In this paper, we present the design of a novel ankle rehabilitation robot (ARR), called the Flex-ARR, that employs a compliant parallel kinematic mechanism (PKM) with decoupled degrees of freedom. The Flex-ARR is designed to collocate the biological center of rotation of the ankle with that of the robot’s center of rotation to allow natural ankle motion. While multiple ARR designs exist in the literature as well as commercially, their clinical adoption has been limited because they do not emulate the natural motion of the ankle. The Flex-ARR leverages a unique PKM design that uses compliance to absorb minor misalignments between the center of rotation of the ankle and the robot, thereby allowing natural ankle motion. The compliant PKM also accommodates variations in user foot sizes with minimal adjustments. Furthermore, the Flex-ARR has multiple training modes that allow for both rehabilitation and assessment modalities. This paper provides a review of the literature to identify the key factors that have limited the clinical adoption of existing ARRs. Based on this, functional requirements and design specifications for an ideal ARR are defined. This is used to develop a design strategy, followed by conceptual and detailed design. The final draft of this paper will include performance evaluation and validation based on testing the various modalities of the Flex-ARR on human subjects.


Design of an Ankle Rehab Robot  With a Compliant Parallel Kinematic Mechanism

Division / Sponsors: 
Design Engineering Division and Computers & Information In Engineering Division


Paper Proceedings: https://asmedigitalcollection.asme.org/IDETC-CIE/IDETC-CIE2020/volume/83907

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