Abstract:
Apparatuses, systems, and methods for implanting an intraocular lens into an eye are described. For example, an intraocular lens injector may include a plunger and an injector body that includes an insertion depth guard and a nozzle extending therefrom. The insertion depth guard is disposed at a distal end of the injector body to limit a distance that the nozzle penetrates the eye. The intraocular lens injector may also include a biasing element configured to generate a counterforce to distal movement of the plunger through the injector rod. An example intraocular lens injector may include a biasing element to produce a counterforce that opposes advancement of the plunger through the injector body. The counterforce provides for a more continuous advancement of the plunger while reducing or substantially eliminating abrupt changes in the rate at which the plunger is advanced through the injector body.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 62/128,356, filed Mar. 4, 2015, and claims the benefit U.S. Provisional Application No. 62/208,064, filed Aug. 21, 2015, the entire contents of which are included herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates to systems, apparatuses, and methods for intraocular lens injectors. 
       BACKGROUND 
       [0003]    The human eye in its simplest terms functions to provide vision by transmitting and refracting light through a clear outer portion called the cornea, and further focusing the image by way of the lens onto the retina at the back of the eye. The quality of the focused image depends on many factors including the size, shape and length of the eye, and the shape and transparency of the cornea and lens. When trauma, age or disease cause the lens to become less transparent, vision deteriorates because of the diminished light which can be transmitted to the retina. This deficiency in the lens of the eye is medically known as a cataract. The treatment for this condition is surgical removal of the lens and implantation of an artificial intraocular lens (“IOL”). 
         [0004]    Many cataractous lenses are removed by a surgical technique called phacoemulsification. During this procedure, an opening is made in the anterior capsule and a thin phacoemulsification cutting tip is inserted into the diseased lens and vibrated ultrasonically. The vibrating cutting tip liquefies or emulsifies the lens so that the lens may be aspirated out of the eye. The diseased lens, once removed, is replaced by an artificial lens. 
         [0005]    The IOL is injected into the eye through the same small incision used to remove the diseased lens. An IOL injector is used to deliver an IOL into the eye. 
       SUMMARY 
       [0006]    According to one aspect, the disclosure describes an intraocular lens injector that may include an injector body, and a plunger slideable within a bore formed in the injector body. The injector body may include the bore, an interior wall defining the bore, an insertion depth guard disposed at a distal end of the injector body, and a nozzle extending distally beyond the insertion depth guard. The insertion depth guard may include a flanged surface. 
         [0007]    Another aspect of the disclosure encompasses an intraocular lens injector. The intraocular lens injector may include an injector body and a plunger. The injector body may include a bore defined by an interior wall and a nozzle formed at a distal end of the injector body. The plunger may be slideable in the bore and may include a plunger tip. The tip may include a first groove and a second groove nested within the first groove. 
         [0008]    Another aspect of the disclosure encompasses an intraocular lens injector that includes an injector body and a plunger. The injector body includes a bore defined by an interior wall and a nozzle formed at a distal end of the injector body. The plunger is slideable in the bore and includes a plunger tip and a longitudinal axis. The plunger tip includes a first protrusion extending distally from a first side of the plunger tip and a hinge disposed at a proximal end of the first protrusion. The first protrusion extends at an oblique angle relative to the longitudinal axis and pivotable about the hinge. 
         [0009]    The various aspects may include one or more of the following features. The flanged surface may be a curved surface. The curved surface may be a spherical surface. The plunger may include a body portion and a biasing element disposed adjacent to a proximal end of the body portion. The biasing element may be deformable upon engagement with the injector body to produce a force resistive to further advancement of the plunger through the bore. The biasing element may include a channel, and wherein the body portion of the plunger may extend through the channel. The injector body may include a tab formed at a proximal end thereof, a groove extending through the tab, and an aperture aligned with the groove. The intraocular lens injector may also include a plunger stop. The plunger stop may include a protrusion. The plunger stop may be removably received in the groove such that the protrusion extends through the aperture and into a slot formed in the plunger. The plunger may include a cantilevered member. The bore may include a shoulder, and the aperture formed in the injector body may align with the slot formed in the plunger when the cantilevered member engages the shoulder. 
         [0010]    The various aspects may also include one or more of the following features. The injector body may include a compartment in communication with the bore. The compartment and the bore may be coupled together at an interface. The interior wall may include a tapered portion that defines an opening that provides communication between the bore and the compartment. The interior wall may include a flexible wall portion disposed at the opening. The plunger may include a plunger rod, and the compartment may include a receiving surface adapted to receive an intraocular lens. The receiving surface may include a contoured ramp disposed distally from the opening. The flexible wall portion may be configured to align the plunger rod within the opening. The contoured ramp may be configured to deflect the plunger rod in a second direction opposite the first direction as the plunger rod is advanced through the compartment. The plunger may include a cantilevered member, and the cantilevered member may deflectively engage the interior wall of the bore as the plunger is advanced through the bore. 
         [0011]    The various aspects may include one or more of the following features. The second groove may be formed at a first end of the first groove. A second end of the first groove opposite the first end may be configured to capture a trailing haptic of an intraocular lens disposed in the injector body, and the second groove may be adapted to capture a proximal end of an optic of the intraocular lens. The plunger may include a plunger rod, and at least a portion of the plunger rod may be angularly offset from a longitudinal axis of the plunger rod. The injector body may include an insertion depth guard disposed at a distal end of the injector body, and the insertion depth guard may include a flanged surface. A cross-sectional dimension of the insertion depth guard may be larger than a cross-sectional dimension of the nozzle. The flanged surface may be a curved surface. The plunger may include a biasing element disposed adjacent to a proximal end of the plunger. The biasing element may be deformable upon engagement with the injector body to produce a force resistive to further advancement of the plunger through the bore. The biasing element may include a channel, and wherein the body portion of the plunger may extend through the channel. A first groove may be disposed adjacent to second protrusion and adapted to receive an optic of an intraocular lens. 
         [0012]    It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory in nature and are intended to provide an understanding of the present disclosure without limiting the scope of the present disclosure. In that regard, additional aspects, features, and advantages of the present disclosure will be apparent to one skilled in the art from the following detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a perspective view of an example intraocular lens injector. 
           [0014]      FIG. 2  shows a longitudinal cross-sectional view of the intraocular lens injector of  FIG. 1 . 
