COMPOSITE H2O ABSORBER FOR SEALED MEDICAL DEVICES

• US 20110113959A1
• Filed: 07/09/2009
• Published: 05/19/2011
• Est. Priority Date: 07/25/2008
• Status: Active Grant

• Current Assignee: SAES Getters SpA (SAES Getters S)
• Original Assignee: SAES Getters SpA (SAES Getters S)
• Inventors: Bonucci, Antonio, Cattaneo, Lorena, Rondena, Sergio
• Granted Patent: US 8,673,060 B2
• Time in Patent Office: Days
• US Class Current: 95/117
• CPC Class Codes: B01J 20/041 Oxides or hydroxides
• CPC Class Codes: B01J 20/08 comprising aluminium oxide or hydroxide; comprising bauxite
• CPC Class Codes: B01J 20/103 comprising silica
• CPC Class Codes: B01J 20/165 Natural alumino-silicates, e.g. zeolites
• CPC Class Codes: B01J 20/18 Synthetic zeolitic molecular sieves
• CPC Class Codes: B01J 20/261 obtained by reactions only involving carbon to carbon unsaturated bonds macromolecular compounds obtained by reactions only involving carbon-to-carbon unsaturated bonds per se C08F
• CPC Class Codes: B01J 20/264 derived from different types of monomers, e.g. linear or branched copolymers, block copolymers, graft copolymers
• CPC Class Codes: B01J 20/28004 Sorbent size or size distribution, e.g. particle size
• CPC Class Codes: B01J 20/28026 Particles within, immobilised, dispersed, entrapped in or on a matrix, e.g. a resin
• CPC Class Codes: B01J 20/28033 Membrane, sheet, cloth, pad, lamellar or mat
• CPC Class Codes: F26B 21/083 by using sorbent or hygroscopic materials, e.g. chemical substances, molecular sieves

Abstract

There are described composite absorbers for sealed medical devices, which comprise an active species dispersed in a polymeric matrix having an H₂O transmission comprised between 0.05 g mm ⁻² d⁻¹ and 5.4 g mm m⁻² d⁻¹ at 25° C. and 100% RH, and a method for H₂O removal from the sealed medical devices by means of said composite absorbers.

Claims

1. A composite H₂O absorber for sealed medical devices comprising an active species dispersed in a polymeric matrix, characterized in that said polymeric matrix shows a Moisture Vapour Transmission Rate comprised between 0.05 g mm m⁻

2 d<sup>−

1</sup> and 5.4 g mm m<sup>−

2</sup> d<sup>−

1</sup> at 25°

C. and 100% RH.

2. The absorber of claim 1, wherein said polymeric matrix has as a main constituent one among the following materials:

Ethylene-Vinyl Acetate, low density polyethylenes, medium density polyethylenes, high density polyethylenes, polyether-block-amide, ionomeric resins, copolymers ethylene acrylic acids, polyvinyl fluoride, PolyVinylButyral, polyvinyl chloride, butyl rubbers, EPR rubbers, EPDM rubbers.

3. The absorber of claim 1, wherein said dispersed active species comprises one or more among zeolites, silica gel, alumina, alkali metal oxides and alkaline-earth metal oxides.

4. The absorber of claim 1 or 2, wherein said dispersed active species comprises active species capable to absorb one or more additional noxious compounds.

5. The absorber of claim 4, wherein said additional noxious compounds are hydrogen, carbon dioxide, carbon monoxide, hydrocarbons.

6. The absorber of claim 1, wherein the weight percentage of said active species with respect to the composite absorber is comprised between 10% and 50%.

7. The absorber of claim 1, wherein the thickness of said absorber is comprised between 0.15 and 2 mm.

8. A method for H₂O removal from sealed medical devices by introducing in said devices a composite absorber comprising one active species dispersed in a polymeric matrix, characterized in that said polymeric matrix shows a Moisture Vapour Transmission Rate comprised between 0.05 g mm m⁻

2 d<sup>−

1</sup> and 5.4 g mm m<sup>−

2</sup> d<sup>−

1</sup> at 25°

C. and 100% RH.

9. The method of claim 8, wherein said active species comprises one or more among zeolites, silica gel, alumina, alkali metal oxides, alkaline-earth metal oxides.

10. The method of claim 9, wherein said alkaline-earth metal oxides comprise calcium oxide, barium oxide or combinations thereof.

11. The method of claim 10, wherein said sealed medical devices operate at temperatures of 65°

C. or higher and the active species comprises calcium oxide.

12. The method of claim 8, wherein the introduction of the composite absorber inside the sealed medical device comprises a cutting phase of an absorber sheet having indefinite length and width, and a thickness comprised between 0.15 and 2 mm.

13. The method of claim 8, wherein said sealed medical devices are pacemakers, neurostimulators, acoustic aids, defibrillators, or electromechanical systems for the controlled release of drugs.