# Low-Frequency Magnetic Field Exposure System for Cells Electromagnetic Biocompatibility Studies
## 6 Results and Discussion  
The exposure system allows exposure to homogeneous LF MF of 10 samples, of which five control/shielded and five are exposed, with yeast Saccharomyces cerevisiae simultaneously, while maintaining the same temperature conditions for both groups--exposure and control one has been developed. The exposure system is designed using numerical simulations. The key parameters are measured using constructed facility to confirm the design. The magnetic flux density field, electric field, and total current density field distributions are characterized along with the magnetic flux density field homogeneity and overall exposure uncertainty. The applied B-field uniformity of three middle samples in the exposure coil is better than 99.16%, and the maximum magnetic flux density in the control coil does not exceed 18.47 \(\mu\)T (0.75% of the maximum value of magnetic flux density in the exposure coil). The level of homogeneity of the three middle samples can be considered outstanding [43, 44], and the homogeneity of samples A and E is satisfactory [45]. As for the value of the magnetic flux density field, these results cannot be confronted with the available data because other authors do not state its value; it has not been measured. The situation for the control samples is generally described as the control samples are not exposed to the field or the control samples are shielded. The impact of the switched-off apparatus was not considered [46, 47, 48]. To the shading of the B-field generated by the exposure system theoretically to zero, it would be necessary to use high-quality shading, \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Experiment Number** & **E** & **D** & **C** & **B** & **A** \\ \hline
**1.** & 0.57 & 1.16 & 1.23 & 0.65 & 1.02 \\
**2.** & 0.66 & 1.44 & 1.43 & 1.46 & 1.82 \\
**3.** & 0.80 & 1.01 & 0.82 & 1.13 & 0.98 \\
**4.** & 0.61 & 0.62 & 0.44 & 1.47 & 0.64 \\
**5.** & 0.96 & 1.30 & 1.54 & 1.40 & 0.96 \\
**6.** & 1.20 & 0.85 & 0.88 & 0.52 & 1.60 \\
**7.** & 1.74 & 1.47 & 1.19 & 1.47 & 1.65 \\
**8.** & 1.14 & 1.02 & 1.09 & 0.51 & 0.89 \\
**9.** & 1.01 & 0.94 & 1.24 & 0.80 & 0.52 \\
**10.** & 0.83 & 1.57 & 0.58 & 1.49 & 0.90 \\
**11.** & 0.72 & 1.07 & 0.94 & 1.81 & 0.88 \\
**12.** & 1.86 & 1.09 & 1.17 & 1.53 & 1.66 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: The results of the experiments with respect to the parameter X. e.g., MuMetal. However, it would result in the shading of the terrestrial field. This state is not desirable because it does not represent natural conditions. The natural external EMF, such as the terrestrial E-field and B-field, or the atmospheric EMF--Schumann resonances are vital/necessary for any cell's, microorganism's, animal's, and human's physiological functioning [49]. The functionality of the developed exposure system is tested and confirmed during the 12 experiments, each lasting eight hours. The coil current and temperature in the cavities are continuously monitored during the experiments. The experiments are based on the IPR theory. The effect of applied MF is determined based on the number of cells, as explained in the previous section. Cell numbers are determined by direct counting in a hemocytometer, the Burker chamber. Results of these experiments have shown significant differences between the control and exposed group of samples, Table 3. Mild inhibition and excitation effects of the applied MF are observed. Other groups reported an inhibitory effect on the growth of yeast cells [45, 50], no effect [51], or both effects depending on B-field magnitude [52]. The questions of how the MF affects the yeasts or cells in general, what frequencies, B-field magnitudes, or their combinations are responsible for inhibition, or acceleration growth are far from answered. This area needs systematic, wide, and in-depth research as well. To increase the validity of experiments performed using this exposure system, it is desirable to use several evaluation methods for cell culture growth [46].