Abstract: The present invention relates to a method and associated apparatus for improving the accuracy with which the speed of a fluid, such as a liquid, in particular blood flowing in a duct, such as a blood vessel, in particular the aorta, is measured by means of a signal emitted by a Doppler transducer (4). In characteristic manner, according to the method, the Doppler transducer is associated with a programmable memory (50) which contains at least one correction data item for correcting the Doppler signal transmitted by the transducer (4) to a transducer control and computer unit (8). Said computer unit (8) incorporates said signal correction data item in its computation (at 16) of each speed measurement on the basis of each signal emitted by the Doppler transducer, and it computes the speed value while taking account of said correction data item so as to provide a corrected measurement of the speed of said fluid, thereby improving its accuracy.

Abstract: A parenchymatous tissue image and a blood vessel image are synthesized as follows. First, a tomographic image of a specific cross section of the parenchymatous tissue image is synthesized with the blood vessel image closer to the viewpoint along the Z-axis than the tomographic image. Then, the resulting image is displayed. Thereafter, the operator inputs specific data from operation unit including a mouse and a keyboard, thereby changing the position of a displayed tomographic image along the Z-axis. This enables the operator to sequentially display two-dimensional tomographic images (B-mode images) constituting a three-dimensional parenchymatous tissue image as if to turn over the pages of a book.

Abstract: An ultrasound imaging system produces three-dimensional tissue/flow images by first computing a plurality of separate two-dimensional tissue images and two-dimensional flow images. Separate tissue and flow volumes are created by applying the tissue and flow images to a three-dimensional construction algorithm. Each of the separate tissue and flow volumes is analyzed using a three-dimensional rendering algorithm to produce a rendered tissue and flow image. The separately rendered tissue and flow images are combined to produce the combined tissue/flow image. In addition, the present invention provides visual cues that allow a user to create more even scans. The invention also includes a method for correcting for probe movement. The invention also produces an image that is calculated from the partial volume data as it is being created to give a user feedback on the quality of the image they are producing.

Abstract: To accurately measure wave intensity as an evaluation value using an ultrasonic diagnostic apparatus, a measurement line is set in a tomogram and anterior and posterior walls of a blood vessel are tracked on the measurement line, so that a change waveform concerning a blood vessel diameter is prepared. A tracking gate S is set on the measurement line, so that a blood velocity change waveform is prepared based on echo data concerning a part within the tracking gate S, the change waveform indicating averaged blood velocity. Wave intensity is calculated based on the blood vessel diameter change waveform and the blood velocity change waveform. Prior to the calculation of wave intensity, the blood vessel diameter change waveform is calibrated based on the maximum and minimum blood pressure values into a blood pressure waveform. A beam for Doppler measurement may be set intersecting with the displacement measurement beam.

Abstract: A non-invasive methodology and instrumentation for the detection and localization of abnormal blood flow in a vessel of a patient is described. An array of sensors are positioned on an area of a patient's body above a volume in which blood flow may be abnormal. Signals detected by the sensor array are processed to display an image which may indicate the presence or absence of abnormal blood flow.

Abstract: A method of determining the velocity of a flowing material, suspended in a liquid and flowing in a conduit, including irradiating the conduit with ultrasonic waves, detecting first Doppler-shifted reflections of the waves from the material, which first reflections have a positive Doppler-shift, and detecting second Doppler shifted reflections of the waves from the material, which second reflections have a negative Doppler-shift. The flow velocity is estimated based on the extent of the positive and negative Doppler-shifts. The first and second reflections may be summed to form a composite signal and the range of Doppler-shifts in the composite signal is used to estimate the flow velocity.

Abstract: A method for treatment of a disease comprising vasospasm or other symptom alleviable by smooth muscle relaxation and a vasodilator delivery system. The figure is a TCD of MCA post nitroglycerine spray obtained during continuous monitoring.

Abstract: An apparatus for diagnosing male impotence by measuring blood velocity in a cavernosal artery of a male penis includes at least one transducer for transmitting/receiving energy and reading corresponding Doppler effect to detect blood velocity in the cavernosal artery, a transducer housing for supporting the transducer in a substantially fixed orientation with respect to the penis as the transducer measures blood velocity in the cavernosal artery, and a fixing device, mechanically coupled to the transducer housing, to substantially mechanically fix the transducer housing in place with respect to the penis and hold the at least one transducer in a substantially constant angular orientation with respect to the cavernosal artery during an impotence diagnostic procedure. Corresponding methods are also disclosed.

