Biomedical Engineering and Bioengineering Commons^™

Laparoscopic Image Recovery And Stereo Matching, Wenyao Xia

Electronic Thesis and Dissertation Repository

Laparoscopic imaging can play a significant role in the minimally invasive surgical procedure. However, laparoscopic images often suffer from insufficient and irregular light sources, specular highlight surfaces, and a lack of depth information. These problems can negatively influence the surgeons during surgery, and lead to erroneous visual tracking and potential surgical risks. Thus, developing effective image-processing algorithms for laparoscopic vision recovery and stereo matching is of significant importance. Most related algorithms are effective on nature images, but less effective on laparoscopic images.

The first purpose of this thesis is to restore low-light laparoscopic vision, where an effective image enhancement method …

Motion Intention Estimation Using Semg-Acc Sensor Fusion, Jose Alejandro Lopez

Electronic Thesis and Dissertation Repository

Musculoskeletal injuries can severely impact the ability to produce and control body motion. In order to regain function, rehabilitation is often required. Wearable smart devices are currently under development to provide therapy and assistance for people with impaired arm function. Electromyography (EMG) signals are used as an input to pattern recognition systems to determine intended movements.

However, there is a gap between the accuracy of pattern recognition systems in constrained laboratory settings, and usability when used for detecting dynamic unconstrained movements. Motion factors such as limb position, interaction force, and velocity, are known to have a negative impact on the …

In Vitro Analyses Of The Contributions Of The Hip Capsule To Joint Biomechanics, Emma Donnelly

Electronic Thesis and Dissertation Repository

Optimal management of the hip capsule during arthroscopic surgery has not been established. The impact of incisions made to the capsule during minimally invasive procedures on joint biomechanics, and whether repair provides any benefit, continue to be debated. The effectiveness of capsular repair to restore native kinematics may be insufficient. Therefore, a better understanding of joint behavior during various capsule conditions is needed. A new robotic system was used to analyze the effect of progressive capsulotomy incision and repairs on the behavior of a normal hip within range of motion (ROM) limits with respect to the intact joint. Complete repairs …

Immobilized Jagged1 For Notch3-Specific Differentiation And Phenotype Control Of Vascular Smooth Muscle Cells, Kathleen E. Zohorsky

Electronic Thesis and Dissertation Repository

Notch signaling plays a critical role in regulating vascular morphogenesis. In vascular interventions, the endothelial cells (ECs) are often damaged, and EC-SMC contact is compromised. The objective of this study was to investigate if immobilized Jagged1 can act as an EC-surrogate material to direct and control vascular smooth muscle cell (VSMC) behavior via Notch signaling. It was shown that immobilized Jagged1 induced vascular differentiation of iPSC-derived mesenchymal stem cells and mouse embryonic multipotent cells. Immobilized Jagged1 was insufficient to induce mature contractile markers in coronary artery SMCs; therefore, serum starvation and TGFβ1 treatment were investigated. Although Notch signaling is mechanosensitive …

Feasibility Of Twisted Coiled Polymer Actuators For Use In Upper Limb Wearable Rehabilitation Devices, Brandon P.R. Edmonds

Electronic Thesis and Dissertation Repository

Throughout your lifetime, it is nearly impossible to avoid at least one musculoskeletal condition that requires rehabilitation, and for a world containing billions of people, the costs associated with these conditions have become a huge economic burden. Nevertheless, the scientific community has become increasingly aware of the growing potential for wearable mechatronic systems to assist with upper-limb musculoskeletal rehabilitation; however, one limiting factor to their clinical acceptance lies in the development of actuation solutions. Conventional actuators are rigid and cylindrical in nature, requiring additional features to provide the proper forces, torques, and motion direction, required for human interaction. Another type …

Intensification Of Clostridium Pasteurianum Fermentation Producing N-Butanol From Glycerol Using Microfiltration Cell Recycle, Colin W. Couper

Electronic Thesis and Dissertation Repository

This work demonstrates lab scale intensification of the fermentation of glycerol to 1-butanol using Clostridum pasteurianum, starting with simulation and comparison of different cell recycle arrangements, development of a cell recycle apparatus with an existing bioreactor, and demonstration of fermentation with the final system. Fermentations performed with the completed system showed that the cell recycle system was not significantly inhibitory to fermentation, and achieved a maximum apparent cell dry weight of 3.14g/L and a maximum butanol productivity of 1.16g/Lh.

