Signal acquisition apparatus and method

Abstract

The application relates to the medical technology field and provides a signal acquisition device and method. The device comprises a signal acquisition module, which is used for acquiring a first ECG signal and a first gradient pulse interference signal generated in a scanning process; and a signal processing module, which stores an electromagnetic interference signal correction coefficient and is used for correcting the amplitude of the first gradient pulse interference signal based on the electromagnetic interference signal correction coefficient, and then filtering out the electromagnetic interference signal in the first ECG signal based on the first gradient pulse interference signal after the amplitude correction, so as to obtain a target ECG signal. The application can reduce the loss or distortion of the ECG signal and improve the cardiac scanning image quality of a magnetic resonance imaging system.

Description

Technical Field

[0001] This application relates to the field of medical technology, and in particular to a signal acquisition device and method. Background Technology

[0002] Magnetic resonance imaging (MRI) is a medical imaging method based on the nuclear magnetic resonance phenomenon. It is one of the modern large-scale medical imaging diagnostic devices, characterized by no electromagnetic radiation, high contrast, multiple parameters, and imaging in any orientation. It has an increasingly wide range of applications in modern clinical medical diagnosis.

[0003] When performing magnetic resonance imaging (MRI) scans on the chest and abdomen, physiological movements such as heartbeats and respiration cause the actual imaging data of the resonance tomography obtained within each repetition time (TR) to differ from the expected results described by the sequence. This results in motion artifacts in the reconstructed imaging data of these areas, affecting the quality of MRI images and clinical diagnostic applications.

[0004] Currently, motion synchronization techniques for obtaining motion artifact-free MRI images of the chest and abdomen include prospective gating and retrospective gating. Regardless of the gating technique used, the MRI system requires a gating acquisition and processing unit within the MRI scan bay for acquiring and processing physiological gating signals such as ECG (Electrocardiogram), Resp (Respiratory) signals, or PPG (Photoplethysmography) signals.

[0005] When acquiring ECG signals, electromagnetic interference signals can be transmitted to the ECG signal acquisition circuit due to the presence of unshielded electrode leads. Since the electromagnetic interference signals include gradient pulse interference signals, the frequency of which overlaps with the ECG signal, causing the ECG signal to be lost or distorted. Summary of the Invention

[0006] In view of this, this application provides a signal acquisition device and method that solves the problem of eliminating pulse interference in ECG signals.

[0007] In a first aspect, embodiments of this application provide a signal acquisition device, comprising: a signal acquisition module for acquiring a first ECG signal and acquiring a first gradient pulse interference signal generated during scanning; and a signal processing module for storing electromagnetic interference signal correction coefficients, for performing amplitude correction on the first gradient pulse interference signal based on the electromagnetic interference signal correction coefficients, and then filtering out the electromagnetic interference signal in the first ECG signal based on the amplitude-corrected first gradient pulse interference signal to obtain a target ECG signal.

[0008] The signal acquisition device according to the embodiments of this application may also have the following additional technical features:

[0009] In the above technical solution, optionally, the signal acquisition module includes:

[0010] The ECG signal acquisition module is used to acquire the primary ECG analog signal, and after preprocessing the primary ECG analog signal, perform analog-to-digital conversion to generate the first ECG signal.

[0011] The electromagnetic interference signal acquisition module is used to acquire electromagnetic interference analog signals, and after preprocessing the electromagnetic interference analog signals, perform analog-to-digital conversion to generate the first gradient pulse interference signal.

[0012] In any of the above technical solutions, optionally, the electromagnetic interference signal acquisition module includes:

[0013] Signal acquisition antenna, used to acquire simulated electromagnetic interference signals;

[0014] The first filtering module is connected to the signal acquisition antenna and is used to perform low-pass filtering on the electromagnetic interference analog signal to filter out the radio frequency pulse interference frequency component in the electromagnetic interference analog signal and obtain the gradient pulse interference analog signal.

[0015] The first amplification module, connected to the first filtering module, is used to amplify the gradient pulse interference analog signal.

