Side stream structure containing mirror sheath flow monitoring system, method, device and storage medium

Abstract

The application relates to the technical field of medical devices, and provides a mirror sheath flow monitoring system, a mirror sheath flow monitoring method, a mirror sheath flow monitoring device and a storage medium, the system comprising: a mirror sheath body, and a variable-diameter measurement cavity formed by a throttling structure in the inner cavity, the variable-diameter measurement cavity having an inlet section and a throat portion, and the variable-diameter ratio of the variable-diameter measurement cavity being determined based on the maximum flow range of target monitoring and the full range of a pressure difference sensor; a first sampling port arranged on the side wall of the inlet section and located in a high-pressure area upstream of the variable-diameter measurement cavity; a second sampling port arranged on the side wall of the throat portion and located in a low-pressure area downstream of the variable-diameter measurement cavity; a pressure difference sensor connected with the first sampling port and the second sampling port respectively, and acquiring a pressure difference signal of the first sampling port and the second sampling port; and a controller connected with the pressure difference sensor, and calculating the gas flow through the variable-diameter measurement cavity according to the pressure difference signal and the variable-diameter ratio. The application realizes high-precision flow monitoring by combining the variable-diameter measurement cavity and the pressure difference signals collected at the first sampling port and the second sampling port.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and in particular to a sheath flow monitoring system, method, device and storage medium with a bypass structure. Background Technology

[0002] High-frequency jet ventilators can be connected to accessories such as laryngoscope sheaths, tracheoscope sheaths, and bronchoscope sheaths via jet tubing for respiratory support via the larynx, trachea, or bronchi. In existing technologies, laryngoscope sheaths, tracheoscope sheaths, and bronchoscope sheaths only have pressure and gas sampling channels, lacking flow monitoring capabilities.

[0003] Based on the ARDSNet clinical study, a small tidal volume of 6 ml / kg has become the gold standard for mechanical ventilation, and high-frequency jet ventilators also fall under this category. However, current high-frequency jet ventilators lack flow monitoring and mostly operate based on driving pressure rather than flow. Even after setting the jet pressure, the actual tidal volume entering the patient's lungs remains unknown. Only pressure and gas sampling can monitor airway pressure, oxygen, and carbon dioxide levels, achieving a minimum level of safety assurance, rather than lung-protective ventilation. This approach makes precise control of tidal volume in clinical practice difficult, hindering the implementation of lung-protective ventilation strategies.

[0004] It is evident that existing high-frequency jet ventilators suffer from low flow monitoring accuracy. Summary of the Invention

[0005] This application provides a sheath flow monitoring system, method, device, and storage medium with a bypass structure to solve the technical problem of low flow monitoring accuracy in the sheaths of existing high-frequency jet ventilators.

[0006] According to a first aspect of the present invention, a mirror sheath flow monitoring system with a bypass structure is provided. The system includes: a mirror sheath body, wherein the inner cavity of the mirror sheath body is provided with a variable diameter measuring cavity formed by a throttling structure, the variable diameter measuring cavity having an inlet section and a throat, and the variable diameter ratio of the variable diameter measuring cavity is determined collaboratively based on the maximum flow range of the target monitoring and the full scale of a differential pressure sensor; a first sampling port disposed on the side wall of the inlet section, located in a high-pressure region upstream of the variable diameter measuring cavity; a second sampling port disposed on the side wall of the throat, located in a low-pressure region downstream of the variable diameter measuring cavity; a differential pressure sensor connected to the first sampling port and the second sampling port respectively, for acquiring differential pressure signals from the first sampling port and the second sampling port; and a controller connected to the differential pressure sensor, for calculating the gas flow rate through the variable diameter measuring cavity based on the differential pressure signals and the variable diameter ratio.

[0007] Optionally, the system further includes a gauge pressure sensor connected to the first sampling port via a sampling pipeline for acquiring real-time gauge pressure signals of the airway.

[0008] Optionally, the controller is also used to perform airway pressure safety monitoring based on the real-time airway gauge pressure signal.

[0009] Optionally, the first sampling port also serves as a gas pressure sampling end, and the second sampling port is connected to a gas sampling pipeline via a controllable valve; the controller is also used to: control the controllable valve to close during the flow monitoring period and calculate the instantaneous flow rate based on the differential pressure signal; or control the controllable valve to open during the gas monitoring period, acquire the gas composition signal based on the gas sampling pipeline, and switch the flow algorithm to zero-order hold mode or predictive compensation mode.

[0010] Optionally, the gas sampling pipeline includes a gas analyzer and a connecting pipeline. The controllable valve is installed on the connecting pipeline between the second sampling port and the gas analyzer and is connected to the controller via a control line to control the on / off state of the gas sampling pipeline.

[0011] According to a second aspect of the present invention, a method for monitoring the flow rate of a mirror sheath with a bypass structure is also provided. The method includes: acquiring differential pressure signals generated at both ends of the variable diameter measuring cavity using a differential pressure sensor based on a first sampling port located in a high-pressure zone upstream of the variable diameter measuring cavity and a second sampling port located in a low-pressure zone downstream of the variable diameter measuring cavity; determining a variable diameter ratio based on the maximum flow rate range of the target monitoring and the full scale range of the differential pressure sensor; and calculating the gas flow rate through the variable diameter measuring cavity according to the differential pressure signal and the variable diameter ratio.

[0012] Optionally, the step of determining the diameter ratio based on the maximum flow range of the target monitoring and the full scale of the differential pressure sensor includes: establishing a correlation model of differential pressure, flow rate, and diameter ratio according to Bernoulli's equation and the continuity equation; obtaining the maximum flow range of the target monitoring and the full scale of the differential pressure sensor; calculating the theoretical differential pressure corresponding to different diameter ratio values ​​based on the maximum flow range of the target monitoring and the full scale of the differential pressure sensor through the correlation model; comparing the theoretical differential pressure with the linear range of the differential pressure sensor, and selecting a preset diameter ratio value that makes the theoretical differential pressure fall within a preset proportional range of the linear range as the diameter ratio.

[0013] Optionally, after acquiring the differential pressure signal generated at both ends of the variable diameter measuring cavity through a differential pressure sensor based on the first sampling port located in the high-pressure zone upstream of the variable diameter measuring cavity and the second sampling port located in the low-pressure zone downstream of the variable diameter measuring cavity, the method further includes: acquiring the real-time gauge pressure signal of the airway through a gauge pressure sensor; and performing airway pressure safety monitoring based on the real-time gauge pressure signal of the airway.

[0014] According to a third aspect of the present invention, a computer device is also provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the mirror sheath flow monitoring method with a bypass structure of the second aspect.

[0015] According to a fourth aspect of the invention, a storage medium is also provided, on which a computer program is stored, which, when executed by a processor, implements the steps of the sheath flow monitoring method with a bypass structure of the second aspect.

[0016] Compared with related technologies, the technical solutions provided in this application have the following advantages: This application provides a sheath flow monitoring system with a bypass structure. By providing a throttling structure in the inner cavity of the sheath body to form a variable diameter measurement cavity with a certain variable diameter ratio, and providing a first sampling port and a second sampling port upstream and downstream of the variable diameter measurement cavity respectively, the gas dynamic characteristics inside the sheath can be converted into a measurable differential pressure signal using a differential pressure sensor. Combined with the variable diameter ratio, the gas flow rate through the variable diameter measurement cavity can be calculated, thereby realizing real-time and accurate monitoring of the gas flow rate in the variable diameter measurement cavity. This is beneficial for high-frequency jet ventilators to be controlled based on actual flow rate rather than driving pressure, thereby accurately controlling the tidal volume entering the patient's lungs. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0018] Figure 1 A schematic diagram of an optional mirror sheath flow monitoring system with a bypass structure provided for an embodiment of the present invention; Figure 2 A schematic diagram of an optional variable diameter measuring cavity structure and sampling port layout provided for an embodiment of the present invention; Figure 3 An optional multi-parameter time-division multiplexing sampling timing diagram is provided for embodiments of the present invention; Figure 4 A flowchart of an optional variable diameter ratio collaborative design method provided in an embodiment of the present invention; Figure 5 A schematic diagram of another optional mirror sheath flow monitoring system with a bypass structure provided for an embodiment of the present invention; Figure 6This is a schematic diagram of an optional electronic device structure provided in an embodiment of this application. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] To address the problems mentioned in the background art, according to one aspect of the embodiments of this application, an embodiment of a mirror sheath flow monitoring system with a bypass structure is provided.

[0021] like Figure 1 As shown, it is a schematic diagram of a mirror sheath flow monitoring system with a bypass structure. The mirror sheath flow monitoring system with a bypass structure includes a mirror sheath body 101, a first sampling port 102, a second sampling port 103, a differential pressure sensor 104, a gauge pressure sensor 105, a controllable valve 106, and a controller 107.

