Performance detection method and performance detection device for photon counting detector chip

Abstract

The invention relates to a performance detection method and a performance detection device for a photon counting detector chip, and relates to the technical field of photon counting detectors. The method comprises the following steps: inputting same analog current signals to a plurality of signal input ends of a photon counting detector chip; acquiring a detection signal generated by the photon counting detector chip according to the analog current signal; and determining the performance of the photon counting detector chip based on the plurality of detection signals. As the analog current signals are directly input to the signal input ends of the photon counting detector chip, the influence of a detection medium of the photon counting detector is eliminated, and compared with a technical scheme of directly detecting the photon counting detector by using X rays, the performance detection precision of the photon counting detector chip is improved.

Description

Technical Field

[0001] The present application relates to the technical field of photon counting detectors, and in particular to a performance detection method and a performance detection device for a photon counting detector chip. Background Art

[0002] Photon counting CT (PCCT) is an important trend in the development of CT. Compared with traditional CT based on energy integrating detector (EID), the signal detected by EID is proportional to the total energy of X-ray photons and cannot distinguish between low-energy and high-energy photons. The photon counting detector (PCD) in PCCT can record each detected photon and distinguish between high and low photon energy, thereby improving the energy resolution capability.

[0003] In the process of PCD photon counting, photons interact with the PCD detection medium (such as cadmium telluride crystal, cadmium zinc telluride crystal) and deposit energy, which will be directly converted into electrical signals and used as input signals for PCD chips. PCD chips are generally equipped with a large number of signal input channels. Due to the limitations of the manufacturing process, the performance of different channels cannot be completely consistent. Therefore, in order to eliminate the inconsistency of performance between channels, the performance of different channels needs to be tested and calibrated to improve the consistency of PCD detection.

[0004] In the related art, X-rays are directly used to detect photon counting detectors, thereby indirectly completing the performance detection of photon counting detector chips. However, this method will introduce the influence of the detection medium itself, thereby reducing the performance detection accuracy of the photon counting detector chip. Summary of the invention

[0005] Based on this, it is necessary to provide a performance detection method and a performance detection device for a photon counting detector chip that can improve the performance detection accuracy of the photon counting detector chip in response to the above technical problems.

[0006] In a first aspect, the present application proposes a performance detection method for a photon counting detector chip, the method comprising: inputting the same analog current signal into multiple signal input terminals of the photon counting detector chip; obtaining a detection signal generated by the photon counting detector chip according to the analog current signal; and determining the performance of the photon counting detector chip based on multiple detection signals.

[0007] In one of the embodiments, before the step of inputting the same analog current signal to multiple signal input terminals of the photon counting detector chip, the method further includes: acquiring a digital current signal; performing digital-to-analog conversion on the digital current signal to obtain the analog current signal.

[0008] In one embodiment, the step of inputting the same analog current signal to multiple signal input terminals of the photon counting detector chip includes: copying the analog current signal to obtain multiple analog current signals; and simultaneously inputting the analog current signal to multiple signal input terminals of the photon counting detector chip.

[0009] In one embodiment, the step of inputting the same analog current signal to multiple signal input terminals of the photon counting detector chip includes: inputting the analog current signal to one of the signal input terminals of the photon counting detector chip; after the photon counting detector chip generates a corresponding detection signal, inputting the analog current signal to another signal input terminal of the photon counting detector chip until all the signal input terminals complete detection.

[0010] In one embodiment, the step of acquiring a digital current signal includes: acquiring a random number and a pulse waveform; and determining the digital current signal based on the random number and the pulse waveform.

[0011] In one embodiment, the step of obtaining a random number includes: obtaining a clock signal; and determining the random number based on the clock signal.

[0012] In the second aspect, the present application also proposes a performance detection device for a photon counting detector chip, comprising: a signal generation module for inputting the same analog current signal to multiple signal input terminals of the photon counting detector chip; a signal acquisition module for acquiring a detection signal generated by the photon counting detector chip according to the analog current signal; and a performance detection module for determining the performance of the photon counting detector chip based on multiple detection signals.

[0013] In one embodiment, the signal generating module includes: a controller, the controller is used to output a digital current signal; a digital-to-analog converter, the input end of the digital-to-analog converter is connected to the controller, the digital-to-analog converter is used to obtain the digital current signal, and perform digital-to-analog conversion on the digital current signal to obtain the analog current signal.

