Method and apparatus for calibration and testing of scientific measurement equipment

• US 8,538,727 B2
• Filed: 07/21/2010
• Issued: 09/17/2013
• Est. Priority Date: 07/21/2009
• Status: Active Grant

• Current Assignee: George S. Cembrowski
• Original Assignee: George S. Cembrowski
• Inventors: Cembrowski, George S.
• Primary Examiner(s): Kundu, Sujoy
• Assistant Examiner(s): HWANG, TIMOTHY
• Application Number:
  US12/841,055
• Publication Number:
  US 20110022343A1
• Time in Patent Office: 1,154 Days
• Field of Search: 702/179
• US Class Current: 702/179
• CPC Class Codes: G01N 2035/00653 statistical methods comparing labs or apparatuses
• CPC Class Codes: G01N 2035/0094 optimisation; experiment design
• CPC Class Codes: G01N 35/00613 Quality control
• CPC Class Codes: G16H 10/60 for patient-specific data, e.g. for electronic patient records

Abstract

Discussed herein are methods and apparatuses to produce profiles for scientific measurement equipment, and to use those profiles for various purposes in using, designing, calibrating and managing such equipment, such as to carry out critical laboratory testing. In this approach, either the analyzers'"'"' quality control data or serial patient data are numerically reduced to generate graphical precision profiles. Precision profiles for serial patient data show increased (im)precision vs time implying increased patient variation over increased time. Precision profiles for quality control data, according to one implementation, can demonstrate three different zones: 1) increased imprecision for quality control determinations that are close spaced (implies the discovery of an error condition and rapid reanalysis, 2) the usual imprecision and 3) a zone of increased imprecision which indicates either a need for a quality control analysis or re-calibration.

Claims

1. A method comprising:

operating a laboratory analyzer in order to obtain accurate measurements and test results for patients;

using the test results from the laboratory analyzer to generate a precision profile;

calibrating the laboratory analyzer by adjusting calibration inputs of the laboratory analyzer in response to information obtained from viewing the precision profiles;

wherein the information obtained includes using a computer to calculate within-patient variation including;

determining average intra-patient variations of sample results provided by the laboratory measurement equipment over a period of time, wherein the sample results are a subset of the test results;

determining an axis-intercept using a regression of the intra-patient variations versus time between sample results; and

determining the within-patient variation as a function of the axis-intercept.

2. The method of claim 1, further comprising obtaining the sample results by data-mining previous results provided by the laboratory analyzer.

3. The method of claim 2, wherein obtaining sample results includes obtaining sample results that were only provided for clinical care of a patient.

4. The method of claim 1, further comprising grouping the sample results by a time interval in which the sample results were provided, and wherein calculating the average intra-patient variation includes calculating the average intra-patient variation for each time interval.

5. The method of claim 1, further comprising removing out-lying sample results before calculating the average intra-patient variation.

6. The method of claim 5, wherein removing out-lying sample results includes removing out-lying sample results as a function of a frequency histogram and removing sample results from a repeated measurement made within a specific time period.

7. The method of claim 5, wherein removing out-lying sample results includes removing sample results from a repeated measurement made within two hours.

8. The method of claim 1, wherein calculating the within-patient variation includes using the formula:

within-patient variation=((axis-intercept)²−

(analytic variation)²)^1/2.

9. The method of claim 8, further comprising calculating the analytic variation as a function of a chemical concentration and an experimental coefficient of variation.

10. A non-transitory computer readable storage device including instructions stored thereon, the instructions, which when executed by a machine, cause the machine to perform operations comprising:

establishing a scheduled time to calibrate laboratory measurement equipment comprising;

a) calculating average intra-patient variations of sample results provided by the laboratory measurement equipment over a period of time;

b) calculating an axis-intercept using a regression of the intra-patient variations versus time between sample results; and

c) calculating the within-patient variation as a function of the axis-intercept; and

displaying an indication of the scheduled time to a user on a display device.

11. The storage device of claim 10, further comprising instructions, which when executed by the machine, cause the machine to perform operations comprising obtaining the sample results by data-mining previous results provided by the laboratory measurement equipment.

12. The storage device of claim 11, wherein the instructions for obtaining sample results include instructions for obtaining sample results that were only provided for clinical care of a patient.

13. The storage device of claim 10, further comprising instructions, which when executed by a machine, cause the machine to perform operations comprising grouping the sample results into groups of time intervals, and wherein the instructions for calculating the average intra-patient variation include instructions for calculating the average intra-patient variation for each time interval.

14. The storage device of claim 13, further comprising instructions, which when executed by the machine, cause the machine to perform operations comprising removing out-lying sample results before calculating the average intra-patient variation.

15. The storage device of claim 14, wherein the instructions for removing out-lying sample results include instructions for removing out-lying sample results as a function of a frequency histogram and removing sample results from a repeated measurement made within a specific time period of each other.

16. The storage device of claim 10, wherein the instructions for removing out-lying sample results include instructions for removing sample results from a repeated measurement made within two hours.

17. The storage device of claim 10, wherein the instructions for calculating the within-patient variation include instruction for calculating the within-patient variation using the formula:

within-patient variation=((axis-intercept)²−

(analytic variation)²)^1/2.

18. The storage device of claim 17, further comprising instructions, which when executed by the machine, cause the machine to perform operations comprising calculating the analytic variation as a function of a chemical concentration and an experimental coefficient of variation.

19. The storage device of claim 10, further comprising displaying a precision profile to the user on a display device, wherein the precision profile includes a graph of the average intra-patient variations of sample results provided by the laboratory measurement equipment over a period of time.