Gas path system of full-relying intravenous anesthesia machine and full-relying intravenous anesthesia machine

Abstract

The invention is suitable for the technical field of medical equipment, and provides a gas circuit system of a full-relying intravenous anesthesia machine and the full-relying intravenous anesthesia machine, and the gas circuit system comprises an inspiration gas circuit and an expiration gas circuit; the inspiration air path comprises an oxygen source branch, an air source branch, an inspiration main path and an emergency manual ventilation branch; the expiration air path comprises an expiration main path, an automatic expiration branch and a manual expiration branch; the oxygen source branch comprises a high-pressure oxygen branch, a flow adjusting device and a low-pressure oxygen branch; the emergency manual ventilation branch is connected with the oxygen source branch and the inspiration main path; the expiration main path is provided with an expiration switching device; flow direction control assemblies are arranged in the high-pressure oxygen branch and the low-pressure oxygen branch; at least two of the oxygen source branch, the air source branch and the main inspiration path are provided with inspiration flow detection devices; a supercharging device is arranged in the air source branch or the air suction main. The problem that a low-pressure oxygen source and ambient air cannot be efficiently integrated and utilized in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a total intravenous anesthesia machine gas circuit system and a total intravenous anesthesia machine. Background Art

[0002] Total Intravenous Anesthesia (TIVA), as a technique that does not use inhaled anesthetics and completely relies on intravenous injection of drugs to induce and maintain the anesthetic state, has been increasingly widely used in clinical practice. Compared with inhaled anesthesia, TIVA has the advantages of high quality of awakening, low incidence of postoperative nausea and vomiting, and greater safety for specific patient groups (such as malignant hyperthermia susceptibles). During TIVA, the patient's spontaneous breathing is usually inhibited or disappears. Therefore, mechanical ventilation support is crucial for maintaining the patient's normal physiological functions. This poses specific requirements for anesthesia machines dedicated to or compatible with TIVA scenarios.

[0003] However, when existing anesthesia machines are applied to TIVA, there are still some problems to be solved: 1. Challenges in gas source adaptability and utilization efficiency: The main task of an anesthesia machine in TIVA mode is to deliver a precisely controlled mixture of oxygen and air (or nitrogen). However, it usually has the following problems: Dependence on high-pressure gas sources: Traditional designs still tend to rely on high-pressure oxygen provided by the hospital central gas supply system or use high-pressure gas cylinders. This limits the application of the device in environments lacking such facilities (such as certain grass-roots units, during transportation, and temporary surgical sites).

[0004] Insufficient utilization of low-pressure oxygen sources (such as oxygen generators): With the development of bedside oxygen generator technology, it has the potential as a convenient oxygen source. However, some existing anesthesia machines have low compatibility and boosting efficiency with low-pressure oxygen sources, which may lead to unstable oxygen supply or difficulty in achieving the required tidal volume and flow rate.

[0005] Optimization of environmental air utilization: When a lower inspired oxygen concentration is required, efficiently and stably inhaling and precisely delivering filtered environmental air is a key. The suction capacity and flow control accuracy of some systems for environmental air need to be improved, especially the stability under different ventilation modes and parameters.

[0006] 2. Redundant Dependence on and Insufficient Optimization of Components of Traditional Inhalation Anesthesia Systems: Many anesthesia machines are still designed with inhalation anesthesia as the core, including vaporizers, anesthesia gas circuits, carbon dioxide absorption devices, etc. In the TIVA mode, these components not only become redundant, increasing the complexity, volume, and cost of the equipment, but may also potentially affect ventilation accuracy due to issues such as pipeline dead space and airtightness. Although anesthesia machines specifically designed for TIVA remove these components, there is still room for improvement in gas source utilization and gas path simplicity.

[0007] 3. Balance between Simplicity of Gas Path Design and Ventilation Performance: To achieve the switching, mixing, and delivery of multiple gas sources, gas path design is often complex. This not only increases internal resistance and potential leakage points but may also affect the precise control and response speed of ventilation parameters. How to further simplify the gas path while ensuring ventilation performance, improving the reliability and maintainability of the system, is an issue that needs to be considered in the design of TIVA anesthesia machines.

[0008] 4. Quick Response and Safety Backup in Emergencies: Although TIVA itself does not involve inhalation anesthetics, patient ventilation safety is always the top priority. In the event of power failure, malfunction of the main control system, or the need to urgently supply high-concentration oxygen, the anesthesia machine should be able to quickly and reliably switch to the standby ventilation mode or provide manual ventilation support. There is still room for improvement in the design and usability of existing systems in this regard.

[0009] Therefore, in the context of TIVA specifically, how to more efficiently integrate and utilize low-pressure oxygen sources and ambient air, further optimize the gas path to improve ventilation efficiency and responsiveness, and ensure operational convenience and safety in various situations, remains a challenge and development direction in the current technical field. Summary of the Invention

[0010] Based on this, the objective of the present invention is to provide a total intravenous anesthesia machine gas path system and a total intravenous anesthesia machine to fundamentally solve the problem of the existing inability to efficiently integrate and utilize low-pressure oxygen sources and ambient air.

[0011] A total intravenous anesthesia machine gas path system according to an embodiment of the present invention includes an inhalation gas path for delivering breathing gas to a patient and an exhalation gas path for guiding the exhaled gas of the patient; The inhalation gas path includes an oxygen gas source branch, an air gas source branch, an inhalation main path, and an emergency manual ventilation branch, and the exhalation gas path includes an exhalation main path, an automatic exhalation branch, and a manual exhalation branch; The oxygen gas source branch includes a high-pressure oxygen branch, a flow regulating device connected to the output end of the high-pressure oxygen branch, and a low-pressure oxygen branch whose output end is connected to the front end or the rear end of the flow regulating device. The flow regulating device is used to regulate at least a part of the oxygen flow rate in the oxygen gas source branch; The total inhalation path is respectively connected to the output ends of the oxygen gas source branch and the air gas source branch, and is used to mix the gases respectively transported by the oxygen gas source branch and the air gas source branch, and form a mixed gas to be transported to the patient; The emergency manual ventilation branch is respectively connected to the oxygen gas source branch and the total inhalation path, and is used to provide manual ventilation to the patient under preset conditions; The total exhalation path is provided with an exhalation switching device. The two output ends of the exhalation switching device are respectively connected to the automatic exhalation branch and the manual exhalation branch, and are used to control the total exhalation path to be selectively communicated with the automatic exhalation branch or the manual exhalation branch; Wherein, a flow direction control component is further provided in the high-pressure oxygen branch and the low-pressure oxygen branch, which is used to control the flow direction of oxygen in the high-pressure oxygen branch and the low-pressure oxygen branch; At least two of the oxygen gas source branch, the air gas source branch and the total inhalation path are provided with inhalation flow detection devices, which are used to detect the gas flow rate at the corresponding positions; A pressurizing device is provided in the air gas source branch or the total inhalation path, which is used to pressurize the gas from the air gas source branch, or pressurize the mixed gas after mixing the oxygen gas source branch and the air gas source branch.

