Abstract:
A retainer assembly for retaining a medical device in a container having a perforated wall includes a retainer with a rigid support portion having at least one leg and a flexible, resilient instrument holding portion intimately bonded to the support portion so that the retainer is devoid of cracks and crevices between said portions. Each leg has a free end and an axial passage extending into the leg from that end so that the retainer may be positioned on the container wall with each opening in register with a perforation therein. A fastener extends into the passage of each leg and the underlying perforation from below the wall to anchor each leg to the wall under pressure thereby providing a seal between each leg and the wall. Various retainer embodiments and a method for making same are also disclosed.

Description:
This application is a divisional of co-pending application Ser. No. 11/299,505, filed Dec. 12, 2005. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates to a retainer assembly for retaining medical instruments. It relates especially to a retainer assembly capable of holding medical instruments at fixed positions in a tray or other container while maintaining sterile conditions within the container. 
     There exists in the prior art various retainers and accessories for fixing the positions of articles of one kind or another. These include hooks, pegs, clips, brackets, etc. Such retainers may be used in a wide variety of applications. For example, they are commonly used in the medical field to fix the positions of various surgical instruments, devices and prostheses while those articles are being transported, sterilized and processed in one way or another. Accordingly, we will describe the invention in that context. It should be understood, however, that the present invention has application in other fields is besides the medical field. 
     Medical instruments are often transported in trays. Prior to use, such instruments are placed in the tray and subjected to sterilization. To improve the circulation of steam throughout the tray, the tray bottom wall and perhaps also the side wall are usually perforated. In order to maintain a separation between the various instruments in the tray, the instruments are supported or retained by posts, brackets or other retainers anchored to the tray. Following sterilization, the tray full of instruments may be transported to an operating room and placed close to a surgical team whose members may withdraw the instruments from the tray as needed for the particular surgical procedure being performed. Usually, the instruments are selectively arranged or organized in the tray so that they can be picked from the tray in the order in which they are needed for the particular procedure. Examples of such trays are disclosed in my patents U.S. Pat. Nos. 5,424,048 and 5,681,539. 
       FIG. 1  depicts a typical medical tray shown generally at  10 . The tray has a bottom wall  10   a  and side walls  10   b  extending up from the bottom wall to define a generally rectangular interior space  12 . The tray is usually made of a material able to withstand sterilization, e.g. polyphenylsulphone or a non-corroding metal such as aluminum, stainless steel or titanium. The bottom wall  10   a  of tray  10  is usually formed with a multiplicity of vent holes  16  arranged in columns and rows to allow for circulation of steam or other sterilizing fluid throughout the interior space  12 . As will be described in more to detail presently, these holes may also function as anchoring points for the retainers and accessories used to locate various medical instruments within tray  10 . 
     Tray  10  is adapted to contain a plurality of variously shaped medical instruments I. In order to retain these instruments in the tray, assorted retainers or accessories may be employed. These may include known solitary post assemblies  18  as well as conventional elongated retainer assemblies  20  and  20 ′ having notches or slots for receiving instruments I as shown. 
     As depicted in  FIGS. 1 and 2A , the retainer assembly  20  comprises a unitary retainer  22  molded of a rigid plastic material able to withstand sterilization. The retainer is in the form of an upstanding blade containing notches or slots  22   a  and having a bottom flange  24  so that the retainer has the general shape of an inverted letter T. Threaded holes  26  extend up from the bottom of retainer  22 . These holes are spaced apart along the retainer a distance that is an integral multiple of the spacing between the holes  16  in a given row of holes in tray bottom wall  10   a . Thus, retainer  22  may be positioned on the tray wall  10   a  with its holes  26  in alignment with the vent holes  16  in the tray so that the other components of the assembly  20 , namely threaded fasteners  28 , may be inserted through the vent holes and turned down into the registering holes  26  in retainer  22  as shown in  FIG. 2A . 
     Instead of being a unitary part as depicted in  FIG. 2A , some conventional retainers are composed of two separate pieces which are keyed together. A retainer such as this is shown generally at  22 ′ in  FIGS. 1 and 2B . That retainer comprises a rigid rail  32  molded of a suitable hard plastic material able to withstand sterilization. Spaced-apart threaded holes  34  extend up from the bottom of rail  32  for receiving threaded fasteners  28  to secure the rail to the tray bottom wall  10   a  in the same manner as retainer  22  described above. 
     Rail  32  is adapted to receive and support a blade-like instrument holder  38  made of a flexible, resilient, sterilizable material such as silicone. The holder  38  may be formed with slits or cut-outs  38   a  for holding medical instruments I. In order to mechanically secure the holder  38  to rail  32 , the bottom of the holder is flanged to form a key  40  which is shaped and sized to slidably engage in a keyway  42  formed in the upper portion of rail  32 . 
