scholarly journals Dynamic Path Planning for Bevel-Tip Flexible Needle Insertion into Soft Tissue Based on a Real-Time Finite Element Model

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Murong Li ◽  
Dedong Gao ◽  
Yong Lei ◽  
Tian Xu
Keyword(s):  
Finite Element ◽  
Soft Tissue ◽  
Path Planning ◽  
Finite Element Model ◽  
Real Time ◽  
Ccd Camera ◽  
Element Model ◽  
Online Planning ◽  
Dynamic Path Planning ◽  
Dynamic Path

This paper presents a novel dynamic path planning methodology for needle steering into the soft tissue. A real-time finite element model is used to simulate the procedure of a flexible needle into the homogeneous soft tissue, which provides the dynamic deformation information for the path planning. The relationship between needle base and tip is formulated as the transformations of homogeneous matrix with quasi-static assumptions. Based on the reachability of the flexible needle, the real-time motions of obstacles and target are considered through the dynamic needle-tissue interactions. A testbed including a XY linear stage, one rotator, and a CCD camera is constructed, and the experiments are designed to validate the proposed method. The 23G PTC needle was inserted into the PVA phantom with markers, and the CCD camera was utilized to record the needle trajectories and motions of target and obstacles. The targeting errors between the experimental and planned paths are less than 1.20 mm, and the distance from the obstacle to needle is not smaller than 1.16 mm. The results demonstrate that the proposed algorithm is effective for online planning the paths in the needle-tissue interactive environment.

scholarly journals Biaxial estimation of biomechanical constitutive parameters of passive porcine sclera soft tissue

2021 ◽  
Author(s):  
Zwelihle Ndlovu ◽  
Dawood Desai ◽  
Thanyani Pandelani ◽  
Harry Ngwangwa ◽  
Fulufhelo Nemavhola
Keyword(s):  
Finite Element ◽  
Soft Tissue ◽  
Finite Element Model ◽  
Test Data ◽  
Element Model ◽  
Finite Element Models ◽  
Anisotropic Model ◽  
Material Models ◽  
Material Parameters ◽  
Constitutive Parameters

This study assesses the modelling capabilities of four constitutive hyperplastic material models to fit the experimental data of the porcine sclera soft tissue. It further estimates the material parameters and discusses their applicability to a finite element model by examining the statistical dispersion measured through the standard deviation. Fifteen sclera tissues were harvested from porcine’ slaughtered at an abattoir and were subjected to equi-biaxial testing. The results show that all the four material models yielded very good correlations at correlations above 96 %. The polynomial (anisotropic) model gave the best correlation of 98 %. However, the estimated material parameters varied widely from one test to another such that there would be needed to normalise the test data to avoid long optimisation processes after applying the average material parameters to finite element models. However, for application of the estimated material parameters to finite element models, there would be needed to consider normalising the test data to reduce the search region for the optimisation algorithms. Although the polynomial (anisotropic) model yielded the best correlation, it was found that the Choi-Vito had the least variation in the estimated material parameters thereby making it an easier option for application of its material parameters to a finite element model and also requiring minimum effort in the optimisation procedure. For the porcine sclera tissue, it was found that the anisotropy more influenced by the fiber-related properties than the background material matrix related properties.

scholarly journals A Vision-Based Approach for Estimating Contact Forces: Applications to Robot-Assisted Surgery

2005 ◽  
Vol 2 (1) ◽  
pp. 53-60 ◽  
Author(s):  
C. W. Kennedy ◽  
J. P. Desai
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Real Time ◽  
Force Feedback ◽  
Element Model ◽  
Robot Arm ◽  
Robot Assisted ◽  
Interaction Forces ◽  
Fem Model ◽  
Nodal Displacements

