User detection system, sensor device included in user detection system, and bed provided with user detection system

Abstract

In the present invention, a user detection system can be additionally attached later to a bed not originally equipped with the user detection system, and then later removed.　The user detection system senses a state of a user on a bed and comprises: a plurality of sensor devices that sense the load of the user; and a monitoring control device that is electrically connected to the plurality of sensor devices and receives signals from the plurality of sensor devices so as to sense the state of the user. The user detection system is configured to be detachably attached to a bed not originally equipped with the system, and each sensor device is detachably attached so as to be suspended below the bottom of the bed. Each sensor device has a pressed part that is pressed upon by the load of the user, and the pressed part is inserted into a ventilation through-hole in the bottom.

Description

User detection system, sensor device included in user detection system, and bed equipped with user detection system

[0001] The present invention relates to a system for detecting a user's status, such as when the user gets out of bed or their position on the bed, in a bed having multiple movable sub-bottoms, a sensor device included in the system, and a bed equipped with the system.

[0002] Related technologies are disclosed in, for example, Patent Documents 1 to 4. The bed apparatus disclosed in Patent Document 1 uses three pressure sensor units arranged at both ends and the center in the width direction on the back board and three pressure sensor units arranged at both ends and the center in the width direction on the fixing board to determine whether the user's position on the bed is normal supine, at risk of falling, out of bed, in bed, or has fallen.

[0003] The user position detection device disclosed in Patent Document 2 has a number of bag-shaped cells arranged in the width and length directions of the air mattress, and calculates the user's position on the air mattress by detecting the difference in air pressure between adjacent bag-shaped cells.

[0004] The bed exit confirmation device disclosed in Patent Document 3 has strip-shaped sensors extending across the width of the bed in positions corresponding to the user's shoulders, waist, and feet, located in the gap between the mattress and a number of butterfly springs supporting the underside of the mattress. The strip-shaped sensors have tactile switches, and the outputs of these tactile sensors are used to detect the presence or absence of a person on the mattress and changes in their position.

[0005] The biometric information measuring pummel disclosed in Patent Document 4 is a panel placed on the surface of a bed, has an elastically bendable receiving plate portion, has a strain gauge attached to the receiving plate portion, and measures the user's biometric information using the output of the strain gauge corresponding to the vibration of the center of the receiving plate portion.

[0006] JP 2008-100039 A JP 2017-000318 A WO 2012 / 053599 A JP 2005-253957 A

[0007] The bed apparatus described in Patent Document 1 is presumed to be shipped with a user detection system as standard equipment for detecting the user's status, such as when the user gets out of bed or their position on the bed. Such beds are more expensive than beds that do not. However, the necessity of a user detection system varies depending on the user. Furthermore, even for the same user, the necessity of the system varies depending on factors such as health condition and care environment. Therefore, it would be more convenient if a user detection system could be retrofitted to a bed that does not already have one, and if it could be removed later.

[0008] In this case, it is preferable that the work of attaching and detaching the user detection system to the bed be as simple and quick as possible.

[0009] According to the above-mentioned conventional technology, the user detection system has a sensor device that responds to the weight or body movement of the user, and the sensor device is provided on the upper surface of the bottom that supports the mattress. However, if the sensor device protrudes above the upper surface of the bottom due to its thickness, the protruding sensor device may deteriorate the user's sleeping comfort.

[0010] Most beds equipped with user detection systems are nursing or medical beds. Many of these types of beds are equipped with multiple movable sub-bottoms that can be tilted to change the user's posture between different positions, such as a lying position, an upright position, and a leg-up position. It is also desirable for the user detection system to be able to flexibly adapt to such variations in the posture of the bottom, i.e., the user's posture.

[0011] Users have different physiques, and there are also variations in the length and width of bed bottoms. It is desirable for the user detection system to be able to adapt to variations in user physiques and bed bottom sizes.

[0012] SUMMARY OF THE INVENTION It is therefore an object of the present invention to improve the convenience or adaptability of user detection systems for beds.

[0013] According to one embodiment of the present disclosure, a user detection system for a bed includes a plurality of sensor devices that detect a user's load and emit signals corresponding to the load, and a monitoring control device that receives the signals from the plurality of sensor devices and detects the user's condition. The user detection system is configured to be removably attached to the bed after installation. The plurality of sensor devices are removably attached to a plurality of different positions on the bed bottom in a plan view so as to be suspended from the bed bottom.

[0014] According to one embodiment, the bottom has a plurality of through holes that penetrate the bottom in its thickness direction and can function as air vents. Each of the sensor devices has a pressure-receiving portion that is pressed by the weight of the user. When each of the sensor devices is attached to the bottom, the pressure-receiving portion is inserted into the through hole from below, and each of the sensor devices is configured to sense the weight of the user by the pressure-receiving portion in the through hole being pressed by a mattress placed on the bottom.

[0015] According to one embodiment, when each sensor device is attached to the bottom, the upper surface of the pressed portion is positioned at the same height as or lower than the upper surface of the bottom so that the bottom surface of the mattress enters the through hole due to the user's weight, causing the mattress to press against the upper surface of the pressed portion.

[0016] According to one embodiment, when the bottom has a greater number of through holes than the number of the sensor devices, the mounting position of each sensor device on the bottom can be changed by changing the through hole into which the pressing portion of each sensor device is inserted.

[0017] 4. The user detection system according to claim 2, wherein the bottom has a mesh structure, and a plurality of meshes of the bottom of the mesh structure are used as the plurality of through-holes.

[0018] According to one embodiment, the bottom is a flat bottom made of metal or resin, and the flat bottom has a plurality of ventilation holes, which are used as the plurality of through holes.

[0019] According to one embodiment, a fixing device is provided for removably attaching the sensor device to the bottom, and the fixing device is configured so that an operator can fix the sensor device to the bottom using a screw or with a single touch.

[0020] According to one embodiment, the fixing device has a snap-fit ​​connection structure that enables an operator to fix the sensor device to the bottom with one touch.

[0021] According to one embodiment, the upper surface of the fixture is located at the same height as or below the upper surface of the bottom.

[0022] According to one embodiment, the user detection system includes eight of the eight sensor devices, and two of the eight sensor devices are attached to each of four regions of the bottom that receive loads from four parts of the user: the back of the upper body, the lower back including the portion from the lower waist to the buttocks, the upper parts of the lower legs including the portion from the thighs to the knees, and / or the lower parts of the lower legs including the portion from the lower legs to the feet, when the user is lying supine on the bed with their body stretched straight and their height aligned along the longitudinal direction of the bed. The two sensor devices attached to each of the regions of the bottom are respectively arranged in a first half region from the center of the width direction of each of the regions of the bottom to one end in the width direction and in a second half region from the center of the width direction of each of the regions to the other end in the width direction.

