JP6530544B1 - Bed departure detection system - Google Patents

Abstract

An object of the present invention is to provide a bed departure detection system which detects and reports bed leaving of a subject of care or nursing. A sensor A installed above the upper surface of a bed and detecting the upper body of a subject, and a sensor B installed above the floor and below the upper surface of the bed and detecting a leg of the subject The bed departure detection system according to the present invention determines the movement of the subject based on the outputs of the sensor A and the sensor B, and the sensor A moves its central axis inward from the bedside to make the upper surface of the bed a detection range. The sensor B is installed so that the central axis of the sensor B is shifted outward from the bedside to set the side of the bed as a detection range, and the central axis of the sensor A and the central axis of the sensor B are It was made to be in the position of twisting to each other. [Selected figure] Figure 1

Description

The present invention relates to a system for detecting and giving notice of bed departure from a bed of a care or nursing subject.

With the declining birth rate and aging population, the number of people with heavy care and the number of elderly people who need to watch are increasing, and the burden of nursing care continues to increase. Accidents at nursing homes for elderly people are also increasing, and the type of fall is the majority, and the problem of watching over at care sites is an important issue.
However, there is a current situation where it is difficult for the carer to watch over, and the reasons are lack of care workers, fatigue of staff, increased stress, thinking about falling (the elderly can not fall), quality of care (Knowledge and technology), inadequate maintenance of the environment, etc. are mentioned.
The reason for the user side is that they can not or do not call, decline in cognitive function and physical function, care for care staff, withholding, desire not to be interfered, and desire to act freely.
Under such circumstances, there are various systems on the market that automatically notify the danger of falling or falling without putting a burden on caregivers as much as possible, but unfortunately enough things have not appeared yet .
The biggest reason is that the alarm is issued regardless of the individual circumstances of the person being cared, or the alarm is sounded when the tread is stepped on the bed, or the alarm is sounded if the grip of the bed fence is grasped. Many have been linked to the feeling of tiredness of the carers who rush to that time.
Also, as a system for informing the danger of falling or falling, detection at the time of leaving the bed is general, but depending on the level of the target person, it may be desirable to make the range of action a bit wider.
In this case, it is expected that the danger is assumed to be possible because it is assumed to go to the bathroom by itself or to go out from the living room area.
In view of such circumstances, conventionally, a technology using an infrared temperature sensor is widely used as a system for detecting and giving notice of bed leaving from the bed of a subject who receives care or nursing.
However, in the technology using an infrared temperature sensor, it is possible to install the sensor on an unobtrusive place such as on the bed or at the end of the bed, but the infrared temperature sensor has a sensing range, depending on the distance. There is a characteristic that the sensing range is expanded.
For this reason, the detection area by the infrared temperature sensor becomes vague, and there is a problem that a malfunction caused by detecting a nurse or a family, or a malfunction caused by sunlight or a cold of an air conditioner occurs.
As a technique for solving such problems, for example, in the bed departure detecting device described in Patent Document 1, a foot dropped from a bed in a specific area using a distance sensor placed out of the way. Is detected.
Moreover, in the state determination apparatus described in patent document 2, the vibration sensor information and load sensor information on a bed are combined, and the preparation behavior before leaving is determined.

JP, 2009-207685, A JP, 2009-151473, A

However, in the above-described conventional techniques, there is an occurrence of malfunction or false detection that detects a nurse or a family member.
Therefore, the present invention has been made in consideration of the above situation, and it is an object of the present invention to provide a bed leaving detection system capable of accurately detecting a subject's bed leaving when performing nursing or nursing care. .
Another object of the present invention is to provide a bed leaving detection system which separates and clarifies the detection area by a plurality of sensors, and prevents the occurrence of malfunction or false detection which detects a nurse or a family member.

