RF dosimetry: a comparison between power absorption of female and male numerical models from 0.1 to 4 GHz

Abstract

Realistic numerical models of human subjects and their surrounding environment represent the basic points of radiofrequency (RF) electromagnetic dosimetry. This also involves differentiating the human models in men and women, possibly with different body shapes and postures. In this context, the aims of this paper are, firstly, to propose a female dielectric anatomical model (fDAM) and, secondly, to compare the power absorption distributions of a male and a female model from 0.1 to 4 GHz. For realizing the fDAM, a magnetic resonance imaging tomographer to acquire images and a recent technique which avoids the discrete segmentation of body tissues into different types have been used. Simulations have been performed with the FDTD method by using a novel filtering-based subgridding algorithm. The latter is applied here for the first time to dosimetry, allowing an abrupt mesh refinement by a factor of up to 7. The results show that the whole-body-averaged specific absorption rate (WBA-SAR) of the female model is higher than that of the male counterpart, mainly because of a thicker subcutaneous fat layer. In contrast, the maximum averaged SAR over 1 g (1gA-SAR) and 10 g (10gA-SAR) does not depend on gender, because it occurs in regions where no subcutaneous fat layer is present.

Exposure of Workers to Electromagnetic Fields. A Review of Open Questions on Exposure Assessment Techniques

“…To obtain accurate results on real situations, very high resolution models of the human body should be implemented for different ages, dimensions and phenotypes. For instance, an increase of whole-body SAR up to 25% has been reported for female models (compared to male ones), due to different content and distribution of fat tissue [31]. Such models should be also able to represent typical complex postures; whereas the ones available now represent the posture during MRI or a computed axial tomography (CAT) scan.…”

Infrared thermography based studies on mobile phone induced heating

“…5 and 8 that the magnitudes of temperature rise of the male subjects were comparatively lower than that of the female subjects in both the cases. Using numerical simulations on suitable female and male dielectric anatomic models, Sandrini et al [38] have shown that near head and neck regions, the absorption at 1000 MHz does not substantially differ with gender as variations in sub-cutaneous fat levels are insignificant in these regions. Based on the above finding it can be stated that the variation in the temperature rise in the male and female subjects can be due to variation of specific heat of the tissues as the water content in male tissue is higher compared to that in female tissues (58.3 ± 6.7% in males compared to 48.5 ± 8.6% in females) [39].…”

Specific absorption rates in the human head and shoulder for passive UHF RFID systems

“…This model is very accurate and considerably complete and complex, but has yet to be use for studies pertaining to passive RFID systems in dense environments. Sandrini et al [5] published a method that is resource friendly, which completely ignored the use of voxels. This method disregarded the voxel method and allows for data extraction from grayscales in the MRI data, which provide for semi-automatic generation of the dielectric model [1,5].…”

“…Sandrini et al [5] published a method that is resource friendly, which completely ignored the use of voxels. This method disregarded the voxel method and allows for data extraction from grayscales in the MRI data, which provide for semi-automatic generation of the dielectric model [1,5]. The results of this experiment depicted in Figure 1c show that a dielectric anatomical model can be used to generalize the exposure to RF radiation from the far field [1,5].…”