[0023] According to one embodiment, the bottom has four element bottoms: a back bottom that supports the back of the user, a waist bottom that supports the waist of the user, a knee bottom that supports the upper parts of the user's lower legs, and a foot bottom that supports the lower parts of the user's lower legs, and the angles of the back bottom, knee bottom, and foot bottom are variable with respect to the horizontal. The user detection system includes eight sensor devices, and two sensor devices selected from the eight sensor devices are attached to each of the four element bottoms. The two sensor devices attached to each element bottom are arranged in a first half region from the center in the width direction of each element bottom to one end in the width direction, and in a second half region from the center in the width direction of each element bottom to the other end in the width direction, respectively.

[0024] According to one embodiment, each of the sensor devices includes a support and a lever cover disposed above the support. The lever cover has a fulcrum supported by the support and an extension extending in one direction from the fulcrum in a plan view. The extension is rotatable in the vertical direction around the fulcrum and is elastically lifted from the support. The lever cover has the pressed portion on an upper portion of the extension. Each of the sensor devices is disposed so that the one extending direction of the extension portion is aligned with the width direction of the bottom and so that the pressed portion is located closer to the center of the width direction of the bottom than the fulcrum in a plan view.

[0025] According to one embodiment, each of the sensor devices includes a cushion disposed below the extension portion of the lever cover and a pressure sensor disposed above the support body and below the cushion. When the pressure-receiving portion is pressed downward by the user's weight, the lever cover descends and applies pressure to the pressure sensor via the cushion member, causing the pressure sensor to output a signal corresponding to the pressure.

[0026] According to one embodiment, the bottom has two or more through holes arranged at different positions in the width direction of the bottom. Each of the sensor devices has two or more pressurized portions arranged at upper portions of the extension portion at different positions in the one direction in which the extension portion extends in a plan view. When each of the sensor devices is attached to the bottom, the two or more pressurized portions are inserted into the two or more through holes arranged in the width direction of the bottom.

[0027] According to one embodiment, the lever cover of each of the sensor devices covers the entire upper area of ​​the support from above.

[0028] According to one embodiment, the monitoring and control device is disposed below the waist bottom.

[0029] According to one embodiment, the bed includes a bottom drive system that drives one or more of the bottom elements. The monitoring control device is connected to the plurality of sensor devices and the bottom drive system, and detects the state of the user based on the signals from the plurality of sensor devices and the signals related to the drive of the bottom elements from the bottom drive system.

[0030] According to one embodiment, each of the plurality of sensor devices includes a pressure-receiving portion that is pressed by the user's weight and a pressure sensor that detects the user's weight via the pressure-receiving portion. The pressure-receiving portion is inserted into a through-hole that penetrates the bottom in the thickness direction. Each of the sensor devices is configured to detect the user's weight when the pressure-receiving portion is pressed.

[0031] According to one embodiment, the bed has a mattress placed on the bottom, and the mattress expands into the through-hole due to the weight of the user, thereby pressing the pressed portion.

[0032] A perspective view of a bed equipped with the user detection system of this embodiment. Plan views (A), (B), and (C) of the bed in Figure 1. A diagram explaining the movable state of the bed bottom. A schematic diagram showing the arrangement of each part of the user detection system. A diagram showing the attachment state of the sensor device to the element bottom. A perspective view of the sensor device. A cross-sectional view A-A in Figure 6. A diagram explaining the arrangement of the cushion material and pressure sensor of the sensor device. A diagram showing the state in which the sensor device is attached to the mesh bottom. A cross-sectional view of the sensor device attached to the mesh bottom along a second direction. A diagram showing an example of the control flow of the monitoring control device 6. A diagram showing one aspect of a modified fixing device. A diagram showing a first modified example of the element bottom. A diagram showing a second modified example of the element bottom. A diagram showing a third modified example of the element bottom. A diagram showing a fourth modified example of the element bottom.

[0033] The present embodiment will be described below with reference to the drawings. A bed 1 according to the present embodiment shown in Figures 1 and 2 has a substantially rectangular shape in plan view.

[0034] In the following description, the term "length direction" means the direction along the long sides of the rectangle of bed 1, "width direction" means the direction along the short sides of bed 1, and "height direction" means the vertical direction when bed 1 is placed on a horizontal floor. Furthermore, "head direction" means the direction from the feet to the head as seen from the user when lying on their back on bed 1, "head side" means the side closer to the user's head, "foot direction" means the direction from the user's head to their feet, "foot side" means the side closer to the user's feet, and "front," "rear," "left," and "right" mean the directions or sides of front, rear, left, and right as seen from the user.

[0035] The bed 1 according to this embodiment includes a base frame 11, a center frame 12, a head frame 13, and a foot frame 14. The base frame 11 is substantially rectangular in plan view, and is placed on the installation floor via casters 15 (or fixed feet, not shown) provided at its four corners.

[0036] A center frame 12, a head frame 13, and a foot frame 14 are mounted on a base frame 11. The head frame 13 is disposed on the head side of the center frame 12 and the two are joined together, and the foot frame 14 is disposed on the foot side of the center frame 12 and the two are joined together. In this way, the center frame 12, the head frame 13, and the foot frame 14 are mutually joined to form a single lifting frame 12, 13, 14 that is substantially rectangular in plan view as a whole.

[0037] The lifting frames 12 , 13 , 14 (for example, the center frame 12 ) are connected to a lifting mechanism 16 provided on the base frame 11 , and can be raised and lowered in the height direction by the lifting mechanism 16 .

[0038] The bottom 2 is placed on the lifting frames 12, 13, and 14. The bottom 2 is a substantially rectangular plate in plan view and supports a mattress (not shown) placed thereon. The bottom 2 has a plurality of substantially rectangular, flat, plate-like element bottoms arranged at different positions in the length direction. These element bottoms are, for example, a back bottom 21, a waist bottom 23, a knee bottom 25, and a foot bottom 27, in that order from the head side to the foot side.

[0039] FIG. 3 is a diagram illustrating the movable state of each bottom element. The back bottom 21 is for supporting the user's upper body, e.g., the back. The back bottom 21 includes, for example, an upper back bottom 21A and a lower back bottom 21B disposed closer to the feet than the upper back bottom 21A. The upper back bottom 21A and the lower back bottom 21B are rotatably linked to each other via a back bending hinge 21C at the foot end of the upper back bottom 21A and the head end of the lower back bottom 21B. The back bottom 21 (including the lower back bottom 21B) is rotatably linked to the lifting frames 12, 13, and 14 at its foot end via a back-raising hinge 24.

[0040] The upper back bottom 21A is intended to support a relatively high portion of the user's upper body (e.g., from the head to the shoulder blades), while the lower back bottom 21B is intended to support a relatively low portion of the user's upper body (e.g., from the shoulder blades to the upper waist).

