Abstract: An ultrasound based technique for detecting and imaging vibrations in tissue caused by eddies produced during bleeding through punctured arteries or from organs. A clutter signal, normally suppressed in conventional color flow imaging, is employed to detect and characterize local tissue vibrations, to detect internal bleeding in an image, or as an audible or palpable signal, or a readout. Using a tissue vibration image, the origin and extent of vibrations relative to the underlying anatomy and blood flow can be visualized in real time, enabling measurements of vibration amplitude, frequency, and spatial distribution. Bleeding rate can be determined from the frequency and amplitude of the vibrations. Signal processing algorithms usable to identify tissue vibrations from an ensemble of 2D ultrasound data include those based on phase decomposition, spectral estimation using eigendecomposition, and spectral estimation using autoregressive modeling for isolating vibrations from clutter, blood flow, and noise.

Abstract: An intravascular ultrasonic imaging catheter is provided with a flexible circuit electrically coupled to a transducer array mounted on the distal end of the catheter, a portion of the flexible circuit being helically wound about the catheter in order to enhance the flexibility of the circuit. The catheter may be a balloon catheter which is also provided with a stent mounted on the balloon, the stent carrying one or more drugs designed to be eluted or washed into a patient's blood stream after the stent has been delivered, by a the balloon catheter, into a target area within the patient's vascular system.

Abstract: An ultrasonic Doppler diagnostic equipment according to the present invention is characterized by including a Doppler signal detection device which executes a filtering process for a plurality of reception signals obtained in time series at unequal intervals from a predetermined position within a patient by a transmission/reception device, thereby to detect Doppler signals based on a mobile object; a velocity calculation device which selects Doppler signals obtained at a predetermined time interval, from among the plurality of Doppler signals obtained at the unequal intervals by the Doppler signal detection device, and which calculates a velocity of the mobile object on the basis of the selected Doppler signals; and an image data generation device which generates velocity image data on the basis of the velocity of the mobile object as calculated by the velocity calculation device.

Abstract: A method, system and apparatus for ultrasonically imaging boli that are swallowed, as they are passed through the esophagus. The trajectories of the boli are tracked, and image data corresponding to the esophagus thereby identified. Analysis of boli and esophagus image data enable esophageal parameters correlated thereto to be determined.

Abstract: A method for evaluating flow characteristics in a vessel of a patient includes the steps of positioning a catheter having a balloon at a measuring location within the vessel; transmitting an ultrasound signal into the vessel while the balloon catheter is within the measuring location; evaluating a reflection of the ultrasound signal to determine a flow parameter within the vessel while the catheter is in the measuring position; expanding the balloon within the vessel at the measuring location; and stopping the expanding step when the result of the evaluating step is that the flow through the vessel is substantially stopped. In some embodiments, the method may further comprise the step of detecting an endovascular electrogram signal. The method may be designed for evaluating flow characteristics in a vessel of a patient while enabling the prevention of a balloon from over-expanding and/or over-distending a vessel of a patient.

Abstract: A method for discriminating particle groups comprises generating, by a particle analyzer, a particle characteristic distribution histogram in which the abscissa indicates respective channels for representing the characteristics of the particles, and the ordinate indicates the particle count; setting a valid area selection height in the particle characteristics distribution histogram; and generating an equivalent negative histogram based on the set height and the particle characteristic distribution histogram.

Abstract: The disclosed embodiments present improved catheters with physiological sensors. In one embodiment, the catheter includes, generally, a pressure transducer/electronics assembly connected to a pressure transmission catheter. The pressure transmission catheter includes a hollow tube made from a low compliance material. The distal end of the hollow tube is filled with a gel-like material or plug which acts as a barrier between the catheter liquid and the target fluid. The hollow tube is partially filled with a low viscosity liquid and is in fluid communication with the gel-like material and the pressure transducer. The pressure of the target fluid is transmitted to the liquid in the hollow tube through the gel-like material and/or the wall of the distal tip and is fluidically transmitted to the pressure transducer. The pressure transmission catheter may be inserted into a vessel lumen or into a lumen of a therapeutic or diagnostic catheter for biomedical applications.

Abstract: The invention relates to a facility that can be used, in particular, to measure the flow conditions in a blood vessel. The facility comprises a catheter (16) having a bundle (15) of optical waveguides that connects control and measurement facilities (20) outside the body with an optical unit (10) at the catheter tip. The light (?K) generated by a cavitation light laser source (30) is beamed via the catheter (16) and the optical unit (10) into a focus region (2) in the vessel lumen, where it generates cavitation bubbles (3). The movement of the cavitation bubbles (3) with the blood flow is determined by the particle-measuring unit (20) that is based, for example, on phase-Doppler anemometry and/or the Doppler shift. As a result of suitable design of the optical unit (10), the focus region (2) can be displaced as desired radially and rotationally inside the vessel so that a vessel cross section can be scanned in a spatially resolved way.