[0014] In one embodiment, the controller includes: a random number generation unit, which is used to output a random number; a pulse waveform generation unit, which is used to output a pulse waveform; a multiplier, whose input ends are respectively connected to the random number generation unit and the pulse waveform generation unit, and the multiplier is used to multiply the random number with the pulse waveform to obtain a random waveform; an adder, whose input end is connected to the multiplier, whose output end is connected to the digital-to-analog converter, and the adder is used to obtain the digital current signal according to the random waveform.

[0015] In one embodiment, the random number generation unit includes: a clock generator, the clock generator is used to output a clock signal; a true random number generator, the input end of the true random number generator is connected to the clock generator, the output end of the true random number generator is connected to the multiplier, and the true random number generator is used to output the random number according to the clock signal.

[0016] The performance detection method and performance detection device of the photon counting detector chip directly input the same analog current signal to multiple signal input terminals of the photon counting detector chip. At this time, the photon counting detector chip will generate a corresponding detection signal according to the analog current signal received by each signal input terminal, and finally determine the performance of the photon counting detector chip based on the multiple detection signals. Since the present application directly inputs analog current signals to multiple signal input terminals of the photon counting detector chip, the influence of the photon counting detector detection medium is eliminated. Compared with the technical solution of directly using X-rays to detect the photon counting detector, the performance detection accuracy of the photon counting detector chip is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 It is a structural schematic diagram of a photon counting detector in the related art;

[0019] Figure 2 A schematic diagram of a performance detection method in an embodiment;

[0020] Figure 3 is a schematic diagram of the structure of a photon counting detector in one embodiment;

[0021] Figure 4is a flow chart of a performance detection method in another embodiment;

[0022] Figure 5 A schematic diagram of a process of inputting an analog current signal in one embodiment;

[0023] Figure 6 A schematic diagram of a flow chart of inputting an analog current signal in another embodiment;

[0024] Figure 7 A schematic diagram of a process for determining a digital current signal in one embodiment;

[0025] Figure 8 A schematic diagram of a process for determining a random number in one embodiment;

[0026] Fig. 9 A schematic diagram of a module of a performance detection device in an embodiment;

[0027] Fig.10 is a schematic diagram of a signal generating module in one embodiment;

[0028] Fig.11 is a schematic diagram of a signal generating module in another embodiment;

[0029] Fig.12 is a schematic diagram of a current mirror circuit in one embodiment;

[0030] Fig.13 is a schematic diagram of a module of a controller in one embodiment;

[0031] Fig.14 is a waveform diagram of a pulse waveform in one embodiment;

[0032] Fig.15 is a waveform diagram of a digital current signal in one embodiment;

[0033] Fig.16 is a module schematic diagram of a controller in another embodiment;

[0034] Fig.17 is a schematic diagram of a signal generating module in yet another embodiment;

[0035] Description of reference numerals:

[0036] Signal generating module 210, signal acquiring module 220, performance detecting module 230, controller 211, digital-to-analog converter 212, signal copier 213, random number generating unit 241, pulse waveform generating unit 242, multiplier 243, adder 244, clock generator 245, true random number generator 246. DETAILED DESCRIPTION

[0037] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0039] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element, or connected to the other element through an intermediate element. In addition, the "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if there is transmission of electrical signals or data between the connected objects.

[0040] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0041] The performance detection method and performance detection device of the photon counting detector chip of the embodiment of the present application are used to detect the performance of the photon counting detector chip. Figure 1 As shown, the photon counting detector is composed of a photon counting detector chip and a photon counting detector detection medium. The photon counting detector chip is provided with a plurality of signal input terminals, and a plurality of pixels are correspondingly provided on the photon counting detector detection medium, and the pixels are connected to the signal input terminals. When the photon counting detector is working, the X-rays incident into the detection medium of the photon counting detector are absorbed and directly converted into electrical signals, and the electrical signals are transmitted to the signal input terminal through the pixels, so as to be received by the photon counting detector chip. In the related art, when the performance of the photon counting detector chip is tested, the complete photon counting detector is directly irradiated with X-rays, thereby indirectly completing the performance test of the photon counting detector chip. However, this method will introduce the influence of the photon counting detector detection medium itself, thereby reducing the performance test accuracy of the photon counting detector chip.

[0042] Based on this, the present application provides a performance detection method and a performance detection device for a photon counting detector chip, which can improve the performance detection accuracy of the photon counting detector chip.

[0043] In one embodiment, Figure 2 As shown, a performance detection method for a photon counting detector chip is provided, including but not limited to the following steps:

[0044] Step S110: inputting the same analog current signal to multiple signal input terminals of the photon counting detector chip.

