Abstract:
Phacoemulsification needle tips are provided with emulsifying surfaces enhancing their capacity to emulsify eye tissue when used with phaco handpieces that vibrate such needles torsionally. In one version, prongs are formed on the tip proximate the tip mouth and are bent to be positioned to provide additional emulsifying surfaces in both needle rotational directions. In another version, additional emulsifying surfaces are formed on the interior of the tip or the needle.

Description:
PRIORITY 
       [0001]    This application claims priority from U.S. provisional patent application Ser. No. 60/862,985, filed Oct. 26, 2006 and entitled “Phacoemulsification Needle Tip for Torsional Motion”, and Ser. No. 60/886,930, filed Jan. 28, 2007 and entitled “Phacoemulsification Needle Tip with Interior Cutting Surfaces”, both of which are hereby 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 needle tip designs for use with handpieces that produce torsional motion. 
       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. 5,725,495 (Strukel et al) teaches and describes a phacoemulsification handpiece, sleeve and tip illustrating a wide variety of tip configurations and needle cross-sectional configurations. 
         [0009]    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. 
         [0010]    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. 
         [0011]    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. 
         [0012]    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. 
         [0013]    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. 
         [0014]    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. 
         [0015]    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. 
         [0016]    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. 
         [0017]    I have determined that improved results can be achieved using high-speed handpieces in both the longitudinal and torsional direction if the phacoemulsification tip is provided with a particular geometry. I have also determined that these improved results can be achieved using the straight phacoemulsification needle configuration, a configuration which is favored by a considerable number of doctors. 
         [0018]    In accordance with these criteria, I have designed a series of tips that are specifically configured to enhance the emulsifying defect created by the handpiece in the torsional direction. In addition, the improved results are anticipated with the use of handpieces providing longitudinal motion. 
         [0019]    In accordance with an example of the invention, a phacoemulsification needles is provided for use with a high-frequency torsional phacoemulsification handpiece with the needle having a series of prongs formed on the tip proximate the tip opening. 
         [0020]    In a second example, the prongs extend over or into the tip opening. 
         [0021]    In another example, the tip prongs are formed with curved outer surfaces. 
         [0022]    In another example, the tip prongs have selected edges that are sharpened or beveled. 
         [0023]    In another example, the prongs are bent or formed at different angles. 
         [0024]    In accordance with another example of the invention, a phacoemulsification needle is provided for use with a high-frequency phacoemulsification handpiece with the needle tip having a series of individually-cutting or emulsifying surfaces formed on the interior of the tip and extending longitudinally within the tip. 
         [0025]    In another example, the tip is formed from a planar sheet of titanium and rolled into a “spiral” configuration within the tip interior. 
         [0026]    In another example, the tip opening is formed at different angles. 
         [0027]    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 
         [0028]    These and further aspects of the present invention will be best understood by reference to the accompanying drawings wherein: 
           [0029]      FIG. 1  is a drawing showing prior art oval and square-shaped tips; 
           [0030]      FIG. 2  is a drawing showing several prior art needle cross-sectional configurations; 
           [0031]      FIG. 3  is a partial lateral schematic sectional view of a tip having prongs formed at about a right angle to the tip wall; 
           [0032]      FIG. 4  is a view along  4 - 4  of  FIG. 3 ; 
           [0033]      FIG. 5  is a partial schematic sectional view of a phaco tip having internal tip prongs that extend inward and curve downward; 
           [0034]      FIG. 6  is a view along  6 - 6  of  FIG. 5 ; 
           [0035]      FIG. 7  is a partial schematic sectional view of a tip having prongs that curve downward and inward; 
           [0036]      FIG. 8  is a view along  8 - 8  of  FIG. 7 ; 
           [0037]      FIG. 9  is a partial schematic sectional view of a tip having a square opening with prongs extending inward from the lip at about a 90 degree angle; 
           [0038]      FIG. 10  is a view along  FIG. 10-10  of  FIG. 9 ; 
