Dissertations and Theses
Date of Award
2025
Document Type
Thesis
Department
Mechanical Engineering
First Advisor
Inigo Sanz-Pena
Keywords
wearable assistive robots, human-robot interface, artificial ligament, knee biomechanics, force sensing, cuff system, lattice structures, topology optimization
Abstract
Comfort is among the main priorities when designing a wearable assistive device that needs to be used for long sessions. There is a growing need for wearable systems that provide aid to patients with an injured knee. In addition, there has been an effort to incorporate cable-driven designs rather than rigid attachments. This change in design decreases the overall weight of the system and can allow the cable to adapt to a user’s change in gait patterns. This thesis investigates a cuff system centered around the knee and the design of a testing rig. This system incorporates elements from pre-existing rigid and soft exosuits to form a hybrid design. The aim of the study is to improve user comfort and design a cuff system for wearable ankle assistive devices. A testing rig that allows force tracking at different angles has also been created as part of this thesis. The device features 2 pairs of cuffs; one that's placed above the knee and another that's placed below the knee. Each pair of cuffs comes equipped with a BOA lacing system to secure them around the user. A lattice design was incorporated in the inner surface of each part of the system. The lattice has been designed using FEA and topology optimization methods using computational tools, which were used to change the strut diameter based on the magnitude of stress experienced at a particular region. Artificial ligaments analogous to biological knee ligaments have been created as well. The purpose of the cuff system for wearable ankle assistive devices is to manipulate the force distribution along the human-robot interface by reducing the amount of high pressure points. This reduction in pressure can potentially make the system more comfortable to wear for the user if the design fulfills its purpose. A rig to test out the force capabilities of the cuff system at different angles has also been designed. The rig comes equipped with a tension load cell and 6 force sensitive resistors (FSRs) to measure the pressure distribution changes over the human leg when assistive forces are applied. Powered by a step motor, the rig makes use of a lead screw to translate rotational motion into linear translation. Overall, a cuff system and testing rig have been designed and fabricated. Some future work to consider includes evaluating wearable ankle robots at the human-robot interface level before moving on to human subjects, making use of the motor built into one of the cuffs, and improving the BOA lacing design to further increase comfort. These aspects can lead to safer designs and processes when developing these devices. If properly implemented, this design can pave the way for creating a more comfortable experience for the user in the world of wearable assistive robots.
Recommended Citation
Cejovic, Adifet, "A Study Exploring the Use of Artificial Ligaments to Enhance the Human-Robot Interface Via Force Distribution Manipulation in Biomimetic Cuff Systems" (2025). CUNY Academic Works.
https://academicworks.cuny.edu/cc_etds_theses/1241
