Wyniki wyszukiwania - Biblioteka Nauki

1

Experimental and numerical analysis of urological stents

100%

Kajzer W. , Marciniak J.

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2007

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tom Vol. 28, nr 5

297-300

EN

Purpose: In order to evaluate the characteristic changes of the stents' diameters in function of the elongation (during elastic expansion) the biomechanical tests were carried out. The numerical analysis of the selected forms of urological stents was performed. The numerical results were compared with the experimental ones. Design/methodology/approach: The urethral stent commonly used in clinical practice was analyzed. Two types of research were carried out: experimental-in order to determine the displacement characteristic of the stent, and numerical (by means of the finite element method)-in order to evaluate stresses and strains in the stent. Findings: The comperative analysis of the obtained experimantal and numerical results showed good correlation, that proves the proper selection of the modeling conditions, and boundary conditions adequate to the real object. Research limitations/implications: The limitations were connected with the necessity of simplifications applied to the numerical model of the urological stent, and also with the difficulties caused by the established boundary conditions. Practical implications: The self-expanding stents analyzed in the work are implants for which the change of the diameter causes the significant change of the length. Due to the fact, the very important issue during implantation of this type of stent is the appropriate positioning in the narrowed part of urethra. The worked out characteristics allows to determine the length of the implant for the given diameter. Originality/value: The work presents the dispacement characteristics of the stent obtained on the basis of the experimental and numerical tests. The correlation of the obtained results is also presented.

2

Biomechanical analysis of plates used in treatment of pectus excavatum

100%

Krauze A. , Marciniak J. , Marchacz A.

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2007

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tom Vol. 28, nr 5

301-304

EN

Purpose: The paper presents computer simulation results of displacement, strain and stresses in the plate used in treatment of the pectus excavatum. Design/methodology/approach: The numerical analysis was performed for selected models of the stabilizing plates made of the Cr-Ni-Mo stainless steel (AISI 316L) and Ti-6Al-4V ELI alloy. Findings: The displacement, strain and stress analyses showed the diverse results depending on the plates geometry and the properties of the applied metallic biomaterial. The numerical analysis shows that stresses in plates didn't exceed the yield point: for the stainless steel R p0,2 min=690 MPa and Ti-6Al-4V ELI - Rp 0,2min =895 MPa. Research limitations/implications: The limitations were connected both with the necessity of simplifications applied to the numerical model and with the established boundary conditions. Practical implications: The obtained results are the basis for the stabilizing plate optimization to ensure favorable conditions for the pectus excavatum treatment. Originality/value: The work presents the displacement-strain-stress characteristics obtained on the basis of the numerical analysis.

3

Biomechanical analysis of the intervertebral disc implant using the finite element method

100%

Kajzer W. , Kajzer A. , Pindycki I.

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tom Vol. 15, nr 3(45)

57--66

EN

Dysfunctions of the vertebral column belong to a group of civilisation diseases and they affect approximately 80% of population. The underlying cause is modern (sedentary) lifestyle, low locomotive activity of people and frequent motor vehicle and sports accidents. Despite civilisation’s progress, no injury prophylactics or prevention of dysfunctions of the vertebral column have been introduced. The key element influencing function of the vertebral column is the intervertebral disc. It enables multidimensional movements and constitutes a basic connective element between the joints of the vertebral column. It also enables performing basic daily activities. Acting as a “damper”, it cushions vibrations and transmits loads between the vertebrae. One of the diseases affecting the intervertebral disc is discopathy. This is the most common degenerative disease, which can be treated by both conservative and surgical treatment. After removal of the damaged disc, it can be replaced by an adequate implant, which will assume its function. The implant will be expected to restore the vertebral column motor function, as well as to eliminate the pain resulting from compression of the spine caused by the damaged disc. This paper presents a biomechanical analysis using the finite element method for the L2-L3 vertebrae system with natural intervertebral disc, and the L2-L3 – implant of the intervertebral disc system. Two cases of the system vertebrae-implant were analysed which differed in the placement of the artificial disc in the intervertebral space. Within the conducted analysis, the state of displacement, strain and stress of reduced analysed systems and their individual elements was determined. A comparative analysis of the results and calculations was performed, also conclusions and observations were formulated, constituting a starting point for building more advanced calculation models and further analyses of such implants.

