Abstract:
In a capacitive membrane ultrasound transducer, one or more electrodes include multiple layers of conductive or semiconductive material. The layers may be positioned adjacent an insulator or cavity in an arrangement to reduce electrical degradation. For example, a conductive layer with less work function and less resistivity is spaced from an insulator by a conductive layer with more work function and more resistivity. The different layers of electrode material may provide for less electrical degradation due to the type of material used and relative location.
Abstract:
An ultrasound imaging system may use a capacitive membrane or electrostrictive ultrasound transducer to realize isotropic volumetric imaging with bias-line element selection and a variety of aperture synthesis techniques. Two dimensional beam formation may be performed by using a beamformer to focus along one dimension, and then perform a second round of “off-line” or “retrospective” beam formation along the other direction.
Abstract:
An ultrasound imaging system may use a capacitive membrane or electrostrictive ultrasound transducer to realize isotropic volumetric imaging with bias-line element selection and a variety of aperture synthesis techniques. Two dimensional beam formation may be performed by using a beamformer to focus along one dimension, and then perform a second round of “off-line” or “retrospective” beam formation along the other direction.
Abstract:
A light-weight display easel assembly for use with photographs and photographic greeting cards is described, wherein the display device is a substantially planar sheet or panel of paperboard or similar cellulose-containing material having a plurality of die-cut flaps thereon, each of the die-cut flaps having one scored edge which allows for the outward folding of the flap. The display easel further comprises a plurality of adhesive strips on the front face of the paperboard, for attachment of a photograph or photographic greeting card thereto. The display easel, once assembled, is lightweight enough such that it can be mailed without the need for excess postage fees. Additionally, due to the attachment of the display easel to substantially the entire back face of a photograph, the entire photograph is fully supported and is therefore resistant to creases, indentations, warping, and other damages which can occur during the mailing process.
Abstract:
Presented is a method of operating a capacitive microfabricated ultrasonic transducer (cMUT) array with multiple firings of varying bias voltage polarity patterns to improve its performance in imaging non-linear media, such as in contrast agent imaging or tissue harmonic imaging. Additionally, transducers incorporating the method are provided. The method of cMUT operation and the corresponding cMUT does not require pre-distortion or phase inversion of the transmit signal and can achieve an improvement in the elevation focus of the cMUT, as compared to the elevation focus that a single firing can achieve. Further, the method of operating the cMUT minimizes the deleterious effects that result from insulators being subjected to high electric fields.
Abstract:
An electrostatic transducer circuit and method of tuning the same, in which a balancing circuit is inserted into the electrostatic transducer circuit, is described. The electrostatic transducer circuit generally includes transmit circuitry, receive circuitry, a capacitive electrostatic transducer and the balancing circuit. The balancing circuit can include, either singly or in combination, an inductance and a negative capacitance. The balancing inductance is tuned to counteract the negative reactance of the capacitive electrostatic transducer at a desired operating frequency and can be inserted into the transmit circuitry and/or the receive circuitry. The balancing negative capacitance is tuned to counteract the capacitance of the capacitive electrostatic transducer and can be inserted into the receive circuitry and/or the transmit circuitry. The transmit circuitry can be isolated from the receive circuitry, and vice versa, once the balancing circuit has been inserted. Isolation can be achieved by switching the electrostatic transducer circuit between transmit and receive modes of operation, or by providing separate transmit and receive electrode subsets.
Abstract:
A CMUT or other semiconductor-based transducer is stacked with a piezoelectric transducer (PZT). The CMUT is sufficiently thin to avoid or limit interference with sound propagation through the CMUT from or to the PZT or crosstalk between transmitter elements. The PZT/CMUT layered structure is used as a matrix array, such as an array with a multi-dimensional arrangement of elements. The CMUT array is formed and thinned using semiconductor processing. The PZT transmits acoustic energy through the thin CMUT. The CMUT receives responsive echoes. Using integrated electronics in the thin wafer of the CMUT limits interconnection problems for the matrix receive array.
Abstract:
An autonomous vehicle for operating in a predetermined work area while avoiding both fixed and moving obstacles. A plurality of laser, sonic and optical sensors detect targets and obstacles in the work area and provide coded signals to processors and controllers which direct the vehicle over a most expedient route to a target while avoiding any obstacles. The vehicle is especially useful in moving around the deck of an aircraft carrier to deliver ammunition to aircraft from an ammunition magazine.
Abstract:
Apparatus and methods are provided to create high dynamic range images by passing an incoming image through a color-neutral separation prism having at least three channels to produce a corresponding number of full color fractionated images, each channel aligned with a corresponding image capturing device for which an ISO sensitivity is selected to simultaneously achieve a different exposure value for each fractionated image and image capturing device, referred to as exposure bracketing, and recombining the simultaneously collected fractionated images to create a high dynamic range image. The apparatus and methods may be used for still photography or motion pictures.