JP5068602B2 - Bed equipment - Google Patents

Description

  The present invention provides a bed apparatus capable of detecting, with high accuracy, according to the individuality of a bed user, that the bed user is about to get up for elderly persons with dementia and patients who have just been operated on. About.

  Recently, a dementia elderly person's heel and fall / fall accidents around the bed have become social problems, and countermeasures are required. In addition, by monitoring the movement of a user who has been in the bed for a long period of time, such as an elderly person or a patient who has just been postoperatively, using bed load information, it is possible to more quickly in the event of an abnormal situation. It is expected to be able to cope with it.

  The technology disclosed in Patent Document 1 uses weight information to determine whether a user is in the bed or has left the bed, and can monitor the movement of the user on the bed. Can not.

  In order to improve this problem, the techniques disclosed in Patent Documents 2 to 4 and Non-Patent Document 1 determine the position of the center of gravity from the load information of four points on the bed, and use this center of gravity position information to find the floor. It is to monitor the movement of the user at the time.

JP-A-2-280733 Japanese Patent No. 3093745 Japanese Patent No. 3322632 USP 5,276,432 J.C.Barbenel et al., Monitoring the mobility of patients in bed, Medical & Biological Engineering & Computing, pp.466-468 (Sep 1985)

  However, in the conventional techniques described in Patent Documents 2 to 4, it is necessary to lengthen the time for determining the center-of-gravity movement amount in order to detect a slowly rising operation with high accuracy. In this case, there is a problem that this cannot be detected when sleeping after performing the operation of getting up for a long time from the state of getting up for a long time-the operation of getting up.

  In addition, in the monitoring based only on the information on the position of the center of gravity on the bed of the user, for example, it can be detected that there is a user at the end of the bed, but whether it is at the end of the bed due to an operation such as turning over, Changes in the position of the center of gravity due to being at the edge of the bed trying to get out of bed, or placing an item on the bed where the user is sleeping, or another person who is not a user leaning on the bed or sitting down I can't tell you. In addition, when the movement of the center of gravity occurs due to an action such as removing an accessory such as a fence, there is a problem in that it cannot be distinguished from a rising motion and may be erroneously determined.

  Further, in Non-Patent Document 1, in order to monitor the movement of the patient on the bed, the load of the four bed feet is measured by a load cell, the weight of the patient on the bed is measured, and the load measurement value of each bed foot is measured. A technique for calculating the position of the center of gravity on the bed based on the difference between the two and calculating the movement distance of the position of the center of gravity and a technique for determining the state of the patient from the number of movements of the patient on the bed are disclosed.

  However, even in the technique disclosed in Non-Patent Document 1, since the movement of the user on the bed is monitored only by the movement distance of the center of gravity position on the bed, the article is placed on the bed part where the user is sleeping. There is a problem in that it may not be possible to distinguish whether the movement of the center of gravity is caused by placing or another person who is not a user leaning on the bed or sitting down.

  The present invention has been made in view of such problems, and determines the information on the amount of movement of the user's center of gravity in two stages. More preferably, the information on the amount of movement of the center of gravity is combined with the weight information of the user. A detection system that can monitor the movement of the user more accurately, and can monitor the movement of the user with high reliability and with less false detection and high accuracy according to the individuality of the bed user. An object is to provide a bed apparatus provided.

The bed apparatus according to the first aspect of the present application includes a load measuring unit that detects a load on the bed and generates a load signal, a center-of-gravity position calculating unit that calculates a center-of-gravity position of the user based on the load signal, and the center of gravity A center-of-gravity movement amount calculation means for calculating a movement amount of the center-of-gravity position from a position calculation result; a first determination means for determining whether or not the center-of-gravity position movement amount is equal to or greater than a first threshold; and the first The centroid within a second time longer than the first time from the reference time, with a time point before the first time before the time when the determining means has moved the centroid position moving amount greater than or equal to the first threshold. A second determination unit that determines whether or not the position movement amount is equal to or greater than a second threshold that is longer than the first threshold; and the first determination unit determines that the center-of-gravity position movement amount is equal to or greater than the first threshold. Enter the monitoring mode when it is determined that And detecting means for detecting rising of the user when the second determination means determines that the amount of movement of the center of gravity is equal to or greater than a second threshold value that is longer than the first threshold value. And

  The bed apparatus according to a second aspect of the present invention is the bed apparatus according to the first aspect, further comprising weight calculating means for calculating a weight of a user located on the bed portion based on the load signal, and the first determining means. Determines whether the center-of-gravity position movement amount is equal to or greater than a first threshold and the weight is within the second range when a first time has elapsed after the weight has entered the first range. The second determination means sets the time point before the first time from the time point when the first determination means determines that the weight is within the second range as the reference time point. Whether or not the weight at that time is within a third range when the amount of movement of the center of gravity is equal to or greater than a second threshold that is longer than the first threshold within a second time that is longer than one And the detection means is configured so that the first determination means has the weight within the second range. Said second judging means in the monitoring mode enters a monitoring mode when it is determined that the to and detecting the rising of the user when said weight is determined to be within the third range.

