A ventilation catheter and connecting device with stable pressure difference

Abstract

The present invention discloses a ventilation catheter and a connecting device with stable pressure difference, which belong to the field of medical equipment. The invention comprises a ventilation catheter body with a sealing airbag at the front section, a pressure difference stabilizing cavity connected to the sealing airbag, a connecting pipe connected to the pressure difference stabilizing cavity and connected to a breathing circuit, during mechanical ventilation, the gas in the breathing circuit automatically regulates the pressure of the gas in the sealing airbag through the pressure difference stabilizing cavity, so that the pressure of the gas in the sealing airbag is greater than the pressure of the gas in the breathing circuit, and the pressure difference is stabilized at an appropriate value; the pressure of the sealing airbag of the ventilation catheter of the present invention changes dynamically and synchronously with the airway pressure of the mechanical ventilation, and in the exhalation phase of the mechanical ventilation with relatively low airway pressure, the gas pressure in the sealing airbag is relatively low, the blood circulation of the tracheal mucosa is restored, and the damage to the tracheal mucosa is avoided.

Description

Technical Field

[0001] The present invention generally relates to the medical field, and more particularly to the field of medical catheters. Background Art

[0002] Patients under general anesthesia or in the ICU need to have a tracheal tube placed into the trachea through the mouth or nose, and then the anesthesia machine or ventilator assists breathing. If the sealed sac compresses the tracheal mucosa for a slightly longer time, it will cause mild ischemic necrosis at the site of tracheal mucosa compression, which can easily lead to respiratory tract infection, cough, and even lung infection in patients, which is extremely detrimental to the patient's recovery; various serious complications may form at the site of tracheal mucosa compression: such as ① tracheoesophageal fistula, which seriously affects the patient's life safety, with a mortality rate of about 50%; ② scar formation of tracheal mucosa leads to tracheal stenosis, the scar gradually proliferates, the stenosis gradually worsens, and even affects the patient's ventilation, requiring tracheal stent placement, but it is only palliative treatment, and the patient cannot escape the fate of death; ③ tracheothoracic fistula causes tension pneumothorax, which has a very high mortality rate if not treated in time; ④ causes lung infection, or even chest infection, leading to empyema, which is also extremely difficult to treat.

[0003] In order to reduce the incidence of the above complications, the commonly used clinical methods are: ① When filling the tracheal tube sealing bag with gas, operate accurately and use a pressure gauge to inflate. The general inflation pressure is 30 mmHg, but in patients with poor lung compliance, the inflation pressure needs to be appropriately increased. This method avoids excessive inflation pressure of the balloon, minimizes the compression of the tracheal mucosa by the sealing balloon, and prolongs the time that the tracheal mucosa compression site tolerates compression, but patients with longer mechanical ventilation still cannot escape the fate of ischemic necrosis; ② In patients with endotracheal intubation and mechanical ventilation, the gas in the sealing balloon is evacuated regularly to restore the blood circulation of the airway mucosa temporarily. This method requires more manual intervention, which is time-consuming and labor-intensive. At the same time, when the gas in the sealing balloon is evacuated, the mechanical ventilation leaks seriously, which seriously affects the ventilation effect of the patient, affects the patient's oxygenation, and even causes hypoxia in the patient. If the operation is wrong and the gas is not replenished in the sealing balloon in time, it may even lead to extremely serious complications, such as hypoxemia, cardiac arrest, and even death. ③ For patients with endotracheal intubation and mechanical ventilation, use a double-sealed balloon endotracheal tube, and regularly rotate the compression position of the sealed balloon, so that the tracheal mucosa compressed by the balloon is regularly alternated between the two sealed balloons, and the tracheal mucosa compressed by the balloon is regularly restored. This method also requires a lot of manual intervention, which is time-consuming and labor-intensive. In case of improper operation: such as excessive gas pressure in the balloon, too long intervals between alternating inflations, forgetting to operate, etc., it may even cause ischemia and necrosis of the compression sites of the two sealed balloons, resulting in a doubling of the chance of complications. Even if the management is fully in place, in some patients with poor tolerance, the filling of 30 mmHg pressure will still seriously affect the blood circulation of the tracheal mucosa, and will still cause ischemia and necrosis.

[0004] We proposed a solution in application number 202210080092.3 to avoid compression and damage to the airway mucosa caused by the endotracheal tube sealing bag; however, the original solution required timely filling or discharging of an appropriate amount of gas from the sealing bag when the patient was receiving oxygen therapy in a hyperbaric oxygen chamber for pressurization or decompression, and medical staff were required to operate in a timely manner. Otherwise, it would cause serious mechanical ventilation leakage or severe compression of the patient's airway mucosa, and even more serious complications if not handled with care.

[0005] We further thought and verified on the original basis and proposed a new solution. This solution is safer. When the patient is receiving oxygen therapy in a hyperbaric oxygen chamber, there is no need to fill or discharge gas from the sealed airbag. The sealing of mechanical ventilation can be guaranteed under any circumstances, and damage to the inner wall of the airway mucosa can be avoided. Summary of the invention

[0006] In view of the above-mentioned defects of the prior art, the present invention provides a ventilation catheter with a stable pressure difference, comprising a ventilation catheter tube body, wherein the head section of the ventilation catheter tube body is provided with a sealing airbag, and a pressure difference stabilizing chamber is provided in communication with the sealing airbag. An inflation device and a one-way pressure relief exhaust valve are provided in communication with the pressure difference stabilizing chamber. The inflation device is provided with an air inlet and an air outlet. The air outlet is in communication with the pressure difference stabilizing chamber, and gas can be filled into the pressure difference stabilizing chamber through the inflation device. The pressure relief exhaust valve is provided with an air inlet and an air outlet, and a matching pressure relief valve and a pressure relief valve opening are provided in the inner cavity of the pressure relief exhaust valve, and the pressure relief valve is in forced active contact with the pressure relief valve opening on the side adjacent to the exhaust port. The air inlet is in communication with the pressure difference stabilizing chamber, and the pressure relief valve is in contact with gas in the breathing circuit during mechanical ventilation on the side of the exhaust port, and the pressure relief gas in the pressure difference stabilizing chamber can be discharged through the pressure relief exhaust valve.

