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Journal of Geriatric Cardiology 2024年第3期21卷 251-314页

作者： Chang-Sheng MA Shu-Lin WU Shao-Wen LIU Ya-Ling HAN Chinese Society of Cardiology Chinese Medical Association Heart Rhythm Committee of Chinese Society of biomedical engineering Beijing Anzhen Hospital Capital Medical University Guandong Provincial People’s Hospital Shanghai First People’s Hospital General Hospital of Northern Theater Command 不详

Atrial fibrillation(AF)is the most common sustained cardiac arrhythmia,significantly impacting patients’quality of life and increasing the risk of death,stroke,heart failure,and *** the past two decades,there have been significant breakthroughs in AF risk prediction and screening,stroke prevention,rhythm control,catheter ablation,and integrated *** this period,the scale,quality,and experience of AF management in china have greatly improved,providing a solid foundation for the development of guidelines for the diagnosis and management of *** further promote standardized AF management,and apply new technologies and concepts to clinical practice in a timely and comprehensive manner,the Chinese Society of Cardiology of the Chinese Medical Association and the Heart Rhythm Committee of the Chinese Society of biomedical engineering have jointly developed the Chinese Guidelines for the Diagnosis and Management of Atrial *** guidelines have comprehensively elaborated on various aspects of AF management and proposed the CHA2DS2-VASc-60 stroke risk score based on the characteristics of AF in the Asian *** guidelines have also reevaluated the clinical application of AF screening,emphasized the significance of early rhythm control,and highlighted the central role of catheter ablation in rhythm control.

关键词： prevention sustained diagnosis

Preparation and Characterization of Collagen-GAGs Bioactive Matrices for Tissue engineering

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Journal of Materials Science & Technology 2001年第5期17卷 495-500页

作者： Hongyi YANG and Qiqing ZHANG institute of biomedical engineering, Chinese Academy of Medical Science, Tianjin 300192, china Chinese Acad Med Sci Inst Biomed Engn Tianjin 300192 Peoples R China

Collagen materials were crosslinked by 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) in the presence of chondroitin sulfate (CS), one of glycosaminoglycans (GAGS). PVA and chitosan were also blended with collagen. The physical and chemical properties of the matrices were characterized by SEM, DSC, and ESCA. L929 cells were implanted on the matrices to show the cytotoxic and the biological characters of the materials. The results indicate that EDC is an effective and non-cytotoxic cross-link reagent, which can replace the common dialdehyde reagent. The attachment of CS can improve the stability of collagen and accelerate cell growth. The addition of PVA can prepare porous matrices with smaller bore size. There are reactions between the chitosan and collagen, and the composite has good biological character. The presence of chitosan can also increase the amount of incorporated CS.

关键词： Preparation and Characterization of Collagen-GAGs Bioactive Matrices for Tissue engineering PVA EDC CS

Electric-stimulus rate encoding algorithm of Mandarin tonal information in cochlear implant

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Progress in Natural Science:Materials International 2006年第12期16卷 1315-1321页

作者： GUAN Tian~1, GONG Qin~1 and YE Datian~2**(1. Department of biomedical engineering, Tsinghua University, Beijing 100084, china 2. Research Center of biomedical engineering, Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055, china) [a]Department of biomedical engineering Tsinghua University Beijing China [b]Research Center of biomedical engineering Graduate School at Shenzhen Tsinghua University Shenzhen China

The modern multi-channel cochlear implants usually extract and encode the temporal envelope cues. This kind of algorithms can hardly satisfy the users who speak tonal languages, such as Mandarin. Many studies have tried to enhance the recognition ability of Mandarin through encoding tonal information and made suggestions to frequency-modulate the fixed pulse-rate carrier with the extracted tonal information based on the rate-pitch theory in electric hearing. However, how to encode and deliver the tonal information such as F_0by changing electric-stimulus rate has not got further study in clinical electric-stimulus mode. The present paper focuses on this matter by piecewise calculating the appreciable electric-stimulus rates. Then an electric-stimulus encoding algorithm of Mandarin tone is brought forward and testified through acoustic simulations. Such conclusion can be drawn that this algorithm of electric-stimulus rate could convey tonal information well and help to enhance the Mandarin speech recognition ability.

关键词： cochlear implant tone fundamental frequency electric-stimulus rate.

