Success Story: Numerical simulation of exoskeleton

NCC presenting the success story

The Czech National Competence Centre (NCC) for High-Performance Computing (HPC) and Data Analysis (HPDA) is represented by IT4Innovations National Supercomputing Center at VSB – Technical University of Ostrava. Its mission is to analyse, implement, and coordinate all the activities required to offer end users the services they need: from access to supercomputers and technology consulting to providing training for industry, public administration, and academia.

Industrial Organisations Involved:

The MEBSTER is a research & development company and through its cost-effective assistive devices:

• It supports medical care providers to improve and streamline their services for their clients with mobility disorders.
• It aids individual clients with mobility disorders to build healthy habits and motivate them to actively improve their quality of life.

It is an international team of engineers, doctors, and physiotherapists based in the Czech Republic. They are committed to intensively developing innovative assistive technologies and medical devices for rehabilitation spanning over six years. They design their devices directly with users, and their research is solely patient-centred. They rigorously test all products to ensure they are simple and as comfortable as possible. In addition, they collaborate with a team of world experts to set trends in their industry.

Technical/scientific Challenge:

The objective of this proof-of-concept was to demonstrate the use of numerical modelling and simulation in the design process of an innovative UNILEXA exoskeleton for gait assistance designed for people with partial or complete loss of lower limb function.

Business impact:

The UNILEXA exoskeleton is a risk class I medical device. The placing of similar products on the market is subject to strict regulations under a new EU regulation known as the MDR. Each such product must be validated through simulations and tests to verify and guarantee its safety and usability for patients. Testing medical devices are very costly and time-consuming, hence the use of simulations.

Thanks to the detailed numerical simulation, it will be possible to repeatedly ascertain and verify the safety and effectiveness of the existing product and its other versions and variants. In addition, the simulation will help to reveal optimisation opportunities in terms of weight, usability and cost for the production and servicing of the UNILEXA exoskeleton.

The consequence of the use of numerical simulation will be, in particular, an increase in the quality of care provided to the end user with an emphasis on user comfort not only for the client (patient) but also for the medical staff using the technology, as well as an increase in the competitiveness of the product on the market.

Solution:

The computational model is based on the finite element method (FEM). The exoskeleton assembly is simulated with the inclusion of effects resulting in the strength/stiffness of the system. Since the exoskeleton assembly is mathematically a complex nonlinear problem with a wide variation of boundary conditions, the use of HPC is necessary to solve such a complex numerical model.

The ANSYS software was used for the creation of the computational model and numerical simulation. A simplified model of the part of the UNILEXA exoskeleton assembly was created to estimate the required HPC resources. The four nodes of the Barbora system were used to solve a complex numerical model, including nonlinearities such as contact interfaces with friction, large displacements, etc.

Benefits:

• Possibility of verification the safety and effectiveness of the existing product and its further versions and variants;
• Increase in the quality of care provided to the end user with an emphasis on user´s comfort;
• Increase in the competitiveness of the product on the market.