KR20130134200A - Robot system for radiation cancer treatment - Google Patents

Abstract

The present invention relates to a robot system which irradiates a lesion of a patient by radiation beams within an operation region (12) around a bed (10). The robot system comprises: a base (20) installed at a ceiling and/or a floor; an arm (30) installed to support a linear accelerator (15) on the base (20) for multi-axis motion; a sensor unit (40) to detect the output change of radiation beam and position change of a patient; and a control unit (50) to operate the arm with a predetermined condition while inputting signals of the sensor unit (40). Therefore, radiation therapy time can be reduced using a plurality of robot arms which are cooperatively controlled, and accuracy is improved using the degree of freedom in sensitive areas such as pancreas and brain for enabling microsurgery.

Description

Robot system for radiation cancer treatment

The present invention relates to a robot system for the treatment of radiation cancer, and more specifically, to reduce the radiation treatment time due to the cooperatively controlled multiple robot arms, and to improve the elaboration using the degree of freedom for sensitive areas such as the pancreas and the brain. The present invention relates to a radiation cancer treatment robot system that enables microsurgery.

X-Knife (Radionics, USA), Novalis Tx (BrainLAB, Germany), Peacok (NOMOS Corp, USA), Trilogy (Varian Medical System, USA), CyberKnife (Accuray Inc. USA) are known as equipment related to radiation therapy. Most of them are evolving to reduce errors and increase accuracy based on the technology of linear accelerator and image guided radiotherapy (IGRT). CyberKnife of the equipment can implement the treatment to complement the tumor movement caused by the patient's breathing.

On the other hand, research on robots of radiation cancer treatment equipment (systems) is inadequate. In general, the design process of robot kinematics greatly reduces the degree of freedom (DOF) design, type design, and dimensions. Although the description is divided into dimension designs, there is no mention of a task analysis process that must precede the design process of robot kinematics. In particular, no research has been conducted on topics related to the construction of stereotactic radiosurgery using multiple robotic arms.

As related domestic and foreign prior patents, Korean Patent Laid-Open Publication No. 1995-9003890 moves a robotic arm and a beam generator along a predetermined non-circular and nonlinear path traversing a beam path and simultaneously directs the beam path into a target area. A device for radiation therapy using a means of the present invention, US Patent Publication No. 2009/0003523 proposes an image-guided radiation therapy system comprising a robot positioning system and a tracking system, US Patent Publication No. 2009/0003975 The arc proposes a robot arm of a radiation treatment system comprising a linear accelerator and a robot arm of five degrees of freedom according to the linear accelerator, US Patent No. 7724870 is a support of at least four degrees of freedom, a therapeutic radiation source coupled to the support, A digital tomosynthesis is proposed in chiropractic radiosurgery that includes a detector.

However, according to the above-mentioned patent, it is difficult to treat the moving parts such as lung cancer due to the time-consuming procedure due to the linear trace amount of radiation, and especially surrounded by important organs such as pancreatic cancer or brain cancer, If vulnerable, the treatment reveals limitations.

An object of the present invention for improving the conventional problems as described above, by reducing the radiotherapy time due to the cooperatively controlled multiple robot arms, by improving the elaboration using the degree of freedom for sensitive areas such as pancreas and brain The present invention provides a robotic system for the treatment of radiation cancer that enables microsurgery.

Another object of the present invention is to improve the safety of the robot system by preventing mutual collisions by applying a plurality of radiation irradiator.

In order to achieve the above object, the present invention provides a robot system for performing cancer treatment by irradiating a radiation beam to the affected part of the patient in the work area centered on the bed: a base installed on at least one side of the ceiling and the floor; An arm installed on the base to support the multi-axis motion in a linear accelerator; Sensing means for detecting an output variation of the radiation beam and a position variation of the affected part; And a controller for driving the arm under the set condition while inputting the signal of the sensing means.

In addition, according to the present invention, the arm is based on the first to sixth axes constituted by the rotating shaft, and the seventh axis formed by the linear axis to secure the margin of freedom.

