Radiotherapy apparatus and alignment method thereof

Abstract

Provided in the present invention are a radiotherapy apparatus and an alignment method thereof. The radiotherapy apparatus comprises: a treatment device, which is used for generating a treatment beam; a driving device, which is used for driving the treatment device to move; a beam-limiting device, the beam-limiting device being provided with a beam channel, the treatment beam passing through the beam channel and then irradiating a focus in a patient; a pulling device, which is used for bearing a pulling force and a pulling torque applied by a user, so as to pull the treatment device to move, the pulling device comprising a measurement component, and the measurement component being used for measuring the pulling force and torque applied to the pulling device; a positioning assembly, the positioning assembly comprising marking components and a photographing device, there being at least three marking components, the marking components being fixedly arranged on the beam-limiting device, and the photographing device being used for shooting the marking components; and a control module, the control module being separately in signal connection with the treatment device, the driving device, the pulling device and the photographing device. The radiotherapy apparatus of the present invention solves the technical problem in the prior art that aligning treatment heads of radiotherapy apparatuses with tumor tissue is time-consuming and laborious and thus causes a low treatment efficiency.

Description

A radiotherapy device and its alignment method Technical Field

[0001] This invention relates to the field of radiotherapy equipment technology, and specifically to a radiotherapy device and its alignment method. Background Technology

[0002] Radiation therapy is a method of killing tumor tissue using radiation. It is a local treatment and one of the three major treatment methods for cancer. Intraoperative radiotherapy, simply put, is radiation therapy or dose irradiation performed under conditions that are visible to the naked eye or perceptible to the touch, minimizing damage to normal tissues. However, current clinical intraoperative radiotherapy equipment requires irradiation lasting several minutes or tens of minutes, and prolonged tissue exposure carries a high risk of infection. When the radiation dose rate exceeds a certain threshold, such as 40 Gy / s, ultra-high dose rates of radiation possess a biological effect that can reduce damage to normal tissues while maintaining tumor-killing effects; this effect is called the Flash effect. Combining intraoperative radiotherapy with the Flash effect can shorten the dose irradiation time from several minutes or tens of minutes to the millisecond or microsecond level. This not only significantly reduces tissue exposure time and lowers the risk of infection but also effectively protects normal tissues, and significantly improves the overall efficiency of radiotherapy.

[0003] However, in order to achieve high-energy rays with ultra-high dose rates, current treatment heads, including those with electron linear accelerators, are large and heavy. Aiming a treatment head weighing hundreds of kilograms at the tumor tissue is not only time-consuming and laborious, but also easily negates the millisecond or μs-level treatment efficiency of Flash radiotherapy. Moreover, the alignment accuracy is not high, and the radiotherapy effect cannot be guaranteed.

[0004] Therefore, there is an urgent need to develop an intraoperative radiotherapy device that is lightweight, fast, intelligent, precise, and compatible with Flash therapy, so as to achieve safe and efficient Flash intraoperative radiotherapy. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a radiotherapy device and its alignment method to solve the technical problem that the time-consuming and laborious process of aligning the treatment head of the radiotherapy device with the tumor tissue leads to low treatment efficiency in related technologies.

[0006] To achieve the above-mentioned technical objectives, the present invention adopts the following technical solution: A radiotherapy device is provided, comprising: a treatment device for generating a treatment beam; a driving device for driving the treatment device to move; a beam-limiting device having a beam channel through which the treatment beam irradiates the patient's lesion; a traction device for bearing the traction force and traction torque applied by the user to traction the treatment device, the traction device including a measuring component for measuring the traction force and torque applied to the traction device; and a positioning assembly including a marking component and an imaging device, the marking component comprising at least three marking components fixedly disposed on the beam-limiting device. The device includes an imaging device for imaging the marked component; a control module connected to the treatment device, drive device, traction device, and imaging device, and configured to: calculate the desired pose of the treatment device in Cartesian space based on the traction force and torque applied to the traction device; control the treatment device to move to a first target pose based on the desired pose in Cartesian space to obtain a current image of the marked component; obtain the current pose of the beam limiting device based on the current image of the marked component; and control the treatment device to move to a second target pose based on the current pose of the beam limiting device to align the treatment beam with the beam channel.

[0007] Furthermore, the treatment device includes a housing and a beam outlet installed inside the housing. The beam outlet has a beam outlet on the side of the beam outlet near the beam confinement device and is used to release the treatment beam.

[0008] Furthermore, the treatment device is also equipped with a beam monitoring device for measuring the parameters of the treatment beam.

[0009] Furthermore, the traction device includes a traction handle located on the housing near the outlet; the traction handle includes: a first connecting portion fixedly connected to the measuring component; a second connecting portion, one end of which is connected to the end of the first connecting portion away from the housing, and the other end of which extends in a direction away from the driving device, and a gripping space for accommodating a person's hand is formed between the second connecting portion and the treatment device.

[0010] Furthermore, the measuring component includes a six-dimensional force sensor, which is fixedly connected to the housing.

[0011] Furthermore, the beam limiting device includes a beam limiting device body and a mounting plate that are connected to each other. The beam limiting device body has a beam channel, and the mounting plate has a marking component installed on the side near the treatment device.

[0012] Furthermore, the shooting device includes a light source, and the surface of the marking component is provided with a reflective layer, the marking component being used to reflect the light emitted by the light source.

[0013] Furthermore, the shooting device includes at least two cameras spaced apart for simultaneously shooting the marked component.

[0014] Furthermore, at least three marking components are spaced apart from each other and are not collinearly arranged on the beam-limiting device; the distance between any two marking components is ≥50mm; and the difference in distance between any two different marking components is ≥3mm.

[0015] Furthermore, the radiotherapy equipment includes: a base, which is movably mounted, and a drive unit fixedly mounted on the base; a power source module, which is spaced apart from the drive unit on the base, and is connected to the treatment device to provide radio frequency signals to the treatment device; the power source module also includes an energy storage component for supplying power to the treatment device; and a control console, which includes control function keys and a human-machine interface, and is signal-connected to the control module to enable remote control of the control module.

[0016] Furthermore, the base is equipped with multiple wheels and a battery for driving the wheels to move the radiotherapy equipment; the base also includes a locking mechanism for restricting the movement of the wheels. The locking mechanism is connected to the control module and is configured to: acquire the movement status of the drive device, and if the drive device is in motion, open the locking mechanism.

[0017] Furthermore, the radiotherapy equipment includes: a beam-limiting stent for fixing the beam-limiting device; a beam modulator connected to the end of the beam-limiting device away from the treatment device, for modulating the dose distribution in the lesion area; and a beam blocking plate positioned opposite to the treatment beam for blocking the treatment beam from passing through the beam blocking plate.

[0018] Furthermore, the treatment device is configured to emit an ionizing radiation dose of at least 25 Gy within a time of less than 0.1 s.

[0019] A method for aligning a radiotherapy device, applicable to the aforementioned radiotherapy device, includes: acquiring a treatment plan; the treatment device entering an alignment preparation state; calculating the desired pose of the treatment device in Cartesian space based on the traction force and torque applied to the traction device; controlling the treatment device to move to a first target pose based on the desired pose in Cartesian space to acquire a current image of a marker component; acquiring the current pose of a beam-limiting device based on the current image of the marker component; and controlling the treatment device to move to a second target pose based on the current pose of the beam-limiting device to align the treatment beam with the beam channel.

[0020] Further, the method for calculating the desired pose of the treatment device in Cartesian space based on the traction force and torque applied to the traction device, and controlling the treatment device to move to the first target pose based on the desired pose of the treatment device in Cartesian space to obtain the current image of the marked component includes: calculating the first traction force and the first traction torque of the force sensing point based on the traction force and torque applied to the traction device; constructing the admittance relationship of the first traction force and the first traction torque in the coordinate system of the treatment device, respectively, and calculating the desired pose of the treatment device in Cartesian space; obtaining the traction mode selection signal input by the user, selecting the corresponding preset traction mode according to the traction mode selection signal input by the user, adjusting the desired pose according to the selected preset traction mode and a preset method; performing inverse kinematics calculation based on the adjusted desired pose to obtain the movement trajectory of the driving device, and controlling the treatment device to move to the first target pose to obtain the current image of the marked component.

[0021] Furthermore, the method of obtaining the current pose of the beam limiting device based on the current image of the marked component and controlling the treatment device to move to the second target pose based on the current pose of the beam limiting device includes: obtaining the desired pose of the driving device based on the current pose of the beam limiting device and controlling the treatment device to move to the second target pose based on the desired pose of the driving device.

[0022] Furthermore, the method of controlling the treatment device to move to the first target pose to obtain the current image of the marked component includes: determining whether the treatment device has reached the first target pose; including: determining whether the number of marked components in the current image is greater than or equal to a first preset threshold; if the number of marked components is greater than or equal to the first preset threshold, then determining the force condition of the traction device; if the traction force and torque applied to the traction device are zero, then the treatment device has reached the first target pose.

[0023] Furthermore, the method of controlling the treatment device to move to the second target pose according to the desired pose of the driving device includes: determining whether the treatment device has reached the second target pose; including: determining whether the difference between the current pose of the treatment device relative to the beam limiting device and the desired pose is less than or equal to a second preset threshold. If the difference between the current pose of the treatment device relative to the beam limiting device and the desired pose is less than or equal to the second preset threshold, then the treatment device has reached the second target pose and the alignment of the treatment beam with the beam limiting device is completed. Beneficial effects: 1. The alignment process between the treatment device and the beam limiting device is configured in two stages: first, coarse alignment is achieved through compliant traction, and then fine alignment is achieved through visual guidance. This avoids the spatial limitations and operational uncertainties that exist between the human eye and the components to be aligned when only manual alignment is used. It ensures the precise alignment of the treatment beam and the beam channel, ensuring the safety of the Flash treatment process. This achieves a fast, convenient, intelligent, and precise alignment process for radiotherapy equipment. It not only ensures the safety of the radiotherapy process but is also the key to the efficient utilization of the Flash effect. It solves the technical problem of low treatment efficiency caused by the time-consuming and laborious process of aligning the treatment head of radiotherapy equipment with tumor tissue in related technologies.

[0024] 2. By setting up a traction device, measuring the magnitude of the traction force and torque on the traction device, and constructing the admittance relationship between the force and torque at the point of application of the traction force and the end pose of the treatment device, the intention of traction is calculated, and a new desired end pose command for the radiotherapy head is generated. This allows the drive device to move in accordance with the dragging force of the human hand. When the control module can obtain the current image of the marker component 5 according to certain rules, the conditions for completing compliant traction are met. The treatment device 1 moves to the first target pose, the coarse alignment process is completed, and the next stage of visual guided alignment can be entered. This saves time and effort when dragging the drive device and completes the coarse alignment process efficiently and quickly.

[0025] 3. By setting up a positioning component and acquiring the current image of the marker component through an imaging device, the current image of the marker component is processed and calculated to obtain the desired pose of the drive device, control the action of the treatment device (including six degrees of freedom of movement, or translation only, or rotation only), and finally achieve the alignment of the beam channel of the treatment device and the beam limiting device, complete the fine alignment process, improve the flexibility of the trajectory planning of the drive device, and improve docking efficiency and alignment accuracy.

[0026] 4. By adopting a spherical structure for the marking component, the image obtained by the imaging device from photographing the marking component in any posture and at any angle is circular. This allows for the fitting of a more perfect two-dimensional circle, making it easier to determine the coordinates of the marking component. Attached Figure Description

[0027] Figure 1 is a schematic diagram of the structure of the radiotherapy equipment used in an embodiment of the present invention; Figure 2 is a schematic diagram of the structure of the traction handle of the radiotherapy equipment used in an embodiment of the present invention; Figure 3 is a schematic diagram of the structure of the beam limiting device used in the first embodiment of the present invention; Figure 4 is a schematic diagram of the structure of the beam limiting device used in the second embodiment of the present invention; Figure 5 is a flowchart of the alignment method used in an embodiment of the present invention; Figure 6 is a diagram of the admittance control model in the alignment method used in an embodiment of the present invention; Figure 7 is a schematic diagram of the coordinate system labeling in the alignment method used in an embodiment of the present invention; Figure 8 is a partially enlarged schematic diagram of Figure 7; Figure 9 is a schematic diagram of the gravity effect of the traction handle in the six-dimensional force sensor coordinate system provided by the alignment method used in an embodiment of the present invention; Figure 10 is a schematic diagram of the binocular stereo measurement principle in the alignment method used in an embodiment of the present invention; Figure 11 is a schematic diagram of solving the relative pose relationship between two coordinate systems using point pairs in the alignment method used in an embodiment of the present invention; Figure 12 is a schematic diagram of the epipolar constraint in the alignment method used in an embodiment of the present invention.