           [0015]      FIG. 3  is a perspective view of a distal portion of an example injector body of the intraocular lens injector of  FIG. 1 . 
           [0016]      FIG. 4  is a cross-sectional view of the distal portion of the injector body shown in  FIG. 3 . 
           [0017]      FIG. 5  is an example cross-sectional shape of a nozzle of an intraocular lens injector. 
           [0018]      FIG. 6  shows an intraocular lens injector partially inserted into an eye. 
           [0019]      FIG. 7  shows a construction method for defining a flanged surface of an insertion depth guard of an example intraocular lens injector. 
           [0020]      FIG. 8  shows a cross-sectional view of an intraocular lens receiving compartment formed in an injector body. 
           [0021]      FIG. 9  shows a perspective view of an intraocular lens receiving compartment formed in an injector body. 
           [0022]      FIG. 10  is a cross-sectional view of a plunger. 
           [0023]      FIG. 11  is a bottom view of a plunger. 
           [0024]      FIG. 12  is a partial perspective view showing tabs and a plunger lock of an example intraocular lens injector. 
           [0025]      FIG. 13  is a detail view of an example plunger tip of plunger. 
           [0026]      FIG. 14  shows an example interior surface of a door enclosing a lens-receiving compartment of an intraocular lens injector. 
           [0027]      FIG. 15  shows deformation experienced by an example spring during advancement of a plunger of an intraocular lens injector. 
           [0028]      FIG. 16  is a detail view of a plunger with another example biasing element design. 
           [0029]      FIG. 17  illustrates a plunger having yet another example biasing element design. 
           [0030]      FIG. 18  shows another plunger with a further example biasing element design. 
           [0031]      FIG. 19  is a detail view of the distal end of the IOL injector showing a demarcation designating a pause position of an IOL being advanced through the IOL injector. 
           [0032]      FIG. 20  is a view of a distal end  60  of an IOL injector with an IOL located therein at a pause position. 
           [0033]      FIG. 21  is a detail view of an example IOL injector showing an opening at an interface between a compartment into which an IOL is received and an internal bore of an injector body, the detail view being transverse to a longitudinal axis of the IOL injector, and the detail view showing a flexible wall portion in contact with an injector rod. 
           [0034]      FIG. 22  is a partial cross-sectional view of an example IOL injector. 
           [0035]      FIGS. 23-24  show an example advancement stop coupled to a plunger. 
           [0036]      FIGS. 25-26  show another example advancement stop coupled to a plunger. 
           [0037]      FIG. 27  shows an example IOL. 
           [0038]      FIG. 28  is a perspective view of an example plunger tip. 
           [0039]      FIG. 29  is a side view of the example plunger tip of  FIG. 28 . 
           [0040]      FIG. 30  is a top view of the example plunger tip of  FIG. 28 . 
       
    
    
     DETAILED DESCRIPTION 
       [0041]    For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the implementations illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the disclosure is intended. Any alterations and further modifications to the described devices, instruments, methods, and any further application of the principles of the present disclosure are fully contemplated as would normally occur to one skilled in the art to which the disclosure relates. In particular, it is fully contemplated that the features, components, and/or steps described with respect to one implementation may be combined with the features, components, and/or steps described with respect to other implementations of the present disclosure. 
         [0042]    The present disclosure relates to systems, apparatuses, and methods for delivering an IOL into an eye.  FIGS. 1 and 2  show an example IOL injector  10  that includes an injector body  20  and a plunger  30 . The injector body  20  defines a bore  40  extending from a proximal end  50  of the injector body  20  to a distal end  60  of the injector body  20 . The plunger  30  is slideable within the bore  40 . Particularly, the plunger  30  is slideable within bore  40  in order to advance an IOL, such as IOL  70 , within the injector body  20 . The IOL injector  10  also includes a longitudinal axis  75 . The longitudinal axis  75  may extend along the plunger  30  and define a longitudinal axis of the plunger  30 . 
         [0043]    The injector body  20  includes a compartment  80  operable to house an IOL prior to insertion into an eye. In some instances, a door  90  may be included to provide access to the compartment  80 . The door  90  may include a hinge  100  such that the door  90  may be pivoted about the hinge  100  to open the compartment  80 . The injector body  20  may also include tabs  110  formed at the proximal end  50  of the injector body  20 . The tabs  110  may be manipulated by fingers of a user, such as an ophthalmologist or other medical professional, to advance the plunger  30  through the bore  40 . 
         [0044]      FIGS. 3-5  illustrate details of the distal end  60  of the injector body  20 . In some instances, the distal end  60  has a tapered exterior surface. Further, the distal end  60  includes a passage  64  that tapers towards a distal opening  125 . The injector body  20  also includes a nozzle  120  at the distal end  60 . The nozzle  120  is adapted for insertion into an eye so that an IOL may be implanted. An IOL is expelled from distal opening  125  formed in the nozzle  120 . As shown in  FIG. 5 , the nozzle  120  may have an elliptical cross section. Additionally, the nozzle  120  may include a beveled tip  130 . The compartment  80 , passage  64 , and opening  125  may define a delivery passage  127 . A size of the delivery passage  127  may vary along its length. That is, in some instances, a height H 1  of the passage may change along a length of the delivery passage  127 . The variation in size of the delivery passage  127  may contribute to the folding of the IOL as it is advanced therealong. 
         [0045]    In some instances, the injector body  20  may include an insertion depth guard  140 . The insertion depth guard  140  may form a flanged surface  150  that is adapted to abut an exterior eye surface. The insertion depth guard  140  abuts an eye surface and, thereby, limits an amount by which the nozzle  120  is permitted to extend into an eye. In some implementations, the flanged surface  150  may have a curvature that conforms to the outer surface of an eye. For example, the flanged surface  150  may have a curvature that conforms to a scleral surface of the eye. In other instances, the flanged surface  150  may have a curvature that corresponds to a corneal surface of the eye. In still other instances, the flanged surface  150  may have a curvature, part of which corresponds to a scleral surface and another part that corresponds to a corneal surface. Thus, the flanged surface  150  may be concave. In other instances, the flanged surface  150  may be flat. In still other instances, the flanged surface  150  may be convex. Further, the flanged surface  150  may have any desired contour. For example, the flanged surface  150  may be a curved surface having radii of curvature that vary along different radial directions from a center of the flanged surface  150 . In still other instances, the flanged surface  150  may define a surface that has varying curvature along different radial directions as well as curvature that varies along one or more particular radial directions. 
