Methods and systems to correct for hematocrit effects
First Claim
1. A method of correcting a glucose concentration in a glucose measurement system having a test strip and an optical reading device, the method comprising:
- determining a first glucose concentration by measuring a first reflectance at about a first wavelength proximate a surface of the test strip having a membrane impregnated with a color-producing reagent;
measuring a temperature and measuring a second reflectance at about a second wavelength;
determining a second glucose concentration with at least one equation to correct the first glucose concentration with the temperature and the second reflectance at about the second wavelength; and
displaying the second glucose concentration.
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Abstract
Described and illustrated herein are exemplary methods of operating an analyte measurement system having a meter and a test strip. Such methods may be exemplarily achieved by determining a first glucose concentration by measuring a first reflectance at about a first wavelength at a testing surface of the pad; measuring a second reflectance at about a second wavelength; formulating at least one equation to correct the first glucose concentration for temperature or hematocrit effects using the second reflectance at about the second wavelength; determining a second glucose concentration using the first glucose concentration, the second reflectance at about a second wavelength; and displaying the second glucose concentration that is corrected for temperature and hematocrit effects.
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Citations
8 Claims
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1. A method of correcting a glucose concentration in a glucose measurement system having a test strip and an optical reading device, the method comprising:
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determining a first glucose concentration by measuring a first reflectance at about a first wavelength proximate a surface of the test strip having a membrane impregnated with a color-producing reagent; measuring a temperature and measuring a second reflectance at about a second wavelength; determining a second glucose concentration with at least one equation to correct the first glucose concentration with the temperature and the second reflectance at about the second wavelength; and displaying the second glucose concentration. - View Dependent Claims (2, 6, 7, 8)
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3. A method of correcting a glucose concentration in a glucose measurement system having a test strip and an optical reading device, the method comprising:
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determining a first glucose concentration by measuring a first reflectance at about a first wavelength proximate a surface of the test strip having a membrane impregnated with a color-producing reagent; measuring a temperature and measuring a second reflectance at about a second wavelength; determining a second glucose concentration based on the temperature and the second reflectance at about the second wavelength with an equation of the form;
G2=a0+a1*G1+a2*T+a3*K/Sλ
2+a4*G1*T+a5*G1*K/Sλ
2+a6*T*K/Sλ
2+a7*(G1)2+a8*(T)2+a9*(K/Sλ
2)2+a10*(G1)3+a11*(T)3+a12*(K/Sλ
2)3+a13*G1*T*K/Sλ
2+a14*(G1)2*T+a15*(G1)2*(K/Sλ
2)+a16*G1*T2+a17*G1*(K/Sλ
2)2+a18*T*(K/Sλ
2)2+a19*T2*(K/Sλ
2)where; G2 is the second glucose concentration corrected for temperature and hematocrit effects; G1 is the first glucose concentration and is determined from the reflectance measured at about a first wavelength, λ
1;T is temperature; K/Sλ
2 comprises a value obtained with an equation of the form;
K/Sλ
2=(1−
R2)2/(2*R2)where; R2 is the second reflectance at about the second wavelength, λ
2, taken at an endpoint time; andCoefficients a0 through a19 depend on the endpoint time at which the first reflectance at about the first wavelength, λ
1, is measured; anddisplaying the second glucose concentration.
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4. A method of correcting a glucose concentration in a glucose measurement system having a test strip and an optical reading device, the method comprising:
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determining a first glucose concentration by measuring a first reflectance at about a first wavelength proximate a surface of the test strip having a membrane impregnated with a color-producing reagent; measuring a temperature and measuring a second reflectance at about a second wavelength; determining a second glucose concentration based on the temperature measurement and the second reflectance made at about the second wavelength with an equation of the form;
G2=a1*G1+a2*T+a3*K/Sλ
2+a4*G1*T+a5*G1*K/Sλ
2+a6*T*K/Sλ
2+a7*(G1)2+a8*(T)2+a9*(K/Sλ
2)2where; G2 is the second glucose concentration corrected for temperature and hematocrit effects; G1 is the first glucose concentration and is determined from the first reflectance measured at about a first wavelength, λ
1;T is temperature; K/Sλ
2 is determined with an equation of the form;
K/Sλ
2=(1−
R2)2/(2*R2)where; R2 is the second reflectance at about the second wavelength, λ
2, taken at an endpoint time; andCoefficients a1 through a6 depend on the endpoint time at which the first reflectance at first wavelength, λ
1, is measured; anddisplaying the second glucose concentration.
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5. A method of correcting a glucose concentration in a glucose measurement system having a test strip and an optical reading device, the method comprising:
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determining a first glucose concentration by measuring a first reflectance at about a first wavelength at a surface of the test strip having a membrane impregnated with a color-producing reagent; measuring a temperature and measuring a second reflectance at about a second wavelength; determining a second glucose concentration based on the second reflectance at about the second wavelength and the measured temperature with the equation of the form;
G2=a0+a1*G1+a2*T+a3*K/Sλ
2+a4*G1*K/Sλ
2+a5*G1*Twhere; G2 is the second glucose concentration corrected for temperature and hematocrit effects; G1 is the first glucose concentration and is determined from the reflectance measured at about a first wavelength, λ
1;T is temperature; K/Sλ
2 comprises a value obtained with an equation of the form;
K/Sλ
2=(1-R2)2/ (2*R2)where; R2 is the second reflectance at about the second wavelength, λ
2, taken at an endpoint time; andCoefficients a0 through a5 depend on the endpoint time at which the first reflectance at first wavelength, λ
1, is measured; anddisplaying the second glucose concentration.
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Specification