EP0922954A2
Expired / Lapsed
EP
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Method for recognizing the presence of sample fluid on a test strip by evaluating first and second derivatives
Assignee: UMM Electronics Inc
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Filing: 1998-12-03
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Granted: —
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Expires: 2018-12-03
Abstract
Abstract A method for determining the application of a sample fluid on an analyte strip using first and second derivatives. Sample fluid, such as whole blood, is applied to a reagent matrix and sensor readings, such as reflectance readings or current readings, are taken of the fluid/reagent combination. The first and second derivatives of the sensor readings are calculated. A predetermined incubation time period is begun at either a local minimum in the first derivative or a local maximum following a local minimum in the second derivative data. At the expiration of the incubation period, another sensor reading is taken which is indicative of an analyte concentration in the sample fluid (such as glucose concentration in a whole blood sample).
Inventors
- 👤 Richard A. Riedel
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 00:03
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/8483; Y; Y10; Y10T; Y10T436/00; Y10T436/14; Y10T436/142222; Y10T436/143333; Y10T436/144444
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
117 words
A method for determining a start of reaction timing for measurement of a
reaction between a sample fluid and a reagent, comprising the steps of: a) measuring the reagent at intervals prior to application of the sample
fluid to the reagent; b) applying the sample fluid to the reagent; c) measuring the reagent/sample fluid combination at intervals after
performing step (b); d) calculating a first derivative of the measurement data taken at steps (a)
and (c); e) determining a location of a local minimum in the first derivative data; f) beginning a predetermined time period at a time corresponding to the
local minimum; and g) measuring the reagent/sample fluid combination after expiration of the
predetermined time period.
Claim 2
Dependent Claim
12 words
The method of claim 1, wherein the sample fluid is whole blood.
Claim 3
Dependent Claim
29 words
The method of claim 2, wherein the reagent reacts with the whole blood
to produce a color change in proportion to an amount of glucose in the whole blood.
Claim 4
Dependent Claim
18 words
The method of claim 1, wherein step (a) comprises measuring an
amount of light reflected from the reagent.
Claim 5
Dependent Claim
22 words
The method of claim 1, wherein steps (c) and (g) comprise measuring an
amount of light reflected from the reagent/sample fluid combination.
Claim 6
Dependent Claim
18 words
The method of claim 1, wherein step (a) comprises measuring an
amount of current flowing through the reagent.
Claim 7
Dependent Claim
22 words
The method of claim 1, wherein steps (c) and (g) comprise measuring an
amount of current flowing through the reagent/sample fluid combination.
Claim 8
Dependent Claim
11 words
The method of claim 1, wherein the intervals are fixed intervals.
Claim 9
Independent Claim
121 words
A method for determining a start of reaction timing for measurement of
a reaction between a sample fluid and a reagent, comprising the steps of: a) measuring the reagent at intervals prior to application of the sample
fluid to the reagent; b) applying the sample fluid to the reagent: c) measuring the reagent/sample fluid combination at intervals after
performing step (b); d) calculating a second derivative of the measurement data taken at steps
(a) and (c); e) determining a location of a local maximum following a local minimum
in the second derivative data; f) beginning a predetermined time period at a time corresponding to the
local maximum; and g) measuring the reagent/sample fluid combination after expiration of the
predetermined time period.
Claim 10
Dependent Claim
12 words
The method of claim 9, wherein the sample fluid is whole blood.
Claim 11
Dependent Claim
29 words
The method of claim 10, wherein the reagent reacts with the whole
blood to produce a color change in proportion to an amount of glucose in the whole
blood.
Claim 12
Dependent Claim
18 words
The method of claim 9, wherein step (a) comprises measuring an
amount of light reflected from the reagent.
Claim 13
Dependent Claim
22 words
The method of claim 9, wherein steps (c) and (g) comprise measuring an
amount of light reflected from the reagent/sample fluid combination.
Claim 14
Dependent Claim
18 words
The method of claim 9, wherein step (a) comprises measuring an
amount of current flowing through the reagent.
Claim 15
Dependent Claim
22 words
The method of claim 9, wherein steps (c) and (g) comprise measuring an
amount of current flowing through the reagent/sample fluid combination.
Claim 16
Dependent Claim
11 words
The method of claim 9, wherein the intervals are fixed intervals.
References Cited (Backward Citations)
No citation records indexed.
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