[0028] The above-mentioned figures include the following reference numerals: 10, lesion; 1, treatment device; 11, shell; 12, beam outlet tube; 2, drive device; 3, beam limiting device; 31, beam channel; 32, main body of beam limiting device; 33, mounting plate; 4, traction handle; 41, first connecting part; 42, second connecting part; 43, measuring component; 5, marking component; 6, imaging device; 7, base; 71, power source module; 72, control console; 73, equipment cabinet; 74, operating handle; 75, laser rangefinder; 81, beam limiting bracket; 82, beam modulator; 83, beam blocking plate. Detailed Implementation

[0029] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0030] According to an embodiment of the present invention, a radiotherapy device is provided, as shown in Figures 1 to 12, comprising: a treatment device 1 for generating a treatment beam; a driving device 2 for driving the treatment device 1 to move; a beam limiting device 3 having a beam channel 31 through which the treatment beam irradiates the patient's lesion 10; a traction device for bearing the traction force and traction torque applied by the user to traction the treatment device, the traction device including a measuring component 43 for measuring the traction force and torque applied to the traction device; and a positioning assembly including a marking component 5 and an imaging device 6, the marking component 5 comprising at least three components, the marking component 5 being fixedly disposed on the beam limiting device. On device 3, imaging device 6 is used to image the marker component 5; control module, which is signal connected to treatment device 1, drive device 2, traction device and imaging device 6 respectively, is configured to: calculate the desired pose of treatment device 1 in Cartesian space based on the traction force and torque applied to the traction device, control treatment device 1 to move to a first target pose based on the desired pose of treatment device 1 in Cartesian space to obtain the current image of marker component 5; obtain the current pose of beam limiting device 3 based on the current image of marker component 5, and control treatment device 1 to move to a second target pose based on the current pose of beam limiting device 3 to align the treatment beam with beam channel 31.

[0031] By setting up a traction device, when radiotherapy is about to begin, the traction device 1 moves towards the area to be aligned. The traction force and torque acting on the traction device are measured by the measuring component 43. By constructing the admittance relationship between the force and torque at the point of application of the traction force and the end-effector pose of the treatment device, the intention of traction is calculated, and a new desired pose command for the end of the radiotherapy head is generated. This allows the drive device to move to the first target pose in accordance with the dragging force of the human hand. By processing the traction force and torque, the intention of traction is calculated, and the collected force and torque information is converted into position and posture commands for the treatment device in Cartesian space. Based on the position and posture commands, the movement trajectory of the drive device 2 is planned so that the drive device 2 moves in accordance with the dragging force of the human hand. When the marking component 5 enters the field of view of the imaging device 6, the control module can acquire the marking component 5 according to certain rules. The current image shows that the conditions for compliant traction are met. The treatment device 1 moves to the first target pose, and the coarse alignment process is completed, allowing it to proceed to the next stage of visually guided alignment. By setting a positioning component, the marker component 5 is placed on the beam limiting device 3 according to certain marking rules. The current image of the marker component 5 is acquired by the imaging device 6. The control module processes and calculates the current image of the marker component 5 to identify the marker component 5 and to locate the beam limiting device 3, thereby obtaining the current pose of the beam limiting device 3. The desired pose of the driving device 2 is obtained through further calculation. Based on the desired pose of the driving device 2, the driving device 2 is planned to move its trajectory. The driving device 2 drives the treatment device 1 to the second target pose, ultimately aligning the treatment beam generated by the treatment device 1 with the beam channel 31, thus completing the fine alignment process.

[0032] The alignment process between the treatment device 1 and the beam limiting device 3 is configured into two stages: first, coarse alignment is achieved through compliant traction, and then fine alignment is achieved through visual guidance. This avoids the spatial limitations and operational uncertainties that exist between the human eye and the components to be aligned when only manual alignment is used. It ensures the precise alignment of the treatment beam and the beam channel 31, ensuring the safety of the Flash treatment process. This achieves a fast, convenient, intelligent, and precise alignment process for radiotherapy equipment. It not only ensures the safety of the radiotherapy process but is also the key to the efficient utilization of the Flash effect. It solves the technical problem in related technologies where aligning the treatment head of radiotherapy equipment with tumor tissue is time-consuming and laborious, resulting in low treatment efficiency.

[0033] Specifically, in this invention, the drive device 2 is a six-degree-of-freedom robotic arm, which is autonomously controlled by a position control ring to move. The drive device 2 can be used to flexibly drag the treatment device 1 in six degrees of freedom.

[0034] In the radiotherapy device of this embodiment, referring to FIG2, the treatment device 1 includes a housing 11 and a beam outlet 12 installed inside the housing 11. The beam outlet 12 is provided with a beam outlet on the side near the beam confinement device 3, and the beam outlet 12 is used to release the treatment beam.

[0035] Specifically, the treatment device 1 is used to generate a beam at a specific dose rate, especially a beam at an ultra-high dose rate that satisfies the Flash effect. Of course, the treatment device 1 is also suitable for generating beams for conventional radiotherapy.

[0036] In the radiotherapy equipment of this embodiment, the treatment device 1 is also equipped with a beam monitoring device for measuring the parameters of the treatment beam.

[0037] It should be noted that, in this invention, the treatment device 1 includes a treatment beam generating device, a beam monitoring device, and a beam exit tube 12, with the beam exit tube specifically mentioned in this invention. The beam monitoring device can be a monitoring device used for conventional radiotherapy beams, or it can be a monitoring device suitable for Flash radiotherapy beams, such as a low-pressure flat plate ionization chamber, a small-gap flat plate ionization chamber, or a galvanometer.

[0038] In the radiotherapy device of this embodiment, referring to FIG2, the traction device includes a traction handle 4, which is located on the housing 11 near the exit port. Specifically, by setting the traction handle 4 close to the exit port, the traction intention obtained by the traction handle 4 is closer to the desired position of the exit port, that is, closer to the desired position of the end of the treatment device 1.

[0039] In the radiotherapy device of this embodiment, referring to FIG2, the traction handle 4 includes: a first connecting part 41, which is fixedly connected to the measuring component 43; and a second connecting part 42, one end of which is connected to the end of the first connecting part 41 away from the housing 11, and the other end of which extends away from the driving device 2. A gripping space for accommodating a person's hand is formed between the second connecting part 42 and the treatment device 1. Specifically, by gripping the second connecting part 42, the user can drag the traction handle 4 according to the required position, posture, and speed of movement of the treatment device 1, so that the traction handle 4 obtains traction force and torque.

[0040] In some embodiments, the extending direction of the second connecting portion 42 is parallel to the extending direction of the treatment device 1. This arrangement facilitates unifying the coordinate systems of the traction handle 4 and the treatment device 1, simplifying the calculation process.

[0041] In the radiotherapy device of this embodiment, referring to FIG2, the measuring component 43 includes a six-dimensional force sensor, which can measure the three-dimensional orthogonal force and three-dimensional orthogonal torque on the traction handle 4.

[0042] Specifically, the first connecting part 41 is rigidly connected to the six-dimensional force sensor, and the six-dimensional force sensor is rigidly connected to the housing 11.

[0043] Specifically, by having the user drag the traction handle 4, the user moves according to the desired position, posture, and speed. The six-dimensional force sensor measures the force and torque acting on the traction handle 4. The control module calculates the force and torque acting on the traction handle 4 into the target's three-dimensional position coordinates (x, y, z) and three-dimensional posture coordinates (α, β, γ). Based on these coordinates, the control module converts them into the desired coordinates of the treatment device 1 and controls the joint of the drive device 2 to move to the target position, thus achieving the compliant traction function.

[0044] Specifically, the user drags the traction handle 4, and a six-dimensional force sensor detects the force or torque applied by the user, transmitting this force or torque signal to the control module. The control module is responsible for performing zero-point compensation, gravity compensation, calculation of the traction force and torque of the user's hand, generation of new Cartesian space position compensation commands, calculation of forward and inverse kinematic joint position commands, and issuance of joint position commands. The control module communicates with each servo axis group in the drive device 2 via EtherCAT. The servo driver uses CSP (Cyclic Synchronous Position) mode to accurately execute the joint position commands of the drive device 2. The servo driver control cycle and the position command issuance cycle in the compliant traction mode are both set to 1ms. This achieves the conversion of the three-dimensional force on the traction device into compliant traction of the end position of the treatment device, and the conversion of the three-dimensional torque into compliant traction of the end posture of the treatment device.

[0045] In the radiotherapy device of this embodiment, referring to FIG3, the beam limiting device 3 includes a beam limiting device body 32 and a mounting plate 33 connected to each other. The beam limiting device body 32 has a beam channel 31, and a marking component 5 is mounted on the side of the mounting plate 33 near the treatment device 1. With the above arrangement, the position of the marking component 5 in the beam limiting device 3 is fixed. By taking an image of the marking component 5, the pose of the marking component 5 can be identified and calculated, thereby realizing the positioning of the beam limiting device 3.

[0046] In the radiotherapy device of this embodiment, referring to FIG3, at least three marker components 5 are arranged on the beam limiting device 3 at intervals and not collinearly; the distance between any two marker components 5 is ≥50mm; the difference between the distances of any two different marker components 5 is ≥3mm.

[0047] In the beam limiting device of this embodiment, at least three marking components 5 are arranged circumferentially on the mounting plate 33 with the beam channel 31 as the center.

[0048] In the beam limiting device of this embodiment, the mounting plate 33 has a disc-shaped structure, and the axis of the beam channel 31, the axis of the mounting plate 33, and the center lines of the several marking components 5 arranged at circumferential intervals are all collinear.

[0049] Specifically, the marking component 5 includes a medical optical marking ball for auxiliary positioning and a base for fixing the marking ball. The surface of the ball has a special reflective coating that can efficiently reflect near-infrared light and other rays. The marking component 5 adopts a snap-fit ​​design internally, which works in conjunction with the marking ball base for easy installation and disassembly. The medical marking ball base is used to fix the medical optical marking ball to the mounting plate 33. The marking ball base is made of stainless steel, with a snap-fit ​​at one end and a threaded end at the other, which connects to a threaded hole on the mounting plate 33.

[0050] Specifically, the marking component 5 adopts a spherical structure. The image obtained by the shooting device from the marking component 5 in any posture and at any angle is a circle. It can fit a more perfect two-dimensional circle, and thus it is easier to determine the coordinates of the marking component 5.

[0051] In this embodiment, the marking component 5 needs to meet the following conditions: ① The arrangement of the marking component 5 needs to ensure that, throughout the entire visual guidance process, regardless of the direction from which the treatment device 1 approaches the beam limiting device 3, the imaging device 6 can always capture images of more than three marking components 5, avoiding the situation where the marking component 5 is obscured. That is, there are always more than three marking components 5 in the unobstructed area. To avoid the situation where the number of marking components 5 is too small and they are obscured, for example, when the treatment device 1 approaches the beam limiting device 3, its approach angle just obscures one of them, or one of the marking components 5 is obscured during the dynamic adjustment of the treatment device 1, therefore, the number of marking components 5 is preferably at least 4, to ensure that at least 3 marking components 5 are identified even if one marking component 5 is obscured. Of course, the number of marking components 5 is not the more the better. Generally speaking, the number of marking components 5 is limited to less than 16. Too many marking components will make the size of the mounting plate 33 too large, making it difficult to store and install the beam limiting device 3.

[0052] Preferably, referring to Figure 3, there are eight marking components 5, which are distributed at intervals around the beam channel 31 on the mounting plate 33.

[0053] ② The distance between the marking components 5 needs to be no less than a certain spacing to ensure that the shooting device 6 can accurately capture the marking components 5. In this embodiment, the distance between the marking components 5 is no less than 50mm.

