CN111759343A - Position calibration method of collimator in three-in-one equipment upper head side shooting mode - Google Patents

Position calibration method of collimator in three-in-one equipment upper head side shooting mode Download PDF

Info

Publication number
CN111759343A
CN111759343A CN202010711506.9A CN202010711506A CN111759343A CN 111759343 A CN111759343 A CN 111759343A CN 202010711506 A CN202010711506 A CN 202010711506A CN 111759343 A CN111759343 A CN 111759343A
Authority
CN
China
Prior art keywords
collimator
image
detector
calibration
initial position
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202010711506.9A
Other languages
Chinese (zh)
Inventor
张丽灵
陈毅
袁佳
张静波
施佳敏
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shanghai Youjiji Medical Imaging Equipment Co ltd
Original Assignee
Shanghai Youjiji Medical Imaging Equipment Co ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shanghai Youjiji Medical Imaging Equipment Co ltd filed Critical Shanghai Youjiji Medical Imaging Equipment Co ltd
Priority to CN202010711506.9A priority Critical patent/CN111759343A/en
Publication of CN111759343A publication Critical patent/CN111759343A/en
Pending legal-status Critical Current

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/06—Diaphragms
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/50—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment specially adapted for specific body parts; specially adapted for specific clinical applications
    • A61B6/51—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment specially adapted for specific body parts; specially adapted for specific clinical applications for dentistry
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B6/00—Apparatus or devices for radiation diagnosis; Apparatus or devices for radiation diagnosis combined with radiation therapy equipment
    • A61B6/58—Testing, adjusting or calibrating thereof
    • A61B6/582—Calibration
    • A61B6/585—Calibration of detector units
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
    • G06T7/20—Analysis of motion
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T7/00—Image analysis
    • G06T7/70—Determining position or orientation of objects or cameras

Landscapes

  • Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Medical Informatics (AREA)
  • Physics & Mathematics (AREA)
  • Heart & Thoracic Surgery (AREA)
  • General Health & Medical Sciences (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Optics & Photonics (AREA)
  • Pathology (AREA)
  • Radiology & Medical Imaging (AREA)
  • Biomedical Technology (AREA)
  • Biophysics (AREA)
  • Molecular Biology (AREA)
  • Surgery (AREA)
  • Animal Behavior & Ethology (AREA)
  • High Energy & Nuclear Physics (AREA)
  • Public Health (AREA)
  • Veterinary Medicine (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Multimedia (AREA)
  • Dentistry (AREA)
  • Oral & Maxillofacial Surgery (AREA)
  • Apparatus For Radiation Diagnosis (AREA)

Abstract

The invention discloses a position calibration method of a collimator under a head-side shooting mode of three-in-one equipment, and relates to the technical field of head-side imaging in dental three-in-one. The invention designs a calibration system which is not observed by human eyes, enables a computer to identify images and is mechanically and automatically adjusted after a result is obtained by an algorithm by combining the images and the algorithm. The invention realizes time and labor saving, simultaneously realizes the precision which can not be achieved by manpower, greatly reduces the operation difficulty, improves the processing efficiency, calculates deviation data by an algorithm, then transmits the deviation data to a lower computer, and automatically adjusts the machine, and the process can be carried out at most two or three times to obtain an ideal result, thereby reducing the time cost and having high efficiency. The operation is simple, the customer can carry out the operation by himself, and the waiting time is reduced. The cooperation of the additional tool is reduced, the material is saved, and the cost of adding and storing the additional component by the client is reduced.

