Dynamical analysis of lower abdominal wall in the human inguinal hernia

• Autores: Gerard Fortuny Anguera
• Directores de la Tesis: Antoni Susín Sánchez (dir. tes.)
• Lectura: En la Universitat Politècnica de Catalunya (UPC) ( España ) en 2009
• Idioma: inglés
• Tribunal Calificador de la Tesis: Amadeu Delshams i Valdés (presid.) , Antonio Garijo Real (secret.) , Isabel Navazo Álvaro (voc.) , Manuel Armengol Carrasco (voc.) , François Faure (voc.)
• Enlaces
  • Tesis en acceso abierto en: TDX
• Resumen

  • This PhD thesis aims to build a numerical simulator of the inferior abdominal wall, in order to determine the genesis and causes of the inguinal hernia, Thus, a model with real data on the region of human body (properly discretized) has been built that reproduces the dynamic properties of the various elements of the region allowing the simulation of the moment at which the hernia occurs.

    Muscular simulation in general, has became a secondary subjec regarding numerical simulation, because on many occasions the interest has been concentrated in the general properties of the muscle (so that the muscle is considered a single element) and not in a detailed study of each of the parts of the muscle. The field where simulation has possibly been more productive is the cardiac simulation because of the constant interest in creating models of the cardiac muscle and it is for this reason that the only detailed models that exist are those related to the cardiac muscle.

    The muscular fibre contraction was simulated using the Hill-Maxwell rehologic model presented by J. Bestel which it regulates the contraction and recovery by means of potential activation function u(t). This model is the first dynamic model in dimension one of a microscopic muscle level.

    Currently, there is much varying conjecture regarding the causes of hernias, despite this however, a detailed study of their genesis, has not been possible. This is because on the one hand, it is impossible to catch the moment in which a hernia is generated, and, on the other, there is a lack of sufficiently detailed models of the muscles involved.

    We present a dynamic model of the inferior abdominal wall with the active elements (the muscles) and the passive elements (fascias, ligaments and other tissues), so that a study can be made of the various physical and chemical aspects that generate hernias. The model reproduces the real dynamic of the area, as A. Keith and W.J. Lytle conjectured at the beginning of the past century and commonly accepted by surgery community.

    This is the first model which reproduces the real dynamic in the inguinal area, so that we can prove the existence of the two defence mechanisms (the shutter mechanism and the sphincter mechanism in the inguinal ring). With this muscular contraction model we can study several parameters that it have an important role in the inguinal hernia genesis and we can do an accurate study about risk elements in the hernia inguinal. This parameters (Young's modulus, Poison's coefficient or intraabdominal pressure, for instance) have an hypothetical and no proved effect in the genesis of inguinal hernias. This work, evaluate the real effect of several parameters in the lineal model and propose a non linear model for the muscular simulation.