Biometric information detection device

Abstract

To detect biometric information with high accuracy.SOLUTION: A biometric information detection device includes: a sensor that detects information related to a person's body movement; a frequency analysis unit that performs frequency analysis on a detection signal of the information related to the body movement detected by the sensor; a filter processing unit that generates a filter on the basis of results of the frequency analysis and applies the generated filter to the detection signal; and a detection unit that detects biometric information, which is the heartbeat interval, on the basis of a detection signal before application of the filter corresponding to the peak of a detection signal after application of the filter.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a biological information detection device. [Background technology]

[0002] Conventionally, there have been known techniques for detecting biological information by acquiring human body movements. For example, Patent Document 1 discloses a technique for extracting a heartbeat waveform by inversely converting a heartbeat signal in a passband using a filter that uses the maximum peak in the 0.5 to 2 Hz range as a fundamental frequency and a harmonic band up to a fourth harmonic, which is four times the fundamental frequency, as a passband by frequency conversion. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-22638 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with this conventional technology, when noise is superimposed exactly on the harmonic band or when the signal strength of a specific harmonic component is insufficient due to physical constitution or sensor contact, the signal-to-noise ratio of the signal waveform after filtering deteriorates. Furthermore, with this conventional technology, when noise is superimposed near the fundamental frequency, the fundamental frequency cannot be accurately estimated. Therefore, with this conventional technology, it was sometimes difficult to detect biological information such as heart rate with high accuracy.

[0005] The present invention has been made in view of the above, and an object of the present invention is to provide a biological information detection device and a biological information detection method that can detect biological information with high accuracy. [Means for solving the problem]

[0006] The biometric information detection device of the present invention comprises a sensor that detects information related to a person's body movements, a frequency analysis unit that performs frequency analysis on the detection signal of the information related to the body movements detected by the sensor, a filter processing unit that generates a filter based on the results of the frequency analysis and applies the generated filter to the detection signal, and a detection unit that detects biometric information, which is the interval between heartbeats, based on the detection signal before application of the filter that corresponds to the peak of the detection signal after application of the filter. [Effects of the Invention]

[0007] According to the biological information detecting device of the present invention, biological information can be detected with high accuracy. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a vehicle according to the first embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of the air pressure sensor according to the first embodiment. [Figure 3] FIG. 3 is a block diagram showing an example of a system configuration and a hardware configuration of the biological information detection system according to the first embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of the functional configuration of the biological information detecting device according to the first embodiment. [Figure 5] FIG. 5 is a flowchart illustrating an example of a procedure for biological information detection processing according to the first embodiment. [Figure 6] FIG. 6 is a diagram showing an example of a waveform of a frequency analysis result according to the first embodiment. [Figure 7] FIG. 7 is a flowchart showing an example of a procedure of a fundamental frequency estimation process according to the first embodiment. [Figure 8] FIG. 8 is a flowchart showing an example of a procedure for the filtering process according to the first embodiment. [Figure 9] FIG. 9 is a flowchart illustrating an example of a procedure for peak detection processing according to the first embodiment. [Figure 10]FIG. 10 is a diagram showing a comparison between a detection signal before application of a filter and a detection signal after application of a filter according to the first embodiment. [Figure 11] FIG. 11 is a flowchart illustrating an example of a procedure for the peak correction process according to the first embodiment. [Figure 12] FIG. 12 is a flowchart illustrating an example of a procedure for biological information detection processing according to the second embodiment. [Figure 13] FIG. 13 is a flowchart illustrating an example of a procedure for a fundamental frequency estimation process according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Exemplary embodiments of the present invention are disclosed below. The configurations of the embodiments described below, as well as the actions, results, and advantages brought about by the configurations, are merely examples. The present invention can be realized with configurations other than those disclosed in the following embodiments, and it is possible to obtain at least one of the various advantages based on the basic configurations and derivative advantages.

[0010] (First embodiment) FIG. 1 is a diagram showing an example of the configuration of a vehicle 1 according to the first embodiment. The vehicle 1 is an example of a moving body on which a biometric information detection device is mounted. The biometric information detection device according to this embodiment estimates the state of a driver 2 who is driving the vehicle 1 and occupants including persons other than the driver 2. The example in FIG. 1 shows an example of detecting the state of the driver 2.

[0011] The vehicle 1 according to this embodiment includes an air pressure sensor 12 and a camera 14. In addition, the vehicle 1 includes a biological information detection system 100 (see FIG. 3) which will be described later.

[0012] The air pressure sensor 12 is a sensor for detecting body movement, which is movement of the body surface of an occupant such as the driver 2. The air pressure sensor 12 outputs a signal of the detected body movement. In this embodiment, the air pressure sensor 12 detects a signal related to the heartbeat (pulsation) of the occupant as the body movement. The signal detected by the air pressure sensor 12 is referred to as a detection signal.

[0013] The air pressure sensor 12 is installed inside the backrest 22. In this embodiment, the air pressure sensor 12 is used as a sensor for detecting the heartbeat as a body movement, but the sensor for acquiring the heartbeat is not limited to this. For example, a Doppler sensor or the like can also be used as the sensor for acquiring the heartbeat.

[0014] Camera 14 is a device that acquires image data of driver 2 seated in seat 21. The camera 14 illustrated here is placed near the boundary between roof 31 and windshield 32, and acquires image data including the face of driver 2 from a position diagonally above and in front of driver 2. By analyzing the image data, information regarding changes in the appearance of driver 2, such as line of sight movement, eye movement, and body movement, can be acquired.

[0015] Next, the air pressure sensor 12 will be described in detail. FIG. 2 is a diagram showing an example of the configuration of the air pressure sensor 12 according to the first embodiment. The air pressure sensor 12 includes an air pressure source 1201 configured with a pump or the like, a variable bladder 1202 , a pressure introduction section 1203 , and a pressure sensor 1024 provided at the tip of the pressure introduction section 1203 .

[0016] Air pressure source 1201 and pressure sensor 1204 are connected to processor 121 of biological information detection device 111 (see FIG. 3), which will be described later. Processor 121 detects body movement as biological information based on the detection signal of pressure sensor 1204, and controls variable bladders 1202 individually via air pressure source 1201.

