Biomechanical Engineering Commons^™

Design Of Parallel Robot For Dental Articulation And Its Optimization, Abulimiti Delimulati

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

A dental articulator is a mechanical device used to simulate the relative position and motion between the upper and lower jaw when constructing and testing dental prostheses. Typically, it can be adjusted to approximate patient-specific jaw kinematics in order to analogue the static relationship and specific motions of a patient’s mandible to maxilla. However, the use of dental articulators is essentially a trial-and-error method in order to fine-tune fit and function of a dental prosthesis. Some of the most advanced current dental articulators can reproduce the position and the motion passively; furthermore, dentists need special training for measuring patients’ maxillofacial …

Experimental, Analytical, And Numerical Evaluation Of The Mechanical Properties Of The Brain Tissue, Aref Samadidooki

LSU Doctoral Dissertations

A true understanding of the mechanisms behind most of the brain diseases is still out of reach. For several years, the interest of scientists has been focused on the genetic and biological causes, however, recent studies unraveled the importance of the biomechanics of the brain growth, folding, impact resistance, and deformation on its pathological conditions. While, a wide range of different methods have been used for characterization of the mechanical properties of the brain at the tissue level, the obtained results from different studies are extremely scattered and sometimes in contrast to one another. Since the brain tissue is extremely …

Fixing Vertebral Compression Fractures With Medtronic, Kelly Fitzgerald, Trevor Bingham, Alex Denbaugh, Jordan Tang, Jon Stearns

Industrial and Manufacturing Engineering

No abstract provided.

Analysis Of The Low-Cycle Fatigue Behavior Of Silicone Rubber For Biomedical Balloons, Chase Cooper

Materials Engineering

The development of a medical drug delivery device that allows for the deployment drugs into the adventitial tissue of blood vessels requires the inflation of a silicone elastomer. The inflated silicone must be able to consistently endure multiple loading cycles without failing so that the device can operate reliably. There are multiple methods of processing the silicone for the device and the goal of this study is to examine the effect of the various processing methods on the characteristics of the silicone. The Dynamic Mechanical Analysis Machine (DMA) is used to model the conditions of the device’s application by performing …

Team Joseph's Bike Trailer, Keely Thompson, Curtis Wathne, Ryan Meinhardt

Mechanical Engineering

This final design report shows the results of this senior project’s design process of creating a custom bike trailer for Team Joseph. As done in the Scope of Work, Preliminary Design report, and Critical Design report, current products, relevant technologies, and American Society for Testing and Materials (ASTM) standards are fully researched and benchmarked to aid in the design selection process. Customer requirements are looked at and developed into engineering specifications. A detailed design was created for CDR to show to Team Joseph, and manufacturing and testing plans were laid out. This final design report adds the final design revisions …

Curb Navigation, Cole A. Tudor, Kaitlyn R. Adams, Robbie Huerta

Mechanical Engineering

The Curb Navigation senior project, proposed by the QL+ organization, was presented to find a solution to an issue a former veteran, Velette, is having. Velette has a difficult time maneuvering curbs when out doing day-to-day errands and activities. The goal of this project is to develop a solution that will give Velette the ability to traverse curbs without the assistance of others or the need to do a wheelie that can lead to an injury. The team has found that adapting and optimizing an anti-tipper design may be the best way to solve the proposed challenge. The team decided …

Human Knee Fea Model For Transtibial Amputee Tibial Cartilage Pressure In Gait And Cycling, Gregory Lane

Master's Theses

Osteoarthritis (OA) is a debilitating disease affecting roughly 31 million Americans. The incidence of OA is significantly higher for persons who have suffered a transtibial amputation. Abnormal cartilage stress can cause higher OA risk, however it is unknown if there is a connection between exercise type and cartilage stress. To help answer this, a tibiofemoral FEA model was created. Utilizing linear elastic isotropic materials and non-linear springs, the model was validated to experimental cadaveric data. In a previous study, 6 control and 6 amputee subjects underwent gait and cycling experiments. The resultant knee loads were analyzed to find the maximum …

Soft-Microrobotics: The Manipulation Of Alginate Artificial Cells, Samuel Sheckman