Abstract: A method and a device are provided for examining the properties of the global, in particular the primary, hemostasis functions in whole blood or platelet-rich plasma. A volumetric blood flow is preferably adjusted, depending on the measured pressure of the volumetric flow, so that the shear rate or the shear force, whose action in the reaction opening causes blood components, in particular thrombocytes, to deposit, follows a predetermined characteristic curve and in particular is held constant.

Abstract: Doppler Velocimetry is a widely used method for estimating stroke volume (SV). The accuracy and reliability of its measurement however, is dependant on a) the correct assessment of the aortic valve cross-sectional area (CSA), and b) the maximal systolic velocity integral (SVI). The invention avoids the conventional assessment of aortic valve CSA by using a calibration method: a reference stroke volume SVREF is determined by a method different from Doppler velocimetry, e.g. by thoracic electrical bioimpedance (TEB), or thoracic electrical bioadmittance, measured via surface thorax electrodes (transthoracic approach) or via electrodes located directly on an esophageal catheter/probe (esophageal approach). In the latter case, if esophageal Doppler velocimetry is used, the same catheter can be used for the placement of the electrodes and for an ultrasound transducer.

Abstract: An ultrasonic diagnosis apparatus comprises an ultrasound probe, a transmitter (including a transmitting pulse generator and a transmitting beamformer), a receiver (including a preamplifier and a receiving beamformer), a CFM processor (including a moving-element signal extractor and a velocity corrector), a tomographic image processor, and a display unit. The apparatus scans a desired section of a subject by transmitting and receiving an ultrasound pulse to and from the subject, and displays images obtained by the scanning. The velocity corrector comprises a pulsation-characterizing-velocity (velocities of a moving element) calculator, a representative velocity (reference velocity) calculator, and a corrector to correct the velocities of the moving element based on the standard velocity. The corrected velocity data is visualized on display unit. The ultrasonic diagnosis apparatus makes it possible to display the pulsatility of blood vessels in an easier and useful way.

Abstract: A medical diagnostic method, system and related equipment particularly adapted to diagnose disorders of the blood circulation serving the head and neck, and especially the brain. A preferred use of the system is early, rapid, accurate, diagnosis of stroke, especially whether the stroke is due to blockage of a blood vessel or leakage from the blood vessel.

Abstract: A volume dataset describes at least one tubular vessel and its environment. For processing the volume dataset, an operating point is first defined. A computer then determines slice planes containing the operating point and a sectional area enclosed by the vessel and contained in the respective slice plane for each of the slice planes. Finally, the computer determines the slice plane with the minimum sectional area and determines a working slice plane on the basis of this slice plane.

Abstract: Ultrasound Doppler probe 2 is placed above the vein downstream of the infusion site. Processor 4 converts the output from the probe 2 into a form that may be displayed as an image on display unit 5. It also determines whether the velocity corresponds to a flow of contrast medium along the vein. If the cannula 13 is properly sited and the contrast medium flows as desired along the vein, this will lead to an increased flow velocity in the vein. This is detected by ultrasound probe 2 and, as described above, the processor unit 4 will therefore determine that no extravasation has occurred. However, where extravasation of contrast medium occurs this results in a low or zero velocity output from the probe 2 from which the processor unit 4 determines that extravasation has occurred. It therefore immediately sends a “stop” signal to pump controller 11 which stops pump 10.

Abstract: A device for introduction into an animal or human body, especially into an artery. The device is preferably positioned in an aneurysmal sac in an artery between the wall of the artery and the wall of an endoprosthesis. The device has at least a pressure sensor and transducer for wirelessly transmitting data available from the pressure sensor.

Abstract: A cardiac lead is disclosed that includes a first lead body having opposed proximal and distal end portions and an interior lumen extending therethrough. The first lead body includes a sensor for measuring blood flow parameters to facilitate placement of the distal end portion thereof adjacent the coronary sinus. The first lead body has a distal electrode operatively associated with the distal end portion thereof and a proximal electrode operatively associated with the proximal end thereof. The second lead body has opposed proximal and distal end portions. A distal electrode is operatively associated with the distal end portion thereof and a proximal electrode operatively associated with the proximal end thereof. The second elongated lead body is dimensioned and configured for accommodation within the interior lumen of the first lead body.

