Computer-implemented technique for determining a coordinate transformation for surgical navigation

Patent metadata

Field	Value
Publication number	US-9901407-B2
Application number	US-201314905690-A
Country	US
Kind code	B2
Filing date	Aug 23, 2013
Priority date	Aug 23, 2013
Publication date	Feb 27, 2018
Grant date	Feb 27, 2018

Abstract

A technique for determining a transformation between a navigation reference coordinate system ( 302 ) for navigation of a surgical device ( 150 ) relative to patient image data and an image coordinate system ( 304 ) in which the patient image data define a shape of a patient surface is provided. A computer-implemented method implementation of that technique comprises receiving multiple data sets that have been taken from different perspectives of the patient surface. Feature coordinates of multiple features ( 170 ) identifiable in the picture data sets are determined from the picture data sets and in the navigation reference coordinate system ( 302 ). From the feature coordinates, a shape model of the patient surface in the navigation reference coordinate system ( 302 ) is determined. Then, surface matching between the shape model and the shape of the patient surface defined by the patient image data is applied to determine the transformation (T 1 ) between the navigation reference coordinate system ( 302 ) and the image coordinate system ( 304 ).

First claim

The invention claimed is:

1. A system for determining a transformation between a navigation reference coordinate system for navigation of a surgical device relative to patient image data and an image coordinate system in which the patient image data define a shape of a patient surface of a patient, the system comprising:
a first camera movable relative to the patient upon taking picture data sets from different perspectives;
an interface adapted to receive the picture data sets from the first camera, wherein the first camera is a video camera and the picture data sets are received from the video camera in the form of a video data stream; and
a processor adapted to determine, from the picture data sets and in the navigation reference coordinate system, feature coordinates of multiple features identifiable in the picture data sets, to determine, from the feature coordinates, a shape model of the patient surface in the navigation reference coordinate system, and to determine a transformation between the navigation reference coordinate system and the image coordinate system using surface matching between the shape model and the shape of the patient surface defined by the patient image data.

2. A device for determining a transformation between a navigation reference coordinate system for navigation of a surgical device relative to patient image data and an image coordinate system in which the patient image data define a shape of a patient surface, the device comprising:
an interface adapted to receive multiple picture data sets from a first camera movable relative to the patient upon taking the picture data sets from different perspectives of the patient surface, wherein the first camera is a video camera and the picture data sets are received from the video camera in the form of a video data stream; and
a processor adapted to determine, from the picture data sets and in the navigation reference coordinate system, feature coordinates of multiple features identifiable in the picture data sets, to determine, from the feature coordinates, a shape model of the patient surface in the navigation reference coordinate system, and to determine a transformation between the navigation reference coordinate system and the image coordinate system using surface matching between the shape model and the shape of the patient surface defined by the patient image data.

3. A method of determining a transformation between a navigation reference coordinate system for navigation of a surgical device relative to patient image data and an image coordinate system in which the patient image data define a shape of a patient surface, the method comprising:
receiving multiple picture data sets from a first camera movable relative to the patient upon taking the picture data sets from different perspectives of the patient surface, wherein the first camera is a video camera and the picture data sets are received from the video camera in the form of a video data stream;
determining, from the picture data sets and in the navigation reference coordinate system, feature coordinates of multiple features identifiable in the picture data sets;
determining, from the feature coordinates, a shape model of the patient surface in the navigation reference coordinate system; and
determining a transformation between the navigation reference coordinate system and the image coordinate system using surface matching between the shape model and the shape of the patient surface defined by the patient image data.

4. The method of claim 3 , wherein
the first camera is at least one of a handheld camera and attachable to the surgical device.

5. The method of claim 3 , wherein
several of the features identifiable in at least one picture data set are grouped to form a feature group, wherein at least one of a position and orientation is attributable to each feature group.

6. The method of claim 3 , wherein
at least one of the feature coordinates and the shape model is determined using one or more of a structure-from-motion technique, a simultaneous localization and mapping technique, and a pose estimation technique.

7. The method of claim 6 , wherein
at least one of the feature coordinates and the shape model is determined using a simultaneous localization and mapping technique; and wherein
simultaneous localization and mapping technique is applied to the feature groups.

8. The method of claim 7 , wherein
the structure-from-motion technique builds feature tracks for individual features identifiable in the picture data sets from different perspectives and triangulation based on different perspectives is applied to individual feature tracks.

9. The method of claim 3 , wherein
the shape model is represented by a point cloud.

10. The method of claim 3 , further comprising
determining the navigation reference coordinate system on the basis of at least some of the features identified in the picture data sets.

11. The method of claim 3 , wherein
the feature coordinates are determined for one or more tracker features of a patient tracking device for use during surgical navigation, wherein the patient tracking device is at least partially identifiable in the picture data sets and has a fixed position relative to the patient.

12. The method of claim 3 , wherein
the feature coordinates are determined for one or more tracker features of a patient tracking device for use during surgical navigation, wherein the patient tracking device is at least partially identifiable in the picture data sets and has a fixed position relative to the patient; and wherein
the tracker features at least partially define the navigation reference coordinate system.

13. The method of claim 3 , wherein
the feature coordinates are determined for one or more anatomic patient features identifiable in the picture data sets.

14. The method of claim 13 , further comprising
identifying the one or more anatomic patient features in the picture data sets using generic knowledge about anatomic features.

15. The method of claim 13 , wherein
several of the features identifiable in at least one picture data set are grouped to form a feature group, wherein at least one of a position and orientation is attributable to each feature group; wherein
at least one of the feature coordinates and the shape model is determined using a simultaneous localization and mapping technique; wherein
simultaneous localization and mapping is applied to the feature groups; and wherein
the navigation reference coordinate system is at least partially determined from the anatomic patient features.

16. The method of claim 13 , wherein
the shape model is at least partially determined from the anatomic patient features.

17. The method of claim 3 , wherein
the feature coordinates are determined for one or more patch features of a feature patch applied to the patient and at least partially identifiable in the picture data sets.

18. The method of claim 17 , wherein
the method further comprises determining the navigation reference coordinate system on the basis of at least some of the features identified in the picture data sets; and wherein
the navigation reference coordinate system is at least partially determined from the patch features.

19. The method of claim 17 , wherein
the feature patch conforms to the patient surface and wherein the shape model is at least partially determined from the patch features.

20. The method of claim 3 , further comprising
deriving a scaling factor from the surface matching, and w

Assignees

• Stryker Leibinger Gmbh & Co Kg
• Stryker European Holdings I Llc

Inventors

• Breisacher Jochen
• Stawiaski Jean
• Reiff Tobias

Classifications

• A61B2034/105

  Modelling of the patient, e.g. for ligaments or bones · CPC title

• A61B2034/2055

  Optical tracking systems · CPC title

• G06F19/3437

  Physics · mapped topic

• A61B2090/364

  Correlation of different images or relation of image positions in respect to the body · CPC title

• A61B2090/367

  creating a 3D dataset from 2D images using position information · CPC title