Abstract: An ultrasonic color Doppler imaging system capable of discriminating an artery and a vein discriminates types of blood vessels such as the artery and the vein, and discriminatively displays the discriminated result on a display. The blood vessel types of the artery and the vein are determined using blood stream information according to a temporal change of a blood stream velocity pattern, and a different color is displayed according to the determined blood vessel type. Also, the brighter or darker color is displayed according to the blood stream velocity flowing in the blood vessel, to thereby provide accurate blood stream information.

Abstract: An ultrasonic imaging system includes an ultrasonic transducer having an image data array and a tracking array at each end of the image data array. The tracking arrays are oriented transversely to the image data array. Images from the image data array are used to reconstruct a three-dimensional representation of the target. The relative movement between respective frames of the image data is automatically estimated by a motion estimator, based on frames of data from the tracking arrays. As the transducer is rotated about the azimuthal axis of the image data array, features of the target remain within the image planes of the tracking arrays. Movements of these features in the image planes of the tracking arrays are used to estimate motion as required for the three-dimensional reconstruction. Similar techniques estimate motion within the plane of an image to create an extended field of view.

Abstract: The present invention is directed toward a method and apparatus for stimulating and/or monitoring hemodynamic activity, such as blood flow, in a penis. The method of the present invention comprises the coupling of an ultrasound source to the outer surface of the penis and transmitting ultrasound energy into the penis at a sufficient frequency and intensity to increase hemodynamic activity. An apparatus is also provided for practicing the method of the present invention. The apparatus provides for position adjustment of the ultrasound transducers during the circumferential expansion of the penis resulting from increased hemodynamic activity.

Abstract: A pressure volume loop of the heart of a patient is obtained utilizing an electrocardiograph and a brachial-artery pressure cup pressure-measurement system having an echo-Doppler sensor positioned to measure the flow waves at the aortic root.

Abstract: To be able to optimize the hemodialysis treatment process, in-vivo determination of important parameters, such as the exchange efficiency of the dialyzer, represented by the dialysance or clearance, is desirable. Mathematical quantification of the blood purification processes on the basis of measurement technology is especially important. Important measured quantities and operands for the determination of the desired parameter are usually the dialysate flow and the blood flow (Qd, Qb), the inlet and outlet concentrations (cdi, cdo) of the dialysis fluid and the electrolyte transfer rate derived from it as well as the formulation of the mass balance in the dialyzer.

Abstract: The present invention is directed toward a method for accelerating the delivery of a vasodilating agent to the penis. The method of the present invention comprises ingesting a vasodilating agent into the body at a point of ingestion external to the penis, and transmitting ultrasound energy into the penis at a sufficient frequency and intensity to increase hemodynamic activity.

Abstract: A method to measure spatial fluid flow components and their velocity profiles in a number of locations in a cross-sectional area of a lumen or other body cavity by using ultrasound in which the cross-sectional area is interrogated by a plurality of ultrasonic beams; the estimation of the spatial flow components is obtained from a combination of estimations of axial, lateral and total flow; the estimation of one or more flow components is obtained through any combination of time-shift and decorrelation analysis of two or more beam-signals of the interrogating ultrasound transducer, and the estimation accuracy is further improved by the use of a reference decorrelation curve.

Abstract: Upon detection of systole by a detector (21), a master controller (20) adjusts a transmit level control (36) to cause a transducer array (2) to transmit ultrasound waves with a high acoustic output approaching the mechanical index FDA limit with sufficient dwell time between HAO frames to limit the temporal average below the FDA limit. The dwell time may be occupied by lower acoustic output frames (LAO) which are generated using the transmit level control (36).

Abstract: A pulse Doppler ultrasound system and associated methods are described for monitoring blood flow. A graphical information display includes simultaneously displayed depth-mode and spectrogram displays. The depth-mode display indicates the various positions along the ultrasound beam axis at which blood flow is detected. These positions are indicated as one or more colored regions, with the color indicating direction of blood flow and varying in intensity as a function of detected Doppler ultrasound signal amplitude or detected blood flow velocity. The depth-mode display also includes a pointer whose position may be selected by a user. The spectrogram displayed corresponds to the location identified by the pointer. Embolus detection and characterization are also provided.

