基于磁纳米测温的弱磁信号检测系统

Weak Magnetic Signal Detection System Based on Magnetic Nanometer Temperature Measurement

肿瘤热疗是一种癌症治疗的新型手段,近年来,利用磁纳米粒子进行温度测量成为研究热点,利用其磁化信号可实现非侵入式温度测量.本系统由磁场探测装置、信号放大电路、数据采集系统和软件处理系统等4部分构成.首先,在研究分析的基础上,选用感应线圈式磁场探测装置,并在此基础上构建了等效电路模型,同时辅以差分线圈以剔除激励磁场信号的影响;其次通过对信号放大电路的仿真结果分析,发现采用级联的方式可以降低总噪声;然后用数据采集卡采集放大后的信号并通过数字相敏检波算法提取幅值;最后通过在Lab VIEW平台开发的软件从软件层面进一步消除激励信号的影响,通过对实验数据的分析,很好的证明了系统的可靠性.

Hyperthermia is a new means for treating cancer,the method of temperature measurement based on magnetic nanoparticles has been a research hot spot in recent years.The temperature is measured using magnetic susceptibility of magnetic nanoparticles.The system is composed of four parts, namely, magnetic field detection device,signal amplification circuit,data acquisition system and software processing system.In this paper, the induction coil is used to detect the magnetic field, the equivalent circuit of the induction coil is constituted, and a differential coils is used to eliminate the residual magnetic field. By analyzing the simulation results of the signal amplification circuit, it is found that the cascade method can reduce the to-tal noise.The signal is sampled by data acquisition card （PXIe-6368） , extracted by digital phase-sensi-tive detection algorithms.The interference of residual magnetic field is eliminated in soft system, which is developed based on LabVIEW environment.The system is well validated through experimental data.