The primary goal of this paper is to provide force feedback to the user using vision-based techniques. The approach presented in this paper can be used to provide force feedback to the surgeon for robot-assisted procedures. As proof of concept, we have developed a linear elastic finite element model (FEM) of a rubber membrane whereby the nodal displacements of the membrane points are measured using vision. These nodal displacements are the input into our finite element model. In the first experiment, we track the deformation of the membrane in real-time through stereovision and compare it with the actual deformation computed through forward kinematics of the robot arm. On the basis of accurate deformation estimation through vision, we test the physical model of a membrane developed through finite element techniques. The FEM model accurately reflects the interaction forces on the user console when the interaction forces of the robot arm with the membrane are compared with those experienced by the surgeon on the console through the force feedback device. In the second experiment, the PHANToM haptic interface device is used to control the Mitsubishi PA-10 robot arm and interact with the membrane in real-time. Image data obtained through vision of the deformation of the membrane is used as the displacement input for the FEM model to compute the local interaction forces which are then displayed on the user console for providing force feedback and hence closing the loop.

scholarly journals New Algorithm for Autonomous Dynamic Path Planning in Real-Time Intelligent Robot Car

2017 ◽  
Vol 14 (11) ◽  
pp. 5499-5507
Author(s):  
Aqeel A. Mohammed ◽  
Ishak Aris ◽  
Mohd Khair Hassan ◽  
Noor Ain Kamsani
Keyword(s):  
Path Planning ◽  
Real Time ◽  
Intelligent Robot ◽  
Dynamic Path Planning ◽  
Dynamic Path

Methods for Reducing a Thermal Finite Element Model Including the Advection Network Contribution

2006 ◽  
Author(s):  
Daniele Botto ◽  
Stefano Zucca ◽  
Muzio M. Gola
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Real Time ◽  
Residual Life ◽  
Mathematical Formulation ◽  
Time Integration ◽  
Element Model ◽  
Computational Time ◽  
Fatigue Damage Accumulation ◽  
Secondary Air

The life monitoring concept needs on-line calculation to evaluate stresses and temperatures on aircraft engine components, in order to asses fatigue damage accumulation and residual life. Due to the amount of computational time required it is not possible for a full finite element model to operate in real time using the on-board CPU. Stresses and temperatures are then evaluated by using simplified algorithms. In the present work Guyan reduction and component mode synthesis have been applied to a thermal finite element model, including the cooling stream flow — the so called advection network — in order to reduce the size of the solving equation system. The appropriate mathematical formulation for the advection network reduction has been developed. Two reduction methods have been performed, discussed and subsequently applied to a thermal finite element model of a real low pressure turbine disk. The reduced system includes both the disk and the correlated fluid network model, simulating turbine secondary air system. The finite element model is axi-symmetric, with constant convective coefficients. Results of time integration for the reduced and the complete models have been compared. Results show that the proposed techniques gives models with a reduced number of degrees of freedom and at the same time good accuracy in temperature calculation. The reduced models are then suitable for real time computation.

Non-Invasive Test of Soft Tissue for Tissue Reaction in Needle Biopsy

2011 ◽  
Vol 66-68 ◽  
pp. 983-988
Author(s):  
M. Liu ◽  
Q.H. Zhang ◽  
L.Y. Gao ◽  
Xue Mei Qin
Keyword(s):  
Finite Element ◽  
Soft Tissue ◽  
Finite Element Model ◽  
Needle Biopsy ◽  
Element Model ◽  
Tissue Reaction ◽  
Medical Procedure ◽  
Non Invasive ◽  
Invasive Test ◽  
Force Time

Needle biopsy is a widely used medical procedure in which a tissue sample is cut and removed by needle for examination to identify and diagnose cancer and other diseases. Predictions of soft tissue deformation and reaction caused by needle insertion are important for the accuracy of this procedure. In this paper, in order to aquire the properties of soft tissue, indentation experiments of porcine livers are performed as non-invasive test to measure the force response depending on time in various indentation depth and indentation velocities conditions. A nonlinear least square method on Matlab have been created to fit the indentation results. According to the experimental and fitting indentation force-time curves, the coefficients of Neo-Hookean model and Kelvin model which are selected to develop the nonlinear model of porcine liver are acquired . Finally, a finite element model of liver based on experimental data is finally developed and succeeds in simulating the stress relaxation character and force-time curve. This finite element model and methodology can be used to investigate soft tissue reaction in needle biopsy.

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