Abstract: A system and method for ultrasonic harmonic imaging of both tissue and tissue perfused with a contrast agent are disclosed. The ultrasonic harmonic imaging system comprises a wideband phased-array transducer, a transmitter for transmitting waves into the tissue, a receiver for receiving ultrasonic responses from the tissue, a control system electrically coupled to the transmitter and the receiver for controlling operation of the transmitter and receiver, a video processor, and a monitor. In a preferred embodiment, the transducer insonifies tissue at a fundamental frequency of less than approximately 1.5 MHz. A method for detecting an ultrasonic harmonic response of a contrast agent may be performed by introducing at least one contrast agent into the target object, destroying the contrast agent with an ultrasonic pressure wave and measuring the harmonic response from the destroyed contrast agent.

Abstract: The concentration and/or radii of a contrast agent in a fluid can be estimated by acquiring ultrasound spectral data, performing spectral analysis to generate a linear estimation of the power spectrum, and correlating at least one spectral parameter to a predetermined distribution function for the contrast agent. If the mean radius squared of particles is known, then the concentration of contrast agent particles can be calculated. If the concentration is constant, then relative variations in mean radius squared can be determined.

Abstract: In a high-resolution flow mode, a diagnostic ultrasound apparatus and a diagnostic ultrasound method that provide an image of blood flow or perfusion is provided with higher sensitivity and high resolution, which makes it possible to precisely observe the presence of fine blood vessels. In this apparatus, by scanning means (81 to 83), with a ultrasound pulse having a wideband frequency characteristic transmitting at least two times in the same direction within an object, a cross section to be imaged therein is scanned to obtain an echo signal at each time of transmission. By processing means 84, highpass filtering or differential processing is performed with rows of data in the time axis direction of an echo signal acquired at each sample location in the cross section, so that signals from blood flow are extracted. By producing means 85, the processed signals are produced into data of luminance or power.

Abstract: Rotating element catheters and catheter assemblies employ clutch assemblies for preventing rotational energy from being transmitted from a motor drive unit to the catheter element under defined circumstances. The catheter assembly includes an elongate member in which there is disposed a rotatable catheter drive cable. The catheter drive cable may have an operative element, e.g., an ultrasonic transducer or an artherectomy blade, distally mounted thereon for providing diagnostic or therapeutic functions to the physician. To control the rotation of the catheter drive shaft, the clutch assembly is configured such that the catheter drive shaft is operated in a drive mode (i.e., it is allowed to rotate) and in a release mode (i.e., it is prevented from rotating).

Abstract: A three-dimensional projection image representing a projection of a data volume at a predetermined orientation, three cut plane images representing respective mutually orthogonal planar cuts through the data volume, a graphical representation of the data volume at that orientation and graphical representations of the cut planes are displayed in spaced relationship. Each of the cut planes has a respective positional relationship to the data volume graphic that corresponds to the positional relationship of the respective cut plane to the data volume. The graphical representations are displayed in different colors. Any one of the four images can be active in the sense that images are reconstructed in real-time as a trackball is moved. Which of the four images is active is indicated by displaying the corresponding graphical representation in a color denoting the active state.

Abstract: An ultrasonic probe (10) for measuring the depth of detachment between a tooth (30) and the tooth's supporting tissue includes a probe head (12) having an ultrasonic transducer (35). An incident acoustic wave pulse (50) is transmitted through a coupling medium at a critical angle of incidence for refraction at the interface between the coupling medium and the tooth surface (29, 31) to effect modal conversion to a surface acoustic wave pulse along the surface of the tooth (30). The critical angle of incidence is established by means of an angular setting of the ultrasonic transducer (35) in the probe head (12), a combination of the aforementioned angular setting with the ability to rock the probe head (12) to find the critical angle of incidence, and/or a phased array implementation. The disclosure also includes an algorithm for determining the depth of detachment based on the time lapse between transmission and detection of the reflection of the acoustic wave pulses.

