High-speed data acquisition method based on single ion signal
By using single-ion signal characteristics to identify and extract effective signals when collecting electronic signals at high speed, post-processing is performed to remove noise, the problems of excessive data volume and noise accumulation are solved, and data compression and signal-to-noise ratio improvement are achieved.
Patent Information
- Application Number
- CN202311472398.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-11-07
- Publication Date
- 2025-05-09
AI Technical Summary
When collecting electronic signals at high speed, the original data volume is too large to be effectively uploaded and processed, and conventional hardware accumulation methods will lead to the accumulation of noise signals, affecting signal characteristics.
A high-speed data acquisition method based on single ion signals is adopted, and a single ion signal is identified by setting thresholds, an effective signal is extracted and recorded, and post-processed to remove noise and improve signal-to-noise ratio.
Effectively compress the data volume, retain useful single-ion signals, improve signal-to-noise ratio, reduce acquisition costs, simplify acquisition systems, and improve reliability.
Smart Images
Figure CN119965074A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of signal acquisition, and in particular to a high-speed data acquisition method based on single ion signals. Background Art
[0002] In electronic detectors such as MCP (microchannel plate), PMT (photomultiplier tube) and radar signals, the signal width is in the nanosecond level, or even in the picosecond level, so a large amount of data is often generated. Some of the data based on time-of-flight mass spectrometry and radar are periodic signals. In the case of these weak electrical signals, the conventional method is to use periodic accumulation to enhance the signal and thus increase the reliability of the signal. Because the amount of data in these signals is too large, the signals often need to be accumulated by hardware to reduce the difficulty of transmitting them to computers for processing. However, such accumulation may cause electrical noise and other noise signals that are different from the signal to be accumulated, affecting the characteristics of the signal.
[0003] The main difficulty faced by this design is that effective signals need to be collected at high speed, because only a high sampling rate can obtain the complete signal of such fast electrons; at the same time, the amount of useful information is not large, that is, there are only sporadic effective single ion peak data in a large amount of data, especially when measuring trace substances, the effective data is less than 1% of the data collected. The current solution cannot restore each effective data and cannot post-process the original data.
[0004] Therefore, based on the above-mentioned defects of the prior art, the present invention provides a data acquisition algorithm based on single ion signals. The data obtained by this design method can be subjected to a corresponding post-processing algorithm, that is, it is applied to the scenario of weak electric signals, and the remaining noise signals are eliminated by conventional identification of single ions, and only the original data of the valid signal is transmitted and saved; then, on this basis, the original signal is processed separately and pre-periodically accumulated, and then the original signal is compared with the accumulated effect to screen out the chemical noise before accumulation. Summary of the invention
[0005] In view of the above-mentioned deficiencies in the prior art, the present invention aims to provide a high-speed data acquisition method based on single ion signals, which solves the problem that the amount of raw data is too large to be uploaded during high-speed acquisition.
[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions: The present invention provides a high-speed data acquisition method based on a single ion signal, and the method is as follows: taking the single ion signal feature as the hardware processing standard after high-speed acquisition, setting a threshold as a benchmark, when the signal crosses the threshold from positive to negative, until the signal exceeds the threshold in the positive direction, it indicates that the segment is a single ion signal, extracting and recording the segment of the single ion signal and its starting point position, repeating the above-mentioned method of recording data, recording data until the preset acquisition length after the trigger signal for starting the acquisition is completed, that is, during the acquisition process, recording several groups of data within the trigger length of this time; after completing one-time triggered acquisition, encapsulating the data of this single trigger in a fixed format; and then uploading to a computer in the trigger interval, and the computer reversely parses according to the above-mentioned format to restore all the original signals of one trigger.
[0007] Preferably, a high-speed data acquisition algorithm based on single ion signals is provided for the above data acquisition method, and the algorithm steps are as follows: S1, for the selected original single ion signal, when recording, perform back-tracking judgment on it and remove the electrical noise, that is, remove the electrical noise of the selected original single ion signal when recording; among them, the peak with a non-negative start point and the smaller ringing signal in a fixed time after the peak are all electrical noise (depending on whether the starting signal is higher than another higher threshold, it is judged whether the starting direction of the signal peak is downward. If not, the peak with a non-negative start point can be removed; and the smaller ringing signal in a fixed time after the peak can be removed); S2, using Gaussian fitting, calculate the highest point of each single ion peak in the original single ion signal in S1; S3, after calibrating the working curve with different sample concentrations for different signal intensities, the fixed peak single ion peak height is refitted for the intensities that are not single ion peaks (i.e., one ion or two ions, the fixed intensity is redefined according to the original signal range), which is beneficial for subsequent quantification; S4, using Gaussian signal algorithm to restore the saturated signal; S5, using time-of-flight mass spectrometry to perform pre-accumulation of the reduction signal several times, and treating the occasional stray ions in the pre-accumulation as chemical noise, deducting the position signal from the original signal and then accumulating it again, so that the signal-to-noise ratio of the given signal is improved; S6, after pre-accumulating the original signal, the hardware resolution of the mass spectrometer is calculated using the time-of-flight mass spectrometer, and based on the resolution, the ion signals within the half-peak width of the corresponding mass segment are normalized to the corresponding pre-accumulated peak position, so that the resolution of the instrument is improved.
