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 2014
[Closed-loop control for chest compression based on coronary perfusion pressure: a computer simulation study].
In this study, a closed-loop controller for chest compression which adjusts chest compression depth according to the coronary perfusion pressure (CPP) was proposed. An effective and personalized chest compression method for automatic mechanical compression devices was provided, and the traditional and uniform chest compression standard neglecting individual difference was improved. ⋯ The performance of the fuzzy controller was evaluated and compared to that of a traditional PID controller in computer simulation studies. The simulation results demonstrated that the fuzzy closed-loop controller produced shorter regulation time, fewer oscillations and smaller overshoot than those of the traditional PID controller and outperforms the traditional PID controller in CPP regulation and maintenance.
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Sheng Wu Yi Xue Gong Cheng Xue Za Zhi · Aug 2014
[Effects of propofol, etomidate and ethanol on GPCR mRNA expression in Daphnia pulex ].
The mechanisms of general anesthesia, which was introduced about 170 years ago, remain poorly under- stood. Even less well understood are the effects of general anesthesia on the human body. ⋯ Phylogenetic analysis identified these genes to be the homologs of the human γ-aminobutyric acid, type B (GABAB) receptor, metabotropic glutamate receptors (mGluR), adrenergic receptor, serotonin (5-HT) receptor, dopamine receptor and muscarinic acetylcholine receptor (mAChR). Using reverse transcription and quantitative PCR techniques, we systematically measured the effects of propofol, etomidate and ethanol on these 18 GPCR mRNA expressions in Daphnia pulex.
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Sheng Wu Yi Xue Gong Cheng Xue Za Zhi · Aug 2014
[Effect of hemorheology on ultrasonic doppler blood flow spectrum diagram].
The present research aims to point out the long-existing defect of analyzing the spectrum diagram only from the perspective of haemodynamics instead of haemorheology. In the light of the theories of haemodynamics and haemorheology, the causes of spectrum diagram formation of carotid artery blood at the rapid and slow flow can be clarified completely and accurately. Four conclusions have been drawn in the end. As long as the velocity gradient is large enough, obvious red blood cells concentrate to the shaft even in the big or bigger blood vessels; the spectrum diagram is the powerful proof of the two phase flow model of blood; the spectrum diagram can be completely and accurately analyzed only by combining haemodynamics with haemorheology; and only when the red blood cells concentrate to the shaft, the big or bigger blood vessels can be regarded as haemogeneous fluid.
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Sheng Wu Yi Xue Gong Cheng Xue Za Zhi · Aug 2014
[Study on real-time monitoring and assessment of near-infrared in the dehydration treatment of traumatic brain injury].
We used near-infrared spectroscopy technology to monitor and assess the treatment effect of dehydrating agent in injured rat brain in real time style. We employed the brain edema model in rats resulting from Feeney' s freefall damage, then treated with different doses of mannitol, and collected reduced scattering coefficient (p',) and intracranial pressure (ICP) values after the injury and during the treatment. The results showed that brain edema happened 1 h after the injury in rats' brain tissue, peaked around 72 h after injury, and then began to decrease gradually. ⋯ Compared with the effect of low-dose mannitol treatment, that of high-dose mannitol treatment was much better. The duration of the plateau was longer and most experiments results declined significantly. From this we conclude that the reduced scattering coefficient and ICP are consistent with the trend changes, and the reduced scattering coefficient could be used as an indicator for monitoring cerebral edema.