Development Of A Robotic Platform For Upper Limb Rehabilitation,
2012
Technological University Dublin
Development Of A Robotic Platform For Upper Limb Rehabilitation, Stephen Curran, Nigel Kent, David Kennedy, James Conlon
Conference Papers
The aim of this project is to develop a rehabilitation robot intended for use in a non-specialised or domestic setting. Robots have been shown to have a positive effect on limb rehabilitation and developing rehabilitation robots for use outside of specialist rehabilitation centres could be beneficial in terms of access to, intensity and cost of treatment. The device is intended for the rehabilitation of the shoulder/elbow region of the upper limbs. The design requirements for such a device mean that it must be low cost, portable, robust and have a detailed focus on safety. Other areas of interest pertaining to …
Multistable Shape-Shifting Surfaces (Mssss),
2012
University of South Florida
Multistable Shape-Shifting Surfaces (Mssss), Paul Joseph Montalbano
USF Tampa Graduate Theses and Dissertations
This paper presents designs for Multistable Shape-Shifting Surfaces (MSSS) by introducing bistability into the Shape-Shifting Surface (SSS). SSSs are defined as surfaces that retain their effectiveness as a physical barrier while undergoing changes in shape. The addition of bistability to the SSS gives the surface multiple distinct positions in which it remains when shifted to, i.e. by designing bistability into a single SSS link, the SSS unit cell can change into multiple shapes, and stabilize within the resulting shape, while maintaining integrity against various forms of external assaults normal to its surface. Planar stable configurations of the unit cell include, …
Shelf-Scale Mapping Of Fish Distribution Using Active And Passive Acoustics,
2012
University of South Florida
Shelf-Scale Mapping Of Fish Distribution Using Active And Passive Acoustics, Carrie Christy Wall
USF Tampa Graduate Theses and Dissertations
Fish sound production has been associated with courtship and spawning behavior. Acoustic recordings of fish sounds can be used to identify distribution and behavior. Passive acoustic monitoring (PAM) can record large amounts of acoustic data in a specific area for days to years. These data can be collected in remote locations under potentially unsafe seas throughout a 24-hour period providing datasets unattainable using observer-based methods. However, the instruments must withstand the caustic ocean environment and be retrieved to obtain the recorded data. This can prove difficult due to the risk of PAMs being lost, stolen or damaged, especially in highly …
Numerical Simulation Of Natural Convection In Rectangular Enclosures Of Varying Aspect Ratios And Its Feasibility In Environmental Impact Management Studies,
2012
Georgia Southern University
Numerical Simulation Of Natural Convection In Rectangular Enclosures Of Varying Aspect Ratios And Its Feasibility In Environmental Impact Management Studies, Charles R. Walker
College of Graduate Studies: Theses & Dissertations
Author's abstract: Numerical simulation was used to investigate natural convection in horizontal and vertical enclosures with and without an internal heat source. Natural convection in rectangular enclosures is found in many real-world applications. Included in these applications are the energy efficient design of buildings, operation and safety of nuclear reactors, solar collector design, passive energy storage, heat transfer across multi-pane windows, thermo-electric refrigeration and heating devices, and the design-for-mitigation of optical distortion in large-scale laser systems. Considering all these applications, especially controlling heat transfer in nuclear power plants, knowledge and research results of natural convection in enclosure play a vital …
Development And Validation Of Probabilistic Fatigue Models Containing Out-Life Suspensions,
2012
Georgia Southern University
Development And Validation Of Probabilistic Fatigue Models Containing Out-Life Suspensions, Noel S. Murray
College of Graduate Studies: Theses & Dissertations
Author's abstract: In the area of reliability engineering it is necessary to be confident that a component or system of components will not fail under use for safety and cost reasons. One major mechanism of failure to a mechanical component is fatigue. This is the repetitious motion of loading and unloading of the material, typically below the ultimate tensile strength of the material, which ultimately leads to a catastrophic failure. To ensure this does not happen, engineers design components based on tests to determine the life of these components. These tests are typically conducted on a bench type tester in …
A Planning Tool To Predict The Welding Angle In Laser Metal Deposition,