[0016] The first analog-to-digital converter is connected to the first amplification module and is used to perform analog-to-digital conversion on the amplified gradient pulse interference signal to generate the first gradient pulse interference signal.

[0017] Optionally, in any of the above technical solutions, the ECG signal acquisition module includes:

[0018] The signal acquisition interface connects to the leads of the ECG electrode and is used to acquire primary ECG analog signals.

[0019] The second filtering module is connected to the signal acquisition interface and is used to perform low-pass filtering on the primary ECG analog signal to filter out the radio frequency pulse interference frequency components in the primary ECG analog signal and generate the secondary ECG analog signal.

[0020] The second amplification module, connected to the second filtering module, is used to amplify the secondary ECG analog signal.

[0021] The second analog-to-digital converter, connected to the second amplification module, is used to perform analog-to-digital conversion on the amplified secondary ECG analog signal to generate the first ECG signal.

[0022] In any of the above technical solutions, optionally, the electromagnetic interference signal correction coefficient is obtained by calculating the ratio of the maximum amplitude of the second ECG signal to the maximum amplitude of the second gradient pulse interference signal in each preset time period after acquiring the second ECG signal and the second gradient pulse interference signal in n preset time periods, and then averaging the ratios in the n preset time periods, where n is an integer greater than or equal to 2.

[0023] The signal processing module is specifically used to multiply the first gradient pulse interference signal with the electromagnetic interference signal correction coefficient to obtain the amplitude-corrected first gradient pulse interference signal, and to subtract the first ECG signal from the amplitude-corrected first gradient pulse interference signal to obtain the target ECG signal.

[0024] Optionally, in any of the above technical solutions, the signal acquisition device further includes a shielding shell, with the first and second filtering modules, the first and second amplification modules, the first and second analog-to-digital converters, and the signal processing module disposed inside the shielding shell, and the signal acquisition part of the signal acquisition antenna disposed outside the shielding shell.

[0025] Secondly, embodiments of this application provide a signal acquisition method, including:

[0026] Acquire the first ECG signal and the first gradient pulse interference signal generated during the scanning process;

[0027] Amplitude correction of the first gradient pulse interference signal is performed based on the electromagnetic interference signal correction coefficient.

[0028] Based on the amplitude-corrected first gradient pulse interference signal, the electromagnetic interference signal in the first ECG signal is filtered out to obtain the target ECG signal.

[0029] The signal acquisition method described above according to the embodiments of this application may also have the following additional technical features:

[0030] Optionally, in the above technical solution, acquiring the first ECG signal and the first gradient pulse interference signal generated during the scanning process includes:

[0031] The primary ECG analog signal is acquired, and after low-pass filtering and amplification, it is converted from analog to digital to generate the first ECG signal.

[0032] The electromagnetic interference simulation signal is acquired, and after low-pass filtering and amplification, it is converted from analog to digital to generate the first gradient pulse interference signal.

[0033] In any of the above technical solutions, optionally, the electromagnetic interference signal correction coefficient is obtained by calculating the ratio of the maximum amplitude of the second ECG signal to the maximum amplitude of the second gradient pulse interference signal in each preset time period after acquiring the second ECG signal and the second gradient pulse interference signal in n preset time periods, and then averaging the ratios in the n preset time periods, where n is an integer greater than or equal to 2.

[0034] Amplitude correction of the first gradient pulse interference signal based on electromagnetic interference signal correction coefficients includes:

[0035] The first gradient pulse interference signal is multiplied by the electromagnetic interference signal correction coefficient to obtain the amplitude-corrected first gradient pulse interference signal.

[0036] Based on the amplitude-corrected first gradient pulse interference signal, electromagnetic interference signals within the first ECG signal are filtered out to obtain the target ECG signal, including:

[0037] The target ECG signal is obtained by subtracting the first ECG signal from the amplitude-corrected first gradient pulse interference signal.

