Valved Catheters Including High Flow Rate Catheters

Abstract

A pressure activated two-way slit valve assembly is designed to be used in combination with, but not limited to, a high flow rate catheter to prevent accidental ingestion of air or loss of blood if the closure cap comes off during non-use of the catheter. In addition, the potential for occlusion of the esthete due to blood clots in the catheter and catheter related infection is substantially reduced. The pressure activated two-way slit valve assembly includes a first end, a second end, a wall defining a dumbbell shaped channel, and a flexible, this disk having a slit and positioned within the pressure activated two-way slit valve assembly to reside within the dumbbell shaped channel. The slit and the dumbbell shaped channel are sized to enable the slit to deform in response to a predetermined pressure differential across the slit to allow fluid to pass therethrough.

What is claimed is: 
     
         1 . A method of transferring fluid to or from a patient, the method comprising:
 accessing an anatomical lumen within the patient;   placing a catheter with a pressure activated slit valve assembly, the assembly comprising:
 a housing defining a lumen therethrough, the lumen having a longitudinal axis; and 
 a membrane disposed across the lumen, said membrane having a slit therethrough; 
 wherein the lumen has a substantially dumbbell shaped cross-section, the cross-section lying in a plane perpendicular to the longitudinal axis; and 
   transferring fluid to or from the patient through the catheter.   
     
     
         2 . The method of  claim 1 , wherein the slit deforms to permit fluid flow when exposed to a fluid pressure differential of at least a predetermined threshold. 
     
     
         3 . The method of  claim 1 , wherein the dumbbell shaped cross-section is defined by two flanking regions and a central region, the central region being of a lesser cross-sectional area than the flanking regions. 
     
     
         4 . The method of  claim 3 , wherein the cross-sectional areas of the flanking regions and central region allow flow rates of up to 500 ml/min. 
     
     
         5 . The method of  claim 1 , wherein the housing tapers away in either direction from the membrane. 
     
     
         6 . The method of  claim 1 , wherein the housing has a substantially elliptical outer cross-section. 
     
     
         7 . The method of  claim 1 , wherein the membrane has a substantially elliptical outer cross-section. 
     
     
         8 . The method of  claim 1 , wherein the slit of the membrane is straight. 
     
     
         9 . The method of  claim 1 , wherein the slit of the membrane is not straight.