Blood analysis system and method for regulating same

• US 6,080,583 A
• Filed: 05/21/1998
• Issued: 06/27/2000
• Est. Priority Date: 06/04/1997
• Status: Expired due to Fees

• Current Assignee: Sphere Medical Limited (Sphere Medical Holding Ltd.)
• Original Assignee: Siemens-Elema AB (Siemens AG)
• Inventors: von Bahr, Pontus
• Primary Examiner(s): Warden, Jill
• Assistant Examiner(s): NOGUEROLA, ALEXANDER STEPHAN
• Application Number:
  US09/082,442
• Time in Patent Office: 768 Days
• Field of Search: 422/68.1, 422/82.05, 422/82.08, 422/82.09, 436/11, 436/16, 436/48, 436/164, 436/165
• US Class Current: 436/16
• CPC Class Codes: A61B 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: A61M 1/3609 Physical characteristics of the blood, e.g. haematocrit, urea
• CPC Class Codes: G01N 33/4925 measuring blood gas content, e.g. O2, CO2 , HCO3
• CPC Class Codes: Y10T 436/106664 Blood serum or blood plasma standard or control

Abstract

In a blood analysis system and method, a measurement unit with a measurement cell is alternately filled with blood and at least two specific fluids. At least one of the specific fluids serves as a calibration fluid for the measurement unit. A tag substance is added to at least one of the specific fluids to make the fluids distinguishable from each other and from blood, and the measurement unit includes a detector, arranged in the measurement cell, for determining the identity of fluid present in the measurement cell. The entire blood analysis system can be controlled and monitored on the basis of the identity of the fluid in the measurement cell.

Claims

1. A blood analysis system comprising:

a measurement unit;

a measurement cell in said measurement unit;

means for alternatingly filling said measurement cell with blood and one of at least two fluids, said at least two fluids including a calibration fluid for said measurement unit;

at least one of said at least two fluids containing a distinguishable substance; and

a detector disposed in said measurement unit in communication with said measurement cell for determining an identity of a fluid other than the calibration fluid in said measurement cell containing said distinguishable substance.

2. A blood analysis system as claimed in claim 1 wherein said distinguishable substance comprises a colorant and wherein each of said at least two fluids contains a colorant distinguishing each of said at least two fluids from each other and from blood, and wherein said detector comprises an optical detector for determining the identity of the fluid in the measurement cell.

3. A blood analysis system as claimed in claim 1 wherein said distinguishable substance comprises an optically active agent, and wherein said at least two fluids respectively contain different optically active agents making said at least two fluids distinguishable from each other and from blood, and wherein said detector comprises an optical detector for determining the identity of the fluid in the measurement cell.

4. A blood analysis system as claimed in claim 1 wherein said distinguishable substance comprises an acoustically active agent, and wherein said at least two fluids respectively contain different acoustically active agents making said at least two fluids distinguishable from each other and from blood, and wherein said detector comprises an acoustic detector for determining the identity of the fluid in the measurement cell.

5. A blood analysis system as claimed in claim 1 wherein said distinguishable substance comprises an electrically active agent, and wherein said at least two fluids respectively contain different electrically active agents making said at least two fluids distinguishable from each other and from blood, and wherein said detector comprises an electric detector for determining the identity of the fluid in the measurement cell.

6. A blood analysis system as claimed in claim 1 wherein said distinguishable substance comprises an magnetically active agent, and wherein said at least two fluids respectively contain different magnetically active agents making said at least two fluids distinguishable from each other and from blood, and wherein said detector comprises an magnetic detector for determining the identity of the fluid in the measurement cell.

7. A blood analysis system as claimed in claim 6 wherein said detector comprises means for identifying when said measurement cell is filled with blood or fluid, and wherein said control means comprises for pumping blood or fluid into said measurement cell until said output signal from said detector indicates that said measurement cell with blood or is filled with said one of said at least two fluids.

8. A blood analysis system as claimed in claim 1 wherein said means for alternatingly filling said measurement cell comprises a plurality of containers for the respective fluids and a plurality of tubes respectively connecting said plurality of containers to said measurement unit, and a plurality of pumps for pumping the respective fluids through the respective tubes, wherein said detector comprises means for generating an output signal identifying said identity of the fluid in the measurement cell, and said system further comprising control means, connected to said pumps and to said detector, for regulating said pumps dependent on said output signal from said detector.

9. A blood analysis system as claimed in claim 1 further comprising an electric chemical sensor disposed in said measurement unit on a substrate in said measurement cell, and wherein said detector comprises a detector integrated onto said substrate.

10. A blood analysis system as claimed in claim 9 further comprising a pump for pumping said one of said at least two fluids into said measurement cell, and wherein said control means comprises means for identifying whether the identity of fluid in the measurement cell has changed within a predetermined time after activation of said pump, as said condition indicative of proper operation of said blood analysis system.

11. A blood analysis system as claimed in claim 1 wherein said detector generates an output signal dependent on the identity of the fluid in the measurement cell, and said system further comprising control means, supplied with said output signal from said detector, for analyzing said output signal and identifying at least one condition indicative of proper operation of said blood analysis system, said control means generating a control means output signal in an absence of said at least one condition, and said system further comprising an alarm unit, supplied with said control means output signal, which generates an alarm upon receiving said control means output signal.

12. A blood analysis system as claimed in claim 11 wherein said control means comprises means for identifying whether said measurement cell contains at least some fluid or blood, as said condition indicative of proper operation of said blood analysis system.

13. A method for regulating a blood analysis system comprising the steps of:

adding a distinguishable substance other than a calibrant to a first fluid and pumping said first fluid, with said distinguishable substance therein, into a measurement cell;

determining an identity of the fluid in the measurement cell by monitoring said distinguishable substance in said first fluid in said measurement cell;

terminating pumping of said first fluid into said measurement cell when said measurement cell is filled with said first fluid;

calibrating at least one measurement sensor in said measurement cell using said first fluid;

pumping blood into said measurement cell to replace said first fluid in said measurement cell;

identifying the presence of blood in said measurement cell;

terminating pumping of blood into said measurement cell when said measurement cell has filled with blood; and

measuring at least one parameter of said blood with said measurement sensor in said measurement cell.

14. A method as claimed in claim 13 comprising the additional steps of:

adding a distinguishable substance to a second fluid and pumping said second fluid into said measurement cell;

determining an identity of fluid present in said measurement cell by monitoring said distinguishable substance in said second fluid;

terminating pumping of said second fluid into said measurement cell when said measurement cell is filled with said second fluid; and

calibrating at least one measurement sensor in said measurement cell using said second fluid.