Abstract:
A phacoemulsification needle has tip geometries configured to operate efficiently in both the longitudinal and torsional modes. In one variation, the needle tip has a sharpened edge formed on at least a portion of the needle lip. In other variations the lip geopmetry is selected to create cutting surfaces in both the torsional and longitudinal directions.

Description:
PRIORITY  
       [0001]    This application claims priority from U.S. Patent Application Ser. No. 61/080,681, filed Jul. 14, 2008, entitled “Phacoemulsification Needle Tips”, which is incorporated herein in its entirety by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]    This disclosure relates to surgical instruments and surgical techniques used in eye surgery and more particularly, to phacoemulsification apparatus and methods for their use. 
       BACKGROUND OF THE INVENTION  
       [0003]    A common ophthalmological surgical technique is the removal of a diseased or injured lens from the eye. Earlier techniques used for the removal of the lens typically required a substantial incision to be made in the capsular bag in which the lens is encased. Such incisions were often on the order of 12 mm in length. 
         [0004]    Later techniques focused on removing diseased lenses and inserting replacement artificial lenses through as small an incision as possible. For example, it is now a common technique to take an artificial intraocular lens (IOL), fold it and insert the folded lens through the incision, allowing the lens to unfold when it is properly positioned within the capsular bag. Similarly, efforts have been made to accomplish the removal of the diseased lens through an equally small incision. 
         [0005]    One such removal technique is known as phacoemulsification. A typical phacoemulsification tool includes a handpiece to which is attached a hollow needle. Electrical energy is applied to vibrate the needle at ultrasonic frequencies in order to fragment the diseased lens into small enough particles to be aspirated from the eye through the hollow needle. Commonly, an infusion sleeve is mounted around the needle to supply irrigating liquids to the eye in order to aid in flushing and aspirating the lens particles. 
         [0006]    It is extremely important to properly infuse liquid during such surgery. Maintaining a sufficient amount of liquid prevents collapse of certain tissues within the eye and attendant injury or damage to delicate eye structures. As an example, endothelial cells can easily be damaged during such collapse and this damage is permanent because these cells do not regenerate. One of the benefits of using as small in incision as possible during such surgery is the minimization of leakage of liquid during and after surgery and the prevention of such a collapse. 
         [0007]    Phacoemulsification needles and tips are well represented in the prior art. Needles and tips of varying configurations are well known. A particular shape for a tip or needle is often dictated by the type of handpiece with which the needle is to be used. 
         [0008]    U.S. Pat. No. 5,788,679 (Gravlee, Jr.) teaches and describes a phacoemulsification needle having a sharpened edge formed at the tip by cutting the needle tip at an angle to form bevels. The resulting needle is not a straight needle and the needle must be held at an angle to bring portions of the cutting edge into contact with the nucleus or other tissue to be treated. This needle configuration appears to be suitable for a handpiece using linear or longitudinal motion but not for one using torsional motion. 
         [0009]    United States Patent Application Publication 2006/0217672 (Chon) teaches and describes a phacoemulsification tip that is swaged or crimped at its distal end. The tip is intended for use with a handpiece producing torsional motion and the crimping forms cutting edges at the distal end. 
         [0010]    U.S. Pat. No. 5,725,495 (Strukel et al) teaches and describes a phacoemulsification handpiece, sleeve and tip illustrating a wide variety of tip configurations and needle cross-sectional configurations. 
         [0011]    U.S. Pat. No. 6,007,555 (Devine) teaches and describes an ultrasonic needle for surgical emulsification. The needle and its tip are shown in both circular and oval configurations. 
         [0012]    U.S. Pat. No. 6,605,054 (Rockley) teaches and describes a multiple bypass port phaco tip having multiple aspiration ports and a single discharge port to infuse liquid into the eye. 
         [0013]    U.S. Pat. No. 5,879,356 (Geuder) teaches and describes a surgical instrument for crushing crystalline eye lenses by means of ultrasound and for removing lens debris by suction which demonstrates the use of a sleeve positioned concentric to the needle and having a pair of discharge ports formed thereon. 