Abstract: A density/solute monitor having at least one ultrasound probe, a signal processing unit, and a computing mechanism, and process for using the same, to measure phase shift between emitting and receiving ultrasound, sound velocity, compressibility, density, and solute concentration of fluid flowing through a fluid processing system. The ultrasound probe emits and receives ultrasound waves through the fluid and the signal-processing unit and computing mechanism process the ultrasound waves to determine phase and time shift. The computing mechanism converts phase shift to density, compressibility, and solute concentration measurements of the fluid. Calibrating fluids calibrate the detected phase shift in terms of sound velocity in the factory. Measurements provide information about passage of solutes and flow to achieve better solute collection efficiency, solution purity, and control of fluid processing systems.

Abstract: Valvular regurgitation is assessed by identifying a characteristic regurgitation jet in a colorflow image. An M-line is placed over the region of regurgitation and Doppler M-mode information is acquired from the flow convergence region adjacent the regurgitant orifice. The Doppler M-mode information, acquired at a higher acquisition rate than the colorflow frame rate, is used to produce a measure of the regurgitant flow rate and volume through the orifice. The flow rate can be used with velocity data acquired during the regurgitation event to produce a dynamic estimate of the size of the regurgitant valve orifice.

Abstract: A strobed blood flow meter provides periodic measurements of blood flow velocity or volumetric blood flow over a cardiac cycle at reduced average power consumption, which is advantageous for reducing battery size, and extending device battery life, such as in an implantable application. Continuous wave Doppler, pulsed Doppler, laser Doppler, transit time, electromagnetic flow, and thermal dilution techniques are included. Strobing provides higher level excitation during active periods, which improves signal-to-noise ratio, and provides a low power standby mode during an idle time between active periods. The invention may be used for chronic or acute applications. Doppler or other signals may be telemetered from an implanted portion of the flow meter for further signal processing to extract velocity or volumetric flow. Alternatively, such signal processing is also implanted, such that the velocity signal can be telemetered to an remote monitor.

Abstract: A one piece, sealed ultrasound probe head for measuring volume flow in vessels, which comprises a conventional ultrasound reflector (20) and piezo-electric crystals (23), mounted on a support element (30) which is permanently inserted into a housing (10) which is made of a resilient material and having gel spill guards (11) for limiting acoustic coupling gel spillage; and vessel retainer flaps (12) for retaining the vessel in a stationary position in the probe head. The probe head contains a supporting channel (16) capable of receiving and retaining on its surfaces an acoustic coupling gel. The resilient vessel retainer flaps (12) are capable of being flexed in order to selectively receiving or releasing the vessel into or out of the channel (16), and securing the vessel in a stationary position in said channel in order to allow flow measurement. The probe head in accordance with the invention may be used with any known probe device, including endoscopic probe devices.

Abstract: An apparatus and method to assess the compressibility of blood includes a combination of ultrasound transducers attached to tubing in which blood is flowing. An indicator medium is injected into the bloodstream of the subject over one or more time points and ultrasound waves are transmitted and monitored using transducers and phase lock amplifier to assess transmission time. Using a linear relationship between compressibility and density, changes in blood density are calculated from changes in transmission time to predict blood density changes and then the blood volume and microvascular pooling. This information allows prediction of complications that can occur during hemodialysis or because of post-traumatic fluid replacement and development of therapy to alleviate the complications.

Abstract: A method for phased-array ultrasonic transmission into a body wherein transmission from each element of the phased-array is implemented according to a firing order designed to generate a summated ultrasonic signal apparently originating from a virtual source outside of the body. The timing and order of firing of the phased-array elements is calculated from the relative proximities of each of the elements to the desired virtual source. The method allows for instantaneous ultrasonic localization of rapidly moving targets such as coronary thromboses.

Abstract: A method for the delivery of substances to a cell is disclosed. In a preferred embodiment, one administers continuous wave ultrasound or pulse-wave ultrasound to a cell bathed in a cocktail containing macromolecules and monitors the ultrasound using reflected echos of the ultrasound. One then observes incorporation of the substances into the cell. In a preferred embodiment of the present invention, macromolecules are combined in a cocktail solution comprising bubble micronuclei.

