Patent ID: 7976535
Filing Date: 2011-07-12
Classification: A61M,B01L,F04B

Abstract:
1. A method of controlling the volume flow into or out of an osmotic micropump, the osmotic micropump comprising: a source for an osmotically active solute in a form of a liquid substance, a dispersion of non-dissolved particles in a saturated solution, or a concentrated solution; a supply of a solvent; a lumen comprising a self-sustaining convective flow of solute from the source chamber to an exit, the lumen comprising a semi-permeable membrane; the method comprising steps of: (a) absorbing an amount of concentrated solute from the source chamber into a first portion of the lumen; (b) absorbing a solvent for driving a solution of the solute along a second portion of the lumen by lowering a concentration of the solute in the solution; (c) increasing the concentration of the solute in a third portion of the lumen to maintain the flow; and (d) using iontophoresis or convection for controlling the transfer of the osmotically effective solute from the source into the lumen.