Biomedical Engineering and Bioengineering Commons^™

An Immersed Boundary Geometric Preprocessor For Arbitrarily Complex Terrain And Geometry, Inanc Senocak, Micah Sandusky, Rey Deleon, Derek Wade, Kyle Felzien, Marianna Budnikova

Mechanical and Biomedical Engineering Faculty Publications and Presentations

There is a growing interest to apply the immersed boundary method to compute wind fields over arbitrarily complex terrain. The computer implementation of an immersed boundary module into an existing flow solver can be accomplished with minor modifications to the rest of the computer program. However, a versatile preprocessor is needed at the first place to extract the essential geometric information pertinent to the immersion of an arbitrarily complex terrain inside a 3D Cartesian mesh. Errors in the geometric information can negatively impact the correct implementation of the immersed boundary method as part of the solution algorithm. Additionally, the distance …

Indentation Probing Of In Vitro Bovine Articular Cartilage: Effects On Chondrocyte Viability And Tissue Biomechanics, Pablo F. Argote, Alan Poon, Xin Xu Ph.D, Corey P. Neu Ph.D.

The Summer Undergraduate Research Fellowship (SURF) Symposium

Osteoarthritis (OA) consists of a degenerative disease on articular cartilage, which is prone to excessive mechanical loading and frictional resistance that leads to the wear and tear of the tissue. These factors result in the progressive and incurable disease that affects millions of people worldwide. The goal is to characterize chondrocyte viability and the in vitro biomechanical properties of articular cartilage in two confined indentation studies. One study looks at the chondrocyte viability over seven days. The second compares the immediate effects of strain rates on chondrocyte viability and tissue biomechanics. Bovine cartilage explants are harvested, cultured, and then 40% …

A Community Of World Class Engineering Students, Devshikha Bose, Krishna Pakala

Mechanical and Biomedical Engineering Faculty Publications and Presentations

This paper is a work in progress report on an Engineering Living Learning Community (LLC) at Boise State University. Though the LLC under consideration is for the time period of Fall 2014 to Fall 2016, this report is limited to student as well as instructor anecdotal and self-reported experiences, observations, and evaluations made during Fall 2014 and Spring 2015. The mission of the Residential College program at BSU is to integrate student academic and personal life in a residential setting, so as to develop interdisciplinary knowledge, foster deep learning, and maximize student success. In support of this goal, students completed …

Synergy-Based Two-Level Optimization For Predicting Knee Contact Forces During Walking, Gil Serrancolí, Allison Kinney, Josep M. Font-Llagunes, Benjamin J. Fregly

Mechanical and Aerospace Engineering Faculty Publications

Musculoskeletal models and optimization methods are combined to calculate muscle forces. Some model parameters cannot be experimentally measured due to the invasiveness, such as the muscle moment arms or the muscle and tendon lengths. Moreover, other parameters used in the optimization, such as the muscle synergy components, can be also unknown. The estimation of all these parameters needs to be validated to obtain physiologically consistent results. In this study, a two-step optimization problem was formulated to predict both muscle and knee contact forces of a subject wearing an instrumented knee prosthesis. In the outer level, muscle parameters were calibrated, whereas …

Development Of A Muscle Model Parameter Calibration Method Via Passive Muscle Force Minimization, Allison Kinney, Benjamin J. Fregly

Mechanical and Aerospace Engineering Faculty Publications

Computational predictions of subject-specific muscle and knee joint contact forces during walking may improve individual rehabilitation treatment design. Such predictions depend directly on specified model parameter values. However, model parameters are difficult to measure non-invasively. Methods for muscle model parameter calibration have been developed previously. However, it is currently unknown how the musculoskeletal system chooses muscle model parameter values. Previous studies have hypothesized that muscles avoid injury during walking by generating little passive force and operating in the ascending region of the force-length curve. This hypothesis suggests that muscle model parameter values may be selected by the body to minimize …

Computational Prediction Of Remodeling Of Collagen Fiber Network In Articular Cartilage Under Dynamic Unconfined Compression, Juan Andres Coello Amado

