Applicator dose rate meter based on current-frequency conversion

Abstract

The invention relates to an applicator dose rate meter based on current-frequency conversion, which belongs to the field of nuclear radiation monitoring and comprises an ionization chamber, a current-frequency conversion module, a signal acquisition module, a data processing module, a display module and a power supply module. When ionizing radiation enters, the ionization chamber generates electron-ion pairs, and then current signals are generated under the action of an electric field. The current-frequency conversion module converts the received current signal into a voltage signal and converts the voltage signal into a frequency signal; the signal acquisition module acquires and transmits a frequency signal; the data processing module calculates the radiation dose of the applicator in real time according to the received frequency signal in combination with a frequency-dose conversion coefficient obtained by scales in a standard radiation field; the display module displays the radiation dose data; the power module supplies power to the device. By adopting the device disclosed by the invention, the radiation dose of the applicator can be monitored in real time, the safety of a patient is guaranteed, and the device has important application value.

Description

Technical Field

[0001] The invention belongs to the field of nuclear radiation monitoring, and in particular relates to an applicator dose rate meter based on current-frequency conversion. Background Art

[0002] Radionuclide patch therapy is an important method of nuclear medicine. It refers to a contact radiation therapy method that selects an appropriate radionuclide surface source as an applicator to cover the surface of the patient's lesion and irradiate for a certain period of time to achieve the purpose of treatment. Radionuclide patch therapy has the characteristics of thorough treatment, no scars, simple method, economical, painless, and no itching. Therefore, it is widely popular in clinical practice. For example, the commonly used 90 Sr applicator is used for the treatment of hemangioma, neurodermatitis, chronic eczema, scars, etc.

[0003] In the process of using beta applicators to treat skin lesions, in order to ensure the effect of radiotherapy and prevent patients from getting skin burns, it is necessary to accurately measure the (tissue) absorbed dose rate on the surface of the beta applicator and correctly estimate the skin dose received by the patient, so as to formulate a reasonable and safe treatment plan. The GBZ134-2002 Standard for Health Protection of Radionuclide Patching Therapy stipulates that it is necessary to regularly test the air absorbed dose rate (or reference point air absorbed dose rate) and surface uniformity of the applicator surface to adjust the irradiation dose and protect the health and safety of professionals, patients and the public.

[0004] At present, during the use of the applicator, the theoretical value of the dose rate is usually calculated based on the parameters of the applicator when it leaves the factory, and the radiation dose of the applicator is not monitored in time, which results in low accuracy of the radiation dose data of the applicator, posing a threat to patient safety. Summary of the invention

[0005] In view of the defects existing in the prior art, the purpose of the present invention is to provide an applicator dose rate meter based on current-frequency conversion, which can monitor the radiation dose of the applicator in real time and ensure the safety of the patient, and has important application value.

[0006] To achieve the above object, the technical solution adopted by the present invention is: an applicator dose rate meter based on current-frequency conversion, the device comprising an ionization chamber, a current-frequency conversion module, a signal acquisition module, a data processing module, a display module and a power supply module;

[0007] The ionization chamber is used to generate electron-ion pairs when ionizing radiation enters, and then generate current signals under the action of the electric field;

[0008] The current-frequency conversion module is used to convert the received current signal into a voltage signal, and convert the voltage signal into a frequency signal;

[0009] The signal acquisition module is used to collect frequency signals and transmit them to the data processing module;

[0010] The data processing module is used to process and analyze the received frequency signal, and calculate the actual radiation dose of the applicator according to the frequency-dose conversion coefficient obtained by calibration in the standard radiation field;

[0011] The display module is used to display radiation dose data in real time;

[0012] The power module is used to supply power to the device.

[0013] Furthermore, the data processing module controls the power supply module to perform polarity conversion on the voltage electrode of the ionization chamber.

[0014] Furthermore, the ionization chamber includes two parallel electrodes, wherein the first electrode is connected to high voltage and the second electrode is grounded, and the first electrode switches to a negative voltage after working at a positive voltage for a preset time.

[0015] Furthermore, the current-frequency conversion module converts the current signal into a sawtooth voltage signal by charging the capacitor.

[0016] Furthermore, the current-frequency conversion module converts the voltage signal into a frequency signal after passing through an amplitude discriminator and a monostable trigger.

[0017] Furthermore, the signal acquisition module includes an input capture module of a microprocessor.

