Methodology for the design of passive, structure-optimized orthoses for the treatment or compensation of pathophysiological movement patterns using musculoskeletal human models

• Applicants: Dr.-Ing. Jörg Miehling; Professor Dr.-Ing. Sandro Wartzack
• Subject Area: Automation, Mechatronics, Control Systems, Intelligent Technical Systems, Robotics ; Engineering Design, Machine Elements, Product Development
• Term: since 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 450307023

Ankle joint orthoses are the most common rehabilitation device used to treat pathophysiological gait patterns such as foot drop syndrome. For this purpose, passive orthoses are preferably used which enable a supporting or stabilizing function or even the support of a rotational direction of the joint with spring-damper systems. In the case of extensive paresis or paralysis of the lower leg musculature, active orthoses can be used to restore a healthy gait. With the appropriate actuators, these can support both directions of rotation of the joint. The use of active orthoses, however, is accompanied by many problems, such as their high weight, the less integral design and the complex control and power supply of the actuators. For this reason, a methodology is to be developed within the framework of the research project with which the design of passive ankle joint orthoses can be realized to support both directions of joint rotation. For this purpose, the orthosis is to be provided with suitable fibre-reinforced plastic lightweight structures which, in the event of elastic deformation, exhibit the structural response corresponding to the required support of the pathophysiological gait. The core objective of the research project is the development of a method which enables the structures to be designed in such a way that their structural response is in symbiosis with the patient's gait behaviour and thus enables the best possible treatment or compensation of the patient's disease. To this end, a coupling between an FE model for structural optimization and a musculoskeletal human model for mapping the physiological and pathophysiological gait is to be introduced. The orthosis design optimized with the help of the developed methodology is finally manufactured as a prototype and evaluated on the basis of a test set-up before the orthosis can be tested in practical trials in conjunction with patients.

• DFG Programme: Research Grants