A shell finite element model of the pelvic floor muscles

Abstract

The pelvic floor gives support to the organs in the abdominal cavity. Using the dataset made public in (Janda et al. J. Biomech. (2003) 36(6), pp. 749–757), we have reconstructed the geometry of one of the most important parts of the pelvic floor, the levator ani, using NURB surfaces. Once the surface is triangulated, the corresponding mesh is used in a finite element analysis with shell elements.

Based on the 3D behavior of the muscle we have constructed a shell that takes into account the direction of the muscle fibers and the incompressibility of the tissue. The constitutive model for the isotropic strain energy and the passive strain energy stored in the fibers is adapted from Humphrey's model for cardiac muscles. To this the active behavior of the skeletal muscle is added.

We present preliminary results of a simulation of the levator ani muscle under pressure and with active contraction. This research aims at helping simulate the damages to the pelvic floor that can occur after childbirth.

Keywords:

• Pelvic floor
• Shell finite elements
• Humphrey's model

Acknowledgements

This work is part of the project “New materials, adaptive systems and their nonlinearities; modelling control and numerical simulation” carried out in the framework of the European community program “Improving the human research potential and the socio-economic knowledge base” (Contract N° HPRN-CT-2002-00284).

Notes

‡[email protected]

¶[email protected]

^‡ http://www.rhino3d.com

^† http://www.wbmt.tudelft.nl/mms/morph_data/

Additional information

Notes on contributors

D. d'Aulignac

‡ ‡[email protected]

E.B. Pires

¶ ¶[email protected]