JP7540681B2 - Mattress unit - Google Patents

Description

The present invention relates to a mattress unit and a control device.

In recent years, in hospitals and nursing facilities, there has been a risk that patients, elderly people, and other care recipients may fall out of bed or trip when trying to get up and leave the bed on their own. For this reason, a system is known that detects when a care recipient leaves bed and notifies the caregiver (see, for example, Patent Document 1).

JP 2011-245059 A

The present invention aims to provide a mattress unit that reduces false positives when detecting when a user has left the bed.

In order to achieve the above object, the present invention is realized in the following aspects.
(1) One aspect of the present invention is a mattress unit comprising a mattress body, an air cell provided in the mattress body, a pressure sensor that detects the internal pressure of the air cell, and a control device connected to the pressure sensor, wherein the control device determines whether a user has left bed based on the time period from when a fluctuation occurs in the detected value of the internal pressure until the internal pressure reaches a specified value, and if it determines that the user is left bed, is capable of outputting a bed exit signal indicating that the user has left bed.
(2) In the aspect (1) above, the control device may determine whether the user has left the bed based on a time rate of change of the internal pressure detected by the pressure sensor.
(3) In the above aspect (1) or (2), the control device may determine the user's body movement state based on the time period from when a fluctuation occurs in the detected value of the internal pressure to when the internal pressure reaches a specified value.
(4) In any one of the above aspects (1) to (3), the control device may determine the raised state of the bed based on the time period from when a fluctuation occurs in the detected value of the internal pressure to when the internal pressure reaches a specified value.
(5) In any one of the above aspects (1) to (4), the mattress body may house the control device.
(6) Another aspect of the present invention is a control device that determines whether a user has left the bed, which detects the internal pressure of an air cell provided in the mattress body using a pressure sensor, and determines whether the user has left the bed based on the time from when a fluctuation occurs in the internal pressure until the internal pressure reaches a specified value, and if it is determined that the user is left the bed, is capable of outputting a bed exit signal indicating that the user has left the bed.

The present invention provides a mattress unit and control device with fewer false detections and malfunctions.

1 is a perspective view showing an example of the arrangement of multiple divided mattress bodies for a mattress unit according to an embodiment of the present invention. FIG. 1A is a plan view of one mattress body, FIG. 1B is a side view, and FIG. 1C is a front view. 1A is a diagram showing a first layer portion that constitutes the mattress body, where (a) is a plan view, (b) is a side view, and (c) is a front view. 1A is a diagram showing a second layer portion that constitutes the mattress body, where (a) is a plan view, (b) is a side view, and (c) is a front view. 1A is a diagram showing the end seating support part that constitutes the mattress body, (a) is a plan view, (b) is a side view, and (c) is a front view. FIG. 1A is a plan view of an intermediate mattress body, FIG. 1B is a side view, and FIG. 1C is a front view. FIG. 2 shows a user sitting on the end of the intermediate mattress. A diagram showing the mattress body wrapped in the inner cover. A diagram showing the mattress body stored in the outer cover and folded. FIG. 2 is a block diagram showing a control device according to an embodiment of the present invention.

Below, a mode for carrying out the present invention (hereinafter referred to as "embodiment") will be described in detail with reference to the attached drawings. Note that the same elements are given the same reference numerals throughout the description of the embodiment. In addition, the vertical direction from the head to the feet when the user is lying down is referred to as the longitudinal direction, and the left-right direction intersecting the longitudinal direction when the user is lying down is referred to as the width direction.

First, before describing the control device 90 that determines the user's state of getting out of bed, the overall configuration of the mattress unit 1 in which the control device 90 is used will be described. Note that the state of getting out of bed in this application refers to the transition state in which the user moves from lying down to getting completely out of bed.

(Overall structure of mattress unit)
The mattress unit 1 according to an embodiment of the present invention is capable of dispersing body pressure, and is configured by wrapping a plurality of divided mattress bodies 10 in respective inner covers 20, and placing the mattress bodies 10 in a single outer cover 30 in a longitudinally aligned arrangement. For convenience of explanation, the inner cover 20 and the outer cover 30 are omitted in Fig. 1. The inner cover 20 and the outer cover 30 will be described later.

