1.Residual voltage of terms and test method.
Chinese Journal of Medical Instrumentation 2010;34(3):215-217
This paper describes 5 national standards related to the term on the residual voltage with different indicators. Compare the advantages and disadvantages of various test methods. Finally, give suggestions on improving the testing method.
Electric Capacitance
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Electric Impedance
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Electricity
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Reference Standards
2.Troubleshooting of Electro-Static Discharge Test for Medical Injection Pump.
Zhengjie SUN ; Dan HUANG ; Lianjun LIN ; Kun DU
Chinese Journal of Medical Instrumentation 2015;39(3):216-218
This article presents several common problems.of medical injection pump through one case of ESD troubleshooting. Expounds the causes of the problem and provides solutions.
Equipment and Supplies
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Injections
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instrumentation
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Static Electricity
3.Modeling and experimental study on frequency-domain electricity properties of biological materials.
Hua TIAN ; Shiqiang LUO ; Rui ZHANG ; Gang YANG ; Hua HUANG
Journal of Biomedical Engineering 2009;26(6):1349-1352
Frequency-domain electricity properties of four objects, including bullfrog skin, bullfrog muscle, triply distilled water and 0.9% NaCl, were tested in the range of 100Hz-10MHz using home-made electrode and measuring system. The experimental results showed that the resistance of 0.9% NaCl decreased dramatically, that the amplitude frequency characteristics of bullfrog's muscle and skin were similar, but that of triply distilled water did not change significantly. The frequency dependence of 0.9% NaCl showed that the electrode had great influence on the measuring system, so a new equivalent circuit model based on the electrode system was needed. These findings suggest that the new five-parameter equivalent circuit model, which embodies considerations on the interaction between electrodes and tissues, is a reasonable equivalent circuit for studying the electrical characteristics of biological materials.
Animals
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Electric Capacitance
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Electric Impedance
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Electricity
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Electrodes
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Muscle, Skeletal
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physiology
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Rana esculenta
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Skin
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Sodium Chloride
4.Research on Constant-current Characteristics of Howland Current Source Used in Bioelectrical Impedance Detection.
Xingjian LIN ; Weijie ZHAO ; Xiaojuan LIU ; Lihua LI
Journal of Biomedical Engineering 2015;32(2):290-294
This study aims to analyze and improve Howland current source circuit and to study the constant current source of alternating current with high output impedance and high stability. A simulation study was carried out on the constant-current characteristics of Howland current source from two aspects of resistance match value and the selection of Op amp parameters, and then the output impedance was analyzed. The simulation experiment showed that when it was with the best matched resistance, the constant-current characteristics of Howland current source was better. Op amp parameters could affect the constant-current characteristics of Howland current source. In Howland current source circuit, the current source after parameter optimization had better output impedance and load capacity. The results showed that there was the best matched resistance in the selection by Howland current source. The Op amp with large broadband, high slew rate and open loop gain, and wide range of power supply voltage is more suitable for the bioelectrical impedance detection circuit.
Electric Impedance
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Electric Power Supplies
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Electricity
5.Electrostatic protection of oxygen pressure cabins.
Zhi-Man ZHENG ; Jin-Feng LIU ; Xiao-Shan HUANG ; Wei-Chun LIU
Chinese Journal of Medical Instrumentation 2005;29(2):138-139
This paper describes electrostatic harms to oxygen pressure cabins and protection measures which should be taken.
Fires
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prevention & control
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Humans
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Humidity
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Hyperbaric Oxygenation
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Oxygen Inhalation Therapy
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instrumentation
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Static Electricity
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adverse effects
6.Semen-derived enhancer of viral infection--a key factor in sexual transmission of HIV.
Jiang-Man DUAN ; Jia-Yin QIU ; Sui-Yi TAN ; Shu-Wen LIU ; Lin LI
Chinese Journal of Virology 2012;28(1):84-88
Semen-derived enhancer of viral infection(SEVI) is a peptide fragment (PAP248-286) from prostatic acid phosphatase(PAP), which can enhance human immunodeficiency virus infection. The mechanisms of SEVI include: (1) SEVI with several cationic amino acid residues reduced electrostatic repulsion between HIV virus and the target cells; (2) The disorder state of SEVI in the human body fluids was helpful to the interaction between virus and the target cell membranes; (3) SEVI could capture HIV particles directly and speed the velocity of virus on the surface of the target cells and improve adsorption and fusion. Currently, the substances of inhibiting SEVI activity include: EGCG from green tea, small molecule compound of aminoquinoline Surfen, ThT analogs BTA-EG6. Those compounds might block the combination of HIV and SEVI or prevent the formation of amyloid fibers, and then reduce the enhancement of SEVI. The studies on the biological characteristics and mechanisms of SEVI have a big benefit for the prevention and treatment of HIV infection.
HIV Infections
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etiology
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transmission
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Humans
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Male
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Semen
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physiology
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Sexually Transmitted Diseases, Viral
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etiology
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Static Electricity
7.Adsorption of chondroitin sulfate-A to the surface of titanium.
