1.Application of bump texture mapping in block mapping.
Jie ZHANG ; Bin CHENG ; Xiaoming WANG ; Jingtao ZHOU
Journal of Biomedical Engineering 2014;31(4):899-904
With the progresses of the research on "Digital Human", more and more information has been needed for the setting up of the three-dimensional digital models of human organs. In the present paper, based on the method of block mapping with a normal-style bump mapping method, we normalized the vector of the surface of the models, computed offset of the texture coordinates and added to them. The projection of the coordinates to the tangential space complemented the disturbance to the vector of models' surface. The method was proposed with bump texture mapping on the surface of the biological models of organs to improve the impression of the visualization of the organ models and to enhance the sense of reality of the models.
Humans
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Models, Anatomic
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Models, Biological
2.Research status and trend of heart modeling.
Chinese Journal of Medical Instrumentation 2011;35(1):58-63
It is significant to research the heart modeling for the diagnosis and treatment of heart disease. With the development of biomedical technology, material and computer science, there are new requirements for heart modeling and simulation in terms of heart data acquisition, modeling approach, clinical application and so on. The research status of heart geometric/anatomical model, heart electrophysiological model and mechanical dynamic model has been summarized in this paper, and the problems and trends of heart modeling have been analyzed synthetically.
Heart
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Models, Biological
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Research Design
3.Pathophysiology of Craniocerebral Trauma.
Journal of Korean Neurosurgical Society 1993;22(7):809-814
In the past decade, major advances have been made in defining and, to some extent, quantifying the types of brain damage that occur in non-missile head injury, and in identifying their pathogenesis, using biological models of head injury. There have been various approaches to the classification of brain damage and we have tended to emphasize the existence of primary and secondary damage from impairment of cerebral blood flow and brain metabolism, which helps in the identification of at least potentially preventable complications.
Brain
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Classification
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Craniocerebral Trauma*
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Metabolism
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Models, Biological
4.Research of Feedback Algorithm and Deformable Model Based on Improved Spring-mass Model.
Weidong CHEN ; Panpan CHEN ; Qiguang ZHU
Journal of Biomedical Engineering 2015;32(5):989-996
A new diamond-based variable spring-mass model has been proposed in this study. It can realize the deformation simulation for different organs by changing the length of the springs, spring coefficient and initial angle. The virtual spring joined in the model is used to provide constraint and to avoid hyperelastic phenomenon when excessive force appears. It is also used for the calculation of force feedback in the deformation process. With the deformation force feedback algorithm, we calculated the deformation area of each layer through screening effective particles, and contacted the deformation area with the force. This simplified the force feedback algorithm of traditional spring-particle model. The deformation simulation was realized by the PHANTOM haptic interaction devices based on this model. The experimental results showed that the model had the advantage of simple structure and of being easy to implement. The deformation force feedback algorithm reduces the number of the deformation calculation, improves the real-time deformation and has a more realistic deformation effect.
Algorithms
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Computer Simulation
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Feedback
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Models, Biological
5.A prediction model of MF radiation in environmental assessment.
Biomedical and Environmental Sciences 2006;19(5):405-408
OBJECTIVETo predict the impact of MF radiation on human health.
METHODSThe vertical distribution of field intensity was estimated by analogism on the basis of measured values from simulation measurement.
RESULTSA kind of analogism on the basis of geometric proportion decay pattern is put forward in the essay. It showed that with increasing of height the field intensity increased according to geometric proportion law.
CONCLUSIONThis geometric proportion prediction model can be used to estimate the impact of MF radiation on inhabited environment, and can act as a reference pattern in predicting the environmental impact level of MF radiation.
Electromagnetic Phenomena ; Environment ; Models, Biological ; Radiation
6.A dynamics model describing edema and its physiological analysis.
Wei YAO ; Guanghong DING ; Xueyong SHEN ; Jianhua DAI ; Ke CHENG ; Er'yu CHEN ; Ruishang DANG ; Hu WEI
Journal of Biomedical Engineering 2005;22(1):15-19
Edema is a common pathological symptom, but its development mechanism is unknown. Based on the bearings of pressure upon interstitium structure and substantial exchange between plasma and interstitial fluid, a dymamics model describing the development of edema was set up. The model's theoretical results showed that the variations of interstitium pressure and structure due to imbalance of substantial exchange may lead to the development of edema, which is in accordance with recent clinical researches. Discussions on the dynamic mechanism of the development of edema proposed that the best way to prevent edema is instituting treatment before the interstitial structure being destroyed.
