Biomedical Engineering and Bioengineering Commons^™

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 …

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 …

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 …

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 …

Mixed-Reality Visualization Environments To Facilitate Ultrasound-Guided Vascular Access, Leah Groves

Electronic Thesis and Dissertation Repository

Ultrasound-guided needle insertions at the site of the internal jugular vein (IJV) are routinely performed to access the central venous system. Ultrasound-guided insertions maintain high rates of carotid artery puncture, as clinicians rely on 2D information to perform a 3D procedure. The limitations of 2D ultrasound-guidance motivated the research question: “Do 3D ultrasound-based environments improve IJV needle insertion accuracy”. We addressed this by developing advanced surgical navigation systems based on tracked surgical tools and ultrasound with various visualizations. The point-to-line ultrasound calibration enables the use of tracked ultrasound. We automated the fiducial localization required for this calibration method such that …

4dct Analysis Of In-Vivo Carpal Kinematics During Fem, Manisha R. Mistry

Electronic Thesis and Dissertation Repository

A consensus, detailed understanding of carpal kinematics remains elusive. 4-dimensional CT (4DCT) is a validated modality capable of accurately studying in-vivokinematic motion. The objective of this work is to quantify normal, in-vivo kinematic motion of the carpus through a flexion-extension arc of motion using 4DCT. Ten healthy, un-injured volunteers underwent a 4DCT scanning protocol through a complete arc of flexion-extension motion. Kinematic changes in motion were quantified using helical axis motion data for each carpal bone. Helical axes were compared between bones and statistical analysis performed using repeated-measures ANOVA to identify difference in kinematic motion between bones (p<0.05). The carpus can be divided into four main kinematic blocks: the distal carpal block, the proximal carpal block and individual scaphoid and trapezial blocks. This work supports an additional segmentation of the trapezium from the distal carpal row, which suggests some modulation between the scaphoid and distal carpal row.

Development Of A Wireless Telemetry Load And Displacement Sensor For Orthopaedic Applications, William Anderson

Electronic Thesis and Dissertation Repository

Due to sensor size and supporting circuitry, in vivo load and deformation measurements are currently restricted to applications within larger orthopaedic implants. The objective of this thesis is to repurpose a commercially available low-power, miniature, wireless, telemetric, tire-pressure sensor (FXTH87) to measure load and deformation for future use in biomechanical applications. The capacitive transducer membrane of the FXTH87 was modified, and a relationship was reported between applied compressive deformation and sensor signal value. The sensor package was embedded within a deformable enclosure to illustrate potential applications of the sensor for monitoring load. Finite element analysis was an effective tool to …

4dct To Examine Carpal Motion, Sydney M. Robinson

Electronic Thesis and Dissertation Repository

Four-dimensional computed tomography (4DCT) is a novel imaging modality initially used in cardiac imaging but recently applied to the musculoskeletal system; although its methodology has been developed, it is still in its infancy as a powerful clinical tool. Currently, scapholunate interosseous ligament (SLIL) tears, whose early symptoms are elucidated through dynamic movement, are diagnosed with static techniques that cannot visualize dynamic motion; hence, a tool is needed that is responsive and dynamic to visualize subtle abnormal carpal movements indicative of SLIL tears. It is hypothesized that 4DCT can visualize subtle dynamic carpal movements to define uninjured motion as well as …

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 …

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 …

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 …

Using An Internal Auditory Stimulus To Activate The Developing Primary Auditory Cortex: A Fetal Fmri Study, Estee Goldberg

Electronic Thesis and Dissertation Repository

Insight into the rapidly developing brain in utero is scarce. Fetal functional magnetic resonance imaging (fMRI) is a technique used to gain awareness into the developmental process. Previous auditory task-based fMRI studies employed an external sound stimulus directly on the maternal abdomen. However, there has since been recommendation to cease doing so. We sought to investigate a reliable paradigm to study the development of fetal brain networks and postulate that by using an internal stimulus, such as the mother singing, it would result in activation of the fetal primary auditory cortex. Volunteers carrying singleton fetuses with a gestational age of …

A Framework For Evaluating Cortical Architectural Anomalies In Temporal Lobe Epilepsy Patients, Hossein Rajali

Electronic Thesis and Dissertation Repository

Focal cortical dysplasia (FCD) are localized regions of malformed cerebral cortex that are frequently associated with drug-resistant epilepsy. Currently, there is a lack of research towards providing quantitative methods for characterizing minor abnormalities in cortical architecture, hindering efforts to determine whether removal affects surgical outcome, and define potential imaging correlates. In our work, we have developed a tool to extract relevant features associated with cortical architectural abnormalities that can deal with artifacts including cortical layer distortions and morphological differences caused by cortical folding effects, and processing artifacts due to improper sectioning. This framework was applied to detect abnormalities across multiple …