[0008] The beneficial effects of the present invention are as follows: the present invention utilizes conventional identification of single ions (small signal units acquired in a single time) to eliminate the remaining noise signals, and transmits and stores only the original signals of valid signals, thereby obtaining a small amount of useful data, retaining useful single ion signals, compressing data, and improving the signal-to-noise ratio, thereby solving the problem that the amount of original data is too large to be uploaded during high-speed acquisition; on this basis, the original signal is processed separately and pre-periodically accumulated, and then the original signal and the accumulated effect are compared and screened before being accumulated, and the slight position difference of the signal is re-corrected based on the overall performance of the time-of-flight mass spectrometer, thereby improving the instrument resolution; at the same time, no hardware accumulation and other functions are required, thereby reducing the cost of high-speed acquisition, simplifying the acquisition system, and improving the reliability of the relevant acquisition system. BRIEF DESCRIPTION OF THE DRAWINGS
[0009] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0010] Figure 1 The collected original single ion signal provided by the embodiment of the present invention; Figure 2 For Figure 1 After Gaussian fitting, restore the highest point; Figure 3 For Figure 2 The highest point position is replaced by Gaussian or other regular signal; Figure 4 For the general Figure 3 Comparison of the spectrum information obtained by accumulating the converted multiple ion peaks using the time-of-flight mass spectrometer principle and the direct accumulation of the original signals; Figure 5 Schematic diagram of signal intensity normalization, where (a) is a schematic diagram of the original signal, and (b) is a schematic diagram of the ion signal intensity obtained based on the working curve (in Figure 5 It should be noted that each single ion peak has different intensities and the ion signal does not change linearly. Therefore, the signal intensity is normalized according to the intensity of one, two, or three ion signals); Figure 6 Schematic diagram of the processing process for saturated signals. Figure (a) is the original saturated signal, and Figure (b) is the original signal restored by peak shape fitting and Figure 3 After single ion peak processing, Figure (c) shows the original saturated signal and the original signal after fitting and restoration. Figure 3 Comparison of treatment methods; Figure 7 Schematic diagram of identifying the electrical noise characteristics of ringing, where (a) is a signal diagram that has not been identified by the ringing characteristics. According to the signal line, the next small signal is calculated to be the ringing on the oscillation period, and (b) is a single ion peak after removing the electrical noise; Figure 8 The peak shape of the accumulated spectrum after the mass axis is normalized for the single ion peak of the original signal according to the instrument resolution; Fig. 9 Schematic diagram of the TDC-like (non-binary time-to-digital conversion acquisition) processing process based on the signal after ion number correction, including the original signal diagram of multiple triggering at the same position (a), the TDC-like conversion diagram of the original signal (b), and the acquisition method using a TDC-like method to accumulate and obtain the optimized sample information spectrum (c). DETAILED DESCRIPTION
[0011] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0012] In addition, it should be noted that the method of the present invention is aimed at the collection of electronic signals generated by electron multiplication, and can be analogized to other high-speed acquisition signals with similar rules. The millions of electrons generated by electron multiplication will produce a high-speed spike from the signal ground to the negative signal. The threshold is taken into account that there will be a base for noise, and the effective signal is a threshold below this base.
[0013] Embodiment, a high-speed data acquisition method based on single ion signal, the method is as follows: using the single ion signal feature as the hardware processing standard after high-speed acquisition, setting a threshold as a reference, when the signal crosses the threshold from positive to negative, until the signal exceeds the threshold in the positive direction, it indicates that the segment is a single ion signal, extract and record the segment of the single ion signal and its starting point, repeat the above-mentioned method of recording data, record the data until the preset acquisition length after the trigger signal for starting the acquisition is completed, that is, during the acquisition process, record several groups of data within the trigger length of this time; after one trigger acquisition is completed, encapsulate the data of this trigger in a fixed format; and then upload it to the computer in the trigger interval, and the computer reversely analyzes it in the above-mentioned format to restore all the original signals of one trigger. Among them, it should be noted that the above-mentioned single ion signal feature is the feature of an effective signal acquired at high speed with electron multiplication as the carrier, and the few effective signals that can be summarized in the high-speed acquisition can be processed by this method.
