Patent Publication Number: US-2017354493-A1

Title: Protective cap for an insertion device and other insertion device features

Description:
CROSS-REFERENCE TO RELATED PATENTS AND APPLICATIONS 
     This application claims priority to and is a divisional of U.S. application Ser. No. 13/818,573, filed Feb. 25, 2014, which is a U.S. National Phase of PCT Application No. PCT/US2011/049029, filed Aug. 24, 2011, which claims priority to U.S. Provisional Application Nos. 61/376,661, filed on Aug. 24, 2010; 61/467,584, filed on Mar. 25, 2011; and 61/500,564, filed on Jun. 23, 2011, all of which are hereby incorporated by reference in their entirety. 
    
    
     TECHNICAL FIELD OF THE INVENTION 
     The present invention relates to an inserter protective cap and other inserter features. 
     BACKGROUND OF THE INVENTION 
     It is estimated that 73% of Americans between the ages of 65 to 74 get cataracts. A cataract is a clouding of the eye&#39;s lens that impairs a person&#39;s vision and, if left untreated, causes blindness. As a result, each year approximately 1.4 million people in the United States alone undergo cataract surgery, whereby the clouded natural crystalline lens is removed and replaced with an intraocular lens (IOL) implant. 
     Surgeons implant IOLs not only as a replacement for the natural crystalline lens but also to alter the optical properties of (provide vision correction to) an eye with an existing IOL or in which the natural lens remains. IOLs often include an optically clear disk-like optic of about 6 mm in diameter, and preferably at least one flexible fixation member or haptic which extends radially outward from the optic and becomes affixed in the eye to secure the lens in position. 
     The optics may be constructed of rigid biocompatible materials such as polymethyl methacrylate (PMMA) or deformable materials such as silicone polymeric materials, acrylic polymeric materials, hydrogel polymeric materials, and the like. The deformable materials allow the IOL to be rolled or folded for insertion through an injector or insertion cartridge and an incision into the eye. Once within the chamber of the eye, the IOL is expulsed from the injector and returns to its original shape. 
     Injectors or inserters for delivering IOLs into the eye typically employ a handpiece and a removable cartridge that receives the IOL and has a hollow insertion tube or cannula through which the folded IOL is passed using a pushrod. Some inserters do without the cartridge. The inserter may be wholly or partly reusable, in which case the inserter or handpiece is usually made of some type of metal alloy that can be sterilized. Alternatively, disposable inserters made of less expensive materials, such as plastics, remain in a sterile package until ready for use. In some cases, the IOL is stored separately and transferred to a load chamber in the inserter or cartridge just prior to delivery. One particularly useful arrangement wherein the cartridge folds over an IOL is disclosed in U.S. Pat. No. 4,681,102 to Bartell. A cartridge opens to receive an IOL in a load chamber, and then folds closed and fits into an injector. A syringe-like plunger in the injector pushes the IOL from the load chamber through a tapered tube into the eye. The IOL unfolds as it emerges from the tip of the tapered tube. Another such insertion system is disclosed in Makker et al., U.S. Pat. No. 5,942,277. An example of storing an IOL in an inserter component is seen in U.S. Pat. No. 7,156,854, filed May 28, 2003. In the &#39;854 patent, a nozzle portion  12  along with a removable stop  26  retains the IOL therein during storage and has internal ramps that assist in folding the IOL optic during an implant procedure. Also, U.S. Patent Publication No. 2008/0058830, filed Jul. 17, 2007, discloses a number of configurations for pre-loading IOLs for transfer to an insertion apparatus, and is expressly incorporated herein. Another preloaded insertion system is illustrated in U.S. Patent Publication No. 2009/0318933, filed Jun. 23, 2008, which is hereby incorporated by reference in its entirety. 
     Despite the advances in the area of insertion devices, there remains a need for devices and systems that increase the ease of use of inserters, including facilitating the insertion of IOLs, while reducing the risk of damage to both the insertion device and the IOL. 
     SUMMARY OF THE INVENTION 
     The present inventions disclose a protective cap having a window and a port at a distal end of the cap, wherein the cap is configured and dimensioned to couple with a distal end of an insertion system. The window of the protective cap may have a fill indicator. In an embodiment, the window is located on a top of the cap and wherein the window runs along at least a portion of a longitudinal axis of the cap. In an additional embodiment, the cap may have an internal bevel inside the cap at the distal end, wherein the internal bevel is configured and dimensioned to couple with a bevel at the distal end of an insertion system. Additionally, the cap may have at least two finger grips along at least a portion of a longitudinal axis of the cap and wherein the finger grips are located on opposite sides of the cap. 
     According to embodiment, the port of the protective cap comprises a funnel shape and is configured and dimensioned to couple with a lumen at a distal end of an insertion system to enable insertion of a fluid into the lumen of the insertion system. The distal end of the cap may also have a material relief to prevent distortion of a tip at a distal end of the cap during manufacturing of the cap. In another embodiment, one or more internal walls of the cap comprise one or more internal guides that run along at least a portion of a longitudinal axis of the cap, wherein the one or more internal guides are configured and dimensioned to couple with features on an outer portion of an insertion device. In an embodiment, the cap may also have two substantially parallel internal guides. 
     According to an embodiment, an insertion system may include a handpiece having a longitudinal axis, a distal end, and a proximal end; a pushrod assembly having a distal end and a proximal end, wherein the push rod assembly comprises a pushrod and a plunger, couples with the handpiece along the longitudinal axis; and wherein the pushrod is coupled with the plunger and the pushrod is located on the distal end of the push rod assembly and the plunger is located on the proximal end of the pushrod assembly. The insertion system may also include a cartridge having a delivery tube at a distal; wherein the cartridge is configured and dimensioned to couple with the distal end of the handpiece; and a cap having a window and a port; wherein the cap is configured and dimensioned to couple with the distal end of the cartridge. In an embodiment, the cartridge further includes one or more wings and the cap further includes one or more clips, wherein the one or more clips are configured and dimensioned to couple with the one or more wings. In an embodiment, the cap further includes an internal bevel inside the cap at a distal end, wherein the internal bevel is configured and dimensioned to couple with a bevel at the distal end of the delivery tube. In another embodiment, the cap may include at least two finger grips along at least a portion of a longitudinal axis of the cap and wherein the finger grips are located on opposite sides of the cap. In an embodiment the window may have a fill indicator and the window may be located on a top of the cap, wherein the window runs along at least a portion of a longitudinal axis of the cap. 
     According to an embodiment the port may include a funnel shape that is configured and dimensioned to couple with a lumen at a distal end of an insertion system to enable insertion of a fluid into the lumen of the insertion system. In an embodiment, the distal end of the cap may have a material relief to prevent distortion of a tip at a distal end of the cap during manufacturing of the cap. In another embodiment, one or more internal walls of the cap comprise one or more internal guides that run along at least a portion of a longitudinal axis of the cap, wherein the one or more internal guides are configured and dimensioned to couple with features on an outer portion of an insertion device. The In an embodiment, the cap may also have two substantially parallel internal guides. 