         [0014]    U.S. Pat. No. 5,645,530 (Boukhny) teaches and describes a phacoemulsification sleeve, one variation of which has a bellows portion attached to a discharge port ring which directs an annular flow of liquid around the needle and into the eye. The use of the bellows is intended to allow the sleeve to absorb spikes in liquid pressure during the operation. 
         [0015]    Published United States Patent Application No. 2003/0004455 (Kadziauskas) teaches and describes a bi-manual phaco needle using separate emulsification and aspiration needles inserted into the eye simultaneously during surgery.. 
         [0016]    U.S. Pat. No. 6,077,285 (Boukhny) teaches and describes a torsional ultrasound handpiece configured to impart both longitudinal and torsional motion to a phacoemulsification needle. 
         [0017]    U.S. Pat. No. 6,402,769 (Boukhny) is a continuation in part of the &#39;285 patent and further particularizes the frequencies at which the crystals providing both the torsional and longitudinal motion are activated. 
         [0018]    I have determined that improved results can be achieved if the lip of a straight phacoemulsification needle tip is formed in a variety of differing configurations. In particular, certain of these configurations provide lips with varying degrees of sharpness for use in different phaco procedures. I have also determined that the selected configurations can also be used with angled tips. I have also determined that varying configurations provide advantages for phacoemulsification needles used with both linear and torsional hand pieces. Such tips are intended to be of particular value when used with handpieces capable of generating both longitudinal and torsional motion, or a blend of such motions. 
         [0019]    In accordance with these criteria, I have designed a series of phacoemulsification needle tips having shaped lips whose configuration is selected by the task to be performed. 
         [0020]    While the following describes an example or examples of the present invention, it is to be understood that such description is made by way of example only and is not intended to limit the scope of the present invention. It is expected that alterations and further modifications, as well as other and further applications of the principles of the present invention will occur to others skilled in the art to which the invention relates and, while differing from the foregoing, remain within the spirit and scope of the invention as herein described and claimed. Where means-plus-function clauses are used in the claims such language is intended to cover the structures described herein as performing the recited functions and not only structural equivalents but equivalent structures as well. For the purposes of the present disclosure, two structures that perform the same function within an environment described above may be equivalent structures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0021]    These and further aspects of the present invention will be best understood by reference to the accompanying drawings wherein: 
           [0022]      FIG. 1  is a drawing showing prior art oval and square-shaped tips; 
           [0023]      FIG. 2  is a drawing showing several prior art needle cross-sectional configurations; 
           [0024]      FIG. 3  is a lateral sectional view of a prior art needle tip; 
           [0025]      FIG. 4  is a perspective view of the needle tip of  FIG. 3 ; 
           [0026]      FIG. 5  is a lateral schematic sectional view of a prior art needle tip; 
           [0027]      FIG. 6  is an enlarged view of the tip of  FIG. 5 ; 
           [0028]      FIG. 7  is a schematic view of the tip of  FIG. 5  used with a longitudinal hand piece; 
           [0029]      FIG. 8  is a schematic view of the tip of  FIG. 5  used with a torsional hand piece; 
           [0030]      FIG. 9  is a partial schematic sectional view of a tip embodying certain principles of the present invention; 
           [0031]      FIG. 10  is an enlarged view of the portion of the tip of  FIG. 9 ; 
           [0032]      FIG. 11  is a schematic view of the tip of  FIG. 9  used with a hand piece having longitudinal motion; 
           [0033]      FIG. 12  is a schematic view of the tip of  FIG. 9  used with a hand piece having torsional motion; 
           [0034]      FIG. 13  is a partial schematic sectional view of another embodiment of the present invention; 
           [0035]      FIG. 14  is an enlarged view of a portion of the tip of  FIG. 13 ; 
           [0036]      FIG. 15  is a schematic view of the tip of  FIG. 13  used with a hand piece having longitudinal motion; 
           [0037]      FIG. 16  is a schematic view of the tip of  FIG. 13  used with a hand piece having torsional motion; 
