Mechanical manipulator for intuitive control of endoscopic instruments with seven degrees of freedom.

Performing complex tasks such as vascular anastomosis in minimally invasive surgery (MIS) is demanding due to a disturbed hand-eye co-ordination, the application of non-ergonomic instruments with limited number of degrees of freedom (DOFs) and a lack of three-dimensional perception. Robotic tele-manipulatory systems enhance surgical dexterity by providing up to seven DOFs. They allow the surgeon to operate in an ergonomically favourable position with more intuitive manipulation of the instruments. Robotic systems, however, are very bulky, expensive and do not provide any force feedback from the tissue. The aim of our study is to develop a simple mechanical manipulator for MIS. The Minimally Invasive Manipulator (MIM) is a purely mechanical device. When manipulating the handle of the MIM, the surgeon's wrist and grasping movements, which are essential for suturing, are directly transmitted to the deflectable instrument tip in seven DOFs. It gives the surgeon direct control of the instrument tip. First phantom experience indicates that the system functions properly. The MIM provides force feedback to improve safety. A set of MIMs seems to be an economical and compact alternative to robotic systems and will offer more surgeons the capability to perform complex MIS and to shorten their learning curve.