Theses and Dissertations - UTB/UTPA

A poroelastic finite element model of a heterogeneous cartilage disk was created based on previous studies and experimental setups; this allows us to study cartilage behavior under dynamic unconfined compression. Previous studies have used a Post Hoc approach, which consist of searching for patterns or relationships between predicted mechanical parameters obtained through computational and experimental results. Our goal in this study is to take the same Post-Hoc approach and identify patterns between predicted mechanical parameters, such as fiber strain or stress, and experimentally-measured collagen fiber distribution (i.e. reorientation of fibers under dynamic unconfined compression). After computational predictions were obtained, it …

Nano Scale Mechanical Analysis Of Biomaterials Using Atomic Force Microscopy, Diganta Dutta

Mechanical & Aerospace Engineering Theses & Dissertations

The atomic force microscope (AFM) is a probe-based microscope that uses nanoscale and structural imaging where high resolution is desired. AFM has also been used in mechanical, electrical, and thermal engineering applications. This unique technique provides vital local material properties like the modulus of elasticity, hardness, surface potential, Hamaker constant, and the surface charge density from force versus displacement curve. Therefore, AFM was used to measure both the diameter and mechanical properties of the collagen nanostraws in human costal cartilage. Human costal cartilage forms a bridge between the sternum and bony ribs. The chest wall of some humans is deformed …

Use Of Mobile Learning Strategies And Devices For E-Portfolio Content Creation In An Engineering Thermodynamics And Fluid Mechanics Classes: Student Perceptions, Devshikha Bose, Krishna Pakala

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Use of mobile learning strategies and devices for e-portfolio content creation in an engineering Thermodynamics class: Student perceptions Mobile devices can be useful for creating educational content and to help students to learn better (Benedict & Pence, 2012; Tabor & Minch, 2013; Pereira, Echeazarra, Sanz-Santamaria, & Gutierrez, 2014). The purpose of this study is to determine student perceptions on the efficacy of using mobile learning strategies and devices to create electronic content for inclusion in an engineering individual e-portfolio. Students enrolled in an undergraduate 300-level engineering Thermodynamics class, created multimedia videos and produced content demonstrating course content summaries, problem solving …

Sapien3 Comb Stitch Improvement For Edwards Lifesciences, William Harley, Thomas Pluschkell, John Mctigue, Garrett Reed

Mechanical Engineering

The complete senior project report was submitted to the project advisor and sponsor. The results of this project are of a confidential nature and will not be published at this time.

Transcatheter Heart Valve Subassembly Device, Adam Aslam, Matthew Bezkrovny, Daniel Degree

Mechanical Engineering

No abstract provided.

The Influence Of Neuromusculoskeletal Model Calibration Method On Predicted Knee Contact Forces During Walking, Gil Serrancolí, Allison Kinney, Benjamin J. Fregly, Josep M. Font-Llagunes

Mechanical and Aerospace Engineering Faculty Publications

This study explored the influence of three model calibration methods on predicted knee contact and leg muscle forces during walking. Static optimization was used to calculate muscle activations for all three methods. Approach A used muscle-tendon model parameter values (i.e., optimal muscle fiber lengths and tendon slack lengths) taken directly from literature. Approach B used a simple algorithm to calibrate muscle-tendon model parameter values such that each muscle operated within the ascending region of its normalized force-length curve. Approach C used a novel two-level optimization procedure to calibrate muscle-tendon, moment arm, and neural control model parameter values while simultaneously predicting …

Development And Validation Of A Tibiofemoral Joint Finite Element Model And Subsequent Gait Analysis Of Intact Acl And Acl Deficient Individuals, Nicholas Czapla

Master's Theses

Osteoarthritis (OA) is a degenerative condition of articular cartilage that affects more than 25 million people in the US. Joint injuries, like anterior cruciate ligament (ACL) tears, can lead to OA due to a change in articular cartilage loading. Gait analysis combined with knee joint finite element modeling (FEM) has been used to predict the articular cartilage loading. To predict the change of articular cartilage loading during gait due to various ACL injuries, a tibiofemoral FEM was developed from magnetic resonance images (MRIs) of a 33 year male, with no prior history of knee injuries. The FEM was validated for …

Computational Fluid Dynamics Applied To The Analysis Of Blood Flow Through Central Aortic To Pulmonary Artery Shunts, Carey Celestin Jr

