JP2020092980A - Respiratory disease discrimination device - Google Patents

Abstract

To discriminate a respiratory disease without use of a mouthpiece.SOLUTION: A respiratory disease discrimination device (S) comprises: first detection means (6) for detecting a distance from the body surface of a subject (3); second detection means (8) which is disposed at a position different from the first detection means (6) and detects a distance from the body surface of the subject (3); respiration measuring means (C3) which measures the respiration (Ac(t)) of the subject except a body motion, on the basis of a result of the detection by the first detection means (6) and a result of the detection by the second detection means (8); and disease discrimination means (C4) which discriminates a respiratory disease of the subject (3), on the basis of a result of a detection by the respiration measuring means (C3).SELECTED DRAWING: Figure 1

Description

The present invention relates to a respiratory disease determining apparatus for determining a subject suffering from a respiratory disease such as COPD (chronic obstructive pulmonary disease).

In recent years, some emerging countries are undergoing rapid air pollution due to economic development. In such countries, respiratory diseases have become a problem, and in particular, the number of patients with chronic obstructive respiratory syndrome (= COPD: Chronic Obstructive Pulmonary Disease) as an example of respiratory diseases is on the rise. is there. Also, some smokers have COPD. No fundamental cure has been established for COPD at present, and it is necessary to detect COPD at an early stage and stop the progression of the disease.

At present, a device called a spirometer is generally used for diagnosing COPD. A spirometer is a device in which a subject holds a tubular mouthpiece with his mouth and blows his breath. A spirometer is used to determine the magnitude of the expiratory volume of breath for one second (=one-second rate), and when the magnitude of the one-second rate is small, it is diagnosed whether or not it is COPD. In addition, a spirometer is used to obtain the relationship (=FV-curve) between the ventilation volume (=F) and the expiratory flow rate (=V) at the time of maximum breathing, and whether COPD or not is diagnosed from the shape. It is also known (Non-Patent Document 1).

O'Donnell DE et.al. “Pathophysiology of dyspnea in chronic obstructive pulmonary disease: a roundtable”, Proc Am Thorac Soc ,2007,4(2):145-68

(Problems of conventional technology)
When the spirometer is used as in the prior art, a mouthpiece is used, and therefore it is essential to have a doctor or a clinical technologist. Therefore, it is difficult to carry out diagnosis and examination with a spirometer only in a hospital, and it is difficult to use it at home or at work. If COPD can be easily screened at home or in the workplace, it may be advisable to have a medical examination for respiratory medicine. It could be done. That is, in order to detect respiratory diseases such as COPD in an early stage, a device that can be used at home, at work, etc. is required.

An object of the present invention is to make it possible to identify a respiratory disease without using a mouthpiece.

In order to solve the technical problem, the respiratory disease determining device according to the invention of claim 1 is
First detection means for detecting a distance from the body surface of the subject;
Second detecting means arranged at a position different from that of the first detecting means and detecting a distance from the body surface of the subject;
Respiration measurement means for measuring the respiration of the subject excluding body movements based on the detection result of the first detection means and the detection result of the second detection means,
Based on the detection result of the respiratory measurement means, a disease determination means for determining a respiratory system disease of the subject,
It is characterized by having.

The invention according to claim 2 is the respiratory system disease determining device according to claim 1,
The first detection means and the second detection means arranged to face each other with the body of the subject in between.
It is characterized by having.

The invention according to claim 3 is the respiratory system disease discrimination device according to claim 1 or 2,
Based on the ratio of the amount of air exhaled in the first second to the forced vital capacity in one breath, the disease determination means for determining the respiratory system disease of the subject,
It is characterized by having.

The invention according to claim 4 is the respiratory system disease determining device according to claim 1 or 2,
By the pattern recognition of the trajectory drawn by the ventilation volume and ventilation rate in breathing, the disease discrimination means for discriminating the respiratory system disease of the subject,
It is characterized by having.

According to the invention described in claim 1, it is possible to determine a respiratory disease without using a mouthpiece.
According to the second aspect of the present invention, when the body movement is removed as compared with the case where the first detection means and the second detection means are not arranged facing each other with the body of the subject interposed therebetween. The calculation can be easily performed.
According to the third aspect of the present invention, the respiratory system disease can be discriminated based on the one second rate.
According to the invention described in claim 4, the respiratory system disease can be identified by the pattern recognition of the FV curve.

