Carotid artery position detection system
By applying an excitation current signal to the carotid artery position detection system and utilizing physiological impedance signals and a pre-trained model for carotid artery position detection, the problem of low accuracy in manual detection is solved, and high-precision automated detection is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2026-04-07
AI Technical Summary
In current non-invasive cardiac output testing, the accuracy of manually pressing and touching to determine the location of the carotid artery is not high, resulting in low detection precision.
An excitation signal generation module applies an excitation current signal to the patient, a signal acquisition module acquires physiological impedance signals, and a pre-trained carotid artery location detection model is used to automatically detect the carotid artery region. The system is then combined with information about the electrode attachment area for precise localization.
It achieves fully automated and accurate carotid artery location detection, significantly improving detection accuracy and reducing mechanical stimulation of the carotid artery.
Smart Images
Figure CN224085319U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of medical device technology, and in particular to a carotid artery position detection system. Background Technology
[0002] Non-invasive cardiac output testing is widely used in the cardiovascular field. It's a method of measuring cardiac output parameters in a non-invasive manner. In non-invasive cardiac output testing, a device needs to be connected to the carotid artery region in the patient's neck to collect and measure cardiac output parameters. Therefore, accurately identifying the carotid artery region is crucial; incorrect selection of the carotid artery region will result in lower accuracy of the measured cardiac output parameters.
[0003] Currently, the main method is to manually press and touch the area of the neck where the carotid artery is located. However, this method relies on personal experience, which makes the accuracy of carotid artery location detection low. Utility Model Content
[0004] The purpose of this application is to provide a carotid artery position detection system to achieve high-precision detection of the carotid artery position. The specific technical solution is as follows:
[0005] In a first aspect, embodiments of this application provide a carotid artery position detection system, the system comprising an excitation signal generation module, electrodes, a signal acquisition module, and a carotid artery position detection module, wherein:
[0006] The electrode includes an excitation electrode for inputting electrical signals and a monitoring electrode for monitoring electrical signals. The excitation electrode and the monitoring electrode are attached to the neck area and arranged at a preset spacing.
[0007] The output terminal of the excitation signal generation module is connected to the excitation electrode to generate an excitation current signal and apply the excitation current signal to the patient through the excitation electrode.
[0008] The input terminal of the signal acquisition module is connected to the monitoring electrode to acquire the response signal captured by the monitoring electrode and generate a physiological impedance signal using the response signal, wherein the response signal is a signal generated by the patient's physiological mechanism in response to the excitation current signal.
[0009] The input terminal of the carotid artery position detection module is connected to the output terminal of the signal acquisition module, and is used to input the physiological impedance signal and the electrode adhesion area position information into the carotid artery position detection model to obtain the carotid artery region output by the carotid artery position detection model. The carotid artery position detection model is a pre-trained model used to detect the carotid artery region.
[0010] In one embodiment of this application, the monitoring electrodes include a first monitoring electrode and a second monitoring electrode, and the signal acquisition module includes a first operational amplifier, a second operational amplifier, an instrumentation amplifier, an envelope detector, a first-order high-pass filter, a fourth-order low-pass filter, and a signal acquisition unit; wherein:
[0011] The first monitoring electrode is connected to the input terminal of the first operational amplifier, and the second monitoring electrode is connected to the input terminal of the second operational amplifier; the output terminals of the first and second operational amplifiers are connected to the input terminal of the instrumentation amplifier; the output terminal of the instrumentation amplifier is connected to the input terminal of the envelope detector, the output terminal of the envelope detector is connected to the input terminal of the first-order high-pass filter, the output terminal of the first-order high-pass filter is connected to the output terminal of the fourth-order low-pass filter, and the output terminal of the fourth-order low-pass filter is connected to the input terminal of the signal acquisition unit.
