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Wyniki wyszukiwania dla: biomechanics
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Friction and flow around growing tissue in bioreactor. Proceedings of the Biomechanics 2003. Engineering Biomechanics - Biomechanics of Sport - Medical Biomechanics.
PublikacjaPrzedstawione zostały problemy teoretyczne związane z wyznaczaniem sił tarcia, współczynników tarcia, rozkładów wartości ciśnienia w warstwie przyściennej wytworzonej wokół hodowanej tkanki w bioreaktorze w trakcie opływu tej tkanki cieczami biologicznymi o właściwościach lepkosprężystych. Model Rivlina Ericksena lepkosprężystej cieczy biologicznej jest tu brany pod uwagę.
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Chosen aspects of muscle biomechanics
PublikacjaConsidering a striated skeletal muscle as a different properties mechanical system, one can understand series of important phenomena happening in a real muscle phenomenon of muscle: 1) force delivery to skeletal apparatus through tendons; 2) changing of exerted muscle belly mass distribution with regards to skeletal apparatus; 3) beginning drop of muscle force. A disregard of first phenomenon causes an impossibility to explain...
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Biomechanics of the medial meniscus in the osteoarthritic knee joint
PublikacjaBackground. Increased mechanical loading and pathological response of joint tissue to the abnormal mechanical stress can cause degradation of cartilage characteristic of knee osteoarthritis (OA). Despite osteoarthritis is risk factor for the development of meniscal lesions the mechanism of degenerative meniscal lesions is still unclear. Therefore, the aim of the study is to investigate the influence of medial compartment knee OA...
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Możliwości modelowania w biomechanice = Modelling capabilities in biomechanics
PublikacjaOmówiono mozliwości modelowania w biomechanice. Zaprezentowano główne kierunki badań biomechanicznych oraz metody modelowania, w tym najbardziej popularne oprogramowania do symulacji komputerowej modeli biomechanicznych ciała człowieka. Przedstawiono metody wykorzystania programów komputerowych CHARM, SIMM oraz AnyBody System do utworzenia biomechanicznych modeli ramienia człowieka.
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The Influence of Articular Cartilage Thickness Reduction on Meniscus Biomechanics
PublikacjaObjective Evaluation of the biomechanical interaction between meniscus and cartilage in medial compartment knee osteoarthritis. Methods The finite element method was used to simulate knee joint contact mechanics. Three knee models were created on the basis of knee geometry from the Open Knee project. We reduced the thickness of medial cartilages in the intact knee model by approximately 50% to obtain a medial knee osteoarthritis...
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Jaw biomechanics: Estimation of activity of muscles acting at the temporomandibular joint
PublikacjaThe aim of this study was to elaborate a method of estimation of activity of surface muscles acting at the temporomandibular joint of the healthy subjects by using a surface electromyography (EMG). The scope of this study involved testing chosen jaw motions (open, close, lateral deviation) and process of mastication occurring during eating food with different toughness (chewing gum, cereal and carrot) by using mixed sides, right...
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Biomechanics of Lumbar Spine Injury in Road Barrier Collision–Finite Element Study
PublikacjaLiterature and field data from CIREN database have shown that lumbar spine injuries occur during car crashes. There are multiple hypotheses regarding how they occur; however, there is no biomechanical explanation for these injuries during collisions with road safety barriers (RSBs). Therefore, the objective of this study was to investigate the mechanics of vertebral fractures during car collisions with concrete RSBs. The finite...
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Biomechanics of the front abdominal wall as a potential factorleading to recurrence with laparoscopic ventral hernia repair
PublikacjaThis study investigated the front abdominal wallto describe its elasticity in vivo and searched for elongationsthat possibly stretched an implanted mesh, therebycausing fixation failure and subsequent recurrence.To measure front abdominal wall elongations, amodel of fascia movements was created. Eight healthyvolunteers were measured during exercise to determine theextent of elongations in their front abdominal wall. Videoswere...
