## 4 Discussion and Conclusions  
From the previous evaluations of the subsection, we believe that significant deviations between experimental measurements and simulations are caused by the following factors:  
Most simulated models include more detailed representations of human tissues, including bones, muscles, and internal organs, which affect EMF interaction and the resulting E values. In contrast, the phantom used in the experiments has a less complex structure, leading to smaller differences in the E values. The bones included in the simulation models can be a significant factor influencing the distribution of EMF in the human body. Part of the radiation can be reflected from the bones, which leads to the formation of a local maximum on the body surface. The near field of EM radiation at very short distances (up to a few millimetres) is complex and unpredictable. The relationships used to convert power levels (E values) are primarily intended for the far field, which could cause inaccuracies at distances as small as 5 mm. The size of the deviations decreased at larger distances (15 mm, 50 mm, and 300 mm), where they were significantly smaller between measurements and simulations. To reduce the computational and time requirements, the simulations used a simplified, hollow model of the pacemaker. However, the real experiments used a fully functional pacemaker with all the complex components such as batteries, electronic circuits, and sensors. We think that the difference in complexity and material composition could have also affected the resulting values  
The following graphical representation (Figure 12) provides a detailed analysis and comparison of the results obtained from simulations and experimental measurements for situations where a PM was implanted and for situations without a pacemaker. The graph clearly shows the differences in E between individual models and scenarios. When comparing individual scenarios of simulations and measurements, we found that the average increase in E values in simulations with an implanted device for different distances was as follows: at a distance of 5 mm by 23.47%, at a distance of 15 mm by 37.14%, and at a distance of 50 mm by 62.36%. It is obvious that at larger distances (e.g., 50 mm) the EMF is less concentrated and more scattered. A pacemaker, as a complex object with different materials and components, could thus significantly affect the distribution of the field. This effect is likely to be more pronounced at longer distances, where various interactions, reflections, scatterings, or absorptions can occur. One of the factors that influences the results is tissue heterogeneity, since EMF can propagate through different tissues with different electrical properties. These tissues combined with the implant would thus create a complex system where each element could contribute to the overall field intensity. A distance of 50 mm could represent a sufficient space where these interactions would be more pronounced. Expert sources such as the European Society of Cardiology [31] stress that it is safe to maintain this distance when using mobile phones and also recommend using the phone on the ear opposite to where the pacemaker is implanted. Based on our simulations and experimental measurements, we found that maintaining a minimum distance of 15 cm between the mobile phone and the pacemaker is not sufficient to ensure patient safety. Our results show that even at a distance of 30 cm, the E values for the models were: MM--54.96 V/m, for Child--65.34 V/m, for Laura--62.81 V/m, and measurements--52.72 In M. In the case of the Child and Laura complex models, the E values still exceeded the exposure limit of 58 V/m for a frequency of 1800 MHz. Our recommendation is to push this limit up to more than 30 cm. Another recommendation is protective equipment that reduces the exposure of parts of the human body to EMF. However, these aids must have a certificate of satisfactory EM compatibility. Conceptualization, F.B. and M.B. ; methodology, F.B., M.B., Z.P., M.S., M.P. and J.O.