Description

Position calibration method of collimator in three-in-one equipment upper head side shooting mode
Technical Field
The invention belongs to the technical field of lateral skull imaging in three-in-one dentistry, and particularly relates to a position calibration method of a collimator in an upper lateral head shooting mode of three-in-one equipment.
Background
An X-ray cranial imaging technique is an imaging technique in which a patient's head is radiographically projected with X-rays to obtain a lateral perspective view of the patient's head. When shooting, the X-ray narrow beam is used, the absorbed dose of a human body is reduced, two collimators are arranged between the skull and the ray source, one collimator is arranged in front of the ray source and can prevent redundant rays from emitting, the other collimator is arranged in front of the skull and can limit an imaging area, the phenomenon that a divergent part images on a detector in the moving process of rays is also reduced, and the image definition is reduced. If the two collimators have deviation in installation position, the imaged image is defective and even cannot be imaged all the time, so that calibration is needed.
Japanese patent application (JP2018509950A) discloses a manual calibration method, which subjectively judges the inclination of an image according to a shot image, manually adjusts parts on a machine to perform calibration, has high error possibility, and relies on manual judgment to perform calibration, which is time-consuming, labor-consuming and low in precision; whether the installation and debugging are carried out in the factory or after-sale maintenance is carried out, the related personnel are required to have rich experience and image analysis capability, and the installation and after-sale cost is increased. The US patent of invention (US20180322665a1) discloses a dynamic image data processing, which does not calibrate the imaging position of the radiation source on the detector through the collimator in advance, but detects the imaging position during shooting, makes the imaging in the center of the detector by means of cropping, and needs to transmit the cropping information to the reconstruction module; however, the position of the machine is not adjusted, and errors of the machine are accumulated after long-time use. The Chinese invention patent (CN109431534A) discloses a self-calibration method of a ray collimator, which is characterized in that X rays cover the whole detector during calibration, and when the deviation of the position is not guaranteed, a boundary appears on the detector, so that the calculation of a deviation value is wrong; after the position deviation is corrected, the deviation on the speed is not corrected, and then the speed deviation in the subsequent movement can cause the deviation on the position; and only provides a calibration method when there is one collimator.
Mechanical automation has the advantage of being able to rely on the cooperation between the computer and the machine, not requiring an engineer to operate on the machine, and requiring only a small number of clicks on the computer interface to complete the calibration procedure. With the development of computer vision, the obtained images can be accurately analyzed to obtain mechanical errors, and deviation values can be accurately calculated. At present, the chip has stronger and higher processing capacity and higher precision, and the accurate control of machinery can be realized by means of input parameters, so that the machine becomes more and more intelligent. The two are combined, so that the time cost and the labor cost can be effectively reduced, the working efficiency is improved, and the accuracy is also improved. The position calibration method of the collimator in the head-side shooting mode of the three-in-one device is provided, and linkage of two collimators is calibrated.
Disclosure of Invention
The invention aims to provide a position calibration method of a collimator in a head-side shooting mode of three-in-one equipment, which designs a calibration system which does not need to be observed by human eyes, enables a computer to identify images, obtains results by means of an algorithm and then adjusts mechanically and automatically by combining the images and the algorithm; the precision that manpower can not reach is realized while realizing labour saving and time saving, and the operation degree of difficulty greatly reduced has improved treatment effeciency.
In order to solve the technical problems, the invention is realized by the following technical scheme:
the invention relates to a position calibration method of a collimator under a head-side shooting mode of three-in-one equipment, which comprises the following steps:
step S001: initializing a calibration module, shooting an image for pre-calibration, if the image is imaged on the detector D, performing step S002, and otherwise prompting to perform mechanical adjustment;
step S002: the first collimator C1 and the detector D move from the initial position L1 to the end position L2 along the direction of the lateral film shooting movement, and the images are received after exposure in the moving process;
step S003: analyzing the image: if the image is completely black or the state cannot be analyzed, an error is reported, and an image condition code is given; otherwise, the step of analyzing the calibration data of the first collimator C1 is performed in the following specific manner:
step S031: acquiring a movement initial position S1 and a movement speed V1 of a first collimator C1 by taking the detector D as a reference;
