CATHETER AND A METHOD AND AN APPARATUS FOR MAKING SUCH CATHETER

• US 20100280498A1
• Filed: 04/15/2008
• Published: 11/04/2010
• Est. Priority Date: 06/20/2007
• Status: Active Grant

• Current Assignee: Unomedical A/S
• Original Assignee: Unomedical A/S
• Inventors: Olsen, Jan Kent
• Granted Patent: US 9,186,480 B2
• Time in Patent Office: Days
• US Class Current: 604/544
• CPC Class Codes: A61M 25/001 Forming the tip of a catheter, e.g. bevelling process, join or taper
• CPC Class Codes: A61M 25/0015 Making lateral openings in a catheter tube, e.g. holes, slits, ports, piercings of guidewire ports; Methods for processing the holes, e.g. smoothing the edges
• CPC Class Codes: A61M 25/0017 specially adapted for long-term hygiene care, e.g. urethral or indwelling catheters to prevent infections
• CPC Class Codes: A61M 25/007 Side holes, e.g. their profiles or arrangements; Provisions to keep side holes unblocked
• CPC Class Codes: B26F 1/0015 specially adapted for perforating tubes
• CPC Class Codes: B29C 2793/0018 for making a hole
• CPC Class Codes: B29C 37/02 Deburring or deflashing thermal deburring in general B23D79/005
• CPC Class Codes: B29L 2031/7542 Catheters
• CPC Class Codes: Y10T 83/0414 At localized area [e.g., line of separation]

Abstract

The present invention concerns a catheter for medical purposes, such as for insertion into a body opening for draining fluids, wherein the catheter comprises a flexible tube having a distal end region wherein the tube is provided with at least one draining opening, characterised in that the peripheral edge on the outside of the tube is provided with a curvature for creating a smooth transition between the exterior surface of the tube and the substantially radially oriented cut constituting the opening side and wherein said curvature is a rounded edge with a curvature radius between 0.2-0.6 mm. The invention further concerns a method of making such catheter and an apparatus for performing this method.

Claims

1. A method of making a catheter comprising a polymer tube with openings therein, said method comprising:

providing a tube and punching at least one opening in the tube by advancing a cutting member in a substantially radial direction into the wall of the tube, and providing the at least one opening with a three-dimensional edge contour, whereby central, straight sections of the edge contour of the opening become lower than the outer contour of the tube, when the tube is viewed from the side, and end sections of the edge contour of the opening curve outwards towards the straight outer contour of the tube itself;

manipulating an outer peripheral edge region of the at least one opening by rounding the peripheral edge of the punched opening in the tube by

advancing a heated forming member a predetermined distance into the opening and providing the peripheral edge of the opening with a shape corresponding to a shape of a distal end of the forming member, said distal end of the forming member is provided with a rounded shoulder transition portion at a foot of the distal end and with a protrusion extending from said shoulder transition region, said protrusion having a form fitting the opening in the tube,

said distal end of the forming member being shaped so that it matches the three-dimensional contour of the edge of the punched opening in the tube, a contour of the shoulder transition portion of the distal end of the forming member is shaped with two end sections with substantially straight sections therebetween, corresponding to the end sections and the central straight sections of the edge contour of the opening, respectively, the substantially straight sections of the contour of the shoulder transition portion extend substantially in the same plane, of the contour of the shoulder transition portion curve out of said plane;

holding said heated forming member in said advanced position for a predetermined holding time; and

retracting the forming member.

2. A method according to claim 1, further comprising removing loose cut-away material after the punching action.

3. A method according to claim 1, further comprising providing the forming member in a forming station positioned in a movable frame the forming member is mounted in floating arrangement in the forming station, the forming member is self-aligning when the protrusion is engaging the opening of the tube received in the forming station.

4. A method according to claim 1, comprising heating an upper section of the movable frame to a first temperature and heating a lower-section of the movable frame to a second temperature with the forming station between the upper section and the lower section the second temperature is lower than the first temperature.

