Pre-calibrated reusable instrument

1. A pre-calibrated reusable instrument assembly, comprising:

an instrument holder;

an instrument held by and movable with respect to the instrument holder between first and second positions, said instrument comprising at least two functional elements, one of the functional elements being positioned for use when the instrument is in the first position, and the other being positioned for use when the instrument is in the second position; and

at least three markers trackable by a medical navigation system, including a first marker moveable with the instrument holder and a second marker movable with the instrument relative to the first marker on the instrument holder such that a movement of the instrument produces a corresponding movement of the second marker between positions respectively corresponding to the first and second positions of the instrument, whereby the navigation system can determine which functional element is positioned for use.

2. The pre-calibrated reusable instrument assembly as set forth in claim 1 , wherein a positional relationship between the at least three markers is indicative of which of the at least two functional elements is positioned for use.

3. The pre-calibrated reusable instrument assembly as set forth in claim 1 , wherein the instrument holder is a grip for the pre-calibrated reusable instrument assembly.

4. The pre-calibrated reusable instrument assembly as set forth in claim 1 , wherein the instrument is mounted within the instrument holder such that the instrument can be shifted with respect to the instrument holder.

5. The pre-calibrated reusable instrument assembly as set forth in claim 1 , wherein the instrument can be shifted along a longitudinal axis of the instrument or the instrument holder.

6. The pre-calibrated reusable instrument assembly as set forth in claim 1 , wherein the instrument is non-rotatably mounted in the instrument holder.

7. The pre-calibrated reusable instrument assembly as set forth in claim 1 , wherein the instrument can be moved into at least two fixed end states.

8. The pre-calibrated reusable instrument assembly as set forth in claim 7 , wherein in the at least two fixed end states of the instrument, at least one of the at least two functional elements is protected by the instrument holder.

9. The pre-calibrated reusable instrument assembly as set forth in claim 1 , wherein the at least two functional elements of the instrument are different from each other.

10. The pre-calibrated reusable instrument assembly as set forth in claim 1 , wherein the at least two functional elements are formed on ends or tips of the instrument.

11. The pre-calibrated reusable instrument assembly as set forth in claim 1 , wherein the second marker is arranged on the instrument.

12. The pre-calibrated reusable instrument assembly as set forth in claim 1 , wherein the first and another of said at least three markers are arranged on the instrument holder.

13. The pre-calibrated reusable instrument assembly as set forth in claim 1 , wherein in a first end state of the instrument the at least three markers form a first triangle, and in a second end state of the instrument the at least three markers form a second triangle, wherein the first triangle and the second triangle are not congruent.

14. A method for identifying a state of a pre-calibrated reusable instrument assembly, wherein the instrument assembly includes an instrument holder, an instrument held by and movable with respect to the instrument holder between first and second positions, said instrument comprising at least two functional elements, one of the functional elements being positioned for use when the instrument is in the first position, and the other being positioned for use when the instrument is in the second position, and at least three markers trackable by a medical navigation system, including a first marker moveable with the instrument holder and a second marker movable with the instrument relative to the first marker on the instrument holder such that a movement of the instrument produces a corresponding movement of the second marker between positions respectively corresponding to the first and second positions of the instrument, comprising:

identifying one of at least two possible marker geometries of the pre-calibrated reusable instrument;

comparing the one identified geometry to pre-stored geometrical information of the pre-calibrated reusable instrument; and

ascertaining the state of the pre-calibrated reusable instrument assembly based on the comparison.

15. A computer program embodied on a non-transitory computer-readable medium for identifying a state of a pre-calibrated reusable instrument assembly, wherein the instrument assembly includes an instrument holder, an instrument held by and movable with respect to the instrument holder, said instrument including at least two functional elements, and at least three markers, wherein at least one of the markers is movable with the instrument relative to the instrument holder such that a movement of the instrument produces a corresponding movement of the at least one marker, comprising code that causes a processor to implement a method as set forth in claim 14 .

16. A system for identifying a state of a pre-calibrated reusable instrument assembly, wherein the instrument assembly includes an instrument holder, an instrument held by and movable with respect to the instrument holder between first and second positions, said instrument including at least two functional elements, one of the functional elements being positioned for use when the instrument is in the first position, and the other being positioned for use when the instrument is in the second position, and at least three markers trackable by a medical navigation system, including a first marker moveable with the instrument holder and a second marker movable with the instrument relative to the first marker on the instrument holder such that a movement of the instrument produces a corresponding movement of the second marker between positions respectively corresponding to the first and second positions of the instrument, comprising:

a processor circuit having a processor and a memory;

an identification sub-system stored in the memory and executable by the processor, the identification sub-system comprising:

logic that identifies one of at least two possible marker geometries of the pre-calibrated reusable instrument assembly;

logic that compares the one identified geometry to pre-stored geometrical information of the pre-calibrated reusable instrument assembly; and

logic that ascertains the state of the pre-calibrated reusable instrument assembly based on the comparison.