Needle-less injector

Abstract

A needle-less injector comprises a cartridge ( 3 ) prefilled with liquid (( 9 ), which cartridge contains a free sliding piston ( 32 ) and an injection orifice ( 10 ). A ram ( 22 ) is urged by a pre-loaded spring ( 24 ) for striking the said piston to cause the injections. Adjusting means ( 6 ) can be provided to vary the volume injected. A trigger device ( 26, 30 ) initiates injection only when the optimum contact pressure is reached between the discharge orifice ( 1 ) and epidermis of the subject. The initial loading of the power spring ( 24 ) is sufficient to dispense all of the contents of the medicament cartridge in one dose or multiple sequential doses. Disposable and reusable embodiments are described.

I claim:  
     
         1 . A needle-less injector comprising an actuator and a cartridge filled with a liquid to be injected in a subject, the cartridge having a liquid outlet and a free piston inward of the liquid outlet in contact with the liquid, the liquid outlet comprising an opening in the cartridge, a membrane initially covering the opening, and a perforating member which perforates the membrane to allow the said liquid to pass therethrough, said actuator comprising; 
 (a) a housing having a forward portion adapted to be connected with the cartridges;    (b) an impact member mounted within said housing inward of the forward portion so as to be movable from a first position toward the forward portion to strike the free piston when a cartridge is connected and to continue to move the free piston toward the liquid outlet whereby a dose of the liquid is expelled through the liquid outlet in the cartridge; and    (c) an energy store which, when released, moves said impact member towards the liquid outlet.    
     
     
         2 . An injector according to    claim 1   , wherein said energy store comprises: 
 (i) a spring which exerts a force on said impact member to normally urge said impact member toward the liquid outlet; and    (ii) a latch within said housing which engages said impact member to prevent movement of the impact member toward the forward portion in response to said force exerted by said spring, and being mounted to be movable out of engagement with said impact member to a firing position, in which said latch permits such movement.    
     
     
         3 . An injector as claimed in    claim 2   , wherein the said spring is a compression spring.  
     
     
         4 . An injector as claimed in    claim 2   , wherein the spring is a gas spring provided by a chamber within said housing refilled with pressurized gas which constantly exerts a force on said impact member to normally urge said impact member towards the liquid outlet.  
     
     
         5 . An injector as claimed in    claim 4   , wherein said pressurized gas is air.  
     
     
         6 . An injector as claimed in    claim 2   , further comprising trigger means for operating said latch to thus initiate the injection in response to a predetermined contact force between the liquid outlet of the cartridge and the subject.  
     
     
         7 . An injector as claimed in    claim 6   , wherein said actuator has a user-holdable portion and means for mounting the cartridge so that the user-holding portion is movable relative to the cartridge by the liquid outlet of the cartridge being urged into contact with the subject, and said latch comprises a latch member which is movable to said firing position by the relative movement between the user-holdable portion and the cartridge.  
     
     
         8 . An injector as claimed in    claim 7   , wherein said latch member is resilient.  
     
     
         9 . An injector as claimed in    claim 1   , wherein the energy store is sufficient to expel a single dose of the liquid.  
     
     
         10 . An injector as claimed in    claim 1   , wherein the energy store is sufficient to expel a plurality of successive doses of the liquid.  
     
     
         11 . An injector as claimed in    claim 1   , wherein the cartridge includes a separately held plurality of components which are to be mixed with one another prior to injection and a mixing member for mixing the plurality of components with one another, said impact member further comprising a mixing means being movable toward the liquid outlet for striking the mixing member, whereby the plurality of components are mixed with one another.  
     
