Biomedical Engineering and Bioengineering Commons^™

Predictive Simulation Of Human Movement And Applications To Assistive Device Design And Control, Vinh Nguyen

Doctoral Dissertations

Predictive simulation based on dynamic optimization using musculoskeletal models is a powerful approach for studying biomechanics of human gait. Predictive simulation can be used for a variety of applications from designing assistive devices to testing theories of motor controls. However, one of the challenges in formulating the predictive dynamic optimization problem is that the cost function, which represents the underlying goal of the walking task (e.g., minimal energy consumption) is generally unknown and is assumed a priori. While different studies used different cost functions, the qualities of the gaits with those cost functions were often not provided. Therefore, this dissertation …

Multidisciplinary Education And Research In Biomathematics For Solving Global Challenges, Padmanabhan Seshaiyer

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Biophysical And Biomechanical Properties Of Neural Progenitor Cells As Indicators Of Developmental Neurotoxicity, Gautam Mahajan, Moo-Yeal Lee, Chandrasekhar R. Kothapalli

Chemical & Biomedical Engineering Faculty Publications

Conventional in vitro toxicity studies have focused on identifying IC50 and the underlying mechanisms, but how toxicants influence biophysical and biomechanical changes in human cells, especially during developmental stages, remain understudied. Here, using an atomic force microscope, we characterized changes in biophysical (cell area, actin organization) and biomechanical (Young's modulus, force of adhesion, tether force, membrane tension, tether radius) aspects of human fetal brain-derived neural progenitor cells (NPCs) induced by four classes of widely used toxic compounds, including rotenone, digoxin, N-arachidonoylethanolamide (AEA), and chlorpyrifos, under exposure up to 36 h. The sub-cellular mechanisms (apoptosis, mitochondria membrane potential, DNA damage, glutathione …

Predicting And Preventing Traumatic Brain Injury: A Novel Computational Approach, Kewei Bian

Electronic Thesis and Dissertation Repository

Traumatic brain injury (TBI) is a severe health problem for society. Meanwhile, predicting and preventing TBI remains challenging in the field. Peak rotational velocity was demonstrated to be correlated to brain strain responses, and hence could potentially serve as a good predictor for brain injury. Brain strain was influenced by impact direction, deceleration and impact loading curve shapes. Wearing helmets is an effective way to protect the brain from TBI, but there lacks a study on evaluating helmet performance based on both energy absorption and brain strain response, which this study addressed. Interestingly, helmet shell absorbed around half of the …

The Effect Of Implant Conformity On Muscle Force Requirements In The Implanted Knee, Grace Mcconnochie

Boise State University Theses and Dissertations

Implant geometry is a significant factor in determining knee stability and patient satisfaction following total knee replacement (TKR). Ineffective muscle recruitment, impaired joint functionality and increased implant wear are consequences of an unstable knee replacement. Current knee laxity evaluation techniques are limited in their ability to account for the muscular response to knee instability. This study utilizes a subject specific lower-body musculoskeletal finite element (FE) model with dynamic muscle loading to evaluate implant laxity during activities of daily living. The effect of varying implant conformity on the muscle forces required to maintain a target kinematic profile during simulated laxity testing …

Development Of A Statistical Shape-Function Model Of The Implanted Knee For Real-Time Prediction Of Joint Mechanics, Kalin Gibbons

Boise State University Theses and Dissertations

Outcomes of total knee arthroplasty (TKA) are dependent on surgical technique, patient variability, and implant design. Non-optimal design or alignment choices may result in undesirable contact mechanics and joint kinematics, including poor joint alignment, instability, and reduced range of motion. Implant design and surgical alignment are modifiable factors with potential to improve patient outcomes, and there is a need for robust implant designs that can accommodate patient variability. Our objective was to develop a statistical shape-function model (SFM) of a posterior stabilized implant knee to instantaneously predict output mechanics in an efficient manner. Finite element methods were combined with Latin …

Investigation Of Fundamental Principles Of Rigid Body Impact Mechanics, Khalid Alluhydan

Mechanical Engineering Research Theses and Dissertations

In impact mechanics, the collision between two or more bodies is a common, yet a very challenging problem. Producing analytical solutions that can predict the post-collision motion of the colliding bodies require consistent modeling of the dynamics of the colliding bodies. This dissertation presents a new method for solving the two and multibody impact problems that can be used to predict the post-collision motion of the colliding bodies. Also, we solve the rigid body collision problem of planar kinematic chains with multiple contacts with external surfaces.

