Biomedical Engineering and Bioengineering Commons^™

The Effect Of A Constitutive Formulation On Limb Flexion-Induced Stresses In The Human Femoropopliteal Artery: A Patient-Specific Study, Ali Ahmadi, Anastasia Desyatova

UNO Student Research and Creative Activity Fair

The Effect of a Constitutive Formulation on Limb Flexion-Induced Stresses in the Human Femoropopliteal Artery: a Patient-Specific Study

Peripheral arterial disease (PAD) involves the development of atherosclerotic lesions that restrict the flow of blood to tissues downstream. The femoropopliteal artery (FPA) experiences complex mechanical deformations during daily activities, potentially contributing to the prevalence of PAD and unfavorable treatment outcomes. These deformations generate significant intramural stresses and strains, resulting in arterial injury, disease progression, and restenosis following treatment. Computational modeling offers a way to improve the repair of the FPA; however, the accuracy of these simulations relies on the selection of …

Histological Evidence For The Therapeutic Effect Of Chitosan Nanofibrous Dressing On Acute Skin Wounds In A Rat Model, Mahboubeh Ghanbari, Sayed Ahmadreza Razian, Sara Cartwright, Yury Salkovskiy, Jason Mactaggart, Mark A. Carlson

UNO Student Research and Creative Activity Fair

Introduction: Large-area skin traumas, such as thermal burns, are among the most severe health issues that decrease patients’ quality of life and burden healthcare systems. The CDC estimates that there are 1.1 million burns requiring medical attention each year, with more than 20,000 cases involving at least 25% of the body surface, resulting in 4,500 deaths. In addition, about 10,000 people die from burn-related infections. A promising solution to alleviate this problem is using wound dressings based on biopolymers with inherent wound healing properties and biodegradability. One of these biopolymers is chitosan, which is derived from arthropod shells and exhibits …

The Effects Of Demographics And Risk Factors On The Morphological Characteristics Of Human Femoropopliteal Arteries, Sayed Ahmadreza Razian, Majid Jadidi, Alexey Kamenskiy

UNO Student Research and Creative Activity Fair

Background: Disease of the lower extremity arteries (Peripheral Arterial Disease, PAD) is associated with high morbidity and mortality. During disease development, the arteries adapt by changing their diameter, wall thickness, and residual deformations, but the effects of demographics and risk factors on this process are not clear.

Methods: Superficial femoral arteries from 736 subjects (505 male, 231 female, 12 to 99 years old, average age 51±17.8 years) and the associated demographic and risk factor variables were used to construct machine learning (ML) regression models that predicted morphological characteristics (diameter, wall thickness, and longitudinal opening angle resulting from the …

Time Evolution Is A Source Of Bias In The Wolf Algorithm For Largest Lyapunov Exponents, Kolby Brink, Tyler Wiles, Nicholas Stergiou, Aaron Likens

UNO Student Research and Creative Activity Fair

Human movement is inherently variable by nature. One of the most common analytical tools for assessing movement variability is the largest Lyapunov exponent (LyE) which quantifies the rate of trajectory divergence or convergence in an n-dimensional state space. One popular method for assessing LyE is the Wolf algorithm. Many studies have investigated how Wolf’s calculation of the LyE changes due to sampling frequency, filtering, data normalization, and stride normalization. However, a surprisingly understudied parameter needed for LyE computation is evolution time. The purpose of this study is to investigate how the LyE changes as a function of evolution time …

Reducing Loading On The Contralateral Limb Using Human-In-The-Loop Optimization, Siena Senatore

UNO Student Research and Creative Activity Fair

In most everyday activities, we head towards a specific goal by updating our choices for a more direct path. However, there are specific clinical tasks where taking the direct path is more challenging. Clinical investigations of optimizing a prosthesis involve the assessment of multiple parameter settings through trial and error rather than goal-directed optimization. We investigate if a human-in-the-loop optimization algorithm can guide manual alterations to a prosthesis-simulating device to reduce the ground reaction force on the contralateral limb. In most participants, the optimal condition reduced the loading rate on the contralateral limb compared to the initial condition tested. These …

