Abstract:
A method and apparatus provides for sterilizing a device in a container. The method comprising the steps of: a) placing the device into the container; b) processing the device, the container and a lid for the container in a sterilization process with the lid separated from the container; and c) after sterilizing a contact surface on the container where the lid meets the container, and while maintaining the container and the lid in a sterile environment, placing the lid onto the container, whereby to prevent contamination of the device upon its removal from the container via contact with the contact surface.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to sterilization of medical instruments, and specifically to sterilization employing a container to contain the instruments. 
         [0002]    After use reusable medical instruments must be both washed and then sterilized before they can be reused. They are placed into a container at the point of use and then transported to the hospital central supply area for further processing. Typically, washing is performed either by hand using a detergent and mechanical scrubbing devices such as brushes, are in a machine which typically directs jets of detergent laid in water at the device to effect cleaning. The devices are contaminated with potentially dangerous pathogens which require the personnel performing such cleaning to wear appropriate protective gear such as gloves, gowns, masks etc. 
         [0003]    After the device has been washed it is decontaminated, which typically comprises a brief contact with a decontaminating agent such as bleach or steam sufficient to kill the most dangerous pathogens such as hepatitis. They are then processed for sterilization. This typically involves each instrument being packaged in a semi-permeable pouch permeable to a sterilizing agent yet impermeable to microorganisms, or by being packaged into a tray which is then wrapped in CSR wrap which is semi-permeable. It is then placed into and processed in a sterilizer such as a steam sterilizer or a hydrogen peroxide gas plasma sterilizer such as the STERRAD Sterilizer available from Advanced Sterilization Products Division Ethicon, Inc., Irvine, Calif. Such a sterilizer is depicted in U.S. Pat. No. 6,365,102, which is hereby incorporated by reference. 
         [0004]    Containers having removable lids and semi-permeable filters through which sterilizing gasses can enter are a popular form of containment for instrument sterilization. After sterilization the instruments are kept in the container which maintains their sterility. However, sterilization of the contact area where the lid meets the container is difficult and personnel removing the sterile instruments from the container must be careful not to touch this area lest the sterility be compromised. 
       SUMMARY OF THE INVENTION 
       [0005]    A method according to the present invention provides for sterilizing a device in a container. The method comprising the steps of: a) placing the device into the container; b) processing the device, the container and a lid for the container in a sterilization process with the lid separated from the container; and c) after sterilizing a contact surface on the container where the lid meets the container, and while maintaining the container and the lid in a sterile environment, placing the lid onto the container. Accordingly, whereby to prevent contamination of the device upon its removal from the container via contact with the contact surface. 
         [0006]    Preferably, steps b) and c) occur within a sterilization chamber and a machine performs step c). Preferably, while the container is in the chamber and prior to step b), the machine removes the lid from the container. In one aspect of the invention, the lid affixes to the container via a hinge and the step of removing the lid comprises rotating the lid about the hinge and away from the container. In a different aspect of the invention, the lid is completed separated from the container. 
         [0007]    In one aspect of the invention, the lid and the container are placed into the chamber separated from each other during step a). 
         [0008]    Preferably, the sterilization process comprises contacting the device, the container and the lid with vapor phase hydrogen peroxide. 
         [0009]    Preferably, steps b) and c) are controlled via a computer control system. 
         [0010]    In one aspect of the invention, between steps a) and b) the container, the lid, the contact surface and the device are washed. The washing may comprise directing a detergent solution over the container, lid, contact surface and device, followed by directing rinse water thereover, followed by directing a solution of hydrogen peroxide thereover. 
         [0011]    A system according to the present invention provides for sterilizing a device. The system comprises a sterilization chamber, and a container having a lid and adapted to receive the device within. A source of sterilizing media connects to the chamber whereby to sterilize items within the chamber. A mechanism provides for sealing the lid to the container within the chamber whereby to allow a contact surface on the container where the lid meets the container to be sterilized prior to attaching the lid to the container. 
