Biomedical Engineering and Bioengineering Commons^™

Towards Patient Specific Mitral Valve Modelling Via Dynamic 3d Transesophageal Echocardiography, Patrick Carnahan

Electronic Thesis and Dissertation Repository

Mitral valve disease is a common pathologic problem occurring increasingly in an aging population, and many patients suffering from mitral valve disease require surgical intervention. Planning an interventional approach from diagnostic imaging alone remains a significant clinical challenge. Transesophageal echocardiography (TEE) is the primary imaging modality used diagnostically, it has limitations in image quality and field-of-view. Recently, developments have been made towards modelling patient-specific deformable mitral valves from TEE imaging, however, a major barrier to producing accurate valve models is the need to derive the leaflet geometry through segmentation of diagnostic TEE imaging. This work explores the development of volume …

Analysis And Characterization Of Embroidered Textile Strain Sensors For Use In Wearable Mechatronic Devices, Jose Guillermo Colli Alfaro

Electronic Thesis and Dissertation Repository

Stroke and musculoskeletal disorders affect hundreds of millions of people around the world. To aid in the recovery process of people affected by these conditions, the use of wearable mechatronic devices has been proposed during traditional rehabilitation therapies. However, factor such as rigidity, increased weight, and overall bulkiness have hindered the adoption of these devices in a clinical setting. Therefore, alternative solutions in the form of soft wearable mechatronic devices have been proposed recently. This is due to these devices being lightweight and comfortable, and compliant, which makes them easier to conform to the human body. To achieve such compliance, …

Characterizing Tkr Biomechanics Using A Novel Muscle-Driven Joint Motion Simulator, Alexandre Galley

Electronic Thesis and Dissertation Repository

Total knee replacement (TKR) is the end-stage treatment for severe cases of knee osteoarthritis (OA). Despite its success in alleviating pain and restoring mobility to the knee, patient satisfaction rates post-TKR are still lower than other common joint replacement surgeries. Knee kinematics and stability, key determinants of successful TKR, are assessed intraoperatively and tracked post-operatively in in vivo clinical studies. However, the persistently low satisfaction rates suggest that more sophisticated pre-clinical testing methods are needed to better understand the biomechanics of these implants early in their development. During pre-clinical testing of TKR implants, different joint motion simulators are used for …

Head Impact Effects In Small Remotely Piloted Aircraft System (Srpas) Collisions: Gender Specific Risks And Vulnerable Population Protection, Md Farhan Hoque Sagar

Electronic Thesis and Dissertation Repository

This study focuses on supporting the development of safety regulations for vulnerable populations during drone to head impacts. First, the small female head and neck model was compared to cadaveric data. Then, combined with lab’s previous work, gender-based disparities in head impact responses were highlighted, with small females experiencing higher injury risk metrics, despite lower skull von Mises stress. Beyond small females, children of various ages and their head responses during impacts were also analyzed. In addition to the previously developed quadcopter drone model, a new Mavic Pro drone model was developed, and this model was integrated with human head …

Free-Hand Photoacoustic Imaging Of Breast Cancer Tissue, Elina Rascevska

Electronic Thesis and Dissertation Repository

Approximately 19% of breast cancer patients undergoing breast conserving surgery (BCS) must return for a re-excision surgery due to positive margin reported by pathology. This problem is mainly associated with lack of intraoperative cancer margin assessment tools. Our previous work demonstrated that lipid-weighted photoacoustic imaging (PAI) can be used intraoperatively to successfully differentiate between cancerous and healthy tissue with high sensitivity. However, the technology was cumbersome and significantly prolonged the procedure time. The goal of this work was to develop a compact hand-held probe, working on lipid-weighted PAI principles, that can provide feedback during BSC without significantly altering the surgical …

Evaluating Eeg–Emg Fusion-Based Classification As A Method For Improving Control Of Wearable Robotic Devices For Upper-Limb Rehabilitation, Jacob G. Tryon

Electronic Thesis and Dissertation Repository

Musculoskeletal disorders are the biggest cause of disability worldwide, and wearable mechatronic rehabilitation devices have been proposed for treatment. However, before widespread adoption, improvements in user control and system adaptability are required. User intention should be detected intuitively, and user-induced changes in system dynamics should be unobtrusively identified and corrected. Developments often focus on model-dependent nonlinear control theory, which is challenging to implement for wearable devices.

One alternative is to incorporate bioelectrical signal-based machine learning into the system, allowing for simpler controller designs to be augmented by supplemental brain (electroencephalography/EEG) and muscle (electromyography/EMG) information. To extract user intention better, sensor …

Towards Clinical Microscopic Fractional Anisotropy Imaging, Nico Jj Arezza

Electronic Thesis and Dissertation Repository

Microscopic fractional anisotropy (µFA) is a diffusion-weighted magnetic resonance imaging (dMRI) metric that is sensitive to neuron microstructural features without being confounded by the orientation dispersion of axons and dendrites. µFA may potentially act as a surrogate biomarker for neurodegeneration, demyelination, and other pathological changes to neuron microstructure with greater specificity than other dMRI techniques that are sensitive to orientation dispersion, such as diffusion tensor imaging. As with many advanced imaging techniques, µFA is primarily used in research studies and has not seen use in clinical settings.

