Abstract:
An ampoule opener ( 1 ) has a cylindrical body portion ( 10 ) with a cavity ( 11 ) at an end thereof adapted to receive at least part of the head portion ( 53 ) of an ampoule ( 50 ). A retaining mechanism, such as an resiliently expandable O-ring ( 30 ), is provided at the entrance to the cavity ( 11 ) for retaining the head portion ( 53 ) at least partially within the cavity ( 11 ) after it has been inserted therein. The head portion ( 53 ) may be detached from the remainder of the ampoule ( 50 ) by holding the ampoule ( 50 ) in a first hand with the head portion uppermost, holding the cylindrical body portion ( 10 ) having the head portion ( 53 ) retained therein in the other hand with the thumb uppermost, and causing relative movement between the body portion ( 10 ) and the ampoule ( 50 ). The ampoule opener ( 1 ) includes a plunger ( 20 ) for ejecting the head portion ( 53 ) from the cavity after it has been detached.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This divisional application claims priority under 35 U.S.C. §121 of application Ser. No. 12/306,651 filed on Dec. 24, 2008 which in turn is a national stage application which claims the benefit under 35 U.S.C. §371 of International Application No. PCT/AU2007/000894 filed on Jun. 27, 2007, all of which are entitled APPARATUS AND METHOD FOR OPENING AMPOULES, which in turn takes its priority from Australian Application No. 2006903449 filed on Jun. 27, 2006, and all of whose entire disclosures are incorporated by reference herein. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to apparatus and method for opening ampoules. 
       BACKGROUND 
       [0003]    Ampoules are small containers commonly used for storing medical substances such as liquids intended for hypodermic injection. A typical ampoule has a hollow body for containing a substance, a narrow neck, and a top or head portion which is smaller in volume than the body and which is greater in cross-section than the neck. The head portion and body are normally in fluid communication via a passageway in the neck. 
         [0004]    Removal of the head portion from the body portion by breaking the ampoule at the neck allows access to the contents of the body portion. The contents may then be conveniently extracted from the body portion by insertion of a syringe needle through the passageway in the neck and aspiration of some or all of the contents into the syringe. 
         [0005]    Opening of an ampoule may be achieved by holding the body using the thumb and one or more fingers of one hand, holding the head portion using the thumb and one or more fingers of the other hand so that the thumbs of the user are close together, and snapping the ampoule at the neck. However, opening the ampoule in this way may lead to the user being injured by sharp pieces of glass, especially if the head portion is inadvertently crushed. Other problems with opening of ampoules include regulating finger pressure on the ampoule head, strain to the forearm, especially after repeated operations, and safe disposal of the head. 
         [0006]    In order to avoid injury to a user opening an ampoule, protective covers have been proposed for use during the opening operation. U.S. Pat. No. 4,405,069 discloses an ampoule breaker which has a pair of deformable flexible lip portions (preferably made from a cut-resistant flexible plastic) between which an ampoule head may be placed so that the lip portions serve as a protective barrier between the ampoule head and the gripping digits of the user. While this mitigates the problem of injury, the user must still control and regulate finger pressure upon the head in order to retain the head within the lip portions yet avoid crushing the ampoule head and creating hazardous glass fragments. A user may still suffer from repetitive strain injury if repeated ampoule opening operations are performed. 
         [0007]    It is an aim of this invention to provide an apparatus and method for opening ampoules which overcome or ameliorate one or more of the disadvantages or problems described above, or which at least provide a useful alternative. 
       SUMMARY OF THE INVENTION 
       [0008]    In one broad form, this invention provides an apparatus for opening an ampoule of the type having a detachable head portion, the apparatus comprising: 
         [0009]    a body portion having a cavity adapted to receive at least part of the head portion of the ampoule; and 
         [0010]    retaining means on the body portion for retaining the head portion at least partially within the cavity after it has been inserted therein; 
         [0011]    whereby the head portion may be detached from the remainder of the ampoule by relative movement between the body portion having the head portion retained at least partially therein and the remainder of the ampoule. 
         [0012]    With the present invention, the user need not manually retain the head portion in the body portion; it is held therein by the retaining means while the head portion is detached from the remainder of the ampoule. Moreover, it is held therein by the retaining means until deliberately ejected as described below. After ejection of a detached ampoule head, the apparatus may be re-used. 
