Method for ascertaining interferants in small liquid samples in an automated clinical analyzer

• US 7,477,997 B2
• Filed: 12/19/2005
• Issued: 01/13/2009
• Est. Priority Date: 12/19/2005
• Status: Active Grant

• Current Assignee: Siemens Healthcare Diagnostics Incorporated (Siemens AG)
• Original Assignee: Siemens Healthcare Diagnostics Incorporated (Siemens AG)
• Inventors: Kaplit, Michael
• Primary Examiner(s): Cosimano; Edward R
• Application Number:
  US11/311,532
• Publication Number:
  US 20070143063A1
• Time in Patent Office: 1,121 Days
• Field of Search: 702/114, 702/1, 702/45, 702/50, 702/55, 702/127, 702/189, 73/34, 73/530.1, 731/95, 731/98, 731/99, 732/90.R, 738/61, 738/63, 738/630.1, 738/630.2, 738/64, 738/640.1, 738/641.1, 738/641.6, 221/9, 221/10, 222/1, 222/14, 222/21, 222/52, 222/55, 222/64, 436/43, 436/50, 436/54, 700/90, 700/231, 700/240
• US Class Current: 702/55
• CPC Class Codes: B01L 2200/146 Employing pressure sensors
• CPC Class Codes: B01L 2400/0487 fluid pressure, pneumatics
• CPC Class Codes: B01L 3/021 Pipettes, i.e. with only one conduit for withdrawing and redistributing liquids
• CPC Class Codes: G01N 35/1016 Control of the volume dispensed or introduced
• CPC Class Codes: Y10T 436/11 Automated chemical analysis
• CPC Class Codes: Y10T 436/119163 with aspirator of claimed structure

Abstract

A liquid aspiration method which includes a method for determining the quality of the aspirated sample through mathematical analysis of the standard deviation of the residuals of the linear regression analysis of the aspiration pressure profile generated between the onset of actual aspiration and the end of actual aspiration and comparison of the results with predetermined known values.

Claims

1. A method for verifying that an aspiration process for aspirating a liquid between a pipette and a container is free of the adverse affects of clots in the liquid or of an insufficient liquid volume by:

(1) determining the actual profile of an aspiration pressure curve for a pipette used in the aspiration process;

(2) determining a mathematical representation of the determined actual profile of the aspiration pressure curve;

(3) using numerical analysis to determine whether or not the difference between the actual profile of the aspiration pressure curve and the mathematical representation of the actual profile of an aspiration pressure curve is less than the standard deviation of the residuals of linear regression analysis of an aspiration pressure curve measured for either;

(a) a sample known to have clots;

or

(b) a sample known to be less than a desired aspiration volume; and

,

(4) using the results of the numerical analysis to confirm that the aspiration process has been performed using a liquid that is free of adverse affects.

2. A method for verifying that an aspiration process for aspirating a liquid between a pipette and a container is free of the adverse affects of clots in the liquid or of an insufficient liquid volume by:

(1) determining the actual profile of an aspiration pressure curve for a pipette used in the aspiration process between the onset of actual aspiration and the end of actual aspiration;

(2) confirming that the difference in aspiration pressure between the onset of actual aspiration and the end of actual aspiration falls either within or outside of a specific range of aspiration pressures;

(3) determining a mathematical representation of the actual profile of an aspiration pressure curve by performing a liner regression analysis on the actual profile of the aspiration pressure curve when the difference in aspiration pressure between the onset of actual aspiration and the end of actual aspiration falls within the specific range of aspiration pressures;

(4) using numerical analysis to determine whether or not the difference between the actual profile of the aspiration pressure curve and the mathematical representation of the actual profile of the aspiration pressure curve is less than the standard deviation of the residuals of linear regression analysis of an aspiration pressure curve measured for either a sample known to have clots or a sample known to be less than a desired aspiration volume; and

(5) using the results of the numerical analysis to confirm that the aspiration process has been performed using a liquid that is free of adverse affects.

3. A method for verifying that an aspiration process for aspirating a liquid between a pipette and a container is free of the adverse affects of clots in the liquid or of an insufficient liquid volume by:

(1) determining the actual profile of an aspiration pressure curve for a pipette used in the aspiration process between the onset of actual aspiration and the end of actual aspiration;

(2) determining that the difference in aspiration pressure between the onset of actual aspiration and the end of actual aspiration falls either within or outside of a specific range of aspiration pressures;

(3) determining a mathematical representation of the actual profile of the aspiration pressure curve by performing a liner regression analysis on the actual profile of the aspiration pressure curve when the difference in aspiration pressure between the onset of actual aspiration and the end of actual aspiration falls with in the specific range of aspiration pressures;

(4) confirming that the difference in aspiration pressure between the onset of actual aspiration and the end of actual aspiration falls within the range of aspiration pressures defined by;

(a) the aspiration pressure for the onset of actual aspiration for a sample of liquid distilled water and a sample of a liquid mixture of water and glycerol; and

,

(b) the aspiration pressure for the end of actual aspiration for a sample of liquid distilled water and a sample of a liquid mixture of water and glycerol; and

,

(5) using the results of whether the difference in aspiration pressures falls within the defined range of aspiration pressures in order to confirm that the aspiration process has been performed using a liquid that is free of adverse affects.