[0038] In any of the above technical solutions, optionally, before performing amplitude correction on the first gradient pulse interference signal based on the electromagnetic interference signal correction coefficient, the method further includes:

[0039] Acquire the second ECG signal and the second gradient pulse interference signal for n preset time periods, and determine the maximum amplitude of the second ECG signal and the maximum amplitude of the second gradient pulse interference signal within each preset time period, where n is an integer greater than or equal to 2;

[0040] Calculate the ratio of the maximum amplitude of the second ECG signal to the maximum amplitude of the second gradient pulse interference signal within each preset time period, and calculate the average value of the ratios over n preset time periods. Store the average value as an electromagnetic interference signal correction coefficient.

[0041] In this embodiment, a signal acquisition module acquires a first ECG signal and a first gradient pulse interference signal between the scanning of the magnetic resonance imaging system. After the signal processing module performs amplitude correction on the acquired first gradient pulse interference signal, it filters out the electromagnetic interference introduced when the first ECG signal is received based on the amplitude-corrected first gradient pulse interference signal, thereby reducing the loss or distortion of the ECG signal and improving the quality of the cardiac scan image of the magnetic resonance imaging system.

[0042] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0043] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0044] Figure 1 A structural block diagram of a signal acquisition device according to an embodiment of this application is shown;

[0045] Figure 2 A structural block diagram of the ECG gating signal acquisition board according to an embodiment of this application is shown;

[0046] Figure 3 A flowchart illustrating the amplitude correction processing algorithm of an embodiment of this application is shown;

[0047] Figure 4 A schematic flowchart of a signal acquisition method according to an embodiment of this application is shown. Detailed Implementation

[0048] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.

[0049] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0050] To obtain stable MRI images of the heart or abdomen, in addition to ensuring that the patient remains still during the scan, motion synchronization technology is needed to process periodic physiological movements such as heartbeat and respiration. This ensures that the data of each TR filled in the same K-space comes from the resonance tomography of the same physiological site, thereby reducing motion artifacts.

[0051] Currently, motion synchronization techniques for obtaining motion artifact-free magnetic resonance imaging (MRI) images of the chest and abdomen include prospective gating and retrospective gating. Prospective gating involves first detecting cardiac cycle or respiratory motion changes in the MRI system. When data acquisition requirements are met (e.g., during diastole or a respiratory plateau), sequential scanning is initiated, RF pulses are emitted, and signals are acquired. Retrospective gating, on the other hand, continuously scans and acquires data throughout the entire cardiac cycle or respiratory motion. A gating device detects the phase of cardiac and respiratory movements. After the scan, images with approximately the same phase are reconstructed and combined to create images of different cardiac or respiratory phases.

[0052] Regardless of the gating technology used, the magnetic resonance imaging system needs to be equipped with a gating acquisition and processing device in the magnetic resonance scanning room for the acquisition and processing of physiological gating signals such as ECG, Resp, or PPG signals.

[0053] However, during the scanning process of a magnetic resonance imaging (MRI) system, in order to achieve spatial positioning of the scanned slices, high-power gradient pulses need to be applied to the gradient coils, causing the gradient coils to generate a pulsed gradient field. This results in electromagnetic interference from the gradient pulses during the scan. To excite the selected slices, the radio frequency (RF) transmission link generates an RF signal at the transmitting coil end. Therefore, the MRI scan room is filled with electromagnetic wave signals during the system scan. For ECG signal acquisition, due to the presence of unshielded electrode leads, high-power gradient pulse RF interference can be transmitted into the ECG signal acquisition circuit. The weak ECG signal is often overwhelmed by this RF interference signal, and the frequency of the gradient pulse interference signal included in this RF interference signal overlaps with the frequency band of the physiological gating signal. Therefore, the method of filtering the interfering electromagnetic waves using low-frequency filters in related technologies does not achieve the desired effect.

[0054] This application provides a solution to improve the anti-interference of ECG signals in a magnetic resonance imaging system, eliminating electromagnetic interference signals introduced by ECG electrode leads and ensuring the quality of cardiac scan images in the magnetic resonance imaging system under ECG gating.