(1) The bed departure detection system of the present invention is
A sensor A installed on top of a pole standing on a base separate from the bed and installed above the top of the bed to detect the upper body of the subject,
A sensor B installed under the pole erected on the base and installed above the floor surface and below the upper surface of the bed to detect the leg of the subject;
The sensor A and the sensor B are pyroelectric infrared receiving sensors,
It is a bed departure detection system which discriminate | determines a subject's operation | movement based on the output of only said sensor A and sensor B, Comprising:
The sensor A is
Move the center axis A1 inward from the bedside,
The top of the bed is set as the detection range,
The sensor B is
Move the center axis B1 outward from the bedside,
It is installed so that the side of bed is a detection range,
The central axis A1 of the sensor A and the central axis B1 of the sensor B
It is characterized in that they are in the position of twisting to each other.
(2) The bed leaving detection system according to the present invention is characterized in that, in the above (1), the installation height of the sensor A and the sensor B can be adjusted.
(3) In the bed departure detection system of the present invention, in the above (1) or (2),
The sensor A and the sensor B are
If the number of times e detected the subject simultaneously exceeds a predetermined value,
When the number of times a detected by the sensor A becomes larger than the number b detected by the sensor B,
It is characterized in that the notification unit transmits a signal indicating that the target person has started to leave the bed.

The bed leaving detection system according to the present invention can accurately detect the bed leaving of the subject in performing nursing or nursing care, and the detection area can be divided and clarified by a plurality of sensors. It is possible to prevent the occurrence of a malfunction or a false detection that detects a family.

It is the schematic of the bed leaving detection apparatus used for the bed leaving detection system of embodiment of this invention, (a) is a front view, (b) is a right view, (c) is a top view. It is a block diagram of a bed leaving detection system of an embodiment. It is installation explanatory drawing of the bed leaving detection apparatus in the bed leaving detection system of embodiment. It is an explanatory view showing a detection area of sensor A and sensor B in a bed leaving detection system of an embodiment, (a) is a top view, (b) is a front view. It is explanatory drawing of the adjustment means of the detection area of the sensor used for a bed leaving detection apparatus. It is a flowchart of the bed leaving detection system of an embodiment. 6 is a graph for explaining the details of the arithmetic processing in the flowchart of FIG. 6, (1) is a counter a, (2) is a counter b, (3) is a counter c, (4) is a counter d, and (5) is a counter e The change of the total counter number of each of,. It is the graph which accumulated and illustrated the counters a, b, c, d, and e of FIG. 7 (1)-(5). It is explanatory drawing of the example 1 of a change which applied the case of the bed departure detection system of embodiment to the case where the operation | movement which goes to a bathroom alone is detected. It is explanatory drawing which shows the detection area of the sensor A in the modification 1, and the sensor B, (a) is a top view, (b) is a front view. It is a graph explaining the details of operation processing in modification example 1, (1) is counter a, (2) is counter b, (3) is counter c, (4) is counter d, (5) is counter e, Shows the change in the cumulative count of each of. It is the graph which piled up counters a, b, c, d, and e of FIG. 11 (1)-(5). It is explanatory drawing of the example 2 of a change which applied the case of the bed leaving detection system of embodiment to the case where the operation | movement which walks out of a living room alone is detected. It is explanatory drawing which shows the detection area of the sensor A in the modification 2, and the sensor B, (a) is a top view, (b) is a front view. It is a graph explaining the details of operation processing in modification example 2, (1) is counter a, (2) is counter b, (3) is counter c, (4) is counter d, (5) is counter e, Shows the change in the cumulative count of each of. It is the graph which piled up counters a, b, c, d, and e of FIG. 15 (1)-(5).

Hereinafter, the bed departure detection system of the present invention will be described with reference to the drawings.
FIG. 1 shows a bed leaving detecting apparatus 10 used in the bed leaving detecting system of the present invention.
As shown in FIG. 1, the bed leaving detection device 10 is provided with a sensor A and a sensor B on the upper part and the lower part of the pole 12 erected on the base 11.
It is desirable that the sensor A installed on the top of the pole 12 be able to extend and retract and rotate the pole 12 so that the installation height and the central axis A1 can be set arbitrarily.
In addition, since the position at which the legs are lowered when leaving the bed may differ depending on the height of the subject, the mechanism for adjusting the installation position of the sensor B and the central axis B1 may be provided according to the position.

