Readable storage medium, electronic apparatus, and implantable medical device

Abstract

The present invention provides a readable storage medium, an electronic apparatus, and an implantable medical device. The readable storage medium stores a computer program. The computer program, when executed by a processor, implements the following steps: acquiring a preset number of pulmonary respiratory impedance values of a target subject; calculating a sum of absolute pulmonary respiratory impedance values of the target subject on the basis of the absolute values of the preset number of pulmonary respiratory impedance values of the target subject within a preset duration; and determining whether the target subject experiences an apnea event or a hypopnea event on the basis of the sum of the absolute pulmonary respiratory impedance values of the target subject. The present invention enables accurate detection of sleep respiratory abnormality events including sleep apnea and sleep hypopnea.

Description

Readable storage medium, electronic device, and implantable medical device Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a readable storage medium, an electronic device and an implantable medical device. Background Art

[0002] Sleep apnea (SA) is a major type of sleep disorder breathing (SDB). It refers to recurring pauses in breathing during sleep and includes obstructive sleep apnea (OSA) and central nervous system sleep apnea (CSA). OSA is the most common form of SA. It occurs when the throat muscles relax during sleep, leading to complete or partial obstruction of the upper airway. Each episode of OSA affects the heart by causing a decrease in oxygen (O2) in the blood and an increase in carbon dioxide (CO2). When these levels reach a certain level, the patient automatically awakens from sleep. Approximately 90% of SA patients have OSA. CSA, on the other hand, occurs when a neurological abnormality prevents the brain from transmitting breathing commands to the respiratory muscles. It primarily occurs in patients with heart failure (HF).

[0003] Apnea refers to an absence of airflow for more than 10 seconds between two breathing cycles, while hypopnea refers to a decrease in airflow of 50% or more for more than 10 seconds, accompanied by at least 3% blood oxygen desaturation.

[0004] Sleep apnea (SDB) is typically measured by combining symptoms with the Apnea-Hypopnea Index (AHI), which is defined as: AHI = (number of apneas + number of hypopneas) / number of hours of breathing. An AHI greater than 5 is considered SDB.

[0005] The current gold standard for SDB screening is polysomnography (PSG) in a sleep lab (SL). However, the scarcity of SLs results in a waiting time of up to a year!

[0006] It should be noted that the information disclosed in the background technology section of this application is only intended to deepen the understanding of the general background technology of this application, and should not be regarded as an admission or any form of implication that the information constitutes prior art already known to those skilled in the art. Summary of the Invention

[0007] The object of the present invention is to provide a readable storage medium, an electronic device and an implantable medical device, which can accurately detect abnormal sleep breathing events such as sleep apnea and sleep hypopnea.

[0008] To achieve the above object, the present invention provides a readable storage medium, wherein the readable storage medium stores a computer program, and when the computer program is executed by a processor, the following steps are implemented:

[0009] obtaining a preset number of lung respiratory impedances of the target subject;

[0010] Calculating a sum of the absolute values ​​of the pulmonary respiratory impedance of the target subject according to a preset number of absolute values ​​of the pulmonary respiratory impedance of the target subject within a preset time period;

[0011] Whether an apnea event or a hypopnea event occurs in the target subject is determined according to the sum of the absolute values ​​of the lung respiratory impedance of the target subject.

[0012] Optionally, obtain the target subject's lung respiratory impedance, including:

[0013] Acquire the transthoracic impedance of the target object;

[0014] The cardiac activity impedance is removed from the transthoracic impedance to obtain the pulmonary respiratory impedance.

[0015] Optionally, removing the cardiac activity impedance from the transthoracic impedance to obtain the pulmonary respiratory impedance includes:

[0016] The transthoracic impedance is subjected to bandpass filtering according to a preset cutoff frequency range to filter out the cardiac activity impedance, thereby obtaining the pulmonary respiratory impedance.

[0017] Optionally, the preset cutoff frequency range is [0.05 Hz, 0.5 Hz].

[0018] Optionally, removing the cardiac activity impedance from the transthoracic impedance to obtain the pulmonary respiratory impedance includes:

[0019] Acquire the cardiac activity impedance corresponding to the time series of the transthoracic impedance according to the pre-fitted cardiac activity impedance time series diagram;

[0020] The pulmonary respiratory impedance is obtained according to the difference between the transthoracic impedance and the cardiac activity impedance of the corresponding time series.

[0021] Optionally, the target subject's cardiac activity impedance time series diagram is obtained by fitting the following steps:

[0022] Acquiring a first transthoracic impedance and a second transthoracic impedance of the target object within the same ventricular activity cycle, wherein the first transthoracic impedance is the transthoracic impedance corresponding to the end of ventricular diastole, and the second transthoracic impedance is the transthoracic impedance corresponding to the end of ventricular systole;

[0023] obtaining a cardiac activity impedance change amplitude of the target subject according to a difference between the first transthoracic impedance and the second transthoracic impedance;

[0024] A linear fitting is performed according to the amplitude of the cardiac activity impedance change of the target object and the time sequence of the intracardiac potential diagram of the target object to obtain the cardiac activity impedance time sequence diagram of the target object.

[0025] Optionally, acquiring the first transthoracic impedance and the second transthoracic impedance of the target object in the same ventricular activity cycle includes:

[0026] When the apex of the R wave of the electrocardiogram signal of the target object is detected, obtaining a first transthoracic impedance of the target object;

[0027] When a preset time interval is reached, a second transthoracic impedance of the target object is obtained.

[0028] Optionally, the preset time interval is 180 milliseconds to 200 milliseconds.