4

FEM analysis of compression screws used for small bone treatment

75%

Kajzer W. , Kajzer A. , Marciniak J.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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tom Vol. 33, nr 2

189-196

EN

Purpose: The paper presents results of numerical analysis in metatarsal bone „I” - compression screws system. The aim of the work was determined stresses, strain and displacement in the inserted screws. Design/methodology/approach: Metatarsal bone „I” was selected to researches. The analysis was carried out on the metatarsal bone „I” - compression screws system. The influence of the loads and displacements on the bone - screws system on the results of numerical analyses was analyzed. In order to carry out calculations, 2 models of diverse mechanical properties of screw - Ti-6Al-4V alloy - model 1, stainless steel (Cr-Ni-Mo) - model 2 and two load steps were selected. Findings: The analyses showed the difference in displacements, strains and stresses depending on the selected mechanical properties screws and the way of loads. Research limitations/implications: The limitations were connected with simplification of numerical model of femur as well as with the selected boundary conditions. Two difference way of loads metatarsal bone „I” - compression screws system: 1_force F = 500 N, 2_ displacement l = 1 mm were applied. Practical implications: The obtained results can be useful in clinical practice. They can be applied in selection of stabilization methods or rehabilitation as well as in describing the biomechanical conditions connected with type of bone fracture obtained from medical imaging. Originality/value: Stress-strain-displacement characteristics of metatarsal bone „I” - compression screws system, obtained from the numerical analysis were presented in the work.

5

Modern 3D Technology used for the Evaluation of Motorsports Drivers

75%

Skublewska-Paszkowska M. , Łukasik E. , Smołka J. , Kwiatkowski M.

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tom Vol. 12, no 1

17--26

EN

The article presents selected modern 3D technologies (a motion capture system, forceplates) that can be used to examine the biomechanics of motorsports drivers. The aim of this paper is to prove the following thesis:“modern 3D technologies allow for precise and objective biomechanical analysis of motorsports drivers as a complement to psychomotor tests” based on the preliminary research. Three motorsports drivers participated in this study.

6

FEM used in improvement of quality of medical devices

75%

Ziębowicz B. , Ziębowicz A. , Szkodny J.

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tom Vol. 41, nr 1-2

172-179

EN

Purpose: The fundamental aim of this research was to determine the biomechanical characteristics of the medical bed made of carbon steel and an assessment of its stability. To define the biomechanical characteristics of the bed design, the finite element method (FEM) was applied. Additionally, the risk analysis was conducted according to the directives of ISO 14971 standard. Design/methodology/approach: The research was carried out on the typical rehabilitation bed. To define the biomechanical characteristics of this equipment, the finite element method was applied. Geometric model of medical bed, was discretized by means of SOLID 95 element. Appropriate boundary conditions imitating phenomena in the real system with appropriate accuracy were established. The aim of biomechanical analysis was calculation of displacements and stresses in the bed’s construction elements in a function of the applied loading. In order to carry out calculations, 3 models of diverse variants of loading were selected – safe working load - model 1, transverse stability - model 2 and longitudinal stability - model 3. Findings: The analyses showed the difference in displacements, strains and stresses in the characteristic points depending on the selected loading. That also helped to determine maximal loading causing the exceeding of the yield stress of the bed’s components. Research limitations/implications: The limitations were connected with simplification of numerical model of femur as well as with the selected boundary conditions. Practical implications: The obtained results can be useful in the designing process (modification of requirements regarding design and construction, as well as materials used in the production of the device, and reduction of risk as far as possible to the patient). They prove that 3D geometrical analysis works quite well for assistive medical devices design. Originality/value: Stress-strain-displacement characteristics of the medical bed’s elements, obtained from the numerical analysis were presented in the work.

7

FEM analysis of expandable intramedullary nails in healthy and osteoporotic femur

63%

Kajzer W. , Kajzer A. , Marciniak J.

Journal of Achievements in Materials and Manufacturing Engineering

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2009

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tom Vol. 37, nr 2

563-570

EN

Purpose: The paper presents the results of numerical analysis of expandable intramedullary nail – femur system in different states of healing. The aim of the research was to determine displacements, deformations and stresses occurring in a bone depending on the age of the patient and the extent level of osteoporosis. Design/methodology/approach: A femur was selected to numerical analysis. The analysis concerned the influence of the load and torsion of the system on the obtained results of displacements, deformations and reduced stresses. In order to make calculations, four models with different mechanical properties were chosen: model 1: femur with mechanical properties corresponding with a femur of a patient at the age of 16, model 2: with mechanical properties corresponding with a femur of a patient at the age of about 28, model 3: with mechanical properties corresponding with a femur of a patient at the age of about 20 and at the age of 50 to 65 years old and model 4: with mechanical properties corresponding with a femur of a patient at the age above 70 or with osteoporosis. For the chosen model of intramedullary nail, mechanical properties of titan alloy Ti-6Al-4V were used. Two load steps were analyzed: load step 1 in which simple axial load with a value ranging from 250 up to 1000 N simulating patient standing on one leg was used, and load step 2 – a torsion analyzing loads that the nail is exposed to while walking. Findings: Conducted analysis of the system showed the difference in displacements, deformations and reduced stresses depending on assumed mechanical properties of femur and load step of the system. Research limitations/implications: The limitations were connected with the necessity of simplifying the assumptions, which were associated with limitations caused by boundary conditions. In researches 4 forces loading the femur axially were used: 1: force F = 250N, 2: with force F = 500N, 3: with force F= 750N and 4: with force F = 1000N and 5 values of angle displacement of the femur head were assumed: 1: angle displacement ö = 1°, 2: ö = 5°, 3: ö = 10°, 4: ö = 15°, 5: ö = 20°. Practical implications: Obtained results can be applied in selection of stabilization methods of bone fragments and in forecasting biomechanical conditions depending on the age of patient and the state of his general conditions of bones. Originality/value: The paper presents the displacement-deformation-stress characteristics of femur - expandable intramedullary nail system, using the Finite Elements Method (FEM) in the analysis.

