JP7363268B2 - Biometric information acquisition device, biometric information acquisition method, and program - Google Patents

Description

The present invention relates to a biological information acquisition device, a biological information acquisition method, and a program.

BACKGROUND ART Systems have been developed that acquire biological information such as heart rate interval (RRI) to determine health conditions and sleep conditions. Normally, in order to obtain biological information related to heartbeats such as heartbeat intervals, it is necessary to obtain an electrocardiogram, but this requires electrodes to be attached to the subject's body and the subject to carry a measuring device. , it is difficult to easily obtain an electrocardiogram. On the other hand, as a device that acquires biological information such as heart rate without acquiring an electrocardiogram, for example, Patent Document 1 describes a device that uses a waveform with a clear amplitude corresponding to the R wave of an electrocardiogram among a plurality of vibration sensors. A biological information acquisition device is disclosed that selects a vibration sensor that is outputting and calculates fluctuations in the heart rate or beat interval of a subject based on the output signal of the selected vibration sensor.

Japanese Patent Application Publication No. 2015-66337

However, since a waveform with a clear amplitude does not necessarily correspond to an R wave, conventional devices such as the one disclosed in Patent Document 1 are unable to detect biological phenomena such as fluctuations in the subject's heart rate or beat intervals. There is a possibility that information cannot be detected appropriately.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a biological information acquisition device, a biological information acquisition method, and a program that can appropriately acquire biological information of a subject.

In order to achieve the above object, the biological information acquisition device according to the present invention includes:
Acquisition means for acquiring a plurality of sets of biological information of the same type of the target from each of a plurality of mutually different parts of the target in a first period;
Detection means for detecting a heartbeat interval in the biological information by detecting one peak at each predetermined detection time interval shorter than the first period;
An outlier level parameter is derived from each of the plurality of sets of biological information , using the heartbeat interval and a predetermined threshold, to derive an outlier degree parameter representing the extent to which the outlier is included in the first period in the biological information. a degree deriving means;
Selection means for selecting the biological information having the smaller outlier degree parameter from among the biological information of the same type acquired from each of the plurality of different parts;
Equipped with

According to the present invention, it becomes possible to appropriately acquire biological information of a subject.

FIG. 1 is a diagram illustrating a configuration example of a biological information acquisition device according to a first embodiment. FIG. 3 is a diagram showing the positional relationship between a lying subject and a tube provided in a sensor unit. FIG. 3 is a diagram showing an example of a data string of a ballistocardial signal. It is a figure showing an example of acquired BBI. FIG. 7 is a diagram showing an example of an outlier rate in a first period including the timing of interest, which is calculated while moving the timing of interest on the time axis. 3 is a flowchart of biological information acquisition processing according to the first embodiment. FIG. 3 is a diagram illustrating an example of BBI after outliers have been removed. 7 is a flowchart of outlier estimation processing according to the first embodiment. It is a flowchart of biometric information acquisition processing concerning a 2nd embodiment.

Embodiments will be described below with reference to the drawings. In addition, the same reference numerals are given to the same or corresponding parts in the figures.

(First embodiment)
The biological information acquisition device 100 according to the first embodiment is a device that acquires heartbeat intervals of a subject as biological information from a ballistocardiogram (BCG) waveform. As shown in FIG. 1, the biological information acquisition device 100 includes a control section 10, a storage section 20, a sensor section 30, an input section 41, an output section 42, and a communication section 43 as functional configurations. .

The control unit 10 is composed of a CPU (Central Processing Unit), etc., and realizes the functions of each unit (obtaining unit 11, calculating unit 12, selecting unit 13) described later by executing a program stored in the storage unit 20. do. Although not shown, the control unit 10 also has a function of measuring time using a timer (or clock) included in the CPU.

The storage unit 20 includes a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The ROM stores programs to be executed by the CPU of the control unit 10 and data necessary for executing the programs in advance. The RAM stores data that is created or changed during program execution.

The sensor unit 30 includes a plurality of sensors that detect vibrations of the body, and collects biological information (in this embodiment, a plurality of sets (as many as the number of sensors) of the same type from a plurality of different parts of a target (in this embodiment, a human being)). In this embodiment, a biological signal (in this embodiment, a ballistocardial signal) is detected to obtain a heartbeat interval. Specifically, as shown in FIG. 2, this sensor unit 30 includes three tubes (tube 31t, tube 32t, tube 33t) that are placed under the mattress 51 on which the subject sleeps, and each tube has a It is provided with three air pressure detection sensors (sensor 31s, sensor 32s, sensor 33s) that respectively detect the air pressure of . Then, when the subject is sleeping on the mattress 51, the sensors 31s, 32s, and 33s detect the air pressure in the corresponding tube, and the air pressure detected by each sensor is used as the ballistocardiogram of the subject. It can be acquired as a ballistocardial signal representing a waveform. This is because the air pressure detected by each sensor changes due to the vibration of the subject's body caused by the pulse of the subject's heart. Note that the tube is not limited to being placed under the mattress 51, but may be placed on top of the mattress 51 or inside the mattress 51.

In order to obtain ballistocardial signals, it is said that it is best to capture the body movement around the shoulder blade of the human subject 52, so these tubes 31t, 32t, and 33t are connected to It is placed in a position corresponding to the shoulder blade area when Although three of these tubes are installed in FIG. 2, four or more tubes may be installed, or two tubes may be installed. Furthermore, the device that captures body vibrations caused by the heartbeat of the subject 52 is not limited to the tube; instead of the tube, a piezoelectric element is installed under the mattress, and this piezoelectric element is connected to the sensor section 30. It may also be used as a sensor included in the system. Furthermore, the installation location of the sensor section 30 is not limited to the mattress, and the sensor section 30 may be installed on a chair or the like. For example, by installing the sensor unit 30 on a chair, the biological information acquisition device 100 can acquire ballistocardial signals when the subject 52 is sitting on the chair.

The input unit 41 includes, for example, a keyboard, a mouse, a touch panel, and the like. The input unit 41 is an interface for receiving user operations such as instructions to start/end acquisition of biological information such as heartbeat intervals.

The output unit 42 includes, for example, an LCD (Liquid Crystal Display), an EL (Electroluminescence) display, or the like. The output unit 42 displays, for example, biological information such as the heartbeat interval acquired by the biological information acquisition device 100.

The communication unit 43 is a communication interface that exchanges data and the like with other external devices. This communication interface may be wireless or wired. For example, the biometric information acquisition device 100 can transmit the acquired biometric information to an external server or the like via the communication unit 43.

Next, the functional configuration of the control unit 10 of the biological information acquisition device 100 will be explained. The control unit 10 realizes the functions of the acquisition unit 11, the calculation unit 12, and the selection unit 13, and acquires biological information.

The acquisition unit 11 acquires the air pressure as a ballistocardial signal based on the detection value (air pressure) detected by each of the plurality of sensors included in the sensor unit 30 and the detection time, and calculates the heartbeat interval from the acquired ballistocardial signal. A data string of BBI (Beat to Beat Interval) corresponding to BBI (Beat to Beat Interval) is acquired in time series. More specifically, the acquisition unit 11 samples ballistocardial signals output from each sensor included in the sensor unit 30 at a predetermined sampling frequency (for example, 100 Hz), and obtains ballistocardial signal data as shown in FIG. The BBI data string is obtained from the data string 200 of the ballistocardial signal. Note that the sampling frequency is not limited to 100 Hz, and may be any frequency as long as a ballistocardial signal can be obtained. Usually, a sampling frequency of about 80 to 100 Hz is used. The acquisition unit 11 functions as an acquisition means.

Any method can be used to obtain the BBI data string from the ballistocardial signal data string 200. For example, as described later, the beat timing is extracted by detecting the local maximum value (peak value detection) of the data string 200 of the ballistocardial signal using a window of a predetermined time width (for example, 1.2 seconds). , a method of acquiring the time interval between two beat timings that are adjacent to each other in time series as the BBI can be used. Note that the pulsation timing is the timing when a heartbeat occurs. In this embodiment, the time interval between two beat timings that are adjacent to each other on the time axis is estimated as the BBI that corresponds to the heartbeat interval. In this way, the beat timing can be estimated using the timer (or clock) of the CPU and the data string of the ballistocardial signal, but it can also be estimated using other appropriate methods such as pulse wave sampling. Good too. In addition, since BBI is a value representing the time interval between one beat and the next beat, it is called BBI by taking the initials of Beat to Beat Interval.

To explain this method in more detail, for example, the acquisition unit 11 moves the timing of interest on the time axis on the data string 200 of ballistocardial signals shown in FIG. (for example, 1.2 seconds), the peak value (local maximum value) in the time window centered on the timing of interest is detected, and the timing at which this peak value occurs is the corresponding one. If it matches the timing of interest, the timing of interest is extracted as the pulsation timing. In FIG. 3, paying attention to the point 202 representing the sampled ballistocardial signal, the point representing the peak value of the ballistocardial signal within the time window 200w is the point 202, so the ballistocardial signal represented by the point 202 The timing at which this occurs is extracted as the pulsation timing 202t. On the other hand, when focusing on point 312, for example, the point at which the peak value occurs within the time window 300w of the same time width is not point 312 but point 205. Therefore, the timing 312t of the point 312 is not extracted as the pulsation timing.

