Abstract:
A medical clamping assembly includes a housing defining a chamber and a deflecting member operable to slide relative to the housing between a first position and a second position. A conduit is also provided within the housing and is adapted for fluid coupling to a medical device. The medical clamping assembly also includes a biasing element disposed within the housing adjacent to the conduit. The deflecting member is movable relative to the housing between the first position corresponding to an open state of the conduit and the second position corresponding to a closed state of the conduit whereby the biasing element compresses the conduit to substantially close a lumen of the conduit.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to U.S. Provisional Application Ser. No. 61/171,659, filed Apr. 22, 2009, entitled “BIASED CLAMPING ASSEMBLIES”, the contents of which are hereby incorporated by reference in their entirety. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates generally to clamping assemblies for flexible fluid conduits, and, in particular, to a clamping assembly for obstructing fluid flow through extension conduits of catheter assemblies. 
     2. Description of the Related Art 
     Catheters are flexible medical devices which facilitate the withdrawal and introduction of fluids from and to body cavities, ducts, and vessels. Catheter assemblies may have particular application in a hemodialysis procedure where blood is withdrawn from a blood vessel for treatment, and subsequently returned to the blood vessel for circulation. Known hemodialysis catheters include multiple lumens, such as dual lumen or triple-lumen catheters, which permit bi-directional fluid flow within the catheter whereby one lumen is dedicated for withdrawal of blood from a body vessel and the other lumen is dedicated for returning the treated blood to the vessel. During an exemplary hemodialysis procedure, a multiple lumen catheter is inserted into a body and blood is withdrawn through an arterial lumen of the catheter. The removed blood is directed to a hemodialysis unit which dialyzes, or purifies, the blood to remove waste and toxins from the blood. The dialyzed blood is returned to the patient through a venous lumen of the catheter. 
     Various techniques and apparatus are employed for the insertion of hemodialysis catheters including, e.g., guidewires, introduction stylets or the like. Some of these known techniques include subcutaneous tunneling methodologies where a subcutaneous tunnel is formed between two spaced openings in the skin with the use of a trocar or the like. One catheter end is introduced through an entry site or venotomy site for routing into, e.g., the jugular vein and routed to the heart. The trailing or proximal end is advanced through the subcutaneous tissue to exit a second exit opening adjacent the sternum of the patient beneath the venotomy site. Once the proximal end of the catheter is exposed, a catheter hub with extension conduits is fluidly connected to the catheter. One subcutaneous technique is disclosed in U.S. Pat. No. 5,509,897 to Twardowski et al., the contents of which are incorporated herein by reference in its entirety. 
     SUMMARY 
     The present disclosure relates to a medical clamping assembly for use with a catheter including a housing that defines a chamber. The assembly includes a deflecting member that slides relative to the housing between a first position of the housing and a second position of the housing. The clamping assembly also includes a conduit within the housing adapted for fluid coupling to the catheter and a biasing element disposed within the housing adjacent to the conduit. The deflecting member moves between the first position of the housing corresponding to an open state of the conduit and the second position of the housing corresponding to a closed state where the biasing element compresses the conduit to substantially close a lumen of the conduit. The housing further includes a track having a notch at the first position of the housing. The deflecting member slides in the track and is held in place at the first position of the housing by the notch. The biasing element is a metal spring member that is formed from stainless steel having a grade 301, 302, or 304 or a shape memory alloy such as nitinol. The clamping assembly also includes a cradle coupled to the deflecting member. The biasing element rests on the cradle so that when the deflecting member is at the first position of the housing, the cradle prevents the biasing element from compressing the conduit. The biasing element is in a normally closed state and biases the deflecting member toward the second position of the housing. The medical clamping assembly has an adaptor at a distal end of the housing that is operatively connected to the catheter and includes a luer connector. The medical clamping assembly has another adaptor with a luer connector at a proximal end of the housing that secures the biasing element in the housing and is operatively connected to an extension conduit fluidly coupled to a dialysis unit. 
