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EN
The paper presents results of microscopic observations of selected porcelain bridges prepared on metallic base. The aim of microscopic observations was the identification of example wear types which have appeared during dental prosthetic bridges exploitation. The main attention was directed to wear forms that are quite often present in case of such prosthetic elements. The wear types comparative analysis was evaluated. The most frequent types of wear are: material's cracking, abrasive wear. Also, the metal corrosion and wear by dental plaque at prosthetic bridge surface were observed.
PL
Niniejszy artykuł traktuje o problematyce wspomagania sterowania systemami antropo-technicznymi na przykładzie układu człowiek-proteza. Zaprezentowano koncepcję rozwiązania napędu węzła kinematycznego sztucznego stawu łokciowego protezy kończyny górnej. Przedstawiono wytyczne i algorytm mechatronicznego wspomagania bioelektrycznego sterowania chwytakiem czynnym i stawem łokciowym. Jest to przyczynek do dalszych badań weryfikujących możliwość wspomagania nadążnego sterowania trzema niezależnym i ruchami protezy za pomocą sygnałów z dwóch par mięśni antagonistycznych. Tło pracy stanowi studium literatury dokonane pod kątem analizy i oceny uwarunkowań rozwoju inżynierii rehabilitacyjnej oraz badania możliwości mechatronicznego wspomagania protezy kończyny górnej w stosunku do rozwiązań występujących na rynku polskim. Dołączono również krótką dywagację na temat światowych tendencji rozwojowych w dziedzinie protetyki kończyny górnej.
EN
This paper deals with control of artificial limbs problems. The article presents the conception of the artificial elbow joint drive and instructions to design the mechatronical assistance of bioelectrically controlled artificial hand and elbow joint. The idea is a contribution to verify the possiblity of dynamic mode control of three independent motions with signals taken from two pairs of antagonictic muscles. The bibliographic study of rehabilitation engineering and reasearch of evolution of control modes applied to artificial limbs made in Poland is a backgroung to this article. There is included short discussion about evolution of world prosthetics.
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The paper presents selected issues relating to movable dentures with their general characteristics of fixings. Reference was made to the most importantmaterial-constructional aspects and the problems that arise with this type of solutions. In the work the method of durability and reliability evaluation and selection of materials for the kinematics connections of this type of structure was proposed.
EN
Simulation of the long term behavior of a metacarpal bonę with a prosthesis is presented with the help of an evolutive 3D finite element model taking into account "the stress słiielding" phenomena. The same model allows to improve the shape of the prosthesis.
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Content available remote Optimizing the shape of the prosthetic aortic leaflet valve
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EN
The object under study reported on in this paper was an aortic valve based on a natural aortic valve as the original. Simulations were carried out to examine the functioning of a valve which was loaded with varying pressure until a buckling of the leaflets and a fuli opening of the valve were observed. The aim of the study was the optimal choice of the geometrie and mechanical parameters for the class of construction assumed for analysis.
PL
Narząd wzroku jest jednym z najważniejszych zmysłów u człowieka warunkującym odbieranie ponad 90% bodźców zewnętrznych. Jego utrata lub uszkodzenie praktycznie eliminują człowieka ze społeczeństwa. Dotychczasowe próby naprawy czy też poprawy wzroku opierały się głównie na korekcji obrazu docierającego na siatkówkę. W przypadku uszkodzenia tej tkanki odbieranie światła jest niemożliwe. Najnowsze wyniki badań ukazują możliwości w zakresie wykonania protez tego narządu za pomocą układów fotoelektrycznych.
EN
The organ of sight is one of the most important senses in humans, conditioning the reception of over 90% of external stimuli. Its loss or damage virtually eliminates a man from society. Previous attempts to repair or improve eyesight were based mainly on the correction of the image reaching the retina. In the case of damage to this tissue, it is impossible to receive light. The latest research results show the possibilities in the field of prosthesis using photoelectric systems.
PL
Narząd wzroku jest jednym z najważniejszych zmysłów człowieka warunkującym odbieranie ponad 90% bodźców zewnętrznych. Jego utrata lub uszkodzenie praktycznie eliminują człowieka ze społeczeństwa. Dotychczasowe próby naprawy czy też poprawy wzroku opierały się głównie na korekcji obrazu docierającego na siatkówkę. W przypadku uszkodzenia tej tkanki odbieranie światła jest niemożliwe. Najnowsze wyniki badań ukazują możliwości w zakresie wykonania protez tego narządu za pomocą układów fotoelektrycznych.
