Biomechanics and Biotransport Commons^™

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 …

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 …

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 …

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) …

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 …

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 …

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 …

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 …

Gait Alterations After Anterior Cruciate Ligament Injury And Implications For Return-To-Play Testing, Lindsey Remski

UNO Student Research and Creative Activity Fair

Introduction: Reoccurring injury to the anterior cruciate ligament (ACL) is a major problem for individuals who undergo ACL reconstructive surgery despite them meeting current requirements for return-to-play. Previous studies have found alterations in gait kinetics and kinematics of ACL deficient and ACL reconstruction patients. It is unknown if gait parameters, such as peak joint angles and moments, provide different information about patient function from what is provided by return-to-play outcomes. Purpose: To assess the relationships between peak joint angles, peak joint moments, and return-to-play outcomes for individuals with ACL injury. Methods: 6 subjects (3 ACL reconstruction, 3 ACL deficient) performed …

Effects Of A Passive Dynamic Lower-Leg Exoskeleton During Walking, Blake Beier

UNO Student Research and Creative Activity Fair

The ankle joint is one of the most important joints during walking. If the muscles surrounding the ankle are weak, there are reductions in the ability to generate appropriate torques and powers at the ankle. This leads to slower self-selected walking speeds, which correlate with poor physical functioning, more disabilities, increased hospitalization visits and costs, and even mortality. Because of this, many orthotic and exoskeletal devices have been created to restore proper ankle function by promoting ankle plantar flexion. Utilizing 3D printing and an extension spring, we created an easily accessible, reproducible, and modifiable exoskeleton that has the potential to …

Intensity And Pattern Of Daily Physical Activity Of Claudicating Patients, Cody Anderson

UNO Student Research and Creative Activity Fair

file:///C:/Users/codya/Desktop/Cody%20et%20al_2019_Human%20Movement%20Variability%20Conference.pdf

Visual Contributions To Balance Control During Gait, Kyle Brozek

UNO Student Research and Creative Activity Fair

We propose to isolate the contributions of continuous OF to the orthogonal relationship between balance and gait control during treadmill walking using a series of conditions. Manipulating the direction of OF using a CAREN (Motek Medical, Amsterdam, Netherlands) virtual reality treadmill environment will isolate these visual contributions in human subjects as they walk. We plan to tease out the effect of OF direction on the relationship between gait and balance control by having healthy young adults perform a series of treadmill walking trials while immersed in a VR environment. This will be done by manipulating the direction of walking and …

Determining The Relationship Between Walking Activity And Inter-Day Patterns In Stroke Survivors, Sydney Andreasen

UNO Student Research and Creative Activity Fair

Populations that have suffered from stroke are generally less active than people of otherwise similar demographics and are more susceptible to further health problems, such as another stroke. This study seeks to assess the validity of a treatment that encourages stroke survivors to walk more steps each day, in order to improve their active abilities and become less idle by establishing motivation for activity and therefore, also establishing patterns in the distribution of that activity throughout a stroke survivor’s day. 172 subjects (6 months post-stroke) have participated in a step activity monitoring program to record steps taken using wearable pedometers. …

Gait Alterations In Peripheral Arterial Disease Are Not Worsened By The Presence Of Diabetes, Hafizur Rahman

UNO Student Research and Creative Activity Fair

Peripheral arterial disease (PAD) is a vascular disease where atherosclerotic blockages restrict blood flow to muscles in the lower extremities. Diabetes is a common co-morbid condition in PAD and has been shown to increase the risk of lower extremity amputation compared to PAD without diabetes. Although there is a clear pathological relationship between diabetes and PAD, the gait mechanics involved remain indistinct. Therefore, the purpose of this study was to determine whether the presence of diabetes in addition to PAD results in greater functional impairment during ambulation. Twenty-three subjects with PAD and twelve controls consented to participate in the research. …

Collision Work Performed By Patients With Peripheral Artery Disease, Alex Dzewaltowski, Sara A. Myers, Jason M. Johanning, Iraklis I. Pipinos

UNO Student Research and Creative Activity Fair

The goal of this study was to assess the differences in collision work performed by healthy, aged-matched controls compared to patients with peripheral artery disease (PAD) to provide foundations for an eventual exoskeleton design. Collision work is energy dissipated into the surrounding environment from impact, in this study’s case, upon heel strike. When designing an exoskeleton for patients with PAD, harvesting energy lost to collision work could be a valuable mechanism to improve walking performance. Devices designed to utilize the normally dissipated energy for assisting propulsion to improve walking performance are under-explored [1, 2]. The purpose of this study was …

Bimanual Coordination Assessment Using Prosthetic Simulators, Chris Copeland

UNO Student Research and Creative Activity Fair

There were a total of 1.6 million people living with loss of a limb in 2005. This number is projected to double to 3.6 million by 2050 [1]. While prosthetics aim to enhance the function of these individuals, it is estimated that 45% of pediatric prosthetic users reject their prosthesis [2]. The literature which describes the motor control mechanisms of prosthetic use is sparse and often low-powered due to inadequate number of subjects. However, prosthetic simulators may be a solution to chronically low-powered prosthetic studies by serving as functional homologues. The purpose of this investigation was to determine the efficacy …

A Comparative Study For Feature Selection Algorithms To Analyze Gait Patterns For Health Purposes, Donovan Orn

UNO Student Research and Creative Activity Fair

A Comparative Study for Feature Selection Algorithms to Analyze Gait Patterns for Healthcare Purposes

Donovan Orn

Abstract

With the explosive use of wearable devices, there is an urgent need to find ways to utilize the data collected by such devices. In many cases, wearable devices contain accelerometers that collected different types of data. It is not always clear which data points can be used to extract information that can be used to provide useful knowledge about the health of the individuals. In this study, we proposed to research, implement, and comparing various feature selection techniques used for analyzing on gait …

