Abstract: An array comprising at least one row of ultrasonic elements when energized generates a pressure pattern having side lobes when viewed in the lateral direction. Those side lobes give rise to undesirable grating lobes. The side lobes in both transverse and lateral direction can be suppressed by having identical and identically arranged ultrasonic elements (14) the width of which, viewed in the lateral direction, is greater than the pitch of the consecutive ultrasonic elements in the row.

Abstract: An ultrasound transducer generates a received signal in response to a reflected ultrasound signal. Polarity and phase information of the reflected ultrasound signal can be obtained by time-selectively amplifying the received signal with a specific gain function. The specific gain function is derived from the received signal itself and is independent of the polarity of the received signal.

Abstract: The housing of an elongated proximity-focus image intensifier comprises at least two elongated parts. The parts have in cross-section such dimensions and such a configuration that the housing is self-supporting. An exemplary embodiment of such a housing which is essentially rectangular in cross-section has a front wall, a rear wall and two side walls, all having an essentially rectangular cross-section. In the case of at least two pairs of adjacent walls the edge in the longitudinal direction of the surface, facing the interior of the housing, of a first of the pair of walls is provided with profiling in the form of a recessed section in which the longitudinal edge of the adjacent tube wall is received.

Abstract: An apparatus for the non-contact disintegration of concrements present in a body by means of sound shock waves generated by spark discharge between two electrodes in a focus of at least one liquid-filled rotationally symmetrical reflector formed in a reflector block, said sound shock waves being focussed in a focal point situated outside the reflector. Between the focus F.sub.1 and the focal point F.sub.2, in a region .beta. bounded by an imaginary conical surface defined by the edge R of the reflector 2 and the focus F.sub.1, there is positioned an object intercepting sound shock waves impinging thereon.