A synthetic optically pumped gradiometer for magnetocardiography measurements  

作　　者：Shu-Lin Zhang Ning Cao 张树林;曹宁(Joint Laboratory of Bioimaging Technology and Applications,CAS-SIMIT&MEDI,Shanghai 201899,China;State Key Laboratory of Functional Materials for Informatics,Institute of Microsystem and Information Technology(SIMIT),Chinese Academy of Sciences(CAS),Shanghai 200050,China;Centre for Excellence in Superconducting Electronics,Chinese Academy of Sciences,Shanghai 200050,China;Shanghai Medi Instruments Ltd.,Shanghai 201899,China)

机构地区：[1]Joint Laboratory of Bioimaging Technology and Applications,CAS-SIMIT&MEDI,Shanghai 201899,China [2]State Key Laboratory of Functional Materials for Informatics,Institute of Microsystem and Information Technology(SIMIT),Chinese Academy of Sciences(CAS),Shanghai 200050,China [3]Centre for Excellence in Superconducting Electronics,Chinese Academy of Sciences,Shanghai 200050,China [4]Shanghai Medi Instruments Ltd.,Shanghai 201899,China

出　　处：《Chinese Physics B》2020年第4期215-217,共3页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant No.61701486)。

摘　　要：Magnetocardiography(MCG)measurement is important for investigating the cardiac biological activities.Traditionally,the extremely weak MCG signal was detected by using superconducting quantum interference devices(SQUIDs).As a room-temperature magnetic-field sensor,optically pumped magnetometer(OPM)has shown to have comparable sensitivity to that of SQUIDs,which is very suitable for biomagnetic measurements.In this paper,a synthetic gradiometer was constructed by using two OPMs under spin-exchange relaxation-free(SERF)conditions within a moderate magnetically shielded room(MSR).The magnetic noise of the OPM was measured to less than 70 fT/Hz1/2.Under a baseline of 100 mm,noise cancellation of about 30 dB was achieved.MCG was successfully measured with a signal to noise ratio(SNR)of about 37 dB.The synthetic gradiometer technique was very effective to suppress the residual environmental fields,demonstrating the OPM gradiometer technique for highly cost-effective biomagnetic measurements.

关 键 词：optically PUMPED magnetometer(OPM) magnetocardiography(MCG) GRADIOMETER 

分 类 号：TH776[机械工程—仪器科学与技术] TP212[机械工程—精密仪器及机械]