Respiratory wave modulation circuit and monitor

Abstract

The utility model discloses a respiratory wave modulation circuit and a monitor, and relates to the technical field of medical equipment. The circuit comprises a pulse generation module, a filtering module, a balance output module, a respiratory wave modulation module and an output module. The pulse generation module is used for generating sine waves with set frequency; the filtering module is connected to filter the sine wave to generate an unbalanced sine wave; the balance output module obtains an unbalanced sine wave and converts the unbalanced sine wave to generate a balanced sine wave, and the balanced sine wave comprises a first path of sine wave and a second path of sine wave; the respiratory wave modulation module modulates the first path of sine wave and the second path of sine wave to generate a first path of modulated sine wave and a second path of modulated sine wave; the respiratory wave modulation module correspondingly generates a first path of impedance sine wave and a second path of impedance sine wave according to the respiratory impedance and the first path of modulation sine wave as well as the respiratory impedance and the second path of modulation sine wave; and the output module filters the first impedance sine wave and the second impedance sine wave to determine the respiratory wave.

Description

Technical Field

[0001] The utility model relates to the technical field of medical equipment, in particular to a respiratory wave modulation circuit and a monitor. Background Art

[0002] The existing respiratory monitoring circuit of the monitor uses the principle of respiratory impedance method, borrows the chest monitoring electrodes for measuring electrocardiogram, and uses high-frequency excitation pulses to modulate the respiratory wave signal thereon. In the respiratory modulation circuit, most of them use D flip-flops to divide the 125 kHz square wave generated by the oscillator by two to obtain a 62.5 kHz square wave, and then apply it to the human body through the electrocardiogram electrodes LL (LL represents the left leg electrode or the left lower limb electrode) and RA (RA represents the right arm electrode). Since the respiratory signal is very small, generally in the millivolt order of magnitude, it is very easy to be interfered, and it can only be used in specific occasions with less interference signals or specific non-interference signals, which brings great inconvenience. Summary of the Utility Model

[0003] The main technical problem to be solved by the utility model is to provide a respiratory wave modulation circuit capable of obtaining a clear and stable respiratory curve and its corresponding monitor.

[0004] According to a first aspect, an embodiment provides a respiratory wave modulation circuit, including:

[0005] A pulse generation module for generating a sine wave with a set frequency;

[0006] A filtering module connected to the pulse generation module to filter the sine wave to generate an unbalanced sine wave;

[0007] A balanced output module connected to the filtering module for obtaining the unbalanced sine wave, converting the unbalanced sine wave to generate a balanced sine wave; the balanced sine wave includes a first path sine wave and a second path sine wave with opposite phases;

[0008] A respiratory wave modulation module connected to the balanced output module to modulate the first path sine wave and the second path sine wave to generate a first path modulated sine wave and a second path modulated sine wave; the respiratory wave modulation module inputs the first path modulated sine wave and the second path modulated sine wave to the electrocardiogram electrode to obtain the respiratory impedance; the respiratory wave modulation module generates a first path impedance sine wave according to the respiratory impedance and the first path modulated sine wave, and generates a second path impedance sine wave according to the respiratory impedance and the second path modulated sine wave;

[0009] An output module connected to the respiratory wave modulation module for filtering the first path impedance sine wave and the second path impedance sine wave to determine the respiratory wave.

[0010] In one embodiment, the pulse generation module employs a Wien bridge oscillator circuit, and the Wien bridge oscillator circuit includes a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a capacitor C11, a capacitor C12, a diode D11, a diode D12, and an amplifier Q1;

[0011] The first end of the resistor R11 is grounded, the second end of the resistor R11 is connected to the first end of the resistor R12, the second end of the resistor R12 is connected to the first end of the resistor R14, the first end of the resistor R14 is further connected to the inverting input terminal of the amplifier Q1, and the second end of the resistor R14 is connected to the output terminal of the amplifier Q1; the input terminal of the diode D11 is connected to the output terminal of the diode D12, the output terminal of the diode D11 is connected to the input terminal of the diode D12, the first end of the resistor R14 is further connected to the input terminal of the diode D11, and the second end of the resistor R14 is further connected to the output terminal of the diode D11; the first end of the capacitor C11 is connected to the first end of the resistor R11, the second end of the capacitor C11 is connected to the non-inverting input terminal of the amplifier Q1, the non-inverting input terminal of the amplifier Q1 is further connected to the first end of the resistor R13, the second end of the resistor R13 is connected to the first end of the resistor R11, the first end of the resistor R13 is further connected to the first end of the capacitor C12, the second end of the capacitor C12 is connected to the first end of the resistor R15, the second end of the resistor R15 is connected to the output terminal of the amplifier Q1, and the output terminal of the amplifier Q1 is used to output a sine wave of a set frequency.

