CN116338762A - A radiation dosimeter - Google Patents

Abstract

The application provides a radiation dosimeter, including: a processor, a polarity switching component, and multiple positive pressure output devices and multiple negative pressure output devices. The polarity switching component can switch the polarity of the positive pressure outputter and the negative pressure outputter as the current outputter and the target outputter according to the polarity switching signal of the processor. Turn on the target output device after a set period of time. It can avoid the impact of unstable high voltage on the circuit board of the radiation dosimeter when the polarity is switched, thereby protecting the safety of the radiation dosimeter and the ionization chamber.

Description

A radiation dosimeter

technical field

The present application relates to the technical field of medical devices, in particular to a radiation dosimeter.

Background technique

Radiation dosimeter, an electrometer used for radiation dose-related measurement, is the core instrument for measuring the absolute dose and relative dose of radiation in the field of radiotherapy dosimetry.

When measuring, the radiation dosimeter needs to provide the choice of high voltage polarity for the ionization chamber placed in the radiation environment, and provide positive pressure or negative pressure output for the ionization chamber. Under the action of ray ionization, the cavity of the ionization chamber generates ionized positive and negative charges in the medium. The collector of the ionization chamber represents the amount of positive or negative charges in the medium in the form of current. The radiation dosimeter analyzes the current The deposition energy of the ray in the medium can be obtained, and the absorbed dose in the medium can be calculated. Among them, polarity switching is often required to complete the relevant measurement of the ionization chamber polarity correction factor, that is, to switch between positive voltage and negative voltage. Since the positive voltage of the ionization chamber is usually above 300V (including 300V), and the negative voltage of the ionization chamber is usually less than -300V, the huge voltage difference is likely to cause unstable high-voltage impact on the circuit board of the radiation dosimeter when the polarity is switched. and damage.

Therefore, the present application provides a radiation dosimeter to solve one of the above technical problems.

Contents of the invention

The purpose of this application is to provide a radiation dosimeter that can solve at least one of the above-mentioned technical problems. The specific plan is as follows:

According to the specific implementation mode of the present application, in the first aspect, the present application provides a radiation dosimeter, including: a processor, a polarity switching component, and multiple positive pressure output devices and multiple negative pressure output devices;

The input terminals of the polarity switching component are respectively connected to the first control terminal of the processor for signals, and the multiple output terminals of the polarity switching component are respectively connected to the enabling terminals and the multiple positive pressure output devices. The enabling terminal signal connection of a negative pressure follower is used to use the positive pressure follower and the negative pressure follower as the current exporter and the target exporter in response to receiving the polarity switching signal of the processor. When performing polarity switching, turn on the target output device after turning off the current output device for a preset period of time.

Optionally, the polarity switching component includes: a logic processor, multiple positive voltage drivers and multiple negative voltage drivers;

The driving terminal of the positive pressure driver is signal-connected to the enable terminal of the one-to-one corresponding positive pressure output device, so as to trigger the one-to-one corresponding positive pressure output device to be turned on and off;

The driving terminal of the negative pressure driver is signal-connected to the enable terminal of the one-to-one corresponding negative pressure follower to trigger the one-to-one corresponding negative pressure follower to be turned on and off;

The signal receiving terminal of the logic processor is connected to the first control terminal of the processor, and each signal output terminal of the logic processor is respectively corresponding to the enabling terminal or one-to-one correspondence of the positive voltage driver. The signal connection of the enable end of the negative voltage driver is used to switch the positive voltage driver and the negative voltage driver as the current driver and the target driver according to the polarity switching signal of the processor. Turn on the target driver after a period of time.

Optionally, the logic processor is also configured to switch two positive voltage drivers or two negative voltage drivers as the current driver and the target driver in response to receiving a peer switching signal from the processor , turn on the target driver after turning off the current driver.

Optionally, the radiation dosimeter further includes an interface, and the output ends of the interface are respectively electrically connected to the plurality of positive pressure output devices and the plurality of negative pressure output devices, and are used to output the plurality of positive pressure output devices to the outside. The voltage after the voltage follower and one of the plurality of negative voltage followers are enabled.

