A single pulse detection device, method and pulse oxygen supply apparatus for pulse oxygen supply

Abstract

The application discloses a single pulse detection device, method and pulse oxygen supply equipment for pulse oxygen supply. The device comprises a pulse oxygen supply gas pipeline, an ultrasonic wave transmitting transducer, an ultrasonic wave receiving transducer, a pressure sensor and a controller. The controller calculates a time of flight difference value according to a forward time of flight and a reverse time of flight, and determines an instantaneous flow rate according to the time of flight difference value. The controller determines a start point and an end point of a single pulse oxygen supply event according to the time of flight difference value and an output pressure, forms a pulse window and determines a pulse duration. The controller calculates a single pulse output volume based on the instantaneous flow rate within the pulse window, extracts a pressure feature as a single pulse pressure characterization parameter based on the output pressure, and verifies the effectiveness of the single pulse oxygen supply event according to a time sequence correlation and / or a numerical correlation between the pressure characterization parameter and the time of flight difference value. The application can realize the accuracy and reliability of single pulse oxygen supply detection.

Description

Technical Field

[0001] This invention relates to the field of respiratory oxygen supply detection technology, and in particular to a single-pulse detection device, method, and pulse oxygen supply equipment for pulse oxygen supply. Background Technology

[0002] Pulsed oxygen supply is an oxygen delivery method that intermittently outputs oxygen according to the user's inhalation state or a preset control strategy. It is commonly used in portable oxygen generators, respiratory support devices, or other equipment that requires conserving oxygen resources and improving oxygen supply efficiency. Compared to continuous oxygen supply, pulsed oxygen supply typically outputs a certain volume of oxygen in a shorter period of time. Therefore, the duration of a single pulse, the output volume, the output pressure, and the effectiveness of the pulse all affect the oxygen supply performance and reliability of the equipment.

[0003] In related technologies, gas flow detection can employ differential pressure, thermal, mechanical, or ultrasonic methods. Among these, ultrasonic time-of-flight detection reflects gas flow by measuring the downstream and upstream flight times of ultrasonic waves, offering advantages such as no moving parts and rapid response. Pressure sensors are also commonly used in oxygen supply systems to monitor changes in gas pressure, valve operation status, or abnormal oxygen supply conditions.

[0004] However, in pulsed oxygen supply scenarios, a single oxygen supply pulse is usually short in duration, and the changes in gas flow and pressure have obvious transient characteristics. If a single pulse is judged solely based on the flow signal or solely based on the pressure signal, it is easily affected by factors such as sensor noise, baseline drift, changes in gas path impedance, pipe bends, interface pressure, valve malfunctions or leaks, resulting in inaccurate judgment of the pulse start point, end point, duration, or output volume.

[0005] Furthermore, in pulsed oxygen supply circuits with low flow rates or small pipe diameters, the flow rate and pressure changes corresponding to a single pulse may be relatively weak, and the detection signal is easily affected by ambient temperature, gas state, sampling frequency, and gas circuit structure. Further improvements are still needed in accurately determining the pulse window of a single pulsed oxygen supply event, calculating the single pulse output volume, extracting pressure characteristics, and verifying the validity of the single pulsed oxygen supply event within that window.

[0006] Furthermore, pulsed oxygen supply scenarios differ from steady-state continuous flow detection. A single pulse typically exhibits a short duration, a steep rise, a brief peak or plateau region, and a fall that is significantly affected by gas path volume and impedance—a transient process. If a fixed threshold or a single sensor signal from steady-state flow detection is directly used to determine the pulse boundary, false triggering can easily occur at the starting point, or the window can be lengthened at the ending point due to residual pressure, wake, or filtering delay. This can lead to systematic deviations in the judgment of single pulse duration, output volume, and pulse quality.

[0007] Therefore, the present invention does not simply aim to detect the presence of gas flow, but rather to reliably identify the boundary of a single pulse event in a transient pulse waveform, and further determine whether the gas flow and pressure response within that boundary correspond to a real, complete, and effective oxygen supply pulse. Summary of the Invention

[0008] The present invention aims to at least solve the technical problems existing in the current pulse oxygen supply detection, such as inaccurate identification of the start and end points of a single pulse, insufficient reliability of the calculation of the output volume of a single pulse, and difficulty in determining whether a single pulse oxygen supply event is valid, and provides a single pulse detection device, method and pulse oxygen supply equipment for pulse oxygen supply.

[0009] To address the aforementioned technical problems, this invention provides a single-pulse detection device for pulsed oxygen supply, comprising a pulsed oxygen supply gas pipeline, an ultrasonic transmitting transducer, an ultrasonic receiving transducer, a pressure sensor, and a controller. The ultrasonic transmitting and receiving transducers are used to measure the downstream and upstream flight times of ultrasonic waves in the gas, and the pressure sensor is used to collect the output pressure during the pulsed oxygen supply process.

[0010] The controller is configured to: calculate the flight time difference based on the downstream flight time and the upstream flight time, and determine the instantaneous flow rate based on the flight time difference; determine the start and end points of a single pulse oxygen supply event to form a pulse window based on whether the flight time difference meets the flow determination condition and whether the output pressure meets the pressure change condition, and determine the duration of the single pulse; calculate the single pulse output volume based on the instantaneous flow rate within the pulse window; extract at least one pressure feature based on the output pressure within the pulse window, and use the pressure feature as a single pulse pressure characterization parameter; and verify the validity of the single pulse oxygen supply event based on whether the temporal correlation and / or numerical correlation between the single pulse pressure characterization parameter and the flight time difference within the pulse window meets a preset validity condition.

[0011] The present invention also provides a single-pulse detection method for pulsed oxygen supply, comprising: measuring the downstream flight time and the upstream flight time; acquiring the output pressure; calculating the flight time difference based on the downstream flight time and the upstream flight time, and determining the instantaneous flow rate; determining the start and end points of the single-pulse oxygen supply event based on the flight time difference and the output pressure to form a pulse window; calculating the single-pulse output volume and extracting the pressure characteristics within the pulse window, and verifying the effectiveness of the single-pulse oxygen supply event based on the correlation between the pressure characteristics and the flight time difference.

