A comparative study of hyperelastic constitutive models for colonic tissue fitted to multiaxial experimental testing

Puértolas, S. (Universidad de Zaragoza) ; Peña, E. (Universidad de Zaragoza) ; Herrera, A. (Universidad de Zaragoza) ; Ibarz, E. (Universidad de Zaragoza) ; Gracia, L. (Universidad de Zaragoza)

Resumen: For colonic stents design, the interaction with colonic tissue is essential in order to characterize the appropriate radial stiffness which provides a minimum lumen for intestinal transit to be maintained. It is therefore important to develop suitable constitutive models allowing the mechanical behavior of the colon tissue to be characterized.
The present work investigates the biomechanical behavior of colonic tissue by means of biaxial tests carried out on different parts of the colonic tract taken from several porcine specimens. Samples from the colonic tract were quasi-statically tensioned using a load-controlled protocol with different tension ratios between the circumferential and the axial directions. Fitting techniques were then used to adjust specific hyperelastic models accounting for the multilayered conformation of the colonic wall and the fiber-reinforced configuration of the
corresponding tissues.
It was found that the porcine colon changed from a more isotropic to a more anisotropic tissue and became progressively more flexible and compliant in circumferential direction depending on the position along the duct as it approaches the rectum. The best predictive capability of mechanical behavior corresponds to the Four Fiber Family model showing mean values of coefficient of determination R2 ¼ 0:97, and a normalized root mean
square error of eNRMS ¼ 0:0814 for proximal spiral samples, and R2 ¼ 0:89 ; eNRMS ¼ 0:1600 and R2 ¼ 0:94 ; eNRMS ¼ 0:1227 for distal spiral and descending colon samples, respectively. The other analyzed models provide good results for proximal spiral colon specimens, which have a lower degree of anisotropy.
The analyzed models with the fitted elastic parameters can be used for more realistic and reliable FE simulations, providing the appropriate framework for the design of optimal devices for the treatment of colonic diseases.

Idioma: Inglés

DOI: 10.1016/j.jmbbm.2019.103507

Año: 2019

Publicado en: Journal of the Mechanical Behavior of Biomedical Materials 102 (2019), 103507 1-15
ISSN: 1751-6161

Factor impacto JCR: 3.372 (2019)

Categ. JCR: MATERIALS SCIENCE, BIOMATERIALS rank: 19 / 38 = 0.5 (2019) - Q2 - T2
Categ. JCR: ENGINEERING, BIOMEDICAL rank: 27 / 87 = 0.31 (2019) - Q2 - T1

Factor impacto SCIMAGO: 0.944 - Mechanics of Materials (Q1) - Biomaterials (Q2) - Biomedical Engineering (Q2)

Tipo y forma: Article (PostPrint)

Área (Departamento): Área Traumatología y Ortopedia (Dpto. Cirugía,Ginecol.Obstetr.)
Área (Departamento): Área Mec.Med.Cont. y Teor.Est. (Dpto. Ingeniería Mecánica)