Computer-assisted surgery with electromagnetic tracking

A system for tracking at least one tool relative to a bone in computer-assisted surgery, comprising:

• a processing unit;
• and
• a non-transitory computer-readable memory communicatively coupled to the processing unit and comprising computer-readable program instructions executable by the processing unit for:
• calibrating a surface of a bone and/or tool relative to at least one electromagnetic sensor by registering a fixed geometrical relation of points of the surface of the bone and/or tool relative to the at least one electromagnetic sensor;
• continuously emitting an electromagnetic field in a surgical volume incorporating the at least one electromagnetic sensor on the bone and/or tool;
• sensing the electromagnetic field with the at least one electromagnetic sensor and continuously receiving a signal indicative of a position and/or orientation of the at least one electromagnetic sensor relative to the emitting of electromagnetic field;
• processing the signal to determine the position and/or orientation of the at least one electromagnetic sensor;
• and
• continuously tracking and outputting a first position and/or orientation of the bone and/or tool using the geometrical data and the position and/or orientation of the at least one electromagnetic sensor.