[0012] The first operational amplifier is used to amplify the first response signal captured by the first monitoring electrode and use the amplified signal as the first target signal;
[0013] The second operational amplifier is used to amplify the second response information captured by the second monitoring electrode and use the amplified signal as the second target signal;
[0014] The instrumentation amplifier is used to calculate a third target signal, which represents the voltage difference between the first target signal and the second target signal.
[0015] The envelope detector is used to extract and remove the envelope signal of the third target signal, and use the processed third target signal as the fourth target signal.
[0016] The first-order high-pass filter is used to filter out low-frequency interference signals of the fourth target signal, and the filtered fourth target signal is used as the fifth target signal.
[0017] The fourth-order low-pass filter is used to filter out high-frequency interference signals of the fifth target signal, and the filtered fifth target signal is used as the sixth target signal.
[0018] The signal acquisition device is used to convert the sixth target signal into a physiological impedance signal.
[0019] In one embodiment of this application, the envelope detector includes a rectifier diode D, a first resistor R1, and a first capacitor C1, wherein:
[0020] The input terminal of the rectifier diode D is connected to the output terminal of the instrumentation amplifier, and the output terminal is connected to one end of the first resistor R1 and the first capacitor C1, respectively.
[0021] One end of the first capacitor C1 and the first resistor R1 is also connected to the input terminal of the first-order high-pass filter, and the other end of the first capacitor C1 and the first resistor R1 is grounded.
[0022] In one embodiment of this application, the first-order high-pass filter includes a second capacitor C2, a second resistor R2, and a first operational amplifier P1, wherein:
[0023] One end of the second capacitor C2 is connected to the output terminal including the detector, and the other end is connected to one end of the second resistor R2 and the first input terminal of the first operational amplifier P1; the other end of the second resistor R2 is grounded.
[0024] The second input terminal of the first operational amplifier P1 is connected to the output terminal of the first operational amplifier P1, and the output terminal of the first operational amplifier P1 is also connected to the input terminal of the fourth-order low-pass filter.
[0025] In one embodiment of this application, the aforementioned fourth-order low-pass filter includes a third resistor R3, a fourth resistor R4, a third capacitor C3, a fourth capacitor C4, a second operational amplifier P2, a fifth resistor R5, a sixth resistor R6, a fifth capacitor C5, a sixth capacitor C6, and a third operational amplifier P3, wherein:
[0026] One end of the third resistor R3 is connected to one end of the first-order high-pass filter, and the other end is connected to one end of the third capacitor C3 and one end of the fourth resistor R4, respectively.
[0027] The other end of the fourth resistor R4 is connected to one end of the fourth capacitor C4 and the first input terminal of the second operational amplifier P2, respectively, and the other end of the fourth capacitor C4 is grounded;
[0028] The other end of the third capacitor C3 is connected to the output terminal of the second operational amplifier P2; the second input terminal of the second operational amplifier P2 is connected to the output terminal of the second operational amplifier P2, and the output terminal of the second operational amplifier P2 is also connected to one end of the fifth resistor R5.
[0029] One end of the fifth resistor R5 is connected to one end of the first-order high-pass filter, and the other end is connected to one end of the fifth capacitor C5 and one end of the sixth resistor R6, respectively.
[0030] The other end of the sixth resistor R6 is connected to one end of the sixth capacitor C6 and the first input terminal of the third operational amplifier P3, and the other end of the sixth capacitor C6 is grounded.
[0031] The other end of the fifth capacitor C5 is connected to the output terminal of the third operational amplifier P3; the second input terminal of the third operational amplifier P3 is connected to the output terminal of the third operational amplifier P3, and the output terminal of the third operational amplifier P3 is also connected to one end of the fifth resistor R5.
[0032] In one embodiment of this application, the excitation electrode includes a first excitation electrode and a second excitation electrode, wherein the first excitation electrode is connected to the output terminal of the excitation signal generation module, and the second excitation electrode is grounded;
[0033] The electrode spacing between the first excitation electrode and the second excitation electrode is between 3.7 cm and 4.2 cm, and the electrode spacing between the first monitoring electrode and the second monitoring electrode is between 1.5 cm and 2.5 cm. The electrode sheet area of each of the first monitoring electrode, the second monitoring electrode, the first excitation electrode, and the second excitation electrode is 1.5 cm². 2 -2.5cm 2 Between the first monitoring electrode, the second monitoring electrode, the first excitation electrode, the second excitation electrode and the skin, the contact material is gel or silicone.
