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Tytuł:
Biomechanical evaluation of a novel Limb Prosthesis Osseointegrated Fixation System designed to combine the advantages of interference-fit and threaded solutions
Autorzy:
Prochor, P.
Piszczatowski, Sz.
Sajewicz, E.
Powiązania:
https://bibliotekanauki.pl/articles/307287.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
FEM
biomateriały
implant
finite element analysis
direct skeletal attachment
implants
Opis:
Purpose: The study was aimed at biomechanical evaluation of a novel Limb Prosthesis Osseointegrated Fixation System (LPOFS) designed to combine the advantages of interference-fit and threaded solutions. Methods: Three cases, the LPOFS (designed), the OPRA (threaded) and the ITAP (interference-fit) implants were studied. Von-Mises stresses in bone patterns and maximal values generated while axial loading on an implant placed in bone and the force reaction values in contact elements while extracting an implant were analysed. Primary and fully osteointegrated connections were considered. Results: The results obtained for primary connection indicate more effective anchoring of the OPRA, however the LPOFS provides more appropriate stress distribution (lower stress-shielding, no overloading) in bone. In the case of fully osteointegrated connection the LPOFSs kept the most favourable stress distribution in cortical bone which is the most important long-term feature of the implant usage and bone remodelling. Moreover, in fully bound connection its anchoring elements resist extracting attempts more than the ITAP and the OPRA. Conclusions: The results obtained allow us to conclude that in the case of features under study the LPOFS is a more functional solution to direct skeletal attachment of limb prosthesis than the referential implants during short and long-term use.
Źródło:
Acta of Bioengineering and Biomechanics; 2016, 18, 4; 21-31
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An evaluation of the efficiency of endpoint control on the correction of scoliotic curve with brace : A case study
Autorzy:
Karimi, Mohammad
Rabczuk, Timon
Luthfi, Mauludin
Pourabbas, Babak
Esrafilian, Amir
Powiązania:
https://bibliotekanauki.pl/articles/949744.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
skolioza
FEM
metoda elementów brzegowych
scoliosis
brace
finite element analysis
boundary condition
Opis:
The use of braces is one of the conservative treatment approaches recommended for scoliotic subjects. However, the main question posted here is how to improve the efficiency of braces to control the scoliotic curve or to decrease its progression. The aim of this study was to evaluate the efficiency of various boundary conditions (endpoint control) of brace on the correction of scoliotic curves. Method: CT scan images of a scoliotic subject, with double lumbar and thoracic curves, was used to produce 3d model of spine. The correction of spine (decrease in scoliotic curves) was determined following the use of transverse (lateral-to-medial direction) and the combination of transverse and vertical (upward-directed force, traction) forces on spine in Abaqus software. The effects of pelvic fixation (pelvic basket of a brace) on both sides (basket enclosed pelvic in both sides), on one side (basket enclosed the pelvis in only one side), and fixation of lumbar (part of the brace encircled the lumbar area) were evaluated in this study. Results: The results of this study showed that the effect of vertical forces (traction) was more than that of transverse force. Moreover, the combination of vertical and transverse forces on lumbar and thoracic curves correction was more than that of other conditions (only transverse forces). The best correction was achieved with lumbar fixation and with combination of vertical and transverse forces. Conclusions: The use the combination of vertical and transverse forces may be suggested to correct the scoliotic curve. Moreover, the efficiency of lumbar fixation in frontal plane seems to be more than pelvic fixation to correct scoliotic curve. The outputs of this study can be used to design new braces for scoliotic subjects.
Źródło:
Acta of Bioengineering and Biomechanics; 2019, 21, 2; 3-10
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of the plate location used in clavicle fractures during shoulder abduction and flexion movements: a finite element analysis
Autorzy:
Calisal, E.
Ugur, L.