[0012] The present invention also provides a pulse oxygen supply device, which includes the above-mentioned single pulse detection device for pulse oxygen supply.

[0013] The present invention also provides an electronic device and a computer-readable storage medium for implementing the above-described single-pulse detection method.

[0014] Compared with the prior art, the present invention has at least the following beneficial effects: by obtaining the instantaneous flow rate through ultrasonic time-of-flight difference and determining the pulse window of a single pulse oxygen supply event in combination with the output pressure, the accuracy of identifying the start, end, and duration of a single pulse can be improved; by integrating the instantaneous flow rate within the pulse window, the output volume of a single pulse can be obtained; by extracting pressure features and verifying them with temporal correlation and / or numerical correlation with the time-of-flight difference, abnormal or invalid pulses can be identified, thereby improving the reliability and anti-interference capability of pulse oxygen supply detection. Attached Figure Description

[0015] The accompanying drawings, which are provided to further illustrate the invention and constitute a part of this invention, are illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention.

[0016] Figure 1 This is a schematic diagram of the process of the present invention. Detailed Implementation

[0017] The technical solutions provided by the embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that in the description of the embodiments of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B; "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. In this embodiment, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" and "second" can explicitly or implicitly include one or more of that feature. In the description of this embodiment, unless otherwise stated, "multiple" means two or more.

[0018] Example 1

[0019] A single-pulse detection device for pulsed oxygen supply includes a pulsed oxygen supply gas pipeline, an ultrasonic transmitting transducer, an ultrasonic receiving transducer, a pressure sensor, and a controller.

[0020] Pulsed oxygen supply gas pipelines are used to deliver pulsed output oxygen or oxygen-containing gas.

[0021] An ultrasonic transmitting transducer and an ultrasonic receiving transducer are installed on a pulsed oxygen supply gas pipeline to measure the downstream flight time of ultrasonic waves propagating in the gas flow direction and the upstream flight time propagating against the gas flow direction.

[0022] The pressure sensor is used to collect the output pressure during the pulse oxygen supply process. The output pressure can be the pressure in the pulse oxygen supply gas pipeline, the pressure near the outlet, or the gas path pressure related to a single pulse oxygen supply.

[0023] The controller receives the downstream flight time, the upstream flight time, and the output pressure.

[0024] The controller calculates the flight time difference based on the downstream and upstream flight times, and determines the instantaneous flow rate based on the flight time difference. The flight time difference can be the difference between the downstream and upstream flight times, or it can be the absolute value of the difference or the difference after directional correction.

[0025] For example:

[0026] TOF_forward: Flight time with the current

[0027] TOF_reverse: Time of reverse flight

[0028] Time-of-flight difference: Delta_TOF = TOF_reverse - TOF_forward

[0029] Delta_TOF is related to the gas flow rate. The system can continuously collect multiple Delta_TOF samples as the basis for pulse identification and flow rate calculation.

[0030] Then, the controller can further combine at least one of the following: sound path length, pipe cross-sectional area, sound path angle, calibration coefficient, and temperature compensation coefficient to convert the flight time difference into instantaneous flow rate.

[0031] During pulsed oxygen supply, the controller determines the start and end points of a single pulsed oxygen supply event based on whether the flight time difference meets the flow determination conditions and whether the output pressure meets the pressure change conditions.

[0032] The time interval between the start and end points forms a pulse window, and the controller determines the duration of a single pulse based on the start and end times. Therefore, subsequent volume calculations, pressure feature extraction, and validity verification are all confined to this pulse window to reduce the impact of noise during non-pulse periods on the detection results.

[0033] To establish a verifiable technical loop for start-point and end-point determination, the controller can divide the single pulse detection process into four states: idle state, start-point confirmation state, pulse window state, end-point confirmation state, and validity verification state. In the idle state, the controller primarily learns the flight time difference, the baseline of output pressure, and the noise level. In the start-point confirmation state, the controller confirms the pulse start based on flow start conditions, pressure start conditions, and a synchronous upward trend. In the pulse window state, the controller continuously records instantaneous flow rate and output pressure. In the end-point confirmation state, the controller confirms the pulse end based on at least one of the flow end conditions and pressure end conditions. In the validity verification state, the controller uses the correspondence between the flow response and pressure response within the pulse window to determine whether the pulse is valid.

[0034] After determining the pulse window, multiple instantaneous flow rate samples are acquired within the pulse window in the order of sampling time, and a trapezoidal area is calculated based on two adjacent instantaneous flow rate samples and the corresponding sampling interval.

[0035] The output volume of a single pulse is obtained by summing the areas of multiple trapezoids within the pulse window;

[0036] The output volume of a single pulse is calculated using the following formula:

[0037]

[0038] Let i be the instantaneous flow rate at the i-th sampling point. Let be the instantaneous flow rate at the (i-1)th sampling point, and Δt be the sampling interval between two adjacent sampling points. The summation range is the sampling points within the pulse window.

[0039] In summary, the oxygen supply within the pulse window can be obtained.

[0040] In one method of determining the starting point, the controller counts the number of sampling points that meet the starting point determination criteria within a sliding window.

[0041] The starting point determination conditions include: the flight time difference meets the flow starting point condition, the output pressure meets the pressure starting point condition, and both the flight time difference and the output pressure show an upward trend within the preset synchronization time window.

[0042] The upward trend can be due to the current sampled value being greater than the previous sampled value, the slope after filtering being greater than a preset slope threshold, or the average value of the later segment within a preset synchronization time window being greater than the average value of the earlier segment. When the number of sampling points within the sliding window that meet the starting point determination condition reaches a preset value, the controller confirms that a single pulse oxygen supply event has occurred and determines the first sampling point within the sliding window that meets the starting point determination condition, causing the number of sampling points to reach the preset value, as the starting point of the single pulse oxygen supply event. This method can avoid false triggering caused by a single noise point, and at the same time, by determining the starting point through backtracking, it reduces the underestimation of pulse duration and output volume.

