Biomedical Engineering and Bioengineering Commons^™

The Efficacy Of Bionate As An Articulating Surface For Joint Hemiarthroplasty, Sarah Dedecker

Electronic Thesis and Dissertation Repository

Hemiarthroplasty procedures replace the diseased side of the joint with an implant to maximize bone preservation while maintaining more native anatomy than a total joint replacement. Even though hemiarthroplasty procedures have been clinically successful, they cause progressive cartilage damage over time due to the use of relatively stiff metallic implant materials. This work investigates the role of low moduli implant material on implant-cartilage contact mechanics and early in vitro cartilage wear. A finite element simulation was developed to assess the effect of low moduli implants in the range of 0.015-0.288 GPa on contact mechanics. Higher contact area and lower peak …

The Role Of Scapular Morphology In Reverse Shoulder Arthroplasty, Ashish Gupta

Electronic Thesis and Dissertation Repository

Baseplate fixation in a reverse shoulder arthroplasty depends on adequate bone stock. In cases of severe glenoid bone loss and revision shoulder arthroplasty, deficiency of the glenoid vault compels the surgeon to attain screw fixation in the three columns of the scapula. The relationship of these columns demonstrated that the coracoid is closer to the lateral scapular pillar in females than in males. Significant gender dimorphism exists between the orientations of the three columns. The gender dimorphism is further evaluated by anthropometric measurements of the scapular body and the glenoid. The clinical significance lies in the ability to reconstruct the …

Miniature Implantable Telemetry System For Pressure-Volume Cardiac Monitoring, Kyle G. Fricke

Electronic Thesis and Dissertation Repository

Safety Pharmacology is becoming an increasingly important field to pharmaceutical companies in order to determine if medical treatments (drugs) are safe for use in human subjects. In the pre-clinical phase, test models, most commonly small rodents, undergo various gene alterations to affect, for example, their cardiovascular system in order to emulate human diseases. Pharmaceutical companies rely on these models to determine the drug efficacy and to ensure minimal side effects and safety for human subjects. Currently, no fully implantable left-ventricle pressure--volume (PV) telemetry systems have been implemented for Safety Pharmacology assessment applications. A fully implantable PV telemetry system would not …

Performance Factors In Neurosurgical Simulation And Augmented Reality Image Guidance, Ryan Armstrong

Electronic Thesis and Dissertation Repository

Virtual reality surgical simulators have seen widespread adoption in an effort to provide safe, cost-effective and realistic practice of surgical skills. However, the majority of these simulators focus on training low-level technical skills, providing only prototypical surgical cases. For many complex procedures, this approach is deficient in representing anatomical variations that present clinically, failing to challenge users’ higher-level cognitive skills important for navigation and targeting. Surgical simulators offer the means to not only simulate any case conceivable, but to test novel approaches and examine factors that influence performance. Unfortunately, there is a void in the literature surrounding these questions. This …

Evaluation System For Craniosynostosis Surgeries With Computer Simulation And Statistical Modelling, Jing Jin

Electronic Thesis and Dissertation Repository

Craniosynostosis is a pathology in infants when one or more sutures prematurely closed, leading to abnormal skull shape. It has been classified according to the specific suture that has been closed, each of which has a typical skull shape. Surgery is the common treatment to correct the deformed skull shape and to reduce the excessive intracranial pressure. Since every case is unique, the cranial facial teams have difficulties to select an optimum solution for a specific patient from multiple options. In addition, there is not an appropriate quantified measurement existed currently to help cranial facial team to quantitatively evaluate their …

Electrospinning Of Poly (Ester Amide) Fibres For Mesenchymal Progenitor Cell Differentiation, Sarah Kiros

Electronic Thesis and Dissertation Repository

The in vitro vascular tissue engineering paradigm seeks to produce biologically responsive vascular substitutes using cells, biodegradable scaffolds, and bioreactors to mature the tissue for the potential treatment of vascular occlusions and to create 3D tissue models for pre-clinical testing. In this work, a poly (ester amide) (PEA) derived from from L-phenylalanine, sebacoyl chloride and 1,4 butanediol was synthesized and electrospun to form both 3D fibrous mats and tubular constructs. Both the polymer solution concentration and mandrel rotation speed were optimized to fabricate bead-free fibres. Cytocompatibility and proliferation studies using mesenchymal progenitor 10T1/2 cells showed PEA fibres were not cytotoxic …

Low Frequency Bio-Electrical Impedance Mammography And Dielectric Measurement, Seyyed Hesabgar

Electronic Thesis and Dissertation Repository

Assessment of electrical impedance of biological tissues at low frequencies offers a great potential for a safe, simple, and low-cost medical breast imaging techniques such as mammography. As such, in this dissertation a mammography method which uses tissue electrical impedance to detect breast malignancies was developed. The dissertation also introduces a new technique for measuring the dielectric properties of biological tissues at low frequencies. The impedance mammography technique introduced in this study is founded on the assumption that dielectric values of breast malignancies are significantly higher than the dielectric values of normal breast tissues. While previous studies have shown that …

