Therapeutic catheter with imaging
Ablation systems and methods of the present disclosure include a catheter including one or more image sensors. The one or more image sensors can facilitate, for example, positioning an ablation electrode at a treatment site of an anatomic structure and, additionally or alternatively, can facilitate controlling delivery of therapeutic energy to a treatment site of an anatomic structure.
1. A catheter, comprising:
a shaft having a proximal end portion and a distal end portion opposite the proximal end portion;
an ablation electrode at the distal end portion of the shaft including a deformable portion, wherein the deformable portion of the ablation electrode is movable between a compressed state and an uncompressed state, and wherein the ablation electrode, when in the uncompressed state, is configured to allow blood to flow therethrough; and
at least one ultrasound transducer, wherein an ultrasound transducer of the at least one ultrasound transducer is mounted at a fixed location relative to the shaft within a volume at least partially defined by the deformable portion of the ablation electrode or is mounted to the deformable portion of the ablation electrode, and
wherein the ultrasound transducer is generally directed in a distal direction such that the ultrasound transducer is configured to image (a) at least a portion of the ablation electrode, (b) tissue of an anatomic structure in which the catheter is positioned, or (c) a combination thereof.
2. The catheter of claim 1 wherein the ultrasound transducer is radially symmetric.
3. The catheter of claim 1 wherein the at least one ultrasound transducer includes an A-mode ultrasound transducer.
4. The catheter of claim 1 wherein:
the ablation electrode includes an outer portion and an inner portion opposite the outer portion;
the ultrasound transducer is disposed within the volume at least partially defined by the ablation electrode; and
when the ablation electrode is in the uncompressed state and, in the absence of external force, the ultrasound transducer is spaced apart from an inner portion of the ablation electrode.
5. The catheter of claim 4 wherein, when the ablation electrode is in the uncompressed state and in the absence of the external force, the ultrasound transducer is spaced apart from the inner portion of the ablation electrode by a distance greater than a focal length of the ultrasound transducer.
6. The catheter of claim 4 wherein the ablation electrode is movable in a direction away from the ultrasound transducer as the ablation electrode expands from the compressed state to the uncompressed state.
7. The catheter of claim 4 , further comprising a fluid delivery element, and wherein:
the fluid delivery element is coupled to the distal end portion of the shaft and extends into the volume at least partially defined by the deformable portion of the ablation electrode; and
the ultrasound transducer is mounted on the fluid delivery element.
8. The catheter of claim 1 wherein:
the ablation electrode includes a plurality of struts; and
the ultrasound transducer has a beam width at least twice as wide as a respective transverse dimension of at least some of the struts.
9. The catheter of claim 1 wherein the at least one ultrasound transducer includes an ultrasound transducer array.
10. The catheter of claim 1 wherein the ultrasound transducer is configured to acquire image data regarding contact between the ablation electrode and the tissue along a plane substantially perpendicular to the shaft.
11. The catheter of claim 1 wherein, in the uncompressed state and in the absence of an external force, the ablation electrode is (a) symmetric in a radial direction relative to the shaft, (b) symmetric in an axial direction relative to the shaft, or (c) a combination thereof.
12. The catheter of claim 11 wherein, in the uncompressed state and in the absence of the external force, the ablation electrode is ellipsoidal.
13. A method, comprising:
receiving one or more images captured by at least one ultrasound transducer of a catheter positioned within an anatomic structure of a patient, wherein:
the catheter includes (i) a shaft having a distal end portion positioned within the anatomic structure, (ii) a deformable ablation electrode at the distal end portion of the shaft, and (ii) the at least one ultrasound transducer,
the at least one ultrasound transducer includes an ultrasound transducer mounted on the ablation electrode or—mounted at a fixed location relative to the shaft within a volume at least partially defined by the ablation electrode,
the ablation electrode is transformable between a compressed state and an uncompressed state corresponding to a shape of the ablation electrode in the absence of an external force, and
the one or more images are received when the ablation electrode is in a deployed state corresponding to the uncompressed state or to a partially compressed state of the ablation electrode between the compressed state and the uncompressed state; and
based, at least in part, on the one or more images, determining displacement of the ablation electrode from the uncompressed state.
14. The method of claim 13 wherein determining displacement of the ablation electrode includes determining displacement of the ablation electrode from the uncompressed state in an axial direction relative to the shaft, displacement of the ablation electrode from the uncompressed state in a radial direction relative to the shaft, or a combination thereof.
15. The method of claim 13 wherein determining displacement of the ablation electrode includes determining a shape of the ablation electrode corresponding to the displacement.
16. The method of claim 15 further comprising transmitting an indication of the shape of the ablation electrode to a graphical user interface.
17. The method of claim 13 , further comprising determining, based at least in part on the one or more images, apposition of the ablation electrode to tissue of the anatomic structure.
18. The method of claim 13 , further comprising detecting, based at least in part on the determined displacement of the ablation electrode from the uncompressed state, contact between the ablation electrode and tissue of the anatomic structure.
19. The method of claim 18 wherein detecting the contact includes identifying regions of the ablation electrode contacting the tissue.
20. The method of claim 13 further comprising determining, based at least in part on the determined displacement of the ablation electrode from the uncompressed state, a direction and magnitude of a contact force between the ablation electrode and tissue of the anatomic structure.
21. The method of claim 13 , further comprising determining, based at least in part on the determined displacement of the ablation electrode from the uncompressed state, a shape of the anatomic structure local to the ablation electrode.
22. The method of claim 21 , further comprising generating a graphical representation of the anatomic structure based, at least in part, on the determined shape of the anatomic structure local to the ablation electrode.
23. The method of claim 13 , further comprising:
delivering electrical energy to tissue of the anatomic structure; and
detecting, based at least in part on the one or more images, lesion progress while delivering the electrical energy to the tissue.
24. The method of claim 23 wherein detecting the lesion progress includes detecting microbubbles formed while the tissue is ablated via the electrical energy.