[0054] ③ The difference in distance between the marker components 5 is not less than a certain value, that is, the distance between each pair of marker components 5 is different. By setting different differences, the control module can quickly identify and recognize the corresponding marker components 5, and the control module can correctly identify the position and orientation of the beam limiting device. It should be noted that in this embodiment, the difference in distance between the marker components 5 is not less than 3mm.

[0055] ④ The markings printed on the mounting plate 33 must be able to be scanned by the shooting device 6 from any angle, and the color of the numbers must be different from that of the mounting plate 33 and the marking component 5 to improve the accuracy and speed of recognition.

[0056] In the second embodiment of the beam limiting device 3, referring to FIG4, in order to reduce the volume of the beam limiting device 3, the beam limiting device 3 is designed as an off-axis structure, and all the marking components 5 are set at the end away from the beam channel 31, that is, the marking components 5 and the beam channel 31 are respectively located at the two ends of the mounting plate, ensuring that the marking components 5 are not blocked by the beam exit tube. The shape of the mounting plate can be racetrack-shaped or elliptical, or other shapes.

[0057] In the second embodiment of the beam-limiting device 3, it should be noted that the number of marking components 5 needs to be limited, but the number still needs to be no less than 3 to avoid the mounting plate 33 being too large.

[0058] In the second embodiment of the beam-limiting device 3, preferably, the marking component 5 includes three parts.

[0059] Specifically, the mounting plate 33 is made of a non-reflective material to minimize interference with the shooting device 6's shooting of the marking component 5.

[0060] In some embodiments, the surface of the mounting plate 33 is matte-finished.

[0061] In some embodiments, the beam limiting device 3 includes a marking symbol, which is disposed on the mounting plate 33 on the side near the imaging device 6. Specifically, by setting the marking symbol, the control module can identify the model of the beam limiting device 3. The marking symbol includes numbers, letters, etc., and the marking symbol should have clearly visible edges and be easy to distinguish.

[0062] In some embodiments, a marking symbol "D + number" is engraved on the mounting plate 33 to indicate the inner diameter of the body 32 of the beam limiting device. Of course, the fields of the marking symbol can be expanded to add other information about the beam limiting device, such as material information.

[0063] In some embodiments, the mounting plate 33 is detachably connected to the body of the restraint device via a threaded structure.

[0064] In the radiotherapy device of this embodiment, referring to Figures 1, 3, and 4, the imaging device 6 includes a light-emitting element for emitting a light source, and a reflective layer is provided on the surface of the marking component 5 for reflecting the light source. By setting the imaging device 6 and the marking component 5, the marking component 5 can efficiently reflect the light source emitted by the light-emitting element, making the image outline clear and prominent, very easy to extract, improving the image capturing effect and image quality, and making the image extraction and coordinate acquisition more accurate in the subsequent step of obtaining the coordinates of the marking component 5.

[0065] In the radiotherapy device of this embodiment, referring to FIG1, the imaging device 6 includes at least two cameras, which are spaced apart on the imaging device 6 for simultaneously capturing images of the marker component 5. According to the above configuration, the at least two cameras of the imaging device 6 can simultaneously capture two images of the marker component 5.

[0066] Preferably, the imaging device 6 is an optical measurement sensor. The imaging device 6 captures images, and the control module tracks and measures the three-dimensional position of multiple marker components 5 installed on the surface of the target object in real time based on the near-infrared binocular stereo positioning principle.

[0067] Specifically, the imaging device 6 mainly consists of a light-emitting element and a near-infrared binocular camera. The light-emitting element can be a near-infrared LED ring light source. The imaging device 6 is installed at one end of the driving device 2 near the beam-limiting device 3, and can acquire left and right near-infrared images of the marking component 5, which is the basis for the driving device 2 to obtain sensing capabilities.

[0068] Specifically, in this embodiment, the installation of the shooting device 6 needs to meet the following conditions: ① The shooting device 6 and the driving device 2 are externally fixed, for example, the shooting device 6 and the end of the driving device 2 are fixedly connected to ensure that the two are on the same rigid body.

[0069] ② The field of view of the shooting device 6 should be obstructed as little as possible to ensure that the shooting device 6 can completely scan more than three marked parts 5 throughout the visual guidance process.

[0070] ③ The final distance between the shooting device 6 and the marking component 5 needs to be within the optimal field of view of the shooting device 6.

[0071] Specifically, the radiotherapy equipment also includes an image-assisted system, which includes a miniature color camera assembly and a short-focal-length lens assembly. The radiotherapy equipment needs to provide color images of the lesion to assist doctors in their radiotherapy operations. Since the imaging device 6 uses two infrared cameras that cannot capture images of the lesion, it cannot provide color images of the target. Therefore, an additional color camera is needed to provide color image assistance. In addition, since the lesion is very close to the end of the drive device 2, the color camera installed at the end of the drive device 2 to acquire images of the lesion needs to be used with a short-focal-length lens to acquire high-definition color images of the lesion.

[0072] Specifically, in order to capture images of the lesion at the bottom of the beam confinement device 3, both the installation position of the miniature color camera assembly and the alignment distance between the treatment device 1 and the beam confinement device 3 need to be considered. The miniature color camera assembly needs to be installed at the end of the treatment device 1, so the effect of radiation on the miniature color camera assembly must be taken into account.

[0073] In this embodiment of the radiotherapy equipment, referring to Figure 1, the radiotherapy equipment includes: a base 7, which is movably disposed, and a drive device 2 is fixedly disposed on the base 7; a power source module 71, which is disposed on the base 7 at a distance from the drive device 2, and is connected to the treatment device 1. The power source module 71 also includes an energy storage component for supplying energy to the treatment device 1; and a control console 72, which includes control function keys and a human-machine interface. The control console 72 is signal-connected to the control module to realize remote control of the control module.

[0074] By setting up an energy storage component, the radiotherapy equipment can achieve a dose delivery of 25 Gy within 0.1 seconds, enabling high power output in the treatment device 1.

[0075] The console 72 is configured to display system information and control the operating status in real time.

[0076] Specifically, the radiotherapy equipment includes an operating handle 74 and an equipment cabinet 73. The equipment cabinet 73 is used to supply power and maintain the temperature of the system. The equipment cabinet 73 is equipped with a main power switch for the system and a system temperature control device, which is connected to the base 7 and the control console 72 via cables. The temperature control device can be air-cooled or water-cooled. Preferably, in this embodiment, a water-cooled unit is used for cooling. The temperature control device uses high-pressure water pipes to achieve water cooling and temperature control of the treatment device 1 and the power source module 71. The high-pressure water pipes distribute the water supply and return channels in the base 7.

[0077] In the radiotherapy device of this embodiment, referring to FIG1, the bottom of the base 7 is provided with multiple walking wheels and a battery for driving the multiple walking wheels, so that the radiotherapy device can move between multiple operating rooms; the base 7 also includes a locking mechanism for restricting the movement state of the multiple walking wheels. The locking mechanism is signal connected to the control module and is configured to: obtain the movement state of the drive device 2, and if the drive device 2 is in the movement state, then open the locking mechanism.

[0078] For safety reasons, the movement of the base 7 and the action of the drive device 2 are mutually exclusive during the entire operation of the equipment. That is, the drive device 2 is locked when the base 7 moves, or the base 7 is locked when the drive device 2 is activated.

[0079] Specifically, the base 7 is equipped with several anti-collision blocks to provide anti-collision functionality. Laser rangefinders 75 are also installed diagonally on the base 7, for example, one at the corner near the robotic arm and another at the corner near the power source module 71. These rangefinders are used to sense the distance between the radiotherapy equipment and surrounding objects, preventing collisions between the base and these objects during movement.

[0080] In this embodiment of the radiotherapy device, referring to FIG1, the radiotherapy device includes: a beam-limiting support 81, which is used to fix the beam-limiting device 3; a beam modulator 82, which is connected to the end of the beam-limiting device 3 away from the treatment device 1, and is used to modulate the dose distribution in the lesion 10 region; and a beam-blocking plate 83, which is disposed opposite to the treatment beam and is used to block the treatment beam from passing through the beam-blocking plate 83.

[0081] Specifically, one end of the beam-limiting bracket 81 is fixed to the hospital bed, and the other end is used to clamp the beam-limiting device 3, ensuring that the beam-limiting device 3 is always aligned with the tumor lesion and preventing movement of the beam-limiting device 3 during treatment. The beam-limiting bracket 81 can be adjusted in multiple degrees of freedom, facilitating the adjustment of the relative posture between the beam-limiting device 3 and the tumor. The position of the beam-limiting device 3 should be determined according to the specific location and shape of the lesion 10, isolating normal tissue as much as possible to reduce or avoid the dose of radiation to normal tissue. After the position of the beam-limiting device 3 is determined, it is fixed and maintained by the beam-limiting bracket 81.

[0082] Specifically, the beam blocking plate 83 is set in the direction of beam propagation to block the therapeutic beam that passes through the lesion in the human body from continuing forward, preventing it from irradiating other spaces and preventing the radiation dose in non-therapeutic spaces in the direction of beam propagation from exceeding the standard.

[0083] In the radiotherapy device of this embodiment, referring to FIG1, the treatment device 1 is configured to emit an ionizing radiation dose of at least 25 Gy in less than 0.1 s.

[0084] In the alignment method of this embodiment, referring to FIG5, the alignment method of the radiotherapy device is applicable to the radiotherapy device described above. The alignment method includes: S1: obtaining the treatment plan, and the treatment device 1 enters the alignment preparation state.

[0085] Specifically, before the device is put into operation, the drive unit 2 remains folded to reduce the space occupied by the entire device and to ensure the safety of the device during transportation. After confirming the treatment plan and usage requirements, the user uses the operating handle 74 to control the base 7 to move to the alignment preparation position. At this time, the base 7 can obtain power through the energy storage component or the system cable. The user releases the drive unit 2, changing it from the folded state to the open state, and enters the alignment preparation state where the treatment device 1 is aligned with the lesion 10.

[0086] Specifically, the alignment preparation position is determined by the user based on the usage environment, such as the position of the restraint device 3 and other equipment in the usage environment, to ensure that there is sufficient safety margin when the drive device 2 is activated.

[0087] S2: Calculate the desired pose of the treatment device 1 in Cartesian space based on the traction force and torque applied to the traction device, and control the treatment device 1 to move to the first target pose based on the desired pose of the treatment device 1 in Cartesian space to obtain the current image of the marker component 5.

[0088] When the marker component 5 enters the field of view of the imaging device 6, the control module can acquire the current image of the marker component 5 according to certain rules. At this time, after the completion conditions of compliant traction are met, the treatment device 1 moves to the first target position, the coarse alignment process is completed, and the next stage of visual guidance alignment can be entered.

[0089] S3: Obtain the current pose of the beam limiting device 3 based on the current image of the marker component 5, and control the treatment device 1 to move to the second target pose based on the current pose of the beam limiting device 3, so that the treatment beam is aligned with the beam channel 31. That is, the axis of the beam outlet or beam exit coincides with the axis of the beam channel 31. At this time, the visual guidance alignment is completed, and the radiotherapy equipment is ready to emit the beam for treatment.

[0090] In this embodiment, the current image of the marking component 5 is captured by the imaging device 6 to obtain the left and right images of the binocular camera. The epipolar line is determined by calibrating the extrinsic parameters of the imaging device 6, which facilitates the quick and easy finding of the corresponding pixel pairs in the left and right images.

[0091] Specifically, the end-effector position of treatment device 1 is the control target of the compliant traction system. The six-dimensional force sensor detects the force and torque and converts them into the force and torque at the point of application of the traction force. The three-dimensional force at the point of application of the traction force is converted into compliant traction at the end-effector position of treatment device 1, and the three-dimensional torque is converted into compliant traction at the end-effector position of treatment device 1.