         [0012]    Preferably, a control system is provided for controlling a sterilization process within the chamber and for controlling the mechanism with the control system being programmed to perform the sterilization process with the lid separated from the contact surface and after the contact surface is sterilized and while an environment within the chamber is still sterile sealing the lid to the container. 
         [0013]    Preferably, the sterilizing media comprises hydrogen peroxide. 
         [0014]    In one aspect of the invention, means are provided for guiding the lid into a proper position upon the container. Such means can comprise a hinge between the lid and the container. 
         [0015]    In one aspect of the invention, a source of washing fluid is connected to the chamber whereby to wash items within the chamber. Preferably it includes a recirculation system and nozzles for washing items within the chamber with the washing fluid. It may also include an ultrasound transducer on the chamber for ultrasonically agitating items immersed within the washing fluid within the chamber. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]      FIGS. 1   a  and  1   b  are side elevation views of a container according to the present invention. 
           [0017]      FIGS. 2   a  and  2   b  are cut-away side elevation views of a chamber according to the present invention receiving the container of  FIG. 1   a.    
           [0018]      FIG. 3  is a block diagram of an integrated sterilization and washing system according to the present invention incorporating the chamber of  FIG. 2   a.    
           [0019]      FIG. 4   a  is a side elevation view of an alternative container according to the present invention. 
           [0020]      FIG. 4   b  is an end elevation view of the container of  FIG. 4   a.    
           [0021]      FIG. 4   c  is a side elevation view of the container of  FIG. 4   a , shown with its top and bottom removed. 
           [0022]      FIGS. 5   a  and  5   b  are cut-away side elevation views of a chamber according to the present invention receiving the container of  FIG. 4   a.    
           [0023]      FIGS. 6   a  and  6   b  are side elevation views of a container according to the present invention. 
           [0024]      FIGS. 7   a  and  7   b  are side elevation views of a container according to the present invention. 
           [0025]      FIG. 7   c  is a side elevation view of a chamber for receiving the container of  FIG. 7   a.    
           [0026]      FIG. 8   a  is a side elevation view of a container according to the present invention. 
           [0027]      FIG. 8   b  is a cut away side elevation view of a chamber according to the present invention receiving two of the containers of  FIG. 8   a.    
           [0028]      FIG. 9  is an exploded perspective view of a container according to the present invention. 
           [0029]      FIGS. 10   a  and  10   b  is a cut away side elevation view of a chamber according to the present invention receiving the container of  FIG. 9 . 
           [0030]      FIG. 11  is a cut away side elevation view of an integrated washer/sterilizer according to the present invention. 
           [0031]      FIG. 12  is a cut away side elevation view of the washer/sterilizer of  FIG. 11  showing a packaging apparatus. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0032]      FIGS. 1   a  and  1   b  show a container  10  for receiving one or more medical instruments  12 . The container comprises a bottom  14  and upstanding sidewalls  16 . A lid  18  fits to the top of the sidewalls  16  to seal the container  10 . The bottom  14  is sloped and has a drain  20  with a closure valve  22 . A grid  24  rests slightly above the bottom  14  and supports one or more instrument receiving baskets  26 . Both the grid  24  and baskets  26  are preferably formed from a mesh having large enough holes to freely pass cleaning solution and may be formed of stainless steel, aluminum, polyethylene, polypropylene, or styrene, TEFLON polytetrafluoroethylene and other suitable materials. Several bosses  28  project from a lower surface  30  of the lid  18  and engage with meeting channels  32  in the sidewalls  16  to help position the lid  18  correctly. First and second valved openings  34  and  36  enter the container  10  through one of the sidewalls  16 . Also, brackets  38  on the lid  18  are provided for machine grasping. 
         [0033]    Turning now also to  FIGS. 2   a  and  2   b , the container  10  is shown within a chamber  40 . A pair of lifting rods  42  are adapted to engage the brackets  38  and can be employed for automatically opening and closing the lid  18  while the container  10  is positioned within the chamber  40 . Although a mechanical interaction is shown, other methods of engaging the lid could be employed such as an electromagnetic connection. First and second lines  44  and  46  connect to the first and second valved openings  34  and  36  respectively and can further include their own valves  48 . A transducer  50  is provided for opening and closing the container drain valve  22 . It can physically actuate the valve  22  or, alternatively, electrically or electromagnetically actuate the valve  22 . Agitators  52  and ultrasound transducers  54  are provided for exciting the washing fluid within the container  10  to enhance cleaning ethicacy. The chamber  40  itself has several openings including a valved drain  56  and an inlet  58 . Spacers and guides  60  are provided for providing proper positioning of the container  10  within the chamber  40 . 
         [0034]    Turning now also to  FIG. 3 , the chamber  40  is shown within an integrated sterilization washing system  62 . A circulation line  64  connects to first and second lines  44  and  46  respectively and has a recirculation pump  66 . City water can enter through line  68  under control of a valve  70 . Alternatively, fluid can flow into the container and chamber from both fluid lines  44  and  46 , and flow out from drains  20  and  58 . A cleaning fluid injection system  72  meters and delivers cleaning fluid from a reservoir  74 . One preferable cleaning solution is ENZOL enzymatic cleaning solution available from Advanced Sterilization Products Division of Ethicon, Inc. in Irvine, Calif. Line  76  connects to the chamber inlet  58  and also to a vacuum pump  78 , a germicide injection system  80  and a vent  82  with a filter  84  for allowing sterile filtered air to enter the chamber  40 . An actuator  86  is provided for operating the lifting rods  42 . A control system  88  controls the devices within the system  62 , provides feedback to a user and allows entry of information about the instruments to be cleaned from a user. 
         [0035]    The cleaning and sterilization starts with placing contaminated devices in a container. Preferably, this occurs at the point of use, such as in an operating room. The container may be filled with soaking fluid to prevent contaminates on the devices from drying and becoming more difficult to remove. The soaking fluid may comprise a liquid solution of cleaning and/or sterilization chemicals, or more preferably a foam of comprising an enzymatic cleaner or hydrogen peroxide. After the container is sealed, the contaminants and pathogens are sealed inside and the container may be transported by personnel not wearing protective gloves, garments etc. 
         [0036]    The container is then inserted into the chamber  40  and the chamber  40  is sealed. The chamber  40  may be heated to enhance the cleaning and sterilization process. Preferably, the chamber is heated to 30° C. to 60° C. The lifting rods  42  lift the lid  18 . The soaking fluid may be used for further cleaning or drained. Preferably, it is drained and rinsed by opening the drain  22  and flowing water in through the opening  34 . The drain  22  is then closed and the container  10  is filled with a cleaning solution comprising water and concentrated cleaning fluid from the reservoir  74 . This is re-circulated by the pump  66 . If the additional agitation of the agitators  52  and ultrasound transducers  54  is required then the drain  22  is left open and the chamber  40  also filled with cleaning solution. By separating the lid from container, it exposes one most likely contaminated area between the lid  18  and container  10  for cleaning and sterilization. Rinsing fluid is then used to remove the cleaning chemicals. The rinsing fluid may be city water, DI water or distilled water. 
         [0037]    Next, germicide is admitted to the chamber  40 . The germicide may be introduced as liquid, mist, vapor, or gas to treat the devices, container and chamber. The germicide may comprise hydrogen peroxide, peracetic acid, performic acid, or ozone. The sterilization process may be hydrogen peroxide vapor from pre-treated liquid peroxide or solid peroxide complex. It may be steam or ethylene oxide. Preferably, the sterilization process comprises admitting heated air through inlet  58  to dry the chamber  40  and its contents followed by sealing the chamber and lowering the pressure via the vacuum pump  78  to below 1 torr whereupon a 59% hydrogen peroxide solution is vaporized into the chamber  40  and left in contact with for a sufficient period of time to effect sterilization of the container  10  and the instruments  12  therein. After the sterilization is completed, the lid  18  and drain  20  are all closed and the container is ready to be removed from the chamber  40 . The sterility of the instruments  12  is maintained by the sealed container  10 . 
