A ventilation system for surgical assistance with intraoperative respiratory status monitoring function

Abstract

The present invention discloses a ventilation system for surgical assistance with an intraoperative respiratory status monitoring function. The ventilation system includes: a nasal gas supply interface (101), a gas supply branch (102), an oral and nasal exhalation interface (103), a gas supply device (105), an exhalation branch (106), a buffer chamber (107), a flowmeter (108), a sampling device (120), and a gas composition measuring device (140). The ventilation system of the present invention can help doctors understand the patient's respiratory conditions throughout the operation, accurately detect the changing trend of the respiratory volume, the oxygen absorption ratio, the oxygen absorption amount, and the carbon dioxide emission amount of the patient at various stages of the operation, thereby contributing to the statistical research and learning after the operation and the monitoring of the patient's condition during the operation.

Description

Technical Field

[0001] The present invention relates to the field of respiratory assistance, and particularly to a surgical assistance ventilation system with intraoperative respiratory state monitoring function. Background Art

[0002] At present, although surgery has become the preferred means for people to treat major diseases, and in order to ensure the smooth progress of the surgery, anesthesia during the surgery is basically a necessary means. Patients, especially the elderly, have certain risks during general anesthesia surgery. The risks of anesthesia will present symptoms such as tachypnea, dyspnea, three depressions sign, cyanosis, etc. during the operation, and even cardiac arrest or death may occur. Therefore, preoperative examination is one aspect, and intraoperative monitoring is even more important.

[0003] Currently, intraoperative parameters such as heart rate and blood pressure can be monitored through corresponding detection devices, but there is still much room for improvement in the monitoring of the patient's respiratory condition.

[0004] Different types of ventilation systems may use different methods for gas recovery or direct discharge of exhaled gas when supplying oxygen to patients. Some ventilation systems have the ability to collect gas samples from patients to monitor respiration.

[0005] The gas sampling system transmits the air flow from the patient's airway to the sampling unit through a sampling tube, and measures the composition of the gas through the gas detection system in the sampling unit. The gas is continuously inhaled into the sampling unit through the sampling tube, and the sampling unit is located in the gas measuring instrument. Usually, the gas is sampled at a flow rate of about 30 ml / min to about 400 ml / min.

[0006] Existing sampling systems generally sample the patient's exhaled gas from the side, and the other gases exhaled by the patient are discharged into the air. However, such a sampling system has a major defect, that is, it can only know the content of oxygen or carbon dioxide in the exhaled gas sample of the patient, but it cannot determine how much oxygen the patient absorbs and how much carbon dioxide is exhaled during the breathing process, and does not know how the patient's breathing volume changes during the operation.

[0007] In addition, existing ventilation systems often adopt a single-in and single-out air supply method, and the sampling method is basically direct single-inlet sampling. Between the patient's nostrils, the air flow may often be very asymmetric. This may affect the efficiency of oxygen supply and the accuracy of sampling information.

[0008] Another monitoring method is based on blood oxygen content. Currently, blood oxygen level is measured by pulse oximetry, which can be classified as transmissive and reflective types. Both transmissive or transilluminative oximetry measure extinction when light passes through a portion of tissue perfused with blood. Light is emitted from one side of the tissue perfused with blood and recorded by a detector on the other side.

[0009] However, although this method can accurately reflect the local blood oxygen content of patients, due to the differences among patients, it is often difficult to accurately correspond the proportional relationship between the blood oxygen distribution in the same part of different patients and the patients' breathing conditions. That is, for two different patients, the breathing conditions reflected by the same blood oxygen content in the same part may be completely different. For example, the pulse oximetry of local injured patients (such as severely burned patients), civilian personnel, and manual laborers may show different situations. Even different surgical sites can affect the results. Therefore, these methods cannot accurately reflect the breathing conditions of different patients and cannot provide basic data for further in-depth research. Summary of the Invention

[0010] In view of the above problems existing in the prior art, the present invention provides a ventilation system that can reflect the whole-process oxygen absorption and carbon dioxide emission of patients during surgery, which can monitor the breathing conditions of patients in real time and collect the changes in the breathing volume, oxygen consumption, and oxygen absorption ratio at each stage of the patient's surgery.

