Show simple item record

dc.contributor.authorJaramillo Cienfuegos, Paolaen_US
dc.date.accessioned2017-07-30T06:00:16Z
dc.date.available2017-07-30T06:00:16Z
dc.date.issued2016-02-05en_US
dc.identifier.othervt_gsexam:6706en_US
dc.identifier.urihttp://hdl.handle.net/10919/78471
dc.description.abstractA promising approach to treat patients with vocal fold paralysis using electrical stimulation is investigated throughout this research work. Functional Electrical Stimulation works by stimulating the atrophied muscle or group of muscles directly by current when the transmission lines between the central nervous system are disrupted. This technique helps maintain muscle mass and promote blood flow in the absence of a functioning nervous system. The goal of this work is two-fold: develop control techniques for muscle contraction to optimize muscle stimulation and develop a small-scale electromagnetic system to provide stimulation to the laryngeal muscles for patients with vocal fold paralysis. These studies; therefore, focus on assessing a linear Proportional-Integral (PI) controller and two nonlinear controllers: Model Reference Adaptive Controller (MRAC) and an Adaptive Augmented PI (ADP-PI) system to identify the most appropriate controller providing effective stimulation of the muscle. Direct stimulation is applied to mouse skeletal muscle in vitro to test the controllers along with numerical simulations for validation of these experimental tests. The experiments included muscle contractions following four distinct trajectories: a step, sine, ramp, and square wave. Overall, the closed-loop controllers followed the stimulation trajectories set for all the simulated and tested muscles. When comparing the experimental outcomes of each controller, we concluded that the ADP-PI algorithm provided the best closed-loop performance for speed of convergence and disturbance rejection. Next, the focus of the research work was on the implementation of an electromagnetic system to generate appropriate currents of stimulation using the aforementioned controllers. For this study, Nickel-Titanium shape memory alloys were used to assess activation (contraction) through a two-coil system guided by the controllers. The application of the two-coil system demonstrated the effectiveness of the approach and a main effect was observed between the PI, MRAC, and ADP-PI controllers when following the trajectories. Lastly, a small scale two-coil system is developed for animal testing in the muscle-mass-spring setup. Experiments were successful in generating the appropriate stimulation controlled by the output-based algorithms for muscle contraction. Trials conducted for this study were compared to the muscle contractions observed in the first study. The controllers were able to provide appropriate stimulation to the muscle system to follow the set trajectories: a step, ramp, and sinusoidal input. More trials are required to draw statistical conclusions about the performance of each controller. Regardless, the small-scale two-coil system along with the applied controllers can be reconfigured to be an implantable system and tested for appropriate stimulation of the laryngeal muscles.en_US
dc.format.mediumETDen_US
dc.publisherVirginia Techen_US
dc.rightsThis Item is protected by copyright and/or related rights. Some uses of this Item may be deemed fair and permitted by law even without permission from the rights holder(s), or the rights holder(s) may have licensed the work for use under certain conditions. For other uses you need to obtain permission from the rights holder(s).en_US
dc.subjectSkeletal Muscleen_US
dc.subjectMuscle Paralysisen_US
dc.subjectFunctional Electrical Stimulationen_US
dc.subjectControl Systemsen_US
dc.subjectAdaptive Controlen_US
dc.subjectNonlinear Systemsen_US
dc.titleClosed Loop Control of Muscle Contraction using Functional Electrical Stimulationen_US
dc.typeDissertationen_US
dc.contributor.departmentMechanical Engineeringen_US
dc.description.degreePh. D.en_US
thesis.degree.namePh. D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineMechanical Engineeringen_US
dc.contributor.committeechairLeonessa, Alexanderen_US
dc.contributor.committeememberAbaid, Nicole Teresaen_US
dc.contributor.committeememberGrange, Robert W.en_US
dc.contributor.committeememberDe Vita, Raffaellaen_US
dc.contributor.committeememberMueller, Rolfen_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record