Engineering Commons^™

A Framework For Stable Robot-Environment Interaction Based On The Generalized Scattering Transformation, Kanstantsin Pachkouski

Electronic Thesis and Dissertation Repository

This thesis deals with development and experimental evaluation of control algorithms for stabilization of robot-environment interaction based on the conic systems formalism and scattering transformation techniques. A framework for stable robot-environment interaction is presented and evaluated on a real physical system. The proposed algorithm fundamentally generalizes the conventional passivity-based approaches to the coupled stability problem. In particular, it allows for stabilization of not necessarily passive robot-environment interaction. The framework is based on the recently developed non-planar conic systems formalism and generalized scattering-based stabilization methods. A comprehensive theoretical background on the scattering transformation techniques, planar and non-planar conic systems is presented. …

Mechanical Evaluation Of Gyroid Structures To Combat Orthopaedic Implant Infections, Sydney Hitchon

Electronic Thesis and Dissertation Repository

Treatment of infected orthopaedic implants often require two separate surgeries to clear the infection and install a replacement implant. Current antimicrobial drug delivery methods are inefficient, and each additional surgery increases the physiologic burden on patients, with an increased risk of infection, decreased range of motion and longer recovery times. Porous orthopaedic implants, with adequate strength for permanent implantation and the ability to house and elude more efficient antibiotic delivery systems, could result in a single surgery to treat orthopaedic infections. Therefore, finite element models of porous gyroid structures at different porosities were developed and compared with experimental results. Discrepancies …

Development Of A Near-Full-View Angle Coverage Photoacoustic Tomography System And Its Application Towards Optical Fluence Distribution Imaging, Lawrence Cm Yip

Electronic Thesis and Dissertation Repository

Photoacoustic tomography (PAT) is a widely explored hybrid imaging modality combining advantages of ultrasound and optical imaging. However, on the acoustic detection side, limited-view angle coverage and limited-detector bandwidth are common key issues in PAT systems that result in unwanted artifacts. While analytical and simulation studies of limited-view artifacts are extensive, experimental setups capable of comparing limited-view to an ideal full-view case are lacking. Due to the lack of PAT systems capable of artifact-free full-view imaging, applications for such a system have also been left unexplored.

A custom ring-shaped detector array was assembled and mounted to a 6-axis robot, which …

Development Of A Hybrid Stereotactic Guidance System For Percutaneous Liver Tumour Ablation, Joeana N. Cambranis Romero

Electronic Thesis and Dissertation Repository

Stereotactic Image-Guided Surgical Navigation System (IGSNS) supports percutaneous procedures by using medical imaging and tracking information, to assist the surgeons in the preprocedural planning and intraprocedural steps. This thesis describes the development of a stereotactic IGSNS for percutaneous liver tumour ablation, the goal of which is to assist in positioning the tip of the ablation applicator accurately to ensure complete tumour coverage. The main system improvement is the employment of a mini stereotactic patient-attach aiming device that is used as a pointer to ensure needle tip position prior to needle insertion. The thesis chapters describe the development and validation of …

Modelling And Evaluation Of Piezoelectric Actuators For Wearable Neck Rehabilitation Devices, Shaemus D. Tracey

Electronic Thesis and Dissertation Repository

Neck pain is the most common neck musculoskeletal disorder, and the fourth leading cause of healthy years lost due to disability in the world. Due to the need of hands-on physical therapy and Canada’s aging population, access to treatment will become highly constrained. Wearable devices that allow at-home rehabilitation address this future limitation. However, few have emerged from the laboratory setting because they are limited by the use of conventional actuators. An overlooked type of actuation technology is that of piezoelectric actuators, more specifically, travelling wave ultrasonic motors (TWUM).

