Flow signal detection circuit for breathing machine

Abstract

The utility model discloses a flow signal detection circuit for a breathing machine. The flow signal detection circuit comprises a first pressure sensor, a second pressure sensor, a first amplification module, a second amplification module, a differential processing module, a following type voltage supply module, a third amplification module and a total voltage supply module, the first pressure sensor and the second pressure sensor are both mounted at an air outlet of the breathing machine; the output end of the first pressure sensor is connected to the input end of the first amplification module, and the output end of the second pressure sensor is connected to the input end of the second amplification module; the differential processing module comprises a first differential amplifier U1, a second differential amplifier U2 and a load series circuit unit. The in-phase input end of the first differential amplifier U1 is connected to the output end of the first amplification module. The flow signal detection circuit for the breathing machine solves the problem that in the prior art, due to the fact that only one first pressure sensor is arranged at an air outlet, the air supply pressure detection result is not accurate.

Description

Technical Field

[0001] The utility model relates to a ventilator circuit, in particular to a flow signal detection circuit for a ventilator. Background Art

[0002] A Chinese patent discloses a detection device and a ventilator with an application number of: CN202223521407.8. The said detection device includes: a first flow sensor, a second flow sensor, a first pressure sensor and an oxygen concentration sensor; the first flow sensor, the first pressure sensor and the oxygen concentration sensor are arranged at the air supply port of the ventilator and are respectively used for detecting the air supply flow rate of the ventilator / setting the first tidal volume of the lung model or the subject, the air supply pressure and the air supply oxygen concentration; the second flow sensor is arranged at the collection port of the ventilator and is used for detecting the second tidal volume of the set lung model or the subject.

[0003] Although the detection device and the ventilator can test the first tidal volume and the air supply pressure by arranging a first flow sensor and a first pressure sensor at the air supply port. However, the detection device and the ventilator still have the following disadvantages: since only the detection result of a first pressure sensor is set at the air supply port to calculate the air supply pressure, the detection result of the air supply pressure is inaccurate. Summary of the Utility Model

[0004] The utility model aims to provide a flow signal detection circuit for a ventilator to solve the problem that the detection result of the air supply pressure is inaccurate in the prior art due to only arranging a first pressure sensor at the air outlet.

[0005] To achieve the above object, the utility model adopts the following technical scheme:

[0006] The utility model discloses a flow signal detection circuit for a ventilator, including: a first pressure sensor, a second pressure sensor, a first amplification module, a second amplification module, a differential processing module, a follower voltage supply module, a third amplification module and a total voltage supply module;

[0007] Both the first pressure sensor and the second pressure sensor are installed at the air outlet of the ventilator, and both the first pressure sensor and the second pressure sensor are used for detecting the air supply pressure at the air outlet; the output end of the first pressure sensor is connected to the input end of the first amplification module, and the output end of the second pressure sensor is connected to the input end of the second amplification module;

[0008] The differential processing module includes: a first differential amplifier U1, a second differential amplifier U2 and a load series circuit unit. The non-inverting input end of the first differential amplifier U1 is connected to the output end of the first amplification module, and the non-inverting input end of the second differential amplifier U2 is connected to the output end of the second amplification module;

[0009] The total power supply module is provided with a first voltage output terminal, a second voltage output terminal and a third voltage output terminal. The first voltage output terminal and the second voltage output terminal supply power to the third amplification module, the first differential amplifier U1 and the second differential amplifier U2. The third voltage output terminal is connected to the input end of the follower voltage supply module;

[0010] The load series circuit unit is provided with a first differential signal input terminal, a second differential signal input terminal, a first voltage division supply terminal and a second voltage division supply terminal. The first differential signal input terminal is connected to the output terminal of the first differential amplifier U1, the second differential signal input terminal is connected to the output terminal of the second differential amplifier U2, the first voltage division supply terminal is connected to the non-inverting input terminal of the first differential amplifier U1, and the first voltage division supply terminal is connected to the non-inverting input terminal of the second differential amplifier U2;

[0011] One end of the load series circuit unit is a low-voltage input terminal, and the other end is a high-voltage output terminal; the high-voltage output terminal of the load series circuit unit is the output terminal of the differential processing module, the output terminal of the differential processing module is connected to the input terminal of the third amplification module, and the output terminal of the follower voltage supply module supplies power to the reference voltage terminal of the third amplification module and the low-voltage input terminal of the load series circuit unit.