[0012] In one embodiment, the capacitance values of the capacitor C11 and the capacitor C12 are the same, the resistance values of the resistor R13 and the resistor R15 are the same, and the sum of the resistance values of the resistor R12 and the resistor R14 is greater than twice the resistance value of the resistor R11.

[0013] In one embodiment, the filtering module employs a first-order active filter, and the first-order active filter includes a resistor R16, a resistor R17, a capacitor C13, a capacitor C14, and an amplifier Q2;

[0014] The first end of the capacitor C13 is used to connect to the pulse generation module, the second end of the capacitor C13 is connected to the first end of the resistor R16, the second end of the resistor R16 is connected to the inverting input terminal of the amplifier Q2, and the non-inverting input terminal of the amplifier Q2 is grounded; the second end of the resistor R16 is further connected to the first end of the resistor R17, the second end of the resistor R17 is connected to the output terminal of the amplifier Q2; the first end of the resistor R16 is further connected to the first end of the capacitor C14, the second end of the capacitor C14 is connected to the output terminal of the amplifier Q2, and the output terminal of the amplifier Q2 is used to output an unbalanced sine wave.

[0015] In one embodiment, the filtering module uses capacitor C13 to amplify the sine wave of a set frequency in an alternating current manner.

[0016] In one embodiment, the balanced output module includes capacitor C15, capacitor C16, capacitor C17, resistor R18, resistor R19, resistor R20, resistor R21, amplifier Q3, and amplifier Q4.

[0017] The first end of capacitor C15 is used to connect to the filtering module. The second end of capacitor C15 is connected to the first end of resistor R18. The second end of resistor R18 is connected to the first end of resistor R19. The second end of resistor R19 is connected to the non-inverting input terminal of amplifier Q3. The second end of resistor R18 is also connected to the first end of capacitor C17. The second end of capacitor C17 is connected to the output terminal of amplifier Q3. The output terminal of amplifier Q3 is used to output the first sine wave. The second end of resistor R19 is connected to the first end of capacitor C16. The second end of capacitor C16 is grounded. The inverting input terminal of amplifier Q3 is connected to the first end of resistor R20. The second end of resistor R20 is connected to the inverting input terminal of amplifier Q4. The non-inverting input terminal of amplifier Q4 is grounded. The second end of resistor R20 is connected to the first end of resistor R21. The second end of resistor R21 is connected to the output terminal of amplifier Q4. The output terminal of amplifier Q4 is used to output the second sine wave. The inverting input terminal of amplifier Q3 is also connected to the output terminal of amplifier Q3.

[0018] In one embodiment, in the balanced output module, capacitor C15 and resistor R18 are used to perform high-pass filtering on the unbalanced sine wave, and capacitor C16 and resistor R19 are used to perform low-pass filtering on the unbalanced sine wave.

[0019] In one embodiment, the respiratory wave modulation module includes resistor R22, resistor R23, resistor R24, resistor R25, capacitor C18, capacitor C19, capacitor C20, capacitor C21, capacitor C22, and capacitor C23.

[0020] The first end of resistor R22 is used to connect to the balanced output module. The second end of resistor R22 is connected to the first end of capacitor C18. The second end of capacitor C18 is grounded. The second end of resistor R22 is also connected to the first end of resistor R24. The second end of resistor R24 is connected to the first end of capacitor C20. The second end of capacitor C20 is connected to the first end of capacitor C21. The second end of capacitor C21 is used to connect to the electrocardiogram electrode. The second end of capacitor C20 is used to output the first impedance sine wave.

