Patent Abstract:
A method of collecting medical waste in a waste collection unit using a disposable manifold and filter assembly. The disposable manifold and filter assembly includes a manifold housing with a plurality of inlets, a neck extending from the manifold housing to define an outlet, and a filter basket disposed in the manifold housing. The method includes inserting the neck into the waste collection unit to direct the medical waste passing through the disposable manifold and filter assembly into the waste collection unit. Tubes are connected to the inlets of the manifold housing to provide a path for the medical waste to travel from a target site, e.g., a patient, to the manifold housing. A vacuum is drawn in the waste collection unit to pull the medical waste through the tubes and into the disposable manifold and filter assembly where the medical waste is processed/filtered in a plurality of stages.

Full Description:
RELATED APPLICATIONS 
       [0001]    This application is a divisional of application Ser. No. 11/060,977, filed on Feb. 18, 2005, which claims the benefit of U.S. Provisional Patent Application No. 60/545,974, filed Feb. 19, 2004, the advantages and disclosures of each of which are hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to a method of collecting medical waste in a waste collection unit. More specifically, the present invention relates to a method of collecting medical waste in the waste collection unit using a disposable manifold and filter assembly to direct and filter medical waste, e.g., bodily fluids and materials, entering the waste collection unit. 
       BACKGROUND OF THE INVENTION 
       [0003]    Waste collection units are well known for use in surgical environments to collect medical waste such as bodily fluids and materials during a surgical procedure. Examples of waste collection units can be found in U.S. Pat. Nos. 5,997,733; 6,180,000; and 6,222,283. For instance, U.S. Pat. No. 5,997,733 discloses a waste liquid and smoke disposal system which combines the functions of a smoke extraction system and a waste collection unit, typically in, but not limited to, a surgical environment. The smoke extraction system and the waste collection unit are connected to supply the medical waste collected thereby to a waste treatment (e.g. decontamination and/or sterilization) and disposal system. In such systems, the waste collection unit can be provided as a cart-mounted apparatus to provide mobility. The waste collection unit can then dock to known docking stations to dispose of the medical waste collected by the unit. As a result, surgical teams can quickly, easily, and efficiently maintain the integrity of a surgical site with a minimum of operating components. 
         [0004]    Disposable manifold and filter assemblies are used to facilitate the collection of the medical waste into the waste collection unit. Typically, the manifold and filter assembly includes at least one filter to remove solid or semi-solid material such as bone chips, flesh, blood clots or the like from the medical waste generated by the surgical procedure or operation. The manifolds are disposed of between patients, or when the manifold is spent, i.e., filled with solid and semi-solid materials. An example of a disposable manifold for use in waste collection units is described in U.S. Pat. No. 6,331,246 to Beckham et al. 
         [0005]    The &#39;246 patent discloses a manifold and filter assembly for use with a waste collection unit to filter medical waste generated during a medical process. The manifold and filter assembly includes a manifold housing, inlet ports, an outlet port, and a series of filters disposed between the inlet and outlet ports. The filters retain solid and semi-solid materials from a fluid carrier entering the manifold housing through the inlet ports. Check valves are placed on the inlet ports to establish unidirectional flow. Currently, once the filters are plugged with debris, the manifold housing begins to fill with the medical waste. The check valves ensure that the medical waste does not reverse flow into the inlet ports. However, there is a need in the art for a manifold and filter assembly that includes a bypass to prevent the medical waste from reaching the inlet ports. 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    The present invention provides a method of collecting medical waste in a waste collection unit using a disposable manifold and filter assembly. The disposable manifold and filter assembly includes a manifold housing having a bottom wall and a peripheral wall. The manifold housing defines a chamber and at least one inlet for the medical waste to enter into the chamber. A neck is disposed on the bottom wall of the manifold housing and extends downwardly therefrom to define at least one outlet. A filter basket is mounted in the chamber between the at least one inlet and the at least one outlet. The filter basket has a basket bottom wall with a first plurality of openings and a basket peripheral wall with a second plurality of openings. The second plurality of openings are spaced a predetermined distance from the first plurality of openings. The basket bottom wall is spaced from the manifold bottom wall and the basket peripheral wall is spaced from the manifold peripheral wall to define a fluid bypass between the manifold housing and the filter basket. 
