CN116027564A - Stepless slit collimator and CT scanning equipment - Google Patents

Abstract

The application discloses a stepless slit collimator and CT scanning equipment, including: an optical plane, on which a guide rail is arranged along the Z-axis direction, and the middle part of the guide rail is disconnected to form two coaxial guide rail segments; a parallelogram Components, the parallelogram component includes two rotating opposite sides and two parallel opposite sides, the middle part of the rotating opposite sides is hinged with the optical plane through a pin shaft, the two ends of the parallel opposite sides are respectively hinged with the corresponding rotating opposite sides, and the upper edge of the parallel opposite sides is X There is a chute in the axial direction; the blades are arranged as two parallel ones distributed along the Z-axis direction, and the two blades are respectively connected to two parallel opposite sides. The blades are provided with guide rail sliders and at least two positioning blocks, two The guide rail sliders of the blades are respectively slidably connected to the two guide rail segments, and the positioning blocks of the two blades are respectively slidably connected to two parallel opposite chutes. The application achieves the technical effects of improving the accuracy of the slotting control, reducing the error generated in the control process, and greatly reducing the material cost of the equipment.

Description

Stepless slit collimator and CT scanning equipment

technical field

The present application relates to the technical field of CT equipment, in particular, to a stepless slotted collimator and CT scanning equipment.

Background technique

The CT system is a scanning device that uses rotating exposure and data acquisition. The core principle of the CT system is to collect data from the relatively precise geometry of the rotating system and the scanned object (human body), and then reconstruct the collected data to obtain an image. . During each scanning process, the CT system will adjust the Z-direction coverage width of the system's exposure ray field according to the needs of data acquisition to minimize the patient's radiation dose. The component that adjusts the Z-direction coverage of the system rays is called a collimator.

In the XOY plane, the detector is a curved surface centered on the focal point. The industry usually uses two collimator shapes to adjust the light field coverage. One shape is a flat plate collimator parallel to the X-axis direction, and the other One is an arc collimator centered on the focal point and concentric with the detector plane. Since the projection ratio in the X (or detector fan angle) direction is constant, the increment of the aperture width of the collimator in the X (or detector fan angle) direction has the same step amount of the light field width on the detector surface, and the arc collimation Compared with the flat collimator, the collimator has a more precise control effect.

The stepless slit collimation is a collimation structure in which the relative position of the two blades is flexibly controlled. This method can flexibly adjust the slit width according to the actual situation; the fixed slit structure is a slit with various preset widths hollowed out on a shielding plate. And when in use, the overall adjustment device is used to adjust the slot width. This method cannot flexibly adjust the slot width according to the actual situation. All position accuracy and slot width accuracy can only rely on mechanical processing; therefore, stepless slot alignment is more accurate. It is conducive to the guarantee of design accuracy and the scalability of slit adjustment.

Most of the arc-shaped stepless slit collimator design schemes in the industry adopt the following methods: 1. Install two arc-shaped collimation blades on a common parallel guide rail; 2. Use two motors, encoders and lead screws to align Two blades for motion control. These common schemes at present have the shortcoming and the problem of following aspects:

Stress problem of parallel guide rails: the design of parallel guide rails, installation errors and other problems lead to stress problems of the drive, which will reduce the life of the motor and affect the position of the control and the accuracy of the slit width;

Relative error of dual motor encoders and dual lead screws: The motor encoder and lead screw pitch are factors that affect the position control accuracy. The system requires that the motion of the two collimation blades be symmetrical, and the two blades use different motor encoders And different lead screws will cause the error of the symmetry of the two blades relative to the center of the light plane;

Cost issues: Motors, encoders, leadscrews, and guide rails are all very important cost-related components. If fewer related components can be used, the cost of the equipment can be greatly reduced.

Contents of the invention

The main purpose of this application is to provide a stepless slotted collimator and CT scanning equipment, to solve the problem of extra gaps in the adjustment process of the stepless slotted collimator in the related art due to design errors and installation errors of parallel guide rails. The stress generated will reduce the life of the motor and affect the control position and slit width accuracy, and the use of dual drive equipment will cause the error of the symmetry of the two blades relative to the center of the light plane, and the problem of high cost.

