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Synovial fluid. Rheology and modelling Anna Kucaba- P ietal Rzeszow University of Technology

Synovial fluid. Rheology and modelling Anna Kucaba- P ietal Rzeszow University of Technology Poland. purpose of the work. To examine whether the use of an isotropic micropolar model to describe the liquid crystal synovial fluid is appropriate

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Synovial fluid. Rheology and modelling Anna Kucaba- P ietal Rzeszow University of Technology

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  1. Synovial fluid. Rheology and modelling Anna Kucaba-Pietal RzeszowUniversity of Technology Poland

  2. purpose of thework • To examine whether the use of an isotropic micropolar model to describe the liquid crystal synovial fluid is appropriate • Performing calculations tribological size biobearings on the basis of the theory of micropolar fluids for physiological data and comparison with the results of clinical observations

  3. Biobearinghipjoint Synovial fluid coefficient of frictioncx~ 0.001-0.03, Itworks about 70 years Transfer the load from a few to 18MP cartilage

  4. cartilage

  5. Synovial Fluid 5

  6. Sodium Hyaluronate, Hyaluronan Made up of repeating glucuronic acid and N-acetylglucosamine subunits High molecular weight: 0.2 to 10 million Dalton Major component of synovial fluid Exhibits viscoelastic properties Synovial Fluid • Main Factors affecting the rheological properties: • a) Hyaluronic Acid concentation • c) Molecular weigh of Hyaluronic Acid • d) temperature 6

  7. HA concentrationeffect on Synovial fluid rheology własności lepkosprężyste – efekt Barusa efekt przędliwości The influence of HA concentration on viscosity coefficient of synovial fluid 7

  8. Rheumatic Diseases In normal joints synovial fluid shows higher elastic properties.For diseases such as Rheumatoid arthritis, seropositive and seronegative, it is observed to decrease in the elastic and viscous properties of synovial fluidIn the elderly peoples and competitive athletes, a decrease in viscosity and reduced HA chain length is observed.

  9. Perspectives • Pathophysiological significance of biofluid rheology • Develop an understanding of how the micro- and nano-structure of blood influences its rheology • Explore to use of rheological parameters in diagnostics and menagement of clinical disorders and inoptimisation of blood processing • Explore new methods of measurement suited for clinical application • Maintain new type apparatus for such measurements

  10. OThe mathematical description of the liquid crystal medium versus micropolarfluid model nlk = –nkl

  11. 50 mm 20 mm 5 mm 20 mm 2 mm 2 mm Cartilage - construction

  12. Cartilagesurfacewavinessexhibits The coefficient of friction during movement along (1) and perpendicular to Microgroove (2). (Kupchinov) Magn. X 300

  13. Synovial fluid - rheologicalproperties dynamic viscosity coefficient of a HA solution coefficient of dynamic viscosity of synovial viscoelasticproperties - Baruseffect

  14. Cartilage - the construction 50 mm 20 mm 5 mm 20 mm 2 mm 2 mm

  15. Model Rivlina-Ericksena gdzie: t –stress tensor p – pressure I – tensor jednostkowy, A1 i A2 – shear tensor Rivlina-Ericksena, h, a, b – materialconstants of synovial

  16. Micropolar fluid equations Tij = (-p +lV k,k)dij + m(Vi,j + V j,i) + k(V j,i - eijkWk) , Cij= d Wk,kdij + bWi,j + gWj,i .

  17. Micropolar fluid equations

  18. The dimensionless form of them.f. equations

  19. The calculated bearing capacity Wfor different lengths L of HA moleculespozaslaniaj synku na rysunkach polskie napisy Ten slajd proszę rozbi mi na dwa slajdy , tytul taki sam, Na jednym dwa z boku na drugim wykres. ·h = 40 mm, ·a = 0.04 m = R/2 ·U = 0.01 m/s Effect legthof HA molecules onload   N parameter N showing the synovial fluid concentrations of HA: L1, L2 - HA molecules long, L3, L4 - short molecules Lmin = h/lmin= 1000 Lmax= h/lmax = 90.

  20. HA concentrationeffect on Synovial fluid rheology

  21. Calculation of time approaching the surface of the bone sas a function of concentration and lenth of HA Effect of HA molecules on the surface of bone approaching time in biołożysku? Parameter N as a function of the synovial fluid: L1, L2 - HA molecules long, L3, L4 - short molecules

  22. Calculation of load capacity as a function of temperature Nośność stawu biodrowego w funkcji parametru Ndla pięciu wartości temperatury mazi

  23. Conclusions The calculation of the tribological joint quatitiesobtained under micropolar model applied to synovial fluid are qualitatively consistent with clinical observations. Mikropolarnyfluid model of synovial remains in compliance with confirmed experimentally LCD model synovial fluid both in terms of physics of liquid crystals, as well as mathematical description.Describes the synovial fluid phase transitions.

  24. Thankyou for yourattention

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