Mechanical Engineering Research Theses and Dissertations

In this work, the approach to the manipulation of alginate artificial cell soft-microrobots, both individually and in swarms is shown. Fabrication of these artificial cells were completed through centrifugation, producing large volumes of artificial cells, encapsulated with superparamagnetic iron oxide nanoparticles; these artificial cells can be then externally stimulated by an applied magnetic field. The construction of a Permeant Magnet Stage (PMS) was produced to manipulate the artificial cells individually and in swarms. The stage functionalizes the permanent magnet in the 2D xy-plane. Once the PMS was completed, Parallel self-assembly (Object Particle Computation) using swarms of artificial cells in complex …

Blunt And Ballistic Impacts On Human Head Models: An Analytical And Numerical Study, Yongqiang Li

Mechanical Engineering Research Theses and Dissertations

Head injuries, as a leading cause of death, have become a major health care issue for civilians and soldiers. There has been an urgent need to understand mechanisms of such injuries. The objective of this dissertation research is to study some head injuries and related mechanisms using analytical and computational models.

In Chapter 2, a new analytical (non-linear) model for the impact of a solid sphere on a fluid-filled spherical shell is developed by including the stress wave propagation effect in addition to the Hertzian contact deformations and the shell membrane and bending actions. A simplified (linearized) model incorporating the …

Modeling Of Swimming Cells From Nano-Scale To Micro-Scale, Yicheng Zhao

McKelvey School of Engineering Graduate Student Theses & Dissertations

Certain human genetic diseases -- primary ciliary dyskinesia, infertility, and hydrocephalus -- are characterized by changes in beat frequency and waveform of cilia and flagella. Chlamydomonas reinhardtii, which is a single-cell green alga about ten micrometers in diameter that swims with two flagella, serves as an excellent biological model because its flagella share the same structure and genetic background as mammalian cilia and flagella. This study uses the finite element method to investigate the behavior of C. reinhardtii swimming from nano-scale to micro-scale. At the device-level, micro-scale modeling indicates that well-designed acoustic microfluidic devices can be used to trap groups …

Design & Delivery Of Automated Winston-Lutz Test For Isocentric & Off-Axis Delivery Stability Utilizing Truebeam Developer Mode & Electronic Portal Imaging Device, Mahmoud Mohammad Yaqoub

UNLV Theses, Dissertations, Professional Papers, and Capstones

The uncertainties in treatment delivery cannot be ignored in radiation therapy. Thus, the quality assurance QA tests are very important task of the medical physicist in clinical practice. Assuring the coincidence between the mechanical isocenter of the Linear Accelerator (LINAC) and its radiation beams isocenter is one of the most important qualities need to be tested, and the Winston Lust (WL) test is the

most popular technique to perform this task, especially for the treatment modalities which need high precision in beam delivery such as the stereotactic radiosurgery/stereotactic body radiotherapy (SRS/SBRT). The linear accelerator-based SRS/SBRT is a well-established method in …

A Numerical Investigation Of Bio-Inspired Scaffolds And Surface Textures, Yucong Gu

Graduate Theses and Dissertations

Synthetic scaffolds are widely used as implants to repair bone fracture. Without a proper design, scaffolds could pose significant health risks to the patient and fail to heal the bone properly. A good synthetic scaffold needs to have high porosity and large pore size to allow new bone cells to form on it. However, a scaffold with higher porosity and larger pore size tends to have reduced mechanical strength. Thus, it is important to find a structural design which allows the implant to have a high porosity and large pore size while retaining high strength. In this research, a 3D-printable …

Knee Angles And Axes Crosstalk Correction In Gait, Cycling, And Elliptical Training Exercises, Jordan M. Skaro

Master's Theses

When conducting motion analysis using 3-dimensional motion capture technology, errors in marker placement on the knee results in a widely observed phenomenon known as “crosstalk” [1-18] in calculated knee joint angles (i.e., flexion-extension (FE), adduction-abduction (AA), internal-external rotation (IE)). Principal Component Analysis (PCA) has recently been proposed as a post hoc method to reduce crosstalk errors and operates by minimizing the correlation between the knee angles [1, 2]. However, recent studies that have used PCA have neither considered exercises, such as cycling (C) and elliptical training (E), other than gait (G) nor estimated the corrected knee axes following PCA correction. …

Effects Of Hydration And Mineralization On The Mechanical Behavior Of Collagen Fibrils, Marco Fielder

Graduate Theses and Dissertations

Bone is a composite biomaterial with a structural load-bearing function. Understanding the biomechanics of bone is important for characterizing factors such as age, trauma, or disease, and in the development of scaffolds for tissue engineering and bioinspired materials. At the nanoscale, bone is primarily composed of collagen protein, apatite crystals, and water. Though several studies have characterized nanoscale bone mechanics as the mineral content changes, the effect of water, mineral, and carbon nanotube (CNT) content and distribution in fibril gap and overlap regions is unexplored. This study used molecular dynamics to investigate the change in collagen fibril deformation mechanisms as …

