1.Research Advances of Multidimensional Reconstruction of Ultrasonic Heart Images
Tianfu WANG ; Changqiong ZHENG ; Deyu LI ; Yi ZHENG
Journal of Biomedical Engineering 2001;18(1):133-137
The methods, present research situation, existing problems, and application foreground of multidimensional reconstruction of ultras onic heart images are discussed in the present paper. According to the procedure of multidimensional reconstruction of ultrasonic heart images, the discussions are presented in respect toimage acquisition, processing, and display. Based on the present situation and existing problems, the future development and applica tion foreground are proposed.
2.Automatic Segmentation of Echocardiography Based on a Morphological Reconstruction Algorithm
Xianhua SHEN ; Deyu LI ; Jiangli LIN ; Tianfu WANG ; Xiaohui WEN ; Changqiong ZHENG ; Li RAO ; Hong TANG
Space Medicine & Medical Engineering 2005;18(4):246-250
Objective To improve the precision of the traditional segmentation of echocardiogram, by suppressing the influence from inherent speckle noises in medical ultrasonic images. Method An automatic segmentation method based on reconstructed morphology was proposed in this paper. First, the opening and closing operations by reconstruction were imposed to the ultrasonic image. Second, the top-hat operation was used to extract the bright and/or dark features and to find out the boundaries corresponding to these features, whereby implemented the automatic segmentation. Result The segmented echocardiogram had less artificial boundaries resulted from speckle noise, and could accurately be extracted the artery and ventricle. Conclusion The presented method can detect both dark and bright objects accurately, and the boundary has a fine continuity. In addition, the algorithm is also applicable to the extraction of sole bright/dark features, accordingly to reduce the complexity and time needed and to improve the accuracy.
3.Review of Filtering Algorithms for Medical Ultrasonic Images
Shukui ZHAO ; Deyu LI ; Tianfu WANG ; Changqiong ZHENG ; Yi ZHENG
Journal of Biomedical Engineering 2001;18(1):145-148
Several kinds of filters for medical ultrasonic images, suchas multidimensional filter, adaptive weighted filter (for example, adaptive weighted median filter), adaptive window selecting filter (for example , homogeneous region growing mean filter and adaptive speckle suppression filter ) and two-step filter, are introduced. The existing problems and the progress trend are also discussed. Some application instances for medical ultrasonic images of the filters discussed and the performance of the filters presented are based on the present authors' practice.
4.Auto-detection of Contour in Echocardiographic Images Based on Active Contour Model
Aijun HE ; Tianfu WANG ; Changqiong ZHENG ; Deyu LI ; Shukui ZHAO ; Yi ZHENG
Journal of Biomedical Engineering 2001;18(2):242-246,253
Contour detection is one of the most difficult problems in the multi-dimensional reconstruction of echocardiographic images. A method based on active contour model is presented in the present paper to solve this problem. First, according to the characteristic of the ultrasonic medical images, an adaptive weighted median filter is used to suppress speckle noise and an adaptive threshold value is selected to get binary image. Then, mathematical morphological treatment is utilized to get the initial contour. At last, active contour model is employed to revise the initial contour and get the accurate final contour. Experiments with real and interpolated ultrasonic images are presented. The results show the effectiveness of this method. This method has practical use in the multi-dimensional reconstruction of ultrasonic medical images.
5.Effects of the variation in components of DLC on protein adsorption.
Bogang LI ; Yunqing KANG ; Guangfu YIN ; Changqiong ZHENG
Journal of Biomedical Engineering 2004;21(2):193-195
Diamond-like carbon(DLC) was prepared by means of plasma source ion implantation-ion beam enhanced deposition. Through the heat treatment upon DLC in air and in depressed Ar gas, the DLC rich in graphite, DLC rich in diamond, and other kinds of DLC used in the study were obtained respectively. For the three kinds of DLC, the components of carbonaceous phase were analysed by X-ray photoelectron spectroscopy (XPS), the adsorptive amounts of human serum albumin (HSA), human serum fibrinogen (HFG) and human serum immunoglobin (IgG) on their surfaces in the condition of constant temperature were determined by radio isotope 125I labelling method. Results showed the graphite phase and diamond phase in DLC increased by two times or so respectively after the aforementioned different heat treatment. In pace with the increase of these foreign phases, the adsorptive amounts of HFG and IgG on DLC greatly increase but the adsorptive amounts of HSA on DLC decrease; furthermore, there is a change from non-selective adsorption of three human serum proteins into selective adsorptions of HFG and IgG prior to HSA. These results indicate that the foreign phases in DLC such as graphite, diamond, C-H phase and C-O phase have a great effect on protein adsorption on DLC and hence a negative effect on the hemocompatibility of DLC. The mechanisms for the increase of graphite phase and diamond phase in the process of heat treatment were also discussed in this paper.
