A novel laparoscopic grasper with two parallel jaws capable of extracting the mechanical behaviour of soft tissues

2017 ◽  
Vol 41 (5) ◽  
pp. 339-345 ◽  
Author(s):  
Dariush Nazarynasab ◽  
Farzam Farahmand ◽  
Alireza Mirbagheri ◽  
Elnaz Afshari
Keyword(s):  
Mechanical Behaviour ◽  
Soft Tissues ◽  
Laparoscopic Grasper

scholarly journals Constitutive modelling of arteries

2010 ◽  
Vol 466 (2118) ◽  
pp. 1551-1597 ◽  
Author(s):  
Gerhard A. Holzapfel ◽  
Ray W. Ogden
Keyword(s):  
Mechanical Behaviour ◽  
Soft Tissues ◽  
Elastic Strain Energy ◽  
Cylindrical Tube ◽  
Strain Energy Function ◽  
Biological Tissues ◽  
Constitutive Modelling ◽  
Highly Nonlinear ◽  
Wide Range ◽  
Modelling Effort

This review article is concerned with the mathematical modelling of the mechanical properties of the soft biological tissues that constitute the walls of arteries. Many important aspects of the mechanical behaviour of arterial tissue can be treated on the basis of elasticity theory, and the focus of the article is therefore on the constitutive modelling of the anisotropic and highly nonlinear elastic properties of the artery wall. The discussion focuses primarily on developments over the last decade based on the theory of deformation invariants, in particular invariants that in part capture structural aspects of the tissue, specifically the orientation of collagen fibres, the dispersion in the orientation, and the associated anisotropy of the material properties. The main features of the relevant theory are summarized briefly and particular forms of the elastic strain-energy function are discussed and then applied to an artery considered as a thick-walled circular cylindrical tube in order to illustrate its extension–inflation behaviour. The wide range of applications of the constitutive modelling framework to artery walls in both health and disease and to the other fibrous soft tissues is discussed in detail. Since the main modelling effort in the literature has been on the passive response of arteries, this is also the concern of the major part of this article. A section is nevertheless devoted to reviewing the limited literature within the continuum mechanics framework on the active response of artery walls, i.e. the mechanical behaviour associated with the activation of smooth muscle, a very important but also very challenging topic that requires substantial further development. A final section provides a brief summary of the current state of arterial wall mechanical modelling and points to key areas that need further modelling effort in order to improve understanding of the biomechanics and mechanobiology of arteries and other soft tissues, from the molecular, to the cellular, tissue and organ levels.

scholarly journals Multi-scale modelling of rubber-like materials and soft tissues: an appraisal

2016 ◽  
Vol 472 (2187) ◽  
pp. 20160060 ◽  
Author(s):  
G. Puglisi ◽  
G. Saccomandi
Keyword(s):  
Mathematical Models ◽  
Phenomenological Models ◽  
Mechanical Behaviour ◽  
Soft Tissues ◽  
Mechanical Response ◽  
Multi Scale ◽  
Bioinspired Materials ◽  
Macroscopic Properties ◽  
Network Scale ◽  
Scale Modelling

We survey, in a partial way, multi-scale approaches for the modelling of rubber-like and soft tissues and compare them with classical macroscopic phenomenological models. Our aim is to show how it is possible to obtain practical mathematical models for the mechanical behaviour of these materials incorporating mesoscopic (network scale) information. Multi-scale approaches are crucial for the theoretical comprehension and prediction of the complex mechanical response of these materials. Moreover, such models are fundamental in the perspective of the design, through manipulation at the micro- and nano-scales, of new polymeric and bioinspired materials with exceptional macroscopic properties.

Isotropic incompressible hyperelastic models for modelling the mechanical behaviour of biological tissues: a review

2015 ◽  
Vol 60 (6) ◽  
Author(s):  
Cora Wex ◽  
Susann Arndt ◽  
Anke Stoll ◽  
Christiane Bruns ◽  
Yuliya Kupriyanova
Keyword(s):  
Mechanical Behaviour ◽  
Strain Energy ◽  
Soft Tissues ◽  
Strain Energy Function ◽  
Biological Tissues ◽  
Tissue Response ◽  
Large Strains ◽  
Energy Functions ◽  
Strain Energy Functions ◽  
Hyperelastic Models

AbstractModelling the mechanical behaviour of biological tissues is of vital importance for clinical applications. It is necessary for surgery simulation, tissue engineering, finite element modelling of soft tissues, etc. The theory of linear elasticity is frequently used to characterise biological tissues; however, the theory of nonlinear elasticity using hyperelastic models, describes accurately the nonlinear tissue response under large strains. The aim of this study is to provide a review of constitutive equations based on the continuum mechanics approach for modelling the rate-independent mechanical behaviour of homogeneous, isotropic and incompressible biological materials. The hyperelastic approach postulates an existence of the strain energy function – a scalar function per unit reference volume, which relates the displacement of the tissue to their corresponding stress values. The most popular form of the strain energy functions as Neo-Hookean, Mooney-Rivlin, Ogden, Yeoh, Fung-Demiray, Veronda-Westmann, Arruda-Boyce, Gent and their modifications are described and discussed considering their ability to analytically characterise the mechanical behaviour of biological tissues. The review provides a complete and detailed analysis of the strain energy functions used for modelling the rate-independent mechanical behaviour of soft biological tissues such as liver, kidney, spleen, brain, breast, etc.

scholarly journals Modelling indentation of human lower-limb soft tissue: simulation parameters and their effects