         [0046]    In  FIG. 3 , the insertion depth guard  140  is shown as a continuous feature that forms a continuous flanged surface  150 . In some implementations, the insertion depth guard  140  may be segmented into a plurality of features or protrusions forming a plurality of eye-contacting surfaces. These eye-contacting surfaces may work in concert to control the depth to which the nozzle  120  may penetrate an eye. In other implementations, the insertion depth guard  140  may be omitted. 
         [0047]    An example implementation of the insertion depth guard  140  is shown in  FIGS. 6-7 . In  FIG. 6 , the IOL injector  10  is shown with the nozzle  120  inserted into an eye  151  through a wound  152  formed in the eye. Thus, as explained above, the flanged surface  150  of the insertion depth guard  140  may be spherical in nature in order to conform to the eye  151  when the nozzle  120  is fully inserted thereinto. 
         [0048]      FIG. 7  shows a side view of the distal portion of the IOL injector  10  showing an example layout for defining a shape of the flanged surface  150 . In this illustrated example, the surface is defined to be spherical in nature. Thus, in some instances, the flanged surface may be described as a “spherical surface” which is understood to mean a surface that conforms to a sphere. A spherical surface of the flanged surface  150  may approximate the shape of an eye. However, a spherical surface is provided only as an example. Thus, the shape of the flanged surface  150  may be any desired shape. 
         [0049]    As shown, a center  153  for use in defining a spherical surface of the flange surface  150  may be located relative to the nozzle  120  of the IOL injector  10 . A center  153  of the spherical surface may be located to produce, for example, a desired length  154  of the nozzle  120  that extends beyond the flanged surface  150  and, thus, into an eye. 
         [0050]    The injector body  20  may include a tapered portion  155 . The nozzle  120  and tapered portion  155  meet at a location  156 . A horizontal position of the center  153  may be made in reference to the location  156 . For example, a horizontal displacement  157  of the center  153  from location  156  may be in the range of 7.6 mm to 8.0 mm. Accordingly, in some implementations, the center  153  may have a horizontal displacement of 7.6 mm, 7.7 mm, 7.8 mm, 7.9 mm, or 8.0 mm. A vertical position of the center  153  may be defined by a vertical distance  158  from the longitudinal axis  75 . In some instances, the vertical displacement  158  may be 2.3 mm to 2.7 mm. Thus, in some implementations, the center  153  may have a horizontal displacement of 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, or 2.7 mm. However, it is noted that the ranges of the horizontal displacement  157  and the vertical displacement  158  of the center  153  are provided only as examples. Thus, the values of the horizontal displacement  157  and vertical displacement  158  of the center  153  may greater or smaller than the examples provided or any value in between. Moreover, the horizontal displacement  157  and vertical displacement  158  may be any desired length. 
         [0051]    In some implementations, a radius  159  of spherical surface  160  may be sized to correspond to a radius of an eye. In some instances, the radius  159  may be within the range of 7.5 mm to 8.1 mm. Thus, the radius may be 7.5 mm, 7.6 mm, 7.7 mm, 7.8 mm, 7.9 mm, 8.0 mm, or 8.1 mm. These values are provided only as examples. Accordingly, it is within the scope of the disclosure that the radius  159  may be greater or smaller than the values provided or any value in between. Consequently, the value of radius  159  may be any desired value. 
         [0052]    The values of the horizontal displacement  157 , vertical displacement  158 , and radius  159  may be selected to produce a nozzle length  154  of any desired size. For example, in some instances, these values may be selected to produce a nozzle length  154  of between 1.0 mm and 5.0 mm. In some implementations, the length of the nozzle  120  may be 2.0 mm. In other instances, the length of the nozzle  120  may be 3.0 mm. In some instances, the nozzle  120  may be 4.0. In still other instances, the length of the nozzle  120  may be 5.0 mm. However, the scope of the disclosure is not so limited. Rather, the length of the nozzle  120  may be greater or less than the values presented or any value in between. Moreover, the length of nozzle  120  may be any desired length. 
         [0053]      FIG. 8  shows a cross-sectional detail view of the compartment  80  and a portion of bore  40  of the example injector body  20  shown in  FIG. 2 . The bore  40  is defined by an interior wall  298 . The interior wall  298  includes a tapered portion that includes a first tapered wall  301  and a second tapered wall  303 . The tapered portion of the interior wall  298  defines an opening  170  at an interface  172  between the bore  40  and the compartment  80 . The opening  170  includes a height H 1 . The distal end portion  211  of the plunger rod  210  has a height of H 2 . In some instances, height H 1  may be larger than height H 2 , such that, initially, there is no interference between the plunger rod  210  and the interior wall  298  at the opening  170 . In other instances, height H 1  may be equal to or larger than height H 2 , such that the plunger rod  210  and the opening  170  initially have an interference fit. In some implementations, the first tapered wall  301  includes a flexible wall portion. In the example shown, the flexible wall portion  162  is an obliquely-extending, flexible portion of the interior wall  298  and, particularly, of the first tapered wall  301 . As shown in  FIG. 9 , in some instances, portions of the first tapered wall  301  are removed, forming voids  163  that flank the flexible wall portion  162 . Thus, in some instances, the flexible wall portion  162  may extend in a cantilevered manner. 
         [0054]    Referring again to  FIG. 8 , in some instances, the flexible wall portion  162  may be sloped toward the distal end  60  of the injector body  20 . In some instances, an angle B defined by the flexible wall portion  162  and the longitudinal axis  75  may be in the range of 20° to 60°. For example, in some instances, the angle B may be 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, or 60°. Further, the angle B may be greater or smaller than the defined range or anywhere within the recited range. Moreover, the scope of the disclosure is not so limited. Thus, the angle B may be any desired angle. 
         [0055]    The injector body  20  may also include a contoured ramp  180  formed along an interior receiving surface  190  of the compartment  80 . Generally, the interior receiving surface  190  is the surface on which an IOL, such as IOL  70 , is placed when loaded into the IOL injector  10 .  FIG. 9  is a perspective view of a portion of the example injector body  20  shown in  FIG. 2 . The door  90  is not shown. In some instances, a vertical distance C between a tip of the flexible wall portion  162  and the top of the contoured ramp  180  may correspond with a height H 2  of a distal end portion  211  of the plunger rod  210 . In other instances, the distance C may be greater or less than the height H 2  of the distal end portion  211  of the plunger rod  210 . The flexible wall portion  162  and contoured ramp  180  are discussed in more detail below. 