         [0007]    The method of the present invention includes inserting the neck of the disposable manifold and filter assembly into a waste inlet of the waste collection unit to direct the medical waste passing through the disposable manifold and filter assembly into the waste collection unit. At least one tube is connected to the at least one inlet of the manifold housing to provide a path for the medical waste to travel from a target site to the disposable manifold and filter assembly. A vacuum drawn in the waste collection unit pulls the medical waste through the at least one tube and into the disposable manifold and filter assembly where the medical waste is processed in a plurality of stages. 
         [0008]    The plurality of stages includes a first stage in which the medical waste is filtered through the first plurality of openings in the basket bottom wall until the basket bottom wall becomes plugged with filtered-out material and the medical waste rises the predetermined distance to the second plurality of openings. The plurality of stages further includes a second stage, following the first stage, in which the medical waste is filtered through the second plurality of openings in the basket peripheral wall until the basket peripheral wall becomes plugged with filtered-out material and the medical waste rises to the fluid bypass. The plurality of stages includes a third stage, following the second stage, in which the medical waste enters the fluid bypass to bypass around the filter basket. 
         [0009]    By providing this staged filtering/processing, life of the disposable manifold and filter assembly of the present invention can be prolonged. In particular, the third bypass stage allows the medical waste to flow around the filter basket once the filter basket is spent. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0010]    Advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: 
           [0011]      FIGS. 1 and 2  are exploded views of the manifold and filter assembly of the present invention; 
           [0012]      FIG. 3  is a cross-sectional view of an outlet of the manifold and filter assembly illustrating a check valve disposed therein; 
           [0013]      FIG. 4  is a cross-sectional view illustrating a snap-fit connection between a manifold cap and manifold body of the manifold and filter assembly; 
           [0014]      FIG. 5  is a cross-sectional view of the manifold and filter assembly; 
           [0015]      FIGS. 6 and 7  are cross-sectional perspective views of the manifold and filter assembly; 
           [0016]      FIGS. 8-11  are cross-sectional perspective views of the manifold and filter assembly illustrating various stages of use; 
           [0017]      FIG. 12  is a cross-sectional perspective view of the outlet illustrating the check valve in a closed position; 
           [0018]      FIG. 13  is an exploded view of an alternative manifold and filter assembly of the present invention; 
           [0019]      FIG. 14  is a cross-sectional view of the alternative manifold and filter assembly with a filter basket in a closed position; 
           [0020]      FIG. 15  is a blown-up view of a resilient tab of the filter basket holding the filter basket in the closed position; 
           [0021]      FIG. 16  is a cross-sectional view of the alternative manifold and filter assembly with the filter basket in an open position; 
           [0022]      FIG. 17  is a blown-up view of the resilient tab of the filter basket flexing to place the filter basket in the open position; 
           [0023]      FIG. 18  is a perspective view of a waste collection unit in which the manifold and filter assemblies could be used. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0024]    Referring to the Figures, wherein like numerals indicate like or corresponding parts throughout the several views, a manifold and filter assembly of the present invention is generally shown at  10 . The assembly  10  is intended for use with waste collection units to collect medical waste such as bodily fluids and materials from patients during medical procedures. Examples of waste collection units can be found in U.S. Pat. Nos. 5,997,733; 6,180,000; and 6,222,283, all incorporated herein by reference. Another example of a waste collection unit is shown at  15  in  FIG. 18 . 
         [0025]    Referring to  FIGS. 1 and 2 , the assembly  10  has a base  12 . The base  12  includes a cup-shaped manifold body  16  and a neck  14  (outlet tube  14 ) extending downwardly from the manifold body  16  to define an outlet  19 . The neck  14  is adapted to be inserted into an inlet of a waste collection unit, such as the inlet  17  of the waste collection unit  15  shown in  FIG. 18 . The manifold body  16  defines a chamber  18 . The chamber  18  is shown as being generally circular, but it should be understood by those of ordinary skill in the art that numerous other shapes could be used as effectively, for example, oval, square, rectangular, triangular, etc. The manifold body  16  has a bottom  31  and a peripheral wall  32  extending upwardly from the bottom  31  to define the chamber  18 . 
