Nonlinear dynamic analysis of mitral valve doppler signals: surrogate data analysis

To reduce the dynamic responding time of cryogenic valve, and improve the reliability and security of cryogenic valve, depending on the operation principle of cryogenic valve, a dynamic responding transferring non-linear function and dynamic responding model of cryogenic valve were built based on kinetics theory. Afterwards, by means of Runge-Kutta solution method, a dynamic recursive four stages Runge-Kutta solution method was constructed by the introducing of changed step length coefficient and oblivion coefficient. Finally, this method was demonstrated and validated by a sample. Consequently, this method has provide a support for reducing dynamic responding time of cryogenic valve, and has provide an approach to rationally and exactly evaluating reliability and security of cryogenic valve.

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A test and simulation device for Doppler-based fetal heart rate monitoring

Mert¹,

Sezdi²,

Akan³

2015

Turk J Elec Eng & Comp Sci

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Abstract:The Doppler effect is the preferred technique in fetal heart rate (FHR) monitoring devices. The main objective of the recent studies on the Doppler FHR has been to improve the accuracy. On the other hand, a reliable fetal heart simulator becomes essential for testing Doppler FHR monitoring devices. The motivation of this study is to design a reliable system that will be used to test Doppler FHR monitors. This device generates a similar Doppler frequency shift of fetal cardiac activity including the heart's wall and valve motions. The components of this system are basically a signal generator using a microcontroller and a modified relay. The relay is the most important and studied component that affects the Doppler frequency shift. Thus, the relay's contact distance and length as well as its closing and opening velocities have been modified to produce an appropriate Doppler shift to fetal cardiac motion. This device has been tested and its reliability has been proved.

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Nonlinear dynamic analysis of mitral valve doppler signals: surrogate data analysis

Cited by 3 publications

References 23 publications

Characteristics of earthquake occurrences based on chaotic analysis and fractal dimension

Characteristics of earthquake occurrences based on chaotic analysis and fractal dimension

A Dynamic Responding Characteristic Non-linear Analyzing Method of Cryogenic Valve

A test and simulation device for Doppler-based fetal heart rate monitoring

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