2012
Missouri University of Science and Technology
A Planning Tool To Predict The Welding Angle In Laser Metal Deposition, Sriram Prabhu
Masters Theses
"Research in Laser Metal Deposition (LMD) has been done rigorously in the past. However, the main challenge that still exists is the production of complex part geometries having overhang features. Production of such features requires individual tracks with a high aspect ratio and wider bead angle. The use of destructible/ non-destructible support structures involves costly post production operations which increase production cost. Tilting or moving the deposition surface can be useful to create overhangs but are applicable only to special cases. Since such techniques have to be used by the manufacturing community, the techniques need to be simple in calculation …
Computationally Efficient Finite Element Models Of The Lumbar Spine For The Evaluation Of Spine Mechanics And Device Performance,
2012
University of Denver
Computationally Efficient Finite Element Models Of The Lumbar Spine For The Evaluation Of Spine Mechanics And Device Performance, Sean D. Smith
Electronic Theses and Dissertations
Finite Element models of the lumbar spine are commonly used for the study of spine mechanics and device performance, but have limited usefulness in some applications such as clinical and design phase assessments due to long analysis times. In this study a computationally efficient L4-L5 FSU model and a L1-Sacrum multi-segment model were developed and validated. The FSU is a functional spine unit consisting of two adjacent vertebral bodies, in this case L4 and L5. The multi-segment model consists of all lumbar vertebrae and the sacrum. The models are able to accurately predict spine kinematics with significantly reduced analysis times, …
Experimental Testing And Finite-Element Modeling To Evaluate The Effects Of Aggregate Angularity On Bituminous Mixture Performance,
2012
University of Nebraska–Lincoln
Experimental Testing And Finite-Element Modeling To Evaluate The Effects Of Aggregate Angularity On Bituminous Mixture Performance, Leonardo T. Souza, Yong-Rak Kim, Flavio V. Souza, Leandro S. Castro
Department of Engineering Mechanics: Faculty Publications
This study evaluates the effects of aggregate angularity in bituminous mixtures. Previous studies have predominantly focused on the effects of aggregate angularity on the resistance to permanent deformation, while little work has investigated the role of aggregate angularity related to mixture volumetrics and fatigue fracture performance. To investigate the effect of aggregate angularity on mixture performance and characteristics, five mixes with different combinations of coarse and fine aggregate angularity are evaluated by performing the uniaxial static creep test and the indirect tensile fracture energy test. The asphalt pavement analyzer test is also performed with five-year field project mixtures. Fracture energy …
Explicit Finite Element Modeling Of The Human Lumbar Spine,
2012
University of Denver
Explicit Finite Element Modeling Of The Human Lumbar Spine, Milind Rao
Electronic Theses and Dissertations
Validated finite element (FE) models of the functional spinal unit (FSU) and lumbar spine are essential in design-phase device development and in assessing the mechanics associated with normal spine function and degenerative disc disease (DDD), as well as the impact of fusion and total disc replacement (TDR). Although experimental data from fully intact specimens can be used for model calibration and validation, the contributions from the individual structures (disc, facets, and ligaments) may be inappropriately distributed. Hence, creation of decompression conditions or device implantations that require structure removal may not have the proper resulting mechanics. An explicit FE formulation may …
Systems And Synthetic Biology Of The Vessel Wall,
2012
Imperial College London
Systems And Synthetic Biology Of The Vessel Wall, Jennifer Frueh, Nataly Maimari, Ying Lui, Zoltan Kis, Vikram Mehta, Negin Pormehr, Calum Grant, Emmanuel Chalkias, Mika Falck-Hansen, Sandra Bovens, Ryan M. Pedrigi, Taka Homma, Gianfillippo Coppola, Rob Krams
Department of Mechanical and Materials Engineering: Faculty Publications
Atherosclerosis is intimately coupled to blood flow by the presence of predilection sites. The coupling is through mechanotransduction of endothelial cells and approximately 2000 gene are associated with this process. This paper describes a new platform to study and identify new signalling pathways in endothelial cells covering an atherosclerotic plaque. The identified networks are synthesized in primary cells to study their reaction to flow. This synthetic approach might lead to new insights and drug targets.
