Design of miniature modular in vivo robots for dedicated tasks in Minimally Invasive Surgery

Minimally Invasive Surgery (MIS) is widespread in medical procedures aiming to provide incision-less surgery. Conventional MIS provides limited tissue manipulation, because of the constrained directionality of force application and low number of Degrees of Freedom (DoFs). Robotic systems have been proposed to overcome the limitation of this approach, but still require the same number of incisions as in traditional MIS. Thus, new approaches such as minilaparoscopy, Single Incision Laparoscopic Surgery (SILS) and Natural Orifice Transluminal Endoscopic Surgery (NOTES) have been introduced. In a prospective complete intracavitary approach, the employment of a set of robotic units capable of dedicated tasks is supposed to overcome present drawbacks in terms of dexterity, number of DoFs and triangulation. The modular in vivo robots designed have a diameter of 12 mm, already compatible with most access ports, taking multiple DoFs completely inside the patient. These robotic units have a convenient workspace for the dedicated tasks of image acquisition, retraction and manipulation, while keeping a modular structure with minimal differences between the robotic units. Specifically, three robotic units were designed: a two DoFs camera robot, a two DoFs retraction robot, and a six DoFs manipulator robot. This article illustrates the modular design of the three robotic units, the manufacturing of two modules, and the successful assembly and testing of the camera robot.