TWO-PART MEDICAL TRACKING MARKER

• US 20120184839A1
• Filed: 09/30/2009
• Published: 07/19/2012
• Est. Priority Date: 09/30/2009
• Status: Active Grant

• Current Assignee: Brainlab AG
• Original Assignee: Brainlab AG
• Inventors: Woerlein, Swen
• Granted Patent: US 9,044,269 B2
• Time in Patent Office: Days
• US Class Current: 600/407
• CPC Class Codes: A61B 2017/00876 magnetic
• CPC Class Codes: A61B 2090/3983 Reference marker arrangements for use with image guided surgery
• CPC Class Codes: A61B 46/00 Surgical drapes
• CPC Class Codes: A61B 46/10 specially adapted for instruments, e.g. microscopes
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers
• CPC Class Codes: A61B 90/40 Apparatus fixed or close to patients specially adapted for providing an aseptic surgical environment

Abstract

The invention relates to a medical tracking marker (12) for localizing or tracking an object (10) by means of a medical tracking system (30), said marker comprising a first part (1) which is to be fixed on the object (10), and a second part (2) which is to be connected to the first part (1), wherein the first and second parts (1, 2) comprise interconnecting elements (4, 6) which are adapted to provide a positionally determined connection between the first part (1) and the second part (2) while the first part is located under a surgical drape (20) and the second part is located above said surgical drape (20), with the drape (20) placed between the two parts (1, 2). The invention also relates to a method of referencing an object (10) using a medical navigation system, wherein a medical tracking marker such as has been described above is localized or tracked by means of a medical tracking system (30), and wherein the object is registered by means of the first part (1) of the marker (12) in a preliminary referencing step, in particular for imaging purposes, which is later adapted to form a final referencing step for navigation using the second part (2) which has been placed on the first part in a positionally defined, pre-determined manner.

Claims

1. A medical tracking marker for localizing or tracking an object by means of a medical tracking system, said marker comprising a first part which is to be fixed on the object, and a second part which is to be connected to the first part, characterized in that the first and second parts comprise interconnecting elements which are adapted to provide a positionally determined connection between the first part and the second part while the first part is located under a surgical drape and the second part is located above said surgical drape, with the drape placed between the two parts.

2. The medical tracking marker according to claim 1, characterized in that the parts are not in direct contact when connected and in particular that their interconnecting elements are not in direct contact with each other.

3. The medical tracking marker according to claim 1, characterized in that said interconnecting elements, when connected, are spaced apart by at least a distance corresponding to the thickness of a surgical drape, wherein the connection bridges said distance.

4. The medical tracking marker according to claim 1, characterized in that the interconnecting elements do not penetrate the drape when connected.

5. The medical tracking marker according to claim 1, characterized in that when connected, the parts—

in particular the interconnecting elements—

clamp the drape without penetrating it.

6. The medical tracking marker according to claim 1, characterized in that the connection between the parts is established by using forces which act over a distance, in particular magnetic or electrostatic forces.

7. The medical tracking marker according to claim 6, characterized in that the parts are provided with two different magnetic or static domains in the connecting area, in particular on each surface involved in the connection, thereby securing a predetermined alignment of the parts which are connected without contacting each other.

8. The medical tracking marker according to claim 1, characterized in that the parts are connected by a positive connection between the interconnecting elements, wherein the drape is accommodated between said elements which in particular form a bayonet catch or quarter-turn fastener.

9. The medical tracking marker according to claim 1, characterized in that the parts are connected by a frictional engagement between the interconnecting elements, wherein the drape is accommodated between said elements.

10. The medical tracking marker according to claim 1, characterized in that the parts are connected by any combination of the connections according to claim 6.

11. The medical tracking marker according to claim 1, characterized in that the first part of said marker is fixed on the object non-invasively, in particular adhesively bonded onto the object or fixed there by means of adhesive tape.

12. The medical tracking marker according to claim 1, characterized in that one of the first and second parts, in particular the second part, or both parts are provided with a reflective surface which can be detected by the tracking system.

13. A method of referencing an object using a medical navigation system, wherein a medical tracking marker in accordance with claim 1, is localized or tracked by means of a medical tracking system, and wherein the object is referenced by means of the first part of the marker in a preliminary referencing step, in particular for imaging purposes, which is later adapted to form a final referencing step for navigation using the second part which has been placed on the first part in a positionally defined, pre-determined manner.

14. The method according to claim 13, wherein the adapting step compensates for and takes into account the shift in the position of the marker which occurs when the second part is placed on the first part, and in particular takes into account one or more of the following:

the thickness of the drape;

a specific shape of the second part;

characteristics of or inaccuracies in the system connecting the parts;

a shift in the skin;

a movement of the tracking system.

15. The method of claim 14, wherein the shift in position is taken into account by ignoring markers which are found to have shifted during the medical navigation.

16. A program which, when it is running on a computer or is loaded onto a computer, causes the computer to perform a method in accordance with claim 13.

17. A computer program storage medium which comprises a computer program according to claim 16.