Optionally, the radiation dosimeter also includes an acquisition component; the analog signal acquisition end of the acquisition component is connected to the input end of the interface for signal connection, and the digital signal output end of the acquisition component is connected to the receiving end of the processor signal connection, the control terminal of the acquisition component is signal connected with the second control terminal of the processor.

Optionally, the acquisition component includes: a channel switcher, multiple amplifiers and A/D converters;

The control terminal of the channel switcher is connected to the second control terminal signal of the processor, and is used to determine the corresponding amplifier according to the channel switching signal of the processor; the analog signal acquisition terminal of the channel switcher is connected to the The input terminal signal connection of the interface, the analog signal output terminal of the channel switcher is respectively connected with the input terminal signal of the A/D converter, and the digital signal output terminal of the A/D converter is connected with the processor's Receiver signal connection.

Optionally, the plurality of positive voltage followers output different positive voltages; the plurality of negative voltage followers output different negative voltages.

Optionally, the voltage output range of the plurality of positive pressure followers is 0~+1250V, and the voltage output range of the plurality of negative pressure followers is -1250V~0.

Optionally, the plurality of amplifiers at least include a picoampere input bias current operational amplifier and a femtoampere input bias current operational amplifier.

Optionally, the preset time period includes 20ms˜60ms.

Compared with the prior art, the above solution of the embodiment of the present application has at least the following beneficial effects:

The application provides a radiation dosimeter, including: a processor, a polarity switching component, and multiple positive pressure output devices and multiple negative pressure output devices. The polarity switching component can switch the polarity of the positive pressure outputter and the negative pressure outputter as the current outputter and the target outputter according to the polarity switching signal of the processor. Turn on the target output device after a set period of time. It can avoid the impact of unstable high voltage on the circuit board of the radiation dosimeter when the polarity is switched, thereby protecting the safety of the radiation dosimeter and the ionization chamber.

Description of drawings

Fig. 1 shows a schematic structural view of a radiation dosimeter according to an embodiment of the present application;

Fig. 2 shows a schematic structural diagram of a polarity switching assembly according to an embodiment of the present application;

Fig. 3 shows a schematic structural diagram of an acquisition component according to an embodiment of the present application.

Detailed ways

In order to make the purpose, technical solution and advantages of the application clearer, the application will be further described in detail below in conjunction with the accompanying drawings. Apparently, the described embodiments are only some of the embodiments of the application, not all of them. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of this application.

Terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of this application and the appended claims are also intended to include plural forms, unless the context clearly indicates otherwise, "multiple" Generally contain at least two.

It should be understood that the term "and/or" used herein is only an association relationship describing associated objects, which means that there may be three relationships, for example, A and/or B, which may mean that A exists alone, and A and B exist simultaneously. B, there are three situations of B alone. In addition, the character "/" in this article generally indicates that the contextual objects are an "or" relationship.

It should be understood that although terms such as first, second, and third may be used for description in the embodiments of the present application, these descriptions should not be limited to these terms. These terms are used only to differentiate the descriptions. For example, without departing from the scope of the embodiments of the present application, the first may also be referred to as the second, and similarly, the second may also be referred to as the first.

Depending on the context, the words "if", "if" as used herein may be interpreted as "at" or "when" or "in response to determining" or "in response to detecting". Similarly, depending on the context, the phrases "if determined" or "if detected (the stated condition or event)" could be interpreted as "when determined" or "in response to the determination" or "when detected (the stated condition or event) )" or "in response to detection of (a stated condition or event)".

It should also be noted that the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that an article or arrangement comprising a list of elements includes not only those elements but also includes items not expressly listed. other elements of the product, or elements inherent in the product or device. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in an article or device comprising said element.

In particular, it should be noted that if the symbols and/or numbers in the description are not marked in the description of the drawings, they are not reference signs.

Optional embodiments of the present application will be described in detail below in conjunction with the accompanying drawings.

The embodiment provided in this application is an embodiment of a radiation dosimeter.

