Abstract: An ultrasonic diagnostic imaging system produces an image of shear wave velocities by transmitting push pulses to generate shear waves. A plurality of tracking lines are transmitted and echoes received by a focusing beamformer adjacent to the location of the push pulses. The tracking lines are sampled in a time-interleaved manner. The echo data acquired along each tracking line is processed to determine the time of peak tissue displacement caused by the shear waves at points along the tracking line, and the times of peaks at adjacent tracking lines compared to compute a local shear wave velocity. The resultant map of shear wave velocity values is color-coded and displayed over an anatomical image of the region of interest.

Abstract: Shear Wave Dispersion Vibrometry (SDUV) is performed such that, after a single instance of their push pulse (218), a plurality of tracking pulses (222) are issued to sample, more than once, each of a plurality of locations (120, 148) on an associated monochromatic shear wave (116) in sampling that at least one of scans the plural locations in separate passes and, with a pulse of the plural tracking pulses, samples multiple ones of the plural locations concurrently. In a supplementary aspect, phase difference, for a given moment, is determined by taking into account intersample delay (156), if the determination relies on samples that are taken at different times.

Abstract: An ultrasonic diagnostic imaging system produces an image of shear wave velocities by transmitting push pulses to generate shear waves. A plurality of tracking lines are transmitted and echoes received by a focusing beamformer adjacent to the location of the push pulses. The tracking lines are sampled in a time-interleaved manner. The echo data acquired along each tracking line is processed to determine the time of peak tissue displacement caused by the shear waves at points along the tracking line, and the times of peaks at adjacent tracking lines compared to compute a local shear wave velocity. The resultant map of shear wave velocity values is color-coded and displayed over an anatomical image of the region of interest.

Abstract: Shear Wave Dispersion Vibrometry (SDUV) is performed such that, after a single instance of their push pulse (218), a plurality of tracking pulses (222) are issued to sample, more than once, each of a plurality of locations (120, 148) on an associated monochromatic shear wave (116) in sampling that at least one of scans the plural locations in separate passes and, with a pulse of the plural tracking pulses, samples multiple ones of the plural locations concurrently. In a supplementary aspect, phase difference, for a given moment, is determined by taking into account intersample delay (156), if the determination relies on samples that are taken at different times.

Abstract: Shear Wave Dispersion Vibrometry (SDUV) is performed such that, after a single instance of their push pulse (218), a plurality of tracking pulses (222) are issued to sample, more than once, each of a plurality of locations (120, 148) on an associated monochromatic shear wave (116) in sampling that at least one of scans the plural locations in separate passes and, with a pulse of the plural tracking pulses, samples multiple ones of the plural locations concurrently. In a supplementary aspect, phase difference, for a given moment, is determined by taking into account intersample delay (156), if the determination relies on samples that are taken at different times.

Abstract: Shear wave dispersion ultrasound vibrometry (SDUV) is implemented in some embodiments to form, from a single tracking pulse, in-parallel-directed receive lines (411-426) for making measurements of a monochromatic shear wave. In some embodiments, sampling is performed, over spatial locations by means of passes over the locations, in an interlaced pattern (600) for making measurements of the wave. In some embodiments, measurements are made of the wave and to the measurements are applied a bank of filters (S724) that are tuned to respective candidate wave speeds, all without the need to determine a difference between wave phases at different spatial locations (451-454).

Abstract: A catheter apparatus includes an elongated body having proximal and distal ends, and an acoustic transducer disposed proximate the distal end of the elongated body. A variably-refracting acoustic lens is provided to dynamically adjust a direction associated with an acoustic wave coupled to the acoustic transducer in response to one or more control signals provided thereto.

Abstract: An ultrasonic assembly suited for attachment to a catheter, e.g. for medical treatment. The ultrasonic assembly includes an adjustable ultrasonic focus mechanism arranged in connection with the ultrasonic transducer to adjust focus of ultrasonic waves generated by the transducer. The ultrasonic focus mechanism includes a fluid focus lens with at least two fluids separated by an interface such that ultrasonic waves are substantially reflected at the interface. At least two electrodes are arranged in connection with the fluid focus lens so as to allow adjustment of the interface shape, e.g. a curvature of the interface, when a voltage is applied to the electrodes. In preferred embodiments the electrodes are arranged so as to allow adjustment of the fluid focus lens in an elevation direction as well as in a radial direction. In simple embodiments with rotational symmetric geometry with the transducer positioned in the center of the fluid focus lens, ultrasonic waves can be focused in an annular ring. This is e.

