Uab Vittamed

Uab Vittamed Technologijos

Gediminas Daubaris

Arminas Ragauskas

Vytautas Petkus

Renaldas Raisutis

Eugene A Saxon

Rolandas Zakelis

Mark A Moehring

Arne H Voie

Timothy Myers

Romanas Chomskis

Robert Giansiracusa

Steve Swedenburg

Mailee Hess

Marc McDaniel

Renaidas Raisutis

Algis Dziugys

Vytauatas Petkus

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.

Method and apparatus for continuously monitoring intracranial pressure

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 occur

Method and apparatus for determining the absolute value of intracranial pressure

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.

Apparatus and method for simulating arterial blood flow under various pressure conditions

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.

Method and apparatus for non-invasive continuous monitoring of cerebrovascular autoregulation state

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.

Apparatus and method of non-invasive cerebrovascular autoregulation monitoring

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.

Ultrasonic method and apparatus for measuring intracranial contents volume change

An ultrasonic method for indicating a characteristic of intraparenchymal brain tissue includes the transmission of broadband ultrasound from a transmitting transducer positioned on one side of a patient's cranium to a receiving transducer located on another side of the cranium 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 intraparenchymal tissue within the cranium.

Method and apparatus for non-invasively deriving and indicating of dynamic characteristics of the human and animal intracranial media

An apparatus for measuring the intracranial pressure in a non-invasive manner is described by using an ultrasonic Doppler device which detects the velocities of the blood flow inside the optic artery for both intracranial and extracranium optic artery portions. The eye in which the blood flow is monitored is subjected to a small pressure, sufficient to equalize the blood flow measurements of the internal and external portions of the optic artery. The pressure at which such equalization occurs is found to be an acceptable indication of the intracranial pressure. Various devices are illustrated and used to enable either an automatic or manual intracranial pressure measurement.

Method and apparatus for determining the pressure inside the brain

An ultrasonic non-invasive technique is descried for deriving the time dependencies of characteristics of certain regions in the intracranium medium. Precise measurements of the transit travel times of acoustic pulses are made and processed to extract variable portions indicative of, for example, the pulsatility due to cardiac pulses of a basal artery or a cerebroventricle or the variation in the pressure of brain tissue, as well as changes in the cross-sectional dimension of the basal artery and ventricle. In one technique, the transit time variations attributable to cardiac pulses are extracted by processing higher harmonics in the frequency domain. Frequency and phase detection techniques are described.

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Kaunas, Lithuania

Gediminas Daubaris