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1.
将心磁信号从干扰噪声中加以提取并有效地消除噪声干扰是心磁信号处理中尤为重要的环节 .从改进算法的角度出发,提出互补型自适应滤波器结构以实现心磁信号的消噪处理.该滤波器针对心磁这类非平稳信号进行设计,有效地解决了常规自适应滤波器应用于心磁信号处理时收敛速度和稳态误差的矛盾.通过仿真实验和心磁实验结果表明,该算法能有效地消除心磁信号的背景噪声和工频干扰噪声.同时该算法也可用于其他非平稳信号的消噪处理.
关键词:
自适应滤波
心磁图
最小均方误差 相似文献
2.
A dual-washer superconducting quantum interference device(SQUID) with a loop inductance of 350 pH and two onwasher integrated input coils is designed according to conventional niobium technology. In order to obtain a large SQUID flux-to-voltage transfer coefficient, the junction shunt resistance is selected to be 33 ?. A vertical SQUID gradiometer module with a baseline of 100 mm is constructed by utilizing such a SQUID and a first-order niobium wire-wound antenna.The sensitivity of this module reaches about 0.2 fT/(cm·Hz1/2) in the white noise range using a direct readout scheme, i.e.,the SQUID is directly connected to an operational amplifier, in a magnetically shielded room. Some magnetocardiography(MCG) measurements with a sufficiently high signal-to-noise ratio(SNR) are demonstrated. 相似文献
3.
T. Varpula 《Il Nuovo Cimento D》1983,2(2):624-641
Summary Magnetic-susceptibility plethysmography (MSPG) is a new method proposed for monitoring cardiac-volume changes. The measurement
principle and recent work by other investigators are reviewed. The effect of the cardiac-related motion of the anterior chest
wall on the MSPG signal is studied. The results suggest that the motion of the chest-wall-air boundary may contribute significantly
(∼75%) to the MSPG signal when recorded near the heart.
Paper presented at the ?IV International Workshop on Biomagnetism?, held in Rome, September 14–16, 1982. 相似文献
4.
5.
Summary Sloping signals were observed in thePR segment of normal magnetocardiograms recorded from five dogs. Larger ramps were observed after first-degree AV nodal blockade
was induced pharmacologically, and complete atrial repolarization was observed following isolated atrial contractions in two
animals with second-degree block. These ramps, ranging up to 6.7 pT in size and arising from the atria, may complicate magnetic
detection of His-Purkinje activity.
This work was supported by the National Institute of Health under Grant No. HL 23184. 相似文献
6.
J. R. Storey 《Il Nuovo Cimento D》1983,2(2):153-165
Summary Principles are established for the design of coil arrays which generate distant magnetic fields diminishing as a high inverse
power of the distance. By a principle of reciprocity these arrays, when used as sensors in induction and SQUID magnetometers,
have an inherently low sensitivity to distant sources of magnetic field.
Paper presented at the ?IV International Workshop on Biomagnetism?, held in Rome, September 14–16, 1982. 相似文献
7.
Summary Magnetic fields of the brain were recorded preceding selfinitiated finger, foot, toe movements, stimulus-triggered finger
and toe movements, and speech. Slow magnetic-field shifts were found with morphology similar to coincident electrical potentials,
but with very different distributions. Inferences from the data about localization of cerebral generators were discussed.
These studies were supported by grants from the B.C. Research Council and N.S.E.R.C. of Canada. 相似文献
8.
Summary We have constructed a three-channel differential SQUID magnetometer for the simultaneous measurement of the three orthogonal
components of the magnetic field in the same location. The structure of the device is described and MCG data measured are
shown. Interference effects between the channels are discussed.
A preliminary report of this work has been presented 相似文献
9.
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. 相似文献
10.
Singular value decomposition with normalized period for magnetocaridiography signal processing
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In this paper, we have developed an algorithm based on singular value
decomposition (SVD) for matrix. And the novel SVD algorithm with normalized
period of cardiac cycles is presented. The results from real
magnetocardiography (MCG) data processing show that the new algorithm is
better than the standard one not only in suppressing noises, but also in
providing high-fidelity MCG signals. 相似文献