Claims for Patent: 7,998,108

Summary for Patent: 7,998,108

Title:	Injector apparatus and method of use
Abstract:	Disclosed herein is an injector device including an inserter element, a head element, an implant and a set of detachable protector elements for secured device handling. The device comprises a stop that controls the penetration depth of the device during injection. The device may comprise a removable catch that prevents the implant from exiting the device due to the advancement of its inserter element. The device may comprise a disengageable block that prevents the implant from exiting the device from its head element. The device may be configured for intraocular drug delivery.
Inventor(s):	Nazzaro; Martin (Quincy, MA), Guo; Hong (Belmont, MA), LeBlanc; Ron (Hopedale, MA), York; Josh (Ipswich, MA)
Assignee:	pSivida US, Inc. (Watertown, MA)
Application Number:	11/900,907
Patent Claims:	1. An injector device comprising: a syringe barrel defining a central axial cavity, and having a distal end and a proximal end; a cannula needle having a distal end and a proximal end coaxially coupled to the distal end of the syringe barrel, and defining a central axial cavity in communication with the central axial cavity of the syringe barrel; a plunger having a distal end and a proximal end, disposed in the central axial cavity of the syringe barrel, and extending beyond the proximal end of the syringe barrel when fully depressed; a pusher rod coupled to the distal end of the plunger and adapted to enter the central axial cavity of the cannula needle when the plunger is depressed into the syringe barrel; a stop disposed at the proximal end of the cannula needle, coupled to the distal end of the syringe barrel, and having a portion that extends beyond a cross section of the needle; a disengageable catch coupled to a portion of the plunger and that blocks the plunger from entering the syringe barrel beyond a pre-determined point; an implant disposed in the central axial cavity of the cannula needle between the pusher rod and the distal end of the needle; and a disengageable block that obstructs the implant from exiting the distal end of the cannula needle the block having a first end that penetrates the distal end of the cannula needle and a second end secured to an outside portion of the injector device. 2. The injector according to claim 1, wherein the stop includes a tubular collar and the tubular collar and the cannula needle are coaxially positioned, and a positive cross-sectional area difference between the tubular collar and the needle prevents penetration of the needle into a tissue beyond a pre-determined depth. 3. The injector according to claim 1, wherein the catch is disposed around a portion of the plunger between the proximal end of the syringe barrel and an end-piece at the proximal end of the plunger and interaction among the catch, the proximal end of the syringe barrel, and the plunger's end-piece blocks the plunger from further entering the syringe barrel when the proximal end of the syringe barrel and the plunger's end-piece contact the catch. 4. The injector according to claim 3, wherein an effective catch distance is defined as a difference between a length of the plunger that extends beyond the proximal end of the syringe barrel after further plunger-depression movement is restrained by the catch and a length of the plunger that extends beyond the proximal end of the syringe barrel in a fully depressed position in the absence of the catch. 5. The injector according to claim 4, wherein the catch retrains the plunger at a position such that, at minimum, the effective catch distance is at least as long as a longitudinal length of the implant. 6. The injector according to claim 1, wherein the block is a wire having a hook shape, and a first end of the wire penetrates the distal end of the cannula needle and a second end of the wire is secured to a portion of the injector device. 7. The injector according to claim 1, wherein the block is a wire having a hook shape, and a first end of the wire penetrates the distal end of the cannula needle and a second end of the wire is secured by means of a tubular ring disposed around a periphery of a portion of the injector device. 8. A method of assembling an injector device comprising: providing a syringe barrel defining a central axial cavity, and having a distal end and a proximal end; providing a plunger having a distal end and a proximal end, and adapted to enter the central axial cavity of the syringe barrel; providing a cannula needle defining a central axial cavity, and having a distal end and a proximal end; disposing a pusher rod coupled to the plunger in the central axial cavity of the syringe barrel, having a portion of the pusher rod extends beyond the distal end of the syringe barrel, and having a portion of the plunger extends beyond the proximal end of the syringe barrel; coupling a removable catch to the injector device; fitting the pusher rod into the central axial cavity of the cannula needle and operatively coupling the cannula needle to the distal end of the syringe barrel; placing an implant within the central axial cavity of the cannula needle between the pusher rod and the distal end of the needle; and coupling a disengageable block to the injector device. 9. The method according to claim 8, wherein coupling the removable catch comprises disposing the catch to a portion of the plunger between the proximal end of the syringe barrel and an end-piece at the proximal end of the plunger and the removable catch is adapted to interact with the proximal end of the syringe barrel and the plunger's end-piece to block the plunger from further entering the syringe barrel when the proximal end of the syringe barrel and the plunger's end-piece contact the catch. 10. The method according to claim 9, wherein coupling the removable catch creates a catch distance defined as a difference between a length of the plunger that extends beyond the proximal end of the syringe barrel after further plunger-depression movement is restrained by the catch and a length of the plunger that extends beyond the proximal end of the syringe barrel in a fully depressed position in the absence of the catch. 11. The method according to claim 10, wherein the removable catch is adapted to retrain the plunger at a position such that, at minimum, the effective catch distance is at least as long as a longitudinal length of the implant. 12. The method according to claim 8, wherein the disengageable block is a hook-shaped block wire with a first end disposed in the distal end of the cannula needle and a second end of the block wire is coupled to a portion of the injector device. 13. The method according to claim 8, wherein the disengageable block is a hook-shaped block wire with a first end disposed in the distal end of the cannula needle and a second end of the block wire is secured by means of a tubular ring around a periphery of a portion of the device. 14. A method of injecting an implant using an injector device, comprising: providing an injector device of claim 1; removing the block if it is present; removing the catch if it is present; inserting the cannula needle into a tissue to a depth where surface of the tissue contacts the stop; and depressing the plunger into the syringe barrel to eject the implant via the distal end of the cannula needle into the tissue. 15. The method according to claim 14, wherein the tissue is an eye. 16. The method according to claim 15, wherein the cannula needle is a 25-gauge needle and the cannula needle has a beveled tip adapted to penetrate a sclera of an eye. 17. The method according to claim 16, wherein the stop of the injector device is a tubular collar. 18. The method according to claim 17, wherein the tubular collar and the cannula needle are coaxially positioned, and a positive cross-sectional area difference between the tubular collar and the needle prevents penetration of the needle into the eye beyond a pre-determined depth of about 0.25 to 0.45 centimeters. 19. The method according to 18, wherein the catch is disposed around a portion of the plunger between the proximal end of the syringe barrel and an end-piece at the proximal end of the plunger. 20. The method according to 19, wherein the interaction among the catch, the proximal end of the syringe barrel, and the plunger's end-piece blocks the plunger from further entering the syringe barrel when the proximal end of the syringe barrel and the plunger's end-piece contact the catch. 21. The method according to claim 20, wherein an effective catch distance, defined as a difference between a length of the plunger that extends beyond the proximal end of the syringe barrel after further plunger-depression movement is restrained by the catch and a length of the plunger that extends beyond the proximal end of the syringe barrel in a fully depressed position in the absence of the catch, is about 0.6 centimeters. 22. The method according to claim 21, wherein a longitudinal length of the implant is between 0.1 to 0.6 centimeters. 23. The method according to claim 22, wherein the disengageable block is a hook-shaped wire and a first end of the wire penetrates the distal end of the cannula needle and a second end of the wire is secured to a portion of the intraocular injector device. 24. The method according to claim 22, wherein the disengageable block is a hook-shaped wire and a first end of the wire penetrates the distal end of the cannula needle and a second end of the wire is secured by means of a tubular ring disposed around a periphery of a portion of the intraocular injector device.