Mathematical model describing the processes of mechanical stress development in response to strain of heterogeneous muscle fiber is created. The numerical algorithm to calculate viscoelastic properties of muscle fiber...Mathematical model describing the processes of mechanical stress development in response to strain of heterogeneous muscle fiber is created. The numerical algorithm to calculate viscoelastic properties of muscle fiber of arbitrary length is developed. In numerical experiments by the model it is shown that the local heterogeneity of geometrical and mechanical parameters of structural units of the model significantly influences in resulting mechanical response of whole fiber. Also it is established the close connection between parameters of mechanical and geometrical heterogeneity compensating each other. It is supposed that the mechanism may modulate the myocardial remodeling under changing load.展开更多
核磁共振弥散张量成像（Diffusion Tensor Magnetic Resonance Imaging,DT-MRI）是近年来提出的一项新的医学影像技术。通过利用核磁共振技术测量细胞内多个方向上水分子弥散运动的特征,可以全面充分研究活体组织微细结构。基于犬心室的...核磁共振弥散张量成像（Diffusion Tensor Magnetic Resonance Imaging,DT-MRI）是近年来提出的一项新的医学影像技术。通过利用核磁共振技术测量细胞内多个方向上水分子弥散运动的特征,可以全面充分研究活体组织微细结构。基于犬心室的DT-MRI数据集开展了三维心肌纤维结构的可视化方法及其可视化系统设计与实现的研究。首先利用阈值滤波、中值滤波和邻域平均法对原始DT-MRI数据进行去噪预处理,然后利用体绘制技术、图元显示法和纤维跟踪法对犬心室的DT-MRI数据进行可视化。最后对基于DT-MRI数据的心肌纤维可视化应用进行了详细的需求分析和系统设计,基于VTK（Visualization Toolkit）实现一个DT-MRI数据的心肌纤维可视化和分析系统。实验结果表明该系统具有良好的交互性,为研究心脏结构提供了一个有力可视化工具。展开更多
文摘Mathematical model describing the processes of mechanical stress development in response to strain of heterogeneous muscle fiber is created. The numerical algorithm to calculate viscoelastic properties of muscle fiber of arbitrary length is developed. In numerical experiments by the model it is shown that the local heterogeneity of geometrical and mechanical parameters of structural units of the model significantly influences in resulting mechanical response of whole fiber. Also it is established the close connection between parameters of mechanical and geometrical heterogeneity compensating each other. It is supposed that the mechanism may modulate the myocardial remodeling under changing load.