Abstract: An ultrasound transducer assembly includes an acoustic mirror, an ultrasound transducer positioned to direct a scanned ultrasound beam at the acoustic mirror, wherein the scanned ultrasound beam is reflected by the acoustic mirror to form a reflected ultrasound beam, and an actuating device for moving the acoustic mirror relative to the scanned ultrasound beam so that the reflected ultrasound beam scans a three-dimensional volume. An ultrasound matching fluid may be disposed between the ultrasound transducer and the acoustic mirror. The actuating device may be configured for rotating the acoustic mirror, translating the acoustic mirror or rotating and translating the acoustic mirror. The acoustic mirror may have a single acoustically-reflecting surface of may be a polygon having a plurality of acoustically-reflective surfaces.

Abstract: A transducer system and method for harmonic imaging is provided. At least one transducer element is provided. The transducer element comprises two stacked piezoelectric layers. Information from each of the layers is independently processed during one of a transmit event, a receive event, and both transmit and receive events. Information from the transducer element is provided to a filter. The filter isolates harmonic information for imaging. By providing a multi-layer transducer element with independent processing for each layer, a wide bandwidth transducer for harmonic imaging is provided. The null associated with most transducers at the second harmonic of a fundamental frequency is removed or lessened.

Abstract: A method for receiving Doppler ultra sound signals at a high sample rate, at greater depths and from a large range gate size by increasing the length of time during which echoes can be received with respect to the time required to transmit the Doppler pulses that cause the echo signals to be created. According to a first embodiment of the invention, a Doppler pulse is transmitted for a time equal to the time required for an ultrasonic sound wave to travel from a transducer to a top of a range gate and back. Echo signals created in response to the long Doppler pulse are received for a time equal to the transmit time plus the time required for an ultrasonic sound wave to travel from the top of the range gate to a bottom of the range gate and back to the top of the range gate.

Abstract: A color imaging display method and apparatus in a color doppler imaging system can display a high quality of a color image in which a flash artifact which is a kind of a clutter signal is removed. The method and apparatus determines whether the flash artifact exists, according to the result obtained by frequency-estimating a doppler signal where an ultrasonic signal is filtered and a clutter signal where the ultrasonic signal is not filtered, and mixing the information obtained through the frequency estimation, and determines whether or not a corresponding pixel is displayed in an ultrasonic color doppler image. Thus, the pixel which has been determined as the flash artifact is not displayed, to thereby obtain a high quality of a color image.

Abstract: The ultrasound probe cover includes a conventional condom which is adapted to fit over an ultrasound probe. The cover is secured to the probe in a water-tight arrangement at the proximal end of the cover by an elastic band. An elongated hollow tube is secured to the surface of the ultrasound probe, which tends to result in an equalization of fluid pressure at both ends of the condom cover during insertion and retraction of the condom into and out of a bodily opening, such as the rectum, of a patient.

Abstract: A method for detecting a relative level of a contrast agent in a region of a body, where the contrast agent is susceptible to destruction by a destructive ultrasound signal. The method comprises the steps of: determining a signal level from a first ultrasound echo that is produced in the region during a first time, which occurs while the contrast agent is present in the region; determining a signal level of a second ultrasound echo that is produced in the region during a second time, which occurs after destruction of the contrast agent; and determining a ratio of the signal level from the first ultrasound echo and the signal level from the second ultrasound echo, where the ratio indicates a relative level of the contrast agent during the second time as compared to the first time.

Abstract: A parametric imaging ultrasound catheter apparatus is capable of obtaining parametric images of the surrounding insonated environment. Parametric imaging is defined as the imaging of quantifiable “parameters” which of visible two-, three-, fourth-dimensional or non-visible higher-dimensional temporal physiologic events. Visible motion is a fourth-dimensional event and includes surrogate features of cardiac muscle contraction, wall motion, valve leaflet motion, etc. Non-visible motion is a higher-dimensional event and includes slow non-visible events (i.e., remodeling, transformation, aging, healing, etc.) or fast non-visible events (i.e., heat, electricity, strain, compliance, perfusion, etc.). An ultrasound catheter with parametric imaging capability can obtain dynamic digital or digitized information from the surrounding environment and display information features or quanta as a static or dynamic geometric figures from which discrete or gross quantifiable information can be obtained.

