Systems and methods for flushing catheters

Abstract

Various improvements are made to catheters adapted to be flushed to remove air from within the catheter. For example, improved catheters include a catheter with a self-sealing seal at its distal end to pass a venting tube for removing air from within the catheter, a catheter having a distal end whose diameter is reduced to compress a seal adapted to pass a venting tube; a catheter having a cap at its distal end where the cap has a venting hole that is opened or closed depending on the conditions subjected to the shape-memory material of the cap; a catheter having a vent hole at its distal end; a catheter having an opening at its distal end that can be closed by a plug; and a catheter having a narrow neck with an opening to vent air and the neck is coupled to a tab where twisting the tab closes the opening in the neck.

What is claimed is:  
     
         1 . A catheter, comprising: 
 a catheter body having a lumen with a distal end;    a seal adapted to seal the distal end of the lumen; and    a tube extending through the seal, the tube providing an opening between the lumen and the outside;    wherein the seal is adapted to seal itself when the tube is pulled out of the seal.    
     
     
         2 . The catheter of  claim 1 , wherein the seal comprises a shape-memory material.  
     
     
         3 . The catheter of  claim 2 , wherein the seal comprises Pebax 35D.  
     
     
         4 . The catheter of  claim 2 , wherein the seal comprises silicone.  
     
     
         5 . The catheter of  claim 1 , wherein the tube has a distal portion extending out from the catheter body.  
     
     
         6 . The catheter of  claim 5 , further comprising a pull tab attached to the distal portion of the tube.  
     
     
         7 . The catheter of  claim 6 , wherein the tube has a distal tip, the pull tab has a notch, and the distal tip of the tube terminates at the notch.  
     
     
         8 . The catheter of  claim 6 , wherein the distal portion of the tube has a zigzag shape that is encased in the pull tab.  
     
     
         9 . The catheter of  claim 6 , wherein the pull tab comprises plastic or metal.  
     
     
         10 . The catheter of  claim 5 , wherein the outer surface of the distal portion of the tube is roughened.  
     
     
         11 . The catheter of  claim 5 , wherein the tube comprises stainless steel.  
     
     
         12 . The catheter of  claim 5 , wherein the tube comprises plastic.  
     
     
         13 . The catheter of  claim 1 , wherein the catheter body includes a main portion, a distal portion having a smaller diameter than the main portion, and a tapered portion that tapers downward from the main portion to the distal portion of the catheter body.  
     
     
         14 . The catheter of  claim 13 , wherein the seal extends along the distal portion of the catheter body.  
     
     
         15 . The catheter of  claim 1 , further comprising a medical device within the catheter lumen.  
     
     
         16 . The catheter of  claim 15 , wherein the medical device is an imaging device.  
     
     
         17 . The catheter of  claim 16 , wherein the imaging device includes an ultrasound transducer.  
     
     
         18 . The catheter of  claim 16 , wherein the imaging device is a light imaging device.  
     
     
         19 . The catheter of  claim 1 , further comprising a treatment device within the catheter lumen.  
     
     
         20 . A method of fabricating a catheter, comprising: 
 providing an elongated catheter body having a lumen;    providing a seal;    placing a tube through the seal;    inserting the seal with the tube into a distal end of the catheter lumen; and    compressing and heating a portion of the catheter body surrounding the seal to firmly fit the seal in the catheter lumen.    
     
     
         21 . The method of  claim 20 , wherein the step of compressing and heating the catheter body further comprises: 
 positioning a heat shrink sleeve around the catheter body and seal; and    applying heat to the heat shrink.    
     
     
         22 . The method of  claim 20 , wherein the seal comprises a shape-memory material.  
     
     
         23 . The method of  claim 20 , wherein the seal comprises Pebax 35D.  
     
     
         24 . The method of  claim 20 , wherein the seal comprises silicone.  
     
     
         25 . The method of  claim 20 , further comprising attaching a pull tab to a portion of the tube.  
     
     
         26 . The method of  claim 20 , further comprising roughening a portion of the outer surface of the tube.  
     
     
         27 . The method of  claim 20 , further comprising providing a medical device within the catheter lumen.  
     
     
         28 . The method of  claim 27 , wherein the medical device is an imaging device.  
     
     
         29 . The method of  claim 28 , wherein the imaging device includes an ultrasound transducer.  
     
     
         30 . The method of  claim 28 , wherein the imaging device is a light imaging device.  
     
     
         31 . The method of  claim 20 , further comprising providing a treatment device within the catheter lumen.  
     
     
         32 . A method of flushing a catheter, the catheter including a catheter body having a lumen, a self-sealing seal adapted to seal a distal end of the lumen, and a tube extending through the seal, the method comprising: 
 flushing a solution into the catheter lumen from a proximal end of the lumen; and    subsequently pulling the tube out of the seal.    
     
     
         33 . The method of  claim 32 , wherein the step of flushing the solution into the catheter lumen further comprising injecting the solution into the lumen.  
     
     
         34 . The method of  claim 32 , wherein the tube is pulled out of the seal by gripping a pull tab attached to the tube.  
     
     
         35 . The method of  claim 32 , wherein the tube is pulled out of the seal by gripping the tube with a gripping instrument.  
     
     
         36 . The method of  claim 32 , further comprising providing a medical device within the catheter lumen.  
     
