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Here you will find presentations given at COMSOL Conferences around the globe. The presentations explore the innovative research and products designed by your peers using COMSOL Multiphysics. Research topics span a wide array of industries and application areas, including the electrical, mechanical, fluid, and chemical disciplines. Use the Quick Search to find presentations pertaining to your application area.

Updated Results of Singlet Oxygen Modeling Incorporating Local Vascular Diffusion for PDT - new

R. Penjweini[1], M. M. Kim[1], T. C. Zhu[1]
[1]Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA

Introduction: Singlet oxygen (¹O₂) has a critical role in the cell-killing mechanism of photodynamic therapy (PDT). Therefore, in this study, the distance-dependent reacted ¹O₂ is numerically calculated using finite-element method (FEM). Herein, we use a model [Ref. 1] that has been previously developed to incorporate the diffusion equation for the light transport in tissue and the ...

Temperature Excursions at the Pulp-Dentin Junction during the Curing of Light-Activated Dental Restorations

M. Jakubinek[1,2], C. Neill[1], C. Felix[3], R. Price[2,3], M. White[1,2]

[1]Departments of Chemistry and Physics, Dalhousie University, Halifax, NS, Canada
[2]Institute for Research in Materials, Dalhousie University, Halifax, NS, Canada
[3]Department of Dental Clinical Sciences, Dalhousie University, Halifax, NS, Canada

Heat produced during the curing of light-activated dental restorations could damage the dental pulp. Given the prevalence of composite restorations and the importance of avoiding injury to the pulp, efforts should be made to minimize the temperature increase that occurs at the pulp-dentin junction during light-curing. In this investigation we develop and evaluate a COMSOL Multiphysics FEM tooth ...

Search for a Suitable Numerical Model for Electrical Stimulation: from the Electric Double Layer to Electrokinetics, Confrontation with Impedance Measurements

P. Pham, R. Scapolan, C. Rubeck, and F. Dupont
CEA-LETI-MINATEC, Grenoble, France

Electrical Stimulation is widely used today for Deep Brain Stimulation treatments and retinal prostheses. The Electrical Double Layer formed at the interface between the electrode surface and the extracellular medium is considered thru the linear Helmholtz model and the nonlinear more realistic modified Poisson Boltzmann model. These different models, solved using COMSOL Multiphysics, are ...

Investigation Of Bone Marrow Stem Cells In The Bone Marrow Niche In An In Vitro System

P. Lezuo, M. Stoddart, and M. Alini
AO Research Institute, Davos, Grison, Switzerland

We aim to develop an in vitro culture system to mimic the human bone marrow stem cell niche in an artificial perfusion bioreactor environment to culture human adult stem cells. State of the art human bone marrow stem cell research shows that even smallest changes in the physical, thermo dynamical or biochemical environment induce a differentiation of human bone marrow stem cells into other cell ...

Evaluation of Performance of Enzymatic Biofuel Cells with Microelectrode Arrays Inside a Blood Artery via Finite Element Approach

C. Wang[1], Y. Song[1]
[1]Florida International University, Miami, FL, USA

Enzymatic biofuel cells (EBFCs) are considered as a promising candidate for powering miniature implantable devices. In order to predict the performance in the human blood artery, we simulated a 3D EBFC chip with highly dense micro-electrode arrays. In this simulation using COMSOL Multiphysics®, we applied the 1) Michaelis Menten equation; 2) Nernst potential equation; 3) Navier Strokes velocity, ...

Local Electroporation of Single Adherent Cells by Micro-Structured Needle Electrodes

K. K. Sriperumbudur[1], P. J. Koester[1], M. Stubbe[1], C. Tautorat[1], J. Held[2], W. Baumann[1], and J. Gimsa[1]
[1] University of Rostock, Chair of Biophysics, Gertrudenstr. 11a, 18057 Rostock, Germany
[2] Microsystem Material Laboratory, Department of Microsystems Engineering (IMTEK), University of Freiburg, Germany

In spite of its low throughput, Patch-Clamp is the established method for intracellular measurements of the transmembrane potential. To address this problem, we have developed new biosensor-chips with micro-structured needle electrodes (MNEs). MNE-penetration of single cells growing on the MNE-tips leads to a situation comparable to the whole-cell mode in classical Patch Clamp. MNE-penetration ...

Modeling of snRNP Motion in the Nucleoplasm

M. Blaziková[1], J. Malínský[2], D. Stanek[3], and P. Herman[1]
[1]Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic
[2]Institute of Experimental Medicine, Prague, Czech Republic
[3]Institute of Molecular Genetics, Prague, Czech Republic

Small nuclear ribonucleoprotein particles (snRNPs) are essential supramolecular complexes involved in pre-mRNA splicing, the process of post-transcriptional RNA modifications. The particles undergo complex assembly steps inside the cell nucleus in a highly dynamic compartment called the Cajal body. We have previously shown that the free diffusion model does not fully describe the snRNP motion ...

Wireless RF Digital System for Mouth-Embedded Multi-Sensor Communication

I.M. Abdel-Motaleb[1], J. Lavrencik [1]
[1]Department of Electrical Engineering, Northern Illinois University, DeKalb, IL, USA

There is urgent need to monitor dental and oral diseases, such as tooth decay, gum diseases, and teeth grinding. Such monitoring can be achieved by embedding sensors in the mouth. This technique faces some difficulties. The first is how the power needed for the operation of the sensors and the associated electronic chips can be generated. This power can be generated using the pressure exerted by ...

Numerical Validation of the Efficiency of Dual-Frequency Radiofrequency Ablation

A. Candeo[1] and F. Dughiero[1]
[1]Department Electrical Engineering, University of Padova, Padova, Italy

Radiofrequency Ablation (RFA) represents a valid alternative for treating liver metastases in medically complicated patients. Conventional devices currently operate at 500 kHz, due to good conducting properties of tissues. However, the use of lower frequencies (i.e. 20 kHz) has been recently reported to enhance the treatment effectiveness, due to a more pronounced difference in electrical ...

Hemodynamic Therapy of Middle Cerebral Artery Vasospasm Guided by a Multiphase Model of Oxygen Transport

S. Conrad[1,2], P. Chittiboina[3], and B. Guthikonda[3]

[1]Department of Bioinformatics and Computational Biology, Louisiana State University Health Sciences Center, Shreveport, LA, USA
[2]Department of Biomedical Engineering, Louisiana Tech University, Ruston, LA, USA
[3]Department of Neurosurgery, Louisiana State University Health Sciences Center, Shreveport, LA, USA

Cerebral vasospasm is a complication of subarachnoid hemorrhage and other neurosurgical emergencies that reduce blood flow to the brain. Part of the approach to management of vasospasm is to improve flow through the stenotic areas by reducing by decreasing blood viscosity and enhancing flow through the stenosis. To examine the interaction of these factors, we applied computational fluid dynamics ...