[0007] A connection device with a stable pressure difference comprises a pressure differential stabilizing chamber, an inflation device and a one-way pressure relief exhaust valve are arranged in communication with the pressure differential stabilizing chamber. The inflation device is provided with an air inlet and an air outlet, the air outlet is communicated with the pressure differential stabilizing chamber, and gas can be filled into the pressure differential stabilizing chamber through the inflation device. The pressure relief exhaust valve is provided with an air inlet and an air outlet, the inner cavity of the pressure relief exhaust valve is provided with a matching pressure relief valve and a pressure relief valve opening, and the pressure relief valve is in force-active contact with the pressure relief valve opening on the side adjacent to the exhaust opening. The air inlet is communicated with the pressure differential stabilizing chamber, and the pressure relief valve is in contact with the gas in the breathing circuit during mechanical ventilation on the side of the exhaust opening, and the pressure relief gas in the pressure differential stabilizing chamber can be discharged through the pressure relief exhaust valve. The pressure differential stabilizing chamber is connected with an inflation fixing interface that matches the inflation opening of the ventilation catheter, and is provided with a breathing connection tube that matches the breathing circuit.

[0008] Furthermore, the air inlet of the inflation device is connected to the mechanical ventilation breathing circuit, and the exhaust port of the pressure relief exhaust valve is connected to the mechanical ventilation breathing circuit. The inflation device draws air from the mechanical ventilation breathing circuit and fills it into the pressure difference stabilization chamber. The pressure relief gas in the pressure difference stabilization chamber is discharged into the mechanical ventilation breathing circuit through the pressure relief exhaust valve.

[0009] Furthermore, the air inlet of the inflation device is connected to the outside, and the exhaust port of the pressure relief exhaust valve is connected to the outside. The pressure relief valve of the pressure relief exhaust valve is sealed and connected to the mechanical ventilation breathing circuit to set a pressure sensing soft membrane bag, and the exhaust port is set outside the soft membrane bag cavity.

[0010] Furthermore, the pressure relief exhaust valve includes an electromagnetic exhaust valve or a spring exhaust valve, and the exhaust threshold of the pressure relief exhaust valve can be adjusted by adjusting the resistance or the deformation amplitude of the spring.

[0011] Furthermore, the mechanical ventilation breathing circuit includes a ventilation catheter body and a breathing connection tube whose two ends are matched with the ventilation catheter body and the breathing threaded tube respectively.

[0012] Furthermore, the exhaust threshold value P5 of the pressure relief exhaust valve is the pressure difference between the gas pressure P3 in the pressure differential stable cavity and the gas pressure P in the mechanical ventilation breathing circuit. 气道 When (P3-P 气道 )>P5, the overflow valve leaves the overflow valve port, and the gas in the pressure difference stabilization chamber is discharged through the overflow exhaust valve. 气道 )<P5, the overflow valve blocks the overflow valve orifice, and the gas in the pressure difference stabilization cavity cannot be discharged through the overflow exhaust valve.

[0013] Furthermore, the exhaust threshold value P5 of the pressure relief exhaust valve (5) is less than 15 mmHg.

[0014] Furthermore, a gas pressure sensor is provided in the ventilation tube body sealing bag or the ventilation tube sealing bag to monitor and display the gas pressure P2 in the ventilation tube body sealing bag or the ventilation tube sealing bag. A gas pressure sensor is provided in the mechanical ventilation breathing circuit to monitor and display the gas pressure P2 in the mechanical ventilation breathing circuit. 气道 .

[0015] Furthermore, the pressure difference stabilization chamber is connected to the sealing airbag through an inflation tube, the inflation tube is provided with a switch, and the inflation tube is provided with a pressure valve inflation port on a side of the switch adjacent to the sealing airbag.

[0016] Beneficial effects of the present invention:

[0017] 1. During mechanical ventilation, the inspiratory phase is short and the expiratory phase is long (generally 1:2). At the same time, the airway pressure in the inspiratory phase is high (generally no more than 25 mmHg), and the pressure in the expiratory phase is low (generally no more than 5 mmHg); during the long expiratory phase of this device, the pressure of the sealed airbag is low, and the blood circulation of the tracheal mucosa at the compression site of the sealed airbag is almost unaffected, which can avoid ischemia of the tracheal mucosa;

[0018] 2. When the hyperbaric oxygen chamber is used for pressurization or decompression treatment, the pressure of the sealed airbag can be automatically adjusted along with the airway pressure without the need to inflate or deflate the airbag, thereby ensuring the sealing during mechanical ventilation and avoiding excessive pressure of the sealed airbag on the airway mucosa, thus ensuring the safety of patient oxygenation;

[0019] 3. No need for too much manual intervention to avoid forgetting. Just turn on the air pump at the beginning, no settings are required. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a cross-sectional structural diagram of a first embodiment of the present invention;

[0021] Figure 2 It is a cross-sectional structural diagram of a second embodiment of the present invention;

[0022] Figure 3 It is a cross-sectional structural diagram of a third embodiment of the present invention;

[0023] Figure 4 It is a cross-sectional structural diagram of a fourth embodiment of the present invention;

[0024] Figure 5 It is a cross-sectional structural diagram of a fifth embodiment of the present invention;

[0025] Figure 6 is a cross-sectional structural diagram of a sixth embodiment of the present invention;

[0026] Figure 7 For the present invention Figure 1 , 3 , 5. Schematic diagram of the overpressure gas overflow path;

[0027] Figure 8 For the present invention Figure 2 , 4 , 6. Schematic diagram of the overpressure gas overflow path;

[0028] Fig. 9 The present invention is the P2 and P during mechanical ventilation in PCV mode. 气道 Pressure-time graph.

