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Objective:Heart rate variability (HRV) contains a lot of information concerning the cardiovascular regulation,and can be an important indicator,quantitatively reflecting of autonomic nervous function and the normal heart activity,also can play an important role in cardiovascular regulation.Therefore,HRV signals are analyzed using common HRV analysis methods.Methods:Decompose HRV signals of congestive heart failure and normal persons into 6 scales using Multi-resolution analysis.The wavelet coefficient energy is calculated,especially the frequency energy of cd3 to cd6.Results:Energy is mainly concerned in the lower band of high frequency band and low frequency band,where the energy differences between the two groups are more evidence.It's more precise compared to the result with frequency-domain analysis.Conclusions:To gain results with universal law,more different analysis methods need to be improved and lots of researches are necessary.
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Objective In order to investigate the comlex course of electricity and mechanism of erosive gastritis(EG) and its relative factors,and to extract gastric motility feature indexes.Methods 30 volunteers of erosive gastritis were selected.The signal processing device was designed by Chongqing University of Posts and Telecommunications.By the means of spectrum analysis technic,the signals could be classified according to the dominant power and dominant frequency.Some indexes such as frequency of EGG and IGM,signal power spectrum and dynamic spectrum,the rates of rhythm and power for the normal EGG and IGM and so on could also be calculated.Results The power ratio in 2~4 cpm was 59.2?4.4,the frequency ratio was 70.4?25.5,the frequency instability coefficient was 0.182?0.059,and the power instability coefficient was 1.576?0.481.The parameters changed signifcantly between health adult and patient(P0.05).Conclusion The results of the experiments show that the method based on the synchronous measurement of EGG and IGM can provide a non-invasive way to investigate and evaluate erosive gastritis corresponding to gastrointestinal physiology and pathology conditions.
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Objecive To discuss a denoise method of gastric impedance signal based on wavelet transform and Stein Unbiased Risk Estimation rule.Methods Firstly,the signal was decomposed by Multi-resolution Analysis(MRA).Secondly,the signal was denoised by Stein Unbiased Risk Estimation rule,whose threshold was adaptive.Results The experimentation results demonstrated that breathing and blood flowing impedance interference could be cancelled effectively by using this method.Conclusion Wavelet analysis provides a new method for further study of gastric motility signal parameter extraction.