Biomedical Engineering and Bioengineering Commons^™

Virtual Reality Simulation Of Glenoid Reaming Procedure, Mohammadreza Faieghi

Electronic Thesis and Dissertation Repository

Glenoid reaming is a bone machining operation in Total Shoulder Arthroplasty (TSA) in which the glenoid bone is resurfaced to make intimate contact with implant undersurface. While this step is crucial for the longevity of TSA, many surgeons find it technically challenging. With the recent advances in Virtual Reality (VR) simulations, it has become possible to realistically replicate complicated operations without any need for patients or cadavers, and at the same time, provide quantitative feedback to improve surgeons' psycho-motor skills. In light of these advantages, the current thesis intends to develop tools and methods required for construction of a VR …

Acromial Insufficiency Fractures In Reverse Total Shoulder Arthroplasty: A Biomechanical Study, Alicia Kerrigan

Electronic Thesis and Dissertation Repository

Reverse total shoulder arthroplasty (RTSA) is increasingly utilized in the aging population, with a growing list of surgical indications including rotator cuff tear arthropathy, proximal humerus fractures, and revision arthroplasty. Acromial insufficiency fractures following RTSA are poorly understood, difficult to diagnose, and associated with inferior clinical outcomes. There is limited knowledge in the literature regarding the etiology of post-operative acromial fractures. The purpose of this study is to evaluate the role of implant parameters on acromial strain following RTSA.

Using a cadaveric model, a custom designed modular RTSA system was implanted that allowed for evaluation of modifiable parameters including glenoid …

Tibiotalar Arthrodesis: Development Of A Novel Jig And Alignment Guide, Adam Mathew Ropchan

Electronic Thesis and Dissertation Repository

Tibiotalar arthrodesis is a surgical procedure, used for the treatment of end-stage ankle arthrosis and instability. There are dozens of described procedures in the literature, all with varying rates of success. Two of the most common reasons for reoperation in tibiotalar arthrodesis are nonunion and infection; few studies have established any associations between patient/surgical factors and reoperation for nonunion and infection.

The first part of this thesis focuses on determining the rate of reoperation to the ipsilateral lower limb and if any patient/surgical factors are associated with reoperation for nonunion and infection. The second part of this thesis turns attention …

Investigation And Validation Of Imaging Techniques For Mitral Valve Disease Diagnosis And Intervention, Claire Vannelli

Electronic Thesis and Dissertation Repository

Mitral Valve Disease (MVD) describes a variety of pathologies that result in regurgitation of blood during the systolic phase of the cardiac cycle. Decisions in valvular disease management rely heavily on non-invasive imaging. Transesophageal echocardiography (TEE) is widely recognized as the key evaluation technique where backflow of high velocity blood can be visualized under Doppler. In most cases, TEE imaging is adequate for identifying mitral valve pathology, though the modality is often limited from signal dropout, artifacts and a restricted field of view. Quantitative analysis is an integral part of the overall assessment of valve morphology and gives objective evidence …

Experimental Determination Of Motion Parameters And Path Forces Of Robot-Driven Glenoid Reaming Procedure, Mayank Sharma

Electronic Thesis and Dissertation Repository

Glenoid reaming is one of the most challenging milestones of the total shoulder arthroplasty (TSA) procedure. For a successful TSA, adequate bone resurfacing is required to ensure a well-conformed positioning of the implant onto the native bone.

In this study, a light-weight robot was employed to assert a prescribed thrust-force and reaming depth to mimic clinical practice. Reaming of bone-analogs indicated that specimen density had a linear relationship with reamer velocity and apparent machining stiffness. Human cadaveric bone studies confirmed a linear relationship between specimen density and reamer velocity in both subchondral and cancellous regions of the glenoid. A reaming …

Development Of Granulation Tissue Mimetic Scaffolds For Skin Healing, Adam Hopfgartner

