Anesthesia machine circuit condensate automatic drainage and bacterial filtration system

Abstract

The application discloses an anesthesia machine loop condensate water automatic discharge and bacterial filtration system, and relates to the technical field of intelligent management and control system of anesthesia equipment, which comprises a condensate water collecting module, a drainage triggering module, a gas-liquid separation module, a bacterial filtration module and a gas phase reflux module. The application collects condensate water in a directional way, cooperates with the drainage triggering mechanism matched with the ventilation phase, dynamically adjusts the drainage determination condition, automatically completes the collection and discharge of the accumulated water in the whole process without manual operation, keeps the inside of the loop dry and clean, and avoids the safety risk caused by the accumulated water. Meanwhile, the links of gas-liquid separation, hierarchical bacterial filtration and gas phase reflux treatment are connected in series, the waste liquid storage unit has the full-overflow self-locking prompting function, and the filter material blockage can switch the standby passage. The purified anesthetic gas is self-adaptively refluxed and unidirectionally limited in flow, which not only reduces the consumption of the medicament and the indoor waste gas pollution, but also stabilizes the loop gas parameters, and guarantees the smooth and safe anesthesia ventilation process.

Description

Technical Field

[0001] This invention relates to the field of intelligent control system technology for anesthesia equipment, specifically an automatic condensate drainage and bacterial filtration system for anesthesia machine circuits. Background Technology

[0002] In clinical anesthesia, the anesthesia machine's breathing circuit continuously delivers a heated and humidified anesthetic gas mixture. The patient's exhaled gas has a higher temperature and humidity, creating a temperature difference with the low-temperature environment of the circuit walls and connectors, easily leading to the formation of large amounts of condensate. This accumulated condensate poses multiple clinical risks: droplets carried by the airflow can easily cause coughing and irritate the patient's airway; and long-term retention of condensate can breed bacteria and fungi, significantly increasing the risk of postoperative lung infections. Currently, the standard practice in operating rooms is to manually empty the condensate at regular intervals, relying on medical staff's subjective judgment of when to drain it. Furthermore, the discharged waste liquid contains volatile gases containing anesthetic drugs, and direct discharge wastes anesthetic agents and pollutes the air inside the operating room. Clinically, there is a lack of an integrated system that can autonomously collect condensate, automatically drain it, separate the gas and liquid, sterilize and filter it, and recover the anesthetic drugs. The entire process relies on manual intervention, resulting in significant deficiencies in operational stability and medical safety.

[0003] Existing anesthesia machine circuit condensate treatment devices only have simple collection containers without directional flow guidance structures. Condensate easily adheres to the walls and accumulates. Liquid level monitoring uses a fixed sampling frequency, which cannot accurately monitor condensate under different patient ventilation states. Most drainage devices lack dynamic liquid level determination logic, relying solely on fixed thresholds to trigger drainage. They do not consider the impact of ambient temperature differences and patient tidal volume changes on the rate of condensate formation, easily leading to untimely drainage or frequent empty drainage. Routine drainage actions are not constrained by respiratory phase; opening the drainage path during inspiration disrupts circuit pressure and interferes with patient ventilation. Traditional equipment only performs simple gas-liquid separation without a graded sterilization filtration structure, failing to completely trap microorganisms entrained in the waste liquid. Furthermore, the separated anesthetic-containing waste gas is directly discharged without an adaptive reflux adjustment mechanism, failing to dynamically recover gas based on circuit anesthetic concentration. Additionally, the collection tank lacks an automatic locking mechanism when overflowing, and there is no backup path switching after filter blockage, significantly reducing circuit safety with continued use.

[0004] In summary, existing anesthesia machine circuit condensate treatment equipment has limited functionality, with each treatment stage operating independently and lacking coordinated control logic. This prevents the simultaneous implementation of automatic condensate collection, precise time-based drainage, gas-liquid stratified purification, microbial interception, and anesthetic gas recycling. Manual operation increases the workload for medical staff, while fixed parameter control is ill-suited to the ventilation conditions of different surgeries and patients. Problems such as bacterial growth from condensate accumulation, anesthetic gas leakage, and erratic ventilation parameters are difficult to address at their source. To address these challenges, this invention designs an integrated system combining five functional modules: condensate collection, drainage triggering, gas-liquid separation, bacterial filtration, and gas-phase reflux. Through multi-dimensional dynamic calculations and phased control logic, it comprehensively solves the shortcomings of traditional equipment, improving the operational stability of the anesthesia circuit and enhancing the safety of operating room procedures. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide an automatic condensate drainage and bacterial filtration system for anesthesia machine circuits. This system relies on spiral flow to collect accumulated water and monitors the liquid level in conjunction with the ventilation rhythm. Based on a dynamic liquid level threshold, it only drains water at the end of expiration; it stratifies and traps liquid, locking the upstream pipeline when the waste tank overflows; it provides two-stage purification, allowing switching to a backup path if the filter material becomes clogged; it adaptively adjusts the return flow rate, unidirectional flow restriction prevents gas backflow, and the purified anesthetic gas is returned to the circuit for recycling. The entire process is automated, balancing ventilation stability, sterilization, and anesthetic drug recovery.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: an automatic condensate drainage and bacterial filtration system for an anesthesia machine circuit, the system comprising: Condensation and water collection module: acquires the operating data of the anesthesia machine's breathing circuit, collects the internal gas temperature and humidity parameters and condensate generation status, performs directional collection and control of condensate, completes real-time monitoring of condensate storage, and synchronously pushes the condensate storage data to the drainage trigger module. Drainage trigger module: Receives condensate storage data, combines it with loop ventilation phase information to execute drainage path on / off control, outputs drainage execution signal to gas-liquid separation module, and completes the phased discharge control of condensate. Gas-liquid separation module: Responds to drainage execution signal, receives the discharged gas-liquid mixture, performs gas-liquid two-phase separation control, introduces liquid waste liquid into waste liquid storage unit, and delivers the separated gas phase containing anesthetic drugs to bacterial filtration module; Bacterial filtration module: Receives gas phase containing anesthetic drugs, performs graded sterilization filtration control, intercepts microorganisms and particulate impurities in the gas phase, and delivers the purified gas phase to the gas phase reflux module; Gas phase reflux module: Receives the purified gas phase, performs reflux flow control, and delivers the purified gas phase containing anesthetic drugs back to the inhalation branch of the anesthesia machine to complete the anesthetic drug recycling control.