[0017] The variable bladder 1202 is an air bag that can be deformed in response to supply pressure and pressure fluctuations caused by the body movements of a passenger such as the driver 2 . Pressure introducing part 1203 is connected to one end of variable bladder 1202, and the other end is closed and equipped with pressure sensor 1204. Pressure introducing part 1203 is a tubular member capable of transmitting supply pressure and pressure fluctuations caused by the body movements of occupants such as driver 2. The internal volume of pressure introducing part 1203 is set to be sufficiently small compared to the internal volume of variable bladder 1202 in order to transmit pressure changes with high precision and speed.

[0018] Furthermore, pressure introducing portion 1203 is made of a material that can transmit pressure to pressure sensor 1204 while maintaining its shape so as not to absorb pressure fluctuations even when variable bladder 1202 deforms based on pressure changes in the air supplied from air pressure source 1201. Furthermore, pressure introducing portion 1203 is provided in a predetermined space within the seat of vehicle 1, is supported by an appropriate support member, and is designed so that deformation when the supply pressure changes is not hindered.

[0019] The pressure sensor 1204 is provided at the other end of the pressure introducing portion 1203, and detects the supply pressure and the pressure caused by the body movement of the occupant, and outputs a pressure detection signal.

[0020] In this embodiment, the air pressure source 1201 , the variable bladder 1202 , the pressure introducing portion 1203 and the pressure sensor 1204 are housed as an air pressure sensor 12 inside the seat of the vehicle 1 .

[0021] In the above configuration, the pressure introduction section 1203 is provided with the air introduction pipe 1206 of the air pressure source 1201 at a position separated from (ideally opposite to) the position where the variable bladder 1202 is provided so that the pressure introduction section 1203 is not affected by pulsation when the supply pressure fluctuates.

[0022] Next, the biological information detection system 100 of this embodiment will be described. Fig. 3 is a diagram showing an example of a system configuration and a hardware configuration of the biological information detection system 100 according to the first embodiment. As shown in Fig. 3, the biological information detection system 100 includes a biological information detection device 111 and a vehicle control system 112. Here, the biological information detection device 111 and the vehicle control system 112 are connected to each other by wire or wirelessly.

[0023] The biological information detection device 111 is a device that detects biological information of an occupant such as the driver 2 of the vehicle 1. As shown in FIG. 3, the biological information detection device 111 includes an air pressure sensor 12, a processor 121, and the like.

[0024] The processor 121 is an information processing device that performs various arithmetic processing according to a program, and is configured using, for example, a CPU (Central Processing Unit), RAM (Random Access Memory), ROM (Read Only Memory), SSD (Solid State Drive), I / F (Interface), etc. The processor 121 loads a program stored in the ROM or SSD into the RAM, and executes arithmetic processing and control processing for estimating the state of the driver 2. The processor 121 transmits and receives various information to and from other devices via the I / F.

[0025] The processor 121 according to this embodiment executes processing for detecting biological information of an occupant such as the driver 2 based on a detection signal related to a heartbeat as a detection signal related to body movement acquired by the air pressure sensor 12. At this time, the biological information of the occupant such as the driver 2 detected by the processor 121 is output to the vehicle control system 112.

[0026] As shown in FIG. 3 , the vehicle control system 112 includes an ECU (Electronic Control Unit) 131, a drive mechanism 132, a braking mechanism 133, a steering mechanism 134, a user I / F 135, and the like. The drive mechanism 132 is a mechanism including a drive source (e.g., an engine, a motor, etc.) of the vehicle 1. The braking mechanism 133 is a mechanism that decelerates and stops the vehicle 1. The steering mechanism 134 is a mechanism that changes the traveling direction of the vehicle 1. The user I / F 135 is a display, a speaker, an operation unit, and the like that are provided inside the vehicle. The ECU 131 is an information processing device that executes various processes to control the drive mechanism 132, the braking mechanism 133, the steering mechanism 134, the user I / F 135, and the like. The ECU 131 according to this embodiment executes predetermined control using biological information, etc. output from the biological information detection device 111. The ECU 131 controls the drive mechanism 132, the braking mechanism 133, the steering mechanism 134, the user I / F 135, etc. so that a danger avoidance action is realized based on, for example, biological information, etc. The danger avoidance action may be, for example, a warning to the driver 2, deceleration or stopping of the vehicle 1, etc.

[0027] Fig. 4 is a diagram showing an example of the functional configuration of the biological information detection device 111 of the first embodiment. As shown in Fig. 4, the biological information detection device 111 of this embodiment mainly includes an acquisition unit 201, a frequency analysis unit 202, a noise level estimation unit 203, a fundamental frequency estimation unit 204, a filter processing unit 205, a peak detection unit 206, a peak correction unit 207, and an output unit 208. These functional units are realized by cooperation between hardware elements and software elements (programs, etc.) of the biological information detection device 111. Furthermore, at least one of these functional units may be configured by dedicated hardware (circuits, etc.).

[0028] The acquisition unit 201 acquires a body movement detection signal output from the air pressure sensor 12, that is, a detection signal related to the heartbeat.

[0029] The frequency analysis unit 202 performs frequency analysis processing such as fast Fourier transform on the detection signal acquired by the acquisition unit 201, and outputs a frequency domain signal of the detection signal as a result of the frequency analysis.

[0030] The noise level estimation unit 203 estimates the noise level of the detection signal using the result of the frequency analysis.

[0031] The fundamental frequency estimation unit 204 estimates the fundamental frequency of the heartbeat. The fundamental frequency of the heartbeat is roughly the reciprocal of the average heartbeat interval, and is the frequency of a peak that appears around 1 Hz. The fundamental frequency estimation unit 204 determines whether the signal-to-noise ratio (hereinafter referred to as "SN ratio") of the detected signal in the expected cardiac fundamental frequency band is less than a second threshold value. Here, the assumed heart rate fundamental frequency band is a band in which the fundamental frequency is assumed to exist.

[0032] If the SNR of the detected signal in the expected fundamental frequency band is equal to or greater than the second threshold, the fundamental frequency estimation unit 204 determines that there is little noise in the expected fundamental frequency band or that the individual strength of the detected signal is high. Therefore, the fundamental frequency estimation unit 204 detects peaks in the detected signal in the expected fundamental frequency band and estimates the frequency of the peaks detected in the expected fundamental frequency band as the fundamental frequency.

[0033] If the SNR of the detection signal in the expected heart rate fundamental frequency band is less than the second threshold, the fundamental frequency estimation unit 204 determines that the noise in the expected fundamental frequency band is large or the strength of the detection signal is low. Therefore, the fundamental frequency estimation unit 204 detects peaks of the frequency domain signal of the detection signal in the expected heart rate harmonic band, and estimates the fundamental frequency based on the frequency of the peak detected in the expected heart rate harmonic band.

[0034] Here, the expected heart rate harmonic band is a band in which frequencies higher than the fundamental frequency are expected to exist. In this embodiment, the fundamental frequency estimation unit 204 detects peaks of the frequency domain signal of the detection signal in a band that is an integer multiple of the expected heart rate fundamental frequency band as the expected heart rate harmonic band, and estimates the fundamental frequency of the heart rate by back-calculating from the difference in frequency of the peaks detected in the expected heart rate harmonic band.

[0035] The filter processing unit 205 generates a filter based on the result of the frequency analysis by the frequency analysis unit 202, and applies the generated filter to the detection signal. Here, the filter processing unit 205 generates a band-pass filter as the filter, whose passbands are the fundamental frequency band and a predetermined range of bands in the harmonic band. Here, the fundamental frequency band is a band of a predetermined width based on the fundamental frequency estimated by the fundamental frequency estimation unit 204. The harmonic band is a band of frequencies higher than the fundamental frequency band.

[0036] Specifically, the filter processing unit 205 calculates the SN ratio of the detection signal for each fundamental frequency band and harmonic band, and generates a band-pass filter that passes only bands where the SN ratio is equal to or greater than a predetermined first threshold.

[0037] The peak detection unit 206 detects biological information, which is the interval between heartbeats, based on the detection signal before application of the bandpass filter (hereinafter referred to as "before application of the filter") corresponding to the peak of the detection signal after application of the bandpass filter (hereinafter referred to as "after application of the filter"). That is, for each peak in the detection signal after application of the filter, the peak of the detection signal before application of the filter is obtained. Then, the peak detection unit 206 detects the arrangement of peaks in the detection signal based on the peaks in the detection signal after application of the bandpass filter and the peaks of the detection signal before application of the filter.

[0038] Specifically, for each peak (first peak) in the detection signal after application of the filter, the peak detection unit 206 detects the arrangement of peaks in the detection signal as biological information according to the respective positions of the peak (second peak) immediately before the time of the first peak in the peaks of the detection signal before application of the filter and the peak (third peak) immediately after the time of the first peak in the peaks of the detection signal before application of the filter.

[0039] The peak correction unit 207 corrects the position of the peak of the detection signal when the peak of the detection signal is within a predetermined range of outliers.

[0040] The output unit 208 outputs the heartbeat interval based on the peak of the corrected detection signal as biological information to the vehicle control system 112.

[0041] Next, a biological information detection process performed by the biological information detection device 111 of this embodiment will be described. FIG. 5 is a flowchart illustrating an example of a procedure for biological information detection processing according to the first embodiment.

[0042] First, the acquisition unit 201 acquires a detection signal from the air pressure sensor 12 (S101). Next, the frequency analysis unit 102 performs frequency analysis on the acquired detection signal (S102). As a result, a frequency domain signal of the detection signal is obtained. Next, the noise level estimation unit 203 estimates the noise level of the detection signal (S103). Specifically, in order to calculate the S / N ratio, the noise level estimation unit 203 estimates a noise approximation line by fitting noise to a curve of the frequency domain signal of the detection signal.

[0043] Fig. 6 is a diagram showing an example of the waveform of a frequency domain signal that is a result of frequency analysis according to the first embodiment, in which the horizontal axis represents frequency and the vertical axis represents the intensity of the detection signal.

[0044] The waveforms indicated by the solid line and the dashed-dotted line are the frequency domain signal of the detection signal. Here, the waveform indicated by the dashed-dotted line is the noise waveform. The waveform indicated by the solid line is the waveform of the detection signal. In Fig. 6, the dotted line is the noise approximation line indicating the noise level estimated by noise level estimation unit 203.

[0045] Returning to FIG. 5, next, the fundamental frequency estimation unit 204 executes a fundamental frequency estimation process to estimate the fundamental frequency of the heartbeat (S104).

[0046] FIG. 7 is a flowchart showing an example of a procedure of a fundamental frequency estimation process according to the first embodiment.

[0047] First, the fundamental frequency estimation unit 204 obtains the S / N ratio of the detection signal in the above-mentioned expected cardiac fundamental frequency band, and determines whether the S / N ratio is equal to or greater than a second threshold (S201). Here, the fundamental frequency estimation unit 204 calculates the S / N ratio from the signal strength (i.e., amplitude) in the expected cardiac fundamental frequency band, using the portion indicated by reference numeral 702 on the noise approximation line shown in Fig. 6 as the noise level.

[0048] If the SNR of the detection signal in the expected heartbeat fundamental frequency band is equal to or greater than the second threshold (S201: Yes), the signal strength relative to noise is sufficient, and the fundamental frequency estimation unit 204 determines that it is possible to estimate the fundamental frequency directly from the expected heartbeat fundamental frequency band. Therefore, the fundamental frequency estimation unit 204 detects peaks of the frequency domain signal of the detection signal in the expected heartbeat fundamental frequency band (S202). The fundamental frequency estimation unit 204 then sets the frequency of the maximum peak among the peaks detected in the expected heartbeat fundamental frequency band as the fundamental frequency (S203). In the example of FIG. 6, the fundamental frequency estimation unit 204 determines that the peak indicated by the star mark is the maximum and sets it as the fundamental frequency.

[0049] On the other hand, if the SNR of the detection signal in the expected heartbeat fundamental frequency band is less than the second threshold in S201 (S201: No), the signal strength relative to noise is insufficient, making it difficult for the fundamental frequency estimation unit 204 to directly estimate the fundamental frequency from the expected heartbeat fundamental frequency band. For example, this is the case when the noise level is high. For this reason, the fundamental frequency estimation unit 204 does not directly detect the fundamental frequency from the expected heartbeat fundamental frequency band, but estimates the fundamental frequency from the peak of the frequency domain signal of the detection signal in the expected heartbeat harmonic region.

