JP2016007243A - Apnea and/or infrequent respiration diagnostic device and apnea and/or infrequent respiration diagnostic method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apnea and/or infrequent respiration diagnostic device capable of diagnosing whether or not a user's respiratory state is an apnea and/or infrequent respiration state with a high degree of precision based on a biological signal detected during sleep noninvasively and with no restraints without using a blood oxygen saturation measuring instrument, etc. together.SOLUTION: An apnea and/or infrequent respiration diagnostic device includes a respiratory signal detection part 4 for detecting respiratory signals of a user noninvasively and with no restraints, a normalization part 8 for normalizing the respiratory signal by changing a gain of the respiratory signal based on a value of difference between the maximum value and the minimum value in the respiratory signal for a predetermined time of the respiratory signals detected by the respiratory signal detection part 4, and a respiratory state determination part 9 for determining whether or not the user is in an apnea and/or infrequent respiration state based on the normalized respiratory signal normalized by the normalization part 8.

Description

The present invention relates to an apnea and / or hypopnea diagnosis apparatus for diagnosing whether or not a breathing state of a user is apnea and / or hypopnea based on a biological signal detected non-invasively and unconstrained during sleep, and The present invention relates to an apnea and / or hypopnea diagnosis method.

In recent years, many symptoms such as sleepiness or loss of vitality due to falling into an apnea state and / or a hypopnea state during sleep have been reported. In particular, doze driving caused by sleep apnea syndrome and / or hypopnea syndrome (hereinafter collectively referred to as apnea syndrome) may cause social problems and cause serious situations. There is a growing need for treatment of diseases.

  Of the population over 10 years old in Japan, the number of people with insomnia or insomnia is estimated to be about 24 million, 20% of the population, of which about 2.4 million are 10% of those with apnea syndrome Has been.

The apnea state refers to a breath stop state of 10 seconds or more, and there is a case where a long breath stop state of 60 seconds continues. The hypopnea state refers to a state in which the state in which the amount of air taken in by respiration has decreased by 50% or more from the maximum amount of intake continues for 10 seconds or more. People with strong symptoms are said to have more than 30 apneas per hour. If the apnea / hypopnea index AHI is 5 or more, it is assumed that the patient has apnea syndrome. AHI = 5 means that five or more apnea / hypopnea situations occur per hour.

There are two types of causes of lost breathing. The first is an abnormality of the central nervous system, and the second is when the airway is blocked by the tongue. Of these, most of the causes of apnea syndrome are the second one, and the airway is often blocked by the tongue when shifting to a deep sleep state. As a result, it is impossible to shift to deep sleep, so that sufficient sleep cannot be obtained, and symptoms of feeling sleepy during the day occur. In addition, it is known that when the oxygen deficiency state continues due to an apnea state or a hypopnea state, the oxygen saturation in the blood tends to decrease by 4% or more.

Here, as a technique for determining the respiratory state at the time of sleep, there is a technique that combines the determination of the sleep state by so-called sleep polysomnograph (PSG) and the respiration measurement by attaching the expiratory flow rate measuring device to the nose outlet. Generally adopted. However, it has been pointed out that these methods are heavy on the user and may result in a result different from the normal sleep state. Other than the PSG method, a method for measuring the oxygen concentration in the blood and determining apnea and / or hypopnea based on changes in the amount of oxygen in the blood, and a device for recording chest and abdominal movements, etc. However, in any case, since the user is restrained, the burden on the user is large. In addition, these methods have a problem that measurement cannot be performed if the user moves greatly or the device is disconnected.

By the way, since the amplitude of the respiratory signal varies depending on the user, and the signal amplitude varies greatly depending on the sleep state, body movement, etc., in order to determine the apnea state and / or the hypopnea state. The respiratory signal needs to be properly normalized.

As a technique related to such normalization, as disclosed in Japanese Patent Application Laid-Open No. 2007-283030, a variance value for each predetermined period of a respiratory signal is calculated, and a respiratory state during sleep is calculated based on the normalized variance value. There is something to judge. Japanese Unexamined Patent Application Publication No. 2007-44331 describes a technique for generating normalized data when determining an apnea state based on blood oxygen concentration and pulse wave frequency analysis.

Furthermore, as a normalization method in an actual product, there is a method of measuring the flow rate of exhalation by inserting a nozzle into the nose and mouth of “SAS2100”, a class II medical device manufactured by Nihon Kohden. This apparatus sets the reference value of the respiration rate to a predetermined value, normalizes the signal amplitude at the time of a stable respiration waveform as 100, determines that the signal amplitude is 50% or less as a hypopnea state, and 10% or less. The case is determined to be apnea. However, this apparatus has a problem that the measurement accuracy greatly varies depending on the acquisition state of a respiratory waveform that is a stable reference for normalization. In addition, this apparatus has a problem that a large error occurs when the nozzle comes off during measurement or when mouth breathing occurs instead of nasal breathing.

