JP2017074190A - Respiration measuring device, respiration measuring method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a respiration measuring device, a respiration measuring method, and a program useful for examining a sleep apnea syndrome.SOLUTION: A respiration measuring device is provided which is used by attaching its attaching surface to a body surface of a user. The respiration measuring device includes first detection means, second detection means, and determination means. The first detection means detects an intracorporeal sound of the user generated with the respiration. The second detection means detects that the attaching surface is not attached firmly to the body surface. The determination means determines the presence or absence of the respiration of the user based on the result of the detection by the first detection means and the result of the detection by the second detection means.SELECTED DRAWING: Figure 9

Description

  Embodiments described herein relate generally to a respiratory measurement device, a respiratory measurement method, and a program.

  In recent years, sleep apnea syndrome is known as a disease that repeatedly stops breathing during sleep. This sleep apnea syndrome can be a major risk factor for various diseases such as stroke and myocardial infarction as well as subjective symptoms such as daytime sleepiness. For this reason, early detection and early treatment of sleep apnea syndrome are desired.

  Although the number of potential patients with sleep apnea syndrome is estimated to reach 2 million in Japan alone, the actual number of patients who are actually receiving treatment is small.

  One reason for this is, for example, that the examination for sleep apnea syndrome is complicated. In general tests for sleep apnea syndrome, it is necessary to attach a cannulated airflow sensor to the nose and mouth of the patient undergoing the test in order to confirm the presence or absence of breathing during sleep. Very annoying for me.

  On the other hand, it is known that when a person breathes, a sound of air flowing through the trachea in the chest (hereinafter referred to as breathing sound) is generated. This breathing sound can be heard using, for example, a stethoscope.

  Therefore, if a stethoscope-type device (respiration measurement device) is attached to the chest of a sleeping patient, the presence or absence of breathing (sound) can be determined. Examination (diagnosis) of apnea syndrome can be performed.

  In order to perform measurement all night, the respiratory measurement device needs to be attached to the chest of a sleeping patient using, for example, an adhesive double-sided adhesive tape or gel pad.

Japanese Utility Model Publication No. 58-101609

  However, when a double-sided adhesive tape or gel pad is used, a gap is generated between the respiratory measurement device and the patient's body surface according to the posture and body movement of the patient during sleep (that is, the respiratory measurement device). May not be in close contact with the patient's body surface). When the respiratory measurement device is not in close contact with the patient's body surface in this way, it is determined that there is no patient's breathing sound even when the patient is breathing due to a decrease in sound collection performance of the respiratory measurement device. May be.

  Therefore, when it is determined that there is no breathing sound in the respiratory measurement device, the determination result is actually due to the patient's breathing stop or because the respiratory measurement device is not in close contact with the patient's body surface A mechanism for distinguishing whether or not Without such a mechanism, the respiratory measurement device cannot accurately determine whether or not the patient is breathing, and cannot be said to be useful for testing sleep apnea syndrome.

  Therefore, a problem to be solved by the present invention is to provide a respiration measurement device, a respiration measurement method, and a program that are useful for testing sleep apnea syndrome.

  According to the embodiment, there is provided a respiratory measurement device that is used by mounting the mounting surface on the body surface of the user. The respiratory measurement device includes first detection means, second detection means, and determination means. The first detection means detects a body sound of the user that is generated along with breathing. The second detection means detects that the mounting surface is not in close contact with the body surface. The determination unit determines whether or not the user is breathing based on a detection result by the first detection unit and a detection result by the second detection unit.

The figure which shows an example of the usage condition of the respiration measuring apparatus which concerns on 1st Embodiment. The figure which shows an example of the external appearance of a respiration measuring apparatus. The figure for demonstrating an example of the structure for affixing a respiration measurement apparatus on a user's body surface. The figure which shows an example of the cross section of a respiration measuring apparatus. The figure for demonstrating the respiration measuring device of the state with which the user is mounted | worn. The figure for demonstrating the respiration measuring device of the state with which the user is mounted | worn. The figure for demonstrating the case where the light irradiated from the light source permeate | transmits skin. The block diagram which shows an example of a function structure of a respiration measuring apparatus. The flowchart which shows an example of the process sequence of a respiration measuring apparatus. The figure which shows the determination result stored in the storage part in time series order. The flowchart which shows an example of the process sequence of a respiratory sound determination process. The figure for demonstrating the case where the position where a light source is arrange | positioned is changed. The figure for demonstrating the case where the position where a photodetector is arrange | positioned is changed. The block diagram which shows an example of a function structure of the respiration measuring apparatus which concerns on 2nd Embodiment. The flowchart which shows an example of the process sequence of a respiration measuring apparatus. The figure which shows an example of the cross section of the respiration measuring apparatus which concerns on 3rd Embodiment. The block diagram which shows an example of a function structure of a respiration measuring apparatus. The figure which represents typically the time series signal of the intensity | strength of the light detected by the photodetector. The figure which shows an example of the cross section of the respiration measuring apparatus which concerns on the modification of 3rd Embodiment. The figure for demonstrating the principle which extracts a pulse wave component with a high S / N ratio. The flowchart which shows an example of the process sequence of the respiration measuring device at the time of extracting pulse wave information.

  Hereinafter, each embodiment will be described with reference to the drawings.

(First embodiment)
FIG. 1 shows an example of usage of the respiratory measurement device according to the first embodiment. A respiratory measurement device 10 shown in FIG. 1 is a small, light, and thin device used for testing sleep apnea syndrome, for example, to determine the presence or absence (breathing state) of a user's breathing during sleep. Used by being attached to the user. Specifically, as shown in FIG. 1, the respiratory measurement device 10 is used by, for example, mounting the mounting surface of the respiratory measurement device 10 on the chest of a user who is sleeping or the like (the body surface). Specifically, it is used by pasting on the chest of the user.

  FIG. 2 is a perspective view of the appearance of the respiratory measurement device 10. As shown in FIG. 2, the respiratory measurement device 10 (the housing thereof) has a thick disk shape so that it can be easily mounted near the center of the chest of the user. Note that the mounting surface 10a of the respiratory measurement device 10 is formed of a diaphragm similar to a stethoscope, for example. The diaphragm is, for example, a glass epoxy resin film (elastic thin film), and has a transparent or translucent light transmittance.