[0007] Furthermore, the condensate collection module incorporates a spiral flow control logic, guiding the flow direction of condensate along a continuous spiral path. This guides the droplets condensed on the inner wall of the guide loop to converge towards the bottom collection area along a preset path. The preset path is a spiral flow guidance channel pre-designed and machined onto the flow guide structure of the condensate collection module. Simultaneously, the sampling frequency for monitoring the liquid level in the collection area is set, and the sampling interval is adjusted to match the loop's ventilation rhythm. The sampling density is increased during exhalation, while the basic sampling frequency is maintained during inhalation. Simultaneously, hydrophobic surface condition control is implemented, adjusting the temperature distribution on the guide path wall based on the condensate retention time. Temperature changes alter the equivalent wetting contact angle of the droplets on the wall surface, controlling the adhesion and flow resistance of the droplets and ensuring they maintain directional flow, preventing them from remaining in non-collection areas for extended periods.

[0008] Furthermore, the drainage triggering module uses dynamic threshold calculation logic to determine the drainage triggering conditions, and the calculation formula is as follows: ,in, The liquid level threshold is triggered by dynamic drainage; The temperature of the gas inside the circuit; Operating room ambient temperature; The cumulative tidal volume per minute; The basic liquid level threshold; This is the temperature influence coefficient. The tidal volume influence coefficient. and All are positive numbers. Weights used to characterize the effect of temperature difference on condensate production The weighting of the influence of tidal volume on the condensate generation rate is used to characterize the drainage triggering liquid level threshold obtained in real time; the drainage triggering determination is based on the dynamic drainage triggering liquid level threshold obtained in real time.

[0009] Furthermore, the drainage trigger module incorporates ventilation phase matching logic to identify the inspiratory and expiratory phases of the breathing circuit in real time, limiting the drainage action execution window to the end of the expiratory phase while maintaining the drainage pathway closed throughout the inspiratory phase. Simultaneously, it implements drainage duration control, matching the corresponding drainage duration based on the current condensate level; the higher the condensate level, the longer the drainage duration. After the drainage action is completed, it automatically resets the pathway status and simultaneously sends a fluid arrival pre-notification signal to the gas-liquid separation module to ensure that downstream modules enter the processing state in advance.

[0010] Furthermore, the gas-liquid separation module incorporates multi-layered staggered interception and control logic, setting up multi-layered inclined interception paths. When the gas-liquid mixture flows along these paths, liquid droplets, after being blocked, will flow downwards along the surface of the interception path into the waste liquid storage unit, while the gaseous fluid flows upwards along the gaps in the paths into the bacterial filtration module. Simultaneously, wall condensate diversion control is implemented, with an annular diversion path set up on the wall within the separation area to guide the condensed droplets on the wall along the diversion path into the waste liquid storage unit, preventing the droplets accumulated on the wall from being re-entrained into the gas phase area by the airflow.

[0011] Furthermore, the gas-liquid separation module is equipped with waste liquid storage control logic to manage the on / off state of the inlet passage of the waste liquid storage unit. Under normal circumstances, the inlet passage remains closed. Only when liquid waste liquid is input from upstream will the inlet passage be opened under the fluid pressure of the liquid waste liquid. After the waste liquid flows in, the inlet passage automatically returns to the closed state. Simultaneously, waste liquid level monitoring and control are performed, and the waste liquid capacity data in the waste liquid storage unit is collected in real time. When the rated capacity limit is reached, a replacement prompt is triggered, and the upstream drainage passage is locked at the same time. After the replacement is completed and the sealing verification is passed, the upstream passage lock is automatically released.

[0012] Furthermore, the bacterial filtration module incorporates a hierarchical filtration control logic, setting up a two-stage filtration process: the first stage performs pre-filtration control, intercepting tiny droplets and large particles entrained in the gas phase; the second stage performs sterilization filtration control, intercepting microorganisms and fine-particle impurities in the gas phase. Simultaneously, filter layer status monitoring control is performed, collecting pressure difference data before and after filtration, judging the filter layer blockage status based on pressure difference changes, and triggering a filter layer replacement prompt when the pressure difference reaches a set threshold, and switching to a backup filtration path to maintain uninterrupted gas phase purification.

[0013] Furthermore, the gas-phase reflux module employs adaptive flow regulation logic to control the reflux flow rate, calculated using the following formula: ,in, For real-time return traffic; Basic return flow; Set the concentration of anesthetic gas for the circuit; Real-time concentration of anesthetic gas in the circuit; This is the concentration deviation adjustment coefficient, and >0 is used to characterize the adjustment range of anesthetic gas concentration deviation on reflux flow rate, with a value range of 0.5 to 2.0 L·min⁻¹ / %; the flow capacity of the passage is adjusted based on the real-time reflux flow rate calculated in real time.

[0014] Furthermore, the gas phase reflux module incorporates unidirectional flow restriction control logic, setting a unidirectional flow path for the gas phase fluid. It only allows the purified gas phase to flow from the filter side to the inspiratory branch of the anesthesia machine, and reverse airflow triggers a pathway locking mechanism. Simultaneously, it performs flow limit control, setting a maximum threshold for reflux flow. When the actual reflux flow exceeds the maximum threshold, it automatically reduces the flow area of ​​the pathway to limit the reflux flow within a safe range, preventing excessive reflux flow from interfering with the normal gas parameters of the breathing circuit.