Embodiments of the present application will be described in detail below in conjunction with the accompanying drawings.

The application provides a radiation dosimeter, including: a processor, a polarity switching component, and multiple positive pressure output devices and multiple negative pressure output devices.

The processor is the core component of the radiation dosimeter, the calculation and control core of the radiation dosimeter, and the final executor of information processing and program operation. For example, the processor includes a central processing unit (English full name central processing unit, referred to as CPU), which uses a 90-nanometer fixed memory, also known as a non-volatile memory (English full name Adaptive Real-Time Memory Accelerator, referred to as NVM) and an adaptive real-time memory accelerator ( The English full name is AdaptiveReal-Time Memory Accelerator, referred to as ART); ART technology enables zero-wait execution of the program, improves the efficiency of program execution, and maximizes the performance of the CPU, reaching 210DMIPS@168MHz performance; ART can completely release the performance of the CPU core ; When the CPU works at the allowed frequency (≤168MHz), the program running in the flash memory can achieve the performance equivalent to zero waiting cycles; it integrates single-cycle DSP instructions and floating point units (English full name floating pointunit, referred to as FPU) can realize functions such as filtering and communication.

The positive voltage output device is used for outputting positive voltage, for example, a positive voltage power supply.

The negative voltage output device is used for outputting negative voltage, for example, a negative voltage power supply.

When the enable terminal of the positive voltage output device obtains the permission signal, the positive voltage output device can output positive voltage to the outside, that is, the positive voltage output device is turned on; when the enable terminal of the positive voltage output device obtains the prohibition signal, the positive voltage output device The device stops outputting positive voltage to the outside, that is, the positive voltage output device is turned off.

When the enable terminal of the negative voltage output device obtains a permission signal, the negative voltage output device can output negative voltage to the outside, that is, the negative voltage output device is turned on; when the enable terminal of the negative voltage output device obtains a prohibition signal, the negative voltage output device The device stops outputting negative voltage to the outside, that is, the negative voltage output device is turned off.

The embodiments of the present disclosure provide multiple positive pressure output devices and multiple negative pressure output devices. Users can flexibly use a combination of positive pressure output devices and negative pressure output devices to switch polarity according to the needs of application scenarios, and obtain The required data collection greatly improves the user experience.

In some specific embodiments, the plurality of positive voltage followers output different positive voltages to the outside; the plurality of negative voltage followers output different negative voltages to the outside. For example, 5 positive pressure output devices output +500v, +400v, +300v, +200v, +100v respectively; 5 negative pressure output devices output -500v, -400v, -300v, -200v, -100v respectively. In this application, the output voltage of the radiation dosimeter is changed by switching between multiple positive pressure output devices and multiple negative pressure output devices.

In some other specific embodiments, the voltage output range of the plurality of positive pressure followers is 0-+1250V, and the voltage output range of the plurality of negative-voltage followers is -1250V～0.

The input terminals of the polarity switching component are respectively connected to the first control terminal of the processor for signals, and the multiple output terminals of the polarity switching component are respectively connected to the enabling terminals and the multiple positive pressure output devices. The enabling terminal signal connection of a negative pressure follower is used to use the positive pressure follower and the negative pressure follower as the current exporter and the target exporter in response to receiving the polarity switching signal of the processor. When performing polarity switching, turn on the target output device after turning off the current output device for a preset period of time.

For example, as shown in Figure 1, the first control terminal of the processor is signal-connected to the input terminal of the polarity switching component, and the polarity switching component has 4 output terminals, and each output terminal is respectively connected to the first positive The enable end of the pressure follower, the enable end of the second positive pressure follower, the enable end of the first negative pressure follower, and the enable end of the second negative pressure follower are signal connected.

