Catheter for in vivo imaging
A catheter for in vivo imaging comprising a monolithic outer sheath terminating in a monolithic atraumatic tip having a guidewire lumen. The catheter for in vivo imaging comprising a rotary drive shaft that passes through a central lumen of the monolithic outer sheath to impart rotary motion.
1. A catheter for in vivo imaging comprising:
a catheter sheath body defining a central lumen and a distal tip, the central lumen terminating at the distal tip and the distal tip having a guidewire lumen formed therein, the guidewire lumen being separate from the central lumen and having a guidewire entrance port and a guidewire exit port, the guidewire entrance port and the guidewire exit port each being positioned distal to the termination of the central lumen; and
an optical train positioned within the central lumen, the optical train comprising a rotary drive shaft configured to rotate a distal end imaging assembly about a longitudinal axis, the rotary drive shaft comprising a proximal hypotube shaft having a distal end overlapping a proximal end of a distal single-layer stranded hollow core shaft, wherein the stranded hollow core shaft comprises helically wound metal wires fixedly engaged with neighboring metal wires on their respective outer surfaces.
2. The catheter of claim 1 , wherein the catheter sheath body is a monolithic sheath body that includes a single continuous piece of material containing no joints from the proximal end of the sheath body to the distal end of the distal tip.
3. The catheter of claim 1 , wherein the imaging assembly comprises an optical fiber, a gradient index lens, a prism, a housing concentrically engaged about the optical fiber, the gradient index lens, and the prism, and wherein the rotary drive shaft is coupled to a proximal end of the housing.
4. The catheter of claim 3 , wherein the housing further comprises a metal tube having an opening in a wall thereof, the opening being in optical alignment with the prism.
5. The catheter of claim 3 , wherein the rotary drive shaft defines a rotary drive shaft lumen and the distal stranded hollow core shaft of the rotary drive shaft is coupled to the housing, wherein the optical fiber passes axially through the rotary drive shaft lumen.
6. The catheter of claim 5 , wherein the stranded hollow core shaft comprises a plurality of wires wound in a helical configuration.
7. The catheter of claim 1 , further comprising a second housing coupled to the proximal hypotube of the rotary drive shaft.
8. The catheter of claim 1 , wherein the monolithic sheath body further comprises a sheath material which is at least partially optically transparent.
9. The catheter of claim 1 , wherein the guidewire entrance port opens to a distal end of the distal tip and the guidewire exit port opens to a side wall of the distal tip.
10. The catheter of claim 1 , wherein a distal portion of the sheath body has a greater flexibility that a proximal portion of the sheath body.
11. The catheter of claim 1 , wherein the durometer of the sheath is varied along the length of the monolithic catheter sheath to reduce non-uniform rotational distortion.
12. The catheter of claim 1 , wherein the guidewire lumen includes a diameter that is varied from the proximal portion to the distal tip.