2. The patient marker according to claim 1, wherein in any given configuration of the marker, only one of the first indicator and the at least one second indicator is accessible.

3. The patient marker according to claim 1, wherein in the first configuration the alignment target fits to the adapter in a plurality of discrete orientations.

4. The patient marker according to claim 3, wherein the discrete orientations comprise two orientations at 180° to each other.

5. The patient marker according to claim 1, wherein in the second configuration the alignment target fits to the base in a plurality of discrete orientations.

AMENDED SHEET (ARTICLE 19)

6. The patient marker according to claim 5, wherein the discrete orientations comprise two orientations at 180° to each other.

7. The patient marker according to claim 1, wherein in the first configuration the angle of orientation comprises a first pair of angles at 180° to each other, and in the second configuration the angle of orientation comprises a second pair of angles at 180° to each other and at 90° to the first pair of angles.

8. The patient marker according to claim 1, wherein the base connections and the first surface adapter connections are configured so that the adapter mates with the base in one single orientation.

9. The patient marker according to claim 1, wherein the at least one second indicator is a divot that acts as a verification point.

10. The patient marker according to claim 1, wherein the at least one second indicator is formed as an extension of a surface of the adapter.

11. The patient marker according to claim 1, wherein one of the at least one second indicator is positioned so that it aligns with and prevents access to the first indicator, while the first surface adapter connections are mated with the base connections.

12. The patient marker according to claim 1, wherein the at least one second indicator comprises two indicators.

13. The patient marker according to claim 12, wherein the angle between lines from each of the two indicators to a central hole of the adapter is obtuse.

14. The patient marker according to claim 1, wherein the at least one second indicator is configured to be touched by a tip of a tool used in the surgery.

15. A computerized method for updating a registration between a patient marker and a patient due to a change in the orientation of the patient marker during a medical procedure, wherein: the patient marker is coupled to an anchoring device via a an adapter, the adapter is coupled to the anchoring device via a base, the anchoring device is attached to the patient, and

AMENDED SHEET (ARTICLE 19) the base comprises at least one base indicator, and the adapter comprises at least one adapter indicator, the method comprising: registering the patient marker to the patient; storing a plurality of distinct orientation values, each orientation value corresponds to a different orientation of the patient marker with respect to the anchoring device and associated with an indicator, wherein the indicator is the at least one base indicator or the at least one adapter indicator, and wherein the orientation value indicates a position of the indicator associated with the orientation value with respect to the patient marker; tracking the position of a tool marker with respect to the patient marker by capturing images of the patient marker and the tool marker via a camera, wherein the tool marker is attached to a tool used in the medical procedure; determining a current marker orientation value based on analysis of one or more images of the patient marker and the tool marker; repeatedly calculating subsequent marker orientation values for images captured by the camera; and if a change in marker orientation value was identified in the subsequent marker orientations with respect to the current marker orientation value, then a change in the patient marker orientation is determined and the registration of the patient marker to the patient is updated accordingly.

16. The method according to claim 15, wherein in any orientation of the patient marker with respect to the anchoring device, only one of the at least one base indicator or the at least one adapter indicator is accessible.

17. The method according to claim 15, wherein the base comprises base connections , the adapter comprises adapter connections and the patient marker comprises marker connections, and wherein the base connections are used to connect the base to the patient marker or to the adapter, and the marker connections are used to connect the patient marker to the base or to the adapter.

AMENDED SHEET (ARTICLE 19)

18. An adapter for providing additional orientations to a patient marker with respect to an anchoring device in image guided surgery, wherein the anchoring device comprises a base having a base axis and a first indicator, the adapter comprising: a first surface configured to be coupled to the base; a second surface, opposite the first surface, configured to be coupled to the patient marker; and at least one second indicator, wherein the patient marker is coupled to the base by coupling the first surface of the adapter with the base and coupling the patient marker with the second surface of the adapter, and wherein when the patient marker is coupled to the anchoring device via the adapter: an angle of orientation of the patient marker about the base axis is indicated by only one of the at least one second indicator, and the first indicator is not accessible.

19. The adapter of claim 18, wherein the at least one second indicator comprises two indicators, and wherein when the patient marker is coupled to the anchoring device via the adapter, only one of the two indicators is accessible.

20. The adapter of claim 18, wherein the at least one second indicator is configured to be touched by a tip of a tool used in the surgery and serve as a verification point.

AMENDED SHEET (ARTICLE 19)