Abstract: Medical diagnostic system, apparatus and methods are disclosed. Optical transmitters generate radiation-containing photons having a specific interaction with at least one target chromophore in a target structure, preferably a blood vessel such as the interior jugular vein. The optical transmitters transmit the radiation into at least a first area including a substantial portion of the target structure and into a second area not including a substantial portion of the target structure. Optical receivers detect a portion radiation scattered from at least the first area and the second area. A processor estimates oxygenation, pH or cardiac output based on the scattered radiation detected from the first area, and the scattered radiation from the second area.

Abstract: Medical diagnostic system, apparatus and methods are disclosed. Optical transmitters generate radiation-containing photons having a specific interaction with at least one target chromophore in a target structure, preferably a blood vessel such as the interior jugular vein. The optical transmitters transmit the radiation into at least a first area including a substantial portion of the target structure and into a second area not including a substantial portion of the target structure. Optical receivers detect a portion radiation scattered from at least the first area and the second area. A processor estimates oxygenation, pH or cardiac output based on the scattered radiation detected from the first area, and the scattered radiation from the second area.

Abstract: A system and method for monitoring one or more parameters relating to blood, such as cardiac output, of a patient is provided. The system preferably includes an acoustic energy transducer unit configured and positioned to transmit acoustic energy into a target structure, preferably a blood vessel, within the patient so as to induce a measurable change, preferably a change in blood volume, within the target structure. The transducer unit can be an ultrasonic array, annular array, or groups thereof, or a single element transducer. The unit can also be a vibrator or acoustic loudspeaker. An optical transmitter transmits light into the target structure, and an optical receiver senses light scattered from within the target structure. The blood parameter can then be estimated from the sensed scattered radiation. Relative blood oxygen saturation in the blood vessel can be estimated by transmitting two wavelengths to measure oxy-hemoglobin and deoxy-hemoglobin.