Powiązania:
https://bibliotekanauki.pl/articles/306467.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
obojczyk
złamanie
FEM
acromioclavicular joint
clavicle fractures
plate position
finite element analysis
Opis:
Plate fixation is a commonly used surgical method in clavicular fracture treatment. The main purpose of this treatment is making the painless shoulder girdle and bring the functions to the optimum level. Plate fixation position still remains controversial. We aimed to investigate the effect of the plate position in clavicle midshaft fractures during shoulder movements. Methods: A normal anatomical shoulder joint was modeled using computed tomography images. A fracture line was created on the clavicle. Plate was placed superior to the clavicle in group 1 and anterior in group 2. The impacts of joints, plates, screws, ligaments and clavicle have been shown during 150° flexion and abduction movements of the shoulder by finite element analysis. Analyzes were made non-linear using ANSYS (version 18) and the same boundary conditions were applied in all models. Results: The load values in the plate, screws, ligaments, and clavicle were higher in group 1 than group 2 during abduction and flexion movements. Especially the load on the ac ligament was excessive. Load value in the glenohumeral joint was found similar both groups. The load values in the flexion movement were higher than the abduction movement in both groups. Conclusions: Anterior clavicle plating provides less stress on material and shoulder girdle, compared to superior plating, during shoulder abduction and flexion movements.
Źródło:
Acta of Bioengineering and Biomechanics; 2018, 20, 4; 41-46
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of elliptical deformation of the acetabulum on the stress distribution in the components of hip resurfacing surgery
Autorzy:
Stempin, R.
Dragan, S. Ł.
Kulej, M.
Filipiak, J.
Dragan, S.
Powiązania:
https://bibliotekanauki.pl/articles/306854.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
alloplastyka stawu biodrowego
rozkład naprężeń
FEM
hip resurfacing
stress distribution
finite element analysis
Opis:
Hip resurfacing surgery is a matter of controversy. Some authors present very good late results of 99% survival outcomes. However, national records of implants point to the series of complications connected with biomechanical flaws of the implant. These results implicate the experimental research on biomechanical properties of HRS. The aim of the research was to define the nature of cooperation between the components of hip resurfacing surgery (HRS) and the influence of the deformation of acetabulum, the size of the implant and the nature of the bone surface on the stress distribution in the acetabulum and the femoral component. The calculations were run with the use of the finite element method (FEM), using the ANSYS bundle for this purpose. Four decrete models of the studied system were made: a model with the elements of the system connected with glue, a perfect spherical model with cooperating surfaces, a model reflecting an elliptical deformation of the acetabulum, and a model with different sizes of the implant. The results indicate that the stress values obtained for models with the ideally spherical acetabulum cannot cause significant deformation of cooperating implants. In the case of loads of the elliptically deformed acetabulum significant point stress concentrations can be observed in the spots of joint. The size of the acetabular and femoral components of HRS has influence on the stress concentration on the internal surface of the acetabulum as well as in the bone tissue surrounding the madrel of the femoral component. Moreover, physical properties of the base surface surrounding the HRS components have influence on the size of stress in the acetabulum and the femoral component.
Źródło:
Acta of Bioengineering and Biomechanics; 2017, 19, 4; 35-41
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of pullout strength in different designs of pedicle screws for osteoporotic bone quality using finite element analysis
Autorzy:
Yang, Shih-Chieh
Liu, Pao-Hsin
Tu, Yuan-Kun
Powiązania:
https://bibliotekanauki.pl/articles/306201.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
osteoporoza
cement
FEM
osteoporosis
cement augmentation
pedicle screw
pullout strength
finite element analysis
Opis:
The purpose of this study was to investigate pullout strength of three types of pedicle screws with and without cement augmentation in osteoporotic bone using finite element analysis. Methods: Twelve 3D finite element models were created to investigate the effect of pullout strength when comparing between pedicle screw types and bone cement clouds. The bottom side of bone block model was constrained and U-shape head was applied 1 mm in direction of longitudinal axis of pedicle screw to perform pullout resistance. The material properties of the FEA was set as linear elastic, homogenous, isotropic condition. The element sensitivity of convergence testing has been performed and variation of the sequential analytical results was less than 3%. Results: The results showed that the maximum total reaction force (133.8 N) was detected in the model of cannulated pedicle screw combined with a central pin with 4 ml cement augmentation, but, in contrast, the minimum total reaction force (106.8 N) was discovered in the model of cannulated pedicle screw without cement. A strong relationship (r = 0.9626) is found in comparison with the biomechanical results between pullout strength of sawbone testing and reaction forces of the FEA. Conclusions: The study concludes that the cannulated pedicle screw can not only provide an inner guider for cement flow and increase bending resistance (deflection effect) when a central pin is selected, but also can improve the pullout strength in the osteoporotic bone to add cement augmentation. The design of the cannulated pedicle screw is suggested for poor bone quality to change pullout failure.
