US4207286A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Seeded gas plasma sterilization method
Assignee: Wave Energy Systems Inc
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Filing: 1978-03-16
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Granted: 1980-06-10
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Expires: 1998-03-16
Abstract
Abstract A method to sterilize the surfaces of objects placed in a continuous flow of a low temperature, low pressure gas plasma, containing small amounts of aromatic, heterocyclic and saturated or unsaturated acyclic aldehydes alone or mixtures thereof. Said gas plasma is a partially ionized gas composed of ions, electrons and neutral species. It is created by electromagnetic discharges at subatmospheric pressure in the 1 to 10,000 Megahertz range, and corresponds to a minimum average spatial energy density of 0.001 watts per cubic centimeter. The gas plasma may also contain other vaporized cidal agents. Contrary to most sterilant gases, the method is safe, allows quick handling of heat sensitive items, does not corrode equipment and does not leave toxic residues.
Inventors
- 👤 Raymond M. Gut Boucher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:48
CPC Classifications
A; A01; A01N; A01N43/00; A01N43/02; A01N43/04; A01N43/06; A01N43/08; A01N35/00; A01N35/02; A01N35/04; A61; A61L; A61L2/00; A61L2/02; A61L2/14
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
27 words
A method of sterilizing a surface comprising contacting said surface with a low temperature gas plasma containing at least 10 mg/l of an aldehyde under subatmospheric pressure.
Claim 2
Independent Claim
27 words
A method of sterilizing a surface comprising contacting said surface with a low temperature gas plasma containing at least 10 mg/l of an aldehyde under subatmospheric pressure.
Claim 3
Dependent Claim
29 words
A method in accordance with claim 1 wherein the aldehyde is at least one member selected from the group consisting of aromatic, heterocyclic and saturated and unsaturated acyclic aldehydes.
Claim 4
Dependent Claim
36 words
A method in accordance with claim 1 wherein said gas plasma is produced from electromagnetic excitation of at least one gas selected from the group consisting of oxygen, argon, helium, nitrogen, carbon dioxide and nitrogen oxide.
Claim 5
Dependent Claim
24 words
A method in accordance with claim 1 wherein the pressure of said gas plasma is equal to or greater than 0.1 mm. of mercury.
Claim 6
Dependent Claim
26 words
A method in accordance with claim 1 wherein said gas plasma is produced by gaseous electromagnetic discharges in the 1 to 100 MHz radio frequency region.
Claim 7
Dependent Claim
25 words
A method in accordance with claim 1 wherein said gas plasma is produced by gaseous electromagnetic discharges in the 100 to 300,000 MHz microwave range.
Claim 8
Dependent Claim
37 words
A method in accordance with claim 1 wherein said gas plasma is confined inside a fluid-tight container or chamber into which the electromagnetic field density is at least equal to 0.001 watts per cubic centimeter of space.
Claim 9
Dependent Claim
36 words
A method in accordance with claim 1 wherein said gas plasma contains at least one aldehyde selected from the group consisting of formaldehyde, acetaldehyde, glyoxal, malonaldehyde, propionaldehyde, succinaldehyde, butyraldehyde, glutaraldehyde, 2-hydroxyadipaldehyde, acrolein, crotonaldehyde, benzaldehyde, and 2-furaldehyde.
Claim 10
Dependent Claim
25 words
A method in accordance with claim 1 wherein the aldehyde vapors are introduced in a continuously produced gas plasma upstream in a carrier gas flow.
Claim 11
Dependent Claim
24 words
A method in accordance with claim 1 wherein the aldehyde vapors are introduced in a continuously produced gas plasma inside a plasma processing chamber.
Claim 12
Dependent Claim
54 words
A method in accordance with claim 1 wherein said gas plasma will also contain in an amount equal to or greater than ten milligrams per liter of said gas plasma of at least one vaporized biocidal agent selected from the group consisting of phenols, halogens, inorganic and organic metallic salts, organosulfur and nitrogen compounds.
Claim 13
Independent Claim
133 words
A method of sterilizing surfaces, comprising: (a) placing the surface to be sterilized in a fluid-tight chamber; (b) evacuating said chamber to a pressure equal to or greater than 0.1 mm. of mercury; (c) introducing into the evacuated chamber a gas containing at least ten milligrams per liter of at least one vaporized aldehyde selected from the group consisting of aromatic, heterocyclic and saturated and unsaturated acyclic aldehydes per liter of gas plasma; (d) establishing an electromagnetic field in the 1 to 10,000 MHz range with an average spatial density of energy of at least 0.001 watts per cubic centimeter of chamber; (e) maintaining the abovementioned electromagnetic field for a time long enough to completely destroy all living microorganisms while not affecting the physical or chemical properties of the object to be decontaminated.
Claim 14
Independent Claim
133 words
A method of sterilizing surfaces, comprising: (a) placing the surface to be sterilized in a fluid-tight chamber; (b) evacuating said chamber to a pressure equal to or greater than 0.1 mm. of mercury; (c) introducing into the evacuated chamber a gas containing at least ten milligrams per liter of at least one vaporized aldehyde selected from the group consisting of aromatic, heterocyclic and saturated and unsaturated acyclic aldehydes per liter of gas plasma; (d) establishing an electromagnetic field in the 1 to 10,000 MHz range with an average spatial density of energy of at least 0.001 watts per cubic centimeter of chamber; (e) maintaining the abovementioned electromagnetic field for a time long enough to completely destroy all living microorganisms while not affecting the physical or chemical properties of the object to be decontaminated.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-06-10 | 1983-12-10 | 1984-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-06-10 | 1987-12-10 | 1988-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-06-10 | 1991-12-10 | 1992-06-10 | $7700.00 | Window Closed / Lapsed |