     
         12 . An actuator in combination with a cartridge to form a needle-less injector, comprising: 
 (a) said cartridge being refilled with a liquid to be injected in a subject, said cartridge comprising: 
 (i) a liquid outlet and a free piston inward of the liquid outlet in contact with the liquid, the liquid outlet comprising an opening in the cartridge, a membrane initially covering the opening, and a perforating member which perforates the membrane to allow the said liquid to pass therethrough;  
 (ii) a separately held plurality of components which are to be mixed with one another prior to the injection; and  
 (iii) a mixing member for mixing the plurality of components with one another, wherein the plurality of compartments are separated by at least one partition and said cartridge further has a penetrating member so mounted therein as to be movable to a mixing position in which it penetrates the (or each) partition; and  
   (b) said actuator comprising: 
 (i) a housing adapted to be connected with the cartridge;  
 (ii) impact member mounted within said housing inward of the free piston so as to be movable from a first position toward the liquid outlet to strike the free piston and to continue to move the free piston toward the liquid outlet whereby a dose of the liquid is expelled through the liquid outlet in the cartridge, said impact member further comprising a mixing means being movable toward the liquid outlet for striking the mixing member, said mixing means in striking said mixing member being further operable to move the penetrating member to the mixing position whereby the plurality of components are mixed with one another; and  
 (iii) an energy store which, when released, moves said impact member towards the liquid outlet.  
   
     
     
         13 . An actuator according to    claim 12   , wherein the energy store comprises a spring which exerts a force on said impact member when said impact member is in said first position to normally urge said impact member toward the liquid outlet; and a latch within said housing for engaging said impact member toward the liquid outlet in response to said force exerted by said spring, and being movable to a firing position for permitting such movement.  
     
     
         14 . An injector as claimed in    claim 1   , wherein the movement of said impact member expels a fixed dose.  
     
     
         15 . An injector as claimed in    claim 1   , wherein the distance of travel of said impact member after striking the free piston is variable to determine the dose of the liquid expelled through the liquid outlet in the cartridge.  
     
     
         16 . An injector as claimed in    claim 1   , comprising means for retaining said cartridge for engagement with said actuator, said retaining means being constructed to permit removal of said cartridge.  
     
     
         17 . An injector as claimed in    claim 1   , comprising means for retaining said cartridge for engagement with said actuator, said retaining means being constructed to permit the fixed mounting of said cartridge.  
     
     
         18 . An injector as claimed in    claim 1   , wherein said cartridge has a body comprising glass.  
     
     
         19 . An injector as claimed in    claim 18   , wherein said glass is transparent.  
     
     
         20 . An injector as claimed in    claim 18   , wherein said free piston of said cartridge comprises a plastics material.  
     
     
         21 . An injector as claimed in    claim 20   , wherein said plastic material is a polymer or copolymer comprising a fluorinated hydrocarbon.  
     
     
         22 . An injector as claimed in    claim 20   , wherein said plastic material is a polytetrafluoroethylene.  
     
     
         23 . An injector as claimed in    claim 20   , wherein said plastic material is selected from the group consisting of tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer, polychlorotrifluoroethylene, poly (vinylidene fluoride), tetrafluoroethylene-perfluoro (propel vinyl ether) copolymer, and hexafluoroisobutylenevinylidene fluoride copolymer.  
     
     
         24 . A cartridge for use in conjunction with an actuator to form a needle-less injector, said cartridge comprising a body comprising glass and a piston mounted in said body with an interference fit, said piston comprising a material which is substantially non-resilient when subjected to a slowly applied force but is highly resilient when subjected to a rapidly applied force.  
     
     
         25 . (Amended) A cartridge as claimed in    claim 24   , wherein said glass is transparent  
     
     
         26 . (Twice Amended) A cartridge as claimed in    claim 24   , wherein said piston comprises a plastic material.  
     
     
         27 . (Amended) A cartridge as claimed in    claim 26   , wherein said plastic material is a polymer or copolymer comprising a fluorinated hydrocarbon.  
     
     
         28 . (Amended) A cartridge as claimed in    claim 26   , wherein said plastic material is polytetrafluoroethylene.  
     
     
         29 . (Amended) A cartridge as claimed in    claim 26   , wherein said plastic material is selected from the group consisting of tetrafluoroethylenehexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer, polychlorotrifluoroethylene, poly (vinylidene fluoride), tetrafluoroethyleneperfluoro (propel vinyl ether) copolymer, and hexafluoroisobutylene-vinylidene fluoride copolymer.  
     