         [0056]    As also shown in  FIG. 9 , the injector body  20  may include a contoured surface  192  that is offset from the receiving surface  190 . A wall  194  is formed adjacent to the contoured surface  192 . A freely extending end  452  of a haptic  450  contacts the contoured surface  192  when IOL  70  is received into the compartment  80 . 
         [0057]    Referring to  FIGS. 1 and 10-11 , the plunger  30  may include a body portion  200 , a plunger rod  210  extending distally from the body portion  200 , and a plunger tip  220  formed at a distal end  230  of the plunger rod  210 . The plunger  30  may also include a flange  240  formed at a proximal end  250  of the body portion  200 . A biasing element  260  may be disposed on the plunger  30 . In some instances, the biasing element  260  may be a spring. In some implementations, the biasing element  260  may be disposed adjacent to the flange  240 . A proximal end  262  may be fixedly attached at the body portion adjacent to the flange  240 . In other instances, the biasing element  260  may be disposed at another location along the body portion  200 . In still other implementations, the biasing element  260  may be formed or otherwise disposed on the injector body  20  and adapted to engage the plunger  30  at a selected location during advancement of the plunger  30  through bore  40 . 
         [0058]    The flange  240  may be used in concert with the tabs  110  to advance the plunger  30  through the injector housing  20 . For example, a user may apply pressure to tabs  110  with two fingers while applying opposing pressure to the flange  240  with the user&#39;s thumb. A surface of the flange  240  may be textured in order to provide positive gripping by a user. In some instances, the texture may be in the form of a plurality of grooves. However, any desired texture may be utilized. 
         [0059]    The body portion  200  may include a plurality of transversely arranged ribs  270 . In some instances, the ribs  270  may be formed on both a first surface  280  and a second surface  290  of the body portion  200 . In other instances, the ribs  270  may be formed on only one of the first surface  280  and second surface  290 . A longitudinally extending rib  300  may also be formed on one or both of the first and second surfaces  280 ,  290 . 
         [0060]    In some instances, the body portion  200  may also include one or more protrusions  202 , as shown in  FIG. 11 . The protrusions  202  may extend longitudinally along a length of the body portion  200 . The protrusions  202  may be received grooves  204  formed in the injector body  20 , as shown in  FIG. 1 . The protrusions  202  and grooves  204  interact to align the plunger  30  within the bore  40  of the injector body  20 . 
         [0061]    The body portion  220  may also include cantilevered members  292 . The cantilevered members  292  may extend from a proximal end  294  of the body portion  200  towards the distal end  250 . The cantilevered members  292  may include flared portions  296 . The cantilevered members  292  may also include substantially horizontal portions  297 . The flared portions  296  are configured to engage the interior wall  298  of the injector body  20  that defines the bore  40 , as shown in  FIG. 2 . Engagement between the cantilevered members  292  and the interior wall  298  generates a force resistive to advancement of the plunger  30  and provides a tactile feedback to the user during advancement of the plunger  30 . For example, in some implementations, the resistive force generated by contact between the cantilevered members  292  and the interior wall  298  may provide a baseline resistance that resists advancement of the plunger  30 . 
         [0062]    In some instances, the plunger rod  210  may include an angled portion  212 . The distal end portion  211  may form part of the angled portion  212 . The angled portion  212  may define an angle, A, within the range of 1° to 5° with the longitudinal axis  75 . In some instances, the angle A maybe 2°. In some instances, the angle A may be 2.5°. In still other instances, the angle A may be 3°, 3.5°, 4°, 4.5°, or 5°. Further, while the above values of A are provided as examples, the angle A may be greater or less than the indicated range or any value in between. Thus, the angle A may be any desired angle. 
         [0063]    The angled portion  212  ensures that the plunger tip  220  contacts and follows the receiving surface  190  as the plunger  30  is advanced through the bore  40 . Particularly, the angle A defined by the angled portion  212  exceeds what is needed to cause the plunger tip  220  to contact the interior wall  298  of the bore  40 . That is, when the plunger  30  is disposed within the bore  40 , engagement between the plunger tip  220  and the interior wall  298  causes the angled portion  212  to bend inwardly due to the angle A. Consequently, the angled portion  212  ensures that the plunger tip  220  properly engages the haptics and optic of an IOL being inserted from the IOL injector  10 . This is described in greater detail below. Although the angled portion  212  is shown as being a substantially straight portion bent at an angle relative to the remainder of the plunger rod  210 , the scope is not so limited. In some instances, a portion of plunger rod  210  may have a continuous curvature. In other instances, an entire length of the plunger rod  210  may be bent or have a curvature. Further, the amount of angular offset from the longitudinal axis  75  or amount of curvature may be selected in order to provide a desired amount of engagement between the plunger tip  220  and the interior surfaces of the injector body  20 . 
         [0064]    The biasing element  260  may be affixed to the body portion  200  adjacent to the flange  240 . In some instances, the biasing element  260  may form a hoop  310  extending distally along the body portion  200  that functions as a spring to resist advancement of the plunger  30  when the hoop  310  engages the injector body  20 . The biasing element  260  may also include a collar  261  channel  320  through which the body portion  200  extends. Thus, in operation, as the plunger  30  is advanced through the bore  40  of the injector body  20  (i.e., in the direction of arrow  330 ), a distal end  265  of the biasing element  260  contacts the proximal end  50  of the injector body  20  at a selected location along the stroke of the plunger  30 . As the injector  30  is further advanced, the biasing element  260  is compressed and the channel  320  permits the distal end  265  of the biasing element  260  to move relative to the body portion  200 . Similarly, the channel  320  permits relative movement between the body portion  200  and the distal end  265  of the biasing element  260  during proximal movement of the plunger  30  (i.e., in the direction of arrow  340 ). 
