Abstract: Changes in tissue stiffness have long been associated with disease. Systems and methods for determining the stiffness of tissues using ultrasonography may include a device for inducing a propagating shear wave in tissue and tracking the speed of propagation, which is directly related to tissue stiffness and density. The speed of a propagating shear wave may be detected by imaging a tissue at a high frame rate and detecting the propagating wave as a perturbance in successive image frames relative to a baseline image of the tissue in an undisturbed state. In some embodiments, sufficiently high frame rates may be achieved by using a ping-based ultrasound imaging technique in which unfocused omni-directional pings are transmitted (in an imaging plane or in a hemisphere) into a region of interest. Receiving echoes of the omnidirectional pings with multiple receive apertures allows for substantially improved lateral resolution.

Abstract: A Multiple Aperture Ultrasound Imaging (MAUI) probe or transducer is uniquely capable of simultaneous imaging of a region of interest from separate apertures of ultrasound arrays. Some embodiments provide systems and methods for designing, building and using ultrasound probes having continuous arrays of ultrasound transducers which may have a substantially continuous concave curved shape in two or three dimensions (i.e., concave relative to an object to be imaged). Other embodiments herein provide systems and methods for designing, building and using ultrasound imaging probes having other unique configurations, such as adjustable probes and probes with variable configurations.

Abstract: A method of calibrating an ultrasound probe includes mounting an ultrasound probe onto a calibration system, transmitting an ultrasound test signal from an element of the probe through a test medium of the calibration system, and receiving the test signal on a matrix of hydrophones such that an element's position relative to other elements and other arrays within the same probe can be computed. Further, the system described herein is configured to detect the acoustic performance of elements of a probe and report the results to an end user or service provider.

Abstract: Systems and methods of M-mode ultrasound imaging allows for M-mode imaging along user-defined paths. In various embodiments, the user-defined path can be a non-linear path or a curved path. In some embodiments, a system for M-mode ultrasound imaging can comprise a multi-aperture probe with at least a first transmitting aperture and a second receiving aperture. The receiving aperture can be separate from the transmitting aperture. In some embodiments, the transmitting aperture can be configured to transmit an unfocused, spherical, ultrasound ping signal into a region of interest. The user-defined path can define a structure of interest within the region of interest.

Abstract: A Multiple Aperture Ultrasound Imaging (MAUI) probe or transducer is uniquely capable of simultaneous imaging of a region of interest from separate apertures of ultrasound arrays. Some embodiments provide systems and methods for designing, building and using ultrasound probes having continuous arrays of ultrasound transducers which may have a substantially continuous concave curved shape in two or three dimensions (i.e. concave relative to an object to be imaged). Other embodiments herein provide systems and methods for designing, building and using ultrasound imaging probes having other unique configurations, such as adjustable probes and probes with variable configurations.

Abstract: A Multiple Aperture Ultrasound Imaging system and methods of use are provided with any number of features. In some embodiments, a multi-aperture ultrasound imaging system is configured to transmit and receive ultrasound energy to and from separate physical ultrasound apertures. In some embodiments, a transmit aperture of a multi-aperture ultrasound imaging system is configured to transmit an omni-directional unfocused ultrasound waveform approximating a first point source through a target region. In some embodiments, the ultrasound energy is received with a single receiving aperture. In other embodiments, the ultrasound energy is received with multiple receiving apertures. Algorithms are described that can combine echoes received by one or more receiving apertures to form high resolution ultrasound images. Additional algorithms can solve for variations in tissue speed of sound, thus allowing the ultrasound system to be used virtually anywhere in or on the body.

Abstract: A Multiple Aperture Ultrasound Imaging (MAUI) probe or transducer is uniquely capable of simultaneous imaging of a region of interest from separate apertures of ultrasound arrays. Some embodiments provide systems and methods for designing, building and using ultrasound probes having continuous arrays of ultrasound transducers which may have a substantially continuous concave curved shape in two or three dimensions (i.e., concave relative to an object to be imaged). Other embodiments herein provide systems and methods for designing, building and using ultrasound imaging probes having other unique configurations, such as adjustable probes and probes with variable configurations.

