A method for filtering out fan interference from ventilator airway signals

Abstract

The present invention discloses a method for filtering out fan interference from a ventilator airway signal, which belongs to the field of ventilators. The method comprises the steps of obtaining a transfer function of a ventilator airway system, collecting a signal during use of the ventilator airway system, calculating a signal generated by an airflow control element in the airway during the wearer's breathing process, and calculating a human respiratory signal with the fan interference filtered out during the wearer's breathing process. The method filters out interference in the airway caused by the constantly changing output intensity of the airflow control element, and obtains a relatively pure wearer's respiratory action signal. Only sensors arranged in the ventilator airway are used, and the wearer does not need to wear additional sensors to separately monitor the respiratory action, thereby reducing the cost of the ventilator, improving the system reliability of the ventilator, and improving the wearer's comfort in using the ventilator. Since the relatively pure wearer's respiratory action signal is obtained, the ventilator can more closely follow the wearer's respiratory action, and the wearer has a good breathing experience.

Description

Technical Field

[0001] The invention relates to the field of ventilators, and in particular to a method for filtering fan interference from airway signals of ventilators. Background Art

[0002] In order to improve the therapeutic effect of the ventilator and the wearer's breathing comfort, ventilators with autonomous triggering modes have appeared on the market. This air supply mode adjusts the air supply intensity of the ventilator in real time according to the wearer's breathing status. In order to obtain the wearer's breathing status, there are currently many solutions on the market, such as collecting the wearer's respiratory cluster electromyographic signals, analyzing the wearer's chest acceleration signals, collecting PPG (photoplethysmography) signals to analyze respiratory signals, etc. However, the above solutions all require adding sensors outside the ventilator's airway, which increases production costs and reduces system reliability. In addition, the wearer needs to wear these sensors, making the wearing process more cumbersome and the use process more restrictive. Therefore, the most ideal solution is to use only the sensors in the ventilator's airway to obtain the wearer's breathing status.

[0003] However, during the use of the ventilator, the wearer's spontaneous breathing will cause the gas state parameters (such as air pressure, flow rate and other parameters) in the ventilator's airway to change, and the ventilator's air source that continuously changes the air supply intensity according to the wearer's breathing movements will also cause the gas state parameters in the ventilator's airway to change. Therefore, in fact, the signal collected by the sensor in the ventilator's airway is a mixed signal composed of the wearer's spontaneous breathing movement and the ventilator's air supply movement. The mixed signal cannot directly reflect the wearer's breathing state; further, if the mixed signal is directly used to control the ventilator's air supply intensity, and the constantly changing air supply intensity in turn changes the mixed signal, this closed-loop process will mask the airway signal generated by the wearer's spontaneous breathing, making it impossible for the sensor data in the airway to reflect the wearer's breathing state.

[0004] To address this issue, simply calculating the transfer function of the ventilator's airway system using the blower's airflow intensity input versus the airway's gas parameter output will not accurately reflect the system's characteristics. This is because increasing and decreasing the air supply intensity into the airway are different physical processes. Therefore, a simple transfer function based on the blower's airflow intensity input versus the airway's gas parameter output cannot effectively filter out interference signals generated by the blower within the ventilator's airway. Summary of the Invention

[0005] In order to overcome the shortcomings of the prior art, one of the objectives of the present invention is to provide a method for filtering out fan interference from a ventilator airway signal, thereby filtering out the interference caused by the constantly changing output intensity of the airflow control element in the airway, and obtaining a relatively pure wearer's breathing action signal.

[0006] One of the purposes of the present invention is achieved by the following technical solution:

[0007] A method for filtering out fan interference from a ventilator airway signal comprises the following steps:

[0008] Build the ventilator airway system: the signal generator outputs a control signal to enable the airflow control element to control the airflow size in the airway, and the sensor outputs the airflow size signal in the airway;

[0009] Obtain the transfer function of the ventilator airway system: Block the ventilator airway outlet to simulate the wearer holding their breath. The control signal of the signal generator will step. The control signal and the sensor signal will be recorded during the entire step process. The transfer function of the ventilator airway system will be calculated with the control signal as input and the sensor signal as output.

