Abstract: A micro-machined ultrasonic transducer (MUT) having aperture, elevation and apodization controlled by apparatus located on the same substrate as the transducer, or by bias voltage control applied to MUT elements, allows for an efficient and compact ultrasonic probe. The control apparatus may take the form of field effect transistors (FET's), micro-machined relays, or doped regions on the substrate, or any other apparatus that may be located on the same substrate as that of the transducer, or by bias voltage sources connected to the MUT elements.

Abstract: Integrated circuitry for use with an ultrasound transducer of an ultrasound imaging system is disclosed. According to one embodiment of the invention, unique transducer circuitry comprises a low-voltage circuit and a high-voltage circuit including at least one high-voltage FET to drive an ultrasound transducer element. The low-voltage circuit and the high-voltage circuit are monolithically formed on a single substrate. The low-voltage circuit may include high density digital logic circuitry to generate transmit signals to the transducer element, as well as low noise analog receive circuitry to process signals received from the transducer element. The high-voltage FET of the high-voltage circuit comprises a lightly-doped drain region to increase the breakdown voltage of the high-voltage FET. The low and high-voltage circuits may be fabricated together on a single substrate using conventional low-voltage CMOS processing techniques.

Abstract: A plurality of applications for a micro-machined ultrasonic transducer (MUT) including an improved MUT array containing optimized transmit MUT elements and optimized receive MUT elements, a MUT array in which staggered MUT elements increase the sensitivity of the array, and a MUT array for multiple plane scanning.

Abstract: A circuit and method for predistorting an input pulse to a micro-machined ultrasonic transducer (MUT) compensates for non-linearities in the transducer, thus allowing the transducer to provide a compensated output pressure wave having a low second order harmonic transmit energy. In another aspect of the invention, the output power of a MUT may be controlled.

Abstract: Methods and apparatus for transmitting ultrasound energy having low harmonic content and for detecting harmonic reflections of the ultrasound energy are disclosed. According to the invention, the capacitance of an ultrasound transducer element, as well as any interconnection capacitance associated with one or more signal conductors attached to the transducer element, is utilized as part of a filter which conditions one or more electronic drive signals to provide an ultrasound transmit waveform having low harmonic content. Such a low harmonic content ultrasound transmit waveform may be used to expose a region of interest in a patient which reflects harmonics of the transmit waveform. Receive circuitry detects the harmonic reflections and generates an ultrasound image having improved contrast and reduced distortion.

Abstract: The disclosed ultrasound imaging apparatus and method use a transducer array with a very large number of transducer elements or a transducer array with many more transducer elements than beamformer channels. The imaging apparatus includes a transmit array including a multiplicity of transducer elements allocated into several transmit sub-arrays, and a receive array including a multiplicity of transducer elements allocated into several receive sub-arrays. The apparatus also includes several intra-group transmit processors, connected to the transmit sub-arrays, constructed and arranged to generate a transmit acoustic beam directed into a region of interest, and several intra-group receive processors connected to the receive sub-arrays. Each intra-group receive processor is arranged to receive, from the transducer elements of the connected sub-array, transducer signals in response to echoes from the transmit acoustic beam.

Abstract: An ultrasound imaging system includes a two-dimensional array of ultrasound transducer elements that define multiple subarrays, a transmitter for transmitting ultrasound energy into a region of interest with transmit elements of the array, a subarray processor and a phase shift network associated with each of the subarrays, a primary beamformer and an image generating circuit. Each subarray processor includes receive circuitry responsive to transducer signals generated by receive elements of the associated subarray for providing first and second subarray signals. The first subarray signal comprises a sum of first component signals, and the second subarray signal comprises a sum of second component signals. The first and second component signals are derived from the respective transducer signals. The phase shift network phase shifts and combines the first and second subarray signals to provide a phase shifted subarray signal.

Abstract: The disclosed ultrasound imaging apparatus and method use a transducer array with a very large number of transducer elements or a transducer array with many more transducer elements than beamformer channels. The imaging apparatus includes a transmit array including a multiplicity of transducer elements allocated into several transmit sub-arrays, and a receive array including a multiplicity of transducer elements allocated into several receive sub-arrays. The apparatus also includes several intra-group transmit processors, connected to the transmit sub-arrays, constructed and arranged to generate a transmit acoustic beam directed into a region of interest, and several intra-group receive processors connected to the receive sub-arrays. Each intra-group receive processor is arranged to receive, from the transducer elements of the connected sub-array, transducer signals in response to echoes from the transmit acoustic beam.

