Breathing machine expiration control gas circuit and control method

Abstract

The invention relates to the technical field of breathing machines, and discloses a breathing machine expiration control gas circuit and a control method.The breathing machine expiration control gas circuit comprises an expiration gas circuit, an airflow generation gas circuit and an overflow pressure control gas circuit, one end of the expiration gas circuit is connected with an expiration opening of a ventilation gas circuit, and the other end of the expiration gas circuit selectively communicates with the gas outlet side of an inspiration control part and one end of the overflow pressure control gas circuit; one end of the airflow generation air path is selectively communicated with the air inlet side of the air suction control part and the outside atmosphere, the other end of the airflow generation air path is selectively communicated with the air outlet side of the air suction control part and one end of the overflow pressure control air path, and the other end of the overflow pressure control air path is communicated with the outside atmosphere. In a ventilation and expiration phase, expiration air pressure can be controlled, positive end-expiration pressure is realized, and zero oxygen consumption during working is realized; in the ventilation and inspiration phase, inspiration airflow or inspiration air pressure is locked, the characteristic of constant airway pressure is achieved, and the ventilation stability is guaranteed; and when the air suction control part breaks down, the airflow generation air path serves as a standby for ventilation, and the use safety is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of ventilators, and more particularly to an exhalation control air circuit and a control method for a ventilator. Background Art

[0002] Existing ventilators are generally positive pressure ventilation ventilators, which are usually equipped with an exhalation control air circuit. The exhalation control air circuit usually consists of a control unit that works in conjunction with the positive pressure ventilation air circuit, an execution terminal exhalation valve, and connecting pipelines.

[0003] The main functions of the expiratory control airway are:

[0004] During the positive pressure inspiratory phase, the inspiratory airflow is locked or pressure-limited to prevent airflow at normal ventilation pressure from being discharged from the expiratory channel. This can be either airflow locking, where all airflow flows into the patient, or pressure limiting, where airflow at a preset pressure flows into the patient and is discharged if it exceeds the preset pressure. The latter is more adaptable to ventilation function development and is safer, ensuring constant airway pressure characteristics and controlling pressure while meeting the patient's re-inspiratory needs.

[0005] During the patient's exhalation phase, the patient's exhalation airflow flows out smoothly through the exhalation control system. It usually comes with an additional exhalation pressure control function, which can generate positive end-expiratory pressure (PEEP). This function allows doctors to set it according to the patient's condition to avoid the collapse of some patients' alveoli during exhalation, or to avoid the closure of some patients' airways during exhalation, or to avoid the patient's respiratory organs working in a state of poor compliance, etc.

[0006] Common exhalation control methods include: passive pneumatic exhalation control device, controllable pneumatic exhalation control device and controllable electromagnetic exhalation control device;

[0007] Passive pneumatic exhalation control mode utilizes the changes in positive pressure during the inspiratory and expiratory phases during ventilation, and through the structural valve membrane design, it can complete the functions of inspiratory locking and expiratory opening;

[0008] There are two common methods of controllable pneumatic exhalation control. One method usually uses the oxygen source used with the ventilator as the control power. By controlling the oxygen flow rate, the pressure is taken from the front end of a specially designed overflow port to control the exhalation valve. The other method is to introduce the ventilation main turbine pressure into the exhalation valve through the air path design in the turbine ventilator to achieve the effect of pressure control.

[0009] The controllable electromagnetic exhalation control method uses electromagnetic force to generate the set inhalation and exhalation locking pressure, and the pressure is controlled by the current.

[0010] The above-mentioned exhalation control methods also have the following disadvantages:

[0011] Passive pneumatic exhalation control, although simple in structure and low in cost, has a single function and is currently mainly used in artificial ventilation devices and simpler ventilators, and cannot meet the ventilation setting and monitoring requirements of more breaths;

[0012] Controllable pneumatic exhalation control by controlling oxygen is comprehensive, but has many structural components and is limited by the oxygen source, which increases oxygen consumption. In certain scenarios, medical oxygen is scarce, and ventilators are used in scenarios without a central oxygen supply, so their shortcomings are particularly prominent.