Neurosurgical Ultrasound Pose Estimation Using Image-Based Registration And Sensor Fusion - A Feasibility Study, Utsav Pardasani

Electronic Thesis and Dissertation Repository

Modern neurosurgical procedures often rely on computer-assisted real-time guidance using multiple medical imaging modalities. State-of-the-art commercial products enable the fusion of pre-operative with intra-operative images (e.g., magnetic resonance [MR] with ultrasound [US] images), as well as the on-screen visualization of procedures in progress. In so doing, US images can be employed as a template to which pre-operative images can be registered, to correct for anatomical changes, to provide live-image feedback, and consequently to improve confidence when making resection margin decisions near eloquent regions during tumour surgery.

In spite of the potential for tracked ultrasound to improve many neurosurgical procedures, it …

A Biomechanical Investigation Of Scaphoid And Lunate Kinematics During Wrist Motion, Helen L. Stoesser

Electronic Thesis and Dissertation Repository

Carpal kinematics have been previously investigated, yet there remains no consensus regarding the relative contribution of each bone to total wrist motion. A more detailed understanding of carpal kinematics is essential in the effective diagnosis and treatment of injuries of the wrist, as many injuries manifest as an alteration in intercarpal kinematics. The scapholunate (SL) ligament is one of the most commonly injured intercarpal articulations resulting in a cascade of degenerative changes included cartilage wear and altered joint kinematics. The SL ligament is considered the primary stabilizer of the SL joint but is surrounded by a complex network of secondary …

Elbow Patients’ Data Collection And Analysis: An Examination Of Electromyography Healing Patterns, Raneem Haddara

Electronic Thesis and Dissertation Repository

Musculoskeletal conditions are the most common cause of severe long-term pain and physical disability, accounting for the highest disability costs of about $17 billion yearly. To provide better rehabilitation tactics, the knowledge gap between injuries and their healing mechanisms needs to be addressed. The use of electromyography (EMG) is very popular in detecting neuromuscular diseases or nerve lesions; however, there is limited knowledge available for quantifying healing patterns of EMG in orthopedic patients who have injured their joints, muscles, or bones. In order to quantify the progress of orthopedic patients and assess their neuromuscular health and muscle synergy patterns, EMG …

Adipose-Derived Stem Cell Differentiation In Cell Aggregates Supplemented With Micronized, Decellularized Extracellular Matrix, Danielle Heinbuch

Electronic Thesis and Dissertation Repository

In the human body there are tissues with limited regenerative potential, raising the need for cell-based regenerative therapies. The main objective of this thesis was to examine how tissue-specific extracellular matrix (ECM) affects the differentiation of human adipose-derived stem/stromal cells (ASCs). The effects of incorporating milled, decellularized adipose (DAT) or cartilage (DCT) ECM particles on ASC lineage-specific differentiation in 3-D cell aggregate cultures were explored. The results demonstrated that the addition of ECM improved differentiation for both adipogenesis and chondrogenesis. Analysis of adipogenic gene and protein expression indicated enhanced differentiation in the DAT+ASC aggregates relative to the DCT+ASC and ASC-alone …

Controlled Delivery Of Angiogenic And Arteriogenic Growth Factors From Biodegradable Poly(Ester Amide) Electrospun Fibers For Therapeutic Angiogenesis, Somiraa S. Said

Electronic Thesis and Dissertation Repository

Therapeutic angiogenesis relies on the delivery of exogenous growth factors to stimulate neovessel formation. However, systemic administration of angiogenic factors results in rapid clearance from the site of interest due to their short biological half-life. In this work, we are reporting controlled delivery of a ‘cocktail’ of growth factors, an angiogenic factor −fibroblast growth factor-2 (FGF2), and an arteriogenic factor −fibroblast growth factor-9 (FGF9), from biodegradable poly(ester amide) (PEA) electrospun fibers towards targeting neovascular formation and maturation. FGF2 and FGF9 were dual loaded into PEA fibers using a mixed blend and emulsion electrospinning technique. Matrigel tube formation and Boyden chamber …

Fermentative Processes Requiring Low Solubility Feed Gases: An Investigation Into Gas-Dependent Microorganisms, Eric W. Doerr

Electronic Thesis and Dissertation Repository

Two bioprocesses were separately investigated based on their common interest of using gaseous substrates that have low solubility. The first process involved the development of a mixed culture using two organisms capable of utilizing glycerol and carbon monoxide separately to increase biobutanol production, while the second process involved an investigation of different production media used in aerobic xanthan production of Xanthomonas campestris with pressurization effects. It was determined that Clostridium pasteurianum should be used with an organism like Clostridium carboxidivorans or Eubacterium limosum in order for butyrate uptake at 3 g/L to occur with a minimum 0.1 g/L butyrate production. …

A Novel Composite Material-Based Computational Model For Left Ventricle Biomechanics Simulation, Seyyed Mohammad Hassan Haddad