[0045] Specifically, when the photon counting detector chip is tested for performance, the photon counting detector chip can be in an incomplete package or a fully packaged state. When the photon counting detector chip is incompletely packaged, the photon counting detector chip is not connected to the photon counting detector detection medium. At this time, multiple signal input terminals of the photon counting detector chip are exposed, and analog current signals can be input to the multiple signal input terminals of the photon counting detector chip through direct contact with external electrodes. When the photon counting detector chip is fully packaged, the photon counting detector chip is connected to the photon counting detector detection medium. At this time, if Figure 3 As shown, a connecting medium can be provided between the signal input terminal and the pixel, and the connecting medium can be used as an extraction electrode, and an analog current signal can be input to multiple signal input terminals of the photon counting detector chip through the extraction electrode. In the case where the photon counting detector is provided with a connecting medium, the photon counting detector can be used normally for a period of time, and then the performance detection method of the present application can be performed to obtain the performance of the photon counting detector after use.

[0046] When inputting the same analog current signal to multiple signal input terminals of the photon counting detector chip, there are many ways. For example, an analog current signal can be input to each signal input terminal in sequence according to the arrangement order of the signal input terminals of the photon counting detector chip until all signal input terminals are input. Alternatively, the same analog current signal can be input to all signal input terminals at the same time. The analog current signal is a continuously changing current value, and the analog current signal is used to simulate the current signal received by the photon counting detector chip when it is working.

[0047] Step S120, obtaining a detection signal generated by the photon counting detector chip according to the analog current signal.

[0048] Specifically, after the signal input end of the photon counting detector chip receives the analog current signal, the analog current signal is processed by the internal signal processing circuit, such as signal amplification, signal discrimination, photon counting, time measurement, etc., to generate a corresponding detection signal, which is generally a digital signal. It is understandable that the photon counting detector chip will generate a corresponding detection signal according to the analog current signal received at each signal input end. Due to differences in the manufacturing process of the photon counting detector chip, the generated detection signals may be different.

[0049] Step S130 , determining the performance of the photon counting detector chip based on the multiple detection signals.

[0050] Specifically, after the photon counting detector chip generates multiple detection signals based on multiple analog current signals, the performance of the photon counting detector chip can be determined by comparing the differences between the multiple detection signals. The performance of the photon counting detector chip is used to indicate the consistency of multiple signal input terminals, for example, sensitivity consistency (whether the response to the analog current signal is consistent), time resolution consistency (whether the ability to represent the photon arrival time represented by the analog current signal is consistent), maximum counting rate consistency (whether the maximum number of photons that can be processed per unit time represented by the analog current signal is consistent), etc. It can be understood that the smaller the difference between the multiple detection signals, the better the performance of the photon counting detector chip. In some embodiments, when the photon counting detector chip is not fully packaged, the photon counting detector chip can also be calibrated according to the multiple detection signals to improve the consistency of the photon counting detector chip.

[0051] The above-mentioned performance detection method of the photon counting detector chip directly inputs the same analog current signal to multiple signal input terminals of the photon counting detector chip. At this time, the photon counting detector chip will generate a corresponding detection signal according to the analog current signal received by each signal input terminal, and finally determine the performance of the photon counting detector chip based on the multiple detection signals. Since the present application directly inputs analog current signals to multiple signal input terminals of the photon counting detector chip, the influence of the detection medium of the photon counting detector is eliminated. Compared with the technical solution of directly using X-rays to detect the photon counting detector, the performance detection accuracy of the photon counting detector chip is improved.

[0052] In one embodiment, Figure 4 As shown, in step S110, before the step of inputting the same analog current signal to multiple signal input terminals of the photon counting detector chip, the performance detection method further includes:

[0053] Step S140, obtaining a digital current signal;

[0054] Step S150, performing digital-to-analog conversion on the digital current signal to obtain an analog current signal.

[0055] Specifically, the analog current signal in this embodiment is obtained by performing digital-to-analog conversion on the digital current signal. The digital current signal can be obtained by a processor or an analog-to-digital converter, and the digital current signal represents the magnitude of the current in the form of discrete numerical values. After performing digital-to-analog conversion on the digital current signal, a continuous analog current signal proportional to the numerical value can be obtained. The present application obtains the analog current signal of the input photon counting detector chip through the digital current signal. Since the digital current signal is represented by a precise numerical value, the digital current signal has inherent accuracy and repeatability. When the analog current signal is input to the signal input end of the photon counting detector chip in sequence, it can be ensured that multiple analog current signals are basically the same. In this embodiment, the digital current signal can also be conveniently programmed and modified through software or hardware to obtain analog current signals of various sizes and waveforms.