In order to achieve the above purpose, the application provides a stepless slotted collimator, which includes:

A light plane, a guide rail is arranged along the Z-axis direction on the light plane, the middle part of the guide rail is disconnected to form two coaxial guide rail segments, and the disconnection distance between the two guide rail segments is greater than or equal to the coverage of the rays ;

The parallelogram member is arranged on the optical plane, and the parallelogram member includes two rotating opposite sides and two parallel opposite sides, the middle part of the rotating opposite sides is hinged with the optical plane through a pin shaft, and the parallel opposite sides The two ends of each are respectively hinged to the corresponding rotating opposite sides, and a chute is provided along the X-axis direction on the parallel opposite sides;

The blades are arranged as two distributed along the Z-axis direction and parallel, and the two blades are respectively connected to the two parallel opposite sides, and the blades are provided with guide rail sliders and at least two positioning blocks, and the two blades The slide blocks of the guide rail are respectively slidably connected with the two guide rail segments, and the positioning blocks of the two blades are respectively slidably connected with the two slide grooves on the parallel opposite sides.

Further, it also includes a driving assembly, the driving assembly is connected with the pin shaft of one of the rotating opposite sides, and the rotating opposite side is driven to rotate around the axis of the pin shaft through the driving assembly.

Further, the driving assembly includes a driving motor and a first encoder, the driving motor is in transmission connection with the first encoder, and the output end of the first encoder is in transmission connection with one of the pin shafts on the opposite side of rotation .

Further, the driving assembly further includes a transmission shaft, and the two ends of the transmission shaft are respectively connected to the driving motor and the first encoder via a shaft coupling.

Further, a second encoder is further included, and the second encoder is connected with the pin shaft of the other opposite side of rotation, and is used to obtain the rotation data of the opposite side of rotation.

Further, the pin shaft is hinged on the optical plane, and the pin shafts of the two opposite rotating sides are symmetrical along the center line of the optical plane;

A fulcrum pin hole is opened in the middle of the opposite side of rotation, and the pin shaft passes through the hole of the fulcrum pin and is fixedly connected with the opposite side of rotation, so that the opposite side of rotation can rotate around the axis of the positioning pin rotate.

Further, the blades are set in a flat or arc shape.

Further, at least two guide rail sliders are arranged and distributed along the Z-axis direction, and the two guide rail sliders are slidably connected to the corresponding guide rail segments.

Further, the positioning block is set to be cylindrical or rectangular.

According to another aspect of the present application, a CT scanning device is provided, including the above-mentioned stepless slotted collimator.

In the embodiment of the present application, by setting the light plane, a guide rail is arranged along the Z-axis direction on the light plane, and the middle part of the guide rail is disconnected to form two coaxial guide rail segments, and the disconnection distance between the two guide rail segments is greater than or equal to the ray The coverage range; the parallelogram member is set on the light plane, the parallelogram member includes two rotating opposite sides and two parallel opposite sides, the middle part of the rotating opposite sides is hinged with the optical plane through a pin shaft, and the two ends of the parallel opposite sides are respectively connected to the corresponding The rotating opposite sides are hinged, and a chute is provided along the X-axis direction on the parallel opposite sides; two blades are arranged in parallel along the Z-axis direction, and the two blades are respectively connected to the two parallel opposite sides, and the blades are provided with The guide rail slider and at least two positioning blocks, the guide rail sliders of the two blades are respectively slidably connected with the two guide rail segments, and the positioning blocks of the two blades are respectively slidably connected with the two parallel opposite sides of the chute, which can be achieved only by A single drive device drives one rotating opposite side to rotate, using the characteristics of a parallelogram to keep the two parallel opposite sides parallel and close to or away from each other, while making the other rotating opposite side rotate synchronously. During the movement, under the action of the guide rail section and the chute, the two blades will be forced to keep parallel and approach or move away from each other along the Z-axis direction to adjust the distance between the two blades, thus realizing the improvement of the precision of slot control The technical effect of reducing the error generated in the control process and greatly reducing the material cost of the equipment, and then solving the problem in the adjustment process caused by the design error and installation error of the parallel guide rail in the stepless slotted collimator in the related technology Additional stress will reduce the life of the motor and affect the control position and slit width accuracy, and the use of dual drive equipment will cause errors in the symmetry of the two blades relative to the center of the light plane, and the problem of high cost.

