Endoscope structures and techniques for navigating to a target in branched structure

Abstract

Systems and methods employing a small gauge steerable catheter including a locatable guide with a sheath, particularly as an enhancement to a bronchoscope. A typical procedure is as follows. The location of a target in a reference coordinate system is detected or imported. The catheter is navigated to the target which tracking the distal tip of the guide in the reference coordinate system. Insertion of the catheter is typically via a working channel of a convention bronchoscope. Once the tip of the catheter is positioned at the target, the guide is withdrawn, leaving the sheath secured in place. The sheath is then used as a guide channel to direct a medical tool to target.

1 . (canceled) 
     
     
         2 . A method for displaying steering of a flexible catheter through a branched structure to a target location, the method comprising:
 measuring a position and a pointing direction of a tip of the flexible catheter relative to a three-dimensional frame of reference using a position measuring system including a position sensor located near the tip of the flexible catheter;   displaying a designated target location relative to the three-dimensional frame of reference;   displaying advancement of the flexible catheter into a branched structure; and   displaying a representation of at least one parameter defined by a geometrical relation between the pointing direction of the tip of the flexible catheter and a direction from the tip of the flexible catheter towards the target location, wherein the at least one parameter includes a direction of deflection required to bring the pointing direction of the flexible catheter into alignment with the target location.   
     
     
         3 . The method of  claim 2 , wherein the at least one parameter includes an angular deviation between the pointing direction of the tip of the flexible catheter and a direction from the tip of the flexible catheter towards the target location. 
     
     
         4 . The method of  claim 2 , wherein the representation of at least one parameter is displayed in the context of a representation of a view taken along the pointing direction of the tip of the flexible catheter. 
     
     
         5 . The method of  claim 2 , wherein the position sensor is part of a six-degrees-of-freedom position measuring system measuring the position and attitude of the tip of the flexible catheter in three translational and three rotational degrees of freedom. 
     
     
         6 . The method of  claim 2 , wherein the flexible catheter includes a multi-directional steering mechanism configured for selectively deflecting a distal portion of the flexible catheter in any one of at least three different directions. 
     
     
         7 . The method of  claim 2 , further comprising:
 monitoring by use of the position sensor a path traveled by the tip of the flexible catheter; and   displaying a representation of the path traveled together with a current position of the tip, the representation being projected as viewed from at least one direction non-parallel to the pointing direction of the tip.   
     
     
         8 . The method of  claim 2 , further comprising:
 receiving a designation of a target location with respect to computerized tomography data generated from the branched structure; and   registering the computerized tomography data with the three-dimensional frame of reference.   
     
     
         9 . The method of  claim 8 , further comprising:
 receiving designation of an intended route through the branched structure; and   displaying a representation of the intended route together with a current position of the tip, the representation being projected as viewed from at least one direction non-parallel to the pointing direction of the tip.   
     
     
         10 . The method of  claim 8 , further comprising:
 detecting a current position of the position sensor;   generating from the computerized tomography data a virtual endoscopy image corresponding to an image that would be viewed by a camera located in predefined spatial relationship and alignment relative to the position sensor; and   displaying the virtual endoscopy image.   
     
     
         11 . The method of  claim 2 , wherein the branched structure is a lung structure. 
     
     
         12 . The method of  claim 2 , wherein the flexible catheter further includes: a sheath having a lumen extending from a proximal insertion opening to a distal opening; and a locatable guide configured for insertion through the proximal opening of the sheath to an inserted position extending along the lumen to the distal opening, the locatable guide including at least part of an imaging system deployed for taking optical images of a region beyond the distal opening, the method further comprising:
 guiding the flexible catheter to a position with the tip adjacent to the target location; and   withdrawing the locatable guide from the lumen to leave the lumen available for insertion of a medical tool.   
     
     
         13 . The method of  claim 12 , wherein the locatable guide further includes an image sensor configured to generate an image in the pointing direction of the flexible catheter, the image sensor being withdrawn from the sheath as part of the locatable guide. 
     
     
         14 . The method of  claim 2 , wherein the flexible catheter is a flexible endoscope. 
     
     
         15 . The method of  claim 2 , wherein the flexible catheter is a flexible bronchoscope. 
     
     
         16 . A method for displaying the steering of a catheter through a branched structure to a target location, the method comprising:
 measuring a position and a pointing direction of a tip of the catheter relative to a three-dimensional frame of reference using a position measuring system including a position sensor located near the tip of the catheter;   displaying a designated target location relative to the three-dimensional frame of reference;   displaying advancement of the catheter into a branched structure; and   displaying a representation of at least one parameter defined by a geometrical relation between the pointing direction of the tip of the catheter and a direction from the tip of the catheter towards the target location,   wherein the catheter is a flexible bronchoscope.   
     
     
         17 . A method comprising:
 determining a position and a pointing direction of a tip of a flexible catheter relative to a three-dimensional frame of reference based on measurements from using a position measuring system including a position sensor located near the tip of the flexible catheter;   displaying a designated target location relative to the three-dimensional frame of reference;   displaying advancement of the flexible catheter through a branched structure;   displaying a three-dimensional graphical representation of an orientation of the tip of the flexible catheter; and   displaying a representation of at least one parameter defined by a geometrical relation between the pointing direction of the tip of the flexible catheter and a direction from the tip of the flexible catheter towards the designated target location.   
     
     
         18 . The method of  claim 17 , further comprising:
 receiving a designation of the designated target location with respect to computerized tomography data generated from the branched structure; and   registering the computerized tomography data with the three-dimensional frame of reference.   
     
     
         19 . The method of  claim 18 , wherein the flexible catheter includes a camera, and
 wherein the method further comprises:   generating a camera view of features within the branched structure;   generating from the computerized tomography data a simulated view of the features, each camera view and a corresponding one of the simulated views constituting a pair of similar views;   receiving designation of a reference point viewed within each of the camera views and a corresponding reference point viewed within each corresponding simulated view; and   deriving from the designated reference points a best fit registration between the computerized tomography data and the three-dimensional frame of reference.   
     
     
         20 . The method of  claim 18 , further comprising:
 receiving designation of an intended route through the branched structure; and   displaying a representation of the intended route together with a current position of the tip, the representation being projected as viewed from at least one direction non-parallel to the pointing direction of the tip.   
     
     
         21 . The method of  claim 17 , wherein the branched structure is a lung structure.