Expiration sensor, gas sensor, and expiration detection method

Abstract

The present invention relates to an exhalation sensor, a gas sensor, and an exhalation detection method. It is preferable to correct the influence of disturbances in a measurement. An exhalation sensor for detecting exhalation generated by respiration, the exhalation sensor being provided with: a light-emitting unit for irradiating light toward a path through which the exhalation passes; a first light-receiving unit that receives at least a portion of the light emitted by the light-emitting unit and outputs a first light-receiving signal corresponding to a light-receiving result; and a calculation unit that calculates a baseline for a waveform on the basis of a frequency component lower than a set first cut-off frequency of the first light reception signal, and detects expiration on the basis of a signal obtained by removing the baseline from the first light reception signal, said calculation unit calculating the first light reception signal.

Description

Technical Field

[0001] The invention relates to an exhalation sensor, a gas sensor and an exhalation detection method. Background Art

[0002] Conventionally, there is known a measuring device for measuring respiratory gas, gas concentration, or respiratory rate (for example, see Patent Documents 1 to 3).

[0003] Patent Literature

[0004] Patent Document 1: Japanese Patent No. 5351583

[0005] Patent Document 2: Japanese Patent Application Publication No. 2022-3321

[0006] Patent Document 3: Japanese Patent No. 3627243 Summary of the invention

[0007] Problem that the invention aims to solve

[0008] In the assay, it is preferable to correct for the effects of interferences.

[0009] Solutions for solving problems

[0010] In a first aspect of the present invention, an exhalation sensor for detecting exhalation generated by breathing is provided. The exhalation sensor includes: a light emitting unit that radiates light toward a path through which exhalation passes; a first light receiving unit that receives at least a portion of the light radiated by the light emitting unit and outputs a first light receiving signal corresponding to the light receiving result; and a calculation unit that calculates the first light receiving signal. The calculation unit calculates a baseline of a waveform based on a frequency component of the first light receiving signal that is lower than a set first cutoff frequency, and detects exhalation based on a signal obtained by removing the baseline from the first light receiving signal.

[0011] The calculation unit may calculate at least one of a cycle and a length of breathing.

[0012] In any of the above breath sensors, the first cutoff frequency may be set according to a change in a signal value of the first light receiving signal.

[0013] In any of the above-mentioned exhalation sensors, the calculation unit can set the first cutoff frequency when the signal value of the object serving as the calculation baseline value of the first light receiving signal increases relative to the past signal value in the time waveform of the first light receiving signal to be higher than the first cutoff frequency when the signal value of the object serving as the calculation baseline value decreases relative to the past signal value.

[0014] In any of the above-mentioned exhalation sensors, the operation unit can set the first cutoff frequency when the signal value of the object serving as the calculation baseline value of the first light receiving signal increases by more than 20% relative to the past signal value in the time waveform of the first light receiving signal to be higher than the first cutoff frequency when the signal value of the object serving as the calculation baseline value decreases by more than 20% relative to the past signal value.

[0015] In any of the above-mentioned exhalation sensors, the operation unit can set the first cutoff frequency when the signal value of the object serving as the calculation baseline of the first light receiving signal increases relative to the signal value at the immediately previous moment in the time waveform of the first light receiving signal to be more than 10 times higher than the first cutoff frequency when the signal value of the object serving as the calculation baseline value decreases relative to the immediately previous signal value.

[0016] In any of the above-mentioned exhalation sensors, the operation unit can set the first cutoff frequency when the signal value of the object serving as the calculation baseline of the first light receiving signal increases by more than 20% relative to the signal value at the immediately previous moment in the time waveform of the first light receiving signal to be more than 10 times higher than the first cutoff frequency when the signal value of the object serving as the calculation baseline value decreases by more than 20% relative to the immediately previous signal value.

[0017] In any of the above breath sensors, the first cutoff frequency may be below 3 Hz.

[0018] Any of the above breath sensors may further include a second light receiving unit that receives light that does not pass through a path through which breath passes among the light emitted by the light emitting unit and outputs a second light receiving signal corresponding to the light receiving result. The computing unit may correct the first light receiving signal based on a signal value of the second light receiving signal.

[0019] In any of the above breath sensors, the calculation unit may generate the corrected first light receiving signal using a frequency component of the second light receiving signal lower than a set second cutoff frequency and a frequency component of the first light receiving signal lower than a set third cutoff frequency. The second cutoff frequency may be lower than the third cutoff frequency.

[0020] Any breath sensor may further include an optical filter disposed on an optical path of light between the light emitting unit and the first light receiving unit and configured to limit a wavelength of light incident on the first light receiving unit.

[0021] In a second aspect of the present invention, a gas sensor for detecting a detection target gas is provided. The gas sensor comprises: a light emitting unit that irradiates light toward a path through which the detection target gas passes; a first light receiving unit that receives at least a portion of the light irradiated by the light emitting unit and outputs a first light receiving signal corresponding to the light receiving result; and a calculation unit that calculates the first light receiving signal. The calculation unit calculates the baseline of the waveform of the first light receiving signal based on the frequency component of the first light receiving signal that is lower than the set first cutoff frequency, and detects the detection target gas based on the signal obtained by removing the baseline from the first light receiving signal.

[0022] In a third aspect of the present invention, there is provided an exhalation detection method for detecting exhalation generated by breathing. The exhalation detection method includes the following steps: a light emitting step, in which a light emitting unit irradiates light toward a path through which exhalation passes; a first light receiving step, in which a first light receiving unit receives at least a portion of the light irradiated in the light emitting step; a first output step, in which the first light receiving unit outputs a first light receiving signal corresponding to the light receiving result in the first light receiving step; and a calculation step, in which a calculation unit calculates the first light receiving signal output in the first output step. The calculation step includes the following steps: a calculation step, in which a calculation unit calculates a baseline of a waveform of the first light receiving signal based on a frequency component of the first light receiving signal that is lower than a set first cutoff frequency; and a detection step, in which the calculation unit detects exhalation based on a signal obtained by removing the baseline calculated in the calculation step from the first light receiving signal.

[0023] In addition, the above summary of the invention does not list all the necessary features of the present invention. In addition, sub-combinations of these feature groups can also constitute inventions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a diagram showing an example of a breath sensor 10 according to an embodiment of the present invention.

[0025] Figure 2 It is a diagram showing an example of signal processing.

[0026] Figure 3 This is a diagram showing an example of calculation of a baseline.

[0027] Figure 4A This is a diagram showing an example of a result obtained by using a fixed first cutoff frequency in the baseline calculation.

[0028] Figure 4B It shows that according to Figure 4A A diagram showing an example of a determination signal obtained by taking the difference between the received light signal ratio and the baseline calculated value.

[0029] Figure 5AThis is a diagram showing an example of a result obtained by changing the first cutoff frequency in accordance with the magnitude relationship of the immediately preceding signal value in the baseline calculation.

[0030] Figure 5B It shows that according to Figure 5A Graph showing an example of a judgment signal calculated by light reception signal ratio and baseline.

[0031] Fig. 6A This is a diagram showing an example of a case where signal processing is performed on the first light reception signal and the second light reception signal using the same cutoff frequency.

[0032] Figure 6B It shows that according to Fig. 6A FIG. 1 is a diagram showing an example of a light receiving signal ratio calculated between a first light receiving signal and a second light receiving signal.

[0033] Fig. 7A This is a diagram showing an example of a case where signal processing is performed on the first light reception signal and the second light reception signal using different cutoff frequencies, respectively.

[0034] Figure 7B It is shown Fig. 7A A diagram showing an example of a ratio of a first light receiving signal to a second light receiving signal.

[0035] Figure 8 This is a diagram showing another example of the breath sensor 10 according to the embodiment of the present invention.

[0036] Fig.9A 1 is a diagram showing a configuration example of the light emitting unit 16 .

[0037] Fig. 9B This is a diagram showing an example of a gas sensor 11 according to an embodiment of the present invention.

[0038] Fig.10 1 is a flowchart showing an example of a breath detection method according to an embodiment of the present invention.

[0039] Fig.11 1 is a flowchart showing another example of the breath detection method according to one embodiment of the present invention.

[0040] Fig.12 1 is a schematic diagram showing an example of a breath detection system 100 according to an embodiment of the present invention.

[0041] Fig.13 2 is a functional block diagram showing an example of the breath detection system 100 .

[0042] Fig.14 1 is a diagram showing an example of a state of the main body 102 .

[0043] Fig.15 1 is a diagram showing another example of the state of the main body 102 .

[0044] Fig.16 2 is a diagram showing a configuration example of the state detection unit 150 .

[0045] Fig.17 This is a diagram showing an example of a display device 300 according to an embodiment of the present invention.

[0046] Fig.18 1 is a diagram showing an example of an operator 310 on the display unit 210 .

[0047] Fig.19 It is a block diagram showing an example of a display device 300 according to an embodiment of the present invention.

[0048] Fig. 20 This is a diagram showing an example of a situation in which an operator 310 is using a device 400 .

[0049] Fig.21 : is a diagram showing an example of the relationship between the CO 2 (carbon dioxide) concentration in the exhaled air of the operator 310 and the exhaled air volume of the operator 310 .

[0050] Fig. 22 This is a flowchart showing an example of a display method according to an embodiment of the present invention.

[0051] Fig.23 1 is a diagram showing an example of a computer 2200 that can embody the breath detection system 100 or the display device 300 according to an embodiment of the present invention in whole or in part. DETAILED DESCRIPTION

[0052] The present invention is described below by the embodiments of the invention, but the following embodiments do not limit the invention involved in the claims. In addition, the combination of features described in the embodiments may not all be necessary for the solution of the invention. In this specification, the same parts in each figure are marked with the same figure numbers, and the description is sometimes omitted. In addition, for the convenience of description, a part of the structure is sometimes not illustrated.

[0053] In this specification, sometimes the orthogonal coordinate system of the X-axis, Y-axis and Z-axis is used to explain technical matters. The orthogonal coordinate system only determines the relative position of the components and does not limit the specific direction. For example, the Z-axis direction is not limited to the height direction relative to the ground.

[0054] Figure 11 is a diagram showing an example of a breath sensor 10 according to an embodiment of the present invention. The breath sensor 10 detects breath produced by breathing. The breath sensor 10 includes a light emitting unit 16, a first light receiving unit 18, and a computing unit 20. The light emitting unit 16, the first light receiving unit 18, and the computing unit 20 can be mounted on a supporting member 30. In this example, the light emitting unit 16 is mounted on one of the supporting members 30 facing each other, and the first light receiving unit 18 and the computing unit 20 are mounted on the other supporting member 30. In this example, the plane parallel to the main surface of the supporting member 30 is set as the XY plane, and the direction perpendicular to the main surface of the supporting member 30 is set as the Z-axis direction for description.

[0055] The breath sensor 10 is an NDIR (non-dispersive infrared) sensor that uses the unique absorption wavelength of carbon dioxide contained in the breath. The light emitting unit 16 irradiates light 14 toward the path 12 through which the breath passes. As an example, the light emitting unit 16 is an IR-LED. The light 14 can be infrared light or light containing at least the absorption wavelength of carbon dioxide. A portion of the light 14 passes through the path 12 and is incident on the first light receiving unit 18. A portion of the light 14 is incident on the second light receiving unit 22 described later.

[0056] The first light receiving unit 18 receives at least a part of the light 14 emitted by the light emitting unit 16, and outputs a first light receiving signal according to the light receiving result to the calculation unit 20. As an example, the first light receiving unit 18 is a photodiode.

[0057] The calculation unit 20 calculates the first light receiving signal. As an example, the calculation unit 20 is an IC. Since carbon dioxide absorbs the light 14 and the amount of light received at the absorption wavelength of carbon dioxide decreases, the calculation unit 20 can calculate the concentration of carbon dioxide or a value corresponding to the concentration based on the first light receiving signal.

[0058] The breath sensor 10 may further include a thermometer. The calculation unit 20 may receive temperature information of the breath sensor 10 from the thermometer. By correcting the first light receiving signal based on the temperature information, the calculation unit 20 may more accurately calculate the concentration of carbon dioxide or a value corresponding to the concentration based on the first light receiving signal.

[0059] The breath sensor 10 may further include a second light receiving unit 22. The structure of the light emitting unit 16 and the second light receiving unit 22 will be described later. The second light receiving unit 22 receives the light 14 emitted by the light emitting unit 16 that does not pass through the path 12 through which the breath passes, and outputs a second light receiving signal corresponding to the light receiving result. The second light receiving signal may be output to the operation unit 20. The operation unit 20 may use the signal value of the second light receiving signal to correct the first light receiving signal. The operation unit 20 may generate a signal obtained by dividing the signal value of the first light receiving signal by the signal value of the second light receiving signal as a detection signal. By providing the second light receiving unit 22, it is possible to correct output changes caused by changes in the amount of light of the light emitting unit 16 and temperature.

[0060] The breath sensor 10 may further include an optical filter 24 disposed on the optical path of the light 14 between the light emitting unit 16 and the first light receiving unit 18. The optical filter 24 of this example is provided on the surface of the first light receiving unit 18. The optical filter 24 is used to limit the wavelength of the light 14 incident on the first light receiving unit 18. As an example, the optical filter 24 is a bandpass filter.

[0061] Generally speaking, the sensitivity of the first light receiving unit 18 changes due to the influence of temperature. In a sensitivity curve in which the horizontal axis is the wavelength of light and the vertical axis is the sensitivity of the first light receiving unit 18, the influence of temperature is manifested as a shift of the sensitivity curve in the horizontal axis direction. On the other hand, the sensitivity curve has a wavelength region in which the sensitivity value is almost flat. By using the optical filter 24 to allow only light of the wavelength region to be incident on the first light receiving unit 18, even if the temperature of the first light receiving unit 18 changes, the influence on the sensitivity can be suppressed.

[0062] Figure 2 2 is a diagram showing an example of signal processing in the computing unit 20. Figure 2 In the following figures, the first light receiving signal is represented by IR1 and the second light receiving signal is represented by IR2. Figure 2 The horizontal axis represents time, and the vertical axis represents the value of the ratio of the intensity of the first light receiving signal to the second light receiving signal. In this specification, the ratio of the intensity of the first light receiving signal to the second light receiving signal is sometimes referred to as the light receiving signal ratio. In addition, the intensity of the first light receiving signal is sometimes referred to as the first light receiving signal, and the intensity of the second light receiving signal is sometimes referred to as the second light receiving signal. As described above, by dividing the first light receiving signal by the second light receiving signal, the output variation caused by the change in the light amount of the light emitting unit 16 and the temperature can be corrected.

[0063] Here, the first and second light receiving signals may be values ​​corrected according to the temperature information in the calculation unit 20. As long as the first and second light receiving units 18 and 22 do not have the same characteristics, output fluctuations can be corrected more accurately by temperature correcting the light receiving signals.

[0064] In the subsequent figures, the light receiving signal ratio of the first light receiving signal and the second light receiving signal is also used to illustrate the implementation method, but the use of the second light receiving signal is not necessary. The signal value of the first light receiving signal can also be used instead of the light receiving signal ratio. In this case, the expression "light receiving signal ratio" can be replaced by "first light receiving signal". In this specification, even if the light receiving signal ratio is processed, the first light receiving signal can be processed in the same way, and even if the first light receiving signal is processed, the light receiving signal ratio can be processed in the same way.

[0065] The calculation unit 20 obtains the ratio of the input first light receiving signal to the second light receiving signal, and performs signal processing on the light receiving signal ratio. Figure 2 In the figure, noise removal is performed. The dotted line in the figure represents the light receiving signal ratio before noise removal, and the solid line represents the light receiving signal ratio after noise removal. As an example, the operation unit 20 performs noise removal through a low-pass filter. Since the amount of light received by the first light receiving unit 18 decreases due to the absorption of carbon dioxide, the light receiving signal ratio decreases when exhalation is detected. In addition, since the exhalation diffuses rapidly in the air, the light receiving signal ratio increases (recovers) immediately after the decrease. The change in the light receiving signal ratio from 10 seconds to 20 seconds in the figure corresponds to breathing. A valley-shaped portion in the light receiving signal ratio corresponds to one breath. In Figure 2 In the example of , five valley-shaped portions appear in the waveform of the light reception signal ratio, thus showing the light reception signal ratios in five breaths.

[0066] Figure 3 This is a diagram showing an example of calculation of a baseline. Figure 3 The axes and Figure 2 The solid line in the figure represents the light receiving signal ratio after noise processing. The calculation unit 20 calculates the baseline of the waveform of the first light receiving signal based on the light receiving signal ratio. The dotted line in the figure represents the calculated baseline.