         [0065]    The biasing element  260  in the form of hoop  310 , shown, for example, in  FIG. 2 , is provided merely as an example. The biasing element  260  may have other configurations. For example,  FIG. 16  illustrates a biasing element having elongated elliptical or oval members  1600  disposed on opposite sides of the body portion  200  of the plunger  30  and attached to the flange  240 .  FIG. 17  shows another example configuration of the biasing element  260 . In  FIG. 17 , the biasing element  260  is in the form of curved, cantilevered members  1700  provided on opposing sides of the body portion  200  of the plunger  30 . The cantilevered members  1700  are attached to the flange  240 .  FIG. 18  shows an example in which the biasing element  260  is integrated into the body portion  200  of the plunger  30 . The biasing element  260  includes arcuate members  1800  that engage an interior wall that defines the bore  40  of the injector body  20 . While some examples are provided, the scope of the disclosure is not so limited. Rather, biasing elements having other forms and configurations are included within the scope of the disclosure. 
         [0066]    Referring to  FIGS. 2, 11, and 12 , the IOL injector  10  may also include a plunger lock  350 . The plunger lock  350  is removably disposed in a groove  360  formed in one of the tabs  110 . The plunger lock  350  includes a protrusion  370  formed at one end thereof. The plunger lock  350  may include a single protrusion  370 , as shown in  FIG. 2 . In other instances, the plunger lock  350  may include a plurality of protrusions  370 . For example,  FIG. 12  illustrates an example plunger lock  350  having two protrusions  370 . In other instances, the plunger lock  350  may include additional protrusions  370 . 
         [0067]    When installed, the protrusion  370  extends through an aperture  375  formed in the injector body  20  and is received into a slot  380  formed in the plunger  30 . When the plunger lock  350  is installed, the protrusion  370  and slot  380  interlock to prevent the plunger  30  from moving within the bore  40 . That is, the installed plunger lock  350  prevents the plunger  30  from being advanced through or removed from the bore  40 . Upon removal of the plunger lock  350 , the plunger  30  may be freely advanced through the bore  40 . In some instances, the plunger lock  350  may include a plurality of raised ribs  390 . The ribs  390  provide a tactile resistance to aid in removal from and insertion into groove  360 . 
         [0068]    The plunger lock  350  may be U-shaped and define a channel  382 . The channel  382  receives a portion of the tab  110 . Further, when fitted onto the tab  110 , a proximal portion  384  of the plunger lock  350  may be outwardly flexed. Consequently, the plunger lock  350  may be frictionally retained on the tab  110 . 
         [0069]    Referring to  FIGS. 2 and 10 , in some implementations, the body portion  20  may include shoulders  392  formed in bore  40 . The shoulders  392  may be formed at a location in the bore  40  where the bore  40  narrows from an enlarged proximal portion  394  and a narrower distal portion  396 . In some instances, the shoulder  392  may be a curved surface. In other instances, the shoulder  392  may be defined a stepped change in the size of bore  40 . 
         [0070]    The cantilevered members  292  may engage the shoulder  392 . In some implementations, the flared portion  296  of the cantilevered members  292  may engage the shoulder  392 . In some instances, a location at which the cantilevered members  292  engage the shoulder  392  may be one in which the slot  380  aligns with the aperture  375 . Thus, in some implementations, engagement between the cantilevered members  292  and shoulder  392  may provide a convenient arrangement for insertion of the plunger lock  350  to lock the plunger  30  in place relative to the injector body  20 . In other implementations, the slot  380  and the aperture  375  may not align when the cantilevered members  292  engage the shoulder  392 . 
         [0071]    As the plunger  30  is advanced through the bore  40 , the flared portion  296  of the cantilevered members  292  may be inwardly displaced to comply with the narrowed distal portion  396  of the bore  40 . As a result of this deflection of the flared portion  296 , the cantilevered members  292  apply an increased normal force to the interior wall  298  of the bore  40 . This increased normal force generates a frictional force that resists advancement of the plunger  30  through bore  40 , thereby providing tactile feedback to the user. 
         [0072]    Referring to  FIGS. 1 and 2 , the IOL injector may also include an IOL stop  400 . The IOL stop  400  is received into a recess  410  formed in an outer surface  420  the door  90 . The IOL stop  400  may include a protrusion  430  that extends through an opening  440  formed in the door. The protrusion  430  extends between a haptic and optic of an IOL loaded into the compartment  80 . As shown in  FIGS. 1 and 27 , the IOL  70  includes haptics  450  and an optic  460 . The protrusion  430  is disposed between one of the haptics  450  and the optic  460 . The IOL stop  430  may also include a tab  435 . The tab  435  may be gripped by a user for removal of the IOL stop  430  from the injector body  20 . 
         [0073]    The IOL stop  400  may also include an aperture  470 . The aperture  470  aligns with another opening formed in the door  90 , for example opening  472  shown in  FIG. 19 . The aperture  470  and second opening  472  in the door  90  form a passageway through which a material, such as a viscoelastic material, may be introduced into the compartment  80 . 
         [0074]    The IOL stop  400  is removable from the door  90 . When installed, the IOL stop  400  prevents advancement of the IOL, such as IOL  70 . Particularly, if advancement of the IOL  70  is attempted, the optic  460  contacts the protrusion  430 , thereby preventing advancement of the IOL  70 . 
         [0075]      FIG. 13  shows an example plunger tip  220 . The plunger tip  220  may include a first protrusion  480  and a second protrusion  490  extending from opposing sides. The first and second protrusions  480 ,  490  define a first groove  500 . The first groove  500  defines a surface  502 . A second groove  510  is formed within the first groove  500 . The first groove  500 , particularly in combination with the first protrusion  480 , serves to capture and fold a trailing haptic of an IOL. The second groove  510  functions to capture and fold an optic of an IOL. 
         [0076]    A side wall  520  of the plunger tip  220  may be tapered. The tapered side wall  520  may provide a nesting space for a gusseted portion of the trailing haptic of an IOL. The gusseted portion of the haptic tends to remain proximal to the IOL optic. Thus, the tapered side wall  520  may provide a nesting space that promotes proper folding of the IOL during delivery into an eye. 
