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Full-Text Articles in Engineering
Local Hemodynamic Changes Caused By Main Branch Stent Implantation And Subsequent Side Branch Balloon Angioplasty In A Representative Coronary Bifurcation, Andrew R. Williams, Bon-Kwon Koo, Timothy J. Gundert, Peter J. Fitzgerald, John F. Ladisa Jr.
Local Hemodynamic Changes Caused By Main Branch Stent Implantation And Subsequent Side Branch Balloon Angioplasty In A Representative Coronary Bifurcation, Andrew R. Williams, Bon-Kwon Koo, Timothy J. Gundert, Peter J. Fitzgerald, John F. Ladisa Jr.
Biomedical Engineering Faculty Research and Publications
Abnormal blood flow patterns promoting inflammation, cellular proliferation, and thrombosis may be established by local changes in vessel geometry after stent implantation in bifurcation lesions. Our objective was to quantify altered hemodynamics due to main vessel (MV) stenting and subsequent virtual side branch (SB) angioplasty in a coronary bifurcation by using computational fluid dynamics (CFD) analysis. CFD models were generated from representative vascular dimensions and intravascular ultrasound images. Time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and fractional flow reserve (FFR) were quantified. None of the luminal surface was exposed to low TAWSS (/cm2) in the nondiseased bifurcation model. …
On The Effective Elastic Properties Of Macroscopically Isotropic Media Containing Randomly Dispersed Spherical Particles, D. Cojocaru, Anette M. Karlsson
On The Effective Elastic Properties Of Macroscopically Isotropic Media Containing Randomly Dispersed Spherical Particles, D. Cojocaru, Anette M. Karlsson
Mechanical Engineering Faculty Publications
computational scheme for estimating the effective elastic properties of a particle reinforced matrix is investigated. The randomly distributed same-sized spherical particles are assumed to result in a composite material that is macroscopically isotropic. The scheme results in a computational efficient method to establish the correct bulk and shear moduli by representing the three-dimensional (3D) structure in a two-dimensional configuration. To this end, the statistically equivalent area fraction is defined in this work, which depends on two parameters: the particle volume fraction and the number of particles in the 3D volume element. We suggest that using the statistically equivalent area fraction,introduced …
A Linear Finite Element Acoustic Fluid-Structure Model Of Ultrasonic Angioplasty In Vivo, Mark Wylie, Garrett Mcguinness, Graham Gavin
A Linear Finite Element Acoustic Fluid-Structure Model Of Ultrasonic Angioplasty In Vivo, Mark Wylie, Garrett Mcguinness, Graham Gavin
Articles
The delivery of high-power ultrasonic energy via small diameter wire waveguides represents a new alternative therapy for the treatment of chronic totally occluded arteries (CTOs). This type of energy manifests itself as a mechanical vibration at the distal-tip of the waveguide with amplitudes of vibration up to 60 µm and at frequencies of 20- 50 kHz. Disruption of diseased tissue is reported to be a result of direct mechanical ablation, cavitation, pressure components and acoustic streaming and that ablation was only evident above the cavitation threshold. This work presents a linear finite element acoustic fluid-structure model of an ultrasonic angioplasty …
Viscoelastic Effects Of Unreamed Intramedullary Nailing, G. Noble, Timothy L. Norman
Viscoelastic Effects Of Unreamed Intramedullary Nailing, G. Noble, Timothy L. Norman
Engineering and Computer Science Faculty Presentations
No abstract provided.
Dielectrophoretic Choking Phenomenon In A Converging-Diverging Microchannel, Ye Ai, Shizhi Qian, Sheng Liu, Sang W. Joo
Dielectrophoretic Choking Phenomenon In A Converging-Diverging Microchannel, Ye Ai, Shizhi Qian, Sheng Liu, Sang W. Joo
Mechanical & Aerospace Engineering Faculty Publications
Experiments show that particles smaller than the throat size of converging-diverging microchannels can sometimes be trapped near the throat. This critical phenomenon is associated with the negative dc dielectrophoresis arising from nonuniform electric fields in the microchannels. A finite-element model, accounting for the particle-fluid-electric field interactions, is employed to investigate the conditions for this dielectrophoretic (DEP) choking in a converging-diverging microchannel for the first time. It is shown quantitatively that the DEP choking occurs for high nonuniformity of electric fields, high ratio of particle size to throat size, and high ratio of particle's zeta potential to that of microchannel. © …
Design Of Functionally Graded Carbon Coatings Against Contact Damage, Rajnish K. Singh, Zhifeng Zhou, Lawrence Kwok Yan Li, Paul Munroe, Mark Hoffman, Zonghan Xie
Design Of Functionally Graded Carbon Coatings Against Contact Damage, Rajnish K. Singh, Zhifeng Zhou, Lawrence Kwok Yan Li, Paul Munroe, Mark Hoffman, Zonghan Xie
Research outputs pre 2011
Three different functionally graded amorphous carbon (a-C) thin films were deposited on to aluminium substrates using a closed-field unbalanced magnetron sputtering ion plating method. The closed-field configuration prohibits the loss of secondary electrons and consequently enhances the plasma density significantly. The functional gradient of the a-C films was achieved by varying the bias voltage linearly during deposition. Three graded a-C systems possessing different variations in Young's modulus were deposited with the highest Young's modulus at the (i) top surface, (ii) interface or (iii) middle of the film. Of the three systems investigated, the one with the highest Young's modulus at …
Finite Element Analysis Of Cracks In Aging Aircraft Structures With Bonded Composite-Patch Repairs, Linxia Gu, Ananth Ram Mahanth Kasavajhala, Shijia Zhao
Finite Element Analysis Of Cracks In Aging Aircraft Structures With Bonded Composite-Patch Repairs, Linxia Gu, Ananth Ram Mahanth Kasavajhala, Shijia Zhao
Department of Mechanical and Materials Engineering: Faculty Publications
Bonded composite-patch repair has been used to transfer load from cracked structures to the reinforcement such that subsequent crack propagation is reduced. In this study,the mechanical behavior of a single edge v-notch A17075-T6 plate repaired with 1-ply and 4-ply composite patches was investigated through the finite element method. Contour integral method was used to define and evaluate the stress intensity factors at the crack tip. The effect of the adhesive epoxy film, patch material, thickness and ply orientations on the evolution of the stress intensity factor (SIF) of the repaired structure was examined. The results indicated that the SIF of …
Computational Structural Modelling Of Coronary Stent Deployment: A Review, David Martin, Fergal Boyle
Computational Structural Modelling Of Coronary Stent Deployment: A Review, David Martin, Fergal Boyle
Articles
The finite element (FE) method is a powerful investigative tool in the field of biomedical engineering, particularly in the analysis of medical devices such as coronary stents whose performance is extremely difficult to evaluate in vivo. In recent years, a number of FE studies have been carried out to simulate the deployment of coronary stents, and the results of these studies have been utilised to assess and optimise the performance of these devices. The aim of this paper is to provide a thorough review of the state-of-the-art research in this area, discussing the aims, methods and conclusions drawn from a …