[0029] Fig.10 The present invention is the combination of P2 and P during mechanical ventilation in VCV mode. 气道 Pressure time axis curve chart. Number and name:

[0030] 1-ventilation catheter body, 2-sealed airbag, 3-pressure difference stabilizing chamber, 4-inflating device, 41-air inlet, 42-air outlet, 5-pressure relief exhaust valve, 51-air inlet, 52-exhaust port, 53-pressure relief valve, 54-pressure relief valve port, 55-soft membrane bag, 6-inflating fixing interface, 7-breathing connection tube, 8-inflating tube, 81-switch, 82-pressure valve inflation port. DETAILED DESCRIPTION

[0031] In order to make the technical solution of the present invention better understood by the technical personnel in the field, and to make the above-mentioned features, purposes and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with the embodiments. The embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0032] like Figure 1-4 As shown, a ventilation catheter and connecting device with stable pressure difference includes a ventilation catheter body 1, and the ventilation catheter body 1 includes various types of tracheal catheter main tubes, such as single-lumen tracheal catheters, double-lumen tracheal catheters, bronchial occluders and tracheotomy ventilation tubes, etc. During mechanical ventilation, the head section of the ventilation catheter body 1 is retained in the patient's airway cavity, and the head section of the ventilation catheter body 1 is provided with a sealing airbag 2. By filling the sealing airbag 2 with a proper amount of gas, the pressure of the sealing airbag 2 is made greater than the airway pressure, and the sealing airbag 2 is in full contact with the mucosa in the airway cavity, thereby providing ventilation sealing for mechanical ventilation. These basic structures are basically similar to those of existing ventilation catheters and will not be repeated here.

[0033] During mechanical ventilation, the inspiratory phase is shorter and the expiratory phase is longer (generally 1:2). At the same time, the airway pressure is higher in the inspiratory phase and lower in the expiratory phase. The purpose of the present invention is to adjust the gas volume in the sealed airbag 2 so that the gas pressure in the sealed airbag 2 is lower during the expiratory phase, which accounts for a longer period of time and has a lower airway pressure, thereby reducing the pressure of the sealed airbag 2 on the airway mucosa. The blood circulation of the tracheal mucosa at the compression site of the sealed airbag 2 is restored during the expiratory phase, which accounts for a longer period of time and has a lower pressure. The blood circulation, which accounts for almost 2 / 3 of the ventilation time, is basically unaffected, thereby avoiding ischemia of the tracheal mucosa.

[0034] In order to achieve the above-mentioned design goals, the present invention is connected to the sealing airbag 2 to set a pressure difference stabilizing chamber 3, the function of which is to keep the gas pressure of the sealing airbag 2 and the gas pressure in the breathing circuit in a non-isobaric balance during mechanical ventilation. In other words, the gas pressure of the sealing airbag 2 is greater than the gas pressure in the breathing circuit, and the difference between the gas pressure in the sealing airbag 2 and the gas pressure in the breathing circuit is a stable value, which is controlled between 2-10mmHg, and 5mmHg is optimal. During mechanical ventilation, the pressure in the expiratory phase of most patients is relatively low, about 1mmHg; the pressure is relatively high during the inspiratory phase, about 15mmHg. By controlling the difference between the gas pressure in the sealing airbag 2 and the gas pressure in the breathing circuit to be controlled at 5mmHg, the gas pressure of the sealing airbag 2 (i.e., the pressure of the sealing airbag 2 on the airway inner wall mucosa) can be controlled to fluctuate between 6-20mmHg. The expiratory phase, which accounts for a relatively long period of time, is lower, at about 6 mmHg. In this way, the blood circulation of the airway inner wall mucosa compressed by the sealed airbag 2 during the expiratory phase is almost unaffected, thereby completely avoiding ischemic damage.

[0035] To achieve the above goals, Figure 1-4 As shown, a pressure differential stabilizing chamber 3 is provided in communication with the sealing airbag 2, and an inflating device 4 and a one-way pressure relief exhaust valve 5 are provided in communication with the pressure differential stabilizing chamber 3. The inflating device 4 continuously fills gas into the pressure differential stabilizing chamber 3, and discharges the overpressure gas through the one-way pressure relief exhaust valve 5, so that the pressure of the pressure differential stabilizing chamber 3 is greater than the airway pressure, and the difference is the pressure relief threshold value P5 of the one-way pressure relief exhaust valve 5. The pressure differential stabilizing chamber 3 is connected with the sealing airbag 2, and the pressure of the gas in the pressure differential stabilizing chamber 3 and the sealing airbag 2 is dynamically equal and balanced; thus, the pressure of the sealing airbag 2 is greater than the airway pressure.

[0036] The one-way pressure relief exhaust valve 5 is provided with an air inlet 51 and an exhaust port 52, wherein the air inlet 51 is communicated with the pressure differential stabilization chamber 3, and the inner cavity of the pressure relief exhaust valve 5 is provided with a matching pressure relief valve 53 and a pressure relief valve opening 54, wherein the pressure relief valve 53 is in active contact with the pressure relief valve opening 54 on the side adjacent to the exhaust port 52. The pressure relief valve 53 is in contact with the gas in the breathing circuit during mechanical ventilation on the side of the exhaust port 52, and the pressure relief gas in the pressure differential stabilization chamber 3 can be discharged through the pressure relief exhaust valve 5.

[0037] The inlet 51 of the one-way pressure relief exhaust valve 5 is connected to the pressure difference stabilization chamber 3, and the pressure relief valve 53 contacts the gas in the breathing circuit during mechanical ventilation on one side of the exhaust port 52, so that the gas pressure of the pressure difference stabilization chamber 3 and the gas pressure in the breathing circuit during mechanical ventilation are correlated with each other under the cooperation of the inflation device 4, so that the gas pressure P3 of the pressure difference stabilization chamber 3 and the gas pressure P 气道 Maintain in a non-equal equilibrium state, that is: P3>P 气道 , (P3-P 气道) is equal to the constant value (the exhaust pressure threshold value P5 of the one-way overflow exhaust valve 5), that is: (P3-P 气道 )≈P5. The gas pressure P3 of the pressure difference stabilization chamber 3 is in dynamic balance with the gas pressure P2 of the sealing airbag 2, P2≈P3, then: (P2-P 气道 )≈P5.