In this way, the acquisition unit 11 extracts the pulsation timings 201t, 202t, 203t, 204t, 205t, and 206t, and the time intervals 201i, 202i, 203i between two pulsation timings that are adjacent to each other in time series. , 204i, and 205i, respectively, are acquired as BBI. When the BBI data string acquired by the acquisition unit 11 is plotted with BBI on the vertical axis and time on the horizontal axis, a graph as shown in FIG. 4 is obtained. Such a BBI data string is acquired from each of the plurality of sensors included in the sensor unit 30. Therefore, the acquisition unit 11 acquires a BBI data string as shown in FIG. 4 for each sensor.

The calculation unit 12 calculates a BBI data string acquired by the acquisition unit 11 in the first period (acquired based on each of the plurality of detection values detected by the plurality of sensors included in the sensor unit 30 in the first period). In addition, for each BBI data string for each sensor, an outlier rate indicating the extent to which BBI outliers are included is calculated. The outlier rate is also called the outlier degree parameter. The calculation unit 12 functions as an outlier degree deriving means.

Note that an outlier value of BBI is a value that is impossible for a human heartbeat interval. For example, since a heartbeat interval of 2 seconds or more is impossible as a human heartbeat interval, among the data included in the BBI data string, data of 2 seconds or more is considered an outlier. In this embodiment, outliers of BBI are estimated by an outlier estimation process described later. For example, the BBI shown as the time interval 204i in FIG. 4 is estimated to be an outlier of the BBI by the outlier estimation process described below.

In the present embodiment, the calculation unit 12 calculates, for each sensor included in the sensor unit 30, the outlier rate attributable to each sensor at the timing of interest. When calculating the outlier rate caused by one of the sensors included in the sensor unit 30, the calculation unit 12 moves the timing of interest on the time axis and calculates the rate of outliers during the first period including the timing of interest (for example, the timing of interest). Percentage of BBI data estimated to be outliers among all BBI data included in the first period, acquired from the detection values detected by the sensor during one minute (centered on the timing) is calculated as the outlier rate (outlier degree parameter) caused by the sensor. That is, the outlier rate can be determined for each sensor using the following equation (1) based on the number of data of all BBIs existing in the first period and the number of outliers.
Outlier rate = number of BBI outliers that exist in the first period
÷ Number of all BBI data existing in the first period...(1)

For example, for a BBI data string acquired from one sensor, if the first period is one minute centered around the timing of interest, and there are no outliers in the BBI data for that one minute, then The outlier rate caused by the sensor at the timing of interest is zero. Furthermore, if half of the BBI data within that one minute is an outlier, the outlier rate attributable to the sensor at the timing of interest is 0.5. In addition, if all the values are outliers, the outlier frequency rate due to the sensor at the timing of interest is 1.

Since the BBI data string is acquired from each of the plurality of sensors included in the sensor section 30, and the outlier rate is calculated based on formula (1) from each data string for each sensor, the calculation section 12 calculates the outlier rate for each sensor. Calculate the outlier rate. Furthermore, the calculation unit 12 calculates one outlier rate for each timing of interest while shifting the timing of interest for each sensor. Therefore, if the timing of interest is shifted by one minute, the outlier rate caused by each sensor will be calculated every minute.

For example, the acquisition unit 11 acquires a BBI data string corresponding to each sensor from ballistocardial signals detected by three sensors 31s, 32s, and 33s as shown in FIG. When the outlier rate is calculated for the BBI data string corresponding to the sensor while shifting the timing of interest, a data string with a different outlier rate for each sensor is calculated, as shown in FIG. 5, for example. In FIG. 5, as an example, a curve 310 connects points representing a data string of outlier rate corresponding to sensor 31s with a line, and a curve 320 connects points representing a data string of outlier rate corresponding to sensor 32s with a line. , and a curve 330 connecting points representing the data string of the outlier rate corresponding to the sensor 33s with a line, respectively.

Note that if the outlier rate calculation cycle and the BBI acquisition cycle are matched, a corresponding outlier rate will be obtained for each BBI. However, for each BBI, it is possible to match the outlier rate when the timing closest to the timing of the BBI (pulsation timing) is taken as the timing of interest, so the calculation cycle of the outlier rate and the acquisition cycle of the BBI can be matched. There's no need to do it.

The selection unit 13 selects, from among the BBI data for each sensor acquired by the acquisition unit 11, BBI data with a lower degree of inclusion of outliers expressed by the outlier rate for each sensor calculated by the calculation unit 12. do. Through the biological information acquisition process described later, the BBI data selected by the selection unit 13 is estimated to correspond to a more accurate heartbeat interval, and is acquired as the final BBI data. The selection unit 13 functions as a selection means. For example, if the outlier rate calculated for each sensor is as shown in FIG. In the time period 302i, select the BBI data string obtained from the detected value of the sensor 31s, and in the time period 303i, select the BBI data string obtained from the detected value of the sensor 33s. Select data columns.