[0043] The starting point employs a combination of flow and pressure starting conditions, primarily to eliminate single-signal disturbances. For example, a sudden increase in the flight time difference might originate from ultrasonic measurement noise or local airflow disturbances, while a sudden rise in output pressure might stem from valve action pressure waves, external compression, or sensor zero-point drift. Only when both conditions show an upward trend within a preset synchronization time window does it better reflect the physical process of a real pulsed oxygen supply event transitioning from the baseline state to the output state.

[0044] For example:

[0045] The sliding window length N = 5 (i.e., simultaneously viewing 5 consecutive sampling points); at least M = 3 sampling points must simultaneously meet the condition of "TOF exceeding the threshold and pressure rising" before the pulse is confirmed to start.

[0046] Errors related to no sliding window:

[0047] The third sampling point suddenly spiked due to noise, meeting the condition → the system immediately determined that the pulse had started → but it was actually a false alarm.

[0048] In the case of a sliding window:

[0049] Sampling points within the window:

[0050] [Point 1, Point 2, Point 3, Point 4, Point 5]

[0051] Assuming only point 3 meets the condition, while the other 4 points do not → the number of points that meet the condition is 1 < M=3 → the pulse start is not confirmed → thus avoiding misjudgment.

[0052] When the window slides to the next group:

[0053] [Point 2, Point 3, Point 4, Point 5, Point 6]

[0054] If points 4, 5, and 6 also meet the conditions → the number of conditions met = 3 ≥ 3 → confirm the start of the pulse.

[0055] In one endpoint determination method, after confirming the start point of a single pulse oxygen supply event, the controller detects sampling points that meet the endpoint determination criteria. When it is detected that each sampling point in a consecutive preset number of sampling points meets any endpoint determination criterion, the controller confirms the end of the single pulse oxygen supply event and determines the first sampling point in the consecutive preset number of sampling points that meets any endpoint determination criterion as the endpoint of the single pulse oxygen supply event.

[0056] The endpoint determination criteria may include at least one of the following:

[0057] 1. The flight time difference satisfies the flow termination condition;

[0058] 2. The output pressure meets the pressure termination condition.

[0059] Therefore, the endpoint can be triggered by the fallback of the flow signal, the fallback of the pressure signal, or any effective fallback signal of both, adapting to different gas path structures, sensor response speeds, and pulse tail morphologies. In other embodiments, the flow termination condition and the pressure termination condition can also be required to be met simultaneously to further improve the reliability of endpoint confirmation.

[0060] The endpoint is triggered by either a flow termination condition, primarily to accommodate the asynchronous fallback characteristics of the pulse descent phase. After the oxygen supply valve closes, the time-of-flight difference may fall back first due to the rapid decay of the actual flow, while the output pressure may fall back later due to pipeline volume, interface impedance, or downstream load; conversely, the output pressure may fall back first, while the time-of-flight difference remains for a period due to wake or filtering delay. Forcing both termination conditions to be met simultaneously could unnecessarily prolong the pulse window. Therefore, this embodiment allows either the flow termination condition or the pressure termination condition to be met, and suppresses transient noise by confirming this through a continuously preset number of sampling points.

[0061] In this embodiment, the starting point is determined by satisfying both the flow starting point condition and the pressure starting point condition, while the ending point is determined by satisfying either the flow ending condition or the pressure ending condition.

[0062] The time-of-flight difference and output pressure during pulsed oxygen supply typically exhibit a pulse-wave-shaped curve. This means that the pressure rises near the baseline at the beginning of a single pulse, reaches a peak or plateau during pulse output, and gradually decreases or falls back to near the baseline at the end of the pulse. Based on this pulse-wave-shaped curve, the start-point determination focuses on whether both the time-of-flight difference and output pressure show an upward trend within a preset synchronization time window to confirm that the single-pulse oxygen supply event has transitioned from the baseline state to the effective output state. Since a false start-point trigger can cause the pulse window to open prematurely, affecting the calculation of the single-pulse output volume and validity verification, the start-point is confirmed by the synchronous rise of the time-of-flight difference and output pressure. In contrast, at the end of a single-pulse oxygen supply event, the time-of-flight difference and output pressure may decline asynchronously due to gas inertia, pipeline volume, gas path impedance, sensor response speed, or filtering delay. Requiring both to simultaneously meet the termination condition could prolong the pulse window. Therefore, the endpoint determination allows either the flow termination condition or the pressure termination condition to be met, and confirms this with a continuously preset number of sampling points to suppress transient noise while promptly closing the pulse window.

[0063] In one optimization approach, the controller continuously acquires flight time difference and output pressure during idle, pulse-free operation to determine the flight time difference baseline and pressure baseline, respectively. The idle, pulse-free state can be identified by the oxygen supply valve being closed, the flight time difference being below a preset low-flow threshold, the output pressure being within a stable range, or the equipment being in standby mode. The flight time difference baseline and pressure baseline can be determined using moving averages, median filtering, exponential smoothing, or statistical values ​​after outlier removal. The controller further determines the flight time difference noise level based on the fluctuation level of the flight time difference relative to the flight time difference baseline, and determines the pressure noise level based on the fluctuation level of the output pressure relative to the pressure baseline.

[0064] The controller can dynamically update the flow determination conditions and / or pressure change conditions used to determine the start and / or end points based on the flight time difference baseline, pressure baseline, flight time difference noise level, and pressure noise level.

[0065] During dynamic updates, the controller can update the time-of-flight difference baseline and pressure baseline only in the idle, pulse-free state, and pause or reduce the baseline update weight after it has been confirmed that the pulse window has been entered, so as to avoid real pulse signals being absorbed into the baseline.

