Image matching based on scale invariant feature transform（SIFT） is one of the most popular image matching algorithms, which exhibits high robustness and accuracy. Grayscale images rather than color images are genera...Image matching based on scale invariant feature transform（SIFT） is one of the most popular image matching algorithms, which exhibits high robustness and accuracy. Grayscale images rather than color images are generally used to get SIFT descriptors in order to reduce the complexity. The regions which have a similar grayscale level but different hues tend to produce wrong matching results in this case. Therefore, the loss of color information may result in decreasing of matching ratio. An image matching algorithm based on SIFT is proposed, which adds a color offset and an exposure offset when converting color images to grayscale images in order to enhance the matching ratio. Experimental results show that the proposed algorithm can effectively differentiate the regions with different colors but the similar grayscale level, and increase the matching ratio of image matching based on SIFT. Furthermore, it does not introduce much complexity than the traditional SIFT.展开更多
Centrifugal blood pumps have become popular for adult extracorporeal membrane oxygenation(ECMO)due to their superior blood handling and reduced thrombosis risk featured by their secondary flow paths that avoid stagnan...Centrifugal blood pumps have become popular for adult extracorporeal membrane oxygenation(ECMO)due to their superior blood handling and reduced thrombosis risk featured by their secondary flow paths that avoid stagnant areas.However,the high rotational speed within a centrifugal blood pump can introduce high shear stress,causing a significant shear-induced hemolysis rate.The Revolution pump,the Rotaflow pump,and the CentriMag pump are three of the leading centrifugal blood pumps on the market.Although many experimental and computational studies have focused on evaluating the hydraulic and hemolytic performances of the Rotaflow and CentriMag pumps,there are few on the Revolution pump.Furthermore,a thorough direct comparison of these three pumps'flow characteristics and hemolysis is not available.In this study,we conducted a computational and experimental analysis to compare the hemolytic performances of the Revolution,Rotaflow,and CentriMag pumps operating under a clinically relevant condition,i.e.,the blood flow rate of 5 L/min and pump pressure head of 350 mmHg,for adult ECMO support.In silico simulations were used to characterize the shear stress distributions and predict the hemolysis index,while in vitro blood loop studies experimentally determined hemolysis performance.Comparative simulation results and experimental data demonstrated that the CentriMag pump caused the lowest hemolysis while the Revolution pump generated the highest hemolysis.展开更多
基金supported by the National Natural Science Foundation of China(61271315)the State Scholarship Fund of China
文摘Image matching based on scale invariant feature transform（SIFT） is one of the most popular image matching algorithms, which exhibits high robustness and accuracy. Grayscale images rather than color images are generally used to get SIFT descriptors in order to reduce the complexity. The regions which have a similar grayscale level but different hues tend to produce wrong matching results in this case. Therefore, the loss of color information may result in decreasing of matching ratio. An image matching algorithm based on SIFT is proposed, which adds a color offset and an exposure offset when converting color images to grayscale images in order to enhance the matching ratio. Experimental results show that the proposed algorithm can effectively differentiate the regions with different colors but the similar grayscale level, and increase the matching ratio of image matching based on SIFT. Furthermore, it does not introduce much complexity than the traditional SIFT.
基金The author(s)disclosed receipt of the following financial support for the research,authorship,and/or publication of this article:This work was funded by National Institutes of Health(Grant Numbers:R01HL118372,R01HL124170,R01HL131750,and R01HL141817)This publication was made possible by the University of Maryland Baltimore Institute for Clinical and Translational Research(ICTR)which is funded in part by Grant Number TL1 TR003100 from the National Center for Advancing Translational Sciences(NCATS)a component of the National Institutes of Health(NIH),and NIH Roadmap for Medical Research.Its contents are solely the responsibility of the authors and do not necessarily represent the official view of the University of Maryland Baltimore ICTR,NCATS or NIH.
文摘Centrifugal blood pumps have become popular for adult extracorporeal membrane oxygenation(ECMO)due to their superior blood handling and reduced thrombosis risk featured by their secondary flow paths that avoid stagnant areas.However,the high rotational speed within a centrifugal blood pump can introduce high shear stress,causing a significant shear-induced hemolysis rate.The Revolution pump,the Rotaflow pump,and the CentriMag pump are three of the leading centrifugal blood pumps on the market.Although many experimental and computational studies have focused on evaluating the hydraulic and hemolytic performances of the Rotaflow and CentriMag pumps,there are few on the Revolution pump.Furthermore,a thorough direct comparison of these three pumps'flow characteristics and hemolysis is not available.In this study,we conducted a computational and experimental analysis to compare the hemolytic performances of the Revolution,Rotaflow,and CentriMag pumps operating under a clinically relevant condition,i.e.,the blood flow rate of 5 L/min and pump pressure head of 350 mmHg,for adult ECMO support.In silico simulations were used to characterize the shear stress distributions and predict the hemolysis index,while in vitro blood loop studies experimentally determined hemolysis performance.Comparative simulation results and experimental data demonstrated that the CentriMag pump caused the lowest hemolysis while the Revolution pump generated the highest hemolysis.
