Calibration concept for amperometric creatinine sensor correcting for endogenous modulators

Patent metadata

Field	Value
Publication number	US-11209382-B2
Application number	US-201515536910-A
Country	US
Kind code	B2
Filing date	Dec 14, 2015
Priority date	Dec 18, 2014
Publication date	Dec 28, 2021
Grant date	Dec 28, 2021

Abstract

A method of calibrating a device for measuring the concentration of creatinine in a sample including one or more enzyme modulators, the method comprising: determining sensitivities of the device for each of two or more calibration solutions, wherein each calibration solution has a different amount of enzyme modulator; determining a degree of modulation for each of the two or more calibration solutions; determining a degree of modulation for a sample to be measured; and calculating the sensitivity of the device for the sample, wherein said calculating comprises modifying the sensitivity of one of the two or more calibration solutions by a function comprising the determined degrees of modulation.

First claim

The invention claimed is:

1. A method for calibrating device sensitivity of an enzymatic amperometric device for measuring a concentration of creatinine and/or creatine in a sample comprising one or more enzyme modulators, wherein said device sensitivity is the sensitivity of the device to the sample, the method comprising:
providing an enzyme amperometric device;
providing two or more calibration solutions wherein the two or more calibration solutions comprise creatinine and/or creatine;
measuring device output for the two or more calibration solutions;
determining calibration sensitivities of the device to each of the two or more calibration solutions by calculating a ratio between the output of the device in each of the two or more calibration solutions and a known concentration of creatinine and/or creatine in each of the two or more calibration solutions, wherein each calibration solution has a different amount of enzyme modulator;
determining a degree of modulation for each of the two or more calibration solutions by estimating enzyme modulation based on the amounts of enzyme modulators in each of the two or more calibration solutions;
determining a degree of modulation for the sample to be measured based on the amounts of enzyme modulators in the sample;
calculating the device sensitivity wherein said calculating comprises adjusting the calibration sensitivity of the device to one of the two or more calibration solutions by a factor, and
calibrating the device based on the calculated device sensitivity;
wherein the factor is a function of the determined degree of modulation of the sample and of one of the two or more calibration solutions, and
wherein the calibration sensitivity that is adjusted is the calibration sensitivity of the one or more calibration solutions that has a degree of enzyme modulation closest to the degree of enzyme modulation of the sample.

2. The method of claim 1 , wherein the one or more enzyme modulators include an acid or an alkali or a salt thereof.

3. The method of claim 1 , wherein the one or more enzyme modulators comprise one or more of bicarbonate, acetate, formate, Ca 2+ , Zn 2+ , and pH.

4. The method of claim 1 , wherein said determining a degree of modulation for each of the calibration solutions comprises receiving a value of said degree of modulation.

5. The method of claim 1 , wherein the device is a creatine and/or creatinine sensor, and wherein the device further comprises a membrane covering the device and facing the sample and said function further comprises a ratio between enzyme activity and permeability of the sensor.

6. The method of claim 1 , wherein one of the two or more calibration solutions has a level of enzyme modulation and another calibration solution has a higher level of enzyme modulation.

7. The method of claim 1 , wherein one of the two or more calibration solutions has a level of enzyme modulation.

8. The method of claim 1 , wherein the device is a creatine and/or creatinine sensor.

9. A computer readable medium comprising instructions which when executed by one or more processors of an electronic device, cause the electronic device to operate in accordance with the method as claimed in clam 1 .

10. An electronic device comprising:
one or more processors; and
memory comprising instructions which when executed by one or more of the one or more processors cause the electronic device to operate in accordance with the method claimed in claim 1 .

Assignees

• Radiometer Medical Aps

Inventors

• Hansen Thomas Steen
• Kjaer Thomas
• Nygaard Thomas Pedersen

Classifications

• G01N33/70

  involving creatine or creatinine · CPC title

• C12Y105/03001

  Sarcosine oxidase (1.5.3.1) · CPC title

• C12Q1/005

  involving specific analytes or enzymes (including groups of enzymes, e.g. oxydases; C12Q1/004 takes precedence) · CPC title

• C12Q1/002

  Electrode membranes · CPC title

• G01N27/3274 Primary

  Corrective measures, e.g. error detection, compensation for temperature or hematocrit, calibration (coding of calibration information G01N33/48771) · CPC title