JP2005007067A - Apparatus and method for detecting bedridden person - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and a method for detecting a bedridden person which realize prevention of the bedridden person from falling from a bed by enabling the bedridden person in one side in the bed to be surely detected while suppressing an increase in cost and a deterioration in the feel of the bed as much as possible. <P>SOLUTION: A first pressure-sensitive sensor 21 and a second pressure-sensitive sensor 22 each consisting of a cable shape pressure-sensitive sensor, are arranged along a lying direction at both end sides of a lying surface 15a on which the bedridden person lies. Output signals from the first and second pressure-sensitive sensors 21, 22 are inputted to a first signal processing part and a second signal processing part where the output signals are amplified, filtered and smoothed. Intensity ratio between the output signals of the respective sensors 21, 22 outputted from the first and second signal processing parts is acquired. When the ratio falls within the range of a predetermined prescribed one-side state, it is determined that the bedridden person is in one side on the lying surface 15a. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a detection apparatus and a detection method for a bedridden person that detects a shift in the position of the bedridden person on the floor.
[0002]
[Prior art]
In recent years, as a bed installed in a hospital or various care facilities, it has been considered that a bed is provided with a pressure-sensitive sensor that detects the presence / absence of a caregiver who is a bedridden or a change in physical condition (for example, a patent) Reference 1). In this bed, a plurality of sensors that generate a minute voltage due to the piezoelectric effect are arranged on the bed surface on which the bedridden lies in the width direction of the bed, and a row of the arranged sensors is arranged on the bed. A plurality of rows are arranged at predetermined intervals in the longitudinal direction, and the voltage from these sensors is detected to check the presence / absence of the care recipient who is the bedridden and to manage the change in physical condition.
In addition, a long tape-like piezoelectric sensor is arranged on the upper surface of the bed in the width direction, and the blood pressure value and arteriosclerosis degree of the bedridden are determined by this piezoelectric sensor (for example, Patent Document 2). reference).
[0003]
[Patent Document 1]
JP-A-7-88089
[Patent Document 2]
Japanese Patent Laid-Open No. 10-229973
[0004]
[Problems to be solved by the invention]
By the way, in the bed in which a plurality of sensors composed of a large number of piezoelectric elements are provided on the bed surface on which the bed person lies as in Patent Document 1, a large number of expensive sensors are arranged in a lattice shape. Therefore, the increase in cost is unavoidable, the sensitivity of the sensor itself is relatively low, and the sensor has to be provided almost directly above the bed surface on which the bed layer lies, impairing the sleeping comfort.
In addition, in the case of a bed in which a long tape-shaped piezoelectric sensor is arranged in the width direction, the presence or absence of the bedridden can be detected, but the position of the bedbed person on the bed is monitored and falls, etc. In addition, in this bed, the piezoelectric sensor is provided on the floor on which the bedridden lies, so that the sleeping comfort is unavoidable.
[0005]
The present invention has been made in view of the above circumstances, and it is possible to reliably detect the deviation of the position of the bedridden and prevent the fall while preventing the increase in cost and the deterioration of the sleeping comfort as much as possible. An object of the present invention is to provide a detection device and a detection method for a bedridden person.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the detection apparatus for a bedridden according to claim 1 is a detection apparatus for a bedbed person that detects a deviation of the position of the bedbed person on the floor, A first pressure sensor in the form of a cable that is individually disposed along the side of the bed surface at both ends in the width direction of the surface and detects a component of acceleration due to the movement of the bed person and outputs a signal; A second pressure sensor, and a determination means for comparing the output signals from the first pressure sensor and the second pressure sensor to determine a shift state of the bed person toward the bed surface side. It is characterized by having.
