title: Experimental and constitutive modeling approaches for a study of biomechanical properties of human coronary arteries.
abstract: The study concerns the determination of mechanical properties of human coronary arterial walls with both experimental and constitutive modeling approaches. The research material was harvested from 18 patients (range 50-84 years). On the basis of hospital records and visual observation, each tissue sample was classified according to the stage (0, I, II, III) of atherosclerosis development (SAD). Then, strip samples considered as a membrane with the shape of rectangular parallelepiped were preconditioned and subjected to uniaxial tensile tests in longitudinal (n=27) and circumferential (n=4) direction. With experimental data obtained, the stress-strain characteristics were prepared. Furthermore, tensile strengths and related strains, stiffness coefficients and tangent modules of elasticity were computed. For a constitutive model of passive mechanical behavior of coronary arteries, values of material parameters were computed. The studies led to the following conclusions. Most importantly, the atherosclerotic changes affect all the mechanical properties of arterial walls. A progress of arteriosclerosis contributes to an increase of vascular stiffness. The highest values of the stiffness coefficients are obtained for the tissues in the advanced stage of the disease. We were also able to observe that gradual calcification, progression of atherosclerosis and degradation of collagen in the tissue caused a decrease of tensile strengths and related strains. Finally, a comparison made for the tissues with the advanced SAD showed that the tensile strengths and strains were much higher in the case of the samples with the circumferential orientation rather than those with the longitudinal one.
authors.affiliation: Poznan University of Technology, Institute of Applied Mechanics, Jana Pawla II 24, 60-965 Poznan, Poland. Electronic address: malgorzata.jankowska@put.poznan.pl.
authors.forename: Malgorzata A
authors.initials: MA
authors.lastname: Jankowska
authors.affiliation: Wroclaw University of Technology, Institute of Machine Design and Operation, Lukasiewicza 7/9, 50-371 Wroclaw, Poland; Wrovasc - Integrated Cardiovascular Centre, Regional Specialist Hospital, Research and Development Centre, Kamienskiego 83a, 51-124 Wroclaw, Poland. Electronic address: magdalena.jowsa@gmail.com.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Bartkowiak-Jowsa
authors.affiliation: University of Zielona Gora, Institute of Mechanical Engineering and Machine Operation, Division of Biomedical Engineering, Podgorna 50, 65-246 Zielona Gora, Poland. Electronic address: romuald.bedzinski@pwr.edu.pl.
authors.forename: Romuald
authors.initials: R
authors.lastname: Bedzinski
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001696:Biomechanical Phenomena; D003324:Coronary Artery Disease / Q000473:pathology; D003331:Coronary Vessels / Q000166:cytology / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D055595:Mechanical Phenomena; D008875:Middle Aged; D008954:Models, Biological; D013314:Stress, Mechanical
keywords: Atherosclerosis; Biomechanical properties of arterial walls; Constitutive models; Human coronary arteries