A radiotherapy apparatus, method and storage medium

Abstract

This invention proposes a radiotherapy device, method, and storage medium. The radiotherapy device includes a treatment gantry, a treatment bed, radiotherapy components, and a scanning imaging system. The scanning imaging system includes a scanning ring and a moving mechanism. The scanning ring is configured to rotate around its own axis and is equipped with the scanning imaging components. The moving mechanism connects the scanning ring and the treatment gantry and drives the scanning ring to move between an image acquisition position and a standby position. In the image acquisition position, the image isocenter coincides with the treatment isocenter or has a preset fixed deviation; in the standby position, the scanning ring is entirely outside the irradiation path of the treatment beam. This invention achieves the movement of the scanning ring between the image acquisition position and the standby position through the moving mechanism, ensuring diagnostic-grade imaging quality while avoiding interference between the treatment beam and the imaging components. This significantly improves the accuracy and reliability of image-guided radiotherapy and enhances the flexibility of treatment.

Description

Technical Field

[0001] This invention relates to the field of radiotherapy technology, and more particularly to a radiotherapy device, method, and storage medium. Background Technology

[0002] Radiotherapy is one of the main treatment methods for cancer. Image-guided radiotherapy (IGRT) technology, by acquiring patient images before or during treatment to correct positioning errors and tumor changes between or within fractions, has become crucial for ensuring treatment precision. Currently, mainstream image-guided systems are mainly divided into two categories: one is cone-beam computed tomography (CBCT) integrated on the treatment gantry. Limited by flat panel detectors and cone-beam reconstruction algorithms, its image quality, especially the accuracy of CT values ​​and soft tissue contrast, is far lower than that of diagnostic-grade CT, making it difficult to meet the adaptive radiotherapy requirements of developing or adjusting treatment plans based on daily images; the other is a diagnostic-grade sector-beam computed tomography (SMT) independently installed in the treatment room. Although it has high image quality, it requires the patient to be transferred between the treatment bed and the CT scanner, which not only introduces additional positioning error risks but also significantly increases the floor space and construction costs of the treatment room. Summary of the Invention

[0003] This invention provides a radiotherapy device, method, and storage medium to solve technical problems such as low imaging quality, poor treatment accuracy, and low equipment space efficiency in radiotherapy systems.

[0004] The present invention provides a radiotherapy device, comprising: A treatment gantry, on which a radiotherapy unit is mounted to provide the treatment beam; The treatment bed is configured to accommodate the patient and position them at a preset image acquisition location; A scanning imaging system, mounted on the treatment gantry, includes: A scanning ring configured to rotate about its own axis, on which a scanning imaging component for performing scanning imaging is disposed; A moving mechanism, connecting the scanning ring and the treatment gantry, is configured to drive the scanning ring to move at least between an image acquisition position and a standby position; When the scanning ring is in the image acquisition position, the image isocenter point is consistent with the treatment isocenter point or has a preset fixed deviation. When the scanning ring is in the standby position, its entirety is located outside the irradiation path of the treatment beam.

[0005] In one embodiment of the present invention, the moving mechanism includes: The guide rail is fixedly installed on the treatment frame, and its extension direction is parallel to the axis of the treatment frame; The movable support arm has one end fixedly connected to the scanning ring and the other end slidably connected to the guide rail.

[0006] In one embodiment of the present invention, the moving mechanism further includes a driving member and a transmission member, wherein the driving member drives the moving arm to move along the guide rail through the transmission system.

[0007] In one embodiment of the present invention, the scanning ring includes: The stator ring is connected to the moving mechanism; The rotor ring is rotatably mounted inside the stator ring via bearings, and the scanning imaging assembly is mounted on the rotor ring and rotates at high speed relative to the stator ring with the rotor ring.

[0008] In one embodiment of the present invention, the scanning imaging assembly includes an X-ray tube and a sector detector arranged opposite to each other.

[0009] In one embodiment of the present invention, the scanning imaging assembly further includes a high-voltage generator disposed on the rotor ring, the high-voltage generator supplying power to the scanning imaging assembly.

[0010] In one embodiment of the present invention, a control system is further included, the control system being configured to: The treatment bed is controlled to position the patient at the image acquisition location; Control the moving mechanism to drive the scanning ring to the image acquisition position; and The scanner is controlled to rotate around its own axis, and the moving mechanism is simultaneously controlled to drive the scanning ring to move along the axis of the treatment gantry and the scanning ring to complete the spiral CT scan.

[0011] In one embodiment of the present invention, the control system is further configured to, after completing the spiral CT scan, control the drive mechanism to move the scanning ring to the standby position and activate the radiotherapy assembly to irradiate the patient target area located at the treatment isocenter.

[0012] The present invention also proposes a scanning imaging system for radiotherapy equipment, comprising: A scanning ring configured to rotate about its own axis, on which a scanning imaging component for performing scanning imaging is disposed; A moving mechanism, connected to the scanning ring, is used to drive the scanning ring as a whole to move along a straight line parallel to the axis of rotation of the scanning ring; The moving mechanism is configured to drive the scanning ring to move along the scanning ring between at least a standby position located outside the treatment beam path and an image acquisition position.

[0013] The present invention also proposes a radiotherapy method, comprising: Pre-acquire and store the fixed system deviation between the image coordinate system of the scanning imaging system and the treatment coordinate system of the radiotherapy component; Move the treatment bed carrying the patient to the preset image acquisition position; The control mechanism drives the scanning ring to move along the axis of the treatment gantry and the scanning ring to the image acquisition position; The treatment bed remains fixed, while the scanning ring rotates and moves along the axis of the treatment gantry and the scanning ring, or the treatment bed rotates and moves along the axis of the treatment gantry and the scanning ring, thereby performing a spiral CT scan on the patient and acquiring CT images. Based on the registration results of the CT images and the treatment plan images, and in conjunction with the fixation system deviation, the total correction amount used to correct the patient position is calculated. The treatment bed is moved based on the total correction amount to locate the patient's target area to the treatment center; The scanning ring is driven to move to the standby position, and radiotherapy is then administered to the patient after positioning.

