JP2019162217A - Heart rate detection device, heart rate detection method, and program - Google Patents

Abstract

To provide a heart rate detection device and a heart rate detection method for managing a user's physical and mental state.SOLUTION: A heart rate detection device includes: a first detection unit 63 for detecting a plurality of first time points where a waveform that takes a maximum amplitude of a heartbeat signal is a first value; a second detection unit 64 for detecting a plurality of second time points where a waveform is a second value when an electric potential is lowered after a waveform of a positive potential is generated, a third detection unit 65 for detecting a plurality of detection points, which are second time points immediately after the first time points; and an arithmetic unit 66 for obtaining a cardiac cycle on the basis of an interval between the plurality of detection points. The cardiac cycle can be obtained on the basis of the detection point with less temporal error.SELECTED DRAWING: Figure 5

Description

  The present disclosure relates to a heartbeat detection device, a heartbeat detection method, and a program for obtaining a heartbeat period from a waveform based on a heartbeat.

  In a noise environment such as a construction site, a bone conduction microphone that acquires vocal cord vibration propagating through bone is used to remove the influence of noise and acquire a user's voice (for example, Patent Document 1).

  Heart rate information is often used to evaluate stress due to human physical and mental burden. The heart rate is assumed to reflect the activity of the autonomic nervous system.For example, the heart rate and the fluctuation of the pulse interval are calculated based on the heart rate information, and the temporal trend of the calculated heart rate and the fluctuation of the pulse interval is calculated. There is an apparatus for determining the degree of fatigue of a user based on the presence or absence of an instantaneous increase in heart rate (Patent Document 2).

JP-A-6-54387 JP 2002-65650 A

  There is a concern that work in a noisy environment at a construction site or the like places a high physical and mental burden on workers. Provided are a heartbeat detecting device and a heartbeat detecting method for managing the physical / mental state of an operator in such an environment.

  The heartbeat detection device according to the present disclosure inputs a heartbeat signal that is a waveform change based on a user's heartbeat, and when the heartbeat signal changes from a value smaller than a first value to the first value or more, or the heartbeat A first detection unit that detects a plurality of first time points that are any one of the time points when the signal changes from a value greater than the first value to the first value or less; and A second detection unit that detects a plurality of second time points that change from a value that is greater than a second value that is less than the value to a value that is less than or equal to the second value, and a detection that is the second time point immediately after the first time point A third detection unit that detects a plurality of points; and a calculation unit that obtains a cycle of the heartbeat based on an interval between the plurality of detection points.

  In the heart rate detection method according to the present disclosure, a heart rate signal that is a waveform change based on a user's heart rate is input, and the time point when the heart rate signal changes from a value smaller than a first value to the first value or more, or the heart rate A first detection step of detecting a first time point that is one of time points when the signal changes from a value greater than the first value to the first value or less; and the heartbeat signal is the first value A second detection step of detecting a second time point that changes from a value that is greater than a smaller second value to less than or equal to the second value; and a detection point that is the second time point immediately after the first time point. A third detection step to detect, and an operation for repeatedly detecting the third detection step from the first detection step to detect a plurality of the detection points and obtaining a cycle of the heartbeat based on an interval between the plurality of detection points Steps.

  The heartbeat detection device or the like according to the present disclosure can estimate the user's physical / mental state based on a waveform based on the heartbeat.

FIG. 1 is a perspective view showing a heartbeat detecting device in the first embodiment. FIG. 2 is a schematic diagram illustrating a control configuration of the heartbeat detecting device according to the first embodiment. FIG. 3 is a perspective view showing how the bone conduction headset according to the first embodiment is used. FIG. 4 is a cross-sectional perspective view of the bone conduction microphone according to the first exemplary embodiment. FIG. 5 is a block diagram showing details of the control configuration in the first embodiment. FIG. 6 is a block diagram showing details of another example of the control configuration in the first embodiment. FIG. 7 is a block diagram illustrating details of a control configuration in the second modification of the first embodiment. FIG. 8 is a block diagram showing details of the control configuration in the third modification of the first embodiment. FIG. 9 is a schematic diagram showing a control configuration in the heartbeat detecting device 1A of the second embodiment. FIG. 10 is a block diagram showing details of the control configuration in the second embodiment. FIG. 11 is a block diagram illustrating details of another control configuration according to the second embodiment. FIG. 12 is a block diagram illustrating a configuration of the calculation unit according to the third embodiment. FIG. 13 is a schematic diagram illustrating a waveform output by the calculation unit according to the third embodiment. FIG. 14 is a schematic diagram illustrating a waveform output by the calculation unit according to the first modification of the third embodiment. FIG. 15 is a block diagram illustrating a configuration of the calculation unit in the second modification of the third embodiment. FIG. 16 is a schematic diagram illustrating a waveform output by the calculation unit according to the second modification of the third embodiment.

  The heartbeat detection device of the present disclosure is used in a noise environment such as a factory site, and acquires a displacement of the user's body surface. Furthermore, the heartbeat detection device extracts voice information and heartbeat information propagating through the body, which are included in the acquired displacement of the body surface. The voice information is information representing a waveform change based on the utterance. The heartbeat information is information representing a waveform change based on the heartbeat.

  Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and repeated descriptions for substantially the same configuration may be omitted. This is to avoid the following description from becoming unnecessarily redundant and to facilitate understanding by those skilled in the art. In addition, in order for those skilled in the art to provide a thorough understanding of the present disclosure, the accompanying drawings and the following description are provided, and are not intended to limit the claimed subject matter.

(Embodiment 1)
The heartbeat detection device 1 in the present embodiment has a bone conduction microphone 3 and extracts voice information and heartbeat information included in the displacement of the body surface of the user U acquired by the bone conduction microphone 3.

[1-1. Overall configuration of heart rate detection device]
FIG. 1 is a perspective view showing a heartbeat detecting device 1 in the first embodiment. FIG. 2 is a schematic diagram illustrating a control configuration of the heartbeat detecting device 1 according to the first embodiment. FIG. 3 is a diagram illustrating a usage mode of the bone conduction headset 10 according to the first embodiment.

  As shown in FIGS. 1 and 2, the heartbeat detection device 1 includes a bone conduction headset 10 and a transceiver 2. The bone conduction headset 10 includes a bone conduction microphone 3, a speaker 4, and a control unit 5. The transceiver 2 has a communication unit 21.