[0041] The back bottom 21 is coupled to a back-raising mechanism (not shown) provided on the lifting frames 12, 13, and 14, for example, and can be rotated as a whole around the back-raising hinge 24 by the back-raising mechanism, allowing the chair to assume various positions from a horizontal position to a position tilted forward by a predetermined angle. This allows the user's upper body to be raised or reclined. Figures 3(A) and (B) show examples of how the angle of the back bottom 21 changes as a result of rotation.

[0042] The upper back bottom part 21A and the lower back bottom part 21B of the back bottom 21 are connected to the back-raising mechanism (or a separate back-bending mechanism), and this mechanism allows the upper back bottom part 21A to rotate relative to the lower back bottom part 21B around the back-bending hinge 21C (rotation state not shown), allowing the upper back bottom part 21A to assume various positions from a flush position to a position bent forward by a predetermined angle. This allows the position of the user's upper body (spine) to be adjusted between a straight position and a position bent forward to some extent.

[0043] The longitudinal position of the back bending hinge 21C that links the upper back bottom 21A and the lower back bottom 21B is variable within a predetermined distance range and can be set to any position among a plurality of different positions (not shown). This allows the position of the back bending hinge 21C, i.e., the position at which the user bends their back, to be adjusted to suit the user's physique and physical characteristics.

[0044] The waist bottom 23 is for supporting the user's hips, for example, the area from the lower back to the buttocks (lumbar region). The waist bottom 23 is fixed horizontally to the lifting frames 12, 13, and 14, for example.

[0045] The knee bottom 25 is intended to support the user's upper leg, for example, from the thigh to the vicinity of the knee. The knee bottom 25 is rotatably linked at its head end to the lifting frames 12, 13, and 14 via a knee-raising hinge 28. The knee bottom 25 is connected to a knee-raising mechanism (not shown) provided on the lifting frames 12, 13, and 14, for example, and can be rotated around the knee-raising hinge 28 by the knee-raising mechanism to assume various positions from a horizontal position to a position tilted forward by a predetermined angle. This allows the user's knee to bend the knee joint or to straighten the knee by raising the knee.

[0046] The foot bottom 27 is intended to support the portion of the user from near the knee to the foot (lower leg). The knee bottom 25 and the foot bottom 27 are rotatably linked to each other via a knee bending hinge 26 at the foot end of the knee bottom 25 and the head end of the foot bottom 27. The foot end of the foot bottom 27 is placed on the lifting frames 12, 13, 14 in a state where it can slide in the longitudinal direction. When the knee bottom 25 rotates around the knee lifting hinge 28 by the knee lifting mechanism, the foot bottom 27 also rotates around the knee bending hinge 26. Note that Figures 3(A) and (B) show examples of changes in the angle between the knee bottom 25 and the foot bottom 27 due to rotation.

[0047] Alternatively, the foot bottom 27 may be coupled to a foot raising mechanism provided on the lifting frame 12, 13, 14, which allows the foot bottom 27 to rotate about the knee bending hinge 26 to adjust the height of the user's feet (not shown).

[0048] The position of the knee bending hinge 26 in the longitudinal direction is variable within a predetermined distance range, and can be set to any of a plurality of different positions (not shown), for example. This allows the position of the knee bending hinge 26, i.e., the position at which the user's knee is bent, to be adjusted to suit the user's physique, physical characteristics, etc.

[0049] The back bottom 21, the waist bottom 23, the knee bottom 25, and the foot bottom 27 may each be configured so that their length and / or width dimensions are variable (the specific configuration for variable dimensions is not shown, but known technology can be used).

[0050] The position of each element bottom can be controlled by the user or caregiver using a control panel provided on the bed 1 or a remote controller (not shown).

[0051] Each of the bottom elements, such as the back bottom 21, the waist bottom 23, the knee bottom 25, and the leg bottom 27, has, for example, a mesh structure. A mesh bottom element generally includes a relatively thick, highly rigid outer frame 31 that is shaped approximately rectangular in plan view, a plurality of elongated vertical wires 33A that are stretched lengthwise with spaces between them inside the outer frame 31, and a plurality of elongated horizontal wires 33B that are stretched widthwise with spaces between them inside the outer frame 31. These vertical wires 33A and horizontal wires 33B intersect to form a mesh structure. Such a mesh bottom element has a large number of meshes (i.e., through-holes 35 that penetrate the bottom in the thickness direction from the top surface to the bottom surface) arranged in a matrix in the lengthwise and widthwise directions.

[0052] The bed 1 is equipped with a user detection system 4 including a plurality of sensor devices 5 .

[0053] The user detection system 4 for the bed 1 according to this embodiment will now be described. Fig. 4 is a schematic diagram showing an example of the arrangement of each part of the user detection system 4. Fig. 5 is a diagram showing an example of the attachment state of the sensor device 5 to each element bottom (representatively, the back bottom 21 is shown).

[0054] The bed 1 according to this embodiment does not need to be equipped with the user detection system 4 when it is shipped. After shipping, the user detection system 4 can be additionally and detachably attached to the bed 1 as an optional item. Furthermore, once the user detection system 4 has been attached to the bed 1, it can also be removed from the bed 1. The task of attaching or detaching the user detection system 4 to or from the bed 1 is simple, requiring only a worker to tighten or loosen a fixing screw with a screwdriver, or to attach or detach with a single touch, and can be completed in a short time.

[0055] The user detection system 4 includes a plurality of sensor devices 5 (eight in the illustrated example) and at least one monitoring control device 6 electrically connected to the sensor devices 5 .

[0056] The monitoring and control device 6 may be electrically connected to a nurse call system 9. The nurse call system 9 will be described later.

[0057] The monitoring control device 6 may further be electrically connected to a bottom drive system (in this embodiment, for example, the bottom drive control device 7) that includes several mechanisms for changing the posture of the bottom 2 of the bed 1, such as the above-mentioned back-raising mechanism, back-bending mechanism, and knee-raising mechanism, and a bottom drive control device 7 that drives and controls them.

[0058] The eight sensor devices 5 basically have the same configuration, but may have different configurations. Each sensor device 5 senses the load applied by the user to the upper surface of each bottom element through a mattress (not shown) and outputs an electrical signal indicating a value corresponding to that load. The specific configuration will be described later.

[0059] The following description will be given with reference to Figure 4. The eight sensor devices 5 are paired in pairs of two sensor devices 5 to form four pairs of sensor devices 5. These four pairs of sensor devices 5 are attached to the bottom 2 in the following arrangement in a plan view: When the user is lying on their back on the bed 1 with their body stretched out straight and their height aligned with the longitudinal direction of the bed 1, the four pairs of sensor devices 5 are attached to four areas of the bottom 2 that receive loads from four parts of the user's back of the upper body, the lower back including the region from the lower waist to the buttocks, the upper legs including the region from the thighs to the knees, and / or the lower legs including the region from the lower legs to the feet.

