Abstract:
A seal arrangement for sealing a space between a sterilization unit and adjacent walls in order to separate first and second rooms has a double seal gasket arrangement with a seal chamber there within. The seal chamber may be pressurized with a fluid and then the pressure within the seal chamber monitored by a pressure sensor. The double seal assembly provides an arrangement which can give an indication of the quality of the seal in order to detect any leakage and a more secure seal around the sterilization unit and as a result secure separation between a sterile or contaminated room and a general hospital area.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to apparatus and a method for sealing zones or rooms, particularly in a medical environment, for instance to keep a zone or room sterilized or to isolate a contaminated area. 
       BACKGROUND ART 
       [0002]    There are many instances, particularly in a hospital environment, in which it is necessary to seal an area or room for medical purposes. For instance, some rooms must be kept highly sterilized and thus separate from the general hospital areas, while in other instances a contamination zone needs to be kept sealed. A transition between such zones, that is from a sterile or contaminated zone to a general area, normally provides for sterilization. For this purpose it is common to locate between the two rooms a sterilization unit, for instance an autoclave, which provides the entry and exit points between the rooms. Passage from one room to another must therefore be through the sterilization unit. 
         [0003]    In practice, an autoclave or other sterilization unit is fitted in an aperture of a wall between the two rooms and sealed to the walls by a sealing device, commonly a gasket or the like. The autoclave includes doors at either side, each leading to a respective room. 
         [0004]    A problem occurs with conventional arrangements in that it is difficult to verify the quality of the seals between the autoclave and the walls and thus whether there may be any leakage which compromises the cleanliness or containment. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention seeks to provide an improved apparatus and method of sealing zones or rooms, particularly in a medical environment. 
         [0006]    According to an aspect of the present invention, there is provided apparatus for sealing first and second zones from one another including: a sterilization unit disposable in a structure separating the first and second zones, the sterilization unit including a chamber and providing therethrough access to the first and second zones; a sealing unit disposed around at least a part of the sterilization unit, wherein the sealing unit includes first and second seal elements each providing a seal between the sterilization unit and the separating structure; filler material disposed between the first and second seal elements, wherein the filler material provides a measurable characteristic; and at least one sensor disposed to measure said measurable characteristic. 
         [0007]    The structure provides a sealing arrangement with a measurable indication of the quality of the seal achieved. Specifically, any leakage in the seals can be detected by a change in the measurable characteristic. Moreover, the use of two sealing elements provides a more secure seal, specifically for the sealing function to be maintained even when it is detected that there is a sealing element defect. Typically, any defects will not occur simultaneously in the two sealing elements, so that overall sealing will be maintained by non-compromised the sealing element even when it is detected that there is a sealing defect. The filler advantageously also provides a sealing function, thereby enhancing the overall effectiveness of the seal. 
         [0008]    Preferably, the first and second seal elements are spaced from one another, the filler material being disposed in said space. 
         [0009]    The filler material is advantageously a fluid, for example a liquid or a gas. 
         [0010]    In a preferred embodiment the measurable characteristic is pressure. It is to be understood, however, that other characteristics could be measured, such as colour, chemical constitution of the filler etc. 
         [0011]    In the preferred embodiment, the filler is of a nature able to escape from either of the seal elements when an incomplete seal between the sterilization chamber and adjacent structure occurs. 
         [0012]    In a practical embodiment, the apparatus includes a fitting element attachable to an adjacent structure and providing a support for the first and second seal elements. In other words, the apparatus includes the elements to be attached to a support structure to provide a solid sealed coupling thereto and the seals to the sterilization chamber. 
         [0013]    Typically, the sterilization chamber includes first and second doors for access therethrough. 
         [0014]    According to another aspect of the present invention, there is provided a method of sealing first and second zones from one another including the steps of: disposing a sterilization unit between said first and second zones and facing an adjacent structure, the sterilization unit providing therethrough access to the first and second zones; disposing a sealing unit around at least a part of the sterilization chamber, the sealing unit including first and second seal elements each providing a seal between the sterilization chamber and an adjacent structure; disposing filler material between the first and second seal elements; sensing for a change in at least one parameter of the filler unit over time and therefrom determining the quality of sealing. 
         [0015]    Other features and advantages will be apparent form the following description of preferred embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    Embodiments of the present invention are described below, by way of example only, with reference to the accompanying drawings, in which: 
           [0017]      FIG. 1  is a schematic diagram showing the basic arrangement of a sealed room; 
           [0018]      FIG. 2  is a schematic diagram illustrating the structure of a conventional sealing arrangement; 
           [0019]      FIG. 3  is a schematic diagram illustrating the structure of a preferred embodiment of sealing arrangement as taught herein; 
           [0020]      FIG. 4  is a schematic diagram illustrating in front elevation the structure of an example of autoclave; 
           [0021]      FIG. 5  is a side elevational view of the autoclave of  FIG. 4 ; 
           [0022]      FIG. 6  is a plan view of the autoclave of  FIG. 4 ; 
           [0023]      FIG. 7  is a cross-sectional view along lines A-A of  FIGS. 5 and 6  showing a preferred embodiment of sealing apparatus; 
           [0024]      FIG. 8  is a cross-sectional view along lines B-B of  FIG. 5  showing another view of the preferred embodiment of sealing apparatus; and 
           [0025]      FIG. 9  is a cross-sectional view along lines C-C of  FIG. 6  showing another view of the preferred embodiment of sealing apparatus. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0026]    It is to be understood that the accompanying drawings are schematic only and focus upon the salient elements of the apparatus taught herein. Elements of the apparatus and system which are not necessary from the understanding of the teachings herein have been omitted for the sake of clarity. It is also to be understood that the drawings are not intended to show any of the components to scale. 
