Detecting a transient error in a body fluid sample

• US 9,904,890 B2
• Filed: 03/13/2015
• Issued: 02/27/2018
• Est. Priority Date: 03/13/2015
• Status: Active Grant

• Current Assignee: Instrumentation Lab Co (Instrumentation Lab)
• Original Assignee: Instrumentation Lab Co (Instrumentation Lab)
• Inventors: Mansouri, Sohrab, Cervera, Jose Maria
• Primary Examiner(s): CHEN, ALAN S
• Application Number:
  US14/657,254
• Publication Number:
  US 20160267389A1
• Time in Patent Office: 1,082 Days
• Field of Search: None
• CPC Class Codes: G01N 35/00613 Quality control
• CPC Class Codes: G06F 17/18 for evaluating statistical data , e.g. average values, frequency distributions, probability functions, regression analysis forecasting specially adapted for a specific administrative, business or logistic context G06Q10/04
• CPC Class Codes: G06N 7/00 Computing arrangements based on specific mathematical models

Abstract

An approach for detecting a transient error in a body fluid sample based on the shape of a response curve of a sensor is provided. The response curve is represented by an equation including at least one coefficient describing a curvature or slope of the response curve. The approach includes comparing the coefficient to a range of coefficients which includes coefficients of response curves corresponding to known analyte concentrations. The approach further includes detecting a transient error based on the comparison. In some examples of the approach, the comparison and detection are performed by a processing transient error detector executing computer readable instructions embodied in a non-transitory computer-readable medium. Other examples of the approach determine a concentration of the analyte based on the equation. Advantageously, various examples of the approach can expedite detection of transient errors at the time of measuring and before reporting sample result.

Claims

1. A method for detecting a transient error in a body fluid sample taken from a patient, the method comprising:

in a clinical analyzer, exposing a sensor to a body fluid sample containing an analyte for determining a concentration of the analyte in the body fluid sample, wherein the sensor generates a data signal in response to being exposed to the body fluid sample;

generating a sample response curve representing the data signal;

determining coefficients of an equation representing the sample response curve;

comparing the coefficients of the equation representing the sample response curve to a predetermined range of coefficients, wherein the predetermined range of coefficients define a range of acceptable response curve shapes, the predetermined range of coefficients including coefficients of predetermined response curves corresponding to known concentrations of the analyte;

detecting a transient error in the body fluid sample based on the comparison when the coefficients of the equation representing the sample curve are outside of the predetermined range of coefficients; and

displaying a transient error notification in response to the transient error being detected.

2. The method of claim 1 wherein the equation representing the sample response curve is any one of logarithmic equation and quadratic equation.

3. The method of claim 1 wherein the comparing includes comparing a coefficient describing the curvature of the sample response curve to the range of coefficients and comparing a coefficient describing the slope of the sample response curve to a second range of coefficients different than the range of coefficients;

and

wherein the detecting includes detecting the transient error in the body fluid sample based on the comparison of the coefficient describing the curvature of the sample response curve and the comparison of the coefficient describing the slope of the sample response curve.

4. The method of claim 1 wherein the range of coefficients for a given concentration of analyte includes a mean coefficient determined from a mean of coefficients of the predetermined response curves corresponding to the given concentration of analyte;

a lower limit defined by a negative number of standard deviations from the mean coefficient; and

an upper limit defined by a positive number of standard deviations from the mean coefficient.

5. The method of claim 4 wherein an absolute value of the negative number of standard deviations from the mean coefficient and an absolute value of the positive number of standard deviations from the mean coefficient are different.

6. The method of claim 4 wherein the lower limit and the upper limit of the range of coefficients are invariant to changes in concentration of the analyte.

7. The method of claim 4 wherein at least one of the lower limit and the upper limit of the range of coefficients varies with changes in concentration of the analyte.

8. The method of claim 4 further comprising revising the range of coefficients based on the coefficient of the sample response curve corresponding to the concentration of the analyte in the body fluid sample.

9. The method of claim 1 wherein the known concentrations of the analyte are determined from at least one of previously collected body fluid samples and standardized solutions.

10. The method of claim 1 wherein the range of coefficients depends on a matrix of the body fluid sample.

11. The method of claim 1 further comprising based on a result of the detection, determining the concentration of the analyte in the body fluid sample based on the equation.

12. The method of claim 1 further comprising determining the concentration of the analyte in the body fluid sample based the equation;

and

wherein detecting the transient error includes detecting the transient error in the determined concentration of the analyte based on the comparison.

13. The method of claim 1 further comprising based on the detection, reporting to a user of the analyzer that a transient error is detected in the body fluid sample.

14. The method of claim 13 wherein the reporting includes to providing a visual alarm, an audible alarm or a combination thereof to the user.

15. The method of claim 1 further comprising based on the detection, stopping a sample measurement process including determining the concentration of the analyte.

16. The method of claim 1 further comprising based on the detection, reporting to a user of the analyzer that the body fluid sample may be compromised by a transient error;

and continuing a sample measurement process including determining the concentration of the analyte.

17. A system for detecting a transient error in a body fluid sample, the system comprising:

a sensor for determining the concentration of analyte in the body fluid sample, the sensor configured to generate a data signal in response to being exposed to the body fluid sample;

a transient error detector coupled to the sensor, the transient error detector configured to;

generate a sample response curve representing the data signal,

determine coefficients of an equation representing the sample response curve,

compare the coefficients of the equation representing the sample response curve to a predetermined range of coefficients, wherein the predetermined range of coefficients defines a range of acceptable response curve shapes, the predetermined range of coefficients including coefficients of predetermined response curves corresponding to known concentrations of the analyte and

detect a transient error in the body fluid sample based on the comparison when the coefficients of the equation representing the sample response curve are outside of the predetermined range of coefficients; and

a display coupled to the transient error detector, the display configured to display a transient error notification in response to the transient error being detected.

18. The system of claim 17 wherein the equation representing the sample response curve is any one of logarithmic equation and quadratic equation.

19. The system of claim 17 wherein the range of coefficients for a given concentration of analyte includes a mean coefficient determined from a mean of coefficients of the predetermined response curves corresponding to the given concentration of analyte;

a lower limit defined by a negative number of standard deviations from the mean coefficient; and

an upper limit defined by a positive number of standard deviations from the mean coefficient.