The functional configuration of the biological information acquisition device 100 has been described above. Next, biometric information acquisition processing by the biometric information acquisition device 100 will be described with reference to FIG. 6. When the biometric information acquisition device 100 receives an instruction to start the biometric information acquisition process from the user via the input unit 41, it starts the biometric information acquisition process. Note that the user of the biological information acquisition device 100 may or may not be the subject of the biological information acquisition process.

First, the acquisition unit 11 of the biological information acquisition device 100 acquires ballistocardial signals detected by each sensor of the sensor unit 30 (step S101). Step S101 is normally performed continuously during a predetermined biosignal acquisition period (for example, a period from when the subject 52 whose heart rate interval is to be acquired starts sleeping (when the subject 52 goes to bed) to when the subject 52 wakes up). During that time, the acquisition unit 11 stores the detection values (ballistocardial signals) detected by each sensor of the sensor unit 30 in chronological order for each sensor along with the detection time (so that it can be seen which sensor has detected the value). 20. In step S101, the acquisition unit 11 does not need to know the subject's bedtime or wake-up time accurately, and may set the biological signal acquisition period by simply setting a timer (for example, from 11:00 p.m. to 7:00 p.m.). Further, the biological signal acquisition period may be set by an instruction from the input unit 41 (instruction to start and end acquisition of ballistocardial signals).

Next, the acquisition unit 11 selects the first sensor (or the next sensor when step S102 is executed for the second time or later) among the detected values (ballistocardial signals) of each sensor stored in the storage unit 20. A detected value is selected (step S102). Then, the acquisition unit 11 acquires a BBI data string based on the detected value of the sensor selected in step S102 (step S103), and in chronological order for each sensor (so that it can be seen which sensor caused the BBI). The information is stored in the storage unit 20.

Next, the calculation unit 12 performs outlier estimation processing, which will be described later (step S104). Then, the calculation unit 12 moves the timing of interest on the time axis by a predetermined period of time (for example, 1 minute), and calculates a first period including the timing of interest (for example, from 30 seconds before to 30 seconds after the timing of interest). For the BBI data for 1 minute), an outlier rate is calculated based on the outlier information estimated in step S104 (step S105), and all the calculated outlier rates (outlier rate along the time series) are calculated (step S105). data string) is stored in the storage unit 20 for each sensor (so that it can be seen which sensor causes the outlier rate). Step S105 is also called an outlier level derivation step.

Next, the calculation unit 12 removes outliers from the chronological BBI data string stored in the storage unit 20 (step S106). For example, if the BBI acquired by the acquisition unit 11 in step S103 is a data string as shown in FIG. After the values are removed, the BBI data string becomes a data string as shown in FIG.

Next, the calculation unit 12 determines whether the outlier rate due to the sensor has been calculated for all the sensors (step S107). If there is a sensor whose outlier rate has not yet been calculated (step S107; No), the process returns to step S102, selects the next sensor, and calculates the outlier rate.

When the calculation of the outlier rate caused by the sensor is completed for all the sensors (step S107; Yes), the selection unit 13 selects the BBI data string corresponding to each sensor stored in the storage unit 20 in chronological order. From among these, BBI data corresponding to the sensor with the minimum outlier rate due to the sensor is selected in chronological order, and the data string consisting of the selected BBI is used as the final BBI (heartbeat interval). It is stored in the storage unit 20 as a data string (step S108), and the biometric information acquisition process is ended. Step S108 is also called a selection step. Note that after selecting the final BBI data string in step S108, the selection section 13 outputs the BBI data string to the output section 42 or transmits it to an external device via the communication section 43. It's okay.

Next, the outlier estimation process executed in step S104 of the biological information acquisition process will be described with reference to FIG. 8.

First, the calculation unit 12 reads out the BBI from a chronological BBI data string stored in the storage unit 20 in the order in which it was stored, with the BBI as the BBI of interest (step S201). Then, the calculation unit 12 determines whether or not the BBI of interest is smaller than the first threshold (TH1) (step S202). If the BBI of interest is equal to or greater than the first threshold (step S202; No), the process advances to step S205.

If the BBI of interest is less than the first threshold (Step S202; Yes), the calculation unit 12 determines whether the adjacent BBI difference is smaller than the second threshold (TH2) (Step S203). Here, the adjacent BBI difference is the absolute value of the difference between the BBI of interest and the BBI next to the BBI of interest (BBI adjacent to the BBI of interest), and is also referred to as an adjacent interval difference. If the adjacent BBI difference is equal to or greater than the second threshold (step S203; No), the process advances to step S205.

If the adjacent BBI difference is less than the second threshold (step S203; Yes), the calculation unit 12 determines whether the two adjacent BBI differences are smaller than the third threshold (TH3) (step S204). Here, the two adjacent BBI differences are the difference between the adjacent BBIs in step S203 (the absolute value of the difference between the BBI of interest and the BBI next to the BBI of interest) and the difference between the adjacent BBIs adjacent thereto (the difference between the BBI next to the BBI of interest and the BBI of interest). (the absolute value of the difference from the next BBI). If the two-adjacent BBI difference is greater than or equal to the third threshold (step S204; No), the process advances to step S205.

