title: The relationship between stress and relaxation in calf pericardium used in the construction of cardiac bioprostheses.
abstract: Assessment of relaxation (loss of load within a given time) without apparent deformation is a necessary step before durability assay of biomaterials. From results obtained using calf pericardium, the following conclusions were drawn: (a) there is no limit to relaxation for this biomaterials; (b) the lesser the load applied, the greater the relaxation; and (c) the relaxation curve follows the logarithmic function y = K1 - K2 - Int. These findings demonstrate the poor behaviour of the biomaterial at supposedly low loads and suggest that rupture-point load is not a reliable reference to determine the safety coefficient of calf pericardium used in cardiac bioprostheses.
authors.affiliation: Experimental Surgery Service, Clinica Puerta de Hierro, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: García Páez
authors.forename: A
authors.initials: A
authors.lastname: Carrera San Martín
authors.forename: J V
authors.initials: JV
authors.lastname: García Sestafe
authors.forename: E
authors.initials: E
authors.lastname: Jorge
authors.forename: I
authors.initials: I
authors.lastname: Millán
authors.forename: I
authors.initials: I
authors.lastname: Candela
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001705:Bioprosthesis; D002417:Cattle; D006350:Heart Valve Prosthesis; D066298:In Vitro Techniques; D010496:Pericardium / Q000502:physiology*; D013314:Stress, Mechanical; D013718:Tensile Strength