     
         37 . The method of  claim 36 , wherein the medical device is an acoustic or light imaging device.  
     
     
         38 . The method of  claim 32 , further comprising providing a treatment device within the catheter lumen.  
     
     
         39 . A catheter, comprising: 
 a catheter body having a lumen with a distal portion and an exit hole to the lumen; and    a tube within the lumen extending from the distal portion of the lumen to the exit hole, wherein a portion of the tube protrudes out of the catheter body through the exit hole.    
     
     
         40 . The catheter of  claim 39 , wherein the tube comprises polymide.\ 
     
     
         41 . The catheter of  claim 39 , wherein the tube comprises stainless steel or plastic.  
     
     
         42 . The catheter of  claim 39 , wherein the tube has an inlet within the distal potion of the catheter lumen, an outlet located outside of the catheter body, and a lumen coupling the inlet to the outlet.  
     
     
         43 . The catheter of  claim 39 , further comprising a medical device within the catheter lumen.  
     
     
         44 . The catheter of  claim 43 , wherein the medical device is an imaging device.  
     
     
         45 . The catheter of  claim 44 , wherein the imaging device includes an ultrasound transducer.  
     
     
         46 . The catheter of  claim 44 , wherein the imaging device is a light imaging device.  
     
     
         47 . The catheter of  claim 39 , further comprising a treatment device within the catheter lumen.  
     
     
         48 . A method of flushing a catheter, the catheter including a catheter body having a lumen and an exit hole to the lumen, and a tube within the lumen extending from a distal portion of the lumen to the exit hole, the method comprising: 
 flushing a solution into the catheter lumen from a proximal end of the lumen, wherein the solution flows to the distal portion of the lumen and into the tube from the distal portion of the lumen; and    subsequently pulling the tube out of the catheter lumen through the exit hole.    
     
     
         49 . The method of  claim 48 , wherein the tube comprises polymide.  
     
     
         50 . The method of  claim 48 , wherein the tube comprises stainless steel or plastic.  
     
     
         51 . The method of  claim 48 , wherein there is a medical device within the catheter lumen alongside the tube.  
     
     
         52 . The method of  claim 51 , wherein the medical device includes an acoustic or light imaging device.  
     
     
         53 . The method of  claim 51 , wherein the medical device is a treatment device.  
     
     
         54 . A catheter, comprising: 
 a catheter body having a lumen with a distal end; and    a cap enclosing the distal end of the lumen, wherein the cap has a vent hole that seals itself when a stimulus is applied to the cap.    
     
     
         55 . The catheter of  claim 54 , wherein the stimulus is heat.  
     
     
         56 . The catheter of  claim 54 , wherein the stimulus is moisture.  
     
     
         57 . The catheter of  claim 54 , wherein the stimulus is pressure.  
     
     
         58 . A method of fabricating a catheter, comprising: 
 providing a cap made of a shape-memory material that can be mechanically deformed into a deformed shape and maintains its deformed shape until a stimulus is applied thereon;    providing a elongated catheter body having a lumen;    increasing the diameter of the cap outwardly;    forming a vent hole through the cap; and    attaching the cap to the catheter body so that the cap encloses a distal end of the catheter lumen.    
     
     
         59 . The method of  claim 58 , wherein the stimulus is heat.  
     
     
         60 . The method of  claim 58 , wherein the stimulus is moisture.  
     
     
         61 . The method of  claim 58 , wherein the stimulus is pressure.  
     
     
         62 . A catheter, comprising: 
 a catheter body having a lumen and a vent hole to the lumen, wherein the diameter of the lumen is dimensioned so that flushing solution can not pass through the vent hole.    
     
     
         63 . The catheter of  claim 62 , wherein the diameter of the vent hole is approximately 0.00005-0.001 inches.  
     
     
         64 . The catheter of  claim 62 , wherein the vent hole is located at a distal end of the lumen.  
     
     
         65 . The catheter of  claim 64 , wherein the diameter of the vent hole is approximately 0.00005 inches.  
     
     
         66 . A method of flushing a catheter, the catheter including a catheter body having a lumen with an opening at a distal end thereof, the method comprising: 
 flushing a solution into the catheter lumen from a proximal end of the lumen, wherein the solution flows to the opening of the lumen; and    subsequently sealing the opening of the lumen with a plug.    
     
     
         67 . The method of  claim 66 , wherein the plug comprises an elastic material.  
     
     
         68 . The method of  claim 66 , wherein the plug comprises an expanding material that expands upon contact with the flushing solution.  
     
     
         69 . A catheter, comprising: 
 a catheter body having a lumen with a distal end; and    a neck attached to the catheter body, the neck being narrower than the catheter body and having an opening to the distal end of the catheter lumen; and    a tab attached to the neck.    
     
     
         70 . The catheter of  claim 69 , wherein the neck and the tab are integrally formed.  
     
     
         71 . A method of flushing a catheter, a catheter including a catheter body having a lumen with a distal end, and a neck attached to the catheter body, the neck having an opening to the distal end of the catheter lumen, the method comprising: 
 flushing a solution into the catheter lumen from a proximal end of the lumen; and    subsequently twisting the neck to close off the opening to the catheter lumen.    
     
     
         72 . The method of  claim 71 , wherein a tab is attached to the neck, and the step of twisting the neck comprises twisting the tab.