Method for quality control of an analyzing system

• US 6,037,178 A
• Filed: 07/11/1996
• Issued: 03/14/2000
• Est. Priority Date: 07/17/1995
• Status: Expired due to Fees

• Current Assignee: Avl Medical Instruments AG (Roche Holding AG)
• Original Assignee: Avl Medical Instruments AG (Roche Holding AG)
• Inventors: Leiner, Marco Jean-Pierre, Tusa, James K.
• Primary Examiner(s): Feisee, Lila
• Assistant Examiner(s): PAK, MICHAEL D
• Application Number:
  US08/678,101
• Time in Patent Office: 1,342 Days
• Field of Search: 436/50, 436/465, 422/68.1
• US Class Current: 436/50
• CPC Class Codes: G01N 33/492 Determining multiple analytes
• CPC Class Codes: Y10T 436/115831 Condition or time responsive

Abstract

Quality control of an analyzing system that includes a portable analyzer with insertable single-use cartridges whose sample chamber contains optical and/or electrochemical sensors is accomplished by bringing the sensors in the single-use cartridge into contact, or are in contact with, a calibrating and/or conditioning medium, the calibrating and/or conditioning medium exhibiting chemical and/or physical parameters which influence the characteristic of at least one of the sensors. Just before a sample is measured, the sensors are contacted with a quality control liquid which is identical with the calibrating and/or conditioning medium within a predetermined desired range of accuracy for the sample components to be measured, as regards the chemical and/or physical parameters influencing the characteristic of at least one sensor during calibration and/or conditioning. The instantaneous control values obtained on the basis of the calibration values are subsequently compared to known target control values.

Claims

1. Method for quality control of an analyzing system consisting of a portable analyzer with insertable single-use cartridges whose sample chamber contains at least one optical and/or electrochemical ion sensor selected from the group consisting of pH, Li⁺, K⁺, Na⁺, Mg⁺⁺, Ca⁺⁺ and Cl^- sensors and at least one optical and/or electrochemical gas sensor selected from the group consisting of O₂ and CO₂ sensors, wherein said sensors are stored in contact with a conditioning liquid, comprising the steps of:

a) reading production-inherent characteristics of the individual ion and gas sensors into the analyzer, or using already stored characteristics, and inserting the cartridge into the analyzer;

b) replacing the conditioning liquid present in the sample chamber by a gaseous calibrating medium, wherein residues of the conditioning liquid remaining in ion-permeable layers of the ion sensors are treated with the gaseous calibrating medium to thereby form a calibrating liquid, and wherein the gaseous calibrating medium contacts the gas sensors;

c) simultaneously detecting calibration signals of the ion and gas sensors;

d) contacting the ion and gas sensors with a quality control liquid, which, as regards those chemical and/or physical parameters that influence the characteristic of at least one ion or gas sensor during calibration or conditioning, is identical with the conditioning liquid within a predetermined range of accuracy for the sample components to be measured;

e) simultaneously detecting control signals of the sensors;

f) determining instantaneous control values for the individual sensors with the use of the characteristics entered or stored in the analyzer and the calibration and control signals detected in steps c) and e);

g) comparing the instantaneous control values with known target control values; and

h) subsequent to the process of quality control, employing the same cartridge for sample measurement, if the instantaneous control values are identical with the target control values within the predetermined range of accuracy.

2. Method according to claim 1, wherein in step d) the sensors are contacted immediately prior to sample measurement with a quality control liquid whose CO₂ /pH equilibrium curve and pH₂ O in a measuring range and at a given measuring temperature are identical with the respective values of the conditioning liquid within the predetermined range of accuracy for the sample components to be measured.

3. Method according to claim 2, wherein the ionic strength of the quality control liquid is identical with that of the conditioning liquid in the measuring range and at a given pH, within the predetermined range of accuracy for the sample components to be measured.

4. Method according to claim 2, wherein the osmotic pressure of the quality control liquid is identical with that of the conditioning liquid within the predetermined range of accuracy for the sample components to be measured.

