Abstract:
Methods and apparatus for cleaning and disinfecting items are generally discussed herein with particular discussions extended to controlled delayed release of agents for the cleaning of contact lenses.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This is a regular utility application of provisional application Ser. No. 61/163,207 filed Mar. 25, 2009, the contents of which are expressly incorporated herein by reference. 
     
    
     FIELD OF ART 
       [0002]    Methods and apparatus for cleaning and disinfecting articles for use are generally discussed herein with particular discussion extended to timely controlled delay release of agents involved in the cleaning and disinfecting of contact lenses. 
       BACKGROUND 
       [0003]    Cleaning and disinfecting articles for use is a medical, hygienic, and sanitary practice often required and/or utilized to minimize the risk of microbial contamination or infection. A number of non-chemical as well as chemical means to bring about the cleaning and disinfecting of items are known. Non-chemical examples include heat, ultra-violet light, microwaves, and mechanical force, etc. Chemical examples include various acids and bases, aldehydes, as well as ozone, hydrogen peroxide, chlorine dioxide and various biguanides, etc. 
         [0004]    Among the known chemical cleaners and disinfectants, hydrogen peroxide is often preferred due to its proven relative safety, the green chemistry of the byproducts. As such, hydrogen peroxide will be used herein as an exemplary chemical disinfectant. Disinfectants such as hydrogen peroxide are potent cleaners; however, they can cause irritation to the skin, the eyes, etc. Therefore, the solution needs to be neutralized after cleaning and disinfecting to minimize the irritating effect. However, if the solution is neutralized too early, its cleaning effect will diminish before the articles are appropriately cleaned. Thus, it is generally desirable to maintain the potency of the cleaning and disinfecting agent(s) over a prolonged period of time and to neutralize the disinfectants only after a desired time. This is especially true in the cleaning and disinfecting of contact lenses where it is desirable to maintain hydrogen peroxide at the initial level, over a sustained period of time so as to allow the cleaning of more resistant debris and the killing of certain more resistant microbes. As such, contact lenses will be used as an exemplary item to be disinfected. Moreover, in some instances, such as with contact lenses, it is further desirable to add the neutralizing agent concurrently with the disinfecting agent, but to delay their interactions by some means, such as by coatings on tablets, or rate controlled constructs, until some desirable benefit is obtained. 
         [0005]    One deficiency, among others, of tablet mediated delayed release systems is that the tablet coating material(s) become tacky during dissolution. This compromises the safe and effective use of such systems since, if the container is not maintained upright until tablet dissolution is complete, the tablet can stick to the bottom of the container where it may not be in liquid solution and consequently does not bring about neutralization. Another deficiency of such systems is that after the neutralization, the agent(s) comprising the tablet remain dissolved in the neutralized solution and are available to support microbe growth. Yet another deficiency of such systems is that consistent and reproducible coating is in practice difficult to achieve and such systems are known to be highly variable in delayed release rates. A further deficiency of such systems is that it has been found necessary to include an indicator into the tablets to indicate that the tablet has indeed been added to bring about the neutralization. Again a further deficiency of such systems is that optimal tonicity in the final neutralized solution is, in practice, difficult to achieve since it requires the user to use an exact amount of liquid, not doing so results in variable tonicities, which can irritate the eye upon lens installation. A yet further deficiency of such systems is residue formed from incomplete dissolution of tablet components or non-homogeneous regions in the liquid created by density or other such differences between tablet components and bulk liquid. In view of the foregoing problems, alternative delayed release systems have been proposed and pursued. 
         [0006]    Another alternative delayed release system uses mechanical constructs or apparatus. In addition to the above-mentioned tablet mediated release deficiencies, controlled release apparatus or constructs, while in theory may be made to work, in practice have proved technically difficult to be consistently functional. 
         [0007]    Other alternative systems, while not delayed systems, rely on insoluble solid catalytic neutralizing agents, such as metals, metals deposited onto supports, or catalase bonded to supports, to neutralize the disinfectant. 