In the first part of this dissertation, we study planar collisions of Balls and …

Transmission Probability Of Embolic Debris Through The Aortic Arch And Daughter Vessels During A Transcatheter Aortic Valve Replacement Procedure, Jessica Lena Wirth

Master's Theses

Cerebral ischemia leading to an ischemic stroke is a possible complication of a transcatheter aortic valve replacement (TAVR) procedure. This is because embolic debris can become dislodged and travel through the aortic arch, where they either continue to the descending aorta and join the systemic circulation or travel into the cerebral vasculature through the three daughter vessels that branch off the top of the aortic arch. These three vessels are the brachiocephalic artery, the left subclavian artery, and the left common carotid artery. These three vessels lead either directly or indirectly to the cerebral vasculature, where the diameter of vessels …

Sand Foot: A Prosthesis For Walking On Sand, Samantha A. Galicinao, John Dewing, Daniel Dugan Dotson, Christopher Urasaki

Biomedical Engineering

This critical design report describes the product development of a prosthesis for use on sand. Quality of Life Plus (QL+), a national non-profit organization aimed to develop prostheses for veterans and people with disabilities, introduced this project and its accompanying challenger, Sgt. Brady, to Cal Poly’s Interdisciplinary Senior Project class in September 2018. After consulting with Sgt. Brady and QL+ and performing extensive research, the Sand Foot team defined customer requirements and engineering specifications to meet these requirements. Comfortability, durability, and sandproof were key customer requirements. Several conceptual models were brainstormed and a final design was selected based on the …

Composite Biomaterial Repair Strategy To Restore Biomechanical Function And Reduce Herniation Risk In An Ex Vivo Large Animal Model Of Intervertebral Disc Herniation With Varying Injury Severity, Warren W. Hom, Melanie Tschopp, Huizi A. Lin, Philip Nasser, Damien M. Laudier, Andrew C. Hecht, Steven B. Nicoll, James C. Iatridis

Publications and Research

Back pain commonly arises from intervertebral disc (IVD) damage including annulus fibrosus (AF) defects and nucleus pulposus (NP) loss. Poor IVD healing motivates developing tissue engineering repair strategies. This study evaluated a composite injectable IVD biomaterial repair strategy using carboxymethylcellulose-methylcellulose (CMC-MC) and genipincrosslinked fibrin (FibGen) that mimic NP and AF properties, respectively. Bovine ex vivo caudal IVDs were evaluated in cyclic compression-tension, torsion, and compression-to-failure tests to determine IVD biomechanical properties, height loss, and herniation risk following experimentally-induced severe herniation injury and discectomy (4 mm biopsy defect with 20% NP removed). FibGen with and without CMC-MC had failure strength similar …

Developing An Optomechanical Approach For Characterizing Mechanical Properties Of Single Adherent Cells, Ali Mehrnezhad

LSU Doctoral Dissertations

Mechanical properties of a cell reflect its biological and pathological conditions including cellular disorders and fundamental cellular processes such as cell division and differentiation. There have been active research efforts to develop high-throughput platforms to mechanically characterize single cells. Yet, many of these research efforts are focused on suspended cells and use a flow-through configuration. Therefore, adherent cells are detached prior to the characterization, which seriously perturbs the cellular conditions. Also, methods for adherent cells are limited in their throughput.

My study is aimed to fill the technical gap in the field of single cell analysis, which is a high-throughput …

Static Accuracy Analysis Of Vicon T40s Motion Capture Cameras Arranged Externally For Motion Capture In Constrained Aquatic Environments, Shreyas L. Raghu, Chang-Kwon Kang, Paul Whitehead, Akifumi Takeyama, Ryan Conners

PRC-Affiliated Research

While the capabilities of land-based motion capture systems in biomechanical applications have been previously reported, the possibility of using motion tracking systems externally to reconstruct markers submerged inside an aquatic environment has been under explored. This study assesses the ability of a motion capture system (Vicon T40s) arranged externally to track a retro-reflective marker inside a glass tank filled with water and without water. The reflective tape used for marker creation in this study was of Safety of Life at Sea (SOLAS) grade as the conventional marker loses its reflective properties when submerged. The overall trueness calculated based on the …

