Energy Deposition in a Model of Man: Frequency Effects
Energy Deposition in a Model of Man: Frequency Effects
复制标题
人体模型中的能量沉积：频率效应
DOI：
10.1109/tbme.1986.325761
复制
发表时间：
1986
影响因子：
4.6
通讯作者：
G. Hartsgrove
中科院分区：
文献类型：
--
作者：
S. Stuchly;M. Stuchly;A. Kraszewski;G. Hartsgrove
一个计算机控制的扫描系统和植入式，非扰动电场探头被用来测量在一个全尺寸均匀的人体模型的电场的空间分布。测量在三个频率（160，350和915 MHz）在远场和近场的谐振偶极子。的特定吸收率（SAR）的分布和身体部位和全身的平均值作为频率的函数进行了分析。在远场中，SAR在所有频率下沿躯干中的波传播方向呈指数下降，并且沿身体主轴沿着观察到SAR的大梯度，特别是对于E极化。在160和350 MHz处，颈部产生高局部SAR。对于平面波照射，峰值SAR与全身平均SAR的比值似乎不超过20。在近场中，也产生大的SAR梯度，并且取决于频率和极化，峰值空间SAR与全身平均SAR的比率从大约30变化到250。建议对于近场照射，全身平均SAR不是适当的剂量测量方法，建议采用任何0.1组织体积的平均SAR。
A computer-controlled scanning system and implantable, nonperturbing electric field probes were used to measure spatial distributions of the electric field in a full scale homogeneous model of a human body. The measurements were performed at three frequencies (160, 350, and 915 MHz) in the far-field and in the near-field of resonant dipoles. The specific absorption rate (SAR) distributions and the averages for body parts and the whole body are analyzed as functions of frequency. In the far-field, the SAR decreases exponentially in the direction of wave propagation in the torso at all frequencies, and large gradients of the SAR are observed along the body main axis, particularly for the E polarization. At 160 and 350 MHz high local SAR's are produced in the neck. It appears that for plane wave exposures the ratio of the peak SAR to the whole-body average SAR does not exceed 20. In the near-field, large SAR gradients are also produced, and the ratios of the peak spatial SAR to the whole-body average SAR vary from about 30 to 250 depending on the frequency and polarization. It is suggested that for near-field exposures the whole-body average SAR is not a proper dosimetric measure, and the SAR averaged over any 0.1 of the tissue volume is recommended instead.