           [0039]      FIG. 11  is a partial schematic sectional view of a square tip having prongs that extend inward and curve downward; 
           [0040]      FIG. 12  is a view along  12 - 12  of  FIG. 11 ; 
           [0041]      FIG. 13  is a top plan view of a tip having prongs that curve outward and upward; 
           [0042]      FIG. 14  is a partial schematic view taking along  14 - 14  of  FIG. 13 ; 
           [0043]      FIG. 15  is a top plan view of a tip showing  8  prongs curving upward and outward; 
           [0044]      FIG. 16  is a top plan view of a tip having four foreshortened prongs; 
           [0045]      FIG. 17  is a perspective view of the tip of  16 ; 
           [0046]      FIG. 18  is a top plan view of a tip having two inwardly extending prongs and two inward and downwardly extending prongs; 
           [0047]      FIG. 19  is a partial schematic sectional view of a tip having two downwardly and two inwardly extending prongs and two inwardly extending prongs; 
           [0048]      FIG. 20  is a partial schematic sectional view of a tip having two outwardly extending and curving prongs and two inwardly and extending curving prongs; 
           [0049]      FIG. 21  is a top view of a tip combining a pair of inwardly extending prongs, a pair of inward and downwardly extending prongs and a pair of outwardly curving prongs; 
           [0050]      FIG. 22  is a partial perspective view of a straight phaco tip having a circular cross-section; 
           [0051]      FIG. 23  is a partial perspective view of a tip of  FIG. 22  showing areas along the tip edge of the tip marked for removal; 
           [0052]      FIG. 24  shows the various areas in  FIG. 23  having been removed; 
           [0053]      FIG. 25  shows the remaining prongs folded over in the configuration of  FIG. 4 ; 
           [0054]      FIG. 26  is an end view of a tip constructed in accordance with a preferred embodiment of the present invention; 
           [0055]      FIG. 27  is a partial lateral sectional view of the tip shown in  FIG. 26  with a beveled configuration; 
           [0056]      FIG. 28  is a schematic view of a sheet of metal from which a second embodiment of the invention is formed; 
           [0057]      FIG. 29  is an end view of the tip formed from the sheet in  FIG. 5 ; and 
           [0058]      FIG. 30  is a lateral elevational view of the tip of  FIG. 6  illustrating several preferred bevels. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0059]    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. 
         [0060]    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. 
         [0061]    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 . 
         [0062]    Also shown in  FIG. 2  is a central axis A extending down the length of needle  28 . For the purposes of the following description, each phacoemulsification tip described herein is formed as a part of a needle shaft having a similar, centrally-located axis no matter the cross-sectional shape of the needle shaft. 
         [0063]    Referring now to  FIG. 3 , the numeral  40  indicates generally a phacoemulsification needle tip embodying certain aspects of the present invention. In this example, tip  40  is circular in cross section as seen in  FIG. 4  and has an outer wall  42  having an outer surface  44  and an inner surface  46 . As seen in  FIG. 4 , tip  40  also has a lip  48  extending about tip mouth  50 . As described above, an axis A is shown in  FIG. 3  and it should be understood that axis A is a reference point defined by the center of the phacoemulsification needle N upon which tip  40  is formed. 
         [0064]    In the example shown in  FIGS. 3 and 4 , tip  40  has four internally extending tip projections or prongs  52  formed at about a 90 degree angle with outer wall  42  and extending into and partially across mouth  50 . Preferably, prongs  52  are formed integrally with outer wall  42  at lip  48 . 
         [0065]    Referring now to  FIGS. 5 and 6 , tip  40  is shown having four prongs  54  which extend inwardly across and then curve downwardly into mouth  50 . For the purposes of this description, the prong that extends at approximately a right angle to outer wall  42  will be referred to as inwardly projecting, a prong which extends into mouth  50  from outer wall  42  will be described as downwardly projecting, and a prong which extends at an angle greater than 90 degrees without outer wall  42  will be described as upwardly projecting. 
         [0066]    In  FIG. 5 , each prong  54  is shown having a first, inwardly projecting segment  56  and a second, downwardly curving and projecting segment  58 . Prongs  54  are preferably formed integrally with tip  40  at lip  60 . 
         [0067]    Referring now to  FIGS. 7 and 8 , tip  40  is shown having four identically formed prongs  62  in arcuate shapes. As seen in  FIG. 7 , prong  62  extends integrally with and from outer wall  42  to curve upward and then downward toward or into mouth  50 . Lip  64  extends around the periphery of mouth  50  intermediate prongs  62 . 
         [0068]    Referring now to  FIGS. 9 and 10 , a square tip  66  has an outer wall  68  and four identically formed and inwardly extending prongs  70 . As described above, prong  70  are preferably formed integrally with outer wall  68  at lip  72  which, with outer wall  68  defines mouth  74 . 
         [0069]    Referring now to  FIGS. 11 and 12 , square tip  66  is shown having four identically formed prongs  76  with each prong  76  having a first inwardly extending segment  78  and a second downwardly curving segment  80 . Prongs  76  are preferably formed integrally with outer wall  68  at lip  82 . 
         [0070]    The foregoing examples have all been shown with four prongs. It should be understood and appreciated that any number of prongs in any desired spacing may be utilized as desired. For example, 3, 6 or 8 prongs may also be used. The selection of the number of prongs will reside more with the predicted or observed efficiency of the tip when used with a torsional handpiece. For example, it may be more efficacious to have the prongs equidistantly spaced no matter how many prongs are used to balance the tip. 
         [0071]    Referring to  FIG. 13 , a top plan view is shown of a circular tip  84  having four curved and upwardly extending prongs  86 . The prongs are formed integrally with tip  84  at lip  88  and extend upwardly from lip  88  curving inwardly to extend over mouth  90 . 
         [0072]    As seen in  FIG. 14 , each prong  86  has an arcuate outer surface  92 . As seen in  FIGS. 13 and 14 , each prong  86  is separated from its adjacent neighbor by a groove or bight  94  and extends upward from lip  88 . 
         [0073]    Referring now to  FIG. 15 , a second example of tip  84  is shown with 8 prongs  96  formed thereon. Each prong extends upwardly from and is integral with lip  98  and each is separated by a groove or bight  100 . 
         [0074]    Referring now to  FIG. 16 , a circular tip  102  has formed thereon four curved and upwardly extending prongs  104  formed integrally with and extending upwardly from lip  106 . Prongs  104  are foreshortened when compared to prongs  86 ,  96 , leaving a wider access to mouth  108 . Each prong  104  in  FIG. 16  has a first edge  110  and a second edge  112  meeting at an apex  114 . If desired, apex  114  may be rounded. Such a configuration is shown in perspective in  FIG. 17  showing in greater detail the geometry of each prong  104 . 
         [0075]    It is another feature of the present invention to provide prongs such as those hereinabove described in not only varying sizes and shapes but, in some instances, with edges that are honed, beveled or otherwise sharpened. 
         [0076]    For example, referring to  FIG. 17 , edges  110  and  112  together with apex  114  may be sharpened or beveled. In  FIG. 13 , edges  166 ,  168 ,  170  of prong  86  may also be sharpened, if desired. The decision to hone or sharpen a selected edge of a selected prong again depends upon the use to which the tip is to be put, the type of handpiece, the feel of the tip so constructed and the preference of the surgeon 
         [0077]    Referring now to  FIG. 18 , the numeral  116  identifies a tip having four prongs formed thereon with prongs  118 ,  120  substantially identical to prongs  52  as shown in  FIG. 4  and with prongs  122 ,  124  substantially identical to prongs  54  as shown in  FIGS. 5 and 6 . In this manner, one may take advantage of the different cutting characteristics of each such prong. The prongs are shown in  FIG. 18  as equidistantly spaced with identical prongs positioned directly opposite one another. It is also possible to intermix these prongs again depending upon the preferences of the user, and with consideration paid to the balance, feel and operation of the handpiece being used. 
         [0078]    Referring now to  FIG. 19  another example of a circular tip  126  is shown having prongs  128 ,  130  formed thereon substantially identical to prongs  54  shown in  FIGS. 5 and 6 , but extending downwardly into mouth  134 . A second pair of prongs  136  and  138  (not shown) are formed on tip  126  again diametrically opposed and equidistantly spaced with prongs  136 ,  138  substantially identical to prong  52  and extending at approximately a right angle to wall  138  of tip  126 . 
         [0079]    Referring now to  FIG. 20 , a tip  140  is shown in cross-section having a pair of curved outwardly extending prongs  142 ,  144  formed thereon and a second pair of curved prongs  146 ,  148  (not shown) curved inwardly and downwardly into mouth  150 . 