  The bone conduction microphone 3 is attached to the body surface of the user U and acquires the displacement of the body surface of the user U. The bone conduction microphone 3 is a microphone made mainly for the purpose of acquiring audio information that propagates through bone. Therefore, it is suitable that the bone conduction microphone 3 is mounted on the body surface above the bone (a hard portion having bones such as the jawbone and cheekbone immediately below the body surface). However, it is considered that heart rate information mainly propagates through soft tissues such as muscles, blood vessels, and fats. When the bone conduction microphone 3 is mounted on the bone, the acquisition level of the heart rate information becomes small, and it is difficult to acquire the heart rate information at an extractable level. Therefore, when acquiring both voice information and heart rate information as in the present embodiment, as shown in FIG. 3, the bone conduction microphone 3 is placed on the soft tissue (the soft tissue between the body surface and the bone is thick and soft). Part), in particular, at least a part of the bone conduction microphone 3 is preferably mounted on the body surface in a range that is on the carotid artery of the user U. Here, “above” on bone, soft tissue, carotid artery, etc. is the body surface side in the thickness direction (Z direction) of the body of the user U. The acquisition level of audio information is smaller on soft tissue than on bone. However, the voice information is less position dependent than the heart rate information. Therefore, even when the bone conduction microphone 3 is attached to the body surface on the carotid artery, it can acquire audible audio information. Thereby, the user U can acquire audio | voice information and heart rate information only by mounting | wearing one sensor.

  As shown in FIG. 3, the bone conduction microphone 3 is attached to the mounting tool 12 using a fastener 34. The wearing tool 12 causes the acquisition unit 30 of the bone conduction microphone 3 to pressurize the body surface of the user U. Thereby, the possibility that the wearing state of the bone conduction microphone 3 changes during use is reduced, and the signal level of the acquired signal is stabilized. It is desirable for the wearing tool 12 to press the body surface of the user U to the acquisition unit 30 of the bone conduction microphone 3 with a pressure of 200 to 500 weight grams. When the pressureable strength is small, contact between the acquisition unit 30 and the user U's body surface is not sufficiently performed, and it is difficult to acquire necessary information. On the other hand, if the strength to pressurize is large, the heart rate information and the SN ratio of noise are deteriorated, so that it is difficult to obtain heart rate information. Moreover, when the pressure to be applied is high, there is a possibility that the user U may feel uncomfortable. Since the optimum pressure strength varies among individuals, it is desirable that the optimum pressure strength is determined by appropriately adjusting in the range of 200 to 500 weight grams.

  In the present embodiment, the attachment device 12 uses a chin strap shape to attach the bone conduction microphone 3 to the body surface of the user U's carotid artery. It is optional, such as stopping at.

  The speaker 4 is, for example, a bone conduction speaker. The speaker 4 is held by a holder 11 as shown in FIG. The speaker 4 is connected to the control unit 5 wirelessly or by wire. The control unit 5 is, for example, a central processing unit (CPU), a random access memory (RAM), and a read only memory (ROM). The control unit 5 may be a field-programmable gate array (FPGA), an application specific integrated circuit (ASIC), a microprocessor, an analog circuit, or the like.

  As shown in FIG. 2, the communication unit 21 is connected to the control unit 5 of the bone conduction headset 10 wirelessly or by wire. The communication unit 21 communicates with an external device. Specifically, the communication unit 21 inputs a signal output from the bone conduction microphone 3 via the control unit 5 and transmits the signal to an external device. On the other hand, the communication unit 21 receives a signal transmitted from an external device and outputs the signal to the speaker 4 via the control unit 5.

  The external device with which the communication unit 21 communicates is a call device or an information processing device of a partner with whom a call is made. The information processing device is, for example, a heartbeat detection device 1B described later, and is a personal computer that performs processing and monitoring of heartbeat information. The transceiver 2 is used by being attached to a part of clothes, for example. The heartbeat detection device 1 may not include the transceiver 2 and the bone conduction headset 10 may include the communication unit 21.

[1-2. Configuration of bone conduction microphone]
Next, a detailed configuration of the bone conduction microphone 3 will be described. FIG. 4 is a cross-sectional perspective view of the bone conduction microphone according to the first exemplary embodiment.

  As shown in FIG. 4, the bone conduction microphone 3 includes an acquisition unit 30 and a housing 33. The acquisition unit 30 includes a contact member 31 that contacts the user U and a displacement sensor 32 that is supported by the contact member 31.

  The contact member 31 is a member that is brought into contact with the body surface of the user U, acquires the displacement of the body surface of the user U, and transmits the acquired displacement to the displacement sensor 32. The contact member 31 is an elastic body that is softer than the housing 33 and is formed of a resin material such as silicon rubber. The term “soft” includes both the use of a soft material and the fact that it is structurally soft (for example, it is easily formed by being thinly formed or wavyly deformed). The contact member 31 is preferably made of a material that is comfortable to touch.

  The displacement sensor 32 is a detection element that detects a displacement in a predetermined direction (Z direction, that is, the thickness direction of the body) among the displacements of the body surface acquired through the contact member 31. The displacement sensor 32 converts the detected displacement of the body surface in the Z direction into an electrical signal (first signal) and inputs the electrical signal to the control unit 5 of the bone conduction headset 10. The displacement sensor 32 is attached to the inner wall of the contact member 31 so as to be able to bend in the Z direction and perform thickness vibration. Since the displacement sensor 32 is supported by the housing 33 via the contact member 31 that is an elastic body softer than the housing 33, vibration noise transmitted from the outside to the housing 33 and vibration noise generated in the housing 33. Becomes difficult to enter the displacement sensor 32. For this reason, the bone conduction microphone 3 can easily acquire voice information and heartbeat information propagating through the body.

  In this embodiment, the displacement sensor 32 is a plate-like piezoelectric element that performs thickness vibration. The displacement sensor 32 may be a capacitor or the like that detects the displacement of the body surface by a change in the interelectrode capacitance of the two electrodes. However, when the heart rate information when the user U speaks is acquired by the piezoelectric element, the heart rate information can be acquired at a higher level of the SN ratio between the heart rate information and the noise than when acquired by the capacitor. Therefore, the piezoelectric element easily obtains a signal that can simultaneously extract heart rate information and voice information.