Abstract: An ultrasonic diagnostic imaging system produces an image of shear wave velocities by transmitting push pulses to generate shear waves. A plurality of tracking lines are transmitted and echoes received by a focusing beamformer adjacent to the location of the push pulses. The tracking lines are sampled in a time-interleaved manner. The echo data acquired along each tracking line is processed to determine the time of peak tissue displacement caused by the shear waves at points along the tracking line, and the times of peaks at adjacent tracking lines compared to compute a local shear wave velocity. The resultant map of shear wave velocity values is color-coded and displayed over an anatomical image of the region of interest.

Abstract: An adjustable fluid type lens system is provided that allows e.g. ultrasound imaging through the lens during adjustment of the lens. The lens includes a container enclosing two immiscible fluids, e.g. water and oil, being in contact with each other at an interface. Incoming waves are then refracted at this interface. The shape of the interface, and thereby the refraction property, is adjustable by adjusting a voltage applied to the lens. The two fluids are selected such that they together exhibit a mechanical damping which is critical or near critical. A control circuit generates the electric voltage for adjusting the refraction from one value to another, the control circuit being arranged to change the electric voltage such that a rate of voltage change is limited to avoid oscillation of the interface, thereby adjusting refraction of incoming waves at the interface in a continuous manner.

Abstract: Shear Wave Dispersion Vibrometry (SDUV) is performed such that, after a single instance of their push pulse (218), a plurality of tracking pulses (222) are issued to sample, more than once, each of a plurality of locations (120, 148) on an associated monochromatic shear wave (116) in sampling that at least one of scans the plural locations in separate passes and, with a pulse of the plural tracking pulses, samples multiple ones of the plural locations concurrently. In a supplementary aspect, phase difference, for a given moment, is determined by taking into account intersample delay (156), if the determination relies on samples that are taken at different times.

Abstract: Shear wave dispersion ultrasound vibrometry (SDUV) is implemented in some embodiments to form, from a single tracking pulse, in-parallel-directed receive lines (411-426) for making measurements of a monochromatic shear wave. In some embodiments, sampling is performed, over spatial locations by means of passes over the locations, in an interlaced pattern (600) for making measurements of the wave. In some embodiments, measurements are made of the wave and to the measurements are applied a bank of filters (S724) that are tuned to respective candidate wave speeds, all without the need to determine a difference between wave phases at different spatial locations (451-454).

Abstract: A catheter apparatus (100, 2000, 3000, 4000, 540) includes an elongated body (110) having proximal (112) and distal (114) ends, an acoustic transducer (130, 2300, 5 3300, 4300, 544), disposed proximate the distal end (114) of the elongated body (110), and a variably-refracting acoustic lens (140, 2200, 3200, 4200, 542) adapted to dynamically adjust a direction associated with an acoustic wave coupled to the acoustic transducer in response to one or more control signals provided thereto.

Abstract: An adjustable fluid type lens system is provided that allows e.g. ultrasound imaging through the lens during adjustment of the lens. The lens includes a container enclosing two immiscible fluids, e.g. water and oil, being in contact with each other at an interface. Incoming waves are then refracted at this interface. The shape of the interface, and thereby the refraction property, is adjustable by adjusting a voltage applied to the lens. The two fluids are selected such that they together exhibit a mechanical damping which is critical or near critical. A control circuit generates the electric voltage for adjusting the refraction from one value to another, the control circuit being arranged to change the electric voltage such that a rate of voltage change is limited to avoid oscillation of the interface, thereby adjusting refraction of incoming waves at the interface in a continuous manner.

Abstract: An ultrasonic assembly suited for attachment to a catheter, e.g. for medical treatment. The ultrasonic assembly includes an adjustable ultrasonic focus mechanism arranged in connection with the ultrasonic transducer to adjust focus of ultrasonic waves generated by the transducer. The ultrasonic focus mechanism includes a fluid focus lens with at least two fluids separated by an interface such that ultrasonic waves are substantially reflected at the interface. At least two electrodes are arranged in connection with the fluid focus lens so as to allow adjustment of the interface shape, e.g. a curvature of the interface, when a voltage is applied to the electrodes. In preferred embodiments the electrodes are arranged so as to allow adjustment of the fluid focus lens in an elevation direction as well as in a radial direction. In simple embodiments with rotational symmetric geometry with the transducer positioned in the centre of the fluid focus lens, ultrasonic waves can be focused in an annular ring. This is e.