Biometric information detection device

Abstract

To provide a biological information detection device capable of suppressing deterioration in biological information detection accuracy resulting from a movement in the surrounding of an object person.SOLUTION: A biological information detection device 1 includes a reception antenna 13 for receiving a radio wave radiated from a transmission antenna 12 and transmitted through an object person, and an information control unit 20. The information control unit 20 includes an input part 21 for acquiring a reception signal according to the radio wave received by the reception antenna 13 when the radio wave is radiated from the transmission antenna 12, and a processing part 24 for calculating biological information on the object person on the basis of the reception signal acquired by the input part 21. The processing part 24 specifies a signal component generated resulting from a movement in the surrounding of the object person as noise contained in the reception signal, and calculates biological information from the reception signal with the signal component removed.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a biological information detection device that detects biological information. [Background technology]

[0002] Conventionally, a heartbeat detection device capable of detecting the heartbeat of a subject in a non-contact and non-restraint manner is known (see, for example, Patent Document 1). This device transmits a radio frequency signal to a predetermined part of the subject, receives the radio frequency signal that has passed through the subject's body, and detects the subject's heartbeat based on the phase or amplitude of the received signal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-153783 A Summary of the Invention [Problem to be solved by the invention]

[0004] Meanwhile, the inventors have considered detecting a subject's biometric information, such as the heart rate, of an occupant seated in a vehicle seat by using the technology disclosed in Patent Document 1, etc.

[0005] However, it has been found that the received signal used to calculate the biometric information fluctuates when there is some movement around the subject. This is undesirable because it leads to a decrease in the detection accuracy of the biometric information. This problem is not limited to cases where the subject is a passenger seated in a vehicle seat, but can also occur when the subject is someone other than the passenger.

[0006] An object of the present disclosure is to provide a biological information detection device capable of suppressing a decrease in detection accuracy of biological information caused by movements around a subject. [Means for solving the problem]

[0007] The invention described in claim 1 is A biological information detection device for detecting biological information of a subject, a receiving antenna (13) that receives radio waves radiated from the transmitting antenna (12) and transmitted through the target person; a signal acquiring unit (21) that acquires a received signal corresponding to the radio wave received by the receiving antenna when the radio wave is radiated from the transmitting antenna; A calculation unit (24) that calculates biological information based on the received signal acquired by the signal acquisition unit, The calculation unit is Based on the output signal of the in-vehicle device (40, 50, 60), Signal components caused by movements around the subject are identified as noise contained in the received signal, and biometric information is calculated from the received signal after removing the signal components. It is as follows. The output signal of the in-vehicle device is a signal that is different from the received signal corresponding to the radio waves received by the receiving antenna. .

[0008] With this, signal components arising from movements around the subject are removed from the received signal as noise contained in the signal, and the biometric information is calculated from the signal, thereby suppressing a decrease in the detection accuracy of the biometric information caused by movements around the subject.

[0009] Note that the reference symbols in parentheses attached to each component indicate an example of the correspondence between the component and specific components described in the embodiments described below. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram of a biological information detection device according to a first embodiment. [Diagram 2] 5 is a flowchart showing a flow of processing executed by an information control unit of the biological information detecting device according to the first embodiment. [Diagram 3] 5 is a flowchart showing a flow of a noise removal process executed by an information control unit of the biological information detecting device according to the first embodiment. [Figure 4] FIG. 11 is an explanatory diagram for explaining a flow of processing of a received signal when the wipers are not in operation. [Diagram 5]FIG. 11 is an explanatory diagram for explaining frequency characteristics of a received signal when the wipers are not in operation. [Figure 6] FIG. 11 is an explanatory diagram for explaining a received signal when the wipers are in operation. [Figure 7] 6 is an explanatory diagram for explaining frequency characteristics of a received signal when the wipers are operating; FIG. [Figure 8] 5 is an explanatory diagram for explaining an example of processing of a received signal when a wiper is in operation; FIG. [Figure 9] 10 is an explanatory diagram for explaining another example of the processing of the received signal when the wipers are in operation; FIG. [Figure 10] 10 is a flowchart showing a flow of processes executed by an information control unit of a biological information detecting device according to a second embodiment. [Figure 11] 13 is a flowchart showing a flow of a noise removal process executed by an information control unit of a biological information detecting device according to a second embodiment. [Figure 12] 13 is a flowchart showing a flow of processes executed by an information control unit of a biological information detecting device according to a third embodiment. [Figure 13] 13 is a flowchart showing the flow of a noise removal process executed by an information control unit of a biological information detecting device according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, the same reference numerals are used for parts that are the same as or equivalent to those described in the preceding embodiments, and the description thereof may be omitted. In addition, in the embodiments, when only a part of the components is described, the components described in the preceding embodiments can be applied to the other parts of the components. In the following embodiments, each embodiment can be partially combined with each other, even if not specifically stated, as long as it does not cause any trouble in combination.

[0012] (First embodiment) The present embodiment will be described with reference to Fig. 1 to Fig. 9. In the present embodiment, an example will be described in which the heart rate of one occupant P seated in a seat S of a vehicle V is calculated as bioinformation using a bioinformation detection device 1 of the present disclosure.