[0012] Preferably, the load series circuit unit includes: a first load R1, a second load R2, a third load R3, a fourth load R4 and a fifth load R5. The middle of the load series circuit unit is provided with a first connection terminal, a second connection terminal, a third connection terminal and a fourth connection terminal. The voltage at the location of the first connection terminal is lower than the voltage at the high-voltage output terminal, and the fourth load R4 is used to separate between the high-voltage output terminal and the first connection terminal. The voltage at the location of the first connection terminal is higher than the voltage at the location of the second connection terminal, and the first load R1 is used to separate between the first connection terminal and the second connection terminal. The voltage at the location of the second connection terminal is higher than the voltage at the location of the third connection terminal, and the second load R2 is used to separate between the second connection terminal and the third connection terminal. The voltage at the location of the third connection terminal is higher than the voltage at the location of the fourth connection terminal, and the third load R3 is used to separate between the third connection terminal and the fourth connection terminal. The voltage at the location of the fourth connection terminal is higher than the voltage at the low-voltage input terminal, and the fifth load R5 is used to separate between the fourth connection terminal and the low-voltage input terminal; the first connection terminal is the first differential signal input terminal of the load series circuit unit, the fourth connection terminal is the second differential signal input terminal of the load series circuit unit, the second connection terminal is the first voltage division supply terminal of the load series circuit unit, and the third connection terminal is the second voltage division supply terminal of the load series circuit unit.

[0013] Preferably, the follower-type voltage supply single module includes: a voltage-dividing supply unit, a follower U3, and a resistor R7. The input end of the voltage-dividing supply unit is connected to the third voltage output end of the total power supply module. The output end of the voltage-dividing supply unit is connected to the non-inverting input end of the follower U3. The inverting input end of the follower U3 is connected to the output end of the follower U3. The output end of the follower U3 is connected to one end of the resistor R7, and the other end of the resistor R7 is the output end of the follower-type voltage supply single module.

[0014] Preferably, the voltage-dividing supply unit includes: a resistor R8 and a resistor R9. The first end of the resistor R8 is the input end of the voltage-dividing supply unit. The second end of the resistor R8 is grounded through the resistor R9, and the second end of the resistor R8 is the output end of the voltage-dividing supply unit.

[0015] Preferably, the third amplification module includes: an amplifier U4 and a resistor R6. The non-inverting input end of the amplifier U4 is the reference voltage end of the third amplification module. The inverting input end of the amplifier U4 is the input end of the third amplification module. The inverting input end of the amplifier U4 is connected to one end of the resistor R6, and the other end of the resistor R6 is connected to the output end of the amplifier U4. The output end of the amplifier U4 is the output end of the third amplification module.

[0016] Preferably, both the first amplification module and the second amplification module include: a first voltage stabilization unit, a first amplification unit, a second amplification unit, and a second voltage stabilization unit. The input end of the first voltage stabilization unit is the input end of the first amplification module or the second amplification module. The output end of the first amplification module is connected to the input end of the first amplification unit. The output end of the first amplification unit is connected to the input end of the second amplification unit. The output end of the first amplification unit is connected to the input end of the second voltage stabilization unit. The output end of the second voltage stabilization unit is the output end of the first amplification module or the second amplification module.

[0017] Compared with the prior art, the utility model has the following beneficial effects:

[0018] In this application, first, the first amplification module and the second amplification module are used to process the outputs of the first pressure sensor and the second pressure sensor, so that the subsequent supply air pressure signal can be recognized. In the differential processing module, the load series circuit unit is powered by the follower voltage supply module and is connected not only to the inverting input terminals of the first differential amplifier U1 and the second differential amplifier U2, but also to the output terminals of the first differential amplifier U1 and the second differential amplifier U2 to raise the voltage and avoid the influence of negative voltage output on the output of the third amplification module. Multiple loads in the load series circuit unit are connected in series to form a first power connection terminal, a second wiring terminal, a third wiring terminal, and a fourth wiring terminal. The first power connection terminal, the second wiring terminal, the third wiring terminal, and the fourth wiring terminal are isolated from each other through the loads, without affecting each other, thus laying a foundation for the connection of the first differential amplifier U1 and the second differential amplifier U2. In this application, the first pressure sensor and the second pressure sensor are used to detect the supply air pressure simultaneously, and two detected differential signals are obtained through the differential processing module. The differential signals are used to correct the detection result of the first pressure sensor. This correction method is a prior art. Only the circuit diagram is protected here, thereby improving the accuracy of the detection result.

[0019] Other advantages, objectives, and features of the present utility model will be partially reflected by the following description and partially understood by those skilled in the art through the research and practice of the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a circuit diagram of the first amplification module or the second amplification module in the breathing machine flow signal detection circuit.

[0021] Figure 2 It is a circuit diagram of the differential processing module in the breathing machine flow signal detection circuit. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] In order to make the technical means, creative features, achieved objectives, and functions of the present utility model clearer and easier to understand, the present utility model will be further described below in conjunction with the drawings and specific embodiments:

[0023] As Figure 1 and Figure 2 , shown, the present utility model discloses a breathing machine flow signal detection circuit, including: a first pressure sensor, a second pressure sensor, a first amplification module, a second amplification module, a differential processing module, a follower voltage supply module, a third amplification module, and a total voltage supply module;

[0024] The first pressure sensor and the second pressure sensor are both installed at the air outlet of the ventilator, and both the first pressure sensor and the second pressure sensor are used to detect the air supply pressure at the air outlet; the output end of the first pressure sensor is connected to the input end of the first amplification module, and the output end of the second pressure sensor is connected to the input end of the second amplification module;

[0025] The differential processing module includes: a first differential amplifier U1, a second differential amplifier U2, and a load series circuit unit. The non-inverting input terminal of the first differential amplifier U1 is connected to the output end of the first amplification module, and the non-inverting input terminal of the second differential amplifier U2 is connected to the output end of the second amplification module;

[0026] The total power supply module is provided with a first voltage output terminal, a second voltage output terminal, and a third voltage output terminal. The first voltage output terminal and the second voltage output terminal supply power to the third amplification module, the first differential amplifier U1, and the second differential amplifier U2, and the third voltage output terminal is connected to the input end of the follower voltage supply module;

[0027] The load series circuit unit is provided with a first differential signal input terminal, a second differential signal input terminal, a first voltage dividing supply terminal, and a second voltage dividing supply terminal. The first differential signal input terminal is connected to the output end of the first differential amplifier U1, the second differential signal input terminal is connected to the output end of the second differential amplifier U2, the first voltage dividing supply terminal is connected to the non-inverting input terminal of the first differential amplifier U1, and the first voltage dividing supply terminal is connected to the non-inverting input terminal of the second differential amplifier U2;

[0028] One end of the load series circuit unit is a low-voltage input terminal, and the other end of the load series circuit unit is a high-voltage output terminal; the high-voltage output terminal of the load series circuit unit is the output end of the differential processing module, the output end of the differential processing module is connected to the input end of the third amplification module, and the output end of the follower voltage supply module supplies power to the reference voltage terminal of the third amplification module and the low-voltage input terminal of the load series circuit unit.

[0029] The VIN pins of the first pressure sensor and the second pressure sensor are connected to the voltage, and the VOUT pin of the first pressure sensor and the VOUT pin of the second pressure sensor are respectively the output ends of the first pressure sensor and the second pressure sensor.

