摘要:
A method for determining the center of rotation of a bone in a revolute joint, for example, a femur in the iliac bone, including the steps of displacing said bone, locating several ones of its positions, and memorizing them, imposing a constraint to the displacement of said center of rotation without for all this immobilizing it, and searching a point linked to the referential of said bone for which an optimization criterion taking into account said constraint is reached.
摘要:
A three-dimensional energy distribution device includes a volume reacting to the energy of a predetermined radiation; a plurality of sources of the radiation illuminating the volume according to respective angles; and, placed between each source and the volume, a support that is transparent to the radiation and that includes an image corresponding to a density projection of a real or virtual object examined at the angle the respective source illuminates the volume, the projection having been subjected to an image correction process.
摘要:
The invention relates to a method for the determination of the position of a radiographic or radioscopic unit (16) with relation to a reference point (Rref) on producing a radiographic image of an object (10). The position of the unit (16) with relation to a reference point (Rref) is determined from the determination of the position of a test pattern (25), with relation to the unit (16), which is mechanically fixed to the object, by using the image of the test pattern with relation to the reference point (Rref). The invention further relates to a determining device for carrying out said method.
摘要翻译:本发明涉及一种用于在产生物体(10)的射线照相图像时确定射线照相或者放射线单元(16)相对于参考点(R SUB ref)的位置的方法。 根据测试图案(25)的位置与单元(16)的确定来确定单元(16)相对于参考点(R SUB ref)的位置, 通过使用相对于参考点(R REF)的测试图案的图像,机械地固定到对象。 本发明还涉及一种用于执行所述方法的确定装置。
摘要:
The invention relates to a method for the determination of the position of a radiographic or radioscopic unit (16) with relation to a reference point (Rref) on producing a radiographic image of an object (10). The position of the unit (16) with relation to a reference point (Rref) is determined from the determination of the position of a test pattern (25), with relation to the unit (16), which is mechanically fixed to the object, by using the image of the test pattern with relation to the reference point (Rref). The invention further relates to a determining device for carrying out said method.
摘要:
Sets of projections of measurements through an object (1) the image of which is to be represented, undergo Fourier transforms before being broken down into blocks according to cutoff frequencies. The blocks are separately reconstructed in order to form a series of thumbnail images of the object, which are then combined in order to reconstruct the final image. The reconstruction calculations on the thumbnail images are rapid and often a large portion of the blocks will be discarded, notably those which are at high frequencies, whereby their contribution may frequently be neglected as well as the noise effects which accumulate therein.The invention is applied to medical or industrial tomography methods and is of larger interest for mobile objects, the movement of which may be estimated and compensated.
摘要:
The invention concerns a method and a system for three-dimensional reconstruction of an image representing the surface contours of at least an object (1), from at least a two-dimensional view of said object obtained by X-ray, which consists in: determining the position of the photographing source (7) in a reference repository; selecting a predefined model constituting a mean form of the object, and repeating the process until the contours of the model are such that the variations between the overhead projection rays of the contours of the two-dimensional image from the source and the model surface are minimal; selecting an orientation and a position for the model in the reference repository; then selecting a deformation of the model to modify its contours in three dimensions.
摘要:
A calculation for reconstructing tomographic images involves the decomposition of two-dimensional sets of projections of this image by a wavelet decomposition method, in which the set of projections is separated into thumbnail images expressing the whole and the higher frequency details of the projections, respectively. The reconstruction is carried out separately on the thumbnail images before making a combination. Certain properties of this decomposition, notably in the Fourier frequency domain, provide substantial reduction of the amount of calculations.
摘要:
A correct inversion formula of projections of tomography is proposed by supposing improved deformation of the object (E), that is, comprising translations, rotations and homotheties comparable to uniform dilations. Generalisations to other deformation situations of the object in question and other radiations are possible.