Each mattress body 10 can be used on both sides (reversible), and has a front and back surface with different hardness, as described below. Figure 1 shows an example in which the mattress body 10 is divided into three parts: an upper mattress body 10a, a middle mattress body 10b, and a lower mattress body 10c. For the lying surface of each mattress body 10, the upper mattress body 10a and the lower mattress body 10c have a first outer surface 40a with a relatively low hardness, and the middle mattress body 10b has a second outer surface 50a with a relatively high hardness.

The number of divisions of the mattress body 10 is not limited to three, and it may be two, four or more. For example, in the case of three divisions as shown here, assuming that the user is a standard adult, the upper mattress body 10a corresponds mainly to the head, the middle mattress body 10b corresponds mainly to the buttocks, and the lower mattress body 10c corresponds mainly to the feet. Incidentally, in the case of four divisions, the four mattress bodies 10 can correspond from the top to the bottom to the head, abdomen, buttocks, and feet. In this embodiment, the upper mattress body 10a and the lower mattress body 10c, which are the divisions of the mattress body 10, have the same configuration, but the configuration of the middle mattress body 10b will be described separately, since it is equipped with an air cell 70 described later for detecting the user's getting out of bed.

(Overview of the mattress itself)
1 and 2, the mattress body 10 includes a first layer 40 and a second layer 50 opposed to the first layer 40. In this embodiment, furthermore, end seating support parts 60 are provided so as to be sandwiched between both ends 41 in the width direction of the first layer 40 and both ends 51 in the width direction of the second layer 50. The first layer 40, the second layer 50, and the end seating support parts 60 are bonded at their respective contact surfaces.

The first layer 40 has a first outer surface 40a with a relatively low hardness, and the second layer 50 has a second outer surface 50a with a relatively high hardness. When the first outer surface 40a of the first layer 40 is used as the lying surface, it gives the user a soft texture, and when the second outer surface 50a of the second layer 50 is used as the lying surface, it gives the user a firm texture, and is configured so that it can be used on both sides. In this embodiment, as described in detail below, the first outer surface 40a is made uneven (slit-shaped) and the second outer surface 50a is made flat, thereby achieving a relative hardness.

The end seating support section 60 is made of a material that is harder than the first layer 40 and the second layer 50 to prevent the user from dropping into a slumped position when sitting on the left or right side of the bed, making it difficult to stand up. Each component of the mattress body 10 will be explained below.

(First layer)
The first layer 40 will be described with reference to Fig. 3. The first layer 40 has uneven portions 42 extending in the width direction at predetermined intervals on the first outer surface 40a. The first layer 40 is formed from a medium-hardness urethane foam, but the uneven portions 42 give the first outer surface 40a a relatively low hardness, providing a lying surface that gently envelops the user's body.

3(b) shows an example in which the uneven portion 42 is composed of 22 convex portions 42a and 21 concave portions 42b between them, but the number and layout of the convex portions 42a and concave portions 42b, as well as the width and height of the convex portions 42a and concave portions 42b, may be set so as to obtain the desired low hardness. Here, the convex portions 42a and concave portions 42b are uniformly arranged except at both ends of the uneven portion 42. At both ends, the convex portions 42a at the very tip of the uneven portion 42 are thicker than the others, and the convex portion 42a one step closer to the center than the very tip is thinner than the others, taking into consideration the balance between the overall width of the mattress body 10 and the width of the uneven portion 42.

The surface opposite the first outer surface 40a of the first layer 40, i.e., the first inner surface 40b located on the side of the second layer 50, is provided with a first reverse groove 43 that extends in the width direction and is open at both ends. The first reverse groove 43 has the effect of preventing moisture from building up when the user uses the mattress unit 1 while lying down, and facilitating drying. Furthermore, when washing the mattress unit 1 separately from the mattress body 10, it also has the effect of making it easy to clean the inside, and easy to drain and dry even after washing.