[0013] By utilizing the controllable pneumatic exhalation control method of the main ventilation turbine, it can be used in the absence of an oxygen source and has a simple structure. However, since the main ventilation turbine cannot control the air flow and pressure at the same time, this method is difficult to solve the problem of following the patient's active inhalation needs while performing pressure-controlled ventilation, that is, to achieve the characteristic of ensuring constant airway pressure.

[0014] The controllable electromagnetic exhalation control method not only solves the oxygen consumption problem, but also ensures constant airway pressure characteristics; however, compared with the pneumatic method, its waterproof requirements and cleaning conditions are usually more stringent, and it requires the design of a complex and precise structure to achieve it; moreover, the technical characteristics of electromagnetic control usually require the moving parts to be placed inside the ventilator, which increases its complexity and reduces its reliability to prevent contamination of the exhaled air; at the same time, it generally increases the size of the ventilator host, which is not conducive to the transfer of the ventilator.

[0015] Therefore, it is necessary to propose a ventilator exhalation control air circuit and control method to at least partially solve the problems existing in the prior art. Summary of the Invention

[0016] The Summary of the Invention introduces a series of simplified concepts that will be further described in the Detailed Description of the Invention. The Summary of the Invention is not intended to limit the key features and essential features of the claimed technical solution, nor is it intended to determine the scope of protection of the claimed technical solution.

[0017] In order to at least partially solve the above problems, the present invention provides an exhalation control air circuit of a ventilator, comprising: an exhalation air circuit, an airflow generating air circuit and an overflow pressure control air circuit, one end of the exhalation air circuit is connected to the exhalation port of the ventilation air circuit, and the other end thereof is selectively connected to the air outlet side of the inhalation control part and one end of the overflow pressure control air circuit; one end of the airflow generating air circuit is selectively connected to the air inlet side of the inhalation control part and the outside atmosphere, and the other end thereof is selectively connected to the air outlet side of the inhalation control part and one end of the overflow pressure control air circuit, and the other end of the overflow pressure control air circuit is connected to the outside atmosphere.

[0018] Preferably, the airflow generating air circuit includes: an airflow generator, whose air inlet is connected to the air inlet side of the air intake control unit and the outside atmosphere through a first selection switch, and whose air outlet is connected to the air outlet side of the air intake control unit and one end of the overflow pressure control air circuit through a second selection switch.

[0019] Preferably, the airflow generator is one of a turbine, a fan, a peristaltic pump, a reciprocating cylinder pump or a gear pump.

[0020] Preferably, the exhalation air circuit includes: a first control valve, a first throttle valve, a first air pressure sensor, a safety control valve and an exhalation valve connected in sequence; the exhalation valve is connected to the exhalation port of the ventilation air circuit, and the first control valve is respectively connected to the outlet side of the inhalation control part and one end of the overflow pressure control air circuit.

[0021] Preferably, the overflow pressure control air circuit includes: a second throttle valve, one end of which is connected to the exhalation air circuit and the airflow generation air circuit respectively, and the other end is connected to the external atmosphere.

[0022] A method for controlling an exhalation control airway of a ventilator, comprising:

[0023] During the inspiratory phase of ventilation, the system switches to the inspiratory flow lock mode or the inspiratory pressure lock mode to provide inspiratory airflow for the patient during the inspiratory phase;

[0024] During the expiratory phase of ventilation, switch to the expiratory pressure control mode to achieve positive end-expiratory pressure during the patient's exhalation phase.

[0025] Preferably, when it is necessary to switch to the inspiratory flow lock mode during the ventilation and inspiration phase, one end of the expiratory air path is connected to the expiratory port of the ventilation air path, and the other end is connected to the outlet side of the inspiratory control unit.

[0026] Preferably, during the ventilation and inhalation phase, when it is necessary to switch to the inhalation pressure locking mode, one end of the expiratory air circuit is connected to the expiratory port of the ventilation air circuit, and the other end is connected to the overflow pressure control air circuit, and one end of the airflow generating air circuit is connected to the outside atmosphere, and the other end is connected to the overflow pressure control air circuit.

[0027] Preferably, during the ventilation and exhalation phase, when it is necessary to switch to the exhalation pressure control mode, one end of the exhalation air circuit is connected to the exhalation port of the ventilation air circuit, and the other end is connected to the overflow pressure control air circuit, and one end of the airflow generating air circuit is connected to the outside atmosphere, and the other end is connected to the overflow pressure control air circuit to achieve positive end-expiratory pressure.

