Abstract:
A medical instrument sterilization system includes a sterilization tray having a bottom wall and an array of ventilation/mounting holes in the bottom wall. The ventilation/mounting holes are arranged evenly spaced at least in part in the bottom wall. Preferably the ventilation/mounting holes comprise a central portion and one or more lobes. In a particularly preferred embodiment, the ventilation/mounting holes comprise a plurality of like cruciform-shaped holes. Completing the invention are one or more rigid brackets having posts arranged to project through the ventilation/mounting holes for anchoring at selected positions on the tray.

Description:
FIELD OF THE INVENTION 
     This invention relates to the field of sterilization of surgical instruments. More particularly, the invention relates to an improved system for securing surgical instruments at fixed positions in sterilization trays. 
     BACKGROUND OF THE INVENTION 
     Surgical instruments are often transported in trays prior to use. The instruments are usually laid out in a certain way in the tray and subjected to sterilization in a steam autoclave or similar sterilization apparatus. In order to maintain separations between the various instruments in the tray, the instruments are supported or retained by brackets, clips, posts or other fixation devices positioned in the tray. Following sterilization, the tray full of instruments is transported to an operating room and placed close to the surgical team whose members withdraw the instruments from the tray as needed for a particular surgical procedure. Many times, the instruments are selectively arranged in the tray so that they can be picked from the tray in the general order that they are needed for the particular procedure. Examples of such trays are found in U.S. Pat. Nos. 4,643,303; 5,424,048 and 5,492,671. 
     As seen from the above patents, the known devices for organizing and fixating medical instruments in a tray include various types of brackets, clips and posts which project up from the bottom of the tray, the instruments being held in place within slots and clip openings and/or between the posts. A plurality of such fixation devices are spaced running parallel or perpendicular to each other in the tray so that they engage and support the opposite sides or ends of various different length instruments. 
     Most prior art fixation devices are able to effectively locate and hold instruments which are more or less straight and regularly shaped. However, they are not particularly suitable for fixating oddly or irregularly shaped instruments such as retractors and other longer instruments that have, e.g. ring handles. This is because there is insufficient flexibility in the placement of the various fixation devices within the tray as to enable the devices to closely engage the instruments while still organizing the instruments in an efficient layout within the tray. This results from the fact that the fixation devices often are plugged into the ventilation holes usually present in the bottom of the tray such that a fixation device only can be placed where there are holes in the bottom of the tray. 
     As the number of such holes is limited by manufacturing cost, required tray bottom strength and the need to prevent the instruments from projecting through the holes, so also are the positions of the various fixation devices. Consequently, either the tray contains too few properly fixated instruments or a larger number of instruments some of which may not be properly fixated. Thus, if the tray is shaken or tilted, instruments may become disengaged from the fixation devices and assume skewed positions in the tray so that they may become damaged and difficult to remove without upsetting other instruments in the tray. In extreme cases, loose instruments may even fall out of the tray and become contaminated. Since a tray may contain a complete set of instruments needed for a particular surgical procedure, this may require that another full tray of sterilized instruments be made available to the surgical team. 
     Another consideration is that the instruments required to perform a specific surgical procedure may vary greatly between hospitals and even surgical teams within specific hospitals. Therefore, it is practically impossible to design a standard tray configuration that will be acceptable for all hospitals and surgical teams. Thus, an optimum instrument fixation arrangement is one which is enormously flexible so that it can be customized to each individual hospital and surgical team, because the numbers and types of instruments being presented in the trays change constantly. 
     In order to overcome the aforesaid problems of the prior art, there is proposed in U.S. Pat. No. 5,827,487 a surgical instrument fixation device for use in a sterilization tray, comprising a rail of optional length and having at least two pegs projecting from the underside of the rail which are sized and spaced apart so as to be able to plug into at least two of the ventilation holes in the bottom wall of the tray. As disclosed in the aforesaid U.S. Pat. No. 5,827,487, the ventilation holes are usually arranged in a rectangular array of columns and rows so that a rail can be positioned at any location within a column or row, i.e. running parallel or perpendicular. Typically, the rails are releasably fixed in position by threaded fasteners driven from the underside of the tray. 
     However, since surgical instruments come in a wide variety of shapes and forms, it is impractical to have a single rail type fixation device for all types of surgical instruments. Thus, the art has developed various systems wherein supports and dividers for the surgical instruments are provided in modular or kit form for selective positioning within the tray, for example, by plugging selected support elements through holes in a portion of the tray and fixing the element in place. The support elements can thus be arranged to match the shape of the surgical instrument to be sterilized. 
