PET detector output signal simulation generation method and related device

Abstract

The present invention provides a method and related device for simulating and generating the output signal of a positron emission tomography detector, wherein the method includes: obtaining the probability distribution function of the nuclide energy spectrum to be simulated and the signal energy value within a preset range; obtaining the simulated signal source to be compressed according to the probability distribution function and the signal energy value; and performing simulated compression processing on the simulated signal source using the constraint operation rule of the output signal of the positron emission tomography detector to generate an output signal simulated by the preset output channel of the positron emission tomography detector. In this way, a multi-channel signal simulation source is simulated to achieve the purpose of facilitating system development and testing.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic signal generators, and in particular to a method for simulating and generating output signals of a PET (Positron Emission Tomography) detector and a related device. Background Art

[0002] In the contact of positron emission tomography (PET) detectors using silicon photomultiplier tubes as light detectors, channel compression is often used, that is, multiple channels are distributed through a resistor network or the number of channels of the contact signal is compressed through row and column encoding, which can greatly reduce the number of channels in the subsequent processing circuit. However, the signal output from the detector to the subsequent processing circuit after channel compression and the signal directly output to the subsequent processing circuit without channel compression have different characteristic intrinsic relationships. In the development process of the subsequent processing circuit, an electronic signal generator is needed to simulate the signal output from the detector to the subsequent processing circuit after channel compression, so as to assist the research and development of the subsequent processing circuit.

[0003] The prior art already has a single-channel nuclear signal simulation source, but it cannot simulate a positron emission tomography (PET) multi-channel signal simulation source with a channel compression structure. Summary of the invention

[0004] The present invention provides a method and a related device for simulating and generating output signals of a positron emission tomography detector, which are used to simulate multi-channel signal simulation sources to facilitate system development and testing.

[0005] In order to solve the above technical problems, the first technical solution adopted by the present invention is: to provide a simulation generation method of the output signal of a positron emission tomography detector, comprising: obtaining the probability distribution function of the nuclide energy spectrum to be simulated and the signal energy value within a preset range; obtaining the simulation signal source to be compressed according to the probability distribution function and the signal energy value; and performing simulation compression processing on the simulation signal source using the constraint operation rules of the output signal of the positron emission tomography detector to generate an output signal simulated by a preset output channel of the positron emission tomography detector.

[0006] The step of obtaining the signal source to be compressed according to the probability distribution function and the signal energy value includes: obtaining the inverse function of the probability distribution function; and calculating the analog signal source according to the signal energy value and the inverse function.

[0007] The step of performing analog compression processing on the analog signal source by using the constraint operation rule of the output signal of the positron emission tomography detector to generate an output signal simulated by a preset output channel of the positron emission tomography detector includes: establishing a corresponding charge distribution model according to the constraint operation rule of the output signal of the positron emission tomography detector, wherein the number of output channels of the charge distribution model is the same as the number of output channels of the positron emission tomography detector; performing simulation according to the contact position of the analog signal source on the charge distribution model to obtain the output signals of each output channel of the charge distribution model, thereby generating the simulated output signal of the preset output channel of the positron emission tomography detector by using the output signals of each output channel of the charge distribution model.

[0008] The output energy of the analog signal source at the contact position is equal to the sum of the energies of the output signals of the output channels of the charge distribution model.

[0009] The charge distribution model is a planar charge distribution model having n×m contact channels, wherein the analog signal source is randomly contacted on any one of the n×m contact channels, and n and m are natural numbers respectively.

[0010] The charge distribution model is a three-dimensional charge distribution model having a×b×c contact channels, wherein the analog signal source is randomly contacted on any of the a×b×c channels, and a, b and c are natural numbers respectively.

[0011] The distribution of the total charge of the analog signal source to the output channel satisfies the basic Kirchhoff's current law and Kirchhoff's voltage law.

[0012] Among them, the step of simulating the contact position of the analog signal source on the charge distribution model to obtain the output signals of each output channel of the charge distribution model, and then using the output signals of each output channel of the charge distribution model to generate the simulated output signal of the preset output channel of the positron emission tomography detector includes: using a uniform function random number sampling method to simulate the contact position of the analog signal source on the charge distribution model to obtain the output signals of each output channel of the charge distribution model.

[0013] In order to solve the above technical problems, the second technical solution provided by the present invention is: providing an analog generation device for the output signal of a positron emission tomography detector, the device comprising: a processor, a memory and a digital-to-analog converter coupled to each other, wherein the memory is used to store program instructions for implementing the analog generation method for the output signal of the positron emission tomography detector described in any one of the above; the processor is used to execute the program instructions stored in the memory; and the digital-to-analog converter is used to convert the obtained digital signal into an analog signal and output it.

[0014] In order to solve the above technical problems, the third technical solution provided by the present invention is: providing a storage medium storing a program file, wherein the program file can be executed to implement the simulation generation method of the output signal of the positron emission tomography detector described in any one of the above.

[0015] The beneficial effects of the present invention are as follows: Different from the prior art, the present invention obtains the probability distribution function of the nuclide energy spectrum to be simulated and the signal energy value within a preset range; obtains the analog signal source to be compressed according to the probability distribution function and the signal energy value; and performs analog compression processing on the analog signal source using the constraint operation rule of the output signal of the positron emission tomography detector to generate an output signal simulated by the preset output channel of the positron emission tomography detector. In this way, a simulated multi-channel signal simulation source is obtained to facilitate system development and testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a flowchart of a first embodiment of a method for simulating and generating an output signal of a positron emission tomography detector according to the present invention;

[0017] Figure 2 yes Figure 1 Specific flow diagram of step S12;

[0018] Figure 3 yes Figure 1 Specific flow diagram of step S13;

[0019] Figure 4 is a schematic structural diagram of a first embodiment of a charge distribution model of the present invention;

[0020] Figure 5 is a schematic structural diagram of a second embodiment of the charge distribution model of the present invention;

[0021] Figure 6 It is a schematic structural diagram of a device for simulating and generating output signals of a positron emission tomography detector according to the present invention;

[0022] Figure 7 It is a schematic diagram of the structure of the storage medium of the present invention. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0024] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0025] See also Figure 1 , is a flow chart of a first embodiment of a method for simulating and generating output signals of a positron emission tomography detector according to the present invention. It includes:

[0026] Step S11: Obtain the probability distribution function of the nuclide energy spectrum to be simulated and the signal energy value within a preset range.

[0027] Specifically, the nuclide energy spectrum to be simulated is obtained, and the nuclide energy spectrum is transformed to obtain its corresponding probability distribution function. A signal energy value within a preset range is randomly obtained. It can be understood that the signal energy value within the range conforms to the probability distribution function of the nuclide energy spectrum. A value is randomly selected within the range as the required signal energy value. In a specific embodiment, it is assumed that the probability distribution function of the nuclide energy spectrum to be simulated is F(X).

[0028] Step S12: Obtain the analog signal source that needs to be compressed according to the probability distribution function and the signal energy value.

[0029] For details, see Figure 2 , is a specific flow chart of step S12. It includes:

[0030] Step S121: Obtain the inverse function of the probability distribution function.

[0031] Perform an inverse transformation on the probability distribution function to obtain the inverse function of the probability distribution function. Specifically, assuming that the inverse function of the probability distribution function is F -1 (X).

[0032] Step S122: Obtain the analog signal source according to the signal energy measurement value and the inverse function calculation.

[0033] Specifically, the signal energy value obtained within the preset range is substituted into the inverse function F of the probability distribution function. -1 (X), the analog signal source to be simulated is obtained by calculation. It should be noted that what is obtained by calculation at this time is the total energy of the analog signal source.

[0034] Step S13: using the constraint operation rule of the output signal of the positron emission tomography detector to perform analog compression processing on the analog signal source to generate an output signal simulated by a preset output channel of the positron emission tomography detector

[0035] For details, see Figure 3 , is a specific flow chart of step S13. It includes:

[0036] Step 131: establishing a corresponding charge distribution model according to the constraint operation rule of the output signal of the positron emission tomography detector, wherein the number of output channels of the charge distribution model is the same as the number of output channels of the positron emission tomography detector.

[0037] Specifically, when using the constraint operation rules of the output signal of the positron emission tomography detector to establish the corresponding charge distribution model, it is necessary to first know the circuit structure, that is, to know in advance the number of output channels of the positron emission tomography detector. Therefore, when establishing the charge distribution model, the number of output channels of the charge distribution model is set equal to the number of output channels of the positron emission tomography detector.

[0038] For example, in one embodiment, the number of output channels of the charge distribution model may be 4. In this case, the charge distribution model may be a planar charge distribution model. For example, in one specific embodiment, the 4 output channels of the planar charge distribution model are located at the four corners of the planar charge distribution model. Figure 4 Of course, it can also be set on the four sides of the planar charge distribution model, and there is no specific limitation.

[0039] Specifically, the planar charge distribution model has n×m contact channels, where n and m are natural numbers. After the analog signal source enters the planar charge distribution model, it randomly contacts any position of the n×m contact channels. After the analog signal source contacts any contact channel of the charge distribution model, it diffuses to the output channel according to the distance between the contact channel and the output channel, and is output from the output channel.