         [0027]    Referring first to  FIG. 1 , this shows in schematic form the general arrangement for zone or room isolation. The arrangement separates two rooms or zones  10 ,  12  from one another, which in this example are delineated by a dividing wall  14  having an opening  16  therein. Disposed across the dividing wall  14  within the opening  16  is a sterilization unit  18 , typically an autoclave, in this example a steam sterilizer. The sterilization unit  18  includes a sterilization chamber  20  and opposing doors  22 ,  24  for access into the chamber  20  and between the rooms or zones  10 ,  12 . A sealing assembly  26  is disposed around the exterior of the sterilization unit  18  to seal any space or gap between the opening  16  and the sterilization unit  18 . Access between the two rooms or zones  10 ,  12  can be achieved solely through the sterilization chamber  20 , thereby maintaining one of the zones under sterile conditions or containing securely contaminants within one of the zones. 
         [0028]    An example of seal assembly for the structure of  FIG. 1  can be seen in  FIG. 2 . Shown schematically in this drawing is a sterilization-side flange  30 , which may be formed integrally with the sterilization unit  18  and which extends around the outside perimeter of the unit  18 , both at its sides and also along the top and bottom walls of the unit  18 . Attached to the walls  14 , and equally to a ceiling or wall structure above the sterilization unit  18  and along the floor, there this a frame element  32 . Connected across the flange  30  and frame element  32  is a sealing unit  34 , coupled in this example by a series of bolts  36  disposed at spaced intervals along the sealing unit  34  and fitting into appropriate holes in the flange  30  and frame  32 . All gaps between the walls and the sterilization unit  18  and the adjacent structure or structures, in this example walls  14 , are typically sealed in this manner. The intention of this arrangement, as the person skilled in the art will know, is to ensure that the only path from zone  10  to zone  12  and vice versa is through the sterilization unit  18 . 
         [0029]    A variety of methods are known for testing the integrity of a seal of the type shown in  FIG. 2 . One method commonly used is to pressurise one room  10  relative to the other room  12  and then to check for leaks using sensors in room  10 . However, such testing has shortcomings. One occurs because the pressurisation of, for example, room  10  can only be carried out once all penetrations and apertures in the room  10  have been closed, usually sometime after installation of the sterilization unit  18 . Furthermore, such testing is a “one time” event, carried out during the construction of the building. After commissioning, leakages can result in the escape of pathogens from one room when used for containment or contamination of a sterile room. In particular, the problem with the arrangement shown in  FIG. 2  is that there is no way of determining whether the sealing element  34  provides a secure seal between the two rooms or zones  10 ,  12 . Any leakage from the sealing element  34  cannot generally be detected. 
         [0030]    Referring now to  FIG. 3 , this shows in schematic form a preferred embodiment of the present invention. Disposed between the sterilization unit  18  and the wall  14  is a seal assembly  40  which includes a sterilizer-side flange  42  extending along the sides of the sterilization unit  18  which are disposed in the opening  16  in wall  14 . The seal assembly  14  also includes a wall frame element  44 , which is preferably a metal fabrication installed within the wall aperture where the sterilizer unit  18  is to be located. The metal frame  44  is sealed to the adjacent walls, ceiling and floor, advantageously during building construction. The connection to the walls, floor and ceiling is airtight. 
         [0031]    The embodiment of  FIG. 3  includes a double seal assembly  50 , which includes first and second seal strips or gaskets  52 ,  54  disposed either side of the flange  42  and of a flange  58  of the wall frame  44 , leaving a gap or seal chamber  60  between the first and second gaskets  52 ,  54 . The gaskets  52 ,  54  are fixed to the flange  42  and wall frame  44  by any suitable means, in this example by a series of bolts  56 . Any other coupling or bonding arrangement may be used in place of the bolts  56 . 
         [0032]    The gaskets  52 ,  54  may be made of a rubberised material, for instance ethylenepropylenediene monomer (M-class) rubber (EPDM), or any other suitable sealing material. In another embodiment the gaskets could be made of sheet metal, for instance, with rubberised seals disposed around their peripheries. The gaskets could each be made of the same material but it is not excluded that they may be made of different materials. 