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EXPERIMENTS AND SIMULATIONS FOR LAPAROSCOPICVENTRAL HERNIA REPAIR IMPROVEMENT
PublikacjaThe authors conducted a wide experimental and numerical study in order to determine effective approaches in the laparoscopic VH repair. At first the study covered identification of mechanical properties of the abdominal fascia, implants, tacks and transabdominalsutures. Basis on these data, the one and two-dimensional mathematical models were formulated and a number of numerical static and dynamic analyses were carried out. Then...
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On implementation of fibrous connective tissues’ damage in Abaqus software
PublikacjaConnective fibrous tissues, such as tendons and ligaments, in humans and animals exhibit hyperelastic behaviour. The constitution of the material of these tissues is anisotropic due to the presence of the collagen fibres, where one family of fibres is the typical case. Traumatic events and/or aging may sometimes lead to the damage of the tissue. The study of motion of affected joints or limbs is usually not permitted in vivo. This...
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Degradation of metallic implants
PublikacjaPresence of metallic implants made of stainless steels, Co and Ti alloys is sometimes followed by some undesired allergic reactions and inflammatory processes and consequently the necessity of reimplantation.
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Influence of laser melting on surface layer properties of titanium alloy Ti6Al4V
PublikacjaIn time of rapid technology and medicine progress, implants are becoming more widely used in the human body, ranging from dental implants, stabilizing plates, screws, orthopaedic prostheses. For example, there are many types of hip prostheses used for hip replacement as well as various types of materials used for these orthopaedic prostheses. Properties of titanium alloys used in hip prostheses combined with good strength properties,...
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Physical and mathematical modelling of implant-fascia system in order to improve laparoscopic repair of ventral hernia
PublikacjaThis paper describes an investigation of biomechanical behaviour of hernia repair, which is focused on the selection of safe linking of certain type of implant with fascia in laparoscopic operation. The strength of various fixations of the implant to the fascia is analysed. Methods: The research is based on experimental observations of operated hernia model behaviour during a dynamic impulse load corresponding to post-operative...
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Muscle strength and endurance in high-level rock climbers
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Investigation of abdomen surface deformation due to life excitation: implications for implant selection and orientation in laparoscopic ventral hernia repair
PublikacjaVentral hernia is a common medical problem. Statistically there are around 10% recurrences of the sickness. The authors' former investigation proved edges of the hernia orifice displacements to be one of the factors causing recurrence. Thus, experimental investigation of the abdomen surface deformation due to some normal activities of people is studied.The extreme strains, their localization and directions are identified. The acquired...
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Tensile strength of a weave tendon suture using tendons of different sizes
PublikacjaThis study compared the maximum load, stress, elongation at failure and the mode of failure of three kinds of tendons most frequently used for tendon grafting and tendon transfers, using the Pulvertaftweave suture.
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Nanotubular Ti Oxide Layers for Enhancement of Bone-Implant Bonding and Bioactivity
PublikacjaAbstrakt artykułu pt. ''Nanotubular Ti Oxide Layers for Enhancement of Bone-Implant Bonding and Bioactivity''. The paper describes techniques to improve the bioactivity of titanium and ehnahnce the bone-implant bonding ability by the electrochemical anodization to fabricate titania nanotubular oxide layer.
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Preparation of the porous biomaterial based on titanium alloy for orthopaedic implants
PublikacjaObecnie tytan i jego stopy (Ti-6Al-4V lub Ti-13Nb-13Zr) są szeroko stosowane jako biomateriały dla implantów ortopedycznych. Stale prowadzone są badania nad ich najlepszą odpornością na korozję i zużycie ścierne oraz biozgodnością i bioaktywnością. Obecne badania również skoncentrowane są na projektowaniu, wytwarzaniu i właściwościach materiałów porowatych na podstawie na przykład stopu tytanu (Ti-13Nb-13Zr), które mogą być stosowane...
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Biocompatibility and bioactivity of bearing loaded metallic implants
PublikacjaPresentation of developed titanium alloy base composite materials possessing better biocompatibility, longer lifetime and bioactivity behavior for bearing loaded implants, e.g. hip joint and knee joint endoproshtesis.
