Accuracy of Methemoglobin Measurement for Rainbow DCI Sensors

In this study, the level of methemoglobin (HbMet) will be increased in a controlled manner by administering sodium nitrite intravenously in healthy volunteers. The accuracy of a noninvasive HbMet measurement by a DCI pulse oximeter sensor will be assessed by comparison to blood measurements from a laboratory analyzer.

Inclusion Criteria:

1. Subjects must understand and consent to be in the study
2. American Society of Anesthesiology Class I (Healthy subjects without any systemic disease at all).

Exclusion Criteria:

1. Subjects who have any systemic disease at all.
2. Subjects who do not understand the study and the risks involved.
3. Current smokers.
4. Subjects who are pregnant.