     According to an embodiment, an insertion system may include a handpiece having a longitudinal axis, a distal end, and a proximal end; a pushrod assembly having a distal end and a proximal end, wherein the push rod assembly comprises a pushrod and a plunger, couples with the handpiece along the longitudinal axis; and wherein the pushrod is coupled with the plunger and the pushrod is located on the distal end of the push rod assembly and the plunger is located on the proximal end of the pushrod assembly. The plunger of the insertion system may also have a marker configured and dimensioned to indicate axially translation of the pushrod assembly within the handpiece; and a cartridge comprising a delivery tube at a distal end, wherein the cartridge is configured and dimensioned to couple with the distal end of the handpiece. In an embodiment, the marker is configured and dimensioned to indicate a location of a detent when the pushrod assembly is advanced toward the distal end of the handpiece. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention is best understood with reference to the following detailed description of the invention and the drawings in which: 
         FIG. 1  is an assembled perspective view of an insertion system according to an embodiment of the invention; 
         FIG. 1A  is an assembled perspective view of an insertion system according to an embodiment of the invention; 
         FIG. 2  is a top view of an insertion system according to an embodiment of the invention; 
         FIG. 2A  is a top view of an insertion system according to an embodiment of the invention; 
         FIG. 3  is a side view of an insertion system according to an embodiment of the invention; 
         FIG. 3A  is a side view of an insertion system according to an embodiment of the invention; 
         FIG. 4  is a bottom view of an insertion system according to an embodiment of the invention; 
         FIG. 4A  is a bottom view of an insertion system according to an embodiment of the invention; 
         FIG. 5  is an exploded view of the insertion system according to  FIGS. 1 and 1A ; 
         FIG. 6  is a perspective view of a puller cap according to an embodiment of the invention; 
         FIG. 7  is a perspective view of a puller cap according to an embodiment of the invention; 
         FIG. 8  is cross-sectional view of a puller cap and insertion system according to an embodiment of the invention; 
         FIG. 9  is cross-sectional view of a puller cap and insertion system according to an embodiment of the invention; 
         FIG. 10  is an assembled perspective view of an insertion system with a puller cap according to an embodiment of the invention; 
         FIG. 11  is an assembled perspective view of an insertion system with a puller cap according to an embodiment of the invention; 
         FIG. 12  is an assembled perspective view of an insertion system with a puller cap according to an embodiment of the invention; 
         FIG. 13  is an assembled perspective view of an insertion system with a puller cap according to an embodiment of the invention; 
         FIGS. 14A-14E  are multiple views of a pin according to an embodiment of the invention; 
         FIG. 15  is a cross-sectional perspective view of a puller cap and insertion system according to an embodiment of the invention; 
         FIG. 15A  is a cross-sectional view of a pin, puller cap, and insertion system according to an embodiment of the invention; 
         FIG. 16  is a cross-sectional perspective view of a puller cap and insertion system according to an embodiment of the invention; 
         FIG. 17  is a cross-sectional perspective view of a puller cap and insertion system according to an embodiment of the invention; 
         FIGS. 18A-18C  are cross-sectional views of an alternate embodiment of the puller cap; 
         FIG. 18D  is a perspective view of the alternative embodiment of the puller cap shown in  FIGS. 18A-18C ; 
         FIG. 19A  is a side view of a pushrod according to an embodiment; 
         FIG. 19B  is a side view of a pushrod according to an embodiment; 
         FIG. 19C  is a side view of a pushrod according to an embodiment; 
         FIG. 19D  is a perspective view of pushrod according to an embodiment of the invention; 
         FIG. 19E  is a side view of a pushrod according to an embodiment; 
         FIG. 19F  is an alternate side view of a push rod according to an embodiment; 
         FIGS. 19G and 19H  are alternative views of a portion of a push rod according to an embodiment; 
         FIG. 20  is a cross-sectional perspective view of the pushrod in  FIG. 19D ; 
         FIG. 21  is a cross-sectional view of a puller cap and insertion system according to an embodiment of the invention; 
         FIG. 22A  is a perspective view of the protective cap according to an embodiment; 
         FIG. 22B  is a top view of the protective cap according to an embodiment; 
         FIG. 22C  is a side view of the protective cap according to an embodiment; 
         FIG. 22D  is a front view of the protective cap according to an embodiment; 
         FIG. 22E  is a side view of the protective cap according to an embodiment; 
         FIG. 22F  is a rear view of the protective cap according to an embodiment; 
         FIG. 22G  is bottom view of the protective cap according to an embodiment; 
         FIG. 23A  is a cross-sectional view of the protective cap shown in  FIG. 22F ; 
         FIG. 23B  is a cross-sectional view of the protective cap shown in  FIG. 22D ; 
         FIG. 24  is a cross-sectional view of the protective cap shown in  FIG. 22B ; 
         FIG. 25  is an assembled perspective view of an insertion system with a protective cap according to an embodiment of the invention; 
         FIG. 26  is an assembled perspective view of an insertion system with a protective cap according to an embodiment of the invention 
         FIGS. 27A-27F  are additional embodiments of a protective cap; 
         FIGS. 28A-28F  are additional embodiments of a protective cap; 
         FIGS. 29A-29F  are additional embodiments of a puller cap; 
         FIGS. 30A-30F  are additional embodiments of a puller cap; 
         FIG. 31A  is a side view of an insertion system according to an embodiment; 
         FIG. 31B  is a side view with a cutout portion of an insertion system according to an embodiment; 
         FIG. 31C  is a side view of an insertion system according to an embodiment; 
         FIG. 32  is a cross-sectional view of a rails and channels embodiment; 
         FIG. 33  is a perspective view of a nut lock according to an embodiment; 
         FIG. 33A  is a cross-sectional view of a nut lock according to an embodiment; 
         FIG. 33B  is a cross-sectional view of a nut lock according to an embodiment; and 
         FIG. 34  is a perspective view of a detent safety embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Reference will now be made in detail to embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the embodiments, it will be understood that they are not intended to limit the invention to those embodiments. On the contrary, the invention is intended to cover alternatives, modifications, and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. 
       FIGS. 1-4  illustrate varying views of an exemplary IOL insertion system  20  of the present invention comprising a twist/syringe-style device having, generally, a handpiece  22 , a plunger  24 , and a delivery tube  26  on a distal end/portion thereof. As illustrated in  FIGS. 1-3 , IOL insertion system  20  may also include puller pin  100 , which will be described in greater detail below. As illustrated in  FIG. 4 , system  20  also may comprise port  21  to enable application or insertion of a fluid, such as water, balance salt solution, and/or viscoelastic.  FIGS. 1A-4A  illustrates an alternative IOL insertion system  20  of the present invention. The IOL insertion system  20  illustrated in  FIGS. 1A-4A  does not include puller pin  100  or port  21 . It is also envisioned that IOL insertion system  20  may include only one of the puller pin  100  or the port  21 . The system  20  is also shown in an exploded view in  FIG. 5 . 
     IOL  31  is shown in  FIG. 5  and may be positioned between two halves of a holding station  30 . IOL  31  may comprise a central circular optic  32  having a leading haptic  34  and a trailing haptic  36  generally spirally extending therefrom. One exemplary IOL as illustrated is a one piece acrylic Tecnis® brand of aspheric IOL available from Abbott Medical Optics Inc. of Santa Ana, Calif. It is also envisioned that any IOL may be used with the insertion system disclosed herein. 