[0040] For example, in another embodiment, the number of output channels of the charge distribution model may be 8. In this case, the charge distribution model may be a three-dimensional charge distribution model. For example, in a specific embodiment, the eight output channels of the three-dimensional charge distribution model are located at the eight corners of the three-dimensional charge distribution model. Figure 5 As shown, A, B, C ... H are the output channels of the three-dimensional charge distribution. Of course, they can also be located at the edge of the three-dimensional charge distribution.

[0041] Specifically, the three-dimensional charge distribution model has a×b×c contact channels, where a, b, and c are natural numbers. After entering the three-dimensional charge distribution model, the analog signal source randomly contacts any position of the a×b×c contact channels. After the analog signal source contacts any contact channel of the charge distribution model, it diffuses to the output channel according to the distance between the contact channel and the output channel, and is output from the output channel.

[0042] Step S132: Perform simulation according to the contact position of the analog signal source on the charge distribution model to obtain output signals of each output channel of the charge distribution model, thereby generating a simulated output signal of a preset output channel of the positron emission tomography detector using the output signals of each output channel of the charge distribution model.

[0043] Specifically, Figure 4 The planar charge distribution model shown has n×m contact channels. When the analog signal source contacts the charge distribution model, its contact position has n×m possibilities. When it contacts a certain contact channel, it randomly contacts any contact channel of the charge distribution model, and then enters the output channel of the charge distribution model.

[0044] like Figure 5 The three-dimensional charge distribution model shown has a×b×c contact channels. When the analog signal source contacts the charge distribution model, its contact position has a×b×c possibilities. When it contacts a certain contact channel, it first moves to the two opposite surfaces of the three-dimensional charge distribution model according to the distance, and then enters the output channels on the eight corners of the three-dimensional charge distribution model according to the contact channels on the two opposite surfaces of the three-dimensional charge distribution model to obtain the simulated output signal of the preset output channel of the positron emission tomography detector.

[0045] It should be noted that if the charge distribution model is a planar model, the output channels are not limited to 4, and can also be 1, 2, 3, or even 5, 6, etc. When the charge distribution model is a three-dimensional model, the output channels are not limited to 8, and can also be 5, 6, 7, or even 9, 10, etc., which are not limited here.

[0046] Specifically, when entering the output channel of the charge distribution model, the signal of each output channel satisfies Kirchhoff's current distribution law and Kirchhoff's voltage distribution law with the contact channel. Therefore, when outputting analog signals, the contact position of the analog signal source in the charge distribution model can be simulated by using the random number sampling method to obtain the output signals of each output channel of the charge distribution model.

[0047] In one embodiment, the total energy of the analog signal source at the contact position of the charge distribution model is equal to the sum of the energies of the signals output by each output channel.

[0048] The method for simulating and generating the output signal of the positron emission tomography detector of the present invention obtains the probability distribution function of the nuclide energy spectrum to be simulated and the signal energy value within a preset range; obtains the inverse function of the probability distribution function and the signal energy value to obtain the simulated signal source to be compressed; and uses the constraint operation rules of the output signal of the positron emission tomography detector to simulate and compress the simulated signal source to generate the output signal simulated by the preset output channel of the positron emission tomography detector. In this way, the energy spectrum is simulated and a multi-channel signal simulation source is obtained to facilitate system development and testing.

[0049] See also Figure 6 , is a schematic diagram of the structure of the first embodiment of the analog generation device for the output signal of the positron emission tomography detector of the present invention. The analog generation device for the output signal of the positron emission tomography detector includes a memory 62, a processor 63 and a digital-to-analog converter 61 which are connected to each other.

[0050] The digital to analog converter 61 (DAC) is used to convert the obtained digital signal into an analog signal and output it.

[0051] The memory 62 is used to store program instructions for implementing any one of the above-mentioned methods for simulating the generation of the output signal of the positron emission tomography detector.

[0052] The processor 63 is used to execute program instructions stored in the memory 62 .

[0053] The processor 63 may also be referred to as a CPU (Central Processing Unit). The processor 63 may be an integrated circuit chip having signal processing capabilities. The processor 63 may also be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0054] The memory 62 can be a memory stick, a TF card, etc., which can store all the information in the simulation generation device of the output signal of the positron emission tomography detector, including the input raw data, computer programs, intermediate operation results and final operation results are all stored in the memory. It stores and retrieves information according to the position specified by the controller. With the memory, the simulation generation device of the output signal of the positron emission tomography detector has a memory function to ensure normal operation. The memory in the simulation generation device of the output signal of the positron emission tomography detector can be divided into main memory (internal memory) and auxiliary memory (external memory) according to the purpose of the memory, and there is also a classification method of dividing it into external memory and internal memory. External memory is usually a magnetic medium or an optical disk, etc., which can store information for a long time. Memory refers to the storage component on the motherboard, which is used to store the data and programs currently being executed, but is only used to temporarily store programs and data. When the power is turned off or the power is cut off, the data will be lost.