  The housing 33 supports the acquisition unit 30.

[1-3. Extraction of voice information and heart rate information]
FIG. 5 is a block diagram showing a control configuration in the first embodiment.

  First, the displacement sensor 32 of the bone conduction microphone 3 converts the displacement of the user U's body surface in the Z direction into an analog signal S1.

  The control unit 5 detects voice information and heartbeat information included in the signal S1. As illustrated in FIG. 5, the control unit 5 includes an adjustment unit 51, an amplification unit 52, an extraction unit 53, an A / D conversion unit 54, and a calculation unit 56. First, audio information will be described.

  The amplifying unit 52a of the amplifying unit 52 outputs a signal S2 obtained by amplifying the signal S1. The amplifying unit 52a determines an amplification factor based on the signal level of the audio information, and performs amplification at a constant amplification factor.

  The audio filter 53a (first extraction unit) of the extraction unit 53 extracts a frequency component (first frequency component) based on the audio information included in the signal S2. The voice is mainly a frequency component larger than 100 Hz, and the heartbeat information is mainly a frequency component smaller than 10 Hz. Therefore, in the present embodiment, the high-pass filter (HPF) that removes the frequency band of 100 Hz or less is used as the audio filter 53a. The control unit 5 does not have to have the audio filter 53a. However, when the bone conduction microphone 3 is mounted on the body surface on the carotid artery, the heart rate information is superimposed on the audio information. It is preferable to provide the filter 53a.

  The A / D converter 54a of the A / D converter 54 converts the analog signal S3 into a digital data signal S4.

  The communication unit 21 of the transceiver 2 transmits a signal S4 (voice information) output from the control unit 5 to an external device. The external device is, for example, a call device of a partner who performs a call.

  Next, heart rate information will be described.

  The adjustment unit 51 receives the signal S1, removes the DC offset of the signal S1, and outputs a signal S5 whose output position is adjusted. The DC offset is a difference amount between the DC component of the input signal S1 and the zero reference value of the output of the A / D converter 54b. The zero reference value is normally the center value in the range of the input value of the A / D converter 54b, but is not limited to this, and the zero reference value is the value of the waveform of the signal S7 input to the A / D converter 54b. It is preferable to set within a range to avoid saturation. The adjustment unit 51 eliminates the influence of individual differences in the bone conduction microphone 3 to be used, the surrounding environment, and the like. In addition, heartbeat information with a low signal level is easily extracted.

  The amplifying unit 52b of the amplifying unit 52 outputs a signal S6 obtained by amplifying the signal S5. The amplifying unit 52b determines an amplification factor based on the signal level of the heartbeat information, and performs amplification at a constant amplification factor.

  The heartbeat filter 53b (second extraction unit) of the extraction unit 53 extracts a frequency component (second frequency component) based on the heartbeat information included in the signal S6, and outputs a signal S7. In the present embodiment, the heart rate filter 53b is a low pass filter (LPF) that removes a frequency band of 10 Hz or more.

  Note that the audio filter 53a and the heart rate filter 53b described above may use a band pass filter (BPF) that passes a predetermined band.

  The A / D converter 54b of the A / D converter 54 converts the analog signal S7 into a digital data signal S8.

  The calculation unit 56 receives the signal S8 and performs an analysis process of heartbeat information. The calculation unit 56 obtains the heartbeat cycle of the user U. The heartbeat period is used, for example, for obtaining a heart rate and heart rate fluctuation, and is useful for knowing the stress state of the user U. An example of the calculation unit 56 will be described in detail in Embodiment 3.

  The communication unit 21 of the transceiver 2 transmits the output of the calculation unit 56 (for example, data of heartbeat period, heart rate, and heart rate variability) to an external device. The external device is an information processing apparatus such as a personal computer, for example. The external device performs, for example, display of transmitted data and further analysis. Note that the communication unit 21 may transmit the heartbeat information extracted by the heartbeat filter 53b to an external device. In that case, analysis of the heart rate information received by the external device may be performed.

  As illustrated in FIG. 6, the extraction unit 53 may include a variable filter 53c. The variable filter 53c extracts voice information and heart rate information by changing the frequency band to be removed.

[1-4. Modification 1]
In the first modification of the first embodiment, the bone conduction microphone 3 includes an amplification unit 52a, an audio filter 53a, and an A / D conversion unit 54a. Similar to the first embodiment, the displacement sensor 32 of the bone conduction microphone 3 converts the displacement of the body surface in the thickness direction into a signal S1 and outputs the signal S1. The amplifier 52a outputs a signal S2 obtained by amplifying the signal S1. The audio filter 53a extracts a frequency component based on the audio information swelled in the signal S2, and outputs a signal S3. The A / D converter 54a converts an analog signal into a digital signal and outputs a signal S4. The bone conduction microphone 3 transmits a signal S4 which is digital data to an external device via the communication unit 21. Further, the signal S1 is output to the control unit 5. The control unit 5 includes an amplification unit 52b, a heart rate filter 53b, and an A / D conversion unit 54b, and extracts heart rate information based on the signal S1.

[1-5. Modification 2]
FIG. 7 is a block diagram illustrating details of a control configuration in the second modification of the first embodiment.

  The heartbeat detection device 1 according to Modification 2 includes a determination unit 57 that determines whether or not audio information is included in the signal S <b> 1 acquired by the displacement sensor 32. As illustrated in FIG. 7, the control unit 5 outputs the audio information to the communication unit 21 when the audio information is included, and outputs the signal S8 to the calculation unit 56 when the audio information is not included. Thereby, since the calculation part 56 calculates heart rate information based on the signal which does not contain audio | voice information, it becomes easy to extract heart rate information accurately.

  The determination unit 57 may perform the determination in accordance with the signal level of the signal S1, but if the determination unit 57 is configured by an analog circuit, the signal level has an error due to the influence of deterioration of the circuit elements, temperature characteristics, and the like. May occur. Therefore, in the present embodiment, the determination unit 57 is a signal output from the A / D conversion unit 54 (signal S4 when audio information is extracted and signal S8 when heartbeat information is extracted). Judgment is made according to the level. Audio information has a higher signal level than heart rate information. Therefore, when audio information is included, the signal level is higher than when audio information is not included. Therefore, when the signal level of the signal output from the A / D conversion unit 54 is equal to or higher than the predetermined value, the determination unit 57 determines that the audio information is included in the signal S1, and the A / D conversion unit 54 outputs the signal. When the signal level of the signal is less than the predetermined value, it is determined that the audio information is not included in the signal S1. The predetermined value may be determined for each of the voice information and the heart rate information.