Abstract: Reflectors such as microbubbles in a contrast agent introduced into a blood vessel of a patient are destroyed (or otherwise acoustically altered) using focused ultrasound at a modulation point according to an input modulation sequence. This creates “gaps” in the flowing contrast agent that are sensed at a downstream sensing point. The pattern of gaps is then matched in time with the input modulation sequence to determine a transit time for the gaps, which is also the flow velocity of the blood. The input modulation sequence creates at least two gaps, but may otherwise have any of several different forms, which include, among others, square-wave, maximal sequence, random binary patterns. Edge-detection and correlation techniques are used to match the input and sensed gap patterns. By triggering the input sequence off of a heart rate monitor, a flow velocity profile may also be calculated and displayed from one heart beat to the next.

Abstract: Methodology for determining the bounds of a patient's acoustic window is described. Medical application acoustic array designs with apertures accommodated by patient acoustic windows and merged acoustic windows are exemplified.

Abstract: A method and system for Doppler processing of information at two or more different frequency bands for improved accuracy is provided. Signals from two or more unique frequency bands are processed separately to detect motion. Using signals at different frequency bands allows for more effective use of unused bandwidth to increase information content and improve estimation accuracy. One of or more of the two or more receive frequency bands may be within the transmitted fundamental frequency band or within harmonic frequency bands of the transmitted fundamental frequency band. The increased information content generated by using two separate narrow receive frequency bands is used to improve many aspects of motion detection. The resulting Doppler values of each parameter, such as velocity, energy, and variance parameters, are averaged or otherwise combined. One of the average, the Doppler values at each frequency band and a null value are selected for further processing and display.

Abstract: Devices and methods according to embodiments of the invention measure physiological changes that occur in the female during sexual arousal. These include changes in clitoral, vaginal-artery, and/or vaginal-capillary blood flow, clitoral engorgement, and bioimpedance, to name a few. Feedback devices and methods assist a patient or medical professional to determine when arousal occurs and what its best triggers are for a particular patient. Overnight arousal-event monitoring, or other continuous monitoring over extended periods of time, either at home or away from home, allows diagnosis of vasculogenic impairment or other problems. The effects of medicinal therapies aimed at female sexual dysfunction can be quantified and used to titrate proper dosages. Embodiments of the invention provide objective, quantifiable measures of multiple physiological variables associated with female arousal, in a manner heretofore unseen in the prior art.

Abstract: A system and method are provided for determining the flow rate of blood in a vessel, such as a hemodialysis access. The system includes a conduit, such as an external dialysis circuit or an intravascular catheter, in communication with the blood in the vessel and having a diversion point for diverting the blood from the vessel into the conduit. As such, the vessel has a flow rate (QA) upstream from the diversion point and a flow rate (QD) downstream from the diversion point. A pump is connected to the conduit for diverting the blood into the conduit using a pump flow rate. An ultrasonic sensor is provided in communication with the blood in the vessel downstream from the diversion point. The ultrasonic sensor senses the downstream flow rate (QD) and generates at least two downstream Doppler frequency signals including a first downstream Doppler frequency signal when the pump has a first pump flow rate and a second downstream Doppler frequency signal when the pump has a second pump flow rate.

Abstract: An ultrasound color flow imaging system is programmed to optimize display images of power and velocity by automatically adjusting thresholds and data compression by using histograms and samplings of color flow data.

Abstract: A Doppler ultrasound clutter suppression system and method in which the clutter is first low-pass filtered (716) to suppress the flow component (4024) just before mean frequency estimation (718). The mean frequency is then estimated and mixed with the original clutter data which is positioned at DC. The low-pass filter bandwidth is predetermined based on the particular application and imaging parameters. The signal is then high-pass filtered (726) to remove the clutter component (4022).

Abstract: A method and an apparatus for segmenting three-dimensional projected velocity images by limiting the volume of velocity data projected onto the imaging planes. If the volume of interest contains flowing blood, i.e., an artery or vein, the Doppler shift present in the ultrasound reflected from the flowing blood can be detected and then used to limit the amount of velocity data which is projected. Only pixels having velocity values within a predetermined range are projected onto the imaging plane.