[0028] Preferably, when a failure occurs in the intake control unit, one end of the airflow generating air path is connected to the air inlet side of the intake control unit, and the other end is connected to the air outlet side of the intake control unit, and one end of the exhalation air path is connected to the exhalation port of the ventilation air path, and the other end is selectively connected to the air outlet side of the intake control unit or one end of the overflow pressure control air path.

[0029] Compared with the prior art, the present invention has at least the following beneficial effects:

[0030] The ventilator exhalation control air circuit and control method described in the present invention can control the expiratory air pressure during the expiratory phase of ventilation, achieve positive end-expiratory pressure, and work with zero oxygen consumption; during the inspiratory phase of ventilation, it can achieve inspiratory airflow locking or inspiratory air pressure locking, and can achieve the characteristic of ensuring constant airway pressure, thereby ensuring the stability of ventilation for the patient; when a failure occurs in the inspiratory control part, ventilation can also be carried out through the airflow generating air circuit as a backup air circuit, thereby ensuring the safety of the ventilator and buying time for medical staff to deal with the problem.

[0031] The ventilator exhalation control airway and control method described in the present invention, as well as other advantages, objectives and features of the present invention will be partially reflected in the following description, and will also be partially understood by technicians in this field through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0033] Figure 1 This is a schematic structural diagram of the exhalation control air circuit of the ventilator according to the present invention;

[0034] Figure 2 Schematic diagram of the airway structure of the ventilator exhalation control airway in the inspiratory airflow locking mode during the ventilation and inspiratory phases of the present invention;

[0035] Figure 3 This is a schematic diagram of the airway structure of the ventilator's exhalation control airway in the inspiratory air pressure lock mode during the ventilation and inspiratory phases of the present invention;

[0036] Figure 4 Schematic diagram of the airway structure of the ventilator exhalation control airway in the ventilation and exhalation phases under the exhalation pressure control mode;

[0037] Figure 5 This is a structural diagram of the ventilator according to the present invention, in which the airflow generating air circuit is used as a backup air circuit when a failure occurs in the inhalation control part of the exhalation control air circuit;

[0038] Figure 6 The present invention is a flowchart of the method for controlling the exhalation control air circuit of the ventilator. DETAILED DESCRIPTION

[0039] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments so that those skilled in the art can implement the invention with reference to the description.

[0040] It should be understood that terms such as “having”, “including” and “comprising” used herein do not preclude the existence or addition of one or more other elements or combinations thereof.

[0041] like Figure 1 As shown, the present invention provides an exhalation control air circuit of a ventilator, comprising: an exhalation air circuit 1, an airflow generating air circuit 2 and an overflow pressure control air circuit 3, one end of the exhalation air circuit 1 is connected to the exhalation port 41 of the ventilation air circuit 4, and the other end thereof is selectively connected to the air outlet side of the inhalation control part 53 and one end of the overflow pressure control air circuit 3; one end of the airflow generating air circuit 2 is selectively connected to the air inlet side of the inhalation control part 53 and the outside atmosphere 6, and the other end thereof is selectively connected to the air outlet side of the inhalation control part 53 and one end of the overflow pressure control air circuit 3, and the other end of the overflow pressure control air circuit 3 is connected to the outside atmosphere 6.

[0042] Among them, the inhalation port 42 of the ventilation air circuit 4 is connected to the inhalation control air circuit 5, the exhalation port 41 of the ventilation air circuit 4 is connected to the exhalation control air circuit, and the ventilator port 43 of the ventilation air circuit 4 is used for patient ventilation; the ventilation air circuit 4 has three connection ports, namely the inhalation port 42, the exhalation port 41 and the ventilator port 43; the ventilator port 43 is connected to one of a mask, an endotracheal cannula, a nasal oxygen tube, a breathing hood or a breathing nasal mask; the air circuit where the ventilator port 43 is located is also provided with a proximal pressure sensor, a proximal flow sensor and an end-tidal carbon dioxide detector near the patient;

[0043] The inhalation control air circuit 5 includes: a ventilation air source 51, a ventilation control module 52, an inhalation control unit 53, a safety valve 54, a ventilation monitoring sensor 55, a ventilation check valve 56 and a ventilation filter 57 connected in sequence. The ventilation filter 57 is connected to the inhalation port 42 of the ventilation air circuit 4; the safety valve 54 can form a passage in the event of an unexpected power outage, allowing the patient to inhale unimpeded.

