Development of a Humanoid Hand System to Support Robotic Urological Surgery.

In robotic urological surgery, it is common for an assistant to use laparoscopic forceps to move organs clear of the surgical working space; however, the assistance efficiency is low. In this study, we aimed to develop a three-fingered humanoid hand with multiple degrees of freedom and a folding mechanism that would allow it to be inserted through a small incision to improve the efficiency of assisting with organs. The bladder (with prostate) and kidneys were selected as the target organs. To achieve stable assistance for these organs, we analyzed three postures: "grasp," "open palm," and "pinch." We verified that the proposed hand can be inserted into the abdominal cavity through a 20 mm port and can assist in a grasping an object of the same size as the target organ with these three movements. Clinical Relevance- The proposed three-fingered, eight-degree-of-freedom humanoid hand with a folding mechanism can be inserted through a 20-mm port and is shown to be able to stably assist in grasping objects of the same size as the kidney and bladder (with prostate) in the urological surgical workspace.