[0015] Compared with existing technologies, this automatic condensate drainage and bacterial filtration system for anesthesia machine circuits has the following advantages: I. This invention achieves directional collection and dynamic level monitoring of condensate in the circuit by setting up an independent condensate collection module. Relying on a spiral flow guide structure and wall temperature control, it reduces droplet adhesion and retention. At the same time, it adjusts the level sampling density according to the ventilation rhythm, which can continuously concentrate the condensate generated on the inner wall of the circuit to a designated area and avoid water accumulation. With the drainage trigger mechanism matched to the respiratory phase, the drainage process is initiated only at the end of expiration, avoiding interference with the circuit ventilation status caused by drainage during the inspiration phase. At the same time, it calculates the dynamic drainage level threshold by combining multi-dimensional variables to adapt to the water generation rate under different ambient temperatures and patient ventilation volumes, so as not to cause water overflow or ineffective drainage. The entire water collection and drainage process is fully automatic, without the need for medical staff to check and manually empty it, reducing clinical operation input, and can also continuously maintain a dry and clean operating environment inside the anesthesia machine's respiratory circuit, reducing various safety hazards caused by long-term water retention.

[0016] II. This invention utilizes a complete treatment chain consisting of sequential gas-liquid separation, bacterial filtration, and gas-phase reflux to treat the gas-liquid mixture generated from drainage in layers. Liquid waste is collected and managed separately. When the storage container reaches its maximum capacity, the upstream pipeline is automatically locked and a replacement reminder is issued to prevent waste liquid from overflowing and contaminating the equipment and operating room environment. The two-stage filtration structure can progressively intercept droplets, particulate matter, and various microorganisms. Changes in filtration pressure differential are monitored in real time, and the backup path is automatically switched when the filter material becomes clogged, ensuring that the gas purification process is not interrupted. The purified gas containing anesthetic agents is returned to the inhalation branch through an adaptive flow regulation structure. The reflux delivery volume is adjusted according to the actual drug concentration in the circuit, and a unidirectional flow restriction structure is used to prevent backflow of airflow. This reduces anesthetic agent consumption and indoor exhaust pollution while stabilizing the gas parameters inside the circuit, ensuring a smooth and safe anesthesia process for the patient.

[0017] Other advantages, objectives and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be learned from the practice of the invention. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0019] Figure 1 This is a diagram of the overall modules of this system; Figure 2 This is the condensate collection and drainage triggering flowchart for this system; Figure 3 This is a flow chart of the gas-liquid separation-filtration-gas phase reflux process of this system. Detailed Implementation

[0020] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0021] Example 1: This embodiment discloses an automatic condensate drainage and bacterial filtration system for an anesthesia machine circuit. Addressing the problem of condensation (condensation of warm, humid gas against the walls), which easily breeds microorganisms and causes anesthetic drug loss in the closed-loop breathing circuit of anesthesia machines, the system incorporates five functional units: a condensate collection module, a drainage triggering module, a gas-liquid separation module, a bacterial filtration module, and a gas-phase recirculation module. Through a complete process of directional condensate collection, dynamic matching of breathing phase drainage, gas-liquid two-phase separation, graded sterilization and purification, and anesthetic gas-phase recirculation and reuse, the system achieves fully automatic condensate collection and drainage and safe gas-phase circulation in the circuit. This avoids the risk of circuit infection caused by condensate, improves the utilization rate of anesthetic drugs, and reduces drug consumption and environmental pollution during anesthesia.

[0022] After being connected to the anesthesia machine's breathing circuit, this system starts synchronously with the anesthesia machine's ventilation operation. Each module works in coordination according to the breathing sequence. The complete operation process is as follows: The condensate collection module is installed in the condensation-prone section of the breathing circuit. It first acquires real-time circuit operation data through built-in temperature and humidity sensors and a liquid level acquisition unit, continuously collecting internal gas temperature, relative humidity parameters, and the generation and storage status of condensate. The module incorporates a spiral flow control logic. A continuous spiral flow guide channel is machined into the inner wall of the module as a preset flow path. Droplets formed by condensation due to temperature differences on the inner wall of the circuit flow downwards along the spiral guide channel under the shearing action of their own gravity and the expiratory airflow, gradually converging towards the collection area at the bottom of the module, preventing droplets from randomly distributing and lingering on the circuit wall. Simultaneously, the module controls the sampling frequency for liquid level monitoring in the collection area, dynamically adjusting the sampling interval to match the circuit's ventilation rhythm. During the exhalation phase, the airflow velocity and warm, humid gas flow rate within the loop are high, resulting in rapid condensate formation and more significant liquid level changes. Therefore, increasing the liquid level sampling density and shortening the sampling interval are crucial for timely capture of dynamic changes in the liquid level. During the inhalation phase, the airflow direction changes, the condensate formation rate slows down, and the liquid level becomes relatively stable. Therefore, maintaining the basic sampling frequency reduces the data processing load while ensuring monitoring effectiveness. The module simultaneously manages the hydrophobic surface condition and tracks the condensate retention time on the wall in real time. When the retention time of droplets on the guide path wall exceeds the normal range of 0-15 seconds, the module adjusts the temperature distribution on the guide path wall. This temperature change alters the equivalent wetting contact angle of the droplets on the wall. As the contact angle increases, the contact area between the droplets and the wall decreases, reducing droplet adhesion and flow resistance, thus restoring directional flow. This mechanism prevents droplets from adhering to non-collection areas for extended periods, reducing the formation of liquid films on the wall and improving condensate collection efficiency. The module synchronously pushes the real-time collected condensate volume data to the downstream drainage trigger module, providing data support for drainage control.