     With reference to  FIGS. 1-5  and  FIGS. 1A-4A , the system  20  defines a longitudinal axis from an end cap  40  of a pushrod assembly  60  at a proximal end to the delivery tube  26  at a distal end. The pushrod assembly  60  includes a plunger  24 , an end cap  40 , a nut lock  102 , and a pushrod  61 . Pushrod  61  may have a distal tip  62 . In an embodiment, a portion of distal tip  62  may be flexible as described in greater detail below. In the illustrated embodiment, the distal tip  62  is forked to enable reliable capture of a proximal edge of the IOL optic  32  and/or trailing haptic  36 . The plunger  24  and/or pushrod  61  translates axially through an elongate passage defined within the inserter handpiece  22  and is configured to urge the IOL from a holding station  30  through the distal delivery tube  26 . In a general sense, the plunger  24  represents any actuator capable of displacing the IOL from the holding station  30  in a distal direction through a delivery tube or other such device. The plunger  24  therefore may be generally termed an actuator so as to encompass other prime movers that can perform the same function, such as a rotary actuators, threaded actuators, levers, etc. 
       FIG. 5  is an exploded view of the components of the system  20  in the orientation in which they will be assembled. However, a preferred mold configuration results in a total of six (or possibly fewer) components for the entire system, not counting the IOL. It is also envisioned that the mold configuration results in a total of seven or more components for the entire system, not counting the IOL depending upon many factors, including but not limited to manufacturing requirements. The six components shown in  FIG. 5  include the plunger  24 , the pushrod  61 , the cartridge  28 , the nut lock  102 , the upper body  56 , and the lower body  57 . Lower body  57  may include the holding station  30  and base portion  52 . Cartridge  28  comprises delivery tube  26  and wings  27 . It is possible that the handpiece upper body  56  could be formed along with the remainder of the handpiece, though the mold would be fairly complicated and expensive. Likewise, the cartridge  28  could be incorporated into the handpiece  22 , but again for reasons of manufacturing economy they are separate. 
     The one half of the holding station  30  comprises a base  50  that, in a preferred embodiment, forms a distal extension of a base portion  52  of the handpiece  22 . The upper half of the holding station  30  comprises a cover  54  that abuts the upper body  56  of the inserter handpiece  22 . In the illustrated embodiment, as seen in  FIG. 5 , the cover  54  and upper body  56  fit directly over the base  50  and base portion  52  to form the elongated handpiece  22 . The overall shape of handpiece  22  may be of any shape to accommodate proper gripping of the device. According to an embodiment, the holding station cover  54  may be connected by a pair of living hinges  80   a,    80   b  to the base  50 . The base  50  includes a pair of bifurcated fingers  82   a,    82   b  that meet a similar pair of bifurcated fingers  84   a,    84   b  extending from the cover  54  at the living hinges  80   a,    80   b . The opposed pairs of aligned fingers  82 ,  84  are shaped so as to form slots therebetween when folded about the living hinges  80  and a central cavity  86  (shown in  FIG. 5 ) for receiving a delivery tube  26 , the combination of which is best seen in the assembled view of  FIGS. 1 and 1A . In this regard, the delivery tube  26  desirably comprises a rear-loading cartridge as shown, and as described in co-pending U.S. Patent Publication No. 2009-0270876, filed on Apr. 28, 2008, which is hereby incorporated by reference in its entirety. In an embodiment, hinges  80   a  and  80   b  may be a snap feature instead of living hinges. In such an embodiment, holding station cover  54  may be molded as a separate part from base portion  52  and base  50 . 
     The handpiece may further include a pair of proximal finger tabs  60   a,    60   b,  one on the base portion  52  and one on the upper body  56 . When an operator desires to depress the plunger  24 , he or she places the thumb of one hand on the end cap  40 , and index and middle fingers on respective finger tabs  60   a,    60   b.  Squeezing the hand closed depresses the end cap  40  and moves the rest of pushrod assembly  60  along a lumen of the IOL insertion system  20  toward the distal end of the delivery tube  26 . 
     Puller Cap 
       FIGS. 10-13  illustrate different views of system  20  with puller cap  70 . Puller cap  70  fits over the holding station  30  and cartridge  28  in order to protect these components, and in particular the delivery tube  26 , while also facilitating the insertion of fluid as further described below. 
       FIGS. 6 and 7  show two views of puller cap  70  of the present invention. In  FIG. 6 , puller cap  70  has a top  72 , a bottom  73 , a proximal end  75 , and a distal end  85 . Puller cap  70  includes lock  95 A,  95 B, grips  93 , snap  90 , and port  87 . Puller cap  70  may be made of any material known in the art, but preferably polypropylene, polycarbonate, polyethylene, or polyethylene terephthalate; more preferably polypropylene and polycarbonate; most preferably polypropylene. Puller cap  70  may also be of any color, preferably translucent or clear to enable a user to visualize the features inside puller cap  70  and anything housed within puller cap  70 . Puller cap  70  may be the shape as illustrated in the embodiment in  FIG. 6 , but the invention also envisions that puller cap  70  may be of any shape or size to accommodate the needs of the insertion system the puller cap is used with or the needs of the user the puller cap is designed for. For example, the puller cap may be of an arrow shape as illustrated in the embodiment in  FIG. 6 , may be more of a round shape, triangular shape, square shape, or shaped to meet the needs for shipping and/or handling. The puller cap may also include one or more hook features (not shown) to aid in the removal of the puller cap from an inserter. The hook feature may be located on any location on the puller cap, including but not limited to the top, bottom, on or near the snap, or near the distal or proximal ends. The hook feature may be of any shape or size to accommodate for the shape or size of the puller cap and may be of any shape or size to accommodate the fingers of a user. 
     The lock  95 A and  95 B may be of any design or configuration known in the art. According to an embodiment of the present invention, a portion  96  of locks  95 A,  95 B are configured and dimensioned to cam outwardly when external pressure is placed on the snaps in a perpendicular plane with respect to the longitudinal plane of system  20  from proximal end  75  to distal end  85 . (See  FIG. 7 ). Locks  95 A,  95 B may comprise a texture design or feature to ease gripping and/or actuation of the snaps and removal of puller cap  70  from an insertion system, such as insertion system  20  as illustrated in  FIGS. 1-5 and 1A-4A . In an embodiment, puller cap  70  may have one or more grips having a texture design or feature and the lock  95 A and  95 B are separated from the one or more grips, such that squeezing of the grips does not deactivate locks  95 A and  95 B. 
     As shown in  FIG. 6 , the snap  90  is designed and configured to couple with pin  100  (see  FIGS. 14 and 15 ). Snap  90  may be of any shape or size as long as it is configured and dimensioned to mate with pin  100 . According to the embodiment in  FIG. 6 , snap  90  comprises a canopy  92  and a keyway  94 . In another embodiment, snap  90  does not have a canopy and only has keyway  94 . 
     Puller cap  70  may include one or more ports  87  to aid in the insertion of a fluid, including but not limited to balanced salt solution, water, and/or viscoelastic. The one or more ports  87  mate with ports located on the insertion system  20  to assist with filling a portion of the system with fluid to provide lubrication to the internal features of the insertion system to aid in delivery of the IOL. With respect to port  87  as illustrated in  FIG. 6 , port  87  acts a funnel mechanism into the distal end of delivery tube  26 .  FIG. 7  illustrates a bottom view of puller cap  70  comprising port  88  and a window  89 . The puller cap may also comprise one or more windows to provide the users with a visual indicator of the amount of fluid inserted into a portion of the insertion system, as well as provide viewing of the distal end of a cannula tip, which is typically used to inject a fluid. In an embodiment, the one or more windows may be located on the top, bottom or sides of the puller cap, preferably on the top or the bottom. The one or more windows may also comprise a measuring devise such as a ruler to allow a user to measure or see the amount of fluid inserted into the inserter. The window  89  may also have a fill indicator  99  such that a user fills a portion of the insertion system until the fluid reaches fill indicator  99  indicating a proper and/or maximum fill has been reached. The one or more windows may also comprise a material such that when a fluid is inserted into the insertion system and viewed through the window light that is emitted through the window to the fluid is polarized providing a visual indicator of the fluid within the inserter. 
