Patent ID: 6425887
Filing Date: 2002-07-30
Classification: A61B,A61M

Abstract:
A needle assembly comprising:an infusion needle having a plurality of needle cannulae each having a distal tip, the plurality of needle cannulae, while in their unconstrained configuration, each having a preformed bend proximate to a respective said distal tip with an angle within a range from 40 to 90Â°, the preformed bends further comprising mechanically-induced martensite with straight portions of said inner hollow cannula comprised of austenitic state Niâ€”Ti alloy, the plurality of needle cannulae constrainable to a second configuration that is substantially straight, whereby at release of external constraining forces, the plurality of needle cannulae substantially return to their unconstrained configurations, the needle cannulae comprising a Niâ€”Ti alloy, the preformed bends of the plurality of needle cannulae induced by mechanically deforming the needle cannulae, each preformed bend includes a martensitic crystalline structure, while non-mechanically deformed portions of the needle cannulae comprise a substantially austenitic crystalline structure; a coaxial outer cannula having a distal end and a passageway therethrough, the needle cannulae adapted to be disposed inside the passageway of the coaxial outer cannula to constrain the needle cannulae into the second configuration; the needle cannulae being slidably deployable from the distal end of coaxial outer cannula whereby at release of constraining forces from said distal tips and said preformed bends, the plurality of needle cannulae substantially return to their unconstrained configurations with respective said distal tips thereof extending in respective directions forwardly and radially outwardly from respective said preformed bends; an inner needle introducer stylet having a stylet shaft, the stylet shaft being insertable into the passageway of the infusion needle; and an outer cannula introducer stylet that is insertable into the passageway of the coaxial outer needle such that the coaxial outer needle and outer cannula introducer stylet comprise an outer needle assembly adapted for insertion into the body of a patient.