If the two-adjacent BBI difference is less than the third threshold (step S204; Yes), the process advances to step S206.

In step S205, the calculation unit 12 estimates the BBI of interest as an outlier, and proceeds to step S206. In step S205, flag information indicating that the BBI of interest is estimated to be an outlier is added to the data of the BBI of interest stored in the storage unit 20 so that it can be seen that the calculation unit 12 has estimated the BBI of interest to be an outlier. It's okay.

In step S206, it is determined whether or not there is a BBI next to the BBI of interest in the chronological BBI data string stored in the storage unit 20. If the next BBI exists (step S206; Yes), the process returns to step S201. If the next BBI does not exist (step S206; No), the outlier estimation process is ended and the process returns to the biometric information acquisition process from step S105.

By performing the above biological information acquisition process and outlier estimation process, the BBI acquired from the detected value by the sensor, which has a lower outlier rate due to the sensor, is acquired as the heartbeat interval. Therefore, the biological information acquisition device 100 can appropriately acquire biological information such as the heartbeat interval of the subject. In addition, the calculation unit 12 calculates the outlier rate caused by each sensor while moving the first period on the time axis, so when the outlier rate changes over time, it is possible to calculate the outlier rate in each time period. It becomes possible to acquire biological information with the lowest outlier rate. Moreover, since the calculation unit 12 estimates outliers based on the first threshold, the second threshold, and the third threshold, it is possible to estimate outliers with higher accuracy.

Note that the first, second, and third threshold values are set in advance through experiments, but may be changed depending on the subject. For example, if the subject's heart rate and the difference between adjacent BBIs are known, each threshold value may be set accordingly. Furthermore, as the subject gets older, the heart rate generally decreases and the difference between adjacent BBIs also decreases (BBI is the reciprocal of the heart rate), so each threshold value may be changed depending on the age of the subject.

For example, each threshold value is determined in advance through an experiment targeting all age groups (the threshold values determined through the experiment are respectively referred to as a first reference threshold value, a second reference threshold value, and a third reference threshold value). In particular, if the subject is a young person (an age group below the first standard age (for example, 20 years old)), the first threshold value should be made small (for example, the first standard threshold value is divided by the first coefficient for young people), The second and third thresholds are increased (for example, the second reference threshold is multiplied by the second coefficient for young people, and the third reference threshold is multiplied by the third coefficient for young people). However, it is assumed that all of these coefficients (generally referred to as age coefficients) are larger than 1. Further, only one or two of these three threshold values may be changed.

On the other hand, if the subject is an older age group (an age group over the second reference age (e.g. 60 years old)), the first threshold value should be increased (e.g., the first reference threshold value should be multiplied by the first coefficient for elderly people). ), the second and third thresholds are made smaller (for example, the second reference threshold is divided by the second coefficient for elderly people, and the third reference threshold is divided by the third coefficient for elderly people). It is assumed that all of these age coefficients are also larger than 1. Further, only one or two of these three threshold values may be changed.

Further, the first threshold value also changes depending on the exercise state of the subject (sleeping, sitting, exercising, etc.). Specifically, the higher the degree to which the subject is resting, the larger the first threshold value becomes, and the higher the degree to which the subject is exercising vigorously, the smaller the first threshold value becomes.

Therefore, for example, if the first threshold value obtained through an experiment for a sleeping subject is the first reference threshold value, then depending on the exercise state of the subject, the first threshold value while seated is The first threshold during exercise may be a value obtained by dividing the first reference threshold by the motion state coefficient during exercise (for example, 1.5). Furthermore, the threshold value may be set using both the above-mentioned age coefficient and the above-mentioned exercise state coefficient. By changing each threshold value according to the age and exercise state of the subject in this way, outliers can be estimated with higher accuracy. However, the age and exercise state of the subject are input from the input section 41, and the calculation section 12 sets each threshold based on the information input from the input section 41.

In addition, in the above-mentioned outlier estimation process, three condition judgments were made using all three threshold values, but if at least one condition judgment is made among these three condition judgments, the other condition judgments can be made. You don't have to do it.

(Second embodiment)
In the first embodiment, in step S105 of the biological information acquisition process (FIG. 6), the calculation unit 12 shifts the timing of interest and targets BBI data included in the first period near the timing of interest. The value rate was calculated. Then, if the calculated outlier rate changes over time as shown in FIG. , BBI data strings obtained from detection values of different sensors (sensors 31s, 32s, 33s) were selected.

