A piece-wise non-linear elastic stress expression of human and pig coronary arteries tested in vitro

• Published in: Journal of biomechanics Vol. 24; no. 10; pp. 899 - 906
• Main Authors: Carmines, David V., McElhaney, James H., Stack, Richard
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1991; Elsevier Science
• Subjects: Animals; Biological and medical sciences; Coronary Vessels - anatomy & histology; Coronary Vessels - physiology; Elasticity; Fundamental and applied biological sciences. Psychology; Humans; Medical sciences; Models, Cardiovascular; Pressure; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Stress, Mechanical; Swine; Vertebrates: cardiovascular system; Viscosity; Biomechanics; Vertebrata; Vasomotricity; Mammalia; Blood volume; Coronary artery; Circulatory system; Hemodynamics; Mathematical model; Methodology; Constraint; Artery; Materials
• ISSN: 0021-9290; 1873-2380
• DOI: 10.1016/0021-9290(91)90168-M

Eight human and nineteen pig unembalmed proximal left anterior descending and circumflex coronary arteries were subjected to linear volume changes (2 s ramp time) at three fixed axial extensions while immersed in a physiological saline bath at body temperature. Measured parameters included: lumen pressure, outside diameter, axial force, and axial extension. The deformations were measured using a video dimensional analyzer. The arteries were inflated to pressures well above the physiological range at each axial extension. A latex inner tube was placed inside of each specimen to prevent leakage, and its effects upon the measured stresses were corrected analytically. With this method, the average circumferential and axial stresses could be computed directly from the experimental data. In both directions the average stresses measured displayed two distinct regions: stresses occurring for small diameter changes (physiological pressures) and stresses occurring for large diameter changes (high pressures). The resulting average small strain and large strain stress components were curve-fit separately and, when reassembled, provided a piecewise model of the stress response of coronary arteries over a wide range of inflation pressures and axial extensions.