Electronic Thesis and Dissertation Repository

Impaired skin healing is a significant and growing clinical concern, particularly in relation to diabetes, venous insufficiency and immobility. Previously, we developed electrospun scaffolds for the delivery of periostin (POSTN) and connective tissue growth factor 2 (CCN2), matricellular proteins involved in the proliferative phase of healing. This study aimed to design and validate a novel electrosprayed coaxial microsphere for the encapsulation of fibroblast growth factor 9 (FGF9), as a component of the POSTN/CCN2 scaffold, to promote angiogenic stability during wound healing. For the first time, we observed a pro-proliferative effect of FGF9 on human dermal fibroblasts (HDF) in vitro, indicating …

A Biomechanical And Physiological Signal Monitoring System For Four Degrees Of Upper Limb Movement, Allison R. Goldman

Electronic Thesis and Dissertation Repository

A lack of adherence to prescribed physical therapy regimens in improper healing results in poor outcomes for those affected by musculoskeletal disorders (MSDs) of the upper limb. Societal and psychological barriers to proper adherence can be addressed through the system presented in this work consisting of the following components: an ambulatory biosignal acquisition sleeve, an electromyography (EMG) based motion repetition detection algorithm, and the design of a compatible capacitive EMG acquisition module.

The biosignal acquisition sleeve was untethered, unobtrusive to motion, contained only modular components, and collected biomechanical and physiological sensor data to form full motion profiles of the following …

Electrospun Collagen Fibers For Tissue Regeneration Applications, Ying Li

Electronic Thesis and Dissertation Repository

Tissue engineering aims to regenerate damaged and deceased tissue by combining cells with scaffold made from an appropriate biomaterial and providing a conducive environment to guide cell growth and the formation or regeneration of new tissue or organ. While collagen, an important material of the extracellular matrix (ECM), is a natural choice as a scaffold biomaterial, the conducive environment can only be created by having the ability to control the geometry, organization, structural and mechanical properties of the scaffold. Moreover, degradability and degradation rate control of the scaffold has to be taken into consideration too. In this work, we aim …

Dynamic Calibration Of Emg Signals For Control Of A Wearable Elbow Brace, Taylor Stanbury

Electronic Thesis and Dissertation Repository

Musculoskeletal injuries can severely inhibit performance of activities of daily living. In order to regain function, rehabilitation is often required. Assistive devices for use in rehabilitation are an avenue explored to increase arm mobility by guiding therapeutic exercises or assisting with motion. Electromyography (EMG), which are the muscle activity signals, may be able to provide an intuitive interface between the patient and the device if appropriate classification models allow smart systems to relate these signals to the desired device motion.

Unfortunately, there is a gap in the accuracy of pattern recognition models classifying motion in constrained laboratory environments, and large …

Development Of Image-Based Surgical Planning Software For Bone-Conduction Implants, Carlos D. Salgado

Electronic Thesis and Dissertation Repository

The BONEBRIDGE bone-conduction device is used to treat conductive and mixed hearing losses. The size of its floating mass transducer (FMT) can preclude implantation in certain anatomies, necessitating comprehensive surgical planning. Current techniques are time consuming and difficult to transfer to the operating room. The objective of this thesis was to develop software for calculating skull thickness to the dura mater to find locations for the FMT and to the first air cells which guarantee sufficient bone for the implant screws to grasp. Temporal bone computed tomography (CT) images were segmented and processed and custom Matlab code was written to …

Evaluating Devices For The Measurement Of Auditory-Evoked Fetal Movement, Patrick Gatutsi

Electronic Thesis and Dissertation Repository

Determining normal and abnormal fetal function in utero in order to better predict which fetuses are at risk for adverse outcome is critical. However, the medical imaging tools that could assist with diagnosis are very expensive and rarely available in the developing world. In this study, we developed a prototype audio-motio-tachograph (AMTG), which measures fetal movements through the recording of abdominal wall deformations and tested it in Rwanda. First, we showed that AMTG detected fetal signals and that fetuses respond to complex acoustic stimuli. In order to improve the sensitivity of the device, we then measured whole abdominal wall deformations …

Development And Validation Of A Probe Tube Placement Training Simulator, Robert Koch

Electronic Thesis and Dissertation Repository

For over 90% of individuals with hearing loss, hearing aids are the primary method of treatment. Recent studies have shown that most hearing aids are not personalized properly to patients, resulting in poor hearing outcomes. Poor training methods has been proposed as a possible reason for these findings.

