Method for flushing and calibrating a sensor in a body fluid analysis system

• US 6,027,445 A
• Filed: 06/30/1998
• Issued: 02/22/2000
• Est. Priority Date: 07/17/1997
• Status: Expired due to Term

• Current Assignee: Sphere Medical Limited (Sphere Medical Holding Ltd.)
• Original Assignee: Siemens Elema AB
• Inventors: Von Bahr, Pontus
• Primary Examiner(s): WINAKUR, ERIC FRANK
• Application Number:
  US09/106,777
• Time in Patent Office: 602 Days
• Field of Search: 600/309, 204/403, 204/406, 204/409, 364/497, 422/68.1, 436/47, 436/52, 436/68
• US Class Current: 600/309
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes

Abstract

In a method for flushing and calibrating at least one sensor in a system for body fluid analysis, said system having a first container, connected to the sensor, holding a first flushing liquid, and a second container, connected to the sensor, holding a second flushing liquid, the flushing liquids having different analytic contents, a calibration measurement is performed with one of the flushing liquids before every body fluid analysis determination, with the different flushing liquids being used alternatively according to a predetermined pattern. The pattern is governed by certain criteria or a combination thereof.

Claims

1. A method for flushing and calibrating a sensor in a body fluid analysis system, the system having a first container in fluid communication with the sensor and holding a first flushing liquid, and a second container in fluid communication with the sensor and holding a second flushing liquid, the first and second flushing liquids having respectively different analytic contents, said method comprising the steps of:

(a) conducting a succession of body fluid analyses using said sensor;

(b) preceding each body fluid analysis by no more than one calibration measurement using one of said first and second flushing liquids; and

(c) alternatively using said first and second flushing liquids for said calibration measurement according to a predetermined pattern determined by at least one predetermined criterion.

2. A method as claimed in claim 1 wherein the step of alternatively using said first and second flushing liquids comprises using said second flushing liquid for every n^th calibration, n being a whole number and n≧

2, and otherwise using said first flushing liquid.

3. A method as claimed in claim 1 wherein the step of alternatively using said first and second flushing liquids comprises automatically using said second flushing liquid for a calibration measurement when said at least one predetermined criterion is present.

4. A method as claimed in claim 1 wherein the step of alternatively using said first and second flushing liquids comprises manually controlling use of said second flushing liquid when said at least one predetermined criterion is present.

5. A method as claimed in claim 1 wherein said body fluid analysis system further includes a collection unit in fluid communication with said sensor for receiving said first and second flushing liquids after usage thereof, a first pump connected between said first container and said sensor, a second pump connected between said second container and said sensor and a third pump connected between said collection unit and said sensor, and wherein steps (a) and (b) comprise:

pumping said first flushing liquid with said first pump to flush said sensor and said sensor performing a calibration measurement of said first flushing liquid, and

performing a body fluid analysis using said sensor;

and wherein step (c) comprises;

pumping said second flushing liquid with said second pump to flush said sensor,

and said sensor performing a calibration measurement of said second flushing liquid.

6. A method as claimed in claim 5 comprising the additional step of pumping the respective first and second flushing liquids with said third pump from said sensor to said collection unit.

7. A method as claimed in claim 6 comprising operating at least one of said first, second or third pumps to pump body fluid to said sensor for conducting said body fluid analysis.

8. A method as claimed in claim 7 comprising the additional steps of:

monitoring pressure and whether bubbles are present at a location between said first pump and said sensor;

monitoring pressure and whether bubbles are present at a second location between said second pump and said sensor; and

monitoring pressure and whether bubbles are present at a location between said third pump and said sensor.