     The posts of assemblies  18  depicted in  FIG. 1  may be anchored in a similar fashion to the tray bottom wall  10   a  using threaded fasteners  28 . 
     Although these prior retainer assemblies perform their instrument retaining function satisfactorily, they may not pass new safety requirements being proposed by the FDA to ensure that medical trays and their contents are free from contamination. That is, more emphasis is being placed on being able to demonstrate the ability to thoroughly clean and sterilize such products. The FDA is particularly concerned with cleaning and sterilization at mating surfaces such as the undersurfaces of the retainer  22  and rail  32  where they meet the tray wall  10   a , as well as the opposing surfaces at the boundary between the silicone holder  38  and the rail  32  of the retainer assembly  20 ′ shown in  FIG. 2B . If that holder  38  is flexed laterally, an appreciable may open between the holder and the rail. All of these locations have the possibility of trapping bacterial contamination and protecting same during the sterilization process. In fact, the only way to ensure a proper cleaning of these surfaces is to dissemble all of the retainer assemblies and remove them from the tray  10  so that all of the parts can be sterilized separately. Of course, all of the retainer parts must then be reassembled in the tray for the next operation. Needless to say, this is a tedious task and is not desirable from the standpoint of efficiency. Also, in their disassembled state, the various small parts may be misplaced or lost while being processed. 
     SUMMARY OF THE INVENTION 
     Accordingly the present invention aims to provide a retainer assembly for use in a medical tray or other container which minimizes the potential for bacterial contamination within the tray. 
     Another object of the invention is to provide a retainer assembly such as this which does not have to be separated from the tray in order to thoroughly clean and sterilize the tray and assembly components. 
     Yet another object of the invention is to provide a retainer assembly whose construction minimizes the likelihood of bacterial contamination in and around the assembly. 
     A further object is to provide a retainer consisting of a unitary part which may be rigidly anchored to a container wall while resiliently retaining various medical instruments placed in the container. 
     Still another object of the invention is to provide such a retainer which can be made in quantity relatively inexpensively using conventional molding or machining techniques. 
     Another object of the invention is to provide a method of making such a retainer having one or more of the above advantages. 
     Other objects of the invention will, in part, be obvious and will, in part, appear hereinafter. 
     The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others, and the article possessing the features, properties and the relation of elements, all as exemplified in the following detailed description, and the scope of the invention will be indicated in the claims. 
     In general, the present retainer assembly comprises an instrument retainer for placement in a container such as a medical tray, and fastening means for anchoring the retainer to a wall of that container at one or more anchoring points. 
     The retainer has at least one rigid exposed support portion each having at least one anchoring point for receiving a fastener and a flexible, resilient instrument holding portion bonded to each support portion so that the retainer is essentially a unitary part completely devoid of cracks and joints in which bacteria could develop and multiply. Thus, the retainer assembly provides both a secure mechanical attachment to the container and a holding portion which may be configured to resiliently engage and fix within the container a variety of differently shaped and sized medical instruments and devices. 
     As we shall see, when forming the retainer an intimate bond is obtained between the resilient holding portion and the rigid support portion of the retainer by positioning an already formed support portion in a mold and injection molding a holding portion directly onto and around the support portion so that the two portions become as one. After the molding process, the holding portion may be cleaned and profiled to support various medical instruments and devices. 
     As will be described in more detail later, the holding portion of the retainer may be in the form of an elongated slotted blade designed to engage around or receive the medical instruments or it may be in the form of a fence or post positioned to corral instruments placed in the container. In each case, the holding and support portions of the retainer are intimately bonded together to minimize any possibility of bacterial in-growth thereon. 
     In a preferred embodiment of the invention, the retainer has an integral seal at each anchoring point thereof which, when the retainer is anchored to the container wall, surrounds the fastener at the corresponding anchoring point thus preventing in-growth of bacteria between the retainer and the container wall at that anchoring point. If a particular retainer has more than one anchoring point, the retainer is preferably shaped so that its anchoring points extend below the remainder of the retainer so that when the retainer is anchored to the container wall by the fasteners, each seal seats against the container wall. In one preferred embodiment of the invention, the seal is a knife edge depending from the support portion and encircling the fastener to provide a high pressure line contact between the support portion of the retainer and the container wall. In a second preferred embodiment of the invention, the seal is an extension of the holder portion of the retainer which extension forms a flexible resilient line contact seal around the fastener. Both seals prevent the infiltration of bacteria at the interface between the retainer and the container wall. 