[0011] In addition, the present invention solves the problem that the sampling device is easily contaminated by exhaled gas during the gas component monitoring process, thereby affecting the sampling accuracy.

[0012] Specifically, the present invention provides a surgical auxiliary ventilation system with an intraoperative breathing state monitoring function, which is characterized in that the ventilation system includes: a nasal gas supply interface, a gas supply branch, an oral and nasal exhalation interface, a gas supply device, an exhalation branch, a buffer chamber, a flowmeter, a sampling device, and a gas component determination device. Among them, the nasal gas supply interface is connected to one end of the gas supply branch, the other end of the gas supply branch is connected to the gas supply device, the oral and nasal exhalation interface is connected to the exhalation branch, a buffer chamber is provided in the exhalation branch, the sampling device is connected to the buffer chamber, the gas component determination device faces the sampling window of the sampling device for determining the gas components collected in the sampling device, and the flowmeter is arranged downstream of the buffer chamber for measuring the amount of exhaled gas of the patient.

[0013] In a preferred implementation, the oral and nasal exhalation interface is nested outside the nasal gas supply interface.

[0014] In another preferred implementation, the mouth and nose exhalation interface includes a breathing mask body, a fixing strap, and an exhaust interface.

[0015] In another preferred implementation, the ventilation system further includes a water-absorbing liner, which is disposed inside the mouth and nose exhalation interface, attached to the inner wall of the breathing mask body, and adopts an antibacterial design.

[0016] In another preferred implementation, the sampling device includes an outer sleeve, a front sealing member, a sampling head, a rear piston, a piston rod, and an odd-even hanging buckle.

[0017] In another preferred implementation, the part where the nasal air supply interface is connected to the air supply branch is made of an elastic memory material.

[0018] In another preferred implementation, the outer sleeve has a rectangular or cylindrical structure with openings at both ends.

[0019] In another preferred implementation, it further includes a pressure monitoring device, which is disposed in the buffer chamber.

[0020] It should be noted that the patient interface, mask and / or intubation discussed in the present invention with respect to human patients is not limited to the scope of only being used for human patients and can be used in various other environments. For example, the present invention can also be used in the veterinary field where the "patient" is an animal. With the increasing value of pets, intraoperative monitoring specifically for animals is not excluded in the future.

[0021] Technical Effects

[0022] The ventilation system of the present invention can effectively separate the air supply branch from the exhaust branch, and is easy to install. It effectively fixes the inhalation interface through the exhalation interface, avoiding the installation inconvenience problem of other dual-branch systems. Moreover, the present invention can help doctors understand the patient's breathing condition throughout the operation, accurately detect the change trend of the breathing volume, oxygen absorption ratio, oxygen absorption amount, and carbon dioxide emission amount of the patient at each stage of the operation, without the need to perform in a large exhaust gas collection and treatment system, thereby contributing to postoperative statistical research and learning as well as intraoperative patient condition monitoring. The present invention actually focuses more on medical research and has almost no impact on the wearing comfort of patients, far better than other implementations. Brief Description of the Drawings

[0023] Figure 1 It is a schematic structural diagram of the exhalation interface of the ventilation system for surgical assistance according to an embodiment of the present invention;

[0024] Figure 2 It is a schematic structural diagram of the nasal air supply interface of the ventilation system for surgical assistance according to an embodiment of the present invention;

[0025] Figure 3 This is a schematic structural diagram of the exhalation branch and the component measurement part in the ventilation system according to an embodiment of the present invention.

[0026] Figure 4 This is a schematic structural diagram of a sampling device in a preferred implementation manner according to an embodiment of the present invention. Specific embodiments

[0027] The present invention will be described in detail below with reference to the accompanying drawings and their embodiments, but the protection scope of the present invention is not limited to the scope described in the embodiments.