[0034] As can be seen from the above, the system provided in this application applies an excitation current signal to the patient through the excitation signal generation module and the excitation electrode. The signal acquisition module then acquires the physiological impedance signal generated by the patient in response to the excitation current signal. The carotid artery position detection module uses the physiological impedance signal and the electrode adhesion area to detect the carotid artery region using the carotid artery position detection model. It can be seen that the carotid artery position detection system achieves fully automatic carotid artery region detection, which significantly improves the accuracy of carotid artery position detection compared to manual detection.
[0035] Furthermore, in the carotid artery position detection system, on the one hand, impedance signals are used to detect the carotid artery region. Impedance signals can accurately and sensitively characterize the physiological impedance changes in the patient's neck, thereby enabling accurate detection of the carotid artery region. On the other hand, the carotid artery position detection module uses a pre-trained carotid artery position detection module for detection. Combining the above two aspects, the accuracy of carotid artery position detection is further improved.
[0036] Of course, implementing any product or method of this application does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description
[0037] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these drawings.
[0038] Figure 1 This is a schematic diagram of a carotid artery position detection system provided in an embodiment of this application;
[0039] Figure 2 This application provides a schematic diagram of the circuit structure of a signal acquisition module according to an embodiment of the present application.
[0040] Figure 3 A circuit structure diagram of an envelope detector provided in an embodiment of this application;
[0041] Figure 4 A schematic diagram of the circuit structure of a first-order high-pass filter provided in an embodiment of this application;
[0042] Figure 5 This is a schematic diagram of the circuit structure of a fourth-order low-pass filter provided in an embodiment of this application. Detailed Implementation
[0043] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art based on this application are within the scope of protection of this application.
[0044] See Figure 1 , Figure 1 This is a schematic diagram of a carotid artery position detection system provided in an embodiment of this application. The system includes an excitation signal generation module 101, an electrode 102, a signal acquisition module 103, and a carotid artery position detection module 104, wherein:
[0045] 1. Electrode 102
[0046] Electrode 102 includes an excitation electrode 1021 for inputting electrical signals and a monitoring electrode 1022 for monitoring electrical signals. The excitation electrode 1021 and the monitoring electrode 1022 are attached to the patient's neck region, and the electrodes 102 are arranged at a preset spacing. The attachment area of the electrodes can be predetermined.
[0047] In one embodiment of this application, the monitoring electrode includes a first monitoring electrode and a second monitoring electrode, and the excitation electrode includes a first excitation electrode and a second excitation electrode.
[0048] The first excitation electrode is connected to the output terminal of the excitation signal generation module, and the second excitation electrode is grounded; the first monitoring electrode and the second monitoring electrode are connected to the input terminal of the signal acquisition module.
[0049] The electrode spacing between the first excitation electrode and the second excitation electrode is between 3.7 cm and 4.2 cm, and the electrode spacing between the first monitoring electrode and the second monitoring electrode is between 1.5 cm and 2.0 cm; the electrode sheet area of the first monitoring electrode, the second monitoring electrode, the first excitation electrode, and the second excitation electrode is all within 1.5 cm². 2 -2.5cm 2 Between the first monitoring electrode, the second monitoring electrode, the first excitation electrode, the second excitation electrode and the skin, the contact material is gel or silicone.
[0050] 2. Excitation signal generation module 101
[0051] The output terminal of the excitation signal generation module 101 is connected to the excitation electrode 1021 to generate an excitation current signal and apply the excitation current signal to the patient through the excitation electrode 1021.
[0052] The excitation signal generation module 101 may include a signal generator, which outputs an excitation current signal to the excitation electrode 1021 through a constant current source circuit.
