CN119318501A

CN119318501A - X-ray imaging system and oral panorama reconstruction method thereof

Info

Publication number: CN119318501A
Application number: CN202411535891.0A
Authority: CN
Inventors: 陆小旗; 周宇
Original assignee: Beijing Chenlan Medical Technology Co ltd
Current assignee: Beijing Chenlan Medical Technology Co ltd
Priority date: 2024-10-31
Filing date: 2024-10-31
Publication date: 2025-01-17
Anticipated expiration: 2044-10-31
Also published as: CN119318501B

Abstract

The application discloses an X-ray imaging system and an oral cavity panorama reconstruction method, and relates to the technical field of radiodiagnosis. The method comprises the steps of obtaining an arch curve of a user, obtaining a plurality of sampling points based on the arch curve, controlling the horizontal boom to rotate and the positions of the X-ray source and the X-ray sensor based on the sampling points, obtaining perspective views corresponding to the sampling points one by one, and obtaining an oral panoramic view based on the perspective views. The exposure assembly in the application only needs to perform simple rotary motion or linear motion, and does not need to perform complex curve motion. Relative to complex curvilinear motions, rotational and linear motions are easy to control with precision. Namely, the application can obtain the perspective view with higher precision, and further obtain the oral cavity panoramic view with higher precision.

Description

X-ray imaging system and oral panorama reconstruction method thereof

Technical Field

The application relates to the technical field of radiodiagnosis, in particular to an X-ray imaging system and an oral panorama reconstruction method thereof.

Background

In order to obtain an oral panoramic view of a user, an X-ray imaging system is generally adopted in the prior art to obtain perspective views of various points on a dental arch curve of the user, and then the perspective views are overlapped to obtain the oral panoramic view. It should be clear that existing X-ray imaging systems comprise an X-ray source and an X-ray sensor, and that the distance between the X-ray source and the X-ray sensor is constant (i.e. not adjustable), and that in use the X-ray imaging system requires not only a rotation of the X-ray source and the X-ray sensor by means of a rotation axis, but also a complicated curved movement of the rotation axis (see for specific reasons the description). For example, patent document CN202010686999.5, entitled multi-mode oral CBCT device, discloses a similar X-ray imaging system.

It should be clear that, if the movement trajectories of the rotation axis, the X-ray source, and the X-ray sensor (hereinafter simply referred to as an exposure module) are curved, it is difficult to precisely control the movement trajectories of the exposure module. If it is difficult to precisely control the movement track of the exposure module, it is difficult to obtain a high-precision perspective view, that is, a high-precision oral panorama.

Disclosure of Invention

The application aims to provide an X-ray imaging system and an oral panorama reconstruction method thereof, so as to solve the technical problem that the motion trail of an exposure component is difficult to accurately control.

In order to achieve the above purpose, the present application provides the following technical solutions:

In a first aspect, the present application provides a technical solution of an oral panorama reconstruction method, which is applied to an X-ray imaging system, wherein the X-ray imaging system includes a horizontal boom, an X-ray source disposed at a first end of the horizontal boom, and an X-ray sensor disposed at a second end of the horizontal boom, the X-ray source and the X-ray sensor are both capable of moving along a length direction of the horizontal boom, the horizontal boom is capable of rotating around a first axis, the first axis is parallel to a vertical direction, and the oral panorama reconstruction method includes:

acquiring a dental arch curve of a user;

Acquiring a plurality of sampling points based on the dental arch curve;

Controlling the rotation of the horizontal boom and the positions of the X-ray source and the X-ray sensor based on the plurality of sampling points, and obtaining perspective views corresponding to the sampling points one by one;

based on the multiple perspectives, an oral panorama is acquired.

As a specific solution in the technical solution of the present application, the obtaining a plurality of sampling points based on the dental arch curve includes:

Acquiring a scanning step angle, wherein the scanning step angle is preset;

acquiring a scanning total angle based on the dental arch curve and a target point, wherein the target point is an intersection point formed by the first axis and a plane where the dental arch curve is positioned;

and acquiring a plurality of sampling points based on the scanning step angle and the scanning total angle.

As a specific aspect of the present application, the controlling the rotation of the horizontal boom and the positions of the X-ray source and the X-ray sensor based on the plurality of sampling points includes:

Acquiring a current sampling point and a historical sampling point based on the plurality of sampling points, wherein the current sampling point and the historical sampling point are adjacent sampling points;

acquiring a first distance based on the current sampling point and the target point;

acquiring a second distance based on the history sampling point and the target point;

acquiring an adjustment distance based on the first distance and the second distance;

And adjusting the positions of the X-ray source and the X-ray sensor based on the adjustment distance in a period of time when the horizontal boom is rotated from the historical sampling point to the current sampling point.

As a specific solution in the technical solution of the present application, after the dental arch curve of the user is obtained, the method further includes:

acquiring a target point based on the dental arch curve, wherein the target point comprises a point with the smallest change of the distance from each point on the dental arch curve in the plane of the dental arch curve;

the position of the first axis is adjusted so that the first axis passes through the target point.

As a specific solution in the technical solution of the present application, the obtaining the target point based on the dental arch curve includes:

acquiring a plurality of curve points based on the dental arch curve, wherein the curve points are any points in the dental arch curve;

Acquiring a plurality of predicted points based on the dental arch curve, wherein the predicted points are any points in a plane where the dental arch curve is positioned;

Obtaining a third distance between each predicted point and a plurality of curve points;

based on a plurality of third distances, acquiring variances corresponding to each predicted point one by one;

And acquiring the target point from the plurality of predicted points based on the variance.

As a specific aspect of the present application, the acquiring, based on the variance, the target point from the plurality of predicted points includes:

Acquiring a first predicted point, a second predicted point and a third predicted point which are not collinear based on the plurality of predicted points, wherein the first predicted point, the second predicted point and the third predicted point are three predicted points with the smallest variance in the plurality of predicted points, and the first variance, the second variance and the third variance which are sequentially corresponding to the first predicted point, the second predicted point and the third predicted point are increased in size;

Acquiring a center point based on the first predicted point, the second predicted point and the third predicted point;

Acquiring a reference point based on the central point and a third predicted point, wherein the reference point is any point far away from the central point along a first direction, and the first direction points to the central point from the third predicted point;

acquiring a fourth difference based on the reference point;

If the fourth square difference meets a first preset condition, acquiring the target point based on the first variance and the fourth variance, otherwise, updating the third predicted point.

As a specific solution in the technical solution of the present application, the updating the third prediction point includes:

If the fourth difference is smaller than the first variance, the third predicted point is updated to be any point far from the central point along the first direction;

if the fourth square difference is larger than the first variance and smaller than the third variance, the third predicted point is updated to the reference point;

And if the fourth square difference is larger than the third variance, updating the third predicted point to be any point on a connecting line between the central point and the third predicted point.