EN
The organ of sight is one of the most important senses in humans, conditioning the reception of over 90% of external stimuli. Its loss or damage virtually eliminates a man from society. Previous attempts to repair or improve eyesight were based mainly on the correction of the image reaching the retina. In the case of damage to this tissue, it is impossible to receive light. The latest research results show the possibilities in the field of prosthesis using photoelectric systems.
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Content available remote Evolutionary programs in the optimization of cementless hip prosthesis
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EN
The optimal design of cementless hip prosthesis is investigated in the paper. Design variables are materials (represented by their Young's moduli) of the non-homogenous stem prosthesis, disposed in vertical layers. The minimisation of the interface stress function with constraints on the resorbed bone mass reaction is presented. A simplified two-dimensional FEM model of a stem-bone configuration is considered, enabling however to obtain essential characteristics of the stem-bone load-transfer mechanism. Evolutionary algorithm approach is applied to find the optimal solution.
PL
Narząd wzroku jest jednym z najważniejszych zmysłów u człowieka warunkującym odbieranie ponad 90% bodźców zewnętrznych. Jego utrata lub uszkodzenie praktycznie eliminują człowieka ze społeczeństwa. Dotychczasowe próby naprawy czy też poprawy wzroku opierały się głównie na korekcji obrazu docierającego na siatkówkę. W przypadku uszkodzenia tej tkanki odbieranie światła jest niemożliwe. Najnowsze wyniki badań ukazują możliwości w zakresie wykonania protez tego narządu za pomocą układów fotoelektrycznych.
EN
The organ of sight is one of the most important senses in humans, conditioning the reception of over 90% of external stimuli. Its loss or damage virtually eliminates a man from society. Previous attempts to repair or improve eyesight were based mainly on the correction of the image reaching the retina. In the case of damage to this tissue, it is impossible to receive light.The latest research results show the possibilities in the field of prostheses prosthesis using photoelectric systems.
EN
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.
PL
W pracy przedstawiono wyniki badań doświadczalnych pomiarów sił rekcji w zębach oporowych w odniesieniu do sił żucia działających na protezę. Na specjalnie skonstruowanym stanowisku badawczym złożonym z układu obciążającego tensometrycznego przetwornika siły poddano obciążeniu wybraną protezę i dokonano pomiaru sił przenoszonych przez zęby oporowe. Zastosowano dwa schematy obciążenia w dwóch wybranych miejscach na powierzchniach żujących uzupełnionych zębów w bliskim sąsiedztwie zęba oporowego. Analiza stanu obciążenia pozwoliła zmierzyć wartości sił reakcji pionowych oraz ocenić kierunki sił poziomych działających na zęby filarowe.
EN
The experimental studies of measuring of reaction forces on abutment teeth relative to mastication forces acting on a removable partial denture were carried out. A specially constructed experimental system consists of stand and strain gauges equipment, In this system loading was applied to a selected denture and forces transmitted by abutment teeth were measured. Two loads were applied in two selected places on the masticatory surfaces of denture teeth adjacent to the abutment teeth. The results of the study are presented in a table. The analysis of the load allowed to measure values of vertical reaction forces and to make conclucion about directions of horizontal forces acting on abutment teeth.
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Content available Idea protez bionicznych w nowoczesnej protetyce
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EN
Over the past decades, a tremendous progress has been made in creating artificial machines and systems. Breakthroughs in this field have been possible through the collaboration of scientists, biologists, computer scientists, engineers and patients. A particularly promising area is the invention of bionic artificial limbs as well as bionic ear and eye prostheses. The connection of the nervous system with a bionic prosthesis enables it to partly fulfill the functions of a real limb. This is an opportunity for a disabled person to live a fairly normal life. The article discusses the progress made in recent years in creating bionic prostheses and presents the requirements of bionic prostheses, their advantages, disadvantages, applied solutions and directions for their further development.