<Sensor>
As the sensor A and the sensor B, there may be mentioned a pyroelectric infrared sensor for capturing the motion of a person. Among them, it is desirable to use a fine movement detection type (for example, AMN 32112 manufactured by Panasonic Corporation).
A pyroelectric infrared sensor is a sensor that detects a change in infrared that occurs when a person with a temperature difference from the environment moves.
In order to detect a temperature difference, it is an optimal sensor for detecting the movement of a human body having a body temperature.
Also, instead of the pyroelectric infrared sensor, an ultrasonic transmission / reception sensor can be used.
The ultrasonic wave emitted from the ultrasonic sensor is reflected on the subject and reflected back to the ultrasonic sensor to be received, and the distance to the subject at this time can be determined.
Compared to the pyroelectric infrared sensor, there is an advantage that it is not affected by direct sunlight or air conditioning.
In the embodiment of the present invention, the detection distance between the sensor A and the sensor B is not particularly determined, but a distance of about 2 m is preferably used.
The detection range is preferably such that the central axis of the sensor is symmetrical, and the detection range extends approximately 51 ° in the vertical direction and the horizontal direction.

In order to detect the upper body X1 of the subject X seated on the bed BE, for example, the sensor A is preferably installed at a height h1 (for example, about 20 cm or more) above the bed upper surface BE1.
Further, the central axis A1 of the sensor A is installed inward from the bedside BE2 at an angle in the horizontal direction so as to set the bed upper surface BE1 as a detection range (see FIGS. 3 and 4).
In FIG. 4, the bedside BE 2 is installed at the corner on the head side of the bed BE on the open side of the fence.

The sensor B is preferably installed at a height h2 below the bed upper surface BE1 (for example, 5 cm or more from the floor F) to detect the leg X3 of the subject X seated on the bed BE.
In addition, the central axis B1 of the sensor B is installed at an angle in the horizontal direction so as to be shifted outward from the bedside BE2 so that the bedside BE2 is set as a detection range.
Thus, the sensor B can reliably detect when the object person X comes out of the leg X3 from the bedside BE2.
When the central axes A1 and B1 detected by the sensor A and the sensor B are attached to the pole 12, respectively, the horizontal direction and the vertical direction can be determined independently.

<Position of twist>
Further, the central axes A1 and B1 of the sensor A and the sensor B are set to be in a mutually twisted position.
The position of twist means a positional relationship in which two central axes A1 and B1 are not parallel, do not intersect, and do not exist on the same plane in the space.
When the subject sits down on the bedside BE2 and lowers the leg X3 in order to leave the bed, the sensor A and the sensor B always detect it simultaneously (see FIG. 4).
At this time, by installing the sensor A and the sensor B separately on the upper and lower sides of the pole 12 and with the respective central axes A1 and B1 being in the position of twist, the same part of the subject person can be There is no case of duplicate detection with B, and detection accuracy can be improved.

Thus, the sensor A and the sensor B can accurately detect the motion of the subject who is about to leave the bed.
In the present specification, the bed upper surface BE1 refers to the upper surface when a mattress or the like is laid, and the bedside BE2 is the side on which the target person gets off the bed and the side where a part of the bed fence is opened. .

<Adjustment of detection area>
FIG. 5 is an explanatory view of detection area adjustment means attached around the sensors A and B. As shown in FIG.
As shown in FIG. 5, the sensor A is directly attached to the outer surface of the pole 12 or the base 11, but its detection area is determined in advance by the type of sensor.
If the detection area is made large (the angle with the central axis is large), it is easy to pick up the noise, and if it is made small, the movement of the subject may not be accurately detected.
In such a case, by providing a cylindrical cylinder around the sensor, the angle range detected by the sensor can be determined in advance, and the size of the detection area can be adjusted.
As shown in FIG. 5, when the front of the sensor is covered with a thin cylinder, the detection area is narrowed to enable accurate detection of the motion of the object person.

<Block diagram>
The block diagram of the bed leaving detection system of this embodiment is shown in FIG.
As shown in FIG. 2, the bed departure detection system according to the present embodiment includes a sensor A and a sensor B that detect a subject's bed departure behavior, and a communication unit 21 that transmits signals from the sensor A and the sensor B to the arithmetic processing unit 22. A storage unit 23 for recording the result processed by the arithmetic processing unit 22 based on the information from the communication unit 21; and a notification unit 24 for receiving the result when the arithmetic processing unit 22 is determined to be dislocated. Have.
Moreover, although the notification apparatuses, such as a display apparatus linked with the alerting | reporting part 24, and a nurse call, can also be provided, it does not show in figure.
The arithmetic processing unit 22 is a known device having a sensor interface, a microcomputer, and the like, and determines an action of a subject who wants to leave the bed BE based on an output signal from the communication unit 21.
The arithmetic processing unit 22 and the storage unit 23 may be in the vicinity of the sensor A and the sensor B or in a distant server via a network.

