Abstract: Described here are systems and methods for ultrasound processes using shear wave attenuation and velocity derived from k-space analysis by analyzing spatial frequency domain data.

Abstract: The present invention provides a system and method for ultrasound processes using wave attenuation derived from k-space analysis by analyzing spatial frequency domain data.

Abstract: A system and method for measuring material properties of a medium includes producing a multi-directional wave field in the medium and detecting, with a detection system capable of detecting wave fields propagating in a medium, the multi-directional wave field in at least two spatial dimensions over at least one time instance. The system and method also include determining a lowest wave speed, calculating at least one of wave speed and material properties of the medium, and generating a report indicating the at least one of wave speed and material properties of the medium.

Abstract: A system and method for measuring material properties of a medium includes producing a multi-directional wave field in the medium and detecting, with a detection system capable of detecting wave fields propagating in a medium, the multi-directional wave field in at least two spatial dimensions over at least one time instance. The system and method also include determining a lowest wave speed, calculating at least one of wave speed and material properties of the medium, and generating a report indicating the at least one of wave speed and material properties of the medium.

Abstract: A model-independent method for producing a viscoelastic tissue property metric using ultrasound is provided. A mechanical stress, such as an acoustic force, is applied to a tissue during a creep period using an ultrasound system to generate a creep response. Tissue displacement resulting from the applied acoustic force is measured during a recovery period following the creep period. From the tissue displacement measurements, a relative complex modulus is extracted, and a loss tangent is calculated based on extracted complex modulus. Using the calculated loss tangent, viscoelastic tissue property metrics may be calculated.

Abstract: A method for generation and analysis of shear waves in a subject with an ultrasound system. Multiple short ultrasound push pulses are applied, as a set and optionally more than once, to one or more push origins at the subject to produce first and second shear waves of large amplitudes and desired spatial distributions, which are separated in space and time and which have opposite polarity such that initial movements of the subject tissue, respectively caused by the first and second shear waves, occur in opposite directions. At least one mechanical property of the subject (including that represented by shear wave group velocity, phase velocity, and attenuation of a shear wave) is determined based at least in part on a distance between wavefronts of the first and second shear waves.

Abstract: The present invention provides a system and method for ultrasound processes using wave attenuation derived from k-space analysis by analyzing spatial frequency domain data.

Abstract: A system and method for performing a steered push beam (SPB) technique to create multiple foci generated by the interference of different ultrasound push beams to create shear waves and, based thereon, generate a report indicating mechanical properties about an object.

Abstract: Method and system for non-invasive determination of a pressure characteristic associated with carpal tunnel (CT) region of a subject. Speed of a shear wave induced in the tissue of the subject and propagating through the CT region is measured at least once. The pressure characteristic is substantially proportional to determined speed.

Abstract: 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.

Abstract: A system and method for assessing tissue health based on the viscoelastic properties of the tissue. Surface waves are induced in the tissue and their propagation characteristics are then measured. The tissue viscoelastic properties are then determined from the surface wave measurements using a surface model.

Abstract: A system and method for measuring mechanical properties of a tissue using an ultrasound system is provided. Ultrasound energy is applied to the tissue using the ultrasound system in order to produce shear waves that propagate in the tissue. Measurement data are then acquired by directing ultrasound detection pulses into the tissue. Information about the intensity field of the ultrasound energy used to produce the shear waves is obtained and used to produce a correction factor. This correction factor is applied to the measurement data to correct the measurement data for errors arising from the geometry of the ultrasound energy used to produce the shear waves. From the corrected measurement data, mechanical properties of the tissue are calculated.

Abstract: Method and system for non-invasive determination of a pressure characteristic associated with carpal tunnel (CT) region of a subject. Speed of a shear wave induced in the tissue of the subject and propagating through the CT region is measured at least once. The pressure characteristic is substantially proportional to determined speed.