A training simulator was developed consisting of a mannequin head with flexible, anatomically correct ears, and an optical tracking system for tracking the insertion of diagnostic equipment into a 3D printed ear canal. The simulator provides an outlet for trainees to practice their clinical procedures while receiving validated feedback, without the need …

Engineering Graphene Oxide-Based Nanostructures For Dna Sensors, Aditya Balaji

Electronic Thesis and Dissertation Repository

Various nanostructures have been explored in DNA biosensors to convert the hybridization of DNA sequences to easily measurable processes, including optical, mechanical, magnetic, or electrochemical process. In this thesis, graphene oxide, a two-dimensional nanostructure, is applied in quenching the fluorescence of a core-shell nanoparticles modified with targeted DNA sequences. The core-shell nanoparticles, iron oxide (Fe₃O₄) core, and fluorescent silica (SiO₂) shell, were produced through a wet chemical process which can directly link to a targeted DNA sequence (DNA-t), and the graphene oxide nanosheets were produced by the oxidation of graphite. In the meantime, …

Preparation And Characterization Of Electrospun Rgo-Poly(Ester Amide) Tissue Engineering Scaffolds, Hilary Stone

Electronic Thesis and Dissertation Repository

Tissue engineering scaffolds should support tissue maturation through exposure to biologically relevant stimuli and through successful cell infiltration. External electrical stimulation is particularly relevant for cardiac and neural applications, and requires conductive scaffolds to propagate electrical signals; cell infiltration is only possible with scaffolds that have sufficient porosity. The aim of this study was to impart conductivity and increased porosity of electrospun poly(ester amide) (PEA) scaffolds. Reduced graphene oxide (rGO) was incorporated into blend PEA and coaxial PEA-chitosan fibrous scaffolds, which increased scaffold conductivity and supported cardiac differentiation. The novel combination of ultrasonication and leaching of a sacrificial polymer was …

The Development Of A Temporomandibular Force Simulator To Study Craniofacial Strain In-Vitro, Kenneth Kc Ip

Electronic Thesis and Dissertation Repository

An in-vitro musculoskeletal loading simulator was developed to replicate the internal forces of mastication, and then employed in a comparison of clinically relevant facial fracture repairs. Muscle forces are simulated by pneumatic pistons via 3D printed mounts that are reverse-engineered from CT scan to match muscle attachment sites, which are adhered to bone in order to simulate native stress distributions. Bite force and bone strain pattern of the craniofacial structure under load were measured using a force sensor and strain gauges respectively. In a series of five fresh-frozen cadaveric heads, it was found that strain patterns of the craniofacial structure …

Process Analytics From Passive Acoustic Emissions Monitoring During Fluidized Bed Pellet Coating In Pharmaceutical Manufacturing, Allan Carter

Electronic Thesis and Dissertation Repository

Piezoelectric microphones were attached to a top spray fluidized bed to provide valuable process signatures. Relationships were developed between sound waves and conditions within the fluidized bed to relay critical quality and performance information. Deep learning analytics were used to extract valuable information from experimental data. Advancements in passive acoustic emissions monitoring will play a key role in optimizing pharmaceutical manufacturing pathways to ensure drug quality and performance.

An In-Silico Assessment Of Stemless Shoulder Arthroplasty: From Ct To Predicted Bone Response, Jacob M. Reeves

Electronic Thesis and Dissertation Repository

Despite the emergence of stemless humeral implants that utilize short fixation features to gain purchase solely in the metaphysis, the literature contains little information regardingthe morphology and mechanical properties of the humerus’ proximal trabecular-canal, and how stemless implants impact bone response. The present work employs in-silicotools, including CT-based and Finite Element (FE) methods, to define parameters that may influence stemless implant design.