LSU New Orleans Theses and Dissertations

This research utilizes CFD to analyze blood flow through pathways representative of central shunts, commonly used as part of the Fontan procedure to treat cyanotic heart disease. In the first part of this research, a parametric study of steady, Newtonian blood flow through parabolic pathways was performed to demonstrate the effect that flow pathway curvature has on wall shear stress distribution and flow energy losses. In the second part, blood flow through two shunts obtained via biplane angiograms is simulated. Pressure boundary conditions were obtained via catheterization. Results showed that wall shear stresses were of sufficient magnitude to initiate platelet …

Towards A Dynamic Clamp For Neurochemical Modalities, C. M. Rivera, H.-J. Kwon, A. Hashmi, Gu Yu, J. Zhao, J. Gao, J. Xu, Wei Xue, A. G. Dimitrov

Henry M. Rowan College of Engineering Departmental Research

The classic dynamic clamp technique uses a real-time electrical interface between living cells and neural simulations in order to investigate hypotheses about neural function and structure. One of the acknowledged drawbacks of that technique is the limited control of the cells’ chemical microenvironment. In this manuscript, we use a novel combination of nanosensor and microfluidic technology and microfluidic and neural simulations to add sensing and control of chemical concentrations to the dynamic clamp technique. Specifically, we use a microfluidic lab-on-a-chip to generate distinct chemical concentration gradients (ions or neuromodulators), to register the concentrations with embedded nanosensors and use the processed …

Characterization And Evaluation Of Head Impact Sensors And Varsity Football Helmets, Brian R. Cummiskey

Open Access Theses

An increased understanding of the effects of brain injury in recent years has led to greater attention being given to the topic. A desire to investigate the causal agents of these injuries in athletes has led to the development and use of several devices that track head impacts as well as improving helmet technology to protect players from said impacts. In order to determine which devices are able to best measure head impacts, a Hybrid III headform was used to quantify the accuracy for translational and angular accelerations. Testing was performed by means of administering impacts to a helmet on …

Freezing-Induced Deformation Of Biomaterials In Cryomedicine, Altug Ozcelikkale

Open Access Dissertations

Cryomedicine utilizes low temperature treatments of biological proteins, cells and tissues for cryopreservation, materials processing and cryotherapy. Lack of proper understanding of cryodamage that occurs during these applications remains to be the primary bottleneck for development of successful tissue cryopreservation and cryosurgery procedures. An engineering approach based on a view of biological systems as functional biomaterials can help identify, predict and control the primary cryodamage mechanisms by developing an understanding of underlying freezing-induced biophysical processes. In particular, freezing constitutes the main structural/mechanical origin of cryodamage and results in significant deformation of biomaterials at multiple length scales. Understanding of these freezing-induced …

A Three Constituent Mixture Theory Model Of Cutaneous And Subcutaneous Tissue In The Context Of Neonatal Pressure Ulcer Etiology And Prevention, Anne Dye Zakrajsek

Open Access Dissertations

Localized ischemia, impaired interstitial fluid flow, and sustained mechanical loading of cells have all been hypothesized as mechanisms of pressure ulcer (PrU) etiology. Time-varying loading has experimentally been shown to increase fluid flow in human skin in vivo. Towards the design of prophylactic protocols and treatment modalities for PrU management there is a need for an analytical model to investigate the local fluid flow characteristics of skin tissue under time-varying loading. In this study, a triphasic mixture theory model with constituents of extracellular matrix, interstitial fluid, and blood was calibrated and validated and used to investigate stress and fluid velocity …

Contact Analysis For Coupling Of Plates And Screws In Fracture Fixation Of Cortical Bone, Gaffar Gailani, Rachid Moumni, Malek Brahimi

Publications and Research

Internal fixation is a common treatment for bone fracture. Bone fracture occurs due to different reasons such as motor vehicle accidents, falling,…etc. The treatment is performed by fixing plate and screws to the fracture site. Lack of stability of the implants (plates and screws) may lead to delay in healing or failure of treatment. Micro-motion between the implant and the bone may cause formation of fibrous tissue around the screw which will lead to implant loosening. On the other hands, firm fixing of the conventional implants (Dynamic Compression Plates) may lead to delay resorption and delay in healing. Recently, Locked …