[0066] Furthermore, the controller can also denot the deviation of the time-of-flight difference (TOF) from the TOF baseline as D_TOF, and the deviation of the output pressure from the pressure baseline as D_P. The flow initiation condition can include D_TOF being greater than a first coefficient multiple of the TOF noise level, and the pressure initiation condition can include D_P being greater than a second coefficient multiple of the pressure noise level. The flow termination condition can include D_TOF being less than a third coefficient multiple of the TOF noise level, and the pressure termination condition can include D_P being less than a fourth coefficient multiple of the pressure noise level. The first and second coefficients can be greater than the third and fourth coefficients to form a hysteresis interval between the initiation and termination points, reducing boundary jitter.

[0067] For example:

[0068] The time-of-flight difference noise level is 1;

[0069] The pressure noise level is 2;

[0070] The starting point judgment requirements are more stringent, such as exceeding 3 times the noise level;

[0071] The endpoint determination requires the noise level to drop to a relatively low level, such as below 1.5 times the noise level.

[0072] So:

[0073] A flow is considered to be beginning to be noticeable only when D_TOF > 3 × noise.

[0074] Pressure is considered to be starting to become noticeable only when D_P > 3 × noise.

[0075] If D_TOF < 1.5 × noise, the flow can be considered to have ended;

[0076] If D_P < 1.5 × noise, the pressure can be considered to have ended.

[0077] If both the start threshold and the end threshold are set to 2, the signal may fluctuate between 2 and 2, causing the system to repeatedly check "start, end, start, end".

[0078] If the start threshold is set to 3 and the end threshold is set to 1.5, then the signal will only start when it rises significantly and end when it falls significantly, and small fluctuations in between will not cause the state to jump around randomly.

[0079] In summary, its technical implications are as follows:

[0080] A higher threshold is used to determine the start point to ensure that the pulse truly begins; a lower threshold is used to determine the end point to ensure that the pulse actually falls back; a hysteresis interval is left between the two to reduce start and end point jitter caused by noise.

[0081] That is, the controller can determine the flow start threshold and flow end threshold based on the flight time difference noise level, and determine the pressure start threshold and pressure end threshold based on the pressure noise level. The flow start threshold is greater than the flow end threshold, and the pressure start threshold is greater than the pressure end threshold. This results in the start threshold for a single pulse oxygen supply event being higher than the end threshold for the return to the starting point, thus creating a hysteresis interval between the start and end point determinations, reducing boundary jitter caused by sensor noise or transient disturbances.

[0082] Specifically, the controller determines the flow start threshold and flow end threshold based on the flight time difference baseline and flight time difference noise level, and determines the pressure start threshold and pressure end threshold based on the pressure baseline and pressure noise level.

[0083] The flow start threshold is used to determine whether the flight time difference meets the flow start condition, the pressure start threshold is used to determine whether the output pressure meets the pressure start condition, the flow end threshold is used to determine whether the flight time difference meets the flow end condition, and the pressure end threshold is used to determine whether the output pressure meets the pressure end condition.

[0084] Dynamic updates can reduce the impact of baseline drift, environmental changes, pipeline condition changes, and sensor noise on pulse boundary identification.

[0085] In the above embodiments, the controller extracts at least one pressure feature based on the output pressure within the pulse window and uses the pressure feature as a single pulse pressure characterization parameter.

[0086] The pressure characteristics described here can include at least one of the following: pressure amplitude characteristics, pressure time characteristics, and pressure change characteristics. Pressure amplitude characteristics can include peak pressure, average pressure, and maximum pressure increment; pressure time characteristics can include pressure rise time, pressure fall time, and pressure peak time; pressure change characteristics can include pressure integral, pressure change slope, and pressure difference before and after the pulse. These pressure characteristics are used to characterize the gas path pressure response during a single pulse.

[0087] In this embodiment, the controller verifies the validity of a single-pulse oxygen supply event based on whether the temporal correlation and / or numerical correlation between the single-pulse pressure characterization parameter and the time-of-flight difference within the pulse window meets preset validity conditions. This is because a truly effective pulse oxygen supply event typically causes simultaneous changes in gas flow and gas path pressure. The time-of-flight difference reflects the gas flow state, and the output pressure reflects the gas path pressure response state. If a single pulse is indeed formed by the opening of the oxygen supply valve, gas output, and gas path response, then the time-of-flight difference and pressure characteristics within the pulse window usually have a certain temporal and numerical correspondence. For example, their change intervals at least partially overlap in time, their peak times are close to each other, their integral or normalized characteristic values ​​are within a preset ratio range, or they exhibit a consistent trend during the ascent and descent phases. Conversely, if only the time-of-flight difference changes without a corresponding change in pressure characteristics, it may indicate a leak, abnormal pressure sensing, or failure to establish effective pressure in the gas path. If only the output pressure changes without a corresponding change in the time-of-flight difference, it may indicate a blockage in the gas path, valve malfunction, interface pressure, abnormal ultrasonic measurements, or other abnormal gas path impedance. Therefore, validating the relationship between pressure characterization parameters and the time-of-flight difference through temporal and / or numerical correlations allows for further assessment of whether a single pulse is a genuine, complete, and effective oxygen supply pulse, based on the identified pulse window. This improves the reliability of single-pulse output volume, pulse quality assessment, and anomaly identification results.

[0088] In one scoring implementation, the controller can obtain multiple sub-scores based on the overlap of variation intervals, peak time difference, normalized integral ratio, and trend correlation coefficient, and then perform a weighted summation of these sub-scores to obtain the pulse quality score. When the pulse quality score is lower than a preset scoring threshold, the controller can mark the single pulse oxygen supply event as an abnormal pulse or an invalid pulse; when the pulse quality score is higher than the preset scoring threshold, the controller can mark the single pulse oxygen supply event as a valid pulse. This method avoids making rigid judgments based solely on a single threshold, thereby improving adaptability under different gas path loads and different pulse amplitudes.

[0089] In one optimization method, the preset validity conditions include at least one of the following:

[0090] 1. The range of variation in output pressure and the range of variation in flight time difference at least partially overlap in time;

[0091] 2. The time difference between the peak pressure and the peak flight time is less than the preset time difference;

[0092] 3. The ratio, difference, or correlation coefficient between the integral of the output pressure, the normalized integral, or the integral of the pressure characteristic value and the difference between the flight time, the normalized integral, or the flow characteristic value are within the preset range.