PL
Choroba krążków międzykręgowych jest to właściwie naturalny proces degeneracyjny, związany ze zużyciem i starzeniem się dysków. Tracą one swoją elastyczność i wytrzymałość na obciążenie statyczne i dynamiczne. Uszkodzenia dysku z obniżeniem jego wysokości, zmniejszenie szerokości otworów międzykręgowych dla korzeni i średnicy kanału kręgowego prowadzi do kompresji korzeni i ucisku rdzenia. Procesy zwyrodnieniowe w kręgosłupie przez ucisk na nerw lub rdzeń, wywołują ból, zdrętwienie, osłabienie czucia i siły mięśni, zburzenie funkcji fizjologicznych. Aktualnie najczęściej wykonywaną operacją leczniczą dyskopatii w zakresie kręgosłupa szyjnego jest discectomia (usunięcie uszkodzonego dysku) i fuzja sąsiednich trzonów materiałem własnym (kość) lub sztucznym (czop węglowy) z użyciem blachy stabilizującej, ta metoda pozwala na szybki powrót pacjentów do normalnego życia. Odtworzenie jednostki ruchowej z zastosowaniem sztucznego dysku daje także możliwości zachowania ruchu w tym segmencie jak też chroni sąsiednie dyski przed przeciążeniem jakie powstaje przy zespoleniu nieruchomym
EN
Degenerative Disc Disease is part of the natural process of growing older. As we age, our intervertebral discs lose their flexibility, elasticity, and shock absorbing characteristics. This process can cause several different symptoms, by nerve root and spinał cord compression leading to pain or numbness as well as motor skill dysfunctions. These symptoms result from the worn out discs not functioning as well as they once did. As they shrink, or change shape the space available for the nerve roots and the spinał cord may become compromised. While a fusion with an anterior cervical plate remains the standard of care, and allows most patients to return to symptom-free normal activities within a very short period of time, the artificial discs will potentially offer another option to patients who suffer from Degenerative Disc Disease. Reconstruction of a failed intervertebral disc with a functional disc prosthesis should offer the same benefits as fusion while simultaneously providing motion and thereby protecting the adjacent level discs from the abnormal stresses associated with fusion.
PL
W pracy przedstawiono wpływ ładunku elektrycznego na adhezję krwinek płytkowych i poziom białka całkowitego. Wyznaczono potencjał zeta protez nieelektryzowanych i elektretów w roztworach o różnych pH. Zbadano wpływ czasu na potencjał zeta krwi ludzkiej. Określono zachowanie się potencjału zeta na granicy proteza naczyń krwionośnych-krew w funkcji czasu.
EN
Presented work describes influence of charge on blood platelets adhesion and complete protein level. Zeta potential of prostheses and electrets in solutions with different pH was determined. The influence of time on zeta potential of human blood was examined. Also behavior of zeta potential in function of time between blood vessel prosthesis – blood was described.
15
Content available remote Wybór metod pomiarowych dla diagnostyki sztucznego serca
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PL
W niniejszym artykule zamieszczono analizę metod pomiarowych, możliwych do zastosowania w protezach sztucznego serca POLVAD (Polish Ventricular Assistant Device). Mechaniczne protezy służące do wspomagania serca rozwijane w Fundacji Rozwoju Kardiochirurgii w Zabrzu mają za zadanie wspomagać leczenie mięśnia sercowego u pacjentów ze zdiagnozowanymi chorobami serca i układu krwionośnego. Zastosowanie protezy wspomagającej pracę serca pozwala na znaczne przyspieszenie leczenia. Artykuł opisuje zagadnienia związane z wyborem bezinwazyjnej metody pomiarowej pozwalające na określenie ciśnienia krwi w określonych miejscach protezy sztucznego serca. Warunkiem koniecznym, jaki musi spełnić układ pomiarowy, jest całkowita separacja czujnika od środowiska krwistego. Wynika to z potrzeby unikania destrukcji składników krwi oraz powstawania zakrzepów. W pracy opisano dwie możliwe metody pomiarowe - systemy zbudowane przy wykorzystaniu folii piezoelektrycznej oraz metod optycznych.
EN
Methods for pressure measurement to be used in the POLVAD artificial heart prostheses are described in this paper. The mechanical prostheses used for heart support are developed by the Foundation of Cardiac Surgery Development in Zabrze. Their main purpose is to aid the heart muscle recovery of patients with cardiac problems. Use of the POLVAD prosthesis speeds up the healing process. The paper covers the recent research into the possible pressure sensing methods for use in the noninvasive blood pressure measurement in required places around the prosthesis. The main requirement for the developed methods is lack of contact with blood to avoid the destruction of blood elements and minimise influence on the blood flow. Two sensing methods are presented: one based on a fiber pressure sensor, the other on piezoelectric pressure measurements. The preliminary results are included, and choice of the best method for future development is pointed out.