         [0033]    Coupled to the double seal assembly  50 , in this example through an opening or port in one of the gaskets  54 , is a sensor probe  62 , preferably a pressure sensor. When the double seal arrangement  50  is assembled as shown, with the gaskets  52 ,  54  fitted and sealed to the flange  42  and wall frame  44  as shown, the seal chamber  60  between the gaskets  52 ,  54  can be pressurised with a suitable fluid (air may be used as one example). Pressurisation could usefully be by pumping fluid under pressure through the same aperture or port into which the pressure sensor  62  is then fitted, although this could be by any other suitable means or inlet port. 
         [0034]    As long as the gaskets  52 ,  54  provide a proper seal, there should be no drop in pressure of fluid held in the seal chamber  60 . On the other hand, where there is leakage through or around either of the gaskets  52 ,  54 , pressure in the seal chamber  60  will drop, which will be detected by the pressure sensor  62 . In practice, the sensor probe  62  will be coupled to a suitable control or warning unit (not shown) which will generate a warning signal indicative of seal failure. A warning unit could be coupled directly to the assembly or could be a remote monitoring unit, in which case a communication link, wired or wireless, may be provided. 
         [0035]    It will be appreciated that the assembly shown can determine the quality of seal provided by the double seal assembly  50  even before completion of construction of the building, that is before any other apertures or penetrations in the wall  14  or elsewhere in the room  10 / 12  have been sealed. Furthermore, provision of dual seal gaskets  54 ,  56  provides added security in that detection of a leak is likely to occur when just one of the two gaskets  52 ,  54  is defective, thereby without loss of sterilization or containment in the associated room  10 / 12 . 
         [0036]    It is to be understood that the seal chamber  60  may be provided with other detectable fluids, one example being a pure gas, with an appropriate gas sensor able to detect the purity (concentration) of that gas within the seal chamber  60 . Another example provides a coloured fluid. In practice the seal chamber  60  may be filled with any suitable fluid which provides a detectable parameter. In other embodiments the seal chamber  60  may be held under vacuum, with the pressure sensor  62  measuring for loss of vacuum, that is pressure rise, over time. 
         [0037]    Referring now to  FIGS. 4 to 9 , these show features of a practical embodiment of sterilization unit and double seal assembly as taught herein. 
         [0038]      FIG. 4  shows a front elevation view of a sterilization unit  18  having provided therearound a double seal assembly  50  and in particular which extends around the entirety of the perimeter of the sterilization unit  18 , that is at each side, at its top and at its bottom. The double seal assembly  50  extends across the side walls, the ceiling or ceiling wall and to the floor surrounding the sterilization unit  18 .  FIG. 5  shows a side elevation view of the assembly of  FIG. 4 , whereas  FIG. 6  shows a plan view thereof. 
         [0039]    The seal chamber  60  is preferably continuous around the whole of the sterilization unit  18 , as will be apparent from the view of  FIG. 4 . 
         [0040]    Referring now to  FIG. 7 , this shows a cross-sectional view along lines A-A of the double seal assembly  50  of  FIG. 4 . As can be seen, the structure is as depicted schematically in  FIG. 3  and preferably also includes: an inner bolt bar  70 , an inner compression bar  72 , an outer bolt bar  74  and an outer compression bar  76 . These bars  70 - 76  ensure adequate compression of the seal gaskets  52 ,  54  when the bolts  56  are tightened. 
         [0041]      FIG. 8  shows a cross-sectional view of the double seal assembly  50  which extends along the bottom of the sterilization unit  18 , taken along lines B-B. This is the same as the assembly  50  on the other sides of the sterilization unit  18  save for, in this example, the fact that the spacing between the flange  42  of the sterilization unit  18  and the frame element  44  is less (to provide a lower step into the sterilization chamber  20 ). 
         [0042]    Referring now to  FIG. 9 , this shows a cross-sectional view of the double seal assembly  50  across line C-C of  FIG. 4 , which is the same as the remainder of the double seal assembly  50 , save for the provision of a port  80  within the seal gasket  54  which can be used, in this example, both for filing the space  60  with fluid (or vacuuming the space  50  in the case where this is to be held under vacuum) and for holding a suitable sensor probe, such as the temperature probe  62 . 
         [0043]    It will be apparent that although in the preferred embodiment the seal chamber  60  extends around the entirety of the perimeter of the sterilization unit  18 , such that there is a single seal chamber to monitor, in other embodiments there may be provided a plurality of seal chambers around the perimeter of the sterilization unit  18 , each having its own sensor probe and its own port coupling  80 . A single seal chamber is preferred as this is continuous around the entirety of the sterilization chamber  18  and does not leave any zones which cannot be monitored. 
         [0044]    All optional and preferred features and modifications of the described embodiments and dependent claims are usable in all aspects of the invention taught herein. Furthermore, the individual features of the dependent claims, as well as all optional and preferred features and modifications of the described embodiments are combinable and interchangeable with one another. 
         [0045]    The disclosure in the abstract accompanying this application is incorporated herein by reference.