[0012] In addition, a gas path system of a total intravenous anesthesia machine according to the above embodiments of the present invention may further have the following additional technical features: Further, the front end of the emergency manual ventilation branch is connected to the front end of the flow regulating device, and the rear end of the emergency manual ventilation branch is connected to the input end of the total inhalation path or the rear end of the pressurizing device or the front end of the inhalation flow detection device.

[0013] Further, the flow direction control component includes a first anti-backflow device connected to the input end of the high-pressure oxygen branch, and a second anti-backflow device connected to the input end of the low-pressure oxygen branch. The output end of the second anti-backflow device is connected to the front end or the rear end of the flow regulating device.

[0014] Further, the flow direction control component is a first switching device provided at the output ends of the high-pressure oxygen branch and the low-pressure oxygen branch and converging to the front end of the flow regulating device. The two input ends of the first switching device are respectively connected to the output ends of the high-pressure oxygen branch and the low-pressure oxygen branch, and the output end of the first switching device is connected to the front end of the flow regulating device.

[0015] Further, a second switching device is also provided in the low-pressure oxygen branch. The output end of the second anti-backflow device is connected to the input end of the second switching device, and the two output ends of the second switching device are respectively connected to the front end and the rear end of the flow rate regulating device.

[0016] Further, the high-pressure oxygen branch further includes at least one of a first filtering device, a first pressure sensing device, and a first pressure regulating device arranged in sequence, and the low-pressure oxygen branch further includes a second filtering device.

[0017] Further, the air gas source branch further includes at least one of a third filtering device, a fourth filtering device, and a second pressure sensing device arranged in sequence.

[0018] Further, the total inhalation path further includes at least one of a mixing chamber, an inhalation valve, a third anti-backflow device, a third pressure sensing device, an oxygen concentration detection device, and a humidifying device arranged in sequence. The output ends of the oxygen gas source branch and the air gas source branch are both connected to the mixing chamber.

[0019] Further, the emergency manual ventilation branch includes at least one of a quick oxygen switch for controlling on / off and a ventilation device composed of a manual flow rate regulating device and a third switching device. The input end of the emergency manual ventilation branch is connected to the input end of the quick oxygen switch and / or the input end of the manual flow rate regulating device. The output end of the quick oxygen switch is connected to the output end of the emergency manual ventilation branch. The output end of the manual flow rate regulating device is connected to the input end of the third switching device. The two output ends of the third switching device are respectively connected to the output end of the emergency manual ventilation branch and the auxiliary output interface.

[0020] Further, a safety valve connected to the output end of the exhalation switching device and an exhalation valve connected to the safety valve are provided on the automatic exhalation branch, and an airbag connected to the output end of the exhalation switching device and an adjustable pressure limiting valve connected to the airbag are provided on the manual exhalation branch.

[0021] Further, the gas path system of the total intravenous anesthesia machine further includes a gas flow rate detection device, which is arranged in the total exhalation path and connected to the input end of the exhalation switching device, or arranged in the proximal total path where the total inhalation path and the total exhalation path are commonly connected.

[0022] Another object of the present invention is to provide a total intravenous anesthesia machine, including the gas path system of the total intravenous anesthesia machine as described above and a controller.

[0023] The gas path system of the total intravenous anesthesia machine provided by the embodiment of the present invention integrates a pressurizing device into the air gas source branch or the total inhalation path, and optimizes the oxygen gas source branch to be compatible with high-pressure oxygen sources and low-pressure oxygen sources. At this time, the pressurizing device ensures that the low-pressure oxygen source or the ambient air source can be stably sucked and pressurized to the working pressure, enabling the total intravenous anesthesia machine to effectively utilize low-pressure oxygen sources and ambient air, and no longer being limited to places where high-pressure gas sources are required. This significantly improves the applicability and deployment flexibility of the device in different medical environments. At the same time, in cooperation with the inhalation flow detection devices and flow regulating devices provided in at least two of the oxygen gas source branch, the air gas source branch, and the total inhalation path, precise metering and on-demand mixing of gases from different sources are achieved, ensuring accurate control of the inhaled oxygen concentration and tidal volume. By connecting the output ends of the oxygen gas source branch and the air gas source branch to the total inhalation path and combining precise flow regulation and monitoring, it is ensured that oxygen and air can be fully mixed and delivered to the patient at a stable flow rate and a set oxygen concentration, improving the quality of ventilation treatment. By setting up a flow direction control component, the high-pressure oxygen branch and the low-pressure oxygen branch are effectively isolated, preventing unwanted backflow or pressure shock of gases between gas sources of different pressure levels, protecting the gas source equipment, and ensuring the stability of the supply pressure and the purity of the gas components. The independently designed emergency manual ventilation branch can be optionally equipped with a fast oxygen switch (for quickly delivering high-flow pure oxygen) and / or a ventilation device composed of a manual flow regulating device and a third switching device (which can provide an adjustable continuous oxygen flow and can be directed to the patient or an auxiliary output interface), ensuring that life support can be quickly provided to the patient in case of an emergency, improving the operation convenience and the ability to handle emergencies. The exhalation switching device can control the connection between the total exhalation path and the automatic exhalation branch (including a safety valve and an exhalation valve) or the manual exhalation branch (including an airbag and an adjustable pressure limiting valve), enabling the total intravenous anesthesia machine to automatically switch the exhalation path according to the ventilation mode or provide necessary pressure limitation during manual ventilation, ensuring the effectiveness of exhalation management in different modes and enhancing the operation safety. At the same time, various sensors such as pressure sensing devices, inhalation flow detection devices, gas flow detection devices, and oxygen concentration detection devices are set at key nodes of the gas path (such as the high-pressure oxygen branch, the low-pressure oxygen branch, the air branch, the total inhalation path, and the total exhalation path). These sensors cooperate with the controller to be able to real-time monitor various parameters during the ventilation process, providing a data basis for achieving precise closed-loop control, timely alarm, and fault diagnosis, and enhancing the intelligent level and clinical use safety of the total intravenous anesthesia machine. It solves the problem that the existing technology cannot efficiently integrate and utilize low-pressure oxygen sources and ambient air. Description of the Drawings

[0024] Figure 1 It is a schematic structural diagram of the total intravenous anesthesia machine in the first embodiment of the present invention; Figure 2Another schematic structural diagram of the total intravenous anesthesia machine in the first embodiment of the present invention; Figure 3 Another schematic structural diagram of the total intravenous anesthesia machine in the first embodiment of the present invention; Figure 4 Another schematic structural diagram of the total intravenous anesthesia machine in the first embodiment of the present invention; Figure 5 Another schematic structural diagram of the total intravenous anesthesia machine in the first embodiment of the present invention; Figure 6 Another schematic structural diagram of the total intravenous anesthesia machine in the first embodiment of the present invention; Figure 7 Another schematic structural diagram of the total intravenous anesthesia machine in the first embodiment of the present invention; Figure 8 Another schematic structural diagram of the total intravenous anesthesia machine in the first embodiment of the present invention; The following specific embodiments will further illustrate the present invention in conjunction with the above-mentioned drawings.

