Abstract: A system for overriding an EMD locomotive engine protective device which includes a low water pressure sensing device in communication with the engine cooling system for shutting down the engine when low water pressure in the engine is sensed, the override system comprising a water assist pump connected to a source of water and communicating with the protective device for supplying pressurized water to the low water pressure sensing device to maintain relatively high water pressure to prevent the device from shutting down the engine; and a controller for activating the water assist pump during start up of the engine.

Abstract: Methods and systems for isolating transmit and receive circuitry at an ultrasound transducer element are provided. Separate electrodes or electrodes on opposite sides of a transducer element are connected to the separate transmit and receive paths or channels. Instead of high voltage transmit and receive switching, the transducer element isolates the transmit channel from the receive channel. The transmit channel includes circuitry for limiting the voltage at one electrode during receive processing, such as a switch operable to connect the electrode to ground. The receive channel includes circuitry for limiting the voltage at an electrode during transmit processing, such as a diode clamp preventing voltage swings greater than diode voltage at the electrode. Limiting the voltage provides virtual grounding or a direct current for either of the transmit or receive operation.

Abstract: A segmented ultrasound system is provided. Ultrasound data, such as image data in a video format, is wirelessly transmitted to a multi-use display device from a handheld ultrasound device. Any of various multi-use display devices may be used, such as personal digital assistants (PDA), tablet computers, lap top computers, or personal computers.

Abstract: Methods and systems for isolating transmit and receive circuitry at an ultrasound transducer element are provided. Separate electrodes or electrodes on opposite sides of a transducer element are connected to the separate transmit and receive paths or channels. Instead of high voltage transmit and receive switching, the transducer element isolates the transmit channel from the receive channel. The transmit channel includes circuitry for limiting the voltage at one electrode during receive processing, such as a switch operable to connect the electrode to ground. The receive channel includes circuitry for limiting the voltage at an electrode during transmit processing, such as a diode clamp preventing voltage swings greater than diode voltage at the electrode. Limiting the voltage provides virtual grounding or a direct current for either of the transmit or receive operation.

Abstract: Methods and systems for receiving different types of signal formats from different ultrasound transducers are provided. A base unit of an ultrasound system includes a connector and receiver circuit for connecting with one of multiple different types of transducers. For example, a conventional transducer providing analog information associated with a single element on one receive channel is connected with the connector and receiver circuit. Alternatively, a transducer outputting time division multiplex or other multiplex information representing multiple transducer elements is connected with the connector and receiver circuit. The receiver circuit processes the received information differently depending on the data format. For example, the preamplifier impedance or gain is different for single element signals versus time division multiplex signals. As another example, a low pass filter bandwidth is larger for time division multiplex signals than for signals representing a single element.

Abstract: A transmit pulser includes an H-bridge of four transistors. First and second transistors of the H-bridge connect with a first electrode of a transducer element, and third and fourth transistors of the H-bridge connect with a second electrode of the transducer element. A differential receive amplifier connects with the first and third transistors. First and second diode clamps connect with the first and third transistors, respectively, and the inputs to the differential receive amplifier. The second and fourth transistors connect to a same power or voltage source, imposing a same voltage in either a forward or a reverse direction. By using matched transistor pairs (e.g. first and third matched pair and second and fourth matched pair), symmetrical transmit waveforms are generated. Symmetrical transmit waveforms allow for using phase inversion or phase differences between transmit waveforms for imaging, such as for harmonic imaging of tissue.

Abstract: Transmitters for generating multilevel transmit waveforms for medical diagnostic ultrasound are provided. Voltages from a plurality of sources are superposed or summed. Switches control the amplitude and polarity of the summed voltages so that a transmit waveform having four or more, such as nine, voltage levels is provided. A simple switching pulser without a power amplifier combines voltages applied to two or more flux paths in a third flux path. Superposition of magnetic flux in the third flux path provides for an output voltage responsive to the sum and difference of two different voltages. Alternatively or additionally, the secondary windings of multiple transformers are connected in series with a transducer element. By providing different input voltages to each of the transformers, the multilevel transmit waveform is generated.

Abstract: A system for controlling the point spread function of an ultrasound signal transmitted into a patient. In accordance with one embodiment of the invention, only a selected number of the transducer elements transmit a transmit pulse. The elements which do not transmit the pulse are selected in accordance with an apodization probability density function. In accordance with another aspect of the present invention, each transducer element transmits a variable portion of a transmit pulse in order to control the acoustic power of the signal transmitted from each element.

Abstract: A segmented ultrasound system is provided. Ultrasound data, such as image data in a video format, is wirelessly transmitted to a multi-use display device from a handheld ultrasound device. Any of various multi-use display devices may be used, such as personal digital assistants (PDA), tablet computers, lap top computers, or personal computers.

