scholarly journals Exclusive measuring system of constitutive parameters for living soft tissue and application to facial aging problems

2007 ◽  
Author(s):  
T. Tsuta ◽  
T. Iwamoto ◽  
T. Fujimura
Keyword(s):  
Soft Tissue ◽  
Measuring System ◽  
Facial Aging ◽  
Constitutive Parameters

scholarly journals Quantification of assembly forces during creation of head-neck taper junction considering soft tissue bearing: a biomechanical study

Arthroplasty ◽  
2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Toni Wendler ◽  
Torsten Prietzel ◽  
Robert Möbius ◽  
Jean-Pierre Fischer ◽  
Andreas Roth ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Work Experience ◽  
Soft Tissues ◽  
Force Sensor ◽  
Biomechanical Study ◽  
Measuring System ◽  
Wide Range ◽  
Head Neck

Abstract Background All current total hip arthroplasty (THA) systems are modular in design. Only during the operation femoral head and stem get connected by a Morse taper junction. The junction is realized by hammer blows from the surgeon. Decisive for the junction strength is the maximum force acting once in the direction of the neck axis, which is mainly influenced by the applied impulse and surrounding soft tissues. This leads to large differences in assembly forces between the surgeries. This study aimed to quantify the assembly forces of different surgeons under influence of surrounding soft tissue. Methods First, a measuring system, consisting of a prosthesis and a hammer, was developed. Both components are equipped with a piezoelectric force sensor. Initially, in situ experiments on human cadavers were carried out using this system in order to determine the actual assembly forces and to characterize the influence of human soft tissues. Afterwards, an in vitro model in the form of an artificial femur (Sawbones Europe AB, Malmo, Sweden) with implanted measuring stem embedded in gelatine was developed. The gelatine mixture was chosen in such a way that assembly forces applied to the model corresponded to those in situ. A study involving 31 surgeons was carried out on the aforementioned in vitro model, in which the assembly forces were determined. Results A model was developed, with the influence of human soft tissues being taken into account. The assembly forces measured on the in vitro model were, on average, 2037.2 N ± 724.9 N, ranging from 822.5 N to 3835.2 N. The comparison among the surgeons showed no significant differences in sex (P = 0.09), work experience (P = 0.71) and number of THAs performed per year (P = 0.69). Conclusions All measured assembly forces were below 4 kN, which is recommended in the literature. This could lead to increased corrosion following fretting in the head-neck interface. In addition, there was a very wide range of assembly forces among the surgeons, although other influencing factors such as different implant sizes or materials were not taken into account. To ensure optimal assembly force, the impaction should be standardized, e.g., by using an appropriate surgical instrument.

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.

115 Development of High Precision Laser Measuring System for Cross-Sectional Area of Soft Tissue

2001 ◽  
Vol 2001 (0) ◽  
pp. 37-38
Author(s):  
Hiroto INOUE ◽  
Hiroyuki FUJIKI ◽  
Michiaki KOBAYASHI ◽  
Setsuo MIURA ◽  
Kazunori YASUDA
Keyword(s):  
Soft Tissue ◽  
High Precision ◽  
Cross Sectional Area ◽  
Measuring System ◽  
Sectional Area ◽  
Cross Sectional

Quantifying Soft Tissue Loss in Facial Aging: A Study in Women Using Magnetic Resonance Imaging

2013 ◽  
Vol 39 (12) ◽  
pp. 1895-1902 ◽  
Author(s):  
Ashley Wysong ◽  
Tim Joseph ◽  
David Kim ◽  
Jean Y. Tang ◽  
Hayes B. Gladstone
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Soft Tissue ◽  
Tissue Loss ◽  
Resonance Imaging ◽  
Facial Aging ◽  
Soft Tissue Loss