[0013] The vehicle V is an autonomous vehicle equipped with an autonomous driving system. When the autonomous driving system is below a certain index level (for example, below NHTSA's index level 3), it operates under the supervision of the driver, and the driver is responsible for driving. On the other hand, it has been reported in many academic societies that the autonomous driving system reduces the psychological burden on the occupant P, including the driver, and reduces the level of awareness of the occupant P. For this reason, in recent years, development of a system that detects the level of awareness of the occupant P and displays a warning or the like depending on the result has been underway. When measuring biological information such as the heart rate and respiratory rate of the occupant P in order to detect the level of awareness of the occupant P, it is desirable to measure the biological information by a method that does not contact the body of the occupant P and does not restrain the occupant P due to constraints such as "not interfering with driving" and "necessity of constant measurement."

[0014] Taking these factors into consideration, the biological information detection device 1 is configured as a radio wave transmission type device that detects the biological information of the occupant P based on the radio wave signal that has passed through the occupant P. The biological information detection device 1 targets the occupant P seated in the driver's seat DS among the seats S of the vehicle V, and calculates the heart rate of the target person as biological information. The biological information detection device 1 includes a transmitter 11, a transmitting antenna 12, a receiving antenna 13, a receiver 14, and an information control unit 20.

[0015] The transmitter 11 outputs a transmission signal of a predetermined frequency (for example, a frequency in the 900 MHz band) to the transmitting antenna 12. The transmitting antenna 12 is disposed on the instrument panel inside the vehicle, forward of the driver's seat DS in the traveling direction of the vehicle V. The transmitting antenna 12 transmits a radio signal corresponding to the transmission signal from the transmitter 11 toward the upper body of an occupant P seated in the driver's seat DS.

[0016] The receiving antenna 13 is disposed opposite the transmitting antenna 12 across the occupant P seated in the driver's seat DS. In this embodiment, the receiving antenna 13 is disposed on the seat back of the driver's seat DS. The receiving antenna 13 is configured to be able to receive radio waves transmitted from the transmitting antenna 12. The receiving antenna 13 receives the radio waves radiated from the transmitting antenna 12 and transmitted through the occupant P who is the target.

[0017] The receiver 14 amplifies and outputs the radio signal received by the receiving antenna 13. Specifically, the receiver 14 amplifies the radio signal received by the receiving antenna 13 and outputs the amplified signal to the information control unit 20 as a biological signal P1.

[0018] The information control unit 20 calculates the heart rate of the occupant P based on the biological signal P1 acquired from the receiver 14. The information control unit 20 includes an input unit 21, a storage unit 22, an output unit 23, and a processing unit .

[0019] The input unit 21 is a signal acquisition unit that acquires a reception signal corresponding to radio waves received by the receiving antenna 13 when the radio waves are radiated from the transmitting antenna 12. The input unit 21 outputs the biosignal P1, which is an analog signal input from the receiver 14, to the processing unit 24 as a digital signal.

[0020] The storage unit 22 includes a RAM, a ROM, a writable non-volatile storage medium, etc. The RAM, the ROM, and the writable non-volatile storage medium constituting the storage unit 22 are all non-transient substantial storage media.

[0021] The output unit 23 outputs the signal input from the processing unit 24 to a device external to the information control unit 20. The external device to which the signal is output may be, for example, an in-vehicle navigation device that provides route guidance or the like, an in-vehicle data communication module that communicates with the outside of the vehicle V, or a mobile communication terminal carried by an occupant.

[0022] The processing unit 24 is a device that executes processing according to a program recorded in the ROM of the storage unit 22 or a writable non-volatile storage medium. The processing unit 24 in this embodiment uses the RAM of the storage unit 22 as a working area. The processing unit 24 functions as a calculation unit that calculates bioinformation based on the reception signal acquired by the input unit 21.

[0023] Here, the information control unit 20 is connected to an in-vehicle network via CAN communication. CAN is an abbreviation for Controller Area Network. The information control unit 20 is connected to a CAN bus 30, which is a communication bus. In-vehicle devices such as a drive device 40 for the wiper W, an in-vehicle detection device 50, and an outside-vehicle detection device 60 are connected to this CAN bus 30. The information control unit 20 is capable of acquiring an output signal of the drive device 40 for the wiper W, a detection result of the in-vehicle detection device 50, a detection result of the outside-vehicle detection device 60, and the like via the CAN bus 30.

[0024] The wiper W is a device that wipes the window FW around the occupant P. The wiper W wipes the window FW by periodically reciprocating within a predetermined range on the outer surface of the window FW. The driving device 40 controls the reciprocating movement of the wiper W. Although not shown, the driving device 40 includes a wiper switch, a wiper motor, a motor control unit, and the like, and is operable by power supply from a battery mounted on the vehicle. The wiper switch is provided at a position where the driver can operate it, and has operation positions such as "Lo" and "Hi". When the wiper switch is set to "Lo", the wiper W reciprocates at a low speed, and when the wiper switch is set to "Hi", the wiper W reciprocates at a high speed. The driving device 40 is connected to the CAN bus 30.

