Theses and Dissertations
This collection includes both ASU Theses and Dissertations, submitted by graduate students, and the Barrett, Honors College theses submitted by undergraduate students.
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- All Subjects: robotics
- Creators: Honeycutt, Claire
Description
According to the Center for Disease Control and Prevention report around 29,668 United States residents aged greater than 65 years had died as a result of a fall in 2016. Other injuries like wrist fractures, hip fractures, and head injuries occur as a result of a fall. Certain groups of people are more prone to experience falls than others, one of which being individuals with stroke. The two most common issues with individuals with strokes are ankle weakness and foot drop, both of which contribute to falls. To mitigate this issue, the most popular clinical remedy given to these users is thermoplastic Ankle Foot Orthosis. These AFO's help improving gait velocity, stride length, and cadence. However, studies have shown that a continuous restraint on the ankle harms the compensatory stepping response and forward propulsion. It has been shown in previous studies that compensatory stepping and forward propulsion are crucial for the user's ability to recover from postural perturbations. Hence, there is a need for active devices that can supply a plantarflexion during the push-off and dorsiflexion during the swing phase of gait. Although advancements in the orthotic research have shown major improvements in supporting the ankle joint for rehabilitation, there is a lack of available active devices that can help impaired users in daily activities. In this study, our primary focus is to build an unobtrusive, cost-effective, and easy to wear active device for gait rehabilitation and fall prevention in individuals who are at risk. The device will be using a double-acting cylinder that can be easily incorporated into the user's footwear using a novel custom-designed powered ankle brace. The device will use Inertial Measurement Units to measure kinematic parameters of the lower body and a custom control algorithm to actuate the device based on the measurements. The study can be used to advance the field of gait assistance, rehabilitation, and potentially fall prevention of individuals with lower-limb impairments through the use of Active Ankle Foot Orthosis.
ContributorsRay, Sambarta (Author) / Honeycutt, Claire (Thesis advisor) / Dasarathy, Gautam (Thesis advisor) / Redkar, Sangram (Committee member) / Jayasuriya, Suren (Committee member) / Arizona State University (Publisher)
Created2020
Description
This research seeks to present the design and testing of exoskeletons capable of assisting with walking gait, squatting, and fall prevention activities. The dissertation introduces wearable
robotics and exoskeletons and then progresses into specific applications and developments in the
targeted field. Following the introduction, chapters present and discuss different wearable
exoskeletons built to address known issues with workers and individuals with increased risk of fall.
The presentation is concluded by an overall analysis of the resulting developments and identifying
future work in the field.
ContributorsOlson, Jason Stewart (Author) / Redkar, Sangram (Thesis advisor) / Sugar, Thomas (Committee member) / Honeycutt, Claire (Committee member) / Arizona State University (Publisher)
Created2021
Description
Mechanical impedance is a concept that is used to model biomechanical propertiesof human joints. These models can then be utilized to provide insight into the inner
workings of the human neuromuscular system or to provide insight into how to best
design controllers for robotic applications that either attempt to mimic capabilities of
the human neuromuscular system or physically interact with it. To further elucidate
patterns and properties of how the human neuromuscular system modulates mechanical
impedance at the human ankle joint, multiple studies were conducted. The first
study was to assess the ability of linear regression models to characterize the change
in stiffness - a component of mechanical impedance - seen at the human ankle during
the stance phase of walking in the Dorsiflexion-Plantarflexion (DP) direction. A
collection of biomechanical variables were used as input variables. The R^2 value of
the best performing model was 0.71. The second and third studies were performed to
showcase the ability of a newly developed twin dual-axis platform, which goes beyond
the limits of a single dual-axis platform, to quantify bilateral stiffness properties. The
second study quantified the bilateral mechanical stiffness of the human ankle joint
for healthy able-bodied subjects during the stance phase of walking and during quiet
standing in both the DP and inversion-eversion directions. Subjects showed a high
level of subject specific symmetry. Lastly, a similar bilateral ankle characterization
study was conducted on a set of subjects with multiple sclerosis, but only during
quiet standing and in the DP direction. Results showed a high level of discrepancy
between the subject’s most-affected and least-affected limbs with a larger range and
variance than in the healthy population.
ContributorsRussell, Joshua (Author) / Lee, Hyunglae (Thesis advisor) / Honeycutt, Claire (Committee member) / Marvi, Hamid (Committee member) / Arizona State University (Publisher)
Created2022