[0030] The load series circuit unit includes: a first load R1, a second load R2, a third load R3, a fourth load R4, and a fifth load R5. There are a first terminal, a second terminal, a third terminal, and a fourth terminal provided in the middle of the load series circuit unit. The voltage at the location of the first terminal is lower than the voltage of the high-voltage output terminal, and the high-voltage output terminal is separated from the first terminal by the fourth load R4. The voltage at the location of the first terminal is higher than the voltage at the location of the second terminal, and the first terminal and the second terminal are separated by the first load R1. The voltage at the location of the second terminal is higher than the voltage at the location of the third terminal, and the second terminal and the third terminal are separated by the second load R2. The voltage at the location of the third terminal is higher than the voltage at the location of the fourth terminal, and the third terminal and the fourth terminal are separated by the third load R3. The voltage at the location of the fourth terminal is higher than the voltage of the low-voltage input terminal, and the fourth terminal and the low-voltage input terminal are separated by the fifth load R5. The first terminal is the first differential signal input terminal of the load series circuit unit, the fourth terminal is the second differential signal input terminal of the load series circuit unit, the second terminal is the first voltage-dividing supply terminal of the load series circuit unit, and the third terminal is the second voltage-dividing supply terminal of the load series circuit unit. The first load R1, the second load R2, the third load R3, the fourth load R4, and the fifth load R5 are all resistors, realizing isolation between the first terminal, the second terminal, the third terminal, and the fourth terminal through resistors.

[0031] The follower voltage supply single module includes: a voltage-dividing supply unit, a follower U3, and a resistor R7. The input end of the voltage-dividing supply unit is connected to the third voltage output end of the total power supply module, the output end of the voltage-dividing supply unit is connected to the non-inverting input end of the follower U3, the inverting input end of the follower U3 is connected to the output end of the follower U3, the output end of the follower U3 is connected to one end of the resistor R7, and the other end of the resistor R7 is the output end of the follower voltage supply single module. The use of the follower U3 makes the voltage output more stable and reliable.

[0032] The voltage-dividing supply unit includes: a resistor R8 and a resistor R9. The first end of the resistor R8 is the input end of the voltage-dividing supply unit, the second end of the resistor R8 is grounded through the resistor R9, and the second end of the resistor R8 is the output end of the voltage-dividing supply unit. Voltage-dividing output is realized, and the output voltage can be adjusted by adjusting the resistance values of the resistor R8 and the resistor R9.

[0033] The third amplification module includes: an amplifier U4 and a resistor R6. The non-inverting input end of the amplifier U4 is the reference voltage terminal of the third amplification module, the inverting input end of the amplifier U4 is the input end of the third amplification module, the inverting input end of the amplifier U4 is connected to one end of the resistor R6, the other end of the resistor R6 is connected to the output end of the amplifier U4, and the output end of the amplifier U4 is the output end of the third amplification module.

[0034] Both the first amplification module and the second amplification module include: a first voltage stabilization unit, a first amplification unit, a second amplification unit, and a second voltage stabilization unit. The input end of the first voltage stabilization unit is the input end of the first amplification module or the second amplification module. The output end of the first amplification module is connected to the input end of the first amplification unit. The output end of the first amplification unit is connected to the input end of the second amplification unit. The output end of the first amplification unit is connected to the input end of the second voltage stabilization unit. The output end of the second voltage stabilization unit is the output end of the first amplification module or the second amplification module.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A flow signal detection circuit for a ventilator, characterized in that: include: A first pressure sensor, a second pressure sensor, a first amplification module, a second amplification module, a differential processing module, a follower voltage supply module, a third amplification module and a total voltage supply module; The first pressure sensor and the second pressure sensor are both installed at the air outlet of the ventilator, and the first pressure sensor and the second pressure sensor are both used to detect the air supply pressure at the air outlet; the output end of the first pressure sensor is connected to the input end of the first amplification module, and the output end of the second pressure sensor is connected to the input end of the second amplification module; The differential processing module includes: a first differential amplifier U1, a second differential amplifier U2 and a load series circuit unit, wherein the in-phase input terminal of the first differential amplifier U1 is connected to the output terminal of the first amplification module, and the in-phase input terminal of the second differential amplifier U2 is connected to the output terminal of the second amplification module; The main power supply module is provided with a first voltage output terminal, a second voltage output terminal and a third voltage output terminal. The first voltage output terminal and the second voltage output terminal are used to supply power to the third amplification module, the first differential amplifier U1 and the second differential amplifier U2. The third voltage output terminal is connected to the input terminal of the follower voltage supply module. The load series circuit unit is provided with a first differential signal input terminal, a second differential signal input terminal, a first voltage-dividing supply terminal, and a second voltage-dividing supply terminal, the first differential signal input terminal is connected to the output terminal of the first differential amplifier U1, the second differential signal input terminal is connected to the output terminal of the second differential amplifier U2, the first voltage-dividing supply terminal is connected to the non-inverting input terminal of the first differential amplifier U1, and the first voltage-dividing supply terminal is connected to the non-inverting input terminal of the second differential amplifier U2; One end of the load series circuit unit is a low voltage input end, and the other end of the load series circuit unit is a high voltage output end; the high voltage output end of the load series circuit unit is the output end of the differential processing module, the output end of the differential processing module is connected to the input end of the third amplification module, and the output end of the follower voltage supply module supplies power to the reference voltage end of the third amplification module and the low voltage input end of the load series circuit unit.