[0014] In one embodiment of the present invention, the pre-acquisition and storage of the fixed system deviation between the image coordinate system of the scanning imaging system and the treatment coordinate system of the radiotherapy component includes: The spatial deviation between the origin of the image coordinate system and the origin of the treatment coordinate system is measured using a calibration phantom, and this spatial deviation is represented by a six-dimensional vector V0. The six-dimensional vector V0 is stored in the control system.

[0015] In one embodiment of the present invention, the step of calculating the total correction amount for correcting the patient position based on the registration results of the CT images and the treatment planning images, and in conjunction with the fixation system deviation, includes: The three-dimensional CT images reconstructed from the scan are registered with the treatment plan images to obtain a six-dimensional deviation vector V1 that characterizes the difference between the patient's actual position and the planned position. The six-dimensional deviation vector V1 is combined with the six-dimensional vector V0 of the fixed system deviation to obtain the total correction vector V2 used to control the movement of the treatment bed.

[0016] In one embodiment of the present invention, driving the scanning ring to move to the standby position and performing radiotherapy on the positioned patient includes: After completing the position correction, control the treatment gantry to rotate to the planned treatment angle; Once the treatment gantry reaches the target angle, the radiotherapy unit is controlled to irradiate the patient.

[0017] The present invention also proposes a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the radiotherapy method as described in any of the above embodiments.

[0018] The beneficial effects of the present invention are as follows: The radiotherapy device, method and storage medium proposed in this invention achieve high-quality image guidance by integrating an axially movable diagnostic-grade fan-beam CT, thereby obtaining diagnostic-grade images with high resolution, high contrast and accurate CT values, providing a reliable image basis for precise positioning verification and dose calculation for online adaptive radiotherapy. By moving the scanning ring between the image acquisition position and the standby position, the CT components are protected from radiation damage, improving the long-term reliability of the system. It also avoids the scattering of the treatment beam by the mechanical structure, ensuring the purity and accuracy of dose delivery. Furthermore, it frees up physical space for the treatment gantry openings, which can accommodate the needs of coplanar and non-coplanar treatments, allowing the treatment bed to be positioned at a wider angle and providing ample space for movement in complex non-coplanar treatments. Scanning is achieved by the movement and rotation of the scanning ring itself, which can eliminate errors caused by the movement of the treatment bed, establish an extremely stable geometric benchmark for image registration and target positioning, and effectively improve the positioning and correction accuracy. Through integrated design, the treatment process is optimized and space is saved, the transfer of patients between equipment is avoided, errors in intermediate links are reduced, and the floor area of ​​the treatment room is significantly reduced, thus lowering construction and operating costs. Through the synergistic effect of the above technologies, this invention achieves a comprehensive improvement in the precision, efficiency, and functionality of radiotherapy, providing a complete technical foundation for efficient online adaptive radiotherapy and greatly enhancing the individualization level and clinical benefits of treatment. Attached Figure Description

[0019] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0020] In the attached diagram: Figure 1 This is a schematic diagram of the structure of a radiotherapy device with the scanning ring in the image acquisition position according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a radiotherapy device with the scanning ring in the standby position according to an embodiment of the present invention; Figure 3This is a front view of a radiotherapy device provided in an embodiment of the present invention; Figure 4 This is a cross-sectional view of a radiotherapy device provided in an embodiment of the present invention; Figure 5 This is a schematic side view cross-sectional view of a radiotherapy device with the scanning ring in the image acquisition position according to an embodiment of the present invention; Figure 6 This is a side view cross-sectional view of a radiotherapy device with the scanning ring in the standby position according to an embodiment of the present invention. Figure 7 This is a schematic diagram of the scanning ring of a radiotherapy device provided in an embodiment of the present invention; Figure 8 This is a schematic diagram showing the movement direction of the scanning ring after scanning is completed, according to an embodiment of the present invention. Figure 9 This is a schematic diagram showing the rotation direction of a treatment bed according to an embodiment of the present invention; Figure 10 A schematic diagram of a radiotherapy method provided in one embodiment of the present invention.

[0021] The attached figures are labeled as follows: 100. Treatment gantry; 200. Treatment bed; 300. Radiotherapy assembly; 400. Scanning imaging system; 500. Support rollers; 600. Six-dimensional mechanical support frame; 310. Treatment bundle; 410. Scanning ring; 411. X-ray tube; 412. Sector detector; 413. High voltage generator; 414. Accessory; 420. Moving mechanism. Detailed Implementation

[0022] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0023] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0024] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the invention. However, it will be apparent to those skilled in the art that embodiments of the invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the invention.

[0025] Radiation therapy is a common treatment for cancer. Image-guided radiotherapy aims to reduce patient positioning errors or changes in tumor location and size between or within fractions of treatment, ensuring treatment accuracy and reducing the risk of false exposure. Common image-guided radiotherapy equipment uses a cone-beam CT system mounted on a rotating gantry. The gantry rotates to acquire sufficient projections, and a reconstruction algorithm produces a 3D CT image. This 3D CT image is then registered with the CT scan used to develop the patient's treatment plan or images acquired during previous treatment phases to determine positioning errors. This error is then used to correct the patient support device. However, due to limitations in cone-beam CT imaging algorithms and flat-panel detectors, its image quality cannot compare to that of sector-beam CT used in diagnostic equipment. This limits the application of image-guided radiotherapy to basic positioning verification and prevents it from supporting adaptive radiotherapy. Using a separate treatment room with a diagnostic-grade CT requires switching the patient-carrying treatment bed between the CT scanner and the rotating gantry, increasing positioning errors and requiring a larger treatment room space, thus increasing construction and operating costs. Therefore, improving the imaging quality of image-guided radiotherapy, reducing isocentric errors in positioning, optimizing treatment procedures, and reducing space occupancy are important research directions in the field of image-guided radiotherapy.