Suzuken's class II medical device “SD-102” detects respiration using a number of pressure sensors, normalizes the respiration signal based on the stable time at the beginning of the measurement, and the signal amplitude is 50%. A method is adopted in which the following case is determined as a hypopnea state and the case of 10% or less is determined as an apnea state. However, even in this apparatus, there is a problem that the measurement accuracy greatly varies depending on the determination of a stable respiration waveform for normalization. For example, if the amplitude of the respiratory signal when the user is lying on the side is used as the standard for normalization, signals that deviate significantly from the standard are obtained due to changes in the user's body inclination, etc. May be.

As described above, in order to determine an apnea state and / or a hypopnea state, it is necessary to properly normalize the respiratory signal, but the reference signal amplitude for performing the normalization is not appropriately set. As long as the required accuracy is not obtained.

For example, when a respiratory signal is obtained when sleeping in an upside down state, a relatively large amplitude is obtained as shown in FIG. 1 in the first half of sleep, but in the middle sleep, the amplitude is as shown in FIG. In the late stage of sleep, the situation that the amplitude becomes minimum as shown in FIG. 3 frequently occurs. In addition, when a respiratory signal is obtained when sleeping in a sideways recumbent state, for example, as illustrated in FIG. 4, a respiratory signal having a smaller amplitude is generally obtained than when sleeping in a sideways recumbent state. When the sensitivity (gain) is further reduced, as shown in FIG. 5, a respiratory signal that changes with an amplitude smaller than the amplitude shown in FIG. 4 is obtained.

In such a state, when the signal amplitude serving as a reference for normalization, that is, the signal amplitude corresponding to the maximum intake amount of air by respiration is set uniquely, it is possible to appropriately determine the respiration state. It becomes extremely difficult. Since the technique described in the above-mentioned patent document and the method in the actual product are unclear or set uniquely as a reference for performing normalization, in practice, In many cases, it is determined that the amplitude of normal respiration is a low respiration value, and the respiration state cannot be appropriately determined based on the respiration signal. Therefore, conventionally, not only the respiratory signal but also the blood oxygen saturation meter is used together to determine the respiratory state.

The present invention has been made in view of such circumstances, and can be detected non-invasively and unconstrained during sleep without using a blood oxygen saturation meter or the like by employing an appropriate normalization technique. Apnea and / or hypopnea diagnosis device and apnea and / or hypopnea capable of accurately diagnosing whether the breathing state of the user is apnea and / or hypopnea based on the vital signs An object is to provide a diagnostic method.
Means for solving the problem

That is, the apnea and / or hypopnea diagnosis apparatus according to the present invention that achieves the above-described object is such that the respiratory state of the user is apnea and / or low based on a biological signal detected non-invasively and unconstrained during sleep. In an apnea and / or hypopnea diagnosis apparatus for diagnosing whether or not it is a breath, the breathing signal detection means for detecting the breathing signal of the user non-invasively and unconstrained, and the breathing signal detection means Normalizing means for normalizing the respiratory signal by changing a gain of the respiratory signal based on a difference value between a maximum value and a minimum value in the respiratory signal of a predetermined time among the respiratory signals, and the normalization Breathing state determination means for determining whether or not the user is in an apnea state and / or a hypopnea state based on a normalized respiratory signal normalized by the means. .

In addition, the apnea and / or hypopnea diagnosis method according to the present invention that achieves the above-described object is based on a biological signal detected non-invasively and unconstrained during sleep, and the respiratory state of the user is apnea and / or low. In an apnea and / or hypopnea diagnosis method for diagnosing whether or not breathing, a breathing signal detection step for detecting the breathing signal of the user non-invasively and unconstrained by predetermined breathing signal detection means, and signal processing A processor for performing the change of the gain of the respiratory signal based on a difference value between a maximum value and a minimum value in the respiratory signal of a predetermined time among the respiratory signals detected in the respiratory signal detection step, A normalization step of normalizing a respiratory signal; and the processor is in an apnea and / or hypopnea state based on the normalized respiratory signal normalized in the normalization step. Luke is characterized in that it comprises a whether determining respiratory condition determination step.