[0021] The first end of the resistor R23 is used to connect to the balanced output module. The second end of the resistor R23 is connected to the first end of the capacitor C19, and the second end of the capacitor C19 is grounded. The second end of the resistor R23 is connected to the first end of the resistor R25. The second end of the resistor R25 is connected to the first end of the capacitor C22. The second end of the capacitor C22 is connected to the first end of the capacitor C23. The second end of the capacitor C23 is used to connect to the electrocardiogram electrode, and the second end of the capacitor C22 is used to output the second impedance sine wave.

[0022] In one embodiment, the output module includes a resistor R26, a resistor R27, a resistor R28, a resistor R29, a capacitor C24, a capacitor C25, a capacitor C26, and a capacitor C27.

[0023] The first end of the capacitor C24 is used to connect to the respiratory wave modulation module. The second end of the capacitor C24 is connected to the first end of the resistor R26, and the second end of the resistor R26 is grounded. The second end of the capacitor C24 is also connected to the first end of the resistor R28. The second end of the R28 is connected to the first end of the capacitor C25, and the second end of the capacitor C25 is grounded. The second end of the resistor R28 is used to output the filtered first impedance sine wave.

[0024] The first end of the capacitor C26 is used to connect to the respiratory wave modulation module. The second end of the capacitor C26 is connected to the first end of the resistor R27, and the second end of the resistor R27 is grounded. The second end of the capacitor C26 is also connected to the first end of the resistor R29. The second end of the R29 is connected to the first end of the capacitor C27, and the second end of the capacitor C27 is grounded. The second end of the resistor R29 is used to output the filtered second impedance sine wave.

[0025] According to a second aspect, an embodiment provides a monitor, which adopts the respiratory wave modulation circuit in any of the above embodiments.

[0026] The respiratory wave modulation circuit and monitor according to the above embodiments, the circuit includes a pulse generation module, a filtering module, a balanced output module, a respiratory wave modulation module, and an output module. The pulse generation module is used to generate a sine wave, and then the filtering module filters the sine wave to generate an unbalanced sine wave. Then, the balanced output module converts the unbalanced sine wave into a balanced sine wave, and the respiratory wave modulation module modulates the balanced sine wave. After modulation, the first modulated sine wave and the second modulated sine wave are applied to the human body, causing the human body impedance to exhibit an approximately pure resistance characteristic, so that a respiratory impedance that can more accurately reflect human respiration can be obtained. The respiratory impedance is applied to the first modulated sine wave and the second modulated sine wave, and thus the first impedance sine wave and the second impedance sine wave are correspondingly obtained. Finally, the output module demodulates the first impedance sine wave and the second impedance sine wave to obtain a clear and stable respiratory curve. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 FIG. is a schematic structural diagram of a respiratory wave modulation circuit according to an embodiment;

[0028] Figure 2 FIG. is a circuit diagram of a respiratory wave modulation circuit according to an embodiment;

[0029] Figure 3 FIG. is a schematic structural diagram of a monitor according to another embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0030] The present utility model will be further described in detail below in conjunction with the accompanying drawings through specific embodiments. Similar elements in different embodiments are labeled with related similar element numbers. In the following embodiments, many detailed descriptions are provided to make the present application better understood. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, and methods. In some cases, some operations related to the present application are not shown or described in the specification, which is to avoid the core part of the present application being overwhelmed by excessive descriptions. For those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the descriptions in the specification and the general technical knowledge in the art.

[0031] In addition, the features, operations, or characteristics described in the specification can be combined in any appropriate manner to form various embodiments. At the same time, the steps or actions in the method description can also be reordered or adjusted in an obvious manner by those skilled in the art. Therefore, the various sequences in the specification and drawings are only for clearly describing a certain embodiment, and do not mean that they are the necessary sequences, unless it is stated that a certain sequence must be followed.

[0032] The serial numbers assigned to components in this text itself, such as "first", "second", etc., are only used to distinguish the described objects and do not have any sequential or technical meaning. And the "connection" and "coupling" mentioned in this application, unless otherwise specified, both include direct and indirect connection (coupling).

[0033] This application provides a single-chip microcomputer anti-cracking device for preventing programs from being cracked. The device has a simple structure and low cost, and can effectively prevent others from obtaining the single-chip microcomputer program by disassembling and reverse engineering. The following is a specific elaboration.