As a specific scheme in the technical scheme of the application, the first preset condition comprises that the update times of the third predicted point is larger than a first preset value, or the absolute value of the difference between the fourth variance and a target variance is smaller than a second preset value, and the target variance comprises the first variance or the average value of the first variance, the second variance and the third variance.

As a specific solution in the technical solution of the present application, the obtaining a plurality of curve points based on the dental arch curve includes:

Acquiring the selected number of the curve points, wherein the selected number is preset;

Based on the dental arch curve, randomly acquiring a plurality of curve points with the same number as the selected number;

Or the plurality of curve points comprise two end points of the dental arch curve, and the step of acquiring the plurality of curve points based on the dental arch curve comprises the following steps:

based on the dental arch curve and the selected number, a plurality of curve points are obtained, and the distances between adjacent curve points are equal.

In a second aspect, the present application proposes a technical solution of an X-ray imaging system, the X-ray imaging system comprising:

the horizontal suspension arm can rotate around a first shaft in a central mode, and the first shaft is parallel to the vertical direction;

The X-ray source is arranged at the first end of the horizontal suspension arm, and the X-ray sensor is arranged at the second end of the horizontal suspension arm;

A reader for acquiring a dental arch curve of a user;

the processor is used for acquiring a plurality of sampling points based on the dental arch curve;

The controller is used for controlling the horizontal boom to rotate and the positions of the X-ray source and the X-ray sensor based on the sampling points to obtain perspective views corresponding to the sampling points one by one;

the processor is also configured to obtain an oral panorama based on the plurality of perspectives.

As a specific scheme in the technical scheme of the application, the reader is also used for acquiring a scanning step angle, wherein the scanning step angle is preset;

The processor is further used for acquiring a scanning total angle based on the dental arch curve and a target point, wherein the target point is an intersection point formed by the first axis and a plane where the dental arch curve is located;

As a specific scheme in the technical scheme of the application, the reader is also used for acquiring a current sampling point and a historical sampling point based on the plurality of sampling points, wherein the current sampling point and the historical sampling point are adjacent sampling points;

The processor is further configured to obtain a first distance based on the current sampling point and the target point;

And acquiring a second distance based on the history sampling point and the target point;

and obtaining an adjustment distance based on the first distance and the second distance;

the controller is further configured to adjust the positions of the X-ray source and the X-ray sensor based on the adjustment distance during a time period when the horizontal boom is rotated from the historical sampling point to a current sampling point.

The processor is further used for acquiring a target point based on the dental arch curve, wherein the target point comprises a point with the smallest change of distance from each point on the dental arch curve in a plane where the dental arch curve is positioned;

the controller is also configured to adjust a position of the first axis to pass the first axis through the target point.

As a specific scheme in the technical scheme of the application, the processor is also used for acquiring a plurality of curve points based on the dental arch curve, wherein the curve points are any points in the dental arch curve;

The method comprises the steps of obtaining a plurality of predicted points based on the dental arch curve, wherein the predicted points are any points in a plane where the dental arch curve is located;

The processor is further used for acquiring a first predicted point, a second predicted point and a third predicted point which are not collinear based on the plurality of predicted points, wherein the first predicted point, the second predicted point and the third predicted point are three predicted points with the smallest variance among the plurality of predicted points;

The method comprises the steps of obtaining a reference point based on the central point and a third predicted point, wherein the reference point is any point far away from the central point along a first direction, and the first direction points to the central point from the third predicted point;

And, based on the reference point, obtaining a fourth difference;

And if the fourth square difference meets a first preset condition, acquiring the target point based on the first variance and the fourth variance, and otherwise, updating the third predicted point.

As a specific solution in the present application, the processor is further configured to update the third predicted point to an arbitrary point far from the center point along the first direction if the fourth difference is smaller than the first variance;

And if the fourth difference is greater than the first variance and less than the third variance, updating the third predicted point to the reference point;

And if the fourth difference is greater than the third variance, updating the third predicted point to be an arbitrary point on a line between the center point and the third predicted point.

As a specific scheme in the technical scheme of the application, the reader is also used for acquiring the selected number of the curve points, wherein the selected number is preset;

The processor is further used for randomly acquiring a plurality of curve points with the same number as the selected number based on the dental arch curve;

the reader is further used for acquiring the selected number of the curve points, wherein the selected number is preset;

the processor is further used for acquiring a plurality of curve points based on the dental arch curves and the selected number, and the distances between the adjacent curve points are equal.

Compared with the prior art, the application has the beneficial effects that:

The exposure component in the embodiment of the application only needs to perform simple rotary motion or linear motion, and does not need to perform complex curve motion. Relative to complex curvilinear motions, rotational and linear motions are easy to control with precision. Namely, the application can obtain the perspective view with higher precision, and further obtain the oral cavity panoramic view with higher precision.

Drawings

FIG. 1 is a schematic diagram of an X-ray imaging system according to an embodiment of the present application;

FIG. 2 is a schematic diagram illustrating the motion of an exposure module according to the prior art;

fig. 3 is a schematic flow chart of an oral panorama reconstructing method according to an embodiment of the present application;

FIG. 4 is a schematic view illustrating the motion of an X-ray source and an X-ray sensor according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a total scan angle according to an embodiment of the present application;

FIG. 6 is a schematic diagram of acquiring each sampling point according to an embodiment of the present application;

FIG. 7 is a schematic view illustrating the movement of an X-ray source and an X-ray sensor according to another embodiment of the present application;

FIG. 8 is a schematic diagram of a target point obtained manually according to an embodiment of the present application;

FIG. 9 is a schematic diagram of predicted points and curve points according to an embodiment of the present application;

fig. 10 is a schematic diagram of acquiring a target point based on a lattice according to an embodiment of the present application;

FIG. 11 is a schematic diagram of another embodiment of the present application for acquiring a target point based on a lattice;

fig. 12 is a schematic diagram of an acquisition center and a reference point based on a first predicted point, a second predicted point and a third predicted point according to an embodiment of the present application;

Fig. 13 is a schematic diagram of a moving path of an X-ray source according to an embodiment of the present application.

In the figure, 1, a horizontal boom, 2, an X-ray source, 3, an X-ray sensor, 4, a reader, 5, a processor, 6, a controller, 7, a user, 8, a dental arch curve, 9, a moving track, 10 and a central area.