Here, an example is shown in which multiple grooves having an approximately M-shaped cross section are provided as the first reverse groove portion 43. Here, six first reverse groove portions 43 are provided, but the number is not limited to six and can be any desired number. In some cases, the first reverse groove portion 43 can be omitted. The cross section of the first reverse groove portion 43 is formed in an approximately M-shape, and the center of the M supports part of the body pressure, preventing the mattress body 10 from sinking too much. In addition, the first reverse groove portions 43 in the central region in the longitudinal direction (two toward the center in the figure) are configured to have a lower groove height relative to the first inner surface 40b than the first reverse groove portions 43 in the peripheral region (four in total, two on each side in the figure). This also contributes to preventing the mattress body 10 from deforming and becoming irreversible in the longitudinal central region due to long-term use.

As shown in FIG. 3(c), the first inner surface 40b of the first layer 40 is provided with a plurality of second reverse grooves 44 extending in the longitudinal direction and opening at both ends. The second reverse grooves 44, in combination with the first reverse grooves 43, contribute to ventilation during use and drainage during washing. Here, an example is shown in which a plurality of grooves having an inverted U-shaped cross section are provided as the second reverse grooves 44. In the figure, ten second reverse grooves 44 are provided, but the number is not limited to ten and can be any desired number. In some cases, the second reverse grooves 44 can be omitted. The second reverse grooves 44 are provided in the peripheral regions sandwiching the central region in the width direction, which prevents the central region corresponding to the user's midline from sinking too far (so-called "bottoming out").

At both ends of the width of the first layer 40, an end 41 is provided on the first outer surface 40a side, extending in the width direction. The end 41 has an end support 60 attached to the underside. A fourth groove 45 is provided near the center of the end 41 of the first outer surface 40a, extending in the longitudinal direction across the uneven portion 42. The fourth groove 45 serves as a visual marker that indicates that the end support 60 is provided below the end 41, and contributes to highlighting the difference in hardness between the first layer 40 and the end support 60 covered by the end 41 of the first layer 40. When the fourth groove 45 is provided, the hardness of the end support 60 covered by the end 41 of the first layer 40 can be increased by about 10% overall, compared to when it is not provided.

(Second layer)
Next, the second layer 50 will be described with reference to Fig. 4. The second layer 50 has a second outer surface 50a formed of a flat surface. The first outer surface 40a of the first layer 40 is formed of the uneven portion 42, whereas the second outer surface 50a is formed of a flat surface of medium hardness urethane foam, and therefore has a relatively high hardness compared to the first outer surface 40a. This prevents the body of the user lying down from sinking, and provides a firm lying surface that makes it easy to turn over.

The second inner surface 50b of the second layer 50 is provided with a plurality of fifth grooves 52 extending in the longitudinal direction and opening at both ends. The fifth grooves 52 are provided opposite the left and right ends of the second reverse grooves 44 of the first layer 40. The fifth grooves 52, in combination with the second reverse grooves 44, contribute to ventilation during use and drainage during washing, and are also useful as markers for the location where adhesive is applied between the first layer 40 and the second layer 50. Here, two grooves having a U-shaped cross section are provided as the fifth grooves 52, corresponding to the left and right ends of the second reverse grooves 44, but the number is not limited to two and may be any desired number.

On both ends of the second layer 50 in the width direction, an end 51 is provided on the second outer surface 50a side, extending in the width direction. An end seating support 60 (described later) is attached to the upper surface of the end 51. Although not shown here, a reverse groove extending in the longitudinal direction across the second outer surface 50a may be provided near the center of the end 51 of the second outer surface 50a to perform the same function as the fourth groove 45 provided in the first layer 40.

(Seating support part)
Next, the edge-sitting support part 60 will be described with reference to Fig. 5. In this embodiment, in addition to the first layer part 40 and the second layer part 50, the edge-sitting support part 60 may be provided at the left and right ends of the first layer part 40 and the second layer part 50, so as to be sandwiched between the end part 41 in the width direction of the first layer part 40 and the end part 51 in the width direction of the second layer part 50. The edge-sitting support part 60 is composed of a base layer 61 and a support layer 62 bonded to the upper surface of the base layer 61. The base layer 61 may be formed of high-hardness urethane foam, nonwoven fabric, or the like.

