Intravascular ultrasound catheter

• US 9,445,784 B2
• Filed: 09/22/2005
• Issued: 09/20/2016
• Est. Priority Date: 09/22/2005
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: O'Keeffe, Daniel
• Primary Examiner(s): Chen, Tse
• Assistant Examiner(s): PARK, PATRICIA JOO YOUNG
• Application Number:
  US11/233,216
• Publication Number:
  US 20070066900A1
• Time in Patent Office: 4,016 Days
• Field of Search: 604523-527, 604/264, 600433-435, 600/585, 600139-140, 600/143
• US Class Current: 1/1
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/445 Details of catheter construction
• CPC Class Codes: A61M 25/0051 made from fenestrated or weakened tubing layer
• CPC Class Codes: A61M 25/0053 having a variable stiffness along the longitudinal axis, e.g. by varying the pitch of the coil or braid
• CPC Class Codes: A61M 25/0054 with regions for increasing flexibility
• CPC Class Codes: A61M 25/0138 having flexible regions as a result of weakened outer material, e.g. slots, slits, cuts, joints or coils

Abstract

An intravascular ultrasound catheter may include a central lumen adapted to receive a drive shaft bearing an ultrasound transducer. The intravascular ultrasound catheter may in some instances exhibit improved flexibility. The catheter can include an inner polymeric layer, an outer polymeric layer and a spiral-cut hypotube that is positioned between the inner polymeric layer and the outer polymeric layer.

Claims

1. An intravascular ultrasound catheter having a distal portion and a proximal portion, the catheter comprising:

an inner polymeric layer, the inner polymeric layer having a plurality of apertures formed therein;

an outer polymeric layer; and

a spiral-cut hypotube, the spiral-cut hypotube positioned between the inner polymeric layer and the outer polymeric layer and extending from the distal portion to the proximal portion of the catheter, the spiral-cut hypotube having a distal end;

wherein the spiral-cut hypotube has a pitch having a rate of change that is dependent upon a distance from the distal end of the hypotube.

2. The intravascular ultrasound catheter of claim 1, wherein the pitch is determined by a formula having a first derivative that is a function of the distance from the distal end of the hypotube.

3. The intravascular ultrasound catheter of claim 1, wherein the spiral-cut hypotube has an exponential pitch.

4. The intravascular ultrasound catheter of claim 1, wherein the spiral-cut hypotube has a pitch given by the formula y=A^(Bx)+C, where y is the pitch, x is the distance from the distal end of the hypotube, A is in a range of about 5 to about 100, B is in a range of about 0.01 to about 1, and C is in a range of about 0 to about 25.

5. The intravascular ultrasound catheter of claim 1, wherein the spiral-cut hypotube has a logarithmic pitch.

6. The intravascular ultrasound catheter of claim 1, wherein the spiral-cut hypotube has a pitch given by the formula y=A+B ln Cx, where y is the pitch, x is the distance from the distal end of the hypotube, A is in a range of about 0 to about 25, B is in a range of about 0.5 to about 25, and C is in a range of about 0.5 to about 100.

7. The intravascular ultrasound catheter of claim 1, wherein the spiral-cut hypotube has a pitch given by the formula y=A+B log Cx, where y is the pitch, x is the distance from the distal end of the hypotube, A is in a range of about 0 to about 100, B is in a range of about 25 to about 200, and C is in a range of about 0.01 to about 100.

8. The intravascular ultrasound catheter of claim 1, wherein the spiral-cut hypotube has a second power pitch.

9. The intravascular ultrasound catheter of claim 1, wherein the spiral-cut hypotube has a pitch given by the formula y=Ax²+Bx+C, where y is the pitch, x is the distance from the distal end of the hypotube, A is in the range of about 0.001 to about 5, B is in the range of about 0 to about 0.001, C is in the range of about 0 to about 100.

10. The intravascular ultrasound catheter of claim 1, wherein the inner polymeric layer defines a lumen adapted to accommodate an intravascular ultrasound drive shaft and transducer.

11. The intravascular ultrasound catheter of claim 1, wherein at least one of the outer polymeric layer and the inner polymeric layer extends distally from the distal end of the spiral-cut hypotube.

12. An intravascular ultrasound catheter having a distal portion and a proximal portion, the catheter comprising:

an inner polymeric layer;

an outer polymeric layer;

a spiral-cut hypotube, the spiral-cut hypotube positioned between the inner polymeric layer and the outer polymeric layer and extending from the distal portion to the proximal portion of the catheter, the spiral-cut hypotube having a distal end;

wherein the spiral-cut hypotube has a pitch having a rate of change that is dependent upon a distance from the distal end of the hypotube; and

wherein the spiral-cut hypotube comprises a machined kerf, and the inner polymeric layer comprises a plurality of apertures in fluid communication with the machined kerf.

13. The intravascular ultrasound catheter of claim 12, wherein the outer polymeric layer comprises a plurality of apertures in fluid communication with the machined kerf.

14. An intravascular ultrasound assembly, comprising:

an intravascular ultrasound drive shaft having a distal end;

an ultrasound transducer positioned near the distal end of the drive shaft; and

a catheter adapted to receive the ultrasound drive shaft, the catheter comprising;

an inner polymeric layer, the inner polymeric layer defining a lumen adapted to accommodate the intravascular ultrasound drive shaft;

an outer polymeric layer; and

a spiral-cut hypotube positioned between the inner polymeric layer and the outer polymeric layer and extending from a distal portion to a proximal portion of the catheter, the spiral-cut hypotube having a distal end.

15. The intravascular ultrasound assembly of claim 14, wherein at least one of the outer polymeric layer and the inner polymeric layer extends distally from the distal end of the spiral-cut hypotube.

16. The intravascular ultrasound assembly of claim 14, wherein the spiral-cut hypotube has a pitch defining distance between adjacent turnings.

17. The intravascular ultrasound assembly of claim 16, wherein the pitch varies as a function of distance from the distal end of the spiral-cut hypotube.

18. The intravascular ultrasound assembly of claim 16, wherein the pitch has a rate of change that is a function of distance from the distal end of the spiral-cut hypotube.

19. The intravascular ultrasound assembly of claim 16, wherein the spiral-cut hypotube has an exponential pitch given by the formula y=A^(Bx)+C, where y is the pitch, x is a distance from the distal end of the hypotube, A is in a range of about 5 to about 100, B is in a range of about 0.01 to about 1, and C is in a range of about 0 to about 25.

20. The intravascular ultrasound assembly of claim 16, wherein the spiral-cut hypotube has a logarithmic pitch given by the formula y=A+B ln Cx, where y is the pitch, x is a distance from the distal end of the hypotube, A is in a range of about 0 to about 25, B is in a range of about 0.5 to about 25, and C is in a range of about 0.5 to about 100.

21. The intravascular ultrasound assembly of claim 16, wherein the spiral-cut hypotube has a logarithmic pitch given by the formula y=A+B log Cx, where y is the pitch, x is a distance from the distal end of the hypotube, A is in a range of about 0 to about 100, B is in a range of about 25 to about 200, and C is in a range of about 0.01 to about 100.

22. The intravascular ultrasound assembly of claim 16, wherein the spiral-cut hypotube has a pitch given by the formula y=Ax²+Bx+C, where y is the pitch, x is a distance from the distal end of the hypotube, A is in the range of about 0.001 to about 5, B is in the range of about 0 to about 0.001, C is in the range of about 0 to about 100.