Such an apnea and / or hypopnea diagnosis apparatus and an apnea and / or hypopnea diagnosis method according to the present invention are based on only a respiratory signal detected non-invasively and unconstrained and when the condition is met, as needed. The normalization is performed by setting a reference for normalizing the respiration signal, that is, a signal amplitude corresponding to the maximum intake amount of air by respiration.

In the present invention, since normalization is performed by setting a standard for performing normalization of the respiration signal as needed based on only the respiration signal, without using a blood oxygen saturation meter or the like as in the past, Whether or not the user's breathing state is apnea and / or hypopnea can be diagnosed with high accuracy.

It is a figure which shows the example of the respiration signal of the sleep first period in the case of sleeping in the upward lying state. It is a figure which shows the example of the respiration signal of the middle sleep in the case of sleeping in the upward lying state. It is a figure which shows the example of the respiratory signal of a late sleep in the case of sleeping in an upward lying state. It is a figure which shows the example of the respiration signal in the case of sleeping in a sideways lying state. It is a figure which shows the example of the respiration signal at the time of a sensitivity fall in the case of sleeping in a sideways lying state. It is a figure which shows the structure of the apnea and / or hypopnea diagnosis apparatus shown as embodiment of this invention. It is a figure which shows the structure of the apnea and / or hypopnea diagnosis apparatus shown as embodiment of this invention, and is a partial cross section figure when it sees from the arrow direction in FIG. It is a figure which shows the example of a respiration signal and a heartbeat signal, and is a figure for demonstrating operation | movement of a body motion detection part. It is a figure which shows the timing of the respiration signal and the normalization respiration signal, and the gain control corresponding to this, and is a figure for demonstrating the example of normalization when a signal measurement is started. It is a figure which shows the timing of the respiration signal and the normalization respiration signal, and the gain control corresponding to this, and is a figure for demonstrating the example of normalization when a body motion is detected. It is a figure which shows the determination example of an apnea state, and is a figure which shows the determination result of the respiration state corresponding to this with a respiration signal, a normalization respiration signal, and a normalization difference value. It is a figure which shows the determination result of the respiration state corresponding to this with the respiration signal, the normalization respiration signal, and the normalization difference value, and is a figure for demonstrating the determination example of a low respiration state. It is a figure which shows the structure of another biological signal detection part.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings.

This embodiment is an apnea and / or hypopnea diagnostic apparatus that diagnoses whether or not a user's breathing state is apnea and / or hypopnea during sleep. In particular, the apnea and / or hypopnea diagnosis apparatus realizes a highly accurate diagnosis by performing appropriate normalization.

  FIG. 6 shows a configuration in which processing of the apnea and / or hypopnea diagnosis apparatus shown as an embodiment of the present invention is represented as a block, and FIG. 7 is a partial cross-sectional view when viewed from the direction of the arrow in FIG. Is shown. That is, the apnea and / or hypopnea diagnostic apparatus detects a biological signal of a user lying on the bed 21 and amplifies the biological signal detected by the biological signal detection unit 1. A signal amplifying unit 2, a filter unit 3 that performs a filtering process on the biological signal amplified by the signal amplifying unit 2, a respiratory signal detecting unit 4 that detects a respiratory signal that has passed through the filter unit 3, and a filter A heartbeat signal detection unit 5 that detects a heartbeat signal that has passed through the unit 3, a body movement detection unit 6 that detects a user's body movement based on the heartbeat signal detected by the heartbeat signal detection unit 5, and a heartbeat signal detection The sleep stage determination unit 7 for determining the sleep stage based on the heartbeat signal detected by the unit 5 and the respiratory signal detection unit 4 based on the body motion signal detected by the body motion detection unit 6 Comprising a normalizing unit 8 normalizes No. 吸信, and determining the breathing state determination unit 9 respiratory state of the user based on the normalized respiration signal obtained by the normalizing unit 8. Among these units, at least the respiratory signal detection unit 4, the heartbeat signal detection unit 5, the body motion detection unit 6, the sleep stage determination unit 7, the normalization unit 8, and the respiratory state determination unit 9 are, for example, signals A dedicated processor such as a DSP (Digital Processing Unit) that is implemented as a program that can be executed using hardware such as a CPU (Central Processing Unit) or memory in a computer that performs processing, or that is mounted on an expansion board that can be attached to the computer Or can be implemented using

The biological signal detection unit 1 is a non-invasive and unconstrained sensor that detects a minute biological signal of a user. Specifically, the biological signal detection unit 1 includes a pressure detection tube 1a and a minute differential pressure sensor 1b that is a sensor that detects minute pressure fluctuations in the air accommodated in the pressure detection tube 1a. Thus, a non-invasive and non-constrained biological signal detection means is configured.