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A Multi Rig Screening Test for Thin Ceramic Coatings in Bio-Tribological Applications
PublikacjaZaprezentowano metodę badań ogólnej charakterystyki tribologicznej cienkich powłok ceramicznych z wykorzystaniem równoległych testów na wielu stanowiskach o różnej konfiguracji styku powierzchni trących i przy ruchu o różnym charakterze (jednokierunkowym i posuwisto zwrotnym). Przedstawiono wyniki porównania przy pomocy jednoczesnej analizy wyników testów z różnych stanowisk; w wyniku testów uzyskano ranking powłok ze wskazaniem...
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In vivo performance of intraperitoneal onlay mesh after ventral hernia repair
PublikacjaBackground: Ventral hernia repair needs to be improved since recurrence, postoperative pain and other complications are still reported in many patients. The behavior of implants in vivo is not sufficiently understood to design a surgical mesh mechanically compatible with the human abdominal wall. Methods: This analysis was based on radiological pictures of patients who underwent laparoscopic ventral hernia repair. The pictures...
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The early failure of the gamma nail and the dynamic hip screw in femurs with a wide medullary canal. A biomechanical study of intertrochanteric fractures
PublikacjaBackground: Intertrochanteric fractures may occur in a bone with a wide medullary canal that may lead to significant mobility of a intramedullary nail, contrary to an extramedullary device. This study evaluates the Dynamic Hip Screw and the gamma nail in AO 31.A2.1 fractures in these circumstances. Methods: Synthetic femora with canals drilled to 18 mm were used. Five fixation types were examined: a 2 - hole and a 4 – hole Dynamic...
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Influence of meniscus shape in the cross sectional plane on the knee contact mechanics
PublikacjaWe present a three dimensional finite element analysis of stress distribution and menisci deformation in the human knee joint. The study is based on the Open Knee model with the geometry of the lateral meniscus which shows some degenerative disorders. The nonlinear analysis of the knee joint under compressive axial load is performed. We present results for intact knee, knee with partial and complete radial posterior meniscus root...
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Validation of Hydraulic Mechanism during Blowout Trauma of Human Orbit Depending on the Method of Load Application
PublikacjaThe more we know about mechanisms of the human orbital blowout type of trauma, the better we will be able to prevent them in the future. As long as the buckling mechanism’s veracity is not in doubt, the hydraulic mechanism is not based on equally strong premises. To investigate the correctness of the hydraulic mechanism’s theory, two different methods of implementation of the hydraulic load to the finite element method (FEM) model...
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The Influence of External Additional Loading on the Muscle Activity and Ground Reaction Forces during Gait
PublikacjaAsymmetrical external loading acting on the usculoskeletal system is generally considered unhealthy. Despite this knowledge, carrying loads in an asymmetrical manner like carrying on one shoulder, with one hand, or on the strap across the torso is a common practice. This study is aimed at presenting the effects of the mentioned load carrying methods on muscle activity assessed by using thermal field and ground reaction forces....
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Influence of geometry and annealing temperature in argon atmosphere of TiO2 nanotubes on their electrochemical properties
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Estimation of hydromechanical parameters of limb lymphedematous tissue with the use of chamber tests
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Comparison of two polymers PDO and PLLA/PCL in application of urological stent for the treatment of male urethral stenosis.
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Mechanical behaviour of the implant used in human hernia repair under physiological loads
PublikacjaIn laparoscopic operations of abdominal hernias some recurrences still take place, even when applying a surgical mesh. This is usually caused by a failure of the connection between the tissue and the implant. The study deals with the influence of an implant’s orientation on forces in joints, which connect the mesh to human tissues. In the paper, the implant is modelled as a membrane structure within framework of the Finite Element...
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Tribology of the cartilage cells in the intelligent bioreactor
PublikacjaW badaniach analityczno-numerycznych wyznaczone zostały pola prędkości przepływu lepkosprężystej, odżywczej nienewtonowskiej cieczy biologicznej, a także powstające siły tarcia w trakcie hodowli w warstwie granicznej wokoło powierzchni hodowanych komórek w bioreaktorach, stawach człowieka oraz w szczelinach mikrołożysk. Dodatkowo rozpatrywane będą przepływy potencjalne płynu stawowego z jamy stawowej, które odżywiają chrząstkę...
