Abstract: The invention presents solutions for large apertures of an ultrasound array under given dimension constraints given by the application for the ultrasound probe, for example by an endoluminal application. The invention has applications to annular arrays for 2D and 3D imaging, and also to linear or curvilinear arrays for 2D and 3D imaging. The invention further provides large aperture of arrays for dual frequency band operation with large difference between the dual bands.

Abstract: An estimation method for correction filters for wavefront aberration correction in ultrasound imaging is given. The aberration is introduced due to spatial variations of the ultrasound propagation velocity in heterogeneous tissue. The correction filters are found as eigenvectors of the cross-correlation matrix of the element signals. In particular, the eigenvectors with a small spatial linear/plane phase component is sought. Detailed methods for calculating the eigenvectors are given.

Abstract: A method of correcting for pulse reverberations in ultrasound imaging using two-dimensional transducer arrays, and uses such reduction in element signals and beam signal before estimation of corrections for phase front aberrations of the ultrasound wave. The pulse reverberation is estimated by two transmit events, where the second event is determined by measurement and processing on measurement on echoes of the first event. In a second embodiment of the invention, the reverberation is estimated by a single transmit event, using two receive beams and processing on these. In a third embodiment of the invention the reverberation from very strong scatterers is reduced by adjustment of the active transmit aperture.

Abstract: A method for improved detection and imaging of ultrasound contrast agents using dual-band transmitted pulses, is described. The method is based on transmitting a pulse consisting of two frequency bands, a low frequency band which purpose is to manipulate the high frequency scattering properties of the contrast agent, and a high frequency band from which the image reconstruction is based. In addition, a general form of pulse subtraction is used to significantly suppress the received tissue signal.

Abstract: The invention composes a method and instrumentation for ultrasound stimulation of the hybridization reaction in gene expression microarray test chambers (or hybridization stations). The microarray or gene chip with the DNA molecules solution added on the surface, is mounted in a system that allows transmission of ultrasound waves into the DNA solution.

Abstract: A method for improved detection and imaging of ultrasound contrast agents using dual-band transmitted pulses, is described. The method is based on transmitting a pulse consisting of two frequency bands, a low frequency band which purpose is to manipulate the high frequency scattering properties of the contrast agent, and a high frequency band from which the image reconstruction is based. In addition, a general form of pulse subtraction is used to significantly suppress the received tissue signal.

Abstract: A method for improved imaging of ultrasound contrast agent using dual frequency band transmitted pulses is described. The method is based on transmitting a dualband pulse consisting of two frequency bands, preferably a fundamental band and its second harmonic band. In addition, a general pulse inversion method is applied to reduce or cancel first order nonlinear harmonic tissue signal components introduced due to the transmission of dualband pulses.

Abstract: An ultrasound probe capable of scanning an ultrasound beam in a region of 3D space, characterized by that an ultrasound transducer array is mounted to a 1st shaft that can rotate in bearings mounted in a fork that can be moved. The fork can be rotated around a 2nd shaft in a bearing, or moved through a sliding system, or a combination of the two. The shaft and the fork are connected to two separate electric motors for electric steering of the array direction within a region of 3D space. Position measurement systems are mounted to the shaft and the fork so that the beam direction can be steered with a feed-back control system.

Abstract: A design and a manufacturing method of ultrasound transducers based on films of ferro-electric ceramic material is presented, the transducers being particularly useful for operating at frequencies above 10 MHz. The designs also involve acoustic load matching layers that provides particularly wide bandwidth of the transducers, and also multiple electric port transducers using multiple piezoelectric layers, for multi-band operation of the transducers over an even wider band of frequencies that covers ˜4 harmonics of a fundamental band. A transceiver drive system for the multi-port transducers that provides simple selection of the frequency bands of transmitted pulses as well as transmission of multi-band pulses, and reception of scattered signals in multiple frequency bands, is presented.

Abstract: A method of real time ultrasound imaging of an object in at least three two-dimensional scan planes that are rotated around a common axis, is given, together with designs of ultrasound transducer arrays that allows for such imaging. The method is also introduced into a monitoring situation of cardiac function where, combined with other measurements as for example the LV pressure, physiological parameters like ejection fraction and muscular fiber stress is calculated.

Abstract: Ultrasound bulk wave transducers and bulk wave transducer arrays for wide band or multi frequency band operation, in which the bulk wave is radiated from a front surface and the transducer is mounted on a backing material with sufficiently high absorption that reflected waves in the backing material can be neglected. The transducer is formed of layers that include a high impedance section comprised of at least one piezoelectric layer covered with electrodes to form an electric port, and at least one additional elastic layer, with all of the layers of the high impedance section having substantially the same characteristic impedance to yield negligible reflection between the layers. The transducer further includes a load matching section comprised of a set of elastic layers for impedance matching between the high impedance section and the load material and, optionally, impedance matching layers between the high impedance section and the backing material for shaping the transducer frequency response.

Abstract: A method of correcting for pulse reverberations in ultrasound imaging using two-dimensional transducer arrays, and uses such reduction in element signals and beam signal before estimation of corrections for phase front aberrations of the ultrasound wave. The pulse reverberation is estimated by two transmit events, where the second event is determined by measurement and processing on measurement on echoes of the first event. In a second embodiment of the invention, the reverberation is estimated by a single transmit event, using two receive beams and processing on these. In a third embodiment of the invention the reverberation from very strong scatterers is reduced by adjustment of the active transmit aperture.

