JP6631783B2 - Measuring system and measuring method for measuring life activity caused by respiration of subject - Google Patents

Description

  The present invention relates to a measurement system and a measurement method for measuring a biological activity caused by a subject's respiration.

  Conventionally, for example, an electrode impedance method and a thermistor method have been known as respiration measurement methods for measuring a subject's respiration. In the electrode impedance method, an electrode is attached to a subject, and a voltage corresponding to a change in impedance between the electrodes due to respiration is detected. In the thermistor method, a thermistor (sensor) is mounted near a nostril of a subject, and a voltage corresponding to a resistance value that changes with a change in temperature of exhalation is detected. According to such a method, it is necessary to bring the electrodes and sensors into contact with the subject and wear them. For this reason, the mounting and the processing of the lead wires are troublesome. In order to solve this problem, a non-invasive and non-contact type biometric device has been developed. As a living body measurement device, for example, a respiration measurement device that measures a subject's respiration during sleep is known.

  Patent Literature 1 discloses a respiratory measurement device including a biological information sensor that measures biological information of a subject in a non-contact and non-restricted manner. An infrared camera is used as a biological information sensor. By measuring the body surface temperature of the subject's nasal cavity region using thermography and analyzing the change in temperature (temperature difference), the presence or absence of respiration is detected. When exhaling, the temperature of the body surface near the nasal cavity rises due to the warmed air inside the body, and when inhaling, the body surface temperature near the nasal cavity falls due to outside air. According to the respiratory measurement device of Patent Literature 1, it is possible to grasp a respiratory state from a nasal cavity by using a change in body surface temperature due to respiration.

JP 2006-115865 A

  However, according to the study by the present inventor, the temperature change during respiration is small depending on the measurement environment such as when the temperature in the measurement room is high, and noise may affect the respiration waveform. In that case, it is impossible to accurately grasp the respiratory state from the nasal cavity. In this specification, waveform data obtained by plotting the temperature in a predetermined region on the vertical axis in time series with respect to the horizontal axis as the time axis is referred to as a “respiratory waveform”.

  More specifically, when the person exhales, the air heated inside the body goes out of the nasal cavity, so that the body surface temperature near the nasal cavity rises. On the other hand, when inhaling, outside air having a lower temperature than the body temperature enters the body from the nasal cavity, and the body surface temperature near the nasal cavity decreases. However, the temperature of the air heated in the body is considered to be at most about 37 ° C., and when the temperature in the measurement room is about 30 ° C., the temperature difference detected during respiration is assumed to be small.

  The subject naturally breathes not only through the nose but also through the mouth. For example, when the nose is obstructed, the subject mainly breathes by mouth, so that the inflow and outflow of air through the nasal cavity is restricted, and no airflow occurs. Therefore, it is difficult to obtain temperature information from the nasal cavity. The respiratory measurement device of Patent Literature 1 monitors only the body surface temperature in the vicinity of the nasal cavity and does not consider expiration or inhalation from the mouth at all. Therefore, it is difficult to accurately grasp the respiratory state of the subject. As described above, the conventional respiratory measurement device is easily affected by changes in the measurement environment and the physical condition of the subject, and cannot be said to be robust.

  The present invention has been made in order to solve the above-mentioned problem, and is a measurement method (hereinafter simply referred to as a “method for measuring a biological activity caused by respiration of a subject” that is robust against a change in a measurement environment and a physical condition of the subject. Measurement method ").

  A measurement method according to an embodiment of the present invention measures a life activity caused by a subject's respiration by using a life activity measurement system including a thermography camera and an image processing device that processes a moving image from the thermography camera. (A) a mask formed of a material whose material temperature is lower than the body temperature of the subject and whose temperature changes due to exhalation and inhalation of the subject, (B) the thermographic camera captures the mask placed on the subject to acquire the moving image composed of a plurality of frame images; c) the image processing device calculates a temperature change in the region of the mask that has occurred over the plurality of frame images, and calculates a temperature change caused by the respiration of the subject. Comprising the step of measuring on the basis of the biological activity to the temperature change, the.

  In one embodiment, the material of the mask may be a nonwoven fabric.