Static Accuracy Analysis Of Vicon T40s Motion Capture Cameras Arranged Externally For Motion Capture In Constrained Aquatic Environments, Shreyas L. Raghu, Chang-Kwon Kang, Paul Whitehead, Akifumi Takeyama, Ryan Conners

PRC-Affiliated Research

While the capabilities of land-based motion capture systems in biomechanical applications have been previously reported, the possibility of using motion tracking systems externally to reconstruct markers submerged inside an aquatic environment has been under explored. This study assesses the ability of a motion capture system (Vicon T40s) arranged externally to track a retro-reflective marker inside a glass tank filled with water and without water. The reflective tape used for marker creation in this study was of Safety of Life at Sea (SOLAS) grade as the conventional marker loses its reflective properties when submerged. The overall trueness calculated based on the …

Static Accuracy Analysis Of Vicon T40s Motion Capture Cameras Arranged Externally For Motion Capture In Constrained Aquatic Environments, Shreyas L. Raghu, Chang-Kwon Kang, Paul Whitehead, Akifumi Takeyama, Ryan Conners

PRC-Affiliated Research

While the capabilities of land-based motion capture systems in biomechanical applications have been previously reported, the possibility of using motion tracking systems externally to reconstruct markers submerged inside an aquatic environment has been under explored. This study assesses the ability of a motion capture system (Vicon T40s) arranged externally to track a retro-reflective marker inside a glass tank filled with water and without water. The reflective tape used for marker creation in this study was of Safety of Life at Sea (SOLAS) grade as the conventional marker loses its reflective properties when submerged. The overall trueness calculated based on the …

Energy Expenditure And Stability During Self-Paced Walking On Different Slopes, Alanna Raffaelli

Electronic Theses and Dissertations

Metabolic power and cost of transport (COT) are common quantifiers for effort when performing tasks including walking and running. Most studies focus on using a range of normal walking speeds over level ground or varied slopes. However, these studies use fixed-speed conditions. Fatigue, stability, metabolic expenditure, heart rate, and many other factors contribute to normal walking speed varying over time. This study aimed to show that allowing a subject to walk with a self-paced speed should correlate to a minimum COT at a given slope. This study also aimed to determine if a preferred slope exists based on minimizing metabolic …

Conceptualization And Fabrication Of A Bioinspired Mobile Robot Actuated By Shape Memory Alloy Springs, Lietsel Richardson

Electronic Theses and Dissertations

This work is an experimental study and fabrication of design concepts to validate the feasibility of smart materials and their applications in bio-inspired robotics. Shape-Memory Alloy (SMA) springs are selected as the smart material actuators of interest to achieve locomotion in the proposed mobile robot. Based on a previous design of the robot, this work focuses on both implementing a new locomotion concept and reducing size and weight of the previous design, both using SMA based actuators. Objectives are met in consideration of the conceptual mechanics of circular robot locomotion. The first prototype is a variation of the original design. …

Fluctuations In Walking Speeds And Spatiotemporal Gait Parameters When Walking On A Self-Paced Treadmill At Level, Incline, And Decline Slopes, Cesar Castano

Electronic Theses and Dissertations

On a daily basis, humans walk over a variety of terrains. Studies have shown that spatiotemporal gait parameters, such as stride length, stride frequency, stride variability, etc., change when humans walk down a decline and up an incline compared to level ground. However, these studies have been limited to using fixed speed treadmills or analyzing a small number of strides when conducted over ground. Thus, there is a need to investigate the fluctuations in spatiotemporal gait parameters of humans walking at their self-selected speed, which requires recording hundreds of strides. Here we hypothesized that subjects will walk with a slower …

Volumetric Muscle Loss: The Role Of Physical Activity And Autologous Repair On Force Recovery And Signaling Pathways, Richard Perry

Graduate Theses and Dissertations

Volumetric muscle loss affects both military and civilian persons. The hallmark of this injury is incomplete muscle regeneration, excessive fibrosis, and chronic inflammatory signaling resulting in permanent functional loss. Since permanent functional loss drastically reduces quality of life, many studies have been conducted to improve force recovery. Current scientific literature considers a repair strategy of either devitalized scaffolds infused with growth factors or viable tissue plus activating factors to be the more promising interventions for optimal force recovery. PURPOSE The purpose of this study is to incorporate autologous repair and physical activity and observe the effects of muscle force recovery …

Classifying And Predicting Walking Speed From Electroencephalography Data, Allen Rahrooh

