Abstract: To generate information representing a volume, co-arrays or synthetic transmit aperture process is performed in one dimension and beamforming is performed in another dimension. For example, a transmit aperture focuses in azimuth, but is unfocused or divergent in elevation. A multi-dimensional array receives reflected echoes. The echoes are beamformed for sub-arrays for focus in azimuth. The resulting partial beamformed information is provided to an imaging system from the probe housing for completion of beamforming at least in elevation.

Abstract: Synthetic transmit aperture is provided for three-dimensional ultrasound imaging. A transducer may have separate transmit and receive elements. Broad beams are transmitted, allowing fewer transmit elements and/or more rapid scanning. A multidimensional receive array generates data in response to sequential transmissions, such as transmissions from different angles. The data is combined to increase resolution. A transducer array with offset transmit elements for forming a transmit line source may be used.

Abstract: Presented is a method of operating a capacitive microfabricated ultrasonic transducer (cMUT) array with multiple firings of varying bias voltage polarity patterns to improve its performance in imaging non-linear media, such as in contrast agent imaging or tissue harmonic imaging. Additionally, transducers incorporating the method are provided. The method of cMUT operation and the corresponding cMUT does not require pre-distortion or phase inversion of the transmit signal and can achieve an improvement in the elevation focus of the cMUT, as compared to the elevation focus that a single firing can achieve. Further, the method of operating the cMUT minimizes the deleterious effects that result from insulators being subjected to high electric fields.

Abstract: A single chip transducer apparatus that includes on-chip electronic circuitry which, when connected properly to a two-dimensional matrix of ultrasonic transducer elements, provides enough information to an external imaging system to form three-dimensional images of the subject of interest. In a preferred embodiment, the circuitry provides an amplifier for each transducer element, and then conditions the output of the amplifier in several ways. In one embodiment of the invention, the elements' analog voltages are stored in a sample and hold circuit, and time multiplexed into a high speed line driver that sends many elements data down the interconnect to the system's high speed Analog to Digital converters. In another embodiment, the gain of the amplifiers can be controlled in time to provide aperture translation and time based expansion for translating and focusing image slices in the elevation direction.

Abstract: A capacitive microfabricated transducer array used for 3-D imaging, with a relatively large elevation dimension and a bias control of the elevation aperture in space and time, confers the same benefits of mechanical translation, except that image cross-sections are electronically rather than mechanically scanned, and are registered very accurately in space. The 3-D cMUT, when combined with elevation bias control and convex curvature in elevation, increases the volume interrogated by the electronic scanning, thus improving field of view. Further still, the 3-D cMUT can be combined Fresnel focusing of the elevation section to improve the elevation focus.