     The present disclosure also relates to a medical clamping assembly for use with a catheter including a housing that defines a chamber. The assembly includes a deflecting member that slides relative to the housing between a first position of the housing and a second position of the housing. The clamping assembly also includes a biasing element disposed within the housing adjacent to the conduit. The deflecting member moves between the first position of the housing corresponding to an open state and the second position of the housing corresponding to a closed state where the biasing element compresses a conduit extending through the medical clamping assembly to substantially close a lumen of the conduit. A first end of the conduit is fluidly coupled to the catheter and a second end of the conduit is fluidly coupled to a dialysis unit and the medical clamping assembly is movable relative to the conduit. 
     The present disclosure also relates to a catheter assembly. The catheter assembly includes a catheter, a dialysis conduit, and a clamping assembly operatively connected in between the catheter and the dialysis conduit. The clamping assembly has a housing defining a chamber, a deflecting member operable to slide along the housing between a first position and a second position, a conduit extending through the housing and being adapted for fluid coupling to the catheter and the dialysis unit, and a biasing element disposed within the housing adjacent to the conduit. The deflecting member being movable relative to the housing between the first position corresponding to an open state of the conduit and the second position corresponding to a closed position of the conduit whereby the biasing element compresses the conduit to substantially close a lumen of the conduit. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Various embodiments of the presently disclosed catheter clamping system are described herein with references to the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of a catheter assembly with a clamping assembly according to an embodiment of the present disclosure; 
         FIG. 2  is a side view of a catheter assembly with a clamping assembly in an open condition according to an embodiment of the present disclosure; 
         FIG. 3  is a cross-sectional view of the catheter assembly shown in  FIG. 2  taken along the lines  3 - 3 ; 
         FIG. 4  is a cross-sectional view of the catheter assembly shown in  FIG. 3  taken along the line  4 - 4 ; 
         FIG. 5  is a side view of the catheter assembly with a clamping assembly in a closed condition according to an embodiment of the present disclosure; 
         FIG. 6  is a cross-sectional view of the catheter assembly shown in  FIG. 5  taken along the lines  6 - 6 ; 
         FIG. 7  is a side view of a catheter assembly with a clamping assembly according to another embodiment of the present disclosure; 
         FIG. 8  is a cross-sectional view of the catheter assembly shown in  FIG. 7  taken along the lines  8 - 8 ; 
         FIG. 9  is a perspective view of a catheter assembly with a clamping assembly according to another embodiment of the present disclosure; 
         FIG. 10  is a side view of a catheter assembly with a clamping assembly according to another embodiment of the present disclosure; 
         FIG. 11  is a cross-sectional view of the catheter assembly shown in  FIG. 10  taken along the lines  11 - 11 ; 
         FIG. 12  is a side view of a catheter assembly with a clamping assembly according to another embodiment of the present disclosure; and 
         FIG. 13  is a cross-sectional view of the catheter assembly shown in  FIG. 12  taken along the lines  13 - 13 . 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, embodiments of the presently disclosed catheter assemblies will be described with reference to the accompanying drawings. Like reference numerals refer to similar or identical elements throughout the description of the figures. In the discussion that follows, the term “proximal” or “trailing” will refer to the portion of a structure that is closer to a clinician or dialysis system, while the term “distal” or “leading” will refer to the portion of the structure that is farther from the clinician or dialysis system. As used herein, the term “subject” refers to a human patient or other animal. The term “clinician” refers to a doctor, nurse or other care provider and may include support personnel. 
     The presently disclosed catheter clamping assemblies is employed with dialysis systems, but is also suitable for other devices that use clamping assemblies to open and close conduits or tubes. A catheter assembly according to an embodiment of the present disclosure, such as catheter assembly  100  shown in  FIG. 1 , includes a catheter  102 , a hub or housing  104  and extension conduits  106 . The hub  104  fluidly interconnects catheter  102  and extension conduits  106 . Extension conduits  106  are formed from standard silicone tubes. Catheter assembly  100  additionally includes a pair of clamping assemblies  200  operatively associated with each extension conduit  106 . Each clamping assembly  200  is configured to compress an extension conduit  106 , thereby obstructing or at least hindering fluid flow through the extension conduit  106 . In this embodiment, adjacent to the proximal end of each clamping assembly  200  is a proximal extension or dialysis conduit  108  that is connected directly or indirectly to a dialysis system  150  (as shown schematically in  FIG. 1 ). 
