Patent Abstract:
A tube clamp includes (i) a tube holding portion; (ii) a first arm extending from a first end of the tube holding portion; (iii) a second arm extending from a second end of the tube holding portion, the second armed curved so that a first catch located at a distal end of the second arm can be snap-fitted to the first arm to occlude a first tube extending through the tube holding portion; and (iv) wherein the first arm includes a locking feature configured such that when a second tube clamp is mated with the tube clamp, the locking feature interacts with a second catch of the second tube clamp so that the second tube clamp is prevented from occluding a second tube.

Full Description:
BACKGROUND 
       [0001]    The present disclosure relates generally to medical fluid handling and in particular to the packaging and sterilization of medical fluid bags or containers. 
         [0002]    It is known to package a sterile medical fluid, such as dialysis fluid, in medical fluid bags. The bags in many instances are provided with tubing preconnected to the bags. This tubing needs to be sterilized. One method of sterilization is steam sterilization. Steam sterilization is advantageous over other forms of sterilization, such as ethylene oxide (“EtO”) sterilization, which requires the application of a vaporized chemical, and gamma radiation, which can leave an odor and/or discolor the sterilized item. 
         [0003]    One requirement for steam sterilization however is that the surface to be sterilized must be adequately contacted by the steam. Failure to do so will result in an improperly sterilized item. 
         [0004]    The bag tubing set is often provided with one or more external clamp, such as a Robert™ clamp. For various reasons, the external clamps may become partially or fully closed or clamped, for example, during shipping or during the sterilization process itself It is desirable to pre-attach the external clamps prior to shipping and sterilization, creating the need for an apparatus and method to prevent the external clamps from becoming inadvertently locked or closed prior to sterilization. 
       SUMMARY 
       [0005]    The present disclosure sets forth an apparatus and method for preventing the inadvertent closure or clamping of an external clamp provided on a tubing set. The apparatus includes a clamp that is configured to mate with a second like clamp in such a way that the clamps interlock and prevent each other from being closed or clamped inadvertently until the matched clamp pair is pulled apart manually. The method includes positioning each of two manual clamps over a separate tube, so as to face opposite directions, and then sliding the clamps over their respective tubes towards each other until the oppositely facing clamps snap-fit together in an interlocking relationship. Doing so also routes the respective tubes together desireably at the interlocked clamps. 
         [0006]    It is contemplated to structure the external clamps in different ways to enable mated pairs of clamps to be interlocked together. In each case, the clamps are generally U-shaped, wherein the rounded base of the U defines a tube holding aperture. The inner wall of the rounded base of the tube holding portion transitions to a pair of clamping jaws. The clamping jaws occlude the tubing when the clamp is closed. 
         [0007]    First and second arms extend outwardly from the rounded base of the U or tube holding portion. A first arm is substantially straight and includes ratcheted ribs on its outer surface for the user to grip when closing the clamp. A second arm is rounded or curved and bends so that it terminates at a catch located near a distal end of the first arm. To close the clamp, the user pinches or compresses the ribbed arm towards the circular arm, such that the distal end of the straight arm engages and slides past the catch at the distal end of the curved arm. Doing so bends the curved arm outwardly to allow the distal end of the ribbed arm to slide past the catch, at which point the catch and distal end of the curved arm snap back to an unstressed and locked position. At such point, the distal end of the ribbed arm is trapped below the catch. The pinching of the first and second arms also pinches together the clamping jaws, which occludes the tube. When the user wishes to open the tube, the user pushes the catch away from the distal end of the straight arm, allowing the inherent springiness of the clamp and the compressed tube to open the clamp. 
         [0008]    The clamps of the present disclosure can be configured to be interlocked in a non-closeable position with another like clamp in at least three different ways. In a first way, a bump or protrusion is added to the first arm at the beginning of the ribs. The bump of a fist one of the clamps engages the catch of a second one of the clamps. Likewise the catch of the second clamp engages the bump or protrusion of the first clamp. In this manner the clamps are prevented from being moved towards or away from each other in a direction coincident with the axis of the tubing running through the clamps. Because the clamps are not readily able to be pulled apart from each other, the clamps are not readily able to become individualized, in which case the clamps could be compressed and closed, occluding the tubing. Also, first arms of each of the interlocked clamps prevent the second arms of the respective mated clamps from closing and locking to the end of the respective first arms. 