Abstract: An ultrasonic color flow mapping system and a filtering method for filtering an ultrasonic Doppler signal are provided. The ultrasonic color flow mapping system includes a forward processing portion for excluding initial output data up to a predetermined number from outputs based on an ultrasonic Doppler signal input having a predetermined index sequence, a backward processing portion for excluding initial output data up to a predetermined number from outputs based on the ultrasonic Doppler signal input having a backward index sequence with respect to the input of the forward processing portion, and an operator for calculating a power and an average frequency of the ultrasonic Doppler signal based on the outputs of the forward and backward processing portions and providing the calculated result as an output for image regeneration.

Abstract: An ultrasound color flow imaging system is programmed to optimize display images of power and velocity by automatically adjusting thresholds and data compression by using histograms and samplings of color flow data.

Abstract: An ultrasound color flow imaging system is programmed to optimize display images of power and velocity by automatically adjusting thresholds by using histograms.

Abstract: The invention relates to an ultrasonic echograph apparatus and method for locally determining biological data constituted by the time varying part of the blood pressure and the arterial wall compliance variations in function of the arterial radius variations, and includes the steps of measuring blood flow rate, arterial radius variation, and the mean arterial radius variation for two neighboring excitation lines and a hydrodynamic inductance. The method further includes steps of modelling, based on the measures, arterial wall behaviors by arterial wall stress-strain laws according to parametric relationships giving the biological data to determine, in the case of purely elastic or visco-elastic arterial behavior the parameters of the parametric relationships being related to the arterial dilatation and contraction phases over a whole cardiac cycle.

Abstract: A method for diagnosing malignancy in a tumor. A waveform representative of pulsatile blood flow in the tumor is measured, and the post-systolic portion of the wave form is fit with a mathematical function such as an exponential decay curve. A decay constant greater than about 48 pixels is diagnostic of malignancy.

Abstract: A three-dimensional image of flowing fluid or moving tissue using velocity or power Doppler data is displayed by using an ultrasound scanner that collects velocity or power data in a cine memory to form a volume of pixel data. Average or median pixel values are projected on an image plane by casting rays through the data volume. As the ray passes through each scan plane, a data value is assigned to the ray at that point. At each scan plane, the assigned pixel data value is tested to see if it exceeds a noise threshold. For a given ray, pixel data values above the detection threshold are accumulated until a pixel data value falls below the detection threshold. A minimum number of pixel data values exceeding the threshold are required for each ray before the average of the accumulated values is processed and/or the median value is selected. When all pixels along a given ray have been tested, the projection is complete and the average or median projection is then displayed.

Abstract: A method and apparatus for quantifying and displaying ultrasound signals in an ultrasonic system are provided. A first signal value for each of at least one spatial location in a region of interest is acquired at a first time, and the signal values are summed to obtain a first surface integral value. A second signal value for each of said at least one spatial location in said region of interest is acquired at a second time, and the second signal values are summed to obtain a second surface integral value. The first surface integral value is summed with the second surface integral value to obtain a time based integral. The time based integral is displayed. Other quantities based on any of various ultrasound parameters, such as Doppler energy, Doppler velocity and B-mode intensity, are calculated and displayed as quantities or as waveforms as a function of time. Furthermore, various comparisons of quantities and waveforms are provided. Image plane data or other ultrasound data are used in the calculations.

Abstract: Speckle is reduced in full motion ultrasound image data representing anatomic structures which have periodic physiological motion. Echoes produced from transmission of ultrasound energy into a subject's body are processed by an image frame acquisition device to produce a series of image frames for each physiologic cycle. Each image frame comprises data representing an image of a portion of the subject's body at a given time within the cycle. Successive image frames obtained at the same point in time within each physiologic cycle are filtered. The filtering is applied to each image frame within the entire current physiologic cycle, thereby deriving full motion speckle-reduced image data.