As the pressure detection tube 1a, a tube having an appropriate elasticity so that the internal pressure fluctuates corresponding to the pressure fluctuation range of the biological signal is used. Further, as the pressure detection tube 1a, it is necessary to appropriately select the volume of the hollow portion of the tube in order to transmit the pressure change to the fine differential pressure sensor 1b at an appropriate response speed. When the pressure detection tube 1a cannot satisfy the appropriate elasticity and the volume of the hollow portion at the same time, the hollow portion of the pressure detection tube 1a is loaded with a core wire of an appropriate thickness over the entire length of the tube, and the volume of the hollow portion is set appropriately Can be taken.

  Such a pressure detection tube 1 a is disposed on a hard sheet 22 laid on the bed 21. In the apnea and / or hypopnea diagnosis apparatus, a cushion sheet 23 having elasticity is laid on the hard sheet 22, and the user lies on the pressure detection tube 1a. Note that the pressure detection tube 1a may be configured to be incorporated in the cushion sheet 23 or the like to stabilize the position of the pressure detection tube 1a.

The minute differential pressure sensor 1b is a sensor that detects minute fluctuations in pressure. In the present embodiment, a low-frequency condenser microphone type sensor is used as the fine differential pressure sensor 1b. However, the present invention is not limited to this, and any sensor having an appropriate resolution and dynamic range may be used. Good. The low-frequency condenser microphone used in the present embodiment is replaced with a general acoustic microphone that does not consider the low-frequency region, and a low-frequency region characteristic is provided by providing a chamber behind the pressure-receiving surface. Is significantly improved, and is suitable for detecting minute pressure fluctuations in the pressure detection tube 1a. In addition, this condenser microphone is excellent for measuring minute differential pressure, has a resolution of 0.2 Pa and a dynamic range of about 50 Pa, and is compared with a fine differential pressure sensor using a ceramic that is usually used. Therefore, it is suitable for detecting a minute pressure applied to the pressure detection tube 1a through a biological signal passing through the body surface. The frequency characteristic shows a substantially flat output value between 0.1 Hz and 30 Hz, and is suitable for detecting minute biological signals such as heartbeat and respiration.

In the present embodiment, two sets of pressure detection tubes 1a are provided so that one detects a biological signal of the user's chest region and the other detects the user's buttocks region. A biological signal is detected regardless of the person's sleeping posture. In the apnea and / or hypopnea diagnosis apparatus, the pressure detection tube 1a may be arranged only in one of the chest region and the buttocks region. The biological signal detected by such a biological signal detection unit 1 is supplied to the signal amplification unit 2. The apnea and / or hypopnea diagnosis apparatus can be easily used in daily life by adopting such a non-invasive and non-constrained configuration for detecting a biological signal, and is particularly suitable for use by the elderly. It is.

The signal amplification unit 2 amplifies the signal detected by the biological signal detection unit 1 so that it can be processed in a later processing step, and further performs an appropriate signal shaping process by removing a signal of an apparently abnormal level Do. The biological signal amplified by the signal amplifying unit 2 is supplied to the filter unit 3.

The filter unit 3 extracts a respiratory signal and a heartbeat signal by removing unnecessary signals from the biological signal amplified by the signal amplification unit 2 using a bandpass filter or the like. In other words, the biological signal detected by the biological signal detection unit 1 is a signal in which various vibrations emitted from the human body are mixed, and in addition to the respiratory signal and the heartbeat signal, various body movement signals such as a rollover signal are included. The signal is included. Among these, the respiratory signal is a signal in which a change in body movement based on the movement of the lungs is included in the biological signal as vibration. The heartbeat signal is a signal in which a change in pressure based on the pump function of the heart (that is, blood pressure) becomes a vibration and is included in the biological signal. In the apnea and / or hypopnea diagnosis apparatus, it is recognized by the filter unit 3 as a respiratory signal and a heartbeat signal. The respiratory signal and the heartbeat signal that have passed through the filter unit 3 are supplied to the respiratory signal detection unit 4 and the heartbeat signal detection unit 5, respectively. Note that the sampling period of the respiratory signal and the heartbeat signal is 4 milliseconds.

  The respiratory signal detection unit 4 detects the respiratory signal extracted by the filter unit 3. The respiratory signal composed of the time series waveform detected by the respiratory signal detection unit 4 is represented by the measured raw signal waveform, and the amplitude is not limited regardless of the sensitivity setting of the device at that time. is there. The respiration signal detection unit 4 supplies the detected respiration signal to the normalization unit 8.

  The heartbeat signal detection unit 5 detects the heartbeat signal extracted by the filter unit 3. The heartbeat signal composed of the time series waveform detected by the heartbeat signal detector 5 is represented by the measured raw signal waveform, and the amplitude is not limited regardless of the sensitivity setting of the device at that time. is there. The heartbeat signal detection unit 5 supplies the detected heartbeat signal to the body motion detection unit 6 and the sleep stage determination unit 7.

  Based on the heartbeat signal detected by the heartbeat signal detection unit 5, the body movement detection unit 6 detects the user's body movement such as when the user's body moves and the measurement position changes or the body position changes. To detect. For example, as shown in FIG. 8, when the measurement range of the heartbeat signal amplitude is from 0 to 1000, the body motion detection unit 6 has a state in which the heartbeat signal amplitude HL1 is a predetermined value (for example, 750) or more. When it continues for a predetermined time (for example, 3 seconds), it is determined that body movement has occurred. Note that the body motion detection method by the body motion detection unit 6 is not particularly limited. The body motion detection unit 6 supplies the detected body motion information to the normalization unit 8.

  The sleep stage determination unit 7 is based on the heartbeat signal detected by the heartbeat signal detection unit 5. The sleep stage of the user during sleep, that is, the awakening stage, the REM sleep stage, the first non-REM sleep stage, and the second The six types of the non-REM sleep stage (shallow non-REM sleep stage) and the third non-REM sleep stage and the fourth non-REM sleep stage (deep non-REM sleep stage) are determined. For example, the sleep stage determination unit 7 performs automatic gain control so that the heart rate signal detected by the heart rate signal detection unit 5 falls within a predetermined signal level range, and the gain of the gain control when the gain control is performed. The intensity of the heartbeat signal is calculated based on the value (coefficient), a dispersion value indicating the dispersion of the data for a predetermined time is calculated for the calculated signal intensity data, and the sleep stage is calculated based on the time series data of the dispersion value. Can be determined. The sleep stage determination unit 7 can also determine the sleep stage based on the time-series data of the electroencephalogram component ratio obtained based on the heartbeat signal detected by the heartbeat signal detection unit 5. In addition, the method described in Japanese Patent Application Laid-Open No. 2012-65853 by the present applicant may be applied. That is, the method for determining the sleep stage by the sleep stage determination unit 7 is not particularly limited. The sleep stage determination unit 7 supplies the determined sleep stage information to the respiratory state determination unit 9.

  The normalization unit 8 normalizes the respiration signal detected by the respiration signal detection unit 4 so that the amplitude falls within a predetermined measurement range. Specifically, the normalization unit 8 includes a difference value (amplitude of the respiration signal) between the maximum value and the minimum value in the respiration signal of a predetermined time (for example, 5 seconds) among the respiration signals detected by the respiration signal detection unit 4. The gain (sensitivity) is sufficiently increased so as to increase the value), and control is performed so that the gain (sensitivity) is less than the predetermined first threshold value. That is, since the normalization unit 8 generally has a small amplitude of the respiratory signal in the sideways lying state as shown in FIGS. 4 and 5, the respiratory signal for a predetermined time (for example, 5 seconds) in this state. When the gain (sensitivity) is increased sufficiently enough to saturate the difference value between the maximum value and the minimum value in the case, and a cycle in which the difference value is equal to or greater than a predetermined first threshold value occurs twice in succession. When the gain of the breathing signal is decreased by a predetermined value and the above operation is repeated, the difference value becomes less than the predetermined first threshold value, and the difference value becomes less than the first threshold value. Stops control. Then, the normalizing unit 8 normalizes the respiratory signal by setting the first threshold as 100%. In particular, the normalization unit 8 performs normalization when signal measurement is started, and thereafter performs normalization every time body motion is detected by the body motion detection unit 6. The normalization unit 8 determines the gain of the respiratory signal when a cycle in which the difference value is less than the predetermined second threshold value smaller than the first threshold value occurs twice in the gain control process. Is increased by a predetermined value to normalize the respiratory signal. That is, the normalizing unit 8 performs normalization by setting a reference for performing normalization of the respiration signal, that is, a signal amplitude corresponding to the maximum amount of air taken in by respiration, as needed, when necessary. The normalizing unit 8 supplies the normalized normalized respiratory signal to the respiratory state determining unit 9.