1 is an overall explanatory diagram of a respiratory disease determining apparatus according to a first embodiment of the present invention. FIG. 2 is a block diagram (functional block diagram) showing each function of the control unit of the main body according to the first embodiment of the present invention. FIG. 3 is an explanatory diagram of an example of the waveform of the first embodiment, FIG. 3A is an explanatory diagram of the waveform before the arctangent demodulation process, and FIG. 3B is an explanatory diagram of the waveform after the arctangent demodulation process. FIG. 4 is an explanatory diagram of body movement removal according to the embodiment. FIG. 5 is an explanatory diagram of the one second rate. FIG. 6 is an explanatory diagram of the experimental result of the experimental example, and is a graph in which the horizontal axis shows the measurement result by the apparatus of Example 1 and the vertical axis shows the measurement result by the conventional spirometer. FIG. 7 is an explanatory diagram of a modified example, FIG. 7A is an explanatory diagram of an FV curve of an example of a healthy person, and FIG. 7B is an explanatory diagram of an FV curve of an example of a COPD patient.

Next, specific examples of the embodiments of the present invention (hereinafter referred to as examples) will be described with reference to the drawings, but the present invention is not limited to the following examples.
In the following description using the drawings, illustrations other than the members necessary for the description are appropriately omitted for easy understanding.

1 is an overall explanatory diagram of a respiratory disease determining apparatus according to a first embodiment of the present invention.
In FIG. 1, a respiratory disease determining apparatus S according to a first embodiment of the present invention includes a measuring apparatus 1 that measures biological information of a human (subject) as an example of a subject. The measuring device 1 has a main body 2 in which an information processing device (=computer device) including a power supply device, an electric circuit, and the like (not shown) is incorporated.

A display 4 as an example of a display unit is provided on the front surface of the main body 2. As an example, the display 4 of the first embodiment is configured by a touch panel that can be touched with a finger for input, and the display 4 serves both as an information display unit and an input unit. Therefore, the display 4 can use a commercially available tablet terminal.

A first Doppler radar 6 as an example of a first detecting unit is arranged at a position facing the chest of the subject 3 on the lower portion of the front surface of the main body 2. A second Doppler radar 8 as an example of a second detecting unit is arranged on the backrest 7a of the chair 7 on which the subject 3 sits. In the first embodiment, the first Doppler radar 6 and the second Doppler radar 8 are arranged at the same height, and when the subject 3 sits on the chair 7 and faces the display 4, the first Doppler radar 6 6 and the second Doppler radar 8 are arranged so as to face each other.

As an example, each of the Doppler radars 6 and 8 of the first embodiment uses a Doppler sensor having a wavelength λ=12.5 mm, 24 GHz, and 10 mW. Further, the Doppler radars 6 and 8 use those capable of detecting I channel and Q channel signals which are orthogonal to each other. Therefore, each of the Doppler radars 6 and 8 irradiates the chest of the subject 3 with microwaves and measures the reflected wave from the chest to measure the fluctuation of the chest according to the breath of the subject 3. It is configured to be discoverable. In addition, the frequency band and the sensor are not limited to the illustrated configuration, and can be changed to any configuration capable of acquiring the fluctuation of the chest. For example, by using a sensor such as a TOF (=Time of Flight) sensor that measures a distance from an image, it is possible to measure the fluctuation of the chest according to respiration by measuring the distance from the sensor to the chest. is there. Further, it is not limited to the case where the two detection means are configured by the Doppler radars 6 and 8, and one change may be configured by the Doppler radar and the other may be configured by the TOF sensor.

(Explanation of the control unit of the main body unit 2 of the first embodiment)
FIG. 2 is a block diagram (functional block diagram) showing each function of the control unit of the main body according to the first embodiment of the present invention.
In FIG. 2, the control unit of the computer device built in the main unit 2 is an I/O (input/output interface) for inputting/outputting signals to/from the outside and adjusting the input/output signal level, and for performing necessary processing. ROM (Read Only Memory) in which the programs and data are stored, RAM (Random Access Memory) for temporarily storing necessary data, programs stored in storage media such as hard disk, flash memory, ROM, etc. It has a CPU (central processing unit) for performing the corresponding processing, a clock oscillator, and the like.
The computer device configured as described above can realize various functions by executing a program stored in a hard disk, a flash memory, a ROM, or the like.

