Abstract:
A medical instrument includes a handpiece having irrigation and aspiration channels, a connector coupled to the handpiece by a sliding friction fit and having channels forming continuations of the irrigation and aspiration channels, and a removable tip threadedly coupled to the connector.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims the benefit of U.S. Provisional Application No. 60/341,975, filed on Dec. 18, 2001. 

   FIELD OF THE INVENTION 
   The present invention relates to medical devices, but in particular to irrigation-aspiration (I/A) devices such as those used during cataract surgery. 
   BACKGROUND OF THE INVENTION 
   One of the more common afflictions to affect aging eyes are cataracts, which cause gradually deteriorating vision. Advances in ophthalmic surgery allow many cataracts to be removed and vision restored. 
   Treating cataracts typically involves the removal of the clouded natural lens and replacement with an artificial lens. Removal of the lens requires an incision or tunnel to be made in and/or adjacent to the cornea. The tip portion of a phaco emulsifier is inserted through the incision and vibrates ultrasonically to liquefy the lens. The emulsified lens is removed from the lens capsule by aspiration. Modern aspirators also perform irrigation. I/A instruments have dual passages, one for irrigation and the other for aspiration. Usually the passages are coaxial, the inner passage being formed by a rigid or semi-rigid cannula, and the outer passage having a distal portion formed by a sleeve which may be resilient. One or more components of the tips are removable from the handpiece of the instrument for selection of an appropriate or desired tip, and for replacement of the tip. 
   SUMMARY OF THE INVENTION 
   The present invention provides a connector or adapter that allows an I/A handpiece of one design to receive tip components of different designs. For example, an  I/A handpiece of one manufacturer may be designed with a connection system to receive tip components of that manufacturer. By use of the present invention, the handpiece may be used with tip components of another manufacturer, from an I/A system having a different interconnection with a handpiece. Therefore, the user need not rely on the availability of I/A tips having connection systems specifically designed for a particular I/A handpiece. Rather, if desirable features are available from other manufacturers, the present invention allows such tips to be reliably fitted on existing handpieces. 
   In representative embodiments, connectors or adapters in accordance with the present invention may have a proximate stem adapted for a sliding friction fit with a handpiece, and a distal end designed for a threaded interconnection with an aspiration tip. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein: 
       FIG. 1  (Prior Art) is a top perspective of a known I/A instrument with parts shown in exploded relationship; 
       FIG. 2  (Prior Art) is a corresponding top perspective of the instrument of  FIG. 1  with parts assembled and shown in section; 
       FIG. 3  (Prior Art) is an enlarged, fragmentary, perspective detail of the proximate end portion of the known instrument of  FIGS. 1 and 2 ; and 
       FIG. 4  (Prior Art) is an enlarged, fragmentary, perspective detail of the distal end portion of the known instrument of  FIGS. 1 and 2 . 
       FIG. 5  (Prior Art) is a top perspective of a second known I/A instrument with parts shown in exploded relationship; 
       FIG. 6  (Prior Art) is a top perspective corresponding to  FIG. 5 , but with parts assembled and shown in section; 
       FIG. 7  (Prior Art) is an enlarged, fragmentary, perspective detail of the proximate end portion of the known instrument of  FIGS. 5 and 6 ; and 
       FIG. 8  (Prior Art) is an enlarged, fragmentary, perspective detail of the distal end portion of the known instrument of  FIGS. 5 and 6 . 
       FIG. 9  is a perspective of an I/A instrument having a connector in accordance with the present invention, with parts shown in exploded relationship; and  FIG. 9A  is an enlarged end elevation of the connector.  
       FIG. 10  is a perspective corresponding to  FIG. 9 , but with the parts assembled and shown in section. 
       FIG. 11  is an enlarged, fragmentary, perspective detail of the proximate end portion of the instrument of  FIG. 9  and  FIG. 10 , with the parts shown in section; and 
       FIG. 12  is an enlarged, fragmentary, perspective detail of the distal end portion of the instrument of  FIGS. 9 and 10 , including the connector in accordance with the present invention, with the parts shown in section. 
       FIG. 13  is a perspective of an I/A instrument having a connector in accordance with the present invention, with parts shown in exploded relationship; and  FIG. 13A  is an enlarged end elevation of the connector. 
       FIG. 14  is a perspective corresponding to  FIG. 13 , but with the parts assembled and shown in section. 
       FIG. 15  is an enlarged, fragmentary, perspective detail of the proximate end portion of the instrument of  FIG. 13  and  FIG. 14 , with the parts shown in section; and 
       FIG. 16  is an enlarged, fragmentary, perspective detail of the distal end portion of the instrument of  FIGS. 13 and 14 , including the connector in accordance with the present invention, with the parts shown in section. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1–4  illustrate a first type of known I/A device D designed for use during cataract surgery.  FIG. 1  shows three primary components in exploded relationship, namely, a handpiece  10  having a proximate end portion  12  and distal end portion  14 , an I/A tip  16  having a proximate stem portion or hub  18  for insertion into the distal end portion  14  of the handpiece and a distal aspiration cannula  20 , and a sleeve  22  insertable over the cannula  20  for dispersing irrigation liquid. These components are shown assembled and in longitudinal section in  FIG. 2 .  FIGS. 3 and 4  are enlarged perspectives of the proximate and distal end portions, respectively, with the parts shown in section. 
