Stylet-free epidural catheter and thread assist device

Abstract

A stylet-free epidural catheter for insertion into a patient via a needle defining proximally a needle hub and distally a needle tip, includes a catheter having a proximal end, a distal end, and a body connecting the ends. The body defines therealong a stiffening section of a predetermined length disposed a predetermined distance proximally of the distal end such that it is located generally about an area where the body approaches a needle hub when the distal end approaches a needle tip. The stiffening section has a flexural stiffness at least twice that of the remainder of the body. A thread assist device to reduce buckling of a catheter being inserted through a needle, includes a body defining a TAD proximal end, a TAD distal end substantially spaced apart along a longitudinal axis from the TAD proximal end, and a TAD sidewall connecting the TAD ends. The TAD distal end is configured and dimensional for at least partial receipt and releasable maintenance within a hub of a needle, and the TAD sidewall is configured and dimensioned intermediate the TAD ends to enable axial sliding manipulation of the catheter through the needle hub by a user. The TAD ends substantially preclude non-axial movement of the catheter at the TAD ends and the TAD sidewall limits non-axial movement of the catheter between the TAD ends.

I claim:  
     
         1 . A stylet-free catheter for insertion into a patient via a needle defining proximally a needle hub and distally a needle tip, comprising: 
 a catheter having a proximal end, a distal end, and a body connecting said proximal and distal ends;    said body defining therealong a stiffening section of a predetermined length disposed a predetermined distance proximally of said distal end such that it is located generally about an area where said body approaches a needle hub when said distal end approaches a needle tip;    said stiffening section having a flexural stiffness at least twice that of the remainder of said body.    
     
     
         2 . The catheter of  claim 1  wherein said stiffening section has a length of about 5 cm.  
     
     
         3 . The catheter of  claim 2  wherein said stiffening section is disposed from about 10 cm to about 15 cm proximally of said distal end.  
     
     
         4 . The catheter of  claim 1  wherein said stiffening section extends from about 10 cm to about 15 cm proximally of said distal end.  
     
     
         5 . The catheter of  claim 1  wherein said stiffening section has a diameter not exceeding the diameter of the remainder of said body by more than about 0.15 mm.  
     
     
         6 . The catheter of  claim 1  wherein said stiffening section is formed of plastic tubing and a cured adhesive extending circumferentially about said plastic tubing to provide a stiffening coating.  
     
     
         7 . The catheter of  claim 6  wherein said stiffening coating is non-tacky and wear-resistant.  
     
     
         8 . The catheter of  claim 6  wherein said stiffening coating has a thickness not exceeding about 0.08 mm.  
     
     
         9 . The catheter of  claim 6  wherein said stiffening coating extends in a substantially uniform thickness along said stiffening section and about said plastic tubing.  
     
     
         10 . The catheter of  claim 6  wherein said stiffening coating reinforces said plastic tubing of said stiffening section.  
     
     
         11 . The catheter of  claim 6  wherein said cured adhesive is UV-cured.  
     
     
         12 . The catheter of  claim 11  wherein said cured adhesive is cured in situ.  
     
     
         13 . The catheter of  claim 6  wherein said cured adhesive is UV-cured in situ.  
     
     
         14 . The catheter of  claim 1  wherein said stiffening section is formed of plastic tubing and a plastic sleeve heat-shrunk about said plastic tubing to stiffen said plastic tubing.  
     
     
         15 . The catheter of  claim 14  wherein said sleeve is non-tacky and wear-resistant.  
     
     
         16 . The catheter of  claim 14  wherein said sleeve has a thickness not exceeding 0.008 cm.  
     
     
         17 . The catheter of  claim 14  wherein said sleeve extends in a substantially uniform thickness along said stiffening section and about said plastic tubing.  
     
     
         18 . The catheter of  claim 14  wherein said sleeve reinforces said plastic tubing of said stiffening section.  
     
     
         19 . The catheter of  claim 14  wherein said sleeve is polyethylene terephthalate (PET).  
     
     
         20 . A catheter for insertion into a patient via a needle defining proximally a needle hub and distally a needle tip, comprising: 
 a catheter having a proximal end, a distal end, and a body section connecting said proximal and distal ends;    said body defining therealong a stiffening section having a length of about 5 cm. and a diameter not exceeding the diameter of the remainder of said catheter body by more than about 0.15 mm;    said stiffening section being disposed from about 10 cm to about 15 cm. proximally of said distal end such that it is located generally about an area where said body approaches a needle hub when said distal end approaches a needle tip;    said stiffening section being formed of plastic tubing and an adhesive UV-cured in situ and extending circumferentially about said plastic tubing to provide a stiffening coating, said stiffening coating being non-tacky and wear-resistant and extending in a substantially uniform thickness not exceeding 0.08 mm along said stiffening section and about said plastic tubing to reinforce said stiffening section;    said stiffening section having a flexural strength at least twice times that of the remainder of said body.    
     
     
         21 . A catheter for insertion into a patient via a needle defining proximally a needle hub and distally a needle tip, comprising: 
 a catheter having a proximal end, a distal end, and a body section connecting said proximal and distal ends;    said body defining therealong a stiffening section having a length of about 7 cm. and a diameter not exceeding the diameter of the remainder of said catheter body by more than about 0.15 mm;    said stiffening section being disposed from about 10 cm to about 15 cm. proximally of said distal end such that it is located generally about an area where said body approaches a needle hub when said distal end approaches a needle tip;    said stiffening section being formed of plastic tubing and a plastic sleeve heat-shrunk about said plastic tubing to stiffen said plastic tubing;    said sleeve being non-tacky and wear-resistant and extending in a substantially uniform thickness not exceeding about 0.08 mm along said stiffening section and about said plastic tubing to reinforce said stiffening section;    said stiffening section having a flexural strength at least twice that of the remainder of said body.    
     
     
         22 . In combination, the catheter of  claim 1  and a needle defining proximally a needle hub and distally a needle tip.  
     
     
         23 . In combination, the catheter of  claim 21  and a needle defining proximally a needle hub and distally a needle tip.  
     
     
         24 . In combination, the catheter of  claim 22  and a needle defining proximally a needle hub and distally a needle tip.