  Note that the determination unit 57 performs the determination according to the signal level of the signal extracted by the extraction unit 53 (the signal S3 when audio information is extracted and the signal S7 when heartbeat information is extracted). However, due to the configuration of the analog circuit, an error may occur in the signal level.

  Note that the bone conduction microphone 3 may include the determination unit 57. For example, the determination unit 57 may determine whether or not sound information is included based on the pressure applied to the displacement sensor 32 instead of the signal level.

  The A / D conversion unit 54 includes an A / D conversion unit 54c, and the A / D conversion unit 54c converts either the signal S3 or the signal S7 into a digital signal based on the determination by the determination unit 57. It may be converted. In this way, by sharing the A / D conversion unit 54 for voice information and heart rate information, the number of A / D converters necessary for the control unit 5 can be reduced. Thereby, the cost of the control unit 5 can be reduced. Alternatively, other functions can be added to the control unit 5. When the A / D conversion unit 54c receives the signal S3, the A / D conversion unit 54c outputs the signal S3 to the communication unit 21. When the A / D conversion unit 54c receives the signal S7, the A / D conversion unit 54c outputs the signal S7 to the communication unit 21 via the calculation unit 56.

[1-6. Modification 3]
FIG. 8 is a block diagram showing details of the control configuration in the third modification of the first embodiment. The third modification of the first embodiment shows another control configuration when the voice information and the heartbeat information are extracted using the determination unit 57. In the present embodiment, the determination unit 57 is configured by a digital circuit. The control unit 5 of the present embodiment is different from the second modification of the first embodiment in the amplification unit, and includes an amplification unit 52c, an amplification unit 52d, and an amplification unit 52e.

  First, the adjustment unit 51 receives the analog signal S1 output from the displacement sensor 32, removes the DC offset of the signal S1, and outputs a signal S12 whose output position is adjusted. The amplifying unit 52c outputs a signal S13 obtained by amplifying the signal S12. The amplification factor of the amplifying unit 52c is a value between the magnification for extracting voice information and the magnification for extracting heartbeat information, for example, an average value.

  The A / D converter 54 converts the analog signal S13 into a digital data signal S14.

  Based on the determination by the determination unit 57, either voice information or heartbeat information is extracted. The determination of the determination unit 57 is performed based on the signal S14 output from the A / D conversion unit 54. The determination by the determination unit 57 may be performed based on the signal S16 or S18 extracted by the extraction unit 53.

  When extracting the audio information, the amplifying unit 52d amplifies the signal S14 and outputs the signal S15 so as to have an appropriate size for extracting the audio information. When extracting the audio information, the audio filter 53a extracts the audio information from the signal S15 and outputs the signal S16 to the communication unit 21.

  When extracting the heart rate information, the amplifying unit 52e amplifies the signal S14 and outputs the signal S17 so as to have an appropriate size for extracting the heart rate information. The heartbeat filter 53b extracts heartbeat information from the signal S17 and outputs the signal S18 to the communication unit 21 via the calculation unit 56.

[1-7. Effect]
In the present embodiment, the heartbeat detection device 1 includes a bone conduction microphone 3 that converts a displacement in the thickness direction of the body surface of the user U into a signal S1, and a first frequency component based on audio information included in the signal S1. And an extraction unit for extracting a second frequency component based on the user's heartbeat information included in the signal S1. Thereby, the heartbeat detecting device 1 extracts both the voice information and the heartbeat information from the signal S1 output from the bone conduction microphone 3. The user U does not need to wear a plurality of sensors, and the burden on the user U is small. In addition, the body / psychological state of the user U can be estimated based on the heartbeat information.

  Moreover, in this Embodiment, the bone conduction microphone 3 is provided with the displacement sensor 32 which converts the displacement of the body surface of the user U into signal S1. The displacement sensor 32 is preferably a piezoelectric element. Thereby, it is easy to acquire a signal from which both heartbeat information and voice information can be extracted. Therefore, heartbeat information is easily extracted from a signal in which heartbeat information and audio information are superimposed.

  In the present embodiment, the bone conduction microphone 3 includes a contact member 31 that acquires the displacement of the body surface of the user U and transmits the displacement to the displacement sensor 32. The contact member 31 is an elastic body that is softer than the housing 33. Thereby, since the displacement sensor 32 is supported by the housing 33 via the soft contact member 31, vibration noise transmitted from the outside to the housing 33 and vibration noise generated in the housing 33 are difficult to enter the displacement sensor 32. Become. Therefore, it becomes easy for the bone conduction microphone 3 to acquire voice information and heart rate information propagating through the body.

  Moreover, in this Embodiment, the extraction part 53 can extract the frequency component (2nd frequency component) based on the heart rate information superimposed on the frequency component (1st frequency component) based on audio | voice information. Thereby, heart rate information can be extracted regardless of the presence or absence of speech.

  In the present embodiment, it is desirable that the bone conduction microphone 3 is attached to the body surface in a range where at least a part of the bone conduction microphone 3 is on the carotid artery of the user U. This makes it easier for the bone conduction microphone to acquire heartbeat information that is more position-dependent than audio information. Therefore, voice information and heart rate information can be detected for the user U only by wearing one sensor.

  Moreover, in this Embodiment, the wearing tool 12 of the heartbeat detection apparatus 1 pressurizes the body surface of the predetermined part of the user U to the bone conduction microphone 3 (acquisition part 30). Thereby, the possibility that the wearing state of the bone conduction microphone 3 changes during use is reduced, and the signal level of the acquired signal is stabilized.

  Moreover, in this Embodiment, the bone conduction microphone 3 pressurizes the said predetermined site | part with the force of 200 weight grams or more. Thereby, the bone conduction microphone 3 and the body surface of the user U are brought into contact with each other with sufficient force, and extractable voice information and heart rate information can be acquired.