[0023] After receiving condensate level data from upstream, the drainage trigger module combines this data with loop ventilation phase information to control the on / off state of the drainage path. The module uses dynamic threshold calculation logic to determine the drainage trigger conditions, calculating the current dynamic drainage trigger level threshold based on real-time operating parameters. The calculation formula is as follows: ,in, The liquid level threshold is the liquid level criterion for triggering dynamic drainage, and it serves as the liquid level determination criterion for triggering drainage action. The temperature of the gas inside the circuit. The temperature difference between the operating room and the ambient temperature directly determines the thermodynamic driving force for water vapor condensation. The greater the temperature difference, the higher the amount of condensate generated per unit time. The cumulative tidal volume per minute reflects the total amount of warm and humid gas flowing through the circuit per unit time. The larger the tidal volume, the more water vapor it carries, and the faster the condensation rate. The base level threshold is the set baseline drainage level. This is the temperature influence coefficient. The coefficients representing the influence of tidal volume are both positive. Weights used to characterize the effect of temperature difference on condensate production The weighting coefficients used to characterize the influence of tidal volume on the condensate formation rate can be pre-calibrated based on the circuit structure and operating environment. The core logic of this formula is that when the temperature difference between the circuit and the environment increases, or the patient's tidal volume rises, the condensate formation rate increases, and the dynamic threshold rises accordingly. This appropriately extends the drainage interval, preventing excessively frequent drainage actions from interfering with the circuit's airflow. Conversely, when the temperature difference decreases and the tidal volume decreases, the condensation rate decreases, and the dynamic threshold decreases accordingly, ensuring timely drainage of accumulated water and preventing prolonged retention and bacterial growth. The module compares real-time collected liquid level data with the calculated dynamic threshold. When the condensate level reaches the threshold, a drainage action is triggered. The module incorporates ventilation phase matching logic, which identifies the inspiratory and expiratory phases of the respiratory circuit in real time through circuit flow or pressure signals. This strictly limits the drainage action execution window to the end of the expiratory phase, while maintaining the drainage pathway closed throughout the inspiratory phase. The reason for this design is that the pressure in the circuit is relatively stable and the airflow velocity is low at the end of expiration, so opening the drainage path at this time has minimal interference with the circuit's pressure and airflow parameters. If the drainage path is opened during the inspiratory phase, it will cause inspiratory airflow leakage, affecting the accuracy of tidal volume and the stability of anesthetic gas concentration. Simultaneously, the module implements drainage duration control, matching the drainage duration to the current condensate level. The higher the condensate level, the longer the drainage duration, ensuring complete drainage of accumulated water while preventing excessive gas phase loss during drainage. After the drainage action is completed, the module automatically resets the drainage path to the closed state and simultaneously sends a fluid arrival pre-notification signal to the gas-liquid separation module, causing the downstream module to enter a standby state in advance, ensuring that the separation process can respond immediately when fluid enters.

[0024] The gas-liquid separation module receives the gas-liquid mixture discharged from the drainage channel and performs gas-liquid two-phase separation control. The module incorporates multi-layered staggered interception control logic, setting up multiple inclined interception paths inside the separation chamber. Adjacent interception layers are staggered, causing the gas-liquid mixture to flow along a tortuous inclined path. During the flow, liquid water droplets, due to their larger mass and stronger inertia, lose kinetic energy upon impacting the interception path surface and flow downwards along the interception path surface under gravity, eventually flowing into the waste liquid storage unit at the bottom. The gas phase fluid, with its smaller mass and easier flow direction, flows upwards along the gaps in the interception path and enters the downstream bacterial filtration module. Simultaneously, the module performs wall condensation diversion control, setting up a ring-shaped diversion path on the inner wall of the separation area. Droplets condensed on the inner wall of the separation chamber due to temperature differences flow downwards along the ring-shaped diversion path into the waste liquid storage unit, preventing droplets accumulated on the wall from being re-entrained into the gas phase region by the rising airflow, thus improving the overall efficiency of gas-liquid separation. The module is equipped with waste liquid storage control logic to manage the on / off state of the inlet passage of the waste liquid storage unit. Under normal conditions, the inlet passage remains closed, blocking gas-liquid exchange between the waste liquid storage unit and the separation chamber, preventing volatile components in the waste liquid from flowing back into the gas phase. Only when liquid waste liquid is input upstream does the fluid pressure of the liquid waste liquid overcome the closing elasticity of the passage, opening the inlet passage. After the waste liquid flows into the storage unit, the fluid pressure drops, and the inlet passage automatically returns to its closed state. The module simultaneously performs waste liquid volume monitoring and control, collecting real-time waste liquid volume data in the waste liquid storage unit. When the waste liquid volume reaches the rated capacity limit of 150mL, a replacement prompt signal is triggered, and the upstream drainage passage is locked to prevent waste liquid overflow and circuit contamination. After replacing the waste liquid storage unit and completing the sealing verification, the system automatically releases the lock on the upstream passage and restores the normal drainage process.

[0025] The bacterial filtration module receives the anesthetic-containing gas phase output after gas-liquid separation and performs graded sterilization filtration control. The module has built-in graded filtration control logic, setting up a two-stage filtration process: the first stage performs pre-filtration control, using porous hydrophobic filter media to trap tiny droplets and large-particle impurities entrained in the gas phase, preventing droplets from wetting the downstream sterilization filter layer, while also blocking large particles and protecting the secondary filter media; the second stage performs sterilization filtration control, using high-precision sterilization filter media to trap bacteria, fungi, and other microorganisms and fine-particle impurities in the gas phase, achieving biological purification of the gas phase. The module simultaneously performs filter layer status monitoring control, with pressure acquisition units set on both the inlet and outlet sides of the filter layer to collect real-time pressure difference data before and after filtration. Under normal operating conditions, the filter bed pressure difference remains within a stable range. As the filter bed gradually becomes clogged due to impurities, the filtration resistance increases and the pressure difference gradually increases. When the pressure difference reaches the set threshold of 1.2 kPa, a filter bed replacement prompt is triggered. At the same time, the system automatically switches to the backup filtration path, which continues to perform gas phase purification, ensuring that the gas phase purification process is not interrupted and avoiding system shutdown due to filter bed replacement.