     It is a further feature of the invention that the present retainers can be made relatively inexpensively in quantity using standard molding or machining techniques. Therefore they should be comparable in cost to conventional retaining devices which do not have the same advantages in terms of ease of use and freedom from bacterial build up. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description taken in connection with the accompanying drawings, in which: 
         FIG. 1 , already described, is a perspective view with parts broken away showing conventional retainer assemblies installed in a medical tray; 
         FIGS. 2A and 2B  are elevational views of the known retainer assemblies shown in  FIG. 1 ; 
         FIG. 3  is a schematic diagram showing the steps for making the retainer component of a retainer according to the present invention; 
         FIG. 4A  is a fragmentary elevational view on a larger scale and with parts in section showing a retainer made in accordance with  FIG. 3  and assembled to a container; 
         FIG. 4B  is a fragmentary perspective view of the retainer in the  FIG. 4A  assembly; 
         FIG. 5  is a similar view showing another retainer embodiment; 
         FIG. 6  is a perspective view illustrating still another retainer embodiment, and 
         FIG. 7  is a perspective view on a smaller scale illustrating yet another embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring to  FIGS. 4A and 4B  and the right hand side of  FIG. 3 , my improved retainer shown generally at  48  comprises a rigid support portion  50  in the form of an elongated beam and an upstanding flexible resilient blade-like instrument holding portion indicated at  52  which is intimately bonded to support portion  50 . The support portion includes one or more legs  50   a  each of which extends below portion  50  per se to provide an anchoring point. As best seen in  FIGS. 4A and 4B , each leg  50   a  is formed with a threaded passage  54  which extends in from the lower end of the leg for anchoring the retainer to the wall of a container such as the bottom wall  10   a  of the medical tray illustrated in  FIG. 1 . For this, each leg  50   a  is located on base portion  50  so that it can be placed in register with a hole  16  in tray wall  10   a . This enables a fastener  28  to be inserted from below the tray through that registering hole and screwed into the passage  54  in the corresponding leg  50   a . Of course, if the retainer legs  50   a  do not line up with the holes  16  in the tray wall, additional such holes may be drilled through that wall at the appropriate places to accommodate the retainer. In any event, when the retainer is anchored to the tray wall  10   a  by fasteners  28 , the retainer assembly is complete. 
     Although superficially the present retainer  48  appears similar to some prior instrument retaining brackets of this general type such as the one depicted in  FIG. 2B , it differs in several important respects. More particularly, the support portion  50  of the present retainer  48  is actually used to help form the holding portion  52  thereof. 
     More particularly, as shown in  FIG. 3 , in a first step, the rigid support portion  50  is formed of a suitable sterilizable plastic or metal using a conventional molding or machining process. It is made not only with one or more legs  50   a , but also with an integral upstanding rail  50   b  with which the holding portion  52  will interfit. Since the illustrated support portion  50  is in the form of an elongated beam, the rail in crosssection resembles the letter T. Of course, the rail  50   b  may be otherwise shaped to interfit with holding portion  52  as will be described. For example, portion  52  may comprise a column of spaced-apart upstanding posts or barbs. 
     In any event, after the support portion  50  is formed, in a second step, that portion is placed in a mold  60  having a cavity  60   a  shaped to accommodate support portion  50  so that that portion constitutes one wall of the cavity and so that the rail  50   b  of portion  50  projects into the cavity. The mold  60  may be of any standard design having an injection port  60   b  for injecting a plastic material P into cavity  60   a  that cavity being shaped to form the instrument holding portion  52  of the retainer. Preferably, the mold includes a vent passage  60   c  to vent air from cavity  60   a  as the cavity is being filled with plastic material. 
     The plastic material P may be any material conventionally used to resiliently hold medical instruments and devices, the preferred material being silicone. 
     During the injection molding process, the plastic material P is deposited to directly onto and around the bonding surfaces of the support portion  50  exposed in mold cavity  60   a . Thus an intimate bond is formed between the plastic P and those surfaces. Resultantly, when the molding process is completed and the support portion is removed from mold  60 , the plastic material P that has formed the holding portion  52  of the retainer is not only mechanically anchored to the rail  50   b  of support portion  50 , but also it is intimately bonded to the bonding surfaces of that portion so that the retainer is completely devoid of any gaps, cracks or crevices that could provide refuge for bacteria and other contaminants. 
     After the injection molding step has been completed, the molded product may be cleaned and its holding portion  52  profiled, in a third step, to form the desired instrument retaining slots and notches  56  using a conventional water jet or die-cutting process. 
     The present retainer differs from others also in that its leg(s)  50   a  extend well below support portion  50  and holding portion  52 . Also, the leg(s) in crosssection are larger than the holes  16  in tray wall  10   a . Resultantly, when the retainer is anchored to the tray wall  10   a  as shown in  FIG. 4A , the leg(s) act as spacers so that a relatively large gap G exists between the retainer per se and the tray wall. In other words, the retainer only contacts the tray wall directly underneath the leg(s)  50   a  so that when the tray and its contents are being sterilized, the sterilizing fluid can circulate underneath the retainer per se so that there can be no bacterial build up there. 