     
         30 . A cartridge as claimed in    claim 24   , having an outlet orifice sealed by a perforatable membrane.  
     
     
         31 . A cartridge for use in conjunction with an actuator to form a needle-less injector, comprising a body which is of glass and a piston which is slidably mounted in the body and which comprises polytetrafluoroethylene.  
     
     
         32 . A cartridge as claimed in    claim 31   , having an outlet orifice sealed by a perforatable membrane.  
     
     
         33 . A cartridge for use in conjunction with an actuator to form a needle-less injector, said cartridge comprising a body and piston mounted in said body with an interference fit, said body having an outlet orifice sealed by a perforatable membrane.  
     
     
         34 . An actuator for use in conjunction with a cartridge to form a needle-less injector, the cartridge being filled with a liquid to be injected in a subject, the cartridge having a liquid outlet and a free piston inward of the liquid outlet in contact with the liquid, said actuator comprising: 
 (a) a housing having a forward portion adapted to be connected with the cartridge;    (b) an impact member mounted within said housing inward of the forward portion so as to be movable from a first position toward the forward portion to strike the free piston when a cartridge is connected and to continue to move the free piston toward the liquid outlet whereby a dose of the liquid is expelled through the liquid outlet in the cartridge;    (c) a spring which exerts a force on said impact member to normally urge said impact member toward the liquid outlet;    (d) a latch within said housing which engages said impact member to prevent movement of the impact member toward the forward portion in response to said force exerted by said spring, and being mounted to be movable out of engagement with said impact member to a firing position, in which said latch permits such movement; and    (e) means for varying the said dose of liquid.    
     
     
         35 . An actuator as claimed in    claim 34    which comprises a distal portion for carrying the cartridge and a proximal portion of carrying the impact member, the said means for varying the dose comprising means for varying the position of the distal portion with respect to the proximal portion in the said first direction.  
     
     
         36 . An actuator as claimed in    claim 35    wherein said position varying means comprises interengaging screw threads on the distal and proximal portions.  
     
     
         37 . An actuator as claimed in    claim 34    wherein the said spring is a compression spring.  
     
     
         38 . An actuator as claimed in    claim 34    wherein the spring is a gas spring provided by a chamber within said housing refilled with pressurized gas which constantly exerts a force on said impact member to normally urge said impact member towards the liquid outlet.  
     
     
         39 . An actuator as claimed in    claim 38    wherein said pressurized gas is air.  
     
     
         40 . An actuator as claimed in    claim 34    further comprising trigger means for operating said latch to thus initiate the injection in response to a predetermined contact force between the liquid outlet of the cartridge and the subject.  
     
     
         41 . An actuator as claimed in    claim 40    wherein said actuator has a user-holdable portion and means for mounting the cartridge so that the user-holdable portion is movable relative to the cartridge by the liquid outlet of the cartridge being urged into contact with the subject, and said latch comprises a latch member which is movable to said firing position by the relative movement between the user-holdable portion and the cartridge.  
     
     
         42 . An actuator as claimed in    claim 41    wherein said latch member is resilient.  
     
     
         43 . An actuator as claimed in    claim 34    wherein the energy stored by said spring is sufficient to expel a single dose of the liquid.  
     
     
         44 . An actuator as claimed in    claim 34    wherein the energy stored by said spring is sufficient to expel a plurality of successive doses of the liquid.  
     
     
         45 . An actuator as claimed in    claim 34    in combination with a connected cartridge that includes a separately held plurality of components which are to be mixed with one another prior to injection and a mixing member for mixing the plurality of components which one another, said impact member further comprising a mixing means being movable toward the liquid outlet for striking the mixing member, whereby the plurality of components are mixed with one another.  
     
