Biomechanical Engineering Commons^™

Design And Implementation Of A Vision-Based Deep-Learning Protocol For Kinematic Feature Extraction With Application To Stroke Rehabilitation, Juan Diego Luna Inga

Master's Theses

Stroke is a leading cause of long-term disability, affecting thousands of individuals annually and significantly impairing their mobility, independence, and quality of life. Traditional methods for assessing motor impairments are often costly and invasive, creating substantial barriers to effective rehabilitation. This thesis explores the use of DeepLabCut (DLC), a deep-learning-based pose estimation tool, to extract clinically meaningful kinematic features from video data of stroke survivors with upper-extremity (UE) impairments.

To conduct this investigation, a specialized protocol was developed to tailor DLC for analyzing movements characteristic of UE impairments in stroke survivors. This protocol was validated through comparative analysis using peak …

Liftwalker, Kai A. De La Cruz, Lexie Caterine, Adam Monroe, Jame Whealan

Mechanical Engineering

The LiftWalker’s purpose is to lift users with degenerative diseases from a seated to standing position and support them as they practice the motion of walking as a form of physical therapy. The current LiftWalker is upward of $5,000 so we redesigned the LiftWalker to be more accessible around the world. This meant using affordable and accessible materials and manufacturing processes. To achieve this, we made our design mostly out of bike parts and off-the-shelf components. When it came to the lift system, we found that to maintain a safe and comfortable design it was best to purchase a trailer …

Snap It & Send It, Samantha Gonzales, Brienne Berger, Kelsea Clays, Jessica Schmok

Mechanical Engineering

This report details the final design, manufacturing and assembly, testing procedures and results, as well as future design recommendations of a device aimed at enhancing the mountain biking experience for individuals with limited thumb strength. This project particularly focused on the experience of our sponsor, Cal Poly Mechanical Engineering Professor Andrew Kean. Our team's objective was to create a secure, ergonomic handlebar grip system that does not require thumb strength and is adaptable to various mountain bike models. The final design utilizes a rigid hook that snaps onto mountain bike handlebars with a long, flat piece that slides into a …

Development Of A Deep Learning Algorithm Using Electromyography (Emg) And Acceleration To Monitor Upper Extremity Behavior With Application To Individuals Post-Stroke, Nathan Dodd

Master's Theses

Stroke is a chronic illness which often impairs survivors for extended periods of time,

leaving the individual limited in motor function. The ability to perform daily activities

(ADL) is closely linked to motor recovery following a stroke. The objective of

this work is to employ surface electromyography (sEMG) gathered through a novel,

wearable armband sensor to monitor and quantify ADL performance. The first contribution

of this work seeks to develop a relationship between sEMG and and grip

aperture, a metric tied to the success of post-stroke individuals’ functional independence.

The second contribution of this work aims to develop a deep …

Passive Mechanical Properties Of Cardiac And Arterial Tissue: A Paired Comparison Study In A Calf Model, Ola Alsaadi, Jieyang Zhang, Masod Sadipour, Ali N. Azadani

DU Undergraduate Research Journal Archive

Purpose: The mechanical behavior of heart tissue plays a crucial role in elucidating cardiac physiology and pathophysiology. Accurate measurement of the mechanical properties of cardiac and arterial tissues is indispensable for advancing computer simulations and developing medical devices. This study aimed to assess the passive mechanical properties of cardiac and arterial tissue in a calf model using a paired comparison method.

Methods: A planar biaxial stretching device was used to determine the mechanical characteristics of 84 square specimens obtained from 14 different anatomical regions. Cauchy stress-Green strain curves were constructed for each anatomical area, and a Fung-type constitutive …

Pulse Modulation In Braided Pneumatic Actuators Mimics Contractile Behavior Of Biological Muscles, Mohamad Elzein

Student Research Symposium

Advancements in robotics and bioengineering aim to emulate biological muscle systems through robotic actuators, blending mechanical strength with biological adaptability. A lesser-explored aspect is mimicking the pulse-like control characteristic of biological muscles, which contract in response to action potentials from motoneurons, with muscle contractile force relying heavily on the timing between these potentials. This study explores the effect of pulse lengths and the gaps between pulses on braided pneumatic actuators (BPAs), which mimic the nonlinearity and dynamic response of biological muscles. It hypothesizes that artificial muscles utilizing pulse-based control will exhibit a similar force dependency on the intervals between pulses …

Presence Of Atheromatous Plaques And Theirs Effects On The Blood Flow, Belhocine Mostefa Bm, Amrani Hichem Ah, Fedaoui Kamel Dr, Mazouz Hammoudi Mh