311 Development of High Precision Laser Cross-Section Area Measuring System for Soft Tissue

2001 ◽  
Vol 2001.41 (0) ◽  
pp. 94-95
Author(s):  
Hiroyuki FUJIKI ◽  
Michiaki KOBAYASHI ◽  
Setsuo MIURA ◽  
Kazunori YASUDA
Keyword(s):  
Soft Tissue ◽  
Cross Section ◽  
High Precision ◽  
Measuring System ◽  
Cross Section Area ◽  
Section Area

The Impact of the Philtrum on Facial Attractiveness, Perioral Proportions, and Perceptions of Facial Aging

2020 ◽  
Author(s):  
Diogo Nunes ◽  
Gregor Bran
Keyword(s):  
Soft Tissue ◽  
Young Woman ◽  
State Of The Art ◽  
Facial Appearance ◽  
Upper Lip ◽  
Facial Aging ◽  
Population Demographics ◽  
Facial Proportions ◽  
The Impact ◽  
Caucasian Female

Abstract Background Lip enhancement continues to be one of the most popular facial procedures. State-of-the-art lip enhancement involves sculpting of perilabial soft tissue, in particular, the philtrum, but it is unclear how patients perceive their philtral contours. Objectives The aim of this study was to test the impact of the philtrum on attractiveness, and on the perception of facial proportions and age. Methods Respondents (1100, including 50 aesthetic specialists) were presented with 2 sets of identical portraits, 1 set of a young Caucasian female and 1 set of an aged Caucasian female, with 1 portrait in each set having an upper lip lacking any philtral contours. The respondents were asked to choose which upper lip was more attractive, appeared longer, and looked older. Rankings were analyzed according to population demographics. Results Overall, most respondents considered the young face (84%) and the aged face (68%) with philtral contours to be more attractive. Moreover, the majority of respondents (81%) considered the upper lip of the young face without a philtrum to appear longer in a craniocaudal orientation (67% for the aged image), and 67% of respondents described the image of the young woman with no philtral definition as appearing older (55% for the aged face with no philtrum). Conclusions This study confirms the authors’ hypothesis that the existence of philtral contours exerts a significant impact on perioral attractiveness, and that its absence can be related to a longer appearance of the upper lip as well as an older facial appearance.

NUMERICAL ANALYSIS OF THE FOOT IN HEALTHY AND DEGENERATIVE CONDITIONS

2017 ◽  
Vol 17 (06) ◽  
pp. 1750095
Author(s):  
CHIARA GIULIA FONTANELLA ◽  
ARTURO NICOLA NATALI ◽  
EMANUELE LUIGI CARNIEL
Keyword(s):  
Numerical Analysis ◽  
Soft Tissue ◽  
Mechanical Response ◽  
Biological Tissues ◽  
Tissue Mechanics ◽  
Specific Loading ◽  
Constitutive Parameters ◽  
Plantar Soft Tissue

The aim of this work is the development of a 3D numerical model of the foot that allows evaluating the influence of degenerative phenomena on the foot mechanical functionality. Such degenerative phenomena induce histo-morphological alterations and significant modification of the plantar soft tissue mechanical properties, as stiffening and lower damping capabilities. The finite element model of the foot is developed starting from the analysis of biomedical images. Different constitutive models define the mechanical response of the biological tissues. Because of the major role of plantar soft tissue in the here proposed analysis, a specific visco-hyperelastic constitutive formulation is provided considering the typical features of the tissue mechanics, as geometric and material non linearity, almost incompressible behavior and time-dependent phenomena. Constitutive parameters are identified by the analysis of experimental data from in vitro and in vivo mechanical tests, leading to the identification of a range of constitutive parameters for healthy and degenerative conditions. Numerical analyses are developed to investigate the influence of the progression of the degeneration on the distribution of stress and of strain within foot tissues during static standing. Numerical results show the increase of stress values with the appearance of degenerative conditions, showing the typical stiffening phenomenon. The mechanical response of the plantar soft tissue during specific loading condition and the influence of degenerative phenomena on foot mechanics can be evaluated with numerical analysis.

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