Abstract: Increasing the effective aperture of an ultrasound imaging probe by including more than one probe head and using the elements of all of the probes to render an image can greatly improve the lateral resolution of the generated image. In order to render an image, the relative positions of all of the elements must be known precisely. A calibration fixture is described in which the probe assembly to be calibrated is placed above a test block and transmits ultrasonic pulses through the test block to an ultrasonic sensor. As the ultrasonic pulses are transmitted though some or all of the elements in the probe to be tested, the differential transit times of arrival of the waveform are measured precisely. From these measurements the relative positions of the probe elements can be computed and the probe can be aligned.

Abstract: A Multiple Aperture Ultrasound Imaging system and methods of use are provided with any number of features. In some embodiments, a multi-aperture ultrasound imaging system is configured to transmit and receive ultrasound energy to and from separate physical ultrasound apertures. In some embodiments, a transmit aperture of a multi-aperture ultrasound imaging system is configured to transmit an omni-directional unfocused ultrasound waveform approximating a first point source through a target region. In some embodiments, the ultrasound energy is received with a single receiving aperture. In other embodiments, the ultrasound energy is received with multiple receiving apertures. Algorithms are described that can combine echoes received by one or more receiving apertures to form high resolution ultrasound images. Additional algorithms can solve for variations in tissue speed of sound, thus allowing the ultrasound system to be used virtually anywhere in or on the body.

Abstract: A Multiple Aperture Ultrasound Imaging (MAUI) probe or transducer is uniquely capable of simultaneous imaging of a region of interest from separate apertures of ultrasound arrays. Some embodiments provide systems and methods for designing, building and using ultrasound probes having continuous arrays of ultrasound transducers which may have a substantially continuous concave curved shape in two or three dimensions (i.e., concave relative to an object to be imaged). Other embodiments herein provide systems and methods for designing, building and using ultrasound imaging probes having other unique configurations, such as adjustable probes and probes with variable configurations.

Abstract: A Multiple Aperture Ultrasound Imaging (MAUI) probe or transducer is uniquely capable of simultaneous imaging of a region of interest from separate physical apertures. Construction of probes can vary by medical application. That is, a general radiology probe can contain multiple transducers that maintain separate physical points of contact with the patient's skin, allowing multiple physical apertures. A cardiac probe may contain only two transmitters and receivers where the probe fits simultaneously between two or more intracostal spaces. An intracavity version of the probe can space transmit and receive transducers along the length of the wand, while an intravenous version can allow transducers to be located on the distal length the catheter and separated by mere millimeters. Algorithms can solve for variations in tissue speed of sound, thus allowing the probe apparatus to be used virtually anywhere in or on the body.

Abstract: The benefits of a multi-aperture ultrasound probe can be achieved with add-on devices. Synchronization and correlation of echoes from multiple transducer elements located in different arrays is essential to the successful processing of multiple aperture imaging. The algorithms disclosed here teach methods to successfully process these signals when the transmission source is coming from another ultrasound system and synchronize the add-on system to the other ultrasound system. Two-dimensional images with different noise components can be constructed from the echoes received by individual transducer elements. The disclosed techniques have broad application in medical imaging and are ideally suited to multi-aperture cardiac imaging using two or more intercostal spaces.

Abstract: A multiple aperture ultrasound imaging system may be configured to store raw, un-beamformed echo data. Stored echo data may be retrieved and re-beamformed using modified parameters in order to enhance the image or to reveal information that was not visible or not discernible in an original image. Raw echo data may also be transmitted over a network and beamformed by a remote device that is not physically proximate to the probe performing imaging. Such systems may allow physicians or other practitioners to manipulate echo data as though they were imaging the patient directly, even without the patient being present. Many unique diagnostic opportunities are made possible by such systems and methods.