[0050] In this embodiment, the fundamental frequency estimation unit 204 detects the peak of the frequency domain signal of the detection signal in a band that is an integer multiple of the expected heart rate fundamental frequency band as the expected heart rate harmonic band. Specifically, the fundamental frequency estimation unit 204 calculates the autocorrelation coefficient by multiplying the signal strength by a window function that amplifies the higher frequencies (S204).

[0051] The fundamental frequency estimation unit 204 then detects a peak based on the autocorrelation coefficient in a band outside the expected fundamental frequency band (S205). Specifically, the fundamental frequency estimation unit 204 calculates the autocorrelation coefficient with the signal before the movement while shifting the frequency domain signal of the detection signal toward the higher frequency side along the frequency axis, and determines that the state where the autocorrelation coefficient is the highest value is a state where the peaks of the signals before and after the movement overlap. The fundamental frequency estimation unit 204 then sets the amount of shift along the frequency axis determined based on the autocorrelation coefficient as the fundamental frequency (S206).

[0052] For example, the fundamental frequency estimation unit 204 calculates the autocorrelation coefficient for a signal in an expected heart rate harmonic band that is twice the expected heart rate fundamental frequency band, while shifting the signal toward the expected heart rate harmonic band that is three times the expected heart rate fundamental frequency band.The fundamental frequency estimation unit 204 then determines that the point where the autocorrelation coefficient is maximum is the point that coincides with a peak in the expected heart rate harmonic band that is three times the expected heart rate fundamental frequency band.The sliding width at this time (e.g., a bandwidth of 1.2 Hz) is the width between the peak in the expected heart rate harmonic band that is twice the expected heart rate harmonic band and the peak in the expected heart rate harmonic band that is three times the expected heart rate fundamental frequency band.Therefore, the fundamental frequency estimation unit 204 estimates that the frequency corresponding to this width from the peak in the expected heart rate harmonic band that is twice the expected heart rate fundamental frequency band is the fundamental frequency of the heart rate.

[0053] Once the fundamental frequency of the heartbeat has been estimated as described above, the fundamental frequency estimation unit 204 sets a band of a predetermined width as the fundamental frequency band based on this fundamental frequency, and also sets a band of a predetermined width on the harmonic side that is an integer multiple of the fundamental frequency band 601 as the harmonic band. The example in Fig. 6 shows an example in which the fundamental frequency band 601, the harmonic band 602 that is twice the fundamental frequency band 601, and the harmonic band 603 that is three times the fundamental frequency band 601 are set.

[0054] Then, the process returns to the caller.

[0055] Returning to FIG. 5, when the fundamental frequency estimation process (S104) is completed, the filter processing unit 205 executes a filter process to generate a band-pass filter and apply it to the detection signal (S105). FIG. 8 is a flowchart showing an example of a procedure for the filtering process according to the first embodiment.

[0056] First, based on the fundamental frequency, filter processing unit 205 extracts a harmonic band below frequency f according to the frequency response characteristics of air pressure sensor 12 (S301). Harmonic response varies depending on the frequency response characteristics of the sensor. For this reason, in the case of an air pressure sensor 12 with high response, filter processing unit 205 extracts a harmonic band below a band five times the fundamental frequency, for example, and in the case of an air pressure sensor 12 with low response, filter processing unit 205 extracts a harmonic band below a band three times the fundamental frequency, for example.

[0057] Next, the filter processing unit 205 calculates the S / N ratio of the detection signal for each of the fundamental frequency band and the harmonic band (S302). In the example of Fig. 6, the filter processing unit 205 calculates the S / N ratio using the noise level indicated by symbol 702 on the noise approximation line in the fundamental frequency band, the noise level indicated by symbol 703 on the noise approximation line in the harmonic band 602 that is twice the fundamental frequency band, and the noise level indicated by symbol 704 on the noise approximation line in the harmonic band 603 that is three times the fundamental frequency band.

[0058] Next, the filter processing unit 205 generates a band-pass filter that has, as its passband, only bands where the S / N ratio is equal to or greater than the first threshold from among the fundamental frequency band and harmonic bands (S303). In the example of Fig. 6, the filter processing unit 205 extracts, as harmonic bands, a band 602 that is twice the fundamental frequency band 601 and a band 603 that is three times the fundamental frequency band, but does not extract the four times the fundamental frequency band (around 5 Hz).

[0059] The filter processing unit 205 then applies the generated band-pass filter to the detection signal, thereby extracting the detection signal only in the pass band, and the process then returns to the caller.

[0060] Returning to FIG. 5, once the filtering process (S105) is completed, the peak detecting unit 206 executes peak detection process to detect peaks in the detection signal (S106). FIG. 9 is a flowchart illustrating an example of a procedure for peak detection processing according to the first embodiment.

[0061] Fig. 10 is a diagram showing a comparison of the detection signal before and after application of the filter according to the first embodiment. In Fig. 10, the horizontal axis represents time, and the vertical axis represents intensity. In Fig. 10, the solid line graph on the upper side represents the detection signal and peak positions before application of the filter. The dashed-dotted line graph on the lower side represents the detection signal and peak positions after application of the filter. Here, the peak positions in both waveforms are indicated by inverted triangle marks.

[0062] First, the peak detection unit 206 detects the peak times of the filtered detection signal (S401). As shown in Fig. 10, the array of the detected peaks (first peaks) of the filtered detection signal is defined as array A.

[0063] Next, the peak detection unit 206 detects the peak times of the detection signal before application of the filter (S402). The array of the detected peaks of the detection signal before application of the filter is referred to as array B, as shown in FIG.

[0064] Next, the peak detection unit 206 extracts peaks (second peaks) that are elements of array B that are located immediately before the time of each element of array A of the peak of the detection signal after application of the filter (S403). As shown in FIG. 10, the extracted element of array B is designated as C.

[0065] Next, the peak detection unit 206 extracts a peak (third peak) that is an element of array B immediately after the time of each element of array A of the peak of the detection signal after application of the filter (S404). As shown in FIG. 10, the extracted element of array B is designated as D.

[0066] Next, the peak detection unit 206 calculates the value X for each element of the arrays A, C, and D using the following equation (1), and further calculates the average value d of the values ​​X calculated for each element (S405).

[0067] X=abs((AC) / (DC)-0.5) (1)

[0068] Here, X is a value indicating the degree of deviation from the center of the peak times (in the detection signal before application of the filter) immediately before and after the peak time after application of the filter.