  The respiratory state determination unit 9 determines whether or not the user's respiratory state is an apnea state and / or a hypopnea state based on the normalized respiratory signal normalized by the normalization unit 9. The breathing state determination unit 9 outputs the determined breathing state information and displays it on a display device (not shown), prints it with a printing device, or stores it as data in a storage device. At this time, it is desirable that the respiratory state determination unit 9 records the determined respiratory state in association with the sleep stage determined by the sleep stage determination unit 7.

  Such an apnea and / or hypopnea diagnosis apparatus uses a biological signal detected by the biological signal detector 1 to amplify a biological signal detected by the signal amplifier 2 and a filter unit 3 to remove unnecessary signals from a bandpass filter or the like. To remove. Thereby, the respiration signal and the heartbeat signal that can be detected by the respiration signal detection unit 4 and the heartbeat signal detection unit 5 in the subsequent stage are extracted. Since the body motion signal is larger than the heartbeat signal, the heartbeat signal is a signal included in the body motion signal. In the apnea and / or hypopnea diagnosis apparatus, the respiratory signal is detected by the respiratory signal detector 4 and the heartbeat signal is detected by the heartbeat signal detector 5. The respiratory signal is normalized by the normalizing unit 8 and used for the determination of the respiratory state by the respiratory state determining unit 9. On the other hand, the heartbeat signal is used for detection of body movement by the body movement detection unit 6 and is used for determination of the sleep stage by the sleep stage determination unit 7.

  Here, normalization is required when the user enters the floor and starts signal measurement, when the user's body moves and the measurement position changes during sleep, and when the posture is upward and sideways. When it changes between. Of these, the latter two cases can be paraphrased as when the user's body movement is detected. Therefore, the apnea and / or hypopnea diagnostic apparatus performs normalization when the user enters the floor and starts signal measurement, and thereafter, every time a large body motion is detected by the body motion detector 6. Normalize to.

  First, normalization when signal measurement is started is performed as follows. That is, in the apnea and / or hypopnea diagnosis apparatus, the normalization unit 8 includes the maximum value and the minimum value in the respiration signal of a predetermined time (for example, 5 seconds) among the respiration signals detected by the respiration signal detection unit 4. Difference value Lmn is calculated, and normalization is performed by paying attention to the difference value Lmn.

  Specifically, when the measurement range of the amplitude of the respiratory signal is from 0 to 1000, the normalizing unit 8 calculates the maximum value and the minimum value of the respiratory signal for a predetermined time (for example, 5 seconds) in the lying-down state. The gain (sensitivity) is once increased so that the difference value Lmn exceeds 850 and is saturated. For example, the normalization unit 8 stores the minimum value of the gain of the respiratory signal, and increases the gain to about twice that to increase the gain (sensitivity) to the extent that the difference value Lmn is saturated. it can. Note that at the start of signal measurement (at the time of entering the floor), since the respiratory signal is generally always saturated, the difference value Lmn is rarely too small, and therefore there is no need to increase the gain (sensitivity). There are many cases. Then, the normalization unit 8 repeatedly performs control to gradually decrease the gain (sensitivity) of the respiratory signal by a predetermined value so that the difference value Lmn is less than a predetermined first threshold L1 (for example, 850). When the difference value Lmn becomes less than the first threshold value L1, the gain control is stopped (the gain is not changed). That is, the normalization unit 8 sets the gain of the respiratory signal so that the difference value Lmn does not exceed the first threshold value L1. And the normalization part 8 normalizes the waveform of a respiration signal to the waveform which fits 0 to 100% of a measurement range by setting a gain in this way.

  FIG. 9 shows the time series waveforms of the actual respiratory signal and the normalized respiratory signal, and the corresponding gain control timing. Regarding gain control, since the reciprocal of the gain is shown, the upper part of the vertical axis is the direction to decrease the gain, and the lower part of the vertical axis is the direction to increase the gain. As can be seen from the figure, the normalizing unit 8 can perform gain control according to the waveform amplitude of the respiratory signal, and obtain a normalized respiratory signal that falls within 0 to 100% of the measurement range.

  Also, normalization when detecting the user's body movement is performed as follows. That is, in the apnea and / or hypopnea diagnosis apparatus, the normalization unit 8 saturates when the difference value Lmn between the maximum value and the minimum value in the respiration signal for a predetermined time (for example, 5 seconds) in the sideways lying state exceeds 1000. The gain (sensitivity) is once increased to such an extent that the difference value Lmn is equal to or greater than the first threshold value L1 (Lmn ≧ L1), the gain of the respiratory signal is decreased by a predetermined value. The normalizing unit 8 repeatedly performs such control every predetermined time, and stops the gain control (does not change the gain) when the difference value Lmn becomes less than the first threshold value L1.