         [0008]    A deficiency of both tablet based systems and alternate construct systems is that they are particular to orientation for effectively venting of the generated gas. As the vast majority of these systems use hydrogen peroxide as the disinfectant and its neutralization generates a substantial quantity of gaseous oxygen, such systems require ventilation of the gas from the contact lens container to avoid cracking, breaking, or shattering of the container. One deficiency of the existing venting systems is that they allow liquid to leak under normally anticipated conditions of usage. Another deficiency of both tablet based systems and alternate construct systems is that they are particular to orientation to function effectively. 
         [0009]    Thus, there remains a need for more robust controlled delayed systems for cleaning and disinfecting items. 
       SUMMARY 
       [0010]    The present invention meets the aforementioned needs by providing methods and apparatus for controlled delayed release of neutralizing agents for the cleaning and disinfecting of articles for use, such as contact lenses. By sizing the apparatus appropriately, other articles such as scalpels, scissors, and other medical instruments may be cleaned and disinfected. 
         [0011]    The present invention may be practiced by providing an apparatus adapted to delay the release of a primary agent, the apparatus comprising: a first chamber finable with a disinfectant agent and comprising a housing comprising a side wall, a top wall, a projection extending away from an internal housing wall and having a hollow bore, a secondary agent disposed, at least in part, in the hollow bore of the projection; wherein the primary agent being removably secured to the projection and covers an opening in the internal cap wall; a second chamber comprising a housing of larger volume than the first chamber having multiple vent holes and in contact with the projection; wherein the primary agent is displaceable from the projection by pressure generated in the first chamber after a time period measured from when the housing of the first chamber is coupled to the housing of the second chamber. 
         [0012]    The present invention may also be practiced by providing an apparatus for the timely controllable cleaning and disinfecting of articles for use, the apparatus comprising: a first chamber having a first volume; a second chamber having a second volume; a seal isolating the first chamber from the second chamber; a stem projecting from the first chamber into the second chamber; and wherein the seal is severable by pressure build up in the first chamber; and wherein a channel is created and linking the first chamber with the second chamber when the seal is severed. 
         [0013]    In yet another aspect of the present invention, there is provided a method for delaying the release of a primary agent during the cleaning and disinfecting of articles for use. The method comprising: adding a disinfectant agent into a container to a filled level; placing an article to be disinfected into a holder; placing a cap over the container and so that at least a portion of the holder is below the filled level of the disinfectant agent; maintaining a neutralizing agent below the cap but above the filled level of the disinfecting agent; moving the neutralizing agent into the disinfectant agent after a period of time in which pressure build up inside the cap and container is greater than atmospheric pressure. 
         [0014]    Other aspects and variations of the apparatus and methods summarized above are also contemplated and will be more fully understood when considered with respect to the following disclosure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]    These and other features and advantages of the present invention will become appreciated as the same become better understood with reference to the specification, claims and appended drawings wherein: 
           [0016]      FIG. 1  is an exemplary exploded perspective view of a cleaning/disinfecting assembly provided in accordance with aspects of the present invention; 
           [0017]      FIG. 2  is an isometric view of the cleaning/disinfecting assembly of  FIG. 1  in an assembled state; 
           [0018]      FIG. 3  is an exemplary top view of the assembly of  FIG. 2 ; 
           [0019]      FIG. 4  is an illustration of a cross-sectional side view of the assembly of  FIG. 3  taken along line A-A; and 
           [0020]      FIG. 5  is a pressure versus volume of Hydrogen peroxide versus headspace within the assembly graph. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    The detailed description set forth below in connection with the appended drawings is intended as a description of the presently preferred embodiments of the apparatus and method provided in accordance with aspects of the present invention and is not intended to represent the only forms in which the present invention may be constructed or utilized. The description sets forth the features and the steps for constructing and using the apparatus of the present invention in connection with the illustrated embodiments. It is to be understood, however, that the same or equivalent functions and structures may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention. As denoted elsewhere herein, like element numbers are intended to indicate like or similar elements or features. 
