Mechanical behavior measurement of the sheep small intestine using experimental tests

Document Type: Pathology

Authors

Biological Fluid Dynamics Laboratory, Biomechanics Department, Biomedical Engineering Faculty, Amirkabir University of Technology, Tehran, Iran

Abstract

Background: There is no consistent data on the mechanical properties of sheep intestine. OBJECTIVES: We performed a series of biaxial strain measurement experiments and extracted the constitutive model to describe the mechanical characteristics of the sheep intestinal tissue. METHODS: Eleven specimens were obtained freshly from sacrificed  sheep and the planar biaxial tests were performed on the tissue specimens by applying simultaneous loads along the circumfer-ential and longitudinal directions. Then the measured data were fitted into the anisotropic four-parameter Fung-type model and also to the modified Mooney-Rivlin model. RESULTS: The specimens showed some degree of anisotropy; the stiffer direction is not gener-ally predictable. Some of the specimens were stiffer in the circumferential direction, and the others in the longitudinal direction. However, the average results state the circumferential di-rection as the stiffer orientation. CONCLUSIONS: It can be concluded that sheep intestine be-haves normally as a nonlinear anisotropic tissue which is well-characterized by the modified Mooney-Rivlin model.

Keywords


Article Title [Persian]

اندازه گیری رفتار مکانیکی روده کوچک گوسفند با استفاده از آزمون های تجربی

Authors [Persian]

  • آیسا رسولی
  • ناصر فتورائی
گروه بیومکانیک، دانشکده مهندسی پزشکی، دانشگاه صنعتی امیرکبیر، تهران، ایران
Abstract [Persian]

زمینه مطالعه:  اطلاعات جامعی در مورد خواص مکانیکی روده گوسفند وجود ندارد. هدف: برای این منظور تعدادی آزمون‌های کشش دومحوری انجام شد و مدل بنیادی برای توصیف خواص مکانیکی بافت روده گوسفند استخراج شد. روش کار: یازده نمونه تازه گوسفندی تهیه شد و آزمون‌های مسطح دومحوری بر نمونه‌ها با اعمال همزمان نیرو در دو جهت طولی و پیرامونی انجام شد. سپس داده‌های اندازه‌گیری شده با مدل ناهمسانگرد چهار پارامتر فانگ و مدل مونی-ریولین بهینه شده برازش شدند. نتایج: داده‌ها درجه‌ای از ناهمسانگردی را نشان دادند. جهت سختی بافت قابل پیش بینی نبود. تعدادی از نمونه‌ها در جهت پیرامونی سخت تر بودند و بعضی‌ها در جهت طولی. میانگین نتایج نشان داد که جهت پیرامونی سخت تر می باشد. نتیجه گیری نهایی: می‌توان نتیجه گرفت که روده گوسفند به عنوان بافت ناهمسانگرد غیر خطی رفتار می‌کند که با مدل مونی-ریولین بهتر برازش می شود.

Keywords [Persian]

  • مدل بنیادی ناهمسانگرد
  • مدل فانگ
  • بافت غیر خطی
  • مدل مونی-ریولین بهینه شده
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