[0055] The signal acquisition device, signal acquisition method, computer equipment, and readable storage medium provided in this application will be described in detail below with reference to the accompanying drawings and through specific embodiments and application scenarios.

[0056] This application provides a signal acquisition device, such as... Figure 1 and Figure 2 As shown, the signal acquisition device includes an ECG gated signal acquisition unit and a gated signal receiving unit. The ECG gated signal acquisition unit is typically placed on the patient's bed, and the gated signal receiving unit is typically mounted inside the magnetic resonance imaging (MRI) chamber. The ECG gated signal acquisition unit includes an ECG gated signal acquisition board and an EMC (Electromagnetic Compatibility) shielding shell. The EMC shielding shell covers the electrical components of the ECG gated signal acquisition board, except for the antenna with acquisition and reception functions, to reduce electromagnetic interference to the shielded part. The gated signal receiving unit is used to transmit the output signal of the ECG gated signal acquisition unit to the MRI scan control unit.

[0057] The ECG gating signal acquisition board is equipped with a signal acquisition module and a signal processing module. The signal acquisition module is used to acquire the first ECG signal and the first gradient pulse interference signal generated during the scanning process. The signal processing module stores electromagnetic interference signal correction coefficients and is used to perform amplitude correction on the first gradient pulse interference signal based on the electromagnetic interference signal correction coefficients. Then, based on the amplitude-corrected first gradient pulse interference signal, the electromagnetic interference signal in the first ECG signal is filtered out to obtain the target ECG signal.

[0058] In this embodiment, the signal acquisition module acquires the first ECG signal and the first gradient pulse interference signal between the magnetic resonance imaging system scan. The signal processing module corrects the amplitude of the first gradient pulse interference signal using an electromagnetic interference signal correction coefficient. Based on the amplitude-corrected first gradient pulse interference signal, the electromagnetic interference introduced into the first ECG signal is filtered out, reducing the loss or distortion of the ECG signal and improving the quality of the cardiac scan image of the magnetic resonance imaging system.

[0059] In one embodiment of this application, the signal acquisition module includes an ECG signal acquisition module and an electromagnetic interference signal acquisition module. The ECG signal acquisition module acquires a primary ECG analog signal, preprocesses the primary ECG analog signal, and then performs analog-to-digital conversion to generate a first ECG signal. The electromagnetic interference signal acquisition module acquires an electromagnetic interference analog signal, preprocesses the electromagnetic interference analog signal, and then performs analog-to-digital conversion to generate a first gradient pulse interference signal.

[0060] As can be seen from the signal acquisition and processing process of this application embodiment, both the first ECG signal and the first gradient pulse interference signal are digital signals, and the signal processing module further processes the digital signals. The electromagnetic interference simulation signal includes a radio frequency pulse interference simulation signal and a gradient pulse interference simulation signal. The primary ECG simulation signal includes an ECG simulation signal, a radio frequency pulse interference simulation signal, and a gradient pulse interference simulation signal. The radio frequency pulse interference simulation signal is mainly located in the high-frequency portion of the electromagnetic interference simulation signal and the primary ECG simulation signal, while the gradient pulse interference simulation signal overlaps with the ECG simulation signal in frequency. The preprocessing of the electromagnetic interference simulation signal and the initial ECG simulation signal includes filtering out the radio frequency pulse interference simulation signal.