[0022] The sheath body 101 has an inner cavity with a variable diameter measuring cavity 201 formed by a throttling structure. The variable diameter measuring cavity 201 has an inlet section 202 and a throat 203. The inner diameter of the inlet section is D, and the inner diameter of the throat is d. The throttling structure refers to a cross-sectional contraction structure set within the inner cavity of the sheath body 101. This cross-sectional contraction structure has an inlet section 202 and a throat 203. The inner diameter of the inlet section 202 is larger than the inner diameter of the throat 203, forming a smooth transition contraction from the inlet section to the throat. The profile of this smooth transition contraction meets streamline requirements to avoid flow separation. The throttling structure converts the kinetic energy of the gas flow inside the sheath into a measurable pressure difference signal. The pressure difference signal has a definite functional relationship with the gas flow rate. Based on the measured pressure difference signal and the variable diameter ratio, flow rate measurement can be achieved.

[0023] In this embodiment, the sheath body 101 is a laryngoscope sheath. As an optional implementation, the sheath body 101 can also be a tracheoscope sheath or a bronchoscope sheath, used for interventional procedures via the larynx, trachea, or bronchi.

[0024] It should be noted that the mirror sheath flow monitoring method with a bypass structure provided in the embodiments of the present invention is generally executed by the controller 107.

[0025] In this embodiment, the diameter ratio β of the variable diameter measuring cavity 201 is not a fixed value, but is determined collaboratively based on the maximum flow range Qmax of the target monitoring and the full scale ΔPmax of the differential pressure sensor 104. Specifically, according to Bernoulli's equation and the continuity equation, a correlation model is established between the differential pressure ΔP, the flow rate Q, and the diameter ratio β. The value of β is iteratively adjusted so that when Q=Qmax, ΔP is located within 60% to 90% of the linear range of the differential pressure sensor.

[0026] As an optional implementation, the maximum flow rate range Qmax is 100 liters per minute, and the full-scale range ΔPmax of the differential pressure sensor 104 is 500 Pa. In this case, the β value ensures that when Q is 100 liters per minute, ΔP is within the range of 300 Pa to 450 Pa. This structural design, adapted to the sensor, improves the signal-to-noise ratio at low flow rates while preventing overflow at high flow rates, resulting in an overall system accuracy better than 10%. The diameter ratio refers to the ratio of the throat's inner diameter to the inlet section's inner diameter, i.e., β = d / D. The diameter ratio characterizes the degree of contraction of the diameter measurement cavity; a smaller diameter ratio indicates more severe throat contraction, while a larger diameter ratio indicates smoother throat contraction.

[0027] In this embodiment, a variable diameter measurement cavity with a certain diameter ratio is formed by providing a throttling structure in the inner cavity of the sheath body. At the same time, a first sampling port and a second sampling port are respectively provided upstream and downstream of the variable diameter measurement cavity. Then, the gas dynamic characteristics inside the sheath can be converted into a measurable differential pressure signal by using a differential pressure sensor. Combined with the diameter ratio, the gas flow rate flowing through the variable diameter measurement cavity can be calculated, thereby realizing real-time and accurate monitoring of the gas flow rate in the variable diameter measurement cavity. This is beneficial for the high-frequency jet ventilator to be controlled based on the actual flow rate rather than the driving pressure, thereby accurately controlling the tidal volume entering the patient's lungs.

[0028] like Figure 2 As shown, Figure 2 This is a schematic diagram of an optional variable diameter measuring cavity structure and sampling port layout provided for an embodiment of the present invention.

[0029] In this embodiment, the first sampling port 102 is located on the side wall of the inlet section 202, in the high-pressure area upstream of the variable diameter measurement cavity 201, and serves as both the high-pressure end for flow differential pressure sampling and the airway gauge pressure sampling end.

[0030] In this embodiment, the second sampling port 103 is located on the side wall of the throat 203, in the low-pressure area downstream of the variable diameter measuring cavity 201, and serves as both the low-pressure end for flow rate differential sampling and the gas composition extraction channel.

[0031] In this embodiment, the differential pressure sensor 104 is connected to the first sampling port 102 and the second sampling port 103 via sampling pipelines to acquire the differential pressure signal ΔP across the variable diameter measuring cavity 201. The differential pressure sensor 104 is preferably a micro differential pressure sensor with a linear high sensitivity range.

[0032] In this embodiment, the gauge pressure sensor 105 is connected to the first sampling port 102 through a sampling pipeline to obtain the real-time gauge pressure signal Pg of the airway.

[0033] In this embodiment, the gas sampling pipeline includes a gas analyzer and a connecting pipeline. A controllable valve 106 is installed on the connecting pipeline between the second sampling port 103 and the gas analyzer, and is connected to the controller 107 via a control line to control the on / off state of the gas sampling pipeline. The controllable valve 106 can be a solenoid valve, a pneumatic valve, or other controllable on / off device.

[0034] In this embodiment, the controller 107 is connected to the differential pressure sensor 104, the gauge pressure sensor 105, and the controllable valve 106 via signal lines, and is used to adjust the differential pressure signal based on the differential pressure signal. The gas flow rate Q is calculated based on the diameter ratio β, and the airway pressure is monitored for safety based on the real-time gauge pressure signal Pg.

