Journal Detail Information

1

Cite

Share

Design and Performance Study of Focused Magnetic Fields Conductivity Tomography.

Space Medicine & Medical Engineering.2006;0(01):-.

Objective To design a system of conductivity tomography using focused magnetic fields for data acquisition. Method A frequency modulation detection circuit with array of sources was employed to implement multi-frequency measurement. In the circuit, a specially designed coil with good focusing property was used to improve spatial resolution of the image. Acquired data of frequency changes from the detector was stored in the memory operated by a ping-pang pattern, then the data was transmitted into computer by serial communication interface whose transmitting rate reached 115. 2 KHz. Result Frequency stability of the signal source in the system reached 0. 2%; the total harmonic distortion of the signal was less than -43 dB; the signal noise ratio of the source was from 58 dB to 62 dB. The storage capacity of memory was 131 072-word by 16- bit. The system has good frequency resolution, and is easy to be analyzed and processed by the software after data acquisition. The conductivity of the computed results agreed with that in the given model. Conclusion The system is effective to detect and reconstruct the conductivity of stratified biological tissue for its high sensitivity.

2

Cite

Share

A New Algorithm for Oscillometric Blood Pressure Measurement.

Xiaoli QUAN ; Wei HE ; Weiwei ZHANG

Space Medicine & Medical Engineering.2006;0(01):-.

Objective To find a new algorithm for oscillometric blood pressure measurement. Method A coefficient difference comparative method was proposed to measure the difference of adjoining pulse waves and their comparative ratios. And the turning point was judged by priority way in the range. Result The new method settled the problem of miscarriage of justice of the turning point around average pressure and improved the accuracy of blood pressure measurement. Conclusion It can detect difference between cardiovascular patients and normal persons. And it is effective and reliable in blood pressure measurement. It provides a convenient method for researching, preventing and epidemiological studies of cardiovascular diseases in our country.

3

Cite

Share

Acquisition of Pulse Characteritics Based on Wavelet Module Maximum Principle.

Yan WANG ; Tao BAI ; Jingli KANG

Space Medicine & Medical Engineering.2006;0(01):-.

Objective To study a wavelet method for acquiring the characters of pulse wave based on the principle of wavelet transform which can effectively solve the problem of inaccuracy of the conventional methods. Method The method of wavelet module maximum was used to divide the pulse wave according to periods and basically decomposed it, by arranging in time order and symbolizing the module maximum character points of pulse wave signal at the ascending and descending edges as well as the crest and trough. Result Through the method, the unobvious dicrotism, trail wave and the anomalistic wave appearing at the ascending and descending edge of the main wave, and multi-scale characters and all kinds of characters in time domain of pulse signal were further acquired more accurately. Conclusion Simplicity, quickness and accuracy are achieved by focusing on the character points of pulse signals. It provides a new means for further studies of classification and identification of pulse signals.

4

Cite

Share

Effects of Modafinil on Vestibular Function during 24 h Sleep Deprivation.

Hao ZHAN ; Sujiang XIE ; Hongbo JIA ; Sihuang WEI ; Baisheng JING ; Tong LI

Space Medicine & Medical Engineering.2006;0(01):-.

Objective To investigate the effects of modafinil,a new wake-promoting agent, on vestibular function during 24 h sleep deprivation(SD). Method Eight male healthy young volunteers were exposed to two 24 h periods of continuous wakefulness during the crossover experiment. In one period, 200 mg doses of modafinil were given and in the other, separated by one week, matching placebos were administered. The SD time started from 8:00 of the first day to 8:00 of the second day. Drugs was given at 0:00 of the second day. Vestibular function was tested at 21:00 of the first day and 1 ,3,5,7 h after drug administration. Result The accuracy of saccade tracking and the gains of VVOR(visual-vestibular optokinetic reflex)and OKN(optokinetic nystagmus)in the placebo group decreased during 24 h SD, especially at 1: 00～5:00 of the second day, while OKN gains in the modafinil group was increased significantly. There were no significant differences of other vestibular function between modafinil group and placebo group. Conclusion Twenty four SD can influence vestibular function in certain degree,but optokinetic nystagmus can be improved by modafinil.

5

Cite

Share

Effects of 10 h Continuous Driving on Auditory Involuntary Attention:An ERPs Study.

Guoping SONG ; Lun ZHAO ; Kan ZHANG

Space Medicine & Medical Engineering.2006;0(02):-.

Objective To investigate effects of driving fatigue on auditory involuntary attention.Method Between-groups design was used.The control group included 13 taxi drivers after adequate rest while the fatigue group included 13 taxi drivers who had been driving for 10 h.Auditory oddball pattern was adopted.The standard stimulus was 800 Hz,probability 80%;target stimulus was 1 000 Hz,probability 10%;novel stimulus was sound generated by computer or other sound,probability 10%.Subjects were asked to press the mouse upon hearing the target sound.Result The distribution of P3a was mainly around the frontal-central area of the subjects in control group;the amplitude of P3a was evidently lowered in subjects after driving fatigue.Conclusion The ability of auditory involuntary attention declines after driving fatigue.

6

Cite

Share

3D Reconstruction of High-resolution Volume Data Based on Surface Points.

Bin ZHUGE ; Heqin ZHOU ; Wenhui LANG ; Lei TANG ; Huanqing FENG

Space Medicine & Medical Engineering.2006;0(02):-.

