title: Morphological approach for the functional improvement of an artificial myocardial assist device using shape memory alloy fibres.
abstract: The authors have been developing a mechano-electric artificial myocardial assist system (artificial myocardium) which is capable of supporting natural contractile functions from the outside of the ventricle without blood contacting surface. In this study, a nano-tech covalent type shape memory alloy fibre (Biometal, Toki Corp, Japan) was employed and the parallel-link structured myocardial assist device was developed. And basic characteristics of the system were examined in a mechanical circulatory system as well as in animal experiments using goats. The contractile functions were evaluated with the mock circulatory system that simulated systemic circulation with a silicone left ventricular model and an aortic afterload. Hemodynamic performance was also examined in goats. Prior to the measurement, the artificial myocardial assist device was installed into the goat's thoracic cavity and attached onto the ventricular wall. As a result, the system could be installed successfully without severe complications related to the heating, and the aortic flow rate was increased by 15% and the systolic left ventricular pressure was elevated by 7% under the cardiac output condition of 3L/min in a goat. And those values were elevated by the improvement of the design which was capable of the natural morphological myocardial tissue streamlines. Therefore it was indicated that the effective assistance might be achieved by the contraction by the newly-designed artificial myocardial assist system using Biometal. Moreover it was suggested that the assistance gain might be obtained by the optimised configuration design along with the natural anatomical myocardial stream line.
authors.affiliation: Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan. shiraishi@idac.tohoku.ac.jp
authors.forename: Y
authors.initials: Y
authors.lastname: Shiraishi
authors.forename: T
authors.initials: T
authors.lastname: Yambe
authors.forename: Y
authors.initials: Y
authors.lastname: Saijo
authors.forename: F
authors.initials: F
authors.lastname: Sato
authors.forename: A
authors.initials: A
authors.lastname: Tanaka
authors.forename: M
authors.initials: M
authors.lastname: Yoshizawa
authors.forename: D
authors.initials: D
authors.lastname: Ogawa
authors.forename: Y
authors.initials: Y
authors.lastname: Wada
authors.forename: S
authors.initials: S
authors.lastname: Itoh
authors.forename: R
authors.initials: R
authors.lastname: Sakata
authors.forename: Y
authors.initials: Y
authors.lastname: Park
authors.forename: M
authors.initials: M
authors.lastname: Uematsu
authors.forename: M
authors.initials: M
authors.lastname: Umezu
authors.forename: T
authors.initials: T
authors.lastname: Fujimoto
authors.forename: N
authors.initials: N
authors.lastname: Masumoto
authors.forename: H
authors.initials: H
authors.lastname: Liu
authors.forename: A
authors.initials: A
authors.lastname: Baba
authors.forename: S
authors.initials: S
authors.lastname: Konno
authors.forename: S
authors.initials: S
authors.lastname: Nitta
authors.forename: K
authors.initials: K
authors.lastname: Imachi
authors.forename: K
authors.initials: K
authors.lastname: Tabayashi
authors.forename: H
authors.initials: H
authors.lastname: Sasada
authors.forename: D
authors.initials: D
authors.lastname: Homma
mesh_terms: D000497:Alloys; D000818:Animals; D001783:Blood Flow Velocity; D006041:Goats; D006353:Heart-Assist Devices; D006439:Hemodynamics; D006801:Humans; D008955:Models, Cardiovascular; D009200:Myocardial Contraction; D009206:Myocardium
chemical_list: D000497:Alloys