Electronic Thesis and Dissertation Repository

To model cardiac mechanics effectively, various mechanical characteristics of cardiac muscle tissue including anisotropy, hyperelasticity, and tissue active contraction characteristics must be considered. Some of these features cannot be implemented using commercial finite element (FE) solvers unless additional custom-developed computer codes/subroutines are appended. Such codes/subroutines are unavailable for the research community. Accordingly, the overarching objective of this research is to develop a novel LV mechanics model which is implementable in commercial FE solvers and can be used effectively within inverse FE frameworks towards cardiac disease diagnosis and therapy. This was broken down into a number of objectives. The first objective …

Ultra-High Field Strength Mr Image-Guided Robotic Needle Delivery Device For In-Bore Small Animal Interventions, Matthew J. Gravett

Electronic Thesis and Dissertation Repository

Current methods of accurate soft tissue injections in small animals are prone to many sources of error. Although efforts have been made to improve the accuracy of needle deliveries, none of the efforts have provided accurate soft tissue references. An MR image-guided robot was designed to function inside the bore of a 9.4T MR scanner to accurately deliver needles to locations within the mouse brain. The robot was designed to have no noticeable negative effects on the image quality and was localized in the MR images through the use of an MR image visible fiducial. The robot was mechanically calibrated …

In-Situ Ultrasound Calibration, Azharhosein Faraz

Electronic Thesis and Dissertation Repository

In minimally invasive navigated mitral valve repair surgery, the spatial calibration of the trans-esophageal echocardiography (TEE) ultrasound probe to the magnetic tracking system is an essential requisite. The standard calibration approach requires scanning a specialized phantom prior to the surgery, which is associated with the scaling mismatch issue. Preoperative estimation of the speed-of-sound at the target site of surgery is impractical as it varies among individual patients, leading to significant calibration errors during surgery.

In order to resolve this issue, we propose an un-precedented method of `in-situ' ultrasound calibration, utilizing the tracked surgical tool, which is scanned by the bi-plane …

Mechanical Properties Of Poly (Vinyl Alcohol) Based Blends And Composites, Nazanin Afghan

Electronic Thesis and Dissertation Repository

One of the most important product specifications in design of materials for different applications is to closely match desired mechanical properties of the target. The soft tissue could be very elastic such as blood vessels and skin, whereas others are soft and non-elastic such as fat tissue. Soft human tissue has a diverse structural component that give them the different feel, texture, shape, and mechanical properties.

Poly (vinyl alcohol) (PVA) as hydrophobic polymer has outstanding features such as very good physico-mechanical properties, nontoxicity and biocompatibility, and high swelling properties which makes them favorable for biomaterial and biomedical applications. By physically …

A Novel Minimally Invasive Tumour Localization Device, Doran Avivi

Electronic Thesis and Dissertation Repository

Lung cancer is one of the leading causes of death, by cancer. The usual treatment is surgical resection of tumours. However, patients who are weak or have poor pulmonary function are deemed unfit for surgery. For these patients, a minimally-invasive approach is desired. A major problem associated with minimally-invasive approaches is tumour localization in real time and accurate measurement of tool--tissue forces.

This thesis describes the design, analysis, manufacturing and validation of a minimally-invasive instrument for tumour localization, named Palpatron. The instrument has an end effector that is able to support two previously designed jaws, one containing an ultrasound sensor …

Markerless Radiostereogammetry Of The Shoulder Joint In Humans: Comparisons Of Scapulohumeral Kinematics Between Individuals With Healthy And Supraspinatus-Impaired Shoulders, Ashley N. Hannon

Electronic Thesis and Dissertation Repository

The purpose of this collection of studies was to further develop the knowledge of shoulder motion in order to better understand joint function through direct measurement of 3D scapulohumeral joint kinematics using a technique of high accuracy. Markerless, bi-planar fluoroscopic radiostereometric analysis using a generic shoulder model was developed in this thesis, reducing the amount of radiation exposure to subjects. The studies compared kinematic data of the scapulohumeral joint in six degrees of freedom with a precise, in-vivo measuring technique. Data were collected on young and older healthy individuals, individuals with a torn supraspinatus and post-surgical intervention.

Although this generic …

Validation Strategies Supporting Clinical Integration Of Prostate Segmentation Algorithms For Magnetic Resonance Imaging, Maysam Shahedi Bagh Khandan

Electronic Thesis and Dissertation Repository

Segmentation of the prostate in medical images is useful for prostate cancer diagnosis and therapy guidance. However, manual segmentation of the prostate is laborious and time-consuming, with inter-observer variability. The focus of this thesis was on accuracy, reproducibility and procedure time measurement for prostate segmentation on T2-weighted endorectal magnetic resonance imaging, and assessment of the potential of a computer-assisted segmentation technique to be translated to clinical practice for prostate cancer management. We collected an image data set from prostate cancer patients with manually-delineated prostate borders by one observer on all the images and by two other observers on a subset …