[0053] The aforementioned excitation current signal can be a sinusoidal excitation current, such as 50kHz or 100kHz. The sinusoidal excitation current.
[0054] 3. Signal Acquisition Module 103
[0055] The input terminal of the signal acquisition module 103 is connected to the monitoring electrode 1022 to acquire the response signal captured by the monitoring electrode 1022 and generate a physiological impedance signal using the response signal.
[0056] The above response signal is generated by the patient's physiological mechanism in response to the excitation current signal.
[0057] For details on the specific structure of the signal acquisition module, please refer to the following sections. Figure 2 The corresponding implementation examples will not be described in detail here.
[0058] 4. Carotid artery position detection module 104
[0059] The input terminal of the carotid artery position detection module 104 is connected to the output terminal of the signal acquisition module 103, and is used to input the physiological impedance signal and the electrode pasting area position information into the carotid artery position detection model to obtain the carotid artery region output by the carotid artery position detection model.
[0060] The aforementioned carotid artery region refers to the area in the patient's neck where the actual location of the carotid artery is mapped.
[0061] The aforementioned carotid artery location detection model is a pre-trained model used to detect the carotid artery region. This model can be obtained by training an initial neural network model, such as a CNN (Convolutional Neural Network).
[0062] After the carotid artery region is detected, its location information can be displayed through the user interface, prompting the operator to bring the associated signal acquisition device close to the region to obtain accurate cardiac output parameters.
[0063] In the technical field of this application, there are methods for detecting the carotid artery region using non-invasive pressure sensors or optical components. However, installing a non-invasive pressure sensor on the patient's neck can easily subject the carotid artery to significant mechanical stimulation, resulting in low accuracy in location detection. Optical components detect by light absorption, but since the carotid artery is located deep under the skin, it is difficult to detect its location using light absorption alone. Therefore, in this application, only electrodes are attached to the patient's neck region, resulting in less stimulation of the carotid artery, and impedance signal detection is used to improve detection accuracy.
[0064] As can be seen from the above, the system provided in this application applies an excitation current signal to the patient through the excitation signal generation module and the excitation electrode. The signal acquisition module then acquires the physiological impedance signal generated by the patient in response to the excitation current signal. The carotid artery position detection module uses the physiological impedance signal and the electrode adhesion area to detect the carotid artery region using the carotid artery position detection model. It can be seen that the carotid artery position detection system achieves fully automatic carotid artery region detection, which significantly improves the accuracy of carotid artery position detection compared to manual detection.
[0065] Furthermore, in the carotid artery position detection system, on the one hand, impedance signals are used to detect the carotid artery region. Impedance signals can accurately and sensitively characterize the physiological impedance changes in the patient's neck, thereby enabling accurate detection of the carotid artery region. On the other hand, the carotid artery position detection module uses a pre-trained carotid artery position detection module for detection. Combining the above two aspects, the accuracy of carotid artery position detection is further improved.
[0066] The foregoing Figure 1 The specific circuit structure of the signal acquisition module in the corresponding embodiment can be found below. Figure 2 Corresponding implementation examples. See also Figure 2 , Figure 2 This is a schematic diagram of the circuit structure of a signal acquisition module provided in an embodiment of this application.
[0067] In this embodiment, the monitoring electrodes include a first monitoring electrode 2011 and a second monitoring electrode 2012.
[0068] The signal acquisition module includes a first operational amplifier 2021, a second operational amplifier 2022, an instrumentation amplifier 203, an envelope detector 204, a first-order high-pass filter 205, a fourth-order low-pass filter 206, and a signal acquisition unit 207; wherein:
[0069] The first monitoring electrode 2011 is connected to the input terminal of the first operational amplifier 2021, and the second monitoring electrode 2012 is connected to the input terminal of the second operational amplifier 2022. The output terminals of the first operational amplifier 2021 and the second operational amplifier 2022 are connected to the input terminal of the instrumentation amplifier 203. The output terminal of the instrumentation amplifier 203 is connected to the input terminal of the envelope detector 204, the output terminal of the envelope detector 204 is connected to the input terminal of the first-order high-pass filter 205, the output terminal of the first-order high-pass filter 205 is connected to the output terminal of the fourth-order low-pass filter 206, and the output terminal of the fourth-order low-pass filter 206 is connected to the input terminal of the signal acquisition unit 207.