Źródło:
Acta of Bioengineering and Biomechanics; 2019, 21, 3; 57-66
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Contact mechanics and wear simulations of hip resurfacing devices using computational methods
Autorzy:
Ali, M.
Mao, K.
Powiązania:
https://bibliotekanauki.pl/articles/307273.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
archard wear law
biotribology elbow
contact
finite element analysis
wear
biotribologia
kontakt
zużycie
Opis:
The development of computational and numerical methods provides the option to study the contact mechanics and wear of hip resurfacing devices. The importance of these techniques is justified by the extensive amount of testing and experimental work required to verify and improve current orthopaedic implant devices. As the demands for device longevity is increasing, it is as important as ever to study techniques for providing much needed orthopaedic hip implant solutions. Through the use of advanced computer aided design and the finite element method, contact analysis of hip resurfacing devices was carried out by developing both three-dimensional and twodimensional axisymmetric models whilst considering the effects of loading conditions and material properties on the contact stresses. Following on from this, the three-dimensional model was used in combination with a unique programme to develop wear simulations and obtain cumulative wear for both the acetabular cup and femoral head simultaneously.
Źródło:
Acta of Bioengineering and Biomechanics; 2014, 16, 2; 103-110
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fixation of distal fibular fractures: A biomechanical study of plate fixation techniques
Autorzy:
Marvan, J.
Horak, Z.
Vilimek, M.
Horny, L.
Kachlik, D.
Baca, W.
Powiązania:
https://bibliotekanauki.pl/articles/306556.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
analiza FEM
osteosynteza
złamanie kości
fibular fracture
finite element analysis
osteosynthesis
fracture fixation
fibula
Opis:
Ankle fractures are complex injuries with variable prognoses that depend upon many factors. The aim of the treatment is to restore the ankle joint biomechanical stability with maximum range of motion. Most ankle fractures are fibular fractures, which have a typical oblique fracture line in the distal fibula located in the area of the tibiofibular syndesmosis. The aim of this study was to simulate numerically several fixation techniques of the distal fibular fractures, evaluate their stability, determine their impact on surrounding tissue load, and correlate the results to clinical treatment experience. The following three models of fibular fracture fixation were used: (a) plate fixation with three screws attached above/below and lag screws, (b) plate fixation with two screws attached above/below and lag screws, and (c) three lag screws only. All three fracture fixation models were analyzed according to their use in both healthy physiological bone and osteoporotic bone tissue. Based on the results of Finite Element Analysis for these simulations, we found that the most appropriate fixation method for Weber-B1 fibular fractures was an unlocked plate fixation using six screws and lag screws, both in patients with physiological and osteoporotic bone tissue. Conversely, the least appropriate fixation method was an unlocked plate fixation with four screws and lag screws. Although this fixation method reduces the stress on patients during surgery, it greatly increased loading on the bone and, thus, the risk of fixation failure. The final fixation model with three lag screws only was found to be appropriate only for very limited indications.
Źródło:
Acta of Bioengineering and Biomechanics; 2017, 19, 1; 33-39
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of the piezoelectric thimble tactile device operating modes
Autorzy:
Bansevicius, R.
Dragasius, E.
Grigas, V.
Jurenas, V.
Mazeika, D.
Zvironas, A.
Powiązania:
https://bibliotekanauki.pl/articles/307079.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
skóra
wymuszenie harmoniczne
analiza elementów skończonych
tactile sensation
skin strain
harmonic excitation
finite element analysis
Opis:
A multifunctional device to transfer graphical or text information for blind or visually impaired is presented. The prototype using tactile perception has been designed where information displayed on the screen of electronic device (mobile phone, PC) is transferred by oscillating needle, touching the fingertip. Having the aim to define optimal parameters of the fingertip excitation by needle, the computational analysis of different excitation modes has been carried out. A 3D solid computational finite element model of the skin segment, comprising four main fingertip skin layers (stratum corneum, epidermis, dermis and hypodermis) was built by using ANSYS Workbench FEA software. Harmonic analysis of its stress–strain state under excitation with different frequency (up to 10000 Hz) and harmonic force (0.01 N), acting outer stratum corneum layer in normal direction at one, two or three points has been performed. The influence of the mode of dynamic loading of skin was evaluated (in terms of the tactile signal level) on the basis of the normal and shear elastic strain in dermis, where mechanoreceptors are placed. It is shown that the tactile perception of information, delivered by three vibrating pins, may be influenced by configuration of excitation points (their number and phase of loading) and the frequency of excitation.
