基于时空Kriging的软组织模型

Modelling soft tissue based on spatial-temporal Kriging

为了缓解现有软组织模型实时性与精确性之间的矛盾,提出了一种以Kriging算法为基础的新型软组织模型。阐述了Kriging算法的基本原理与模型关键环节(变异函数的作用与结构),使用B超探头采集实验过程中的超声图像,经过Matlab处理之后获得原始位移数据,将这些数据代入纯空间和纯时间的变异函数模型,并在此基础上建立积和式时空变异模型,最终得到时空Kriging软组织模型。结果表明:时空变异模型的平均误差为0.5 mm。时空Kriging模型与纯空间普通Kriging模型效果进行比对,误差降低了20%,时空Kriging模型与另一组实验数据进行比较,平均偏差为0.2 mm。该模型的实时性与精确性均较好,完全可以满足手术需要。

In order to alleviate the contradiction between the real-time and precision of the existing soft tissue model,a new soft tissue model based on the Kriging algorithm is proposed.The basic principle of Kriging algorithm and the function as well as the structure of the semi variance function that is the key link of the model are described.Using the B-superprobe to capture the original images during the experiment,the original displacement data is obtained after Matlab processing.The data is substituted into the pure space and pure time variogram models to build the product sum and spatial temporal variation model such that the soft tissue model of space time Kriging is obtained at the end.The results show that the average error of the space time variation model is 0.5 mm.Moreover,compared with the ordinary Kriging interpolation effect in pure space,the error is reduced by 20%,compared with the another set of ecperimental data,the average deviation of spatialtemporal model is 0.2 mm.The results suggest that the real time and accuracy of the spatialtemporal model are good,which can fully meet the needs of surgery.