[0070] The first operational amplifier 2021 is used to amplify the first response signal captured by the first monitoring electrode 2011 and use the amplified signal as the first target signal.
[0071] The second operational amplifier 2022 is used to amplify the second response information captured by the second monitoring electrode 2012 and use the amplified signal as the second target signal.
[0072] Instrumentation amplifier 203 is used to calculate a third target signal, which is the voltage difference between the first target signal and the second target signal.
[0073] Envelope detector 204 is used to extract and remove the envelope signal of the third target signal, and use the processed third target signal as the fourth target signal;
[0074] A first-order high-pass filter 205 is used to filter out low-frequency interference signals of the fourth target signal, and the filtered fourth target signal is used as the fifth target signal.
[0075] The fourth-order low-pass filter 206 is used to filter out the high-frequency interference signal of the fifth target signal and use the filtered fifth target signal as the sixth target signal.
[0076] Signal acquisition unit 207 is used to convert the sixth target signal into a physiological impedance signal.
[0077] The method for converting physiological impedance signals is as follows: using a preset signal correspondence, the impedance signal corresponding to the sixth target signal is determined as the physiological impedance signal.
[0078] The foregoing Figure 2 The envelope detector in the corresponding embodiment has a specific circuit structure that can be found below. Figure 3 Corresponding implementation examples. See also Figure 3 , Figure 3 This is a schematic diagram of the circuit structure of an envelope detector provided in an embodiment of this application.
[0079] The envelope detector includes a rectifier diode D, a first resistor R1, and a first capacitor C1, wherein:
[0080] The input terminal of the rectifier diode D is connected to the output terminal of the instrumentation amplifier, and the output terminal is connected to one end of the first resistor R1 and the first capacitor C1, respectively.
[0081] One end of the first capacitor C1 and the first resistor R1 is also connected to the input terminal of the first-order high-pass filter, and the other end of the first capacitor C1 and the first resistor R1 is grounded.
[0082] The foregoing Figure 2 The first-order high-pass filter in the corresponding embodiment, the specific circuit structure of which can be found below. Figure 4 Corresponding implementation examples. See also Figure 4 , Figure 4 This is a schematic diagram of the circuit structure of a first-order high-pass filter provided in an embodiment of this application.
[0083] The first-order high-pass filter includes a second capacitor C2, a second resistor R2, and a first operational amplifier P1, wherein:
[0084] One end of the second capacitor C2 is connected to the output terminal including the detector, and the other end is connected to one end of the second resistor R2 and the first input terminal of the first operational amplifier P1; the other end of the second resistor R2 is grounded.
[0085] The second input terminal of the first operational amplifier P1 is connected to the output terminal of the first operational amplifier P1, and the output terminal of the first operational amplifier P1 is also connected to the input terminal of the fourth-order low-pass filter.
[0086] The foregoing Figure 2 The fourth-order low-pass filter in the corresponding embodiment has a specific circuit structure as shown below. Figure 5 Corresponding implementation examples. See also Figure 5 , Figure 5 This is a schematic diagram of the circuit structure of a fourth-order low-pass filter provided in an embodiment of this application.
[0087] The fourth-order low-pass filter includes a third resistor R3, a fourth resistor R4, a third capacitor C3, a fourth capacitor C4, a second operational amplifier P2, a fifth resistor R5, a sixth resistor R6, a fifth capacitor C5, a sixth capacitor C6, and a third operational amplifier P3, wherein:
[0088] One end of the third resistor R3 is connected to one end of the first-order high-pass filter, and the other end is connected to one end of the third capacitor C3 and one end of the fourth resistor R4.
