Carré P, Leman H, Fernandez C, Marque C
Ircom-SIC Laboratory, UMR CNRS, Futuroscope, France.
IEEE Trans Biomed Eng. 1998 Sep;45(9):1104-13. doi: 10.1109/10.709554.
We propose two original methods of denoising of the uterine electrohysterography (EHG) signal by wavelets. This external electrophysiological signal is corrupted by electronic, electromagnetic noises and by the remaining electrocardiogram of the mother. The interfering signals have overlapping spectra. Therefore, a classical filtering is unusable. Wavelets should be a very well-suited denoising tool. The first proposed method uses the algorithm "à trou" with nonsymmetrical filters. The computation is rapid and the results are satisfying compared to the classical denoising techniques. The second algorithm is an improvement of the first method. It uses orthogonal wavelets and the result of the thresholding corresponds to the average of all circulant shifts denoised by a decimated wavelet transform. Results are compared to traditional denoising algorithms by wavelet (orthogonal, maximally decimated). The proposed algorithms are more efficient on simulated signals as well as on uterine EHG.
我们提出了两种通过小波对子宫电子宫造影（EHG）信号进行去噪的原创方法。这种外部电生理信号会受到电子、电磁噪声以及母亲剩余心电图的干扰。干扰信号具有重叠频谱。因此，传统滤波方法无法使用。小波应该是一种非常适合的去噪工具。第一种提出的方法使用带有非对称滤波器的“à trou”算法。与传统去噪技术相比，计算速度快且结果令人满意。第二种算法是对第一种方法的改进。它使用正交小波，阈值处理的结果对应于通过抽取小波变换去噪的所有循环移位的平均值。通过小波（正交、最大抽取）将结果与传统去噪算法进行比较。所提出的算法在模拟信号以及子宫EHG信号上都更有效。