[0028] Embodiment 1

[0029] As Figures 1-3 shown, the surgical auxiliary ventilation system with intraoperative respiratory state monitoring function in this embodiment includes: a nasal gas supply interface 101, a gas supply branch 102, an oral and nasal exhalation interface 103, a water absorption gasket, an oxygen supply device 105, an exhalation branch 106, a buffer chamber 107, a flow meter 108, a detection branch 109, a sampling device 120, and a gas component measurement device 140.

[0030] The nasal gas supply interface 101 is connected to the gas supply branch 102. One end of the gas supply branch 102 is connected to the nasal gas supply interface 101, and the other end is connected to a gas supply device, such as an oxygen supply device. Preferably, a pure oxygen or an oxygen supply device with a clearly known oxygen content ratio is used. A gas mixing chamber can be provided in the middle of the gas supply branch 102. The gas mixing chamber can receive multiple inputs and output through the gas supply branch 102. For example, one path of the gas mixing chamber can receive the anesthetic gas output by an anesthetic machine and then mix with oxygen. As Figure 2 shown, the right end of the gas supply interface 101 is sealed, but it has a certain length at the right end to be pressed and fixed by the exhalation interface during installation.

[0031] The nasal gas supply interface 101 adopts a single-hole or double-hole nasal interface for the patient to inhale. In this embodiment, the latter is adopted. Preferably, the outer side of the double-hole nasal interface has an elastic sealing material, which is as sealed as possible with the nostrils after being inserted into the patient's nostrils. The oral and nasal exhalation interface 103 is nested outside the nasal gas supply interface 101 and adopts the form of a breathing mask to receive the gas exhaled by the patient. The nasal gas supply interface 101 is inside and the oral and nasal exhalation interface 103 is outside, thus forming a nested structure. The two can be a split structure with each other or an integrated structure. Preferably, the former is adopted. A sealing gap 1034 matching the gas supply branch 102 is left on both sides of the oral and nasal exhalation interface 103 to limit it within the exhalation interface 103 for fixation and allow the gas supply branch to extend into the mask.

[0032] The mouth and nose exhalation interface 103 includes a breathing mask body 1031, a fixing strap 1032, and an exhaust interface 1033. The breathing mask body 1031 fits the mouth and nose parts of the patient's face and protrudes outward. The exhaust interface 1033 is provided on the protruding part. The fixing strap 1032 is used to fix the mouth and nose exhalation interface. The air supply branch 102 passes through the sealing notch 1034 of the mouth and nose exhalation interface 103 and is connected to the nose air supply interface 101.

[0033] In a preferred implementation, the part where the nose air supply interface 101 is connected to the air supply branch 102 is made of elastic memory material, so that when the nose air supply interface 101 is worn on the patient, the orientation of the air supply branch 102 can be slightly adjusted. The mouth and nose exhalation interface 103 is fixedly connected to the exhaust branch 106 via the exhaust interface 1033.

[0034] Preferably, it further includes a water-absorbing liner (not shown in the figure), which is arranged inside the mouth and nose exhalation interface 103 and attached to the inner wall of the breathing mask body. The water-absorbing liner adopts an antibacterial design, for example, it includes an antibacterial material layer.

[0035] A buffer chamber 107 is arranged at a certain section of the exhalation branch 106. The flowmeter 108 is located in the exhalation branch 106, downstream of the buffer chamber 107, and is used to measure the gas flow rate flowing out of the buffer chamber.

[0036] The detection branch is arranged at the end of the buffer chamber and is used to guide the gas buffered in the buffer chamber into the sampling device 120.

[0037] The flowmeter 108 and the gas composition measuring device 140 cooperate closely. The gas composition measuring device measures the gas composition at a predetermined time interval. For example, the gas composition is measured once every 1 s, 0.5 s, or 0.1 s. The sampling device 120 of the gas composition measuring device is arranged at the position where the downstream of the buffer chamber is connected to the exhaust branch. During each measurement of the gas composition and concentration, the flowmeter measures the gas flow rate within a sampling period, and the ventilator respectively performs time integration on the product of the concentration and flow rate of each gas, so as to more accurately reflect the composition of the exhausted gas.