[0089] The other end of the fourth resistor R4 is connected to one end of the fourth capacitor C4 and the first input terminal of the second operational amplifier P2, and the other end of the fourth capacitor C4 is grounded.
[0090] The other end of the third capacitor C3 is connected to the output of the second operational amplifier P2; the second input of the second operational amplifier P2 is connected to the output of the second operational amplifier P2; the output of the second operational amplifier P2 is also connected to one end of the fifth resistor R5.
[0091] One end of the fifth resistor R5 is connected to one end of the first-order high-pass filter, and the other end is connected to one end of the fifth capacitor C5 and one end of the sixth resistor R6.
[0092] The other end of the sixth resistor R6 is connected to one end of the sixth capacitor C6 and the first input terminal of the third operational amplifier P3, and the other end of the sixth capacitor C6 is grounded.
[0093] The other end of the fifth capacitor C5 is connected to the output of the third operational amplifier P3; the second input of the third operational amplifier P3 is connected to the output of the third operational amplifier P3, and the output of the third operational amplifier P3 is also connected to one end of the fifth resistor R5.
[0094] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, 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 said element.
[0095] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the embodiments of the method, ventricular catheter pump, controller, and computer-readable storage medium are basically similar to the method embodiments, and therefore the descriptions are relatively simple; relevant parts can be referred to the descriptions of the method embodiments.
[0096] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.
Claims
1. A carotid artery position detection system, characterized in that, The system includes an excitation signal generation module, electrodes, a signal acquisition module, and a carotid artery position detection module, wherein: The electrode includes an excitation electrode for inputting electrical signals and a monitoring electrode for monitoring electrical signals. The excitation electrode and the monitoring electrode are attached to the neck area, and the electrodes are arranged at a preset spacing. The output terminal of the excitation signal generation module is connected to the excitation electrode to generate an excitation current signal and apply the excitation current signal to the patient through the excitation electrode. The input terminal of the signal acquisition module is connected to the monitoring electrode to acquire the response signal captured by the monitoring electrode and generate a physiological impedance signal using the response signal, wherein the response signal is a signal generated by the patient's physiological mechanism in response to the excitation current signal. The input terminal of the carotid artery position detection module is connected to the output terminal of the signal acquisition module, and is used to input the physiological impedance signal and the electrode adhesion area position information into the carotid artery position detection model to obtain the carotid artery region output by the carotid artery position detection model. The carotid artery position detection model is a pre-trained model used to detect the carotid artery region.
2. The system according to claim 1, wherein the monitoring electrode comprises a first monitoring electrode and a second monitoring electrode, and the signal acquisition module comprises a first operational amplifier, a second operational amplifier, an instrumentation amplifier, an envelope detector, a first-order high-pass filter, a fourth-order low-pass filter, and a signal acquisition unit; wherein: The first monitoring electrode is connected to the input terminal of the first operational amplifier, and the second monitoring electrode is connected to the input terminal of the second operational amplifier; the output terminals of the first and second operational amplifiers are connected to the input terminal of the instrumentation amplifier; the output terminal of the instrumentation amplifier is connected to the input terminal of the envelope detector, the output terminal of the envelope detector is connected to the input terminal of the first-order high-pass filter, the output terminal of the first-order high-pass filter is connected to the output terminal of the fourth-order low-pass filter, and the output terminal of the fourth-order low-pass filter is connected to the input terminal of the signal acquisition unit. The first operational amplifier is used to amplify the first response signal captured by the first monitoring electrode and use the amplified signal as the first target signal; The second operational amplifier is used to amplify the second response information captured by the second monitoring electrode and use the amplified signal as the second target signal; The instrumentation amplifier is used to calculate a third target signal, which represents the voltage difference between the first target signal and the second target signal. The envelope detector is used to extract and remove the envelope signal of the third target signal, and use the processed third target signal as the fourth target signal. The first-order high-pass filter is used to filter out low-frequency interference signals of the fourth target signal, and the filtered fourth target signal is used as the fifth target signal. The fourth-order low-pass filter is used to filter out high-frequency interference signals of the fifth target signal, and the filtered fifth target signal is used as the sixth target signal. The signal acquisition device is used to convert the sixth target signal into a physiological impedance signal.
