Abstract:
The present disclosure provides a new and improved intravitreal injection device, which is capable of locating the injection site with precision and reproducibility, ensuring the smooth delivery of medications or other treatments, and reducing potential need contaminations. In various embodiments, the device comprises a head unit and a hollow stem extending orthogonally from a bottom of the head unit. The device additionally includes a locating foot slidingly disposed on a distal end of the stem and a biasing device structured to bias the locating foot toward an extended position.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 61/465,882, filed on Mar. 25, 2011. The disclosure of the above application is incorporated herein by reference in its entirety. 
     
    
     FIELD 
       [0002]    The present disclosure relates to a medical device for intravitreal injections, more specifically, to an intravitreal injection device that provides precise and reproducible delivery of medications or other treatments to a target injection site. 
       BACKGROUND 
       [0003]    Intravitreal injections are frequently used for primarily three purposes: the most common use involves injecting medications, or other treatments, to treat age-related macular degeneration; the second use involves injecting an expansible gas for management of retinal detachment; and the least common use involves injection of antibiotics in case of infection of the inner contents of the eye. Currently the success or failure of an intravitreal injection relies on the experience of the physician performing the procedure. The injection needle has to be placed at a precise location and directed at a correct angle to avoid injury to the internal structures of the eye, which creates a significant learning curve to a novice while performing the procedure. 
       SUMMARY 
       [0004]    The present disclosure provides an intravitreal injection device that is structured and operable to locate an injection site with precision and reproducibility and to reduce potential needle contaminations. Accordingly, the present intravitreal injection device ensures the smooth, reliable and accurate delivery of intravitreal medications, or other treatments, and significantly reduces the inherent risks commonly associated with known intravitreal injection methods. In various embodiments, the device comprises a head unit and a hollow stem extending orthogonally from a bottom of the head unit. The device additionally includes a locating foot slidingly disposed on a distal end of the stem and a biasing device structured to bias the locating foot toward an extended position. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0005]    The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present teachings in any way. 
           [0006]      FIG. 1(   a ) is a schematic of the device for accurately locating an intravitreal injection, in accordance with various embodiments of the present disclosure. 
           [0007]      FIG. 1(   b ) is a bottom view of the device shown in  FIG. 1(   a ), in accordance with various embodiments of the present disclosure. 
           [0008]      FIG. 1(   c ) is a schematic of the device shown in  FIG. 1(   a ) having a locating foot of the device in a depressed position, in accordance with various embodiments of the present disclosure. 
           [0009]      FIG. 1(   d ) is a top view of the device shown in  FIG. 1(   a ), in accordance with various embodiments of the present disclosure. 
           [0010]      FIG. 2(   a ) is an isometric top view of the device shown in  FIG. 1(   a ), in accordance with various embodiments of the present disclosure. 
           [0011]      FIG. 2(   b ) is a cross-sectional view of the device shown in  FIG. 1(   a ), in accordance with various embodiments of the present disclosure. 
           [0012]      FIG. 3(   a ) is an isometric view of the device shown in  FIG. 1(   a ) removably connected to a hypodermic needle, in accordance with various embodiments of the present disclosure. 
           [0013]      FIG. 3(   b ) is a side view of the device shown in  FIG. 1(   a ) removably connected to a hypodermic needle that is connected to a syringe, in accordance with various embodiments of the present disclosure. 
       
    
    
       [0014]    Corresponding reference numerals indicate corresponding parts throughout the several views of drawings. 
       DETAILED DESCRIPTION 
       [0015]    The following description is merely exemplary in nature and is in no way intended to limit the present teachings, application, or uses. Throughout this specification, like reference numerals will be used to refer to like elements. 