The density and morphology of the proximal humerus were assessed using CT-derived point clouds of the trabecular-canal. Bone density was found to diminish 15-20mm beneath the humeral head resection and was greater peripherally. The depth, path and bounding …

The Effect Of Implant Girth And Implant Collar On The Degree Of Bone To Implant Contact And Bone Stresses In The Proximal Humerus, Stephanie Synnott

Electronic Thesis and Dissertation Repository

Stem design is a crucial element for the success of shoulder prostheses. Various components of stem design have been investigated; however, little research has been conducted on the effects of (1) implant girth and (2) an implant collar on load transfer. A generic implant model was designed and employed in a (FE) model to determine 3 outcome measures: changes in the degree of bone to implant contact (BIC), changes in cortical and trabecular bone stresses from the intact state, and changes in cortical and trabecular strain energy densities (SED). The variables examined were (1) implant girth (small, medium [generic base …

A Numerical Investigation Of Human Cough Jet Development And Droplet Dispersion, Ran Bi

Electronic Thesis and Dissertation Repository

As part of the Western Cold and Flu aerosol (WeCoF) studies, the present study provides Computational Fluid Dynamics (CFD) modelling of human cough flow. The cough flow is characterized in two different aspects, the flow field and the droplets. In the study of the flow field of coughing, various dynamic characteristics, including the velocity variation, streamwise penetration and power spectral density, are examined. CFD simulations using two different approaches, the unsteady Reynolds Averaged Navier-Stokes (URANS) and the large eddy simulation (LES), are performed for comparison purposes. The numerical results are validated by the experimental data obtained from the measurements by …

Examining Reverse Total Shoulder Arthroplasty Baseplate Fixation In Patients With E2-Type Glenoid Erosion, Matthew D. Mahaffy

Electronic Thesis and Dissertation Repository

Superior glenoid erosion of the shoulder joint is a result of humeral subluxation caused by rotator cuff tears, and can be addressed using implants, specifically reverse total shoulder arthroplasty. This thesis examined the regional variations of bone present in superiorly eroded glenoids, established a baseline for regular RTSA baseplate fixation in patients with this defect, and compared the effect of geometric baseplate differences on implant fixation. The superiorly eroded glenoids demonstrated similar regional bone density variations as normal glenoids, and the superior and inferior regions of the glenoid demonstrated the densest and least dense cancellous bone, respectively. These regions also …

Ultrasound-Augmented Laparoscopy, Uditha Lakmal Jayarathne

Electronic Thesis and Dissertation Repository

Laparoscopic surgery is perhaps the most common minimally invasive procedure for many diseases in the abdomen. Since the laparoscopic camera provides only the surface view of the internal organs, in many procedures, surgeons use laparoscopic ultrasound (LUS) to visualize deep-seated surgical targets. Conventionally, the 2D LUS image is visualized in a display spatially separate from that displays the laparoscopic video. Therefore, reasoning about the geometry of hidden targets requires mentally solving the spatial alignment, and resolving the modality differences, which is cognitively very challenging. Moreover, the mental representation of hidden targets in space acquired through such cognitive medication may be …

Augmented Reality Ultrasound Guidance In Anesthesiology, Golafsoun Ameri

Electronic Thesis and Dissertation Repository

Real-time ultrasound has become a mainstay in many image-guided interventions and increasingly popular in several percutaneous procedures in anesthesiology. One of the main constraints of ultrasound-guided needle interventions is identifying and distinguishing the needle tip from needle shaft in the image. Augmented reality (AR) environments have been employed to address challenges surrounding surgical tool visualization, navigation, and positioning in many image-guided interventions. The motivation behind this work was to explore the feasibility and utility of such visualization techniques in anesthesiology to address some of the specific limitations of ultrasound-guided needle interventions. This thesis brings together the goals, guidelines, and best …

Covalently Crosslinked Organic/Inorganic Hybrid Biomaterials For Bone Tissue Engineering Applications, Dibakar Mondal