     As is well known in the art, the small nature of the ports of insertion systems known in the art can make it very difficult for doctors, nurses, and/or staff to locate openings for inserting fluids. The puller cap of the present invention solves this problem by providing a larger port with a funnel feature that leads into the smaller ports of the insertion system. This enables a user to more easily direct a cannula tip  101  into a delivery tube  26  or ports  87 ,  88  as illustrated in  FIGS. 8 and 9 . 
     Pin and Haptic Sweep Slot 
       FIGS. 14A-E  shows pin  100  which includes top  105 , stem  107 , key  109 , and lock  113 . Top  105  comprises key  109  that may be of any shape or configuration so as to mate with snap  90 . Lock  113  may be of any shape or size and is configured to mate with grove  115  of haptic sweep slot  117  of cover  54  (see  FIG. 16 ). Lock  113  may also be located anywhere along stem  107  and the present invention also envisions more than one lock feature. Haptic sweep slot  117  may also be of any shape or size as long as it is configured to mate with pin  100 . According to an embodiment, haptic sweep slot  117  runs along the same longitudinal axis of system  20 . In an embodiment, the length of the haptic sweep slot is longer in length than the width the slot. In an embodiment, the length of the haptic sweep slot is between about 0.150 inches (in.) (3.81 millimeters (mm)) to about 0.170 in. (4.318 mm), preferably about 0.153 in. (3.8862 mm), more preferably about 0.165 in. (4.191 mm). In an embodiment, the width of the haptic sweep slot is about 0.028 in. (0.7112 mm) to about 0.040 in. (1.016 mm), preferably about 0.030 in. (0.762 mm), more preferably about 0.035 in. (0.889 mm). Pin  100  is configured and dimensioned to be inserted into haptic sweep slot  117  such that lock  113  and groove  115  are coupled together securing the two parts together, but still enabling the pin  100  to move within haptic sweep slot  117 . Groove  115  may also be of any shape or size as long as it is configured to mate with lock  113 . In an embodiment, there may be more than one groove in the haptic sweep slot. Groove  115  enables pin  100  to maintain a substantially perpendicular orientation with respect to the longitudinal axis of system  20 . According to an embodiment, the substantially perpendicular orientation assists with sweeping or folding of trailing haptic  36  as further described below. 
     Pin  100  may comprise leg feature  125  (see  FIGS. 14A-14E ); such that pushrod  61  is capable of passing step  107  once pin  100  has been advanced forward to sweep trailing haptic  36 . The leg feature  125  results in stem  107  having a cut out or offset portion as shown in  FIGS. 14A , B, C and E. To ensure that this leg feature  125  is in the correct orientation during manufacture, lock  109  may comprise a one-way directional snap feature or poke-oke as illustrated in an embodiment in  FIGS. 14C  and D. 
     In an embodiment, pin  100  is configured and dimensioned to penetrate or extend through cover  54  and base  50  or another portion of system  20  or similar device to sweep or fold a trailing or leading haptic or similar feature of an IOL. 
     Puller Cap and Pin Function 
     As shown in  FIGS. 10 and 15 , as puller cap  70  is placed on system  20  to cover cartridge  28  and delivery tube  26 , snap  90  mates or couples with pin  100  via key  109  and keyway  94 . See  FIG. 15A  for a cross-sectional view showing pin  100  coupled with snap  92  in keyway  94  and lock  113  coupled with groove  115 . In addition to the functions described above, puller cap  70  with pin  100  function to fold or sweep the trailing haptic  36  in the distal direction prior to folding or moving the IOL in the distal direction to insert the IOL into the eye. Folding or sweeping trailing haptic  36  in the distal direction controls the location of the haptic and prevents damage to the haptic during delivery of the IOL. Pin  100  may also sweep the trailing haptic  36  over a portion of optic  32  such that during movement of the IOL down the lumen of tube  26  at least a portion of the trailing haptic  36  is captured in the fold or folds of the optic  32 . Prior to the present invention a user would have to manually use the distal end of a cannula to fold or sweep the trailing haptic, which was difficult to do due to the small nature of the slot. Moreover, it was difficult to visualize whether the haptic was in fact in place once the cannula moved the haptic. The present invention overcomes these problems. Once puller cap  70  is coupled with pin  100  a user may use the easy to access one or more ports  87 ,  88  to insert/inject fluid into system  20 . Next, to sweep trailing haptic  36  a user may grasp and squeeze locks  95 A,  95 B to release the internal lock features, e.g. portion  96  of lock  95 A, B from wings  27 . As puller cap  70  is advanced distally from system  20  along the longitudinal axis of system  20  pin  100  slides along haptic sweep slot  117  and lock  113  slides in groove  115  as shown in  FIG. 16 . When pin  100  reaches the end of haptic sweep slot  117 , pin  100  will release from snap  90 , releasing puller cap  70  from system  20  as shown in  FIG. 17 . At this point, trailing haptic  36  has been swept or folded into the proper position without the use of another tool and the IOL is now ready for insertion into the eye. 
     In an alternate embodiment, pin  100  may release from cover  54  with puller cap  70 . It is also envisioned that pin  100  may be connected to one or more arms and one or more hinges to aid in its connection to puller cap  70  and its release from system  20 .  FIG. 18A  shows such an alternate embodiment of the present invention. In  FIGS. 18A-D , pin  100  is connected to arm  123  which is connected to arm  124  via hinge  122 . Arms  123  and  124  may further be coupled with puller cap  70  with hinge  126  and  127  (as shown in  FIGS. 18C and 18D ) or by any other mechanism known in the art. As puller cap  70  is moved distally along the longitudinal axis of system  20  to sweep trailing haptic  36  pin  100  is advanced along haptic sweep slot  117 . When pin  100  reaches the end of haptic sweep slot  117 , further advancement of puller cap  70  causes arm  124  to lift up thereby lifting arm  123  and lifting pin  100  from haptic sweep slot  117  and releasing puller cap  70  from system  20 . In an embodiment, haptic sweep slot  117  may comprise a ramp at one or both ends of the slot. In particular, a haptic sweep slot  117  may comprise a ramp at the distal end  121  of the slot to aid in the release of pin  100  and/or puller cap  70  after trailing haptic  36  has been swept or folded. According to another embodiment, only a single arm or a single hinge may be used with pin  100 . In another embodiment, one or more arms or one or more hinges may used with pin  100 . 
     In an embodiment, pin  100  maintains trailing haptic  36  in the proper orientation for delivery and even if a user decides to place puller cap  70  back onto system  20 , the internal features of system  20  still maintain trailing haptic  36  in the proper orientation. This allows a user to determine when she would like to use and/or the order in which she will use the haptic sweep feature, the port features, and the tip protection feature, which will be described further below. 