[0056] In one embodiment, Figure 5 As shown, in step S110, the step of inputting the same analog current signal to multiple signal input terminals of the photon counting detector chip includes:

[0057] Step S111, copying the analog current signal to obtain multiple analog current signals.

[0058] Specifically, in this embodiment, when the same analog current signal is input to multiple signal input terminals of the photon counting detector chip, the analog current signal is first copied to obtain multiple identical analog current signals. When copying the analog current signal, a current transmitter, a current mirror circuit, a signal current module, etc. with current copying capability can be used.

[0059] Step S112, simultaneously inputting analog current signals to multiple signal input terminals of the photon counting detector chip.

[0060] Specifically, when multiple analog current signals are obtained, the analog current signals can be simultaneously input into multiple signal input terminals of the photon counting detector chip. By simultaneously inputting analog current signals into multiple signal input terminals of the photon counting detector chip, the efficiency of the performance detection of the photon counting detector chip can be improved.

[0061] In one embodiment, Figure 6 As shown, in step S110, the step of inputting the same analog current signal to multiple signal input terminals of the photon counting detector chip includes:

[0062] Step S113, inputting an analog current signal to a signal input terminal of the photon counting detector chip.

[0063] Specifically, in this embodiment, when the same analog current signal is input to multiple signal input terminals of the photon counting detector chip, the analog current signal is first input to one signal input terminal of the photon counting detector chip.

[0064] Step S114, after the photon counting detector chip generates a corresponding detection signal, an analog current signal is input to another signal input terminal of the photon counting detector chip until all signal input terminals complete the detection.

[0065] Specifically, after receiving the analog current signal, a signal input terminal of the photon counting detector chip performs signal amplification, signal discrimination, photon counting, time measurement and other processing on the analog current signal according to the internally set signal processing circuit, thereby generating a corresponding detection signal, and then inputs the same analog current signal to another signal input terminal of the photon counting detector chip, thereby generating another corresponding detection signal. By cyclically executing the above steps, multiple detection signals can be obtained, thereby completing the detection of all signal input terminals. It can be understood that after generating a detection signal, it can be stored in the memory, and when the detection signal needs to be obtained in step S120, it can be directly obtained from the memory.

[0066] In one embodiment, Figure 7 As shown, in step S140, the step of obtaining the digital current signal includes:

[0067] Step S141, obtaining random numbers and pulse waveforms.

[0068] Specifically, in the present embodiment, in the process of acquiring the digital current signal, the random number and the pulse waveform are first acquired. The random number can be a random value from 0 to N. The random number is used to adjust the amplitude, frequency and other parameters of the pulse waveform, thereby changing the specific parameter values ​​of the pulse waveform, and through the randomness of the random number, the performance of the photon counting detector chip under different types of analog current signals can be better detected. The random number can be generated by a true random number generator or a pseudo-random number generator. The true random number generator is used to generate random numbers based on physical random phenomena or processes. These phenomena or processes have inherent randomness, making the random number unpredictable. The pseudo-random number generator is used to generate a series of seemingly random numbers based on a deterministic algorithm and an initial seed. When a pseudo-random number generator is used, its generation speed is fast and easy to implement. The pulse waveform is the unit height crystal output pulse shape that needs to be simulated. In some embodiments, the pulse waveform is an exponential decay signal.

[0069] Step S142, determining a digital current signal based on the random number and the pulse waveform.

[0070] Specifically, after obtaining the random number and the pulse waveform, a mathematical operation (multiplication and / or addition) can be performed on the pulse waveform according to the random number, so that the pulse waveform after the mathematical operation is used as a digital current signal. In some embodiments, the pulse waveform can be multiplied by the random number to obtain a random waveform with an unfixed waveform. After obtaining the random waveform, the random waveform can be cached. If the next random waveform has arrived before the previous random waveform has been fully output, at this time, the two random waveforms can be directly superimposed and used as a digital current signal.

[0071] In one embodiment, Figure 8 As shown, in step S141, the step of obtaining a random number includes:

[0072] Step S143, obtaining a clock signal;

[0073] Step S144, determining a random number based on the clock signal.

