Noninvasive, non-occlusive method and apparatus which provides a continuous indication of arterial pressure and a beat-by-beat characterization of the arterial system
AssigneeMedwave, Inc.
InventorGary L. McQuilkin
Life of this patent
Estimating the term…
Abstract
A noninvasive arterial pressure monitor provides calibrated, continuous pressure waveform and beat-by-beat pressure values with no occlusion of an artery during an extended monitoring period. Noninvasive doppler sensors are secured over a major artery. Signals from the sensors are used to mathematically characterize the artery. The time-varying arterial resonant frequency is correlated to blood pressure throughout the cardiac cycle. Doppler sensors provide bi-directional flow velocity waveforms from which arterial resonant frequency may be calculated. A calibration cuff is used infrequently to calibrate the system to units of pressure.
Claims68
An apparatus for measuring blood pressure comprising:
- noninvasive sensor means for providing an output representative of blood flow in a blood carrying artery;
- processing circuitry means coupled to the noninvasive sensor means for receiving the output representative of blood flow and providing a processed output;
- resonant frequency identification circuitry means coupled to the processing circuitry means for receiving the processed output, calculating a time-varying resonant frequency of the artery and providing a resonant frequency output;
- and
- output means coupled to the resonant frequency identification circuitry means for providing an output representative of blood pressure in the artery based upon the resonant frequency output.
The apparatus of claim wherein the noninvasive sensor means comprises a plurality of doppler sensors.
An apparatus for measuring blood pressure comprising:
- noninvasive blood velocity sensor means for sensing blood flow velocity in an artery;
- means, coupled to the noninvasive blood velocity sensor means, for providing an output representative of a resonant frequency of the artery;
- a resonant frequency to blood pressure conversion circuit means, coupled to the means for providing an output representative of a resonant frequency of the artery, for converting a resonant frequency of the artery to a blood pressure output;
- and
- display means, coupled to the resonant frequency to blood pressure conversion circuit means, for displaying an output representative of blood pressure in the artery.
An apparatus for measuring blood pressure comprising:
- means for measuring an arterial parameter which correlates to arterial resonant frequency;
- means, coupled to the means for measuring an arterial parameter, for calculating blood pressure in the artery based upon arterial resonant frequency;
- and
- output means, coupled to the means for calculating blood pressure, for providing an output representative of blood pressure.
A method of testing a blood vessel system, comprising:
- deriving from a blood vessel a first signal from which a time-varying resonant frequency is derived;
- processing the first signal to produce a second signal representative of the time-varying resonant frequency of the blood vessel system;
- and
- providing a test output based upon the second signal representative of the time-varying resonant frequency of the blood vessel system.
A method of measuring blood pressure comprising:
- noninvasively deriving from an artery a signal from which time-varying arterial resonant frequency is derived;
- processing the signal to produce a waveform representative of time-varying arterial resonant frequency;
- and
- providing a blood pressure output based upon the waveform.
A method of blood pressure measurement comprising:
- measuring blood flow velocity through an artery;
- deriving from the blood flow velocity an arterial resonant frequency waveform;
- and
- providing a blood pressure output based upon the waveform.
A method of measuring blood pressure comprising:
- sensing blood flow velocity in an artery with a first noninvasive sensor;
- sensing blood flow velocity in the artery with a second noninvasive sensor positioned distally along the artery with respect to the first noninvasive sensor;
- deriving from the blood flow velocities sensed by the first and second noninvasive sensors a time-varying arterial resonant frequency waveform;
- and
- providing blood pressure output derived from the waveform.
An apparatus for testing a blood vessel system comprising:
- a sensor means for coupling to a blood vessel system and providing a sensor output;
- means for processing the sensor output to produce a resonant frequency signal representative of a time-varying resonant frequency of the blood vessel system;
- and
- means for providing a test output representative of time-varying resonant frequency of the blood vessel system.
An apparatus for measuring blood pressure, comprising:
- a noninvasive sensor means for deriving an arterial signal from which time-varying arterial resonant frequency is derived;
- signal processing means for receiving the arterial signal and producing an resonant frequency output representative of arterial time-varying resonant frequency;
- and
- means for providing a blood pressure output based upon the resonant frequency output.
An apparatus for measuring blood pressure, comprising:
- means for measuring blood flow velocity through an artery;
- means for deriving from the blood flow velocity an arterial resonant frequency waveform;
- and
- output means for providing a blood pressure output based upon the waveform.
An apparatus for measuring blood pressure comprising:
- a first noninvasive sensor means for sensing blood flow velocity in an artery;
- a second noninvasive sensor means for sensing blood flow velocity in an artery;
- means for deriving from the blood flow velocities sensed by the first and second noninvasive sensor means a time-varying arterial resonant frequency waveform;
- and
- output means for providing a blood pressure output derived from the waveform.
Dependencies are inferred from the claim text.