In this work, a clear procedure that outlines how the required …

Conducting Polypyrrole Hydrogel Biomaterials For Drug Delivery And Cartilage Tissue Regeneration, Iryna Liubchak

Electronic Thesis and Dissertation Repository

Articular cartilage tissue has limited capacity for self-regeneration leading to challenges in the treatment of joint injuries and diseases such as osteoarthritis. The tissue engineering approach combines biomaterials, cells and bioactive molecules to provide a long-term and stable cartilage repair. In the following work, electroactive polymer polypyrrole~(PPy) was incorporated into the synthetic hydrogel to enhance the mechanical properties of the material for cartilage applications. PPy was loaded with drug compound and the \emph{on demand} drug release was demonstrated. The composite PPy hydrogel was 3D printed using stereolithography to create a porous tissue engineering scaffold. Biocompatibility and cell adhesion to the …

The Development Of A Motion Sensing Device For Use In A Home Setting, Jaspreet K. Kalsi

Electronic Thesis and Dissertation Repository

Parkinson's disease (PD) is the second most prevalent neurodegenerative disease, with over 10 million individuals diagnosed with PD world-wide. The most common symptom characterized by PD is tremor. Tremor is an involuntary oscillatory motion that most prominently occurs in upper limb, specifically in the hand and wrist that has a measurable frequency and amplitude. This thesis aims to evaluate the usability and functionality of a tremor sensing device designed to collect quantitative data on individuals with PD. The designed device uses 23 commercially-available inertial measuring units (IMUs) located between 21 joints: distal interphalangeal (DIP) joints, proximal interphalangeal (PIP) joints, Interphalangeal …

Intracardiac Ultrasound Guided Systems For Transcatheter Cardiac Interventions, Hareem Nisar

Electronic Thesis and Dissertation Repository

Transcatheter cardiac interventions are characterized by their percutaneous nature, increased patient safety, and low hospitalization times. Transcatheter procedures involve two major stages: navigation towards the target site and the positioning of tools to deliver the therapy, during which the interventionalists face the challenge of visualizing the anatomy and the relative position of the tools such as a guidewire. Fluoroscopic and transesophageal ultrasound (TEE) imaging are the most used techniques in cardiac procedures; however, they possess the disadvantage of radiation exposure and suboptimal imaging. This work explores the potential of intracardiac ultrasound (ICE) within an image guidance system (IGS) to facilitate …

A Two-Layer Continuous-Capillary Oxygen Transport Model: Development And Application To Blood Flow Regulation In Resting Skeletal Muscle., Keith C. Afas

Electronic Thesis and Dissertation Repository

In skeletal muscle (SM), the microcirculation distributes blood flow to capillary networks to meet local oxygen (O₂) demand. Experiments using intra-vital video microscopy (IVVM) have quantified blood flow and O₂ supply in capillary networks, and using an O₂ exchange chamber have measured local changes in blood flow believed due to O₂-dependent regulation. However, IVVM is unable to simultaneously measure capillary O₂ supply and SM O₂ content, implying the need for theoretical models to understand how flow regulation and SM oxygenation interact. In this thesis, a novel blood-tissue O₂ transport model using …

Motion And Crosslinked Polyethylene Wear In Reverse Total Shoulder Arthroplasty, Christopher Millward

Electronic Thesis and Dissertation Repository

The reverse total shoulder arthroplasty (RTSA) has quickly grown to become the most commonly used shoulder arthroplasty design; however, reports have shown evidence of RTSA failures related to polyethylene wear and damage. Therefore, the present work investigated the wear of crosslinked polyethylene (XLPE) in environments similar to that of an in vivo RTSA. Additionally, a computational model was developed based on a previous study of the shoulder motions obtained from a selection of typical patients with RTSA. This model quantified the amount of glenohumeral motion that an RTSA may be subjected to in vivo and provided an approximate value for …

Large-Scale Analysis And Automated Detection Of Trunnion Corrosion On Hip Arthroplasty Devices, Anastasia M. Codirenzi

Electronic Thesis and Dissertation Repository

Corrosion at the modular head-neck taper interface of total and hemiarthroplasty hip implants (trunnionosis) is a cause of implant failure and thus a clinical concern. Patient and device factors contributing to the occurrence of trunnionosis have been investigated in prior implant retrieval studies. The Goldberg corrosion scoring method is considered the gold standard for observing trunnionosis, but it is labour-intensive. As a result, previous studies have generally looked at under 250 implants for analysis. The purpose of this thesis was to do a large-scale analysis of trunnionosis and explore its relationship to device and patient factors and compare to previously …