[0007]
According to this detection apparatus for a bedridden person, the first pressure sensor and the second pressure sensor composed of a cable-shaped pressure sensor are disposed at positions along the sides of the bed surface on both ends of the bed surface. Then, the determination means compares the output of the signals from the first pressure sensor and the second pressure sensor, and determines the lateral shift of the position of the bed person on the bed surface. Therefore, it is possible to prevent the fall of the bedridden from the bed surface from the determination result. In addition, since a cable-shaped pressure-sensitive sensor is simply arranged along both sides of the flooring surface, cost increases can be minimized as compared with a case in which a plurality of sensors are arranged in a grid pattern vertically and horizontally. In addition, the deterioration of sleeping comfort can be suppressed as much as possible.
[0008]
The detection apparatus for a bedridden according to claim 2, wherein the first pressure sensor and the second pressure sensor set a wiring density on the head side of the bedridden higher than other areas. Features.
[0009]
According to the detection device for the bedridden person, since the wiring density of the pressure-sensitive sensor on the bedside of the bedridden person is increased, the detection sensitivity for the head is particularly improved. Therefore, even when the bedside has a deviation such that the head is close to the side edge, the head of the bedbed can be detected with high sensitivity, Can be accurately and reliably grasped.
[0010]
The detection device for a bedridden according to claim 3, wherein the first pressure sensor and the second pressure sensor set a disposition density on the lower limb side of the bedlock lower than other regions. Features.
[0011]
According to the detection apparatus for the bedridden person, since the density of the pressure-sensitive sensors on the lower leg side of the bedridden person is lowered, the detection sensitivity on the lower leg side is lowered. Therefore, it eliminates the problem of misjudging that the position of the bedded person is offset, especially when the bedded person is lying on the center with the legs open and lying in the center. Can do.
[0012]
The detection device for a bedridden according to claim 4, wherein the first pressure sensor and the second pressure sensor are each wired in a wavy shape on the floor surface, and the wiring density is determined by an arrangement interval of the wavy waves. It is characterized by having changed.
[0013]
The detection device for the bedridden person can set the wiring density simply and arbitrarily by changing the wiring density according to the wave-like wave arrangement interval in which the pressure-sensitive sensors are wired in a wave shape.
[0014]
The detection device for a bedridden according to claim 5 is characterized in that a protrusion piece is disposed on the upper side or the lower side of the pressure sensor, and the protrusion pieces overlap at a plurality of locations of the pressure sensor. .
[0015]
According to the detection device for the bedridden person, the protrusion pieces are arranged on the upper side or the lower side of the pressure sensor so as to overlap at a plurality of places. It can be made to act locally as a large force, whereby a large signal can be output, and the detection sensitivity of the deviation of the position of the bedridden person can be increased.
[0016]
The detection apparatus for a bedridden according to claim 6, wherein the pressure-sensitive sensor and the protruding piece are each attached to a sheet, and the pressure-sensitive sheet and the protruding sheet to which the pressure-sensitive sensor and the protruding piece are attached are provided. Are superimposed on each other.
[0017]
According to the detection device for the bedridden person, the pressure-sensitive sensor provided with the pressure-sensitive sensor and the protruding sheet provided with the protruding piece are simply overlapped with each other, thereby improving the sensitivity of the pressure-sensitive sensor with a very simple configuration. Can be made.
[0018]
The detection apparatus for a bedridden according to claim 7, wherein the determination unit outputs a notification signal when the determination unit determines that the position of the bedbed person on the floor is shifted, and the determination The apparatus is characterized by comprising a notification means for receiving a notification signal output from the means and notifying that a deviation has occurred.
[0019]
According to the detection device for the bedridden person, the notification unit performs notification in response to the notification signal output from the determination unit, so that the deviation of the position of the bedridden person, for example, to a third party such as a care recipient It is possible to notify promptly and to quickly correct the offset.
[0020]
The detection method of a bedridden according to claim 8 is a detection method of a bedbed person detecting a shift of the position of the bedbed person on the bed surface, at both ends in the width direction of the bed surface, Outputs from the cable-like first pressure sensor and the second pressure sensor, which are individually arranged along the side of the bed surface and detect the acceleration component due to the movement of the bed person and output a signal. A signal intensity ratio is obtained, and when the ratio falls within a predetermined range, it is determined that a deviation has occurred in the position of the person on the floor.
[0021]
According to the detection method of the bedridden person, the ratio of the intensity of the output signal from the first pressure sensor and the second pressure sensor is obtained, and when this ratio is out of a predetermined range, By determining that the deviation of the position of the bedridden on the surface has occurred, it is possible to accurately and reliably detect the deviation of the position of the bedridden person with a simple configuration.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a detection apparatus and a detection method for a bedridden person according to the present invention will be described in detail with reference to the drawings.
(First embodiment)
1 is an exploded perspective view of a bed provided with a detection device for a bedridden person according to the first embodiment, FIG. 2 is a plan view of a pressure-sensitive sheet constituting the detection device, and FIG. 3 is a protrusion of a pressure-sensitive sensor and a protruding sheet. FIG. 4 is a cross-sectional view taken in the direction of the arrow P in FIG. 3, and FIG. 5 is an exploded perspective view of the pressure-sensitive sensor disposed on the pressure-sensitive sheet.
[0023]
As shown in FIG. 1, the bed 100 is assembled by stacking a protruding sheet 11, a pressure sensitive sheet 13, and a mattress 15 in this order on the floor surface 10 a of the frame 10.
The protruding sheet 11 has a plurality of protruding pieces 17 formed in parallel on the upper surface side along the longitudinal direction of the bed 100. The protruding pieces 17 are not limited to the illustrated linear continuous plural rows, but may be linear and intermittent protrusions, curved protrusions or discrete protrusions. A pressure sensitive sheet 13 constituting a detection device is overlaid on the upper surface of the protruding sheet 11 with the pressure sensor facing down, and the upper surface of the mattress 15 superimposed on the upper surface of the pressure sensitive sheet 13 becomes the floor 15a. .
[0024]
As shown in FIG. 2, the pressure-sensitive sheet 13 is sewn to, for example, the sheet 19 with a sheet 19 having a rectangular shape in a plan view formed from a flexible nonwoven fabric, and spaced from each other at both ends of the sheet 19. It has a pair of pressure-sensitive sensors 21 and 22 stuck by things.
[0025]
The pressure-sensitive sensors 21 and 22 are long cable-shaped piezoelectric sensors using a piezo element material, and linear portions 21a and 22a arranged linearly along the edges on both ends of the sheet 19, and The corrugated portions 21b and 22b are disposed at the inner position of the sheet 19 relative to the straight portions 21a and 22a. And these pressure-sensitive sensors 21 and 22 cross | intersect by the planar view with respect to the projection piece 17 of the projection sheet | seat 11 in which the wavy parts 21b and 22b are spread | laid below, as shown in FIG. As a result, the pressure-sensitive sheet 13 having the pressure-sensitive sensors 21 and 22 passes through the mattress 15 as shown in FIG. 4 due to the weight and body movement of the bedridden lying on the floor 15a of the mattress 15. A part of the wave-like portions 21 b and 22 b of the pressure sensors 21 and 22 is pressed down against the protruding piece 17 of the protruding sheet 11 by being pushed down. In this way, the load from the bedridden person is locally pressed against the pressure-sensitive sensors 21 and 22 that intersect with the protruding pieces 17. Therefore, the deformation amount of the pressure sensitive sensors 21 and 22 increases, and the displacement of the bedridden person is not only in the direction of the wave amplitude (the width direction of the bed) but also in the direction perpendicular to the direction (the longitudinal direction of the bed). ), This displacement can be reliably detected.
[0026]
Next, a specific configuration of the pressure sensitive sensors 21 and 22 will be described.
As shown in FIG. 5, the pressure-sensitive sensors 21 and 22 have a coiled center electrode 23 at the center in the axial direction, and a piezo element material 25 is covered around the center electrode 23, and further, the outer periphery thereof is outside. The electrode 27 is disposed, and the outermost periphery is covered with an outer cover 29 such as a vinyl chloride resin.
