Patent ID: 6056727
Filing Date: 2000-05-02
Classification: A61M

Abstract:
Apparatus for patient-controlled infusion of a liquid medicament, the apparatus comprising a reservoir for the medicament, a positive displacement pump having a predetermined working volume, a first conduit connecting the reservoir to the pump, a second conduit connected to and extending from the pump and having a distal end to be inserted in the patient, a one-way valve positioned between the pump and the distal end of the second conduit permitting liquid flow from the pump to the patient and preventing reverse flow, and a dismountable connection means wherein the second conduit being connected to the pump by said dismountable connection means for introducing a priming liquid into the second conduit without the priming liquid passing through the first conduit; the pump being manually operable to displace liquid through the valve and comprising resilient restoring means for returning the pump to its initial state while drawing liquid from the reservoir through the first conduit; and in which the first conduit is a capillary tube and has a length in the range 1 cm to 40 cm and a lumen diameter in the range of 0.025 mm to 0.20 mm whereby the flow rate of liquid medicament through the first conduit is restricted to a rate chosen in conjunction with the working volume of the pump to define a predetermined maximum dosage rate; and wherein the length and the lumen diameter of the first conduit are chosen so as to define a small internal volume which does not affect the operation of the system.