Investigation Of Visual Perceptions In Parkinson's Disease And The Development Of Disease Monitoring Software, Matthew Bernardinis

Electronic Thesis and Dissertation Repository

Non-motor Parkinson’s Disease (PD) symptoms are substantial factors of PD arising throughout disease stages, yet their diagnosis and monitoring remain a challenge. Sensory abnormalities in PD occur across sensory systems and disease stages, contributing to disease-related impairments. However, the extent of symptoms is unknown, with inadequate monitoring and treatment options furthering disease management difficulties. The current work studies movement-independent visual perceptions of time, displacement and velocity in PD patients across disease stages using levodopa, deep brain stimulation (DBS), or no PD therapy. Perceptual tasks were conducted using a computer-generated graphical device designed with a focus on simplicity and flexibility. Perception …

Individual Variability Of Functional Connectivity In Resting-State And Naturalistic Fmri Paradigms, Mark O'Reilly

Electronic Thesis and Dissertation Repository

Resting-state functional magnetic resonance imaging (fMRI) studies are criticized for their lack of control over cognitive states of individuals during observation, which may lead to increased variability in estimates of functional connectivity (FC). Engaging movies have been used in an attempt to synchronize the cognitive states of individuals during the scan, potentially reducing intersubject variability in connectivity estimates. The objective of this study was to investigate the differences in intersubject variability of FC between rest and movie conditions in a healthy cohort. The results demonstrate widespread reductions of intersubject variability of FC in the movie condition compared to the resting-state …

Quantifying The Outcomes Of A Virtual Reality (Vr)-Based Gamified Neck Rehabilitation, Shahan Salim

Electronic Thesis and Dissertation Repository

Neck pain is a major global public health concern and adds a significant financial burden to both the healthcare system as well as people suffering from it. Additionally, it presents measurement and evaluation challenges for clinicians as well as adherence challenges and treatment barriers for the patients. We have developed a virtual reality (VR)-based video game that can be used to capture outcomes that may aid in the assessment and treatment of neck pain. We investigated: (i) performance metrics of overall accuracy, accuracy based on movement difficulty, duration, and total envelope of movement; (ii) stability across sessions; (iii) accuracy across …

Fabrication And Characterization Of Collagen-Polypyrrole Constructs Using Direct-Ink Write Additive Manufacturing, Rooshan Arshad

Electronic Thesis and Dissertation Repository

Current efforts in the tissue engineering field are being directed towards the creation of platforms which will facilitate in instructing cells towards biologically relevant outcomes such as stem cell differentiation and disease pathophysiology. Traditional fabrication methods serve as a limiting factor for the production of such platforms as they lack feature and geometric complexity. Additive Manufacturing (AM) offers advantage over said methods by affording designers creative freedom and great control over printed constructs. Such constructs can then be used to create appropriate models for study- ing a plethora of tissues and structures. An AM methodology for Direct-Ink Write (DIW) printing …

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 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 …

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 …

A Patient-Specific Cardiac Phantom For Training And Pre-Procedure Surgical Planning, Justin Laing

Electronic Thesis and Dissertation Repository

Minimally invasive cardiac procedures requiring a transseptal puncture are becoming increasingly common. For cases of complex or diseased anatomy, clinicians may benefit from using a patient-specific cardiac phantom for training, surgical planning, and the validation of devices or techniques.

An imaging compatible cardiac phantom was developed to simulate a MitraClip ® procedure. The phantom contained a patient-specific cardiac model manufactured using tissue mimicking materials.

To evaluate accuracy, the patient-specific model was imaged using CT, segmented, and the resulting point cloud data set was compared using absolute distance to the original patient data. The phantom was validated using a MitraClip ® …

The Effect Of Radial And Ulnar Length Change On Distal Forearm Loading, Ahaoiza D. Isa

Electronic Thesis and Dissertation Repository

The effect of distal radial and ulnar length change on forearm bone loading is not well understood during simulated dynamic wrist loading. This thesis presents two studies which investigate the effect of these length changes on distal forearm loading under simulated dynamic wrist motion. The first study investigates the effect of radial length change on axial loading at the distal radius and ulna and relationship between ulnar variance and distal forearm loading. The complex variation in axial loads in the distal radius and during length change and dynamic wrist motion were studied and discussed. There was no correlation between native …