5. A method according to claim 1, comprising providing the distal end of the forming member with a rounded shoulder transition with a curvature radius between about 0.2-0.6 mm at the foot of the distal end and with a protrusion extending from said shoulder transition region which is inserted into the opening of the tube, and providing the protrusion is provided with a form fitting the opening in the tube, and forming the rounded shoulder with a three-dimensional contour congruent with the curvature of the opening in the cylindrical surface of the tube.

6. A method according to claim 1, comprising providing the tube made of a medical grade polymer having a Shore A value in the range of about 64 to about 100, and heating the forming member to a temperature above the softening point of the polymer of the tube and below the melting point of said polymer.

21. The method of claim 1 wherein the predetermined holding time is about 1 to 5 seconds.

7. An apparatus for manipulating openings in a polymer tube for manufacturing a catheter, said apparatus comprising:

a forming member, having a distal end adapted for engagement with an opening punched in the tube provided adjacent said distal end, wherein said distal end of the forming member is provided with a rounded shoulder transition portion at a foot of the distal end and with a protrusion extending from said shoulder transition portion, said protrusion having a form fitting the opening in the tube, said opening punched in the tube being provided with a three-dimensional edge contour, whereby central, straight sections of the edge contour of the opening are lower than the outer contour of the tube, when the tube is viewed from the side, and end sections of the edge contour of the opening curve outwards towards the straight outer contour of the tube itself, and

heating means to heat said forming member to a temperature above the softening point of the polymer of the tube,

said distal end of the forming member has a contour shaped to correspond to the three-dimensional contour of the edge of the punched opening in the tube, wherein substantially straight sections of the contour of the a shoulder transition portion of the forming member extend substantially in the same plane, and end sections of the contour of the shoulder transition portion curve out of said plane.

8. An apparatus according to claim 7, wherein said apparatus comprises a movable frame comprising one or more forming stations, each forming station being adapted for receiving a flexible polymer tube with at least one opening therein through the station and each forming station comprising a forming member that is mounted in floating arrangement in said forming station.

9. An apparatus according to claim 7, wherein the forming member is self-aligning when the protrusion is engaging the opening of the tube.

10. An apparatus according to claim 7, wherein the movable frame comprises an upper section and a lower section where between the at least one forming station is arranged.

11. An apparatus according to claim 7, wherein the forming member is made of metal.

13. An apparatus according to claim 7, wherein the rounded shoulder portion is provided with a curvature radius between about 0.2-0.6 mm.

14. An apparatus according to claim 7, wherein the protrusion is elongated with a longitudinal length substantially corresponding to the axial extension of the opening on the tube.

15. An apparatus according to claim 7, wherein the tube is made of a medical grade polymer, comprising a thermoplastic material.

22. The apparatus of claim 15 wherein the thermoplastic material comprises a polyester-type thermoplastic polyurethane (TPU) compound having a Shore A value in the range of about 80 to 100, polyvinylchloride (PVC), or polyurethane (PUR).

12. (canceled)

16. (canceled)

17. A catheter for medical purposes, such as for insertion into a body opening for draining fluids, the catheter comprising:

a flexible tube having a distal end region wherein the tube is provided with at least one draining opening, a peripheral edge on an outside of the tube is provided with a curvature for creating a smooth transition between an exterior surface of the tube and a substantially radially oriented cut constituting an opening side and wherein said curvature is a rounded edge with a curvature radius between 0.2-0.6 mm, and said rounded edge is formed in a curved plane following the curvature of the opening in a cylindrical surface of the tube, and wherein the tube is made of a medical grade polymer having a Shore A value in the range of about 64 to about 100.

18. A catheter according to claim 17, wherein the opening is elongated with a longitudinal length substantially corresponding to the diameter of the tube.

19. A catheter according to claim 17, wherein the polymer is a thermoplastic material comprising a polyester-type thermoplastic polyurethane (TPU) compound, polyvinylchloride (PVC), having a Shore A hardness ranging from about 64 to 85, or polyurethane (PUR).

20. A catheter according to claim 17, wherein the angle between the opening side and the internal surface of the tube is within the range of about 64-90°

.