Abstract: Methods and apparatus for the remote coagulation of blood using high-intensity focused ultrasound (HIFU) are provided. A remote hemostasis method comprises identifying a site of internal bleeding and focusing therapeutic ultrasound energy on the site, the energy being focused through an intervening tissue. An apparatus for producing remote hemostasis comprises a focused therapeutic ultrasound radiating surface and a sensor for identifying a site of internal bleeding, with a registration means coupled to the radiating surface and the sensor to bring a focal target and the bleeding site into alignment. The sensor generally comprises a Doppler imaging display. Hemostasis enhancing agents may be introduced to the site for actuation by the ultrasound energy.

Abstract: An ultrasound color flow imaging system is programmed to optimize display images of power and velocity by automatically adjusting thresholds by using histograms and samplings of color flow data.

Abstract: A blood vessel puncturing device includes an ultrasound sensor which is brought into close contact with a subject body via an ultrasound propagation medium in the form of gel. The ultrasound sensor transmits and receives an ultrasound wave. The device further includes a processor which processes a signal derived from the ultrasound wave received at the ultrasound sensor so as to display an image of the subject body including a superficial blood vessel. While watching the displayed image, an operator sticks a puncturing needle at an angle of not greater than 30 degrees relative to the subject body along an ultrasound scanning surface of the ultrasound sensor and inserts the tip of the puncturing needle into the blood vessel.

Abstract: A method for automatic Doppler angle estimation based on the B-mode and color flow (if available) image. The method uses an algorithm for automatic vessel slope measurement which first finds an optimal initial point within the sample volume or range gate, and then searches for the most reliable pixel points (near or far walls) based on a combination of intensity-only and intensity-difference thresholds, before performing a slope estimation. B-mode intensity data and, optionally, color flow velocity or power data (before gray/color mapping) are used. The algorithm may also be applied to methods for automatic tracking of vessel diameter and flow rate calculations, although the primary objective is to achieve automatic Doppler angle estimation in an ultrasound scanner.

Abstract: A technique is disclosed for accurately tracing a maximum or minimum frequency in each of Doppler-shifted frequency spectra arranged in a sequential order of time on the time axis as an M-mode Doppler image. The maximum or minimum frequency is picked up by thresholding and hence the trace accuracy depends on a threshold. The threshold is determined based on the average brightness of a sample region in which noise is dominant. Therefore, the capability of discriminating between signal and noise components improves, allowing the trace accuracy to be improved.

Abstract: Methods and apparatuses for processing ultrasound signals. An approximation signal is generated to approximate an undesirable component of an input signal. The input signal may represent an ultrasound (e.g., Doppler) echo from a body. The approximation signal is used to remove the undesirable component from the input signal, leaving an output signal, which may be further processed by an ultrasound measurement and/or imaging system.

Abstract: An ultrasonic diagnostic imaging system and method are described by which a fundamental frequency signal is transmitted into the body and harmonic (nonlinear) echo returns are received from the transmission. The harmonic echo signals are Doppler processed and displayed. The harmonic Doppler signals may be displayed alone, or in combination with a fundamental frequency or harmonic grayscale image. In a preferred embodiment harmonic signals returned from moving tissue are segmented on an intensity or frequency basis and displayed. The inventive apparatus and method provide highly resolved ultrasonic images of moving tissue which are substantially unobscured by image clutter from structures or tissue in the near field.

Abstract: A method and system for generating data for a spectral Doppler strip in an ultrasound system includes a beamformer that provides Doppler data to a signal processor. The signal processor applies an autoregressive model and determines autoregressive parameters responsive to the Doppler data. Information responsive to the autoregressive parameters is generated, and a window function is applied to the information. At least one spectrum responsive to the autoregressive parameter is estimated with a Fourier transform.

Abstract: An ultrasound color flow imaging system is programmed to optimize display images of power and velocity by automatically adjusting thresholds and a color map by using histograms of color flow data.

Abstract: In an ultrasound system and method, a transducer connects to an estimator for obtaining first and second blood flow parameters associated with first and second scan line directions, respectively, in a first scan plane. One beam substantially covering a cross-sectional area of a tubular structure (uniform insonification) or a plurality of beams may be used. A first area associated with the cross-section of the tubular structure is also estimated from the blood flow parameters. The process is repeated for a plurality of scan planes. A processor determines the cross-sectional area of the tubular structure perpendicular to its axis (a second area), the average velocity of flow parallel to the axis, and the volume flow as a function of the first area and the first and second blood flow parameters of all the scan planes. For real-time volume flow, the orientation of the tubular structure is determined using the second area and the first and second blood flow parameters.