2. The flow signal detection circuit for a ventilator according to claim 1, characterized in that: The load series circuit unit includes: a first load R1, a second load R2, a third load R3, a fourth load R4 and a fifth load R5. The load series circuit unit is provided with a first terminal, a second terminal, a third terminal and a fourth terminal in the middle. The voltage at the first terminal is lower than the voltage at the high-voltage output terminal. The high-voltage output terminal and the first terminal are separated by the fourth load R4. The voltage at the first terminal is higher than the voltage at the second terminal. The first terminal and the second terminal are separated by the first load R1. The voltage at the second terminal is higher than the voltage at the third terminal. The second terminal is The first terminal is separated from the third terminal by a second load R2, the voltage at the third terminal is higher than the voltage at the fourth terminal, the third terminal and the fourth terminal are separated by a third load R3, the voltage at the fourth terminal is higher than the voltage of the low-voltage input terminal, and the fourth terminal and the low-voltage input terminal are separated by a fifth load R5; the first terminal is the first differential signal input terminal of the load series circuit unit, the fourth terminal is the second differential signal input terminal of the load series circuit unit, the second terminal is the first voltage-dividing supply terminal of the load series circuit unit, and the third terminal is the second voltage-dividing supply terminal of the load series circuit unit.

3. The flow signal detection circuit for a ventilator according to claim 1, characterized in that: The follower type voltage supply single module includes: a voltage divider supply unit, a follower U3 and a resistor R7. The input end of the voltage divider supply unit is connected to the third voltage output end of the main power supply module, the output end of the voltage divider supply unit is connected to the same phase input end of the follower U3, the inverting input end of the follower U3 is connected to the output end of the follower U3, the output end of the follower U3 is connected to one end of the resistor R7, and the other end of the resistor R7 is the output end of the follower type voltage supply single module.

4. The flow signal detection circuit for a ventilator according to claim 3, characterized in that: The voltage division supply unit includes: a resistor R8 and a resistor R9, wherein a first end of the resistor R8 is an input end of the voltage division supply unit, a second end of the resistor R8 is grounded through the resistor R9, and a second end of the resistor R8 is an output end of the voltage division supply unit.

5. The flow signal detection circuit for a ventilator according to claim 1, characterized in that: The third amplifying module includes: an amplifier U4 and a resistor R6, the non-inverting input terminal of the amplifier U4 is the reference voltage terminal of the third amplifying module, the inverting input terminal of the amplifier U4 is the input terminal of the third amplifying module, the inverting input terminal of the amplifier U4 is connected to one end of the resistor R6, the other end of the resistor R6 is connected to the output terminal of the amplifier U4, and the output terminal of the amplifier U4 is the output terminal of the third amplifying module.

6. The flow signal detection circuit for a ventilator according to claim 3, characterized in that: The first amplifying module and the second amplifying module both include: a first voltage stabilizing unit, a first amplifying unit, a second amplifying unit and a second voltage stabilizing unit, the input end of the first voltage stabilizing unit is the input end of the first amplifying module or the second amplifying module, the output end of the first amplifying module is connected to the input end of the first amplifying unit, the output end of the first amplifying unit is connected to the input end of the second amplifying unit, the output end of the first amplifying unit is connected to the input end of the second amplifying unit, and the output end of the second voltage stabilizing unit is the output end of the first amplifying module or the second amplifying module.

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