[0026] The gas phase reflux module receives the purified gas phase, controls the reflux flow rate, and returns the purified gas phase containing anesthetic drugs to the inspiratory branch of the anesthesia machine, achieving drug recycling. The module uses adaptive flow regulation logic to control the reflux flow rate; the calculation formula is as follows: ,in, The real-time return flow rate is the actual ventilation flow rate of the return path; The base reflux flow rate is the minimum reflux flow rate set by the system to ensure the basic gas phase circulation volume. Setting the concentration of anesthetic gas for the circuit is the target drug concentration preset during the anesthesia process; The real-time concentration of anesthetic gas in the circuit is collected in real time by the circuit concentration sensor. This is the concentration deviation adjustment coefficient, and A value greater than 0 characterizes the adjustment range of the anesthetic gas concentration deviation on the reflux flow rate. The larger the coefficient, the greater the flow rate adjustment for the same concentration deviation. The principle of this adjustment logic is that when the real-time anesthetic gas concentration in the loop... Below the set concentration At that time, the concentration deviation was positive, and the real-time reflux flow rate was... The module increases the base flow rate to return more purified gas containing anesthetic to the inspiratory branch, replenishing the anesthetic concentration in the circuit. When the real-time concentration exceeds the set concentration, the concentration deviation is negative, and the return flow rate decreases accordingly, reducing the need for anesthetic replenishment and helping to maintain a stable anesthetic concentration in the circuit. Based on the real-time calculated return flow rate, the module adjusts the flow capacity of the return path to achieve precise flow control. The module incorporates unidirectional flow restriction logic, setting a unidirectional conduction structure in the return path to allow only purified gas to flow from the filter side to the inspiratory branch of the anesthesia machine. If reverse airflow occurs, a path locking mechanism is triggered to prevent fresh gas from the inspiratory branch from flowing back into the filter module, avoiding anesthetic leakage and circuit parameter malfunction. Simultaneously, a flow limit control is implemented, setting a maximum return flow rate threshold of 8 L / min. When the actual return flow rate exceeds this maximum threshold, the module automatically reduces the flow area, limiting the return flow rate to a safe range of 2 L / min to 6 L / min, preventing excessive return flow from interfering with the normal gas parameters and pressure state of the breathing circuit.

[0027] The system described in this embodiment constructs a complete closed loop of condensate collection, drainage, separation, filtration, and reflux through the sequential coordinated operation of five modules, achieving fully automated drainage and bacterial filtration of condensate in the anesthesia machine circuit. The system dynamically matches the respiratory phase and condensation rate to adjust the drainage strategy, ensuring that the drainage process does not interfere with normal circuit ventilation. Through multi-stage gas-liquid separation and graded filtration, liquid and microbial impurities are effectively removed, improving the safety of the refluxed gas phase. Combined with a concentration-adaptive reflux mechanism, efficient recycling of anesthetic drugs is achieved, comprehensively improving the operational safety, stability, and economy of the anesthesia circuit. Figure 1 As shown.

[0028] Example 2: This embodiment provides an automatic condensate drainage and bacterial filtration system for anesthesia machine circuits with adaptive control capabilities. Addressing the shortcomings of existing anesthesia circuit systems, such as low condensate collection efficiency, poor timing of drainage, easy interruption of the filtration process, and large fluctuations in anesthetic drug concentration, the system employs a series of technical mechanisms. These include spiral hydrophobic control of condensate collection, dynamic threshold and phase matching for drainage triggering, multi-layer interception to prevent entrainment during gas-liquid separation, dual-path redundancy backup for bacterial filtration, and closed-loop concentration regulation of gas-phase reflux. This achieves efficient directional condensate collection, precise timing of drainage, efficient gas-liquid separation, continuous sterilization and purification, and stable anesthetic drug reflux. The system can adapt to different patients' ventilation parameters and operating room environmental conditions, reducing the risk of condensate-related infections and minimizing anesthetic drug waste while stabilizing circuit respiratory parameters.

[0029] This system is connected in series between the expiratory and inspiratory branches of the anesthesia machine's breathing circuit. After the system starts, each module independently collects operating parameters and performs distributed control. At the same time, it achieves full-process coordination through signal interaction. The working principle and operation process of each module are as follows: The core function of the condensation and water collection module is to directionally collect dispersed droplets condensed on the circuit wall to a designated area, providing a basis for subsequent centralized drainage. When the hot, humid air carrying exhaled water vapor from the patient in the circuit comes into contact with the cooler circuit wall, the water vapor becomes saturated and condenses into liquid droplets, adhering to the inner wall of the circuit. If these droplets remain on the wall for a long time, they are prone to microbial growth and may enter the patient's airway with the airflow, posing a risk of coughing and infection. To solve this problem, the module incorporates a spiral flow control logic, with a continuous spiral flow guidance channel machined into the inner wall of the module. This channel extends downwards in a spiral along the airflow direction, forming a preset droplet flow path. The droplets formed by condensation on the wall, under the combined action of gravity and the tangential thrust of the exhaled airflow, continuously flow downwards along the spiral guidance channel, eventually converging into the collection area at the bottom of the module. The spiral path extends the guiding distance of the droplet flow, preventing droplets from falling directly and being entrained by the airflow, thus improving the stability of the collection. The module synchronously manages the hydrophobic surface condition. Its core principle is that the adhesion of droplets to a solid wall is determined by the equivalent wetting contact angle. A smaller contact angle results in a larger droplet spreading area, stronger adhesion, and greater difficulty in flow; a larger contact angle makes the droplet closer to a sphere, resulting in weaker adhesion and easier flow driven by external forces. The module adjusts the equivalent wetting contact angle by regulating the temperature distribution on the wall of the flow path, thereby altering the wetting characteristics of the wall-droplet interface. During operation, the module monitors the droplet's residence time on the wall in real time. When the residence time exceeds the preset range of 0s to 20s, it adjusts the wall temperature parameters to increase the droplet wetting contact angle, reduce droplet flow resistance, and promote directional flow, preventing droplets from lingering in non-collection areas. At the level monitoring level, the module implements variable sampling control based on the matching loop's ventilation rhythm. During the exhalation phase, a large amount of warm, humid gas flows through the module, resulting in a rapid condensation rate and a fast rise in the liquid level in the collection area. Therefore, the module increases the liquid level sampling frequency and reduces the sampling interval to accurately track the liquid level change trend. During the inhalation phase, the airflow direction reverses, the condensation rate decreases significantly, and liquid level fluctuations decrease. The module switches to the basic sampling frequency, ensuring monitoring effectiveness while reducing sensor power consumption and system data processing load. The module transmits the processed condensation volume data to the drainage trigger module in real time as input parameters for drainage control.

