治疗心血管疾病(即,癌症后死亡的主要原因),基于血管内技术的导丝已用于动脉内导航。迄今为止,大多数市售导丝(例如,Terumo,雅培,科迪斯,等。)是不可操纵的,这是不适合人类动脉系统的许多分叉和角度。为了到达目标动脉,外科医生经常选择几种工具(不同尺寸的导丝集成到成角度的导管中),这些工具可能会引起动脉并发症,例如穿孔或夹层。可转向导丝将,因此,对降低患者的手术发病率和死亡率以及简化外科医生的手术程序非常感兴趣,从而节省时间和健康成本。关于这些原因,我们的研究涉及使用电活性聚合物(EAP)的智能可操纵导丝的开发,当受到输入电压时能够弯曲。通过曲率行为(即,悬臂梁结构的位移和弯曲角度),由印刷在基板上的单堆叠或多堆叠EAP组成。与单堆栈架构相比,多堆叠导致曲率显着增加,即使受到适度的控制电压。正如设计框架所建议的那样,固有的物理性质(电介质,电气,和机械)的EAP层,以及所有材料(EAP和基材)的性质和厚度,对设备的弯曲响应有很大的影响。分析提出了一个全面的指导方针,以优化执行器的性能,基于适当的选择相关的材料和几何参数。研究了分析模型和有限元模型(FEM)以验证实验测试。最后,设计指南导致了一种创新的结构(由10个堆叠的有源层丝网印刷在薄基板上组成),能够在550V的可接受输入电平下产生大范围的弯曲角度(高达190°),这完全符合用于心血管手术的医疗工具的标准。
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.