Collimating apparatus capable of performing segmented and stepless adjustment on slits

Abstract

The invention relates to the technical field of CT equipment manufacturing, in particular to a collimating apparatus capable of performing segmented and stepless adjustment on slits. The collimating apparatus comprises a base, wherein two supporting seats are in sliding connection to the base; a plurality of shutters are arranged on each supporting seat; a slit is formed between every two shutterson the two supporting seats; a connecting plate is connected to each shutter; a servomotor is connected to each connecting plate; fixing plates are connected to two sides of the base; springs are connected between each connecting plate and the corresponding fixing plate; an eccentric shaft which is rotatably connected with the base is arranged on one side away from the slit, of each supporting seat; an eccentric wheel is arranged on each eccentric shaft; and a driving part is arranged on the base. The collimating apparatus disclosed by the invention has the advantages that the two eccentric shafts are driven by two motors to rotate to drive the shutters to perform stepless adjustment of slit dimension; each servomotor which is tightly attached to the corresponding eccentric wheel is arranged on the corresponding shutter; when the thicknesses of a scanning layer are not the same, the angular position between shutter slit curves on one side can be in segmented and stepless adjustment, so that the curvature of a slit curve is adjustable, ineffective slit regions are greatly reduced, and requirements for different layer thicknesses are met.

Description

technical field [0001] The invention relates to the technical field of CT equipment manufacturing, in particular to a slit segmented stepless adjustable collimator. Background technique [0002] CT (Computed Tomography), that is, electronic computer tomography, is the product of the combination of modern computer control technology and X-ray image inspection technology, which is an indispensable equipment in medical diagnosis. Such as figure 1 As shown, the X-rays emitted by the tube of the CT system pass through the human body after shielding excess rays through the collimator and are absorbed by the detector. The detector converts the absorbed X-rays into electrical signals to generate images. [0003] When scanning, in order to improve the dose utilization rate of X-rays, different collimator slits are required according to different scanning layer thicknesses, and the slits of different layer thicknesses are in the XY plane (XY plane can refer to figure 1 ), the curvat...

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Problems solved by technology

[0004] In the prior art, a motor is often used to drive a ram with multiple fixed slits to translate. When the thickness of the scanning layer is different, the redundant rays are limited by switching different slits. However, such a design has a fixed slit. Can not be adjusted steplessly, the defect of poor selectability

[0005] In the prior art, there are also two motors used to drive two independently movable sheet gates to adjust the slit size steplessly, but such a solution has a fixed curvature of the slit curve, and when the thickness of the scanning layer is different, It will result in invalid part of the slit area (the slit curve of the sheet gate is integrated, such as image 3 and 4 as shown, image 3 Taking the curve of the large slit as the design basis, when the slit is reduced, the invalid slit area is larger, Figure 4 Taking the curve of the small slit as the design basis, when the slit increases, the ineffective slit area is still large), resulting in a low dosage utilization

[0006] In the prior art, two motors are also used to drive two arc-shaped gates that can move independently, and the size of the slit is adjusted steplessly. Although this solution does not have the problem of invalid slit area, it also has the following defects: the arc-shaped gate The processing cost is high and the space occupied is large

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