  FIG. 10 shows time series waveforms of actual respiratory signals and normalized respiratory signals including when body motion is detected, and the timing of gain control corresponding thereto. The figure also shows a time-series waveform of a heartbeat signal necessary for detecting body movement and a time-series waveform of a body movement signal based thereon. As can be seen from the figure, the normalization unit 8 detects body movement based on the heartbeat signal, stores the minimum value of the gain of the respiratory signal at that time, and increases the gain to about twice that value. Thus, when the gain (sensitivity) is increased to the extent that the difference value Lmn is saturated to increase the amplitude of the signal, and then the gain (sensitivity) of the respiratory signal is gradually decreased to the first threshold value, the normalization control is performed. Discontinue. Thereby, the normalization part 8 can obtain the normalization respiration signal which fits into 0 to 100% of a measurement range. In addition, when the pressure detection tube 1a of the biological signal detection unit 1 is provided so as to detect the displacement of the diaphragm of the user's chest, when the body moves and the measurement position changes or when the body position is upward. When it changes horizontally, the difference value Lmn becomes smaller. In particular, when the body position changes from upward to lateral, the body position becomes lateral after a large body movement has occurred. Therefore, the normalization unit 8 increases the gain after detecting this large body movement and increases the sensitivity. By setting to, normalization can be performed even in landscape orientation.

  In this way, the apnea and / or hypopnea diagnosis apparatus can perform normalization in any way. Note that the apnea and / or hypopnea diagnosis apparatus performs control so that the body movement detection process and the breathing state determination process are not performed during the normalization process.

  The apnea and / or hypopnea diagnosis apparatus determines whether or not the user is in an apnea state and / or a hypopnea state by the respiratory state determination unit 9 based on the normalized respiratory signal thus obtained. judge. At this time, the respiratory state determination unit 9 includes a difference value (normalized value) between the maximum value and the minimum value in the normalized respiratory signal for a predetermined time (for example, 5 seconds) among the normalized respiratory signals normalized by the normalizing unit 8. LNmn (referred to as a normalized difference value) is calculated, and the respiratory state is determined by paying attention to the normalized difference value LNmn. It should be noted that the control pitch and the determination pitch are handled separately when determining whether or not the patient is in an apnea state and / or a hypopnea state.

  Specifically, the breathing state determination unit 9 defines the apnea state as “the respiratory stop state for 10 seconds or more” and the hypopnea state as “the intake amount of air by breathing is 50% from the maximum intake amount. Based on the state where the state of being reduced by more than% continues for 10 seconds or more ", it is determined by the state of the normalized respiratory signal for 10 seconds. The respiratory state determination unit 9 calculates a normalized difference value LNmn for 10 seconds at a pitch of 1 second, and if this normalized difference value LNmn is 50% or less in the measurement range of 0 to 100%, When the normalization difference value LNmn is 10% or less, it is determined that the patient is in an apnea state. Then, after 10 seconds have elapsed as the calculation processing pitch of the next normalized difference value LNmn, the respiratory state determination unit 9 similarly determines the respiratory state by calculating the normalized difference value LNmn again at a 1-second pitch.

  FIG. 11 shows a time series waveform of an actual breathing signal, a normalized breathing signal, and a normalized difference value LNmn, and a corresponding breathing state determination result as an apnea determination example. FIG. 12 shows a time series waveform of an actual respiratory signal, a normalized respiratory signal, and a normalized difference value LNmn, and a corresponding respiratory state determination result as an example of determining a hypopnea state. Thus, the respiratory state determination unit 9 can determine the apnea state and / or the hypopnea state according to the amplitude of the normalized difference value LNmn.

  As described above, in the apnea and / or hypopnea diagnosis apparatus shown as an embodiment of the present invention, a reference for performing normalization of a respiratory signal is set as needed based on only the respiratory signal and appropriate normalization is performed. Therefore, it is possible to diagnose with high accuracy whether the breathing state of the user is apnea and / or hypopnea without using a blood oxygen saturation meter or the like as in the past. .

  The present invention is not limited to the embodiment described above.

  For example, in the above-described embodiment, as a method for detecting a biological signal, a method for extracting a respiratory signal or a heartbeat signal from a biological signal obtained by an unconstrained biological signal detection unit 1 laid under the user's body. However, the present invention is applicable to any detection means capable of continuously obtaining a respiratory signal, a heartbeat signal, or a signal equivalent thereto. In the present invention, the respiratory signal and the heartbeat signal may be detected separately instead of being extracted from the same biological signal. For example, the present invention is a heart rate monitor or a pulse meter of the type that is mounted on a body such as a wrist or an upper arm for a vibration system for measuring body motion while detecting a respiratory signal by the above-described method. You may make it detect using what can record data continuously.