[0038] In the exhalation branch, a check valve is arranged downstream of the flowmeter 108 to prevent the exhausted gas from flowing back.

[0039] In a preferred implementation, a pressure sensor is disposed inside the breathing mask (exhalation interface) for measuring the air pressure waveform inside the breathing mask. When the pressure inside the breathing mask is higher than a predetermined value, a trigger signal is issued. A sliding isolation sheet 1071 is disposed inside the buffer chamber 107, and its periphery is sealed with the inner wall of the buffer chamber. A one-way ventilation port 1072 is disposed on the isolation sheet, and the movement of the sliding isolation sheet is driven by a micro hydraulic press or a motor to reciprocate along the buffer chamber. When the pressure inside the breathing mask is higher than the first threshold, the isolation sheet is driven to move downward (toward the exhaust direction), and then enters the exhaust cycle or the so-called exhalation cycle. During each patient exhalation cycle, sampling is performed one to multiple times. At least once before the exhalation cycle and once at the beginning of the exhalation cycle. During sampling, the sampling device extracts the sampling gas from the buffer chamber 107 and measures the composition of the sampling gas. At the same time, the sliding isolation sheet moves downward, driving the gas inside the buffer chamber to be discharged outward. At the same time, the flowmeter measures the flow rate of the discharged gas. When the pressure inside the breathing mask is lower than the second threshold or after a predetermined time (for example, 0.3 s), it indicates that the exhalation cycle has ended, and the sliding isolation sheet is driven to stop moving. When the pressure inside the breathing mask is lower than the third threshold or lower than the second threshold for a predetermined time, the sliding isolation sheet is driven to move in the reverse direction. The check valve downstream of the flowmeter prevents gas from flowing back. After moving a certain distance, the air pressure on both sides of the sliding isolation sheet is balanced. Further movement will open the one-way ventilation port on the sliding isolation sheet, and the gas near the upstream inside the buffer chamber will flow into the downstream. When the pressure inside the breathing mask is higher than the first threshold again, the next exhalation cycle is performed.

[0040] The present invention supplies gas to the patient by means of positive pressure ventilation and negative pressure exhaust. The pressure inside the nasal inhalation interface is greater than 1 atmosphere, and the pressure inside the breathing mask is less than 1 atmosphere. And the first threshold can be set to about 1 atmosphere or slightly lower than 1 atmosphere. In this way, when the patient exhales and the air pressure inside the mask increases, the air pressure inside the exhaust branch can be reduced to promote smooth exhalation of the patient. The first threshold, the second threshold, and the third threshold decrease in sequence. The second threshold can be set to 85-95% of 1 atmosphere, and the third threshold is set to avoid too low pressure in the exhaust branch and can be set to 75-85% of 1 atmosphere. Adopting this cycle method ensures smooth exhalation of the patient and the stability of the composition of the exhaled gas of the patient. Since the pressure of the air supply path is higher than 1 atmosphere and the pressure of the exhalation branch is lower than 1 atmosphere, it is beneficial to promote more smooth breathing and expectoration of the patient. And the present invention adopts a slow equalizing exhaust method to provide a stable negative pressure, while the existing air pump methods all have a certain air flow impact.

[0041] In addition, since the exhaled gas of the patient is fully mixed upstream of the buffer chamber first, and in each exhalation cycle, by synchronously measuring the flow rate and gas composition, integration can be performed for any time period to obtain the discharge amounts of various gas components in any time period, and then the oxygen absorption amount and absorption ratio during the patient's breathing process can be determined.

[0042] The gas component measuring device 140 uses an ultraviolet, visible light or infrared absorption analyzer, including a light source 141, a signal acquisition module 142, and a spectral analysis module 143. It should be noted that the technology of this absorption spectrometer is relatively mature, and the present invention can use an existing infrared absorption analyzer.

