Abstract:
A phacoemulsification needle uses a variety of tip shapes to increase efficiency during surgery. In several variations the tips are angled with respect to the needle body. Inb others, various cross-sectional shapes are used. Angling the tip opening is another configuration used.

Description:
PRIORITY 
       [0001]    This application claims priority from application Ser. No. 60/704,556, filed Aug. 2, 2005, application Ser. No. 60/725,129, filed Oct. 8, 2005 and application Ser. No. 60/754,450, filed Dec. 28, 2005, all of which are incorporated herein 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. 
         [0008]    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. 
         [0009]    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. 
         [0010]    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. 
         [0011]    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. 
         [0012]    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. 
         [0013]    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. 
         [0014]    Published U.S. 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. 
         [0015]    Known phacoemulsification needles and tips are designed for use with handpieces that vibrate the needle longitudinally at relatively low frequencies. In addition to longitudinal vibration, the NeoSoniX handpiece has a rotational or torsional oscillation vibration frequency of about 100 cycles/second. There is a new generation of handpiece that provides torsional oscillation of the phacoemulsification tip at frequencies of about 32,000 cycles/second. At such higher oscillation rates there is reduced sticking of nuclear fragments at the aspiration port. However, to be effective at such higher oscillation rates a phacoemulsification needle tip must be relatively light as compared to present tips while still providing a sufficiently large surface and aspiration port to efficiently emulsify and aspirate fragments of the nucleus. 
         [0016]    I have determined that good results can be achieved using high-speed handpieces if the phacoemulsification tip is made to be lighter by changing the shape of the tip and removing portions of the tip material. I have also determined that better results are achieved if the tip is angled with respect to the needle axis. I have also determined that roughening the exterior surface of the tip enhances the emulsification effect. 
         [0017]    In accordance with these criteria I have designed a series of tips that are reduced in weight without sacrificing size and have included specially roughened surfaces to enhance the emulsifying effect created by the torsional handpiece. Such tips and tip design criteria can be used for handpieces that combine the torsional and longitudinal vibratory motion. 
         [0018]    While the following describes a preferred embodiment or embodiments 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. 
         [0019]    In accordance with a preferred embodiment of the apparatus a phacoemulsification needle is provided for use with a high-frequency torsional phacoemulsification handpiece with the needle having a needle tip angled with respect to the longitudinal axis of the needle and which has an oval cross-section and mouth communicating with the hollow passage formed through the needle. 
         [0020]    In a second preferred embodiment, the exterior surfaces of the tip are roughened while the mouth of the tip is polished to a mirror finish. 
         [0021]    In yet another embodiment of the present invention, the tip is formed in a “catfish” configuration wherein portions of the tip extending from the tip mouth are removed. 
         [0022]    In yet another embodiment of the present invention, the tip is formed as a section of a sphere with opposed faces of the sphere flattened and roughened while the remaining portions of the tip are mirror polished. 
         [0023]    In yet another embodiment the tip is formed with a triangular cross-section and at least one of the triangle sides is polished while the remaining side(s) are roughened. 
         [0024]    In yet another embodiment the tip is flattened and has an elliptical cross-section and mouth. 
         [0025]    In yet another embodiment the tip is formed with a generally squared-off or rectangular cross-section. 
         [0026]    In yet another embodiment the tip is formed coaxially with the needle body and has a generally flattened shape. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0027]    These and further aspects of the present invention will be best understood by reference to the accompanying drawings wherein: 
           [0028]      FIG. 1  is a drawing showing prior art oval- and square-shaped tips; 
           [0029]      FIG. 2  is a drawing showing several prior art needle cross-sectional configurations; 
           [0030]      FIG. 3  is a lateral view of a phacoemulsification needle embodying the present apparatus; 
           [0031]      FIG. 4  is a lateral detail of the needle shown in  FIG. 3 ; 
           [0032]      FIG. 5  is an end view of the mouth of the needle tip shown in  FIG. 4 ; 
           [0033]      FIG. 6  is a partial sectional view along line  6 - 6  of  FIG. 5 ; 
           [0034]      FIG. 7  is a partial elevational view of a second embodiment of the needle and tip; 
           [0035]      FIG. 8  is a view along  8 - 8  of  FIG. 7 ; 
           [0036]      FIG. 9  is a partial elevational view of a third embodiment of the needle and tip; 
           [0037]      FIG. 10  is a view along  10 - 10  of  FIG. 9 ; 
           [0038]      FIG. 11  is a partial elevational view of a fourth embodiment of the needle and tip; 
           [0039]      FIG. 12  is a view along line  12 - 12  of  FIG. 11 ; 
           [0040]      FIG. 13  is a partial elevational view of a fifth embodiment of the needle and tip; 
           [0041]      FIG. 14  is a view along line  14 - 14  of  FIG. 13 ; 
           [0042]      FIG. 15  is a partial elevational view of a sixth embodiment of the needle and tip; 
           [0043]      FIG. 16  is a partial elevational view of a seventh embodiment of the needle and tip; 
           [0044]      FIG. 17  is a view along line  17 - 17  of  FIGS. 15 and 16 ; 
           [0045]      FIG. 18  is a partial elevational view of a prior art high-frequency tip; 
           [0046]      FIG. 19  is a view along line  19 - 19  of  FIG. 18 ; 
           [0047]      FIG. 20  is a partial elevational view of an eighth embodiment of the needle and tip; and 
           [0048]      FIG. 21  is a view along line  21 - 21  of  FIG. 20 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0049]    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. 
