A surgical retractor and a method of minimally invasive surgery, wherein the surgical retractor includes ribs and a mechanism for transferring of linear and rotational movements of the ribs and wherein each rib can be easily replaced without use of any additional tools. The core may have three layers, A, B and C, four layers, A, B, C and D, five layers, A, B, C, D and E or up to six layers, A, B, C, D, E and F. Each electric distribution system includes command electronics in which a configuration file is downloaded allocating an installation status to each of the protectionswitching components. The drive tube passes through a positioning plate which defines a second hole provided with locking edges engaged or disengaged with end edges of the lock snapping plate.