[0043] The light emitted by the light source is focused into the interior of the sampling device 120 from the first light passing window to irradiate the air therein. The signal acquisition device collects the laser light exiting from the second light passing window, and determines the absorption peaks corresponding to carbon dioxide and oxygen of the transmitted light through the absorption spectral analysis device, and determines the contents of carbon dioxide and oxygen in the exhaled gas based on the integration at the absorption peaks of carbon dioxide and oxygen.

[0044] The gas component measuring device determines the absorption peak of CO2 and the absorption peak of oxygen respectively based on the received transmitted light spectrum, and integrates the absorption peaks of the two respectively. However, considering that the sampling chamber will inevitably bring contamination inside the chamber and damage to the window as the usage time increases, the present invention uses a double-pressure two-measurement normalization compensation method to measure carbon dioxide and oxygen (and other components).

[0045] That is to say, when performing gas sampling, first perform normal gas sampling so that the air pressure in the sampling chamber is the same as that in the buffer chamber, which is P2, and perform an absorption spectral measurement once. Then compress the volume in the sampling chamber to half of the original volume (or 1 / M, where M is a positive integer greater than 2), so that the internal pressure increases to 2 times (or M times) the original, and perform a spectral measurement again. Then determine each gas component according to the following formula.

[0046] For example, for carbon dioxide, the formula is as follows:

[0047]

[0048] Where n represents the number of sampling times when the flow meter and the sampling device are synchronized. Generally, one or more samplings are performed in one exhalation cycle. λ C1 and λ C2 are the leading edge frequency and trailing edge frequency of the main absorption peak of carbon dioxide, Norm() represents the normalization operation, the normalization benchmarks at the two pressures P1 and P2 are the same, and Ab CO2-P1 represents the measured spectral peak height of carbon dioxide at the current frequency in the absorption spectrum when performing spectral measurement at the pressure P1.CO2-P2 represents the measured peak height of carbon dioxide at the current frequency in the absorption spectrum when spectral measurement is performed at pressure P2, where P1 is an integer multiple of P2. Cp CO2 is the compensation coefficient for carbon dioxide. This is because although the pressure doubles and the actual concentration of carbon dioxide doubles, the response in the spectrum is not completely linear, and there will be certain differences in the absorption ratios at different concentrations. CF CO2 is the spectral-concentration conversion coefficient for the absorption peak of carbon dioxide. Through this coefficient, different absorption peak intensities can be converted into corresponding carbon dioxide concentrations. ΔV n is the amount of gas discharged measured by the flowmeter during the current measurement cycle of spectral measurement. By summing the carbon dioxide concentrations of multiple measurement cycles, the total amount of carbon dioxide exhaled by the patient over any period of time can be obtained. The compensation parameter can be determined by prior concentration calibration.

[0049] Similarly, similar formulas are used for calculation for other gases. For example, for exhaled oxygen, the following formula is used:

[0050] The meanings of the various parameters in this formula are similar to those in the above formula (1). For other gas components to be measured, they can be obtained in a similar manner. Using this measurement method, interference can be effectively removed. Under laboratory conditions, when measuring carbon dioxide as an example, 10 different lenses are used, and each lens is measured 30 times. A Fourier transform infrared spectrometer with an error of 2% is used for testing, and then calibrated using an imported gas component measuring device with an error less than 0.1. Due to the error of the spectrometer itself plus the self-interference of the sampling tube, if measured directly in the conventional manner, the total error can reach 5% - 15%.

[0051] However, if the above measurement method of the present invention is used and a Fourier transform infrared spectrometer with a common error of 2% is used, the error can be reduced to less than 1.5% because the measurement error of the Fourier transform infrared spectrometer under the same conditions and the self-interference of the sampling tube are effectively eliminated.

[0052] In addition, in terms of the measurement of the total exhaled gas volume, since the present invention adopts effective synchronization of the flow rate and measurement, the measurement of the total flow rate can be made more accurate.