  In one embodiment, the step (a) may further include a step of applying a nasal cavity expanding tape to the subject's nose so that the subject's nasal cavity is expanded.

  In one embodiment, the mask has a skeleton structure for maintaining its shape, and a part thereof is not in contact with the face of the subject by a member adhered to the nose of the subject by the nasal cavity expansion tape. May be supported.

  In one embodiment, the mask may be a bottom mask.

  In one embodiment, in the step (a), the mask may be arranged so as to contact a chin of the subject.

  In one embodiment, in the step (c), the image processing device specifies an area of the mask included in each of the plurality of frame images, and determines a temperature change over the plurality of frame images in the area of the mask. May be further specified, and the biological activity caused by the respiration of the subject may be measured based on the temperature change of the partial region.

  In one embodiment, the image processing apparatus calculates, for each frame image, a temperature change for each of a plurality of divided regions included in the region of the mask, and among the plurality of divided regions, a divided region having the largest temperature change. Based on the temperature change of the area, the biological activity due to the respiration of the subject may be measured.

  A measurement system according to an embodiment of the present invention is a system that analyzes a moving image of a subject in which a mask is arranged so as to cover a nostril and a mouth, and measures a biological activity due to respiration of the subject, The mask has a material temperature lower than the body temperature of the subject, and is formed of a material whose temperature changes due to the subject's exhalation and inhalation, and images the mask placed on the subject, A thermographic camera that generates the moving image composed of a plurality of frame images, and receives the moving image, calculates a temperature change in the area of the mask generated over the plurality of frame images, and performs respiration of the subject. And an image processing device that measures the resulting life activity based on the temperature change.

  According to one embodiment of the present invention, a measurement method that is robust against a change in a measurement environment and a physical condition of a subject is provided.

FIG. 1 is a block configuration diagram of a measurement system 100 according to a first embodiment. FIG. 3 is a schematic diagram showing a state in which the face of a subject 40 wearing a mask 30 is viewed from directly above. FIG. 2 is a hardware configuration diagram of the image processing apparatus 20. 5 is a flowchart illustrating an example of a processing procedure of the measurement system 100. It is a schematic diagram which shows the frame image divided | segmented into several division area. 7 is a respiratory waveform showing a change in a time-series temperature distribution in a certain region. FIG. 4 is a schematic diagram showing a state in which air is ventilated by breathing from a nostril and a mouth in a space between a mask 30 and a face. It is a schematic diagram which shows a mode that the temperature of the mask 30 rises by exhalation. FIG. 3 is a schematic diagram showing a state in which the temperature of a mask 30 is lowered by inhalation. FIG. 4 is a schematic diagram showing a state in which air is ventilated by breathing from a nostril and a mouth in a space between a mask and a face in a state where a nasal cavity expansion tape is stuck to a subject. FIG. 3 is a schematic diagram showing a state in which a face of a subject 40 wearing a mask 30 and having attached a nasal cavity expansion tape 31 is viewed from directly above. It is a schematic diagram which shows a mode that the ventilation of the air by the respiration from a nostril and a mouth arises in the space between the mask 30 of a downward type and a face. FIG. 3 is a schematic diagram showing a state in which the face of a subject 40 wearing a downward receiving mask 30 is viewed from directly above.

  A measurement method according to an embodiment of the present invention includes a biological activity measurement system including a thermography camera and an image processing device that processes a moving image from the thermography camera (hereinafter, may be referred to as a “measurement system”). It is suitably used. The measurement method is as follows: (a) A mask formed of a material whose material temperature is lower than the body temperature of a subject and whose temperature changes by exhalation and inhalation of the subject is placed so as to cover the nostrils and mouth of the subject. Arranging; (b) a thermographic camera capturing a mask arranged on the subject to obtain a moving image composed of a plurality of frame images; and (c) an image processing apparatus comprising: Calculating a temperature change in a region of the mask that has occurred over the frame image and measuring a biological activity due to respiration of the subject based on the temperature change. The material of the mask has good air permeability and is preferably a nonwoven fabric. In this specification, the subject is described as a human, but may be an animal other than a human (a pet animal such as a dog or a cat, or an experimental animal such as a pig or a mouse). Animals (including humans) to be measured may be collectively referred to as “subjects”.