Simulation Of Joint Contact Forces In Total Knee Arthroplasty Patients Using Opensim, Benjamin Frazier

UNO Student Research and Creative Activity Fair

The occurrence of Total Knee Arthroplasty (TKA) is projected to increase markedly in the coming decade, and a better method of rehabilitating TKA patients is becoming necessary. Rehabilitation of these patients is of utmost importance such that patients are capable of using the limb effectively. Focus towards improving the rehabilitation of patients that have undergone TKA operations requires a metric for comparison of performance between control groups and experimental groups. Joint contact forces (JCF) calculated via simulation in OpenSim using Motion Capture and Force Plate data provide effective means comparing these groups. Subjects are outfitted with a marker set and …

The Energy Paradox Of The Ankle-Foot Complex During Human Walking, Nikolaos Papachatzis, Kota Takahashi

UNO Student Research and Creative Activity Fair

Flexor hallucis longus (FHL) is a multiarticular muscle that possesses the potential to alter foot’s functional and mechanical behavior, since it performs multiple significant functions during walking (e.g supports the medial longitudinal arch of the foot).The purpose of this study was to determine if the functional changes of the FHL are associated with the foot’s adaptations to the mechanical demands of walking. Backward walking is an experimental method capable of altering how the forces propagate underneath the foot and disrupting the mechanical function of the FHL muscle. We hypothesized that: (1) the muscle activity of the FHL will increase during …

Fluid Delivery System For A Cell Culture On A Microfluidic Chip, Austin J. Roeder, Colleen A. Richards, Emily A. Matteson

Biomedical Engineering

This project report provides a description of the progress made in the development of a fluid delivery system for a microfluidic cell culture on a chip. The system is intended to be used in a humidified incubator in a university laboratory and the fluid delivery system is required to exist and operate within that incubator for extended periods of time. Therefore, the system will be gravity-driven and contain no electronic components. The key specification of the system is to provide fluid flow at a constant velocity.

After manufacturing and testing the device, all specifications were met except for the fluid …

Hard, Soft And Off-The-Shelf Foot Orthoses And Their Effect On The Angle Of The Medial Longitudinal Arch: A Biplane Fluoroscopy Study, Megan E.R. Balsdon, Colin E. Dombroski, Kristen Bushey, Thomas Jenkyn

Mechanical and Materials Engineering Publications

Background: Foot orthoses have proven to be effective for conservative management of various pathologies. Pathologies of the lower limb can be caused by abnormal biomechanics such as abnormal foot structure and alignment, leading to inadequate support. Objectives: To compare biomechanical effects of different foot orthoses on the medial longitudinal arch (MLA) during dynamic gait using skeletal kinematics. Study Design: Prospective, cross-sectional study design. Methods: The MLA angle was measured for 12 participants among three groups: pes planus, pes cavus and normal arch. Five conditions were compared: three orthotic devices (hard custom foot orthosis (CFO), soft CFO, and off-the-shelf Barefoot Science©), …

Thenar Muscle And Transverse Carpal Ligament Relationship, Jeremy Granieri Loss

ETD Archive

The transverse carpal ligament (TCL) acts as a partial origin for the thenar muscles (abductor pollicis brevis (APB), flexor pollicis brevis (FPB), opponens pollicis (OPP)). The attachment between the thenar muscles and TCL implies a relationship between the tissues. The thenar muscles rely on their origins for thumb motion and force production. However, individual thenar origin information is lacking. Further information regarding the anatomical relationship between the individual thenar muscles and TCL may provide insight into thenar muscle function. In addition, the TCL responds to thenar muscle contraction as shown by volar migration of the TCL during various thumb movements. …

A Computational Assessment Of Lisfranc Injuries And Their Surgical Repairs, Michael Perez

Theses and Dissertations

While Lisfranc injuries in the mid foot are less common than other ankle and mid foot injuries, they pose challenges in both properly identifying them and treating them. When Lisfranc injuries are ligamentous and do not include obvious fractures, they are very challenging for clinicians to identify unless weight bearing radiographs are used. The result is that 20%-40% of Lisfranc injuries are missed in the initial evaluation. Even when injuries are correctly identified the outcomes of surgical procedures remain poor. Existing literature has compared the different surgical procedures but has not had a standard approach or procedures across studies. This …

Connecting The Pieces: How Low Back Pain Alters Lower Extremity Biomechanics And Shock Attenuation In Active Individuals, Alexa Johnson

Theses and Dissertations--Rehabilitation Sciences

Low back pain in collegiate athletes has been reported at a rate of 37% from a wide array of sports including soccer, volleyball, football, swimming, and baseball. Whereas, in a military population the prevalence of low back pain is 70% higher than the general population. Compensatory movement strategies are often used as an attempt to reduce pain. Though compensatory movement strategies may effectively reduce pain, they are often associated with altered lower extremity loading patterns. Those who suffer from chronic low back pain tend to walk and run slower and with less trunk and pelvis coordination and variability. Individuals with …

Biomechanical Effects Of A Hip Orthosis On Lumbo-Pelvic Coordination, Matthew Ballard

Theses and Dissertations--Biomedical Engineering

Abnormal lumbar movement has been observed in individuals who have a history of low back pain (LBP). Affected individuals display a reduction in lumbar spine rotation during trunk movement tasks, while pelvic rotation increases to compensate. Reduced lumbar contribution to forward bending is associated with increased compressive forces and increased shearing demand of the task on the lower back. This abnormal lumbo-pelvic coordination (LPC) can persist beyond LBP symptom alleviation and may contribute to further occurrences or more severe cases of LBP. This study serves as a first step in investigating if abnormal LPC can be corrected with a hip …