中国物理B ›› 2006, Vol. 15 ›› Issue (1): 100-103.doi: 10.1088/1009-1963/15/1/016

• GENERAL • 上一篇    下一篇

A digital filtering scheme for SQUID based magnetocardiography

朱学敏, 任育峰, 于洪伟, 赵士平, 陈赓华, 张利华, 杨乾声   

  1. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
  • 收稿日期:2005-05-26 修回日期:2005-09-01 出版日期:2006-01-20 发布日期:2006-01-20
  • 基金资助:
    Project supported by the Major Program for the Fundamental Research of Chinese Academy of Sciences, China (Grant No KJCX2-W4) and the National High Technology Research and Development Program of China (Grant No 2002AA306412).

A digital filtering scheme for SQUID based magnetocardiography

Zhu Xue-Min (朱学敏), Ren Yu-Feng (任育峰), Yu Hong-Wei (于洪伟), Zhao Shi-Ping (赵士平), Chen Geng-Hua (陈赓华), Zhang Li-Hua (张利华), Yang Qian-Sheng (杨乾声)   

  1. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, China
  • Received:2005-05-26 Revised:2005-09-01 Online:2006-01-20 Published:2006-01-20
  • Supported by:
    Project supported by the Major Program for the Fundamental Research of Chinese Academy of Sciences, China (Grant No KJCX2-W4) and the National High Technology Research and Development Program of China (Grant No 2002AA306412).

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摘要： Considering the properties of slow change and quasi-periodicity of magnetocardiography (MCG) signal, we use an integrated technique of adaptive and low-pass filtering in dealing with two-channel MCG data measured by high $T_{\rm c}$ SQUIDs. The adaptive filter in the time domain is based on a noise feedback normalized least-mean-square (NLMS) algorithm, and the low-pass filter with a cutoff at 100Hz in the frequency domain characterized by Gaussian functions is combined with a notch at the power line frequency. In this way, both relevant and irrelevant noises in original MCG data are largely eliminated. The method may also be useful for other slowly varying quasi-periodical signals.

Abstract: Considering the properties of slow change and quasi-periodicity of magnetocardiography (MCG) signal, we use an integrated technique of adaptive and low-pass filtering in dealing with two-channel MCG data measured by high $T_{\rm c}$ SQUIDs. The adaptive filter in the time domain is based on a noise feedback normalized least-mean-square (NLMS) algorithm, and the low-pass filter with a cutoff at 100Hz in the frequency domain characterized by Gaussian functions is combined with a notch at the power line frequency. In this way, both relevant and irrelevant noises in original MCG data are largely eliminated. The method may also be useful for other slowly varying quasi-periodical signals.

Key words: SQUIDs, adaptive filter, magnetocardiography

中图分类号:  (Biophysical techniques (research methods))

  • 87.80.-y
87.19.Hh (Cardiac dynamics) 85.25.Dq (Superconducting quantum interference devices (SQUIDs)) 07.55.-w (Magnetic instruments and components) 02.70.Rr (General statistical methods)