Abstract:
A port spike for medical fluid containers, such as infusate bags, for example, provides two ports to permit recirculation of fluids within the container. The recirculating flow allows bubbles to settle out which can&#39;t happen effectively if the flow is sucked out immediately after entering the container. The spike provides two openings inside the container which prevent such short-circuit flow by ensuring that fluid entering the container is not greatly affected by the suction zone of the flow leaving the container.

Description:
FIELD OF THE INVENTION  
       [0001]     The invention generally relates to access used for providing two openings to a fluid container, for example, an infusible fluid bag such as saline.  
       BACKGROUND OF THE INVENTION  
       [0002]     Air needs to be eliminated from many kinds of fluid circuits. For example, in extracorporeal blood circuits, air in replacement fluid that is injected into a patient can be hazardous. Typically; drip chambers are used in such circuits because these may serve as air traps. Another device is air-trapping filters. There exists a need for effective and convenient techniques for removing air from such circuits.  
       SUMMARY OF THE INVENTION  
       [0003]     The invention provides systems and devices for handling air in a fluid processing circuit. U.S. patent application Ser. No. 09/905,171, incorporated by reference as if fully set forth herein in its entirety, describes systems for priming a replacement fluid circuit of a hemofiltration machine by recirculating fluid through a replacement fluid reservoir. Gas settles out of solution in the reservoir as the fluid is recirculated. The replacement fluid reservoir used in hemofiltration systems is commonly in the form of a fluid bag as used for sterile infusates such as saline or glucose solutions. To make a double-access to the bag to facilitate the recirculation, of the replacement fluid, a connector device is employed which consists, in part, of a bag spike with two flow channels. The single spike can be forced into a port that is sealed by a membrane until being perforated by the spike. Fluid flow out an inlet opening at the tip of the spike and is drawn from the bag through an outlet opening at the base of the spike.  
         [0004]     One problem that may arise in connection with the spike discussed in the above application is that some fluid bags have long tube-shaped ports which surround the entire length of the spike so that the inlet and outlet openings both lie in a narrow tubular channel. The confinement of the outlet to the narrow channel can cause short-circuit flow that does not permit bubbles to settle out of the flow injected into the reservoir.  
         [0005]     The present invention solves the problem of short-circuit flow in a double-access connector by various means, for instances, by providing that a distance between the outlet opening be located at a point within the greater interior volume of the bag. This can be achieved by extending the tip of the spike until it is long enough to reach outside the tube-shaped port of the fluid bag.  
         [0006]     Various features of the double access spike provide for reliable insertion and use for recirculation. For example, the tip may be beveled to provide a sharp point that eases the piercing of the membrane. The outlet opening may be formed in a rounded or beveled surface located at the very tip. In addition, the inlet opening may be provided on a second beveled surface whose edges are rounded to allow it to pass through the membrane easily. In a preferred configuration, the beveled surface is conical to ease insertion. Another feature is that the lower portion is made substantially larger than the upper portion, the latter being so narrow as to not make a tight fit into the port. This requires that the spike be inserted all the way into the port to obtain a seal. The transition to a wide diameter base of the spike may be made an abrupt one and the inlet opening located sufficiently far away from the base to guarantee its placement in the larger volume of the bag. Other features and variations on the invention will be apparent from the detailed description below.  
         [0007]     According to an embodiment, the invention is a multiple access container connector for use with fluid containers having elongated access extensions that has a body with an elongated shaft. The elongated shaft has a base, a tip, and an inlet orifice at the tip and an outlet orifice. The body has an inlet flow channel to couple for flow an inlet port at the base to the inlet orifice and an outlet flow channel to couple for flow an outlet port at the base to the outlet orifice. The elongated shaft has a length to ensure the inlet orifice is insertable beyond the elongated access extension.  
         [0008]     In this embodiment, the body may have a base shaft substantially coaxial with the elongated shaft and located at the base, the base shaft having a diameter large enough to provide a compression seal with an opening of the elongated access neck. A transition portion of the body between the elongated shaft and the base shaft may be characterized by a progressively increasing cross-sectional area that is effective to ease a forcing of the connector through any obstacles in the elongated extension. The elongated shaft may have a diameter that is too small to provide a compression seal with an opening of the elongated access neck. The outlet opening may be located at the base. Where the body has a base shaft substantially coaxial with the elongated shaft and located at the base, the base shaft may have a diameter large enough to provide a compression seal with an opening of the elongated access neck. In such as, the elongated shaft may have a diameter that is too small to provide a compression seal with an opening of the elongated access neck. This ensures the connector is inserted well into the elongated access extensions of some fluid containers, such as fluid bags used for infusible fluids.  
