Mechanical analysis of apical anchors for human heart
ZHANG Ran1, CHEN Si1, JING Teng1, ZHOU Bingjing1, HE Zhaoming2*
1. National Research Center of Pumps, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2. Department of Mechanical Enginee-ring, Texas Tech University, Lubbock, Texas 79409, USA
Abstract:A novel six-teeth nitinol anchor, which is used for heart apical fixation in regurgitation repairing system of mitral and tricuspid valves, was designed, and the mechanical behavior of the anchor was studied numerically. According to cardiac anatomical data, the shape and controllable geometric parameters were defined for the anchor design. 3D models of the different anchor designs were built in SolidWorks, anchor sheathing process was simulated by using FEA calculations for 23 anchor designs in Abaqus. The maximum sheathing force, von Mises strain, and sheathing trajectory influencing factors were analyzed during the sheathing process. A prototype of an anchor design was fabricated and compared with the simulation results. In conclusion, the sheath length and angle as well as the tooth width have the most significant effect on the maximum stress and strain, and a short sheath length or a small angle or a narrow tooth width can lower the maximum stress and strain levels effectively. The thickness, curvature radius and tooth width are decisive in the sheathing force, while the root length and angle have a little effect on the force. The axial penetration depth is mainly determined by controlling the sheath length and angle, but the radial penetration depth is done by the curvature radius. The study could provide some reference for the design of cardiac interventional products of apical fixation.