Scintillation pulse digitization method, detector and computer readable storage medium

Abstract

This application proposes a scintillation pulse digitization method, detector, and computer-readable storage medium. The digitization method includes: acquiring multiple scintillation pulse signals with different decay times; summing the multiple scintillation pulse signals and outputting the summed scintillation pulse signal; and sampling the summed scintillation pulse signal to obtain a digital signal. The detector includes a processing circuit and a sampling circuit. The processing circuit sums the multiple scintillation pulse signals with different decay times and outputs the summed scintillation pulse signal; and the sampling circuit samples the summed scintillation pulse signal to obtain a digital signal. This application achieves high multiplexing efficiency during the scintillation pulse digitization process, effectively reducing subsequent processing and acquisition channels.

Description

Technical Field

[0001] The present application relates to the field of signal acquisition, and in particular to a scintillation pulse digitization method, a detector, and a computer-readable storage medium. Background Art

[0002] As a semiconductor optoelectronic device, SiPM is widely used in a variety of photoelectric conversion detectors and related applications due to its compact structure, fast response speed, and high gain. For example, it is used in PET detectors, CT detectors, and nuclear radiation detectors. In PET instruments, the scintillating crystals and SiPMs in the SiPM-designed detectors are usually coupled one-to-one (some systems that pursue high spatial resolution will use crystals smaller than the SiPM for coupling). The pulse signal output by the SiPM is processed and collected by the circuit system, which can further detect the energy, time, and position of the incident high-energy particles. In practical applications, the number of channels of the circuit system matched with the detector is often very large. In order to reduce the number of channels and complexity of the subsequent circuit system, corresponding methods and circuits are usually designed to achieve the multiplexing of the pulse signal channels output by multiple SiPMs.

[0003] When designing detectors using SiPM, the mainstream methods for multiplexing SiPM output signals to reduce the number of readout channels are mainly the center of gravity weighting method and the strip-line method.

[0004] The core idea of the center-of-gravity weighting method is to convert the pulse signal output by each SiPM in an M×N detector array into four pulses using a specific proportional coefficient, based on the position of each SiPM. The four pulses corresponding to each SiPM are then summed and output. Therefore, based on the proportional relationship between these four pulses, the corresponding SiPM position, number, and original signal can be inferred. The output signals of the detector using M×N SiPMs are multiplexed, ultimately outputting four angular signals. The center-of-gravity weighting method is often implemented using a resistor-weighted network or a capacitor-weighted network.

[0005] The core idea of the strip-line method is to split the SiPM output signal into two paths. Depending on the location of each SiPM, the transmission paths corresponding to the two signals are set to different lengths. The two pulses corresponding to each SiPM are then summed and output. Therefore, based on the mismatch in the arrival times of the two summed pulses, the corresponding SiPM position, number, and original signal can be inferred. The output signals of a detector using M SiPMs are multiplexed, ultimately outputting two pulse signals. The strip-line multiplexing method is achieved by connecting multiple SiPMs to different locations on a strip transmission line.

[0006] When a small number of SiPM channels are multiplexed, the multiplexing efficiency of the centroid-weighted and strip-line methods is low. Taking the multiplexing of the output signals of 2×2 SiPMs as an example, the ratio of the original channel number to the multiplexed channel number is 4:4 when using the centroid-weighted method, while the ratio of the original channel number to the multiplexed channel number is 4:2 when using the strip-line method. Furthermore, when using the strip-line method for multiplexing, the SiPMs and scintillation crystals in the detector must be coupled one-to-one. Therefore, the size of the SiPM determines the spatial resolution of the PET detector, and it is impossible to improve spatial resolution by coupling the SiPMs with smaller crystals. Furthermore, due to the inherent dark noise and junction capacitance of SiPMs, as the number of multiplexed channels increases, the noise of the multiplexed signal output channels will increase due to the increase in the number of SiPMs, ultimately affecting system performance. Summary of the Invention

[0007] The present application provides a scintillation pulse digitization method, a detector, and a computer-readable storage medium, which solve at least one of the above problems.

[0008] According to one aspect of the present application, a method for digitizing a scintillation pulse is provided, the method comprising the following steps:

[0009] Step S1: Acquire multiple scintillation pulse signals with different decay times;

[0010] Step S2: adding the plurality of scintillation pulse signals and outputting the added scintillation pulse signal; and

[0011] Step S3: sampling the summed scintillation pulse signal to obtain a digital signal.

[0012] According to some embodiments, the scintillation pulse signal is obtained by converting visible light through a silicon photomultiplier tube, and the silicon photomultiplier tube and the scintillation crystal are coupled in a one-to-one manner or a many-to-many manner.

[0013] According to some embodiments, the effective cross-sectional dimensions of the scintillator crystal and the silicon photomultiplier tube are set to be the same.

[0014] According to some embodiments, the effective cross-sectional size of the scintillator crystal is set to be smaller than the effective cross-sectional size of the silicon photomultiplier tube.

[0015] According to some embodiments, the ratio of the number of the scintillation crystals to the number of the silicon photomultiplier tubes is set to 3:2 or a multiple of 3:2, and the scintillation crystals and the silicon photomultiplier tubes are set to be coupled at a ratio of 3:2 or a multiple of 3:2.

[0016] According to some embodiments, in step S1 , a plurality of scintillation pulse signals with different decay times are acquired using a plurality of scintillation crystals with different decay time constants and / or a plurality of silicon photomultiplier tubes with different recovery times.

[0017] According to some embodiments, in step S1 , a signal adjustment circuit is used to obtain a plurality of scintillation pulse signals with different decay times.

[0018] According to some embodiments, the signal conditioning circuit includes a passive RC circuit, a passive LC circuit, an active circuit, or an analog signal filter.

[0019] According to some embodiments, before step S1 , scintillation pulse signals with different decay times are obtained by setting parameters of a signal adjustment circuit in the detector.