Detailed Description

The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. It will be apparent that the described embodiments are only some, but not all, embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The terms first, second and the like in the description and in the claims of the embodiments of the application and in the above-mentioned figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order, such as the first and second predicted points presented hereinafter, which may be of different nature. It is to be understood that the points so used may be interchanged where appropriate, such that the embodiments described herein may be implemented in other sequences than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or modules is not necessarily limited to those explicitly listed but may include other steps or modules not expressly listed or inherent to such process, method, article, or apparatus, such that the partitioning of modules by embodiments of the application is only one logical partitioning, may be implemented with additional partitioning, such as a plurality of modules may be combined or integrated in another system, or some features may be omitted, or not implemented, and further, such that the coupling or direct coupling or communication connection between modules may be via some interfaces, indirect coupling or communication connection between modules may be electrical or otherwise similar, none of which are limited in embodiments of the application. The modules or sub-modules described as separate components may or may not be physically separate, may or may not be physical modules, or may be distributed in a plurality of circuit modules, and some or all of the modules may be selected according to actual needs to achieve the purposes of the embodiment of the present application.

Before understanding the embodiments of the present application, it should be clear that the prior art method of obtaining a perspective view of various points on a dental arch curve using an X-ray imaging system based on the dental arch curve is shown in fig. 2. The movement trace of the rotation axis is shown as a movement trace 9 in fig. 2, and the dental arch curve of the user 7 is shown as a dental arch curve 8 in fig. 2, that is, the movement trace 9 and the dental arch curve 8 are similar curves. Assuming that the point D2 and the point D4 on the arch curve 8 are two adjacent exposure points (in the actual process, a plurality of exposure points are needed between the point D2 and the point D4, so that the far-distance point D2 and the far-distance point D4 are selected as the adjacent exposure points on the arch curve 8 in fig. 2 for the sake of easy observation and understanding). That is, if a perspective view of the dental arch curve 8 at the point D2 after exposure is obtained, a perspective view of the dental arch curve 8 at the point D4 needs to be obtained next. As shown in fig. 2, in order to obtain a clear exposure map for each exposure, the distance S between the X-ray source 2 and the X-ray sensor 3 needs to be constant and it needs to be ensured that the distances between the X-ray source 2 and the exposure point on the dental arch curve 8 are equal (cannot be completely equal, but can be approximately equal) at each exposure position. That is, as shown in fig. 2, the distance L1 and the distance L2 need to be as equal as possible. In other words, after the prior art acquires the perspective view of the point D2 on the dental arch curve 8, if it is required to acquire the perspective view of the point D4 on the dental arch curve 8, it is required to move the rotation axis from the point D1 to the point D3 on the movement track 9 along the movement track 9 so that the distance L1 and the distance L2 are equal, and during this period, it is also required to rotate the X-ray source 2 and the X-ray sensor 3 so that the line between the X-ray source 2 and the X-ray sensor 3 passes through the point D4 (i.e., the exposure point).

In view of the above, the prior art needs to control not only the rotation axis, the X-ray source 2, and the X-ray sensor 3 (i.e., the exposure assembly) in the X-ray imaging system to perform complex curved motion, but also the rotation axis-based rotation of the X-ray source 2 and the X-ray sensor 3. It is easy to understand that the accurate control exposure subassembly carries out the curvilinear motion, and technical requirement is higher, and the realization degree of difficulty is great.

In order to solve the technical problems and improve the control accuracy of the motion trail of the exposure assembly, the application provides an embodiment of an oral cavity panorama reconstruction method, and the oral cavity panorama reconstruction method is particularly applied to an X-ray imaging system. As shown in fig. 1, the X-ray imaging system comprises a horizontal boom 1, an X-ray source 2 arranged at a first end of the horizontal boom 1, and an X-ray sensor 3 arranged at a second end of the horizontal boom. The X-ray source 2 and the X-ray sensor 3 are both movable along the length direction of the horizontal boom 1 (i.e. direction a in fig. 1). The horizontal boom 1 is capable of centre rotation about a first axis, which is parallel to the vertical direction.

It should be clear that controlling the rotation of the horizontal boom 1 is a mature technique, which is not described here in detail. A linear motion structure (e.g., a linear rail or a screw drive structure, etc.) may be provided between the X-ray source 2 and the horizontal boom 1 to enable the X-ray source 2 to move along the length of the horizontal boom 1. Of course, a linear motion structure may be disposed between the X-ray sensor 3 and the horizontal boom 1, which is not described herein. Since the linear motion structure that can make two parts (i.e., the horizontal boom 1 and the X-ray source 2, or the horizontal boom 1 and the X-ray sensor 3) generate the linear relative motion is also a mature technology, too, a detailed description will be omitted here.

Specifically, as shown in fig. 3, the method for reconstructing an oral panorama according to the embodiment of the present application includes steps S100 to S400.

And S100, acquiring a dental arch curve of the user.

In embodiments of the present application, the user's arch curve may be obtained in any manner. For example, a method proposed in patent document, which is named as a method for generating a dental arch curved surface based on CBCT image, may be used to obtain a dental arch curve of a user based on CBCT image, as in patent grant No. CN 112102495B. Alternatively, the dental arch curve of the user may be obtained based on binocular vision as proposed in patent application document number 202010655271.6, entitled a method for obtaining a dental arch curve of a human body based on binocular vision. That is, in embodiments of the present application, the user's arch curve may be obtained based on any method. Since there are many methods for obtaining the dental arch curve of the user in the prior art, a detailed description is not given here to avoid redundancy.

And step 200, acquiring a plurality of sampling points based on the dental arch curve.

It should be clear that in embodiments of the present application, a plurality of sampling points may be acquired in any manner based on the dental arch curve. For example, in an embodiment of the present application, a plurality of sampling points may be acquired randomly on the dental arch curve, or a plurality of sampling points may be acquired on the dental arch curve, and the distances between adjacent sampling points are equal.

It should be clear that fig. 4 is a schematic view (in top view) of the motion of an X-ray source 2 and an X-ray sensor 3 (i.e. an exposure module) according to an embodiment of the present application. The intersection point formed by the first axis and the plane in which the dental arch line 8 lies is defined as the target point (i.e., point D5 in fig. 4), and as shown in fig. 4, the first axis is perpendicular to the paper surface direction. Suppose the points D2 and D4 on the arch curve 8 are two adjacent exposure points (i.e., the same as the two exposure points in fig. 2). That is, if a perspective view of the dental arch curve 8 at the point D2 after exposure is obtained, a perspective view of the dental arch curve 8 at the point D4 needs to be obtained next. From the foregoing, it is clear that the distance S between the X-ray source 2 and the X-ray sensor 3 needs to be constant during the acquisition of the respective perspective views. In order to be able to obtain a clear exposure map for each exposure, it is necessary to ensure that the distance of the X-ray source 2 from the exposure point (i.e. the sampling point hereinafter) on the arch curve 8 should be as equal as possible at each exposure position. That is, as shown in fig. 4, when exposing the point D2, the distance L1 from the X-ray source 2 to the point D2 is required to be as equal as possible to the distance L2 from the X-ray source 2 to the point D4 when exposing the point D4.

