Abstract: Disclosed herein are ultrasound transducers that are selectively insulated to thereby enable the transducers to be exposed to an electrically conductive fluid without causing a short circuit between electrodes of the transducers. Such a transducer includes a piezoelectric transducer body having a first surface and a second surface that are spaced apart from one another and do not intersect with one another. The ultrasound transducer also includes a first electrode disposed on the first surface, a second electrode disposed on the second surface, and an electrical insulator covering only one of first and second electrodes and configured to inhibit electrical conduction between the first electrode and the second electrode when the ultrasound transducer is placed within an electrically conductive fluid. Also disclosed are apparatuses and systems that include such a transducer. Related methods are also disclosed herein.

Abstract: A catheter assembly for an ultrasound system can include an integrated pullback arrangement. For example, the catheter assembly can include a telescoping pullback section having a first telescope, a second telescope, a distal grip coupling one of the first or second telescope to the distal sheath of the distal section, and a proximal grip coupled to another of the first or second telescope so that the first telescope can be retracted into the second telescope and a sensor to determine a position of the first telescope. Another example includes the sensor and a pullback slider arrangement having a housing defining a slit, a coupler disposed within the housing, and a slider handle extending through the slit and coupled to the coupler. In another example, the coupler and housing can be gripped and slid relative to each other.

Abstract: A method for real-time displaying of cross-sectional images during an intravascular ultrasound (IVUS) imaging procedure includes, during an intravascular ultrasound imaging procedure, receiving electrical signals from at least one transducer in a catheter as the at least one transducer rotates and moves longitudinally along a lumen of a patient blood vessel; during the intravascular ultrasound imaging procedure, processing the received electrical signals to form a series of cross-sectional images that are longitudinally-offset from one another along a length of the lumen; during the intravascular ultrasound imaging procedure, concurrently displaying i) a most recent image and ii) a previous image that is either a) selected by the operator or b) automatically selected as having a maximum or minimum of a selected image characteristic; and, during the intravascular ultrasound imaging procedure, updating the display of the most recent image as a new image from the series of cross-sectional images is processed.

Abstract: A catheter assembly for an ultrasound system can include an integrated pullback arrangement. For example, the catheter assembly can include a telescoping pullback section having a first telescope, a second telescope, a distal grip coupling one of the first or second telescope to the distal sheath of the distal section, and a proximal grip coupled to another of the first or second telescope so that the first telescope can be retracted into the second telescope and a sensor to determine a position of the first telescope. Another example includes the sensor and a pullback slider arrangement having a housing defining a slit, a coupler disposed within the housing, and a slider handle extending through the slit and coupled to the coupler. In another example, the coupler and housing can be gripped and slid relative to each other.

Abstract: Techniques are disclosed for pacing site selection. In one example, a method includes using a sensing element such as an ultrasonic transducer, an optical pressure sensor, a MEMS pressure sensor, a SAW pressure sensor, an accelerometer, a gyroscope, or any other suitable sensing element to sense a measure related to a cardiac strain in a heart resulting from contraction and relaxation of myocardium during a cardiac cycle. Based on the sensed strain, an output may be provided for use by a user of the system to select a segment of the heart for lead placement.

Abstract: In k31 mode, a vibration is along an axis or orthogonal to the poling or electric field orientation. The direction of vibration is toward a face of an ultrasound transducer array. For each element of the array, electrodes are formed perpendicular to the face of the array, such as along the sides of the elements. Piezoelectric material is poled along a dimension parallel with the face of the transducer and perpendicular to the direction of acoustic energy propagation. Using elements designed for k31 resonant mode operation may provide for a better electrical impedance match, such as where small elements sizes are provided for a multi-dimensional transducer arrays. For additional impedance matching, the elements may be made from multiple layers of piezoelectric ceramic. Since the elements operate from a k31 mode, the layers are stacked along the poling direction or perpendicular to a face of the transducer array for transmitting or receiving acoustical energy.

Abstract: In one embodiment, a medical image viewer in compliance with a medical image standard is provided, and a file in compliance with the medical image standard is provided to the medical image viewer. The medical image standard specifies a first field for data not in compliance with the medical image standard and a second field for data in compliance with the medical image standard. The first field of the file comprises medical image data, and the second field of the file comprises information that can be used to obtain software to at least one of display and manipulate the medical image data. The software is obtained, and at least one of the following is performed with the software: displaying the medical image data and manipulating the medical image data. Other embodiments are provided, and each of the embodiments described herein can be used alone or in combination with one another.

Abstract: A diagnostic medical imaging system is disclosed, such as a diagnostic medical ultrasound system, which uses operational rules or an anatomic model of an anatomical structure as an organizational framework for applying anatomy-specific auxiliary/secondary information. After processing the operational rules on the acquired images or associating the model with the acquired images, adapting/fitting the model to match the images if necessary, the imaging system can associate aspects of the images being acquired with the auxiliary/secondary information, allowing the imaging system to behave as if it “knows” what it is scanning. The auxiliary information may be rules that affect the behavior of the imaging system, or may be the acquired image samples. System behavior may then be automatically adapted or the operator may be prompted to make operational changes.

Abstract: An improved two-dimensional ultrasonic transducer array is provided by forming a plurality of elongated transducer strips each including a central body of piezoelectric material having mounted thereon a conducting inner matching layer and outer matching layer, a conducting inner backing layer and a nonconducting lossy outer backing layer, depositing a conducting film on the outer surface and one side surface of the outer matching layer and into electrical contact with the conducting backing layer of each strip and depositing a plurality of conducting films in space relation to one another on the back surface and one side surface of the lossy backing layer and into electrical contact with the conducting backing layer to provide an electric circuit to the front and back faces of the piezoelectric layer.