[0060] The pair of sensor devices 5 attached to each of the above-mentioned regions of the bottom 2 are respectively arranged in the right half region from the center in the width direction to one end in the width direction of each of the above-mentioned regions of the bottom 2, and in the left half region from the center in the width direction to the other end in the width direction of each of the regions. A gap is provided between the pair of sensor devices 5, and the center in the width direction of the bottom 2 is located within this gap. No sensor device 5 is arranged in this gap.

[0061] An example of such four pairs of sensor devices 5 is shown in FIG. 4. That is, the four pairs of sensor devices 5 are attached to four element bottoms, namely, the back bottom 21, the waist bottom 23, the knee bottom 25, and the foot bottom 27. For example, a first pair of sensor devices 5(a), 5(a) are attached to the back bottom 21, a second pair of sensor devices 5(b), 5(b) are attached to the waist bottom 23, a third pair of sensor devices 5(c), 5(c) are attached to the knee bottom 25, and a fourth pair of sensor devices 5(d), 5(d) are attached to the foot bottom 27. Here, it is desirable that the first pair of sensor devices 5(a), 5(a) be attached to, for example, the lower back bottom 21B of the upper back bottom 21A and the lower back bottom 21B of the back bottom 21. This is because the lower back bottom 21B often receives a greater load from the user than the upper back bottom 21A.

[0062] By arranging four pairs of sensor devices 5 (i.e., a total of eight sensor devices 5) in the bottom 2 in this manner, it is possible to appropriately detect the user's state, such as their position and posture, on the bed 1. In other words, without using too many sensor devices 5, with a moderate number of sensor devices 5, eight, which is neither too many nor too few, it is possible to determine with sufficient resolution for practical use whether the user's state is normal, requires caution, or is in danger. Furthermore, by arranging four pairs of sensor devices 5 (i.e., a total of eight sensor devices 5) in the bottom 2 as described above, it is possible to determine whether the user's state is normal, requires caution, or is in danger even when the bottom 2 is in a bent position that is not horizontal due to bottom movement such as lifting the back or knees.

[0063] The sensor devices 5 of each pair may be disposed in positions that are basically symmetrical with respect to the center line CL of each bottom element in the width direction in a plan view. For example, one sensor device 5(a) of the first pair may be disposed in a range from a position shifted a predetermined distance to the left from the center line CL of the back bottom 21 in the width direction to the left end of the back bottom 21, and the other sensor device 5(a) may be disposed in a position range that is symmetrical to the right of the sensor device 5(a).

[0064] Similarly, the other three pairs of sensor devices 5 may be arranged at positions symmetrical to the left and right of the center line CL in the width direction of each bottom element. Depending on the user's physique, behavioral patterns, and other environmental conditions, the sensor devices 5 of each pair may be arranged at positions slightly shifted in the length direction or width direction from the center line CL in the width direction of each bottom element.

[0065] The following description will be made using FIG. 5 . For example, as shown in FIGS. 5A and 5C , the distance (spacing) between the first pair of sensor devices 5(a), 5(a) in the width direction of the bottom 2 can be adjusted. That is, the distance from the center line CL to each of the sensor devices 5(a), 5(a) can be adjusted. Also, as shown in FIGS. 5A and 5B , the longitudinal positions of the first pair of sensor devices 5(a), 5(a) on the back bottom 21 can also be adjusted. That is, the placement of each sensor device 5(a), 5(a) on each bottom element can be appropriately adjusted as needed, depending on the patient's physique, condition (e.g., medical condition), etc. Note that, for the sake of simplicity, only the first pair of sensor devices 5(a), 5(a) has been described above. However, it goes without saying that the same applies to all of the sensor devices 5 included in the user detection system 4.

[0066] Returning to FIG. 4 , the monitoring and control device 6 is placed in the empty space below the bottom 2. For example, the monitoring and control device 6 can be placed in the empty space below the waist bottom 23. This is because an empty space suitable for storage is easily formed below the waist bottom 23, and the waist bottom 23 is fixed and does not rotate, making it easy to store. This placement also allows the monitoring and control device 6 and all (eight in the illustrated example) sensor devices 5 to be placed at an appropriate distance. For example, if the monitoring and control device 6 and each sensor device 5 are connected by wire (the wires are shown by dotted lines in the illustrated example), this makes it easy to organize the wiring. Furthermore, the length of the wires does not need to be extremely long or short; it is sufficient to set them to approximately the same length. The monitoring and control device 6 may also be placed in another empty space below the bottom 2, or in another location, such as next to the bed 1.

[0067] <Structure of Sensor Device> Next, the structure of the sensor device 5 will be described with reference to the drawings. Fig. 6 is a perspective view of the sensor device 5. Fig. 7 is a cross-sectional view taken along line A-A in Fig. 6, and Fig. 8 is a diagram illustrating the arrangement of the cushioning material 72 and pressure sensor of the sensor device 5. Fig. 9 is a diagram illustrating the state in which the sensor device 5 is attached to a mesh-structured bottom element (waist bottom 23). Fig. 10 is a cross-sectional view of the sensor device 5 attached to a mesh-structured bottom 2 taken along the second direction.

[0068] The sensor device 5 has, for example, an elongated, substantially rectangular parallelepiped shape as a whole. In the following description, the term "first direction" refers to the longitudinal direction of the sensor device 5 in a plan view, and the term "second direction" refers to the lateral direction of the sensor device 5 in a plan view.

[0069] The sensor device 5 is attached to one of the element bottoms of the bed 1 in an orientation in which its first direction coincides with the width direction of the bed 1.

[0070] The sensor device 5 includes a support body 51 and a lever cover 52. Both the support body 51 and the lever cover 52 are, for example, elongated, approximately rectangular boxes. The support body 51 is, for example, a box having a bottom wall 51a and side walls 51b and an open top portion 51c with no top wall. The lever cover 52 is, for example, a box having a top wall 52a and side walls 52b and an open bottom portion 52c with no bottom wall. The size of the lever cover 52 is larger than the size of the support body 51 in both the first direction and the second direction. The portion of the support body 51 including the open top portion 51c is completely housed within the opening in the bottom portion 52c of the lever cover 52, and the open top portion 51c of the support body 51 and the upper part of the surrounding side wall 51b are covered from the outside by the top wall 52a and the surrounding side wall 52b of the lever cover 52.

[0071] The support 51 has four arms 53 that extend outward in the second direction from two locations on both sides near one end in the first direction and two locations on both sides near the other end by a certain distance. These four arms 53 function as part of fixing devices for attaching the sensor device 5 to the element bottom.

[0072] That is, each of the four arms 53 has a female screw hole formed downward from its top surface. Two fixing plates 54 are further provided as other parts of the fixture. One fixing plate 54 is for connecting to the two arms 53 extending from both side surfaces near the one end, and has through holes 54a in two locations corresponding to the female screw holes (not shown) of the two arms 53. The other fixing plate 54 is for connecting to the two arms 53 extending from both side surfaces near the other end, and has through holes 54a in two locations corresponding to the female screw holes of the two arms 53.