In the embodiment of the application, after the acquisition of the perspective view of the point D2, it is only necessary to rotate the horizontal boom 1 about the first axis (i.e. the target point D5) (the direction of rotation is the direction C shown in fig. 4) so that the line between the X-ray source 2 and the X-ray sensor 3 passes through the point D4, during which it is also necessary to move the X-ray source 2 and the X-ray sensor 3 in the first direction (i.e. the length direction of the horizontal boom 1) so that the distance L1 and the distance L2 are equal.

It should be clear that, as shown in fig. 2 and 4, the various components (e.g., the horizontal boom, the X-ray source, and the X-ray sensor) in the embodiments of the present application need only perform a simple rotational motion or a linear motion, which does not require a complex curvilinear motion, as compared to the prior art. For the accurate curvilinear motion of control exposure subassembly, the accurate rectilinear motion of control exposure subassembly is comparatively simple. In the embodiment of the application, parts such as the horizontal suspension arm and the rotating shaft do not need to perform linear motion, and compared with the prior art that the rotating shaft needs to perform linear motion together with the X-ray source and the X-ray sensor, the embodiment of the application has relatively low motion inertia when in use.

It should be clear that in order to be able to accurately acquire the perspective view after exposure at each sampling point. It is necessary to adjust the X-ray source 2 and the X-ray sensor 3 to a preset position at the same timing when the line between the X-ray source 2 and the X-ray sensor 3 passes through the sampling point (e.g., D2 and D4 in fig. 4) (i.e., the interval between the X-ray source 2 and the X-ray sensor 3 needs to be maintained at S in fig. 4, the distance between the X-ray source 2 and the sampling point is L1, l1=l2 in fig. 4), and the X-ray source 2 needs to be exposed at the same timing. That is, at each sampling point, the above three actions need to be performed synchronously.

If the sampling points are acquired in a random manner, it is difficult to achieve complete synchronization of the three actions in the subsequent control process. In order to facilitate the subsequent control of the synchronous implementation of the above three actions, in one embodiment of the present application, step S200, a plurality of sampling points are acquired based on the dental arch curve, including steps S210 to S230.

Step S210, acquiring a scanning step angle.

It should be clear that, in order to facilitate the subsequent control, in the embodiment of the present application, the horizontal boom 1 may be controlled to rotate at a constant speed, and the above three actions are controlled to be synchronized with a scanning step angle (i.e., a rotation angle of the horizontal boom 1). In this embodiment, the scanning step angle may be preset according to the requirement, for example, the scanning step angle may be 0.10 °, 0.15 °, or 0.20 °.

And step 220, acquiring a scanning total angle based on the dental arch curve and the target point.

Specifically, the target point is an intersection point formed by the first axis and a plane where the dental arch curve 8 is located. The total scan angle in this embodiment is shown as angle B in fig. 5. Wherein the line between the target point and the first end of the dental arch line 8 is defined as a first line segment, and the line between the target point and the second end of the dental arch line 8 is defined as a second line segment. The angle B is an included angle formed by the first line segment and the second line segment and facing the dental arch curve 8.

And step S230, acquiring a plurality of sampling points based on the scanning step angle and the scanning total angle.

In a specific embodiment of the present application, if the angle B is 270 °, the scanning step angle is 0.15 °, the number of acquired sampling points is 1800 °. Specifically, as shown in fig. 6, the obtained sampling points are shown in fig. 6, the point D5 is the target point, and each hollow circle on the dental arch curve 8 represents each sampling point.

And step 300, controlling the rotation of the horizontal boom 1 and the positions of the X-ray source 2 and the X-ray sensor 3 based on the plurality of sampling points, and acquiring perspective views corresponding to the sampling points one by one.

It should be clear that, in the embodiment of the present application, the rotation of the horizontal boom, the positions of the X-ray source and the X-ray sensor may be controlled in any manner based on the plurality of sampling points, so as to obtain perspective views corresponding to the sampling points one by one.

In a specific embodiment of the present application, step S300, based on the plurality of sampling points, controlling the rotation of the horizontal boom 1, the positions of the X-ray source 2 and the X-ray sensor 3, and obtaining the perspective corresponding to each sampling point one by one includes steps S310 to S350.

Step S310, based on the plurality of sampling points, acquiring a current sampling point and a historical sampling point.

In an embodiment of the present application, the current sampling point and the historical sampling point are adjacent sampling points. For example, as shown in fig. 4, assuming that the D2 point and the D4 point are adjacent sampling points, if the current sampling point is D4, the D2 point is a history sampling point.

Step 320, based on the current sampling point and the target point, acquiring a first distance.

It should be clear that the first distance is the distance between the current sampling point and the target point, and the distance between the two points is obtained as a mature technique, which is not described herein.

And step S330, acquiring a second distance based on the history sampling point and the target point.

It should be clear that the second distance is the distance between the history sampling point and the target point, and the distance between the two points is obtained as a mature technique, which is not described here in detail.

Step S340, based on the first distance and the second distance, obtaining an adjustment distance.

It is clear that the adjustment distance is the difference between the first distance and the second distance. As shown in fig. 4, assuming that the distance between the target point D5 and the history sampling point D2 is S1 and the distance between the target point D5 and the current sampling point is S2, the adjustment distance is S2-S1.

And step 350, adjusting the positions of the X-ray source and the X-ray sensor based on the adjustment distance in the period of time when the horizontal boom 1 rotates from the historical sampling point to the current sampling point.

As can be seen from the foregoing, in the present embodiment, the time for the horizontal boom 1 to rotate to each sampling point is the same. That is, in the present embodiment, as shown in fig. 4, the X-ray source and the X-ray sensor may be adjusted to the corresponding positions based on the adjustment distance before the horizontal boom 1 is rotated from the point D2 to the point S4.

It will be readily appreciated that if the adjustment distance is positive, it will be explained that the positions of the X-ray source and the X-ray sensor need to be adjusted in a first direction (i.e. the length direction of the horizontal boom 1) in a direction away from the target point D5, and that if the adjustment distance is negative, it will be explained that the positions of the X-ray source and the X-ray sensor need to be adjusted in the opposite direction of the above direction.

Step S400, obtaining an oral panorama based on the plurality of perspective views.

It should be clear that, based on multiple perspective views, obtaining an oral panorama is a mature technique, and will not be described in detail herein.

The various components of embodiments of the present application (e.g., the horizontal boom, the X-ray source, and the X-ray sensor) need only perform simple rotational or linear movements, which do not require complex curvilinear movements. Compared with complex curve motion, the rotary motion and the linear motion are easy to precisely control, and the motion inertia generated by the linear motion is small.

It should be clear that the combined weight of the rotation axis, the X-ray source and the X-ray sensor of the prior art is relatively heavy. The acceleration and deceleration of the X-ray imaging system in the process of curve motion can generate larger motion inertia, so that the X-ray imaging system generates vibration. In the process of acquiring each perspective view, if the X-ray imaging system vibrates, the error of the acquired oral panorama is larger due to light weight, the X-ray imaging system is deformed due to heavy weight, and the service life is reduced. In the embodiment of the application, the parts such as the horizontal suspension arm and the rotating shaft do not need to perform linear movement, and compared with the situation that the rotating shaft in the prior art needs to perform linear movement together with the X-ray source and the X-ray sensor, the moment of inertia is further reduced when the embodiment of the application is used.