         [0038]      FIGS. 4   a ,  4   b  and  4   c  show an alternative container  100 . It comprises a removable lid  102  and removable bottom  104  each with locating bosses  106  as in the previous container. Flanges  108  are provided on two opposing sidewalls  109 . Turning also now to  FIGS. 5   a  and  5   b , the container  100  is disposed within a chamber  110  similar to the previous chamber  40 . Retaining members  112  fit within the flanges  108  to position the container  100  within the chamber  110 . Upper lifting rods  114  and lower lifting rods  116  are provided for controlling opening and closing of the top  102  and bottom  104 . In all other respects the container  100  and chamber  110  operate as in the previous embodiment with the added advantage of the bottom  104  being able to be removed during the process to enhance access of the cleaning fluid to the instruments during the cleaning procedure. 
         [0039]      FIGS. 6   a  and  6   b  show an alternate version of a container  120 . It has a lid  122  which attaches to the container  120  via a hinge  124 . The hinge  124  helps ensure that the lid  122  will be properly positioned upon the container  120  when it is pushed into the closed position. 
         [0040]      FIGS. 7   a ,  7   b  and  7   c  show a container  126  having a lid  128  attached via a hinge  130  and a bottom  132  attached via a hinge  134 . Flanges  136  along its side portions function to hold the container similar to the flanges  108  of the container  100  of  FIG. 4 . A chamber  138  for receiving the container  126  as sloping upper and lower surfaces  140  and  142  to accommodate a container  126  with its lid  128  and bottom  132  opened. Upper and lower lifting rods  144  and  146  are provided for engaging brackets  148  on the lid  128  and bottom  132 . 
         [0041]      FIG. 8  shows a container  150  similar to the container  126  with the exception that it has hinges  152  for its lid  154  and bottom  156  on opposite side, thus allowing an alternate packing arrangement within a chamber  158 . 
         [0042]      FIG. 9  shows an alternative version of a container  160  comprising an inner basket  162 , having upwardly extending silicone fingers  163  to limit shifting of items within the basket  162 . The basket  162  rests on a bottom  164 , which can either be removable or attached to the basket  162 . Sidewalls  166  and a lid  168  are also removable. Spring loaded latches  170  hold the lid  168  to the sidewalls  166  and the sidewalls  166  to the bottom  164 . 
         [0043]    Turning also to  FIGS. 10   a  and  10   b , the container  160  is shown within a chamber  172 . Lid lifting arms  174  engage brackets  176  on the lid  168  and side lifting arms  178  engage flanges  180  on the sidewalls  166  and their upward force disengages the latches  170  and exposes the basket  162  for better access of the washing fluid. When the sidewalls  166  and lid  168  are lowered the latches  170  automatically engage and seal the container  160 . 
         [0044]      FIG. 11  shows in an alternative arrangement in which an integrated washer and sterilizer  182  is separated into a separate washing section  184  and sterilization section  186  separated by a movable partition  188 . It employs a container  190  having an internal basket  192  on a bottom  194  and a removable cover  196  comprising sidewalls  198  and a top  200 . Brackets  202  on the top  200  allow lifting arms  204  to place the cover  196  onto the bottom  194  and seal the container  190 . Washing and rinsing occur in the washing section  184  where cleaning fluid is sprayed through nozzles  206  onto items in the basket  192 . Ultrasound transducers and agitators (not shown in  FIG. 11 ) as in previous embodiments may be employed in place of or in addition to the nozzles  206 . 
         [0045]    After the washing cycle the partition  188  is opened, the basket  192  is pushed via an actuator  208  into the sterilization section  186  and the partition  188  closed. In the sterilization section  186  a sterilization process employing steam or vapor phase chemical sterilization is carried out. Preferably, it involves a vapor phase hydrogen peroxide process via vaporizing a liquid peroxide solution or releasing hydrogen peroxide from a solid peroxide complex as previously described. After the process is complete the cover  196  is lowered onto the bottom  194  to seal the container  190  and maintain the sterility of the instruments therein. 
         [0046]    Optionally, semi-permeable filters  210  can be provided on the container  190  to allow a vapor phase sterilization process to be carried out with the cover  196  sealed to the bottom  194 . Further, the container  190  having a cover  196  which leaves the basket  192  open during both cleaning and sterilization can be employed with any of the previously described chambers. 