[0025] The in-vehicle detection device 50 is a device capable of detecting the movement of a subject around the vehicle. The in-vehicle detection device 50 is composed of, for example, an imaging device for monitoring the inside of the vehicle, an IR sensor for detecting a temperature change in the vehicle cabin, etc. The in-vehicle detection device 50 is connected to the CAN bus 30.

[0026] The outside-vehicle detection device 60 is a device capable of detecting the movement of a target person around the vehicle outside the vehicle. The outside-vehicle detection device 60 is composed of, for example, an imaging device for monitoring the periphery of the vehicle V, an entry system for locking or unlocking the doors in response to a signal from a portable device of the occupant, a camera for displaying the electronic mirror, a millimeter wave radar for measuring the distance to an object around the vehicle V, and the like. The outside-vehicle detection device 60 is connected to the CAN bus 30.

[0027] Next, the operation of the biological information detection device 1 will be described. The transmitter 11 outputs a transmission signal of a predetermined frequency to the transmission antenna 12. The transmission antenna 12 transmits radio waves corresponding to the transmission signal from the transmitter 11 toward the occupant P seated in the driver's seat DS. A part of the radio waves transmitted from the transmission antenna 12 passes through the occupant P seated in the driver's seat DS and is received by the receiving antenna 13.

[0028] The body of the occupant P functions as a dielectric with respect to the radio waves. Therefore, when the radio waves pass through the body of the occupant P, a dielectric loss occurs in the electric field strength of the radio waves. Among the parts of the body of the occupant P, the heart changes shape as it expands and contracts. Therefore, in the radio waves that pass through the heart H and reach the receiving antenna 13, a dielectric loss occurs in the electric field strength, which changes according to the heartbeat of the heart H.

[0029] In this way, the strength of the signal received by the receiving antenna 13 contains a component that changes periodically according to the heartbeat of the heart H. Therefore, the level of the electrical signal output from the receiving antenna 13 to the receiver 14 when the receiving antenna 13 receives the radio waves from the transmitting antenna 12 contains a component that changes according to the heartbeat of the heart H.

[0030] However, in the radio wave transmission type bioinformation detection device 1, due to the characteristics of radio waves, the receiver 14 receives radio waves reflected by objects around the occupant P who is the subject. Therefore, if there is any movement around the occupant P who is the subject, the received signal used to calculate the bioinformation fluctuates. That is, the received signal used to calculate the bioinformation may contain signal components caused by the movement around the subject. For example, when the wipers W are operated in rainy weather, the received signal contains signal components caused by the movement of the wipers W in addition to the components corresponding to the heart rate. This is undesirable because it causes a decrease in the detection accuracy of the bioinformation.

[0031] In contrast, the biometric information detection device 1 of this embodiment identifies the signal components arising from the movement of the wiper W as noise contained in the received signal received by the receiving antenna 13, and calculates the biometric information from the received signal after removing the identified signal components.

[0032] The flow of processing executed by the processing unit 24 of the information control unit 20 will be described below with reference to Fig. 2, Fig. 3, etc. The processing shown in Fig. 2 is executed by the information control unit 20 periodically or irregularly when an occupant is seated in the driver's seat DS of the vehicle V.

[0033] As shown in Fig. 2, in step S100, when radio waves are transmitted from the transmitting antenna 12, the processing unit 24 acquires, via the receiver 14, a time waveform of a received signal received by the receiving antenna 13. The time waveform of the received signal is a time change in the signal strength of the received signal. For example, the time waveform is as shown in the upper part of Fig. 4. This time waveform includes not only components that are correlated with the heartbeat but also components that are unrelated to the heartbeat.

[0034] Next, in step S110, the processing unit 24 performs a filter process to remove noise components contained in the received signal. For example, the processing unit 24 removes the noise components contained in the received signal using a filter that passes a frequency band of components that have a correlation with the heart rate. As a result, for example, a time waveform shown in the middle part of FIG. 4 is obtained.

[0035] Next, in step S120, the processing unit 24 performs a Fourier transform on the time waveform obtained in step S110 to calculate the frequency characteristics of the received signal. The frequency characteristics are characteristics that indicate the relationship between frequency and intensity. As a result, for example, the frequency characteristics shown in the lower part of Fig. 4 are obtained. In the lower part of Fig. 4, the horizontal axis indicates frequency and the vertical axis indicates signal intensity.

[0036] Next, in step S130, the processing unit 24 determines whether the wipers W are operating. This determination is made based on, for example, an output signal from the driving device 40, including an operation signal of a wiper switch and a power supply state to a wiper motor.

[0037] When the wiper W is stopped, the processing unit 24 proceeds to step S140 and identifies a peak intensity SP that has a correlation with the heartbeat in the frequency characteristics. For example, as shown in Fig. 5, the processing unit 24 identifies the peak intensity SP that has the largest intensity in the frequency characteristics as the intensity that has a correlation with the heartbeat. Then, the processing unit 24 extracts the identified peak intensity SP and the frequency corresponding to the peak intensity SP as a component that has a correlation with the heartbeat.

