Abstract: The invention relates to a method of computed tomography wherein a radiation source moves relative to an examination zone along a helical trajectory and wherein the movement involves a rotation around a rotational axis and a shifting parallel to the rotational axis. During the movement, a detector unit acquires real measured values. Fictitious measured values are determined from the real measured values by solving John's equation for a virtual movement of the radiation source along an intersection ellipse. The intersection ellipse intersects the helical trajectory at an intersection point and is the intersection of a virtual cylindrical surface, on which the helical trajectory is situated, with an intersection plane that is defined by a tangent vector of the helical trajectory at the intersection point and a vector that is oriented perpendicular to the rotational axis. Finally, an image of the examination zone is reconstructed using the real and fictitious measured values.

Abstract: The invention relates to a method of computed tomography wherein a radiation source moves relative to an examination zone along a helical trajectory and wherein the movement involves a rotation around a rotational axis and a shifting parallel to the rotational axis. During the movement, a detector unit acquires real measured values. Fictitious measured values are determined from the real measured values by solving John's equation for a virtual movement of the radiation source along an intersection ellipse. The intersection ellipse intersects the helical trajectory at an intersection point and is the intersection of a virtual cylindrical surface, on which the helical trajectory is situated, with an intersection plane that is defined by a tangent vector of the helical trajectory at the intersection point and a vector that is oriented perpendicular to the rotational axis. Finally, an image of the examination zone is reconstructed using the real and fictitious measured values.

Abstract: The invention relates to a computed tomography method in which a radiation source moves relative to an object on a helical trajectory, where the movement comprises a rotation around an axis of rotation and a displacement parallel to the axis of rotation. During the movement real measured values are acquired by means of a detector unit. First a provisional object image is constructed from the real measured values, from which provisional object image fictitious, non-acquired measured values can be determined by deriving the provisional object image in a direction parallel to the axis of rotation. An image of the examination area is reconstructed from the real and fictitious measured values.

Abstract: Known reconstruction techniques from coherent scattered x-rays apply non-exact reconstruction techniques. According to the present invention, a relatively wide spectrum of wave-vector transfers q of the scattered x-ray photons is acquired. The projection data is interpreted as line integrals in the x y-q space and the projection data is resorted to correspond to an acquisition along any source trajectory. Due to this, an exact helical reconstruction algorithms may be applied and redundant data may be used to obtain a better image quality.

Abstract: A steering system for a boat includes an auxiliary rudder which is rotatable to effect changes in course of the boat. A servo-pendulum rudder is rotatable by a positioning device. When the servo-pendulum rudder is rotated, it is pivotal transversely to a keel line of the boat by water flowing past the boat. A drive connection is provided between the servo-pendulum rudder and the auxiliary rudder. The drive connection includes a drive member and a driven member. One of the driving and driven members is pivotal between an engaged condition in which the drive connection is effective to transmit force between the pendulum rudder and the auxiliary rudder and disengaged condition in which the drive connection is ineffective to transmit force. The drive and driven members may be provided with teeth which are disposed in meshing engagement when the one of the driving and driven members is in the engaged condition.

Abstract: A mounting device for mounting a self-steering system on the stern (40) of a boat at a predefined angle determined from the stern configuration and a desired inclination of the self-steering system, comprises a supporting structure (10) for retaining and connecting the self-steering system with a pair of mounting brackets (20A, 20B) for retaining and connecting the supporting structure (10) with the stern of a boat (40), in which the mounting brackets (20A, 20B) have two first elongated holes (21, 22) extending along at least one approximately circular line for clamping the supporting structure (10) fast with at least four threaded bolts or the like such that its angle can be adjusted.

Abstract: A mounting device for mounting self-steering systems, bathing ladders or other accessories on the stern of boats comprising forked clamps having a front and a rear clamp limb which are integrally connected to each other at their root and which forked clamps having an opening for receiving a connecting means which exerts the clamping effect for connecting the clamp with the stern of the boat and, an elongate receiving zone for receiving and clamping a rail-like retaining element in a position such that it is matched in terms of position and angle between the clamp limb and an element or profiled bar having or forming at least one rail-like enlargement, which enlargement is matched to the elongate receiving zones of the forked clamp such that the enlargement can be inserted into the receiving zone of the forked clamp and can be adjusted and clamped fast in a position by the corresponding forked clamp.