A. Candeo and F. Dughiero
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 ...
J. Hrdlicka, P. Cervenka, M. Pribyl, and D. Snita
Department of Chemical Engineering, Institute of Chemical Technology Prague, Prague, Czech Republic
In this paper we present results of the mathematical modeling of AC electroosmotic micropumps. Unlike others we use the full dynamic description, instead of the linearized model. Skewed hybrid discretization meshes are employed in order to accurately capture the main features of the studied system. Also, we introduce zig-zag electrode arrangements for traveling-wave electroosmotic micropumps. The ...
Image-Based Simulation of Electrical Impedance Techniques Applied on the Human Thorax for Cardio-Pulmonary Applications
F.K. Hermans, R.M. Heethaar, R.T. Cotton, and A. Harkara
VU University Medical Center, Amsterdam, The Netherlands
Simpleware Ltd., Exeter, United Kingdom
For medical diagnostic purposes there is an increasing need for non- (or minimal) invasive techniques to measure all kinds of parameters that can provide insight in the functioning of cells, organs or organ systems. Currently, Impedance Cardiography (ICG) is used for measurements of the heart and Electric Impedance Tomography (EIT) is used for investigating lung tissue condition. This paper ...
3-D Finite Element Modeling of Brain Edema: Initial Studies on Intracranial Pressure Using COMSOL Multiphysics®
X.G. Li, H. von Holst, J. Ho, and S. Kleiven
Division of Neuronic Engineering, KTH, Stockholm, Sweden
Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
Brain edema is one of the most common consequences of serious traumatic brain injuries which is usually accompanied with increased Intracranial Pressure (ICP) due to water content increment. A three dimensional finite element model of brain edema is used to study intracranial pressure in this paper. Three different boundary conditions at the end of Cerebral Spinal Fluid (CSF) were used to ...
Numerical Simulations Demonstrate Safe Vitrification and Warming of Embryos Using the Rapid-i™ Device
B.O.J. Johansson, Y.A. Tarakanov, H.J. Lehmann, and S.P. Apell
Department of Applied Physics, Chalmers University of Technology, Gothenburg, Sweden
Vitrolife Sweden AB, Västra Frölunda, Sweden
During cryopreservation of human embryos, ice crystal formation in the embryos or in surrounding media may cause cryodamage to them and can be lethal. A strategy to avoid this is the vitrification procedure when the embryo and the surrounding medium undergo the transition to glassy state rather than a crystalline one during cooling. Similarly, recrystallization in the embryo or the medium must be ...
X. Ma and J. Grabe
Institude for Geotechnics and Construction Management, Hamburg University of Technology, Hamburg, Germany
Natural groundwater flow can increase the efficiency of geothermal system. But groundwater flow is not available everywhere. A patented new idea is to use air injection well to create artificial flow in sandy or gritty soils. The governing equations of fluid flow and heat transfer problem were solved with the COMSOL’s Earth Science Module.
A. Schwen, G. Bodner, A. Schnepf, D. Leitner, G. Kammerer, and W. Loiskandl
Institute of Hydraulics and Rural Water Management, Univ. Natural Resour. Appl. Life Sci., BOKU, Wien, Austria
Institute of Agronomy and Plant Breeding, Univ. Natural Resour. Appl. Life Sci., BOKU, Wien, Austria
Institute of Soil Science, Univ. Natural Resour. Appl. Life Sci., BOKU, Wien, Austria
Modeling soil water dynamics requires an accurate description of soil hydraulic properties, i.e. the retention and hydraulic conductivity functions. Generally, these functions are assumed to be unchanged over time in most simulation studies. In this paper, we implemented temporal changes in the soil hydraulic properties in a Richards’ equation simulation of soil water dynamics. Based on ...
A. Haas, M. Scholle, A. Aksel, H.M. Thompson, R.W. Hewson, and P.H. Gaskell
Department of Applied Mechanics and Fluid Dynamics, University of Bayreuth, Bayreuth, Germany
School of Mechanical Engineering, University of Leeds, Leeds, United Kingdom
Heat transfer in a plane shear flow configuration consisting of two infinitely long parallel plates is considered. In laminar flows over undulated substrates eddies can be generated due to the kinematical constraints. A closed form analytical solution for the velocity field, based on lubrication theory as well as a semi-analytic solution for the temperature field is derived for the creeping flow. ...
Georg-August University, Göttingen, Germany
Viscous fingering is a topic of interest since the beginning of computational fluid dynamics. Here we focus on the classical constellation of miscible displacement, as it has been investigated in Hele-Shaw cells. A temperature or salinity front is entering with a fluid that has a different viscosity. The pure 1D flow is destabilized by the Saffman-Taylor instability. Using COMSOL Multiphysics® ...
Numerical Simulation of the Functional Electromagnetic Stimulation of the Human Femoral Bone using COMSOL
Y. Haba, W. Kröger, H. Ewald, R. Souffrant, W. Mittelmeier, and R. Bader
Biomechanics and Implant Technology Research Laboratory, Department of Orthopaedics, University of Rostock, Rostock, Germany
Institute of General Electrical Engineering, University of Rostock, Rostock, Germany
In the present study we determined the relative conductivities and permittivities of fresh cortical and cancellous bone measuring human femoral heads in different slices of 1 mm thickness. The identified conductivities of human trabecular bone are used for the electromagnetic field simulation by means of COMSOL using a Micro-Computed Tomography (Micro-CT) model. The calculated model depends on a ...