A study on compressive shock wave propagation in metallic foams

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Science china(Physics,Mechanics & Astronomy) 2010年第2期53卷 279-287页

作者： WANG ZhiHua1,2,ZHANG YiFen2,REN HuiLan1 & ZHAO LongMao2 1 State Key Laboratory of Explosion Science and Technology,Beijing institute of Technology,Beijing 100081,china 2.institute of Applied Mechanics and biomedical engineering,Taiyuan University of Technology,Taiyuan 030024,china 1. State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing 100081 China2. Institute of Applied Mechanics and Biomedical Engineering Taiyuan University of Technology Taiyuan 030024 China

Metallic foam can dissipate a large amount of energy due to its relatively long stress plateau,which makes it widely applicable in the design of structural crashworthiness. However,in some experimental studies,stress enhancement has been observed when the specimens are subjected to intense impact loads,leading to severe damage to the objects being protected. This paper studies this phenomenon on a 2D mass-spring-bar model. With the model,a constitutive relationship of metal foam and corresponding loading and unloading criteria are presented; a nonlinear kinematics equilibrium equation is derived,where an explicit integra-tion algorithm is used to calculate the characteristic of the compressive shock wave propagation within the metallic foam; the effect of heterogeneous distribution of foam microstructures on the shock wave features is also included. The results reveal that under low impact pulses,considerable energy is dissipated during the progressive collapse of foam cells,which then reduces the crush of objects. When the pulse is sufficiently high,on the other hand,stress enhancement may take place,especially in the heterogeneous foams,where high peak stresses usually occur. The characteristics of compressive shock wave propagation in the foam and the magnitude and location of the peak stress produced are strongly dependent on the mechanical properties of the foam material,amplitude and period of the pulse,as well as the homogeneity of the microstructures. This research provides valuable insight into the reliability of the metallic foams used as a protective structure.

关键词： aluminum foam heterogeneous intensive pulse loading stress enhancement

The effects of the false vocal fold gaps on intralaryngeal pressure distributions and their effects on phonation

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Science china(Life Sciences) 2008年第11期51卷 1045-1051页

作者： LI Sheng1,2, WAN MingXi1 & WANG SuPin1 1 Key Laboratory of biomedical Information engineering of Ministry of Education, Department of biomedical engineering, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an 710049, china 2 Department of biomedical engineering, Fourth Military Medical University, Xi’an 710032, china 1. Key Laboratory of biomedical Information engineering of Ministry of Education Department of Biomedical Engineering School of Life Science and Technology Xi’an Jiaotong University Xi’an 710049 China 2. Department of biomedical engineering Fourth Military Medical University Xi’an 710032 China

Human phonation does not merely depend on the vibration of the vocal folds. Research by clinical and computer simulations has demonstrated that the false vocal fold (FVF) is an important laryngeal con-striction that plays a vital role during human voice production. This study explored the effects of the FVF gaps using both the three-dimensional Plexiglas model and the numerical computation methods. Twelve FVF gaps (ranging from 0.02 to 2.06 cm) were used in this study at three glottal angles (uniform and convergent/divergent 40°), two minimal glottal diameters (Dg) (0.04 cm and 0.06 cm) separately, and the constant subglottal pressure (8 cm H2O). The results suggested that (1) the intralaryngeal pressure was the lowest and the flow was the highest (least flow resistance) when the FVF gap was 1.5-2 times greater than Dg; (2) the divergent glottal angle gave lower pressure and greater flow than the conver-gent and uniform glottal angle as there were no FVF conditions; (3) the presence of the FVF decreased the effects of the glottal angle to a certain extent; and more importantly, (4) the presence of the FVF also moved the separation points downstream, straightened the glottal jet for a longer distance, decreased the overall laryngeal resistance, and reduced the energy dissipation, suggesting the significance of FVF in efficient voice production. These results may be incorporated in the phonatory models (physical or computational) for better understanding of vocal mechanics. The results might also be helpful in exploring the surgical and rehabilitative intervention of related voice problems.

关键词： false vocal fold laryngeal physical model aerodynamics modeling phonation

Positive Effect of Noises on Sensory Systems

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Journal of Bionic engineering 2004年第1期1卷 61-65页

作者： Jun Liu, Guang Li institute of biomedical engineering and instrument Science, Zhejiang University, Hangzhou 310027,P.R.china Zhejiang University Zhejiang University

Stochastic resonance phenomenon in the biological sensory systems has been studied through the signal detection theories and the psychophysical experiments. In this paper, sensory systems are considered as a threshold detector including the receiver part and the classifier part. Compared with conventional models regarding the receiver part of sensory system as a linear or single non-linear system, a summing network was constructed by MacCulloch-Pitts neurons to simulate the receiver part. The simulation results show that the relevant index of the detectability of signal exhibit the stochastic resonance behaviours. The psychophysical experiments were carried out through the 2IFC (two interval two alternative forced choice) method. The experimental results qualitatively verify the conclusion in accordance with the theoretical model. These works give a proof that stochastic resonance is not only epiphenonmenon in sensory systems.