Optimization Of The Musculoskeletal Simulation In Estimation Of Metabolic Cost, Arash Mohammadzadeh Gonabadi, Philippe Malcolm

UNO Student Research and Creative Activity Fair

Energy from food is supplied to the human body in the form of chemical energy in the muscles. This metabolic energy expenditure is one of the main determinants of the way we walk, and indirect calorimetry measurements are an essential tool for understanding how increases in metabolic cost restrict the mobility of clinical populations. Respiratory oxygen consumption measurements allow recording of the average metabolic cost of walking. However, the time required for these measurements prevents assessing metabolic rate in patients who cannot walk long enough. Musculoskeletal modeling techniques allow to estimate average muscle energy expenditure during locomotion in conjunction with …

How Can Actuation Timing And Magnitude Of A Bilateral Semi-Rigid Hip Exoskeleton Optimize Metabolic Cost, Arash Mohammadzadeh Gonabadi, Prokopios Antonellis, Sara Myers, Iraklis Pipinos, Philippe Malcolm

UNO Student Research and Creative Activity Fair

Semi-rigid exoskeletons could combine some advantages of rigid and soft approaches. The purpose of this study was to investigate the effects of timing and magnitude of assistance from a semi-rigid hip exoskeleton. For ten participants, we tested ten conditions that were combinations of 5 different end-timings, ranging from 21% to 49%, and 2 different moment magnitudes ranging from 0.06 to 0.12 Nm.kg^-1. The participants walked in two reference conditions: a condition without actuation and a condition without the exoskeleton. A semi-rigid hip exoskeleton could alter metabolic rate. However, to produce a net assistive effect, it is necessary to …

Changes In Ankle Muscle Force And Power During Walking In Patients With Peripheral Artery Disease, Hafizur Rahman, Cody Anderson, Iraklis I. Pipinos, Jason M. Johanning, Jianghu Dong, Sara A. Myers

UNO Student Research and Creative Activity Fair

Background: Patients with peripheral artery disease (PAD) have significantly reduced lower extremity muscle strength compared with healthy individuals as measured during isolated, single plane joint motion by isometric and isokinetic strength dynamometers. The objective of this study was to understand the contribution of the ankle muscles during walking in patients with PAD and compared to healthy older individuals.

Methods: A total of 12 patients diagnosed with Fontaine stage II PAD and 10 healthy older controls were recruited for the study. Each subject walked across a 10-meter pathway with reflective markers placed on specific anatomical locations on lower limbs while the …

Design And Development Of Software With A Graphical User Interface To Display And Convert Multiple Microscopic Histology Images, Sayed Ahmadreza Razian, Majid Jadidi, Alexey Kamenskiy

UNO Student Research and Creative Activity Fair

Histological images are widely used to assess the microscopic anatomy of biological tissues. Recent advancements in image analysis allow the identification of structural features on histological sections that can help advance medical device development, brain and cancer research, drug discovery, vascular mechanobiology, and many other fields. Histological slide scanners create images in SVS and TIFF formats that were designed to archive image blocks and high-resolution textual information. Because these formats were primarily intended for storage, they are often not compatible with conventional image analysis software and require conversion before they can be used in research. We have developed a user-friendly …

Breaks In Longitudinal Elastic Fibers Of Human Femoropopliteal Arteries, Elham Zamani

UNO Student Research and Creative Activity Fair

Breaks in Longitudinal Elastic Fibers of Human Femoropopliteal Arteries

Elham Zamani1, Majid Jadidi1

1 Department of Biomechanics, University of Nebraska Omaha, Omaha, NE

Introduction: Elastin is a major protein in the body with half-life >50 years. It is thought that elastic fibers are formed before the postnatal period. In the femoropopliteal artery (FPA), the main artery in the leg, longitudinal elastic fibers are present in External Elastic Lamina (EEL). Our team has studied more than 1000 cadaveric human FPA and has noticed that there are big breaks in their longitudinal elastic fibers in some subjects. Our goal in this work …