     Pushrod 
       FIG. 19A  illustrates a pushrod capable of being used with the system  20 . Pushrod  61  comprises a top jaw  63  and a bottom jaw  64  that form mouth  67 . Top jaw  63  may also comprise a lip  65  that protrudes from an upper portion  66  of top jaw  63 . In an embodiment, lip  65  is configured and dimensioned to help catch trailing haptic  36  and keep trailing haptic  36  in a swept/folded configuration.  FIG. 19D  illustrates an exemplary pushrod of the present invention modifying the features of  FIG. 19A . In  FIG. 19D  a portion of the distal end of pushrod  61  is removed resulting in cutout portion or notch  68  to allow room for the IOL as it is folded and/or compressed during insertion of the IOL into an eye. The cutout portion  68  of pushrod  61  provides for less force on the walls of delivery tube  26  and less force on the IOL as it delivered preventing damage to the IOL and delivery tube  26 . In an embodiment, cutout portion  68  comprises approximately half the diameter of the top jaw  63  for a portion of the distal end including the lip  65 , while bottom jaw  63  remains intact. Cutout portion  68  may extend proximally beyond top jaw  63  into the body of pushrod  61 . In an embodiment, a notch or cutout portion may also extend or be placed into bottom jaw  64 . It is also envisioned that an additional notch or cutout similar to notch  68  can be made on the opposite side of top jaw  63 . Bottom jaw  64  may also have one or more notches. In an embodiment, a cross-section view of cutout portion  68  shows an L-shaped seat (see  FIG. 20 ). 
     In an embodiment, lip  65  is configured to ride along at least a portion of an internal channel or groove located within handpiece  22 . Lip  65  provides more stability for the pushrod  61  as it is advanced within a lumen of the handpiece  22  towards the distal end of the handpiece. By having the lip  65  engage at least a portion of the internal channel, the distal end of the pushrod is less likely to move from its desired location within the lumen as the pushrod is advanced towards the distal end of the handpiece. 
     According to an embodiment, the distal end of pushrod  61  may have a top jaw  63  and a bottom jaw  64  that form mouth  67  as illustrated in  FIGS. 19E-19H . As shown in  FIG. 19E , top jaw  63  is shorter in length than bottom jaw  64  and includes cutout portion  68 . For such an embodiment sweeping of the trailing haptic by pin  100  or another means is unnecessary because the design of the distal end of pushrod  61  causes the trailing haptic of an IOL to be swept or folded over the optic as the pushrod assembly  60  travels down the lumen of the insertion system towards the distal end of the delivery tube. In an embodiment, the top jaw is designed to engage the trailing haptic of an IOL before the bottom jaw engages the lens body or edge of the optic. In an embodiment, the height of the top jaw is such that it configured to couple with at least a portion of an internal channel of the handpiece, preferably the top jaw is configured to couple with at least a portion of an internal channel located in the staging area, more preferably the top jaw is configured to couple with an internal channel extending through the staging area. In another embodiment, the blunt tip may a height that is larger than the height of a haptic, e.g. a trailing haptic. 
     In an embodiment, the distal end of pushrod  61  may comprise another cutout portion  69  on the opposite side of the first cutout portion. The second cutout portion  69  may also provides for less force on the walls of delivery tube  26  and less force on the IOL as it delivered preventing damage to the IOL and delivery tube  26 . For example, as the IOL is advanced down the delivery tube, the IOL is compressed. The second cutout portion  69  provides space for an edge of the IOL to wrap around the top jaw  63  and tuck into the second cutout portion  69 . The second cutout portion may be shorter or longer in length than the first cutout portion  68 , preferably shorter than the first cutout portion  68 . The width of the second cutout portion may be larger or smaller than the width of the first cutout portion, preferably small that the width of the first cutout portion. The second cutout portion  69  may create a substantially L-shaped seat. In an embodiment, a notch or cutout portion may also extend or be placed into bottom jaw  64 . It is also envisioned that an additional notch or cutout similar to cutout portion  68  and  69  can be made on one or both sides of bottom jaw  64 . 
     Similar to the lip  65  discussed above, in an embodiment, the top jaw  63  illustrated in  FIGS. 19E-19H  is configured to ride along at least a portion of an internal channel or groove located within handpiece  22 . Coupling of the top jaw  63  with at least a portion of an internal channel provides more stability for the pushrod  61  as it is advanced within a lumen of the handpiece  22  towards the distal end of the handpiece. By having the at least a portion of top jaw  63  engage at least a portion of the internal channel, the distal end of the pushrod is less likely to move from its desired location within the lumen as the pushrod is advanced towards the distal end of the handpiece. The forces generated by moving the IOL down the lumen of the staging area and/or lumen of the cartridge can have a tendency to push or offset the distal end of the pushrod. Coupling the top jaw  63  with at least a portion of the internal channel or groove helps to counter this movement and maintain the distal end of the pushrod in proper alignment, e.g. maintaining the distal end of the pushrod substantially on center of the lumen of the handpiece. In an embodiment, the internal channel or groove runs the length of the staging area. 
     In an embodiment, the top jaw  63  may have a blunt tip  71  and a rounded top portion  74 . The blunt tip  71  sweeps or folds the trailing haptic of an IOL over the optic as the pushrod assembly  60  travels down the lumen of the insertion system towards the distal end of the delivery tube. The top jaw  63  and the bottom jaw  64  may have a rounded leading edge  76 . Rounding the leading edge prevents damage to an IOL as it is moved down the lumen of an insertion system. 
     In an embodiment, pushrod  61  has a tapered portion around the circumference of the pushrod starting at or near the back of mouth  67  and extends a long a length of the pushrod. In an embodiment, the tapered portion extends approximately  2 / 3  the total length of pushrod  61 . As shown in  FIG. 19F , beginning at or proximally near the back of the mouth  67 , the diameter of the tapered portion gradually gets smaller until approximately the midline of the tapered portion and then begins to gradually get larger until it reaches the largest diameter of the pushrod  68 . The smallest diameter of the tapered portion may occur at the halfway point of the entire length of the tapered portion. In an embodiment, the smallest diameter occurs beyond the halfway point of the entire length of the tapered portion in the proximal direction. The length of the tapered portion may be between about 0.280 in. (7.122 mm) and about 0.325 in. (8.255 mm). The diameter of the pushrod at its largest diameter may be between about 0.080 in. (2.032 mm) and about 0.060 in. (1.524 mm), preferably 0.070 in. (1.778 mm); and the smallest diameter of the tapered portion may be between about 0.045 in. (1.143 mm) and about 0.060 in. (1.524 mm). The tapered portion provides for space and/or allows for a trailing haptic to wrap around the pushrod should the haptic not fold over the optic, which prevents the IOL from being damaged or broken off from the rest of the IOL. 
     In an embodiment, cutout portion or notch  68  may extend into a portion of the tapered portion. Cutout portion  68  is designed as a safety feature to (1) provide space for the folding IOL as it is advanced down a tapered lumen; (1) allow for a trailing haptic to wrap around the pushrod and/or guide the trailing haptic around the tapered portion should the haptic not fold over the optic; (3) allow for extension of a trailing haptic that does not get folded; and/or (4) allow space for shoulder or bend that is created near the optic-haptic junction when the trailing haptic is folded over the optic, which prevents the IOL from being damaged or broken off from the rest of the IOL. In an embodiment, the cutout portion  68  may have a length between about 0.150 in. (3.81 mm) and about 0.300 in. (7.62 mm), a height between about 0.030 in. (0.762 mm) and about 0.050 in. (1.27 mm), and a width between about 0.040 in. (1.016 mm) and about 0.065 in. (1.651 mm). The length of the cutout portion  68  may also be longer or shorter than the full extension of an IOL haptic. Cutout portion  68  may begin at or near the tip of pushrod  61  or at or near the back of the mouth  67  and continue a length of the pushrod  61 . The cutout portion  68  may continue a length of the pushrod  61  with its width gradually tapering out or becoming smaller until it meets the side of the pushrod (see  FIG. 19G ). 
