Abstract: The invention is directed generally to a method and apparatus for non-invasively determining and intraorbital and intracranial compliance values in mammals including humans.

Abstract: The present invention is directed generally to a method and apparatus for human brain neuroprotection during surgery. The invention includes use of a heart-lung machine to generate periodic rectangular pulsation of blood flow. The invention uses a non-invasive CA monitor to continuously record transient functions such as dynamic autoregulation functions of a human brain cerebrovascular autoregulation system and process the data to generate an alarm to indicate CA impairment and take steps to minimize the CA impairment event.

Abstract: An ultrasonic flow meter includes a flow tube, and first and second ultrasound transducers that transmit ultrasonic pulses through a liquid flowing through the tube. The flow tube includes a reflector assembly that reflects pulses from the first transducer to the second transducer, and from the second transducer to the first transducer, thereby facilitating different sequences of time-of-flight measurements. A microcontroller obtains multiple sequences of measurements, where all the measurements in a single sequence are of the same measurement type, and each sequence uses a different type of measurement than that used by the other sequences. The microcontroller filters out the longest and shortest time-of-flights and, using an average of the remaining time-of-flights, calculates a volumetric flow rate of the fluid.

Abstract: An ultrasonic flow meter includes a flow tube, and first and second ultrasound transducers that transmit ultrasonic pulses through a liquid flowing through the tube. The flow tube includes a reflector assembly that reflects pulses from the first transducer to the second transducer, and from the second transducer to the first transducer, thereby facilitating different sequences of time-of-flight measurements. A microcontroller obtains multiple sequences of measurements, where all the measurements in a single sequence are of the same measurement type, and each sequence uses a different type of measurement than that used by the other sequences. The microcontroller filters out the longest and shortest time-of-flights and, using an average of the remaining time-of-flights, calculates a volumetric flow rate of the fluid.

Abstract: An apparatus and method for noninvasively measuring intracranial pressure of a subject using an ultrasound transducer. The transducer is used to measure arterial wall movement of an intracranial segment and an extracranial segment of the subject's ophthalmic artery as different external pressure forces are applied to the orbital area of the subject. When the waveforms of arterial wall movement between the intracranial segment and the extracranial segment are similar the intracranial pressure can be determined.

Abstract: A method and system of predicting a hypotensive episode in a patient using one or more time varying hypotension specific biomarkers corresponding to physiological processes in the patient. Data derived from sensors or other measurement devices such as ECG sensors can be used to generate biomarkers. The biomarkers can then be used to generate an acute hypotension prediction classifier, or monitored factor, derived from a three dimensional temporal representation of two or more biomarkers. When the monitored factor exceeds a predetermined threshold the method and system trigger an alarm before an appearance of a hypotensive episode in the patient.

Abstract: A method and system of predicting a hypotensive episode in a patient using one or more time varying hypotension specific biomarkers corresponding to physiological processes in the patient. Data derived from sensors or other measurement devices such as ECG sensors can be used to generate biomarkers. The biomarkers can then be used to generate an acute hypotension prediction classifier, or monitored factor, derived from a three dimensional temporal representation of two or more biomarkers. When the monitored factor exceeds a predetermined threshold the method and system trigger an alarm before an appearance of a hypotensive episode in the patient.

Abstract: A head frame for use in non-invasively determining the absolute value of intracranial pressure of a living body having a hard, flexible shield for covering the eye area of a patient. The shield has an inner surface and an outer transducer surface. An elastic film is sealed along its outer edge to the inner surface of the shield forming an expandable chamber. First and second connectors are located on the shield, permitting an inflow and outflow of pressurized liquid to the chamber. The elastic film expands inward toward the patient with an inflow of pressurized liquid, imparting a pressure against the patient's eye. An adjustable strap is attached to the shield for securing the head frame to the head of the patient.

Abstract: A method and apparatus for continuously measuring the absolute intracranial pressure in a non-invasive manner is described by using an ultrasonic Doppler device which detects the pulsatility indexes of the blood flow inside the eye artery for both intracranial and extracranial eye artery portions. The eye in which the blood flow is monitored is subjected to a small pressure, sufficient to equalize the pulsatility index measurements of the internal and external portions of the eye artery. The pressure at which such equalization occurs is used as a reference for autocalibration of the apparatus so that continuous absolute intracranial pressure measurements may be taken over a particular sampling period.

Abstract: A method and apparatus for continuously measuring the absolute intracranial pressure in a non-invasive manner is described by using an ultrasonic Doppler device which detects the pulsatility indexes of the blood flow inside the eye artery for both intracranial and extracranial eye artery portions. The eye in which the blood flow is monitored is subjected to a small pressure, sufficient to equalize the pulsatility index measurements of the internal and external portions of the eye artery. The pressure at which such equalization occurs is used as a reference for autocalibration of the apparatus so that continuous absolute intracranial pressure measurements may be taken over a particular sampling period.

