Application of Wavelet Threshold Denoising

In the actual acquisition process, the collected signal is inevitably interfered by various factors such as noise or environment. How to remove the noise signal in the signal and analyze the useful signal is a hot issue in current research. In recent years, the wavelet theory has been rapidly developed, and the use of wavelet threshold denoising is a newly developed method to remove noise. The use of wavelet threshold denoising has good effects and can effectively improve the signal-to-noise ratio.

Using the characteristics of wavelet transform multi-scale multi-resolution, the ECG signals are decomposed, and the signals of different frequency bands appear on different scales of wavelet decomposition. When performing signal reconstruction, the information of high-frequency interference and baseline drift is removed. The reconstructed signal no longer contains interference components in order to correctly estimate the characteristic parameters of the ECG signal and detect the desired ECG waveform, thereby extracting diagnostic value information.

The standard ECG data used in this experiment is derived from the MIT-BIH database, as shown in Figure 1, with a sampling rate of 360 Hz and an A/D conversion accuracy of 12 bits. Gaussian white noise is added to the standard ECG signal to simulate the noise pollution signal, and the signal-to-noise ratio is 10dB, as shown in Figure 2.

Figure 1 Standard ECG signal

Figure 2 Noise-containing ECG signal

Firstly, we use the cubic B-spline wavelet to perform the binary discrete wavelet transform on the ECG signal containing noise. The scale is taken as 4, and the wavelet transform coefficients of each scale of the signal are calculated. The transformation result is shown in Figure 3: Then according to the soft threshold The method uses the threshold set by the adaptive threshold method to adjust the wavelet transform coefficient, removes the random noise in the ECG signal, and finally inversely transforms the adjusted wavelet transform coefficient, so that the denoised signal data is obtained. The simulation diagram is shown in Figure 4:

Figure 3 Four-scale wavelet decomposition of ECG signals

Figure 4 ECG signal after denoising with adaptive threshold under soft threshold

General Purpose Steel Wire Rope

Aircraft Cable And GP Steel Wire Rope

Widely used in the industry of Port Machinery, Vessels, Elevators, Engineering Machinery, Mining, Petroleum, etc
GAC: 7x7 7x19
GP steel wire rope: 1x7 1x19 6x7 7x7 6x19 7x19 6x12 6x24 6x37
Surface: (1) hot-dip galvanized; (2) electric galvanized; (3) black; (4) PVC coating; (5) stainless steel; (6) zinc + aluminum, etc.

Steel Wire Rope,Galvanized Wire Rope,Galvanized Steel Wire Rope,Galvanized Aircraft Cable

ROYAL RANGE INTERNATIONAL TRADING CO., LTD , https://www.royalrangelgs.com