Apparatus and method for measuring blood oxygen saturation

• US 4,444,498 A
• Filed: 08/20/1982
• Issued: 04/24/1984
• Est. Priority Date: 02/27/1981
• Status: Expired due to Term

• Current Assignee: Jostra Bentley, Inc.
• Original Assignee: Bentley Laboratories Incorporated
• Inventors: Heinemann, Stanley O.
• Primary Examiner(s): McGraw, Vincent P.
• Application Number:
  US06/410,039
• Time in Patent Office: 613 Days
• Field of Search: 356/39, 356/40, 356/41, 356/246, 356/410, 356/411
• US Class Current: 356/246
• CPC Class Codes: A61B 5/14557 specially adapted to extracorporeal circuits
• CPC Class Codes: A61M 1/361 before treatment
• CPC Class Codes: A61M 1/3612 after treatment
• CPC Class Codes: G01N 2021/3144 for oxymetry
• CPC Class Codes: G01N 2021/3181 using LEDs
• CPC Class Codes: G01N 21/3151 using two sources of radiation of different wavelengths G01N21/33 - G01N21/39 take precedence
• CPC Class Codes: G01N 21/85 Investigating moving fluids or granular solids
• CPC Class Codes: G01N 2201/0621 Supply
• CPC Class Codes: G01N 2201/069 Supply of sources

Abstract

A device and method for measuring blood characteristics and parameters, especially arterial, venous, or differential blood oxygen saturation levels uses one or two probes containing a unique configuration of light emitters of two different wavelengths, and sensors which alternately illuminate and read reflected light from blood passing through a specially-designed cuvette. Electronic comparison of reflected radiation received by the probes produces a voltage which is linearly related to blood oxygen saturation level. An opto-electronic feedback network compensates for differences in blood optical density.

Claims

1. A cuvette for use in conjunction with electrooptical measurement of blood parameters, comprising:

a body portion comprised of an optically clear biocompatible material;

a substantially flat window area disposed in said body portion;

end portions for connection to tubing or apparatus for conducting blood or other liquids therethrough; and

a lightproof backing having light absorbing properties on the surface proximate to said body portion, said backing located on at least the surface of said body portion opposite said window area, but not on said window area.

2. The cuvette of claim 1 wherein the flow path is substantially straight flow through in order to reduce cavitation and turbulence.

3. The cuvette of claim 1 wherein the sides of said body are free of said light-proof backing to permit priming inspection.

4. The cuvette of claims 1 or 2 further comprising means for optically coupling radiation sources and at least one radiation sensor to said cuvette.

5. The cuvette of claim 4 wherein said means consists of fiberoptic means.