   As best seen in  FIG. 3 , the proximate end portion  12  of the handpiece  10  includes a hollow hub  24  forming an aspiration port  26  for connection to a vacuum source, and a hollow inclined branch  28  forming an aspiration port  30  for connection to a source of irrigation liquid. Port  26  communicates with the long and straight central aspiration bore  32  of the instrument that extends longitudinally thereof all the way to the distal end portion  14  of the instrument shown in  FIG. 4 . Similarly, port  30  communicates with an annular channel  34  that encircles the bore  32  and is separated therefrom by a cylindrical wall  36 . As seen in  FIG. 4 , wall  36  terminates at a distal end  38  which is recessed with respect to the distal end  40  of the outer wall  42  of the handpiece. Such handpiece outer wall includes several segments which combine to define the outer periphery of the irrigation channel  34 .  
   Still referring to  FIG. 4 , the hub  18  of the I/A tip  16  includes a proximate portion  44  that fits snugly within the distal end portion of the cylindrical wall  36  of the handpiece and is sealed therein by a friction fit. A more distal portion  46  of the hub  18  is sized and designed to fit within the distal end portion of the handpiece outer wall  42 . The I/A tip is manually insertable into and removable from the handpiece, the friction fit seals being achieved by O-rings  48  and  50 . The cannula  20  of the I/A tip  16  is formed by a thin walled tube that extends lengthwise through the hub  18 , including a proximate portion  52  which is secured within the proximate portion  44  of the hub and which communicates with an axial bore  54  that opens into the aspiration passage  32  of the handpiece. Thus, reduced pressure applied at the end port  26  is conveyed by way of aspiration passage  32  and bore  54 , through the central bore  56  of the cannula  20 , all the way to one or more ports located at the distal end portion  58  of the cannula. 
   The sleeve  22  includes a hub portion  62  that connects to the distal end portion  60  of the I/A tip  16 . For example, these parts can connect by a threaded fit. The distal portion  64  of the sleeve surrounds the cannula  20  and has one or more end or side ports for ejecting irrigation liquid. Such liquid flows through the irrigation port  30  and annular passage  34 , then inward through side ports  66  of the hub  18  to a smaller annular passage  68  around the cannula  20 . Passage  68  opens into the sleeve  22  so that irrigation liquid is free to flow through the distal portion  64  of the sleeve for ejection through the end or side ports. 
   A second known type of I/A device D′ is illustrated in  FIGS. 5–8 , which correspond to  FIGS. 1–4 . The primary difference between device D′ and device D is that device D′ includes a bayonet latch for connecting the I/A tip  16  to the distal end portion  14  of handpiece  10 . Such latch consists of pins  70  that project from the stem portion or hub  18  of the I/A tip  16  and fit within contoured slots  72  of the handpiece. Thus, a more positive lock of the I/A tip in the handpiece is provided. In other respects,  the structure and functioning of the bayonet latch I/A tip is the same as for the tip previously described. With reference to  FIGS. 7 and 8 , suction applied at the handpiece end port  26  is conveyed by way of the axial bore  32  through the bore  56  of the cannula  20  to one or more end or side ports at the distal end or end portion  58 . Irrigation liquid supplied through the inclined branch  28  is conveyed by way of the proximate port  30  and annular passage  34  to the side ports  66  of the hub  18 , to the smaller annular passage  68  alongside the cannula. From there the irrigation liquid flows through the sleeve  22  to an end and/or side port in the cylindrical distal sleeve segment  64  that surrounds the cannula. 
   Devices D and D′ correspond to I/A instruments available from MicroSurgical Technology, Inc., of Redmond, Wash. 
     FIGS. 9–12  illustrate a first embodiment of the present invention that enables tips of other manufacturers, such as specialized tips available from Alcon Laboratories, Inc., of Fort Worth, Tex., to be used with handpieces D of the type shown in  FIGS. 1–4  (a second embodiment of the present invention allows such specialized aspiration tips to be used with handpieces D′ of the type shown in  FIGS. 6–8 ). 
   With reference to  FIGS. 9–12 , handpiece  10  and sleeve  22  are identical to the corresponding parts shown and described with reference to  FIGS. 1–4 . Aspiration tip  80  is of the construction used by Alcon Laboratories. Such tip includes a hollow, long, straight distal portion or cannula  82 , an externally threaded hub  84 , and an intermediate hub  86  which may have flat sides adapted for reception in a wrench-like instrument used to rotate the tip for coupling it to an Alcon Laboratories handpiece. 
