Numerical and experimental dosimetry of petri dish exposure setups

Burkhardt, Michael; Pokovic, K.; Gnos, Marcel; Schmid, Thomas; Kuster, Niels

doi:10.1002/(sici)1521-186x(1996)17:6<483::aid-bem8>3.0.co;2-#

Cited by 73 publications

(22 citation statements)

References 9 publications

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“…A large number of studies considering the biological and biomedical effects of High Frequency ElectroMagnetic Fields (HF EMF) were carried out starting from test facilities allowing the generation of an electromagnetic plane wave [1]. Review on exposure systems used for bioelectromagnetic experiments in high frequency range [2] enabled to arrange variety of electromagnetic devices according to their major characteristics.…”

Section: Exposure Setups For Bioelectromagnetic Experiments In High Fmentioning

confidence: 86%

Mode Stirred Reverberation Chamber (Msrc): A Large and Efficient Tool to Lead High Frequency Bioelectromagnetic in Vitro Experimentation

Lalléchère¹,

Girard²,

Roux³

et al. 2010

PIER B

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Abstract-An important aspect of the studies undertaken in bioelectromagnetism relates to the choice of exposure facility. The characteristics of a real electromagnetic environment are far more complex compared to the one plane wave irradiation set-up used in the majority of bioelectromagnetic studies. Moreover, biological requirements should represent the starting point in the design of an in vitro exposure system. Indeed it is important to avoid altering the electromagnetic properties of the exposure system in the presence of biological equipments. Related to these two essential points, this article contributes to show the advantages of a Mode Stirred Reverberation Chamber (MSRC) to guarantee a controlled electromagnetic environment around biological materials for in vitro experimentation. An example of irradiation of in vitro human skin cells cultures is considered to illustrate this paper. In order to show that the biological conditions and the physical requirements for in vitro experiments are checked, two aspects are described. Firstly we achieved the characterization of the electromagnetic field generated around the biological system (both equipments and cultures). Secondly the analysis of the Specific Absorption Rate (SAR) inside the biological medium was evaluated both numerically and experimentally. Initially, the statistical properties of fields inside the MSRC were checked with or without the biological devices in order to verify their electromagnetic transparency with respect to the reverberating properties of the electromagnetic environment (inside MSRC). We checked the good agreement of the experimental electromagnetic power distribution with the theoretical one.The computation of electromagnetic energy absorbed by biological medium (SAR) was based upon Finite Difference in Time Domain (FDTD) technique. A numerical analogy was achieved between the MSRC behavior and a free-space finite sum of random plane waves. Simulations are able to provide both an estimation of SAR distribution inside each biological culture dish and a computation of the coupling effects between dishes. Relying on the previous conclusions, temperature measurements were led to evaluate the experimental SAR levels and its time variations inside the MSRC. Two high-frequency (900 MHz) environments were considered: A 10 minutes exposure with field amplitude inside the biological incubator of 7.87 V/m and 30 minutes with 41 V/m (SAR ranged from 2.6 mW/kg to 73 mW/kg, mean values). Numerical and experimental results prove the ability of MSRC to provide a large and efficient tool to achieve bioelectromagnetic experiments at high frequencies.

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Section: Exposure Setups For Bioelectromagnetic Experiments In High Fmentioning

confidence: 86%

Mode Stirred Reverberation Chamber (Msrc): A Large and Efficient Tool to Lead High Frequency Bioelectromagnetic in Vitro Experimentation

Lalléchère¹,

Girard²,

Roux³

et al. 2010

PIER B

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“…In any case of the Petri dish orientations and the cell formations, the efficiency of the propagating wave exposure is much lower than the standing wave exposure as the above selected one, whereas the exposure heterogeneity of the propagating wave is significantly higher. The power absorption is described as the inductive coupling between the H field and the cell culture, as well as the capacitive coupling between the E field and the cell culture [28]. In this study, the selected arrangement has the maximum H field and the minimum E field in the exposure area.…”

Section: Comparison Between the Standing Wave Exposure And The Propagmentioning

confidence: 99%

DOSIMETRY AND TEMPERATURE EVALUATIONS OF A 1800 MHz TEM CELL FOR IN VITRO EXPOSURE WITH STANDING WAVES

Zhao¹,

Lü²,

Deng³

2012

PIER

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Abstract-A 1800 MHz transverse electromagnetic wave (TEM) cell is introduced for experiments investigating effects on biological samples caused by the exposure from mobile communications. To characterize and quantify the exposure environment in the setup for standardized in vitro experiments, we evaluate the dosimetry and the exposureinduced temperature rise in cultured cells. The study is numerically based on the finite-difference time-domain (FDTD) formulation of the Maxwell equations and the finite-difference formulation of the bioheat transfer equation, with all algorithms and models strictly validated for accuracy. Two sample formations of cells are considered including the cell layer and the cell suspension cultured in the 35 mm Petri dish. The TEM cell is designed to establish standing waves with the maximum E field and the maximum H field, respectively, at the position of the Petri dish. The Petri dish is oriented to E, −E, H, k, and −k directions of the incident field, respectively, to receive the exposure. The specific absorption rate (SAR) is calculated in cells for 10 exposure arrangements combined from the maximum fields and Petri dish orientations. A comparison determines the best arrangement with the highest exposure efficiency and the lowest exposure heterogeneity. The dosimetry and the exposure-induced temperature rise in cells are evaluated for the selected arrangement. To avoid thermal reactions caused by overheating, the maximum temperature rises in cells are recorded during the exposure. Based on the records, the temperature control is performed by setting limits to the exposure duration. We introduce a method to further reduce the exposure heterogeneity and evaluate the influence of the Petri dish holder on the dosimetry and temperature rise. The study compares the TEM cell to the waveguide, as well as the standing wave exposure 488Zhao, Lu, and Deng to the propagating wave exposure. The TEM cell and the selected arrangement of the standing wave exposure improve the exposure quality over the traditional methods, with increased efficiency and decreased heterogeneity of the exposure.

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“…Moreover, it should provide an error estimation in order to minimize uncertainty and guarantee the correctness of the solution for each model. Several numerical methods have been employed for Petri dish simulations exposed to EM fields in different configurations, e.g., [3,20,21,16,1,22,23]. Approaches based on differential formulations are mainly used because of their flexibility to deal with complex geometrical and material configurations.…”

Section: Introductionmentioning

confidence: 99%

High-accuracy adaptive modeling of the energy distribution of a meniscus-shaped cell culture in a Petri dish

Gomez-Revuelto

Garcı́a-Castillo

Pardo

2015

Journal of Computational Science

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Cylindrical Petri dishes embedded in a rectangular waveguide and exposed to a polarized electromagnetic wave are often used to grow cell cultures. To guarantee the success of these cultures, it is necessary to enforce that the specific absorption rate distribution is sufficiently high and uniform over the Petri dish. Accurate numerical simulations are needed to design such systems. These simulations constitute a challenge due to the strong discontinuity of electromagnetic material properties involved, the relative low field value within the dish cultures compared with the rest of the domain, and the presence of the meniscus shape developed at the liquid boundary. The latter greatly increases the level of complexity of the model in terms of geometry and intensity of the gradients/singularities of the field solution. In here, we employ a three-dimensional (3D) hp-adaptive finite element method using isoparametric elements to obtain highly accurate simulations. We analyze the impact of the geometrical modeling of the meniscus shape cell culture in the hp-adaptivity. Numerical results showing the error convergence history indicate the numerical difficulties arisen due to the presence of a meniscus-shaped object. At the same time, the resulting energy distribution shows that to consider such meniscus shape is essential to guarantee the success of the cell culture from the biological point of view.

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Numerical and experimental dosimetry of petri dish exposure setups

Cited by 73 publications

References 9 publications

Mode Stirred Reverberation Chamber (Msrc): A Large and Efficient Tool to Lead High Frequency Bioelectromagnetic in Vitro Experimentation

Mode Stirred Reverberation Chamber (Msrc): A Large and Efficient Tool to Lead High Frequency Bioelectromagnetic in Vitro Experimentation

DOSIMETRY AND TEMPERATURE EVALUATIONS OF A 1800 MHz TEM CELL FOR IN VITRO EXPOSURE WITH STANDING WAVES

High-accuracy adaptive modeling of the energy distribution of a meniscus-shaped cell culture in a Petri dish

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