The system analysis of specific absorption rate(SAR)in human body exposed to a base station antenna by using finite difference time domain techniques was presented in this research works.The objectives of ...The system analysis of specific absorption rate(SAR)in human body exposed to a base station antenna by using finite difference time domain techniques was presented in this research works.The objectives of this work are to evaluate the knowledge and awareness about SAR among human body and mobile base station.The paper investigates the electromagnetic wave absorption inside a human body.The human body has been identified using dataset based on 2D object considering different electrical parameters.The SAR convinced inside the human body model exposed to a radiating base station antenna(BSA)has been considered for multiple numbers of carrier frequencies and input power of 20 W/carrier at GSM 900 band.The distance(R)of human body from BSA is varied in the range of 0.1 m to 5.0 m.For the number of carrier frequency equal to one and R=0.1 m,the concentrated value of whole-body average SAR obtained by FDTD technique is found to be 0.68 W/kg which decreases either with increase of R or decrease of number of carrier frequencies.Safety distance for general public is found to be 1.5 m for number of carrier frequencies equal to one.The performance accuracy of this analysis meets the high level condition by comparing with the relevant system development in recent time.展开更多
目的通过对SAR影响参数研究,计算10秒SAR,指导MR扫描顺利进行。方法采用GE公司HD3T扫描仪,头颅8通道线圈,扫描序列为T2-FSE,改变体重、TR、层数等参数对水模进行扫描,观察SAR的改变。结果SAR与体重和TR有关,而与扫描的层数无关,SAR是RF...目的通过对SAR影响参数研究,计算10秒SAR,指导MR扫描顺利进行。方法采用GE公司HD3T扫描仪,头颅8通道线圈,扫描序列为T2-FSE,改变体重、TR、层数等参数对水模进行扫描,观察SAR的改变。结果SAR与体重和TR有关,而与扫描的层数无关,SAR是RF、B0、体重和TR的函数。根据体重与10秒SAR的关系曲线,通过MATLAB,进行一个曲线拟合,得出10 s SAR与体重的关系方程式:SAR=((-5.96E-09)X4-(2.08E-06)X3+0.0005681X2-0.04531X+1.638)*Peak_SAR.结论SAR是RF脉冲序列、B0、体重和TR的函数,我们所得到的MATLAB4次方程式,只要输入病人体重和Peak_SAR就能直接得到10 s SAR,就可以估计扫描是否暂停,以及暂停时间。展开更多
Objective: To investigate the electromagnetic field and specific absorptionrate (SAR) distribution of different structure applicators with different depths for treating bonetumors using microwave hyperthermia. Methods...Objective: To investigate the electromagnetic field and specific absorptionrate (SAR) distribution of different structure applicators with different depths for treating bonetumors using microwave hyperthermia. Methods: The finite element method (FEM) was used to calculate,electromagnetic field and SAR distribution. Two different structure applicators were simulated. Theone is simple coaxial antenna, which has been successfully used in clinic treating bone tumors inTangdu hospital of the Forth Military Medical University several years. It was formed by a coaxialcable peeled off the out copper at end. The other applicator was coaxial- slot antenna, which waswidely used in microwave hyperthermia. The applicator inserted into the cylindrical bone withdifferent depths, and worked at the frequency of 2 450 MHz. Results: The electric field and SARgenerated by the simple coaxial applicator were mainly concentrated out the tissues, and were notuniform in the tissues, while the coaxial- slot applicator well transmits the electric field and SARinto the tissues, and can easily treat different position by adjusting the slat position.Conclusion: The results calculated by EFM, were well accordant with the experimental and clinicalresulls, and will be important for improving the clinical effects of microwave hyperthermia.展开更多
基金This work is collaborative research with the Department of Electronics&Communication Engineering,Acharya Institute of Technology,Bengaluru,India.And also this work is a collaborative research between Yangon Technological University and University of Oulu in Finland based on the enhancement of Telecommunication Engineering Education in YTU.This work is fully supported by the government research funds of 2020-2021 academic year which is the grant no of GB/D(4)2020/4.
文摘The system analysis of specific absorption rate(SAR)in human body exposed to a base station antenna by using finite difference time domain techniques was presented in this research works.The objectives of this work are to evaluate the knowledge and awareness about SAR among human body and mobile base station.The paper investigates the electromagnetic wave absorption inside a human body.The human body has been identified using dataset based on 2D object considering different electrical parameters.The SAR convinced inside the human body model exposed to a radiating base station antenna(BSA)has been considered for multiple numbers of carrier frequencies and input power of 20 W/carrier at GSM 900 band.The distance(R)of human body from BSA is varied in the range of 0.1 m to 5.0 m.For the number of carrier frequency equal to one and R=0.1 m,the concentrated value of whole-body average SAR obtained by FDTD technique is found to be 0.68 W/kg which decreases either with increase of R or decrease of number of carrier frequencies.Safety distance for general public is found to be 1.5 m for number of carrier frequencies equal to one.The performance accuracy of this analysis meets the high level condition by comparing with the relevant system development in recent time.
文摘目的通过对SAR影响参数研究,计算10秒SAR,指导MR扫描顺利进行。方法采用GE公司HD3T扫描仪,头颅8通道线圈,扫描序列为T2-FSE,改变体重、TR、层数等参数对水模进行扫描,观察SAR的改变。结果SAR与体重和TR有关,而与扫描的层数无关,SAR是RF、B0、体重和TR的函数。根据体重与10秒SAR的关系曲线,通过MATLAB,进行一个曲线拟合,得出10 s SAR与体重的关系方程式:SAR=((-5.96E-09)X4-(2.08E-06)X3+0.0005681X2-0.04531X+1.638)*Peak_SAR.结论SAR是RF脉冲序列、B0、体重和TR的函数,我们所得到的MATLAB4次方程式,只要输入病人体重和Peak_SAR就能直接得到10 s SAR,就可以估计扫描是否暂停,以及暂停时间。
文摘Objective: To investigate the electromagnetic field and specific absorptionrate (SAR) distribution of different structure applicators with different depths for treating bonetumors using microwave hyperthermia. Methods: The finite element method (FEM) was used to calculate,electromagnetic field and SAR distribution. Two different structure applicators were simulated. Theone is simple coaxial antenna, which has been successfully used in clinic treating bone tumors inTangdu hospital of the Forth Military Medical University several years. It was formed by a coaxialcable peeled off the out copper at end. The other applicator was coaxial- slot antenna, which waswidely used in microwave hyperthermia. The applicator inserted into the cylindrical bone withdifferent depths, and worked at the frequency of 2 450 MHz. Results: The electric field and SARgenerated by the simple coaxial applicator were mainly concentrated out the tissues, and were notuniform in the tissues, while the coaxial- slot applicator well transmits the electric field and SARinto the tissues, and can easily treat different position by adjusting the slat position.Conclusion: The results calculated by EFM, were well accordant with the experimental and clinicalresulls, and will be important for improving the clinical effects of microwave hyperthermia.
