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目的设计一种新型内镜连续缝合器械,用以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5.0、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。
Objective To design a new endoscopic continuous suturing device to overcome the shortcomings of the current endocervical sutures that can not release the metal clips in a single operation and to propose two improved solutions for the grasping forceps of endoscopic sutures. , Verify its improved organizational grasping effect. Methods The stress and the distribution of stress on the tissue were graded by three kinds of grasping forceps (teeth grasping, grasping forceps A, teeth grasping forceps B and teeth grasping forceps C) ; 7.5 mm tensile displacement was then applied to the tissue to simulate the effects of device motion and tissue rebound during closure. Results When the grasping forceps A and B were closed, the maximum stress occurred on the first pair of teeth which were closest to the shaft, which were 10.39 and 10.11 kPa, respectively. When the forceps C closed the tissue, the maximum stress occurred on the second pair of teeth, at 11.35 kPa. Grasping forceps A, B role of the organization, the farther away from the shaft, the smaller the pressure of its grasping forceps. In the grasper C under the action, the device - tissue contact surface pressure peak almost no change. Under the action of tensile displacement, the grasping forceps C did not slip off; while the grasping forceps A and B reached the slip of the tissue when the stretching displacement reached 5.0 and 6.5 mm respectively. Conclusions The grasping force with staggered teeth structure closes the pressure peak of tissue more stably and provides sufficient contact on the tissue far away from the shaft, increasing the friction at the instrument-tissue interface and making the forceps better anti-slip Ability to improve the closure of continuous suture instruments.