[0067] The baseline is a signal waveform based on factors other than carbon dioxide contained in the exhaled breath (interference). Figure 3 A waveform obtained by reducing or removing the component based on the concentration of carbon dioxide from the waveform shown by the solid line. The baseline may include a component of the intensity of the light 14 irradiated by the light emitting unit 16 and a variable component caused by factors other than the change in the concentration of carbon dioxide. When the exhalation sensor 10 detects exhalation, the temperature of the light emitting unit 16 and the first light receiving unit 18 changes according to the temperature of the exhaled breath, and the characteristics sometimes change. The baseline may be a signal waveform that includes the influence of such characteristic changes and does not include the influence of carbon dioxide. The baseline based on the interference of the frequency deviation from the breathing cycle may also include the influence of humidity, component degradation, etc., but in this specification, it is assumed to mainly include changes caused by the temperature of the exhaled breath.

[0068] The calculation unit 20 can calculate the baseline based on the light reception signal ratio. Since the light reception signal ratio is correlated with the influence of temperature due to exhalation, the influence of temperature due to exhalation can be appropriately reflected by using the light reception signal ratio. Figure 3 The baseline calculation value is calculated based on the light receiving signal ratio, so it changes according to the breathing cycle, which shows the influence of temperature caused by exhalation. The parameters in the baseline calculation can be determined by experiments in a way that shows the change of the light receiving signal ratio caused by factors other than carbon dioxide. As an example, the parameter is the coefficient b0 described later.

[0069] The calculation unit 20 can calculate the baseline by removing the frequency component of the interference whose frequency deviates from the breathing cycle from the time waveform of the light receiving signal ratio. As an example, the calculation unit 20 calculates the baseline by filtering represented by infinite impulse response (IIR (Infinite Impulse Response)). Table 1 shows an example of the process of baseline calculation in IIR filtering.

[0070] [Table 1]

[0071] x0 y0=x0 x1 y1=x1×b0+y0×(1-b0) x2 y2=x2×b0+y1×(1-b0) x3 y3=x3×b0+y2×(1-b0)

[0072] In the table, x represents the signal value of the light receiving signal ratio, and y represents the calculated value of the baseline. b0 is a filter coefficient. The numbers after x and y represent the sampling point n. Table 1 shows that n=3.

[0073] The calculation unit 20 calculates the value yn of the baseline for each signal value xn of the light receiving signal ratio. As shown in Table 1, the calculated value yn of the baseline is calculated by summing the value obtained by multiplying the corresponding signal value xn by the coefficient b0 and the value obtained by multiplying the calculated value yn-1 of the previous baseline by (1-b0). In other words, the coefficient b0 determines the proportion in which the value of the corresponding signal value is reflected relative to the calculated value of the previous baseline. The coefficient b0 takes a value greater than 0 and less than 1. When the coefficient b0 is increased, the value of the corresponding signal value is further reflected, and the baseline easily follows the changes in the signal value. In the example of Table 1, the calculated value yn of the baseline reflects the value of the previous baseline yn-1, but in other examples, the calculated value yn of the baseline may also reflect the values ​​of the previous multiple baselines.

[0074] The calculation unit 20 can calculate the baseline by using the moving average filter (MA: Moving Average) shown in the following formula 1. In formula 1, Y n is the calculated value, X n is the signal value, M is the number of intervals, F s is the sampling frequency, f cis the cutoff frequency. In the calculation method based on the moving average, the calculation unit 20 calculates the average value for each certain interval so that the intervals are shifted. The number of intervals M is the number of the intervals.

[0075] [Number 1]

[0076]

[0077] The calculation unit 20 can calculate the baseline by using the weighted moving average filter (WMA) shown in the following formula 2. In formula 2, W i is the weight. As in Formula 1, M is the number of intervals.

[0078] [Number 2]

[0079]

[0080] The calculation unit 20 can calculate the baseline by using a finite impulse response filter (FIR) as shown in the following equation 3. In equation 3, bi is a filter coefficient. As in equation 1, M is the number of intervals.

[0081] [Number 3]

[0082]

[0083] The calculation unit 20 can calculate the baseline by a Butterworth filter as shown in the following equation 4. In equation 4, N is the filter order, and s is the complex frequency in the Laplace transform. When σ is the real part, ω is the frequency, and j is the imaginary unit, s is represented by the sum of σ and jω.

[0084] [Number 4]

[0085]

[0086] The calculation unit 20 can calculate the baseline based on the signal value when the signal change is small during the predetermined period. The case where the signal change is small refers to data of the time when no breathing occurs, etc. The predetermined period is, for example, Figure 2 During the 5 breaths.

[0087] At least one of an upper limit and a lower limit may be set for the baseline. Which of Table 1 and Formulas 1 to 4 is used to calculate the baseline may be changed according to the signal value or the ambient temperature.

[0088] Here, the calculation of the immediately preceding baseline is not limited to calculating the baseline of xn through xn-1. Any baseline calculation method that is difficult to track the breathing signal will suffice. For example, for xn, m can be set to a natural number, and the baseline calculation is performed using all signals from xn-1 to the earlier data xn-m. For example, if data is acquired every 0.1 seconds, m=3 can be set, and the baseline calculation of the signal xn is performed using the data of the signals xn-1, xn-2, and xn-3. The immediately preceding range can be determined in a manner that makes it difficult to track the breathing signal but can track slower temperature changes. The baseline calculation can be based on the ratio of the light-receiving signals before Tn, or it can be based on the ratio of the light-receiving signals in a specific period before Tn that is shorter than the breathing cycle.

[0089] The calculation unit 20 removes the baseline from the light receiving signal ratio. The baseline removal may be obtained by subtracting the baseline value at each moment from the signal value at that moment. By calculating and removing the baseline, changes in the signal value caused by factors other than carbon dioxide contained in the exhaled breath can be corrected, thereby enabling more accurate measurement. In this specification, the signal after the baseline is removed from the light receiving signal ratio is sometimes referred to as a determination signal.

[0090] The operation unit 20 detects exhalation based on the determination signal. When the value of the determination signal is lower than the determination threshold, the operation unit 20 can determine that exhalation is detected. The determination threshold can be set in advance. The operation unit 20 can calculate at least one of the cycle and length of breathing. The operation unit 20 can calculate the cycle or length of breathing during the period when the value of the determination signal is lower than the determination threshold. The operation unit 20 can set a continuous period in which the value of the determination signal is lower than the determination threshold as the length of breathing. The operation unit 20 can calculate the sum of a continuous period in which the value of the determination signal is higher than the determination threshold and a continuous period in which the value of the determination signal is lower than the determination threshold as the cycle of breathing. The operation unit 20 can calculate the average value within a specified measurement period as the cycle or length of breathing. By calculating the cycle or length of breathing, it is possible to determine whether the emotion of the person who is breathing is excited or relaxed, etc. In the case of measuring the cycle or length of breathing, as long as the value of the determination signal can be compared with the determination threshold, the amplitude of the determination signal does not need to be calculated, and the measurement accuracy of the value of the determination signal may not be high.

[0091] Here, setting the coefficient b0 in the infinite impulse response is equivalent to removing frequency components above a predetermined frequency from the signal value in the calculation of the baseline. When the predetermined frequency is set as the first cutoff frequency, the relationship between the first cutoff frequency and the coefficient b0 is expressed by the following equation 5. In the equation, a1=b0-1.

[0092] [Number 5]

[0093]

[0094] The calculation unit 20 can calculate the baseline based on the frequency component of the time waveform of the light receiving signal ratio that is lower than the set first cutoff frequency. By setting the coefficient b0 in the infinite impulse response, the baseline can be calculated based on the frequency component of the light receiving signal ratio that is lower than the first cutoff frequency. A specific example of the coefficient b0 and the first cutoff frequency will be described later.

[0095] Figure 4A This is a diagram showing an example of a result obtained by using a fixed first cutoff frequency in the baseline calculation. Figure 4A The axis and the solid and dashed lines in the figure Figure 3 In this example, the baseline calculation is performed so that the first cutoff frequency is fixed for the value yn of the baseline at each time. For example, in the example of Table 1, b0 is a fixed value for all n. Figure 4A The baseline has poor tracking performance when the light receiving signal ratio increases. Therefore, during the period of continuous breathing, the baseline does not return to the original level (IR1 / IR2=1 to 1.01), but becomes a relatively low level. In addition, there is a part where the baseline is lower than the light receiving signal ratio just after the period of continuous breathing ends.

[0096] Figure 4B It shows that according to Figure 4A An example of a judgment signal obtained by taking the difference between the received light signal ratio and the baseline calculated value. The judgment signal represents a signal component based on exhalation, so the judgment signal in the absence of exhalation is ideally consistent with the reference point (IR1 / IR2=0). In addition, the judgment signal in the presence of exhalation is ideally smaller than the reference point. Figure 4B In the above example, a portion of the judgment signal is located above (positive side) the reference point (IR1 / IR2=0). The judgment signal is shifted upward. This is considered to be because the baseline is evaluated to be smaller than it actually is due to poor tracking of the baseline when the light receiving signal ratio increases.

[0097] The dashed line in the figure indicates the determination threshold. As an example, when the signal value is lower than the determination threshold, it is determined that exhalation is detected. Figure 4B In the present invention, since only a part of the change in the signal value caused by exhalation falls below the determination threshold, a part of the breathing may not be detected. Therefore, it is preferable to calculate the breathing cycle more accurately.

[0098] Figure 5AThis is a diagram showing an example of the result obtained by changing the first cut-off frequency according to the magnitude relationship with the immediately preceding signal value in baseline calculation. The first cut-off frequency can be set according to the change in the signal value of the received light signal ratio. In this example, the operation unit 20 changes the first cut-off frequency according to the change in the signal value of the received light signal ratio. The operation unit 20 in this example sets the first cut-off frequency to be higher when the signal value of the object for calculating the baseline in the received light signal ratio increases with respect to the signal value at the immediately preceding moment in the time waveform of the received light signal ratio than when the signal value of the object for calculating the baseline decreases with respect to the immediately preceding signal value.

[0099] When using the notations in Table 1, the first cut-off frequency when xn > xn-1 is set to be higher than the first cut-off frequency when xn < xn-1. The operation unit 20 can set the first cut-off frequency to be higher by making the coefficient b0 when xn > xn-1 larger than the coefficient b0 when xn < xn-1. By increasing the first cut-off frequency, even the relatively high frequency components in the signal waveform of the first light emission signal can be reflected in the baseline. Therefore, the followability of the baseline when the signal value of the first light emission signal increases is improved. In Figure 5A it, the baseline follows well the increase in the signal value of the first light emission signal. Therefore, during the period of continuous breathing and the period immediately following it, compared with the example of Figure 4A the baseline returns to the vicinity of the original value (1 to 1.01).

[0100] When exhaled air flows into the exhalation sensor 10, after detecting carbon dioxide, the temperature of the element rises due to the temperature of the exhaled air. Therefore, it is considered that the influence of the temperature characteristics of the element appears in the time waveform of the baseline. The temperature of the element changes synchronously with breathing, so valleys synchronous with breathing as shown in Figure 5A appear in the time waveform of the baseline. It is considered that the influence of the temperature of the exhaled air appears later than the detection of carbon dioxide. By the above setting of the first cut-off frequency, during the period when the signal value of the received light signal ratio decreases, the baseline calculation value is difficult to follow the change in the signal value caused by the detection of carbon dioxide, so the baseline calculation value is not likely to include the influence caused by carbon dioxide, and the influence of the temperature of the exhaled air is appropriately reflected.

[0101] The operation unit 20 may set the first cutoff frequency higher when the signal value of the object of the calculation baseline value of the light receiving signal ratio increases relative to the past signal value in the time waveform of the light receiving signal ratio than the first cutoff frequency when the signal value of the object of the calculation baseline value decreases relative to the past signal value. The above-mentioned past signal value may be the average value of the light receiving signal ratio in a period shorter than the breathing cycle of the period in which the light receiving signal ratio immediately before is set as the end of the period, or may be the signal value of any light receiving signal ratio in the period, or may be the signal value of all light receiving signal ratios in the period. When the notation of Table 1 is used, as an example, the first cutoff frequency in the case where xn is higher than the average value of xn-1, xn-2, and xn-3 may be set higher than the first cutoff frequency in the case where xn is lower than the average value. The operation unit 20 may also set the first cutoff frequency higher when the signal value of the object of the calculation baseline value of the light receiving signal ratio increases by more than 20% relative to the past signal value in the time waveform of the light receiving signal ratio than the first cutoff frequency in the case where the signal value of the object of the calculation baseline value decreases by more than 20% relative to the past signal value.

[0102] Figure 5B It shows that according to Figure 5A An example of a judgment signal calculated by the light receiving signal ratio and the baseline is shown in FIG. Figure 5B In the figure, the tiny noise component is removed, and the judgment signal is located below the reference point (IR1 / IR2=0) at all times. Figure 4B The determination threshold is similarly shown. According to this example, the deviation of the determination signal can be suppressed, and the breathing can be detected more accurately and the cycle and length of the breathing can be calculated.

[0103] The operation unit 20 can set the first cut-off frequency when the signal value of the object serving as the calculation baseline of the received light signal ratio increases with respect to the signal value at the immediately preceding moment in the time waveform of the received light signal ratio to be more than 10 times higher than the first cut-off frequency when the signal value of the object serving as the calculation baseline decreases with respect to the immediately preceding signal value. As an example, the first cut-off frequency when xn > xn-1 can be set to 1 Hz or more (for example, about 1.8 Hz (coefficient b0 = 0.24)), and the first cut-off frequency when xn < xn-1 can be set to 0.1 Hz or less (for example, about 0.06 Hz (coefficient b0 = 0.01)). Thereby, the followability of the baseline is further improved. The above magnification can also be 2 times or more, can also be 5 times or more, and can also be 20 times or more. The first cut-off frequency can also be 3 Hz or less. In addition, the signal value at the immediately preceding moment can be the above-mentioned past signal value. The operation unit 20 can set the first cut-off frequency when the signal value of the object serving as the calculation baseline of the received light signal ratio increases by 20% or more with respect to the signal value at the immediately preceding moment in the time waveform of the received light signal ratio to be more than 10 times higher than the first cut-off frequency when the signal value of the object serving as the calculation baseline decreases by 20% or more with respect to the immediately preceding signal value.

[0104] Fig. 6A FIG. is an example showing a case where signal processing is performed on the first received light signal and the second received light signal using equal cut-off frequencies. Fig. 6A The horizontal axis represents time, the left vertical axis represents the signal intensity (%) of the first received light signal (IR1), and the right vertical axis represents the signal intensity (%) of the second received light signal (IR2). The first received light signal is represented by a solid line, and the second received light signal is represented by a dotted line. The reference of the signal intensity can be the signal value when there is no exhalation. The signal intensity in this example is the value obtained by expressing the value of each signal as a percentage when normalizing the value of each signal with the value of each signal when there is no exhalation as 100% (reference value). The difference between the reference value and the signal intensity is defined as the change rate. In the case of this example, the change rate (%) = reference value (100%) - signal intensity (%). The greater the deviation of the signal intensity from 100%, the greater the change rate, indicating a greater change with respect to the reference value. However, the reference value can also be a value other than 100%.

[0105] For Fig. 6A the first received light signal and the second received light signal, signal processing is performed to remove frequency components of a frequency higher than a specified frequency from the signal value. The specified frequency of the second received light signal is set as the second cut-off frequency, and the specified frequency of the first received light signal is set as the third cut-off frequency. In this example, the second cut-off frequency and the third cut-off frequency are equal.

[0106] The general breathing frequency is about 0.25Hz in normal conditions and about 0.42Hz when breathing is heavy. The value of the third cutoff frequency is set to be higher than 0.42Hz, so that the change of the first light receiving signal caused by breathing can be seen. On the other hand, the second light receiving signal also changes with a period close to that of the first light receiving signal. The second light receiving unit 22 that outputs the second light receiving signal receives the light 14 that does not pass through the path 12 through which the exhalation passes, so it is believed that this is due to the influence caused by the temperature of the exhalation. In particular, when the ambient temperature is low and the temperature difference between the ambient temperature and the exhalation is large, this tendency becomes stronger.

[0107] Figure 6B It shows that according to Fig. 6A FIG. 1 is a diagram showing an example of a light receiving signal ratio calculated between a first light receiving signal and a second light receiving signal. Figure 6B The horizontal axis is time, and the vertical axis is the light receiving signal ratio (%). Fig. 6A The first light receiving signal does not have a periodic waveform. In other words, the change of the first light receiving signal is offset by the change of the second light receiving signal. As a result, the accuracy of breathing detection deteriorates.

