Method and apparatus for reconstructing bone surfaces during surgery

• US 20030225415A1
• Filed: 01/16/2003
• Published: 12/04/2003
• Est. Priority Date: 01/18/2002
• Status: Active Grant

• Current Assignee: ORTHOsoft ULC. (Zimmer Biomet Holdings, Inc.)
• Original Assignee: ORTHOsoft Holdings Inc. (Zimmer Biomet Holdings, Inc.)
• Inventors: Richard, Alain
• Granted Patent: US 7,715,602 B2
• Time in Patent Office: Days
• US Class Current: 606/102
• CPC Class Codes: A61B 2034/105 Modelling of the patient, e.g. for ligaments or bones
• CPC Class Codes: A61B 2034/2055 Optical tracking systems
• CPC Class Codes: A61B 2034/2068 using pointers, e.g. pointers having reference marks for determining coordinates of body points
• CPC Class Codes: A61B 2034/256 having a database of accessory information, e.g. including context sensitive help or scientific articles
• CPC Class Codes: A61B 34/10 Computer-aided planning, simulation or modelling of surgical operations
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 34/25 User interfaces for surgical systems
• CPC Class Codes: A61B 90/36 Image-producing devices or illumination devices not otherwise provided for

Abstract

There is provided a method for intra-operatively presenting an approximate model of an anatomical structure by collecting a cloud of small surfaces. The cloud of small surfaces is gathered with a registration pointer having an adapted tip capable of making contact with the surface of an structure and registering the normal at the point of contact.

Claims

1. A method for intra-operatively presenting an approximate model of an anatomical structure, the method comprising:

applying a registration tool having a position sensing system associated therewith to a plurality of locations on said anatomical structure,

acquiring input data using said registration tool such that a point is registered for each of said locations;

processing said input data into an approximate model of said anatomical structure; and

displaying said approximate model on an output device.

2. A method as claimed in Claim 1, wherein said processing comprises processing said input data into a cloud of points forming a mosaic and representing a portion of said anatomical structure.

3. A method as claimed in Claim 1, wherein said processing comprises smoothing over a surface represented by said input data to display a smoothed surface of a portion of said anatomical structure.

4. A method as claimed in Claim 3, wherein said processing comprises providing on said smoothed surface said plurality of locations where said input data was acquired.

5. A method as claimed in Claim 4, comprising repeating said acquiring input data after said displaying to adjust said model of said anatomical structure.

6. A method as claimed in Claim 1, wherein said processing comprises reconstructing a three dimensional model using said input data to display a three dimensional model of a portion of said anatomical structure.

7. A method as claimed in Claim 1, wherein said processing comprises reconstructing a three dimensional model using said input data and a known model of said anatomical structure to display a three dimensional model of said anatomical structure.

8. A method as claimed in Claim 1, wherein said processing comprises selecting a known model from a known model database comprising a plurality of known models of varying sizes and shapes and performing an algorithm to determine a best-fit match of said input data onto said known model.

9. A method as claimed in Claim 8, wherein said processing comprises providing on said known model said best-fit match such that said best-fit match is displayed on said output device.

10. A method as claimed in Claim 2, wherein said processing comprises attaching a portion of a known model of said anatomical structure to said mosaic representing a portion of said anatomical structure, said known model representing a remaining portion of said anatomical structure such that an entire model of said anatomical structure is displayed.

11. A method as claimed in Claim 3, wherein said processing comprises attaching a portion of a known model of said anatomical structure to said smoothed surface of a portion of said anatomical structure, said known model representing a remaining portion of said anatomical structure such that an entire model of said anatomical structure is displayed.

12. A method as claimed in Claim 6, wherein said processing comprises attaching a portion of a known model of said anatomical structure to said three dimensional model of a portion of said anatomical structure, said known model representing a remaining portion of said anatomical structure such that an entire model of said anatomical structure is displayed.

13. A method as claimed in Claim 1, wherein said acquiring input data comprises determining a normal to each of said plurality of locations.

