Real-Time FEM of Soft Tissues for Virtual Surgery

2009 ◽  
Author(s):  
Christian Willberg ◽  
Harald Berger ◽  
Ulrich Gabbert
Keyword(s):  
Real Time ◽  
Soft Tissues ◽  
Force Feedback ◽  
Surgical Instruments ◽  
Virtual Surgery ◽  
Continuous Training ◽  
Endoscopic Techniques ◽  
Organ Models ◽  
Small Perforation ◽  
High Level

Endoscopic techniques require small perforation holes only as entries for optical and surgical instruments; such enabling the treatment of injuries with a minimized damage of the surrounding health tissue. But the surgeon has to operate in a 3D domain by looking at a distorted 2D image at the screen. It is well known, that a good surgeon needs a continuous training to perform such operations reliable in a top quality. To overcome the high costs and tight ethical restrictions of animal based education and training has result in an increasing development and application of virtual surgery simulators [1]. One of the main issues of surgery simulators is to ensure simultaneously the real time performance of the device, the high-level image representation and an acceptable force-feedback behavior. The basics of such simulators are mathematical models of the involved soft tissues, which have to perform in a realistic physical manner, with dynamic nonlinear large deformations, including the interaction of the different constituents (instrument/organ, organ/organ, organ by itself, cutting, bleeding etc). In the paper the focus is on realistic organ models and the realization of a fast contact search and reaction algorithm.

scholarly journals A Systematic Review of Real-Time Medical Simulations with Soft-Tissue Deformation: Computational Approaches, Interaction Devices, System Architectures, and Clinical Validations

2020 ◽  
Vol 2020 ◽  
pp. 1-30 ◽  
Author(s):  
Tan-Nhu Nguyen ◽  
Marie-Christine Ho Ba Tho ◽  
Tien-Tuan Dao
Keyword(s):  
Systematic Review ◽  
Soft Tissue ◽  
Real Time ◽  
Review Process ◽  
Soft Tissues ◽  
Force Feedback ◽  
Surgical Instruments ◽  
Assessment Procedure ◽  
System Architectures ◽  
Computational Approaches

Simulating deformations of soft tissues is a complex engineering task, and it is even more difficult when facing the constraint between computation speed and system accuracy. However, literature lacks of a holistic review of all necessary aspects (computational approaches, interaction devices, system architectures, and clinical validations) for developing an effective system of soft-tissue simulations. This paper summarizes and analyses recent achievements of resolving these issues to estimate general trends and weakness for future developments. A systematic review process was conducted using the PRISMA protocol with three reliable scientific search engines (ScienceDirect, PubMed, and IEEE). Fifty-five relevant papers were finally selected and included into the review process, and a quality assessment procedure was also performed on them. The computational approaches were categorized into mesh, meshfree, and hybrid approaches. The interaction devices concerned about combination between virtual surgical instruments and force-feedback devices, 3D scanners, biomechanical sensors, human interface devices, 3D viewers, and 2D/3D optical cameras. System architectures were analysed based on the concepts of system execution schemes and system frameworks. In particular, system execution schemes included distribution-based, multithread-based, and multimodel-based executions. System frameworks are grouped into the input and output interaction frameworks, the graphic interaction frameworks, the modelling frameworks, and the hybrid frameworks. Clinical validation procedures are ordered as three levels: geometrical validation, model behavior validation, and user acceptability/safety validation. The present review paper provides useful information to characterize how real-time medical simulation systems with soft-tissue deformations have been developed. By clearly analysing advantages and drawbacks in each system development aspect, this review can be used as a reference guideline for developing systems of soft-tissue simulations.

A study of real-time simulation of liver of virtual surgical robot based on biologically position-based dynamic model

2021 ◽  
pp. 1-16
Author(s):  
Dan Luo ◽  
Yu Zhang ◽  
Jia Li ◽  
Jisheng Li
Keyword(s):  
Soft Tissue ◽  
Real Time ◽  
Surgical Instruments ◽  
Organic Polymer ◽  
Tetrahedral Mesh ◽  
Virtual Surgery ◽  
Constraint Force ◽  
Real Time Simulation ◽  
Time Simulation ◽  
Spring Force