[0108] Fig. 7A This is a diagram showing an example in which signal processing is performed on the first light reception signal and the second light reception signal using different cutoff frequencies, respectively. Fig. 7A and Fig. 6A The difference is that the second cutoff frequency is different from the third cutoff frequency. Fig. 6A same. Figure 7B It is shown Fig. 7A A diagram showing an example of the light receiving signal ratio. Figure 7B Except for use Fig. 7A The signal value other than this point is Figure 6B same.

[0109] The calculation unit 20 generates a corrected first light reception signal using the frequency component of the second light reception signal lower than the set second cutoff frequency and the frequency component of the first light reception signal lower than the set third cutoff frequency. In this example, the corrected first light reception signal is a light reception signal ratio.

[0110] In this example, the second cutoff frequency is lower than the third cutoff frequency. Therefore, the period of the second light receiving signal close to the period of the first light receiving signal is removed. As a result, Figure 7B The light receiving signal ratio reflecting the breathing cycle is obtained. The second cutoff frequency can be lower than the normal breathing frequency, that is, 0.25 Hz. The third cutoff frequency can be higher than the frequency of frequent breathing, that is, 0.42 Hz. The calculation unit 20 can perform the above-mentioned baseline calculation based on the above-mentioned light receiving signal ratio.

[0111] The operation unit 20 can change the filter order in the above formula 4 as an alternative to the cutoff frequency to generate the corrected first light receiving signal. When performing noise removal, the operation unit 20 can also change the type of low-pass filter. The operation unit 20 can also change the attenuation slope of the low-pass filter. The attenuation slope is an indicator of the steepness of the signal attenuation in the transition portion from the passband to the stopband of the filter.

[0112] Figure 8 1 is a diagram showing another example of a breath sensor 10 according to an embodiment of the present invention. The light emitting unit 16, the first light receiving unit 18, and the computing unit 20 of the breath sensor 10 of this example are mounted on the same supporting member 30. The breath sensor 10 of this example has a reflecting mirror 32. Between the supporting member 30 and the reflecting mirror 32 is a path 12 through which the breath passes. In the breath sensor 10 of this example, a portion of the light 14 irradiated by the light emitting unit 16 is reflected by the reflecting mirror 32, and the first light receiving unit 18 receives the reflected light 14. The other portions may be connected to the same Figure 1 The same as the breath sensor 10. By setting such a structure, the breath sensor 10 can be miniaturized.

[0113] Fig.9A is a diagram showing a structural example of the light emitting unit 16. The light emitting unit 16 of this example includes a substrate 40, a light emitting element 44, and a second light receiving unit 22. The substrate 40 may be transparent to the light 14. In the case of detecting exhaled breath, the substrate 40 is a GaAs substrate as an example.

[0114] The substrate 40 has a first main surface 41 and a second main surface 42. The first main surface 41 and the second main surface 42 are two main surfaces constituting the substrate 40. In this example, of the two main surfaces, the first main surface 41 is the main surface on the positive side in the Z-axis direction, and the second main surface 42 is the main surface on the negative side in the Z-axis direction. The first main surface 41 faces the path 12 through which the exhaled air passes.

[0115] The light emitting element 44 and the second light receiving unit 22 can be arranged on the same substrate. The light emitting element 44 and the second light receiving unit 22 of this example are arranged on the second main surface 42 of the substrate 40. The light emitting element 44 has a stacked structure portion of a PN junction or a PIN junction. By supplying power to the stacked structure portion, the light emitting element 44 acts as an LED and emits light 14 of a wavelength corresponding to the band gap of the material of the stacked structure portion. In the case of detecting exhalation, the light emitting element 44 can use InAlSb near the absorption wavelength that can output carbon dioxide as the stacked structure portion. The above-mentioned light emitting element 44 is called a quantum infrared light emitting element.

[0116] A part of the light 14 travels through the substrate 40 and is emitted toward the path 12 through the first principal surface 41 . On the other hand, another part of the light 14 travels through the substrate 40 and is reflected by the first principal surface 41 to enter the second light receiving unit 22 .

[0117] The second light receiving unit 22 receives the light 14 that travels through the substrate 40. The second light receiving unit 22 receives the light 14 that does not pass through the path 12 through which the breath passes. This can correct the output fluctuation due to the change in the light amount of the light emitting element 44 or the temperature.

[0118] The second light receiving unit 22 may also have a stacked structure. The stacked structure of the second light receiving unit 22 may be a diode structure of a PN junction or a PIN junction. The stacked structure and material of the second light receiving unit 22 may be the same as the stacked structure and material of the light emitting element 44. Thus, the temperature characteristics of the second light receiving unit 22 can be consistent with the temperature characteristics of the light emitting element 44. The above-mentioned second light receiving unit 22 is called a quantum infrared light receiving element.

[0119] Fig. 9B FIG. 1 is a diagram showing an example of a gas sensor 11 according to an embodiment of the present invention. Figures 1 to 9A In the embodiment of the breath sensor 10, the above embodiment is described, but the above embodiment is not limited to the sensor for detecting breath. The above embodiment can also be widely applied to the gas sensor 11 for detecting the detection target gas.

[0120] The gas sensor 11 may also have Figure 8 or Fig.9A The structure shown. Figures 2 to 9A The breath sensor 10 described in the above may function as a gas sensor 11. For example, the gas sensor 11 may include a light emitting unit 16, a first light receiving unit 18, and a computing unit 20. The computing unit 20 of the gas sensor 11 may perform Figure 2 The signal processing described in the Figures 3 to 5B The baseline calculation and removal described in can also be performed FIG. 6A to FIG. 7B The signal processing described in the above may also be performed in combination.

[0121] The operation unit 20 of the gas sensor 11 can calculate the baseline of the waveform of the first light receiving signal according to the light receiving signal ratio based on the frequency component of the light receiving signal ratio lower than the set first cutoff frequency, and remove the baseline from the light receiving signal ratio. The operation unit 20 of the gas sensor 11 can change the first cutoff frequency according to the change of the signal value of the light receiving signal ratio during the calculation of the baseline.

[0122] By applying the above embodiment, the influence of interference other than the detection object can be eliminated, especially when the output value of the gas sensor 11 is prone to change over time and the direction of the output change when detecting the detection object is determined. As an example, it is effective for a methane gas sensor installed outdoors in a place where the ambient temperature is prone to change.

[0123] Fig.10 FIG. 1 is a flow chart showing an example of a breath detection method according to an embodiment of the present invention. Figure 1 The breath sensor 10 of an embodiment of the present invention is used as an example to describe the breath detection method involved in one embodiment of the present invention. The breath detection method includes a light emitting step S100, a first light receiving step S104, a first output step S108, and a calculation step S112. The calculation step S112 includes a calculation step S114 and a detection step S116.

[0124] The light emitting step S100 is a step in which the light emitting unit 16 emits the light 14 toward the path 12 through which the exhaled breath passes. The first light receiving step S104 is a step in which the first light receiving unit 18 receives at least a portion of the light 14 irradiated in the light emitting step S100. The first output step S108 is a step in which the first light receiving unit 18 outputs a first light receiving signal corresponding to the light receiving result in the first light receiving step S104. The calculation step S112 is a step in which the calculation unit 20 calculates the first light receiving signal output in the first output step S108.

[0125] The calculation step S114 is a step in which the operation unit 20 calculates the baseline of the waveform of the first light receiving signal based on the frequency component of the first light receiving signal that is lower than the set first cutoff frequency. The detection step S116 is a step in which the operation unit 20 detects exhalation based on the signal obtained by removing the baseline calculated in the calculation step S114 from the first light receiving signal.

[0126] The calculation step S112 may be a step in which the calculation unit 20 calculates at least one of the cycle and the length of the respiration. The first cutoff frequency may be set according to a change in the signal value of the first light receiving signal.

[0127] The operation step S112 may be a step in which the operation unit 20 sets the first cutoff frequency when the signal value of the object of the calculation baseline value of the first light-receiving signal increases in the time waveform of the first light-receiving signal relative to the past signal value to a higher cutoff frequency than the first cutoff frequency when the signal value of the object of the calculation baseline value decreases relative to the past signal value. The operation step S112 may also be a step in which the operation unit 20 sets the first cutoff frequency when the signal value of the object of the calculation baseline value of the first light-receiving signal increases by more than 20% relative to the past signal value in the time waveform of the first light-receiving signal to a higher cutoff frequency than the first cutoff frequency when the signal value of the object of the calculation baseline value decreases relative to the past signal value to a higher cutoff frequency.

[0128] The operation step S112 may be a step in which the operation unit 20 sets the first cutoff frequency when the signal value of the object of the value of the calculation baseline of the first light-receiving signal increases relative to the signal value at the immediately previous moment in the time waveform of the first light-receiving signal to be higher than the first cutoff frequency when the signal value of the object of the value of the calculation baseline decreases relative to the signal value at the immediately previous moment. The operation step S112 may be a step in which the operation unit 20 sets the first cutoff frequency when the signal value of the object of the value of the calculation baseline of the first light-receiving signal increases by more than 20% relative to the signal value at the immediately previous moment in the time waveform of the first light-receiving signal to be higher than the first cutoff frequency when the signal value of the object of the value of the calculation baseline decreases by more than 20% relative to the signal value at the immediately previous moment in the time waveform of the first light-receiving signal.

[0129] Fig.11 1 is a flowchart showing another example of the breath detection method according to one embodiment of the present invention. Fig.11 Breath detection method and Fig.10 The difference of the breath detection method is that it also includes a second light receiving step S120, a second output step S124 and a correction step S128. The operation step S112 may include the correction step S128.

[0130] The second light receiving step S120 is a step in which the second light receiving unit 22 receives the light 14 that has not passed through the path 12 through which the exhaled breath passes, among the light 14 irradiated by the light emitting unit 16. The second output step S124 is a step in which the second light receiving unit 22 outputs a second light receiving signal corresponding to the light receiving result in the second light receiving step S120. The correction step S128 is a step in which the operation unit 20 corrects the first light receiving signal based on the signal value of the second light receiving signal. In this example, the calculation step S114 is a step in which the operation unit 20 calculates the baseline of the waveform of the first light receiving signal based on the frequency component of the first light receiving signal that is lower than the set first cutoff frequency after being corrected in the correction step S128.

[0131] Fig.12 1 is a schematic diagram showing an example of a breath detection system 100 according to an embodiment of the present invention. The breath detection system 100 detects the breath of a user 200. The breath detection system 100 may be a part or the whole of a device worn by the user 200. The breath detection system 100 of this example is the whole of an earphone worn on the head of the user 200.

[0132] Fig.12The exhalation detection system 100 shown includes a main body 102 and an exhalation sensor 10. The exhalation sensor 10 is provided in the main body 102 and is used to detect the exhalation of the user 200. Exhalation refers to the breath exhaled by the user 200 through breathing. The exhalation sensor 10 can detect the exhalation of the user 200 based on the concentration of carbon dioxide. The exhalation sensor 10 can measure the concentration of carbon dioxide in the measurement space by measuring the absorption intensity of infrared rays passing through the measurement space.

[0133] The exhalation sensor 10 may determine that the exhalation of the user 200 is detected when the measured carbon dioxide concentration is greater than the reference value. The exhalation sensor 10 may also detect the breathing cycle or breathing length of the user 200 based on the exhalation detection result. The exhalation sensor 10 may calculate the period during which the carbon dioxide concentration is greater than the reference value as the length of one breath. The exhalation sensor 10 may calculate the length obtained by dividing the unit time by the number of breaths in the unit time as the breathing cycle.

[0134] The main body 102 of this example includes a fixed part 110 and a movable part 120. As an example, the fixed part 110 is worn on the head of the user 200. The fixed part 110 may include a sound generating part 112 that generates sound. The sound generating part 112 may include a pad part that contacts the ear of the user 200 when the main body 102 is worn, and a speaker provided in the pad part. The fixed part 110 may include two sound generating parts 112 corresponding to the two ears of the user 200, and an arm part 113 that connects the two sound generating parts 112.

[0135] The movable part 120 is movably provided on the fixed part 110. That is, the relative position of at least a part of the movable part 120 with respect to at least a part of the fixed part 110 can be changed. The movable part 120 of this example has a rod-shaped part extending from the fixed part 110. The rod-shaped part is connected to the connecting part 111 in the fixed part 110. The rod-shaped part can rotate relative to the fixed part 110 with the connecting part 111 as a rotation axis.

[0136] The exhalation sensor 10 can be disposed in the movable part 120. The relative position of the exhalation sensor 10 with respect to the fixed part 110 can be changed as the movable part 120 moves. The exhalation sensor 10 of this example is disposed at the end of the movable part 120 on the side opposite to the connecting part 111. A sound detection part 122 for detecting sound is disposed at the end. The sound detection part 122 is, for example, a microphone. The exhalation sensor 10 can also be disposed in the sound detection part 122. By arranging the sound detection part 122 and the exhalation sensor 10 close to each other, the exhalation sensor 10 can be easily arranged near the mouth of the user 200, thereby easily detecting the exhalation of the user 200.

[0137] The main body 102 may further include a display unit for displaying information. The display unit may be, for example, a head mounted display connected to the fixing unit 110. The display unit may be movably provided on the fixing unit 110. The breath sensor 10 may also be provided on the display unit.

[0138] Fig.13 1 is a functional block diagram showing an example of a breath detection system 100. The breath detection system 100 of this example includes a main body 102, a state detection unit 150, and a control unit 140. Fig.12 The main body 102 of this example has a fixed portion 110 and a movable portion 120. In addition, the breath sensor 10 is provided on the movable portion 120. The calculation unit 20 (see Figure 1 ) can function as the control unit 140. The calculation unit 20 can function as a part of the state detection unit 150.

[0139] exist Fig.13 In the embodiment, the state detection unit 150 and the control unit 140 are arranged outside the main body 102, but the state detection unit 150 and the control unit 140 may also be provided in the main body 102. The control unit 140 may be provided on the same substrate as the breath sensor 10. The control unit 140 may receive a signal from the state detection unit 150. The control unit 140 may receive the signal by a signal transmission method based on a wired method or a wireless method.

[0140] The state detection unit 150 detects the state of at least one of the main body 102 and the breath sensor 10. In this specification, the state of at least one of the main body 102 and the breath sensor 10 is sometimes referred to as the state of the main body 102. The state of the main body 102 may include at least one of a position state indicating the relative position of the movable part 120 and other components with respect to the fixed part 110, an operation state indicating the electrical state of the main body 102, and an environmental state indicating the surrounding environment of the main body 102.

[0141] The position state may be information indicating the state of a component that affects the relative position of the breath sensor 10 with respect to the fixing portion 110. The position state may be information directly indicating the relative position of the breath sensor 10.

[0142] The operation state may be information indicating the presence, magnitude, frequency, etc. of power or control signals input to the main unit 102. The operation state may be information indicating the presence, magnitude, frequency, etc. of electrical signals generated by each component of the main unit 102. The operation state may be information indicating the magnitude of power consumed by the main unit 102.

[0143] More specifically, the operation state may be information indicating whether a control signal for causing the sound generating unit 112 to generate sound is input to the main unit 102, or information indicating whether a control signal for causing the display unit to display information is input to the main unit 102. The sound detecting unit 122 changes the detected sound into an electrical signal. The operation state may also be information indicating the presence, size, frequency, etc. of the electrical signal output by the sound detecting unit 122. In the case where the power supply of the main unit 102 is supplied by a battery of the main unit 102, the operation state may be information indicating the remaining capacity of the battery.

[0144] The environmental state may be information indicating at least one of the temperature, humidity, air pressure, and wind speed around the main body 102. The state detection unit 150 may include a sensor for detecting such information.

[0145] The breath sensor 10 has a plurality of operation modes with different power consumption. The breath sensor 10 of this example has an active state capable of detecting breath and a standby state in which power consumption is less than that in the active state as operation modes. For example, in the active state, the light emitting element of the breath sensor 10 continuously irradiates light such as infrared light. The power consumption per unit time of the light emitting element in the standby state is less than that of the light emitting element in the active state.

[0146] The light emission period of the light emitting element in the standby state may be longer than that of the light emitting element in the activated state. The light emission intensity of the light emitting element in the standby state may be smaller than that of the light emitting element in the activated state. In the standby state, the light emission of the light emitting element may also be stopped.

[0147] The control unit 140 changes the operation mode of the breath sensor 10 based on the state of at least one of the main body 102 and the breath sensor 10 detected by the state detection unit 150. When the state of the main body 102 satisfies a preset condition, the control unit 140 may change the operation mode so as to reduce the power consumption of the breath sensor 10 compared to a case where the condition is not satisfied. The condition is, for example, a condition indicating that the breath sensor 10 is in a state where it should not detect breath.

[0148] For example, when the breath sensor 10 is arranged at a position far from the mouth of the user 200, the breath sensor 10 cannot detect the breath of the user 200 with high accuracy. When the position state of the main body 102 satisfies a preset condition, the control unit 140 can change the operation mode in a manner that reduces the power consumption of the breath sensor 10. In this way, the power consumption of the breath sensor 10 can be reduced.