The bed apparatus according to a third aspect of the present invention is the bed apparatus according to the first aspect, further comprising weight calculating means for calculating a weight of a user located on the bed portion based on the load signal, and the first determining means. Whether the weight at that time is within the second range when the amount of movement of the center of gravity is equal to or greater than the first threshold within a first time after the weight enters the first range. The second determination means sets the reference time as a reference time that is a time before the first time from the time when the first determination means determines that the weight is within the second range. To whether the weight at that time is within a third range when the amount of movement of the center of gravity is equal to or greater than a second threshold that is longer than the first threshold within a second time that is longer than the first time. The detection means is configured to determine whether the first determination means has the weight within the second range. When the determination is made, the monitor mode is entered, and in this monitoring mode, the rising of the user is detected when the second determination means determines that the weight is within the third range. .

  The bed apparatus according to the fourth aspect of the present invention is the bed apparatus according to the second aspect or the third aspect, wherein the center-of-gravity position movement amount is equal to or greater than a third threshold value when a third time elapses after the weight enters the first range. The third determination means for determining whether or not the weight at that time is within the fourth range, and the third determination means determines that the weight is within the fourth range. Sometimes it has a second detection means for detecting the rising of the user, and a switching means for switching to use either the detection means or the second detection means.

  In these cases, it is preferable to have an alarm means for issuing an alarm when the rising of the user is detected.

  According to the present invention, it is possible to monitor the movement of the user more accurately by determining the amount of movement of the center of gravity of the user in two stages, and preferably by determining the combination of the weight information. In addition, prior to detection of rising, the first determination unit determines whether or not the center-of-gravity position movement amount is equal to or greater than the first threshold value within the first time. Since the second determination means detects rising when it enters the monitoring mode and is in this monitoring mode, the first determination means detects that the user has slightly raised his body at the beginning of rising. When the user wakes up slightly, the monitor enters the monitoring mode and the second determination means detects the rising motion for a long time. Can detect rising. As a result, erroneous detection and reduction in detection accuracy can be prevented, and the reliability of rising detection is improved.

  Hereinafter, a bed apparatus according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings. First, the bed apparatus according to the first embodiment of the present invention will be described. FIG. 1 is a schematic view of the bed apparatus according to the first embodiment of the present invention. FIG. 2 is a schematic view showing an example in which four load sensors 3-1 to 3-4 are arranged at four ends of the bed part 1. FIG. Shows a block diagram when the signal of each load sensor 3 is processed by the controller 5 and each function is operated. As shown in FIG. 1, load sensors 3 (3-1, 3-2) that generate load signals by detecting loads on the bed portion 1 at four corners of a legged frame 2 that supports the bed portion 1. 3-3, 3-4) are provided one by one. The load signal generated by the load sensor 3 is output at regular intervals by a bed leaving prediction / detection system controller 5 (hereinafter referred to as controller 5) provided on one of the wall portions 4 provided on the two short sides of the bed portion 1. Is read.

The controller 5 is provided with a control unit 20, a calculation unit 21, and a storage unit 22, and thereby, the center-of-gravity position calculation unit 12, the center-of-gravity position movement amount calculation unit 13, the various determination units 17, 18, shown in FIG. The determination unit 19 is implemented by software. Further, the controller 5 is provided with an alarm signal transmission unit 31 for transmitting an alarm signal, and further inputs set values such as a first threshold value and a second threshold value of the center-of-gravity position movement amount used for determination. A setting operation unit 24 is provided. Further, the controller 5 includes a storage unit 22 for storing each set value, an alarm display unit 25 for displaying an alarm when a determination result is detected, an alarm signal transmitting unit 31 for transmitting an alarm signal, and a nurse. An alarm / stop operation unit 26 such as a call 29 is provided. Each alarm device transmits an alarm signal from the controller 5 to notify the nurse station 30 via the nurse call 29 or when managing a plurality of beds, a LAN (Local Area Network) access point 27 is connected from a communication connector. It is possible to relay and report to a remote personal computer 28 . And the controller 5 reads the load signal produced | generated by the load sensor 3 for every fixed time.

The center-of-gravity position calculation unit 12 illustrated in FIG. 4 calculates the center-of-gravity position of the user on the bed 1 based on the load signal generated by the load sensor 3 that the controller 5 reads at regular intervals. As shown in FIG. 2, the side connecting the first load sensor 3-1 and the third load sensor 3-3 is the head side, the second load sensor 3-2 and the fourth load sensor 3-4 are The side that connects is the foot side. The distance between the first load sensor 3-1 and the second load sensor 3-2 with the head side left end of the bed 1 (the lower left end of the bed 1 in FIG. 2) as the origin (0, 0). Is B _X , and the distance between the first load sensor 3-1 and the third load sensor 3-3 is _BY . When the user sleeps on the bed 1, W _{1 to} W ₄ are calculated values of the load increase from the reference of the load signals generated by the first to fourth load sensors 3-1 to 3-4. Assuming that (W ₁ + W ₂ + W ₃ + W ₄ = W _T ), the gravity center position (X, Y) of the user can be expressed by the following Equation 1. According to this equation, the center-of-gravity position calculation unit 12 calculates the center-of-gravity position of the user on the bed 1.

