针对在初始先验信息缺失时磁性目标滤波跟踪方法发散问题进行研究,本文提出了一种多初值模型的解决框架,并以平方根形式的中心差分卡尔曼滤波器(Square-Root Central Difference Kalman Filter,SRCDKF)为例,结合多初值模型得到了SRCDKF...针对在初始先验信息缺失时磁性目标滤波跟踪方法发散问题进行研究,本文提出了一种多初值模型的解决框架,并以平方根形式的中心差分卡尔曼滤波器(Square-Root Central Difference Kalman Filter,SRCDKF)为例,结合多初值模型得到了SRCDKF自适应磁性目标跟踪算法.文章首先根据远距离磁偶极子的磁场等效性,建立了多初值滤波跟踪模型,然后基于最大似然选择理论推导了如何从多模型中选择最佳结果,即多初值模型的选择方法,最后以SRCDKF滤波器为滤波单元,得到了基于SRCDKF的自适应磁性目标跟踪算法.经过仿真试验表明:(1)多初值模型建立和选择方法的有效性;(2)基于SRCDKF的自适应磁性目标跟踪算法,在初始位置信息缺失的情况下,能够有效完成对磁性目标的跟踪;(3)以不同滤波器为滤波单元的自适应跟踪算法跟踪试验结果表明,多初值模型的解决框架可解决初值先验未知下的跟踪问题.展开更多
Recently,transplantation of allogeneic and autologous cells has been used for regenerative medicine.A critical issue is monitoring migration and homing of transplanted cells,as well as engraftment efficiency and funct...Recently,transplantation of allogeneic and autologous cells has been used for regenerative medicine.A critical issue is monitoring migration and homing of transplanted cells,as well as engraftment efficiency and functional capability in vivo.Monitoring of superparamagnetic iron oxide(SPIO) particles by magnetic resonance imaging(MRI) has been used in animal models and clinical settings to track labeled cells.A major limitation of MRI is that the signals do not show biological characteristics of transplanted cells in vivo.Bone marrow mesenchymal stem cells(MSCs) have been extensively investigated for their various therapeutic properties,and exhibit the potential to differentiate into cells of diverse lineages.In this study,cynomolgus monkey MSCs(cMSCs) were labeled with Molday ION Rhodamine-BTM(MIRB),a new SPIO agent,to investigate and characterize the biophysical and MRI properties of labeled cMSCs in vitro and in vivo.The results indicate that MIRB is biocompatible and useful for cMSCs labeling and cell tracking by multimodality imaging.Our method is helpful for detection of transplanted stem cells in vivo,which is required for understanding mechanisms of cell therapy.展开更多
文摘针对在初始先验信息缺失时磁性目标滤波跟踪方法发散问题进行研究,本文提出了一种多初值模型的解决框架,并以平方根形式的中心差分卡尔曼滤波器(Square-Root Central Difference Kalman Filter,SRCDKF)为例,结合多初值模型得到了SRCDKF自适应磁性目标跟踪算法.文章首先根据远距离磁偶极子的磁场等效性,建立了多初值滤波跟踪模型,然后基于最大似然选择理论推导了如何从多模型中选择最佳结果,即多初值模型的选择方法,最后以SRCDKF滤波器为滤波单元,得到了基于SRCDKF的自适应磁性目标跟踪算法.经过仿真试验表明:(1)多初值模型建立和选择方法的有效性;(2)基于SRCDKF的自适应磁性目标跟踪算法,在初始位置信息缺失的情况下,能够有效完成对磁性目标的跟踪;(3)以不同滤波器为滤波单元的自适应跟踪算法跟踪试验结果表明,多初值模型的解决框架可解决初值先验未知下的跟踪问题.
基金supported by the National Basic Research Program of China (Grant No. 2007CB947704)Research Assistance Fund of Anhui Medical University (Grant No. XJ201008)
文摘Recently,transplantation of allogeneic and autologous cells has been used for regenerative medicine.A critical issue is monitoring migration and homing of transplanted cells,as well as engraftment efficiency and functional capability in vivo.Monitoring of superparamagnetic iron oxide(SPIO) particles by magnetic resonance imaging(MRI) has been used in animal models and clinical settings to track labeled cells.A major limitation of MRI is that the signals do not show biological characteristics of transplanted cells in vivo.Bone marrow mesenchymal stem cells(MSCs) have been extensively investigated for their various therapeutic properties,and exhibit the potential to differentiate into cells of diverse lineages.In this study,cynomolgus monkey MSCs(cMSCs) were labeled with Molday ION Rhodamine-BTM(MIRB),a new SPIO agent,to investigate and characterize the biophysical and MRI properties of labeled cMSCs in vitro and in vivo.The results indicate that MIRB is biocompatible and useful for cMSCs labeling and cell tracking by multimodality imaging.Our method is helpful for detection of transplanted stem cells in vivo,which is required for understanding mechanisms of cell therapy.