[0025] Explanation of the reference numerals in the drawings: 1. High-pressure oxygen branch; 11. First gas source interface; 12. First filtering device; 13. First anti-reflux device; 14. First pressure sensing device; 15. First pressure regulating device; 16. Flow rate regulating device; 17. First inspiratory flow rate detection device; 2. Low-pressure oxygen branch; 21. Second gas source interface; 22. Second filtering device; 23. Second anti-reflux device; 24. First switching device; 25. Second switching device; 3. Air gas source branch; 31. Third gas source interface; 32. Third filtering device; 33. Fourth filtering device; 34. Second pressure sensing device; 35. Second inspiratory flow rate detection device; 4. Total inspiratory path; 41. Mixing chamber; 42. Inspiratory valve; 43. Third inspiratory flow rate detection device; 44. Third anti-reflux device; 45. Third pressure sensing device; 46. Oxygen concentration detection device; 47. Humidifying device; 48. Pressurizing device; 49. Inspiratory port; 5. Emergency manual ventilation branch; 51. Quick oxygen switch; 52. Manual flow rate regulating device; 53. Third switching device; 54. Auxiliary output interface; 6. Total expiratory path; 61. Expiratory port; 62. Gas flow rate detection device; 63. Expiratory switching device; 7. Automatic expiratory branch; 71. Safety valve; 72. Expiratory valve; 8. Manual expiratory branch; 81. Airbag; 82. Adjustable pressure limiting valve; 9. Proximal total path; 10. Controller. Specific embodiments

[0026] To facilitate the understanding of the present invention, the present invention will be described more comprehensively below with reference to the relevant drawings. Several embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present invention more thorough and comprehensive.

[0027] It should be noted that when an element is referred to as being "fixedly provided on" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0029] Embodiment 1 Please refer to Figures 1-8 , which shows the total intravenous anesthesia machine applied to the gas path system of the total intravenous anesthesia machine in the first embodiment of the present invention. For the sake of convenience of description, only the parts related to the embodiments of the present invention are shown. The gas path system of the total intravenous anesthesia machine provided by the embodiments of the present invention includes an inhalation gas path for delivering breathing gas to the patient and an exhalation gas path for guiding the exhaled gas of the patient; The inhalation gas path includes an oxygen gas source branch, an air gas source branch 3, an inhalation main path 4 and an emergency manual ventilation branch 5, and the exhalation gas path includes an exhalation main path 6, an automatic exhalation branch 7 and a manual exhalation branch 8; The oxygen gas source branch includes a high-pressure oxygen branch 1, a flow rate regulating device 16 connected to the output end of the high-pressure oxygen branch, and a low-pressure oxygen branch 2 whose output end is connected to the front end or the rear end of the flow rate regulating device. The flow rate regulating device is used to regulate at least a part of the oxygen flow rate passing through the oxygen gas source branch; The inhalation main path is respectively connected to the output ends of the oxygen gas source branch and the air gas source branch, and is used to mix the gases respectively delivered by the oxygen gas source branch and the air gas source branch and form a mixed gas to be delivered to the patient; The emergency manual ventilation branch is respectively connected to the oxygen gas source branch and the inhalation main path, and is used to provide manual ventilation to the patient under preset conditions; The total exhalation path is provided with an exhalation switching device 63. The input end of the exhalation switching device is connected to the gas flow detection device. The two output ends of the exhalation switching device are respectively connected to the automatic exhalation branch and the manual exhalation branch, and are used to control the total exhalation path to be selectively communicated with the automatic exhalation branch or the manual exhalation branch; Wherein, flow control components are also provided in the high-pressure oxygen branch and the low-pressure oxygen branch to control the oxygen flow direction in the high-pressure oxygen branch and the low-pressure oxygen branch; at least two of the oxygen gas source branch, the air gas source branch and the total inhalation path are provided with inhalation flow detection devices to detect the gas flow at the corresponding positions; a pressurization device 48 is provided in the air gas source branch or the total inhalation path to pressurize the gas from the air gas source branch, or to pressurize the mixed gas after mixing the oxygen gas source branch and the air gas source branch.

[0030] Wherein, the inhalation gas path is responsible for delivering the precisely mixed breathing gas to the patient. As an example, one end of the inhalation gas path is connected to the external environment or a low-pressure gas source or a high-pressure gas source, and the other end is provided with an inhalation port 49 for the patient to inhale. The exhalation gas path is responsible for guiding the gas exhaled by the patient and performing necessary processing and monitoring. As an example, one end of the exhalation gas path is connected to the exhalation port 61, and the other end is connected to the external environment for transmitting the gas exhaled by the patient to the external environment.

[0031] Further, in an embodiment of the present invention, the main components of the inhalation gas path include an oxygen gas source branch, an air gas source branch, a total inhalation path and an emergency manual ventilation branch, wherein the oxygen gas source branch is used to provide oxygen. In order to adapt to different oxygen sources, the oxygen gas source branch includes a high-pressure oxygen branch and a low-pressure oxygen branch. The input end (i.e., the first gas source interface 11) of the high-pressure oxygen branch is connected to a high-pressure oxygen source, such as the oxygen outlet of a central gas supply system or a high-pressure oxygen cylinder. The input end (i.e., the second gas source interface 21) of the low-pressure oxygen branch is connected to a low-pressure oxygen source, such as the output port of a medical oxygen generator. The flow regulating device is the core of oxygen flow control, and the flow regulating device can be a high-precision electronically controlled proportional valve (such as a piezoelectric ceramic valve or an electromagnetic proportional valve) or a mass flow controller (MFC), which can accurately adjust the oxygen flow rate flowing through according to the instructions of the connected controller 10. At this time, referring to Figures 1-5 shown, the flow regulating device can be set to be connected to the output ends of the high-pressure oxygen branch and the low-pressure oxygen branch at the front end; of course, referring to Figure 7As shown, the flow regulating device can also be set such that its front end is connected to the output end of the high-pressure oxygen branch, and its rear end is connected to the output end of the low-pressure oxygen branch. When the output ends of the low-pressure oxygen branch and the high-pressure oxygen branch converge at the front end (i.e., the input end) of the flow regulating device, the flow regulating device adjusts the flow rate of oxygen from a single source (i.e., only one-way oxygen supply), that is, only one of the low-pressure oxygen branch or the high-pressure oxygen branch will be selected to operate at this time, and the low-pressure oxygen branch and the high-pressure oxygen branch will not be controlled to operate simultaneously. When the output end of the low-pressure oxygen branch is connected to the rear end (i.e., the output end) of the flow regulating device, the flow regulating device only adjusts the flow rate of the high-pressure oxygen output from the high-pressure oxygen branch. At this time, when the gas path system uses low-pressure oxygen, its flow rate may be controlled by the oxygen generator itself or indirectly controlled through other auxiliary means (such as adjusting the ratio with the air flow). Therefore, this flow regulating device is used to adjust the flow rate of at least a part of the oxygen in the oxygen gas source branch, such as adjusting the flow rate of oxygen in one of the above-mentioned low-pressure oxygen branch or high-pressure oxygen branch. It should be noted that in this total intravenous anesthesia machine gas path system, five oxygen supply modes can be set according to the required oxygen concentration for the patient. When only the oxygen concentration in the ambient air is required, oxygen supply is directly carried out through the air gas source branch. When only 100% pure oxygen is required, oxygen supply is carried out through the high-pressure oxygen branch or the low-pressure oxygen branch of the oxygen gas source branch. That is to say, only a single branch can be selected for pure oxygen supply, and the high-pressure oxygen branch and the low-pressure oxygen branch cannot be operated simultaneously for oxygen supply. When oxygen with a preset oxygen concentration (between 21% and 100%) is required, any one of the high-pressure oxygen branch or the low-pressure oxygen branch of the oxygen gas source branch is mixed with the air gas source branch as needed to achieve the required oxygen concentration.