         [0026]    A filter basket  20  is adapted to fit within the chamber  18  of the manifold body  16 . The filter basket  20  includes a bottom  41  and a peripheral wall  30  extending upwardly from the bottom  41 . In the disclosed embodiment, a locking tab  22  is disposed on the bottom  31  of the manifold body  16  and extends upwardly therefrom. The locking tab  22  is adapted to snap-lock into a locking member  24  on the bottom  41  of the filter basket  20 . As should be appreciated, there could be more than one locking tab  22  and locking member  24  if desired. In the disclosed embodiment there are three of each spaced approximately one hundred and twenty degrees relative to a center of the manifold body  16 . Further, other types of locking methods could be employed to lock the filter basket  20  in the chamber  18 , such as, for example, threaded connections, other connectors, welding, etc. 
         [0027]    Spacers  26  are provided on the peripheral wall  30  of the filter basket  20 . The spacers  26  engage the peripheral wall  32  of the manifold body  16  in order to provide a fluid bypass  28  between the peripheral wall  30  of the filter basket  20  and the peripheral wall  32  of the manifold body  16 . The fluid bypass  28  can be seen for example in  FIG. 4 . The spacers  26  also provide the filter basket  20  with a semi-rigid configuration to support the filter basket  20  in the chamber  18 . 
         [0028]    In the disclosed embodiment, the manifold body  16  includes risers  34  disposed on the bottom  31  of the manifold body  16  and extending from the bottom  31  into the chamber  18 . These risers  34  provide further support for the filter basket  20  and space the filter basket  20  from the bottom  31  of the manifold body  16  (see  FIG. 5 ). 
         [0029]    The filter basket  20  also includes a plurality of openings in fluid communication with the fluid bypass  28 . The plurality of openings are further defined as a first plurality of perforations or holes  42  defined in the bottom  41  of the filter basket  20  and a second plurality of perforations  36 , preferably vertical slots  36 , defined in the peripheral wall  30  of the filter basket  20 . The slots  36  provide fluid communication between an interior of the filter basket  20  and the fluid bypass  28 . The bottom  41  of the filter basket  20  has a number of compartments  38  which are defined by a plurality of interior walls  40 , preferably in a grid. A portion of the holes  42  are defined in a bottom of each of the compartments  38 . These compartments  38  are illustrated in a waffle-like pattern, however, other patterns could be used, for example, circles, triangles, rectangles, etc. Referring particularly to  FIG. 2 , the holes  42  define a filtering screen. This screen filters the medical waste between the interior of the filter basket  20  and the space formed between the filter basket  20  and the bottom  31  of the manifold body  16 . 
         [0030]    A porous filter element  44  having a predetermined height is disposed within the filter basket  20 . The filter element  44  allows the medical waste which enters the filter basket  20  to be filtered and then passed through the slots  36  into the fluid bypass  28 . As shown, the filter element  44  is annular in shape. The filter element  44  is supported about and extends upwardly along the peripheral wall  30  of the filter basket  20  thereby requiring the medical waste to pass through the filter element  44  to reach the slots  36 . The filter element  44  retains filtered-out material, e.g., debris, in the interior of the filter basket  20  such that debris slowly builds upward along the predetermined height of the filter element  44  to maximize a filtering capacity of the filter element  44  and the filter basket  20 . Both the filter basket  20  and the filter element  44  act as filtering members, however, the filter basket  20  is preferably more rigid than the filter element  44 . 
         [0031]    A manifold cap  46  closes the manifold body  16 . The manifold cap  46  includes a plurality of inlets  48 . Each of the inlets  48  includes an entrance tube  49  disposed about an entry axis A. The entrance tubes  49  are disposed above the fluid bypass  28  such that the medical waste can enter the fluid bypass  28  without flowing back through the inlets  48 . Preferably, all of the entry axes A are parallel. The outlet  19  extends downwardly from the bottom  31  of the manifold body  16  about an outlet axis B approximately normal to said entry axes A. 
         [0032]    The inlets  48  are adapted to be connected to tubes which extend to, for example, a patient undergoing surgery. The waste collection unit, such as the waste collection unit  15  of  FIG. 18 , typically has a vacuum source (not shown) which pulls a vacuum through the assembly  10  and the tubes to draw the medical waste from the patient into the assembly  10 . As shown, there are four inlets  48 , but there could be as little as one and as many as desired. With the four inlets  48  shown, in the event less than four inlets  48  are used, inlet port caps  50  are provided to close off the inlets  48  that are not being used. In addition, the inlet port caps  50  can be used to close off the inlets  48  during transportation. An outlet port cap  52  is shown for closing the neck  14  during transportation. As shown, integrally formed connection straps extend from the caps  50 ,  52  to the manifold cap  46 . 
