Determining the biomechanical properties of human intracranial blood vessels through biaxial tensile test and fitting them to a hyperelastic model

Abstract

Understanding mechanical properties of healthy and unhealthy cerebral vessels is a key element in the development of their science and the relevant clinical diagnosis, prevention and treatment. Thirteen healthy samples were obtained from 23 middle cerebral arteries. The changes of force and deformation until the vessel rupture were recorded using a biaxial device. Thereafter, the stress-strain curve was plotted and fitted with a hyperelastic five-parameter Mooney-Rivlin model and the model parameters (C1, C2, C3, C4, and C5) were determined according to the best fit. For statistical comparison, the samples were divided into three age and two gender groups and subjected to non-parametric statistical analyses. Comparison of obtained results for different age groups showed that there is a significant difference between the "old" group and the other two groups (middle-aged and young). There was no significant difference between male and female groups. Therefore, the results demonstrate the changes of blood vessel wall properties with aging. The results also depicted that the arterial wall is stiffer in the circumferential direction than the axial direction. Anisotropy of cerebral vessels was confirmed by all of the tests. Therefore, the significance of the biaxial tests is in the spot light in the derived data. Moreover, good fitting of data illuminated that the use of multiple-parameter constitutive models is useful for mathematical demonstration of cerebral vessel tissue behavior. In conclusion, good fitting of data illuminated that the use of multiple-parameter constitutive models is useful for mathematical demonstration of cerebral vessel tissue behavior.}}

Age-related vascular stiffening: causes and consequences

“…Tensile testing has been performed on human arteries to characterize their mechanical changes in a number of conditions, including aging ( Vande Geest et al, 2005 ; Haskett et al, 2010 ; Shafigh et al, 2013 ), as well as plaque ( Walsh et al, 2014 ) and aneurism development ( Khanafer et al, 2011 ). Most often, aortas, coronary arteries, and carotid arteries are used to study the differential mechanics of diseased states after autopsy because they are the dominant sites of disease development, and as the largest vessels, they are also the easiest to obtain ( Glagov et al, 1988 ; Atienza, 2010 ; Karimi et al, 2013 ; Walsh et al, 2014 ).…”

“…Recent experiments have used biaxial testing devices to study blood vessels ( Vande Geest et al, 2005 ; Zemánek et al, 2009 ; Haskett et al, 2010 ), which are more representative of in vivo mechanical loading. As examples, biaxial testing has been used to microscopically observe the failure point of artery rupture ( Sugital and Matsumoto, 2013 ) and to show that the arterial wall is stiffer in the circumferential direction compared to the axial direction ( Shafigh et al, 2013 ).…”

Review of the Techniques Used for Investigating the Role Elastin and Collagen Play in Arterial Wall Mechanics

“…Arterial anisotropicity has been shown in a number of experimental works; in the physiological range of pressure, arteries show a higher stiffness in the circumferential direction than in the longitudinal one due to preferential fibres orientation ( Figure 2) [64], [68], [69]. Also, the stress-strain curves show a higher dispersion in the longitudinal direction, indicating more variable mechanical properties.…”

Mechanical Characterization and Torsional Buckling Effects of Pediatric Vascular Patches

“…Fung's 2D stress-strain curves were fitted to the stress-strain data derived from the forcedisplacement data obtained through biaxial tensile testing for porcine pericardium. The resulting nonlinear material parameters for porcine pericardium are presented in Table 4, along with literature values for the material parameters of the human intracranial blood vessel (Shafigh et al 2013) for comparison. Figure 4 depicts the measured data and the corresponding curves fitted to the data in both axial and circumferential directions.…”