[0026] Please see Figures 1 to 9This invention proposes a radiotherapy device, including a treatment gantry 100, a treatment bed 200, and a radiotherapy component 300 and a scanning imaging system 400 mounted on the treatment gantry 100. The radiotherapy component 300 provides a treatment beam 310, which can be X-rays, gamma rays, electron beams, proton beams, or other particle beams (e.g., helium ions, carbon ions). The treatment bed 200 is configured to carry a patient and position them at a preset image acquisition location. The scanning imaging system 400 is mounted on the treatment gantry 100 and includes a scanning ring 410 and a moving mechanism 420. The scanning ring 410 is configured to rotate around its own axis and has a scanning imaging component for performing scanning imaging. The moving mechanism 420 connects the scanning ring 410 and the treatment gantry 100 and drives the scanning ring 410 to move linearly along the axis of the treatment gantry 100 and the scanning ring 410. This invention integrates an axially movable diagnostic-grade CT scanner onto a treatment gantry 100. A moving mechanism 420 allows the scanning ring 410 to move out of the gantry, resolving the interference problem between the high-energy treatment beam 310 and the precision imaging components. It also provides sufficient rotation space for the treatment bed 200, improving the flexibility and safety of non-coplanar treatment. This achieves seamless integration of high-quality imaging and precise treatment within the same device, meeting the clinical needs of high-precision image guidance and future adaptive therapy. Through its integrated design, this invention effectively reduces the treatment room footprint and isocentric deviations introduced by patient positioning. Furthermore, its unique motion mechanism ensures that the high-precision diagnostic CT scanner, radiotherapy components, and treatment bed 200 do not interfere with each other when arranged in a limited space, thus preventing damage to the geometric accuracy of CT images, increased positioning errors, or even interference with treatment. This radiotherapy device optimizes the treatment process and reduces system errors while maintaining imaging quality. It provides a stable environment for acquiring highly accurate diagnostic-grade CT images, enhances treatment flexibility, and provides a complete technical foundation for efficient online adaptive radiotherapy, significantly improving the individualization level and clinical benefits of treatment.

[0027] Please see Figures 1 to 9In one embodiment of the present invention, the treatment gantry 100 is the core support structure of the entire radiotherapy equipment. It is designed as a cylindrical structure with a spacious interior, sufficient to accommodate the scanning imaging system 400 and the radiotherapy assembly 300. The treatment gantry 100 rests on the floor of the treatment room via multiple support rollers 500 below. Each support roller 500 includes a driving wheel driven by a servo motor and a driven wheel providing auxiliary support, together forming a rotational support system for the gantry. This system precisely rotates the entire treatment gantry 100 around its central axis, allowing the radiotherapy assembly 300 to irradiate the patient from multiple angles, achieving multi-angle radiotherapy and optimizing dose distribution. The precise control of the gantry's rotation angle by the servo motor ensures that the treatment beam 310 is accurately aligned with the patient's target area, achieving precise radiotherapy.

[0028] Please see Figures 1 to 9 In one embodiment of the present invention, the treatment gantry 100 adopts an open structural design, which facilitates the integration of the radiotherapy component 300, greatly facilitating the installation, debugging, and daily maintenance of the equipment. It effectively avoids the risk of collisions between moving parts and the treatment beam 310 or personnel, and also provides patients with a more spacious and comfortable treatment environment. The treatment bed 200 is stably supported by a support drive mechanism, such as a six-dimensional mechanical support frame 600, and can be driven to be smoothly and accurately positioned at the image acquisition position or to leave the equipment promptly after treatment. During CT imaging, the scanning ring 410 moves to the image acquisition position, allowing the patient to easily enter the scanning area; during beam therapy, the scanning ring 410 is completely withdrawn to the standby position, ensuring an unobstructed treatment path. Through the open patient interface design, combined with the mobility of the internal CT, the patient experience is improved while ensuring the safety and accuracy of the treatment.

[0029] Please see Figures 1 to 9In one embodiment of the present invention, the radiotherapy component 300 is mainly used to provide a high-energy beam (e.g., a proton beam) for radiotherapy. The radiotherapy component 300 can be a proton therapy system, which includes an accelerator for generating a high-energy beam (e.g., a proton beam), a beam transmission system for guiding the treatment beam 310, and an irradiation unit that ultimately delivers the treatment beam 310 precisely to the patient's target area. The irradiation unit is fixedly mounted on the treatment gantry 100 and rotates with the treatment gantry 100 to change the irradiation angle. During radiotherapy, the radiotherapy component 300 precisely projects the treatment beam 310 onto the tumor area in the patient's body according to a preset treatment plan, using the treatment beam 310 to achieve precise targeting of the tumor while minimizing damage to surrounding healthy tissues. The radiotherapy component 300 works in conjunction with the scanning imaging system 400. The radiotherapy component 300 only starts working after the scanning imaging system 400 completes image acquisition and retreats to a standby position, ensuring an uninterrupted and highly efficient treatment process. Understandably, because the treatment beam 310 requires extremely high irradiation accuracy, any slight geometric deviation may lead to insufficient dose to the target area or damage to surrounding normal tissues. The scanning imaging system 400 can provide diagnostic-grade precision images and ensure a high degree of consistency between the imaging and treatment coordinate systems, thus fully leveraging the advantages of radiotherapy.

[0030] Please see Figures 1 to 9 In one embodiment of the present invention, the scanning imaging system 400 is key to achieving high-precision image guidance. This system mainly includes a scanning ring 410 and a moving mechanism 420, integrated within the treatment gantry 100. The scanning ring 410 houses a diagnostic-grade fan-beam CT imaging component, capable of high-speed rotation independently of the treatment gantry 100 to acquire high-quality CT image data. The moving mechanism 420 drives the scanning ring 410 to move linearly along the rotation axis of the treatment gantry 100. During image guidance, the scanning imaging system 400 moves to the image acquisition position to perform a spiral CT scan on the patient, acquiring a high-resolution three-dimensional CT image. After the scan is completed, the moving mechanism 420 drives the scanning ring 410 to quickly retreat to the standby position, ensuring the irradiation path of the treatment beam 310 is completely unobstructed. The scanning imaging system 400 utilizes the collaborative design of the scanning ring 410 and the moving mechanism 420. The scanning ring 410 is responsible for performing high-speed and precise imaging actions, while the moving mechanism 420 provides it with spatial flexibility, enabling it to accurately position and perform spiral CT scans, guide the treatment beam 310 for radiotherapy using high-quality images, and completely avoid the treatment beam 310 while leaving sufficient treatment space.