[0020] According to some embodiments, in step S2 , the plurality of scintillation pulse signals with different decay times are grouped, and then the scintillation pulse signals in each group are summed to output a plurality of summed scintillation pulse signals.

[0021] According to some embodiments, in step S3 , sampling the summed scintillation pulse signal includes sampling the summed scintillation pulse signal through an analog-to-digital conversion circuit, wherein the analog-to-digital conversion circuit includes an ADC sampling circuit and an MVT sampling circuit.

[0022] According to some embodiments, the digitization method further comprises step S4: analyzing the digital signal, calculating the decay time corresponding to the scintillation pulse signal, and determining the position of the corresponding scintillation crystal.

[0023] According to one aspect of the present application, a method for digitizing a scintillation pulse is provided, the method comprising the following steps:

[0024] Step S0': setting a many-to-many coupling mode between the scintillation crystal and the silicon photomultiplier tube, wherein the effective cross-sectional area of the scintillation crystal is smaller than the effective cross-sectional area of the silicon photomultiplier tube;

[0025] Step S1 ′: acquiring a plurality of scintillation pulse signals with different decay times from the silicon photomultiplier tube;

[0026] Step S2': adding up the plurality of scintillation pulse signals and outputting the added scintillation pulse signal; and

[0027] Step S3 ′: sampling the summed scintillation pulse signal to obtain a digital signal.

[0028] According to some embodiments, the method further comprises step S4 ′: analyzing the obtained digital signal, calculating the decay time corresponding to the scintillation pulse signal, and determining the corresponding position of the scintillation crystal.

[0029] According to one aspect of the present application, a detector is proposed, which includes multiple scintillation crystals and multiple silicon photomultiplier tubes, the scintillation crystals are used to receive incident particles and generate visible light signals in response to the incident particles; the silicon photomultiplier tubes are respectively coupled to the multiple scintillation crystals and generate scintillation pulse signals in response to the visible light signals generated by the multiple scintillation crystals; it is characterized in that the detector also includes: a processing circuit, which adds the multiple scintillation pulse signals and outputs the added scintillation pulse signal, wherein the scintillation pulse signals have different decay times; and a sampling circuit, which samples the added scintillation pulse signal to obtain a digital signal.

[0030] According to some embodiments, the processing circuit includes a plurality of signal adjustment circuits, each of which corresponds to the silicon photomultiplier tube. The processing circuit uses the signal adjustment circuits to adjust the scintillation pulse signal to have different decay times.

[0031] According to some embodiments, the signal conditioning circuit includes a passive RC circuit, a passive LC circuit, an active circuit, or an analog signal filter.

[0032] According to some embodiments, the plurality of scintillation crystals have different decay time constants; and / or the plurality of silicon photomultiplier tubes have different recovery times, so that the plurality of scintillation pulse signals have different decay times.

[0033] According to some embodiments, the sizes of the scintillator crystal and the silicon photomultiplier tube match, and the scintillator crystal and the silicon photomultiplier tube are coupled in a one-to-one manner or a many-to-many manner.

[0034] According to some embodiments, the ratio of the number of the scintillator crystals to the number of the silicon photomultiplier tubes is 3 to 2 or a multiple of 3 to 2, and the scintillator crystals and the silicon photomultiplier tubes are coupled in a ratio of 3 to 2 or a multiple of 3 to 2.

[0035] According to some embodiments, the processing circuit groups and sums signals from a plurality of the scintillation pulses.

[0036] According to some embodiments, the sampling circuit includes an analog-to-digital conversion circuit, and the analog-to-digital conversion circuit includes an ADC sampling circuit and an MVT sampling circuit.

[0037] According to some embodiments, the detector further comprises: a digital signal processing unit configured to calculate a decay time of the digital signal, the scintillation pulse signal, or the summed scintillation pulse signal, and determine a position of the scintillation crystal corresponding to the digital signal using the decay time.

[0038] According to one aspect of the present application, a detector is proposed, comprising: one or more processors; a storage device for storing a computer program; when the computer program is executed by the one or more processors, the one or more processors implement the method as described above.

[0039] According to one aspect of the present application, a computer-readable storage medium is provided, on which program instructions are stored. When the program instructions are executed, the method described above is implemented.

[0040] According to some exemplary embodiments of the present application, by outputting multiplexed scintillation pulse signals with different decay times, high multiplexing efficiency can be achieved, effectively reducing the number of subsequent processing and acquisition channels. Furthermore, according to other embodiments of the present application, the spatial resolution of the detector can be improved by coupling SiPMs with smaller crystals. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments.

[0042] Figure 1 A flow chart of a method for digitizing a scintillation pulse according to an exemplary embodiment of the present application is shown.

[0043] Figure 2 A specific implementation of a method for digitizing scintillation pulses according to an exemplary embodiment of the present application is shown.

[0044] Figure 3 Another specific implementation of the scintillation pulse digitization method according to an exemplary embodiment of the present application is shown.

[0045] Figure 4 A block diagram of a detector using a digitization method using scintillation pulses according to an exemplary embodiment of the present application is shown.

[0046] Figure 5 A detector block diagram of another digitization method using scintillation pulses according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0047] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be embodied in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the example embodiments to those skilled in the art. Like reference numerals in the drawings represent like or similar parts, and thus repetitive description thereof will be omitted.

[0048] The described features, structures or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced without one or more of these specific details, or other modes, components, materials, devices or operations may be employed. In these cases, well-known structures, methods, devices, implementations, materials or operations will not be shown or described in detail.

[0049] The flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, while others may be combined or partially combined. Therefore, the actual execution order may vary depending on the actual situation.

[0050] The terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish between different objects, not to describe a particular order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0051] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

[0052] Figure 1 A flow chart of a method for digitizing a scintillation pulse according to an exemplary embodiment of the present application is shown. Figure 1 , a method for digitizing a scintillation pulse according to an exemplary embodiment of the present application is described in detail.