[0149] When the application software that operates the main body 102 does not request to detect the exhalation of the user 200, the exhalation sensor 10 may not detect the exhalation. The control unit 140 may change the operation mode in a manner that reduces the power consumption of the exhalation sensor 10 when the operation state represented by the control signal for the main body 102 satisfies a preset condition. In this way, the power consumption of the exhalation sensor 10 can be reduced. In addition, when the remaining capacity of the battery of the main body 102 becomes less than a preset reference value, the control unit 140 may change the operation mode in a manner that reduces the power consumption of the exhalation sensor 10. In this way, the consumption of the remaining capacity of the battery can be suppressed.

[0150] When the user 200 is speaking, the breath sensor 10 cannot detect information related to the user 200's breath (such as the breathing cycle) with high accuracy. When the amplitude of the electrical signal output by the sound detection unit 122 satisfies a preset condition, the control unit 140 can change the operation mode in a manner that reduces the power consumption of the breath sensor 10. In this way, the power consumption of the breath sensor 10 can be reduced.

[0151] Depending on the temperature, humidity, air pressure or wind speed around the breath sensor 10, the breath sensor 10 may not be able to detect the breath with high accuracy. For example, the temperature characteristics of the breath sensor 10 may cause errors in the detection results of the breath sensor 10. In addition, when condensation occurs on optical elements such as the light-emitting element and the light-receiving element of the breath sensor 10, errors may occur in the detection results of the breath sensor 10. In addition, when the wind speed is too strong, the breath is easily diffused in the space during the period when it is transmitted from the mouth of the user 200 to the breath sensor 10, resulting in errors in the detection results of the breath sensor 10. The control unit 140 can change the operation mode in a manner that reduces the power consumption of the breath sensor 10 when the environmental state of the main body 102 meets the pre-set conditions. In this way, the power consumption of the breath sensor 10 can be reduced.

[0152] Fig.14 1 is a diagram showing an example of the position state of the main body 102. Fig.12 Compared with the example shown in FIG. 1 , the rotation angle of the movable part 120 relative to the fixed part 110 in this example is changed. Fig.12 Compared with the example shown in the figure, the breath sensor 10 is arranged at a position far from the mouth of the user 200. In such a case, the breath sensor 10 cannot detect the breath of the user 200 with high accuracy.

[0153] The control unit 140 may control the operation mode of the breath sensor 10 according to whether the state of the movable unit 120 satisfies a preset condition. The control unit 140 may switch the breath sensor 10 to the standby state when the rotation angle of the movable unit 120 is outside a preset range.

[0154] Fig.15 1 is a diagram showing another example of the state of the main body 102. In this example, the user 200 is speaking. The exhalation detected by the exhalation sensor 10 when the user 200 is speaking may be different from the exhalation when the user 200 is not speaking. Therefore, when it is intended to detect the length and period of breathing when the user 200 is not speaking, even if the exhalation sensor 10 is operated when the user 200 is speaking, the length and period of breathing cannot be detected with high accuracy.

[0155] The control unit 140 can control the operation mode of the breath sensor 10 according to whether the electrical signal output by the sound detection unit 122 satisfies a preset condition. The control unit 140 can change the breath sensor 10 to the standby state when the amplitude of the electrical signal (corresponding to the amplitude of the user's 200 voice) becomes greater than a reference value.

[0156] Fig.16 1 is a diagram showing a configuration example of the state detector 150. In addition, the main body 102 of this example has a battery 117 for supplying power to the main body 102. The state detector 150 of this example has at least one or all of a position state detector 151, an environment state detector 152, and an operation state detector 153.

[0157] The position state detector 151 detects the above-mentioned position state. The position state detector 151 may include a sensor that detects the position state such as the rotation angle of the movable part 120 .

[0158] The environmental state detection unit 152 detects the above-mentioned environmental state. The environmental state detection unit 152 may include at least one of a temperature sensor, a humidity sensor, a pressure sensor, and a wind speed sensor.

[0159] The operation state detection unit 153 detects the above-mentioned operation state. Fig.12 The sound detection unit 122 and the sound generation unit 112 shown in the above-mentioned figure may be included in the operation state detection unit 153. The operation state detection unit 153 of this example includes at least one or all of the sound detection unit 122, the sound generation unit 112, the wearing detection unit 154, the signal detection unit 155, the remaining capacity detection unit 156 and the power consumption detection unit 157.

[0160] The sound detector 122 detects the sound. The control unit 140 may control the operation mode of the breath sensor 10 based on the state of the sound detected by the sound detector 122. The control unit 140 may switch the breath sensor 10 to the standby state when the magnitude of the sound detected by the sound detector 122 is greater than a set reference value. The control unit 140 may switch the breath sensor 10 to the active state when the magnitude of the sound detected by the sound detector 122 is less than a set reference value.

[0161] The control unit 140 may also switch the breath sensor 10 to a standby state when the sound detected by the sound detection unit 122 is the voice of the user 200. The control unit 140 may switch the breath sensor 10 to an active state when the voice of the user 200 is no longer detected. The control unit 140 may determine whether the voice of the user 200 is detected based on the magnitude of a preset frequency component in the electrical signal output by the sound detection unit 122. The frequency component is, for example, a component of 80 Hz or more and 1 kHz or less.

[0162] The sound generator 112 generates a sound. The control unit 140 can control the operation mode of the exhalation sensor 10 based on the state of the sound generated or to be generated by the sound generator 112. For example, when it is desired to detect the exhalation of the user 200 who is listening to music or other sounds, the exhalation sensor 10 can be switched from the standby state to the active state when the sound generator 112 generates or is about to generate a sound such as music. In another example, when it is desired to detect the exhalation of the user 200 who is in a resting state, the exhalation sensor 10 can be switched from the standby state to the active state when the magnitude of the sound generated or to be generated by the sound generator 112 is less than a reference value.

[0163] The wearing detector 154 determines whether the main body 102 is worn by the user 200. The wearing detector 154 may be a distance detector that detects the distance between the main body 102 and other objects (e.g., the user 200). The wearing detector 154 may determine that the main body 102 is worn when the distance is less than a reference value, and may determine that the main body 102 is not worn when the distance is greater than the reference value. The control unit 140 may switch the breath sensor 10 to a standby state when the main body 102 is not worn. The control unit 140 may switch the breath sensor 10 to an active state when the main body 102 is worn.

[0164] The signal detection unit 155 detects the state of an input signal input to the main body 102 or an output signal generated by the main body 102. The input signal may be a signal for specifying the state of the breath sensor 10. The control unit 140 may switch the breath sensor 10 to an active state or a standby state based on the input signal. The input signal may also be a signal for controlling the sound generator 112 or the display unit.

[0165] The state of the main body 102 can be changed according to a control signal from application software running on a computer inside or outside the main body 102. The control signal can control the sound generator 112 or the display unit. The signal detector 155 can control the operation mode of the breath sensor 10 based on the control signal.

[0166] The control unit 140 may change the breath sensor 10 to an active state or a standby state when a control signal for changing the sound generator 112 or the display unit to a specified state is input. The specified state may be preset in the control unit 140. The control unit 140 may change the breath sensor 10 to an active state when the maximum volume generated by the sound generator 112 or the maximum brightness of the image displayed on the display unit is greater than a specified reference value. In other examples, the control unit 140 may also change the breath sensor 10 to a standby state when the maximum volume generated by the sound generator 112 or the maximum brightness of the image displayed on the display unit is greater than a specified reference value. The state to which the breath sensor 10 is to be changed based on the comparison result of the state value and the reference value may be specified by the application software.

[0167] The control unit 140 may control the operation mode of the breath sensor 10 based on the type of the above-mentioned application software. The control signal may include information indicating the type of the application software. For example, when the application software is a game application, the control unit 140 controls the breath sensor 10 to be in an active state. When the application software is a conference application for conducting a conference between users on the web, the control unit 140 may control the breath sensor 10 to be in a standby state.

[0168] The remaining capacity detection unit 156 can detect the remaining capacity of the power that the battery 117 can output, can detect the charging state of the battery 117 (for example, charging has started, charging has stopped, or charging is in progress), and can detect both the remaining capacity and the charging state. The control unit 140 can control the breath sensor 10 based on the remaining capacity of the battery 117, and can also control the breath sensor 10 based on the charging state of the battery 117. The control unit 140 can change the breath sensor 10 to a standby state when the remaining capacity is lower than a reference value. The control unit 140 can change the breath sensor 10 to an active state when it detects that the charging of the battery 117 has started. In addition, the control unit 140 can also change the breath sensor 10 to a standby state to quickly charge the battery 117 when it detects that the charging of the battery 117 has started.

[0169] The power consumption detection unit 157 detects the power consumption of the main body 102. The main body 102 can have a plurality of operation states with different power consumption. For example, the main body 102 has a startup state in which the power is connected to the power source, and a stop state in which the power is not connected to the power source. The control unit 140 can control the operation mode of the breath sensor 10 based on the operation state of the main body 102. The control unit 140 can make the breath sensor 10 active when the main body 102 is in the startup state, and put the breath sensor 10 in the standby state when the main body 102 is in the stop state. The control unit 140 can change the breath sensor 10 to the standby state when the power consumption of the main body 102 is below the set reference value.

[0170] The action state detection unit 153 can detect the action state of the main body 102 based on the exhalation detected by the exhalation sensor 10. That is, the exhalation sensor 10 can also function as the action state detection unit 153. The control unit 140 can control the action mode of the exhalation sensor 10 based on the exhalation detected by the exhalation sensor 10. The control unit 140 can change the exhalation sensor 10 to the standby state when the size of the exhalation is less than the set value for more than the set period. In other examples, when it is desired to detect the exhalation of the user 200 in an excited state, the control unit 140 can change the exhalation sensor 10 to the standby state when the breathing cycle calculated based on the exhalation becomes a set stable range.

[0171] Based on Fig.16 By controlling the breath sensor 10 according to the state of the main body 102 described in the above, it is possible to suppress the power consumption of the breath sensor 10. In particular, when the main body 102 is not supplied with power from an external power source, it is preferable to suppress the power consumption of the breath sensor 10 to avoid shortening the driving time of the main body 102 by the battery 117.

[0172] The control unit 140 can Fig.16 Each state of the main body 102 described in the above is evaluated as a state value. The state value is a numerical value indicating the degree of the state. For example, the position state of the movable part 120 can be evaluated by the relative coordinate value of the evaluation position of the front end of the movable part 120 relative to the reference position of the connecting part 111 of the fixed part 110, or the rotation angle of the movable part 120 relative to the fixed part 110. The state value can be the value of temperature, humidity, pressure, wind speed, the size, frequency, and duration of the sound detected by the sound detection part 122, the size, frequency, and duration of the sound generated by the sound generation part 112, the remaining capacity of the battery 117, the power consumption of the main body 102, or the value of other parameters.

[0173] The control unit 140 can control the operation mode of the breath sensor 10 by comparing the state value of the main body 102 with a set reference value. The reference value can be set for each type of state of the main body 102. The type of state refers to the type of parameter such as the angle of the state of the main body 102 and the size of the sound.

[0174] The reference value when the breath sensor 10 is switched from the active state to the standby state may be the same as or different from the reference value when the breath sensor 10 is switched from the standby state to the active state. By making the reference values ​​different, it is possible to prevent the state transition of the breath sensor 10 from occurring continuously in a short cycle.

[0175] The main body 102 may have a plurality of states, and each state may be changed. For example, the main body 102 may have a plurality of states such as the position of the movable part 120 and the size of the sound detected by the sound detector 122. Each state may be changed such as the position of the movable part 120 and the size of the sound detected by the sound detector 122.

[0176] The control unit 140 may control the operation mode of the breath sensor 10 based on two or more types of states of the main body 102. The control unit 140 may control the breath sensor 10 to the standby state when at least one of the multiple states to be used in controlling the operation mode of the breath sensor 10 indicates that the breath sensor 10 should be set to the standby state. In other words, the control unit 140 may control the breath sensor 10 to the active state when all of the multiple states to be used in controlling the operation mode of the breath sensor 10 indicate that the breath sensor 10 should be set to the active state.

[0177] In other examples, the multiple types of states of the main body 102 may be classified into two or more types. With respect to the one or more states included in the first category, when at least one state indicates that the breath sensor 10 should be set to the standby state, the breath sensor 10 may be controlled to the standby state. With respect to the multiple states included in the second category, when two or more states indicate that the breath sensor 10 should be set to the standby state, the breath sensor 10 may be controlled to the standby state.

[0178] The first category may include a state for determining that breath detection is not necessary or that power consumption due to breath detection is not acceptable. For example, the first category includes the wearing state of the main body 102, the power consumption state of the main body 102, the remaining capacity state of the battery 117, and the type of application software.

[0179] The second category may include a state for determining whether the accuracy of breath detection has decreased, such as the state of the surrounding environment of the breath sensor 10, the state of the position of the movable part 120, the state of the sound of the sound detection part 122, and the state of the sound of the sound generation part 112.

[0180] The control unit 140 may also perform processing using another second type of state during the determination using the first type of state of the main body 102. For example, the control unit 140 may compare the time waveform of the sound detected by the sound detection unit 122 with the time waveform of the exhalation (e.g., carbon dioxide concentration) detected by the exhalation sensor 10 to determine whether the sound detected by the sound detection unit 122 is from the user 200. The exhalation sensor 10 before this determination is in an activated state. The control unit 140 may change the exhalation sensor 10 from the activated state to the standby state when it is determined that the sound from the user 200 is detected.

[0181] The control unit 140 can determine that the sound from the user 200 has been detected when the correlation coefficient between the time waveform of the sound and the time waveform of the exhalation is greater than the reference value. The correlation coefficient is represented by a real number from 1 to -1. When the correlation coefficient is 1, the two time waveforms are consistent, and the lower the similarity of the two time waveforms, the closer the value of the correlation coefficient is to 0. When the user 200 is speaking, carbon dioxide is discharged in accordance with the speaking. Therefore, when the user 200 is speaking, the time waveform of the sound and the time waveform of the exhalation mostly change synchronously. Therefore, the correlation coefficient becomes larger.

[0182] The control unit 140 can determine that the sound from the user 200 has been detected when the magnitude (e.g., peak value) of the sound detected by the sound detection unit 122 is greater than a reference value and the correlation coefficient between the time waveform of the sound and the time waveform of the exhalation is greater than a reference value. By such control, the sound of the user 200 can be detected with higher accuracy.

[0183] The control unit 140 can perform a process of assigning priorities to the categories of the status of the main body 102. The priorities of each category can be set in advance by the user or the manufacturer. Each category includes one or more types of status of the main body 102. Each status of the main body 102 indicates whether the breath sensor 10 should be set to the active state or the standby state.

[0184] As an example, there is a case where the first state of the main body 102 indicates that the breath sensor 10 should be set to the active state, and the second state of the main body 102 indicates that the breath sensor 10 should be set to the standby state. In this way, when the multiple states of the main body 102 indicate that the breath sensor 10 should be controlled to different operation modes, the control unit 140 can determine which category each state of the main body 102 belongs to. The control unit 140 can control the operation mode of the breath sensor 10 based on the state of the main body 102 belonging to the category with the highest priority.

[0185] As an example, an example in which the status of the main body 102 is divided into three categories is described. In this example, the priority of the first category is higher than the priority of the third category. The priority of the second category may be lower than the priority of the first category, or may be the same as the priority of the first category. For example, the first category includes the status of the application software. The status of the application software may be the content of the instructions from the application software. For example, the second category includes a status for determining a situation where power consumption due to breath detection is not allowed, a wearing status of the main body 102, a status of power consumption of the main body 102, a status of the remaining capacity of the battery 117, and the like. For example, the third category includes a status for determining a situation where the accuracy of breath detection decreases.

[0186] As a more specific example, a case where the application software requests to set the breath sensor 10 to an active state to adjust the position of the breath sensor 10 will be described. For example, the position of the breath sensor 10 may be adjusted to detect the breath of the user 200 with high accuracy. In this case, the state of the application software belonging to the first category requests the active state. On the other hand, the states of the main body 102 belonging to the second category and the third category are various. For example, when the position of the breath sensor 10 is in a position where the breath cannot be detected with high accuracy, the state of the main body 102 included in the third category requests to set the breath sensor 10 to a standby state. In such a case, the control unit 140 may prioritize the request from the application software belonging to the first category to set the breath sensor 10 to an active state. In addition, even if the state of the main body 102 belonging to the third category requests to set the breath sensor 10 to a standby state to request to re-evaluate the surrounding environment, the control unit 140 may prioritize the first category and maintain the breath sensor 10 in an active state. For example, when the wind from the fan hits the sound detector 122 and generates a sound, the state of the main body 102 belonging to the third category requests that the breath sensor 10 be set to the standby state. In such a case, by maintaining the breath sensor 10 in the active state according to the request from the application software, the user can be urged not to blow the wind from the fan.

