Figure 66-1 Degrees of freedom (DOFs) in motion. A, Conventional laparoscopic instruments have only 4 DOFs and grip. Insertion (i.e., movement in the z axis), roll, and movement along the x and y axis outside the body relative to a fulcrum point constitute the 4 DOFs. B, Depiction of the EndoWrist instrument with two added intracorporeal joints produce 6 DOFs along with grip. (A and B, © 1999 Intuitive Surgical, Inc., Sunnyvale, CA.)