Genetic Engineering Studies Of Escherichia Coli And Microalgae For Expression Of Hydrolytic Enzymes And Development Of High Throughput Screening Technique, Shreyas S. Yedahalli

Electronic Thesis and Dissertation Repository

The field of biochemical engineering has made substantial progress through major advances in genetic and metabolic engineering with applications in various sectors such as energy, food science, pharmaceuticals, etc. The hosts used for this work are constantly broadening. A host particularly important for energy applications are microalgae. The potential to enhance microalgae genetically for energy applications is not well explored and was therefore investigated in this thesis. Non-photosynthetic micro-organisms and photosynthetic microalgae offer a potential approach to enhance sustainable biochemical production. In this study expression vectors for Escherichia coli (E. coli) and Chlorella vulgaris (C. vulgaris) …

Histological Quantification In Temporal Lobe Epilepsy, Charlotte Anne Blinston

Electronic Thesis and Dissertation Repository

Approximately 30 percent of epilepsy patients suffer from refractory temporal lobe epilepsy which is commonly treated with resection of the epileptogenic tissue. However, surgical treatment presents many challenges in locating the epileptogenic focus and thus not all patients become seizure-free following surgery. Advances in techniques can lead to improved localization of the epileptogenic zone and may be validated by correlating MRI with neuropathology of the excised cortical tissue. Focal cortical dysplasias are a neuropathological group of cortical malformations that are often found in cases of refractory epilepsy, however, they are subtle and difficult to quantify. The purpose of this research …

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 …

Signal Processing Methods For Quantitative Power Doppler Microvascular Angiography, Mai H. Elfarnawany

Electronic Thesis and Dissertation Repository

Operator-dependent instrument settings and the likelihood of image artifacts are two challenges for reliably using three-dimensional (3-D) power Doppler angiography in flow depiction and quantification applications.

To address the operator-dependent settings challenge, an automated method for wall filter cut-off selection, the wall filter selection curve (WFSC) method, was developed using flow-phantom images. The flow-phantom WFSCs guided the development of a theoretical signal model relating color pixel density (CPD) and wall filter cut-off frequency. Simulations using the theoretical model were used to define criteria for the WFSC method to be applied to unprocessed power Doppler signals from 3-D vasculature. The adapted …

Characterization Of A Contact-Stylus Surface Digitization Method Using Collaborative Robots: Accuracy Evaluation In The Context Of Shoulder Replacement Or Resurfacing, Sara Saud Zimmo

Electronic Thesis and Dissertation Repository

Total shoulder arthroplasty (TSA) is the third most common joint replacement. While robot-assisted hip and knee replacement technologies have enjoyed extensive development, this has been limited in the upper limb. This work focused on quantifying the localization accuracy of a robotic system, and evaluating its efficacy in the context of TSA.

A collaborative robot was fitted with a stylus tip to perform manual surface digitizations using the robot’s encoder output. In the first experiment, two precision-machined master cubes, representing the working volume around a glenoid structure, were used for system validation. Next, cadaveric glenoids were digitized and compared to a …

Finite Element Modeling Of The Proximal Humerus To Compare Stemless, Short And Standard Stem Humeral Components Of Varying Material Stiffness For Shoulder Arthroplasty, Najmeh Razfar

Electronic Thesis and Dissertation Repository

In patients with debilitating pain due to osteoarthritis, total shoulder arthroplasty can restore function and provide effective pain relief. Newer implant designs vary in length and material stiffness. Unfortunately, literature on these newer implants is limited. This thesis investigates the effect of stem length and implant material stiffness on proximal humeral bone stresses. 3D bone models with implants of various stem lengths (stemless, short, and standard) and different material stiffness’s (CoCr, Ti and PEEK) were generated using MIMICS, Solidworks and ABAQUS for varying abduction angles (15°, 45° and 75°). Cortical and trabecular stresses were contrasted with the intact bone state. …

Visual Perception And Cognition In Image-Guided Intervention, Kamyar Abhari

Electronic Thesis and Dissertation Repository

Surgical image visualization and interaction systems can dramatically affect the efficacy and efficiency of surgical training, planning, and interventions. This is even more profound in the case of minimally-invasive surgery where restricted access to the operative field in conjunction with limited field of view necessitate a visualization medium to provide patient-specific information at any given moment. Unfortunately, little research has been devoted to studying human factors associated with medical image displays and the need for a robust, intuitive visualization and interaction interfaces has remained largely unfulfilled to this day. Failure to engineer efficient medical solutions and design intuitive visualization interfaces …