(Signal output element connected to computer device)
Output signals from signal output elements such as the display 4 and the Doppler radars 6 and 8 are input to the computer device.

(Controlled element connected to computer device)
The computer device is connected to the display 4 and other control elements (not shown) and outputs a control signal to each control element.

(Function of Respiratory Disease Discrimination Program AP1)
The respiratory disease determination program AP1 has the following functional means (program module).
C1: First Fluctuation Measuring Means The first fluctuation measuring means C1 measures the fluctuation of the chest due to the breathing of the subject 3 based on the measurement result of the first Doppler radar 6. The first variation measuring means C1 of the first embodiment has a filter processing means C1A and an arctangent demodulation processing means C1B. The first variation measuring means C1 of the first embodiment measures the waveform of the temporal variation (so-called profile) of the measurement result in the input signal of the first Doppler radar 6.

C1A: Filter Processing Means The filter processing means C1A performs processing of a bandpass filter that passes a signal of 0.015 to 40 Hz from the waveform of the input signal of the first Doppler radar 6. That is, low-frequency noise of less than 0.015 Hz and high-frequency noise of greater than 40 Hz are removed.

FIG. 3 is an explanatory diagram of an example of the waveform of the first embodiment, FIG. 3A is an explanatory diagram of the waveform before the arctangent demodulation process, and FIG. 3B is an explanatory diagram of the waveform after the arctangent demodulation process.
C1B: Arc tangent demodulation processing means The arc tangent demodulation processing means C1B performs arc tangent demodulation processing on the signal of the waveform processed by the filter processing means C1A. As shown in FIG. 3A, when the subject 3 consciously breathes with maximum effort (=during forced breathing), a plurality of peaks are included in the radar waveform observed by the first Doppler radar 6. That is, a waveform as if breathing multiple times may be observed. When the subject 3 makes the same movement as the wavelength λ=12.5 mm of the first Doppler radar 6, the fluctuation during breathing is Vi, the movement of the object is z(=λ), and the fixed phase is θ1. It can be seen that the waveform has two cycles as shown in the following equation.
Vi=sin(4π×z/λ+θ1)
=sin(4π+θ1)
In particular, during effort breathing, so-called deep breathing, body movements such as inhaling air (moving backward) and exhaling air (moving downward) are likely to be naturally accompanied, and the subject 3 should try not to move. However, the subject 3 tends to move. Therefore, a plurality of peaks may be measured in one breath as shown in FIG. 3A.

The arctangent demodulation processing means C1B of the first embodiment uses the I-channel and Q-channel signals detected by the first Doppler radar 6 to perform arctangent demodulation processing. In the first embodiment, when the output signal of the I channel is BI(t), the output signal of the Q channel is BQ(t), and the distance from the sensor is p1(t), the following formula (1) is used. Performs arctangent processing.
A(t)=arctan(BQ(t)/BI(t))
=arctan(sin(θ1+p1(t))/cos(θ1+p1(t))
=θ1+p1(t) Equation (1)
Note that p1(t)=4πvt/λ. Therefore, the formula (1) becomes a graph as shown in FIG. 3B, and only the movement of the chest of the subject 3 who is the target can be extracted.

C2: Second fluctuation measuring means The second fluctuation measuring means C2 measures the fluctuation of the chest due to the breathing of the subject 3 based on the measurement result of the second Doppler radar 8. The second fluctuation measuring means C2 also has a filter processing means C2A and an arctangent demodulation processing means C2B, like the first fluctuation measuring means C1. It should be noted that the second fluctuation measuring means C2 differs from the first fluctuation measuring means C1 only in whether the input signal is from the first Doppler radar 6 or the second Doppler radar 8. Since the same processing is performed, detailed description will be omitted.