The primary goal of this Thesis was to assess the clinical viability of …

Novel Magnetic Resonance Imaging-Compatible Mechatronic Needle Guidance System For Prostate Focal Laser Ablation Therapy, Eric R. Knull

Electronic Thesis and Dissertation Repository

Advances in prostate cancer (PCa) screening techniques have led to diagnosis of many cases of low-grade and highly localized disease. Conventional whole-gland therapies often result in overtreatment in such cases and debate still surrounds the optimal method of oncologic control. MRI-guided prostate focal laser ablation (FLA) is a minimally invasive treatment option, which has demonstrated potential to destroy localized lesions while sparing healthy prostatic tissue, thereby reducing treatment-related side effects. Many challenges still exist in the development of FLA, including patient selection; tumour localization, visualization, and characterization; needle guidance; and evaluation of treatment efficacy. The objective of this thesis work …

Development And Validation Of Mechatronic Systems For Image-Guided Needle Interventions And Point-Of-Care Breast Cancer Screening With Ultrasound (2d And 3d) And Positron Emission Mammography, Claire Ks Park

Electronic Thesis and Dissertation Repository

The successful intervention of breast cancer relies on effective early detection and definitive diagnosis. While conventional screening mammography has substantially reduced breast cancer-related mortalities, substantial challenges persist in women with dense breasts. Additionally, complex interrelated risk factors and healthcare disparities contribute to breast cancer-related inequities, which restrict accessibility, impose cost constraints, and reduce inclusivity to high-quality healthcare. These limitations predominantly stem from the inadequate sensitivity and clinical utility of currently available approaches in increased-risk populations, including those with dense breasts, underserved and vulnerable populations.

This PhD dissertation aims to describe the development and validation of alternative, cost-effective, robust, and high-resolution …

Using Statistics, Computational Modelling And Artificial Intelligence Methods To Study And Strengthen The Link Between Kinematic Impacts And Mtbis, Andrew Luke Mcconnell Patterson

Electronic Thesis and Dissertation Repository

Mild traumatic brain injuries (mTBIs) are frequently occurring, yet poorly understood, injuries in sports (e.g., ice hockey) and other physical recreation activities where head impacts occur. Helmets are essential pieces of equipment used to protect participants’ heads from mTBIs. Evaluating the performance of helmets to prevent mTBIs using simulations on anatomically accurate computational head finite element models is critically important for advancing the development of safer helmets. Advancing the level of detail in, and access to, such models, and their continued validation through state-of-the-art brain imaging methods and traditional head injury assessment procedures, is also essential to improve safety. The …

Improving The Reliability And Accessibility Of Ct Perfusion Imaging In Acute Ischemic Stroke, Kevin J. Chung

Electronic Thesis and Dissertation Repository

CT perfusion (CTP) imaging is a validated treatment decision support tool in acute ischemic stroke. Automated analysis of CTP cerebral blood flow (CBF) and Tmax maps produces estimates of ischemic core and penumbra volumes used to determine target mismatch profiles for treatment. However, availability and utilization of CTP is low due to diagnostic variability between CTP software and technical, logistical, and radiation dose considerations that may limit its routine adoption. The objective of this doctoral research was to improve the reliability and accessibility of CTP by (1) improving diagnostic agreement between CTP software, (2) enabling perfusion imaging with standard acute …

Development Of A Cell-Based Regenerative Strategy To Modulate Angiogenesis And Inflammation In Ischemic Muscle, Fiona E. Serack

Electronic Thesis and Dissertation Repository

The delivery of human adipose-derived stromal cells (hASCs) to ischemic tissues represents a promising strategy to promote vascular regeneration for patients with critical limb ischemia (CLI). This thesis focused on the evaluation of hydrogels to enhance the retention and pro-angiogenic capacity of hASCs following delivery in vivo. Additionally, priming strategies to augment the paracrine function of hASCs were developed and assessed.

Recognizing the importance of endogenous macrophages in the pro-regenerative function of hASCs, delivery using a previously-developed hydrogel system, composed of peptide-functionalized methacrylated glycol chitosan (MGC-RGD) and a copolymer of poly(ethylene glycol) and poly(trimethylene carbonate) (PEG(PTMC-A)₂), was …

Developing A Finite Element Model For Evaluating The Posterior Tibial Slope In A Medial Opening Wedge High Tibial Osteotomy, Victor Alexander Carranza

Electronic Thesis and Dissertation Repository

This thesis aimed to develop and validate a computation finite element (FE) model to investigate the effect of hinge axis orientation on the posterior tibial slope (PTS) and mechanical medial proximal tibial angle (mMPTA) while analyzing the mechanical response around the hinge in a medial opening wedge high tibial osteotomy (MOWHTO). Chapter 2 highlights the importance of selecting an appropriate modeling method that best represents the clinical scenario. Chapter 3 validated a FE model using the Bland-Altman agreement analysis which yielded 95% limits of agreement of −0.9° to 1.2° for PTS and −1.4° to 1.9° for mMPTA. A parametric study …

Investigation Of Dynamic Culture On Matrix-Derived Microcarriers As A Strategy To Modulate The Pro-Regenerative Phenotype Of Human Adipose-Derived Stromal Cells, Mckenna R. Tosh

Electronic Thesis and Dissertation Repository

Pre-conditioning of adipose-derived stromal cells (ASCs) by tuning the cellular microenvironment during expansion has the potential to modulate their pro-regenerative functionality. The current study investigated the effects of microcarrier composition (decellularized adipose tissue versus collagen), oxygen tension (2% versus ~20% O₂) and stirring rate (static, 20, 40 rpm) on human ASCs cultured within spinner flask bioreactors. Dynamic culturing under 20% O₂ resulted in more consistent cell growth on both microcarrier substrates, leading to increases in microcarrier contraction and stiffness. Culturing on the microcarriers modulated the hASC immunophenotype, with varying CD90 and CD26 expression levels observed under the …