Abstract: An annular ultrasound bulk wave transducer array for electronic depth steering of symmetric focus from a near focus Fn to a far focus Ff includes elements that are divided into k groups with different fixed prefocusing. The central group participates in beam forming from Fn to Ff, the next outer group in beam forming from Fn1>Fn to Ff, and the kth outer group in beam forming from Fnk>Fn,k−1 to Ff. The fixed focus for the kth group is selected at Fk between Fnk and Ff. In this manner, beam formation close to Fn is performed only by the central group. By steering the focus outward from Fn, the focal diameter increases and, at a depth where the focal diameter exceeds a limit, the next outer group of elements is included in beam formation. This increase in aperture area reduces the focal diameter with subsequent increases in diameter as the focus is further steered toward Ff.

Abstract: An advantageous combination of preamplifier electronics and circuits for acoustic beam forming with ultrasound transducer arrays permits integration of the electronics and transducer(s) at close distances in a compact arrangement and is operable from an ultrasound imaging or measurement system using only a minimal number of connecting electric wires. To achieve dynamic focusing of the receive beam with a transducer array, an integrated electronic circuit mounted in close proximity to the transducer array provides preamplifiers for the individual elements and delay circuits that are automatically switched in a predetermined time sequence after transmission of an imaging pulse. When a high voltage pulse is transmitted via the cable, a breakthrough circuit connects the cable to the transducer for transmission of the ultrasound pulse, while in receive mode the low level signal on the transducer is amplified and fed as a higher level signal via the same cable to the imaging or measurement instrument.

Abstract: A design and a manufacturing method of ultrasound transducers based on films of ferro-electric ceramic material is presented, the transducers being particularly useful for operating at frequencies above 10 MHz. The designs also involve acoustic load matching layers that provides particularly wide bandwidth of the transducers, and also multiple electric port transducers using multiple piezoelectric layers, for multi-band operation of the transducers over an even wider band of frequencies that covers ˜4 harmonics of a fundamental band. A transceiver drive system for the multi-port transducers that provides simple selection of the frequency bands of transmitted pulses as well as transmission of multi-band pulses, and reception of scattered signals in multiple frequency bands, is presented.

Abstract: An ultrasound probe capable of scanning an ultrasound beam in a region of 3D space, characterized by that an ultrasound transducer array is mounted to a 1st shaft that can rotate in bearings mounted in a fork that can be moved. The fork can be rotated around a 2nd shaft in a bearing, or moved through a sliding system, or a combination of the two. The shaft and the fork are connected to two separate electric motors for electric steering of the array direction within a region of 3D space. Position measurement systems are mounted to the shaft and the fork so that the beam direction can be steered with a feed-back control system.

Abstract: A method of correcting for phasefront aberrations in ultrasound imaging uses highly spaced apart point scatterers artificially placed in the tissue being imaged. The point scatterers reflect the transmitted sound and are individually differentiated to provide singular reference points for correction of signals reflected from the surrounding tissue. The differentiation is performed by comparison of the third or fourth harmonic frequencies of the reflected signals. To ensure the necessary high dispersal of the point scatterers, high amplitude pulses of the transmitted signal destroy point scatterers in selected image regions. In an alternate embodiment, correction is performed by stochastic analysis of signals reflected from the highly dispersed point scatterers. A reference signal is compared to the second harmonic of the reflected signal to reduce noise.

Abstract: Ultrasound bulk wave transducers and bulk wave transducer arrays for wide band or multi frequency band operation, in which the bulk wave is radiated from a front surface and the transducer is mounted on a backing material with sufficiently high absorption that reflected waves in the backing material can be neglected. The transducer is formed of layers that include a high impedance section comprised of at least one piezoelectric layer covered with electrodes to form an electric port, and at least one additional elastic layer, with all of the layers of the high impedance section having substantially the same characteristic impedance to yield negligible reflection between the layers. The transducer further includes a load matching section comprised of a set of elastic layers for impedance matching between the high impedance section and the load material and, optionally, impedance matching layers between the high impedance section and the backing material for shaping the transducer frequency response.

Abstract: An annular ultrasound bulk wave transducer array for electronic depth steering of symmetric focus from a near focus Fn to a far focus Ff includes elements that are divided into k groups with different fixed prefocusing. The central group participates in beam forming from Fn to Ff, the next outer group in beam forming from Fn1>Fn to Ff, and the kth outer group in beam forming from Fnk>Fn,k-1 to Ff. The fixed focus for the kth group is selected at Fk between Fnk and Ff. In this manner, beam formation close to Fn is performed only by the central group. By steering the focus outward from Fn, the focal diameter increases and, at a depth where the focal diameter exceeds a limit, the next outer group of elements is included in beam formation. This increase in aperture area reduces the focal diameter with subsequent increases in diameter as the focus is further steered toward Ff.

Abstract: A method of correcting for phasefront aberrations in ultrasound imaging uses highly spaced apart point scatterers artificially placed in the tissue being imaged. The point scatterers reflect the transmitted sound and are individually differentiated to provide singular reference points for correction of signals reflected from the surrounding tissue. The differentiation is performed by comparison of the third or fourth harmonic frequencies of the reflected signals. To ensure the necessary high dispersal of the point scatterers, high amplitude pulses of the transmitted signal destroy point scatterers in selected image regions. In an alternate embodiment, correction is performed by stochastic analysis of signals reflected from the highly dispersed point scatterers. A reference signal is compared to the second harmonic of the reflected signal to reduce noise.