[0044] The air intake control unit 53 uses a turbine, and the ventilation monitoring sensor 55 includes one or more combinations of a flow sensor, a pressure sensor, and a gas concentration sensor. The gas concentration sensor includes at least an oxygen concentration sensor and a carbon dioxide concentration sensor.

[0045] During the inspiratory phase of ventilation, the inspiratory flow lock mode or the inspiratory pressure lock mode can be selected to prevent the airflow of normal ventilation pressure from being discharged from the expiratory airway 1; during the expiratory phase of ventilation, the expiratory pressure control mode is used to achieve positive end-expiratory pressure.

[0046] like Figure 2As shown, when the inhalation flow lock mode is selected, one end of the exhalation path 1 is connected to the exhalation port 41 of the ventilation path 4, and the other end is connected to the outlet side of the inhalation control unit 53, that is, Figure 2 In the solid line portion shown in FIG, there is no airflow in the airflow generation airway 2, and all airflow in the inspiratory control airway 5 flows to the patient, preventing the airflow of normal ventilation pressure from being discharged from the expiratory airway 1;

[0047] like Figure 3 As shown, when the inhalation pressure lock mode is selected, one end of the exhalation air path 1 is connected to the exhalation port 41 of the ventilation air path 4, and the other end thereof is connected to the overflow pressure control air path 3. One end of the airflow generating air path 2 is connected to the outside atmosphere 6, and the other end thereof is connected to the overflow pressure control air path 3, that is, Figure 3 In the solid line portion shown, the inhalation control air circuit 5 provides the patient with an airflow of a preset pressure. If the airflow pressure provided to the patient exceeds the preset pressure, the airflow will pass through the expiratory air circuit 1 and be discharged from the overflow pressure control air circuit 3. If the airflow pressure provided to the patient is less than the preset pressure due to the airflow discharged from the expiratory air circuit 1 and the overflow pressure control air circuit 3, the flow rate of the gas discharged from the overflow pressure control air circuit 3 is adjusted (for example, the corresponding throttle valve opening is adjusted), or a low-pressure airflow is provided to the expiratory air circuit 1 through the airflow generating air circuit 2 (the pressure of the low-pressure airflow is less than or equal to the pressure of the airflow discharged from the expiratory air circuit 1) to reduce or prevent the gas from being discharged from the overflow pressure control air circuit 3, thereby ensuring that the airflow pressure provided to the patient is maintained at the preset pressure, ensuring a constant airway pressure, and improving the stability of the air supply to the patient.

[0048] like Figure 4 As shown, during the ventilation and exhalation phase, the exhalation pressure control mode is adopted, one end of the exhalation air circuit 1 is connected to the exhalation port 41 of the ventilation air circuit 4, and the other end thereof is connected to the overflow pressure control air circuit 3, one end of the airflow generating air circuit 2 is connected to the outside atmosphere 6, and the other end thereof is connected to the overflow pressure control air circuit 3, that is, Figure 4 Solid line portion shown; at the end of exhalation, a low-pressure airflow is generated through the airflow generating air circuit 2, a part of the airflow will be discharged from the overflow pressure control air circuit 3, and a part of the airflow is used to maintain the pressure of the expiratory air circuit 1 at the set pressure to achieve positive end-expiratory pressure. The pressure provided by the airflow generating air circuit 2 to the expiratory air circuit 1 is controlled by adjusting the airflow flow discharged from the overflow pressure control air circuit 3 or the airflow flow generated by the airflow generating air circuit 2 to achieve positive end-expiratory pressure.

[0049] When the inhalation control unit 53 fails and cannot provide airflow to the patient, the airflow generating gas path 2 is used as a backup gas path;

[0050] During the inspiratory phase of ventilation, Figure 5As shown, the switch is made so that one end of the airflow generating path 2 is connected to the air inlet side of the inhalation control unit 53, and the other end thereof is connected to the air outlet side of the inhalation control unit 53, and one end of the exhalation path 1 is connected to the exhalation port 41 of the ventilation path 4, and the other end thereof is connected to the air outlet side of the inhalation control unit 53, that is, Figure 5 In the solid line portion shown, the inhalation control unit 53 is bypassed, and airflow is provided through the airflow generating air path 2. The ventilation air source 51 sequentially passes through the ventilation control module 52, the airflow generating air path 2, the safety valve 54, the ventilation monitoring sensor 55, the ventilation one-way valve 56 and the ventilation filter 57, thereby achieving an inhalation airflow locking mode, that is, all airflow flows to the patient, thereby providing air to the patient.