[0030] The drainage trigger module is responsible for precisely controlling the timing and duration of the drainage path's opening and closing. Its core objective is to promptly drain condensate while minimizing interference with the venting of the drainage circuit. Traditional drainage methods with fixed liquid level thresholds cannot adapt to differences in condensation rates under varying temperature differences and moisture levels, easily leading to problems such as excessively frequent drainage interfering with the circuit, or delayed drainage causing water accumulation and bacterial growth. Therefore, this module employs dynamic threshold calculation logic. The formula for calculating the dynamic drainage trigger liquid level threshold is: , in the formula, The liquid level threshold is triggered by dynamic drainage; The temperature difference between the gas in the loop and the environment is the thermodynamic driving force for the formation of condensate. The greater the temperature difference, the more water vapor condenses per unit time. This term has a positive coefficient. Positive correction to the threshold; The cumulative tidal volume per minute represents the total amount of water vapor transported by the loop per unit time. A higher tidal volume results in a higher rate of condensation formation. This term has a positive coefficient. Positive correction to the threshold; The base liquid level threshold is a calibrated baseline drainage level. Two operating condition correction terms are superimposed on the base threshold to obtain a dynamic trigger liquid level that matches the current operating condition, dynamically matching the drainage frequency with the condensate generation rate, balancing drainage timeliness and loop stability. The module incorporates ventilation phase matching logic, identifying the inspiratory and expiratory phases of the respiratory cycle by acquiring the loop's real-time flow signal. Since the loop experiences negative or positive low-pressure airflow during the inspiratory phase, opening the drainage path at this time would lead to external air entering or loop gas leakage, interfering with tidal volume and anesthetic concentration accuracy. However, during the end-expiratory phase, the loop pressure is stable and the airflow velocity is low, minimizing the impact of drainage on loop parameters. Therefore, the module strictly limits the drainage action execution window to the end-expiratory phase, locking the drainage path throughout the inspiratory phase. When the liquid level reaches the dynamic threshold and enters the end-expiratory window, the module outputs a drainage execution signal, opening the drainage path. Simultaneously, the module implements adaptive drainage duration control. Based on the current condensate volume and the flow capacity of the drainage path, it calculates the required drainage duration. The higher the volume, the longer the drainage duration, ensuring complete drainage while preventing excessive gas phase loss due to prolonged operation. After drainage is complete, the path automatically resets and closes, and a fluid pre-notification signal is sent to the gas-liquid separation module, prompting downstream modules to enter a ready-to-operate state in advance. Figure 2 As shown.

[0031] The gas-liquid separation module separates the liquid water from the anesthetic-containing gas phase in the discharged gas-liquid mixture. The liquid phase is stored in the waste liquid unit, while the gas phase enters the filtration stage. The core objective is to improve separation efficiency and prevent the liquid phase from entering the downstream filter layer with the gas phase. The module incorporates multi-layered staggered interception and control logic. Multiple inclined interception plates are installed within the separation chamber, with adjacent layers staggered to form a tortuous flow channel. After entering the separation chamber, the gas-liquid mixture flows along the channel. Due to its high inertia, the liquid water droplets cannot quickly change direction with the airflow and will collide with the surface of the interception plates. After losing kinetic energy, they adhere to the plate surface and slide down the inclined plate surface under gravity, eventually flowing into the waste liquid storage unit at the bottom. The gas phase, on the other hand, flows upwards through the gaps in the flow channel, gradually separating from the liquid phase region. The multi-layered staggered structure increases the probability of droplet collision and improves the interception effect of small droplets. To prevent droplets condensing on the inner wall of the separation chamber from being re-entrained by the rising airflow, the module incorporates a ring-shaped spiral guide path within the separation chamber's inner wall. Droplets condensing on the wall flow continuously downwards along this path, directly converging into the waste liquid storage unit, thus blocking the path for the droplets to be re-carried by the airflow and further improving gas-liquid separation efficiency. The waste liquid storage system employs a one-way self-sealing mechanism. The inlet passage has a built-in elastic closing structure that remains closed under normal conditions, isolating the waste liquid chamber from the separation chamber's gas exchange and preventing backflow of microorganisms or volatile components from the waste liquid into the gas phase. When liquid waste flows in from upstream, the static pressure of the liquid overcomes the elastic force, opening the passage structure and allowing the waste liquid to flow smoothly into the storage unit. After the flow is complete, the pressure disappears, and the passage automatically springs back to close, achieving self-sealing. The module monitors the capacity of the waste liquid storage unit in real time. When the rated capacity limit of 200mL is reached, a replacement prompt is triggered, and the upstream drainage passage is locked to prevent waste liquid overflow. After replacement, the system performs a sealing pressure test; after verifying a successful seal, it automatically unlocks and resumes normal operation.