         [0033]    Referring specifically to  FIG. 2 , an underside of the manifold cap  46  has a splash wall  56  which is configured to absorb fluid energy from the medical waste entering the assembly  10  from the inlets  48  by deflecting the medical waste as it enters the assembly  10  from the inlets  48  toward the filter basket  20 . To this end, the splash wall  56  is oriented normal to the entry axes A. The splash wall  56  guides the accumulation of the debris in such a way as to prolong the life of the assembly  10 . The splash wall  56  also contains features such as tabs  57  that serve to hold the filter element  44  in place. 
         [0034]    Referring to  FIG. 3 , a waste retention valve  54 , preferably a check valve  54 , is illustrated which fits within the neck  14  to contain any medical waste which may be in the assembly  10  during transportation or disposal. The check valve  54  is configured so that it will move to an open position when a predetermined pressure is applied thereto, e.g., when a predetermined vacuum is pulled within the assembly  10 . The check valve  54  is normally in a closed position and will automatically close when the vacuum is discontinued. In  FIG. 3 , the check valve  54  is shown in the open position as a result of the vacuum pulling the check valve  54  from the closed position shown in dotted lines  58 . A locking ring  55  is shown locking the check valve  54  in place. As shown, the locking ring  55  has an annular flange  60  which locks into a groove  62  formed in the neck  14 . 
         [0035]    Referring to  FIG. 4 , the manifold cap  46  is shown snap-fit to the manifold body  16 . As shown, the manifold body  16  has an outer rim  64  which is received by a mating inner rim  66  on the manifold cap  46 . In this way, a tab  68  can be raised to disengage the mating rims  64  and  66  to remove the manifold cap  46 , if desired. 
         [0036]    In the disclosed embodiment, the base  12 , filter basket  20  and manifold cap  46  are all made of plastic material, more preferably thermoplastic material, and are intended to be single-use items and disposed after each operation. The filter element  44  is made of filtering material such as plastic, steel wool, etc., and is also intended to be disposable. At least portions of the base  12 , filter basket  20 , and manifold cap  46  are made from a semi-transparent material. This allows a user to see into the chamber  18  and determine whether the assembly  10  requires disposal. 
         [0037]      FIGS. 5-7  are cross-sectional views of the assembly  10  showing the various components described above. 
         [0038]    Referring to  FIGS. 8-12 , operation of the assembly  10  will be described. As will be appreciated by those of ordinary skill in the art, the assembly  10  is inserted into the inlet  17  of the waste collection unit  15 . The waste collection unit  15  has a vacuum source that draws a vacuum in the waste collection unit  15  thereby drawing the medical waste from the patient, e.g., from a surgical site, through tubes  72  connected to the inlets  48 . The medical waste is illustrated by numeral  74 . 
         [0039]    Referring to  FIG. 8 , the medical waste  74  enters the assembly  10  through at least one of the inlets  48 . A coupling is shown coupling the tube  72  to the inlet  48 . Those of ordinary skill in the art will appreciated that numerous other couplings could be used to attach the tube  72  to the inlet  48 . In fact, the tube  72  could be directly attached at the inlet  48 . As illustrated, caps  50  are shown closing the additional inlets  48  which are not being used in this illustration. 
         [0040]    The medical waste  74  is drawn into the assembly  10  and engages the splash wall  56 . There, the medical waste  74  is deflected downwardly into the filter basket  20 . The medical waste  74  begins to collect in one of the compartments  38  and is filtered by the holes  42  in the respective compartments  38 . The medical waste  74  then enters the space between the bottom  31  of the manifold body  16  and the filter basket  20  and is pulled, by vacuum, into the outlet  19 . As illustrated, the check valve  54  is drawn downwardly to the open position to allow the filtered medical waste to enter a collection area of the waste collection unit  15 . The holes  42  screen any debris, e.g., solid or semi-solid materials such as bone chips, flesh, blood clots, or the like, from the medical waste  74  that may otherwise be drawn into the assembly  10 , so that they do not enter the outlet  19 , and subsequently the waste collection unit  15 . 
