Biomedical Engineering and Bioengineering Commons^™

A Longitudinal Study Of Achilles Tendon Adaptation In Ncaa Division I Female Gymnasts: Associations With Menstrual Status, Birth Control Use, Pain, Limb Dominance, And Training Exposure, Mattie Jane Hyde

Electronic Theses and Dissertations

This longitudinal study evaluated Achilles tendon (AT) thickness in 22 NCAA Division I (DI) female gymnasts across three consecutive seasons in relation to menstruation, birth control use, pain, limb dominance, training week, and year of collegiate competition. Weekly ultrasound and athlete survey data were analyzed using mixed-effects models for absolute AT thickness and change in thickness from baseline measurements. Associations were primarily characterized by interactions rather than uniform effects of individual predictors. A Pain × Limb Dominance × Week × Year interaction was associated with both thickness outcomes across season-specific and combined analyses, with relationship directions varying by limb, season …

An Investigation Of Pelvic Kinematics And Implications For Total Hip Arthroplasty, Kathryn Holland Colone

Electronic Theses and Dissertations

Total hip arthroplasty (THA) is one of the most commonly performed orthopaedic procedures, with approximately 500,000 surgeries performed annually in the United States alone. Although THA is widely regarded as highly successful, postoperative complications persist, highlighting the multifactorial nature of THA outcomes. Previous studies have demonstrated the importance of implant positioning and soft tissue mechanics, yet challenges remain in optimizing surgical decisions on a patient-specific basis. Recent advances in surgical planning tools have shifted the focus of preoperative planning toward optimizing patient-specific outcomes, highlighting the need to better understand how patient anatomy, surgical technique, and joint mechanics interact to influence …

Accuracy Of Glenohumeral Joint Center Of Rotation Estimates Using Traditional Motion Capture Versus Bi-Plane Fluoroscopy, Julia A. Dunn, Ola Alsaadi, Kevin Shelburne, Michelle B. Sabick

Mechanical and Materials Engineering: Faculty Scholarship

Accurate estimation of the glenohumeral joint center of rotation is critical for biomechanical modeling of shoulder motion. This study evaluated the accuracy of three predictive methods for estimating glenohumeral joint center of rotation using optical motion capture, compared against a benchmark derived from synchronous bi-plane fluoroscopy. Five healthy adults performed shoulder abduction, flexion, and external rotation in 90° abducted and adducted positions. Root mean square error and axial errors were calculated across the full range of motion. Results showed that none of the predictive methods met clinically acceptable thresholds, with absolute error exceeding 10 mm and axial errors surpassing ±5 …

Mechanisms Of Correlated Neuronal Activity In The Globus Pallidus, Hamza Albawaliz

Electronic Theses and Dissertations

This thesis investigates the mechanisms of correlated neuronal activity in the globus pallidus externus (GPe), a key structure in the basal ganglia. Neuronal activity in the GPe is reportedly decorrelated in healthy subjects but can become highly correlated in Parkinson’s disease. However, high-density neuronal recordings in the GPe of healthy rats reveal a surprising degree of correlated activity. This raises the question of whether intrinsic properties or network connectivity alone can account for such patterns. To explore this, a computational model was developed in which GPe neurons are represented as coupled phase oscillators influenced by experimentally derived phase-response curves and …

Development Of A Non-Faradaic Impedimetric Biosensor Based On Reduced Graphene Oxide For The Detection Of Brain-Derived Neurotrophic Factor (Bdnf), Mariana N. Martins

Electronic Theses and Dissertations

Neurological disorders affect millions of people worldwide. In the case of Alzheimer’s disease (AD), the rising number of cases significantly increases global healthcare costs. Therefore, early detection of biomarkers at the onset of the disease is essential for early diagnosis. This study presents an electrochemical biosensor designed for the detection of Brain-Derived Neurotrophic Factor (BDNF) in human plasma, incorporating reduced graphene oxide (rGO) to enhance signal sensitivity. Dielectrophoresis (DEP) was employed to deposit rGO flakes on the electrode surface, improving conductivity and sensor performance. Electrochemical impedance spectroscopy (EIS) was used to monitor changes in impedance associated with BDNF binding events, …

Reproducibility In Modeling Of Knee Joint Mechanics, Maryam Nazem

Electronic Theses and Dissertations

Computational modeling of knee joint biomechanics can provide valuable insights into joint function, injury mechanisms, and patient outcomes, and can support surgical planning and informed clinical decision-making. However, achieving consistent and repeatable results, or reproducibility, is a significant challenge that affects the credibility of these models. This thesis addresses reproducibility through two studies related to the KneeHub Project, which is a multi-institutional collaboration designed to investigate reproducibility in finite-element modeling of the knee.

