An auxiliary ventilation device for preventing gas embolism using one-lung positive pressure ventilation.

Abstract

This invention discloses an auxiliary ventilation device for one-lung positive pressure ventilation (CPAP) to prevent gas embolism, comprising a gas source connector, a precision flow regulating valve, a pressure generating and display module, and a patient connector. One end of the gas source connector is connected to the inlet of the precision flow regulating valve, and the other end is used to connect to a hospital central oxygen supply or a high-pressure oxygen cylinder. The outlet of the precision flow regulating valve is connected to the inlet of the patient connector, and the outlet of the patient connector can be directly connected to the affected side interface of a single-lumen endotracheal tube or a double-lumen bronchial tube. The pressure generating and display module is installed on the patient connector. This device addresses the problems in existing technologies, such as the lack of dedicated CPAP equipment for gas embolism prevention, the inability to visualize and adjust pressure, and the inability to accurately maintain pressure within a safe and effective pressure window (5~10 cmH2O), thereby achieving active, quantitative, and controllable gas embolism prevention during surgery.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, specifically relating to an auxiliary ventilation device for applying continuous positive airway pressure (CPAP) to the affected lung during thoracic surgery, especially during CT-guided lung puncture, to prevent venous gas embolism. Background Technology

[0002] During CT-guided percutaneous lung biopsy or ablation under general anesthesia, gas embolism is a serious complication with a low incidence (approximately 0.03%–0.1%) but can be fatal (mortality rate as high as 28%). Its core pathological mechanism lies in the fact that positive pressure ventilation causes the alveolar pressure to remain consistently higher than the pulmonary venous pressure. When the puncture needle simultaneously damages the alveolar wall and the wall of adjacent blood vessels, the positive pressure of the ventilator can directly force gas into the pulmonary veins through the needle path, subsequently entering the left ventricular system and systemic circulation, leading to air embolism in the cerebral or coronary arteries.

[0003] Current prevention strategies primarily focus on needle tract occlusion after puncture (such as autologous blood patches or gelatin sponges) to prevent pneumothorax, with very limited proactive preventative measures against intraoperative gas embolism. Studies have shown that applying low-level continuous positive airway pressure (CPAP, such as 5–10 cmH2O) to the affected lung can establish a pressure barrier, eliminating the "siphoning" effect of negative pressure in the pulmonary veins, thereby reducing the risk of gas entering the bloodstream at the source. However, there are currently no CPAP devices specifically designed for this purpose in the operating room. Existing CPAP devices (such as ventilators for home sleep apnea treatment) are bulky, have imprecise pressure control, lack real-time visual pressure feedback, and their primary goal is to improve oxygenation rather than prevent embolism, failing to meet the needs for precise intraoperative adjustment, rapid response, and safe visualization. Some research devices (such as the "Continuous Positive Airway Pressure Device for One-Lung Ventilation Surgery" applied for by Tianjin Medical University General Hospital) involve pressure display and flow regulation, but their design goal is to improve hypoxemia during one-lung ventilation. The pressure range is not focused on the embolism prevention window of 5-10 cmH2O, and they are not optimized for the high-risk scenario of CT-guided puncture.

[0004] Therefore, there is an urgent need for a specialized device that is compact, easy to operate, and capable of accurately setting and displaying CPAP pressure within the range of 5-10 cmH2O in real time, in order to fill the gap in existing technology for the prevention of intraoperative gas embolism. Summary of the Invention

[0005] To address the aforementioned shortcomings in existing technologies, this invention provides an auxiliary ventilation device for CT-guided puncture procedures in thoracic surgery, specifically for preventing gas embolism through single-lung positive pressure ventilation. This device solves the problems of existing technologies, such as the lack of dedicated CPAP equipment for gas embolism prevention, the inability to visualize and adjust pressure, and the inability to precisely maintain pressure within a safe and effective pressure window (5~10 cmH2O). This enables active, quantitative, and controllable gas embolism prevention during surgery.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] An auxiliary ventilation device for preventing gas embolism using one-lung positive pressure ventilation includes a gas source connector, a precision flow regulating valve, a pressure generation and display module, and a patient connector;

[0008] One end of the gas source connector is connected to the air inlet of the precision flow regulating valve, and the other end of the gas source connector is used to connect to the hospital's central oxygen supply or high-pressure oxygen cylinder.

[0009] The outlet of the precision flow regulating valve is connected to the inlet of the patient connector. The outlet of the patient connector can be directly connected to the affected side interface of a single-lumen endotracheal tube or a double-lumen bronchial tube. The pressure generation and display module is installed on the patient connector.

