Mechanical Engineering Commons^™

Radiation Therapy And Dosing Material Transport Methodology, Robert O'Brien

UNLV Theses, Dissertations, Professional Papers, and Capstones

A technique is examined here that utilizes high energy beta decays from a short lived radioisotope to treat medical conditions such as shallow cancerous lesions. A major benefit of beta particle interaction in tissue is a fixed penetration depth for the charged particle, with dose limited to the ultimate range of the beta particle. This method improves on some current techniques of radioactive brachytherapy, where "seeds" are placed inside patients through temporary or permanent implantation in order to kill cancerous cells or inhibit growth of tissue. The use of low energy gamma-rays is the most common method of treatment currently …

Design And Evaluation Of Pediatric Gait Rehabilitation Robots, Cale J. Stolle

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Gait therapy methodologies were studied and analyzed for their potential for pediatric patients. Using data from heel, metatarsal, and toe trajectories, a nominal gait trajectory was determined using Fourier transforms for each foot point. These average trajectories were used as a basis of evaluating each gait therapy mechanism. An existing gait therapy device (called ICARE) previously designed by researchers, including engineers at the University of Nebraska-Lincoln, was redesigned to accommodate pediatric patients. Unlike many existing designs, the pediatric ICARE did not over- or under-constrain the patient’s leg, allowing for repeated, comfortable, easily-adjusted gait motions. This design was assessed under clinical …

An Emg-Based Patient Monitoring System Using Zynq Soc Device, Farhad Fallahlalehzari

UNLV Theses, Dissertations, Professional Papers, and Capstones

This thesis describes the design, development, and testing of an EMG-based patient monitoring system using the Zynq device. Zynq is a system on chip device designed by Xilinx which consists of an ARM dual cortex-A9 processor as well as an FPGA integrated into one chip. This work also analyzes the performance of image-processing algorithms on this system and compares that performance to more traditional PC-based systems. Image processing algorithms, such as Sobel edge detection, dilation and erosion, could be used in conjunction with a camera for the patient monitoring purposes. These algorithms often perform sub-optimally on processors because of their …

The Effects Of Cryopreservation On Human Dental Pulp-Derived Mesenchymal Stem Cells, Allison Elaine Tomlin

UNLV Theses, Dissertations, Professional Papers, and Capstones

Many studies have demonstrated clinical applications for the use of dental pulp stem cells (DPSC) for the treatment of various conditions. This has driven medical and scientific interest in the collection, isolation and banking of DPSC tissues for research into these potential therapies. Few studies to date have evaluated the viability of DPSC following long-term cryopreservation. The purpose of this study is to evaluate the effects of cryopreservation on dental pulp-derived stem cells (DPSC) viability over a period of three years. Dental pulp-derived stem cells were isolated and cultured from thirty-one healthy teeth. DPSC isolates were assessed for doubling-time and …

Multi-Classifier Fusion Strategy For Activity And Intent Recognition Of Torso Movements, Abhijit Kadrolkar

Doctoral Dissertations

As assistive, wearable robotic devices are being developed to physically assist their users, it has become crucial to develop safe, reliable methods to coordinate the device with the intentions and motions of the wearer. This dissertation investigates the recognition of user intent during flexion and extension of the human torso in the sagittal plane to be used for control of an assistive exoskeleton for the human torso. A multi-sensor intent recognition approach is developed that combines information from surface electromyogram (sEMG) signals from the user’s muscles and inertial sensors mounted on the user’s body. Intent recognition is implemented by following …

Reduced Order Fluid-Structure Interaction Models For Thin Shells With Non-Zero Gaussian Curvatures To Understand The Response Of Aneurysms To Flow, Gary Han Chang