  In addition, the mounting surface 10a of the respiration measuring device 10 is attached to the body surface of the sleeping user via an adhesive double-sided adhesive tape 20 disposed along the edge of the mounting surface 10a, for example, as shown in FIG. It is pasted. A gel pad or the like may be used instead of the double-sided adhesive tape 20 as long as the mounting surface 10a of the respiratory measurement device 10 can be attached to the user's body surface.

  FIG. 4 is a cross-sectional view of the respiratory measurement device 10. As shown in FIG. 4, a sound collection member 10 b, a microphone 10 c, a light source 10 d, and a photodetector 10 e are arranged inside the respiratory measurement device 10 (the housing).

  The sound collecting member 10b has a mortar-like shape and has a function of collecting the body sound of the user via the mounting surface (diaphragm) 10a. The body sound of the user collected by the sound collection member 10b includes sound generated with the user's breathing. Note that the sound collecting member 10b is configured to have sufficient light shielding properties, for example, by being formed of a light shielding material or by coating the surface with a light shielding material or the like. Due to the sound collecting member 10b (that is, the light shielding member), the inside of the respiration measuring device 10 includes a space (that is, a space inside the sound collecting member 10b) 31 that includes the mounting surface 10a and a space that does not include the mounting surface 10a ( That is, it is divided into a space 32) outside the sound collecting member 10b.

  The microphone 10c is disposed, for example, near the center of the inside of the sound collecting member 10b so as to detect (measure) the user's internal sound collected by the sound collecting member 10b. As the microphone 10c, for example, a small microphone of MEMS (Micro Electro Mechanical Systems) type can be used.

  The light source 10d includes, for example, a light emitting diode configured to emit light. The light source 10d is disposed, for example, inside the sound collecting member 10b (that is, in the space 31). It is assumed that the light source 10d is configured to emit light after being modulated at a predetermined frequency (that is, to emit light modulated at the frequency).

  As shown in FIG. 4, a light transmission window 10 f that transmits light is provided in at least a part of the casing (outer wall) of the respiratory measurement device 10 that forms the space 32 described above.

  The photodetector 10e is disposed outside the sound collection member 10b (that is, in the space 32) and includes, for example, a photodiode and a current-voltage circuit. Thereby, the photodetector 10e can detect light (intensity) that enters the respiration measuring device 10 through the light transmission window 10f. The photodetector 10e further includes a bandpass filter, and selectively detects light (a signal having a predetermined frequency) emitted from the light source 10d.

  The microphone 10c, the light source 10d, and the light detection unit 10e described above are mounted on, for example, the printed circuit board 10g in the respiration measurement device 10.

  Next, with reference to FIG.5 and FIG.6, the respiration measuring apparatus 10 of the state mounted | worn with the user (that is, the mounting surface 10a is affixed on the user's body surface) is demonstrated.

  Here, as described above, the mounting surface 10a of the respiratory measurement device 10 is attached to the body surface 41 of the user. For this reason, for example, when the respiratory measurement device 10 is attached to a sleeping user, the respiratory measurement device 10 is covered with a clothing 42 (for example, a nightclothes) worn by the user.

  As shown in FIG. 5, the mounting surface 10 a of the respiratory measurement device 10 is appropriately attached to the user's body surface 41 (that is, the mounting surface 10 a is in close contact with the user's body surface 41). In this case, the light emitted from the light source 10d does not leak from the mounting surface 10a side. In addition, since the light source 10d is arranged inside the sound collecting member 10b having light shielding properties (that is, in the space 31), the light emitted from the light source 10d does not directly enter the space 32.

  That is, when the mounting surface 10a of the respiratory measurement device 10 is appropriately attached to the body surface 41 of the user, the photodetector 10e disposed in the space 32 detects the light emitted from the light source 10d. Never do.

  On the other hand, in this embodiment, the mounting surface 10a of the respiratory measurement device 10 is attached to the body surface 41 of the sleeping user via the double-sided adhesive tape 20 as described above. For this reason, depending on the posture and body movement of the user during sleep, there may be a gap between the wearing surface 10a of the respiratory measurement device 10 and the user's body surface 41 as shown in FIG.

  In this case, the light emitted from the light source 10d does not directly enter the space 32, but leaks to the outside of the respiratory measurement device 10 through a gap formed between the mounting surface 10a and the body surface 41 (that is, Pass through the gap). For example, as shown in FIG. 6, this light (leakage light) 43 is reflected by the user's body surface 41, clothing 42, and the like, so that it passes through the light transmission window 10f and reaches the photodetector 10e. .

  Accordingly, in the present embodiment, the light source 10d and the photodetector 10e have the mounting surface 10a not in close contact with the body surface 41 (that is, a gap is generated between the mounting surface 10a and the body surface 41). It functions as a detection unit that detects. That is, by detecting the light (leakage light) 43 emitted from the light source 10d by the light detector 10e, it can be detected that the wearing surface 10a of the respiratory measurement device 10 is not in close contact with the body surface 41 of the user. it can.

  As shown in FIG. 7, for example, when light emitted from the light source 10d passes through the skin, the mounting surface 10a of the respiratory measurement device 10 is in close contact with the body surface 41 of the user. In some cases, light is detected by the photodetector 10e. Therefore, in order to suppress the transmission of light emitted from the light source 10d to the skin, the wavelength of the light emitted from the light source 10d is preferably 600 nm or less, for example.

  FIG. 8 is a block diagram showing a functional configuration of the respiratory measurement device 10. As shown in FIG. 8, the respiratory measurement device 10 includes a first acquisition unit 11, a first determination unit 12, a second acquisition unit 13, a second determination unit 14, a third determination unit 15, and a storage unit 16.

  In the present embodiment, a part or all of the first acquisition unit 11, the first determination unit 12, the second acquisition unit 13, the second determination unit 14, and the third determination unit 15 are, for example, a CPU provided in the respiratory measurement device 10. It is assumed that the program is executed by a computer, that is, realized by software. Part or all of these units 11 to 15 may be realized by hardware such as an IC (Integrated Circuit), or may be realized as a combined configuration of software and hardware. Note that the program to be executed by the computer may be stored and distributed in a computer-readable storage medium, or may be downloaded to the respiratory measurement device 10 through a network.