[0073] The lever cover 52 of the sensor device 5 has protrusions 56 as pressed portions that are pressed by the user's weight. Specifically, for example, the lever cover 52 has, on the upper part of its top wall 52a, a plurality of mesa-shaped (i.e., plateau-shaped with a flat upper surface) protrusions (pressed portions) 56 aligned in a row in the first direction. Each protrusion 56 is square or rectangular in plan view, and this shape is selected so that it can be inserted from below into each mesh (through-hole 35) of the element bottom and accommodated therein. The upper part of the top wall 52a of the lever cover 52 has recessed grooves 57 adjacent to each protrusion 56. The width and depth of each groove 57 are selected so that it can accommodate the vertical wires 33A or horizontal wires 33B that define each mesh of the element bottom.

[0074] As a result, the multiple mesa-shaped protrusions 56 aligned in the first direction of the lever cover 52 of the sensor device 5 are housed inside the multiple meshes (through holes 35) aligned in the width direction of the bottom element. The upper surfaces of these protrusions (pressure-receiving portions) 56 are located at the same height as or lower than the upper surface of the bottom element, i.e., the upper surfaces of the vertical wires 33A arranged above the horizontal wires 33B in this embodiment. For example, it is desirable that the height of the upper surfaces of the protrusions 56 be the same as or slightly lower (e.g., a few tenths of a millimeter) than the upper surfaces of the vertical wires 33A. Therefore, the upper surface of the sensor device 5 does not protrude higher than the upper surface of the bottom element. Therefore, the sensor device 5 does not affect the user's sleeping comfort. On the other hand, when the user's weight is applied to a mattress (not shown) on the bottom, the mattress penetrates the mesh (through holes 35) of the bottom element and bulges downward, pressing downward on the convex portion 56 of the lever cover 52, causing the load due to the user's weight to be applied from the mattress to the lever cover 52 of the sensor device 5. The sensor device 5 can detect this load. It is also desirable that the top surface of the fixing tool does not protrude above the top surface of the bottom. Specifically, it is desirable that the top surface of the fixing plate 54 be positioned at the same level as or lower than the top surface of the bottom element. This prevents the method of mounting the sensor device 5 from adversely affecting the user's sleeping comfort.

[0075] The internal structure of the sensor device 5 for detecting the load will be described below.

[0076] For example, as shown in FIG. 7 , the sensor device 5 has a pressure sensor 71 , a cushion material 72 , and an elastic member between a support body 51 and a lever cover 52 .

[0077] The lever cover 52 has a support rod 58 that protrudes downward from the underside of its top wall 52a at a location near one end in the first direction. The lower end 58a of the support rod 58 abuts against a location on the bottom wall 51a of the support body 51. An elastic member, such as a coil spring 73, is inserted between a location near the other end in the first direction of the top wall 52a of the lever cover 52 and a location on the bottom wall 51a of the support body 51 located directly below the location. The coil spring 73 lifts the lever cover 52 upward and elastically supports it. As a result, in a plan view of the lever cover 52, an extension 59 that extends from the lower end 58a of the support rod 58 toward the other end in the first direction does not directly contact the support body 51 but floats above the support body 51. Therefore, the lever cover 52 is supported on the support body 51 in a state in which it can swing up and down like a seesaw, with the lower end portion 58a of the support rod 58 as a fulcrum.

[0078] A pressure sensor 71 is installed on the upper surface of the bottom wall 51a of the support body 51, at a location between the fulcrum in the first direction when viewed in a plane (lower end portion 58a in the illustrated example, the same below) and the elastic member (coil spring 73 in the illustrated example, the same below).

[0079] 8, a cushioning material 72 is inserted between the upper surface of the pressure sensor 71 and the lower surface of the top wall 52a of the lever cover 52. For example, the cushioning material 72 may be fixed to the lower side of the top wall 52a of the lever cover 52 with an adhesive or by other methods, or may be fixed to the upper side of the pressure sensor 71 on the support body 51 side, or may be configured not to be fixed to any member and to be inserted between the upper surface of the pressure sensor 71 and the lower surface of the top wall 52a of the lever cover 52 by the user.

[0080] The pressure sensor 71 is, for example, a thin, flat plate attached to the bottom wall 51a of the support body 51, and converts pressure applied to its upper surface into an electrical signal having a value corresponding to the pressure. The output signal of the pressure sensor 71 is input to the monitoring and control device 6.

[0081] The cushion material 72 is positioned between the lever cover 52 and the pressure sensor 71, and absorbs the mechanical shock that the lever cover 52 applies to the pressure sensor 71. The cushion material 72 is made of a soft elastic material such as silicone rubber.

[0082] When a downward load is applied from above to any of the protrusions 56 of the extension 59 of the lever cover 52 of the sensor device 5 configured in this manner, the extension 59 of the lever cover 52 rotates about the fulcrum and descends, pressing against the pressure sensor 71 via the cushion material 72. The pressure sensor 71 provides the monitoring and control device 6 with an electrical signal having a value corresponding to the pressing force. When the pressure applied to the pressure sensor 71 is released, the lever cover 52 returns to its original position due to the action of an elastic member (e.g., a coil spring 73), and the output signal from the pressure sensor 71 indicates zero pressure. Note that the elastic member is not shown in FIG. 8.

[0083] The sensor device 5 detects the load applied by the user anywhere in the widthwise range of the bed 1 across almost the entire length in the first direction (i.e., on any of the multiple protrusions 56). Despite the wide detectable widthwise range, each sensor device 5 only requires one pressure sensor 71, which reduces costs.

[0084] The sensor device 5 is attached to the bottom 2 in such a position that the point of action of the lever cover 52 (the part that presses the pressure sensor 71) is located near the center of the width of the element bottom (i.e., close to the center line CL), and the fulcrum of the lever cover 52 is located near the right or left end of the bottom 2 (i.e., away from the center line CL).

[0085] By attaching the sensor device 5 to the bottom 2 in this position, the state of the user on the bottom 2 can be detected more reliably than when the sensor device 5 is attached in the opposite position. This is because the user is often positioned near the center of the bottom 2. Therefore, when the sensor device 5 is attached in the above position, the load from the user is often applied to a location on the lever cover 52 that is relatively far from the fulcrum, that is, a location that is closer to the center of the bottom 2. The movement stroke of the lever cover 52 required to activate the pressure sensor 71 is relatively long at a location relatively far from the fulcrum, and therefore the accuracy of load detection is also relatively good.

[0086] The monitoring control device 6 receives output signals from the eight sensor devices 5 and an output signal from the bottom drive control device 7 and estimates the state of the user on the bed 1. The user's state to be determined includes, for example, whether the user is lying on their back on the bed 1 or sitting up, whether the user is sitting on the edge of the bottom 2 in the width direction (edge ​​sitting position), whether the user is sleeping near the edge of the bed 1 in the width direction (whether there is a risk of falling), whether the user has stood up and left the bed 1 (whether the user has left the bed), whether the user has been out of bed for a long period of time, etc.