[0031] Please see Figures 1 to 9In one embodiment of the present invention, the moving mechanism 420 is configured to drive the scanning ring 410 to move at least between an image acquisition position and a standby position; wherein, when the scanning ring 410 is in the image acquisition position, the image isocenter point coincides with the treatment isocenter point or has a preset fixed deviation; when the scanning ring 410 is in the standby position, its entirety is outside the irradiation path of the treatment beam 310. The moving mechanism 420 is the core component for realizing the axial movement of the scanning ring 410, and it can drive the scanning ring 410 to move precisely between the image acquisition position and the standby position. When the scanning ring 410 moves to the image acquisition position, its image isocenter point (i.e., the center point of the CT scan) and the treatment isocenter point of the radiotherapy component 300 (i.e., the geometric center of the treatment beam 310) are theoretically coincident, or there is only a small fixed deviation V0 between them that has been precisely preset and calibrated. x 0, y 0, z 0, α 0, β 0, γ The deviation value V0 is measured and stored in the control system beforehand using a standard phantom. As a systematic error, it can be accurately compensated in subsequent image registration and positioning correction, thereby logically achieving a high degree of uniformity between the two isocenters and ensuring precise alignment between image data and treatment plans. When the scanning ring 410 moves to the standby position, the entire scanning imaging assembly will be completely moved out of the irradiation path of the radiotherapy beam 310. During radiotherapy, it will not cause any form of obstruction, attenuation, or scattering of the treatment beam 310, thereby maximizing the integrity and dose accuracy of the treatment beam 310. At the same time, physical isolation completely avoids the risk of harmful scattered radiation from the treatment beam 310 bombarding the CT assembly, and protects the precision and expensive CT assembly from long-term radiation damage from the high-energy treatment beam 310, improving the overall reliability and lifespan of the system. With precise control of the moving mechanism 420, the scanning ring 410 can quickly and smoothly switch between image acquisition and treatment standby modes, greatly improving the efficiency and safety of the treatment process. This not only simplifies the design of the treatment beam 310 transmission system but also provides unobstructed space for a wider range of treatment angles and non-coplanar irradiation, thereby significantly enhancing the flexibility and adaptability of radiotherapy and laying the foundation for achieving true online adaptive treatment.

[0032] It should be noted that when the scanning ring 410 moves to the standby position, it moves out of the central aperture area of ​​the treatment gantry 100. This frees up significant physical space for adjusting the position of the treatment bed 200, significantly increasing its rotation angle in the horizontal plane. This allows for easy and wide-ranging positioning, giving the radiotherapy system the superior ability to perform large-angle non-coplanar irradiation. When treating tumors with complex shapes or target areas close to critical organs, the treatment bed 200 can rotate the patient to angles that conventional equipment cannot reach. This allows the treatment beam 310 to penetrate the body from more and better directions, greatly optimizing dose distribution, more effectively avoiding sensitive organs, and concentrating high-dose radiation on the tumor area. This improves treatment efficacy while maximizing the protection of surrounding healthy tissues.

[0033] Please see Figures 1 to 9 In one embodiment of the present invention, the moving mechanism 420 specifically includes a guide rail, a moving arm, a driving component, and a transmission component. The guide rail is fixedly installed on the internal structure of the treatment frame 100, and its extension direction is parallel to the axial direction of the treatment frame 100, providing a precise trajectory for the linear movement of the scanning ring 410. One end of the moving arm is fixedly connected to the scanning ring 410, and the other end is slidably connected to the guide rail. The connection between the guide rail and the moving arm can provide the rigidity and precision required for the axial movement of the scanning ring 410. The moving arm can be slidably connected to the guide rail through sliding bearings or rollers, etc., to ensure the smoothness and low friction of the scanning ring 410 during axial movement. The driving component uses the transmission component to drive the moving arm to move along the guide rail. The driving component usually adopts a high-precision servo motor, which can achieve precise control of the position of the scanning ring 410 through precise encoder feedback, ensuring that it can accurately stop at the image acquisition position and the standby position. The transmission component can be, for example, a synchronous pulley, a gear rack, or a ball screw, or other mechanisms that can achieve precise linear transmission and positioning.

[0034] Please see Figures 1 to 9 In one embodiment of the present invention, the movable support arm is symmetrically arranged on both sides of the scanning ring 410 to ensure stable support. One end of the movable support arm is fixedly connected to the side of the stator ring of the scanning ring 410, and the other end is slidably connected to the guide rail. The servo motor transmits power to the movable support arm through the belt transmission system, driving the movable support arm to drive the entire scanning ring 410 to slide smoothly and accurately along the guide rail, ensuring that the scanning ring 410 can perform high-precision axial movement while rotating at high speed, thus meeting the complex motion requirements of spiral CT scanning.

[0035] Please see Figures 1 to 9In one embodiment of the present invention, the scanning ring 410 includes a stator ring, a rotor ring, and a scanning imaging assembly mounted on the rotor ring. The stator ring is connected to the moving mechanism 420. The rotor ring is rotatably mounted inside the stator ring via bearings. The scanning imaging assembly is mounted on the rotor ring and rotates at high speed relative to the stator ring with the rotor ring. The scanning ring 410 is the core rotating component of the scanning imaging system 400. The stator ring is the outer contour structure of the scanning ring 410 and is firmly connected to the moving arm of the moving mechanism 420, thereby realizing the axial movement of the entire scanning ring 410. The rotor ring is rotatably mounted inside the stator ring via high-precision bearings, ensuring that it can rotate independently at high speed relative to the stator ring. The rotor ring is driven by an independent motor and can rotate at extremely high speed relative to the stator ring, allowing sufficient projection data to be acquired in a short time, thereby generating high-resolution, low-artifact CT images and realizing diagnostic-grade CT imaging. The precise fit between the stator and rotor, as well as the low friction and high load-bearing capacity of the bearings, ensure the stability and accuracy of the scanning imaging assembly under the combined motion of high-speed rotation and axial movement.

