The Magnetic Plungerless Injection System (MPIS) was invented to enhance the therapeutic value and market availability of parenterally delivered pharmaceuticals and vaccines. The MPIS is a mechanical arrangement of a proprietary single-dosage cartridge and a magnetic actuator, and is a combination of the storage and the injector/extractor (syringe). The design answers many questions raised by the existing hypodermic syringe.

The MPIS is a handheld apparatus with a magnetically driven piston capable of displacing, moving, and transferring liquid or gas through a cartridge chamber and into a sterile needle for injections. The device can also be applied to extract liquid or gas substances. This apparatus works on the principle that a magnetic field penetrates the glass and plastic walls of the cartridge. A magnet located on the outside of the cartridge wall and a ferrous piston on the inside of the cartridge create a strong coupling, with the ferrous piston repeating the movements of the magnet. Movement of the piston in one direction generates insertion of liquid and/or gas substances and movement in the other direction produces an extraction.

This device incorporates storage for solid, gas, and liquid substances, and an injection system for gases and liquids at the same time. The double-sided needle assembly provides a link between the subject of insertion or extraction and the chamber, either pre-filled with pharmaceutical agents or empty. The long end of the needle is inserted into the subject and the short end is inserted into the chamber through a rubber stopper. The chamber remains completely sealed and sterile until the rubber stopper is punctured all the way through by the short end of the needle.

The Magnetic Plungerless Injection System consists of: 1) chamber (cartridge) for gas/liquid displacement, movement, and transfer; 2) movable magnet; 3) rodless piston (ferrous material that interacts with the magnet); 4) adjustable guards (to adapt to different size cartridges); 5) frame; 6) handle; 7) trigger (magnet moving mechanism); and 8) needle assembly.

The trigger mechanism utilizing magnets and magnetic energy to inject and/or withdraw liquids and gasses eliminates a plunger mechanism. All dosages come in a completely sealed cartridge that has a shelf life limited only by the stability of the drug inside. Costs of injection are reduced by eliminating ampoules, vials, syringes, pre-filled syringes, and short-shelf-life cartridges; simplification of the drug manufacturing process; reduction in the FDA-controlled inspection steps; and less packaging, shipping, and handling.

Beyond medical and veterinary, other potential applications include multicompound glues, refill cartridges for computer printers, and biological, radioactive, and chemical sampling and testing.

This technology is offered by PATEV® Global IP Management. For more information, view the TechPak at

Medical Design Briefs Magazine

This article first appeared in the November, 2009 issue of Medical Design Briefs Magazine.

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