[0074] Specifically, in the present embodiment, in the process of obtaining a random number, a clock signal is first obtained, and then the random number is determined based on the clock signal. The clock signal is used to synchronize and control the operation of the circuit, and it is usually presented in a high-level and low-level sequence of a fixed frequency. In some embodiments, the clock signal can be obtained by a quartz crystal oscillator. In some other embodiments, the frequency, duty cycle and other parameters of the clock signal can also be adjusted by a specific circuit to meet the needs of different scenarios. In some embodiments, the clock signal is a clock pulse that obeys a Poisson distribution, which is used to simulate the starting moment of the generation of a photon event. In the process of determining a random number based on a clock signal, the clock signal can be used as a random seed, and the random seed is the starting point in the random number generation process, and different random seeds will generate different random numbers.

[0075] It should be understood that, although the various steps in the flowcharts involved in the above-mentioned embodiments are displayed in sequence according to the indication of the arrows, these steps are not necessarily executed in sequence according to the order indicated by the arrows. Unless there is a clear explanation in this article, the execution of these steps is not strictly limited in order, and these steps can be executed in other orders. Moreover, at least a part of the steps in the flowcharts involved in the above-mentioned embodiments can include multiple steps or multiple stages, and these steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these steps or stages is not necessarily carried out in sequence, but can be executed in turn or alternately with other steps or at least a part of the steps or stages in other steps.

[0076] In one embodiment, Fig. 9As shown, the present application also proposes a performance detection device for a photon counting detector chip, which is used to execute the performance detection method in the above embodiment, and the performance detection device includes: a signal generation module 210, which is used to input the same analog current signal to multiple signal input terminals of the photon counting detector chip; a signal acquisition module 220, which is used to obtain a detection signal generated by the photon counting detector chip according to the analog current signal; and a performance detection module 230, which is used to determine the performance of the photon counting detector chip based on multiple detection signals.

[0077] Specifically, in the performance detection device of the embodiment of the present application, the output end of the signal generation module 210 is connected to multiple signal input ends of the photon counting detector chip, and is used to input the same analog current signal to the multiple signal input ends of the photon counting detector chip. When the same analog current signal is input to the multiple signal input ends of the photon counting detector chip, it can be done in a variety of ways. For example, an analog current signal can be input to each signal input end in turn according to the arrangement order of the signal input ends of the photon counting detector chip until all signal input ends are input. Alternatively, the same analog current signal is input to all signal input ends at the same time. The analog current signal is a continuously changing current value, and the analog current signal is used to simulate the current signal received by the photon counting detector chip when it is working.

[0078] The input end of the signal acquisition module 220 is connected to the output end of the photon counting detector chip, and is used to obtain the detection signal generated by the photon counting detector chip according to the analog current signal. After the signal input end of the photon counting detector chip receives the analog current signal, the analog current signal is processed by signal amplification, signal discrimination, photon counting, time measurement, etc. according to the internal signal processing circuit, so as to generate a corresponding detection signal, which is generally a digital signal. It can be understood that the photon counting detector chip will generate a corresponding detection signal according to the analog current signal received by each signal input end. Due to the differences in the manufacturing process of the photon counting detector chip, the generated detection signals may be different.

[0079] The input end of the performance detection module 230 is connected to the output end of the signal acquisition module 220 to receive multiple detection signals and determine the performance of the photon counting detector chip based on the multiple detection signals. After the photon counting detector chip generates multiple detection signals according to the multiple analog current signals, the performance of the photon counting detector chip can be determined by comparing the differences between the multiple detection signals. It can be understood that the smaller the difference between the multiple detection signals, the better the performance of the photon counting detector chip. In some embodiments, when the photon counting detector chip is not fully packaged, the photon counting detector chip can also be calibrated according to the multiple detection signals to improve the consistency of the photon counting detector chip.

[0080] The performance detection device of the photon counting detector chip directly inputs the same analog current signal to multiple signal input terminals of the photon counting detector chip. At this time, the photon counting detector chip will generate a corresponding detection signal according to the analog current signal received by each signal input terminal, and finally determine the performance of the photon counting detector chip based on the multiple detection signals. Since the present application directly inputs analog current signals to multiple signal input terminals of the photon counting detector chip, the influence of the detection medium of the photon counting detector is eliminated. Compared with the technical solution of directly using X-rays to detect the photon counting detector, the performance detection accuracy of the photon counting detector chip is improved.

