JP2011120667A - On-bed state detection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an on-bed state detection device capable of estimating the position, movement and posture of a human body on a bed. <P>SOLUTION: The on-bed state detection device 20 is disposed on the bed 10. The on-bed state detection device 20 includes: a vibration detection part 30 for separately detecting a component of vibration applied to the bed 10 in the longitudinal direction of the bed 10 and a component of vibration in the direction perpendicular to the floor surface of the bed 10; a signal extraction part 40 for extracting heartbeat vibration signals originated from the heartbeat of the living body present on the bed 10 from the vibration detected by the vibration detection part 30; and a state estimation part 50 for estimating the posture of the living body on the bed 10 based on the heartbeat vibration signals extracted by the signal extraction part 40. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an in-situ state detection device that detects the position and posture of a person on a bed.

  Using the piezoelectric elements built in both sides of the bed, it detects the minute vibrations transmitted on the bed caused by human body movements and lie down on the bed, and fine body movements caused by heart beat and breathing. There is known a sleeping device that can know the position and movement of a human body without a human body on the sensor (see, for example, Patent Document 1).

Japanese Patent No. 2830661

  However, in the sleeping device of Patent Document 1, it is possible to know the position and movement of the human body, but it is not possible to determine the posture of the person, whether the person is sleeping on the bed or sitting. I can't know.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an in-situ state detection device capable of estimating a posture in addition to the position and movement of a human body.

  The first problem-solving means of the present invention separately detects a component along a longitudinal direction of the bed and a component along a vertical direction with respect to the floor surface of the bed, which is arranged on the bed and applied to the bed. Based on a vibration detection unit, a signal extraction unit that extracts a heartbeat vibration signal derived from a heartbeat of a living body existing on the bed from vibrations detected by the vibration detection unit, and the heartbeat vibration signal extracted by the signal extraction unit And a state estimation unit that estimates the posture of the living body on the bed.

  The second problem solving means of the present invention detects the position of the living body existing on the bed based on at least one of the intensity of the heartbeat vibration signal and the signal generation time extracted by the signal extraction unit. It is.

  According to the present invention, the vibration detection unit separately detects a component along the longitudinal direction of the vibration applied to the bed and a component along the vertical direction with respect to the floor surface of the bed, and the signal extraction unit is the vibration detection unit. A heartbeat vibration signal derived from the heartbeat of a living body (for example, a human body) existing on the bed is extracted from the vibration detected by. Therefore, the state estimation unit can estimate the movement of the position of the living body existing on the bed and the radial change of the position based on the heartbeat vibration signal extracted by the signal extraction unit. Furthermore, since the heartbeat vibration of a living body has a property along the longitudinal direction of the body (the direction from the head to the foot), the vibration component applied to the bed is perpendicular to the longitudinal direction of the bed and the bed surface. By detecting separately the components along, it is possible to detect the angle of the body of the living body with respect to the plane formed by the longitudinal direction of the bed and the vertical direction with respect to the floor surface. Since the angle of the trunk of the living body changes depending on whether the living body is in a sleeping state or a waking state, the posture of the living body can be estimated.

  Further, the state estimation unit can estimate the position of the living body existing on the bed with higher accuracy based on at least one of the signal generation time obtained from the intensity of the heartbeat vibration signal and the phase difference between the heartbeat vibration signals.

It is a perspective view which shows a bed provided with the in-bed state detection apparatus which concerns on an Example. It is a block diagram which shows the system configuration | structure of the occupancy state detection apparatus which concerns on an Example. It is explanatory drawing which divided the area | region of the floor surface of the bed into two in the longitudinal direction, and divided into three in the horizontal direction. It is a graph which shows the signal corresponding to the vibration along the longitudinal direction of the bed detected by the vibration detection part which concerns on an Example in a 1st state estimation example. It is a graph which shows the signal corresponding to the vibration along the perpendicular direction of the bed detected by the vibration detection part which concerns on an Example in a 1st state estimation example. It is explanatory drawing which shows the relationship between the magnitude relationship of the sum of the peak value detected by the load sensor, and the estimated position of a person. It is explanatory drawing which shows the relationship between the magnitude relationship of the sum of the peak value detected by the load sensor, and the estimated position of a person. It is explanatory drawing which shows the relationship between the magnitude relationship of the sum of peak value, and the estimated position of a person when the sum of the peak value detected by the load sensor is substantially equal. It is explanatory drawing which shows the state which exists in the posture which the person slept on the bed. It is a graph which shows the signal corresponding to the vibration along the longitudinal direction of the bed detected by the vibration detection part which concerns on an Example in a 2nd state estimation example. It is a graph which shows the signal corresponding to the vibration along the perpendicular direction of the bed detected by the vibration detection part which concerns on an Example in a 2nd state estimation example. It is explanatory drawing which shows the state which exists in the posture where the person sat on the bed. It is a block diagram which shows the occupancy state detection apparatus provided with the alerting | reporting means. It is explanatory drawing of calculation of the vibration generation position and generation time using the shift | offset | difference of the vibration arrival time to a load sensor.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view illustrating a bed 10 including a siding state detection device 20 according to an embodiment. The bed 10 provided with the occupancy state detection device 20 includes a bed frame 11, a mattress 12 placed on the bed frame 11, four legs 13 that support the bed frame 11 with respect to the floor, and a bed frame 11. And a headboard 14 provided on one side in the longitudinal direction.

  FIG. 2 is a block diagram illustrating a system configuration of the occupancy state detection device 20 according to the embodiment.

  The presence-of-floor state detection device 20 is arranged on the bed 10, and the component of the vibration of the place where the floor is located along the longitudinal direction of the bed 10 (Y direction in FIG. 1) and the vertical direction with respect to the floor surface of the bed 10 ( A plurality of vibration detection units 30 that separately detect components along the Z direction in FIG. 1, and a living body (particularly a human body, in this embodiment, an example of a human body) present on the bed 10 from vibrations detected by the vibration detection unit 30 And a signal extraction unit 40 for extracting a heartbeat vibration signal derived from the heartbeat of the heartbeat and a state (position, posture) of the living body on the bed 10 based on the heartbeat vibration signal extracted by the signal extraction unit 40. And a display unit 60 that displays the state (position, posture) of the person on the bed detected by the state estimation unit 50.

  As the vibration detection unit 30, a load sensor, an acceleration sensor, a piezoelectric element, a load cell, or the like can be used. In this embodiment, an example using a load sensor is shown. The load sensors are the first load sensor 31, the second load sensor 32, and the third load from the right side of the head side (headboard 14 side) to the left side (X direction in FIG. 1) in a state in which a person lies on his / her back on the bed 10. The load sensor 33 is arranged on the upper surface of the mattress 12 of the bed 10 in the order of the fourth load sensor 34, the fifth load sensor 35, and the sixth load sensor 36 from the right side of the foot side to the left side (X direction in FIG. 1). Has been. Each of the first load sensor 31 to the sixth load sensor 36 includes at least two detection shafts. The first detection axis is arranged in parallel to the longitudinal direction (Y direction in FIG. 1) of the bed 10, and the second detection axis is parallel to the vertical direction (Z direction in FIG. 1) with respect to the floor surface of the bed 10. Be placed.

  The first load sensor 31 to the sixth load sensor 36 are arranged on the bed 10 and detect vibrations at the arranged places. The vibration of the bed 10 is generated by the movement, breathing, heartbeat, etc. of a person existing on the bed 10. The position of the person is detected by utilizing the fact that the signal at the load sensor closer to the person existing on the bed 10 becomes stronger. When a person moves (turns over, sits down on the bed 10, etc.), the signals of the load sensors change in response to a load due to the weight of the person. When a person breathes, a force that pushes the bed 10 occurs when the person inhales and the lungs inflate, and the force sensor signal changes because the force relaxes when exhaling. From these signals, the position and state (breathing) of a person on the bed 10 can be examined.

  In addition to the movement of the person on the bed 10 and vibration caused by breathing, blood is pumped upward (head direction) by the heartbeat of the person, and when blood is pumped, it reacts downward The heart vibrates along the longitudinal direction of the human body (the direction from the head to the foot) by receiving force in the (foot direction), and this vibration is transmitted to the bed 10 through the human body. The vibration along the vertical direction of. When the person is sleeping along the longitudinal direction of the bed 10, vibrations in the longitudinal direction (Y direction in FIG. 1) are mainly transmitted to the bed 10 by the heartbeat, and the person sits on the bed 10. In the case of the above posture, vibration in the vertical direction (Z direction in FIG. 1) is mainly transmitted to the bed 10. Therefore, the posture of the person on the bed 10 can be examined by examining the direction of the heartbeat vibration transmitted to the bed 10.

  The signal extraction unit 40 is configured by a band pass filter. The bandpass filter extracts vibrations in a predetermined frequency band corresponding to a human heartbeat from the signals detected by the first load sensor 31 to the sixth load sensor 36.

  The state estimation unit 50 includes an electronic circuit, a microprocessor, a computer, and the like, and includes a program that performs an operation described later.

  The operation of the bed 10 provided with the occupancy state detection device 20 according to the embodiment will be described with reference to the drawings.

  FIG. 3 is an explanatory diagram in which the area of the floor surface of the bed 10 is divided into two in the longitudinal direction and three in the lateral direction. The state estimation unit 50 includes three regions a, b, and c divided in the horizontal direction (X direction in FIG. 1) of the bed 10 and two regions divided in the longitudinal direction of the bed 10 (Y direction in FIG. 1). It is estimated which area of the areas d and e has a person. Any of the areas of the floor surface of the bed 10 divided into six is specified by a combination of any of the areas a, b, and c and any of the areas d and e.

  FIG. 4 is a graph illustrating a signal corresponding to the vibration along the longitudinal direction of the bed 10 detected by the vibration detection unit 30 according to the example in the first state estimation example. FIG. 5 is a graph showing a signal corresponding to the vibration along the vertical direction of the bed 10 detected by the vibration detection unit 30 according to the example in the first state estimation example.

  The state estimating unit 50 calculates the average value ((P31 + P32 + P33 + P34 + P35 + P36) / 6) of the peak value of the heartbeat vibration signal (intensity) along the longitudinal direction of the bed 10 detected by the first load sensor 31 to the sixth load sensor 36. The value is the value in the Y direction) and the average value of the peak values of the heartbeat vibration signal along the vertical direction of the bed 10 ((P31 + P32 + P33 + P34 + P35 + P36) / 6, each peak value is a value in the Z direction). It is estimated that vibration is generated in the bed 10 along a direction larger than the other average value. As described above, since the heartbeat vibration vibrates along the longitudinal direction of the human body, when it is estimated that the vibration occurs along the longitudinal direction of the bed 10, the person on the bed 10 moves in the longitudinal direction of the bed 10. When it is estimated that the posture is sleeping along and it is estimated that vibration is generated along the vertical direction of the bed 10, it is estimated that the person on the bed 10 is sitting on the bed 10. .

  In order to estimate the direction of the heartbeat vibration, the average value of the peak value of the heartbeat vibration signal along the longitudinal direction of the bed 10 detected by the first load sensor 31 to the sixth load sensor 36 and the vertical direction of the bed 10 are described above. Although the average value of the peak values of the heartbeat vibration signal along the direction is used, these average values may be used as moving average values for a plurality of heartbeats.

  The state estimation unit 50 compares the peak values of the first load sensor 31 to the sixth load sensor 36 to estimate the presence position of the person on the bed. At this time, when it is estimated that the vibration is generated along the longitudinal direction of the bed 10, the vibration peak value along the longitudinal direction of the bed 10 is the vibration peak value along the vertical direction of the bed 10. When estimated, it estimates using the peak value of the vibration along the vertical direction of the bed 10.

  The state estimation unit 50 calculates the sum Sa of the peak value P31 of the first load sensor 31 and the peak value P34 of the fourth load sensor 34, the peak value P32 of the second load sensor 32, and the peak value P35 of the fifth load sensor 35. The sum Sb is compared. Next, the sum Sb of the peak value P32 of the second load sensor 32 and the peak value P35 of the fifth load sensor 35, the sum Sc of the peak value P33 of the third load sensor 33 and the peak value P36 of the sixth load sensor 36, Compare From this comparison result, the magnitude relationship of the sum Sa, the sum Sb, and the sum Sc is obtained.

  6 and 7 are explanatory diagrams showing the relationship between the magnitude relationship of the sum of the peak values detected by the first load sensor 31 to the sixth load sensor 36 and the estimated position of the person. As shown in FIG. 6, if Sa> Sb> Sc, Sa> Sb = Sc, the region a, Sa <Sb> Sc, Sa = Sb = Sc, the region b, Sa <Sb <Sc, Sa = Sb < If it is Sc, it is estimated that there is a person in the area c. As shown in FIG. 7, if Sa = Sb> Sc, it is estimated that a person exists near the boundary between the area a and the area b, and if Sa <Sb = Sc, a person exists near the boundary between the area b and the area c.

  FIG. 8 is an explanatory diagram showing the relationship between the peak sum and the estimated position of the person when the sum of the peak values detected by the first load sensor 31 to the sixth load sensor 36 is substantially equal. When comparing whether or not the peak values are equal, it is checked whether the ratio between the sums is within a predetermined range (for example, 90% to 110%). ≒). In this case, in addition to the comparison between Sa and Sb and Sb and Sc, the sum Sa of the peak value P31 of the first load sensor 31 and the peak value P34 of the fourth load sensor 34, and the peak value of the third load sensor 33 P33 and the sum Sc of the peak value P36 of the sixth load sensor 36 are further compared. When all of Sa≈Sb, Sb≈Sc, and Sa> Sc are satisfied, the area a is satisfied. When Sa≈Sb, Sb≈Sc, and Sa≈Sc are all satisfied, the area b is satisfied, Sa≈Sb, Sb≈Sc and When Sa <Sc is satisfied, it is estimated that a person exists in the region c.

  The state estimation unit 50 includes the sum Sd of the peak value P31 of the first load sensor 31, the peak value P32 of the second load sensor 32, and the peak value P33 of the third load sensor 33, the peak value P34 of the fourth load sensor 34, The sum Se of the peak value P35 of the fifth load sensor 35 and the peak value P36 of the sixth load sensor 36 is compared. From this comparison result, the magnitude relationship between the sum Sd and the sum Se is obtained.

  The state estimation unit 50 has a person in the area d if Sd> Se, in the area e if Sd <Se, and in the vicinity of the boundary between the area d and the area e if Sd = Se (or Sd≈Se). Estimated.

  An example of estimating the first state of a person on the bed by the in-bed state detecting device 20 according to the embodiment will be described with reference to the drawings.

  As a result of extracting the heartbeat vibration signal by the signal extraction unit 40 from the signals detected by the first load sensor 31 to the sixth load sensor 36 arranged on the bed 10, the longitudinal direction of the bed 10 (Y direction in FIG. 1). 4 and FIG. 5 in the vertical direction of the bed 10 (Z direction in FIG. 1). As described above, the state estimation unit 50 calculates the average value ((P31 + P32 + P33 + P34 + P35 + P36) / 6) of the peak value of the heartbeat vibration signal along the longitudinal direction of the bed 10 detected by the first load sensor 31 to the sixth load sensor 36. A value is a value in the Y direction) and an average value ((P31 + P32 + P33 + P34 + P35 + P36) / 6, each peak value is a value in the Z direction) of the heartbeat vibration signal along the vertical direction of the bed 10. As a result, since the average value of the peak value of the heartbeat vibration signal along the longitudinal direction of the bed 10 is larger than the average value of the peak value of the heartbeat vibration signal along the vertical direction of the bed 10, the state estimation unit 50 10 is estimated to be along the longitudinal direction of the bed 10, and it is estimated that the person is sleeping on the bed 10.

  Next, as described above, the state estimation unit 50 detects the sum Sa of the peak value P31 of the first load sensor 31 and the peak value P34 of the fourth load sensor 34 that have detected the heartbeat vibration signal along the longitudinal direction of the bed 10. The sum Sb of the peak value P32 of the second load sensor 32 and the peak value P35 of the fifth load sensor 35 and the sum Sc of the peak value P33 of the third load sensor 33 and the peak value P36 of the sixth load sensor 36 are obtained. , Compare each. As a result, since Sa <Sb and Sb> Sc, the state estimation unit 50 estimates that a person exists in the region b.

  Next, as described above, the state estimation unit 50 detects the heartbeat vibration signal along the longitudinal direction of the bed 10, the peak value P31 of the first load sensor 31, the peak value P32 of the second load sensor 32, and the third load. The sum Sd of the peak value P33 of the sensor 33, the sum Se of the peak value P34 of the fourth load sensor 34, the peak value P35 of the fifth load sensor 35, and the peak value P36 of the sixth load sensor 36 are obtained and compared. . As a result, since Sd≈Se, the state estimation unit 50 estimates that a person exists near the boundary between the region d and the region e.

  FIG. 9 is an explanatory diagram showing a state in which a person is lying on the bed 10. Since the person is sleeping on the bed 10 and exists in the region b and in the vicinity of the boundary between the region d and the region e, the state estimation unit 50 estimates the position and posture of the person as shown in FIG. To do. The presence position and posture of the person estimated by the state estimation unit 50 are displayed on the display unit 60.

  An example of detecting a second state of a person on the bed 10 by the in-bed state detecting device 20 according to the embodiment will be described with reference to the drawings.

  FIG. 10 is a graph showing signals corresponding to vibrations along the longitudinal direction of the bed 10 (Y direction in FIG. 1) detected by the vibration detection unit 30 according to the example in the second state estimation example. . FIG. 11 is a graph illustrating signals corresponding to vibrations along the vertical direction (Z direction in FIG. 1) of the bed 10 detected by the vibration detection unit 30 according to the example in the second state estimation example. .

  As a result of extracting the heartbeat vibration signal by the signal extraction unit 40 from the signals detected by the first load sensor 31 to the sixth load sensor 36 arranged on the bed 10, the longitudinal direction of the bed 10 is shown in FIG. The graph of FIG. 11 was obtained for the vertical direction. As described above, the state estimating unit 50 calculates the average value of the peak values of the heartbeat vibration signals detected by the first load sensor 31 to the sixth load sensor 36 along the longitudinal direction of the bed 10 ((P31 + P32 + P33 + P34 + P35 + P36) / 6, The peak value is a value in the Y direction) and the average value ((P31 + P32 + P33 + P34 + P35 + P36) / 6, each peak value is a value in the Z direction) of the heartbeat vibration signal along the vertical direction of the bed 10. As a result, since the average value of the peak value of the heartbeat vibration signal along the vertical direction of the bed 10 is larger than the average value of the peak value of the heartbeat vibration signal along the longitudinal direction of the bed 10, the state estimation unit 50 The heartbeat vibration transmitted to 10 is estimated to be along the vertical direction of the bed 10, and it is estimated that the person is sitting on the bed 10.

  Next, as described above, the state estimation unit 50 detects the sum Sa of the peak value P31 of the first load sensor 31 and the peak value P34 of the fourth load sensor 34 that have detected the heartbeat vibration signal along the longitudinal direction of the bed 10. The sum Sb of the peak value P32 of the second load sensor 32 and the peak value P35 of the fifth load sensor 35 and the sum Sc of the peak value P33 of the third load sensor 33 and the peak value P36 of the sixth load sensor 36 are obtained. , Compare each. As a result, since Sa> Sb and Sb> Sc, the state estimation unit 50 estimates that a person exists in the region a.

  Next, as described above, the state estimation unit 50 detects the heartbeat vibration signal along the longitudinal direction of the bed 10, the peak value P31 of the first load sensor 31, the peak value P32 of the second load sensor 32, and the third load. The sum Se of the peak value P33 of the sensor 33, the peak value P34 of the fourth load sensor 34, the peak value P35 of the fifth load sensor 35 and the peak value P36 of the sixth load sensor 36 is obtained, Compare. As a result, since Sd <Se, the state estimation unit 50 estimates that a person exists in the region e.

  FIG. 12 is an explanatory diagram showing a state in which a person is sitting on the bed 10. Since the person is sitting in the bed 10 and exists in the region a and the region e, the state estimation unit 50 estimates the presence position and posture of the person as shown in FIG. The presence position and posture of the person estimated by the state estimation unit 50 are displayed on the display unit 60.

  As described above, according to the occupancy state detection device 20 according to the embodiment, the position and posture of a living body (particularly a human body) can be detected. In particular, since it is possible to detect that the person is in the posture of sitting on the end of the bed, it is possible to contribute to the improvement of safety when the person stands up from the posture of sitting on the end of the bed.

  FIG. 13 is a block diagram showing the occupancy state detection device 20 provided with the notification means 70. In addition to the configuration of the above embodiment, a notification means 70 for notifying when a predetermined posture is detected is provided, for example, detecting and notifying that a person is sitting on the end of the bed and receiving the notification. It may be configured such that a caregiver or the like can go to the person for assistance.

  Although six load sensors are provided in the above embodiment, the position of the vibration source can be estimated by providing at least three load sensors.

  In the above embodiment, the load sensor is provided on the upper surface of the mattress 12 of the bed 10. However, the load sensor is not limited thereto, and the foot provided on the lower surface of the mattress 12, the upper surface of the bed frame 11, and the bed frame 11. 13 may be provided on the lower surface of 13 and the back surface of the bed frame 11. When the load sensor is arranged on the upper surface of the mattress 12 of the bed 10, there is an advantage that vibration transmitted to the load sensor is increased, but there is a possibility that a person sleeping on the bed 10 may feel uncomfortable. When the load sensor is arranged in the mattress 12, there is an advantage that does not give the person a sense of incongruity, but the arrangement is difficult and there is a possibility that it is difficult to retrofit. When the load sensor is disposed on the lower surface of the mattress 12, there is an advantage that the person on the bed 10 does not feel uncomfortable, but there is a risk that vibration transmitted to the load sensor is smaller than when the load sensor is provided on the upper surface of the mattress 12. . When the load sensor is arranged on the upper surface of the bed frame 11 and on the back surface of the bed frame 11, there is an advantage that the person on the bed 10 does not give a sense of incongruity and is easy to be retrofitted, but vibration transmitted to the load sensor is not affected. There are disadvantages such as being difficult to install on a bed frame having a ventilation hole or a net-like bed frame, which is smaller than the case of being provided on the upper surface of the bed. When the load sensor is disposed on the lower surface of the foot 13 provided on the bed frame 11, it can be retrofitted to any bed with a foot, and there is an advantage that the person who sleeps on the bed does not feel uncomfortable. Even if the posture can be detected, it may be difficult to detect the position. The placement location of the floor presence detection apparatus 20 of the present embodiment is arbitrary, and an appropriate placement location can be selected according to the situation in consideration of the above advantages and disadvantages.

  In the above embodiment, the state estimation unit 50 detects the position using the peak value of the signal of the load sensor, but instead of or in addition to the load sensor, the state estimation unit 50 applies the load to each of the load sensors arranged in at least three locations. The position of the vibration source of the heartbeat vibration may be obtained from the deviation (phase difference) of the vibration arrival time. In this method, since the heartbeat vibration propagates from the heartbeat vibration source on the bed 10 at a constant velocity V (assuming propagation of vibration on the rigid body), the longer the distance to the load sensor, the later it reaches the load sensor. Take advantage of that. Even in this method, the state estimation unit 50 can estimate the presence position of the person on the bed 10.

FIG. 14 is an explanatory diagram of the calculation of the vibration generation position and generation time using the deviation of the vibration arrival time to the load sensor. In order to obtain the vibration source position and the vibration occurrence time using the deviation of the vibration arrival time to the load sensors arranged at three locations, the following is performed. The first load sensor is arranged at the position coordinates (x1, y1), the second load sensor is arranged at the position coordinates (x2, y2), and the third load sensor is arranged at the position coordinates (x3, y3), respectively, at times t1, t2, It is assumed that vibration is detected at t3. Assuming that the heartbeat vibration generation time is t0 and the vibration source position is (x0, y0), the distance d1 from the first load sensor to the heartbeat vibration source, the distance d2 from the second load sensor to the heartbeat vibration source, The distance d3 from the third load sensor to the heartbeat vibration source is given by the following equation. From these three simultaneous equations, three unknown variables x0, y0, t0 can be obtained.

  Thereby, the state estimation unit 50 more accurately determines the position of the living body on the bed 10 based on at least one of the signal generation time obtained from the intensity of the heartbeat vibration signal and the phase difference between the heartbeat vibration signals. Can be estimated.

10 bed 20 occupancy state detection device 30 vibration detection unit 40 signal extraction unit 50 state estimation unit

Claims (2)

A vibration detection unit that is disposed on the bed and separately detects a component along the longitudinal direction of the bed and a component along the vertical direction with respect to the floor surface of the bed;
A signal extraction unit for extracting a heartbeat vibration signal derived from a heartbeat of a living body existing on the bed from the vibration detected by the vibration detection unit;
A bed state detection device comprising: a state estimation unit that estimates the posture of the living body on the bed based on the heartbeat vibration signal extracted by the signal extraction unit. The said state estimation part detects the position of the said biological body which exists on the said bed based on at least any one of the intensity | strength of the said heartbeat vibration signal and the signal generation time which the said signal extraction part extracted. Item 3. A bed-state detection device according to item 1.

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