Abstract: Systems and methods are provided whereby a directional property of an ultrasound transducer element, such as a steering direction, is controlled according to a first driving waveform that is delivered to opposing propagation electrodes and a second driving waveform that is delivered to opposing lateral electrodes. The directional property may be controlled according a phase difference and/or relative amplitude between the first and second driving waveforms, and/or the selective actuation of one or more lateral electrodes when the lateral electrodes are defined in an array. The ultrasound transducer element may be a ring-shaped transducer element and a directional property associated with a focal region may be controlled. In some example embodiments, array elements of an ultrasound transducer array may each include propagation and lateral electrodes, with each array element being driven by respective first and second driving waveforms to focus the ultrasound energy emitted by the ultrasound transducer array.

Abstract: Methods and devices are described for driving ferroelectric perovskite oxide crystals to achieve polarization inversion with reduced coercivity. In some embodiments, the anisotropy in the potential energy surface of a ferroelectric material is employed to drive polarization inversion and switching with a reduced coercive field relative to uniaxial excitation. In some embodiments, polarization inversion with reduced coercivity is produced via the application of an electric field that exhibits a time-dependent orientation, in contrast with conventional uniaxial electrical excitation, thereby causing the central ion (and the crystal structure as a whole) to evolve along a lower-energy path, in which the central ion is driven such that it avoids the potential energy maximum. This may be achieved, for example, by applying at least two non-parallel time-dependent voltages (e.g. bias, potential) such that orientation of the electric field changes with time during the switching cycle.

Abstract: Methods and devices are described for driving ferroelectric perovskite oxide crystals to achieve polarization inversion with reduced coercivity. In some embodiments, the anisotropy in the potential energy surface of a ferroelectric material is employed to drive polarization inversion and switching with a reduced coercive field relative to uniaxial excitation. In some embodiments, polarization inversion with reduced coercivity is produced via the application of an electric field that exhibits a time-dependent orientation, in contrast with conventional uniaxial electrical excitation, thereby causing the central ion (and the crystal structure as a whole) to evolve along a lower-energy path, in which the central ion is driven such that it avoids the potential energy maximum. This may be achieved, for example, by applying at least two non-parallel time-dependent voltages (e.g. bias, potential) such that orientation of the electric field changes with time during the switching cycle.

Abstract: A method for treating a varicose vein comprises heating a dehiscent portion of a wall of the vein so as to produce a localized retraction of collagen. Heating may be via application of high-intensity focused ultrasound energy.

Abstract: The inventive ultrasound treating device comprises a first processing transducer set (11) for transmitting a beam of high-intensity ultrasound waves to a treatable area (3), wherein said beam comprises an aspheric wavefront and forms a focal spot (6) on the treatable area elongated and inclined with respect to the direction of the ultrasound wave propagation and the focal spot (6) length is less than the length of the transducer (11). The inventive device is particularly suitable for treating an elongated area such as vein portions enveloping a pathological valve.

Abstract: The inventive ultrasound treating device comprises a first processing transducer set (11) for transmitting a beam of high-intensity ultrasound waves to a treatable area (3), wherein said beam comprises an aspheric wavefront and forms a focal spot (6) on the treatable area elongated and inclined with respect to the direction of the ultrasound wave propagation and the focal spot (6) length is less than the length of the transducer (11). The inventive device is particularly suitable for treating an elongated area such as vein portions enveloping a pathological valve.