Dissertation
Design and Modeling of a PneuSMA Soft Robotic Catheter Device Using Resistance-Based Modeling of Nitinol Springs
Washington State University
Doctor of Philosophy (PhD), Washington State University
01/2022
DOI:
https://doi.org/10.7273/000004591
Handle:
https://hdl.handle.net/2376/124752
Abstract
The soft robotics paradigm involves constructing robots out of soft materials to improve their safety and ability to interact with humans and delicate objects. Much research has been devoted to this emerging field in recent years as soft robotic devices lend themselves to a variety of applications ranging from wearable rehabilitation devices to biomimetics.
Soft, flexible devices show particular promise for medical applications where the ability to perform snake-like manipulations with soft devices could radically improve the safety and effectiveness of endoscopic and intravenous procedures. Where traditional catheter devices for these procedures can only be steered at the tip, there exists a need for more maneuverable devices with a high number of degrees of freedom (DOF) that can be controlled throughout the entire length. These devices would be capable of traversing sharp bends and branches, enabling access to more remote locations while reducing stress on surrounding tissue.
Recent efforts have focused primarily on pneumatic- and tendon-driven designs for flexible catheter devices. While these methods offer excellent maneuverability, they require complicated networks of tendons or supply tubes to accommodate individual control of each DOF in each series segment. In this dissertation, a hybrid pneumatic/shape-memory alloy (PneuSMA) actuation strategy is proposed for a flexible catheter device. The PneuSMA actuator is capable of multi-directional bending without requiring separate tendons or pneumatic chambers for each series segment.
The PneuSMA actuator design and fabrication method are explained, and a quasi-static analytical model is developed to predict the configuration of the device based on the input pressure and shape-memory alloy (SMA) activation. The PneuSMA analytical model relies on a resistance-based mechanical model for the SMA springs which is developed in this work. The resistance-based nitinol spring model can easily be applied more broadly to other SMA-actuated devices, and experimental results show good agreement between the predicted and experimental curvatures in a single pneuSMA actuator segment, indicating potential for precise control of the PneuSMA catheter device.
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Details
- Title
- Design and Modeling of a PneuSMA Soft Robotic Catheter Device Using Resistance-Based Modeling of Nitinol Springs
- Creators
- Emily Ann Allen
- Contributors
- John P Swensen (Advisor)Arda Gozen (Committee Member)Ming Luo (Committee Member)Narasimha Boddeti (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Mechanical and Materials Engineering, School of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 207
- Identifiers
- OCLC#: 1365767176; 99900898939101842
- Language
- English
- Resource Type
- Dissertation