Flexible instrument channel insert for scope with real-time position tracking

Abstract

An apparatus, system and method determining a position of an instrument ( 100 ) are provided. A sheath ( 104 ) is configured to fit within an instrument channel of a medical scope. An optical fiber ( 112 ) is disposed within the sheath and a plurality of sensors ( 106 ) is integrated in optical fiber. The sensors are configured to measure deflections and bending in the optical fiber. A fixing mechanism ( 140 ) is sized to fit within the instrument channel in a first state and fixes the sheath within the instrument channel in a second state such that the fixing mechanism anchors the sheath and the optical fiber so that the deflections and bending in the optical fiber are employed to determine a position of the instrument.

1 . An apparatus for determining a position, comprising:
 a sheath ( 104 ) configured to fit within an instrument channel of a medical scope;   at least one optical fiber ( 112 ) disposed within the sheath;   a plurality of sensors ( 106 ) in optical communication with the at least one optical fiber, the sensors being configured to measure deflections and bending in the optical fiber; and   a fixing mechanism ( 140 ) being sized to fit within the instrument channel in a first state and fixing the sheath within the instrument channel in a second state such that the fixing mechanism anchors the sheath and the at least one optical fiber so that the deflections and bending in the optical fiber are employed to determine a position of the instrument.   
     
     
         2 . The apparatus as recited in  claim 1 , wherein the plurality of sensors ( 106 ) includes Fiber Bragg Gratings distributed over a length of the at least one fiber to measure strain. 
     
     
         3 . The apparatus as recited in  claim 1 , wherein the at least one fiber ( 112 ) includes a fiber triplet. 
     
     
         4 . The apparatus as recited in  claim 1 , wherein the fixing mechanism ( 140 ) includes a balloon ( 142 ) and an inflation tube ( 144 ) such that when the balloon is expanded the sheath is anchored within the instrument channel. 
     
     
         5 . The apparatus as recited in  claim 4 , wherein the balloon ( 142 ) includes a torus shape such that the sheath fits within the torus shape and an outside of the torus shape contacts an inside of the instrument channel. 
     
     
         6 . The apparatus as recited in  claim 1 , wherein the fixing mechanism ( 140 ) is positioned at a tip of the instrument channel and produces a strain in the at least one optical fiber to locate the tip of the instrument channel inside a body. 
     
     
         7 . A system for tracking of a portion of a medical device, comprising:
 spatially distributed Fiber Bragg Gratings (FBGs) ( 106 ) integrated on an optical fiber ( 112 ) and disposed within a flexible insert ( 104 ), the flexible insert being positionable within an instrument channel of the medical device;   an optical system ( 114 ) configured to deliver light to the FBGs and receive light from the FBGs such that deflections of the optical fiber are measured;   a computer system ( 130 ) including:
 a shape determination program ( 122 ) configured to compute parameters related to the deflections of the optical fiber and determine a configuration of the flexible insert; and 
 a map volume ( 150 ) acquired from a pre-procedural scan such that based upon a comparison between the configuration of the flexible insert and the map volume a position of the medical device is determined. 
   
     
     
         8 . The system as recited in  claim 7 , wherein the fiber ( 112 ) includes a fiber triplet. 
     
     
         9 . The system as recited in  claim 7 , further comprising a fixing mechanism ( 140 ) sized to fit within the flexible insert in a first state and fixing the flexible insert within the instrument channel in a second state such that the fixing mechanism anchors the flexible insert and the optical fiber. 
     
     
         10 . The system as recited in  claim 9 , wherein the fixing mechanism ( 140 ) includes a balloon ( 142 ) and an inflation tube ( 144 ) such that when the balloon is expanded the flexible insert is anchored within the instrument channel. 
     
     
         11 . The system as recited in  claim 10 , wherein the balloon ( 142 ) includes a torus shape such that the flexible insert fits within the torus shape and an outside of the torus shape contacts an inside of the instrument channel. 
     
     
         12 . The system as recited in  claim 9 , wherein the fixing mechanism ( 140 ) is positioned at a tip of the instrument channel and produces a strain in the optical fiber to locate the tip of the instrument channel inside a body. 
     
     
         13 . A method for tracking of a portion of a medical device, comprising:
 inserting ( 206 ) a sheath into an instrument channel, the sheath including an optical fiber and a plurality of distributed sensors integrated with the optical fiber;   anchoring ( 208 ) the sheath within the instrument channel;   determining ( 212 ) a reference position within a patient using a pre-procedural volume of the patient; and   determining ( 214 ) a shape of the optical fiber using the sensors and correlating the shape with the pre-procedural volume to provide a location of the portion of the medical device.   
     
     
         14 . The method as recited in  claim 13 , further comprising:
 acquiring ( 216 ) video data for reconstructing an image; and   mapping ( 217 ) back the image into real space by using a camera position, shape information derived from the sensors and a calibration matrix which maps image pixels in camera space back into an optical shape sensing reference coordinate system.   
     
     
         15 . The method as recited in  claim 14 , further comprising: registering ( 218 ) reconstructed images dynamically using pre-procedural volumetric imaging to further improve registration quality and navigation accuracy. 
     
     
         16 . The method as recited in  claim 13 , wherein the sensors include a plurality of Fiber Bragg Gratings distributed over a length of the optical fiber and further comprising measuring ( 214 ) deflections using the Fiber Bragg Gratings. 
     
     
         17 . The method as recited in  claim 13 , wherein anchoring ( 208 ) includes providing a balloon and an inflation tube such that when the balloon is expanded the sheath is anchored within the instrument channel. 
     
     
         18 . The method as recited in  claim 17 , wherein the balloon includes a torus shape such that the sheath fits within the torus shape and an outside of the torus shape contacts an inside of the instrument channel. 
     
     
         19 . The method as recited in  claim 13 , wherein anchoring ( 208 ) includes applying pressure to the optical fiber at a tip of the instrument channel to produce a strain in the optical fiber to locate the tip of the instrument channel inside a body.