From the foregoing, it is necessary to move the X-ray source and the X-ray sensor a distance S2-S1 on the horizontal boom 1 before the horizontal boom 1 is rotated from point D2 to point S4. It will be readily appreciated that the greater the value of S2-S1, the greater the moment of inertia created during movement of the X-ray source and X-ray sensor, and the lesser the value of S2-S1, the lesser the moment of inertia created during movement of the X-ray source and X-ray sensor.

In order to further reduce the moment of inertia created during the movement of the X-ray source and the X-ray sensor, in one embodiment of the application, after step S100, the method further comprises step S500 and step S600 after the dental arch curve of the user is acquired.

It should be clear that, in the embodiment of the present application, the steps S100 to S600 do not represent the sequential execution order of the steps, which is only for distinguishing between the different steps.

And S500, acquiring a target point based on the dental arch curve.

It should be clear that the target point may be the point in the plane of the dental arch curve where the distance from each point on the dental arch curve is the smallest (hereinafter referred to as the optimal point). It is easy to understand that if the target point is a point with the smallest distance change from each point on the dental arch curve in the plane of the dental arch curve, the moving distance between the X-ray source and the X-ray sensor is also smallest in the subsequent control process, that is, the moment of inertia formed during the moving process of the X-ray source and the X-ray sensor can be minimized.

Specifically, fig. 7 is a schematic diagram showing the motion (in top view) of the X-ray source 2 and the X-ray sensor 3 (i.e. the exposure module) according to another embodiment of the present application, where the point D5 is the optimal point. As can be seen from the embodiments of fig. 4 and 7, from point D2 to point D4, the movement distance of the X-ray source 2 and the X-ray sensor 3 in the embodiment of fig. 4 is significantly longer than the movement distance of the X-ray source 2 and the X-ray sensor 3 in the embodiment of fig. 7. That is, the moment of inertia formed by the X-ray source 2 and the X-ray sensor 3 in the embodiment of fig. 7 must be smaller than the moment of inertia formed by the X-ray source 2 and the X-ray sensor 3 in the embodiment of fig. 4.

It is clear that during practical operation it is difficult to obtain the optimal point in the plane of the dental arch curve. In this embodiment, therefore, the target point may be any point near the optimal point. That is, in the present embodiment, the target point may be acquired in an arbitrary manner based on the arch curve. For example, the target point may be determined manually based on the naked eye. As shown in fig. 8, when the distances from the point D5 to the points on the dental arch curve 8 are substantially uniform by visual observation, the point D5 may be directly used as the target point.

In order to improve the accuracy of the acquired target point, i.e. to make the target point closer to the optimal point, in one embodiment of the present application, step S500 acquires the target point based on the dental arch curve, including steps S510 to S550.

And S510, acquiring a plurality of curve points based on the dental arch curve.

It should be clear that the curve point is any point in the arch curve. In this embodiment, a plurality of curve points may be obtained by an arbitrary method based on the dental arch curve. For example, in one embodiment of the present application, step S510 obtains a plurality of curve points based on the dental arch curve, including step S511 and step S512.

Step S511, obtaining the selection number of the curve points.

In an embodiment of the present application, the selected number is preset. That is, the number of curve points is not limited in this embodiment, and for example, the number of curve points may be 20 or 100 or 200 or the like.

Step S512, based on the dental arch curve, a plurality of curve points with the same number as the selected number are randomly acquired.

It is clear that the curve points acquired by the method can be effectively prevented from being too concentrated in a random acquisition mode, and the accuracy of the target points acquired subsequently is further affected.

In another embodiment of the present application, the plurality of curve points includes two end points of the dental arch curve, and step S510 includes obtaining a plurality of curve points based on the dental arch curve, including step S513 and step S514.

Step S513, obtaining the selection number of the curve points.

In an embodiment of the present application, the selected number is preset. That is, the number of curve points is not limited in this embodiment, and for example, the number of curve points may be 10 or 80 or 1000 or the like.

Step S514, based on the dental arch curves and the selected number, a plurality of curve points are obtained, and the distances between adjacent curve points are equal.

That is, in the present embodiment, if the dental arch curve length is T and the number of curve points is Z, one point is selected as a curve point on the dental arch curve at intervals of T/(Z-1) from any one end point of the dental arch curve. The mode can select curve points at each part of the dental arch curve, and then more accurate target points can be obtained in the subsequent steps.

And step S520, acquiring a plurality of predicted points based on the dental arch curve.

It should be clear that in an embodiment of the present application, the predicted point refers to a point that may be a target point. That is, the predicted point is any point in the plane in which the arch curve lies. In other words, any point in the plane of the arch curve may be the target point.

Step S530, obtaining a third distance between each predicted point and a plurality of curve points.

In the embodiment of the present application, if the number of curve points is n and the number of predicted points is m, the calculation formula of the third distance between the kth predicted point and the ith curve point is as follows:

Wherein d _ik is the third distance between the kth predicted point and the ith curve point, (x _k,y_k) is the coordinate of the kth predicted point, and (x _i,y_i) is the coordinate of the ith curve point.

It is easy to understand that since the curve points have n, each predicted point can form n third distances from the n curve points. In a specific embodiment of the present application, as shown in fig. 9, if two predicted points (i.e., point D6 and point D7 as shown in fig. 9) are provided, and 5 curve points are selected on the dental arch curve, point D6 can form 5 third distances with the 5 curve points, and point D7 can also form 5 third distances with the 5 curve points.

And S540, acquiring variances corresponding to the predicted points one by one based on the third distances.

It should be clear that variance is a measure of the degree of dispersion between a set of data, i.e. the variance is used to measure the degree of deviation between individual data. That is, in the present embodiment, the variance between the plurality of third distances corresponding to each predicted point may be used to determine whether the predicted point has the smallest change in distance from each point on the dental arch curve. Of course, in other embodiments of the present application, the standard deviation, the range, the coefficient of variation, or other indicators may be used to determine whether the predicted point has the smallest change in distance from each point on the dental arch curve.

In the embodiment of the present application, based on a plurality of the third distances, a calculation formula for obtaining a variance corresponding to each predicted point one to one is as follows:

Wherein V _k is the variance of the third distances corresponding to the kth predicted point, n is the number of the third distances, d _i is the ith third distance corresponding to the kth predicted point, and d is the average value of the third distances corresponding to the kth predicted point.

Step S550, based on the variance, acquiring the target point from the plurality of predicted points.

It should be clear that in embodiments of the present application, it is difficult to precisely find the point (i.e., the optimal point) with the smallest change in distance from each point on the dental arch line in the plane in which the dental arch line lies. In most cases, only a point close to the optimal point can be found as the target point.