<Flow chart>
Next, the flow of the bed departure detection system according to the embodiment of the present invention will be described.
FIG. 6 is a flowchart showing the bed leaving detection process of the bed leaving detection system in the present embodiment.
This flow chart is used to show the flow of determining the bed release based on the information from the sensor A and the sensor B and notifying the notification unit.

<S1>
The following parameter information (m, n, t) is input in advance as preparation.
A threshold m for resetting the number of times when the number of times sensor A and sensor B do not detect each exceeds a predetermined value, and when the number of times simultaneously detected by sensors A and B exceeds a predetermined value A threshold n and t which defines an interval at which the sensor detects a subject are set (S1).
The parameters m, n and t are arbitrary optimum values for each subject (details will be described later).
The processing loop is as follows.

<S2>
The sensor A for capturing the motion on the bed and the sensor B for capturing the motion on the bedside simultaneously perform detection at an interval of t seconds (S2).
In the bed departure detection system of the present embodiment, it is determined whether both the sensor A and the sensor B have detected within t seconds.

<Parameter t>
By controlling the detection time of the bed departure detection system as a parameter without setting t as a fixed value, the two sensors of sensor A and sensor B can adjust the length of time judged as simultaneous detection, and the target person can simultaneously Although it becomes detection, it is possible to make identification using the agility of movement as an indicator that it is difficult for a caregiver to simultaneously detect (details will be described later).

<S3>
It is determined whether sensor A and sensor B detect at the same time.
If it is determined that both the sensor A and the sensor B have detected, it is determined that only the target person has been detected, and processing in the Y direction is performed.
When only the sensor A is detected, processing in the N direction is performed without determining that only the target person is detected.

<S4>
In (S3-N), when the sensor A and the sensor B do not detect at the same time, it is determined whether only the sensor A has detected.

<S5>
When only the sensor A is detected in (S4-Y), 1 is added to the counter a detected by the sensor A, the counter c is reset to 0, and the process proceeds to S10.

<Counter a to e>
In the following description, counters a to e appear, but these have the following contents.
The counter a is data obtained by counting the number of times the sensor A has detected.
The counter b is data obtained by counting the number of times detected by the sensor B.
The counter c is data obtained by counting the number of times the sensor A did not detect.
The counter d is data obtained by counting the number of times the sensor B did not detect.
The counter e is data obtained by counting the number of times the sensor A and the sensor B simultaneously detect.

<S6>
In (S4-N), when it is not the case that only the sensor A is detected, 1 is added to the counter c.
<S7>
It is determined whether only the sensor B has detected.
<S8>
In (S7-N), when it does not correspond to only the sensor B detecting, 1 is added to the counter d, and it progresses to S10.
<S9>
When only the sensor B is detected in (S7-Y), 1 is added to the counter b, the counter d is reset to 0, and the process proceeds to S10.
<S10>
It is determined whether the counter c and the counter d exceed the parameter m.

<S11>
If the counter c and the counter d exceed the predetermined value m in (S10-Y), the following processing is performed.
The counters a, b, c, d and e are all reset to 0 and return to the beginning of the processing loop.
That is, when the number of times the sensor A or the sensor B does not detect reaches the parameter m, the counter is reset to 0.
The reason is that a series of activities between time without activity is regarded as a single cluster (hereinafter referred to as a cluster), and each cluster activity is a bed activity, a bedside activity, or a preparation activity for leaving the bed This is to determine the boundary of the cluster.
For example, after detecting the motion of the target person on the bed, the detection of carers, nurses, family members, etc. other than the target person is continued to start at the bedside despite the fact that time has passed for a while In addition, if two different activities are evaluated as one activity, the counter is reset to 0 if there is no detection for a certain period of time, in order to prevent accurate detection from becoming impossible.

<S12>
If the counter c and the counter d do not exceed the predetermined value m in (S10-N), it is determined whether the counter c does not exceed the predetermined value m (S12).
<S13>
If the counter c exceeds the predetermined value m in (S12-Y), the counters a, c and e are all reset to 0 and the process returns to the beginning of the processing loop.