[0187] As another example, the control unit 140 can perform a priority process by combining a plurality of categories. As an example, at least one of the plurality of categories may be an auxiliary category. When the states of the main body 102 belonging to two or more categories indicate that the breath sensor 10 should be controlled to different states, the control unit 140 may control the operation mode of the breath sensor 10 based on the states of the main body 102 belonging to the auxiliary category.

[0188] As a more specific example, the first category includes the status of application software. The second category includes a status for determining that power consumption due to breath detection is not allowed, the wearing status of the main body 102, the power consumption status of the main body 102, and the remaining capacity of the battery 117. The third category includes a charging status indicating whether the battery 117 is being charged. The fourth category includes a status for determining that the accuracy of breath detection has decreased. In this example, the third category is set as an auxiliary category. Here, the first category is set to request an activation state, and the second and fourth categories are set to request standby. When the requests based on other multiple categories are different from each other, the control unit 140 can change the breath sensor 10 to an activation state based on the charging status in the third category, and can also change it to a standby state.

[0189] When changing the exhalation sensor 10 from the active state to the standby state and when changing the exhalation sensor 10 from the standby state to the active state, the control unit 140 can control the state of the exhalation sensor 10 based on different types of states of the main body 102. The control unit 140 can change the exhalation sensor 10 from the standby state to the active state based on the position state of the movable unit 120. For example, in the case where the exhalation sensor 10 is arranged near the mouth of the user 200 according to the position state of the movable unit 120, the control unit 140 changes the exhalation sensor 10 to the active state. The control unit 140 can change the exhalation sensor 10 from the active state to the standby state based on the state of the sound detected by the sound detection unit 122. For example, in the case where the sound detection unit 122 detects the sound of the user 200, the control unit 140 changes the exhalation sensor 10 from the active state to the standby state.

[0190] When there are three or more states of power consumption of the breath sensor 10, the control unit 140 can control the transition of the breath sensor 10 to each operation mode based on the different types of states of the main body 102. As an example, the breath sensor 10 has three operation modes: maximum performance state, energy-saving operation state, and standby state. The maximum performance state is an operation mode in which the power consumption is the largest and the accuracy or frequency of breath detection is the highest among the three operation modes. The energy-saving operation state is an operation mode in which the power consumption is small compared to the maximum performance state and at least one of the accuracy and frequency of breath detection is low. The standby state is an operation mode in which the power consumption is the smallest and the accuracy or frequency of breath detection is the smallest among the three operation modes. The breath sensor 10 in the standby state may not perform breath detection.

[0191] For example, the control unit 140 may change the breath sensor 10 to any operation mode based on a request from the application software. The control unit 140 may change the breath sensor 10 to the energy-saving operation state when the remaining capacity of the battery 117 decreases when the breath sensor 10 is in the maximum performance state. The control unit 140 may change the breath sensor 10 to the standby state when the remaining capacity of the battery 117 further decreases. In addition, the control unit 140 may change the breath sensor 10 from the standby state to the maximum performance state when charging of the battery 117 starts according to the charging state. The control unit 140 may change the breath sensor 10 from the maximum performance state to the standby state when charging of the battery 117 is interrupted and charging is completed, but the remaining battery capacity of the battery 117 is not allowed.

[0192] The control unit 140 may adjust the determination criterion of the state of the main body 102 when the operation mode of the breath sensor 10 is controlled this time, based on the state of the main body 102 used in the determination when the operation mode of the breath sensor 10 was controlled last time. The control unit 140 may change the determination criterion for switching the breath sensor 10 to the standby state immediately after the movable unit 120 is operated and the sound detection unit 122 has just moved to the vicinity of the mouth of the user 200, or in other cases.

[0193] Immediately after the sound detection unit 122 moves to the vicinity of the mouth of the user 200, there is a relatively high possibility that the user 200 will utter a sound. When the breath sensor 10 is switched to the active state according to the position state of the movable unit 120 in the previous control, the control unit 140 can make the reference value used for comparison with the size of the sound detected by the sound detection unit 122 lower than usual. When the size of the sound detected by the sound detection unit 122 is larger than the reference value, the control unit 140 determines that the user 200 is uttering a sound. Thus, it is easy to detect the utterance of the user 200. When the control unit 140 detects the utterance of the user 200, it switches the breath sensor 10 to the standby state. Usually, it refers to the situation in which the breath sensor 10 is switched to the active state according to a state other than the position state of the movable unit 120 in the previous control.

[0194] When the exhalation sensor 10 is switched to the active state according to the position state of the movable part 120 in the previous control, the control part 140 may make the reference value used for comparison with the remaining capacity of the battery 117 higher than usual. When the remaining capacity of the battery 117 is lower than the reference value, the control part 140 switches the exhalation sensor 10 to the standby state. Thus, the exhalation can be detected only when there is a surplus remaining capacity of the battery 117 during a period when the possibility of the user 200 uttering a sound is high.

[0195] Fig.17 1 is a diagram showing an example of a display device 300 according to an embodiment of the present invention. The display device 300 includes an HMD (head mounted device) type display unit 210 and a CO2 (carbon dioxide) sensor 220. The display device 300 including the HMD type display unit 210 is, for example, VR (Virtual Reality) goggles, smart glasses, and the like.

[0196] The display device 300 may include a plurality of CO 2 (carbon dioxide) sensors 220 . In this example, the display device 300 includes two CO 2 (carbon dioxide) sensors 220 (CO 2 (carbon dioxide) sensor 220 - 1 and CO 2 (carbon dioxide) sensor 220 - 2 ). The display device 300 may include an exhaled air volume sensor 224 .

[0197] The CO2 (carbon dioxide) sensor 220 and the exhaled air volume sensor 224 can be provided in the housing 212 of the HMD (head mounted) type display unit 210. The display device 300 of this example has a plurality of openings 222 (opening 222-1 and opening 222-2) on the bottom surface 214 of the housing 212. In this example, the CO2 (carbon dioxide) sensor 220-1 is provided inside the housing 212, and the CO2 (carbon dioxide) sensor 220-2 is provided on the bottom surface 214. In this example, the CO2 (carbon dioxide) sensor 220-2 is exposed to the outside of the housing 212. The exhaled air volume sensor 224 can be provided on the surface of the housing 212. In this example, the exhaled air volume sensor 224 is provided on the bottom surface 214. In the case where the display device 300 is provided with a sound acquisition unit that acquires the voice of the operator 310, the exhaled air volume sensor 224 can be arranged in the sound acquisition unit, or can be arranged close to the sound acquisition unit.

[0198] The CO2 (carbon dioxide) sensor 220 acquires the CO2 (carbon dioxide) concentration in the exhaled air of the operator 310 (described later). In this example, the CO2 (carbon dioxide) sensor 220-1 acquires the CO2 (carbon dioxide) concentration entering the inside of the housing 212 through the opening 222, and the CO2 (carbon dioxide) sensor 220-1 acquires the CO2 (carbon dioxide) concentration outside the housing 212. The data of the change of the CO2 (carbon dioxide) concentration over time acquired by the CO2 (carbon dioxide) sensor 220 can be stored in the storage unit 270 (described later). In addition, the CO2 (carbon dioxide) sensor 220 can also calculate the exhaled volume Vb based on the acquired data.

[0199] The exhaled volume sensor 224 acquires the exhaled volume Vb (described later) of the operator 310 (described later). In this example, the exhaled volume sensor 224 acquires the exhaled volume Vb that enters the interior of the housing 212 through the opening 222. The data of the exhaled volume Vb (described later) acquired by the exhaled volume sensor 224 changing over time can be stored in the storage unit 270 (described later).

[0200] The CO2 (carbon dioxide) sensor 220 and the exhaled volume sensor 224 can also obtain the exhaled cycle of the operator 310 (described later). The CO2 (carbon dioxide) sensor 220 and the exhaled volume sensor 224 can obtain the exhaled volume Vb (described later) of each exhalation based on the exhaled cycle. For example, in the case where the CO2 (carbon dioxide) sensor 220 detects a fixed level of carbon dioxide concentration, the longer the breathing cycle, the easier it is for the exhaled volume Vb to increase, and the shorter the exhaled cycle, the easier it is for the exhaled volume Vb to decrease.

[0201] Fig.18 2 is a diagram showing an example of an operator 310 of the display unit 210. Fig.18 In, omitted Fig.17 The CO2 (carbon dioxide) sensor 220 and the exhaled air volume sensor 224 are shown. In this example, the operator 310 wears the display device 300. The operator 310 is a biological body. In this example, the operator 310 is a person. The operator 310 is visually confirming the characters, images, etc. displayed on the display unit 210. The operator 310 can visually confirm the image of the virtual reality space, etc. displayed on the display unit 210.

[0202] Fig.19 1 is a block diagram showing an example of a display device 300 according to an embodiment of the present invention. The display device 300 may include a determination unit 230 , an operation information acquisition unit 240 , a recognition unit 250 , a biological information acquisition unit 260 , a storage unit 270 , a transmission unit 280 , and a control unit 290 .

[0203] The display device 300 or the breath detection system 100 (see Fig.13 ) may be implemented in part or in whole by a computer. The control unit 290 may be a CPU (Central Processing Unit) of the computer. When the display device 300 is implemented by a computer, a display program for making the computer function as the display device 300 may be installed in the computer, and a display program for executing a display method described later may also be installed.

[0204] The determination unit 230 determines the state of the operator 310 based on the CO2 (carbon dioxide) concentration obtained by the CO2 (carbon dioxide) sensor 220. The state of the operator 310 is set to state S. The state S of the operator 310 may refer to the state of the operator 310's action or the state of emotion. The state of the operator 310's action, for example, refers to whether the operator 310 is in a resting state or in a moving state. When the operator 310 is in a moving state, the state of the operator 310's action, for example, refers to whether the operator 310 is in an anaerobic state or in an aerobic state. The emotional state of the operator 310, for example, refers to whether the operator 310 is in an uneasy state or in a reassuring state. Whether the operator 310 is in a resting state or in a moving state may be determined by whether the CO2 (carbon dioxide) concentration in the exhaled air is above a predetermined threshold value Cth (described later), or by whether the exhaled volume Vb (described later) is above a predetermined threshold value Vth (described later).

[0205] The display unit 210 can display the state S of the operator 310 determined by the determination unit 230. The CO2 (carbon dioxide) concentration in the breath of the operator 310 tends to depend on the state S of the operator 310. Therefore, by displaying the state S on the display unit 210, the operator 310 can recognize his own state S.

[0206] The control unit 290 may control the display unit 210 based on the state S of the operator 310 determined by the determination unit 230. The control unit 290 controlling the display unit 210 based on the state S may include the control unit 290 controlling the display unit 210 to display character information related to the state S, and may also include controlling the brightness, color tone, etc. of the display unit 210 based on the state S. The character information related to the state S is, for example, character information such as "in the state of aerobic exercise" indicating that the operator 310 is in the state of aerobic exercise.

[0207] The control unit 290 can control the display unit 210 based on the CO2 (carbon dioxide) concentration acquired by the CO2 (carbon dioxide) sensor 220 and the reference value of the CO2 (carbon dioxide) concentration. The reference value of the CO2 (carbon dioxide) concentration is set as the reference value Vs. The reference value Vs is the CO2 (carbon dioxide) concentration corresponding to the state S of the operator 310. As described above, the CO2 (carbon dioxide) concentration in the exhaled breath of the operator 310 is likely to depend on the state S of the operator 310.

[0208] The reference value Vs may be a CO 2 (carbon dioxide) concentration in the exhaled breath of the operator 310 that is specified for each of the plurality of states S. The reference value Vs in one state S of the operator 310 may be different from the reference value Vs in another state S of the operator 310. The reference value Vs for each state S may be stored in the storage unit 270.

[0209] The reference value Vs may be specified for each of the plurality of operators 310. The reference value Vs in one state S (e.g., restless state) of one operator 310 may be different from the reference value Vs in the same state S (e.g., restless state) of another operator 310. The reference value Vs for each operator 310 may be stored in the storage unit 270.

[0210] The control unit 290 may control the display unit 210 so that the CO2 (carbon dioxide) concentration acquired by the CO2 (carbon dioxide) sensor 220 is close to the reference value Vs. For example, when it is determined that the state S of the operator 310 is an anaerobic exercise state, the control unit 290 controls the display unit 210 so that a phrase such as "slow down the pace a little more" is displayed on the display unit 210 so that the CO2 (carbon dioxide) concentration in the exhaled breath of the operator 310 is close to the reference value Vs in the case of aerobic exercise. For example, when it is determined that the operator 310 is in an uneasy state, the control unit 290 controls the display unit 210 so that the image displayed on the display unit 210 is changed to a bright color so that the CO2 (carbon dioxide) concentration in the exhaled breath of the operator 310 is close to the reference value Vs in the case of a reassuring state.

[0211] The CO2 (carbon dioxide) sensor 220 can also acquire the CO2 (carbon dioxide) concentration in the exhaled breath of the operator 310 after the control unit 290 controls the display unit 210 based on the CO2 (carbon dioxide) concentration and the reference value Vs. The determination unit 230 can determine the state S of the operator 310 based on the CO2 (carbon dioxide) concentration after controlling the display unit 210. The display unit 210 can display the state S. Thus, the operator 310 can confirm whether his own state S has become the desired state S.

[0212] The control unit 290 can control the display unit 210 based on the change from the CO2 (carbon dioxide) concentration before the display unit 210 is controlled to the CO2 (carbon dioxide) concentration after the display unit 210 is controlled. The determination unit 230 can determine the state S of the operator 310 after the display unit 210 is controlled. The control unit 290 can control the display unit 210 based on the state S of the operator 310. Thus, the operator 310 can confirm whether the display unit 210 is controlled so that the state S of the operator 310 becomes the desired state S.

[0213] Fig. 20 4 is a diagram showing an example of a situation in which an operator 310 is using a device 400. The device 400 is a device that may affect the increase or decrease of the CO2 (carbon dioxide) concentration in the breath of the operator 310. The device 400 is, for example, a device for exercise (sports equipment), a controller in an experience-type game device that is used to operate the game device and is operated by the operator 310, etc. In this example, the device 400 is a treadmill.

[0214] The operator 310 can use the device 400 while wearing the display device 300. Fig. 20 , the CO2 (carbon dioxide) sensor 220 provided by the display device 300 is omitted. The CO2 (carbon dioxide) concentration in the breath of the operator 310 can change according to the use status of the device 400 by the operator 310. In the case where the device 400 is a sports device, an experience-type game device, etc., the state of the operator 310 is likely to change according to the use status of the device 400. For example, in the case where the device 400 is a treadmill, the CO2 (carbon dioxide) concentration in the breath of the operator 310, or the exhaled volume Vb (described later) or the exhaled cycle is likely to change according to the use time of the treadmill by the operator 310. For example, in the case where the device 400 is an experience-type game device, the operator 310 sometimes falls into an excited state while playing a game. When the operator 310 falls into an excited state, the operator 310 sometimes moves his own body. Therefore, depending on the usage of the experience-based game device by the operator 310, the CO 2 (carbon dioxide) concentration in the exhaled breath of the operator 310, or the exhaled volume Vb (described later) or the exhaled cycle may change.

[0215] The device 400 may include a display unit 410, a transceiver unit 420, a control unit 430, an operation unit 440, and an identification unit 450. The control unit 430 may be a CPU. The display unit 410 is, for example, a display, a monitor, etc. The operation unit 440 is, for example, a button, a keyboard, etc. The identification unit 450 is, for example, a camera or other imaging device. The operator 310 performs operations such as setting the device 400 through the operation unit 440.

[0216] The control unit 290 can control the device 400 based on the state S of the operator 310 determined by the determination unit 230. The control unit 290 can generate a control signal Sc (see Fig.19 ). Transmitting unit 280 (refer to Fig.19 ) can send the generated control signal Sc to the transceiver 420 of the device 400. The sending unit 280 can send the control signal Sc to the transceiver 420 in a wireless manner. The transceiver 420 can receive the control signal Sc. The control unit 430 can control the display unit 410 based on the control signal Sc, and can also control the device 400.

[0217] The control unit 290 controlling the device 400 based on the state S may include the control unit 290 controlling the display unit 410 to display character information related to the state S, and may also include controlling the brightness, color tone, etc. of the display unit 410 based on the state S. The character information related to the state S is, for example, character information such as "in the state of aerobic exercise" indicating that the operator 310 is in the state of aerobic exercise.

