Abstract: An improved scan converter for converting received echo signals representative of the amplitude of ultrasound energy returning from sampled points along a plurality of spaced apart paths distributed in an image space into signals to be displayed as display pixels in a raster scan display system. The scan converter includes a scan data memory for storing the received echo signals in quadrants of the scan data memory. Each quadrant is associated with even and odd numbered paths and sample row combinations. Sample rows are related to sample points along the spaced apart paths. The scan converter further includes a circuit for determining a gray scale value to be assigned to each selected display pixel based on a predetermined combination of four received echo signals adjacent the selected display pixel and chosen from the quadrants of the scan data memory. The improved scan converter is capable of operation in both linear and sector scan modes, and, when in the sector mode, over 90.degree. and 180.degree.

Abstract: A fully wetted ultrasound scanhead for medical applications is described in which the motor and the rotor are enclosed within a sealed housing filled with ultrasound coupling fluid. The invention includes a drive belt to drive the rotor from the motor, rather than a precision drive means. Speed adjustment means, including an encoder disk mounted on the rotor, provide feedback for an electronic speed controller. Accordingly, the speed of the motor can be adjusted as a direct consequence of the actual speed of the rotor.

Abstract: The CRT is pivotally mounted in an enclosure which includes an integral camera. Photographs of the image on the screen of the CRT can be made by depressing the CRT and exposing the photograph.

Abstract: The present invention is a pump apparatus which is adapted to move liquids which contain debris. The apparatus is adapted to operate by alternating suction and pressure, whereby any debris which becomes lodged in any orifices or conduits in the system is effectively dislodged as a consequence of the normal operation of the system.The push-pull material transport system of the present invention includes a conduit to transport fluid from a first location to another location. The invention includes a peristaltic pump which has two heads. The first head pumps fluid from the first location to the second location, and the second head intermittently and periodically pumps fluid in the reverse direction in order to keep the conduit clear of debris.

Abstract: The present invention is a method and structure which produces extremely thin, electrically conductive epoxy bonds between two substrates. Copper microspheres, having an average diameter of about 2 microns are bound in an epoxy layer which bonds two substrates together. The microspheres make electrical contact between the substrates while providing intersphere gaps which are filled with the epoxy which actually bonds the substrates together.

Abstract: A scanhead for use in ultrasonic echo cardiography is described. The scanhead is particularly adapted for imaging a patient's heart from the patient's esophogus. The scanhead is comprised of a rotating base having a phased array or linear array scanhead mounted thereon, and the scanhead is rotated in order to change the cross-sectional plane of the heart which is intercepted by the ultrasound.

Abstract: Electronically changing the effective element spacing of an array of acoustic transducer elements between the transmit and receive modes of operation of an ultrasound apparatus results in reducing the deleterious effects of grating lobes present in the pattern of the array because of element spacings in excess of one half of a wavelength. A linear or quadratic time delay distribution, or both simultaneously, is applied to the array for scanning and/or focusing by setting individually the time delay of the energy associated with each element of the array during one mode of operation, e.g. transmit. The array is organized into groups of elements, e.g. pairs, and the time delay distribution is applied by setting the time delay of the energy associated with each group of the array during the remaining mode of operation, e.g. receive.

Abstract: The device uses two Doppler receivers having different center frequencies. After the mean Doppler frequency of each receiver is determined, one of the mean Doppler frequencies is subtracted from the other one of the mean Doppler frequencies, thereby providing the mean Doppler frequency associated with a frequency which is equal to the difference between the two original frequencies.

Abstract: The scanhead uses a shaft mounted, oscillating rotor driven by a shaft mounted rotor. Energy storage and repulsive means, provided by magnetic "bumpers" helps to reverse the direction of motion of the rotor at the end of the scan angle.

Abstract: A probe for testing ultrasound transducers is described. The probe is made of a body of material which absorbs ultrasound. There is a conical opening in the body, and a spherical transducer is mounted in the wider opening at the base of the conical opening. When the probe is used as a surface probe, a transducer undergoing tests is placed at the opening at the apex of the cone. Typically the conical opening is filled with a fluid which simulates the absorption qualities of the material with which the tested transducer will ultimately be used. For example, the transducer undergoing the test will be used with human body tissue, so a fluid such as water or light mineral oil would typically fill the cone-shaped opening. The present invention can also be used as a hydrophone, because of the manner in which it generates, or senses, pressure waves at a point in space.