14. A method as claimed in Claim 13, wherein said applying a registration tool comprises applying a registration tool having a flat disc surface at a first end.

15. A method as claimed in Claim 14, wherein said applying a registration tool comprises applying a registration tool having a flat disc surface at a second end, said flat disc surface at a second end having different dimensions than said flat disc surface at said first end.

16. A method as claimed in Claim 14, wherein said applying a registration tool comprises applying a registration tool having an intra-operative tool at a second end.

17. A method as claimed in Claim 15, wherein said applying a registration tool comprises selecting one of said first end and said second end to apply to said anatomical surface.

18. A method as claimed in Claim 1, wherein said acquiring input data comprises acquiring data by rotating said tool to indicate to said position sensing system a location has been selected.

19. A method as claimed in Claim 1, wherein said acquiring input data comprises acquiring data by pressing a switch to indicate to said position sensing system a location has been selected.

20. A method as claimed in any one of claims 1 to 19, wherein said anatomical structure is a bone from one of a cadaver and a dummy.

21. A system for displaying an approximate model of a surface of an anatomical structure, the system comprising:

a registration tool having a first end adapted for applying to a surface of an anatomical structure;

a position sensing system associated to said registration tool for acquiring input data representing a plurality of locations on said surface of an anatomical structure such that a position and orientation of said registration tool is determined at each of said plurality of locations;

a storing module for receiving and storing said input data from said position sensing system;

a processing module for processing said input data into an approximate model of said anatomical structure; and

an output device for displaying said approximate model of said anatomical structure.

22. A system as claimed in Claim 21, wherein said processing module processes said input data into a cloud of points forming a mosaic and representing a portion of said anatomical structure.

23. A system as claimed in Claim 21, wherein said processing module smoothes over a surface represented by said input data into a smoothed surface of a portion of said anatomical structure.

24. A system as claimed in Claim 23, wherein said processing module displays on top of said smoothed surface said locations on said anatomical surface where data was acquired.

25. A method as claimed in Claim 21, wherein said processing module reconstructs a three dimensional model, using said input data, into a three dimensional model of a portion of said anatomical structure.

26. A system as claimed in Claim 22, comprising a database of known models of varying dimensions, and wherein said processing module attaches a portion of said known models to a portion of said anatomical structure in order to display an entire model.

27. A system as claimed in Claim 23, comprising a database of known models of varying dimensions, and wherein said processing module attaches a portion of said known models to a portion of said anatomical structure in order to display an entire model.

28. A system as claimed in Claim 25, comprising a database of known models of varying dimensions, and wherein said processing module attaches a portion of said known models to a portion of said anatomical structure in order to display an entire model.

29. A system as claimed in Claim 21, said registration tool having a tip adapted for determining a normal associated with each of said plurality of locations on said surface of an anatomical structure, said input data representing a point and its corresponding normal.

30. A system as claimed in Claim 29, wherein said tip of said registration tool is a flat disc.

31. A system as claimed in Claim 30, wherein said registration tool comprises a second flat disc at an opposite end of said tip, said second flat disc having a smaller radius than said flat disc at said tip.

32. A system as claimed in Claim 30, wherein said registration tool comprises an intra-operative tool at an opposite end of said tip.

33. A system as claimed in Claim 30, wherein said flat disc has a surface area of 1 cm².

34. A registration tool for intra-operatively acquiring data representing an approximate model of an anatomical structure, the tool having an adapted tip at a first end such that an anatomical surface and a normal to said anatomical surface are registered when said tip is applied to said anatomical structure.

35. A registration tool as claimed in Claim 34, wherein said adapted tip is a flat disc.

36. A registration tool as claimed in Claim 35, wherein said flat disc has a surface area of 1 cm².

37. A registration tool as claimed in Claim 34, wherein an intra-operative tool is present at a second end of said tool.

38. A registration tool as claimed in Claim 34, wherein a second flat disc is present on a second end of said tool, said second flat disc having a radius smaller than said flat disc at said first end.

39. A registration tool as Claim 34, wherein a rotation of said tool causes data to be acquired.