5. Method for quality control of an analyzing system consisting of a portable analyzer with insertable single-use cartridges whose sample chamber contains at least one optical and/or electrochemical ion sensor selected from the group consisting of pH, Li⁺, K⁺, Na⁺, Mg⁺⁺, Ca⁺⁺ and Cl^- sensors, wherein said sensors are stored in contact with a conditioning liquid, comprising the steps of:

a) reading production-inherent characteristics of the individual ion sensors into the analyzer, or using already stored characteristics, and inserting the cartridge into the analyzer;

b) replacing the conditioning liquid present in the sample chamber by a gaseous calibrating medium, wherein any residues of the conditioning liquid remaining in ion-permeable layers of the ion sensors are treated with the gaseous calibrating medium to form a calibrating liquid;

c) simultaneously detecting calibration signals of the ion sensors;

d) contacting the ion sensors with a quality control liquid, which, as regards those chemical and/or physical parameters that influence the characteristic of at least one sensor during calibration or conditioning, is identical with the conditioning liquid within a predetermined range of accuracy for the sample components to be measured;

e) simultaneously detecting control signals of the sensors;

f) determining instantaneous control values for the individual sensors with the use of the characteristics entered or stored in the analyzer and the calibration and control signals detected in steps c) and e);

g) comparing the instantaneous control values with known target control values; and

h) subsequent to the process of quality control, employing the same cartridge for sample measurement, if the instantaneous control values are identical with the target control values within the predetermined range of accuracy.

6. Method according to claim 5, wherein in step d) the sensors are contacted immediately prior to sample measurement with a quality control liquid whose CO₂ /pH equilibrium curve and pH₂ O in a measuring range and at a given measuring temperature are identical with the respective values of the conditioning liquid within the predetermined range of accuracy for the sample components to be measured.

7. Method according to claim 6, wherein the ionic strength of the quality control liquid is identical with that of the conditioning liquid in a predetermined measuring range and at a given pH, within the predetermined range of accuracy for the sample components to be measured.

8. Method for quality control of an analyzing system consisting of a portable analyzer with insertable single-use cartridges whose sample chamber contains optical and/or electrochemical sensors, wherein said sensors are dry-stored comprising the steps of:

a) reading production-inherent characteristics of the individual sensors into the analyzer, or using already stored characteristics, and inserting the cartridge into the analyzer;

b) subjecting the sensors to a calibrating liquid;

c) simultaneously detecting calibration signals of the sensors, taking into account the time lapse between the primary contact of the sensors and the calibrating liquid and the detection of the calibration signals;

d) contacting the sensors with a quality control liquid, which, as regards those chemical and/or physical parameters that influence the characteristic of at least one sensor during calibration, is identical with the calibrating liquid within a predetermined range of accuracy for sample components to be measured;

e) simultaneously detecting control signals of the sensors taking into account the time lapse between the primary contact of the sensors and the calibrating liquid and the detection of the control signals;

f) determining instantaneous control values for the individual sensors from the characteristics entered or stored in the analyzer, and the calibration and control signals detected in steps c) and e);

g) comparing the instantaneous control values with known target control values; and

h) subsequent to the process of quality control, employing the same cartridge for sample measurement, if the instantaneous control values are identical with the target control values within the predetermined range of accuracy.

9. Method according to claim 8, wherein in step d) the sensors are contacted immediately prior to sample measurement with a quality control liquid whose CO₂ /pH equilibrium curve and pH₂ O in a measuring range and at a given measuring temperature are identical with the respective values of the calibrating liquid of step b) within the predetermined range of accuracy for the sample components to be measured.

10. Method according to claim 9, wherein the ionic strength of the quality control liquid is identical with that of the calibrating liquid in the measuring range and at a given pH, within the predetermined range of accuracy for the sample components to be measured.

11. Method according to claim 9, wherein the osmotic pressure of the quality control liquid is identical with that of the calibrating liquid within the predetermined range of accuracy for the sample components to be measured.

12. Method according to claim 8, wherein in step d) a gas of known composition for the purpose of separating the calibrating liquid from the quality control liquid is added.