In an embodiment of the present application, the target point may be acquired from a plurality of predicted points in an arbitrary manner based on the variance of each predicted point. For example, the target point may be acquired in at least several ways as described below.

In one embodiment of the present application, as shown in fig. 9, we connect two ends of the dental arch curve 8, the surrounding area formed by the connection and the dental arch curve 8 is the central area 10, and the target point is located in the central area 10. Therefore, as shown in fig. 10, a lattice covering the central region 10 may be set, and the variance of each point in the lattice may be calculated, with the point with the smallest variance as the target point.

It is readily understood that in embodiments of the present application, the closer the points in the lattice are, the closer the acquired target point is to the optimal point. The more densely the dots in the lattice, the more computationally intensive. As can be seen from the foregoing, the target point is located in the central region 10, and in order to reduce the calculation amount in this embodiment, as shown in fig. 11, only the variance of the point located in the central region 10 in the lattice can be calculated.

It should be clear that, in order to ensure that the accuracy of the acquired target points is high enough (i.e. close to or equal to the optimal point), the number of points in the lattice needs to be set high enough (e.g. 1000 or 10000), that is to say that acquiring the target points by means of the lattice requires a large amount of computation. In order to reduce the amount of calculation for acquiring the target point, that is, to increase the speed at which the target point is found, in one embodiment of the present application, step S550 acquires the target point from the plurality of predicted points based on the variance, including steps S551 to S555.

Step S551 is to obtain a first predicted point, a second predicted point, and a third predicted point that are not collinear based on the plurality of predicted points.

In an embodiment of the application, the first, second and third predicted points may be any three non-collinear points in the plane of the dental arch line 8. For example, the first, second, and third predicted points may be three predicted points with the smallest variance among the predicted points in the dot matrix of the previous embodiment (the number of dots in the dot matrix may be small, several, ten, or several tens). Or the first, second and third predicted points may be the two endpoints and midpoints of the dental arch curve 8. In this embodiment, the magnitudes of the first variance, the second variance, and the third variance, which sequentially correspond to the first predicted point, the second predicted point, and the third predicted point, are increased. That is, among the first, second, and third predicted points, the third predicted point is the point farthest from the optimal point, and the first predicted point is the point closest to the optimal point.

Step S552 is to obtain a center point based on the first predicted point, the second predicted point and the third predicted point.

In the embodiment of the present application, the central point may be any point of an area surrounded by the connecting lines among the first predicted point, the second predicted point and the third predicted point. For example, in one embodiment of the present application, if the coordinates of the first predicted point are (x ₁,y₁), the coordinates of the second predicted point are (x ₂,y₂), and the coordinates of the third predicted point are (x ₃,y₃), the coordinates of the center point may be ((x ₁+x₂+x₃)/3,(y₁+y₂+y₃)/3).

Step S553, acquiring a reference point based on the center point and the third predicted point.

It should be clear that, among the first, second, and third predicted points, the third predicted point is the point farthest from the optimal point. That is, the first predicted point and the second predicted point are closer to the optimal point than the third predicted point. In other words, the third predicted point should be located in a direction approaching the first predicted point and the second predicted point to find the optimal point. Thus, in an embodiment of the application, the reference point may be any point distant from the center point in the first direction. In this embodiment, the first direction may be a specific direction among directions in which the third predicted point approaches the first predicted point and the second predicted point. For example, the first direction may be a direction from the third predicted point to the center point, or the first direction may be a direction from the third predicted point to a midpoint of a line connecting the first predicted point and the second predicted point.

In this embodiment, the purpose of obtaining the reference point is to find the optimal point. As can be seen from the foregoing, the reference point may be any point that is distant from the center point in the first direction. For example, as shown in fig. 12, it is assumed that the first predicted point is D8 point, the second predicted point is D9 point, the third predicted point is D10 point, the center point is D11 point, and the reference point is D12 point (i.e., any point distant from the center point in the first direction).

In the present embodiment, the reference point can be obtained by calculation by the following calculation formula. The formula is as follows:

D12=D11+α(D11-D10)

wherein D12 is the coordinate of the reference point, D11 is the coordinate of the center point, D10 is the coordinate of the third predicted point, and α is the first correction coefficient, which may be a constant value (e.g., 1 or 2) or a dynamically changing value (e.g., 2/number of updates of the third predicted point, see below).

Step S554, obtaining a fourth variance based on the reference point.

As can be seen from the foregoing, based on the reference point, the variance (i.e., the fourth variance) corresponding to the reference point can also be obtained by combining each curve point, which is not described herein.

Step S555, if the fourth square difference meets the first preset condition, the target point is obtained based on the first variance and the fourth variance, otherwise, the third predicted point is updated.

It should be clear that after the multiple loop iteration updating in step S552 and step S555, the target point close to the optimal point can be finally obtained. The present embodiment acquires the target point by a calculation method, which is higher in accuracy than the target point acquired by visual observation. In addition, the method for acquiring the target point provided by the embodiment only needs to iterate for ten times or several tens times (namely, only needs to calculate the variance for ten times or several tens times), and compared with the method for acquiring the target point through lattice calculation, the method of the embodiment can greatly reduce the calculated amount when searching the target point, namely, the speed of finding the target point is improved.

In an embodiment of the present application, the first preset condition may be any condition for stopping the iterative update. For example, the first preset condition includes that the number of updates of the third predicted point may be greater than a first preset value, and the first preset value may be any positive integer greater than 1. Or the absolute value of the difference between the fourth variance and the target variance is smaller than a second preset value. In this embodiment, the target variance may be a first variance, or the target variance may be an average of the first variance, the second variance, and the third variance. In this embodiment, the second preset value may be an empirical value obtained by multiple experiments.

In one embodiment of the present application, step S555 updates the third predicted point, including steps S556 to S558.

Step S556, if the fourth difference is smaller than the first variance, updating the third predicted point to be an arbitrary point far from the center point along the first direction.

It should be clear that if the fourth difference is smaller than the first variance, the reference point is closest to the optimal point among the first predicted point, the second predicted point, the third predicted point, and the reference point. In this embodiment, the reference point may be updated to a first predicted point of a next iteration, the first predicted point of the current iteration may be updated to a second predicted point of the next iteration, and the second predicted point of the current iteration may be updated to a third predicted point of the next iteration.

It should be clear that the reference point is closest to the optimal point due to the first, second, third and reference points. That is, the distance from the optimal point of each point along the first direction of the line connecting the center point and the reference point decreases. That is, we will designate a point of a unit length (may be any length) in the first direction, which is located next to the reference point as the first point, and the first point is likely to be closer to the optimum point with respect to the reference point. In order to be able to increase the speed approaching the optimal point, in one embodiment of the application, the first, second and third predicted points of the next iteration may be updated to the first, second and replacement points of the present iteration. The coordinates of the replacement point may be d12+β (D12-D11), where D12 is the coordinates of the reference point, D11 is the coordinates of the center point, and β is a second correction coefficient, similar to the first correction coefficient, which may be a constant value (e.g., 1 or 2) or a dynamically variable value, which is not described herein.