     
         46 . An actuator in combination with a cartridge to form a needle-less injector, comprising: 
 (a) said cartridge being refilled with a liquid to be injected in a subject, said cartridge comprising: 
 (i) a liquid outlet and a free piston inward of the liquid outlet in contact with the liquid;  
 (ii) a separately held plurality of components which are to be mixed with one another prior to injection; and  
 (iii) a mixing member for mixing the plurality of components with one another, wherein the plurality of compartments are separated by at least one partition and said cartridge further has a penetrating member so mounted therein as to be movable to a mixing position in which it penetrates the (or each) partition; and  
   (b) said actuator comprising: 
 (i) a housing adapted to be connected with the cartridge;  
 (ii) impact member mounted within said housing inward of the free piston so as to be movable from a first position toward the liquid outlet to strike the free piston and to continue to move the free piston toward the liquid outlet whereby a dose of the liquid is expelled through the liquid outlet in the cartridge, said impact member further comprising a mixing means being movable toward the liquid outlet for striking the mixing member, said mixing means in striking said mixing member being further operable to move the penetrating member to the mixing position whereby the plurality of components are mixed with one another;  
 (iii) a spring which exerts a force on said impact member when said impact member is in said first position to normally urge said impact member toward the liquid outlet;  
 (iv) a latch within said housing for engaging said impact member to prevent movement of the impact member toward the liquid outlet in response to said force exerted by said spring, and being movable to a firing position for permitting such movement; and  
 (v) means for varying the said dose of liquid.  
   
     
     
         47 . An actuator as claimed in    claim 46   , having means for removably receiving a cartridge.  
     
     
         48 . An actuator as claimed in    claim 47   , in combination with a cartridge, comprising means for retaining said cartridge for engagement with said actuator.  
     
     
         49 . The combination as claimed in    claim 48   , wherein said retaining means are constructed to permit removal of said cartridge.  
     
     
         50 . The combination as claimed in    claim 48   , wherein said retaining means are constructed to permit the fixed mounting of said cartridge.  
     
     
         51 . The combination as claimed in    claim 48   , wherein said cartridge has a body comprising glass.  
     
     
         52 . The combination as claimed in    claim 51   , wherein said glass is transparent.  
     
     
         53 . The combination as claimed in    claim 51   , wherein said free piston of said cartridge comprises a plastics material.  
     
     
         54 . The combination as claimed in    claim 53   , wherein said plastic material is a polymer or copolymer comprising a fluorinated hydrocarbon.  
     
     
         55 . The combination as claimed in    claim 53   , wherein said plastic material is a polytetrafluoroethylene.  
     
     
         56 . The combination as claimed in    claim 53   , wherein said plastic material is selected from the group consisting of tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer, polychlorotrifluoroethylene, poly (vinylidene fluoride), tetrafluoroethylene-perfluoro (propel vinyl ether) copolymer, and hexafluoroisobutylenevinylidene fluoride copolymer.  
     
     
         57 . An actuator for use in conjunction with a cartridge to form a needle-less injector, the cartridge being filled with a liquid to be injected in a subject, the cartridge having a liquid outlet and a free piston inward of the liquid outlet in contact with the liquid, said actuator comprising: 
 (a) a housing having a forward portion adapted to be connected with the cartridge;    (b) an impact member mounted within said housing inward of the forward portion so as to be movable from a first position toward the forward portion to strike the free piston when a cartridge is connected and to continue to move the free piston toward the liquid outlet whereby a dose of the liquid is expelled through the liquid outlet in the cartridge;    (c) a spring which exerts a force on said impact member toward the liquid outlet; and    (d) a latch within said housing which engages said impact member toward the forward portion in response to said force exerted by said spring, and being mounted to be moveable out of engagement with said impact member to a firing position, in which said latch permits such movement, the energy stored by said spring being sufficient to expel a plurality of successive doses of the liquid.    
     
     
         58 . An actuator as claimed in    claim 57   , wherein the said spring is a compression spring.  
     
     
         59 . An actuator as claimed in    claim 58   , further comprising trigger means for operating said latch to thus initiate the injection in response to a predetermined contact force between the liquid outlet of the cartridge and the subject.  
     