[0053] according to Figure 1 In the embodiment shown, the method for digitizing scintillation pulses includes at least the following steps:

[0054] Step S1: Acquire a plurality of scintillation pulse signals with different decay times.

[0055] Step S2: Add the multiple scintillation pulse signals acquired in step S1 and output the added scintillation pulse signal.

[0056] Step S3: sampling the summed scintillation pulse signal to obtain a digital signal.

[0057] According to some embodiments of the present application, in the above-mentioned step S1, a corresponding detector can be used to obtain multiple scintillation pulse signals with different decay times. For example, the detector includes multiple scintillation crystals and multiple silicon photomultiplier tubes (SiPMs) respectively coupled to the multiple scintillation crystals. The scintillation crystals respond to the incident particles and generate visible light signals. The multiple silicon photomultiplier tubes respond to the visible light signals from the multiple scintillation crystals to generate scintillation pulse signals.

[0058] According to some embodiments of the present application, the scintillation crystals and silicon photomultiplier tubes used in step S1 can be of the same size, in which case the scintillation crystals and silicon photomultiplier tubes are coupled one-to-one. Alternatively, the scintillation crystals and silicon photomultiplier tubes can be of the same size, in which case the scintillation crystals and silicon photomultiplier tubes can be coupled in a many-to-many or many-to-one manner. For example, the ratio of the number of cross-sections of the scintillation crystal array and the silicon photomultiplier tube array in the row and column directions is 3:2 or a multiple of 3:2, and the scintillation crystals and silicon photomultiplier tubes are coupled in a 3:2 or a multiple of 3:2 ratio in the row and column directions.

[0059] According to some embodiments of the present application, in the above step S1, the scintillation crystals in the detector may be configured to have different decay time constants, so that the scintillation pulse signals output by the corresponding coupled silicon photomultiplier tubes have different decay times.

[0060] According to some embodiments of the present application, in the above-mentioned step S1, the multiple silicon photomultiplier tubes in the detector can be set to have different recovery times, that is, they can be set to silicon photomultiplier tubes with different micro-cell sizes, so that the scintillation pulse signals output by the multiple silicon photomultiplier tubes have different decay times.

[0061] According to some embodiments of the present application, in the above-mentioned step S1, several scintillation crystals in the detector can be set to have different decay time constants, and at the same time, multiple silicon photomultiplier tubes in the detector can be set to have different recovery times, so that the scintillation pulse signals output by the multiple silicon photomultiplier tubes have different decay times.

[0062] According to some embodiments of the present application, in the above-mentioned step S1, when the scintillation crystals / arrays are made of the same material, a signal adjustment circuit connected to the silicon photomultiplier tube can also be used to obtain multiple scintillation pulse signals with different decay times. The signal adjustment circuit adjusts the scintillation pulse signals output by the silicon photomultiplier tube to have different decay times, and then inputs them into step S2 for addition.

[0063] According to some embodiments of the present application, the signal adjustment circuit may adopt a passive RC circuit, a passive LC circuit, or an active circuit. Those skilled in the art should understand that whether it is a passive RC circuit, a passive LC circuit, or an active circuit, they are all within the skill of those skilled in the art based on the teachings of the present application. The function of the above-mentioned circuit in the present application is to adjust the decay time of the scintillation pulse signal output by the silicon photomultiplier tube. Taking the passive RC circuit as an example, by setting different RC parameters, the output signal of the silicon photomultiplier tube can have different decay times after passing through the passive RC circuit.

[0064] According to some embodiments of the present application, in the above step S1, a band-stop, high-pass or low-pass analog signal filter may be set so that the acquired scintillation pulse signal has different frequencies.

[0065] Those skilled in the art should understand that, in the above-mentioned step S1, whether a passive RC circuit, a passive LC circuit or an active circuit is used, its purpose in this application is to adjust the scintillation pulse signal output by the silicon photomultiplier tube / array into a scintillation pulse signal with different decay times. Therefore, any method that can achieve different decay times of the scintillation pulse signal output by the silicon photomultiplier tube / array or convert the output scintillation pulse signal into a signal with different decay times falls within the scope of the present invention and will not be described in detail here.

[0066] According to some embodiments of the present application, before the above step S1, the present application may further include step S0: setting parameters of each component / circuit in the detector according to actual needs, so as to achieve the purpose of obtaining scintillation pulse signals with different decay times.

[0067] According to some embodiments of the present application, in step S2, multiple scintillation pulse signals with different decay times may be grouped, and then the scintillation pulse signals within each group may be summed to output multiple scintillation pulse signals. The specific number of groups may be adjusted based on chip performance; higher chip performance may require fewer groups.

[0068] According to some exemplary embodiments of the present application, in step S3, an analog-to-digital conversion circuit may be used to sample the summed scintillation pulse signals to obtain a digital signal. Specifically, the analog-to-digital conversion circuit may be an ADC sampling circuit or an MVT sampling circuit.

[0069] According to some example embodiments of the present application, the method for digitizing scintillation pulses may further include step S4: analyzing the obtained digital signal, calculating the decay time corresponding to the scintillation pulse signal, and determining the position of the corresponding scintillation crystal.

[0070] According to some exemplary embodiments of the present application, in step S4, any programmable processor can be used to calculate the decay times included in the multiple digital signals and use the decay times to determine the positions of the corresponding multiple SiPMs. Because the positions of the scintillation crystals correspond to the positions of the SiPMs, the positions of the crystal strips can be determined using the SiPM positions.

[0071] According to some embodiments of the present application, in the above step S4, digital integration can also be used to calculate the energy, position, time and other information contained in each digital signal. For example, edge detection can be used to obtain the time information of each digital signal.

[0072] According to some embodiments of the present application, if the scintillation pulse signals obtained using a band-stop, high-pass or low-pass analog signal filter in the above-mentioned step S1 have different frequency differences, then in step S4, the positions of multiple scintillation crystals can be determined according to the frequency domain differences of the scintillation pulse signals using Fourier transform.