Abstract: A phased array sector scanning ultrasonic imaging system includes a transducer array with 2N separate transducer elements and a transmitter and receiver with N separate channels. The complete 2N element aperture is realized at each beam angle with two firings of the transmitter and the receipt of echo signals from two different sets of N transducer elements. The echo signals from the two firings are coherently summed to form a single receive beam. Two different patterns are provided for selecting which transducer elements to energize and receive from during each of the two firings.

Abstract: Apparatus for echo mode imaging of a blood vessel is disclosed having a plurality of transducers that transmit a substantially unfocused omni-directional signal in at least one plane towards the vessel. The reflected signal is received and transmitted in time multiplexed form to an Analog-to-Digital converter. Thus the required number of interconnecting wires is reduced. A method for imaging a blood vessel comprises transmitting an unfocused signal in a substantially omni-directional manner in at least one plane, receiving reflections from the vessel, and transmitting the received signals in time multiplexed form for imaging.

Abstract: A catheter based ultrasound imaging system is disclosed which is capable of providing images of coronary vessels at frequencies near 50 MHz. The catheter based system implements a Synthetic Aperture Focusing Technique (SAFT) by scanning through a miniature ultrasound transducer array to sequentially select and fully multiplex a subset of array elements to operate as a sub-aperture of the total synthetic aperture on each firing; thus reducing the number of required catheter interconnections. Each synthetic aperture array is dynamically and retrospectively focused to accommodate precision imaging at high frequency without conventional signal to noise losses.

Abstract: A microfocus X-ray tube has an anode that emits X-rays and, a biproduct of its waste heat, visible and near infrared light. This invention uses the biproduct light to adjust and maintain the focus of the electron beam and enhance the performance of the X-ray tube as a point source of X-rays. Only the light is reflected by a mirror along a path in which a viewport is placed in the tube envelope. An sensor, e.g., a photodiode, or television camera, is placed in the path. A display means, e.g., a television display, meter, etc., can be connected to the sensing means to display the emitting spot of the anode or the amplitude of the emission. The focus of the X-ray tube is assured by observing the biproduct light and adjusting the electron beam to either minimize the size of the glowing spot or maximizing its apparent brightness. A method for use with an emitter of first and second types of radiation comprises reflecting only the second type of radiation, and sensing the reflected radiation.

Abstract: An apparatus for monitoring the curing of a fiber reinforced composite plastic which is cured at temperatures of the order of 350.degree. C. and an ultrasonic transducer assembly useful in the apparatus. The transducer assembly comprises a lithium niobate piezoelectric element having anisotropic coefficients of thermal expansion which is mounted on a metal base of the transducer assembly by means of a layer of structured copper. The structured copper is thermo-compression diffusion bonded to the lithium niobate element and to the metal base, and is compliant in a transverse direction to compensate for differential thermal expansions while affording good electrical and thermal conductivity and good acoustic coupling between the lithium niobate element and metal base.

Abstract: A broadband 25 to 50 MHz spherically focused ultrasonic transducer is placed on the tip of a catheter such that ultrasonic images of arteries and plaque are produced by introducing the catheter into arteries of patients. The high frequency transducer has thin piezoelectric polymer film as the transducing element and is adhered to a depression in the reduced cross section catheter tip. A coaxial cable in the catheter connects the transducer to an external signal source and a display for the received signals. The diagnosis and characterization of arterial disease is most often coupled with a therapeutic technique such as balloon angioplasty.

Abstract: Apparatus for deriving signals indicating a condition of tissue within an area by launching spaced supersonic pulses into a body under examination and detecting the power of supersonic waves scattered from locations along a plurality of known paths. Gain control elements are provided for compensating for changes in amplitude of the scattered supersonic waves resulting from their passage through blood or tissue, the increased attenuation with frequency of the spectrum of the launched pulses and the focussing of the launched pulses. Compensation for ring-down and the attenuation of the chest wall is also provided.

Abstract: An imaging X-ray sensor is composed of a linear array of microscopically small bars of polycrystalline ceramic scintillator material bonded at the bar ends to an integrated circuit photodetector array. The scintillator bars are the basic resolution elements of the detector and are less than 50 microns in width. Each bar produces a flash of light with intensity related to the X-ray flux penetrating the bar. A reflective coating covering five surfaces of the bars isolates each detector element and channels the light into the photodetector bonded to one end of the bar. A method of fabricating the detector array utilizes the machineability and good mechanical strength of scintillators such as rare earth oxides doped with rare earth activators.

Abstract: An apparatus for monitoring the curing of a fiber reinforced composite plastic which is cured at temperatures of the order of 350.degree. C. and an ultrasonic transducer assembly useful in the apparatus. The transducer assembly comprises a lithium niobate piezoelectric element having anisotropic coefficients of thermal expansion which is mounted on a metal base of the transducer assembly by means of a layer of structured copper. The structured copper is thermo-compression diffusion bonded to the lithium niobate element and to the metal base, and is compliant in a transverse direction to compensate for differential thermal expansions while affording good electrical and thermal conductivity and good acoustic coupling between the lithium niobate element and metal base.

Abstract: Changes in the ultrasonic properties of fiber-reinforced plastics during the curing process are monitored by a marginal oscillator to determine the degree of cure. The plastic sample and transmitting and receiving transducers serve as a narrowband acoustic resonator and are placed in the feedback loop of a variable gain amplifier; using gain control the system is allowed to marginally oscillate. The resonant frequency of the sample and amplifier gain are related to the velocity and attenuation of sound in the plastic and are determined by measuring the received signal frequency and amplifier gain control voltage. The system has frequency locking means to track changes in resonant frequency during the cure cycle.