Nanotopographic Cell Culture Substrate:
Polymer-Demixed Nanotextured Films
Under Cell Culture Conditions,
2012
University of Nebraska–Lincoln
Nanotopographic Cell Culture Substrate: Polymer-Demixed Nanotextured Films Under Cell Culture Conditions, Jung Yul Lim, Christopher A. Siedlecki, Henry J. Donahue
Department of Mechanical and Materials Engineering: Faculty Publications
Modulating physical cell culture environments via nanoscale substrate topographic modification has recently been of significant interest in regenerative medicine. Many studies have utilized a polymer-demixing technique to produce nanotextured films and showed that cellular adhesion, proliferation, and differentiation could be regulated by the shape and scale of the polymer-demixed nanotopographies. However, little attention has been paid to the topographic fidelity of the polymer-demixed films when exposed to cell culture conditions. In this brief article, two polymer-demixing systems were employed to assess topographic changes in polymer-demixed films after fibronectin (FN) extracellular matrix protein adsorption and after incubation in phosphate-buffered saline at …
Usability Assessment Of Two Different Control
Modes For The Master Console Of A Laparoscopic
Surgical Robot,
2012
Wilkes University
Usability Assessment Of Two Different Control Modes For The Master Console Of A Laparoscopic Surgical Robot, Xiaoli Zhang, Carl A. Nelson, Dmitry Oleynikov
Department of Mechanical and Materials Engineering: Faculty Publications
The objective of this study is to evaluate potential interface control modes for a compact fourdegree- of-freedom (4-DOF) surgical robot. The goal is to improve robot usability by incorporating a sophisticated haptics-capable interface. Two control modes were developed using a commercially available haptic joystick: (1) a virtually point-constrained interface providing an analog for constrained laparoscopic motion (3-DOF rotation and 1-DOF translation), and (2) an unconstrained Cartesian input interface mapping more directly to the surgical tool tip motions. Subjects (n = 5) successfully performed tissue identification and manipulation tasks in an animal model in point-constrained and unconstrained control modes, respectively, with …
Tool Sequence Trends In Minimally Invasive
Surgery: Statistical Analysis And Implications For
Predictive Control Of Multifunction Instruments,
2012
University of Nebraska-Lincoln
Tool Sequence Trends In Minimally Invasive Surgery: Statistical Analysis And Implications For Predictive Control Of Multifunction Instruments, Carl A. Nelson, Evan Luxon, Dmitry Oleynikov
Department of Mechanical and Materials Engineering: Faculty Publications
This paper presents an analysis of 67 minimally invasive surgical procedures covering 11 different procedure types to determine patterns of tool use. A new graph-theoretic approach was taken to organize and analyze the data. Through grouping surgeries by type, trends of common tool changes were identified. Using the concept of signal/noise ratio, these trends were found to be statistically strong. The tool-use trends were used to generate tool placement patterns for modular (multi-tool, cartridge-type) surgical tool systems, and the same 67 surgeries were numerically simulated to determine the optimality of these tool arrangements. The results indicate that aggregated tool-use data …
The Impact Of Wire Stent
Fabrication Technique On The
Performance Of Stent Placement,
2012
University of Nebraska-Lincoln
The Impact Of Wire Stent Fabrication Technique On The Performance Of Stent Placement, Shijia Zhao, Xiangyi (Cheryl) Liu, Linxia Gu
Department of Mechanical and Materials Engineering: Faculty Publications
Braided wire stents demonstrate distinct characteristics compared to welded ones. In this study, both braided and welded wire stents with the same nominal dimensions were crimped inside a sheath and then deployed into a stenosed artery using finite element analysis. The braided wire stent was generated by overlapping wires to form crisscross shape. A welded wire stent was created by welding the intersection points of wires to avoid sliding between wires. The effect of fabrication technique on mechanical behavior of Nitinol wire stents was evaluated. The results showed that relative sliding between wires reduced the deformation of the braided stent, …
Arterial Wall Mechanics And Clinical Implications After Coronary Stenting: Comparisons Of Three Stent Designs,
2012
University of Nebraska-Lincoln
Arterial Wall Mechanics And Clinical Implications After Coronary Stenting: Comparisons Of Three Stent Designs, Linxia Gu, Shijia Zhao, Stacey R. Froemming
Department of Mechanical and Materials Engineering: Faculty Publications
The goal of this work is to quantitatively assess the relationship between the reported restenosis rates and stent induced arterial stress or strain parameters through finite element method. The impact of three stent designs (Palmaz–Schatz stent, Express stent, and Multilink Vision stent) on the arterial stress distributions were characterized. The influences of initial stent deployment location, stent-tissue friction, and plaque properties on the arterial stresses were also investigated. Higher arterial stresses were observed at the proximal end of the plaque. The Multilink–Vision stent induced lesser stress concentrations due to the high stiffness of the Cobalt Chromium material and thinner strut …