Virtual surgery robot can accurately modeling of surgical instruments and human organs, and realistic simulation of various surgical phenomena such as deformation of organic tissues, surgery simulation system can provide operators with reusable virtual training and simulation environment. To meet the requirement of virtual surgery robot for the authenticity and real-time of soft tissue deformation and surgical simulation in liver surgery, a new method is proposed to simulate the deformation of soft tissue. This method combines the spring force, the external force of the system, and the constraint force produced by the constraint function of the position-based dynamics. Based on the position-based dynamics, an improved three-parameter mass-spring model is added. In the calculation of the elastic force, the nonlinearity and viscoelasticity of the soft tissue are introduced, and the joint force of the constraint projection process and the constraint force of the position-based dynamics is used to modify mass points movement. The method of position-based dynamics based on biological characteristics, not only considers the biomechanical properties of biological soft tissue as an organic polymer such as viscoelasticity, nonlinearity, and incompressibility but also retains the rapidity and stability of the position based dynamic method. Through the simulation data, the optimal side length of tetrahedral mesh in the improved three-parameter model is obtained, and the physical properties of the model are proved. The real-time simulation of the liver and other organs is completed by using the Geomagic touch force feedback device, which proves the practicability and effectiveness of this method.

scholarly journals Real-time FEM for the Virtual Surgery of Soft Tissues

PAMM ◽  
2009 ◽  
Vol 9 (1) ◽  
pp. 173-174
Author(s):  
Christian Willberg ◽  
Ulrich Gabbert ◽  
Harald Berger
Keyword(s):  
Real Time ◽  
Soft Tissues ◽  
Virtual Surgery

In Situ Measurement and Modeling of Human Cadaveric Soft Tissue Mechanical Properties for Use in Real Time Surgical Simulation

2008 ◽  
Author(s):  
Yi-Je Lim ◽  
Dhannanjay Deo ◽  
Suvranu De
Keyword(s):  
Mechanical Properties ◽  
Real Time ◽  
Soft Tissues ◽  
Force Feedback ◽  
Mechanical Response ◽  
Surgical Simulation ◽  
Physical Models ◽  
Nonlinear Viscoelastic ◽  
External Forces ◽  
Surgery Simulator

Development of a realistic surgery simulator that delivers high fidelity visual and haptic (force) feedback, based on the physical models of soft tissues, requires the use of empirical data on the mechanical behavior of intra-abdominal organs under the action of external forces. Measurement of mechanical properties of soft tissues on live human patients presents significant risks, making the use of cadavers a logical alternative. In this paper we present techniques of measuring and modeling the mechanical response of human cadaveric tissue for the purpose of developing a “virtual cadaver” model. The major contribution of this paper is the development of physics-based models of soft tissues that range from linear elastic models to nonlinear viscoelastic models which are efficient for application within the framework of a real time surgery simulator.

scholarly journals Modeling of Tool-Tissue Interactions for Computer-Based Surgical Simulation: A Literature Review

2008 ◽  
Vol 17 (5) ◽  
pp. 463-491 ◽  
Author(s):  
Sarthak Misra ◽  
K. T. Ramesh ◽  
Allison M. Okamura
Keyword(s):  
Real Time ◽  
Force Feedback ◽  
Surgical Simulation ◽  
Surgical Instruments ◽  
Future Research ◽  
Surgical Simulators ◽  
Organ Deformation ◽  
Tissue Interactions ◽  
Operative Planning

Surgical simulators present a safe and potentially effective method for surgical training, and can also be used in robot-assisted surgery for pre- and intra-operative planning. Accurate modeling of the interaction between surgical instruments and organs has been recognized as a key requirement in the development of high-fidelity surgical simulators. Researchers have attempted to model tool-tissue interactions in a wide variety of ways, which can be broadly classified as (1) linear elasticity-based, (2) nonlinear (hyperelastic) elasticity-based finite element (FE) methods, and (3) other techniques not based on FE methods or continuum mechanics. Realistic modeling of organ deformation requires populating the model with real tissue data (which are difficult to acquire in vivo) and simulating organ response in real time (which is computationally expensive). Further, it is challenging to account for connective tissue supporting the organ, friction, and topological changes resulting from tool-tissue interactions during invasive surgical procedures. Overcoming such obstacles will not only help us to model tool-tissue interactions in real time, but also enable realistic force feedback to the user during surgical simulation. This review paper classifies the existing research on tool-tissue interactions for surgical simulators specifically based on the modeling techniques employed and the kind of surgical operation being simulated, in order to inform and motivate future research on improved tool-tissue interaction models.

Real-Time Simulation for Virtual Surgery in a PGD Framework

2012 ◽  
Author(s):  
Siamak Niroomandi ◽  
Felipe Bordeu ◽  
Iciar Alfaro ◽  
David Gonzalez ◽  
Adrien Leygue ◽  
...  
Keyword(s):  
Real Time ◽  
Soft Tissues ◽  
Computer Experiment ◽  
High Dimensional ◽  
Virtual Surgery ◽  
Real Time Simulation ◽  
Surgical Tool ◽  
Time Simulation ◽  
On Line ◽  
Additional Space

We analyze here the use of proper generalized decompositions (PGD) for real-time simulation of living soft tissues in virtual surgery environments. These tissues are usually modeled as hyperelastic solids, and therefore present important difficulties for their simulation under real-time constraints (i.e., feedback rates on the order of1 kHz). PGD techniques provide with physics-based meta-models without any prior computer experiment, that can be used on-line for the simulation under such severe constraints. These metemodels are constructed on the assumption of the problem to be multi-dimensional, with parameters as additional space dimensions. These parameters, in this case, are taken as the position of contact of surgical tool and organ, modulus of the contact force and orientation (a 9D problem). PGD techniques allow to solve efficiently these high-dimensional problems without the burden associated to the application of mesh-based techniques to these problems.