The center-of-gravity position movement amount calculation unit 13 obtains the movement amount of the center-of-gravity position as follows. Each time the calculation unit 21 of the controller 5 reads a load signal at predetermined time intervals, the center of gravity position movement amount calculating section 13, dating back only the operation result and the center of gravity movement amount time difference T ₂ of the current centroid position by the gravity center position calculating unit 12 The amount of movement of the centroid position is calculated from the calculation result of the past centroid position. As for the movement when the user gets up, the movement from the supine position to the long sitting position or from the supine position to the long sitting position through the lateral position can be considered, but in any movement, the center of gravity extends from the head side to the foot side in the bed longitudinal direction. Since it is moving, the amount of movement of the center of gravity in the X-axis direction only is taken into account when detecting the rising.

The centroid position of the user at a certain time t ₂ is (X ₂ , Y ₂ ), and the centroid position of the past t _2- T ₂ (X _{2 −T 2} , Y) that is traced back by a centroid movement amount time difference T ₂ from the certain time t _{2. 2−T2} ), the amount of movement ΔX of the center of gravity position in the X-axis direction can be expressed by Equation 2 below. According to this equation, the center-of-gravity movement amount calculation unit calculates the movement amount ΔX of the user's center-of-gravity position on the bed 1. Note that ΔX has directionality because the center of gravity moves from the head side to the foot side when applied to rising detection. This is the reverse of the operation when sleeping. For example, when the value of ΔX is positive, the user gets up, and when the value is negative, it can be determined to be lying down.

  Further, the controller 5 determines whether or not the center-of-gravity position movement amount calculated by the center-of-gravity position movement amount calculation unit 13 is greater than or equal to the first threshold value, and determines whether or not it is greater than or equal to the second threshold value. And a determination unit 18 that performs the determination. These determination results are input to the determination unit 19 to detect rising.

  The determination unit 19 enters the monitoring mode when the determination unit 17 determines that the center-of-gravity position movement amount is equal to or greater than the first threshold value. Then, the determination unit 18 determines that the center-of-gravity position movement amount has become equal to or greater than the second threshold that is longer than the first threshold before the second time that is longer than the first time elapses from the reference time. When the determination is made, the determination unit 19 detects this as a user's rising.

The invention corresponding to the first embodiment is configured as follows. That is, the bed apparatus of the invention corresponding to the first embodiment includes a load measuring unit that detects a load on the bed and generates a load signal, and a center-of-gravity position calculation that calculates the center-of-gravity position of the user based on the load signal. Means, a center-of-gravity movement amount calculation means for calculating a movement amount of the center-of-gravity position from the calculation result of the center-of-gravity position, and a first for determining whether or not the center-of-gravity position movement amount at the first time is equal to or greater than a first threshold value. Determining means, a second determining means for determining whether or not the center-of-gravity position movement amount in a second time longer than the first time is equal to or greater than a second threshold, and the first determining means Entering the monitoring mode when it is determined that the amount of movement of the center of gravity in the first time is equal to or greater than a first threshold, and a time point that goes back by the first time from the time when the monitoring mode is entered is a reference time point, The second determination means is the reference time Detecting means for detecting the rising of the user when it is determined that the amount of movement of the center of gravity from the time until the second time elapses is equal to or greater than the second threshold value. .

In the invention corresponding to the first embodiment, it is not detected whether or not the body weight is in a specific range, but the center-of-gravity position movement amount when the first time has elapsed is equal to or greater than the first threshold value. In addition, when the monitoring mode is entered, a time point that goes back for a first time from the time when the monitoring mode is entered is set as a reference time point, and the center-of-gravity position movement amount at the time point when the second time has elapsed from the reference time point is a second threshold value. When it is above, the rising is detected. In this case, the second time inevitably becomes longer when the user has a purpose of detecting the rising even if the user takes a long time to get up like the present invention. As described above, when the second time is set to be long, the bed user moves from the state where he / she is asleep to the state where he / she goes to sleep, and then the user gets up immediately and then periodically starts up (periodic position of the center of gravity). If only the second time is set as in the prior art, it is not possible to detect the sudden rising after sleeping once as described above. However, in this embodiment , the rising is detected in two stages and the relatively short first time is set. Therefore, such a sudden rising can be detected, and the reliability of the rising detection is improved. To do.

  Next, the first embodiment of the present invention will be described in more detail. FIG. 5 is a diagram showing a rising detection flow according to the first embodiment, and FIG. 6 is a schematic diagram showing the operation thereof. As shown in FIG. 5, when the first time has elapsed (step S41), when the center-of-gravity position movement amount exceeds the first threshold value (step S42), the center-of-gravity position movement amount exceeds the first threshold value. The monitoring time is entered by setting the time point back from the time point exceeding the first time as the reference time point. Then, when the second time has elapsed from the reference time (step S43), it is determined whether or not the center-of-gravity position movement amount exceeds the second threshold as the movement amount from the center-of-gravity position at the reference time (step S44). . As described above, when the moving amount of the center of gravity position from the reference time exceeds the second threshold value, rising is detected (step S45).