[0018] Furthermore, the data processing module is also used to determine whether the actual radiation dose of the applicator exceeds the safe dose according to a preset threshold or preset conditions, and trigger an alarm or prompt message when the judgment result is that the safe dose is exceeded.

[0019] Furthermore, the data processing module includes a microprocessor and a memory.

[0020] Furthermore, the power supply voltage range of the current-frequency conversion module, the signal acquisition module, the data processing module and the display module is between 5V and 12V.

[0021] Furthermore, the power supply voltage of the data processing module is 5V or 3.3V.

[0022] The beneficial technical effect of the present invention is that when ionizing radiation enters the ionization chamber, electron-ion pairs are generated in the chamber, and these electron-ion pairs are collected under the action of the electric field to generate current signals. There is a certain conversion relationship between the generated current signal and the ionizing radiation dose. By applying the current-frequency conversion technology to the applicator radiation monitor, real-time monitoring of the radiation dose of the applicator is achieved, providing a reliable basis for doctors to set reasonable and accurate treatment plans, avoiding unnecessary damage to patients due to insufficient irradiation doses that cannot achieve therapeutic effects or excessive irradiation doses, ensuring the health and safety of practitioners, patients and work, and having broad application prospects and market prospects in the medical field. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the structure of an applicator dose rate meter based on current-frequency conversion according to the first embodiment of the present invention. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0025] Embodiment 1

[0026] like Figure 1 As shown, an embodiment of the present invention provides an applicator dose rate meter based on current-frequency conversion, including an ionization chamber, a current-frequency conversion module, a signal acquisition module, a data processing module, a display module and a power module.

[0027] The ionization chamber consists of two parallel electrodes, one of which is connected to a high voltage and the other to ground. When ionizing radiation (such as beta rays) enters the ionization chamber, electron-ion pairs are generated in the chamber. These electron-ion pairs are collected under the action of an electric field and generate a current signal.

[0028] The current-frequency conversion module is used to convert the current signal into a sawtooth voltage signal through capacitor charging, and then convert the voltage signal into a frequency signal after passing through an amplitude discriminator and a monostable trigger. The larger the current signal, the faster the sawtooth voltage signal increases, and the higher the frequency of the output frequency signal.

[0029] The signal acquisition module is used to collect the frequency signal and transmit it to the data processing module. Signal acquisition is usually completed by the input capture module of the microprocessor.

[0030] The data processing module is the control center of the applicator dose rate meter, which is used to process and analyze the received frequency signal, and calculate the actual radiation dose of the applicator based on the frequency-dose conversion coefficient obtained by calibrating in the standard radiation field. The data processing module includes components such as a microprocessor and a memory, which can realize high-speed data processing and storage. At the same time, it can determine whether the safe dose is exceeded based on preset thresholds or preset conditions, and trigger corresponding alarms or prompt messages.

[0031] The display module is used to display the calculated radiation dose to the user in real time. The power module is used to provide power to each module. Usually, the voltage required by the current-frequency conversion module, signal acquisition module, data processing module and display module is a low voltage between 5-12V. The specific voltage can be determined according to the module design. For example, the power supply of most microprocessors is 5V or 3.3V.

[0032] Ionization chamber is a type of gas detector. It works in the ionization chamber area, also called the saturation area, that is, the collection voltage can achieve complete collection of ion pairs generated by radiation particles in the working gas, and the recombination loss is low enough. Different ionization chambers have different collection voltage working ranges, which need to be determined experimentally.

[0033] In addition, the voltage supplied to the ionization chamber needs to convert the polarity of the electrode. This is because when the beta particles hit the electrode, they will generate current and thus affect the accuracy of the results. It is necessary to eliminate the above influence through positive and negative electrode conversion combined with subsequent data processing.

[0034] The parallel plates of an ionization chamber are circular with a diameter of 60 mm, and the distance between the two parallel plates is 3 mm. After testing, when the collector voltage is connected to +20V, the ionization chamber works in the ionization zone, and the other end of the electrode is grounded. After the collector works at a voltage of +20V for a period of time, it is switched to -20V to eliminate the influence of the current generated by β particles hitting the electrode on the accuracy of the measurement result.