[0035] In this embodiment, based on the differential pressure signal And the calculation of gas flow rate Q based on the diameter ratio β, specifically including: Calculate the throat inner diameter d = β × D based on the diameter ratio β and the inlet section inner diameter D; Calculate the cross-sectional area of ​​the throat based on its inner diameter d. =π×(d / 2)²=π×(β×D / 2)²; Based on the differential pressure signal Gas density under standard conditions Given the throat cross-sectional area A and the flow coefficient Cd, calculate the gas flow rate Q = .

[0036] Among them, the gas density under standard conditions The concentration of oxygen for medical use is 1.225 kg / m³, and for pure oxygen environment it is 1.429 kg / m³; the flow coefficient Cd is determined by experimental calibration.

[0037] In this embodiment, airway pressure safety monitoring is performed based on the real-time airway gauge pressure signal Pg, specifically including: Compare the real-time airway pressure signal Pg with the preset upper safety threshold Pmax and lower safety threshold Pmin; If Pg > Pmax, a high-pressure alarm will be triggered in the output airway, indicating increased airway resistance or blockage in the tubing. If Pg < Pmin, a low-pressure alarm will be triggered in the output airway, indicating that the pipeline may be disconnected or leaking. If Pmin≤Pg≤Pmax, the airway pressure is considered normal, and monitoring should continue.

[0038] In this embodiment, the upper limit of the safety threshold Pmax is set to 4 kPa, and the lower limit of the safety threshold Pmin is set to -0.5 kPa, which is suitable for high-frequency jet ventilation scenarios for adults. For pediatric scenarios, the thresholds are adjusted accordingly.

[0039] like Figure 3 As shown, Figure 3 This is a multi-parameter time-division multiplexing sampling timing diagram provided for an embodiment of the present invention.

[0040] To resolve the physical conflict between continuous airway pressure monitoring and gas sampling, the system introduces time-division multiplexing logic, specifically including: S301, Continuous pressure sampling: The airway pressure is monitored in real time through the first sampling port to ensure the continuity of airway safety warnings during the operation, without being affected by the start and stop of controllable valves; S302, Time-division multiplexing logic: Flow rate differential pressure calculation and gas composition analysis share the second sampling port; S303, Instantaneous Flow Calculation: During the flow monitoring period, the system controls the controllable valve to close, and the differential pressure sensor captures the high-frequency differential pressure signal to calculate the instantaneous flow.

[0041] S304, Gas Sample Composition Analysis: During the gas monitoring period, the system controls the controllable valve to open, extract gas samples for composition analysis, and at this time the flow algorithm enters zero-order hold mode or prediction compensation mode.

[0042] By using the above methods, while ensuring real-time monitoring, the complexity of the sheath's piping is greatly simplified, and dual-port multidimensional reuse is achieved.

[0043] In this embodiment, the controller 107 controls the controllable valve 106 to close during the flow monitoring period, based on the differential pressure signal. Calculate the gas flow rate Q; during the gas monitoring period, controllable valve 106 is opened to obtain the gas composition signal based on the gas sampling pipeline, and the flow algorithm is switched to zero-order hold mode or predictive compensation mode.

[0044] In this embodiment, the switching between the flow monitoring period and the gas monitoring period is controlled by the controller 107 according to a preset time period.

[0045] As an optional implementation, the preset time period is 200 milliseconds for the flow monitoring period and 50 milliseconds for the gas monitoring period, with a total cycle duration of 250 milliseconds, which is executed cyclically.

[0046] In this embodiment, during the flow monitoring period, the controllable valve 106 is closed, and the second sampling port 103 is only used as the low-pressure end for differential pressure sampling. There is no gas extraction interference, and the differential pressure sensor 104 can stably capture high-frequency differential pressure signals.

[0047] As an optional implementation, during the flow monitoring period, the controller 107 acquires the differential pressure signal at a sampling frequency of 1 kHz. High-frequency noise is eliminated by moving average filtering, with a sliding window size of ten sampling points.

[0048] In this embodiment, during the gas monitoring period, the controllable valve 106 is opened to extract gas samples for component analysis. At this time, the flow algorithm enters the zero-order hold mode or the prediction compensation mode.

[0049] In this embodiment, the zero-order hold mode means that during the gas monitoring period, the controller 107 locks the gas flow rate Q to the last valid value before the start of the gas monitoring period and holds it until the flow monitoring period resumes.

