多通道心磁系统标定方法研究

Multi-channel magnetocardiogardiography system calibration

在多通道超导量子干涉器件(SQUID)磁探测系统中,磁场-电压转换系数(B/V)是系统的一个重要参数.由于SQUID器件和读出电路之间不可避免地存在差异性,因此对传感器系统进行系统标定(每个通道的单独标定)显得十分重要.本文采用PCB板印制圆形线圈对36通道心磁系统进行标定,并与传统的亥姆霍兹方形线圈产生均匀场的标定方法进行比较.结果显示,PCB圆形线圈的标定结果在1.46—1.73 p T·m V-1之间,亥姆霍兹方形线圈标定的结果大都在1.56—1.64 p T·m V-1之间,结果基本一致.

The field-to-voltage transfer coefficient （B/V ） is an important parameter of the multi-channel superconducting quantum interference device （SQUID） magnetic detecting system. The SQUID devices and the readout circuits have the inevitable differences among different channels, so the accurate calibration of system channels is rather significant. In this paper, We first used the circular PCB coils for 36-channel MCG system calibration, and the other one is based on a traditional method in which a uniform field is produced by square Helmholtz coil. The calibration data show that the results are basically the same. The calibrated B/ V values using circular PCB coils are in a range from 1.46-1.73 ·mV^-1. And those of square Helmholtz coils are mostly within a range from 1.56-1.64 pT·mV^-1.