[0029] Optionally, when the computer program is executed by a processor, the following steps are further implemented:

[0030] Creating a buffer capable of storing a preset number of absolute values ​​of lung respiratory impedance;

[0031] Determining whether the total number of pulmonary respiratory impedances obtained so far is less than or equal to the preset number;

[0032] If yes, then the absolute value of the currently acquired pulmonary respiratory impedance is stored in the buffer in order;

[0033] If not, the absolute value of the pulmonary respiratory impedance stored first in the buffer is removed, and the absolute value of the pulmonary respiratory impedance currently obtained is stored in the tail position of the buffer.

[0034] Optionally, when the computer program is executed by a processor, the following steps are further implemented:

[0035] The sum of the absolute values ​​of the pulmonary respiratory impedance of the target object is calculated according to the absolute values ​​of the preset number of pulmonary respiratory impedances stored in the buffer.

[0036] Optionally, judging whether the target subject has an apnea event or a hypopnea event based on the sum of absolute values ​​of the target subject's lung respiratory impedance includes:

[0037] Determining whether the sum of the absolute values ​​of the lung respiratory impedance of the target subject is less than or equal to a pre-acquired apnea impedance threshold, and if so, determining that an apnea event occurs in the target subject;

[0038] If the sum of the absolute values ​​of the lung respiratory impedance of the target subject is greater than the apnea impedance threshold, it is determined whether the sum of the absolute values ​​of the lung respiratory impedance of the target subject is less than or equal to a pre-acquired hypopnea impedance threshold. If so, it is determined that a hypopnea event has occurred in the target subject.

[0039] Optionally, the apnea impedance threshold and the hypopnea impedance threshold are obtained by the following steps:

[0040] Obtaining the sum of absolute values ​​of the pulmonary respiratory impedance of the target subject in a resting state;

[0041] Obtaining the apnea impedance threshold according to a first preset proportional coefficient and the sum of the absolute values ​​of the lung respiratory impedance of the target subject in a resting state;

[0042] Obtaining the hypopnea impedance threshold according to a second preset proportional coefficient and the sum of the absolute values ​​of the lung respiratory impedance of the target subject in a resting state;

[0043] The second preset proportional coefficient is greater than the first preset proportional coefficient.

[0044] Optionally, the first preset proportional coefficient is 0.05-0.10, and the second preset proportional coefficient is 0.50.

[0045] Optionally, when the computer program is executed by a processor, the following steps are further implemented:

[0046] Whether the target subject has sleep apnea or not is determined based on the total number of apnea events and hypopnea events occurring in the target subject within a unit time.

[0047] To achieve the above objectives, the present invention also provides an electronic device, a processor and the readable storage medium described above.

[0048] To achieve the above-mentioned object, the present invention further provides an implantable medical device, which includes the above-mentioned readable storage medium or the above-mentioned electronic device.

[0049] Compared with the prior art, the readable storage medium, electronic device, and implantable medical device provided by the present invention have the following beneficial effects:

[0050] The present invention obtains a preset number of lung respiratory impedances of a target subject; then, based on the absolute values ​​of the preset number of lung respiratory impedances of the target subject within a preset time period, calculates the sum of the absolute values ​​of the lung respiratory impedances of the target subject; and then, based on the sum of the absolute values ​​of the lung respiratory impedances of the target subject, determines whether the target subject has experienced an apnea event or a hypopnea event. Because the human respiratory rate is different under normal conditions and under apnea or hypopnea conditions, and the change in the human lung respiratory impedance includes both impedance changes caused by changes in the distance between the measuring electrode pairs due to lung respiration and impedance changes caused by changes in the airflow between the measuring electrode pairs due to lung respiration, the present invention can improve the detection accuracy of apnea events or hypopnea events by determining whether the target subject has experienced an apnea event or a hypopnea event based on the impedance changes caused by lung respiration, thereby facilitating timely intervention and treatment when sleep breathing abnormalities occur. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] FIG1 is a schematic diagram of sleep apnea monitoring based on respiratory signals of transthoracic impedance;

[0052] FIG2 is a schematic diagram of transthoracic impedance measurement;

[0053] FIG3 is a specific example diagram of a respiratory signal based on transthoracic impedance;

[0054] FIG4 is a schematic diagram of a respiratory signal during sleep apnea provided in a specific example;

[0055] FIG5 is a schematic diagram of a respiratory signal during sleep apnea provided by another specific example;

[0056] FIG6 is a complete anatomical diagram of sleep apnea monitoring based on transthoracic impedance measurement;

[0057] FIG7 a is a schematic diagram showing a comparison between an intracardiac potential map signal and a transthoracic impedance signal provided by a specific example;

[0058] FIG7 b is a schematic diagram showing a comparison between an intracardiac potential map signal and a transthoracic impedance signal provided by another specific example;

[0059] FIG8 is a schematic diagram showing a comparison between a polysomnographic signal and a transthoracic impedance signal provided in a specific example;

[0060] FIG9 is a flow chart of steps that can be implemented by a readable storage medium according to an embodiment of the present invention;

[0061] FIG10 is a diagram showing the temporal relationship between cardiac activity impedance and ECG (endocardial potential graph) according to one embodiment of the present invention;

[0062] FIG11 is a time series diagram of cardiac activity impedance obtained by linear fitting according to one embodiment of the present invention;

[0063] FIG12 is a specific flowchart of sleep apnea detection provided by one embodiment of the present invention.

[0064] The reference numerals are as follows: housing 10; distal electrode 20; proximal electrode 30. DETAILED DESCRIPTION

[0065] The following is a further detailed description of the readable storage medium, electronic device and implantable medical device proposed in the present invention in conjunction with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will become clearer. It should be noted that the drawings are in a very simplified form and are not in precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In order to make the purposes, features and advantages of the present invention more obvious and easy to understand, please refer to the drawings. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no technical significance. Any modification of the structure, change in the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed in the present invention without affecting the efficacy and purpose that can be achieved by the present invention.

[0066] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply the existence of any such actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or device comprising the element.

[0067] In addition, in the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0068] The core concept of the present invention is to provide a readable storage medium, an electronic device and an implantable medical device that can accurately detect abnormal sleep breathing events such as sleep apnea and sleep hypopnea.

[0069] It should be noted that the readable storage medium provided by the present invention can be applied to the electronic device provided by the present invention, and the electronic device can be configured in the implantable medical device provided by the present invention, and the implantable medical device can be, but is not limited to, an implantable cardioverter defibrillator (ICD), an implantable cardiac pacemaker, an implantable neurostimulator, etc. It should also be noted that, as can be understood by those skilled in the art, the "distal end" referred to herein refers to the end close to the lesion, and the "proximal end" refers to the end close to the operator.

[0070] For ease of understanding, before introducing the readable storage medium, electronic device, and implantable medical device provided by the present invention, the research background of the present invention is first described.

[0071] In the field of implantable medical devices, such as ICD (Implantable cardioverter defibrillator), the diagnosis of SA (Sleep Apnea) is generally based on transthoracic impedance (Z th ) is achieved by recording and analyzing the respiratory signal (RS) measured, as shown in Figure 1, which is a schematic diagram of sleep apnea monitoring based on the respiratory signal of transthoracic impedance. The ApneaHypopnea Index in the figure represents the respiratory abnormality index.

[0072] Please continue to refer to Figure 2, which is a schematic diagram of transthoracic impedance measurement. As shown in Figure 2, taking an implantable cardioverter defibrillator as an example, a small pulse (e.g., I = 320 uA) can be injected between the implantable cardioverter defibrillator housing 10 and the distal electrode 20 (the electrode located relatively at the distal end) of the atrial electrode lead (bipolar electrode lead). Then, a voltage drop dV is measured between the implantable cardioverter defibrillator housing 10 and the proximal electrode 30 (the electrode located relatively at the proximal end) of the atrial electrode lead. Then, based on the measured voltage drop dV and the current I of the injected pulse, the transthoracic impedance Z is calculated. th = dV / I. It should be noted, as those skilled in the art will appreciate, that the distal electrode 20 used to inject the measurement current retains a residual charge after the current is injected, and the corresponding voltage value is significant for transthoracic impedance. Using this distal electrode 20 to measure transthoracic impedance makes it difficult to obtain an accurate measurement. However, the proximal electrode does not have any residual charge. Therefore, by measuring the voltage drop dV between the implantable cardioverter-defibrillator housing 10 and the proximal electrode 30 of the atrial lead, a relatively accurate transthoracic impedance measurement can be obtained.

[0073] Please continue to refer to Figure 3, which is a specific example diagram of a respiratory signal based on transthoracic impedance. As shown in Figure 3, the "+" sign at the peak position identifies the first transthoracic impedance of the corresponding respiratory cycle (inspiration-expiration), and the "+" sign at the trough position identifies the second transthoracic impedance of the corresponding respiratory cycle.

[0074] Under normal circumstances, when at rest, such as when sleeping, the human respiratory rate is 10 to 20 breaths per minute, meaning that the human respiratory cycle is normally 3 to 6 seconds. Please continue to refer to Figures 4 and 5 , where Figure 4 is a schematic diagram of a respiratory signal during sleep apnea, provided as a specific example; and Figure 5 is a schematic diagram of a respiratory signal during sleep apnea, provided as another specific example. As shown in Figures 4 and 5 , the respiratory cycle during sleep apnea (SA) is typically 10 to 60 seconds long.

[0075] Please continue to refer to Figure 6, which is a complete anatomical diagram of sleep apnea monitoring based on measuring transthoracic impedance. As shown in Figure 6, transthoracic impedance Z th The measurement path of the transthoracic impedance Z includes not only the lung lobes but also the heart. th The signal is composed of impedance changes caused by the breathing and respiration of the lungs, as well as impedance changes caused by the contraction and relaxation of the heart. Specifically, Z th =Z th-heart +Z th-lung , where Z th-heart is the impedance generated by cardiac contraction and relaxation (hereinafter referred to as cardiac activity impedance), Z th-lungThe impedance generated by lung respiration (hereinafter referred to as lung respiration impedance). Studies have shown that the electrical impedance of different biological tissues is very different. For example, the electrical impedance of blood, myocardium and lungs are 150Ω / cm, 750Ω / cm and 1275Ω / cm respectively. Considering these factors, it can be seen that the impedance of cardiac activity Z th-heart The change of includes both the impedance change caused by the change of the distance between the measuring electrodes due to the contraction and relaxation of the heart and the impedance change caused by the change of the blood flow between the measuring electrodes due to the contraction and relaxation of the heart. Similarly, the pulmonary respiratory impedance Z th-lung The change in impedance includes both the change in the distance between the measuring electrode pairs caused by the breathing of the lungs and the change in the airflow between the measuring electrode pairs caused by the breathing of the lungs.

[0076] Please continue to refer to Figures 7a and 7b, wherein Figure 7a is a schematic diagram of the comparison between the intracardiac potential map signal and the transthoracic impedance signal provided by a specific example; Figure 7b is a schematic diagram of the comparison between the intracardiac potential map signal and the transthoracic impedance signal provided by another specific example. As shown in Figures 7a and 7b, the contraction and expansion movement of the heart will cause the transthoracic impedance Z th ups and downs.

[0077] Generally speaking, heart rate is several times faster than respiratory rate. For example, a person's heart rate while sleeping is about 50 beats per minute (BPM), while their respiratory rate is only about 10 breaths per minute (BPM). Although there's no fixed proportional relationship between heart rate and respiratory rate, they are normally closely linked: a faster heart rate leads to a higher respiratory rate, while a slower heart rate leads to a lower respiratory rate.

[0078] Please continue to refer to Figure 8, which is a schematic diagram of the comparison of polysomnography signals and transthoracic impedance signals provided by a specific example. As shown in Figure 8, the upper half of the figure is the PSG (polysomnography) signal, and the lower half is the Z th (Transthoracic impedance) signal, the area framed by the two rectangles is the two SA (sleep apnea) events. Since the main component of the PSG (polysomnography) signal is the air pressure in the nostrils, which has no direct relationship with the heartbeat, there is almost no fluctuation in the PSG (polysomnography) signal during the SA (sleep apnea) period. In contrast, the transthoracic impedance Z th The signal still has obvious fluctuations even during SA (sleep apnea). Because during SA (sleep apnea), although there is no breathing, there is still heartbeat, which means that the lung respiratory impedance Z th-lung It is an almost fixed value, and the fluctuating part is actually the cardiac activity impedance Z th-heartIn fact, in the non-SA (sleep apnea) interval outside the rectangular box, the lung respiratory impedance Zt h-lung and cardiac activity impedance Z th-heart Both exist, but sometimes the cardiac activity impedance Z th-heart The magnitude of the lung respiratory impedance Z th-lung Sometimes it is small and not so obvious, sometimes it is large and obvious. Especially when the transthoracic impedance Z th When the measurement is achieved through ventricular electrodes, the cardiac activity impedance Z th-heart Transthoracic impedance Z th The impact cannot be ignored.

[0079] In summary, because cardiac activity impedance cannot reflect whether apnea occurs, it is necessary to filter out cardiac activity impedance and retain only pulmonary respiratory impedance. That is, the only impedance truly relevant to SA (sleep apnea) monitoring is transthoracic impedance Z. th Pulmonary respiratory impedance Z th-lung , transthoracic impedance Z th The cardiac activity impedance Z th-heart It will affect the accurate monitoring of SA (sleep apnea) and must be removed.

[0080] Based on this, the present invention provides a readable storage medium having a computer program stored therein. Please refer to FIG9 , which is a flowchart of the steps that can be implemented by the readable storage medium provided in one embodiment of the present invention. As shown in FIG9 , when the computer program is executed by a processor, the following steps are implemented:

[0081] Step S100: Acquire the lung respiratory impedance of the target object.

[0082] Step S200: Calculate the sum of the absolute values ​​of the pulmonary respiratory impedance of the target object according to a preset number of absolute values ​​of the pulmonary respiratory impedance of the target object within a preset time period.

[0083] Step S300: Determine whether the target subject has an apnea event or a hypopnea event based on the sum of the absolute values ​​of the target subject's lung respiratory impedance.

[0084] Since the human respiratory rate is different under normal conditions and in apnea or hypopnea conditions, and the change in the human lung respiratory impedance includes both the impedance change caused by the change in the distance between the measuring electrode pairs due to the lung's breathing and the impedance change caused by the change in the airflow between the measuring electrode pairs due to the lung's breathing, the present invention can improve the detection accuracy of apnea or hypopnea events by judging whether the target subject has experienced an apnea event or a hypopnea event based on the impedance change caused by lung breathing, thereby facilitating timely intervention and treatment when sleep breathing disorders occur. It should be noted that, as can be understood by those skilled in the art, the sum of the absolute values ​​of the lung respiratory impedance of the target subject is equal to the sum of the absolute values ​​of the lung respiratory impedance of the target subject for a preset number of times within a preset time period.

[0085] In some exemplary embodiments, the preset duration is 10 seconds.

[0086] As can be seen from the above, the breathing cycle during sleep apnea (SA) is generally 10 to 60 seconds long. Therefore, by setting the preset duration to 10 seconds, not only the detection accuracy of the present invention can be guaranteed, but also the detection efficiency of the present invention can be improved.

[0087] In some exemplary embodiments, obtaining the target subject's pulmonary respiratory impedance includes:

[0088] Acquire the transthoracic impedance of the target object;

[0089] The cardiac activity impedance is removed from the transthoracic impedance to obtain the pulmonary respiratory impedance.

[0090] Since it is difficult to directly measure the pulmonary respiratory impedance, while the transthoracic impedance is easier to measure, and as mentioned above, the transthoracic impedance is composed of the cardiac activity impedance and the pulmonary respiratory impedance, the pulmonary respiratory impedance can be obtained by removing the cardiac activity impedance from the transthoracic impedance.

[0091] Furthermore, in some exemplary embodiments, removing the cardiac activity impedance from the transthoracic impedance to obtain the pulmonary respiratory impedance includes:

[0092] The transthoracic impedance is subjected to bandpass filtering according to a preset cutoff frequency range to filter out the cardiac activity impedance, thereby obtaining the pulmonary respiratory impedance.

[0093] Regardless of whether the heart rate and respiratory rate are abnormal, the cardiac activity impedance Z th-heart and lung respiratory impedance Z th-lung are in significantly different frequency bands, and the lung respiratory impedance Z th-lungThe DC component in the data also does not contain information related to breathing. Therefore, by using a bandpass filter with the preset cutoff frequency range to perform bandpass filtering on the transthoracic impedance, the cardiac activity impedance can be filtered out, and the pulmonary respiratory impedance can be filtered out, thereby obtaining the pulmonary respiratory impedance.

[0094] Furthermore, the preset cutoff frequency range is [0.05 Hz, 0.5 Hz].

[0095] Due to the cardiac activity impedance Z th-heart The frequency band is above 1.0Hz (equivalent to 60BPM) and decreases during sleep, for example, it may decrease to above 0.75Hz (equivalent to 45BPM). th-lung The frequency band is below 0.5Hz (equivalent to 30BPM) and decreases during sleep, for example, it may drop to below 0.25Hz (equivalent to 15BPM). Therefore, bandpass filtering the transthoracic impedance using a bandpass filter with a cutoff frequency range of [0.05Hz, 0.5Hz] can filter out the cardiac activity impedance and filter out the pulmonary respiratory impedance. Bandpass filtering the transthoracic impedance can filter out the cardiac activity impedance and filter out the pulmonary respiratory impedance.

[0096] In some other exemplary embodiments, removing the cardiac activity impedance from the transthoracic impedance to obtain the pulmonary respiratory impedance includes:

[0097] Acquire the cardiac activity impedance corresponding to the time series of the transthoracic impedance according to the pre-fitted cardiac activity impedance time series diagram;

[0098] The pulmonary respiratory impedance is obtained according to the difference between the transthoracic impedance and the cardiac activity impedance of the corresponding time series.

[0099] As can be seen from the above, the transthoracic impedance is composed of the pulmonary respiratory impedance and the cardiac activity impedance. Therefore, by subtracting the transthoracic impedance from the corresponding cardiac activity impedance, the cardiac activity impedance in the transthoracic impedance can be removed to obtain the pulmonary respiratory impedance.

[0100] Furthermore, in some exemplary embodiments, the target subject's cardiac activity impedance time series diagram is obtained by fitting the following steps:

[0101] Acquiring a first transthoracic impedance and a second transthoracic impedance of the target object within the same ventricular activity cycle, wherein the first transthoracic impedance is the transthoracic impedance corresponding to the end of ventricular diastole, and the second transthoracic impedance is the transthoracic impedance corresponding to the end of ventricular systole;

[0102] obtaining a cardiac activity impedance change amplitude of the target subject according to a difference between the first transthoracic impedance and the second transthoracic impedance;

[0103] A linear fitting is performed according to the amplitude of the cardiac activity impedance change of the target object and the time sequence of the intracardiac potential diagram of the target object to obtain the cardiac activity impedance time sequence diagram of the target object.

[0104] Specifically, please refer to FIG10, which is a time series relationship diagram of cardiac activity impedance and ECG (internal cardiac potential map) provided by one embodiment of the present invention. As shown in FIG10, the apex of the R wave of the ECG (internal cardiac potential map) corresponds to the end of ventricular diastole, that is, when the ventricle is most fully filled with blood. Therefore, the cardiac activity impedance Z th-heart The ventricle contracts and pumps the blood out of the ventricle until the starting point of the T wave. At the starting point of the T wave, it corresponds to the end of ventricular contraction, and the cardiac activity impedance Z th- heart Reach the minimum value. Thus, by obtaining the first transthoracic impedance collected at the end of ventricular diastole and the second transthoracic impedance collected at the end of ventricular systole, the cardiac activity impedance change amplitude can be obtained according to the difference between the first transthoracic impedance and the second transthoracic impedance, and then based on the timing of the intracardiac potential map, a linear fit can be performed according to the cardiac activity impedance change amplitude to fit the cardiac activity impedance timing diagram. Please refer to Figure 11, which is a linearly fitted cardiac activity impedance timing diagram provided by one embodiment of the present invention. Among them, the upper half represents the ECG (intracardiac potential map) signal, and the lower half represents the cardiac activity impedance Z th-heart Signal, the dotted line in the lower half is the cardiac activity impedance timing diagram fitted according to the amplitude of the cardiac activity impedance change and the corresponding time points of the first transthoracic impedance and the second transthoracic impedance. The solid line in the lower half represents the real cardiac activity impedance timing diagram. By comparison, it can be seen that the fitted cardiac activity impedance timing diagram is very close to the real cardiac activity impedance timing diagram.

[0105] Furthermore, in some exemplary embodiments, obtaining the first transthoracic impedance and the second transthoracic impedance of the target object in the same ventricular activity cycle includes:

[0106] When the apex of the R wave of the electrocardiogram signal of the target object is detected, obtaining a first transthoracic impedance of the target object;

[0107] When a preset time interval is reached, a second transthoracic impedance of the target object is obtained.

[0108] Specifically, as can be seen from the above, the apex of the R wave of the ECG (internal cardiac potential map) corresponds to the end of ventricular diastole, and the starting point of the T wave of the ECG (internal cardiac potential map) corresponds to the end of ventricular contraction. Therefore, when the apex of the R wave of the target object's electrocardiographic signal is detected, the transthoracic impedance collected is the first transthoracic impedance (i.e., the transthoracic impedance corresponding to the end of ventricular diastole). In addition, since the starting point of the T wave is difficult to detect accurately, but in general, the width of the QRS wave is determined, and the length of the ST segment (the flat line from the end of the QRS complex to the beginning of the T wave, reflecting that all parts of the ventricle are excited and in a depolarized state, so there is no potential difference) is also determined. Therefore, the preset time interval can be determined based on the width of the QRS wave and the length of the ST segment, so that it can be ensured that when the preset time interval is reached, the transthoracic impedance obtained is the second transthoracic impedance (i.e., the transthoracic impedance corresponding to the end of ventricular contraction).

[0109] Furthermore, in some exemplary embodiments, the preset time interval is 180 milliseconds to 200 milliseconds.

[0110] Specifically, the width of the QRS wave is 60 milliseconds to 100 milliseconds, and the length of the ST segment (the flat line from the end of the QRS wave group to the beginning of the T wave, reflecting that all parts of the ventricle are excited and in a depolarized state, so there is no potential difference) is 100 milliseconds to 150 milliseconds. Therefore, within the same ventricular activity cycle, the time from the peak of the R wave to the starting point of the T wave can be roughly 180 to 200 milliseconds. Therefore, by setting the preset time interval to 180 milliseconds to 200 milliseconds, it can be ensured that the transthoracic impedance collected when the preset time interval is reached is the second transthoracic impedance (that is, the transthoracic impedance corresponding to the end of ventricular contraction).

[0111] In some exemplary embodiments, when the computer program is executed by a processor, the following steps are further implemented:

[0112] Creating a buffer capable of storing a preset number of absolute values ​​of lung respiratory impedance;

[0113] Determining whether the total number of pulmonary respiratory impedances obtained so far is less than or equal to the preset number;

[0114] If yes, then the absolute value of the currently acquired pulmonary respiratory impedance is stored in the buffer in order;

[0115] If not, the absolute value of the pulmonary respiratory impedance stored first in the buffer is removed, and the absolute value of the pulmonary respiratory impedance currently obtained is stored in the tail position of the buffer.

[0116] Specifically, the buffer is a first-in-first-out buffer FiFo_z (store|Zth-lungF(0) |,|Z th-lungF(1) |, ..., |Z th- lungF(i) |, ..., |Z th-lungF(N) |). Thus, by sequentially storing the acquired absolute values ​​of the pulmonary respiratory impedance in the buffer FiFo_z according to a first-in-first-out rule, the real-time calculation of the sum of the absolute values ​​of the pulmonary respiratory impedance can be facilitated while using less memory and computational effort.

[0117] Please continue to refer to Figure 12, which is a specific flow chart of sleep breathing abnormality detection provided by one embodiment of the present invention. As shown in Figure 12, in the initial state, the number of samples received (i.e., the number of lung respiratory impedances obtained) is 0 (i.e., Num_z = 0), and the absolute value of the newly obtained lung respiratory impedance is taken to obtain a new sample | Z th-lungF |, and update the sample count (ie, Num_z = Num_z + 1), determine whether the updated sample count Num_z is less than or equal to the preset number N, if so, the newly acquired sample | Z th- lungF | are stored in the buffer FiFo_z in order. If not (ie the updated sample count Num_z is greater than the preset number), the first sample stored in the buffer FiFo_z | Z th-lungF(0) |Remove from the buffer FiFo_z and replace the newly acquired sample |Z th-lungF |Insert into the tail position of the buffer FiFo_z.

[0118] In some exemplary embodiments, when the computer program is executed by a processor, the following steps are further implemented:

[0119] The sum of the absolute values ​​of the pulmonary respiratory impedance of the target object is calculated according to the absolute values ​​of the preset number of pulmonary respiratory impedances stored in the buffer.

[0120] Specifically, please refer to FIG12. As shown in FIG12, in the initial state, the buffer accumulated sum value Sum_z=0. When a new sample |Z is obtained, th-lungF After |, if the updated sample count Num_z is less than or equal to the preset number N, the new buffer cumulative sum value is calculated according to the following formula: Sum_new = Sum_z + |Z th-lungF |, and the new buffer cumulative sum value Sum_new is used as the updated buffer cumulative sum value Sum_z, that is, Sum_z = Sum_new; if the updated sample count Num_z is greater than the preset number N, the new buffer cumulative sum value is calculated according to the following formula: Sum_new = Sum_z - |Z th-lungF(0) |+|Z th-lungF|, and the new buffer cumulative sum value Sum_new is used as the updated buffer cumulative sum value Sum_z, that is, Sum_z = Sum_new. It should be noted that, as will be understood by those skilled in the art, when the updated sample count Num_z is greater than or equal to the preset number N, the updated buffer cumulative sum value is the sum of the absolute values ​​of the pulmonary respiratory impedance. In other words, at this time, whether the target subject has experienced an apnea event or a hypopnea event can be determined based on the updated buffer cumulative sum value Sum_z.

[0121] In some exemplary embodiments, determining whether the target subject has an apnea event or a hypopnea event based on the sum of absolute values ​​of the target subject's lung respiratory impedance includes:

[0122] Determining whether the sum of the absolute values ​​of the lung respiratory impedance of the target subject is less than or equal to a pre-acquired apnea impedance threshold, and if so, determining that an apnea event occurs in the target subject;

[0123] If the sum of the absolute values ​​of the lung respiratory impedance of the target subject is greater than the apnea impedance threshold, it is determined whether the sum of the absolute values ​​of the lung respiratory impedance of the target subject is less than or equal to a pre-acquired hypopnea impedance threshold. If so, it is determined that a hypopnea event has occurred in the target subject.

[0124] Please continue to refer to FIG12. As shown in FIG12, when the updated sample count Num_z is greater than or equal to the preset number N, if the updated buffer cumulative sum Sum_z (i.e., the sum of the absolute values ​​of the pulmonary respiratory impedance) is less than or equal to the apnea impedance threshold Z_ apnea , then it reports that apnea SA is detected; if the updated buffer cumulative sum value Sum_z (the sum of the absolute values ​​of the lung respiratory impedance) is greater than the apnea impedance threshold Z_ apnea , then continue to determine whether the updated buffer cumulative sum value Sum_z (the sum of the absolute values ​​of the lung respiratory impedance) is less than or equal to the insufficient breathing impedance threshold Z_ hypopnea If the updated buffer cumulative sum value Sum_z (the sum of the absolute values ​​of the lung respiratory impedance) is less than or equal to the hypopnea impedance threshold Z_ hypopnea , then the report detects sleep hypopnea.

[0125] In some exemplary embodiments, the apnea impedance threshold and the hypopnea impedance threshold are obtained by the following steps:

[0126] Obtaining the sum of absolute values ​​of the pulmonary respiratory impedance of the target subject in a resting state;

[0127] Obtaining the apnea impedance threshold according to a first preset proportional coefficient and the sum of the absolute values ​​of the lung respiratory impedance of the target subject in a resting state;

[0128] Obtaining the hypopnea impedance threshold according to a second preset proportional coefficient and the sum of the absolute values ​​of the lung respiratory impedance of the target subject in a resting state;

[0129] The second preset proportional coefficient is greater than the first preset proportional coefficient.

[0130] Specifically, the sum of the absolute values ​​of the pulmonary respiratory impedance of the target object in the resting state can be obtained based on the sum of the absolute values ​​of a preset number of pulmonary respiratory impedances of the target object in the resting state within a preset time period.

[0131] Assuming that the first preset proportional coefficient is a, the sum of the absolute values ​​of the lung respiratory impedance of the target object in the resting state is Sum_zr, then the apnea impedance threshold Z_ apnea The calculation formula is: apnea =a*Sum_zr.

[0132] Assuming that the second preset proportional coefficient is b, the sum of the absolute values ​​of the lung respiratory impedance of the target object in the resting state is Sum_zr, then the insufficient breathing impedance threshold Z_ hypopnea The calculation formula is: hypopnea =b*Sum_zr.

[0133] In some exemplary embodiments, the first preset proportional coefficient is 0.05-0.10, and the second preset proportional coefficient is 0.50.

[0134] Since apnea refers to the absence of airflow for more than 10 seconds between two breathing cycles, and hypopnea refers to a decrease of 50% or more of the respiratory airflow for more than 10 seconds, by setting the first preset proportional coefficient to 0.05-0.10 and the second preset proportional coefficient to 0.50, it can be effectively ensured that the apnea impedance threshold Z_ apnea and the hypopnea impedance threshold Z_ hypopnea Accurately detects abnormal sleep breathing events such as sleep apnea and sleep hypopnea.

[0135] In some exemplary embodiments, when the computer program is executed by a processor, the following steps are further implemented:

[0136] Whether the target subject has sleep apnea or not is determined based on the total number of apnea events and hypopnea events occurring in the target subject within a unit time.

[0137] Specifically, when the total number of apnea events and hypopnea events occurring to the target subject within a unit time is greater than 5, it can be determined that the target subject has sleep apnea.

[0138] It should be noted that, as will be appreciated by those skilled in the art, the readable storage medium provided by the present invention can adopt any combination of one or more computer-readable media. The readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, a system, device or component of electricity, magnetism, light, electromagnetic, infrared or semiconductor, or any combination thereof. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer hard disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In this article, a computer-readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, device or device or used in combination with it.

[0139] Furthermore, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, which carries a computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wire, optical cable, RF, etc., or any suitable combination thereof.

[0140] Based on the same inventive concept, the present invention further provides an electronic device comprising a processor and the readable storage medium described above. Since the electronic device provided by the present invention and the readable storage medium provided above are based on the same inventive concept, the electronic device provided by the present invention has at least all the beneficial effects of the readable storage medium provided by the present invention. Therefore, the beneficial effects of the electronic device provided by the present invention will not be further elaborated herein.

[0141] The processor referred to in the present invention may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the electronic device, and uses various interfaces and lines to connect the various parts of the entire electronic device. The processor implements the various functions of the electronic device by running or executing the computer program stored in the readable storage medium and calling the data stored in the readable storage medium.

[0142] Based on the same inventive concept, the present invention further provides an implantable medical device, comprising the readable storage medium or the electronic device described above. Because the implantable medical device provided by the present invention and the readable storage medium provided above are based on the same inventive concept, the implantable medical device provided by the present invention possesses at least all the beneficial effects of the readable storage medium provided by the present invention. Therefore, the beneficial effects of the implantable medical device provided by the present invention will not be further elaborated herein.

[0143] In summary, compared with the prior art, the readable storage medium, electronic device, and implantable medical device provided by the present invention have the following beneficial effects:

[0144] The present invention obtains the lung respiratory impedance of a target subject; then, based on the absolute values ​​of a preset number of lung respiratory impedance measurements of the target subject within a preset time period, calculates the sum of the absolute values ​​of the lung respiratory impedance of the target subject; and then, based on the sum of the absolute values ​​of the lung respiratory impedance of the target subject, determines whether the target subject has experienced an apnea event or a hypopnea event. Because the human respiratory rate is different under normal conditions and under apnea or hypopnea conditions, and changes in the human lung respiratory impedance include both impedance changes caused by changes in the distance between the measuring electrode pairs due to lung respiration and impedance changes caused by changes in the airflow between the measuring electrode pairs due to lung respiration, the present invention can improve the detection accuracy of apnea events or hypopnea events by determining whether the target subject has experienced an apnea event or a hypopnea event based on impedance changes caused by lung respiration, thereby facilitating timely intervention and treatment when sleep breathing abnormalities occur.

[0145] It should be noted that the computer program code for performing the operations of the present invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (e.g., through the Internet using an Internet service provider).

[0146] It should be noted that the devices and methods disclosed in the embodiments of this document may also be implemented in other ways. The device embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architectures, functions, and operations of the devices, methods, and computer program products according to the various embodiments of this document. In this regard, each box in the flowchart or block diagram may represent a module, program, or part of the code, which contains one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions marked in the boxes may also occur in an order different from that marked in the accompanying drawings. For example, two consecutive boxes may actually be executed substantially in parallel, or they may sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart, may be implemented by a dedicated hardware-based system for performing the specified functions or actions, or may be implemented by a combination of dedicated hardware and computer instructions. In addition, the functional modules in the various embodiments of this document may be integrated together to form an independent part, or each module may exist independently, or two or more modules may be integrated to form an independent part.

[0147] It should also be noted that the above description is merely a description of preferred embodiments of the present invention and does not limit the scope of the present invention. Any changes or modifications made by persons skilled in the art based on the above disclosure are intended to fall within the scope of the claims. Obviously, various modifications and variations may be made by persons skilled in the art without departing from the spirit and scope of the present invention. Thus, to the extent such modifications and variations fall within the scope of the claims and their equivalents, the present invention is intended to encompass such modifications and variations.

Claims

1. A readable storage medium, characterized in that: The readable storage medium stores a computer program, and when the computer program is executed by the processor, the following steps are implemented: obtaining a preset number of lung respiratory impedances of the target subject; Calculating a sum of the absolute values ​​of the pulmonary respiratory impedance of the target subject according to a preset number of absolute values ​​of the pulmonary respiratory impedance of the target subject within a preset time period; Whether an apnea event or a hypopnea event occurs in the target subject is determined according to the sum of the absolute values ​​of the lung respiratory impedance of the target subject.

2. The readable storage medium according to claim 1, wherein Obtain the target subject's lung respiratory impedance, including: Acquire the transthoracic impedance of the target object; The cardiac activity impedance is removed from the transthoracic impedance to obtain the pulmonary respiratory impedance.

3. The readable storage medium according to claim 2, wherein: The step of removing the cardiac activity impedance from the transthoracic impedance to obtain the pulmonary respiratory impedance includes: The transthoracic impedance is subjected to bandpass filtering according to a preset cutoff frequency range to filter out the cardiac activity impedance, thereby obtaining the pulmonary respiratory impedance.

4. The readable storage medium according to claim 3, wherein: The preset cutoff frequency range is [0.05 Hz, 0.5 Hz].

5. The readable storage medium according to claim 2, wherein: The step of removing the cardiac activity impedance from the transthoracic impedance to obtain the pulmonary respiratory impedance includes: Acquire the cardiac activity impedance corresponding to the time series of the transthoracic impedance according to the pre-fitted cardiac activity impedance time series diagram; The pulmonary respiratory impedance is obtained according to the difference between the transthoracic impedance and the cardiac activity impedance of the corresponding time series.

6. The readable storage medium according to claim 5, wherein: The target object's cardiac activity impedance time series diagram is obtained by fitting the following steps: Acquiring a first transthoracic impedance and a second transthoracic impedance of the target object within the same ventricular activity cycle, wherein the first transthoracic impedance is the transthoracic impedance corresponding to the end of ventricular diastole, and the second transthoracic impedance is the transthoracic impedance corresponding to the end of ventricular systole; obtaining a cardiac activity impedance change amplitude of the target subject according to a difference between the first transthoracic impedance and the second transthoracic impedance; A linear fitting is performed according to the amplitude of the cardiac activity impedance change of the target object and the time sequence of the intracardiac potential diagram of the target object to obtain the cardiac activity impedance time sequence diagram of the target object.

7. The readable storage medium according to claim 6, wherein: The acquiring of the first transthoracic impedance and the second transthoracic impedance of the target object in the same ventricular activity cycle includes: When the apex of the R wave of the electrocardiogram signal of the target object is detected, obtaining a first transthoracic impedance of the target object; When a preset time interval is reached, a second transthoracic impedance of the target object is obtained.

8. The readable storage medium according to claim 7, wherein: The preset time interval is 180 milliseconds to 200 milliseconds.

9. The readable storage medium according to claim 1, wherein: When the computer program is executed by a processor, the following steps are further implemented: Creating a buffer capable of storing a preset number of absolute values ​​of lung respiratory impedance; Determining whether the total number of pulmonary respiratory impedances obtained so far is less than or equal to the preset number; If yes, then the absolute value of the currently acquired pulmonary respiratory impedance is stored in the buffer in order; If not, the absolute value of the pulmonary respiratory impedance stored first in the buffer is removed, and the absolute value of the pulmonary respiratory impedance currently obtained is stored in the tail position of the buffer.

10. The readable storage medium according to claim 9, wherein: When the computer program is executed by a processor, the following steps are further implemented: The sum of the absolute values ​​of the pulmonary respiratory impedance of the target object is calculated according to the absolute values ​​of the preset number of pulmonary respiratory impedances stored in the buffer.

11. The readable storage medium according to claim 1, wherein: The determining whether the target subject has an apnea event or a hypopnea event according to the sum of the absolute values ​​of the lung respiratory impedance of the target subject includes: Determining whether the sum of the absolute values ​​of the lung respiratory impedance of the target subject is less than or equal to a pre-acquired apnea impedance threshold, and if so, determining that an apnea event occurs in the target subject; If the sum of the absolute values ​​of the lung respiratory impedance of the target subject is greater than the apnea impedance threshold, it is determined whether the sum of the absolute values ​​of the lung respiratory impedance of the target subject is less than or equal to a pre-acquired hypopnea impedance threshold. If so, it is determined that a hypopnea event has occurred in the target subject.

12. The readable storage medium according to claim 11, wherein: The apnea impedance threshold and the hypopnea impedance threshold are obtained by the following steps: Obtaining the sum of absolute values ​​of the pulmonary respiratory impedance of the target subject in a resting state; Obtaining the apnea impedance threshold according to a first preset proportional coefficient and the sum of the absolute values ​​of the lung respiratory impedance of the target subject in a resting state; Obtaining the hypopnea impedance threshold according to a second preset proportional coefficient and the sum of the absolute values ​​of the lung respiratory impedance of the target subject in a resting state; The second preset proportional coefficient is greater than the first preset proportional coefficient.

13. The readable storage medium according to claim 12, wherein: The first preset proportional coefficient is 0.05-0.10, and the second preset proportional coefficient is 0.

50.

14. The readable storage medium according to claim 1, wherein When the computer program is executed by a processor, the following steps are further implemented: Whether the target subject has sleep apnea or not is determined based on the total number of apnea events and hypopnea events occurring in the target subject within a unit time.

15. An electronic device, characterized in that: The method comprises a processor and the readable storage medium according to any one of claims 1 to 14.

16. An implantable medical device, characterized in that: The implantable medical device comprises the readable storage medium according to any one of claims 1 to 14 or the electronic device according to claim 15 .

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