97328 20210104132018.0 doi 10.1016/j.jmbbm.2019.103507 sideral 115461 ART-2019-115461 eng (orcid)0000-0002-3613-4209 Puértolas, S. Universidad de Zaragoza A comparative study of hyperelastic constitutive models for colonic tissue fitted to multiaxial experimental testing 2019 Access copy available to the general public Unrestricted 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. info:eu-repo/semantics/openAccess by-nc-nd http://creativecommons.org/licenses/by-nc-nd/3.0/es/ 3.372 2019 MATERIALS SCIENCE, BIOMATERIALS 19 / 38 = 0.5 2019 Q2 T2 ENGINEERING, BIOMEDICAL 27 / 87 = 0.31 2019 Q2 T1 0.944 2019 Mechanics of Materials 2019 Q1 Biomaterials 2019 Q2 Biomedical Engineering 2019 Q2 info:eu-repo/semantics/article info:eu-repo/semantics/acceptedVersion (orcid)0000-0002-0664-5024 Peña, E. Universidad de Zaragoza (orcid)0000-0002-8643-7558 Herrera, A. Universidad de Zaragoza (orcid)0000-0003-0785-4132 Ibarz, E. Universidad de Zaragoza (orcid)0000-0001-7944-9625 Gracia, L. Universidad de Zaragoza 1004 830 Universidad de Zaragoza Dpto. Cirugía,Ginecol.Obstetr. Área Traumatología y Ortopedia 5004 605 Universidad de Zaragoza Dpto. Ingeniería Mecánica Área Mec.Med.Cont. y Teor.Est. 102 (2019), 103507 1-15 J. mech. behav. boomed. mater. Journal of the Mechanical Behavior of Biomedical Materials 1751-6161 8255410 http://zaguan.unizar.es/record/97328/files/texto_completo.pdf Postprint 238569 http://zaguan.unizar.es/record/97328/files/texto_completo.jpg?subformat=icon icon Postprint oai:zaguan.unizar.es:97328 articulos driver 2021-01-04-10:58:46 ARTICLE