           [0038]      FIG. 17  is a partial schematic sectional view of another embodiment of the present invention; 
           [0039]      FIG. 18  is an enlarged view of a portion of the tip of  FIG. 17 ; 
           [0040]      FIG. 19  is a schematic view of the tip of  FIG. 16  used with a hand piece having longitudinal motion; 
           [0041]      FIG. 20  is a schematic view of the tip of  FIG. 17  used with a hand piece having torsional motion; 
           [0042]      FIG. 21  is a partial schematic sectional view of another embodiment of the present invention; 
           [0043]      FIG. 22  is an enlarged view of a portion of the tip of  FIG. 21 ; 
           [0044]      FIG. 23  is a schematic view of the tip of  FIG. 21  used with a hand piece having longitudinal motion; 
           [0045]      FIG. 24  is a schematic view of the tip of  FIG. 21  used with a hand piece having torsional motion; 
           [0046]      FIG. 25  is a partial schematic sectional view of another embodiment of the present invention; 
           [0047]      FIG. 26  is an enlarged view of a portion of the tip of  FIG. 26 ; 
           [0048]      FIG. 27  is a partial sectional view of another embodiment of the present invention; 
           [0049]      FIG. 28  is is a partial sectional view of another embodiment of the present invention; 
           [0050]      FIG. 29  is a partial sectional view of another embodiment of the present invention; 
           [0051]      FIG. 30  is a partial sectional view of another embodiment of the present invention; 
           [0052]      FIG. 31  is a partial sectional view of another embodiment of the present invention; 
           [0053]      FIG. 32  is a partial sectional view of another embodiment of the present invention; 
           [0054]      FIG. 33  is a partial sectional view of another embodiment of  FIG. 33 ; and 
           [0055]      FIG. 34  is a partial sectional view of another embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0056]    It is common for some in the art to refer to an entire phacoemulsification needle as a “tip”. For the purposes of the description that follows, the word “tip” shall refer to that portion of a phacoemulsification needle that is proximate the end of the needle that contacts the tissue to be emulsified. The portion of the needle extending from the tip to the needle mount shall be referred to as the “needle body”. 
         [0057]    Referring now to  FIG. 1 , the numeral  10  indicates generally a prior art phacoemulsification needle tip as shown in U.S. Pat. No. 6,007,555. Needle  10  terminates in a mouth  12  defined by a lip  14  at the end of needle body  16 , with lip  14  and needle body  16  formed as having an oval cross-section configuration. 
         [0058]    Referring to  FIG. 1 , the numeral  18  indicates generally a prior art phacoemulsification needle tip from U.S. Pat. No. 6,007,555, having a mouth  20  defined by a lip  22  at the end of needle  24 . The cross-sectional configuration of needle  18  and mouth  20  is a rectangle. 
         [0059]    Referring now to  FIG. 2 , the numeral  26  identifies several prior art phacoemulsification needles as described in U.S. Pat. No. 5,725,495, with needle  28  having a circular cross-section as shown at  30 , needle  32  having a triangular cross-section as shown at  34  and needle  36  having an octagonal cross-section as shown at  38 . 
         [0060]    Referring now to  FIG. 3 , the numeral  40  indicates generally a partial sectional view of a prior art phacoemulsification needle tip shown and described in U.S. Pat. No. 5,788,679. Needle tip  40  has a side wall  42  having an inner surface  44  terminating at mouth  50 . As seen in  FIG. 3 , mouth  50  is formed at angle β with respect to axis  52  forming a trailing edge  54  and a leading edge  56  as seen in  FIG. 3 . As further seen, leading edge  56  is formed with a bevel  58  formed at an angle α to inner surface  44 . This appears to result in at least a portion of leading edge  56  formed with a somewhat sharpened edge. As seen in  FIG. 4 , the portion of edge  56  shown is the flat or blunt portion  60  of trailing edge  54 . As seen in  FIG. 3  edges  54  and  56  define needle mouth  62 . 
         [0061]    Referring now to  FIG. 5 , the numeral  64  identifies a prior art phacoemulsification needle tip having been formed as part of needle body  66  with an enlarged tapered section  68  terminating in a tip  70  having straight walls extending parallel to axis  72 . As seen in  FIG. 5  and more particularly in  FIG. 6 , tip portion  70  terminates at a lip  74  which defines the tip mouth  76  with lip  74  formed substantially perpendicular to axis  72 . 