[0035] When ionizing radiation (such as beta rays) enters the ionization chamber, electron-ion pairs are generated in the ionization chamber. These electron-ion pairs are collected under the action of the electric field and generate current signals. The current signal is first converted into a sawtooth voltage signal through capacitor charging by the current-frequency conversion module, and then the voltage signal is converted into a frequency signal through the amplitude discriminator and the monostable trigger. The larger the current signal, the faster the sawtooth voltage signal increases, and the higher the frequency of the output frequency signal. The signal acquisition module, such as the input capture module of the microprocessor, collects the output frequency signal and transmits it to the data processing module. The data processing module is the control center of the applicator dose rate meter. It can be designed as a programmable device such as a microprocessor or FPGA. It is responsible for processing and analyzing the collected data. According to the frequency-dose conversion coefficient obtained by calibrating in the standard radiation field, the data is converted into the actual radiation dose value of the applicator. At the same time, the module can realize high-speed data processing and storage, and can judge whether the safe dose is exceeded according to the preset threshold or condition, and trigger the corresponding alarm or prompt information. The radiation dose value, alarm or prompt information, threshold information, etc. calculated by the data processing module can be displayed in real time on the display module.

[0036] It can be seen from the above embodiments that the dose rate meter for an applicator based on current-frequency conversion disclosed by the present invention, when ionizing radiation enters, the ionization chamber generates electron-ion pairs, and then generates current signals under the action of the electric field; the current-frequency conversion module converts the received current signal into a voltage signal; the signal acquisition module acquires the frequency signal and transmits it to the data processing module; the data processing module processes and analyzes the received frequency signal, and calculates the radiation dose of the applicator in real time according to the frequency-dose conversion coefficient obtained by the scale; the display module displays the radiation dose data; and the power module supplies power to the device. The device disclosed in this application can monitor the radiation dose value of the applicator in real time, provide protection for the patient's medication safety, and has important application value.

[0037] The device described in the present invention is not limited to the embodiments described in the specific implementation manner. Those skilled in the art may derive other implementation manners based on the technical solution of the present invention, which also fall within the technical innovation scope of the present invention.

Claims

1. An applicator dose rate meter based on current-frequency conversion, characterized in that: The device includes an ionization chamber, a current-frequency conversion module, a signal acquisition module, a data processing module, a display module and a power supply module; The ionization chamber is used to generate electron-ion pairs when ionizing radiation enters, and then generate current signals under the action of the electric field; The current-frequency conversion module is used to convert the received current signal into a voltage signal, and convert the voltage signal into a frequency signal; The signal acquisition module is used to collect frequency signals and transmit them to the data processing module; The data processing module is used to process and analyze the received frequency signal, and calculate the actual radiation dose of the applicator according to the frequency-dose conversion coefficient obtained by calibration in the standard radiation field; The display module is used to display radiation dose data in real time; The power module is used to supply power to the device.

2. The dose rate meter for an applicator based on current-frequency conversion as claimed in claim 1, characterized in that: The data processing module controls the power supply module to perform polarity conversion on the voltage electrode of the ionization chamber.

3. The dose rate meter for an applicator based on current-frequency conversion as claimed in claim 2, characterized in that: The ionization chamber comprises two parallel electrodes, wherein the first electrode is connected to high voltage and the second electrode is grounded, and the first electrode switches to a negative voltage after working at a positive voltage for a preset time.

4. The dose rate meter for an applicator based on current-frequency conversion as claimed in claim 1, characterized in that: The current-frequency conversion module converts the current signal into a sawtooth voltage signal by charging the capacitor.

5. The dose rate meter for an applicator based on current-frequency conversion as claimed in claim 1, characterized in that: The current-frequency conversion module converts the voltage signal into a frequency signal after passing through an amplitude discriminator and a monostable trigger.

6. The dose rate meter for an applicator based on current-frequency conversion as claimed in claim 1, characterized in that: The signal acquisition module includes an input capture module of a microprocessor.

7. The dose rate meter for an applicator based on current-frequency conversion as claimed in claim 1, characterized in that: The data processing module is also used to determine whether the actual radiation dose of the applicator exceeds the safe dose according to a preset threshold or preset conditions, and trigger an alarm or prompt information when the judgment result is that the safe dose is exceeded.

8. The dose rate meter for an applicator based on current-frequency conversion as claimed in claim 1, characterized in that: The data processing module includes a microprocessor and a memory.

9. The dose rate meter for an applicator based on current-frequency conversion as claimed in claim 1, characterized in that: The power supply voltage range of the current-frequency conversion module, the signal acquisition module, the data processing module and the display module is between 5V and 12V.

10. The dose rate meter for an applicator based on current-frequency conversion as claimed in claim 9, characterized in that: The power supply voltage of the data processing module is 5V or 3.3V.

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