Description of drawings

The accompanying drawings, which constitute a part of this application, are included to provide a further understanding of the application and make other features, objects and advantages of the application apparent. The drawings and descriptions of the schematic embodiments of the application are used to explain the application, and do not constitute an improper limitation to the application. In the attached picture:

FIG. 1 is a schematic diagram of an application according to an embodiment of the present application;

Fig. 2 is a schematic structural diagram according to an embodiment of the present application;

Fig. 3 is a schematic diagram of the structure after rotating the side-to-side rotation according to the embodiment of the present application;

FIG. 4 is a schematic diagram of an optical plane according to an embodiment of the present application;

Fig. 5 is a schematic diagram of a parallelogram member according to an embodiment of the present application;

Fig. 6 is a schematic diagram of a blade according to an embodiment of the present application;

Among them, 1 light plane, 2 pin shaft, 3 blades, 4 rotating opposite sides, 6 parallel opposite sides, 7 guide rail slider, 8 guide rail segment, 9 chute, 10 positioning block, 11 collimator.

Detailed ways

In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiment of the application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiment of the application. Obviously, the described embodiment is only It is an embodiment of a part of the application, but not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the scope of protection of this application.

It should be noted that the terms "first" and "second" in the description and claims of the present application and the above drawings are used to distinguish similar objects, but not necessarily used to describe a specific sequence or sequence. It should be understood that the data so used may be interchanged under appropriate circumstances for the embodiments of the application described herein.

In the present application, the orientation or positional relationship indicated by the terms "upper", "lower", "inner", etc. is based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit that the indicated devices, elements or components must have a specific orientation, or be constructed and operated in a specific orientation.

Moreover, some of the above terms may be used to indicate other meanings besides orientation or positional relationship, for example, the term "upper" may also be used to indicate a certain attachment relationship or connection relationship in some cases. Those skilled in the art can understand the specific meanings of these terms in this application according to specific situations.

Furthermore, the terms "disposed", "provided", "connected", "fixed", etc. are to be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediary, or two devices, components or Internal connectivity between components. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application according to specific situations.

In addition, the term "plurality" shall mean two or more than two.

It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and embodiments.

Most of the arc-shaped stepless slit collimator design schemes in the industry adopt the following methods: 1. Install two arc-shaped collimation blades on a common parallel guide rail; 2. Use two motors, encoders and lead screws to align Two blades for motion control. These common schemes at present have the shortcoming and the problem of following aspects:

Stress problem of parallel guide rails: the design of parallel guide rails, installation errors and other problems lead to stress problems of the drive, which will reduce the life of the motor and affect the position of the control and the accuracy of the slit width;

Relative error of dual motor encoders and dual lead screws: The motor encoder and lead screw pitch are factors that affect the position control accuracy. The system requires that the motion of the two collimation blades be symmetrical, and the two blades use different motor encoders And different lead screws will cause the error of the symmetry of the two blades relative to the center of the light plane;

Cost issues: Motors, encoders, leadscrews, and guide rails are all very important cost-related components. If fewer related components can be used, the cost of the equipment can be greatly reduced.

To this end, as shown in Figures 1 to 3, the embodiment of the present application provides a stepless slotted collimator 11, the stepless slotted collimator includes:

Optical plane 1, a guide rail is arranged along the Z-axis direction on the optical plane 1, the middle part of the guide rail is disconnected to form two coaxial guide rail segments 8, and the disconnection distance between the two guide rail segments 8 is greater than or equal to the coverage of the rays;

The parallelogram member is arranged on the optical plane 1. The parallelogram member includes two rotating opposite sides 4 and two parallel opposite sides 6. The middle part of the rotating opposite sides 4 is hinged with the optical plane 1 through the pin shaft 2, and the two ends of the parallel opposite sides 6 are They are respectively hinged with the corresponding rotating opposite sides 4, and a chute 9 is provided along the X-axis direction on the parallel opposite sides 6;

The blades 3 are arranged as two parallel ones distributed along the Z-axis direction. The two blades 3 are respectively connected to two parallel opposite sides 6. The blades 3 are provided with guide rail sliders 7 and at least two positioning blocks 10. The two blades The guide rail slider 7 of 3 is respectively slidably connected with the two guide rail segments 8, and the positioning blocks 10 of the two blades 3 are respectively slidably connected with the chute 9 of the two parallel opposite sides 6.