The first study involved model benchmarking, where predicted results of the calibrated models were compared with the experimental data to evaluate model reproducibility. While all models replicated …

Developing Deep Learning Methods For Cognitive Impairment Detection Based On Non-Invasive Data, Muath Alsuhaibani

Electronic Theses and Dissertations

Cognitive impairment detection is on the rise to help reduce the burden of healthcare costs on institutions and individuals. Mild Cognitive Impairment (MCI) is an early stage of cognitive decline progressing to Alzheimer’s disease (AD) or AD-related Dementia (ADRD). Detecting the early stages of AD/ADRD is crucial for early interventions among older adults to mitigate cognitive decline over time. However, the current diagnostic methods are often costly and/or invasive, such as MRI and PET scans. Thus, the search for non-invasive and cost-effective screening tools for the early detection of cognitive impairment using speech, language, visual, and motor data is growing. …

Surgeon Ergonomics While Performing Total Knee Arthroplasty, Cameron Dahman

Electronic Theses and Dissertations

One of the most prevalent hazards to orthopedic surgeons are musculoskeletal disorders with 97% of arthroplasty surgeons reporting procedural-related musculoskeletal pain and 66% of orthopedic surgeons reporting procedural-related musculoskeletal injury [1], [2], [3]. With the annual number of total knee arthroplasties (TKA) on the rise, orthopedic surgeons are taking on larger annual caseloads and retiring later in life [4], [5]. The goal of this study was to quantify postural demand for 11 discrete surgical steps of TKA to identify ergonomically unfavorable positions surgeons experience while operating. Four orthopedic surgeons performed TKA while their motions were recorded using marker-based motion capture. …

Influence Of Obesity On Knee Joint Mechanics: A Subject-Specific Musculoskeletal Modeling Approach, Ryan C. Knowles

Electronic Theses and Dissertations

Obesity has been consistently linked to knee osteoarthritis (KOA), a debilitating joint disease. While prior work has shown that obese individuals often walk with altered biomechanics compared to normal-weight (NW) individuals, which may accelerate KOA progression, less is known about how these mechanics affect load distribution between the medial and lateral tibiofemoral (TF) compartments, particularly during higher-demand activities. This study developed subject-specific musculoskeletal models of five obese and five NW individuals, incorporating CT-based bone measurements and individualized joint contact points. Simulations were driven by six degree-of-freedom (6DOF) kinematics obtained from high-speed stereo radiography (HSSR) to predict TF loading and associated …

Computational Fluid Dynamics And Fluid Structure Interaction Modeling In Healthy Vertebral Arteries: A Comparative Study, Bryce Clinkenbeard

Electronic Theses and Dissertations

Cerebral perfusion is critical for maintaining proper brain function, with each cerebrovascular artery playing an integral role in the overall cerebrovascular system. When these arteries become damaged or develop plaque, cardiovascular disease (CVDs) such as atherosclerosis can arise, leading to conditions like arterial stenosis. While CVDs are most prevalent in older individuals, they are also observed in young adults, particularly those engaged in high-endurance occupations such as military service. Diagnosis and prediction of CVDs often rely on imaging modalities supported by computational fluid dynamics (CFD) which account for low resolution in fluid flow. CFD models assume rigid arterial walls, which …

Development, Optimization, And Validation Of A High-Sensitivity Capillary Zone Electrophoresis System For Bioanalytical Applications, Aaron I. Mena

Electronic Theses and Dissertations

Capillary zone electrophoresis (CZE) is a powerful analytical technique widely used for biomolecular separation due to its high resolution, efficiency, and sensitivity. This report presents the development and validation of a novel CZE system designed to improve modularity, reproducibility, and operational efficiency. The system integrates a laser-induced fluorescence (LIF) detection method with a 488 nm laser, enhanced fluid control through a negative pressure system, and a user-friendly GUI for automated operation and data acquisition. Performance verification included pressure stability tests, fluorescence accuracy assessments, and electrophoretic reproducibility studies. Comparative analysis with a previous CZE iteration confirmed improved baseline stability, peak resolution, …

Advancing Tka Biomechanics: From Joint Simulator To Boundary Condition Development, Yashar Ali Behnam

Electronic Theses and Dissertations

This dissertation addresses four specific aims that collectively attempted to advance the experimental and computational analysis of total knee arthroplasty (TKA) components. The first study focused on the development of a novel whole knee joint simulator capable of simultaneous tibiofemoral and patellofemoral knee loading. This simulator employs custom fixturing to facilitate dynamic, unconstrained, muscle-driven PF articulation alongside controlled TF contact mechanics. Validation against experimental measurements showed strong agreement, demonstrating the simulator's potential as a valuable tool for future TKA design and surgical technique investigations.