         [0050]    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. 
         [0051]    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 . 
         [0052]    Referring now to  FIG. 3 , the numeral  40  indicates generally a phacoemulsification needle embodying certain aspects of the present invention. Needle  40  has a mount  42  enabling it to be attached to a phacoemulsification handpiece (not shown). Needle  40  has an elongate body  44  extending from mount  42  and terminating in a needle tip  46 . As is common with phacoemulsification needles of this type, a hollow passageway is formed extending from mount  42  through tip  46  and is used to aspirate emulsified lens fragments during surgery 
         [0053]    Referring now to  FIG. 4 , an enlarged view of tip  46  is shown. Tip  46  is offset from the axis  48  of body  44  by a tip-body offset angle A, preferably about 10-15°. 
         [0054]    As seen in  FIG. 4 , tip  46  is flared and somewhat bell-shaped and has a mouth  50  defined by a lip  52 . Mouth  50  is best seen in  FIG. 5 . Tip  46  has a tip body  54  comprising the outer surface of tip  46  extending from lip  52  to where tip  46  meets body  44 . 
         [0055]    As seen in  FIG. 4 , tip body  54  is preferably somewhat flattened and preferably foreshortened with lead edge  56  being longer than trailing edge  58  and with lead edge  56  meeting lip  52  at an angle B, preferably about 65°. As seen in  FIG. 5 , mouth  50  is generally oval in shape as is lip  52 . 
         [0056]    As seen in  FIG. 6 , a portion  60  of lip  52  is polished to a mirror finish to allow lip  52  and thereby tip  46  to pass through an incision without snagging the incised tissue. 
         [0057]    The mirror polishing of lip  52  also provides added protection against the rupture of the posterior capsule of the eye should tip  52  come in contact therewith. 
         [0058]    Referring now to  FIGS. 4 and 6 , a portion  62  of tip body  54  is roughened, as by sandblasting or the like, to enhance the emulsification effect of needle  46  during the phacoemulsification process. 
         [0059]    In a preferred embodiment and as seen in  FIGS. 4  ad  5 , tip  46  is about 1.5 mm along its longest dimension while, as seen in  FIG. 5 , mouth  50  is about 1.8 mm at its major axis D and 1.0 mm at its minor axis C, with a wall thickness of about 0.1 mm. As seen in  FIGS. 4 and 5 , major axis D lies generally in or parallel to a plane that includes tip  46 , body  44  and angle A. This will be referred to as the “tip-body” plane. As also seen in  FIG. 4  mouth  50  is also angled laterally in the tip-body plane at a head-offset angle E of about 25°. 
         [0060]    When used in phacoemulsification, mouth  50 , as the terminus of the hollow channel formed through needle  40  allows lens and other tissue fragments created by the phacoemulsification process to be aspirated through needle  40 . 
         [0061]    Referring now to  FIG. 7 , the numeral  66  identifies generally a phacoemulsification needle tip having an outer surface  68  terminating in a lip  70 . As seen in  FIG. 8 , lip  70  and outer surface  68  define an oval mouth  72  as described above in connection with the first preferred embodiment. As described above, tip  66  has a a tip-body offset angle A 2 , preferably about 10-15° and a head offset angle E 2  of about 25°. 