[0010] Collecting signals during the use of the ventilator airway system: When the wearer is using the ventilator, the control signal of the signal generator is collected and recorded as the fifth signal, and the signal of the sensor is collected and recorded as the sixth signal;

[0011] calculating a signal generated by the airflow control element in the airway during the wearer's breathing: separating the fifth signal to generate separate signals, calculating different sensor signals generated by the airflow control element under control of the separate signals using a transfer function of the ventilator airway system, and summing the different sensor signals to obtain a sensor signal generated by the airflow control element in the airway during the wearer's breathing;

[0012] Calculating the human breathing signal after filtering out fan interference during the wearer's breathing process: subtracting the sixth signal of the sensor from the sensor signal generated by the airflow control element in the airway during the wearer's breathing process to obtain the human breathing signal after filtering out fan interference during the wearer's breathing process.

[0013] Furthermore, the steps for obtaining the transfer function of the ventilator airway system are as follows: the control signal of the signal generator jumps from the continuous minimum intensity to the continuous maximum intensity, the control signal of the signal generator during the entire jump process is recorded as the first signal, and the signal of the sensor during the entire jump process is recorded as the second signal; the control signal of the signal generator drops from the continuous maximum intensity to the minimum intensity, the control signal of the signal generator during the entire drop process is recorded as the third signal, and the signal of the sensor during the entire drop process is recorded as the fourth signal; with the first signal as input and the second signal as output, the rising transfer function G of the ventilator airway system is calculated. R ; Using the third signal as input and the fourth signal as output, calculate the descending transfer function G of the ventilator airway system F .

[0014] Furthermore, in the step of obtaining the transfer function of the ventilator airway system, before the control signal of the signal generator jumps, the signal generator outputs a continuous minimum airflow intensity signal to the airflow control element to minimize the airflow intensity in the airway, and maintains this state until the output signal of the sensor stabilizes.

[0015] Furthermore, the signal generated by the airflow control element in the airway during the wearer's breathing is calculated as follows: the fifth signal is separated into a seventh signal that only rises and an eighth signal that only falls; and the rising transfer function G is used. R Calculate the sensor signal ninth signal generated by the airflow control element under the control of the seventh signal; use the descending transfer function G F A tenth signal, a sensor signal generated by the airflow control element under the control of the eighth signal, is calculated; and the ninth signal and the tenth signal are added together to obtain a signal generated by the airflow control element in the airway during the wearer's breathing.

[0016] Furthermore, in the process of calculating the signal generated by the airflow control element in the airway during the wearer's breathing, the principle of separating the fifth signal is that the timing of the fifth signal, the seventh signal and the eighth signal remain consistent.

[0017] Furthermore, the timings of the fifth signal, the seventh signal, and the eighth signal are kept consistent. Specifically, within the rising time period of the fifth signal, the rising amplitude of the seventh signal is the same as the rising amplitude of the fifth signal.

[0018] Furthermore, the timings of the fifth signal, the seventh signal, and the eighth signal are kept consistent. Specifically, within the falling time period of the fifth signal, the falling amplitude of the eighth signal is the same as the falling amplitude of the fifth signal.

[0019] Furthermore, in the step of building a ventilator airway system, the airflow control element is any one of a fan, a proportional valve, and a servo valve.

[0020] Furthermore, in the step of building the ventilator airway system, the sensor is any one of a gauge pressure sensor, a differential pressure sensor, an absolute pressure sensor, and a flow sensor.

[0021] Furthermore, in the step of building a ventilator airway system, the airway is any one of a fan pipeline, a breathing pipeline, a mouth and nose mask, and a full face mask.

[0022] Compared with the existing technology, the method of filtering out fan interference from the ventilator airway signal of the present invention filters out the interference generated in the airway by the constantly changing output intensity of the airflow control element through the steps of obtaining the transfer function of the ventilator airway system, collecting the use process signal of the ventilator airway system, calculating the signal generated by the airflow control element in the airway during the wearer's breathing, and calculating the human breathing signal with the fan interference filtered out during the wearer's breathing, thereby obtaining a relatively pure wearer's breathing action signal; a relatively pure wearer's breathing action signal can be obtained by only using sensors arranged in the ventilator airway, and the wearer does not need to wear additional sensors to monitor the breathing action separately, thereby reducing the cost of the ventilator, improving the system reliability of the ventilator, and improving the wearer's comfort in using the ventilator; since a relatively pure wearer's breathing action signal is obtained, the ventilator can follow the wearer's breathing action more closely, so that the wearer has a better breathing experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A system diagram of a method for filtering out fan interference from a ventilator airway signal according to the present invention;

[0024] Figure 2 Flowchart for obtaining the transfer function of the ventilator airway system;

[0025] Figure 3 Flowchart for filtering out fan interference;

[0026] Figure 4 is a schematic diagram of a first signal;

[0027] Figure 5 is a schematic diagram of the second signal;

[0028] Figure 6 is a schematic diagram of a third signal;

[0029] Figure 7 is a schematic diagram of a fourth signal;

[0030] Figure 8 is a schematic diagram of the fifth signal;

[0031] Figure 9 is a schematic diagram of the seventh signal;

[0032] Figure 10 is a schematic diagram of the eighth signal;

[0033] Figure 11 is a schematic diagram of the sixth signal;

[0034] Figure 12 is a schematic diagram of the ninth signal;

[0035] Figure 13 is a schematic diagram of the tenth signal;

[0036] Figure 14 The sensor signal generated by the airflow control element in the airway during the wearer's breathing;

[0037] Figure 15 Filter out the human breathing signal interfered by the fan during the wearer's breathing process.

[0038] In the figure: 10, airflow control element; 20, airway; 30, wearer; 40, signal generator; 50, sensor. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0040] It should be noted that when a component is referred to as being "fixed to" another component, it may be directly on the other component or there may be another intermediate component through which it is fixed. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be another intermediate component at the same time. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be another intermediate component at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0042] Figure 1 This is a system diagram of the method for filtering out fan interference from a ventilator airway signal of the present invention. The ventilator airway system includes an airflow control element 10, an airway 20, a signal generator 40 and a sensor 50.

[0043] A method for filtering out fan interference from a ventilator airway signal comprises the following steps:

[0044] Build a ventilator airway system: the signal generator 40 outputs a control signal to enable the airflow control element 10 to control the airflow in the airway 20, and the sensor 50 outputs an airflow signal in the airway 20;

[0045] Obtaining the transfer function of the ventilator airway system: Blocking the outlet of the ventilator airway 20 simulates the wearer 30 holding their breath. The control signal of the signal generator 40 generates a step. The control signal and the signal of the sensor 50 are recorded throughout the entire step process. The transfer function of the ventilator airway 20 system is calculated using the control signal as input and the signal of the sensor 50 as output.

[0046] Acquisition of ventilator airway system use process signal: When the wearer 30 is using the ventilator, the control signal of the acquisition signal generator 40 is recorded as the fifth signal (such as Figure 8 As shown), the signal of the acquisition sensor 50 is recorded as the sixth signal (as shown Figure 11 shown);

[0047] calculating a signal generated by the airflow control element 10 in the airway 20 during breathing by the wearer 30: separating the fifth signal to generate separate signals, calculating different sensor 50 signals generated by the airflow control element 10 under control of the separate signals using a transfer function of the ventilator airway 20 system, and summing the different sensor 50 signals to obtain a sensor 50 signal generated by the airflow control element 10 in the airway 20 during breathing by the wearer 30;

[0048] Calculate the human respiratory signal of the wearer 30 after filtering out the fan interference during the breathing process: the sixth signal of the sensor 50 is combined with the sensor signal generated by the airflow control element 10 in the airway 20 during the breathing process of the wearer 30 (such as Figure 14 As shown in the figure), the wearer's breathing process 30 is filtered out of the fan interference of the human body breathing signal (as shown in the figure) Figure 15 shown).

[0049] Please continue reading Figure 2 The specific steps for obtaining the transfer function of the ventilator airway system are as follows: the signal generator 40 outputs a continuous minimum airflow intensity signal to the airflow control element 10 to minimize the airflow intensity in the airway 20 and maintain this state until the output signal of the sensor 50 stabilizes. The control signal of the signal generator 40 jumps from the continuous minimum intensity to the continuous maximum intensity. The control signal of the signal generator 40 during the entire jump process is recorded as the first signal (e.g., Figure 4 As shown), the signal of the sensor 50 during the entire jump process is recorded as the second signal (as shown Figure 5 The control signal of the signal generator 40 is dropped from the maximum intensity to the minimum intensity, and the control signal of the signal generator 40 during the entire drop is recorded as the third signal (as shown); Figure 6 As shown), the signal of the sensor 50 during the entire sudden drop process is recorded as the fourth signal (as shown Figure 7Taking the first signal as input and the second signal as output, the rising transfer function G of the ventilator airway 20 system is calculated. R ; Using the third signal as input and the fourth signal as output, calculate the descending transfer function G of the ventilator airway 20 system F .

[0050] The step of obtaining the transfer function of the ventilator airway system is a preprocessing step and can be repeated multiple times to obtain the transfer function as accurate as possible. R and G F This eliminates the need to repeat the preconditioning steps each time the ventilator is used.

[0051] Please continue reading Figure 3 , Figure 3 Flowchart for filtering out fan interference. In the process of filtering out fan interference, the signal generated by the airflow control element 10 in the airway 20 during the breathing of the wearer 30 is calculated as follows: the fifth signal is separated into only the seventh signal (such as the rising Figure 9 ) and only the eighth signal falling (as shown Figure 10 As shown); using the rising transfer function G R Calculate the ninth signal (e.g., the ninth signal) of the sensor 50 generated by the airflow control element 10 under the control of the seventh signal Figure 12 As shown); using the descending transfer function G F Calculate the tenth signal (e.g., the sensor signal 50 generated by the airflow control element 10 under the control of the eighth signal) Figure 13 The ninth signal and the tenth signal are added to obtain the signal generated by the airflow control element 10 in the airway 20 during the breathing process of the wearer 30 (as shown); Figure 14 (as shown). When calculating the signals generated by the airflow control element 10 within the airway 20 during the wearer's 30 breathing, the principle for separating the fifth signal is that the timing of the fifth, seventh, and eighth signals is consistent. Specifically, the timing consistency of the fifth, seventh, and eighth signals is achieved by: during the rising period of the fifth signal, the rising amplitude of the seventh signal is the same as the rising amplitude of the fifth signal. During the falling period of the fifth signal, the falling amplitude of the eighth signal is the same as the falling amplitude of the fifth signal.

[0052] During the steps of constructing the ventilator airway system, the airflow control element 10 can be any one of a blower, a proportional valve, or a servo valve. The sensor 50 can be any one of a gauge pressure sensor, a differential pressure sensor, an absolute pressure sensor, or a flow sensor. The airway 20 can be any one of a blower line, a breathing line, an oronasal mask, or a full-face mask.

[0053] The method of filtering out fan interference from the ventilator airway signal of the present invention can filter out the interference caused by the constantly changing output intensity of the airflow control element 10 in the airway, and obtain a relatively pure breathing action signal of the wearer 30; a relatively pure breathing action signal of the wearer 30 can be obtained by only using the sensor 50 arranged in the ventilator airway 20, and the wearer 30 does not need to wear an additional sensor 50 to monitor the breathing action separately, which reduces the cost of the ventilator, improves the system reliability of the ventilator, and improves the comfort of the wearer 30 when using the ventilator; since a relatively pure breathing action signal of the wearer 30 is obtained, the ventilator can follow the breathing action of the wearer 30 more closely, so that the wearer 30 has a better breathing experience.

[0054] The above embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patented invention. It should be noted that those skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention. These variations and improvements are equivalent modifications and improvements to the above embodiments based on the essential technology of the present invention and fall within the scope of protection of the present invention.

Claims

1. A method for filtering out fan interference from a ventilator airway signal, characterized in that: The following steps are involved: Build the ventilator airway system: the signal generator outputs a control signal to enable the airflow control element to control the airflow size in the airway, and the sensor outputs the airflow size signal in the airway; Obtain the transfer function of the ventilator airway system: block the ventilator airway outlet to simulate the wearer holding their breath, the control signal of the signal generator jumps from the continuous minimum intensity to the continuous maximum intensity, the control signal of the signal generator during the entire jump process is recorded as the first signal, and the signal of the sensor during the entire jump process is recorded as the second signal; the control signal of the signal generator drops from the continuous maximum intensity to the minimum intensity, the control signal of the signal generator during the entire drop process is recorded as the third signal, and the signal of the sensor during the entire drop process is recorded as the fourth signal; use the first signal as input and the second signal as output to calculate the rising transfer function of the ventilator airway system ; Using the third signal as input and the fourth signal as output, calculate the descending transfer function of the ventilator airway system ; Collecting signals during the use of the ventilator airway system: When the wearer is using the ventilator, the control signal of the signal generator is collected and recorded as the fifth signal, and the signal of the sensor is collected and recorded as the sixth signal; calculating a signal generated by the airflow control element in the airway during the wearer's breathing: separating the fifth signal to generate separate signals, calculating different sensor signals generated by the airflow control element under control of the separate signals using a transfer function of the ventilator airway system, and summing the different sensor signals to obtain a sensor signal generated by the airflow control element in the airway during the wearer's breathing; Calculating the human breathing signal after filtering out fan interference during the wearer's breathing process: subtracting the sixth signal of the sensor from the sensor signal generated by the airflow control element in the airway during the wearer's breathing process to obtain the human breathing signal after filtering out fan interference during the wearer's breathing process.

2. The method for filtering out fan interference from a ventilator airway signal according to claim 1, characterized in that: In the step of obtaining the transfer function of the ventilator airway system, before the control signal of the signal generator generates a step, the signal generator outputs a continuous minimum airflow intensity signal to the airflow control element to minimize the airflow intensity in the airway, and maintains this state until the output signal of the sensor stabilizes.

3. The method for filtering out fan interference from a ventilator airway signal according to claim 1, characterized in that: The calculation of the signal generated by the airflow control element in the airway during the wearer's breathing is specifically as follows: the fifth signal is separated into the seventh signal that only rises and the eighth signal that only falls; using the rising transfer function Calculate the sensor signal ninth signal generated by the airflow control element under the control of the seventh signal; use the descending transfer function A tenth signal, a sensor signal generated by the airflow control element under the control of the eighth signal, is calculated; and the ninth signal and the tenth signal are added together to obtain a signal generated by the airflow control element in the airway during the wearer's breathing.

4. The method for filtering out fan interference from a ventilator airway signal according to claim 3, characterized in that: In the process of calculating the signal generated by the airflow control element in the airway during the wearer's breathing, the principle of separating the fifth signal is that the time of the fifth signal, the seventh signal and the eighth signal remain consistent.

5. The method for filtering out fan interference from ventilator airway signals according to claim 4, characterized in that: The timings of the fifth signal, the seventh signal, and the eighth signal are kept consistent. Specifically, during the rising time period of the fifth signal, the rising amplitude of the seventh signal is the same as the rising amplitude of the fifth signal.

6. The method for filtering out fan interference from ventilator airway signals according to claim 4, characterized in that: The timings of the fifth signal, the seventh signal, and the eighth signal are kept consistent. Specifically, within the falling time period of the fifth signal, the falling amplitude of the eighth signal is the same as the falling amplitude of the fifth signal.

7. The method for filtering out fan interference from ventilator airway signals according to claim 1, characterized in that: In the steps of building a ventilator airway system, the airflow control element is any one of a fan, a proportional valve, and a servo valve.

8. The method for filtering out fan interference from ventilator airway signals according to claim 1, characterized in that: In the steps of building a ventilator airway system, the sensor is any one of a gauge pressure sensor, a differential pressure sensor, an absolute pressure sensor, and a flow sensor.

9. The method for filtering out fan interference from ventilator airway signals according to claim 1, characterized in that: In the steps of building a ventilator airway system, the airway can be any one of a fan pipeline, a breathing pipeline, a mouth and nose mask, and a full-face mask.

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