Abstract:
A surgical system and cassette, the cassette having a series of identifying tabs that are variably opaque to translucent. By varying the opaqueness of the tabs, the surgical system can readily identify the type of cassette being used.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    This invention relates generally to the field of surgical cassettes and more particularly to an identification system for surgical cassettes.  
           [0002]    The use of cassettes with surgical instruments to help manage irrigation and aspiration flows into and out of a surgical site are well-known. See, for example, U.S. Pat. Nos. 4,493,695, 4,627,833 (Cook), 4,395,258 (Wang, et al.), 4,713,051 (Steppe, et al.), 4,798,850 (DeMeo, et al.), 4,758,238, 4,790,816 (Sundblom, et al.), 5,267,956, 5,364,342 (Beuchat), 6,036,458 (Cole, et al.) and 6,059,544 (Jung, et al.), the entire contents of which being incorporated herein by reference.  
           [0003]    The fluidic performance of the surgical instrument is substantially affected by the fluidic performance of the cassette. As a result, current surgical instrumentation and cassettes are designed to work as an integral system, with the fluidic performance of the cassette designed to optimize the fluidic performance of the entire surgical system. Recent advances made in surgical instrumentation now allow the surgeon to manually or automatically control the operating parameters of the surgical instrumentation to a very fine degree. Specialized cassettes have been developed to allow the surgeon to capitalize on the advance control afforded my modern surgical instrumentation. The operating parameters of the surgical instrumentation, however, must be adjusted depending upon the cassette being used. One system, disclosed in U.S. Pat. No. 6,059,544 (Jung, et al.), has a cassette with a series of frangible tabs that can be used to allow the instrument to recognize the type of cassette being used. While such a system works very well, and has been commercially successful, an alternative method for identifying the cassette that is somewhat easier and less expensive to manufacture is desirable.  
           [0004]    Accordingly, a need exists for a cassette identification system that does not require the use of frangible tabs.  
         SUMMARY OF THE INVENTION  
         [0005]    The present invention improves upon the prior art by providing a surgical system and cassette, the cassette having a series of identifying tabs that are variably opaque to translucent. By varying the opaqueness of the tabs, the surgical system can readily identify the type of cassette being used.  
           [0006]    Accordingly, one objective of the present invention is to provide a surgical cassette that can be readily identified by the surgical instrument in which the cassette is used.  
           [0007]    Another objective of the present invention is to provide a surgical cassette having a series of tabs that are rendered variable opaque in a selected pattern.  
           [0008]    These and other advantages and objectives of the present invention will become apparent from the detailed description and claims that follow. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0009]    [0009]FIG. 1 is a schematic illustration of the system of the present invention.  
         [0010]    [0010]FIG. 2 is a perspective view of a cassette suitable for use with the present invention.  
         [0011]    [0011]FIG. 3 is a perspective view of a surgical console that may be used with the system of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0012]    As best seen in FIG. 1, control system  10  of the present invention generally include input current control circuit  12  and output current measurement circuit  14 , both of which being connected to microcontroller  16 . Input current control circuit  12  controls the input current to light emitting diodes (LEDs)  18  and output current measurement circuit  14  measures the output current from photodetectors  20 . Input current control circuit  12 , output current measurement circuit  14  and microcontroller  16  may be any suitable hardware and/or software system, such systems being well-known in the art. The operation of LEDs  18  and photodetectors  20  being more fully explained in U.S. Pat. No. 6,059,544 (Jung, et al.). System  10  may be included as part of the mechanical and electrical systems in any suitable surgical console, such as the console illustrated in FIG. 3.  
         [0013]    As best seen in FIG. 2, cassette  22  that may be used with system  10  of the present invention generally contains a plurality of tabs  24  projecting from housing  23 . Tabs  24  may be generally of the shape described in U.S. Pat. No. 6,059,544 (Jung, et al.) and may be of variable opaqueness, from completely opaque to partially translucent to relatively clear. The opaqueness of tabs  24  may be used by system  10  in the manner described below. By varying the transmissibility of light through tabs  24 , the number of possible distinct cassettes  22  may be increased without increasing the number of tabs  24 .  
         [0014]    In use, system  20  is calibrated by adjusting the output of LEDs  18 , through input current control circuit  12 , until a set output level in photodetectors  20  is achieved, as measured by output current measurement circuit  14 . Upon insertion of cassette  22  into cassette receiving portion  110  of console  100 , tabs  24  at least partially block the transmission of light from LEDs  18  to photodetectors  20 , as shown in FIG. 1, and subsequently decrease the output of photodetectors  20 . This drop in output from photodetectors  20  is sensed by output current measurement circuit  14 , which relays this drop in output to microcontroller  16 . Microcontroller  16  reads this decrease in the output of photodetectors  20  as an indication that cassette  22  is present in cassette receiving portion  110  of console  100 . Microcontroller  16  may then instruct input current control circuit  12  to increase the output of LEDs  18  to the maximum level. Output current measurement circuit  14  then measures the output of photodetectors  20  with LEDs  18  at this maximum output level, and the output of photodetectors  20  is indirectly proportional to the opaqueness of tabs  24 . In other words, the amount of light from LEDs  18  reaching photodetectors  20 , and thus the output of photodetectors  20 , will decrease proportionately with an increase in opaqueness of tabs  24 . In this manner, the relative opaqueness of tabs  24  can be measured based on the variable amount of light reaching photodetectors  20  from LEDs  18 . By varying the opaqueness of tabs  24  on cassette  24 , the type of cassette  22  can be determined based on the opaqueness of tabs  24  and the pattern of variably opaque tabs  24  on cassette  22 . For purposes of the present invention, each LED  18  is paired with a corresponding photodetector  20 , and system  10  is arranged so that individual tabs  24  correspond to a LED/photodetector pair in a manner similar to that disclosed in U.S. Pat. No. 6,059,544 (Jung, et al.).  
         [0015]    This description is given for purposes of illustration and explanation. It will be apparent to those skilled in the relevant art that changes and modifications may be made to the invention described above without departing from its scope or spirit.