8

Analiza biomechaniczna obciążenia w kończynie dolnej podczas jazdy konnej

63%

Sobuś M. , Iwaniec M. , Frontczak A. , Łagan S.

Aktualne Problemy Biomechaniki

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2011

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tom z. 5

137--142

PL

W niniejszym referacie podjęto próbę analizy wpływu długości strzemion w jeździe konnej na obciążenia powstające w kończynie dolnej. Wraz ze zmianą długości strzemion zmienia się kąt zgięcia nogi w stawie kolanowym oraz skokowym.

EN

In this publication we would like to analyse how length of the stirrups effects on loads in the lower limb. The longer stirrups are the bigger knee and ankle angles are. In horse riding there are some kinds of rider‟s positions, which are connected with discipline. Dressage rider„s seat is different than jumping or race seat, so we would like to analyse these differences. For example the long stirrups of the dressage rider allow for a long leg. But the short stirrups of a jockey allow the rider to stay over the galloping horse's center of balance and allow the horse to reach the maximum possible speed.

9

Biomechaniczna analiza wypadku samochodowego z zastosowaniem urządzenia typu HANS podpierającego głowę oraz odcinek szyjny kręgosłupa kierowcy

63%

Burkacki M. , Joszko K. , Gzik M.

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tom z. 7

17--22

PL

Celem pracy było dokonanie analizy w środowisku MADYMO wypadku samochodu rajdowego z zastosowaniem urządzenia HANS podpierającego głowę oraz odcinek szyjny kręgosłupa kierowcy. Stworzono model odzwierciedlający warunki panujące w samochodzie rajdowym, który został użyty do symulacji zderzenia przy przyspieszeniu 45G. Na podstawie otrzymanych wyników można stwierdzić, iż system HANS ogranicza urazowość głowy oraz odcinka szyjnego kręgosłupa podczas wypadku. Wpływa on na zmniejszenie siły działającej na odcinek szyjny kręgosłupa, ugięcie w odcinku szyjnym kręgosłupa oraz ugięcie klatki piersiowej.

EN

The aim of this study was to analyze a rally car accident in MADYMO software with use of the HANS device supporting head and cervical spine of the driver. Created model reflects the construction and equipment of a rally car which was used to simulate a 45G accident. Based on the results it can be said that the HANS system reduces trauma of the head and cervical spine during accident. It also reduces force affecting cervical spine, deflection of the cervical spine and chest deflection.

10

Analiza biomechaniczna układu wiertło chirurgiczne - kość udowa

63%

Paszenda Z. , Basiaga M.

Aktualne Problemy Biomechaniki

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2009

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tom z. 3

181--186

PL

Zasadniczym celem prezentowanej pracy była analiza biomechaniczna układu wiertło chirurgiczne - kość udowa w warunkach symulujących proces wiercenia w kości. Opracowano model geometryczny wiertła chirurgicznego o zróżnicowanej geometrii ostrza (2κ1 = 90° i 2κ2 = 120°) oraz krążka symulującego kość udową. Obliczenia przeprowadzono dla wiertła wykonanego ze stali X39Cr13. Efektem zrealizowanej analizy było wyznaczenie stanu odkształceń i naprężeń zredukowanych w części roboczej wiertła w funkcji obciążenia siłą F = 20-100 N i prędkością obrotową n = 2000 obr/min.

EN

The aim of the work was determination of biomechanical analysis of a surgical drill - bone system in simulated conditions of drilling in a bone. Geometrical models of the surgical drill of diverse geometry of the edge (2κ1 = 90° and 2κ2 = 120°) and the disc simulating femur were worked out. Calculations were carried out for the drill made of martensitic Steel (X39Cr13). The effect of numerical analysis was determination of strains and stresses in working part of the drill as a functional of the applied loading F = 20-100 N and rotational speed n = 2000 rpm.