[0069] That is, for each peak (first peak) in the detection signal after application of the filter, if the position of the first peak is away from the center position of the interval between the second peak and the third peak by more than a predetermined distance, the peak detection unit 206 determines the peak of the detection signal that is closest to the first peak among the second peak and the third peak, and detects it as an array of peaks in the detection signal.

[0070] Furthermore, when the position of the first peak is within a predetermined distance from the center position of the interval between the second peak and the third peak, the peak detection unit 206 detects the arrangement of the peaks of the detection signal, regarding the second peak as the peak of the detection signal.

[0071] Specifically, the following processing is performed. The peak detection unit 206 determines whether the average value d of X is greater than a first threshold value as a predetermined distance, i.e., whether the second peak and the third peak are far from the center (S406). If the average value d is greater than the first threshold value (S406: Yes), this means that the second peak and the third peak are far from the center. Therefore, the peak detection unit 206 extracts the element of array B (i.e., the peak of the detection signal after application of the filter) that is closest to the element of array A (i.e., each peak time of the detection signal after application of the filter), and detects the extracted element as the peak array of the detection signal (S407).

[0072] On the other hand, if the average value d is smaller than the first threshold value (S406: No), this means that the second and third peaks are not far from the center. Therefore, the peak detection unit 206 detects array C (i.e., the elements of array B immediately preceding the positions of the filtered detection signal corresponding to each element of array A) as the peak array of the detection signal (S408). In this way, the peak detector 206 detects the peak sequence of the detection signal, and then the process returns to the caller.

[0073] Returning to FIG. 5, when the peak detection process (S106) is completed, the peak correction unit 207 executes peak correction process (S107) to correct the peak of the detection signal detected in S106. FIG. 11 is a flowchart illustrating an example of a procedure for the peak correction process according to the first embodiment.

[0074] First, the peak correction unit 207 calculates the difference (i.e., interval) between each element of the array of peaks of the detection signal and the previous element (S501). The interval between each element is called a heartbeat interval array.

[0075] Next, the peak correction unit 207 detects whether there is an outlier in the heartbeat interval array obtained in S501, and stores the index of the element determined to be an outlier and whether the element of the index determined to be an outlier is on the upper or lower side in the array (S502).

[0076] Here, an example of an upper outlier is one that exceeds the mean value + standard deviation * n (n is an integer). An example of a lower outlier is one that falls below the mean value - standard deviation * n (n is an integer). However, these are just examples and are not limiting.

[0077] Next, the peak correction unit 207 initializes a counter i to 1 (S503). Next, it is determined whether the value of counter i is less than the number of outliers detected in S502 (S504).

[0078] If the value of counter i is less than the number of outliers (S504: Yes), the peak correction unit 207 determines whether the difference between the i-th and (i+1)-th indexes of the outlier elements is less than a predetermined threshold (S505).If the difference between the i-th and (i+1)-th indexes of the outlier elements is equal to or greater than the predetermined threshold (S505: No), the peak correction unit 207 increments counter i (S511), and the process returns to S504, where it repeats the process from S504.

[0079] On the other hand, if the difference between the i-th and (i+1)-th indexes of the outlier elements is less than the predetermined threshold in S505 (S505: Yes), the peak correction unit 207 determines whether the i-th index element is an upper outlier and the (i+1)-th index element is a lower outlier (S506).

[0080] If the i-th index element is an upper outlier and the (i+1)-th index element is a lower outlier (S506: Yes), this means that the interval between the i-th index element and the (i+1)-th index element is narrowing. Therefore, the peak correction unit 207 changes the elements of the peak array of the detection signal from the i-th index element to the (i+1)-th index element (index -1) to the peak at the previous time in array B (the peak array before application of the filter) (S507). The peak correction unit 207 then increments counter i (S508). Next, the peak correction unit 207 further increments counter i (S511), and the process returns to S504, where the process is repeated from S504.

[0081] In S506, if the i-th element of the index is not an upper outlier or the i+1-th element of the index is not a lower outlier (S506: No), the peak correction unit 207 determines whether the i-th outlier is on the lower side and the i+1-th outlier is on the upper side (S509).

[0082] If the i-th outlier is not on the lower side or the i+1-th outlier is not on the upper side (S509: No), the peak correction unit 207 increments the counter i (S511), and the process returns to S504, and the process is repeated from S504.

[0083] If the i-th outlier is on the lower side and the i+1-th outlier is on the upper side in S509 (S509: Yes), this means that the interval between the i-th index element and the i+1-th index element is widening. Therefore, the peak correction unit 207 changes the elements of the peak array of the detection signal from the i-th index element to the i+1-th index element (index -1) to the peak at the next later time in array B (the peak array before application of the filter) (S510). The peak correction unit 207 then increments counter i (S508). Next, the peak correction unit 207 further increments counter i (S511), and the process returns to S504, where the process is repeated from S504.

[0084] In S504, if the value of counter i is equal to or greater than the number of outliers (S504: No), the process returns to the caller.

[0085] Returning to FIG. 5, when the peak correction process (S107) is completed, the output unit 208 outputs the heartbeat interval based on the peak of the detection signal to the vehicle control system 112 as biological information (S108).

[0086] As described above, the biometric information detection device 111 according to this embodiment includes an air pressure sensor 12 that detects information relating to a person's body movements, a frequency analysis unit 202 that performs frequency analysis on the detection signal of the information relating to the body movements detected by the air pressure sensor 12, a filter processing unit 205 that generates a filter based on the results of the frequency analysis and applies the generated filter to the detection signal, and a peak detection unit 206 that detects biometric information, which is the interval between heartbeats, based on the detection signal before application of the filter that corresponds to the peak of the detection signal after application of the filter.

[0087] Therefore, according to this embodiment, biological information, which is the heartbeat interval, is detected using raw data, i.e., the unfiltered detection signal corresponding to the peak of the filtered signal, rather than the filtered signal of the detection signal related to body movement, so that biological information can be detected with high accuracy. Therefore, according to this embodiment, since only the air pressure sensor 12 is used to detect the detection signal, the device configuration is simplified compared to when multiple sensors are used, and the manufacturing costs of the device can be reduced.