         [0013]    In one embodiment, the retaining means has an expandable opening whose widest dimension at rest is less than the widest portion of the head portion. The retaining means is mounted on the body portion such that at least the widest portion of the head portion passes through the opening when the head portion is inserted into the cavity. The retaining means is expanded by the passage of the head portion therethrough and then automatically constricts behind the widest portion of the head portion to releasably retain the head portion at least partially in the cavity. 
         [0014]    The retaining means is a preferably a resiliently expandable annular device such as an O-ring of elastomeric material. The elasticity of the O-ring allows it to be used with differently sized ampoule heads. 
         [0015]    The retaining means may take other forms such as a four-lobed O-ring (of the type sometimes known as a quad ring) or a resiliently flexible washer. 
         [0016]    The O-ring is suitably located at least partially in an annular groove adjacent the entrance of the cavity in the body portion. 
         [0017]    Preferably, the ampoule opening apparatus of this invention further comprises a mechanism for ejecting the head portion of the ampoule from the cavity. This ejecting mechanism may suitably be an elongate member slidable within the body portion. The elongate member is manually operable to contact the head portion of the ampoule retained within the cavity and eject it from the cavity against the action of the retaining means. 
         [0018]    More preferably, the elongate member is resiliently biased towards the entrance of the cavity in the body portion by a helical (coil) spring. The bias force is suitably a gentle force. 
         [0019]    The elongate member preferably has an axis which is generally aligned with the centre of the entrance of the cavity, and has a concave portion at its end adapted to contact the head portion of the ampoule. In this manner, it retains the head portion centrally relative to the entrance of the cavity after it has been detached. This assists in ejecting the detached head portion from the cavity against the action of the retaining means. 
         [0020]    The above described arrangement also provides ideal pressure points for the head portion to be detached easily. When the ampoule is held vertical and the body portion is levered forward to snap the head portion off, pressure occurs at the lowest point of the head portion on one side, and at the highest point of the head portion on the opposite side. This results in the ideal lever action with and less force being required. 
         [0021]    Typically, the body portion of the ampoule opening apparatus is generally of elongate cylindrical shape, with the cavity at an end thereof. This enables the body portion to be used in a lever action, with the user positioning his/her hand with the thumb at the top, and the little finger towards the cavity end. This, in turn, results in less stress on the wrist as it used in a more ergonomical manner than that required for known ampoule openers. 
         [0022]    Preferably the body portion is at least 3 cm in length, and more preferably at least 8 cm in length. 
         [0023]    The external surface of the body portion may be provided with a flat portion extending axially along its length, to prevent the body portion from freely rolling about its axis. 
         [0024]    The body portion may be provided with a cavity at each axial end thereof, the cavity at one end being sized differently from the cavity at the other end. 
         [0025]    In another broad form, this invention provides a method of opening an ampoule of the type having a detachable head portion, the method comprising: 
         [0026]    holding the ampoule in a first hand with the head portion uppermost, 
         [0027]    holding in the other hand with the thumb uppermost, an ampoule opener having a cavity at its lower end adapted to receive the head portion of the ampoule, 
         [0028]    inserting the head portion of the ampoule at least partially into the cavity, the ampoule opener having retaining means for retaining the head portion at least partially within the cavity after it has been inserted therein, and 
         [0029]    causing relative movement of the ampoule opener having the head portion retained therein and the remainder of the ampoule to thereby detach the head portion from the remainder of the ampoule. 
         [0030]    Preferably, the ampoule opener includes an elongate member slidable therein, and the method further comprises the step of manually operating the elongate member to contact the head portion of the ampoule retained within the cavity and eject it from cavity against the action of the retaining means. The elongate member is typically operated by depressing its upper end with the thumb of the other hand. 
