Motion Therapy Devices based on Rotary Soft Fluidic Actuators - Concept and Proto- typing

The paper describes a concept of innovative assistive motion therapy devices with new patent pending fluidic actuators. The main novelty of these soft actuators is the rotary fluid motor with elastic chambers (REC), which produces rotational motion without any additional transmission elements. The key actuator features as inherent compliance, high back-driveability and light-weight design build a foundation for safe physical human-machine interaction, although torques of several tens of Newton-meter can be generated. Due to their compact design the REC-actuators demonstrate better integration capabilities into motion therapy devices than conventional fluidic muscles of linear type. The actuator compliance can be varied by pressure regulation, which makes soft fluidic actuators very suitable for making the transition from continuous passive motion to active (assistive) behaviour during the therapy depending on a patient activity. The design concept and key aspects of a patient-centred control strategy have been tested on the basis of lower limb device.