[0010] As a further improvement of the invention, the assisted ventilation device also includes a safety relief valve, which is installed on the patient connector.

[0011] As a further improvement of the present invention, the patient connector is provided with an anti-backflow valve near the single-lumen endotracheal tube or the double-lumen bronchial tube.

[0012] As a further improvement of the present invention, the precision flow regulating valve is selected as a medical needle valve.

[0013] As a further improvement of the present invention, the pressure generation and display module includes a pressure sensor and a display screen. The pressure sensor is installed on the patient connector, and the pressure signal collected by the pressure sensor is input to a microcontroller for processing and then drives the OLED display screen.

[0014] As a further improvement of the present invention, the auxiliary ventilation device also includes a red LED and a buzzer, which are controlled by a microcontroller.

[0015] Compared with the prior art, the present invention has the following technical effects:

[0016] 1. Precise prevention of gas embolism: The CPAP pressure in the affected lung is precisely maintained at 5~10 cmH2O, which can eliminate the "siphon" environment of negative pressure in the pulmonary veins and avoid excessive pressure causing the lung to over-expand and interfere with the surgical operation. It physically blocks the driving force for gas to enter the blood vessels through the puncture needle tract.

[0017] 2. Visualization and controllability: Real-time pressure display allows anesthesiologists to directly observe the actual airway pressure of the affected lung and dynamically adjust the flow rate according to the patient's position, ventilator settings, and puncture risks, avoiding blindly adjusting the flow rate based on experience.

[0018] 3. Easy to operate and compatible with existing equipment: It can be directly connected to the standard oxygen supply and patient breathing circuit without the need to modify the anesthesia machine or ventilator, and can be quickly promoted and applied in the operating room.

[0019] 4. Enhanced safety: Built-in safety relief valve and optional audible and visual alarm function to prevent barotrauma caused by accidental excessive pressure; non-magnetic compatible design adapts to CT room environment.

[0020] 5. Filling a clinical gap: Currently, there are no dedicated CPAP products on the market for the prevention of gas embolism through CT-guided puncture. This device provides a low-cost, efficient, and plug-and-play solution. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of an auxiliary ventilation device for one-lung positive pressure ventilation to prevent gas embolism. Figure 1 ;

[0022] Figure 2 This is a schematic diagram of the structure of an auxiliary ventilation device for one-lung positive pressure ventilation to prevent gas embolism. Figure 2 ;

[0023] Figure 3 This is a control diagram for an auxiliary ventilation device for preventing gas embolism using one-lung positive pressure ventilation.

[0024] In the attached diagram: 1—Gas source connector; 2—Precision flow regulating valve; 3—Pressure generation and display module; 4—Patient connector; 5—Double-lumen bronchial tube; 6—Safety relief valve. Detailed Implementation

[0025] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0026] like Figure 1As shown, a one-lung positive pressure ventilation (POP) auxiliary ventilation device for preventing gas embolism is disclosed. The main body of the device is injection molded from medical-grade polymer material (such as ABS plastic). The device includes a gas source connector 1, a precision flow regulating valve 2, a pressure generation and display module 3, and a patient connector 4. One end of the gas source connector 1 is connected to the inlet of the precision flow regulating valve 2, and the other end of the gas source connector 1 is used to connect to a hospital central oxygen supply or a high-pressure oxygen cylinder. The outlet of the precision flow regulating valve 2 is connected to the inlet of the patient connector 4, and the outlet of the patient connector 4 can be directly connected to the affected side interface of a single-lumen endotracheal tube or a double-lumen bronchial tube 5. The pressure generation and display module 3 is installed on the patient connector 4.

[0027] Example 1

[0028] The gas source connector is a 9 mm diameter, 6% Luer tapered connector, connected to a central oxygen supply (pressure 0.4 MPa). A medical needle valve (maximum flow rate 20 L / min) is used for precision flow control. The valve stem drives a knob with flow rate graduations (2, 4, 6, ..., 20 L / min) engraved on its circumference. After passing through a 6 mm inner diameter, 30 mm long constant flow resistance tube (producing the Bernoulli effect), the pressure and flow rate exhibit an approximately linear relationship.

[0029] A miniature Bourdon tube pressure gauge (range 0~20 cmH2O, accuracy ±0.5 cmH2O) is connected to the patient connector, which is the pressure generation and display module 3. The patient connector is a standard connector with an inner diameter of 15 mm.