[0032] Furthermore, in order to ensure that oxygen of different pressure levels can be correctly and safely selected or mixed and flow into the system as needed, and to prevent interference or backflow with each other, a flow direction control component is provided. Among them, in one embodiment of the present invention, referring to Figures 1-4As shown, the flow control component includes a first anti - backflow device 13 (including but not limited to check valves, pneumatically controlled valves, electrically controlled valves) connected to the input end of the high - pressure oxygen branch, and a second anti - backflow device 23 (including but not limited to check valves, pneumatically controlled valves, electrically controlled valves) connected to the input end of the low - pressure oxygen branch. The output end of the second anti - backflow device is connected to the front end or the rear end of the flow regulating device. When the high - pressure oxygen source supplies gas, the first anti - backflow device opens and oxygen enters. At the same time, if the pressure of the low - pressure oxygen branch is lower than that of the high - pressure oxygen branch, the second anti - backflow device will prevent the high - pressure oxygen from flowing back to the low - pressure oxygen source. When the low - pressure oxygen source supplies gas (possibly with pressure - boosting assistance), the second anti - backflow device opens and oxygen enters. At the same time, if the high - pressure oxygen branch is not supplying gas or has a lower pressure, the first anti - backflow device will prevent the low - pressure oxygen from flowing back to the high - pressure oxygen source. This ensures that the gas can only flow unidirectionally, effectively preventing gas mixing and backflow between gas sources of different pressure levels, protecting the gas source equipment, and ensuring the purity and pressure stability of the gas supply. At the same time, according to the connection method of the low - pressure oxygen, the output end of the second anti - backflow device can be selectively connected to the front end or the rear end of the flow regulating device. At this time, referring to Figures 1-5 as shown, the output end of the second anti - backflow device is connected to the front end of the flow regulating device; and referring to Figure 7 as shown, the output end of the second anti - backflow device is connected to the rear end of the flow regulating device.

[0033] Among them, in another embodiment of the present invention, referring to Figure 5 as shown, the flow control component is a first switching device 24 arranged at the output ends of the high - pressure oxygen branch and the low - pressure oxygen branch and converging to the front end of the flow regulating device. The first switching device can be an electrically controlled or manually operated two - way three - way valve or a similar valve group structure. Among them, the first switching device preferably adopts a manually operated two - way three - way valve, which is used to realize the switching between the high - pressure oxygen branch and the low - pressure oxygen branch even when the power supply of the total intravenous anesthesia machine gas path system is lost. The two input ends of the first switching device are respectively connected to the output ends of the high - pressure oxygen branch and the low - pressure oxygen branch, and the output end of the first switching device is connected to the front end of the flow regulating device. At this time, by controlling the first switching device, high - pressure oxygen or low - pressure oxygen can be selected for use. Specifically, the controller or the operator can selectively connect one of the high - pressure oxygen branch or the low - pressure oxygen branch to the flow regulating device by controlling the first switching device. Therefore, through the above design, the active selection and switching between the high - pressure oxygen source and the low - pressure oxygen source are realized. Compared with the simple first anti - backflow device and the second anti - backflow device, the first switching device can more clearly isolate the unused gas source, and the control logic is clearer.

[0034] Furthermore, in an embodiment of the present invention, referring to Figure 6As shown, in the low-pressure oxygen branch, after the second anti-backflow device, a second switching device 25 may also be provided. The output end of the second anti-backflow device is connected to the input end of the second switching device, and the two output ends of the second switching device are respectively connected to the front end and the back end of the flow regulating device. The second switching device may be an electrically controlled or manual two-way three-way valve or a similar valve group structure, and preferably a manual two-way three-way valve is adopted for the corresponding second switching device. When the second switching device connects the low-pressure oxygen to the front end of the flow regulating device, both the low-pressure oxygen and the high-pressure oxygen can optionally be adjusted through the flow regulating device. When the second switching device connects the low-pressure oxygen to the back end of the flow regulating device, the low-pressure oxygen will bypass the flow regulating device. At this time, the flow regulating device is mainly used to regulate the high-pressure oxygen flow. When the flow regulating device is not working, the low-pressure oxygen can be directly used as a supplementary oxygen source. This design provides a more flexible choice for the low-pressure oxygen access point. For example, when it is necessary to quickly increase the oxygen concentration or the flow regulating device focuses on high-pressure oxygen regulation, by connecting the low-pressure oxygen branch to the back end of the flow regulating device through the second switching device, the bypass supplement of the low-pressure oxygen can be realized, which increases the diversity of the oxygen delivery strategy and the fineness of control.

[0035] Furthermore, in an embodiment of the present invention, the air gas source branch is used to provide air, usually the filtered ambient air inhaled from the surrounding environment, and of course, it can also be a high-pressure air source. The input end of the air gas source branch (i.e., the third gas source interface 31) is connected to the air source, and the output end of the air gas source branch and the output end of the oxygen gas source branch jointly merge into the inhalation main path.

[0036] Furthermore, in an embodiment of the present invention, the inhalation main path is the main channel (i.e., the proximal main path 9) where oxygen and air are mixed and finally delivered to the patient. The input end of the inhalation main path is respectively connected to the output end of the oxygen gas source branch (i.e., after the flow regulating device) and the output end of the air gas source branch. Its core function is to mix the gases from oxygen and air to form a mixed gas with a specific oxygen concentration. The mixed gas is then delivered to the proximal main path through the output end of the inhalation main path (i.e., the inhalation port 49) and then to the patient.

