Dynamic deformation tracking for navigation bronchoscopy

Abstract

The present invention provides a system and method for tracking the movement of a catheter within the airways of the lungs. [Solution] The deformable model of the lung represents the airways of the lung as airway segments joined at branching points. Deformation of the lung model is performed using modifications to the angles and / or positions of the airway segments relative to each other. The initial model may be generated, for example, based on segmentation of CT images. The baseline deformable registration of the initial model to the patient's lung shape at the start of the procedure may be established from catheter position measurements along several different paths. Optionally, the baseline registration is dynamic according to the respiratory phase. Compared to the baseline registration, real-time changes in lung shape may be modeled by using position sensors distributed along the catheter body and using further measurements acquired using the catheter as the catheter navigates to the target.

Claims

1. A method for modeling the deformed state of branched anatomical structures through which an intervention device is navigated, Accessing a baseline model constructed using the imaged shapes of the branching and branching points of the aforementioned branched anatomical structures, Accessing one or more measurements of the shape and / or position of the intervention device performed using the intervention device while it is inserted into the branched anatomical structure, Based on the one or more measurements, calculate the deformation that defines the modification of the baseline model, The modified model is generated by dynamically modifying the baseline model according to the aforementioned modification, The method comprising displaying a dynamically changing image representing the branched anatomical structure in a deformed state.

2. The method according to claim 1, wherein the dynamically changing image of the displayed branched anatomical structure deforms with respiration.

3. The method according to claim 1, comprising displaying a CT slice including the current position of the intervention device within the anatomical structure, along with the dynamically changing image.

4. The method according to claim 3, wherein the displayed CT slice is deformed according to the calculated deformation.

5. The method according to claim 1, comprising displaying a CT strip along the path of the intervention device in the three-dimensional display of the dynamically changing image.

6. The method according to claim 5, comprising displaying a CT strip as a two-dimensional image and projecting the intervention device and / or target onto the image.

7. The method according to claim 1, comprising displaying an object in the dynamically changing image, wherein the position of the object is updated according to the deformation state of the branched anatomical structure.

8. The method according to claim 7, comprising associating the position of the object with the position of at least one segment of the branched anatomical structure, and moving the object in accordance with the movement of the associated at least one segment.

9. The method according to claim 1, wherein the image also represents a slice of a 3D image of the branched anatomical structure in a known correspondence with a skeletonized model of the branched anatomical structure, the slice being selected to extend along a portion of the displayed image corresponding to a branch along which the intervention device extends.

10. The method according to claim 9, wherein the known correspondence between the skeletonized model of the branched anatomical structure and the 3D image of the branched anatomical structure is established by deriving the skeletonized model from the segmentation of the 3D image.

11. The method according to claim 9, wherein the displayed image includes a three-dimensional representation of the branched anatomical structure, and the slices of the three-dimensional image are curved from a planar representation to conform to the three-dimensional configuration of the interventional device.

12. The method according to claim 9, wherein the displayed image represents the intervention device flattened into a planar representation, and the slice of the 3D image is flattened together with it.

13. Receiving reference measurements from one or more reference sensors attached to fixed anatomical positions of the body including the branched anatomical structures, The method according to claim 1, wherein the calculation includes using the reference measurement to align one or more measurements of the shape and / or position of the intervention device with respect to the branched anatomical structure.

14. The method according to claim 1, comprising receiving a reference measurement from one or more reference sensors and using the reference measurement to assign respiratory phase to measurements of the shape and / or position of the intervention device.

15. A method of displaying features along winding pathways through anatomical structures, Accessing 3D images of the aforementioned anatomical structures, To define the pathways passing through the aforementioned anatomical structures, The spatial correspondence between a location along the aforementioned path and a location in the 3D image, A surface extending through the 3D image, including the location in the 3D image, Calculating and The method includes displaying a 3D image showing the path extending through 3D space, along with data from the position of the 3D image of the anatomical structure defined by the surface, The pathway is repeatedly defined using measurements of at least one dynamically changing parameter of the shape of the anatomical structure, The method wherein the calculation and the display are repeated each time the path is repeatedly defined.

16. The method according to claim 15, wherein the surface is calculated as a strip extending along the path on both sides of the path.

17. The method according to claim 16, wherein the strip extends approximately equidistant on both sides of the path.

18. The method according to claim 15, comprising accessing a 3D model of a portion of the anatomical structure that is in a known spatial correspondence with the aforementioned path, and including a display of the 3D model of the anatomical structure within the 3D display image, wherein the 3D model of the portion of the anatomical structure also changes dynamically.

19. The method according to claim 15, wherein the measurement of at least one dynamically changing parameter includes a measurement of the position and / or shape of an intervention device positioned along the path.

20. The method according to claim 15, wherein the measured value of the at least one dynamically changing parameter is associated with the phase of respiration by the time of measurement.

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