A digital filtering scheme for SQUID based magnetocardiography

• 来源期刊: 中国物理（英文版）
• 关键词: SQUIDs adaptive filter magnetocardiography
• 年，卷（期）: 2006,（1）
• 页码范围: 100-103
• 页数: 4页
• 语种: 英文

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 Tc 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.