Lateral Viewing Optical Catheters
The present invention provides improved catheters in which lateral-viewing optical components extend radially outward from the catheter axis to optically interrogate blood vessel walls. One aspect of the invention provides a guidewire-compatible design for this type of catheter. In another aspect of invention, the lateral-viewing optical components are disposed on multiple branches that are collectively disposed within the lumen of an expandable balloon.
1 . A catheter apparatus for optically interrogating a blood vessel wall, comprising:
multiple rod elements disposed along a central shaft of the catheter and extendable radially outward toward a blood vessel wall from an unextended configuration closer to the central axis of the catheter, wherein the rod elements each comprise an optical assembly for transmitting and receiving light from the vessel wall lateral to the central axis of the catheter while the rod-elements contact or are near the wall and wherein each of the optical assemblies is in optical communication with at least one optical fiber that is in communication with a light source for illuminating the vessel wall and/or a detector for detecting light received from the vessel wall; and
an expandable balloon collectively enclosing the multiple rod elements.
2 . The apparatus of claim 1 , wherein the balloon is configured to permit the passage of blood in its expanded state.
3 . The apparatus of claim 1 , wherein the balloon has a lobed structure and each of the rod elements is disposed within a separate lobe of the lobed structure.
4 . The apparatus of claim 3 , wherein the balloon is configured to permit the passage of blood in its expanded state.
5 . The apparatus of claim 1 , wherein the rod elements are at least approximately equally radially spaced about the axis of the catheter.
6 . The apparatus of claim 3 , wherein the rod elements are at least approximately equally radially spaced about the central axis of the catheter.
7 . The apparatus of claim 1 , wherein the multiple rod elements are located near the distal end of the catheter apparatus.
8 . A catheter apparatus for optically interrogating a blood vessel wall, comprising:
a rod element portion near the distal end of the catheter comprising multiple rod elements along a central shaft of the catheter and extendable radially outward toward a blood vessel wall from an unextended configuration closer to the central axis of the catheter, wherein the rod elements each comprise an optical assembly for transmitting and receiving light from the vessel wall lateral to the central axis of the catheter while the rod elements contact or are near the wall and wherein each of the optical assemblies is in optical communication with at least one optical fiber that is in communication with a light source for illuminating the vessel wall and/or a detector for detecting light received from the vessel wall; and
a tip portion of the catheter that extends from the distal end of the rod element portion to the distal end of the catheter,
wherein a guidewire conduit or channel extends from within the central shaft of the rod element portion of the catheter distally through the tip portion of the catheter.
9 . The apparatus of claim 8 , wherein the guidewire channel or conduit opens within the rod element portion of the catheter and at or near the distal end of the tip portion of the catheter.
10 . The apparatus of claim 9 , wherein the guidewire channel or conduit extends though the center of the tip portion of the catheter and exits the center of the distal end of the tip portion.