   In accordance with the present invention, a special connector  88  is provided which has a proximate stem portion or hub  90  coupled to the Microsurgical Technologies handpiece  10 , and a distal portion  92  for coupling to the Alcon Laboratories aspiration tip  80  and the conventional irrigation sleeve  22 . These parts are shown assembled and in longitudinal cross-section in  FIG. 10 .  FIGS. 11 and 12  are enlarged perspectives of the proximate and distal portions, respectively, of the modified instrument using the connector  88 , with parts shown in section. 
   With reference to  FIG. 11 , the proximate end portion  12  of the handpiece  10  is identical to that previously described. In  FIG. 11 , the branch  28  containing the  irrigation port is positioned away from the viewer but communicates with the annular irrigation passage  34 . 
   With reference to  FIG. 12 , the distal end portion  14  of the handpiece  10  includes the outer wall  42  terminating at its distal end  40  and the inner wall  36  terminating at its distal end  38 . The inner wall  36  defines the central aspiration bore  32 . The annular space  34  between the inner wall  36  and outer wall  42  defines the passage for irrigation liquid. 
   Connector  88 , manually separable from the handpiece, in accordance with the present invention, has a proximate stem portion or hub  94  of a first diameter sized to fit snugly within the distal end portion of the inner wall  36 . Moving distally, connector  88  includes a second stem portion or hub  96  that fits snugly within the distal end portion of the outer wall  42 . O-rings  100  and  102  provide tight, sealing, friction fits. A central aspiration tube  104  has a proximate end portion secured in the first connector hub  94 . A shoulder  107  limits the insertion of the connector into the handpiece by engagement against the distal end  40  of the outer wall  42 . An annular chamber  106  is formed around the central portion of the aspiration tube  104 , communicating with the irrigation passage  34  by way of one or more side ports  108 . The narrow annular irrigation passage  106  opens distally into a wider chamber  110 . This chamber is generally cylindrical and can be machined into the body of the connector from its distal end. A tapered insert  112  is secured in the chamber  110 , with a central aspiration bore  114  communicating with the aspiration tube  104 . The distal portion of the aspiration chamber  114  is enlarged and has internal threads that mate with external threads of the hub  84  of the aspiration tip  80 . Thus, the aspiration tip  80 , such as a tip designed for an Alcon Laboratories device, can be coupled to the connector  88 , similar to the coupling of such a tip to an Alcon Laboratories handpiece. The distal end portion  116  of the insert  112  is not circular, but has an outer periphery with one or more openings that communicate with the irrigation liquid chamber  110  (this aspect is seen in  FIGS. 9 and 9A ). For example, in a preferred embodiment, the distal end portion of the insert  112  can be square, providing several flat sides  118  spaced inward from the body of the connector  88  to form passages for the flow of irrigation liquid therethrough. Such liquid passes to the interior of the sleeve  22 , which can couple to the distal end portion of the connector, such as by a threaded fit. 
     FIGS. 13–16  correspond to  FIGS. 9–12 , respectively, illustrating a second embodiment of connector  88 ′ that will couple to a MicroSurgical Technologies handpiece  10  of the type described above with reference to  FIGS. 5–8  (the bayonet latch handpiece). Other than the shape of the central portion, the provision of latch pins  120 , and dimensioning to fit the modified handpiece, the construction of connector  88 ′ is identical to the construction of connector  88 , previously described, and like parts are numbered the same in  FIGS. 13–16  as for the embodiment of  FIGS. 9–12 . With reference to  FIG. 16 , connector  88 , manually separable from the handpiece, has the narrower proximate stem portion or hub  94  sized to fit snugly within the distal end portion of the inner wall  36 . The second stem portion or hub  96  fits snugly within the distal end portion of the outer wall  42 . O-rings  100  and  102  provide tight, sealing, friction fits. The proximate end portion of the central aspiration tube  104  is secured in the first connector hub  94 . Shoulder  107  limits the insertion of the connector  88 ′ into the handpiece  10  by engagement against the distal end  40  of the outer wall  42 . Annular chamber  106  is formed around the central portion of the aspiration tube  104 , communicating with the irrigation passage  34  by way of one or more side ports  108 . The narrow annular irrigation passage  106  opens distally into the larger chamber  110 . The tapered insert  112  is secured in the chamber  110 , with the central aspiration bore  114  communicating with the aspiration tube  104 . The distal portion of the aspiration chamber  114  is enlarged and has internal threads that mate with external threads of the hub  84  of the aspiration tip  80 . Thus, the separate aspiration tip  80 , such as a tip designed for an Alcon Laboratories device, can be coupled to the connector  88 ′. The distal end portion  116  of the insert  112  has the outer periphery with one or more openings that communicate with the irrigation liquid chamber  110 , as seen in  FIGS. 13 and 13A . For example, the distal end portion of the insert  112  can be square, providing the several flat sides  118  spaced inward from the body of the connector  88 ′ to form passages for the flow of irrigation liquid therethrough. Such liquid passes to the interior of the sleeve  22 , which can couple to the distal end portion of the connector, such as by a threaded fit.  
   While the preferred embodiments of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention.