Method and system for determining the location of a medical instrument relative to a body structure

A system for determining a location of an object relative to a body structure, comprising:

• a) a device for providing a location of a first point or first plane corresponding to a first part of the object relative to a second point or second plane corresponding to a second part of the object, said second part different from the first part;
• b) a body marker device;
• c) a first detection device for detecting a location of the body marker device relative to the body structure when the body marker device is stationary relative to the body structure;
• d) a second detection device for detecting a location of the first point or first plane relative to the body marker device;
• and
• e) a computational unit configured to calculate, without using a marker device attached to the object, a location of the second part of the object relative to the location of the body structure, said calculation based on the location of the first point or first plane relative to the second point or second plane, the location of the body marker device relative to the body structure, and the location of the first point or first plane relative to the marker device.

A computer program embodied on a non-transitory computer readable storage medium for determining a location of an object relative to a body structure, wherein a body marker device is attached to the body structure, and said object is positioned relative to the body structure;

• comprising:
• code that provides a location of a first point or first plane corresponding to a first part of the object relative to a second point or second plane corresponding to a second part of the object, said second part different from said first part;
• code that detects a location of the body marker device relative to the body structure;
• code that detects a location of the first point or first plane relative to the marker device;
• and
• code that calculates, without using a marker device attached to the object, a relative location of the second part of the object relative to the location of the body structure, said calculation based on the location of the first point or first plane relative to the second point or second plane, the location of the marker device relative to the body structure, and the location of the first point or first plane relative to the marker device.