Electronic Thesis and Dissertation Repository

Scaffolds are key components for bone tissue engineering and regeneration. They guide new bone formation by mimicking bone extracellular matrix for cell recruitment and proliferation. Ideally, scaffolds for bone tissue engineering need to be osteoconductive, osteoinductive, porous, degradable and mechanically competent. As a single material can not provide all these requirements, composites of several biomaterials are viable solutions to combine various properties. However, conventional composites fail to fulfil these requirements due to their distinct phases at the microscopic level. Organic/inorganic (O/I) class II hybrid biomaterials, where the organic and inorganic phases are chemically crosslinked on a molecular scale, hence the …

The Kinematic And Biomechanical Effects Of Bracing On The Rehabilitation Of The Lcl Injured Elbow, Sara M. Banayan

Electronic Thesis and Dissertation Repository

Lateral collateral ligament (LCL) injuries are often treated non-operatively or with surgical repair. If instability persists, hinged elbow orthoses (HEOs) are often recommended. However, these orthoses are designed as a straight hinge, which does not account for the native carrying angle of the elbow. A custom HEO was designed to adjust the orthosis valgus angulation to measure in vitro elbow kinematics and biomechanics. An in vitro study investigated the effect of HEO valgus angulation during simulated active and passive flexion, in the vertical dependent and varus positions, with the forearm pronated and supinated. In the vertical dependent position, the orthosis …

Multi-Channel Mr Phase Image Processing For Non-Contrast Tissue Characterization, Zahra Hosseini

Electronic Thesis and Dissertation Repository

Magnetic resonance imaging (MRI) enables tissue characterization using the intrinsic tissue properties. By manipulating a number of imaging parameters different image contrasts can be achieved. Multi-echo gradient recalled echo (ME-GRE) enables acquisition of two distinct images, magnitude and phase, in a relatively short time. Phase image, specifically, contains a wealth of information for generation of quantitative maps, with the local tissue susceptibility differences as a source of contrast. GRE imaging is sensitive to field-inhomogeneities. This challenge presents more strongly in multi-channel acquisition, where the coil sensitivity variations impose complications in extracting information from the underlying anatomy. This calls for a …

Automatic Brain Tumor Segmentation By Deep Convolutional Networks And Graph Cuts, Zhenyi Wang

Electronic Thesis and Dissertation Repository

Brain tumor segmentation in magnetic resonance imaging (MRI) is helpful for diagnostics, growth rate prediction, tumor volume measurements and treatment planning of brain tumor. The difficulties for brain tumor segmentation are mainly due to high variation of brain tumors in size, shape, regularity, location, and their heterogeneous appearance (e.g., contrast, intensity and texture variation for different tumors). Due to recent advances in deep convolutional neural networks for semantic image segmentation, automatic brain tumor segmentation is a promising research direction.

This thesis investigates automatic brain tumor segmentation by combining deep convolutional neural network with regularization by a graph cut. We investigate …

Development Of Force-Space Navigation For Surgical Robotics, Corey Daniel Smith

Electronic Thesis and Dissertation Repository

Surgical robotics have been used for many years in orthopaedic procedures in the hip and knee. Robots tend to offer high accuracy and repeatability but add increased cost, complexity, time, and workflow disruption. This work outlines the design and development of a surgical robot that navigates using force feedback. Flexible components tether the patient to the robot and reaction loads are measured allowing the robot to “feel” its way around the pre-operative plan. Differences calculated between measured and desired loads are converted to Cartesian corrections that the robot used to navigate. The robot was tested first using simple square paths …

Embedded Smart-Polymer Sensor Arrays For Elucidating Load Distributions In Orthopaedic Implants, Carolina Micolini

Electronic Thesis and Dissertation Repository

The long-term outcomes of orthopaedic joint implants are only beginning to be understood, making it imperative to monitor the contact loads across the entire implant interface. This capability will elucidate the force transmission and distribution mechanisms exhibited by these implants in-service over time. This study explores the design and implementation of 3D-printed smart-polymer force sensor arrays, consisting of piezoresistive polyaniline (PANI) structures embedded within a polymeric parent phase. This unique multi-material additive manufacturing process was then employed to realize transducers embedded in the humeral component of a replacement prosthetic device conventionally used to restore the functionality of the shoulder joint. …