In addition, according to the present invention, the arm is installed including two places of the ceiling and optionally two places of the floor, characterized in that the maximum spaced apart from each other at the vertex of the square area in plan view.

In addition, according to the present invention, the sensing means may include a pin diode and a MOSFET radiation detection sensor, and a stereo camera for tracking the position of the affected part through a marker. do.

In addition, according to the present invention, the controller comprises a position tracking unit for acquiring three-dimensional coordinates of the affected area using signals of the sensing means, a cooperative processing unit for allocating division of labor to each arm in response to the signal of the position tracking unit, It is characterized in that it comprises a collision prevention unit for generating an alarm with an emergency stop in anticipation of the collision of the arm.

In this case, the collision avoidance unit of the controller is characterized in that to apply the algorithm of the close point of approach (CPA) measurement method between the neighboring arms.

In addition, according to the present invention, the controller further comprises a beam control unit for varying the energy of the radiation beam of the linear accelerator.

As described above, according to the present invention, it is possible to shorten the radiation treatment time due to the cooperatively controlled robot arms, and to improve the elaboration using the degree of freedom for sensitive areas such as the pancreas and the brain, thereby enabling microsurgery. have.

1 is a perspective view showing the main configuration of the robot system according to the present invention
Figure 2 is a plan view showing the arm arrangement of the robot system according to the present invention
Figure 3 is a side view showing the arm arrangement of the robot system according to the present invention
Figure 4 is a block diagram showing a controller connection state of the robot system according to the present invention
5 is an exemplary view showing a simulation program screen of the controller of FIG.
6 is an exemplary diagram illustrating some algorithms of the controller of FIG. 4.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention relates to a robotic system for performing cancer treatment by irradiating a beam of radiation to the affected part of the patient in the work area 12 centered on the bed 10. As an example of such a robotic system, CyberKnife eliminates the fixing frame on the bed 10 by using image tracking technology to reduce patient discomfort and shorten the time required for treatment. The present invention is invented in the necessity of combining a technology for shortening the long treatment time, which is the weakest point of cyberknife, with the real-time tumor tracking system technology, which is the greatest strength of cyberknife. The bed 10 is configured to allow multi-axis movement in consideration of the patient's ease of boarding and the accuracy of treatment, but excludes other configurations for restraining the movement of the patient. The work area 12 means a position at which an end of the linear accelerator 15 provided at the end of the arm 30 to be described later passes.

According to the present invention, the base 20 is installed on at least one side of the ceiling and the floor. The base 20 is selected to a position where the arm 30 of the robot, which will be described later, can quickly change to a posture set in the work area 12 while avoiding obstacles. In terms of obstacle avoidance and space utilization, the position of the base 20 is preferably ceiling rather than floor, but is not necessarily limited thereto. For example, the base 20 and the arm 30 installed on the floor may implement an upward beam function irradiated to the back of the patient.

In addition, according to the present invention, the arm 30 is installed on the base 20 so as to support the linear accelerator 15 in a multi-axial motion. In the kinematic design of the robot, the degrees of freedom associated with the arm 30, the shape of the joint, the length of the link, and the like are important factors. The linear accelerator 15 is a device for generating radiation for treatment, and is installed at the end of the arm 30, and determines a 'task point' corresponding to the position and direction to be passed while performing a task. to be. As an example of the CyberKnife system, the work point was found to be about 0.4 m long.

At this time, the arm 30 is based on the first axis (31) to the sixth axis (36) consisting of a rotating shaft, by connecting the seventh axis (37) consisting of a linear axis to secure a degree of freedom. In determining the kinematic solution of the robot that can satisfy the work area 12, the degree of freedom of each robot arm must be preceded. Two degrees of freedom in the pitch and yaw directions for three degrees of freedom for the orientation of the X, Y and Z positions of the linear accelerator 15 within the work area 12 in relation to the disease tracking and treatment operations. On the other hand, the roll direction requires at least five degrees of freedom because it is relatively less important in any direction, but according to the present invention, one arm is added by adding one degree of freedom. It is preferable to have six degrees of freedom by the first axis 31 to the sixth axis 36. When the first axis 31 to the sixth axis 36 are configured on the arm 30 in this manner, the posture of any position or direction is covered while covering the large work area 12 in a relatively small installation space such as a vertical articulated robot. Nevertheless, high speeds can be achieved.