<S14>
In (S12-N), if the counter c does not exceed the predetermined value m, it is determined whether the counter d does not exceed the predetermined value m. If not, the process returns to the beginning of the processing loop.

<S15>
If the counter d exceeds the predetermined value m in (S14-Y), the counters b, d and e are all reset to 0 and the process returns to the beginning of the processing loop.

<S16>
In (S3-Y), when the sensor A and the sensor B detect simultaneously, 1 is added to each of the counter a, the counter b and the counter e.
<S17>
It is determined whether the counter e has exceeded a predetermined threshold n, and if it has not, the process returns to the beginning of the processing loop.
<S18>
In the case of (S17-Y), it is determined whether the counter a is larger than the counter b.
<S19>
In the case of (S18-N), since the counter b is larger than the counter a, it is not notified as an activity other than the bedside target person, the counters a and e are reset to 0, and the counter c or d is reset. A series of activities above the predetermined value m until the value is reset are fixed as bedside activities and return to the beginning of the processing loop.
<S20>
In the case of (S18-Y), it is determined that the bed has left and the notification unit is notified (S21).

<About the concept of this departure detection system>
When the counter e indicating the number of times the sensor A and the sensor B detect simultaneously exceeds the parameter n, the counter a indicating the number of times the sensor A detects becomes larger than the counter b indicating the number of times the sensor B detects , Judging that bedriding activity was started.
However, if the counter e does not exceed the parameter n, it is not used as an indicator for leaving the bed, because the above-mentioned guard target person and the carer are identified, and the target person on the bed and activities other than the bedside target person , To eliminate the chance of accidental occurrence of the same timing.
This is to reduce the false alarm by optimizing the numerical value for each target person, since the activities having the same timing differ depending on the degree of assistance to the target person and the content of the activity of the target person.
In addition, depending on the speed of the subject's activity, it may take a considerable amount of time to actually leave the bed after the sensor A and the sensor B simultaneously detect it at the same time, and it is also for avoiding premature bed break notification .

Furthermore, when the counter e reaches the parameter n and the activity of the cluster is centered on the bed activity, the counter a> the counter b is obtained, so it is judged as the bed leaving preparation activity.

In addition, when bedside activities are the main thing, counter b> counter a, and it will be activities of caregivers and family members other than the target person, or return activities of the target person, so it will not be judged as leaving preparation activity. .
In that case, the counters a and e are reset to 0, and the cluster is not to be ready to leave.
This is because the carer's movement on the bed thereafter increases and the determination is not wrong when counter a> counter b is reversed.

The parameters m, n, t are set by machine learning because the optimum values differ depending on the action pattern of the subject or the caregiver.

FIG. 7 is a graph illustrating the details of the calculation process in the flowchart of FIG.
FIG. 7 (1) shows the change of the cumulative count number of the counter a with the passage of time.
FIG. 7 (2) shows the change of the accumulated count number of the counter b with the passage of time.
FIG. 7 (3) shows the change of the accumulated count number of the counter c with the passage of time.
When the cumulative number exceeds m, the counters a, c, and e are reset to zero.
FIG. 7 (4) shows the change of the accumulated count number of the counter d with the passage of time.
If the cumulative number exceeds m, b, d and e are reset to 0.
FIG. 7 (5) shows the change of the accumulated count number of the counter e with the passage of time.
In Example 1, the detection time interval in the case of detecting bed leaving was set to about 2 seconds, m = 5, n = 5.
When the accumulated count number exceeds n, and when the counter a> the counter b, the notification unit notifies that the target person has entered the monitoring area.
If the total number exceeds n and Counter b> Counter a, reset Counter a and Counter e to 0 and set Counter b> Counter a for bedside activities of caregivers etc. other than the target person. Are fixed and this series of operations (clusters) is not notified.
Here, the monitoring area refers to a range in which the sensor A and the sensor B simultaneously detect the target person.

FIG. 8 is a graph in which the counters a, b, c, d, and e in FIGS. 7 (1) to (5) are superimposed and illustrated.
As shown in FIG. 8, a counter a which is an operation on the bed is accumulated from 6:08:57 (meaning 6:08:57, which is the same in the following description).
In this operation, although the value of the counter c does not exceed 5, it is intermittently stacked, but the value of the counter c exceeds 5 before 6:13:11, so a = 0, c It is reset to 0, which is a break of one activity block (cluster).
It can be seen that the cumulative counting of the counter b indicating the bedside operation starts at 6:16:15, and before 6:17:07, the cumulative counting of the counter a indicating the operation on the bed also starts.
Since these operations are simultaneously detected, it can be seen that the cumulative count of the counter e is also increasing.
When the counter e becomes 6 and the counter e becomes n, the operation of the bedside is larger in the counter b> counter a in the comparison between the counter a and the counter b. It has not been determined that the subject entered the surveillance area as a combined result of the actions of the subject and the subject on the bed.
The cumulative count of the counter b starts from 6:19:46, and the cumulative count of a and e starts later, which ends as a small cluster that does not satisfy the counter e> n.
The cumulative count of counter a starts from 6:22:04 onwards, e becomes 6 at 6:22:43 and exceeds n, and it is judged that it has entered the monitoring area for counter a> counter b, and the notification unit Sent to

The bed departure detection system of the present invention is applicable to cases where one tries to go to the bathroom by himself or to go outside from the living room area, and therefore, will be described as a modified example.
That is, also in the case of trying to go to the bathroom other than leaving the bed by itself or detecting when going out from the living room area, providing an area (monitoring area) to be detected simultaneously and the starting point of the operation are the sensor A and It is important to set up to

<Modification 1>
FIG. 9 is an explanatory view of a modified example 1 in which the bed departure detection system of the embodiment is applied to the case of detecting an operation of going to the bathroom alone.
FIG. 10 is an explanatory view showing detection areas of the sensor A and the sensor B in the first modification, (a) is a plan view, and (b) is a front view.
As illustrated, the bed leaving detection device 10 was installed beside the bathroom entrance so that the central axis B1 of the sensor B would cross the bathroom entrance.
The central axis A1 of the sensor A is directed to the indoor side by about 30 ° to 50 ° with respect to the central axis B1 of the sensor B.
As a result, the detection areas of the sensor A and the sensor B overlap at the entrance of the bathroom, and the detection area of the sensor A is further expanded to the indoor side.
When passing by the entrance of the bathroom to go to the bathroom, the subject always passes simultaneously through the sensor A and the sensor B detection areas next to the sensor A detection area.
In this case, adjustment in the height direction of the sensor A and the sensor B is not necessary.
In Modification Example 1, the detection time interval is set to approximately 2 seconds, m = 5, and n = 3.
In the first modification, the sensor A is installed near the bathroom entrance.
Sensor B was installed toward the subject's leg X3 inside the bathroom.
FIG. 11 (1) shows the change of the cumulative count number of the counter a with the passage of time.
a indicates the number of times the sensor A has detected.
FIG. 11 (2) shows the change of the accumulated count number of the counter b with the passage of time.
b shows the number of times detected by the sensor B.
FIG. 11 (3) shows the change of the accumulated count number of the counter c with the passage of time.
c shows the number of times when the sensor A does not detect continuously.
If the cumulative number exceeds m, a, c and e are reset to 0.
FIG. 11 (4) shows the change of the accumulated count number of the counter d with the passage of time.
d shows the number of times when the sensor B does not detect continuously.
If the cumulative number exceeds m, b, d and e are reset to 0.
FIG. 11 (5) shows the change of the accumulated count number of the counter e with the passage of time.
e indicates the number of times the sensor A and the sensor B simultaneously detect.
When the total number exceeds n and a> b, the notification unit notifies that the target person has entered the monitoring area.
The detection of the sensor B in a state in which the door is opened and it is about to enter is a point of notification, so the state in which the door is closed by entering the inside is not a target of detection.
FIG. 12 is a graph in which the counters a, b, c, d, and e in FIGS. 11 (1) to (5) are superimposed.
As illustrated,
From 14:28:37, a counter a, which is an operation near the bathroom entrance, is accumulated.
This operation is an active operation continuing up to 14:29:19, moving quickly at the simultaneous detection area of the two sensors, and e is not reported as a staff operation because it is within three.
As for the operation from 14:30:21, it is judged that the target person has entered the monitoring area since the value of e indicating the operation in the simultaneous detection area of the two sensors subsequently to a exceeds 3 and is sent to the notification unit did.

<Modification 2>
FIG. 13 is an explanatory view of a second modification example in which the bed departure detection system of the embodiment is applied to the case of detecting an operation of walking out of the living room by one person.
FIG. 14 is an explanatory view showing detection areas of the sensor A and the sensor B in the second modification, (a) is a plan view, and (b) is a front view.
As illustrated, the bed leaving detection device 10 is installed beside the exit of the living room so that the central axis B1 of the sensor B crosses the exit of the living room.
The central axis A1 of the sensor A is directed to the indoor side by about 30 ° to 50 ° with respect to the central axis B1 of the sensor B.
As a result, the detection areas of the sensor A and the sensor B overlap at the exit of the room, and the detection area of the sensor A is further expanded to the indoor side.
When passing through the exit to get out of the living room, the subject always passes simultaneously through the detection areas of the sensor A and the sensor B next to the detection area of the sensor A.
In this case, adjustment in the height direction of the sensor A and the sensor B is not necessary.
In the second modification, the detection time interval is set to approximately 2 seconds, m = 5, and n = 3.
In the second modification, the sensor A is installed near the entrance of the room.
The sensor B was installed toward the target person's leg X3 in the door portion.
FIG. 15 (1) shows the change of the accumulated count number of the counter a with the passage of time.
a indicates the number of times the sensor A has detected.
FIG. 15 (2) shows the change of the accumulated count number of the counter b with the passage of time.
b shows the number of times detected by the sensor B.
FIG. 15 (3) shows the change of the accumulated count number of the counter c with the passage of time.
c shows the number of times when the sensor A does not detect continuously.
When the cumulative number exceeds m, the counters a, c, and e are reset to zero.
FIG. 15 (4) shows the change of the accumulated count number of the counter d with the passage of time.
d shows the number of times when the sensor B does not detect continuously.
When the cumulative number exceeds m, the counters b, d and e are reset to zero.
FIG. 15 (5) shows the change of the accumulated count number of the counter e with the passage of time.
When the accumulated count number exceeds n, and when the counter a> the counter b, the notification unit notifies that the target person has entered the monitoring area.
If the cumulative count exceeds n, and Counter b> Counter a, reset staff a and counter e to 0, because the staff other than the target person have entered the room from outside. I do not inform.
FIG. 16 is a graph in which the counters a, b, c, d, and e in FIGS. 15 (1) to (5) are superimposed.

As illustrated, the operation from 14:35:18 to 14:35:35 and the operation from 14:36:09 to 14:38:20 have two sensors because the value of the counter e is within 3. It does not notify it as the operation of the staff who moved quickly in the simultaneous detection area.
In the operation from 14:38:20, the counter e is 4 and exceeds n, and since the counter a> the counter b, it is determined that the object person has entered the monitoring area, and the information is sent to the notification unit.

BE bed 10 Abed detection device 11 base 12 pole 21 communication unit 22 arithmetic processing unit 23 storage unit 24 notification unit A, B sensor A1 central axis of sensor A central axis of sensor B target axis of X sensor B target X 1 upper body X 3 leg BE bed BE1 Bed top view BE2 Bedside

Claims (3)

A sensor A installed on top of a pole standing on a base separate from the bed and installed above the top of the bed to detect the upper body of the subject,
A sensor B installed under the pole erected on the base and installed above the floor surface and below the upper surface of the bed to detect the leg of the subject;
The sensor A and the sensor B are pyroelectric infrared receiving sensors,
It is a bed departure detection system which discriminate | determines a subject's operation | movement based on the output of only said sensor A and sensor B, Comprising:
The sensor A is
Move the center axis A1 inward from the bedside,
The top of the bed is set as the detection range,
The sensor B is
Move the center axis B1 outward from the bedside,
It is installed so that the side of bed is a detection range,
The central axis A1 of the sensor A and the central axis B1 of the sensor B
A bed departure detection system characterized in that they are in a mutually twisted position. The bed leaving detection system according to claim 1 , wherein the installation height of the sensor A and the sensor B is adjustable. The sensor A and the sensor B are
If the number of times e detected the subject simultaneously exceeds a predetermined value,
When the number of times a detected by the sensor A becomes larger than the number b detected by the sensor B,
The bed leaving detection system according to claim 1 or 2 , wherein a signal indicating that the subject person has started bed leaving activity is transmitted from the notification unit.