Abstract: An apparatus and method for recording ultrasound images of a moving object is disclosed. The apparatus includes an ultrasound transmitter, an ultrasound receiver, and an image processor. At least one of the ultrasound transmitter and receiver is moved in relation to an object. Images of the object are acquired, and a movement state of the object is determined and classified into one of two movement states. Based on the movement state of the object, images are either not acquired, or not processed. If the image of the object is not processed, the image processor filters out the images which were acquired during a movement state of the object when the movement is high. The image processor then assembles the images and displays the assembled images.

Abstract: A combination catheter includes an ultrasound transducer and RF ablation electrode. The ultrasound transducer transmits ultrasound signals into and receives echo signals from a vessel. The echo signals are processed and used to produce an image of the tissue surrounding the catheter. A driveshaft rotates the ultrasound transducer to obtain a 360° view of the vessel wall. At the distal end of the driveshaft is an electrode. An RF generator is electrically coupled to the driveshaft to deliver RF energy to the electrode at the distal end of the driveshaft to ablate occluding material in the vessel. The electrode may have a variety of tip shapes including concave, roughened, or expandable configurations, depending on the size of the vessel and composition of the occluding material to be ablated. Alternatively, the RF ablation energy may be delivered to a guidewire that is used to route the ultrasound catheter through a patient's vasculature.

Abstract: An ultrasonic diagnostic imaging system is used to produce spatially compounded ultrasonic images with beams transmitted in multiple look directions from a curved array scanhead. The beam steering is a function of both the curvature of the curved array and electronic beam steering. The beams may be steered in groups of parallel beams, or in groups which have a common angular orientation to their points of origin along the array. The describe embodiments provide advantages in beamforming and registration coefficient usage, sampling uniformity, speckle reduction uniformity, and a larger area of maximum compounding effect.

Abstract: In an imaging method and a system for determining a physical or chemical condition of tissue in a human or animal body using ultrasound at least one ultrasonic pulse in the diagnostic frequency and power range is injected into the tissue. The ultrasonic echo pulse reflected by the tissue is received and processed in ultrasonographic trace processing means. Further, at least one light beam is generated and split up into at least one measuring light beam and at least one reference light beam. The measuring light beam is injected along the same beam axis along which the ultrasonic pulse is injected into the tissue. The measuring light beam scattered back by the tissue is brought into an interference relationship with the reference light beam and is processed in optical image processing means.

Abstract: An ultrasound transducer having transducer elements arrayed in a polygonal shape on a common plane. The polygonal array of transducer elements includes a core unit consisting of a single transducer element of a polygonal shape and a plural number of frame units each consisting of a plural number of transducer elements arranged in a polygonal shape around the transducer element of the core unit. Each one of the transducer elements of the frame units are formed in the shape of a square block and electrically connected to adjacent transducer elements of the same frame unit but insulated from transducer elements of an adjacent frame unit through an insulating coat layer.

Abstract: A hand held ultrasonic instrument is provided in a portable unit which performs both B mode and Doppler imaging. The instrument includes a transducer array mounted in a hand-held enclosure, with an integrated circuit transceiver connected to the elements of the array for the reception of echo signals. A digital signal processing circuit performs both B mode and Doppler signal processing such as filtering including wall filtering matrix and Hartley transform matrix functions, detection and Doppler estimation, as well as advanced functions such as assembly of multiple zone focused scanlines, synthetic aperture formation, depth dependent filtering, speckle reduction, flash suppression, and frame averaging. The advent of color flow imaging based on Doppler frequency estimation in medical ultrasound addresses a need for rapid assessment of overall flow characteristics in cardiac care.

Abstract: A surgical instrument navigation system comprises an ultrasound machine and a computer coupled to the ultrasound machine. A memory is coupled to the computer and includes computer instructions that when executed by the computer cause the computer to generate an icon representing the surgical instrument with a tip and the surgical instrument's trajectory and to overlay the icon on a real-time ultrasound image having an image plane, such that when the surgical instrument crosses the ultrasound image plane the format of the surgical instrument's trajectory is changed to represent the surgical instrument's crossing of the ultrasound image's plane. The system also comprises a localizer coupled to the ultrasound machine, and a display coupled to the computer for displaying the generated icon superimposed on the real-time image.