Effect Of Shot Peening On Stress Corrosion Behavior Of Biodegradable Magnesium We43, Tejaswita Patil

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

Conventionally used metals for orthopedic devices made of titanium, stainless steel, and Co-Cr alloys are designed to be permanently implanted. However, long-term complications arise and a secondary implant removal surgery is often necessary. A mismatch in stiffness between the bone and implant results in stress shielding that negatively affects bone density. To overcome these problems, magnesium alloys (e.g., WE34) are favored due to a lower Young’s modulus (45 GPa) and biodegradability. The critical technical barrier with magnesium alloys is their high corrosion rate in physiological (salt-based) environments. One solution is to use surface treatments, such as shot peening (SP), to …

Uncertainty In Optical Particulate Counting Sensors, Jared Todd Blanchard

Undergraduate Honors Theses

To mitigate the health problems and environmental damage caused by the burning of biomass in homes across the developing world, there is an international effort to design clean burning cookstoves that burn with greater efficiency and emit fewer harmful substances. An important tool for gauging the effectiveness of these alternate stoves is the optical particulate counting (OPC) sensor, which comes in many varieties. To facilitate comparison between measurements from different models, a mathematical model and uncertainty analysis method for OPC’s have been developed. These may be applied to any light-scattering OPC. In addition, a low-cost physical system was developed to …

Materials Design With Polylactic Acid-Polyethylene Glycol Blends Using 3d Printing And For Medical Applications., Jeremiah R. Bauer

Electronic Theses and Dissertations

This thesis is an examination of two material systems derived from polylactic acid (PLA) and polyethylene glycol (PEG). PLA is a polymer commonly sourced from renewable sources such as starches and sugars. It is a relatively strong, biodegradable polymer, making it ideal for use in the body. Even though it has a relative high strength, PLA is also brittle leading to the use of plasticizers to increase flexibility. One such plasticizer is PEG, which is a material that can exist at room temperature as either a thin liquid, or a hard waxy solid depending on the molecular weight. The first …

Optimal Mixed Tracking/Impedance Control With Application To Transfemoral Prostheses With Energy Regeneration, Gholamreza Khademi, Hanieh Mohammadi, Hanz Richter, Daniel J. Simon

Mechanical Engineering Faculty Publications

We design an optimal passivitybased tracking/impedance control system for a robotic manipulator with energy regenerative electronics, where the manipulator has both actively and semi-actively controlled joints. The semi-active joints are driven by a regenerative actuator that includes an energy-storing element. Method: External forces can have a large influence on energy regeneration characteristics. Impedance control is used to impose a desired relationship between external forces and deviation from reference trajectories. Multi-objective optimization (MOO) is used to obtain optimal impedance parameters and control gains to compromise between the two conflicting objectives of trajectory tracking and energy regeneration. We solve the MOO problem …

Ring And Peg Simulation For Minimally Invasive Surgical Robot, Evan Brown

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

Surgical procedures utilizing minimally invasive laparoscopic techniques have shown less complications, better cosmetic results, and less time in the hospital than conventional surgery. These advantages are partially offset by inherent difficulties of the procedures which include an inverted control scheme, instrument clashing, and loss of triangulation. Surgical robots have been designed to overcome the limitations, the Da Vinci being the most widely used. A dexterous in vivo, two-armed robot, designed to enter an insufflated abdomen with a limited insertion profile and expand to perform a variety of operations, has been created as a less expensive, versatile alternative to the Da …

Multi-Scale Fluid Flow Analysis Of The Cardiovascular System, Zaid Mahmood

Doctoral Dissertations and Master's Theses

The hypoplastic left heart syndrome (HLHS) is one of the rarest congenital heart diseases affecting infants. Out of 150 babies born, one baby suffers from congenital heart disease. Furthermore, nine percent out of those suffering from congenital heart disease specifically suffer from hypoplastic left heart syndrome (HLHS). To this end, the Fontan operation which is a procedure to generate a harmonic blood flow in single functioning ventricle patients has been executed to palliate HLHS patients. In this operation, the inferior vena cava (IVC) and the superior vena cava (SVC), carrying the low-oxygenated blood returning from the lower and upper body …