[0050] In this embodiment, the prediction compensation mode refers to predicting the current gas flow rate Q using weighted linear extrapolation based on historical gas flow rate data from the three most recent flow monitoring periods. pred The prediction formula is: Q pred =0.5×Q n-1 +0.3×Q n-2 +0.2×Q n-3 Q n-1 Q represents the gas flow rate Q in the most recent period. n-2 Q represents the gas flow rate Q in the next closest period. n-3 Q represents the gas flow rate Q during the furthest time period. pred This represents the current gas flow rate.

[0051] like Figure 4 As shown, Figure 4 This is a flowchart of the variable diameter ratio collaborative design method provided in an embodiment of the present invention. The variable diameter ratio collaborative design method includes: S501. Determine the maximum flow range Qmax of the target monitoring and the full scale ΔPmax of the differential pressure sensor as boundary constraints for the variable diameter ratio design.

[0052] In this embodiment, the aforementioned boundary constraints refer to the performance index range that the variable diameter ratio design must meet. The maximum flow rate range Qmax is determined by clinical needs, and the full-scale range ΔPmax of the differential pressure sensor is determined by sensor selection. As an optional implementation, for adult high-frequency jet ventilation scenarios, Qmax is taken as 100 liters per minute; for pediatric high-frequency jet ventilation scenarios, Qmax is taken as 50 liters per minute.

[0053] In this embodiment, the determination of boundary constraints also needs to consider safety margins. The maximum flow range Qmax should cover 120% of clinical needs to cope with abnormal operating conditions; the full-scale range ΔPmax of the differential pressure sensor should reserve 20% overload capacity to prevent transient impacts from damaging the sensor.

[0054] S502. Based on Bernoulli's equation and the continuity equation, establish a correlation model between the pressure difference signal ΔP and the gas flow rate Q and the diameter ratio β.

[0055] The aforementioned correlation model can refer to a set of equations describing the mathematical relationship between the pressure difference signal ΔP, the gas flow rate Q, and the diameter ratio β. Specifically, according to Bernoulli's equation, the pressure difference signal across the diameter measurement chamber... The relationship with the flow velocity v is ΔP = 0.5 × ρ × v² × (1 - β) 4 According to the continuity equation, the relationship between gas flow rate Q and flow velocity v is: Q=v×A=v×π×(d / 2)²=v×π×(β×D / 2)².

[0056] By combining the above equations, the pressure difference signal is obtained. The correlation model with gas flow rate Q and diameter ratio β is as follows: ΔP = 0.5×ρ×[Q / (π×(β×D / 2)²)]²×(1-β 4 ) In this embodiment, the above-mentioned correlation model clearly defines a monotonic correspondence that increases in the diameter ratio result in a narrower throat, increased flow velocity, and increased pressure difference, while decreases in the diameter ratio result in a wider throat, decreased flow velocity, and decreased pressure difference.

[0057] In this embodiment, the input parameters of the correlation model also include the inner diameter D of the inlet section and the gas density ρ. D is determined by the specifications of the laryngoscope sheath body. The typical value for an adult laryngoscope sheath is eight to ten millimeters, and the typical value for a pediatric laryngoscope sheath is five to seven millimeters. ρ adopts the air density under standard conditions. If applied to a pure oxygen environment, it needs to be replaced with the oxygen density of 1.430 kg per cubic meter.

[0058] The aforementioned correlation model, derived from the simultaneous equations of Bernoulli and continuity, elucidates the physical mapping relationship between the pressure difference signal ΔP, gas flow rate Q, and diameter ratio β from a fluid mechanics perspective, providing a theoretical basis for monitoring the gas flow rate in the sheath. However, in practical engineering applications, the boundary layer effect of the flow channel inside the sheath, local resistance losses, gas compressibility, and gas density changes caused by fluctuations in operating temperature and pressure all introduce systematic biases into the theoretical calculations.

[0059] Therefore, in this embodiment, the experimentally calibrated flow coefficient Cd is used to perform engineering modifications on the above theoretical model. Specifically, the diameter ratio correction term in the theoretical model is modified. (1 β 4 The deviation between the standard state gas density ρ0 and the actual operating density, as well as the flow channel loss factor, are uniformly incorporated into the flow coefficient Cd, thus obtaining a gas flow expression suitable for real-time calculation by the controller: Q=

[0060] Wherein, the throat cross-sectional area A = π × (β × D / 2)². For a sheath with a defined structure (the diameter ratio β and the inlet section inner diameter D are known design parameters) and a defined type of medical gas, the gas density ρ0 under standard conditions is a readily available constant, and the flow coefficient Cd can be calibrated through a finite number of pressure-flow comparison experiments. Provided that the calibration conditions and actual operating conditions are consistent, the above engineering expression can be directly used for real-time flow calculation.