[0061] In one embodiment of this application, such as Figure 2 As shown, the electromagnetic interference signal acquisition module includes a signal acquisition antenna, a first filtering module, a first amplification module, and a first analog-to-digital converter (ADC). The signal acquisition antenna is used to acquire simulated electromagnetic interference signals. The first filtering module, connected to the signal acquisition antenna, performs low-pass filtering on the simulated electromagnetic interference signals to remove radio frequency pulse interference frequency components, obtaining a gradient pulse interference simulated signal. The first amplification module, connected to the first filtering module, amplifies the gradient pulse interference simulated signal. The first ADC, connected to the first amplification module, performs analog-to-digital conversion on the amplified gradient pulse interference signal to generate a first gradient pulse interference signal. In this embodiment, the preprocessing of the simulated electromagnetic interference signal includes low-pass filtering and amplification. The low-pass filtering is mainly used to filter out the radio frequency pulse interference simulated signal. The amplification mainly enables the gradient pulse interference simulated signal to pass through the linear processing range of the first ADC, improving the processing efficiency and accuracy of the first ADC. In one example, the first amplification module and the first ADC can be integrated together. In another example, the first filtering module and the first amplification module are integrated together to form a first signal conditioning module. The signal acquisition antenna can be a PCB board basewire antenna of the ECG gated signal acquisition board, or an independent receiving antenna or pickup coil assembled inside the ECG gated signal acquisition unit. It can also be replaced by an external antenna or pickup coil of the ECG gated signal acquisition unit, and the external antenna or pickup coil can be placed inside the magnet cavity or in the unshielded area of ​​the patient bed.

[0062] In one embodiment of this application, such as Figure 2As shown, the ECG signal acquisition module includes a signal acquisition interface, a second filtering module, a second amplification module, and a second analog-to-digital converter. The signal acquisition interface, connected to the leads of the ECG electrodes, is used to acquire the primary ECG analog signal. The second filtering module, connected to the signal acquisition interface, performs low-pass filtering on the primary ECG analog signal to remove radio frequency pulse interference components, generating a secondary ECG analog signal. The second amplification module, connected to the second filtering module, amplifies the secondary ECG analog signal. The second analog-to-digital converter, connected to the second amplification module, performs analog-to-digital conversion on the amplified secondary ECG analog signal to generate a first ECG signal.

[0063] In this embodiment, the preprocessing of the primary ECG analog signal includes low-pass filtering and amplification. Low-pass filtering primarily filters out radio frequency pulse interference analog signals. Amplification mainly improves the linear processing range of the first analog-to-digital converter (ADC) by reducing the gradient pulse interference analog signal, thereby enhancing the processing efficiency and accuracy of the second ADC. In one example, the second amplification module and the second ADC can be integrated. In another example, the second filtering module and the second amplification module are integrated to form a second signal conditioning module.

[0064] It is worth noting that the physiological gating signals in related technologies rely solely on shielding the device and filtering the signal to achieve anti-interference. However, due to the presence of the ECG electrode leads, electromagnetic interference signals are introduced into the ECG acquisition link. Furthermore, the gradient pulse interference signals included in the electromagnetic interference signals overlap with the ECG signals in frequency range, making it impossible to completely filter out the gradient pulse interference using filters, thus failing to achieve a good filtering effect.

[0065] The embodiments of this application can eliminate gradient pulse interference signals introduced by ECG electrode leads, thereby improving the quality of cardiac scan images in magnetic resonance imaging systems.

[0066] It should be noted that, except for the signal acquisition antenna, all other areas on the ECG gated signal acquisition board are housed within the EMC shielding enclosure. In other words, the first and second filtering modules, the first and second amplification modules, the first and second analog-to-digital converters, and the signal processing module are located inside the shielding enclosure, while the signal acquisition portion of the signal acquisition antenna is located outside the shielding enclosure.

[0067] In one embodiment of this application, such as Figure 2 As shown, the ECG signal acquisition module also includes an electrostatic discharge (ESD) protection module, which is located between the signal acquisition interface and the second filtering module.

[0068] Electromagnetic interference generated during the scanning process is transmitted through a signal acquisition antenna to generate a simulated electromagnetic interference signal, which is then input to the first signal conditioning module. The first filtering module in the first signal conditioning module filters out radio frequency components from the simulated electromagnetic interference signal, obtaining a gradient pulse interference simulated signal. The first amplification module in the first signal conditioning module pre-amplifies the gradient pulse interference simulated signal. In the first analog-to-digital converter, the gradient pulse interference simulated signal is converted into a first gradient pulse interference signal, i.e., the first gradient pulse interference signal is a digital signal, and the output first gradient pulse interference signal is input to the signal processing module.

