# US 11,433,185 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 11,433,185 B2 - Document ID: US11433185B2 - Status: Granted - Kind: B2 - Application number: 16/580,075 - Filed: 2019-09-24 - Published: 2020-03-26 - Granted: 2022-09-06 - Earliest claimed: 2018-09-24 - Assignees: Norton Healthcare Limited - Applicants: Norton Healthcare Limited - Inventors: Christopher John Clarke; Joseph Peter Corrigan - Web page: https://patentgrep.com/patent/US11433185B2 ## CPC - A61M 5/31501: {Means for blocking or restricting the movement of the rod or piston (A61M5/5013 takes precedence)} - A61M 5/31511: {Piston or piston-rod constructions, e.g. connection of piston with piston-rod (A61M5/5066 takes precedence)} - A61M 5/178: Syringes - A61M 5/28: Syringe ampoules or carpules, i.e. ampoules or carpules provided with a needle - A61M 5/31505: {Integral with the syringe barrel, i.e. connected to the barrel so as to make up a single complete piece or unit} - A61M 5/31515: {Connection of piston with piston rod} - A61M 5/3158: {the component being manually operated or triggered by an axially moving actuator operated by user, e.g. an axially movable injection button} - A61M 5/3202: {Devices for protection of the needle before use, e.g. caps (A61M5/50 takes precedence; protectors for sharps A61B50/3001)} - A61M 5/5013: {Means for blocking the piston or the fluid passageway to prevent illegal refilling of a syringe} - A61M 5/5066: {Means for preventing re-use by disconnection of piston and piston-rod} - A61M 5/3157: {Means providing feedback signals when administration is completed (A61M5/20 takes precedence)} - A61M 5/3205: {Apparatus for removing or disposing of used needles or syringes, e.g. containers; Means for protection against accidental injuries from used needles (for sharps A61B50/362; disintegrating apparatus in general B02C, e.g. B02C19/0075, B23H9/001; disposal of medical waste in general B09B3/00; receptacles for refuse disposal in general B65F1/00)} - A61M 2005/5033: {by use of an intermediate blocking member positioned between the syringe barrel and the piston rod to prevent retraction of the latter, e.g. toothed clip placed on the piston rod} - A61M 2005/5073: {by breaking or rupturing the connection parts} - A61M 2205/3317: Electromagnetic, inductive or dielectric measuring means - A61M 2205/332: Force measuring means - A61M 2205/3576: with non implanted data transmission devices, e.g. using external transmitter or receiver - A61M 2205/581: by audible feedback - A61M 2205/582: by tactile feedback - A61M 2205/583: by visual feedback - A61M 2205/587: Lighting arrangements - 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 An injection device including a barrel having a medicament reservoir therein capable of fluid communication with a needle assembly at a distal end thereof and sealed at a proximal end thereof with a stopper. The injection device further includes a plunger rod having a distal rod end which is couplable with said stopper, wherein, when the plunger rod is coupled to the stopper, forward axial movement of the plunger rod causes forward axial movement of the stopper coupled thereto into the medicament reservoir in order to expel medicament through the needle assembly. Further, the plunger rod can be decoupled from the stopper by applying a rearward axial force on the plunger rod, said rearward axial decoupling force being less than a rearward axial force required to move the stopper rearwardly with respect to the barrel. ## Claims ### Claim 1 An injection device, comprising: a barrel having a medicament reservoir therein capable of fluid communication with a needle assembly at a distal end thereof and sealed at a proximal end thereof with a stopper; and a plunger rod having a distal rod end which is couplable with said stopper, wherein, when the plunger rod is coupled to the stopper, forward axial movement of the plunger rod causes forward axial movement of the stopper coupled thereto into the medicament reservoir in order to expel medicament through the needle assembly, and the plunger rod can be decoupled from the stopper by applying a rearward axial force on the plunger rod, said rearward axial decoupling force being less than a rearward axial force required to move the stopper rearwardly with respect to the barrel, and wherein said distal rod end is coupled with a proximally-facing screw-threaded recess in the stopper. ### Claim 2 (depends on 1) The injection device of claim 1, wherein said distal rod end comprises a spherical end portion engageable with said screw-threaded recess in the stopper. ### Claim 3 (depends on 1) The injection device of claim 1, wherein said distal rod end comprises a ribbed portion having one or more radially extending ribs engageable with said screw-threaded recess in the stopper. ### Claim 4 (depends on 3) The injection