US6284125B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrochemical cell
Assignee: LifeScan Inc
•
Filing: 1996-06-19
•
Granted: 2001-09-04
•
Expires: 2016-06-19
Abstract
Abstract A method for determining the concentration of a reduced (or oxidised) form of a redox species in an electrochemical cell of the kind comprising a working electrode and a counter electrode spaced from the working electrode by a predetermined distance, said method comprising the steps of: (1) applying an electric potential difference between the electrodes; (2) selecting the potential of the working electrode such that the rate of electro-oxidation of the reduced form (or electro-reduction of the oxidised form) of the species is diffusion controlled, (3) selecting the spacing between the working electrode and the counter electrode so that reaction products from the counter electrode arrive at the working electrode; (4) determining current as a function of time after application of the potential and prior to achievement of a steady state; (5) estimating the magnitude of the steady state current, and (6) obtaining from the change in current with time and the magnitude of the steady state current, a value indicative of the diffusion coefficient and/or of the concentration of the reduced form (or the oxidised form) of the species. Also disclosed is an apparatus for determining the concentration of a redox species in an electrochemical cell comprising: an electrochemical cell having a working electrode and a counter (or counter/reference) electrode, means for applying and electric potential difference between said electrodes, means for measuring the change in current with time, and characterised in that the working electrode is spaced from the counter electrode by less than 500 μm.
Inventors
- 👤 Alastair McIndoe Hodges
- 👤 Thomas William Beck
- 👤 Oddvar Johansen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:48
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/001; C12Q1/004; C12Q1/005; C12Q1/006; G; G01; G01N; G01N27/00; G01N27/26; G01N27/28; G01N27/30; G01N27/327; G01N27/3271; G01N27/3273
Claims Analysis
Total Claims: 112
Claim 1
Independent Claim
169 words
A method for determining the concentration of a reduced or oxidized form of a redox species, said method comprising the steps of: (1) providing an electrochemical cell comprising a working electrode and a counter electrode, (2) applying an electric potential difference between the electrodes, (3) selecting the potential of the working, electrode such that the rate of electro-oxidation of the reduced form or electro-reduction of the oxidized form of the species is diffusion controlled, (4) selecting the spacing between the working electrode and the counter electrode so that reaction products from the counter electrode arrive at the working electrode, (5) determining current as a function of time after application of the potential and prior to achievement of a steady state, (6) estimating the magnitude of the steady state current, and (7) obtaining from the change in current with time and the magnitude of the steady state current, a value indicative of the diffusion coefficient and/or of the concentration of the reduced form or the oxidized fonn of the species.
Claim 2
Independent Claim
169 words
A method for determining the concentration of a reduced or oxidized form of a redox species, said method comprising the steps of: (1) providing an electrochemical cell comprising a working electrode and a counter electrode, (2) applying an electric potential difference between the electrodes, (3) selecting the potential of the working, electrode such that the rate of electro-oxidation of the reduced form or electro-reduction of the oxidized form of the species is diffusion controlled, (4) selecting the spacing between the working electrode and the counter electrode so that reaction products from the counter electrode arrive at the working electrode, (5) determining current as a function of time after application of the potential and prior to achievement of a steady state, (6) estimating the magnitude of the steady state current, and (7) obtaining from the change in current with time and the magnitude of the steady state current, a value indicative of the diffusion coefficient and/or of the concentration of the reduced form or the oxidized fonn of the species.
Claim 3
Dependent Claim
31 words
A method according to claim 1 wherein a steady state concentration profile of electrochemical reaction products is achieved between the working electrode and counter electrode during the period of a test.
Claim 4
Dependent Claim
16 words
A method according to claim 1 wherein the electrodes are separated by less than 500 μm.
Claim 5
Dependent Claim
64 words
A method according to claim 1 wherein the redox species is a mediator and the concentration of the reduced or oxidized form of the mediator is indicative of the concentration of an analyte and wherein a measure of the diffusion coefficient of the reduced or oxidized form of the mediator is determined as a precursor to the determination of the concentration of the analyte.
Claim 6
Dependent Claim
54 words
A method according to claim 1 wherein the steady state current is estimated by approximating an initial value for the steady state current, measuring a discrepancy between measured current versus time data and a theoretical curve, and using the degree of discrepancy, if any, to obtain a better estimate of the steady state current.
Claim 7
Dependent Claim
13 words
A method according to claim 1 wherein the redox species is an analyte.
