Abstract:
The present invention relates to the field of medical devices, and more specifically to a radiolucent surgical handle system which utilizes properties of silicone and channel geometry to create a more responsive and stable medical instrument. Channel geometry is utilized to stabilize the outer silicone gripping layer, thus preventing axial, planar, lateral or angular movement of the silicone gripping layer under conditions of torque force during a surgical operation.

Description:
FIELD OF INVENTION 
       [0001]    The present invention relates to the field of medical devices, and more specifically to a surgical instrument handle which is radiolucent, highly stable and responsive under torque force due to the utilization of novel channel geometry to stabilize the outer silicone gripping layer. 
       TERMS OF ART 
       [0002]    As used herein, the term “dovetailed tab” means a protruding structure integrally formed from silicone which is t-shaped or y-shaped. 
         [0003]    As used herein, the term “dovetailed channel” means a channel having adjacent recesses which are adapted to form t-shaped or y-shaped silicone structures. 
       BACKGROUND 
       [0004]    X-ray imaging is used during orthopedic surgery and other medical procedures to guide surgeons in real time, and also to verify completed procedures while the patient is still on the operating table. Surgeons use specialized medical tools to complete their work, and at times these tools cannot be removed from the field of x-rays. Typical tools have stainless steel or other metal in the handles that can block x-rays and thus affect surgical outcomes. It is desirable to have tools with handles that are radiolucent so they do not block x-rays. 
         [0005]    Radiolucent materials are known in the art. Silicone is a highly effective material for surgical handles because it is lightweight and provides a sure grip, and it is also radiolucent. However, silicone must be supported by a strong inner frame structure, usually comprised of a material that is not radiolucent such as stainless steel. 
         [0006]    Attempts have been made to design inner skeletal frame structures for surgical tool handles using radiolucent materials. For example, U.S. Patent Application No. 2007/0290399 A1 (Easter) discloses a surgical tool handle with an outer silicone gripping layer and a radiolucent inner skeletal support structure which directs the flow of silicone though channels in the frame to form spines with overlapping edges that serve as interlocking components. 
         [0007]    It is known in the art that surgical tools must be stable and must avoid the problem of lateral movement of the silicone over the inner skeletal frame. Attempts in the art to manufacture radiolucent tool handles have focused on design of inner skeletal frames. 
         [0008]    It is desirable have a design which maximizes the stability of a torque resistant radiolucent handle which optimizes and varies the geometry of the inner skeletal frame of the tool to prevent the composite layers from slipping against each other and achieves the strength of metal tools. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention is a torque-resistant radiolucent handle surgical tool with optimized radiating silicone flow channels that utilize novel geometric features to prevent axial, planar, lateral or angular movement of the silicone gripping layer under conditions of torque force during a surgical operation. 
         [0010]    The outer silicone gripping layer is bound to the inner skeletal frame by a plurality of angled silicone tabs, rather than spines known in the art. The channel geometry utilizes novel segmented or spiral configurations with unique structural features, including t-shaped and y-shaped dove tail structures which provide increased stability over edged spines. The degree of the outer channel retaining angles may be varied to optimize resistance to torque force without disrupting the flow of silicone. The ratio of channel depth to channel floor, the space between channels and the depth of the dovetail are improved geometric structures which improve the stability of the tool. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is an exploded view of an exemplary embodiment of a radiolucent handle system illustrating an inner skeletal frame and outer silicone gripping layer in use with a surgical tool. 
           [0012]      FIGS. 2   a  and  2   b  are cross-sectional views which illustrates the contours the inner surface of an outer silicone gripping layer with integrated angled dovetailed silicone tabs. 
           [0013]      FIG. 3   a  illustrates an exemplary embodiment of an inner skeletal frame for a radiolucent handle system. 
           [0014]      FIG. 3   b  illustrates a sectional view of an exemplary embodiment of an inner skeletal frame for a radiolucent handle system illustrating a configuration of radiating silicone flow channels. 
       
    
    