[0073] according to Figure 1 The scintillation pulse digitization method shown can perform channel multiplexing during the scintillation pulse digitization process. Even when a small number of SiPM output channels are multiplexed, the multiplexing ratio is higher than that of the prior art.

[0074] Taking the multiplexing of 4 SiPM output channels as an example, Figure 1 The signal processing method shown in the figure outputs one pulse sum signal when multiplexing. However, using the center-of-gravity weighting method for multiplexing requires four pulse signals, and using the strip-line method for multiplexing requires two pulse signals.

[0075] In addition, compared with the Strip-line method, Figure 1 The signal processing method shown is also applicable to detectors whose scintillation crystal size is smaller than that of SiPM. It can not only multiplex the output signal channels but also improve the spatial resolution of the detector.

[0076] The following example illustrates how to determine the position of the scintillation crystal when the scintillation crystal and the silicon photomultiplier tube are coupled one-to-one.

[0077] Figure 2A specific implementation of a method for digitizing scintillation pulses according to an exemplary embodiment of the present application is shown, wherein the scintillation crystals in the detector are coupled to the SiPM in a one-to-one manner, each SiPM is connected to a passive RC circuit, and multiple passive RC circuits are simultaneously connected to a summing circuit.

[0078] First, a passive RC circuit is used to convert the scintillation pulse signals output by n SiPMs into n scintillation pulse signals with different decay times. These scintillation pulse signals are then transmitted to a summing circuit for summation. An analog-to-digital conversion circuit, such as an ADC or MVT sampling circuit, directly samples the summed scintillation pulse signals to obtain a digital signal.

[0079] Subsequently, digital pulse processing methods are used to analyze the obtained digital signal and obtain the corresponding position, energy or time information. For example, digital integration is used to calculate the energy of the scintillation pulse, and edge detection is used to obtain the time information.

[0080] Finally, digital signal processing methods are used to calculate the decay time corresponding to each digital signal, and the corresponding SiPM position information is determined based on the decay time. Since the scintillation crystal bar position corresponds to the SiPM one-to-one, the scintillation crystal bar position and the SiPM position are determined simultaneously.

[0081] Figure 3 Another specific implementation of a scintillation pulse digitization method according to an exemplary embodiment of the present application is shown. In this embodiment, scintillation crystals in a detector are coupled to SiPMs in a many-to-one fashion. For example, a 3×3 array of scintillation crystals is coupled to a 2×2 array of SiPMs, with each SiPM corresponding to multiple scintillation crystal bars. Similarly, each SiPM is connected to a passive RC circuit, and multiple passive RC circuits are simultaneously connected to a summing circuit.

[0082] First, a passive RC circuit is used to convert the scintillation pulse signals output by the four SiPMs into four scintillation pulse signals with different decay times. These scintillation pulse signals are then sent to a summing circuit for summation. An analog-to-digital conversion circuit, such as an ADC or MVT, directly samples the summed scintillation pulse signal to obtain a digital signal.

[0083] Then, digital pulse processing methods are used to analyze the obtained digital signal and obtain the corresponding position, energy or time information. For example, digital integration methods are used to calculate the energy of the scintillation pulse, and edge detection methods are used to obtain time information.

[0084] Finally, a digital signal processing method is used to calculate the decay time corresponding to each digital signal, and the corresponding SiPM position information is determined according to the decay time.

[0085] and Figure 2 The difference between the embodiments is that Figure 3 The position of the scintillating crystal strip and the SiPM are coupled in a many-to-one manner, and the determination of the crystal strip position and the SiPM position is different. Figure 3 In the illustrated embodiment, when particles deposit energy in the crystal strips located at the four corners of the scintillation crystal array, only one SiPM will output a corresponding scintillation pulse signal. Therefore, the decay time of the scintillation pulse output by the summing circuit corresponds to the decay time of the scintillation pulse generated by that SiPM. When particles deposit energy in the crystal strip located in the center, four SiPMs will simultaneously output scintillation pulse signals, and the decay time of the scintillation pulse output by the summing circuit will correspond to the sum of the decay times of the scintillation pulses generated by these four SiPMs. When particles deposit energy in the other four crystals, two corresponding SiPMs will simultaneously output scintillation pulse signals, and the decay time of the scintillation pulse output by the summing circuit will correspond to the sum of the decay times of the scintillation pulses generated by these two SiPMs. Therefore, for a detector design using 2×2 SiPMs coupled to 3×3 crystals, this method can be used to identify the crystal location corresponding to the signal based on the decay time characteristics of the summed scintillation pulse signal. Similarly, this method can be extended to apply to more signal channels, which will not be further described here.

[0086] According to another embodiment of the present application, the method for digitizing scintillation pulses may further include the following steps:

[0087] Step S0 ′: scintillation crystals and silicon photomultiplier tubes are arranged in a many-to-many coupling mode, wherein the effective cross-sectional area of the scintillation crystals is smaller than the effective cross-sectional area of the silicon photomultiplier tubes.

[0088] Step S1 ′: acquiring a plurality of scintillation pulse signals with different decay times generated by a silicon photomultiplier tube.

[0089] Step S2 ′: summing the multiple scintillation pulse signals acquired in step S1 ′ and outputting a summed scintillation pulse signal.

[0090] Step S3 ′: sampling the summed scintillation pulse signal to obtain a digital signal.

[0091] Compared with the above embodiment, this embodiment not only effectively improves the spatial resolution of the detector but also ensures a higher channel multiplexing efficiency by setting the scintillation crystals and silicon photomultiplier tubes in a many-to-many coupling manner and combining the output multiplexing of scintillation pulse signals with different decay times.

[0092] According to another embodiment of the present application, the method for digitizing scintillation pulses may further include the following steps:

[0093] Step S0": arranging a many-to-many coupling mode between the scintillation crystal and the silicon photomultiplier tube, wherein the effective cross-sectional area of the scintillation crystal is smaller than the effective cross-sectional area of the silicon photomultiplier tube.