         [0016]    Referring to  FIGS. 1(   a ) through  3 ( b ), in accordance with various embodiments, the present disclosure provides an injection locating device  10  structured and operable to accurately locate an intravitreal injection. The device  10  includes a head unit  14 , a hollow stem  18  extending orthogonally from a bottom  14 A of the head unit  14 , a locating foot  22  slidingly disposed on a distal end  18 A of the stem  18 , and a biasing device  26  structured to bias the locating foot  22  toward an extended position, shown in  FIG. 1(   a ). Generally, the device  10  is connectable to a hypodermic needle  30 , as shown in  FIGS. 1(   c ),  3 ( a ) and  3 ( b ), or more particularly to a connector cap  30 A of the hypodermic needle  30 , and is structured and operable to accurately locate an injection, to be delivered via a shaft  30 B of the hypodermic needle  30 , i.e., the needle portion of the hypodermic needle  30 , at the pars plana of a human eye and into the mid-vitreous cavity where there are no critical structures. Hence, intravitreal injections delivered using the device  10 , as described further below, will not cause damage to the eye. As used herein, the pars plana will be understood to mean the part of the eye that is approximately 3.5 mm to 5.0 mm from the limbus of the eye. 
         [0017]    The head unit  14  is formed to include a needle retention fixture  34  that is structured and operable to removably retain the hypodermic needle  30  therein. In various embodiments, the needle retention fixture is sized and structured to receive and removably retain the connector cap  30 A of the hypodermic needle  30 , wherein the connector cap  30 A is designed to connect the hypodermic needle  30  to a syringe  38  or other suitable medication or treatment dispensing device. It is envisioned that connector cap  30 A can be any known or unknown hypodermic needle connector cap, such as a well-known Luer-Lok® type connector cap. In various embodiments, the needle retention fixture  34  is a reservoir formed within a center of the head unit  14  having raised ridges  34 A disposed along the wall of the reservoir. The raised ridges  34 A are structured and operable to frictionally engage the hypodermic needle connector cap  30 A, thereby firmly retaining the device  10  on the hypodermic needle  30 . 
         [0018]    It is envisioned that the needle retention fixture  34  can comprise any other structure(s) or device(s) suitably structured and operable to firmly retain the hypodermic needle connector cap  30 A within the head unit  14 . For example, in various implementations, the retention fixture  34  can comprise a reservoir formed within a center of the head unit  14  having one or more annular or spiraled protuberances formed along the wall of the reservoir. Or, alternatively, the retention fixture  34  can comprise a reservoir formed within a center of the head unit  14  having a latching or clasping mechanism disposed on the top surface of the head unit  14 , whereby the latching or clasping mechanism is operable to latch or clasp the hypodermic needle cap  30 A within the reservoir. 
         [0019]    Furthermore, it is envisioned that in other embodiments the needle retention fixture  34  can be structured and operable to be removably retained on the hypodermic needle  30  by frictionally, or otherwise, engaging the shaft  30 B of the hypodermic needle  30 . 
         [0020]    As described above, the stem  18  is hollow and extends orthogonally from the bottom  14 A of the head unit  14 . More particularly, the stem  18  includes a longitudinal lumen  42  (shown in  FIG. 2(   b )) that extends the entire length of the stem  18  and is fluidly connected to the needle retention fixture  34 , i.e., the lumen  42  opens into the needle retention fixture  34 . Therefore, when the connector cap  30 A of the hypodermic needle  30  is retained within the needle retention fixture  34  the shaft  30 B of the hypodermic needle  30  will extend into the lumen  42  and be protected by the stem  18  and locating foot  22  from contamination by the ambient environment or inadvertent contact with the patient&#39;s eyelids, eyelashes, etc. As shown in  FIG. 2(   b ), in various implementations, the stem  18  additionally includes a terminus check  46  disposed or formed at the distal end  18 A of the stem  18 . The terminus check  46  is structured and operable to retain the locating foot  22  on the distal end  18 A, as described further below. 
