Abstract:
An apparatus provides mechanical energy to vibrate a needle. An irrigating sleeve is disposed around the needle and includes one or more irrigation ports through which irrigation liquid is ejected during emulsification. To prevent the needle from occluding the irrigation ports with its deflections, one or more bumpers are provided between the sleeve and the needle.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority to and is a continuation-in-part of U.S. application Ser. No. 14/197,295 filed Mar. 5, 2014, now pending, which claims priority to U.S. Provisional application Ser. No. 61/773,998 filed Mar. 7, 2013, now ______, all incorporated herein by reference in its entirety. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    A. Field of Invention 
         [0003]    This invention pertains to an apparatus for performing phacoemulsification using a handpiece including a hollow needle used to pulverize the lens and a sleeve surrounding the needle. Irrigating liquid is injected into the anterior chamber from the sleeve. The sleeve is provided with a plurality of bumpers arranged to minimize deflections of the needle during the emulsification process thereby minimizing obstruction of infusion fluid from the exit ports in the sleeve. 
         [0004]    B. Description of the Prior Art 
         [0005]    Phaco-emulsification is a procedure used to break up and remove the natural lens from the capsular bag within the eye of a person. Most often the procedure is used as a means of treating a person having cataracts. The procedure involves making a small incision in the eye and introducing through the incision a thin hollow needle having a central passage. A circumferential sleeve surrounds the needle. The needle is coupled to an ultrasonic generator that vibrates the needle in a predetermined (preferably ultrasonic) frequency range causing the natural lens to fragment and emulsify. Irrigation fluid enters the anterior chamber of the eye through two or more ports formed in the outer sleeve surrounding the needle. Detritus resulting from the phaco-emulsification process mixes together with the liquid and is aspired through the central passage in the needle. The liquid used for irrigation also produces a stabilizing effect in the anterior and posterior chambers, keeping the eye inflated. 
         [0006]    To complete the operation, an intraocular lens implant is then inserted into the capsular bag (usually through the same incision). 
         [0007]    While the technology has for the most part been broadly accepted as the community norm, the present inventor has discovered several disadvantages in the presently available equipment used for phaco-emulsification. It is preferable to have the liquid used for irrigation ejected evenly from ports to insure a relatively smooth, non-turbulent and non-violent fluid flow within the anterior chamber. However the present inventor has discovered that during phaco-emulsification, the needle deflects considerably within the sleeve frequently occludes or blocks one of the ports on the sleeve (at least partially). As a result, since the pressure within the sleeve is fairly constant, the flow of the liquid through one of the ports is reduced temporarily by the deflected needle, the flow through the other port(s) increases suddenly, In other words, while one port is at least partially blocked by the needle, the liquid through the other port is ejected at a greater volume and velocity. This effect is undesirable since it can cause detritus resulting from the phaco-emulsification to be pushed away from the aspiration tip and toward the furthest corners of the anterior chamber, occasionally transporting unwanted lens material to the back of the eye. Additional problems may also occur as a result of uneven liquid flow through the ports. The present invention addresses this problem. It should be understood that during emulsification, the needle deflection changes continuously during emulsification, and it blocks one of the ports only for fractions of a second—often alternating rapidly from one side of the sleeve to the other. 