         [0062]    Referring to  FIG. 7 , the use of tip  64  is illustrated on a hand piece providing longitudinal motion meaning that tip  70  is moved, alternatively, in the directions indicated by arrows A and B. As seen in this illustration, such motion provides tip  64  with an effective cutting zone  78  extending generally about the periphery of lip  74 . In my experience, such a configuration tends to repulse nucleus  80  in a direction away from cutting zone  78  making it more difficult to apply an emulsification force to nucleus  80 . 
         [0063]    Referring now to  FIG. 8 , the use of tip  64  in a hand piece providing torsional motion is shown, meaning that the handpiece imparts an alternating rotational motion to a phacoemulsification needle attached to the handpiece is rotated repetitively in a clockwise direction and a counterclockwise direction imparting an eccentric or “torsional” motion to the needle tip, such as tip  64 . This results in the creation of an exterior cutting zone  82  and an interior cutting zone  84  extending about the inner and outer peripheries of tip  70 , a configuration which provides less efficient cutting when tip  70  is used to cut nucleus  86 . 
         [0064]    Throughout, the use of arrows A and B in an illustration will identify movement of the tip in the longitudinal direction by the handpiece to which the phacoemulsification needle is mounted. Throughout, the use of arrows C and D in an illustration will identify movement of the tip in the torsional direction by the handpiece to which the phacoemulsification needle is mounted. 
         [0065]    Referring now to  FIG. 9 , the numeral  88  identifies a tip configuration embodying certain of the principles of the present invention. Needle  88  terminates in a tip  90  having an outer wall  92  and an inner wall  94  which, in turn, terminates at a lip  96 . As seen in greater detail in  FIG. 10 , lip  96  is formed at an angle to outer wall  92  to form a sharpened and continuous tip edge  98  surrounding tip mouth  100 . 
         [0066]    As seen in  FIG. 11 , the configuration of tip  90  creates an effective cutting zone  102  extending about the outer periphery of lip  96  when tip  90  is used in a longitudinal motion. Cutting zone  102  is believed to extend inwardly along a portion of lip  96  and along a portion of the outer surface  92  extending downwardly from edge  98 . It is expected that such a configuration will result in diminished repulsion of nucleus  104  during the phacoemulsification process. 
         [0067]    Referring now to  FIG. 12 , tip  90  is shown used with a handpiece having torsional motion. It is expected that tip  90 , when used with a hand piece having torsional motion will create an effective cutting zone  102   a  which will increase the efficiency of tip  90  when cutting nucleus  104 . 
         [0068]    Referring now to  FIGS. 13 and 14 , another embodiment of the present invention is shown with needle tip  106  having an outer wall  108  and an inner wall  110  terminating at a lip  112  and defining a tip mouth  114 . 
         [0069]    As seen in  FIG. 14 , tip  112  terminates in a cutting edge  116  formed by beveling a first portion  118  of outer surface  108  and a second portion  120  of inner surface  110  to intersect and form cutting edge  116 . Tip  106  therefore terminates in an outer beveled surface  188  and an inner beveled surface  120 . 
         [0070]    As seen in  FIG. 15 , it is expected that tip  106  will create an effective cutting zone  122  when used with a hand piece having longitudinal motion and that such a configuration will reduce the tendency of nucleus  124  to be repulsed by the motion of tip  106 . 
         [0071]    Referring now to  FIG. 16 , tip  106  is shown as used with a hand piece having torsional motion and it is expected that the configuration of tip  106  will create an effective cutting zone  122   a  along edge  116  and will result in more efficient phacoemulsification of nucleus  124 . 
         [0072]    Referring to  FIG. 17  another embodiment of the present invention is illustrated with tip  126  having an outer wall  128 , and an inner wall  130  terminating at lip  132 . As seen in greater detail in  FIG. 18 , lip  132  is formed with a step-like configuration having an outer lip portion  134  extending generally perpendicular to axis  136  and terminating intermediate outer wall  128  and inner wall  130 . Tip  132  is further characterized by an inner wall portion  138  extending downward in a direction generally parallel to axis  136 . Wall portion  138  terminates at a point distal from tip portion  134  at an inwardly-extending wall portion  140  in a direction generally toward and perpendicular to axis  136 , thereby forming tip land  142 , which is defined by wall portions  138 ,  140  and which extends between wall portion  138  and inner wall  130 . In this embodiment, land  142  is formed generally or substantially perpendicular to axis  136 . It should be understood that the angle of wall portion  140  and land  142  with respect to  136  may be altered to create different cutting characteristics for tip  126 . 
