摘要
目的 :设计适合非接触磁感应脑阻抗断层成像系统工作的激励源和感应线圈 ,为进一步了解生物组织电阻抗的特性打下良好的基础 .方法 :基于高速电子电路设计技术 ,建立具有差分驱动模式 ,频率 (1MHz～ 2 0MHz)和幅值均线性可调的信号源 ,分析测量结果 ,得出设计参数 .测量并计算感应线圈参数 ,分析影响其特性的因素 结果 :激励源的输出频率在 10MHz时 ,带负载线圈稳定输出最大电压峰峰值 12V ,最大电流2 2 0mA ,频率稳定度为 0 5 % ,输出噪声电压有效值 6 1mV ,信噪比 6 3dB .结论 :本信号源性能满足试验要求 ,受外界电磁辐射干扰影响小 ,感应线圈设计合理 ,有利于进行检测试验 。
AIM: To further explore characteristics of th e impedance of biological tissue and design an appropriate exciting source and i nducing coils for the system of contactless magnetic induction tomography of bra in impedance. METHODS: Based on the principle of the high speed circuits designing, we developed a differential signal source, the freque ncy (between 1 MHz and 10 MHz)and amplitude of which can be linearly justified. Then we discovered the characteristics of the system. Furthermore, parameters of coils were measured and computed. Factors affecting its characteristics were also probed. RESULTS: Specifications of the system at 10 MHz include the constancy of frequency(0 5%), loaded with a coil maxim steady output peak peak voltage(12 V), maxim output current(220 mA), RMS amplitude of no ise(6 1 mV) and signal to noise ratio(63 dB). CONCLUSION: The performance of the system can meet the design requirements protective the system from electromagnetic radiation to a great extent. The inducing coils designed for the system can be also used in detecting experiments. These may be of great help for further imaging work.
出处
《第四军医大学学报》
北大核心
2003年第2期176-178,共3页
Journal of the Fourth Military Medical University
基金
全军医药卫生科研基金课题 (0 1 2 0 78)
关键词
非接触磁感应
脑阻抗断层成像
激励源
设计
contactless magnetic induction
elect rical impedance tomography
coaxial coils