The second study verified implant-specific physiological boundary conditions which accurately simulate activities of daily living using …

Determinants Of Knee Motion In Health, Disease, And Repair, Sean Edward Higinbotham

Electronic Theses and Dissertations

The human knee joint is a complex and intricate structure, enabling a wide range of motions and facilitating various dynamic activities throughout a person's lifetime. The combination of the knee's complexity and its role as a primary load-bearing joint has made it susceptible to regular wear and tear, leading to pain and the development of Osteoarthritis (OA), to which, the only treatment currently is total knee arthroplasty (TKA). Despite TKA being a mature procedure, 20% of patients receiving a TKA are dissatisfied with their “new” knee. To reduce that 20% dissatisfaction and improve surgical outcomes, orthopedic companies are developing advanced …

The Impact Of Cumulative And Acute Loading On Achilles Tendon Health, Performance, And Reported Pain In Collegiate Gymnasts, Julio Serrano Samayoa

Electronic Theses and Dissertations

Gymnasts are at a high risk of Achilles tendon (AT) injuries due to intense loads during takeoffs and landings. To better understand better the relationship between impact loading and its effects on tendon adaptation and athletic performance, this study uses Inertial Measurement Units (IMUs) to track AT loading across a collegiate gymnastics season. This data were compared against physiological and athletic performance metrics, obtained through force plates and ultrasound imaging, to explore how mechanical load influences reported pain and athletic performance. Results varied, with cumulative impacts being correlated with improved jump height (Spearman 0.362, Pearson 0.348), while peak power and …

Applications Of Computer Vision In Biomechanics And Orthopaedics, William Stewart Burton Ii

Electronic Theses and Dissertations

Machine learning has emerged as a key technology for enabling advanced computer vision systems. These systems now permeate many industries, and have enhanced traditional processes through autonomous interpretation of visual data. In the field of orthopaedics, the increasing prevalence of imaging highlights a need for similar tools. In many cases, however, direct translation of available frameworks fails to resolve the complex problems currently facing this field. Stringent performance requirements, complex visual environments, data scarcity, and implications for patient safety represent domain-specific factors which pose unique challenges to proven techniques. Novel approaches are needed to realize the full benefits of visual …

Patient-Specific Musculoskeletal Modeling Of Total Shoulder Arthroplasty, Brendan M. Curran

Electronic Theses and Dissertations

Total shoulder arthroplasty (TSA) is often considered a surgery of last resort for patients with debilitating pathologies of the glenohumeral joint such as osteoarthritis, humeral head fracture, and advancing rotator cuff tears. TSA replaces the articulation between the humeral head and the glenoid fossa, with the goals of relieving pain and restoring function. Two types of total shoulder implants are available: Anatomic Total Shoulder Arthroplasty (aTSA) and Reverse Total Shoulder Arthroplasty (rTSA). TSA survivorship is lower than that of the survivorship seen in total knee and hip replacements [1]. Shoulder muscle moment arms and lines of action have been measured …

Statistical Modeling Of Knee Morphology And Material Properties Considering Diverse Populations, Gabrielle Jeannine Kindy

Electronic Theses and Dissertations

Total Knee Arthroplasty (TKA) is a widely performed surgical procedure aimed at alleviating pain and restoring function in patients with severe knee osteoarthritis. Despite its general success, disparities in postoperative outcomes have been observed across different racial and ethnic groups, with minority populations often experiencing less favorable results. One potential avenue for improving the generalizability of orthopaedic implants is using Statistical Shape and Intensity Models (SSIMs), which can be used to incorporate patient variability directly into the orthopaedic medical device development workflow through population-based finite element analysis.

