Hemodynamics-simulation-based cardiovascular surgical planning.which is the patient-specific surgical hemodynamics optimization based on medical image,is the further development of clinical-applica-tion-oriented computational hemodynamics,it is very helpful for cardiovascular surgical decision-making.The art-in-work of hemodynamics-simulation-based cardiovascular surgical planning in both domestic and over-seas research was reviewed,the key problems and solutions involved were analyzed,and the further develo-ping objectives were presented.

Hemodynamics-simulation-based cardiovascular surgical planning.which is the patient-specific surgical hemodynamics optimization based on medical image,is the further development of clinical-applica-tion-oriented computational hemodynamics,it is very helpful for cardiovascular surgical decision-making.The art-in-work of hemodynamics-simulation-based cardiovascular surgical planning in both domestic and over-seas research was reviewed,the key problems and solutions involved were analyzed,and the further develo-ping objectives were presented.

Objective To detect the blood viscosity values and find out the statistically significant influencing factors of blood viscosity and their fitting formulas among the middle aged and elderly people with high incidence of cardiovascular diseases. Methods The subjects’ blood was collected in the hospital, together with their physiological and pathological information, and LG-R-80 series rotary viscometer detector was used to detect blood viscosity. The statistically significant factors of blood viscosity and their fitting formulas were obtained by using SPSS. Results Blood viscosity increased with age and body mass index (BMI) and reached its peak value in 60 year-old males (5.35 mPa•s) and 50 year-old females (4.45 mPa•s), respectively, then the variation of blood viscosity would be stabilized, with no more increase; the blood viscosity values of males in all groups with different ages were significantly higher than those of females, with difference value in the range of 0.28-0.90 mPa•s; the blood viscosity values were obviously higher in hypertension group than those in normal group, with statistically significant differences (P<0.1). Conclusions The blood viscosity distribution in people with high incidence of cardiovascular diseases has certain regular pattern, and the obtained fitting formula between blood viscosity and influencing factors in this study would provide useful references for further study such as variation of blood viscosity under different physiological conditions, effects of different viscosities on some cardiovascular diseases, and non-invasive detection of blood viscosities.

Hemodynamics is closely related with the initiation, development and treatment of neo-cardiovascular diseases. The studies on the hemodynamics in neo-cardiovascular system are the hotspots of biomechanics and biomedical engineering. The research topics, research method, research achievement and its medical application, which are issued in the articles in this special column, were remarked. Emphasis was paid to the review of the research driver, research progress and research tendency of hemodynamics. The application prospect of hemodynamics research on the clinical procedure and healthcare was demonstrated with respect to its multi level application in prevention, diagnosis and treatment.

Objective To optimize the baseline on the trapezoidal cross section of stent wires, so as to reduce the risk of intracranial saccular aneurysm rupture after the implantation of such stents. Methods Thirty-eight trapezoidal cross-section wire stents with different baselines were constructed to establish the finite element models. Numerical simulation by fluid-solid interaction method was conducted to calculate 38 maximum pressure gradients on the aneurysm wall. GRNN (general regression neural network) and GA (genetic algorithm) were used to optimize the baseline on the cross-section of stents with trapezoidal cross-section wire so as to minimize the maximal pressure gradient on the aneurysm wall. Results Compared with the traditional stent with rectangular cross-section wire, the maximal pressure gradient on the a neurysm wall was reduced by 7.86% after the implantation with the optimized stent with trapezoidal cross-section wire. Conclusions The combination of GRNN and GA is an effective approach for stent optimization.

Objective To propose and numerically simulate a novel stent with triangular wire cross-section so as to compare the hemodynamic effect of endovascular stents in aneurysm with circular, rectangular and triangular cross section, respectively. Methods Three aneurysm models were constructed by implanting 3 kinds of stents separately, including one with bare circular wire cross-section stent (named CM), and one with bare rectangular wire cross-section stent (named RM), and one with bare triangular cross-section stent (named TM). An unstented aneurysm model was also constructed to serve as the control (named UM). Four models were preformed with numerical simulation of fluid-structure interaction under the same boundary conditions using finite element method. Results Compared with TM and CM, RM showed lower velocity, higher flow resistance and longer turn over time, which demonstrated that the effect of blood flow pattern on three stents was decreased in the order of RM, TM, CM. RM could reduce the magnitude and fluctuation of wall shear stress (WSS) more significantly than that of TM and CM. However, the pressure rise of TM and CM was lower than that of RM. WSS distribution and deformation results indicated the possibility of aneurysm development along the distal wall was higher than that along the proximal wall, and the top of aneurysm was in the highest risk of rupture. Conclusions Three kinds of stents show differences of hemodynamics in aneurysm treatment, which provides significant references for the structural design and optimization of endovascular stent.

Objective To investigate the mechanical mechanism of bypass graft for the treatment of DeBakey III aortic dissection and explore the valid surgical planning. Methods Patient-specific models of DeBakey III aortic dissection, including the models of through lumen and blind lumen, before and after bypassing between ascending aorta and abdominal aorta, between left subclavian artery and abdominal aorta, were constructed, and then numerical simulations were performed using computational fluid dynamics (CFD) method under physiological flow conditions based on fluid-structure interaction (FSI). Results Blood flow velocity, pressure, vessel wall displacement of the false lumen after bypass graft were reduced by 38.86%, 15.347 kPa and 39.46% on average, respectively. Conclusions Bypass graft is an effective surgical method for the treatment of DeBakey III aortic dissection under specific conditions with good prospects in clinical application.

In recent years, computational fluid dynamics (CFD) has been widely used in fundamental and clinical researches of cerebral aneurysms. The research direction involves: ① the hemodynamic risk factors associated with initiation, evolution and rupture of cerebral aneurysms, ② the assessment of flow field changes in cerebral aneurysms after the implantation of coils and stent as well as the effect of such endovascular treatment by establishing the patient-specific models. This review elaborates the research progress in hemodynamics of cerebral aneurysms from 3 aspects: the development of CFD models, the morphological and hemodynamic parameters for rupture risk assessment of aneurysms and the role of CFD in the endovascular treatment of cerebral aneurysms.

The rupture of carotid atherosclerotic plaques and thrombosis are the main risk factor for ischemic stroke. The risk of carotid plaque rupture is closely related with the local biomechanical situation, morphology, components and biological activity of the carotid plaques. In this article, the research progress on methodology for studying carotid stenosis biomechanics, the risk of vulnerable plaque rupture in carotid stenosis and decision-making in clinical treatment, the animal modeling and experiment on vulnerable carotid plaques, and the components and biological activities of carotid plaques was summarized, the existing problems were analyzed, and the in-depth prospective about the biomechanical mechanism and quantitative assessment indices for vulnerable carotid plaques was also proposed, expecting to provide necessary theoretical guidance for feasible decision-making on the treatment of carotid stenosis.

An automatic inspection system for biochip's print quality is presented in this paper. It consists of an automatic mechanical control, a CCD sensor for getting the image of PET boart, and the special computer software for image processing and recognition. Experimental results indicate that this system is capable of providing a precise and effective realtime inspection for biochips' print quality.
Biosensing Techniques ; instrumentation ; methods ; Equipment Design ; Image Processing, Computer-Assisted ; methods ; Microchip Analytical Procedures ; methods ; Pattern Recognition, Automated ; methods ; Quality Control ; Software