In this embodiment, the collimator 11 is mainly composed of three parts: a light plane 1 , a parallelogram member and blades 3 . As shown in FIG. 4 , the light plane 1 can be arranged as a square sheet structure, which has good light transmission, and rays can be projected through the light plane 1 . A guide rail is arranged on the side of the light plane 1 facing the projection surface. The direction of the guide rail is the direction of the Z axis. Pitch. Since the ray needs to pass through the light plane 1, in order to avoid the guide rail from blocking the ray, the complete guide rail is divided into upper and lower parts in this embodiment, which are respectively the guide rail section 8 located at the upper part of the light plane 1 and the guide rail section 8 located at the lower part of the light plane 1. Rail section 8. Since the guide rails are arranged along the Z-axis direction, coaxiality can be maintained between the two disconnected guide rail segments 8 , and there is no offset in both the Y-axis direction and the X-axis direction. The distance between the two guide rail sections 8 needs to be greater than or equal to the coverage of the rays, preferably larger than the coverage of the rays, so that the guide rail sections 8 will not block the rays during the entire adjustment process of the slit.

As shown in Figure 4, in addition to the guide rail section 8, there are two pin shafts 2 arranged on the light plane 1, the two pin shafts 2 are distributed along the X-axis direction, and the two pin shafts 2 are symmetrical along the center line of the light plane 1 at the same time , the pin shaft 2 can be hinged with the optical plane 1, so that the pin shaft 2 can be driven to rotate on the optical plane 1. Specifically, the pin shaft 2 can be hinged to the optical plane 1 through a bearing or a bushing.

The parallelogram member is a relatively core part in this embodiment. Due to the structural characteristics of the parallelogram, when the four sides are hinged sequentially, the rotation of any side will drive the opposite side to rotate synchronously, while the adjacent side will maintain a parallel state and translate. When the parallelogram changes from a rectangle to a form in which one pair of sides is inclined, the distance between the other pair of sides decreases, whereas the distance between the other pair of sides increases. For this reason, this embodiment utilizes the characteristics of a parallelogram so that only the opposite side on one side needs to be driven to rotate to control the distance between adjacent sides while maintaining parallelism.

Specifically, as shown in Fig. 2, Fig. 3 and Fig. 5, in this embodiment, the parallelogram member is composed of two opposite sides 4 and two opposite sides 6, and the opposite sides 4 are distributed along the X-axis direction and They are respectively fixedly connected to the pin shafts 2 on both sides of the optical plane 1 , and the parallel opposite sides 6 are distributed along the Z-axis direction and hinged to the adjacent rotating opposite sides 4 . When in use, a driving assembly needs to be installed, and the driving assembly is connected to the pin shaft 2 of one of the rotating opposite sides 4 through transmission, and the rotating opposite side 4 is driven to rotate around the axis of the pin shaft 2 through the driving assembly.

In this embodiment, only one drive assembly is needed to drive one of the rotating opposite sides 4 to rotate, so as to control the two parallel opposite sides 6 to keep parallel and translate. During the transformation process of a simple parallelogram, the translation direction of the parallel opposite side 6 is substantially oblique, and its translation direction can be decomposed into the X-axis direction and the Z-axis direction. And corresponding to the translation process of the blade 3, it is necessary to make the blade 3 only translate in the Z-axis direction but not in the X-axis direction, so the blade 3 cannot be directly and simply connected to the parallel opposite side 6, and the additional structure will be Release the driving force in the X-axis direction generated by the parallel opposite sides 6 during the translation process.