         [0031]    In order that the invention may be more readily understood and put into practice, one or more embodiments thereof will now be described, by way of example only, with reference to the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]      FIG. 1  is a schematic vertical cross-sectional view of an embodiment of an apparatus for opening ampoules; 
           [0033]      FIG. 2(   a ) is a vertical cross-section of the body of the apparatus of  FIG. 1 ; 
           [0034]      FIG. 2(   b ) is a vertical cross-section of a release mechanism element of the apparatus of  FIG. 1 ; 
           [0035]      FIG. 3(   a ) shows an ampoule about to be inserted into the apparatus of  FIG. 1 ; 
           [0036]      FIG. 3(   b ) shows the ampoule head partially inserted into the apparatus; 
           [0037]      FIG. 3(   c ) shows the ampoule head inserted into the apparatus; 
           [0038]      FIG. 4(   a ) shows the apparatus with inserted ampoule immediately prior to opening of the ampoule; 
           [0039]      FIG. 4(   b ) shows the apparatus and ampoule immediately after opening of the ampoule; 
           [0040]      FIG. 5(   a ) shows the detached ampoule head retained in the apparatus; 
           [0041]      FIG. 5(   b ) shows the detached ampoule head immediately after release/ejection from the apparatus; 
           [0042]      FIGS. 6(   a ) and  6 ( b ) correspond generally to  FIGS. 4(   a ) and  4 ( b ) but illustrate schematically first and second possible positions of a user&#39;s hands during opening of the ampoule; and 
           [0043]      FIGS. 7(   a ),  7 ( b ) and  7 ( c ) and  FIG. 7(   d ) are schematic vertical cross-sectional views of alternative embodiments of an apparatus for opening ampoules. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0044]    With reference to  FIG. 1  an apparatus generally designated  1 , for opening ampoules, comprises a body portion provided, in this embodiment, by a generally cylindrical body  10  with a receiving space, in this embodiment in the form of a cavity  11 , at a first end thereof and a release mechanism which in this embodiment is provided by a plunger  20 . 
         [0045]    The apparatus  1  further comprises at least one retaining member which in this embodiment is in the form of an O-ring  30 , provided generally at the opening of the cavity  11 , that is, at the first end of the generally cylindrical body  10 . The plunger  20  is retained in a central bore  12  of the generally cylindrical body  10 , and is biased towards the first end of the generally cylindrical body  10 , in this embodiment by a resilient member in the form of a helical spring  40 . 
         [0046]    Referring now especially to  FIG. 2(   a ) the generally cylindrical body  10  is shown in vertical cross-section. The bore  12  is generally cylindrical and extends between the cavity  11  and a second end of the generally cylindrical body  10 . Spaced apart from the cavity  11  the bore narrows to provide an annular shoulder  13  with a surface facing generally towards the first end of the generally cylindrical body  10  and a narrowed bore section  12   a,  which extends between the shoulder  13  and the second end of the generally cylindrical body  10 . 
         [0047]    The cavity  11  is open at the first end of the generally cylindrical body  10 . Close to the first end of the generally cylindrical body  10  an annular groove  14  is provided in the internal wall of the cavity to receive and retain the O-ring  30 . It will be appreciated that the internal diameter of the O-ring  30 , when unstretched, is substantially smaller than the diameter of the opening of the cavity  11 , so that it somewhat occludes the cavity. The external diameter of the O-ring  30 , when unstretched, is considerably smaller than the diameter of the annular groove  14 . The O-ring is sufficiently elastic that it can be stretched considerably by passage of an ampoule head therethrough, and the size of the groove  14  accommodates such stretching. 
         [0048]    The generally cylindrical body  10  is, in this embodiment, also provided with an external flange or collar  15  at its first end. This may protect a user&#39;s hand from contact with the broken upper surface of an ampoule body and also provides a convenient region of increased width, allowing the apparatus to be stored in a rack (in an inverted orientation) which has an aperture corresponding to the cross-sectional shape of the part of the generally cylindrical body  10  which is not widened. As can be seen in  FIG. 1 , the generally cylindrical body  10  is also provided with a marking or indicium  16 , close to the collar  15 . 
         [0049]    Use of the indicium will be described below. 
         [0050]    Referring now to  FIG. 2(   b ), the plunger  20  comprises an elongate generally cylindrical stem  21 , at the, first, lower end of which is a coaxial cylindrical ampoule head engaging portion  23  with radius greater than the radius of the elongate generally cylindrical stem  21 . At a second, upper end of the stem  21  is an end portion  22  thereof, which may be regarded as an operating portion, which in use is operated by the thumb of a user. 