     
         60 . An actuator as claimed in    claim 59   , wherein said actuator has a user-holdable portion and means for mounting the cartridge so that the user-holdable portion is movable relative to the cartridge by the liquid outlet of the cartridge being urged into contact with the subject, and said latch comprises a latch member which is movable to said firing position by the relative movement between the user-holdable portion and the cartridge.  
     
     
         61 . An actuator as claimed in    claim 60   , wherein said latch member is resilient.  
     
     
         62 . An actuator as claimed in    claim 57   , in combination with a connected cartridge that includes a separately held plurality of components which are to be mixed with one another prior to injection and a mixing member for mixing the plurality of components with one another, said impact member further comprising a mixing means being movable toward the liquid outlet for striking the mixing member, whereby the plurality of components are mixed with one another.  
     
     
         63 . An actuator in combination with a cartridge to form a needle-less injector, comprising: 
 (a) said cartridge being refilled with a liquid to be injected in a subject, said cartridge comprising:    (i) a liquid outlet and a free piston inward of the liquid outlet in contact with the liquid;    (ii) a separately held plurality of components which are to be mixed with one another prior to injection; and    (iii) a mixing member for mixing the plurality of components with one another, wherein the plurality of compartments are separated by at least one partition and said cartridge further has a penetrating member so mounted therein as to be movable to a mixing position in which it penetrates the (or each) partition; and    (b) said actuator comprising:    (i) a housing adapted to be connected with the cartridge,    (ii) impact member mounted within said housing inward of the free piston so as to be movable from a first position toward the liquid outlet to strike the free piston and to continue to move the free piston toward the liquid outlet whereby a dose of the liquid is expelled through the liquid outlet in the cartridge, said impact member further comprising a mixing means being movable toward the liquid outlet for striking the mixing member, said mixing means in striking said mixing member being further operable to move the penetrating member to the mixing position whereby the plurality of components are mixed with one another;    (iii) a spring which exerts a force on said impact member when said impact member is in said first position to normally urge said impact member toward the liquid outlet; and    (iv) a latch within said housing for engaging said impact member to prevent movement of the impact member toward the liquid outlet in response to said force exerted by said spring, and being movable to a firing position for permitting such movement.    
     
     
         64 . An actuator as claimed in    claim 63   , wherein the movement of said impact member expels a fixed dose.  
     
     
         65 . An actuator as claimed in    claim 63   , wherein the distance of travel of said impact member after striking the free piston is variable to determine the dose of the liquid expelled through the liquid outlet in the cartridge.  
     
     
         66 . An actuator as claimed in    claim 63   , having means for removably receiving a cartridge.  
     
     
         67 . An actuator as claimed in    claim 63   , in combination with a cartridge, comprising means for retaining said cartridge for engagement with said actuator.  
     
     
         68 . The combination as claimed in    claim 67   , wherein said retaining means are constructed to permit removal of said cartridge.  
     
     
         69 . The combination as claimed in    claim 67   , wherein said retaining means are constructed to permit the fixed mounting of said cartridge.  
     
     
         70 . The combination as claimed in    claim 11   , wherein said cartridge has a body comprising glass.  
     
     
         71 . The combination as claimed in    claim 14   , wherein said glass is transparent.  
     
     
         72 . The combination as claimed in    claim 70   , wherein said free piston of said cartridge comprises a plastics material.  
     
     
         73 . The combination as claimed in    claim 72   , wherein said plastic material is polymer or copolymer comprising a fluorinated hydrocarbon.  
     
     
         74 . The combination as claimed in    claim 72   , wherein said plastic material is a polytetrafluoroethylene.  
     
     
         75 . The combination as claimed in    claim 72   , wherein said plastic material is selected from the group consisting of tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-ethylene copolymer, polychlorotrifluoroethylene, poly (vinylidene fluoride), tetrafluoroethylene-perfluoro (propel vinyl ether) copolymer, and hexafluoroisobutylenevinylidene fluoride copolymer.