[0093] 4. The output pressure and flight time difference show a consistent trend during the ascent, descent, or overall pulse window.

[0094] The above conditions can also be selected in combination, thereby further improving the accuracy of distinguishing between real and effective oxygen supply pulses and false pulses caused by sensor noise, air leakage, blockage or valve abnormality.

[0095] In one anomaly detection method, when the time-of-flight difference meets the flow determination condition but the output pressure does not meet the pressure change condition, the controller outputs a leakage anomaly warning and / or a pressure sensing anomaly warning. When the output pressure meets the pressure change condition but the time-of-flight difference does not meet the flow determination condition, the controller outputs an air path anomaly warning and / or an ultrasonic measurement anomaly warning.

[0096] Furthermore, anomaly alerts can be differentiated based on the specific correspondence within the pulse window. For example, if there is a significant pulse shape change in the time-of-flight difference but insufficient output pressure change, it can primarily indicate air leakage, pressure sensor malfunction, or downstream opening malfunction. If there is a significant pulse shape change in the output pressure but insufficient time-of-flight difference, it can primarily indicate upstream or downstream gas path blockage, valve not fully open, pipeline pressure, ultrasonic transducer coupling malfunction, or ultrasonic measurement malfunction. If both change but the peak timing difference is too large or the normalized integral ratio is abnormal, it can indicate abnormal gas path impedance, abnormal load, or decreased pulse quality.

[0097] The gas path abnormality can include at least one of the following: upstream gas path blockage, downstream gas path blockage, pipeline bend, valve malfunction, interface pressure, abnormal gas path impedance, or abnormal gas load. The controller can also output corresponding error codes and / or pulse quality scores based on the validity of a single pulse oxygen supply event and the abnormality indication result.

[0098] In one implementation, the inner diameter of the pulsed oxygen supply gas pipeline is less than 5 mm. This range is chosen to align with the pipeline parameter settings within the overall size of current portable oxygen concentrators. The smaller inner diameter makes the flow velocity changes under short pulses and low flow rates more pronounced, thereby amplifying the time-of-flight difference and improving its detectability. Alternatively, the pulsed oxygen supply gas pipeline can incorporate a variable cross-sectional area structure, such as a reduced-diameter section, a Venturi section, or a local acceleration section, to enhance local flow velocity changes and improve the sensitivity of the ultrasonic time-of-flight difference response to a single pulse flow.

[0099] In one embodiment, the device further includes a temperature sensor. The controller acquires the temperature value collected by the temperature sensor and performs temperature compensation on the instantaneous flow rate and / or single pulse output volume based on the temperature value. Temperature compensation can be used to correct for gas sound velocity, gas density, or conversion factors, thereby improving detection consistency under different ambient temperatures.

[0100] In one implementation, the controller determines the ultrasonic velocity based on the downstream and upstream flight times, and within each pulse window, calculates a single-pulse oxygen concentration measurement based on the ultrasonic velocity, temperature, output pressure, and a preset gas composition model. The preset gas composition model can be a sound velocity-temperature-pressure-composition relationship model based on at least one gas component among oxygen, nitrogen, and water vapor, or a lookup table model or fitting model established using calibration data. The controller can average the single-pulse oxygen concentration measurements from multiple consecutive pulses to obtain an average oxygen concentration, thereby reducing the impact of single-pulse disturbances on the oxygen concentration measurement results.

[0101] During oxygen concentration calculation, the controller can prioritize pulse windows that have been validated for effectiveness, or reduce the weight of oxygen concentration measurements corresponding to invalid or abnormal pulses, or remove them altogether. This reduces the impact of abnormal gas path conditions, invalid pulses, or sensor disturbances on the average oxygen concentration result. The preset gas component model can be obtained through standard gas calibration, or established through table lookup, piecewise fitting, or multi-parameter regression.

[0102] Example 2

[0103] A single-pulse detection method for pulsed oxygen supply, which can be executed by the aforementioned controller, includes the following steps.

[0104] Step S1: Collect flight time and output pressure.

[0105] In a pulsed oxygen supply gas pipeline, the downstream and upstream flight times of ultrasonic waves in the gas are measured using ultrasonic transmitting and receiving transducers, and the output pressure during the pulsed oxygen supply process is collected using a pressure sensor. The controller acquires the downstream flight time, upstream flight time, and output pressure according to a preset sampling period and records the corresponding sampling time for each sample value.

[0106] Step S2: Calculate the flight time difference and instantaneous flow rate.

[0107] The controller calculates the flight time difference based on the downstream flight time and the upstream flight time. The flight time difference is used to characterize the flow state of the gas in the pulsed oxygen supply gas pipeline. The controller further determines the instantaneous flow rate corresponding to each sampling moment based on at least one of the flight time difference, sound path length, pipeline cross-sectional area, sound path angle, and calibration coefficient.

[0108] Step S3: Determine or update the flow determination conditions and pressure change conditions.

[0109] When executing step S3, if the controller is already in the pulse window state, it can pause baseline updates or update the baseline with a smaller update weight. If the controller is in an idle, pulse-free state and the time-of-flight difference and output pressure are both within a stable range, the controller updates the baseline and noise level with a larger update weight. This allows for a balance between long-term drift compensation and pulse signal maintenance.

[0110] In the idle, pulse-free state, the controller continuously collects the flight time difference and output pressure, respectively determining the flight time difference baseline and pressure baseline. Based on the fluctuation levels of the flight time difference relative to the flight time difference baseline and the output pressure relative to the pressure baseline, the controller determines the flight time difference noise level and pressure noise level, respectively. Based on the flight time difference baseline, pressure baseline, flight time difference noise level, and pressure noise level, the controller dynamically updates the flow determination conditions and / or pressure change conditions used to determine the start and / or end points of a single pulse oxygen supply event.