[0034] Please refer to Figure 1 , in an embodiment, a respiratory wave modulation circuit 110 is provided, which includes a pulse generation module 111, a filtering module 112, a balanced output module 113, a respiratory wave modulation module 114, and an output module 115.

[0035] In an embodiment, the pulse generation module 111 is used to continuously generate a sine wave signal of 62.5 kHz. Among them, the pulse generation module 111 adopts a Wien bridge oscillator circuit, and the Wien bridge oscillator circuit is used to ensure the stability of the sine wave signal. The Wien bridge oscillator circuit includes an RC bridge network for generating a sine wave with low frequency, medium frequency and low distortion and an operational amplifier. The core of the Wien bridge oscillator circuit is its frequency-selective feedback network. The output terminal of the operational amplifier is fed back to the non-inverting input terminal. Part of the feedback is positive feedback (reaching the non-inverting input terminal through the frequency-selective RC branch), and the other feedback is negative feedback (reaching the inverting input terminal of the operational amplifier through the impedance branch).

[0036] Please refer to Figure 2, In one embodiment, the Wien bridge oscillator circuit includes resistor R11, resistor R12, resistor R13, resistor R14, resistor R15, capacitor C11, capacitor C12, diode D11, diode D12, and amplifier Q1. The first end of resistor R11 is grounded, the second end of resistor R11 is connected to the first end of resistor R12, and the second end of resistor R12 is connected to the first end of resistor R14. The first end of resistor R14 is also connected to the inverting input terminal of amplifier Q1, and the second end of resistor R14 is connected to the output terminal of amplifier Q1. The input terminal of diode D11 is connected to the output terminal of diode D12, and the output terminal of diode D11 is connected to the input terminal of diode D12. The first end of resistor R14 is also connected to the input terminal of diode D11, and the second end of resistor R14 is also connected to the output terminal of diode D11. The first end of capacitor C11 is connected to the first end of resistor R11, the second end of capacitor C11 is connected to the non-inverting input terminal of amplifier Q1, the non-inverting input terminal of amplifier Q1 is also connected to the first end of resistor R13, and the second end of resistor R13 is connected to the first end of resistor R11. The first end of resistor R13 is also connected to the first end of capacitor C12, the second end of capacitor C12 is connected to the first end of resistor R15, the second end of resistor R15 is connected to the output terminal of amplifier Q1, and the output terminal of amplifier Q1 is used to output a sine wave of a set frequency.

[0037] In one embodiment, in the pulse generation module 111, the capacitance values of capacitor C11 and capacitor C12 are the same, the resistance values of resistor R13 and resistor R15 are the same, and the sum of the resistance values of resistor R12 and resistor R14 is greater than twice the resistance value of resistor R11.

[0038] In one embodiment, the filtering module 112 is connected to the pulse generation module 111 to filter the sine wave to generate an unbalanced sine wave, where the unbalanced sine wave is a single-ended signal. The filtering module 112 uses a first-order active filter to block direct current (remove the DC component) and filter out low-frequency components, only retaining the sine wave signal of 62.5 kHz.

[0039] Please refer to Figure 2 , In one embodiment, the first-order active filter includes resistor R16, resistor R17, capacitor C13, capacitor C14, and amplifier Q2. The first end of capacitor C13 is used to connect to the pulse generation module 111, the second end of capacitor C13 is connected to the first end of resistor R16, the second end of resistor R16 is connected to the inverting input terminal of amplifier Q2, and the non-inverting input terminal of amplifier Q2 is grounded. The second end of resistor R16 is also connected to the first end of resistor R17, and the second end of resistor R17 is connected to the output terminal of amplifier Q2. The first end of resistor R16 is also connected to the first end of capacitor C14, the second end of capacitor C14 is connected to the output terminal of amplifier Q2, and the output terminal of amplifier Q2 is used to output an unbalanced sine wave.

[0040] In one embodiment, a first-order active filter employs a coupling capacitor C13. The capacitor C13 prevents the circuit from generating DC amplification. Thus, the first-order active filter only amplifies the AC sine wave and has an amplitude-frequency characteristic of 20 dB per octave. The cut-off frequency and gain of the first-order active filter are calculated using the following formulas:

[0041]

[0042] where F0 represents the cut-off frequency of the first-order active filter, R R17 represents the resistance value of resistor R17, and C C14 represents the capacitance value of capacitor C14; Gain represents the gain of the first-order active filter, and R R16 represents the resistance value of resistor R16.

[0043] In one embodiment, a balanced output module 113 is connected to the filtering module 112. The balanced output module 113 obtains an unbalanced sine wave, thereby converting the unbalanced sine wave to generate a balanced sine wave. The balanced sine wave includes a first sine wave and a second sine wave with opposite phases. The balanced output module 113 converts the unbalanced input sine wave into a balanced sine wave output. The balanced sine wave consists of two sine waves with opposite phases. Among them, the first sine wave signal is positive with a phase of 0 degrees, the second sine wave signal is negative with a phase of 180 degrees, and the amplitudes of the first sine wave and the second sine wave are equal.

[0044] Please refer to Figure 2 , in one embodiment, the balanced output module 113 includes a capacitor C15, a capacitor C16, a capacitor C17, a resistor R18, a resistor R19, a resistor R20, a resistor R21, an amplifier Q3, and an amplifier Q4. The first end of the capacitor C15 is used to connect to the filtering module 112. The second end of the capacitor C15 is connected to the first end of the resistor R18. The second end of the resistor R18 is connected to the first end of the resistor R19. The second end of the resistor R19 is connected to the non-inverting input terminal of the amplifier Q3. The second end of the resistor R18 is also connected to the first end of the capacitor C17. The second end of the capacitor C17 is connected to the output terminal of the amplifier Q3. The output terminal of the amplifier Q3 is used to output the first sine wave. The second end of the resistor R19 is connected to the first end of the capacitor C16. The second end of the capacitor C16 is grounded. The inverting input terminal of the amplifier Q3 is connected to the first end of the resistor R20. The second end of the resistor R20 is connected to the inverting input terminal of the amplifier Q4. The non-inverting input terminal of the amplifier Q4 is grounded. The second end of the resistor R20 is connected to the first end of the resistor R21. The second end of the resistor R21 is connected to the output terminal of the amplifier Q4. The output terminal of the amplifier Q4 is used to output the second sine wave. The inverting input terminal of the amplifier Q3 is also connected to the output terminal of the amplifier Q3.

[0045] In one embodiment, in the balanced output module 113, the non - balanced sine wave is subjected to high - pass filtering using capacitor C15 and resistor R18, and low - pass filtering using capacitor C16 and resistor R19. The balanced output module 113 can effectively filter out the low - frequency components and high - frequency interference in the non - balanced sine wave through low - pass and high - pass filtering, so that the waveform of the non - balanced sine wave is flat within the frequency response range and has strong common - mode rejection ability.

[0046] In one embodiment, the respiration - wave modulation module 114 modulates the first - path sine wave and the second - path sine wave to generate a first - path modulated sine wave and a second - path modulated sine wave. The respiration - wave modulation module 114 inputs the first - path modulated sine wave and the second - path modulated sine wave to the electrocardiogram electrodes to obtain the respiration impedance. Among them, the respiration - wave modulation module 114 inputs the first - path modulated sine wave to the electrocardiogram electrode of LL - IN, and the respiration - wave modulation module 114 inputs the second - path modulated sine wave to the electrocardiogram electrode of RA - IN. The electrocardiogram electrodes of LL - IN and RA - IN are applied to the human body, and a respiration impedance will be generated between the two electrodes due to respiration. The respiration - wave modulation module 114 generates a first - path impedance sine wave based on the respiration impedance and the first - path modulated sine wave, and also generates a second - path impedance sine wave based on the respiration impedance and the second - path modulated sine wave.

[0047] It should be noted that LL - IN (Left Leg Input) and RA - IN (Right Arm Input) are input electrodes, which are usually used to inject signals or collect bio - electrical signals. LL - IN is usually placed on the left leg or left ankle, and RA - IN is usually placed on the right arm or right wrist.

