Respiratory signal reliability judgment method and device and storage medium
By verifying signals from physiological signal sources different from respiratory signal sources, calculating signal quality and judging the reliability of respiratory signals, the problem of respiratory signal reliability under different respiratory modes is solved, the triggering of false alarms is reduced, and the respiratory monitoring is improved accuracy.
Patent Information
- Application Number
- CN202310955932.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-08-01
- Publication Date
- 2025-02-14
AI Technical Summary
The amplitudes of expansion and contraction of the chest and abdomen under different breathing modes lead to the amplitude of impedance changes, affecting the reliability of the respiratory signal, and may trigger false alarms of apnea.
By verifying the signals of physiological signal sources different from the respiratory signal source, the first and second signal quality is calculated, the reliability of the first respiratory signal is judged, and the triggering of false alarms is reduced.
Accurate and reliable judgment of respiratory signals is achieved, the triggering of false apnea alarms is reduced, and the accuracy of respiratory monitoring is improved.
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Figure CN119423735A_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present application relate to the field of medical equipment technology, and in particular to a method, device and storage medium for determining the reliability of a respiratory signal. Background Art
[0002] Respiratory monitoring equipment is a device that monitors the respiratory status of the monitored object.
[0003] Usually, impedance-based respiratory rate detection is used for monitoring. This method is based on the principle that the human body is conductive. The measurement area is equivalent to a resistor. The impedance of the measurement area changes with the respiratory movement, so the respiratory state is monitored by measuring the impedance change. For example, electrodes are attached to both sides of the patient's chest and a high-frequency constant current source is applied. When the patient breathes, the chest expands and contracts, and the resistance between the electrodes changes accordingly. The respiratory signal waveform is obtained by detecting the impedance change, and the respiratory rate and other information are calculated based on the respiratory signal waveform, so as to monitor whether the patient's respiratory state is normal.
[0004] It should be noted that the above introduction to the technical background is only intended to provide a clear and complete description of the technical solution of the present application and to facilitate understanding by those skilled in the art. Summary of the invention
[0005] Breathing modes are divided into chest breathing, abdominal breathing, and chest-abdominal breathing. The chest and abdomen expand and contract at different amplitudes under different breathing modes, and the amplitude of impedance change is also affected. Therefore, the size of the electrode signal will be affected by the breathing mode, which will affect the monitoring of the respiratory state. For example, assuming that the patient's breathing state is normal and the patient's breathing mode is abdominal breathing, but the respiratory signal collected by the chest electrode is used for respiratory monitoring, and because the chest impedance changes very little under abdominal breathing, the collected respiratory signal is weak, which may trigger a false alarm of apnea.
[0006] In response to at least one of the above technical problems, embodiments of the present application provide a method, device and storage medium for determining the reliability of a respiratory signal.
[0007] According to a first aspect of an embodiment of the present application, a method for determining the reliability of a breathing signal is provided, the method comprising:
[0008] Calculating a first signal quality according to a first breathing signal from a first signal source, wherein the first breathing signal is a physiological signal representing a breathing state of a user;
[0009] calculating a second signal quality based on a second signal from at least one second signal source different from the first signal source, the second signal being a physiological signal different from the first respiratory signal, and
[0010] The reliability of the first breathing signal is determined according to the second signal quality and the first signal quality.
[0011] According to a second aspect of an embodiment of the present application, a device for determining the reliability of a breathing signal is provided, the device comprising:
[0012] A processor, which executes the steps of the method as described in the embodiment of the first aspect.
[0013] According to a third aspect of the embodiments of the present application, a non-transitory computer-readable storage medium is provided, which is used to store a computer program. When the computer program is executed by a computer, the computer executes the method described in the embodiments of the first aspect.
[0014] One of the beneficial effects of the embodiments of the present application is that the reliability of the respiratory signal of the respiratory signal source is verified by the signal of the physiological signal source different from the respiratory signal source, thereby achieving accurate monitoring and reducing the triggering of false apnea alarms.
[0015] With reference to the following description and accompanying drawings, the specific implementation of the embodiment of the present application is disclosed in detail, indicating the way in which the principle of the embodiment of the present application can be adopted. It should be understood that the implementation of the present application is not limited in scope. Within the scope of the spirit and clauses of the attached claims, the implementation of the present application includes many changes, modifications and equivalents. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The included drawings are used to provide a further understanding of the embodiments of the present application, which constitute a part of the specification, are used to illustrate the implementation methods of the present application, and together with the text description, explain the principles of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other implementation methods can be obtained based on these drawings without creative work. In the drawings:
[0017] Figure 1 It is a schematic diagram of an implementation of a method for determining the reliability of a breathing signal according to an embodiment of the present application.
[0018] Figure 2 2 is a schematic diagram of another implementation of the method for determining the reliability of a breathing signal according to an embodiment of the present application.
[0019] Figure 3 is a schematic diagram of a pulse wave signal according to an embodiment of the present application.
[0020] Figure 4 Yes Figure 3 A schematic diagram of the pulse wave signal after signal processing is shown.
[0021] Figure 5 is based on Figure 3 A schematic diagram of a second respiratory signal obtained from a pulse wave signal is shown.
[0022] Figure 6 is a schematic diagram of an electrocardiogram signal according to an embodiment of the present application.
[0023] Figure 7 is from Figure 6 The QRS complex extracted from the ECG signal is shown.
[0024] Figure 8 is based on Figure 6 A schematic diagram of a second respiratory signal obtained from an electrocardiogram signal is shown.
[0025] Fig. 9 4 is a flow chart of a method for determining the reliability of a respiratory signal according to an embodiment of the present application.
[0026] Fig.10 It is a waveform diagram for verifying the method of the embodiment of the present application.
[0027] Fig.11 It is another waveform diagram for verifying the method of the embodiment of the present application.
[0028] Fig.12 It is another waveform diagram for verifying the method of the embodiment of the present application.
[0029] Fig.13 is a schematic diagram of a breathing signal reliability judgment device according to an embodiment of the present application. DETAILED DESCRIPTION
[0030] With reference to the accompanying drawings, the foregoing and other features of the embodiments of the present application will become apparent through the following description. In the description and the accompanying drawings, specific embodiments of the present application are specifically disclosed, which show some embodiments in which the principles of the embodiments of the present application can be adopted. It should be understood that the present application is not limited to the described embodiments. On the contrary, the embodiments of the present application include all modifications, variations and equivalents that fall within the scope of the attached claims.
[0031] In the embodiments of the present application, the terms "first", "second", etc. are used to distinguish different elements in terms of title, but do not indicate the spatial arrangement or temporal order of these elements, etc., and these elements should not be limited by these terms. The term "and / or" includes any one and all combinations of one or more of the associated listed terms. The terms "comprising", "including", "having", etc. refer to the presence of the stated features, elements, components or components, but do not exclude the presence or addition of one or more other features, elements, components or components.
[0032] In the embodiments of the present application, the singular forms "a", "the", etc. include plural forms and should be broadly understood as "a kind" or "a type" rather than being limited to the meaning of "one"; in addition, the term "said" should be understood to include both singular and plural forms, unless the context clearly indicates otherwise. In addition, the term "according to" should be understood as "at least in part according to...", and the term "based on" should be understood as "at least in part based on...", unless the context clearly indicates otherwise.
[0033] Features described and / or shown for one embodiment may be used in one or more other embodiments in the same or similar manner, combined with features in other embodiments, or replace features in other embodiments. The term "includes / comprising" when used herein refers to the presence of a feature, an entirety, a step, or a component, but does not exclude the presence or addition of one or more other features, entireties, steps, or components.
[0034] An embodiment of the present application provides a method for determining the reliability of a breathing signal. Figure 1 It is a schematic diagram of an implementation of a method for determining the reliability of a breathing signal according to an embodiment of the present application.
[0035] like Figure 1 As shown, the method 100 includes:
[0036] 101: Calculating a first signal quality according to a first breathing signal from a first signal source, where the first breathing signal is a physiological signal representing a user's breathing state;
[0037] 102: Calculating a second signal quality according to a second signal from at least one second signal source different from the first signal source, wherein the second signal is a physiological signal different from the first respiratory signal, and
[0038] 103: Determine the reliability of the first breathing signal according to the second signal quality and the first signal quality.
[0039] Thus, the reliability of the respiratory signal of the respiratory signal source is judged by the signal of the physiological signal source different from the respiratory signal source, thereby reducing the triggering of false apnea alarms.
[0040] In operation 101, the first signal source is, for example, a respiratory monitoring device, and the first respiratory signal is, for example, a respiratory signal acquired by an abdominal electrode or a chest electrode, and the first respiratory signal is sometimes referred to as an "impedance RESP waveform". In addition, the embodiment of the present application does not limit the first signal quality of the first respiratory signal, for example, the first signal quality is the amplitude and / or respiratory rate of the first respiratory signal.
[0041] In operation 102, the second signal source is a monitoring device different from the respiratory monitoring device, such as an electrocardiogram monitoring device, etc. In addition, the second signal is, for example, a physiological signal related to the user's respiratory state, such as at least one of a pulse wave signal and an electrocardiogram signal.
[0042] The inventors have found that during the breathing process, the vagus nerve, sympathetic nerve and other pressure sensor systems near the aortic arch are affected. The nervous system then adjusts the intervals of heart contraction during breathing to ensure stable blood pressure. In addition, the lungs squeeze the heart, affecting the heart's ejection, the pulse wave slope (ejection velocity) and the pulse wave amplitude (ejection intensity). Both thoracic breathing and abdominal breathing have this effect. Therefore, the electrocardiogram (ECG) wave and the pulse wave contain information reflecting the respiratory state. For example, by detecting the RR interval of the ECG wave, detecting the envelope of the pulse wave, or interpolating, a respiratory waveform (i.e., RESP waveform) can be obtained.
[0043] Therefore, other physiological signals related to the respiratory state can be used to verify the reliability of the respiratory signal, thereby reducing the occurrence of false apnea alarms.
[0044] The relevant contents of the second signal will be described in detail below.
[0045] Figure 2 2 is a schematic diagram of another implementation of the method for determining the reliability of a breathing signal according to an embodiment of the present application.
[0046] like Figure 2 As shown, the method 200 includes:
[0047] 201: Calculate a second breathing signal according to a signal related to the user's breathing state in the second signal;
[0048] 202: When it is determined that the first breathing signal is unreliable, switch the first breathing signal to the second breathing signal.
[0049] In operation 201, the second breathing signal is a signal extracted from the second signal. For example, since the user's breathing state will affect changes in physiological parameters such as heart rate and pulse, the ECG signal and the pulse wave signal contain information about the breathing state, and a signal related to the breathing state can be extracted by performing signal processing on the ECG signal or the pulse wave signal.
[0050] The following describes the method of extracting the second respiratory signal from the second signal by taking the pulse wave signal and the electrocardiogram wave signal as examples, but the embodiment of the present application is not limited thereto, and the second signal may also be other physiological signals affected by respiratory motion.
[0051] In at least one embodiment, the second signal is a pulse wave signal. In addition, the embodiment of the present application does not limit the acquisition method of the pulse wave signal, for example, it can be a photoelectric pulse waveform obtained by non-invasive blood pressure detection, or it can be a pulse waveform obtained by invasive blood pressure detection.
[0052] Figure 3 is a schematic diagram of a pulse wave signal according to an embodiment of the present application, wherein (a) is an original pulse wave signal, and (b) is a filtered pulse wave signal after high-pass filtering the original pulse wave signal; Figure 4 Yes Figure 3 A schematic diagram of a pulse wave signal after signal processing shown in FIG. 1 , wherein (a) is a slope waveform and (b) is an amplitude waveform; Figure 5 is based on Figure 3 A schematic diagram of a second respiratory signal obtained from a pulse wave signal is shown.
[0053] In at least one embodiment, the pulse wave signal is subjected to high-pass filtering to obtain a filtered pulse wave signal.
[0054] like Figure 3 As shown, the original pulse wave signal (such as Figure 3 (a) contains a lot of low-frequency drift interference and high-frequency noise, and the respiratory signal is a low-frequency signal. Therefore, high-pass filtering of the pulse wave signal can remove low-frequency interference and improve the accuracy of extracting the respiratory signal (as shown in Figure 3 In addition, the pulse wave signal can also be curve fitted to remove low-frequency interference.
[0055] In at least one embodiment, a slope envelope and / or an amplitude envelope of the filtered pulse wave signal is extracted.
[0056] For example, Figure 3 The filtered pulse wave signal shown in (b) is differentiated to obtain the slope curve of the signal, and the slope envelope is extracted according to the slope curve, as shown in FIG. Figure 4 (a) of Figure 3 The amplitude envelope of the filtered pulse wave signal shown in (b) is extracted, as Figure 4 as shown in (b).
[0057] The embodiments of the present application do not limit the implementation method of extracting the slope envelope or the amplitude envelope, and the specific implementation method can refer to the relevant technology.
[0058] In addition, when extracting the waveform of the respiratory state based on the pulse wave signal, it is more convenient and quick to extract the amplitude envelope, that is, the peak point and the trough point of the pulse wave are usually separated by half a pulse wave cycle, and the peak and the trough of the pulse wave can be detected to record the changes in the respiratory waveform. However, the inventor found that because the peak point and the trough point of the pulse wave are far apart, they are easily affected by low-frequency interference. By detecting the envelope of the pulse wave slope, it can not only reflect the changes in the ejection intensity caused by the lungs squeezing the heart during breathing, but also reflect the changes in the ejection velocity; and the peak point and the trough point of the pulse wave slope are close to each other, and the anti-drying property is stronger, which can more accurately reflect the fluctuation of the heart ejection with the respiratory cycle, so that the respiratory waveform can be extracted more accurately.
[0059] In at least one embodiment, the second breathing signal is obtained according to the slope envelope and / or the amplitude envelope.
[0060] For example, the slope envelope and the amplitude envelope are weighted, the peak and valley points are interpolated, and resampled to obtain a second respiratory signal (sometimes also called a "pulse RESP waveform"), for example, Figure 5 A second breathing signal 502 is shown.
[0061] In at least one embodiment, in operation 102, the second signal quality can be calculated based on at least one of the amplitude of the second breathing signal, the proportion of signal energy in the first frequency range in the second breathing signal to the total energy, the proportion of the second frequency range centered on the main frequency in the second breathing signal to the total frequency range, and the statistics of the pulse interval of the pulse wave signal.
[0062] The amplitude of the second respiration signal is, for example, an average value of the amplitude of the second respiration signal.
[0063] The first frequency range is, for example, a range of 0.15 Hz to 1 / 3 of the heart rate, where the heart rate is, for example, the heart rate of the monitored object (e.g., a patient), or it may be a heart rate obtained through statistics, for example, a normal heart rate range or a median heart rate or an average heart rate obtained through statistics for men / women / children / youth / elderly people, etc. The embodiments of the present application are not limited to this.
[0064] The second frequency range is, for example, a predetermined range on both sides of the center frequency obtained after spectrum transformation of the second respiratory signal, and the predetermined range is, for example, 1 / 4 of the heart rate. The embodiment of the present application does not limit the second frequency range.
[0065] The statistic of the pulse interval of the pulse wave signal is, for example, the average difference of the pulse interval, the mean square error of the pulse interval, etc., which is not limited in the embodiment of the present application.
[0066] In addition, in some embodiments, the second signal quality can be obtained by weighted calculation of the amplitude of the second breathing signal, the proportion of the signal energy in the first frequency range of the second breathing signal to the total energy, the proportion of the second frequency range centered on the main frequency in the second breathing signal to the total frequency range, the statistics of the pulse interval of the pulse wave signal, etc.
[0067] In addition, the first signal quality may also be calculated based on the amplitude, rate, and ratio of frequencies near the main frequency to the total frequency range of the first respiratory signal, which is not limited in this embodiment of the present application.
[0068] In operation 103, whether the first breathing signal is reliable is determined based on the first signal quality and the second signal quality. For example, the first signal quality is compared with a first threshold; the second signal quality is compared with a second threshold; when the first signal quality is lower than the first threshold and the second signal quality is higher than the second threshold, it is determined that the first breathing signal is unreliable. The embodiment of the present application does not limit the values of the first threshold and the second threshold, and they can be set according to actual needs.
[0069] Therefore, by measuring the stability and reliability of the signal through the signal quality and judging the reliability of the first respiratory signal through a more stable and reliable signal, the generation of false apnea alarms caused by the first respiratory signal can be reduced.
[0070] In addition, in operation 202, when the first breathing signal is unreliable, the second breathing signal is used to monitor the breathing state of the subject. For example, the second breathing signal is used to calculate the breathing rate, or the second breathing signal is used to monitor whether there is apnea. When an abnormal breathing rate or apnea is detected, an alarm is issued.
[0071] In addition, when the quality of the first signal is above the first threshold, the first respiratory signal can be considered reliable and the first respiratory signal can continue to be used for detection. In addition, when the first respiratory signal is reliable, it is further determined whether there is apnea, and if apnea occurs, an apnea alarm is issued.
[0072] In addition, if Figure 2 As shown, the method 200 may further include:
[0073] 203: When it is determined that the first breathing signal is unreliable, output information indicating that the input wire corresponding to the first breathing signal is not compatible with the state of the user.
[0074] For example, suppose the user (e.g., a patient) is breathing chest-wise, but the operator (e.g., a nurse) connects the signal from the monitor's abdominal electrode to the input port of the respiratory monitor. Since the signal from the abdominal electrode is weak, an apnea alarm may be triggered. However, this alarm alone cannot confirm whether the wrong input wire was selected or the patient's breathing is weak.
[0075] Through the embodiments of the present application, it can be determined that the signal of the abdominal electrode is unreliable, and a prompt message indicating that the wrong wire is connected can be output. After seeing the prompt message, the operator can understand that the patient may be chest breathing and then reinsert the correct input wire.
[0076] For another example, assuming that the lead electrode has poor contact, resulting in a weak detection signal, triggering an apnea alarm. Through the embodiment of the present application, it can be determined that the signal corresponding to the lead electrode is unreliable, and a prompt message can be output to remind the operator to carefully check whether there is a lead electrode contact situation.
[0077] In at least one embodiment, the second signal is an electrocardiogram signal. In addition, the electrocardiogram signal of the embodiment of the present application can be collected, for example, by a single lead method or by a multi-lead method, and the embodiment of the present application does not limit the acquisition method. Thus, the source signal of the RESP signal can be obtained from the limbs or a single electrocardiogram lead.
[0078] Figure 6 is a schematic diagram of an electrocardiogram signal according to an embodiment of the present application, Figure 7 is from Figure 6 The QRS wave extracted from the ECG signal is shown. Figure 8 is based on Figure 6 A schematic diagram of a second respiratory signal obtained from an electrocardiogram signal is shown.
[0079] In at least one embodiment, the RR interval and the QT interval of the electrocardiogram signal are extracted.
[0080] The RR interval refers to the interval between R waves on the electrocardiogram. Usually, each large grid on the electrocardiogram represents 0.2 seconds, and a normal RR interval occupies 3 to 5 large grids, that is, 0.6 to 1.0 seconds, representing the duration of one cardiac cycle. The number of RR intervals that appear in one minute is the heart rate, and the RR interval can also be calculated by the heart rate. The calculation method is 60 divided by the heart rate. The normal heart rate is 60 to 100 beats per minute. For example, Figure 6 As shown, the RR interval is, for example, 587ms, 576ms, 518ms, etc.
[0081] The QT interval refers to the distance from the start of the QRS complex to the end of the T wave, representing the time required for the entire process of ventricular depolarization and repolarization. The length of the QT interval is closely related to the speed of the heart rate. The faster the heart rate, the shorter the QT interval, and vice versa. The normal range of heart rate is 60-100 beats / minute, and the corresponding normal range of the QT interval is 0.32-0.44 seconds. For example, Figure 7 As shown, the QT interval is, for example, 178 ms, 190 ms, 187 ms, etc.
[0082] For example, all RR intervals and QT intervals within a predetermined time window can be extracted from the electrocardiogram signal within the time window, and the corresponding waveform of the respiratory signal can be obtained by performing signal processing based on the RR waveform corresponding to the RR interval and the QT waveform corresponding to the QT interval. The embodiments of the present application do not limit the implementation method of extracting the RR interval and the QT interval, and reference can be made to related technologies.
[0083] In at least one embodiment, the second respiratory signal is obtained according to the RR interval and the QT interval.
[0084] For example, the RR interval and the QT interval are weighted, interpolated, and resampled to obtain the waveform of the second respiratory signal (sometimes also referred to as an "ECG-RESP waveform"), for example, Figure 8 A second breathing signal 802 is shown.
[0085] In at least one embodiment, in operation 102, the second signal quality can be calculated based on at least one of whether arrhythmia exists, the amplitude of the second respiratory signal, the signal-to-noise ratio of the electrocardiogram signal, the signal proportion of a third frequency range centered on the main frequency in the second respiratory signal, and the statistics of the RR interval.
[0086] For example, whether arrhythmia exists can be determined based on the second signal. For example, whether arrhythmia exists can be determined based on the RR interval and / or the QT interval. The present application embodiment does not limit the specific determination method, and reference can be made to related technologies.
[0087] The amplitude of the second respiration signal is, for example, an average value of the amplitude of the second respiration signal.
[0088] The signal-to-noise ratio of the electrocardiogram signal may be, for example, the signal-to-noise ratio of the R wave in the electrocardiogram signal.
[0089] The third frequency range is, for example, a predetermined range on both sides of the center frequency obtained after spectrum transformation of the second respiratory signal, and the predetermined range is, for example, 1 / 4 of the heart rate. The third frequency range is not limited in the embodiment of the present application.
[0090] The statistic of the RR interval is, for example, the mean difference of the RR interval, the mean square error of the RR interval, etc., which is not limited in the embodiment of the present application.
[0091] In addition, the method of the embodiment of the present application may also include calculating the respiratory rate according to the first respiratory signal and / or the second respiratory signal. Figure 5 shows a first breathing signal 501, Figure 8 A first respiratory signal 801 is shown, and the first respiratory signal 501 or the first respiratory signal 801 is, for example, an impedance RESP waveform. The respiratory rate (RESP rate) can be calculated only according to the first respiratory signal 501 or the first respiratory signal 801, or only according to the second respiratory signal 502 or the second respiratory signal 802. The respiratory rate can also be calculated according to the first respiratory signal 501 / the first respiratory signal 801 and the second respiratory signal 502 / the second respiratory signal 802. The implementation method of calculating the respiratory rate can refer to the relevant technology, and the embodiment of the present application is not limited to this. In addition, after the respiratory rate is calculated, the display device can be controlled to display the respiratory rate.
[0092] The method of judging whether the breathing signal is reliable by the signal quality of the electrocardiogram signal is similar to the method of judging whether the breathing signal is reliable by the signal quality of the pulse wave signal, and will not be described in detail here.
[0093] In addition, the method of the embodiment of the present application may also include, when it is determined that the first breathing signal is unreliable, monitoring the respiratory state according to the second breathing signals corresponding to multiple second signal sources, for example, weighted calculation of the respiratory rates corresponding to the multiple second breathing signals as monitoring parameters.
[0094] Fig. 9 is a flow chart of a method for determining the reliability of a respiratory signal according to an embodiment of the present application. Fig. 9 It should be noted that the following description is intended to make the implementation of the embodiment of the present application clearer and should not be interpreted as limiting the embodiment of the present application.
[0095] like Fig. 9 As shown, the breathing signal reliability determination method 900 includes:
[0096] 901: Obtain impedance RESP waveform;
[0097] 902: performing signal processing on the impedance RESP waveform, for example, performing digital signal processing;
[0098] 903: Calculate the corresponding respiratory rate -1 according to the impedance RESP waveform after signal processing;
[0099] 904: Obtaining a pulse waveform;
[0100] 905: performing signal processing on the pulse waveform, for example, performing digital signal processing;
[0101] 906: extracting a pulse wave envelope from the pulse waveform after signal processing, for example, extracting an amplitude envelope;
[0102] 907: extracting a slope envelope from the pulse waveform after signal processing;
[0103] 908: Obtaining a pulse RESP waveform corresponding to the pulse waveform according to the amplitude envelope and / or the slope envelope;
[0104] 909: Calculate the corresponding respiratory rate -2 according to the pulse RESP waveform;
[0105] 910: Calculate the quality of the pulse RESP waveform;
[0106] 911: Obtain ECG waveform;
[0107] 912: Perform signal processing on the ECG waveform, for example, perform digital signal processing;
[0108] 913: extracting the RR interval and QT interval from the ECG waveform after signal processing;
[0109] 914: Obtaining an ECG-RESP waveform corresponding to the ECG waveform according to the RR interval and the QT interval, for example, performing signal processing such as weighting, interpolation, and resampling on the extracted RR signal corresponding to the RR interval and the QT signal corresponding to the QT interval to obtain the ECG-RESP waveform;
[0110] 915: Calculate the corresponding respiratory rate -3 according to the ECG-RESP waveform;
[0111] 916: Calculate the quality of the ECG-RESP waveform;
[0112] 917: Determine whether the amplitude of the respiratory rate-1 and impedance RESP waveforms is low and the quality of the pulse RESP waveform or the ECG-RESP waveform is high, and if yes, proceed to operation 918, and if no, proceed to operation 919;
[0113] 918: Switch the monitoring source of the respiratory state (e.g., respiratory rate) and notify relevant personnel that the lead for impedance RESP monitoring needs to be replaced;
[0114] 919: Continue to monitor the patient's respiratory status using impedance RESP.
[0115] Thereby, the RESP monitoring sources can be increased and the reliability of RESP detection can be improved.
[0116] In addition, in operation 918, the source signal of the RESP signal may be switched from the impedance RESP waveform to the pulse RESP waveform, or the source signal indicating the respiration rate may be switched from respiration rate-1 to respiration rate-2.
[0117] In addition, the impedance RESP waveform, the pulse RESP waveform and the ECG waveform can verify each other, that is, if the respiratory rate of one of the waveforms is low, the respiratory rates of the other two waveforms can be checked, and if the respiratory waveforms and respiratory rates of the other two waveforms are normal, then the apnea alarm can be ignored, and the input signal for monitoring the respiratory state can be switched to at least one of the two waveforms. In this way, it is possible to automatically find the most stable source from the electrocardiogram, pulse wave, and impedance RESP waveform as the RESP source.
[0118] In addition, the inventors verified the method of the embodiment of the present application using a public physiological signal database. Figures 10 to 12 It is a waveform diagram for verifying the method of the embodiment of the present application.
[0119] For the "The Beth Israel Deconess Medical Centre (BIDMC) PPG and Respiration" dataset, which contains ppg pulse waveforms and impedance RESP waveforms, after analyzing the RESP waveform from the pulse wave, for the 15th, 21st, and 53rd signals, sometimes the impedance RESP waveform is weak and the RESP rate cannot be obtained from the impedance RESP wave, but the pulse RESP waveform is good and the RESP rate can be obtained from the pulse RESP wave. For example, Fig.10 As shown, signal 1001 is an impedance RESP waveform, and signal 1002 is a pulse RESP waveform. During the second half of the signal, the impedance RESP wave is weak, while the pulse RESP waveform extracted from the pulse waveform is still good. This shows that the pulse RESP waveform extracted from the pulse wave signal has higher stability.
[0120] For the MIT-BIH ECG database, the sampling rate is 360 Hz. Fig.12 As shown, Fig.12 This is a schematic diagram of RR interval analysis of an ECG signal. Fig.13 As shown, Fig.13 is the ECG-RESP waveform extracted from the ECG signal.
[0121] It can be seen through verification that the method of the embodiment of the present application can reliably obtain a stable RESP source.
[0122] Furthermore, through the method of the embodiment of the present application, the RESP source is increased without adding new accessories or hardware. Furthermore, if the user does not connect the electrocardiogram wire, the RESP rate can also be obtained from the photoelectric blood oxygen pulse wave, which simplifies the operation of respiratory rate monitoring and enables medical staff to grasp the patient's physiological state more conveniently and quickly.
[0123] The present application also provides a device for determining the reliability of a respiratory signal. Fig.13 is a schematic diagram of a breathing signal reliability judgment device according to an embodiment of the present application.
[0124] like Fig.13 As shown, the breathing signal reliability determination device 1300 includes a processor 1301, and the processor 1301 executes the steps of the breathing signal reliability determination method described in the above embodiment.
[0125] In at least one embodiment, Fig.13 As shown, the breathing signal reliability judgment device 1300 may further include a first signal source 1302 and a second signal source 1303 .
[0126] The first signal source 1302 outputs the first breathing signal described in the above embodiment according to the first input signal. The first signal source 1302 is, for example, a breathing monitoring device.
[0127] The second signal source 1303 outputs the second signal described in the above embodiment according to the second input signal. The number of the second signal source 1303 can be one or more, for example, Fig.13 As shown, it includes a second signal source 1303-1 and a second signal source 1303-2. The second signal source 1303-1 is, for example, an electrocardiogram monitoring device, and the second signal source 1303-2 is, for example, a pulse oxygen saturation monitoring device.
[0128] In at least one embodiment, the processor 1301 may be a processing device that is relatively independent of the first signal source 1302 and the second signal source 1303. For example, the processor 1301 may be a central processor of the respiratory signal reliability judgment device 1300. The signals acquired by each signal source are sent to the processor 1301, and the processing of each step of the method of the aforementioned embodiment is performed in the processor 1301. The processor 1301 may also be a processing unit configured in the first signal source 1302 and / or the second signal source 1303. For example, each signal source processes its own signal to obtain a respiratory waveform, and then inputs the obtained respiratory waveform into a processing unit of a certain signal source for subsequent processing. Alternatively, the obtained respiratory waveform may also be input into the central processor of the respiratory signal reliability judgment device 1300 for subsequent processing. The embodiment of the present application does not limit this.
[0129] In addition, the respiratory signal reliability determination device 1300 may also include other components, such as a display device. In addition, the respiratory signal reliability determination device 1300 may also form a medical system with other devices such as a display device, for example, an electrocardiogram monitor. This embodiment of the present application does not limit this.
[0130] An embodiment of the present application also provides a computer-readable program, wherein when the program is executed, the program enables the computer to execute the breathing signal reliability judgment method described in the above embodiment in a breathing signal reliability judgment device.
[0131] The embodiment of the present application also provides a non-transitory computer-readable storage medium, which is used to store a computer program. When the computer program is executed by a computer, the computer executes the method for determining the reliability of a respiratory signal described in the above embodiment.
[0132] The above embodiments are merely exemplary of the embodiments of the present application, but the present application is not limited thereto, and appropriate modifications may be made based on the above embodiments. For example, the above embodiments may be used alone, or one or more of the above embodiments may be combined.
[0133] The present application is described above in conjunction with specific implementation methods, but it should be clear to those skilled in the art that these descriptions are exemplary and are not intended to limit the scope of protection of the present application. Those skilled in the art can make various modifications and variations to the present application based on the spirit and principles of the present application, and these modifications and variations are also within the scope of the present application.
[0134] The preferred embodiments of the present application are described above with reference to the accompanying drawings. Many features and advantages of these embodiments are clear from this detailed description, and therefore the appended claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. In addition, since many modifications and variations are easily conceivable to those skilled in the art, the embodiments of the present application are not intended to be limited to the precise structures and operations illustrated and described, but all suitable modifications, variations, and equivalents that fall within their scope may be covered.
Claims
1. A method for determining the reliability of a respiratory signal, characterized in that: The method comprises: Calculating a first signal quality according to a first breathing signal from a first signal source, wherein the first breathing signal is a physiological signal representing a breathing state of a user; calculating a second signal quality based on a second signal from at least one second signal source different from the first signal source, the second signal being a physiological signal different from the first respiratory signal, and The reliability of the first breathing signal is determined according to the second signal quality and the first signal quality.
2. The method according to claim 1, characterized in that: The second signal is a physiological signal related to the user's breathing state.
3. The method according to claim 2, characterized in that The method further comprises: Calculating a second breathing signal according to a signal related to the user's breathing state in the second signal; When it is determined that the first respiration signal is unreliable, the first respiration signal is switched to the second respiration signal.
4. The method according to claim 1, characterized in that: Determining the reliability of the first breathing signal includes: comparing the first signal quality with a first threshold; comparing the second signal quality with a second threshold; When the first signal quality is lower than the first threshold and the second signal quality is higher than the second threshold, it is determined that the first breathing signal is unreliable.
5. The method according to claim 1, characterized in that The method further comprises: When it is determined that the first breathing signal is unreliable, information indicating that the input wire corresponding to the first breathing signal is not compatible with the state of the user is output.
6. The method according to any one of claims 1 to 5, characterized in that The second signal is at least one of a pulse wave signal and an electrocardiogram signal.
7. The method according to claim 3, characterized in that The second signal is a pulse wave signal, and the method further includes: Performing high-pass filtering on the pulse wave signal to obtain a filtered pulse wave signal; and A slope envelope and / or an amplitude envelope of the filtered pulse wave signal is extracted.
8. The method according to claim 7, characterized in that In the step of calculating the second breathing signal, the second breathing signal is obtained according to the slope envelope and / or the amplitude envelope.
9. The method according to claim 8, characterized in that In the step of calculating the second signal quality, The second signal quality is calculated based on at least one of the amplitude of the second breathing signal, the proportion of signal energy in the first frequency range of the second breathing signal to the total energy, the proportion of the second frequency range centered on the main frequency in the second breathing signal to the total frequency range, and the statistic of the pulse interval of the pulse wave signal.
10. The method according to claim 3, characterized in that: The second signal is an electrocardiogram signal, and the method further comprises: extracting the RR interval and QT interval of the electrocardiogram signal, and The second respiratory signal is obtained according to the RR interval and the QT interval.
11. The method according to claim 10, characterized in that The method further comprises: judging whether there is arrhythmia according to the second signal, In the step of calculating the second signal quality, The second signal quality is calculated based on at least one of whether there is arrhythmia, the amplitude of the second respiratory signal, the signal-to-noise ratio of the electrocardiogram signal, the signal proportion of a third frequency range centered on the main frequency in the second respiratory signal, and the statistics of the RR interval.
12. A device for determining the reliability of a respiratory signal, characterized in that: The device comprises: A processor, which performs the steps of the method according to any one of claims 1 to 11.
13. The breathing signal reliability determination device according to claim 12, characterized in that: The breathing signal reliability judgment device also includes: A first signal source, which outputs a first breathing signal according to a first input signal; At least one second signal source outputs a second signal according to a second input signal.
14. The breathing signal reliability determination device according to claim 13, characterized in that: The processor is configured at the first signal source and / or the at least one second signal source.
15. A non-transitory computer-readable storage medium for storing a computer program, characterized in that: When the computer program is executed by a computer, the computer is caused to execute the method according to any one of claims 1 to 11.