  Thus, in the present embodiment, rising is detected in two stages. The first threshold value of the movement amount of the center of gravity position detects an initial stage of rising, and excludes a disturbance such as a load placed on the bed from the rising movement. After the detection of the initial stage of the rising, the center-of-gravity position movement amount is determined based on the second threshold value. The second threshold value is the center-of-gravity position until the bed user raises the upper body on the bed. The amount of movement. The present invention has an object of detecting rising even for a user who takes time to get up. Therefore, the second time t2 (see FIG. 9) inevitably becomes longer. In this way, when the second time t2 is set to be long, the bed user moves from a state where he / she is asleep to a sleeping state, and then a periodical rising operation such as the operation of getting up immediately (the cycle of the center of gravity position). If only the second time t2 is set as in the prior art, it is not possible to detect the sudden rising after sleeping once as described above. However, in the present embodiment, the rising is detected in two stages and the relatively short first time t1 is set. Therefore, such a sudden rising can be detected, and the reliability of the rising detection is improved. improves.

Next, a second embodiment of the present invention will be described. In the second embodiment and the third and fourth embodiments to be described later, the controller 5 is provided with a weight calculator 11. That is, the controller 5 is provided with a control unit 20, a calculation unit 21, and a storage unit 22. By these, the weight calculation unit 11, the centroid position calculation unit 12, the centroid position movement amount calculation unit 13, shown in FIG. Various determination units 14 to 18 and a determination unit 19 are implemented by software. Further, the controller 5 is provided with an alarm signal transmission unit 31 for transmitting an alarm signal, and further, the first range, the second range, the third range of the weight used for the determination, and the center of gravity position movement. A setting operation unit 24 for inputting setting values such as a first threshold value and a second threshold value is provided. Further, the controller 5 includes a storage unit 22 for storing each set value, an alarm display unit 25 for displaying an alarm when a determination result is detected, an alarm signal transmitting unit 31 for transmitting an alarm signal, and a nurse. An alarm / stop operation unit 26 such as a call 29 is provided. Each alarm device transmits an alarm signal from the controller 5 to notify the nurse station 30 via the nurse call 29 or when managing a plurality of beds, a LAN (Local Area Network) access point 27 is connected from a communication connector. It is possible to relay and report to a remote personal computer 28 . And the controller 5 reads the load signal produced | generated by the load sensor 3 for every fixed time.

The weight calculator 11 shown in FIG. 7 calculates the weight of the user on the bed 1 based on the read load signal. Since the bed part 1 is provided with accessories such as mattresses, comforters and fences (not shown), the weight calculation unit uses this state as a reference (= 0 kg, correction of the origin of the center of gravity), and the user There calculates the weight W _T of the user by calculating reads a load signal of the bed section 1 when lying on the bed section 1 by the controller 5, a load increase from the reference.

  The center-of-gravity position calculation unit 12 is as described above. The center-of-gravity position movement amount calculation unit 13 is also as described above.

  On the other hand, the controller 5 has a determination unit 14 for determining whether or not the weight as the calculation result of the weight calculation unit 11 is within the first range, and a determination for determining whether or not the weight is within the second range. The unit 15 is provided with a determination unit 16 that determines whether or not it is within the third range. Further, the controller 5 determines whether or not the center-of-gravity position movement amount calculated by the center-of-gravity position movement amount calculation unit 13 is greater than or equal to the first threshold, and determines whether or not it is greater than or equal to the second threshold. And a determination unit 18 that performs the determination. These determination results are input to the determination unit 19 to detect rising.

  In the determination unit 19, after the determination unit 14 detects that the weight falls within the first range, the time point when the weight falls within the first range is set as a reference time point. When the first time has elapsed, the determination unit 17 determines that the amount of movement of the center of gravity is equal to or greater than the first threshold, and further, the determination unit 15 determines that the weight is within the second range. When entering the monitoring mode. Then, the determination unit 18 determines that the center-of-gravity position movement amount has become equal to or greater than the second threshold that is longer than the first threshold before the second time that is longer than the first time elapses from the reference time. In addition, when the determination unit 16 determines that the weight when the center-of-gravity position movement amount is equal to or greater than the second threshold is within the third range, the determination unit 19 determines that the weight is within the third range. Detecting the rise of

  The bed apparatus of the invention corresponding to the second embodiment calculates the weight of a user located on the bed based on the load measurement means for detecting the load on the bed and generating a load signal based on the load signal. A weight calculating means that calculates the center of gravity position of the user based on the load signal, a center of gravity moving amount calculating means that calculates a moving amount of the center of gravity position from the calculation result of the center of gravity position, First determination means for determining whether the center of gravity position movement amount is equal to or greater than a first threshold and the weight is within the second range when a first time has elapsed after the weight enters the first range. A second time longer than the first time from the reference time, with a time before the first time as a reference time from the time when the first determination means determines that the weight is within the second range. The center-of-gravity position movement amount within the time is equal to the first threshold. A second determination means for determining whether or not the weight at that time is within a third range when the second threshold value is greater than or equal to the long second threshold; and A detecting unit that enters a monitoring mode when it is determined that the user is within the range, and that detects rising of the user when the second determining unit determines that the weight is within the third range in the monitoring mode. It is characterized by having.

  In the invention corresponding to the second embodiment, the rising of the user is detected when the movement amount of the center of gravity is equal to or greater than the second threshold value within the second time. In this case, it is necessary that the weight is within the first range at the reference time, the weight is within the second range when entering the monitoring mode, and the weight is within the third range when rising is detected. To do. This eliminates the movement of the center of gravity due to placing an item on the bed where the user is sleeping, or another person who is not the user leaning on the bed, or sitting down, from the detection of rising, and misjudgment. Can be prevented.

  In addition, prior to detection of rising, when the first time shorter than the second time elapses, the center-of-gravity position movement amount becomes equal to or more than the first threshold shorter than the second threshold, and the weight at that time is within the second range. If it is, the monitor mode is entered, and if it is not this monitor mode, even if the amount of movement of the center of gravity is equal to or greater than the second threshold value, this is not detected as rising. This may require a long time to get up depending on the exercise capacity of the bed user. In this case, the amount of movement of the center of gravity is equal to or greater than the second threshold value within a short time according to the normal user. This is because the amount of movement of the center of gravity is not sufficient for the normal amount of movement (second threshold) when the center of gravity position moves up, and the rising up cannot be detected. On the other hand, if the period for determining that the amount of movement of the center of gravity position is equal to or greater than the second threshold is a long time, false alarms may occur due to patient movement or disturbance during that period. Therefore, in the present invention, the rising of a user who takes a long time to get up is detected with high accuracy by determining the amount of movement in two stages.

Furthermore, in the bed apparatus corresponding to the second embodiment, the time point at which the first time has elapsed is the time point for determining whether or not to enter the monitoring mode. This is the point in time at which the first time has passed beyond the point where the first threshold value has been reached. In this case, it is not always necessary to calculate (at a predetermined control timing) whether or not the amount of movement of the center of gravity exceeds the first threshold value, and the amount of movement of the center of gravity position when the first time elapses. Therefore, it is sufficient to determine whether or not it exceeds the first threshold value, so that the required amount of calculation is reduced and the cost of the apparatus is reduced compared to the invention according to the fourth embodiment of the present invention described later. Is possible.

Next, the operation of the rising detection system in the bed apparatus of the second embodiment will be described. Since the bed part 1 is provided with accessories such as mattresses, comforters and fences (not shown), the weight calculation unit uses this state as a reference (= 0 kg, correction of the origin of the center of gravity), and the user There calculates the weight W _T of the user by calculating reads a load signal of the bed section 1 when lying on the bed section 1 by the controller 5, a load increase from the reference. The center-of-gravity position calculation unit 12 calculates the center-of-gravity position from the load signal, and the center-of-gravity position movement amount calculation unit 13 calculates the movement amount of the center-of-gravity position from this center-of-gravity position.

FIG. 8 shows a flowchart of rising detection in the present embodiment. First, the determination unit 14 as the first determination unit determines whether or not the calculated weight value is within the first range (step S1). If the weight is within the first range, It is determined whether the center-of-gravity position movement amount at the first time has exceeded the first threshold at the time when the time elapses (step S2). Then, it is determined whether or not the weight is within the second range when the amount of movement of the center of gravity exceeds the first threshold (step S4). When the weight is within the second range, the first-stage rising detection is completed and the monitoring mode is entered. Then, the time point at which the weight is determined to be within the second range, that is, the time point that goes back by the first time from the time point at which the rising detection at the first stage is completed is set as the reference time point. And when this 1st time passes, when this gravity center position movement amount does not exceed the 1st threshold value, it returns to step S1. In addition, when the first time has elapsed and the weight is not within the second range, the process returns to step S1.

  In this case, the first range and the second range of weight are close to the weight of the user. Thereby, when the movement of the center of gravity is caused by another person sitting on the bed or removing or attaching an accessory such as a fence on the bed, it can be excluded from detection of rising. In addition, since the detection of rising in the first stage is to detect a state where the user has slightly raised, the user's whole body is on the bed, so the first range and the second range are A value slightly larger and smaller than that centered on the body weight is defined as an upper limit value and a lower limit value, respectively. Further, since the first stage is a state where the user gets up a little, the first threshold value of the movement amount of the center of gravity is a relatively short distance. As a result, the case where the center of gravity moves due to the user turning over on the bed can be excluded from detection of rising. In this way, it is possible to detect that the user has slightly raised his / her body to get up, and to detect that the initial stage of the rising operation has been started. If the weight is not within the second range, the center of gravity position has moved by the first threshold or more due to the above-described disturbance, and the process returns to step S1.

  Next, when the second time has elapsed from the reference time (step S5), the determination unit 18 determines whether the moving amount of the center of gravity position at this time exceeds the second threshold (step S6), and When the center-of-gravity position movement amount exceeds the second threshold, it is determined whether or not the weight when the center-of-gravity position movement amount exceeds the second threshold is within the third range (step S7). If the center-of-gravity position movement amount does not exceed the second threshold value even after the second time has elapsed, the center-of-gravity position corresponding to rising is not moved, so it is detected that it is not rising and the process returns to step S1.

