Design and Actuation of a Snake-Like Robot for Minimally Invasive Surgeries

Endoscopic minimally invasive surgeries (MIS) are being more common procedures in hospitals. Instead of a single large opening, only several small incisions are needed to be opened through the patient to perform the surgery. As such, MIS has better recovery rate and efficiency than convention surgeries. However, the access ports of such surgeries constrain conventional MIS instruments made of straight rigid bodies to limited degrees-of-freedom (DOFs) and distal dexterity. Also, tight and irregular spaces within the human body restrict and complicate the surgery procedure due to the maneuverability of the instruments. To address these challenges and achieve more flexible manipulations inside human body, a new snake-like robotic system was developed combining the usage of springs and support structures and the concept of parallel manipulators using push-pull wire actuation. Such robotic systems are needed due to the limited space of the small access ports opened through the human body during minimally invasive surgeries. Instead of using a central backbone and the multiple plates of the distal dexterity units, a spring was used as the supporting structure of the robot. The characteristics of a spring are exploited in this design to enable the robot to orientate and position with increased maneuverability. A simple support structure is then inserted into the spring to allow for wire actuation. Key design considerations and features are discussed. The prototype of the robotic system is able to achieve five degree of freedoms through the actuation control and show the feasibility of active steering intracorporeal endoscopes.