US3788124A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gas concentration measuring
Assignee: Individual
•
Filing: 1971-12-20
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Granted: 1974-01-29
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Expires: 1991-12-20
Abstract
Abstract A method and associated apparatus for detecting a safe low percentage residual concentration of a sterilizing gas such as ethylene oxide being eluted from an item previously sterilized by the gas. The elution of the gas from the item may be accomplished by a heated forced air technique or, alternatively, by a vacuum technique. A concentration sensor is subjected to a sampled amount of the eluted ethylene oxide and preferably forms a branch of a bridge circuit which includes means for registering the amount of ethylene oxide eluted which is a function of the amount of residue still retained by the item. The concentration of ethylene oxide is preferably indicated by a meter in parts per million. When a safe low level of residue, such as 500 ppm (parts per million), is detected a SAFE indicator light may be illuminated or an audible alarm sounded. One aspect of the present invention is the provision for a set point control which can be adjusted to change the SAFE/UNSAFE concentration level to, for example, 300 ppm, or any other level considered acceptable.
Inventors
- 👤 A Teton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 03:15
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/14; G01N27/16
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
213 words
Apparatus for lowering the concentration of ethylene oxide residue remaining in a previously sterilized item and for determining when a safe low level of ethylene oxide is present, said apparatus comprising; means defining a chamber for containing one or more items and including an input port open to an air supply and through which air may pass, an output port in said chamber through which the eluted ethylene oxide passes, means coupled to the chamber for forcing the ethylene oxide to the output port, means for heating the one or more items to hasten the elution of the ethylene oxide, electrical means receptive to eluted ethylene oxide for measuring the concentration of the ethylene oxide, said electrical means including means for indicating concentrations of ethylene oxide in the range of 0 to 1,000 parts per million to indicate a safe low level of concentration when the measured concentration falls to a predetermined safe level, said output port being defined at least in part by a funnelshaped bottom member having a passage through which the eluted ethylene oxide passes, a means for supporting said one or more items above said funnelshaped bottom member while allowing passage of gas therethrough, said input port being defined at least in part by a top intake plenum chamber.
Claim 2
Dependent Claim
213 words
Apparatus for lowering the concentration of ethylene oxide residue remaining in a previously sterilized item and for determining when a safe low level of ethylene oxide is present, said apparatus comprising; means defining a chamber for containing one or more items and including an input port open to an air supply and through which air may pass, an output port in said chamber through which the eluted ethylene oxide passes, means coupled to the chamber for forcing the ethylene oxide to the output port, means for heating the one or more items to hasten the elution of the ethylene oxide, electrical means receptive to eluted ethylene oxide for measuring the concentration of the ethylene oxide, said electrical means including means for indicating concentrations of ethylene oxide in the range of 0 to 1,000 parts per million to indicate a safe low level of concentration when the measured concentration falls to a predetermined safe level, said output port being defined at least in part by a funnelshaped bottom member having a passage through which the eluted ethylene oxide passes, a means for supporting said one or more items above said funnelshaped bottom member while allowing passage of gas therethrough, said input port being defined at least in part by a top intake plenum chamber.
Claim 3
Dependent Claim
18 words
The apparatus of claim 1 wherein said electrical means includes meter means for indicating concentrations of ethylene oxide.
Claim 4
Dependent Claim
23 words
The apparatus of claim 2 wherein said electrical means includes visual means for indicating a safe low level of concentration of ethylene oxide.
Claim 5
Dependent Claim
27 words
The apparatus of claim 2 including means for venting the eluted ethylene oxide from the apparatus so that said meter means has a gradually decreasing concentration indication.
Claim 6
Dependent Claim
41 words
The apparatus of claim 1 including a first screen means for supporting said one or more items above said funnel-shaped bottom member, and a second screen disposed near the top of the chamber and defining in part the intake plenum chamber.
Claim 7
Dependent Claim
29 words
The apparatus of claim 5 wherein both said screen means include perforated metal plates and said first screen means has a larger perforated area than the second screen means.
Claim 8
Dependent Claim
27 words
The apparatus of claIm 1 comprising means for changing the predetermined level to a different level in the concentration range of 0 to 1,000 parts per millon.
Claim 9
Dependent Claim
18 words
The apparatus of claim 7 wherein said predetermined level is on the order of 500 parts per million.
Claim 10
Dependent Claim
42 words
The apparatus of claim 1 wherein said means for indicating includes a bistable device assuming a first state indicating a safe level at concentrations below the predetermined level and a second state indicating an unsafe level at concentrations above the predetermined level.
Claim 11
Dependent Claim
29 words
The apparatus of claim 1 wherein said chamber is relatively large in comparison to said input and output ports so as to provide relatively rapid aeration of the item.
Claim 12
Independent Claim
175 words
A method of lowering the concentration of ethylene oxide residue remaining in an item which has been sterilized with ethylene oxide and for determining when a safe low level of ethylene oxide is present, said method comprising, positioning the sterilized item in a chamber having an input port opened to an air supply and through which gas may pass and an outlet means through which both eluted ethylene oxide and air pass, heating the item and forcing ethylene oxide residue to be eluted therefrom, passing an air stream over the item to cause the eluted ethylene oxide to mix therewith, electrically sampling the ethylene oxide in the outlet air stream and measuring the concentration of ethylene oxide in the air which concentration is a function of the residue contained in the item while simultaneously continuously venting the eluted ethylene oxide to an area remote from the chamber, and providing an indication when a predetermined safe low level of ethylene oxide concentration in the range of from 0 to 1,000 parts per million has been attained.
Claim 13
Independent Claim
175 words
A method of lowering the concentration of ethylene oxide residue remaining in an item which has been sterilized with ethylene oxide and for determining when a safe low level of ethylene oxide is present, said method comprising, positioning the sterilized item in a chamber having an input port opened to an air supply and through which gas may pass and an outlet means through which both eluted ethylene oxide and air pass, heating the item and forcing ethylene oxide residue to be eluted therefrom, passing an air stream over the item to cause the eluted ethylene oxide to mix therewith, electrically sampling the ethylene oxide in the outlet air stream and measuring the concentration of ethylene oxide in the air which concentration is a function of the residue contained in the item while simultaneously continuously venting the eluted ethylene oxide to an area remote from the chamber, and providing an indication when a predetermined safe low level of ethylene oxide concentration in the range of from 0 to 1,000 parts per million has been attained.
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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) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |