US Patent 11272989 Multi-level positional tracking

Disclosed herein are various systems and methods for an improved minimally invasive surgical tracking system. As disclosed herein, a computer assisted surgical system (CASS) may include an internal tracking device that obtains relative locational data of one or more surgical tools not trackable via a global tracking system. The internal tracking device having an external portion that is trackable global tracking system. Based on the known characteristics and location of the internal tracking device the CASS determines the location of the one or more surgical tools relative to the patient and other objects in the operating room.