The lower surface 61a of the base layer 61 is provided with a third reverse groove 63 that extends in the width direction at a position corresponding to the first reverse groove 43 of the first layer 40 and is open at both ends. The third reverse groove 63 is connected to the first reverse groove 43 of the first layer 40, and even when the end seating support part 60 is attached to the mattress body 10, it has the effect of preventing moisture from building up when the user lies down and using the mattress unit 1, and making it easier to dry. Furthermore, when washing the mattress unit 1 separately from the mattress body 10, it makes it easier to clean the inside, and even after washing, it has the effect of making it easier to drain and dry.

Here, six third reverse grooves 63 are provided corresponding to the first reverse grooves 43 of the first layer 40, and the number increases or decreases depending on the number of first reverse grooves 43. The third reverse grooves 63 are provided to cover the width direction of the opening of the first reverse grooves 43.

A support layer 62 is provided on the upper surface of the base layer 61. The support layer 62 is formed by compressing nonwoven fabric so that it is made of a harder material than the base layer 61, the first layer 40, and the second layer 50. For example, a nonwoven fabric layer with a thickness of 30 mm is compressed to a thickness of 10 mm by heat pressing. This prevents the user's hips from sinking even when sitting on the left or right end of the upper mattress body 10a or the lower mattress body 10c, stabilizing the edge sitting position, and making it easier for the user to stand up by supporting their weight when they stand up.

(Configuration of intermediate mattress body)
The intermediate mattress body 10b will be described with reference to Fig. 6. The intermediate mattress body 10b houses the 70 and the control device 90, and is different from the upper mattress body 10a and the lower mattress body 10c in that the front and back use surfaces are different, and that the intermediate mattress body 10b does not have the end seating support portion 60. In addition, the intermediate mattress body 10b of this embodiment does not have the first reverse groove portion 43, the second reverse groove portion 44, and the fifth groove portion 52, but they may be formed according to the set hardness.

As shown in FIG. 6, the intermediate mattress body 10b is formed with a first storage section 46 that houses the substantially cylindrical air cell 70 and a second storage section 47 that houses the substantially rectangular control device 90.

When the upper mattress body 10a, the middle mattress body 10b, and the lower mattress body 10c are combined to form the mattress unit 1, the first storage sections 46 are formed near the center of both left and right short sides of the middle mattress body 10b so as to extend along the longitudinal direction of the mattress unit 1. The left and right first storage sections 46 are connected to each other via a connecting passage (not shown).

The first storage section 46 also communicates with the notches 48 formed on the left and right end faces of the intermediate mattress body 10b, and the air cells 70 can be stored by widening the notches 48.

When the upper mattress body 10a, the middle mattress body 10b, and the lower mattress body 10c are combined to form the mattress unit 1, the second storage section 47 is formed on the upper or lower side facing the upper mattress body 10a or the lower mattress body 10c, near the left or right side.

The air cell 70 is formed by stacking two resin sheets (e.g., 80 mm wide x 550 mm long) and welding approximately four sides, excluding the connection ports for air supply or pressure detection. When air is supplied to the inside, it expands into a cylindrical shape, but is designed to withstand an internal pressure of approximately 10.0 kPa (gauge pressure). The left and right air cells 70 have their respective connection ports connected via branch tee and hoses.

As shown in FIG. 7, when the user gets up from a lying position, for example, to sit on the left or right end of the intermediate mattress body 10b, the air cells 70 are compressed by the user's weight, causing the internal pressure of the air cells 70 to rise. Also, instead of the edge seating support portion 60 of the upper mattress body 10a and the lower mattress body 10c, the intermediate mattress body 10b is equipped with air cells 70, and like mattresses equipped with edge seating support portion 60, the lower back is prevented from sinking even when sitting on the left or right end, stabilizing the edge seating position, and supporting the user's weight when standing up, making it easier to stand up.

(Inner cover and outer cover)
Next, the inner cover 20 and the outer cover 30 will be described with reference to Figures 8 and 9. The inner cover 20 is formed in a tubular shape that individually wraps the mattress body 10 (the upper mattress body 10a or the lower mattress body 10c in Figure 8), and is made of synthetic resin such as polyester. It is preferable to form the inner cover 20 from a breathable material such as a mesh in order to prevent stuffiness during use. By wrapping the mattress body 10 in the inner cover 20, it becomes easier to slip the mattress body 10 into and out of the outer cover 30.

The inner cover 20 has an opening on the short side of the mattress unit 1, and the mattress body 10 is inserted and removed through the opening.

Multiple mattress bodies 10 are arranged longitudinally in the outer cover 30, for example in an arrangement as shown in Figure 1, with each individually wrapped in an inner cover 20. The outer cover 30 is made of urethane synthetic leather and is completely waterproof. Even if the user vomits, vomits blood, loses control of urine or has a medication leak, these substances are prevented from penetrating the inside, realizing safety measures such as preventing infection and hygiene measures such as preventing bad odors. It can also be wiped and disinfected with alcohol or the like.

The outer cover 30 has openings on one longitudinal side and one lateral side of the mattress unit 1, and multiple mattress bodies 10 are inserted and removed through the openings. The openings are formed so that they can be closed by providing fasteners, and the fasteners may be any of a zipper, a string, a hook, a safety pin, and the like. At least one longitudinal side of the mattress unit 1 is provided with a handle 31 for the convenience of folding the mattress unit 1 into each mattress body 10, and for the convenience of carrying and adjusting the arrangement on the bed. Figure 9 shows a state in which the middle mattress body 10b is removed from the outer cover 30 and the upper mattress body 10a and the lower mattress body 10c are folded with the middle mattress body 10b sandwiched between them when the mattress body 10 is divided into three parts. Since it can be folded in this way, the mattress unit 1 can be made compact when not in use, thereby saving space.

(Mattress body combination)
As described above, the first outer surface 40a of the first layer 40 of the mattress body 10 provides a relatively low-hardness, soft lying surface, and the second outer surface 50a of the second layer 50 provides a relatively high-hardness, firm lying surface. By changing the arrangement of the multiple mattress bodies 10, it is possible to provide a lying surface for each part of the body according to the user's preference and physical condition. For example, the lying surface of each mattress body 10 may be the first outer surface 40a with a relatively low hardness in the upper mattress body 10a, and the second outer surface 50a with a relatively high hardness in the middle mattress body 10b and the lower mattress body 10c. In this way, the mattress unit 1 allows the user to freely select a lying surface with a different texture of the mattress body 10 for each part of the body according to the user's desire.

As already mentioned, the mattress body 10 is divided into three parts, upper/middle/lower, but the number of parts is not limited to three. It is of course also possible to divide it into two parts, upper/lower, or into four or more parts, upper/middle-upper/middle-lower/lower.

Since each of the divided mattress bodies 10 can be handled individually, if it becomes dirty or smells bad, it is only necessary to wash the mattress body 10, which makes the entire washing process, including cleaning, rinsing, spin-drying, and drying, much easier than washing the entire mattress unit 1. This makes it possible to keep the mattress unit 1 clean at all times.

When the mattress unit 1 is used for a long period of time, it inevitably becomes worn down (dented), especially in the area that corresponds to the buttocks. However, with the mattress unit 1 of this embodiment, by replacing only the divided mattress body 10, the entire mattress unit 1 can be used in the same way as if it were new.

(Configuration of the control device)
Finally, the control device 90 for determining whether the user has left the bed will be described below. Fig. 10 is a block diagram showing the control device 90 according to the embodiment of the present invention.

The control device 90 is formed as a housing 90a and is composed of a calculation unit 91 that judges the user's bed exit state, a memory unit 92 that stores the detected value P1 of the internal pressure and the specified value Ps, an input unit 93 that acquires the detected value P1 of the internal pressure of the air cell 70, an output unit 94 that outputs a bed exit signal ON indicating the user's bed exit state to the outside, and a power supply unit 95 that supplies operating power. In this embodiment, the pressure sensor 80 is directly provided as the input unit 93.

The housing 90a is generally rectangular in plan view, and is housed in a second housing section 47 formed in the intermediate mattress body 10b, except for various wiring and piping. The housing 90a is recessed near the connectors of the output section 94 and power supply section 95, and signal wiring and power wiring are connected at this position. In addition, the detection piping connected to the pressure sensor 80 is provided to protrude outside the housing 90a.

The pressure sensor 80 serving as the input section 93 includes a diffused semiconductor pressure transducer, such as the PG-30-101R-N manufactured by Nippon Densan Copal Electronics Co., Ltd.