Hong FAN ; Zhiqing CHEN ; Ping ZHANG ; Jing QIU
Journal of Biomedical Engineering 2003;20(4):650-667
To elucidate the adsorption mechanism of CS-A to the surface of titanium, 5 ml solutions of the CS-A were reacted with 2 g of native and 2 g of calcium-treated titanium powder for 48 h at 37 degrees C. Residual CS-A was detected by the carbazole elaborate method. The results showed that no CS-A attached to native titanium. Comparatively, titanium treated with calcium produced a significant adsorption of CS-A. At concentration of 60 micrograms/ml, the adsorption of CA-A to calcium-treated titanium powder attained the maximum, 83 micrograms/g. Only EDTA can liberate the bound CS-A from titanium surface. These findings suggest that calcium ion is necessary for the adsorption of CS-A to titanium.
Adsorption
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Calcium
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Chondroitin Sulfates
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pharmacology
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Static Electricity
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Surface Properties
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Titanium
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chemistry
8.Research on magneto-acoustic-electrical tomography method based on liquid metal contrast agent and M sequence coded excitation.
Yuheng WANG ; Junjie LIN ; Wenshu MAI ; Zhipeng LIU ; Tao YIN ; Shunqi ZHANG
Journal of Biomedical Engineering 2023;40(4):718-724
Magneto-acoustic-electric tomography (MAET) boasts high resolution in ultrasound imaging and high contrast in electrical impedance imaging, making it of significant research value in the fields of early tumor diagnosis and bioelectrical monitoring. In this study, a method was proposed that combined high conductivity liquid metal and maximum length sequence (M sequence) coded excitation to improve the signal-to-noise ratio. It was shown that, under rotational scanning, the liquid metal significantly improved the signal-to-noise ratio of the inter-tissue magneto-acoustic-electric signal and enhanced the quality of the reconstructed image. The signal-to-noise ratio of the signal was increased by 5.6, 11.1, 21.7, and 45.7 times under the excitation of 7-, 15-, 31-, and 63-bit M sequence code, respectively. The total usage time of 31-bit M sequence coded excitation imaging was shortened by 75.6% compared with single-pulse excitation when the same signal-to-noise ratio was improved. In conclusion, the imaging method combining liquid metal and M-sequence coding excitation has positive significance for improving MAET image quality.
Contrast Media
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Electricity
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Electric Conductivity
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Acoustics
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Tomography
9.Brain MRI image segmentation based on active contour model using electrostatic field method.
Liang LIAO ; Tusheng LIN ; Weidong ZHANG
Journal of Biomedical Engineering 2008;25(4):770-789
A modified Snake algorithm for medical image segmentation based on improved Greedy method and electrostatic field model is presented in this paper. Based on Greedy method, this algorithm features a new adjacent point selection strategy and the corresponding criteria, which can be used for searching the potential snake points. A new external image force based on electrostatic field model and the simplified force field computation based on preprocessing image are also introduced. Comparative experiments indicate the validity of the method.
Algorithms
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Brain
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physiology
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Electromagnetic Fields
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Humans
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Image Processing, Computer-Assisted
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methods
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Magnetic Resonance Imaging
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methods
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Models, Theoretical
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Static Electricity
10.Deglycosylation altered the gating properties of rNav1.3: glycosylation/deglycosylation homeostasis probably complicates the functional regulation of voltage-gated sodium channel.
Qing XU ; Hui-Wen CHENG ; Hui-Qiong HE ; Zhi-Rui LIU ; Ming HE ; Hong-Tian YANG ; Zhi-Lei ZHOU ; Yong-Hua JI
Neuroscience Bulletin 2008;24(5):283-287
OBJECTIVETo examine the effect of deglycosylation on gating properties of rNav1.3.
METHODSrNav1.3 was expressed in Xenopus oocyte, with glycosylation inhibition by using tunicamycin. Two-electrode voltage clamp was employed to record the whole-cell sodium current and data were analyzed by Origin software. Those of glycosylated rNav1.3 were kept as control.
RESULTSCompared with glycosylated ones, the steady-state activation curve of deglycosylated rNav1.3 was positively shifted by about 10 mV, while inactivation curve was negatively shifted by about 8 mV.
CONCLUSIONGlycosylation altered the gating properties of rNav1.3 and contributed to the functional diversity.
Animals ; Electric Conductivity ; Electric Stimulation ; Gene Transfer Techniques ; Glycosylation ; drug effects ; Homeostasis ; drug effects ; physiology ; Ion Channel Gating ; drug effects ; physiology ; Membrane Potentials ; drug effects ; physiology ; NAV1.3 Voltage-Gated Sodium Channel ; Nerve Tissue Proteins ; physiology ; Oocytes ; Patch-Clamp Techniques ; Sodium Channels ; physiology ; Static Electricity ; Tunicamycin ; pharmacology ; Xenopus