         [0051]    The ampoule head engaging portion is provided with an upwardly facing shoulder  24  where it joins the stem  21  and is further provided with a concave region  25  at an underside thereof. The concave region  25  is shaped to receive and engage part of an ampoule head. 
         [0052]    As shown in  FIG. 1 , when assembled the apparatus is arranged with the plunger  20  substantially within the cylindrical body  10 . The spring  40  is fitted around part of the stem  21  and located substantially in the bore  12 . The spring is somewhat compressed between the shoulder  13  of the cylindrical body  10  and the shoulder  24  of the plunger and thus gently biases the plunger  20  towards the first end of the cylindrical body  10 . However the ampoule-head engaging portion  23  of the plunger  20  is prevented from existing the cavity  11  by the O-ring  30  (or other retaining member). 
         [0053]      FIGS. 3(   a ),  3 ( b ) and  3 ( c ) illustrate insertion of part of an ampoule  50  into the apparatus  1 . The ampoule  50 , has a body  51 , a neck  52  and a head  53 . The ampoule  50  is provided with a scored or otherwise weakened region  54  on its neck  52 , to facilitate opening, and with an indicium  55 , typically in the form of a dot of paint or pigment, to indicate the angular position of the weakened region  54 . 
         [0054]      FIG. 3(   a ) shows the ampoule  50  adjacent the apparatus  1 . The plunger  20  is gently biased towards the first end of the cylindrical body  10  (and thus also towards the O-ring  30 ) and is in contact with the O-ring  30 . The O-ring is in substantially its equilibrium, unstretched, state. The indicium  16  on the body is aligned with the indicium  54  on the ampoule, by a user, so that even with the ampoule head  53  within the apparatus  1  the position of the weakened region  54  will be evident to a user, assisting application of an opening force in an appropriate direction to provide a clean opening operation of the ampoule  50 . 
         [0055]      FIG. 3(   b ) shows the ampoule  50  and apparatus  1  with the ampoule head  53  being inserted into the cavity  11 . The O-ring  30  is stretched by passage of the widest part of the ampoule head  53  therethrough. The ampoule head  53  engages the concave region  25  of the ampoule head engaging portion  23 . The plunger  20  is moved towards the second end of the cylindrical body  10 , and away from the first end of the cylindrical body  10  by the force applied by the ampoule head  53 . The spring  40  is partially compressed. 
         [0056]      FIG. 3(   c ) shows the situation with the ampoule head  53  inserted into the cavity  11 . The O-ring  30  has contacted to its equilibrium (or close to equilibrium) size and substantially surrounds the neck  52  of the ampoule  50 . A lower part of the ampoule head is engaged by the O-ring  30 , and the resilience of the O-ring  30  offers resistance which prevents the ampoule head  53  from exiting the cavity  11 . The plunger  20 , being biased by the spring  40  is kept in contact with the ampoule head  52 , and also provides a gentle force keeping the bottom part of the ampoule head  52  in contact with the O-ring  30 . The bias force is indicated by the arrow BF in  FIG. 3(   c ). 
         [0057]      FIGS. 4(   a ) and  4 ( b ) show schematically a preferred way of operating the apparatus  1  in order to break or open the ampoule  50 . As positioned in  FIG. 4(   a ) the ampoule body  51  is preferably held substantially upright in a first (typically the left) hand of a user and the apparatus  1  held in the other (typically the right) hand of a user, as will be further described below with reference to  FIG. 6 . The apparatus  1  is then moved relative to the ampoule body  51  in order to apply an opening force to the ampoule head and break the ampoule  50  at its neck  52 . More specifically, in the illustrated embodiment an engagement region  26  of the concave region  25  of the plunger  20  engages an upper part of the ampoule head  53 , and an engagement region  17  of the internal wall of the cavity  11  engages a lower part of the ampoule head  53 . The forces are preferably applied as indicated by the arrows in  FIGS. 4(   a ) and  4 ( b ), so that a tensile force is applied to the weakened region  54  of the ampoule neck  52 . The forces are easily applied manually by a user who is holding the ampoule body  52 , substantially vertically orientated, in a first (eg a left) hand, with the navicular (or thumb) side of the first hand upwards, and is holding the apparatus  1 , substantially vertically orientated, in the other, second (eg a right) hand, with the navicular (or thumb) side of the second hand upwards. The opening operation will then correspond to a natural action, avoiding undue strain or discomfort, and allowing the ampoule to be retained in an upright position during opening, reducing the risk of spilling the ampoule contents. 