Adsorption
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Biocompatible Materials
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chemistry
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Carbon
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chemistry
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Diamond
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chemistry
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Fibrinogen
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metabolism
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Humans
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Immunoglobulin G
;
metabolism
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Proteins
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metabolism
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Serum Albumin
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metabolism
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Surface Properties
6.Probe into the platelets adhesion to carbonaceous biomaterials.
Bogang LI ; Juanjuan NA ; Guangfu YIN ; Jie YIN ; Changqiong ZHENG
Journal of Biomedical Engineering 2004;21(1):12-15
In order to clarify the mechanism of blood coagulation for carbonaceous biomaterials, the plasma rich in platelet was obtaining through the centrifugation of fresh human blood containing anticoagulant. Adhesive tests of platelets to surfaces of DLC, diamond film(DF) and graphite was carried out at 37 degrees C. Then, morphology observation, counting and deformation index calculation of the platelets adhering to surfaces of the three kinds of materials were analyzed by SEM. It has been shown that there is no any platelet on the surface of DLC, but on DF and graphite, a lot of platelets are observed with serious deformation of type III-V. The adhesive amounts of platelet on the surface of graphite are more than those on DF, but deformation index of platelets on the surface of DF is more than that on graphite. Three major conclusions have been obtained through comparative analyses with our previous researches and related literatures: (1) Adhesion, deformation and collection of platelets occurred in succession on material surfaces resulting from protein adsorption are the major mechanism of blood coagulation of carbonaceous materials; (2) Deformation degree of platelets is more important hemocompatibility index than consumption ratio of platelets for carbonaceous materials; (3) The purer the DLC, the better is the hemocompatibility. These conclusions possess important directive function for improving and designing carbonaceous materials used in artificial mechanical heart valves.
Biocompatible Materials
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Blood Platelets
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pathology
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Carbon
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Diamond
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Graphite
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Humans
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In Vitro Techniques
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Materials Testing
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Platelet Adhesiveness
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Surface Properties
7.A review of interpolation in multi-dimensional reconstruction of medical images.
Liu YANG ; Deyu LI ; Aijun HE ; Long WANG ; Tianfu WANG ; Changqiong ZHENG
Journal of Biomedical Engineering 2003;20(4):728-737
Image interpolation techniques were widely applied in medical imaging for image generation and post processing. Firstly, traditional interpolation methods were listed out in the details of shape-based interpolation and dynamic elastic registration interpolation. Secondly, the characteristics, development and problems in interpolation of rotary scanning ultrasonic cardiac images were analyzed. The relation between interpolation and registration was stated. The analysis indicated that excellent methods in rotary scanning interpolation should be registration-based methods. At last, several evaluation methods about images interpolation were discussed.
Algorithms
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Echocardiography, Three-Dimensional
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methods
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Fourier Analysis
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Image Processing, Computer-Assisted
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methods
8.Computer-aided diagnosis of fatty liver based on ultrasonic images.