Stethoscope-Based Detection Of Detorqued Bolts Using Impact-Induced Acoustic Emissions, Joe Guarino, Robert Hamilton

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Results of a preliminary study investigating a simple method for detecting looseness in bolted fasteners of a steel structure are presented. Extensive research by many investigators demonstrates that the frequency response of a bolted structural member changes when one or more bolts are loosened. A simple and effective method for detecting looseness can be applied to bolted joints, using inexpensive and commonly-available equipment and software. The difference between spectrograms associated with tight and loose bolts is clearly apparent due to the presence of a tell-tale mode when one or more bolts are loosened. Further, a striking difference can be elucidated …

A Multi-Directional Treadmill Training Program For Improving Gait, Balance, And Mobility In Individuals With Parkinson’S Disease: A Case Series, Kimberly Smith, Kurt Jackson, Kimberly Edginton Bigelow, Lloyd L. Laubach

Mechanical and Aerospace Engineering Faculty Publications

Treadmill training is a commonly used intervention for improving gait in people with Parkinson’s disease (PD). However, little is known about how treadmill training may also influence balance and other aspects of mobility.

The purpose of this case series was to explore the feasibility and possible benefits of multi-directional treadmill training for individuals with PD. Four participants (62.3 ± 6.5 yrs, Hoehn & Yahr 2-4) performed 8 weeks of treadmill training 3 times per week. Weeks 1-4 included forward walking only, while weeks 5-8 included forward and multi-directional walking. Participants were tested every 4 weeks on 4 separate occasions. Outcome …

Selective Laser Sintering Of Bioactive Glass Scaffolds And Their Biological Assessment For Bone Repair, Krishna C. R. Kolan

Doctoral Dissertations

"Bone scaffold fabrication using powder-bed based additive manufacturing techniques, like the selective laser sintering (SLS) process, provides control over pore interconnectivity, pore geometry, and the overall shape of the scaffold, which aids in repairing different regions of the bone. The main objectives of this dissertation were to develop bioactive glass (BG) scaffolds using the SLS process and evaluate the scaffolds for their effectiveness in bone repair both in vitro and in vivo. 13-93 glass, a silicate based BG, and 13-93B3 glass, a borate based BG, are designed to accelerate the body's natural ability to heal itself and are used …

Computational Modeling Of Cardiac Biomechanics, Amir Nikou

Theses and Dissertations--Mechanical and Aerospace Engineering

The goal of this dissertation was to develop a realistic and patient-specific computational model of the heart that ultimately would help medical scientists to better diagnose and treat heart diseases. In order to achieve this goal, a three dimensional finite element model of the heart was created using magnetic resonance images of the beating pig heart. This model was loaded by the pressure of blood inside the left ventricle which was measured by synchronous catheterization. A recently developed structurally based constitutive model of the myocardium was incorporated in the finite element solver to model passive left ventricular myocardium. Additionally, an …

Morphology Of Brain Sulci Trabeculae And Its Effect On Brain During Impacts, Sharlin Anwar

Dissertations and Theses

Traumatic brain injury (TBI) is an intracranial injury caused by direct contact or non-contact head impacts to the brain. TBI is a major problem that accounts for high incidents of hospitalizations each year. Thus, it is important to understand and predict the occurrence of TBI in an impact. It has been shown that the subarachnoid space (SAS) trabeculae play an important role in damping the effect of an impact, thus reducing the injuries. However, the influence of sulci parameters and the sulci trabeculae in TBI due to impact is unexplored. Studies have shown that inclusion of sulci in brain models …

Mechanical Impedance Of Ankle As A Function Of Electromyography Signals Of Lower Leg Muscles Using Artificial Neural Network, Chen Jia

Dissertations, Master's Theses and Master's Reports - Open

This paper reports on the feasibility of developing a model to describe the nonlinear relationship between the mechanical impedance of the human ankle within a specified range of frequency and the root mean square (RMS) value of the Electromyography (EMG) signals of the muscles of human ankle using Artificial Neural Network (ANN). A lower extremity rehabilitation robot — Anklebot was used to apply pseudo-random mechanical perturbations to the ankle and measure the angular displacement of the ankle to estimate the data of ankle mechanical impedance. Meanwhile, the surface EMG signals from the selected muscles were monitored and recorded using a …