[0092] In the alignment method of this embodiment, referring to FIG6, the method of calculating the desired pose of the treatment device 1 in Cartesian space based on the traction force and torque applied to the traction device, and controlling the treatment device 1 to move to the first target pose based on the desired pose of the treatment device 1 in Cartesian space to obtain the current image of the marker component 5 includes: S21: calculating the first traction force and the first traction torque of the force sensing point based on the traction force and torque applied to the traction device; constructing the admittance relationship of the first traction force and the first traction torque in the pose of the treatment device coordinate system respectively, and calculating the desired pose of the treatment device 1 in Cartesian space. Specifically, referring to Figures 7-8, for ease of algorithm design and analysis, the coordinate systems of the compliant traction system are defined as follows: 1. The base coordinate system {B} is the coordinate system of the base 7; 2. The world coordinate system {W} is the vertical projection of the origin, X, and Y directions of coordinate system {B} onto the horizontal plane, with the Z direction of {W} always pointing vertically upwards; 3. The flange coordinate system {F} and coordinate system {B} have known forward and inverse solutions and Jacobian matrices, and the flange is the flange at the connection between the drive device 2 and the treatment device 1. It should be noted that the forward, inverse, and Jacobian matrices can be provided according to the actual drive device control scheme used. This invention does not limit the specific values ​​of the parameters of the forward, inverse, and Jacobian matrices, as long as they are applicable to the drive device motion control method provided by this invention.

[0093] 4. The origin of the coordinate system {R} at the end of the treatment device is located at the end of the treatment device 1, and the direction of the coordinate system is consistent with the coordinate system {F}; 5. The origin of the coordinate system {P} at the point of application of the traction force is the equivalent point of the force exerted by the hand on the traction handle (not the actual point of application of the force by the hand), and the direction of {P} is consistent with the coordinate systems {F} and {R}.

[0094] 6. The origin of the coordinate system {H} of the towing handle is located at the center of gravity of the towing handle, and the direction of {H} is consistent with {P}, {F} and {R}.

[0095] 7. The coordinate system {S} of the six-dimensional force sensor is consistent with the custom coordinate system of the six-dimensional force sensor.

[0096] The transformation relationships between some coordinate systems are explained as follows: The transformation matrix of the base coordinate system {B} relative to the world coordinate system {W} is defined as follows: in, and Let {B} be the rotation matrix and translation vector of coordinate system {W} relative to {W}.

[0097] The transformation matrix of the flange coordinate system {F} relative to the base coordinate system {B} is defined as follows: in, and Let {F} be the rotation matrix and translation vector of coordinate system {F} relative to {B}.

[0098] The transformation matrix of the six-dimensional force sensor {S} relative to the flange coordinate system {F} is defined as follows: in, and Let {S} be the rotation matrix and translation vector of coordinate system {S} relative to {F}.

[0099] The transformation matrix of the center of gravity {H} of the traction handle relative to the six-dimensional force sensor {S} is defined as follows: in, and Let {H} be the rotation matrix and translation vector of coordinate system {H} relative to {S}.

[0100] The transformation matrix of the traction force application point {P} relative to the six-dimensional force sensor {S} is defined as follows: in, and Let {p} be the rotation matrix and translation vector of coordinate system {P} relative to {S}.

[0101] The transformation matrix of the end {R} of treatment device 1 relative to the flange coordinate system {F} is defined as follows: in, and Let {R} be the rotation matrix and translation vector of {F} relative to {R}. Based on the relationship between coordinate systems {R} and {F}, we know...

[0102] The weight of the traction handle 4, the zero drift of the six-dimensional force sensor, and the installation preload of the six-dimensional force sensor all have a significant impact on the measurement accuracy of the six-dimensional force sensor. Furthermore, the measurement value of the six-dimensional force sensor is not the traction force / torque of a human hand. Therefore, it is necessary to process the measurement value of the six-dimensional force sensor to obtain the true force and torque exerted by the human hand on the traction handle 4.

[0103] It should be noted that the origin of the coordinate system {P} for the point of application of the traction force is not the actual point of application of the traction force / torque of the human hand. The origin {P} is a hypothetical point of equivalent force and torque. In reality, there is no point of application of force / torque. The force and torque act within a small range of the handle, and the origin {P} is located above and close to this range. Therefore, this point can be assumed to be the point of equivalent force and torque.

[0104] It is understandable that the treatment device 1, the traction handle 4, and the end flange of the drive device 2 are rigidly connected, and the directions of the defined coordinate systems {H}, {P}, {F}, and {R} are consistent. Therefore, the rotation matrix between the coordinate systems {H}, {P}, {F}, and {R} is always a 3×3 identity matrix.

[0105] It should be noted that this algorithm does not have strict requirements on the installation position of the traction handle 4, only that the coordinate system {P} of the traction force application point is consistent with the direction of the coordinate systems {H}, {F} and {R}.

[0106] The compliant traction algorithm based on a six-dimensional force sensor is divided into two parts: six-dimensional force sensor data processing and compliant traction algorithm.

[0107] The method for obtaining the actual force and torque exerted by the human hand on the traction handle 4 is as follows: A six-dimensional force sensor is installed between the housing 11 and the traction handle 4, which can measure the three-dimensional orthogonal force (F) in any force system on the traction handle 4. x ,F y ,F z ) and three-dimensional orthogonal torque (M x M y M z Under static conditions, the force and torque data measured by the six-dimensional force sensor consists of three parts: (1) the sensor's own system error; (2) the gravity of the traction handle 4; and (3) the external contact force on the traction handle 4. To obtain the external contact force on the traction handle 4, it is necessary to eliminate the influence of both the sensor system error and the load gravity. As for the inertial force brought about by the movement of the robotic arm, since the robot is in slow motion during the compliant traction process: translational speed ≤ 30 mm / s, angular velocity ≤ 5° / s, the influence of the inertial force can be ignored.

[0108] The force directly measured by the six-dimensional force sensor is denoted as s F∈R 3 Torque is denoted as s M∈R 3 The force and torque information measured by the six-dimensional force sensor is influenced by the gravity of the traction handle. s G and s M g Sensor inherent error s F0 and s M0, the force and torque exerted by the human hand on the sensor s F f and s M f Composition, thus we have: in, s F f and s M f To measure the real force and torque of a six-dimensional force sensor. s G, s M g , s F0 and s M0 represents the force and torque information that needs to be compensated.

[0109] It should be noted that during the robot's movement, the posture of the traction handle 4 changes with the movement of the treatment device 1, while the direction of gravity is always vertically downward. Therefore, the influence of the gravity of the traction handle 4 on the six-dimensional force sensor data changes continuously with the movement of the drive device 2. Eliminating the influence of the gravity of the traction handle 4 needs to be done in real time according to the current posture of the drive device 2.

[0110] Because the tow handle 4 is lightweight and has a regular shape, and the six-dimensional force sensor connectors are all machined parts, the weight of the tow handle 4 and the position of its center of gravity in the six-dimensional force sensor coordinate system can be measured relatively accurately offline. Figure 9 shows a schematic diagram of the gravitational effect of the tow handle in the six-dimensional force sensor coordinate system. The gravitational force of the tow handle 4 in the world coordinate system {W} is known to be... W G = [0 0 G] T Then the three-dimensional force components of the traction handle 4 under the coordinate system of the traction handle's center of gravity {H} are: in, Let be the rotation matrix of the world coordinate system {W} relative to the tow handle's center of gravity coordinate system {H}. Since the tow handle's center of gravity is at the origin of the tow handle's center of gravity coordinate system {H}, the torque of gravity in the three axes of the {H} coordinate system is 0. Therefore, the six-dimensional force / torque of gravity in the {H} coordinate system is: The force / torque exerted by the gravity of the traction handle 4 on the six-dimensional force sensor coordinate system {S} is as follows: When the drive device 2 is in a certain position, the force and torque exerted by the gravity of the traction handle 4 on the six-dimensional force sensor are as follows: in, for A skew-symmetric matrix of vectors.

[0111] Due to the zero drift and installation preload of the six-dimensional force sensor, its reading is not zero under no-load conditions. Assuming the sensor's own systematic error is constant, this is called the "zero point." After the traction handle 4 is installed, the fastening method and degree of fastening between the traction handle 4 and the six-dimensional force sensor also affect the sensor's zero point. Therefore, the zero point of the six-dimensional force sensor cannot be accurately obtained when the sensor is unloaded; the zero point must be determined under the condition that the traction handle 4 is installed.

[0112] When there is no external force acting on the traction handle 4, the force and torque information measured by the six-dimensional force sensor consists of the influence of gravity on the traction handle 4 and the sensor's own error. Equation (7) can be rewritten as: When there is no external force applied to the traction handle 4, the measured value of the six-dimensional force sensor s F and s M minus gravity compensation value s G and s Mg That is, the zero point value.

[0113] In summary, by combining equations (7), (10), and (11), the true values ​​of the force and torque exerted by the human hand on the traction handle under the six-dimensional force sensor can be calculated. s F f and s M f .

[0114] Specifically, calculating the first traction force and the first traction torque at the force sensing point based on the traction force and torque applied to the traction device includes: traction force measured by a six-dimensional force sensor. s F f and traction torque s M f And from equation (11), we can obtain that the actual force and torque exerted by the human hand on the handle in the coordinate system {P} of the point of application are expressed as: in, for A skew-symmetric matrix.

[0115] Force P F f In the base coordinate system {B}, it can be represented as: Torque P F f In the coordinate system {R} at the tip of the radiotherapy head, it can be represented as: S22: Obtain the traction mode selection signal input by the user, select the corresponding preset traction mode according to the traction mode selection signal input by the user, and adjust the desired pose according to the selected preset traction mode and the preset method.

[0116] Specifically, from the perspective of ease of use of compliant traction, compliant traction is divided into three working modes for users to choose from: six-degree-of-freedom compliant traction mode, position traction mode, and posture traction mode. In the "six-degree-of-freedom compliant traction mode," users can drag the traction handle 4 to achieve arbitrary positional adjustment of the end of the treatment device 1 in six degrees of freedom. The "position compliant traction mode" is used when it is only necessary to drag the end of the treatment device to any position in Cartesian space. The "posture compliant traction mode" is used when it is only necessary to drag the end of the treatment device to a fixed position in Cartesian space for posture adjustment.

[0117] In the radiotherapy device of this embodiment, referring to Figure 2, the treatment device 1 includes a three-legged three-position toggle switch spaced apart from the traction handle 4. The three-legged three-position toggle switch includes several control positions. The three-legged three-position toggle switch is signal-connected to the control module and is used to select the working mode.

[0118] Specifically, the step of obtaining the user-inputted traction mode selection signal includes: obtaining the user-inputted traction mode selection signal using a three-legged three-position toggle switch, wherein the three positions of the three-legged three-position toggle switch correspond to the six-degree-of-freedom traction mode, the position traction mode, and the attitude traction mode, respectively. The three-legged three-position toggle switch further facilitates the user in selecting the traction mode.

[0119] Specifically, the desired pose includes the desired position and desired posture at time t+1, and the step of adjusting the desired pose according to the selected preset traction mode and the preset method includes: if the selected preset traction mode is a six-degree-of-freedom traction mode, the desired pose is not adjusted.

[0120] Specifically, the desired pose includes the desired position and desired posture at time t+1. The step of adjusting the desired pose according to the selected preset traction mode and the preset method includes: if the selected preset traction mode is the position traction mode, modifying the desired posture at time t+1 in the desired pose to the desired posture at time t.

[0121] Specifically, the desired pose includes the desired position and desired posture at time t+1. The step of adjusting the desired pose according to the selected preset traction mode and the preset method includes: if the selected preset traction mode is the posture traction mode, modifying the desired position at time t+1 in the desired pose to the desired position at time t.

[0122] Referring to Figure 6, the desired pose command x in Cartesian space at the end of the drive unit. d =[p d θ d ]∈R 6 The drive unit position control module consists of forward kinematics, inverse kinematics, servo position control, and the drive mechanism. The corrected acceleration in Cartesian space at the drive unit's end effector is calculated using an admittance model. for: Where M, B∈R 6×6 The matrix is ​​a positive definite diagonal matrix, where f represents the inertial and damping characteristics, respectively, and is an adjustable parameter of the admittance model. e ∈R 6 The force and torque at the point of application of the traction force are described as follows: These represent the pose and velocity errors of the treatment device's end effector in Cartesian space: The difference between the actual position and the desired position of the end of the treatment device is: Where p,p d ∈R 3These represent the actual position and the desired position of the end of the treatment device relative to the base coordinate system {B}, respectively.

[0123] The difference between the actual velocity and the desired velocity (desired velocity is 0) at the tip of the treatment device is: Where, v∈R 3 The actual velocity of the end of the treatment device relative to the base coordinate system {B}.

