| 摘要 |
A method for determining the blood constituents of a patient comprising coupling an oximeter sensor arrangement to a tissue region of the patient; passing first and second lights through the patient's tissue region for a first period of time while the venous blood in the tissue region has a first volume and for a second period of time while the venous blood in the tissue region has a second volume, the first light being substantially in a red light range and the second light being substantially in an infrared light range; detecting a red light signal and an infrared light signal, the red and infrared signals having at least first and second frequencies; computing a first ratio of the red and infrared signals at the first frequency; computing a second ratio of the red and infrared signals at the second frequency; comparing the first and second ratios to determine a first blood constituent. |
