Micro-molded anamorphic reflector lens for image guided therapeutic/diagnostic catheters
A catheter system for optical coherence tomography includes an elongate catheter body, an optical fiber in the elongate catheter body, and an anamorphic lens assembly coupled with a distal end of the optical fiber. The optical fiber and the lens assembly are together configured to provide a common path for optical radiation reflected from a target and from a reference interface between the distal end of the optical fiber and the lens assembly.
1. A catheter for optical coherence tomography (OCT), comprising:
an elongate catheter body;
an optical fiber in the elongate catheter body; and
a lens assembly, the lens assembly comprising:
an elongate body having a channel extending therethrough, a distal end of the optical fiber positioned within the channel;
a lens body integral with the elongate body; and
an interface medium within the channel and attaching the lens body to the optical fiber;
wherein the optical fiber and the lens assembly are together configured to provide a common path for optical radiation reflected from a target and from a reference interface formed by the interface medium.
2. The catheter of claim 1 , wherein the lens body comprises a concave lens surface.
3. The catheter of claim 2 , wherein the concave lens surface has a compound radius having a first radius along a first axis that is different from a second radius along a second axis.
4. The catheter of claim 2 , wherein the concave lens surface is positioned opposite from and at an angle relative to the distal end of the optical fiber.
5. The catheter of claim 2 , wherein a tangent of the concave lens surface is at an angle of between about 40 degrees and 50 degrees relative to a longitudinal axis of the optical fiber.
6. The catheter of claim 2 , wherein a radius of curvature of the concave lens surface is between 0.2 mm and 1.5 mm.
7. The catheter of claim 1 , further comprising a reflective coating on the lens body.
8. The catheter of claim 7 , further comprising a source of optical radiation, wherein the reflective coating has a thickness of at least ⅙ of an excitation wavelength of the source of optical radiation.
9. The catheter of claim 7 , wherein the reflective coating comprises gold.
10. The catheter of claim 7 , wherein the reflective coating comprises a dielectric.
11. The catheter of claim 7 , wherein the reflective coating has an optical density of greater than 3.0.
12. The catheter of claim 1 , wherein the reference interface provides a reference reflection of between −28 and −42 dB.
13. The catheter of claim 1 , further comprising a source of optical radiation, receiving electronics configured to receive optical radiation reflected from the reference interface and the target, and a processor to generate an image of the target based upon the optical radiation received by the receiving electronics.
14. The catheter of claim 1 , wherein the lens assembly comprises a polycarbonate material.
15. The catheter of claim 1 , wherein a secondary reflection of optical radiation from an interface between the optical fiber and the lens assembly is less than −60 dB.