[0048] Please refer to Figure 2, In one embodiment, the respiratory wave modulation module 114 includes a resistor R22, a resistor R23, a resistor R24, a resistor R25, a capacitor C18, a capacitor C19, a capacitor C20, a capacitor C21, a capacitor C22, and a capacitor C23. The first end of the resistor R22 is used to connect to the balanced output module 113, the second end of the resistor R22 is connected to the first end of the capacitor C18, and the second end of the capacitor C18 is grounded. The second end of the resistor R22 is also connected to the first end of the resistor R24, the second end of the resistor R24 is connected to the first end of the capacitor C20, the second end of the capacitor C20 is connected to the first end of the capacitor C21, the second end of the capacitor C21 is used to connect to an electrocardiogram electrode (i.e., the LL-IN electrode), and the second end of the capacitor C20 is used to output the first impedance sine wave. The first end of the resistor R23 is used to connect to the balanced output module 113, the second end of the resistor R23 is connected to the first end of the capacitor C19, and the second end of the capacitor C19 is grounded. The second end of the resistor R23 is connected to the first end of the resistor R25, the second end of the resistor R25 is connected to the first end of the capacitor C22, the second end of the capacitor C22 is connected to the first end of the capacitor C23, the second end of the capacitor C23 is used to connect to an electrocardiogram electrode (i.e., the RA-IN electrode), and the second end of the capacitor C22 is used to output the second impedance sine wave.

[0049] In one embodiment, the respiratory wave modulation module 114 is added to the human body through T-type low-pass filtering and then through a DC-blocking capacitor, thereby ensuring the electrical safety of the human body.

[0050] In one embodiment, the output module 115 acquires the first impedance sine wave and the second impedance sine wave, filters the first impedance sine wave and the second impedance sine wave, and determines the respiratory wave based on the filtered first impedance sine wave and second impedance sine wave.

[0051] In one embodiment, the output module 115 adopts a band-pass filtering output module. After the first impedance sine wave and the second impedance sine wave containing the human respiratory impedance are demodulated, they contain a large amount of DC components and high-frequency noise, and need to be subjected to high-pass filtering and low-pass filtering. Therefore, the band-pass filtering output module can be regarded as a series connection of a high-pass filter and a low-pass filter. Extremely low-frequency and extremely high-frequency components can be completely blocked by the band-pass filtering output module and cannot pass through. Only the signal frequency components located within the frequency passband can pass through, and no additional noise will be generated in this signal frequency.

[0052] Please refer to Figure 2, In one embodiment, the output module 115 includes resistor R26, resistor R27, resistor R28, resistor R29, capacitor C24, capacitor C25, capacitor C26, and capacitor C27. The first end of capacitor C24 is used to connect to the respiratory wave modulation module 114. The second end of capacitor C24 is connected to the first end of resistor R26, and the second end of resistor R26 is grounded. The second end of capacitor C24 is also connected to the first end of resistor R28. The second end of R28 is connected to the first end of capacitor C25. The second end of capacitor C25 is grounded. The second end of resistor R28 is connected to the LL-OUT output electrode for outputting the filtered first-path impedance sine wave. The first end of capacitor C26 is used to connect to the respiratory wave modulation module 114. The second end of capacitor C26 is connected to the first end of resistor R27, and the second end of resistor R27 is grounded. The second end of capacitor C26 is also connected to the first end of resistor R29. The second end of R29 is connected to the first end of capacitor C27. The second end of capacitor C27 is grounded. The second end of resistor R29 is connected to the RA-OUT output electrode for outputting the filtered second-path impedance sine wave. The LL-OUT output electrode and the RA-OUT output electrode are connected to the MCU acquisition circuit, so as to determine the respiratory wave according to the respiratory wave signals included in the filtered first-path impedance sine wave and the second-path impedance sine wave.

[0053] It should be noted that LL-OUT (Left Leg Output) and RA-OUT (Right Arm Output) are output electrodes, which are usually used to receive signals transmitted from the human body. The positions of LL-OUT and RA-OUT are the same as those of LL-IN and RA-IN, corresponding to the left leg and the right arm respectively.

[0054] Please refer to Figure 3 , In another embodiment, a monitor 100 is provided. The monitor 100 includes a respiratory wave modulation circuit 110, where the respiratory wave modulation circuit 110 adopts the respiratory wave modulation circuit 110 in any of the above embodiments. Since the respiratory wave modulation circuit 110 has been clearly described in the above embodiments, it will not be elaborated here.