     Examples of such products are shown in U.S. Pat. No. 4,135,868 to Sheinholz and U.S. Pat. No. 5,384,103 to Miler. Similar products are commercially available from companies such as Poly-Vac, Incorporated of Manchester, N.H. and other suppliers. Some of these prior devices include integrally molded stubs, for example positioned on the bottom of the flexible inserts, which stubs can be locked into the ventilation holes in the tray as shown, for example, in FIG. 1 of Miller U.S. Pat. No. 5,384,103. They may also comprise separate, rigid holding elements such as shown in FIG. 3 of the above &#39;103 patent where a rigid holder for the support element is fastened by threaded fasteners to the tray or to a shelf carried by the tray. In the &#39;868 patent, the support element for a soft sponge rubber, constituting a hold down pad, is supported by a channel member having outwardly extending buttons which can be forced into ventilation holes in the cover or base of the sterilizing tray. Another prior U.S. patent, U.S. Pat. No. 4,798,292 shows hollow pegs having elongated legs which are used for attachment to a perforated sterilizer tray. 
     While all of the systems described in the prior patents and commercially available products provide a certain amount of flexibility, they do not provide both strong security for the support members and low cost. Nor do they allow for ease of removal of a securely mounted support so that the supports can be differently positioned in the sterilization trays for holding different shapes of surgical instruments to be sterilized. 
     In order to address this latter problem, there is described in U.S. Pat. No. 5,599,512 a commercially available (from Poly Vac, Inc., of Manchester, N.H.) sterilization support element provided with sets of resiliently deformable bayonet type fingers for locking the support elements in position in ventilation holes in bottom wall of a sterilization tray. The support elements are simply and easily removed and repositioned in the tray by means of a simple tool which engages the ends of the bayonet fingers, and pushes them back through the holes. 
     While all of the systems described in the above prior patents, and in commercially available products provide a certain amount of flexibility, they all have disadvantages. They all require tools for assemblying and/or removing the supports or dividers. Also, those prior art systems employing threaded fasteners, locking rings or the like, require extra parts counts. Additionally, since the mounting holes are arranged in parallel rows, standard fixation devices and separators are limited to parallel and/or perpendicular positioning relative to one another. 
     SUMMARY OF THE INVENTION 
     It is thus an objection of the present invention to overcome the aforesaid and other disadvantages of the prior art. 
     More particularly, in accordance with the present invention, a sterilization tray in which the bottom wall of a sterilization tray is populated at least in part with evenly spaced ventilation/mounting holes. Preferably the ventilation/mounting holes comprise a central hole and one or more lobes. In a particularly preferred embodiment, the ventilation/mounting holes comprise a plurality of like cruciform-shaped holes. Completing the invention are one or more brackets having posts arranged to project through the ventilation/mounting holes for anchoring at selected positions on the tray. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Yet other objects and advantages of the present invention will be apparent in the following detailed description of the invention, taken in conjunction with the accompanying drawings wherein like numerals depict like parts, and wherein: 
     FIG. 1 is a top view of a sterilization tray system made in accordance with the present invention; 
     FIGS. 1 a ,  1   b ,  1   c  and  1   d  are enlarged top plan views showing details of mounting/ventilation holes in accordance with the present invention; 
     FIG. 2 is an enlarged perspective view of one form of bracket portion of the present invention; 
     FIG. 3 is an enlarged, perspective view of a mounting post portion of a bracket of the present invention; 
     FIGS. 4,  5  and  6  show alternative embodiments of sterilization trays made in accordance with the present invention; 
     FIG. 7 is a view similar to FIG. 2 showing another embodiment of fastening bracket made in accordance with the present invention; 
     FIG. 8 is an enlarged perspective view of an alternative fastening bracket in accordance with the present invention; 
     FIG. 9 is a view similar to FIG. 8, but taken from the bottom; 
     FIG. 10 is an enlarged view showing details of the post portion of the bracket of FIG. 7; and 
     FIG. 11 is an enlarged view, similar to FIG.  7  and showing another alternative embodiment of fastening bracket in accordance with the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to FIGS. 1-3, the sterilization tray system in accordance with the present invention comprises a rigid, rectangularly shaped tray  20  having a pair of side walls  22 ,  24 , a pair of end walls  26 ,  28 , and a bottom wall  30  defining a generally rectangular interior space. Preferably tray  20  is provided with integral feet  32  so that the tray bottom wall  30  is spaced above the surface upon which it is placed. 
     Formed in the tray bottom wall  30  are a plurality of holes  32 . Holes  32  are evenly spaced from one another by an on center distance D in a plurality of vertical, horizontal and diagonal columns. Holes  32  serve the dual purpose of permitting ingress or egress of steam or other sterilant to circulate through the tray, and also serve for locating instrument brackets or dividers as will be described in detail hereinafter, interiorly of the tray. In a preferred embodiment of the invention, holes  32  are formed in a cruciform shaped pattern having a central portion  34  and four evenly spaced lobes  36  (see FIG. 1 a ). However, the holes  32  may comprise a center portion  34  and three lobes  36  (see FIG. 1 b ), or a central portion  34  and two lobes  36  (FIG. 1 c ). In yet another embodiment of the invention, hole  32  comprises a dumb-bell shaped hole consisting of a large and a small lobe  36   a ,  36   b , respectively. 