Electronic Theses and Dissertations

Electroencephalography (EEG) non-invasively records electrocortical activity and can be used to understand how the brain functions to control movements and walking. Studies have shown that electrocortical dynamics are coupled with the gait cycle and change when walking at different speeds. Thus, EEG signals likely contain information regarding walking speed that could potentially be used to predict walking speed using just EEG signals recorded during walking. The purpose of this study was to determine whether walking speed could be predicted from EEG recorded as subjects walked on a treadmill with a range of speeds (0.5 m/s, 0.75 m/s, 1.0 m/s, 1.25 …

Role Of Local Renin-Angiotensin System In Potentiating Early Calcific Aortic Valve Disease, Jessica Perez

Graduate Theses and Dissertations

Angiotensin-II (Ang-II), a peptide hormone, is a potent vasoconstrictor and cell mitogen. It has been implicated in the development of hypertension as well as atherosclerosis. Recent work has shown that sclerotic aortic valves possess expression of angiotensin type I receptor (AT-1R) and angiotensin converting enzyme (ACE), suggesting altered angiotensin signaling during disease. The role of altered angiotensin signaling on aortic valve mechanics, however, is not clearly understood. We seek to understand the direct effects of the renin angiotensin signaling (RAS) system on the biological and biomechanical properties of aortic valve tissue and develop a finite constitutive model that mimics the …

Vector Flow Imaging In Pediatric Cardiology - Extracting And Validating Data, Mason Belue

Biomedical Engineering Undergraduate Honors Theses

In the field of bedside cardiac diagnostic imaging, Doppler Ultrasound (DU) is the gold standard for diagnosing heart conditions. The largest benefit of DU is its ability to noninvasively image cardiac flow and allow the estimation of blood velocity and quantification of anatomical disease. However, to get correct velocity estimation, the position of the transducer in relation to the flow field needs to be known. This is the problem of angle/direction dependency and limits DUs accuracy when imaging in areas where perfect alignment or exact position of the transducer in relation to flow field is not possible or known, such …

Role Of Angiotensin I And Ii On The Tissue Mechanics Of The Aortic Heart Valve Via Receptor Binding And Converting Enzymes, Josh Fahy

Biomedical Engineering Undergraduate Honors Theses

The renin-angiotensin system (RAS) plays a crucial role in the regulation of renal, cardiac, and vascular physiology. This system regulates in vivo blood pressure and fluid balance. As renal blood flow decreases, the kidneys convert prorenin into renin and secrete it into the circulatory system. Renin then converts angiotensinogen into angiotensin I (ang-I). The ang-I is then converted into angiotensin II (ang-II) by the angiotensin-converting enzyme (ACE). Ang-II, a vasoconstrictor, increases blood pressure by causing the blood vessels to narrow. Recent evidence suggests that RAS may be involved in the progression of valve disease, most notably, aortic stenosis.

The first …

Design Of Microporous Membranes For The Development Of Brain-On-Chip Devices, Andre Figueroa Milla

Biomedical Engineering Undergraduate Honors Theses

Traumatic brain injuries (TBIs) are a major global health concern that have an economic impact of $60 billion in the United States in related costs annually. Developing drugs for TBI treatment is an approach that currently faces limitations involving the permeability of the blood-brain barrier (BBB). The BBB naturally limits molecules from reaching the brain as a protective mechanism against disease, acting as a barrier during drug delivery. Understanding the BBB mechanically and chemically following a TBI could potentially assist future studies to alleviate the symptoms and long-term effects of TBI by pharmaceuticals. The Mechanobiology and Soft Materials Laboratory (MSML) …

3d Printing A Microfluidic Chip Capable Of Droplet Emulsion Using Ninjaflex Filament, Robert Andrews

Mechanical Engineering Undergraduate Honors Theses

This paper details an investigation into methods and designs of 3D printing a microfluidic system capable of droplet emulsion using NinjaFlex filament. The specific field in which this paper’s experiment is rooted is dubbed “BioMEMS,” short for bio microelectromechanical systems. One prominent research area in BioMEMS is developing a “lab on a chip.” Essentially, the goal is to miniaturize common lab processes to the micro scale, rendering it possible to include these processes in a small chip. Reducing necessary sample sizes, shortening the reaction times of lab processes, and increasing mobility of lab processes can all be realized through microfluidic …

Improving Material Mapping In Glenohumeral Finite Element Models: A Multi-Level Evaluation, Nikolas K. Knowles

Electronic Thesis and Dissertation Repository

An improved understanding of glenohumeral bone mechanics can be elucidated using computational models derived from computed tomography data. Although computational tools, such as finite element analysis, provide a powerful quantitative technique to evaluate and answer a variety of biomechanical and clinical questions, glenohumeral finite element models (FEMs) have not kept pace with improvements in modeling techniques or model validation methods seen in other anatomic locations. The present work describes the use of multi-level computational modeling to compare, develop and validate FEMs of the glenohumeral joint.