Optionally, the preset time period includes 20ms˜60ms. According to the experiment, when the polarity is switched, switch from +1250V to -1250V, or from -1250V to +1250V, the preset time period is set to 60ms, which can not only ensure the safety of the circuit board of the radiation dosimeter, but also ensure the safety of the polarity. The efficiency of switching; and under the minimum extreme difference (that is, the absolute value of the positive voltage output by the positive pressure output device and the negative voltage voltage of the negative pressure output device), when the preset time period is at least 20ms, the radiation dosimeter can be guaranteed The relative safety of the circuit board. When the current output device of the radiation dosimeter output voltage is a positive pressure output device, and the target output device to be switched is a negative pressure output device, the polarity switching component obtains the first switching from the positive pressure output device to the negative pressure output device. After the polarity switching signal, first turn off the positive pressure output device for a preset period of time, and then turn on the negative pressure output device. When the current output device of the output voltage of the radiation dosimeter is a negative pressure output device, and the target output device to be switched is a positive pressure output device, the polarity switching component obtains the second switching from the negative pressure output device to the positive pressure output device. After the polarity switching signal, first turn off the negative pressure output device for a preset period of time, and then turn on the positive pressure output device. In this way, the impact of unstable high voltage on the circuit board of the radiation dosimeter can be avoided when the polarity is switched, thereby protecting the safety of the radiation dosimeter and the ionization chamber.

In some specific embodiments, the polarity switching component includes: a logic processor and a plurality of positive voltage drivers and a plurality of negative voltage drivers.

The logic processor includes a Field Programmable Gate Array (Field Programmable Gate Array, FPGA for short).

The basic structure of FPGA includes: programmable input and output units, configurable logic blocks, digital clock management modules, embedded block RAM, wiring resources, embedded dedicated hard cores, and embedded functional units at the bottom. FPGA uses a small look-up table (16×1RAM) to implement combinatorial logic, each look-up table is connected to the input of a D flip-flop, and the flip-flop drives other logic circuits or drives I/O, thus forming a combinatorial The logic function can also realize the basic logic unit module of the sequential logic function, and these modules are connected to each other or to the I/O module by metal wires. The logic of the FPGA is realized by loading programming data to the internal static storage unit. The value stored in the memory unit determines the logic function of the logic unit and the connection mode between modules or between modules and I/O, and finally determines the The functions that FPGA can realize. In this specific embodiment, the digital clock management module is used to manage the preset time period. Optionally, for polarity switching of different extremes, a corresponding preset time period is adopted. For example, switch from +1250V to -1250V, or switch from -1250V to +1250V, the preset time period is 60ms; switch from +400V to -300V, the preset time period is 30ms; the preset time period under the minimum range is 20ms.

The driving terminals of the positive voltage drivers are signal-connected to the enable terminals of the one-to-one corresponding positive-voltage output devices, so as to trigger the one-to-one corresponding positive-voltage output devices to be turned on and off.

It can be understood that the driving end of each positive voltage driver in the polarity switching assembly is signal-connected to the enabling end of a one-to-one corresponding positive voltage output device outside the polarity switching assembly. The enabling signal or prohibiting signal obtained by the enabling terminal of each positive-voltage follower comes from the driving terminal of the positive-voltage driver corresponding to the positive-voltage follower one by one. The positive voltage driver can be a miniature relay, but this embodiment is not limited thereto.

The driving terminals of the negative pressure drivers are signal-connected to the enable terminals of the one-to-one corresponding negative pressure followers, so as to trigger the one-to-one corresponding negative pressure followers to be turned on and off.

It can be understood that the driving end of each negative pressure driver in the polarity switching assembly is signal-connected to the enabling end of a one-to-one corresponding negative voltage output device outside the polarity switching assembly. The enabling signal or prohibiting signal obtained by the enabling terminal of each negative pressure follower comes from the driving terminal of the negative voltage driver corresponding to the negative pressure follower one by one. The negative pressure driver may be a miniature relay, but this embodiment is not limited thereto.

The signal receiving terminal of the logic processor is connected to the first control terminal of the processor, and each signal output terminal of the logic processor is respectively corresponding to the enabling terminal or one-to-one correspondence of the positive voltage driver. The signal connection of the enable end of the negative voltage driver is used to switch the positive voltage driver and the negative voltage driver as the current driver and the target driver according to the polarity switching signal of the processor. Turn on the target driver after a period of time.

