Patent ID: 8788005

Claim:
A system comprising: 1) a first module for optically generating at least first and second internal jugular venous output signals as current or voltage based on change in blood volume over time at at least first and second wavelengths of light, wherein said first module comprises at least one light source to emit the light and at least one photodetector to receive transmitted or reflected light of each wavelength from the light source and translate it into the output signals; 2) a second module comprising a pulse oximeter for generating at least first and second cardiac arterial output signals over time at the first and second wavelengths of light, respectively; and 3) a signal processing means that functions to calculate average cerebral blood oxygenation based on the output signals from the first module, arterial blood oxygenation based on the output signals from the second module and cerebral tissue oxygenation based on the difference between average cerebral blood oxygenation and arterial blood oxygenation.