step S032: calculating and recording calibration data of the first collimator C1, compensating the motion state of the first collimator C1, and moving the first collimator C1 and the detector D back to the initial position L1 of the lateral slice shooting motion in the step S002;
step S004: the first collimator C1 moves from the initial position L1 to the end position L2 along the direction of the side film shooting movement at the calibrated movement speed, displacement and exposure during the movement to receive images;
step S005: analyzing the image, if the calibration data meets the error requirement, completing the calibration of the first collimator C1, and proceeding to step S006; otherwise, repeating the steps S002 to S005;
step S006: the first collimator C1 and the detector D move back to the side film shooting movement initial position L1 in the step S002, the second collimator C2 returns to the initial position L1 preset in the step S011, the first collimator C1 is opened until the imaging width is 10mm, the purpose is to cover the detector width 8mm, an image is shot for pre-calibration, if the image is formed on the detector D, the step S007 is carried out, and if not, mechanical adjustment is prompted;
step S007: the first collimator C1, the second collimator C2 and the detector D simultaneously start to move from the initial position L1 to the end position L2 along the direction of the lateral slice shooting movement, and the images are received by exposure in the moving process;
step S008: analyzing the image: if the image is completely black or the state cannot be analyzed, an error is reported, and an image condition code is given; otherwise, the calibration data analysis step of the second collimator C2 is performed in the following specific analysis manner:
step S081: acquiring a movement initial position S2 and a movement speed V2 of a second collimator C2 by taking the detector D as a reference;
step S082: calculating and recording calibration data of the second collimator C2, and compensating the motion state of the second collimator C2, wherein the first collimator C1, the second collimator C2 and the detector D return to the lateral slice shooting motion initial position L1 in the step S007;
step S009: the second collimator C2 moves from the initial position L1 to the end position L2 along the direction of the lateral film shooting movement with the calibrated movement speed and displacement and the first collimator C1 and the detector D, and the exposure is carried out in the moving process to receive the image;
step S0010: analyzing the image, if the calibration data meets the error requirement, finishing the calibration of the second collimator C2, storing the calibration data, and ending the calibration process; otherwise, steps S007-S0010 are repeated.
Further, the calibration data of the first collimator C1 in step S032 and the calibration data of the second collimator C2 in step S082 each include velocity calibration data and initial position calibration data;
in step S032, the method for calculating the calibration data of the first collimator C1 includes:
taking an image of the part of the image, in which the first collimator C1 moves for a time t, (the time period is selected to ensure that the first collimator C1 is in motion and all images on the detector), and the bright strip exists and the first collimator C1 is in a motion state, calculating the total path of the part of the image, in which the bright strip passes, and calculating the actual moving speed by taking the proportion of the total path of the part of the image, in which the t time passes under normal conditions.
Calculating the speed deviation:
Figure BDA0002596711420000051
Snormal＝(index2-index1)*shift；
Figure BDA0002596711420000052
Figure BDA0002596711420000053
initial position deviation calculation:
t＝(index2-index1)/fps；
Figure BDA0002596711420000054
wherein, VC1Is the initial moving speed, V, of the first collimator C1DIs the speed of movement of the detector D, (V)C1And VDSome tolerance is allowed); colmidFor imaging the position of the center line, t is determined by the number of captured image frames and the number of frames per second fps of the image, SnormalFor a theoretical value of the distance moved over the bright-bar image within time t,
Figure BDA0002596711420000055
is the actual distance that the bright strip moves over the image during time t: (
Figure BDA0002596711420000056
scaleFactor) with a multiple relationship in between), col1For the position of the bright strip of the first frame image in the captured image, col2The position of the bright bar of the last frame image in the intercepted image.
Further, the calculation method of the calibration data of the second collimator C2 in step S082 includes:
step SS 81: detecting the edge in the vertical direction to obtain the column V where the edge is positionedline；
Step SS 82: if only one vertical edge exists, judging whether the edge is a left edge or a right edge;
if it is the right edge, col1＝Vline-w/2；
If it is the left edge, col2＝Vline+w/2；
Step SS 83: the calculation formula of the speed deviation and the initial position deviation of the second collimator C2 is the same as the calculation formula of the speed deviation and the initial position deviation of the first collimator C1;
where w is the normal imaging width.
Further, the specific steps of initializing the calibration module in step S001 are as follows:
step S011: moving the first collimator C1 and the detector D to the initial position L1 of the head-side photographing mode, so as to ensure that the X-rays can be imaged on the detector D at the initial positions of the first collimator C1 and the second collimator C2;