[0037] Further, in an embodiment of the present invention, the pressurizing device is the key to realizing the utilization of ambient air or a low-pressure oxygen source. The pressurizing device can be a medical-grade turbo fan, scroll pump, compressor, cylinder, piezoelectric pump, diaphragm pump, etc. The speed or working state of the pressurizing device is controlled by the controller 10 to provide the required flow rate and pressure. The pressurizing device can be arranged in the air gas source branch or the total inhalation path to pressurize the gas from the air gas source branch, or to pressurize the mixed gas in the total inhalation path after the mixing of the oxygen gas source branch and the air gas source branch. Specifically, the pressurizing device is arranged before the output end of the air gas source branch or after the input end of the total inhalation path. When the air is from the environment or the pressure of the low-pressure oxygen source is insufficient, the pressurizing device can pressurize the gas to the required working pressure. Refer to Figure 2 and Figure 4 As shown, when the pressurizing device is located before the output end of the air gas source branch, the inhaled ambient air is pressurized and then mixed with the oxygen from the oxygen gas source branch in the total inhalation path. Refer to Figure 1 and Figure 3 As shown, when the pressurizing device is located after the input end of the total inhalation path (i.e., after the initial convergence of oxygen and air), the preliminarily mixed oxygen and air are pressurized as a whole. At this time, by setting the position of the pressurizing device, the design flexibility is provided, and the optimal solution can be selected according to the characteristics of the pressurizing device and the overall performance requirements of the system. For example, if more precise pressure control of the mixed gas is required, pressurizing in the total inhalation path may be more appropriate. At the same time, through the setting of the pressurizing device, the total intravenous anesthesia machine can get rid of the dependence on a high-pressure air source and can directly use ambient air or work in cooperation with a low-pressure oxygen source, greatly expanding the applicable scenarios of the total intravenous anesthesia machine and reducing the operating cost.

[0038] Further, an inhalation flow rate detection device (such as a thermal mass flow sensor, differential pressure flow sensor) is provided at least in two of the oxygen gas source branch, the air gas source branch, and the total inhalation path. Specifically, an inhalation flow rate detection device is provided at least in two of the three positions: before the output end of the oxygen gas source branch, before the output end of the air gas source branch, and after the input end of the total inhalation path. At this time, at least two independent gas flow rates or the flow rate of the mixed gas are monitored. Specifically, for example, a first inhalation flow rate detection device 17 is arranged before the output end of the oxygen gas source branch (after the flow rate regulating device), a second inhalation flow rate detection device 35 is arranged before the output end of the air gas source branch, and a third inhalation flow rate detection device 43 is arranged after the input end of the total inhalation path. For example, refer to Figure 1 and Figure 3 As shown, at this time, the above-mentioned first inhalation flow rate detection device and the third inhalation flow rate detection device are mainly arranged; and refer to Figure 2 and Figure 4As shown, at this time, the above-mentioned first inspiratory flow rate detection device and second inspiratory flow rate detection device are mainly set. Of course, optionally, in addition to the above illustration, a second inspiratory flow rate detection device and a third inspiratory flow rate detection device can also be set, or directly set the above three inspiratory flow rate detection devices, and the above inspiratory flow rate detection devices are set according to actual usage needs. At this time, these inspiratory flow rate detection devices are used to monitor the gas flow rate of each path in real time and feedback the data to the controller. At this time, the controller can calculate the gas flow rate of the remaining path based on the gas flow rates monitored by any two of the three gas paths, so that the controller can accurately calculate and control the gas mixing ratio (oxygen concentration) and the tidal volume / minute ventilation volume delivered to the patient, providing a guarantee for accurate ventilation.

[0039] Further, in an embodiment of the present invention, the emergency manual ventilation branch is a standby path. When the automatic ventilation system fails or rapid manual intervention is required, oxygen can be directly delivered to the patient through this emergency manual ventilation branch to ensure the safety of the patient. Among them, the front end of the emergency manual ventilation branch is connected to the front end of the flow rate adjustment device (that is, connected to the oxygen source that has not been adjusted by the flow rate adjustment device, usually a high-pressure oxygen source and a low-pressure oxygen source, and is equipped with an independent manual flow rate adjustment device such as a rotameter). At this time, the oxygen used for emergency manual ventilation is the oxygen that has not been adjusted by the flow rate adjustment device and has a relatively high pressure, ensuring the driving force during manual ventilation. And the rear end of the emergency manual ventilation is connected to the input end of the total inspiratory path or the rear end of the pressurization device or the front end of the inspiratory flow rate detection device that is finally delivered to the patient. Specifically, when the pressurization device is arranged on the air gas source branch, the rear end of the emergency manual ventilation is connected to the input end of the total inspiratory path. When the pressurization device is arranged on the total inspiratory path, the rear end of the emergency manual ventilation is connected to the rear end of the pressurization device. When the third inspiratory flow rate detection device is arranged on the total inspiratory path, the rear end of the emergency manual ventilation is connected to the front end of the third inspiratory flow rate detection device. At this time, the flow rate of manual ventilation can also be monitored. Through the above connection method, it is ensured that in an emergency, oxygen can bypass the main automatic control loop and be directly delivered to the patient or delivered to the patient after passing through the fewest components. At the same time, the selection of the connection point of the emergency manual ventilation takes into account both the directness of oxygen supply and the utilization of the existing pipeline.

[0040] Further, in an embodiment of the present invention, the high-pressure oxygen branch further includes at least one of a first filtering device 12, a first pressure sensing device 14, and a first pressure regulating device 15 arranged in sequence. The first filtering device is used to remove impurities in the high-pressure oxygen. The first pressure sensing device is used to monitor the pressure of the high-pressure oxygen source to determine whether the gas source is sufficient. The first pressure regulating device (such as a pressure reducing valve) is used to reduce the pressure of the high-pressure oxygen source to the working pressure range inside the intravenous anesthesia machine. Further, the low-pressure oxygen branch further includes a second filtering device 22. The second filtering device is used to remove possible impurities in the gas output from the low-pressure oxygen source (such as an oxygen generator). Therefore, through the above settings, the pretreatment ability and monitoring ability of the gas source are enhanced. The pressure regulation and pressure monitoring of the high-pressure oxygen branch ensure the stable gas pressure entering the subsequent system and the knowable state of the gas source. The filtering device ensures the cleanliness of the gas entering the patient.

[0041] Further, in an embodiment of the present invention, the air gas source branch further includes at least one of a third filtering device 32, a fourth filtering device 33, and a second pressure sensing device 34 arranged in sequence. The third filtering device and the fourth filtering device are usually a combination of a primary (coarse filter) and a high-efficiency filter (fine filter, such as HEPA) for removing dust, particulate matter, and even bacteria in the ambient air. The second pressure sensing device is used to monitor the pressure at the air inhalation end or the pressure of the air source (if it is high-pressure air). Therefore, through the above settings, the cleanliness of the inhaled air is ensured, which is particularly important for a system that directly uses ambient air. The pressure monitoring helps to judge the clogging situation of the filter or the state of the air source.