         [0009]    The bump or protrusion in one embodiment thickens the ribbed arm of the clamp, such that the curved arms of the mated clamps are locked at a position such that the clamps are more spread apart than if the ribbed arms had not been thickened. The additional spreading apart of the clamp arms also additionally spreads apart the clamping jaws, such that the tubes reside even more freely within the clamps. 
         [0010]    In a second embodiment, the bumps of the first embodiment are replaced with ramps. Here, the ribbed arm of each clamp is ramped beginning at the distal end or tip of the ribbed arm and ramps upwards as the ribbed arm extends towards its proximal end adjacent the rounded section of the U or tube holding portion of the clamp. At a desired point the ramp ends and steps down to the unramped thickness of the ribbed arm. The ramped clamps operate to restrain axial and compressive movement when mated in the same manner as the bumps or protrusions of first embodiment. The ramps indeed can be thought of as a modified bump or protrusion. 
         [0011]    In a third embodiment, the bumps or ramps are replaced with recess. The ends and catches of the second, curved arms snap into the recesses of the mated clamps. Axial and compressive movement is thereby prevented. 
         [0012]    It is accordingly an advantage of the present disclosure to provide an improved medical tubing clamp. 
         [0013]    It is another advantage of the present disclosure to provide an improved tubing sterilization apparatus. 
         [0014]    It is a further advantage of the present disclosure to provide an improved tubing sterilization method. 
         [0015]    Additional features and advantages are described herein, and will be apparent from the following Detailed Description and the figures. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0016]      FIG. 1  is a perspective view illustrating one application for the interlocking tube clamps of the present disclosure. 
           [0017]      FIG. 2A  is an elevation view of one embodiment of the interlocking tubing clamps of the present disclosure in a pulled apart condition. 
           [0018]      FIG. 2B  is an elevation view of the embodiment of the interlocking tubing clamps of  FIG. 2A  in an imbricated or interlocked condition. 
           [0019]      FIG. 3  is an elevation view of another embodiment of the interlocking tubing clamps of the present disclosure. 
           [0020]      FIG. 4  is an elevation view of a further embodiment of the interlocking tubing clamps of the present disclosure. 
           [0021]      FIG. 5  is an elevation view of yet another embodiment of the interlocking tubing clamps of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    One application for the interlocking tubing clamps of the present disclosure is a dual filled twin bag. One suitable twin bag is set forth in U.S. Pat. No. 6,196,991 (“the &#39;991 patent”) assigned to the assignee of the present disclosure, the entire content of which are expressly incorporated herein by reference and relied upon. As seen in FIGS. 1 and 2 of the &#39;991 patent, each bag of the twin bag assembly communicates with a tube. The tubes are Y-d together at their distal ends to form a single outlet. 
         [0023]    Referring now to the drawings an in particular to  FIG. 1 , it is desirable to equip tubes  102  and  104  of twin bag assembly  100  with first and second external clamps  10   a  and  10   b,  even before the tubes  102  and  104  and bag interiors of twin bag assembly  100  are sterilized, such as steam sterilized. To prevent clamps  10   a  and  10   b  from being collapsed prior to or during sterilization, clamps  10   a  and  10   b  of the present disclosure have been configured such that the clamps are interlocked together until pulled apart. 
         [0024]    Referring now to  FIGS. 2A and 2B  to  5 , various embodiments of clamps  10   a  and  10   b  (referred to herein collectively as clamps  10  or generally, individually as clamp  10 ) are illustrated. Clamps  10  are molded from a suitable material, such as polyethylene and in particular high density polyethylene (“HDPE”, which has a desirable melting temperature and can be sterilized via gamma sterilization, steam sterilization and ethylene oxide (“EtO”)), acetal, nylon, polypropylene, or nylon with glass. Each embodiment includes certain common features, such as, a tube holding portion  12 , which defines an aperture (not seen) to allow a tube  102 ,  104  to extend through the tube holding portion as seen in  FIGS. 1  and  3 . Tube holding portion  12  extends in a cylindrical or semicircular manner in the illustrated embodiments, such that the aperture can be formed in the wall of the cylinder or semicircle. 
         [0025]    A first arm  14  extends from one end of semicircular tube holding portion  12  and is generally straight, albeit having a triangular configuration. As arm  14  extends towards its distal end  14   c,  the first arm  14  as illustrated can be provided with ribs  14   a  on its outside surface for a user to contact clamp  10 . Arm  14  is also provided with a triangular inner body  14   b,  which adds rigidity to first arm  14 . 