         [0047]      FIG. 12  shows the integrated washer/sterilizer  182  with an automated packaging apparatus  212 . A pouch  214  is pre-loaded onto a collapsible frame  216  with an open end  218  facing the washing section  184 . The pouch is made of a semi-permeable material permeable to sterilizing gasses and impermeable to sterilant vapors. Suitable materials include TYVEK (spunbonded olefin) or SMS (spunbond polypropylene, melt blown polypropylene, spunbond polypropylene). As the basket  192  or tray is pushed into the sterilizing section  186  it enters the pouch  214  which is then sealed closed with a heat sealing iron  220  which lowers to compress and seal the pouch  214  at the opening  218 , or alternatively sealed via adhesive at the opening  218 . After the instruments are sealed within the pouch  214  the sterilization cycle occurs. 
         [0048]    With separated washing  184  and sterilization sections  186 , the system  182  can be operated as a washer and a sterilizer simultaneously, or an integrated washer/sterilizer and can be adapted to many cleaning, disinfecting and sterilization techniques. The packaging may be performed between cleaning and sterilization or after sterilization. Optionally, the packaging area and sterilization area can be separated with a removable divider. If packaging is not required, then the sterilization process may only occur in the sterilization area. Optionally, the packaging area may be located on the same level as the cleaning area and sterilization area. The packaging area may be located between cleaning area and sterilization area, or after the sterilization area. The packaging can be performed with container, pouch or wrap. The following examples represent a few of the many possible processes. 
       EXAMPLE A 
       [0049]    Step 1: Loading a load in wire basket or tray into the right-most cleaning area 
         [0050]    Step 2: Cleaning the load in the cleaning area. Optionally, this step may include detergent, surfactant, enzyme, cleaning chemical, spray, agitation, or ultrasound. 
         [0051]    Step 3: Rinsing the load with water. Preferably, the water is distilled water, or DI water. 
         [0052]    Step 4: Treating load with liquid hydrogen peroxide. Preferably, the liquid is in the form of mist. 
         [0053]    Step 5: Moving load into the middle packaging area. 
         [0054]    Step 6: Sliding load into an open gas permeable pouch and sealing the pouch. Optionally, the packaging may be a container with gas permeable barrier or CSR wrap. 
         [0055]    Step 7: Moving load into the right-most sterilization area. 
         [0056]    Step 8: Reducing the pressure to below the vapor pressure of hydrogen peroxide. 
         [0057]    Step 9: Sterilizing the load with vaporized peroxide. Optionally, the process further comprises exciting the atmosphere into plasma to complete the process. 
       EXAMPLE B: 
       [0058]    Step 1: Loading a load in wire basket or tray into the right-most cleaning area. 
         [0059]    Step 2: Cleaning the load in the cleaning area. Optionally, this step may include detergent, surfactant, enzyme, cleaning chemical, spray, agitation, or ultrasound. 
         [0060]    Step 3: Rinsing the load with water. Preferably, the water is distilled water, or DI water. 
         [0061]    Step 4: Moving the load into the middle packaging area. 
         [0062]    Step 5: Sliding the load into an open gas permeable pouch and sealing the pouch. Optionally, the packaging may be a container with a gas permeable barrier or CSR wrap. 
         [0063]    Step 6: Moving the load into the right-most sterilization area. 
         [0064]    Step 7: Sterilizing the load. 
       EXAMPLE C: 
       [0065]    Step 1: Loading a load in wire basket or tray into the cleaning area. 
         [0066]    Step 2: Cleaning the load in the cleaning area. Optionally, this step may include detergent, surfactant, enzyme, cleaning chemical, spray, agitation, or ultrasound. 
         [0067]    Step 3: Rinsing the load with water. Preferably, the water is distilled water, or DI water. 
         [0068]    Step 4: Moving the load into the sterilization area. 
         [0069]    Step 5: Sterilizing the load. 