[0042] Further, in an embodiment of the present invention, the total inhalation path further includes at least one of a mixing chamber 41, an inhalation valve 42, a third anti-reflux device 44, a third pressure sensing device 45, an oxygen concentration detection device 46, and a humidifying device 47 arranged in sequence. The output ends of the oxygen gas source branch and the air gas source branch are both connected to the mixing chamber for promoting the full mixing of oxygen and air. The output end of the inhalation valve is usually connected to the output end of the emergency manual ventilation branch for precisely controlling the tidal volume and inhalation time delivered to the patient during each inhalation. At this time, referring to Figure 1 and Figure 3 as shown, when a pressurizing device is provided in the total inhalation path, the input end of its inhalation valve is connected to the output end of the pressurizing device; referring to Figure 2 and Figure 4 as shown, when a pressurizing device is provided in the air gas source branch, the input end of its inhalation valve is connected to the input end of the total inhalation path or an optional mixing chamber. The third anti-reflux device (including but not limited to a one-way valve, a pneumatic valve, an electric control valve) is used to prevent the gas exhaled by the patient or the condensed water in the circuit from flowing back into the pipeline before the inhalation valve. At this time, referring to Figure 1 and Figure 2As shown, when a third inspiratory flow detection device is provided in the total inspiratory path, the input end of its third anti-reflux device is connected to the rear end of the third inspiratory flow detection device; when no third inspiratory flow detection device is provided in the total inspiratory path, the input end of its third anti-reflux device is connected to the output end of the emergency manual ventilation branch. The third pressure sensing device is used to monitor the airway pressure delivered to the patient and is the basis for implementing various pressure control ventilation modes and pressure alarms. The oxygen concentration detection device is used to monitor in real time the oxygen concentration of the mixed gas finally delivered to the patient. The humidification device is used to heat and humidify the dry medical gas to protect the patient's airway. Therefore, through the above settings, the functions of processing, controlling, and monitoring the inspiratory gas are greatly improved. The mixing chamber ensures the uniformity of the oxygen concentration; the inspiratory valve realizes the accurate delivery of tidal volume; the pressure and oxygen concentration monitoring provide guarantees for safe and effective ventilation; and humidification improves the patient's comfort.

[0043] Furthermore, in an embodiment of the present invention, the emergency manual ventilation branch includes at least one of a quick oxygen switch 51 for controlling on / off and a ventilation device composed of a manual flow regulating device 52 and a third switching device 53. The input end of the emergency manual ventilation branch is connected to the input end of the quick oxygen switch and / or the input end of the manual flow regulating device. The output end of the quick oxygen switch is connected to the output end of the emergency manual ventilation branch. The output end of the manual flow regulating device is connected to the input end of the third switching device. The two output ends of the third switching device are respectively connected to the output end of the emergency manual ventilation branch and the auxiliary output interface. The quick oxygen switch is a quick-opening valve that can instantaneously provide high-flow pure oxygen to the rear end of the total inspiratory path when pressed, and is used for pre-oxygenation in emergency situations or quickly improving hypoxemia. The manual flow regulating device (such as a rotameter) allows the operator to manually set a continuous oxygen flow. The input end of the third switching device (such as a manually operated three-way valve) is connected to the output end of the manual flow regulating device, and its two output ends are respectively connected to the output end of the emergency manual ventilation branch (leading to the total inspiratory path) and the auxiliary output interface 54. The auxiliary output interface can be used to connect other devices that require oxygen. Therefore, through the above settings, multiple emergency manual ventilation guarantees are provided. The quick oxygen switch is suitable for situations that require instantaneous high-flow pure oxygen. The combination of the manual flow regulating device and the third switching device can provide an adjustable and continuous oxygen flow and can flexibly direct this oxygen flow to the patient or external devices.

[0044] Further, in an embodiment of the present invention, the input end of the total exhalation path is connected to the proximal total path and then leads to the patient (i.e., through the exhalation limb of the Y-shaped tube). Specifically, the output end of the total inhalation path and the input end of the total exhalation path are jointly connected to the proximal total path, and then the proximal total path is connected to the patient, that is, the total inhalation path, the total exhalation path, and the proximal total path jointly form a Y-shaped tube structure. The total exhalation path is provided with an exhalation switching device (such as a manually operated two-way three-way valve). The input end of the exhalation switching device (i.e., the exhalation port 61) is connected to the proximal total path, and the output end of the exhalation switching device is respectively connected to the automatic exhalation branch and the manual exhalation branch, which is used to control the total exhalation path to be selectively communicated with the automatic exhalation branch or the manual exhalation branch, so as to realize the flexible switching of different exhalation modes and ensure the monitoring of exhalation parameters. The automatic exhalation branch is provided with a safety valve 71 connected to the output end of the exhalation switching device and an exhalation valve 72 connected to the safety valve. The safety valve is a mechanical spring-loaded safety valve, which can set a maximum pressure limit to prevent the abnormal increase of the pipeline pressure during automatic exhalation. The exhalation valve is usually an electronically controlled PEEP valve, and its opening degree is precisely controlled by the controller to maintain the set PEEP level and allow the patient to exhale, which is used to maintain positive end-expiratory pressure and control the opening of the expiratory phase to prevent alveolar collapse. At this time, the gas exhaled by the patient is discharged after passing through the exhalation valve. The manual exhalation branch is provided with an airbag 81 connected to the output end of the exhalation switching device and an adjustable pressure limiting valve 82 connected to the airbag. The airbag can be the connection part of a reservoir bag, a test lung, or a manual breathing bag. At this time, the operator squeezes the airbag to perform manual assistance or control ventilation. The adjustable pressure limiting valve can be an APL valve, which is used to limit the maximum airway pressure during manual assisted ventilation or spontaneous breathing. During manual ventilation, the operator can set a pressure limit. When the airway pressure exceeds this limit, the APL valve opens to relieve pressure to prevent excessive pressure from damaging the patient's lungs. Therefore, in the manual ventilation mode, the operator squeezes the manual breathing bag connected to the airbag, and the gas exhaled by the patient passes through the manual exhalation branch and is discharged through the adjustable pressure limiting valve. Therefore, through the above settings, the automatic exhalation and manual exhalation functions are more perfect and safe. There is PEEP and safety protection during automatic exhalation, and there is pressure limit protection during manual exhalation, and it is convenient for the operator to ventilate through the airbag.

