Comparison between 2D and 3D Simulation of Contact of Two Deformable Axisymmetric Bodies

2020 ◽  
Vol 21 (2) ◽  
pp. 123-133
Author(s):  
Marat Dosaev ◽  
Vitaly Samsonov ◽  
Vladislav Bekmemetev
Keyword(s):  
Soft Tissue ◽  
Soft Tissues ◽  
Tactile Sensor ◽  
3D Models ◽  
The Finite Element Method ◽  
Current Version ◽  
Local Stiffness ◽  
2D And 3D ◽  
Axisymmetric Bodies ◽  
Range Of Values

AbstractA portable pneumatic video-tactile sensor for determining the local stiffness of soft tissue and the methodology for its application are considered. The expected range of local elastic modulus that can be estimated by the sensor is 100 kPa–1 MPa. The current version of the device is designed to determine the characteristics of tissues that are close in mechanical properties to the skin with subcutis and muscles. A numerical simulation of the contact between the sensor head and the soft tissue was performed using the finite-element method. Both 2D and 3D models were developed. Results of experiments with device prototype are used for approval of adequacy of mathematical modelling in case of large deformations. Simulation results can be used to create soft tissue databases, which will be required to determine the local stiffness of soft tissues by the sensor. 2D model proved to be more efficient for the chosen range of values of local stiffness of soft tissues.

scholarly journals Soft Tissue Stability around Single Implants Inserted to Replace Maxillary Lateral Incisors: A 3D Evaluation

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
F. G. Mangano ◽  
F. Luongo ◽  
G. Picciocchi ◽  
C. Mortellaro ◽  
K. B. Park ◽  
...  
Keyword(s):  
Soft Tissue ◽  
South Korea ◽  
Soft Tissues ◽  
3D Models ◽  
Lateral Incisor ◽  
Engineering Software ◽  
3D Surface ◽  
Immediate Placement ◽  
Surface Models ◽  
3D Evaluation

Purpose. To evaluate the soft tissue stability around single implants inserted to replace maxillary lateral incisors, using an innovative 3D method.Methods. We have used reverse-engineering software for the superimposition of 3D surface models of the dentogingival structures, obtained from intraoral scans of the same patients taken at the delivery of the final crown (S1) and 2 years later (S2). The assessment of soft tissues changes was performed via calculation of the Euclidean surface distances between the 3D models, after the superimposition of S2 on S1; colour maps were used for quantification of changes.Results. Twenty patients (8 males, 12 females) were selected, 10 with a failing/nonrestorable lateral incisor (testgroup: immediate placement in postextraction socket) and 10 with a missing lateral incisor (controlgroup: conventional placement in healed ridge). Each patient received one immediately loaded implant (Anyridge®, Megagen, Gyeongbuk, South Korea). The superimposition of the 3D surface models taken at different times (S2 over S1) revealed a mean (±SD) reduction of 0.057 mm (±0.025) and 0.037 mm (±0.020) fortestandcontrolpatients, respectively. This difference was not statistically significant (p= 0.069).Conclusions. The superimposition of the 3D surface models revealed an excellent peri-implant soft tissue stability in both groups of patients, with minimal changes registered along time.

Design and Simulation of Micro Tactile Sensor for Stiffness Detection of Soft Tissue with Irregular Surface

2020 ◽  
Vol 18 (3) ◽  
pp. 200-209
Author(s):  
Ahmed Fouly ◽  
Ahmed M. R. FathEl-Bab ◽  
A. A. Abouelsoud ◽  
T. Tsuchiya ◽  
O. Tabata
Keyword(s):  
Soft Tissue ◽  
Soft Tissues ◽  
Tactile Sensor ◽  
Sensor Output ◽  
Irregular Surface ◽  
Tissue Stiffness ◽  
Tactile Sensors ◽  
Element Analysis ◽  
Detailed Design ◽  
Sensor Structure

Tactile sensors become an essential part of many applications in our life. Integrating tactile sensors with surgical tools used in MIS is significant to compensate for the shortage of touch feeling of soft tissues and organs comparing with traditional surgeries. This paper presents a detailed design of a micro tactile sensor for measuring the stiffness of soft tissue with an irregular surface. The sensor consists of five cantilever springs with different stiffness. A spring in the middle has a relatively low stiffness surrounded by 4 springs have relatively equal high stiffness to compensate for the soft tissue contact error in the longitudinal and lateral directions. Sensor parameters are selected to ensure high sensitivity and linearity with taking into consideration the cross-talk effect among the sensor springs tips. A detailed design of the sensor structure in the microscale is conducted based on some constraints related to MEMS fabrication. A finite element analysis (FEA) of the sensor structure is conducted to evaluate sensor structure performance using CoventorWare software. Then, an FEA for the piezo-resistors, as a signal transduction method, is conducted which maps the sensor output to an electrical signal. The results prove that the sensor can differentiate among different soft-tissue stiffness within the selected range independent of the applied distance between the sensor and the tissue with an error below 3% even with inclination angle between the sensor and the tissue ±3°. Furthermore, a linear performance has been achieved between the soft-tissue stiffness and the sensor output.