         [0041]    Referring to  FIG. 9 , the medical waste  74 , which is entering the assembly  10 , is compartmentalized within the compartments  38  allowing the other compartments  38  to remain open and free of the medical waste  74 . This allows the vacuum which is being pulled to continue to draw the medical waste into the assembly  10 . In the event any one or more of the compartments  38  becomes clogged with debris and/or fluid, the other compartments  38  are still open and continue to allow sufficient vacuum for operation of the assembly  10 . Here, the compartments  38  are becoming full. However, additional compartments  38  remain open allowing the vacuum to continue to be drawn through the assembly  10 . 
         [0042]    Referring to  FIG. 10 , the compartments  38  have become clogged and filled with debris and fluid. However, the vacuum is still able to be pulled through the assembly  10  through the filter element  44  and the slots  36 . Now, the filter element  44  acts to filter out the debris from the medical waste  74 . Thus, filtered medical waste  74  is now drawn into the fluid bypass  28  formed between the peripheral wall  30  of the filter basket  20  and the peripheral wall  32  of the manifold body  16 . 
         [0043]    Finally, referring to  FIG. 11 , the filter basket  20  is spent and unable to further filter the medical waste  74 . The medical waste  74  is now to the point that it has filled the filter basket  20 . At this point, the medical waste  74  flows over top of the filter element  44  and the peripheral wall  30  of the filter basket  20  through a space  76  formed between the manifold cap  46  and a top of the filter element  44 . The medical waste  74  flows from the space  76  into the fluid bypass  28  and then through the outlet  19 . Due to this space  76 , the assembly  10  will continue to allow the medical waste  74  to be pulled in through the inlets  48 . In other words, the assembly  10  will not become filled to the point that no vacuum is pulled through the assembly  10 . As a result, the space  76  ensures that the vacuum will continually be pulled even though the filter basket  20  has become completely filled with the medical waste  74 . Additionally, the space  76  is small enough so that larger debris pulled into the assembly  10  will be blocked and prevented from entering the waste collection unit  15 . This space  76 , along with the fact that the inlets  48  are disposed above each of the space  76 , the top of the filter element  44 , and the top of the peripheral wall  30  of the filter basket  20 , ensure that no cross-contamination between inlets  48  occurs. 
         [0044]    Referring to  FIG. 12 , the check valve  54  is shown when the vacuum has been stopped. The check valve  54  draws into its normally closed position within the outlet  19  of the neck  14  and also serves to seal the outlet  19 . In this way, the assembly  10  can be removed from the waste collection unit  15  without the medical waste  74  leaking or dripping from the neck  14 . 
         [0045]    Referring to  FIGS. 13-17 , a further embodiment of the present invention is illustrated. In this embodiment, the same numbers will be used to indicate similar components. Generally, in this embodiment, the space  76  is controlled so that it is only opened when a load on the filter basket  20  exceeds a predetermined load or threshold, such as when the filter basket  20  is full of the medical waste  74 , or when the vacuum results in a load on the filter basket  20  exceeding the predetermined load. 
         [0046]    Referring to  FIGS. 14 and 15 , there is no space  76  between the manifold cap  46  and the filter basket  20 , i.e., the fluid bypass  28  is closed. Resilient members  80  in the form of flexible fingers or tabs  80  extend outwardly from the peripheral wall  30  of the filter basket  20  and rest on a shoulder  83  defined in the peripheral wall  32  of the manifold body  16 . The flexible fingers  80  act as springs to springably bias the filter basket  20  upwardly so that filter basket  20  engages the manifold cap  46 . It should be understood that any form of resilient member or biasing member would work, such as for example a leaf or coil spring. 
         [0047]    Referring to  FIGS. 16-17 , the flexible fingers  80  are shown in their flexed position creating the space  76  between the filter basket  20  and the manifold cap  46 , i.e., the fluid bypass  28  is open. The flexible fingers  80  have been flexed because the filter basket  20  has become full and/or the vacuum has pulled the filter basket  20  downward exposing the space  76 . As will be appreciated, the medical waste  74  can now flow through the space  76  into the fluid bypass  28  and ultimately through the outlet  19 . 
         [0048]    There has been shown and described a unique design and concept of a manifold and filter assembly. It is understood that those skilled in the art may conceive of modifications and/or variations to the specific embodiments shown and described herein. Any such modifications or variations which fall within the purview of this description are intended to be included herein as well. It is understood that the description herein is intended to be illustrative only and is not intended to be limited. Rather, the scope of the invention described herein is limited only by the claims appended hereto.

Technology Classification (CPC): 1