Systems and methods for transmitting non-diffracting acoustic beams are presented herein. In one example, a method for transmitting a non-diffracting acoustic beam with an ultrasound transducer that includes a plurality of transducer elements includes determining a transmit delay function and a transmit apodization function for the ultrasound transducer based on a target axial pressure profile for the acoustic beam for a given configuration of the ultrasound transducer and controlling the ultrasound transducer to transmit the acoustic beam by sending electrical signals to the plurality of transducer elements based on the transmit delay function and the transmit apodization function.

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.

The present invention proposes an ultrasound imaging system and method for measuring a property of a region of interest in a subject by using shear wave, wherein an ultrasound probe is configured to sequentially transmit, to each of a plurality of focal spots (320, 322, 324) in the region of interest, a push pulse (310, 312, 314) for generating a shear wave (330, 332, 334), each of the plurality of focal spots having a mutually different depth value (z1, z2, z3), and to receive ultrasound echo signals adjacent (350, 352, 354) to each of the plurality of focal spots; a shear wave detector is configured to derive, for each of the plurality of focal spots, a first parameter indicating a property of the generated shear wave, based on the received ultrasound echo signals; and a property estimator is configured to estimate a second parameter indicating the property of the region of interest 342 as a function of the derived first parameters.

A defibrillator produces a biphasic defibrillation pulse waveform with adjustable tilt for the second phase. The tilt of the second phase of the biphasic waveform can be controllably adjusted by selectively switching a current path which bypasses the patient during delivery of the second phase of the pulse. The inventive biphasic waveform can be delivered by a defibrillator with a single capacitance.

For clutter reduction in ultrasound elasticity imaging, the contribution of clutter to different frequency components (e.g., the transmit fundamental and the propagation generated second harmonic) is different. As a result, a difference in displacements determined at the different frequency bands is used to reduce clutter contribution to displacements used for elasticity imaging.

An ultrasound imaging system integrated on a chip for autonomous scanning includes an on-chip input memory configured to store scan sequence instructions and parameters, an on-chip processor configured to read the scan sequence instructions and parameters in the input memory, and an on-chip beamformer configured to be programmed and timed by the processor according to the scan sequence instructions and parameters. In some examples, the scan sequence instructions and parameters are stored in a nonvolatile input memory programmed at the factory. In other examples, they are received from an external user device. The scan parameters are optimized or minimized to accommodate the limited input memory capacity. In some examples, the scan sequence instructions and parameters include programmable nested loops, and each of the programmable nested loops corresponds to a transmit and/or receive event in a scan sequence.

An ultrasound diagnosis apparatus includes: a two-dimensional (2D) array ultrasound probe configured to emit focused beams onto a plurality of focusing points and detect echo signals; and a processor configured to determine the plurality of focusing points on a cross-section of interest and acquire shear wave elasticity data with respect to the cross-section of interest based on the detected echo signals.

An ultrasonic transducer array probe (10) for shear wave imaging has a number of transducer elements which exceeds the number of transmit channels of a shear wave diagnostic imaging system. The probe includes a switch matrix or multiplexer (60) which selectively couples channels of the transmit beamformer (18) to the transducer elements of multiple shear wave apertures of the array. When the transmit beamformer is actuated, a plurality of push pulses are transmitted simultaneously to initiate shear waves in a subject.

Shear waves are generated and measured in viscoelastic phantoms by a single push beam. Using numerical simulations or an analytical function to describe the diffraction of the shear wave, the resulting shear wave motion induced by the applied push beam is calculated with different shear elasticity values and then convolved with a separate expression that describes the effects of viscosity value for the medium. The optimization algorithm chooses the tissue parameters which provide the smallest difference between the measured shear waveform and the simulated shear waveform. A shear viscosity image is generated by applying such optimization procedure at all of the observation points.

An ultrasound system drives the elements of an ultrasound probe with asymmetric transmit signals which reinforce poling of the probe transducer. The use of asymmetric transmit signals enables a transducer element to withstand a significantly higher RF transmit voltage without degradation, which in turn enables higher acoustic output and improved reliability. This is particularly beneficial with single crystal transducer material when used to generate high energy pressure waves of long duration such as shear wave push pulses.