Emirates Journal for Engineering Research

The paper utilizes a finite element method to study both the blood flow and atheromatous plaques. Specifically, the COMSOL finite element package is employed to achieve a fluid model. COMSOL is a powerful finite element tool commonly used in various research and industrial domains to study multiphysics problems. The focus of the investigation is on the geometric aspects of the atheromatous plaques. The study considers different forms and arrangements of stenosis, taking into account the irregularities formed by various shapes of the plaques and the resulting flow patterns. The key findings of the research suggest that the pressure and velocity …

Dna/Carbon Nanotube Hybrid Structure And Their Translocation Through A Nanochannel, Daniel Christoffel Viljoen

Graduate Theses and Dissertations

DNA sequencing is of major importance as it is used in fields such as species differentiation, personalized medicine and food safety. Currently sequencing by synthesis is the most popular commercial method of sequencing DNA while Oxford nanopore’s protein based nanopores are the only portable commercial method. Current nanopore based devices have three main issues: Spacial resolution, translocation rate versus sensor strength and dealing with the persistence length of ssDNA. This thesis contributes to ongoing research that aims to create a nanochannel with integrated sensor based sequencing device. The project has two main objectives. The first objective is to improve the …

Environment And Response Of 3d-Encapsulated Mesenchymal Stem Cells To Mechanical Loading, Augustus Greenwood

McKelvey School of Engineering Graduate Student Theses & Dissertations

This thesis explores the micromechanical environment induced when cyclically compressing hydrogels via finite element modeling and experimentally on the impact of loading on mesenchymal stem cells (MSCs) when encapsulated withing 3D hydrogel matrices. Degenerative joint diseases, characterized by cartilage degradation, present significant challenges due to cartilage's limited self-repair capacity. Innovative approaches, including stem cell-based therapies and engineered biomaterials, have emerged as promising strategies for cartilage repair and regeneration. This work specifically investigates the calibration of a bioreactor, the uniformity of load response across the hydrogel constructs via finite element modeling (FEM), and the stress response of MSCs subjected to various …

Model-Based Comparison Of Biological Organism And Electro-Mechanical System Resiliency Strategies, Nicholas Ratycz

Mechanical Engineering Undergraduate Honors Theses

Bio-inspired design has been used by many engineers to solve difficult problems or to make manufacturing processes more efficient. Biomimetics is the study of implementing the structure or function of biological substances, materials, mechanisms, and processes onto artificial ones that mimic the original. The goal of the BIASD tool is to provide bio-inspiration for engineers by studying the fault-adaptive strategies that biological systems use, rather than just their structure or function. In this thesis, the fault adaptive strategies of both a biological example and that of a real cubesat are compared using three types of model-based system diagrams to show …

The Effect Of Football Facemask Design Variability On Dynamic Impact Performance And Quasi-Static Stiffness, Adam W. Smith

All Theses

This research addresses the role of facemasks in helmet systems, focusing on their dynamic impact performance and material properties. A total of 150 facemasks from 30 types and five helmets were tested both quasi-statically and dynamically. The facemasks were grouped by style and helmet type for comparison. Dynamic testing involved three different locations and two speeds, with data collected for maximum angular velocity and linear acceleration. Quasi-static stiffness, performed at two locations, was compared with collected dynamic results to determine the strength of relationship. A concussion metric, HARM, was calculated from collected data and compared across style groups.

Significant differences …

Characterizing The Molecular And Cellular Changes Of Senescent Cells Induced By Diverse Stressors In 2d And 3d Microenvironments, Apoorva Chauhan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Aging is a risk factor for myriad diseases and is often associated with the accumulation of senescent cells. Cellular senescence, a process of irreversible cell cycle arrest, is associated with various changes in cellular morphology and function. While senescence will occur naturally in a time-dependent manner, it can be prematurely induced by various extrinsic and intrinsic factors. Most senescence studies model cell behavior in two-dimensional (2D) microenvironments; however, these models are not physiologically relevant. In this study, the effects of naturally occurring reactive oxygen species (ROS) hydrogen peroxide (H2O2) and commonly used chemotherapy drugs, doxorubicin and palbociclib, on cellular senescence …

Development Of A Discrete Element Model For Artificial Turf, Justin Rittenhouse

Dissertations

NFL data exhibits a distinct correlation between an elevated lower extremity injury rate and synthetic surfaces. These ubiquitous injuries frequently relate to excessive foot traction (i.e., failure to release causing fracture or soft tissue damage). Consequently, a discrete element model was developed using open-source software to analyze stud traction. First, laboratory data was collected via bench level experiments covering seventeen different testing scenarios. A minimum of twenty-five samples were collected per scenario. Total work, average torque, and maximum torque were used as indicators of stud grip. And the latter two were statistically analyzed for outliers and significant differences. Next, an …

Removable Equipment Climate Canopy, Jessica Perez, Sabine Heid, Zil Panchal, Anali Salazar

Mechanical Engineering

The Climate Canopy Project has developed an improved solution for creating an adjustable shade mechanism tailored specifically for users of pull walkers. Through extensive research, goal setting, and a comprehensive framework our project has examined the challenges faced by individuals who rely on walkers for mobility. Our stakeholder requires a product that is lightweight, removable, and compact. This study dissected the designs of previous products on the market and aimed to build a product that aligns with our sponsor’s desires.