  Moreover, in this Embodiment, the bone conduction microphone 3 pressurizes the said predetermined site | part with the force of 500 weight grams or less. Thereby, the SN ratio of the noise including the heartbeat information and the voice information is improved, and the extractable heartbeat information can be acquired. Moreover, the user U's discomfort is reduced.

  In the second modification of the present embodiment, the heartbeat detection device 1 includes a determination unit 57 that determines whether the S1 signal acquired by the displacement sensor 32 includes audio information. Based on the determination by the determination unit 57, The extraction unit 53 extracts either voice information or heartbeat information. Thereby, since heart rate information is extracted based on a signal that does not include audio information, it becomes easier to extract heart rate information.

  Moreover, in this Embodiment, the heart rate detection apparatus 1 is provided with the adjustment part which adjusts the output position of signal S1. This eliminates the influence of individual differences of the bone conduction microphone 3 to be used, the surrounding environment, and the like. Furthermore, it is easy to extract heartbeat information with a low signal level.

  Moreover, in this Embodiment, the control part 5 of the heartbeat detection apparatus 1 is provided with the calculation part 56 which calculates | requires the heartbeat period of the user U based on the heartbeat information which the extraction part 53 extracted. Thereby, the stress state of the user U can be known.

(Embodiment 2)
In the heartbeat detection device 1A according to the second embodiment, the displacement sensor 32 of the bone conduction microphone 3 acquires the displacement of the body surface of the user U and converts it into a signal S1. The communication unit 21 transmits the signal S1 to the heartbeat detection device 1B. The heartbeat detecting device 1B extracts voice information and heartbeat information included in the signal S1. Note that the description of the same configuration as that of Embodiment 1 is omitted.

[2-1. Configuration of Heartbeat Detection Device 1A]
FIG. 9 is a schematic diagram showing a control configuration in the heartbeat detecting device 1A of the second embodiment. FIG. 10 is a block diagram showing details of the control configuration in the second embodiment.

  The heartbeat detecting device 1A according to the second embodiment includes a bone conduction headset 10A and a transceiver 2 as shown in FIG.

  The displacement sensor 32 of the bone conduction microphone 3 converts the detected displacement of the body surface in the Z direction into a signal S1. The bone conduction microphone 3 outputs the signal S1 to the transceiver 2 via the control unit 5A. The communication unit 21 of the transceiver 2 transmits the signal S1 to the heartbeat detection device 1B.

[2-2. Configuration of Heartbeat Detection Device 1B]
The heartbeat detection device 1B is a computer including, for example, a central processing unit (CPU), a random access memory (RAM), a read only memory (ROM), and the like. The heartbeat detection device 1B may be configured by a field-programmable gate array (FPGA), an application specific integrated circuit (ASIC), a microprocessor, and an analog circuit.

  The heartbeat detecting device 1B includes a communication unit 21B, a control unit 5B, an audio output unit 55B, a display unit 58B, and a notification unit 59B.

  As shown in FIG. 10, the communication unit 21B receives the signal S1 from the communication unit 21 of the heartbeat detecting device 1A. The control unit 5B extracts voice information and heart rate information from the signal S1 received by the communication unit 21B. The control unit 5B includes an adjustment unit 51, an amplification unit 52, an extraction unit 53, an A / D conversion unit 54, a setting unit 55, and a calculation unit 56. Extraction of voice information and heart rate information performed by the control unit 5B is the same as that of the control unit 5 of the first embodiment, and thus description thereof is omitted.

  The audio output unit 55B outputs a signal S4 and makes a call with the user U, for example.

  The display unit 58B displays the heart rate information extracted by the extraction unit 53 and the output of the calculation unit 56 (for example, heart rate cycle, heart rate, heart rate fluctuation data). The display unit 58B may display the signal S8. Thereby, the state of the user U can be monitored.

  The heartbeat detecting device 1B may include a notification unit 59B that notifies when there is an abnormal value in the data representing the analysis result. The notification unit 59B outputs a warning sound, for example.

  Note that the communication unit 21B may transmit the signal S8 representing the heartbeat information and the output of the calculation unit 56 to an external device. The external device performs, for example, display of transmitted data and further analysis.

  As shown in FIG. 11, the heartbeat detection device 1 </ b> A includes an amplification unit 52, an extraction unit 53, and an A / D conversion unit 54, extracts voice information and heartbeat information, and passes through the communication unit 21. May be transmitted to an external device. The heartbeat detection device 1B receives the signal S8, and the calculation unit 56 performs analysis processing of heartbeat information based on the signal S8. The heartbeat detecting device 1B may receive the signal S4 transmitted from the heartbeat detecting device 1A and output the signal S4 by the sound output unit 55B.

[2-3. Effect]
In the present embodiment, the heartbeat detection device 1B includes a communication unit 21B that receives a signal S4 including voice information and heartbeat information, and an extraction unit 53 that extracts the voice information and heartbeat information included in the signal S4. Thereby, voice information and heart rate information can be extracted from a signal including voice information and heart rate information. The state of the user U can be estimated based on the extracted heartbeat information.

(Embodiment 3)
In the third embodiment, an example of the calculation unit 56 of the heartbeat detecting device in the first and second embodiments will be described in detail.

[3-1. Calculation of heartbeat cycle]
FIG. 12 is a block diagram showing a configuration of the calculation unit 56 in the present embodiment. FIG. 13 is a schematic diagram illustrating a waveform output by the calculation unit 56 in the present embodiment.

  The calculation unit 56 obtains the heartbeat cycle of the user U based on the signal S8. The signal S8 is a heartbeat signal (a signal based on heartbeat information). The heartbeat signal acquired by the bone conduction microphone 3 is an approximately periodic waveform reflecting the contraction and relaxation of the ventricle and the atrium. Of the heartbeat signal generated in one heartbeat, the waveform having a peak in the positive potential is set to a wave, b wave, and c wave in order of elapsed time as shown in FIG. The b-wave and c-wave are usually smaller in amplitude than the a-wave.

  As shown in FIG. 12, the calculation unit 56 includes a BPF 61, an amplification unit 62, a first detection unit 63, a second detection unit 64, a third detection unit 65, and a calculation unit 66.

