Toinet Simon, Benwadih Mohammed, Szambolics Helga, Revenant Christine, Alincant David, Bordet Marine, Capsal Jean-Fabien, Della-Schiava Nellie, Le Minh-Quyen, Cottinet Pierre-Jean
University Grenoble Alpes, CEA, LITEN DTNM, 38000 Grenoble, France.
Department of Vascular and Endovascular Surgery, Hospices Civils de Lyon, 69500 Bron, France.
Materials (Basel). 2024 May 2;17(9):2135. doi: 10.3390/ma17092135.
To treat cardiovascular diseases (i.e., a major cause of mortality after cancers), endovascular-technique-based guidewire has been employed for intra-arterial navigation. To date, most commercially available guidewires (e.g., Terumo, Abbott, Cordis, etc.) are non-steerable, which is poorly suited to the human arterial system with numerous bifurcations and angulations. To reach a target artery, surgeons frequently opt for several tools (guidewires with different size integrated into angulated catheters) that might provoke arterial complications such as perforation or dissection. Steerable guidewires would, therefore, be of high interest to reduce surgical morbidity and mortality for patients as well as to simplify procedure for surgeons, thereby saving time and health costs. Regarding these reasons, our research involves the development of a smart steerable guidewire using electroactive polymer (EAP) capable of bending when subjected to an input voltage. The actuation performance of the developed device is assessed through the curvature behavior (i.e., the displacement and the angle of the bending) of a cantilever beam structure, consisting of single- or multi-stack EAP printed on a substrate. Compared to the single-stack architecture, the multi-stack gives rise to a significant increase in curvature, even when subjected to a moderate control voltage. As suggested by the design framework, the intrinsic physical properties (dielectric, electrical, and mechanical) of the EAP layer, together with the nature and thickness of all materials (EAP and substrate), do have strong effect on the bending response of the device. The analyses propose a comprehensive guideline to optimize the actuator performance based on an adequate selection of the relevant materials and geometric parameters. An analytical model together with a finite element model (FEM) are investigated to validate the experimental tests. Finally, the design guideline leads to an innovative structure (composed of a 10-stack active layer screen-printed on a thin substrate) capable of generating a large range of bending angle (up to 190°) under an acceptable input level of 550 V, which perfectly matches the standard of medical tools used for cardiovascular surgery.
为了治疗心血管疾病（即癌症之后的主要死因），基于血管内技术的导丝已被用于动脉内导航。迄今为止，大多数市售导丝（例如泰尔茂、雅培、科迪斯等）是不可转向的，这对于具有众多分支和角度的人体动脉系统来说不太适用。为了到达目标动脉，外科医生经常选择几种工具（集成在成角度导管中的不同尺寸的导丝），这可能会引发诸如穿孔或夹层等动脉并发症。因此，可转向导丝对于降低患者的手术发病率和死亡率以及简化外科医生的操作流程具有很高的价值，从而节省时间和医疗成本。基于这些原因，我们的研究涉及开发一种使用电活性聚合物（EAP）的智能可转向导丝，该导丝在受到输入电压时能够弯曲。通过由印刷在基板上的单层或多层EAP组成的悬臂梁结构的曲率行为（即弯曲的位移和角度）来评估所开发装置的驱动性能。与单层结构相比，即使在受到适度的控制电压时，多层结构也会使曲率显著增加。如设计框架所表明的，EAP层的固有物理特性（介电、电气和机械）以及所有材料（EAP和基板）的性质和厚度确实对装置的弯曲响应有很大影响。这些分析提出了一个全面的指导方针，以便基于对相关材料和几何参数的适当选择来优化致动器性能。研究了一个分析模型以及一个有限元模型（FEM）以验证实验测试。最后，该设计指导方针产生了一种创新结构（由印刷在薄基板上的10层有源层组成），该结构能够在550V的可接受输入水平下产生大范围的弯曲角度（高达190°），这与用于心血管手术的医疗工具标准完美匹配。