  According to the embodiment of the present invention, it is possible to non-invasively measure a biological activity due to a subject's respiration, and to perform a measurement robust to a change in a measurement environment and a physical condition of the subject.

  Hereinafter, a measurement method according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the same or similar components are denoted by the same reference numerals. Note that the measurement method according to the embodiment of the present invention is not limited to the method illustrated below. For example, one embodiment can be combined with another embodiment.

(1st Embodiment)
FIG. 1 schematically shows a configuration of a measurement system 100 according to the present embodiment. The measurement system 100 typically includes a thermographic camera 10, an image processing device 20, and a mask 30. Although the subject 40 is shown in FIG. 1, it is needless to say that the subject 40 is not included in the measurement system 100.

  The measurement system 100 is used to observe the life activity of the subject 40. In the present embodiment, it is assumed that the life activity is the respiration of the subject 40, and the measurement system 100 measures the respiration rate within a predetermined period.

  The thermography camera 10 is a so-called infrared thermography, and is an imaging device for imaging infrared radiation energy. The thermographic camera 10 can image an object at a frame rate of, for example, 60 fps, and generate a moving image including a plurality of frame images in real time. Each frame image of the plurality of generated frame images includes information indicating the temperature distribution of the object.

  The thermographic camera 10 detects the amount of energy of infrared rays naturally emitted from an object (for example, the subject 40), and generates two-dimensional temperature distribution information as a surface based on the detected amount. The higher the surface temperature of the object, the higher the energy of the emitted infrared radiation. For example, the thermographic camera 10 can display a temperature distribution with a display color corresponding to the amount of infrared energy. The thermographic camera 10 can detect far-infrared rays having a wavelength in the range of 7.5 μm to 14.0 μm, for example.

  The thermographic camera 10 is arranged in the measurement system 100 so as to capture the mask 30 attached to the face of the subject 40. The thermographic camera 10 is electrically connected to the image processing device 20 by wire or wirelessly, and sends moving image data, that is, information on temperature distribution to the image processing device 20.

  As shown in FIG. 1, it is possible to further arrange a thermographic camera 11 and image the periphery of the face of the subject 40 with a plurality of cameras. By using a plurality of cameras, even when one camera is blocked by something and the image is disturbed, the measurement can be continued using the image of another camera. It is also possible to measure a plurality of subjects at the same time.

  The image processing device 20 processes the moving image data including the information on the temperature distribution from the thermographic camera 10 to measure the life activity caused by the respiration of the subject 40. The image processing device 20 is typically a personal computer (PC). Details of the structure and operation of the image processing device 20 will be described later.

  FIG. 2 schematically shows a state in which the face of the subject 40 wearing the mask 30 is viewed from directly above.

  A material having good air permeability is suitably used for the mask 30. More specifically, the material of the mask 30 has a material temperature lower than the body temperature of the subject 40 (for example, 27 ° C. which is about the same as the room temperature), and the temperature of the material changes due to the exhalation and inspiration of the subject 40 (changes). Easy) material. For example, the material temperature is preferably about the same as room temperature (27 ° C.). Nonwoven fabrics are suitable for such materials. In the embodiment of the present invention, a nonwoven fabric mask that can be purchased by anyone at a pharmacy or the like can be widely used. In addition to the nonwoven fabric, the respiration of the subject 40 can be measured using, for example, a general cloth, a gauze mask, or a tissue.

  The inventor of the present application actually measured using a nonwoven fabric under a condition where sufficient exhalation and inspiration were obtained from the subject 40, and the temperature of the nonwoven fabric was in a range of 25.4 ° C to 37.2 ° C with the exhalation and inhalation. Was confirmed to change. It was found that a temperature difference of about 10 ° C. was obtained.

  As shown in FIG. 2, the mask 30 typically has a string to be worn on the ear for wearing, but is fixed to the face by other fasteners (for example, tape) instead of the string. No problem. Such a form of the mask without a string is also within the scope of the present invention.