Design And Development Of A Semi-Rigid Hip Exoskeleton To Reduce Metabolic Cost, Arash Mohammadzadeh Gonabadi, Prokopios Antonellis, Sara Myers, Iraklis Pipinos, Philippe Malcolm

UNO Student Research and Creative Activity Fair

Robotic exoskeletons can reduce metabolic cost in healthy individuals and restore mobility in patients with peripheral artery disease (PAD). PAD is a cardiovascular disease produced by atherosclerosis of the leg arteries. The primary symptom of PAD is claudication or pain in the legs during walking, which severely shortens the distance a patient can walk. Knowing that up to 40% of the metabolic cost of walking comes from the hip muscles, different groups have been developing rigid exoskeletons and soft exosuits that assist the hip. Assisting at the hip has the advantage that the exoskeleton mass is positioned close to the …

The Effect Of Walking Speed And Magnitude Of Perturbation On Compensatory Responses, Farahnaz Fallah Tafti, Jenna Yentes

UNO Student Research and Creative Activity Fair

Imposing a perturbation can induce an unstable condition during gait. Measuring the compensatory responses may be an accurate indicator of the ability to control stability. Responses to a perturbation can be quantified through the perturbed walking pattern deviations from an unperturbed condition. The aim of this study was to determine the effect of perturbation magnitude or speed of walking on compensatory responses to lateral perturbations during walking. Twenty healthy young participants recruited to this study and they were perturbed with the medium magnitude of perturbation, while walking on the treadmill at three different speeds (slow, preferred, and fast). They also …

Modeling Spatial Asymmetry In Visuomotor Coordination, Kolby Brink, Aaron Likens, Nikolaos Stergiou

UNO Student Research and Creative Activity Fair

Coordination is foundational to human movement. One prominent model of coordination is the Haken-Kelso-Bunz which predicts change in relative phase between two oscillators during movement. Use of this model has shown that the body has a natural tendency to prefer certain coordination patterns over others. The generalizability of the model has sparked its use throughout the scientific community to observe movement through the lens of dynamical systems theory. We contend that this model can be advanced further through incorporation of visually perceived spatial asymmetries, a component not currently accounted for by the model. That is, we sought to find if …

Implementation And Evaluation Of A Baseball Pitching Program And Its Impact On Injury Prevention And Performance, Tyler Hamer

UNO Student Research and Creative Activity Fair

The purpose of this study sought to examine the efficacy of biomechanical evaluations on collegiate baseball pitchers. Through this, we seek to develop a model for identifying at-risk athletes through a longitudinal assessment of pitching mechanics spanning pre-season to post-season along with in-season tracking of pathomechanics.

Foot Temperature Before And After Walking In Patients With Peripheral Artery Disease, Jose Anguiano-Hernandez

UNO Student Research and Creative Activity Fair

Peripheral Artery Disease (PAD) is a pathology that can decrease blood flow to the lower limbs, resulting in the inability to regulate body temperature [1]. The effects of impaired blood flow caused by PAD on body temperature are unclear. The purpose of this study is to compare foot temperature changes before and after walking in healthy people and in patients with PAD. We hypothesize that 1) feet affected by PAD will experience a greater increase in temperature than healthy feet during walking and 2) feet affected by PAD will experience a slower rate of temperature recovery after walking compared …

Autocorrelation And Probability Distributions In Gait-Metronome Synchronization, Charles Sloan