  Moreover, in this embodiment, the storage part 16 shall be stored in the memory | storage device with which the respiration measurement apparatus 10 is equipped.

  The first acquisition unit 11 acquires a sound signal representing a user's internal sound detected by the microphone 10c.

  Based on the sound signal acquired by the first acquisition unit 11, the first determination unit 12 determines the presence / absence of a user's body sound (a breathing sound generated with breathing).

  The second acquisition unit 13 acquires an optical signal representing the intensity of the light detected by the photodetector 10e.

  Based on the optical signal acquired by the second acquisition unit 13, the second determination unit 14 has the mounting surface 10a of the respiratory measurement device 10 in close contact with the body surface 41 of the user (that is, the mounting surface 10a and the user Whether or not there is a gap between the body surface 41 and the body surface 41).

  Based on the determination result by the first determination unit 12 (that is, the detection result by the microphone 10c) and the determination result by the second determination unit 14 (that is, the detection result by the photodetector 10e), the third determination unit 15 Determine if there is breathing. The determination result by the third determination unit 15 is stored in, for example, the storage unit 16.

  Next, the processing procedure of the respiratory measurement device 10 will be described with reference to the flowchart of FIG.

  In the present embodiment, the microphone 10c detects sound collected by the sound collection member 10b while the user wears the respiration measurement device 10 (that is, while the respiration measurement device 10 is operating). Similarly, the photodetector 10e detects light that enters the respiratory measurement device 10 through the light transmission window 10f while the user wears the respiratory measurement device 10. In the present embodiment, it is assumed that the light source 10d is always lit while the user wears the respiratory measurement device 10.

  First, the first acquisition unit 11 and the second acquisition unit 13 acquire a sound signal that represents the sound detected by the microphone 10c and an optical signal that represents the intensity of light detected by the photodetector 10e (step S1). In this case, the 1st acquisition part 11 and the 2nd acquisition part 13 acquire the sound signal and optical signal of a predetermined period. The sound signal acquired by the first acquisition unit 11 is stored in a memory (not shown) inside the first determination unit 12. Further, the optical signal acquired by the second acquisition unit 13 is stored in a memory (not shown) inside the second determination unit 14.

  Next, the first determination unit 12 determines whether or not there is a respiratory sound based on a sound signal (a sound signal of a predetermined period) stored in a memory inside the first determination unit 12 (hereinafter referred to as a “respiratory sound”). , Written as breathing sound determination processing) (step S2). Details of this breathing sound determination process will be described later. The determination result by the first determination unit 12 is stored in a memory (not shown) inside the third determination unit 15.

  When the process of step S2 is executed, the second determination unit 14 determines the respiratory measurement device based on an optical signal (an optical signal of a predetermined period) stored in a memory inside the second determination unit 14. It is determined whether the 10 mounting surfaces 10a are in close contact with the user's body surface 41 (step S3).

  Here, as described in FIGS. 5 and 6 described above, in the present embodiment, when the mounting surface 10a is in close contact with the body surface 41, no light is detected by the photodetector 10e. On the other hand, when the mounting surface 10a is not in close contact with the body surface 41, light is detected by the photodetector 10e. For this reason, if light is detected by the photodetector 10e, it is determined that the mounting surface 10a is not in close contact with the body surface 41. If no light is detected by the photodetector 10e, the mounting surface 10a is determined to be the body surface. 41 can be determined to be in close contact.

  However, the photodetector 10e may be affected by external light or noise. For this reason, in the present embodiment, the mounting surface 10a is in close contact with the body surface 41 when the intensity of light indicated by the optical signal in the predetermined period is equal to or greater than a predetermined value (threshold value). It shall be determined that it is not. As described above, the influence of external light or noise can be reduced by selectively detecting light emitted from the light source 10d using a bandpass filter. Note that the determination result by the second determination unit 14 is stored in a memory inside the third determination unit 15.

  Next, based on the determination result by the first determination unit 12 and the determination result by the second determination unit 14, the third determination unit 15 performs the user's breathing during the period in which the sound signal and the optical signal are acquired in step S <b> 1 described above. Is determined (step S4).

  Here, the first determination unit 12 determines that there is no breathing sound (that is, no respiratory sound is detected by the microphone 10c), and the second determination unit 14 determines that the wearing surface 10a of the respiratory measurement device 10 is the body of the user. Assume that it is determined that the surface 41 is in close contact (that is, it is not detected that the surface 41 is not in close contact). In this case, the respiratory measurement device 10 is in a state where it can detect a respiratory sound (that is, there is no gap between the mounting surface 10a of the respiratory measurement device 10 and the body surface 41 of the user). Since the breathing sound is not detected, the third determination unit 15 determines that there is no user breathing.

  On the other hand, it is assumed that the first determination unit 12 determines that there is no breathing sound, and the second determination unit 14 determines that the wearing surface 10a of the respiratory measurement device 10 is not in close contact with the body surface 41 of the user. To do. In this case, the respiration measurement device 10 is not in a state where it can detect respiration sound (that is, there is a gap between the wearing surface 10a of the respiration measurement device 10 and the body surface 41 of the user), and thus the respiration sound is not generated. Since there is a possibility that it has not been detected, the third determination unit 15 determines that there is a user's breathing.

  If the first determination unit 12 determines that there is a breathing sound, the third determination unit 15 determines that there is a user's breathing regardless of the determination result by the second determination unit 14.

  The determination result in step S4 described above is stored in the storage unit 16 (step S5).

  Next, it is determined whether or not the operation of the respiratory measurement device 10 (respiration measurement) is to be terminated (step S6). In step S6, for example, when an operation such as turning off the power of the respiratory measurement device 10 is performed or when a preset end time is reached, it is determined that the operation of the respiratory measurement device 10 is finished.

  When it is determined that the operation of the respiratory measurement device 10 is to be ended (YES in step S6), the process is ended. On the other hand, when it determines with not complete | finishing operation | movement of the respiration measuring apparatus 10 (NO of step S6), it returns to step S1 and a process is repeated. That is, the process shown in FIG. 9 is repeatedly executed during the user's sleep unless it is determined in step S6 that the operation of the respiratory measurement device 10 is to be terminated.

