Design of a passive hydraulic simulator for abnormal muscle behavior replication

Spasticity and rigidity are two abnormal hypertonic muscle behaviors commonly observed in passive joint flexion and extension evaluation. Clinical evaluation for spasticity and rigidity is done through in-person assessment using qualitative scales. Due to the subjective nature of this evaluation method, diagnostic results produced from these clinical assessments can have poor reliability and inconsistency. Incorrect diagnosis and treatment often result in worsening of the abnormal muscle behaviors, reducing the quality of life and leading to an increased cost of healthcare. Several programmable, robotic simulators had been developed to improve the accuracy of clinical evaluation by providing clinician practical training opportunities; however none of these training devices are commercially available due to technical and manufacturing limitations. For this reason, a novel, purely mechanical, hydraulic-based simulator design was proposed as an alternative approach to abnormal muscle behavior simulation. The original goal of the project presented in this thesis was to address both spasticity and rigidity in the elbow joint during flexion; however due to time constraints, the initial prototype can only mimic spasticity. The hydraulic-based simulator utilized a novel damper design using viscous fluid in combination with creative flow channel configurations to replicate different levels of spasticity behaviors depicted on a qualitative scale. The simulator was capable of generating a wide range of speed-dependent force feedbacks without need for any computational controls. Preliminary results obtained from evaluating the simulator suggested the possibility of using this novel design in replicating the speed-dependent characteristics of spasticity. The framework and method implemented in the current simulator prototype could be further developed and expanded to replicate spasticity or other types of abnormal behaviors, such as rigidity, in various human joints (not limiting the design to just the elbow joint).

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2016

Author dc:creator

• Liang, Jiahui

Contributors dc:contributor

• Hsiao-Wecksler, Elizabeth T.
• Ewoldt, Randy H.

• spasticity
• rigidity
• passive
• hydraulic
• viscous flow
• damper
• simulator
• simulation
• abnormal muscle behavior

Statement dc:rights

• Copyright 2016 Jiahui Liang

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/92848

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/92848