Development And Validation Of Tools For Improving Intraoperative Implant Assessment With Ultrasound During Gynaecological Brachytherapy, Jessica Robin Rodgers

Electronic Thesis and Dissertation Repository

Treatment of gynaecological cancers often includes a type of conformal radiotherapy, known as brachytherapy, that allows radiation sources to be placed close to or directly into cancerous tissues, tailoring the dose to the local region around tumours and sparing surrounding normal tissues. These sources can be positioned via intracavitary applicators that are placed inside the vagina/uterus or interstitial implants, involving the insertion of multiple needles into the tissue. There is currently no standard imaging modality to visualize these applicators and needles at the time of placement, which would allow for the immediate assessment and refinement of the implant positions. Ultrasound …

An Investigation On The Influences Of Radial Head Hemiarthroplasty Stem Fixation Techniques On Articular Mechanics, Jakub Szmit

Electronic Thesis and Dissertation Repository

Radial head hemiarthroplasty design has been extensively studied with a focus on utilizing the geometrical characteristics of the native radial dish as a guide of implant placement and design. Although implant design has been studied, optimal radial head implant fixation technique remains unknown. This thesis focused on the effect of stem fit on radiocapitellar contact mechanics, using both finite element and experimental bench-top approaches. Additionally, investigation into the impact of varus/valgus malalignment of the radial head in both the native state and following hemiarthroplasty was conducted. It was found that loose fitting a smooth stem axisymmetric radial head implant through …

Deep Reinforcement Learning In Medical Object Detection And Segmentation, Dong Zhang

Electronic Thesis and Dissertation Repository

Medical object detection and segmentation are crucial pre-processing steps in the clinical workflow for diagnosis and therapy planning. Although deep learning methods have achieved considerable performance in this field, they impose several shortcomings, such as computational limitations, sub-optimal parameter optimization, and weak generalization. Deep reinforcement learning as the newest artificial intelligence algorithm has great potential to address the limitation of traditional deep learning methods, as well as obtaining accurate detection and segmentation results. Deep reinforcement learning has a cognitive-like process to propose the area of desirable objects, thereby facilitating accurate object detection and segmentation. In this thesis, we deploy deep …

The Effect Of Joint Alignment After A Wrist Injury On Joint Mechanics And Osteoarthritis Development, Puneet Kaur Ranota

Electronic Thesis and Dissertation Repository

Wrist injuries are common and can lead to the development of post-traumatic osteoarthritis. For example, one major complication after a wrist fracture, is when the fractured bone heals in a mal-aligned position, called malunion. It has been assumed that a malunion after wrist fractures alters joint congruency and mechanics leading to the development of post-traumatic osteoarthritis and poor functional outcomes. It is unclear whether anatomical restoration is a key component for the management of wrist injuries and to limit the progression of post-traumatic osteoarthritis. However, the mechanistic pathways between joint structure (and mal-alignment) and patient outcomes, such as the development …

Development Of Water-Soluble Polyesters For Tissue Engineering Applications, Trent Gordon

Electronic Thesis and Dissertation Repository

The development of tunable polymers has become increasingly important for both tissue engineering and drug delivery. This thesis investigates the development of water-soluble polyesters that contain both natural and synthetic components. These polymers offer tunable chemical structures, as well as functional groups for the conjugation of crosslinking moieties or cell signaling molecules. The first series of polymers was synthesized from poly(ethylene glycol) (PEG) and aspartic acid (Asp) via a titanium catalyzed transesterification method to provide polymers with molar masses of 12 kg/mol. After deprotection, the pendent functional groups of Asp were reacted with methacrylic, maleic, and itaconic anhydride to introduce …

Development And Validation Of Augmented Reality Training Simulator For Ultrasound Guided Percutaneous Renal Access, Yanyu Mu

Electronic Thesis and Dissertation Repository

Percutaneous renal access (PCA) is a critical step in needle-based renal procedures. Traditional PCA training relies on apprenticeship, which raises concerns about patient safety and limits training opportunities. In this thesis, we reviewed simulation-based training for PCA, described the development of a novel augmented reality (AR) simulator for ultrasound (US)-guided PCA, and evaluated its validity and efficacy as a teaching tool.