It should be clear that if the second correction coefficient is 2, the replacement point can be located outside the range formed by the first prediction point, the second prediction point, and the third prediction point, that is, the target point acquired later can be prevented from being trapped into the local optimum.

Step S557, if the fourth square difference is greater than the first variance and smaller than the third variance, updating the third predicted point to the reference point.

It should be clear that if the fourth difference is greater than the first variance and less than the third variance, it is stated that the optimal point is likely to be near the area formed by the first predicted point, the second predicted point, and the reference point. The third predicted point for the next iteration can be updated to the reference point.

And S558, if the fourth square difference is greater than the third variance, updating the third predicted point to be any point on the connecting line between the central line point and the third predicted point.

It is clear that if the fourth difference is larger than the third variance, it is explained that the third predicted point is closer to the optimal point than the reference point. That is, the optimal point is likely to be near the line connecting the third predicted point and the center point. In this embodiment, the center point may be used to replace the third predicted point, so as to perform the next iteration update. Or in another embodiment of the present application, the third predicted point may be updated to d11+θ (D10-D11), where D11 is the coordinate of the center point, D10 is the coordinate of the third predicted point, and θ is a third correction coefficient, which, similar to the first correction coefficient and the second correction coefficient, may be a constant value (e.g., 0.5) or a dynamically changing value, which is not described herein.

And step S600, adjusting the position of the first axis so that the first axis passes through the target point.

It should be clear that adjusting the position of the first axis (i.e. adjusting the rotation center position of the horizontal boom 1) is a mature technique, and will not be described here.

In a specific embodiment of the application, the curve of the X-ray source movement in the horizontal boom 1 in the first direction during the whole scanning exposure is shown in fig. 12. Wherein, the ordinate is the relative position of the X-ray source and the horizontal boom 1 along the first direction, and the abscissa is time.

The present embodiment can minimize the motion amplitude, i.e. the motion inertia generated by the motion of the X-ray source and the X-ray sensor during the subsequent motion of the X-ray source and the X-ray sensor, by finding the target point close to the optimal point.

Having described embodiments of the method for reconstructing an oral panorama in accordance with the present application, an embodiment of an X-ray imaging system in accordance with the present application is described below, as shown in fig. 1, and comprises:

A horizontal boom 1, the horizontal boom 1 being capable of central rotation about a first axis, the first axis being parallel to the vertical direction;

the X-ray source 2 and the X-ray sensor 3 are arranged at the first end of the horizontal boom 1, and the X-ray sensor 3 is arranged at the second end of the horizontal boom 1;

a reader 4 for acquiring a dental arch curve of a user;

A processor 5 for acquiring a plurality of sampling points based on the dental arch curve;

A controller 6 for controlling the rotation of the horizontal boom, the positions of the X-ray source and the X-ray sensor based on the plurality of sampling points, and obtaining perspective views corresponding to the sampling points one by one;

the processor 5 is further configured to obtain an oral panorama based on the plurality of perspectives.

As a specific embodiment of the present application, the reader 4 is further configured to obtain a scan step angle, where the scan step angle is preset;

the processor 5 is further configured to obtain a total scan angle based on the dental arch curve and a target point, where the target point is an intersection point formed by the first axis and a plane in which the dental arch curve is located;

As a specific embodiment of the present application, the reader 4 is further configured to obtain a current sampling point and a historical sampling point based on the plurality of sampling points, where the current sampling point and the historical sampling point are adjacent sampling points;

The processor 5 is further configured to obtain a first distance based on the current sampling point and the target point;

The controller 6 is also configured to adjust the positions of the X-ray source and the X-ray sensor based on the adjustment distance during a time period in which the horizontal boom 1 is rotated from the historical sampling point to a current sampling point.

As a specific embodiment of the present application, the processor 5 is further configured to obtain a target point based on the dental arch curve, where the target point includes a point with a minimum change in distance from each point on the dental arch curve in a plane in which the dental arch curve is located;

The controller 6 is also adapted to adjust the position of the first axis such that the first axis passes through the target point.

As a specific embodiment of the present application, the processor 5 is further configured to obtain a plurality of curve points based on the dental arch curve, where the curve points are any points in the dental arch curve;

The processor 5 is further configured to obtain a first predicted point, a second predicted point, and a third predicted point that are not collinear, where the first predicted point, the second predicted point, and the third predicted point are three predicted points with a smallest variance among the plurality of predicted points, and the first variance, the second variance, and the third variance that correspond to the first predicted point, the second predicted point, and the third predicted point in sequence are increased;

And, based on the reference point, obtaining a fourth difference;

As a specific embodiment of the present application, the processor 5 is further configured to update the third predicted point to an arbitrary point far from the center point along the first direction if the fourth difference is smaller than the first variance;

As a specific embodiment of the application, the first preset condition comprises that the number of times of updating the third predicted point is larger than a first preset value, or that the absolute value of the difference between the fourth variance and a target variance is smaller than a second preset value, and the target variance comprises the first variance or the average value of the first variance, the second variance and the third variance.

As a specific embodiment of the present application, the reader 4 is further configured to obtain a selected number of the curve points, where the selected number is preset;

the processor 5 is further configured to randomly acquire a number of curve points equal to the number selected based on the dental arch curve;

or the plurality of curve points comprise two end points of the dental arch curve, the reader 4 is further used for acquiring the selected number of the curve points, and the selected number is preset;

The processor 5 is further configured to obtain a plurality of curve points based on the dental arch curve and the selected number, where the distances between adjacent curve points are equal.

It should be apparent that computer-readable storage media of the present application, including both permanent and non-permanent, removable and non-removable media, may be used to implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of storage media for a computer include, but are not limited to, phase change memory (PRAM), static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium, which can be used to store information that can be accessed by a computing device. Computer-readable media, as defined herein, does not include transitory computer-readable media (trans itorymed ia), such as modulated data signals and carrier waves.

In the foregoing embodiments, the descriptions of the embodiments are emphasized, and for parts of one embodiment that are not described in detail, reference may be made to related descriptions of other embodiments.

It will be clearly understood by those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described method, apparatus and device may refer to corresponding procedures in the foregoing method embodiments, which are not repeated herein.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus, device and method may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, and for example, the division of the modules is merely a logical function division, and there may be additional divisions when actually implemented, for example, multiple modules or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or modules, which may be in electrical, mechanical, or other forms.

