Miniature in vivo robots for minimally invasive surgery

Advances in surgical methods have enabled surgery to become less invasive. Many procedures that were once predominantly performed as open procedures are now routinely performed using minimally invasive surgery with improved patient outcomes. Recently, there has been a renewed interest in accessing the surgical environment through a single incision or a natural orifice to further reduce invasiveness. The limitations in visualization and manipulation experienced by surgeons performing traditional laparoscopy through multiple small incisions are intensified when working through a single, constrained insertion point. Many of the current methods for improving triangulation are focused on improving the articulation of existing laparoscopic tools, the use of the da Vinci® Surgical System, or on the development of more compact prototype surgical robots, also based on an externally-actuated platform. Miniature in vivo robots represent a fundamentally different approach to minimally invasive robotic surgery where the entire robot is inserted into the abdomen to perform a surgical intervention. A second generation of planar robots for Natural Orifice Translumenal Endoscopic Surgery, NOTES, were developed that attempt to emulate the use of two laparoscopic tools while using a NOTES platform. These robots have been prototyped and demonstrated in two animal model cholecystectomies. Cholecystectomy is an example of a surgical procedure that is currently performed routinely using a laparoscopic approach. Other, more complicated procedures, such as colon resection, have a more limited acceptance and remain predominantly performed as open procedures. To better understand the design requirements in developing a robotic system for performing a colectomy, a task decomposition for sigmoid colectomy has been performed. This decomposition formed the basis for the design of a dexterous robot prototype for performing this procedure. The design of this prototype robot is presented and results of benchtop testing and two animal model procedures are discussed. The development of this prototype robot represents a step towards the development of dexterous miniature in vivo robots that can help extend the benefits of a minimally invasive approach to more complicated surgical procedures