Adaptive navigation technique for navigating a catheter through a body channel or cavity
A method for using an assembled three-dimensional image to construct a three-dimensional model for determining a path through a lumen network to a target. The three-dimensional model is automatically registered to an actual location of a probe by tracking and recording the positions of the probe and continually adjusting the registration between the model and a display of the probe position. The registration algorithm becomes dynamic (elastic) as the probe approaches smaller lumens in the periphery of the network where movement has a bigger impact on the registration between the model and the probe display.
1. A method of registering a computer model of a lumen network to a patient's lumen network while navigating the patient's lumen network with an electromagnetic (EM) sensor coupled to a probe, the method comprising:
displaying the computer model of the lumen network;
receiving successive data points pertaining to a location of the EM sensor while the EM sensor is navigated inside a patient's lumen network;
establishing a sensor path of the EM sensor within the patient's lumen network based on the successive data points;
iteratively registering the computer model of the lumen network to the sensor path by registering a path shape on the computer model of the lumen network to the sensor path based on a diameter of a lumen in which the EM sensor is located relative to a size of the probe; and
updating the displayed computer model of the lumen network based on the registering.
2. The method according to claim 1 , further comprising:
displaying an indicator of the sensor location on the computer model of the lumen network; and
updating the displayed location of the indicator based on the registering.
3. The method according to claim 2 , wherein the displayed location of the indicator is updated such that the indicator appears within a lumen of the computer model of the lumen network.
4. The method according to claim 1 , wherein iteratively registering the computer model of the lumen network to the sensor path includes matching a lumen of the computer model of the lumen network to the sensor path.
5. The method of claim 1 , wherein iteratively registering the computer model of the lumen network to the sensor path includes rigidly registering a path shape on the computer model of the lumen network to the sensor path.
6. The method of claim 1 , wherein iteratively registering the computer model of the lumen network to the sensor path includes deformably registering a path shape on the computer model of a lumen network to the sensor path.
7. The method of claim 1 , wherein iteratively registering the computer model of the lumen network to the sensor path includes:
rigidly registering the path shape on the computer model of the lumen network to the sensor path when the diameter of the lumen in which the EM sensor is located is large relative to a diameter of the probe; and
deformably registering the path shape on the computer model of the lumen network to the sensor path when the diameter of the lumen in which the EM sensor is located approaches the diameter of the probe.
8. The method according to claim 1 , further comprising
determining a plurality of projected points along a pathway through the computer model of the lumen network;
pairing at least a portion of the received data points with at least a portion of the plurality of projected points; and
adjusting the computer model of the lumen network based on the pairing.
9. The method according to claim 8 , wherein the pairing is based on one or more of:
a minimal distance relative to a local lumen diameter, and
a minimal difference in orientation.
10. The method according to claim 1 , wherein the received data points include data regarding a current position of the EM sensor.
11. The method according to claim 1 , wherein the received data points include data regarding a current orientation of the EM sensor.
12. The method according to claim 1 , further comprising:
determining that a portion of the received data points pertaining to the location of the EM sensor are outliers; and
removing data points determined to be outliers.
13. The method of claim 1 , wherein the EM sensor is coupled to a distal portion of the probe.
14. The method of claim 1 , further comprising:
generating the path shape from a trachea to an exit point; and
extending the patient's lumen network by a linear branch that connects the exit point and a target center.
15. The method of claim 1 , further comprising:
skeletonizing the computer model of the lumen network by extracting centerlines; and
identifying branch points in the computer model of the lumen network at intersections of the centerlines.
16. A method of registering a computer model of a lumen network to a patient's lumen network while navigating the patient's lumen network with a probe, the method comprising:
receiving successive data points pertaining to a location of a probe within a patient's lumen network from an EM sensor coupled to the probe;
establishing a path of the probe within the patient's lumen network based on the successive data points received from the EM sensor; and
iteratively registering a path shape on the computer model of the lumen network to the probe path based on a diameter of a lumen in which the probe is located relative to a diameter of the probe.
17. The method according to claim 16 , further comprising:
displaying the computer model of the lumen network; and
updating the displayed computer model of the lumen network based on the iterative registration.
18. The method according to claim 16 , further comprising:
determining that a portion of the received data points pertaining to the location of the probe are outliers; and
removing data points determined to be outliers.
19. The method according to claim 16 , further comprising registering the computer model of the lumen network to the probe path based on the iterative registration.
20. A method of registering a computer model of a lumen network to a patient's lumen network while navigating the patient's lumen network with a probe, the method comprising:
receiving successive data points pertaining to a location of a probe within a patient's lumen network from an EM sensor coupled to the probe;
determining that a portion of the received data points pertaining to the location of the probe are outliers;
removing data points determined to be outliers;
establishing a path of the probe within the patient's lumen network based on the successive data points received from the EM sensor; and
iteratively registering the computer model of the lumen network to the probe path based on a diameter of a lumen in which the probe is located relative to a diameter of the probe.