[0038] Next, the processing unit 24 proceeds to step S150 and calculates the heart rate from the components having a correlation with the heart rate extracted in step S140. Specifically, the processing unit 24 obtains the heart rate expressed in bmp units by multiplying the value, which is expressed in Hz units, of the frequency corresponding to the peak strength SP in the frequency characteristics of the received signal by 60. bpm is an abbreviation of beats per minute, and is a unit that expresses the number of heart beats per minute. For example, if the frequency Hz corresponding to the peak strength SP is 1 Hz, the heart rate is multiplied by 60 to obtain 60 bpm.

[0039] Next, in step S160, the processing unit 24 outputs the heart rate calculated in step S150 from the output unit 23 to a device external to the biological information detecting device 1. The processing unit 24 may be configured to output the heart rate to a driver status monitor DSM that detects the wakefulness, etc. of the occupant P based on the heart rate of the occupant P, for example.

[0040] On the other hand, when the wiper W is operating, the received signal includes a component caused by the fluctuation of the wiper W in addition to a component caused by the fluctuation of the heartbeat, as shown in FIG. 6. The frequency characteristic of the received signal includes a component correlated with the movement of the wiper W in addition to a component correlated with the heartbeat, as shown in FIG. 7. Incidentally, the time waveform of the received signal when the wiper W is operating includes not only a component correlated with the heartbeat, but also a component correlated with the movement of the wiper W, as shown in the first and second rows of FIG. 8. The frequency characteristic of the received signal includes two peak intensities SP1 and SP2, as shown in the third row of FIG. 8. One of these two peak intensities SP1 and SP2 is correlated with the heartbeat, and the other is noise unrelated to the heartbeat.

[0041] Taking these factors into consideration, if the wipers W are operating, the processing unit 24 proceeds to step S170 and executes the noise removal process. The noise removal process will be described below with reference to the flowchart of FIG.

[0042] 3, in step S171, the processing unit 24 identifies the operating frequency of the wiper W from the output signal of the driving device 40 of the wiper W. The processing unit 24 identifies whether the wiper W is operating in "Lo" or "Hi" from the operation signal of the wiper switch, and identifies the operating frequency of the wiper W from the identified reciprocating speed of the wiper W.

[0043] Next, in step S172, the processing unit 24 identifies a signal component included in the received signal and caused by the movement of the wiper W. The processing unit 24 extracts a feature point that peaks near the operating frequency of the wiper W identified in step S171 in the frequency characteristics of the received signal, and identifies the intensity and frequency of the extracted feature point as the signal component caused by the movement of the wiper W.

[0044] Next, in step S173, the processing unit 24 removes the signal components caused by the movement of the wiper W from the received signal as noise, and ends the noise removal process. Specifically, the processing unit 24 uses a filter that cuts the frequency band of the feature point extracted in step S171 to remove the signal components caused by the movement of the wiper W contained in the received signal from the frequency characteristics of the received signal. For example, as shown in the fourth row of Fig. 8, the processing unit 24 removes the signal components caused by the movement of the wiper W contained in the received signal. As a result, the frequency characteristics shown in the fifth row of Fig. 8 are obtained.

[0045] Here, if the operating frequency of the wiper W is the same as the heartbeat, for example, a component that is correlated with the heartbeat and a component that is correlated with the movement of the wiper W are combined, and one peak intensity SP appears in the frequency characteristics of the received signal, as shown in the upper part of Figure 9.

[0046] In this way, when only one peak intensity SP appears while the wiper W is operating, the processing unit 24 identifies the frequency at which the peak intensity SP occurs as the signal component caused by the movement of the wiper W. Then, the signal intensity α caused by the movement of the wiper W is estimated, and the estimated signal intensity α is removed from the peak intensity SP. As a result, for example, the frequency characteristics shown in the lower part of FIG. 9 can be obtained. Note that the signal intensity α caused by the movement of the wiper W may be an estimated value obtained in advance by an experiment or simulation, or may be an actual value measured in advance.

[0047] After the noise removal process, the processing unit 24 proceeds to step S140 and identifies a peak intensity SP that has a correlation with the heartbeat in the frequency characteristics from which the noise has been removed in step S170. Then, the processing unit 24 extracts the identified peak intensity SP and the frequency corresponding to the peak intensity SP as a component that has a correlation with the heartbeat.

[0048] Next, the processing unit 24 proceeds to step S150 and calculates the heart rate from the components having a correlation with the heart rate extracted in step S140. After that, in step S160, the processing unit 24 outputs the heart rate calculated in step S150 from the output unit 23 to a device external to the biological information detection device 1.

[0049] The processing unit 24 of the biometric information detection device 1 described above identifies signal components caused by the subject's surrounding movements, and calculates biometric information from the received signal after removing the signal components. This makes it possible to suppress a decrease in detection accuracy of the biometric information caused by the subject's surrounding movements.

[0050] (1) The processing unit 24 of this embodiment identifies signal components caused by the movements of the occupant's surroundings from the output signal of the in-vehicle device and removes the signal components from the received signal. This makes it possible to suppress a decrease in detection accuracy of biological information caused by the movements of the occupant's surroundings.

