Elisabetta Sieni

Magnetic Field Synthesis in the Design of Inductors for Magnetic Fluid Hyperthermia

A magnetic fluid hyperthermia (MFH) inductor design using multiobjective evolution strategy techniques is proposed. Uniformity of the magnetic field and solution sensitivity are the objective functions chosen for the selection of the inductor geometry. After a 3-D finite-element analysis (FEA) of the thermal field, the coupled-field response of the synthesized inductor has been assessed.

Coupled field synthesis in Magnetic Fluid Hyperthermia

In this paper, the actual synthesis of the thermal field is proposed and solved as an inverse problem, considering a fully coupled magnetic-thermal analysis as for the direct problem. Reference is made to an air-cored inductor for magnetic fluid hyperthermia (MFH).

Synthesizing Distributions of Magnetic Nanoparticles for Clinical Hyperthermia

An automated procedure based on evolutionary computation and Finite Element Analysis (FEA) is proposed to synthesize the optimal distribution of nanoparticles (NPs) in multi-site injection for a Magnetic Fluid Hyperthermia (MFH) therapy. In particular a bi-objective formulation of the synthesis problem is considered taking into account both surface and volume temperature distribution in the tumor region.

A Paretian Approach to Optimal Design With Uncertainties: Application in Induction Heating

A major issue in optimal design of electromagnetic devices relates to optimizing against uncertainty, in terms of geometric and physical parameters. The induction heating of a graphite disk, with the purpose to obtain a prescribed temperature profile, is considered as the model problem. The novelty of this paper is a cost-effective method enabling the designer to select the Pareto optimal solutions trading off design criterion and sensitivity.

Evaluation of the Electroporation Efficiency of a Grid Electrode for Electrochemotherapy: From Numerical Model to In Vitro Tests.

Electrochemotherapy (ECT) is a local anticancer treatment based on the combination of chemotherapy and short, tumor-permeabilizing, voltage pulses delivered using needle electrodes or plate electrodes. The application of ECT to large skin surface tumors is time consuming due to technical limitations of currently available voltage applicators. The availability of large pulse applicators with few and more spaced needle electrodes could be useful in the clinic, since they could allow managing large and spread tumors while limiting the duration and the invasiveness of the procedure. In this article, a grid electrode with 2-cm spaced needles has been studied by means of numerical models. The electroporation efficiency has been assessed on human osteosarcoma cell line MG63 cultured in monolayer. The computational results show the distribution of the electric field in a model of the treated tissue. These results are helpful to evaluate the effect of the needle distance on the electric field distribution. Furthermore, the in vitro tests showed that the grid electrode proposed is suitable to electropore, by a single application, a cell culture covering an area of 55 cm2. In conclusion, our data might represent substantial improvement in ECT in order to achieve a more homogeneous and time-saving treatment, with benefits for patients with cancer.

Optimal inductor design for nanofluid heating characterisation

Purpose – Magnetic fluid hyperthermia experiment requires a uniform magnetic field in order to control the heating rate of a magnetic nanoparticle fluid for laboratory tests. The automated optimal design of a real-life device able to generate a uniform magnetic field suitable to heat cells in a Petri dish is presented. The paper aims to discuss these issues. Design/methodology/approach – The inductor for tests has been designed using finite element analysis and evolutionary computing coupled to design of experiments technique in order to take into account sensitivity of solutions. Findings – The geometry of the inductor has been designed and a laboratory prototype has been built. Results of preliminary tests, using a previously synthesized and characterized magneto fluid, are presented. Originality/value – Design of experiment approach combined with evolutionary computing has been used to compute the solution sensitivity and approximate a 3D Pareto front. The designed inductor has been tested in an experi...

A Translational Coupled Electromagnetic and Thermal Innovative Model for Induction Welding of Tubes

In the paper, a novel approach to numerical modeling of tube induction welding is proposed. The coupled electromagnetic and thermal model must take into account also the movement of the metal strip: in order to make possible this kind of simulation in reasonable computation time, a simplified approach to the modeling is presented and discussed.

Multi–objective optimisation of induction heating processes: methods of the problem solution and examples based on benchmark model

The main goal of the researches is the development of new approaches, algorithms and numerical techniques for multi–objective optimisation of design of industrial induction heating installations. A multi–objective optimisation problem is mathematically formulated in terms of the typical optimisation criteria, e.g., maximum heating accuracy and minimum energy consumption. Various mathematical methods and algorithms for multi–objective optimisation, such as Non–dominated Sorting Genetic Algorithm (NSGA–II) and optimal control alternance method, have been implemented and integrated in a user–friendly automated optimal design package. Several optimisation procedures have been tested and investigated for a problem–oriented mathematical model in a number of comparative case studies. A general comparison of the design solutions based on NSGA–II and alternance method leads to their good agreement in all investigated cases. The methodology developed is planned to be applied to more complex real–life problems of the optimal design and control of different induction heating systems.

Optimal Needle Positioning for Electrochemotherapy: A Constrained Multiobjective Strategy

A multiobjective optimization method is used to design a treatment planning based on electrochemotherapy (ECT). A penalty function technique is coupled to NSGA algorithm in order to identify the constrained Pareto front, so preventing unfeasible solutions.

Multi-objective design of a power inductor: a benchmark problem of inverse induction heating

Purpose – The purpose of this paper is to investigate a bi-objective optimization problem characterized by coupled field analysis. The optimal design of a pancake inductor for the controlled heating of a graphite disk is considered as the benchmark problem. The case study is related to the design of industrial applications of the induction heating of graphite disk. Design/methodology/approach – The expected goal of the optimization process is twofold: to improve temperature uniformity in the disk and also electrical efficiency of the inductor. The solution of the relevant bi-objective optimization problem is based on multiphysics field analysis. Specifically, the direct problem is solved as a magnetic and thermal coupled problem by means of finite elements; a mesh-inspired definition of thermal uniformity is proposed. In turn, the Pareto front trading off electrical efficiency and thermal uniformity is identified exploiting evolutionary computing. Findings – By varying the problem targets, different Paret...