[0061] S503. Initialize the diameter ratio based on the lower limit of the linear range of the differential pressure sensor, so that the initial theoretical differential pressure is lower than the target range.

[0062] In this embodiment, the initial diameter ratio β0 is set to 0.3. At this point, the theoretical pressure difference is much lower than the lower limit of the target range, ensuring that the iteration starts from a safe region. As an optional implementation, the initial diameter ratio β0 can be set from 0.2 to 0.4, with the specific value determined based on the inlet section inner diameter D and process constraints.

[0063] S504. Based on the current diameter ratio, calculate the theoretical pressure difference when the flow rate reaches the maximum flow range.

[0064] In this embodiment, Q=Qmax and the current β are substituted into the correlation model to calculate the theoretical pressure difference ΔPpred. As an optional implementation, the gas density ρ0 under standard conditions is used as the input parameter during the calculation to ensure the universality of the design results.

[0065] S505. Determine whether the theoretical differential pressure is within 60% to 90% of the linear range of the differential pressure sensor.

[0066] In this embodiment, the above judgment condition is: 0.6×ΔPmax≤ΔPpred≤0.9×ΔPmax. Sixty percent is selected as the lower limit to ensure sufficient signal strength at low flow rates, with a signal-to-noise ratio better than forty decibels; ninety percent is selected as the upper limit to retain a 10 percent margin to prevent pressure differential saturation when the flow rate exceeds the range, while avoiding increased nonlinear error caused by approaching full range.

[0067] S506. If so, then determine the current diameter ratio as the final diameter ratio, and the design is complete.

[0068] In this embodiment, the final diameter ratio βfinal satisfies the design constraints, thereby determining the throat inner diameter d = βfinal × D, and completing the structural design of the diameter measurement cavity 201. As an optional implementation, the final diameter ratio βfinal can range from 0.5 to 0.8.

[0069] S507. If the theoretical pressure difference is less than 60%, increase the diameter ratio according to the preset step size and return to S504 to recalculate.

[0070] In this embodiment, the adjustment step size of the diameter ratio is determined linearly based on the difference between the current theoretical pressure difference and the lower limit of the target range. The larger the difference, the larger the step size; the smaller the difference, the smaller the step size. The minimum step size is not less than one-thousandth, and the maximum step size is not more than five percent.

[0071] Specifically, the step size is calculated as follows: Δβ = k × (0.6 × ΔPmax - ΔPpred) / ΔPmax, where k is a proportionality coefficient with a value of 0.1. If the calculated step size is less than one-thousandth, then one-thousandth is used; if the calculated step size is greater than five percent, then five percent is used.

[0072] The new value after increasing the diameter ratio is: βnew = βold + Δβ.

[0073] S508. If the theoretical pressure difference is higher than 90%, then reduce the diameter ratio according to the preset step size and return to S504 to recalculate.

[0074] In this embodiment, the adjustment step size of the diameter ratio is determined linearly based on the difference between the current theoretical pressure difference and the upper limit of the target range. The larger the difference, the larger the step size; the smaller the difference, the smaller the step size. The minimum step size is not less than one-thousandth, and the maximum step size is not more than five percent.

[0075] Specifically, the step size is calculated as follows: Δβ = k × (ΔPpred - 0.9 × ΔPmax) / ΔPmax, where k is a proportionality coefficient with a value of 0.1. If the calculated step size is less than one-thousandth, then one-thousandth is used; if the calculated step size is greater than five percent, then five percent is used.

[0076] The new value after reducing the diameter ratio is: βnew = βold - Δβ.

[0077] In this embodiment, by establishing a correlation model between pressure difference, flow rate, and diameter ratio, and iteratively adjusting the diameter ratio based on boundary constraints, the theoretical pressure difference is placed within the optimal range of the sensor's linear interval. This enables the design of a structure that adapts to the sensor, ensuring that large flow rates do not overflow while improving the signal-to-noise ratio at low flow rates, resulting in a system overall accuracy better than 10%.

[0078] In some optional embodiments, the above iterative adjustment is set to a maximum of one hundred iterations, or the adjustment accuracy threshold is set to one-hundredth of the full scale; the iteration terminates when either condition is met. If convergence is not achieved after reaching the maximum number of iterations, a design anomaly alarm is output, indicating that the differential pressure sensor range needs to be reselected or the maximum flow range needs to be adjusted.

[0079] In this embodiment, the typical number of iterations for convergence is five to fifteen, depending on the distance between the initial value and the target range. The converged diameter ratio needs to be rounded to an accuracy of 0.01% to adapt to standard tool specifications and reduce processing costs. The rounded theoretical pressure difference deviation should be controlled within ±5% of the target range; otherwise, iteration must be repeated.

