基于宽带天线技术的非接触脑出血监测系统敏感性研究

Sensitivity study of non-contact cerebral hemorrhage monitoring system based on broadband antenna technology

目的:开发一套基于宽带天线技术的非接触脑出血监测系统并测试其敏感性。方法:该系统主要由矢量网络分析仪、贴片天线和脑出血模拟材料组成。设置矢量网络分析仪扫描频率范围300 kHz^3 GHz,以脑出血模拟材料作为被检测对象,以不同出血量(0、1、2、3、4 ml)下的传输参数S21相位差变化量化敏感性的程度,最后利用MATLAB和SPSS 20.0软件对传输参数S21相位差数据进行统计分析。结果:该系统低频段部分相位波动幅度较大,缺乏规律性,中频段及高频段相对较为平稳,随着出血量的增加,系统对出血量变化的敏感性逐渐降低。在频段1.6~1.7 GHz之间存在一个临界频点,致使在出血3 ml后相位差开始降低;在频段1.7~1.8 GHz之间存在一个临界频点,致使在出血2 ml后相位差开始降低。结论:该系统能明显区分脑出血严重程度,敏感性较强,在中频段数据比较有规律,随着出血量的增加,敏感性逐渐减弱。

Objective To develop a non-contact cerebral hemorrhage monitoring system based on broadband antenna technology and test its sensitivity. Methods The system was mainly composed of a vector network analyzer, a patch antenna and brain hemorrhage simulation material. The scanning frequency range of the vector network was 300 kHz-3 GHz. In order to test the sensitivity of the monitoring system, the cerebral hemorrhage simulation material was tested as the object, and the degree of sensitivity was quantified by the phase difference of the transmission parameter S21 under different bleeding volumes(0-4 ml).Finally, the S21 phase difference transmission parameters were calculated and statistically analyzed using MATLAB and SPSS20.0 software. Results The phase fluctuation of the low frequency band of the system was large and lacked regularity. The middle frequency band and the high frequency band were relatively stable. With the increase of the amount of bleeding, the sensitivity of the system to the change of blood volume was gradually reduced. There was a critical frequency between 1.6 and1.7 GHz, so that the phase began to decrease after 3 ml of bleeding;there was a critical frequency between 1.7 and 1.8 GHz, so that the phase value began to decrease after 2 ml of bleeding. Conclusion The system could clearly distinguish the severity of cerebral hemorrhage with strong sensitivity. The data in the middle frequency band is relatively regular. As the amount of bleeding increases, the sensitivity gradually decreases.