[0051] During the ventilatory and expiratory phases, Figure 4 As shown, the exhalation pressure control mode can still be used. One end of the exhalation air circuit 1 is connected to the exhalation port 41 of the ventilation air circuit 4, and the other end is connected to the overflow pressure control air circuit 3. One end of the airflow generating air circuit 2 is connected to the outside atmosphere 6, and the other end is connected to the overflow pressure control air circuit 3, that is, Figure 4 The solid line portion is shown.

[0052] Through the above-mentioned air circuit design, during the expiratory phase of ventilation, expiratory pressure control can be performed, positive end-expiratory pressure is achieved, and zero oxygen consumption is achieved; during the inspiratory phase of ventilation, inspiratory airflow locking or inspiratory pressure locking can be achieved, and the characteristic of ensuring constant airway pressure can be achieved, thereby ensuring the stability of ventilation for the patient; when the inspiratory control unit 53 fails, ventilation can also be performed through the airflow generating air circuit 2 as a backup air circuit, thereby ensuring the safety of the ventilator and buying time for medical staff to deal with it.

[0053] like Figure 1 As shown, in one embodiment, the airflow generating air circuit 2 includes: an airflow generator 21, whose air inlet is connected to the air inlet side of the air intake control unit 53 and the external atmosphere 6 through a first selection switch 22, and whose air outlet is connected to the air outlet side of the air intake control unit 53 and one end of the overflow pressure control air circuit 3 through a second selection switch 23.

[0054] Furthermore, the airflow generator 21 is one of a turbine, a fan, a peristaltic pump, a reciprocating cylinder pump or a gear pump.

[0055] The first selection switch 22 and the second selection switch 23 both adopt large-flow two-position three-way valves. Through the first selection switch 22, one end of the airflow generator 21 can be connected to the outside atmosphere 6 or to the air intake side of the air intake control unit 53. Through the second selection switch 23, the other end of the airflow generator 21 can be connected to the air outlet side of the air intake control unit 53 or to the overflow pressure control air path 3.

[0056] like Figure 1As shown, in one embodiment, the exhalation air circuit 1 includes: a first control valve 11, a first throttle valve 12, a first air pressure sensor 13, a safety control valve 14 and an exhalation valve 15 connected in sequence; the exhalation valve 15 is connected to the exhalation port 41 of the ventilation air circuit 4, and the first control valve 11 is respectively connected to the outlet side of the inhalation control part 53 and one end of the overflow pressure control air circuit 3.

[0057] The first control valve 11 and the safety control valve 14 are both two-position three-way valves. One end of the safety control valve 14 is connected to the outside atmosphere 6 . The exhalation valve 15 is a diaphragm valve.

[0058] The first throttle valve 12 is used to adjust the air flow rate of the expiratory air circuit 1, the first air pressure sensor 13 is used to monitor the air pressure of the expiratory air circuit 1, and the safety control valve 14 can switch to connect with the outside atmosphere 6 in the event of an accidental power outage, thereby ensuring that the patient can exhale. The expiratory valve 15 is connected to the exhalation port 41 to ensure that the patient can exhale; the first control valve 11 can connect the other end of the expiratory air circuit 1 with the outlet side of the inhalation control part 53, or connect the other end of the expiratory air circuit 1 with the overflow pressure control air circuit 3.

[0059] like Figure 1 As shown, in one embodiment, the overflow pressure control air circuit 3 includes: a second throttle valve 31, one end of which is connected to the exhalation air circuit 1 and the airflow generating air circuit 2 respectively, and the other end is connected to the external atmosphere 6.

[0060] The second throttle valve 31 is used to adjust the airflow rate discharged from the overflow pressure control air circuit 3 so that the airway pressure during inspiration or exhalation can be adjusted through the overflow pressure control air circuit 3 to ensure the stability and safety of ventilation for the patient.