Abstract: The benefits of a multi-aperture ultrasound probe can be achieved with add-on devices. Synchronization and correlation of echoes from multiple transducer elements located in different arrays is essential to the successful processing of multiple aperture imaging. The algorithms disclosed here teach methods to successfully process these signals when the transmission source is coming from another ultrasound system and synchronize the add-on system to the other ultrasound system. Two-dimensional images with different noise components can be constructed from the echoes received by individual transducer elements. The disclosed techniques have broad application in medical imaging and are ideally suited to multi-aperture cardiac imaging using two or more intercostal spaces.

Abstract: Increasing the effective aperture of an ultrasound imaging probe by including more than one probe head and using the elements of all of the probes to render an image can greatly improve the lateral resolution of the generated image. In order to render an image, the relative positions of all of the elements must be known precisely. A calibration fixture is described in which the probe assembly to be calibrated is placed above a test block and transmits ultrasonic pulses through the test block to an ultrasonic sensor. As the ultrasonic pulses are transmitted though some or all of the elements in the probe to be tested, the differential transit times of arrival of the waveform are measured precisely. From these measurements the relative positions of the probe elements can be computed and the probe can be aligned.

Abstract: Systems and methods for improving the quality of ultrasound images made up of a combination of multiple sub-images include giving more weight to sub-image information that is more likely to improve a combined image quality. Weighting factor information may be determined from the geometry (e.g., angle or path length) of a location of one or more specific transducer elements relative to a specific point within a region of interest or a region of an image. In some embodiments, any given pixel (or other discrete region of an image) may be formed by combining received echo data in a manner that gives more weight to data that is likely to improve image quality, and/or discounting or ignoring data that is likely to detract from image quality (e.g., by introducing noise or by increasing point spread).

Abstract: Changes in tissue stiffness have long been associated with disease. Systems and methods for determining the stiffness of tissues using ultrasonography may include a device for inducing a propagating shear wave in tissue and tracking the speed of propagation, which is directly related to tissue stiffness and density. The speed of a propagating shear wave may be detected by imaging a tissue at a high frame rate and detecting the propagating wave as a perturbance in successive image frames relative to a baseline image of the tissue in an undisturbed state. In some embodiments, sufficiently high frame rates may be achieved by using a ping-based ultrasound imaging technique in which unfocused omni-directional pings are transmitted (in an imaging plane or in a hemisphere) into a region of interest. Receiving echoes of the omnidirectional pings with multiple receive apertures allows for substantially improved lateral resolution.

Abstract: Systems and methods of M-mode ultrasound imaging allows for M-mode imaging along user-defined paths. In various embodiments, the user-defined path can be a non-linear path or a curved path. In some embodiments, a system for M-mode ultrasound imaging can comprise a multi-aperture probe with at least a first transmitting aperture and a second receiving aperture. The receiving aperture can be separate from the transmitting aperture. In some embodiments, the transmitting aperture can be configured to transmit an unfocused, spherical, ultrasound ping signal into a region of interest. The user-defined path can define a structure of interest within the region of interest.

Abstract: Increasing the effective aperture of an ultrasound imaging probe by including more than one probe head and using the elements of all of the probes to render an image can greatly improve the lateral resolution of the generated image. In order to render an image, the relative positions of all of the elements must be known precisely. A calibration fixture is described in which the probe assembly to be calibrated is placed above a test block and transmits ultrasonic pulses through the test block to an ultrasonic sensor. As the ultrasonic pulses are transmitted though some or all of the elements in the probe to be tested, the differential transit times of arrival of the waveform are measured precisely. From these measurements the relative positions of the probe elements can be computed and the probe can be aligned.

Abstract: A method of full-field or “ping-based” Doppler ultrasound imaging allows for detection of Doppler signals indicating moving reflectors at any point in an imaging field without the need to pre-define range gates. In various embodiments, such whole-field Doppler imaging methods may include transmitting a Doppler ping from a transmit aperture, receiving echoes of the Doppler ping with one or more separate receive apertures, detecting Doppler signals and determining the speed of moving reflectors. In some embodiments, the system also provides the ability to determine the direction of motion by solving a set of simultaneous equations based on echo data received by multiple receive apertures.