[0053] Preferably, the gas components and the gas supply volume supplied by the oxygen supply device can be determined by the readings of the flowmeter installed at the oxygen supply device. Especially for pure oxygen supply, the oxygen consumption can be determined by subtracting the oxygen amount in the discharged gas from the oxygen supply amount, and the consumption of H (in a ratio of 1:2) in carbohydrates during the patient's breathing process can be determined by subtracting the amount of carbon dioxide from the oxygen consumption, and thus the main energy source consumed during the patient's breathing process can be determined. CO can be ignored.

[0054] In a preferred implementation, as Figure 4 shown, the sampling device 120 includes an outer sleeve 121, a front seal 122, a sampling head 123, a rear piston 124, a piston rod 125, and an odd-even hanging buckle. The sampling device in this embodiment can achieve self-cleaning.

[0055] The outer sleeve 121 has a rectangular or cylindrical structure with openings at both ends. Here, the rectangular shape is taken as an example for detailed description.

[0056] The front seal 122 is arranged on the left side of the outer sleeve and fits tightly with the outer sleeve 121.

[0057] The sampling head 123 is installed in the middle of the left side of the front seal 122. The sampling head includes a sampling tube. The sampling head is installed on the front seal. The sampling tube is a columnar hollow tube, which is connected to the sampling branch and then communicated to the buffer chamber. In fact, the sampling tube can be directly used as the sampling branch.

[0058] The front seal has a certain thickness to maintain its posture inside the outer sleeve. Preferably, the sampling tube has a certain length, and an electric control valve is arranged in the middle of the sampling tube to control its opening and closing according to the sampling and exhaust instructions.

[0059] The rear piston 124 and the front seal 122 are installed inside the outer sleeve parallel to each other. The piston rod 125 is fixedly connected to the right side of the rear piston (it should be noted that the left and right here are only descriptions based on the orientation in the figure, and those skilled in the art can adjust according to needs in specific applications). The right side of the rear piston faces the front seal. A sealing plug protruding forward is provided in the middle of the rear piston, and the size of the sealing plug matches that of the sampling tube.

[0060] The piston rod 125 is installed in the piston rod fixing seat, and a driving device is arranged in the piston rod fixing seat to drive the piston rod to reciprocate inside the outer sleeve.

[0061] The odd-even hanging buckle includes a first buckle assembly 126 and a second buckle assembly 127, which are respectively installed on the opposite sides of the rear piston and the front seal. The function of the odd-even hanging buckle is that when the rear piston passes through the bottom of the cylinder (the right side of the cylinder) for the first time, the first buckle assembly and the second buckle assembly do not buckle, and when the rear piston passes through the bottom of the cylinder for the second time, the first buckle assembly and the second buckle assembly are buckled.

[0062] In this embodiment, an odd-even hanging buckle is realized electronically. The first buckle assembly installed on the front seal has a protruding part extending leftward. The top of the protruding part has a transverse hook. The right side of the rear piston has a second buckle assembly corresponding to the first buckle assembly. For example, the second buckle assembly includes a protruding part locking area for accommodating the protruding part and the transverse hook. The protruding part locking area has an electronically controlled locking tongue that can block the transverse hook when it extends, so as to connect the front seal and the rear piston into one body. The electronically controlled locking tongue is controlled by a microcontroller and a magnetic control device. When the rear piston extends into the outer sleeve an odd number of times, the locking tongue is controlled not to extend. When the rear piston extends into the outer sleeve an even number of times, the locking tongue extends to block the transverse hook.

[0063] There are two light-transmitting windows 131 and 132 on both side walls of the outer sleeve to allow light to pass through. The positions of the two light-transmitting windows are set according to detection needs. For example, they can be opposite to each other. In this embodiment, the opposite setting method is adopted. The inner surface of the light-transmitting window is in the same plane as the inner wall of the outer sleeve, and both are close to the side of the front seal.

