Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi
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Sheng Wu Yi Xue Gong Cheng Xue Za Zhi · Aug 2005
[Research and application of microcontroller system for target controlled infusion].
This paper presents a microcontroller system for target controlled infusion according to pharmacodynamic parameters of intravenous anesthetics. It can control the depth of anesthesia by adjusting the level of plasma concentrations. The system has the advantages of high precision, extending power and easy manipulation. It has been used in the clinical anesthesia.
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Sheng Wu Yi Xue Gong Cheng Xue Za Zhi · Aug 2005
[Pulse pressure and mean pressure relationship of intracranial pressure and lumbar cerebrospinal fluid pressure].
Intracranial pressure fluctuates due to heart beat, respiration, neuro-regulation, etc. Traditional intracranial pressure study focuses on the static pressure and related factors, putting emphasis on mean intracranial pressure, while paying little attention to the pulse components. This study was composed of two parts: animal experiment and theoretical analysis. ⋯ The same result was obtained in the lumbar cerebrospinal fluid pressure. Therefore, the lumbar cerebrospinal fluid pressure is consistent with the intracranial pressure. Intracranial pulse pressure is in linear relationship with mean pressure, and the slope of their linear relationship predicts the perform of intracranial autoregulation.
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Sheng Wu Yi Xue Gong Cheng Xue Za Zhi · Aug 2005
[Application of independent component analysis to ECG cancellation in surface electromyography measurement].
Surface electromyogram usually incurs severe influence of strong electrocardiography (ECG) signal. This paper presents a novel denoise method using independent component analysis (ICA) to remove the interference of ECG from sEMG recordings. ⋯ The filtering ICA ECG cancellation results were compared with the simulated pure sEMG in time and frequency domain, which suggested that the ICA ECG cancellation with 30Hz high-pass filter would be the most appropriate method to extract the useful sEMG signals from multi-channel sEMG measurement. The kurtosis is used to measure the nongaussianity of signal; it may beused as a standand for automatic determination of the independents of ECG or EMG.
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Sheng Wu Yi Xue Gong Cheng Xue Za Zhi · Feb 2005
[The solving and simulation of cable equation under the stimulation of point electrical source].
The character of the membrane of fiber can be simulated by nonpower RC network on condition that the offset of distance between the transmembrane potential of unmyelinated nerve fiber and the resting potential of nerve fiber cell is small enough. Thus, it is possible to found the successive cable equation with external stimulation under subthreshold linear state. ⋯ In this paper are reported the method of integral transform and the analytical expression of cable equation under the stimulation of point electrical source firstly. And at the same time, computer-aided simulation of transmembrane potential of nerve fiber and analysis of the possibility of activating action potential are presented.
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Sheng Wu Yi Xue Gong Cheng Xue Za Zhi · Feb 2005
[Determination of optimal complexity for long ECG sequence].
In this article is reported a study on the optimal complexity of the long electrocardiogram (ECG) signal. At first, the original signal sequence was symbolized, then its complexity was calculated by Lempel-Ziv algorithm, and different factors of the complexity were discussed, and three different kinds of ECG signals, i.e., normalcy, angina and myocardial infarction, were studied. The results indicate that the optimal threshold-value to symbolize the original signal and the optimal signal length are two main factors that affect the complexity value, and the optimal complexity value can effectively distinguish normal ECG and patients' ECG.