Needleless injector

• US 20050256448A1
• Filed: 04/28/2005
• Published: 11/17/2005
• Est. Priority Date: 10/26/2001
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Hunter, Ian W., Angel, Aimee B.
• Granted Patent: US 7,425,204 B2
• Time in Patent Office: Days
• US Class Current: 604/68
• CPC Class Codes: A61M 2205/0266 Shape memory materials
• CPC Class Codes: A61M 2205/0272 Electro-active or magneto-active materials
• CPC Class Codes: A61M 5/30 Syringes for injection by jet action, without needle, e.g. for use with replaceable ampoules or carpules
• CPC Class Codes: A61M 5/31511 Piston or piston-rod constructions, e.g. connection of piston with piston-rod A61M5/5066 takes precedence
• CPC Class Codes: F03G 7/065 using a shape memory element

Abstract

An injector includes a housing having a chamber for holding a liquid formulation of an active principle to be injected into a biological body and an output port in fluid communication with the chamber through which the liquid formulation is injected. A piston is positioned within the housing, and includes an end portion with substantially the same shape as the chamber. A magnetic force draws the piston and housing together to expel the liquid formulation out of the chamber through the output port.

Claims

1. An actuator, comprising:

a contracting material under tension, the tension being produced by a magnetic force; and

a capacitor which discharges a potential to the fiber to cause the fiber to contract, the fiber relaxing to a stretched state when the potential is removed.