         [0058]    As shown in  FIG. 4(   b ), after the ampoule is opened the ampoule head  53  is retained in the cavity  11 , held gently between the biased plunger  20  and the O-ring  30 , until a user wishes to eject the ampoule head  53 . Thus the ampoule head  53  is effectively automatically retained in the apparatus  1  until deliberately ejected. 
         [0059]      FIGS. 5(   a ) and  5 ( b ) show schematically a preferred way of operating the apparatus  1  in order to eject the ampoule head, for example into a sharps safe container  60 . As shown in  FIG. 5(   a ) the plunger is forced gently towards the first end of the cylindrical body  10 . This force can be easily applied by the thumb of a user operating upon the second end of the stem  21 , especially given the hand positioning described above, which will be further described with reference to  FIGS. 6(   a ) and ( 6   b ). Forcing the plunger  20  towards the O-ring  30  forces the lower part of the ampoule head against the O-ring  30  with considerably more force than was applied by the spring  40 . This deforms or stretches the O-ring  30  enough to allow passage of the ampoule head therethrough. As shown in  FIG. 5(   b ) the ampoule head can easily, deliberately and predictably be ejected into a suitable sharps safe container  60 . Once the ampoule head has been ejected the plunger  20  rests, in its equilibrium position, against the O-ring  30  (which will again be unstretched). Easy, deliberate and predictable ejection of the ampoule head into a sharps safe container is an important safety feature of preferred embodiments. 
         [0060]    The preferred hand positions of a user, during operation of the apparatus  1  are illustrated schematically in  FIGS. 6(   a ) and ( 6   b ). As shown in  FIG. 6(   a ) a user is holding the ampoule  53 , substantially vertically orientated, in a first, left, hand with the navicular (or thumb) side of the first hand upwards. Thus the thumb  61  and index finger  62  of the first hand are towards the top of the ampoule  53 , and the middle finger  63 , ring finger  64  and little finger  65  are successively lower. (The ring finger  64  and little finger  65  are typically below the ampoule and not engaged with the ampoule and are therefore shown in broken lines.) The user is holding the apparatus  1 , substantially vertically orientated, in a second, right, hand with the navicular (or thumb) side of the second hand upwards. Thus the thumb  71  and index finger  72  of the second hand are towards the top of the apparatus  1 , and the middle finger  73 , ring finger  74  and little finger  75  are successively lower. It should be appreciated that although the fingertips only are shown in order to indicate the hand orientations, the user may use the whole hands in holding the apparatus (and/or ampoule) and holding these objects with the fingertips only is not necessarily recommended or desirable. 
         [0061]    The thumb  71  of the second hand may be placed on the plunger  20  during the opening operation if desired, as illustrated in  FIG. 6(   b ) although in this case care must be taken that the force applied by the thumb doesn&#39;t inadvertently move the plunger axially. However, it will be appreciated that the thumb can be easily moved to the plunger  20  after opening the ampoule  50  to allow easy ejection of the ampoule head without requiring significant moment of the hand or fingers of the hand holding the apparatus and without requiring an unnatural or uncomfortable hand position to be used. 
         [0062]    As illustrated in  FIGS. 6(   a ) and  6 ( b ) the user may be considered to be to the right of the apparatus  1 , and holding the apparatus and ampoule directly and centrally in front of him. The right hand of the user would be behind the apparatus  1  as viewed, with the thumb  71  and fingers  72 ,  73 ,  74 ,  75  projecting towards the viewer (or out of the paper). The left hand of the user would be in front of the ampoule as viewed, with the thumb  61  and fingers  62 ,  63 ,  64 ,  65  projecting away from the viewer (or into of the paper). 
         [0063]    It will be appreciated that the illustrated hand orientation is the natural orientation for holding a vertically orientated elongate object in each hand, and results in natural arm position. In contrast, holding the upper hand with the thumb or navicular side of the hand downwards (as is required in ampoule opening procedures in which the ampoule body is held vertical in one hand and the ampoule head is held between the thumb and first finger of the other hand) results in an uncomfortable arm position with the elbow raised. Use of some prior art ampoule opening devices has required the ampoule to be orientated other than substantially vertically in order for a user to attain a less uncomfortable position, resulting in an increased likelihood of spilling the ampoule contents upon opening. 