         [0077]      FIGS. 28-30  show another example plunger tip  220 . This plunger tip  220  includes a first protrusion  600 , a second protrusion  602 , and a groove  604 . The first protrusion extends at an oblique angle θ from longitudinal axis  606 . In some instances, the angle θ may be between 25° to 60°. In other instances, the angle θ may be lower than 25° or larger than 60°. In other instances, the angle θ may be between 0° to 60°. In still other implementations, the angle θ may be between 0° and 70°; 0° and 80°; or 0° and 90°. Generally, the angle θ may be selected to be any desired angle. For example, the angle θ may selected based on one or more of the following: (1) a size, such as a height, of passage  64  formed within the nozzle  60 ; (2) the height of the compartment  80 ; (3) how the height of the passage  64  and/or compartment varies along their respective lengths; and (3) the thickness of the plunger tip  220 . The second protrusion  602  may include a tapered portion  608 . The tapered portion  608  is operable to engage an optic of an IOL, such as optic  460  shown in  FIG. 27 . The optic may slide along the tapered surface so that the optic may be moved into the groove  604 . As a result, the second protrusion  602  is positioned adjacent to a surface of the optic. 
         [0078]    The example plunger tip  220  shown in  FIGS. 28-30  also include a surface  610  that may be similar to the surface  502 . The surface  610  is adapted to contact and displace a trailing or proximally extending haptic, such as haptic  450  shown in  FIG. 27 , so that the haptic folds. In some instance, the surface  610  may be a flat surface. In other instances, the surface  610  may be a curved or otherwise contoured surface. The example plunger tip  220  may also include a side wall  612  and support surface  613 . Similar to the side wall  520 , the side wall  612  may be tapered, as shown in  FIG. 30 . In some instances, the side wall  612  may include a first curved portion  614 . The first curved portion  614  may receive a bent portion of the trailing haptic that remains proximal to the optic during folding. The trailing haptic is supported by support surface  613  during the folding process. The side wall  612  may also include a second curved surface  615 . 
         [0079]    The obliquely-extending first protrusion  600  effectively increases a height H 2 , as compared to the plunger tip  220  shown in  FIG. 13 , for example. This increased height H 2  improves the ability of the plunger tip  220  to capture the trailing haptic during advancement of the plunger  30 . In operation, as the plunger  30  is advanced distally, the distal end  618  engages an interior wall of the delivery passage  127  due to changes in the height H 1  of the delivery passage  127 . As the height H 1  decreases, the first protrusion  600  pivots about hinge  620 , effectively reducing the total height H 2  of the plunger tip  220 . As the first protrusion  600  pivots about hinge  620  and rotated in a direction towards the second protrusion  602 , the first protrusion  600  captures the trailing haptic between the optic of the IOL and the first protrusion  600 . Therefore, with the first protrusion  600  pivotable about the hinge  620 , the size of the plunger tip  220  is able to adapt and conform to the changing height H 1  of the delivery passage  127  as the IOL is advanced distally and folded. 
         [0080]      FIG. 14  shows an interior surface  530  of door  90 . The surface  510  may include a ridge  530 . The ridge  530  may include a curved portion  540 . In the example illustrated, the curved portion  540  extends proximally and inwardly towards the longitudinal axis  75 . The curved portion  540  is configured to overlay a portion of a trailing haptic of an IOL, which promotes proper folding of the IOL when the plunger  30  is advanced through the injector body  20 . 
         [0081]    In operation, the plunger lock  350  may be inserted into the groove  360  to lock the plunger  30  in position relative to the injector body  20 . An IOL, such as IOL  70 , may be loaded into the compartment  80 . For example, the door  90  may be opened by a user and a desired IOL inserted into the compartment  80 . The door  90  may be closed upon insertion of the IOL into the compartment  80 . In some instances, an IOL may be preloaded during manufacturing. 
         [0082]    The IOL stop  400  may be inserted into the recess  410  formed in the door  90 . Viscoelastic material may be introduced into the compartment  80  via the aligned aperture  470  and corresponding opening formed in the door  90 . The viscoelastic material functions as a lubricant to promote advancement and folding of the IOL during advancement and delivery of the IOL into an eye. In some instances, the viscoelastic material may be introduced into the compartment  80  at the time of manufacturing. 
         [0083]    The IOL stop  400  may be removed from the recess  410  formed in the door  90 , and the plunger lock  350  may be removed from the groove  360 . The plunger  30  may be advance through the bore  40 . Sliding engagement between the cantilevered members  292  and the interior wall  298  of the injector body  20  generates a resistive force that resists advancement of plunger  30 . In some instances, the plunger  30  may be advanced through the bore  40  until the plunger tip  220  extends into the compartment  80 . For example, the plunger  30  may be advanced until the plunger tip  220  is adjacent to or in contact with the IOL. In other instances, the plunger  30  may be advanced through the bore  40  such that the IOL is partially or fully folded. Further, the plunger  30  may advance the IOL to a position within the nozzle just short of being ejected from the distal opening  125 . For example, in some instances, advancement of the plunger  30 , prior to insertion of the nozzle  120  into a wound formed in the eye, may be stopped at the point where the distal end  265  of the biasing element  260  contacts the proximal end  50  of the injector body  20 , as shown in  FIG. 15 . 
         [0084]    Advancement of the plunger  30  through the injector body  20  is discussed below with reference to  FIGS. 1, 8, and 13 . In some instances, dimensional tolerances between the plunger  30  and the injector body  20  may permit relative movement between the plunger  30  and the injector body  20  such that the distal end portion  211  is able to move within bore  40  in the direction of arrows  471 ,  472  (referred to hereinafter as “tolerance movement”). In instances, particularly those in which the plunger  30  includes angled portion  212 , the plunger tip  220  normally remains in contact with the interior wall  298  even if the plunger  30  experiences tolerance movement as the plunger  30  advances through bore  40 . Thus, in some instances, notwithstanding any tolerance movement, the plunger tip  220  remains in contact with the interior wall  298 . Accordingly, the second tapered wall  303  directed and centers the plunger tip  220  into the opening  170 . 
         [0085]    If the plunger  30  experiences tolerance movement such that the plunger tip  220  no longer contacts the interior wall  298  of the bore  40 , the first tapered wall  301 , which includes the flexible wall portion  162 , directs and centers the plunger tip  220  into the opening  170  formed at the interface  172 , resulting in contact between the plunger tip  220  and the second tapered wall  303 . When the plunger  30  becomes fully engaged with the injector body  20 , the tolerance movement is substantially reduced or eliminated, ensuring that the plunger tip  220  remains engaged with the second tapered wall  303  and contoured ramp  180 . In some instances, full engagement between the plunger  30  and the injector body  20  occurs when the cantilevered members  292  are fully engaged with the interior wall  298  of the bore  40 . Consequently, in instances where tolerance movement may exist, upon full engagement between the plunger  30  and the injector body  20 , the flexible wall portion  162  no longer influences the position of the plunger  30 . In any case, once the plunger tip  220  advances through opening  170 , the flexible wall portion  162  no longer affects the directional path of plunger  30  nor any part thereof. 