[0038] In actual application, under the action of the inflator 4, when (P3-P 气道 )>P5, (P3-P 气道 ) acts on the surface of the overflow valve 53, causing the overflow valve 53 to open to form a crack channel, and the gas in the pressure difference stabilization chamber 3 passes through the overflow valve port 54 through the crack channel and is discharged through the exhaust port 52; at this time, the gas pressure in the pressure difference stabilization chamber 3 drops rapidly. When (P3-P 气道 )≈P5, the overflow valve 53 closes again, the slit channel disappears, and the overflow valve 53 and the overflow valve orifice 54 return to the sealed closed state again.

[0039] The inflator 4 continuously fills the pressure difference stabilizing chamber 3 with gas to provide a gas source for the sealed airbag 2. In fact, the pressure difference stabilizing chamber 3 is only a hub connecting the sealed airbag 2, the inflator 4 and the one-way pressure relief exhaust valve 5, and its volume should not be too large. The inflator 4 can be set as an air pump. The micro air pump technology on the market is very mature, with a volume of only 1-2 cm. 3 Size, can be used as an accessory.

[0040] The following issues should be noted: when changing from the expiratory phase with lower airway pressure to the expiratory phase with higher airway pressure, the amount of gas in the sealing airbag 2 also needs to be quickly replenished, so that the air pressure in the sealing airbag 2 is quickly increased from slightly greater than the airway pressure in the expiratory phase to slightly greater than the airway pressure in the inspiratory phase, otherwise the sealing of the mechanical ventilation will be affected. In other words, the inflation device 4 must provide a sufficient inflation speed to the pressure difference stabilization chamber 3 to meet the minimum gas volume requirement.

[0041] Let us explain this issue below:

[0042] The volume of the sealing airbag 2 or the sealing airbag of the ventilation tube is V2. The V2 refers to the sum of the volumes of the sealing airbag 2 and the pressure difference stabilization chamber 3, i.e., the connecting pipeline. Even the largest type of ventilation device will not exceed 20ml (mostly around 10ml), and the limit value is: V2 = 20ml. The maximum pressure of the gas in the mechanical ventilation breathing circuit is P max , the minimum pressure is P minThe gas pressure in the mechanical ventilation breathing circuit is the airway pressure of the patient's mechanical ventilation. It is higher in the inspiratory phase. Normal people are generally below 15mmHg, and special patients rarely exceed 30mmHg. Here we take the highest adjustable value of the anesthesia machine safety pressure valve as 70mmHg. The airway pressure of mechanically ventilated patients is always positive, and the airway pressure in the expiratory phase generally does not exceed 5mmHg. We take the limit value as 0mmHg; the values ​​here are relative values ​​with the standard atmospheric pressure of 760mmHg as the zero point mark, and the absolute pressure values ​​are: P max = (760 + 70) mmHg = 830 mmHg; P min It is (760+0)mmHg=760mmHg.

[0043] According to Boyle's law, the gas that needs to be replenished into V2 is converted into P min The gas capacity, its volume V 补 =V 补 ≥(P max / P min -1)×V2;

[0044] In normal patients, the limit values ​​are: V2 = 20ml, P max =830mmHg, P min =760mmHg, substitute into the above formula:

[0045] V 补 ≥[(830 / 760)-1]×20ml;

[0046] V 补 ≥1.85ml;

[0047] The regional gas pressure is related to the altitude. The higher the altitude, the smaller the gas pressure. The highest altitude in the human habitation area on Earth is less than 4000 meters, and its air pressure is greater than 460mmHg. The limit values ​​are: V2 = 20ml, P max =(460+70)mmHg=530mmHg, P min =460mmHg, substitute into the above formula V 补 ≥(P max / P min -1)×V2:

[0048] V 补 ≥[(530 / 460)-1]×20ml;

[0049] V 补 ≥3.05ml;

[0050] When the patient needs to enter the hyperbaric oxygen chamber for treatment, the gas pressure of the hyperbaric oxygen chamber is 0.2-0.25MPa, that is, 1520-1900mmHg. The limit values ​​are: V2=20ml, P max =(1900+70)mmHg=1970mmHg, P min =1900mmHg, substitute into the above formula

[0051] V 补 ≥(P max / P min -1)×V2:

[0052] V 补 ≥[(1970 / 1900)-1]×20ml;

[0053] V 补 ≥0.74ml;

[0054] Obviously, the inflator pumps currently on the market can easily meet the above requirements. It should be noted that: since the invention maintains the gas pressure of the sealed airbag 2 and the gas pressure P in the breathing circuit during mechanical ventilation, 气道 The non-isobaric dynamic equilibrium, that is, (P2-P 气道 )≈P5, no special operation is required whether entering or exiting the hyperbaric oxygen chamber. It is only necessary to keep all parts of the invention in good working order.

[0055] like Figure 5-6 As shown, a pressure differential stable connection device of the present invention comprises a pressure differential stable chamber 3, and an inflation device 4 and a one-way pressure relief exhaust valve 5 are arranged in communication with the pressure differential stable chamber 3. The inflation device 4 is provided with an air inlet 41 and an air outlet 42, and the air outlet 42 is communicated with the pressure differential stable chamber 3, and gas can be filled into the pressure differential stable chamber 3 through the inflation device 4. The pressure relief exhaust valve 5 is provided with an air inlet 51 and an air outlet 52, and the inner cavity of the pressure relief exhaust valve 5 is provided with a matching pressure relief valve 53 and a pressure relief valve opening 54, and the pressure relief valve 53 is in active contact with the pressure relief valve opening 54 on the side adjacent to the air outlet 52. The air inlet 51 is communicated with the pressure differential stable chamber 3, and the pressure relief valve 53 is in contact with the gas in the breathing circuit during mechanical ventilation on the side of the air outlet 52, and the pressure relief gas in the pressure differential stable chamber 3 can be discharged through the pressure relief exhaust valve 5. The pressure difference stabilization chamber 3 is connected to an inflation fixing interface 6 matched with the inflation port of the ventilation tube, and is provided with a breathing connection tube 7 matched with the breathing circuit.