Abstract: A method and apparatus for obtaining the absolute value of intracranial pressure in a non-invasive manner is described by using an ultrasonic Doppler measuring device which detects the intracranial and extracranial blood flow velocities of the intracranial and extracranial segments of the ophthalmic artery. The eye in which the blood flow is monitored is subjected to an external pressure, sufficient to equalize the intracranial and extracranial angle-independent blood flow factors calculated from the intracranial velocity signal and extracranial velocity signal.

Abstract: A method and apparatus for continuously measuring the absolute intracranial pressure in a non-invasive manner is described by using an ultrasonic Doppler device which detects the pulsatility indexes of the blood flow inside the eye artery for both intracranial and extracranial eye artery portions. The eye in which the blood flow is monitored is subjected to a small pressure, sufficient to equalize the pulsatility index measurements of the internal and external portions of the eye artery. The pressure at which such equalization occurs is used as a reference for autocalibration of the apparatus so that continuous absolute intracranial pressure measurements may be taken over a particular sampling period.

Abstract: An apparatus and method for simulating human ophthalmic artery for testing of ultrasound devices is disclosed, whereby two chambers are provided and are capable of being independently pressurized, one representing the intra-cranial space and the other representing extra-cranial space, and whereby a tube running through both chambers is provided, simulating the course of the ophthalmic artery and capable of being pressurized to stimulate arterial pressure. The apparatus is operated by pressuring both chambers, and pumping a blood-imitating fluid through the vessel in a pulsatile manner.

Abstract: A non-invasive method for continuous real-time monitoring of cerebrovascular blood flow autoregulation state includes simultaneous non-invasive monitoring of intracranial blood volume respiratory waves and lung volume respiratory waves, real-time decomposition of intracranial blood volume respiratory waves and lung volume respiratory waves into narrowband sinewave first harmonic components, determination therefrom of the phase shift between intracranial blood volume respiratory wave and lung volume respiratory wave first harmonics' and derivation of cerebrovascular autoregulation state from that phase shift value.

Abstract: A non-invasive method for monitoring of cerebrovascular blood flow autoregulation state includes sensing intracranial blood volume waves, filtering a slow wave, respiratory wave, and pulse wave informative components from said intracranial blood volume waves, filtering slow wave and respiratory wave reference components from the pulse wave envelope, calculating a first phase shift between said slow wave informative component and said slow wave reference component, calculating a second phase shift between said respiratory wave informative component and said respiratory wave reference component, and calculating the index of evaluation of the status of cerebral autoregulation state (ICAS) from said first phase shift and said second phase shift.

Abstract: An ultrasonic method for indicating a characteristic of intracranial components' volume changes includes the transmission of broadband ultrasound from a transmitting transducer positioned on one side of a human head to a receiving transducer located on another side of the human head with decomposition of the received signal into narrowband components and determination therefrom of group delay, phase angle and attenuation as a basis for derivation of the characteristic of the intracranial media.

Abstract: An apparatus and method for simulating human ophthalmic artery for testing of ultrasound devices is disclosed, whereby two chambers are provided and are capable of being independently pressurized, one representing the intra-cranial space and the other representing extra-cranial space, and whereby a tube running through both chambers is provided, simulating the course of the ophthalmic artery and capable of being pressurized to stimulate arterial pressure. The apparatus is operated by pressuring both chambers, and pumping a blood-imitating fluid through the vessel in a pulsatile manner.

Abstract: A method and apparatus for obtaining the absolute value of intracranial pressure in a non-invasive manner is described by using an ultrasonic Doppler measuring device which detects the intracranial and extracranial blood flow velocities of the intracranial and extracranial segments of the ophthalmic artery. The eye in which the blood flow is monitored is subjected to an external pressure, sufficient to equalize the intracranial and extracranial angle-independent blood flow factors calculated from the intracranial velocity signal and extracranial velocity signal. The absolute value of the intracranial pressure is identified as that external pressure at which such equalization occurs.

Abstract: A method and apparatus for continuously measuring the absolute intracranial pressure in a non-invasive manner is described by using an ultrasonic Doppler device which detects the pulsatility indexes of the blood flow inside the eye artery for both intracranial and extracranial eye artery portions. The eye in which the blood flow is monitored is subjected to a small pressure, sufficient to equalize the pulsatility index measurements of the internal and external portions of the eye artery. The pressure at which such equalization occurs is used as a reference for autocalibration of the apparatus so that continuous absolute intracranial pressure measurements may be taken over a particular sampling period.

Abstract: A non-invasive method for monitoring of cerebrovascular blood flow autoregulation state includes sensing intracranial blood volume waves, filtering a slow wave, respiratory wave, and pulse wave informative components from said intracranial blood volume waves, filtering slow wave and respiratory wave reference components from the pulse wave envelope, calculating a first phase shift between said slow wave informative component and said slow wave reference component, calculating a second phase shift between said respiratory wave informative component and said respiratory wave reference component, and calculating the index of evaluation of the status of cerebral autoregulation state (ICAS) from said first phase shift and said second phase shift.