The modules described as separate components may or may not be physically separate, and components shown as modules may or may not be physical modules, i.e., may be located in one place, or may be distributed over a plurality of network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional module in each embodiment of the present application may be integrated into one processing module, or each module may exist alone physically, or two or more modules may be integrated into one module. The integrated modules may be implemented in hardware or in software functional modules. The integrated modules, if implemented in the form of software functional modules and sold or used as a stand-alone product, may be stored in a computer readable storage medium.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product.

The computer program product includes one or more computer instructions. When the computer program is loaded and executed on a computer, the flow or functions according to the embodiments of the present application are fully or partially produced. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by a wired (e.g., coaxial cable, fiber optic, digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer readable storage medium may be any available medium that can be stored by a computer or a data storage device such as a server, data center, etc. that contains an integration of one or more available media. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid state disk SolidStateDisk (SSD)), etc.

Although embodiments of the present application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the application, the scope of which is defined in the appended claims and their equivalents.

Claims

1. A method for reconstructing an oral panoramic image, applied to an X-ray imaging system, characterized in that the X-ray imaging system comprises a horizontal suspension arm (1), an X-ray source (2) arranged at a first end of the horizontal suspension arm (1), and an X-ray sensor (3) arranged at a second end of the horizontal suspension arm; the X-ray source (2) and the X-ray sensor (3) are both capable of moving along the length direction of the horizontal suspension arm (1); the horizontal suspension arm (1) is capable of central rotation around a first axis, and the first axis is parallel to the vertical direction; the method for reconstructing an oral panoramic image comprises:

Get the user's dental arch curve;

Based on the dental arch curve, obtaining multiple sampling points;

Based on the multiple sampling points, the rotation of the horizontal boom (1), the positions of the X-ray source (2) and the X-ray sensor (3) are controlled to obtain perspective views corresponding to each sampling point;

Get a panoramic view of the oral cavity based on multiple perspective views.

2. The oral panoramic image reconstruction method according to claim 1, characterized in that the step of obtaining a plurality of sampling points based on the dental arch curve comprises:

Acquiring a scanning step angle; wherein the scanning step angle is preset;

Based on the dental arch curve and the target point, a total scanning angle is acquired; the target point is an intersection point formed by the first axis and the plane where the dental arch curve is located;

A plurality of sampling points are acquired based on the scanning step angle and the total scanning angle.

3. The oral panoramic image reconstruction method according to claim 2, characterized in that the control of the rotation of the horizontal suspension arm (1), the positions of the X-ray source (2) and the X-ray sensor (3) based on the multiple sampling points comprises:

Based on the multiple sampling points, a current sampling point and a historical sampling point are acquired; the current sampling point and the historical sampling point are adjacent sampling points;

Based on the current sampling point and the target point, acquiring a first distance;

Based on the historical sampling points and the target point, acquiring a second distance;

Based on the first distance and the second distance, acquiring an adjusted distance;

During the time period when the horizontal boom (1) rotates from the historical sampling point to the current sampling point, the positions of the X-ray source and the X-ray sensor are adjusted based on the adjustment distance.

4. The oral panoramic image reconstruction method according to any one of claims 1 to 3, characterized in that after obtaining the dental arch curve of the user, the method further comprises:

Based on the dental arch curve, a target point is obtained; the target point includes a point in the plane where the dental arch curve is located, which has the smallest distance change from each point on the dental arch curve;

5. The oral panoramic image reconstruction method according to claim 4, characterized in that the step of obtaining the target point based on the dental arch curve comprises:

Based on the dental arch curve, a plurality of curve points are obtained; the curve points are any points in the dental arch curve;

Based on the dental arch curve, a plurality of prediction points are obtained; the prediction points are any points in the plane where the dental arch curve is located;

Obtaining the third distance between each predicted point and the plurality of curve points;

Based on the plurality of third distances, obtaining a variance corresponding to each prediction point one by one;

Based on the variance, the target point is obtained from the multiple predicted points.

6. The oral panoramic image reconstruction method according to claim 5, characterized in that the step of obtaining the target point from the plurality of predicted points based on the variance comprises:

Based on the multiple prediction points, a first prediction point, a second prediction point, and a third prediction point that are not collinear are obtained; the first prediction point, the second prediction point, and the third prediction point are three prediction points with the smallest variance among the multiple prediction points; and the first variance, the second variance, and the third variance corresponding to the first prediction point, the second prediction point, and the third prediction point are increased in size;

Acquire a center point based on the first prediction point, the second prediction point, and the third prediction point;

Based on the center point and the third predicted point, a reference point is obtained; the reference point is any point away from the center point along a first direction; the first direction is from the third predicted point to the center point;

Based on the reference point, obtaining a fourth variance;

If the fourth variance satisfies the first preset condition, the target point is acquired based on the first variance and the fourth variance; otherwise, the third prediction point is updated.

7. The oral panoramic image reconstruction method according to claim 6, wherein updating the third prediction point comprises:

If the fourth variance is smaller than the first variance, the third prediction point is updated to an arbitrary point away from the center point along the first direction;

If the fourth variance is greater than the first variance and less than the third variance, the third prediction point is updated as the reference point;

If the fourth variance is greater than the third variance, the third prediction point is updated to be any point on the line between the center point and the third prediction point.

8. The oral panoramic image reconstruction method according to claim 6 is characterized in that the first preset condition includes: the update number of the third prediction point is greater than the first preset value; or the absolute value of the difference between the fourth variance and the target variance is less than the second preset value; the target variance includes the first variance or the average value of the first variance, the second variance and the third variance.

9. The oral panoramic image reconstruction method according to claim 5, characterized in that the step of obtaining a plurality of curve points based on the dental arch curve comprises:

Obtaining the number of selected curve points; the number of selected points is preset;

Based on the dental arch curve, randomly obtaining a plurality of curve points of the same number as the selected number;

Alternatively, the multiple curve points include two end points of the dental arch curve; and the acquiring multiple curve points based on the dental arch curve includes:

Based on the dental arch curve and the selected number, a plurality of curve points are obtained; and the intervals between adjacent curve points are equal.

10. An X-ray imaging system, comprising:

A horizontal boom (1), wherein the horizontal boom (1) is capable of central rotation around a first axis, wherein the first axis is parallel to the vertical direction;

An X-ray source (2) and an X-ray sensor (3); the X-ray source (2) is arranged at a first end of the horizontal suspension arm (1), and the X-ray sensor (3) is arranged at a second end of the horizontal suspension arm (1); the X-ray source and the X-ray sensor are both movable along the length direction of the horizontal suspension arm;

A reader (4) for obtaining a dental arch curve of a user;

A processor (5) is used to obtain a plurality of sampling points based on the dental arch curve;

A controller (6) is used to control the rotation of the horizontal boom, the positions of the X-ray source and the X-ray sensor based on the multiple sampling points, and obtain a perspective view corresponding to each sampling point;

The processor (5) is also used to obtain a panoramic image of the oral cavity based on multiple perspective images.