[0088] In addition, the biological information detection device 111 according to this embodiment further includes a fundamental frequency estimation unit 204 that estimates the fundamental frequency of the body movement, and a filter processing unit 205 generates a filter whose passbands are a fundamental frequency band, which is a band based on the estimated fundamental frequency, and a predetermined range of bands in the harmonic band, which is a band of frequencies higher than the fundamental frequency band, and applies the generated filter to the detection signal.

[0089] Therefore, according to this embodiment, by applying a filter, the frequency related to the detection signal can be easily extracted, and the frequency adjusted by the filter can be extracted, so that biometric information can be detected with higher accuracy.

[0090] In addition, in the biometric information detection device 111 according to this embodiment, the filter processing unit 205 calculates the SN ratio of the detection signal for each fundamental frequency band and harmonic band, and generates a filter whose passband is only the band in which the SN ratio is equal to or greater than the first threshold value.

[0091] Therefore, according to this embodiment, a filter is applied to the detection signal in the fundamental frequency band and the harmonic band, which has only bands with a high S / N ratio as its pass band, thereby suppressing waveform deterioration of the detection signal and thereby enabling biometric information to be detected with higher accuracy.

[0092] Furthermore, in the biometric information detection device 111 according to this embodiment, the filter processing unit 205 generates the filter having a passband that is the fundamental frequency band and a band among the harmonic bands that corresponds to the frequency response characteristics of the air pressure sensor 12.

[0093] Therefore, according to this embodiment, the accuracy of the detection signal after application of the filter is improved, and thus biological information can be detected with higher accuracy.

[0094] Furthermore, the biological information detection device 111 according to this embodiment includes a fundamental frequency estimation unit 204 that detects a peak of the frequency domain signal of the detection signal in an expected heart rate harmonic band, which is a band where frequencies higher than the fundamental frequency are expected to exist, when the SNR of the detection signal in an expected heart rate fundamental frequency band, which is a band where the fundamental frequency is expected to exist, is less than a second threshold value, and estimates the fundamental frequency based on the frequency of the peak detected in the expected heart rate harmonic band.

[0095] Therefore, according to this embodiment, even if the S / N ratio of the detection signal is low due to noise or the like in the expected fundamental heart rate frequency band, and the peaks are unclear and it is difficult to estimate the fundamental frequency, it is possible to estimate the fundamental frequency based on the peaks detected in the expected harmonic heart rate band. Therefore, according to this embodiment, even if the S / N ratio of the detection signal is low in the expected fundamental heart rate frequency band, it is possible to accurately estimate the fundamental frequency, and as a result, it is possible to detect biological information with higher accuracy.

[0096] Furthermore, in the biological information detection device 111 according to this embodiment, the fundamental frequency estimation unit 204 detects peaks of the frequency domain signal of the detection signal in a band that is an integer multiple of the expected heart rate fundamental frequency band as the expected heart rate harmonic band, and estimates the fundamental frequency by back-calculating from the difference in frequency of the peaks detected in the expected heart rate harmonic band.

[0097] Therefore, according to this embodiment, even if the S / N ratio of the detection signal is low due to noise or the like in the expected heart rate fundamental frequency band, and the peaks are unclear and it is difficult to estimate the fundamental frequency, the fundamental frequency is estimated by back-calculating from the difference in the frequencies of the peaks detected in expected heart rate harmonic bands that are integer multiples of the expected heart rate fundamental frequency band, thereby improving robustness and enabling accurate and easy estimation of the fundamental frequency. Therefore, according to this embodiment, even if the S / N ratio of the detection signal is low in the expected heart rate fundamental frequency band, the fundamental frequency can be accurately and easily estimated, and as a result, biological information can be detected with higher precision.

[0098] Furthermore, in the biometric information detection device 111 according to this embodiment, the peak detection unit 206 detects the arrangement of peaks in the detection signal as biometric information, depending on the respective positions of the second peak, which is the peak immediately before the time of the first peak in the detection signal before the application of the filter, and the third peak, which is the peak immediately after the time of the first peak in the detection signal before the application of the filter, for each first peak in the detection signal after the application of the filter.

[0099] Therefore, according to this embodiment, for the first peak in the detection signal after application of the filter, the arrangement of peaks in the detection signal is detected as biometric information using the second peak immediately before the time of the first peak and the third peak immediately after the time of the first peak, so that the biometric information, which is the interval between heartbeats, can be detected with higher accuracy.

[0100] Furthermore, in the biometric information detection device 111 according to this embodiment, when the position of each first peak is away from the center position of the interval between the second peak and the third peak by more than a predetermined distance, the peak detection unit 206 determines the peak of the second peak and the third peak that is closest to the first peak as the peak of the detection signal, and detects the arrangement of the peaks of the detection signal as the biometric information.

[0101] Therefore, according to this embodiment, when the position of the first peak is away from the center position of the interval between the second peak and the third peak by a predetermined distance, the peak of the second peak and the third peak that is closest to the first peak is set as the peak of the detection signal, thereby making it possible to detect biological information, which is the interval between heartbeats, with higher accuracy.

[0102] Furthermore, in the biological information detection device 111 according to this embodiment, the peak detection unit 206 further determines the second peak as the peak of the detection signal when the position of the first peak is within a predetermined distance from the center position of the interval between the second peak and the third peak, and detects the arrangement of the peaks of the detection signal as the biological information. Therefore, according to this embodiment, by determining the second peak as the peak of the detection signal when the position of the first peak is within a predetermined distance from the center position of the interval between the second peak and the third peak, it is possible to detect the biological information, which is the interval between heartbeats, with higher accuracy.

[0103] Moreover, the biological information detection device 111 according to this embodiment further includes a peak correction unit 207 that corrects the position of the peak of the detection signal when the peak of the detection signal is within a predetermined outlier range. Therefore, according to this embodiment, even if the peak of the detection signal detected by the peak detection unit 206 is erroneous, the correction can be used to detect biological information, which is the interval between heartbeats, with higher accuracy.

[0104] Furthermore, in the biological information detection device 111 according to this embodiment, the air pressure sensor 12 detects information related to a person's heartbeat as information related to the person's body movement. Therefore, according to this embodiment, a signal related to the heartbeat is detected as the body movement and various processes are performed, so that biological information, which is the interval between heartbeats, can be detected with higher accuracy.