[0056] In this solution, the ventilation catheter body 1 is replaced by a ventilation catheter, which is consistent with the existing ventilation catheter. When in use, it is only necessary to connect the inflation fixing interface 6 to the ventilation catheter inflation port, and connect the breathing connection tube 7 to the breathing circuit during mechanical ventilation. The ventilation catheter includes a single-lumen endotracheal catheter, a double-lumen endotracheal catheter, a bronchial occluder, and a tracheotomy ventilation tube, etc. Its working principle is the same as the above Figure 1-4 The structure is exactly the same, except that it is separated from the ventilation catheter body 1, and will not be described in detail here.

[0057] like Figure 1 , Figure 3 and Figure 5 As shown, the air inlet 41 of the inflation device 4 is connected to the mechanical ventilation breathing circuit, and the exhaust port 52 of the pressure relief exhaust valve 5 is connected to the mechanical ventilation breathing circuit. The inflation device 4 draws air from the mechanical ventilation breathing circuit and fills it into the pressure difference stabilization chamber 3, and the pressure relief gas in the pressure difference stabilization chamber 3 is discharged into the mechanical ventilation breathing circuit through the pressure relief exhaust valve 5.

[0058] When it is working, the pressure and gas flow states in various aspects are as follows (the cross section of the overflow valve 53 on the side adjacent to the air inlet 51 is S, and the exhaust threshold of the overflow exhaust valve 5 is P5):

[0059] ① After successful endotracheal intubation, the patient's spontaneous breathing stops and the pressure in the patient's airway is the external environment pressure P 环境 The pressure relief valve 53 of the pressure relief exhaust valve 5 is subjected to a force F=(P 环境 +P5)×S; The inflator 4 of the present invention starts to work, extracts gas from the external environment, replenishes it into the pressure difference stabilization chamber 3, and then enters the sealed airbag 2 or the ventilation catheter sealed bag, so that the gas pressure in the sealed airbag 2 or the ventilation catheter sealed bag is rapidly increased to (P 环境 +P5); After the instantaneous pressure balance, the inflator 4 of the present invention continues to extract gas from the external environment and replenishes it into the sealed airbag 2 or the ventilation catheter sealed bag, but the gas that the inflator 4 continues to replenish makes the gas pressure in the pressure difference stabilization chamber 3 greater than (P 环境 +P5), the continuously replenished gas is in the overflow exhaust valve 5, pushes the overflow valve 53 toward the exhaust port 52, and then is discharged into the mechanical ventilation breathing circuit through the overflow valve port 54, and then enters the external environment.

[0060] ② After the breathing circuit is connected, the breathing device starts to work, pumping gas into the patient's lungs, entering the inspiratory phase, and the patient's airway pressure P 气道 Rapidly increase to the inspiratory phase pressure P 吸气 Correspondingly, the pressure relief valve 53 of the pressure relief exhaust valve 5 is subjected to a force F=(P 吸气 +P5)×S. At this time, the pressure of the overflow valve 53 on the side of the air inlet 51 is (P环境 +P5) is less than the pressure P on the exhaust port 52 side 吸气 +P5), the overflow valve 53 in the overflow exhaust valve 5 closes the overflow valve opening 54; the inflation device 4 draws gas from the mechanical ventilation breathing circuit, replenishes it into the pressure difference stabilization chamber 3, and then enters the sealing airbag 2 or the sealing bag of the ventilation catheter, so that the gas pressure in the sealing airbag 2 or the sealing bag of the ventilation catheter quickly increases from (P 环境 +P5) to (P 气道 +P5); After the instantaneous pressure balance, the inflator 4 of the present invention continues to extract gas from the mechanical ventilation breathing circuit and replenishes it into the sealed airbag 2 or the ventilation catheter sealed bag, but the gas that the inflator 4 continues to replenish makes the gas pressure in the pressure difference stabilization chamber 3 greater than (P 气道 +P5), the continuously replenished gas is in the overflow exhaust valve 5, pushes the overflow valve 53 toward the exhaust port 52, and then is discharged into the mechanical ventilation breathing circuit through the overflow valve port 54.

[0061] ③ The inspiratory phase ends, the respiratory device stops pumping gas into the patient's lungs, and under the elastic recoil force of the patient's chest wall, the patient's non-inner gas begins to be discharged, and the patient's airway pressure P 气道 Rapidly decrease to expiratory pressure P 呼气 Correspondingly, the pressure relief valve 53 of the pressure relief exhaust valve 5 is subjected to a force F=(P 呼气 +P5)×S. At this time, the pressure of the overflow valve 53 on the side of the air inlet 51 is (P 吸气 +P5) is greater than the pressure P on the exhaust port 52 side 呼气 +P5), the overflow valve 53 in the overflow exhaust valve 5 is pushed open, and the gas in the sealing bag 2 or the sealing bag of the ventilation catheter and the gas in the pressure difference stabilizing chamber 3 are discharged into the mechanical ventilation breathing circuit through the overflow valve opening 54; at the same time, the gas that the inflation device 4 continues to replenish in the pressure difference stabilizing chamber 3 is also discharged into the mechanical ventilation breathing circuit through the overflow valve opening 54, until the gas pressure in the sealing bag 2 or the sealing bag of the ventilation catheter drops to (P 呼气 +P5). In the subsequent exhalation phase, the gas pressure in the sealing bag 2 or the sealing bag of the ventilation tube is maintained at (P 呼气 +P5) remains unchanged, the gas in the sealing airbag 2 or the sealing bag of the ventilation catheter is no longer discharged into the pressure difference stabilization chamber 3, but the inflator 4 continues to replenish gas into the pressure difference stabilization chamber 3, but the replenished gas continues to be discharged into the mechanical ventilation breathing circuit through the overflow valve 54. At this time, in the overflow valve 5, the overflow valve 53 maintains a high-frequency open-close alternating state at the overflow valve 54.