Źródło:
Acta of Bioengineering and Biomechanics; 2014, 16, 3; 135-143
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Digital Image Correlation Techniques for Strain Measurement in a Variety of Biomechanical Test Models
Autorzy:
Hensley, S.
Christensen, M.
Small, S.
Archer, D.
Lakes, E.
Rogge, R.
Powiązania:
https://bibliotekanauki.pl/articles/307418.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
FEM
cyfrowa korelacja obrazów
wskaźnik naprężenia
DIC
finite element analysis
digital image correlation
strain gauges
Opis:
Purpose: Previous biomechanical studies have estimated the strains of bone and bone substitutes using strain gages. However, applying strain gages to biological samples can be difficult, and data collection is limited to a small area under the strain gage. The purpose of this study was to compare digital image correlation (DIC) strain measurements to those obtained from strain gages in order to assess the applicability of DIC technology to common biomechanical testing scenarios. Methods: Compression and bending tests were conducted on aluminum alloy, polyurethane foam, and laminated polyurethane foam specimens. Simplified single-legged stance loads were applied to composite and cadaveric femurs. Results Results: Showed no significant differences in principal strain values (or variances) between strain gage and DIC measurements on the aluminum alloy and laminated polyurethane foam specimens. There were significant differences between the principal strain measurements of the non-laminated polyurethane foam specimens, but the deviation from theoretical results was similar for both measurement techniques. DIC and strain gage data matched well in 83.3% of all measurements in composite femur models and in 58.3% of data points in cadaveric specimens. Increased variation in cadaveric data was expected, and is associated with the well-documented variability of strain gage analysis on hard tissues as a function of bone temperature, hydration, gage protection, and other factors specific to cadaveric biomechanical testing. Conclusions: DIC techniques provide similar results to those obtained from strain gages across standard and anatomical specimens while providing the advantages of reduced specimen preparation time and full-field data analysis.
Źródło:
Acta of Bioengineering and Biomechanics; 2017, 19, 3; 187-195
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling and structural analysis of skull/cranial implant: beyond mid-line deformities
Autorzy:
Bogu, V. P.
Kumar, Y. R.
Khanara, A. K.
Powiązania:
https://bibliotekanauki.pl/articles/307070.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
ciśnienie wewnątrzczaszkowe
FEM
implant
intracranial pressure
finite element analysis
beyond mid-line defect
fixation points
Opis:
Purpose: This computational study explores modelling and finite element study of the implant under Intracranial pressure (ICP) conditions with normal ICP range (7 mm Hg to 15 mm Hg) or increased ICP (>I5 mm Hg). The implant fixation points allow implant behaviour with respect to intracranial pressure conditions. However, increased fixation points lead to variation in deformation and equivalent stress. Finite element analysis is providing a valuable insight to know the deformation and equivalent stress. Methods: The patient CT data (Computed Tomography) is processed in Mimics software to get the mesh model. The implant is modelled by using modified reverse engineering technique with the help of Rhinoceros software. This modelling method is applicable for all types of defects including those beyond the middle line and multiple ones. It is designed with eight fixation points and ten fixation points to fix an implant. Consequently, the mechanical deformation and equivalent stress (von Mises) are calculated in ANSYS 15 software with distinctive material properties such as Titanium alloy (Ti6Al4V), Polymethyl methacrylate (PMMA) and polyether-ether-ketone (PEEK). Results: The deformation and equivalent stress results are obtained through ANSYS 15 software. It is observed that Ti6Al4V material shows low deformation and PEEK material shows less equivalent stress. Among all materials PEEK shows noticeably good result. Conclusions: Hence, a concept was established and more clinically relevant results can be expected with implementation of realistic 3D printed model in the future. This will allow physicians to gain knowledge and decrease surgery time with proper planning.
Źródło:
Acta of Bioengineering and Biomechanics; 2017, 19, 1; 125-131
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The comparison of density-elastic modulus equations for the distal ulna at multiple forearm positions : a finite element study
Autorzy:
Neuert, M. A. C.
Austman, R. L.
Dunning, C. E.