[0069] The initial ECG analog signal, transmitted via the ECG electrode leads, is input to the second signal conditioning module via the ESD protection module. The second filtering module in the second signal conditioning module filters out radio frequency components from the initial ECG analog signal, generating a secondary ECG analog signal. The second amplification module in the second signal conditioning module pre-amplifies the secondary ECG analog signal. In the second analog-to-digital converter, the primary ECG analog signal is converted into a first ECG signal, i.e., the first ECG signal is a digital signal. The output first ECG signal is input to the signal processing module.

[0070] During the system calibration phase after installation or during routine scanning, the signal processing module simultaneously reads the digitized second ECG signal SE(t) and the digitized second gradient pulse interference signal SN(t), and employs... Figure 3 The amplitude correction processing algorithm shown performs amplitude matching operations on the second ECG signal SE(t) and the second gradient pulse interference signal SN(t). Specifically, the calibration loop count n is set; the first analog-to-digital converter and the second analog-to-digital converter are reset; the second ECG signal SE(t) and the second gradient pulse interference signal SN(t) are read for n TR time periods; the maximum value SE_max of the second ECG signal SE(t) and the maximum amplitude SN_max of the second gradient pulse interference signal SN(t) are found in each TR time period, and the ratio parameter μ(i) of the maximum value SE_max of the second ECG signal SE(t) and the maximum amplitude SN_max of the second gradient pulse interference signal SN(t) in each TR time period is calculated, i = 1…n; finally, the average ratio parameter μ of the maximum value SE_max of the second ECG signal SE(t) and the maximum amplitude SN_max of the second gradient pulse interference signal SN(t) over n TR time periods is calculated, and the obtained average ratio parameter μ is stored in memory as an electromagnetic interference signal correction coefficient.

[0071] During routine clinical scanning or the scanning process after sequence calibration, the signal processing module reads the electromagnetic interference signal correction coefficient μ from the memory and simultaneously reads the first ECG signal SE(t)' and the first gradient pulse interference signal SN(t)' frame by frame. In each frame, the first ECG signal SE(t)' is subtracted from the first gradient pulse interference signal SN(t)' multiplied by the electromagnetic interference signal correction coefficient μ, yielding the result SE_denoise, i.e., SE_denoise = SE(t)' - SN(t)' × μ. The subtraction result SE_denoise is used as the target ECG signal with electromagnetic noise removed. Finally, the obtained target ECG signal with electromagnetic noise removed is transmitted to the gated signal receiving unit via the wireless transceiver module.

[0072] In this embodiment, a signal acquisition antenna collects the first gradient pulse interference signal generated during magnetic resonance scanning. An electromagnetic interference signal correction coefficient is used to correct the amplitude of the first gradient pulse interference signal, making the maximum amplitude of the first gradient pulse interference signal nearly identical to the maximum amplitude of the gradient pulse interference signal component in the first ECG signal, reaching an acceptable range. Then, electromagnetic interference in the first ECG signal is removed to obtain the ECG-gated trigger signal desired by the magnetic resonance imaging system. In other words, the electromagnetic interference signal correction coefficient is used to correct the source difference between the first gradient pulse interference signal and the gradient pulse interference signal component in the first ECG signal. The first gradient pulse interference signal is collected by the acquisition antenna, while the gradient pulse interference signal in the first ECG signal is collected by the ECG electrodes.

[0073] In one embodiment of this application, the signal acquisition device further includes a wireless transceiver module connected to the signal processing module. The wireless transceiver module is wirelessly connected to a gating signal receiving unit, which is connected to the magnetic resonance scanning control unit. The gating signal receiving unit is used to receive the target ECG signal emitted by the wireless transceiver module and transmit the target ECG signal to the magnetic resonance scanning control unit.

[0074] In this embodiment, the signal acquisition device can wirelessly connect with the gate signal receiving unit via a 2.4G ISM band wireless signal. The gate signal receiving unit receives the target ECG signal from the signal acquisition device and transmits the target ECG signal to the magnetic resonance scanning control unit.