[0051] (2) Specifically, the processing unit 24 detects the operating frequency of the wiper W from the output signal of the driving device 40 of the wiper W, and removes, as noise, components corresponding to the operating frequency from the received signal. This allows the biological information to be calculated from the received signal from which the signal components caused by the movement of the wiper W have been removed, thereby making it possible to suppress a decrease in detection accuracy of the biological information caused by the movement of the wiper W.

[0052] (Modification of the first embodiment) In the first embodiment, the noise removal process is exemplified by detecting the operating frequency of the wiper W from the output signal of the driving device 40 of the wiper W and removing the components corresponding to the operating frequency from the received signal, but the noise removal process is not limited to this. For example, the noise removal process may be configured to determine the operating frequency of the wiper W in advance and remove the components corresponding to the operating frequency from the received signal.

[0053] The processing performed by the processing unit 24 may be such that, when only one peak intensity SP appears in the frequency characteristics of the received signal, the noise removal processing is skipped and the frequency at which the peak intensity SP occurs is identified as a component having a correlation with the heartbeat. That is, when only one peak intensity SP appears in the frequency characteristics of the received signal calculated in step S120, steps S130 and S170 may be skipped and the process proceeds to step S140. The processing performed by the processing unit 24 described in the first embodiment can be combined with the processing performed by the processing unit 24 described in the following embodiments. This also applies to the following embodiments.

[0054] Second embodiment Next, a second embodiment will be described with reference to Figures 10 and 11. In this embodiment, differences from the first embodiment will be mainly described.

[0055] As described in the first embodiment, in the radio wave transmission type biological information detection device 1, if there is any movement around the subject occupant P, the received signal used to calculate the biological information fluctuates. For example, if a passenger riding around the subject in a car moves, the received signal will contain signal components caused by the passenger's movement in addition to components corresponding to the heart rate. This is undesirable because it can cause a decrease in the detection accuracy of the biological information.

[0056] In contrast, the biometric information detection device 1 of this embodiment identifies signal components arising from the movement of the subject around the vehicle as noise contained in the received signal received by the receiving antenna 13, and calculates the biometric information from the received signal after removing the identified signal components.

[0057] Hereinafter, the flow of processing executed by the information control unit 20 of the biological information detection device 1 will be described with reference to Fig. 10 and Fig. 11. The processing shown in Fig. 10 corresponds to the processing shown in Fig. 2 described in the first embodiment. Among the processing shown in Fig. 10, the processing of steps S200 to S220 is similar to the processing of steps S100 to S120 shown in Fig. 2, and therefore the description thereof will be simplified.

[0058] 10, in step S200, the processing unit 24 acquires a time waveform of a received signal received by the receiving antenna 13 via the receiver 14 when a radio wave is transmitted from the transmitting antenna 12. Then, in step S210, the processing unit 24 performs a filter process to remove noise components contained in the received signal. Furthermore, in step S220, the processing unit 24 performs a Fourier transform on the time waveform acquired in step S210 to calculate the frequency characteristics of the received signal.

[0059] Next, in step S230, the processing unit 24 determines whether or not movement inside the vehicle has been detected. Specifically, the processing unit 24 determines whether or not movement around the subject inside the vehicle has been detected by the in-vehicle detection device 50. When the in-vehicle detection device 50 is an imaging device that captures the inside of the vehicle, the detection of movement around the subject can be performed, for example, by optical flow or a frame difference method.

[0060] If the in-vehicle detection device 50 does not detect any movement around the subject in the vehicle, the processing unit 24 proceeds to step S240 and identifies a peak intensity SP that has a correlation with the heartbeat in the frequency characteristics. Then, the processing unit 24 extracts the identified peak intensity SP and the frequency corresponding to the peak intensity SP as a component that has a correlation with the heartbeat.

[0061] Next, the processing unit 24 proceeds to step S250 and calculates the heart rate from the components having a correlation with the heart rate extracted in step S240. Then, in step S260, the processing unit 24 outputs the heart rate calculated in step S250 from the output unit 23 to a device external to the biological information detection device 1.

[0062] On the other hand, when the in-vehicle detection device 50 detects the movement of the subject around the vehicle, the processing unit 24 removes, as noise, the frequency component corresponding to the detection result of the in-vehicle detection device 50 from the received signal. Specifically, the processing unit 24 proceeds to step S270 and executes noise removal processing. The noise removal processing will be described below with reference to the flowchart of FIG.

[0063] 11, in step S271, the processing unit 24 identifies the motion frequency of the motion around the occupant inside the vehicle. The processing unit 24 extracts a component that is correlated with the motion around the occupant included in the output signal of the in-vehicle detection device 50, and identifies a characteristic frequency component in the extracted components as the motion frequency of the motion around the occupant inside the vehicle. In this process, not only one frequency but multiple frequencies may be identified as the motion frequency.

[0064] Next, in step S272, the processing unit 24 identifies signal components caused by the movement around the occupant in the vehicle from the received signal. The processing unit 24 extracts feature points that have peaks near the motion frequencies of the movement around the occupant identified in step S271 in the frequency characteristics of the received signal, and identifies the strength and frequency of the extracted feature points as signal components caused by the movement around the occupant in the vehicle.