     The features of pushrod  61  as shown in  FIGS. 19A-19D  may have various dimensions. The length of the cutout portions  68  may be between about 0.145 in. (3.683 mm) to about 0.165 in. (4.191 mm), preferably between about 0.149 in. (3.7846 mm) to about 0.160 in. (4.064 mm), more preferably about 0.149 in. (3.7846 mm) or about 0.160 in. (4.068 mm). The width of upper portion  66  of top jaw  63  may range from about 0.015 in. (0.381 mm) to about 0.030 in. (0.762 mm), preferably about 0.023 in. (0.5842 mm). The diameter or width A of cutout portion  68  as shown in  FIG. 20  may be between about 0.015 in. (0.381 mm) to about 0.025 in. (0.635 mm), preferably about 0.019 in. (0.4826 mm). According to an embodiment, the diameter A of cutout portion  68  may be inversely proportional to the width of the upper portion  66  of top jaw  63 . The height of lip  65  that protrudes up may be between about 0.003 in. (0.0762 mm) to about 0.012 in. (0.3048 mm), preferably about 0.006 in. (0.1524 mm). In an embodiment, there may be a radius on the back side of lip  65  where lip  65  and upper portion  66  meet. The radius may be sharp to 0.010R. In an embodiment, the radius of mouth  67  that engages a lens may range between 0.012R-0.020R, preferably about 0.014R. The length of top jaw  63  and the bottom jaw  64  from the back of mouth  67  may be between about 0.045 in. (1.143 mm) and about 0.070 in. (1.778 mm). In an embodiment the length of top jaw  63  is preferably about 0.054 in. (1.3716 mm). The top jaw length may have a relationship (ratio) to the bottom jaw which is about 1.3 to 1 (Top to Bottom). In an embodiment, the relationship may be 1 to 1 or 1 to 1.3 (Top to Bottom). 
     The features of pushrod  61  as shown in  FIGS. 19E-19H  may have various dimensions. The length of the cutout portions  68  may be between about 0.150 in. (3.81 mm) to about 0.300 in. (7.62 mm), preferably between about 0.190 in. (4.826 mm) to about 0.250 in. (6.35 mm), more preferably about 0.190 in. (4.826 mm). The diameter or width of cutout portion  68  as shown may be between about 0.020 in. (0.508 mm) to about 0.030 in. (0.762 mm), preferably about 0.025 in. (0.635 mm). In an embodiment, the radius of mouth  67  that engages a lens may range between 0.010R-0.018R, preferably about 0.013R. The width of the top jaw may be between about 0.020 in. (0.508 mm) and about 0.030 in. (0.762 mm) and the width of the bottom jaw may be between about 0.060 in. (1.524 mm) and about 0.040 in. (1.016 mm). The top jaw may be offset from a centerline along the longitudinal axis of the pushrod. The top jaw length may have a relationship (ratio) to the bottom jaw which is about 1 to 2 (Top to Bottom). In an embodiment, the relationship may be 1 to 1 or 1 to 1.3 (Top to Bottom). The width of the top jaw may have a relationship to the width of the bottom jaw which is about 1 to 2 (Top to Bottom). In an embodiment, where the top portion of the top jaw meets the side wall of the notch, the radius of curvature or blending may be about 0.010R. Also, in another embodiment the length of the notch may be about 60% of the total length of the pushrod. 
     Pushrod Flex Tip 
     As discussed above,  FIG. 5  shows an exploded view of pushrod assembly  60  which comprises pushrod  61 , plunger  24 , and nut lock  102 . 
     According to an embodiment of the present invention, pushrod  61  comprises distal tip  62  at the distal end of pushrod  61  that has a top jaw  63  and a bottom jaw  64 , which is shown in FIG.  19 A. Top jaw  63  of distal tip  62  is capable of flexing toward bottom jaw  64  shown by arrow “B” to allow the distal tip  62  (or distal end) of pushrod  61  to pass through the tapered lumen of delivery tube  26 . Top jaw  63  may comprise a lip  65  that protrudes from an upper portion  66  of top jaw  63  and is capable of making contact with the lumen of delivery tube  26 .  FIG. 19B  illustrates lip  65  coming in contact with the lumen  70  of delivery tube  26  and top jaw  63  flexing toward bottom jaw  64 . Lip  65  may make continuous or substantially continuous contact with the lumen of delivery tube  26  while pushrod  61  is moved longitudinal through delivery tube  26  to eject the IOL out the distal end of the delivery tube.  FIG. 19C  illustrates that once lip  65  of top jaw  63  exits delivery tube  26  at the distal end, top jaw  63  will flex substantially back into its original position. Lip  65  can be any configuration or shape that will allow for the flexing of top jaw  63  toward bottom jaw  64 . Preferably top jaw  63  is slightly longer or longer than bottom jaw  64  to prevent the IOL from being captured between the two jaws and held after the IOL exits from the delivery tube. According to an embodiment, bottom jaw  64  may remain substantially stationary with respect to the rest of pushrod  61 . In an embodiment, the flexible top jaw  63  allows for further folding of the trailing haptic of the IOL over the optic during implantation of the IOL. The distal tip keeps the trailing haptic in a stable position. 
     In an embodiment, lip  65  may be located on the bottom jaw  64  depending upon the geometry of the IOL and/or haptic. For example, if instead of the trailing haptic being in a “C” configuration if you look at the IOL in an insertion device from the top, the trailing haptic is in reversed “C” configuration, the lip  65  may function better or properly if it is located on the bottom jaw  64 . 
     In an embodiment, the bottom jaw  64  may also flex or be capable of flexing toward top jaw  63  to allow the distal tip (or distal end) of pushrod  61  to pass through the tapered lumen of delivery tube  26 . It is also envisioned that both the top jaw  63  and bottom jaw  64  flex towards each other as the pushrod  61  is passed through the tapered lumen of delivery tube  26 . 
     Tip Protector 
     An advantage of puller cap  70  is it acts as a tip protector to prevent damage or deformation. As illustrated in  FIG. 21 , a certain amount of clearance or space is provided around the distal end of delivery tube  26  when puller cap  70  is placed onto system  20 . The clearance or space  130  is maintained by contact between the internal structures of puller cap  70  at the proximal end and system  20 . In an embodiment, clearance or space  130  between delivery tube  26  and the distal end of puller cap  70  is maintained by contact between wall  98  through window  97  shown in  FIG. 15  and wings  27  and portion  96  of lock  95 A, B shown in  FIG. 7 . It is also envisioned that other similar structures may be used to maintain clearance  130  to protect the tip of delivery tube  26 . 
     Protective Cap 
       FIGS. 22A-G ,  23 A-B,  24 ,  25 , and  26  illustrate a protective cap  200  of the present invention. Protective cap  200  has similar advantages of puller cap  70  of protecting the tip from damage or deformation. Protective cap  200  may be used instead of puller cap  70  when the trailing haptic is swept or folded by means of the pushrod or the trailing haptic does not require sweeping or folding. Protective cap  200  comprises finger grips  280 , window  289 , and port  287 . Protective cap  200  may also comprise one or more of the following: clips (or snaps)  220 , relief slots  225 , and/or guides  235 . Protective cap  200  may also comprise a fill indicator  255  and/or a material relief  265 . 