[0062] ④ After the expiratory phase, the respiratory device pumps gas into the patient's lungs again and enters the inspiratory phase. The patient's airway pressure P 气道 Rapidly increase to the inspiratory phase pressure P 吸气Correspondingly, the pressure relief valve 53 of the pressure relief exhaust valve 5 is subjected to a force F=(P 吸气 +P5)×S. At this time, the pressure of the overflow valve 53 on the side of the air inlet 51 is (P 呼气 +P5) is less than the pressure P on the exhaust port 52 side 吸气 +P5), the overflow valve 53 in the overflow exhaust valve 5 closes the overflow valve opening 54; the inflation device 4 draws gas from the mechanical ventilation breathing circuit to replenish the pressure difference stabilization chamber 3, and then enters the sealing airbag 2 or the sealing bag of the ventilation catheter, so that the gas pressure in the sealing airbag 2 or the sealing bag of the ventilation catheter quickly increases from (P 呼气 +P5) to (P 吸气 +P5); After the instantaneous pressure balance, the inflator 4 of the present invention continues to extract gas from the mechanical ventilation breathing circuit and replenishes it into the sealed airbag 2 or the ventilation catheter sealed bag, but the gas that the inflator 4 continues to replenish makes the gas pressure in the pressure difference stabilization chamber 3 greater than (P 吸气 +P5), the continuously replenished gas is in the overflow exhaust valve 5, pushes the overflow valve 53 toward the exhaust port 52, and then is discharged into the mechanical ventilation breathing circuit through the overflow valve port 54.

[0063] ⑤ After that, the expiratory and inspiratory phases are repeated until the mechanical ventilation ends, the patient's spontaneous breathing is restored, and the breathing circuit is removed from the respiratory device. When the patient breathes spontaneously, the airway is under negative pressure P 自主 (less than the external ambient pressure), and both are less than P during mechanical ventilation 呼气 and P 吸气 At this time, correspondingly, the pressure relief valve 53 of the pressure relief exhaust valve 5 is subjected to a force F=(P 吸气 +P5)×S, or (P 吸气 +P5)×S. At this time, the pressure of the overflow valve 53 on the side of the air inlet 51 is (P 呼气 +P5) or (P 吸气 +P5) is greater than the pressure on one side of the exhaust port 52). The overflow valve 53 in the overflow exhaust valve 5 is opened, and the overflow valve 53 in the overflow exhaust valve 5 is pushed open, and the gas in the sealing airbag 2 or the sealing bag of the ventilation catheter and the gas in the pressure difference stabilization chamber 3 are discharged to the external environment through the overflow valve opening 54; at the same time, the gas that the inflation device 4 continues to replenish in the pressure difference stabilization chamber 3 is also discharged to the mechanical ventilation breathing circuit through the overflow valve opening 54, until the gas pressure in the sealing airbag 2 or the sealing bag of the ventilation catheter drops to P 自主 After observing for a period of time and the patient's spontaneous breathing is fully restored, the inflation device 4 can be turned off, the gas in the sealing airbag 2 can be extracted, and the ventilation catheter body 1 or the ventilation catheter can be pulled out.

[0064] like Figure 2 , Figure 4 and Figure 6As shown, the air inlet 41 of the inflation device 4 is connected to the outside, and the exhaust port 52 of the pressure relief exhaust valve 5 is connected to the outside. The pressure relief valve 53 of the pressure relief exhaust valve 5 is sealed and connected to the mechanical ventilation breathing circuit to set a pressure sensing soft membrane bag 55, and the exhaust port 52 is set outside the soft membrane bag 55 cavity. One side of the inside of the soft membrane bag 55 is sealed and connected to the pressure relief valve 53, and the pressure relief valve 53 is supported on the pressure relief valve opening 54. One side of the inside of the pressure relief valve 53 is connected to the breathing circuit through the soft membrane bag 55, and the gas pressure of the breathing circuit can act on the pressure relief valve 53 through one side of the inside of the soft membrane bag 55. The gas in the sealing airbag 2 or the sealing bag of the ventilation catheter acts on the pressure relief valve 53 on the outside of the soft membrane bag 55. The exhaust port 52 of the pressure relief exhaust valve 5 is set outside the soft membrane bag 55 on the side of the pressure relief valve opening 54 near the soft membrane bag 55. Its working principle is basically the same as above, except that in any state, the inflator 4 draws gas from the external environment to replenish the pressure difference stabilization chamber 3 and the sealed airbag 2 or the ventilation catheter sealed bag. Figure 8 As shown, when the overflow gas in the sealing airbag 2 is discharged through the overflow exhaust valve 5, the gas cannot enter the breathing circuit after the overflow valve 53 is opened due to the obstruction of the soft membrane bag 55, but is discharged to the external environment through the exhaust port 52 adjacent to the outside of the soft membrane bag 55. The advantage is that no matter whether the gas is added to or discharged from the sealing airbag 2 or the sealing bag of the ventilation catheter, it is isolated from the ventilation catheter body 1 or the ventilation catheter and the inner cavity of the breathing circuit, and will not affect the ventilation volume during mechanical ventilation. The solution described in claim 3 is Figure 1 , Figure 3 , Figure 5 The overpressure gas overflow line is as follows: Figure 7 As shown, since the supplementary gas or exhaust gas comes from the breathing circuit, and the gas difference is extremely small, it can be almost ignored compared to the volume of several hundred milliliters during mechanical ventilation.

[0065] Furthermore, the pressure relief exhaust valve 5 includes an electromagnetic exhaust valve or a spring exhaust valve, and the exhaust threshold of the pressure relief exhaust valve 5 can be adjusted by adjusting the resistance or the spring deformation amplitude. 2 The size is very low, the price is very low, the quality is stable, and it can be mass-produced. If an electromagnetic exhaust valve is used, a power supply needs to be allocated. The inflation device can also use a micro electric inflation pump, which is very common on the market and also needs to be allocated a power supply. A shared power supply can be used. If the power of the electric inflation pump or the exhaust threshold of the electromagnetic exhaust valve needs to be adjusted, it is only necessary to compensate for the adjustable resistor, which will not be described here. Figure 1-6 A spring exhaust valve is used in both, and its structure is also very common. If the exhaust threshold of the spring exhaust valve needs to be adjusted, the degree of compression deformation of the spring can be adjusted. This is also a common structure in spring exhaust valves and will not be described here.