[0065] Next, in step S273, the processing unit 24 removes, as noise, signal components caused by the movements around the occupant in the vehicle from the received signal, and ends the noise removal process. Specifically, the processing unit 24 removes, from the frequency characteristics of the received signal, signal components caused by the movements around the occupant in the vehicle, contained in the received signal, using a filter that cuts the frequency band of the feature points extracted in step S271.

[0066] Here, if the motion frequency of the occupant's surrounding movement in the vehicle is the same as the heartbeat, a component correlated with the heartbeat and a component correlated with the occupant's surrounding movement are combined, and one peak strength SP may appear in the frequency characteristics of the received signal. In such a case, the processing unit 24 identifies the frequency at which the peak strength SP occurs as a signal component caused by the occupant's surrounding movement in the vehicle. Then, the processing unit 24 estimates the signal strength caused by the occupant's surrounding movement in the vehicle and removes the estimated signal strength from the peak strength SP. Note that the signal strength caused by the occupant's surrounding movement in the vehicle may be an estimated value obtained in advance by experiment or simulation, or may be an actual measurement value measured in advance.

[0067] After the noise removal process, the processing unit 24 proceeds to step S240 and identifies a peak intensity SP that has a correlation with the heartbeat in the frequency characteristics from which the noise has been removed in step S270. Then, the processing unit 24 extracts the identified peak intensity SP and the frequency corresponding to the peak intensity SP as a component that has a correlation with the heartbeat.

[0068] Next, the processing unit 24 proceeds to step S250 and calculates the heart rate from the components having a correlation with the heart rate extracted in step S240. After that, in step S260, the processing unit 24 outputs the heart rate calculated in step S250 from the output unit 23 to a device external to the biological information detection device 1.

[0069] The rest is the same as in the first embodiment. The biological information detection device 1 of this embodiment can obtain the same effects as in the first embodiment, which are achieved by a configuration common to the first embodiment or an equivalent configuration.

[0070] (1) The biological information detection device 1 of this embodiment removes, as noise, frequency components corresponding to the detection results of the in-vehicle detection device 50 from the received signal. As a result, the biological information is calculated from the received signal from which signal components caused by the movements of the subject around the subject in the vehicle have been removed, so that it is possible to suppress a decrease in detection accuracy of the biological information caused by the movements of the subject around the subject in the vehicle.

[0071] (2) The processing unit 24 may be configured to suppress output of the biological information depending on the detection result of the in-vehicle detection device 50. For example, when there is a large movement inside the vehicle, such as a passenger getting in or out of the vehicle, it may be difficult to extract the movement around the occupant based on the detection result of the in-vehicle detection device 50. For this reason, the processing unit 24 may be configured to skip each process and temporarily stop output of the biological information when a condition is established that makes it difficult to detect the movement around the occupant based on the output signal of the in-vehicle detection device 50.

[0072] Here, the condition for suppressing the output of the biological information is not limited to a condition that is satisfied when there is a large movement inside the vehicle, such as passengers getting on and off, etc. The condition may be a condition that is satisfied when the movement inside the vehicle is not periodic, or when a stationary object is placed in most of the detection range of the in-vehicle detection device 50, for example.

[0073] (Modification of the second embodiment) The process executed by the processing unit 24 may be configured to skip steps S230 and S270 and proceed to step S240 if only one peak intensity SP appears in the frequency characteristic of the received signal calculated in step S220.

[0074] Third embodiment Next, a third embodiment will be described with reference to Figures 12 and 13. In this embodiment, differences from the first embodiment will be mainly described.

[0075] In the radio wave transmission type biometric information detection device 1, for example, if there is movement around the subject outside the vehicle, the signal components caused by this movement will be included in the received signal. This is undesirable because it can lead to a decrease in the detection accuracy of the biometric information. The movement around the subject outside the vehicle can be pedestrians around the vehicle or the movement of objects close to the vehicle V.

[0076] In contrast, the biometric information detection device 1 of this embodiment identifies signal components caused by movement outside the vehicle as noise contained in the received signal received by the receiving antenna 13, and calculates the biometric information from the received signal after removing the identified signal components.

[0077] Hereinafter, the flow of processing executed by the information control unit 20 of the biological information detection device 1 will be described with reference to Fig. 12. The processing shown in Fig. 12 corresponds to the processing shown in Fig. 2 described in the first embodiment. Among the processing shown in Fig. 12, the processing of steps S300 to S320 is similar to the processing of steps S100 to S120 shown in Fig. 2, and therefore the description thereof will be simplified.

[0078] 12, in step S300, the processing unit 24 acquires a time waveform of a received signal received by the receiving antenna 13 via the receiver 14 when a radio wave is transmitted from the transmitting antenna 12. Then, in step S310, the processing unit 24 performs a filter process to remove noise components contained in the received signal. Furthermore, in step S320, the processing unit 24 performs a Fourier transform on the time waveform acquired in step S310 to calculate the frequency characteristics of the received signal.