         [0086]    As the plunger tip  220  is advanced through the compartment  80  in sliding contact with the receiving surface  190 , the first groove  500  of the plunger tip  220  is positioned to engage the trailing haptic of IOL, such as trailing haptic  450  of IOL  70 , as shown in  FIG. 8 . As the plunger tip  220  is further advanced, the plunger tip  220  encounters the contoured ramp  180  and is forced vertically towards the door  90 . This vertical displacement of the plunger tip  220 , while remaining in contact with the receiving surface  190 , both folds the trailing haptic up over the optic of the IOL as well as align the second groove  510  of the plunger tip  220  with a trailing edge of the haptic. Particularly, the surface  502  of the plunger tip  220  contacts and displaces the haptic  450  as the plunger tip  220  is passed along the contoured surface  180 , thereby folding the trailing haptic  450 . As the trailing haptic  450  folds, the contoured surface  192  and wall  194  work in concert to both locate the freely extending end  452  of the trailing haptic  450  above and over the optic  460 . The profile of the contoured surface  192  operates to lift the trailing haptic  450  as the plunger tip  220  is displaced towards the distal end  60  of the injector body  20 . The wall  194  constrains lateral movement of the freely extending end  452  of the trailing haptic  450 , which cause the haptic to move distally relative to the optic  460 . Consequently, the trailing haptic  450  is both raised above and folded over the optic  460  as the plunger tip  220  contacts the trailing haptic  450  and follows along the contoured ramp  180 . As the plunger tip  220  is further advanced, the second groove  510  accepts the trailing edge of the optic  460 , and the plunger tip  220  is displaced vertically away from the door  90  due to a combination of influences from both the decreasing slope of the contoured ramp  180  and the angled portion  212  of the plunger rod  210 . Movement of the plunger tip  220  in the manner described provides for improved engagement and folding of the IOL  70 . 
         [0087]      FIG. 19  is a detail view of a portion of the distal end  60  of the injector body  20 . The distal end  60  includes a tapered portion  62  and the insertion depth guard  140 . The distal end  265  of the biasing element  260  may engage the proximal end  50  of the injector body  20  to define a pause location of the folded or partially folded IOL. The nozzle  120  may include a demarcation  1900  that provides a visual indication of the pause position. For example, in the example shown in  FIG. 19 , the demarcation  1900  is a narrow ridge or line that encircles all or a portion of the distal end  60 . In some instances, the demarcation  1900  may be disposed between the tapered portion  62  and the insertion depth guard  140 . At least a portion of the injector body  20  may be formed form a transparent or semi-transparent material that permits a user to see an IOL within the injector body  20 . Particularly, the distal end  60  of the injector body  20  may be formed from a transparent material to permit observation of the IOL as it is moved therethrough by the plunger  30 . 
         [0088]      FIG. 20  shows a view of the distal end  60  of the IOL injector  10  with IOL  70  located therein at a pause position. As shown in  FIG. 20 , the pause position of the IOL may be defined as a location where the distal edge  462  of optic  460  of the IOL  70  substantially aligns with the demarcation  1900 . A haptic  450  or a portion thereof may extend beyond the demarcation  1900 . Again, the pause position may also correspond to the initial engagement of the distal end  265  of the biasing element  260  with the proximal end  50  of the injector body  20 . Therefore, the pause location may be jointly indicated by positioning of the IOL, or part thereof, relative to the demarcation  1900  and the initial contact between the distal end  265  of the biasing element  260 . 
         [0089]    In other instances, a location of the IOL relative to the distal opening  12  of the nozzle  120  when the distal end  256  of the biasing element  260  contacts the proximal end  50  of the injector body  20  may vary. In some instances, the IOL may be partially ejected from the distal opening  125  when the distal end  265  of the biasing element  260  contacts the proximal end  50  of the injector body  20 . For example, in some instances, approximately half of the IOL may be ejected from the distal opening  125  when the distal end  256  of the biasing element  260  contacts the proximal end  50  of the injector body  20 . In other instances, the IOL may be contained wholly within the IOL injector when the distal end  256  of the biasing element  260  contacts the proximal end  50  of the injector body  20 . 
         [0090]      FIG. 21  shows a cross sectional view of the opening  170  formed at the interface  172 . In some instances, the opening  170  may define a “T” shape. The plunger tip  220  is shown disposed at the opening  170  with the flexible wall portion  162  contacting a surface  214  the plunger rod  210 . In some instances, the cross section of the plunger rod  210  increases towards the proximal end of the plunger rod  210 . Thus, as the plunger rod  210  is advanced through the opening  170 , the plunger rod  210  fills the opening as a result of the increasing cross section. Portions  173  and  175  of the opening  170  are filled by flanges  213 ,  215  (shown in  FIG. 11 ). 
         [0091]    As the opening  170  is filled by the increasing cross section of the plunger rod  210  as the plunger rod  210  is advanced distally through the injector body  20 , the flexible wall portion  162  is flexed in the direction of arrow  471  to permit passage of the plunger rod  210 , as shown in  FIG. 22 . Further, as a result of the angled portion  212  of the plunger rod  210 , the contoured ramp  180 , and the folding of IOL  70  as it is advanced through the IOL injector  10 , the plunger tip  220  is made to follow a defined path through the compartment  80 , the distal end  60 , and nozzle  120  uninfluenced by the flexible wall portion  162 . 
         [0092]      FIG. 22  shows the flexible wall portion  162  being flexed in the direction of  471  as the plunger rod  210  continues to advance distally through the IOL injector  10 . Further,  FIG. 22  also shows the plunger tip  220  engaged with IOL  70  such that trailing haptic  450  is received into the first groove  500  at a location offset from the second groove  510 , and the proximal edge of the optic  460  is received into the second groove  510 . 