[0036] It should be noted that, in order to ensure dynamic balance and imaging stability under high-speed rotation, the layout of each component on the rotor ring, especially the positions of heavy components such as the X-ray tube 411 and its high-voltage generator 413, must undergo strict dynamic balance and counterweight design to ensure that the scanning ring 410 vibrates very little when rotating at high speed, thereby ensuring the geometric consistency of the projection data and thus obtaining high spatial resolution and low noise CT images.

[0037] Please see Figures 1 to 9In one embodiment of the present invention, the scanning imaging assembly is the core unit for generating and receiving X-rays to form CT images. It includes an X-ray tube 411, a sector detector 412, a high-voltage generator 413, and accessories 414, all precisely mounted on the rotor ring. The X-ray tube 411 and the sector detector 412 are mounted in pairs on the rotor ring and positioned opposite each other. The X-ray tube 411 is responsible for generating a sector-shaped beam of X-rays, and its output port is typically located at the center of the sector formed by the sector detector 412 to ensure that the X-rays uniformly cover the scanning area. The sector detector 412 consists of multiple detection units used to receive the attenuated X-ray signal after passing through the patient's body and convert it into an electrical signal. The high-voltage generator 413 is disposed on the rotor ring and is used to power the scanning imaging assembly. To maintain the performance of the scanning imaging components under high-speed rotation and high-intensity operation, necessary accessories 414 are integrated on the rotor ring, such as cooling and heat dissipation devices for the X-ray tube 411 and high-voltage generator 413, control circuit boards, and drivers. The accessories 414 are designed in synergy with the X-ray tube 411, fan-shaped detector 412, and high-voltage generator 413 to ensure the counterweight balance and rotational stability of the rotor ring during high-speed rotation, thereby avoiding vibration and imaging artifacts caused by imbalance. Through the integration of diagnostic-grade fan-beam CT, diagnostic-grade image quality with high contrast resolution and accurate CT values ​​can be provided. Physicians can quickly acquire diagnostic-grade CT images before treatment, accurately delineate the latest morphology and location of the tumor, and recalculate the dose distribution and optimize the treatment plan based on these images. The new irradiation plan is then immediately executed. The patient does not need to leave the treatment bed 200 during the entire process, thus avoiding errors introduced by secondary patient positioning and significantly shortening treatment preparation time. This online adaptive capability significantly improves the accuracy and efficiency of treatment, thereby maximizing treatment effectiveness and reducing side effects.

[0038] Please see Figures 1 to 9 In one embodiment of the present invention, the radiotherapy equipment further includes a control system responsible for coordinating and managing the operation of all components. Specifically, the control system is built on an industrial-grade computing platform and includes at least one central processing unit, non-volatile storage device, high-speed data acquisition card, and multiple dedicated motion control cards and axis controllers. This hardware establishes communication connections with the treatment bed 200, the driving components (such as servo motors) of the scanning imaging system 400, the rotary motor of the scanning ring 410, the radiotherapy components 300, and various sensors via an internal bus, forming a closed-loop control network to collaboratively complete a high-precision image-guided treatment process.

[0039] Please see Figures 1 to 9In one embodiment of the present invention, the control system is configured to: First, control the treatment bed 200 to position the patient at the image acquisition position, ensuring the patient is in the optimal scanning posture. Second, control the moving mechanism 420 to drive the scanning ring 410 smoothly and accurately from the standby position to the image acquisition position. Next, while keeping the treatment bed 200 fixed, control the scanning ring 410 to rotate around its own axis, and simultaneously control the moving mechanism 420 to drive the scanning ring 410 to move along the axis of the treatment gantry 100 and the scanning ring 410 to complete the spiral CT scan. By controlling the movement of the scanning ring 410 to perform the scan, the axial movement of the patient during the scanning process can be effectively reduced, reducing the occurrence of artifacts caused by the patient's breathing or involuntary movements, and improving image quality. After the spiral CT scan is completed, the control system will immediately control the driving mechanism to drive the scanning ring 410 to move quickly and safely to the standby position, ensuring that it is completely removed from the irradiation path of the treatment beam 310. Finally, the control system activates the radiotherapy assembly 300 to perform irradiation treatment on the patient target area located at the treatment isocenter. Through the coordinated operation of the control system, seamless connection is achieved between various components, ensuring that the entire process from image acquisition to treatment implementation is efficient, safe, and precise, ensuring the consistency and ultra-high precision of treatment, and greatly improving the quality of treatment and patient comfort.

[0040] Please see Figures 1 to 9 In another embodiment, the control system is configured to control the moving mechanism 420 to drive the scanning ring 410 to the image acquisition position, and then control the scanning ring 410 to rotate around its own axis. At the same time, the six-dimensional mechanical support frame 600 is controlled to drive the treatment bed 200 to move along the axis. The two work together to complete the spiral CT scan.

[0041] Please see Figures 1 to 9The present invention also proposes a scanning imaging system 400 for a radiotherapy device, including a scanning ring 410 and a moving mechanism 420. The scanning ring 410 is configured to rotate about its own axis and is provided with a scanning imaging component for performing scanning imaging. The moving mechanism 420 is connected to the scanning ring 410 and is used to drive the scanning ring 410 as a whole to move along a straight line parallel to the rotation axis of the scanning ring 410. The moving mechanism 420 is configured to drive the scanning ring 410 to move between at least a standby position located outside the path of the treatment beam 310 and an image acquisition position. This system possesses dynamic obstacle avoidance capabilities, significantly improving the lifespan of core components and system reliability. It also purifies the irradiation environment of the treatment beam 310, ensuring image quality while resolving inherent interference between imaging and treatment components. Flexible standby positioning allows sufficient space for the treatment bed 200, facilitating complex-angle radiotherapy and enhancing treatment flexibility. Furthermore, the high-speed rotation capability of the scanning ring 410, combined with the high-precision linear drive provided by the moving mechanism 420, enables the system to independently complete standard spiral CT scans while the treatment bed 200 and its patient remain completely stationary. This fundamentally eliminates vibration and deformation error sources caused by the movement of the treatment bed 200, providing crucial assurance for acquiring high-geometric-accuracy, low-motion-artifact diagnostic CT images. The scanning imaging system 400 can be integrated into radiotherapy equipment (such as a radiotherapy gantry or an electron linear accelerator gantry). Its simple structure facilitates installation, calibration, and maintenance, greatly simplifying the overall design and manufacturing process and providing a feasible technical path for upgrading existing treatment centers.