[0064] In this embodiment, the sampling device can be self-cleaning:

[0065] In the initial state, the rear piston is located at the bottom of the outer sleeve, on the right side in the figure. The first buckle assembly and the second buckle assembly are not locked to each other. A stop block is provided on the left side of the front seal so that it can move to the right and will not move beyond the stop block to the left. There is a certain frictional force between the front seal and the outer sleeve, so it remains stationary during inhalation. When taking an air sample, the piston rod pulls the rear piston 124 to move to the right at a predetermined speed. While scraping and cleaning the inner wall of the outer sleeve through the piston, under the action of negative pressure, the gas in the target area is sucked through the sampling tube. The piston can play a basic cleaning process for the window.

[0066] When the air pressure inside it is the same as that in the buffer chamber (set as P2), the sampling is completed. The valve in the sampling tube is closed, and the light emitted by the light source irradiates into the outer sleeve through the window of the outer sleeve, and signal sampling is carried out from the other window.

[0067] After the first sampling is completed, the piston rod pushes the piston to the left. The valve in the sampling tube remains closed until the pressure inside it rises to P1 = M * P2, and then the second absorption spectrum measurement is carried out. Then, the valve of the sampling tube is opened, and the piston is pushed further to the left to discharge the sample air through the sampling tube. When the piston reaches the bottom, since this is an even number of times the piston enters, when the first and second buckle assemblies are in place, the microcontroller controls the locking tongue to extend and connect the piston to the front seal; Next, the piston drives the front seal to move to the left. During this process, the front seal scrapes the inner wall of the outer sleeve, further cleaning the inner wall of the outer sleeve.

[0068] Optionally, two through holes are provided on the piston. After the piston and the front seal reach the right side of the outer sleeve, a cleaning medium is introduced between the piston and the front seal through the first through hole 131, and the cleaning medium can be discharged from another pipeline 133.

[0069] The cleaning medium can be clean air or an organic solvent, and the particulate matter or dust scraped off by the front seal is blown through the recovery pipe for removal. In this way, since the space between the piston and the seal is narrow, and the dust on the side wall has been lifted by the seal through scraping, the cleaning effect is significantly improved compared with the method of directly introducing clean air. Of course, the cleaning process with the cleaning medium does not need to be carried out after each sampling, and can be carried out after a predetermined sampling cycle for deep cleaning.

[0070] Then, the piston rod pushes the piston and the seal to move leftward and returns to the sampling position again. At this time, since it is an odd number of times the piston rod advances, when it reaches the bottom, the latch is released and the piston is separated from the seal.

[0071] When sampling is required again, the piston rod pulls the piston to move rightward, and the inside of the outer sleeve is cleaned during the movement, so that the sample is contaminated as little as possible. Then, the sample can be detected and the next cycle can be carried out. Since the inner wall of the sampling tube is usually smooth enough and easy to clean, while the parts that are not easy to clean are the part where the piston contacts the tube wall and the sampling tube joint part, the method of the present invention can effectively clean the key parts.

[0072] By using the surgical assistant ventilator of the present invention, not only the total amount of the components of the patient's exhaled gas can be continuously monitored, but also by combining the measurement of the amount of oxygen supplied by the oxygen supply device, the oxygen demand of the patient at each surgical stage can be understood, which helps the doctor better understand the physiological changes of the patient during the operation.

[0073] Although the principle of the present invention has been described in detail above in conjunction with the preferred embodiments of the present invention, those skilled in the art should understand that the above embodiments are only explanations of the illustrative implementation modes of the present invention, and do not limit the scope of the present invention. The details in the embodiments do not constitute a limitation on the scope of the present invention. Without departing from the spirit and scope of the present invention, any obvious changes such as equivalent transformation and simple replacement based on the technical solution of the present invention all fall within the protection scope of the present invention.