[0027]
The pressure-sensitive sensors 21 and 22 use a heat-resistant resin material capable of operating up to 120 ° C. for the piezo element material 25, and a conventional typical polymer piezo element material (uniaxially stretched polyfluorination). Vinylidene), chloroprene, and piezoelectric ceramic powder piezo element materials have characteristics that can be used in a temperature range higher than 90 ° C. (120 ° C. or lower), which is the maximum use temperature.
[0028]
The piezo element material 25 is composed of a flexible resin and piezoelectric ceramic, and a coil-shaped metal is used as the center electrode 23 and a film-like flexible electrode is used as the outer electrode 27, so that a normal It has the same flexibility as a vinyl cord.
Furthermore, the pressure-sensitive sensors 21 and 22 are as sensitive as polymer piezo element materials, and have the same high sensitivity as polymer piezo element materials in a low-frequency region (10 Hz or less) where human movement is detected. is doing. This is because the relative dielectric constant (about 55) of the piezo element material 25 is larger than that of the polymer piezo element material (about 10), so that the decrease in sensitivity is small even in the low frequency region (10 Hz or less).
[0029]
The piezo element material 25 is composed of a composite of a resin-based material and a piezoelectric ceramic powder of 10 μm or less, and vibration detection characteristics are realized by ceramic, and flexibility is realized by resin.
This piezo element material 25 uses chlorinated polyethylene as a resin-based material to achieve high heat resistance (120 ° C.) and flexibility that can be easily formed, and enables a simple manufacturing process that does not require crosslinking. To do.
[0030]
Since the pressure-sensitive sensors 21 and 22 thus obtained do not have piezoelectric performance when the piezo element material 25 is molded, by applying a DC high voltage of several kV / mm to the piezo element material 25, It is necessary to perform a process (polarization process) for imparting piezoelectric performance to the piezo element material 25. This polarization process is performed by forming a central electrode 23 and an outer electrode 27 on the piezoelectric element material 25 and then applying a DC high voltage to both the electrodes 23 and 27.
[0031]
When a minute defect such as a crack is inherent in the piezo element material 25, it is easy to short-circuit between the two electrodes by discharging at the defective part, so that a sufficient polarization voltage cannot be applied. Then, by establishing a unique polarization process using an auxiliary electrode that can be in close contact with the piezo element material 25 of a certain length, it is possible to detect and avoid defects and stabilize the polarization, thereby increasing the length of several tens of meters or more. Will also be possible.
[0032]
Further, in the pressure sensitive sensors 21 and 22, a coiled metal center electrode is used for the center electrode 23, and a film electrode (aluminum-polyethylene terephthalate-aluminum three-layer laminate film) is used for the outer electrode 27, whereby a piezo element is obtained. While ensuring the adhesiveness of the material 25 and each electrode 23 and 27, an external lead wire can be connected easily and a flexible cable-like mounting structure is attained.
[0033]
The center electrode 23 is a copper-silver alloy coil, the outer electrode 27 is a three-layer laminate film made of aluminum-polyethylene terephthalate-aluminum, the piezo element material 25 is polyethylene-based resin + piezoelectric ceramic powder, and the outer cover 29 is thermoplastic. As a result, the relative dielectric constant is 55, the charge generation amount is 10 to 13 C (coulomb) / gf, and the maximum use temperature is 120 ° C.
[0034]
The pressure sensitive sensors 21 and 22 output a signal only at the moment when force is applied, and thereafter no longer output a signal as long as there is no fluctuation even if force is continuously applied. Similarly, when the force is removed, it has a characteristic to detect acceleration that is output only at that moment. Therefore, even if the pressure sensors 21 and 22 are bent and arranged, output is generated at the moment of bending, but no output is provided after the arrangement is completed, and thereafter, the pressure sensors 21 and 22 Output is generated when force is applied to some part.
Therefore, even if the cord-shaped piezoelectric sensor is bent and laid in a wave shape at the bottom of the bed, the output is not output after the laying is completed, although it is turned on at the moment of bending. After that, an output is output only when a force is applied to some part of the cord-shaped piezoelectric sensor.