[0066] Furthermore, the mechanical ventilation breathing circuit includes a ventilation catheter body 1 and a breathing connection tube 7 whose two ends are matched with the ventilation catheter body 1 and the breathing threaded tube respectively. Mechanical ventilation breathing circuit is a common name in anesthesia, including various pipelines connected to the patient's respiratory tract, such as: ventilation catheter body 1, ventilator threaded tube and breathing connection tube 7. The breathing connection tube 7 is also a common structure in anesthesia, with fixed calibers at both ends, which can be connected with the front and rear breathing tubes respectively, and will not be repeated here.

[0067] Furthermore, the exhaust threshold value P5 of the pressure relief exhaust valve 5 is the difference between the gas pressure P3 in the pressure difference stabilization chamber 3 and the gas pressure P 气道 When (P3-P 气道 )>P5, the overflow valve 53 leaves the overflow valve port 54, and the gas in the pressure difference stabilization chamber 3 is discharged through the overflow exhaust valve 5; when (P3-P 气道 )<P5, the overflow valve 53 blocks the overflow valve opening 54, and the gas in the pressure difference stabilization chamber 3 cannot be discharged through the overflow exhaust valve 5. This has been described in detail in the above content and will not be repeated here.

[0068] Furthermore, the exhaust threshold value P5 of the pressure relief exhaust valve 5 is less than 15 mmHg. In this solution, the pressure of the sealing airbag 2 on the inner wall of the airway is (P 气道 +P5), the airway pressure in the expiratory phase is mostly less than 3mmHg, and the pressure of the sealed airbag 2 on the airway inner wall is less than 18mmHg (15mmHg+3mmHg). This is much lower than the current airbag pressure on the airway inner wall set at 30mmHg on the market, and has actual clinical significance. In actual implementation, 5mmHg is the most appropriate, and the corresponding airway pressure in the expiratory phase is less than 8mmHg. In this pressure range, the blood supply of the airway inner wall is almost unaffected, which can ensure that the airbag avoids compression damage to the airway inner wall.

[0069] Further, a gas pressure sensor is provided in the ventilation catheter body 1 and the sealing airbag 2 or the ventilation catheter sealing airbag to monitor and display the gas pressure P2 in the ventilation catheter body 1 and the sealing airbag 2 or the ventilation catheter sealing airbag; a gas pressure sensor is provided in the mechanical ventilation breathing circuit to monitor and display the gas pressure P in the mechanical ventilation breathing circuit. 气道 . Set up gas pressure sensors to monitor P2 and P 气道 Its significance lies in: ① timely observing the airway pressure state of the patient during mechanical ventilation; ② timely observing the compression state of the air bag on the inner wall of the airway during mechanical ventilation; ③ dynamically monitoring P2 and P 气道 The difference (P2-P 气道 ), difference (P2-P 气道 ) is greater than 0, the airway sealing during mechanical ventilation can be ensured; otherwise, it is necessary to increase the power of the inflation device 4. Fig. 9 , 10 The following is a timeline chart of the pressure of P2 and P in the two most common breathing modes. If P2 and P are monitored dynamically at the same time, 气道 The pressure value only needs to adjust the power of the inflator 4 to make P2 and P 气道 The pressure-time axis lines are separated and never intersect. The absence of intersections ensures that mechanical ventilation does not leak. At the same time, P2 and P 气道 The pressure difference fluctuates around P5, which can meet the actual needs of clinical applications.

[0070] Further, such as Figure 1-4 As shown, the pressure difference stabilization chamber 3 is connected with the sealing airbag 2 through the inflation tube 8, and the inflation tube 8 is provided with a switch 81. The inflation tube 8 is provided with a pressure valve inflation port 82 on the side of the switch 81 near the sealing airbag 2. By providing the switch 81 and the pressure valve inflation port 82 on the inflation tube 8, it can be achieved that: ① before the tracheal intubation operation, the gas in the sealing airbag 2 is exhausted through the pressure valve inflation port 82, and the airbag is prevented from being over-inflated during the intubation operation, which makes the intubation difficult and reduces the intubation damage; ② if the inflation device 4 or the overflow exhaust valve 5 fails, the switch 81 is closed, and a proper amount of gas is filled into the sealing airbag 2 through the pressure valve inflation port 82, which can achieve the function of the traditional tracheal tube; ③ when the mechanical ventilation is over and the tracheal tube needs to be pulled out, the switch 81 is closed, and the gas in the sealing airbag 2 is exhausted through the pressure valve inflation port 82, so as to avoid the airbag from being over-inflated and reduce the injury of the tube removal.

[0071] In summary, the present invention sets a pressure difference stabilization chamber, and during mechanical ventilation, the gas in the breathing circuit automatically regulates the pressure of the gas in the sealed airbag through the pressure difference stabilization chamber, so that the gas pressure in the sealed airbag is greater than the gas pressure in the breathing circuit, and the pressure difference is stabilized at an appropriate value; the pressure of the sealed airbag of the ventilation catheter of the present invention changes dynamically and synchronously with the airway pressure of the mechanical ventilation. In the expiratory phase of the mechanical ventilation when the airway pressure is relatively low, the gas pressure in the sealed airbag is relatively low, the blood circulation of the tracheal mucosa is restored, and the damage to the tracheal mucosa is avoided.

