Disclosure of Invention
The present invention aims to solve at least one of the technical problems in the related art to some extent. Therefore, an object of the present invention is to provide a positioning system for radiotherapy, which improves the accuracy of positioning proton heavy ion treatment without affecting the treatment rate and the treatment effect.
In order to achieve the above purpose, an embodiment of the first aspect of the present invention provides a positioning system for radiotherapy, the system comprising a bed board, a mechanical arm, an optical tracker, and a positioning control device, wherein a measuring tool is installed on the bed board, a marking ball is installed on the measuring tool, the mechanical arm is connected with the bed board and used for adjusting the position of the bed board, the optical tracker is used for measuring the position coordinates of the marking ball in real time, and the positioning control device is respectively connected with the mechanical arm and the optical tracker and used for obtaining the position deviation and the attitude angle deviation of the mechanical arm according to the position coordinates of the marking ball, and correcting the positioning of the bed board through the mechanical arm according to the position deviation and the attitude angle deviation.
According to one embodiment of the invention, the measuring tool is further provided with a laser tracker target ball, the positioning control device is further used for acquiring the position coordinates of the laser tracker target ball through a laser tracker when the mechanical arm is at the original point positions under different treatment postures, obtaining the theoretical position coordinates of the marker ball according to the position coordinates of the laser tracker target ball and the relative positions of the laser tracker target ball and the marker ball, and carrying out error calibration on the optical tracker according to the theoretical position coordinates of the marker ball and the position coordinates of the marker ball measured by the optical tracker, wherein the positioning control device is further used for correcting the position coordinates of the marker ball according to the calibration errors of the optical tracker before obtaining the position deviations and the posture angle deviations of all joints of the mechanical arm according to the position coordinates of the marker ball.
According to one embodiment of the invention, the positioning control device is specifically used for acquiring a mapping relation among a world coordinate system, a mechanical arm coordinate system and an optical tracker coordinate system when the position deviation and the attitude angle deviation of the mechanical arm are obtained according to the position coordinates of the marking ball, obtaining the actual position and the actual attitude angle of the mechanical arm according to the mapping relation and the position coordinates of the marking ball, obtaining the position deviation according to the actual position and the theoretical position of the mechanical arm, and obtaining the attitude angle deviation according to the actual attitude angle and the theoretical attitude angle of the mechanical arm, wherein the mapping relation is established according to the position relation among the marking ball, the mechanical arm and the optical tracker.
Further, the mapping relationship is represented by the following formula:
Wherein W3 is the optical tracker coordinate system, W2 is the mechanical arm coordinate system, W1 is the world coordinate system,AndThe rotation matrix for W3 relative to W2 and the transformation matrix for W2 relative to W1, respectively.
According to one embodiment of the invention, when the swing control device corrects the swing of the bed plate through the mechanical arm according to the position deviation and the attitude angle deviation, the swing control device is specifically used for correcting the swing of the bed plate by adjusting the movement of the corresponding joint according to the movement deviation through an inverse solution algorithm when the position deviation exceeds a first set threshold and the attitude angle deviation exceeds a second set threshold.
Further, when the swing control device corrects the swing of the bed board through the mechanical arm according to the position deviation and the posture angle deviation, the swing control device is specifically used for dividing the motion track of the mechanical arm into N sections, predicting the position deviation and the posture angle deviation corresponding to the i+1th section motion track according to the position deviation and the posture angle deviation corresponding to the i+1th section motion track at the time of i xS, and correcting the motion of the mechanical arm in the i+1th section according to the predicted position deviation and the posture angle deviation corresponding to the i+TS, wherein N=T/TS, T is a correction period, and TS is a period of measurement and data feedback of the optical tracker.
According to one embodiment of the invention, the positioning control device is further used for obtaining the running speed of the mechanical arm according to the position coordinates of the marking ball measured in real time, and controlling the mechanical arm to stop immediately when the running speed is smaller than the theoretical speed and the difference value exceeds a third set threshold value.
According to one embodiment of the invention, the positioning control device is further used for storing theoretical data and measurement data of the mechanical arm under different treatment postures, obtaining a database file and upgrading control parameters of the mechanical arm according to the database file.
According to one embodiment of the invention, the measuring tool comprises a first component and a second component, wherein the first component is used for installing the laser tracker target ball, the second component is used for installing the marking ball, the first component and the second component are independently arranged and can be detached, and the laser tracker target ball and the marking ball can be detached and installed.
According to one embodiment of the invention, the positioning control device is connected in wired communication with the optical tracker.
According to the positioning system for radiotherapy, provided by the embodiment of the invention, the accuracy of proton heavy ion treatment positioning is improved on the basis of not affecting the treatment rate and the treatment effect.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Detailed Description
Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present invention and should not be construed as limiting the invention.