[0032] The bacterial filtration module is responsible for purifying the separated gas phase, removing microorganisms and particulate impurities to ensure the biosafety of the returned gas phase. The module employs a hierarchical filtration control logic, with two filtration units: the first stage is a pre-filtration unit using hydrophobic porous filter material, primarily trapping residual micro-droplets and large-diameter dust particles in the gas phase. This prevents droplets from wetting the downstream sterilization membrane, thus reducing filtration efficiency, and also blocks large particles, extending the lifespan of the sterilization filter layer. The second stage is the sterilization filtration unit, using a high-precision sterilization membrane that traps pathogenic microorganisms such as bacteria and fungi, as well as fine-diameter impurities, achieving deep purification of the gas phase. To ensure the continuity of the filtration process, the module has two filtration paths, a primary and a backup, simultaneously monitoring and controlling the filter layer status. The module collects pressure data before and after the filter layer, calculating the filtration pressure difference. The magnitude of the pressure difference directly reflects the degree of filter layer clogging: a smaller pressure difference indicates better filter layer permeability; a larger pressure difference indicates that the filter layer traps more impurities, resulting in more severe clogging. When the differential pressure rises to the set threshold of 1.5 kPa, the module triggers a filter replacement prompt signal and automatically switches to the backup filtration path, which then continues to perform the filtration task. The switching action is completed at the end of exhalation to avoid impacting the airflow in the loop, ensuring that the gas phase purification process is uninterrupted and improving the continuity of system operation.

[0033] The function of the gas-phase reflux module is to return the purified anesthetic-containing gas phase to the inspiratory branch of the anesthesia machine, achieving the recycling of the anesthetic drug while maintaining the stability of the anesthetic concentration in the circuit. The module employs adaptive flow regulation logic, dynamically adjusting the reflux flow rate based on the deviation in the circuit's anesthetic gas concentration. The calculation formula is as follows: , in the formula, For real-time return traffic; The base return flow rate ensures the minimum circulating gas volume and maintains gas flow within the passage. The target concentration of anesthetic gas set for the circuit. The concentration of anesthetic gas is collected in real time by the circuit, and the difference between the two reflects the deviation between the current concentration and the target value; The concentration deviation adjustment coefficient, being positive, determines the flow rate adjustment range corresponding to a unit concentration deviation. When the real-time concentration is lower than the set value, the deviation is positive, increasing the reflux flow rate to replenish the loop with more gas containing anesthetic, pushing the concentration back up. When the real-time concentration is higher than the set value, the deviation is negative, decreasing the reflux flow rate to reduce the cyclic replenishment of anesthetic and prevent excessively high concentrations. This closed-loop adjustment mechanism helps stabilize the anesthetic concentration in the loop and reduces the amount of additional anesthetic supply. The module incorporates unidirectional flow restriction logic, with a unidirectional conduction structure in the reflux path, allowing only the gas phase to flow from the filter side to the inspiratory branch. If reverse airflow occurs, the path is immediately locked to prevent fresh gas or anesthetic gas from the inspiratory branch from flowing back into the filter module, causing drug leakage and loop parameter malfunctions. Simultaneously, the module implements flow rate upper limit control, with a preset maximum refluxing flow rate threshold of 10L / min. When the refluxing flow rate approaches the threshold due to excessive concentration deviation, the module automatically adjusts the flow cross-sectional area of ​​the pathway to limit the maximum refluxing flow rate, confining it within a safe range of 3L / min to 8L / min. This prevents excessive refluxing flow from interfering with core parameters of the breathing circuit, such as tidal volume and airway pressure, ensuring the safety and stability of the anesthesia machine ventilation. Figure 3 As shown.

[0034] The system described in this embodiment starts from the control mechanism of each link, improves the efficiency of condensate collection through spiral hydrophobic guidance, achieves precise drainage through dynamic threshold and phase matching, enhances gas-liquid separation through multi-layer interception and anti-entrainment design, ensures continuous purification through dual-path redundant filtration, and achieves stable reuse of anesthetic drugs through concentration closed-loop reflux. The entire system has strong adaptability to different operating conditions and can be adapted to different patient ventilation conditions and operating room environments. While effectively reducing the risk of condensate-related infections, it also reduces the consumption of anesthetic drugs and improves the stability and safety of the anesthesia circuit operation.

[0035] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. An automatic condensate drainage and bacterial filtration system for an anesthesia machine circuit, characterized in that, The system includes: Condensation and water collection module: acquires the operating data of the anesthesia machine's breathing circuit, collects the internal gas temperature and humidity parameters and condensate generation status, performs directional collection and control of condensate, completes real-time monitoring of condensate storage, and synchronously pushes the condensate storage data to the drainage trigger module. Drainage trigger module: Receives condensate storage data, combines it with loop ventilation phase information to execute drainage path on / off control, outputs drainage execution signal to gas-liquid separation module, and completes the phased discharge control of condensate. Gas-liquid separation module: Responds to drainage execution signal, receives the discharged gas-liquid mixture, performs gas-liquid two-phase separation control, introduces liquid waste liquid into waste liquid storage unit, and delivers the separated gas phase containing anesthetic drugs to bacterial filtration module; Bacterial filtration module: Receives gas phase containing anesthetic drugs, performs graded sterilization filtration control, intercepts microorganisms and particulate impurities in the gas phase, and delivers the purified gas phase to the gas phase reflux module; Gas phase reflux module: Receives the purified gas phase, performs reflux flow control, and delivers the purified gas phase containing anesthetic drugs back to the inhalation branch of the anesthesia machine to complete the anesthetic drug recycling control.