step S012: the first collimator C1 opens a narrow slit to allow a 1mm wide bright stripe on the detector D, and the second collimator C2 moves out of the imaging field of view.
Further, the error requirement is that the collimator centerline position and the detector centerline distance are within ± 0.1 mm.
The invention has the following beneficial effects:
the invention designs a calibration system which is not observed by human eyes, enables a computer to identify images and is mechanically and automatically adjusted after a result is obtained by an algorithm by combining the images and the algorithm; the precision that manpower can not reach is realized while realizing labour saving and time saving, and the operation degree of difficulty greatly reduced has improved treatment effeciency. Except necessary manual interference, the calibration method can realize automatic standard, manual judgment is not needed after the image is shot, deviation data is calculated through an algorithm and then transmitted to a lower computer, corresponding adjustment can be automatically carried out on a machine, an ideal result can be obtained by carrying out the process at most two times, the time cost is reduced, and the efficiency is high; the operation is simple, and the customer can carry out the operation by himself, so that the waiting time is reduced; the cooperation of the additional tool is reduced, the material is saved, and the cost of adding and storing the additional component by the client is reduced.
Of course, it is not necessary for any product in which the invention is practiced to achieve all of the above-described advantages at the same time.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a schematic illustration of an environment in which an embodiment of the invention may be practiced;
FIG. 2 is a flow chart of the principle of the operation of the present invention;
FIG. 3 is a schematic diagram of imaging conditions of a normal condition and a collimator deviation condition in a continuous shooting in an embodiment of the present invention;
FIG. 4 is a diagram illustrating an imaging situation under normal conditions and under a condition of a speed deviation in a single frame image when a first collimator is calibrated according to an embodiment of the present invention;
fig. 5 is a schematic diagram of imaging conditions under normal conditions and under speed deviation conditions in a single-frame image when a second collimator is calibrated according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it is to be understood that the terms "upper", "lower", "middle", "length", "inner", "width", and the like, indicate orientations or positional relationships for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referenced components or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.
Under the head side shooting mode, in order to concentrate the ray irradiation scope, fixed shooting region, two collimators have been installed on machinery, the first collimator mounted position is close to the ray source, the second collimator mounted position is close to the detector, because we use the narrow detector, the formation of image scope is little, in the shooting process, if the initial position and the movement speed of first collimator, second collimator and detector motion are asynchronous, can cause wrong regional formation of image, ray blockage, the condition that can not form of image even takes place. In order to avoid the phenomenon, the coordinated movement conditions of the first collimator, the second collimator and the detector need to be calibrated at intervals, the lateral position calibration takes the detector as a reference, the movement initial position S and the movement speed V of the first collimator and the second collimator are calibrated, and during the calibration, related parameters are calculated mainly by means of image analysis. In the process, the included modules are mainly an image analysis part and a calculation part. The image analysis is mainly to perform binarization and edge detection on the obtained image after the noise of the image is reduced, so as to determine the imaging position of the transmitted X-ray on the detector. The calculation module calculates the position of a frame of image in the sequence in the reconstructed image by using a lateral position reconstruction algorithm, so as to know the distance of the moved pixels. In order to avoid the error of the magnification value, the moving distance of the collimator is not calculated by using a similar triangle, but the ratio of the moving pixel distance under the standard condition and the moving pixel distance under the actual condition is calculated, and the ratio of the speed is calculated, so that the deviation value of the speed is obtained.
After the image analysis module is used for obtaining the imaging center position, the calculation module is used for calculating the path traveled by the collimator when the image is shot, and the path difference is obtained by comparing the path traveled by the collimator with the path traveled by the detector. In a certain time t, the speed difference is obtained by dividing the travel difference by the time, namely the speed deviation value which is obtained by us. And analyzing the imaging position on the shot first frame image, comparing the imaging position with the imaging position of the first frame image under the standard condition to obtain a position difference on the image, comparing the position difference with the pixel path traveled by the time t to obtain the position deviation caused by the movement time of the first frame image under the condition of the initial speed, converting the position deviation into a physical distance, and calculating the initial position deviation.
