Patent ID: 6692528
Filing Date: 2004-02-17
Classification: A61F,A61L,B01D,C02F,Y02A

Abstract:
A device implantable in an animal body, said device comprising a water-absorbing solute encapsulated by a non-porous, water-permeable polymer membrane,wherein said polymer is a block copolymer having a polyurethane and/or polyurea hard segment and a soft segment selected from the group consisting of polyalkylene oxides, polyalkylene carbonates, poly-siloxanes, and linear or branched hydrocarbons, wherein said membrane has a thickness of 1 to 16 mil and has a moisture vapor transmission rate by ASTM Method E96BW greater than 100 g/square meter/day at 1 mil thickness, a dry tensile strength of greater than 500 psi, and a permeability to said solute of less than 10âˆ’3 cm2/sec, and wherein said solute is capable of providing said device with a pressure of approximately 0.1 psi or more for a period of at least 24 hours.