UNO Student Research and Creative Activity Fair

Recent research has shown that the structure of different pacing signals influences gait dynamics during coordination to those signals. Those studies, however, have not looked at the impact that probability distribution functions play in influencing our gait. This study looks at how both autocorrelation functions and probability distribution has in noisy metronomes to look for sources of synchronization. 10 healthy subjects volunteered to complete this study. The participants were required to wear custom-built glasses with a small screen projected on the lens. The screen showed a visual stimulus that correlated with various signals. The results of the study suggest that …

Effects Of Novel Tool Use: Cortical And Functional Measures In Children Using A Prosthetic Simulator, Chris Copeland

UNO Student Research and Creative Activity Fair

As of 2005, there were a total of 1.6 million people living with the loss of a limb, with this population projected to double to 3.6 million by 2050 [1]. While prostheses 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 neurological control mechanisms of prosthetic use is sparse and often low-powered due to an inadequate number of participants. However, prosthetic simulators may be a solution to chronically low-powered prosthetic-centric studies by serving as functional homologues, though this has yet to be tested. …

Developing And Testing Of An Upper Limb Exoskeleton For Stroke Patients, Drew Dudley, David Salazar

UNO Student Research and Creative Activity Fair

Objective: The main objective of this study was to determine functional and neuromuscular outcomes of stroke patients using their non-preferred hand with and without a 3D printed passive exoskeleton compared to controls using their non-preferred hand with and without the passive exoskeleton. Methods: Adults at least six months post stroke (Stroke, n = 5) and age- and sex- matched healthy controls (Control, n = 5) performed nine trials of a gross motor task while having their brain activity measured. The Fugl-Meyer and “Box and Block” test was used to measure the gross dexterity of the subjects with and without the …

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. …

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

Efficacy Of Assistive Devices Produced With Additive Manufacturing, James Pierce

UNO Student Research and Creative Activity Fair

Despite the frequency of musculoskeletal injuries such as sprains, broken bones and torn ligaments¹, treatment options are often costly, time-consuming and ill-fitted.^2,3 Additive manufacturing (“3D-printing) allows for the production of highly-customized and inexpensive assistive devices⁴, which suggests potential efficacy in the prescription of splints and casts for musculoskeletal injury.³ In the present study, a parametric, customizable splint/cast was created using a computer-aided design (CAD) package (Fusion 360, Autodesk, San Rafael, CA, USA) and produced with low-cost, desktop 3D printing (Ultimaker 2+ Extended, Ultimaker, Geldermalsen, Netherlands). Fitting of the devices was performed on five healthy …

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 …

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 …

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 …

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. …

Estimating Variations In Metabolic Cost Within The Stride Cycle During Level And Uphill Walking, Arash Mohammadzadeh Gonabadi

UNO Student Research and Creative Activity Fair

Indirect calorimetry provides the average cost of a stride cycle and prevents from identifying which part of the gait cycle causes increased metabolic cost in patients, however, recent simulation methods allow estimating the time profile of metabolic cost within the stride cycle. In this study, we compare the estimations of the time profile of the metabolic cost of two simulation methods for level and uphill walking. We used kinematic, kinetic and electromyography data from level and uphill walking (one participant) to estimate the time profiles of metabolic cost using the muscle-level metabolic model of Umberger using electromyography and kinematic data …

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 …

Mobility-Based Models For Advancing Diagnostic/Predictive Healthcare, Elham Rastegari

UNO Student Research and Creative Activity Fair

Functional ability has been always considered as one of the important determining factors of individuals’ health and quality of life. Traditional movement analysis systems require expensive facilities and frequent visits for patients to specialized laboratories. Portability and affordability of wearable sensors along with their improved accuracy and capability of monitoring movement during daily activities make them a potential alternative for analyzing mobility patterns for clinical and health assessment purposes. Wearable-based movement data, when combined with other relevant clinical or laboratory data, could enhance evidence-based healthcare and data-driven Clinical Decision Support Systems (CDSS). Utilizing the data from wearable devices, many researchers …

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 …