         [0022]      FIG. 1  shows an embodiment of a cleaning/disinfecting assembly  10  provided in accordance with the present invention. Although phrased as a “cleaning/disinfecting” assembly, the assembly is understood to be capable of providing one or the other or both functions. In one exemplary embodiment, the cleaning/disinfecting assembly  10  comprises a container or base  1  and a cap  11 . The container or base  1  can be made from any suitable natural, synthetic, or laminate materials and most preferably from a transparent or translucent material. In one embodiment, the container  1  comprises a bottom wall  2  and a side wall  3  defining a container cavity  1   a  having an opening  7 . Although shown with a single cylindrical side wall  3 , the container may take on any appropriate shape and configuration and have distinct wall panels, such as a square container with four side wall panels. 
         [0023]    In one embodiment, the bottom wall  2  comprises an anchor  2   b  and vents  5  that serve to relieve pressure build up inside the container  1  during the disinfection process, as further described below. The anchor  2   b  may embody an integrated cylinder having a tapered internal bore for engaging a stem, as further discussed below. As shown, the vents  5  are hollow bosses having hydrophobic filters that can be made from a number of suitable materials well known to one skilled in the art, such as super hydrophobic polyvinyldiflouride (PVDF). The vents allow gas to escape but not liquid. Other vents are contemplated, such as various other relief valves. The side wall  3  comprises a peripheral flange or mating rim  6 , and comprises external threads  9 . The peripheral flange  6  and external threads  9  are adapted to receive the cap  11  to seal the container  1 , as will be further described in connection with the cap  11 . The side wall  3  further comprises a fill line or demarcation  8  to indicate the level to which a disinfectant agent should be filled during use. 
         [0024]    Within the container cavity  1   a , an internal wall  4  having an internal opening  10  for an internal cavity  1   b  is provided. The internal opening  10  is recessed from the opening  7  located at the peripheral flange  6  and the internal cavity  1   b  is a subset of cavity  1   a , located generally below the peripheral flange. 
         [0025]    As shown in  FIGS. 2 and 4 , the closing of the cap  11  onto the container  1  divides the cleaning/disinfecting apparatus according to aspect of the present invention into 2 chambers, for instance a lower or first chamber  33  and an upper or second chamber  15 . The designations first and second chambers serve to distinct the two chambers from one another but otherwise do not have structural limitations. The first chamber  33  may be referred to also as a disinfecting chamber and the second chamber  15  may be referred to as a pressure chamber. The two chambers are in communication with each other partly via vent holes, for example vent hole  19 . Although  FIGS. 2 and 4  show the two chambers stacked vertically one on top of the other, it should be understood that the other configurations could also be contemplated without departing from the scope of the invention. For instance, the chambers can be connected horizontally or in alternative configurations. 
         [0026]    The cap  11  comprises a cap top wall  12 , a cap side wall  13  and a cap bottom wall  14 . As shown in  FIGS. 2 and 4 , the cap bottom wall  14 , an internal cap side wall  13   a  and an internal cap top wall  12   a  define the pressure chamber  15 . The cap side wall  13  comprises internal threads  17  configured to engage with the external threads  9  from the container  1  to mediate the sealing of the cap  11  with the container  1 . 
         [0027]    According to one embodiment of the invention, a first chamber or lower chamber  33  is defined by the cap bottom wall  14 , the internal side wall  4  and the bottom wall  2 . Within the first or lower chamber  33 , lens baskets or holders  32  are attached to the bottom wall  14  via attachment means  21 , which may comprise any suitable mechanical attachment fixtures such as pin, detents, etc. A hollow tube, projection, or stem  18  comprising a bore in fluid communication with the upper chamber extends distally from the bottom wall  14  and comprises an opening  23 . The stem  18  is configured to project into and engage with the anchor  2   b  located at the bottom wall  2  of the container  1  upon sealing of the container  2  by the cap  11 . The stem has a tapered tip configured to mate with the tapered internal bore of the anchor in a tapered fit arrangement. 
