Hybrid registration method
View Patent ↗A registration method whereby a sensor-based approach is used to establish initial registration and whereby upon the commencement of navigating an endoscope, image-based registration methods are used in order to more accurately maintain the registration between the endoscope location and previously-acquired images. A six-degree-of-freedom location sensor is placed on the probe in order to reduce the number of previously-acquired images that must be compared to a real-time image obtained from the endoscope.
1. A method of registering real-time sensor location data to previously acquired images of a branched network of body lumens comprising:
placing a probe containing a sensor at a distal end thereof into a branched network of body lumens in a patient;
performing an initial registration between a real-time sensor location and a previously acquired image selected a plurality of previously acquired images of said branched network;
receiving data from said sensor to determine an approximate location of said sensor;
using said approximate location of said sensor to create a subgroup of said plurality of images, said subgroup containing one or more previously acquired images corresponding to said approximate location; and,
selecting an image from said subgroup that most accurately corresponds to said approximate location to update said initial registration using an image-based registration technique.
2. The method of claim 1 wherein placing a probe containing a sensor at a distal end thereof comprises placing a probe with a six degree of freedom sensor at a distal end thereof.
3. The method of claim 2 wherein performing an initial registration comprises:
viewing a landmark through an endoscope;
using data from said sensor to project a beam from a tip of said probe to said landmark;
displaying said beam on a monitor;
calculating and recording coordinates of said beam location on said landmark; and,
using said coordinates as a registration point.
4. The method of claim 1 wherein receiving data from said sensor to determine a proximate location of said sensor comprises receiving six degree of freedom data from said sensor.
5. The method of claim 1 wherein placing a probe containing a sensor at a distal end thereof into a branched network of body lumens comprises placing a bronchoscope containing a sensor at a distal end thereof into said branched network of body lumens.
6. The method of claim 5 wherein selecting an image from said subgroup that most accurately corresponds to said approximate location to update said initial registration using an image-based registration technique comprises selecting an image from said subgroup that most closely matches an image being viewed through said bronchoscope.
7. The method of claim 1 wherein performing an initial registration between a real-time sensor location and a previously acquired image selected a plurality of previously acquired images of said branched network comprises performing an initial registration using a 4D registration technique.
8. The method of claim 7 wherein performing an initial registration using a 4D registration technique comprises:
recording an image of a landmark as it moves through at least one breathing cycle;
recording concurrently a position of said sensor;
recording concurrently positions of patient sensors, said patient sensor attached at various locations on said patient;
saving said recordings as a data set for said landmark; and,
using said data set to correlate said position of said sensor to a previously acquired image of said branched network of body lumens.