[0055] The above uses specific examples to elaborate on the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the art of the present invention, according to the idea of the present invention, several simple deductions, deformations or substitutions can also be made.

Claims

1. A respiratory wave modulation circuit, characterized in that, Comprising: A pulse generation module for generating a sine wave of a set frequency; A filtering module connected to the pulse generation module for filtering the sine wave to generate an unbalanced sine wave; A balanced output module connected to the filtering module for obtaining the unbalanced sine wave and converting the unbalanced sine wave to generate a balanced sine wave; The balanced sine wave includes a first sine wave and a second sine wave with opposite phases; A respiratory wave modulation module connected to the balanced output module for modulating the first sine wave and the second sine wave to generate a first modulated sine wave and a second modulated sine wave; The respiratory wave modulation module inputs the first modulated sine wave and the second modulated sine wave to an electrocardiogram electrode to obtain a respiratory impedance; The respiratory wave modulation module generates a first impedance sine wave based on the respiratory impedance and the first modulated sine wave, and generates a second impedance sine wave based on the respiratory impedance and the second modulated sine wave; An output module connected to the respiratory wave modulation module for filtering the first impedance sine wave and the second impedance sine wave to determine a respiratory wave.

2. The respiratory wave modulation circuit according to claim 1, characterized in that The pulse generation module adopts a Wien bridge oscillator circuit, and the Wien bridge oscillator circuit includes a resistor R11, a resistor R12, a resistor R13, a resistor R14, a resistor R15, a capacitor C11, a capacitor C12, a diode D11, a diode D12, and an amplifier Q1; The first end of the resistor R11 is grounded, the second end of the resistor R11 is connected to the first end of the resistor R12, the second end of the resistor R12 is connected to the first end of the resistor R14, the first end of the resistor R14 is also connected to the inverting input terminal of the amplifier Q1, and the second end of the resistor R14 is connected to the output terminal of the amplifier Q1; the input terminal of the diode D11 is connected to the output terminal of the diode D12, the output terminal of the diode D11 is connected to the input terminal of the diode D12, the first end of the resistor R14 is also connected to the input terminal of the diode D11, and the second end of the resistor R14 is also connected to the output terminal of the diode D11; the first end of the capacitor C11 is connected to the first end of the resistor R11, the second end of the capacitor C11 is connected to the non-inverting input terminal of the amplifier Q1, the non-inverting input terminal of the amplifier Q1 is also connected to the first end of the resistor R13, the second end of the resistor R13 is connected to the first end of the resistor R11, the first end of the resistor R13 is also connected to the first end of the capacitor C12, the second end of the capacitor C12 is connected to the first end of the resistor R15, the second end of the resistor R15 is connected to the output terminal of the amplifier Q1, and the output terminal of the amplifier Q1 is used to output a sine wave of a set frequency.

3. The respiratory wave modulation circuit according to claim 2, wherein In the pulse generation module, the capacitance values of the capacitor C11 and the capacitor C12 are the same, the resistance values of the resistor R13 and the resistor R15 are the same, and the sum of the resistance values of the resistor R12 and the resistor R14 is greater than twice the resistance value of the resistor R11.

4. The breathing wave modulation circuit according to claim 1, wherein The filtering module uses a first-order active filter, and the first-order active filter includes a resistor R16, a resistor R17, a capacitor C13, a capacitor C14, and an amplifier Q2; The first end of the capacitor C13 is used to connect to the pulse generation module. The second end of the capacitor C13 is connected to the first end of the resistor R16. The second end of the resistor R16 is connected to the inverting input terminal of the amplifier Q2. The non-inverting input terminal of the amplifier Q2 is grounded. The second end of the resistor R16 is also connected to the first end of the resistor R17. The second end of the resistor R17 is connected to the output terminal of the amplifier Q2. The first end of the resistor R16 is also connected to the first end of the capacitor C14. The second end of the capacitor C14 is connected to the output terminal of the amplifier Q2. The output terminal of the amplifier Q2 is used to output an unbalanced sine wave.

5. The respiratory wave modulation circuit according to claim 4, wherein The filtering module uses the capacitor C13 to perform AC amplification on the sine wave of the set frequency.