     Referring to  FIG. 2 , a clamping assembly shown generally as  200 , has a housing  202  having a distal portion  201  and a proximal portion  208  that fit over extension conduit  106  and position the clamping assembly  200  about the extension conduit  106 . In one embodiment, clamping assembly  200  slides and rotates relative to extension conduit  106  or is secured to extension conduit  106  to prevent relative movement, such as through the use of adhesives, solvent bonding, sonic welding or a press fit between at least one end portion of the housing  202  and the extension conduit  106 . The extension conduit  106  extends from the distal end of the clamping assembly  200  through the distal portion  201  and a chamber defined by housing  202 . Distal portion  201  positions the extension conduit  106  in place and helps prevent the extension conduit  106  from kinking when it enters the chamber defined by housing  202 . Housing  202  has an “L” shaped track  206  in which a deflecting member or sliding tab  204  can slide from a first position near the distal end to a second position near the proximal end of housing  202  along track  206 . Although  FIG. 2  depicts an “L” shaped track in this embodiment, any shaped track having at least one notch or protrusion at either the distal or proximal end (such as “T” or “I” shaped tracks) may be used. Sliding tab  204  defines the valve open or close configuration and drives an internal biasing element that will be discussed hereinbelow. When sliding tab  204  slides to the distal end of track  206  toward notch  207 , sliding tab  204  can be rotated in a clockwise or counterclockwise direction around the housing  202  to lock the sliding tab  204  in place. As shown in  FIG. 2 , the notch  207  is located downward which would require the clinician to rotate the sliding tab  204  downward in the direction of the notch  207  to lock the sliding tab  204  in place. Although not shown, the notch could be located in the upward direction which would require the clinician to rotate the sliding tab  204  upward in the direction of the notch to lock the sliding tab  204  in place. In this embodiment, sliding tab  204  is urged towards proximal portion or leer adaptor  208  of housing  202  (by biasing element  302  as shown in  FIG. 3 ) to bias sliding tab  204  in the proximal direction, towards the closed configuration unless locked in place in notch  207 . Alternatively, sliding tab  204  may be urged in the distal direction towards the open position. 
     In this embodiment, proximal to clamping assembly  200  is an adaptor  212 , which will be described in more detail below with regard to  FIG. 3 , which receives extension conduits  106  and  108 . Adaptor  212  fluidly interconnects extension conduit  106  to extension conduit  108 . A shrink sleeve  218  is provided to seal the extension conduit  108  to adaptor  212  to prevent leakage of fluid as shown in  FIG. 3 . 
     Housing  202  can be labeled or multicolored to indicate a state of the clamp. For instance, proximal end  208  of housing  202  (as shown by the letter “O” in  FIG. 2 ) could be labeled with the word “open”, have a symbol that represents an open state or be colored green to indicate that the clamping assembly  200  is in an open state. The area surrounding notch  207  (as shown by the letter “C” in  FIG. 5 , could be labeled with the word “closed”, have a symbol that represents a closed state or be colored red to indicate that the clamping assembly  200  is in closed state. Alternatively, a variety of colors and/or indicia may be used to identify the state of the clamp. As such, when the clamp is in an open state as shown in  FIG. 2 , the clinician can easily visualize that the clamp is in an open state. If the clamp is in a closed state as will be described below with regard to  FIG. 5 , the clinician can easily visualize that the clamp is in a closed state. 