This report presents the main goals for the design and manufacturing process, along with key design features utilized to produce …

Effects Of The Loading Rate On Mechanical Properties Of The Human Superficial Femoral Artery, Ali Zolfaghari Sichani, Majid Jadidi

UNO Student Research and Creative Activity Fair

INTRODUCTION: Blood vessels are known for their viscoelastic mechanical behavior, including a dependency on the loading rate. Previous studies have shown mixed results regarding the effects of the loading rate on the mechanical properties of the arterial wall. In this study, our aim was to evaluate the loading rate dependency in the human Superficial Femoral Artery (SFA), the main artery of the leg....

Finite Element Analysis Of The Bearing Component Of Total Ankle Replacement Implants During The Stance Phase Of Gait, Timothy S. Jain

Master's Theses

Total ankle replacement (TAR) implants are an effective option to restore the range of motion of the ankle joint for arthritic patients. An effective tool for analyzing these implants’ mechanical performance and longevity in-silico is finite element analysis (FEA). ABAQUS FEA was used to statically analyze the von Mises stress and contact pressure on the articulating surface of the bearing component in two newly installed fixed-bearing total ankle replacement implants (the Wright Medical INBONE II and the Exactech Vantage). This bearing component rotates on the talar component to induce primary ankle joint motion of plantarflexion and dorsiflexion. The stress response …

Cardiac Active Tension Modeling Via Genetic Algorithm-Optimized Fractional Order Systems, Afnan Khaled Elhamshari

Theses and Dissertations

Developing a computational model to model cardiac activity has been increasingly important in recent decades. Accurate cell-level active tension modeling for cardiomyocytes is critical to understanding cardiac functionality on a patient-specific basis and developing an effective in-silico cardiac model. However, cell-level models in the literature fail to account for viscoelasticity and inter-patient variations in active tension. This research proposes a genetic algorithm-optimized, fractional order system to model cell-level active tension by extending Land’s state-of-the-art model of cardiac contraction. The model features the (left) Caputo derivative of six state variables that identify the mechanistic origins of viscoelasticity in a myocardial cell …

Commentary: A Patient-Specific Lower Extremity Biomechanical Analysis Of A Knee Orthotic During A Deep Squat Movement, Christine Dailey Walck

Publications

The recent study by Walck et al., titled “A Patient-Specific Lower Extremity Biomechanical Analysis of a Knee Orthotic during a Deep Squat Movement,” provides a novel insight into the biomechanical impacts of knee orthotics, particularly the non-linear spring-loaded (NLSL) knee joint orthosis (KJO)1 . This commentary aims to delve into the implications, interpretations, and evaluations of the findings, contextualizing them within the broader discourse on knee orthotics.

Optimal Additive Fabrication Of Patient-Specific Bone Tissue Scaffolds Through Material Formulation, Computational Flow Simulation, And Material Deposition Monitoring, Ethan O’Malley

Theses, Dissertations and Capstones

The advancement of additive manufacturing technologies has opened new avenues for fabricating biocompatible and structurally functional bone tissue scaffolds, essential in treating osseous fractures, defects, and diseases. This research aims to develop mechanically strong, dimensionally precise, and patient-specific porous bone tissue scaffolds that provide both structural integrity and biological functionality. Through three interconnected studies, several key challenges in the fabrication of these structures using the PME additive manufacturing process are addressed. First, the influence of polysaccharide and hydroxyapatite concentrations on the compressive modulus of PME-printed porous scaffolds is investigated. By creating structures with varying hydroxyapatite and polysaccharide compositions, the study …

Design Of Multi-Objective And Optimal Sliding Mode Controller For Tracking Knee Joint Angle During Squatting And Normal Gait Motion, Gabriel Sitler

Theses, Dissertations and Capstones

This work presents two objectives for the use of robust sliding mode controller (SMC) in optimal and multi-objective settings to regulate the position of the knee joint angle for patients suffering from knee injuries. The controller imitates the role of active orthoses that produce the joint torques required to overcome gravity and loading forces and regain natural human movements. The first objective is to focus only on the knee, for which a mathematical model of the shank, the lower part of the leg, is derived first and then used for the control system design and computer simulations. Four objectives are …