For example, as shown in Figure 2, the first control terminal of the processor is signal-connected to the signal receiving terminal of the logic processor, the logic processor has 4 signal output terminals, each signal of the logic processor The output terminals are respectively connected to the enable terminal of the first positive pressure driver, the enable terminal of the second positive pressure driver, the enable terminal of the first negative pressure driver, and the enable terminal of the second negative pressure driver; The driving terminal of the pressure driver is connected to the enabling terminal of the first positive pressure output device outside the polarity switching component, and the driving terminal of the second positive pressure driver is connected to the enabling terminal of the second positive pressure output device outside the polarity switching component. Signal connection, the driving end of the first negative pressure driver is connected to the enabling end of the first negative pressure output device outside the polarity switching component, the driving end of the second negative pressure driver is connected to the second negative pressure outside the polarity switching component The signal connection of the enable terminal of the output device.

In some specific embodiments, the logic processor is further configured to use two positive voltage drivers or two negative voltage drivers as the current driver and the target in response to receiving a peer switching signal from the processor. When the driver switches, the target driver is turned on after the current driver is turned off.

In this specific embodiment, when switching between two positive voltages or between two negative voltages, it is not necessary to turn off the current driver for a preset time period and then turn on the target driver, but to switch directly. On the basis of circuit safety of the dosimeter, time delay is avoided and measurement efficiency is improved.

In some specific embodiments, the radiation dosimeter further includes an interface, and the output ends of the interface are respectively electrically connected to the plurality of positive pressure output devices and the plurality of negative pressure output devices, for outputting the A voltage after enabling one of the plurality of positive voltage followers and the plurality of negative voltage followers.

The interface includes a TNC interface. Two cables are connected to the TNC interface, one cable is connected to the cavity of the ionization chamber, and the other cable is connected to the collector of the ionization chamber.

In this specific embodiment, the voltage is uniformly output to the power room outside the radiation dosimeter through the interface. For example, as shown in FIG. 1 , the first positive pressure output device, the second positive pressure output device, the first negative pressure output device and the second negative pressure output device are all electrically connected to the output ends of the interface.

In some specific embodiments, as shown in FIG. 1 , the radiation dosimeter further includes a collection component. The analog signal acquisition terminal of the acquisition component is connected to the input terminal of the interface, the digital signal output terminal of the acquisition component is connected to the receiving end of the processor, and the control terminal of the acquisition component is connected to the processing terminal. The second control terminal signal connection of the device.

The acquisition component of this specific embodiment receives the measurement signal of the ionization chamber through the input end of the interface, and then sends the measurement signal to the processor by converting the measurement signal from an analog signal into a digital signal.

In some specific embodiments, the acquisition component includes: a channel switcher, multiple amplifiers and an A/D converter.

Channel switcher, including FPGA.

The control terminal of the channel switcher is signal-connected to the second control terminal of the processor for determining the corresponding amplifier according to the channel switching signal of the processor. The analog signal acquisition terminal of the channel switcher is connected to the input terminal signal of the interface, the analog signal output terminal of the channel switcher is respectively connected to the input terminal signal of the A/D converter, and the A/D The digital signal output end of the converter is signally connected with the receiving end of the processor.

Before each measurement, according to the use of the ionization chamber, the processor can send a channel switching signal to the channel switcher in advance, so as to determine the amplifier used for the measurement. For example, as shown in Figure 3, the radiation dosimeter has four independent gain channels: the first amplifier, the second amplifier, the third amplifier and the fourth amplifier; the channel switching signal sent by the processor to the channel switcher specifies the first 2. The amplifier amplifies the collected measurement signal.

This specific embodiment provides independent gain channels for the measurement of different scenarios, effectively reduces the noise generated by the amplifier, reduces the interference between different components, is beneficial to improve the signal-to-noise ratio of the circuit, and ensures the quality of the collected data.

In some embodiments, the plurality of amplifiers includes at least a picoampere (nA) input bias current operational amplifier and a femtoampere (fA) input bias current operational amplifier. The femtoampere (fA) input bias current operational amplifier can process ultra-low input bias current, which ensures that the radiation dosimeter can measure weak current signals, and effectively collect and store weak current signals, which improves the signal of the circuit. noise ratio.