The Development of Minimally Invasive Surgery Simulation Training System Based on Virtual Reality Technology

2011 ◽  
Vol 403-408 ◽  
pp. 2300-2303
Author(s):  
Yan Fei Liu ◽  
Xiao Yu Jiang ◽  
Feng Ting Shen
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Real Time ◽  
Invasive Surgery ◽  
Simulation Training ◽  
Force Feedback ◽  
Training System ◽  
Virtual Surgery ◽  
Surgery Simulation ◽  
3 Dimensional

Minimally Invasive Surgery Simulation Training System based on VR technology is comprised of intelligent 3-Dimensional images VR software system and simulated surgical instrument with high perceptibility and high precision force feedback characteristics. Real time VR and simulated instrument with force feedback interact with the operator in real time, achieve high immersive virtual surgery scenario, and allows trainees to perform and improve the whole surgical procedures. By applying synchronized network video server and real-time communication server based on TRP/RTCP, the instructor can view all details of an operator's surgical procedure by a network terminal, and provide real time technical guidance. The system covers minimally invasive surgeries of digestive, urinary, gynecological, thoracic, pediatric , etc.

Radiological safety and assessment of the performance of X-ray systems in veterinary facilities

2020 ◽  
Author(s):  
S. Economides ◽  
C.J. Hourdakis ◽  
C. Pafilis ◽  
G. Simantirakis ◽  
P. Tritakis ◽  
...  
Keyword(s):  
Decision Making ◽  
Radiation Protection ◽  
Atomic Energy Commission ◽  
Atomic Energy ◽  
Regulatory Control ◽  
Continuous Training ◽  
X Ray ◽  
The Public ◽  
Radiological Safety ◽  
High Level

This paper concerns an analysis regarding the performance of X-ray equipment as well as the radiological safety in veterinary facilities. Data were collected from 380 X-ray veterinary facilities countrywide during the on-site regulatory inspections carried out by the Greek Atomic Energy Commission. The analysis of the results shows that the majority of the veterinary radiographic systems perform within the acceptable limits; moreover, the design and shielding of X-ray rooms as well as the applied procedures ensure a high level of radiological safety for the practitioners, operators and the members of the public. An issue that requires specific attention in the optimization process for the proper implementation of veterinary radiology practices in terms of radiological safety is the continuous training of the personnel. The above findings and the regulatory experience gained were valuable decision-making elements regarding the type of the regulatory control of veterinary radiology practices in the new radiation protection framework.

scholarly journals Graph-Based Construction of 3D Korean Giwa House Models

Buildings ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 68
Author(s):  
Mankyu Sung
Keyword(s):  
Data Structure ◽  
Computer Graphics ◽  
Real Time ◽  
Texture Image ◽  
Time Rate ◽  
Commercial Software ◽  
Spline Curve ◽  
High Level ◽  
Complicated Part ◽  
Different Parts

This paper proposes a graph-based algorithm for constructing 3D Korean traditional houses automatically using a computer graphics technique. In particular, we target designing the most popular traditional house type, a giwa house, whose roof is covered with a set of Korean traditional roof tiles called giwa. In our approach, we divided the whole design processes into two different parts. At a high level, we propose a special data structure called ‘modeling graphs’. A modeling graph consists of a set of nodes and edges. A node represents a particular component of the house and an edge represents the connection between two components with all associated parameters, including an offset vector between components. Users can easily add/ delete nodes and make them connect by an edge through a few mouse clicks. Once a modeling graph is built, then it is interpreted and rendered on a component-by-component basis by traversing nodes in a procedural way. At a low level, we came up with all the required parameters for constructing the components. Among all the components, the most beautiful but complicated part is the gently curved roof structures. In order to represent the sophisticated roof style, we introduce a spline curve-based modeling technique that is able to create curvy silhouettes of three different roof styles. In this process, rather than just applying a simple texture image onto the roof, which is widely used in commercial software, we actually laid out 3D giwa tiles on the roof seamlessly, which generated more realistic looks. Through many experiments, we verified that the proposed algorithm can model and render the giwa house at a real time rate.

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