         [0026]    A second, curved arm  16  extends from the opposing end of semicircular tube holding portion  12 . Curved arm  16  curves back towards first arm  14  and terminates at a catch  18  having an edge  18   a  extending inward towards tube holding portion  12 . Edge  18   a  can be snap-fitted over distal tip  14   c  of first arm  14  to close clamps  10   a  and  10   b  after the interlocked clamps have been separated from each other. Curved arm  16 , like tube holding portion  12 , defines an aperture (not seen) in its wall to allow a tube  102 ,  104  to pass through clamp  10  as seen in  FIGS. 1 and 3 . 
         [0027]    Located between U-shaped holding portion  12  and first arm  14  is a first clamping jaw  20   a.  Located between holding portion  12  and second arm  16  is a second clamping jaw  20   b.  Clamping jaws  20   a  and  20   b  are pressed towards each other when catch  18  is moved to snap-fit edge  18   a  over distal tip  14   c  of first arm  14  to close clamp  10 . In the clamp closed position, clamping jaws  20   a  and  20   b  are spaced closely enough to each other to fully occlude tube  102 ,  104 , but are also spaced far enough away from each other so as not to require an undue amount of force from the user to close clamp  10 . To open clamp  10 , the user can pull catch  18  outwards to allow the natural springiness of clamp  10  and the compressed tube  102 ,  104  to force arm  14  away from arm  16  to allow the tube to be opened for fluid flow. 
         [0028]      FIGS. 2A and 2B  illustrate one embodiment for configuring clamps  10   a  and  10   b  so that they may be interlocked together. Here, outer ribbed surface  14   a  of first arm  14  is angled or raised radially up (about distal end  14   c ) from straight outer surface  14   d  of first arm  14  to form an edge  14   e,  against which an inner wall  18   b  of the catch  18  of the mating clamp  10  is abutted.  FIG. 2A  shows arms  16  and catches  18  pulled away from straight outer surface  14   d  of about 4.5 mm, e.g., by a distance suitable to allow tubes  102 ,  104  to not be deformed when clamps  10   a  and  10   b  are imbricated. If whatever force is pulling second arms  16  outwardly in  FIG. 2A  is released, arms  16  will snap back towards the first arm  14  of the mating clamp  10 , such that lower surfaces  18   c  of catches  18  will snap against straight outer surfaces  14   d  of arms  14  as seen in  FIG. 2B .  FIG. 2B  illustrates that even in the imbricated or interlocked position, tubes  102  and  104  are not deformed in one preferred embodiment. 
         [0029]    As illustrated in  FIG. 2B , in one embodiment edge  14   e  is indented so as to form an upper lip that extends around edge  18   a  of catch  18  to help hold clamps  10   a  and  10   b  together in the interlocked position. Here, inner wall  18   b  of catch  18  abuts edge  14   e  of first arm  14 . In  FIG. 2B , if the user tries to pull clamps  10   a  and  10   b  axially apart (along the axes of tubes  102  and  104 ), inner wall  18   b  of catch  18  will abut against edge  14   e  of the mating clamp  10 , precluding clamps  10   a  and  10   b  from being pulled apart unless enough force is applied to pull catches  18  up over edges  14   e  of the mating clamp  10 . 
         [0030]    As illustrated in  FIGS. 2A and 2B , distal tips  14   c  of arms  14  imbed against clamping jaws  20   a  of the mating clamps  10 , precluding the clamps  10   a  and  10   b  from being pushed axially together (along the axes of tubes  102  and  104 ). In essence, the embodiment of  FIG. 2B  locks raised ribbed surfaces  14   a  of clamps  10   a  and  10   b  between clamping jaws  20   a  and catches  18  of the mating clamp  10 . The snap-fitted abutment of lower surface  18   c  of catch  18  to the straight outer surface  14   d  of the mating clamp  10  prevents clamps  10  from being compressed or closed any further. The user can pull curved arms  16  apart as is shown in  FIG. 2A  to unlock clamps  10   a  and  10   b.    
