Fluid Bypass Device for Valved Catheters

Abstract

Bypass elements for medical valves and methods of using the same are disclosed. Embodiments of the invention include an insert having a tip that is adapted to displace a valve element without penetrating it, and a lumen that fluidly communicates with a lumen of a valve housing distal to the valve element when the bypass element is engaged. Bypass elements are used, in certain embodiments, to facilitate fluid pressure and ECG signal measurements through implanted medical devices including catheters.

What is claimed is: 
     
         1 . A bypass element for a valve, comprising:
 an insert tip configured to displace one or more edges of a slit in a membrane of a valve without penetrating said membrane;   an insert connector adapted to connect to a measurement device; and   an insert lumen extending between the insert tip and the insert connector, said insert lumen permitting fluid flow between the tip and the connector.   
     
     
         2 . The bypass element of  claim 1 , wherein the insert tip has an external diameter sized to fit within a lumen of a valve. 
     
     
         3 . The bypass element of  claim 1 , further comprising:
 a proximal insert portion including the connector;   a distal insert portion including the tip;   a junction between said proximal and distal insert portions; and   a compressible element disposed about the circumference of the insert at the junction and configured to permit the insert to compress longitudinally.   
     
     
         4 . The bypass element of  claim 3  wherein the proximal and distal insert portions can be rotated relative to one another. 
     
     
         5 . The bypass element of  claim 3 , further comprising a sealing member disposed at the junction of the proximal and distal insert portions. 
     
     
         6 . A system for bypassing a valved vascular access catheter, comprising:
 a vascular catheter insertable into a patient;   a valve housing in fluid communication with the catheter, the valve housing comprising:
 a valve lumen and a flexible membrane with a slit therethrough, the membrane being disposed within the valve lumen and the slit remaining closed when a pressure differential thereacross remains below a predetermined threshold; and 
   an insert, comprising:
 a proximal connector engageable with the catheter; 
 a distal insert tip sized to fit within the valve lumen the valve housing and to open the slit; and 
 an insert lumen extending from the proximal connector to the distal insert tip, the insert lumen configured to permit fluid communication between the proximal connector and the distal tip. 
   
     
     
         7 . The system of  claim 6 , wherein the insert further comprises:
 a proximal insert portion including the proximal connector;   a distal insert portion including the distal insert tip;   a junction between said proximal and distal insert portions; and   a compressible element disposed about the circumference of the insert at the junction and configured to permit the insert to compress about a longitudinal axis when the insert is engaged with a valve membrane.   
     
     
         8 . The system of  claim 6 , wherein the proximal and distal insert portions can be rotated relative to one another at the junction. 
     
     
         9 . The system of  claim 6 , further comprising a sealing member disposed at the junction of the proximal and distal housings. 
     
     
         10 . A method of measuring a physical characteristic in a patient having a catheter with a pressure activated valve, the pressure activated valve comprising a membrane having at least one slit therethrough, the slit opening in response to a fluid pressure in excess of a predetermined threshold, the method comprising the steps of:
 providing a an insert, comprising:
 a proximal connector engageable with the catheter; 
 a distal insert tip sized to fit within a lumen of the pressure activated valve and open the at least one slit in the membrane without penetrating the at least one slit; and 
 an insert lumen extending from the proximal connector to the distal insert tip, the insert lumen configured to permit fluid communication between the proximal connector and the distal tip; 
   placing the insert into the valve housing and contacting the membrane, thereby permitting fluid transmission between the catheter and the insert lumen;   measuring the physical characteristic through the insert lumen.   
     
     
         11 . The method of  claim 10 , wherein the physical characteristic is selected from the group consisting of a pressure wave, acoustic wave and ECG wave. 
     
     
         12 . The method of  claim 10 , further comprising the step of determining a position of a distal tip of the catheter based on a measured fluid pressure. 
     
     
         13 . The method of  claim 12 , further comprising the step of repositioning the distal tip of the catheter. 
     
     
         14 . The method of  claim 12 , further comprising the step of positioning the distal tip of the catheter in an optimal position. 
     
     
         15 . The method of  claim 10 , further comprising the step of determining a position of a distal tip of the catheter based on a measured ECG wave. 
     
     
         16 . The method of  claim 12 , further comprising the step of repositioning the distal tip of the catheter. 
     
     
         17 . The method of  claim 12 , further comprising the step of positioning the distal tip of the catheter in an optimal position.