School of Mechanical Engineering and Automation, Beijing University of Aeronautics and Astronautics, Beijing, People's Republic of China.
Int J Med Robot. 2012 Mar;8(1):25-33. doi: 10.1002/rcs.419. Epub 2011 Oct 10.
Due to differences in corneal grafting microsurgery between manual and robotic suturing, new challenges have arisen in testing the insertion force and torque of corneal tissue acting on suturing needles in order to guarantee successful completion of surgical procedures.
In order to measure the force during the insertion operation, from the needle entering the cornea through the entry point until the puncturing of the exit point along the circular trajectory, a force measurement system was established, including fresh porcine cornea, a corneal-suturing robot, a circular needle, a micro-forceps manipulator with a force transducer, a computer with a data acquisition board and a medical microscope. The force values in the needle coordinate frames were obtained on the basis of a sensor coordinate frame through D-H coordinate transformation, and an index is proposed here to evaluate the insertion performance. Experiments on both manual and robotic suturing were carried out for comparison.
The scale and changes of the needle insertion force were obtained using two different suturing methods. The maximal tangent force in robotic suturing is a little larger than in manual suturing, and the maximal resultant force in robotic suturing is somewhat smaller. Although the difference is not very significant, robotic suturing performs in a more stable way. Moreover, the performance evaluation index M(dmax) (the maximum of square root of the quadratic sum of torque components M(OX) and M(OY)) in robotic suturing is much smaller than that in manual suturing.
The force measurement system has been verified to be feasible through experimentation. Compared with conventional manual surgery, robotic suturing has some advantages: more stable suturing, smaller distortion torque and fewer invasions to the corneal tissue, showing that its application in minimally invasive surgery is practical.
由于手动和机器人缝合角膜移植显微手术之间的差异，在测试作用于缝线针的角膜组织插入力和扭矩时出现了新的挑战，以保证手术过程的成功完成。
为了测量插入操作过程中的力，从针从进入点进入角膜，直到沿着圆形轨迹刺穿出口点，建立了一个力测量系统，包括新鲜的猪角膜、角膜缝合机器人、圆形针、带有力传感器的微夹持器、带有数据采集板的计算机和显微镜。通过 D-H 坐标变换，在传感器坐标框架的基础上获得针坐标框架中的力值，并提出了一个评估插入性能的指标。进行了手动和机器人缝合的实验比较。
使用两种不同的缝合方法获得了针插入力的规模和变化。机器人缝合的最大切向力稍大于手动缝合，机器人缝合的最大合力稍小。虽然差异不是非常显著，但机器人缝合的表现更稳定。此外，机器人缝合的性能评估指标 M(dmax)（扭矩分量 M(OX)和 M(OY)的二次和的平方根的最大值）远小于手动缝合的 M(dmax)。
通过实验验证了力测量系统的可行性。与传统的手动手术相比，机器人缝合具有一些优势：更稳定的缝合、更小的扭曲扭矩和对角膜组织的侵入性更小，表明其在微创手术中的应用是实用的。