[0014] Furthermore, a high-speed data acquisition algorithm based on single ion signals is provided for the above data acquisition method, and the algorithm steps are as follows: S1, for the selected original single ion signal, when recording, perform back-tracking judgment on it and remove the electrical noise, that is, remove the electrical noise of the selected original single ion signal when recording; among them, the peak with a non-negative start point and the smaller ringing signal in a fixed time after the peak are all electrical noise (depending on whether the starting signal is higher than another higher threshold, it is judged whether the starting direction of the signal peak is downward. If not, the peak with a non-negative start point can be removed; and the smaller ringing signal in a fixed time after the peak can be removed); S2, using Gaussian fitting, calculate the highest point of each single ion peak in the original single ion signal in S1; S3, after calibrating the working curve with different sample concentrations for different signal intensities, the fixed peak single ion peak height is refitted for the intensities that are not single ion peaks (i.e., one ion or two ions, the fixed intensity is redefined according to the original signal range), which is beneficial for subsequent quantification; S4, using Gaussian signal algorithm to restore the saturated signal; S5, using a time-of-flight mass spectrometer to perform multiple pre-accumulation of the reduction signal, and treating the occasional stray ions in the pre-accumulation as chemical noise, deducting the position signal from the original signal and then accumulating it, so that the signal-to-noise ratio of the given signal is improved. It should be noted that according to the theory of the time-of-flight analyzer, no random ions on the mass axis will appear; S6, after pre-accumulating the original signal, the hardware resolution capability of the mass spectrometer is calculated using the time-of-flight mass spectrometer, and based on the resolution capability, the ion signals within the half-peak width of the corresponding mass segment are normalized to the corresponding pre-accumulated peak position. For example, if the half-peak width of the corresponding mass segment is 2ns, the ion signals within 2ns are normalized to the corresponding pre-accumulated peak position, thereby improving the resolution capability of the instrument. It should be noted that the resolution capability is to resolve the ion signals within 2ns into ions of the same mass-to-charge ratio.
[0015] The specific operation method is as follows: Step 1: Use the single ion signal feature as the hardware processing standard after high-speed acquisition, set a threshold as the benchmark, and when the signal crosses the threshold from positive to negative, it indicates that the segment is a single ion signal; take 2-3 points before the threshold as sampling points, and observe whether the sampling points are higher than another higher threshold to determine whether there is a positive peak before the single ion signal, and if there is a positive peak before crossing the threshold, it is judged as electrical noise; Step 2, after the trigger signal starts, when the signal in step 1 exceeds the threshold in the positive direction, extract the segment signal, record the segment peak signal and its starting point, repeat the recording method, continue to record the valid signal until the preset acquisition length after the trigger signal of the start of the acquisition is completed, and then, encapsulate the data of this single trigger in a fixed format; Step 3, upload the single-trigger data in step 2 to the computer in the trigger interval, and the computer will reverse analyze it according to the above format to restore all the signals triggered once; Step 4, pre-accumulating all signals triggered by the reduction in step 3, and using a time-of-flight mass spectrometer to analyze and obtain real-time online data of single ion signals; Step 5, on the computer, fit the original signal in step 1 according to the Gaussian peak shape, restore the ideal peak of the single ion, increase the sampling rate to obtain the highest point, reduce the half-peak width of the single ion peak, and improve the resolution; then restore the sample concentration represented by the signal using the working curve method according to the signal range, whether the signal is saturated and the saturation; and because the shape of the peak will be affected by the hardware parameters, Gaussian or other regular signal replacement can be performed at the highest point of each single ion peak (such as Figure 3 (as shown in the figure) to obtain a series of perfect single ion signal peaks; in the case of pre-accumulation, the position of the single ion signal is corrected within the resolution range of the time-of-flight mass spectrometer, the position data of each single ion peak is obtained again, and the optimized sample information spectrum is obtained at the same time.
[0016] According to step 4 above, the converted multiple ion peaks are accumulated using time-of-flight mass spectrometry to obtain real-time online data of single ion signals (such as Figure 4 and Figure 5 As shown in Figure (a) and Figure (b) in Figure 4Compared with the black line shown in the figure, it can be observed that there is a significant difference in signal intensity. At this time, the signal intensity of the significant difference can be used for algorithm S3 to perform single ion and multi-ion linear correction based on the working curve of sample concentration, such as Figure 4 Then, in algorithm S4, according to the saturation degree of the saturated signal (such as Figure 6 As shown in Figures (a), (b), and (c), for example, the number of saturation points is used to restore the saturated signal. It should be noted that Figure 6 In the saturated signal line graph shown in (c), ringing will appear next to it. At this time, the signal is identified based on the ringing feature, and the signal that is not identified by the ringing feature is the signal (such as Figure 7 The next small signal is calculated as the ringing on the oscillation period according to the signal line, and the electrical noise is removed to obtain the single ion peak (as shown in Figure a). Figure 7 (as shown in Figure b); Since the reduction signal is pre-accumulated multiple times using the time-of-flight mass spectrometer, and stray ions occasionally appear during the pre-accumulation, according to algorithm S4, the stray ions can be treated as chemical noise to improve the signal-to-noise ratio; after the chemical noise treatment, recalibration is performed, that is, algorithm S6 is performed to pre-accumulate the reduction signal, and after the pre-accumulation, the mass axis of the single ion peak is recalibrated (such as Figure 8 As shown); based on the signal corrected by the number of ions, a time-to-digital conversion acquisition TDC can be performed (as shown Fig. 9 As shown in Figures a and b), the signal is accumulated in a TDC-like manner to obtain the optimized sample information spectrum (as shown in Figures a and b). Fig. 9 (as shown in Figure c).