         [0009]     According to another embodiment, the invention is a connector for use with fluid containers having access ports with elongated necks. The connector has a body constructed for coupling to a fluid container, a first fluid passage in the body, a second fluid passage in the body that does not communicate with the first fluid passage. A first assembly communicating with the first fluid passage and including a first fitting to releasably couple the first fluid passage to an outlet of a fluid circuit and to convey fluid only through the first fluid passage is also provided. A second assembly communicates only with the second fluid passage and includes a second fitting to releasably couple the second fluid passage to an inlet of the fluid circuit. As a result, fluid can be circulated through the fluid container in a loop that includes the fluid circuit to collect in the fluid source air residing in the fluid circuit. The body has an elongated portion sufficiently long to ensure an outlet of the first fluid passage can reach into the fluid container and beyond a neck of the container.  
         [0010]     In this embodiment, one end of the connector body may be tapered to form a spike. At least one of the first and second assemblies may include a luer fitting. At least one of the first and second assemblies may include an in-line clamp. The body may include a distal end communicating with the fluid source, wherein the first and second fluid passages each exits the distal end, and wherein the first fluid passage exits the distal end of the body at a higher gravity height that the second fluid passage exits the distal end. The base of the body near the releasable connectors may be wider than near the tip such that if the connector is not fully inserted in a port, the fluid will leak. This configuration may help to ensure the connector is fully inserted so the outlet is well within the container.  
         [0011]     The invention may be embodied in several forms without departing from its spirit or essential characteristics. The scope of the invention is defined in the appended claims, rather than in the specific description preceding them. All embodiments that fall within the meaning and range of equivalency of the claims are therefore intended to be embraced by the claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]      FIG. 1A  illustrates a fluid circuit and fluid reservoir or tank coupled to circulate fluid and thereby eliminate gases in fluid or other light constituents.  
         [0013]      FIG. 1B  is an illustration of a double access spike with ports that may be susceptible to short circuit flow when used in a narrow channel.  
         [0014]      FIG. 1C  is an illustration of a double access spike in a fluid bag port with a narrow channel.  
         [0015]      FIG. 2A  is a plan view of a preferred embodiment of a double access spike.  
         [0016]      FIG. 2B  is a first side view of the spike of  FIG. 2A .  
         [0017]      FIG. 2C  is a front view of the spike of  FIGS. 2A and 2B .  
         [0018]      FIG. 2D  is bottom view of the spike of  FIG. 2A -C.  
         [0019]      FIG. 2E  is a second side view of the spike of  FIG. 2A -D.  
         [0020]      FIG. 2F  is a section view of the spike of FIGS.  2 A-E taken along the section shown in  FIG. 2E .  
         [0021]      FIG. 3A  is a bottom oblique view of the spike of FIGS.  2 A-F.  
         [0022]      FIG. 3B  is a top oblique view of the spike of FIGS.  2 A-F and  3 A.  
         [0023]      FIG. 3C  is a side view of a spike with a conical transition from an elongated shaft portion to a base shaft portion.  
         [0024]      FIG. 4A  illustrates a fluid container with a port protected by a removable plug and a puncturable membrane.  
         [0025]      FIG. 4B  illustrates the fluid container of  FIG. 4A  with the spike of FIGS.  2 A-F and  3 A-B inserted in the port.  
         [0026]      FIGS. 5 and 6  illustrate two further embodiments of dual access spikes.  
         [0027]      FIGS. 7A and 7B  are illustrations of an elongated access spike with inlet and outlet openings that are both near a tip thereof.  
         [0028]      FIG. 7C  illustrates a variation of the embodiment of  FIGS. 7A and 7B  with a wide base portion on a shaft thereof.  
         [0029]      FIG. 7D  illustrates a spike with an elongated shaft that is not quite long enough to reach within a container, but which is near a boundary such that flow is not retarded by the port tube. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0030]     Referring to  FIG. 1A , a fluid reservoir  410  supplies fluid via a supply channel  415  to a fluid circuit represented schematically at  420 . The fluid circuit  420  may be a blood treatment systems such as dialysis or hemofiltration. Fluid may be conveyed with the assistance of a pump  435 , which, although shown separately may form part of the fluid circuit  420 . The fluid reservoir  410  may be connected temporarily to allow a return flow  425  and may employ two accesses to the reservoir  410 .  
         [0031]     Referring now to  FIG. 1B , a spike shown generally at  300 , has a pointed tip  365  and inlet and outlet openings  336  and  337 , respectively, near the tip  365 . A handle portion  325  facilitates insertion of the spike  300  into a container port (not shown in this figure, but described below). An inlet tube  345  supplies fluid through a channel  335  to the inlet opening  336 . An outlet tube  340  draws fluid through a channel  330  from the outlet opening  337 . An elongated shaft  375  has a uniform diameter for sealing in the container port.  
