BALANCE: Robotic Exoskeletons Get the Balance Right

Exoskeletons Available at the Moment and Their Shortcomings

The EU-funded BALANCE—Balance Augmentation in Locomotion, through Anticipative, Natural and Cooperative control of Exoskeletons (www.balance-fp7.eu)—project has researched and designed exoskeletons that provide support for standing and walking while avoiding falls. “Future applications are foreseen in rehabilitation training and in advanced support of the elderly and, of course, in all such cases, falls should be avoided and balance maintained,” states Dr. Jan Veneman, project coordinator.

Currently, state-of–the-art exoskeletons are used to provide mobility for paralyzed spinal cord injured patients for short periods of time. Exoskeleton products provide weight support through the standing leg and swing motion to provide support in the swing leg. However, they don't have any means to manage the overall posture or to maintain balance. In these cases, use of crutches, hand support bars, an overhead harness, or even human assistance helps prevent a fall.

BALANCE Systems and Novel Robotics

The main thrust of the BALANCE research was measuring human balance control and how to apply it in robotic systems. Algorithms incorporated loss of balance as measured in real time during movement. Novel robotic devices that pushed humans in a specific direction measured the components of balance control and how it was achieved. The researchers also modeled human balance and how people react to movement support.

Completely new approaches where the exoskeleton provides zero resistance to the user (transparency control) and with head rotation initiating turning in position of the exoskeleton were developed. A first, researchers used an exoskeleton to support reactive stepping to pushes successfully while standing and walking.

One major drawback of current wearable motion capturing systems is that metal structures and electrical components distort their measurements. In collaboration, BALANCE further developed a wearable motion capturing suit to be robust to magnetic disturbances to overcome this problem.

From the Gait Lab to the Human-Cooperative Robotic Exoskeleton Arena

Project researcher ingenuity was the driving force behind the EMY exoskeleton co-developed with other projects that suffered from substantial delays. A mitigation strategy had to be formulated, which involved re-planning the whole of the second half of the project and the use of LOPES II and BAR-TM. Developed by other members of the consortium, LOPES II is a treadmill-based exoskeleton, and BAR-TM is a pelvic support robot.

Taking BALANCE deliverables into the movement rehabilitation center, project results were used to assess and train balance in stroke patients via robotic devices developed from BALANCE research. The project also significantly contributed to various spin-off initiatives, including the European Network on Wearable Robots (https://wearablerobots.eu) safety standards under the International Organization for Standardization and the International Electrotechnical Commission for personal care and medical applications of exoskeletons and the establishment of a benchmarking network (www.benchmarkinglocomotion.org) in Europe.

“Concrete steps towards commercialisation together with patents have been obtained for three solutions—the magnetic-immune motion capturing suit, the algorithms to measure quality-of-balance in real-time, and BAR for balance assessment and training in stroke rehab,” explains Dr. Veneman. “Now the project has finished, every partner will proceed with development of their own contributions to the BALANCE project.”

Dr. Veneman's view of the future for robotics in this rapidly expanding area is that “The ultimate goal is to have the exoskeleton seamlessly cooperate with the human user.”