US5407545A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for measuring sample by enzyme electrodes
Assignee: Arkray Inc
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Filing: 1994-04-25
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Granted: 1995-04-18
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Expires: 2014-04-25
Abstract
Abstract A buffer solution is charged in a reaction container so that enzyme electrodes can be immersed in the buffer solution. Current values between the enzyme electrodes, to which a voltage is applied, are sampled at predetermined-time intervals. A decreasing curve of current is predicted on the basis of the sampled current values. A sample is injected in said buffer solution at an early time before the current between enzyme electrodes become stable, whereby oxidation reaction of a specified component of the sample is caused. A current value I 1 between enzyme electrodes is measured and simultaneously a current value T 2 on the decreasing curve is obtained at a point that a predetermined time passes from the sample injection point to obtain a current increase from the sample injection on the basis of a difference of the current values I 1 and I 2 . A quantity of the specified component of the sample is obtained on the basis of the current increase.
Inventors
- 👤 Kazunori Hirose
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 02:04
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/001
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
171 words
A method for measuring sample by enzyme electrodes comprising the following steps of: charging a buffer solution in a reaction container so that said enzyme electrodes can be immersed in said buffer solution; sampling current values between said enzyme electrodes, to which a voltage is applied, at set-time intervals; predicting a decreasing curve of current on the basis of said current values; injecting a sample in said buffer solution at an early time before said current between enzyme electrodes become stable, whereby oxidation reaction of a specified component of said sample is caused; measuring a current value I 1 between said enzyme electrodes and simultaneously obtaining a current value I 2 on said decreasing curve at a point that a set time passes from said sample injection point to obtain a current increase from said sample injection on the basis of a difference of said current values I 1 and I 2 ; and obtaining a quantity of said specified component of said sample on the basis of said current increase.
Claim 2
Independent Claim
171 words
A method for measuring sample by enzyme electrodes comprising the following steps of: charging a buffer solution in a reaction container so that said enzyme electrodes can be immersed in said buffer solution; sampling current values between said enzyme electrodes, to which a voltage is applied, at set-time intervals; predicting a decreasing curve of current on the basis of said current values; injecting a sample in said buffer solution at an early time before said current between enzyme electrodes become stable, whereby oxidation reaction of a specified component of said sample is caused; measuring a current value I 1 between said enzyme electrodes and simultaneously obtaining a current value I 2 on said decreasing curve at a point that a set time passes from said sample injection point to obtain a current increase from said sample injection on the basis of a difference of said current values I 1 and I 2 ; and obtaining a quantity of said specified component of said sample on the basis of said current increase.
Claim 3
Independent Claim
198 words
A method for measuring sample by enzyme electrodes comprising the following steps of: charging a buffer solution in a reaction container so that said enzyme electrodes can be immersed in said buffer solution; sampling current values between said enzyme electrodes, to which a voltage is applied, at set-time intervals; predicting a decreasing curve of current on the basis of said current values to obtain a differential decreasing curve by differentiating said decreasing curve; injecting a sample in said buffer solution at an early time before said current between enzyme electrodes become stable, whereby oxidation reaction of a specified component of said sample is caused; obtaining a differential reaction curve by differentiating a reaction curve of current measured under said oxidation reaction; obtaining a differential current value dI 1 on said differential reaction curve and a differential current value dI 2 on said differential decreasing curve at a peak point of said differential reaction curve to obtain a current increase from said sample injection on the basis of a difference of said differential current values dI 1 and dI 2 ; and obtaining a quantity of said specified component of said sample on the basis of said current increase.
Claim 4
Independent Claim
198 words
A method for measuring sample by enzyme electrodes comprising the following steps of: charging a buffer solution in a reaction container so that said enzyme electrodes can be immersed in said buffer solution; sampling current values between said enzyme electrodes, to which a voltage is applied, at set-time intervals; predicting a decreasing curve of current on the basis of said current values to obtain a differential decreasing curve by differentiating said decreasing curve; injecting a sample in said buffer solution at an early time before said current between enzyme electrodes become stable, whereby oxidation reaction of a specified component of said sample is caused; obtaining a differential reaction curve by differentiating a reaction curve of current measured under said oxidation reaction; obtaining a differential current value dI 1 on said differential reaction curve and a differential current value dI 2 on said differential decreasing curve at a peak point of said differential reaction curve to obtain a current increase from said sample injection on the basis of a difference of said differential current values dI 1 and dI 2 ; and obtaining a quantity of said specified component of said sample on the basis of said current increase.
Claim 5
Dependent Claim
19 words
A method according to claim 1 or 2, wherein said decreasing curve is predicted by a least square method.
Claim 6
Dependent Claim
28 words
A method according to claim 1 or 2, wherein said step of predicting a decreasing curve of current is prosecuted at every time of measurement of each sample.
Claim 7
Dependent Claim
14 words
A method according to claim 1 or 2, wherein said sample is a blood.
Claim 8
Dependent Claim
15 words
A method according to claim 1 or 2, wherein said sample is a blood serum.
Claim 9
Dependent Claim
15 words
A method according to claim 1 or 2, wherein said sample is a blood plasma.
Claim 10
Dependent Claim
14 words
A method according to claim 1 or 2, wherein said sample is a urine.
Claim 11
Dependent Claim
15 words
A method according to claim 1 or 2, wherein said specified component is a glucose.
Claim 12
Dependent Claim
16 words
A method according to claim 1 or 2, wherein said specified component is a uric acid.
Claim 13
Dependent Claim
15 words
A method according to claim 1 or 2, wherein said sample is a lactic acid.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1998-04-17 | 1998-10-17 | 1999-04-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-04-17 | 2002-10-17 | 2003-04-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-04-17 | 2006-10-17 | 2007-04-18 | $7700.00 | Window Closed / Lapsed |