         [0028]    A first neutralizing agent, such as a primary neutralizing component  25 , is attached to the bottom wall  14  by sliding it up around the outside of the stem  18  and using friction, detent engagement, or a temporary fastener to hold in place. In one embodiment, the primary neutralizing component  25  comprises a support material  26  covered with a platinum coating  27 , and one or more male interference closure seat  28  for engaging with female interference seat  20  located on the stem  18  to secure the primary neutralizing component  25  in place. The reverse detent arrangement between the neutralizing component  25  and the cap is also contemplated. The component  25  resembles a doughnut and has annular recess around the external periphery to serve as a female detent. As such, the component  25  has an outside diameter and an inside diameter. 
         [0029]    A second agent, such as a secondary neutralizing component  29 , is incorporated and held within a cavity  18   a  defined by the hollow interior of the stem  18 . The secondary component  29  may comprise a support material  30  covered with a platinum coating  31  and having a male interference closure seat  31  for attaching to either the stem and/or the cap. A color indicator  24  extends proximally from an opening  19  on the bottom wall  14  and is in communication with the cavity  18   a  for providing user feedback information, as further discussed below. 
         [0030]    Vents  19 ,  22  are provided on the bottom wall  14  of the cap to relieve pressure build up inside the first chamber  15  during the disinfection process, as further described below. Upper vents  16  are also provided but are provided with tubes that are connected to the lower cap wall  14 . The vents  16  comprise cylindrical bosses that are each covered with hydrophobic material such as super hydrophobic polyvinyldiflouride (PVDF). Pressure build up in the lower chamber  33  can thus vent through the upper vents  16 , through the tubes, and the lower vents  5  at the bottom of the container. The vent hole or opening  22  at the bottom cap wall is provided at a corner of the bottom wall  14  to allow gas release into the lower chamber to allow hydrogen peroxide to be captured in the stem upon closure of the cap onto the container, as will be further described. Vent  19  is configured as a relief valve by allowing pressure build up in the upper chamber to push against the primary neutralizing agent  25  to separate the same from the cap, as further discussed below. By providing vent holes  16  on the cap and vent holes  5  on the lower container, the apparatus can operate, i.e., can vent, whether it is held in the standing position shown in  FIG. 2 , flipped upside down, or tipped on its side. 
         [0031]    Mode of Operation: 
         [0032]    As shown in  FIG. 4 , in one exemplary embodiment, to use the cleaning/disinfecting assembly in accordance with aspects of the present invention, a cleaning/disinfecting agent, for example, hydrogen peroxide solution is placed into container  1 , up to the fill line or demarcation line  8 . Item(s) to be disinfected, for example contact lenses, are placed into holder(s) or basket(s)  32 , which is well known in the prior art and has a plurality of strainer holes. 
         [0033]    The cap  11  is then sealed to the container  1  by threading the cap  11  internal threads  17  onto the external threads  9  of the container. During the sealing process, liquid enters the hollow stem  18  through the opening  23  at the stern. This is possible because the displacement volume of gas in the pressure chamber  15  is expelled through the opening  22  near the peripheral edge of the lower cap wall  14 . Also during the sealing process, the exterior of the distal end wall of stem  18  forms an air tight seal with internal wall  4 , more particularly with the anchor  2   b  located on the bottom wall of the container. 
         [0034]      FIG. 1  shows a cut-out on only one edge of the lower cap wall  14  with multiple cut-outs contemplated to provide additional vent openings. Upon full closure, opening  22  is air-tight sealed by the mating of the distal portion of the cap  11 , i.e., the bottom wall  14 , with the mating rim or peripheral flange  6  of the container. As such, the upper pressure chamber  15  is defined by the top wall  12 , the side wall  13 , and the bottom wall  14  (including the hollow of stem  18 ). The upper chamber is also defined by the two mating air tight seals formed upon closure by the distal end of stem  18  to the anchor at the internal wall  4  and the bottom wall  14  against the mating rim  6 . 
