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CN-121994102-A - Device for detecting precision of radiotherapy bed

CN121994102ACN 121994102 ACN121994102 ACN 121994102ACN-121994102-A

Abstract

The invention belongs to the technical field of medical appliances, and particularly discloses a device for detecting the precision of a radiotherapy bed. The test block is provided with a measuring surface with scale marks and through holes, the laser lamp group emits laser beams to the measuring surface, and the position deviation of the treatment couch is judged through the relative positions of the laser beams, the scale marks and the through holes. The device can realize quick and visual calibration and precision detection, and in addition, the device also integrates a photoelectric sensor and a processing unit, thereby realizing automatic quantitative measurement and deviation compensation.

Inventors

  • XU LI
  • BAI XUE
  • ZHU JI
  • WANG BINBING
  • LIU JIPING
  • WANG HANLIN
  • LUO CHANGLI

Assignees

  • 浙江省肿瘤医院

Dates

Publication Date
20260508
Application Date
20260409

Claims (10)

  1. 1. The device for detecting the precision of the radiotherapy bed is characterized by comprising a laser lamp group (4), a test block (1) and a treatment bed board (5), wherein the test block (1) is of a cuboid structure and is provided with at least two measuring surfaces (11), each measuring surface (11) is provided with a scale mark (12) along the vertical and/or horizontal central line and is provided with a through hole (13) at the center, and the measuring surfaces (11) comprise a left measuring surface (11 a), a right measuring surface (11 b) and a front measuring surface (11 c); the laser lamp set (4) comprises a first laser lamp (41), a second laser lamp (42) and a third laser lamp (43) which are fixedly arranged, wherein: -the first laser lamp (41) is for emitting a laser beam towards the left measuring surface (11 a), -the second laser lamp (42) is for emitting a laser beam towards the right measuring surface (11 b), -the third laser lamp (43) is for emitting a laser beam towards the front measuring surface (11 c); And judging whether the position of the test block (1) has deviation or not through the relative relation between the irradiation position of each laser beam on the corresponding measuring surface (11) and the scale mark (12) and the through hole (13).
  2. 2. The apparatus for radiation therapy bed precision detection according to claim 1, wherein the third laser lamp (43) emits a vertical laser beam when the first (41), second (42) laser lamps emit a cross laser beam.
  3. 3. The device for precision detection of radiotherapy beds according to claim 1, characterized in that the radius of the through hole (13) is R, the beam diameters emitted by the laser lamp set (4) are all L1, and the beam diameters L1<2R.
  4. 4. A device for radiation therapy bed precision detection according to claim 3, characterized in that the beam diameter L1> R.
  5. 5. The device for detecting the precision of the radiotherapy bed according to claim 1, further comprising an adjusting device (2), wherein the adjusting device (2) comprises a triangular horizontal plate (21), a first level (21 a) is mounted on the top surface of the triangular horizontal plate (21), the triangular horizontal plate (21) is integrally mounted on a three-dimensional sliding table (22), the triangular horizontal plate (21) comprises a tip portion (21 b), and the tip portion (21 b) is provided with a test block (1).
  6. 6. The apparatus for precision detection of radiotherapy beds according to claim 5, characterized in that the three-dimensional sliding table (22) comprises a first micrometer (221), a second micrometer (222), a third micrometer (223) for adjusting the displacement of the triangular horizontal plate (21) and the test block (1) in horizontal and height directions so that the graduation marks (12) can coincide with the laser beam.
  7. 7. The device for radiation therapy bed precision detection according to claim 1, characterized in that the left measurement surface (11 a) and the right measurement surface (11 b) are divided into four quadrants Q1, Q2, Q3, Q4 by geometric midlines a and b, a group of linear array photosensors (6) is arranged in each quadrant, and the length of the linear array photosensors (6) is consistent with the maximum range of the graduation marks; In the quadrants Q2 and Q4, at least two linear array photoelectric sensors (6) are respectively arranged, and the length direction of each sensor is parallel to a central line a, wherein the minimum distance L2 between the sensor nearest to the central line a and the central line a is larger than R, and the minimum distance between adjacent sensors in the same quadrant is larger than the beam diameter L1 so as to realize redundant detection for resisting vertical beam interference in transverse laser beam measurement; In the quadrants Q1 and Q3, at least two linear array photoelectric sensors (6) are respectively arranged, the length direction of each sensor is parallel to a central line b, wherein the minimum distance L2 between the sensor nearest to the central line b and the central line b is larger than R, and the minimum distance between adjacent sensors in the same quadrant is larger than the beam diameter L1, so that redundant detection of resisting transverse beam interference is realized in vertical laser beam measurement.
  8. 8. The apparatus for radiation therapy couch accuracy detection according to claim 7, wherein the laser light set (4) is a programmable pulse modulated laser light source, the modulation frequency of which is dynamically adjustable based on the ambient light noise spectrum; The device also comprises a synchronous detection processing unit, a built-in digital phase-locked amplifier and a synchronous demodulation unit, wherein the built-in digital phase-locked amplifier is used for synchronously demodulating the laser signals on the measuring surface of the test block (1) under the selected modulation frequency; The system also comprises a processing unit, wherein the processing unit generates a displacement compensation instruction of the treatment bed board (5) in real time according to the demodulation result, and forms a closed loop calibration system.
  9. 9. The apparatus for radiation therapy bed precision detection as claimed in claim 8, wherein, The synchronous detection processing unit executes the following steps: (a) Collecting the spectrum characteristics of ambient light noise when the laser beam is turned off; (b) Selecting a frequency f 0 which is staggered with the noise spectrum peak value from a preset frequency set as a modulation frequency; (c) The laser lamp group (4) is controlled to emit pulse laser at the frequency f 0 , and digital phase-locked demodulation is synchronously started; (d) And driving the treatment bed board (5) to move by a corresponding distance according to the position deviation of the laser output by demodulation.
  10. 10. The apparatus for radiation therapy bed precision detection as claimed in claim 9, wherein, The laser lamps of the laser lamp group (4) emit pulse laser, and each laser lamp adopts a modulation frequency or a coding sequence which are different from each other; The synchronous detection processing unit is internally provided with a plurality of digital lock-in amplifiers or decoding channels, and synchronously demodulates and distinguishes the position signals of the laser beams on the measuring surface (11) by taking the modulation frequency or the code of the corresponding laser lamp as a reference.