         [0062]    Referring now to  FIG. 8 , a pair of lateral ports  74 ,  76  are formed opposite one another and extending through tip  66 . As described hereinabove, lip  70  is mirror polished while the outer surface  68  is roughened by sandblasting. 
         [0063]    Referring now to  FIG. 9 , a third embodiment of the present invention is shown wherein the numeral  80  identifies a needle tip. As described above, tip  80  has a a tip-body offset angle A 3 , preferably about 10-15°. Tip  80  terminates in a rounded body  84  having a pair of opposed, curved sides  86 ,  88  and a pair of opposed flattened sides  90 ,  92  as illustrated in  FIG. 10 . Sides  86 ,  88 ,  90  and  92  terminate in and form a lip  94  extending about a circular mouth  96 . As described hereinabove, surfaces  90 ,  92  are roughened while curved surfaces  86 ,  88  are mirror polished. 
         [0064]    Referring now to  FIG. 11 , the numeral  98  identifies a phacoemulsification tip extending from needle body  100 . As described above, tip  98  has a a tip-body offset angle A 4 , preferably about 10-15° and a head offset angle E 4  of about 25°. Tip  98  terminates at a lip  102  which, as described above, is mirror-polished. Tip outer surface  104  is roughened, as by sandblasting or the like and has a pair of opposed cut-outs  106 ,  108  formed thereon. As seen in  FIG. 12 , each cutout  106 ,  108  begins at lip  102  and extends along tip  98  toward body  100 . Tip  98  is thereby lightened by the material removed to form cutouts  106 ,  108  while retaining the rigidity needed for tip  98  to function. 
         [0065]    Referring now to  FIG. 13 , the numeral  110  identifies a phacoemulsification tip extending from needle body  112  . As described above, tip  110  has a a tip-body offset angle A 5 , preferably about 10-15° and a head offset angle E 5  of about 25°. As seen in  FIG. 14 , tip  110  is triangular in cross-sectional configuration, terminating in a lip  114  and having sidewalls  116 ,  118  and  120 , each of which preferably taper upward towards body  112 . In the embodiment shown, the outer surface of sidewall  120  is mirror-polished, while the outer surfaces of sidewalls  116  and  118  are roughened as described above. 
         [0066]    In  FIGS. 15 ,  16  and  17  phacoemulsification tips embodying the present invention are shown having flattened profiles. In  FIG. 15 , tip  122 , as described above, has a a tip-body offset angle A 6 , preferably about 10-15° and a head offset angle E 6  of about 25°. 
         [0067]    In  FIG. 17 , tip  126  is coaxial with body  128 . Tips  122 ,  126  are formed with a flattened oval-type configuration as seen in  FIG. 17 , with lip segments  130 ,  132  generally parallel to each other, and with lip segments  134 ,  136  generally parallel to each other to form a “racetrack-like” mouth  138 . As described above, the outer surfaces of tips  122 ,  126  are roughened, and lip segments  130 ,  132 ,  134  and  136  are mirror-polished. 
         [0068]    Referring now to  FIG. 18  a known high-frequency needle  146  is shown having a tip  148 , a body  150  and a mouth  152 . As described above, tip  146  has a head offset angle E 7  of about 25°. Tip  148  and body  150  are “coaxial”, meaning that there is little or no tip-body offset angle. In addition, as seen in  FIG. 19 , mouth  152  is a round opening. 
         [0069]    Referring to  FIG. 20 , an additional embodiment of the present apparatus is shown wherein needle  154  has a a tip-body offset angle A 8 , preferably about 10-15 and a head offset angle E 8  of about 25° Needle  154  has a tip  156  terminating in a mouth  158  which, as seen in  FIG. 21  has a generally rectangular shape with opposed walls  160  being longer in dimension than opposed walls  162 . As seen in  FIG. 20 , walls  160  are in the “tip-body” plane, meaning that the longer dimensions of mouth  158  are generally parallel to the bend formed by the head offset angle. 
         [0070]    Angling the head appears to maximize the phacoemulsificiation effect created by the high-frequency handpieces described above and it appears that an angle of 10-15° produces very satisfactory results, with larger angles used for relatively smaller or lighter heads, while the smaller angles are used with relatively larger or heavier heads. Larger heads with larger mouth openings create the most efficient results. 
         [0071]    While the tip configurations depicted herein generally show each non-circular tip mouth positioned to place either a major or minor axis parallel to the tip-body plane it is also contemplated that either such axis can lie in a plane that is at an angle to the tip-body plane.