Biomechanical Investigation Of Complete And Partial Medial Collateral Ligament Injuries, Callahan Doughty

Electronic Thesis and Dissertation Repository

The medial collateral ligament (MCL) is composed of two major components: the deep MCL (dMCL) and superficial MCL (sMCL). Recent indications have raised questions as to the validity of previous descriptions of the MCL’s role in knee stability. Despite the relative likelihood of partial injuries to the sMCL, as opposed to complete tears, the impact of these injuries remains largely misunderstood. This thesis set out to (1) interpret the roles of the sMCL and dMCL; and (2) investigate the effect of partial sMCL injuries on knee stability.

A joint motion simulator was used to determine the role of the dMCL …

Development Of Brain-Derived Bioscaffolds For Neural Progenitor Cell Culture And Delivery, Julia Terek

Electronic Thesis and Dissertation Repository

The use of brain extracellular matrix (ECM) as a biomaterial has the potential to promote neural tissue regeneration by providing cell-instructive cues that direct survival, proliferation, and differentiation. This study developed a novel detergent-free decellularization protocol that effectively reduced cellular content while preserving key ECM components in porcine and rat brains. The resulting decellularized brain tissue (DBT) was incorporated into microcarriers to assess its effects on the growth, phenotype and neurotrophic factor gene expression of rat brain-derived progenitor cells cultured within spinner flask bioreactors, using purified collagen microcarriers as a control. Both types of microcarriers supported cell expansion and survival, …

Early Biological Response Of Articular Cartilage To Hemiarthroplasty Wear, Debora Rossetti

Electronic Thesis and Dissertation Repository

Hemiarthroplasties typically result in accelerated wear of the preserved side of the joint, resulting in suboptimal clinical outcomes and limited longevity. This in vitro study investigated the effects of hemiarthroplasty implant curvature on the early biological response of articular cartilage measured by proteoglycan release, histology, and surface morphology. Cartilage from boar radiocarpal joints were worn by metal pins of varying radii of curvature (RoC) using a pin-on-plate wear simulator. Histology and proteoglycan assays showed no significant differences between RoC treatment groups, and proteoglycan assays showed increased proteoglycan release 72 hours after wear testing in worn cartilage specimens compared to control …

The Application Of Digital Volume Correlation Bone Strain Measurements In The Osteoarthritic Glenohumeral Joint, Jakub R. Targosinski

Electronic Thesis and Dissertation Repository

This thesis investigates the accuracy and precision of digital volume correlation measurements derived from micro-computed tomography imagery of interfaces in the upper extremity of clinical relevance, namely, the implant-cement-bone interface of glenoid implants used in total shoulder arthroplasties and the implant-bone interface of shoulder hemiarthroplasties. The works within derive relationships between measurement accuracy and precision and parameters of practical interest such as image quality and measurement spatial resolution. It also analyzes the effects of micro-computed tomography image artifact-inducing materials on the accuracy and precision of digital volume correlation-based measurements and the spatial relationship between distance between the artifacting material and …

A Novel Ultrasound Elastography Technique For Evaluating Tumor Response To Neoadjuvant Chemotherapy In Patients With Locally Advanced Breast Cancer, Niusha Kheirkhah

Electronic Thesis and Dissertation Repository

Breast cancer is the second most diagnosed cancer in women, estimated to affect 1 in 8 women during their lifetime. About 10% to 20% of new breast cancer cases are diagnosed with locally advanced breast cancer (LABC). LABC tumors are usually larger than 5 cm and/or attached to the skin or chest wall. It has been reported that when such cases are treated with surgery alone, metastasis and mortality rates are high, especially where skin involvement or attachment to the chest wall is extensive. As such, efficient treatment for this kind of breast cancer includes neoadjuvant chemotherapy (NAC) to shrink …

