Kim Hansoul, You Jae Min, Hwang Minho, Kyung Ki-Uk, Kwon Dong-Soo
Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
Robotics Program, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.
Soft Robot. 2023 Apr;10(2):234-245. doi: 10.1089/soro.2021.0148. Epub 2022 Jun 28.
The overtube of an endoscopic surgery robot is fixed when performing tasks, unlike those of commercial endoscopes, and this overtube should have high structural stiffness after reaching the target lesion so that sufficient tension can be applied to the lesion tissue with the surgical tool and there are fewer changes in the field of view of the endoscopic camera from this reaction force. Various methods have been proposed to reinforce the structural stiffnesses of hyper-redundant manipulators. However, the safety, rapid response, space efficiency, and cost-effectiveness of these methods should be considered for use in actual clinical environments, such as the gastrointestinal tract. This study proposed a method to minimize the positional changes of the overtube end tip due to external forces using only auxiliary tendons in the optimized path without additional mechanical structures. Overall, the proposed method involved moving the overtube to the target lesion through the main driving tendon and applying tension to the auxiliary tendons to reinforce the structural stiffness. The complete system was analyzed in terms of energy, and the sigmoidal auxiliary tendons were verified to effectively reinforce the structural stiffness of the overtube consisting of rolling joints. In addition, the design guidelines of the overtube for actual endoscopic surgery were proposed considering hollowness, retroflexion, and high structural stiffness. The positional changes due to external forces were confirmed to be reduced by 60% over the entire workspace.
与商用内窥镜不同，内窥镜手术机器人的外套管在执行任务时是固定的，并且该外套管在到达目标病变部位后应具有较高的结构刚度，以便能够用手术工具对病变组织施加足够的张力，并且内窥镜摄像头视场因该反作用力产生的变化较小。已经提出了各种方法来增强超冗余操纵器的结构刚度。然而，在诸如胃肠道等实际临床环境中使用这些方法时，应考虑其安全性、快速响应性、空间效率和成本效益。本研究提出了一种仅在优化路径中使用辅助肌腱而无需额外机械结构的方法，以最小化外套管末端因外力引起的位置变化。总体而言，所提出的方法包括通过主驱动肌腱将外套管移动到目标病变部位，并对辅助肌腱施加张力以增强结构刚度。对整个系统进行了能量分析，验证了S形辅助肌腱能有效增强由旋转关节组成的外套管的结构刚度。此外，考虑到中空性、向后弯曲和高结构刚度，提出了实际内窥镜手术中外套管的设计准则。在整个工作空间中，因外力引起的位置变化被证实减少了60%。
