Objective Uniaxial Identification of Transition Points in Non-Linear Materials: Sample Application to Porcine Coronary Arteries and the Dependency of Their Pre- and Post-Transitional Moduli with Position

Freij, Jenny M.; Burton, Hanna E.; Espino, Daniel M.

doi:10.1007/s13239-018-00395-x

Cited by 8 publications

(11 citation statements)

References 38 publications

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“…However, it is feasible to add a patient specific waveform for more specific understanding to a given individual [19,20,46]. Third, physiologically, blood pressure is pulsatile with dependency on both the pumping of the heart and also vascular compliance; which can be characterised using elastic (linear or non-linear) and viscoelastic properties [47,48]. However, this compliance was not accounted for in our models.…”

Section: Discussionmentioning

confidence: 99%

Computational analysis to predict the effect of pre-bifurcation stenosis on the hemodynamics of the internal and external carotid arteries

Bouteloup¹,

Marinho²,

Chatpun³

et al. 2020

JMES

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This study assessed the hemodynamics of a patient-specific multiple stenosed common carotid artery including its bifurcation into internal and external carotid arteries; ICA and ECA, respectively. A three-dimensional computational model of the common carotid artery was reconstructed using a process of segmentation. Computational fluid dynamics was applied with the assumption that blood is Newtonian and incompressible under pulsatile conditions through the stenotic artery and subsequent bifurcation. Blood was modelled as ‘normal’ and ‘hyperglycaemic’. A region of large recirculation was found to form at bifurcation. The asymmetric velocity flow profile through the ICA was evident through the cardiac cycle with higher velocity at the inner walls of ICA. Hyperglycaemia was found to increase wall shear stresses on the carotid artery and reduce the blood velocity by as much as 4 times in ECA. In conclusion, hemodynamics in ICA and ECA are not equally affected by stenosis, with hyperglycaemic blood potentially providing additional complications to the clinical case.

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Section: Discussionmentioning

confidence: 99%

Computational analysis to predict the effect of pre-bifurcation stenosis on the hemodynamics of the internal and external carotid arteries

Bouteloup¹,

Marinho²,

Chatpun³

et al. 2020

JMES

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“…For convenience, the mean slack length of the tendon will equal the mean initial tendon length L 0 . Equations (1)-(3) have been adapted from Freij et al [54], Equation (4) from Vigouroux et al [22] and Equations (5)-(7) from Young et al [53] to calculate the actual cross-sectional area a, true stress σ and stiffness after each position. Where λ is the stretch ratio, L is the actual length and F is force given in ABAQUS.…”

Section: Discussionmentioning

confidence: 99%

A Finite Element Model for Trigger Finger

2020

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The aim of this study was to develop a finite element model to investigate the forces on tendons which ensue due to trigger finger. The model was used to simulate both flexor and extensor tendons within the index finger; two test cases were defined, simulating a “mildly” and “severely” affected tendon by applying constraints. The finger was simulated in three different directions: extension, abduction and hyper-extension. There was increased tension during hyper-extension, with tension in the mildly affected tendon increasing from 1.54 to 2.67 N. Furthermore, there was a consistent relationship between force and displacement, with a substantial change in the gradient of the force when the constraints of the condition were applied for all movements. The intention of this study is that the simulation framework is used to enable the in silico development of novel prosthetic devices to aid with treatment of trigger finger, given that, currently, the non-surgical first line of treatment is a splint.

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“…For example, in the above study by Van Andel et al [9], the age of the human subjects from which the arteries were obtained ranged from 61 to 85 years old, a limitation in itself given the effects of ageing on collagen in soft connective tissues [41]. Further, a recent study has demonstrated the feasibility to objectively identify a transition point during mechanical loading of the coronary arteries [6]; the novel results presented in this current study open up the possibility to assess whether the surface roughness of the coronary arteries varies before/after such a transition.…”

Section: Discussionmentioning

confidence: 99%

“…The mechanical behaviour of the coronary arteries can be characterised through uniaxial testing [6] which is a commonly chosen methodology for these arteries [4, 7–9]. Porcine models are typically employed because of their anatomic similarity to the human hearts [8].…”

Section: Introductionmentioning

confidence: 99%

The Effect of Mechanical Overloading on Surface Roughness of the Coronary Arteries

Burton

Espino

2019

Applied Bionics and Biomechanics

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Background. Surface roughness can be used to identify disease within biological tissues. Quantifying surface roughness in the coronary arteries aids in developing treatments for coronary heart disease. This study investigates the effect of extreme physiological loading on surface roughness, for example, due to a rupture of an artery. Methods. The porcine left anterior descending (LAD) coronary arteries were dissected ex vivo. Mechanical overloading was applied to the arteries in the longitudinal direction to simulate extreme physiological loading. Surface roughness was calculated from three-dimensional reconstructed images. Surface roughness was measured before and after damage and after chemical processing to dehydrate tissue specimens. Results. Control specimens confirmed that dehydration alone results in an increase of surface roughness in the circumferential direction only. No variation was noted between the hydrated healthy and damaged specimens, in both the longitudinal (0.91±0.26 and 1.05±0.25 μm) and circumferential (1.46±0.38 and 1.47±0.39 μm) directions. After dehydration, an increase in surface roughness was noted for damaged specimens in both the longitudinal (1.28±0.33 μm) and circumferential (1.95±0.56 μm) directions. Conclusions. Mechanical overloading applied in the longitudinal direction did not significantly affect surface roughness. However, when combined with chemical processing, a significant increase in surface roughness was noted in both the circumferential and longitudinal directions. Mechanical overloading causes damage to the internal constituents of the arteries, which is significantly noticeable after dehydration of tissue.

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Objective Uniaxial Identification of Transition Points in Non-Linear Materials: Sample Application to Porcine Coronary Arteries and the Dependency of Their Pre- and Post-Transitional Moduli with Position

Cited by 8 publications

References 38 publications

Computational analysis to predict the effect of pre-bifurcation stenosis on the hemodynamics of the internal and external carotid arteries

Computational analysis to predict the effect of pre-bifurcation stenosis on the hemodynamics of the internal and external carotid arteries

A Finite Element Model for Trigger Finger

The Effect of Mechanical Overloading on Surface Roughness of the Coronary Arteries

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