  The display 50 is a device mainly for displaying a measurement result of a life activity caused by the respiration of the subject 40. The display 50 is, for example, a liquid crystal display or an organic EL display. Note that it is naturally possible to use a device in which the image processing device 20 and the display 50 are integrated. FIG. 1 illustrates a laptop PC as such a device.

  FIG. 3 illustrates an example of a hardware configuration of the image processing apparatus 20 of the measurement system 100. In the present embodiment, the image processing device 20 is electrically connected to the thermographic camera 10 and the display 50. The image processing device 20 receives the captured moving image data from the thermography camera 10. Further, the display 50 displays a change in the temperature distribution of the mask 30, a respiratory rate, and the like. The image processing device 20 may display a warning on the display 50 when determining based on the measurement result that the imaging direction of the thermographic camera 10 is not appropriate.

  The image processing device 20 includes a CPU 201, a ROM 202, a RAM 203, a hard disk drive (HDD) 204, an interface (I / F) 205, and an image processing circuit 206. The CPU 201 controls the entire operation of the image processing device 20. The ROM 202 stores a computer program. The computer program is, for example, a group of instructions for causing the CPU 201 and / or the image processing circuit 206 to perform a process shown by a flowchart described later. The RAM 203 is a work memory for expanding a computer program when the CPU 201 executes the program. The HDD 204 is a storage device that stores the moving image data received from the thermographic camera 10, the measured data of the respiration rate of the subject 40, and the like.

  The I / F 205 is an interface for the image processing apparatus 20 to receive moving image data including temperature distribution information from the thermographic camera 10. When the image processing apparatus 20 receives moving image data via a wired network, the I / F 205 may be, for example, an Ethernet (registered trademark) terminal. When the image processing apparatus 20 receives moving image data via a wireless network, the I / F 205 may be, for example, a transmission / reception circuit that performs communication conforming to the Wi-Fi (registered trademark) standard. Alternatively, the I / F 205 may be a wired video input terminal.

  The image processing circuit 206 is a so-called graphics processor that analyzes moving image data. The image processing circuit 206 receives moving image data from the thermographic camera 10 and analyzes a change in temperature distribution over a plurality of frame images. More specifically, the image processing circuit 206 calculates a temperature change in the area of the mask 30 over a plurality of frame images based on temperature distribution information for each frame image, and based on the temperature changes, Measure the life activity caused by respiration.

  In the present embodiment, the image processing circuit 206 is provided separately from the CPU 201, but this is an example. An integrated circuit in which the CPU 201 and the image processing circuit 206 are integrated may be used, or a part of the processing of the image processing circuit 206 may be performed by the CPU 201.

  With reference to FIG. 4, an overall operation of the measurement system 100 will be described, and an example of mainly measuring a respiration rate will be described. However, the respiratory rate is an example of the life activity caused by the respiration of the subject 40, and another life activity caused by the respiration of the subject 40 may be measured. Typically, other biological activities that can be evaluated using a respiratory waveform, for example, biological activities such as breathing depth, turbulence, apnea period, and the frequency of occurrence of the apnea period are referred to herein. This is the category of the biological activity to be measured.

  FIG. 4 shows an example of a processing procedure of the measurement system 100. FIG. 5 schematically shows a frame image divided into a plurality of divided regions. FIG. 6 shows an example of a respiratory waveform showing a change in a time-series temperature distribution in a certain area.

(Step S1)
The observer or the subject 40 places the mask 30 at a position where ventilation of air by respiration occurs so as to cover the nostrils and the mouth of the subject 40.

(Step S2)
The thermographic camera 10 images the subject 40 so that the mask 30 fits in the frame. The thermography camera 10 continuously captures an image of the subject 40 for one hour at a frame rate of 60 fps, for example, and acquires moving image data. The thermographic camera 10 may have a zoom function, and may perform zoom photographing so that mainly the mask 30 only falls within the angle of view.

  The thermographic camera 10 may have an HDD or the like for recording moving image data therein. When the real-time processing of the moving image data is not particularly required, the thermographic camera 10 may temporarily store the moving image data in an internal HDD or an HDD provided outside the camera 10. In that case, the CPU 201 may transmit a command to the thermographic camera 10 to transmit a series of moving image data as needed, and the image processing circuit 206 may process the received moving image data after the fact. .