6. The respiratory wave modulation circuit according to claim 1, wherein The balanced output module includes a capacitor C15, a capacitor C16, a capacitor C17, a resistor R18, a resistor R19, a resistor R20, a resistor R21, an amplifier Q3, and an amplifier Q4; The first end of the capacitor C15 is used to connect to the filtering module. The second end of the capacitor C15 is connected to the first end of the resistor R18. The second end of the resistor R18 is connected to the first end of the resistor R19. The second end of the resistor R19 is connected to the non-inverting input terminal of the amplifier Q3. The second end of the resistor R18 is also connected to the first end of the capacitor C17. The second end of the capacitor C17 is connected to the output terminal of the amplifier Q3. The output terminal of the amplifier Q3 is used to output the first path of sine wave. The second end of the resistor R19 is connected to the first end of the capacitor C16. The second end of the capacitor C16 is grounded. The inverting input terminal of the amplifier Q3 is connected to the first end of the resistor R20. The second end of the resistor R20 is connected to the inverting input terminal of the amplifier Q4. The non-inverting input terminal of the amplifier Q4 is grounded. The second end of the resistor R20 is connected to the first end of the resistor R21. The second end of the resistor R21 is connected to the output terminal of the amplifier Q4. The output terminal of the amplifier Q4 is used to output the second path of sine wave. The inverting input terminal of the amplifier Q3 is also connected to the output terminal of the amplifier Q3.

7. The respiratory wave modulation circuit according to claim 6, wherein, In the balanced output module, the capacitor C15 and the resistor R18 are used to perform high-pass filtering on the unbalanced sine wave, and the capacitor C16 and the resistor R19 are used to perform low-pass filtering on the unbalanced sine wave.

8. The breathing wave modulation circuit according to claim 1, wherein, The respiration wave modulation module includes a resistor R22, a resistor R23, a resistor R24, a resistor R25, a capacitor C18, a capacitor C19, a capacitor C20, a capacitor C21, a capacitor C22, and a capacitor C23; The first end of the resistor R22 is used to connect to the balanced output module. The second end of the resistor R22 is connected to the first end of the capacitor C18, and the second end of the capacitor C18 is grounded; the second end of the resistor R22 is also connected to the first end of the resistor R24. The second end of the resistor R24 is connected to the first end of the capacitor C20, the second end of the capacitor C20 is connected to the first end of the capacitor C21, and the second end of the capacitor C21 is used to connect to the electrocardiogram electrode. The second end of the capacitor C20 is used to output the first impedance sine wave. The first end of the resistor R23 is used to connect to the balanced output module. The second end of the resistor R23 is connected to the first end of the capacitor C19, and the second end of the capacitor C19 is grounded; the second end of the resistor R23 is connected to the first end of the resistor R25. The second end of the resistor R25 is connected to the first end of the capacitor C22, the second end of the capacitor C22 is connected to the first end of the capacitor C23, and the second end of the capacitor C23 is used to connect to the electrocardiogram electrode. The second end of the capacitor C22 is used to output the second impedance sine wave.

9. The respiratory wave modulation circuit according to claim 1, wherein The output module includes a resistor R26, a resistor R27, a resistor R28, a resistor R29, a capacitor C24, a capacitor C25, a capacitor C26, and a capacitor C27. The first end of the capacitor C24 is used to connect to the respiratory wave modulation module. The second end of the capacitor C24 is connected to the first end of the resistor R26, and the second end of the resistor R26 is grounded; the second end of the capacitor C24 is also connected to the first end of the resistor R28. The second end of the R28 is connected to the first end of the capacitor C25, the second end of the capacitor C25 is grounded, and the second end of the resistor R28 is used to output the filtered first impedance sine wave. The first end of the capacitor C26 is used to connect to the respiratory wave modulation module. The second end of the capacitor C26 is connected to the first end of the resistor R27, and the second end of the resistor R27 is grounded; the second end of the capacitor C26 is also connected to the first end of the resistor R29. The second end of the R29 is connected to the first end of the capacitor C27, the second end of the capacitor C27 is grounded, and the second end of the resistor R29 is used to output the filtered second impedance sine wave.

10. A monitor, characterized in that, It includes the respiratory wave modulation circuit according to any one of claims 1-9.

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