[0094] Step S1": Acquire multiple scintillation pulse signals with different decay times.

[0095] Step S2": summing the multiple scintillation pulse signals acquired in step S1 and outputting a summed scintillation pulse signal.

[0096] Step S3": sampling the summed scintillation pulse signal to obtain a digital signal.

[0097] Step S4": Analyze the obtained digital signal, calculate the decay time corresponding to the scintillation pulse signal, and determine the position of the corresponding scintillation crystal.

[0098] Compared with the above embodiments, this embodiment can quantify the digital signals collected by the detector by setting the scintillation crystals and silicon photomultiplier tubes in a many-to-many coupling mode and combining the output multiplexing of scintillation pulse signals with different decay times. This helps to establish a database and conduct intelligent processing training, and can ensure a high channel multiplexing efficiency, effectively improving the spatial resolution of the detector.

[0099] Those skilled in the art will appreciate that similar steps or technical means in the above embodiments can be used interchangeably across different embodiments. For example, in all embodiments, any programmable processor can be used to calculate the decay times contained in multiple digital signals and use the decay times to determine the positions of the corresponding multiple SiPMs. Because the positions of the scintillator crystals correspond to the positions of the SiPMs, the positions of the crystal strips can be determined using the SiPM positions.

[0100] Figure 4 A detector block diagram according to an exemplary embodiment of the present application is shown. Figure 4 A detector according to an exemplary embodiment of the present application is described in detail.

[0101] like Figure 4 The detector shown includes a plurality of scintillation crystals 401 , a plurality of silicon photomultiplier tubes 403 , a processing circuit 405 , and a sampling circuit 407 .

[0102] Multiple scintillation crystals 401 are used to receive incident particles and generate visible light signals in response to the incident particles. Multiple silicon photomultiplier tubes 403 are coupled to the multiple scintillation crystals and, in response to the visible light signals generated by the multiple scintillation crystals, generate scintillation pulse signals. These scintillation pulse signals typically have a relatively fast rising edge and a relatively slow falling edge. A processing circuit 405 sums the scintillation pulse electrical signals from the multiple silicon photomultiplier tubes, where the summed scintillation pulse electrical signals have different decay times. A sampling circuit 407 samples the summed scintillation pulse signals to obtain multiple digital signals.

[0103] According to some embodiments, the sizes of the scintillator crystal and the silicon photomultiplier tube are matched, e.g. Figure 4 In the detector shown, the scintillation crystals and silicon photomultiplier tubes are of the same size and are coupled in a one-to-one manner. Each scintillation crystal can only transmit the converted visible light signal to a unique corresponding silicon photomultiplier tube.

[0104] According to some embodiments, the scintillator crystal and the silicon photomultiplier tube are of different sizes, e.g. Figure 4 In the detector shown, the scintillation crystals and silicon photomultiplier tubes can be coupled in a one-to-many, many-to-one, or many-to-many manner. Multiple scintillation crystals can transmit the converted visible light signals to the same corresponding silicon photomultiplier tube. For example, the scintillation crystals are arranged in a 3n×3n array, and the silicon photomultiplier tubes are arranged in a 2n×2n array (n is a natural number). The coupling cross-sections of the scintillation crystal array and the silicon photomultiplier tube array are the same size, resulting in a ratio of 3 to 2 or a multiple of 3 to 2 in the row or column direction.

[0105] According to some example embodiments of the present application, multiple scintillation crystals 401 can be set to have different decay time constants, so that the scintillation pulse signals output by the corresponding silicon photomultiplier tubes have different decay times. Accordingly, the processing circuit 405 no longer needs to convert the decay time, but only needs to add and output these scintillation pulse signals with different decay times.

[0106] According to some example embodiments of the present application, the multiple silicon photomultiplier tubes 403 can be a SiPM array, which utilizes silicon photomultiplier tubes with different recovery times, that is, different micro-cell sizes, so that the scintillation pulse signals output by the multiple silicon photomultiplier tubes 403 in the SiPM array have different decay times.

[0107] According to some embodiments, multiple scintillation crystals 401 with different decay time constants and multiple silicon photomultiplier tubes 403 with different recovery times may be used simultaneously, so that the scintillation pulse signals output by the multiple silicon photomultiplier tubes 403 have different decay times.

[0108] According to some exemplary embodiments of the present application, the processing circuit 405 includes multiple signal adjustment circuits, each corresponding to one of the multiple silicon photomultiplier tubes 403. The processing circuit 405 uses the multiple signal adjustment circuits to adjust the scintillation pulse signals from the multiple silicon photomultiplier tubes 403 to have different decay times.

[0109] According to some embodiments of the present application, the signal adjustment circuit includes a passive RC circuit, a passive LC circuit, and an active circuit.

[0110] According to some embodiments of the present application, the signal adjustment circuit employs an RC circuit, and by adjusting RC parameters, the scintillation pulse signals within each group have different decay times. According to some embodiments, the signal adjustment circuit further includes a passive LC circuit and an active circuit for adjusting the scintillation pulse signals output by the silicon photomultiplier tube 403 or the silicon photomultiplier tube array into scintillation pulse signals with different decay times.

[0111] Those skilled in the art will appreciate that, regardless of whether the circuit is a passive RC circuit, a passive LC circuit, or an active circuit, the purpose of this application is to adjust the scintillation pulse signal output by the silicon photomultiplier tube / array into a scintillation pulse signal having different decay times. Therefore, any method / circuit capable of achieving different decay times for the scintillation pulse signal output by the silicon photomultiplier tube / array, or converting the output scintillation pulse signal into a signal having different decay times, falls within the scope of the present invention and is not further described herein. For example, the signal adjustment circuit can design a suitable band-stop, high-pass, or low-pass analog signal filter to make the scintillation pulse signal have different frequencies, then perform summation and utilize Fourier transform or other methods to map the output scintillation pulse signal to the silicon photomultiplier tube channel based on the frequency domain characteristics of the scintillation pulse signal.