2020 ◽  
Author(s):  
Theodoros Marinopoulos ◽  
Lorenzo Zani ◽  
Simin Li ◽  
Vadim V. Silberschmidt
Keyword(s):  
Finite Element ◽  
Mechanical Behaviour ◽  
Lower Limb ◽  
Soft Tissues ◽  
High Sensitivity ◽  
Biological Tissues ◽  
Finite Element Models ◽  
Mechanical Responses ◽  
Reaction Forces ◽  
Human Participants

Abstract Modern developments of biomedical applications demand a better understanding of mechanical behaviour of soft biological tissues. As human soft tissues demonstrate a significant structural and functional diversity, characterisation of their mechanical behaviour still remains a challenge. Limitations related with implementation of mechanical experiments on human participants lead to a use of finite-element models for analysis of mechanical responses of soft tissues to different loads. This study focuses on parameters of numerical simulation considered for modelling of indentation of a human lower limb. Assessment of the effect of boundary conditions on the model size shows that at a ratio of its length to the tissue’s thickness of 1.7 for the 3D model this effect vanishes. The numerical results obtained with models employing various sets of mechanical parameters of the first-order Ogden scheme were compared with original experimental data. Furthermore, high sensitivity of the resulting reaction forces to the indenting direction is demonstrated for cases of both linear and angular misalignments of the indenter. Finally, the effect of changes in material parameters and their domain on their contribution to the reaction forces is discussed with the aim to improve our understanding of mechanical behaviour of soft tissues based on numerical methods. The undertaken research with its results on minimal requirements for finite-element models of indentation of soft tissues can support inverse analysis of their mechanical properties and underpin orthopaedic and medical procedures.

Customizable Soft Pneumatic Chamber–Gripper Devices for Delicate Surgical Manipulation

2014 ◽  
Vol 8 (4) ◽  
Author(s):  
Jin-Huat Low ◽  
Ignacio Delgado-Martinez ◽  
Chen-Hua Yeow
Keyword(s):  
Soft Lithography ◽  
Soft Tissues ◽  
High Stress ◽  
Compressive Force ◽  
Outer Wall ◽  
Tissue Manipulation ◽  
Laparoscopic Grasper ◽  
Pneumatic Chamber ◽  
Tissue Trauma ◽  
Surgical Manipulation

Traditional hard tissue grippers are limited in handling delicate soft tissues during surgery, particularly due to the high stress points that are generated on the soft tissue during gripping. In this study, customizable soft pneumatic chamber–gripper devices were designed to provide compliant gripping, so as to replace conventional tissue grippers such as the laparoscopic grasper or forceps in delicate tissue manipulation. The soft chamber–gripper device involves very simple design and control to generate actuation. It is fabricated from an elastomeric material using a modified soft lithography technique. The device consists of a gripper component that can be made up of one or more gripper arms with a pneumatic channel in each arm, and a chamber filled with air. The pneumatic channels are positioned close to the outer wall of the gripper arms and are connected to the chamber. Upon compression of the chamber, the pneumatic channels will inflate towards the outer walls, which thus bends the gripper arms and results in a closed gripping posture. This soft chamber–gripper device can be used to pick up objects of size up to 2 mm with a compressive force that is more than three times smaller than the grip force generated by traditional forceps. This will be useful in preventing tissue trauma during surgical manipulation, especially in nerve anastomosis.

Rapid Critical Point Drying of Tissues in a Parr Bomb

1972 ◽  
Vol 30 ◽  
pp. 400-401
Author(s):  
C.A. Baechler ◽  
W. C. Pitchford ◽  
J. M. Riddle ◽  
C.B. Boyd ◽  
H. Kanagawa ◽  
...  
Keyword(s):  
Critical Point ◽  
Critical Pressure ◽  
Soft Tissues ◽  
Biological Tissues ◽  
Critical Temperatures ◽  
Air Drying ◽  
The Past ◽  
Critical Point Drying ◽  
Great Stress ◽  
Infiltration Techniques

Preservation of the topographic ultrastructure of soft biological tissues for examination by scanning electron microscopy has been accomplished in the past by using lengthy epoxy infiltration techniques, or dehydration in ethanol or acetone followed by air drying. Since the former technique requires several days of preparation and the latter technique subjects the tissues to great stress during the phase change encountered during air-drying, an alternate rapid, economical, and reliable method of surface structure preservation was developed. Turnbill and Philpott had used a fluorocarbon for the critical point drying of soft tissues and indicated the advantages of working with fluids having both moderately low critical pressures as well as low critical temperatures. Freon-116 (duPont) which has a critical temperature of 19. 7 C and a critical pressure of 432 psi was used in this study.

SEM analysis of fish scale cross sections: A technique study

1992 ◽  
Vol 50 (1) ◽  
pp. 744-745
Author(s):  
M.E. Lee ◽  
A. Moller ◽  
P.S.O. Fouche ◽  
I.G Gaigher
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Cross Sections ◽  
Soft Tissues ◽  
Close Association ◽  
Sem Analysis ◽  
Fish Scale ◽  
Fish Scales ◽  
Micro Structures ◽  
Scanning Electron

Scanning electron microscopy of fish scales has facilitated the application of micro-structures to systematics. Electron microscopy studies have added more information on the structure of the scale and the associated cells, many problems still remain unsolved, because of our incomplete knowledge of the process of calcification. One of the main purposes of these studies has been to study the histology, histochemistry, and ultrastructure of both calcified and decalcified scales, and associated cells, and to obtain more information on the mechanism of calcification in the scales. The study of a calcified scale with the electron microscope is complicated by the difficulty in sectioning this material because of the close association of very hard tissue with very soft tissues. Sections often shatter and blemishes are difficult to avoid. Therefore the aim of this study is firstly to develop techniques for the preparation of cross sections of fish scales for scanning electron microscopy and secondly the application of these techniques for the determination of the structures and calcification of fish scales.

Sign in / Sign up

Export Citation Format

Share Document