     DETAILED DESCRIPTION OF INVENTION 
       [0015]    For the purpose of promoting an understanding of the present invention, references are made in the text to exemplary embodiments of a geometrically coalesced instrument handle, only some of which are described herein. It should be understood that no limitations on the scope of the invention are intended by describing these exemplary embodiments. One of ordinary skill in the art will readily appreciate that alternate but functionally equivalent structures and materials may be used. The inclusion of additional elements may be deemed readily apparent and obvious to one of ordinary skill in the art. Specific elements disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one of ordinary skill in the art to employ the present invention. 
         [0016]    It should be understood that the drawings are not necessarily to scale; instead, emphasis has been placed upon illustrating the principles of the invention. In addition, in the embodiments depicted herein, like reference numerals in the various drawings refer to identical or near identical structural elements. 
         [0017]      FIG. 1  is an exploded view of an exemplary embodiment of a radiolucent handle apparatus  100  for use as a surgical tool, which includes an outer silicone gripping layer  31  and an inner skeletal frame  10  that acts as an inner stabilizing component. 
         [0018]      FIG. 1  illustrates an asymmetrical inner skeletal frame  10  with a flattened angular end  10   a,  a continuous cylindrical center portion  10   b,  and a curved flattened end  10   c.  The exemplary embodiment of an outer silicone gripping layer  31  shown in  FIG. 1  has an inner surface  32  and an outer surface  34 . 
         [0019]    Also illustrated in  FIG. 1  are radiating silicone flow channels  20   a  and  20   b.  In the exemplary embodiment shown in  FIG. 1  each radiating silicone flow channel has an open channel end  22  and a terminating channel end  23 .  FIG. 1  also depicts an inner channel floor  26 . 
         [0020]    In the embodiment shown in  FIG. 1 , radiating silicone flow channels  20   a  and  20   b  are alternately placed so that each of the radiating silicone flow channels  20   a  and  20   b  has a terminating channel end  23  and an open channel end  22  placed opposite of the terminating channel ends  23  and the open channel ends  22  of the radiating silicone flow channels  20   a  and  20   b  adjacent to it. 
         [0021]      FIGS. 2   a  and  2   b  illustrate cross-sectional views of two exemplary embodiments of a radiolucent handle apparatus  100 . 
         [0022]      FIG. 2   a  illustrates the contours of the inner surface of a silicone layer with integrally formed angled dovetailed silicone tabs  33   a - 33   c  protruding above the inner surface  32  of the outer silicone gripping layer  31 . Angled dovetailed silicone tabs  33   a - 33   c  are disposed of outer channel retaining angles  40   a,    40   b  of 90 to 150 degrees. 
         [0023]    In various embodiments of the apparatus, inner surface  32  may have more or fewer angled dovetailed silicone tabs  33   a - 33   c  to withstand torque force and to be adapted to the contours and dimensions of a particular surgical tool. Outer channel retaining angles  40   a,    40   b  may be varied to accommodate torque force characteristics. Additionally, the length and width dimensions of inner channel floor  26  may be varied proportionally to accommodate the torque force, dimensions and mechanical characteristics of a specific surgical tool to which the radiolucent handle apparatus  100  may be attached. 
         [0024]    The shape of the angled dovetailed silicone tabs  33   a - 33   c  is critical to stabilizing the outer silicone gripping layer  31  and securing it to inner skeletal frame  10  so that there is no axial, planar, lateral or angular movement of the silicone gripping layer under conditions of torque force during a surgical operation. 
         [0025]      FIG. 2   b  illustrates an outer silicone gripping layer  31  comprised of an asymmetrical tubular body having an inner surface  32  and an outer surface  34 . Outer silicone gripping layer  31  includes a flattened angular end having a first inner diameter D 1 , a continuous cylindrical center having a second inner diameter D 2 , and a curved flattened end having a third inner diameter D 3 . In the embodiment shown, D 1  is greater than D 3 . 
         [0026]      FIG. 2   b  illustrates an embodiment in which radiating silicone flow channels  20   a - 20   c  are contiguously arranged in a continuous spiral configuration. 
         [0027]      FIG. 3   a  illustrates an exemplary embodiment of an inner skeletal frame  10  for a radiolucent handle system  100  illustrating a configuration of radiating silicone flow channels  20   a - 20   c.  The inner skeletal frame  10  is a primary stabilizing component that has a flattened angular end  10   a,  a continuous cylindrical center portion  10   b,  and a curved flattened end  10   c.    
         [0028]    In the embodiment shown in  FIG. 3   a , the radiating silicone flow channels  20   a - 20   c  are alternately placed so that each radiating silicone flow channel  20   a  and  20   b  has a terminating channel end  23  and an open channel end  22  placed opposite of the terminating channel ends  23  and open channel ends of the radiating silicone flow channels  20   a  and  20   b  adjacent to it. 
         [0029]    In the embodiment shown in  FIG. 3   a , the width of each of the terminating ends  23   a - 23   c  is greater than the width of the channel opening  22   a - 22   c.  Each terminating end is bounded by an angled opposing dovetailed channel side  24   c  and  24   d  (not shown). Each of the opposing sides create a force to oppose movement of the angled dovetailed silicone tabs  33   a  and  33   b  (not shown). 
         [0030]    As shown  FIG. 3   a , each radiating silicone flow channel further includes elongated inner channel floor  26 , two dovetailed angled side surfaces  28   a,    28   b,  and illustrates two outer channel retaining portions  42   a,    42   b.  Each dovetailed angled surface and outer channel retaining portion encloses a dovetailed recess that receives a corresponding angled dovetailed silicone tab  33   a,    33   b  (not shown). 
         [0031]      FIG. 3   b  illustrates a sectional view of a radiolucent handle system  100  with inner stabilizing geometric components, including inner skeletal frame  10  and outer silicone gripping layer  31 , which utilize principles of highly stabilizing channel geometry. 
         [0032]    In the embodiment shown in  FIG. 3   b , outer channel retaining angles  40   a,    40   b  are angled, perpendicular or substantially perpendicular to inner channel floor  26  and partially enclose said channel and provide a silicone retention barrier. 
         [0033]    In the the exemplary embodiments shown, the ratio of non-channel surface area to channel space is less than 30 percent. 
         [0034]    In these exemplary embodiments, the ratio of the height of angled dovetailed silicone tab  33  to the inner channel floor  26  to the width of the elongated portion of the tab is 40 to 50 percent.