[0112] According to some example embodiments of the present application, a processing circuit groups scintillation pulse signals from multiple silicon photomultiplier tubes (SPMs) and sums the signals within each group. The grouping is preferably performed based on the processing capabilities of the chip / processing circuit. Scintillation pulse signals from adjacent channels or corresponding channels of the same SPM array are preferably grouped together to facilitate circuit processing. The greater the number of groups, the lower the requirements for the chip. Therefore, in practical applications, the number of groups can be selected based on actual needs.

[0113] According to some example embodiments of the present application, the processing circuit 405 includes multiple adding circuits, each of which corresponds to multiple signal adjustment circuits. The signal adjustment circuit adjusts the scintillation pulse signals from the multiple silicon photomultiplier tubes 403 into scintillation pulse signals with different decay times. The adding circuit adds the multiple scintillation pulse signals from the corresponding signal adjustment circuits and then outputs them to the sampling circuit.

[0114] According to some example embodiments of the present application, a sampling circuit samples the summed scintillation pulse signal to obtain a digital signal, which can then be used to conveniently perform data processing. According to some embodiments, the sampling circuit includes an analog-to-digital conversion circuit, such as an ADC sampling circuit or an MVT (multi-voltage threshold) sampling circuit.

[0115] According to some example embodiments of the present application, the detector may further include a digital signal processing unit configured to calculate the decay times of the multiple scintillation pulse signals and use the decay times to determine the positions of the corresponding multiple scintillation crystals. According to some embodiments, the digital signal processing unit may also be configured to calculate the time and / or energy information contained in the scintillation pulse signals, thereby facilitating the matching of coincident events or identifying different radiation sources, thereby improving the quality of the reconstructed image.

[0116] according to Figure 4 The detector shown in the figure adjusts the scintillation pulse signals output by the silicon photomultiplier tube in the detector to have different decay times and then adds them together, and then determines the position of the scintillation crystal by identifying the decay time of the summed signal. In addition, Figure 4 The scintillator crystals and silicon photomultiplier tubes in the detector shown can be coupled in a one-to-one or many-to-many manner, thereby improving the spatial resolution of the detector.

[0117] The following example illustrates how to use the scintillation crystal and silicon photomultiplier tube in a one-to-one coupling mode. Figure 4 The detector shown determines the position of the scintillation crystal.

[0118] according to Figure 4 The detector shown includes an array crystal consisting of m×n scintillator crystal bars, a SiPM array consisting of m×n SiPMs, m×n passive RC circuits, L summing circuits, and L MVT sampling circuits, where m and n are both greater than 1. The cross section of each scintillator crystal bar is coupled one-to-one with a single SiPM, the input of each passive RC circuit is connected to the output of one of the SiPMs, the input of each summing circuit is connected to the outputs of multiple passive RC circuits, and the input of each MVT sampling circuit is connected to the input of each summing circuit.

[0119] Each SiPM can output a scintillation pulse signal. These m×n scintillation pulse signals are divided into L groups (L ≥ 1). By setting different RC parameters, the decay time of the scintillation pulse signals in each group after passing through the passive RC circuit is different. This ensures that the scintillation pulse signal output by each SiPM is processed through a passive RC circuit to achieve the purpose of changing the pulse decay time. Finally, a summing circuit is used to sum the scintillation pulse signals output by each group of passive RC circuits.

[0120] L-channel MVT sampling circuits are used to collect these L summed signals. The digital processing unit calculates the corresponding pulse duration, energy, and decay time, and uses the decay time to determine the corresponding SiPM position. Since the crystal bar position and SiPM position are consistent, the crystal bar position can be determined by the SiPM position.

[0121] The following example illustrates how to use the scintillation crystal and silicon photomultiplier tube when they are multi-to-multi coupled. Figure 4 The detector shown determines the position of the scintillation crystal.

[0122] according to Figure 4 The detector shown includes an array crystal consisting of 3m×3n scintillation crystal bars, a SiPM array consisting of 2m×2n SiPMs, 2m×2n passive RC filter circuits, m×n summing circuits, and m×n MVT sampling circuits, where m and n are both not less than 1. In the row or column direction of the scintillation crystal array cross section, there are always two scintillation crystal bar cross sections that are coupled two-to-one with a single SiPM. The cross-sectional dimensions of a single 3×3 scintillation crystal array are the same as the cross-sectional area of a single 2×2 SiPM array, and they are coupled to each other. The input of each passive RC circuit is connected to the output of one of the SiPMs, the input of each summing circuit is connected to the outputs of four passive RC circuits, and the input of each MVT sampling circuit is connected to the input of each summing circuit.

[0123] By setting different RC parameters, the decay time of the scintillation pulse signals output by different SiPMs after passing through the passive RC circuit is different, so that the scintillation pulse signal output by each SiPM is processed by a passive RC circuit to achieve the purpose of changing the pulse decay time.

[0124] The output pulse signals of adjacent 2×2 arrays in the SiPM array are summed using a summing circuit and the summed signal is collected using an MVT sampling circuit.

[0125] The pulse time, energy and decay time corresponding to the digital signal obtained by the MVT sampling circuit are calculated respectively, and the corresponding SiPM position is determined according to the decay time.

[0126] Figure 5 A block diagram of another detector according to an embodiment of the present application is shown. Figure 5 The detector shown is only an example and should not limit the functions and scope of use of the embodiments of the present application.

[0127] like Figure 5 As shown, the detector is represented in the form of a general-purpose computing device. The components of the detector may include but are not limited to: at least one processor 210, at least one memory 220, a bus 230 connecting different system components (including the memory 220 and the processor 210), a display unit 240, etc. The memory 220 stores program code, which can be executed by the processor 210, so that the processor 210 performs the methods described in this specification according to various exemplary embodiments of the present application. For example, the processor 210 can execute the following Figure 1 The method shown in .