This work aimed to construct an SSIM from a diverse subject set, incorporating …

Simultaneous Evaluation Of Tibiofemoral And Patellofemoral Mechanics In Total Knee Arthroplasty: A Combined Experimental And Computational Approach, Yashar A. Behnam, Ahilan Anantha Krishnan, Hayden Wilson, Chadd W. Clary

Center for Orthopaedic Biomechanics: Faculty Scholarship

Contemporary total knee arthroplasty (TKA) has not fully restored natural patellofemoral (P-F) mechanics across the patient population. Previous experimental simulations have been limited in their ability to create dynamic, unconstrained, muscle-driven P-F articulation while simultaneously controlling tibiofemoral (T-F) contact mechanics. The purpose of this study was to develop a novel experimental simulation and validate a corresponding finite element model to evaluate T-F and P-F mechanics. A commercially available wear simulator was retrofitted with custom fixturing to evaluate whole-knee TKA mechanics with varying patella heights during a simulated deep knee bend. A corresponding dynamic finite element model was developed to validate …

Digital Twins Of The Living Knee: From Measurements To Model, Thor Erik Andreassen

Electronic Theses and Dissertations

Modern medicine has dramatically improved the lives of many. In orthopaedics, robotic surgery has given clinicians superior accuracy when performing interventions over conventional methods. Nevertheless, while these and many other methods are available to ensure treatments are performed successfully, far fewer methods exist to predict the proper treatment option for a given person. Clinicians are forced to categorize individuals, choosing the best treatment on “average.” However, many individuals differ significantly from the “average” person, for which many of these treatments are designed. Going forward, a method of testing, evaluating, and predicting different treatment options' short- and long-term effects on an …

Kinematic Analysis Of Gait And Deep Knee Flexion For Pre- And Post-Operative Total Knee Arthroplasty, Samantha Collins

Electronic Theses and Dissertations

Osteoarthritis (OA) is a form of arthritis that develops in the joint due to overuse and aging causing pain, discomfort, and disability. Total Knee Arthroplasty (TKA) is a surgical procedure performed when OA symptoms are severe with an estimated 600,000 patients in the United States currently receiving TKA. Studies have reported dissatisfaction of the knee for 14-39% of patients. This study collected knee kinematics before and after surgery using stereo radiography for precise measurement of gait and deep knee flexion activities. Results showed healthy knee kinematics were not restored and no significant changes could be seen from OA kinematics in …

Computational Methodology For Generating Patient-Specific Soft Tissue Representations, Ahilan Anantha Krishnan

Electronic Theses and Dissertations

This dissertation focused on modeling specimen-specific soft tissue structures in the context of joint replacement surgery. The research addressed four key aspects. The first study involved developing a workflow for creating finite element models of the hip capsule to replicate its torque-rotational response. Experimental data from ten cadaveric hips were used to calibrate the models, resulting in improved accuracy and relevance for surgical planning and implant design. The second study tackled the challenge of expediting the calibration of mechanical properties of the hip capsule to match patient-specific laxities. A statistical shape function model was proposed to generate patient-specific finite element …

Exploration Of Motion Capture System To Investigate Human Shoulder Kinematics, Ola Alsaadi

Electronic Theses and Dissertations

The glenohumeral joint (GH) is commonly conceptualized as a ball-and-socket joint [1], and its center of rotation (COR) is presumed to coincide with the geometric center of the medial-superior region of the humeral head [2]. Recent research has endorsed improvements in COR estimation through invasive and noninvasive techniques, including cadaver studies, stereophotogrammetry, and motion capture (MOCAP) systems. Despite increased interest in wearable technology within human movement analysis, the problem of COR estimation employing MOCAP systems and its validation against bi-planar fluoroscopy remains relatively unexplored.

This study employed a marker-based MOCAP system to compare the accuracy, error, and precision of three …

Hemodynamic Assessment Of Y-Incision Aortic Root Enlargement Using Computational Simulations, Astitwa Ghimire

Electronic Theses and Dissertations

The Yang procedure is a new aortic root enlargement technique used to enlarge the aortic annulus by multiple valve sizes. The procedure prevents patient prosthesis mismatch and establishes a viable platform for future valve-in-valve implantation. This study used the Yang procedure to investigate the hemodynamics in the aortic root and bioprosthetic valve regions after aortic root enlargement. Results indicate the velocity magnitude at the sinus regions of a patient who underwent the Yang procedure was slower, indicating risks of flow stasis and thrombosis. Simulation results denote computational models can be created for optimization of surgical procedures.