  Here, FIG. 10 shows the determination results (presence / absence of user's breathing) stored in the storage unit 16 by repeatedly executing the process shown in FIG. 9 in time series. In FIG. 10, 1 indicates a determination result determined that there is a user's breathing, and 0 indicates a determination result determined that there is no user's breathing.

  According to the example shown in FIG. 10, it is easily recognized that the period T determined that the user does not breathe for a predetermined time or longer (for example, 10 seconds or longer) is a period in which the user is in an apnea state. be able to.

  Accordingly, the determination result (whether or not the user breathes) stored in the storage unit 16 by the process shown in FIG. 9 can be used for a sleep apnea syndrome test or the like.

  In the present embodiment, the determination result is output as binary values of “Yes” and “None” of the user's breath. However, the determination result includes, for example, “Yes”, “No. “No” and “None (however, the mounting surface 10a may not be in close contact with the body surface 41)” may be output.

  Further, the process shown in FIG. 9 may be executed in real time for each of the above-described predetermined periods, for example, by accumulating sound signals and optical signals acquired during the user's sleep, It may be executed during the time period.

  Next, with reference to the flowchart of FIG. 11, the processing procedure of the above-described breathing sound determination processing (step S2 shown in FIG. 9) will be described. At the start of this breathing sound determination process, as described above, the sound signal of a predetermined period is stored in the memory inside the first determination unit 12.

First, when the amplitude of the sound signal stored in the internal memory of the first determination unit 12 at time t is S (t), the first determination unit 12 has the S (t) (waveform represented by). Are divided into a plurality of sections having a certain time width, and frequency analysis (FFT) is performed on the sections (step S11). Hereinafter, for example, the energy of the frequency f [Hz] component of the _i- th section (i is an integer of 1 or more) obtained by this frequency analysis is expressed as P _i (f).

Next, the first determination unit 12 calculates energy for each of a plurality of predetermined frequency bands (step S12). Specifically, for each P _i (f), an integral value BP _i (j) for each band is calculated by the following equation (1).

Here, F _j represents the j-th frequency band. For example, if it is divided into J frequency bands, a J-dimensional vector BP _i is obtained by the above-described equation (1).

Next, for BP _i obtained by Expression (1), the first determination unit 12 identifies whether or not the sound signal in the i-th section (hereinafter referred to as section i) represents a respiratory sound. Is performed (step S13). This identification is performed by using a general classifier such as LDA (Linear Discriminant Analysis) or SVM (Support Vector Machine). Thereby, it is possible to obtain an identification result as to whether or not a sound having a high possibility of being a breathing sound is detected for the section i.

  By the above-described processing, the first determination unit 12 can obtain the presence / absence (identification result) of the breathing sound in each section, and thus can determine the section without the breathing sound, for example (step S14).

  Note that the above-described respiratory sound determination process shown in FIG. 11 is an example, and other processes may be executed as long as it is possible to determine the presence or absence of a respiratory sound.

  As described above, in the present embodiment, the detection result of the user's internal sound (breathing sound) generated by breathing by the microphone 10c (first detection unit), the light source 10d and the light detector 10e (second detection unit). Based on the detection result that the mounting surface 10a of the respiratory measurement device 10 is not in close contact with the body surface 41 of the user, the presence or absence of the user's breathing is determined. Specifically, if no breathing sound is detected and it is not detected that the wearing surface 10a is not in close contact with the body surface 41, it is determined that there is no breathing by the user. In the present embodiment, even if it is determined that there is no breathing sound by such a configuration, the determination result is actually due to the user's breathing stop or the mounting surface 10a of the respiratory measurement device 10 Can be determined whether or not the user is breathing in consideration of whether or not the user is in close contact with the body surface 41 of the user. In other words, in this embodiment, it can be avoided that the user's breathing sound is not detected despite the state in which the user's breathing sound is not properly detected. It can be said that it is useful for inspection.

  Note that the respiratory measurement device 10 according to the present embodiment has the light that has passed through the gap between the mounting surface 10a and the body surface 41 out of the light emitted from the light source 10d provided inside the respiratory measurement device 10. Is detected by the photodetector 10e (third detection unit). Specifically, the light source 10d is disposed in the space 31 including the mounting surface 10a inside the respiratory measurement device 10 divided by the light-shielding member (sound collecting member 10b) having a light blocking property, and includes the mounting surface 10a. A light transmission window 10f that transmits light is provided on at least a part of the outer wall of the respiratory measurement device 10 in the empty space 32. The photodetector 10e is disposed in the space 32, and detects light that has passed through the gap between the mounting surface 10a and the body surface 41 and has passed through the light transmission window 10f. The respiratory measurement apparatus 10 according to the present embodiment can detect that the mounting surface 10a is not in close contact with the body surface 41 when the photodetector 10e detects light in such a configuration.

  About the structure (a shape, arrangement | positioning, etc.) of the above-mentioned respiration measuring apparatus 10, you may change suitably. Specifically, as shown in FIG. 12, when the light source 10d is arranged on the space 32 side, the light irradiated by the light source 10d is guided to the inside of the sound collection member 10b (that is, in the space 31). It is good also as a structure provided with the light guide member 10h comprised in this way. According to this, even if the light source 10d cannot be disposed on the space 31 side due to restrictions on mounting, for example, and must be disposed on the space 32 side, the mounting surface 10a and the body surface Since the light irradiated by the light source 10d can pass through the gap between the light source 41 and the light source 41, it can be detected that the mounting surface 10a is not in close contact with the body surface 41. Even in such a configuration, the light source 10d and the light detector 10e are, for example, printed board 10g so that the light detector 10e does not directly detect the light emitted by the light source 10d. It shall be divided.

  Furthermore, the position where the photodetector 10e is arranged is not limited to the position shown in FIG. Specifically, as shown in FIG. 13, the photodetector 10e may be arranged near the center of the substrate. In this case, the light transmission window 10f may be provided at a position where the light detector 10e can easily detect light entering from the light transmission window 10f. Further, for example, the size of the light transmission window 10f may be changed according to the position of the photodetector 10e. Furthermore, if the light that has entered the space 32 through the light transmission window 10f can be detected using, for example, a light guide member and the light source 10d and the light detector 10e are separated, the light The detector 10e may be arranged in the space 31.