[0035]
Next, the configuration and function of the in-bed detection device will be described in more detail.
FIG. 6 is a block diagram showing the configuration and function of the detection apparatus.
One of the pair of pressure sensors 21 and 22 provided on the pressure sensitive sheet 13 is a first pressure sensor 21 and the other is a second pressure sensor 22.
[0036]
The first pressure sensor 21 is connected to the first signal processing unit 31, and the second pressure sensor 22 is connected to the second signal processing unit 33. In each signal processing unit 31, 33, the output signal from each pressure sensor 21, 22 is input to the amplification circuit 35.
The first signal processing unit 31 and the second signal processing unit 33 have a filter 37 and a smoothing circuit 39 in the subsequent stage of the amplification circuit 35, and output signals from the first pressure sensor 21 and the second pressure sensor 22 are amplified. The signal is amplified by the circuit 35, filtered to a required frequency component by the filter 37, and the signal waveform is smoothed by the smoothing circuit 39.
[0037]
The first signal processing unit 31 and the second signal processing unit 33 are respectively connected to the determination unit 41, and the electric signal smoothed by the smoothing circuit 39 is input to the determination unit 41.
The determination means 41 determines the deviation of the position of the bedridden lying on the floor 15a of the mattress 15 based on the electrical signals from the first signal processing unit 31 and the second signal processing unit 33. .
[0038]
Furthermore, a notification means 43 is connected to the determination means 41. The notification unit 43 includes, for example, a voice output unit such as a speaker, or a display unit such as a display. The determination unit 41 outputs a notification signal to the notification unit 43 based on the determination result of the deviation of the position of the bedridden person. And when the alerting | reporting means 43 receives the alerting | reporting signal from the determination means 41, it will alert | report that the position of the bedridden person in the floor 15a has shifted | deviated by issuing a warning by an audio | voice or a display, or these combination. .
The first pressure sensor 21 and the second pressure sensor 22 are each connected to a power source 47 via a resistor circuit 45, and a driving voltage for detection is applied in advance from the power source 47 via the resistor circuit 45. .
[0039]
The determination means 41 is a fragment of the position of the bedridden person based on the ratio of the intensity of the electric signals from the first signal processing unit 31 and the second signal processing unit 33 (using signal amplitude, peak integration intensity, etc.). Judgment is made. Specifically, as shown in FIG. 7, a table that defines the range of occurrence of deviation with respect to the ratio of the intensity of the electric signal outputs A and B from the first signal processing unit 31 and the second signal processing unit 33 is created in advance. In addition, comparing the outputs A and B from the first signal processing unit 31 and the second signal processing unit 33, whether the intensity ratio of these outputs A and B is within a predetermined offset state range, Alternatively, it is determined whether it is within the range of no deviation.
[0040]
Then, the determination unit 41 has a case in which the ratio of the intensities of the outputs A and B from the first signal processing unit 31 and the second signal processing unit 33 is out of the non-shifted state range and in the shifted state range. Then, it is determined that the position of the bedridden person on the floor 15 a is shifted, and a notification signal is output to the notification means 43.
In the notification means 43, when a notification signal is input, for example, a warning is given to a third party such as a caregiver by voice or display, or a combination thereof, and the position of the bedridden person on the floor 15a is offset. Inform you.
[0041]
Here, in a bed equipped with a detection device for a bedridden person having the above-described configuration, in order to correct individual differences with respect to the bedridden person, the detection accuracy can be greatly improved by performing adjustment prior to the deviation detection. it can. As specific adjustment work, first, as shown in FIG. 8A, the determination means 41 is set in the state where the bedridden H is laid between the first pressure sensor 21 and the second pressure sensor 22. An adjustment knob (not shown) provided is turned so that the intensity of the output A from the first signal processing unit 31 and the intensity of the output B from the second signal processing unit 33 are substantially matched.