         [0035]    Upon closure of the cap to the container, the quantity of liquid hydrogen peroxide isolated within the hollow space of the stem  18  comes into communication with the secondary neutralizing component  29 . The reaction of the hydrogen peroxide with the secondary neutralizing component  29  results in gas formation. Factors, among others, such as the area of the interface therebetween, the amount of hydrogen peroxide trapped by the stem, the volume of the pressure chamber  15 , and the activity of coating  31  can contribute to the rate of gas formation. The rate can be controlled by manipulating these factors so that the pressure chamber  15  is pressurized to a desired pressure point after a desired set time frame. As it is formed, the pressure applies a force onto the engagement between the detents  20  and  28  which secures the primary neutralizing component  25  to the bottom wall  14 . After a given time, at which point sufficient force has been achieved, the neutralizing component  25  is dislodged from its attachment to the bottom wall  14  and drops into the disinfecting chamber  33 , which then opens a seal or channel  19  located between the two chambers that was previously sealed by the neutralizing agent  25 . The detachment can also be regulated by the extent of physical engagement, such as depth of engagement and strength of material used, between the two detents  20 ,  28 . The physical contact of the neutralizing component  25  with the liquid hydrogen peroxide initiates the neutralization reaction within the disinfecting chamber  33 , which results in the formation of gas bubbles. 
         [0036]    Graph  1  shows the relationship between the secondary neutralizing component  29  for a given volume of 3% hydrogen peroxide and for a given volume of head space in the upper pressure chamber  15 . The information allows a skilled artisan to select the force or pressure necessary for a given head space to separate the primary neutralizing component  25  from the cap so that it falls into the bath of hydrogen peroxide to neutralize the disinfecting chamber  33 . Again, so as to avoid pressure induced leakage or compromised physical integrity of the apparatus, a plurality of vents  5  and  16  are present to relieve the pressure formed in disinfecting chamber  33 . Among other factors, the shape and size of the primary neutralizing component  25  and its location relative to basket(s)  32  can be designed and controlled in such a way as to generate sufficient heat as well as agitation to optimize the cleaning of the articles for use in basket(s)  32 . 
         [0037]    When the primary neutralizing component  25  is dislodged from its attachment to the stem  18  and the bottom wall  14 , the color indicator band  24  which is hidden until then, becomes exposed. Its exposure thus indicates to the user that the neutralizing reaction has started and the contact lens will soon be ready for use after a specified period, for instance after a few hours, such as 4 to 6 hours, and/or upon confirmation that bubbles are no longer formed by the reaction. 
         [0038]    In one embodiment, the lens basket(s)  32  are oriented with a central bias such that when the cap  11  forms a closure with the container  1 , the percent fill volume to total internal volume is such that the lenses in the baskets stay submerged regardless of the apparatus&#39;s orientation. 
         [0039]    Although limited embodiments of the cleaning/disinfecting assembly and its components have been specifically described and illustrated herein, many modifications and variations will be apparent to those skilled in the art. For example, various types of vents could be used, the attachment of the primary neutralizing component can be mediated by different engagement means such as friction fitted closure, such as a pressure fit closure, or a snap-fit closure, or a pop-off closure or the like; the seal between the cap and the container can be strengthened with the use of gaskets or O-rings or the like. Alternatively, metals other than platinum could be used to coat the support for the neutralizing components, or other hydrogen peroxide neutralization catalysts such as enzymes like catalase could be used, or non-catalytic neutralizers such as pyruvate and the like could also be used. Furthermore, the neutralizing components could be in alternative forms other than supported solids, such as tablet or powder forms. Additionally, although the above describes an improvement where the neutralizer is a supported neutralizer in communication with the chamber containing the item(s) to be disinfected, it should be obvious to one skilled in the art that any reasonable form of the aforementioned neutralizers could be isolated from that chamber and the pressure could be utilized to force open a release mechanism that only subsequent to sufficient pressure and release puts the neutralizer in communication with the chamber containing the item(s) to be disinfected. 
         [0040]    Many alterations and modifications may be made by those having ordinary skill in the art, without departing from the spirit and scope of the invention. Therefore, it must be understood that the illustrated embodiments have been set forth only for the purposes of examples, and that the embodiments should not be taken as limiting the invention as defined by the following claims. The following claims are, therefore, to be read to include not only the combination of elements which are literally set forth, but all equivalent elements for performing substantially the same function in substantially the same way to obtain substantially the same result. The claims are thus to be understood to include those that have been illustrated and described above, those that are conceptually equivalent, and those that incorporate the ideas of the invention.