Dissertation Title: Embodiment of an osseointegrated knee prosthesis with agile myoneural control

Abstract: 

There exist major discrepancies between intact and amputated physiology that manifest in persons possessing the latter as pathological health conditions and a disrupted sense of embodiment. With the emergence of bionic interfaces that can more tightly couple with human physiology, there is an urgent need to characterize the compounded errors induced by these discrepancies before neurorobotic prostheses can be of maximal aid to clinical rehabilitation. Through this work, I provide a foundational perspective on amputation interventions and control signal extraction methodologies in the context of neurorobotic control at the transfemoral level.

The first part of this dissertation explores the neurophysiological and neuromechanical outcomes of a surgical transfemoral amputation revision that restores agonist-antagonist muscle dynamics. To investigate, I undertake a within-subjects study to quantify changes in muscular function, cortical activity, and neurorobotic control performance as a result of the intervention. Through these data, I provide evidence that extant amputated musculature can be modified to restore functionality for the purpose of efferent neurorobotic control.

The second part of this dissertation explores a combined implementation of the previous surgical intervention with an osseointegrated transfemoral implant that allows for direct skeletal loading and chronic interactions between the internal residuum and external environment. To investigate, I assess the clinical outcomes of the novel transfemoral platform with implanted intramuscular electrodes in two subjects. Specifically, the outcomes of the operation are quantified through biophysical measurements and measurements of the stability of the implanted hardware to suggest each subject’s potential for bidirectional neurorobotic interfacing.

The third part of this dissertation compares the influence of various muscle architectures, physical interfacing configurations, and control signal extraction methodologies on the ability to produce physiological neurorobotic knee dynamics. The two aforementioned subjects with novel transfemoral platform are compared to other amputee cohorts without individual aspects of the platform, showcasing unprecedented agility and sustainment of prosthetic embodiment in the process.

Committee members: 

Prof. Hugh Herr, Media Arts and Sciences, MIT
Prof. Rickard Brånemark, Department of Orthopaedics, Gothenburg University
Prof. Nidhi Seethapathi, Brain & Cognitive Sciences and Electrical Engineering and Computer Science, MIT