  The BPF 61 is a band pass filter (BPF) that extracts a predetermined frequency band included in the signal S8. The LPF of the BPF 61 removes high frequency component noise. The HPF of the BPF 61 matches the DC component of the signal S8 with the zero reference value. In the present embodiment, the BPF 61 uses a BPF that removes a frequency band from 1 Hz to 10 Hz.

  The amplifying unit 62 appropriately changes the amplification factor so that the maximum amplitude (a wave amplitude) of the amplified signal becomes a predetermined value, and amplifies the signal S9 to the signal S10. The amplifying unit 62 switches the amplification factor at a period (hereinafter referred to as a switching period) determined based on the heartbeat period. A predetermined fixed value (for example, 1 second) may be used as the switching period. In addition, since there are individual differences in the heartbeat period, the switching period may be set as appropriate based on the heartbeat period of the user U.

  The first detection unit 63 detects a plurality of a waves included in the signal S10. As shown in FIG. 13A, the first detection unit 63 detects a plurality of first time points when the signal S10 changes from a value smaller than the first value to a value equal to or higher than the first value. In the present embodiment, even if a waveform other than the a wave is erroneously detected as the first value, it is not used for calculation of the period, and therefore the first value may be equal to or less than the maximum value of the signal S10. However, the first value is preferably less than the amplitude of the a wave and larger than the amplitudes of the b wave and the c wave, for example, 50% or more of the amplitude of the a wave (maximum value of the heartbeat signal).

  The first time point is not used as the time point for obtaining the period, and is intended to detect the a wave. Therefore, since an error in time is allowed, detection is performed with a small amount of calculation. In the present embodiment, the first value is 100% of the amplitude of the a wave, which is a predetermined value when determining the amplification factor of the amplifying unit 62. Since the amplification unit 62 feeds back the amplification factor determined based on the output signal S10 and amplifies the signal S9, the a-wave amplitude may be smaller than a predetermined value. Therefore, the first value may be less than 100% of the predetermined value.

  The first time point may be a time point when the signal S10 changes from a value greater than the first value to a value less than or equal to the first value.

  The second detection unit 64 detects a plurality of points that decrease after the signal S10 increases in the positive power direction and have a second value. As shown in FIG. 13B, the second detection unit 64 detects a plurality of second time points when the signal S10 changes from a value greater than the second value to a value less than or equal to the second value. The second value is smaller than the first value.

  Since the second time point is used as a detection point when the period is obtained, it is required that the time error is small. The heartbeat signal has the largest inclination near the center of vibration. Since the adjustment unit 51 performs adjustment so that the output position of the DC component of the heartbeat signal matches the zero reference value, the second value is preferably set to the zero reference value.

  The third detection unit 65 detects a plurality of detection points that are second time points immediately after the first time point. As shown in FIG. 13C, the counter 65a measures the elapsed time with the first time point as the start point of time passage. The determination unit 65b determines whether the elapsed time from the start point is less than the threshold based on the counter 65a at the second time point immediately after the start point.

  Based on the determination, the determination unit 65b starts and stops outputting the detection value at the second time point as shown in FIG. The start point of output of the detection value is used for calculation of the heartbeat cycle. As shown in FIG. 13D, when the elapsed time is less than the threshold value at the second time point immediately after the start point, the determination unit 65b determines that the second time point is a detection point and The output of the detected value “1” shown is started. The determination unit 65b stops outputting the detection value at the next second time point (second time point not immediately after the start point). When the detection value output is stopped, the non-detection value is set to “0”. In addition, when the elapsed time is equal to or greater than the threshold at the second time point immediately after the start point, the determination unit 65b determines that the second time point is not the detection point and does not start outputting the detection value. This reduces the possibility of detecting the detection point by mistake.

  The computing unit 66 obtains the heartbeat period based on the intervals between the plurality of detection points detected by the third detection unit 65.

  In FIG. 13D, the determination unit 65b sets the detected value to “1” and the non-detected value to “0”, but the values are not limited to these. Any value may be used as long as the detected value and the non-detected value are different. In addition, the determination unit 65b may output a plurality of non-detection values, for example, by outputting different values at the second time immediately after the first time point and at the second time point not immediately after the first time point. .

  In the present embodiment, output of the detection value is started at the detection point, and output of the detection value is stopped at the next second time point, but the detection value is output at the detection point, and after a predetermined time, For example, detection value output may be stopped after 0.1 second.

  In addition, the calculation part 56 in this Embodiment may obtain | require the heart beat period similarly based on signal S18 which the heart rate filter 53b in FIG. 8 outputs.

  Note that the calculation unit 56 in the present embodiment may obtain a heartbeat cycle based on a heartbeat signal acquired by a device other than the bone conduction microphone. This embodiment is particularly useful for obtaining a highly accurate heartbeat cycle based on a waveform whose signal waveform is gentler than that of an electrocardiogram or the like, such as an acceleration pulse wave.

[3-2. Modification 1]
FIG. 14 is a schematic diagram illustrating a waveform output by the calculation unit 56 in Modification 1 of the present embodiment. The configuration of the calculation unit 56 is the same as that in FIG.

  Of the heartbeat signal generated in one heartbeat, the waveform in which a peak occurs in the negative potential is d wave and e wave in order of elapsed time as shown in FIG. In many cases, a heartbeat signal generated in one heartbeat has a waveform that has a maximum amplitude with a d-wave and attenuates along the elapsed time.

  The calculation unit 56 obtains a heartbeat cycle based on a waveform in which a peak occurs in the negative potential. The calculation unit 56 includes a BPF 61, an amplification unit 62, a first detection unit 63, a second detection unit 64, a third detection unit 65, and a calculation unit 66. Since the BPF 61 and the amplifying unit 62 have the same configuration as that of the third embodiment, description thereof is omitted.

  The first detection unit 63 detects the d wave included in the signal S10. As shown in FIG. 14A, the first detection unit 63 detects a plurality of third time points when the signal S10 changes from a value greater than the third value to a value equal to or less than the third value. The third value may be equal to or greater than the minimum value of the signal S10. However, it is preferable that the third value is not less than the amplitude of the d wave and smaller than the amplitude of the e wave, for example, 50% or less of the amplitude of the d wave (minimum value of the heartbeat signal).

  Note that the third time point may be a time point when the signal S10 changes from a value smaller than the third value to a third value or more.