Example (b):
as shown in fig. 1, in the head-side photographing mode, if it is found that the image is blocked or cannot be imaged, it is difficult to distinguish between the problem of the first collimator C1 and the problem of the second collimator C2, so that the two collimators are calibrated during the calibration process.
A position calibration method of a collimator under a head-side shooting mode of three-in-one equipment is disclosed, wherein a calibration flow is shown in figure 2, and the method specifically comprises the following steps:
step S001: initializing a calibration module, shooting an image for pre-calibration, if the image is imaged on the detector D, performing step S002, otherwise, prompting mechanical adjustment, wherein the specific steps of initializing the calibration module are as follows:
step S011: enabling the first collimator C1 and the detector D to move to an initial position L1 of a head-side shooting mode, ensuring that X-rays can be imaged on the detector D at the initial positions of the first collimator C1 and the second collimator C2, enabling the first collimator C1, the second collimator C2 and the detector D to move at a constant speed, and enabling the actual movement speeds of the first collimator C1, the second collimator C2 and the detector D to be consistent with given movement speed values;
step S012: the first collimator C1 opens a narrow slit to make it form a bright strip 1mm wide on the detector D, and the second collimator C2 moves out of the imaging field of view (the specific position is subsequently determined);
step S002: the first collimator C1 and the detector D move from the initial position L1 to the end position L2 (from the initial position L1 in fig. 1 to the end position L2 in fig. 1) in the direction of the side film shooting movement, and expose during the movement and receive the image;
step S003: analyzing the image: if the image is completely black or the state cannot be analyzed, an error is reported, and an image condition code is given; otherwise, the step of analyzing the calibration data of the first collimator C1 is performed in the following specific manner:
step S031: acquiring a movement initial position S1 and a movement speed V1 of a first collimator C1 by taking the detector D as a reference;
step S032: calculating and recording calibration data of the first collimator C1, compensating the motion state of the first collimator C1, and moving the first collimator C1 and the detector D back to the initial position L1 of the lateral slice shooting motion in the step S002;
step S004: the first collimator C1 moves from the initial position L1 to the end position L2 (from the initial position L1 in fig. 1 to the end position L2 in fig. 1) in the direction of the side sheet photographing movement at the calibrated movement speed, displacement, and exposure during the movement, receiving an image;
step S005: analyzing the image, if the calibration data meets the error requirement (i.e. the calculated result is within an acceptable range, if after multiple calibrations, a moral image is shot in the collimator movement process, the deviation between the center line position of the moral image and the detector center line position is within the range of +/-0.1 mm, the requirement is considered to be met, and the calibration is finished), the first collimator C1 is calibrated, and the process goes to step S006; otherwise, repeating the steps S002 to S005;
step S006: the first collimator C1 and the detector D move back to the side film shooting movement initial position L1 in the step S002, the second collimator C2 returns to the initial position L1 preset in the step S011, the first collimator C1 is opened until the imaging width is 10mm, the purpose is to cover the detector width 8mm, an image is shot for pre-calibration, if the image is formed on the detector D, the step S007 is carried out, and if not, mechanical adjustment is prompted;
step S007: the first collimator C1, the second collimator C2 and the detector D simultaneously start to move from the initial position L1 to the end position L2 (from the initial position L1 in fig. 1 to the end position L2 in fig. 1) in the direction of the side slice shooting movement, and the exposure is performed during the movement to receive the image;
step S008: analyzing the image: if the image is completely black or the state cannot be analyzed, an error is reported, and an image condition code is given; otherwise, the calibration data analysis step of the second collimator C2 is performed in the following specific analysis manner:
step S081: acquiring a movement initial position S2 and a movement speed V2 of a second collimator C2 by taking the detector D as a reference;
step S082: calculating and recording calibration data of the second collimator C2, and compensating the motion state of the second collimator C2, wherein the first collimator C1, the second collimator C2 and the detector D return to the lateral slice shooting motion initial position L1 in the step S007;
step S009: the second collimator C2 moves from the initial position L1 to the end position L2 (from the initial position L1 in fig. 1 to the end position L2 in fig. 1) at the calibrated moving speed and displacement, and the first collimator C1 and the detector D move simultaneously along the side slice shooting moving direction, and the exposure is carried out during the moving process to receive the image;
