US5658444A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrochemical sensors
Assignee: Medisense Inc
•
Filing: 1994-05-11
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Granted: 1997-08-19
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Expires: 2014-05-11
Abstract
Abstract Erythrocyte exclusion membranes suited for test strips of electrochemical sensors have a porous matrix and a mobile erythrocyte aggregating agent. The membranes typically comprise a water-insoluble hydrophobic polymer incorporating a hydrophilic polymer and with the erythrocyte aggregating agent. Such membranes can have a pore size which is several times larger than the diameter of erythrocytes, and allow rapid passage of plasma by holding back the erythrocytes as rouleaux at the surface of the membrane. The membranes are preferably made by forming in situ on a test strip using spray casting.
Inventors
- 👤 Murdo Black
- 👤 Long Lin
- 👤 James Guthrie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:20
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/14; B01D69/141; C; C12; C12Q; C12Q1/00; C12Q1/001; C12Q1/002; G; G01; G01N; G01N27/00; G01N27/26; G01N27/28; G01N27/30; G01N27/327; G01N27/3271; G01N27/3272; G01N33/00; G01N33/48; G01N33/50; G01N33/5002; G01N27/40; Y; Y10; Y10S; Y10S435/00; Y10S435/817; Y10S435/969; Y10S435/97; Y10S435/975
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
53 words
An erythrocyte exclusion membrane for a sensor, said membrane comprising a porous polymeric matrix including a water-insoluble hydrophobic polymer and a water-soluble hydrophilic polymer in said matrix, wherein said porous matrix comprises pores of pore diameters in the range of 1 to 15 μm, said membrane further comprising a water-soluble erythrocyte aggregating agent.
Claim 2
Dependent Claim
53 words
An erythrocyte exclusion membrane for a sensor, said membrane comprising a porous polymeric matrix including a water-insoluble hydrophobic polymer and a water-soluble hydrophilic polymer in said matrix, wherein said porous matrix comprises pores of pore diameters in the range of 1 to 15 μm, said membrane further comprising a water-soluble erythrocyte aggregating agent.
Claim 3
Dependent Claim
20 words
The membrane of claim 1, said hydrophobic polymer, said hydrophilic polymer and said erythrocyte aggregating agent comprising a single layer.
Claim 4
Dependent Claim
26 words
The membrane of claim 1, comprising first and second layers, said first layer comprising said porous matrix and said second layer including said erythrocyte aggregating agent.
Claim 5
Dependent Claim
10 words
The membrane of claim 1, further including a porous support.
Claim 6
Dependent Claim
25 words
The membrane of claim 1, wherein said hydrophobic polymer is selected from the group consisting of cellulose acetate propionate, cellulose acetate, polyvinyl butyral and polystyrene.
Claim 7
Dependent Claim
24 words
The membrane of claim 1, wherein said hydrophilic polymer is selected from the group consisting of hydroxypropyl cellulose, polyvinylpyrrolidone, polyvinyl alcohol and polyvinyl acetate.
Claim 8
Dependent Claim
29 words
The membrane of claim 1, wherein said erythrocyte aggregating agent is a mobile erythrocyte aggregating agent selected from the group consisting of dextran, polylysine salts, hexadimethrine bromide, and protamine.
Claim 9
Dependent Claim
18 words
The membrane of claim 1, wherein said erythrocyte aggregating agent is more water-soluble than said water-soluble hydrophilic polymer.
Claim 10
Dependent Claim
23 words
The membrane of claim 1, wherein the pores of said porous polymeric matrix have pore diameters in the range 3 to 15 μm.
Claim 11
Dependent Claim
67 words
The membrane of claim 1 wherein said hydrophobic polymer is selected from the group consisting of cellulose acetate propionate, cellulose acetate, polyvinyl butyral and polystyrene, said hydrophilic polymer is selected from the group consisting of hydroxypropyl cellulose, polyvinylpyrrolidone, polyvinyl alcohol and polyvinyl acetate, and said erythrocyte aggregating agent is a mobile erythrocyte aggregating agent selected from the group consisting of dextran, polylysine salts, hexadimethrine bromide, and protamine.
Claim 12
Dependent Claim
23 words
The membrane of claim 10 in which the weight ratio of said hydrophobic polymer to said hydrophilic polymer is from 3:1 to 1:3.
Claim 13
Dependent Claim
31 words
The membrane of claim 11, said hydrophobic polymer, said hydrophilic polymer and said erythrocyte aggregating agent comprising a single layer, said erythrocyte aggregating agent comprising 5 to 45% of said membrane.