FIG. 4 is an explanatory diagram of body movement removal according to the embodiment.
C3: Body Movement Removing Means A body movement removing means C3, which is an example of a respiration measuring means, measures respiration from which body movements have been removed based on the detection results of the first variation measuring means C1 and the second variation measuring means C2. .. The body movement removing means C3 of the first embodiment derives the movement due to respiration from the chest movements A1(t) and A2(t) calculated by the fluctuation measuring means C1 and C2. Here, in the measurement results z1(t) and z2(t) of the movement of the target (=subject 3) by the Doppler radars 6 and 8, the movements due to respiration are x1(t) and x2(t), If the movement due to body movement is y(t), the respiratory component Ac(t) is derived from the following equation (2).
A1(t)=4πx1(t)/λ+4πy(t)/λ+θ1
A2(t)=4πx2(t)/λ-4πy(t)/λ+θ1
Ac(t)=A1(t)+A2(t)
=4π{x1(t)+x2(t)}/λ+θ1+θ2 Equation (2)

That is, during breathing, the lungs take air into and out of the lungs, so that the body of the subject 3 is inflated and deflated. Therefore, when inflated, the distances between the both Doppler radars 6, 8 are close to the chest and the back, and when deflated, the distances between the both Doppler radars 6, 8 are long. Therefore, in the measurement results A1(t) and A2(t) obtained by the two Doppler radars 6 and 8, the respiratory components x1(t) and x2(t) included in the measurement results are in phase.
On the other hand, during the body movement, the body of the subject 3 bends or leans back. Therefore, when bending down, the first Doppler radar 6 approaches the chest and the second Doppler radar 8 moves farther away from the back. Therefore, in the measurement results A1(t) and A2(t) by the two Doppler radars 6 and 8, the body movement component y(t) has an opposite phase.
Therefore, by combining the observation results of the two Doppler radars 6 and 8, the body motion component can be canceled and only the respiratory component Ac(t) can be derived.

C4: Disease Discriminating Means The disease discriminating means C4 has a smoothing means C4A and a one-second rate calculating means C4B, and is based on the respiratory component Ac(t) derived by the body movement removing means C3. 3. Respiratory diseases are identified. The smoothing means C4A smoothes the waveform from the moving average of the waveform.

FIG. 5 is an explanatory diagram of the one second rate.
The one-second rate calculating means C4B derives the one-second rate, which is the ratio of the amount of air exhaled in the first second to the forced vital capacity in one breath. In FIG. 5, the one-second rate calculating unit C4B of the first embodiment sets the one having the largest peak-to-peak width in the waveform of the respiratory component Ac(t) as the forced vital capacity (=FVC), and the first one second from the apex. The amount of air discharged (=FEV1.0) is calculated, and FEV1.0%=FEV1.0/FVC is derived as a one-second rate.
Then, the disease determining means C4 of the first embodiment diagnoses COPD when the one-second rate FEV1.0% is, for example, less than 70%.

(Operation of Example 1)
The respiratory disease determining apparatus S according to the first embodiment having the above configuration is tested by the first Doppler radar 6 in front of the subject 3 and the second Doppler radar 8 installed on the backrest 7a of the chair 7. The movement of the person 3 is detected without contact. Then, the body motion component is removed, the respiratory component Ac(t) is derived, and the diagnosis of COPD is performed. Therefore, COPD can be diagnosed more easily than when a conventional spirometer that holds a mouthpiece is used. Therefore, it is not necessary to have a doctor or a clinical laboratory technician to meet with each other, and can be installed in a home or a workplace. Therefore, it is possible to easily examine respiratory diseases such as COPD at home or in the office without going to the hospital, which leads to early detection of diseases.
Further, since it is possible to make a contactless diagnosis by simply sitting on the chair 7, the physical and psychological burden on the subject 3 is less than that of the spirometer holding the mouthpiece.

(Experimental example)
Next, an experiment was conducted to confirm the effect of Example 1.
In the experiment, five healthy male university students were forced to breathe once for 20 seconds while holding the spirometer, and while measuring the 1-second rate with the spirometer, at the same time, the respirator of Example 1 was used. The one-second rate was also measured by the system disease determination device S. This measurement was performed twice each.
In addition, in order to reproduce a COPD patient in a pseudo manner, the straw is attached to the mouthpiece portion of the spirometer and sealed, and the straw is held. That is, since the trajectory of the COPD patient becomes narrow due to bronchitis, it is possible to simulate the COPD patient by using a straw. Results are shown in FIG.

FIG. 6 is an explanatory diagram of the experimental results of the experimental example, and is a graph in which the horizontal axis represents the measurement result of the apparatus of Example 1 and the vertical axis represents the measurement result of the conventional spirometer.
As shown in FIG. 6, a strong correlation was obtained between the healthy person and the pseudo COPD model, and the correlation coefficient was 0.93. Therefore, it was confirmed that the respiratory disease determining apparatus S of Example 1 can diagnose a COPD patient with the same accuracy as that of the conventional spirometer.

