Biomedical subjects

R De Leo

Publications and source records attributed to R De Leo.

21 records · Page 2Linked to original sources

PubMed1986

Absorbed power distributions from single or multiple waveguide applicators during microwave hyperthermia.

A theoretical model has been developed to calculate the power distributions in biological-like tissues in direct contact with waveguide applicators. A numerical solution of the coupled integral equations is performed by means of their transformation into matrix equations by using the method of moments, where the biological tissue and the applicator are described by two independent matrices. The model permits an accurate evaluation of the electric field at the aperture. The application of this method for the evaluation of arrays is also discussed. Power contour plots produced by applicators routinely used in clinics have been computed and compared with experimental results obtained with tissue-equivalent phantoms for three typical bodies: homogeneous, stratified and inhomogeneous.

Humans↗

PubMedDate not supplied

Computer modelling of brain cortex excitation by magnetic field pulses.

In spite of many clinical and experimental applications, the technique of transcranial magnetic stimulation still presents obscure aspects. This especially concerns safety parameters and the exact characterization of the current induced by a single magnetic pulse. The model proposed consists of an equivalent electric network derived by Maxwell's equations and applied to discretized magnetic resonance imaging of a normal subject. This model allows accurate prediction of current distribution, charge per phase and dissipated energy.

Cerebral Cortex↗

PubMedDate not supplied

An accurate 3-D model for magnetic stimulation of the brain cortex.

We present a 3-D model for the simulation of a realistic clinical situation during magnetic stimulation. The electromagnetic problem is solved by reconstructing the inhomogeneous head tissues from magnetic resonance images and associating relative values of conductivity to each tissue. Application of Maxwell's equations in the integral form leads to an equivalent 3-D electrical network, whose solution gives the current density distribution in the brain. The high spatial resolution and rigorous electromagnetic approach make this model an accurate and useful tool for stimulator design and for estimating the efficiency and safety of this clinical methodology.

Algorithms↗