For this reason, in the present embodiment, a chute 9 is provided on the parallel opposite sides 6, and the opening direction of the chute 9 is the X-axis direction. As shown in Figure 6, each blade 3 is arranged with a At least two positioning blocks 10. The purpose of setting two positioning blocks 10 is to maintain the parallelism of the two blades 3. The two positioning blocks 10 are located in the same chute 9 and can slide linearly along the chute 9. At the same time, the blade 3 is also arranged with a guide rail on this side Block 7. The guide rail slider 7 of the upper blade 3 is slidably connected with the upper guide rail section 8 , and the slide rail slider of the lower blade 3 is slidably connected with the lower guide rail section 8 . During the translation of the two parallel opposite sides 6, the positioning block 10 cooperates with the chute 9 to release the driving force in the X-axis direction, and the guide rail slider 7 cooperates with the guide rail segment 8 so that the two blades 3 can be opposite or opposite to each other. linear motion. Under the joint cooperation of the positioning block 10, the chute 9, the guide rail slider 7 and the guide rail segment 8, during the translation process of the two parallel opposite sides 6, the two blades 3 can be kept parallel while facing each other in the Z-axis direction. Or opposite linear motion.

The X-axis involved in this embodiment is the coordinate axis located on the horizontal plane and perpendicular to the outgoing direction of the ray in the three-dimensional coordinate system, the Z-axis is the vertical coordinate axis perpendicular to the X-axis, and the Y-axis is located on the horizontal plane and aligned with the X-axis. axis perpendicular to the coordinate axis.

In this embodiment, through the stepless slit collimator 11, only a single driving device can drive a rotating opposite side 4 to rotate, and the characteristics of a parallelogram are used to keep the two parallel opposite sides 6 in a parallel state and close to each other. Or away from it, and at the same time make the other rotating opposite side 4 rotate synchronously, during the movement of the two parallel opposite sides 6, under the action of the guide rail segment 8 and the chute 9, the two blades 3 will be forced to remain parallel and along the Z-axis direction The purpose of adjusting the distance between the two blades 3 is to move closer or farther away from each other, thereby achieving the technical effect of improving the accuracy of the slot control, reducing the error generated during the control process, and greatly reducing the material cost of the equipment, thereby solving the problem of In the related art, the stepless slit collimator 11 has additional stress during the adjustment process due to the design error and installation error of the parallel guide rails, which will reduce the life of the motor and affect the control position and slit width accuracy. The double driving device will cause the error of the symmetry of the two blades 3 relative to the center of the light plane 1, and the problem of high cost.

There is a certain mathematical relationship between the amount of rotation of the opposite side of rotation 4 and the amount of translation of the blade 3 , so by controlling the amount of rotation of the opposite side of rotation 4 , the translation amount of the blade 3 can be controlled, and then the slot value can be controlled. In order to control the amount of rotation of the opposite side of rotation 4, the drive assembly in this embodiment includes a drive motor and a first encoder, the drive motor is connected to the first encoder, and the output end of the first encoder is connected to one of the opposite sides of rotation. 4 pin shaft 2 transmission connection. The rotation amount of the drive motor can be obtained in real time through the first encoder, and the rotation amount of the opposite side 4 can be determined based on the rotation amount of the drive motor.

In order to facilitate rotation, the drive assembly in this embodiment further includes a transmission shaft, and the two ends of the transmission shaft are respectively connected to the drive motor and the first encoder via a shaft coupling.

Since the rotating opposite side 4 not connected with the driving motor is passively rotating, the rotation angle of the rotating opposite side 4 should be exactly the same as that of the other rotating opposite side 4 in an ideal state. Therefore, in order to facilitate the monitoring of the rotation process, this embodiment also includes a second encoder, which is in transmission connection with the pin shaft 2 of another opposite rotating side 4 for obtaining the rotation data of the opposite rotating side 4 .

Further, the pin shaft 2 is hinged on the optical plane 1, and the pin shafts 2 of the two rotating opposite sides 4 are symmetrical along the center line of the optical plane 1; in order to facilitate the connection between the rotating opposite sides 4 and the pin shaft 2, in this embodiment, The middle part of the side 4 is provided with a fulcrum pin hole, and the pin shaft 2 passes through the fulcrum pin hole and is fixedly connected with the rotating opposite side 4, so that the rotating opposite side 4 can rotate around the axis of the rotating positioning pin.