         [0080]    Referring now to  FIG. 21 , the number  152  identifies a tip combining a first pair of prongs  154 ,  156  constructed to extend inwardly as shown with respect to prong  52  in  FIGS. 3 and 4 , a second set of prongs  158 ,  160  extending inwardly and downwardly as shown at prong  54  in  FIGS. 5 and 6 , and a third pair of prongs  162 ,  164  extending and curving upwardly and inwardly as seen in at prong  104  in  FIG. 17 . 
         [0081]    Referring now to  FIG. 22  the numeral  166  identifies a round, straight phacoemulsification tip prior to the formation of prongs as described above. Tip  166  has an outer wall  168  and a lip  170  proximate mouth  172 . 
         [0082]    Referring to  FIG. 23 , tip  166  is shown with lines  174  setting off wall segments  176  to be cut or otherwise removed as a step toward making a tip such as that depicted in  FIGS. 3 and 4 . In this example, four such segments  176  are so marked. 
         [0083]      FIG. 24  illustrates the configuration of tip  166  after segments  176  have been severed and removed, leaving upstanding tabs or prongs  178  extending upward from and integral with tip  166  at lip  170 . 
         [0084]    In  FIG. 25 , tip  166  is shown with prongs  178  bent inward to an angle of about 90° with wall  168  at lip  170  to overlap mouth  172 . Tip  166  is now complete. 
         [0085]    It should be understood that the process described in connection with  FIGS. 22-25  can also be used to form prongs with configurations as described hereinabove. 
         [0086]    Referring now to  FIG. 26 , the numeral  180  indicates generally a phacoemulsification needle tip embodying certain aspects of the present invention. In this example, tip  180  is circular in cross section and has an outer wall  182  terminating at one end in a lip  184  which defines a tip opening  186 . A central cavity  188  extends from tip opening  186  in a rearward or longitudinal direction as seen also in  FIG. 27 . 
         [0087]    As seen in  FIGS. 26 and 27 , tip  180  terminates at a hollow needle body  190  having a central passageway  192 , corresponding to the needle passageway N described earlier, which communicates with cavity  188  and tip opening  186  to form a flow path for fluid and emulsified tissue removed from a patient&#39;s eye. 
         [0088]    As seen in  FIG. 26  the interior surface  194  of wall  182  is formed in a “scalloped” cross-sectional configuration with a series of semi-circular sections  196  meeting at flattened peaks  198  to form a series of longitudinally-extending flattened ridges  200 . For the purposes of this description, a “scallop” is understood to be that portion of interior surface  194  extending upward to and downward from a flattened peak  198 . 
         [0089]    As seen laterally in  FIG. 27 , each section  196  and each peak  198  extend longitudinally along the interior of tip  180  parallel to central axis B of tip  180 , forming a series of longitudinally-extending ridges  200  extending into cavity  188 . 
         [0090]    The surfaces of semi-circular sections  196  form emulsifying or “cutting” surfaces when tip  180  is rotated in a torsional direction about axis B and will emulsify tissue along the interior of tip  180 . 
         [0091]    Referring now to  FIG. 28 , the numeral  202  identifies a generally rectangular sheet of material thin enough and stiff enough to be suitable for the construction of a phacoemulsification tip. One example of such a material is titanium. Sheet  202  has a lateral edge  204 , a first longitudinal edge  206  and a second longitudinal edge  208 . 
         [0092]    As seen in  FIG. 29 , a phacoemulsification needle  210  is formed by rolling sheet  202  into a right cylindrical spiral configuration, with first longitudinal edge  206  attached to sheet  202  at seam  214  and with second longitudinal edge  208  remaining free and extending longitudinally along the length of tip  210 . The spiral formed by sheet  202  thus has a “tail”  212  that terminates at second longitudinal edge  208  at one end and is attached to tip  210  at seam  212  at the other end. Tail  212  has an “inner” surface  216  and an “outer” surface  218 . When tip  210  is used with a torsional handpiece, surfaces  216 ,  218  form “cutting” or emulsifying surfaces when tip  210  is rotated clockwise and counterclockwise as viewed in  FIG. 29 . 
         [0093]    Referring now to  FIG. 30 , tip  210  is shown in a lateral elevation. Tip  210  is formed in a straight configuration when lip  220  is unbeveled. When lip  220  is formed along cut line  222  tip  210  has a 30° bevel, and when formed along cut line  224  has a 45° bevel. 
         [0094]    It is expected that others skilled in the art will determine that other manufacturing processes and techniques can also be used to form the tip examples described and claimed herein.