       SUMMARY OF THE INVENTION 
       [0008]    An apparatus is disclosed that includes a sleeve with one or more ports for ejecting irrigation liquid into the eye of a patient. The apparatus also includes a needle disposed nominally concentrically within the sleeve. The needle is vibrated to provide emulsification. It has been found that the needle deflects in a somewhat random manner by manipulation by the surgeons as it is being vibrated and that, as it deflects, it occludes the ports in the distal sleeve causing undesirable variations in the flow of the irrigation liquid into the eye. In order to prevent, or at least reduce this effect, one or more bumpers are provided between the sleeve and the needle. In one embodiment the bumpers are provided on the inside surface of the sleeve. The heights of the bumpers can be constant or various bumpers can have differing heights. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1A  shows a block diagram of an apparatus for performing phaco-emulsification constructed in accordance with this invention; 
           [0010]      FIG. 1B  shows an enlarged side view of the sleeve of the apparatus of  FIG. 1A ; 
           [0011]      FIG. 2A  shows a cross-sectional view of the sleeve of  FIG. 1A ; 
           [0012]      FIG. 2B  shows an enlarged view of a port of the sleeve of  FIG. 2A  through which a liquid is ejected during a phaco-emulsification process, in accordance with this invention; 
           [0013]      FIG. 2C  shows an enlarged cross-sectional view of the sleeve and the needle taken through the ports of the sleeve; 
           [0014]      FIG. 3A  shows a side orthogonal view of an alternate embodiment of the invention; and 
           [0015]      FIG. 3B  show an enlarged cross-sectional view of the sleeve of  3 A. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0016]    Referring first to  FIGS. 1A ,  1 B,  2 A,  2 B and  2 C an apparatus  100  constructed in accordance with this invention includes a handle  10  that includes a vibrating mechanism  12  and is connected to a fluid source  14  and a vacuum source  16 . 
         [0017]    One end of the handle  10  is provided with a horn  18  terminating with a needle assembly  20  including a sleeve  22  surrounding a hollow needle  24 . The needle assembly  20  narrows toward its tip as shown at  26 . The sleeve  22  is formed with several ports  28 . In the Figures two such ports  28  are shown disposed diametrically opposite each other. 
         [0018]    As is typical in any phaco-emulsification apparatus, the vibration mechanism  12  produces selectively a mechanical vibration at a predetermined frequency (for example, at either a sonic, e.g. 40-400 Hz or ultrasonic, e.g. 30-60 KHz, frequency range). This vibration is transmitted through the horn  18  to the needle  24  in a known manner. The vibrating needle  24 , when inserted into the anterior chamber of the eye (not shown) emulsifies or pulverizes the lens (not shown) in the anterior chamber. At the same time, irrigation fluid (typically a saline solution) from fluid source  14  passes through the sleeve  22  cooling the needle  24  and exiting through ports  28 . The central passageway  25  in needle  24  is in communication with vacuum source  16 . The irrigation fluid with the detritus left over the emulsification of the lens is aspired from anterior chamber through the central passageway  25  in the needle  24  in the conventional manner. 
         [0019]    Referring now to  FIGS. 2A ,  2 B,  2 C a problem with existing phaco-emulsification devices is that the needle disposed concentrically within the sleeve  22  (not omitted in  FIGS. 2A ,  2 B for the sake of clarity) deflects in use and blocks at least partially ports  28 . In order to prevent this phenomenon, a plurality of bumpers  30  are provided, preferably on the inner surface  32  of sleeve  22 . The bumpers are made of the same material as the sleeve  22 . Therefore the sleeve  22  can be made by molding or other known processes with the bumpers  30  being made integrally therewith. Preferably the bumpers  30  have a generally conical shape, although they can be other similar shapes as long as their dimension in the axial directional and circumferential direction are approximately the same. 
         [0020]    In one embodiment, several rows of bumpers  30  are provided on the inner wall  32  of sleeve  22 , positioned so as to limit the deflections of needle  24 . Each row of bumpers is positioned at a predetermined axial location on sleeve  22 . For example, row of bumpers  30 A is disposed just slightly up stream of ports  28 . Each set may include two, three or four bumpers disposed at equal angles around the inner circumference of sleeve  22 . For example, the tip  26  of a typical sleeve may have the following dimensions (in inches): 
         [0021]    Outer diameter 0.054 
         [0022]    Thickness 0.004±0.002 
         [0023]    Port  28  0.0056×0.0037 
         [0024]    Height of bumpers  30  0.008 
         [0025]    Distance of row of bumpers  30 A from ports  28  0.010 
         [0026]    Distance between bumper rows 0.050 
         [0027]    It should be understood that these dimensions are provided only for illustrative purposes and are not meant to be interpreted as limitations. 