Claim 14
Dependent Claim
20 words
The membrane of claim 12 wherein said erythrocyte aggregating agent is more water soluble than said water soluble hydrophilic polymer.
Claim 15
Dependent Claim
28 words
The membrane of any one of claims 10 to 12 wherein the pores of said polymeric matrix have pore diameters in the range of 3 to 15 μm.
Claim 16
Dependent Claim
20 words
The membrane of claim 14 wherein said erythrocyte aggregating agent is more water soluble that said water soluble hydrophilic polymer.
Claim 17
Dependent Claim
77 words
A test strip for an electrochemical sensor for contact with whole blood in order to effect an electrochemical measurement, said test strip having an exclusion membrane in the form of a porous polymeric membrane, said membrane comprising a porous polymeric matrix including a water-insoluble hydrophobic polymer and a water-soluble hydrophilic polymer, wherein said porous matrix comprises pores of pore diameters in the range of 1 to 15 μm, said membrane further comprising a water-soluble erythrocyte aggregating agent.
Claim 18
Dependent Claim
77 words
A test strip for an electrochemical sensor for contact with whole blood in order to effect an electrochemical measurement, said test strip having an exclusion membrane in the form of a porous polymeric membrane, said membrane comprising a porous polymeric matrix including a water-insoluble hydrophobic polymer and a water-soluble hydrophilic polymer, wherein said porous matrix comprises pores of pore diameters in the range of 1 to 15 μm, said membrane further comprising a water-soluble erythrocyte aggregating agent.
Claim 19
Dependent Claim
20 words
The test strip of claim 16, which is an amperometric test strip having electrode areas overlain by said exclusion layer.
Claim 20
Dependent Claim
20 words
The test strip of claim 16, wherein said exclusion layer has a thickness in the range 20 to 50 μm.
Claim 21
Dependent Claim
26 words
The test strip of claim 16, wherein said hydrophobic polymer is selected from the group consisting of cellulose acetate propionate, cellulose acetate, polyvinyl butyral and polystyrene.
Claim 22
Dependent Claim
25 words
The test strip of claim 16, wherein said hydrophilic polymer is selected from the group consisting of hydroxypropyl cellulose, polyvinylpyrrolidone, polyvinyl alcohol and polyvinyl acetate.
Claim 23
Dependent Claim
30 words
The test strip of claim 16, wherein said erythrocyte aggregating agent is a mobile erythrocyte aggregating agent selected from the group consisting of dextran, polylysine sales, hexadimethrine bromide, and protamine.
Claim 24
Dependent Claim
19 words
The test strip of claim 16, wherein said erythrocyte aggregating agent is more water-soluble than said water-soluble hydrophilic polymer.
Claim 25
Dependent Claim
25 words
The test strip of claim 16, wherein the pores of said porous polymeric matrix have pore diameters in the range of 3 to 15 μm.
Claim 26
Dependent Claim
68 words
The test strip of claim 16, wherein said hydrophobic polymer is selected from the group consisting of cellulose acetate propionate, cellulose acetate, polyvinyl butyral and polystyrene, said hydrophilic polymer is selected from the group consisting of hydroxypropyl cellulose, polyvinylpyrrolidone, polyvinyl alcohol and polyvinyl acetate, and said erythrocyte aggregating agent is a mobile erythrocyte aggregating agent selected from the group consisting of dextran, polylysine salts, hexadimethrine bromide, and protamine.
Claim 27
Dependent Claim
24 words
The test strip of claim 24 in which the weight ratio of said hydrophobic polymer to said hydrophilic polymer is from 3:1 to 1:3.
Claim 28
Dependent Claim
32 words
The test strip of claim 25, said hydrophobic polymer, said hydrophilic polymer and said erythrocyte aggregating agent comprising a single layer, said erythrocyte aggregating agent comprising 5 to 45% of said membrane.
Claim 29
Dependent Claim
19 words
The test strip of claim 26, wherein said erythrocyte aggregating agent is more water-soluble than said water-soluble hydrophilic polymer.
Claim 30
Dependent Claim
29 words
The test strip of any one of claims 24 to 26, wherein the pores of said polymeric matrix have pore diameters in the range of 3 to 15 μm.
Claim 31
Dependent Claim
19 words
The test strip of claim 28, wherein said erythrocyte aggregating agent is more water-soluble than said water-soluble hydrophilic polymer.
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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) | 2000-08-18 | 2001-02-17 | 2001-08-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-08-18 | 2005-02-17 | 2005-08-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-08-18 | 2009-02-17 | 2009-08-19 | $7700.00 | Window Closed / Lapsed |