Customized surgical fixture

• US 6,738,657 B1
• Filed: 12/04/2002
• Issued: 05/18/2004
• Est. Priority Date: 07/06/1998
• Status: Expired due to Term

• Current Assignee: Neutar, LLC
• Original Assignee: Neutar, LLC
• Inventors: Franklin, Ronald J., Haer, Frederick C., Franck, Joel I.
• Primary Examiner(s): Jaworski, Francis J.
• Assistant Examiner(s): Jain, Ruby
• Application Number:
  US09/869,551
• Time in Patent Office: 531 Days
• Field of Search: 600/437, 600/429, 600/426, 600/424, 600/407, 600/411, 600/427, 600/414, 606/130, 606/73, 164/45
• US Class Current: 600/429
• CPC Class Codes: A61B 2034/105 Modelling of the patient, e.g. for ligaments or bones
• CPC Class Codes: A61B 2034/107 Visualisation of planned trajectories or target regions
• CPC Class Codes: A61B 2034/2055 Optical tracking systems
• CPC Class Codes: A61B 2034/2072 Reference field transducer attached to an instrument or patient
• 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 2090/363 Use of fiducial points
• CPC Class Codes: A61B 2090/3983 Reference marker arrangements for use with image guided surgery
• 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 90/11 with guides for needles or instruments, e.g. arcuate slides or ball joints
• CPC Class Codes: A61B 90/14 Fixators for body parts, e.g. skull clamps; Constructional details of fixators, e.g. pins
• CPC Class Codes: A61B 90/39 Markers, e.g. radio-opaque or breast lesions markers
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 50/02 for controlling or regulating additive manufacturing processes
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing

Abstract

A customized surgical fixture (400) is formed by scanning a body to form a three-dimensional image of the body, and then identifying in the image a target (310) in the body, and mounting points or structures (330) on the body. A model, such as a computer solid model, of the fixture (400) is specified in accordance with the locations of the target (310) and mounting structures (330) or points. The fixture (400) is formed in accordance with the model of the fixture (400), for example using a rapid prototyping and tooling machine. When attached to the body, the fixture (400) can be used to guide a surgical instrument (610) into the body, for example, by using a mechanical guide (600) attached to the fixture (400) or using a remote sensing device (1300) that tracks the relative position of the customized fixture (400) and the surgical instrument.

Claims

1. A method for forming and using a customized fixture comprising:

determining data characterizing a plurality of attachment locations on a body;

computing a digital model of the shape of the customized fixture, including determining said shape to mate with the attachment locations on the body and determining a location for attaching a tracking device to the fixture; and

computing registration data that is sufficient to relate coordinates of a point in an internal coordinate system that is fixed relative to the attachment locations on the body with coordinates of said point in an external coordinate system in which a position of the tracking device that is attached to the body using the customized fixture is known.

2. The method of claim 1 further comprising using the registration data to relate coordinates of a point in the internal coordinate system and coordinates of said point in the external coordinate system.

3. The method of claim 2 wherein using the registration data includes transforming the coordinates of the point in the internal coordinate system to coordinates of said point in the external coordinate system.

4. The method of claim 2 wherein using the registration data includes transforming the coordinates of the point in the external coordinate system to coordinates of said point in the internal coordinate system.

5. The method of claim 4 further comprising using the coordinates of the point in the internal coordinate system to display a representation of the point in conjunction with a graphical image of the body.

6. The method of claim 4 wherein the point in the external coordinate system corresponds to a point that is fixed relative to an instrument that is free to move relative to the body.

7. The method of claim 6 further comprising tracking a position of the tracking device and a position of the instrument in the external coordinate system.

8. The method of claim 1 further comprising determining data characterizing the physical structure of the body by processing a three-dimensional scan of the body.

9. The method of claim 2 wherein determining data characterizing the attachment locations on the body includes identifying the attachment locations using the data characterizing the physical structure of the body.

10. The method of claim 9 wherein determining data characterizing the attachment locations includes determining positions of a plurality of bone anchors that were attached to the body at the time the three-dimensional scan was generated.

11. The method of claim 9 wherein determining data characterizing the attachment locations includes identifying a contour of a surface of the body for mating with the customized fixture.

12. The method of claim 1 further comprising providing the customized fixture.

13. The method of claim 12 wherein providing the customized fixture includes fabricating the customized fixture according to the digital model.

14. The method of claim 12 wherein fabricating the customized fixture includes forming a unitary structure of the fixture using a computer-controlled process.

15. The method of claim 14 wherein forming the unitary structure includes using a rapid prototyping and tooling (RPT) technique.

16. The method of claim 12 further comprising attaching the tracking device to the customized fixture at the determined location for attaching the tracking device.

17. The method of claim 16 wherein attaching the tracking device includes attaching a tracking frame that includes a plurality of tracking markers.

18. The method of claim 16 wherein the tracking device includes a plurality of tracking markers and attaching the tracking device includes attaching each of the tracking markers directly to the customized fixture.

19. The method of claim 16 further comprising attaching the customized fixture to the body by mating the mounting points with the mounting locations.

20. The method of claim 19 wherein the mounting locations include bone anchors attached to the body and attaching the customized fixture includes attaching the fixture to the bone anchors.

21. The method of claim 19 further comprising tracking a position of the tracking device in the external coordinate system.

22. The method of claim 21 wherein the tracking device includes a plurality of tracking markers and tracking the position of the tracking device includes tracking each of the markers relative to a sensing device.

23. The method of claim 22 wherein the external coordinate system is fixed relative to the sensing device and tracking each of the markers includes determining coordinates of the markers in the external coordinate system.

24. Software stored on a computer readable medium for causing a computing system to perform functions comprising:

determining data characterizing a plurality of attachment locations on a body;

computing a digital model of the shape of a customized fixture, including determining said shape to mate with the attachment locations on the body and determining a location for attaching a tracking device to the fixture; and

computing registration data that is sufficient to relate coordinates of a point in an internal coordinate system that is fixed relative to the attachment locations on the body with coordinates of said point in an external coordinate system in which a position of the tracking device that is attached to the body using the customized fixture is known.

25. The software of claim 24 wherein the functions further comprise using the registration data to relate coordinates of a point in the internal coordinate system and coordinates of said point in the external coordinate system.