         [0032]     Referring now also to  FIG. 1C , a container  320  has a port tube  360  into which the shaft  375  is forced to form a seal and provide communication between the inlet tube  345  and the outlet tube  340  and the interior of the container  320 . The tube port  360  of the container  320  is common in fluid bags used for infusible fluids such as saline solution and other medical fluids. Fluid flows into a greater interior  312  of the container  320  where bubbles  310  may settle out into the container  320  thereby reducing the amount of bubbles in the fluid leaving through the outlet opening  337 . For some fluid circuits, such a removal process may be performed prior to a treatment, as described in the patent application incorporated by reference above.  
         [0033]     Some manufacturers of containers  320 , such as fluid bag-types, provide port tubes  360  that are much longer than others. As a result, for some types, the tip  365  may not extend into the greater interior  312 . When that occurs, fluid entering the container  320  from the inlet opening  336  may take a short-circuit path into the outlet opening  337 . This is due, in part, to the fact that the outlet flow from the outlet opening  336  is confined within an interior flow space  331  defined by the port tube  360 . The high flow resistance overcomes the inertia of the initial flow slowing it down and keeping the outlet flow close to the suction zone of the flow back into inlet opening  337 .  
         [0034]     Referring to  FIGS. 2A-3D  and  3 A and  3 B, a double-access spike  10  has an elongated extension shaft portion  22  that is substantially circular in cross-section with a single outlet port  18  at a tip  24  thereof. An inlet port  20  is located adjacent a base shaft portion  14  that has a substantially larger diameter than the extension shaft portion  22 . Each of the inlet and outlet ports  18  and  20  communicates with inlet and outlet connection ports  34  and  36 , respectively.  
         [0035]     A shelf  12  facilitates a user&#39;s ability to grasp the spike  10  and force it into a port (shown in  FIGS. 4A and 4B  and discussed below). Flange portions  32  provide structural rigidity. Tubing (not shown) may be inserted into the ports  34  and  36  and bonded to the ports  34  and  36  and later plugged and sterilized as a unit. A sloped and curved portion  28  allows the base shaft portion  14  to be forced easily through any cover, such as a membrane (not shown) or other covering that might be present in the container port. An alternative embodiment of the sloped and curved portion  28  is shown in  FIG. 3C . In that embodiment, a conical portion  28 A provides a similar function and may be advantageous in terms of ease of use.  
         [0036]     A protrusion  33  may be incorporated on the outside of the extension shaft portion  22  to cut through any sealing material that might seal around the extension shaft portion  22  thereby allowing a user to force the spike  10  less than fully into a container port (not shown). This is explained in connection with  FIGS. 4A and 4B , below.  
         [0037]     The spike  22  may be supplied as part of a complete fluid circuit as described in the patent application incorporated by reference above. The spike  10  may be manufactured from injection-molded plastic material. It may be formed in one or more parts of identical or different materials. For medical applications, the spike  10  is preferably made from bio-compatible materials.  
         [0038]     Referring to  FIG. 4A , a typical fluid container in the form of a fluid bag  521  has a port extension  530  with an access  516  protected by a removable plug  515 . A membrane  520  maintains the container  521  in a sealed state, protecting contents  525 , until the membrane  520  is punctured by a conventional spike or one such as spike  10  of the foregoing figures.  
         [0039]     Referring now also to  FIG. 4B , the sealed container  521  membrane  520  is shown after accessing using a spike  10  as illustrated in the foregoing figures. The extension shaft portion  22  extends well into an interior  526  of the container  521 . The protrusion  33  ensures that the membrane  520  is sufficiently disrupted—stretched or cut—upon insertion of the extension shaft portion  22  through the port extension  530  that fluid  525  will leak unless the base shaft portion  14  is forced well into the access  516 . If the base shaft portion  14  is sized to form a seal with the access  516 , then the penetration of the extended shaft portion  22  will be ensured, assuming that the user is motivated to avoid leaks.  
         [0040]     By ensuring the extended shaft portion  22  extends well into the interior volume  526 , the inlet opening  18  may be certain to be located well within the interior  526  and well beyond an interior  531  of the port shaft  530 . This helps to ensure against short-circuit flow because the momentum of an inlet flow  540  carries any gases well inside the interior volume  526  thereby substantially avoiding a suction zone  527  near the outlet opening  20  created by an outlet flow through the outlet opening  20 .  