[0128] The memory 220 may include a readable medium in the form of a volatile memory unit, such as a random access memory unit (RAM) 2201 and / or a cache memory unit 2202 , and may further include a read-only memory unit (ROM) 2203 .

[0129] The memory 220 may also include a program / utility 2204 having a set (at least one) of program modules 2205, such program modules 2205 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.

[0130] Bus 230 may represent one or more of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus architectures.

[0131] The detector can also communicate with one or more external devices 300 (e.g., a keyboard, pointing device, Bluetooth device, etc.), one or more devices that enable a user to interact with the detector, and / or any device that enables the detector to communicate with one or more other computing devices (e.g., a router, modem, etc.). Such communication can occur via input / output (I / O) interface 250. Furthermore, the detector can communicate with one or more networks (e.g., a local area network (LAN), a wide area network (WAN), and / or a public network such as the Internet) via network adapter 260. Network adapter 260 can communicate with other modules of the detector via bus 230. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with the detector, including but not limited to microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0132] Through the description of the above embodiments, it is easy for those skilled in the art to understand that the example embodiments described here can be implemented by software or by combining software with necessary hardware. The technical solution according to the embodiment of the present application can be embodied in the form of a software product, which can be stored in a computer-readable storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, and includes a number of computer program instructions to enable a computing device (which can be a personal computer, a server, or a network device, etc.) to perform the above method according to the embodiment of the present application.

[0133] The software product can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can be, for example, but not limited to, a system, device or component of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination thereof. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0134] Computer-readable storage media may include a data signal propagated in baseband or as part of a carrier wave, which carries readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. The readable storage medium may also be any readable medium other than a readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device. The program code contained on the readable storage medium may be transmitted using any appropriate medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination thereof.

[0135] The program code for performing the operations of the present application can be written in any combination of one or more programming languages, including object-oriented programming languages such as Java, C++, etc., and conventional procedural programming languages such as C or similar programming languages. The program code can be executed entirely on the user computing device, partially on the user device, as a stand-alone software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0136] The computer-readable medium carries one or more program instructions. When the one or more program instructions are executed by a device, the computer-readable medium implements the aforementioned functions.

[0137] Those skilled in the art will appreciate that the above modules can be distributed in the device as described in the embodiment, or can be modified accordingly to be used in one or more devices that are uniquely different from the embodiment. The multiple modules of the above embodiments can be combined into one module, or one module can be further divided into multiple submodules.

[0138] Through the description of the above embodiments, it is easy for those skilled in the art to understand that the example embodiments described here can be implemented by software or by combining software with necessary hardware. The technical solution according to the embodiment of the present application can be embodied in the form of a software product, which can be stored in a computer-readable storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.) or on a network, and includes a number of computer program instructions to enable a computing device (which can be a personal computer, a server, or a network device, etc.) to perform the above method according to the embodiment of the present application.

[0139] The software product can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can be, for example, but not limited to, a system, device or component of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination thereof. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0140] Computer-readable storage media may include a data signal propagated in baseband or as part of a carrier wave, which carries readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. The readable storage medium may also be any readable medium other than a readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device. The program code contained on the readable storage medium may be transmitted using any appropriate medium, including but not limited to wireless, wired, optical cable, RF, etc., or any suitable combination thereof.

[0141] The program code for performing the operations of the present application can be written in any combination of one or more programming languages, including object-oriented programming languages such as Java, C++, etc., and conventional procedural programming languages such as C or similar programming languages. The program code can be executed entirely on the user computing device, partially on the user device, as a stand-alone software package, partially on the user computing device and partially on a remote computing device, or entirely on a remote computing device or server. In the case of a remote computing device, the remote computing device can be connected to the user computing device through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0142] The computer-readable medium carries one or more program instructions. When the one or more program instructions are executed by a device, the computer-readable medium implements the aforementioned functions.

[0143] Those skilled in the art will appreciate that the above modules can be distributed in the device as described in the embodiment, or can be modified accordingly to be used in one or more devices that are uniquely different from the embodiment. The multiple modules of the above embodiments can be combined into one module, or one module can be further divided into multiple submodules.

[0144] According to some exemplary embodiments of the present application, by outputting multiplexed scintillation pulse signals with different decay times, high multiplexing efficiency can be achieved, effectively reducing the number of subsequent processing and acquisition channels. This approach can be widely applied to various photoelectric conversion applications, such as PET detectors, CT detectors, gamma cameras, and high-energy physics detectors. Furthermore, the spatial resolution of the detector can be improved by coupling SiPMs with smaller crystals.

[0145] Although the present application provides the method operation steps described in the above embodiments or flow charts, more or fewer operation steps may be included in the method based on routine or no creative work. In the steps where there is no necessary causal relationship in logic, the execution order of these steps is not limited to the execution order provided in the embodiments of the present application.

[0146] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0147] The embodiments of the present application are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only intended to help understand the method and core ideas of the present application. At the same time, changes or modifications made by those skilled in the art based on the ideas of the present application, the specific implementation methods, and the scope of application of the present application, all fall within the scope of protection of the present application. In summary, the contents of this specification should not be construed as limiting the present application.

Claims

1. A method for digitizing scintillation pulses, characterized in that: The digitization method comprises the following steps: Step S1: Acquire a plurality of scintillation pulse signals with different decay times, wherein the plurality of scintillation pulse signals with different decay times are acquired using a plurality of silicon photomultiplier tubes with different recovery times, or the plurality of scintillation pulse signals with different decay times are acquired using a signal adjustment circuit; Step S2: adding the plurality of scintillation pulse signals and outputting the added scintillation pulse signal; and Step S3: sampling the summed scintillation pulse signal to obtain a digital signal.