[0075] In addition, the gating signal receiving unit can also receive signals such as respiratory gating signals and pulse gating signals collected by other physiological gating signal acquisition devices configured in the magnetic resonance scanning room, or receive signals transmitted by other wireless communication devices.

[0076] The gating signal receiving unit packages these physiological gating signals into data and transmits them to the magnetic resonance scanning control unit via cable to achieve gating trigger control of the cardiac scan and improve the quality of the cardiac scan image.

[0077] In one embodiment of this application, the signal acquisition device can replace the wireless communication method with the optical fiber link communication method. The signal acquisition device can directly interconnect with the magnetic resonance scanning control unit through the optical fiber line, eliminating the gate signal receiving unit.

[0078] This application provides a signal acquisition method, applied to the aforementioned signal acquisition device, such as... Figure 4 As shown, the method includes:

[0079] Step 401: Acquire the first ECG signal and the first gradient pulse interference signal generated during the scanning process;

[0080] Step 402: Perform amplitude correction on the first gradient pulse interference signal based on the electromagnetic interference signal correction coefficient;

[0081] Step 403: Based on the amplitude-corrected first gradient pulse interference signal, filter out the electromagnetic interference signal in the first ECG signal to obtain the target ECG signal.

[0082] In this embodiment, a first gradient pulse interference signal between the first ECG signal and the magnetic resonance imaging system scan is acquired, the amplitude of the first gradient pulse interference signal is then corrected, and finally the amplitude-corrected first gradient pulse interference signal is filtered out from the first ECG signal, that is, the introduced electromagnetic interference is filtered out, reducing the loss or distortion of the ECG signal and improving the quality of the cardiac scan image of the magnetic resonance imaging system.

[0083] In one embodiment of this application, acquiring a first ECG signal and a first gradient pulse interference signal generated during the scanning process includes: acquiring a primary ECG analog signal, performing low-pass filtering and amplification on the primary ECG analog signal, and then performing analog-to-digital conversion to generate a first ECG signal; acquiring an electromagnetic interference analog signal, performing low-pass filtering and amplification on the electromagnetic interference analog signal, and then performing analog-to-digital conversion to generate a first gradient pulse interference signal.

[0084] In one embodiment of this application, the electromagnetic interference signal correction coefficient is obtained by averaging the ratio of the maximum amplitude of the second ECG signal to the maximum amplitude of the second gradient pulse interference signal within each preset time period after acquiring the second ECG signal and the second gradient pulse interference signal for n preset time periods, where n is an integer greater than or equal to 2; the amplitude correction of the first gradient pulse interference signal based on the electromagnetic interference signal correction coefficient includes: multiplying the first gradient pulse interference signal with the electromagnetic interference signal correction coefficient to obtain the amplitude-corrected first gradient pulse interference signal; and filtering out the electromagnetic interference signal in the first ECG signal based on the amplitude-corrected first gradient pulse interference signal to obtain the target ECG signal, which further includes: subtracting the first ECG signal from the amplitude-corrected first gradient pulse interference signal to obtain the target ECG signal.

[0085] In one embodiment of this application, before performing amplitude correction on the first gradient pulse interference signal based on the electromagnetic interference signal correction coefficient, the method further includes: acquiring the second ECG signal and the second gradient pulse interference signal for n preset time periods, and determining the maximum amplitude of the second ECG signal and the maximum amplitude of the second gradient pulse interference signal within each preset time period; calculating the ratio parameter between the maximum amplitude of the second ECG signal and the maximum amplitude of the second gradient pulse interference signal within each preset time period, and calculating the average value of the ratio parameter for the n preset time periods, and storing the average value as the electromagnetic interference signal correction coefficient.