         [0073]    Referring now to  FIG. 19 , the use of tip  126  is shown with a hand piece having longitudinal motion. It is expected that tip  126  will create an effective cutting zone  144  which will reduce the tendency of tip  126  to repel nucleus  146  thus resulting in more efficient phacoemulsification. It is expected that the creating of cutting zone  144  results from the motion of outer tip edge  148  and inner tip edge  150  as shown in  FIG. 19 . 
         [0074]    Referring now to  FIG. 20 , use of tip  126  is shown with a hand piece having torsional motion. It is expected that this configuration will create and effective cutting zone  144   a  which will increase the efficiency of the cutting of nucleus  146 . 
         [0075]    Referring to  FIG. 21  another embodiment of the present invention is illustrated with tip  152  having an outer wall  154 , and an inner wall  156  terminating at lip  158 . As seen in greater detail in  FIG. 22 , lip  158  is formed with a step-like configuration having an outer lip portion  160  extending generally perpendicular to axis  162  and intermediate outer wall  154  and inner wall  156 . Tip  132  is further characterized by an outer lip portion  164  extending downward in a direction generally parallel to axis  162 . Outer lip portion  164  terminates in a point distal from lip  158  to form an outwardly-extending wall portion  166  in a direction generally perpendicular to axis  164 , thereby forming external tip land  168 , which is defined by wall portions  164 ,  166  and which extends between outer lip portion  164  and outer wall  154 . In this embodiment, land  168  is formed generally or substantially perpendicular to axis  162 . It should be understood that the angle of outer lip portion  164  and land  168  with respect to axis  162  may also be altered to create different cutting characteristics for tip  152 . 
         [0076]    Referring now to  FIG. 23 , the use of tip  152  is shown with a hand piece having longitudinal motion. It is expected that tip  152  will create an effective cutting zone  170  which will reduce the tendency of tip  152  to repel nucleus  172  thus resulting in more efficient phacoemulsification. It is expected that the creating of cutting zone  170  results from the formation of outer lip portion  160  and outwardly-extending wall portion  166  as shown in both  FIGS. 22 and 23 . 
         [0077]    Referring now to  FIG. 24 , use of tip  152  is shown with a hand piece having torsional motion. It is expected that this configuration will create and effective cutting zone  174   a  which will increase the efficiency of the cutting of nucleus  172 . 
         [0078]    Referring now to  FIG. 25 , another embodiment of the present invention is illustrated by needle tip  176  having outer surface  178  and inner surface  180  with said inner and outer surfaces terminating at lip  182  defining a mouth  184 . 
         [0079]    Referring now to  FIG. 26 , tip  176  is shown in greater detail. Lip  176  is shown having a radiused cross-sectional shape formed by a curvilinear surface  178  extending from outer surface  178  to inner surface  180 . This configuration provides a single, continuous, relatively smooth and blunt cutting surface which, it is expected, will be more desirable for surgical situations in which relatively thin or sensitive tissue, such as the posterior capsule, may be contacted during emulsification. The added protection is useful with both longitudinal and torsional motion. 
         [0080]    The foregoing examples have shown straight tip configurations, that is, where the lip defining the mouth lies generally in a plane perpendicular to the tip&#39;s longitudinal axis. It is also expected that the foregoing tip configurations will be effective if the lip is angled with respect to the longitudinal axis and the tip configurations described above are formed thereon. 
         [0081]    Referring now to  FIG. 27 , the numeral  182  identifies a tip having an angled lip  184  configured substantially as shown in  FIGS. 9-12 . Lip  184  defines a mouth  186 . Cutting edge  188  corresponds to cutting edge  98  in  FIG. 10 . As seen, lip  184  is beveled with respect to tip wall  190 , creating a leading edge  192  and a trailing edge  194  of cutting edge  188 . 
