VISCOELASTIC PROPERTIES OF HUMAN ARTERIES - METHODOLOGY AND PRELIMINARY-RESULTS

In order to study the biomechanical properties of the arterial wall an d to compare arteries with different histologic structures, we designe d a device that allows testing of arterial segments under near-physiol ogic conditions. A hydrodynamic generator simulates systolo-diastolic pressures in an open loop, An int material pressure sensor and a sonom icrometer connected to two piezoelectric crystals placed in diametric opposition on the arterial wall allow computer calculation of complian ce, stiffness, midwall radial arterial stress, Young modulus, and incr emental modulus for a given arterial segment at a given pressure setti ng. Seven healthy common carotid artery (CCA) segments and seven healt hy (superficial) femoral artery (FA) segments were studied immediately after removal from brain-dead donors between the ages of 18 and 35 ye ars. Histologic examination was performed to determine the density of elastic fibers in the arterial wall. Hysteresis was observed in all se gments regardless of pressure settings. Compliance was greater and mod ulus values and stiffness were lower in CCA than in FA. No evidence of structural change was noted after testing in the circulation loop. Th ese preliminary results open the way to a wide variety of applications for our hydrodynamic circulation loop. Experiments will be undertaken to compare the mechanical properties of arteries before and after cry opreservation.