In the first embodiment, in a situation where the outlier rate changes from moment to moment, accuracy can be improved by selecting a data string with a lower outlier rate from the BBI data string acquired for each sensor in a short cycle. Although it is possible to obtain a heartbeat interval that is considered to be high, it requires a large amount of processing. However, there may be cases where the amount of processing may be reduced, such as a situation where the outlier rate does not change much over time. A second embodiment in which the amount of processing is reduced for such a case will be described.

The functional configuration of the biological information acquisition device 101 according to the second embodiment is basically the same as the functional configuration of the biological information acquisition device 100 according to the first embodiment shown in FIG. The functionality is slightly different.

When calculating outliers, the calculation unit 12 according to the second embodiment targets all BBIs included in the BBI data string acquired from the detection values of each sensor for each sensor, and calculates all BBIs. The proportion of BBIs that are considered to be outliers is calculated as an outlier rate (outlier degree parameter). In the second embodiment, one outlier rate corresponding to the entire period of the above-mentioned biosignal acquisition period, that is, the entire period from when the subject starts sleeping to when the subject wakes up, is calculated, so the sensor One outlier rate is calculated for each time.

Further, the outlier estimation process according to the second embodiment is the same as the outlier estimation process according to the first embodiment, and is shown in FIG. 8. However, the biological information acquisition process of the biological information acquisition apparatus 101 according to the second embodiment is partially different from the biological information acquisition process of the biological information acquisition apparatus 100 according to the first embodiment. Specifically, as shown in FIG. 9, the biological information acquisition process of the biological information acquisition apparatus 101 according to the second embodiment is the same as the biological information acquisition process of the biological information acquisition apparatus 100 according to the first embodiment (see FIG. Step S105 and step S108 in 6) are replaced with step S111 and step S112, respectively. The biometric information acquisition process of the biometric information acquisition device 101 according to the second embodiment will be described with reference to FIG. 9.

The processing from step S101 to step S104 is similar to the biological information acquisition processing according to the first embodiment.

In addition, in step 111, the calculation unit 12 calculates the outlier rate caused by the sensor for each sensor with respect to the BBI data string in all the periods (biological signal acquisition period) in which ballistocardial signal data was acquired in step S101. is calculated, and the calculated outlier rate is stored in the storage unit 20 for each sensor (so that it can be seen which sensor the outlier rate is caused by). This outlier rate can be determined using the following equation (2).
Outlier rate = number of BBI outliers that exist during the biosignal acquisition period
÷The number of all BBI data existing during the biosignal acquisition period...(2)

In the first embodiment, the outlier rate is calculated for each timing of interest, but in the second embodiment, one outlier is calculated for all periods in which ballistocardial signal data was acquired in step S101. . Therefore, the amount of processing in step S111 is much smaller than the amount of processing in step S105.

The processing in step S106 and step S107 is the same as the biological information acquisition processing according to the first embodiment.

In addition, in step S112, the selection unit 13 selects a sensor corresponding to the sensor with the minimum outlier rate caused by the sensor from among the BBI data strings corresponding to each sensor stored in the storage unit 20 in chronological order. A BBI data string is selected, and the selected BBI data string is stored in the storage unit 20 as a final BBI (heartbeat interval) data string. In the second embodiment, only one value of the outlier rate is calculated for each sensor, so it is necessary to select the BBI corresponding to the sensor with the minimum outlier rate at each timing, as in the first embodiment. There is no. Therefore, the amount of processing in step S112 is much smaller than the amount of processing in step S108.

By performing the above biological information acquisition processing, the biological information acquisition device 101 can appropriately acquire biological information such as the heartbeat interval of the subject, similarly to the first embodiment. Furthermore, in a situation where the temporal change in the outlier rate is small, the biometric information acquisition device 101 can appropriately acquire biometric information with a smaller processing amount than in the first embodiment.

(Modified example)
In the above-described embodiment, the sensor is provided with a sensor that detects a detection value for acquiring the heartbeat interval as biological information, and the heartbeat interval is acquired, but the biological information to be acquired is not limited to the heartbeat interval. If the biological information acquisition devices 100 and 101 target biological information for which outliers can be estimated, the biological information acquisition devices 100 and 101 select values detected by the sensor with a lower outlier rate caused by the sensor from among the data string of the acquired biological information. By selecting the data string acquired from the selection unit 13, it is possible to more appropriately acquire not only the heartbeat interval but also any biological information.

Furthermore, in the above-described embodiment, in step S106 of the biological information acquisition process (FIGS. 6 and 9), a process is performed to remove outliers in the heartbeat interval, but this process is not essential.

Furthermore, in the above-described embodiment, in step S101 of the biological information acquisition process (FIGS. 6 and 9), one night's worth of data, that is, data of ballistocardial signals from the time the subject starts going to sleep until the time he wakes up is acquired. However, one night's worth of data is not required. Once data for a predetermined period of time (for example, 1 hour) is acquired, the process proceeds to step S102, where the above-described process is performed using the data obtained so far (for example, 1 hour of data), and step S108 (step S112) After that, the process may return to step S101 and the biometric information acquisition process may be repeated at predetermined time intervals.

