Trauma remains the leading cause of death and disability for Americans age 1-44. Trauma can cause internal bleeding, and this bleeding is often hard to detect without sophisticate tests that take time to complete and analyze.

In addition, internal bleeding, including bleeding into the lung and chest cavity, as well as other blood loss, happens in many critically ill patients. For example, for hemorrhage, it is very difficult to detect active hemorrhage and to determine optimal rates of fluid and blood resuscitation.

Diffuse optical spectroscopy has the potential to accurately assess adequacy of tissue perfusion, oxygenation, tissue oxygen extraction, and cytochrome oxidation states that may be critical to optimal treatment, end- organ preservation, and survival.

The research' want to monitor tissue perfusion and indicators of tissue damage and viability in critically ill patients by using DOS.

Non-invasive Optical Techniques DOS,near-infrared diffuse optical spectroscopy (NIR-DOS.

NIR-DOS provides functional physiologic tissue/organ information without ionizing radiation and without withdrawing any blood, in a cost-effective and rapid manner. The application of frequency-domain photon migration analysis (FDPM) to NIRS allows independent measurements of tissue absorption and scattering properties at depths of 1 cm or more below the skin surface.

Such capabilities will improve early diagnosis, detection, optimization of therapy, assessment of adequacy of resuscitation, and alteration in management plans for all of these critical conditions.

Inclusion Criteria:

• Adult age 18 years or older, male or female
• Trauma/Critical Care patient

Exclusion Criteria:

• Subject is not Trauma/Critical Care patient