The positioning system for radiation therapy according to the embodiments of the present invention will be described in detail with reference to fig. 1 to 3 and the detailed description.
Fig. 1 is a schematic structural view of a positioning system for radiotherapy according to an embodiment of the present invention. As shown in fig. 1, the radiotherapy positioning system 100 includes a couch 10, a robot arm 20, an optical tracker 30, and a positioning control device 40. Referring to fig. 2-3, a measuring tool 11 is installed on a bed board 10, a marking ball 1 is installed on the measuring tool 11, a mechanical arm 20 is connected with the bed board 10 and used for adjusting the position of the bed board 10, and an optical tracker 30 is used for measuring the position coordinates of the marking ball 1 in real time.
In this embodiment, the positioning control device 40 is connected to the mechanical arm 20 and the optical tracker 30, respectively, and is configured to obtain a position deviation and an attitude angle deviation of the mechanical arm 20 according to the position coordinates of the marker ball 1, and correct the positioning of the bed board 10 by the mechanical arm 20 according to the position deviation and the attitude angle deviation.
Specifically, the position of the mechanical arm 20 may be obtained by a laser tracker, but since the laser tracker can only obtain the position of the mechanical arm 20 when the mechanical arm 20 is stopped, the laser tracker cannot achieve the purpose of tracking the mechanical arm 20 in real time. In the invention, the positioning control device 40 measures the position coordinates of the marking ball 1 in real time through the optical tracker 30, and then obtains the position of the mechanical arm 20 according to the position coordinates of the marking ball 1, so that the purpose of tracking the mechanical arm 20 in real time can be achieved. Further, the positioning control device 40 obtains the positional deviation and the attitude angle deviation of the arm 20 from the position coordinates of the marker ball 1, and corrects the positioning of the bed board 10 by the arm 20 based on the positional deviation and the attitude angle deviation.
The positioning control device 40 is connected to the optical tracker 30 by wired communication. Specifically, the optical tracker 30 and the positioning control device 40 establish a communication connection through a network cable, so that data of the optical tracker 30 can be rapidly transmitted to the positioning control device 40.
Therefore, the positioning system for radiotherapy can ensure the precision of treatment positioning and treatment, and reduce the influence of position deviation and deformation caused by the weight of a patient and mechanical position deviation of the positioning system on the precision.
As an example, as shown in fig. 3, the measuring tool 11 is further provided with a laser tracker target ball 2. The positioning control device 40 is further configured to obtain, by using the laser tracker, a position coordinate of the target ball 2 of the laser tracker when the mechanical arm 20 is at an origin position under different treatment postures, obtain a theoretical position coordinate of the marker ball 1 according to the position coordinate of the target ball 2 of the laser tracker and a relative position of the target ball 2 of the laser tracker and the marker ball 1, and perform error calibration on the optical tracker 30 according to the theoretical position coordinate of the marker ball 1 and the position coordinate of the marker ball 1 measured by the optical tracker 30.
The measurement tool 11 may include a first component 111 and a second component 112, where the first component 111 is used for installing a target ball of a laser tracker, the second component 112 is used for installing a marking ball 1, and the first component 111 and the second component 112 are independently arranged and are detachable, and the target ball 2 of the laser tracker and the marking ball 1 are detachably installed.
The positioning control device 40 is also used for correcting the position coordinates of the marker ball 1 according to the calibration error of the optical tracker 30 before obtaining the position deviation and the attitude angle deviation of each joint of the mechanical arm 20 according to the position coordinates of the marker ball 1.
Further, the positioning control device 40 is specifically configured to obtain a mapping relationship among the world coordinate system, the mechanical arm coordinate system, and the optical tracker coordinate system when obtaining the position deviation and the attitude angle deviation of the mechanical arm 20 according to the position coordinates of the marker ball 1, obtain an actual position and an actual attitude angle of the mechanical arm 20 according to the mapping relationship and the position coordinates of the marker ball 1, obtain a position deviation according to the actual position and the theoretical position of the mechanical arm 20, and obtain an attitude angle deviation according to the actual attitude angle and the theoretical attitude angle of the mechanical arm 20, wherein the mapping relationship is established according to the position relationship among the marker ball 1, the mechanical arm 20, and the optical tracker 30.