[0218] The control unit 290 can control the device 400 based on the CO2 (carbon dioxide) concentration in the breath of the operator 310 and the reference value Vs of the CO2 (carbon dioxide) concentration. The control unit 290 can control the device 400 so that the CO2 (carbon dioxide) concentration acquired by the CO2 (carbon dioxide) sensor 220 is close to the reference value Vs. For example, when it is determined that the state S of the operator 310 is an anaerobic exercise state, the control unit 290 controls the display unit 410 so that a phrase such as "slow down the pace a little more" is displayed on the display unit 410 so that the CO2 (carbon dioxide) concentration in the breath of the operator 310 is close to the reference value Vs in the case of aerobic exercise. For example, when the operator 310 plays a game through an experience-type game device, when it is determined that the state S of the operator 310 is an uneasy state, the control unit 290 controls the screen of the game device so that the state S of the operator 310 is close to the reference value Vs of the safe state, or controls the screen of the game device to deliberately approach the reference value Vs of the excessive uneasy state.

[0219] The CO2 (carbon dioxide) sensor 220 can also acquire the CO2 (carbon dioxide) concentration in the exhaled breath of the operator 310 after the control unit 290 controls the device 400 based on the CO2 (carbon dioxide) concentration and the reference value Vs. The determination unit 230 can determine the state S of the operator 310 based on the CO2 (carbon dioxide) concentration after the control device 400. The display unit 410 can display the state S. Thus, the operator 310 can confirm whether his own state S has become the desired state S.

[0220] The control unit 290 can control the device 400 based on the change from the CO2 (carbon dioxide) concentration before the device 400 is controlled to the CO2 (carbon dioxide) concentration after the device 400 is controlled. The determination unit 230 can determine the state S of the operator 310 after the device 400 is controlled. The control unit 290 can control the device 400 based on the state S of the operator 310. Thus, the operator 310 can confirm whether the device 400 is controlled so that its own state S becomes the desired state S.

[0221] Operation information acquisition unit 240 (see Fig.19 ) obtains the operation information of the operator 310 on the device 400. The operation information is set to the operation information Ip. For example, in the case where the device 40 is a sporting device that causes the operator 310 to be in a state of motion by the action of the device 400, the operation information Ip is information that the operator 310 operates the motion state of the device 400. The operation information Ip is, for example, information that the motion state of the sporting device is enhanced or weakened. Enhancing the motion state of the sporting device means, for example, that the operator 310 performs an operation to increase the input power to the sporting device. Weakening the motion state of the sporting device means, for example, that the operator 310 performs an operation to reduce the input power to the sporting device.

[0222] For example, when the device 400 is a treadmill, if the operator 310 feels that the speed of the walking surface of the treadmill is high, the operator 310 may operate the device 400 to reduce the speed of the walking surface through the operating unit 440. In this case, the operation information Ip is information that the operator 310 has operated to reduce the speed of the walking surface.

[0223] The determination unit 230 (see Fig.19 ) can determine the state S of the operator 310 based on the CO2 (carbon dioxide) concentration in the exhaled breath of the operator 310 and the operation information Ip. The state S of the operator 310 can be reflected in the operation information Ip. Therefore, the determination unit 230 can determine the state S of the operator 310 based on the operation information Ip. In the case where the device 400 is a treadmill, the determination unit 230 can determine the state S related to the exercise load of the operator 310 based on the operation information Ip.

[0224] The control unit 290 can control the device 400 based on the determined state S. For example, when the device 400 is a treadmill, if it is determined that the state S of the operator 310 is an anaerobic exercise state, the control unit 290 controls the device 400 to increase the speed of the walking surface of the treadmill so that the CO2 (carbon dioxide) concentration in the exhaled air of the operator 310 becomes the concentration in the case of aerobic exercise.

[0225] When the device 400 is a sports equipment, the display unit 210 can display a response to the operation of the device 400 by the operator 310 based on the state S of the operator 310 based on the CO2 (carbon dioxide) concentration determined by the determination unit 230 and the operation information Ip. For example, when it is determined that the state S is a sports state and the operation information Ip is information that the motion state of the sports equipment is enhanced, the display unit 210 displays a message such as "You are in good condition" to the operator 310 as a response to the operation of the device 400. For example, when it is determined that the state S is a sports state and the operation information Ip is information that the motion state of the sports equipment is weakened, the display unit 210 displays a message such as "Thank you for your hard work" to the operator 310 as a response to the operation of the device 400. For example, when it is determined that the state S is a resting state and the operation information Ip is information that the motion state of the sports equipment is enhanced, the display unit 210 displays a message such as "Come on, cheer up" to the operator 310 as a response to the operation of the device 400. For example, when it is determined that the state S is a resting state and the operation information Ip is information that the motion of the exercise equipment is reduced, the display unit 210 displays a message such as “No exercise?” to the operator 310 as a response to the operation on the device 400 .

[0226] Fig.21 2 is a diagram showing an example of the relationship between the CO 2 (carbon dioxide) concentration in the exhaled air of the operator 310 and the exhaled volume of the operator 310. The exhaled volume is referred to as the exhaled volume Vb. Fig.17) obtains the expired volume Vb. The discriminating unit 230 can discriminate the state S of the operator 310 based on the CO2 (carbon dioxide) concentration and the expired volume Vb. The discriminating unit 230 can discriminate that the operator 310 is in motion when the expired volume Vb is above a predetermined threshold value Vth. The discriminating unit 230 can discriminate that the operator 310 is in a resting state when the expired volume Vb is less than the threshold value Vth. The discriminating unit 230 can also discriminate that the operator 310 is in motion when the CO2 (carbon dioxide) concentration in the expired air is above a predetermined threshold value Cth. The discriminating unit 230 can also discriminate that the operator 310 is in a resting state when the CO2 (carbon dioxide) concentration is less than the threshold value Cth. Fig.21 The CO 2 (carbon dioxide) concentration Vs in FIG. 3 is a reference value Vs (described above) when the operator 310 is in a moving state.

[0227] The determination unit 230 (see Fig.19 ) can be used to determine whether the operator 310 is in an anaerobic exercise state or an aerobic exercise state based on a predetermined relationship between the CO2 (carbon dioxide) concentration in the operator's breath and the exhaled volume Vb. The predetermined relationship between the CO2 (carbon dioxide) concentration in the operator's breath and the exhaled volume Vb is, for example, Fig.21 The relationship shown.

[0228] As described above, the longer the exhalation cycle, the easier it is for the exhalation volume Vb (described later) per exhalation to become larger, and the shorter the exhalation cycle, the easier it is for the exhalation volume Vb per exhalation to become smaller. Fig.19 ) can also determine whether the operator 310 is in an anaerobic exercise state or an aerobic exercise state based on a predetermined relationship between the CO2 (carbon dioxide) concentration in the operator's 310 breath and the exhalation cycle.

[0229] exist Fig.21 In the figure, the thick dotted line represents the state of anaerobic exercise, and the single-dot chain line represents the state of aerobic exercise. As the expired volume Vb increases, the CO2 (carbon dioxide) concentration tends to increase. When the expired volume Vb is greater than the expired volume Vbc, the operator 310 tends to be in the state of anaerobic exercise. When the expired volume Vb is less than the expired volume Vbc, the operator 310 tends to be in the state of aerobic exercise. When the CO2 (carbon dioxide) concentration in the expired air is greater than the reference value Vs, the operator 310 tends to be in the state of anaerobic exercise. When the CO2 (carbon dioxide) concentration in the expired air is less than the reference value Vs, the operator 310 tends to be in the state of aerobic exercise. The rate of increase of the CO2 (carbon dioxide) concentration per unit expired air volume in the case of anaerobic exercise tends to be greater than the rate of increase of the CO2 (carbon dioxide) concentration per unit expired air volume in the case of aerobic exercise.

[0230] The determination unit 230 (see Fig.19 ) can determine whether the operator 310 is in an anaerobic exercise state or an aerobic exercise state based on the expiratory volume Vbc. When the expiratory volume Vb is greater than the expiratory volume Vbc, the determination unit 230 can determine that the operator 310 is in an anaerobic exercise state. When the expiratory volume Vb is less than the expiratory volume Vbc, the determination unit 230 can determine that the operator 310 is in an aerobic exercise state. The determination unit 230 (refer to Fig.19 ) can also determine whether the operator 310 is in an anaerobic exercise state or an aerobic exercise state based on the exhalation cycle corresponding to the exhalation volume Vbc.

[0231] The determination unit 230 (see Fig.19 ) can determine whether the operator 310 is in an anaerobic exercise state or an aerobic exercise state based on the reference value Vs. When the CO2 (carbon dioxide) concentration in the exhaled air is greater than the reference value Vs, the determination unit 230 can determine that the operator 310 is in an anaerobic exercise state. When the CO2 (carbon dioxide) concentration in the exhaled air is less than the reference value Vs, the determination unit 230 can determine that the operator 310 is in an aerobic exercise state.

[0232] Identification unit 250 (see Fig.19 ) identifies the operator 310. The identification unit 250 may be provided in the housing of the HMD (head mounted) type display unit 210. The identification unit 250 identifies the operator 310 by, for example, recognizing the face of the operator 310. The identification unit 250 may identify a specific one of the multiple operators 310.

[0233] Identification unit 450 (see Fig. 20 ) identifies the operator 310. The recognition unit 450 can recognize the operator 310 by recognizing the face of the operator 310. The recognition unit 450 can recognize a specific operator 310 among the plurality of operators 310. The control unit 430 (refer to Fig. 20 ) can generate identification information of the operator 310 identified by the identification unit 450. This identification information is referred to as identification information Ir.

[0234] The transceiver unit 420 (see Fig. 20 ) can send the identification information Ir. The transceiver 420 can send the identification information Ir wirelessly. The operation information acquisition unit 240 (refer to Fig.19 ) can obtain the identification information Ir. The identification unit 250 (refer to Fig.19 ) can identify the operator 310 based on the identification information Ir.

[0235] The relationship between the CO2 (carbon dioxide) concentration in the exhaled air and the exhaled volume Vb or the exhalation cycle may be predetermined for each of the plurality of operators 310. The relationship between the CO2 (carbon dioxide) concentration in the exhaled air and the exhaled volume Vb or the exhalation cycle may be different for each operator 310. The relationship between the CO2 (carbon dioxide) concentration in the exhaled air and the exhaled volume Vb or the exhalation cycle of each of the plurality of operators 310 may be stored in the storage unit 270 (see Fig.19 ).

[0236] The determination unit 230 (see Fig.19 ) can determine whether the operator 310 is in an anaerobic exercise state or an aerobic exercise state based on the relationship between the CO2 (carbon dioxide) concentration in the exhaled air and the exhaled volume Vb or the exhalation cycle of the operator 310 identified by the identification unit 250. Thus, the identification unit 230 can determine for each operator 310 whether the operator 310 is in an anaerobic exercise state or an aerobic exercise state.

[0237] When the exhaled volume Vb is less than the threshold value Vth, the determination unit 230 (see Fig.19 ) can determine the emotion of the operator 310 based on the CO2 (carbon dioxide) concentration in the exhaled air. As described above, the case where the exhaled volume Vb is less than the threshold value Vth refers to the case where the operator 310 is in a resting state. In the case where the exhaled volume Vb is less than the threshold value Vth, the CO2 (carbon dioxide) concentration in the exhaled air of the operator 310 may depend on the emotion of the operator 310. In the case where the exhaled volume Vb is less than the threshold value Vth, when the CO2 (carbon dioxide) concentration in the exhaled air of the operator 310 is greater than the threshold value Dth, the determination unit 230 can determine the state S of the operator 310 as an uneasy state, and when the CO2 (carbon dioxide) concentration is less than the threshold value Dth, the determination unit 230 can determine the state S of the operator 310 as a reassuring state.

[0238] The biological information acquisition unit 260 (see Fig.19 ) acquires biological information of the operator 310. The biological information is set as biological information Ig. The biological information Ig may include at least one of the heartbeat information, sweat amount information, body temperature information, and electromyograph information of the operator 310. The biological information acquisition unit 260 may be provided in the housing of the HMD (head mounted) type display unit 210.

[0239] When the exhaled volume Vb is less than the threshold value Vth, the determination unit 230 (see Fig.19) can judge the emotion of the operator 310 based on the CO2 (carbon dioxide) concentration in the exhaled air and the biological information Ig. For example, when the operator 310 is in an uneasy state, the operator 310 is likely to be in a state where the sympathetic nerves are dominant over the parasympathetic nerves. When the sympathetic nerves are dominant over the parasympathetic nerves, the heartbeat variation of the operator 310 is likely to become smaller. For example, when the operator 310 is in a reassuring state, the operator 310 is likely to be in a state where the parasympathetic nerves are dominant over the sympathetic nerves. When the parasympathetic nerves are dominant over the sympathetic nerves, the heartbeat variation of the operator 310 is likely to become larger.

[0240] The magnitude of the first power spectrum of the heartbeat of the operator 310 is set to LF, and the magnitude of the second power spectrum is set to HF. The frequency band of the second power spectrum is a frequency band having a higher frequency than the frequency band of the first power spectrum. The frequency band of the first power spectrum is, for example, greater than 0.05 Hz and less than 0.20 Hz. The frequency band of the second power spectrum is, for example, greater than 0.20 Hz and less than 0.35 Hz.

[0241] The biological information acquisition unit 260 (see Fig.19 ) can obtain the LF and HF of the heartbeat of the operator 310. When the ratio of LF to HF (LF / HF) is greater than or equal to a predetermined threshold value Nth, the determination unit 230 (refer to Fig.19 ) can be determined that the state S of the operator 310 is a state in which the sympathetic nerve is dominant over the parasympathetic nerve. When the ratio of LF to HF (LF / HF) is less than the threshold value Nth, the determination unit 230 can determine that the state S of the operator 310 is a state in which the parasympathetic nerve is dominant over the sympathetic nerve.

[0242] When the state S of the operator 310 is that the sympathetic nerves are dominant over the parasympathetic nerves, the exhalation volume Vb of the operator 310 tends to become larger, or the exhalation cycle tends to become longer. When the state S of the operator 310 is that the parasympathetic nerves are dominant over the sympathetic nerves, the exhalation volume Vb of the operator 310 tends to become smaller, or the exhalation cycle tends to become shorter.

[0243] In the case where the sympathetic nerves are dominant over the parasympathetic nerves due to the operator 310 being in a state of anxiety or fear, the operator 310 may become in a state of respiratory alkalosis. The state of respiratory alkalosis refers to a state in which excessive CO2 (carbon dioxide) is discharged due to overbreathing, etc. In the case where the operator 310 is in a state of respiratory alkalosis, the heart rate, sweating amount, and respiratory rate of the operator 310 are likely to increase, the muscles are likely to become stiff, the body temperature (especially the body temperature of the hands and feet) is likely to decrease, and the end-tidal carbon dioxide concentration is likely to decrease. That is, in the case where the operator 310 is in a state of anxiety or fear, the heart rate, sweating amount, and respiratory rate are likely to increase, the amplitude of the myoelectric potential is likely to increase, and the CO2 (carbon dioxide) concentration in the exhaled air is likely to decrease.

[0244] When the operator 310 is in an excited state, angry state, or a highly aggressive state, the operator 310 may become a state of respiratory acidosis. The state of respiratory acidosis refers to a state in which CO2 (carbon dioxide) accumulates due to a deterioration in the respiratory state. When the operator 310 is in a state of respiratory acidosis, the body temperature (especially the body temperature of the head, chest, or hands) is likely to rise, and the end-tidal carbon dioxide concentration is likely to rise. That is, when the operator 310 is in an excited state, angry state, or a highly aggressive state, the heart rate and sweating amount are likely to increase, the respiratory rate and respiratory volume Vb are likely to decrease, and the CO2 (carbon dioxide) concentration in the exhaled air is likely to rise.

[0245] The determination unit 230 can determine whether the exhalation volume Vb of the operator 310 is greater than or less than the threshold value Vth based on the biological information Ig. The determination unit 230 can determine the emotion of the operator 310 based on the determined exhalation volume Vb and the CO2 (carbon dioxide) concentration in the exhaled air.

[0246] The determination unit 230 (see Fig.19 ) can identify the application being started by the display device 300. The distinguishing unit 230 can distinguish the type of application being started by the display device 300. The distinguishing unit 230 can distinguish the state S of the operator 310 based on the distinguished application. For example, when the application being started by the display device 300 is an application related to sports, such as running, walking, etc., it is highly likely that the state S of the operator 310 is a sports state. For example, when the application being started by the display device 300 is not an application related to sports, such as go, chess, or international chess, it is highly likely that the state S of the operator 310 is a resting state. Therefore, the distinguishing unit 230 can distinguish the state S of the operator 310 based on the application.