Our AR simulator allows the user to practice PCA on a silicone phantom using a tracked needle and US probe emulator under the guidance of simulated US on a tablet screen. 6 Expert and 24 novice participants were recruited …

Navigation And Patient Specific Instrumentation In Shoulder Arthroplasty, Joseph Cavanagh

Electronic Thesis and Dissertation Repository

The humeral head osteotomy influences shoulder arthroplasty component height, version and neck shaft angle and therefore outcomes. The purpose of this study is to develop and utilize navigation to execute the osteotomy.

3D printed models were used to develop a navigation technique, and then to execute planned osteotomies. Free hand, fixed angle guide, patient specific guides, and real time navigation osteotomies were completed. The height, neck shaft angle and version were recorded. Also collected, were the planes of the guides once they were placed.

Navigation had significantly less error from the planned osteotomy in neck shaft angle versus all other …

Lanthanide Nanoparticles As Contrast Agents For In Vivo Dual Energy Microcomputed Tomography Of The Mouse Vasculature, Charmainne Cruje

Electronic Thesis and Dissertation Repository

Dual energy (DE) computed tomography (CT) has the capability to influence medicine and pre-clinical research by providing quantitative information that can detect nascent lesions, identify perfusion restoration or inhomogeneities within tissues, and recognize the presence of calcium deposits. A wide variety of instrumentation techniques and scan protocols have been developed for DE CT, with a common goal of acquiring a pair of images that reports the attenuation of a given volume to two different x-ray distributions. While DE image acquisition has benefitted from technical advancements in CT, the contrast agents that are used are still predominantly composed of iodinated small …

Simulation Approaches To X-Ray C-Arm-Based Interventions, Daniel R. Allen

Electronic Thesis and Dissertation Repository

Mobile C-Arm systems have enabled interventional spine procedures, such as facet joint injections, to be performed minimally-invasively under X-ray or fluoroscopy guidance. The downside to these procedures is the radiation exposure the patient and medical staff are subject to, which can vary greatly depending on the procedure as well as the skill and experience of the team. Standard training methods for these procedures involve the use of a physical C-Arm with real X-rays training on either cadavers or via an apprenticeship-based program. Many guidance systems have been proposed in the literature which aim to reduce the amount of radiation exposure …

A 3d Printed Axon-Mimetic Diffusion Mri Phantom, Tristan K. Kuehn

Electronic Thesis and Dissertation Repository

Diffusion MRI is used to non-invasively characterize the microstructure of the brain. However, the accuracy of the characterization is difficult to verify because no other non-invasive imaging modality provides the same information. This thesis presents a novel 3D printed axon-mimetic (3AM) diffusion MRI phantom, a synthetic object designed to mimic the brain's microstructure.

The phantoms were characterized using microscopy, synchrotron micro-computed tomography, and diffusion MRI, and found to have sufficiently axon-mimetic properties to be useful as diffusion MRI phantoms. A set of phantoms designed to have anatomically realistic and complex fibre structures was used to test the response of diffusion …

Computational Modeling Of The Human Brain For Mtbi Prediction And Diagnosis, Yanir Levy

Electronic Thesis and Dissertation Repository

Sports related concussions and mild traumatic brain injuries have seen an increase in frequency over the past decade. The creation of highly biofidelic computational head models is an important step in understanding the mechanisms of these mild brain injuries and preventing them. Hence, the purpose of this research is to combine state-of-the-art computational models, brain imaging modalities and traditional head injury assessment protocols to simulate and predict the brains responses during traumatic head impacts. A novel, atlas-based, parcellated axon fiber embedded head model was developed which allows for in-depth analysis of the brain’s structural connectome tracts for injury diagnosis and …

A Biomechanical Investigation Into The Effect Of Experimental Design On Wrist Biomechanics And Contact Mechanics, Clare E. Padmore

Electronic Thesis and Dissertation Repository

The wrist is one of the most commonly injured joints, and injury can have serious sequelae if pathological healing ensues. Strides have been made to understand normal and pathological wrist biomechanics using experimental approaches, which has contributed to improved patient care. The present work advances our understanding of the influence of experimental techniques and joint motion measurement techniques on in-vitro wrist biomechanical cadaveric studies, and applies the knowledge learned to a common clinical entity of scapholunate insufficiency.