  In the present embodiment, the light detector 10e may be configured to detect light that passes through the gap between the mounting surface 10a and the body surface 41 and transmits the light transmission window 10f. The light source 10d may be arranged in the space 32 and the photodetector 10e may be arranged in the space 31.

  In the present embodiment, the light source 10d emits light modulated at a predetermined frequency, and the photodetector 10e is configured to detect light having a predetermined frequency, and the photodetector 10e. When the intensity of the light detected by the above is equal to or higher than a predetermined value, it is detected that the light is not in close contact with the mounting surface 10a body surface 41. In the present embodiment, with such a configuration, the light detector 10e can selectively detect the light irradiated by the light source 10d, so that it is difficult to be influenced by external light.

  Here, the light source 10d has been described as irradiating light modulated at a predetermined frequency. However, the light source 10d irradiates light in a predetermined time-series pattern, so that the photodetector 10e can emit light. You may make it selectively detect the light irradiated by the light source 10d.

  Furthermore, in the present embodiment, by setting the wavelength of the light emitted by the light source 10d to 600 nm or less, the light transmitted through the user's skin despite the mounting surface 10a being in close contact with the body surface 41. It is possible to avoid detection (that is, erroneous detection) by the photodetector 10e.

(Second Embodiment)
Next, a second embodiment will be described. FIG. 14 is a block diagram showing a functional configuration of the respiratory measurement device according to the present embodiment. In FIG. 14, the same parts as those in FIG. 8 described above are denoted by the same reference numerals, and detailed description thereof is omitted. Here, the parts different from FIG. 8 will be mainly described.

  Further, the same parts as those of the first embodiment described above will be described with reference to FIGS.

  As shown in FIG. 14, the respiratory measurement device 100 according to the present embodiment is different from the first embodiment described above in that it includes a control unit 101. The control unit 101 may be realized by software, may be realized by hardware, or may be realized as a combined configuration of software and hardware.

  The control unit 101 has a function of controlling the light source 10d so that light is emitted when a user's breathing sound is not detected.

  Next, a processing procedure of the respiratory measurement device 100 will be described with reference to the flowchart of FIG.

  In the present embodiment, the microphone 10c detects the sound collected by the sound collecting member 10b while the user is wearing the respiratory measurement device 10, as in the first embodiment described above.

  On the other hand, in this embodiment, the light source 10d is controlled by the control unit 101 to be turned on or off. It is assumed that the light source 10d is turned off at the time when the processing of FIG. 15 is started. In this way, when the light source 10d is turned off, the photodetector 10e is also not operating.

  First, the first acquisition unit 11 acquires a sound signal representing a sound detected by the microphone 10c (step S21). The sound signal acquired by the first acquisition unit 11 is stored in a memory inside the first determination unit 12.

  Next, the process of step S22 corresponding to the process of step S2 shown in FIG. 9 described above is executed. When the process of step S22 is executed, it is determined whether there is a breathing sound of the user based on the process result (step S23).

  When it is determined that there is no breathing sound from the user (NO in step S23), the control unit 101 turns on the light source 10d so as to emit light (step S24). When the light source 10d is thus lit, the control unit 101 starts the operation of the photodetector 10e so as to detect light.

  Thereby, the 2nd acquisition part 13 acquires the signal showing the intensity of the light detected by photodetector 10e (Step S25).

  In the present embodiment, after the process of step S25 is executed, the control unit 101 performs control to turn off the light source 10d and stop the operation of the photodetector 10e.

  When the process of step S25 is executed, the second determination unit 14 executes a process corresponding to the process of step S3 shown in FIG. 9 described above. Based on the processing result of the second determination unit 14, it is determined whether or not the wearing surface 10a of the respiratory measurement device 100 is in close contact with the body surface 41 of the user (step S26).

  When it determines with the mounting surface 10a sticking to the body surface 41 (YES of step S26), the 3rd determination part 15 determines with there being no user's respiration (step S27).

  On the other hand, when it determines with there being a user's breathing sound in step S23 (YES of step S23), the 3rd determination part 15 determines with there being a user's breathing (step S28).

  If it is determined in step S26 that the mounting surface 10a is not in close contact with the body surface 41 (NO in step S26), the process of step S28 is executed in the same manner.

  When the process of step S27 or S28 described above is executed, the process of steps S29 and S30 corresponding to the process of steps S5 and S6 shown in FIG. 9 is executed. In addition, when it determines with complete | finishing operation | movement of the respiration measuring apparatus 10 in step S30, it returns to step S21 and a process is repeated.

  As described above, in the present embodiment, light is emitted when the first determination unit 12 determines that there is no body sound (breathing sound) of the user (that is, no breathing sound is detected by the microphone 10c). The light source 10d is controlled (that is, the light source 10d is turned on). In the present embodiment, with such a configuration, it is possible to reduce the power consumption of the respiratory measurement device 100 as compared to the configuration in which the light source 10d is always turned on as in the first embodiment described above. Become. Similarly, it is possible to further reduce power consumption by operating the photodetector 10e when no breathing sound of the user is detected.

  In the present embodiment, the light source 10d is turned off and the operation of the photodetector 10e is stopped after the process of step S25 is executed. However, the light source 10d is once turned on and the photodetector is turned off. After the operation of 10e is started, the lighting of the light source 10d and the operation of the photodetector 10e may be continued until it is determined in step S23 that there is a breathing sound.

(Third embodiment)
Next, a third embodiment will be described. FIG. 16 is a cross-sectional view of the respiratory measurement device according to the present embodiment. In FIG. 16, the same parts as those in FIG. 4 described above are denoted by the same reference numerals, and detailed description thereof is omitted. Here, parts different from FIG. 4 will be mainly described.

  As shown in FIG. 16, the respiratory measurement apparatus 200 according to the present embodiment is different from the first embodiment described above in that it includes a photodetector 10i.

  The photodetector 10i is disposed inside the sound collecting member 10b (that is, in the space 31). The light detector 10i detects light reflected by the user's body surface (skin) 41 among the light irradiated by the light source 10d.

  FIG. 17 is a block diagram illustrating a functional configuration of the respiration measurement device 200. As shown in FIG. 17, the respiratory measurement device 200 includes an extraction unit 201.

  The extraction unit 201 extracts (acquires) information indicating a user's pulse wave (hereinafter referred to as pulse wave information) from an optical signal indicating the intensity of light detected by the photodetector 10i. The pulse wave information extracted by the extraction unit 201 is stored in the storage unit 16.

  Hereinafter, the operation of the respiratory measurement device 200 according to the present embodiment will be described. Here, the operation of the respiratory measurement apparatus 200 when extracting pulse wave information will be mainly described. In addition, since the operation | movement at the time of determining the presence or absence of a user's respiration is the same as that of 1st Embodiment mentioned above, the detailed description is abbreviate | omitted.

  First, as described above, when the wavelength of the light emitted from the light source 10d is 600 nm or less, the light transmitted through the user's skin is not detected by the photodetector 10e, but a part of the light is It enters the body from the body surface 41 of the user. Thus, the light that has entered the body is absorbed and diffused in the body, and a part of the light is emitted from the body surface 41 to the outside again. In the present embodiment, the light reflected by the body surface 41 of the user detected by the photodetector 10 i includes light emitted from the body surface 41 in this way.

  Thus, the amount of light absorbed under the body surface of the user (inside the body) varies depending on the amount of blood under the body surface. Furthermore, the amount of blood increases and decreases in synchronization with the heartbeat. For this reason, the light (its intensity) detected by the photodetector 10i depends on the pulsation (that is, the pulse wave) of the user's heart.

  On the other hand, most of the light emitted by the light source 10d is reflected by the inner surface and the mounting surface (diaphragm) 10a of the sound collecting member 10b and detected by the photodetector 10i.

  For this reason, in this embodiment, the light detected by the photodetector 10i (the time-series signal of the intensity thereof) schematically includes a direct current component that is not related to the pulse wave as shown in FIG. Is expressed as a sum of alternating current components (pulse wave components).

  Therefore, in the present embodiment, the above-described pulse wave information (pulse wave component) is extracted by removing a direct current component from an optical signal indicating the intensity of light detected by the photodetector 10i.

  Specifically, the photodetector 10i includes a photodiode, a current-voltage conversion circuit, a high-pass filter, and an amplifier. According to this, the photodetector 10i uses, for example, an amplifier to select a pulse wave component extracted using a high-pass filter from an optical signal representing the intensity of light detected by a photodiode and a current-voltage conversion circuit. Can be amplified.

  According to such a configuration, the extraction unit 201 can acquire the pulse wave component amplified as described above as pulse wave information.

  The pulse wave information extracted (acquired) by the extraction unit 201 may be a pulse wave component selectively amplified from the optical signal as described above, or obtained by analyzing the pulse wave component. For example, the pulse rate per unit time may be used. The pulse wave information extracted by the extraction unit 201 in this way is stored in, for example, the storage unit 16.

  In the present embodiment, as described above, the user's pulse wave is obtained from the optical signal indicating the intensity of the light (the light reflected by the user's body surface 41) detected by the photodetector 10i (fourth detection unit). The indicated pulse wave signal is extracted. In the present embodiment, with such a configuration, not only the determination result of the presence / absence of breathing of the user described in the first embodiment but also a pulse wave (indicating pulse wave information indicating) useful in the user's examination. It is also possible to utilize the respiratory measurement device 200 to obtain it.

  Here, as described above, the chest to which the respiratory measurement device 200 is attached has a small blood flow. For this reason, for example, the fluctuation of the light amount of the light source 10d has a great influence on the S / N ratio of the pulse wave component, and the S / N ratio is high only with the light (reflected light) emitted from the body surface 41 as described above. There are cases where accurate pulse wave information cannot be obtained.

  Therefore, in the present embodiment, as a modification, in addition to the light reflected by the user's body surface 41 detected by the photodetector 10i, the pulse that uses light that has not reached the user's body surface 41 is used. It can be set as the structure which acquires wave information. Hereinafter, such a modification will be described.

  FIG. 19 is a cross-sectional view of a respiration measuring device 200 ′ according to this modification. In FIG. 19, the same parts as those of FIG. 16 described above are denoted by the same reference numerals, and detailed description thereof is omitted. Here, portions different from FIG. 16 will be mainly described.

  As shown in FIG. 19, a respiration measurement device 200 ′ according to this modification is different from the respiration measurement device 200 described above in that it includes a photodetector 10j and a reflection member 10k.

  The photodetector 10j is disposed inside the sound collection member 10b (that is, in the space 31). The reflecting member 10k is disposed inside the sound collecting member 10b and at a position facing the light source 10d and the photodetector 10j. The reflecting member 10k is configured to reflect the light emitted from the light source 10d, and the reflectance of the reflecting member 10k is constant.

  According to such a configuration, the light irradiated by the light source 10d is reflected by the reflecting member 10k and detected by the photodetector 10j. Thereby, the light detector 10j does not reach the user's body surface 41 among the light irradiated by the light source 10d (light reflected by the reflecting member 10k that is a surface other than the body surface 41). Can be detected.

  Note that the functional configuration of the respiration measuring apparatus 200 ′ according to the present modification is the same as that of FIG. 17 described above, and therefore will be described with reference to FIG. In this modification, the extraction unit 201 uses a pulse signal having a high S / N ratio from an optical signal indicating the intensity of light detected by the photodetector 10i and an optical signal indicating the intensity of light detected by the photodetector 10j. Extract components (pulse wave information).

  Hereinafter, the principle of extracting a pulse wave component having a high S / N ratio in this modification will be described with reference to FIG.

  First, the principle that the fluctuation of the light amount of the light source 10d affects the S / N ratio of the pulse wave component will be described.

  Here, as shown in FIG. 20, the intensity of light emitted from the light source 10d at time t is P (t), and the user wearing the respiratory measurement device 200 ′ including at least the light source 10d and the photodetector 10i is installed. Let R (t) be the reflectance of the body surface 41 at time t.