(Step S3)
The image processing circuit 206 receives moving image data from the thermographic camera 10. The image processing circuit 206 divides each of the plurality of frame images constituting the moving image into a plurality of divided regions P as shown in FIG. Note that “divide” does not require division as an actual operation. For example, an operation of setting the size of the divided region P as a unit for cutting out an image or a unit for performing processing may be included in the operation of “dividing” here.

  The plurality of divided areas P are set on the frame image so as to divide the area of the mask 30 into, for example, 3 × 3 or more. The size of each divided region P is determined depending on the resolution, the angle of view, and the like of the thermographic camera 10, and may be, for example, 16 × 16 pixels.

(Step S4)
The image processing circuit 206 can specify the area of the mask 30 in the frame image using any known method. For example, the image processing circuit 206 specifies a coordinate position of the mask 30 by performing a pattern matching process on each frame image using a feature (for example, a rectangular shape) of the mask 30 that is stored in advance. The coordinate position of the mask 30 means, for example, the coordinates of each vertex, center, or center of gravity of the area of the mask 30. By using the mask 30 having a relatively large size and a fixed shape, the pattern matching process can be simplified.

(Step S5)
It is believed that the ventilation of the air by respiration from the nostrils and / or mouth allows temperature changes to be observed throughout the area of the mask 30. However, there is a possibility that the temperature change may vary depending on the observation place. For this reason, in the present embodiment, the image processing circuit 206 further specifies an area where the temperature change is particularly large (may be referred to as a monitoring area) in the area of the mask 30.

  The image processing circuit 206 calculates the average of the temperature distribution for each divided region P in the region of the mask 30 specified based on the coordinate position acquired in step S4, and calculates the average of the temperature distribution for a predetermined period (for example, the past 20 seconds). A respiratory waveform is generated based on time-series data indicating a change in the average of the temperature distribution. Alternatively, the image processing circuit 206 may generate a respiratory waveform based on time-series data indicating a change in an integrated value or a representative value of the temperature distribution of the divided region P during a predetermined period. In this specification, the average, integration, or representative value of the temperature distribution in a certain region may be referred to as “region temperature”.

  The respiratory waveform shows a time-series change in temperature in a certain area. As shown in FIG. 6, the respiratory waveform obtained from the region where the respiratory state of the subject 40 can be faithfully reproduced does not include distortion, is drawn by a smooth curve, and the temperature of the region periodically changes. I understand. The temperature difference between two adjacent maxima and minima in the respiratory waveform is defined as the amplitude of the respiratory waveform.

  For example, a predetermined period of 20 seconds corresponds to a subject's general respiratory rate of 3 bpm. In that case, the image processing circuit 206 generates a respiratory waveform based on the time-series data of the past 20 seconds (equivalent to 600 frames when the frame rate is 30 fps) from the present time while accessing the RAM 203 and the HDD 204.

  The image processing circuit 206 calculates the difference between the maximum value and the minimum value of the respiration waveform (that is, the temperature difference) for each of the divided regions P. In other words, the image processing circuit 206 calculates the amplitude of the respiratory waveform for each divided area P. The image processing circuit 206 sets a divided region having the largest amplitude of the respiratory waveform among the plurality of divided regions P as a monitoring region. If the temperature change can be observed substantially uniformly in the area of the mask 30, the processing in step 5 may be omitted. In that case, any of the divided areas P in the area of the mask 30 can be set as the monitoring area.

(Step S6)
The image processing circuit 206 measures the respiratory rate of the subject 40 based on a change in the temperature of the monitoring area (that is, a respiratory waveform). As shown in FIG. 6, the time difference between two adjacent maximum points or minimum points corresponds to the respiration cycle (s) of the subject 40. The respiration rate (bpm) can be expressed as 60 / respiration cycle (s).

  The display 50 mainly displays the respiratory rate of the subject 40. In addition to the respiratory rate, the display 50 can also display, for example, a trend of the respiratory rate and a moving image captured by the thermographic camera 10. The respiratory rate trend is a waveform indicating a temporal change in the respiratory rate.