First, the relative contributions of the carpal rows to wrist motion were assessed, in addition to the identification of limitations of current biomechanical …

Development Of An Active Infection Monitoring Knee Spacer For Two-Stage Revision, Michael K. Lavdas

Electronic Thesis and Dissertation Repository

Infections requiring surgical revision occur in ~3% of total knee arthroplasty (TKA) procedures. The standard treatment for TKA infection in North America is referred to as the two-stage revision process. Unfortunately, the success rate of the two-stage revision is low, at roughly 85%. There are indications that the two-stage revision may fail to clear the infection due to unsatisfactory diagnostic tools. This thesis depicts the development and evaluation of a novel telemetric sensing package designed for integration into the two-stage revision process. Studies within evaluate its performance through sensor validation, thermal insulation testing, radio frequency penetration evaluation, a cadaveric loading …

Development Of Hybrid Coating Materials To Improve The Success Of Titanium Implants, Zach Gouveia

Electronic Thesis and Dissertation Repository

While titanium (Ti) and its alloys have become ubiquitous within implantology as materials to restore or augment the function of human tissues, their success is plagued by complications associated with infection and aseptic implant loosening. These two risks account for the majority of implant failures in the clinic and limit the long-term success of titanium implants in vivo. Therefore, this thesis describes the development of robust multifunctional class II organic-inorganic hybrid coating materials for titanium implants that could be used to effectively target both complications, concurrently. During this master’s work, two different coating systems were examined. First, class II …

Optimization Of Indentation For The Material Characterization Of Soft Pva-Cryogels, Md. Mansur Ul Mulk

Electronic Thesis and Dissertation Repository

Over the past few years a variety of clinical procedures aiming at tissue repair and other relevant therapies have been under active investigation [12,32]. Success of procedures aimed at soft tissue repair depend on the combined response of biochemical and biomechanical properties of the organs neighbouring the tissue [53]. Using human or animal cadaveric tissue for this purpose is very challenging due to issues pertaining to biodegradability and infection or biohazard risk factors [135,205].As such, tissue mimicking materials (e.g. Polyvinyl Alcohol Cryo-gel (PVA-C)) have been investigated to satisfy the need for the said clinical applications. Advantages of using tissue-mimicking materials …

Metal Additive Manufacturing For Fixed Dental Prostheses, Mai El Najjar

Electronic Thesis and Dissertation Repository

The use of additive manufacturing (AM) in dentistry has gained momentum in recent years. However, high initial costs and uncertainty surrounding the quality of AM products are considered barriers to their use. This research compared dental substructures fabricated by AM versus conventional casting and milling.

Cobalt-chromium alloy rectangular bars and three-unit bridge substructures were fabricated by AM, casting or milling. Bars manufactured by AM exhibited superior flexural strength, shear bond strength of porcelain coating, and Vickers hardness. Bridge substructures fabricated by AM showed similar flexural stiffness to cast, similar flexural loads at failure to milled and cast, and overall accuracy …

Detecting Command-Driven Brain Activity In Patients With Disorders Of Consciousness Using Tr-Fnirs, Androu Abdalmalak

Electronic Thesis and Dissertation Repository

Vegetative state (VS) is a disorder of consciousness often referred to as “wakefulness without awareness”. Patients in this condition experience normal sleep-wake cycles, but lack all awareness of themselves and their surroundings. Clinically, assessing consciousness relies on behavioural tests to determine a patient’s ability to follow commands. This subjective approach often leads to a high rate of misdiagnosis (~40%) where patients who retain residual awareness are misdiagnosed as being in a VS. Recently, functional neuroimaging techniques such as functional magnetic resonance imaging (fMRI), has allowed researchers to use command-driven brain activity to infer consciousness. Although promising, the cost and accessibility …

Cardiac Modelling Techniques To Predict Future Heart Function And New Biomarkers In Acute Myocardial Infarction, Sergio C. H. Dempsey

Electronic Thesis and Dissertation Repository

Fundamental to treatment planning for patients that have suffered myocardial infarction are predictive biomarkers and risk factors. Important among these in terms of a patient’s treatment plan or prognosis are the contractility of the damaged myofibers, final infarct volume, and poor infarct healing rate. Proposed and developed in this thesis are techniques to predict these biomarkers and risk factors using cardiac biomechanical modelling. One of the developed techniques was a CT compatible shape optimization technique which can predict the contraction force of healthy, and stunned myofibers within 6.3% and the distribution of potentially necrotic myofibers within 10% accuracy. The second …