  When the movement amount of the center of gravity from the reference time when the second time has elapsed becomes equal to or greater than the second threshold, and the weight is within the third range, the movement of the center of gravity position is performed by the user. Is detected (step S8). However, if the weight at this time is not within the third range, it is determined that the movement of the center of gravity at this time is not caused by rising, and the process returns to step S1.

  The second threshold value of the center-of-gravity position movement amount is determined based on the movement amount of the center-of-gravity position when a large number of people get up on the bed. In addition, the second time is determined based on the time from the reference time when the elderly person gets up to the completion of the rising time. In particular, in the case of an elderly person, the time required for getting up is a normal user. May significantly exceed the time required to get up. The third range of body weight is wider than the first range and the second range. This is because when the user gets up, the user may sit on the edge of the bed. At this time, the user's foot is on the floor, so the weight measurement calculated by the load detection signal is less than the weight. Is also significantly reduced. For this reason, in particular, the lower limit value of the third range needs to be considerably smaller than the body weight.

  In this way, even when the user gets up very slowly, the rising can be detected based on the weight and the center of gravity position movement amount. When the rising is detected, the alarm device generates an alarm, and the alarm selection unit selects the presence and type of the alarm. While the alarm is being generated, the alarm can be reported to the nurse via the nurse call 29 or the personal computer 28 or the alarm display unit 25 of the controller 5.

  In the present embodiment, the detection of getting up is detected as a first stage in which the user on the bed raises the upper body slightly, and after detecting this and entering the monitoring mode, the upper body of the user moves further greatly. By performing the operation in two stages, such as detecting the operation as the second stage, rising can be detected with high accuracy, and erroneous detection due to disturbance or the like can be prevented.

  The second stage detection is performed after the first stage detection. Even in the second stage detection, the center-of-gravity position movement amount is determined when the weight enters the first range, that is, from the reference time point. The amount of movement. As a result, the second threshold value is determined based on the center-of-gravity position movement amount when rising from the lying state, regardless of the first-stage center-of-gravity position movement amount, and within the first time in the first stage. The second threshold value can be determined regardless of how much the position of the center of gravity has moved.

  Next, a third embodiment of the present invention will be described. In the bed apparatus of the third embodiment, when the weight shifts to the third threshold or more within a third time after the weight enters the first range, the weight at that time is A third determination unit that determines whether or not the weight is within the fourth range; and detecting that the user has risen when the third determination unit determines that the weight is within the fourth range. And a switching means for switching to use one of the detection means and the second detection means.

  In the present embodiment, the operation shown in FIG. 8 and the one-step detection operation can be selected. As shown in FIG. 9, in this one-step detection operation, it is determined whether or not the weight is within the first range (step S11), and the time when the weight falls within the first range is set as the reference time. When the first time has elapsed from this reference time (step S12), the center-of-gravity position movement amount moves from the reference time by a third threshold or more (step S13), and the center-of-gravity position movement amount moves by a third threshold or more. At this point, when the weight is within the fourth range (step S14), rising is detected (step S15).

  In this embodiment, the operation shown in FIG. 8 and the operation shown in FIG. 9 can be switched. As a result, the bed apparatus of the present embodiment selects the operation of FIG. 9 for a user who gets up quickly like a normal person, and shows the case of a person who gets up slowly like an elderly person. 8 operation is selected.

Next, a fourth embodiment of the present invention will be described. The invention corresponding to the fourth embodiment includes a load measuring means for detecting a load on the bed and generating a load signal, and a weight calculation for calculating the weight of a user located on the bed based on the load signal. Means, a center-of-gravity position calculating means for calculating the center-of-gravity position of the user based on the load signal, a center-of-gravity movement amount calculating means for calculating a movement amount of the center-of-gravity position from the calculation result of the center-of-gravity position; A first determination is made as to whether or not the weight at that time is within a second range when the amount of movement of the center of gravity is equal to or greater than a first threshold value within a first time after entering the first range. The determination unit and the first determination unit are longer than the first time from the reference time, with a time point before the first time as a reference time point from the time when the weight is determined to be within the second range. The center-of-gravity position movement amount within the second time is equal to the first threshold value. A second determination means for determining whether or not the weight at that time is within a third range when the second threshold value is greater than or equal to the long second threshold; and A detecting unit that enters a monitoring mode when it is determined that the user is within the range, and that detects rising of the user when the second determining unit determines that the weight is within the third range in the monitoring mode. And.

  In the bed apparatus according to the present invention, the monitoring mode is entered when the center-of-gravity position movement amount is equal to or greater than the first threshold value within the first time and the weight at that time is within the second range. That is, the time point when the monitoring mode is entered is the time point when the moving amount of the center of gravity is equal to or greater than the first threshold value (assuming that the weight is within the second range). In this case, on the condition that the moving amount of the center of gravity position exceeds the first threshold value, the monitor mode is entered, and the rising is detected when the moving amount of the center of gravity position exceeds the second threshold value. When this occurs, the rising can be detected as quickly as possible.

