The Simulation Research Of The Infection Of The Medical Antennas Electromagnetic Radiation On The Human Head

With the rapid development of science and technology and the improvement of human life,people pay more attention to medical treatment and health.The equipment of Medical diagnosis and treatment has been renovated and a variety of wireless medical devices and wearable devices quickly access into small and big hospitals,rehabilitation centers,nursing homes and families.At the same time of providing convenience for monitoring health and rehabilitation treatment,the electromagnetic radiation from them is also not allow to ignore.So the study of medical antenna radiation problem has important theoretical and practical significance.In this paper,Finite Difference Time Domain Method and Finite Element Method are using to calculate the electromagnetic field and combining their applying in the biological electromagnetism,two human head electromagnetic model which is suitable for different simulation software are constructed.The electromagnetic model of the human head which has the same shape with SAM model is established based on software COMSOL and the other is suitable for XFDTD and constructed by Photoshop and MRI.In this paper,two medical antenna are designed.One is a microstrip patch antenna which has GSM900/1800 frequency band and the other is Yagi antenna whose working central frequency is 2.26GHz and S11 parameter is-16.95dB.Combining with medical microstrip patch antenna and SAM brain electromagnetic model,COMSOL simulation model is constructed.By using COMSOL software,the distribution of SAR and temperature change of people's head in near field intensity is calculated when the medical antenna in different circumstances.It is verified that the effect of electromagnetic radiation to human body is related to the transmitting frequency,the distance as well as the size of the radiation source.Using the software XFDTD,the radiation influence for the human head from Yagi antenna is simulated and different SAR distribution in different tissue are obtained.For the surface skin of the human head and some tissues with lots of water,the SAR distribution is higher.Because they have strong absorbing properties for electromagnetic waves.Compared with the Chinese and international criterions,the results of SAR values are little than the radiation hygiene standards when the antenna is placed in the current mode.Finally,the influence of human body model for the antenna radiation characteristics and the existence of the human head model changes the antenna's radiation direction are discussed.