     Protective cap  200  may be made of any material known in the art, preferably polypropylene, polycarbonate, polyethylene, or polyethylene terephthalate; more preferably polypropylene and polycarbonate; most preferably polypropylene. Protective cap  200  may also be of any color, preferably translucent or clear to enable a user to visualize the features inside protective cap  200  and anything housed within protective cap  200 . Protective cap  200  may be the shape as illustrated in the embodiment in  FIGS. 22A-G , but the invention also envisions that protective cap  200  may be of any shape or size to accommodate the needs of the insertion system the protective cap is used with or the needs of the user the puller cap is designed for. For example, the protective cap may be of an arrow shape as illustrated in the embodiment in  FIG. 22B , may be more of a round shape, triangular shape, square shape, or shaped to meet the needs for shipping or handling. 
     The finger grips  280  may be of any design or configuration known in the art. According to an embodiment of the present invention, finger grips  280  may comprise a texture design or feature to ease gripping or actuation of the clip  220  and removal of protective cap  200  from an insertion system, such as system  20  as illustrated in  FIGS. 1-5 and 1A-4A . The protrusion  282  of finger grips  280  may also be of any shape, including but not limited to square, rounded, triangle, and any other shape known in the art that may assist in grasping protective cap  200 . Finger grips  280  may have inner walls that are sized and shaped to couple with at least a portion of the wings  27  that run along the longitudinal axis of cartridge  28 . The inner walls are configured and dimensioned to avoid damaging the distal end of the tip of the delivery tube  26  when protective cap  200  is placed on the insertion device. In an embodiment, finger grips  280  may have a radius of curvature that is similar to or mirrors the curvature of a user&#39;s finger to assist with gripping and removal of the protective cap  200 . 
     In an embodiment, protective cap  200  comprises tapered portion  245  (shown in  FIGS. 22B, 22G, 25, and 26 ). Tapered portion  245  may be configured and dimensioned to mirror or substantially mirror the shape and size of the cartridge and/or insertion device. In an embodiment, tapered portion  245  comprises a bevel  247  which mirrors bevel  23  (shown in  FIGS. 2, 2A, and 5 ). The internal and external walls of tapered portion  245  may also remain uniform or substantially uniform with respect to each other from the beginning of the tapered portion to at or near the distal end of cartridge such that the walls run parallel to each other. It is also envisioned that the internal walls of the tapered portion mirror the external features of the cartridge or distal end of the insertion device and the external walls of the tapered portions remain substantial linear, for example without a bevel. 
     As shown in  FIG. 24 , the distal end  285  of protective cap  200  may comprise internal bevel  270 . Internal bevel  270  is configured and dimensioned to match or substantially match or mate with the bevel of the tip (at the distal end) of delivery tube  26  of cartridge  28 . When protective cap  200  is placed on system  20 , internal bevel  270  is coupled with the bevel of the tip of delivery tube  26  of cartridge  28  and port  287 , and with its funnel feature it creates a larger opening. As discussed above, the small nature of ports can make it very difficult for doctors, nurses, and/or staff to locate openings for inserting fluids. Port  287  with internal bevel  270  enables a user to more easily direct a cannula tip  101  into a delivery tube  26  or port  87  as illustrated in  FIG. 8 . 
     As illustrated in  FIGS. 22A , C, E, and G, the distal end of protective cap  200  may also comprise a material relief  265 . Material relief  265  helps prevent distortion of the tip at the distal end of protective cap  200  during the molding process. It is also envisioned, that the distal end of the protective cap  200  does not comprise a material relief. 
     As illustrated in  FIG. 23A , protective cap  200  may also have inner walls comprising one or more internal guides  235  that run along at least a portion of the longitudinal axis and are configured and dimensioned to mate or couple with features on the outer portions of the insertion device. Internal guides  235  help keep the protective cap substantially aligned in a horizontal and vertical direction when the cap is placed on or removed. This helps to protect the distal end or tip of cartridge  28  or insertion system  20 . The internal guides  235  may be of any width or of any length suitable to couple with external features of the insertion system and/or cartridge. According to an embodiment, there may be two internal guides on the internal wall of the protective cap along the longitudinal axis, and the distance between each of the guides may be any distance as long as it matches the external features on the insertion system. In an embodiment, the distance between the guides may be about 0.374 in. (9.4996 mm) apart. The width of a guide may be between about 0.023 in. (0.5842 mm) and about 0.028 in. (0.7112 mm), preferably about 0.025 in (0.635 mm). In an embodiment, the length of a guide may be between about 0.318 in. (8.0772 mm) to about 0.386 in. (9.8044 mm). The length of a guide may also be between about 0.318 in. (8.0772 mm) and about 0.328 in. (8.3312 mm), preferably about 0.323 in. (8.2042 mm) The length of the guide may also be between about 0.376 in. (0.5504 mm) and 0.386 in. (9.8044 mm), preferably about 0.381 in. (9.6774 mm) In another embodiment, one or more guides may begin at or near the distal end of relief slot  225  (see  FIG. 23A ) and extend for a distance toward the distal end of the protective cap. 
     As discussed above, the small nature of ports can make it very difficult for doctors, nurses, and/or staff to locate openings for inserting fluids. The protective cap  200  of the present invention solves this problem by providing a larger port  287  with a funnel feature that leads into the smaller port of the insertion device. This enables a user to more easily direct a cannula tip  101  into a delivery tube  26  or port  87  as illustrated in  FIG. 8 . The protective cap may also include one or more additional ports. 
     Protective cap  200  may also have one or more windows  289  to provide the users with a visual indicator of the amount of fluid inserted into the insertion system, as well as provide viewing of the distal end of a cannula tip. The one or more windows may be located on the top, bottom or sides of the protective cap, preferably on the top or the bottom. The one or more windows may also comprise a measuring devise such as a ruler to allow a user to measure the amount of fluid inserted into the inserter. The one or more windows may also comprise a material such that when a fluid is inserted into the inserter and viewed through the window light that is emitted through the window to the fluid is polarized providing a visual indicator of the fluid within the inserter. The window  289  may also comprise a fill indicator  255  to provide a maximum fill line. 
     In order to secure protective cap  200  to an insertion system, such as the system  20  shown in  FIGS. 1 and 1A , clip  220  may be used. Clip  220  is configured and dimensioned to mate with a distal portion of wings  27  of cartridge  28  (cartridge  28  is shown in  FIG. 5 ). In an embodiment illustrated in  FIG. 25 , relief slots  225  of protective cap  200  couple with the vertical elements  29  (shown in  FIG. 5 ) of wings  27  of cartridge  28 . Relief slots  225  may be of any shape or size to couple with the shape or size of the vertical elements  29 . Clip  220  may also extend beyond the proximal end of finger grips  280  as illustrated in  FIG. 22B . 
     In an embodiment, when the protective cap  200  is placed on the distal end of the system  20 , clips  220  act as a cantilever snap by riding along the vertical elements  29  of the wings  27  of cartridge  28  until the clips  220  are over center and then snapping down over the end of the wings  27 . In an embodiment, the clip  220  is not located on the grip  280  to allow for easier removal of the protective cap. It is also envisioned that clip  220  may be located or coupled with the grip  280  depending upon the design and/or function of the clip  220  and whether the grip  280  is an extension of the clip  220 . 