Claims

1. A ventilation catheter with a stable pressure difference, comprising a ventilation catheter tube body (1), wherein the head section of the ventilation catheter tube body (1) is provided with a sealing airbag (2), characterized in that: A pressure differential stabilization chamber (3) is provided in communication with the sealing airbag (2); an inflation device (4) and a one-way pressure relief exhaust valve (5) are provided in communication with the pressure differential stabilization chamber (3); the inflation device (4) is provided with an air inlet (41) and an air outlet (42); the air outlet (42) is communicated with the pressure differential stabilization chamber (3), and gas can be filled into the pressure differential stabilization chamber (3) through the inflation device (4); the pressure relief exhaust valve (5) is provided with an air inlet (51) and an air outlet (52), and the air outlet (42) is communicated with the pressure differential stabilization chamber (3), and gas can be filled into the pressure differential stabilization chamber (3) through the inflation device (4); the pressure relief exhaust valve (5) is provided with an air inlet (51) and an air outlet (52), and the air outlet (42) is communicated with the pressure differential stabilization chamber (3); The inner cavity of the pressure exhaust valve (5) is provided with a matching overflow valve (53) and an overflow valve opening (54), and the overflow valve (53) is in force-movable contact with the overflow valve opening (54) on the side adjacent to the exhaust port (52); the air inlet (51) is connected to the pressure difference stabilization chamber (3), and the overflow valve (53) is in contact with the gas in the breathing circuit during mechanical ventilation on the side of the exhaust port (52), and the overflow gas in the pressure difference stabilization chamber (3) can be discharged through the overflow exhaust valve (5); The exhaust threshold value P5 of the pressure relief exhaust valve (5) is the difference between the gas pressure P3 in the pressure difference stabilization chamber (3) and the gas pressure Pairway in the mechanical ventilation breathing circuit; when (P3 - P 气道 )>P5, the overflow valve (53) leaves the overflow valve opening (54), and the gas in the pressure difference stabilization chamber (3) is discharged through the overflow exhaust valve (5); when (P3 -P 气道 )<P5, the overflow valve (53) blocks the overflow valve opening (54), and the gas in the pressure difference stabilization chamber (3) cannot be discharged through the overflow exhaust valve (5).

2. The ventilation catheter with stable pressure difference according to claim 1, characterized in that: The air inlet (41) of the inflation device (4) is connected to the mechanical ventilation breathing circuit; the exhaust port (52) of the pressure relief exhaust valve (5) is connected to the mechanical ventilation breathing circuit; the inflation device (4) draws air from the mechanical ventilation breathing circuit and fills it into the pressure difference stabilization chamber (3), and the pressure relief gas in the pressure difference stabilization chamber (3) is discharged into the mechanical ventilation breathing circuit through the pressure relief exhaust valve (5).

3. The ventilation catheter with stable pressure difference according to claim 1, characterized in that: The air inlet (41) of the inflation device (4) is connected to the outside, and the exhaust port (52) of the pressure relief exhaust valve (5) is connected to the outside; the pressure relief valve (53) of the pressure relief exhaust valve (5) is sealed and connected to the mechanical ventilation breathing circuit to set a pressure sensing soft membrane bag (55), and the exhaust port (52) is set outside the cavity of the soft membrane bag (55).

4. The ventilation catheter with stable pressure difference according to claim 1, characterized in that: The pressure relief exhaust valve (5) comprises an electromagnetic exhaust valve or a spring exhaust valve, and the exhaust threshold of the pressure relief exhaust valve (5) can be adjusted by adjusting the resistance or the deformation amplitude of the spring.

5. The ventilation catheter with stable pressure difference according to claim 1, characterized in that: The mechanical ventilation breathing circuit comprises a ventilation catheter tube body (1) and a breathing connection tube (7) whose two ends are matched with the ventilation catheter tube body (1) and the breathing threaded tube respectively.

6. The ventilation catheter with stable pressure difference according to claim 1 or 4, characterized in that: The exhaust threshold value P5 of the pressure relief exhaust valve (5) is less than 15 mmHg.

7. The ventilation catheter with stable pressure difference according to claim 1 or 2, characterized in that: A gas pressure sensor is provided in the ventilation catheter tube body (1) and the sealing airbag (2) or the ventilation catheter sealing airbag to monitor and display the gas pressure P2 in the ventilation catheter tube body (1) and the sealing airbag (2) or the ventilation catheter sealing airbag; a gas pressure sensor is provided in the mechanical ventilation breathing circuit to monitor and display the gas pressure P2 in the mechanical ventilation breathing circuit. 气道 .

8. The ventilation catheter with stable pressure difference according to claim 1, characterized in that: The pressure difference stabilization chamber (3) is connected to the sealing airbag (2) via an inflation tube (8), the inflation tube (8) is provided with a switch (81), and the inflation tube (8) is provided with a pressure valve inflation port (82) on the side of the switch (81) adjacent to the sealing airbag (2).

9. A connection device with stable pressure difference, characterized in that: The invention comprises a pressure difference stabilizing chamber (3), an air charging device (4) and a one-way pressure relief exhaust valve (5) which are connected to the pressure difference stabilizing chamber (3); the air charging device (4) is provided with an air inlet (41) and an air outlet (42); the air outlet (42) is connected to the pressure difference stabilizing chamber (3), and gas can be charged into the pressure difference stabilizing chamber (3) through the air charging device (4); the pressure relief exhaust valve (5) is provided with an air inlet (51) and an air outlet (52); the pressure relief exhaust valve (5) is provided with an air inlet (51) and an air outlet (52); (5) The inner cavity is provided with a matching overflow valve (53) and an overflow valve opening (54), and the overflow valve (53) is in force-movable contact with the overflow valve opening (54) on the side adjacent to the exhaust port (52); the air inlet (51) is connected to the pressure difference stabilization cavity (3), and the overflow valve (53) is in contact with the gas in the breathing circuit during mechanical ventilation on the side of the exhaust port (52), and the overflow gas in the pressure difference stabilization cavity (3) can be discharged through the overflow exhaust valve (5). The pressure difference stabilization chamber (3) is connected to an inflation fixing interface (6) matching the inflation port of the ventilation tube, and is provided with a breathing connection tube (7) matching the breathing circuit; The exhaust threshold value P5 of the pressure relief exhaust valve (5) is the difference between the gas pressure P3 in the pressure difference stabilization chamber (3) and the gas pressure Pairway in the mechanical ventilation breathing circuit; when (P3 - P 气道 )>P5, the overflow valve (53) leaves the overflow valve opening (54), and the gas in the pressure difference stabilization chamber (3) is discharged through the overflow exhaust valve (5); when (P3 -P 气道 )<P5, the overflow valve (53) blocks the overflow valve opening (54), and the gas in the pressure difference stabilization chamber (3) cannot be discharged through the overflow exhaust valve (5).

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