Claims

1. A ventilation system for surgical assistance with intraoperative respiratory status monitoring function, characterized in that, The ventilation system includes: a nasal gas supply interface (101), a gas supply branch (102), an oral and nasal exhalation interface (103), a gas supply device (105), an exhalation branch (106), a buffer chamber (107), a flowmeter (108), a sampling device (120), and a gas composition measuring device (140). Among them, the nasal gas supply interface (101) is connected to one end of the gas supply branch (102), the other end of the gas supply branch (102) is connected to the gas supply device (105), the oral and nasal exhalation interface (103) is connected to the exhalation branch (106), a buffer chamber (107) is provided in the exhalation branch (106), the sampling device (120) is communicated with the buffer chamber, and the gas composition measuring device (140) faces the sampling window of the sampling device (120) for measuring the gas composition collected in the sampling device (120). The sampling device (120) includes an outer sleeve (121), a front seal (122), a sampling head (123), a rear piston (124), a piston rod (125), and an odd-even hanging buckle; Both ends of the outer sleeve (121) are open; The front seal (122) is arranged on the left side of the outer sleeve and is closely matched with the outer sleeve (121); The sampling head (123) is installed in the middle of the left side of the front seal (122). The sampling head includes a sampling tube. The sampling head is installed on the front seal (122). The sampling tube is a columnar hollow tube and is connected to the sampling branch and then communicated to the buffer chamber; The rear piston (124) and the front seal (122) are installed in the outer sleeve in parallel with each other. The piston rod (125) is fixedly connected to the right side of the rear piston. The right side of the rear piston faces the front seal. The middle of the rear piston has a sealing plug protruding forward, and the sealing plug matches the size of the sampling tube; The piston rod (125) is installed in a piston rod fixing seat, and a driving device is provided in the piston rod fixing seat to drive the piston rod to reciprocate in the outer sleeve; The odd-even hanging buckle includes a first buckle assembly (126) and a second buckle assembly (127), which are respectively installed on the opposite sides of the rear piston and the front seal. The function of the odd-even hanging buckle is that when the rear piston passes through the bottom of the cylinder for the first time, the first buckle assembly and the second buckle assembly do not buckle, and when the rear piston passes through the bottom of the cylinder for the second time, the first buckle assembly and the second buckle assembly are buckled When performing gas sampling, first perform normal gas sampling so that the air pressure in the sampling chamber is the same as that in the buffer chamber, which is P2, and perform an absorption spectrum measurement once. Then compress the volume in the sampling chamber to 1 / M of the original volume, so that the internal pressure increases to M times the original, and the pressure at this time is P1. M is 2. Perform a spectrum measurement again, and then determine each gas component according to the following formula: , where n represents the number of sampling times for the synchronization of the flowmeter and the sampling device, and one or more samplings are performed in one exhalation cycle. and are the leading-edge frequency and the trailing-edge frequency of the main absorption peak of carbon dioxide. Norm() represents the normalization operation, and the normalization reference is the same under the two pressures P1 and P2. represents the measured peak height of carbon dioxide at the current frequency in the absorption spectrum when spectroscopic measurement is performed under pressure P1. represents the measured peak height of carbon dioxide at the current frequency in the absorption spectrum when spectroscopic measurement is performed under pressure P2. is the compensation coefficient for carbon dioxide. is the spectral-concentration conversion coefficient for the absorption peak of carbon dioxide. is the amount of gas discharged measured by the flowmeter in the current measurement cycle of spectroscopic measurement.

2. The surgical assistance ventilation system with intraoperative respiratory state monitoring function according to claim 1, characterized in that, The oral and nasal exhalation interface (103) includes a breathing mask body (1031), a fixing belt (1032), and an exhaust interface (1033).

3. The surgical assistance ventilation system with intraoperative respiratory state monitoring function according to claim 2, characterized in that, It further includes a water-absorbing gasket (104) which is disposed inside the mouth and nose exhalation interface (103), attached to the inner wall of the breathing mask body, and adopts an antibacterial design.

4. The surgical ventilation system with intraoperative breathing state monitoring function according to claim 1, characterized in that, The part where the nasal air supply interface (101) is connected to the air supply branch (102) is made of an elastic memory material.

5. The surgical assistance ventilation system with intraoperative respiratory state monitoring function according to claim 1, characterized in that, The outer sleeve (121) has a rectangular or cylindrical structure with openings at both ends.

6. The ventilation system for surgical assistance with intraoperative respiratory state monitoring function according to claim 1, characterized in that, It further includes a pressure monitoring device which is disposed in the buffer cavity.

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