device of claim 3, wherein the coupling between said distal rod end and said screw-threaded recess in the stopper is a snap-fit. ### Claim 5 (depends on 3) The injection device of claim 3, wherein the coupling between said distal rod end and said screw-threaded recess in the stopper is a friction-fit. ### Claim 6 (depends on 5) The injection device of claim 5, wherein said rearward axial decoupling force is less than 10N. ### Claim 7 (depends on 6) The injection device of claim 6, wherein when the plunger rod is coupled to the stopper, said distal rod end remains coupled to said stopper when the injection device is held in a plunger-down orientation. ### Claim 8 (depends on 1) The injection device of claim 1, wherein said distal rod end is couplable with said stopper by abutment therewith. ### Claim 9 (depends on 8) The injection device of claim 8, wherein said distal rod end includes a distally-facing stopper-engaging surface to facilitate said abutment with the stopper. ### Claim 10 (depends on 9) The injection device of claim 9, wherein said plunger rod includes a barrel-engaging element which extends radially from said plunger rod to resiliently engage an internal surface of said barrel. ### Claim 11 (depends on 10) The injection device of claim 10, wherein said barrel-engaging element includes one or more airflow passages to permit airflow around the barrel-engaging element. ### Claim 12 (depends on 11) The injection device of claim 11, wherein the barrel-engaging element comprises an annular ratchet element, and a forward axial force required to push the plunger rod into the barrel is less than a rearward axial force required to pull the plunger rod out of the barrel. ### Claim 13 (depends on 12) The injection device of claim 12, wherein the barrel-engaging element comprises a plurality of said annular ratchet elements arranged axially along said plunger rod. ### Claim 14 (depends on 1) The injection device of claim 1, wherein the distal rod end is couplable with said stopper via a magnetic interface therebetween. ### Claim 15 (depends on 14) The injection device of claim 14, wherein the magnetic interface comprises a magnet at the distal rod end and a ferromagnetic material insert on said stopper. ### Claim 16 (depends on 15) The injection device of claim 15, wherein said ferromagnetic material insert is externally threaded and configured to be engaged with the the proximally-facing screw-threaded recess in the stopper. ### Claim 17 (depends on 14) The injection device of claim 14, wherein the magnetic interface comprises a magnet on said stopper and a ferromagnetic material insert on said distal rod end. ### Claim 18 (depends on 17) The injection device of claim 17, further comprising electrically conductive elements in each of said distal rod end and said stopper which, when the distal rod end is coupled with said stopper, complete an electrical circuit. ### Claim 19 (depends on 18) The injection device of claim 18, wherein said electrically conductive elements comprise said magnetic interface. ### Claim 20 (depends on 18) The injection device of claim 18, wherein said electrical circuit is used to power on the injection device when the distal rod end is coupled with said stopper. ### Claim 21 (depends on 20) The injection device of claim 20, wherein said electrical circuit is used to provide the user with visual, audible or tactile feedback as to the readiness of the injection device for use. ### Claim 22 (depends on 21) The injection device of claim 21, wherein the plunger rod comprises a proximal head and wherein the proximal head comprises a 360° LED visible to the user, in use, to provide said visual feedback. ### Claim 23 (depends on 22) The injection device of claim 22, wherein the plunger rod is reusable. ### Claim 24 (depends on 23) The injection device of claim 23, wherein the medicament reservoir is a standard prefilled cartridge and wherein said stopper is the stopper of said standard prefilled cartridge. ### Claim 25 (depends on 24) The injection device of claim 24, further comprising injection monitoring circuitry comprising: an input to receive force measurement data from a force sensor, the force measurement data comprising a plurality of timestamped force measurements of force applied by a user to the injection device when an injection is administered to an injection site; and processing circuitry configured to determine from the force measurement data when an end of injection has been reached, the end of injection corresponding to the plunger rod having reached an end position in a distal portion of the barrel of the syringe during administration of the injection by the user. ### Claim 26 (depends on 25) The injection device of claim 25, wherein at least a portion of the injection monitoring circuitry is provided in a proximal head of the plunger rod.