新型内镜连续缝合器械的结构改进及分析

目的 设计一种新型内镜连续缝合器械，用来克服现有内镜缝合器不能一次性连续释放金属夹的不足，并对内镜缝合器的抓钳提出两种改进方案，通过有限元分析方法，验证其改进后的组织抓持效果。方法 比较分析对齿（原有，抓钳A）、交错齿（抓钳B）、折角交错齿（抓钳C）3种结构抓钳在抓取胃壁组织时，组织受到的压力大小及其分布；然后对组织施加7.5 mm拉伸位移，模拟闭合时器械运动以及组织回弹过程的影响。结果 抓钳A、B闭合组织时，最大应力发生在距离转轴最近的第1对齿上，分别为10.39、10.11 kPa。抓钳C闭合组织时，最大应力发生在第2对齿上，为11.35 kPa。抓钳A、B作用的组织，距离转轴越远，其受到抓钳齿的压力越小。而在抓钳C作用下，器械-组织接触面的压力峰值几乎没有变化。在拉伸位移的作用下，抓钳C没有滑脱；而抓钳A、B拉伸位移分别达到5、6.5 mm时从组织上滑脱。 结论 折角交错齿结构的抓钳闭合时对组织的压力峰值较为稳定，在远离转轴的组织上也能提供充分接触，增大了器械-组织界面的摩擦力，使得抓钳具有更好的抗滑脱能力，提高连续缝合器械的闭合效果。
By developing a novel endoscopic succession closing device to overcome the shortcomings of existing devices that cannot deploy several clips at a time, to perform structural analysis on different clamp structures and to validate their performances in tissue closure through finite element analysis. Methods Comparative analyses of three clamp structures, namely, the aligning tooth structure (original, clamp A), the staggered tooth structure (clamp B), a combination structure with page break angle and staggered tooth (clamp C), were performed to analyze pressure and its distribution on tissues when clamping the stomach wall. Displacement of 7.5 mm was then applied on the clamps to simulate the effect of the operating procedures of the device and tissue kick-back. Results The maximum stresses of the clamp A and B were located on the first pair of teeth which was closest to the rotating shaft, with the stress being 10.39 kPa and 10.11 kPa, respectively. The maximum stress (11.35 kPa) of the clamp C was located on the second pair of teeth. For clamp A and B, the longer the distance to shaft, the larger pressure on stomach tissues. While for clamp C, the pressure on device-tissue interface showed little change along the path. Under tensile displacement, clamp A and B slipped off from the tissue when displacements reached to 5 mm and 6.5 mm, respectively, while clamp C did not. Conclusions　Clamp with page break angle and staggered tooth can exert the uniform max pressure to tissues and provide a larger contact area away from the rotating shaft, thus improving anti-slippage and performance of the novel endoscopic closing device.