# US 11,992,668 B2 · Injection device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,992,668 B2 - Document ID: US11992668B2 - Status: Granted - Kind: B2 - Application number: 16/358,553 - Filed: 2019-03-19 - Published: 2019-07-11 - Granted: 2024-05-28 - Earliest claimed: 2008-12-02 - Assignees: Allergan, Inc. - Applicants: Allergan, Inc. - Inventors: Ahmet Tezel; Kevin McNerney; Christopher S. Mudd; Blake R. Storie; Bastien Mandaroux - Web page: https://patentgrep.com/patent/US11992668B2 ## CPC - A61M 5/347: {rotatable, e.g. bayonet or screw (A61M5/344 takes precedence)} - A61M 5/3293: {characterised by features of the needle hub} - A61M 2210/04: Skin - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} ## Abstract A needle assembly for an injection device is provided to facilitate delivery of a dermal filler. The assembly includes a cannula and a hub. The hub can be coupled to a syringe. The hub includes an inner bore that has a proximal retention section, a stepped section, and a cannula retention section. The stepped section, the proximal retention section, and the cannula retention section are configured to reduce the dead space within the inner bore for preventing detachment of the hub from the syringe during an injection procedure. ## Claims ### Claim 1 A needle assembly for delivering a dermal filler, the assembly comprising: a cannula; and a hub having an inner bore, the inner bore comprising a proximal retention section, a stepped section, and a cannula retention section, the proximal retention section being mateable with a syringe, the stepped section being smaller in diameter than the proximal retention section and being disposed intermediate the proximal retention section and the cannula retention section, the inner bore having a stepped section surface wherealong the inner bore decreases in diameter to a proximal end of a cannula retention surface of the cannula retention section, the inner bore not increasing in diameter from the proximal retention section to a distal end of the cannula retention section, the cannula retention section having a constant diameter, the cannula retention surface being mated against an outer surface of the cannula to secure the cannula within the cannula retention section; wherein the hub comprises an inside surface of the proximal retention section, the inside surface comprising a tapered wall and a step, the step extending normal to a longitudinal axis extending through the needle assembly, the step being configured to be spaced apart from a distal-most surface of a tapered syringe cone of a syringe in a distal direction when the hub and the tapered syringe cone are maximally seated thereby reducing dead space within the proximal retention section for preventing detachment of the hub from the tapered syringe cone during injection of a dermal filler contained in a body of the syringe; wherein the cannula is distal to the step, and wherein the step is positioned a distance from the cannula, and wherein the outer surface of the cannula is mated against the cannula retention surface from the proximal end of the cannula retention surface to a distal end of the hub. ### Claim 2 (depends on 1) The assembly of claim 1, wherein the hub comprises external threads for coupling with a syringe. ### Claim 3 (depends on 1) The assembly of claim 1, wherein the cannula has a gauge of greater than about 25 G. ### Claim 4 (depends on 1) The assembly of claim 1, wherein the cannula has a gauge between 21 G and 32 G. ### Claim 5 (depends on 1) The assembly of claim 1, wherein the cannula retention surface extends normal to the stepped section surface. ### Claim 6 (depends on 1) The assembly of claim 1, wherein the cannula retention surface extends continuously with the stepped section surface. ### Claim 7 (depends on 1) The assembly of claim 1, wherein the stepped section has a constant diameter. ### Claim 8 (depends on 1) The assembly of claim 1, wherein the hub further comprises a luer connector. ### Claim 9 (depends on 2) The assembly of claim 2, wherein the external threads comprise double lead screw threads. ### Claim 10 (depends on 2) The assembly of claim 2, wherein the external threads comprise double lead screw threads. ### Claim 11 (depends on 1) An injection device for facilitating delivery of a dermal filler, the device comprising the needle assembly of claim 1 and a syringe having (i) a body with a piston disposed therein and (ii) an open distal end portion, the hub of the needle assembly engageable with the open distal end portion of the syringe. ### Claim 12 A needle assembly for an injection device for facilitating delivery of a dermal filler, the assembly consisting essentially of: a cannula; and a hub having an inner bore, the inner bore comprising a proximal retention section, a stepped section, and a cannula retention section, the stepped section being smaller in diameter than the proximal retention section and being disposed intermediate the proximal retention section and the cannula retention section, the inner bore having a stepped section surface wherealong the inner bore decreases in diameter to a proximal end of a cannula retention surface of the cannula retention section, the inner bore not increasing in diameter from the proximal retention section to a distal end of the cannula retention section, the cannula retention section having a constant diameter, the cannula retention surface being mated against an outer surface of the cannula to secure the cannula within the cannula retention section; wherein the hub comprises an inside surface of the proximal retention section, the inside surface comprising a tapered wall and a step, the step extending normal to a longitudinal axis extending through the needle assembly, the step being configured to be spaced apart from a distal-most surface of a tapered syringe cone of a syringe in a distal direction when the proximal retention section and a distal end portion of a syringe are coupled thereby reducing dead space within the inner bore for preventing detachment of the hub from the syringe during an injection procedure; wherein the cannula is distal to the step, and wherein the step is positioned a distance from the cannula, and wherein the outer surface of the cannula is mated against the cannula retention surface from the proximal end of the cannula retention surface to a distal end of the hub. ### Claim 13 (depends on 12) The assembly of claim 12, wherein the cannula retention surface extends normal to the stepped section surface. ### Claim 14 (depends on 12) The assembly of claim 12, wherein the cannula retention surface extends continuously with the stepped section surface. ### Claim 15 (depends on 12) The assembly of claim 12, wherein the stepped section has a constant diameter. ### Claim 16 (depends on 12) The assembly of claim 12, wherein the hub further comprises a luer connector.