Curved Bistable Origami-Inspired Flexible Transcatheter Mitral Valve Clamping

Curved origami exhibits remarkable potential for minimally invasive medical applications owing to its unique geometric programmability and mechanical tunability. Building on this concept, a curved origami with bistable mechanical behavior is proposed, specifically engineered for transcatheter mitral valve clamping surgery. Benefiting from its bistable characteristics, the curved origami structure enables three key functions: it remains compactly folded during catheter delivery, self-deploys rapidly and precisely at the target site, and maintains a stable, fully expanded configuration during device retrieval. The equivalent stiffness of the curved origami mechanism is tuned through geometric nonlinearity, ensuring that its critical transition load closely simulates the catheter-based delivery conditions. Theoretical analysis and experimental validation confirm that bistability is effectively preserved, while parameters such as initial curvature, thickness, crease curvature, and segment length can be adjusted to precisely tailor the radial support stiffness, meeting the mechanical requirements for resisting mitral valve contraction forces. In vitro experiments further verify the dilator's exceptional stability and fully reliable deployment within a simulated mitral valve environment. This work advances the engineering application of curved origami mechanics in minimally invasive medical treatments, offering both theoretical insights and promising potential for clinical translation.