Objective: To develop a way of high-quality real-time three dimension surface reconstruction for high-resolution volume data.Method 3D surface point sets of single organ were using a method of binding the threshold and morphological operations.The normal vector of every surface point was calculated.According to the gray gradients of volume data,the triangle face was replaced by surface points to describe the organ surface,and the surface was displayed with OpenGL interface of display card after defining the color and transparent of the organ surface.Result Based on hardware platform of personal computer,the reconstruction of skeleton and skin for the digitized virtual Chinese man No.1(VCH-M1) from CT database was constructed,the rendering speed was faster than 25 F/s.Conclusion The algorithm is capable of realizing a real-time rendering for 512?512?1720 high resolution volume data.

7

Cite

Share

Numerical Simulation of Carotid Bifurcation Flow Field in Atherosclerosis Model.

Yongmei NIE ; Huaiqing CHEN ; Wentao JIANG

Space Medicine & Medical Engineering.2006;0(02):-.

Objective To simulate local hemodynamic factors at particular arterial positions.Method A combination of high-lipid diet and immuoreactive injury was used to establish a hyperlipemia and atherosclerosis model in rabbit.Serrial sections were analysed by OLYSIA software.Data of caliber at different positions of carotid bifurcation,areas and circumference and thickness of the atherosclerotic plaque at carotid bifurcation were obtained and to establish a geometric model of rabbit carotid artery bifurcation with Gambit software.Wall shear stress distribution of the carotid sinus were analysed by numerical simulation.Result 1) A geometric model of rabbit carotid artery bifurcation was obtained.2) The wall shear stress of the carotid sinus of the atherosclerosis(AS) model group was found to be lower than that of the control group at shear rate 128.5 S~(-1).The lowest wall shear stress of the control was 4.028 times that of the AS model.Conclusion Low wall shear stress is a risk hemodynamic factor in the development of atherosclerotic plaque.

8

Cite

Share

Implementation of Whole Visualization of 3D Medical Image by Semitransparent Effect.

Hua BAO ; Tianfu WANG ; Jiangli LIN ; Deyu LI

Space Medicine & Medical Engineering.2006;0(02):-.

Objective To improve the key steps of direct volume rendering(DVR) method to obtain ideal semitransparent 3D visualization of medical images from 2D slices.Method An arbitrary data set was classified into a simple one and a complex one according to the boundaries existing within the data set,thereby a piecewise linear function was used to construct the transfer function(TF).Low-grayed voxels were regarded as a kind of material which did not radiate but do induce attenuation of sampling lights.The TF was adjusted according to the opacity distribution when one resampling process ends,and the rendering procedure was completed.Result Interior structures of tissues in different levels were rendered.Conclusion Multi-level visualization of 3D medical images for the semitransparent effect can be obtained by considering all the tissues in the data set as semitransparent materials.

9

Cite

Share

Correlation Analysis of Epicardial Depolarization Wave Based on Combined Unipolar and Bipolar Mapping Technique.

Cuiwei YANG ; Zuxiang FANG ; Xiaomei WU

Space Medicine & Medical Engineering.2006;0(02):-.

Objective To find a method for real-time measurement of epicardial electrical activity suitable for clinical application.Method Combined unipolar and bipolar mapping technique for recording epicardial electrical activity was applied to detect the propagation of depolarization wave over the epicardium.Epicardial signals from 4 pigs were sampled simultaneously during sinus rhythm or atrial fibrillation(AF).Result Active isopotential map showing the spread of excitation on epicardial surface was demonstrated and correlation analysis data were obtained.The difference in correlation coefficients between adjacent sites was evident during sinus rhythm(above 0.8) and AF(about(0.5).) Conclusion The result shows that combined unipolar and bipolar technique improves the electrode efficiency and the precision in epicardial mapping.Distribution of depolarization wave or the reentry pathway during complex arrhythmia may be revealed by correlation analysis.

10

Cite

Share

Studies on Selection and Biological Characters of Tomato Indeterminate Growth Habit Mutant Derived from Space Treatment.

Yanfang WANG ; Jirong ZHENG ; Shiheng WANG ; Shuijin ZHU

Space Medicine & Medical Engineering.2006;0(02):-.

Objective To select excellent tomato mutants by space treatment and to cultivate directively new varieties for production application.Method Growth dynamics and change of agricultural characters of the mutant of indeterminate growth habit was observed.And the enzymogram and activity of two kinds of main isoenzyme were analyzed.Result An indeterminate growth habit mutant(M1) which derived from a determinate growth habit cultivar(10-3-2) was obtained from the 1st generation after space treatment(SP_1).Being an inherited character,the indeterminate growth habit of the mutant can be expressed from generation to generation.The plant height of M1 was 145 cm,42.0 cm higher than that of the background one(increased by 29.6%),when the background plant height was determined.The main stem diameter of the mutant was 1.22 cm,0.34 cm thicker than that of background parent.However,there were no visible difference in the fruit size and fruit set percentage between them.The biological characters of M1 and its progenies were studied,and the results showed that the indeterminate growth have no side effects on the agronomic characters and fruit quality,and the mutant had a potentiality of higher yield if the condition is suitable.The activity of two enzymes,SOD and POD,was assayed and there were no obvious difference of SOD activities and enzymograms between the mutant and its background parent,but POD activity was much lower in mutant than that in its background parent.Conclusion After observation through 3 generations,it is found that indetermination growth habit is inheritable and stable.

DISPLAY OPTIONS

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share

Cite

Share