[0030] How to use:

[0031] 1) The anesthesiologist connects the bronchial tube interface of the affected lung to the patient connector of this device, and connects the gas source connector to oxygen.

[0032] 2) Adjust the precision flow control valve to the initial flow rate of 8 L / min, observe the pressure gauge reading, and gradually fine-tune until the pressure display stabilizes at 7~8 cmH2O.

[0033] 3) During CT puncture, continuous gas supply is provided. Fluctuations in the pressure gauge indicate whether there is a leak or the patient is coughing. The surgeon should monitor the pressure value in real time and maintain it within 5~10 cmH2O.

[0034] 4) After the puncture is completed, close the precision flow regulating valve and disconnect the device.

[0035] Results: Simulation tests showed that the flow-pressure curve exhibited good linearity within the range of 5~15 L / min (R0). 2 >0.98), pressure gauge response time <1 second, effectively maintains target pressure, and the total weight of the device is <300 g, with no magnetic interference.

[0036] Example 2

[0037] If the precision flow regulating valve in Example 1 does not have a pressure relief function, a safety pressure relief valve 6 can be installed on the patient connector 4. The safety pressure relief valve is a spring-loaded relief valve, and the opening pressure is set to 15 cmH2O. Figure 2 As shown. Typically, the gas pressure on the side of the precision flow control valve is higher than the pressure inside the alveoli. However, to further ensure that the gas does not flow backward and to make the device reusable, an anti-backflow valve can be installed at the patient connector 4 near the single-lumen endotracheal tube or double-lumen bronchial tube 5.

[0038] Example 3

[0039] An electronic module is added based on Embodiments 1 and 2, wherein the pressure generation and display module 3 adopts a pressure sensor and an OLED display screen.

[0040] The pressure sensor is a MEMS silicon piezoresistive sensor (range ±30 cmH2O, accuracy ±0.2 cmH2O). The digital signal is processed by a microcontroller (STM32G030) and then drives an OLED display (0.96 inches). Figure 3 As shown.

[0041] The display shows the current pressure, target pressure setting (adjusted up and down via buttons, with the corresponding flow valve and stepper motor automatically controlling the pressure), and battery level in real time. The precision flow control valve 2 is automatically adjusted via a stepper motor.

[0042] Audible and visual alarm: The red LED and buzzer are activated when the pressure is <5 cmH2O or >10 cmH2O for more than 3 seconds.

[0043] Data logging function: Built-in Flash storage of pressure curves during the last 100 punctures, which can be exported via USB for postoperative analysis.

[0044] Results: Electronic closed-loop control can narrow the pressure fluctuation range to the target value ±0.5 cmH2O, the alarm function significantly reduces the risk of human error, and data recording is beneficial for clinical research to optimize the pressure threshold.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An auxiliary ventilation device for preventing gas embolism using one-lung positive pressure ventilation, comprising an air source connector (1), a precision flow regulating valve (2), a pressure generation and display module (3), and a patient connector (4). One end of the gas source connector (1) is connected to the air inlet of the precision flow regulating valve (2), and the other end of the gas source connector (1) is used to connect to the hospital's central oxygen supply or high-pressure oxygen cylinder. The outlet of the precision flow regulating valve (2) is connected to the inlet of the patient connector (4). The outlet of the patient connector (4) can be directly connected to the affected side cavity interface of a single-lumen endotracheal tube or a double-lumen bronchial tube (5). The pressure generation and display module (3) is installed on the patient connector (4).

2. The device for preventing gas embolism during one-lung ventilation according to claim 1, wherein: It also includes a safety relief valve (6), which is installed on the patient connector (4).

3. The auxiliary ventilation device for preventing gas embolism with one-lung positive pressure ventilation according to claim 1, characterized in that: The patient connector (4) is equipped with an anti-backflow valve near the single-lumen endotracheal tube or double-lumen bronchial tube (5).

4. The auxiliary ventilation device for preventing gas embolism with one-lung positive pressure ventilation according to claim 1, characterized in that: The precision flow regulating valve (2) is a medical needle valve.

5. An auxiliary ventilation device for preventing gas embolism using one-lung positive pressure ventilation according to any one of claims 1 to 4, characterized in that: The pressure generation and display module (3) includes a pressure sensor and a display screen. The pressure sensor is installed on the patient connector (4). The pressure signal collected by the pressure sensor is input into the microcontroller for processing and then drives the OLED display screen.

6. The auxiliary ventilation device for preventing gas embolism with one-lung positive pressure ventilation according to claim 5, characterized in that: It also includes a red LED and a buzzer, which are controlled by a microcontroller.

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