[0111] In one specific implementation, the controller determines a flow initiation threshold and a flow termination threshold based on the flight time difference baseline and the flight time difference noise level, and determines a pressure initiation threshold and a pressure termination threshold based on the pressure baseline and the pressure noise level. The flow initiation threshold is used to determine whether the flight time difference meets the flow initiation condition, the pressure initiation threshold is used to determine whether the output pressure meets the pressure initiation condition, the flow termination threshold is used to determine whether the flight time difference meets the flow termination condition, and the pressure termination threshold is used to determine whether the output pressure meets the pressure termination condition.

[0112] Step S4: Determine the starting point of a single pulse oxygen supply event.

[0113] The controller counts the number of sampling points that meet the starting point determination criteria within a sliding window. These criteria include: the flight time difference meets the flow starting point condition, the output pressure meets the pressure starting point condition, and both the flight time difference and the output pressure show an increasing trend within a preset synchronization time window.

[0114] In one specific manner, the flight time difference satisfying the flow initiation condition includes: the deviation of the flight time difference from the flight time difference baseline exceeds the flow initiation threshold; the output pressure satisfying the pressure initiation condition includes: the deviation of the output pressure from the pressure baseline exceeds the pressure initiation threshold. The upward trend can be that the slopes of both the flight time difference and the output pressure are greater than their corresponding slope thresholds, or that the average value of both within a preset synchronization time window is greater than the average value within the preceding period.

[0115] When the number of sampling points within the sliding window that meet the starting point determination condition reaches a preset value, the controller confirms that a single pulse oxygen supply event has occurred, and determines the first sampling point within the sliding window that meets the starting point determination condition, which causes the number of sampling points to reach the preset value, as the starting point of the single pulse oxygen supply event.

[0116] Step S5: Determine the endpoint of a single pulse oxygen supply event.

[0117] After confirming the start point of a single pulse oxygen supply event, the controller continues to detect sampling points that meet the endpoint determination criteria. When it is detected that each sampling point in a consecutive preset number of sampling points meets any endpoint determination criterion, the controller confirms that the single pulse oxygen supply event has ended, and determines the first sampling point in the consecutive preset number of sampling points that meets any endpoint determination criterion as the endpoint of the single pulse oxygen supply event.

[0118] The endpoint determination criteria include at least one of the following: the flight time difference meets the flow termination condition; the output pressure meets the pressure termination condition. In one specific embodiment, the flight time difference meeting the flow termination condition includes the flight time difference being lower than a flow termination threshold, or the deviation between the flight time difference and the flight time difference baseline being less than a first fallback threshold; the output pressure meeting the pressure termination condition includes the output pressure being lower than a pressure termination threshold, or the deviation between the output pressure and the pressure baseline being less than a second fallback threshold.

[0119] In this embodiment, the starting point determination requires both the flow starting point condition and the pressure starting point condition to be met, and further requires that both rise synchronously to avoid false triggering due to noise from a single sensor, pressure disturbance, or flow perturbation. The ending point determination allows either the flow ending condition or the pressure ending condition to be met because the undulating curve of pulsed oxygen supply typically undergoes a process of rising from near the baseline, reaching a peak or plateau region, and then gradually decreasing. During the decreasing phase, the time-of-flight difference and output pressure may fall asynchronously due to differences in gas inertia, pipeline volume, gas path impedance, or sensor response speed. Therefore, using either ending condition in conjunction with confirmation from a continuously preset number of sampling points allows for timely closure of the pulse window and reduces the risk of the pulse window being prolonged.

[0120] Step S6: Form a pulse window and determine the duration of a single pulse.

[0121] The controller forms a pulse window based on the start point and the end point, and determines the duration of a single pulse based on the sampling time corresponding to the start point and the sampling time corresponding to the end point.

[0122] Step S7: Calculate the output volume of a single pulse.

[0123] The controller acquires multiple instantaneous flow rate samples in the pulse window according to the sampling time sequence, calculates the trapezoidal area based on two adjacent instantaneous flow rate samples and their corresponding sampling intervals, and accumulates the multiple trapezoidal areas to obtain the single pulse output volume. The single pulse output volume can be calculated using the following formula:

[0124]

[0125] Let i be the instantaneous flow rate at the i-th sampling point. Let be the instantaneous flow rate at the (i-1)th sampling point, and Δt be the sampling interval between two adjacent sampling points. The summation range is the sampling points within the pulse window.

[0126] Step S8: Extract the single-pulse pressure characterization parameters.

[0127] The controller extracts at least one pressure feature based on the output pressure within the pulse window and uses the pressure feature as a single-pulse pressure characterization parameter. The pressure feature includes at least one of pressure amplitude feature, pressure time feature, and pressure change feature. The pressure amplitude feature includes peak pressure and / or average pressure; the pressure time feature includes pressure rise time and / or pressure fall time; and the pressure change feature includes pressure integral and / or pressure difference before and after the pulse.

[0128] Step S9: Verify the effectiveness of a single pulse oxygen supply event.

[0129] During step S9, the controller can first perform time alignment and normalization on the flight time difference curve and the output pressure curve, and then calculate their correlation within the pulse window. The time alignment allows for a preset delay in the pressure response relative to the flow response to accommodate the phase difference caused by the pressure sensor response time and the gas path volume. Normalization transforms the curves at different pulse amplitudes to a comparable scale, thereby improving the effectiveness verification's adaptability to changes in oxygen supply levels.

[0130] The controller verifies the validity of a single-pulse oxygen supply event based on whether the temporal correlation and / or numerical correlation between the single-pulse pressure characterization parameters and the flight time difference within the pulse window meets preset validity conditions. The preset validity conditions include at least one of the following: the range of output pressure variation and the range of flight time difference variation at least partially overlap in time; the time difference between the peak time of output pressure and the peak time of the flight time difference is less than a preset time difference; the ratio, difference, or correlation coefficient between the integral, normalized integral, or pressure characteristic value of output pressure and the integral, normalized integral, or flow characteristic value of flight time difference are within a preset range; and the trends of output pressure and flight time difference are consistent during the rising phase, falling phase, or the overall pulse window.

