Circuitry for ultrasound devices is described. A multilevel pulser is described, which can provide bipolar pulses of multiple levels. The multilevel pulser includes a pulsing circuit and pulser and feedback circuit. Symmetric switches are also described. The symmetric switches can be positioned as inputs to ultrasound receiving circuitry to block signals from the receiving circuitry.

Some embodiments relate to a system and method of estimating the viscoelasticity of a material. The system and method includes receiving a plurality of time-amplitude curves measured at a plurality of space points. The time-amplitude curves reflect time evolutions of a propagating mechanical wave. The system and method also include estimating the viscoelasticity of a material between any set of space points using the time-amplitude curves measured at those space points.

A system for delivering ultrasound energy to an internal anatomical target includes an ultrasound transducer having multiple transducer elements collectively operable as a phased array; multiple driver circuits, each being connected to at least one of the transducer elements; multiple phase circuits; a switch matrix selectably coupling the driver circuits to the phase circuits; and a controller configured for (i) receiving as input a target average intensity level and/or an energy level energy to be applied to the target and/or a temperature level in target, (ii) identifying multiple sets of the transducer elements, each of the sets corresponding to multiple transducer elements for shaping and/or focusing, as a phased array, ultrasound energy at the target across tissue intervening between the target and the ultrasound transducer, and (iii) sequentially operating the transducer-element sets to apply and maintain the target average energy level at the target. In various embodiments, the controller operates each of the transducer element sets in accordance with a pulse-width modulation pattern having a duty cycle selected to achieve the target average intensity level, energy level, and/or temperature level at the target in accordance with a time constant of the target tissue.

The present disclosure describes ultrasound systems configured to perform microbubble-based contrast imaging with enhanced sensitivity. The systems can enhance echo signals derived from microbubbles while suppressing echo signals derived from tissue by detecting phase shifts exhibited by microbubbles in resonance. To detect the phase shifts, and thereby distinguish between microbubble-based signals and tissue-based signals, the systems can transmit a series of ultrasound pulses into a target region in accordance with a predefined sequence. The sequence can include an initiation pulse configured to stimulate microbubbles into nonlinear oscillation, a detection pulse configured to detect the nonlinear oscillation, and a summation pulse formed by transmitting an initiation pulse and detection pulse with a small time delay therebetween. A signal processor included in the system can determine phase shifts exhibited by the signals generated in response to the series of pulses and mask non-microbubble-based signals based on the magnitude of the detected phase shifts.

High volume-rate three-dimensional (“3D”) ultrasound imaging using fast acoustic steering via tilting electromechanical reflectors is described. Ultrasound beams are directed towards one or more tilting reflectors, which are scanned through a range of tilt angles in order to image a 3D field-of-view with a high volume rate.

An ultrasound imaging device includes: a processor including hardware, the processor being configured to control ah ultrasound transducer to transmit a push pulse in response to input of an operation; set, based on an amount of movement of the ultrasound transducer in a predetermined time period according to the input of the operation, transmission parameter for transmitting a track pulse; and control the ultrasound transducer to transmit the track pulse toward a shear wave detection position set in an ultrasound image.

A shear wave elastography method for imaging an observation field in an anisotropic medium, including an initial ultrasonic acquisition step during which initial physical parameters are acquired in at least one region of interest; a spatial characterization step during which a set of spatial characteristics of the anisotropic medium is determined on the basis of the initial physical parameter; an excitation substep during which an shear wave is generated inside the anisotropic medium on the basis of the set of spatial characteristics; and an observation substep during which the propagation of the shear wave is observed simultaneously at a multitude of points in the observation field.

The present disclosure describes systems and methods configured to determine shear wave velocity and tissue stiffness levels of thin tissue of finite size, also referred to as bounded tissue, via shear wave elastography. Systems can include an ultrasound transducer configured to acquire echoes responsive to pulses transmitted toward a tissue. Systems can also transmit a push pulse into the tissue for generating shear waves, and tracking pulses intersecting the shear waves. The system can also apply a directional filter to received echo data and generate directionally filtered shear wave data based on a dimension and angular orientation of the bounded target relative to the ultrasound transducer. The system can estimate velocities of the shear waves at different shear wave frequencies based on the filtered shear wave data and angular orientation relative to the transducer, and determine a tissue stiffness value independent of the shape or form of the tissue.

A system and method includes transmission of an ultrasound push pulse toward material along a first axis, the ultrasound push pulse associated with a first frequency, a first F number, and a first focal depth, determination of displacement of the material along the axis in response to the push pulse, transmission of a second ultrasound pulse toward the material along the first axis, the second ultrasound pulse associated with a second frequency, a second F number, and a second focal depth substantially similar to the first frequency, the first F number, and the first focal depth, respectively, reception of echo signals from the material in response to the second ultrasound pulse, beamforming of the echo signals based on the first F number and a fixed focus at the first focal depth, determination of a magnitude of the beamformed echo signals along the axis, determination of relative elasticity of the material along the axis based on the determined displacement of the material along the axis and the magnitude of the beamformed echo signals along the axis, and generation of an image based on the determined relative elasticity of the material along the axis.

Systems and methods for performing shear wave elastography using push and/or detection ultrasound beams that are generated by subsets of the available number of transducer elements in an ultrasound transducer. These techniques provide several advantages over currently available approaches to shear wave elastography, including the ability to use a standard, low frame rate ultrasound imaging system and the ability to measure shear wave speed throughout the entire field-of-view rather than only those regions where the push beams are not generated.