Abstract: Ultrasound image data representative of three-dimensional volume segments of an image volume of interest is acquired in synchronism with corresponding cardiac cycles of a patient. The image data representative of the volume segments is combined to provide image data representative of a three-dimensional image of the image volume. The image data acquisition may be synchronized to a selected phase of the patient's cardiac cycle, so that the image represents the image volume at the selected phase. Image data for a three-dimensional volume segment may be acquired during each of the cardiac phases of a cardiac cycle.

Abstract: In a magnetic resonance method for imaging of a moving part of a body (106) temporary magnetic gradient fields (230) are applied and a echo signal (641, 642) is obtained after an excitation pulse (201). An image of the moving part is reconstructed from the received echo signals (240). The moving part introduces artefacts in the reconstructed image. These artefacts could be reduced when the instantaneous position of the moving part is known and the region of the moving part to be excited is adjusted according to this instantaneous position. This instantaneous position is derived from navigator signals (640). These navigator signals (640) could be generated independently from the other echo signals (641, 642) in the moving part of the body. A further reduction of artefacts in the image could be obtained by deriving a phase correction and a frequency correction from the navigator signals (640) and to apply the derived corrections to the received echo signals (641, 642).

Abstract: Scan conversion or data interpolation is performed on the signal generated by acoustic transducers in an acoustic imaging system before the signal is processed by detecting and limiting it. This processing uses signal phase information, which is normally lost during the image reconstruction process, to increase image resolution. A nonlinear interpolation scheme is used during the scan conversion process used to convert the data generated by acoustic transducers into data suitable for visual display in order to more accurately generate interpolated data points. A nonlinear angular spacing between acoustic lines is used to increase the image frame rate can be increased without decreasing image resolution. The frame rate of the acoustic imaging system can also be increased by interpolating the signals generated by the transducers before they are provided to beamforming circuits.

Abstract: Scan conversion or data interpolation is performed on the signal generated by acoustic transducers in an acoustic imaging system before the signal is processed by detecting and limiting it. This processing uses signal phase information, which is normally lost during the image reconstruction process, to increase image resolution. A nonlinear interpolation scheme is used during the scan conversion process used to convert the data generated by acoustic transducers into data suitable for visual display in order to more accurately generate interpolated data points. A nonlinear angular spacing between acoustic lines is used to increase the image frame rate can be increased without decreasing image resolution. The frame rate of the acoustic imaging system can also be increased by interpolating the signals generated by the transducers before they are provided to beamforming circuits.

Abstract: Scan conversion or data interpolation is performed on the signal generated by acoustic transducers in an acoustic imaging system before the signal is processed by detecting and limiting it. This processing uses signal phase information, which is normally lost during the image reconstruction process, to increase image resolution. A nonlinear interpolation scheme is used during the scan conversion process used to convert the data generated by acoustic transducers into data suitable for visual display in order to more accurately generate interpolated data points. A nonlinear angular spacing between acoustic lines is used to increase the image frame rate can be increased without decreasing image resolution. The frame rate of the acoustic imaging system can also be increased by interpolating the signals generated by the transducers before they are provided to beamforming circuits.

Abstract: Apparatus for calculating the delay coefficients to be used for the transducer of a linear array at successive focal points along each radial line of a sector along which ultrasonic pulses are transmitted comprising a plurality of clocked accumulators connected in series, the accumulators being preloaded with appropriate combination of the coefficients of the successive terms of a series expressing an approximation of the formula, D=R-.sqroot.(X-Xo).sup.2 +Yo.sup.2 where R is the distance of a focal point from a given point in the sector, X is the number of the accumulator from the origin and Xo, Yo are the coordinates of the focal point.

Abstract: This invention provides an ultrasonic transducer system which utilizes a reconfigurable delay line to perform a variety of processing functions. In particular, for a preferred embodiment, the delay line utilized to sum the outputs of transducer elements is reconfigurable to provide serial processing of image scan lines while providing parallel processing of Doppler color flow scan lines. More particularly, the echo signals generated in response to the packet of color flow lines utilized to generate color flow information are applied in a predetermined way to two separate portions of the delay line, the portions of the delay line having different delay profiles, the resulting outputs being focussed to slightly different points in the image and thus providing color flow packets for two separate points in response to the transmission of a single packet of color flow lines. This results in a substantial enhancement of the system frame rate.

Abstract: The errors in phase produced by differences in the locations of taps on a delay line are compensated by determining the error by transmitting oscillations from a test oscillator through each tap and storing the difference between the actual phase and the ideal phase that would result if the taps were perfectly located. When an ideal delay is called for, the tap having the closest actual delay to the ideal delay is selected and the proper phase correction is made.