2. The automatic condensate drainage and bacterial filtration system for an anesthesia machine circuit according to claim 1, characterized in that, The condensate collection module incorporates a spiral flow control logic, guiding the flow direction of condensate along a continuous spiral path. This guides the droplets condensed on the inner wall of the loop to converge towards the bottom collection area along a preset path. Simultaneously, it sets the sampling frequency for monitoring the liquid level in the collection area and adjusts the sampling interval to match the loop's ventilation rhythm. During exhalation, the sampling density is increased, while during inhalation, the basic sampling frequency is maintained. Simultaneously, it implements hydrophobic surface condition control, adjusting the temperature distribution on the flow path wall based on the condensate retention time. This temperature change alters the equivalent wetting contact angle of the droplets on the wall, controlling the adhesion and flow resistance of the droplets and ensuring they maintain directional flow, preventing them from remaining in non-collection areas for extended periods.

3. The automatic condensate drainage and bacterial filtration system for an anesthesia machine circuit according to claim 1, characterized in that, The drainage triggering module uses dynamic threshold calculation logic to determine the drainage triggering conditions. The calculation formula is as follows: ,in, The liquid level threshold is triggered by dynamic drainage; The temperature of the gas inside the circuit; Operating room ambient temperature; The cumulative tidal volume per minute; The basic liquid level threshold; This is the temperature influence coefficient. The tidal volume influence coefficient. and All are positive numbers. Weights used to characterize the effect of temperature difference on condensate production The weighting of the influence of tidal volume on the condensate generation rate is used to characterize the drainage triggering liquid level threshold obtained in real time; the drainage triggering determination is based on the dynamic drainage triggering liquid level threshold obtained in real time.

4. The automatic condensate drainage and bacterial filtration system for an anesthesia machine circuit according to claim 1, characterized in that, The drainage triggering module incorporates ventilation phase matching logic to identify the inspiratory and expiratory phases of the breathing circuit in real time. It limits the drainage action execution window to the end of the expiratory phase, while maintaining the drainage passage closed throughout the inspiratory phase. Simultaneously, it performs drainage duration control, matching the corresponding drainage duration based on the current condensate level. The higher the condensate level, the longer the drainage duration. After the drainage action is completed, it automatically resets the passage status and simultaneously sends a fluid arrival pre-notification signal to the gas-liquid separation module to ensure that the downstream module enters the waiting state in advance.

5. The automatic condensate drainage and bacterial filtration system for an anesthesia machine circuit according to claim 1, characterized in that, The gas-liquid separation module incorporates multi-layered staggered interception and control logic, setting up multi-layered inclined interception paths. When the gas-liquid mixture flows along these paths, liquid droplets, after being blocked, will flow downwards along the surface of the interception path into the waste liquid storage unit, while the gaseous fluid will flow upwards along the gaps in the paths into the bacterial filtration module. Simultaneously, wall condensate diversion control is implemented, with an annular diversion path set up on the wall of the separation area to guide the condensed droplets on the wall along the diversion path into the waste liquid storage unit, preventing the droplets accumulated on the wall from being re-entrained into the gas phase area by the airflow.

6. The automatic condensate drainage and bacterial filtration system for an anesthesia machine circuit according to claim 1, characterized in that, The gas-liquid separation module is equipped with waste liquid storage control logic, which controls the on / off state of the inlet passage of the waste liquid storage unit. Under normal circumstances, the inlet passage remains closed. Only when liquid waste liquid is input from upstream will the inlet passage be opened under the fluid pressure of the liquid waste liquid. After the waste liquid flows in, the inlet passage will automatically return to the closed state. Simultaneously, waste liquid storage monitoring and control is performed, and the waste liquid capacity data in the waste liquid storage unit is collected in real time. When the rated capacity limit is reached, a replacement prompt is triggered, and the upstream drainage passage is locked at the same time. After the replacement is completed and the sealing verification is passed, the upstream passage lock status is automatically released.

7. The automatic condensate drainage and bacterial filtration system for an anesthesia machine circuit according to claim 1, characterized in that, The bacterial filtration module has a built-in hierarchical filtration control logic, which sets up a two-stage filtration process: the first stage performs pre-filtration control to intercept tiny droplets and large particles entrained in the gas phase, and the second stage performs sterilization filtration control to intercept microorganisms and fine particle impurities in the gas phase. The filter layer status monitoring and control is performed synchronously, and the pressure difference data before and after filtration is collected. The filter layer blockage status is judged based on the pressure difference change. When the pressure difference reaches the set threshold, the filter layer replacement prompt is triggered, and the system switches to the backup filtration path to maintain the uninterrupted gas phase purification process.

8. The automatic condensate drainage and bacterial filtration system for an anesthesia machine circuit according to claim 1, characterized in that, The gas phase reflux module uses adaptive flow regulation logic to control the reflux flow rate, and the calculation formula is as follows: ,in, For real-time return traffic; Basic return flow; Set the concentration of anesthetic gas for the circuit; Real-time concentration of anesthetic gas in the circuit; This is the concentration deviation adjustment coefficient, and >0 is used to characterize the adjustment range of anesthetic gas concentration deviation on reflux flow rate, with a value range of 0.5 to 2.0 L·min⁻¹ / %; the flow capacity of the passage is adjusted based on the real-time reflux flow rate calculated in real time.

9. The automatic condensate drainage and bacterial filtration system for an anesthesia machine circuit according to claim 1, characterized in that, The gas phase reflux module has a built-in one-way flow restriction control logic, which sets a one-way flow path for the gas phase fluid, allowing only the purified gas phase to flow from the filter side to the inhalation branch of the anesthesia machine. Reverse airflow triggers a path locking mechanism. Synchronously implement flow limit control, set the maximum threshold for recirculation flow, and when the actual recirculation flow exceeds the maximum threshold, automatically reduce the flow area of ​​the passage to limit the recirculation flow within a safe range, so as to avoid excessive recirculation flow from interfering with the normal gas parameters of the breathing circuit.

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