Further, the blades 3 are set in a flat or arc shape. Because the projection ratio on the X-axis (or detector fan angle) direction is constant, the aperture width increment of the collimator 11 is consistent with the step amount of the light field width on the detector surface in the X-axis (or detector fan angle) direction, and the arc Compared with the flat collimator 11, the shape collimator 11 has a more precise control effect. Therefore, the blade 3 in this embodiment is arc-shaped.

In order to improve the stability of the movement of the blade 3 for the flap, at least two guide rail sliders 7 are provided in this embodiment and distributed along the Z-axis direction, and the two guide rail sliders 7 are slidably connected to the corresponding guide rail segments 8 . The positioning block 10 is configured as a cylinder or a rectangle.

According to another aspect of the present application, a CT scanning device is provided, including the above-mentioned stepless slotted collimator.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application. For those skilled in the art, there may be various modifications and changes in the present application. Within the spirit and principles of this application, any modifications, equivalent replacements, improvements, etc., shall be included within the protection scope of this application.

Claims (10)

1. A stepless slotted collimator, characterized in that, comprising: A light plane, a guide rail is arranged along the Z-axis direction on the light plane, the middle part of the guide rail is disconnected to form two coaxial guide rail segments, and the disconnection distance between the two guide rail segments is greater than or equal to the coverage of the rays ; The parallelogram member is arranged on the optical plane, and the parallelogram member includes two rotating opposite sides and two parallel opposite sides, the middle part of the rotating opposite sides is hinged with the optical plane through a pin shaft, and the parallel opposite sides The two ends of each are respectively hinged to the corresponding rotating opposite sides, and a chute is provided along the X-axis direction on the parallel opposite sides; The blades are arranged as two distributed along the Z-axis direction and parallel, and the two blades are respectively connected to the two parallel opposite sides, and the blades are provided with guide rail sliders and at least two positioning blocks, and the two blades The slide blocks of the guide rail are respectively slidably connected with the two guide rail segments, and the positioning blocks of the two blades are respectively slidably connected with the two slide grooves on the parallel opposite sides. 2. The stepless slotted collimator according to claim 1, characterized in that: said drive assembly is also included, said drive assembly is connected to one of the pin shafts on the opposite side of the rotation, driven by the drive assembly The rotating opposite side rotates around the axis of the pin shaft. 3. The stepless slit collimator according to claim 2, characterized in that: the drive assembly includes a drive motor and a first encoder, the drive motor is in transmission connection with the first encoder, the The output end of the first encoder is in drive connection with one of the pin shafts on opposite sides of the rotation. 4. The stepless slotted collimator according to claim 3, characterized in that: the drive assembly further comprises a transmission shaft, the two ends of the transmission shaft are respectively connected to the drive motor and the first encoder Drive connection through coupling. 5. The stepless slotted collimator according to claim 4, characterized in that: it also includes a second encoder, the second encoder is connected with the pin shaft of another said rotating opposite side, for Get the rotation data of the opposite side of the rotation. 6. The stepless slotted collimator according to claim 1, characterized in that: the pin shaft is hinged on the optical plane, and the pin shafts of the two opposite rotating sides are along the centerline of the optical plane symmetry; A fulcrum pin hole is opened in the middle of the opposite side of rotation, and the pin shaft passes through the hole of the fulcrum pin and is fixedly connected with the opposite side of rotation, so that the opposite side of rotation can rotate around the axis of the positioning pin rotate. 7. The stepless slotted collimator according to claim 1, characterized in that: the blades are arranged in a flat or arc shape. 8. The stepless slotted collimator according to claim 1, characterized in that: the guide rail sliders are arranged at least two and distributed along the Z-axis direction, and the two guide rail sliders are connected to the corresponding The above-mentioned guide rail sections are slidingly connected. 9. The stepless slotted collimator according to claim 1, characterized in that: the positioning block is configured as a cylinder or a rectangle. 10. A CT scanning device, characterized by comprising the stepless slotted collimator according to any one of claims 1 to 9.

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