  Further, as the biological signal detection unit 1, an air mat type detection unit as shown in FIG. 13 may be used instead of using the hollow tube described above. That is, the biological signal detection unit 30 shown in FIG. 13 is configured by connecting an air tube 30b to one end of an air mat 30a in which air is sealed, and further connecting a fine differential pressure sensor 30c to the air tube 30b. . In addition, the thing similar to what was demonstrated in the case of the biosignal detection part 1 using a hollow tube can be used for the micro differential pressure sensor 30c.

  Further, in the above-described embodiment, the body motion detection unit 6 has been described as detecting body motion based on the heartbeat signal detected by the heartbeat signal detection unit 5, but the present invention appropriately detects body motion. For example, body motion may be detected based on a biological signal before filtering detected by the biological signal detection unit 1.

Thus, it goes without saying that the present invention can be modified as appropriate without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 30 Living body signal detection part 1a Pressure detection tube 1b 30c Slight difference pressure sensor 2 Signal amplification part 3 Filter part 4 Respiration signal detection part 5 Heart rate signal detection part 6 Body motion detection part 7 Sleep stage determination part 8 Normalization part 9 Respiratory state Judgment part 21 Bed 22 Hard sheet 23 Cushion sheet 30a Air mat 30b Air tube

Claims (6)

In an apnea and / or hypopnea diagnosis apparatus for diagnosing whether a breathing state of a user is apnea and / or hypopnea based on a biological signal detected non-invasively and unconstrained during sleep,
Breathing signal detection means for detecting the breathing signal of the user non-invasively and unconstrained;
The respiratory signal is normalized by changing the gain of the respiratory signal based on a difference value between the maximum value and the minimum value of the respiratory signal of a predetermined time among the respiratory signals detected by the respiratory signal detection means. Normalization means to perform,
Breathing state determination means for determining whether or not the user is in an apnea state and / or a hypopnea state based on a normalized breathing signal normalized by the normalization unit. Apnea and / or hypopnea diagnostic device. Body movement detecting means for detecting the user's body movement,
The normalizing means increases the gain to a level that saturates the difference value in a sideways lying state when the body movement detection means detects the user's body movement, and the difference value is greater than or equal to a first threshold value. Decreasing the gain of the breathing signal by a predetermined value, repeating the operation, and stopping the control when the difference value is less than the first threshold, setting the first threshold as 100% and 2. The apnea and / or hypopnea diagnosis apparatus according to claim 1, wherein the respiratory signal is normalized. Since the normalization means includes a large signal such as body movement when the user enters the floor and starts signal measurement, the difference value becomes equal to or greater than the first threshold value. The breathing signal gain is decreased by a predetermined value, and the operation is repeated every predetermined time. When the difference value is less than the first threshold value, the control is stopped, and the first threshold value is set. The apnea and / or hypopnea diagnosis apparatus according to claim 2, wherein the respiration signal is normalized as 100%. The respiratory state determination means calculates a normalized difference value that is a difference value between a maximum value and a minimum value in a normalized respiratory signal for a predetermined time among the normalized respiratory signals normalized by the normalizing means, When the normalized difference value is 50% or less in the measurement range, it is determined that the patient is in a hypopnea state, and when the normalized difference value is 10% or less, the patient is in an apnea state. The apnea and / or hypopnea diagnosis apparatus according to claim 3, wherein the determination is made. Comprising a heartbeat signal detection means for detecting the user's heartbeat signal non-invasively and unconstrained;
The apnea and / or hypopnea diagnosis apparatus according to claim 2, wherein the body motion detection unit detects the user's body motion based on a heartbeat signal detected by the heartbeat signal detection unit. In an apnea and / or hypopnea diagnosis method for diagnosing whether or not the breathing state of a user is apnea and / or hypopnea based on a biological signal detected non-invasively and unconstrained during sleep,
A breathing signal detection step for detecting the breathing signal of the user non-invasively and unconstrained by a predetermined breathing signal detection means, and a processor for performing signal processing among the breathing signals detected in the breathing signal detection step, A normalization step of normalizing the respiratory signal by changing a gain of the respiratory signal based on a difference value between a maximum value and a minimum value in the respiratory signal for a predetermined time;
The processor includes a breathing state determination step of determining whether or not the user is in an apnea state and / or a hypopnea state based on the normalized breathing signal normalized in the normalization step. An apnea and / or hypopnea diagnosis method characterized by the above.