SAR Analysis for handheld mobile phone using DICOM based voxel model

Abstract

In this paper, Specific Absorption Rates (SAR) inside the human head and hand have been analyzed for a handheld mobile phone operated at GSM 900 band. Both the head and hand are modeled electrically using Digital Imaging and Communication in Medicine (DICOM) formatted CT Scan voxel data considering the electrical parameters of different internal anatomical structures. Three-dimensional Finite Difference in Time Domain (FDTD) method has been used to simulate SAR induced in the head and hand. Maximum peak 1-g and 10-g SARs of 1.33 W/kg and 0.388 W/kg are found at antenna resonance frequency of 930 MHz for 0.6 W applied input power which are below the limits set by ANSI/IEEE and FCC, respectively. Index Terms-FDTD, near-field, peak 1-g and 10-g SARs, DICOM data, CT scan, human head and hand models.

Fields and coupling between coils embedded in conductive environments

“…Once the conductivity grows sufficiently large, the upper and lower media become more impermeable and progressively their contribution to the total magnetic field in the vicinity of the receiver declines. The new analytical solution then coincides with the original D&D. However, the range of conductivity of media from 0 to 10 S/m is critical for MI communication applications because the conductivities of human tissues and organs, water, sea water and most soil types fall in that range [8,9].…”

“…Also, since the MI waveguides are constructed from isolated discrete resonators, they can be quite flexible and resilient compared to a continuous traditional waveguide. While most materials in nature are nonmagnetic, they are often conductive [8,9], resulting in an attenuation of the near fields which enable the coupling between resonators. When an MI waveguide is embedded in a conductive medium, eddy currents generated by the coupling magnetic flux are, in general, expected to lower the inter-element coupling strength, which will in turn reduce the MI waveguide bandwidth and increase their attenuation.…”

“…Apart from wireless underground/underwater communications networks (WUCNs), the study of coupled resonant coils immersed in a dissipative medium is of great interest in embedded biomedical systems and in body area networks for health-related applications, since the human body and other biological tissues are moderately conductive at microwave frequencies within the range of conductivity from about 0.05 S/m (fat) to about 1.5 S/m (blood) [9].…”

Offline RF thermal ablation planning using CT/MRI scan data

“…These models were represented by equations of planes, spheres, cones, ellipsoids, elliptical cylinders or cylinders and do not conform to the shape of real anatomical organs. To obtain more accurate result, free and non-free voxel-based computational models constructed from CT/MR/ultrasound scan data came in the research domain (21)(22)(23)(24)(25)(26)(27). However these models are not suitable for subject specific investigations.…”

“…The header contains a Service-Object Pair (SOP) instance related to Information Object Definition (IOD) (29) which is useful for voxelization of scanned organ. The voxel-based tomographic computational model can be constructed by stacking up the medical images embedded within the DICOM files (23). In this study, the required computational electrical model has been constructed from PET-CT image data set available in DICOM format.…”