         [0031]    Referring now to  FIG. 3 , bumps or protrusions  14   f,  each having a contact side, surface or edge  14   e,  replace the raised ribbed surfaces  14   d  of the embodiment of  FIGS. 2A and 2B . Otherwise, the embodiment of  FIG. 3  operates very much the same as the embodiment of  FIGS. 2A and 2B . In particular, lower surfaces  18   c  of catches  18  again snap against straight outer surfaces  14   d  of arms  14 . Afterwards, if the user tries to pull clamps  10   a  and  10   b  axially apart (along the axes of tubes  102  and  104 ), inner wall  18   b  of catch  18  will abut against contact side, surface or edge  14   e  of the bump  14   f  of the mating clamp  10 , precluding the clamps  10   a  and  10   b  from being pulled apart further unless enough force is applied to pull catches  18  up over edges  14   e  of the mating clamp  10 .  FIG. 3  also illustrates that even in the imbricated or interlocked position, tubes  102  and  104  are not deformed in one preferred embodiment. 
         [0032]    Again, distal tips  14   c  of arms  14  imbed against clamping jaws  20   a  of the mating clamps  10 , precluding the clamps  10   a  and  10   b  from being pushed axially together (along the axes of tubes  102  and  104 ). The embodiment of  FIG. 3  locks ribbed surface  14   a  and protrusion  14   f  of clamp  10  between clamping jaw  20   a  and catch  18  of the mating clamp  10 . The snap-fitted abutment of lower surface  18   c  of catch  18  to the straight outer surface  14   d  of the mating clamp  10  prevents clamps  10  from being compressed or closed any further. The user can again pull curved arms  16  apart to unlock clamps  10   a  and  10   b.    
         [0033]    Referring now to  FIG. 4 , bumps or protrusions  14   f,  each having a contact side, surface or edge  14   e,  are combined with an angularly or radially raised surfaces  14   a.  The embodiment of  FIG. 4  operates very much the same as the embodiments of  FIGS. 2A ,  2 B and  3 . Again, lower surfaces  18   c  of catches  18  snap against raised outer surfaces  14   d  of arms  14 . Afterwards, if the user tries to pull clamps  10   a  and  10   b  axially apart (along the axes of tubes  102  and  104 ), inner wall  18   b  of catch  18  will abut against contact side, surface or edge  14   e  of the bump  14   f  of the mating clamp  10 , precluding the clamps  10   a  and  10   b  from being pulled apart further unless enough force is applied to pull catches  18  up over edges  14   e  of the mating clamp  10 . 
         [0034]    Again, distal tips  14   c  of arms  14  imbed against clamping jaws  20   a  of the mating clamps  10 , precluding the clamps  10   a  and  10   b  from being pushed axially together (along the axes of tubes  102  and  104 ). The embodiment of  FIG. 4  locks ribbed surface  14   a  and protrusion  14   f  of clamp  10  between clamping jaw  20   a  and catch  18  of the mating clamp  10 . The snap-fitted abutment of lower surface  18   c  of catch  18  to the raised outer surface  14   d  of the mating clamp  10  prevents clamps  10  from being compressed or closed any further. The raised surfaces  14   d  also hold clamps  10   a  and  10   b  open by an extra distance D, which may be desirable to place even less compressive stress on tubes  102  and  104  during sterilization and prior the opening of clamps  10   a  and  10   b.  The user can again pull curved arms  16  apart to unlock clamps  10   a  and  10   b.    
         [0035]    Referring now to  FIG. 5 , recesses  22  formed in first arms  14  replaces the raised ribbed surfaces  14   a  and bumps  14   f  of the previous embodiments. Recesses  22  each have a proximal edge or surface  22   a,  a distal edge or surface  22   b  and a bottom surface  22   c.  Proximal edges or surfaces  22   a  contact the outer sides or surfaces  18   d  of catches  18  to prevent clamps  10   a  and  10   b  from moving inwards towards each other along the axes of tubes  102  and  104 , Distal edges or surfaces  22   b  contact the inner sides or surfaces  18   b  of catches  18  to prevent clamps  10   a  and  10   b  from being moved outwards with respect to each other along the axes of tubes  102  and  104 . Bottom surfaces  22   c  of recesses  22  contact the lower sides or surfaces  18   c  of catches  18  to prevent clamps  10   a  and  10   b  from being compressed occlude tubes  102  and  104 . As before, the user can pull curved arms  16  apart to unlock clamps  10   a  and  10   b  from each other. 
         [0036]    It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.

Technology Classification (CPC): 8