[0042]
In the state after this adjustment, when the bed person H on the bed surface 15a moves on the bed surface 15a as shown in FIG. 8B or FIG. The load applied to the pressure-sensitive sensor 22 changes, and due to the change in the load, the pressing force of the protruding piece of the protruding sheet 11 against the pressure-sensitive sensor also changes greatly and is detected from the first pressure-sensitive sensor 21 and the second pressure-sensitive sensor 22. A signal is output. In the case of FIG. 8B, the head of the bedridden H is on the first pressure sensor 21 and the foot is on the second pressure sensor 22, but the head is heavier than the foot. The head sinks deeply into the mattress 15, and the output of the pressure sensor by the head becomes larger than the output by the foot, and as a result, the difference in signal strength between the outputs A and B increases. Thereby, the offset state of the bedridden person is detected. In this case, the deviation detection can be performed by a large load fluctuation when the bedded person H is in the deviation state. Vibrations are detected in the pressure-sensitive sensors 21 and 22 due to the weak body movement caused by the above, and it is possible to determine whether or not the state is shifted by comparing the magnitudes of the vibrations.
In particular, in the offset state where the possibility of falling is high as shown in FIG. By classifying the notification level according to the magnitude of the difference in the intensity of the output signal, it is possible to notify the case where urgent action is required.
At this time, the tensile force generated when the mattress 15 sinks due to the body weight of the bedridden H acts on the straight portions 21a and 22a of the first and second pressure sensors 21 and 22, and a detection signal is generated also by this. By doing so, the detection sensitivity is further improved.
[0043]
As described above, according to the above-described detection apparatus and detection method for the bedridden person, the first pressure sensor 21 and the second pressure sensor 22 that are cable-shaped pressure sensors are installed at both ends of the bed surface 15a. The determination means 41 compares the outputs of the signals from the first pressure sensor 21 and the second pressure sensor 22 and is disposed along the side of the floor surface 15a. Therefore, it is possible to grasp the bedded state of the bedridden from the determination result, and to prevent the falling from the bedbed surface 15a in advance.
[0044]
Further, since the cable-like pressure-sensitive sensors are simply disposed on both ends of the floor surface 15a, a large number of sensors composed of expensive piezoelectric elements are arranged in a lattice pattern with an interval in the width direction and the longitudinal direction of the bed. Cost increase can be suppressed as much as possible as compared with the individual arrangement.
[0045]
Further, since the pressure sensitive sensors 21 and 22 themselves are extremely high sensitivity sensors, even if the pressure sensitive sheet 13 provided with the pressure sensitive sensors 21 and 22 is disposed below the mattress 15, sufficient detection is possible. Sensitivity can be obtained, and problems such that the pressure-sensitive sensors 21 and 22 affect sleeping comfort can be eliminated. Further, even when the pressure sensitive sensors 21 and 22 are disposed immediately below the floor 15a, the pressure sensors 21 and 22 themselves are not disposed at the center of the floor 15a. Since it also has flexibility, it is possible to suppress the deterioration of sleeping comfort as much as possible.
[0046]
In addition, the detection sensitivity of the pressure sensitive sensors 21 and 22 can be extremely easily improved by simply overlapping the pressure sensitive sheet 13 provided with the pressure sensitive sensors 21 and 22 and the protruding sheet 11 provided with the protruding pieces 17. be able to.
[0047]
In the above embodiment, the pressure sensitive sheet 13 provided with the pressure sensitive sensors 21 and 22 is stacked with the protruding sheet 11 having the protruding pieces 17 to improve the sensitivity. However, as a structure for improving the sensitivity, The following configuration is also possible.
[0048]
In the example shown in FIG. 9, for example, pressure sensitive sensors 21 and 22 are attached to one sheet 51 with respect to two sheets 51 and 52 such as nonwoven fabric, and a protruding piece 53 made of a wire or the like is attached to the other sheet 52. The pressure sensitive sheet 55 is formed by stacking these sheets 51 and 52 on each other. When the pressure sensitive sheet 55 is used, the above-described protruding sheet 11 is not necessary, and the configuration can be simplified. And also by this structure, the load from a bedridden can be made to act on the pressure sensitive sensors 21 and 22 locally as a big force by the projection piece 53, and the improvement of a sensitivity can be aimed at. Of course, the position of the protruding piece 53 with respect to the pressure-sensitive sensors 21 and 22 may be lower or upper.
[0049]
In addition, the heart rate of the bedridden can be detected by the pressure-sensitive sensors 21 and 22, and the health condition of the bedridden can be managed based on the detection result.
[0050]
(Second Embodiment)
Next, a second embodiment of the detection apparatus and detection method for a bedridden person according to the present invention will be described.
FIG. 10 is a schematic plan view of a pressure-sensitive sheet constituting the bedridden detection device according to the second embodiment.
The pressure-sensitive sheet 61 has an increased wiring density by reducing the wave-like wave arrangement interval of the pressure-sensitive sensors 21 and 22 in the area Wa on the bedded person's head lying on the floor 15a. Yes. On the contrary, in the area Wc on the lower limb side of the bedridden lying on the bedbed surface 15a, the arrangement interval of the wavy waves of the pressure sensors 21 and 22 is widened, and the wiring density is lowered. (The figure shows an example in which the wiring density is set to the minimum in a straight line in the direction of bedtime).
[0051]
Here, in general, when the bedridden lies, as shown in FIG. 11, a large load is applied to the bed surface 15a at the head, back and buttocks (buttock), and a very large load is applied at the lower limbs. Absent. In particular, the deviation of the position of the bedridden person greatly affects the deviation of the position of the head. For this reason, in this embodiment, the pressure-sensitive sensors 21 and 22 are made dense at the head side so that they can be detected even with slight movements, and are relatively low in movement on the lower limb side, which can be a false detection factor. Density.
[0052]
And in the detection apparatus of the bedridden according to this embodiment, as shown in FIG. 12A, the bedded person H is slanted to a slight extent on the pressure sensor 21 in the area Wa on the bedbed surface 15a. Even in the case where a deviation occurs, the deviation of the head position of the bedridden H can be reliably detected with high sensitivity.
[0053]
Moreover, since the pressure-sensitive sensors 21 and 22 have a low density on the leg side, as shown in FIG. 12 (b), the floor person H opens the leg portion and lies in the center on the floor surface 15a. In particular, when there is no deviation, it is possible to eliminate a problem that an unnecessary alarm is issued if the position of the bedded person H is shifted.
In addition, as shown in FIG. 12C, in the case of a light and small bedridden H such as a child, the detection sensitivity of the pressure sensors 21 and 22 is low, but the pressure sensors 21 and 22 on the lower limb side are low. Since the bed is disposed closer to the center, the bedridden H itself can be reliably detected. As a result, it is possible to accurately detect the presence of the floor, and even when a deviation occurs, it can be detected with high accuracy as described above.
[0054]
Here, it is particularly desirable that the pressure-sensitive sensors 21 and 22 in the above embodiments are piezoelectric sensors made of the above-described materials. However, the present invention is not limited to this pressure-sensitive sensor. For example, various electrical contacts such as a cable-type sensor that detects pressure when contacts are embedded in a cable and the contacts come into contact with each other by bending the cable. It is also possible to apply the pressure sensitive sensor.
[0055]
【The invention's effect】
As described above, according to the detection apparatus and the detection method for the bedridden person according to the present invention, the first detection means and the second detection means including the cable-shaped pressure sensor are installed at both ends of the bed surface. Arranged along the floor direction, the judgment means compares the output of the signals from the first detection means and the second detection means, and judges the lateral deviation of the position of the person on the floor. Therefore, it is possible to prevent the fall of the bedridden from the floor from the determination result.
