Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
  • A61M5/178—Syringes
  • A61M5/30—Syringes for injection by jet action, without needle, e.g. for use with replaceable ampoules or carpules
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
  • A61M5/178—Syringes
  • A61M5/20—Automatic syringes, e.g. with automatically actuated piston rod, with automatic needle injection, filling automatically
  • A61M5/2053—Media being expelled from injector by pressurised fluid or vacuum

Definitions

• the present invention pertains to needleless injectors and more particularly to a needleless jet injector for mass inoculation. SUMMARY OF THE INVENTION
• the invention provides, in a first aspect, a needleless jet injector device for use with a supply of gas under pressure and medicament, the device comprising a body having a gas inlet for said gas and a medicament inlet for said medicament, a first chamber communicating with said medicament inlet and having an outlet, a jet nozzle communicating with said outlet so as to receive medicament, under pressure, for injection, a second chamber communicating with said gas inlet, a first piston at least partly defining said first chamber and movable to vary the volume thereof so as to deliver a dose of medicament under pressure to said outlet, a second piston at least partly defining said second chamber and movable to vary the volume thereof, connection means coupling the first and second pistons so that movement of said second piston causes movement of said first piston, medicament flow control means to operatively restrict flow of the medicament from the medicament inlet to said first chamber, and control means to regulate the flow of gas to said second chamber to cause movement of said second piston and therefor movement of said first piston.
• the medication is carried by a backpack which supplies the injector.
• the injector preferably automatically reloads a medication cylinder upon the release of a trigger mechanism at the completion of each injection. It is preferred that the dosage be readily adjustable by means of a piston stroke adjuster.
• Figure 1 is a cross-sectional view of one embodiment of a jet injector according to the present invention
• Figure 2 is a perspective view of the injector of Figure 1 and a backpack used to carried medicament and propellant.
• a needleless jet injector 100 comprises a nozzle 1 through which a high pressured jet is discharged.
• a check valve 2 opens, allowing medication to pass through the nozzle 1.
• the check valve 2 closes on the intake stroke of the piston 3 to prevent air from being drawn into the interchangeable medication cylinder 22.
• medication is alternately drawn into the cylinder 22 and discharged through the nozzle 1.
• a medication transfer tube 4 enables medication to be transferred from a medication receiver 6 to the medication cylinder 22.
• a check valve 5 closes on the delivery stroke of the piston 3 preventing medication from passing back into the receiver 6.
• the check valve 5 opens on the intake stroke of the piston to allow medication to flow from the receiver 6 to the cylinder 22.
• the medication receiver 6 is a chamber within the body of the injector which receives and holds medication from an external source such as a backpack.
• a cylinder vent 7 is provided through the rear of the medication cylinder.
• the piston rod 8 connects the delivery pi ton 3 to a CO- piston 9.
• a pressurized gas such as C0 2
• C0 2 release valve 14 if open
• a collar stop 10 is provided in the chamber 24 for limiting and adjusting the return stop position of the piston 9.
• a worm and rack mechanism 11 responds to rotation of the stroke adjuster 12, moving the stop 10 forward and backward in a linear fashion thereby altering the stroke of the piston 9.
• the CO- release valve 14 is opened by actuation of the trigger and lever mechanism 20 acting through the release valve actuator 15. Opening the CO- release valve 14 allows pressurized gas to travel from the receiving chamber 13, into the delivery chamber 24 and hence into the working portion of the cylinder 23 for the purpose of displacing the piston 9.
• a release valve actuator 15 is provided which, upon upward deflection of the trigger and lever mechanism 20, opens the C0 2 release valve 14 and closes the C0 2 cylinder vent valve 16. With the trigger and lever mechanism 20 still held in the upward deflected position, the release valve actuator 15 allows the release valve 14 to close, stopping the flow of pressurized gas into the delivery chamber 24 at the completion of the delivery stroke.
• the cylinder vent valve 16 opens upon the release of the trigger and lever mechanism 20 and allows the cylinder 23 to be vented to the atmosphere via the cylinder port 17, lever port 18 and handle vent 19.
• a transfer valve 21 opens and allows pressurized gas to fill the return chamber 25.
• the cylinder vent valve 16 opens and the cylinder 23 is vented to atmosphere which in turn allows the pressurized gas in the return chamber 25 to drive the piston 9 back to the collar stop 10. With the return travel of the piston 9, the piston 3 draws medication into the medication cylinder 22.
• a trigger operated jet injector needleless syringe 100 may be used in conjunction with a backpack harness 101.
• the harness 101 may be used to support a medicament cylinder 102 and a liquid carbon dioxide cylinder 103.
• the contents of the medicament and C0 2 cylinders are discharged through a manifold 104 and through separate hoses 105, 106 to the respective intake ports of the injector 100.
• the backpack harness may consist of a rigid mounting frame which includes waist and shoulder straps which can be adjusted to the wearer's needs.
• the CO- and medicament manifold(s) may either be attached to the harness or separately attached to each of the cylinders.
• the pressurized gas cylinder preferably a carbondioxide cylinder, will be a high pressure cylinder containing approximately 2.5 kilograms of liquid carbon dioxide which is used as the pressure medium for actuating the piston 9.
• the medicament cylinder may be an unpressurized vessel of light weight material to contain the particular medicament used in a particular inoculation program. Like the pressurized gas cylinder it is readily replacable and refillable. Both the medicament cylinder 22 and nozzle 1 of the injector 100 are replacable.
• the cylinder may be tailored to suit the correct dosage of a particular medicament.
• the nozzle contains a very fine bore which, on release of the piston under the gas pressure, will create a high pressure, high velocity jet. The nature of the high velocity jet through the fine bore creates wear within the bore and after a period of time, this wear will reduce the efficiency of penetration of the medicament. The nozzle is therefore readily replacable in the field at the first sign of reduced efficiency which will be noticable by wetting of the skin surface.
• the injector portion 100 may be provided in two or more sizes utilising the same operating principles.
• a larger robust unit is particularly suited to mass inoculation of sheep, cattle, pigs and other animals.
• a smaller unit is more suitable for the mass inoculation of children and adults.
• a major benefit of this invention is the fully automatic reloading and recharging for rapid multiple injections.
• the unit is fully adjustable in both dosage and charge for difference thickness skins and different sizes of animals. Because it is a needleless syringe, it completely eliminates the problem of cross contamination or infection which exists with mass inoculation with multiple use needles.

Landscapes

• Health & Medical Sciences (AREA)
• Vascular Medicine (AREA)
• Engineering & Computer Science (AREA)
• Anesthesiology (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• Hematology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Infusion, Injection, And Reservoir Apparatuses (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=3775128

Family Applications (1)

Country Status (3)

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Citations (6)

Family Cites Families (3)

• 1991
  • 1991-12-06 EP EP19920900565 patent/EP0560856A4/en not_active Withdrawn
  • 1991-12-06 CA CA002097919A patent/CA2097919A1/fr not_active Abandoned
  • 1991-12-06 WO PCT/AU1991/000566 patent/WO1992010226A1/fr not_active Application Discontinuation

Patent Citations (6)

Non-Patent Citations (1)

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