         [0021]    In various embodiments, the locating foot  22  is structured to include a hollow neck  22 A and a sole plate  22 B disposed or formed at a distal end  23  of the neck  22 A. In various implementations, a bottom surface  24  of the sole plate  22 B has a concave shape that will provide a conforming contact interface with the globe of a human eye when the locating foot  22  is placed in contact with the globe, as described below. Particularly, in various implementations, the concave bottom surface  24  has a radius of curvature that is substantially equivalent to the radius of curvature of the globe of a human eye, for example 11.0 mm to 13.0, e.g., 12.0 mm. The neck  22 A includes a longitudinal bore  50  (shown in  FIG. 2(   b )) that extends the length of the neck  22 A. The bore  50  is sized to receive the stem  18  such that the locating foot  22  can longitudinally slide along the distal portion  18 A of the stem  18 . Additionally, the locating foot  22  includes an annular stop  54  that is integrally formed or disposed within the bore  50 . The annular stop  54  is structured and operable to engage the terminus check  46  of the stem  18  to prevent the locating foot  22  from sliding off the distal end  18 A of the stem  18 . More particularly, the biasing device  26  is structured and operable to exert a force on the locating foot  22  that will force the locating foot  22  in the X +  direction, away from the head unit  14 . Therefore, when the device  10  is in a static state, i.e., not having an opposing force applied to the device  10  in the X −  direction, the locating foot  22  will be forced to an ‘Extended’ position by the biasing device  26 , as shown in  FIGS. 1(   a ),  2 ( a  and  b ) and  3 ( a  and  b ). When in the ‘Extended’ position, the annular stop  54  of the locating foot  22  is in contact with terminus check  46  of the stem  18  and the locating foot  22  is prevented from being pushed off the stem  18  by the biasing device  26 . 
         [0022]    As described above, when the hypodermic needle  30  is retained within the needle retention fixture  34  the shaft  30 B of the hypodermic needle  30  will extend into the stem lumen  42 . Furthermore, the stem  18  is structured to have a particular length L (shown in  FIG. 2(   b )) such that a desired portion of the hypodermic needle shaft  30 B, e.g., 5/16 to 13/16 of an inch or 7.9 mm to 20.6 mm, will extend beyond the distal end  18 A of the stem  18  and protrude into the bore  50  of the locating foot neck  22 A. Additionally, the locating foot neck  22 A is structured to have a particular length M (shown in  FIG. 2(   b )) such that the portion of the hypodermic needle shaft  30 B that extends beyond the stem distal end  18 A is entirely disposed within the bore  50  and protected from contamination by the locating foot  22  when the locating foot  22  is in the ‘Extended’ position. 
         [0023]    Referring particularly to  FIGS. 1(   b ) and  2 ( b ), the locating foot sole plate  22 B includes at least one curved edge  58 . As exemplarily illustrated in  FIG. 1(   b ), in various embodiments, the sole plate  22 B can have opposing curved edges  58 . Each curved edge  58  has a radius of curvature substantially equal to the radius of curvature of the limbus of a human eye, for example 5.0-6.5 mm, e.g., 5.5 mm. The locating foot sole plate  22 B additionally includes an egress aperture  62  that extends through a center of the sole plate  22 B and is fluidly connected to the bore  50  within the neck  22 A. The egress aperture  62  is sized to allow the shaft  30 B of a hypodermic needle  30  to pass therethrough, as shown in  FIG. 1(   c ). 
         [0024]    Importantly, the egress aperture  62  is located at a specific target zone distance D from a center point of each curved edge  58 , e.g., 3.5 mm to 4.0 mm from the center point of the curved edge  58 . Therefore, an operator, e.g., a physician or ophthalmologist, can place the bottom surface  24  of sole plate  22 B in contact with the globe of a human eye having the, or one of the, curved edge(s)  58  aligned with the limbus such that the egress aperture  62  is accurately and reproducibly located the target zone distance D from the limbus, e.g., 3.5 mm to 4.0 mm, where medication, or other treatment, can be delivered into the mid-vitreous cavity, via the hypodermic needle  30 , without causing damage to the eye. It is important to understand that the target zone distance D is specifically calculated/determined to be a distance equal to a radial distance from the limbus, i.e., a substantially orthogonal distance from the limbus along the surface of the globe of the eye, i.e., the conjunctiva and sclera, that is known to identify a specific location on the globe where an intravitreal injection can occur in the mid-vitreous cavity without penetrating or damaging any critical structures of the eye, and hence, without damaging the eye. 