[0081] In one embodiment, Fig.10 As shown, the signal generating module 210 includes: a controller 211 and a digital-to-analog converter 212, the controller 211 is used to output a digital current signal; the input end of the digital-to-analog converter 212 is connected to the controller 211, the digital-to-analog converter 212 is used to obtain the digital current signal, and perform digital-to-analog conversion on the digital current signal to obtain an analog current signal.

[0082] Specifically, the analog current signal in this embodiment is obtained by converting the digital current signal by the digital-to-analog converter 212. The digital current signal is output by the controller 211, and the digital current signal represents the magnitude of the current in the form of discrete numerical values. After the digital-to-analog converter 212 obtains the digital current signal and performs digital-to-analog conversion on the digital current signal, a continuous analog current signal proportional to the numerical value can be obtained. The present application obtains the analog current signal of the input photon counting detector chip through the digital current signal output by the controller 211. Since the digital current signal is represented by a precise numerical value, the digital current signal has inherent accuracy and repeatability. When the analog current signal is input to the signal input end of the photon counting detector chip in sequence, it can be ensured that multiple analog current signals are basically the same. In this embodiment, the digital current signal can also be programmed and modified by the controller 211 to obtain analog current signals of various sizes and waveforms.

[0083] In one embodiment, Fig.11 As shown, the signal generating module 210 also includes: a signal replicator 213, the input end of the signal replicator 213 is connected to the digital-to-analog converter 212, the output end of the signal replicator 213 is connected to multiple signal input ends of the photon counting detector chip, and the signal replicator 213 is used to replicate the analog current signal and obtain multiple analog current signals, and at the same time input the analog current signal to the multiple signal input ends of the photon counting detector chip.

[0084] Specifically, in this embodiment, when the same analog current signal is input to multiple signal input terminals of the photon counting detector chip, the analog current signal is first copied by the signal copier 213 to obtain multiple analog current signals. When the signal copier 213 copies the analog current signal, it can be performed by a current transmitter, a current mirror circuit, a signal current module, etc. with current copying capability. When the signal copier 213 obtains multiple analog current signals, it will simultaneously input the analog current signals to the multiple signal input terminals of the photon counting detector chip. By simultaneously inputting analog current signals to the multiple signal input terminals of the photon counting detector chip, the efficiency of the performance detection of the photon counting detector chip can be improved.

[0085] In some embodiments, Fig.12 As shown, the signal replicator 213 is configured as a current mirror circuit. The current mirror circuit includes: a plurality of MOS transistors. The drain of the MOS transistor Q1 is used to receive the analog current signal output by the digital-to-analog converter 212, and the MOS transistors Q2 to MOS transistors Qi are respectively connected to a plurality of signal input terminals of the photon counting detector chip, and after completing the replication of the analog current signal, the analog current signal is input into the signal input terminal. Fig.12 The dotted line portion omits the MOS transistors Q3 to Qi-1.

[0086] In one embodiment, the signal generating module 210 further includes: a multi-way analog switch, the input end of the multi-way analog switch is connected to the output end of the digital-to-analog converter 212 and is used to receive an analog current signal, the multi-way analog switch is used to input an analog current signal to a signal input end of the photon counting detector chip, and after the photon counting detector chip generates a corresponding detection signal, input an analog current signal to another signal input end of the photon counting detector chip until all signal input ends complete detection.

[0087] Specifically, in this embodiment, the signal generation module 210 can also use a multi-way analog switch to replace the signal replicator 213. The input end of the multi-way analog switch is connected to the output end of the digital-to-analog converter 212 and is used to receive the analog current signal. The output end of the multi-way analog switch is respectively connected to multiple signal input ends of the photon counting detector chip. Under the control of the controller 211, only one path of the multi-way analog switch is turned on at the same time, that is, only one signal input end of the photon counting detector chip can receive the analog current signal. After completing the detection of one signal input end, the photon counting detector chip will generate a corresponding detection signal. At this time, the multi-way analog switch will switch to the next path, thereby inputting the analog current signal to another signal input end of the photon counting detector chip, thereby generating another corresponding detection signal. By cyclically executing the above steps, all paths of the multi-way analog switch can be traversed, thereby obtaining multiple detection signals, so as to complete the detection of all signal input ends of the photon counting detector chip.

[0088] In one embodiment, the controller 211 is used to obtain a random number and a pulse waveform, and determine a digital current signal based on the random number and the pulse waveform.