Specifically, the mapping relationship is expressed by the formulaWherein W3 is an optical tracker coordinate system, W2 is a mechanical arm coordinate system, W1 is a world coordinate system,AndThe rotation matrix of W3 relative to W2 and the conversion matrix of W2 relative to W1 are respectively adopted, so that the actual position (X0,Y0,Z0) and the actual attitude angle (RX0,RY0,RZ0) of the mechanical arm 20 are obtained according to the mapping relation and the position coordinate of the marking ball 1, the position deviation (delta X0,ΔY0,ΔZ0) is obtained according to the actual position (X0,Y0,Z0) of the mechanical arm 20 and the theoretical position (X0′,Y0′,Z0 ') of the mechanical arm 20, and the attitude angle deviation (delta RX0,ΔRY0,ΔRZ0) is obtained according to the actual attitude angle (RX0,RY0,RZ0) of the mechanical arm 20 and the theoretical attitude angle (RX0′,RY0′,RZ0') of the mechanical arm 20, wherein ,ΔX0＝X0-X0′,ΔY0＝Y0-Y0′,ΔZ0＝Z0-Z0′;ΔRX0＝RX0-RX0′,ΔRY0＝RY0-RY0′,ΔRZ0＝RZ0-RZ0′.
Thus, the positioning control device 40 obtains a positional deviation from the actual position and the theoretical position of the robot arm 20, and obtains a posture angle deviation from the actual posture angle and the theoretical posture angle of the robot arm 20.
Further, the positioning control device 40 is specifically configured to correct the positioning of the bed board 10 by adjusting the movement of the corresponding joint according to the movement deviation when the position deviation exceeds a first set threshold and the posture angle deviation exceeds a second set threshold by obtaining the movement deviation of each joint of the mechanical arm 20 according to the position deviation and the posture angle deviation by an inverse solution algorithm when the positioning of the bed board 10 is corrected by the mechanical arm 20 according to the position deviation and the posture angle deviation.
Specifically, when the position deviation exceeds the first set threshold and the posture angle deviation exceeds the second set threshold, the positioning control device 40 obtains the motion deviation of each joint of the mechanical arm 20 according to the position deviation and the posture angle deviation through an inverse solution algorithm, further divides the motion track of the mechanical arm 20 into N segments, predicts the position deviation and the posture angle deviation corresponding to the i+1th segment motion track according to the position deviation and the posture angle deviation corresponding to the i+1th segment motion track at the i×S time, and corrects the motion of the mechanical arm 20 in the i+1th segment according to the position deviation and the posture angle deviation corresponding to the predicted i+1th segment motion track, where n=t/TS, T is a correction period, and TS is a period of measurement and data feedback of the optical tracker 30.
Therefore, the deviation correction motion range is reduced, the position deviation and the posture angle deviation on the motion track are corrected in real time, and the position and the posture on the motion track are accurate.
As an example, the positioning control device 40 is further configured to obtain the running speed of the mechanical arm 20 according to the position coordinates of the marker ball 1 measured in real time, and control the mechanical arm 20 to stop immediately when the running speed is less than the theoretical speed and the difference exceeds the third set threshold.
Specifically, in the case of a collision, a system failure, or the like of the positioning system for radiation therapy, there may be a lag or error in the operation speed of the robot arm 20, and therefore, the positioning control device 40 obtains the operation speed of the robot arm 20 according to the position coordinates of the marker ball 1 measured in real time by the optical tracker 30, and controls the robot arm 20 to stop immediately when the operation speed is less than the theoretical speed and the difference exceeds the third set threshold.
Thus, when the positioning system for radiation therapy collides, system failure, or the like, the control robot 20 is immediately stopped, thereby preventing loss.
As an example, the positioning control device 40 is further configured to store theoretical data and measurement data of the robotic arm 20 under different treatment postures, obtain a database file, and upgrade control parameters of the robotic arm 20 according to the database file.
Specifically, the positioning control device 40 stores the origin positions of the mechanical arm 20 in different treatment postures, and the actual positions, the actual posture angles and the running speeds of the mechanical arm 20 obtain database files. And upgrades the control parameters of the robot arm 20 according to the database file. It should be noted that the database file may also be used by the same type of equipment.
In summary, in the positioning system for radiotherapy, the position deviation and the posture angle deviation of the mechanical arm are obtained according to the position coordinates of the marker balls, and the positioning of the bed plate is corrected by the mechanical arm according to the position deviation and the posture angle deviation, so that the influence of the position deviation and the deformation caused by the weight of a patient and the mechanical position deviation of the positioning system for radiotherapy on the precision can be reduced, and the precision of the positioning of proton heavy ion treatment can be improved on the basis of not affecting the treatment rate and the treatment effect.
In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means 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 present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.
In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed, mechanically connected, electrically connected, directly connected, indirectly connected through an intervening medium, or in communication between two elements or in an interaction relationship between two elements, unless otherwise explicitly specified. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
In the present invention, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.
While embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and not to be construed as limiting the invention, and that variations, modifications, alternatives and variations may be made to the above embodiments by one of ordinary skill in the art within the scope of the invention.