Analysis Of A Monolithic, Two-Dimensional
Array Of Quartz Crystal Microbalances
Loaded By Mass Layers
With Nonuniform Thickness,
2012
University of Nebraska-Lincoln
Analysis Of A Monolithic, Two-Dimensional Array Of Quartz Crystal Microbalances Loaded By Mass Layers With Nonuniform Thickness, Nan Liu, J. S. Yang, Ji Wang
Department of Mechanical and Materials Engineering: Faculty Publications
We study free thickness-shear vibrations of a monolithic, two-dimensional, and periodic array of quartz crystal microbalances loaded by mass layers with gradually varying thickness. A theoretical analysis is performed using Mindlin’s two-dimensional plate equation. It is shown that the problem is mathematically governed by Mathieu’s equation with a spatially varying coefficient. A periodic solution for resonant frequencies and modes is obtained and used to examine the effects of the mass layers. Results show that the vibration may be trapped or untrapped under the mass layers. The trapped modes decay differently in the two in-plane directions of the plate. The mode …
Shear-Horizontal Vibration Modes
Of An Oblate Elliptical Cylinder
And Energy Trapping In Contoured
Acoustic Wave Resonators,
2012
University of Nebraska-Lincoln
Shear-Horizontal Vibration Modes Of An Oblate Elliptical Cylinder And Energy Trapping In Contoured Acoustic Wave Resonators, Huijing He, Jiashi Yang, John A. Kosinski
Department of Mechanical and Materials Engineering: Faculty Publications
We study shear-horizontal free vibrations of an elastic cylinder with an oblate elliptical cross section and a traction-free surface. Exact vibration modes and frequencies are obtained. The results show the existence of thickness-shear and thickness-twist modes. The energy-trapping behavior of these modes is examined. Trapped modes are found wherein the vibration energy is largely confined to the central portion of the cross section and little vibration energy is found at the edges. It is also shown that face-shear modes are not allowed in such a cylinder. The results are useful for the understanding of the energy trapping phenomenon in contoured …
Moisture Damage Characterization Of Warm-Mix Asphalt Mixtures Based On Laboratory-Field Evaluation,
2012
Kyung Hee University
Moisture Damage Characterization Of Warm-Mix Asphalt Mixtures Based On Laboratory-Field Evaluation, Yong-Rak Kim, Jun Zhang, Hoki Ban
Department of Mechanical and Materials Engineering: Faculty Publications
This study presents laboratory evaluation integrated with field performance to examine two widely used warm-mix asphalt (WMA) approaches—foaming and emulsion technology. For a more realistic evaluation of the WMA approaches, trial pavement sections of the WMA mixtures and their counterpart hot-mix asphalt (HMA) mixtures were implemented in Antelope County, Nebraska. Field-mixed loose mixtures collected at the time of paving were transported to the laboratories to conduct various experimental evaluations of the individual mixtures. Among the laboratory tests, three (two conventional and one newly attempted) were performed to characterize moisture damage potential which is the primary focus of this study. From …
Monitoring The Wall Mechanics During Stent Deployment In A Vessel,
2012
University of Nebraska-Lincoln
Monitoring The Wall Mechanics During Stent Deployment In A Vessel, Brian Steinert, Shijia Zhao, Linxia Gu
Department of Mechanical and Materials Engineering: Faculty Publications
Clinical trials have reported different restenosis rates for various stent designs . It is speculated that stentinduced strain concentrations on the arterial wall lead to tissue injury, which initiates restenosis . This hypothesis needs further investigations including better quantifications of non-uniform strain distribution on the artery following stent implantation. A non-contact surface strain measurement method for the stented artery is presented in this work. ARAMIS stereo optical surface strain measurement system uses two optical high speed cameras to capture the motion of each reference point, and resolve three dimensional strains over the deforming surface. As a mesh stent is deployed …
Adjusting A Level At Which To Generate A New Tone With A Current Generated Tone,
2012
Missouri University of Science and Technology
Adjusting A Level At Which To Generate A New Tone With A Current Generated Tone, M. Nakagawa, Shun Takai
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Provided are a tone control device and a method for adjusting a volume level at which to generate a new tone and at least one current tone according to a target volume level and a current volume level. A note-on event associated with a received volume level is received from an input device. A current volume level is processed to determine a new volume level in response to receiving the note-on event while generating at least one current tone at the current volume level. The at least one current tone and a new tone associated with the received note-on event …