[0105] Furthermore, in the biological information detecting device 111 according to this embodiment, the air pressure sensor 12 detects information about the heartbeat from changes in air pressure in an air bag that can press against a person while the person is seated. Therefore, according to this embodiment, information about the heartbeat is detected using existing parts, which simplifies the device structure and reduces the manufacturing costs of the device.

[0106] (Variation) In the above embodiment, the peak detection unit 206 detects the arrangement of peaks in the detection signal using all peaks in the detection signal after application of the filter, but this is not limiting. For example, the peak detection unit 206 can be configured to detect the arrangement of peaks in the detection signal while ignoring peaks that deviate from the fundamental frequency among the peaks in the detection signal after application of the filter.

[0107] In this case, by ignoring peaks that deviate from the fundamental frequency, it is possible to detect biological information, which is the interval between heartbeats, with higher accuracy.

[0108] (Second embodiment) In the first embodiment and its modified example, a person's body movement is detected and heartbeat intervals based on the peaks of the detection signal are detected as biometric information, but the person's breathing is not taken into consideration. In this second embodiment, the person's breathing is taken into consideration and heartbeat intervals based on the peaks of the detection signal are detected as biometric information.

[0109] The configuration of the vehicle 1, the configuration of the biological information detection system 100, and the configuration of the biological information detection device 111 in the second embodiment are the same as those in the first embodiment.

[0110] The fundamental frequency estimation unit 204 of the biological information detection device 111 according to this embodiment has the same functions as those of the first embodiment, and in addition detects respiratory body movement information from the frequency domain signal of the detection signal, and estimates the fundamental frequency of the heartbeat based on the detected respiratory body movement information and the frequency of the peak detected in the expected heartbeat fundamental frequency band or the expected heartbeat harmonic band.

[0111] Next, the biological information detection process according to this embodiment will be described. 12 is a flowchart showing an example of the procedure of the biological information detection process according to the second embodiment. The processes (S101 to S103) from input of the detection signal from the air pressure sensor 12 to noise level estimation are performed in the same manner as in the first embodiment.

[0112] In this embodiment, the following processing is executed in parallel with or before this. That is, when the occupant is in a resting state, the acquisition unit 201 inputs a detection signal from the air pressure sensor 12 (S601). Next, the fundamental frequency estimation unit 204 acquires the fundamental frequency of breathing from the HF band (0.04 to 0.15 Hz) in the frequency domain (S602).

[0113] Next, the fundamental frequency estimation unit 204 executes a fundamental frequency estimation process (S603). FIG. 13 is a flowchart illustrating an example of a procedure for a fundamental frequency estimation process according to the second embodiment.

[0114] As in the first embodiment, the fundamental frequency estimation unit 204 determines whether the S / N ratio of the detection signal in the expected heartbeat fundamental frequency band is equal to or greater than a second threshold (S201). If the S / N ratio is less than the second threshold (S201: No), as in the first embodiment, the fundamental frequency estimation unit 204 calculates autocorrelation coefficients (S204) and detects peaks outside the expected heartbeat fundamental frequency band based on the autocorrelation coefficients (S205). Then, as in the first embodiment, the fundamental frequency estimation unit 204 sets the amount of movement in the frequency axis direction determined based on the autocorrelation coefficients as a candidate for the heartbeat fundamental frequency (S706). Then, the process proceeds to S702.

[0115] In S201, if the S / N ratio of the detected signal in the expected heartbeat fundamental frequency band is equal to or greater than the second threshold (S201: No), the fundamental frequency estimation unit 204 detects peaks in the expected heartbeat fundamental frequency band (S202), as in the first embodiment. Next, the fundamental frequency estimation unit 204 extracts the frequency at which the maximum peak occurs as a candidate for the heartbeat fundamental frequency (S701).

[0116] Next, in S702, the fundamental frequency estimation unit 204 compares the candidate fundamental frequency of heartbeat with the fundamental frequency of respiration and the respiratory harmonics for the fundamental frequency of respiration set in S205 (S702). Specifically, if the fundamental frequency and the respiratory harmonics for the fundamental frequency of respiration are represented by Xn (n is an integer), then the fundamental frequency estimation unit 204 determines whether the fundamental frequency of respiration and the respiratory harmonics overlap with the candidate fundamental frequency of heartbeat (S703). Specifically, the fundamental frequency estimation unit 204 compares each of the fundamental frequency of respiration and the respiratory harmonics with the candidate fundamental frequency of heartbeat while increasing n, and determines whether they overlap.

[0117] If the fundamental frequency and respiratory harmonics of breathing do not overlap with the candidate fundamental frequency of the heartbeat (S703: No), the fundamental frequency estimation unit 204 sets the detected candidate fundamental frequency as the fundamental frequency of the heartbeat (S704), and then the process returns to the caller.

[0118] On the other hand, if the fundamental frequency of breathing and respiratory harmonics overlap with the candidates for the fundamental frequency of heartbeats (S703: Yes), the fundamental frequency estimation unit 204 estimates the frequency of the peak that is next to the largest peak among the detected candidates for fundamental frequency as the fundamental frequency of heartbeats (S705).The process then returns to S703, and the process from S703 is repeatedly executed while increasing n.As a result, the frequency of a peak that does not overlap with the fundamental frequency of breathing and respiratory harmonics is detected from the expected fundamental frequency band of heartbeats, and is estimated as the fundamental frequency of heartbeats.

[0119] Returning to FIG. 12, once the fundamental frequency estimation process (S604) is completed, the filtering process to the bioinformation output process (S105 to S108) are executed in the same manner as in the first embodiment.

[0120] As described above, in the biological information detection device 11 according to this embodiment, the fundamental frequency estimation unit 204 detects breathing-induced body movement as respiratory body movement information from the frequency domain signal of the detection signal, and estimates the fundamental frequency of the heartbeat based on the detected respiratory body movement information and the frequency of the peak detected in the expected heartbeat fundamental frequency band or the expected heartbeat harmonic band. Therefore, in this embodiment, the fundamental frequency of the heartbeat is estimated taking the breathing frequency into consideration, so that the fundamental frequency can be estimated more accurately, and thus the biological information, which is the heartbeat interval, can be detected with higher accuracy.