[0055] In the several embodiments provided in the present application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the device implementation described above is only schematic. For example, the division of modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0056] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0057] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0058] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a system server, or a network device, etc.) or a processor to execute all or part of the steps of the various implementation methods of the present application.

[0059] See also Figure 7 , which is a schematic diagram of the structure of the storage medium of the present invention. The storage medium of the present application stores a program file 71 that can implement the simulation generation method of the output signal of all the above-mentioned positron emission tomography detectors, wherein the program file 71 can be stored in the above-mentioned storage medium in the form of a software product, including a number of instructions for a computer device (which can be a personal computer, server, or network device, etc.) or a processor (processor) to execute all or part of the steps of each implementation method of the present application. The aforementioned storage device includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program codes, or terminal devices such as computers, servers, mobile phones, tablets, etc.

[0060] The above are only implementation modes of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for simulating the output signal of a positron emission tomography detector, It is characterized in that include: Obtain the probability distribution function of the nuclide energy spectrum to be simulated and the signal energy value within a preset range; Acquire an analog signal source that needs to be compressed according to the probability distribution function and the signal energy value; The analog signal source is subjected to analog compression processing using the constraint operation rule of the output signal of the positron emission tomography detector to generate an output signal simulated by a preset output channel of the positron emission tomography detector.

2. The method according to claim 1, It is characterized in that The step of obtaining the signal source to be compressed according to the probability distribution function and the signal energy value comprises: Obtaining an inverse function of the probability distribution function; The analog signal source is calculated based on the signal energy value and the inverse function.

3. The method according to claim 1, It is characterized in that The step of performing analog compression processing on the analog signal source by using the constraint operation rule of the output signal of the positron emission tomography detector to generate an output signal simulated by a preset output channel of the positron emission tomography detector comprises: Establishing a corresponding charge distribution model according to the constraint operation rule of the output signal of the positron emission tomography detector, wherein the number of output channels of the charge distribution model is the same as the number of output channels of the positron emission tomography detector; The simulation is performed according to the contact position of the analog signal source at the charge distribution model to obtain the output signals of each output channel of the charge distribution model, thereby generating the simulated output signal of the preset output channel of the positron emission tomography detector by utilizing the output signals of each output channel of the charge distribution model.

4. The method according to claim 3, It is characterized in that The output energy of the analog signal source at the contact position is equal to the sum of the energies of the output signals of the output channels of the charge distribution model.

5. The method according to claim 4, It is characterized in that The charge distribution model is a planar charge distribution model having n×m contact channels, wherein the analog signal source is randomly contacted on any one of the n×m contact channels, and n and m are natural numbers respectively.

6. The method according to claim 4, It is characterized in that The charge distribution model is a three-dimensional charge distribution model, which has a×b×c contact channels, wherein the analog signal source randomly contacts any of the a×b×c contact channels, and a, b and c are natural numbers respectively.

7. The method according to claim 4, It is characterized in that The distribution of the total charge of the analog signal source to the output channel satisfies the basic Kirchhoff's current law and Kirchhoff's voltage law.

8. The method according to claim 3, It is characterized in that The step of performing simulation according to the contact position of the analog signal source at the charge distribution model to obtain output signals of each output channel of the charge distribution model, thereby generating a simulated output signal of a preset output channel of the positron emission tomography detector by using the output signals of each output channel of the charge distribution model, comprises: The contact position of the analog signal source on the charge distribution model is simulated by using a uniform function random number sampling method to obtain output signals of each output channel of the charge distribution model.

9. A device for simulating and generating an output signal of a positron emission tomography detector, It is characterized in that The device comprises: a processor, a memory and a digital-to-analog converter which are coupled to each other, wherein: The memory is used to store program instructions for implementing the method for simulating the output signal of the positron emission tomography detector according to any one of claims 1 to 8; The processor is used to execute the program instructions stored in the memory; The digital-to-analog converter is used to convert the obtained digital signal into an analog signal and output the analog signal.

10. A storage medium, It is characterized in that A program file is stored, and the program file can be executed to implement the method for simulating and generating the output signal of the positron emission tomography detector according to any one of claims 1 to 8.

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