[0087] Furthermore, it may be possible to determine whether the upper body of the user is leaning to the right, left, or forward when the back bottom 21 is upright, or whether the user's buttocks are sliding forward beyond the waist bottom 23 while the back bottom 21 is being moved from a lying position to an upright position. The variations in the user's state that are determined may be other than those described above, or may be more or less than those described above.

[0088] Alternatively, the monitoring control device 6 may not be connected to a bottom drive system such as the bottom drive control device 7, and may not need to make decisions that take into account the angle or movement of the bottom 2.

[0089] The monitoring and control device 6 sends a signal according to the estimated result of the user's condition to the nurse call system 9 via wired or wireless communication, thereby notifying the nurse or caregiver of information useful for user care (for example, whether the user is lying on their back normally on the bed 1, whether there is a risk of them falling off the bed 1, whether they are on the bed or not, whether their body is leaning abnormally when sitting with their upper body upright, etc.).

[0090] The nurse call system 9 includes, for example, a handset 91 installed near the bed 1 and a base unit 92 installed at a nurse's station or the like, but it may also be connected to or include a mobile communication terminal 90 carried by a nurse or caregiver, and there are many variations in the specific configuration. In the illustrated example, the monitoring and control device 6 is connected to the handset 91 of the nurse call system 9, and a signal from the monitoring and control device 6 is sent to the base unit 92 via the handset 91.

[0091] 11 shows an example of the control flow of the monitoring control device 6. The following explains this. The monitoring control device 6 receives signals output from the eight sensor devices 5, and, based on the received signals, determines the distribution of the user's load on the bottoms 2 (for example, which sensor devices 5, i.e., which positions on which bottom elements the user's load is being applied to, or the magnitude of pressure being applied to each sensor device 5, etc.) (S1).

[0092] The monitoring control device 6 also inputs the signal output from the bottom drive control device 7, and based on the input signal, grasps the posture of the bottom 2 (for example, various postures determined by the combination of the inclinations of multiple bottom elements, and the transition from one posture to another, etc.) (S2).

[0093] Next, the monitoring control device 6 inferentially determines whether the user is currently in the state of being on the bed 1 based on the grasped load distribution and the posture of the bottom 2 (S3).

[0094] Next, based on the determination result of S3, the monitor control device 6 transmits predetermined information or signals to the nurse call system 9 or the mobile communication terminal 90 as necessary (S4).

[0095] The monitoring and control device 6 repeats the above steps (S1 to S4).

[0096] <Attaching the Sensor Device to the Bed> When attaching the sensor device 5 to the element bottom, the following procedure can be performed.

[0097] An operator places the sensor device 5 below the bottom element, and the upper surfaces of the four arms 53 of the sensor device 5 abut against the lower surfaces of the two horizontal wires 33B of one bottom element. Two fixing plates 54 are placed above the bottom element, and the two fixing plates 54 abut against the upper surfaces of the two horizontal wires 33B. Four fixing screws (not shown) are then inserted from above into the four through holes 54a of the two fixing plates 54, and the fixing screws are inserted into the female threaded holes (not shown) of the four arms 53. The operator then tightens the fixing screws with a screwdriver. As a result, the two horizontal wires 33B of the bottom element are firmly sandwiched between the two fixing plates 54 and the four arms 53, and the sensor device 5 is firmly fixed to the bottom element in a suspended state.

[0098] This installation work can be easily performed by a worker using only a screwdriver, and can be completed in a short time.

[0099] The thickness of the fixing plate 54 is preferably selected so that the upper surface of the fixing plate 54 does not protrude above the upper surface of the element bottom (that is, so that it is positioned at the same level as or slightly below the upper surface of the element bottom).

[0100] <Modifications of Sensor Device and Fixing Device> Modifications of the fixing device will be described. FIG. 12 is a diagram showing one embodiment of a modification of the fixing device. To further simplify the fixing operation, the fixing device may employ, for example, a snap-fit ​​connection structure as follows. Here, a snap-fit ​​connection structure refers to a connection structure that utilizes elastic members, in which connectable portions of the structure are separated and then a person pushes or pulls a certain point of the structure in one direction to complete the connection of the connectable portions. An example of a snap-fit ​​connection structure is a structure, as described below, in which two members approach each other in one direction, causing at least one member to elastically deform and engage with the other member, and after engagement, the deformed member elastically returns to its original shape to maintain the engagement.

[0101] In this example, the fixing device has a fixing plate 154 with two locking protrusions 155 extending downward from its underside, for example, near both ends. The locking protrusions 155 have spring properties and will bend when subjected to a bending force, and will return to their original straight shape when the force is released. The tip 155a of the locking protrusions 155 has a tapered shape with a jaw, like a harpoon, for example. The outer surface of the jaw of the tip 155a of the locking protrusions 155 has an inclined surface 155b that is inclined in the direction in which the locking protrusions 155 extend. A locking hole 153a is provided near the tip of each arm 153, penetrating vertically. Each locking hole 153a has a shape and size that allows the tip 155a of the locking protrusions 155 to be inserted therethrough.

[0102] The distance between the two locking projections 155 and the distance between the two locking holes 153a are appropriately selected, so that the fixing plate 154 can be engaged with the arm 153 as follows.

[0103] That is, when the worker places the fixed plate 154 directly above the two arms 153 and then lowers the fixed plate 154 toward the arms 153, the tip ends 155a of the two locking protrusions 155 of the fixed plate 154 enter the two locking holes 153a of the two arms 153, and the inclined surfaces 155b of the tip ends 155a of the two locking protrusions 155 each come into contact with the inner surfaces of the two locking holes 153a.

[0104] When the operator then further lowers the fixing plate 154, the two locking protrusions 155 bend due to their spring properties, and the tip ends 155a of each of them pass through the two locking holes 153a. When the tip ends 155a of the two locking protrusions 155 have completely passed through the two locking holes 153a, the locking protrusions 155 return to their original straight shape due to their spring properties, and as a result, the tip ends 155a of the locking protrusions 155 engage with the locking holes 153a.

[0105] By adopting such a snap-fit ​​connection structure that can fix the fixing plate 154 to the arm 153 with one touch, the work of attaching the sensor device 5 to the element bottom can be done very easily and in a short time. Note that the arrangement of the locking protrusion 155 and the locking hole 153a may be reversed from that described above, i.e., the locking protrusion 155 may be provided on the arm 153 and the locking hole may be provided on the fixing plate 154.

[0106] With the sensor device 5 attached to the bottom of the bottom 2 in this manner, even if water gets on the sensor device 5 from above the bottom 2, for example, when a drink is spilled on the bed 1, when the user is incontinent, or when wiping the bed, water will hardly get inside the sensor device 5. This is because, as described above, the lever cover 52 covers the top and periphery of the support body 51 from the outside.