[0089] In one embodiment, Fig.13 As shown, the controller 211 includes: a random number generating unit 241, a pulse waveform generating unit 242, a multiplier 243 and an adder 244, wherein the random number generating unit 241 is used to output a random number; the pulse waveform generating unit 242 is used to output a pulse waveform; the input end of the multiplier 243 is respectively connected to the random number generating unit 241 and the pulse waveform generating unit 242, and the multiplier 243 is used to multiply the random number with the pulse waveform to obtain a random waveform; the input end of the adder 244 is connected to the multiplier 243, the output end of the adder 244 is connected to the digital-to-analog converter 212, and the adder 244 is used to obtain a digital current signal according to the random waveform.

[0090] Specifically, in this embodiment, in the process of generating a digital current signal, the controller 211 first outputs a random number through a random number generation unit 241, and outputs a pulse waveform through a pulse waveform generation unit 242. The random number generation unit 241 can output a random number ranging from 0 to N, and the random number is used as an input of a multiplier 243. The random number is used to adjust the amplitude, frequency and other parameters of the pulse waveform, thereby changing the specific parameter value of the pulse waveform, and through the randomness of the random number, the performance of the photon counting detector chip under different types of analog current signals can be better detected. The pulse waveform output by the pulse waveform generation unit 242 is used to simulate the pulse shape output by the detection medium. The pulse waveform is stored in the memory in the form of a digital value, which can be updated through a communication interface. In some embodiments, the pulse waveform is an exponential decay signal. After receiving the random number and the pulse waveform, the multiplier 243 performs a multiplication operation on them to obtain a random waveform with an unfixed waveform. After the adder 244 receives the random waveform, the random waveform can be cached in the adder 244. If the next random waveform arrives before the previous random waveform is fully output, the adder 244 directly superimposes the two random waveforms and outputs them as a digital current signal.

[0091] Specific examples, such as Fig.14 As shown in FIG. 1 , the pulse waveform of the exponential decay signal output by the pulse waveform generating unit 242 in one embodiment is obtained by multiplying the random number and performing superposition processing through the adder 244. Fig.15 The waveform of the digital current signal is shown in FIG. 1 . It can be understood that when the length of the pulse waveform is M, the length of the digital current signal is also M.

[0092] In one embodiment, the random number generation unit 241 is used to obtain a clock signal and determine a random number based on the clock signal.

[0093] In one embodiment, Fig.16 As shown, the random number generating unit 241 includes: a clock generator 245 and a true random number generator 246, the clock generator 245 is used to output a clock signal; the input end of the true random number generator 246 is connected to the clock generator 245, the output end of the true random number generator 246 is connected to the multiplier 243, and the true random number generator 246 is used to output a random number according to the clock signal.

[0094] Specifically, in the process of generating random numbers, the random number generating unit 241 first outputs a clock signal through the clock generator 245, and the true random number generator 246 generates a random number according to the clock signal after receiving the clock signal. The clock signal is used to synchronize and control the operation of the circuit, and it is usually presented in a high-level and low-level sequence of a fixed frequency. In some embodiments, the clock signal can be obtained by a quartz crystal oscillator. In some other embodiments, the frequency, duty cycle and other parameters of the clock signal can also be adjusted by a specific circuit to meet the needs of different scenarios. In some embodiments, the clock signal is a clock pulse that obeys a Poisson distribution, which is used to simulate the starting moment of the generation of a photon event. The true random number generator 246 is used to generate random numbers based on physical random phenomena or processes, which have inherent randomness, making the random numbers unpredictable. In the process of determining random numbers based on the clock signal, the clock signal can be used as a random seed, and the random seed is the starting point in the random number generation process, and different random seeds will generate different random numbers. In some other embodiments, the random number generation unit 241 may also use a pseudo-random number generator to generate random numbers, which is used to generate a series of seemingly random numbers based on a deterministic algorithm and an initial seed. When using a pseudo-random number generator, the generation speed is faster and easier to implement.