Edema
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physiopathology
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Humans
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Models, Biological
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Nonlinear Dynamics
7.Research on modeling and simulation of the system of position transformation mechanical ventilation.
Ji-ping XU ; Zai-wen LIU ; Xiao-yi WANG
Chinese Journal of Medical Instrumentation 2009;33(6):402-406
The principle of Position Transformation Mechanical Ventilation (PTMV) was introduced briefly, and the mechanical structure and the intelligent control algorithm were studied. According to the principle and function requirement of PTMV, the mechanical structure of slip pole driven rocking chair(SPDRC) was proposed, the dynamics model of SPDRC was established, and the auto disturbance rejection controller was designed. The integrated model of control system was structured by using ADAMS and MATLAB, and the model validation and simulation were implemented. The simulation results indicate that the mechanical structure is feasible and the control process of ADRC is precise and steady.
Algorithms
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Models, Biological
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Posture
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Respiration, Artificial
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methods
8.Study of population pharmacokinetic model and parameter analyses for multiple components in Chinese matria medica formula.
Fuyuan HE ; Kaiwen DENG ; Wenglong LIU ; Jilian SHI ; Yantao YANG
China Journal of Chinese Materia Medica 2011;36(20):2866-2870
OBJECTIVETo eluciate and establish a new population pharmacokinetic mathematical models and parameter calculation for the multiple components in the Chinese Matria Medica Formula (CMMF) through analyses of population pharmacokinetic parameter calculation for single compounds.
METHODThe model was been set up by statistic moment principle to form a new population pharmacokinetics for the mutiple components in CMMF according to the single compound population pharmacokinetic parameter calculation principle.
RESULTIt have been established the mathematical model for the population pharmacokinetic model for CMMF that consisted of a series of parameters: 1) total quantum zero moment as AUC(T), 2) first moment as MRT(T), mean residence time of metabolism, 3) second moment as VRT(T), variance of mean residence time of metabolism, 4) total body clearance CL(T), 5) total apparent volum V(T), 6) 95% of total ingredient metabolic time interval PI(T)(0.95), 7) 95% of total ingredient accumulation metabolic time interval Pa(T)(0.95) etc that were correlated with single population pharmacokinetic parameters.
CONCLUSIONThe population pharmacokinetic model and parameter calculation for CMMF can be established on the bases of single compound population pharmacokinetics by way of total quantum statistic moment principle to be expansived taylor expression at point of population parameter typical values to divide population pharmacokinetic total quantum statistical moment parameters into the four term of typical value, fixed effect, biologic variation and experiment error.
Humans ; Medicine, Chinese Traditional ; Models, Biological ; Pharmacokinetics
9.Pharmacodynamic principles and the time course of delayed and cumulative drug effects
Translational and Clinical Pharmacology 2018;26(2):56-59
This tutorial reviews the principles of the concentration — effect relationship for the usual case when drug effects are delayed relative to changes in circulating concentrations. The key processes determining delay are distribution from the circulation to the receptor, binding to the receptor to produce a stimulus and translation of the receptor stimulus into an effect through turnover of physiological mediators. Some clinical outcomes are dependent on the accumulation of drug action which is predictable in terms of basic pharmacokinetic and pharmacodynamic concepts.
Dose-Response Relationship, Drug
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Models, Biological
10.Continued surprises in the cytochrome c biogenesis story.
Elizabeth B SAWYER ; Paul D BARKER
Protein & Cell 2012;3(6):405-409
Cytochromes c covalently bind their heme prosthetic groups through thioether bonds between the vinyl groups of the heme and the thiols of a CXXCH motif within the protein. In Gram-negative bacteria, this process is catalyzed by the Ccm (cytochrome c maturation) proteins, also called System I. The Ccm proteins are found in the bacterial inner membrane, but some (CcmE, CcmG, CcmH, and CcmI) also have soluble functional domains on the periplasmic face of the membrane. Elucidation of the mechanisms involved in the transport and relay of heme and the apocytochrome from the bacterial cytosol into the periplasm, and their subsequent reaction, has proved challenging due to the fact that most of the proteins involved are membrane-associated, but recent progress in understanding some key components has thrown up some surprises. In this Review, we discuss advances in our understanding of this process arising from a substrate's point of view and from recent structural information about individual components.
Cytochromes c
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chemistry
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metabolism
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Models, Biological