       FIG. 3  depicts a cross section of the clamping assembly  200  shown in  FIG. 2  taken along the lines  3 - 3 . As shown in  FIG. 3 , clamping assembly  200  has a biasing element  302  that can be deflected without yielding. Biasing element is a metal spring member  302  made from a stainless steel, e.g., a stainless steel having a grade 301, 302, or 304 or a shape memory alloy such as Nitinol. Nitinol is derived from its place of discovery (Nickel Titanium Naval Ordnance Laboratory) and is nickel titanium. The distal end  304  of metal spring member  302  is curved and rests against an inner wall of housing  202 . Due to the curvature of the metal spring member  302  at distal end  304 , the metal spring member  302  slides smoothly along the inner wall of housing  202 . The proximal end  306  of metal spring member  302  is bonded or molded in place in proximal portion  208  of housing  202  to secure the metal spring member  302  to the clamping assembly  200 . Metal spring member  302  is biased to a normally closed position which would pinch or clamp the extension conduit  106 . Metal spring member  302  extends through a cradle  310  connected to slide tab  204  as shown in  FIG. 4 . 
     Adaptor  212  has an annular projection  214  that extends into extension conduit  106 . In this embodiment, annular projection  214  is press fitted into extension conduit  106  or solvent bonded to provide a leak proof seal. Adaptor  212  also has an annular projection  216  that is fluidly connected to extension conduit  108 . As shown in  FIG. 3 , extension conduit fits over annular projection  216 . A shrink sleeve  218  is also provided to seal extension conduit  108  to annular projection  216  to provide a leak proof seal. Adaptor  212  is sonic welded or solvent bonded to proximal portion  208  of housing  202 . 
       FIG. 4  depicts a cross section of the clamping assembly shown in  FIG. 3  taken along the lines  4 - 4 . As shown in  FIG. 4 , extension conduit  106  runs through the center of housing  202 . Cradle  310  is connected to the slide tab  204  with metal spring member  302  resting on the cradle  310 . 
       FIGS. 5 and 6  depict the clamping assembly  200  in a closed state. As shown in  FIG. 5 , the slide tab  204  is moved to the proximal end of housing  202 .  FIG. 6  shows a cross section of the clamping assembly  200  of  FIG. 5  taken along the lines  6 - 6 . In clamping assembly  200 , metal spring member  302  is in its normally closed position which pinches or clamps the extension conduit  106  at portion  602  thereby obstructing the flow of fluid through the conduit  106 . 
     During operation of the clamping assembly  200 , when the slide tab  204  is near the proximal end of the housing  202 , the metal spring member  302  is in its normal position and pinches the extension conduit  106  at portion  602  as shown in  FIG. 6 . When the slide tab  204  is placed in the distal position, the cradle  310  straightens the normally curved or closed metal spring member  302  thereby placing the clamp in an open state as shown in  FIG. 3 . 
       FIG. 7  depicts another embodiment of a clamping assembly  700 . Similar to clamping assembly  200  of  FIG. 2 , clamping assembly  700  has a housing  702  with a slide tab  704  that runs along a track  706 . At the proximal end of housing  702  is a male luer adaptor  708  formed integral to housing  702  that receives a corresponding female luer adaptor  712  of a dialysis conduit from a dialysis system to provide a seal between extension conduit  106  and the dialysis conduit. 
       FIG. 8  is a cross section of the clamping assembly shown in  FIG. 7  taken along the lines  8 - 8 . As shown in  FIG. 8 , clamping assembly  700  has a metal spring member  802  that can be deflected without yielding. The distal end  804  of metal spring member  802  is curved and rests against an inner wall of housing  702 . The proximal end  806  of metal spring member  802  is bonded or molded in place in male luer adaptor  708  to secure the metal spring member  802  to the clamping assembly  700  in one embodiment. Metal spring member  802  is biased to a normally closed position which would clamp the extension conduit  106 . Metal spring member  802  extends through a cradle  810  connected to slide tab  704 . The distal end of housing  702  terminates at the end of a chamber defined by housing  702  and is positioned over the extension conduit  106  snugly to secure the extension conduit inside the housing  702 . Extension conduit  106  may be bonded to the distal end of housing  702  to prevent relative movement between the extension conduit  106  and housing  702 , such as through the use of adhesives, solvent bonding, sonic welding or a press fit between at least one end portion of the housing  702  and the extension conduit  106 . Unlike clamping assembly  200  of  FIGS. 2 and 3 , housing  702  does not have a distal portion  201  to position the extension conduit  106  in place. Female luer adaptor  712  is similar to adaptor  212  and has an annular projection  714  and annular projection  716 . Shrink sleeve  718  is also provided to provide a leak proof seal. 
