Abstract: A system for generating a magnetic field for excitation of a leadless marker assembly. The system of at least one embodiment includes a source generator that generates a plurality of alternating electrical signals each having an independently adjustable phase. A plurality of excitation coils are configured to simultaneously receive a respective one of the alternating electrical signals at a selected phase to generate a magnetic field. The phase of the alternating electrical signal for each excitation coil is independently adjustable relative to the phase of the alternating electrical signal for the other excitation coils so as to adjust the magnetic field from the respective coil. The magnetic fields from the excitation coils combine to form a spatially adjustable excitation field for excitation of the remote leadless marker assembly.

Abstract: A system for generating a magnetic field for excitation of a leadless marker assembly. The system of at least one embodiment includes a source generator that generates a plurality of alternating electrical signals each having an independently adjustable phase. A plurality of excitation coils are configured to simultaneously receive a respective one of the alternating electrical signals at a selected phase to generate a magnetic field. The phase of the alternating electrical signal for each excitation coil is independently adjustable relative to the phase of the alternating electrical signal for the other excitation coils so as to adjust the magnetic field from the respective coil. The magnetic fields from the excitation coils combine to form a spatially adjustable excitation field for excitation of the remote leadless marker assembly.

Abstract: A system for generating a magnetic field for excitation of a leadless marker assembly. The system of at least one embodiment includes a source generator that generates a plurality of alternating electrical signals each having an independently adjustable phase. A plurality of excitation coils are configured to simultaneously receive a respective one of the alternating electrical signals at a selected phase to generate a magnetic field. The phase of the alternating electrical signal for each excitation coil is independently adjustable relative to the phase of the alternating electrical signal for the other excitation coils so as to adjust the magnetic field from the respective coil. The magnetic fields from the excitation coils combine to form a spatially adjustable excitation field for excitation of the remote leadless marker assembly.

Abstract: A system for generating a magnetic field for excitation of a leadless marker assembly. The system of at least one embodiment includes a source generator that generates a plurality of alternating electrical signals each having an independently adjustable phase. A plurality of excitation coils are configured to simultaneously receive a respective one of the alternating electrical signals at a selected phase to generate a magnetic field. The phase of the alternating electrical signal for each excitation coil is independently adjustable relative to the phase of the alternating electrical signal for the other excitation coils so as to adjust the magnetic field from the respective coil. The magnetic fields from the excitation coils combine to form a spatially adjustable excitation field for excitation of the remote leadless marker assembly.

Abstract: A processor for pulsed Doppler velocity measurement utilizes a two dimensional discrete Fourier transform to map wideband signals into a frequency space where constant velocity Doppler spectral components are represented as radial lines. A radial projection then extracts target velocity information.

Abstract: A method for displaying the values of two parameter at a plurality of points in an image. The intensity of each pixel in the display is modulated in accordance with the value of the first parameter at corresponding points in the image. The hue of each pixel is modulated to a first color whenever the value of the second parameter at the corresponding point in the image is greater than a reference value and to a second color whenever the value of the second parameter is less than the reference value. The saturation at each pixel is modulated as a function of the absolute value of the deviation of the second parameter from the reference value at the corresponding point in the image.

Abstract: A method and apparatus for displaying an image which has a wide dynamic range. Low spatial frequency components of the image are extracted from the image signal and are presented as a color overlay which tints an intensity modulated display of local high spatial frequency image components. In a preferred embodiment, the hue of the color overlay is modulated to indicate whether the local background component is greater than or less than an equilibrium value while the saturation is modulated to indicate the absolute value of the deviation.

Abstract: A method for displaying the values of two parameter at a plurality of points in an image. The intensity of each pixel in the display is modulated in accordance with the value of the first parameter at corresponding points in the image. The hue of each pixel is modulated to a first color whenever the value of the second parameter at the corresponding point in the image is greater than a reference value and to a second color whenever the value of the second parameter is less than the reference value. The saturation at each pixel is modulated as a function of the absolute value of the deviation of the second parameter from the reference value at the corresponding point in the image. In a preferred embodiment, the first parameter corresponds to the amplitude of echoes in a diagnostic ultrasound image and the second parameter corresponds to the instantaneous frequency deviation of the echoes.

Abstract: In an ultrasonic diagnostic system the invention utilizes the concept that for pulse echo medical ultrasound signals the mean instantaneous frequency estimates are improved by imposing the condition that a local frequency estimate is ignored unless a condition of the amplitude exceeding some threshold is met. It provides for the use of conditional frequency or zero crossing rate measurement as applied to ultrasound attenuation measurement and also to local frequency shift measurement due to frequency dependent scattering. The system simultaneously detects the amplitude of the signal, delays the RF waveform to satisfy causality and then conditionally accepts the frequency demodulated image only when a preselected amplitude is exceeded. The system requires that the amplitude of the instantaneous RF signal exceed a set threshold in order for the half cycle of the signal to be processed.