11

Numerical and experimental analysis of spine’s transpedicular stabilizer

63%

Kiel M. , Marciniak J. , Basiaga M. , Szewczenko J. , Kus W. , Kokot G. , Wadek T.

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tom Vol. 41, nr 1-2

124-130

EN

Purpose: The aim of the work was a numerical and experimental analysis of spine’s transpedicular stabilizer on lumbar part of spine. The result of the analysis was determination of displacements of the stabilizers’ elements. Design/methodology/approach: To define numerical characteristic of the lumbar spine – transpedicular spine stabilizer system, the finite element method was applied. Geometrical models of lumbar part of spine and transpedicular stabilizer were discretized by SOLID95 element. The boundary conditions imitating phenomena in real system with appropriate accuracy were established. The experimental analysis was carried out for spine’s transpedicular stabilizers which were implanted on lumbar part of pig spine. The analysis was realized by means of testing machine MTS Insight with the use of videoextensometer. Numerical and experimental analysis were carried out for stabilizer made of stainless steel Cr-Ni-Mo. System was loaded by uniaxial compression with forces from 50 N to 1600 N. Findings: The result of analysis was calculation of relative displacements of the transpedicular stabilizer in a function of the applied loading; F = 700 - 1600 N for numerical model and F = 50 - 1600 N for experimental model. Research limitations/implications: The results of numerical analysis for transpedicular stabilizer obtained by finite element method were used to determine a construction features of the stabilizer, and to select mechanical properties of metallic biomaterial. The calculation of displacements for stabilizer show that the proposed type of stabilizer enables correct stabilization of spine. Practical implications: Both results of numerical and experimental analysis showed correct selection of mechanical properties of metallic biomaterial which were used to made the proposed type of transpedicular stabilizer. Originality/value: Advantageous results of analysis showed that the type of stabilizer may be used in clinical practice.

12

Biomechaniczna analiza wchodzenia na schody oraz badania stabilograficzne pacjentów z zaburzeniami neurologicznymi

63%

Tejszerska D. , Michnik R. , Jurkojc J. , Guzik-Kopyto A. , Michalik K. , Kmiotek A. , Rycerski W.

Aktualne Problemy Biomechaniki

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2010

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tom z. 4

249--254

PL

W pracy przedstawiono biomechaniczną analizę wchodzenia po schodach oraz badania stabilograficzne pacjentów ze schorzeniami neurologicznymi. W badaniach analizowano kinematykę oraz wartości sił reakcji podłoża podczas wchodzenia po schodach. Wielkości kinematyczne wyznaczono za pomocą systemu APAS. Pomiarów sił reakcji podłoża dokonano za pomocą platform dynamometrycznych firmy Kistler. Badania doświadczalne objęły grupę 8 osób z zaburzeniami neurologicznymi. Badania zrealizowano w Górnośląskim Centrum Rehabilitacji w Reptach.

EN

Biomechanical analysis of climbing the stairs and stability of patients having neurological disorders is presented in the paper. Analysis of kinematics and ground reactions was carried out for climbing the stairs. Kinematic quantities were determined by means of the APAS system. Ground reactions were measured with the use of the Kistler platform. Eight patients took part in the research. All measurements were carried out in the Silesian Center of Rehabilitation “Repty”.

13

Stabilizacja stawu barkowego wg koncepcji metody Bobath u osób z niedowładem połowiczym po udarze mózgu - analiza biomechaniczna

51%

Borkowska A. , Dobrowolna P. , Hagner W.

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tom z. 2

19--26

PL

Terapia pacjentów z niedowładem połowiczym po udarze mózgu powinna przebiegać według ustalonych zasad, bezboleśnie i prowadzić do uzyskania jak największej funkcjonalności m.in. kończyny górnej. Przeprowadzona analiza biomechaniczna ma na celu zwrócenia szczególnej uwagi na pozycje stawu barkowego podczas coraz częściej stosowanych ćwiczeń wg koncepcji metody Bobath. Potwierdza również słuszność i ważność stabilizacji barku poprzez aproksymację w okresie wiotkim porażenia, aby zapobiegać jego podwichnięciu i bolesności, co utrudniłoby a nawet uniemożliwiłoby proces usprawniania.

EN

Therapy of patients with hemiparesis after cerebral stroke should be conducted due to strict methods, in painless manner leading to the highest possible functionning of upper limb. The aim of biomechanical analysis was to pay attention on shoulder joint positions during commonly used exercises based on Bobath method. Analysis also confirmed significance and importance of shoulder joint stabilization by approximation during limp period of paralysis to prevent pain and sprain which can make the rehabilitation impossible.