Cannular Device and Method of Manufacture

Abstract

A cannula comprising a polymeric material which is phthalate-free, yet retains flexibility, workability and elongation properties so as to avoid kinking when bent. Also disclosed is a method of manufacturing a cannular device comprising extruding a flexible, biocompatible, phthalate-free polymeric composition through a round die into a tube, pulling the tube through a water bath at a rate established according to a predetermined function, and cutting the tube to for a cannular device, wherein the predetermined function periodically modulates a pulling rate.

1 - 22 . (canceled) 
     
     
         23 . A method of manufacturing a cannular device, comprising:
 extruding a flexible, biocompatible, phthalate-free polymeric composition through a round die into a tube;   pulling the tube through a water bath at a rate established according to a predetermined function; and   cutting the tube to form a cannular device;   wherein the predetermined function periodically modulates a pulling rate.   
     
     
         24 . The method of  claim 23 , wherein the predetermined function provides periods in which the pulling rate increases from a minimal pulling rate to a maximal pulling and periods in which the pulling rate decreases from a maximal pulling rate to a minimal pulling rate so that the tube is formed having an oscillating cross-sectional diameter that changes with time. 
     
     
         25 . The method of  claim 24 , wherein the predetermined function further provides periods in which the pulling rate is not modulated. 
     
     
         26 . The method of  claim 25 , wherein the predetermined function further provides that the periods in which the pulling rate is not modulated are interposed between periods in which the pulling rate is modulated. 
     
     
         27 . The method of  claim 25 , wherein the cut tube is adapted to resist kinking when tested according to an 180° bend test. 
     
     
         28 . The method of  claim 25 , wherein the polymeric composition is free of plasticizers. 
     
     
         29 . The method of  claim 25 , wherein the polymeric composition comprises a thermoplastic elastomer. 
     
     
         30 . The method of  claim 29 , wherein the thermoplastic elastomer has a Shore A hardness in a range from about 45 to about 85. 
     
     
         31 . The method of  claim 25 , wherein the tube is adapted for recovering to full patency to cause the inner lumen to remain free from obstruction after being clamped to complete closure. 
     
     
         32 . The method of  claim 25 , wherein the cut tube has a circular cross-section defining an inner diameter and an outer diameter, the circular cross-section diminishing in size along a length from a first inner diameter and a first outer diameter to a second inner diameter and a second outer diameter, the first inner diameter being larger than the second inner diameter and the first outer diameter being larger than the second outer diameter. 
     
     
         33 . The method of  claim 25 , wherein the cut tube has a proximal end and a distal end, the proximal end having a first inner diameter and a first outer diameter defining a first thickness, the distal end having a second inner diameter and a second outer diameter defining a second thickness, wherein the second thickness is about 50 to about 95% of the first thickness. 
     
     
         34 . The method of  claim 25 , wherein the tube is sufficiently clear so that fluids passing through the tube can be observed. 
     
     
         35 . The method of  claim 25 , wherein the cut tube has a proximal end and a distal end, wherein the cut tube is tapered from the proximal end to the distal end. 
     
     
         36 . A method of manufacturing a cannular device, comprising:
 extruding a flexible, biocompatible, phthalate-free polymeric composition through a round die into a tube;   pulling the tube through a water bath at a rate established according to a predetermined function; and   cutting the tube to form a cannular device;   wherein the predetermined function provides periods in which the pulling rate increases from a minimal pulling rate to a maximal pulling and periods in which the pulling rate decreases from a maximal pulling rate to a minimal pulling rate so that the tube is formed having an oscillating cross-sectional diameter that changes with time;   wherein the cut tube has a proximal end and a distal end, the proximal end having a first inner diameter and a first outer diameter defining a first thickness, the distal end having a second inner diameter and a second outer diameter defining a second thickness, wherein the second thickness is about 50 to about 95% of the first thickness.   
     
     
         36 . A method of manufacturing a cannular device, comprising:
 extruding a flexible, biocompatible, phthalate-free polymeric composition through a round die into a tube;   pulling the tube through a water bath at a rate established according to a predetermined function; and   cutting the tube to form a cannular device;   wherein the tube is adapted to resist kinking and to recover to full patency after being clamped to complete closure.