US5447689A
Expired / Lapsed
US
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Method and apparatus for flow control
Assignee: Actimed Laboratories Inc
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Filing: 1994-03-01
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Granted: 1995-09-05
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Expires: 2014-03-01
Abstract
Abstract Sizing materials are applied to porous substrates to retain fluids in the substrate for a discrete period of time. After that time period, the fluid is substantially completely released from the porous substrate. Sizing materials include alkyl ketene dimers, fluorocarbon resins, and fatty acid chlorides.
Inventors
- 👤 David J. Gibboni
- 👤 Susan M. McGeehan
- 👤 Wai T. Law
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 23:39
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/52; G01N33/525; G01N33/53; G01N33/543; G01N33/54366; G01N33/54386; G01N33/54387; G01N33/54388; G01N33/54391
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
105 words
A method for delaying flow of a fluid sample through a porous substrate which is part of a flow delay layer of an analytical device comprising a reagent layer, the flow delay layer positioned below said reagent layer and a measurement zone positioned below said flow delay layer wherein the method comprises the step of coating said porous substrate with a flow delay material wherein said flow delay material retains the fluid in the porous substrate for a predetermined period of time and then permits the fluid to flow substantially completely through said porous substrate to said measurement zone for analysis of the fluid sample.
Claim 2
Independent Claim
105 words
A method for delaying flow of a fluid sample through a porous substrate which is part of a flow delay layer of an analytical device comprising a reagent layer, the flow delay layer positioned below said reagent layer and a measurement zone positioned below said flow delay layer wherein the method comprises the step of coating said porous substrate with a flow delay material wherein said flow delay material retains the fluid in the porous substrate for a predetermined period of time and then permits the fluid to flow substantially completely through said porous substrate to said measurement zone for analysis of the fluid sample.
Claim 3
Dependent Claim
38 words
The method according to claim 1 wherein said flow delay material is a sizing material which slows absorption of fluids onto a surface for a predetermined time, and then permits complete flow of fluid through said porous substrate.
Claim 4
Dependent Claim
26 words
The method according to claim 2 wherein said sizing material is selected from the group consisting of alkyl ketene dimers, fluorocarbon polymers, and fatty acid chlorides.
Claim 5
Dependent Claim
23 words
The method according to claim 3 wherein said sizing delay material is selected from the group consisting of saturated fatty acid ketene dimers.
Claim 6
Dependent Claim
21 words
The method according to claim 4 wherein said ketene dimers are based on fatty acids having at least 14 carbon atoms.
Claim 7
Dependent Claim
14 words
The method according to claim 5 wherein said sizing material is palmitoyl ketene dimer.
Claim 8
Dependent Claim
21 words
The method according to claim 3 wherein said sizing material is a fatty acid chloride having at least 14 carbon atoms.
Claim 9
Dependent Claim
14 words
The method according to claim 3 wherein said sizing material is a fluorocarbon polymer.
Claim 10
Dependent Claim
14 words
The method according to claim 8 wherein said fluorocarbon polymer is substantially completely hydrophobic.
Claim 11
Dependent Claim
19 words
The method according to claim 8 wherein said fluorocarbon polymer is a copolymer having both hydrophilic and hydrophobic groups.
Claim 12
Dependent Claim
17 words
The method according to claim 1 wherein said porous substrate is a pad made of hydrophilic fibers.
Claim 13
Dependent Claim
32 words
The method according to claim 11 wherein said sizing material is present on the pad in an amount ranging from about about 0.001 microgram per pad to about 100 micrograms per pad.
Claim 14
Dependent Claim
36 words
The method according to claim 12 wherein said sizing material is a fluorocarbon polymer and said fluorocarbon polymer is present in an amount of from about 0.0005 microgram per pad to about 0.08 microgram per pad.
Claim 15
Dependent Claim
76 words
An assay device comprising a reagent layer, a flow delay layer below said reagent layer and a measurement zone below said flow delay layer, wherein said flow delay layer comprises a porous substrate coated or impregnated with a sizing material which retains a fluid in the porous substrate for a predetermined period of time and then permits the fluid to flow substantially completely through said porous substrate to said measurement zone for analysis of the fluid.
Claim 16
Dependent Claim
76 words
An assay device comprising a reagent layer, a flow delay layer below said reagent layer and a measurement zone below said flow delay layer, wherein said flow delay layer comprises a porous substrate coated or impregnated with a sizing material which retains a fluid in the porous substrate for a predetermined period of time and then permits the fluid to flow substantially completely through said porous substrate to said measurement zone for analysis of the fluid.
Claim 17
Dependent Claim
26 words
The device according to claim 14 wherein said sizing material is selected from the group consisting of alkyl ketene dimers, fluorocarbon polymers, and fatty acid chlorides.
Claim 18
Dependent Claim
24 words
The device according to claim 15 wherein said sizing material is an alkyl ketene dimer of a fatty acid having least 14 carbon atoms.
Claim 19
Dependent Claim
15 words
The device according to claim 16 wherein said porous substrate is first impregnated with lactose.
Claim 20
Dependent Claim
14 words
The device according to claim 16 wherein said sizing material is palmitoyl ketene dimer.
Claim 21
Dependent Claim
14 words
The device according to claim 16 wherein said sizing material is a fluorocarbon polymer.
Claim 22
Dependent Claim
14 words
The device according to claim 19 wherein said fluorocarbon polymer is substantially completely hydrophobic.
Claim 23
Dependent Claim
19 words
The device according to claim 19 wherein said fluorocarbon polymer is a copolymer having both hydrophilic and hydrophobic groups.
Claim 24
Dependent Claim
17 words
The device according to claim 14 wherein said porous substrate is a pad made of hydrophilic fibers.
Claim 25
Dependent Claim
32 words
The device according to claim 22 wherein said sizing material is present on the pad in an amount ranging from about about 0.001 microgram per pad to about 100 micrograms per pad.
Claim 26
Dependent Claim
36 words
The device according to claim 23 wherein said sizing material is a fluorocarbon polymer and said fluorocarbon polymer is present in an amount of from about 0.0005 microgram per pad to about 0.08 microgram per pad.
Claim 27
Dependent Claim
83 words
An assay device comprising an absorbent pad, a reagent layer below said absorbent pad, a flow delay layer below said reagent layer and a measurement zone below said flow delay layer, wherein said flow delay layer comprises a porous substrate coated or impregnated with a sizing material which retains a fluid in the porous substrate for a predetermined period of time and then permits the fluid to flow substantially completely through said porous substrate to said measurement zone for analysis of the fluid.
Claim 28
Dependent Claim
83 words
An assay device comprising an absorbent pad, a reagent layer below said absorbent pad, a flow delay layer below said reagent layer and a measurement zone below said flow delay layer, wherein said flow delay layer comprises a porous substrate coated or impregnated with a sizing material which retains a fluid in the porous substrate for a predetermined period of time and then permits the fluid to flow substantially completely through said porous substrate to said measurement zone for analysis of the fluid.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1998-09-04 | 1999-03-06 | 1999-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-09-04 | 2003-03-06 | 2003-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-09-04 | 2007-03-06 | 2007-09-05 | $7700.00 | Window Closed / Lapsed |