  FIG. 7 schematically shows a state in which air is ventilated by breathing from a nostril and a mouth in a space between the mask 30 and the face. By arranging the mask 30 so as to cover the nostrils and the mouth, it is possible to grasp the respiratory state by using the temperature change of the material of the mask 30 (that is, the nonwoven fabric). As a result, it is possible to simultaneously measure the ventilation of air due to breathing from the nostrils and the mouth, and to measure the ventilation due to breathing from the mouth even when the nose is blocked. In addition, since the temperature change can be observed in the entire area of the mask 30, it is possible to observe the temperature change in the same area whether breathing through the nostrils or the mouth. It is.

  FIG. 8A shows a state where the temperature of the mask 30 is increased by exhalation. When the subject 40 exhales, the nonwoven fabric is warmed by the air warmed in the body. Since the temperature of the nonwoven fabric itself is close to the temperature in the measurement room (for example, 27 ° C.) and lower than the body temperature, the temperature change during exhalation is large.

  FIG. 8B shows a state where the temperature of the mask 30 is lowered by the intake air. When the subject 40 inhales, the temperature of the nonwoven fabric warmed by exhalation tends to be lowered by the heat of vaporization generated when outside air passes through the nonwoven fabric. By using the heat of vaporization, the temperature change during breathing increases. As described above, by using the nonwoven fabric mask, the temperature change of the mask 30 during breathing can be increased.

  According to the present embodiment, the amplitude of the respiratory waveform can be made larger than the amplitude of the respiratory waveform obtained by the conventional respiratory measurement device. As a result, the SN ratio of the respiratory waveform is improved, and the respiratory rate of the subject 40 can be measured more accurately.

(Second embodiment)
The measurement method according to the second embodiment differs from the measurement method according to the first embodiment in that measurement is performed by attaching a nasal cavity expansion tape 31 to a subject so that the nasal cavity of the subject 40 expands. Hereinafter, a description will be given focusing on differences from the first embodiment.

  The configuration of the measurement system that can use the measurement method according to the second embodiment is the same as that of the measurement system 100 according to the first embodiment, and a description thereof will be omitted.

  FIG. 9A schematically illustrates a state in which air is ventilated by breathing from a nostril and a mouth in a space between the mask 30 and the face in a state where the nasal cavity expansion tape 31 is stuck to the subject 40. . FIG. 9B schematically illustrates a state in which the face of the subject 40 wearing the mask 30 and attaching the nasal cavity expansion tape 31 is viewed from directly above.

  A member 32 having one end to which a nasal cavity expansion tape 31 is adhered is attached to the mask 30 used in the present embodiment in a hanging state. The mask 30 is supported by the member 32 by attaching the nasal cavity expansion tape 31 to the nose 40N of the subject 40. Heat conducted from the skin can be a noise in the respiratory waveform. Therefore, in order to prevent heat from being conducted from the skin to the mask 30 through the member 32, it is preferable that the heat conductivity of the member 32 be low. For example, the thermal conductivity of the member 32 is about 0.20 to 0.33 (W / m · K). It is preferable that the member 32 has a strength that can support the mask 30. For example, a polyethylene terephthalate (PET) resin can be used as the material of the member 32.

  At the same time, the mask 30 is placed on the subject 40 at a position where ventilation of air by respiration occurs so as to cover the nostrils and the mouth, and at the same time, a nasal cavity expanding tape 60 is applied so that the nasal cavity is expanded. Since the mask 30 is supported by the high-strength member 32, the mask 30 may be suspended in the air as illustrated. Therefore, direct heat conduction from the skin can be suppressed. In the suspended state, the mask 30 preferably has a structure (for example, a skeleton) for maintaining the shape. Further, by using the nasal cavity expansion tape 60, the nasal congestion can be improved, and the ventilation state of air by breathing from the nostrils and the mouth can be further improved.

  According to the present embodiment, a further improvement in the SN ratio of the respiratory waveform is expected.