  In the fourth embodiment, the timing at which the monitoring mode is entered is the time when the center-of-gravity position movement amount is equal to or greater than the first threshold value. In the present embodiment, the control mode in the control unit 20 is different from that in the second embodiment. In the determination unit 19, after the determination unit 14 detects that the weight falls within the first range, the time when the weight enters the first range is set as a reference time, and the first time from the reference time The determination unit 17 determines that the center-of-gravity position movement amount is equal to or greater than the first threshold value within one time, and the weight when the center-of-gravity position movement amount is equal to or greater than the first threshold value is When the determination unit 15 determines that it is within the range, the monitoring mode is entered. Then, the determination unit 18 determines that the center-of-gravity position movement amount has become equal to or greater than the second threshold that is longer than the first threshold before the second time that is longer than the first time elapses from the reference time. In addition, when the determination unit 16 determines that the weight when the center-of-gravity position movement amount is equal to or greater than the second threshold is within the third range, the determination unit 19 determines that the weight is within the third range. Detecting the rise of

  Next, the operation of the rising detection system according to the fourth embodiment of the present invention configured as described above will be described. The center-of-gravity position movement amount calculation unit 13 always calculates the movement amount of the center-of-gravity position at a predetermined timing.

  FIG. 10 shows a flowchart of rising detection in this embodiment. First, the determination unit 14 determines whether or not the calculated weight value is within the first range (step S31) and whether the first time has elapsed after the weight has entered the first range. It is determined whether or not (step S32). When the elapsed time from the reference time exceeds the first time, the process returns to step S31. If the elapsed time from the reference time is before the first time elapses, it is determined whether or not the center-of-gravity position movement amount at the first time has exceeded the first threshold (step S33). ). If the amount of movement of the center of gravity does not exceed the first threshold value, the process returns to step S31. Then, the determination unit 15 determines whether the weight is in the second range when the center-of-gravity position movement amount exceeds the first threshold (step S34), and the weight is in the second range. Is completed, the first-stage rising detection is completed, and the monitoring mode is entered. Further, a time point that goes back by the first time from the time when the monitoring mode is entered is set as the reference time point.

In this case, the first range and the second range of weight are close to the weight of the user. Thereby, when the movement of the center of gravity is caused by another person sitting on the bed or removing or attaching an accessory such as a fence on the bed, it can be excluded from detection of rising. In addition, since the detection of rising in the first stage is to detect a state where the user has slightly raised, the user's whole body is on the bed, so the first range and the second range are A value slightly larger and smaller than that centered on the body weight is defined as an upper limit value and a lower limit value, respectively. Further, since the first stage is a state where the user gets up a little, the first threshold value of the movement amount of the center of gravity is a relatively short distance. As a result, the case where the center of gravity moves due to the user turning over on the bed can be excluded from detection of rising. In this way, it is possible to detect that the user has slightly raised his / her body to get up, and to detect that the initial stage of the rising operation has been started. If the weight is not within the second range, the center of gravity position has moved by the first threshold or more due to the above-described disturbance, and the process returns to step S31 .

  Next, when the second time has elapsed from the reference time (step S35), the determination unit 18 determines whether the gravity center position movement amount at this time exceeds the second threshold (step S36), and the reference time When the center-of-gravity position movement amount exceeds the second threshold, it is determined whether the weight when the center-of-gravity position movement amount exceeds the second threshold is within the third range (step S37). ). If the center-of-gravity position movement amount does not exceed the second threshold value even after the second time has elapsed, the center-of-gravity position that does not rise is not moved.

  When the movement amount of the center of gravity from the reference time when the second time has elapsed becomes equal to or greater than the second threshold, and the weight is within the third range, the movement of the center of gravity position is performed by the user. Is detected (step S38). However, if the weight at this time is not within the third range, it is determined that the movement of the center of gravity at this time is not caused by rising, and the process returns to step S31.

In the fourth embodiment, the same effects as in the second embodiment are obtained. In the fourth embodiment, the difference from the second embodiment is how to grasp the timing of entering the monitoring mode. In the second embodiment, it is determined whether the center-of-gravity position movement amount has exceeded the first threshold when the first time has elapsed from the reference time point. In the fourth embodiment, from the reference time point. Before the first time elapses, it is always determined within the first time whether or not the center of gravity position movement amount has exceeded the first threshold value. For this reason, in the fourth embodiment, it is possible to sensitively detect the initial motion of rising in the first stage of rising detection. However, in the fourth embodiment, the initial action is sensitively detected, but the possibility that a disturbance that does not get up is detected as the first stage of getting up is greater than in the second embodiment . In the fourth embodiment, the load of the calculation process of the center-of-gravity position movement amount is large. That is, in the second embodiment, data on the center of gravity position for a fixed time is always stored. However, when calculating the center of gravity position movement amount, one center of gravity position data at the reference time point and the current center of gravity are calculated. What is necessary is just to calculate a gravity center position movement amount by comparing with position data. On the other hand, in the case of the fourth embodiment, similarly, the center of gravity position data for a fixed time is always stored, and all the data and the current center of gravity position data are always compared to determine the center of gravity position. It is necessary to calculate the amount of movement. Therefore, in the case of the fourth embodiment, it is necessary that the processing capability of the calculation unit is high. In the first embodiment, the predetermined time is the first time in the case of detection of rising at the first stage, and is shorter than the second time in the case of detection of rising at the second stage. This is the time from the time point to the time point when the amount of movement of the center of gravity exceeds the second threshold. Further, in the fourth embodiment, the predetermined time is shorter than the first time in the case of detection of rising at the first stage, and from the reference time point to the time point when the center of gravity position movement amount exceeds the first threshold value. In the case of detection of rising in the second stage, the time is shorter than the second time and is the time from the reference time point to the time point when the center of gravity position movement amount exceeds the second threshold value.

