Simulation analysis of coupled magnetic-temperature fields in magnetic fluid hyperthermia

Abstract

Magnetic fluid hyperthermia (MFH) adopts the relaxation mechanism of magnetic nanoparticles to heat targeted tumors by coupling magnetic fields and temperature fields. Temperature regulation plays an important role in determining hyperthermia efficacy. It is generally difficult to obtain the distribution of temperature over the whole treatment region during clinical hyperthermia due to the limitations of invasive temperature measurements. To predict the temperature and its distribution during hyperthermia, this paper uses the finite element method and builds a coupled multiphysics model of MFH to analyze the magnetic field and temperature distributions within treated tissue and to determine the influence of the magnetic field strength on the tissue temperature during hyperthermia. The heat dissipation equations are used as inputs to determine the specific loss power of heat sources for nanoparticle injection sites. The results show the distribution of the temperature in the targeted tissue. In addition, an in vitro MFH experiment is subsequently performed with cervical cancer cell cultures. A temperature increase of approximately 4 °C is observed in the tumor tissue treated with Fe2O3 magnetic fluids when the magnetic field is applied for 30 minutes. Hence, the feasibility of hyperthermia and the accuracy of the proposed simulation model are verified with such experimental results.

Development of a Magnetic Fluid Heating FEM Simulation Model with Coupled Steady State Magnetic and Transient Thermal Calculation

“…Although this was the case, the initial slope of both should be comparable and, with it, comparable SAR. The temperature dependency on time, presented in Figures 13-15, shows a similar dependency as shown in other works, like in the literature [10,16].…”

“…For the obtained curves, Specific Loss Power (SLP) was determined and used for numerical modelling of the system. Many articles deal with numerical simulations calculating the heating of MNPs in cancer tissue using a heating model based on relaxation processes and Pennes bioheat equation [11][12][13][14][15][16]. Similarly, [17] deals with the numerical modelling of hypethermia using the Pennes model for heat transfer while using the Gaussian heat generation distribution proposed by [18].…”

“…In the literature, mathematical models used to calculate the heating of the magnetic fluid are known. They are used to simulate heating of the MNPs in cancer tissue in [11][12][13][14][15][16]. For the laboratory setting, simulations in the literature use pre-measured heating results for heating power data, and simulate temperature distribution using the transient thermal calculations in [9,10], although to our knowledge, coupled magnetic and thermal simulations for the laboratory setting are missing.…”

Core Stress Analysis of Amorphous Alloy Transformer for Rail Transit under Different Working Conditions

“…The research object of this paper is the SBH15-M 10 kV oil-immersed amorphous alloy transformer [8,9,17], as this type is the most commonly used in China, and its outline diagram is shown in Figure 3. The rated capacity is 315 kVA, the rated voltage of highvoltage winding is 10 kV, and the rated voltage of low-voltage winding is 0.4 kV.…”

“…In this paper, the finite element analysis method is used to study stress conditions of amorphous alloy transformer cores under different working conditions. The finite element method [17] is an effective method to analyze the electromagnetic characteristics of amorphous alloy transformers. Bahmani [18] used the equivalent elliptic loop (EEL) method in Ansoft Maxwell 3D (Ansoft Corp., Pittsburgh, USA) to calculate the core losses of high-frequency high-power transformers and compared them with the empirical equations, verifying the practicability of the finite element method in electromagnetic field analysis.…”