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Hydrodynamic pressure in micro-and nano bearing gap
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Method for assessing the dynamics and efficiency of diving fins
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Dynamic characteristics of interaperitoneal perfusion.
PublikacjaPrzedstawiono wyniki badań laboratoryjnych perfuzyjnego przepływu przez model jamy brzusznej człowieka. Szczególną uwagę zwrócono na techniczne aspekty modelu oraz wyników badań. Omówiono technikę pomiarową oraz przeanalizowano rezultaty pod kątem teorii przepływów przez zbiorniki i reaktory.
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Modelling and simulation of striated muscle and groups of muscles in arm-forearm system 2D
PublikacjaModel mięśnia szkieletowego poprzecznie prążkowanego został przedstawiony jako szeregowe połączenie aktywnych i pasywnych odcinków reologicznych. Zasymulowane zostały: skurcze pojedyncze, niecałkowity skurcz tężcowy, całkowity skurcz tężcowy. Model zespołu mięśni w układzie ramię-przedramię opisu-je zmianę kąta obrotu przedramienia względem nieruchomego ramienia. Pobudzając zginacze i prostowniki był zasymulowany obrót przedramienia.
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Estimation of flow for tissue perfusion of nutrient liquids in bioreactor.
PublikacjaPrzedstawione zostały problemy związane z wyznaczaniem pola prędkości w warstwie przyściennej opływanej tkanki miękkiej w bioreaktorze. Warunki brzegowe na powierzchni miękkiej tkanki o właściwościach porowatych zostały w niniejszej pracy sformułowane.
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Analysis of muscles behaviour : The computational model of muscle. -Part I
PublikacjaW artykule zaproponowano model obliczeniowy mięśnia szkieletowego, który potraktowano jako strukturę o złożonych i zróżnicowanych właściwościach mechanicznych. Szczegółowo opisano metodę identyfikacji tych właściwości. Ponadto określono sposób przeprowadzenia weryfikacji ilościowej i jakościowej zaproponowanego modelu. Za pomocą takiego obliczeniowego modelu mięśnia można łatwo określać siły w mięśniach, które należą do zespołu...
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Analysis of muscles behaviour. Part II. The computational model of muscles group acting on the elbow joint
PublikacjaThe purpose of this paper is to present the computational model of muscles' group describing the movements of flexion/extension at the elbow joint in the sagittal plane of the body when the forearm is being kept in the fixed state of supination/pronation. The method ofevaluating the muscle forces is discussed in detail. This method is the basis for the quantitative and qualitative verification of the proposed computational model...
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Application of muscle model to the musculoskeletal modeling
PublikacjaThe purpose of this paper is to investigate new fusiform muscle models. Each of these models treats a muscle as a system composedof parts characterized by different mechanical properties. These models explain the influence of differences in the stiffness of lateral parts and the degree of muscle model discretization. Each muscle model is described by a system of differential equations and a single integro-differential equation....
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Mechanical and structural investigations of wings of selected insect species
PublikacjaThis paper presents research and measurements leading to obtaining the Young’s modulus of wing bearing structures of selected insect species. A small testing machine intended for three-point bending and equipped with instruments registering low forces was constructed for the needs of the experiment. The machine was used to perform numerous bending tests of wings of three species of insects (obtained from a breeding farm): Attacus...
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The effective elastic properties of human trabecular bone may be approximated using micro-finite element analyses of embedded volume elements.
PublikacjaBoundary conditions (BCs) and sample size affect the measured elastic properties of cancellous bone. Samples too small to be representative appear stiffer under kinematic uniform BCs (KUBCs) than under periodicity-compatible mixed uniform BCs (PMUBCs). To avoid those effects, we propose to determine the effective properties of trabecular bone using an embedded configuration. Cubic samples of various sizes (2.63, 5.29, 7.96, 10.58...
