JP2016019649A - Bed occupancy state detection method and bed occupancy state detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bed occupancy state detection method capable of suppressing a wasteful alarm such as an alarm for sitting up.SOLUTION: A detection method includes: a preliminary bed-leaving movement alarm step for issuing a preliminary bed-leaving movement alarm when it is determined that a user U makes a preliminary bed-leaving movement (e.g., a sitting-up movement) on a bed 30; a state determination step for determining whether or not the movement of the user U is in a stable state after the alarm is issued, and whether or not the user U carries out a return movement from a state of the preliminary bed-leaving movement to a state of lying on a bed; and a bed-leaving movement determination step for determining whether or not the user U carries out a bed-leaving movement when it is determined in the state determination step that the movement of the user U is not in a stable state, and that the user does not carry out a return movement. When it is determined in the bed-leaving movement determination step that the user does not carry out a bed-leaving movement, the flow returns to the state determination step.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a bed occupancy status detection method and a bed occupancy status detection device for detecting the occupancy status of a bed user lying on a bed.

  Several methods are known as methods for detecting the presence of a bed user (e.g., elderly, sick, healthy) who are lying on the bed (eg, Patent Documents 1 to 7). The basic configuration is as follows.

  That is, the loads applied to the head right side, head left left, foot right right and foot left left of the bed are respectively detected by the first to fourth load detection sensors, and the output values (loads) from these load detection sensors are detected. Value) to detect the presence of the user on the bed. If it is detected that the user has moved out of bed on the bed, information to that effect is notified to the caregiver by an alarm or the like. The informed caregiver can go to the user for assistance (including care) of the user who has performed the bed leaving operation.

  In such a detection method, when the user on the bed starts the bed leaving operation, the user usually starts up as a bed leaving preliminary operation before that. Therefore, in order to detect the user's getting-off motion at an early stage, it is desirable to be able to detect the user's rising motion. Note that the user's rising action means an action in which the user raises his / her upper body, which is also referred to as “back raising action” or “upper body raising action”.

  The basic method for determining (detecting) the rising motion by the detection device is as follows. That is, the head-side output value (head-side load value), which is the sum of the output values (load values) from the two load detection sensors that detect the load applied to the head-side right part and head-side left part of the bed, is usually It is reduced by the user's rising motion. Therefore, in the conventional detection device, when the amount of decrease in the head-side output value is equal to or greater than a predetermined threshold, it is determined (detected) that the user has started up, and the user is informed that the user has started up. A rising alarm is issued as a preliminary operation alarm for leaving the bed.

JP 2000-316915 A JP 2007-190269 A JP 2006-305343 A JP 2007-175208 A JP 2007-330658 A JP 2007-330689 A JP 2011-67247 A

  However, the conventional detection apparatus has the following problems.

  In other words, a user who has been laid on the bed may hang down to the foot side of the bed while sleeping, or may be lowered by the caregiver to the foot side of the bed for care to the user. Often there is to do. In this case, if the head-side output value decreases and the amount of decrease is equal to or greater than a predetermined threshold, it is erroneously determined that the user has performed a rising motion even though the user has not actually performed the rising motion, After that, there is a problem that even if the user performs a real rising motion, the rising motion cannot be determined.

  In order to prevent such erroneous determination of the rising motion caused by the user's sliding down, the present inventors have determined a predetermined time (for example, about 20 seconds) from the time when the user has determined that the rising motion has been performed. The detection device is configured such that the determination is forcibly reset when the time has elapsed, and the user is assumed not to be in the rising motion (that is, the user is not in the raised state but in the bedded state).

  However, this detection device has the following problems.

  In other words, after the user gets up on the bed, he / she does not get out of bed, and has a long life on the bed (for example, folding the laundry, changing the futon, changing clothes, organizing work for daily items, etc.) Even if the judgment is forcibly reset based on the elapsed time from the judgment time of the start-up action, for example, when it is over time, the amount of decrease in the head side output value caused by the living action after that When the value exceeds a predetermined threshold value, the rising alarm is issued again, and as a result, the number of rising alarms increases. Therefore, when a rising alarm is issued, there is a problem that it becomes a burden on a caregiver who has to go to the user.

  The present invention has been made in view of the above-described technical background, and an object of the present invention is to detect a bed occupancy state and a bed occupancy state detection capable of suppressing unnecessary generation of an alarm such as a rising alarm. To provide an apparatus.

  The present invention provides the following means.

[1] A load detection step of detecting a load applied to the bed on which the bed user has been laid down by a load detection means at a predetermined detection cycle;
A bed leaving preliminary operation determining step for determining whether or not the user has performed a bed leaving preliminary operation on the bed based on an output value from the load detecting means,
When it is determined that the user has performed a preliminary bed leaving operation in the preliminary bed leaving operation determining step, a bed leaving preliminary operation alarm step for issuing a bed leaving preliminary operation alarm; and
After issuing the bed leaving preliminary operation alarm, it is determined whether or not the user's operation on the bed is in a stable state based on the output value from the load detection means, and the user leaves the bed on the bed. A state determination step of determining whether or not a return operation of returning from the preliminary operation state to the bedrock state has been performed;
When it is determined in the state determination step that the user's operation is not in a stable state and the user determines that the return operation is not performed, the user performs a bed leaving operation based on an output value from the load detection means. A step of determining whether to get out of bed,
When it is determined that the user has made a bed-moving operation in the bed-moving operation determination step, a bed-moving operation alarm step for issuing a bed-moving operation alarm is included.
The bed occupancy status detection method, wherein when the user determines that the user is not performing a bed leaving operation in the bed leaving operation determining step, the process returns to the state determining step.

[2] The bed leaving operation determining step includes:
An endmost area determination step of determining whether or not the position of the center of gravity of the user on the bed calculated based on the output value from the load detection means exists in the endmost area of the bed;
When it is determined in the extreme end area determination step that the user's center of gravity exists within the extreme end area, the current time is determined from the time when the preliminary release operation determination step is determined by the user to perform the preliminary release operation. An elapsed time determination step for determining whether or not the elapsed time up to β hours (where β> 0) or more,
When it is determined that the elapsed time is equal to or longer than the β time in the elapsed time determination step, an endmost alarm step of issuing an endmost alarm as one of the bed leaving operation alarms;
The output value from the load detecting means in each of the case where the elapsed time is determined not to be equal to or longer than the β time in the elapsed time determination step and the case where the endmost alarm is issued in the endmost alarm step. A step of determining whether or not the user on the bed has left the bed based on
When it is determined that the user has left the floor in the bed leaving determination step, a bed leaving alarm step for issuing a bed leaving alarm as one of the bed moving operation alarms is provided.
In each of the case where it is determined that the center of gravity position of the user does not exist in the endmost area in the endmost area determination step and the case where it is determined that the user has not left the floor in the step-out determination step. The bed occupancy state detection method according to item 1, wherein the user determines that the user is not moving out of the bed and returns to the state determination step.

[3] The load detection means includes first to fourth load detection sensors that respectively detect loads applied to a head right side, a head left side, a foot right side, and a foot side left part of the bed on which the user is bedded. With
In the state determination step, the first to fourth of the current time with respect to the output values from the first to fourth load detection sensors when it is determined that the user has performed a preliminary bed leaving operation in the preliminary bed leaving operation determining step. When the fluctuation rate of the output value from the load detection sensor is within ± α% and the stable condition that the state continues for t1 time (where t1> 0) is satisfied, the user's When it is determined that the operation is in a stable state, and at least one of the fluctuation rates of the output values from the first to fourth load detection sensors does not satisfy the stability condition, the user's operation is in a stable state. 3. The bed occupancy status detection method according to item 1 or 2 described above, which is determined to be not.

  [4] The state determination step corresponds to a head-side output value obtained by summing output values from the first and second load detection sensors when it is determined that the user has performed a preliminary bed removal operation in the preliminary bed removal operation determination step. The sum of the rate of increase of the head side output value at the current time and the output values from the third and fourth load detection sensors when it is determined that the user has performed a preliminary bed leaving operation in the preliminary bed leaving movement determination step. At least one of the decrease rate of the foot output value at the current time with respect to the side output value is within λ% (provided that λ ≧ 0) and the state continues for t2 hours (where t2> 0) or more. When the return operation condition is satisfied, it is determined that the user has performed the return operation. On the other hand, both the increase rate of the head side output value and the decrease rate of the foot side output value are the return operation condition. If the user does not satisfy Not the determined preceding 3 beds the bed status detecting method as claimed.

[5] A load detecting means for detecting a load applied to the bed on which the bed user has been laid down at a predetermined detection cycle;
A bed leaving preliminary operation determining unit that determines whether or not the user has performed a bed leaving preliminary operation on the bed based on an output value from the load detecting unit;
When it is determined that the user has performed a preliminary bed leaving operation by the preliminary bed leaving operation determining means, a bed leaving preliminary operation alarm means for issuing a bed leaving preliminary operation alarm; and
After issuing the bed leaving preliminary operation alarm, it is determined whether or not the user's operation on the bed is in a stable state based on the output value from the load detection means, and the user leaves the bed on the bed. State determination means for determining whether or not a return operation of returning from the preliminary operation state to the bedside state has been performed;
When it is determined by the state determination means that the user's operation is not in a stable state and the user determines that the return operation is not performed, the user performs a bed leaving operation based on an output value from the load detection means. Leaving motion determining means for determining whether or not
A bed movement alarm means for issuing a bed movement alarm when it is determined by the bed movement determination means that the user has made a bed movement;
The bed occupancy status detection apparatus is configured to execute the state determination unit again when it is determined by the bed movement determination unit that the user is not performing a bed leaving operation.

[6] The bed leaving movement determination means includes
An endmost area determination means for determining whether or not the position of the center of gravity of the user on the bed calculated based on the output value from the load detection means exists in the endmost area of the bed;
When it is determined by the endmost area determination means that the position of the center of gravity of the user is present in the endmost area, the current time is determined from the time at which the user has made a preliminary bed leaving operation by the preliminary bed leaving action determination means. Elapsed time determination means for determining whether or not the elapsed time up to β hours (where β> 0) or more,
When the elapsed time determining means determines that the elapsed time is equal to or greater than the β time, an endmost alarm means for issuing an endmost alarm as one of the bed leaving movement alarms;
The output value from the load detection means in each of the case where the elapsed time determination means determines that the elapsed time is not greater than the β time and the case where the extreme end alarm means issues the extreme end alarm. A bed determining means for determining whether or not the user on the bed has left the bed based on
A bed alarm means for issuing a bed alarm as one of the bed movement alarms when it is determined that the user has left the bed using the bed determination means;
In each of the case where it is determined that the position of the center of gravity of the user does not exist in the endmost area by the endmost area determination unit and the case where the user determines that the user has not left the floor by the bed leaving determination unit. 6. The bed occupancy state detection device according to item 5 above, wherein the bed state detection device is configured to determine that the user is not performing a bed leaving operation and to execute the state determination unit again.

[7] The load detection means includes first to fourth load detection sensors for detecting loads applied to the head right side, the head left side, the foot right side, and the foot left side of the bed on which the user is bedded. With
The state determination means is the first to fourth of the current time with respect to the output values from the first to fourth load detection sensors when it is determined by the preliminary movement preliminary movement determination means that the user has performed preliminary bed movement. When the fluctuation rate of the output value from the load detection sensor is within ± α% and the stable condition that the state continues for t1 time (where t1> 0) is satisfied, the user's When it is determined that the operation is in a stable state, and at least one of the fluctuation rates of the output values from the first to fourth load detection sensors does not satisfy the stability condition, the user's operation is in a stable state. 7. The bed occupancy status detection device according to 5 or 6 above, which is determined not to be.

  [8] The state determination means corresponds to a head-side output value obtained by summing up the output values from the first and second load detection sensors when it is determined that the user has made a bed leaving preliminary movement by the bed leaving preliminary movement determination means. The sum of the rate of increase of the head-side output value at the current time and the output values from the third and fourth load detection sensors when it is determined by the preliminary bed leaving movement determination means that the user has performed the bed leaving preliminary movement. At least one of the decrease rate of the foot output value at the current time with respect to the side output value is within λ% (provided that λ ≧ 0) and the state continues for t2 hours (where t2> 0) or more. When the return operation condition is satisfied, it is determined that the user has performed the return operation. On the other hand, both the increase rate of the head side output value and the decrease rate of the foot side output value are the return operation condition. If the user does not satisfy Though not the determining beds the bed status detecting apparatus of the preceding paragraph 7, wherein.

  The present invention has the following effects.

  According to the detection method of the preceding paragraph [1], the state determination step determines whether or not the user's operation on the bed is in a stable state, and the user changes from the bed leaving preliminary operation state to the bedside state on the bed. When it is determined whether or not the return motion has been performed, and the bed leaving motion determination step determines that the user's motion is not in a stable state in the state determination step and determines that the user is not performing the return motion Next, it is determined whether or not the user has moved out of bed.

  Therefore, a user who has performed a preliminary bed leaving operation (eg, a rising motion) on the bed does not leave the floor in a preliminary motion leaving state (eg, a rising motion) and does not leave the bed for a long time. If it is, it is determined in the state determination step that the user's operation is not in a stable state and it is determined that the user is not performing a return operation, and the process proceeds to the bed leaving operation determination step. When it is determined that the user is not performing a bed leaving operation in this bed leaving operation determining step, the process returns to the state determining step instead of the bed leaving preliminary operation determining step, so that a bed leaving preliminary operation alarm (eg, a rising alarm) is issued. This will reduce the number of occurrences of the preliminary bed leaving alarm. Accordingly, it is possible to suppress unnecessary occurrence of the bed leaving operation alarm such as a rising alarm, and as a result, the burden on the caregiver is reduced.

  According to [2] in the previous section, when the user performs a bed leaving action after performing a bed leaving preliminary action (eg, a rising action) on the bed, the bed leaving preliminary action is performed and the life action is performed. When the user who has been moved to the endmost area of the bed to get out of the bed, it is determined in the endmost area determination step that the position of the center of gravity of the user exists in the endmost area, and the process proceeds to the elapsed time determination step. At this time, from the time when it was determined that the user performed a bed leaving preliminary operation to the time when the user's center of gravity position was determined to be within the endmost area in the endmost area determination step, because the user was performing daily activities The elapsed time is long. As a result, in the elapsed time determination process, it is determined that the elapsed time is equal to or more than β hours, and the process proceeds to the endmost alarm process and an endmost alarm is issued. And it progresses to a bed leaving determination process, and when it determines with the user having left the bed in this bed leaving determination process, a bed leaving alarm is emitted in a bed leaving alarm process.

  On the other hand, when the user performs a bed leaving operation immediately after performing a bed leaving operation on the bed without performing the living operation, that is, the user performs the bed leaving operation and the bed leaving operation in a series of operations without using the living operation. In this case, when the user who has performed the bed leaving movement moves to the endmost area of the bed, the position of the center of gravity of the user is determined to exist within the endmost area in the endmost area determination step, and the process proceeds to the elapsed time determination step. . At this time, since the user was not performing daily activities, the time when the user's center of gravity position was determined to be within the extreme area in the extreme area determination step from the time when the user determined that the preliminary bed movement was performed The elapsed time until is short. As a result, in the elapsed time determination process, it is determined that the elapsed time is not more than β hours, and the process proceeds to the bed leaving determination process instead of the extreme alarm process. Therefore, the most extreme alarm is not issued. When it is determined that the user has left the floor in the bed leaving determination step, a bed leaving alarm is issued in the bed leaving alarm step. Here, when the user performs the bed leaving operation and the bed leaving operation in a series of actions as described above, the bed leaving alarm is issued from the time when the user determines that the bed leaving preliminary operation is performed and issues the bed leaving preliminary operation alarm. The elapsed time until is short, and it is not necessary to issue an extreme alarm. For this reason, when proceeding from the elapsed time determination step to the bed leaving determination step, the extreme alarm step is omitted. Thereby, unnecessary generation | occurrence | production of the most extreme alarm can be suppressed and the caregiver's burden can further be reduced.

  According to the previous item [3], it is possible to easily and reliably determine whether or not the user's operation is in a stable state in the state determination step.

  According to the preceding item [4], it is possible to easily and reliably determine whether or not the user has performed a return operation in the state determination step.

  The detection devices [5] to [8] in the previous section can reliably execute the detection methods [1] to [4].

FIG. 1 is a schematic diagram illustrating a bed occupancy state detection device according to an embodiment of the present invention. FIG. 2 is a schematic plan view of the bed. FIG. 3 is a block diagram showing the configuration of the detection apparatus. FIG. 4 is a flowchart showing the operation of the detection apparatus.

  Next, an embodiment of the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, a bed occupancy status detection device 20 according to an embodiment of the present invention detects the occupancy status of a bed user U on a bed 30. Examples of the occupancy status include bed rest, preliminary leaving operation, leaving operation, the center of gravity G of the user U on the bed 30, the amount of movement, and the like.

  The bed 30 is used in medical facilities (eg, hospitals), elderly facilities, nursing homes, general households, etc., and is generally installed on a floor surface 35 in a room such as a bedroom (including a hospital room). It is what is done. The bed 30 has a planar shape (a rectangular shape in detail) (see FIG. 2). Then, the bed 30 is formed in a substantially horizontal shape from below by the head-side right leg 31a, the head-side left leg 31b, the foot-side right leg 31c, and the foot-side left leg 31d as the four legs of the bed 30. It is supported so as to be separated from the surface 35. A bed moving caster for allowing the bed 30 to smoothly move on the floor surface 35 is provided in a fixed state at the lower end of each leg. A bed user U lays on the bed 30 for the purpose of going to bed.

  Examples of the user U include elderly people, sick people (including persons with disabilities), healthy people, and the like. In the present embodiment, it is assumed that the user U is a person (care recipient) who needs care, such as an elderly person or a sick person. In addition, various alarms such as a bed leaving operation alarm (rising alarm) and a bed leaving alarm are provided to a caregiver (e.g. nurse, user U's family and relatives) who provides care to the user U (including assistance). It shall be issued against.

  A headboard 32 a is provided at the head side edge of the bed 30 so as to rise from the upper surface of the bed 30, and a footboard 32 b is provided at the foot side edge of the bed 30 with respect to the upper surface of the bed 30. It is provided in a rising shape.

  Further, in the present embodiment, as shown in FIG. 2, the right side, the left side, and the head side of the user U in a state where the user U is lying on the bed 30 in a lying posture (that is, a posture lying on his back). The foot side is referred to as the right side, the left side, the head side, and the foot side of the bed 30, respectively.

  In the present embodiment, the preliminary bed leaving operation performed by the user U on the bed 30 will be described below as a rising operation. The raising operation means an operation in which the user U raises his / her upper body, and is also called “back raising operation” or “upper body raising operation”.

  As shown in FIG. 1, the detection device 20 of the present embodiment includes a load detection unit 1, a control unit 2, and the like.

  The load detection means 1 detects a load applied to the bed 30 on which the user U is bedded in a predetermined detection cycle, and includes four first to fourth load detection sensors 1a to 1d. Each of the load detection sensors 1a to 1d is, for example, a known load cell type, and is disclosed in Japanese Patent Application Laid-Open Nos. 2006-302266, 2007-167492, 2008-12202, and the like. And arranged between the leg portions 31 a to 31 d of the bed 30 and the floor surface 35. In these load detection sensors 1 a to 1 d, the load detection sensor 1 a (referred to as “first load detection sensor 1 a”) disposed between the head-side right leg 31 a and the floor surface 35 is the head of the bed 30. A load applied to the right side portion (specifically, the right end portion on the head side) is detected. A load detection sensor 1b (referred to as “second load detection sensor 1b”) disposed between the head-side left leg portion 31b and the floor surface 35 is a head-side left portion of the bed 30 (specifically, the head-side left end). Part) is detected. A load detection sensor 1c (referred to as "third load detection sensor 1c") disposed between the foot side right leg portion 31c and the floor surface 35 is a foot side right portion of the bed 30 (specifically, the foot side right end). Part) is detected. A load detection sensor 1d (referred to as “fourth load detection sensor 1d”) disposed between the foot side left leg portion 31d and the floor surface 35 is a foot side left portion of the bed 30 (more specifically, the foot side left end). Part) is detected.

  These load detection sensors 1a to 1d have the same configuration, and the corresponding leg portions of the bed 30 are placed on the load receiving surface provided on the upper surface of each load detection sensor. The load applied to the portion to be detected is detected at a predetermined detection cycle. And from each load detection sensor 1a-1d, the load value corresponding to the load concerning the part which the bed 30 respond | corresponds is output for every detection period of a load detection sensor as an output value. That is, from the first load detection sensor 1a, a load value corresponding to a load applied to the right side of the head of the bed 30 is output as an output value for each detection cycle. From the second load detection sensor 1b, a load value corresponding to the load applied to the left side of the head side of the bed 30 is output as an output value for each detection cycle. From the third load detection sensor 1c, a load value corresponding to a load applied to the right side of the foot 30 of the bed 30 is output as an output value for each detection cycle. From the 4th load detection sensor 1d, the load value corresponding to the load applied to the foot side left part of the bed 30 is output as an output value for every detection period.

  Here, in the present invention, the detection cycle of the load detection sensor is not limited, but is preferably set in the range of 0.005 seconds to 1 second. In the present embodiment, the detection cycle is, for example, 0.5 seconds.

  Output values from the load detection sensors 1a to 1d are transmitted to the control means 2 via the wired communication means (or wireless communication means) for each detection period of the load detection sensor. In the present embodiment, the output value from each of the load detection sensors 1a to 1d is a load value, and its unit is, for example, “kgf”.

  As shown in FIG. 2, the output value from the first load detection sensor 1a is W1, the output value from the second load detection sensor 1b is W2, the output value from the third load detection sensor 1c is W3, and the fourth The output value from the load detection sensor 1d is set to W4. Here, W1 to W4 are preferably values obtained by subtracting the weight of the bed 30 as a tare value, that is, values that are tared. The tare processing is performed by the control means 2 or the tare processing means (not shown) provided in each of the load detection sensors 1a to 1d. In this embodiment, it is assumed that W1 to W4 are tared values.

  The control means 2 comprises a controller equipped with a computer having ROM, RAM, CPU, etc., and as shown in FIG. 3, the rising operation as the output value data storage means 3 and the leaving bed preliminary action determination means 4 It includes a determination means 4A, a rising alarm means 5A as a leaving bed preliminary operation alarm means 5, a state determination means 6, a leaving action determination means 9, and the like. The computer is preinstalled with a predetermined program for executing predetermined determination, calculation (calculation), control, and the like necessary for detecting the presence of the user U on the bed 30. The control means 2 is usually installed in the vicinity of the bed 30 or in a caregiver's stuffing station, mounted on various servers, or mounted on a multi-function terminal (eg, mobile phone, smartphone, tablet terminal). Or

  The output value data storage means 3 includes the output values W1 to W4, the head side output value H, the foot side output value F, the total output value WT, the variation rate of each output value, and the gravity center position G of the user U on the bed 30. Data required for predetermined judgment, calculation (calculation), control, etc. (this is called “output value data”) is calculated for each detection cycle of the load detection sensor, and from each load detection sensor as necessary Is stored in association with the output time (detection time).

  The total output value WT means the sum of the output values W1 to W4 from the first to fourth load detection sensors 1a to 1d, that is, WT = W1 + W2 + W3 + W4.

  The gravity center position G (GX, GY) of the user U on the bed 30 is calculated using the output values W1 to W4 from the first to fourth load detection sensors 1a to 1d. For example, the following equations (1X) and ( 1Y). Note that O (0, 0) in FIG. 2 indicates the origin of the XY orthogonal coordinates that define the gravity center position G of the user U. Further, the length direction of the bed 30 is defined as the X-axis direction, and the width direction of the bed 30 (that is, the left-right direction of the bed) is defined as the Y-axis direction.

GX = (W1 + W2-W3-W4) × (1 / WT) × (BX / 2) Equation (1X)
GY = (W1 + W3-W2-W4) × (1 / WT) × (BY / 2) Expression (1Y)
However,
BX: Leg spacing in the length direction (ie, X-axis direction) of the bed 30 BY: Leg spacing in the width direction (ie, Y-axis direction) of the bed 30

  The head-side output value H is a value obtained by summing the output values W1 and W2 from the first and second load detection sensors 1a and 1b. The foot side output value F is a value obtained by summing the output values W3 and W4 from the third and fourth load detection sensors 1c and 1d. That is, H and F are calculated by the following equations (2) and (3), respectively.

Head side output value H = W1 + W2 Formula (2)
Foot side output value F = W3 + W4 Formula (3).

  Here, in the bed 30 shown in FIG. 2, the center portion of the bed 30 is an area (bedbed area) where the center of gravity G of the user U is normally present when the bed is placed. In the present embodiment, the area adjacent to the left and right end sides Q0 of the bed 30 in the left and right end sides of the center portion of the bed 30 is referred to as the “most end area 30A (indicated by dot hatching)”. An area adjacent to each endmost area 30A on the bed center side side (that is, an area between the endmost area 30A and the bed center) is referred to as an “endmost area 30B (indicated by cross-hatching)”. In other words, the “most end area 30 </ b> A” is an area from the left and right end sides Q <b> 0 of the bed 30 to the first set position Q <b> 1 that is a predetermined distance away from the center of the bed, and the “endmost area 30 </ b> B”. This is an area from each first setting position Q1 to a second setting position Q2 that is a predetermined distance away from the bed center side.

  The outermost area 30 </ b> A is an area where the user U has a high risk of falling from the bed 30.

  The near end area 30 </ b> B is an area where there is a high possibility that the gravity center position G of the user U in the end sitting position exists. The end sitting state is a state in which the user U in the upright state sits on the end of the bed 30. In this embodiment, the user U in the end sitting state places his sole on the floor 35. It is assumed that it is not worn.

  As for the range of coordinates corresponding to the central portion of the bed 30, each endmost area 30 </ b> A and each endmost area 30 </ b> B, a caregiver or the like is stored in a predetermined storage unit (not shown) provided in the control means 2. It is preset and stored so that it can be arbitrarily changed.

  The rising motion determining means 4A (premature bed leaving motion determining means 4) is configured so that the user U starts as a preliminary bed leaving motion on the bed 30 based on the output values W1 to W4 from the first to fourth load detection sensors 1a to 1d. It is determined whether or not an upward movement has been performed.

  The rising alarm means 5A (leaving preliminary action alarm means 5), when it is determined by the rising action determining means 4A that the user U has taken a rising action (preliminary leaving action), the rising alarm is issued as a preliminary leaving action alarm. It is issued to a caregiver as a notification target person and has a speaker or the like. The rising alarm means 5A is configured so that the alarm is automatically stopped when a predetermined time has elapsed from when the alarm is issued, and a caregiver or the like performs an alarm stop operation (eg, alarm) The alarm is forcibly stopped by pressing a stop button (not shown).

  Further, the rising alarm means 5A is configured to issue a rising alarm as soon as possible when the rising action determining means 4A determines that the user U has made a rising action (preliminary leaving action). Yes. Therefore, the time lag between the determination time of the rising motion by the rising motion determining means 4A and the time of occurrence of the rising alarm by the rising alarm means 5A is very small, and both times are the same time. You can catch it.

  The determination method by the rising motion determination means 4A is performed by, for example, a known method, and the basic determination method is, for example, as follows.

  That is, the determination method is to determine whether or not the decrease rate or decrease amount of the head-side output value at the current time (current time) with respect to the determination reference value of the head-side output value is greater than or equal to a predetermined threshold value. It is determined (detected) that the user U has started up when it is determined that the rate or amount of decrease in the head-side output value is greater than or equal to a predetermined threshold, while the head-side output value is decreased at the current time. This is a method of determining (detecting) that the user U is not performing a rising motion when it is determined that the rate or the decrease amount is not equal to or greater than a predetermined threshold.

  As the determination reference value of the head-side output value, a head-side output value a predetermined time before the current time, a head-side output value when the user U rests on the bed 30, or the like is employed.

  In particular, in this embodiment, the determination method by the rising motion determination means 4A is performed as follows.

  That is, the determination method is to determine whether or not at least one of the predetermined first condition and the predetermined second condition is satisfied, and when the user U determines that at least one is satisfied, When it is determined (detected) that the rising motion has been performed, and it is determined that neither the first condition nor the second condition is satisfied, it is determined (detected) that the user U has not performed the rising motion. To do.

  The first condition is a condition that the state in which the rate of decrease of the head-side output value at the current time with respect to the head-side output value one hour before τ from the current time is ε1 or more continues for μ1 hours or more. However, τ1, ε1, and μ1 are 0 <τ1, 0 <ε1, and 0 <μ1, respectively.

  Here, in the first condition, the head side output value at the current time is H0, the head side output value before τ1 hour from the current time is H1, and the head side of the current time with respect to the head side output value H1 before τ1 hour from the current time. When the reduction rate of the output value H0 is HG1, HG1 is calculated by the following equation (4).

  HG1 = (H1-H0) / H1 Formula (4).

  The second condition is that the rate of decrease of the head-side output value at the current time relative to the head-side output value τ2 hours before the current time is ε2 or more and the current time This is a condition that the state in which the increase rate of the side output value is ε3 or more continues for μ2 hours or more. However, τ2, ε2, μ2, and ε3 are set so as to satisfy the relationships of τ1 ≦ τ2, 0 <ε2 <ε1, μ1 <μ2, and 0 <ε3 ≦ ε2, respectively. The reason will be described later.

  Here, in the second condition, the head side output value at the current time is H0, the head side output value τ2 hours before the current time is H2, and the head side of the current time with respect to the head side output value H2 τ2 hours before the current time The rate of decrease of the output value H0 is HG2, the foot-side output value at the current time is F0, the foot-side output value τ2 hours before the current time is F2, and the foot-time output value F2 is τ2 hours before the current time When the increase rate of the side output value F0 is FZ2, HG2 and FZ2 are calculated by the following equations (5a) and (5b), respectively.

HG2 = (H2-H0) / H2 Formula (5a)
FZ2 = (F0−F2) / F2 Formula (5b).

  As will be described later, τ1 is preferably set to satisfy the relationship of τ1 <τ2, and μ1 is preferably set to satisfy the relationship of μ1 ≦ μ2 × (3/5). . The reason will be described later.

  Note that threshold values such as τ1, τ2, ε1, ε2, ε3, μ1, and μ2 used in the rising motion determination unit 4A are all stored in a predetermined storage unit (not shown) provided in the control unit 2. It is preliminarily set and stored so that the user can arbitrarily change it.

  More specific description of the rising motion determination means 4A is as follows. In the present embodiment, in order to facilitate understanding of the rising motion determination means 4A, the units of τ1, τ2, μ1, and μ2 are all “second (s)”.

  When the user U who has been lying on the bed 30 in a lying posture performs a rising motion, the head-side output value H decreases while the foot-side output value F increases.

  Under the first condition, the decrease rate HG1 of the head-side output value H0 at the current time τ0 seconds with respect to the head-side output value H1 before τ1 seconds from the current time τ0 seconds can be seen from the above equation (4) (H1−H0). ) / H1 value. When HG1 is ε1 or more and the state continues for μ1 seconds or more, the rising motion determination means 4A determines that the first condition is satisfied, that is, the user U on the bed 30 It is determined that the up motion has been performed.

  Under the second condition, the decrease rate HG2 of the head-side output value H0 at the current time τ0 seconds with respect to the head-side output value H2 before τ2 seconds from the current time τ0 seconds can be seen from the above equation (5a) (H2−H0). ) / H2. The increase rate FZ2 of the foot side output value F0 at the current time τ0 seconds relative to the foot side output value F2 before τ2 seconds from the current time τ0 seconds is (F0−F2) / F2 as can be seen from the above equation (5b). Is the value of When HG2 is ε2 or more and FZ2 is ε3 or more and the state continues for μ2 seconds or more, the rising motion determination means 4A determines that the second condition is satisfied, that is, the bed 30 It is determined that the upper user U has started up.

  Therefore, when the rising motion determination means 4A determines that at least one of the first condition and the second condition is satisfied, it is detected that the user U on the bed 30 has lifted. it can.

  Here, in the rising operation determination means 4A, the first condition is a rising determination condition suitable for a fast rising operation, and the second condition is a rising determination condition suitable for a slow rising operation. Therefore, in this embodiment, τ1, τ2, ε1, ε2, ε3, μ1, and μ2 are set as follows. These values are all larger than 0.

  That is, when the rising motion is fast, the head-side output value H decreases in a relatively short time, whereas when the rising motion is slow, the head-side output value H decreases over a relatively long time. Therefore, the relationship between τ1 of the first condition and τ2 of the second condition is set as “τ1 ≦ τ2”.

  Further, when the rising motion is fast, the head side output value H decreases in a relatively short time, so the rate of decrease is relatively large. On the other hand, when the rising motion is slow, the head takes a relatively long time. Since the side output value H decreases, the decrease rate is relatively small. Therefore, the relationship between ε1 of the first condition and ε2 of the second condition is set as “ε1> ε2”.

  By setting in this way, the first condition becomes the rising determination condition suitable when the rising operation is fast, and the second condition becomes the rising determination condition suitable when the rising operation is slow. The rising motion determining means 4A determines whether or not at least one of the first condition and the second condition is satisfied, and it is determined that at least one of the rising motion determining means 4A is satisfied. In this case, a rising alarm is generated by the rising alarm means 5A as information indicating that the user U on the bed 30 has started up. Therefore, whether or not the user U has started up can be determined whether or not the user U has started up slowly, that is, the user U can follow up the speed of the startup operation. Thus, it is possible to reliably detect the rising motion of the user U.

  Further, when the rising operation is slow, the decrease rate of the head-side output value H is relatively small as described above. Therefore, the decreasing rate of the head-side output value H when the rising operation is slow is the rising operation. It is more susceptible to small fluctuations (noise) in the output value that are not related to the start-up operation than the decreasing rate of the head-side output value H in the case of high speed. Therefore, the relationship between μ1 of the first condition and μ2 of the second condition is set as “μ1 <μ2”. Thereby, erroneous determination due to the influence of noise can be avoided, and as a result, the determination accuracy for the rising motion can be improved. Furthermore, by setting “μ1 <μ2”, when the rising operation is fast, the rising operation can be detected earlier than when the rising operation is slow.

  Further, when the rising operation is slow, the decrease rate of the head-side output value H is relatively small as described above, and erroneous determination is likely to occur in the rising determination. On the other hand, the foot side output value F obtained by summing the output values W3 and W4 output from the third and fourth load detection sensors 1c and 1d increases as the user U starts up. Therefore, in the second condition, not only the decrease rate of the head side output value H but also the increase rate of the foot side output value F is added to the rising determination condition. By doing so, it is possible to further improve the determination accuracy for the rising operation (particularly, the slow rising operation). Here, if ε3 is set larger than ε2 (that is, ε3> ε2), the timing of the rising determination is delayed, and the determination following the rising operation becomes difficult. Therefore, ε3 is set as “ε3 ≦ ε2”. By doing so, the timing of the rising determination can be accelerated, and the determination following the rising operation can be reliably performed.

  It is desirable that both τ1 and τ2 are set in the range of 1 second to 10 minutes (600 seconds), and by doing so, it is possible to reliably perform determinations corresponding to various speeds of the rising motion. .

  Although ε1 is not limited, it is preferably set to 5% to 80%, and by doing so, it is possible to reliably make a determination about a fast rising operation.

  Although ε2 is not limited, it is preferably set to 5% to 50%. By doing this, it is possible to reliably determine the slow start-up operation.

  Although ε3 is not limited, it is preferably set to 5% to 50%. By doing this, it is possible to more reliably determine the slow start-up operation.

  Although μ1 is not limited, it is desirable to set it to 1 to 5 seconds, and by doing so, it is possible to reliably make a determination about a fast rising operation.

  Although μ2 is not limited, it is desirable to set it to 1 to 10 seconds, and by doing so, it is possible to reliably determine the slow start-up operation.

  Furthermore, it is desirable that τ1 is set so as to satisfy the relationship of τ1 <τ2. By doing so, the decrease rate HG1 of the head-side output value used in the first condition of the rising motion determination means 4A is set to the second value. It is possible to reliably cope with the latest starting operation rather than the condition. As a result, the first condition is more suitable for the rising determination condition when the rising operation is fast. Therefore, it is possible to reliably determine the rising motion of the user U by following the speed thereof, whereby the rising motion of the user U can be detected more reliably and the rising motion can be prevented. When it is fast, it can be detected more reliably at an earlier stage than when the startup operation is slow.

  Furthermore, it is desirable that μ1 is set so as to satisfy the relationship of μ1 ≦ μ2 × (3/5). By doing so, the first condition of the rising motion determination means 4A is the case where the rising motion is fast. It becomes even more suitable for the rising judgment condition. Therefore, the rising motion of the user U can be determined more reliably following the speed thereof, whereby the rising motion of the user U can be detected more reliably and the rising motion can be detected. When it is fast, it can be detected more reliably at an early stage than when the rising operation is slow.

  Since the value used for the determination of the user U's back raising motion by the rising motion determination means 4A is not the decrease amount of the head-side output value H but the decrease rate, the determination variation due to the weight of the user U is minimized. As a result, the determination accuracy for the back raising operation can be improved.

  The state determination means 6 determines whether or not the operation of the user U on the bed 30 is in a stable state based on the output values W1 to W4 from the first to fourth load detection sensors 1a to 1d. It is determined whether or not the user U has returned on the bed 30 to return from the rising state (preliminary bed leaving operation state) to the bedside state. The state determination means 6 will be described in detail as follows.

  That is, the state determination means 6 outputs the current values from the first to fourth load detection sensors 1a to 1d with respect to the output values W1 to W4 from the first to fourth load detection sensors 1a to 1d at the time of determining the rising motion. When the fluctuation rates of the values W1 to W4 all satisfy a predetermined stability condition, it is determined that the operation of the user U is in a stable state, while the outputs from the first to fourth load detection sensors 1a to 1d. When at least one of the fluctuation rates of the values W1 to W4 does not satisfy the stability condition, it is determined that the operation of the user U is not in a stable state.

  Further, the state determination means 6 increases the head-side output value at the current time with respect to the head-side output value obtained by summing the output values W1 and W2 from the first and second load detection sensors 1a and 1b when the rising motion is determined. Rate, and the rate of decrease in the foot side output value at the current time with respect to the foot side output value obtained by summing the output values W3 and W4 from the third and fourth load detection sensors 1c and 1d at the time of raising motion determination When at least one of them satisfies a predetermined return operation condition, it is determined that the user U has performed a return operation. On the other hand, both the increase rate of the head side output value and the decrease rate of the foot side output value are return operations. When the condition is not satisfied, it is determined that the user U is not performing a return operation.

  Here, “when the rising motion is determined” means when the user U determines that the rising motion is detected by the rising motion determination means 4A.

  The stable condition is a condition that the fluctuation rate of the output value from the load detection sensor is within ± α% and the state continues for t1 time (where t1> 0).

  α is not limited, but is desirably set to 5% to 30%, and by doing so, it is possible to reliably determine the stable states of various users U on the bed 30.

  Although t1 is not limited, it is desirable to set it to 1 second to 120 seconds, and by doing so, the stable states of various users U on the bed 30 can be reliably determined.

  The return operation condition is that at least one of the increase rate of the head side output value at the current time and the decrease rate of the foot side output value at the current time is within λ% (provided that λ ≧ 0) and the state is t2 hours (However, t2> 0).

  λ is not limited, but is desirably set to 5% to 50%, so that return actions of various users U on the bed 30 can be reliably determined.

  Although t2 is not limited, it is desirable to set it to 1 second to 600 seconds, and this makes it possible to reliably determine the return motions of various users U on the bed 30.

Here, under stable conditions, the output values from the first to fourth load detection sensors 1a to 1d at the time of determining the rising motion are W1 _U , W2 _U , W3 _U and W4 _U , respectively, The output values from the four load detection sensors 1a to 1d are W1 ₀ , W2 ₀ , W3 ₀ and W4 ₀ , respectively.

For the output values W1 _U from the first load detection sensor 1a of the electromotive up operation determination time, variation rate V1 of the output value W1 ₀ from the first load detection sensor 1a of the current _{time, (W1 0 -W1 U) /} W1 _U is calculated.

For the output value W2 _U from the second load detection sensor 1b electromotive up operation determination time, the output value W2 ₀ of the variation rate V2 from the second load detection sensor 1b at the current _{time, (W2 0 -W2 U) /} W2 _U is calculated.

For the output value W3 _U from causing up operation determination time of the third load detection sensor 1c, variation rate V3 of the output value W3 ₀ from the third load detection sensor 1c of the current _{time, (W3 0 -W3 U) /} W3 _U is calculated.

For the output value W4 _U from the fourth load detection sensor 1d electromotive up operation determination time, variation rate V4 of the output value W4 ₀ from the fourth load detection sensor 1d of the current _{time, (W4 0 -W4 U) /} W4 _U is calculated.

In the state determination means 6, the output values W1 _{U to} W4 _U from the first to fourth load detection sensors 1a to 1d at the time of the rising motion determination from the first to fourth load detection sensors 1a to 1d at the current time. and if the variation rate V1~V4 output values _W1 0 to w4 ₀ are all satisfied stable condition means a case where none of the V1, V2, V3 and V4 satisfies the stability condition, in this case The operation of the user U is determined to be in a stable state. In addition, when at least one of the fluctuation rates V1 to V4 of the output values W1 _{U to} W4 _U from the first to fourth load detection sensors 1a to 1d at the current time does not satisfy the stability condition, V1, V2, and V3 And at least one of V4 does not satisfy the stability condition. In this case, it is determined that the operation of the user U is not in a stable state.

Here, in the return operation condition, the head side output value at the time of rising motion determination is H _U , the head side output value at the current time is H 0, and the rate of increase of the head side output value H 0 at the current time is HZ _U. . Furthermore, the foot-side output value at the time of judgment caused up operation and F _U, the foot end output value of the current time and F0, the reduction rate of the foot-side output value F0 of the current time and FG _U. HZ _U and FG _U are calculated by the following equations (6a) and (6b), respectively.

HZ _U = (H0−H _U ) / H _U (formula 6a)
_{FG U = (F U -F0)} / F U ... formula (6b).

In the state determination unit 6, and the increase rate HZ _U cranial output value H0 of the current time with respect to the head-side output value H _U when determining force up operation, the current time with respect to the foot-side output value F _U when determining force up operation The case where at least one of the reduction rates FG _U of the foot side output value F0 satisfies the return operation condition means that at least one of the HZ _U and FG _U satisfies the return operation condition. In this case, it is determined that the user U has returned. Further, the case where the reduction rate FG _U rate of increase HZ _U and foot-side output value F0 of the head-side output value H0 does not meet any return operation condition, returning both and the HZ _U and FG _U operating conditions In this case, it is determined that the user U is not performing a return motion.

  When the state determination unit 6 determines that the operation of the user U is not in a stable state and determines that the user U is not performing a return operation, the getting-off operation determination unit 9 first to fourth load detection sensors 1a. Based on the output values W1 to W4 from ˜1d, it is determined whether or not the user U has performed a bed leaving operation. Here, when the user U on the bed 30 leaves the floor, the user U moves from the center of the bed 30 into the outermost area 30A and then leaves the floor. Therefore, in the present embodiment, the bed leaving operation is not only an operation in which the user U on the bed 30 leaves the bed, but also an operation in which the user U moves from the center of the bed 30 into the endmost area 30A of the bed 30. Is included.

  The bed leaving alarm means 15 issues a bed leaving alarm to a caregiver or the like as a notification subject when the user U determines that the bed leaving action judging means 9 has left the bed, and has a speaker or the like. ing.

  The determination method by the leaving action determination means 9 is performed by, for example, a known method, and the basic determination method is, for example, as follows.

  That is, the determination method is a reduction rate or reduction amount of the total output value at the current time with respect to the determination reference value of the total output value obtained by summing the output values W1 to W4 from the first to fourth load detection sensors 1a to 1d. It is determined whether or not the user U has moved out of bed when it is determined whether or not the reduction rate or amount of the total output value at the current time is greater than or equal to a predetermined threshold. On the other hand, when it is determined that the decrease rate or decrease amount of the total output value at the current time is not equal to or greater than a predetermined threshold, it is determined (detected) that the user U is not performing a bed leaving operation.

  As the determination reference value of the total output value, a total output value before a predetermined time from the current time, a total output value when the user U rests on the bed 30, or the like is employed.

  In particular, in the present embodiment, the bed leaving operation determining unit 9 includes the most end area determining unit 10, the elapsed time determining unit 11, the bed end moving alarm unit 15 as one of the bed leaving operation alarm units 15, the bed leaving determining unit 13, and the bed leaving operation alarm. A bed leaving alarm means 14 as one of the means 15 is provided.

  The endmost area determination means 10 is configured so that the gravity center position G of the user U on the bed 30 calculated based on the output values W1 to W4 from the first to fourth load detection sensors 1 a to 1 d is the endmost area of the bed 30. It is determined whether or not it exists within 30A. The gravity center position G of the user U is calculated by, for example, the above formulas (1X) and (1Y).

  The elapsed time determining means 11 determines that the user U is lifted by the rising motion determining means 4A when the extreme end area determining means 10 determines that the gravity center position G of the user U is present in the extreme end area 30A. It is determined whether or not the elapsed time from the time when the operation is determined to the current time is equal to or greater than β hours (where β> 0).

  Although β is not limited, it is desirable to set it to 1 to 5 minutes, and by doing so, it is possible to reliably determine the actions of getting out of various users U on the bed 30.

  When the elapsed time determining unit 11 determines that the elapsed time is equal to or greater than β hours, the endmost alarm unit 12 issues an endmost alarm as one of the bed leaving alarms. The endmost alarm means 12 is configured so that the alarm is automatically stopped when a predetermined time has elapsed from when the alarm is issued, and a caregiver or the like performs an alarm stop operation (eg, alarm) The alarm is forcibly stopped by pressing a stop button (not shown).

  Further, the endmost alarm means 12 is configured to issue the endmost alarm as soon as possible when the elapsed time determination means 11 determines that the elapsed time is β hours or more. Accordingly, the time lag between the elapsed time determination time by the elapsed time determination unit 11 and the occurrence time of the endmost alarm by the endmost alarm unit 12 is very small, and both times are regarded as the same time. good.

  The bed leaving determination means 13 is first to fourth in each of the case where the elapsed time determination means 11 determines that the elapsed time is not more than β hours and the case where the endmost alarm means 12 issues an endmost alarm. It is determined whether or not the user U on the bed 30 has left the bed based on the output values W1 to W4 from the load detection sensors 1a to 1d.

  The determination method by the bed leaving determination unit 13 is performed by, for example, a known method, and the basic determination method is, for example, as follows.

  That is, the determination method is a reduction rate or reduction amount of the total output value at the current time with respect to the determination reference value of the total output value obtained by summing the output values W1 to W4 from the first to fourth load detection sensors 1a to 1d. It is determined whether or not the user U has left the floor when it is determined whether or not the reduction rate or amount of the total output value at the current time is greater than or equal to the predetermined threshold. On the other hand, it is a method of determining (detecting) that the user U is not getting out of bed when it is determined that the reduction rate or reduction amount of the total output value at the current time is not equal to or greater than a predetermined threshold.

  As the determination reference value of the total output value, a total output value before a predetermined time from the current time, a total output value when the user U rests on the bed 30, or the like is employed.

  The bed leaving alarm means 14 issues a bed leaving alarm as one of bed leaving operation alarms when the bed leaving judging means 13 determines that the user U has left the floor. The bed leaving alarm means 14 is configured to automatically stop the alarm when a predetermined time has elapsed from when the alarm is issued, and a caregiver or the like performs a predetermined alarm stop operation (for example: The alarm is forcibly stopped by pressing an alarm stop button (not shown).

  Further, the bed leaving alarm unit 14 is configured to issue a bed leaving alarm as soon as possible when the bed leaving judging unit 13 determines that the user U has left the bed. Therefore, the time lag between the bed leaving determination time by the bed leaving determining means 13 and the time when the bed leaving alarm is generated by the bed leaving alarm means 14 is very small, and both times may be regarded as the same time.

  Furthermore, the detection device 20 of the present embodiment uses the case where the endmost area determination unit 10 determines that the center of gravity G of the user U does not exist within the endmost area 30 </ b> A of the bed 30, and the user who uses the bed leaving determination unit 13. In each of the cases where it is determined that U has not left the floor, it is determined (detected) that the user U is not performing a bed leaving operation, and the state determination means 6 is executed again.

  Next, a bed state detection method for the bed 30 using the detection device 20 of the present embodiment will be described below with reference to FIG.

  In FIG. 4, in step S <b> 1, the user U is lying on the bed 30 in a lying posture. The area of the bed 30 where the user U is bedded (bedbed area) is the center of the bed 30.

  Step S2 corresponds to a rising motion determination step as a bed leaving preliminary motion determination step. In this step S2, it is determined whether or not the user U has started up as a preliminary bed leaving operation on the bed 30 based on the output values W1 to W4 from the first to fourth load detection sensors 1a to 1d. Determination is performed by the determination unit 4A. The determination method is as described in the configuration of the rising motion determination means 4A. If it is determined that the raising operation has been performed (in the case of “YES”), the process proceeds to step S3. If it is determined that the raising operation is not performed (in the case of “NO”), the process returns to step S2.

  Step S3 corresponds to a rising alarm process as the bed leaving preliminary operation alarm process. In step S3, the rising alarm means 5A issues a rising alarm to a caregiver or the like.

  Step S4 corresponds to a state determination step. In this step S4, it is determined whether or not the operation of the user U on the bed 30 is in a stable state based on the output values W1 to W4 from the first to fourth load detection sensors 1a to 1d. The state determination means 6 determines whether or not the user U has performed a return operation of returning from the rising state to the bedside state on 30. The determination method is as described in the configuration of the state determination means 6 described above. If it is determined that the operation of the user U is not in a stable state and it is determined that the user U is not performing a return operation (in the case of “NO”), the process proceeds to step S6. If it is determined that the operation of the user U is in a stable state and / or that the user U has performed a return operation (in the case of “YES”), it is assumed that the user U is in a lying state (step S5), returning to step S2.

  Steps S6 to S10 correspond to a bed leaving operation determination step.

  Step S6 corresponds to the outermost area determination step of the bed leaving operation determination step. In this step S6, the gravity center position G of the user U on the bed 30 calculated based on the output values W1 to W4 from the first to fourth load detection sensors 1a to 1d is within the endmost area 30A of the bed 30. The endmost area determination means 10 determines whether or not it exists. If it is determined that the gravity center position G of the user U exists in the outermost area 30A (in the case of “YES”), the process proceeds to step S7. If it is determined that the gravity center position G of the user U does not exist in the outermost area 30A (in the case of “NO”), the process returns to step S4.

  Step S7 corresponds to the elapsed time determining step of the bed leaving operation determining step. In this step S7, the elapsed time determination means 11 determines whether or not the elapsed time from the time when it is determined that the user U has started up in step S2 to the current time is β hours (where β> 0) or more. To do. In FIG. 4, β time is described as “β minutes”. If it is determined that the elapsed time is equal to or longer than β hours (in the case of “YES”), the process proceeds to step S8, and the extreme end alarm means 12 sets the extreme end alarm to one of the caregivers as one of the bed movement alarms. It emits for (most alarm process). Next, the process proceeds to step S9. If it is determined that the elapsed time is not longer than β time (in the case of “NO”), the process proceeds to step S9 instead of step S8.

  Step S9 corresponds to the bed leaving determination step of the bed leaving operation determination step. In step S9, the bed leaving determination unit 13 determines whether or not the user U on the bed 30 has left the bed based on the output values W1 to W4 from the first to fourth load detection sensors 1a to 1d. The determination method is as described in the configuration of the bed leaving determination unit 13 described above. If it is determined that the user U has left the floor (in the case of “YES”), the process proceeds to step S10, and the bed alarm means 14 issues a bed alarm to the caregiver (bed alarm process). After that, when the user U rests on the bed 30 again (step S11), the process returns to step S2. If it is determined that the user U has not left the floor (in the case of “NO”), the process returns to step S4.

  The detection method of this embodiment has the following advantages.

  According to the detection method of the present embodiment, a user U who has started up as a preliminary bed leaving operation on the bed 30 does not get out of bed while standing up and moves on the bed 30 (eg, the operation of folding laundry). In the case where the operation of repairing the futon, the changing operation, and the operation of organizing the daily necessities, etc.) are performed for a long time, it is determined in step S4 (state determination step) that the operation of the user U is not in a stable state. Then, it is determined that the user U is not performing a return motion, and the process proceeds to Steps S6 to S10 (a bed leaving motion determination step). If it is determined in steps S6 to S10 that the user U is not getting out of bed, the process returns to step S4 (state determination process) instead of step S2 (rise operation determination process), so that the rising alarm is Cannot be raised, the number of rising alarms is reduced. Accordingly, it is possible to suppress unnecessary occurrence of the bed leaving operation alarm such as a rising alarm, and as a result, the burden on the caregiver is reduced. Of course, the detection method according to the present embodiment does not forcibly reset the determination of the rising motion based on the elapsed time from the time when the rising motion is determined. Unnecessary generation can be further suppressed.

  On the other hand, if it is determined in step S4 (state determination step) that the operation of the user U is in a stable state and / or it is determined that the user U has performed a return operation, step S2 (rising operation determination step) Therefore, it can be determined again whether or not the user U has stood up on the bed 30.

  Furthermore, in the case where the user U gets up after moving up on the bed 30 and performing a living action, the user U who has started up and performed the living action leaves the floor. When moving from the center part (bed floor area) of the bed 30 to the endmost area 30A, it is determined in step S6 (endmost area determining step) that the gravity center position G of the user U exists in the endmost area 30A, and step S7. Proceed to (Elapsed time determination step). At this time, since the user U was performing daily activities, the gravity center position G of the user U is the endmost area in step S6 (the endmost area determination step) from the time when it is determined that the user U has started up. The elapsed time up to the time determined to be within 30A is long. As a result, in step S7 (elapsed time determination step), it is determined that the elapsed time is equal to or more than β hours, and the process proceeds to step S8 (endmost alarm step) to generate the endmost alarm. And it progresses to step S9 (bed-out determination process), and when it determines with the user U having left the bed at this step S9, a bed-off alarm is emitted at step S10 (bed-out alarm process).

  On the other hand, when the user U performs the getting-up operation on the bed 30 and then quickly performs the leaving operation without performing the living operation, that is, the user U performs the raising operation and the leaving operation without going through the living operation. In the case of performing the operation, when the user U who has started up moves from the central portion (bedbed area) of the bed 30 to the endmost area 30A, the gravity center position of the user U is determined in step S6 (endmost area determination step). It is determined that G exists in the outermost area 30A, and the process proceeds to step S7 (elapsed time determination step). At this time, since the user U was not performing daily activities, the gravity center position G of the user U is the extreme end in step S6 (the extreme end area determination step) from the time when the user U has determined that the user has moved up. The elapsed time up to the time when it is determined that the area 30A exists is short. As a result, in step S7 (elapsed time determination process), it is determined that the elapsed time is not equal to or more than β hours, and the process proceeds to step S9 (bed-out determination process) instead of step S8 (endmost alarm process). Therefore, the most extreme alarm is not issued. And when it determines with the user U getting out of bed at step S9 (bed-out determination process), a bed-off alarm is emitted at step S10 (bed-out alarm process). Here, when the user U performs the rising motion and the leaving motion in a series of motions as described above, it is determined that the user U has performed the rising motion and the rising alarm is issued from the time when the rising alarm is issued. The elapsed time until the alarm is issued is short, and there is no need to issue an extreme alarm. Therefore, step S8 (endmost alarm process) is omitted when the process proceeds from step S7 (elapsed time determination process) to step S9 (getting out bed determination process). Thereby, unnecessary generation | occurrence | production of the most extreme alarm can be suppressed and the caregiver's burden can further be reduced.

  In the above-described embodiment, the case where the preliminary bed leaving operation is a rising operation has been described. However, in the present invention, the case where the preliminary bed leaving operation is, for example, an operation in which the user U is in the end sitting position, that is, the end sitting position operation is excluded. Not what you want.

  When the bed leaving preliminary operation is the end sitting position operation, the end sitting position operation is a state in which the user U moves from the bedside state while the center of gravity G of the user U exists in the center portion (bed bed area) of the bed 30. The movement of the center of gravity G of the user U from the center of the bed 30 into the end area 30B after the rising state and the center of gravity G of the user U exist in the end area 30B of the bed 30. This means an operation in which the user U rises from the bedside state in a state where the user is standing. Further, in the state determination means 6 (state determination step), the return operation in which the user U returns from the bed leaving preliminary operation state to the bed rest state on the bed 30 is the same as when the bed leaving preliminary operation is a rising operation. It means an operation in which the user U returns from the rising state to the bedside state.

  Further, in the case where the preliminary leaving operation is the end sitting position operation, the end sitting position determining step (end sitting position determining unit) as the leaving preliminary operation determining step (the leaving preliminary operation determining unit 4) is performed by the user U as the preliminary leaving operation. It is determined whether or not the end-sitting operation has been performed. Also, the end sitting position alarm process (end sitting position alarm means) as the leaving bed preliminary operation alarm process (leaving bed preliminary operation alarm means 5) is performed in the end sitting position determination process (end sitting position determination means) by the user U. If it is determined that the alarm has occurred, an end sitting position alarm is issued as a bed leaving preliminary operation alarm. Further, in the state determination step (state determination unit 6), the operation of the user U on the bed 30 is stabilized based on the output value from the load detection unit 1, as in the case where the preliminary bed leaving operation is the rising operation. It is determined whether or not it is in a state and whether or not the user U has performed a return operation on the bed 30 to return from the rising state to the bedside state.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

  In the above-described embodiment, the second condition of the rising motion determination means 4A is that the rate of decrease HG2 of the head-side output value at the current time with respect to the head-side output value two hours before the current time is ε2 or more and τ2 from the current time. The condition that the rate of increase FZ2 of the foot side output value at the current time with respect to the foot side output value before time is ε3 or more continues for μ2 hours or more, but in the present invention, the second condition is limited to this. Alternatively, the condition may be that the state in which the decrease rate HG2 of the current-side head-side output value with respect to the head-side output value τ2 hours before the current time is ε2 or more continues for μ2 hours or more.

  Moreover, in the said embodiment, although the load value is used as the output values W1-W4 from the 1st-4th load detection sensors 1a-1d, in this invention, the output value from a load detection sensor is a load value. For example, a voltage value corresponding to a load applied to a corresponding portion of the bed 30 may be used. In this case, the load value can be calculated by converting the voltage value according to a predetermined conversion formula, and the load value calculation means (including the signal amplification unit and the A / D conversion unit) for performing the calculation is, for example, a control Mean 2 is provided.

  Moreover, in the said embodiment, although the load detection sensors 1a-1d are arrange | positioned between the leg parts 31a-31d of the bed 30, and the floor surface 35, in this invention, a load detection sensor is arrange | positioned at this location. It is not limited to. For example, the load detection sensor is disposed in the middle of a load transmission path through which a load applied to the bed 30 is transmitted from the bed 30 to the floor surface 35. Specifically, the load detection sensor is disposed between the bed 30 and each leg 31a to 31d (eg, a connecting frame) or between the bed 30 and each leg 31a to 31d. A support part (e.g., support frame) that supports 30, a link part (e.g., link frame, link shaft) of an elevating mechanism that raises and lowers the bed 30, each leg part 31 a to 31 d, and each leg part 31 a to 31 d It is arranged by being attached to or incorporated in a connecting part for connecting the bed moving caster, a caster shaft part or the like.

  INDUSTRIAL APPLICABILITY The present invention is applicable to a bed occupancy status detection method and a bed occupancy status detection device that detect the user's occupancy status on a bed.

1: load detection means 4: getting-off preliminary operation determining means 4A: rising action determining means 5: getting-off preliminary action alarm means 5A: rising alarm means 6: state determining means 9: getting-off action determining means 10: extreme end area determining means 11: Elapsed time determination means 12: Endmost alarm means 13: Getaway determination means 14: Getaway alarm means 15: Getaway operation alarm means 20: Bed occupancy status detection device 30: Bed 30A: Endmost area U: Bed User

Claims (8)

A load detection step of detecting a load applied to the bed on which the bed user is bedded at a predetermined detection cycle by the load detection means;
A bed leaving preliminary operation determining step for determining whether or not the user has performed a bed leaving preliminary operation on the bed based on an output value from the load detecting means,
When it is determined that the user has performed a preliminary bed leaving operation in the preliminary bed leaving operation determining step, a bed leaving preliminary operation alarm step for issuing a bed leaving preliminary operation alarm; and
After issuing the bed leaving preliminary operation alarm, it is determined whether or not the user's operation on the bed is in a stable state based on the output value from the load detection means, and the user leaves the bed on the bed. A state determination step of determining whether or not a return operation of returning from the preliminary operation state to the bedrock state has been performed;
When it is determined in the state determination step that the user's operation is not in a stable state and the user determines that the return operation is not performed, the user performs a bed leaving operation based on an output value from the load detection means. A step of determining whether to get out of bed,
When it is determined that the user has made a bed-moving operation in the bed-moving operation determination step, a bed-moving operation alarm step for issuing a bed-moving operation alarm is included.
The bed occupancy status detection method, wherein when the user determines that the user is not performing a bed leaving operation in the bed leaving operation determining step, the process returns to the state determining step. The step of determining the bed leaving operation
An endmost area determination step of determining whether or not the position of the center of gravity of the user on the bed calculated based on the output value from the load detection means exists in the endmost area of the bed;
When it is determined in the extreme end area determination step that the user's center of gravity exists within the extreme end area, the current time is determined from the time when the preliminary release operation determination step is determined by the user to perform the preliminary release operation. An elapsed time determination step for determining whether or not the elapsed time up to β hours (where β> 0) or more,
When it is determined that the elapsed time is equal to or longer than the β time in the elapsed time determination step, an endmost alarm step of issuing an endmost alarm as one of the bed leaving operation alarms;
The output value from the load detecting means in each of the case where the elapsed time is determined not to be equal to or longer than the β time in the elapsed time determination step and the case where the endmost alarm is issued in the endmost alarm step. A step of determining whether or not the user on the bed has left the bed based on
When it is determined that the user has left the floor in the bed leaving determination step, a bed leaving alarm step for issuing a bed leaving alarm as one of the bed moving operation alarms is provided.
In each of the case where it is determined that the center of gravity position of the user does not exist in the endmost area in the endmost area determination step and the case where it is determined that the user has not left the floor in the step-out determination step. The bed presence condition detection method according to claim 1, wherein it is determined that the user is not performing a bed leaving operation and the process returns to the state determination step. The load detection means includes first to fourth load detection sensors that respectively detect loads applied to a head-side right part, a head-side left part, a foot-side right part, and a foot-side left part of a bed on which a user is bedded. And
In the state determination step, the first to fourth of the current time with respect to the output values from the first to fourth load detection sensors when it is determined that the user has performed a preliminary bed leaving operation in the preliminary bed leaving operation determining step. When the fluctuation rate of the output value from the load detection sensor is within ± α% and the stable condition that the state continues for t1 time (where t1> 0) is satisfied, the user's When it is determined that the operation is in a stable state, and at least one of the fluctuation rates of the output values from the first to fourth load detection sensors does not satisfy the stability condition, the user's operation is in a stable state. The bed occupancy status detection method according to claim 1 or 2, wherein it is determined that it is not.   The state determination step includes a current time with respect to a head-side output value obtained by summing up the output values from the first and second load detection sensors when it is determined that the user has performed a bed leaving preliminary operation in the bed leaving preliminary operation determination step. Foot side output value obtained by summing up the increase rate of the head side output value and the output values from the third and fourth load detection sensors when it is determined that the user has made a bed leaving preliminary operation in the bed leaving preliminary movement determination step Of at least one of the decrease rate of the foot side output value at the present time is within λ% (provided that λ ≧ 0) and the state continues for t2 hours (provided that t2> 0) or more. When the operation condition is satisfied, it is determined that the user has performed the return operation. On the other hand, the increase rate of the head side output value and the decrease rate of the foot side output value both satisfy the return operation condition. If the user does not The bed occupancy state detection method according to claim 3, wherein it is determined that the bed is present. A load detecting means for detecting a load applied to the bed on which the bed user has been bedded at a predetermined detection cycle;
A bed leaving preliminary operation determining unit that determines whether or not the user has performed a bed leaving preliminary operation on the bed based on an output value from the load detecting unit;
When it is determined that the user has performed a preliminary bed leaving operation by the preliminary bed leaving operation determining means, a bed leaving preliminary operation alarm means for issuing a bed leaving preliminary operation alarm; and
After issuing the bed leaving preliminary operation alarm, it is determined whether or not the user's operation on the bed is in a stable state based on the output value from the load detection means, and the user leaves the bed on the bed. State determination means for determining whether or not a return operation of returning from the preliminary operation state to the bedside state has been performed;
When it is determined by the state determination means that the user's operation is not in a stable state and the user determines that the return operation is not performed, the user performs a bed leaving operation based on an output value from the load detection means. Leaving motion determining means for determining whether or not
A bed movement alarm means for issuing a bed movement alarm when it is determined by the bed movement determination means that the user has made a bed movement;
The bed occupancy status detection apparatus is configured to execute the state determination unit again when it is determined by the bed movement determination unit that the user is not performing a bed leaving operation. The getting-off motion determining means includes
An endmost area determination means for determining whether or not the position of the center of gravity of the user on the bed calculated based on the output value from the load detection means exists in the endmost area of the bed;
When it is determined by the endmost area determination means that the position of the center of gravity of the user is present in the endmost area, the current time is determined from the time at which the user has made a preliminary bed leaving operation by the preliminary bed leaving action determination means. Elapsed time determination means for determining whether or not the elapsed time up to β hours (where β> 0) or more,
When the elapsed time determining means determines that the elapsed time is equal to or greater than the β time, an endmost alarm means for issuing an endmost alarm as one of the bed leaving movement alarms;
The output value from the load detection means in each of the case where the elapsed time determination means determines that the elapsed time is not greater than the β time and the case where the extreme end alarm means issues the extreme end alarm. A bed determining means for determining whether or not the user on the bed has left the bed based on
A bed alarm means for issuing a bed alarm as one of the bed movement alarms when it is determined that the user has left the bed using the bed determination means;
In each of the case where it is determined that the position of the center of gravity of the user does not exist in the endmost area by the endmost area determination unit and the case where the user determines that the user has not left the floor by the bed leaving determination unit. The bed occupancy state detection device according to claim 5, wherein the bed state detection device is configured to determine that the user is not performing a bed leaving operation and to execute the state determination unit again. The load detection means includes first to fourth load detection sensors that respectively detect loads applied to a head-side right part, a head-side left part, a foot-side right part, and a foot-side left part of a bed on which a user is bedded. And
The state determination means is the first to fourth of the current time with respect to the output values from the first to fourth load detection sensors when it is determined by the preliminary movement preliminary movement determination means that the user has performed preliminary bed movement. When the fluctuation rate of the output value from the load detection sensor is within ± α% and the stable condition that the state continues for t1 time (where t1> 0) is satisfied, the user's When it is determined that the operation is in a stable state, and at least one of the fluctuation rates of the output values from the first to fourth load detection sensors does not satisfy the stability condition, the user's operation is in a stable state. The bed occupancy state detection device according to claim 5 or 6 that is determined to be not.   The state determination means is a current time with respect to a head side output value obtained by summing up the output values from the first and second load detection sensors when it is determined by the preliminary bed removal action determination means that the user has made a preliminary bed removal action. Foot side output value obtained by summing the rate of increase of the head side output value and the output values from the third and fourth load detection sensors when it is determined by the preliminary bed leaving movement determination means that the user has performed the bed leaving preliminary movement. Of at least one of the decrease rate of the foot side output value at the present time is within λ% (provided that λ ≧ 0) and the state continues for t2 hours (provided that t2> 0) or more. When the operation condition is satisfied, it is determined that the user has performed the return operation. On the other hand, the increase rate of the head side output value and the decrease rate of the foot side output value both satisfy the return operation condition. If the user does not The bed occupancy state detection device according to claim 7, wherein the bed presence state detection device is determined to be.

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