step S0010: analyzing the image, if the calibration data meets the error requirement (namely the calculated result is in an acceptable range, if after multiple calibrations, a moral image is shot in the movement process of the collimator, the deviation between the central line position of the moral image and the central line position of the detector is within the range of +/-0.1 mm, the requirement is considered to be met, and the calibration is finished), the second collimator C2 is calibrated, the calibration data is stored, and the calibration process is finished; otherwise, steps S007-S0010 are repeated.
Preferably, the calibration data of the first collimator C1 in step S032 and the calibration data of the second collimator C2 in step S082 each include speed calibration data and initial position calibration data;
in step S032, the method for calculating the calibration data of the first collimator C1 includes:
calculating the speed deviation:
taking an image of the part of the image, in which the first collimator C1 moves for a time t, (the time period is selected to ensure that the first collimator C1 is in motion and all images on the detector), and the bright strip exists and the first collimator C1 is in a motion state, calculating the total path of the part of the image, in which the bright strip passes, and calculating the actual moving speed by taking the proportion of the total path of the part of the image, in which the t time passes under normal conditions. As shown in fig. 3, the reconstruction results under normal conditions and speed displacement deviation conditions are shown (in actual conditions, the black areas between the bright stripes are removed by superposition);
Figure BDA0002596711420000121
Snormal＝(index2-index1)*shift；
Figure BDA0002596711420000122
Figure BDA0002596711420000123
initial position deviation calculation: after reconstruction, the bright bar display position of the first frame image is compared with the normal position to obtain a deviation value, the deviation value is proportional to the distance of t time of driving at the actual movement speed, and the time required for moving the deviation distance is calculated, so that the correction distance is calculated. The possible situation of the first frame image is shown in fig. 4;
t＝(index2-index1)/fps；
Figure BDA0002596711420000124
wherein, VC1Is the initial moving speed, V, of the first collimator C1DIs the speed of movement of the detector D, (V)C1And VDSome tolerance is allowed); colmidFor the imaging centerline position (the parameter set in the calculation), t is determined by the number of frames of captured images and the number of frames per second of the picture fps, the time period is chosen to ensure that the first collimator C1 is in motion and both images on the detector SnormalFor a theoretical value of the distance moved over the bright-bar image within time t,
Figure BDA0002596711420000131
is the actual distance that the bright strip moves over the image during time t: (
Figure BDA0002596711420000132
scaleFactor) with a multiple relationship in between), col1For the position of the bright strip of the first frame image in the captured image, col2The position of the bright bar of the last frame image in the intercepted image.
Preferably, the calibration data of the second collimator C2 in step S082 is calculated as follows (assuming that the normal imaging width is w (the imaging range of the second collimator C2 is larger than that of the first collimator C1, and as shown in fig. 5, a partial imaging situation is easy to occur on the detector, so it is determined whether the imaging is left or right based on the first collimator C1)):
step SS 81: detecting the edge in the vertical direction to obtain the column V where the edge is positionedline；
Step SS 82: if only one vertical edge exists, judging whether the edge is a left edge or a right edge;
if it is the right edge, col1＝Vline-w/2；
If it is the left edge, col2＝Vline+w/2；
Step SS 83: the calculation formula of the speed deviation and the initial position deviation of the second collimator C2 is the same as the calculation formula of the speed deviation and the initial position deviation of the first collimator C1;
where w is the normal imaging width.
The position calibration method of the collimator in the head-side shooting mode of the three-in-one equipment is different from the situation that manual adjustment is mostly carried out by means of after-sales personnel in the market. The calibration system is designed by combining the image and the algorithm, so that the image is identified by a computer without the help of human eye observation, and the result is obtained by the algorithm, and then the calibration system is mechanically and automatically adjusted; the precision that manpower can not reach is realized while realizing labour saving and time saving, and the operation degree of difficulty greatly reduced has improved treatment effeciency. Except necessary manual interference, the calibration method can realize automatic standard, manual judgment is not needed after the image is shot, deviation data is calculated through an algorithm and then transmitted to a lower computer, corresponding adjustment can be automatically carried out on a machine, an ideal result can be obtained by carrying out the process at most two times, the time cost is reduced, and the efficiency is high; the operation is simple, and the customer can carry out the operation by himself, so that the waiting time is reduced; the cooperation of the additional tool is reduced, the material is saved, and the cost of adding and storing the additional component by the client is reduced.
In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The preferred embodiments of the invention disclosed above are intended to be illustrative only. The preferred embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims (7)