[0107] All or part of the element bottom may have a structure different from the mesh described above. For example, it may be a flat plate type structure made of synthetic resin or metal. A flat plate type element bottom will be described below.

[0108] 13 is a diagram showing a first modified example of bottom elements. Each of the bottom elements, such as the back bottom, waist bottom, knee bottom, and foot bottom, in this example, has a flat plate-type structure made of metal, for example.

[0109] Fig. 13(A) is a diagram showing an outline of a bottom element (the illustrated example is a waist bottom 123, the same applies below), and Fig. 13(B) is a diagram showing an example of a bottom element to which a sensor device 5 is attached. The following description will be made with reference to the drawings. Each bottom element has a plurality of through holes 123a, 123b that penetrate the bottom element in the thickness direction from the upper surface to the lower surface. These multiple through holes 123a, 123b can function as vents that improve ventilation of the bottom surface of a mattress placed on the bottom 2.

[0110] A plurality of first through holes 123 a are formed along the first direction of the bottom element. When the sensor device 5 is attached to the bottom element, the protrusions 56 of the lever cover 52 can be received inside the first through holes 123 a.

[0111] The second through-hole 123b is used to insert a fastener for attaching the sensor device 5 to the element bottom.

[0112] For example, the sensor device 5 is positioned below the element bottom, with the multiple protrusions 56 of the lever cover 52 exposed upward from the multiple first through holes 123a, the female screw holes of the four arms 53 exposed upward from the four second through holes 123b, and the through holes 54a of the two fixing plates 54 respectively positioned above the second through holes 123b, so that each fixing plate 54 and each arm 53 is fixed to the element bottom by each fixing screw (not shown), and the sensor device 5 is firmly fixed to the element bottom in a hanging manner.

[0113] The above-described configuration and the shape of the bottom element shown in the drawings are merely examples. For example, the first through-hole 123a and the second through-hole 123b formed in the bottom element may be formed by processing a flat metal bottom element to match the shape of the sensor device 5, or the sensor device 5 may be formed to match the shape of holes pre-formed in the bottom element. Note that while an example of the waist bottom 123 has been illustrated and described here, the same applies to other bottom elements.

[0114] 14 is a diagram showing a second modified example of bottom elements. Each of the bottom elements, such as the back bottom, waist bottom, knee bottom, and foot bottom, in this example, has a flat plate-type structure made of resin, for example.

[0115] Fig. 14(A) is a diagram showing an outline of a bottom element (the illustrated example is a waist bottom 323, the same applies below), and Fig. 14(B) is a diagram showing an example of a bottom element to which a sensor device 5 is attached. Each bottom element has a plurality of through holes 323a, 323b. The plurality of through holes 323a, 323b function as through holes that penetrate each bottom element in its thickness direction from its upper surface to its lower surface. For example, the plurality of through holes 323a, 323b may be air vents that are pre-formed in each bottom element to improve ventilation of a mattress placed on the bottom.

[0116] In this example, the configuration of each bottom element is the same as in the first modification, but it differs in that it is made of resin. Resin bottom elements like this one make it easier to form through holes and reduce contact noise with other components compared to metal bottom elements.

[0117] 15 is a diagram showing a third modified example of bottom elements. Each of the bottom elements, such as the back bottom, waist bottom, knee bottom, and leg bottom, in this example has a flat metal plate structure, similar to the first modified example (FIG. 13). The bottom elements of this example (the illustrated example is the waist bottom 223, and the same applies below) are similar to the first modified example in terms of the configuration for attaching each sensor device 5 (specifically, the configuration of the first through-hole 223a and the second through-hole 223b), but differ from the first modified example in that the position of the sensor device 5 can be changed.

[0118] Fig. 15(A) is a diagram showing an outline of a bottom element, and Figs. 15(B), (C), and (D) are diagrams showing examples of bottom elements to which a sensor device 5 is attached. The following description will be made with reference to the drawings.

[0119] The bottom element of this example has a greater number of first through holes 223a and second through holes 223b along the first direction than the second modification example, which makes it possible to change the position of the sensor device 5 in the width direction of the bed 1, as shown in Figures 15(B) and 15(D).

[0120] The bottom element is also provided with a plurality of sets of first through holes 223a and second through holes 223b along the second direction, each set corresponding to one of the sensor devices 5. This allows the position of the sensor device 5 to be variable in the length direction of the bed 1, as shown in Figures 15(C) and 15(D), for example.

[0121] 16 is a diagram showing a fourth modified example of bottom elements. Each of the bottom elements, such as the back bottom, waist bottom, knee bottom, and leg bottom, in this example has a flat resin structure, similar to the third modified example (FIG. 15). The bottom elements in this example (the illustrated example is the waist bottom 423, and the same applies below) are similar to those in the second modified example in terms of the configuration for attaching each sensor device 5 (specifically, the configuration of the first through-hole 423a and the second through-hole 423b), but differ from the second modified example in that the position of the sensor device 5 can be changed.

[0122] Fig. 16(A) is a diagram showing an outline of a bottom element, and Figs. 16(B), (C), and (D) are diagrams showing examples of bottom elements to which a sensor device 5 is attached. The following description will be made with reference to the drawings.

[0123] The bottom element of this example has a greater number of first through holes 423a and second through holes 423b along the first direction than the second modification example, which makes it possible to change the position of the sensor device 5 in the width direction of the bed 1, as shown in Figures 16(B) and 16(D), for example.

[0124] The bottom element is also provided with a plurality of sets of first through holes 423a and second through holes 423b along the second direction, each set corresponding to one of the sensor devices 5. This allows the position of the sensor device 5 to be variable in the length direction of the bed 1, as shown in Figures 16(C) and 16(D), for example.

[0125] The above-described embodiments are merely examples for the purpose of explanation, and are not intended to limit the scope of the present invention to these embodiments. The present invention can be implemented in various forms other than the above-described embodiments.