Powiązania:
https://bibliotekanauki.pl/articles/307226.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
finite element analysis
density modulus relationship
biomechanics
ulna
implant
experimental validation
analiza elementów skończonych
biomechanika
Opis:
The accuracy of an empirically derived density-modulus equation for bone depends upon the loading conditions and anatomic site of bone specimens used for experimentation. A recent study used FE modeling to compare the ability of three density-modulus relationships to predict strain during bending in neutral forearm rotation in the distal ulna; however, due to the inhomogeneous nature of these FE models, the performance of each equation is not necessarily consistent throughout forearm rotation. This issue is addressed in the present study, which compares the performance of these equations in pronation and supination. Strain gauge data were collected at six discreet locations of six ulna specimens loaded in bending at 40° of pronation and supination. Three FE models of each specimen were made, one for each density-modulus relation, and the strain output compared to the experimental data. The equation previously shown to be most accurate in predicting ulnar strain in neutral forearm rotation was also most accurate in pronation and supination. These results identify this one equation as the most appropriate for future FE analysis of the ulna (including adaptive remodeling, and further show that isotropic and inhomogeneous FE bone models may provide consistent results in different planes of bending.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 3; 37-43
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biomechanical comparison of a transiliac internal fixator and two iliosacral screws in transforaminal sacral fractures: a finite element analysis
Autorzy:
Salasek, M.
Jansova, M.
Křen, J.
Pavelka, T.
Weisova, D.
Powiązania:
https://bibliotekanauki.pl/articles/306399.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
analiza MES
stabilizator
biomechanika
finite element analysis
transiliac internal fixator
iliosacral screw
pelvic ring
transforaminal fracture
Opis:
Purpose: Vertically unstable sacral transforaminal fractures can be stabilized with a transiliac internal fixator (TIFI) or two iliosacral screws (IS). This study was designed to compare stiffness between TIFI and IS. Methods: Using CT images finite element model of the pelvis was developed. Denis II type fracture was simulated and fixed either with TIFI or two IS. The sacral base was loaded vertically (250–500 N), displacement magnitudes on medial and lateral fracture surface and the maximum bone stress were calculated. The intact pelvis was used as a reference. Stiffness was determined by linear regression of load and displacement, computed stiffness ratio %. The von Mises stress was expressed as % ratio, evaluation of colour mapping was made. Results: The mean stiffness ratio medially in TIFI was 75.22%, in IS 46.54% ( p = 0.00005), laterally in TIFI 57.88%, in IS 44.74% ( p = 0.03996). The von Mises stress ratio of TIFI was 139.27%, of IS 565.35% ( p < 0.00001). Conclusions: Significantly higher stiffness and lower stress were found in TIFI model. TIFI provides a lower risk of over-compression of the fracture line in comparison with IS. TIFI thus exhibits superiority for fixation of transforaminal fractures, particularly with comminutive zone.
Źródło:
Acta of Bioengineering and Biomechanics; 2015, 17, 1; 39-49
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling and stress analyses of a normal foot-ankle and a prosthetic foot-ankle complex
Autorzy:
Ozen, M.
Sayman, O.
Havitcioglu, H.
Powiązania:
https://bibliotekanauki.pl/articles/306591.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
3D modeling
finite element analysis
prosthetic foot-ankle complex
modelowanie 3D
proteza
analiza elementów skończonych
Opis:
Total ankle replacement (TAR) is a relatively new concept and is becoming more popular for treatment of ankle arthritis and fractures. Because of the high costs and difficulties of experimental studies, the developments of TAR prostheses are progressing very slowly. For this reason, the medical imaging techniques such as CT, and MR have become more and more useful. The finite element method (FEM) is a widely used technique to estimate the mechanical behaviors of materials and structures in engineering applications. FEM has also been increasingly applied to biomechanical analyses of human bones, tissues and organs, thanks to the development of both the computing capabilities and the medical imaging techniques. 3-D finite element models of the human foot and ankle from reconstruction of MR and CT images have been investigated by some authors. In this study, data of geometries (used in modeling) of a normal and a prosthetic foot and ankle were obtained from a 3D reconstruction of CT images. The segmentation software, MIMICS was used to generate the 3D images of the bony structures, soft tissues and components of prosthesis of normal and prosthetic ankle-foot complex. Except the spaces between the adjacent surface of the phalanges fused, metatarsals, cuneiforms, cuboid, navicular, talus and calcaneus bones, soft tissues and components of prosthesis were independently developed to form foot and ankle complex. SOLIDWORKS program was used to form the boundary surfaces of all model components and then the solid models were obtained from these boundary surfaces. Finite element analyses software, ABAQUS was used to perform the numerical stress analyses of these models for balanced standing position. Plantar pressure and von Mises stress distributions of the normal and prosthetic ankles were compared with each other. There was a peak pressure increase at the 4th metatarsal, first metatarsal and talus bones and a decrease at the intermediate cuneiform and calcaneus bones, in prosthetic ankle-foot complex compared to normal one. The predicted plantar pressures and von Misses stress distributions for a normal foot were consistent with other FE models given in the literature. The present study is aimed to open new approaches for the development of ankle prosthesis.