[0017] The data acquisition method and algorithm based on single ion signals in the present invention collect single ion signals amplified by electron multiplication at high speed, perform comprehensive processing of threshold baseline on the collected data according to the characteristics of single ion signals, and add position information at the same time, so as to obtain a small amount of useful data, retain useful single ion signals, compress data, and improve signal-to-noise ratio at the same time; transmit the data to a computer, and the computer has more resources to restore the above signals faster and perform post-processing, which is fast, reliable and efficient; by being able to obtain the original signal based on the single ion, the original signal can be subjected to ringing discrimination, random noise discrimination after pre-accumulation, and even chemical noise discrimination; the single ion signal can be corrected using an ideal Gaussian distribution; multiple ions can be judged and distinguished based on obvious differences in signal intensity, whether they are saturated or not, and the degree of saturation, so that the nonlinearity between multiple ions and a single ion can be restored, and the original signal of the saturated signal can be reshaped; at the same time, pre-accumulation and other processing can be performed, and the slight position difference of the signal can be re-corrected based on the performance of the entire instrument to improve the resolution of the instrument.
[0018] In addition, the acquisition method described in the present invention is suitable for high-speed acquisition with few effective signals and characteristic signals that can be summarized; for the effective signal characteristics, only the processing method corresponding to the characteristic can be used to obtain the acquisition of effective signals using the acquisition method corresponding to the present invention, and the response signal can be processed using the post-processing method corresponding to the present invention. After the original signal is obtained, more post-processing methods can be expanded under the post-processing scheme corresponding to the present invention. Moreover, the post-processing method of the present invention is not limited to the data obtained by the acquisition method, as long as the data of the original signal is obtained, it can be processed by the post-processing method of the present invention.
[0019] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.
Claims
1. A high-speed data acquisition method based on single ion signals, the method is as follows: using the single ion signal characteristics as the hardware processing standard for high-speed acquisition, setting a threshold as a benchmark, when the signal crosses the threshold from positive to negative, until the signal exceeds the threshold in the positive direction, it indicates that the segment is a single ion signal, extract and record the segment of the single ion signal and its starting point, repeat the above data recording method, record the data until the preset acquisition length after the trigger signal for starting the acquisition is completed, that is, during the acquisition process, record several groups of data within the trigger length of this time; after a triggered acquisition is completed, encapsulate the data of this single trigger in a fixed format; and then upload it to the computer in the trigger gap, and the computer reversely parses it in the above format to restore all the original signals of a single trigger.
2. A high-speed data acquisition method based on single ion signals according to claim 1, characterized in that; A high-speed data acquisition algorithm based on single ion signals is provided for the above data acquisition method, and the algorithm comprises the following steps: S1, for the selected original single ion signal, when recording, perform back-tracking judgment on it and remove the electrical noise, that is, remove the electrical noise of the selected original single ion signal when recording, among which the non-negative peak at the starting point and the small ringing signal in a fixed time after the peak are all electrical noise; S2, using Gaussian fitting, calculate the highest point of each single ion peak in the original single ion signal in S1; S3, after calibrating the working curve with different sample concentrations for different signal intensities, the fixed peak single ion peak height is refitted for the intensities that are not single ion peaks, which is beneficial for subsequent quantification; S4, using Gaussian signal algorithm to restore the saturated signal; S5, using time-of-flight mass spectrometry to perform pre-accumulation of the reduction signal several times, and treating the occasional stray ions in the pre-accumulation as chemical noise, deducting the position signal from the original signal and then accumulating it again, so that the signal-to-noise ratio of the given signal is improved; S6, after pre-accumulating the original signal, the hardware resolution of the mass spectrometer is calculated using the time-of-flight mass spectrometer, and based on the resolution, the ion signals within the half-peak width of the corresponding mass segment are normalized to the corresponding pre-accumulated peak position, so that the resolution of the instrument is improved.