Prediction methods for soft tissue structures in forensic facial reconstruction: A review for reconstruction of nose, eyes, mouth and ears

2020 ◽  
Vol 6 (01) ◽  
Author(s):  
Bhavana Murjani ◽  
Sonali Kadam ◽  
Easwaran Ramaswami ◽  
Vijayalaxmi Nimma ◽  
Rohini Bhosale ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Soft Tissues ◽  
Facial Reconstruction ◽  
Facial Soft Tissue ◽  
Soft Tissue Thickness ◽  
The Face ◽  
Tissue Structures ◽  
Important Position ◽  
3D Methods ◽  
2D And 3D

Facial reconstruction is an art and science in the field of forensics which involves construction of a recognizable face on unknown skull remains. It appears as a, metaphorically speaking “shining beacon of hope” after everything else fails for identification of the remains. Both, 2D and 3D methods of facial reconstruction have been developed for this process. The database of facial soft tissue thickness based on gender, ethnicity and age, at certain bilateral and unilateral anatomical points on skull bones, lay foundation to the process of reanimating the facial profile of a deceased. Several imaging modalities have been used for the collection of this data, in addition to the cadavers and various guidelines have been given for the reconstruction of the soft tissues, however, to construct soft tissue structures like nose, eyes, mouth and ears which take an important position in determination of the facial features is still a tedious task. This process is being researched since a century and multiple guidelines for reconstruction of the soft tissue structures are available. The face plays out based on the method used; hence selection of an appropriate method is vital. This review encompasses the various methods/guidelines derived for the reconstruction of the nose, eyes, mouth and ears of the face. In addition to the traditional methods given by Gerasimov, Krogman, Prokopec and Ubelaker, George, etc. other newer methods have been mentioned. This review also highlights assessment studies performed using the said methods in populations other than the ones they were derived from.

A Novel Tactile Sensor Design for Stiffness Detection of Soft Tissues

2010 ◽  
Author(s):  
Ahmed M. R. Fath El Bab ◽  
Khaled I. E. Ahmed
Keyword(s):  
Finite Element ◽  
Soft Tissue ◽  
Simulation Model ◽  
Soft Tissues ◽  
Tactile Sensor ◽  
Sensor Design ◽  
Contact Conditions ◽  
Sensor Performance ◽  
Element Simulation ◽  
Different Tissues

A novel tactile sensor design for stiffness detection of soft tissues is proposed aiming to get output readings uninfluenced of the contact conditions. The sensor principle is based on the concept of applying two springs, with considerably different stiffnesses, to soft tissue for stiffness detection. The sensor consists of two coaxial diaphragms with contact mesa to work as two different springs. The sensor mesas are designed in circular shape to compensate the error caused by the pushing distances between the sensor and the soft tissue. A finite element simulation model is developed to investigate the sensor performance. The results show that the sensor can successfully distinguish between different tissues with close stiffnesses independently of the pushing distance between the sensor and the tissue. Moreover the sensor shows good output linearity when measure different tissue stiffnesses.

scholarly journals Parametrication of numerical simulation of drying process in atypicall condenzation lumber kiln

2004 ◽  
Vol 52 (1) ◽  
pp. 169-174
Author(s):  
Jiří Zejda ◽  
Petr Koňas
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Cross Section ◽  
3D Models ◽  
Computing System ◽  
Moisture Distribution ◽  
The Finite Element Method ◽  
Drying Process ◽  
Flow Temperature ◽  
2D And 3D

This work deal with modelling of the process of drying, air flow, temperature and moisture distribution in a condensation lumber kiln. This model was made and solved in the computing system ANSYS with the use of the finite element method. There are comparationes of the 2D and 3D models, shape of wood stacks and variability of their parameters (height, width, length, cross section) in the work. The flow velocity and orientation, pressure and temperature field were observed.

Imaging Features of Primary Tumors of the Hand

2020 ◽  
Vol 16 ◽  
Author(s):  
Filippo Boriani ◽  
Edoardo Raposio ◽  
Costantino Errani
Keyword(s):  
Soft Tissue ◽  
Soft Tissues ◽  
Epithelioid Sarcoma ◽  
Case Series ◽  
Malignant Neoplasm ◽  
Benign Tumors ◽  
Imaging Features ◽  
Primary Tumors ◽  
Therapeutic Decisions ◽  
Tumors Of The Hand

: Musculoskeletal tumors of the hand are a rare entity and are divided into skeletal and soft tissue tumors. Either category comprises benign and malignant or even intermediate tumors. Basic radiology allows an optimal resolution of bone and related soft tissue areas, ultrasound and more sophisticated radiologic tools such as scintigraphy, CT and MRI allow a more accurate evaluation of tumor extent. Enchondroma is the most common benign tumor affecting bone, whereas chondrosarcoma is the most commonly represented malignant neoplasm localized to hand bones. In the soft tissues ganglions are the most common benign tumors and epithelioid sarcoma is the most frequently represented malignant tumor targeting hand soft tissues. The knowledge regarding diagnostic and therapeutic management of these tumors is often deriving from small case series, retrospective studies or even case reports. Evidences from prospective studies or controlled trials are limited and for this lack of clear and supported evidences data from the medical literature on the topic are controversial, in terms of demographics, clinical presentation, diagnosis prognosis and therapy.The correct recognition of the specific subtype and extension of the tumor through first line and second line radiology is essential for the surgeon, in order to effectively direct the therapeutic decisions.