(Third embodiment)
The measurement method according to the third embodiment is different from the measurement method according to the first embodiment in that an under mask 30 is used. Hereinafter, a description will be given focusing on differences from the first embodiment.

  The configuration of the measurement system that can use the measurement method according to the third embodiment is the same as the configuration of the measurement system 100 according to the first embodiment, and a description thereof will be omitted.

  FIG. 10A schematically illustrates a state in which air is ventilated by breathing from a nostril and a mouth in a space between the mask 30 and the face. FIG. 10B schematically shows a state in which the face of the subject 40 wearing the mask 30 of the downward receiving type is viewed from directly above.

  The mask 30 used in the present embodiment has the same shape as a so-called sanitary transparent mask. In the present specification, a mask having such a shape is referred to as a “underlay mask”. As shown in FIG. 10B, a member 33 is attached to the lower end of the mask 30. The thermal conductivity of the member 33 is preferably low, like the member 32 described in the second embodiment. For example, a PET resin can be used as a material of the member 33.

  The mask 30 is arranged so that the member 33 contacts the chin of the subject 40. This can prevent heat from being conducted from the skin to the mask 30 via the member 33. Further, in order to suppress direct heat conduction from the skin, the mask 30 is preferably supported by the member 33 so as to be suspended, as in the second embodiment. Preferably has a structure (for example, a skeleton) that maintains its shape.

  According to the present embodiment, the feeling of obstruction when the mask 30 is worn on the subject 40 can be reduced.

  The present specification discloses a measurement system and a measurement method of a biological activity caused by respiration of a subject described in the following items.

[Item 1]
Thermography camera, and an image processing device that processes a moving image from the thermography camera, using a life activity measurement system including, a measurement method for measuring the life activity caused by the respiration of the subject,
(A) A mask formed of a material whose material temperature is lower than the body temperature of the subject and whose temperature changes by exhalation and inhalation of the subject is arranged so as to cover the nostrils and mouth of the subject. Steps and
(B) the thermographic camera takes an image of the mask placed on the subject, and obtains the moving image composed of a plurality of frame images;
(C) calculating, by the image processing device, a temperature change in the region of the mask, which has occurred over the plurality of frame images, and measures a biological activity due to respiration of the subject based on the temperature change; ,
A measurement method.

  According to the measurement method described in Item 1, a measurement method for measuring a biological activity caused by respiration of a subject, which is robust to a change in a measurement environment and a physical condition of the subject, is provided.

[Item 2]
2. The measuring method according to item 1, wherein the material of the mask is a nonwoven fabric.

  According to the measurement method described in Item 2, it is possible to measure the biological activity caused by the respiration of the subject by using an easily available and inexpensive nonwoven fabric mask.

[Item 3]
3. The measurement method according to item 1 or 2, wherein the step (a) further includes a step of applying a nasal cavity expansion tape to the subject's nose so that the subject's nasal cavity is expanded.

  According to the measurement method described in Item 3, nasal congestion can be improved, and the state of air ventilation by breathing from the nostrils and the mouth can be improved.

[Item 4]
The mask has a skeleton structure for maintaining its shape, and is partially supported by a member attached to the nose of the subject by the nasal cavity expansion tape so as not to contact the face of the subject. , The measurement method according to item 3.

  According to the measuring method described in Item 4, direct heat conduction from the skin can be suppressed.

[Item 5]
3. The measurement method according to item 1 or 2, wherein the mask is a bottom mask.

  According to the measurement method described in the item 5, a variation of the mask is provided.

[Item 6]
The measurement method according to item 5, wherein in the step (a), the mask is arranged so as to be in contact with a chin of the subject.

  According to the measurement method described in Item 6, it is possible to prevent heat from being transmitted from the skin to the mask via the member.

[Item 7]
In the step (c), the image processing apparatus specifies an area of the mask included in each of the plurality of frame images, and a partial area in the area of the mask where a temperature change occurs over the plurality of frame images. 7. The measurement method according to any one of items 1 to 6, further comprising: measuring a biological activity caused by respiration of the subject based on a temperature change in the partial region.