[0247] The determination unit 230 can determine the type of application being activated by the display device 300. The type of application refers to, for example, whether the application is an application that is closely related to exercise, such as running and walking, or an application that is less closely related to exercise, such as go, chess, and international chess. An application that is closely related to exercise means an application that is likely to cause the operator 310 to be in an exercise state by using the application. An application that is less closely related to exercise means an application that is likely to cause the operator 310 to be in a resting state while the operator 310 is using the application. The determination unit 230 can estimate the state of the operator 310 based on the determined type of application. The determination unit 230 can estimate whether the state of the operator 310 is an exercise state or a resting state based on the determined type of application.

[0248] The determination unit 230 can determine whether the state S of the operator 310 based on the CO2 (carbon dioxide) concentration acquired by the CO2 (carbon dioxide) sensor 220 is consistent with the state of the operator 310 estimated based on the type of application. In the case where the state S of the operator 310 based on the CO2 (carbon dioxide) concentration is different from the state of the operator 310 estimated based on the type of application, the display unit 210 can display information that prompts the application that is being started to end. For example, although the state estimated based on the type of application is a resting state, the state S based on the CO2 (carbon dioxide) concentration is a moving state, the operator 310 may, for example, play Go while walking using a smart phone. Therefore, the actions of the operator 310 may cause trouble to the surroundings. Therefore, the display unit 210 can display information that prompts the application that is being started to end.

[0249] For example, in the case where the application is an application for obtaining exercise information such as running, the determination unit 230 can determine that the application is an application that is highly related to exercise. The determination unit 230 can estimate the state of the operator 310 as an exercise state based on the type of the application. Although the determination unit 230 estimates the state of the operator 310 as an exercise state based on the type of application, if the state S based on the CO2 (carbon dioxide) concentration is a resting state, the operator 310 may not be exercising sufficiently. Therefore, the display unit 210 can display information for causing the operator 310 to start exercising, or information for prompting the operator 310 to exercise.

[0250] The CO2 (carbon dioxide) concentration acquired by the CO2 (carbon dioxide) sensor 220 can be controlled by the control unit 290 (see Fig.19 ) or in an application installed in the display device 300. The CO2 (carbon dioxide) concentration acquired by the CO2 (carbon dioxide) sensor 220 can be transmitted by the transmitting unit 280 (see Fig.19 ) is sent to the device 400, and the transceiver 420 (refer to Fig. 20 ) can receive the CO2 (carbon dioxide) concentration. The control unit 430 (refer to Fig. 20 ) can calculate the CO2 (carbon dioxide) concentration. The transceiver 420 (refer to Fig. 20 ) can send the calculated CO2 (carbon dioxide) concentration. Fig.19 ) can receive the CO2 (carbon dioxide) concentration sent by the transceiver 420. The determination unit 230 can be based on the operation information Ip (refer to Fig.19 ) and the CO2 (carbon dioxide) concentration acquired by the operation information acquisition unit 240 to determine the state S of the operator 310.

[0251] When the display device 300 includes a plurality of CO2 (carbon dioxide) sensors 220, one CO2 (carbon dioxide) sensor 220 can obtain the CO2 (carbon dioxide) concentration of the exhaled breath accompanied by the utterance of the operator 310, and the other CO2 (carbon dioxide) sensors 220 can obtain the CO2 (carbon dioxide) concentration of the exhaled breath not accompanied by the utterance of the operator 310. Fig.17 In the example, CO2 (carbon dioxide) sensor 220-2 obtains the CO2 (carbon dioxide) concentration of the exhaled breath accompanied by the utterance of the operator 310, and CO2 (carbon dioxide) sensor 220-1 obtains the CO2 (carbon dioxide) concentration of the exhaled breath not accompanied by the utterance of the operator 310.

[0252] The display device 300 may include a sound acquisition unit that acquires the utterance of the operator 310. Fig.17 In the example of , CO2 (carbon dioxide) sensor 220-2 may be included in the sound acquisition unit. CO2 (carbon dioxide) sensor 220-2 may be arranged near the mouth of operator 310 more closely than CO2 (carbon dioxide) sensor 220-1. CO2 (carbon dioxide) sensor 220-1 may be arranged farther from the mouth of operator 310 than CO2 (carbon dioxide) sensor 220-2. Fig.17 In the example, the CO 2 (carbon dioxide) sensor 220 - 1 is configured on the head of the operator 310 .

[0253] The CO2 (carbon dioxide) sensor 220-1 may be installed in a room where the operator 310 is located, separate from the display device 300. When the CO2 (carbon dioxide) sensor 220-1 is installed in the room where the operator 310 is located, the CO2 (carbon dioxide) concentration measured by the CO2 (carbon dioxide) sensor 220-1 may be wirelessly transmitted to the display device 300.

[0254] The determination unit 230 (see Fig.19) can determine the state S of the operator 310 based on the CO2 (carbon dioxide) concentration acquired by one CO2 (carbon dioxide) sensor 220 and the CO2 (carbon dioxide) concentration acquired by other CO2 (carbon dioxide) sensors 220. The difference between the CO2 (carbon dioxide) concentration acquired by one CO2 (carbon dioxide) sensor 220 and the CO2 (carbon dioxide) concentration acquired by other CO2 (carbon dioxide) sensors 220 is set as a difference d. The determination unit 230 can determine the state S of the operator 310 based on the difference d.

[0255] When the difference d is greater than the threshold dth, the determination unit 230 may determine that the state S of the operator 310 is an excited state. When the operator 310 is excited, the difference d tends to become larger. When the difference d is less than the threshold dth, the determination unit 230 may determine that the state S of the operator 310 is a relaxed state. When the operator 310 is relaxed, the difference d tends to become smaller.

[0256] Fig. 22 FIG. 1 is a flowchart showing an example of a display method according to an embodiment of the present invention. Fig.19 The display method involved in one embodiment of the present invention is described by taking the display device shown as an example. The display method includes a CO2 (carbon dioxide) concentration acquisition step S200 and a display step S210. The display method may include an exhaled volume acquisition step S201, a biological information acquisition step S202, an operation information acquisition step S204, an identification step S206, a determination step S208, a control step 1102, a control step S212, a determination step S214, and a determination step S216.

[0257] The CO2 concentration acquisition step S200 is a step in which the CO2 sensor 220 acquires the CO2 concentration in the exhaled breath of the operator 310 who operates the head-mounted display unit 210. The display step S210 is a step in which the display unit 210 displays the state S of the operator 310 based on the CO2 concentration.

[0258] The determination step S208 may be a step in which the determination unit 230 determines the state S of the operator 310 based on the CO2 (carbon dioxide) concentration acquired in the CO2 (carbon dioxide) concentration acquisition step S200. The display step S210 may be a step in which the display unit 210 displays the state S of the operator 310 based on the CO2 (carbon dioxide) concentration determined in the determination step S208.

[0259] The display step S210 may include a control step S2102. The control step S2102 may be a step in which the control unit 290 controls the display unit 210 based on the state S of the operator 310 determined in the determination step S208. The control step S2102 may also be a step in which the control unit 290 controls the display unit 210 based on the CO2 (carbon dioxide) concentration acquired in the CO2 (carbon dioxide) concentration acquisition step S200 and the reference value Vs of the CO2 (carbon dioxide) concentration.

[0260] The determination step S214 is a step in which the determination unit 230 determines whether the CO2 (carbon dioxide) concentration is acquired after the control step S2102. If it is determined that the CO2 (carbon dioxide) concentration is acquired, the display method returns to the CO2 (carbon dioxide) concentration acquisition step S200. If it is determined that the CO2 (carbon dioxide) concentration is not acquired, the display method ends.

[0261] After the display unit 210 is controlled based on the CO2 (carbon dioxide) concentration and the reference value Vs in the control step S2102, the CO2 (carbon dioxide) concentration acquisition step S200 may be a step in which the CO2 (carbon dioxide) sensor 220 further acquires the CO2 (carbon dioxide) concentration. The control step S2102 may be a step in which the control unit 290 controls the display unit 210 based on a change from the CO2 (carbon dioxide) concentration before the display unit 210 is controlled to the CO2 (carbon dioxide) concentration after the display unit 210 is controlled.

[0262] The control step S212 may be a step in which the control unit 290 controls the device 400 used by the operator 310 based on the state S of the operator 310 determined in the determination step S208. The control step S212 may also be a step in which the control unit 290 controls the device 400 based on the CO2 (carbon dioxide) concentration acquired in the CO2 (carbon dioxide) concentration acquisition step S200 and the reference value Vs of the CO2 (carbon dioxide) concentration.

[0263] The determination step S216 is a step in which the determination unit 230 determines whether the CO2 (carbon dioxide) concentration is acquired after the control step S212. If it is determined that the CO2 (carbon dioxide) concentration is acquired, the display method returns to the CO2 (carbon dioxide) concentration acquisition step S200. If it is determined that the CO2 (carbon dioxide) concentration is not acquired, the display method ends.

[0264] After the device 400 is controlled based on the CO2 (carbon dioxide) concentration and the reference value Vs in the control step S212, the CO2 (carbon dioxide) concentration acquisition step S200 may be a step in which the CO2 (carbon dioxide) sensor 220 further acquires the CO2 (carbon dioxide) concentration. The control step S212 may be a step in which the control unit 290 controls the device 400 based on a change from the CO2 (carbon dioxide) concentration before the device 400 is controlled to the CO2 (carbon dioxide) concentration after the device 400 is controlled.

[0265] The operation information acquisition step S204 is a step in which the operation information acquisition unit 240 acquires the operation information Ip of the operator 310 operating the device 400. The determination step S208 may be a step in which the determination unit 230 determines the state S of the operator 310 based on the CO2 (carbon dioxide) concentration and the operation information Ip. In the case where the device 400 is a sports equipment, the display step S210 may be a step in which the display unit 210 displays the reaction of the operator 310 to the operation of the device 400 based on the state S of the operator 310 based on the CO2 (carbon dioxide) concentration determined in the determination step 208 and the operation information Ip.

[0266] The exhaled volume acquisition step S201 is a step in which the exhaled volume sensor 224 further acquires the exhaled volume Vb or the exhaled cycle of the operator 310. The determination step S208 may be a step in which the determination unit 230 determines the state S of the operator 310 based on the CO2 (carbon dioxide) concentration and the exhaled volume Vb or the exhaled cycle. The determination step S208 may be a step in which the determination unit 230 determines whether the operator 310 is in an anaerobic exercise state or an aerobic exercise state based on a predetermined relationship between the CO2 (carbon dioxide) concentration and the exhaled volume Vb or the exhaled cycle.

[0267] The identification step S206 is a step in which the identification unit 250 identifies the operator 310. The relationship between the CO2 (carbon dioxide) concentration and the exhalation volume Vb or the exhalation cycle can be pre-defined for each of the multiple operators 310. The discrimination step S208 can be a step in which the discrimination unit 230 discriminates whether the identified operator 310 is in an anaerobic exercise state or an aerobic exercise state based on the relationship between the CO2 (carbon dioxide) concentration and the exhalation volume Vb or the exhalation cycle of the operator 310 identified in the identification step S206. When the exhalation volume Vb is less than the threshold value Vth, the discrimination step S208 can be a step in which the discrimination unit 230 discriminates the emotion of the operator 310 based on the CO2 (carbon dioxide) concentration.

[0268] The biological information acquisition step S202 is a step in which the biological information acquisition unit 260 acquires the biological information Ig of the operator 310. The determination step S208 may be a step in which the determination unit 230 determines the emotion of the operator 310 based on the CO2 (carbon dioxide) concentration and the biological information Ig.

[0269] The determination step S208 may be a step in which the determination unit 230 determines an application being activated by the display device 300 and determines the state S of the operator 310 based on the determined application.

[0270] The determination step S208 may be a step in which the determination unit 230 determines the type of application being activated by the display device 300. The determination step S208 may be a step in which the determination unit 230 determines whether the state S of the operator 310 based on the CO2 (carbon dioxide) concentration acquired by the CO2 (carbon dioxide) sensor 220 is consistent with the state of the operator 310 estimated based on the type of application. The display step S210 may be a step in which, when the state S of the operator 310 based on the CO2 (carbon dioxide) concentration is different from the state of the operator 310 estimated based on the type of application, the display unit 210 displays information prompting the application being activated to end.

[0271] The CO2 (carbon dioxide) concentration acquisition step S200 may be a step in which one CO2 (carbon dioxide) sensor 220-2 acquires the CO2 (carbon dioxide) concentration of the exhaled breath accompanied by the utterance of the operator 310, and another CO2 (carbon dioxide) sensor 220-1 acquires the CO2 (carbon dioxide) concentration of the exhaled breath not accompanied by the utterance of the operator 310. The determination step S208 may be a step in which the determination unit 230 determines the state S of the operator 310 based on the CO2 (carbon dioxide) concentration acquired by one CO2 (carbon dioxide) sensor 220-2 and the CO2 (carbon dioxide) concentration acquired by another CO2 (carbon dioxide) sensor 220-1.

[0272] Fig.23 1 is a diagram showing an example of a computer 2200 that can embody the breath detection system 100 or the display device 300 involved in one embodiment of the present invention in whole or in part. The program installed in the computer 2200 can cause the computer 2200 to function as an operation associated with the breath detection system 100 or the display device 300 involved in the embodiment of the present invention, or one or more sections of the breath detection system 100 or the display device 300, or can cause the computer 2200 to execute the operation or the one or more sections, or can cause the computer 2200 to execute each stage involved in the display method of the present invention (see Fig.10 , Fig.11 , Fig. 22The program can be executed by the CPU 2212 to cause the computer 2200 to execute the flowchart described in this specification ( Fig.10 , Fig.11 , Fig. 22 ) and the block diagram ( Fig.13 , Fig.16 , Fig.19 ) is a specific operation associated with several or all blocks in the .

[0273] A computer 2200 according to an embodiment of the present invention includes a CPU 2212, a RAM 2214, a graphics controller 2216, and a display device 2218. The CPU 2212, the RAM 2214, the graphics controller 2216, and the display device 2218 are connected to each other through a main controller 2210. The computer 2200 also includes input and output units such as a communication interface (I / F) 2222, a hard disk drive 2224, a DVD-ROM drive 2226, and an IC card drive. The communication interface 2222, the hard disk drive 2224, the DVD-ROM drive 2226, and the IC card drive are connected to the main controller 2210 via an input and output (I / O) controller 2220. The computer also includes conventional input and output units such as a ROM 2230 and a keyboard 2242. The ROM 2230 and the keyboard 2242 are connected to the input and output controller 2220 via an input and output (I / O) chip 2240.

[0274] The CPU 2212 controls each unit by operating according to the programs stored in the ROM 2230 and the RAM 2214. The graphic controller 2216 displays the image data on the display device 2218 by acquiring the image data generated by the CPU 2212 in a frame buffer or the like provided in the RAM 2214 or in the RAM 2214.

[0275] The communication interface 2222 communicates with other electronic devices via a network. The hard disk drive 2224 stores programs and data used by the CPU 2212 in the computer 2200. The DVD-ROM drive 2226 reads programs or data from the DVD-ROM 2201 and provides the read programs or data to the hard disk drive 2224 via the RAM 2214. The IC card drive reads programs and data from an IC card or writes programs and data to an IC card.

[0276] The ROM 2230 stores a boot program or the like executed by the computer 2200 at activation, or a program depending on the hardware of the computer 2200. The input / output chip 2240 can connect various input / output units to the input / output controller 2220 via a parallel port, a serial port, a keyboard port, a mouse port, and the like.

[0277] The program is provided by a computer-readable medium such as DVD-ROM 2201 or an IC card. The program is read from the computer-readable medium and installed in the hard disk drive 2224, RAM 2214 or ROM 2230, which is also an example of a computer-readable medium, and executed by the CPU 2212. The information processing described in these programs is read by the computer 2200, resulting in cooperation between the program and the various types of hardware resources described above. The device or method can be constructed by implementing the operation or processing of information according to the use of the computer 2200.

[0278] For example, when communication is performed between the computer 2200 and an external device, the CPU 2212 can execute the communication program loaded into the RAM 2214, and instruct the communication process based on the process described in the communication program to the communication interface 2222. Under the control of the CPU 2212, the communication interface 2222 reads the transmission data stored in the transmission buffer processing area provided in the RAM 2214, the hard disk drive 2224, the DVD-ROM 2201, or a recording medium such as an IC card, and transmits the read transmission data to the network, or writes the reception data received from the network to the reception buffer processing area provided on the recording medium, etc.