[0042] Please see Figures 1 to 10 The present invention also proposes a radiotherapy method, comprising: S100: Pre-acquire and store the fixed system deviation between the image coordinate system of the scanning imaging system 400 and the treatment coordinate system of the radiotherapy component 300; S200: Move the treatment bed 200 carrying the patient to the preset image acquisition position; S300, the control moving mechanism 420 drives the scanning ring 410 to move along the axis of the treatment frame 100 and the scanning ring 410 to the image acquisition position; S400 and treatment bed 200 remain fixed. While the scanning ring 410 performs a rotational motion, it moves along the axis of the treatment gantry 100 and the scanning ring 410. Alternatively, while the scanning ring 410 performs a rotational motion, the treatment bed 200 moves along the axis of the treatment gantry 100 and the scanning ring 410, thereby performing a spiral CT scan on the patient and acquiring CT images. S500: Based on the registration results of CT images and treatment plan images, and combined with the fixed system bias, calculates the total correction amount used to correct the patient position. S600, based on the total correction value, the mobile treatment bed 200, locates the patient's target area to the treatment center; S700 drives the scanning ring 410 to move to the standby position and performs radiotherapy on the positioned patient.

[0043] Please see Figures 1 to 10 In one embodiment of the present invention, step S100 includes: The spatial deviation between the origin of the imaging coordinate system and the origin of the treatment coordinate system is measured using a calibration phantom, and this spatial deviation is represented by a six-dimensional vector V0. The six-dimensional vector V0 is stored in the control system.

[0044] Please see Figures 1 to 10 In one embodiment of the present invention, system calibration and initialization are performed in step S100. Specifically, this can be performed before the equipment is put into use or during regular maintenance. A dedicated calibration phantom is precisely fixed onto the treatment bed 200, and a complete scanning and treatment coordinate matching program is run. The control system drives the scanning imaging system 400 to scan the phantom and compares the scan results with the known standard spatial coordinates of the phantom to accurately calculate the spatial deviation between the origin of the image coordinate system of the scanning imaging system 400 and the origin of the treatment coordinate system of the radiotherapy component 300. This deviation is expressed as a six-dimensional vector V0 containing three translational components and three rotational components. x 0, y 0, z 0, α 0, β 0, γ 0) represents the coordinates and is permanently stored in the non-volatile memory of the control system. The fixed system deviation parameters established in this step provide a precise reference for coordinate transformations in all subsequent treatment processes, fundamentally ensuring the intrinsic consistency between the image space and the treatment space.

[0045] Please see Figures 1 to 10In one embodiment of the present invention, imaging positioning preparation is performed through step S200. The operator selects the treatment plan for the target patient on the control interface, and the system automatically loads the irradiation angle, dose parameters, and preset image acquisition position coordinates. The patient enters the treatment room and, with the assistance of medical staff, lies on the treatment bed 200 in a highly repeatable posture. The treatment bed 200 first automatically adjusts its supporting surface to the patient's preset posture. Subsequently, the treatment gantry 100 rotates to the 0° mechanical reference position and locks, establishing a unified orientation reference. Finally, the treatment bed 200 automatically moves the patient's target area and precisely positions it to the preset image acquisition position according to the planned coordinates. This series of preparation steps ensures that the patient is in a known and repeatable initial state at the start of each treatment.

[0046] Please see Figures 1 to 10 In one embodiment of the present invention, a spiral CT scan is performed in step S400. After the control system instructs the moving mechanism 420 to move the scanning ring 410 to the image acquisition position, while keeping the treatment bed 200 stationary, the system simultaneously initiates two movements of the scanning ring 410: high-speed continuous rotation around its own axis and uniform linear movement along the rotation axis of the treatment gantry 100 via the moving mechanism 420. Through the precise synthesis of these two movements, spiral CT data acquisition of the patient in a stationary state is achieved. The projection data is transmitted to the reconstruction computer in real time, and high-quality three-dimensional CT images are generated through filtered back projection or iterative reconstruction algorithms. By keeping the treatment bed 200 fixed, axial movement of the patient during the scan is avoided, effectively reducing artifacts caused by the patient's breathing or involuntary movements, and effectively eliminating minor vibrations, deformations, and positional uncertainties that may occur when the bed moves under heavy loads. This results in higher quality diagnostic-grade CT images with fewer artifacts, providing image source data with extremely high geometric accuracy for image registration.

[0047] Please see Figures 1 to 10 In another embodiment of the present invention, in step S400, the axial position of the scanning ring 410 can also be kept unchanged, and spiral CT data acquisition can be achieved by coordinating its own rotation with the axial movement of the treatment bed 200.

[0048] Please see Figures 1 to 10 In one embodiment of the present invention, step S500 includes: The three-dimensional CT images reconstructed from the scan are registered with the treatment plan images to obtain a six-dimensional deviation vector V1 that characterizes the difference between the patient's actual position and the planned position. The six-dimensional deviation vector V1 is combined with the six-dimensional vector V0 of the fixed system deviation to obtain the total correction vector V2 used to control the movement of the treatment bed 200.

[0049] Please see Figures 1 to 10In one embodiment of the present invention, after the scan is completed, position deviation calculation and synthesis are performed in step S500. Specifically, the image processing unit of the control system automatically registers the three-dimensional CT image acquired and reconstructed in step S400 with a pre-defined reference image in the treatment planning system. The registration algorithm, based on image grayscale information or anatomical feature points, accurately calculates the six-dimensional positioning deviation vector V1 caused by the patient's positioning and physiological changes on that day. x 1, y 1, z 1, α 1, β 1, γ 1) Subsequently, the processor performs vector synthesis, adding the real-time positioning deviation V1 to the pre-stored system fixed deviation V0 to obtain the total correction vector V2 that the treatment bed 200 needs to execute, where V2 = V1 + V0. This synthesis calculation compensates for the patient's random positioning error and the inherent system error of the equipment, achieving a high degree of consistency between the logical treatment isocenter and the image isocenter, laying the foundation for subsequent precise irradiation.

