目的 设计一种适用于肛瘘内口闭合手术的封堵器,研究封堵器的结构设计以及植入物与组织的相互作用,评估内口封堵性能。 方法 对封堵器进行整体结构设计与样机制作;建立封堵有限元模型,研究封堵过程中组织的应力分布及损伤面积;搭建组织穿刺实验平台对仿真模型及结果进行验证;搭建拔出力实验平台对内口封堵效果进行评估。 结果 封堵过程中,进给机构的最大扭矩为 36 mN·m,组织的最大应力为 19. 75 MPa,其损伤面积为1. 35 cm2。 有限元理论模型与实验结果基本吻合,最大拔出力达到 5. 11 N。 结论 封堵过程中的组织损伤面积满足肛瘘的微创治疗要求。 本文设计的微创肛瘘封堵器可实现内口的有效封堵,有助于医生更加便捷、快速、有效地完成肛瘘的微创手术。

Objective To design a occluder suitable for the anal fistula internal mouth occlusion surgery, study structural design of the occluder, as well as the interaction between implants and tissues, and evaluate performance of the internal mouth occlusion. Methods The overall structure of the occluder was designed and the prototype was manufactured. The finite element model of occluding was established to study the stress distribution and damage area of tissues during occlusion; the tissues puncture experimental platform was built to verify the simulation model and results; the pull-out force test platform was built to evaluate the occlusion effect of the internal mouth. Results During the occlusion process, the maximum torque of the feeding mechanism was 36 mN · m, the maximum stress of the tissues was 19.75 MPa, and the damage area was 1.35 cm2. The finite element model was basically consistent with the experimental results, and the maximum pull-out force reached 5.11N. Conclusions The area of tissues damage in the process of occlusion meets the requirements of minimally invasive treatment of anal fistula. The minimally invasive anal fistula occluder designed in this study can effectively occlude the internal mouth, which is helpful for doctors to perform minimally invasive surgery for anal fistula more conveniently, quickly and effectively.

国家自然科学基金项目(51735003)