Multi-Scale Visualization Of Molecular Architecture Using Real-Time Ambient Occlusion In Sculptor, Manuel Wahle, Willy Wriggers

Mechanical & Aerospace Engineering Faculty Publications

The modeling of large biomolecular assemblies relies on an efficient rendering of their hierarchical architecture across a wide range of spatial level of detail. We describe a paradigm shift currently under way in computer graphics towards the use of more realistic global illumination models, and we apply the so-called ambient occlusion approach to our opensource multi-scale modeling program, Sculptor. While there are many other higher quality global illumination approaches going all the way up to full GPU-accelerated ray tracing, they do not provide size-specificity of the features they shade. Ambient occlusion is an aspect of global lighting that offers great …

Generation And Delivery Of Charged Aerosols To Infant Airways, Landon T. Holbrook

Theses and Dissertations

The administration of pharmaceutical aerosols to infants on mechanical ventilation needs to be improved by increasing the efficiency of delivery devices and creating better ways of evaluating potential therapies. Aerosolized medicines such as surfactants have been administered to ventilated infants with mixed results, but studies have shown improvement in respiratory function with a much lower dose than with liquid instillation through an endotracheal tube (ETT). An aerosolized medicine must be transported through the ventilation tubing and deposit in the lungs to have the desired therapeutic response.

This work has taken a systematic approach to (i) develop new devices for the …

Computational Modeling To Assess Surgical Procedures For The Treatment Of Adult Acquired Flatfoot Deformity, Brian A. Smith

Theses and Dissertations

Several surgically corrective procedures are considered to treat Adult Acquired Flatfoot Deformity (AAFD) patients, relieve pain, and restore function. Procedure selection is based on best practices and surgeon preference. Recent research created patient specific models of Adult Acquired Flatfoot Deformity (AAFD) to explore their predictive capabilities and examine effectiveness of the surgical procedure used to treat the deformity. The models’ behavior was governed solely by patient bodyweight, soft tissue constraints, and joint contact without the assumption of idealized joints. The current work expanded those models to determine if an alternate procedure would be more effective for the individual. These procedures …

Freeform Extrusion Fabrication Of Titanium Fiber Reinforced 13-93 Bioactive Glass Scaffolds, Albin Thomas

Masters Theses

"Although implants made with bioactive glass have shown promising results for bone repair, their application in repairing load-bearing long bones is limited due to their poor mechanical properties as compared to human bones. This thesis study is on freeform extrusion fabrication of silicate based 13-93 bioactive glass scaffolds reinforced with titanium fibers. A composite paste was prepared with 13-93 bioactive glass filled with titanium fibers (~16 µm in diameter and aspect ratio of ~250) having 0.1 to 0.4 vol. % of the bioactive glass scaffold. This paste was then filled into a syringe manually, and then extruded through a nozzle …

Induction Of Differentiation Of Dental Pulp-Derived Mesenchymal Stem Cells (Dpsc), Aubrey Young

UNLV Theses, Dissertations, Professional Papers, and Capstones

Mesenchymal stem cells are derived from a variety of human tissues and are being bioengineered and studied for possible uses in the advancement of medicine. Recent efforts are being focused on Dental Pulp Stem Cells (DPSC's) due to the accessibility of this tissue. Many factors influence DPSC quality and quantity, including the specific methods used to isolate, collect, concentrate, and store these isolates once they are removed. Ancillary factors, such as the choice of media, the selection of early versus late passage cells, and cryopreservation techniques may also influence the differentiation potential and proliferative capacity of DPSC isolates.

The objective …

Designing A Biomimetic Testing Platform For Actuators In A Series-Elastic Co-Contraction System, Ryan Tyler Schroeder

UNLV Theses, Dissertations, Professional Papers, and Capstones

Actuators determine the performance of robotic systems at the most intimate of levels. As a result, much work has been done to assess the performance of different actuator systems. However, biomimetics has not previously been utilized as a pretext for tuning a series elastic actuator system with the purpose of designing an empirical testing platform. Thus, an artificial muscle tendon system has been developed in order to assess the performance of two distinct actuator types: (1) direct current electromagnetic motors and (2) ultrasonic rotary piezoelectric motors. Because the design of the system takes advantage of biomimetic operating principles such as …