Patent ID: 6224572
Filing Date: 2001-05-01
Classification: A61M

Abstract:
A fluid delivery device for delivering fluid to a patient comprising:inlet means configured for placement in fluid communication with a fluid reservoir containing a supply of the fluid;outlet means disposed in fluid communication with the inlet means such that said inlet and outlet means reside in series;a housing defining an intermediate dosing chamber therein disposed between and in fluid communication with the inlet means and the outlet means, said housing including a piston receiving opening in communication with the chamber;a resilient sheet of material disposed over the piston receiving opening and including an aperture positioned in alignment with said opening, wherein cross-sectional dimensions of the aperture do not exceed cross-sectional dimensions of the chamber;an elongate piston slidably disposed in the aperture of the resilient sheet so that one end of the piston extends into the chamber;shaft means coupled to a proximal end of the piston;first and second shape memory means attached to opposing portions of the shaft means, said first shape memory means being operable to move the piston to the first position when said first shape memory means is caused to contract, and said second shape memory means being operable to move the piston to the second position when said second shape memory means is caused to contract; andmeans for alternately passing electrical current through the first and second shape memory means to thereby alternately cause the first shape memory means and the second shape memory means to contract in alternating tandem, so as to cause said piston to slide back and forth through the aperture in a reciprocating motion between first and second positions to pump fluid from the reservoir through the outlet means and to the patient by alternately producing a negative and a positive pressure within the chamber.