[0131] When the preset validity condition is met, the controller determines that the single pulse oxygen supply event is a valid pulse; when the preset validity condition is not met, the controller determines that the single pulse oxygen supply event is an abnormal pulse or an invalid pulse.

[0132] Step S10: Output the detection results and anomaly alerts.

[0133] The controller outputs the duration of a single pulse, the output volume of a single pulse, the pressure characterization parameters of a single pulse, and the validity verification results. When the time-of-flight difference meets the flow determination condition but the output pressure does not meet the pressure change condition, the controller outputs a leakage abnormality warning and / or a pressure sensor abnormality warning; when the output pressure meets the pressure change condition but the time-of-flight difference does not meet the flow determination condition, the controller outputs a gas path abnormality warning and / or an ultrasonic measurement abnormality warning. The controller can also output corresponding error codes and / or pulse quality scores based on the validity of the single pulse oxygen supply event and the abnormality warning results.

[0134] In a further embodiment, the controller can also perform temperature compensation on the instantaneous flow rate and / or single pulse output volume based on the temperature value collected by the temperature sensor; it can also determine the ultrasonic velocity based on the downstream flight time and the upstream flight time, and calculate the single pulse oxygen concentration measurement value based on the ultrasonic velocity, temperature, output pressure and preset gas composition model in each pulse window, and then take the average value of the single pulse oxygen concentration measurement values ​​of multiple consecutive pulses to obtain the average oxygen concentration.

[0135] Example 3

[0136] A pulsed oxygen supply device includes an oxygen source, an oxygen supply control valve, a pulsed oxygen supply gas pipeline, and a single-pulse detection device as described in any of the foregoing embodiments. The oxygen source can be an oxygen generation module, an oxygen cylinder, or other oxygen-containing gas supply module. The oxygen supply control valve is used to open and close according to a preset oxygen supply strategy or a user inhalation trigger signal to form a single-pulse oxygen supply event.

[0137] A single-pulse detection device is installed on the pulsed oxygen supply gas pipeline to detect the downstream flight time, upstream flight time, and output pressure during each pulsed oxygen supply process. It also determines the start and end points, pulse duration, single-pulse output volume, and validity verification results of each pulsed oxygen supply event. The pulsed oxygen supply equipment can adjust the opening time, pulse frequency, or alarm status of the oxygen supply control valve based on the single-pulse output volume, pressure characterization parameters, error codes, and / or pulse quality scores, thereby improving the accuracy and reliability of pulsed oxygen supply.

[0138] Example 4

[0139] An electronic device includes a processor and a memory. The memory stores a computer program that, when executed by the processor, causes the processor to perform the steps of the aforementioned single-pulse detection method for pulsed oxygen supply.

[0140] The processor can be a microcontroller, digital signal processor, application-specific integrated circuit, field-programmable gate array, or other processing unit capable of executing control programs. The memory can be non-volatile memory, volatile memory, or a combination thereof. The electronic device can be integrated into the main control board of the pulse oxygen supply equipment, or it can be used as an independent detection module communicating with the pulse oxygen supply equipment.

[0141] Example 5

[0142] A computer-readable storage medium has a computer program stored thereon. When the computer program is executed by a processor, it implements the steps of the aforementioned single-pulse detection method for pulsed oxygen supply, including acquiring downstream flight time, upstream flight time, and output pressure; calculating the flight time difference and instantaneous flow rate; determining the start and end points of a single-pulse oxygen supply event; forming a pulse window; calculating the single-pulse output volume; extracting pressure characteristics; and validating the single-pulse oxygen supply event.

[0143] The computer-readable storage medium may include a read-only memory, a random access memory, flash memory, a memory card, a disk, an optical disk, or other media capable of storing program instructions.

[0144] It should be understood that the combination of technical features in the above embodiments does not imply the order of execution. The combination of technical features should be determined by their functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

Claims

1. A single-pulse detection device for pulsed oxygen supply, characterized in that, include: Pulsed oxygen supply gas pipeline; Ultrasonic transmitting transducers and ultrasonic receiving transducers are used to measure the downstream and upstream flight times of ultrasonic waves in a gas. A pressure sensor is used to collect the output pressure during the pulsed oxygen supply process; The controller is configured as follows: The flight time difference is calculated based on the downstream flight time and the upstream flight time, and the instantaneous flow rate is determined based on the flight time difference. Based on whether the flight time difference meets the flow determination condition and whether the output pressure meets the pressure change condition, the start and end points of a single pulse oxygen supply event are determined to form a pulse window, and the duration of a single pulse is determined. The output volume of a single pulse is calculated based on the instantaneous flow rate within the pulse window; Within the pulse window, at least one pressure feature is extracted based on the output pressure, and the pressure feature is used as a single pulse pressure characterization parameter. The validity of the single-pulse oxygen supply event is verified based on whether at least one of the temporal correlation and / or numerical correlation between the single-pulse pressure characterization parameter and the flight time difference within the pulse window meets a preset validity condition.

2. The apparatus according to claim 1, characterized in that, The controller is also configured to: The number of sampling points that meet the starting point determination conditions is counted within a sliding window. The starting point determination conditions include: the flight time difference meets the flow starting point condition, the output pressure meets the pressure starting point condition, and both the flight time difference and the output pressure show an upward trend within a preset synchronization time window. When the number of sampling points reaches a preset value, the occurrence of the single pulse oxygen supply event is confirmed, and the first sampling point in the sliding window that makes the number of sampling points reach the preset value and meets the starting point determination condition is determined as the starting point of the single pulse oxygen supply event.

3. The apparatus according to claim 1, characterized in that, The controller is also configured to: After confirming the starting point of the single pulse oxygen supply event, the sampling points that meet the endpoint determination criteria are detected. When it is detected that each sampling point in a consecutive preset number of sampling points meets any of the aforementioned endpoint determination conditions, the single pulse oxygen supply event is confirmed to have ended, and the first sampling point in the consecutive preset number of sampling points that meets any of the aforementioned endpoint determination conditions is determined as the endpoint of the single pulse oxygen supply event. The endpoint determination criteria include at least one of the following: The flight time difference satisfies the flow termination condition; The output pressure meets the pressure termination condition.