Claim 8
Dependent Claim
12 words
A method according to claim 1 wherein the redox is a mediator.
Claim 9
Dependent Claim
16 words
A method according to claim 1 wherein the electrochemical cell additionally comprises a separate reference electrode.
Claim 10
Dependent Claim
26 words
A method according to claim 1 wherein the spacing between the electrodes is selected such what the steady state current is achieved within a desired time.
Claim 11
Dependent Claim
12 words
A method according to claim 1 when used for determining haematocrit level.
Claim 12
Dependent Claim
16 words
A method according to claim 1 when used to determine the concentration of glucose in blood.
Claim 13
Dependent Claim
109 words
Apparatus comprising a porous membrane, a working electrode on one side of the membrane, a counter electrode on the other side of the membrane, said electrodes together with a zone of the membrane therebetween defining an electrochemical cell, and wherein the membrane extends laterally from the cell to a sample deposition area spaced apart from the cell zone by a distance greater than the thickness of the membrane, wherein the distamce is sufficient so that when blood is placed on the sample deposition area, a plasma front diffuses laterally towards the cell zone in advance of the red cells, filling the cell area with plasma substantially free of hematocrit.
Claim 14
Dependent Claim
109 words
Apparatus comprising a porous membrane, a working electrode on one side of the membrane, a counter electrode on the other side of the membrane, said electrodes together with a zone of the membrane therebetween defining an electrochemical cell, and wherein the membrane extends laterally from the cell to a sample deposition area spaced apart from the cell zone by a distance greater than the thickness of the membrane, wherein the distamce is sufficient so that when blood is placed on the sample deposition area, a plasma front diffuses laterally towards the cell zone in advance of the red cells, filling the cell area with plasma substantially free of hematocrit.
Claim 15
Dependent Claim
12 words
Apparatus according to claim 12 wherein the electrochemical cell contains a reagent.
Claim 16
Dependent Claim
12 words
Apparatus according to claim 12 wherein the electrochemical cell contains a mediator.
Claim 17
Dependent Claim
20 words
Apparatus according to claim 12 wherein the membrane contains an enzyme intermediate the electrochemical cell and the sample deposition area.
Claim 18
Dependent Claim
18 words
Apparatus according to claim 12 further comprising a pH buffer in the vicinity of the sample deposition area.
Claim 19
Dependent Claim
17 words
Apparatus according to claim 12 further comprising a pH buffer in the vicinity of the working electrode.
Claim 20
Dependent Claim
36 words
Apparatus according to claim 12 comprising a second electrochemical cell zone of the membrane defined by a second working electrode anda second counter/reference electrode on the opposite side of the membrane from the second working electrode.
Claim 21
Dependent Claim
25 words
Apparatus according to claim 18 wherein the second electrochemical cell zone is situated intermediate the first cell zone and the sample deposition or target area.
Claim 22
Dependent Claim
17 words
Apparatus according to claim 12 wherein the uncompressed membrane has a thickness of less than 500 μm.
Claim 23
Dependent Claim
26 words
Apparatus according to claim 12 wherein the working electrode is a metal selected from the group comprising gold, silver, platinum, palladium, iridium, lead and alloys thereof.
Claim 24
Dependent Claim
15 words
Apparatus according to claim 12 for use in measuring the concentration of glucose in blood.
Claim 25
Dependent Claim
65 words
Apparatus for determining the concentration of a redox species in an electrochemical cell comprising: a hollow electrochemical cell having a working electrode and a counter or counter/reference electrode, means for applying an electric potential difference between said electrodes, means for measuring the change in current with time, and characterised in that the working electrode is spaced from the counter electrode by less than 500 μm.
Claim 26
Dependent Claim
65 words
Apparatus for determining the concentration of a redox species in an electrochemical cell comprising: a hollow electrochemical cell having a working electrode and a counter or counter/reference electrode, means for applying an electric potential difference between said electrodes, means for measuring the change in current with time, and characterised in that the working electrode is spaced from the counter electrode by less than 500 μm.
Claim 27
Dependent Claim
16 words
An electrochemical cell according to claim 23 wherein the electrodes are spaced from 100-200 μm apart.
Claim 28
Dependent Claim
14 words
An electrochemical cell according to claim 23 wherein the electrodes are facing one another.
Claim 29
Dependent Claim
15 words
An electrochemical cell according to claim 23 wherein the electrodes are of substantially corresponding area.
Claim 30
Dependent Claim
19 words
An electrochemical cell according to claim 23 comprising a working electrode, a counter electrode and a separate reference electrode.
Claim 31
Dependent Claim
17 words
An electrochemical cell according to claim 23 having an effective cell volume of less than 1.5 microlitres.
Claim 32
Dependent Claim
15 words
Apparatus according to claim 23 for use in measuring the concentration of glucose in blood.
Claim 33
Dependent Claim
13 words
The apparatus according to claim 23 , wherein the working electrode is preformed.
Claim 34
Dependent Claim
14 words
The apparatus according to claim 23 , wherein the working electrode comprises a non-metal.
Claim 35
Dependent Claim
26 words
The apparatus according to claim 31 , wherein the non-metal is selected from the group consisting of graphite, carbon mixed with a binder, and carbon-filled plastic.
Claim 36
Dependent Claim
15 words
The apparatus according to claim 23 , wherein the counter or counter/reference electrode is preformed.
Claim 37
Dependent Claim
31 words
The apparatus according to claim 23 , wherein the counter or counter/reference electrode comprises a metal selected from the group consisting of gold, silver, platinum, palladium, iridium, lead and alloys thereof.
Claim 38
Dependent Claim
16 words
The apparatus according to claim 23 , wherein the counter or counter/reference electrode comprises a non-metal.
Claim 39
Dependent Claim
26 words
The apparatus according to claim 35 , wherein the non-metal is selected from the group consisting of graphite, carbon mixed with a binder, and carbon-filled plastic.
Claim 40
Dependent Claim
16 words
The apparatus according to claim 23 , wherein the counter or counter/reference electrode comprises silver halide.
Claim 41
Dependent Claim
34 words
The apparatus according to claim 23 , wherein the counter or counter/reference electrode comprises silver, and wherein the reduced or oxidized fonn of the redox species is contained within a sample comprising chloride ions.
Claim 42
Dependent Claim
17 words
The apparatus according to claim 23 , wherein the hollow electrochemical cell has at least one wall.
Claim 43
Dependent Claim
13 words
The apparatus according to claim 39 , wherein the wall comprises a polymer.
Claim 44
Dependent Claim
21 words
The apparatus according to claim 23 , wherein the electrodes are spaced apart by about 20 μm to about 400 μm.
Claim 45
Dependent Claim
21 words
The apparatus according to claim 41 , wherein the electrodes are spaced apart by about 20 μm to about 200 μm.
Claim 46
Dependent Claim
21 words
The apparatus according to claim 42 , wherein the electrodes are spaced apart by about 100 μm to about 200 m.
Claim 47
Dependent Claim
21 words
The apparatus according to claim 23 , wherein the electrodes are spaced apart by about 10 μm to about 200 μm.
Claim 48
Dependent Claim
21 words
The apparatus according to claim 44 , wherein the electrodes are spaced apart by about 60 μm to about 120 μm.
Claim 49
Dependent Claim
16 words
The apparatus according to claim 23 , wherein the working electrode is about 60 μm thick.
Claim 50
Dependent Claim
18 words
The apparatus according to claim 23 , wherein the counter or counter/refercnce electrode is about 60 μm thick.
Claim 51
Dependent Claim
15 words
The apparatus according to claim 23 , wherein the electrochemical cell further comprises a mediator.
Claim 52
Dependent Claim
15 words
The apparatus according to claim 23 , wherein the electrochemical cell further comprises a reagent.
Claim 53
Dependent Claim
14 words
The apparatus according to claim 49 , wherein the reagent comprises glucose oxidase dehydrogenase.
Claim 54
Dependent Claim
23 words
The apparatus according to claim 23 , wherein the working electrode has a width of from about 1 μm to about 5 μm.
Claim 55
Dependent Claim
23 words
The apparatus according to claim 23 , wherein the counter/reference electrode has a width of from about 1 μm to about 5 μm.
Claim 56
Dependent Claim
22 words
The apparatus of claim 23 , wherein the working electrode and the counter or counter/reference electrode are substantially parallel and substantially opposed.
Claim 57
Dependent Claim
17 words
The apparatus according to claim 23 , wherein the hollow electrochemical cell further comprises a pH buffer.
Claim 58
Dependent Claim
34 words
The apparatus according to claim 23 , wherein the redox species is a mediator and a concentration of a reduced or oxidized formi of the mediator is indicative of a concentration of an analyte.
Claim 59
Dependent Claim
12 words
The apparatus according to claim 55 , wherein the analyte comprises glucose.
Claim 60
Dependent Claim
19 words
The apparatus of claim 23 , further comprising a glucose sensor, wherein the glucose sensor comprises the electrochemical cell.
Claim 61
Dependent Claim
21 words
The apparatus of claim 57 , wherein the electrochemical cell has an effective cell volume of less than about 1.5 microliters.
Claim 62
Dependent Claim
20 words
The apparatus of claim 57 , wherein the electrodes are spaced apart by about 20 μm to about 200 μm.
Claim 63
Dependent Claim
14 words
The apparatus of claim 57 , wherein the electrochemical cell further comprises a mediator.
Claim 64
Dependent Claim
14 words
The apparatus of claim 57 , wherein the electrochemical cell further comprises a reagent.
Claim 65
Dependent Claim
13 words
The apparatus of claim 61 , wherein the reagent comprises glucose oxidase dehydrogenase.
Claim 66
Dependent Claim
15 words
The apparatus of claim 57 , wherein the electrochemical cell further comprises a pH buffer.
Claim 67
Dependent Claim
22 words
The apparatus of claim 57 , wherein the working electrode and the counter or counter/reference electrode are substantially parallel and substantially opposed.
Claim 68
Dependent Claim
35 words
A hollow electrochemical cell comprising a working electrode, a counter electrode and an opening for admitting an analyte to the cell, the working electrode being spaced from the counter electrode by less than 500 μm.
Claim 69
Dependent Claim
35 words
A hollow electrochemical cell comprising a working electrode, a counter electrode and an opening for admitting an analyte to the cell, the working electrode being spaced from the counter electrode by less than 500 μm.
Claim 70
Dependent Claim
16 words
An electrochemical cell according to claim 65 wherein the electrodes are spaced from 100-200 μm apart.
Claim 71
Dependent Claim
14 words
An electrochemical cell according to claim 65 wherein the electrodes are facing one another.
Claim 72
Dependent Claim
15 words
An electrochemical cell according to claim 65 wherein the electrodes are of substantially corresponding area.
Claim 73
Dependent Claim
19 words
An electrochemical cell according to claim 65 comprising a working electrode, a counter electrode and a separate reference electrode.
Claim 74
Dependent Claim
17 words
An electrochemical cell according to claim 65 having an effective cell volume of less than 1.5 microlitres.
Claim 75
Dependent Claim
15 words
Apparatus according to claim 65 for use in measuring the concentration of glucose in blood.
Claim 76
Dependent Claim
15 words
The hollow electrochemical cell according to claim 65 , wherein the working electrode is preformed.
Claim 77
Dependent Claim
16 words
The hollow electrochemical cell according to claim 65 , wherein the working electrode comprises a non-metal.
Claim 78
Dependent Claim
28 words
The hollow electrochemical cell according to claim 73 , wherein the nonmetal is selected from the group consisting of graphite, carbon mixed with a binder, and carbon-filled plastic.
Claim 79
Dependent Claim
15 words
The hollow electrochemical cell according to claim 65 , wherein the counter electrode is prefonned.
Claim 80
Dependent Claim
31 words
The hollow electrochemical cell according to claim 65 , wherein the counter electrode comprises a metal selected from the group consisting of gold, silver, platinum, palladium, iridium, lead and alloys thereof.
Claim 81
Dependent Claim
16 words
The hollow electrochemical cell according to claim 65 , wherein the counter electrode comprises a non-metal.
Claim 82
Dependent Claim
28 words
The hollow electrochemical cell accoirding to claim 77 , wherein the nonmetal is selected from the group consisting of graphite, carbon mixed with a binder, and carbonfilled plastic.
Claim 83
Dependent Claim
16 words
The hollow electrochemical cell according to claim 65 , wherein the counter electrode comprises silver halide.
Claim 84
Dependent Claim
25 words
The hollow electrochemical cell according to claim 65 , further comprising a redox species capable of existing in a reduced form or an oxidized fonn.
Claim 85
Dependent Claim
36 words
The hollow electrochemical cell according to claim 80 , wherein the redox species is a mediator and a concentration of the reduced or oxidized form of the mediator is indicative of a concentration of an analyte.
Claim 86
Dependent Claim
14 words
The hollow electrochemical cell according to claim 81 , wherein the analyte comprises glucose.
Claim 87
Dependent Claim
34 words
The hollow electrochemical cell according to claim 80 , wherein the counter electrode comprises silver, and wherein the reduced or oxidized form of the redox species is contained within a sample comprising chloride ions.
Claim 88
Dependent Claim
26 words
The hollow electrochemical cell according to claim 80 , wherein the redox species is selected from the group consisting of chlorine, iron, lead, cadmium, and copper.
Claim 89
Dependent Claim
19 words
The hollow electrochemical cell aci.ording to claim 65 , wherein the hollow clectrochemical cell has at least one wall.
Claim 90
Dependent Claim
15 words
The hollow electrochemical cell according to claim 85 , wherein the wall comprises a polymer.
Claim 91
Dependent Claim
23 words
The hollow electrochemical cell according to claim 65 , wherein the electrodes are spaced apart by about 20 μm to about 400 μm.
Claim 92
Dependent Claim
23 words
The hollow electrochemical cell according to claim 87 , wherein the electrodes arc spaced apart by about 20 μm to about 200 μm.
Claim 93
Dependent Claim
23 words
The hollow electrochemical cell according to claim 88 , wherein the electrodes are spaced apart by about 100 μm to about 200 μm.
Claim 94
Dependent Claim
23 words
The hollow electrochemical cell according to claim 65 , wherein the electrodes are spaced apart by about 10 μm to about 200 μm.
Claim 95
Dependent Claim
23 words
The hollow electrochemical cell according to claim 90 , wherein the electrodes are spaced apart by about 60 μm to about 120 μm.
Claim 96
Dependent Claim
18 words
The hollow electrochemical cell according to claim 65 , wherein the working electrode is about 60 μm thick.
Claim 97
Dependent Claim
18 words
The hollow electrochemical cell according to claim 65 , wherein the counter electrode is about 60 μm thick.
Claim 98
Dependent Claim
17 words
The hollow electrochemical cell according to claim 65 , wherein the electrochemical cell further comprises a mediator.
Claim 99
Dependent Claim
17 words
The hollow electrochemical cell according to claim 65 , wherein the electrochemical cell further comprises a reagent.
Claim 100
Dependent Claim
16 words
The hollow electrochemical cell according to claim 95 , wherein the reagent comprises glucose oxidase dehydrogenase.
Claim 101
Dependent Claim
23 words
The hollow electrochemical cell according to claim 65 , wherein the working electrode has a width of from 1 mm to 5 mm.
Claim 102
Dependent Claim
23 words
The hollow electrochemical cell according to claim 65 , wherein the counter electrode has a width of from 1 mm to 5 mm.
Claim 103
Dependent Claim
21 words
The electrochemical cell of claim 65 , wherein the working electrode and the counter electrode are substantially parallel and substantially opposed.
Claim 104
Dependent Claim
18 words
The hollow electrochemical cell according to claim 65 , wherein the electrochemical cell further comprises a pH buffer.
Claim 105
Dependent Claim
13 words
A glucose sensor comprising the hollow electrochemical cell according to claim 65 .
Claim 106
Dependent Claim
22 words
The glucose sensor of claim 101 , wherein the electrochemical cell has an effective cell volume of less than about 1.5 microliters.
Claim 107
Dependent Claim
21 words
The glucose sensor of claim 101 , wherein the electrodes are spaced apart by about 20 μm to about 200 μm.
Claim 108
Dependent Claim
15 words
The glucose sensor of claim 101 , wherein the electrochemical cell further comprises a mediator.
Claim 109
Dependent Claim
15 words
The glucose sensor of claim 101 , wherein the electrochemical cell further comprises a reagent.
Claim 110
Dependent Claim
14 words
The glucose sensor of claim 105 , wherein the reagent comprises glucose oxidase dehydrogenase.
Claim 111
Dependent Claim
16 words
The glucose sensor of claim 101 , wherein the electrochemical cell flirther comprises a pH buffer.
Claim 112
Dependent Claim
21 words
The glucose sensor of claim 101 , wherein the working electrode and the counter electrode are substantially parallel and substantially opposed.
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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) | 2004-09-03 | 2005-03-05 | 2005-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-09-03 | 2009-03-05 | 2009-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-09-03 | 2013-03-05 | 2013-09-04 | $7700.00 | Window Closed / Lapsed |