Description

Device for detecting precision of radiotherapy bed Technical Field The invention belongs to the technical field of medical appliances, and particularly relates to a device for detecting the precision of a radiotherapy bed Background In radiation therapy, the mechanical precision of the treatment couch (patient support system) is critical. Its mechanical isocenter must be highly coincident with the radiation isocenter produced by the accelerator (linac, proton heavy ion accelerator) to ensure that the radiation beam is able to strike the tumor target accurately while avoiding surrounding normal tissues and critical organs. After long-term use, the position accuracy of the treatment bed may drift due to mechanical abrasion, gravity deformation and the like. Therefore, clinical quality assurance protocols require regular testing of the accuracy of the treatment couch, particularly pre-daily testing (testing). At present, common detection methods are generally complicated, for example, a pointer, a ruler and other tools are used for manual measurement, so that the efficiency is low, the subjectivity is high, and the precision is limited. The detection device is not provided with scales, and the deviation value of the treatment bed cannot be accurately known. There are also some complicated motifs available for accuracy verification, but they are complex to operate, time consuming and difficult to integrate into a strenuous daily clinical workflow. Therefore, there is a strong need in the art for a specific apparatus and method that can accomplish the couch test quickly, easily, and with high accuracy. Disclosure of Invention The invention aims to provide a treatment bed precision detection scheme which is convenient to operate and can realize rapid, visual and even automatic detection and calibration. The device for detecting the precision of the radiotherapy bed comprises a laser lamp set, a test block and a treatment bed board, wherein the test block is of a cuboid structure and is provided with at least two measuring surfaces, each measuring surface is provided with scale marks along the vertical and/or horizontal central line and is provided with a through hole in the center, and the measuring surfaces comprise a left measuring surface, a right measuring surface and a front measuring surface; the laser banks is including fixed first laser lamp, second laser lamp and the third laser lamp that sets up, wherein: The first laser lamp is used for emitting laser beams to the left measuring surface, the second laser lamp is used for emitting laser beams to the right measuring surface, and the third laser lamp is used for emitting laser beams to the front measuring surface; And judging whether the position of the test block has deviation or not according to the relative relation between the irradiation position of each laser beam on the corresponding measurement surface, the scale mark and the through hole. A device for detecting the precision of radiotherapy bed features that the laser lamp set is fixed to the wall of therapeutic room. Wherein, first laser lamp adopts cross laser lamp with the second laser lamp, and the third laser lamp adopts the straight line laser lamp. The laser beams are irradiated onto the measuring surface of the test block, and during initial calibration, all the laser beams are equally divided by the scale marks of the corresponding measuring surface and are in the range of the through holes in the width direction, at the moment, the test block is positioned at a reference position, the condition that the treatment bed has no position deviation is indicated, and the condition is the reference of detection. The device is used for carrying out quick calibration and accuracy verification on the position of the treatment bed before radiation treatment. During detection, the device is arranged on the treatment bed board, and whether the treatment bed board is deviated or not can be judged by observing the irradiation positions of the laser beams on the measurement surface. In actual use, the laser beam may not remain perfectly centered after long periods of operation of the couch, and some degree of deviation may occur. If the laser beam deviates to the outside of the range of the through hole, the deviation value can be directly read through the scale marks on the measuring surface, so that the accuracy state of the treatment bed board can be quantitatively estimated. For the measuring block itself, the number of measuring surfaces can be chosen to be 2,3,4,5. Preferably 3. A device for detecting the precision of radiotherapy bed features that when the first and the second laser lamps emit cross laser beams, the third laser lamp emits vertical laser beams. In a specific measurement example, when the test block deviation is within an acceptable range, all laser beams are kept within the range of the through hole in the width direction. At this time, the first laser lamp emits a cross laser bea