In vivo noninvasive monitoring of cerebral blood with optoacoustic technique.

We present the results of blood oxygenation (oxyhemoglobin saturation) measurements using an optoacoustic system in vivo in the superior sagittal sinus of sheep. The system included a nanosecond Nd:YAG laser as a source of radiation and a specially designed optoacoustic probe for signal detection. The optoacoustic signal induced in the superior sagittal sinus by the nanosecond laser pulses correlated well with actual oxyhemoglobin saturation measured with CO-oximeter. We propose to use a two- or multi- wavelength optoacoustic system for noninvasive continuous monitoring of cerebral venous blood oxygenation. The spectra of effective attenuation coefficient were measured in the range 680-1300 nm for oxy- and deoxygenated whole blood and can be employed for calibration of the system.