     As for the small areas underneath the retainer legs  50   a , it has been found that these areas do not tend to trap contamination because each leg  50   a  is held against the tray wall  10   a  under relatively high contact pressure due to the associated fastener  28 . However, in a preferred embodiment of the invention, an especially high contact pressure engagement of each leg  50   a  with the tray wall  10   a  is assured by forming each leg end with a depending circular knife edge  50   b  at the perimeter of leg  50   a  and which surrounds the fastener hole  54  as shown in  FIGS. 4A and 4B . Thus when the associated fastener  28  is turned down into hole  54 , the knife edge  50   b  is urged against the tray wall  10   a  under very high pressure due to its small contact area so that there is no possibility of biological contaminants passing between the leg and the container wall. 
     Refer now to  FIG. 5  which shows another retainer embodiment indicated at  70  in which a support portion  72  of the retainer is fully encapsulated within a holding portion  74  except for the undersurface of each leg  72   a  of the support portion. In other words, the holding portion  74  is injection molded around support portion  72  so that a wall  74   a  of the holding portion extends under the support portion and around the side of each leg  72   a . Preferably also, that wall extends beyond the end of each leg to form a flexible resilient lip or flange  74   b  as shown in  FIG. 5 . Thus, when the retainer is positioned in the tray  10  and anchored to the tray wall  10   a  by fasteners  28  as in  FIG. 1 , each flexible resilient lip  74   b  is drawn against the tray wall forming a resilient knife edge seal around the associated fastener which prevents the introduction of contaminants at each anchoring point of the retainer to the tray wall. 
       FIG. 6  illustrates yet another retainer embodiment shown generally at  80 . In this case, the flexible, resilient instrument holding portion  82  comprises a pair of sleeves  82   a  injection molded around a pair of spaced-apart rigid posts  84  with a web  82   b  extending between the two sleeves. The posts  84  comprise the holding portion of this retainer. Preferably, the posts have ends  84   a  which extend beyond or below the lower ends of sleeves  82   a  and threaded fastener holes  86  extend in from those post ends. Thus, when retainer  80  is secured to tray wall  10   a  by fasteners  28  in the manner of retainer  48  described above, the holding portion  82  thereof is spaced above the tray wall. Also of course, the projecting ends  84   a  of posts  84  may be formed with a sealing flange similar to flange  50   b  on retainer  48  described above and shown in  FIGS. 4A and 4B . Alternatively, the sleeves  82   a  may extend down around the post ends  84   a  to form a resilient seal similar to seal  74   b  described above in connection with retainer  70  in  FIG. 5 . In any event, when retainer  80  is secured to the tray wall  10   a , it constitutes a fence or barrier which may be used to restrain or corral a medical instrument or device within the tray  10 . 
     Of course, other fasteners may be used in my retainer assembly to anchor the various retainer embodiments to the container wall. For example, the retainers may be permanently anchored to the tray by rivets. Also, to accommodate trays having different wall thicknesses, the assembly may include the fastening means of the type disclosed to in my application Ser. No. 11/177,541, filed Jul. 8, 2005, the contents of which are hereby incorporated by reference herein. 
       FIG. 7  shows generally at  90  another retainer embodiment having a rigid support portion  92  onto which is injection molded a flexible resilient instrument holding portion  94 . Support portion  92  may be a stamped metal part formed with one or more legs  92   a  which extend from an edge of holding portion  94 . These legs may be used to anchor the retainer to container wall  10   a  by inserting fasteners  96  e.g. screws, rivets or friction pins, through the legs and the wall. As with the other retainer embodiments, the holding portion  94  forms an intimate bond with the support portion  92  so that the retainer is devoid of potential contamination sites. 
     Thus the present retainer assemblies provide a rigid connection to the container wall and a resilient engagement with the medical instruments which they retain. Yet they are devoid of joints and interfaces which could be sites for bacterial infestation. Retainer assemblies made in accordance with this invention can remain in place in a medical tray or other container during sterilization with assurance that after the sterilization process is completed, the tray and its contents will be clean and free of bacterial contamination and will conform to any standards imposed by FDA. This ability to leave the retainer(s) in the tray will make the sterilization process much more efficient and will free up medical personnel to do other important tasks. 
     It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efficiently attained. Also, certain changes may be made in carrying out the above method and in the constructions set forth without departing from the scope of the invention. For example, retainers in the form of silicone sheathed posts similar to posts  18  in  FIG. 1  may be made according to this invention simply eliminating the web  82   b  when molding the sleeves  82   a  of the  FIG. 6  retainer. Therefore, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 
     It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention described herein.