  The second detection unit 64 detects a plurality of points where the potential rises after the waveform of the negative potential is generated and becomes the fourth value. As shown in FIG. 14B, the second detection unit 64 detects a plurality of fourth time points at which the signal S10 changes from a value smaller than the fourth value to a fourth value or more. The fourth value is larger than the third value. In the present embodiment, the fourth value is a zero reference value.

  The third detection unit 65 detects a plurality of detection points that are the fourth time point immediately after the third time point.

  As shown in FIG. 14C, the counter 65a measures the elapsed time with the third time point as the start point of time passage.

  The determination unit 65b determines whether the elapsed time from the start point is less than the threshold based on the counter 65a at the fourth time point immediately after the start point. Based on the determination, the determination unit 65b starts and stops outputting the detection value at the fourth time point as illustrated in FIG. About the start and stop of the output of the determination part 65b, since it is the same as the determination part 65b of Embodiment 3, description is abbreviate | omitted.

  The computing unit 66 obtains the heartbeat period based on the intervals between the plurality of detection points detected by the third detection unit 65.

  In addition, when the potential of the heartbeat signal is inverted, the calculation unit 56 can similarly determine the heartbeat period by using the a wave in FIG. 13 as the d wave in the first modification.

[3-3. Modification 2]
FIG. 15 is a block diagram illustrating a configuration of the calculation unit 56B in the second modification of the present embodiment. FIG. 16 is a schematic diagram illustrating a waveform output by the calculation unit 56B in Modification 2 of the present embodiment.

  The calculation unit 56B includes a BPF 61, an amplification unit 62, a first detection unit 63B, and a calculation unit 66B. Since the BPF 61 and the amplifying unit 62 have the same configuration as that of the third embodiment, description thereof is omitted.

  The first detection unit 63B detects the a wave included in the signal S10. As shown in FIG. 16, the first detection unit 63B detects a plurality of fifth time points at which the signal S10 changes from a value smaller than the fifth value to a fifth value or more. The fifth value is a value smaller than the amplitude of the a wave and larger than the amplitudes of the b wave and the c wave. In this embodiment, less than 90% of the amplitude of the a wave (maximum value of the heartbeat signal) is set as the fifth value. The fifth time point may be a time point when the signal S10 changes from a value greater than the fifth value to a value not greater than the fifth value.

  The waveform of the heartbeat signal acquired by the bone conduction microphone 3 has a smaller slope near the peak than the waveform acquired by the electrocardiogram, and an error may occur when the peak value is detected by setting the first value to a large value. There is. Therefore, the fifth value used as the detection point uses a portion where the inclination of the a wave is large, for example, less than 90% of the amplitude of the a wave.

  The fifth value may be a value smaller than the amplitude of the a wave and larger than the amplitudes of the b wave and the c wave, for example, 50% or more of the amplitude of the a wave. Thereby, the precision of a heartbeat period can be improved.

  The computing unit 66B obtains a heartbeat period based on the intervals between the plurality of first time points.

[3-4. Effect]
In the present embodiment, the heartbeat detection device 1 inputs the heartbeat signal of the user U, and when the heartbeat signal changes from a value smaller than the first value to a first value or more, or the heartbeat signal is the first A first detection unit 63 for detecting a plurality of first time points that are any one of the time points that change from a value greater than a value to a first value or less, and a second value whose heartbeat signal is smaller than the first value. A second detection unit 64 that detects a plurality of second time points that change from a large value to a second value or less, and a third detection unit that detects a plurality of detection points that are second time points immediately after the first time point 65, and a calculation unit 66 for obtaining a heartbeat period based on the intervals between the plurality of detection points. Thereby, the heartbeat detection apparatus 1 can obtain the heartbeat cycle based on the detection points with a small temporal error.

  Moreover, in this Embodiment, the 2nd value which the 2nd detection part 64 uses for the detection of a 2nd time is a zero reference value. As a result, the heartbeat signal has a larger slope near the second value, and the time error of the second value is reduced.

  In the present embodiment, the third detection unit 65 includes a counter 65a that measures an elapsed time from the first time point as a start point, and a second time point immediately after the start point when the elapsed time is less than a threshold value. A determination unit that determines that the second time point is a detection point, and determines that the second time point is not the detection point when the elapsed time at the second time point immediately after the start point is equal to or greater than the threshold value. This reduces the possibility of erroneously detecting a gentle waveform (for example, c-wave) that occurs later in the elapsed time as a detection point.

  In the present embodiment, the determination unit 65b starts outputting the detection value when the value of the elapsed time is less than the threshold at the second time point immediately after the measurement start point of the counter 65a. At a second time point not immediately after the first time point, output of the detection value is stopped. The computing unit 66 obtains a heartbeat period using the time when the determination unit 65b starts outputting the detection value as a detection point. Thereby, when the 1st detection part 63 detects b wave accidentally, possibility that the component of b wave will be mistakenly detected as a detection point is reduced.

  In the present embodiment, the heartbeat detection device 1 includes an adjustment unit 51 that adjusts the output position of the heartbeat signal. Thereby, the value with a large inclination of the heartbeat signal is in the vicinity of the zero reference value, and a temporal error when the constant value is set to the second value is reduced.

  In the present embodiment, the heartbeat detection device 1 includes an amplification unit 62 that amplifies the heartbeat signal so that the maximum amplitude of the heartbeat signal becomes a predetermined value. Thereby, the setting of the first value can be set on the basis of a predetermined value when determining the amplification factor of the amplifying unit 62, and the accuracy of detecting the first value of the a wave is increased.

  In the first modification of the present embodiment, the heartbeat detection device 1 inputs a heartbeat signal that is a waveform change based on the heartbeat of the user U, and the heartbeat signal is smaller than the third value to the third value or more. A first detection unit 63 for detecting a plurality of third time points, which is either a time point when the heartbeat signal changes to a third value or less, A second detector 64 for detecting a plurality of fourth time points at which the signal changes from a value less than the fourth value greater than the third value to a value greater than or equal to the fourth value; and the fourth detector immediately after the third time point. A third detection unit 65 that detects a plurality of detection points as time points, and a calculation unit 66 that obtains the cycle of the heartbeat based on an interval between the detection points. Thereby, the heartbeat cycle can be obtained based on a waveform in which a peak occurs in the minus of the heartbeat signal.