Źródło:
Acta of Bioengineering and Biomechanics; 2013, 15, 3; 19-27
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bone conduction stimulation of the otic capsule: a finite element model of the temporal bone
Autorzy:
Borkowski, Paweł
Marek, Piotr
Niemczyk, Kazimierz
Lachowska, Magdalena
Kwacz, Monika
Wysocki, Jarosław
Powiązania:
https://bibliotekanauki.pl/articles/306896.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
FEM
kośc skroniowa
ucho wewnętrzne
bone conduction
finite element analysis
temporal bone
otic capsule
cochlea
inner ear
Opis:
Bone conduction stimulation applied on the otic capsule may be used in a conductive hearing loss treatment as an alternative to the bone conduction implants in clinical practice. A finite element study was used to evaluate the force amplitude and direction needed for the stimulation. Methods: A finite element model of a female temporal bone with a precisely reconstructed cochlea was subjected to a harmonic analysis assuming two types of stimulation. At first, the displacement amplitude in the form of air conduction stimulation was applied on the stapes footplate. Then the force amplitude was applied on the otic capsule in the form of bone conduction stimulation. The two force directions were considered: 1) the primary direction, when a typical opening is performed during mastoidectomy, and was coincident with the axis of an imaginary cone, inscribed in the opening, and 2) the direction perpendicular to the stapes footplate. The force amplitude was set so that the response from the cochlea corresponded to the result of air conduction stimulation applied on the stapes footplate. Results: The amplitude and phase of vibration and the volume displacement on the round window membrane were considered as well as vibrations of the basilar membrane, spiral lamina, and promontory. Conclusions: The cochlear response was comparable for the two types of stimulation. The efficiency of bone conduction stimulation depended on the force direction. For the primary direction, the force was a few times smaller than for the direction perpendicular to the stapes footplate.
Źródło:
Acta of Bioengineering and Biomechanics; 2019, 21, 3; 75-86
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of middle ear disorder in round-window stimulation using a finite element human ear model
Autorzy:
Zhou, Kai
Liu, Houguang
Yang, Jianhua
Zhao, Yu
Rao, Zhushi
Yang, Shanguo
Powiązania:
https://bibliotekanauki.pl/articles/307472.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
implant
symulacja
FEM
middle ear implant
round-window stimulation otosclerosis
otitis media
hearing loss
finite-element analysis
Opis:
The aim of this work was to study the effect of middle ear disorder on round window (RW) stimulation, so as to provide references for the optimal design of RW stimulation type middle ear implants (MEIs). Methods: A human ear finite-element model was built by reverse engineering technique based on micro-computed tomography scanning images of human temporal bone, and was validated by three sets of comparisons with experimental data. Then, based on this model, typical disorders in otosclerosis and otitis media were simulated. Finally, their influences on the RW stimulation were analyzed by comparison of the displacements of the basilar membrane. Results: For the otosclerosis, the stapedial abnormal bone growth severely deteriorated the equivalent sound pressure of the RW stimulation at higher frequencies, while the hardening of ligaments and tendons prominently decreased the RW stimulation at lower frequencies. Besides, among the hardening of the studied tissues, the influence of the stapedial annular ligament’s hardening was much more significant. For the otitis media, the round window membrane (RWM)’s thickening mainly decreased the RW stimulation’s performance at lower frequencies. When the elastic modulus’ reduction of the RWM was considered at the same time especially for the acute otitis media, it would raise the lower-frequency performance of the RW stimulation. Conclusions: The influence of the middle ear disorder on the RW stimulation is considerable and variable, it should be considered during the design of the RW stimulation type MEIs.
Źródło:
Acta of Bioengineering and Biomechanics; 2019, 21, 1; 3-12
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
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