[0124] The deviation between the actual and desired orientation of the treatment device's end effector (axis-angle representation) is represented by the corresponding rotation matrix. The calculation method is as follows: Among them, R,R d ∈R 3×3 This is a rotation matrix representation of the actual and desired orientations of the end of the treatment device relative to the base coordinate system {B}.

[0125] This refers to the deviation between the actual angular velocity and the desired angular velocity (desired velocity is 0) at the end of the treatment device, i.e.: Integrating the obtained corrected pose acceleration, the desired corrected pose can be calculated as follows. Correcting the desired pose From the corrected position and correct posture Composition, that is Combined with the desired pose command at time t+1 We can obtain: in, for Rotation matrix representation, The result calculated for equation (23) The rotation matrix representation. Reusing the axis angle description Combining equation (24) and desired pose The expected command at the end of the treatment device at time t+1 is calculated as follows: The input is passed into the inner loop Cartesian space servo position controller as the desired pose command at time t+1 to achieve six-degree-of-freedom admittance control.

[0126] It should be noted here that x at the initial moment d The desired pose command at the initial moment of the drive device's end effector, and x at time t+1 d x at time t u ,Right now

[0127] It should be noted here that in equation (16) R M f and B F f The torque and force at the point of application of the traction force are described relative to the coordinate system of the end of the treatment device and the base coordinate system, respectively.

[0128] It should be noted here that in actual use, it can be... It can be described using rotation matrices or quaternions and directly used as end-effector posture control commands for the treatment device.

[0129] It should be noted here that in actual use, the equation (15) Usable Replacement, initial Set to 0, It can be calculated from equation (15).

[0130] It should be noted that, in actual use, the current position of the treatment device's end effector cannot be used as the desired position command for that current moment. Because there is an error between the expected pose command and the actual pose, the control error of the drive device will accumulate. Only x at time t can be used u replace.

[0131] As can be seen from the above analysis of the six-degree-of-freedom admittance control, the admittance control of each degree of freedom is decoupled from each other. The selected preset traction mode is the position traction mode. Therefore, the position admittance control only needs to be the desired posture command of the treatment device end at time t+1 in equation (25). Replace with

[0132] Similar to position-related admittance control, if the selected preset traction mode is posture traction mode, posture-related admittance control only requires setting the desired position command of the treatment device end at time t+1 in equation (25). Replace with

[0133] Specifically, the step of adjusting the desired pose according to the selected preset traction mode and a preset method further includes: establishing the description relationship between the end coordinate system {R} of the treatment device and the base coordinate system {B}, calculating the real-time transformation matrix of the coordinate system {R} in the coordinate system {B}, converting the real-time transformation matrix into an RPY Euler angle description, determining whether the desired RPY Euler angle and desired position at time t are both within the workspace, and determining whether to output an alarm signal related to equipment abnormality based on the determination result.

[0134] Specifically, the step of adjusting the desired pose according to the selected preset traction mode and a preset method further includes: if either the desired RPY Euler angle or the desired position at time t is not within the workspace, outputting an alarm signal related to equipment abnormality.

[0135] Specifically, the step of adjusting the desired pose according to the selected preset traction mode and the preset method further includes: if the desired RPY Euler angle and desired position at time t are within the workspace, calculating the desired RPY Euler angle and desired position at time t+1, determining whether the desired RPY Euler angle and desired position at time t+1 are both within the workspace, and determining whether to directly perform inverse kinematics calculation based on the determination result.

[0136] Specifically, the step of determining whether the expected RPY Euler angles and expected position at time t+1 are both within the workspace, and determining whether to directly perform inverse kinematics calculation based on the adjusted expected pose at time t+1 based on the determination result, includes: If the expected RPY Euler angles and expected position at time t+1 are both within the workspace, then directly perform inverse kinematics calculation based on the adjusted expected pose at time t+1.

[0137] Specifically, the step of determining whether the expected RPY Euler angles and expected position at time t+1 are both within the workspace, and determining whether to directly perform inverse kinematics calculation based on the adjusted expected pose at time t+1, includes: if either the expected RPY Euler angles or the expected position at time t+1 is not within the workspace, performing inverse kinematics calculation based on the adjusted expected pose at time t.

[0138] Establish the descriptive relationship between the end coordinate system {R} of the treatment device and the base coordinate system {B}. The real-time transformation matrix of coordinate system {R} in coordinate system {B} is: Rotation matrix Converted to RPY Euler angles: Roll, Pitch, Yaw. Position of coordinate system {R} in coordinate system {B} when drive unit 2 is deployed. Euler angles (Roll, Pitch, Yaw) must always be within the workspace. Compliant traction work can only be performed under these conditions; if the workspace is exceeded, the equipment will malfunction and require repair.

[0139] In compliant traction operation, when the expected position command Roll is detected at time t+1... t+1 Pitch t+1 Yaw t+1 and When any degree of freedom exceeds the specified workspace range, the desired command value from the previous moment is sent for that degree of freedom; if the desired command value is within the workspace range, the desired command value is sent directly.

[0140] It should be noted that the compliant traction workspace and the drive unit 2 workspace are consistent. If the position and posture of the drive unit 2 at the initial moment of compliant traction exceeds the compliant traction work range, the system will report an error.

[0141] Understandably, when the desired pose command exceeds the working range, the corresponding command value is replaced with the command value from the previous moment. The joint command control cycle of the drive device 2 is 2ms, and the command value from the previous moment is already very close to the boundary of the working range.

[0142] S23: Perform inverse kinematics calculation based on the adjusted desired pose to obtain the movement trajectory of the drive device 2, and control the treatment device 1 to move to the first target pose in order to obtain the current image of the marker component 5.

[0143] Specifically, the drive device 2 is a six-degree-of-freedom drive device 2. By performing inverse kinematics calculation on the adjusted desired pose, the desired angles of each joint of the drive device 2 can be obtained. Based on the desired angles of each joint of the drive device 2, the movement trajectory of the drive device 2 can be obtained, thereby controlling the movement of each joint of the drive device 2.

[0144] In the radiotherapy device of this embodiment, referring to FIG2, the treatment device 1 includes a microswitch, which is disposed on the second connecting part 42 and is signal-connected to the control module. Specifically, the microswitch is located on the side of the second connecting part 42 closer to the treatment device 1. The microswitch is used to control the start and stop of the compliant traction program. By setting the microswitch, when a person holds the second connecting part 42, the microswitch can be pressed to open the microswitch and start the compliant traction program. When the person releases the second connecting part 42, the microswitch is released and automatically pops up, and the compliant traction is disengaged.

[0145] Specifically, inverse kinematics calculation is performed based on the adjusted desired pose to obtain the desired angles of each joint of the drive device 2. Based on the desired angles of each joint of the drive device 2, the movement of each joint of the drive device 2 is controlled, including: using a microswitch provided on the traction handle 4 to obtain the start signal of the drive device 2 from the user, determining whether the microswitch is on, and based on the determination result, determining whether to control the movement of each joint of the drive device 2 according to the desired angles of each joint of the drive device 2.

[0146] Specifically, based on the judgment result, it is determined whether to control the movement of each joint of the drive device 2 according to the desired angle of each joint, including: if the micro switch is turned on, the indicator light set on the drive device 2 is kept on; after the six-dimensional force sensor collects force or torque data, the movement of each joint of the drive device 2 is controlled according to the desired angle of each joint of the drive device 2, and the indicator light set on the drive device 2 is controlled to flash at the first preset frequency.

[0147] In a preferred embodiment, the indicator light can be replaced with an indicator light strip.

[0148] In a preferred embodiment, if the microswitch is turned on, the indicator light on the drive device 2 remains constantly lit. After the six-dimensional force sensor collects force or torque data, it controls the movement of each joint of the drive device 2 according to the desired angle of each joint, and controls the indicator light on the drive device 2 to flash at a first preset frequency. This facilitates observation by the operator and further improves the intuitiveness and usability of each stage of the compliant traction of the present invention.

[0149] If the micro switch is turned off, the control drive device 2 stops moving and the indicator light on the control drive device 2 turns off.

[0150] It is understandable that the micro switch only activates the compliant traction state. Based on the compliant traction state of the drive device 2, it is determined whether to control the movement of each joint of the drive device 2 according to the desired angle of each joint. Compliant traction can only be performed when the micro switch is turned on. The micro switch acts as an energy release switch.

[0151] Specifically, if the micro switch is off, the compliant traction state of the drive device 2 is locked, the drive device 2 stops moving, and the indicator light on the drive device 2 is turned off to indicate the current stage of the compliant traction state of the drive device 2; specifically, if the micro switch is on, the compliant traction state of the drive device 2 is activated, the indicator light on the drive device 2 is kept on, after the six-dimensional force sensor collects force or torque data, it controls the movement of each joint of the drive device 2 according to the desired angle of each joint, and controls the indicator light on the drive device 2 to flash at a first preset frequency to indicate the stage of the compliant traction state of the drive device 2.

[0152] Understandably, in the preferred embodiment, when the staff member holds the traction handle 4, the micro switch is pressed, the compliant traction state is activated, and the indicator light remains on. At this time, if the staff member has not applied force or torque to the traction handle 4, the drive device 2 does not operate. When force or torque is applied, compliant traction begins to be applied to the drive device 2, and the treatment device 1 follows the movement of the drive device 2, with the indicator light flashing at a frequency of 2 Hz. When the traction handle 4 is released, the micro switch is released, the compliant traction state is not activated, the indicator light goes out, and the drive device 2 does not operate at this time.

[0153] It should be noted that the present invention, through the setting of a micro switch, further ensures that the drive device 2 will not move unexpectedly, which greatly improves the intelligence, safety and reliability of the present invention.

[0154] In the alignment method of this embodiment, the method of controlling the treatment device 1 to move to the first target pose to obtain the current image of the marker component 5 includes: determining whether the treatment device 1 has reached the first target pose; including: determining whether the number of marker components 5 in the current image is greater than or equal to a first preset threshold; if the number of marker components 5 is greater than or equal to the first preset threshold, then determining the force condition of the traction device; if the traction force and torque applied to the traction device are zero, then the treatment device 1 has reached the first target pose.

[0155] Preferably, the number of the first preset thresholds is 3.

[0156] Understandably, in the preferred embodiment, when the staff member holds the traction handle 4, the micro switch is pressed, the compliant traction state is activated, and the indicator light remains on. At this time, if the staff member has not applied force or torque to the traction handle 4, the drive device 2 does not operate. When force or torque is applied, compliant traction begins to be applied to the drive device 2, and the treatment device 1 follows the movement of the drive device 2, with the indicator light flashing at a frequency of 2 Hz. When the traction handle 4 is released, the micro switch is released, the compliant traction state is not activated, the indicator light goes out, and the drive device 2 does not operate at this time.

[0157] It is understandable that when the compliant traction device 3 is brought into the field of view of the imaging device 6, and the number of marker components 5 collected by the imaging device 6 is greater than or equal to 3, the current pose of the compliant traction device 3 can be calculated using the three-dimensional position coordinates of at least 3 marker components 5. The path planning of the next stage can be completed using the current pose of the compliant traction device 3. Therefore, the completion condition of compliant traction is met at this time.

[0158] When the conditions for completing compliant traction are met, the user will be notified through the human-machine interface that compliant traction has been completed. The user can choose to release the traction handle 4 to stop traction, or choose to continue traction of the traction handle 4.

[0159] When the user releases the traction handle 4 to stop traction, the treatment device 1 reaches the first target position and can transition from the compliant traction stage to the visual guidance stage. The remaining alignment path can be automatically completed through visual guidance, and visual guidance alignment is automatically activated. When the user continues to pull the traction handle 4, compliant traction continues until the compliant traction stop condition or the forced stop condition is met.

[0160] In the alignment method of this embodiment, the alignment method further includes: if the number of marker components 5 is greater than or equal to a first preset threshold, obtaining the current pose of the beam limiting device 3 based on the current image of the marker components 5, determining whether the difference between the current pose of the treatment device 1 relative to the beam limiting device 3 and the desired pose is less than or equal to a third preset threshold based on the current pose of the beam limiting device 3, and determining that it is necessary to exit the compliant traction mode if the difference between the current pose of the treatment device 1 relative to the beam limiting device 3 and the desired pose is less than or equal to the third preset threshold.

