Skeleton model instrument localization

1 . A system comprising:

an instrument having an elongate body; and

a control system communicatively coupled to the instrument, the control system being configured to:

access a branched skeleton model defining a skeleton including a plurality of segments representing respective segments of a luminal network;

identify a segment of the plurality of segments of the branched skeleton model corresponding to a position of a distal end of the instrument;

determine a depth along the segment corresponding to the position of the distal end of the instrument;

access an anatomical map of the luminal network, the anatomical map being an image-based model of the luminal network; and

determine a position of the distal end of the instrument relative to the anatomical map of the luminal network based on the identified segment and the depth along the segment.

2 . The system of claim 1 , wherein the control system is further configured to:

cause a rendering of the anatomical map to be displayed on a display device, the rendering including a representation of the position of the distal end of the instrument relative to the anatomical map.

3 . The system of claim 1 , wherein the plurality of segments of the skeleton are defined relative to center lines of corresponding respective lumen segments of the anatomical map.

4 . The system of claim 1 , wherein the branched skeleton model and the anatomical map are three-dimensional models.

5 . The system of claim 1 , wherein identifying the segment involves determining a unique segment identifier for the segment.

6 . The system of claim 1 , wherein the control system is further configured to identify the segment and determine the depth in response to detecting an introduction of the distal end of the instrument into a portion of the luminal network mapped by the anatomical map.

7 . The system of claim 1 , wherein determining the depth along the segment corresponding to the position of the distal end of the instrument involves:

determining a length of the instrument inserted beyond an access point; and

determining a path length between the access point and the identified segment, wherein the depth is based on the length of the instrument and the path length.

8 . The system of claim 1 , wherein the determined position is restricted to positions within the anatomical map that correspond to the branched skeleton model.

9 . The system of claim 1 , wherein the control system is further configured to determine an orientation of the distal end of the instrument based on the position and electromagnetic sensor data received from the instrument.

10 . A non-transitory computer-readable storage medium having stored thereon instructions that, when executed, cause at least one computing device to:

access a branched skeleton model defining a skeleton including a plurality of segments representing respective segments of a luminal network;

identify a segment of the plurality of segments of the branched skeleton model corresponding to a position of a distal end of an instrument;

determine a depth along the segment corresponding to the position of the distal end of the instrument;

access an anatomical map of the luminal network, the anatomical map being an image-based model of the luminal network; and

determine a position of the distal end of the instrument relative to the anatomical map of the luminal network based on the identified segment and the depth along the segment.

11 . The non-transitory computer-readable storage medium of claim 10 , wherein the instructions, when executed, further cause the at least one computing device to:

cause a rendering of the anatomical map to be displayed on a display device, the rendering including a representation of the distal end of the instrument on the anatomical map.

12 . The non-transitory computer-readable storage medium of claim 11 , wherein the instructions, when executed, further cause the at least one computing device to cause the rendering to represent a rotated view of a target, with the target about a center of rotation.

13 . The non-transitory computer-readable storage medium of claim 10 , wherein the plurality of segments of the skeleton are defined relative to center lines of corresponding respective lumen segments of the anatomical map.

14 . The non-transitory computer-readable storage medium of claim 10 , wherein the branched skeleton model and the anatomical map are three-dimensional models.

15 . The non-transitory computer-readable storage medium of claim 10 , wherein identifying the segment involves determining a unique segment identifier for the segment.

16 . The non-transitory computer-readable storage medium of claim 10 , wherein the instructions, when executed, further cause the at least one computing device to identify the segment and determine the depth in response to detecting the distal end of the instrument in a portion of the luminal network represented in the anatomical map.

17 . The non-transitory computer-readable storage medium of claim 10 , wherein determining the depth along the segment corresponding to the position of the distal end of the instrument involves:

determining a length of the instrument inserted beyond an access point; and

determining a path length between the access point and the identified segment, wherein the depth is based on the length of the instrument and the path length.

18 . The non-transitory computer-readable storage medium of claim 10 , wherein the determined position is restricted to positions within the anatomical map that correspond to the branched skeleton model.

19 . A method of localizing an instrument, the method comprising:

accessing a branched skeleton model defining a skeleton including a plurality of segments representing respective segments of a luminal network;

identifying a segment of the plurality of segments of the branched skeleton model corresponding to a position of a distal end of an instrument;

determining a depth along the segment corresponding to the position of the distal end of the instrument;

accessing an anatomical map of the luminal network, the anatomical map being an image-based model of the luminal network; and

determining a position of the distal end of the instrument relative to the anatomical map of the luminal network based on the identified segment and the depth along the segment.

20 . The method of claim 19 , wherein:

the plurality of segments of the skeleton are defined relative to center lines of corresponding respective lumen segments of the anatomical map;

identifying the segment involves determining a unique segment identifier for the segment; and

the depth is based on a length of the instrument and a path length between an access point and the identified segment.