  In the second modification of the present embodiment, the heartbeat detection device 1 inputs a heartbeat signal that is a waveform change based on the heartbeat of the user U, and the fifth heartbeat signal is less than 90% of the maximum value of the heartbeat signal. Detect multiple fifth time points, either the time when the value changes from a value less than the value to the fifth value or more, or the time when the heart rate signal changes from a value greater than the fifth value to the first value or less A first detection unit 63B that performs the calculation, and a calculation unit 66B that obtains a cycle of the heartbeat based on a plurality of intervals between the fifth time points. Thereby, it is possible to simply and accurately obtain a heartbeat cycle.

  The present disclosure is applicable to a sound collection device that acquires sound information by contacting a human body. In addition, the present disclosure provides voice input when talking to a communication partner wearing a helmet, motorcycle helmet, headphones or intercom (intercommunication), etc. used at construction sites, construction sites, factories, and distribution warehouses. Applicable to output device.

DESCRIPTION OF SYMBOLS 1, 1A, 1B Heartbeat detection apparatus 2 Transceiver 3 Bone conduction microphone 4 Speaker 5, 5A, 5B Control part 10, 10A Bone conduction headset 11 Holder 12 Wearing tool 21, 21B Communication part 30 Acquisition part 31 Contact member 32 Displacement sensor 33 Housing 34 Fastener 51 Adjustment unit 52, 52a, 52b, 52c, 52d, 52e, 62 Amplification unit 53 Extraction unit 53a Audio filter (first extraction unit)
53b Heart rate filter (second extraction unit)
54, 54a, 54b, 54c A / D converter 55B Audio output unit 56, 56B Calculation unit 57, 65b Determination unit 58B Display unit 59B Notification unit 61 BPF
63, 63B First detection unit 64 Second detection unit 65 Third detection unit 65a Counter 66, 66B Calculation unit

Claims (14)

Input a heartbeat signal that is a waveform change based on the user's heartbeat,
Either when the heartbeat signal changes from a value less than a first value to the first value or more, or when the heartbeat signal changes from a value greater than the first value to the first value or less A first detector for detecting a plurality of first time points,
A second detector for detecting a plurality of second time points when the heartbeat signal changes from a value greater than a second value smaller than the first value to a value less than or equal to the second value;
A third detection unit that detects a plurality of detection points that are the second time points immediately after the first time point;
A calculation unit that obtains the cycle of the heartbeat based on the interval between the plurality of detection points,
Heart rate detection device. The first value is 50% or more of the maximum value of the heartbeat signal.
The heartbeat detecting device according to claim 1. The second value is a zero reference value;
The heartbeat detection device according to claim 1 or 2. The third detection unit includes:
A counter that measures elapsed time starting from the first time point;
If the elapsed time at the second time point immediately after the start point is less than a threshold, determine the second time point as the detection point;
A determination unit that determines that the second time point is not the detection point when the elapsed time at the second time point immediately after the start point is equal to or greater than the threshold;
The heartbeat detecting device according to any one of claims 1 to 3. The calculation unit sets the detection point as a point in time when the determination unit starts outputting a detection value,
The determination unit
When the elapsed time is less than the threshold at the second time point immediately after the start point, the detection value is output and the detection value is output at the second time point not immediately after the first time point. Stop
In the second time immediately after the start point, when the elapsed time is equal to or greater than a threshold value, the output of the detection value is not started.
The heartbeat detection device according to claim 4. A bone conduction microphone for converting displacement in the thickness direction of the user's body surface into a first signal;
An extraction unit for extracting the heartbeat signal included in the first signal;
The heartbeat detecting device according to any one of claims 1 to 5. An adjustment unit for adjusting the output position of the heartbeat signal;
The heartbeat detecting device according to any one of claims 1 to 6. An amplifying unit that amplifies the heartbeat signal so that the maximum value of the heartbeat signal becomes a predetermined value;
The heartbeat detecting device according to any one of claims 1 to 7. Input a heartbeat signal that is a waveform change based on the user's heartbeat,
Either when the heartbeat signal changes from a value less than a third value to the third value or more, or when the heartbeat signal changes from a value greater than the third value to the third value or less A first detector that detects a plurality of third time points,
A second detector for detecting a plurality of fourth time points when the heartbeat signal changes from a value less than a fourth value greater than the third value to a value greater than or equal to the fourth value;
A third detection unit for detecting a plurality of detection points that are the fourth time point immediately after the third time point;
A calculation unit that obtains the cycle of the heartbeat based on the interval between the plurality of detection points,
Heart rate detection device. Input a heartbeat signal that is a waveform change based on the user's heartbeat,
When the heartbeat signal changes from a value less than a fifth value less than 90% of the maximum value of the heartbeat signal to a value greater than or equal to the fifth value or from a value greater than the fifth value A first detection unit that detects a plurality of fifth time points that are any one of the time points that change below the first value;
A calculation unit for obtaining a cycle of the heartbeat based on the intervals of the plurality of fifth time points,
Heart rate detection device. A bone conduction microphone for converting displacement in the thickness direction of the user's body surface into a third signal;
An extraction unit for extracting the heartbeat signal included in the third signal;
The heartbeat detection device according to claim 10. Input a heartbeat signal that is a waveform change based on the user's heartbeat,
Either when the heartbeat signal changes from a value less than a first value to the first value or more, or when the heartbeat signal changes from a value greater than the first value to the first value or less A first detection step for detecting a first point in time,
A second detection step of detecting a second time point when the heartbeat signal changes from a value greater than a second value less than the first value to a value less than or equal to the second value;
A third detection step of detecting a detection point that is the second time point immediately after the first time point;
A step of repeatedly performing the third detection step from the first detection step to detect a plurality of the detection points, and obtaining a cycle of the heartbeat based on an interval between the plurality of detection points.
Heart rate detection method. The third detection step includes
Measure the elapsed time starting from the first time point,
If the elapsed time at the second time point immediately after the start point is less than a threshold, determine the second time point as the detection point;
A determination step of determining that the second time point is not the detection point when the elapsed time at the second time point immediately after the start point is equal to or greater than a threshold;
The heartbeat detection method according to claim 12.   A program for causing a computer to execute the heartbeat detection method according to claim 12 or 13.