In general, the reflectance R (t) of the body surface 41 is substantially constant, but changes minutely according to the amount of blood (blood flow) flowing under the body surface (in the body). For this reason, the reflectance R (t) of the body surface 41 can be expressed as the following formula (2).

In the equation (2), R _DC is a constant direct current component, and _RAC is an alternating current component that changes in accordance with the blood flow flowing through the body surface.

Here, in the ideal state, the above-mentioned P (t) since constant is expressed assuming that denoted as P (t) = P _DC, the intensity of light detected by the photodetector 10i (the Optical signal) is proportional to Y ₁ (t) shown by the following equation (3).

In this equation (3), the changing component (AC component) is P _DC R _AC (t), which is proportional to the change in blood flow. That is, pulse wave information (pulse wave signal) corresponding to the blood flow can be obtained (measured) by observing the AC component of the optical signal representing the intensity of light detected by the photodetector 10i.

However, if it is assumed that the light intensity P (t) is not constant and has a minute fluctuation (noise), the P (t) can be expressed as the following equation (4).

Here, P _DC is a constant direct current component, and P _NOISE (t) is a fluctuation component (noise) included in the light source 10d at time t.

In general, P _NOISE (t) is very small as compared with P _DC and is not generally a problem in applications other than pulse wave measurement. However, in consideration of such noise, the above formula ( 3) is rewritten as equation (5).

Here, when the second term in the equation (5) is sufficiently larger than the third and fourth terms, the influence of noise in the equation (5) is small, and thus the above Y ₁ (t ) Can be said to capture a pulse wave signal corresponding to the blood flow.

However, the fourth term of equation (5) is small enough to be ignored compared to the second term, but the third term is not small enough to be ignored compared to the second term. In other words, the intensity of the light detected by the photodetector 10i (representing an optical signal) is affected by noise that cannot be ignored, and an accurate pulse wave signal cannot be extracted from the optical signal. . Therefore, it is important to remove the noise in the third term of Equation (5) (that is, to remove R _DC P _NOISE (t) from Y ₁ (t)) for accurate pulse wave measurement. Become.

Therefore, the principle of removing noise in the third term of the above equation (5) will be described. In addition, the reflectance of the reflecting member 10k shown in FIG. 20 is constant and is expressed as _RC .

A part of the light emitted from the light source 10d is reflected by the reflection member 10k having a reflectance R _C and detected by the photodetector 10j. In this case, the intensity of the light detected by the photodetector 10j (representing the optical signal) is proportional to Y ₂ (t) expressed by the following expression (6) in consideration of the above-described expression (4).

Here, since the reflectance R (t) of the body surface 41 and the reflectance _RC of the reflecting member 10k are different values, Y ₁ (t) in Expression (5) and Y ₂ (t in Expression (6) ) And there is a difference. For this reason, it is considered that the noise in the third term of the formula (5) is removed by multiplying Y ₂ (t) by an appropriate coefficient α and then subtracting from Y ₁ (t). In this case, as described above, if the fourth term in equation (5) is sufficiently smaller than the second term and can be ignored, the following equation (7) can be obtained.

If the coefficient α is R _DC / _RC in the equation (7), the third term (and the first term) in the equation (7) becomes zero, so Y ₁ (t) −αY ₂ (t ) Change component (AC component) is only P _DC R _AC (t) of the second term, and noise P _NOISE (t) caused by fluctuation of the light amount of the light source 10d can be removed.

  In this modification, pulse wave information with a high S / N ratio is extracted based on the principle described above. Hereinafter, with reference to the flowchart shown in FIG. 21, a processing procedure of the respiratory measurement device 200 ′ when extracting pulse wave information in the present modification will be described.

  In the present modification, the photodetectors 10i and 10j operate continuously while the user wears the respiration measurement device 200 ′. As a result, optical signals indicating the intensity of light detected by the photodetectors 10 i and 10 j are output to the extraction unit 201.

  The optical signal output from the photodetector 10i is, for example, a signal obtained by amplifying an AC component obtained by removing a DC component and an unnecessary high-frequency component from a signal indicating the intensity of light detected by the photodetector 10i. . The same applies to the optical signal output from the photodetector 10j. In this case, the extraction unit 201 acquires the optical signal output from the photodetector 10i (hereinafter referred to as the first optical signal) (step S41). The first optical signal acquired by the extraction unit 201 is stored in a memory inside the extraction unit 201.

  Further, the extraction unit 201 acquires the optical signal output from the photodetector 10j (hereinafter referred to as second optical signal 9) (step S42). The second optical signal acquired by the extraction unit 201 is the extraction unit. 201 is stored in the internal memory of 201.

Here, as described above, when the photodetectors 10i and 10j continuously operate, the extraction unit 201 repeatedly acquires the first optical signal and the second optical signal. In the following description, the first optical signal and the second optical signal (the values thereof) acquired at the n-th (n is an integer equal to or greater than 1) are denoted as Y ₁ (n) and Y ₂ (n), respectively.

  Next, the extraction unit 201 determines whether each of the first optical signal and the second optical signal has been acquired a predetermined number of times (hereinafter referred to as a predetermined number of times) (step S43). In the following description, it is assumed that the predetermined number of times is N (N is an integer of 1 or more).

  When it is determined that each of the first optical signal and the second optical signal has not been acquired N times (NO in step S43), the process returns to the above-described step S41 and is repeated. That is, the processes of steps S41 and S42 are repeated until each of the first optical signal and the second optical signal is acquired N times.

On the other hand, when it is determined that each of the first optical signal and the second optical signal has been acquired N times (YES in step S43), the memory inside the extraction unit 201 stores N values Y related to the first optical signal. ₁ (n) (n = 1, 2,..., N) and N values Y ₂ (n) (n = 1, 2,..., N) related to the second optical signal are stored.

The extraction unit 201 determines (calculates) the coefficients a and b using Y ₁ (n) and Y ₂ (n) so that X given by the following equation (8) is minimized ( Step S44).

  Note that the determination processing of the coefficients a and b is a general optimization problem, and a known method can be used in step S44.

Next, the extraction unit 201 performs a process of subtracting the second optical signal from the first optical signal using the coefficients a and b determined in Step S44 (Step S45). Specifically, the extraction unit 201 applies the coefficients a and b to the following equation (9) to thereby obtain the time series Y _S (n) of the optical signal from which noise is removed (where n = 1, 2, ..., N).

