IEEE Trans Biomed Eng. 2021 Jan;68(1):56-67. doi: 10.1109/TBME.2020.2996965. Epub 2020 Dec 21.
Surgical graspers must be safe, not to damage tissue, and effective, to establish a stable contact for operation. For conventional rigid graspers, these requirements are conflicting and tissue damage is often induced. We thus proposed novel soft graspers, based on morphing jaws that increase contact area with clutching force.
We introduced two soft jaw concepts: DJ and CJ. They were designed (using analytical and numerical models) and prototyped (10 mm diameter, 10 mm span). Corresponding graspers were obtained by integrating the jaws into a conventional tool used in the dVRK surgical robotics platform. Morphing performance was experimentally characterized. Jaw-tissue interaction was quantitatively assessed through damage indicators obtained from ex vivo tests and histological analysis, also comparing DJ, CJ and dVRK rigid jaws. Soft graspers were demonstrated through ex vivo tests on dVRK. Ex vivo tests and related analysis were devised/performed with medical doctors.
Design goal was achieved for both soft jaws: by morphing, contact area exceeded by 20-30% the maximum area allowed by encumbrance specifications to rigid jaws. Experimental characterization was in good agreement with model predictions (error ≈ 4%). Damage indicators showed differences amongst DJ, CJ and dVRK jaws (ANOVA p-value = 0.0005): damage was one order of magnitude lower for soft graspers (each pairwise comparison was statistically significant).
We proposed and demonstrated soft graspers potentially less harmful to tissue than conventional graspers.
Beyond minimally invasive surgery, the proposed concepts and design methodology can foster the development of graspers for soft robotics.
手术夹具必须安全，不能损伤组织，并且有效，以建立稳定的操作接触。对于传统的刚性夹具，这些要求是相互冲突的，往往会导致组织损伤。因此，我们提出了基于变形夹爪的新型软夹具，该夹爪可增加夹持力的接触面积。
我们引入了两种软夹爪概念：DJ 和 CJ。它们是使用分析和数值模型设计的（使用分析和数值模型设计的），并使用原型（直径 10mm，跨度 10mm）制造。通过将夹爪集成到用于 dVRK 手术机器人平台的常规工具中，获得了相应的夹具。通过实验特征化了变形性能。通过从离体测试和组织学分析中获得的损伤指标，定量评估了夹爪-组织相互作用，并与 DJ、CJ 和 dVRK 刚性夹爪进行了比较。通过 dVRK 上的离体测试演示了软夹具。离体测试和相关分析是由医生设计/执行的。
两种软夹爪的设计目标都达到了：通过变形，接触面积超过了刚性夹爪允许的最大面积 20-30%。实验特征与模型预测非常吻合（误差≈4%）。损伤指标显示 DJ、CJ 和 dVRK 夹爪之间存在差异（ANOVA p 值=0.0005）：软夹具的损伤低一个数量级（每对比较均具有统计学意义）。
我们提出并证明了软夹具比传统夹具对组织的危害更小。
除了微创手术之外，所提出的概念和设计方法可以促进软机器人夹具的发展。