[0045] Further, in an embodiment of the present invention, the gas path system of the total intravenous anesthesia machine further includes a gas flow detection device 62. The gas flow detection device is arranged in the total exhalation path and connected to the input end of the exhalation switching device, or arranged in the proximal total path jointly connected to the total inhalation path and the total exhalation path. As shown in Figures 1-7 the gas flow detection device is arranged in the total exhalation path and connected to the input end of the exhalation switching device. At this time, the gas flow detection device is used to measure parameters such as the tidal volume and minute ventilation volume exhaled by the patient. As shown in Figure 8As shown, the gas flow detection device is arranged in the proximal main path jointly connected to the inspiratory main path and the expiratory main path. At this time, the gas flow detection device can measure the gas flow delivered from the inspiratory main path to the patient and the gas flow exhaled by the patient into the expiratory main path, so as to detect parameters such as the tidal volume and minute ventilation volume inhaled and exhaled by the patient accordingly.

[0046] Among them, in the embodiment of the present invention, the gas path system of the total intravenous anesthesia machine mainly has three ventilation working modes: mechanical ventilation mode, manual ventilation mode, and emergency ventilation mode. In the mechanical ventilation mode, the above-mentioned inspiratory gas path provides oxygen in any one of the above five oxygen supply modes, and the expiratory gas path performs expiration through the automatic expiratory branch by controlling the expiratory switching device, so that full-automatic mechanical ventilation can be realized. For example, the mixed gas after mixing and boosting by the high-pressure oxygen branch and the oxygen gas source branch can be delivered to the patient, or the mixed gas after mixing and boosting by the low-pressure oxygen branch and the oxygen gas source branch can be delivered to the patient, etc. Its specific value can be determined according to the actual use scenario and the oxygen concentration required by the patient, and no specific limitation is made here. At this time, through the combined action of the boosting device and the inspiratory valve, a constant flow rate output of the mixed gas can be achieved, so that the total intravenous anesthesia machine can also effectively utilize the low-pressure oxygen source and ambient air, and is no longer limited to places where a high-pressure gas source must be available. Then, the gas exhaled by the patient after breathing is exhaled automatically through the safety valve and the expiratory valve in the automatic expiratory branch. In the manual ventilation mode, the above-mentioned inspiratory gas path provides oxygen in any one of the above five oxygen supply modes, and the expiratory gas path performs expiration through the manual expiratory branch by controlling the expiratory switching device, so that manual ventilation can be realized. For example, the mixed gas after mixing and boosting by the above-mentioned low-pressure oxygen branch and the oxygen gas source branch can be delivered to the patient, etc. At this time, through the boosting device and the inspiratory valve, a constant flow rate ventilation of the mixed gas can be achieved, and then the gas exhaled by the patient after breathing is used to perform manual ventilation for the patient through the airbag and the adjustable pressure limiting valve in the manual expiratory branch. In the emergency ventilation mode, the above-mentioned inspiratory gas path provides oxygen through the emergency manual ventilation branch, and the expiratory gas path performs expiration through the manual expiratory branch by controlling the expiratory switching device, so that full-autonomous manual ventilation can still be realized even when the total intravenous anesthesia machine loses power.

[0047] In summary, for the gas path system of the total intravenous anesthesia machine in the above embodiments of the present invention, by integrating a pressurizing device into the air gas source branch or the total inhalation path, and optimizing the oxygen gas source branch to be compatible with high-pressure oxygen sources and low-pressure oxygen sources, the pressurizing device ensures that low-pressure oxygen sources or normal-pressure gas sources can be stably sucked and pressurized to the working pressure, enabling the total intravenous anesthesia machine to effectively utilize low-pressure oxygen sources and ambient air, and no longer being limited to places where high-pressure gas sources are necessary, significantly improving the applicability and deployment flexibility of the device in different medical environments; at the same time, in cooperation with the inhalation flow detection devices and flow regulating devices provided at least at two of the oxygen gas source branch, the air gas source branch, and the total inhalation path, precise metering and on-demand mixing of gases from different sources are achieved, ensuring accurate control of the inhaled oxygen concentration and tidal volume; and by connecting the output ends of the oxygen gas source branch and the air gas source branch to the total inhalation path, combined with precise flow regulation and monitoring, it is ensured that oxygen and air can be fully mixed and delivered to the patient with a stable flow rate and a set oxygen concentration, improving the quality of ventilation treatment; and by setting a flow direction control component, the high-pressure oxygen branch and the low-pressure oxygen branch are effectively isolated, preventing unwanted backflow or pressure shock of gases between gas sources of different pressure levels, protecting the gas source equipment, and ensuring the stability of the supply pressure and the purity of the gas components; and the independently designed emergency manual ventilation branch can be optionally equipped with a fast oxygen switch (for quickly delivering high-flow pure oxygen) and / or a ventilation device composed of a manual flow regulating device and a third switching device (which can provide an adjustable continuous oxygen flow and can be directed to the patient or an auxiliary output interface), ensuring that life support can be quickly provided to the patient in case of an emergency, improving the operation convenience and the ability to respond to emergencies; and the exhalation switching device can control the connection between the total exhalation path and the automatic exhalation branch (including a safety valve and an exhalation valve) or the manual exhalation branch (including an airbag and an adjustable pressure limiting valve), enabling the total intravenous anesthesia machine to automatically switch the exhalation path according to the ventilation mode, or providing necessary pressure limitation during manual ventilation, ensuring the effectiveness of exhalation management in different modes and improving the operation safety; at the same time, various sensors such as pressure sensing devices, inhalation flow detection devices, gas flow detection devices, and oxygen concentration detection devices are provided at key nodes of the gas path (such as the high-pressure oxygen branch, the low-pressure oxygen branch, the air branch, the total inhalation path, the total exhalation path). These sensors, in cooperation with the controller, can real-time monitor various parameters during the ventilation process, providing a data basis for realizing precise closed-loop control, timely alarm, and fault diagnosis, and improving the intelligent level of the total intravenous anesthesia machine and the safety of clinical use; solving the problem that the existing technology cannot efficiently integrate and utilize low-pressure oxygen sources and ambient air.

[0048] The embodiment of the present invention also provides a total intravenous anesthesia machine. Refer to Figures 1-8As shown, the total intravenous anesthesia machine includes the gas path system of the total intravenous anesthesia machine in the above embodiment and the controller 10. The controller is usually an electronic control unit based on a microprocessor (MCU) or a programmable logic controller (PLC), and the controller is electrically connected or communicatively connected to various sensors (flow rate, pressure, oxygen concentration, etc.) and actuators (flow rate regulating device, pressurizing device, inhalation valve, exhalation valve, etc.) in the gas path system of the total intravenous anesthesia machine. At this time, the controller receives sensor data, and according to the ventilation mode and parameters set by the user, controls the actions of the actuators through precise algorithms, so as to achieve safe and effective mechanical ventilation support for the patient. The controller is also responsible for functions such as human-machine interaction (displaying parameters, waveforms, alarm information, receiving user input, etc.), alarm handling, and data recording.