       FIGS. 27A-F  and  28 A-F illustrate additional embodiments of a protective cap with similar features as shown in  FIGS. 22A-22G, 23A-23B, and 24 .  FIGS. 29A-F  and  FIGS. 30A-F  illustrate additional embodiments of a puller cap with similar features as shown in  FIGS. 6-13 . 
     Plunger Marker 
     As illustrated in  FIGS. 31A and 31B , plunger  24  may comprise a marker or indicator  310 . As discussed above, the plunger  24  and/or pushrod  61  (pushrod assembly  60 ) translates axially through an elongate passage defined within the inserter handpiece  22  and is configured to urge the IOL from a holding station  30  through the distal delivery tube  26 . In an embodiment, system  20  may operate in a push and/or twist fashion. With a push and twist mechanism, the plunger  24  may first be advanced axially along the longitudinal axis to a predetermined point and then the plunger  24  may be rotated for further advancement. Such a further advancement via rotation may provide additional control in the delivery of the IOL. In such a scenario, it would be helpful to provide an indication of when the axial translation of the plunger  24  or pushrod assembly  60  has reached the predetermined point. In such an embodiment, a marker  310  is placed on plunger  24  such that when the plunger  24  is advanced or displaced along the longitudinal axis of the system  20  a user will be able to visualize that the plunger has reached the predetermined point when marker  310  lines up with the proximal end  320  of handpiece  22  (see  FIG. 31B ) or disappears within handpiece  22  (see  FIG. 31C ). Marker  310  may be placed on any location on plunger  24  and may be of any shape, size or color. The predetermined point may be the proximal end  320  as described in the above embodiment, but it is also envisioned to be any location along the handpiece  22 . This may be possible if handpiece  22  is made of a translucent or transparent material such that marker  310  is visible through handpiece  22 . 
     Pushrod Supports 
     According to an embodiment, the present invention provides one or more guide rails to provide support for the pushrod on the distal end of the inserter body.  FIG. 32  shows a cross-sectional view of insertion system  20  with pushrod  61  and handpiece  22 . According to an embodiment, pushrod  61  may comprise one or more guide rails  395 , preferably a guide rail on opposite sides of pushrod  61 . To mate with guide rails  395 , one or more channels  396  on the upper and/or lower portions of lens holding station  30  may be included. The top and/or bottom channels  396  may be of any shape to mate with the shape of the one or more guide rails. Preferably the guide rails and channels are substantially rectangular in shape. Preferably, the lower channel is wider than the upper channel, although the width of the channels can be of any size and the channels can be of any shape. The guide rails on the pushrod mate to the channels and may have substantially the same shape. The guide rails may be on any portion of the pushrod and may make up any percentage of the pushrod. The channels may be located on other locations of the handpiece  22 , including but not limited to base  52  and/or delivery tube  26 . 
     According to an embodiment, it is also envisioned that one or more guide rails may be located on the handpiece  22  and corresponding channels may be located on the pushrod  61 . In an embodiment, the channels may be located a long a portion of the pushrod  61  and may be found on any location around the circumference of the pushrod. The one or more guide rails may be located anywhere within the handpiece such that the guide rails are configured and dimensioned to mate with the one or more channels located on the pushrod  61 . 
     Nut Lock 
     In insertion systems, advancing an IOL through a delivery tube involves a significant amount of force. To allow for advancement of an IOL from a lens storage area/holding station to a loading area the same mechanism described above can be used. For ease of use a pushing mechanism may be used to advance a lens from a storage/holding station into a delivery tube for insertion and then the same mechanism can be used to insert the IOL using a twisting mechanism. To allow for the push and twist and accommodate the high amount of force, the present invention incorporates a nut lock to prevent the pushrod from moving proximally as the pushrod is rotated to move the IOL distally. 
       FIG. 33  illustrates an embodiment of the present invention. Nut lock  102  may have an internal thread of a load bearing quality. Nut lock  102  may be cylindrical in shape and have a centrally located groove  401  that allows interlock and/or detent with external/internal features of handpiece  22 . On the distal portion of nut lock  102  there may be a series of radial keyways  402  that are capable of mating with keys (not shown) protruding inward from handpiece  22  that prevent it from counter rotating. Nut lock  102  may be made of any material known in the art, including but not limited to plastic, metal, and ceramic. Nut lock  102  may be coupled with the plunger  24  via load bearing threads and is sandwiched between plunger  24  and pushrod  61 , which may be snapped together or coupled together in any way known in the art. 
     According to an embodiment, nut lock  102  may comprise a single lead thread, but may comprise more (multiple). Nut lock  102  may also have varying thread pitch. 
     According to an embodiment, when the insertion system is delivered to a physician&#39;s office, pushrod assembly  60  is in a first position. In this first position, the pushrod assembly  60  is in its most proximal position and groove  401  of nut lock  102  mates with one or more proximal detents  407  located at or near the most proximal end of handpiece  22  and prevents accidental movement of pushrod assembly  60 . At this point, plunger  24  can be rotated in any direction without causing longitudinal movement of pushrod  61 . When the pushrod assembly is moved into a second position between the most proximal detent  407  and a second distal detent  406 , pushrod assembly  60  is movable in a longitudinal direction between detents, but rotation of plunger  24  in any direction does not longitudinally move pushrod  61 . When pushrod assembly  60  is moved distally in a longitudinal direction to a third position, wherein groove  401  of nut lock  102  mates with one or more distal detents  406  (second detent position) (see  FIG. 33A ), pushrod assembly  60  is prevented from further distal or proximal movement by pushing or pulling on end cap  40 . Once in the second detent position, the pushrod assembly cannot be pulled from this position back to the first proximal position. At this point the only way to advance pushrod  61  longitudinally to insert the IOL is to rotate plunger  24  via end cap  40  in either a clockwise or counter-clockwise direction (depending upon the configuration of the threads). This is to prevent reuse of a one time use insertion system and/or improper activation of the pushrod. 
     The detents are one way snaps (cantilever snaps) that provide the strength to prevent the pushrod assembly  60  from being pulled back from the second detent  406  (see  FIG. 33A ). The proximal detent(s)  407  also provide biasing for the proximal end of the plunger  24  as it is advanced longitudinally or rotated and provide a little resistance (see  FIG. 33B ). The proximal detents  407  may be the same or similar to the second detent  406 . The proximal detents  407  may have a different configuration or shape from the second detent  406 . The detents may be of any shape or size suitable for its function. 
     Safety Detent for Plunger Threads 
     According to an embodiment, to help prevent advancing the pushrod with rotation of plunger  24  until desired, detents  405  are added to the plunger. Detents  405  are located on the distal end or portion of plunger  24 . According to an embodiment, the detents are located within the first two to three threads of plunger  24 .  FIG. 34  illustrates detents  405  at the distal end or portion of plunger  24 . The number of detents can range between 1-6, preferably 4. 
     All references cited herein are hereby incorporated by reference in their entirety including any references cited therein. 
     The above presents a description of the best mode contemplated of carrying out the present invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains to make and use this invention. This invention is, however, susceptible to modifications and alternate constructions from that described above which are fully equivalent. Consequently, it is not the intention to limit this invention to the particular embodiments disclosed. On the contrary, the intention is to cover modifications and alternate constructions coming within the spirit and scope of the invention as generally expressed by the following claims, which particularly point out and distinctly claim the subject matter of the invention.