Abstract: Methods and apparatus for the remote coagulation of blood using high-intensity focused ultrasound (HIFU) are provided. A remote hemostasis method comprises identifying a site of internal bleeding and focusing therapeutic ultrasound energy on the site, the energy being focused through an intervening tissue. An apparatus for producing remote hemostasis comprises a focused therapeutic ultrasound radiating surface and a sensor for identifying a site of internal bleeding, with a registration means coupled to the radiating surface and the sensor to bring a focal target and the bleeding site into alignment. The sensor generally comprises a Doppler imaging display. Hemostasis enhancing agents may be introduced to the site for actuation by the ultrasound energy.

Abstract: According to one embodiment, an apparatus for measuring rotational velocity includes a support member, a transducer, and a Doppler shift measurement module. The transducer, which is supported by the support member, emits a first wave and detects a corresponding second wave reflected by matter intercepted thereby as the support member rotates continuously about an axis of rotation. The Doppler shift measurement module measures frequency shifting between the first wave and the second wave as the support member rotates about the axis of rotation, the frequency shifting being indicative of a rotational velocity of the support member relative to the matter.

Abstract: Temporal variations in backscatter from an ultrasound contrast agent located in the vascular system and induced by movement of the scatterers are used to visualize the presence of contrast agent by determining areas where correlation between successive ultrasound images is poor. This low level of correlation from intravascular contrast agent movement permits distinction between stationary bulk tissue and moving bulk tissue since movement of the latter solid tissue scatterers is correlated.

Abstract: The present invention provides electrosurgical needles, needle systems, and methods for their use which will allow the surgeon to target a tumor's blood supply. Generally, the invention facilities targeting the bloodflow of the tumor by incorporating a doppler ultrasound transducer into the needle or needle sheath. Preferably, the surgeon will also be able to control the temperature of the needle using an integral temperature sensor to effect maximum transfer of the RF energy into the tissue, thereby maximizing the volume of tissue destroyed. Furthermore, when used (for example) in the treatment of uterine fibroids, the present invention will reduce damage to the serosa by monitoring the uterine surface temperature during myolysis through a temperature sensor integrated into the sheath holding the myolysis needle.

Abstract: In an ultrasound system and method, a transducer connects to an estimator for obtaining first and second blood flow parameters associated with first and second scan line directions, respectively, in a first scan plane. One beam substantially covering a cross-sectional area of a tubular structure (uniform insonification) or a plurality of beams may be used. A first area associated with the cross-section of the tubular structure is also estimated from the blood flow parameters. The process is repeated for a plurality of scan planes. A processor determines the cross-sectional area of the tubular structure perpendicular to its axis (a second area), the average velocity of flow parallel to the axis, and the volume flow as a function of the first area and the first and second blood flow parameters of all the scan planes. For real-time volume flow, the orientation of the tubular structure is determined using the second area and the first and second blood flow parameters.

Abstract: A stent or graft stent energized from an external power source is provided with one or more sensors to sense a parameter, producing a signal that is transmitted outside a vessel in which the stent is implanted. At least a portion of a body of the stent or an insulated electrical conductor comprises a plurality of turns that serve as an RF antenna. An expandable mesh or helical coils that form the stent body may serve as the antenna or it may comprise a separate insulated conductor. The RF antenna receives energy electromagnetically coupled to the antenna from an external (or implanted) coil and conveys a data signal corresponding to the parameter sensed by the sensor(s) on the stent or stent graft to a monitor disposed outside the patient's body. In one form of the invention, a plurality of conformal array transducers are used to produce and sense ultrasonic waves that are affected by a fluid flowing through a lumen of the stent. This transducer determines fluid flow or fluid velocity.

Abstract: The present invention is directed toward a method for stimulating and/or monitoring hemodynamic activity, such as blood flow, in a penis. The method of the present invention comprises the coupling of an ultrasound source to the outer surface of the penis and transmitting ultrasound energy into the penis at a sufficient frequency and intensity to increase hemodynamic activity. An apparatus is also provided for practicing the method of the present invention. The apparatus provides for position adjustment of the ultrasound transducers during the circumferential expansion of the penis resulting from increased hemodynamic activity.