交流励磁三维定位系统中磁传感器设计

Design of the magnetic sensor in alternating electromagnetic localization system

交流励磁定位系统可以对介入式微型医疗装置在人体内的三维位置实现非接触式遥测。在定位系统中,为了测量磁场分布范围宽、下限磁场微弱的交变磁场,本文设计开发了感应线圈式磁传感器。根据电磁感应原理,感应线圈先将交变的磁信号转换为电信号,再通过后级信号处理电路在强大的噪声背景中提取出有用的电信号,结合传感器的输入输出特性,即获得待测磁场大小。实验结果表明:磁传感器能准确测量微弱交变磁场,且具有宽测量范围、高分辨率、高稳定性和高精度的优点。磁传感器还能适用于一切非导磁环境中跨度大的交变磁场的测量,具有通用性。

Alternating electromagnetic localization system can determine the spatial position and orientation of an implantable medical instrument in human body. In the localization system, in order to measure the magnitude of the alternating electromagnetic field that distributes in wide range and is extremely weak in lower limit, a magnetic sensor was designed. The magnetic sensor is composed of an induction coil and signal processing circuits. Based on electro- magnetic induction principle, the induction coil converts the alternating magnetic signal into induced electrical signal, which is processed by the signal processing circuits to extract useful electrical signal from strong background noise. From the input-output characteristics of the magnetic sensor, the magnitude of the alternating magnetic field can be acquired. The experiment result shows that the magnetic sensor can measure weak alternating magnetic field, has wide measurement range, high resolution, high precision and good stability. The magnetic sensor can be used to measure weak magnetic fields with large field strength span in non-magnetic circumstances.