[0061] like Figure 6 As shown, the present invention also provides a method for controlling an exhalation control airway of a ventilator, comprising:

[0062] During the inspiratory phase of ventilation, the system switches to the inspiratory flow lock mode or the inspiratory pressure lock mode to provide inspiratory airflow for the patient during the inspiratory phase;

[0063] During the expiratory phase of ventilation, switch to the expiratory pressure control mode to achieve positive end-expiratory pressure during the patient's exhalation phase.

[0064] When starting ventilation, you can select the inspiratory flow lock mode or the inspiratory pressure lock mode, and then perform inspiratory phase control to maintain a constant airway pressure. Then, when entering the expiratory phase, switch to the expiratory pressure control mode and perform expiratory phase control to achieve positive end-expiratory pressure. When the patient needs to continue ventilation, ventilate the patient in this cycle. When the patient no longer needs ventilation, stop ventilation.

[0065] like Figure 2As shown, further, in the ventilation and inspiration phase, when it is necessary to switch to the inspiratory flow locking mode, one end of the expiratory air path 1 is connected to the expiratory port 41 of the ventilation air path 4, and the other end is connected to the outlet side of the inspiratory control unit 53.

[0066] like Figure 3 As shown, further, in the ventilation and inhalation phase, when it is necessary to switch to the inhalation air pressure locking mode, one end of the expiratory air circuit 1 is connected to the expiratory port 41 of the ventilation air circuit 4, and the other end thereof is connected to the overflow pressure control air circuit 3, and one end of the airflow generating air circuit 2 is connected to the external atmosphere 6, and the other end thereof is connected to the overflow pressure control air circuit 3.

[0067] like Figure 4 As shown, further, in the ventilation and exhalation phase, when it is necessary to switch to the expiratory pressure control mode, one end of the expiratory air circuit 1 is connected to the expiratory port 41 of the ventilation air circuit 4, and the other end thereof is connected to the overflow pressure control air circuit 3, and one end of the airflow generating air circuit 2 is connected to the external atmosphere 6, and the other end thereof is connected to the overflow pressure control air circuit 3 to achieve positive end-expiratory pressure.

[0068] Through the above control method, the selection of inspiratory airflow locking mode and inspiratory pressure locking mode can be realized during the inspiratory phase, the appropriate inspiratory mode can be selected, and the characteristics of constant airway pressure can be guaranteed to ensure the stability of patient ventilation; during the expiratory phase, it can switch to the expiratory pressure control mode, perform expiratory pressure control, achieve positive end-expiratory pressure, and work with zero oxygen consumption.

[0069] In one embodiment, when a failure occurs in the inhalation control unit 53, one end of the airflow generating air path 2 is connected to the air inlet side of the inhalation control unit 53, and the other end thereof is connected to the air outlet side of the inhalation control unit 53; one end of the exhalation air path 1 is connected to the exhalation port 41 of the ventilation air path 4, and the other end thereof is selectively connected to the air outlet side of the inhalation control unit 53 or one end of the overflow pressure control air path 3.

[0070] When the air intake control unit 53 fails, the air intake control air path 5 cannot actively generate airflow, and the airflow generating air path 2 is used as a backup air path to generate airflow. Figure 5 As shown, the power for generating airflow is provided by the airflow generating air circuit 2, and the ventilation air source 51 sequentially passes through the ventilation control module 52, the airflow generating air circuit 2, the safety valve 54, the ventilation monitoring sensor 55, the ventilation one-way valve 56 and the ventilation filter 57 to reach the inhalation port 42, thereby ventilating the patient and realizing the inhalation airflow locking mode; in the expiratory phase, as shown in FIG. Figure 4 As shown, positive end-expiratory pressure can be achieved through the airflow generating air path 2;

[0071] Through the above design, when the inhalation control unit 53 fails, the airflow generating circuit 2 can be used to temporarily ventilate the patient, ensuring the safety of the ventilator and buying time for medical staff to deal with the problem.

