Cuvette apparatus and system for measuring optical properties of a liquid such as blood

• US 20050094127A1
• Filed: 10/29/2004
• Published: 05/05/2005
• Est. Priority Date: 10/29/2003
• Status: Active Grant

• Current Assignee: Gambro Lundia AB (Baxter International Inc.)
• Original Assignee: CHF Solutions, Inc.
• Inventors: O'mahony, John J., Merrick, Edwin B., Hou, Xinrui
• Granted Patent: US 7,671,974 B2
• Time in Patent Office: Days
• US Class Current: 356/39
• CPC Class Codes: A61B 5/14557 specially adapted to extracorporeal circuits
• CPC Class Codes: G01N 21/05 Flow-through cuvettes G01N21/09 takes precedence; handling fluid samples G01N1/10
• CPC Class Codes: G01N 21/359 using near infrared light

Abstract

A optical sensor for measuring tranmissive properties of a solution having: a cuvette body with an enclosed flow passage for the solution, wherein the flow passage further includes a solution inlet and a solution outlet and a cuvette between the inlet and outlet; a light source projecting light of a predetermined wavelength through the cuvette and solution flowing through the cuvette and to a light sensor, wherein the cuvette has inner wall surfaces opaque to the light of said predetermined wavelength, and the inner wall is in contact with the solution.

Claims

1. An optical sensor for determining optical properties of a solution, said sensor comprising:

a cuvette body having an enclosed flow passage for the solution, wherein the flow passage further comprises a solution inlet and a solution outlet and a cuvette between the inlet and outlet;

a light source projecting light of a predetermined wavelength through the cuvette and solution flowing through the cuvette, and to a light sensor, and

said cuvette having an inner wall surface opaque to the light, and said inner wall is in contact with the solution.

2. The device of claim 1 wherein said inner wall surface of the cuvette further comprises opposite planer walls defining opposite sides of the flow passage in the cuvette.

3. The device of claim 1 wherein said inner wall surface of the cuvette further comprises opposite planer walls defining opposite sides of the flow passage in the cuvette, and said planer walls are separated by a distance less than one quarter of a width of each of the planer walls.

4. The device of claim 1 wherein said inner wall surface of the cuvette further comprises opposite planer walls defining opposite sides of the flow passage in the cuvette, and said planer walls are separated by a distance less than one quarter of a length of each of the planer walls.

5. The device of claim 1 wherein the inlet and outlet of the flow passage are circular in cross section, said cuvette further comprises opposite planer walls defining opposite sides of the flow passage in the cuvette, and said flow passage further comprise transition sections between the cuvette and each of said inlet and outlet.

6. The device of claim 1 wherein the cuvette body is formed of a black plastic material.

7. The device of claim 1 wherein the inner wall surfaces of the cuvette are black.

8. The device of claim 1 wherein the inlet, cuvette and outlet are coaxial.

9. The device of claim 1 wherein the cuvette further comprises opposite apertures in said inner wall surface, and said apertures are optically aligned with the light source and light detector.

10. The device of claim 9 further comprising optical diffusers fitted into each of said apertures.

11. The device of claim 9 further comprising opal disks fitted into each of said apertures.

12. The device of claim 1 wherein a solution flow direction through the cuvette is orthogonal to a solution flow direction through the inlet and the outlet.

13. The device of claim 1 wherein the cuvette body further comprises a lamination of opaque plates having opposing slots defining the cuvette.

14. A hemoglobin sensor for extracorporeal blood comprising:

a cuvette body having an enclosed flow passage for the solution, wherein said flow passage further comprises a solution inlet, a solution outlet and a cuvette between the inlet and outlet;

a light source projecting light of a predetermined wavelength through the cuvette, the solution flowing through the cuvette and to a light sensor, wherein said predetermined wavelength has a wavelength in a range of about 800 to 930 nm, and

said cuvette has an inner wall surface opaque to the light of said predetermined wavelength, and said inner wall is in contact with the solution.

15. A hemoglobin sensor as in claim 14 wherein the light detector is responsive substantially only to the wavelength of the light from the light source.

16. A hemoglobin sensor as in claim 14 wherein the light is cyclically turned on and off at a defined rate, and, during each cycle, said light detector generates a first signal when the light beam is on and a second signal when the light source is off.

17. A method for sensing blood concentrations in a blood carrying tube using a hemoglobin detector having a cuvette, a light source, an optical path extending through the cuvette and a light sensor, said method comprising:

a. connecting the tube to an inlet and to an outlet of the detector;

b. passing blood from the tube and through the cuvette, wherein the cuvette has an internal surface in contact with the blood and said internal surface is opaque to light from the light source;

c. projecting the light from the light source through the cuvette and blood passing through the cuvette and to the light sensor, and

d. measuring the light detected by the light sensor to determine whether a concentration of hemoglobin in the blood is above a threshold concentration level.

18. A method as in claim 17 further comprising ceasing blood flow through the tube if the concentration of hemoglobin is above the threshold concentration level.

19. A method as in claim 17 further comprising ceasing a filtration of the blood if the concentration of hemoglobin is above the threshold concentration level.

20. A method as in claim 17 further comprising reducing a filtration of the blood if the concentration of hemoglobin is above the threshold concentration level.

21. A method as in claim 17 wherein said light has a wavelength in a range of about 800 to 930 nm.