Patent ID: 6605060
Filing Date: 2003-08-12
Classification: A61M,B05B

Abstract:
A delivery device for patient-controlled infusion of a medicament, the delivery device comprising:(i) a reservoir for the medicament; (ii) a first conduit comprising fine calibre tube with a lumen diameter of about 0.001 mm to 0.2 mm and a length of between 1 and 700 cm; (iii) a pumping means comprising (a) a dose chamber in fluid communication with the first conduit via a one-way valve that permits medicament flow into the chamber but prevents reverse flow there from, (b) a resilient restoring means capable of drawing medicament through the first conduit into the dose chamber following displacement of medicament from the dose chamber, (c) a controlling means in fluid communication with the dose chamber which has a minimum opening pressure of greater than 800 mmHg but less than 5000 mmHg and which prevents the reverse flow of medicament and air into the dose chamber, and (d) a second conduit in fluid communication with the controlling means having a distal end through which the medicament may be released; and wherein: (a) an effective dose of medicament is only dispensed from the dose chamber when the pressure threshold capable of being generated in the dose chamber through actuation of the device exceeds the minimum opening pressure of the controlling means and is sufficient to discharge the medicament. through the second conduit with sufficient velocity to atomise or nebulise the medicament; and (b) following displacement of medicament from the dose chamber the filling time of the dose chamber is greater than 1 minute.