         [0093]    As the IOL  70  is advanced through the passage  64  of the distal end  60 , the IOL  70  is folded into a reduced size to permit passage of the IOL  70  through the nozzle  120  and into the eye. During folding of the IOL  70 , a resistive force on the plunger  30  is increased. Once the IOL  70  is fully folded  70 , the resistive force on the plunger  30  generally reduces. 
         [0094]    A wound may be formed in the eye. The wound may be sized to accommodate the nozzle  120  of the IOL injector  10 . The nozzle  120  may be inserted into the wound. The nozzle  120  may be advanced through the wound until the flanged surface  150  of the insertion depth guard  140  abuts the exterior surface of the eye. Contact between the insertion depth guard  140  and the exterior surface of the eye limits the depth to which the nozzle  120  may be inserted into the eye, preventing unnecessary stress on the edges of the wound as well as preventing enlargement of the wound due to over insertion of the IOL injector  10 . Consequently, the insertion depth guard  140  operates to reduce additional trauma to the eye and enlargement of the wound. 
         [0095]    With the nozzle properly positioned within the eye through the wound, the user may complete delivery of the folded IOL into the eye. Referring again to  FIG. 15 , as advancement of the plunger  30  continues, the biasing element  260  is compressed (indicated by the dotted outline of biasing element  260 ). Compression of biasing element  260  increases a resistive force to advancement of the plunger  30 , also referred to as plunging force. This additional resistance to advancement of the plunger  30  diminishes changes to the plunging force associated with the folding of the IOL prior to insertion into the eye. Further, in some instances, the biasing element  260  may be made to contact the injector body  120  when, or proximate to when, the IOL  70  has fully folded so that the a reduction in resistive force that may result from the IOL  70  being fully folded may be offset by the compression of the biasing element  260 . This increase in resistive force provided by compression of the biasing element  260 , particularly in light of a reduction that may result due to the IOL  70  being fully folded, provides improved tactile feedback to a user, such as a medical profession, during delivery of the IOL  70  into an eye. This improved tactical feedback provides the user with improved control during delivery of the IOL  70 , which may prevent rapid expulsion of the IOL  70  into the eye. 
         [0096]    As a result, the user is able to provide a smooth application of force without experiencing any sudden or rapid changes in advancement of the plunger  30 . Such sudden or rapid changes may result in the IOL being rapidly expelled from an injector. Rapid expulsion of an IOL into an eye may cause damage, such as perforation of the capsular bag. Such damage may increase the time required to compete the surgical procedure and may increase the harm caused immediately and post operatively to the patient. Upon insertion of the IOL into the eye, the IOL injector  10  may be withdrawn from the eye. 
         [0097]      FIGS. 23-26  show example advancement stops operable to prevent actuation of biasing element  260 . For example, in some instances, the example advancement stops are operable to prevent compression of the biasing element  260  and prevent advancement of the plunger  30  through the injector body  20  beyond a selected amount. Referring to  FIGS. 23 and 24 , an advancement stop  2300  is shown coupled to the body portion  200  of the plunger  30  between the flange  240  and the collar  261  of biasing element  260 . The advancement stop  2300  may be moved into engagement with the plunger  30  laterally in the direction of arrow  2310 . Similarly, the advancement stop  220  may be removed from the plunger  30  laterally displacing the advancement stop  2300  in the direction of arrow  2320 . The advancement stop  2300  may be retained on the plunger  30  such as by a frictional engagement and/or a detent between one or more portions of the plunger  30  and the advancement stop  2300 . A user may manipulate the advancement stop  2300  via a tab  2330  formed thereon. The advancement stop  2300  may be formed from a rigid material, such as a polymer, composite material, metal, or any other suitable material. 
         [0098]    Inclusion of the advancement stop  2300  onto the plunger  30  prevents actuation of the biasing element  260  and further advancement of the plunger  30  through the injector body  20  when the distal end  265  of the biasing element  260  contacts the proximal end  50  of the injector body  20 . Any force acting on the distal end  265  of the biasing element  260  is transmitted from the collar  261  through the advancement stop  2300  and into the flange  240 . In some instances, inclusion of the advancement stop  2300  may be useful to prevent sudden ejection of an IOL from IOL injector  10  due, for example, to excessive forces applied to the IOL injector  10  by the user. In other instances, the advancement stop  2300  may be included in order to ensure that advance of the IOL ceases upon reaching a selected location within the IOL injector  10 . For example, the advancement stop  2300  may prevent further advancement of the IOL once the IOL has reached the pause position. However, an advancement stop, such as the advancement stops described herein, need not be included or otherwise utilized with the IOL injector  10 . 
         [0099]      FIGS. 25-26  illustrate another example implementation of an advancement stop. Example advancement stop  2500  is shown coupled to the plunger  30 . The advancement stop  2500  includes a central member  2510  with arc-shaped wings  2520  extending therefrom. The central member  2510  has an arcuate cross-section that is received onto the body portion  200  of the plunger  30 . The arc shape of the wings  2520  may conform or substantially conform to the shape of the biasing element  260 . The advancement stop  2500  may be retained on the plunger  30  such as by a frictional engagement and/or a detent between one or more portions of the plunger, e.g., biasing element  260  and/or body portion  200 , to name a few examples, and the advancement stop  2500 , e.g., surfaces of the advancement stop  2500  abutting the biasing element  260 , the collar  261 , and/or flange  240 , to name a few examples. The advancement stop  2500  may be formed from a rigid material, such as a polymer, composite material, metal, or any other suitable material. 
         [0100]    Advancement stop  2500  may operate similarly to the advancement stop  2300 . When coupled to the plunger  30 , the advancement stop  2500  limits an amount the plunger  30  may be displaced within the injector body  20 . In some instances, when the plunger  30  has been displaced within the injector body  20  by the selected amount, a distal end of the central member  2510  contacts the proximal end  50  of the injector body  20 . The central member  2510  transmits any force to the flange  240 , thereby preventing actuation of the biasing element  260 . In other instances, the collar  261  may contact the proximal end  50  of the injector body  20 . However, the close engagement between the biasing element  260  and the conforming wings  2520  prevents outward flexure of the biasing element  260 , thereby preventing actuation of the biasing element  260 . 
         [0101]    Although the disclosure provides numerous examples, the scope of the present disclosure is not so limited. Rather, a wide range of modification, change, and substitution is contemplated in the foregoing disclosure. It is understood that such variations may be made to the foregoing without departing from the scope of the present disclosure.