In addition, in the present invention, the seventh axis 37 is provided on the arm 30 to implement a degree of freedom. The first axis 31 to the sixth axis 36 are all configured as a rotation axis, while the seventh axis 37 is configured as a linear axis. Such a degree of freedom may be sufficient from the point of view of increasing the robot's work ability (dexterity) in performing the same task, but the amount of the degree of freedom increases the difficulty of control in design and mass production. In terms of disadvantage. According to the present invention, additional tasks (e.g., joint space limitation avoidance, singular point avoidance, collision avoidance) are realized by utilizing the degree of freedom while performing a given task using the first axis 31 to the sixth axis 36. .

On the other hand, the arm 30 of the present invention is installed including two places of the ceiling and optionally two places of the floor, and are spaced apart from each other at the vertices of the square region in plan view. In FIG. 2, the arm 30 of the ceiling, the arm 30 of the floor, the arm 30 of the ceiling, and the arm 30 of the floor are alternately disposed with respect to the square area centered on the work area 12 in FIG. 2. Indicates. When the arm 30 of the ceiling and the arm 30 of the floor are close to each other, the posture is as shown in FIG. 3. According to this arrangement method, the risk of collision between the arms 30 is reduced. The arm 30 of the ceiling accesses the upper hemispherical work area 12 and the arm 30 of the bottom accesses the lower hemispherical work area 12. Of course, the increase in the number of installation of the arm 30 is advantageous in terms of increasing the speed and accuracy of treatment, but in consideration of economics can be eclectically selected according to the application within the total four ranges.

In addition, according to the present invention, the sensing means 40 detects the output variation of the radiation beam and the position variation of the affected part. The sensing means 40 includes a radiation detection sensor 42 and a stereo camera 45 as main components. In order to improve the quality of treatment for various lesions (tumors), a sensor device for measuring the energy of the radiation beam with high resolution is required, and various external factors that may be caused by the patient's breathing and other occurrences to track the lesion in three dimensions. You must detect the movement (movement) caused by.

The radiation detection sensor 42 of the present invention uses a pin diode and a MOS field effect transistor (MOSFET). The radiation detection sensor 42 preferably adopts a semiconductor type which has the advantages of sealing waterproofing and miniaturization. The pin diode is applied to the measurement of fast neutrons, and the MOSFET is applied to the gamma ray measurement. In the latter case, NMRC's pMOSFET can be used. Since the radiation detection sensor 42 has a characteristic of storing the radiation dose itself, it is possible to measure the radiation dose with only the sensor without the addition of an external circuit.

The stereo camera 45 of the present invention is applied in a manner to track the position of the affected part through a marker. This corrects the left and right stereo cameras 45, obtains left and right images of the patient (the affected part) to be restored, finds mutual correspondence points in the acquired images, and uses the geometric relationship between the same points and the left and right stereo cameras 45. To restore the patient in three dimensions. For example, a marker that can be easily distinguished by an image is installed on the outer periphery of the patient, and an Otsu method may be employed to distinguish the marker after acquiring an image of the marker.

Further, according to the present invention, the controller 50 drives the arm 30 under the set condition while inputting the signal of the sensing means 40. The controller 50 stores algorithms and data related to the control and management of the bed 10, the arm 30, and the sensing means 40 in the system memory, and externally integrates the patient-specific treatment plan and the treatment progress. It is associated with a management system (not shown). In addition, the controller 50 is based on a GUI that graphically represents important information on the display.