         [0064]    It will be appreciated that it is desirable to provide ampoule head retaining member(s), such as the O-ring (although different arrangements could be used) operation of which to retain an ampoule head does not require a gripping pressure to be applied to the ampoule from outside the apparatus in order to retain the ampoule head during the opening operation. This eliminates the need to position the thumb and index finger close to, and on either side of, the ampoule head, and allows the part of the apparatus where the ampoule head is retained to be held by the relatively weak ulna side of the hand. Thus the apparatus can be held by a hand in the natural and comfortable “thumb up” position. Using an apparatus body that is approximately as long as the width of a user&#39;s hand provides ample leverage, allows a user&#39;s hand to fit comfortably around the apparatus body, and allows the ampoule neck to be close to, and between, both hands during the opening operation while retaining easy access to the part of the plunger (ejecting mechanism) which extends from the second end of the body. For this reason the body of the apparatus is preferably between about 5 cm and about 15 cm in length, and most preferably between about 8 cm and 12 cm in length. 
         [0065]    A further benefit of the preferred embodiment is that because the O-ring has considerable elasticity a relatively wide range of ampoule head diameters can be admitted and retained in the apparatus. This allows a wide range of ampoule sizes to be opened using a single device (rather than the device being limited to only a very limited range of ampoule sizes, as might have been expected). 
         [0066]    It will be appreciated that many variations are possible. For example the cavity could be shaped so that a part of the cavity wall contacts and operates on the upper part of the ampoule head during the opening operation. The apparatus need not necessarily be generally cylindrical or generally symmetrical, although these characteristics are currently considered desirable in a preferred embodiment. In a preferred embodiment the body is made from metal. The body may be cast or lathe formed steel or aluminum. In alternative embodiments the body may be moulded from a suitable plastic. 
         [0067]    One alternative embodiment  100  is illustrated in  FIGS. 7(   a ),  7 ( b ) and  7 ( c ). The apparatus  100  has a body  110  defining a smaller cavity  111 , at one end, with an associated smaller retaining member  130 , for accommodating smaller ampoule heads  150 , and a larger cavity  112  at the other end, with an associated larger retaining member  131  for accommodating larger ampoule heads  151 . This allows a single apparatus  100  to be used on a larger range of ampoule sizes. Moveable within the body  110  is an ejection member  120 . The ejection member  120  can be operated, by contact of a user&#39;s thumb with an operating portion  121 , in order to eject ampoule heads from the larger cavity  112  (as shown in  FIG. 7(   a )) or the smaller cavity  111  (as shown in FIG. ( c )). The operating portion  121  extends generally perpendicular to the axis of the ejection member  120  and projects through a slot  113  in an axially central part of the body  110 .  FIG. 7(   b ) illustrates an intermediate position of the ejection member  120 . 
         [0068]    A further variation, in the form of an apparatus  200  is illustrated in  FIG. 7(   d ). This embodiment is similar to the embodiment  100 , except that rather than having a single ejection member, first and second ejection members  220   a,    220   b  are provided, each biased towards a respective retaining member  230 ,  231 . This allows more predictable engagement with an ampoule head, and more predictable retention of the ampoule head between the ejection member and the retaining member prior to ejection of the ampoule head. In the illustrated embodiment the bias is provided by a resilient member  240 , such as a spring, provided between the second ejection members  220   a,    220   b.  However, any suitable alternative mechanism may be used. 
         [0069]    It is to be understood that the terminology employed above is for the purpose of description and should not be regarded as limiting. 
         [0070]    The foregoing embodiments are intended to be illustrative of the invention, and it is to be understood that the scope of the invention is not to be limited to the exact construction and operation described and illustrated, but only by the following claims. 
         [0071]    In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word “comprise” or variations such as “comprises” or “comprising” is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. 
         [0072]    It is to be clearly understood that although prior art publication(s) are referred to herein, this reference does not constitute an admission that any of these documents forms part of the common general knowledge in the art in Australia or in any other country.