Continuous, noninvasive monitoring of total hemoglobin concentration by an optoacoustic technique.

Measurement of total hemoglobin concentration [Hgb] is a blood test that is widely used to evaluate outpatients, hospital inpatients, and surgical patients, especially those undergoing surgery associated with extensive blood loss, rapid fluid administration, and transfusion of packed red blood cells. Current techniques for measurement of [Hgb] are invasive (requiring blood sampling) and cannot provide real-time, continuous monitoring. We propose to use an optoacoustic technique for noninvasive and continuous monitoring of [Hgb].