K. Zheng (Exeter, GB)
University of Exeter College of Engineering, Mathematics, and Physical SciencesPresenter Of 1 Presentation
P251 - Mechanical Characterisation of Articular Cartilage by Combining Polarised Second Harmonic Generation Image and Finite-element Analysis
Abstract
Purpose
Current biphasic mechanical models of the articular cartilage in the literature, can well simulate the interaction between interstitial fluid and the porous-like solid matrix, the compressive strength provided by the non-fibrillar matrix and tissue swelling, and the tensile strength provided from the fibrillar matrix, but there is a research gap on how to mimic the heterogenous fibrillar orientation in the fibrillar matrix. Since polarised Second Harmonic Generation (pSHG) microscopy can provide a pixel-based fibrillar network orientation information, we developed a new method to incorporate such structural information into simulation. This will allow us establish a link between the structural parameters and the micromechanics of the tissue, to infer its functionality.
Methods and Materials
The non-fibrillar matrix is modelled as hyper-elastic, while the fibre in the fibrillar matrix has been modelled as linear elastic. The pixel-based information of fibril principal direction quantified from pSHG was assigned to each element of the FE model for simulating the heterogenous fibrillar network distribution. Tissue swelling was modelled by cooperating the pressure difference between external and internal osmotic pressures. Flow-dependent viscoelasticity was captured during the simulation of interaction of interstitial fluid and porous-structure.
Results
The pore pressure and fibril stress were simulated for both homogenous and heterogenous fibrilla orientation model, to investigate the influences of fibrillar heterogeneity on the local mechanical response. For both fibrillar stresses and por pressure, the general stress pattern is quite similar, except for some local regions, high pore pressure can be observed in the heterogenous model, which might indicate that such specific fibril orientation in this area alter the local mechanical behavior.
Conclusion
It is interesting to show that the fibril heterogeneity does affect the local mechanical behavior. Therefore, the current poro-hyper-elastic fibre-reinforced model cooperated with heterogeneous fibre orientation, can be used as an alternative approach to explore the mechanobiological process of articular cartilage.
Presenter Of 1 Presentation
P251 - Mechanical Characterisation of Articular Cartilage by Combining Polarised Second Harmonic Generation Image and Finite-element Analysis
Abstract
Purpose
Current biphasic mechanical models of the articular cartilage in the literature, can well simulate the interaction between interstitial fluid and the porous-like solid matrix, the compressive strength provided by the non-fibrillar matrix and tissue swelling, and the tensile strength provided from the fibrillar matrix, but there is a research gap on how to mimic the heterogenous fibrillar orientation in the fibrillar matrix. Since polarised Second Harmonic Generation (pSHG) microscopy can provide a pixel-based fibrillar network orientation information, we developed a new method to incorporate such structural information into simulation. This will allow us establish a link between the structural parameters and the micromechanics of the tissue, to infer its functionality.
Methods and Materials
The non-fibrillar matrix is modelled as hyper-elastic, while the fibre in the fibrillar matrix has been modelled as linear elastic. The pixel-based information of fibril principal direction quantified from pSHG was assigned to each element of the FE model for simulating the heterogenous fibrillar network distribution. Tissue swelling was modelled by cooperating the pressure difference between external and internal osmotic pressures. Flow-dependent viscoelasticity was captured during the simulation of interaction of interstitial fluid and porous-structure.
Results
The pore pressure and fibril stress were simulated for both homogenous and heterogenous fibrilla orientation model, to investigate the influences of fibrillar heterogeneity on the local mechanical response. For both fibrillar stresses and por pressure, the general stress pattern is quite similar, except for some local regions, high pore pressure can be observed in the heterogenous model, which might indicate that such specific fibril orientation in this area alter the local mechanical behavior.
Conclusion
It is interesting to show that the fibril heterogeneity does affect the local mechanical behavior. Therefore, the current poro-hyper-elastic fibre-reinforced model cooperated with heterogeneous fibre orientation, can be used as an alternative approach to explore the mechanobiological process of articular cartilage.