         [0041]     Referring now to  FIG. 5 , another embodiment of a double access spike  605  has a tapered shaft  610  with an inlet opening  616  near its tip  619  and an outlet opening  617  near its base  618 . Inlet and outlet ports  623  and  624  are provided for attachment of respective tubes  622  and  620 . A base portion  634  is provided to ensure that the spike  605  is inserted well into a port (e.g.  516  of  FIG. 4A ).  
         [0042]     Referring to  FIG. 6 , yet another embodiment of a double access spike  641  has a cone-shaped forming a tapered shaft  640  that is open to hold a tube  645  therewithin. An inlet opening  643  at the end of the tube  645  is near the tip  642  of the shaft  640 . An outlet opening  660  is provided in a spherical base portion  655 . The inlet and outlet openings  643  and  660  communicate with respective ports  662  and  662 . The diameter of the base portion  655  ensures that the spike  641  is inserted well into a port (e.g.  516  of  FIG. 4A ). The open shape of the shaft  640  forms a recess  646  within whose blind end the tube  645  resides and whose access ensures that fluid  525  ( FIG. 4A ) in the container interior  526  ( FIG. 4A ) is able to reach the opening  660 . This is so because the shaft  640  creates an opening in the membrane  650  if present.  
         [0043]     Referring again to  1 B and  1 C and also to  FIGS. 7A and 7B , depending upon the size and shape of the container  320 , it may be possible in many cases to avoid short-circuit flow solely by means of placing the outlet opening  336  well into the greater volume  312  of the container. This may be achieved by extending the shaft  375  of the spike  300  so until it is long enough to ensure the outlet opening  336  is well outside the interior flow space  331  of the port tube  330 . An embodiment  300 A with such an extended shaft  375 A is shown in  FIGS. 7A and 7B . The other features of the embodiment of  FIGS. 7A and 7B  are the same as those of  FIGS. 1B and 1C . The extension of the outlet opening  336  into the larger interior space  312  allows the outlet flow&#39;s momentum to carry it far away from the return flow out through the outlet opening  337 .  
         [0044]     A refinement of the embodiment of  FIGS. 7A and 7B  is illustrated in  FIG. 7C . A spike  700  has an elongated shaft  770  that is long enough to bring inlet and outlet openings  777  and  778  well beyond the narrow flow space of some fluid bags. But the shaft  770 , unlike the embodiments of  FIGS. 1B, 1C ,  7 A, and  7 B, has a shaft  770  that is too narrow to seal the port tube (not shown in  FIG. 7C , but as described with reference to other figures). A wider base shaft portion  780  seals the port tube. This ensures a user will force the spike  700  well into the port tube thereby ensuring the outlet opening is beyond the narrow flow space defined by the flow tube.  
         [0045]     Referring to  FIG. 7D , the reach of a spike  390  may not have to be all the way into a fluid container  396  to avoid short-circuit flow. If the length is such as to reduce flow friction within a port tube  392  of the container  396 , then the inlet flow will not be subject to crossflow. How close an outlet  399  has to be to a greater interior  398  of the container  396  may depend on the diameter of the port tube  392  and other considerations, the crucial issue being whether there is sufficient momentum relative to frictional losses (both turbulent and viscous) to provide that most of the gases in the inlet flow will avoid being sucked back into the outlet flow. However, although it may be overkill in some cases, this can be assured by placing the outlet  399  well away from the port tube  392 , although shorter lengths such as illustrated in  FIG. 7D  are considered to be within the scope of the invention.  
         [0046]     Referring back to Figs.  FIGS. 2A-3D  and  3 A and  3 B, in a preferred embodiment of the invention, the distance from the shelf  12  to the inlet opening  24  is about 2 to 2.5 inches while that from the shelf  12  to the outlet opening  20  is about half an inch. In a broader definition of a preferred embodiment, the lengths are chosen such as to be compatible with fluid containers currently having an inlet tube of 1.5 inch length or more.  
         [0047]     While not specifically described above, variations on the above embodiments can benefit from various of the features described above. For example, an outlet opening a tip of a spike need not face in an upward direction, but may also be configured to eject flow sideways into a fluid container. Also, the number of accesses is not necessarily limited to two. The configuration features described can be applied in spikes with more than two openings connected to various different fluid circuits or joined to common fluid circuits. Also, the seal between the spike and bag need not be a compression seal as illustrated in the above embodiments. For example, a luer-type connector could be used or any other type of fitting. Also, while a sharp spike is described above, in some applications, a sharp point may be superfluous. For example, where a container does not require the puncturing, for example of a membrane, a sharp tip may not be useful.  
         [0048]     It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.