[0121] Furthermore, in the biological information detection device 11 according to this embodiment, the fundamental frequency estimation unit 204 detects the fundamental frequency of breathing as respiratory body movement information, determines whether the detected fundamental frequency of breathing and respiratory harmonics of the fundamental frequency of breathing overlap with the frequency of a peak detected in the expected fundamental heartbeat frequency band, and if they do not overlap, estimates the frequency of the peak detected in the expected fundamental heartbeat frequency band or the expected fundamental heartbeat frequency band as the fundamental frequency of the detection signal. If they overlap, detects the frequency of a peak that does not overlap with the fundamental frequency of breathing and respiratory harmonics from the expected fundamental heartbeat frequency band and estimates it as the fundamental frequency of the body movement. Therefore, according to this embodiment, the fundamental frequency of heartbeats is estimated after removing the frequency of breathing, thereby enabling more accurate estimation of the fundamental frequency of heartbeats, and thereby enabling more accurate detection of biological information, which is the interval between heartbeats.

[0122] In the above embodiment, the biometric information detection device 111 detects the biometric information of occupants such as the driver 2 of the vehicle 1, but the detection target is not limited to the occupants of the vehicle 1, and any device that detects human biometric information may be used.

[0123] The program for causing a computer (such as the processor 121) to realize the functions of the biometric information detection device 111 of the above-described embodiment and modified example may be configured to be provided by being recorded in an installable or executable file format on a computer-readable recording medium such as a CD-ROM, a flexible disk (FD), a CD-R, or a DVD (Digital Versatile Disk).

[0124] The program may also be configured to be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network, or may be configured to be provided or distributed via a network such as the Internet.

[0125] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0126] 1...vehicle, 12...air pressure sensor, 100...biometric information detection system, 111...biometric information detection device, 112...vehicle control system, 201...acquisition unit, 202...frequency analysis unit, 203...noise level estimation unit, 204...fundamental frequency estimation unit (estimation unit), 205...filter processing unit, 206...peak detection unit (detection unit), 207...peak correction unit (correction unit), 208...output unit.

Claims

1. a sensor for detecting information about a person's body movement; a frequency analysis unit that performs frequency analysis on a detection signal of information regarding the body movement detected by the sensor; a filter processing unit that generates a filter based on a result of the frequency analysis and applies the generated filter to the detection signal; a detection unit that detects biological information, which is an interval between heartbeats, based on the detection signal before application of the filter that corresponds to a peak of the detection signal after application of the filter; A biological information detection device comprising:

2. An estimation unit that estimates a fundamental frequency of the body movement, the filter processing unit generates the filter having passbands including a fundamental frequency band, which is a band based on the estimated fundamental frequency, and a predetermined range of bands in a harmonic band, which is a band of frequencies higher than the fundamental frequency band, and applies the generated filter to the detection signal. The biological information detection device according to claim 1 .

3. the filter processing unit calculates a signal-to-noise ratio of the detection signal for each of the fundamental frequency band and the harmonic band, and generates the filter having only a band in which the signal-to-noise ratio is equal to or greater than a first threshold as the passband. The biological information detection device according to claim 2 .

4. the filter processing unit generates the filter having passbands including the fundamental frequency band and a band among the harmonic bands that corresponds to the frequency response characteristics of the sensor. The biological information detection device according to claim 2 .

5. the estimation unit detects a peak of a frequency domain signal of the detection signal in an expected heart rate harmonic band, which is a band in which frequencies higher than the fundamental frequency are expected to exist, when a signal-to-noise ratio of the detection signal in an expected heart rate fundamental frequency band, which is a band in which the fundamental frequency is expected to exist, is less than a second threshold, and estimates the fundamental frequency based on the frequency of the peak detected in the expected heart rate harmonic band. The biological information detection device according to claim 2 , further comprising:

6. the estimation unit detects peaks of a frequency domain signal of the detection signal in a band that is an integer multiple of the expected heart rate fundamental frequency band as the expected heart rate harmonic band, and estimates the fundamental frequency by performing a back calculation from a difference in frequency of the peaks detected in the expected heart rate harmonic band. The biological information detecting device according to claim 5 .

7. the estimation unit detects body movement due to breathing as respiratory body movement information from a frequency domain signal of the detection signal, and estimates a fundamental frequency of the body movement based on the detected respiratory body movement information and a frequency of a peak detected in the expected heart rate fundamental frequency band or the expected heart rate harmonic band. The biological information detecting device according to claim 5 .

8. the estimation unit detects a fundamental frequency of breathing as the respiratory body movement information, determines whether the detected fundamental frequency of breathing and respiratory harmonics of the fundamental frequency of breathing overlap with the frequency of a peak detected in the assumed fundamental heartbeat frequency band, and if they do not overlap, estimates the frequency of the peak detected in the assumed fundamental heartbeat frequency band as the fundamental frequency of the detection signal, and if they overlap, detects a frequency of a peak that does not overlap with the fundamental frequency of breathing and respiratory harmonics from the assumed fundamental heartbeat frequency band, and estimates it as the fundamental frequency of the body movement. The biological information detection device according to claim 7 .

9. the detection unit detects, for each first peak in the detection signal after application of the filter, an arrangement of peaks in the detection signal as the biological information, according to positions of a second peak in the detection signal before application of the filter, the second peak being a peak immediately before the time of the first peak, and a third peak in the detection signal before application of the filter being a peak immediately after the time of the first peak. The biological information detection device according to claim 2 .

10. When the position of each of the first peaks is away from a center position of an interval between the second peak and the third peak by a predetermined distance, the detection unit determines the peak closest to the first peak among the second peak and the third peak as the peak of the detection signal, and detects an arrangement of the peaks of the detection signal as the biological information. The biological information detection device according to claim 9 .

11. the detection unit further detects, when a position of the first peak is within the predetermined distance from a center position of an interval between the second peak and the third peak, the second peak as a peak of the detection signal, and detects an arrangement of the peaks of the detection signal as the biological information. The biological information detection device according to claim 10.

12. the detection unit ignores peaks in the detection signal after application of the filter that deviate from the fundamental frequency. The biological information detection device according to claim 9 .

13. a correction unit that corrects the position of the peak of the detection signal when the peak of the detection signal is within a predetermined range of outliers; The biological information detection device according to claim 1 , further comprising:

14. the sensor detects information about the person's heartbeat as information about the person's body movement; The biological information detection device according to claim 1 .

15. the sensor detects information about the heartbeat based on a change in air pressure in an air bag that can press against the person while the person is seated. The biological information detection device according to claim 14.

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