Modelling Soft Tissue Deformation Based On Kriging

As a kind of biopsy which can effectively reduce the pain of patients,percutaneous puncture has been used in the pre-detection of various diseases.In order to improve the accuracy of percutaneous puncture,it is necessary to establish a fast and accurate soft tissue model.Because of the complex mechanical properties of soft tissue,the traditional modeling method is not suitable for soft tissue modeling,while the Kriging model can fit the nonlinear function by semi-variance function.In this paper,the principle of Kriging model is deduced in detail,and the concepts of spatio-temporal Kriging model and spatio-temporal semi-variance function are put forward on the basis of ordinary Kriging.Through data analysis and change,cross-validation function types,ArcGIS software modeling and other steps to calculate the spatial semi-variance function and time semi-variance function,and replace it into the spatio-temporal semi-variance function to establish a soft tissue model based on spatio-temporal Kriging.The deformation prediction ability and corresponding error of the model are analyzed.An independent puncture experiment was designed to verify the practicability and accuracy of the soft tissue model.B ultrasonic probe was used to observe and record the changes of soft tissue during the puncture process,and the collected images were processed through multiple image processing steps to get the final puncture results and displacement data.Finally,the predicted value of kriging soft tissue model is compared with the experimental data to verify the accuracy of the model.In this paper,based on the ordinary Kriging model,it is extended to the spatio-temporal Kriging model,and its soft tissue deformation model based on Kriging is established,and the accuracy is verified by independent experiments.This paper lays an important foundation for the automation of percutaneous puncture and is of great significance.