A Virtual Method For Establishing Femoral Stem Position In Total Hip Arthroplasty, Samuel Mattei

Electronic Theses and Dissertations

Total hip arthroplasty (THA) is one of the most successful orthopedic surgeries performed, in which the hip joint is reconstructed to improve functionality and decrease pain in the joint. Despite the success of these procedures, femoral stem misalignment remains an area that influences THA success. The relationship between the femoral stem geometry and implanted femoral stem size and orientation is underreported due to limitations in the collection of radiographic data used for clinical pre-operative templating. Furthermore, the influence of anatomic measurements on the direction and size of the femoral stem are not considered due to imaging technique and difficulties associated …

Finite Element Modeling Of Patient-Specific Total Shoulder Arthroplasty, Ignacio Rivero Crespo

Electronic Theses and Dissertations

Total Shoulder Arthroplasty (TSA) is a surgical procedure designed to improve joint functionality by replacing the articulation between the humeral head and the glenoid fossa. Anatomic Total Shoulder Arthroplasty (aTSA) and Reverse Total Shoulder Arthroplasty (rTSA) are two types of replacement surgery to relieve pain and restore function of the shoulder. The overall goal of this study was to evaluate the effects of variation of certain patient and implant alignment parameters that may influence long-term outcomes of these surgical procedures, including kinematics, joint loads and contact mechanics. Computational models of six TSA subjects, three aTSA and three rTSA, were created …

Fully Coupled Fluid Structure Interaction Simulation Of Bioprosthetic Heart Valves: A Numerical And Experimental Analysis, Masod Sadipour

Electronic Theses and Dissertations

Aortic stenosis impacts approximately 7% of the global population. In the past decade, the role of computational modeling has been becoming considerably important in the design of BHVs. To obtain reliable solutions in computational modeling, it is essential to consider accurate properties of bioprosthetic heart valves (BHVs), such as density and mechanical properties. Previous computational studies assumed (bovine pericardium) BP used in BHVs density was comparable to water or blood. Yet, BP is subjected to multiple treatments like fixation and anti-calcification. In Chapter 2, I measured BP density and its effect on BHV leaflet stress and strain. In the second …

Patient Movement Monitoring Based On Imu And Deep Learning, Mohsen Sharifi Renani

Electronic Theses and Dissertations

Osteoarthritis (OA) is the leading cause of disability among the aging population in the United States and is frequently treated by replacing deteriorated joints with metal and plastic components. Developing better quantitative measures of movement quality to track patients longitudinally in their own homes would enable personalized treatment plans and hasten the advancement of promising new interventions. Wearable sensors and machine learning used to quantify patient movement could revolutionize the diagnosis and treatment of movement disorders. The purpose of this dissertation was to overcome technical challenges associated with the use of wearable sensors, specifically Inertial Measurement Units (IMUs), as a …

Improving Quantification Of Mitral Regurgitation Through Computational Fluid Dynamics And Ex Vivo Testing, Alexandra Flowers

Electronic Theses and Dissertations

Mitral regurgitation (MR) is a prominent cardiac disease affecting more than two million people in the United States alone. In order for patients to receive proper therapy, regurgitant volume must first be quantified. As there are an array of methods to do so, the proximal isovelocity surface area (PISA) method continues to be the most accurate and clinically used method. However, there are some difficulties obtaining the necessary measurements need for this when performing transthoracic echocardiography. This study aims to evaluate and present techniques that may be used to more accurately quantify regurgitation through ex vivo testing and computational fluid …

Structural And Hemodynamic Analysis Of Transcatheter Aortic Valves, Dong Qiu

Electronic Theses and Dissertations

The transcatheter aortic valve replacement (TAVR) procedure has become a well-established procedure for high, intermediate-risk, and low-risk patients. However, there is limited clinical data on the TAV's long-term durability, unlike SAV devices. Computational simulations can be an alternative way to evaluate the TAV devices. This dissertation aims to conduct structural and hemodynamic analyses on the TAV devices under different conditions using computational simulation approaches.

Initially, the impact of the bicuspid aortic valve on the TAV devices was evaluated. The result indicated that the CoreValve-like supra-annular self-expandable device was likely to have increased stress and strain on the leaflet when it …

Pulmonary Valve Replacement, Mina Shafiei

Electronic Theses and Dissertations

Currently, transcatheter pulmonary valve replacement (TPVR) is a well-established alternative for surgical pulmonary valve replacement (SPVR) to treat pulmonary valve disorders in patients with prior congenital heart surgery. Edwards Sapien 3 valve is a bioprosthesis originally designed for the aortic position but has been used off-label in native right ventricular outflow tract (RVOT). It is currently under clinical trial to get food and drug administration (FDA) approval.

This study is a comparison of the performance of Sapien 3 with surgical bioprosthetics. The in vitro tests result showed Sapien 3 experiences less degree of opening and effective orifice area in pulmonic …