Use of Near Infrared Spectroscopy to Measure Intracranial ScvO2

The purpose of this study is to determine whether analysis of near infrared absorbance signals that occur at different frequencies might provide information about the difference in oxygen saturation between arterial and venous blood.

Inclusion Criteria:

• Adult 18-65 years of age

Exclusion Criteria:

• Dilated cardiomyopathy
• Congestive heart failure
• Pulmonary hypertension
• Severe aortic stenosis
• Flail chest
• Chest pain
• Shortness of breath