EN
The purpose of the study was to analyze and compare retention characteristics of different stud attachments including a standard and two low profile attachments on two implant embedded test models. Methods: Three different stud attachment systems (Ball attachment and two different low profile stud attachments – Equator and Locator) were used in this study. Two dental implants were placed vertically into a custom-made acrylic resin block within a 22 mm distance. Strong and soft nylon inserts of each attachment system were tested using cyclic dislodgement test for 24 months simulation. Maximum forces during the test were recorded and 10 consecutive data at baseline, 1st to 24th months were analyzed. Repeated measures ANOVA and post-hoc Tukey’s test ( p  0.05) were used for statistical analysis. Results: Retentive forces of the tested attachments varied from 30.7 to 93.75 N at the baseline. The highest initial mean retention (93.75 N) was observed in Group LC (locator attachment with clear nylon inserts) and the lowest initial mean retention (30.7 N) was detected in both Group BO (ball attachment with orange nylon inserts) and Group EY (equator with yellow nylon inserts). After the 24 months simulation, locator groups illustrated more light retention than other tested attachment systems. Conclusions: All tested attachment systems showed a significant decrease in retention value at the end of the simulated period. The locator attachment had significantly higher reduction in retention values compared to other low profile stud attachment equator and ball attachment.
EN
This paper deals with next experimental measurement of mechanical properties of transtibial prosthesis. Prosthesis allows users standing and moving without of using others supporting devices. Therefore, patients can return back to social active life. Design and prosthesis properties decide about comfort, safeness and reliability of prosthesis. The article summarizes conclusions of preliminary experimental part, which was performed for real loading of straight walking, downhill walking and downstairs walking. The paper supports measuring published in Engineering Mechanics 2008 [1].
CS
Práce se zabývá experimentálním modelováním mechanických vlastností transtibiální protézy dolní končetiny. Protéza poskytuje uživateli možnost stoje a chůze bez nutnosti využití dalších pomůcek. Tímto se pacient vrací zpět do běžného a aktivního života. Její konstrukce a vlastnosti rozhodují o komfortu, bezpečnosti a spolehlivosti protézy. V příspěvku jsou shrnuty závěry přípravného experimentu, který si kladl za cíl ověřit měřící řetězec a porovnat naměřaná data s analytickým výpočtem.
EN
Purpose: The aim of the work was to manufacture a composite stem model consisting of carbon fibres (CF) and polyether ether ketone (PEEK) and to perform the surface strain and stress distributions in the stem-femoral bone model under compression loading. Methods: Composite stems differing in elasticity were prepared. Three types of composite stems having different arrangements of carbon fibre reinforcements (carbon fibre roving, carbon fibre sleeves and their combinations) in the polymer matrix were made. The stems were cementless fixed in the femoral bone model channel or with the use of the polymer bone cement (PMMA). Mechanical behaviour of composite stems under compression loading was compared with a metallic stem by strain gauge measurements at different parts of stem/bone model systems. Results: The values of stresses in the proximal part of the bone model for cemented and cementless fixations of the composite stem in the femoral bone channel were higher than those noted for the metallic stem. The increase in proximal bone stress was almost similar for both types of fixation of composite stems, i.e., cemented and cementless fixed stems. Conclusions: The optimal range of mechanical stiffness, strengths and work up to fracture was obtained for composite stem made of carbon fibre sleeves and carbon fibres in the form of roving. Depending on the elasticity of the composite stem model, an increase in the stress in the proximal part of femoral bone model of up to 40% was achieved in comparison with the metallic stem.
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Purpose: High level of successful maintenance of implants located in anterior part of mandible popularizes economical solutions of implant-retained soft tissue supported dentures including those using narrow mini-implants with small diameter - of 1.8-2.2 mm. Design/methodology/approach: FEM modeling analyses were used to determine distribution of mastication loads between mucous foundation and bone tissue surrounding mini-implants that have 1.8 mm diameter. Examined were two types of commercial solitary denture attachments, described as biomechanically compatible due to their rotational movements freedom or due to the additional pivoting mobility. Findings: In case of both types of attachments the most dangerous lateral implants loadings significantly exceed half of oblique mastication loads value. In mini-implants and bone tissue lateral forces generate a high level of stresses. Research limitations/implications: Analyses were carried out with assumed linear characteristics of materials. Denture-to-soft foundation, as well as implant-to-bone complete adherence was assumed. Practical implications: While using mini-implants it is crucial to carefully evaluate the condition of bone foundation, due to the risk of quick development of atrophic processes in case of insufficient bone parameters. In case of mini-implants very important is very high strength value level and surface quality, due to the fact that in case of diameter of 1.8mm there might occur local yielding and propagation of fatigue cracks. Originality/value: Commercial types of attachments do not deserve the name of mechanically biocompatible, as they do not allow for such significant reduction of overloading effects, as the non-commercial silicone attachments.
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