1. The position calibration method of the collimator under the head-side shooting mode of the three-in-one equipment is characterized by comprising the following steps of:
step S001: initializing a calibration module;
step S002: the first collimator C1 and the detector D move from the initial position L1 to the end position L2 along the direction of the lateral film shooting movement, and the images are received after exposure in the moving process;
step S003: analyzing the image: if the image is completely black or the state cannot be analyzed, an error is reported, and an image condition code is given; otherwise, the step of analyzing the calibration data of the first collimator C1 is performed in the following specific manner:
step S031: acquiring a movement initial position S1 and a movement speed V1 of a first collimator C1 by taking the detector D as a reference;
step S032: calculating and recording calibration data of the first collimator C1, compensating the motion state of the first collimator C1, and moving the first collimator C1 and the detector D back to the initial position L1 of the lateral slice shooting motion in the step S002;
step S004: the first collimator C1 moves from the initial position L1 to the end position L2 along the direction of the side film shooting movement at the calibrated movement speed, displacement and exposure during the movement to receive images;
step S005: analyzing the image, if the calibration data meets the error requirement, completing the calibration of the first collimator C1, and proceeding to step S006; otherwise, repeating the steps S002 to S005;
step S006: the first collimator C1 and the detector D move back to the initial position L1 of the lateral slice photographing movement in the step S002, the second collimator C2 returns to the initial position L1 preset in the step S011, and the first collimator C1 is opened to the imaging width of 10 mm;
step S007: the first collimator C1, the second collimator C2 and the detector D simultaneously start to move from the initial position L1 to the end position L2 along the direction of the lateral slice shooting movement, and the images are received by exposure in the moving process;
step S008: analyzing the image: if the image is completely black or the state cannot be analyzed, an error is reported, and an image condition code is given; otherwise, the calibration data analysis step of the second collimator C2 is performed in the following specific analysis manner:
step S081: acquiring a movement initial position S2 and a movement speed V2 of a second collimator C2 by taking the detector D as a reference;
step S082: calculating and recording calibration data of the second collimator C2, and compensating the motion state of the second collimator C2, wherein the first collimator C1, the second collimator C2 and the detector D return to the lateral slice shooting motion initial position L1 in the step S007;
step S009: the second collimator C2 moves from the initial position L1 to the end position L2 along the direction of the lateral film shooting movement with the calibrated movement speed and displacement and the first collimator C1 and the detector D, and the exposure is carried out in the moving process to receive the image;
step S0010: analyzing the image, if the calibration data meets the error requirement, finishing the calibration of the second collimator C2, storing the calibration data, and ending the calibration process; otherwise, steps S007-S0010 are repeated.
2. The position calibration method of the collimator in the head-side shooting mode of the three-in-one apparatus as set forth in claim 1, wherein: the calibration data of the first collimator C1 in step S032 and the calibration data of the second collimator C2 in step S082 both include speed calibration data and initial position calibration data.
3. The method for calibrating the position of the collimator in the head-side shooting mode of a triple-play plant as claimed in claim 2, wherein the method for calculating the calibration data of the first collimator C1 in step S032 comprises:
calculating the speed deviation:
Figure FDA0002596711410000031
Snormal＝(index2-index1)*shift；
Figure FDA0002596711410000034
Figure FDA0002596711410000032
initial position deviation calculation:
t＝(index2-index1)/fps；
Figure FDA0002596711410000033
wherein, VC1Is the initial moving speed, V, of the first collimator C1DIs the speed of movement of the detector D; colmidFor imaging the position of the center line, t is determined by the number of captured image frames and the number of frames per second fps of the image, SnormalFor a theoretical value of the distance moved over the bright-bar image within time t,
Figure FDA0002596711410000035
for the actual distance the bright bar moves over the image in time t, col1For the position of the bright strip of the first frame image in the captured image, col2The position of the bright bar of the last frame image in the intercepted image.
4. The method for calibrating the position of the collimator in the head-side photographing mode of the triple-play apparatus as claimed in claim 2, wherein the method for calculating the calibration data of the second collimator C2 in the step S082 comprises:
step SS 81: detecting the edge in the vertical direction to obtain the column V where the edge is positionedline；
Step SS 82: if only one vertical edge exists, judging whether the edge is a left edge or a right edge;
if it is the right edge, col1＝Vline-w/2；
If it is the left edge, col2＝Vline+w/2；
Step SS 83: the calculation formula of the speed deviation and the initial position deviation of the second collimator C2 is the same as the calculation formula of the speed deviation and the initial position deviation of the first collimator C1;
where w is the normal imaging width.
5. The method for calibrating the position of the collimator in the head-side shooting mode of the three-in-one device of claim 1, wherein the step S001 of initializing the calibration module comprises the following steps:
step S011: moving the first collimator C1 and the detector D to the initial position L1 of the head-side photographing mode, so as to ensure that the X-rays can be imaged on the detector D at the initial positions of the first collimator C1 and the second collimator C2;
step S012: the first collimator C1 opens a narrow slit to allow a 1mm wide bright stripe on the detector D, and the second collimator C2 moves out of the imaging field of view.
6. The position calibration method of the collimator in the upper head-side shooting mode of the three-in-one device as claimed in claim 1, wherein the calibration module is initialized in the step S001, and then an image is shot for pre-calibration, if the image is formed on the detector D, the step S002 is performed, otherwise, the mechanical adjustment is prompted; an image is taken after step S006 to perform pre-calibration, if the image is formed on the detector D, step S007 is performed, otherwise, mechanical adjustment is prompted.
7. The method of claim 1, wherein the error is within ± 0.1mm of the collimator centerline position and the detector centerline distance.
CN202010711506.9A 2020-07-22 2020-07-22 Position calibration method of collimator in three-in-one equipment upper head side shooting mode Pending CN111759343A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010711506.9A CN111759343A (en) 2020-07-22 2020-07-22 Position calibration method of collimator in three-in-one equipment upper head side shooting mode

