JP2008113797A - Biological signal detection device - Google Patents

Abstract

A biological signal detection apparatus capable of accurately extracting a biological signal in a posture-changing bedding.
The bedding is a posture change type that can freely change the posture of supporting the human body to be detected, and is installed in each of a plurality of detection target portions K in the bedding to detect a change in pressure applied to the detection target portion K. And a biological signal extraction unit 4 that extracts a biological signal from the detection signal of the pressure fluctuation detection sensor 2 weighted in units of detection target parts K according to the posture state of the bedding.
[Selection] Figure 2

Description

  The present invention relates to a biological signal detection apparatus that detects a biological signal corresponding to a biological state of a human body to be detected by bedding.

The biological signal detection apparatus as described above detects a biological signal such as a respiratory signal or a pulse signal of a human body to be detected in a bedding such as a futon or a bed. The biological signal detection device includes a pressure fluctuation detection sensor that is installed in the bedding and detects pressure fluctuation applied to the bedding, and a biological signal extraction unit that extracts a biological signal from the detection signal of the pressure fluctuation detection sensor. Yes.
Depending on the physique and body shape of the detection target human body and the position where the detection target human body is sleeping, the area where pressure is applied in the bedding changes, so in order to accurately detect pressure fluctuation with the pressure fluctuation detection sensor, It is required to arrange a pressure fluctuation detection sensor at a site where pressure is applied to the sensor.

  Therefore, in the conventional biological signal detection device, in a bed as a bedding, a portion that supports a portion from the chest to the abdomen of a human body to be detected is set as a detection target portion, and the width direction and the vertical direction of the bed are set in the detection target portion. A plurality of pressure fluctuation detection sensors are arranged at intervals in the width direction (see, for example, Patent Document 1).

JP 2004-113340 A

  In the conventional biological signal detection device, when the detection target human body is sleeping, the pressure fluctuation can be accurately detected by the pressure fluctuation detection sensor, and the biological signal is extracted from the detection signal of the pressure fluctuation detection sensor. Can do. However, as the bedding, not only a posture for supporting the detection target human body that is sleeping, but also a posture change type that can freely change the posture for supporting the detection target human body, such as a posture for supporting the detection target human body that has raised its upper body. is there. In such a posture change type bedding, the portion to which pressure is applied changes when the posture supporting the detection target human body is changed. Therefore, in the conventional biological signal detection device, in the posture change type bedding, the pressure fluctuation cannot be accurately detected by the pressure fluctuation detection sensor, and the biological signal may not be accurately extracted.

  This invention is made paying attention to this point, and the objective is to provide the biological signal detection apparatus which can extract a biological signal accurately in the posture change type bedding.

  In order to achieve this object, the characteristic configuration of the biological signal detection device according to the present invention is a biological signal detection device that detects a biological signal corresponding to a biological state of a human body to be detected by the bedding. A pressure change detection sensor for changing a posture for supporting a human body, wherein the pressure change detection sensor is installed in each of a plurality of detection target parts in the bedding and detects a change in pressure applied to the detection target part; and And a biological signal extraction unit that extracts the biological signal from the detection signal of the pressure fluctuation detection sensor weighted in units of the detection target part according to the posture state.

That is, since a pressure fluctuation detection sensor is installed in each of a plurality of detection target parts in the bedding, a part where pressure is surely applied in each of the posture states of the bedding is set as the detection target part, and pressure fluctuation detection is performed in the detection target part. Sensors can be installed. And since the biological signal extraction part extracts from the detection signal of the pressure fluctuation detection sensor weighted for each detection target part according to the posture state of the bedding, the detection target to which the pressure is surely applied according to the posture state of the bedding By increasing the weight of the detection signal of the pressure fluctuation detection sensor installed at the site, the biological signal can be extracted while accurately detecting the pressure fluctuation in each posture state of the bedding.
Therefore, it has become possible to provide a biological signal detection device that can accurately extract a biological signal in a posture-changing bedding.

  In the biological signal detection apparatus according to the present invention, the biological signal extraction unit uses, as the weighting, the detection signal of the pressure fluctuation detection sensor as the extraction target of the biological signal according to the posture state of the bedding. It is preferable that the switching is performed in units.

  In other words, the biological signal extraction unit simply switches the detection signal of the pressure fluctuation detection sensor, which is the extraction target of the biological signal, in units of detection target parts according to the posture state of the bedding, and the bedding with respect to the detection signal of the pressure fluctuation detection sensor. It is possible to perform weighting in units of detection target parts according to the posture state. Then, the biological signal extraction unit can extract the biological signal only from the detection signal of the pressure fluctuation detection sensor installed in the detection target portion to which pressure is applied according to the posture state of the bedding. Therefore, the biological signal can be extracted with higher accuracy while simplifying the configuration.

  In the biological signal detection apparatus according to the present invention, the biological signal extraction unit is configured to detect the detection target part unit according to the posture state of the bedding with respect to a detection state value obtained by quantifying the magnitude of the detection signal from each pressure fluctuation detection sensor. It is preferable that the system is configured to determine whether or not to extract the biological signal based on the weighted detection state value.

That is, as the detection state value becomes larger, it can be determined that the pressure fluctuation can be accurately detected by the pressure fluctuation detection sensor, so that the detection signal of the pressure fluctuation detection sensor can be determined depending on the magnitude of the detection state value. Whether or not an effective biological signal can be extracted can be determined. The biological signal extraction unit weights the detection state value in each pressure fluctuation detection sensor in units of detection target parts according to the posture state of the bedding, thereby obtaining the detection state value according to the posture state of the bedding. Obtainable. Therefore, the biological signal extraction unit determines whether or not to extract a biological signal based on the detection state value weighted in units of detection target parts according to the posture state of the bedding, thereby obtaining an effective biological signal. Whether or not extraction can be performed can be determined according to the posture state of the bedding.
The biological signal extraction unit can extract an effective biological signal with high accuracy by extracting the biological signal when it is determined that the biological signal is extracted.

  In the biological signal detection apparatus according to the present invention, the bedding includes a seating site that supports a portion corresponding to the buttocks of the human body to be detected and a backrest site that supports a portion corresponding to the back of the human body to be detected, The detection target part is preferably set so as to include at least the seating part and the backrest part.

That is, when the posture state of the bedding is a posture state supporting the human body to be detected, the pressure is surely applied to the backrest portion. By setting this backrest part as the detection target part, the detection target part in the posture state that supports the sleeping detection target human body can be accurately set. In addition, when the posture state of the bedding is a posture state supporting the detection target human body that has caused the upper body, pressure is surely applied to the sitting portion. By setting this seating part as the detection target part, the detection target part in the posture state that supports the detection target human body that has caused the upper body can be accurately set.
In this way, pressure fluctuations can be accurately detected even in the posture state of a bedding that supports the detection target human body sleeping or in the posture state of the bedding that supports the detection target human body that has caused the upper body. And a biological signal can be extracted with high accuracy.

An embodiment of a biological signal detection device according to the present invention will be described with reference to the drawings.
[First Embodiment]
As shown in FIGS. 1 and 2, the biological signal detection device includes a pressure fluctuation detection sensor 2 that detects a pressure fluctuation applied to the bed 1 as a bedding, and a detection signal from the pressure fluctuation detection sensor 2 in the bed 1. And a biological signal extraction unit 4 that detects a biological signal corresponding to the biological state of the human body 3 to be detected.

The bed 1 includes a mat 5 on which a human body 3 to be detected is placed, a panel 6 that supports the mat 5, and a frame 7 that supports the panel 6. The panel 6 is divided into a first panel 6a, a second panel 6b, a third panel 6c, and a fourth panel 6d from the head side toward the leg side. The second panel 6b is fixed to the frame 7, and the adjacent panels 6a to 6d are rotatably connected to each other.
In the bed 1, a part corresponding to the back 3a corresponding to the back of the human body 3 to be detected is supported by the first panel 6a and a part of the mat 5 located on the first panel 6a, and the second panel 6b and the second panel 6b A part of the mat 5 located on the two panel 6b supports a buttock-corresponding portion 3b corresponding to the buttock of the human body 3 to be detected. Thus, a part of the mat 5 located on the first panel 6a and the first panel 6a becomes the backrest portion K1, and a part of the mat 5 located on the second panel 6b and the second panel 6b is seated. It becomes the site | part K2.

The bed 1 swings the first panel 6a with respect to the second panel 6b to support the human body 3 to be detected as shown in FIG. As shown in (2), it is configured to be changeable to an inclined posture that supports the detection target human body 3 that has raised its upper body. Further, by swinging the third panel 6c upward with respect to the second panel 6b, the posture can be changed to support the detection target human body 3 with the knee bent as shown in FIG. 1 (c). It is.
Thus, the bed 1 supports the detection target human body 3 by swinging the first panel 6a with respect to the second panel 6b and swinging the third panel 6c with respect to the second panel 6b. Is configured to change the posture.

  Various configurations can be applied to the configuration for swinging the first panel 6a and the third panel 6c. For example, although not illustrated, the first panel 6a and the third panel 6c are swung by moving the member supporting the first panel 6a and the member supporting the third panel 6c by driving the electric motor. Can do. Then, the posture of the bed 1 is commanded by human operation of the operation unit, and the drive device that controls the drive of the electric motor controls the drive of the electric motor based on the command, thereby commanding by the human operation of the operation unit. The posture state of the bed 1 can be changed to the posture state.

The pressure fluctuation detection sensor 2 is constituted by a piezoelectric film using a polymer piezoelectric material such as polyvinylidene fluoride (PVDF), for example. The pressure fluctuation detection sensor 2 is configured to be installed in each of the plurality of detection target parts K in the bed 1 and detect a pressure fluctuation applied to the detection target part K.
And as shown to Fig.1 (a), the backrest site | part K1 and the seating site | part K2 are set to the detection target site | part K. FIG.

The backrest portion K1 is a portion to which pressure is reliably applied when the detection target human body 3 is sleeping. By setting the pressure fluctuation detection sensor 2 at the backrest portion K1, when the posture state of the bed 1 is the posture state supporting the detection target human body 3, the pressure fluctuation due to the detection target human body 3 is accurately detected. It can be detected.
The seating portion K2 is a portion to which pressure is surely applied when the upper body of the detection target human body 3 is raised. By setting the pressure fluctuation detection sensor 2 in the seating region K2, when the posture state of the bed 1 is a posture state that supports the human body 3 to be detected, the pressure variation due to the human body 3 to be detected is accurately detected. Can be detected.

A posture state detection unit 11 is provided that detects the posture state of the bed 1 and outputs posture state information corresponding to the detected posture state to the biological signal extraction unit 4. This posture state detection unit 11 detects whether the posture state of the bed 1 is a flat posture (FIG. 1B) or a tilted posture (FIG. 1C), and if it is a tilted posture, it is horizontal. It is configured to detect how much the vehicle is inclined with respect to the direction and output posture state information corresponding to the detected posture state of the bed 1.
Incidentally, the posture state detection unit 11 is based on, for example, the operation state of the electric motor for swinging the first panel 6a and the command information from the operation unit that commands the posture state of the bed 1. Is detected.

  The signal processing unit 8 including the biological signal extraction unit 4 includes a voltage conversion unit 9 that converts an output from the pressure fluctuation detection sensor 2 into a voltage, and an analog signal output from the voltage conversion unit 9 as a digital signal. And a digital conversion unit 10 for conversion. The detection signal from the pressure fluctuation sensor 2 converted by the digital conversion unit 10 is input to the biological signal extraction unit 4.

  Based on the posture state information input from the posture state detection unit 11, the biological signal extraction unit 4 is based on the detection signal of the pressure fluctuation detection sensor 2 that is weighted in units of detection target parts K according to the posture state of the bed 1. A biological signal is extracted. Then, the biological signal extraction unit 4 is configured to switch the detection signal of the pressure fluctuation detection sensor 2 as the extraction target of the biological signal for each detection target portion K according to the posture state of the bed 1 as the weighting. .

To explain, the biological signal extraction unit 4 determines whether the posture state of the bed 1 is the first posture state or the second posture state based on the posture state information input from the posture state detection unit 11. The detection signal of the pressure fluctuation detection sensor 2 to be extracted from the biological signal is switched between the backrest part K1 and the seating part K2.
The first posture state is a flat posture (FIG. 1B), or even if the bed 1 is in a tilted posture, the tilt angle is less than a set angle (for example, about 60 degrees) with respect to the horizontal direction. At the time. The second posture state is a tilted posture and the tilt angle is equal to or larger than a set angle (for example, about 60 degrees) with respect to the horizontal direction.

When the biological signal extraction unit 4 determines that the posture state of the bed 1 is the first posture state based on the posture state information input from the posture state detection unit 11, the pressure variation detection sensor that is a target for extraction of the biological signal. 2 is switched to the backrest K1.
Then, the biological signal extraction unit 4 selects one pressure fluctuation detection sensor 2 having the largest detection signal from the detection signals of the three pressure fluctuation detection sensors 2 installed in the backrest part K1, and selects the selected one pressure A biological signal is extracted from the detection signal of the fluctuation detection sensor 2. Incidentally, the biological signal extraction unit 4 is not limited to the detection signal of one selected pressure fluctuation detection sensor 2 for the extraction of the biological signal, but the detection signals of the three pressure fluctuation detection sensors 2 installed in the backrest part K1. It is also possible to extract a biological signal from the sum of.

FIG. 3 shows a detection signal of the pressure fluctuation detection sensor 2 when the posture state of the bed 1 is the first posture state (flat posture). In the figure, (a) is a detection signal of the pressure fluctuation detection sensor 2 installed in the backrest part K1, and (b) in the figure is a detection signal of the pressure fluctuation detection sensor 2 installed in the seating part K2. is there.
In this first posture state, the detection signal (a) of the pressure fluctuation detection sensor 2 installed in the backrest part K1 is more than the detection signal (b) of the pressure fluctuation detection sensor 2 installed in the seating part K2. Since the amplitude is large, the pressure fluctuation due to the detection target human body 3 can be accurately detected by the pressure fluctuation detection sensor 2 installed at the backrest K1. Therefore, as described above, when the biological signal extraction unit 4 determines that the state is the first posture state, the biological signal is extracted from the detection signal (a) of the pressure fluctuation detection sensor 2 installed in the backrest portion K1. Thus, the biological signal can be extracted with high accuracy.

When the biological signal extraction unit 4 determines that the posture state of the bed 1 is the second posture state based on the posture state information input from the posture state detection unit 11, the pressure variation detection sensor that is a target for extraction of the biological signal. 2 detection signal is switched to the seating site K2.
Then, the biological signal extraction unit 4 selects one pressure fluctuation detection sensor 2 having the largest output from the detection signals of the three pressure fluctuation detection sensors 2 installed at the seating site K2, and the selected one pressure fluctuation. A biological signal is extracted from the detection signal of the detection sensor 2. Incidentally, the biological signal extraction unit 4 is not limited to the detection signal of the selected one pressure fluctuation detection sensor 2 for the extraction of the biological signal, but the detection signals of the three pressure fluctuation detection sensors 2 installed in the seating site K2. It is also possible to extract a biological signal from the sum of.

FIG. 4 shows the pressure fluctuation detection sensor 2 when the posture state of the bed 1 is the second posture state (when it is a tilted posture and the tilt angle is a set angle (for example, 60 degrees) with respect to the horizontal direction). The detection signal is shown. In the figure, (a) is a detection signal of the pressure fluctuation detection sensor 2 installed in the backrest part K1, and (b) in the figure is a detection signal of the pressure fluctuation detection sensor 2 installed in the seating part K2. is there.
In this second posture state, the detection signal (b) of the pressure fluctuation detection sensor 2 installed at the seating part K2 is more than the detection signal (a) of the pressure fluctuation detection sensor 2 installed at the backrest part K1. Since the amplitude is large, the pressure fluctuation due to the detection target human body 3 can be accurately detected by the pressure fluctuation detection sensor 2 installed in the seating region K2. Therefore, as described above, when the biological signal extraction unit 4 determines that the state is the second posture state, the biological signal is extracted from the detection signal (b) of the pressure fluctuation detection sensor 2 installed in the seating region K2. Thus, the biological signal can be extracted with high accuracy.

The extraction of the biological signal will be described. The biological signal extraction unit 4 is configured to extract a pulse signal or a respiratory signal as a biological signal from the detection signal of the pressure fluctuation detection sensor 2. For the extraction of the pulse signal, the biological signal extraction unit 4 uses a band pass filter (BPF) or a low pass filter (LPF: Low Pass Filter) that allows a signal in a specific frequency band to pass. A pulse signal is extracted by passing a signal in a frequency band (for example, 4 to 7 Hz) peculiar to the pulse signal among the detection signals of the fluctuation detection sensor 2. Regarding the extraction of the respiration signal, the biological signal extraction unit 4 uses a band-pass filter to extract a respiration signal by passing a signal in the frequency band specific to the respiration signal among the detection signals of the pressure fluctuation detection sensor 2.
Incidentally, the biological signal is not limited to the pulse signal and the respiratory signal, and may be any signal relating to the biological state of the human body 3 to be detected. For example, various other signals such as a body motion signal can be extracted.

[Second Embodiment]
This second embodiment is another embodiment of the weighting in the first embodiment, and the biological signal extraction unit 4 detects the detection target part according to the posture state of the bed 1 with respect to the detection signal of the pressure fluctuation detection sensor 2. Weighting is performed in K units, and a biological signal is extracted from the detection signal of the pressure fluctuation detection sensor 2 that has been weighted.

  The biological signal extraction unit 4 determines whether the posture state of the bed 1 is the first posture state or the second posture state based on the posture state information input from the posture state detection unit 11, and the determination. According to the result, the first weighting value N1 and the second weighting value N2 (= 10−N1, N2 <N1) are assigned to the backrest part K1 and the seating part K2. Then, the biological signal extraction unit 4 uses the detection signal of the pressure fluctuation detection sensor 2 installed in the backrest part K1 and the detection signal of the pressure fluctuation detection sensor 2 installed in the seating part K2 as the first weighting value N1. Addition is performed according to the ratio with the second weighting value N2, and a biological signal is extracted from the added detection signal of the pressure fluctuation detection sensor 2.

If it demonstrates, if the biological signal extraction part 4 discriminate | determines that the attitude | position state of the bed 1 is a 1st attitude | position state, the 1st weighting value N1 (for example, 7) will be assigned with respect to the backrest part K1, and the seating part K2 Is assigned a second weighting value N2 (for example, 3). As described above, when the posture state of the bed 1 is the first posture state, the weight of the backrest portion K1 to which pressure is reliably applied in the first posture state is increased. Then, the biological signal extraction unit 4 uses the detection signal of the pressure fluctuation detection sensor 2 installed in the backrest part K1 and the detection signal of the pressure fluctuation detection sensor 2 installed in the seating part K2 as the first weighting value N1. Addition is performed according to the ratio (7: 3) with the second weighting value N2. For example, the detection signal of the pressure fluctuation detection sensor 2 installed at the backrest part K1 is multiplied by N1 in the detection signal and the detection signal of the pressure fluctuation detection sensor 2 installed at the seating part K2 is multiplied by N2 Is added. The biological signal extraction unit 4 extracts a biological signal from the added detection signal of the pressure fluctuation detection sensor 2.
In addition, when the biological signal extraction unit 4 determines that the posture state of the bed 1 is the second posture state, the biological signal extraction unit 4 assigns a first weighting value N1 (for example, 7) to the seating region K2, and assigns the backrest region K1 to the backrest region K1. A second weighting value N2 (for example, 3) is assigned to it. As described above, when the posture state of the bed 1 is the second posture state, the weight of the seating portion K2 to which the pressure is surely applied in the second posture state is increased.

[Third Embodiment]
In the third embodiment, the biological signal extraction unit 4 has a detection target value in units of detection target K in accordance with the posture state of the bed 1 with respect to the detection state value obtained by quantifying the magnitude of the detection signal from each pressure fluctuation detection sensor 2. Weighting is performed, and it is configured to determine whether or not to extract a biological signal based on the weighted detection state value.

For example, the biological signal extraction unit 4 sets the maximum value to 10 and sets any numerical value of 1 to 10 as the detection state value according to the magnitude of the detection signal of the pressure fluctuation detection sensor 2.
The larger the detection state value is, the more it can be determined that the pressure fluctuation detection sensor 2 can accurately detect the pressure fluctuation. Therefore, the detection signal of the pressure fluctuation detection sensor 2 can be detected based on the magnitude of the detection state value. Whether or not an effective biological signal can be extracted can be determined. Accordingly, the biological signal extraction unit 4 extracts the effective biological signal from the detection signal of the pressure fluctuation detection sensor 2 by summing the detection state values in the respective pressure fluctuation detection sensors 2 and comparing the total value with a threshold value. Whether or not it can be determined. Therefore, the biological signal extraction unit 4 extracts the biological signal as being able to extract an effective biological signal from the detection signal of the pressure fluctuation detection sensor 2 when the total value of the detection state values in each pressure fluctuation detection sensor 2 is equal to or greater than the threshold value. I do. Further, if the total value of the detection state values in each pressure fluctuation detection sensor 2 is less than the threshold value, the biological signal extraction unit 4 determines that a valid biological signal cannot be extracted from the detection signal of the pressure fluctuation detection sensor 2, and Do not extract.

  The biological signal extraction unit 4 does not simply use the detection state value in each pressure fluctuation detection sensor 2 but detects the detection state value according to the posture state of the bed 1 with respect to the detection state value by each pressure fluctuation detection sensor 2. It is determined whether or not the biological signal is to be extracted based on the total value obtained from the weighted detection state value by weighting the region K. Therefore, it is possible to determine whether or not an effective biological signal can be extracted according to the posture state of the bed 1.

  To explain, the biological signal extraction unit 4 determines whether the posture state of the bed 1 is the first posture state or the second posture state based on the posture state information input from the posture state detection unit 11, A first weighting value N1 and a second weighting value N2 (= 10−N1, N2 <N1) are assigned to the backrest part K1 and the seating part K2 according to the determination result. And the biosignal extraction part 4 is totaled according to the ratio of the 1st weighting value N1 and the 2nd weighting value N2 which allocated the detection state value in each pressure fluctuation detection sensor 2, and the total value is more than a threshold value. It is determined that the biological signal is to be extracted. If the total value is less than the threshold value, it is determined that the biological signal is not extracted.

For example, if the biological signal extraction unit 4 determines that the posture state of the bed 1 is the first posture state, the biological signal extraction unit 4 assigns a first weight value N1 (for example, 7) to the backrest portion K1, and assigns the seating portion K2 to the seating portion K2. A second weighting value N2 (for example, 3) is assigned to it. As described above, when the posture state of the bed 1 is the first posture state, the weight of the backrest portion K1 to which pressure is reliably applied in the first posture state is increased. Then, the biological signal extraction unit 4 uses the detection state value in the pressure fluctuation detection sensor 2 installed in the backrest part K1 and the detection state value in the pressure fluctuation detection sensor 2 installed in the seating part K2 as a first weighting value. Summing is performed according to the ratio (7: 3) between N1 and the second weighting value N2. For example, the detection state value in each pressure fluctuation detection sensor 2 installed in the backrest part K1 is multiplied by N1, and the detection state value in each pressure fluctuation detection sensor 2 installed in the seating part K2 is multiplied by N2. To sum. The biological signal extraction unit 4 determines that the biological signal is extracted when the total value is equal to or greater than the threshold value, and determines that the biological signal is not extracted when the total value is less than the threshold value.
In addition, when the biological signal extraction unit 4 determines that the posture state of the bed 1 is the second posture state, the biological signal extraction unit 4 assigns a first weighting value N1 (for example, 7) to the seating region K2, and assigns the backrest region K1 to the backrest region K1. A second weighting value N2 (for example, 3) is assigned to it. As described above, when the posture state of the bed 1 is the second posture state, the weight of the seating portion K1 to which the pressure is reliably applied in the second posture state is increased.

  Incidentally, in this third embodiment, in order to determine whether or not to extract a biological signal, a total value of weighted detection state values is obtained and compared with the threshold value. Whether to compare the value obtained by such calculation with the threshold value can be changed as appropriate.

[Another embodiment]
(1) In the first to third embodiments, the backrest part K1 and the seating part K2 are set as the detection target part K. What kind of part of the bed 1 the detection target part K is set as is Changes can be made as appropriate. For example, a portion that supports a portion corresponding to the waist of the detection target human body 3 can be set as the detection target portion K.

(2) In the first to third embodiments, the two parts, the backrest part K1 and the seating part K2, are the detection target parts K, but the number of detection target parts K set in the bed 1 can be changed as appropriate. is there. For example, in addition to the backrest part K1 and the seating part K2, three parts that support a part corresponding to the waist of the detection target human body 3 can be set as the detection target part K.

(3) In the second embodiment, the first weighting value N1 and the second weighting value N1 may be changed. In this case, for example, the biological signal extraction unit 4 changes and sets the first weighting value N1 and the second weighting value N1 based on the amplitude relationship in the detection signal of the pressure fluctuation detection sensor 2 in the detection target region K unit. can do.

(4) In the said 1st-3rd embodiment, although the bed 1 was illustrated as bedding, not only a bed but other various bedding can be adapted.

Top and side view of bed Block diagram of biological signal detection device The graph which shows the detection signal of the pressure fluctuation detection sensor in a 1st attitude | position state The graph which shows the detection signal of the pressure fluctuation detection sensor in a 2nd attitude | position state

Explanation of symbols

1 Bedding (bed)
2 Pressure Fluctuation Detection Sensor 3 Detection Target Human Body 4 Biological Signal Extraction Unit K Detection Target Part K1 Backrest Part K2 Seating Part

Claims (4)

A biological signal detection device that detects a biological signal corresponding to a biological state of a human body to be detected in bedding,
The bedding is a posture change type that can freely change the posture of supporting the detection target human body,
A pressure fluctuation detection sensor that is installed in each of a plurality of detection target parts in the bedding and detects a pressure fluctuation applied to the detection target part;
A biological signal detection apparatus comprising: a biological signal extraction unit that extracts the biological signal from a detection signal of the pressure fluctuation detection sensor weighted in units of the detection target part according to the posture state of the bedding.   The biological signal extraction unit is configured to switch, as the weighting, a detection signal of the pressure fluctuation detection sensor as an extraction target of the biological signal in units of the detection target portion according to the posture state of the bedding. Item 2. The biological signal detection device according to Item 1.   The biological signal extraction unit weights the detection state value obtained by quantifying the magnitude of the detection signal from each pressure fluctuation detection sensor in units of the detection target part according to the posture state of the bedding, and weights the detection state value. The biological signal detection device according to claim 1, wherein the biological signal detection device is configured to determine whether or not to extract the biological signal based on the detection state value. The bedding comprises a seating part that supports a part corresponding to the buttocks of the detection target human body and a backrest part that supports a part corresponding to the back of the detection target human body,
The biological signal detection device according to claim 1, wherein the detection target part is set so as to include at least the seating part and a backrest part.

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