[0126] 1: Bed, 2: Bottom, 4: User detection system, 5: Sensor device, 6: Monitoring and control device, 7: Bottom drive system, 9: Nurse call system, 11: Base frame, 12: Center frame, 13: Head frame, 14: Foot frame, 15: Caster, 16: Lifting mechanism, 21: Back bottom, 21A: Upper back bottom, 21B: Lower back bottom, 21C: Back bending hinge, 23: Waist bottom, 24: Back lift hinge, 25: Knee bottom, 26: Knee bending hinge, 27: Foot bottom, 28: Knee lift hinge, 31: Outer frame, 33A: Vertical wire, 33B: Horizontal wire, 35: Through hole, 51: Support body, 51a: Bottom wall, 51b: Side wall, 51c: Top part, 52: Lever cover, 52a : Top wall, 52b: Side wall, 52c: Bottom, 53: Arm, 54: Fixing plate, 54a: Through hole, 56: Convex portion, 57: Groove, 58: Support rod, 58a: Lower end, 71: Pressure sensor, 72: Cushioning material, 73: Coil spring, 90: Portable communication terminal, 91: Handset, 92: Base unit, 123: Waist bottom, 123a: First through hole, 123b: Second through hole , 153: arm, 153a: locking hole, 154: fixing plate, 155: locking protrusion, 155a: tip portion, 155b: inclined surface, 223: waist bottom, 223a: first through hole, 223b: second through hole, 323: waist bottom, 323a: first through hole, 323b: second through hole, 423: waist bottom, 423a: first through hole, 423b: second through hole

Claims

1. A user detection system for detecting the state of a user on a bed, the user detection system comprising: a plurality of sensor devices that detect the load of the user and emit a signal corresponding to the load; and a monitoring and control device that receives the signals from the plurality of sensor devices and detects the state of the user, the user detection system being configured so as to be removably attached to the bed as an after-market addition, and the plurality of sensor devices being removably attached to a plurality of different positions in a planar view of the bottom in a manner such that they are suspended from the bottom of the bed.

2. The user detection system of claim 1, wherein the bottom has a plurality of through holes which penetrate the bottom in its thickness direction and can function as air vents, each of the sensor devices has a pressurized portion which is pressed by the weight of the user, and when each of the sensor devices is attached to the bottom, the pressurized portion is inserted into the through hole from below, and each of the sensor devices is configured to sense the weight of the user by the pressurized portion in the through hole being pressed by a mattress placed on the bottom.

3. A user detection system as described in claim 2, wherein, when each of the sensor devices is attached to the bottom, the upper surface of the pressed portion is positioned at the same height as or lower than the upper surface of the bottom so that the bottom surface of the mattress enters the through hole due to the user's weight, causing the mattress to press the upper surface of the pressed portion.

4. A user detection system as described in claim 2 or 3, wherein when the bottom has a greater number of through holes than the number of the sensor devices, the mounting position of each of the sensor devices on the bottom can be changed by changing the through hole into which the pressurized portion of each of the sensor devices is inserted.

5. The user detection system according to claim 2 or 3, wherein the bottom is a bottom having a mesh structure, and a plurality of meshes of the bottom having the mesh structure are utilized as the plurality of through holes.

6. The user detection system according to claim 2 or 3, wherein the bottom is a flat bottom made of metal or resin, the flat bottom has a plurality of air vents, and the plurality of air vents are utilized as the plurality of through holes.

7. The user detection system of claim 1, further comprising a fastener for removably attaching the sensor device to the bottom, the fastener being configured so that an operator can fasten the sensor device to the bottom using a screw or with a one-touch fastening.

8. The user detection system according to claim 7, wherein the fixing device has a snap-fit ​​connection structure that enables an operator to fix the sensor device to the bottom with a single touch.

9. The user detection system of claim 7 or 8, wherein an upper surface of the fixture is located at the same height as or lower than an upper surface of the bottom.

10. A user detection system as described in claim 1, comprising eight of the sensor devices, wherein when the user is lying on his / her back on the bed with his / her body stretched straight and his / her height aligned along the longitudinal direction of the bed, two of the sensor devices selected from the eight sensor devices are attached to each of four areas of the bottom that receive loads from four parts of the back of the upper body, the lower back including the part from the lower back to the buttocks, the upper part of the lower legs including the part from the thighs to the knees, and / or the lower part of the lower legs including the part from the lower legs to the feet, and the two sensor devices attached to each of the areas of the bottom are respectively positioned in a first half area from the center in the width direction of each of the areas of the bottom to one end in the width direction and a second half area from the center in the width direction of each of the areas of the bottom to the other end in the width direction.

11. The user detection system of claim 1, wherein the bottom has four element bottoms: a back bottom that supports the back of the user's upper body, a waist bottom that supports the waist including the portion of the user from the lower waist to the buttocks, a knee bottom that supports the upper portion of the user's lower leg including the portion from the thigh to the knee, and a foot bottom that supports the lower portion of the user's lower leg including the portion from the lower leg to the foot, and the angles of the back bottom, knee bottom and foot bottom relative to the horizontal are variable, the user detection system comprises eight of the sensor devices, and two of the sensor devices selected from the eight sensor devices are attached to each of the four element bottoms, and the two sensor devices attached to each of the element bottoms are respectively arranged in a first half-area from the center in the width direction of each of the element bottoms to one end in the width direction and a second half-area from the center in the width direction of each of the element bottoms to the other end in the width direction.

12. The user detection system of claim 2, wherein each of the sensor devices has a support and a lever cover arranged on the upper side of the support, the lever cover has a fulcrum supported by the support and an extension portion extending in one direction from the fulcrum in a planar view, the extension portion being rotatable in the vertical direction around the fulcrum and being elastically lifted up from the support, the lever cover having the pressed portion on an upper portion of the extension portion, and each of the sensor devices is positioned such that the one direction in which the extension portion extends is along the width direction of the bottom and such that in a planar view the pressed portion is closer to the center of the width direction of the bottom than the fulcrum.

13. The user detection system of claim 12, wherein each of the sensor devices comprises a cushion arranged below the extension portion of the lever cover, and a pressure sensor arranged above the support body and below the cushion, and is configured such that when the pressed portion is pressed downward by the user's weight, the lever cover descends and applies pressure to the pressure sensor via the cushion, and the pressure sensor outputs a signal corresponding to the pressure.

14. A user detection system as described in claim 12 or 13, wherein the bottom has two or more through holes arranged at different positions in the width direction of the bottom, and each of the sensor devices has two or more pressable parts on an upper part of the extension part arranged at different positions in the one direction in which the extension part extends in a planar view, and when each of the sensor devices is attached to the bottom, the two or more pressable parts are respectively inserted into two or more through holes arranged in the width direction of the bottom.

15. The user detection system according to claim 12 or 13, wherein the lever cover of each of the sensor devices covers the entire area of ​​the upper side of the support from above.

16. The user detection system of claim 11, wherein the monitoring and controlling device is disposed below the waist bottom.

17. The user detection system of claim 11, wherein the bed is provided with a bottom drive system that drives one or more of the bottom elements, and the monitoring and control device is connected to the bottom drive system and detects the state of the user based on the signals from the multiple sensor devices and signals related to the drive of the bottom elements from the bottom drive system.

18. The user detection system of claim 1, wherein each of the plurality of sensor devices has a pressurized portion that is pressed by the user's load and a pressure sensor that detects the user's load via the pressurized portion, the pressurized portion being inserted into a through hole that penetrates the bottom in the thickness direction, and each sensor device is configured to detect the user's load by the pressurized portion being pressed.

19. The user detection system of claim 18, wherein the bed has a mattress placed on the bottom, and the weight of the user causes the mattress to bulge into the through hole, thereby pressing the pressed portion.

20. The sensor device included in the user detection system of claim 1.

21. A bed comprising the user detection system of claim 1.

Images