3d Culture Strategies For The Dynamic Expansion And Preconditioning Of Adipose-Derived Stromal Cells On Decellularized Adipose Tissue Bioscaffolds, Tim Tian Han

Electronic Thesis and Dissertation Repository

Adipose tissue engineering holds promise for the development of therapeutic strategies for subcutaneous adipose tissue regeneration to treat defects resulting from congenital birth defects, invasive surgical procedures and traumatic injuries. Decellularized adipose tissue (DAT) scaffolds represent a potential off-the-shelf tissue substitute for volume augmentation. Seeding the DAT with adipose-derived stromal cells (ASCs) has been shown to enhance adipose tissue regeneration in immunocompetent animals in vivo. Although promising, this strategy is limited by low cell attachment on the DAT. As such, this thesis focused on the development of bioreactor strategies to enhance the capacity of human ASCs to stimulate angiogenesis …

Video Processing For The Evaluation Of Vascular Dynamics In Neurovascular Interventions, Reid Vassallo

Electronic Thesis and Dissertation Repository

An arteriovenous malformation (AVM) is an abnormal collection of blood vessels which causes blood to travel from arteries to veins through an abnormal twisted network of vessels. This network has an elevated risk of rupture, which can lead to permanent disability and death if the rupture occurs in the brain. The gold standard treatment for AVM is surgical resection, and it is crucial to know which vessels are bringing blood towards and away from the AVM. Unfortunately, it is almost impossible to know this by looking at the surgical scene. The primary limitations of current methods to address this are …

Edge-Cloud Iot Data Analytics: Intelligence At The Edge With Deep Learning, Ananda Mohon M. Ghosh

Electronic Thesis and Dissertation Repository

Rapid growth in numbers of connected devices, including sensors, mobile, wearable, and other Internet of Things (IoT) devices, is creating an explosion of data that are moving across the network. To carry out machine learning (ML), IoT data are typically transferred to the cloud or another centralized system for storage and processing; however, this causes latencies and increases network traffic. Edge computing has the potential to remedy those issues by moving computation closer to the network edge and data sources. On the other hand, edge computing is limited in terms of computational power and thus is not well suited for …

The Of Application Of 3d-Printing To Lumbar Spine Surgery, Andrew J. Kanawati

Electronic Thesis and Dissertation Repository

Rapid prototyping refers to the manufacturing process in which a three-dimensional (3D) digital model can be transformed into a physical model by layering material in the shape of successive cross sections atop of previously layers. Rapid prototyping has been increasing in popularity in the field of medicine and surgery due to the ability to personalize various aspects of patient care. The thesis will explore the use of rapid prototyping in lumbar spine surgery, aim to quantify the accuracy of medical imaging when relating to imaged structures and their corresponding models produced by rapid prototyping, and determine if complex patient-specific guides …

Structure-Function Relationships In The Brain: Applications In Neurosurgery, Daiana-Roxana Pur

Electronic Thesis and Dissertation Repository

Multimodal brain imaging allows the study of structure-function relationships of the brain at the individual level, a key subject in basic neuroscience with important applications in neurosurgery. The current thesis aims to better understand these relationships by (1) examining how cortical morphology metrics influence measures of brain function, (2) their visualization in augmented reality (AR), and (3) their application in neurosurgical planning. To achieve these objectives, we made use of multimodal magnetic resonance imaging (MRI) data: diffusion weighted imaging, resting-state functional MRI (rs-fMRI), task-based fMRI, and T1-weighted images. Various metrics were calculated: cortical thickness (CT), blood oxygen level dependent signal …

Machine Learning Towards General Medical Image Segmentation, Clara Tam

Electronic Thesis and Dissertation Repository

The quality of patient care associated with diagnostic radiology is proportionate to a physician's workload. Segmentation is a fundamental limiting precursor to diagnostic and therapeutic procedures. Advances in machine learning aims to increase diagnostic efficiency to replace single applications with generalized algorithms. We approached segmentation as a multitask shape regression problem, simultaneously predicting coordinates on an object's contour while jointly capturing global shape information. Shape regression models inherent point correlations to recover ambiguous boundaries not supported by clear edges and region homogeneity. Its capabilities was investigated using multi-output support vector regression (MSVR) on head and neck (HaN) CT images. Subsequently, …