4. The apparatus according to claim 1, characterized in that, The controller is also configured to: In an idle, pulse-free state, the flight time difference and the output pressure are continuously collected to determine the flight time difference baseline and the pressure baseline, respectively. Based on the fluctuation level of the time-of-flight difference relative to the time-of-flight difference baseline and the fluctuation level of the output pressure relative to the pressure baseline, the time-of-flight difference noise level and the pressure noise level are determined respectively. The flow determination conditions and / or pressure change conditions used to determine the starting point and / or the ending point are dynamically updated based on the flight time difference baseline, the pressure baseline, the flight time difference noise level, and the pressure noise level.

5. The apparatus according to claim 4, characterized in that, The dynamic update includes: Configure the flow determination condition used to determine the starting point as a flow starting point condition, and configure the pressure change condition used to determine the starting point as a pressure starting point condition; Configure the flow determination condition used to determine the endpoint as a flow termination condition, and configure the pressure change condition used to determine the endpoint as a pressure termination condition; Based on the time-of-flight difference baseline and the time-of-flight difference noise level, determine the flow start threshold for the flow start condition and the flow end threshold for the flow end condition. Based on the pressure baseline and the pressure noise level, determine the pressure start threshold for the pressure start condition and the pressure end threshold for the pressure end condition. Wherein, the flow start threshold is greater than the flow end threshold, and the pressure start threshold is greater than the pressure end threshold.

6. The apparatus according to claim 1, characterized in that, The preset validity conditions include at least one of the following: The range of change in output pressure and the range of change in flight time difference at least partially overlap in time. The time difference between the peak time of the output pressure and the peak time of the flight time difference is less than a preset time difference; The ratio, difference, or correlation coefficient between the integral, normalized integral, or pressure characteristic value of the output pressure and the integral, normalized integral, or flow characteristic value of the flight time difference are within a preset range. The output pressure and the flight time difference show a consistent trend during the ascent, descent, or overall pulse window.

7. The apparatus according to claim 1, characterized in that, The controller is also configured to: Within the pulse window, multiple instantaneous flow rate sampling values ​​are acquired in sequence according to the sampling time, and a trapezoidal area is calculated based on two adjacent instantaneous flow rate sampling values ​​and the corresponding sampling interval. The output volume of a single pulse is obtained by summing the areas of multiple trapezoids within the pulse window. The output volume of a single pulse is calculated according to the following formula: Let i be the instantaneous flow rate at the i-th sampling point. Let be the instantaneous flow rate at the (i-1)th sampling point, and Δt be the sampling interval between two adjacent sampling points. The summation range is the sampling points within the pulse window.

8. The apparatus according to claim 1, characterized in that, The pressure characteristics include at least one of pressure amplitude characteristics, pressure time characteristics, and pressure change characteristics; wherein, the pressure amplitude characteristics include peak pressure and / or average pressure, the pressure time characteristics include pressure rise time and / or pressure fall time, and the pressure change characteristics include pressure integral and / or pressure difference before and after the pulse.

9. The apparatus according to claim 1, characterized in that, The controller is also configured to: The effectiveness of the single-pulse oxygen supply event is determined based on at least one of the following: the temporal correspondence, numerical correspondence, or trend correspondence between the single-pulse pressure characterization parameter and the flight time difference within the pulse window. When the time-of-flight difference meets the flow determination condition and the output pressure does not meet the pressure change condition, an output leakage abnormality warning and / or a pressure sensing abnormality warning will be issued. When the output pressure meets the pressure change condition and the flight time difference does not meet the flow determination condition, an output gas path abnormality and / or ultrasonic measurement abnormality is indicated. Based on whether the single pulse oxygen supply event is valid and the abnormal prompt result, the corresponding error code and / or pulse quality score are output.

10. The apparatus according to claim 1, characterized in that, The inner diameter of the pulsed oxygen supply gas pipeline is less than 5 mm, or the pulsed oxygen supply gas pipeline includes a variable cross-sectional area structure for locally enhancing the airflow velocity.

11. The apparatus according to claim 1, characterized in that, It also includes a temperature sensor, and the controller is further configured to: Obtain the temperature value from the temperature sensor; Temperature compensation is applied to the instantaneous flow rate and / or pulse output volume based on the temperature value.

12. The apparatus according to claim 1, characterized in that, The controller is also configured to: The speed of sound is determined based on the downstream flight time and the upstream flight time. Within each pulse window, the single-pulse oxygen concentration measurement value is calculated based on the ultrasonic velocity, temperature, output pressure, and preset gas composition model. The average oxygen concentration is obtained by averaging the single-pulse oxygen concentration measurements from multiple consecutive pulses.

13. A method for detecting a single pulse in pulsed oxygen supply, characterized in that, Includes the following steps: Ultrasonic waves are emitted and received in a pulsed oxygen supply gas pipeline to measure the downstream flight time and the upstream flight time. Collect the output pressure during the pulsed oxygen supply process; The flight time difference is calculated based on the downstream flight time and the upstream flight time, and the instantaneous flow rate is determined based on the flight time difference. Based on whether the flight time difference meets the flow determination condition and whether the output pressure meets the pressure change condition, the start and end points of a single pulse oxygen supply event are determined to form a pulse window, and the duration of a single pulse is determined. The output volume of a single pulse is calculated based on the instantaneous flow rate within the pulse window; Within the pulse window, at least one pressure feature is extracted based on the output pressure, and the pressure feature is used as a single pulse pressure characterization parameter. The validity of the single-pulse oxygen supply event is verified by whether the temporal correlation and / or numerical correlation between the single-pulse pressure characterization parameter and the flight time difference within the pulse window meets the preset validity conditions.

14. A pulse oxygen supply device, characterized in that, Includes the single-pulse detection device for pulsed oxygen supply as described in any one of claims 1 to 12.

15. An electronic device, characterized in that, It includes a processor and a memory, the memory storing a computer program that, when executed by the processor, implements the steps of the method of claim 13.

16. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method of claim 13.

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