The Effects Of A Porous Internal Lattice Design On The Articular Contact Mechanics Of Radial Head Hemiarthroplasty Implants, Jessica Benitah

Electronic Thesis and Dissertation Repository

Hemiarthroplasty, where one side of a joint is replaced, is a minimally invasive procedure. It allows for the preservation of native tissue, though a significant ramification is accelerated cartilage wear when articulating with high stiffness materials that do not mimic the mechanical stiffness of the native tissue. An implant that employs a lattice design can significantly lower the stiffness of a solid structure whilst maintaining strength. This study was conducted to investigate the effect of implementing a porous internal lattice structure with a thin outer shell on the articular contact mechanics, using a radial head hemiarthroplasty. It was hypothesized that …

The Bio-Mechanical Development And Kinematic Evaluation Of Zone I And Zone Ii Injuries And Their Corresponding Surgical Repair Techniques Using An In-Vitro Active Finger Motion Simulator: A Cadaveric Study, Mohammad Haddara

Electronic Thesis and Dissertation Repository

Research development involving large scale joint mechanics and biomechanical adaptations is growing. However, interest in smaller scale joints, such as the fingers, is limited. Thus, the present work describes the enhancement and clinical application of a previously designed in-vitro active finger motion simulator in measuring and assessing intrinsic joint kinematics and tissue biomechanics including load transfer and strains induced tissues within the finger. Accuracy of electromagnetic tracking (EM) systems were evaluated compared to the standard optical tracking systems and used to develop motion derived finger joint coordinate systems. Moreover, minute strain gauges were utilized to measure strains induced by the …

Sol-Gel Derived Bioceramic Poly(Diethyl Fumarate – Co – Triethoxyvinylsilane) Composite, Aref Sleiman

Electronic Thesis and Dissertation Repository

Synthetic bone graft materials have become an increasingly popular choice for bone augmentation. Ceramic-based and polymer-based bone graft materials constitute the two main classes of synthetic bone graft materials. This study investigated the synthesis of novel bioactive composites for their potential use as bone graft biomaterials. Poly(diethyl fumarate-co-triethoxyvinylsilane)/bioceramic class II organic/inorganic hybrid biomaterials were synthesized via a sol gel process. These biomaterials were then reacted with an ammonium phosphate solution to prepare their respective composites. For the first time, we successfully synthesized sol-gel derived bioceramic poly(diethyl fumarate-co-triethoxyvinylsilane) composites. In vitro bioactivity evaluation of poly(diethyl fumarate-co-triethoxyvinylsilane)/bioceramic composites in simulated body fluid …

Cost-Effective Non-Destructive Testing Of Biomedical Components Fabricated Using Additive Manufacturing, Santiago Fabian Cobos

Electronic Thesis and Dissertation Repository

Biocompatible titanium-alloys can be used to fabricate patient-specific medical components using additive manufacturing (AM). These novel components have the potential to improve clinical outcomes in various medical scenarios. However, AM introduces stability and repeatability concerns, which are potential roadblocks for its widespread use in the medical sector. Micro-CT imaging for non-destructive testing (NDT) is an effective solution for post-manufacturing quality control of these components. Unfortunately, current micro-CT NDT scanners require expensive infrastructure and hardware, which translates into prohibitively expensive routine NDT. Furthermore, the limited dynamic-range of these scanners can cause severe image artifacts that may compromise the diagnostic value of …

The Role Of Transient Vibration Of The Skull On Concussion, Rodrigo Dalvit Carvalho Da Silva

Electronic Thesis and Dissertation Repository

Concussion is a traumatic brain injury usually caused by a direct or indirect blow to the head that affects brain function. The maximum mechanical impedance of the brain tissue occurs at 450±50 Hz and may be affected by the skull resonant frequencies. After an impact to the head, vibration resonance of the skull damages the underlying cortex. The skull deforms and vibrates, like a bell for 3 to 5 milliseconds, bruising the cortex. Furthermore, the deceleration forces the frontal and temporal cortex against the skull, eliminating a layer of cerebrospinal fluid. When the skull vibrates, the force spreads directly to …