[0049] Specifically, the controller periodically reads the values of all sensors related to pressure, flow rate, and oxygen concentration described above, and parses the parameter settings of the user through the interface (such as ventilation mode, tidal volume, respiratory rate, I:E ratio, FiO2, PEEP, etc.). Then, it automatically selects the high-pressure oxygen mode or the low-pressure oxygen mode according to the user's selection or sensor feedback (such as the pressure of the high-pressure oxygen source). Then, according to the set FiO2 and the feedback of the oxygen concentration detection device, it adjusts the opening degree of the flow rate regulating device and / or the rotation speed of the pressurizing device; according to the set tidal volume / minute ventilation volume and the feedback of the inspiratory flow rate sensor, it adjusts the flow rate regulating device and / or the pressurizing device; according to the set inspiratory pressure and the feedback of the third pressure sensor, it adjusts the output of the pressurizing device; according to the set PEEP and the feedback of the third pressure sensor at the end of exhalation, it adjusts the opening degree of the exhalation valve, etc. Thus, it realizes precise control of the start and stop and duration of phases such as inspiration, expiration, and inspiratory pause.

[0050] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0051] The above-described embodiments only represent several implementation manners of the present invention, and the description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A total intravenous anesthesia machine gas path system, characterized in that, It includes an inspiratory gas path for delivering breathing gas to a patient and an expiratory gas path for guiding the exhaled gas of the patient; The inspiratory gas path includes an oxygen gas source branch, an air gas source branch, an inspiratory main path, and an emergency manual ventilation branch. The expiratory gas path includes an expiratory main path, an automatic expiratory branch, and a manual expiratory branch; The oxygen gas source branch includes a high-pressure oxygen branch, a flow rate regulating device connected to the output end of the high-pressure oxygen branch, and a low-pressure oxygen branch whose output end is connected to the front end or the rear end of the flow rate regulating device. The flow rate regulating device is used to regulate at least a part of the oxygen flow rate passing through the oxygen gas source branch; The inspiratory main path is respectively connected to the output ends of the oxygen gas source branch and the air gas source branch, and is used to mix the gases respectively delivered by the oxygen gas source branch and the air gas source branch, and form a mixed gas to be delivered to the patient; The emergency manual ventilation branch is respectively connected to the oxygen gas source branch and the inspiratory main path, and is used to provide manual ventilation to the patient under preset conditions; The expiratory main path is provided with an expiratory switching device. Two output ends of the expiratory switching device are respectively connected to the automatic expiratory branch and the manual expiratory branch, and are used to control the expiratory main path to be selectively communicated with the automatic expiratory branch or the manual expiratory branch; Wherein, a flow direction control component is further provided in the high-pressure oxygen branch and the low-pressure oxygen branch for controlling the oxygen flow direction in the high-pressure oxygen branch and the low-pressure oxygen branch; At least two of the oxygen gas source branch, the air gas source branch, and the inspiratory main path are provided with inspiratory flow rate detection devices for detecting the gas flow rate at corresponding positions; A pressurizing device is provided in the air gas source branch or the inspiratory main path for pressurizing the gas from the air gas source branch, or pressurizing the mixed gas after mixing the oxygen gas source branch and the air gas source branch.

2. The total intravenous anesthesia machine gas path system according to claim 1, characterized in that The front end of the emergency manual ventilation branch is connected to the front end of the flow rate regulating device, and the rear end of the emergency manual ventilation branch is connected to the input end of the inspiratory main path, or the rear end of the pressurizing device, or the front end of the inspiratory flow rate detection device.

3. The total intravenous anesthesia machine gas circuit system according to claim 1, characterized in that, The flow direction control component includes a first anti-reflux device connected to the input end of the high-pressure oxygen branch and a second anti-reflux device connected to the input end of the low-pressure oxygen branch. The output end of the second anti-reflux device is connected to the front end or the rear end of the flow rate regulating device.

4. The total intravenous anesthesia machine gas path system according to claim 1, characterized in that, The flow direction control component is a first switching device provided at the output ends of the high-pressure oxygen branch and the low-pressure oxygen branch and converging to the front end of the flow rate regulating device. Two input ends of the first switching device are respectively connected to the output ends of the high-pressure oxygen branch and the low-pressure oxygen branch, and the output end of the first switching device is connected to the front end of the flow rate regulating device.

5. The total intravenous anesthesia machine gas path system according to claim 3, characterized in that, A second switching device is further provided in the low-pressure oxygen branch. The output end of the second anti-reflux device is connected to the input end of the second switching device. Two output ends of the second switching device are respectively connected to the front end and the rear end of the flow rate regulating device.

6. The total intravenous anesthesia machine gas circuit system according to any one of claims 1-5, characterized in that, The high-pressure oxygen branch further includes at least one of a first filtering device, a first pressure sensing device, and a first pressure regulating device arranged in sequence, and the low-pressure oxygen branch further includes a second filtering device.

7. The total intravenous anesthesia machine gas path system according to any one of claims 1-5, characterized in that The air gas source branch further includes at least one of a third filtering device, a fourth filtering device, and a second pressure sensing device arranged in sequence.

8. The total intravenous anesthesia machine gas circuit system according to any one of claims 1-5, characterized in that, The total inhalation path further includes at least one of a mixing chamber, an inhalation valve, a third anti-reflux device, a third pressure sensing device, an oxygen concentration detection device, and a humidifying device arranged in sequence, and the output ends of the oxygen gas source branch and the air gas source branch are both connected to the mixing chamber.

9. The total intravenous anesthesia machine gas path system according to any one of claims 1-5, characterized in that, The emergency manual ventilation branch includes at least one of a quick oxygen switch for controlling on / off and a ventilation device composed of a manual flow regulating device and a third switching device. The input end of the emergency manual ventilation branch is connected to the input end of the quick oxygen switch and / or the input end of the manual flow regulating device. The output end of the quick oxygen switch is connected to the output end of the emergency manual ventilation branch. The output end of the manual flow regulating device is connected to the input end of the third switching device. The two output ends of the third switching device are respectively connected to the output end of the emergency manual ventilation branch and an auxiliary output interface.

10. The total intravenous anesthesia machine gas path system according to any one of claims 1-5, characterized in that, An air release valve connected to the output end of the exhalation switching device and an exhalation valve connected to the air release valve are provided on the automatic exhalation branch, and an air bag connected to the output end of the exhalation switching device and an adjustable pressure limiting valve connected to the air bag are provided on the manual exhalation branch.

11. The total intravenous anesthesia machine gas path system according to any one of claims 1-5, characterized in that, The total intravenous anesthesia machine gas path system further includes a gas flow detection device, which is arranged in the total exhalation path and connected to the input end of the exhalation switching device, or arranged in the proximal total path commonly connected to the total inhalation path and the total exhalation path.

12. A total intravenous anesthesia machine, characterized in that, It includes the total intravenous anesthesia machine gas path system as described in any one of claims 1-11 and a controller.

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