Abstract: A configuration for a drug delivery system which offers significant advantages over presently available systems. The system provides redundant protection against overdelivery of drug, increased accuracy of delivery, reduced energy requirement, increased capability to clear a blocked catheter, and alarms signifying catheter blockage or valve leakage. The system comprises the series combination of a reservoir, low power electromagnetic pump having spring-biased magnetically actuated piston/plunger and a check valve, pressure sensor, pressure regulator and a catheter. The reservoir supplies a drug at greater than ambient pressure, e.g. 18.7 psia or 4 psi above normal sea level ambient pressure. The pump increases the pressure by 3 psi to 21.7 psia. The pressure sensor tracks the pressure at this location and triggers suitable action by the pump. The pressure regulator downstream of the pressure sensor is configured to hold the pressure at the regulator inlet at a desired level such as 21.7 psia.

Abstract: An electromagnetic pump having a pump body having a fluid containing interior and an inlet and outlet. An accumulator positioned in the fluid containing interior and in fluid communication with the inlet and outlet of the pump. The pump also comprising an armature comprising a pole portion joined to a plunger portion, wherein the plunger portion comprises a one-piece structure including shaft portions of increasing diameters and a head portion comprising a diameter greater than the shaft portions, the plunger portion and a pole portion located internal to the pump housing for magnetic attraction by an electromagnet means. A retainer element is joined with the plunger portion and a main spring urges on the retainer element to move the plunger thus allowing for a return stoke of the plunger as the pump cycles.