3. The system according to claim 2, characterized in that, The envelope detector includes a rectifier diode (D), a first resistor (R1), and a first capacitor (C1), wherein: The input terminal of the rectifier diode (D) is connected to the output terminal of the instrumentation amplifier, and the output terminal is connected to one end of the first resistor (R1) and the first capacitor (C1), respectively. One end of the first capacitor (C1) and the first resistor (R1) is also connected to the input terminal of the first-order high-pass filter, and the other end of the first capacitor (C1) and the first resistor (R1) is grounded.
4. The system according to claim 2 or 3, characterized in that, The first-order high-pass filter includes a second capacitor (C2), a second resistor (R2), and a first operational amplifier (P1), wherein: One end of the second capacitor (C2) is connected to the output terminal of the envelope detector, and the other end is connected to one end of the second resistor (R2) and the first input terminal of the first operational amplifier (P1); the other end of the second resistor (R2) is grounded. The second input terminal of the first operational amplifier (P1) is connected to the output terminal of the first operational amplifier (P1), and the output terminal of the first operational amplifier (P1) is also connected to the input terminal of the fourth-order low-pass filter.
5. The system according to claim 2 or 3, characterized in that, The fourth-order low-pass filter includes a third resistor (R3), a fourth resistor (R4), a third capacitor (C3), a fourth capacitor (C4), a second operational amplifier (P2), a fifth resistor (R5), a sixth resistor (R6), a fifth capacitor (C5), a sixth capacitor (C6), and a third operational amplifier (P3), wherein: One end of the third resistor (R3) is connected to one end of the first-order high-pass filter, and the other end is connected to one end of the third capacitor (C3) and one end of the fourth resistor (R4); The other end of the fourth resistor (R4) is connected to one end of the fourth capacitor (C4) and the first input terminal of the second operational amplifier (P2), and the other end of the fourth capacitor (C4) is grounded. The other end of the third capacitor (C3) is connected to the output terminal of the second operational amplifier (P2); the second input terminal of the second operational amplifier (P2) is connected to the output terminal of the second operational amplifier (P2), and the output terminal of the second operational amplifier (P2) is also connected to one end of the fifth resistor (R5); One end of the fifth resistor (R5) is connected to one end of the first-order high-pass filter, and the other end is connected to one end of the fifth capacitor (C5) and one end of the sixth resistor (R6); The other end of the sixth resistor (R6) is connected to one end of the sixth capacitor (C6) and the first input terminal of the third operational amplifier (P3), and the other end of the sixth capacitor (C6) is grounded. The other end of the fifth capacitor (C5) is connected to the output of the third operational amplifier (P3); the second input of the third operational amplifier (P3) is connected to the output of the third operational amplifier (P3), and the output of the third operational amplifier (P3) is also connected to one end of the fifth resistor (R5).
6. The system according to claim 2 or 3, characterized in that, The excitation electrode includes a first excitation electrode and a second excitation electrode. The first excitation electrode is connected to the output terminal of the excitation signal generation module, and the second excitation electrode is grounded. The electrode spacing between the first excitation electrode and the second excitation electrode is between 3.7 cm and 4.2 cm, and the electrode spacing between the first monitoring electrode and the second monitoring electrode is between 1.5 cm and 2.5 cm. The electrode sheet area of each of the first monitoring electrode, the second monitoring electrode, the first excitation electrode, and the second excitation electrode is 1.5 cm². 2 -2.5cm 2 Between the first monitoring electrode, the second monitoring electrode, the first excitation electrode, the second excitation electrode and the skin, the contact material is gel or silicone.