In addition, since the cable-like pressure sensor is simply disposed on both sides of the bed surface, compared to a plurality of sensors composed of expensive piezoelectric elements arranged in a grid pattern on the floor surface, Cost increase can be suppressed as much as possible, and deterioration of sleeping comfort can be suppressed as much as possible.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a bed equipped with a bed detection device according to a first embodiment of the present invention.
FIG. 2 is a plan view of a pressure sensitive sheet constituting the detection device.
FIG. 3 is a plan view showing a pressure sensor and a protruding piece of a protruding sheet.
FIG. 4 is a cross-sectional view showing a pressure sensor and a protruding sheet.
FIG. 5 is an exploded perspective view of a pressure sensor disposed on a pressure sensitive sheet.
FIG. 6 is a block diagram illustrating a configuration and functions of a detection device.
FIG. 7 is a graph for explaining a method of determining a position shift by a determination unit;
FIG. 8 is a schematic plan view showing the position of a person on the floor.
FIG. 9 is an exploded perspective view of a pressure-sensitive sheet for explaining another structure of the pressure-sensitive sheet.
FIG. 10 is a schematic plan view of a pressure-sensitive sheet constituting a bedded person detecting apparatus according to a second embodiment of the present invention.
FIG. 11 is a schematic view of a bedded person showing a distribution of the load of the bedside person on the bedded surface.
FIG. 12 is a schematic plan view showing the position of the bedridden person on the bed surface.
[Explanation of symbols]
11 Protrusion sheet
13, 55, 61 Pressure sensitive sheet
15a Bed surface
17,53 Projection piece
21 Pressure sensor (first pressure sensor)
22 Pressure sensor (second pressure sensor)
23 Center electrode
25 Piezo element materials
27 Outside electrode
29 Jacket
31 1st signal processing part
33 Second signal processing unit
35 Amplifier circuit
37 Filter
39 Smoothing circuit
41 judging means
43 Notification means
51,52 sheets
100 beds
A, B output
H Bedridden

Claims (8)

A detection device for a bedridden that detects a deviation of the position of the bedridden on the floor,
A cable-like first sensation that is individually disposed along both sides of the bed surface in the width direction, and that detects an acceleration component due to the movement of the bed person and outputs a signal. A pressure sensor and a second pressure sensor;
And a determination means for comparing the output signals from the first pressure sensor and the second pressure sensor to determine a shift state of the bed person toward the bed surface side. Detection device for bedridden people. The detection of a bedridden according to claim 1, wherein the first pressure sensor and the second pressure sensor set the wiring density on the head side of the bedbed higher than other areas. apparatus. The first pressure sensor and the second pressure sensor are set so that the arrangement density on the lower limb side of the bedridden person is lower than other regions. Detection device for floor person. 3. The first pressure sensor and the second pressure sensor are each wired in a wavy shape on the floor surface, and the wiring density is changed according to an arrangement interval of the wavy waves. Or the detection apparatus of the bedridden of Claim 3. The protrusion piece is arrange | positioned at the upper side or the lower side of the said pressure sensor, and this protrusion piece has overlapped in the several places of the said pressure sensor, The any one of Claims 1-4 characterized by the above-mentioned. In bed detection device. The pressure-sensitive sensor and the protruding piece are each attached to a sheet, and the pressure-sensitive sensor and the protruding sheet to which the protruding piece is attached are overlapped with each other. 5. A detection apparatus for a bedridden according to 5. When the determination means determines that a deviation has occurred in the position on the floor surface of the bedridden person, and outputs a notification signal,
The informing person according to any one of claims 1 to 6, further comprising informing means for informing that a deviation has occurred in response to the informing signal output by the judging means. Detection device. A detection method for a bedridden that detects a shift in the position of the bedrock on the floor,
A cable-like first sensation that is individually disposed along both sides of the bed surface in the width direction, and that detects an acceleration component due to the movement of the bed person and outputs a signal. The ratio of the intensity of the output signal from the pressure sensor and the second pressure sensor is obtained, and when the ratio falls within a predetermined range, the position of the bed person on the floor surface is offset. A method for detecting a bedridden characterized in that it is determined.

Images