[0095] The signal generation module 210 of the present application is described in detail below with a specific embodiment. Fig.17As shown, the signal generation module 210 includes: a controller 211, a digital-to-analog converter 212 and a current mirror circuit, and the controller 211 includes: a clock generator 245, a true random number generator 246, a pulse waveform generation unit 242, a multiplier 243 and an adder 244. The clock generator 245 can generate a periodic clock signal or a clock signal that obeys a Poisson distribution, which is used to simulate the starting time of the photon event. After receiving the clock signal, the true random number generator 246 generates a random number with a random range of 0 to N under the drive of the clock signal, and the random number is used as the input of the multiplier 243. The pulse waveform output by the pulse waveform generation unit 242 is used to simulate the pulse shape output by the detection medium. The pulse waveform is stored in the memory in the form of a digital value, which can be updated through the communication interface, and the pulse waveform is also used as the input of the multiplier 243. After receiving the random number and the pulse waveform, the multiplier 243 multiplies the random number and the pulse waveform to obtain a random waveform. After the adder 244 obtains the random waveform, the random waveform can be cached in the adder 244. If the next random waveform has arrived before the previous random waveform has been fully output, at this time, the adder 244 directly superimposes the two random waveforms and outputs them as digital current signals. After the digital-to-analog converter 212 performs digital-to-analog conversion on the received digital current signal, a continuous analog current signal proportional to the numerical value can be obtained. After receiving the analog current signal, the current mirror circuit copies the analog current signal to obtain multiple analog current signals, and finally inputs the multiple analog current signals to multiple signal input terminals of the photon counting detector chip respectively to perform performance detection on the photon counting detector chip.

[0096] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0097] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0098] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A performance detection method for a photon counting detector chip, characterized in that: The method comprises: Inputting the same analog current signal to multiple signal input terminals of the photon counting detector chip; Acquire a detection signal generated by the photon counting detector chip according to the analog current signal; A performance of the photon counting detector chip is determined based on a plurality of the detection signals.

2. The performance detection method of the photon counting detector chip according to claim 1, characterized in that: Before the step of inputting the same analog current signal to the multiple signal input terminals of the photon counting detector chip, the method further comprises: Acquire digital current signal; Perform digital-to-analog conversion on the digital current signal to obtain the analog current signal.

3. The performance detection method of the photon counting detector chip according to claim 1, characterized in that: The step of inputting the same analog current signal to multiple signal input terminals of the photon counting detector chip comprises: Copying the analog current signal to obtain a plurality of the analog current signals; The analog current signal is input to a plurality of signal input terminals of the photon counting detector chip at the same time.

4. The performance detection method of the photon counting detector chip according to claim 1, characterized in that: The step of inputting the same analog current signal to multiple signal input terminals of the photon counting detector chip comprises: Inputting the analog current signal to one of the signal input terminals of the photon counting detector chip; After the photon counting detector chip generates a corresponding detection signal, the analog current signal is input to another signal input terminal of the photon counting detector chip until all the signal input terminals complete the detection.

5. The performance detection method of the photon counting detector chip according to claim 2, characterized in that: The step of obtaining the digital current signal comprises: Get random numbers and pulse waveforms; The digital current signal is determined based on the random number and the pulse waveform.

6. The performance detection method of the photon counting detector chip according to claim 5, characterized in that: The step of obtaining a random number comprises: Get the clock signal; The random number is determined based on the clock signal.

7. A performance detection device for a photon counting detector chip, characterized in that: include: A signal generating module, used for inputting the same analog current signal to multiple signal input terminals of the photon counting detector chip; A signal acquisition module, used to acquire a detection signal generated by the photon counting detector chip according to the analog current signal; A performance detection module is used to determine the performance of the photon counting detector chip based on the multiple detection signals.

8. The performance detection device of the photon counting detector chip according to claim 7, characterized in that: The signal generating module comprises: A controller, wherein the controller is used to output a digital current signal; A digital-to-analog converter, wherein the input end of the digital-to-analog converter is connected to the controller, and the digital-to-analog converter is used to obtain the digital current signal and perform digital-to-analog conversion on the digital current signal to obtain the analog current signal.

9. The performance detection device of the photon counting detector chip according to claim 8, characterized in that: The controller comprises: A random number generation unit, wherein the random number generation unit is used to output a random number; A pulse waveform generating unit, the pulse waveform generating unit is used to output a pulse waveform; A multiplier, wherein input ends of the multiplier are respectively connected to the random number generating unit and the pulse waveform generating unit, and the multiplier is used to multiply the random number and the pulse waveform to obtain a random waveform; An adder, wherein an input end of the adder is connected to the multiplier, an output end of the adder is connected to the digital-to-analog converter, and the adder is used to obtain the digital current signal according to the random waveform.

10. The performance detection device of the photon counting detector chip according to claim 9, characterized in that: The random number generation unit comprises: A clock generator, the clock generator being used to output a clock signal; A true random number generator, wherein an input end of the true random number generator is connected to the clock generator, an output end of the true random number generator is connected to the multiplier, and the true random number generator is used to output the random number according to the clock signal.

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