[0161] Specifically, the appropriate value for the third preset threshold needs to be obtained through simulation and actual machine testing.

[0162] The desired pose of the treatment device 1 is recorded as the first pose. The position error and angle error between the current pose and the first pose of the radiotherapy head are calculated. The current pose includes the current position and the current posture. The first pose includes the first position and the first posture. The position error is the Euclidean distance between the current position and the first position. The difference between the roll angle, pitch angle and yaw angle of the current posture and the first posture are calculated respectively. The maximum value of the difference is recorded as the angle error. The third preset threshold includes the third angle threshold and the third position threshold. It is determined whether the angle error is less than or equal to the third angle threshold and whether the position error is less than or equal to the third position threshold. Based on the judgment result, it is determined whether it is necessary to exit the compliant traction mode.

[0163] If the angle error is less than or equal to the third angle threshold, or the position error is less than or equal to the third position threshold, it is determined that the compliant traction mode needs to be exited.

[0164] If the angle error is greater than the third angle threshold, or the position error is greater than the third position threshold, it is determined that it is not necessary to exit the compliant traction mode.

[0165] If the angle error is less than or equal to the third angle threshold and the position error is less than or equal to the third position threshold, the present invention determines that the compliant traction has reached its maximum limit and needs to be forcibly exited from the compliant traction mode in order to proceed to the subsequent visual guidance stage.

[0166] If the angle error is greater than the third angle threshold and the position error is greater than the third position threshold, the present invention determines that the relative pose compliant traction has not yet reached its maximum limit and there is no need to forcibly exit the compliant traction mode.

[0167] It is understood that the present invention determines whether compliant traction should be forcibly withdrawn by judging whether the relative posture of the treatment device 1 and the restraint device 3 conforms to the preset rules. This eliminates the need for manual judgment, avoids the possibility of errors in manual judgment, greatly reduces the workload of staff, improves the reliability of compliant traction, improves traction efficiency and reliability, and further enhances the intelligence and reliability of the present invention.

[0168] Specifically, the method further includes: if it is determined that the compliant traction needs to be forcibly disengaged, outputting a prompt signal regarding the forced completion of the compliant traction, and controlling the indicator light set on the drive device 2 to flash at a second preset frequency; if it is determined that the compliant traction has not been forcibly disengaged, controlling the indicator light set on the drive device 2 to continue flashing at a third preset frequency.

[0169] In a preferred embodiment, the present invention controls the indicator light on the drive device 2 to flash at a second preset frequency, which is significantly greater than a third preset frequency. For example, in this embodiment, the indicator light on the drive device 2 is preferably controlled to flash at 6Hz. Alternatively, the color of the indicator light can be changed to provide a reminder. Specifically, the method further includes: if it is determined that a forced exit from the compliant traction mode is required, the movement of each joint of the drive device 2 is no longer controlled according to the desired angle of each joint, and the indicator light on the drive device 2 continues to flash at the second preset frequency; if it is determined that an exit from the compliant traction mode is not required, the movement of each joint of the drive device 2 continues according to the desired angle of each joint, and the indicator light on the drive device 2 flashes at the third preset frequency.

[0170] Understandably, the actual product uses flexible traction to bring the treatment head closer to the slant tube. When the optical measurement sensor in the visual guidance system identifies three or more marker balls on the slant tube, the conditions for completing the flexible traction are met. At this point, the traction can be released (meeting the stopping condition for compliant traction), allowing the visual guidance system to take over and continue aligning the slant tube with the slant tube. Flexible traction can still be used when "at least three marker components 5 enter the field of view of the imaging device 6," allowing the treatment head to continue approaching the slant tube. However, it cannot approach indefinitely; when it gets close enough, the visual guidance system takes over, and the flexible traction is forcibly disengaged.

[0171] By constructing the admittance relationship between the force and torque at the point of application of the traction force and the end-effector pose of the treatment device 1, a new desired pose command for the end-effector of the treatment device 1 is generated to achieve compliant traction function for the end-effector of the treatment device 1. This method uses equivalent traction force and torque application points, which can accurately calculate the traction intention of the human hand, and does not have strict requirements on the installation position of the traction handle 4, only requiring that the coordinate system of the point of application of the traction force and the coordinate system of the end-effector of the treatment device 1 be kept consistent.

[0172] This invention also discloses a position-only compliant traction mode and a posture-based compliant traction mode, enabling precise positioning of compliant traction. When the position of the end of the treatment device 1 is fixed, activating posture-based compliant traction can effectively adjust the posture of the end of the treatment device 1. This significantly improves the intelligence, reliability, and usability of the invention, and greatly expands its application scenarios.

[0173] By calculating the difference between the current pose and the desired pose of the treatment device 1, it is determined whether the compliant traction of the drive device 2 has been completed, and the indicator lights are used to indicate the different frequencies at each stage of operation, which greatly improves the intelligence, usability and practicality of the invention.

[0174] In the alignment method of this embodiment, the method of obtaining the current pose of the beam limiting device 3 based on the current image of the marker component 5 and controlling the treatment device 1 to move to the second target pose based on the current pose of the beam limiting device 3 includes: obtaining the desired pose of the driving device 2 based on the current pose of the beam limiting device 3; and controlling the treatment device 1 to move to the second target pose based on the desired pose of the driving device 2.

[0175] It should be noted that after visual guidance is activated, the desired pose of the driving device 2 is continuously calculated based on the current pose of the treatment device 1, the relative pose of the treatment device 1 and the confinement device 3, and the calibration extrinsic parameters.

[0176] In this embodiment, the control module plans a movement trajectory for the drive device 2 based on the current pose and the desired pose trajectory of the drive device 2, and the position control loop of the drive device 2 controls the drive device 2 to move towards the desired pose along the planned trajectory.

[0177] In this embodiment, as the position control loop controls the drive device 2 to move along the planned trajectory, the imaging device 6 continuously captures images of the marker component 5, continuously calculates the desired pose of the drive device 2, and continuously plans the motion path of the drive device 2 until the visual guidance stopping condition is met.

[0178] In the alignment method of this embodiment, the method of obtaining the current pose of the beam limiting device 3 based on the current image of the marker component 5 includes: obtaining the current coordinates of the marker component 5 in the coordinate system of the shooting device based on the current image of the marker component 5.

[0179] The current coordinates of the marker component 5 in the beam-limiting device coordinate system are obtained based on the current image of the marker component 5.

[0180] The current pose of the beam limiting device 3 in the shooting device coordinate system is obtained based on the current coordinates of the marking component 5 in the shooting device coordinate system and the current coordinates of the marking component 5 in the beam limiting device coordinate system.

[0181] Specifically, see Figure 11, point p i The coordinates in coordinate system A are: Point p i The coordinates in coordinate system B are: Then the rotation of coordinate system A relative to coordinate system B Horizontal displacement Satisfaction formula: When the number of point pairs is greater than 3, the optimization formula can be solved: achievable and The optimal solution is found by using the current coordinates of the marker component 5 in the shooting device coordinate system and the current coordinates of the marker component 5 in the beam limiting device coordinate system. The rotation of the shooting device coordinate system relative to the beam limiting device coordinate system can then be obtained. Horizontal displacement The pose of the beam limiting device 3 in the beam limiting device coordinate system is fixed and known, so the current pose of the beam limiting device 3 in the shooting device coordinate system can be obtained.

[0182] In the alignment method of this embodiment, the method for obtaining the current coordinates of the marker component 5 in the coordinate system of the shooting device based on the current image of the marker component 5 includes: extracting the outline of the marker component 5 in the current image according to a preset rule.

[0183] Specifically, the method for extracting the contour of the marked component 5 in the current image according to preset rules includes: converting the left and right infrared images into grayscale images; performing binarization processing on the grayscale images; and extracting the edges of all marked components 5 in the left and right images.

[0184] Specifically, the edges of all marked components in the left and right images were extracted using the Canny edge detection algorithm. Canny edge detection is mainly divided into four parts: image denoising, gradient calculation, non-maximum suppression, and double threshold boundary tracking.

[0185] Specifically, image denoising is the first step in edge detection, mainly removing noise from the image to prevent noise interference with edge detection. Gaussian blur is a commonly used denoising method, which mainly utilizes a two-dimensional Gaussian distribution function. Determine the weights of the points surrounding the center point of the denoising convolution kernel.

[0186] Edge detection requires obtaining the gradient information of an image, and edges are determined based on the gradient magnitude and direction. Calculating the gradient magnitude and direction using the Sobel operator is a common method. The Sobel operator consists of two templates: one for the vertical direction and one for the horizontal direction.

[0187] The formulas for calculating the gradient magnitude G and gradient direction θ are as follows:

[0188] After obtaining the gradient magnitude and gradient direction of the image, non-maximum suppression (NMS) is performed on the image edges using the obtained gradient magnitude and gradient direction. Since the gradient direction is perpendicular to the edge direction, NMS can effectively remove most non-edge points.

[0189] Dual-threshold boundary tracking consists of two steps. First, by selecting strong and weak thresholds, points with gradient magnitudes lower than the weak threshold are set to 0, while those greater than the strong threshold are retained and marked as 255. Then, for points with gradient magnitudes greater than the weak threshold but less than the high threshold, it is determined whether there are any points in its 8-neighborhood that are greater than the strong threshold. If so, they are retained and set to 255; otherwise, they are discarded and set to 0.

[0190] The method further includes: obtaining the current coordinates of the marker component 5 in the image coordinate system based on the outline of the marker component 5.

[0191] Specifically, the method for obtaining the current coordinates of the marker component 5 in the image coordinate system based on the outline of the marker component 5 includes: fitting a two-dimensional circle based on the pixel coordinates of the edge of the marker sphere in the image to obtain the pixel coordinates of the center of the circle.

[0192] Specifically, the outline of the marked component 5 extracted from the image is a set of two-dimensional pixels with two-dimensional pixel coordinates. These pixel sets are not the feature points we need; the feature points we need are the centers of the two-dimensional pixel circles. Therefore, we need to fit the circle equation based on these pixel sets to obtain the center pixel coordinates.

[0193] Let the equation of the pixel circle be: (u i -u0) 2 +(v i -v0) 2 -r 2 =0, {(u i ,v i Let (u0, v0) be the set of two-dimensional pixels representing the outline of component 5, (u0, v0) be the center of the pixel circle, and r be the radius of the circle. Then u0, v0, and r can be obtained by solving the formula: (u0, v0, r) = argmin{(u0, v0, r)}. i -u0) 2 +(v i -v0) 2 -r 2}get.

[0194] Specifically, referring to Figure 12, the method for obtaining the current coordinates of the marker component 5 in the coordinate system of the shooting device based on the current image of the marker component 5 also includes determining the corresponding center point pair of the left and right images based on the epipolar constraints of the binocular camera.

[0195] Specifically, after extracting feature points (centers) from the image, it is necessary to determine corresponding point pairs in the left and right images. The most common method for finding corresponding points is feature matching, which uses the gray-level features around a feature point in one image to find the most similar region in the other image to determine the corresponding feature point. This search usually covers the entire image range, but for stereo images, the search range can be reduced by using epipolar constraints.

[0196] The basic principle of epipolar constraint is shown in Figure 9. P is a spatial point, and its projected pixels in images I1 and I2 are p1 and p2, respectively. O1 and O2 are the origins of the two cameras, and O1O2 is the baseline. The intersections of the surface PO1O2 with images I1 and I2 are I1 and I2, respectively, which are the epipolar lines. For a single image I1, the exact location of spatial point P cannot be determined by pixel p1 alone, but P must lie on ray O1p1. Therefore, the projected pixel p2 of spatial point P in image I2 must also lie on epipolar line I2. Thus, for pixel p1 in image I1, finding its corresponding point p2 in I2 only requires following epipolar line I2. The epipolar constraint can be expressed by the formula: F is called the fundamental matrix.

[0197] The method further includes: obtaining the current coordinates of the marking component 5 in the imaging device coordinate system based on the current coordinates of the marking component 5 in the image coordinate system.

