Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: intervertebral discs

Sortuj według:

Ogranicz wyniki do:

Elastic constants influence on the L4-L5-S1 annuli fibrosus behavior, a probabilistic finite element analysis

Jaramillo H. E., Garcia J. J.

Acta of Bioengineering and Biomechanics

2017

Vol. 19, no. 4

3--12

A probabilistic finite element (FE) analysis of the L4-L5 and L5-S1 human annulus fibrosus (AF) was conducted to obtain a better understanding of the biomechanics of the AF and to quantify its influence on the range of motion (ROM) of the L4-L5 and L5-S1 segments. Methods: The FE models were composed of the AF and the upper and lower endplates. The AF was represented as a continuous material composed of a hyperelastic isotropic Yeoh matrix reinforced with two families of fibers described with an exponential energy function. The caudal endplate was fully restricted and 8 Nm pure moment was applied to the cranial endplate in flexion, extension, lateral flexion and axial rotation. The mechanical constants were determined randomly based on a normal distribution and average values reported. Results: Results of the 576 models show that the ROM was more sensitive to the initial stiffness of the fibers rather than to the stiffening coefficient represented in the exponential function. The ROM was more sensitive to the input variables in extension, flexion, axial rotation and lateral bending. The analysis showed an increased probability for the L5-S1 ROM to be higher in flexion, extension and axial rotation, and smaller in lateral flexion, with respect to the L4-L5 ROM. Conclusions: An equation was proposed to obtain the ROM as a function of the elastic constants of the fibers and it may be used to facilitate the calibration process of the human spine segments and to understand the influence of each elastic constant on the ROM.

Badanie tribologiczne implantów sztucznych dysków kręgosłupa

Gierzyńska-Dolna M., Lijewski M., Wiśniewski T., Magda J.

Tribologia

2011

nr 6

87-97

W artykule omówiono metody leczenia dysfunkcji kręgosłupa za pomocą implantowania sztucznych krążków międzykręgowych. Wskazano na materiałowe i konstrukcyjne wymagania, które powinien spełniać implant. Podano wyniki badań tribologicznych prowadzonych na symulatorze kręgosłupa zaprojektowanym i wykonanym w Instytucie Obróbki Plastycznej w Poznaniu.

The article discusses treatments for spinal dysfunction by the implantation of artificial intervertebral discs focusing on the material and structural requirements to be fulfilled by the implant. The final results of tribological tests were conducted on the spine simulator designed and built at the Institute for Metal Forming Institute in Poznan.