[0080] In this embodiment, the sheath flow monitoring system with a bypass structure, through precise design of the variable diameter ratio β, ensures that the sensor operates within its most sensitive range. This guarantees that high flow rates do not overflow while improving the signal-to-noise ratio at low flow rates, ensuring an overall system accuracy better than 10%. Utilizing the sheath's only two sampling holes, time-division multiplexing logic enables simultaneous monitoring of flow rate and real-time airway pressure, resolving the contradictions of multiple tubing lines, limited space, and numerous parameters. By directly measuring the gas flow through the sheath, the high-frequency jet ventilator can be controlled based on actual flow rate rather than driving pressure, precisely controlling the tidal volume entering the patient's lungs. This is more conducive to achieving a lung-protective ventilation strategy with a small tidal volume of six milliliters per kilogram. Furthermore, the system is compatible with various sheath types, including laryngoscope sheaths, tracheoscope sheaths, and bronchoscope sheaths, facilitating deployment in different interventional scenarios. It can be widely applied in sheath flow monitoring scenarios superimposed with high-frequency jet ventilators, such as lung-protective ventilation support for patients with acute respiratory distress syndrome, controlling tidal volume through precise flow monitoring; or, for example, respiratory support scenarios in high-altitude areas, ensuring measurement accuracy through altitude adaptive compensation.

[0081] As one possible implementation, an absolute pressure sensor can be introduced to monitor the ambient atmospheric pressure. Combined with the real-time measured airway gauge pressure, a gas density ρ correction model can be established for high-flow-rate jets to eliminate the interference of different altitudes on the flow measurement accuracy, thereby meeting the measurement accuracy requirements of operating rooms at different altitudes.

[0082] like Figure 5 As shown, Figure 5 This is a schematic diagram of another optional mirror sheath flow monitoring system with a bypass structure provided in this embodiment. The mirror sheath flow monitoring system with the bypass structure further includes an oxygen sensor, a carbon dioxide sensor, and an ambient pressure sensor. A first sampling port is connected to a differential pressure sensor and a gauge pressure sensor. A second sampling port is connected to a controllable valve, which is connected to both the oxygen sensor and the carbon dioxide sensor. A controller is connected to the differential pressure sensor, gauge pressure sensor, oxygen sensor, carbon dioxide sensor, and ambient pressure sensor, and is also connected to the controllable valve for time-sharing switching of the controllable valve.

[0083] Among them, the oxygen sensor is used to monitor the oxygen concentration, the carbon dioxide sensor is used to monitor the carbon dioxide concentration in the user's exhaled gas, and the environmental pressure sensor is used to monitor the atmospheric pressure of the environment. The first and second sampling ports of the mirror sheath flow monitoring system with bypass structure collect gas flow, oxygen concentration, carbon dioxide concentration and environmental pressure respectively under the time-sharing switching of the controllable valve by the controller. Without adding an additional physical sampling port, the physical conflict between continuous airway pressure monitoring and gas extraction sampling is resolved, and the effect of multi-dimensional reuse of the two sampling ports is achieved.

[0084] According to another aspect of the embodiments of this application, a computer program product or computer program is also provided, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the steps of the sheath flow monitoring method with a bypass structure in any of the above embodiments.

[0085] According to another aspect of the embodiments of this application, this application also provides an electronic device, such as... Figure 6 As shown, the device includes a memory 601, a processor 603, and a network interface 605. The memory 601 stores a computer program that can run on the processor 603. The memory 601 and the processor 603 communicate through the network interface 605 and a communication bus 607. When the electronic device is running, the processor 603 and the memory 601 communicate through the network interface 605. When the processor 603 executes the computer program, it implements the steps of the above-described sheath flow monitoring method with a bypass structure.

[0086] The memory and processor in the aforementioned electronic device communicate with each other via a communication bus and a communication interface. The communication bus can be a peripheral component interconnect standard (PCI) bus or an extended industry standard structure (EISA) bus, etc. This communication bus can be divided into an address bus, a data bus, a control bus, etc. The memory can include random access memory (RAM) or non-volatile memory, such as at least one disk storage device. Optionally, the memory can also be at least one storage device located remotely from the aforementioned processor. The aforementioned processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0087] It is understood that the embodiments described herein can be implemented using hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more application-specific integrated circuits, digital signal processors, digital signal processing devices, microprocessors, and other electronic units or combinations thereof for performing the functions described herein. For software implementation, the techniques described herein can be implemented by units that perform the functions described herein. Software code can be stored in memory and executed by a processor.

[0088] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. It should be understood from the embodiments provided in this application that the disclosed systems and methods can be implemented in other ways.