It is the schematic of the bed apparatus which concerns on 1st Embodiment of this invention. 4 is a schematic view showing an example in which four load sensors 3-1 to 3-4 are arranged at four ends of the bed part 1. FIG. The block diagram when the signal of each load sensor 3 is information-processed by the controller 5 and each function is operated is shown. It is a block diagram which shows the structure of the bed apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the flow of the rising detection of the bed apparatus which concerns on 1st Embodiment of this invention. It is a figure which similarly shows operation | movement of 1st Embodiment. It is a block diagram which shows the structure of the bed apparatus which concerns on 2nd Embodiment of this invention. It is a figure which similarly shows the flow of the rising detection. It is a figure which shows the flow of the rising detection of the bed apparatus which concerns on 3rd Embodiment of this invention. It is a figure which shows the flow of the rising detection of the bed apparatus which concerns on 4th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1; Bedding part 2; Frame 3; Load sensor 3-1; 1st load sensor 3-2; 2nd load sensor 3-3; 3rd load sensor 3-4; 4th load sensor 4; Part 5; bed leaving prediction / detection system controller 6; edge sitting position detection region 11; weight calculation part 12; center of gravity position calculation part 13; center of gravity position movement amount calculation part 14, 15, 16, 17, 18; determination part 19; 20; Control unit 21; Calculation unit 22; Storage unit 23; Operation display unit 24; Setting operation unit 25; Alarm display unit 26; Alarm / stop operation unit 27;
28; PC 29; Nurse call 30; Nurse station 31; Alarm signal transmitter

Claims (5)

A load measuring means for detecting a load on the bed portion and generating a load signal; a centroid position calculating means for calculating a centroid position of the user based on the load signal; and a shift amount of the centroid position based on the calculation result of the centroid position. Centroid movement amount calculating means for calculating the centroid position, first determination means for determining whether or not the centroid position movement amount is equal to or greater than a first threshold, and the first determination means that the centroid position movement amount is The time point before the first time from the time point that is equal to or greater than the threshold value of 1 is used as the reference time point, and the center-of-gravity position movement amount is greater than the first threshold value within a second time period that is longer than the first time point from the reference time point. A second determination unit that determines whether or not the second threshold value is longer than the second threshold value, and enters the monitoring mode when the first determination unit determines that the center-of-gravity position movement amount is equal to or greater than the first threshold value. In this monitoring mode, the second determination means Bed apparatus whose serial gravity position movement amount and having a detecting means for detecting the rising of the user when it is determined that a first long second threshold value or more than the threshold value. Furthermore, it has a weight calculating means for calculating the weight of the user located on the bed based on the load signal, and the first determining means is configured to include a first weight after the weight falls within a first range. When the time elapses, the center-of-gravity position movement amount is equal to or greater than a first threshold value, and it is determined whether the weight is within a second range, and the second determination means is the first determination means. The center-of-gravity position movement amount within a second time longer than the first time from the reference time, with a time before the first time from the time when the weight is determined to be within the second range as a reference time Is determined to determine whether the weight at that time is within a third range when the value becomes equal to or greater than a second threshold value that is longer than the first threshold value. When it is determined that the weight is within the second range, the monitor mode is entered and the monitor mode is entered. Bed apparatus according to claim 1, characterized in that to detect the rising of the user when said second determination means determines that the body weight is within the third range Te. Furthermore, it has a weight calculating means for calculating the weight of the user located on the bed based on the load signal, and the first determining means is configured to include a first weight after the weight falls within a first range. When the amount of movement of the center of gravity is equal to or greater than the first threshold value within the time period, it is determined whether or not the weight at that time is within the second range, and the second determination means includes the first determination unit The centroid within a second time longer than the first time from the reference time, with a time before the first time as a reference time from the time when the determination means determines that the weight is within the second range. When the amount of position movement becomes equal to or greater than a second threshold value that is longer than the first threshold value, it is determined whether the weight at that time is within a third range, and the detection means is configured to determine the first determination value. When the means determines that the weight is within the second range, it enters a monitoring mode and enters this monitoring mode. There are bed apparatus according to claim 1, characterized in that said second judging means detects the rising of the user when said weight is determined to be within the third range. Whether or not the weight at that time is within the fourth range when the amount of movement of the center of gravity is equal to or greater than a third threshold value after the third time has elapsed after the weight has entered the first range. Third determination means for determining, second detection means for detecting the rising of the user when the third determination means determines that the weight is within the fourth range, and the detection means The bed apparatus according to claim 2, further comprising: a switching unit that switches to use one of the second detection units. The bed apparatus according to any one of claims 1 to 4, further comprising alarm means for issuing an alarm when the user's rising is detected.

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