Haghighipour Nooshin, Tafazzoli-Shadpour Mohammad, Avolio Albert
Cardiovascular Engineering Laboratory, Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran.
J Med Eng Technol. 2010 Oct-Nov;34(7-8):422-8. doi: 10.3109/03091902.2010.514974. Epub 2010 Sep 27.
Excessive wall circumferential stress in arteries caused by luminal pressure leads to endothelial damage and clinical consequences. In addition to circumferential stress, arterial wall contains residual stress with compressive and tensile components on intima and adventitia sides. The intimal compressive component compensates part of tensile stress induced by blood pressure, hence reduces severity of endothelial tension. The opening angle caused by radial cut of arterial ring defines residual stress. In this study, finite element modelling is used to evaluate residual stress in a lamellar model of human aorta with differing opening angle and elastic modulus. Results show non-linear residual stress profiles across wall thickness, influenced by structural and mechanical parameters. Elevation of opening angle from 50° to 90° leads to increase of intimal compressive component compensating up to 32.6% of the pressure-induced tensile stress. Results may be applied in study of endothelial injury caused by excessive stress in situations such as aging, hypertension and atherosclerosis.
管腔内压力导致动脉壁周向应力过大,进而引起内皮损伤并产生临床后果。除周向应力外,动脉壁还含有残余应力,在内膜和外膜侧分别具有压缩和拉伸成分。内膜压缩成分可补偿部分由血压引起的拉伸应力,从而降低内皮张力的严重程度。动脉环径向切割所导致的开口角度定义了残余应力。在本研究中,采用有限元建模方法评估不同开口角度和弹性模量的人体主动脉层状模型中的残余应力。结果显示,残余应力沿壁厚呈非线性分布,受结构和力学参数影响。开口角度从50°升高至90°会导致内膜压缩成分增加,可补偿高达32.6%的压力诱导拉伸应力。研究结果可应用于衰老、高血压和动脉粥样硬化等情况下过度应力引起的内皮损伤研究。