关键词： stochastic resonance signal detection theory psychophysical experiment MacCulloch-Pitts neuron

Numerical and experimental investigation of the fracture behavior of shock loaded alumina

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Science china(Physics,Mechanics & Astronomy) 2010年第2期53卷 244-252页

作者： REN HuiLan1,SHU XueFeng2 & LI Ping3 1 State Key Laboratory of Explosion Science and Technology,Beijing institute of Technology,Beijing 100081,china 2.institute of Applied Mechanics and biomedical engineering,Taiyuan University of Technology,Taiyuan 030024,china 3 Labroratory for Shock Wave and Detonation Physics Research,institute of Fluid Physics,CAEP,Mianyang 610059,china 1. State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing 100081 China2. Institute of Applied Mechanics and Biomedical Engineering Taiyuan University of Technology Taiyuan 030024 China3. Labroratory for Shock Wave and Detonation Physics Research Institute of Fluid Physics CAEP Mianyang 610059 China

Plate impact expeiments are conducted to investigate the dynamic behavior of alumina by using one stage light gas gun. A ve-locity interferometer system for reflectors (VISAR) is used to obtain Hugoniot elastic limit and the free surface velocity profile,which consists of an elastic wave followed immediately by a dispersive inelastic wave. The stress histories under different impact velocities are measured by in-material manganin gauges. Based on the experimental data a Hugoniot curve is fitted,which shows the compressive characteristics that alumina changes typically from elastic to "plastic" ,and under higher pressure it will be transferred to similar-fluid state. The turning point of the Hugoniot curve from a high pressure region to a low pressure region is about 11.4 GPa. The fracture process of alumina is simulated by way of finite element code. After the analysis of the fracture mechanism,the numerical results show an important role played by the nucleation and the growth of the cracks in the macro-scopic fracture of the alumina target. The numerical predictions of stress histories are compared with the experimental results,which indicates consistency between them.

关键词： plate impact experiment hugoniot curve fracture characteristics numerical simulation

Parameter estimation for whole-body kinetic model of FDG metabolism

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Progress in Natural Science:Materials International 2006年第11期16卷 1164-1170页

作者： CUI Yunfeng~1, BAI Jing~1**, CHEN Yingmao~2 and TIAN Jiahe~2(1. Department of biomedical engineering, Tsinghua University, Beijing 100084, china 2. Department of Nuclear Medicine, General Hospital of PLA, Beijing 100853, china) [a]Department of biomedical engineering Tsinghua University Beijing China [b]Department of Nuclear Medicine General Hospital of PLA Beijing China

Based on the radioactive tracer [ ~ 18 F]2-fluoro-2-deoxy-D-glucose （FDG）, positron emission tomography （PET）, and compartment model, the tracer kinetic study has become an important method to investigate the glucose metabolic kinetics in human body. In this work, the kinetic parameters of three-compartment and four-parameter model for the FDG metabolism in the tissues of myocardium, lung, liver, stomach, spleen, pancreas, and marrow were estimated through some dynamic FDG-PET experiments. Together with published brain and skeletal muscle parameters, a relatively complete whole-body model was presented. In the liver model, the dual blood supply from the hepatic artery and the portal vein to the liver was considered for parameter estimation, and the more accurate results were obtained using the dual-input rather than the single arterial-input. The established whole-body model provides the functional information of FDG metabolism in human body. It can be used to further investigate the glucose metabolism, and also be used for the simulation and visualization of FDG metabolic process in human body.

关键词： compartment model FDG PET parameter estimation.

Simulation study and function analysis of the dynamic aortic valve

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Progress in Natural Science:Materials International 2006年第5期16卷 512-517页

作者： XIA Dongdong and BAI Jing (Department of biomedical engineering, Tsinghua University, Beijing 100084, china) Department of biomedical engineering Tsinghua University Beijing 100084 China

The dynamic aortic valve (DAV) is a new left ventricular assist device, a micro-axial blood pump implemented at the position of the aortic valve, pumping blood from the left ventricle into the aortic artery. The present dynamic aortic valve operates at 7 different rotation speeds, ranging from 3000 r/min (speed 1) to 9000 r/min (speed 7). Because in vivo experiments need a lot of live animals and take a long period of time, modeling and simulation have been widely used to simulate and analyze hydra-dynamic property of the DAV and its assisting effects. With the measurements from the mock circulatory loop, a mathematic model of the DAV is established and embedded into the previously developed canine circulatory system. Using this model, the effect of the DAV on the failing heart at each rotation speed level is investigated. The vital cardiac variables are computed and compared with in vivo experimental results, which are in good agreement with an acceptable difference mostly 15%. The establishment of the DAV model and its simulation are useful for further improvement of the DAV device.

关键词： dynamic aortic valve mathematic model computer simulation.