Doctoral Dissertations

In this thesis, a reduced-order model is constructed to study the physiological flow and wall shear stress conditions for aneurysms. The method of local proper orthogonal decomposition (POD) is used to construct the reduced-order modes using a series of CFD results, which are subsequently improved using a QR-factorization technique to satisfy the various boundary conditions in physiological flow problems. This method can effectively construct a computationally efficient physiological model, which allows us to examine the fluid velocities and wall shear stress distributions over a range of different physiological flow parameters. Aneurysms are the dilation, bulging, or ballooning-out of part of …

A Soft Multiple-Degree Of Freedom Load Cell Based On The Hall Effect, Qiandong Nie

Masters Theses

The goal of this thesis is to develop a soft multiple-degree-of-freedom (multi-DOF) load cell that is robust and light weight for use in robotics applications to sense three axes of force and a single axis of torque. The displacement of the magnet within the elastomer changes the magnetic flux density which is sensed by two 3-axis Hall effect sensors. Experimental measurements of magnetic flux density within the area of interest were used to formulate analytic expressions that relate magnet field strength to the position of the magnet. The displacement and orientation measurement and the material properties of the elastomer are …

Flex-Ro: Design, Implementation, And Control Of Subassemblies For An Agricultural Robotic Platform, Jared Patrick Werner

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Automation technology in agriculture is growing, making agricultural robotics viable. Innovative field usable multi-purpose robotic platforms are needed for the successful progression of agricultural robotics. Furthermore, the field of agricultural robotics would benefit from a robotic platform design allowing for variable height, thus accommodating navigation throughout various crop growth stages. A variable height machine, Flex-Ro was developed to accommodate this feature. Multiple sub-assemblies were designed and implemented for Flex-Ro. An electronic control unit (ECU) enabled engine was used to power Flex-Ro. An embedded application program was developed to control engine speed using proprietary Controller Area Network (CAN) messages in conjunction …

Fluid Dynamic Factors As A Cause And Effect Of Biofilm Formation Of Staphylococcus Aureus Biofilms, Erica Sherman

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Staphylococcus aureus bacteria are able to form biofilms and distinctive tower structures that facilitate their ability to tolerate treatment and to spread within the human body. The formation of towers, which break off, get carried downstream and serve to initiate biofilms in other parts of the body are of particular interest here. It is known that flow conditions play a role in the development, dispersion and propagation of biofilms. The influence of flow on tower formation and what factors lead to tower formation is not at all understood The hypothesis being examined is that tower structures form within a specific …

Development And Implementation Of High Fidelity Human Models For The Investigation Of Blast And Non-Penetrating Projectile Impact, Candice F. Cooper

Mechanical Engineering ETDs

Military operations abroad have highlighted the effects of several types of physical traumas including traumatic brain injury and behind armor blunt trauma. While previous approaches toward understanding and mitigating trauma caused by blast or blunt impact relied upon physical testing of animal subjects, post mortem human subjects, or human tissue surrogates, recent advances in computational capability have spurred a growing area of research in computational investigations into wound injury and its mitigation. The development of high-fidelity human torso and head-neck-torso models are presented here. These models are employed in blast and non-penetrating projectile impact simulations in order to demonstrate the …

Movement And Distribution Of Bacteria Near Surfaces, Daniel A. Quinkert, Adib Ahmadzadegan, Arezoo M. Ardekani

The Summer Undergraduate Research Fellowship (SURF) Symposium

Bacteria are found everywhere in nature, including within human/animal bodies, biomedical devices, industrial equipment, oceans and lakes. They can be found in planktonic state within a bulk liquid phase or attached to surfaces with the potential to form biofilms. In this study we are interested in the movement and distribution of bacteria near surfaces. The concentrations and fluid interactions of bacteria were characterized at various distances from a surface. Psuedomonas putida F1 was observed in a suspension near a surface. Bacteria movements were visualized with an inverted microscope at 40x magnification. P. putida F1 exhibited greater density in close proximity …

Mechanical Reliability Of Implantable Polyimide-Based Magnetic Microactuators For Biofouling Removal, Christian G. Figueroa-Espada, Qi Yang, Hyowon Lee