Xiaoyi WANG ; Jiangli LIN ; Deyu LI ; Tianfu WANG ; Changqiong ZHENG ; Yinrong CHENG
Journal of Biomedical Engineering 2006;23(4):726-729
This study aims to provide a computer-aided method for the diagnosis of fatty liver by B-scan ultrasonic imaging. Fatty liver is referred to the infiltration of triglycerides and other fats of the liver cells, which affected the texture of liver tissue. In this paper, some features including mean intensity ratio, as well as angular second moment, entropy and inverse differential moment of gray level co-occurrence matrix were extracted from B-scan ultrasonic liver images. Feature vectors which indicated two classes of images were created with the four features. Then we used kappa-means clustering algorithm, self-organized feature mapping (SOFM) artificial neural network and back-propagation (BP) artificial neural network to classify these vectors. The accuracy rate of kappa-means clustering algorithm was 100% for normal liver and 63.6% for fatty liver. The results of SOFM neural network showed that the accuracy rate was 84.8% for normal liver and 90.9% for fatty liver. The accuracy rate of neural network was 100% both for normal liver and fatty liver. This technology could detect the characteristics of B-scan images of normal liver and fatty liver more accurately. It could greatly improve the accuracy of the diagnosis of fatty liver.
Diagnosis, Differential
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Fatty Liver
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diagnostic imaging
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Humans
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Image Processing, Computer-Assisted
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methods
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Lung
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diagnostic imaging
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Neural Networks (Computer)
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Sensitivity and Specificity
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Ultrasonography
9.Design and development of the multi-dimensional ultrasonic reconstruction and visualization system.
Liu YANG ; Minghao PENG ; Li RAO ; Kai MAO ; Changqiong ZHENG
Journal of Biomedical Engineering 2009;26(4):878-882
The design and development of multi-dimensional ultrasonic reconstruction and visualization system (MURVS) have been described in the present paper. This system is basically composed of four modules: the data input/output module, image segmentation and arrangement module, multi-dimensional reconstruction module, and the dynamic visualization module. At first, some algorithms used in the system are introduced by the authors, including the AVI segmentation algorithm, three-dimensional interpolation algorithm, and volume rendering algorithms. Then the key questions of techniques to be discussed are: how to design the main modules, how to solve the dynamic visualization problem, and how to implement the system. The experiments indicate that MURVS is able to reconstruct all three-dimensional data fields in one cardiac cycle of a patient within 4 seconds, and dynamically display the motion of the heart. It allows the medical professionals to select different parameters when observing the reconstructed results. This is very helpful for medical professionals to reach more accurate diagnoses of their patients' diseases.
Adult
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Algorithms
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Echocardiography, Three-Dimensional
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methods
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Female
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Humans
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Image Processing, Computer-Assisted
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methods
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Mitral Valve Stenosis
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diagnostic imaging
10.Energy mechanism of effects of carbon phase components on hemocompatibility for DLC.
Bogang LI ; Ming XUE ; Guangfu YIN ; Jie YIN ; Changqiong ZHENG
Journal of Biomedical Engineering 2005;22(2):235-237
The correlations between surface energy parameters and carbon phase components in six diamond like carbon film (DLC) samples made in different ways and processing conditions were further investigated using the analysis of T-type correlation degree in the Grey system theory based on our earlier studies such as the determination of carbon phase and surface energy parameters, the analyses of carbon phase components, surface energy parameters and adhesive characteristic of platelets for DLC. The results showed: (1) as a whole critical surface tension has the closest relation with carbon phase components, chromatic dispersion branch of surface tension takes the second place, but for the other four parameters, the correlation is weak; (2) DLC phase has larger negative correlation (degrees -0.57, -0.33) with critical surface tension and chromatic dispersion branch of surface tension, while its correlation degrees with the other four parameters related to polarity are all positive values smaller than 0.20; (3) C-H phase and C-O phase have larger positive correlation (degrees 0.48, 0.25) with critical surface tension. We have come to three conclusions (1) DLC phase plays a dominant part in hemocompatibilioty of DLC by powerfully decreasing humidification and limitedly increasing polarity; (2) the energy mechanism of platelet deformation enhanced by C-H phase and C-O phase involves increasing the critical surface tension of DLC; (3) the hemocompatibility of DLC can be evaluated by using the critical surface tension as index and using the content of DLC phase and additional content limitation of C-H phase and C-O phase as standard. This study has provided a theoretical basis for evaluating the hemocompatibility of DLC based on surface properties.
Biocompatible Materials
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chemistry
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Carbon
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chemistry
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Diamond
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chemistry
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Humans
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Male
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Materials Testing
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Membranes, Artificial
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Models, Biological
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Platelet Adhesiveness
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drug effects
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Surface Properties