Abstract: An apparatus and method for operating a catheter guiding assembly, with one lumen providing access for an ultrasound imaging catheter and a second lumen providing a working port for a tool. Optionally, the ultrasound imaging catheter in the catheter guiding assembly is exposed to blood, and the ultrasound imaging catheter port has a gasket. Alternatively, the catheter guiding assembly is sealed to prevent blood contact by the ultrasound imaging catheter, and the ultrasound imaging catheter may be re-used several times. In either case, the working tool is in the field of view of the ultrasound imaging catheter and normally exposed to blood. Because the working tool is exposed to blood, the working port has a gasket to keep blood from leaking out. Optionally, the working port is used for fluid delivery for injecting contrast agent, chemicals or drugs, which can be activated by sonification from the ultrasound imaging catheter.

Abstract: Methods and apparatus for non-uniform rotation distortion detection for enhanced intravascular ultrasound imaging. The present invention provides methods and apparatus which detect non-uniform rotation in an improved manner without using beacons which may create shadowing of tissue behind the beacons or other undesired artifacts in the image. In specific embodiments, the present invention may provide a particularly simple and useful solution for addressing the problem of non-uniform rotation distortion in intravascular ultrasound imaging in systems which use mechanical scanning. In specific embodiments, the present invention utilizes correlation of received signals in an image vector from reverberating ultrasound in a bubbly liquid-flushed catheter to determine non-uniform rotation of the transducer within the catheter.

Abstract: Methods and apparatus for non-uniform rotation distortion detection for enhanced intravascular ultrasound imaging. The present invention provides methods and apparatus which detect non-uniform rotation in an improved manner without using beacons which may create shadowing of tissue behind the beacons or other undesired artifacts in the image. In specific embodiments, the present invention may provide a particularly simple and useful solution for addressing the problem of non-uniform rotation distortion in intravascular ultrasound imaging in systems which use mechanical scanning. In specific embodiments, the present invention utilizes correlation of received signals in an image vector from reverberating ultrasound in a bubbly liquid-flushed catheter to determine non-uniform rotation of the transducer within the catheter.

Abstract: The invention features an acoustic medical device for making Doppler measurements and imaging within a body fluid conduit using a single-transducer. The device has an elongated device body, defining a device axis, constructed for positioning a distal end of the device body near a region of interest in the body fluid conduit. Disposed within the device body is an ultrasonic beam directing assembly that is constructed to direct a portion of ultrasonic energy from a single transducer in a direction for imaging within the body fluid conduit and to direct another portion of the ultrasonic energy in a direction for making Doppler measurements within the body fluid conduit.

Abstract: Implantable apparatus for measuring a fluid flow in the body of a subject, including a stent, having a generally cylindrical radial outer wall and a central lumen. A flow parameter sensor is fixed to the stent, and measures a parameter relating to a rate of blood flow through the stent. A transmitter transmits signals responsive to the measured parameter to a receiver outside the body.

Abstract: Methods and apparatus for non-uniform rotation distortion detection for enhanced intravascular ultrasound imaging. The present invention provides methods and apparatus which detect non-uniform rotation in an improved manner without using beacons which may create shadowing of tissue behind the beacons or other undesired artifacts in the image. In specific embodiments, the present invention may provide a particularly simple and useful solution for addressing the problem of non-uniform rotation distortion in intravascular ultrasound imaging in systems which use mechanical scanning. In specific embodiments, the present invention utilizes correlation of received signals in an image vector from reverberating ultrasound in a bubbly liquid-flushed catheter to determine non-uniform rotation of the transducer within the catheter.

Abstract: A multi-function intraluminal ultrasound catheter assembly includes an axially disposed lumen having at least a first portion with a flat inner wall forming a "D-shaped" cross-section. An acoustic imaging window having a circular cross-section is connected to a distal end of the catheter assembly, wherein the cross-sectional dimension of the D-shaped portion of the lumen that extends from the flat inner wall is less that the available inner diameter of the imaging window. A flexible drive-shaft extends through the lumen and is connected to a transducer housing disposed in the acoustic imaging window area, the transducer housing having a substantially "D-shaped" outer perimeter, wherein the drive-shaft and connected transducer housing may thereby be retracted from the catheter assembly by first rotating the transducer housing until its D-shaped outer perimeter is substantially oriented with the D-shaped cross-section of the lumen.

Abstract: A blood flow velocity measurement device is devised where there exist such entities within the fluid which are detectable when axially flowing (passing by) an appropriate detector of known and well defined dimensions mounted onto a catheter. The entities produced for instance by a generator, when flowing by the detector, induced a known single response, the response bearing direct correlation to the flow velocity, in the form of direct reciprocity to the velocity and direct proportion to the length of the sensitive length of the detector. Autocorrelation of the function obtained by the overlap and pile-up of successive events is calculated and from the characteristic points in the autocorrelation function the axial velocity is inferred. The measurement is best when the probing beam is perpendicular to the flow.