Abstract: A locomotive air dyer air discharge conduit is configured to disperse a portion of the discharge air radially through one or more air dispersion openings in the side of the discharge conduit, thereby reducing the output velocity of the discharge air.

Abstract: A locomotive air dyer air discharge conduit is configured to disperse a portion of the discharge air radially through one or more air dispersion openings in the side of the discharge conduit, thereby reducing the output velocity of the discharge air.

Abstract: An ultrasound front end circuit (1000) according to the present invention includes a single transformer core which performs all of the pulse and transmit/receive switching functions. A transmit pulser (1102) is formed by a pair of transistor switches in combination with a transformer having first windings (N1, N2) driven by a DC source. A secondary winding (N3) provides a voltage step up for transmitted wave forms and a pair of anti-parallel shunt diodes (1014) on the receiver terminal direct the transmitted 0 waveform to the ultrasound transducer (1024). A floating third winding (N4) shunted by a current biased diode bridge (1002) provides an effective open circuit across the secondary winding while transmitting high amplitude signals. The third winding (N4) and diode bridge (1002) act to short circuit the secondary winding (N3) while receiving small amplitude signals, thus providing a direct connection between the transducer (1024) and receiver (1020).

Abstract: An amplifier (32) is provided which allows for reduced system power dissipation. The amplifier (32) can dynamically draw power from different supply voltages in response to an input voltage signal. The amplifier (32) includes a plurality of complementary transistor pairs (40-46), where each transistor pair is coupled to a respective power supply. Each transistor pair provides output current when the input voltage signal is within a respective predetermined voltage range. This arrangement permits the amplifier (30) to interpolate between the supply voltages to generate a continuous amp output. System power is conserved by selecting the power supply which can most efficiently supply the required current within the voltage range.

Abstract: A cutter drive for a computer driven printer/plotter employs a cutter carriage which is separate from the printer carriage and which is attachable to and detachable from the printer carriage to be moved thereby without a separate cutter drive. Camming surfaces on a pickup arm and a pickup hook permit the cutter carriage to be mechanically engaged and disengaged from the printer carriage without any motors or magnets.

Abstract: A rigid low cost chassis structure for a wide print media thermal ink jet plotter wherein the carriage slider rods are straightened and held in precise position relative to the platen roller during assembly of the chassis parts and operation of the plotter by using an extruded rigid support beam and a pair of rigid endplates and connecting structure which positions and holds the slider rods.

Abstract: A workbench capable of clamping workpieces of various thicknesses. The workbench includes a laterally disposed work table mounted on a support structure. A clamping member is provided which includes a clamp positioned above the work table and configured to clamp a workpiece between the clamp and the work table. The workbench further includes a foot treadle pivotally mounted on the support structure. A linkage interconnects the foot treadle wit the clamping member such that rotation of the foot treadle in a first direction moves the clamp into clamping relation with the work table, and rotation of the foot treadle in a second direction moves the clamp away from the work table.

Abstract: Structures of magnetic heads having superconducting shields are disclosed for spatially directing magnetic recording/playback fields. One embodiment is a thin film magnetic head with a layer of superconductor material associated with its throat. Further embodiments provide intertrack shielding and concentration of recording/playback fields into relatively small pole tip regions.

Abstract: A workbench capable of clamping workpieces of various thicknesses. The workbench includes a laterally disposed work table mounted on a support structure. A clamping member is provided which includes a clamp positioned above the work table and configured to clamp a workpiece between the clamp and the work table. The workbench further includes a foot treadle pivotally mounted on the support structure. A linkage interconnects the foot treadle with the clamping member such that rotation of the foot treadle in a first direction moves the clamp into clamping relation with the work table, and rotation of the foot treadle in a second direction moves the clamp away from the work table.

Abstract: A plotter instrument for marking on a recording medium utilizes a rotatable pen carousel carrying a plurality of marking pen elements. A carriage drives the pen carousel into engagement with a cam track to produce rotation of the pen carousel and result in a change of the marking pen element in position for marking on the recording medium. The plotter instrument further includes drive rollers on a first driven shaft and pinch rollers on a second shaft, which shafts extend between opposing end plates. The drive rollers and pinch rollers are engagable with the recording medium for providing displacement thereof. Relative positioning of the drive and pinch rollers is provided by a pinch roller shaft cap eccentrically placed on each end of the second shaft. Each shaft cap is of a multi-sided, regular polygon configuration and insertable in a respective end plate opening. The orientation at which the cap is inserted determines the relative spacing between the drive rollers and the pinch rollers.