OCCLUSION-CROSSING DEVICES

1 . An occlusion crossing device, comprising:

an outer shaft defining a lumen, wherein the outer shaft includes a distal opening that is angled relative to a central axis of the outer shaft to form a tapered distal end; and

an inner shaft configured to translate within the outer shaft and to rotate with respect to the outer shaft, the inner shaft including:

a distal end having cutting edges; and

an imaging window on a lateral side of the inner shaft proximal to the cutting edges, wherein when at last a portion of the cutting edges are fully extended distally through the distal opening of the outer shaft, the tapered distal end of the outer shaft is arranged to occlude the imaging window at a defined rotational position as the inner shaft is rotated relative to the outer shaft to provide a registration mark for imaging.

2 . The occlusion crossing device of claim 1 , wherein the inner shaft is configured to be removed proximally from the outer shaft.

3 . The occlusion crossing device of claim 1 , wherein the tapered distal end is shaped to act as a wedge or scoop for facilitating pushing through an occlusion within a blood vessel.

4 . The occlusion crossing device of claim 1 , wherein a distal portion of the occlusion crossing device is configured to bend laterally away from a distal-most tip of the tapered distal end of the outer shaft.

5 . The occlusion crossing device of claim 1 , wherein the outer shaft comprises a backbone region at a distal end portion of the outer shaft that is configured to bias lateral bending of the distal end portion in a plane that includes a midline of the central axis and the tapered distal end.

6 . The occlusion crossing device of claim 1 , wherein the tapered distal end of the outer shaft around the distal opening is circumferentially beveled inward from an outer surface of the outer shaft.

7 . The occlusion crossing device of claim 1 , wherein the inner shaft comprises a fiber optic coupled to the imaging window and extending proximally through the inner shaft.

8 . The occlusion crossing device of claim 1 , wherein the cutting edges of the distal end of the inner shaft include:

a first region having a first diameter; and

a second region distal to the first region, wherein the second region has a second diameter that is less than 60% of the first diameter.

9 . The occlusion crossing device of claim 1 , wherein the outer shaft includes:

a flexible tube; and

a selective bending support that at least partially surrounds a distal end of the flexible tube, the selective bending support including a backbone that extends longitudinally along a portion of the flexible tube, wherein the backbone is configured to bias lateral bending of the distal end of the outer shaft.

10 . An occlusion crossing device, comprising:

an outer shaft defining a lumen and a distal opening that is angled relative to a central axis of the outer shaft to form a distal-most tip, wherein the distal opening is circumferentially beveled inward from an outer surface of the outer shaft, further wherein a distal portion of the outer shaft includes a backbone that extends longitudinally along at least a portion of the outer shaft, wherein the backbone is configured to bias lateral bending of the distal portion;

an inner shaft extending within the lumen and configured to rotate with respect to the outer shaft, the inner shaft including a distal end having a drill tip that is configured to extend through the distal opening.

11 . The occlusion crossing device of claim 10 , further comprising an imaging element coupled to the inner shaft and configured to rotate with the inner shaft.

12 . The occlusion crossing device of claim 11 , wherein the imaging element comprises an optical coherence tomography (OCT) imaging window.

13 . The occlusion crossing device of claim 11 , wherein the distal-most tip is configured to pass in front of the imaging element as the imaging element rotates, forming a registration marker.

14 . The occlusion crossing device of claim 11 , wherein the imaging element comprises an optical fiber that extends within the inner shaft and substantially along a central axis of the inner shaft.

15 . The occlusion crossing device of claim 10 , further comprising a handle attached to the inner shaft and the outer shaft and configured rotate the inner shaft.

16 . The occlusion crossing device of claim 15 , wherein the handle is configured to rotate the drill tip at speeds of greater than 500 rpm.

17 . The occlusion crossing device of claim 10 , wherein the backbone is part of a selective bending support of the outer shaft, the selective bending support at least partially surrounding a flexible tube of the outer shaft.

18 . The occlusion crossing device of claim 17 , wherein the flexible tube comprises a braided material.

19 . The occlusion crossing device of claim 18 , wherein the braided material is made of a metal material that is surrounded by a polymeric laminate.

20 . The occlusion crossing device of claim 10 , wherein the outer shaft includes circumferential cuts that extend at least partially through a thickness of the outer shaft, wherein the backbone is between the circumferential cuts.

21 . The occlusion crossing device of claim 10 , wherein the outer shaft includes multiple backbones.

22 . The occlusion crossing device of claim 10 , wherein the inner shaft is removably coupled with the outer shaft.