[0086] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0087] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A signal acquisition apparatus, characterized by comprising: The application relates to a signal processing method and device. The signal acquisition module comprises: The ECG signal acquisition module is used for acquiring a primary ECG analog signal, and performing preprocessing on the primary ECG analog signal, and then performing analog-digital conversion to generate a first ECG signal; 2. The apparatus of claim 1, wherein, The electromagnetic interference signal acquisition module is used for acquiring an electromagnetic interference analog signal, and performing preprocessing on the electromagnetic interference analog signal, and then performing analog-digital conversion to generate a first gradient pulse interference signal. The electromagnetic interference signal acquisition module comprises: The signal acquisition antenna is used for acquiring the electromagnetic interference analog signal; 3. The apparatus of claim 2, wherein, The first filtering module is connected with the signal acquisition antenna and is used for performing low-pass filtering on the electromagnetic interference analog signal to filter out radio frequency pulse interference frequency components in the electromagnetic interference analog signal, so as to obtain a gradient pulse interference analog signal; The first amplification module is connected with the first filtering module and is used for performing amplification processing on the gradient pulse interference analog signal; The first analog-digital converter is connected with the first amplification module and is used for performing analog-digital conversion on the gradient pulse interference signal after amplification processing, so as to generate a first gradient pulse interference signal. The ECG signal acquisition module comprises: The signal acquisition interface is connected with the lead wire of the ECG electrode and is used for acquiring the primary ECG analog signal; 4. The apparatus of claim 3, wherein, The second filtering module is connected with the signal acquisition interface and is used for performing low-pass filtering on the primary ECG analog signal to filter out radio frequency pulse interference frequency components in the primary ECG analog signal, so as to generate a secondary ECG analog signal; The second amplification module is connected with the second filtering module and is used for performing amplification processing on the secondary ECG analog signal; The second analog-digital converter is connected with the second amplification module and is used for performing analog-digital conversion on the secondary ECG analog signal after amplification processing, so as to generate a first ECG signal. ​ ​ 5. The apparatus of claim 4, wherein, Further comprising a shielding shell, the first and second filtering modules, the first and second amplifying modules, the first and second analog-to-digital converters and the signal processing module are arranged in the shielding shell, and a signal collecting part of the signal collecting antenna is arranged outside the shielding shell.

6. A signal acquisition method characterized by comprising: Comprise: Obtain a first ECG signal and a first gradient pulse interference signal generated during a scanning process; wherein the manner of obtaining the first gradient pulse interference signal comprises: obtaining an electromagnetic interference analog signal, and sequentially performing low-pass filtering and amplification processing on the electromagnetic interference analog signal, and then performing analog-to-digital conversion to obtain a preprocessed result; Multiply the first gradient pulse interference signal by an electromagnetic interference signal correction coefficient to obtain a first gradient pulse interference signal with amplitude correction; wherein the electromagnetic interference signal correction coefficient is obtained by calculating the ratio of the maximum amplitude of the second ECG signal to the maximum amplitude of the second gradient pulse interference signal in each preset time period after obtaining the second ECG signal and the second gradient pulse interference signal in n preset time periods, and then averaging the ratios of the n preset time periods to obtain an average value, n is an integer greater than or equal to 2; Subtract the first ECG signal from the first gradient pulse interference signal with amplitude correction to obtain a target ECG signal.

7. The method of claim 6, wherein, Obtain a first ECG signal and a first gradient pulse interference signal generated during a scanning process, comprising: Obtain a primary ECG analog signal, and perform low-pass filtering and amplification processing on the primary ECG analog signal, and then perform analog-to-digital conversion to generate a first ECG signal; Obtain an electromagnetic interference analog signal, and perform low-pass filtering and amplification processing on the electromagnetic interference analog signal, and then perform analog-to-digital conversion to generate a first gradient pulse interference signal.

8. The method of claim 6, wherein, Before amplitude correction of the first gradient pulse interference signal based on the electromagnetic interference signal correction coefficient, further comprising: Obtain a second ECG signal and a second gradient pulse interference signal in n preset time periods, and determine the maximum amplitude of the second ECG signal and the maximum amplitude of the second gradient pulse interference signal in each preset time period, n is an integer greater than or equal to 2; Calculate the ratio of the maximum amplitude of the second ECG signal to the maximum amplitude of the second gradient pulse interference signal in each preset time period, and calculate the average value of the ratios of the n preset time periods, and store the average value as the electromagnetic interference signal correction coefficient.

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