Abstract: A method for measuring a mechanical property of a subject includes using an ultrasonic transducer to apply ultrasonic vibration pulses to a vibration origin in the subject in an on-off time sequence in order to impart a harmonic motion at a prescribed frequency to the subject, and when the vibration pulses are off, preferably using the same transducer to apply ultrasonic detection pulses to a motion detection point and to receive echo signals therefrom in order to sense the harmonic motion on the subject at the motion detection point The ultrasonic detection pulses are interspersed with the vibration pulses and can be applied in a non-uniform manner From the received ultrasonic echo signals, a harmonic signal is detected and a characteristic such as amplitude or phase of the detected harmonic signal is calculated using a Kalman filter or interpolation.

Abstract: Methods for measuring mechanical properties of an object or subject under examination with an ultrasound system and using unfocused ultrasound energy are provided. Shear waves that propagate in the object or subject are produced by applying unfocused ultrasound energy to the object or subject, and measurement data is acquired by applying focused or unfocused ultrasound energy to at least one location in the object or subject at which shear waves are present Mechanical properties are then calculated from the acquired measurement data.

Abstract: A method for generation and analysis of shear waves in a subject with an ultrasound system. Multiple short ultrasound push pulses are applied, as a set and optionally more than once, to one or more push origins at the subject to produce first and second shear waves of large amplitudes and desired spatial distributions, which are separated in space and time and which have opposite polarity such that initial movements of the subject tissue, respectively caused by the first and second shear waves, occur in opposite directions. At least one mechanical property of the subject (including that represented by shear wave group velocity, phase velocity, and attenuation of a shear wave) is determined based at least in part on a distance between wavefronts of the first and second shear waves.

Abstract: A method for measuring a mechanical property of a subject includes using an ultrasound transducer to apply ultrasonic vibration pulses to a location in a subject in order to induce shear waves at multiple prescribed orthogonal frequencies in the subject. The ultrasound transducer is directed by an excitation signal that is composed of multiple orthogonal basis functions, each having a given frequency component corresponding to the prescribed orthogonal frequencies. The power level of each orthogonal basis function is independently adjustable. The excitation signal can be sparsely sampled, or portions of the excitation signal can be removed in order to improve tissue vibration and to provide for the interleaving ultrasonic vibration and detection pulses. Ultrasonic detection pulses are applied to at least one motion detection point, from which echo signals are received. From the received echo signals, a motion signal is determined, from which mechanical properties of the subject are calculated.

Abstract: A model-independent method for producing a viscoelastic tissue property metric using ultrasound is provided. A mechanical stress, such as an acoustic force, is applied to a tissue using an ultrasound system and tissue displacement resulting from the applied acoustic force is measured. From the tissue displacement measurements, a complex modulus, such as a relative complex modulus, is extracted. A loss tangent is calculated from the extracted complex modulus. Using the calculated loss tangent, viscoelastic tissue property metrics may be calculated.

Abstract: A system and method for measuring mechanical properties of a tissue using an ultrasound system is provided. Ultrasound energy is applied to the tissue using the ultrasound system in order to produce shear waves that propagate in the tissue. Measurement data are then acquired by directing ultrasound detection pulses into the tissue. Information about the intensity field of the ultrasound energy used to produce the shear waves is obtained and used to produce a correction factor. This correction factor is applied to the measurement data to correct the measurement data for errors arising from the geometry of the ultrasound energy used to produce the shear waves. From the corrected measurement data, mechanical properties of the tissue are calculated.

Abstract: A method for measuring a mechanical property of a subject includes using an ultrasound transducer to apply ultrasonic vibration pulses to a location in a subject in order to induce shear waves at multiple prescribed orthogonal frequencies in the subject. The ultrasound transducer is directed by an excitation signal that is composed of multiple orthogonal basis functions, each having a given frequency component corresponding to the prescribed orthogonal frequencies. The power level of each orthogonal basis function is independently adjustable. The excitation signal can be sparsely sampled, or portions of the excitation signal can be removed in order to improve tissue vibration and to provide for the interleaving ultrasonic vibration and detection pulses. Ultrasonic detection pulses are applied to at least one motion detection point, from which echo signals are received. From the received echo signals, a motion signal is determined, from which mechanical properties of the subject are calculated.