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010711506.9A CN111759343A (en) 2020-07-22 2020-07-22 Position calibration method of collimator in three-in-one equipment upper head side shooting mode

Publications (1)

Publication Number Publication Date
CN111759343A true CN111759343A (en) 2020-10-13

Family

ID=72727061

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010711506.9A Pending CN111759343A (en) 2020-07-22 2020-07-22 Position calibration method of collimator in three-in-one equipment upper head side shooting mode

Country Status (1)

Country Link
CN (1) CN111759343A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112837980A (en) * 2020-12-31 2021-05-25 山东微波电真空技术有限公司 Method for adjusting spiral line

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010110498A (en) * 2008-11-07 2010-05-20 Fujifilm Corp Imaging device
US20130058462A1 (en) * 2011-09-01 2013-03-07 Hologic Inc. Independently rotatable detector plate for medical imaging device
US20180021007A1 (en) * 2015-04-03 2018-01-25 Trophy Method and apparatus for aligning of cephalometric imaging device collimator
CN109124678A (en) * 2018-07-12 2019-01-04 深圳市菲森科技有限公司 A kind of auto-correction method of dentistry head shadow filming apparatus
CN109770935A (en) * 2018-12-28 2019-05-21 上海联影医疗科技有限公司 Collimator bearing calibration, device, CT system and storage medium
CN109803586A (en) * 2016-05-09 2019-05-24 新维沃有限公司 For chromatographing compound imaging system, method and computer-readable medium in the static mouth of three-dimensional dental imaging

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010110498A (en) * 2008-11-07 2010-05-20 Fujifilm Corp Imaging device
US20130058462A1 (en) * 2011-09-01 2013-03-07 Hologic Inc. Independently rotatable detector plate for medical imaging device
US20180021007A1 (en) * 2015-04-03 2018-01-25 Trophy Method and apparatus for aligning of cephalometric imaging device collimator
CN109803586A (en) * 2016-05-09 2019-05-24 新维沃有限公司 For chromatographing compound imaging system, method and computer-readable medium in the static mouth of three-dimensional dental imaging
CN109124678A (en) * 2018-07-12 2019-01-04 深圳市菲森科技有限公司 A kind of auto-correction method of dentistry head shadow filming apparatus
CN109770935A (en) * 2018-12-28 2019-05-21 上海联影医疗科技有限公司 Collimator bearing calibration, device, CT system and storage medium

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112837980A (en) * 2020-12-31 2021-05-25 山东微波电真空技术有限公司 Method for adjusting spiral line
CN112837980B (en) * 2020-12-31 2024-06-04 山东微波电真空技术有限公司 Spiral line adjusting method

Similar Documents

Publication Publication Date Title
US7488107B2 (en) Method and apparatus to detect and correct alignment errors in x-ray systems used to generate 3D volumetric images
CN101854863B (en) Movable wedge for improved image quality in 3D X-ray imaging
EP1484016B1 (en) Method and apparatus for acquisition of a composite image with a digital detector
US7559694B2 (en) Method for acquisition geometry of an imaging system
US20020097831A1 (en) X-ray computer tomography scanning system
KR20070051758A (en) X-ray ct apparatus and x-ray ct fluoroscopic apparatus
US8622615B2 (en) Calibration device for location of CT x-ray generator and detector, calibration method using the calibration device, and calibration method for CT system
US20100290707A1 (en) Image acquisition method, device and radiography system
US20030081734A1 (en) Low-dose exposure aided positioning (LEAP) for digital radiography
US8848876B2 (en) Radiographic apparatus
KR101094180B1 (en) Methode and Apparatus for Obtaining Panoramic Image
EP0982603A2 (en) Methods and apparatus for imaging system detector alignment
US7085345B2 (en) Radiation computed tomographic imaging apparatus and radiation detector for use therein
EP1321900A2 (en) Method and apparatus for noise reduction in computed tomographic systems
US20180192975A1 (en) System and Method of Small Field of View X-ray Imaging
EP0973047A2 (en) Methods and apparatus for reducing z-axis non-uniformity artifacts
JP2006312047A (en) Method of calculating x-ray attenuation in orthogonal cross direction of object, computer tomographic photography device, and correction module therefor
CN111759343A (en) Position calibration method of collimator in three-in-one equipment upper head side shooting mode
CN110559001A (en) Defocusing radiation intensity distribution measuring method of CT scanner
US7670049B2 (en) X-ray radiography apparatus and arrangement method of plane of rotation
KR101473531B1 (en) Adaptive Sensor Unit, X-ray Imaging Appratus and X-ray Imaging Method
CN114423349A (en) Image detection device, console, and radiographic system
EP3370618B1 (en) Dynamic image data treatment in dental imaging devices
DE102008052976B4 (en) tracking system
CN114159090A (en) Dental panoramic shooting device and automatic correction method

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination