JP6013048B2 - Biological information analyzer - Google Patents

Description

  The present invention relates to a biological information analysis apparatus.

  Sleep Apnea Syndrome (SAS) is a disease that involves excessive somnolence during the day due to sleep disruption and causes 5 or 30 or 7/7 or more apneas that occur for 10 seconds or more during sleep. It is. Among the SASs, obstructive sleep apnea (OSA) is dominant in obstructive respiratory events, and central sleep apnea (CSA) is dominant in central respiratory events. be called. In the case of OSA, the upper airway is blocked during sleep and the airflow stops, but breathing movements of the chest wall and abdominal wall are also observed during that time. On the other hand, in CSA, irritation to respiratory muscles disappears during sleep and apnea occurs.

  Detection of respiratory effort is essential for SAS type determination. Currently, esophageal pressure measurement is required to measure respiratory effort, but esophageal pressure is measured with a pressure transducer by inserting a balloon catheter into the esophagus from the nose, or a silicone tube with a pressure sensor attached to the tip is taken from the nose. It must be inserted into the esophagus and measured, and it is not easy for engineers and nurses because it places a heavy burden on patients and requires skill in inserting catheters and tubes. Therefore, there is a need for a noninvasive respiratory effort measurement method that replaces esophageal pressure.

  As a method for measuring non-invasive breathing effort, a method using a breathing effort sensor of a type in which a belt is wound around the chest or abdomen is known. This is composed of a belt-like stretchable piezoelectric sensor (piezoelectric element), and the sensor expands and contracts according to the movement of the respiratory muscle of the subject and outputs a voltage from the piezoelectric element. By measuring this voltage on a polygraph, it is possible to observe the respiratory effort of the subject. Since such a conventional breathing effort sensor is worn by wrapping a belt around the chest or abdomen of the subject, there is a possibility of giving the subject a feeling of pressure or discomfort.

  On the other hand, the use of a suprasternal fistula pressure sensor can be considered as one that can more easily detect respiratory effort. Patent Document 1 discloses a technique for diagnosing upper airway resistance syndrome using an episternal fossa pressure sensor. Patent Document 1 further suggests that it is possible to perform SAS type determination using an episternal fossa pressure sensor.

JP 2005-224439 A

  However, at present, the suprasternal pressure sensor is only used as a visual indicator by waveform comparison in the SAS type determination, and an algorithm for automatically determining the SAS type using this sensor. Has not been established yet.

  Accordingly, an object of the present invention is to provide a technique for efficiently performing SAS type determination using an episternal fossa pressure sensor.

According to one aspect of the present invention, acquisition is performed using first acquisition means for acquiring information related to the subject's breathing and an upper sternal pressure sensor attached to the subject's suprasternal fossa. An apnea / hypopnea event indicating that the subject is in an apnea or a hypopnea based on the second acquisition means for acquiring information related to the movement of the chest wall and the information related to the breath And a type determination of sleep apnea syndrome for the apnea / hypopnea event based on information related to movement of the chest wall acquired using the detection means for detecting the suprasternal pressure sensor possess a determination means for performing said determination means, said at predetermined interval including the point at which apnea-hypopnea event is detected, the shake information relating to the movement of the chest wall of amplitude greater than the first threshold value Indicating that there is, and said apnea If the information related to the movement of the chest wall within the duration of the hypopnea event indicates that there is a swing with an amplitude greater than or equal to the second threshold, the apnea / hypopnea event is referred to as obstructive sleep apnea syndrome. It is determined that the biological information analyzing apparatus is characterized.

  ADVANTAGE OF THE INVENTION According to this invention, the type | mold determination of SAS can be performed efficiently using an sternum fossa pressure sensor.

The external appearance perspective view of the biological signal measuring device in an embodiment. The block diagram which shows the structural example of the biosignal measuring apparatus in embodiment. The figure which shows the example of mounting | wearing of the cannula in embodiment. The figure which shows the example of mounting | wearing of the sternum fossa part pressure sensor in embodiment. The figure explaining the concept of the type determination of SAS in an embodiment. The flowchart which shows the type determination process of SAS in embodiment. The figure explaining the shake detection of the suprasternal fossa in embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the following embodiment, It shows only the specific example advantageous for implementation of this invention. Moreover, not all combinations of features described in the following embodiments are indispensable for solving the problems of the present invention.

  FIG. 1 is an external perspective view showing a biological signal measuring apparatus 100 as an example of a biological information analyzing apparatus in the present embodiment. FIG. 2 is a block diagram showing a configuration example of the biological signal measuring apparatus 100 as an example of the biological information analyzing apparatus in the present embodiment. The biological signal measuring apparatus 100 has a configuration for directly acquiring biological information related to the breathing of the subject from the subject while being small and light so that it can be easily carried. However, in the present invention, a configuration for acquiring biological information related to respiration directly from the subject is not essential. The biological information analysis apparatus according to the present invention can acquire biological information related to respiration measured in advance by any method, for example, from a storage device or a storage medium connected directly or via a network. That's fine. Therefore, the function of the biological information analysis apparatus according to the present invention can be realized by a personal computer or the like.

  The biological signal measuring apparatus 100 has the small and light casing 8 as described above, and the battery lid 7 is formed on the casing 8. The display unit 1 includes a liquid crystal display (LCD), and displays setting contents, the state of each sensor signal, and the like. When the recording / enter switch 2 is pressed, recording is started. Further, during the setting period, this switch functions as an enter switch, and the setting item being set is determined. When the event switch 3 is pressed during recording, event information is recorded.

  Connected to the cannula connector 4 is a cannula 30 attached to a position close to the subject's nose and mouth. The cannula 30 is, for example, a nasal cannula, and is fixed using a surgical tape or the like with the nasal cavity tube inserted into the nostril of the subject as shown in FIG. Further, the cannula 30 may be a nasal cannula. In this case, as shown in FIG. 3B, the canal 30 is inserted in the nostril of the subject and the oral tube is in the mouth of the subject. It is fixed using surgical tape or the like so that it is slightly inside from the outside.

Connected to the SpO ₂ connector 5 is, for example, an SpO ₂ sensor 40 that is attached to the fingertip, earlobe, or forehead of the subject and indirectly detects the respiratory state based on the percutaneous arterial oxygen saturation (SpO ₂ ). The

  The analog connector 6 is connected to the suprasternal fossa pressure sensor 20. The suprasternal fistula pressure sensor 20 utilizes the fact that the movement of the chest wall is interlocked with the movement of the suprasternal fossa, and has, for example, a piezoelectric element and is attached to the subject's suprasternal fossa, An electrical signal indicating the pressure applied from the upper sternum fossa according to the movement of the upper sternum fossa (upper sternal pressure) is output. FIG. 4 shows an example of wearing of the suprasternal pressure sensor 20. As shown in the figure, the suprasternal fossa pressure sensor 20 is fixed to the subject's suprasternal fossa with a surgical tape 25 or the like. It will be clear that it is easier to wear than a type of breathing effort sensor that is worn by wrapping a belt around the chest or abdomen, and that it is difficult for the subject to feel pressure or discomfort.

  The electrical signal output from the suprasternal fossa pressure sensor 20 represents information related to the movement of the chest wall. Referring to FIG. 2, the electric signal is input to the amplifier 110 via the analog connector 6 and amplified there, and then is sampled at a predetermined sampling frequency and the number of bits by the A / D converter 120 and converted into digital data. Is done. Thus, information related to the movement of the subject's chest wall is acquired.

  The respiratory flow input to the cannula 30 is input to the respiratory flow sensor 112 via the cannula connector 4 and is converted into an electrical signal there. That is, the respiration flow sensor 112 directly detects respiration by a change in pressure or flow velocity of the subject's nose and mouth airflow. This electrical signal thus represents information relating to the air flow in the subject's nose and mouth. The electrical signal output from the respiratory flow sensor 112 is amplified by the amplifier 114, sampled by the A / D converter 116 at a predetermined sampling frequency and the number of bits, and converted into digital data. In this way, information related to the subject's breathing is acquired. Here, it is configured to acquire information related to the respiration of the subject using a respiratory flow sensor connected to a cannula that directly detects respiration by a change in pressure or flow velocity of the air flow in the nose and mouth. However, the present invention is not limited to this. For example, instead of or in addition to a cannula and respiratory flow sensor, a temperature sensor attached in close proximity to the nose and mouth to detect respiration by temperature and / or humidity changes in the air flow of the nose and mouth and It is good also as a structure which acquires the information relevant to a subject's respiration using a humidity sensor.

The electrical signal output from the SpO ₂ sensor 40 is input to the amplifier 118 via the SpO ₂ connector 5 and amplified there, and then is sampled by the A / D converter 119 at a predetermined sampling frequency and the number of bits. Converted to data. It is also possible to acquire this data as information related to the subject's breathing.

  The digital data output from the A / D converters 120, 116, and 119 are respectively input to the signal processing unit 130. The signal processing unit 130 performs signal processing such as predetermined filter processing and noise removal on these data. Each data subjected to signal processing is stored in the storage unit 150. The storage unit 150 can be constituted by, for example, a hard disk drive or a nonvolatile semiconductor memory. In order to facilitate data transfer to an external personal computer or the like, it may be configured with a removable semiconductor memory card. Hereinafter, data from the signal-processed suprasternal fistula pressure sensor 20 and the cannula 30 are referred to as “respiratory flow data” and “suprasternal pit data”, respectively.

  The control unit 140 includes, for example, a CPU, a ROM, and a RAM, and controls the overall operation of the apparatus by executing programs stored in the ROM or the storage unit 150 and controlling each unit.

  The operation unit 160 is a user interface including a recording / enter switch 2 and an event switch 3.

  The configuration of the biological signal measuring apparatus 100 in the present embodiment is generally as described above. Although sensors corresponding to various other measurement items (pulse rate, body position, body movement, etc.) can be connected, they are omitted here for the sake of simplicity.

When the suprasternal pressure sensor 20, the cannula 30, and the SpO ₂ sensor 40 are attached to a predetermined part of the subject and the recording / enter switch 2 is pressed, the biological signal measuring apparatus 100 starts measurement / recording. The control unit 140 sequentially writes the signal processed data in the storage unit 150 in association with the measurement time. These data can be recorded for 24 hours, for example.

  Next, the SAS type determination processing in the present embodiment will be described.

  Of sleep apnea syndrome (SAS), obstructive sleep apnea (OSA) is dominant in obstructive respiratory events, and central sleep apnea (OSP) is dominant in central respiratory events. Central sleep apnea (CSA). As shown in FIG. 5 (a), in the case of OSA, the upper respiratory tract is blocked during sleep, and mouth-and-nose breathing stops, but during that time, breathing exercises of the chest wall and abdominal wall are performed, so Swing is recognized. On the other hand, as shown in FIG. 5 (b), in CSA, the stimulus to the respiratory muscles disappears during sleep, so that the mouth-nose breathing stops and the suprasternal fovea does not shake, or Even a few. From this point of view, the SAS type determination in the present embodiment is performed by estimating the state of the suprasternal fovea in each apnea / hypopnea event.

  Before executing the SAS type determination process, in the measurement data analysis process, an apnea / hypopnea event indicating apnea or hypopnea state is detected from the entire measurement data. The detection process itself of the apnea / hypopnea event may be performed using a known method. For example, if the respiratory volume is lower than a predetermined value for a predetermined time or longer from the respiratory flow data, the apnea / hypopnea event is detected. Detected.

  The SAS type determination process is performed after the apnea / hypopnea event is detected in this manner. FIG. 6 is a flowchart showing the SAS type determination process using the suprasternal foveal data in the present embodiment. This SAS type determination process can be executed by a personal computer or the like that has received data transfer. But it is good also as a structure performed with the biosignal measuring apparatus 100 single-piece | unit.

  In S2, the upper sternal shake detection threshold Th is set to an initial value.

  Thereafter, the processes of S4 to S12 are repeated for the number of waveform samples of the suprasternal foveal data (loop 1).

  First, in S4, the amplitude of the target pair of waveform samples of the suprasternal foveal data is acquired. Here, the target pair refers to a pair of peaks (waveforms convex upward) and valleys (waveforms convex downward) at the target position of the waveform sample (the peaks and valleys are alternately present). Here, the amplitude means a difference (Peak-to-Peak) between a peak and a valley of the pair as shown in FIG. In S6, the amplitude acquired in S4 is compared with the shake detection threshold Th. Here, when the amplitude acquired in S4 exceeds the shake detection threshold Th, the process proceeds to S8, and this position is set as a position where the shake of the suprasternal fossa is detected (a) a detection position (sample number), Data of (b) amplitude value and (c) activity duration (see FIG. 7) is stored.

  Next, in S10, a value w · M obtained by multiplying the average value M of the amplitude for the past two minutes by a predetermined ratio w (for example, 0.25) is calculated, and this w · M and the current shake detection threshold Th And compare. If w · M exceeds the current shake detection threshold Th, the shake detection threshold Th is updated with the value of w · M in S12.

  When the processing of the above loop 1 is completed, the processing proceeds to S14, and whether or not there has been one or more suprasternal shake in loop 1, that is, if the amplitude exceeds the shake detection threshold Th in S6, at least once. Determines whether it has been determined. Here, when it is determined that there is no shake of the suprasternal fossa, it is estimated that the suprasternal fistula pressure sensor 20 is poorly mounted. Therefore, in this case, the process proceeds to S28, and a message indicating that the determination is impossible due to defective sensor mounting is displayed.

  On the other hand, if it is determined in S14 that one or more of the suprasternal fossa has been shaken, the processes in S16 to S26 are repeated for the number of apnea / hypopnea events (loop 2).

  First, in S16, it is determined whether or not there is a swing of the suprasternal fossa within N (for example, N = 10) seconds before and after the apnea / hypopnea event. If there is such a shake here, the process proceeds to S18.

  In S18, it is determined whether or not there is a swing of the suprasternal fovea having an amplitude equal to or greater than a predetermined suprasternal foveal motion threshold within the duration of the apnea / hypopnea event. Here, when there is a swing of the suprasternal fovea with an amplitude equal to or greater than the predetermined suprasternal foveal motion threshold, the apnea / hypopnea event is determined as obstructive sleep apnea (OSA) ( S20).

  If it is determined in S18 that there is no swing of the suprasternal fovea having an amplitude equal to or greater than the predetermined suprasternal foveal motion threshold within the duration of the apnea / hypopnea event, the process proceeds to S22.

  In S <b> 22, it is determined whether or not there is a section in which the swing of the suprasternal fossa is not longer than L (for example, L = 10) seconds within the duration of the apnea / hypopnea event. Here, if there is a section in which the suprasternal fovea does not run for more than L seconds within the duration of the apnea / hypopnea event, the apnea / hypopnea event is referred to as central sleep apnea (CSA). Determine (S24).

  If it is determined in S16 that there is no shake of the suprasternal fossa within N seconds before and after the apnea / hypopnea event, the apnea / hypopnea event is set as an undetermined event (S26). Similarly, if it is determined in S22 that there is no section in which the suprasternal fovea does not run for L seconds or more within the duration of the apnea / hypopnea event, the apnea / hypopnea event is determined as an undetermined event. (S26). In such a case, it is difficult to determine whether it is a closed type or a central type, and in order to prevent a determination error, “not determined” is used here.

  When the processing of the above loop 2 is completed, the SAS type determination processing in the present embodiment ends.

  The processing of this embodiment will be summarized.

  First, information related to the air flow of the subject's nose and oral cavity acquired using the respiratory flow sensor 112 from the cannula 30 attached to a position close to the subject's nose and mouth is input. In addition, information related to the movement of the chest wall acquired using the suprasternal fossa pressure sensor 20 attached to the subject's suprasternal fossa is input. Next, apnea / hypopnea indicating that the subject is in an apnea or hypopnea based on information related to the air flow of the subject's nose and mouth obtained using the respiratory flow sensor 112 An event is detected. Thereafter, SAS type determination is performed on the detected apnea / hypopnea event based on the information related to the movement of the chest wall acquired by using the suprasternal pressure sensor 20.

  With the above processing, SAS type determination can be performed efficiently using the suprasternal fossa pressure sensor.

Claims (6)

First acquisition means for acquiring information relating to breathing of the subject;
Second acquisition means for acquiring information related to movement of the chest wall acquired using an episternal pressure sensor attached to the subject's episternal fossa;
Detection means for detecting an apnea / hypopnea event indicating that the subject is in an apnea or a hypopnea based on information related to the breath;
Based on information related to the movement of the chest wall acquired using the suprasternal pressure sensor, a determination unit that performs sleep apnea syndrome type determination for the apnea / hypopnea event,
I have a,
The determination means includes
In a predetermined section including the time point when the apnea / hypopnea event is detected, the information related to the movement of the chest wall indicates that there is a swing with an amplitude greater than or equal to a first threshold; and
If the information related to the movement of the chest wall indicates that there is a swing with an amplitude greater than or equal to a second threshold within the duration of the apnea / hypopnea event,
A biological information analysis apparatus characterized by determining the apnea / hypopnea event as obstructive sleep apnea syndrome . Information related to the subject's breathing is:
A respiratory flow sensor connected to a cannula attached in close proximity to the subject's nose and mouth for detecting respiration by a change in pressure and / or a change in airflow in the subject's nose and mouth;
A temperature sensor and / or a humidity sensor, which is attached close to the subject's nose and mouth, and detects respiration by temperature change and / or humidity change of the subject's nose and mouth airflow;
SpO ₂ sensor, which is attached to the subject's fingertip or earlobe or forehead and detects the state of breathing based on arterial oxygen saturation,
The biological information analysis apparatus according to claim 1, wherein the biological information analysis apparatus is information obtained from at least one of the information. The determination means further includes:
In the given period before Symbol apnea-hypopnea event includes when it is detected, in case information related to the movement of the chest wall indicates that there is deflection of amplitude greater than the first threshold value, and,
Within the duration of the previous SL apnea-hypopnea event it does not indicate that information relating to the movement of the chest wall there is a deflection of amplitude greater than the second threshold value, and,
Within those the duration, indicating that the information related to the movement of the chest wall is the first threshold value or more amplitude interval deflection is not more than a predetermined time of the present,
Biological information analysis apparatus according to the apnea-hypopnea events to claim 1 or 2, characterized in that determining a central sleep apnea syndrome. The determination means further includes:
In the given period before Symbol apnea-hypopnea event includes when it is detected, indicating that the information relating to the movement of the chest wall there is no deflection of amplitude greater than the first threshold value, the apnea The biological information analysis apparatus according to claim 3 , wherein the hypopnea event is an undetermined event. The determination means further includes:
In the given period before Symbol apnea-hypopnea event includes when it is detected, in case information related to the movement of the chest wall indicates that there is deflection of amplitude greater than the first threshold value, and,
Within the duration of the previous SL apnea-hypopnea events, it indicates that information related to the movement of the chest wall there is no deflection of amplitude greater than the second threshold value, and,
Within those the duration, if you indicate that the information relating to the movement of the chest wall vibration of amplitude greater than the first threshold value does not exist the predetermined hours or more without interval,
The biological information analysis apparatus according to claim 4 , wherein the apnea / hypopnea event is the undetermined event. The suprasternal pressure sensor determines that the information regarding the movement of the chest wall does not have an amplitude greater than or equal to the first threshold throughout the entire input section, and that the suprasternal pressure sensor determines that the information is poorly mounted. Item 6. The biological information analysis apparatus according to any one of Items 1 to 5 .

Images