[0279] The CPU 2212 can read all or a required part of a file or database stored in an external recording medium such as the hard disk drive 2224, the DVD-ROM drive 2226 (DVD-ROM 2201), an IC card, etc. into the RAM 2214. The CPU 2212 can perform various types of processing on the data on the RAM 2214. Then, the CPU 2212 can write the processed data back to the external recording medium.

[0280] Various types of information such as various types of programs, data, tables, and databases can be stored in the recording medium and information processing can be performed. The CPU 2212 can perform various types of processing described in the present disclosure, including various types of operations specified by the instruction sequence of the program, information processing, conditional judgment, conditional branching, unconditional branching, retrieval or replacement of information, etc., on the data read from the RAM 2214. The CPU 2212 can write the result back to the RAM 2214.

[0281] The CPU 2212 can search for information in a file, database, etc. in the recording medium. For example, in the case where a plurality of entries each having an attribute value of a first attribute associated with an attribute value of a second attribute are stored in the recording medium, the CPU 2212 can search for an entry that matches the condition and to which an attribute value of the first attribute is specified from among the plurality of entries, and read the attribute value of the second attribute stored in the entry, and by reading the second attribute value, obtain the attribute value of the second attribute associated with the first attribute that satisfies the predetermined condition.

[0282] The above-mentioned program or software module may be stored on the computer 2200 or on a computer-readable medium of the computer 2200. A recording medium such as a hard disk or RAM provided in a server system connected to a dedicated communication network or the Internet can be used as a computer-readable medium. The program may be provided to the computer 2200 via the recording medium.

[0283] The present invention has been described above using the embodiments, but the protection scope of the present invention is not limited to the scope described in the above embodiments. It is obvious to those skilled in the art that various changes or improvements can be made to the above embodiments. As is clear from the claims, the modes obtained by applying such changes or improvements can also be included in the protection scope of the present invention.

[0284] [Item 1-1]

[0285] A breath detection system comprising:

[0286] Main body;

[0287] a breath sensor disposed in the main body, the breath sensor having two operation modes with different power consumptions and used for detecting breath; and

[0288] A control unit controls an operation mode of the breath sensor based on a state of at least one of the main body and the breath sensor.

[0289] [Item 1-2]

[0290] According to the breathalyzer system described in item 1-1,

[0291] The main body has:

[0292] a fixed portion; and

[0293] a movable part, which is movably provided relative to the fixed part, and the breath sensor is provided on the movable part,

[0294] The control unit controls the operation mode of the breath sensor based on a state of the movable unit.

[0295] [Items 1-3]

[0296] According to the breath detection system described in item 1-2,

[0297] The movable part has a sound detection part for detecting sound.

[0298] [Items 1-4]

[0299] According to the breathalyzer system described in item 1-1,

[0300] The main body has a sound detection part for detecting sound.

[0301] The control unit controls the operation mode of the breath sensor based on the state of the sound detected by the sound detection unit.

[0302] [Items 1-5]

[0303] According to the breathalyzer system described in item 1-1,

[0304] The main body has a temperature detection part for detecting temperature.

[0305] The control unit controls the operation mode of the breath sensor based on the temperature detected by the temperature detection unit.

[0306] [Items 1-6]

[0307] According to the breathalyzer system described in item 1-1,

[0308] The main body has a distance detection part for detecting the distance to other objects.

[0309] The control unit controls the operation mode of the breath sensor based on the distance detected by the distance detection unit.

[0310] [Items 1-7]

[0311] According to the breathalyzer system described in item 1-1,

[0312] The state of the main body changes according to a control signal from the application software.

[0313] The control unit controls the operation mode of the breath sensor based on the control signal.

[0314] [Items 1-8]

[0315] According to the breathalyzer system described in item 1-1,

[0316] The main body has a battery for supplying power.

[0317] The control unit controls the operation mode of the breath sensor based on the remaining capacity of the battery.

[0318] [Items 1-9]

[0319] According to the breathalyzer system described in item 1-1,

[0320] The main body has a plurality of operation states with different power consumption.

[0321] The control unit controls the operation mode of the breath sensor based on an operation state of the main body.

[0322] [Items 1-10]

[0323] According to the breathalyzer system described in item 1-1,

[0324] The control unit controls the operation mode of the breath sensor based on the breath detected by the breath sensor.

[0325] [Items 1-11]

[0326] A breathalyzer according to any one of items 1-1 to 1-10,

[0327] The breath sensor has, as the operation mode, an active state capable of detecting breath and a standby state in which power consumption is less than that in the active state.

[0328] The control unit controls the operation mode of the breath sensor based on a state of the main body.

[0329] [Items 1-12]

[0330] A breathalyzer system as described in item 1-11,

[0331] the control unit controls the operation mode of the breath sensor by comparing a state value indicating a state of the main body with a set reference value,

[0332] The reference value when the breath sensor is shifted from the active state to the standby state is different from the reference value when the breath sensor is shifted from the standby state to the active state.

[0333] [Items 1-13]

[0334] A breathalyzer system as described in item 1-11,

[0335] The main body has a plurality of states, each of which is changeable.

[0336] The control unit controls the state of the breath sensor based on the different types of states of the main body when changing the breath sensor from the active state to the standby state and when changing the breath sensor from the standby state to the active state.

[0337] [Items 1-14]

[0338] A breathalyzer system as described in item 1-11,

[0339] The control unit adjusts a determination criterion of the state of the main body when controlling the operation mode of the breath sensor this time, based on the state of the main body used in determination when controlling the operation mode of the breath sensor last time.

[0340] [Items 1-15]

[0341] A breathalyzer according to any one of items 1-1 to 1-10,

[0342] The main body has a plurality of states, each of which is changeable.

[0343] The control unit controls the operation mode of the breath sensor based on the two or more types of states of the main body.

[0344] [Items 1-16]

[0345] A breathalyzer according to any one of items 1-1 to 1-10,

[0346] The breath sensor comprises:

[0347] a light emitting unit configured to emit light toward a path through which the exhaled air passes; and

[0348] The first light receiving unit receives at least a portion of the light emitted by the light emitting unit and outputs a first light receiving signal corresponding to a light receiving result.

[0349] [Item 2-1]

[0350] A display device comprising:

[0351] a head-mounted display unit; and

[0352] A carbon dioxide sensor is configured to obtain a carbon dioxide concentration in the breath of an operator of the display unit.

[0353] [Item 2-2]

[0354] The display device according to item 2-1,

[0355] further comprising a determination unit that determines the state of the operator based on the carbon dioxide concentration,

[0356] The display unit displays the state of the operator determined by the determination unit.

[0357] [Item 2-3]

[0358] According to the display device described in item 2-2,

[0359] A control unit is further provided for controlling the display unit based on the state of the operator determined by the determination unit.

[0360] [Item 2-4]

[0361] The display device according to item 2-3,

[0362] The control unit controls the display unit based on the carbon dioxide concentration and a reference value of the carbon dioxide concentration corresponding to the state of the operator.

[0363] [Item 2-5]

[0364] The display device according to item 2-4,

[0365] The carbon dioxide sensor further acquires the carbon dioxide concentration after the control unit controls the display unit based on the carbon dioxide concentration and the reference value,

[0366] The control unit controls the display unit based on a change from the carbon dioxide concentration before controlling the display unit to the carbon dioxide concentration after controlling the display unit.

[0367] [Item 2-6]

[0368] The display device according to item 2-1, further comprising:

[0369] a determination unit that determines a state of the operator based on the carbon dioxide concentration; and

[0370] A control unit controls the device used by the operator based on the state of the operator determined by the determination unit.

[0371] [Item 2-7]

[0372] The display device according to item 2-6,

[0373] The control unit controls the device based on the carbon dioxide concentration and a reference value of the carbon dioxide concentration corresponding to the state of the operator.

[0374] [Item 2-8]

[0375] The display device according to item 2-7,

[0376] The carbon dioxide sensor further acquires the carbon dioxide concentration after the control unit controls the device based on the carbon dioxide concentration and the reference value.

[0377] The control unit further controls the device based on a change from the carbon dioxide concentration before controlling the device to the carbon dioxide concentration after controlling the device.

[0378] [Item 2-9]

[0379] The display device according to item 2-6,

[0380] The equipment is a sports equipment,

[0381] The display device further includes an operation information acquisition unit for acquiring operation information of the operator on the device.

[0382] The display unit displays a response to the operator's operation of the device based on the state of the operator based on the carbon dioxide concentration determined by the determination unit and the operation information.

[0383] [Item 2-10]

[0384] The display device according to item 2-2 or 2-6,

[0385] The device further comprises an exhaled air volume sensor, wherein the exhaled air volume sensor obtains the exhaled air volume of the operator.

[0386] The determination unit determines the state of the operator based on the carbon dioxide concentration and the expired air volume.

[0387] [Item 2-11]

[0388] The display device according to item 2-10,

[0389] The determination unit determines whether the operator is performing anaerobic exercise or aerobic exercise based on a predetermined relationship between the carbon dioxide concentration and the expired air volume.

[0390] [Item 2-12]

[0391] The display device according to item 2-11,

[0392] further comprising a recognition unit for recognizing the operator,

[0393] predetermining the relationship for each of the plurality of operators,

[0394] The determination unit determines whether the operator identified by the recognition unit is in an anaerobic exercise state or an aerobic exercise state based on the relationship of the operator identified by the recognition unit.

[0395] [Item 2-13]

[0396] The display device according to item 2-10,

[0397] The determination unit determines the emotion of the operator based on the carbon dioxide concentration when the expired breath volume is smaller than a predetermined threshold value.

[0398] [Item 2-14]

[0399] The display device according to item 2-13,

[0400] further comprising a biological information acquisition unit for acquiring biological information of the operator,

[0401] The determination unit determines the emotion of the operator based on the carbon dioxide concentration and the biological information.

[0402] [Item 2-15]

[0403] The display device according to item 2-2 or 2-6,

[0404] The determination unit further determines the type of application being activated by the display device, and estimates the state of the operator based on the determined type of the application.

[0405] When the state of the operator based on the carbon dioxide concentration determined by the determination unit is different from the state of the operator estimated based on the type of the application, the display unit displays a message prompting the application being activated to be terminated.

[0406] [Item 2-16]

[0407] A display method, comprising:

[0408] An acquisition step in which the carbon dioxide sensor acquires the carbon dioxide concentration in the exhaled breath of an operator who operates the head-mounted display unit; and

[0409] In a display step, the display unit displays the state of the operator based on the carbon dioxide concentration.

[0410] [Item 2-17]

[0411] A display program for causing a computer to function as the display device according to any one of items 2-1 to 2-9.

[0412] Description of Reference Numerals

[0413] 10: Breath sensor; 11: Gas sensor; 12: Path; 14: Light; 16: Light emitting unit; 18: First light receiving unit; 20: Operation unit; 22: Second light receiving unit; 24: Optical filter; 30: Support member; 32: Reflector; 40: Substrate; 41: First main surface; 42: Second main surface; 44: Light emitting element; 100: Breath detection system; 102: Main body; 110: Fixing unit; 111: Connecting unit; 112: Sound generating unit ; 113: arm portion; 117: storage battery; 120: movable portion; 122: sound detection portion; 140: control portion; 150: state detection portion; 151: position state detection portion; 152: environment state detection portion; 153: action state detection portion; 154: wearing detection portion; 155: signal detection portion; 156: remaining capacity detection portion; 157: power consumption detection portion; 200: user; 210: display portion; 212: housing; 214 : bottom surface; 220: CO2 (carbon dioxide) sensor; 222: opening; 224: exhaled air volume sensor; 230: determination unit; 240: operation information acquisition unit; 250: identification unit; 260: biological information acquisition unit; 270: storage unit; 280: transmission unit; 290: control unit; 300: display device; 310: operator; 400: equipment; 410: display unit; 420: transceiver; 430: control unit; 440: operation unit ; 450: identification unit; 2200: computer; 2201: DVD-ROM; 2210: main controller; 2212: CPU; 2214: RAM; 2216: graphic controller; 2218: display device; 2220: input-output controller; 2222: communication interface; 2224: hard disk drive; 2226: DVD-ROM drive; 2230: ROM; 2240: input-output chip; 2242: keyboard.

Claims

1. An exhalation sensor for detecting exhalation produced by breathing, wherein the exhalation sensor is characterized by comprising: a light emitting unit configured to emit light toward a path through which the exhaled air passes; a first light receiving unit that receives at least a portion of the light emitted by the light emitting unit and outputs a first light receiving signal corresponding to a light receiving result; and a computing unit for computing the first light receiving signal; in, The calculation unit calculates a baseline of the waveform of the first light receiving signal based on a frequency component of the first light receiving signal lower than a set first cutoff frequency, and detects the exhalation based on a signal obtained by removing the baseline from the first light receiving signal.

2. The breath sensor according to claim 1, characterized in that The calculation unit calculates at least one of a cycle and a length of the breathing.

3. The breath sensor according to claim 1, characterized in that: The first cutoff frequency is set according to a change in a signal value of the first light receiving signal.

4. The breath sensor according to claim 1, characterized in that: The calculation unit sets the first cutoff frequency to be higher when the signal value of the first light receiving signal, which is the object of calculating the value of the baseline, increases relative to the past signal value in the time waveform of the first light receiving signal than when the signal value of the first light receiving signal, which is the object of calculating the value of the baseline, decreases relative to the past signal value.

5. The breath sensor according to claim 4, characterized in that: The calculation unit sets the first cutoff frequency to be higher when the signal value of the first light-receiving signal, which is the object of calculating the baseline value, increases by more than 20% relative to the past signal value in the time waveform of the first light-receiving signal than when the signal value of the first light-receiving signal, which is the object of calculating the baseline value, decreases by more than 20% relative to the past signal value.

6. The breath sensor according to claim 4, characterized in that: The calculation unit sets the first cutoff frequency to be at least 10 times higher when the signal value of the first light receiving signal, which is the object of calculating the baseline value, increases relative to the signal value at the immediately previous moment in the time waveform of the first light receiving signal than when the signal value of the first light receiving signal, which is the object of calculating the baseline value, decreases relative to the immediately previous signal value.

7. The breath sensor according to claim 6, characterized in that: The calculation unit sets the first cutoff frequency to be at least 10 times higher when the signal value of the first light-receiving signal, which is the object of calculating the baseline value, increases by more than 20% relative to the signal value at the immediately previous moment in the time waveform of the first light-receiving signal than when the signal value of the first light-receiving signal, which is the object of calculating the baseline value, decreases by more than 20% relative to the immediately previous signal value.

8. The breath sensor according to claim 6, characterized in that: The first cut-off frequency is below 3 Hz.

9. The breath sensor according to any one of claims 1 to 8, characterized in that: further comprising a second light receiving unit that receives the light that has not passed through the path through which the exhaled breath passes, among the light emitted by the light emitting unit, and outputs a second light receiving signal corresponding to a light receiving result, The calculation unit corrects the first light reception signal based on the signal value of the second light reception signal.

10. The breath sensor according to claim 9, characterized in that: The calculation unit generates the corrected first light receiving signal using a frequency component of the second light receiving signal that is lower than a set second cutoff frequency and a frequency component of the first light receiving signal that is lower than a set third cutoff frequency. The second cut-off frequency is lower than the third cut-off frequency.

11. The breath sensor according to claim 6, characterized in that: An optical filter is further provided. The optical filter is arranged on an optical path of the light between the light emitting unit and the first light receiving unit and is used to limit the wavelength of the light incident on the first light receiving unit.

12. A gas sensor for detecting a detection target gas, wherein the gas sensor is characterized by comprising: a light emitting unit configured to emit light toward a path through which the gas to be detected passes; a first light receiving unit that receives at least a portion of the light emitted by the light emitting unit and outputs a first light receiving signal corresponding to a light receiving result; and a computing unit for computing the first light receiving signal; in, The calculation unit calculates a base line of the waveform of the first light receiving signal based on a frequency component of the first light receiving signal lower than a set first cutoff frequency, and detects the detection target gas based on a signal obtained by removing the base line from the first light receiving signal.

13. A breath detection method for detecting breath produced by breathing, the breath detection method comprising the following steps: a light emitting step, wherein a light emitting unit irradiates light toward a path through which the exhaled air passes; a first light receiving step, wherein a first light receiving unit receives at least a portion of the light irradiated in the light emitting step; a first output step, wherein the first light receiving unit outputs a first light receiving signal corresponding to a light receiving result in the first light receiving step; as well as a calculation step, wherein a calculation unit calculates the first light receiving signal output in the first output step, The calculation step includes the following steps: a calculation step, wherein the calculation unit calculates a baseline of a waveform of the first light receiving signal based on a frequency component of the first light receiving signal that is lower than a set first cutoff frequency; and In the detection step, the calculation unit detects the exhaled breath based on a signal obtained by removing the baseline calculated in the calculation step from the first light reception signal.

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