Abstract: A current impulse (CI) method is provided for converting digital data signals to analog values. First, digital data bits are converted into current impulses. Then, the current impulses are converted into analog currents representing the digital data bits. More typically, the method accepts a k-bit digital word, and converts the k-bit digital word into (k) corresponding current impulses. In one aspect, the method accepts (n) consecutive k-bit digital words. Then, for each bit position in the k-bit digital word, (n) consecutive bits are sampled using (n) consecutive phases of an n-phase clock, creating (n) interleaved current impulses. The (n) interleaved current impulses are converted into an analog current representing the (n) consecutive k-bit digital words. Alternatively, (n) consecutive bits are sampled using (n) consecutive phases of an n-phase clock for each bit position in the k-bit digital word, creating (n) summed current impulses. A CI digital-to-analog converter is also provided.

Abstract: An ultrasound imaging system includes a transducer array, with an array of transducer elements that transmits an ultrasound signal and receives a set of echoes generated in response to the ultrasound signal traversing a flowing structure. The ultrasound imaging system further includes a beamformer that beamforms the set of echoes, generating a beamformed signal. The ultrasound imaging system further includes a pre-processor that performs basebanding, averaging and decimation of the beamformed signal and determines an autocorrelation of the basebanded, averaged and decimated beamformed signal. The ultrasound imaging system further includes a velocity processor that generates an axial velocity component signal and a lateral velocity component signal based on the autocorrelation. The axial and lateral velocity components indicate a direction and a speed of the flowing structure in the field of view.

Abstract: A method includes calibrating color bleed factors of optical detector channels of a sample processing apparatus through processing a color bleed calibration substance which includes a plurality of different size fragments replicated from different groups of DNA loci, wherein fragments in a same group are labeled with a same fluorescent dye, and fragments in different groups are labeled with different fluorescent dyes having different emission spectra, wherein the different size fragments are processed during different acquisition times.

Abstract: Among other things, a communication system and technique for transferring information between a stationary unit and a rotating unit of a computed tomography (CT) system is provided. A transmitter is configured to map digital data to an analog signal by selecting, from at least three signal configurations, a signal configuration associated with the digital data, and to generate an analog signal according to the selected signal configuration. A receiver of the communication system is configured to decode an analog signal by comparing characteristics of a signal sample to at least three possible signal configurations, and to identify a digital code word that corresponds to a signal configuration (of the at least three possible signal configurations) that matches characteristics of the signal sample. In this way, in a CT application, more than 1-bit of data may be communicated per analog signal, allowing more data to be communicated faster.

Abstract: Among other things, one or more data-links for transferring information between a stationary unit and a movable (e.g., rotating) unit, or between two movable units without contact between the units is provided. A transmitting antenna of a data-link comprises at least two capacitive conducting portions, a first portion configured to conduct signals having a first frequency range (e.g., a higher frequency range) and a second portion configured to conduct signals having a second frequency range (e.g., a lower frequency range). The second portion is comprised of a plurality of members (e.g., conductive plates) arranged to create a substantially continuous electrically conductive structure (e.g., although respective members may not be in physical contact with adjacent members). In this way, a loss of capacitance in a transition between two adjacent members is reduced to provide for transferring information at lower frequencies where a higher capacitance is desirable, for example.

Abstract: Radiation flux can be adjusted “on the fly” as an object (204) is being scanned in a security examination apparatus. Adjustments are made to the radiation flux based upon radiation incident on a first radiation detector (226) in an upstream portion (233) of an examination region. The object under examination is thus exposed to different radiation flux in coordination with a downstream motion (235) of the object relative to a second radiation detector (228). The radiation flux is adjusted so that a sufficient number of x-rays (that traverse the object) are incident on the second radiation detector. Images of the object can then be generated based upon data from the second radiation detector, where these images are thus of a desired/higher quality.

Abstract: One or more techniques and/or systems described herein provide for a detector array having an effective size that is larger than its actual size of its elements, thus reducing costs by reducing materials required. In one embodiment, one or more channels of the detector array are removed (e.g., and filled with a radiation absorbing material) to create what may be referred to as a sparse array. In another embodiment, one or more channels of a detector array comprise a detection portion and a dead space (e.g., filled with a radiation absorbing material). In yet another embodiment, one or more channels of a detector array comprise light focusing mechanisms configured to focus light from a scintillator portion of an indirect conversion detector array to a photodetector portion of the detector array, where a detection surface area of the photodetector is less than a detection surface area of the scintillator.

Abstract: Among other things, one or more techniques and/or systems are described for reducing a voltage ripple in an electric signal. In this way, in radiographic imaging modalities, for example, undesired fluctuations in an output of a radiation source (e.g., undesirable fluctuations in an energy level of emitted photons) may be reduced. To reduce the voltage ripple, a (ripple reducing) electric signal is generated that comprises properties substantially similar to the voltage ripple, but opposite in phase. The (ripple reducing) electric signal is then combined with the original electric signal to generate a combined electric signal with a voltage ripple that is reduced relative to the voltage ripple of the electric signal as initially generated.

Abstract: An optical system includes a sample carrier receiving region configured to receive a carrier carrying a sample for processing, a source that emits an excitation signal having a wavelength within a first predetermined wavelength range, and a first set of optical components that direct the excitation signal along an excitation path to the sample carrier receiving region, wherein radiation having a wavelength within a second predetermined wavelength range is emitted from the sample carrier receiving region in response to receiving the excitation signal. The system further includes a detector configured to detect the emitted radiation and generates a signal indicative of a power of the detected radiation and a second set of optical components that directs the emitted radiation along a collection path to the detector and a power meter that measures a power of the radiation emitted from the sample carrier receiving region and generates a signal indicative thereof.

Abstract: A Traveling Pulse Wave Quantization method is provided for converting a time sensitive signal to a digital value. A first stop signal is delayed by a first time delay, a first plurality of times, to create a delayed first stop signal. A clock signal is delayed by a second time delay, a first plurality of times, to create a delayed clock signal first period. Each second time delay is associated with a corresponding first time delay, and the second time delay is greater than the first time delay. When the delayed first stop signal occurs before the delayed clock signal first period, a count of the delays is stopped and converted into a digital or thermometer value. An accurate resampled value is provided regardless of the duration in delay between the first stop signal and a second stop signal that is accepted after the first stop signal.

Abstract: A method and system are provided for generating high resolution CT images. The NSR# method improves on the AMPR method, by increasing the in-plane image resolution of CT scanners, in the helical scanning mode. The provided method uses the quarter detector offset and interleaving of complementary data to achieve in plane image resolution that is similar to the high resolution axial scanning mode utilizing quarter detector offset and interleaving. The method includes several ways of choosing the data to be interleaved, like NSR# with two planes, NSR# with 3 planes, NSR# with multiple planes. The interleaved data are used to create high resolution tilted slices. The NSR# method optimizes the untilting filter to create a mix of high and low resolution tilted slices to achieve the desired in-plane image resolution-image artifact balance required for the imaging task. In one embodiment in the untilting process one may use only high resolution tilted slices, for maximum resolution benefit.

Abstract: A method is provided for calibrating the mean frequency of a voltage controlled oscillator (VCO) based analog-to-digital converter (ADC). The method accepts a differential analog input signal comprising a positive signal and a negative signal. The positive signal is converted into a first frequency and the negative signal is converted into a second frequency. The first frequency is converted into a first digital value and the second frequency is converted into a second digital value. The first digital value is added to the second digital value to find a common mode value, and the common mode value is compared to a predetermined common mode value to find a first error. The first error is converted to a first bias modification of the differential analog input signal, and in response to the differential analog input first bias modification, the first error is minimized.

Abstract: Among other things, a rotatable drum for a radiology imaging modality is provided herein. The rotatable drum comprises a bore, defined by an inner circumference of a sidewall of the rotatable drum. In one embodiment, the sidewall comprises one or more apertures through which radiation may pass. By way of example, a radiation source and a detector array may be mounted outside of the bore (e.g., on an outside surface of the sidewall) and apertures in the sidewall may permit radiation to pass from the radiation source to the detector array without being attenuated by the sidewall of the drum. In another embodiment, the detector array may be comprised of a plurality of detector modules that may be individually mounted/dismounted from the rotatable drum, and in one example, may provide structural support to the rotatable drum.

Abstract: Among other things, one or more systems and/or techniques are described for dynamically adjusting, in a fan-angle direction, attenuation of radiation during an examination of an object such that portions of the object that are not represented in resulting (tilted/targeted) images of the object are exposed to less radiation than portions of the object that are represented in resulting (tilted/targeted) images of the object. As a rotating gantry is rotated, blades of a pre-object collimator are dynamically repositioned to selectively attenuate emitted radiation. A collimator adjustment component may be configured to determine how to reposition the blades based at least in part upon at least one of a desired tilt of the resulting (tilted) image(s), a translational position of the object, and a gantry rotation angle, for example.

Abstract: One or more systems and/or techniques are provided to identify objects comprised in a compound object without segmenting three-dimensional image data of the potential compound object. Two-dimensional projections of a potential compound object (e.g., Eigen projections) are examined to identify the presence of known objects. The projections are compared to signatures, such as morphological characteristics, of one or more known objects. If it is determined based upon the comparison that there is a high likelihood that the compound object comprises a known object, a portion of the projection is masked, and it is compared again to the signature to determine if this likelihood has increased. If it has, a sub-object of the compound object may be classified based upon characteristics of the known object (e.g., the compound object may be classified as a potential threat item if the known object is a threat item).

Abstract: A system and method are provided for measuring current sources, such as might be useful in the calibration of a digital-to-analog converter (DAC). The method provides a first plurality of current sources. Each current source is engageable to supply a current representing a corresponding nominal value. The method selectively enables current source combinations of current. In response to measuring the current source combinations, current difference values are found, and the current source nominal values are adjusted using the current difference values. In one aspect, a reference current source is provided having a reference first value, and the current source nominal values are adjusted with respect to the reference first value. The current sources may have corresponding nominal digital values adjusted using measured digital difference values.

Abstract: A system and method for using pre-procedural images for registration for image-guided therapy (IGT), also referred to as image-guided intervention (IGI), in percutaneous surgical application. Pseudo-features and patient abdomen and organ surfaces are used for registration and to establish the relationship needed for guidance. Three-dimensional visualizations of the vasculature, tumor(s), and organs may be generated for enhanced guidance information. The invention facilitates extensive pre-procedural planning, thereby significantly reducing procedural times. It also minimizes the patient exposure to radiation.

Abstract: A system and method are provided of performing background corrections for an interleaving analog-to-digital converter (ADC). An analog input signal s1(t) is accepted having a first frequency f1 and a bandwidth (BW). A clock at frequency fs creates n sample clocks with evenly spaced phases, each having a sample clock frequency of fs/2. A first tone signal s2(t) is generated at second frequency f2, outside BW. The analog input signal and the first tone signal are combined, creating a combination signal, which is sampled using the sample clocks, creating n digital sample signals per clock period 1/fs. The n digital sample signals are interleaved, creating an interleaved signal. Corrections are applied that minimize errors in the interleaved signal, to obtain a corrected digital output. Errors are determined at an alias frequency f3, associated with the second frequency f2, to obtain correction information for a rotating pair of digital sample signals.

Abstract: A charge canceling multiplying digital-to-analog converter (MDAC) is provided with a reference block having inputs to accept reference voltages each sample clock cycle. The MDAC includes a sampling block having inputs to accept differential analog input voltage signals each sample clock cycle. A differential amplifier has a negative input and positive input connected to the reference block and sampling block to receive differential amplifier input signals, and a positive output and a negative output to supply differential output voltage signals each amplify clock cycle. The sampling section includes a first pair of feedback capacitors connected between the differential amplifier negative input and positive output, and a second pair of feedback capacitors connected between the differential amplifier positive input and negative output each amplify clock cycle. A capacitor from the first pair of parallel feedback capacitors is swapped with a capacitor from the second pair prior to each sample clock cycle.

Abstract: Z-effective (e.g., atomic number) values are generated for one or more sets of voxels in a CT density image using sparse (measured) multi-energy projection data. Voxels in the CT density image are assigned a starting z-effective value, causing a CT z-effective image to be generated from the CT density image. The accuracy of the assigned z-effective values is tested by forward projecting the CT z-effective image to generate synthetic multi-energy projection data and comparing the synthetic multi-energy projection data to the sparse multi-energy projection data. When the measure of similarity between the synthetic data and the sparse data is low, the z-effective value assigned to one or more voxels is modified until the measure of similarity is above a specified threshold (e.g., with an associated confidence score), at which point the z-effective values substantially reflect the z-effective values that would be obtained using a (more expensive) dual-energy CT imaging modality.