     The sterilization tray system in accordance with the present invention also includes one or more support brackets  40  in which are mounted instrument dividers  42 , or instrument damps  44  or the like. Referring in particular to FIGS. 2 and 3, bracket  42  comprises an elongated rail having a T-shaped channel  46  in which a selected divider  42  or instrument clamp  44  is slidably mounted. Each bracket  40 , which may be formed of a rigid plastic or the like, is anchored in selected locations in holes  32  to the bottom wall  30  of the tray by means of posts  48  which extend through stepped holes  50  in brackets  40 , and project from the bottom of the bracket. Each post  48  has a reduced diameter neck or groove  50  and a flange  52  formed at the distal end thereof, and an enlarged head  54  and a knurled body portion  56  for press-fitting into stepped holes  50  in bracket  40 . Reduced diameter neck  50  has a length approximating that of the thickness of tray bottom wall  30 . 
     Posts  48  are spaced apart by a distance equal to twice the distance between holes  32 . Also, flange portions  52  are sized to fit through central portion  34  of holes  32  (shown in dotted lines), but are oversized relative to the node portions  36 . Thus, posts  48  may be loaded into holes or removed from holes  32  by the center portions. However, the brackets  40  may then be locked in place by sliding the brackets with their associated posts into the nodes  36 . 
     A feature and advantage of the present invention is the ability to universally mount dividers and brackets at essentially any location on the tray. Thus, by providing holes  32  evenly spaced across the tray bottom wall, brackets  40  may be mounted at any location running in a horizontal, vertical or diagonal direction. Moreover, no special tools are needed for mounting and unmounting the brackets, it being a simple matter to locate the brackets in the desired holes, and then slide the brackets from central locations in the holes into a corresponding node position whereupon the pins and associated brackets will become friction held in position on the tray. 
     Referring to FIGS. 4 and 5, in a preferred embodiment of the invention, brackets  40  comprise short stub brackets each having a pair of posts  48  extending therethrough. Of course, the brackets can be made longer, and have three or more spaced posts. However, an advantage of the present invention is that it permits the sterilization tray system to be manufactured, packaged and used as a kit of parts. Thus, a plurality of brackets  40  may be packaged together with a variety of dividers or slotted instrument clamps, etc., which may be made of, for example, silicone rubber. Silicone rubber is relatively easily cut. Thus, the user could purchase elongated strips or rolls of silicone rubber strips, cut them to desired length, and thus customize a tray in the field. 
     FIGS. 6-11 illustrate alternative forms of posts, brackets, dividers, and instrument supports in accordance with the present invention. Referring in particular to FIGS. 7-10, the instrument dividers/supports comprise generally L-shaped members  60  formed of silicone rubber or the like, and comprising a upright wall  62  in which may be provided one or more slots  64  for accommodating a surgical instrument (not shown) and a short base wall  66 . Wall  66  is sandwiched between locking brackets  68 , as will be described in detail hereinafter and the tray bottom wall  30 , by means of posts  70  which extend through holes (not seen) in walls  66  and walls  32  in the tray bottom wall  30 . Referring in particular to FIGS. 8,  9  and  10 , post  70  which include an enlarged head  72  are mounted in holes  74  formed in bracket  68  and are friction held in place therein by knarled section  74 . Each post also includes a reduced diameter neck  76  adjacent its distal end, inbound of a flared section  78 . As before, posts  70  preferably are spaced apart a distance equal to twice the spacing D. 
     Referring in particular to FIGS. 8 and 9, in a preferred embodiment of the invention bracket  64  includes a locking post  82  which is carried on a resiliently deformable arm  84 . Locking post  82  normally extends below the lower surface  86  of bracket  68 , and is located between posts  70 , offset from the midpoint therebetween by a distance “Y” which equals the distance between hole central portions  34  and nodes  36 . Thus, when brackets  68  are loaded in holes  32 , and slid into a node position, locking post  82  snaps down locking the bracket in position. However, it is a simple matter to remove bracket  68  by pressing post  82  upwards, and then sliding the bracket back to central position. 
     Various changes may be made in the invention without departing from the spirit and scope thereof. For example, as shown in FIG. 11, the instrument support may comprise a generally U-shaped member having a solid divider wall  90  and a slotted wall  92 . Yet other changes may be made without departing from the spirit and scope of the invention.