Common density-modulus relationships within the literature were evaluated using a multi-level comparative testing methodology to …

Kinematics During Knee Extension, Lunge, And Chair Rise, Center For Orthopaedic Biomechanics, Kevin Shelburne, Phd, Michael D. Harris, Phd, Vasiliki Kefala, Donald R. Hume, Bradley S. Davidson, A. J. Cyr, R. H. Kim, A. A. Ali, E. M. Mannen

Living Kinematics of the Knee

No abstract provided.

The Effect Of Defects And Surface Modification On Biomolecular Assembly And Transport, Haneen Martinez

Nanoscience and Microsystems ETDs

Nanoscale transport using the kinesin-microtubule (MT) biomolecular system has been successfully used in a wide range of nanotechnological applications including self-assembly, nanofluidic transport, and biosensing. Most of these applications use the ‘gliding motility geometry’, in which surface-adhered kinesin motors attach and propel MT filaments across the surface, a process driven by ATP hydrolysis. It has been demonstrated that active assembly facilitated by these biomolecular motors results in complex, non-equilibrium nanostructures currently unattainable through conventional self-assembly methods. In particular, MTs functionalized with biotin assemble into rings and spools upon introduction of streptavidin and/or streptavidin-coated nanoparticles. Upon closer examination of these structures …

A Numerical Analysis Of The Effects Of Wing Kinematics On Flapping Wing Aeroacoustics, Kabilan Nedunchezian, Chang-Kwon Kang, Hikaru Aono

PRC-Affiliated Research

Despite the recent interest in flapping wing aerodynamics, the aerodynamic sound generation mechanism of a flapping wing is inadequately understood. In this paper, the interplay between the wing motion, resulting unsteady aerodynamics, and aeroacoustics of a flapping wing flyer is investigated. The wing motion is varied in terms of the flapping amplitude, pitching amplitude, and the phase difference between flap and pitch. The unsteady flow around the flapping wing is numerically calculated using a well-validated Navier-Stokes equation solver. Acoustic pressures are computed using the Ffowcs-Williams-Hawkings equation in a three-dimensional space at varying distances from the wing. Two main sound generation …

A Numerical Analysis Of The Effects Of Wing Kinematics On Flapping Wing Aeroacoustics, Kabilan Nedunchezian, Chang-Kwon Kang, Hikaru Aono

PRC-Affiliated Research

Despite the recent interest in flapping wing aerodynamics, the aerodynamic sound generation mechanism of a flapping wing is inadequately understood. In this paper, the interplay between the wing motion, resulting unsteady aerodynamics, and aeroacoustics of a flapping wing flyer is investigated. The wing motion is varied in terms of the flapping amplitude, pitching amplitude, and the phase difference between flap and pitch. The unsteady flow around the flapping wing is numerically calculated using a well-validated Navier-Stokes equation solver. Acoustic pressures are computed using the Ffowcs-Williams-Hawkings equation in a three-dimensional space at varying distances from the wing. Two main sound generation …

A Numerical Analysis Of The Effects Of Wing Kinematics On Flapping Wing Aeroacoustics, Kabilan Nedunchezian, Chang-Kwon Kang, Hikaru Aono

PRC-Affiliated Research

Despite the recent interest in flapping wing aerodynamics, the aerodynamic sound generation mechanism of a flapping wing is inadequately understood. In this paper, the interplay between the wing motion, resulting unsteady aerodynamics, and aeroacoustics of a flapping wing flyer is investigated. The wing motion is varied in terms of the flapping amplitude, pitching amplitude, and the phase difference between flap and pitch. The unsteady flow around the flapping wing is numerically calculated using a well-validated Navier-Stokes equation solver. Acoustic pressures are computed using the Ffowcs-Williams-Hawkings equation in a three-dimensional space at varying distances from the wing. Two main sound generation …