2. The scintillation pulse digitization method according to claim 1, characterized in that: The scintillation pulse signal is obtained by converting visible light through a silicon photomultiplier tube, and the silicon photomultiplier tube and the scintillation crystal are arranged to be coupled in a one-to-one manner or a many-to-many manner.

3. The scintillation pulse digitization method according to claim 2, characterized in that: The effective cross-sectional dimensions of the scintillation crystal and the silicon photomultiplier tube are set to be the same.

4. The scintillation pulse digitization method according to claim 2, characterized in that: The effective cross-sectional size of the scintillation crystal is set to be smaller than the effective cross-sectional size of the silicon photomultiplier tube.

5. The scintillation pulse digitization method according to claim 2, characterized in that: The ratio of the number of the scintillation crystals to the number of the silicon photomultiplier tubes is set to 3 to 2 or a multiple of 3 to 2, and the scintillation crystals and the silicon photomultiplier tubes are set to be coupled at a ratio of 3 to 2 or a multiple of 3 to 2.

6. The scintillation pulse digitization method according to claim 1, characterized in that: The signal adjustment circuit includes a passive RC circuit, a passive LC circuit, an active circuit or an analog signal filter.

7. The scintillation pulse digitization method according to claim 1, characterized in that: Before step S1, scintillation pulse signals with different decay times are obtained by setting parameters of a signal adjustment circuit in the detector.

8. The scintillation pulse digitization method according to claim 1, characterized in that: In the step S2, the plurality of scintillation pulse signals with different decay times are grouped, and then the scintillation pulse signals in each group are added up to output a plurality of added scintillation pulse signals.

9. The scintillation pulse digitization method according to claim 1, characterized in that: In step S3, sampling the summed scintillation pulse signal includes: The summed scintillation pulse signal is sampled by an analog-to-digital conversion circuit, which includes an ADC sampling circuit and an MVT sampling circuit.

10. The scintillation pulse digitization method according to claim 1, characterized in that: The digitization method further comprises step S4: analyzing the digital signal, calculating the decay time corresponding to the scintillation pulse signal, and determining the position of the corresponding scintillation crystal.

11. A method for digitizing scintillation pulses, characterized in that: The method comprises the following steps: Step S0': setting a many-to-many coupling mode between the scintillation crystal and the silicon photomultiplier tube, wherein the effective cross-sectional area of the scintillation crystal is smaller than the effective cross-sectional area of the silicon photomultiplier tube; Step S1′: acquiring a plurality of scintillation pulse signals with different decay times from the silicon photomultiplier tube, wherein the plurality of scintillation pulse signals with different decay times are acquired using a plurality of silicon photomultiplier tubes with different recovery times, or the plurality of scintillation pulse signals with different decay times are acquired using a signal rectification circuit; Step S2': adding up the plurality of scintillation pulse signals and outputting the added scintillation pulse signal; and Step S3 ′: sampling the summed scintillation pulse signal to obtain a digital signal.

12. The scintillation pulse digitization method according to claim 11, characterized in that: The digitization method also includes include: Step S4 ′: analyzing the obtained digital signal, calculating the decay time corresponding to the scintillation pulse signal, and determining the corresponding position of the scintillation crystal.

13. A detector comprising a plurality of scintillation crystals and a plurality of silicon photomultiplier tubes, wherein the scintillation crystals are used to receive incident particles and generate visible light signals in response to the incident particles; the silicon photomultiplier tubes are respectively coupled to the plurality of scintillation crystals and generate scintillation pulse signals in response to the visible light signals generated by the plurality of scintillation crystals; characterized in that: The detector further comprises: a processing circuit that sums the plurality of scintillation pulse signals and outputs a summed scintillation pulse signal, wherein the scintillation pulse signals have different decay times, wherein the plurality of scintillation pulse signals with different decay times are obtained using a plurality of silicon photomultiplier tubes with different recovery times, or the plurality of scintillation pulse signals with different decay times are obtained using a signal rectification circuit; and The sampling circuit samples the summed scintillation pulse signal to obtain a digital signal.

14. The detector according to claim 13, characterized in that The processing circuit includes a plurality of signal adjustment circuits, each of which corresponds to the silicon photomultiplier tube. The processing circuit uses the signal adjustment circuits to adjust the scintillation pulse signal to have different decay times.

15. The detector according to claim 14, characterized in that The signal adjustment circuit includes a passive RC circuit, a passive LC circuit, an active circuit or an analog signal filter.

16. The detector according to claim 13, characterized in that The sizes of the scintillation crystal and the silicon photomultiplier tube are matched, and the scintillation crystal and the silicon photomultiplier tube are coupled in a one-to-one manner or a many-to-many manner.

17. The detector according to claim 13, characterized in that The ratio of the number of the scintillation crystals to the number of the silicon photomultiplier tubes is 3 to 2 or a multiple of 3 to 2, and the scintillation crystals and the silicon photomultiplier tubes are coupled in a ratio of 3 to 2 or a multiple of 3 to 2.

18. The detector according to claim 13, characterized in that The processing circuit groups and sums the scintillation pulse signals from the plurality of scintillation pulse signals.

19. The detector according to claim 13, characterized in that: The sampling circuit includes an analog-to-digital conversion circuit, and the analog-to-digital conversion circuit includes an ADC sampling circuit and an MVT sampling circuit.

20. The detector according to claim 13, characterized in that The detector further comprises: A digital signal processing unit is configured to calculate a decay time of the digital signal, the scintillation pulse signal, or the summed scintillation pulse signal, and determine a position of the scintillation crystal corresponding to the digital signal using the decay time.

21. A detector, characterized in that: include: one or more processors; a storage device for storing a computer program; When the computer program is executed by the one or more processors, the one or more processors are caused to implement the method according to any one of claims 1 to 13.

22. A computer-readable storage medium, characterized in that Program instructions are stored thereon, and when the program instructions are executed, the method according to any one of claims 1 to 13 is implemented.

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