Systems, Methods and Devices for Correlating Reference Locations Using Image Data

• US 20090268955A1
• Filed: 04/23/2009
• Published: 10/29/2009
• Est. Priority Date: 04/23/2008
• Status: Active Grant

• Current Assignee: Auris Health, Inc. (Johnson & Johnson)
• Original Assignee: Hansen Medical Incorporated (Johnson & Johnson)
• Inventors: Koolwal, Aditya, Barbagli, Federico, Carlson, Christopher R.
• Granted Patent: US 8,270,694 B2
• Time in Patent Office: Days
• US Class Current: 382/128
• CPC Class Codes: A61B 2034/2051 Electromagnetic tracking systems
• CPC Class Codes: A61B 2090/364 Correlation of different images or relation of image positions in respect to the body
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/4245 involving determining the position of the probe, e.g. with respect to an external reference frame or to the patient
• CPC Class Codes: A61B 8/483 involving the acquisition of a 3D volume of data
• CPC Class Codes: A61B 90/36 Image-producing devices or illumination devices not otherwise provided for
• CPC Class Codes: G06N 7/01 Probabilistic graphical models, e.g. probabilistic networks

Abstract

A variety of embodiments relate to systems, methods, circuits and devices are implemented to perform location-based correlations. One such embodiment relates to a circuit-implemented method for use with an actual probe within an anatomical structure. For a virtual probe at a virtual location within a model of the anatomical structure, virtual image data captured by the virtual probe is generated. The virtual image data is assessed through a probabilistic comparison of the virtual image data to actual image data captured by the actual probe at an actual location. Based upon the assessment, a correlation is updated between the actual location of the actual probe and a sensed location of the actual probe to provide synchronicity between the sensed location and actual location. For maintaining the synchronicity between a subsequently sensed location and subsequent actual location, the assessment is used to select a new virtual location for the virtual probe.

Claims

1. A circuit-implemented method for use with an actual probe within an anatomical structure, the method comprising:

for a virtual probe at a virtual location within a model of the anatomical structure, generating virtual image data captured by the virtual probe;

assessing the virtual image data through a probabilistic comparison of the virtual image data to actual image data captured by the actual probe at an actual location;

based upon the assessment, updating a correlation between the actual location of the actual probe and a sensed location of the actual probe to provide synchronicity between the sensed location and actual location; and

for maintaining the synchronicity between a subsequently sensed location and subsequent actual location, using the assessment to select a new virtual location for the virtual probe.

2. The method of claim 1, further including the steps of applying weights to a plurality of virtual locations for the virtual probe according to a Bayesian-based probability determination using the assessment of the correlation between the actual location of the actual probe and a sensed location of the actual probe;

selecting a subset of virtual locations from the plurality of virtual locations using a uniform distribution across the probability-weighted plurality of virtual locations; and

assessing virtual image data for the subset of virtual locations to update the weights.

3. The method of claim 1, further including the step of excluding one or more virtual locations from selection based upon a determined probability level for the one or more virtual locations and probability threshold level.

4. The method of claim 1, wherein the model includes a surface mesh model of the anatomical structure.

5. The method of claim 1, wherein the synchronicity is sufficiently maintained to allow real-time tracking of the probe during a surgical procedure.

6. A system comprising:

a first circuit module to, for a virtual probe at a virtual location within a model of the anatomical structure, generate virtual image data captured by the virtual probe;

a second circuit module to, a first circuit module assess the virtual image data through a probabilistic comparison of the virtual image data to actual image data captured by the actual probe at an actual location;

a third circuit module to, based upon the assessment, update a correlation between the actual location of the actual probe and a sensed location of the actual probe to provide synchronicity between the sensed location and actual location; and

a fourth circuit module to, for maintaining the synchronicity between a subsequently sensed location and subsequent actual location, use the assessment to select a new virtual location for the virtual probe.

7. The system of claim 6, further including the actual probe that includes an image capture sensor for capturing the actual image data.

8. The system of claim 7, wherein the probe includes a catheter.

9. The system of claim 6, further including a position sensor for determining the sensed location of the probe.

10. The system of claim 9, wherein the position sensor includes an electroanatomic mapping system.

11. A circuit-implemented method for correlating an actual reference point to a virtual reference point corresponding to a surface mesh model of an anatomical structure, the method comprising:

for a probe with a known position relative to the actual reference point, selecting a set of virtual poses relative to the virtual reference point as a function of virtual pose weights;

creating, for the virtual poses, virtual image data by applying the virtual poses to the model;

generating correlation scores to the virtual poses as a function of correlation between the captured image data and the virtual image data; and

updating the virtual pose weights as a function of the correlation scores.

12. The method of claim 11, further including the steps of increasing an effective resolution of the image data before repeating the steps of selecting a set of virtual poses and generating correlation scores.

13. The method of claim 11, further including the step of removing virtual poses that are below a threshold correlation score.

14. The method of claim 11, wherein the captured image data represents a two-dimensional image slice of the structure captured by ultrasound imaging.

15. The method of claim 11, wherein the step of generating correlation scores includes probability scoring that is conditioned by previously generated correlations and a normalized mutual information correlation metric.

16. The method of claim 11, further including the steps of

determining an estimated pose for the probe from the set of virtual poses,

determining an offset between the actual reference point and the virtual reference point as a function of the estimated pose and the surface mesh model.

17. The method of claim 16, further including the steps of determining a plurality of n estimated poses from a series of n images and wherein the step of determining an offset includes a least-squares estimate according to the plurality of n estimated poses.

18. The method of claim 16, further including the step of determining the reference location associated with the probe using a reference electrode subject to variation from patient movements.

19. The method of claim 11, further including the step of selecting the random or pseudo-random set of virtual poses for the probe from a probability distribution of all possible poses as a function of the correlation scores and constrained by a size of the model of the structure.

20. A computer-readable medium programmed with instructions that when executed by a processor perform the steps of

for a virtual probe at a virtual location within a model of the anatomical structure, generating virtual image data captured by the virtual probe;

assessing the virtual image data through a probabilistic comparison of the virtual image data to actual image data captured by the actual probe at an actual location;

based upon the assessment, updating a correlation between the actual location of the actual probe and a sensed location of the actual probe to provide synchronicity between the sensed location and actual location; and

for maintaining the synchronicity between a subsequently sensed location and subsequent actual location, using the assessment to select a new virtual location for the virtual probe.