[0198] Specifically, referring to Figure 10, the corresponding point pairs I in the left and right image coordinate systems are obtained through registration. l and I r For a three-dimensional point P(X, Y, Z) in the corresponding spatial coordinate system, according to similar triangles: Where x l -x r This is called parallax ((u l -u r Let f be the camera focal length and b be the baseline length, then the depth can be obtained. After obtaining depth Z, according to the imaging formula of the left camera: We can obtain X and Y.

[0199] In the alignment method of this embodiment, the method for establishing the coordinate system of the beam limiting device includes: defining the intersection of the axis of the beam channel 31 and the end face of the beam limiting device 3 near the treatment device 1 as the origin; the direction away from the treatment device 1 along the axis of the beam channel 31 as the positive direction of the Z-axis; the projection of the line connecting any marker component 5 to the origin onto the end face of the beam limiting device 3 near the treatment device 1 as the positive direction of the X-axis; determining the Y-axis according to the defined X-axis and Z-axis using the right-hand rule; and completing the establishment of the coordinate system of the beam limiting device.

[0200] Specifically, to determine the pose of the target object (beam confinement device 3), it is necessary to establish the target object's own coordinate system beforehand. The establishment of the target object's own coordinate system must facilitate the alignment of the treatment device 1 with the target object. The key to establishing the beam confinement device 3's own coordinate system is determining the Z-axis direction. This can be set as downwards along the central axis of the beam confinement device body 32, with the origin set as the intersection of the upper surface of the beam confinement device 3 and the axis. The X-axis direction is set as the projection direction of the center of a marker component 5 onto the surface of the beam confinement device 3 along the Z-axis. Finally, the Y-axis direction is determined using a right-hand rule.

[0201] After determining the coordinate system, it is necessary to determine the coordinates of each marking component 5 in the coordinate system of the beam limiting device itself. Based on the geometric information of the marking component 5 installation, the initial coordinate values ​​can be determined, while more precise values ​​need to be measured. It is feasible to obtain high-precision point cloud data by scanning the beam limiting device 3 after the marking components 5 are installed using a 3D vision sensor, and then determine the precise coordinates of the marking component 5 in the coordinate system of the beam limiting device itself based on the high-precision point cloud data.

[0202] In the alignment method of this embodiment, the method for obtaining the current coordinates of the marker component 5 in the beam-limiting device coordinate system based on the current image of the marker component 5 includes: obtaining the current coordinates of the marker component 5 in the imaging device coordinate system.

[0203] Specifically, point cloud data is obtained based on the current image of the marked component 5, all marked components 5 in the point cloud are segmented and extracted, and the position of each marked component 5 in the coordinate system of the shooting device is obtained by fitting.

[0204] The method further includes: establishing a coordinate system for the beam-limiting device.

[0205] Specifically, the plane of the mounting plate above the beam-limiting device is segmented, and the coordinates p0 of the center of the circle in the coordinate system of the imaging device are obtained by fitting the plane. This point is then set as the origin of the beam-limiting device coordinate system, and the unit vector of the plane normal is obtained. And set this direction as the Z-axis direction of the beam-limiting device coordinate system; select a point on the disk plane, and the unit vector from the center of the disk to that point... The method further includes: converting the current coordinates of the marking component 5 in the coordinate system of the shooting device into the current coordinates in the coordinate system of the beam limiting device.

[0206] Based on the above parameters, calculate the transformation relationship between the coordinate system of the imaging device and the coordinate system of the beam limiting device: Based on this transformation relationship, each marking component 5 is transformed to the beam limiting device coordinate system, thus obtaining the current coordinates of the marking component 5 in the beam limiting device coordinate system.

[0207] Specifically, the primary function of the visual guidance system is to precisely align the treatment device 1 and the confinement device 3, rather than the end of the drive device 2 or the imaging device 6. Therefore, it is necessary to establish the coordinate system of the treatment device 1 itself and accurately calibrate the extrinsic parameters between the treatment device 1 and the end of the drive device 2.

[0208] The establishment of the coordinate system of the treatment device 1 can refer to the beam limiting device 3. The Z-axis can be set to be outward along the axis of the cylinder of the treatment device 1, the origin of the coordinate system can be set to the center of the outer circle of the cylinder at the end of the treatment device 1, and the X-axis can be set to the opposite direction of the driving device body to establish a right-handed coordinate system.

[0209] When the treatment device 1 and the beam limiting device 3 are aligned, their coordinate systems should satisfy the following conditions: the Z-axis coincides, the coordinate origins are separated by a preset distance d in the Z-axis direction, and the X-axis and Y-axis can rotate around the Z-axis. However, to ensure that the marking component 5 is always within the camera's field of view, the X and Y axes can be oriented in the same way.

[0210] In the alignment method of this embodiment, the method of obtaining the desired pose of the driving device 2 based on the current pose of the beam limiting device 3 includes: converting the desired pose of the beam limiting device 3 in the coordinate system of the treatment device into the desired pose of the beam limiting device 3 in the coordinate system of the imaging device.

[0211] Specifically, the desired pose of the confinement device 3 in the coordinate system of the treatment device. The desired pose of the beam-limiting device 3 in the coordinate system of the shooting device. in This is an external parameter between the treatment device 1 and the imaging device 6.

[0212] The method further includes: obtaining a first pose relationship based on the desired pose of the beam limiting device 3 in the coordinate system of the shooting device and the current pose of the beam limiting device 3 in the coordinate system of the shooting device; wherein, the first pose relationship is the change between the current pose and the desired pose of the shooting device 6.

[0213] Specifically, the current pose of the beam-limiting device 3 in the coordinate system of the imaging device is obtained through the optical pose measurement system. Then through the formula The change in the shooting device 6 from its current pose to the desired pose was calculated.

[0214] The method further includes: obtaining a second pose relationship of the driving device 2 in the driving device coordinate system based on the first pose relationship; wherein, the second pose relationship is the change between the current pose and the desired pose of the driving device 2 in the driving device coordinate system.

[0215] Specifically, through the formula The change in the end effector position from the current pose to the desired pose was calculated. in This refers to the external parameters between the imaging device and the end of the driving device.

[0216] The method further includes: obtaining the desired pose of the driving device 2 in the driving device coordinate system based on the second pose relationship and the current pose of the driving device 2 in the driving device coordinate system.

[0217] Specifically, the current pose of the end effector in the drive device coordinate system. Given, through the formula The desired pose of the end effector is calculated.

[0218] In this embodiment, the extrinsic parameter calibration between the imaging device 6 (binocular infrared camera) and the end of the driving device 2 is easily achieved using the hand-eye calibration principle. For coordinate system A, the pose change from time k-1 to time k is... For coordinate system B, the pose change from time k-1 to time k is: but and It can be obtained through the extrinsic parameters between coordinate systems A and B Establish a connection, and the connection between the three can be expressed by the formula. This means that solving this equation will yield the external parameters to be specified.

[0219] Specifically, the main process of extrinsic parameter calibration between the imaging device 6 and the drive device 2 is as follows: ① Place n marker components (three or more) on the target object; ② Control the drive device to move, so that the imaging device scans the marker components at different positions, and obtain the positions of marker component i in the coordinate system of the imaging device at the endpoints of the interval (k-1, k). i (k-1), p i (k); ③According to Calculate the pose change of the imaging device in the interval (k-1, k). ④ The positional change of the end effector of the drive device in the interval (k-1, k) can be obtained by the drive device's own control system. ⑤ Collect data across multiple intervals and use optimization methods to find the optimal solution for the extrinsic parameters.

[0220] In this embodiment, the external parameter calibration process between the drive device coordinate system and the tool coordinate system (TCF) using the six-point method is as follows: ① Find a very precise fixed point within the operating range of the drive device 2 as a reference point; ② Determine a reference point on the tool as the origin of the tool coordinate system; ③ Manually manipulate the drive device 2 to move the TCF source point, aligning it with the fixed point in four different tool postures. The first three points are arbitrary postures, the fourth point uses the tool's reference point perpendicular to the fixed point, the fifth point moves the tool reference point from the fixed point towards the X direction of the TCF to be set, and the sixth point moves the tool reference point from the fixed point towards the Z direction of the TCF to be set; ④ The position of the TCF source point can be calculated using the position data of the first four points, and the posture of the TCF can be determined using the last two points.

[0221] Define coordinate systems B, E, and T as the drive unit base coordinate system, drive unit end effector coordinate system, and tool coordinate system, respectively; define... These represent the transformation relationships of E relative to B, T relative to E, and T relative to B, respectively. It is readily apparent that: For the selected locations i = 1, 2, 3, 4, we have: Let it remain unchanged: Not equal, but their positions If they are equal, let: Therefore: In practice, It is directly measured by the forward equation of drive device 2. By directly reading the attitude and position from the four location points, the equation can be obtained: Solving this equation will give you the location of the TCF.

[0222] After obtaining the position of the tool coordinate system (TCF), the TCF attitude is calculated using Z / X direction calibration. The TCF attitude remains unchanged throughout this process. The first attitude calibration point is taken as position point 4; the drive device 2 starts from position point 4 and moves a certain distance along the +X direction to obtain position point 5; the drive device 2 starts from position point 4 and moves a certain distance along the +Z direction to obtain position point 6.

[0223] Since the TCF attitude remains unchanged at the three calibration points, they are all equal, and the X-axis axial vector of the tool coordinate system T can be obtained: Z-axis axial vector of tool coordinate system T: Then, using the right-hand rule, the Y-axis vector of the tool coordinate system T is determined: Y = Z × X. Normalizing X, Y, and Z yields X′, Y′, and Z′, thus obtaining the orientation of the tool coordinate system T relative to the base coordinate system B. The attitude of the tool coordinate system T relative to the end effector coordinate system E can be obtained by measuring the robot's forward equations.

[0224] The TCF calibration method using a laser tracker requires installing a target ball at the TCF origin. The laser tracker then allows for real-time measurement of the TCF origin's coordinates in the laser tracker's coordinate system. The basic principle is similar to the six-point method, but external measurements are used to improve accuracy. During attitude calibration, the TCF origin still needs to be moved along the +X and +Z directions of the tool coordinate system.

[0225] In this embodiment, when the extrinsic parameters at the ends of the treatment device 1 and the drive device 2 are difficult to calibrate precisely, a visual calibration method can be used to obtain the positional relationship between the ends of the treatment device 1 and the drive device 2. The process of obtaining the positional relationship between the ends of the treatment device 1 and the drive device 2 through target visual calibration is as follows: ① Manually align the treatment device 1 and the beam limiting device 3, and the control module obtains the pose of the beam limiting device 3 in the coordinate system of the imaging device at this time. This pose is called the desired pose of the target object in the coordinate system of the imaging device; ② Set the pose of the treatment device 1 relative to the coordinate system of the confinement device as the desired pose of the treatment device in the coordinate system of the confinement device. d is the distance between the end of the treatment device and the top disc of the beam limiting device 3 when manual alignment is completed; ③ According to the calibration external parameters of the imaging device 6 and the end of the driving device 2. By continuously transforming the coordinate system relationship, the external parameters between the ends of the treatment device 1 and the drive device 2 at the end of the machine head can be obtained.

[0226] Specifically, before visual guidance begins, the system needs to verify the model of the beam limiting device 3 again. If the marking component 5 installed on the beam limiting device 3 cannot be detected within the field of view of the shooting device 6, or if the detected model of the beam limiting device 3 does not match the preset model of the beam limiting device 3, visual guidance cannot begin and a prompt will be given.

[0227] In this embodiment, the method for identifying the model of the beam limiting device 3 includes: ① acquiring an image of the beam limiting device and converting it into a grayscale image; ② performing binarization processing on the image; ③ performing contour detection on the binarized image and extracting the digit contours; ④ determining the digit combination and order based on pixel distance and coordinates; ⑤ performing tilt correction on each group of digit contours and performing minimum bounding rectangle segmentation on all digits in the group; ⑥ calculating the similarity between each segmented digit in each group and the digit template to identify the digits; ⑦ composing a digit number from each group of digits and performing multiple comparisons to determine the model output.

[0228] In the alignment method of this embodiment, the method of controlling the treatment device 1 to move to the second target pose according to the desired pose of the driving device 2 includes: determining whether the treatment device 1 has reached the second target pose; including: determining whether the difference between the current pose of the treatment device 1 relative to the beam limiting device 3 and the desired pose is less than or equal to a second preset threshold. If the difference between the current pose of the treatment device 1 relative to the beam limiting device 3 and the desired pose is less than or equal to the second preset threshold, then the treatment device 1 has reached the second target pose, and the alignment of the treatment beam with the beam limiting device 3 is completed.