         [0070]    Step 6: Moving the load into the packaging area. 
         [0071]    Step 7: Packaging the load with sterile pouch, container or CSR wrap. 
       EXAMPLE D: 
       [0072]    Step 1: Placing a load into a container with lid. 
         [0073]    Step 2: Loading the container into the integrated washer/sterilizer  182 . Optionally, the washer/sterilizer can be a washer/decontaminator or washer/disinfector. 
         [0074]    Step  3 ; Opening the lid. Optionally, the bottom can be opened. 
         [0075]    Step 4: Cleaning the load, container and lid. Optionally, this step may include detergent, surfactant, enzyme, cleaning chemical, spray, agitation, or ultrasound. 
         [0076]    Step 5: Rinsing the load, container, and lid with water. Preferably, the water is distilled water, or DI water. 
         [0077]    Step 6: Sterilizing the load, container and lid. 
         [0078]    Step 7: Closing the container. 
       EXAMPLE E: 
       [0079]    Step 1: Placing a load into a container with lid. 
         [0080]    Step 2: Soaking the load with soaking fluid. Optionally, the soaking fluid may include detergent, surfactant, enzyme, or peroxide. The soaking fluid may be liquid or foam. Optionally, the container has a soaking indicator to indicate the proper soaking of load (both the soaking fluid is deep enough to cover the instruments and that the time period is sufficient). 
         [0081]    Step 3: Loading the container into the integrated washer/sterilizer. Optionally, the washer/sterilizer can be a washer/decontaminator or washer/disinfector. 
         [0082]    Step  4 ; Opening the lid. Optionally, the bottom can be opened. 
         [0083]    Step 5: If necessary, further cleaning the load, container and lid. Optionally, this step may include detergent, surfactant, enzyme, cleaning chemical, spray, agitation, ultrasound, or defoaming agent. 
         [0084]    Step 6: Rinsing the load, container, and lid with water. Preferably, the water is distilled water, or DI water. 
         [0085]    Step 7: If necessary, further decontaminating, disinfecting, or sterilizing the load, container and lid. 
         [0086]    Step 8: If necessary closing the container. 
         [0087]    A simple use for the containers, such as the container  10 , and systems and chambers, such as chamber  40  as shown in  FIGS. 1   a ,  1   b ,  2   a ,  2   b  and  3 , is to provide an automated washing and decontamination procedure which is sealed from human contact such that the personnel do not require elaborate protective garb. This process would be followed by a traditional packaging and sterilization. In such a process the instruments  12  are placed into the container  10  as their use is completed in a procedure. They are covered with a soaking fluid or foam and then the container is sealed. It can now be transported to and loaded into the chamber  40  by personnel who are not in full protective garb. In the chamber  40  the lid  18  is opened, the drain valve  22  is opened and the instruments are rinsed. The drain valve  22  is then closed and the container  10  is filled with a cleaning solution comprising water and concentrated cleaning fluid from the reservoir  74 . This is re-circulated by the pump  66 . If the additional agitation of the agitators  52  and ultrasound transducers  54  is required then the drain valve  22  is left open and the chamber  40  also filled with cleaning solution. By separating the lid from container, it exposes one most likely contaminated area between the lid  18  and container  10  for cleaning and decontamination. Rinsing fluid is then used to remove the cleaning chemicals. The rinsing fluid may be city water, DI water or distilled water. Then the instruments are decontaminated, i.e. disinfected sufficiently so as to allow safe inspection and handling of the instruments. Preferably, this would be a flash cycle comprising pumping down the chamber to below 1 torr, vaporizing 59% percent hydrogen peroxide into the chamber and contacting the instruments for five minutes. Alternatives include a short steam cycle, or immersion in a liquid peroxide solution, or other liquid sterilants such as orthophthalaladehyde, followed with a rinse. The instruments  12  are now safe for inspection, handling and packaging for sterilization. Replacing the lid  18  automatically is optional, although probably the most convenient for the operating personnel. 
         [0088]    While the invention has been particularly described in connection with specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation, and that the scope of the appended claims should be construed as broadly as the prior art will permit.