scholarly journals Techniques Used for Eye Gaze Interfaces and Survey

2015 ◽  
Vol 1 (6) ◽  
pp. 276
Author(s):  
Maria Rashid ◽  
Wardah Mehmood ◽  
Aliya Ashraf
Keyword(s):  
Eye Tracking ◽  
Eye Gaze ◽  
3D Models ◽  
Image Process ◽  
Usability Problems ◽  
Software Algorithms ◽  
Pupil Detection ◽  
Eye Movement Tracking ◽  
2D And 3D ◽  
Movement Tracking

Eye movement tracking is a method that is now-a-days used for checking the usability problems in the contexts of Human Computer Interaction (HCI). Firstly we present eye tracking technology and key elements.We tend to evaluate the behavior of the use when they are using the interace of eye gaze. Used different techniques i.e. electro-oculography, infrared oculography, video oculography, image process techniques, scrolling techniques, different models, probable approaches i.e. shape based approach, appearance based methods, 2D and 3D models based approach and different software algorithms for pupil detection etc. We have tried to compare the surveys based on their geometric properties and reportable accuracies and eventually we conclude this study by giving some prediction regarding future eye-gaze. We point out some techniques by using various eyes properties comprising nature, appearance and gesture or some combination for eye tracking and detection. Result displays eye-gaze technique is faster and better approach for selection than a mouse selection. Rate of error for all the matters determines that there have been no errors once choosing from main menus with eye mark and with mouse. But there have been a chance of errors when once choosing from sub menus in case of eye mark. So, maintain head constantly in front of eye gaze monitor.

scholarly journals Dirichlet absorbing boundary conditions for classical and peridynamic diffusion-type models

2020 ◽  
Vol 66 (4) ◽  
pp. 773-793 ◽  
Author(s):  
Arman Shojaei ◽  
Alexander Hermann ◽  
Pablo Seleson ◽  
Christian J. Cyron
Keyword(s):  
Boundary Conditions ◽  
Materials Science ◽  
Unbounded Domains ◽  
Diffusion Models ◽  
Absorbing Boundary Conditions ◽  
The Finite Element Method ◽  
Absorbing Boundary ◽  
Diffusion Type ◽  
2D And 3D ◽  
Accuracy And Stability

Abstract Diffusion-type problems in (nearly) unbounded domains play important roles in various fields of fluid dynamics, biology, and materials science. The aim of this paper is to construct accurate absorbing boundary conditions (ABCs) suitable for classical (local) as well as nonlocal peridynamic (PD) diffusion models. The main focus of the present study is on the PD diffusion formulation. The majority of the PD diffusion models proposed so far are applied to bounded domains only. In this study, we propose an effective way to handle unbounded domains both with PD and classical diffusion models. For the former, we employ a meshfree discretization, whereas for the latter the finite element method (FEM) is employed. The proposed ABCs are time-dependent and Dirichlet-type, making the approach easy to implement in the available models. The performance of the approach, in terms of accuracy and stability, is illustrated by numerical examples in 1D, 2D, and 3D.

scholarly journals Developing a Quantifying Device for Soft Tissue Material Prop-Erties around Lumbar Spines

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 67
Author(s):  
Song Joo Lee ◽  
Yong-Eun Cho ◽  
Kyung-Hyun Kim ◽  
Deukhee Lee
Keyword(s):  
Lumbar Spine ◽  
Soft Tissue ◽  
Young’S Modulus ◽  
Viscoelastic Properties ◽  
Soft Tissues ◽  
Young's Modulus ◽  
Strain Curve ◽  
Stress And Strain ◽  
Commercial Device ◽  
Tissue Material

Knowing the material properties of the musculoskeletal soft tissue could be important to develop rehabilitation therapy and surgical procedures. However, there is a lack of devices and information on the viscoelastic properties of soft tissues around the lumbar spine. The goal of this study was to develop a portable quantifying device for providing strain and stress curves of muscles and ligaments around the lumbar spine at various stretching speeds. Each sample was conditioned and applied for 20 repeatable cyclic 5 mm stretch-and-relax trials in the direction and perpendicular direction of the fiber at 2, 3 and 5 mm/s. Our device successfully provided the stress and strain curve of the samples and our results showed that there were significant effects of speed on the young’s modulus of the samples (p < 0.05). Compared to the expensive commercial device, our lower-cost device provided comparable stress and strain curves of the sample. Based on our device and findings, various sizes of samples can be measured and viscoelastic properties of the soft tissues can be obtained. Our portable device and approach can help to investigate young’s modulus of musculoskeletal soft tissues conveniently, and can be a basis for developing a material testing device in a surgical room or various lab environments.

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