[0089] If the functions of the aforementioned system or method are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of this application, essentially or in other words, the parts that contribute to the prior art, or parts of the technical solutions, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0090] It should be noted that, in this document, relational terms such as first, second, etc., are used only to distinguish one entity or operation from another entity or operation. The terms include, encompass, or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0091] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A mirror sheath flow monitoring system with a bypass structure, characterized in that, include: The mirror sheath body has a variable diameter measuring cavity formed by a throttling structure in its inner cavity. The variable diameter measuring cavity has an inlet section and a throat. The variable diameter ratio of the variable diameter measuring cavity is determined collaboratively based on the maximum flow range of the target monitoring and the full scale of the differential pressure sensor. The first sampling port is located on the side wall of the inlet section, in the high-pressure area upstream of the variable diameter measuring cavity; The second sampling port is located on the side wall of the throat, in the low-pressure area downstream of the variable diameter measuring cavity; A differential pressure sensor is connected to the first sampling port and the second sampling port respectively, and is used to acquire the differential pressure signal between the first sampling port and the second sampling port; A controller, connected to the differential pressure sensor, is used to calculate the gas flow rate through the variable diameter measuring chamber based on the differential pressure signal and the variable diameter ratio.

2. The mirror sheath flow monitoring system with a bypass structure according to claim 1, characterized in that, The system also includes a gauge pressure sensor, which is connected to the first sampling port via a sampling pipeline, for acquiring real-time gauge pressure signals of the airway.

3. The mirror sheath flow monitoring system with a bypass structure according to claim 2, characterized in that, The controller is also used to perform airway pressure safety monitoring based on the real-time gauge pressure signal of the airway.

4. The mirror sheath flow monitoring system with a bypass structure according to claim 1, characterized in that, The first sampling port also serves as a gas pressure sampling end, and the second sampling port is also connected to a gas sampling pipeline via a controllable valve; The controller is also used to: control the controllable valve to close during the flow monitoring period and calculate the instantaneous flow rate based on the differential pressure signal; or control the controllable valve to open during the gas monitoring period, acquire the gas composition signal based on the gas sampling pipeline, and switch the flow algorithm to zero-order hold mode or predictive compensation mode.

5. The mirror sheath flow monitoring system with a bypass structure according to claim 4, characterized in that, The gas sampling pipeline includes a gas analyzer and a connecting pipeline. The controllable valve is installed on the connecting pipeline between the second sampling port and the gas analyzer and is connected to the controller via a control line to control the on / off state of the gas sampling pipeline.

6. A method for monitoring the flow rate of a mirror sheath with a bypass structure, applicable to the mirror sheath flow rate monitoring system with a bypass structure as described in any one of claims 1 to 5, characterized in that, The method includes: Based on the first sampling port located in the high-pressure zone upstream of the variable diameter measuring cavity and the second sampling port located in the low-pressure zone downstream of the variable diameter measuring cavity, the differential pressure signal generated at both ends of the variable diameter measuring cavity is obtained by a differential pressure sensor. The diameter ratio is determined by coordinating the maximum flow range of the target monitoring with the full scale range of the differential pressure sensor. The gas flow rate through the variable diameter measuring chamber is calculated based on the differential pressure signal and the variable diameter ratio.

7. The method for monitoring the flow rate of a mirror sheath with a bypass structure according to claim 6, characterized in that, The determination of the diameter ratio based on the maximum flow range of the target monitoring and the full scale of the differential pressure sensor includes: Based on Bernoulli's equation and the continuity equation, a correlation model for pressure difference, flow rate, and diameter ratio is established. The maximum flow range of the target monitoring and the full scale of the differential pressure sensor are obtained. Through the correlation model, the theoretical differential pressure corresponding to different diameter ratios is calculated based on the maximum flow range of the target monitoring and the full scale of the differential pressure sensor. The theoretical pressure difference is compared with the linear range of the pressure difference sensor, and a preset diameter ratio value that makes the theoretical pressure difference fall within a preset proportional range of the linear range is selected as the diameter ratio.

8. The method for monitoring the flow rate of a mirror sheath with a bypass structure according to claim 7, characterized in that, After acquiring the differential pressure signal generated across the variable diameter measuring cavity via a differential pressure sensor based on a first sampling port located in the high-pressure zone upstream of the variable diameter measuring cavity and a second sampling port located in the low-pressure zone downstream of the variable diameter measuring cavity, the method further includes: Real-time airway pressure signal is obtained through a gauge pressure sensor; Airway pressure safety monitoring is performed based on the real-time airway pressure signal.

9. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the sheath flow monitoring method with a bypass structure as described in any one of claims 6 to 8.

10. A storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the steps of the sheath flow monitoring method with a bypass structure as described in any one of claims 6 to 8.

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