The Summer Undergraduate Research Fellowship (SURF) Symposium

Hydrocephalus is a neurological disorder that typically requires a long-term implantation of a shunt system to manage its symptoms. These shunt systems are notorious for their extremely high failure rate. More than 40% of all implanted shunt systems fail within the first year of implantation. On average, 85% of all hydrocephalus patients with shunt systems undergo at least two shunt-revision surgeries within 10 years of implantation. A large portion of this high failure rate can be attributed to biofouling-related obstructions and infections. Previously, we developed flexible polyimide-based magnetic microactuators to remove obstructions formed on hydrocephalus shunts. To test the long-term …

Strain Energy Absorption Corresponds To Decreased Incidence Of Ventricular Fibrillation In A Commotio Cordis Model, Kayt E. Frisch, Mark S. Link, John Van Weelden

Faculty Work Comprehensive List

A healthy teenage boy is playing high school baseball, when he is struck in the chest by the ball; minutes later, his heart is experiencing ventricular fibrillation (VF) and the only way to resuscitate him is to use a defibrillator. This phenomenon, is known as Commotio Cordis (CC), and occurs as many as 20 times each year in the United States. CC most frequently occurs in sports with small balls (e.g. baseball or lacrosse) and requires a specific set of circumstances–a projectile with a certain amount of energy that impacts directly over the left ventricle of the heart during a …

Developing Predictive Models For Upper Extremity Post–Stroke Motion Quality Estimation Using Decision Trees And Bagging Forest, Sarvenaz Chaeibakhsh

Masters Theses

Stroke is one of the leading causes of long–term disability. Approximately twothirds of stroke survivors require long-term rehabilitation, which suggests the importance of understanding the post-stroke recovery process during his activities of daily living. This problem is formulated as quantifying and estimating the poststroke movement quality in real world settings. To address this need, we have developed an approach that quantifies physical activities and can evaluate the performance quality. Wearable accelerometer and gyroscope are used to measure the upper extremity motions and to develop a mathematical framework to objectively relates sensors’ data to clinical performance indices. In this article we …

Microfluidic Platform For Impedance Characterization Of Endothelial Cells Under Fluid Shear Stress., Vanessa Velasco

Electronic Theses and Dissertations

Endothelium dysfunction has been associated with many pathophysiological processes leading to cardiovascular diseases. Studying endothelium behavior is vital to understand the onset, prevention, and treatment of such diseases. Electrical impedance spectroscopy has been shown to provide a real-time in vitro evaluation of cell behavior including cell monolayer permeability. However, the majority of published work has been primarily with static cell culture models or macro-scale models that do not properly represent the physiological sizes, structures, and environmental conditions of human blood vessels. Within this dissertation, the design, fabrication, characterization, and application of a microfluidic impedance platform is presented for the in …

Non-Puncturing, No Slip Thv Leaflet Gripper, Brooks Kelly, Eric Nagaoka, Johnny Phane

Mechanical Engineering

Confidential

Low-Cost Prosthetic Transfemoral Socket, Emelie Deans, Joshua Ledgerwood, Leah Moore, Shaina Jung, Kristen Temnyk

Mechanical Engineering

The goal of this senior project was to design and fabricate a low-cost adjustable prosthetic socket for above the knee amputees. This low-cost consideration was incorporated with the original intent to be used in Fiji, however, this changed to the Dominican Republic. It became clear that the need for an adjustable socket was more as a transitional socket. This transitional socket would be used for the first 6 -12 months upon amputation because this when the most amount of volume fluctuation occurs. The project sponsor, LIM Innovations, has already designed the Infinite Socket which contains four main functioning parts: baseplate, …

Prosthetic Socket Cooling System, Benjamin K. Kraw, Kathy Ha, Derek Piastrelli, Cuong Lai

