US Patent 8986196 Minimally invasive surgery instrument assembly with reduced cross section

A surgical instrument extends through a guide tube and exits at an intermediate position of the guide tube. The instrument includes a parallel motion mechanism that changes the position of a distal end of the surgical instrument without changing the orientation of the distal end. An image capture component is at the distal end of the guide tube, and a joint allows the image capture component to move while the intermediate position remains stationary. The configuration allows a cross section of the guide tube to be oblong. In some aspects, a joint for the image capture component is placed between exit ports for surgical instruments, which allows the guide tube cross section to be further reduced.