Open Science Article Submitted: May 20, 2008https://doi.org/10.54294/de1qkd

Integration of Geometrical Boundary Conditions on Soft Tissue Characterization under large deformation

Ahn, Bummo^1*

,Kim, Jung

1.Korea Advanced Institute of Science and Technology (KAIST)

Abstract

Soft tissue characterization with finite element (FE) modeling is important to develop a realistic model for medical simulation, since it is possible to display complex tool-tissue interactions during medical interventions. However, it is difficult to integrate large deformation and geometrical boundary conditions to the FE computations. In this paper, the force responses and surface deformation fields of the tissues against the indentation were measured by a force transducer and three-dimensional optical system. Large indentation experiments on porcine liver were performed to estimate the radius of influence from the indented point up to 8 mm indentation and to measure the force response for 7mm indentation. The radius of influence region was plotted against various indentation depths and indenter shapes, and it could be used to determine the model size for the characterization. The tissue behavior of large deformation considering influence of the boundary conditions was characterized with FE modeling via hyperelastic and linear viscoelastic model.

Keywords

Soft tissue characterization

Inverse FE parameter optimization algorithm

Indentation experiment

Finite element method

Surface deformation

Source Code and Data

No source code files available for this publication.

Reviews

Tonmoy Dutta roy

Monday 7 July 2008

Paper authors and title:

Integration of Geometrical Boundary Conditions on Soft Tissue Characterization under large deformation Bummo Ahn and Jung Kim

Please, rank the following on the scale from 1 (worst) to 5 (best)

Originality 2

Methodological originality 2

Biologic originality 2

Completeness of discussion 3

Appropriate references 2

Organisation 3

Clarity 3

Is the technical treatment plausible and free from technical errors? Yes

Have you checked the equations NA

Are you aware of prior publication or presentation of this work No

Is the paper too long No

Recommendation:

(A) Accept

(B) Accept subject to minor revisions

(D) Reject

Reject

Should this paper be presented as poster or as podium presentation (this recommendation does not reflect upon the relative quality of the paper)?

Comments to the manuscript:

Though the paper tries to investigate a relevant clinical procedure (needle insertion/surgical simulation), the authors fail to differentiate their work from those of Dr Salcudean’s group (Dr DiMaio) at UBC, Canada and Dr Adam Wittek’s team (UWA, Perth). The authors claim in their paper that no other published work exists on needle insertion/surgical simulation, which takes into account finite deformation and non-linear constitutive law. I would strongly urge the authors to follow the work of Dr Adam Wittek at UWA (Wittek, A., Dutta-Roy, T., Taylor, Z., Horton, A., Washio, T., Chinzei, K. and Miller, K., Subject Specific Non-Linear Biomechanical Model of Needle Insertion into Brain, Computer Methods in Biomechanics and Biomedical Engineering, 2008, 11 (2), 135-146; Wittek A., Dutta-Roy T., Miller K., Biomechanics of Needle Insertion into Brain Using Non Linear Biomechanical Model, Proceedings of the 7^th International Symposium on Computer Methods in Biomechanics and Biomedical Engineering, 22^nd – 25^th March 2006, Antibes, Cote D’ Azur, France, pp. 870-875 and Dutta-Roy, T., Wittek A., Taylor, Z., Chinzei, K., Washio T., Miller, K., Towards Realistic Surgical Simulation: Biomechanics of Needle Insertion into Brain, Proceedings of the 16^th CISM-IFToMM Symposium on Robot Design, Dynamics and Control, RoManSy 2006 Symposium, Warsaw University of Technology, Warsaw, Poland, 22^nd -25^th March 2006, pp. 297-304 etc). The authors would find that Dr Wittek and his team in their papers argue precisely for a fully non linear model (finite deformations, non-linear constitutive law and non-linear boundary conditions) to completely understand the mechanics of needle insertion/surgical simulation.

The current approach taken by the authors in the paper slightly varies from the work done by Dr DiMaio (Simon P. DiMaio, S. E. Salcudean: Needle Insertion Modelling and Simulation. ICRA 2002: 2098-2105 etc). It uses the same methodology proposed by Dr DiMaio for measuring the deformation field using digital CCD cameras, though, the authors use it on porcine liver.

Also, the reviewer has difficulties to understand why the authors use an inverse FE parameter optimization methodology to characterise the porcine liver properties when the same could be done using the techniques described by Prof Miller (ISML, UWA, Perth, Australia) (Miller K. (2005) “Method of testing soft biological tissues in compression” J. Biomechanics. Vol. 38, Issue 1, 153-158 etc.). The method proposed by Prof Miller is simpler and easier to co-relate to the physical world as it directly deals with mechanical testing of the tissue. Also, in Table 2, the reviewer fails to understand why the same porcine liver would have different viscoelastic and hyperelastic parameters for different indenter shapes. Are two different porcine livers used for each kind of indenter shapes?

On the reasons given above, the reviewer feels that the paper does not introduce any new material for discussions in the workshop and hence would argue against accepting the paper.