Occlusion-crossing devices, atherectomy devices, and imaging
Described herein are methods for producing and identifying characteristic (“crescent shaped”) regions indicative of an atherectomy plaque within a vessel, and systems and devices adapted to take advantage of this characteristic region.
1. A method of identifying a plaque mass within a vessel, the method comprising:
inserting a device into the vessel, the device applying a force on the vessel to cause the vessel wall to stretch away from the device;
imaging the vessel to create an image;
identifying a location and orientation of a plurality of pointed crescent-shaped structures extending radially from a substantially semi-circular central portion in the image, the substantially semi-circular central portion having a substantially rounded portion and a substantially linear portion, each pointed crescent-shaped structure extending from a junction of the substantially rounded portion and the substantially linear portion; and
determining a position of the plaque mass within the vessel relative to the device based upon the identified location and orientation of the pointed crescent-shaped structures in the image.
2. The method of claim 1 , wherein imaging the vessel comprises imaging the vessel with optical coherence tomography.
3. The method of claim 1 , wherein imaging the vessel comprises imaging with an imaging sensor attached to the device.
4. The method of claim 3 , further comprising orienting the device within the vessel based on the location and orientation of the crescent-shaped structures.
5. The method of claim 4 , wherein orienting the device comprises pointing a directional cutter of the device at the position of the plaque mass.
6. The method of claim 4 , wherein orienting the device comprises directing the device based upon the relationship between markers in the image created by a portion of the device and the location and orientation of the crescent-shaped structures.
7. The method of claim 3 , further comprising rotating the imaging sensor to obtain the image.
8. The method of claim 1 , wherein identifying a location and orientation of a plurality of pointed crescent-shaped structures comprises determining which direction a tip of each crescent-shaped structure points.
9. The method of claim 8 , wherein determining a position of the plaque mass comprises identifying a location between two pointed crescent-shaped structures in which the tips of the two pointed crescent-shaped structures point towards one another.