  According to the measurement method described in Item 7, even when there is a possibility that unevenness may occur in the temperature change depending on the observation location, the partial area where the temperature change has occurred can be specified, and the living body caused by the respiration of the subject can be identified. Activity can be measured accurately.

[Item 8]
The image processing apparatus calculates a temperature change for each of a plurality of divided regions included in the region of the mask for each frame image, and calculates a temperature change of a divided region having the largest temperature change among the plurality of divided regions. 7. The measurement method according to any one of items 1 to 6, wherein a biological activity due to respiration of the subject is measured based on the subject.

  According to the measurement method described in Item 8, the efficiency of the arithmetic processing can be improved by using the divided area as a processing unit.

[Item 9]
Analyze the moving image of the subject is placed a mask to cover the nostrils and mouth, a measurement system that measures the biological activity due to the subject's respiration,
The mask is formed of a material whose material temperature is lower than the body temperature of the subject, and whose temperature changes due to the subject's exhalation and inspiration.
An image of the mask placed on the subject, a thermography camera to generate the moving image composed of a plurality of frame images,
An image processing apparatus that receives the moving image, calculates a temperature change in the region of the mask that has occurred over the plurality of frame images, and measures a biological activity due to respiration of the subject based on the temperature change,
A measurement system comprising:

  According to the measurement method described in Item 9, there is provided a measurement system for measuring a living activity caused by respiration of a subject, which is robust to a change in a measurement environment and a physical condition of the subject.

  INDUSTRIAL APPLICABILITY The present invention can be used as a method for non-invasively measuring a living activity of a subject, particularly the number of respirations, by analyzing a moving image obtained by photographing the subject. Further, the present invention can be used as an apparatus, a system, and a computer program for such analysis of a moving image and measurement of life activity.

DESCRIPTION OF SYMBOLS 10, 11 Thermography camera 20 Image processing apparatus 30 Nonwoven fabric mask 31 Nasal cavity expansion tape 32, 33 Member 40 Subject 50 Display 100 Measurement system 201 CPU
202 ROM
203 RAM
204 HDD
205 I / F
206 Image processing circuit

Claims (3)

Thermography camera, and an image processing device that processes a moving image from the thermography camera, using a life activity measurement system including, a measurement method for measuring the life activity caused by the respiration of the subject,
(A) A mask formed of a material whose material temperature is lower than the body temperature of the subject and whose temperature changes by exhalation and inhalation of the subject is arranged so as to cover the nostrils and mouth of the subject. Steps and
(B) the thermographic camera takes an image of the mask placed on the subject, and obtains the moving image composed of a plurality of frame images;
(C) calculating, by the image processing device, a temperature change in the region of the mask, which has occurred over the plurality of frame images, and measures a biological activity due to respiration of the subject based on the temperature change; ,
,
The image processing apparatus calculates a temperature change for each of a plurality of divided regions included in the region of the mask for each frame image, and calculates a temperature change of a divided region having the largest temperature change among the plurality of divided regions. Based on, to measure the biological activity due to the subject's breathing,
Measurement method. In the step (c), the image processing apparatus specifies an area of the mask included in each of the plurality of frame images, and a partial area in the area of the mask where a temperature change occurs over the plurality of frame images. The measurement method according to claim 1, further comprising: measuring a biological activity caused by respiration of the subject based on a temperature change in the partial region. Analyze the moving image of the subject is placed a mask to cover the nostrils and mouth, a measurement system that measures the biological activity due to the subject's respiration,
The mask is formed of a material whose material temperature is lower than the body temperature of the subject, and whose temperature changes due to the subject's exhalation and inspiration.
An image of the mask placed on the subject, a thermography camera to generate the moving image composed of a plurality of frame images,
An image processing apparatus that receives the moving image, calculates a temperature change in the region of the mask that has occurred over the plurality of frame images, and measures a biological activity due to respiration of the subject based on the temperature change,
Equipped with a,
The image processing apparatus calculates a temperature change for each of a plurality of divided regions included in the region of the mask for each frame image, and calculates a temperature change of a divided region having the largest temperature change among the plurality of divided regions. Based on, to measure the biological activity due to the subject's breathing,
Measurement system.

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