[0229] Specifically, at this time, the difference between the current pose and the desired pose of the treatment device 1 relative to the beam limiting device 3 is less than or equal to the second preset threshold, which satisfies the alignment accuracy between the treatment device 1 and the beam limiting device 3. The treatment device 1 reaches the second target pose, and at this time, visual guidance alignment is stopped, and the treatment device 1 is ready to perform beam treatment.

[0230] The difference between the current pose of the current treatment device 1 and the desired pose relative to the beam limiting device 3 still includes angular error and position error. The second preset threshold includes a second angle threshold and a second position threshold. It is determined whether the angle error is less than or equal to the second angle threshold and whether the position error is less than or equal to the second position threshold. Based on the determination results, it is determined whether it is necessary to exit the visual guidance mode.

[0231] If the angle error is less than or equal to the second angle threshold, or the position error is less than or equal to the second position threshold, it is determined that the visual guidance mode needs to be exited.

[0232] If the angle error is greater than the second angle threshold, or the position error is greater than the second position threshold, it is determined that it is not necessary to exit the visual guidance mode.

[0233] If the angle error is less than or equal to the second angle threshold and the position error is less than or equal to the second position threshold, the present invention determines that the visual guidance has reached its maximum and can exit the visual guidance mode.

[0234] If the angle error is greater than the second angle threshold and the position error is greater than the second position threshold, the present invention determines that the relative pose visual guidance has not yet reached its maximum and there is no need to exit the visual guidance mode.

[0235] In this embodiment, due to the control error of the drive device 2, the treatment device 1 can only be aligned with the beam limiting device 3 with a certain acceptable accuracy error. Meanwhile, the visual guidance system employs closed-loop control. To prevent the visual guidance system from continuously guiding the drive device 2 to move within an acceptable range of its desired pose, the aforementioned stopping condition needs to be set to stop the loop.

[0236] In this embodiment, the second preset threshold needs to be calculated based on the actual measurement accuracy of the positioning component, the control accuracy of the drive device 2, and the accuracy requirements. For example, when the actual measurement accuracy is high, the stopping condition can be set based on this accuracy. The system's position accuracy is σ. p The attitude accuracy is σ θ The positional accuracy index is δ p The attitude accuracy index is δ θ Then the visual guidance stop condition can be set as follows:

[0237] In the alignment method of this embodiment, the visual guidance method includes: monitoring the operation state of the limiting device 3, and determining whether to move the treatment device 1 based on the operation state of the limiting device 3; wherein, the method for determining whether to move the treatment device 1 based on the operation state of the limiting device 3 includes: determining whether the limiting device 3 rotates only around the axis of the limiting device 3; if yes, the treatment device 1 does not move; if no, the treatment device 1 is moved.

[0238] Specifically, the above judgment method is only performed in the following situations: the motion posture monitoring is only required when the limiting device 3 is finely adjusted around the axis of the limiting device body 32 in order to better fit the tumor lesion. This is to prevent the treatment device 1 from rotating along with the limiting device 3 when it is finely adjusted around the axis of the limiting device body 32, and to avoid complex posture or motion relationships between the treatment device 1 and the drive device 2.

[0239] Specifically, after the confinement device 3 is aligned with the treatment device, the action state of the confinement device 3 is monitored. When the confinement device 3 only rotates around the Z-axis, the position and orientation of the confinement device 3 have not changed, so there is no need to move the treatment device 1. When the confinement device 3 generates other action states, the desired pose of the drive device 2 is recalculated and the treatment device 1 is moved.

[0240] Specifically, the treatment device 1 and the confinement device 3 are precisely aligned through a visual guidance system. Their relative pose needs to be visualized in real time, and their pose relationship is described in the form of graphics and images. The main purposes are: to guide the operator in manual alignment; to assist the operator in determining when to stop compliant traction and start visual guidance; and to assist the operator in determining whether the final visual guidance alignment effect meets the requirements.

[0241] Therefore, during or after the visual guidance process, users can choose to manually decide whether to complete the alignment through the human-computer interaction interface of the console 72.

[0242] After alignment and preparation are completed, the control module transmits the preparation information to the console 72. The human-machine interface is used to input and confirm the treatment information, and to start and stop the beam delivery operation.

[0243] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0244] Optionally, specific examples in this embodiment can refer to the examples described in the above embodiments, and will not be repeated here.

[0245] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0246] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0247] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A radiotherapy device, characterized in that, include: Treatment device (1), used to generate a treatment beam; A drive device (2) is used to drive the treatment device (1) to move; A beam limiting device (3) is provided with a beam channel (31), through which the therapeutic beam irradiates the patient's lesion (10). A traction device for bearing the traction force and traction torque applied by the user to move the traction therapy device (1), the traction device including a measuring component (43) for measuring the traction force and torque applied to the traction device; The positioning component includes a marking component (5) and an imaging device (6). The marking component (5) includes at least three marking components, which are fixedly disposed on the beam limiting device (3). The imaging device (6) is used to photograph the marking component (5). A control module is connected to the treatment device (1), the drive device (2), the traction device, and the imaging device (6) respectively. The control module is configured to: calculate the desired pose of the treatment device (1) in Cartesian space based on the traction force and torque applied to the traction device; control the treatment device (1) to move to a first target pose based on the desired pose of the treatment device (1) in Cartesian space to obtain the current image of the marker component (5); obtain the current pose of the beam limiting device (3) based on the current image of the marker component (5); and control the treatment device (1) to move to a second target pose based on the current pose of the beam limiting device (3) to align the treatment beam with the beam channel (31).

2. The radiotherapy device according to claim 1, characterized in that, The treatment device (1) includes a housing (11) and a beam outlet (12) installed inside the housing (11). The beam outlet (12) has a beam outlet on the side near the beam limiting device (3) and is used to release the treatment beam.

3. The radiotherapy device according to claim 1, characterized in that, The treatment device (1) is also equipped with a beam monitoring device for measuring the parameters of the treatment beam.

4. The radiotherapy device according to claim 2, characterized in that, The traction device includes a traction handle (4), which is located on the housing (11) at one end near the outlet. The traction handle (4) includes: The first connecting part (41) is fixedly connected to the measuring component (43); The second connecting part (42) has one end connected to the end of the first connecting part (41) away from the housing (11), and the other end of the second connecting part (42) extends away from the driving device (2). A gripping space for accommodating a human hand is formed between the second connecting part (42) and the treatment device (1).

5. The radiotherapy device according to claim 4, characterized in that, The measuring component (43) includes a six-dimensional force sensor, which is fixedly connected to the housing (11).

6. The radiotherapy device according to claim 1, characterized in that, The beam limiting device (3) includes a beam limiting device body (32) and a mounting plate (33) connected to each other. The beam limiting device body (32) has the beam channel (31) and the mounting plate (33) has the marking component (5) installed on the side near the treatment device (1).

7. The radiotherapy device according to claim 1, characterized in that, The shooting device (6) includes a light source, and the surface of the marking component (5) is provided with a reflective layer. The marking component (5) is used to reflect the light emitted by the light source.

8. The radiotherapy device according to claim 1, characterized in that, The shooting device (6) includes at least two cameras spaced apart for simultaneously shooting the marking component (5).

9. The radiotherapy device according to claim 1, characterized in that, At least three of the marking components (5) are spaced apart from each other and are not collinearly disposed on the beam-limiting device (3); The distance between any two of the marking components (5) is ≥50mm; the difference between the distances of any two different marking components (5) is ≥3mm.

10. The radiotherapy device according to claim 1, characterized in that, The radiotherapy equipment includes: A base (7) is movably disposed, and the driving device (2) is fixedly disposed on the base (7); A power source module (71) is disposed adjacent to the drive device (2) on the base (7). The power source module (71) is connected to the treatment device (1). The power source module (71) also includes an energy storage component, which is used to supply energy to the treatment device (1). The console (72) includes control function keys and a human-machine interface. The console (72) is signal-connected to the control module to realize remote control of the control module.

11. The radiotherapy device according to claim 10, characterized in that, The base (7) is provided with a plurality of wheels and a battery for driving the plurality of wheels to move the radiotherapy equipment. The base (7) also includes a locking mechanism for restricting the movement state of the plurality of walking wheels. The locking mechanism is signal-connected to the control module and is configured to: acquire the movement state of the drive device (2), and if the drive device (2) is in a movement state, open the locking mechanism.

12. The radiotherapy device according to claim 1, characterized in that, The radiotherapy equipment includes: A beam-limiting bracket (81) is used to fix the beam-limiting device (3); A beam modulator (82) is connected to the end of the beam limiting device (3) away from the treatment device (1), and the beam modulator (82) is used to modulate the dose distribution in the lesion (10) region; A beam blocking plate (83) is disposed opposite to the treatment beam and is used to block the treatment beam from passing through the beam blocking plate (83).

13. The radiotherapy device according to claim 1, characterized in that, The treatment device (1) is configured to emit an ionizing radiation dose of at least 25 Gy in less than 0.1 s.

14. A method for aligning a radiotherapy device, characterized in that, The alignment method for the radiotherapy device is applicable to the radiotherapy device according to any one of claims 1 to 13, the alignment method comprising: Once the treatment plan is obtained, the treatment device (1) enters the alignment preparation state; The desired pose of the treatment device (1) in Cartesian space is calculated based on the traction force and torque applied to the traction device, and the treatment device (1) is controlled to move to the first target pose based on the desired pose of the treatment device (1) in Cartesian space to obtain the current image of the marker component (5). The current pose of the beam limiting device (3) is obtained based on the current image of the marking component (5), and the treatment device (1) is controlled to move to the second target pose based on the current pose of the beam limiting device (3) so that the treatment beam is aligned with the beam channel (31).

15. The alignment method according to claim 14, characterized in that, The method for calculating the desired pose of the treatment device (1) in Cartesian space based on the traction force and torque applied to the traction device, and controlling the treatment device (1) to move to a first target pose based on the desired pose of the treatment device (1) in Cartesian space to obtain the current image of the marker component (5) includes: Calculate the first traction force and the first traction torque at the force sensing point based on the traction force and torque applied to the traction device; construct the admittance relationship of the first traction force and the first traction torque in the coordinate system of the treatment device respectively, and calculate the desired pose of the treatment device (1) in Cartesian space. Obtain the traction mode selection signal input by the user, select the corresponding preset traction mode according to the traction mode selection signal input by the user, and adjust the desired pose according to the selected preset traction mode and a preset method. Inverse kinematics calculation is performed based on the adjusted desired pose to obtain the movement trajectory of the drive device (2), and the treatment device (1) is controlled to move to the first target pose to obtain the current image of the marker component (5).

16. The alignment method according to claim 14, characterized in that, The method of obtaining the current pose of the beam limiting device (3) based on the current image of the marker component (5) and controlling the treatment device (1) to move to the second target pose based on the current pose of the beam limiting device (3) includes: obtaining the desired pose of the driving device (2) based on the current pose of the beam limiting device (3) and controlling the treatment device (1) to move to the second target pose based on the desired pose of the driving device (2).

17. The alignment method according to claim 16, characterized in that, A method for controlling the treatment device (1) to move to a first target pose to obtain a current image of the marker component (5) includes: Determining whether the treatment device (1) has reached the first target pose includes: Determine whether the number of the marker components (5) in the current image is greater than or equal to a first preset threshold. If the number of the marker components (5) is greater than or equal to the first preset threshold, then determine the force condition of the traction device. If the traction force and torque applied to the traction device are zero, the treatment device (1) reaches the first target position.

18. The alignment method according to claim 14, characterized in that, The method of controlling the treatment device (1) to move to the second target pose according to the desired pose of the drive device (2) includes: Determining whether the treatment device (1) has reached the second target pose includes: Determine whether the difference between the current pose and the desired pose of the treatment device (1) relative to the beam limiting device (3) is less than or equal to a second preset threshold. If the difference between the current pose and the desired pose of the treatment device (1) relative to the beam limiting device (3) is less than or equal to the second preset threshold, then the treatment device (1) reaches the second target pose and completes the alignment of the treatment beam with the beam limiting device (3).

Images