Furthermore, in the embodiments described above, the biological information acquisition devices 100 and 101 were equipped with the input section 41, the output section 42, and the communication section 43, but these are not essential components, and the biological information acquisition devices 100 and 101 are , it is not necessary to have these.

Further, in the above embodiment, the plurality of sensors included in the sensor unit 30 detect the same type of biological signal (ballistocardial signal) by detecting the same type of detection value (air pressure), but these The detection values and biological signals of the plurality of sensors do not have to be of the same type. For example, some sensors detect air pressure as a detection value to detect ballistocardial signals or BBI as biological information, while other sensors detect light as a detection value to detect biological signals. It may also be one that detects volume pulse waves or BBI.

Further, in the above-described embodiment, the outlier rate indicating the proportion of outliers included is used as the outlier degree parameter, but the outlier degree parameter is not limited to the outlier rate. For example, it may be the reciprocal of the outlier rate, the number of times an outlier has occurred, or the like. Further, the outlier degree deriving means may derive the outlier degree parameter using a table or the like instead of calculating (deriving) the outlier degree parameter from a mathematical formula or the like.

Furthermore, in the above-described embodiments, the biological information acquisition devices 100 and 101 acquire heart rate intervals of human subjects, but they are not limited to humans, but can also be used for general animals such as dogs, cats, horses, cows, pigs, and chickens. It is possible to target Even when targeting these animals, the biological information acquisition devices 100 and 101 select biological information based on the detected value of the sensor with a lower outlier rate in the selection unit 13, so that the biological information of the animal is more appropriate. This is because it is possible to obtain

Furthermore, each function of the biological information acquisition apparatuses 100 and 101 can be performed by a computer such as a normal PC (Personal Computer). Specifically, in the embodiment described above, it is assumed that programs such as biological information acquisition processing performed by the biological information acquisition apparatuses 100 and 101 are stored in advance in the ROM of the storage unit 20. However, programs can be stored on flexible disks, CD-ROMs (Compact Disc Read Only Memory), DVDs (Digital Versatile Discs), MOs (Magneto-Optical Discs), memory cards, and USBs (Universal Serial Discs). al Bus) computer-readable data such as memory A computer that can realize each of the above-mentioned functions may be configured by storing and distributing the program on a recording medium, reading the program into the computer, and installing the program.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to such specific embodiments, and the present invention includes the inventions described in the claims and their equivalents. It will be done. Below, the invention described in the original claims of the present application will be added.

(Additional note 1)
An outlier degree parameter representing the extent to which outliers of the biological information are included in multiple sets of biological information of the same type of the target, acquired from each of a plurality of mutually different parts of the target in the first period. Outlier degree derivation means for deriving each,
Selection means for selecting the biological information that contains a smaller outlier of the biological information from among the biological information of the same type acquired at each of the plurality of different parts;
A biological information acquisition device comprising:

(Additional note 2)
The outlier degree deriving means determines, as the outlier degree parameter, an outlier rate representing a proportion of outliers included in the biological information for each of the plurality of sets of biological information acquired in the first period. calculate,
The biological information acquisition device according to Supplementary Note 1.

(Additional note 3)
The outlier degree deriving means calculates the outlier degree parameter based on each of the plurality of sets of biological information while moving the first period on a time axis.
The biological information acquisition device according to supplementary note 1 or 2.

(Additional note 4)
the subject is a human test subject;
a plurality of sensors that detect detection values for obtaining heartbeat intervals from a plurality of different parts of the subject;
Acquisition means for acquiring heartbeat intervals based on detection values detected by each of the plurality of sensors;
Furthermore,
The outlier degree deriving means determines that the heartbeat interval acquired by the acquiring means is equal to or greater than a first threshold, or that the adjacent heartbeat interval difference, which is the absolute value of the difference between the adjacent heartbeat intervals calculated from the heartbeat interval, is the first. The heartbeat interval is an outlier when the heartbeat interval is greater than or equal to a third threshold, or when the two-adjacent interval difference, which is the sum of the adjacent interval difference calculated from the heartbeat interval and the adjacent interval difference adjacent thereto, is greater than or equal to a third threshold. It is determined that
The biological information acquisition device according to any one of Supplementary Notes 1 to 3.

(Appendix 5)
The outlier degree deriving means includes:
changing at least one of the first threshold, the second threshold, or the third threshold based on the age of the subject;
The biological information acquisition device according to appendix 4.

(Appendix 6)
The outlier degree deriving means includes:
changing the first threshold based on the exercise state of the subject;
The biological information acquisition device according to appendix 4 or 5.

(Appendix 7)
An outlier degree parameter representing the extent to which outliers of the biological information are included in multiple sets of biological information of the same type of the target, acquired from each of a plurality of mutually different parts of the target in the first period. a step of deriving outlier degrees, respectively;
a selection step of selecting the biometric information that contains a smaller outlier of the biometric information from among the biometric information of the same type acquired at each of the plurality of different parts;
A biological information acquisition method comprising:

(Appendix 8)
to the computer,
An outlier degree parameter representing the extent to which outliers of the biological information are included in multiple sets of biological information of the same type of the target, acquired from each of a plurality of mutually different parts of the target in the first period. a step of deriving outlier degrees, and
a selection step of selecting the biological information in which the degree of inclusion of an outlier of the biological information is smaller among the biological information of the same type acquired at the plurality of different parts;
A program to run.

DESCRIPTION OF SYMBOLS 10... Control part, 11... Acquisition part, 12... Calculation part, 13... Selection part, 20... Storage part, 30... Sensor part, 31s, 32s, 33s... Sensor, 31t, 32t, 33t... Tube, 41... Input part , 42... Output section, 43... Communication section, 51... Mattress, 52... Subject, 100, 101... Biological information acquisition device, 200... Data string of ballistocardial signal, 200w, 300w... Time window, 201, 202, 203 , 204, 205, 206, 312... points, 201i, 202i, 203i, 204i, 205i... time interval, 201t, 202t, 203t, 204t, 205t, 206t... pulsation timing, 301i, 302i, 303i... time period, 310 , 320, 330...Curve, 312t...Timing

Claims (8)

Acquisition means for acquiring a plurality of sets of biological information of the same type of the target from each of a plurality of mutually different parts of the target in a first period;
Detection means for detecting a heartbeat interval in the biological information by detecting one peak at each predetermined detection time interval shorter than the first period;
An outlier level parameter is derived from each of the plurality of sets of biological information , using the heartbeat interval and a predetermined threshold, to derive an outlier degree parameter representing the extent to which the outlier is included in the first period in the biological information. a degree deriving means;
Selection means for selecting the biological information having the smaller outlier degree parameter from among the biological information of the same type acquired from each of the plurality of different parts;
A biological information acquisition device comprising: The outlier degree deriving means determines, as the outlier degree parameter, an outlier rate representing a proportion of outliers included in the biological information for each of the plurality of sets of biological information acquired in the first period. calculate,
The biological information acquisition device according to claim 1. The outlier degree deriving means calculates the outlier degree parameter based on each of the plurality of sets of biological information while moving the first period on a time axis.
The biological information acquisition device according to claim 1 or 2. a plurality of sensors that detect detection values for obtaining heartbeat intervals from a plurality of different parts of the target ;
Furthermore ,
The outlier degree deriving means is configured to determine whether an adjacent interval difference, which is an absolute value of the difference between the adjacent heartbeat intervals calculated from the heartbeat interval, is equal to or greater than a second threshold, or the adjacent interval calculated from the heartbeat interval. determining that the heartbeat interval is an outlier when a two-adjacent interval difference, which is the sum of the difference and the adjacent interval difference adjacent thereto, is greater than or equal to a third threshold;
The biological information acquisition device according to any one of claims 1 to 3. The outlier degree deriving means includes:
changing at least one of the second threshold or the third threshold based on the age of the subject ;
The biological information acquisition device according to claim 4. The outlier degree deriving means includes:
changing the predetermined threshold based on the movement state of the object ;
The biological information acquisition device according to any one of claims 1 to 5 . an acquisition step of acquiring a plurality of sets of the same type of biological information of the target from each of a plurality of mutually different parts of the target in a first period, which is executed by a computer;
a detection step of detecting a heartbeat interval by detecting one peak in the biological information at each predetermined detection time interval shorter than the first period, the detection step being executed by the computer;
The outlier degree parameter representing the extent to which an outlier is included in the first period in the biological information is calculated by the computer using the heartbeat interval and a predetermined threshold value for the plurality of sets of biological information . a step of deriving an outlier degree from each of the
a selection step of selecting the biological information having the smaller outlier degree parameter from among the biological information of the same type acquired from each of the plurality of different body parts , which is executed by the computer ;
A biological information acquisition method comprising: to the computer,
an acquisition step of acquiring a plurality of sets of biological information of the same type of the target from each of a plurality of mutually different parts of the target in a first period;
a detection step of detecting one peak in the biological information at each predetermined detection time interval shorter than the first period to detect a heartbeat interval;
An outlier level parameter is derived from each of the plurality of sets of biological information , using the heartbeat interval and a predetermined threshold, to derive an outlier degree parameter representing the extent to which the outlier is included in the first period in the biological information. a degree derivation step ;
a selection step of selecting the biological information having the smaller outlier degree parameter from among the biological information of the same type acquired from each of the plurality of different parts;
A program to run.

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