Method for optically determining total hemoglobin concentration

• US 5,773,301 A
• Filed: 07/14/1997
• Issued: 06/30/1998
• Est. Priority Date: 07/12/1996
• Status: Expired due to Term

• Current Assignee: Avl Medical Instruments AG (Roche Holding AG)
• Original Assignee: Avl Medical Instruments AG (Roche Holding AG)
• Inventors: Ziegler, Werner
• Primary Examiner(s): SNAY, JEFFREY R
• Application Number:
  US08/892,126
• Time in Patent Office: 351 Days
• Field of Search: 436/66, 436/67, 436/164, 436/171, 436/68, 356/40, 356/41, 600/328
• US Class Current: 436/66
• CPC Class Codes: G01N 21/314 with comparison of measurements at specific and non-specific wavelengths dual wavelength spectrometry G01J3/427
• CPC Class Codes: G01N 33/49 Blood chemical methods for determining blood cell populations G01N33/5094; chemical analysis of blood groups or blood types G01N33/80
• CPC Class Codes: G01N 33/721 Haemoglobin

Abstract

In a method of optically determining the total hemoglobin concentration (tHb) in non-hemolyzed whole blood, using at least two wavelengths for measuring, a first wavelength of λ<805 nm and a second wavelength of λ>805 nm is employed, such the following is valid for the absorption coefficients of hemoglobin derivatives O₂ Hb and RHb at the two measurement wavelengths λ₁ and λ₂ : σO(λ₁)˜σR(λ₂) and σR(λ₁)˜σO(λ₂). The sum of absorption values A₁ and A₂ measured at wavelengths λ₁ and λ₂ will be a quantity which is proportional to the total hemoglobin concentration tHb and independent of the oxygen saturation O_2sat.

Claims

1. A method for optically determining total hemoglobin concentration (tHb) in a sample of non-hemolyzed whole blood, comprising:

irradiating said sample of non-hemolyzed whole blood with light of a first measurement wavelength λ

₁ <

805 nm and a second measurement wavelength λ

₂ >

805 nm such that the following is valid for the absorption coefficients σ

O(λ

₁), σ

O(λ

₂), σ

R(λ

₁) and σ

R(λ

2) of the hemoglobin derivatives O₂ Hb and RHb at said two measurement wavelengths λ

₁ and λ

₂ ;

σ

O(λ

₁)˜

σ

R(λ

₂) and σ

R(λ

₁)˜

σ

O(λ

₂),

measuring the absorption values A₁ and A₂ at the wavelengths λ

₁ and λ

₂ and

calculating the sum of said two absorption values A₁ +A₂ as a quantity which is proportional to said total hemoglobin concentration tHb and independent of oxygen saturation O_2sat of said sample of non-hemolyzed whole blood.

2. The method of claim 1, wherein different excitation intensities I₁ and I₂ at measurement wavelengths λ

₁ and λ

₂ are compensated with a correction factor f, such that the total hemoglobin concentration tHb is proportional to a sum A₁ +fA₂, factor f being between 0.5 and 2.0 and representing a calibrating variable dependent on chosen measuring configuration.

3. The method of claim 1, wherein measurement wavelength λ

₁ is between 780 and 790 nm, and measuring wavelength λ

₂ is between 830 and 850 nm.

4. The method of claim 3 wherein measurement wavelength λ

₁ is 785±

3 nm, and measurement wavelength λ

₂ is 836±

3 nm.

5. The method of claim 1, wherein oxygen saturation O_2sat of said sample of non-hemolyzed whole blood is approximately determined from absorption values A₁ and A₂ by means of the formula