[0079] Next, in step S330, the processing unit 24 determines whether or not movement outside the vehicle has been detected. Specifically, the processing unit 24 determines whether or not movement around the subject outside the vehicle has been detected by the outside-vehicle detection device 60. If the outside-vehicle detection device 60 is an imaging device that captures the outside of the vehicle, the detection of movement around the subject can be performed, for example, by optical flow or a frame difference method.

[0080] If the outside-vehicle detection device 60 does not detect any movement around the subject outside the vehicle, the processing unit 24 proceeds to step S340 and identifies a peak intensity SP that has a correlation with the heartbeat in the frequency characteristics. Then, the processing unit 24 extracts the identified peak intensity SP and the frequency corresponding to the peak intensity SP as a component that has a correlation with the heartbeat.

[0081] Next, the processing unit 24 proceeds to step S350 and calculates the heart rate from the components having a correlation with the heart rate extracted in step S340. Then, in step S360, the processing unit 24 outputs the heart rate calculated in step S350 from the output unit 23 to a device external to the biological information detection device 1.

[0082] On the other hand, when movement around the subject outside the vehicle is detected, the processing unit 24 removes, as noise, the frequency component corresponding to the detection result of the outside-vehicle detection device 60 from the received signal. Specifically, the processing unit 24 proceeds to step S370 and executes noise removal processing. The noise removal processing will be described below with reference to the flowchart of FIG.

[0083] 13, in step S371, the processing unit 24 identifies the motion frequency of the motion around the occupant outside the vehicle. The processing unit 24 extracts a component that is correlated with the motion around the occupant included in the output signal of the outside-vehicle detection device 60, and identifies a characteristic frequency component in the extracted components as the motion frequency of the motion around the occupant outside the vehicle. In this process, not only one frequency but multiple frequencies may be identified as the motion frequency.

[0084] Next, in step S372, the processing unit 24 identifies signal components caused by the movement around the occupant outside the vehicle from the received signal. The processing unit 24 extracts feature points that have peaks near the motion frequencies of the movement around the occupant identified in step S371 in the frequency characteristics of the received signal, and identifies the strength and frequency of the extracted feature points as signal components caused by the movement around the occupant outside the vehicle.

[0085] Next, in step S373, the processing unit 24 removes, as noise, signal components caused by the movement of the occupant around the vehicle from the received signal, and ends the noise removal process. Specifically, the processing unit 24 removes the signal components caused by the movement of the occupant around the vehicle, which are included in the received signal, using a filter that cuts the frequency band of the operating frequency extracted in step S371 from the frequency characteristics of the received signal.

[0086] Here, if the motion frequency of the occupant's surrounding movement outside the vehicle is the same as the heartbeat, a component correlated with the heartbeat and a component correlated with the occupant's surrounding movement are combined, and one peak intensity SP may appear in the frequency characteristics of the received signal. In such a case, the processing unit 24 identifies the frequency at which the peak intensity SP occurs as a signal component caused by the occupant's surrounding movement outside the vehicle. Then, the processing unit 24 estimates the signal intensity caused by the occupant's surrounding movement outside the vehicle and removes the estimated signal intensity from the peak intensity SP. Note that the signal intensity caused by the occupant's surrounding movement outside the vehicle may be an estimated value obtained in advance by experiment or simulation, or may be an actual measurement value measured in advance.

[0087] After the noise removal process, the processing unit 24 proceeds to step S340, where it identifies intensities that are characteristic points correlating with the heartbeat in the frequency characteristics from which noise has been removed in step S370. Then, the processing unit 24 extracts the identified peak intensities and frequencies corresponding to the peak intensities as components correlating with the heartbeat.

[0088] Next, the processing unit 24 proceeds to step S350 and calculates the heart rate from the components having a correlation with the heart rate extracted in step S340. After that, in step S360, the processing unit 24 outputs the heart rate calculated in step S350 from the output unit 23 to a device external to the biological information detection device 1.

[0089] The rest is the same as in the first embodiment. The biological information detection device 1 of this embodiment can obtain the same effects as in the first embodiment, which are achieved by a configuration common to the first embodiment or an equivalent configuration.

[0090] (1) The biological information detection device 1 of this embodiment removes, as noise, frequency components corresponding to the detection results of the outside-vehicle detection device 60 from the received signal. As a result, the biological information is calculated from the received signal from which signal components caused by the movements of the subject outside the vehicle are removed, so that it is possible to suppress a decrease in detection accuracy of the biological information caused by the movements of the subject outside the vehicle.

[0091] (2) The processing unit 24 may be configured to suppress the output of the bioinformation in response to the output signal of the outside-vehicle detection device 60. For example, if there is a large movement outside the vehicle, it may be difficult to detect the movement around the occupant based on the output signal of the outside-vehicle detection device 60. For this reason, the processing unit 24 may be configured to skip each process and temporarily stop the output of the bioinformation when a condition is established that makes it difficult to detect the movement around the occupant based on the output signal of the outside-vehicle detection device 60.

[0092] (Modification of the third embodiment) The process executed by the processing unit 24 may be configured to skip steps S330 and S370 and proceed to step S340 if only one peak intensity SP appears in the frequency characteristic of the received signal calculated in step S320.

