Introduction: Wedge filters are used in radiotherapy to modify photon beam and improve dose uniformity in the target volume. Determination of wedge dose distribution is important to improve treatment planning accuracy. The utilization of treatment planning software to obtain dose distribution is not always available. In this work an analytical model has been developed to calcu...

A universal wedge filter of 15W × 20 cm(2) and 60° nominal wedge angle is designed and placed between the collimating jaws and penumbra trimmers inside the treatment head. A pneumatically driven actuating mechanism toggles the wedge between the wedge IN position and wedge OUT position. The effective wedge angles were determined using an analytical formula. An accumulated wedge profile at a dept...

It is well known that, when the vertex angle of a straight wedge is less than the critical angle, there exists a shock-front emanating from the wedge vertex so that the constant states on both sides of the shock-front are supersonic. Since the shock-front at the vertex is usually strong, especially when the vertex angle of the wedge is large, then such a global flow is physically required to be...

Three-dimensional L4-L5 finite element (FE) models of three disc heights (9.5mm, 11.5mm, and 13.5mm) and three disc wedge angles (5o, 8 o, and 10 o) were developed to investigate their effect on L4-L5 lumbar motion segment under pure axial compressive loading. The FE predictions indicated that the axial disc displacement and the posterior disc bulge increased greatly with an increase in the ave...

A new optical design for an autocorrelator using a double wedge is proposed and experimentally demonstrated. It consists of two wedges placed in a mirror-image configuration. Instead of splitting a beam by 90 degree angle as done in a conventional autocorrelator based on Michelson interferometer, the wedge splits the beam by 180 degrees. The angle of incidence is nearly normal to all the wedge ...

Two-directional differential phase contrast images were measured using an x-ray microbeam and a double wedge absorber. The wedge absorber converts the displacement of an x-ray beam that is refracted by an object into change of x-ray intensity. The double wedge absorber made it possible to detect values of two-directional refraction angle with microrad sensitivity simultaneously. By Fourier inte...

A new method of generating wedge-shaped dose distributions through dynamic multileaf collimator dose delivery rather than computer-controlled jaw motion is presented. The method starts with the calculation of a wedge-shaped beam profile for the desired wedge angle. The resultant wedge beam profile is then passed to the intensity-modulated radiation therapy (IMRT) leaf sequence generation algori...

For a supersonic Euler flow past a straight wedge whose vertex angle is less than the extreme angle, there exists a shock-front emanating from the wedge vertex, and the shock-front is usually strong especially when the vertex angle of the wedge is large. In this paper, we establish the L wellposedness for two-dimensional steady supersonic Euler flows past a Lipschitz wedge whose boundary slope ...

BACKGROUND Although a change in tibial slope may occur during a medial opening wedge osteotomy, calculations have not been defined to address this problem. The authors investigated geometric factors important to correct axial alignment and tibial slope during osteotomy. PURPOSE To calculate, through 3-dimensional analysis of the proximal tibia, how the angle of the opening wedge along the ant...

A theoretical model, along with experimental verification, is developed to describe the generation, propagation and reception of a Rayleigh wave using angle beam wedge transducers. The Rayleigh wave generation process using an angle beam wedge transducer is analyzed, and the actual Rayleigh wave sound source distributions are evaluated numerically. Based on the reciprocity theorem and consideri...