[0072] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0073] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0074] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with this field, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the present invention, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. A ventilator exhalation control air circuit, characterized in that: include: An exhalation air circuit (1), an airflow generating air circuit (2) and an overflow pressure control air circuit (3), wherein one end of the exhalation air circuit (1) is connected to the exhalation port (41) of the ventilation air circuit (4), and the other end thereof is selectively connected to the air outlet side of the inhalation control unit (53) and one end of the overflow pressure control air circuit (3); one end of the airflow generating air circuit (2) is selectively connected to the air inlet side of the inhalation control unit (53) and the outside atmosphere (6), and the other end thereof is selectively connected to the air outlet side of the inhalation control unit (53) and one end of the overflow pressure control air circuit (3), and the other end of the overflow pressure control air circuit (3) is connected to the outside atmosphere (6).

2. The ventilator exhalation control air circuit according to claim 1, characterized in that: The airflow generating air circuit (2) comprises an airflow generator (21), an air inlet of which is connected to the air inlet side of the air intake control unit (53) and the outside atmosphere (6) via a first selection switch (22), and an air outlet of which is connected to the air outlet side of the air intake control unit (53) and one end of the overflow pressure control air circuit (3) via a second selection switch (23).

3. The ventilator exhalation control air circuit according to claim 2, characterized in that: The airflow generator (21) is one of a turbine, a fan, a peristaltic pump, a reciprocating cylinder pump or a gear pump.

4. The ventilator exhalation control air circuit according to claim 1, characterized in that: The exhalation air circuit (1) comprises: a first control valve (11), a first throttle valve (12), a first air pressure sensor (13), a safety control valve (14) and an exhalation valve (15) which are connected in sequence; the exhalation valve (15) is connected to the exhalation port (41) of the ventilation air circuit (4), and the first control valve (11) is respectively connected to the outlet side of the inhalation control unit (53) and one end of the overflow pressure control air circuit (3).

5. The ventilator exhalation control air circuit according to claim 1, characterized in that: The overflow pressure control air circuit (3) comprises: a second throttle valve (31), one end of which is respectively connected to the exhalation air circuit (1) and the airflow generation air circuit (2), and the other end is connected to the external atmosphere (6).

6. A method for controlling an exhalation control air circuit of a ventilator, for controlling the exhalation control air circuit of a ventilator according to any one of claims 1 to 5, characterized in that: include: During the inspiratory phase of ventilation, the system switches to the inspiratory flow lock mode or the inspiratory pressure lock mode to provide inspiratory airflow for the patient during the inspiratory phase; During the expiratory phase of ventilation, switch to the expiratory pressure control mode to achieve positive end-expiratory pressure during the patient's exhalation phase.

7. The method for controlling the exhalation control airway of a ventilator according to claim 6, characterized in that: During the ventilation and inspiration phase, when it is necessary to switch to the inspiration flow locking mode, one end of the exhalation air path (1) is connected to the exhalation port (41) of the ventilation air path (4), and the other end is connected to the outlet side of the inspiration control unit (53).

8. The method for controlling the exhalation control airway of a ventilator according to claim 6, characterized in that: During the ventilation and inspiration phase, when it is necessary to switch to the inspiration air pressure locking mode, one end of the exhalation air path (1) is connected to the exhalation port (41) of the ventilation air path (4), and the other end thereof is connected to the overflow pressure control air path (3); one end of the airflow generating air path (2) is connected to the outside atmosphere (6), and the other end thereof is connected to the overflow pressure control air path (3).

9. The method for controlling the exhalation control airway of a ventilator according to claim 6, characterized in that: In the ventilation and exhalation phase, when it is necessary to switch to the exhalation pressure control mode, one end of the exhalation air circuit (1) is connected to the exhalation port (41) of the ventilation air circuit (4), and the other end thereof is connected to the overflow pressure control air circuit (3); one end of the airflow generating air circuit (2) is connected to the outside atmosphere (6), and the other end thereof is connected to the overflow pressure control air circuit (3), thereby achieving positive end-expiratory pressure.

10. The method for controlling the exhalation control airway of a ventilator according to claim 6, characterized in that: When the inhalation control unit (53) fails, one end of the airflow generating air path (2) is connected to the air inlet side of the inhalation control unit (53), and the other end thereof is connected to the air outlet side of the inhalation control unit (53); one end of the exhalation air path (1) is connected to the exhalation port (41) of the ventilation air path (4), and the other end thereof is selectively connected to the air outlet side of the inhalation control unit (53) or one end of the overflow pressure control air path (3).

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