(Example of change)
FIG. 7 is an explanatory diagram of a modified example, FIG. 7A is an explanatory diagram of an FV curve of an example of a healthy person, and FIG. 7B is an explanatory diagram of an FV curve of an example of a COPD patient.
In the first embodiment, the disease discrimination means C4 discriminates the disease using the one-second rate, but the present invention is not limited to this. With respect to the waveform of the respiratory component Ac(t), that is, the ventilation rate obtained by differentiating the ventilation rate with respect to the change over time of the ventilation rate is derived, and the vertical axis indicates the ventilation rate and the horizontal axis indicates the ventilation rate. A Flow-Volume curve (FV curve) that is a locus drawn by the ventilation volume (=Volume) and the ventilation rate (=Flow) in breathing as shown in FIG. 7 is derived. As shown in FIG. 7, the FV curve has a remarkable difference between a healthy person and a COPD patient. That is, although a healthy person is relatively close to a circle, a COPD patient tends to have a small cross-sectional area of the trachea and a high flow rate even at the same flow rate due to the obstruction of the trachea at the end. , The shape tends to be biased toward the side with large ventilation. Therefore, it is also possible to determine the disease of the respiratory system of the subject 3 by deriving the FV curve and recognizing the pattern of the FV curve. Note that it is also possible to discriminate the disease by using both the one second rate and the pattern recognition of the FV curve.

(Other modifications)
Although the embodiments and modifications of the present invention have been described in detail above, the present invention is not limited to the above-mentioned embodiments and modifications, and within the scope of the gist of the present invention described in the claims. It is possible to make various changes. Modifications (H01) to (H05) of the present invention are exemplified below.
(H01) In the above-described embodiment, the subject is a human, but the present invention is not limited to this, and the present invention can be applied to other living bodies such as animals.
(H02) The specific numerical values exemplified in the above embodiment can be appropriately changed according to the individual difference of the equipment, the measurement environment, the design, the specifications, and the like.

(H03) In the above embodiment, the two Doppler radars 6 and 8 are arranged in front of and behind the subject 3, that is, at a position shifted by 180° about the subject 3 when viewed from above. It is desirable, but not limited to this. It is possible to set the position to be displaced by 90° or 45° with respect to the subject 3. At this time, the equation (2) needs to be synthesized not according to the simple addition but according to the angles of the two installed Doppler radars 6 and 8.

(H04) In the above-described embodiment, the case where two Doppler radars 6 and 8 are installed has been exemplified, but the present invention is not limited to this, and it is also possible to provide three or more.
(H05) Although COPD is exemplified as the disease to be diagnosed in the above-mentioned examples, the present invention is not limited to this. For example, it is expected to be utilized for the diagnosis of bronchitis, bronchial asthma, etc., which can be diagnosed by respiration such as difficulty breathing during illness.

3... Examinee,
6... First detecting means,
8...Second detecting means,
Ac(t)... breathing,
C3... Respiratory measurement means,
C4... Disease discrimination means,
S... Respiratory disease determination device.

Claims (4)

First detection means for detecting a distance from the body surface of the subject;
Second detecting means arranged at a position different from that of the first detecting means and detecting a distance from the body surface of the subject;
Respiration measurement means for measuring the respiration of the subject excluding body movements based on the detection result of the first detection means and the detection result of the second detection means,
Based on the detection result of the respiratory measurement means, a disease determination means for determining a respiratory system disease of the subject,
A respiratory system disease discriminating apparatus comprising: The first detection means and the second detection means arranged to face each other with the body of the subject in between.
The respiratory system disease discrimination device according to claim 1, further comprising: Based on the ratio of the amount of air exhaled in the first second to the forced vital capacity in one breath, the disease determination means for determining the respiratory system disease of the subject,
The respiratory system disease discriminating apparatus according to claim 1 or 2, further comprising: By the pattern recognition of the trajectory drawn by the ventilation volume and ventilation rate in breathing, the disease discrimination means for discriminating the respiratory system disease of the subject,
The respiratory system disease discriminating apparatus according to claim 1 or 2, further comprising: