Marek Paruch

Bio: Marek Paruch is an academic researcher from Silesian University of Technology. The author has contributed to research in topics: Bioheat transfer & Field (physics). The author has an hindex of 9, co-authored 28 publications receiving 269 citations.

The modelling of heating a tissue subjected to external electromagnetic field.

Abstract: The boundary element method (BEM) is used to solve the coupled problem connected with the biological tissue heating. The tissue treated as a non-homogeneous domain (healthy tissue and tumor region) is subjected to external electromagnetic field. The thermal effect is produced by electrodes that touches the skin surface. External electromagnetic field generates the internal temperature field, which can be modelled by using the volumetric internal heat sources in the tissue domain (this source function constitutes one of components of the Pennes equation). In the paper, both BEM application to coupled bioheat transfer problems and numerical results of computations are theoretically considered. The successive examples show the different input data determining the electromagnetic field parameters.

Mathematical Modeling of Breast Tumor Destruction Using Fast Heating during Radiofrequency Ablation.

Abstract: In oncology, hyperthermia is understood as a planned, controlled technique of heating cancerous changes in order to destroy their cells or stop their growth. In clinical practice, hyperthermia is used in combination with radiotherapy, chemotherapy, or immunological therapy. During the hyperthermia, the tissue is typically exposed to a temperature in the range of 40-45 °C, the exception is thermoablation, during which the temperatures reach much higher values. Thermoablation is characterized by the use of high temperatures up to 90 °C. The electrode using the radiofrequency is inserted into the central area of the tumor. Interstitial thermoablation is used to treat, among others, breast and brain cancer. The therapy consists of inducing coagulation necrosis in an area that is heated to very high temperatures. Mathematical modeling is based on the use of a coupled thermo-electric model, in which the electric field is described by means of the Laplace equation, while the temperature field is based on the Pennes equation. Coupling occurs at the level of the additional source function in the Pennes equation. The temperature field obtained in this way makes it possible to calculate the Arrhenius integral as a determinant of the destruction of biological tissue. As a result of numerical calculations regarding the temperature field and the Arrhenius integral, it can be concluded that, with the help of numerical tools and mathematical modeling, one can simulate the process of destroying cancerous tissue.

Identification of electromagnetic field parameters assuring the cancer destruction during hyperthermia treatment

Abstract: Electromagnetic field induced by two external electrodes and temperature field resulting from electrode action in the domain of biological tissue being a composition of healthy region and a tumour is considered. To warrant the optimum conditions of tumour destruction, the magnetic nanoparticles are embedded in this region. It is assumed that the temperature which assures an effect of destruction should be higher than 42°C. In this article, the problems relating to the electrodes’ electric potential identification and the simultaneous identification of potential and number of nanoparticles introduced to the tumour region are discussed. Additional information necessary to solve the task results from the postulated temperature inside the tumour region assuring its destruction. The problem has been solved using both the gradient method and evolutionary algorithm. The boundary element method is applied to solve the coupled problem connected with the heating of biological tissues.

Estimation of relaxation and thermalization times in microscale heat transfer model

Abstract: The energy equation corresponding to the dual phase lag model (DPLM) results from the generalized form of the Fourier law, in which the two `delay times' (relaxation and thermalization time) are introduced. The DPLM should be used in the case of microscale heat transfer analysis, in particular when thermal processes are characterized by extremely short duration (e.g. ultrafast laser pulse), considerable temperature gradients and very small dimensions (e.g. thin metal film). In this paper, the problem of relaxation and thermalization time identification is discussed, at the same time the heat transfer processes proceeding in the domain of a thin metal film subjected to a laser beam are analyzed. The solution presented bases on the application of evolutionary algorithms. The additional information concerning the transient temperature distribution on a metal film surface is assumed to be known. At the stage of numerical realization, the finite difference method (FDM) is used. In the final part of the paper, an example of computations is presented.

The role of tear physiology in ocular surface temperature

Abstract: PURPOSE: To determine whether the more rapid cooling of the tear film in dry eyes is related to other tear film parameters, a battery of tear physiology tests was performed on dry eye patients and control subjects. METHODS: Tear evaporation rate was measured with a modified Servomed (vapour pressure) evaporimeter and ocular temperature with an NEC San-ei 6T62 Thermo Tracer in 9 patients diagnosed as having dry eye and in 13 healthy control subjects. Variability in temperature across the ocular surface was described by the temperature variation factor (TVF). Lipid layer structure and tear film stability were assessed with the Keeler Tearscope and tear osmolality was measured by freezing point depression nanolitre osmometry. RESULTS: The data were explored by principal component analysis. The subjects with and without dry eye could be separated into two distinct groups entirely on the basis of their tear physiology. Dry eye patients exhibited higher tear evaporation rates, osmolalities and TVF, lower tear film stabilities and poorer-quality lipid layers than the control subjects. A significant linear relationship was found to exist between tear evaporation rate and TVF for all subjects (R2 = 0.242, p = 0.024). CONCLUSIONS: Rapid cooling of the tear film in dry eyes appears to be related to the reduced stability of the tears and the increased rate of evaporation. The higher latent heat of vaporisation, associated with the increased evaporation in dry eyes, may account for the increased rate of cooling of the tear film in this condition.

Entropy Generation on MHD Blood Flow of Nanofluid Due to Peristaltic Waves

Abstract: This present study describes the entropy generation on magnetohydrodynamic (MHD) blood flow of a nanofluid induced by peristaltic waves. The governing equation of continuity, equation of motion, nano-particle and entropy equations are solved by neglecting the inertial forces and taking long wavelength approximation. The resulting highly non-linear coupled partial differential equation has been solved analytically with the help of perturbation method. Mathematical and graphical results of all the physical parameters for velocity, concentration, temperature, and entropy are also presented. Numerical computation has been used to evaluate the expression for the pressure rise and friction forces. Currently, magnetohydrodynamics is applicable in pumping the fluids for pulsating and non-pulsating continuous flows in different microchannel designs and it also very helpful to control the flow.

Modeling Heat Transfer in Tumors: A Review of Thermal Therapies

Abstract: It is quite challenging to describe heat transfer phenomena in living systems because of the involved phenomena complexity. Indeed, thermal conduction and convection in tissues, blood perfusion, heat generation due to metabolism, complex vascular structure, changing of tissue properties depending on various conditions, are some of the features that make hard to obtain an accurate knowledge of heat transfer in living systems for all the clinical situations. This theme has a key role to predict accurately the temperature distribution in tissues, especially during biomedical applications, such as hyperthermia treatment of cancer, in which tumoral cells have to be destroyed and at the same time the surrounding healthy tissue has to be preserved. Moreover, the lack of experimentation in this field, due to ethical reasons, makes bioheat models even more significant. The first simple bioheat model was developed in 1948 by Pennes (J Appl Physiol 1:93-122, 1948) but it has some shortcomings that make the equation not so accurate. For this reason, over the years it has been modified and more complex models have been developed. The purpose of this review is to give a clear overview of how the bioheat models have been modified when applied in various hyperthermia treatments of cancer.