[0050] Please see Figures 1 to 10 In one embodiment of the present invention, in step S600, the control system drives the six-dimensional motion mechanism of the treatment bed 200 according to the calculated total correction vector V2. The treatment bed 200 automatically performs fine adjustments in three translational degrees of freedom and three rotational degrees of freedom, ultimately accurately moving and positioning the patient's tumor target area to the physical therapy center. Since the treatment bed 200 was stationary during the previous scanning phase, the position correction at this time does not need to compensate for historical errors caused by the movement of the bed during scanning, thus significantly improving the accuracy and reliability of this correction.

[0051] Please see Figures 1 to 10 In one embodiment of the present invention, step S700 includes: After completing the position correction, control the treatment gantry 100 to rotate to the planned treatment angle; Once the treatment gantry 100 reaches the target angle, the radiotherapy unit 300 is controlled to irradiate the patient.

[0052] Please see Figures 1 to 10In one embodiment of the present invention, specifically in step S700, after confirming that the patient's position is correctly correct, the control system first instructs the moving mechanism 420 to move the scanning ring 410 to the standby position, ensuring that all its components are completely removed from the envelope space of the treatment beam 310 and leaving sufficient space for the treatment bed 200. Subsequently, the locking of the treatment gantry 100 is released, and it rotates to the first irradiation angle θ1 specified in the treatment plan. The radiotherapy component 300 accurately irradiates the target area at this angle according to the planned parameters. After the irradiation at this angle is completed, the treatment gantry 100 rotates to the next treatment angle θ2, and the irradiation process is repeated until all planned angles of treatment are completed. The overall removal and avoidance of the scanning ring 410 completely avoids radiation damage to the CT component from the high-energy treatment beam 310, and also eliminates the risk of scattering interference from the mechanical structure to the irradiation field, ensuring the accuracy of dose delivery and the long-term reliability of the system.

[0053] Please see Figures 1 to 10 In one embodiment of the present invention, before each irradiation, the control system determines whether the treatment bed 200 needs to be rotated non-coplanarly. If so, it controls the treatment gantry 100 to rotate to a safe transition angle, and then instructs the treatment bed 200 to rotate a specific preset angle in the horizontal plane. Since the scanning ring 410 is in standby position, the rotation of the treatment bed 200 is not hindered by any mechanical means, allowing for a wide range of free adjustments. After the treatment bed 200 has rotated to its position, the treatment gantry 100 rotates to the next treatment angle, forming an optimal non-coplanar irradiation geometry in conjunction with the rotation angle of the treatment bed 200, achieving a better irradiation path. Subsequently, the radiotherapy component performs irradiation at this angle. It has a highly flexible non-coplanar treatment capability. After completing irradiation at all preset angles, the treatment bed 200 returns to its initial position, and then the patient is removed from the treatment space. The treatment process ends, and the patient leaves safely.

[0054] Please see Figures 1 to 10 The present invention also proposes a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the radiotherapy method as described in any of the above embodiments.

[0055] In summary, the radiotherapy device, method, and storage medium of the present invention significantly improve the imaging quality of image-guided radiotherapy by integrating a diagnostic-grade sector-beam CT (i.e., scanning ring 410) that can move axially and completely avoid obstacles; the movement mechanism 420 drives the scanning ring 410 to achieve obstacle avoidance, improving the flexibility and safety of treatment; the movement and rotation of the scanning ring 410 realizes helical CT scanning, effectively eliminating potential error sources and improving imaging accuracy; and through a high-precision workflow of coordinated optimization of various systems, breakthroughs have been achieved in the accuracy, reliability, and clinical function of image-guided radiotherapy. While ensuring high-precision treatment, the patient experience is optimized, space occupation is reduced, and a solid technical foundation is provided for online adaptive radiotherapy.

[0056] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

[0057] Throughout this description, numerous specific details, such as examples of components and / or methods, are provided to provide a complete understanding of embodiments of the invention. However, those skilled in the art will recognize that embodiments of the invention may be practiced without one or more of these specific details or by other devices, systems, components, methods, parts, materials, components, etc. In other instances, well-known structures, materials, or operations have not been specifically shown or described in detail to avoid obscuring aspects of embodiments of the invention.

[0058] Throughout this specification, the terms "an embodiment," "embodiment," or "specific embodiment" refer to a particular feature, structure, or characteristic described in connection with an embodiment that is included in at least one embodiment of the invention, but not necessarily in all embodiments. Therefore, the various representations of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout the specification do not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic of any specific embodiment of the invention can be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the embodiments of the invention described and illustrated herein may be based on the teachings herein and will be considered part of the spirit and scope of the invention.

[0059] It should also be understood that one or more of the elements shown in the figures may be implemented in a more separate or more integrated manner, or may even be removed because they are inoperable in certain circumstances or provided because they may be useful for a particular application.

[0060] Furthermore, unless otherwise expressly stated, any arrows in the accompanying drawings should be considered illustrative only and not limiting. Additionally, unless otherwise stated, the term "or" as used herein is generally intended to mean "and / or". Where a term is anticipated to provide a separation or combination capability that is unclear, a combination of components or steps will also be considered as indicated.

[0061] As used herein and throughout the claims below, unless otherwise specified, “a” and “the” include the plural references. Similarly, as used herein and throughout the claims below, unless otherwise specified, “in” means “in” and “on”.

[0062] The above description of the embodiments shown in this invention (including the content set forth in the abstract of the specification) is not intended to be an exhaustive enumeration or to limit the invention to the precise forms disclosed herein. Although specific embodiments and examples of the invention have been described herein for illustrative purposes only, various equivalent modifications are possible within the spirit and scope of the invention, as will be recognized and understood by those skilled in the art. As indicated, these modifications can be made to the invention in accordance with the above description of the embodiments described herein, and such modifications will be within the spirit and scope of the invention.

[0063] This document has generally described the systems and methods in detail to aid in understanding the invention. Furthermore, various specific details have been set forth to provide a general understanding of embodiments of the invention. However, those skilled in the art will recognize that embodiments of the invention can be practiced without one or more specific details, or using other means, systems, accessories, methods, components, materials, parts, etc. In other instances, well-known structures, materials, and / or operations have not been specifically shown or described in detail to avoid obscuring aspects of embodiments of the invention.

