EXPERIMENTAL STUDIES ON TENSILE PROPERTIES OF CANINE HEART MUSCLE AT SELECTED SITES

The testing setup and method to accomplish tensile tests of canine heart muscle tissues are developed. The tests including three types: uniaxial tension, relaxation and fracture, applied at 10 selected sites of 6 canine hearts. The stress-strain curves, stress relaxation curves and damage limits of the heart muscle were obtained. It is found that the epcardium of left ventricular lateral wall has the highest stiffness and strength, while right atrium lateral wall, right atrium appendix, atrium interseptum have the lowest stiffness and strength, with other sites fitted in between. The tension test data were used to fit the Pole-zero model and the correlation between them is satisfied. A viscoelastic item was added to modify the Pole-zero model due to the relaxation test data.