Aqui você encontrará apresentações realizadas nas Conferências de Usuários COMSOL de todo o mundo. As apresentações englobam pesquisas e produtos inovadores feitas por engenheiros e cientistas usando o COMSOL Multiphysics. Os tópicos abramgem uma grande gama de indústrias e aplicações, como elétrica, mecânica, escoamento e química. Use a função de busca "Quick Search" para encontrar apresentações na sua área de interesse.

Multiphysics Modeling of Cellular Arrays Using Periodic Minimal Surfaces – A Drug and Gene Delivery Application

J.I. Rey, A.J. Llewellyn, R.J. Connolly, J.P. Jimenez, A.M. Hoff, and R.A. Gilbert
University of South Florida, Tampa, FL, USA

Minimal surfaces are found in nature from crystalline structures to biological nano and micro structures such as biomembranes, and osseous formations in sea urchin. An application to electrically mediated drug and gene delivery is presented. Periodic level surfaces which approximate minimal surfaces are used to generate a geometric representation of tissue. A method to create such structures ...

Modeling of Retinal Electrical Stimulation Using a Micro Electrode Array Coupled with the Gouy-Chapman Electrical Double Layer Model to Investigate Stimulation Efficiency

F. Dupont, R. Scapolan, C. Condemine, J.F. Bêche, M. Belleville, and P. Pham
CEA, LETI, Minatec, Grenoble, France

The electrical stimulation for retinal implant has known significant improvements in the last decades with many implantations and experimentations. The ability to create better controlled and adapted signals to increase the efficiency in stimulation is a major objective. The aim of this study is to develop a numerical platform based on COMSOL Multiphysics to simulate different waveforms. The ...

Multiphysics Model of the NovaSure Endometrial Ablation Procedure

G.T. Martin[1], and L. Angelone[2]
[1]Hologic, Inc., Bedford, Massachusetts, USA
[2]Massachusetts General Hospital, Harvard Medical School, Marlborough, Massachusetts, USA

The NovaSure Endometrial Ablation System® is designed to remove the endometrial lining in the uterine cavity of women who suffer from menorrhagia. The NovaSure disposable device consists of a 2-pole, 4 electrode array that is inserted into the uterine cavity and deployed. We have developed a COMSOL Multiphysics model of the NovaSure ablation process. The model utilized COMSOL Multiphysics ...

Finite Element Analysis of Muscular Contractions from DC Pulses in the Liver

G. Long, D. Plescia, and P. Shires
Ethicon Endo-Surgery, Cincinnati, OH, USA

Thermal ablation of malignant tumors has been conducted in patients who are not candidates for surgery for more than ten years. Recently it has been shown that low energy DC pulses can cause cell necrosis. An undesirable characteristic of DC pulses in-vivo is the stimulation of skeletal muscle. The intensity of the contraction depends in part on the duration and height of the pulse. Through the ...

Physical and FEM Simulation of Microprobe Insertion into Brain Tissue

A. Eed Olamat, U. Hofmann, B. Pohl, and N. Nkemasong
University of Lübeck, Institute for Signal Processing, Lübeck, Germany

In order to investigate the implantation of microprobes into brain tissue, we developed a finite-element and a physical model to replace real biological tissue for mechanical testing. Penetrating forces of a tungsten indenter into a layered structure was investigated with different indentation speeds. Numerical and physical model are in good correspondence to each other and reproduce measured ...

Material Characterization Method Development: From Education to Design Optimization

C. Morgan[1], N. Kenkare[1], M. Williams[2], A. Peterson[2], and D. Williams[2]
[1]Alcon Eye Care Division of Novartis R&D, Duluth, GA
[2]Alcon Eye Care Division of Novartis R&D and Georgia Institute of Technology Co-op Program, GA

Introduction of silicone hydrogel contact lens materials provided products of unprecedented capability to deliver oxygen to the eye during wear. One additional material characteristic of interest is the material’s permeability to ions. This paper discusses descriptive tools and optimization of an impedance method of characterizing ion permeability. A physical model of conductive paper with ...

Some Clinical and Computational Studies On Haemodynamics In Stenosed Artery

A. Chanda, A.R. Choudhury, G. Ray, K. Dasgupta, and D. Nag
Jadavpur University, Kolkata, West Bengal, India

Atherosclerosis in arteries is caused by the formation of stenosis : fatty depositions, on the artery wall. In current medicine, the practice is to observe the maximum percentage occlusion at any arbitrary cross-section and diagnose the patient on that basis, which might not always present the real picture due to non-uniformity of the stenosis thickness. The present work attempts to simulate the ...

Modeling Bacterial Transport and Removal in a Constructed Wetland System

E. Engström, B. Balfors, and R. Thunvik
Royal Institute of Technology, Stockholm, Sweden

In this study we evaluate transport, retention and subsistence of Escherichia coli (E. coli), a common fecal indicator bacteria, in a model (2x1m) of a constructed wetland. Transport occurs in the unsaturated and saturated zone. Inactivation is accounted for as a kinetic first-order process. Retention is assumed to be dominated by solid-air-water interface straining and is modeled with a kinetic ...

An Assessment of the Suitability of the Body and Adult Head Coils for Transmission during Paediatric Magnetic Resonance Imaging

G.R. Cook[1], M.J. Graves[1], F.J. Robb[2], D.J. Lomas[1]
[1]Department of Radiology, University of Cambridge, Cambridge, United Kingdom
[2]General Electric Healthcare Coils, Aurora, Ohio, USA

MRI offers many advantages over other modalities and its lack of ionizing radiation is important for children, but can be limited by the radio-frequency (RF) coils available. This work calculates Specific Absorption Rate (SAR) and homogeneity of the RF transmit field (B1+) when imaging infants in adult coils. Two birdcage-type coils were loaded by a tissue model and their B1+ homogeneities ...

Optimization of 3D Layered Metal-Dielectric Stacks (MDS) for Near-Field Fluorescence Imaging

P.S. Tan[1], K. Elsayad[2], K. Heinze[1]
[1]Rudolf Virchow Center, University of Würzburg, Würzburg, Germany
[2]Research Institute of Molecular Pathology (IMP), Vienna, Austria

Nano-structures consisting of layered metal-dielectric stacks (MDSs) can be designed to have evanescent transmission and reflection coefficients that oscillate as a function of transverse wavevector and frequency. However, these structures always suffer from the material losses and surface roughness that are detrimental to image reconstruction. As such, we propose an optimized planar anisotropic ...