[0064] Therefore, although the invention has been described herein with reference to specific embodiments thereof, freedom of modification, various changes and substitutions are also within the scope of the foregoing disclosure, and it should be understood that in some cases, certain features of the invention may be adopted without departing from the scope and spirit of the invention and without corresponding use of other features. Thus, many modifications can be made to adapt a particular environment or material to the essential scope and spirit of the invention. The invention is not intended to be limited to the specific terminology used in the following claims and / or the specific embodiments disclosed as the best mode for carrying out the invention, but the invention will include any and all embodiments and equivalents falling within the scope of the appended claims. Therefore, the scope of the invention will be defined only by the appended claims.

Claims

1. A radiotherapy device, characterized in that, include: A treatment gantry, on which a radiotherapy unit is mounted to provide the treatment beam; The treatment bed is configured to accommodate the patient and position them at a preset image acquisition location; A scanning imaging system, mounted on the treatment gantry, includes: A scanning ring configured to rotate about its own axis, on which a scanning imaging component for performing scanning imaging is disposed; A moving mechanism, connecting the scanning ring and the treatment gantry, is configured to drive the scanning ring to move at least between an image acquisition position and a standby position; When the scanning ring is in the image acquisition position, the image isocenter point is consistent with the treatment isocenter point or has a preset fixed deviation. When the scanning ring is in the standby position, its entirety is located outside the irradiation path of the treatment beam.

2. The radiotherapy device according to claim 1, characterized in that, The moving mechanism includes: The guide rail is fixedly installed on the treatment frame, and its extension direction is parallel to the axis of the treatment frame; The movable support arm has one end fixedly connected to the scanning ring and the other end slidably connected to the guide rail.

3. The radiotherapy device according to claim 2, characterized in that, The moving mechanism further includes a driving component and a transmission component, wherein the driving component drives the moving arm to move along the guide rail through the transmission system.

4. The radiotherapy device according to claim 1, characterized in that, The scanning ring includes: The stator ring is connected to the moving mechanism; The rotor ring is rotatably mounted inside the stator ring via bearings, and the scanning imaging assembly is mounted on the rotor ring and rotates at high speed relative to the stator ring with the rotor ring.

5. The radiotherapy device according to claim 4, characterized in that, The scanning imaging assembly includes an X-ray tube and a sector detector arranged opposite each other.

6. The radiotherapy device according to claim 5, characterized in that, The scanning imaging assembly also includes a high-voltage generator disposed on the rotor ring, which supplies power to the scanning imaging assembly.

7. The radiotherapy device according to claim 1, characterized in that, It also includes a control system, which is configured to: The treatment bed is controlled to position the patient at the image acquisition location; Control the moving mechanism to drive the scanning ring to the image acquisition position; and The scanner is controlled to rotate around its own axis, and the moving mechanism is simultaneously controlled to drive the scanning ring to move along the axis of the treatment gantry and the scanning ring to complete the spiral CT scan.

8. The radiotherapy device according to claim 7, characterized in that, The control system is also configured to, after completing the spiral CT scan, control the drive mechanism to move the scanning ring to the standby position and activate the radiotherapy assembly to irradiate the patient target area located at the treatment isocenter.

9. A scanning imaging system for radiotherapy equipment, characterized in that, include: A scanning ring configured to rotate about its own axis, on which a scanning imaging component for performing scanning imaging is disposed; A moving mechanism, connected to the scanning ring, is used to drive the scanning ring as a whole to move along a straight line parallel to the axis of rotation of the scanning ring; The moving mechanism is configured to drive the scanning ring to move along the scanning ring between at least a standby position located outside the treatment beam path and an image acquisition position.

10. A radiotherapy method, characterized in that, include: Pre-acquire and store the fixed system deviation between the image coordinate system of the scanning imaging system and the treatment coordinate system of the radiotherapy component; Move the treatment bed carrying the patient to the preset image acquisition position; The control mechanism drives the scanning ring to move along the axis of the treatment gantry and the scanning ring to the image acquisition position; The treatment bed remains fixed, while the scanning ring rotates and moves along the axis of the treatment gantry and the scanning ring, or the treatment bed rotates and moves along the axis of the treatment gantry and the scanning ring, thereby performing a spiral CT scan on the patient and acquiring CT images. Based on the registration results of the CT images and the treatment plan images, and in conjunction with the fixation system deviation, the total correction amount used to correct the patient position is calculated. The treatment bed is moved based on the total correction amount to locate the patient's target area to the treatment center; The scanning ring is driven to move to the standby position, and radiotherapy is then administered to the patient after positioning.

11. The radiotherapy method according to claim 10, characterized in that, The fixed system deviation between the image coordinate system of the pre-acquired and stored scanning imaging system and the treatment coordinate system of the radiotherapy component includes: The spatial deviation between the origin of the image coordinate system and the origin of the treatment coordinate system is measured using a calibration phantom, and this spatial deviation is represented by a six-dimensional vector V0. The six-dimensional vector V0 is stored in the control system.

12. The radiotherapy method according to claim 10, characterized in that, The total correction amount used to correct the patient's position, calculated based on the registration results of the CT images and the treatment plan images, and in conjunction with the fixation system deviation, includes: The three-dimensional CT images reconstructed from the scan are registered with the treatment plan images to obtain a six-dimensional deviation vector V1 that characterizes the difference between the patient's actual position and the planned position. The six-dimensional deviation vector V1 is combined with the six-dimensional vector V0 of the fixed system deviation to obtain the total correction vector V2 used to control the movement of the treatment bed.

13. The radiotherapy method according to claim 10, characterized in that, The process of driving the scanning ring to the standby position and performing radiotherapy on the positioned patient includes: After completing the position correction, control the treatment gantry to rotate to the planned treatment angle; Once the treatment gantry reaches the target angle, the radiotherapy unit is controlled to irradiate the patient.

14. A computer-readable storage medium, characterized in that, It stores a computer program thereon, which, when executed by a processor, implements the radiotherapy method as described in any one of claims 10 to 13.

Images