         [0082]    Referring now to  FIG. 28 , the numeral  196  identifies a tip having an angled lip  198  configured substantially as shown in  FIGS. 13-16 . Lip  198  is formed by tapered wall segments  200 ,  202  of tip wall  204 . As seen, lip  198  is angled with respect to tip wall  204  creating a leading edge  206  and a trailing edge  208 . 
         [0083]    Referring now to  FIG. 29 , the numeral  210  identifies a tip having an angled lip configured substantially as shown in  FIGS. 17-20 . Tip  210  has a lip  212  defining a mouth  214 . Lip  212  is formed with an internal step configuration  216  having a first axial wall segment  218  and a second radial wall segment  220  forming a step with a configuration such as that shown in  FIG. 18 . As seen in  FIG. 29 , lip  212  is beveled or angled with respect to tip wall  222  forming a leading edge  224  and a trailing edge  226 . 
         [0084]    Referring now to  FIG. 30 , the numeral  228  identifies a tip configured substantially as shown in  FIGS. 21-24 . Tip  228  has a lip  230  which defines mouth  232  and which has a first, axially extending segment  234  formed proximate lip  230  and a second, generally radially extending segment  236  contiguous to segment  234  to form the external steps as seen in  FIG. 22 . As seen in  FIG. 30 , lip  230  is angled with respect to tip wall  238  creating a leading edge  240  and a trailing edge  242 . 
         [0085]    Referring now to  FIG. 31 , the numeral  244  identifies an angled tip configured substantially as shown in  FIGS. 26-27 , having an angled lip  246  defining a mouth  248 . As seen in  FIG. 31 , lip  246  is rounded at its endmost portion  250  in the manner shown in  FIG. 26 . Lip  246  is also angled with respect to tip wall  252  to form an angled configuration with a leading edge  254  and a trailing edge  256 . 
         [0086]    Referring now to  FIG. 32  the numeral  258  identifies a tip having a lip  260  defining a mouth  262 . Lip  260  has a lip segment  264  extending from tip wall  266  partially into mouth  262 . Lip segment  264  has a first, radial lip surface  268  extending into mouth  262 , a second, axial lip surface  270  depending from surface  266  and a third, radial surface  272  extending from surface  268  to tip wall  266 . 
         [0087]    In the embodiment shown, axial surface  270  is beveled to create an edge  274  which acts as a cutting edge. In like fashion, third lip surface  272  may be flat or may be beveled to form an edge  276 , each of which acts as a cutting surface. 
         [0088]    Referring now to  FIG. 33  the numeral  278  identifies a tip constructed in accordance with the description of tip  262  shown in  FIG. 32 . In this embodiment, tip  278  is formed at an angle E to needle body  280 . 
         [0089]    Referring now to  FIG. 34 , a tip  282  is shown in partial cross-section, having a lip  284  defining a mouth  286 . Lip  284  has a lip segment  288  extending from tip wall  290  partially into mouth  286 . Lip segment  288  has a first, radial lip surface  290  extending into mouth  286 , a second, axial lip surface  292  depending from surface  290  and a third, radial surface  294  extending from surface  292  to tip wall  296 . 
         [0090]    In the embodiment shown, first lip surface  290  is formed with a smoothed, rounded or polished surface, while axial surface  292  is beveled to create an edge  298  which acts as a cutting edge. In like fashion, third lip surface  294  is beveled to form an edge  300  which acts as a cutting edge. First lip surface  290  helps protect delicate eye tissue from damage during phacoemulsification. 
         [0091]    The foregoing descriptions are made with the understanding that the configuration of the tip is flared, that is, the tip is larger than the phacoemulsification needle body. It is expected that straight phacoemulsification needles having no enlargement or flare at the tip will also benefit from the application of the principles of the present invention. 
         [0092]    The foregoing descriptions are also made with the understanding that the tips may be either straight or angled with respect to the needle body and can be used with handpieces having either longitudinal or torsional motion, and are expected to be more efficient when the tips are angled with respect to the needle body.