Total hemoglobin concentration measurement

Abstract

A method for operating a spectrophotometric instrument of the type for measuring the oxygenation state of hemoglobin in tissue. The method includes the use of stored hemoglobin concentration relationship data characterizing the relationship between second derivative absorbance values at a hemoglobin-absorbing wavelength and hemoglobin concentration in a tissue as a function of hemoglobin oxygenation state. Data representative of a second derivative absorbance value of tissue being analyzed is received. The hemoglobin oxygenation state of the tissue is determined as a function of the second derivative absorbance value. The hemoglobin concentration in the tissue is then determined as a function of the hemoglobin concentration relationship data, the second derivative absorbance value and the hemoglobin oxygenation state. The accuracy of the hemoglobin oxygenation state can be determined as a function of the hemoglobin concentration value.

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