 2020 postponed due to coronavirus In view of the current situation, the CYBATHLON is postponed from 2-3 May 2020 to 19-20 September 2020.

The Institute for Rehabilitation and Performance Technology (IRPT) will be participating as Team BFH-CybaTrike in the forthcoming Cybathlon 2020 from 19 to 20 September in Zurich. Here, we describe our preparations for the championship including improvements in technology and human performance with respect to our bronze-medal-winning achievement at the 2016 event.

Cybathlon

The Cybathlon is a technology-driven competition for people with disabilities that tests the limits of performance of human and machine alike. The championship, which was conceived by Professor Robert Riener from the ETH Zurich, is comprised of six disciplines and races in which several pilots compete simultaneously: brain-computer interface race, functional electrical stimulation (FES) bike race, powered arm prosthesis race, powered leg prosthesis race, powered exoskeleton race, and powered wheelchair race.

FES Bike Race

Bern University of Applied Sciences will be represented in the FES bike race by Team BFH-CybaTrike. The CybaTrike is a recumbent tricycle developed at the IRPT that has been augmented with FES stimulation hardware and control algorithms to allow people with complete lower-limb paralysis following spinal cord injury to propel the tricycle by muscle power alone: the paralysed muscles are activated by electrical impulses applied through the skin, and coordinated with the intended cycling motion.
A range of scientific studies have proven that this type of exercise has many benefits for people living with a spinal cord injury: in addition to facilitating mobility and recreation, FES-cycling brings substantial improvements in fitness, musculoskeletal condition, and general health.
The team from BFH-IRPT, including pilot Julien Jouffroy, previously competed in the FES bike race in the first-ever Cybathlon in Zurich in October 2016. At that event, the BFH-IRPT team achieved third place and won the bronze medal. In fact, our team’s final-round performance was the fastest overall time of the ten FES-bike pilots that used surface electrodes; due to a slower time in the qualifying race, however, our pilot was in the B-final and therefore won the bronze medal. The eventual gold-medal winner, from Team Cleveland USA, had the clear advantage of using a fully implanted muscle stimulation system. Our team’s experiences along the road to Cybathlon 2016 are documented in an article [1].

SNSF Project

Since the first Cybathlon, Team BFH-CybaTrike has been investigating several potential improvements in the CybaTrike technology and in our pilot’s training programme. These developments have drawn extensively from experience gained in a major scientific project on FES cycling that was funded by the Swiss National Science Foundation (SNSF) and completed in June 2017. During that project, which was titled “Performance Optimisation for Paraplegic FES-cycling”, we developed novel techniques for muscle stimulation that used multiple sequentially and spatially distributed electrodes [2], and randomised stimulation patterns [3], to improve power output and to slow the onset of muscle fatigue. The SNSF-funded research project provided a major boost for Cybathlon 2016 and it has given clear direction to potential optimisations that have been investigated in preparation for Cybathlon 2020.
The two principal BFH team members at Cybathlon 2016, Dr. Marco Laubacher and Dr. Efe Anil Aksöz, were supported as PhD students within the SNSF project at the IRPT, and they successfully defended their PhD theses in September 2018. Marco Laubacher’s main original contribution was the development and evaluation of multi-electrode stimulation configurations [2], while Efe Anil Aksöz focused on randomised modulation of stimulation-impulse sequences [3]. Further developments of the CybaTrike have focused on improved real-time biofeedback of key performance variables for the pilot, and on automatic, continuously variable gear shifting.

The Road to Cybathlon 2020

It is hoped that optimisation of the FES-cycling technology will bring incremental improvements in performance, but we envisage that the physiological condition and training status of the pilot himself will be the decisive factor that will determine overall performance and competition outcome. While pilot Julien Jouffroy had only a few months to prepare for Cybathlon 2016, he has been continuously training since that time in an effort to increase the strength and endurance of his leg muscles: Julien has access to a stationary FES-cycle training system in his hometown, and endeavours to train four to five times per week. In the workup for Cybathlon 2020, we have engaged closely with Julien to optimise his training programme by including elements of high-intensity interval training, in an effort to maximise performance. An encouraging outcome was that Julian took first place in the FES bike race at the Lyon Cyber Bike event in September 2019. Furthermore, Team BFH-CybaTrike comes together regularly for intensive, two-to-three-day training camps where overall performance outcomes are quantitatively measured and assessed.

Networking and Dissemination

Finally, it is significant to note that elements of the CybaTrike technology are spinning off via industrial collaboration into commercial products – this aspect is highlighted in the companion article by Sebastian Tobler, CEO of the company GBY AG and fellow academic at Bern University of Applied Sciences – and into further scientific studies involving the network including GBY, BFH-IRPT, Swiss Paraplegic Research in Nottwil, the University of Lausanne, and EPFL.

Conclusion

We are looking forward to participating in Cybathlon 2020, to sharing our experiences and expertise with other teams and colleagues from around the world, and to taking forward the technology and its everyday uptake for the benefit of people living with disability.

References

[1] M. Laubacher, E. A. Aksöz, I. Bersch, and K. J. Hunt, “The road to Cybathlon 2016 – functional electrical stimulation cycling team IRPT/SPZ”, Eur. J. Transl. Myol., vol. 27, no. 4, pp. 259–264, 2017. https://doi.org/10.4081/ejtm.2017.7086
[2] M. Laubacher, E. A. Aksöz, A. Brust, M. Baumberger, R. Riener, S. A. Binder-Macleod, and K. J. Hunt, “Stimulation of paralysed quadriceps muscles with sequentially and spatially distributed electrodes during dynamic knee extension,” J. Neuroeng. Rehabil., vol. 16:5, 2019. https://doi.org/10.1186/s12984-018-0471-y
[3] E. A. Aksöz, M. A. Luder, M. Laubacher, R. Riener, S. A. Binder-Macleod, and K. J. Hunt, “Stochastically-modulated inter-pulse intervals to increase the efficiency of functional electrical stimulation cycling,” J. Rehabil. Assist. Technol. Eng., vol. 5:1–6, 2018. https://doi.org/10.1177/2055668318767364
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