[0093] (Other embodiments) Representative embodiments of the present disclosure have been described above, but the present disclosure is not limited to the above-described embodiments and can be modified in various ways, for example, as described below.

[0094] In the above embodiment, an example has been described in which the biometric information is calculated from the frequency characteristics of the received signal after removing the frequency band corresponding to the signal components caused by the subject's surrounding movements, but the biometric information detection device 1 may be configured to calculate the biometric information by other methods. For example, the biometric information detection device 1 may be configured to calculate the biometric information from the received signal after removing the signal components caused by the subject's surrounding movements, using the time characteristics obtained by performing an inverse Fourier transform on the frequency characteristics of the subject's surrounding movements.

[0095] In the above embodiment, the heart rate is calculated as the biological information, but the biological information detection device 1 may be configured to calculate biological information other than the heart rate (for example, respiratory rate, pulse rate).

[0096] In the above embodiment, an example in which the biometric information detection device 1 of the present disclosure is applied to a vehicle V equipped with an automatic driving system has been described, but the application target of the biometric information detection device 1 is not limited thereto. The biometric information detection device 1 can also be applied to a vehicle V not equipped with an automatic driving system. For example, the transmitting antenna 12 and the receiving antenna 13 of the biometric information detection device 1 may be arranged on the left and right sides of the vehicle V with an occupant in between. The biometric information detection device 1 may be configured to calculate biometric information of not only the driver but also other occupants P. In addition, the biometric information detection device 1 may be used not only for calculating the biometric information of the occupant of the vehicle V, but also for calculating the biometric information of a person outside the vehicle (for example, inside a building).

[0097] In the above-described embodiments, it goes without saying that the elements constituting the embodiments are not necessarily essential, except in cases where it is particularly expressly stated that they are essential or where they are clearly considered to be essential in principle.

[0098] In the above-described embodiments, when numerical values ​​such as the number, values, amounts, ranges, etc. of components of the embodiments are mentioned, they are not limited to the specific numbers unless it is specifically stated as required or unless it is clearly limited to a specific number in principle.

[0099] In the above-described embodiments, when referring to the shapes, positional relationships, etc. of components, etc., there is no limitation to those shapes, positional relationships, etc., unless specifically stated or in principle limited to a specific shape, positional relationship, etc.

[0100] In the above-described embodiment, when the external environment information of the vehicle is acquired from a sensor, it is also possible to eliminate the sensor and receive the external environment information from a server or cloud outside the vehicle. Alternatively, it is also possible to eliminate the sensor and acquire related information related to the external environment information from a server or cloud outside the vehicle, and estimate the external environment information from the acquired related information.

[0101] The control unit and the method of the present disclosure may be implemented in a special-purpose computer provided by configuring a processor and a memory programmed to execute one or more functions embodied in a computer program. The control unit and the method of the present disclosure may be implemented in a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits. The control unit and the method of the present disclosure may be implemented in one or more special-purpose computers configured with a processor and a memory programmed to execute one or more functions and a processor configured with one or more hardware logic circuits. The computer program may also be stored in a computer-readable non-transitory tangible recording medium as instructions executed by a computer. [Explanation of symbols]

[0102] 1 Biometric information detection device 12 Transmitting Antenna 13 Receiving antenna 21 Input section (signal acquisition section) 24 Processing section (calculation section)

Claims

1. A biological information detection device for detecting biological information of a subject, a receiving antenna (13) for receiving radio waves radiated from the transmitting antenna (12) and transmitted through the subject; a signal acquisition unit (21) that acquires a received signal corresponding to the radio waves received by the receiving antenna when the radio waves are radiated from the transmitting antenna; A calculation unit (24) that calculates the biological information based on the received signal acquired by the signal acquisition unit, the calculation unit is configured to identify a signal component caused by the movement of the subject around the subject as noise included in the received signal based on an output signal of an in-vehicle device (40, 50, 60), and calculate the biological information from the received signal after removing the signal component; A biological information detection device, wherein the output signal of the in-vehicle device is a signal different from the received signal corresponding to the radio waves received by the receiving antenna.

2. The subject is one of the occupants seated in a seat (S) of a vehicle, The biological information detection device according to claim 1 , wherein the calculation unit identifies the signal component caused by a movement around the subject based on an output signal of the in-vehicle device.

3. The in-vehicle device is a driving device (40) of a wiper (W) that wipes a window around the subject, The biological information detection device according to claim 2 , wherein the calculation unit detects an operating frequency of the wiper from an output signal of the driving device, and removes a component corresponding to the operating frequency from the received signal as the noise.

4. The in-vehicle device is an in-vehicle detection device (50) capable of detecting the movement of the subject around the subject in the vehicle, The biological information detection device according to claim 2 , wherein the calculation unit removes, as the noise, a frequency component corresponding to a detection result of the in-vehicle detection device from the received signal.

5. The in-vehicle device is an outside-vehicle detection device (60) capable of detecting movements around the subject outside the vehicle, 5. The biological information detection device according to claim 2, wherein the calculation unit removes, from the received signal, a frequency component corresponding to the detection result of the outside-of-vehicle detection device as the noise.

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