Generic depth indicator for surgical navigational tools

A tracking device for a robotic surgical arm having an end effector, the tracking device comprising:

• a first depth detector configured to securely engage a first portion of a surgical tool passing through the end effector of the robotic surgical arm, the first depth detector including an optical tracker attached to the first depth detector and configured to rotate relative to the first depth detector;
• a second depth detector configured to slidingly engage a second portion of the surgical tool, the second depth detector being configured to be secured at a fixed location relative to the end effector of the robotic surgical arm;
• and
• a compressible spring extending between the first depth detector and the second depth detector,
• wherein a depth of insertion of the surgical tool is determined based, at least in part, on a movement or position of the first depth detector relative to the second depth detector.

A tracking device for a surgical system having an end effector, the tracking device comprising:

• a first depth detector configured to securely engage a first portion of a surgical tool, the first depth detector including an optical tracker attached to the first depth detector and configured to rotate about an axis of the first depth detector;
• a second depth detector configured to slidingly engage a second portion of the surgical tool, the second depth detector supported by a robotic arm, the second depth detector being configured to be disposed at a location whose spatial position is known relative to a body part on which the surgical tool is to operate;
• and
• a compressible spring extending between the first depth detector and the second depth detector,
• wherein a depth of insertion of the surgical tool is determined based, at least in part, on a movement or position of the first depth detector relative to the second depth detector.