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Enhancing rheological muscle models with stochastic processes
PublikacjaPurpose: Biological musculoskeletal systems operate under variable conditions. Muscle stiffness, activation signals, and loads change during each movement. The presence of noise and different harmonic components in force production significantly influences the behaviour of the muscular system. Therefore, it is essential to consider these factors in numerical simulations. Methods: This study aims to develop a rheological mathematical...
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Tensile and flexural moduli for human orbital wall bones – comparative study
PublikacjaThe main aims of the current research were: (1) to analyze in detail the tensile modulus and ultimate tensile strength (UTS) of orbital wall bones separately for the left and right orbit of the same cadaver and (2) to compare the obtained results with a flexural modulus of the left and right orbit reported earlier by A. C. van Leeuwen et al. [14]. A set of 54 specimens of orbital superior and/or medial walls harvested from 16 human...
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Modeling the debonding process of osseointegrated implants due to coupled adhesion and friction
PublikacjaCementless implants have become widely used for total hip replacement surgery. The long-term stability of these implants is achieved by bone growing around and into the rough surface of the implant, a process called osseointegration. However, debonding of the bone–implant interface can still occur due to aseptic implant loosening and insufficient osseointegration, which may have dramatic consequences. The aim of this work is to...
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Effect of pulse laser treatment at different process variables on mechanical behavior of carbon nanotubes electrophoretically deposited on titanium alloy
PublikacjaPurpose: Titanium and its alloys are widely used as biomaterials for long-term implants, but they are usually surface-modified due to their weak bioactivity and wear resistance. Laser processing was used to modify the surface layer, and elemental carbon was a component of the deposited coatings. This research aims to use a combination of both methods based on preliminary electrophoretic deposition of multi-wall carbon nanotubes...
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Mechanical behaviour of knit synthetic mesh used in hernia surgery
PublikacjaPurpose: There is a discussion in literature concerning mechanical properties and modelling of surgical meshes. An important feature of elastic modulus dependency on load history is taken into account in this paper, as implants are subjected to variable loading during human activity. The example of DynaMesh®-IPOM surgical implant is studied. Methods: The analysis is based on failure tension tests and cyclic loading and unloading...
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Deposition of phosphate coatings on titanium within scaffold structure
PublikacjaPurpose: Existing knowledge about the appearance, thickness, and chemical composition of phosphate coatings on titanium inside porous structures is insufficient. Such knowledge is important for the design and fabrication of porous implants. Methods: Metallic scaffolds were fabricated by selective laser melting of 316L stainless steel powder. Phosphate coatings were deposited on Ti sensors placed either outside the scaffolds or...
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Biological and mechanical properties of bone cement with nanoarticles - in vitro and in vivo research
PublikacjaDespite antibiotic preventive treatment both before and after implant implementation, the risks of infection are real. These infections develop at the implant surface a few months after inserting them into the body. To prevent the development of bacteria and reduce the risk of infection, implants coated with nanoparticles are used. The Mechanical Department of the Technical University of Gdansk carries out research into using bone...
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Behaviour of orthotropic surgical implant in hernia repair due to the material orientation and abdomen surface deformation
Publikacjarelation to the different range of typical deformations observed in different directions and zones of abdomen surface due to the patients’ life activities, has a significant influence on the extreme junction forces in the mesh–tissue connections and hence the repair persistence. The finite element model of the orthotropic implant was developed, and the junction forces in the connections of tissue and mesh were studied. The kinematical...
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Combined numerical and experimental approach to determine numerical model of abdominal scaffold
PublikacjaA proper junction of the prosthesis and the abdominal wall is important in successful hernia repair. The number of tacks should be balanced to assure appropriate mesh fixation and not to induce post-operative pain. Numerical simulations help to find this balance. The study is aimed at creating a proper numerical model of a knitted surgical mesh subjected to boundary conditions and load occurring in the abdominal cavity. Continuous,...
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Influence of energy absorbers on Malgaigne fracture mechanism in lumbar-pelvic system under vertical impact load
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