Mechanical Engineering

A team of four senior-level undergraduate students in the Interdisciplinary Senior Project Design course in the Engineering Department of California Polytechnic State University: San Luis Obispo have worked to develop a prosthetic socket cooling system, namely for veteran Taylor Morris and exclusively for a transfemoral prosthetic socket, under the Quality of Life+ Laboratory. This cooling system will utilize the thermoelectric effect known as the Peltier effect to transmit heat generated from the residual limb to the surrounding environment by means of forced convection over small aluminum heat sinks. Two measurement devices have also been developed to, one, measure the heat …

Biomimetic Seal Flipper Test Rig, Gordon D. Belyea, Laura Kawashiri, Dylan Rinker, Kurt Beske

Mechanical Engineering

No abstract provided.

The Effects Of Obesity On Resultant Knee Joint Loads For Gait And Cycling, Juan Gutierrez-Franco

Master's Theses

Osteoarthritis (OA) is a degenerative disease of cartilage and bone tissue and the most common form of arthritis, accounting for US$ 10.5 billion in hospital charges in 2006. Obesity (OB) has been linked to increased risk of developing knee OA due to increased knee joint loads and varus-valgus misalignment. Walking is recommended as a weight-loss activity but it may increase risk of knee OA as OB gait increases knee loads. Cycling has been proposed as an alternative weight-loss measure, however, lack of studies comparing normal weight (NW) and OB subjects in cycling and gait hinder identification of exercises that may …

Numerical Modeling Of Fluid-Porous Structure Interaction In Arteries, Rana Zakerzadeh, Paolo Zunino

Biology and Medicine Through Mathematics Conference

No abstract provided.

Walking Simulator Mechanism, Titus Lungu, Igor Tachynskyy, Omri Tayyara

The Downtown Review

This paper presents the design, simulation, and kinematic evaluation of a mechanism aimed at simulating both the motion and ground reaction forces produced by a human foot while walking. Such a mechanism can be used to test the durability of shoes through life cycle analysis. In attempting to mimic the physical motion of the human foot as closely as possible, the forces experienced by the human foot were also accurately replicated through the incorporation of a non-stationary testing platform. As is shown in the paper, this testing environment allows for simple adjustments to be made in order to simulate different …

Adaptive Kernel Estimation For Enhanced Filtering And Pattern Classification Of Magnetic Resonance Imaging: Novel Techniques For Evaluating The Biomechanics And Pathologic Conditions Of The Lumbar Spine, Nicholas Vincent Battaglia

Doctoral Dissertations

This dissertation investigates the contribution the lumbar spine musculature has on etiological and pathogenic characteristics of low back pain and lumbar spondylosis. This endeavor necessarily required a two-step process: 1) design of an accurate post-processing method for extracting relevant information via magnetic resonance images and 2) determine pathological trends by elucidating high-dimensional datasets through multivariate pattern classification. The lumbar musculature was initially evaluated by post-processing and segmentation of magnetic resonance (MR) images of the lumbar spine, which characteristically suffer from nonlinear corruption of the signal intensity. This so called intensity inhomogeneity degrades the efficacy of traditional intensity-based segmentation algorithms. Proposed …

Atomic Force Microscopy Based Dna Analysis, Drew Creighton

Mechanical Engineering Undergraduate Honors Theses

This report explores dry and wet scanning of a surface and DNA pickup using an AFM, as well as fluorescent staining of DNA. Dry and wet scans of DNA were obtained using a cantilever AFM tip in tapping mode. Dry scans were found to be clearer than wet scans; however, the drying process was found to decrease the thickness of DNA 2–4 times less than its original thickness. Alternately, wet scans were found to be less clear than dry scans and introduced more noise into the images obtained. Additionally, DNA kept its initial thickness during wet scanning. DNA was capable …

Mild Traumatic Brain Injury: Combined In Silico And In Vitro Studies, Yi Hua

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Mild traumatic brain injury (TBI) is a significant public health concern worldwide and has attracted significant attention due to high-impact sport as well as improvised explosive devices used in military conflicts. The earliest sign of mild TBI is associated with cognitive, behavioral and physical/somatic changes, which are commonly invisible to existing medical techniques. Thus it is essential to target mechanisms of mild TBI and its associated damage measures for earlier diagnosis/treatment and enhanced protection strategies.