         [0025]    Referring now to  FIGS. 1(   a ) and  1 ( b ), the biasing device  26  is structured to have a specific biasing force that will maintain the locating foot  22  in the ‘Extended’ position when the device  10  is in a static state, but can be easily overcome by applying a light force in the X −  direction to the device  10 . More specifically, the biasing force of the biasing device  26  is calibrated to retain the locating foot  22  in the ‘Extended’ position when the sole plate  22 B is not in contact with the human eye, but can be easily overcome by an opposing force in the X −  direction applied by the operator, e.g., physician or ophthalmologist, to the head unit  14  or the syringe  38  (or other medication or treatment dispensing device having the hypodermic needle  30  connected thereto) when the sole plate  22 B is aligned with the limbus and placed in contact with the globe of the eye. 
         [0026]    Particularly, when the injection locating device  10  is engaged with the hypodermic needle  30 , as described above, (the hypodermic needle  30  being connected to a syringe  38  or other medication or treatment dispensing device) and the operator, aligns an edge  58  with the limbus and places the sole plate  22 B in contact with the eye, the operator can apply a force to the syringe  38  (or other medication or treatment dispensing device) and/or head unit  14  downward toward the eye. This downward force will overcome the biasing force of the biasing device  26  in the X +  direction and cause the neck  22 A of the locating foot  22  to slide along the distal end  18 A of the stem  18  toward the head unit  14  to a depressed or ‘Injection’ position, shown in  FIG. 1(   c ), wherein the distal end  18 A of the stem  18  abuts and contacts an upper surface  25  of the sole plate  22 B within the bore  50  of locating foot neck  22 A. The biasing force of the biasing device  26  is calibrated such that the force applied by the operator to overcome the biasing force will not damage the anatomy of the eye. 
         [0027]    Consequently, this downward force will cause the hypodermic needle shaft  30 B to protrude through the egress aperture  62  in the sole plate  22 B and penetrate the eye at the target zone distance D from the limbus such that the needle shaft  30 B will enter the mid-vitreous cavity of the eye. Thereafter, the operator can inject a medication or treatment disposed in the syringe  38  (or other medication or treatment dispensing device) into the eye via the appropriate operation of the syringe  38  (or other medication or treatment dispensing device). 
         [0028]    As described above, the neck  22 A of the locating foot  22  is structured to have a particular length M. Importantly, the length M is calibrated such that when the locating foot  22  is depressed to the ‘Injection’ position, as described above, only a desired portion of the hypodermic needle shaft  30 B, e.g., ¼ to ¾ of an inch or 6.3 mm to 19.0 mm, will extend beyond the bottom surface  24  of the sole plate  22 B. More specifically, the length M of the neck  22 A is calibrated to gauge the depth of penetration of the needle shaft  30 B into the mid-vitreous cavity of the eye, e.g., ¼ to ¾ of an inch or 6.3 mm to 19.0 mm. 
         [0029]    The biasing device  26  can be any device, structure or mechanism structured to have a specific biasing force in the X +  direction that will maintain the locating foot  22  in the ‘Extended’ position when the device  10  is in a static state, but can be easily overcome by applying a light force in the X −  direction to the device  10 , as described above. For example, in various embodiments, the biasing device  26  can be a light weight coil spring, as shown throughout the figures. Alternatively, the biasing device  26  can be one or more leaf springs, a flexible and resilient sleeve or gasket disposed over the stem  18 , or any other suitable actuator or spring-like device, structure or mechanism. 
         [0030]    Referring particularly to  FIGS. 1(   b ) and  3 ( a ), in various embodiments the locating foot  22  can include a plurality of stabilizing bosses  66  extending from the bottom surface  24  of the sole plate  22 B. The stabilizing bosses are structured and operable to maintain the position of the sole plate  22 B on the globe of the eye once the sole plate  22 B has been positioned and placed on the eye, as described above. Particularly, when the operator applies the downward force to the syringe  38  (or other medication or treatment dispensing device) and/or head unit  14 , the bosses  66  will protrude slightly into the surface of the eye, i.e., the conjunctiva and sclera, thereby stabilizing the locating foot  22 , and assisting in keeping the sole plate  22 B aligned with the limbus and the egress aperture  62  located the target zone distance D from the limbus. 
         [0031]    While the disclosure has been described in connection with specific embodiments thereof, it will be understood that the device is capable of further modifications. This patent application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains and as may be applied to the essential features herein.