When the processing of step S45 is executed, the extraction unit 201 outputs the processing result, that is, the time series Y _S (n) of the signal from which noise has been removed (step S46). Thus, the time series Y _S (n) of the signal output by the extraction unit 201 corresponds to pulse wave information indicating the pulse wave of the user from which noise has been removed, and is stored in the storage unit 16, for example.

  In FIG. 21, it is shown that the process of the respiration measurement device 200 ′ ends when the process of step S <b> 46 is executed. However, for example, the respiration measurement device 10 is turned off in the process shown in FIG. 21. It may be repeated until such an operation is performed, or may be executed at a predetermined time interval, or may be repeatedly executed only at a predetermined time zone.

  As described above, in the present modification, the photodetector 10j is derived from the first optical signal that represents the intensity of the light detected by the photodetector 10i (fourth detector) (the light reflected by the user's body surface 41). Pulse wave information indicating the user's pulse wave is extracted by subtracting the second optical signal representing the intensity of the light (light not reflected by the user's body surface 41) detected by the (fifth detection unit). In the present modification, it is possible to extract pulse wave information from which noise due to fluctuations included in the light amount of the light source 10d is removed as compared with the above-described respiration measurement device 200 with this configuration. Therefore, more useful information can be obtained.

  In the present modification, the light detector 10j has been described as having a configuration including the reflecting member 10k in order to detect the light emitted by the light source 10d. However, in the present modification, the light detector 10j is the user's For example, a configuration other than that shown in FIG. 19 may be used as long as light that is not reflected by the body surface 41 can be detected. That is, for example, the light detector 10j may detect light guided by using a light guide member among the light irradiated by the light source 10d, or the light irradiated by the light source 10d can be directly detected. You may make it arrange | position the photodetector 10j in an appropriate position.

  According to at least one embodiment described above, it is possible to provide a respiratory measurement device, a respiratory measurement method, and a program that are useful for testing sleep apnea syndrome.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  10, 100, 200, 200 '... respiration measuring device, 10a ... mounting surface, 10b ... sound collecting member, 10c ... microphone (first detection means), 10d ... light source, 10e ... light detector (third detection means), 10f: Light transmission window (light transmission means), 10g ... Printed circuit board, 10h ... Light guide member, 10i ... Photo detector (fourth detection means), 10j ... Photo detector (fifth detection means), 10k ... Reflection member , 11 ... 1st acquisition part, 12 ... 1st determination part, 13 ... 2nd acquisition part, 14 ... 2nd determination part, 15 ... 3rd determination part, 16 ... Storage part, 20 ... Double-sided adhesive tape, 101 ... Control Part, 201... Extraction part.

Claims (12)

In a respiratory measurement device that is used by attaching the wearing surface to the user's body surface,
First detection means for detecting a body sound of the user that is generated along with breathing;
Second detection means for detecting that the mounting surface is not in close contact with the body surface;
A respiration measurement device comprising: a determination unit that determines whether or not the user breathes based on a detection result by the first detection unit and a detection result by the second detection unit.   The determination means determines that there is no breathing of the user when the body sound is not detected and it is not detected that the wearing surface is not in close contact with the body surface. The respiratory measurement device described. The second detection means includes
A light source provided inside the respiratory measurement device;
Third detection means for detecting light, and
Of the light emitted from the light source, when the light passing through the gap between the mounting surface and the body surface is detected by the third detection means, the mounting surface is not in close contact with the body surface The respiration measurement device according to claim 1. The light source is disposed in one of a space including the mounting surface and a space not including the mounting surface inside the respiratory measurement device divided by a light blocking member having a light blocking property,
At least a part of the outer wall of the respiratory measurement device in a space that does not include the mounting surface is provided with a light transmission means that transmits light,
The third detection means is disposed in the other of the space including the mounting surface and the space not including the mounting surface, and passes through the gap and transmits the light transmitted through the light transmission means. The respiration measuring device according to claim 3, wherein the respiration measuring device is detected.   The respiratory measurement device according to claim 3, further comprising a control unit that controls the light source so that light is emitted when the body sound is not detected. The light source emits light modulated at a predetermined frequency,
The third detecting means detects light of the predetermined frequency;
The second detection means detects that the mounting surface is not in close contact with the body surface when the intensity of light detected by the third detection means is equal to or greater than a predetermined value. The respiratory measurement device according to claim 3. The light source emits light in a predetermined time series pattern,
The third detecting means detects the light of the predetermined time series pattern,
The second detection means detects that the mounting surface is not in close contact with the body surface when the intensity of light detected by the third detection means is equal to or greater than a predetermined value. The respiratory measurement device according to claim 3.   The respiration measurement apparatus according to claim 3, wherein the wavelength of light emitted from the light source is 600 nm or less. A fourth detection means for detecting light reflected by the user's body surface among the light irradiated by the light source;
4. The respiratory measurement apparatus according to claim 3, further comprising extraction means for extracting pulse wave information indicating the pulse wave of the user from a signal indicating the intensity of light detected by the fourth detection means. A fourth detection means for detecting light reflected by the user's body surface among the light irradiated by the light source;
Fifth detection means for detecting light that is not reflected by the user's body surface among the light emitted by the light source;
Pulse wave information indicating the pulse wave of the user by subtracting a second signal indicating the intensity of light detected by the fifth detection means from a first signal indicating the intensity of light detected by the fourth detection means. The respiratory measurement device according to claim 3, wherein the respiration measurement device is extracted. A respiration measurement method executed by a respiration measurement device used by attaching a wearing surface to a user's body surface,
Detecting the body sound of the user that occurs with breathing;
Detecting that the wearing surface is not in close contact with the body surface;
Determining the presence or absence of breathing of the user based on the detection result of the body sound and the detection result of non-contact. A program that is executed by a computer of a respiratory measurement device that is used by mounting the mounting surface on the body surface of a user,
In the computer,
Detecting the body sound of the user that occurs with breathing;
Detecting that the wearing surface is not in close contact with the body surface;
A program for executing the step of determining the presence or absence of breathing of the user based on the detection result of the body sound and the detection result of non-contact.

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