In this work, the mechanism of blast-induced mild TBI was inspected through integrated in silico and in vitro models. A three-dimensional (3D) human head model …

Portable High Throughput Digital Microfluidics And On-Chip Bacteria Cultures, Yiyan Li

UNLV Theses, Dissertations, Professional Papers, and Capstones

An intelligent, portable, and high throughput digital microfluidic (DMF) system is developed. Chapter 1 introduces microfluidics and DMF systems. In Chapter 2, a low-cost and high resolution capacitive-to-digital converter integrated circuit is used for droplet position detection. A field-programmable gate array FPGA is used as the integrated logic hub of the system for highly reliable and efficient control of the circuit. In this chapter a fast-fabricating PCB (printed circuit board) substrate microfluidic system is proposed. Smaller actuation threshold voltages than those previously reported are obtained. Droplets (3 µL) are actuated using 200 V, 500 Hz DC pulses. Droplet positions can …

Spinal Implant Design And Subsidence, Schuyler E. Price, Lorrin Schoeneweis, Hannah Steele, Matthew Shomper, Timothy L. Norman

The Research and Scholarship Symposium (2013-2019)

A spinal implant may be used in people who have diseased or injured intervertebral discs pushing against their spinal cord and nerves, causing them loss of sensation due to nerve impingement. Patients who have not found relief through non-surgical means may require a discectomy, which removes the disc and relieves the pressure. There are several ways to then fill the resulting gap which include fusion devices, artificial disc replacement (ADR) devices, or bone grafts. Our study focused on the first two mechanical options.

Subsidence, or the vertical movement of the device into the adjacent vertebral bodies, is an often reported …

Design And Testing Of Robotic Capsule Biosensors In The Small Intestine, Zachary Bram

Robotics and Mechanical Systems Design

Biosensors are a tool that is growing in usage and is sought out by doctors and patients alike for being a non-invasive method to monitor health. The data that can be collected from these sensors can be analyzed by doctors that are away from patients, or even by patients that do not have the ability to see a doctor. The purpose of this work is to design and test a biosensor capsule that can attach itself to the inner wall of the small intestine for a short period of time before exiting the body. This research project was a continuation …

A Retrospective Study Of Amusement Ride Restraint And Containment Systems: Identifying Design Challenges For Statistically Rare Anthropometric Cases, Paula M. Stenzler

Engineering Management & Systems Engineering Theses & Dissertations

The intent of this project was to conduct a retrospective study of amusement ride restraint and containment systems’ failures to identify the challenges associated with existing design criteria to safely accommodate statistically rare groups that fall outside amusement industry standards. Innovations in ride technology provide an opportunity for injuries to occur if restraint and containment systems cannot properly accommodate unique patron anthropometry. It is paramount to understand how anthropometric features contribute to the patron’s ability to defeat ride restraint and containment systems. A systemic perspective was used based on industry accident data to frame the problem associated with restraint and …

Optimizing The Rehabilitation Of Elbow Lateral Collateral Ligament Injuries, Ranita Harpreet Kaur Manocha

Electronic Thesis and Dissertation Repository

Elbow lateral collateral ligament (LCL) injuries frequently arise following trauma, and can result in disabling instability. Typically such injuries are managed with immobilization followed by a graduated exercise regime; however there is minimal biomechanical evidence to support current treatment protocols. This investigation examines the in vitro effectiveness of several rehabilitation techniques using a custom elbow motion simulator. It was found that active range of motion is safest in the overhead position (n = 7). Early motion in this position may reduce the incidence of elbow stiffness without compromising ligament healing following LCL injury. Forearm pronation and active motion stabilize …