Photon density wave based determination of physiological blood parameters

A system for measuring a physiological parameter of blood in a patient, the system comprising:

• a transmission module configured to emit a first modulated optical signal and a second modulated optical signal into tissue of the patient;
• a receiver module configured to detect the first modulated optical signal and the second modulated optical signal propagated in the tissue during a pulsatile perturbation;
• a processing module configured to:
• process the detected first modulated optical signal and the detected second modulated optical signal to determine at least an amplitude and a phase delay of both the detected first modulated optical signal and the detected second modulated optical signal;
• determine time based characteristics of the pulsatile perturbation of the tissue based on at least the amplitude and the phase delay of both the detected first modulated optical signal and the detected second modulated optical signal;
• and
• determine a value of the physiological parameter based on at least the characteristics of the pulsatile perturbation of the tissue and the amplitude and the phase delay of both the detected first modulated optical signal and the detected second modulated optical signal.

A method of operating a system for measuring a physiological parameter of blood in a patient, the method comprising:

• emitting a plurality of photon density waves into tissue of the patient from a plurality of modulated light sources;
• detecting characteristics of the plurality of photon density waves;
• identifying time based characteristics of a pulsatile perturbation of the tissue based on the characteristics of the plurality of photon density waves;
• and
• identifying a value of the physiological parameter based on at least the characteristics of the pulsatile perturbation of the tissue and the characteristics of the plurality of photon density waves.