Abstract: A bubble trap for use with an ultrasonic scanhead is described. The bubble trap is comprised of a reservoir chamber connected to the main chamber housing the ultrasound transducer. The reservoir chamber is connected via a channel which extends from the main chamber to an orifice in the volumetric center of the reservoir chamber. Thus, any bubble which flows up through the orifice into the reservoir chamber will be trapped there, and will thereby be removed from the main chamber.

Abstract: A needle guide for use with a medical ultrasonic scanning apparatus includes a pivoting plate on a fixed mounting plate. The mounting plate is attached to an ultrasonic scanhead whereby a surface of the mounting plate is in the plane of the ultrasound scan. An adjustable pivoting plate on the mounting plate includes at least one needle aligner, which preferably has a groove formed therein. The pivoting plate can be pivoted and locked into position on the mounting plate. An idler plate, containing an idler roller is spring mounted on the pivoting plate. The idler plate can be pivoted, whereby the idler roller moves away from the guide needle aligners. A raised wall on the pivoting plate prevents an improperly placed needle from puncturing a sterile sheath applied over the scanhead, such as in a brain scan. Thus a needle, such as a biopsy needle can be placed between the idler roller and the needle aligner and will be held in place by the spring tension on the idler roller.

Abstract: The invention is a fiber-optic endoscope which has an elongated ultrasonic array, such as a linear array or a phased array. The array is mounted on either the distal portion of the bending section (not under operator control) portion of the endoscopic tube or on the proximal portion of bendable portion of the tube. Thus, the present invention includes both a fiber-optic endoscope and an ultrasonic transducer. Yet, the presence of the ultrasonic transducer does not interfere with the operation of the placement of the fiber-optic probe.

Abstract: The wide dynamic range ultrasound receiver utilizes a multi-stage logarithmic amplifier in order to logarithmically amplify a returned echo signal. The output of the returned echo signal from the logarithmic amplifier is simply added to a saw-tooth wave Time Gain Control (TGC) signal. Thus, the wide dynamic range of the returned echo signals is simply converted into a video display.

Abstract: The scanhead includes an impeller which is designed to swirl the liquid adjacent the ultrasound transducers as the transducers are rotated. The fluid dynamics established by the swirling liquid cause any bubbles within the liquid to be forced to the center of the swirling liquid where they are out of the zone of transmitted or received ultrasound energy. When an impeller having multiple vanes with an opening formed therebetween is used, the bubbles are forced to the center of the impeller.

Abstract: A scanner includes a scan head having a linear array of transducers Xn, and a transmitter 106 which excites the transducers in response to transmit signals TRn from a reference generator 110 so that the transducers emit a plurality of successive bursts of ultrasonic energy, each burst producing a transmitted beam which is steered and focused along a radially-extending scan line. To effect received beam steering and focusing, received signals Sn from the transducers are supplied to a processor 112 along with associated in-phase binary reference signals bn(R) and quadrature binary reference signals bn(I). The received signal is multiplied by a reference signal and the product is integrated for a specific time duration whose time occurrence is used to steer and focus the beam.

Abstract: A digital scan converter is disclosed wherein signal information supplied by a sector scanning surveillance system relative to a polar coordinate system is converted to a signal for driving a television-type display or other Cartesian coordinate device by: (a) sampling the signal associated with each consecutive scanning path of the surveillance system at a rate determined by the azimuthal angle that defines the scanning path of interest; (b) storing each set of signal samples as a column of data in a rectangular memory array; (c) accessing the stored data on a row-by-row basis; and (d) utilizing a previously determined mapping strategy to cause each accessed signal sample to form a segment of a line of display within the Cartesian-formulated display devices so that the length of the segment formed by each signal sample is determined by the row and column address of the storage location that is associated therewith when forming a television compatible signal, each signal sample dictates video signal level dur

Abstract: A digital scan converter is disclosed for processing the sequence of analog signals supplied by a sector scanning surveillance system to form a signal compatible with television type display devices. The signals supplied by the surveillance system are digitized by an analog-to-digital converter at a rate proportional to the cosine of the azimuthal scan angle that is associated with each analog signal to thereby effect a first portion of the required conversion from the polar coordinate format of the surveillance system to the Cartesian coordinate format of the television display. The digitized signals are stored in a memory so as to permit addressing of a set of stored data that corresponds to one horizontal trace of the television display.

Abstract: A method by which particle separation is accomplished by taking advantage of the large difference in the diffusion rates between the ionized and neutral components of a gaseous mixture, in the presence of a magnetic field. Means for separating isotopes in a continuous and commercially successful manner. Apparatus in which the desired component is selectively ionized, accelerated and guided by a magnetic field along a predetermined axis, while the neutral particles are transversely removed by means of vacuum or cryogenic pumps.