       FIG. 9  depicts another embodiment of a catheter assembly  900 . Catheter assembly  900  includes a catheter  102 , a hub  104  and extension conduits  106 . Catheter assembly  900  additionally includes a pair of clamping assemblies  200  operatively associated with each extension conduit  106 . Attached to the proximal end of each clamping assembly  200  is an extension conduit  902  that is terminated by a luer connector  904 . Luer connector  904  allows a clinician to easily connect and disconnect extension conduit  902  from conduit  906  which leads directly or indirectly to a dialysis system  150  (as shown schematically in  FIG. 9 ). 
       FIG. 10  depicts a clamping assembly  1000  in accordance with another embodiment of the present disclosure. Clamping assembly  1000  is similar to clamping assembly  200  in that clamping assembly  1000  has a housing  1010 , a deflecting member or slide tab  1020  and a track  1030 . The proximal and distal ends of clamping assembly  1000  each have a male luer adaptor  1040  that is fluidly connected to a female luer adaptor  1050 . 
       FIG. 11  depicts a cross section of the clamping assembly  1000  of  FIG. 10  taken along the lines  11 - 11 . As can be seen in  FIG. 11 , the clamping assembly  1000  has a conduit  1018  extending from the proximal end to the distal end of the clamping assembly  1000 . Adjacent to conduit  1018  is biasing element or metal spring member  1012  having a distal curved end  1016 . Proximal end  1014  of biasing element  1012  is bonded or formed in male luer adaptor  1040 . Biasing element  1012  rests in cradle  1022  which is attached to slide tab  1020 . Each female luer adaptor  1050  is similar to adaptor  212  and has an annular projection  1052  and annular projection  1054 . Shrink sleeve  1060  is provided to provide a leak proof seal. Clamping assembly  1000  is removable from a catheter assembly by removing each female luer adaptor  1050  from the clamping assembly  1000 . 
       FIG. 12  depicts a clamping assembly  1200  in accordance with another embodiment of the present disclosure. Clamping assembly  1200  is similar to clamping assembly  200  in that clamping assembly  1200  has a housing  1220 , a deflecting member or slide tab  1230  and a track  1240 . Distal end  1250  and proximal end  1260  of clamping assembly  1200  secure a conduit  1210  extending through the clamping assembly  1200 . One end of conduit  1210  may be fluidly coupled or connected to a catheter and the other end of the conduit  1210  may be fluidly coupled or connected to a dialysis unit (not shown). 
       FIG. 13  depicts a cross section of the clamping assembly  1200  of  FIG. 12  taken along the lines  13 - 13 . As can be seen in  FIG. 13 , the clamping assembly  1200  has a conduit  1210  extending through the distal end  1250  and proximal end  1260  of the clamping assembly  1200 . Adjacent to conduit  1210  is biasing element or metal spring member  1300  having a distal curved end  1320 . Proximal end  1310  of biasing element  1300  is bonded or formed in proximal end  1260 . Biasing element  1300  rests in cradle  1232  which is attached to slide tab  1230 . Clamping assembly  1200  is movable relative to conduit  1210 . 
     It will be understood that various modifications may be made to the embodiments of the presently disclosed clamping assemblies. For instance, the presently disclosed clamping assemblies may clamp any conduit capable of transferring fluid from one point to another. Therefore, the above description should not be construed as limiting, but merely as exemplifications of embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the present disclosure.