Finally, it should be noted that each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other.

The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still apply to the foregoing embodiments Modifications are made to the recorded technical solutions, or equivalent replacements are made to some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims (10)

1. A radiation dosimeter, characterized in that, comprising: a processor, a polarity switching assembly, and a plurality of positive pressure output devices and a plurality of negative pressure output devices; The input terminals of the polarity switching component are respectively connected to the first control terminal of the processor for signals, and the multiple output terminals of the polarity switching component are respectively connected to the enabling terminals and the multiple positive pressure output devices. The enabling terminal signal connection of a negative pressure follower is used to use the positive pressure follower and the negative pressure follower as the current exporter and the target exporter in response to receiving the polarity switching signal of the processor. When performing polarity switching, turn on the target output device after turning off the current output device for a preset period of time. 2. The radiation dosimeter according to claim 1, wherein the polarity switching component comprises: a logic processor, a plurality of positive pressure drivers and a plurality of negative pressure drivers; The driving terminal of the positive pressure driver is signal-connected to the enable terminal of the one-to-one corresponding positive pressure output device, so as to trigger the one-to-one corresponding positive pressure output device to be turned on and off; The driving terminal of the negative pressure driver is signal-connected to the enable terminal of the one-to-one corresponding negative pressure follower to trigger the one-to-one corresponding negative pressure follower to be turned on and off; The signal receiving terminal of the logic processor is connected to the first control terminal of the processor, and each signal output terminal of the logic processor is respectively corresponding to the enabling terminal or one-to-one correspondence of the positive voltage driver. The signal connection of the enable end of the negative voltage driver is used to switch the positive voltage driver and the negative voltage driver as the current driver and the target driver according to the polarity switching signal of the processor. Turn on the target driver after a period of time. 3. The radiation dosimeter according to claim 2, wherein the logic processor is also used to switch two positive pressure drivers or two negative pressure drivers in response to receiving the same-level switching signal of the processor When the driver switches between the current driver and the target driver, the target driver is turned on after the current driver is turned off. 4. The radiation dosimeter according to claim 1, characterized in that, the radiation dosimeter further comprises an interface, and the output ends of the interface are respectively connected to the plurality of positive pressure output devices and the plurality of negative pressure output devices. The device is electrically connected, and is used for externally outputting the enabled voltage of one of the plurality of positive voltage output devices and the plurality of negative voltage output devices. 5. The radiation dosimeter according to claim 4, characterized in that, the radiation dosimeter also includes an acquisition component; the analog signal acquisition end of the acquisition component is connected to the input terminal signal of the interface, and the acquisition component The digital signal output end of the digital signal is connected to the receiving end of the processor, and the control end of the acquisition component is connected to the second control end of the processor. 6. The radiation dosimeter according to claim 5, wherein the acquisition component comprises: a channel switcher, a plurality of amplifiers and an A/D converter; The control terminal of the channel switcher is connected to the second control terminal signal of the processor, and is used to determine the corresponding amplifier according to the channel switching signal of the processor; the analog signal acquisition terminal of the channel switcher is connected to the The input terminal signal connection of the interface, the analog signal output terminal of the channel switcher is respectively connected with the input terminal signal of the A/D converter, and the digital signal output terminal of the A/D converter is connected with the processor's Receiver signal connection. 7 . The radiation dosimeter according to claim 1 , wherein the plurality of positive pressure output devices output different positive voltages; the plurality of negative pressure output devices output different negative voltages. 8. The radiation dosimeter according to claim 7, wherein the voltage output range of the plurality of positive pressure followers is 0 to +1250V, and the voltage output range of the plurality of negative pressure followers is -1250V ~0. 9. The radiation dosimeter according to claim 6, wherein the plurality of amplifiers at least comprise a picoampere input bias current operational amplifier and a femtoampere input bias current operational amplifier. 10. The radiation dosimeter according to claim 8, wherein the preset time period includes 20ms˜60ms.

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