More specifically, the controller 50 uses the signal of the sensing means 40 to obtain the three-dimensional coordinates of the affected part, the position tracking unit 52 and the respective arms corresponding to the signal of the position tracking unit 52. And a cooperative processing unit 54 for allocating division of labor to 30, and a collision preventing unit 56 for generating an alarm with an emergency stop in anticipation of the collision of each arm 30. The position tracking unit 52 tracks the movement of the affected part of the patient in three dimensions based on the information generated using the marker and the stereo camera 45 and outputs it on the display. The cooperative processing unit 54 outputs kinematic variables (Position, Orientation, Jacobian) through rotation of the first axis 31 to the sixth axis 36, and individually or cooperates with the arm 30 according to the set algorithm. Assign division of labor with. The collision preventing part 56 utilizes the seventh axis 37 in addition to the first axis 31 to the sixth axis 36 which do not have a degree of freedom that can be avoided by itself, and gives priority to neighboring arms 30. To stop the lower priority arm 30. 5 illustrates a portion of a program that simulates such cooperative control.

는 로봇 아암(30)의 이웃하는 링크(link_i와 link_{i +1}) 사이의 벡터이다. 이와 같이 충돌방지부(56)는 아암(30) 사이의 최소 거리를 측정하고 충돌을 예상할 경우 경보를 발생할 수도 있다.In this case, the collision preventing unit 56 of the controller 50 applies an algorithm of a close point of approach (CPA) measurement method between the neighboring arms 30. 6 illustrates a principle and an algorithm for measuring the shortest distance between links of two robot arms 30. In the above algorithm

Is a vector between neighboring links (link _i and link _{i +1} ) of the robot arm (30). As such, the collision avoidance unit 56 may measure the minimum distance between the arms 30 and generate an alarm when anticipating a collision.

On the other hand, the controller 50 further includes a beam control unit 58 for varying the energy of the radiation beam of the linear accelerator 15. Although the beam energy available in the conventional cyberknife is only 6 MV, the beam control unit 58 of the present invention has a low energy for tumors located near the skin (for example, 4 MV), and a high energy for tumors located deep in the body (for example, 10 MV, 15MV, 20MV) is implemented variably. Accordingly, the quality of treatment can be improved in response to various treatment sites.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention as defined by the appended claims. It is therefore intended that such variations and modifications fall within the scope of the appended claims.

10: bed 12: working area
15: linear accelerator 20: base
30: arm 31-36: 1st axis-6th axis
37: 7th axis 40: sensing means
42: radiation detection sensor 45: stereo camera
50: controller 52: position tracking unit
54: cooperative processing unit 56: collision prevention unit
58: beam control unit

Claims (7)

In a robotic system for performing cancer treatment by irradiating a beam of radiation to the affected part of a patient in a work area 12 centered on the bed 10:
A base 20 installed on at least one side of the ceiling and the floor;
An arm 30 installed on the base 20 so as to support the linear accelerator 15 in a multi-axial motion;
Sensing means (40) for detecting an output variation of the radiation beam and a position variation of the affected part; And
And a controller (50) for driving the arm (30) in a set condition while inputting the signal of the sensing means (40). The method of claim 1,
The arm 30 is based on the first axis (31) to the sixth axis (36) consisting of a rotating shaft, the radiation is characterized in that the margin of freedom by connecting the seventh axis (37) consisting of a linear axis Robot system for cancer treatment. The method of claim 1,
The arm 30 is installed, including two places of the ceiling and optionally two places of the floor, the radioactive cancer treatment robot system, characterized in that spaced apart from each other at the vertices of the square area in a plan view. The method of claim 1,
The sensing means 40 includes a pin diode and a MOSFET radiation detection sensor 42 and a stereo camera 45 for tracking the affected part via a marker. Robot system for radiation cancer treatment, characterized in that. The method of claim 1,
The controller 50 uses the signal of the sensing means 40 to acquire the three-dimensional coordinates of the affected part, and the arm 30 corresponding to the signal of the location tracker 52. And a collision prevention unit (56) for allocating division of labor and an anti-collision unit (56) for generating an alarm with an emergency stop in anticipation of the collision of each arm (30). The method of claim 5,
The anti-collision unit 56 of the controller 50 is a radiation cancer treatment robot system, characterized in that for applying the algorithm of the close point of the Approach (CPA) measuring method between neighboring arms (30). The method of claim 1,
The controller (50) further comprises a beam control unit (58) for varying the energy of the radiation beam of the linear accelerator (15).

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