         [0028]    Preferably, the rows of bumpers are arranged so that they are angularly offset from each other by 90 degrees. This arrangement is believed to be effective in controlling and limiting the deflection of needle  22 . Moreover, the bumpers  30  constructed and arranged to insure that they do not interfere with the flow of the irrigation fluid through the sleeve. In other words, the bumpers are sized so that their effect on the overall cross-sectional area of the sleeve  22  is minimal and hence the sleeve  22  can have a normal or nominal size. If the bumpers are too large, or there are too many bumpers, the effective cross-sectional area of the sleeve  22  is reduced and a larger sleeve  22  would have to be used to make sure that the proper amount of irrigation liquid is provided to the anterior chamber. 
         [0029]    As mentioned above, a problem addressed by the present invention is that during emulsification, the needle  24  tends to deflect away from its concentric position within the sleeve  22  to the point where it occludes or blocks at least partially one of the ports  28 —leading to sudden changes in the flow of irrigation fluid from the ports. 
         [0030]    However, in the sleeve  22  shown this problem is at least diminished because the deflections of the needle  24  are minimized and therefore undesirable radial oscillations of the needle  24  are minimized by bumpers  30 . For example, as shown in  FIG. 2C , normally needle  24  is disposed coaxially within the sleeve  22 . However, during emulsification, the needle  24  deflects from its normal coaxial position, for example by deflecting towards port  28 A, as indicated at  24 A. However, this deflection is limited by the bumper  30 AA disposed adjacent to port  28 A to limit or reduce blocking of the port  28 A. 
         [0031]      FIGS. 3A and 3B  show an alternate embodiment of the invention in which the sleeve  122  has a somewhat different shape then sleeve  22 . However the sleeve  120  is still formed with ports  128  and bumpers  130  arranged in rows. Importantly, as can be seen in  FIG. 3A , the bumpers  130  are formed in circumferential rows that are staggered in circumferential direction. 
         [0032]    In this embodiment, the bumpers  130  have a generally cylindrical shape. 
         [0033]    Importantly, the height of each bumper  30 , i.e., its dimension in the radial direction is selected so that when needle  124  is disposed perfectly concentrically within the sleeve  122 , as seen in  FIG. 3B , there is a minimum distance d between each of the bumpers  130  and the needle  124 . As in the previous embodiment, the reason for this feature is to insure that when the needle  124  is not deflected, e.g., when it is a neutral or coaxial position, as shown in  FIG. 3B , it does not touch any of the bumpers  130 . This feature insures that the sleeve  122  and the bumpers  130  do not interfere with, and attenuate the movement of the needle  124  required to perform effective phaco-emulsification. At least one bumper or a row of bumpers  130 C is disposed between one of the ports  128  and the end of the sleeve  135 . 
         [0034]    In one embodiment, the distance d is constant for all the bumpers  130 . Moreover the cross-sectional dimensions of all the bumpers  130  can be the same as well. In another embodiment, the dimension d and/or the cross-sectional dimension(s) of the bumpers  130  can be different. For example, bumpers  130  closer to the port  128  can be larger. In another embodiment, the dimension d and/or the cross-sectional dimension(s) of the bumpers can be smaller for bumpers closer to the ports  128 . The choice as to whether the change these dimensions or not depends on the deflection characteristics of the needle and the amount of ballooning of sleeve  122 . 
         [0035]    In the above discussion, it has been assumed that the needle is made of titanium or other biologically inert rigid material, and that the sleeve is made of a silicone or other similar, rather flexible material that can be shaped to include the bumpers described above. Of course, the bumpers can also be placed on an outer surface of the needle, as shown at  30 X in  FIG. 3C . In either case the bumpers are arranged and constructed to control the lateral deflection of the needle. 
         [0036]    Obviously numerous modifications may be made to this invention without departing from its scope as defined in the appended claims.