The output unit 94 is connected to a signal wiring from a nurse call outlet installed in the nurse call system within the facility, and is capable of outputting a bed exit signal ON based on the calculation results of the calculation unit 91.

The power supply unit 95 receives power from an indoor electrical outlet via an AC adapter, and also supplies operating power to the calculation unit 91 and other components to operate them.

The calculation unit 91 then determines whether the user has left the bed based on the time t from when the detected value P1 of the internal pressure of the air cell 70 changes until the internal pressure reaches the specified value Ps. In other words, the calculation unit 91 determines whether the user has left the bed based on the time rate of change Fp of the internal pressure detected by the pressure sensor 80.

Here, the specified value Ps of the internal pressure depends on the hardness (cushioning) of the intermediate mattress body 10b (the first layer 40 and/or the second layer 50) that houses the air cell 70, but should be set to a value that is 0.25 kPa or more larger than the internal pressure P0 in the lying state, and more preferably, 0.50 kPa or more larger. Similarly to the specified value Ps of the internal pressure, the fluctuation time t also depends on the hardness of the intermediate mattress body 10b, but should be set in the range of 0.2 to 1.0 seconds, for example, to 0.5 seconds. Therefore, the time rate of change Fp of the internal pressure should be set to, for example, 0.5 kPa/second or more, but in order to exclude cases where the internal pressure changes instantaneously due to an impact, etc., the detection value P1 that is equal to or greater than the specified value Ps may continue for a certain period of time (for example, 2 seconds or more) as a judgment condition. The internal pressure P0 in a lying down state is usually 3.0 kPa to 3.5 kPa (gauge pressure).

For example, the calculation unit 91 determines whether the detection value P1 of the internal pressure of the air cell 70 fluctuates by 0.25 kPa or more of the specified value Ps in 0.5 seconds as condition 1. If the result of the determination is "YES", the calculation unit 91 determines that the user is in a bed-leaving state and operates to output a bed-leaving signal ON indicating the user's bed-leaving state from the output unit 94 to the outside.

If the result of the determination is "NO", the calculation unit 91 determines that the user is in a state of body movement (turning over), and loops the processing steps to continue monitoring the fluctuation of the detection value P1 of the internal pressure of the air cell 70. Note that the object to which the bed exit signal ON is output may be, for example, a nurse call system, and the signal wiring (nurse call cable) from the output unit 94 may be connected to a nurse call outlet in the room in which the bed is installed.

Here, if the mattress unit 1 of this embodiment is laid on a bed that can be raised (gagged up), the detection value P1 of the internal pressure of the air cell 70 may fluctuate during the transition to raising the back of the bed. In this case, since the detection value P1 changes more slowly than when the user turns over in bed, the judgment result will be "NO" if the above-mentioned set value is used. Therefore, condition 2 (and further condition 3), which has a smaller time change rate Fp of the internal pressure than condition 1, for example, "whether the detection value P1 of the internal pressure of the air cell 70 has changed by 0.05 kPa or more of the specified value Ps in 0.5 seconds", may be added to condition 1 and judged in two or three stages. If only condition 2 is "YES", the calculation unit 91 may judge that the user is in a state of body movement (turning over), and if condition 2 is also "NO", it may be judged that the bed is in a state of raising the back. Alternatively, the judgment may be made by taking in an external signal from an angle detector that detects the angle of the bed's back.

The control device 90 may also be provided with an additional switch for switching the determination function of the calculation unit 91 on/off or enabled/disabled for cases when it is not necessary to determine whether the user has left the bed, such as when cleaning or disinfecting the bed or mattress unit 1.

As described above, the mattress unit 1 according to an embodiment of the present invention comprises a mattress body 10, an air cell 70 provided along the mattress body 10, a pressure sensor 80 for detecting the internal pressure of the air cell 70, and a control device 90 to which the pressure sensor 80 is connected. The control device 90 judges the user's state of getting out of bed based on the fluctuation time t from when the detected value P1 of the internal pressure fluctuates until the internal pressure reaches a specified value Ps, and when it judges that the user is in the state of getting out of bed, it outputs an exit signal ON indicating that the user is in the state of getting out of bed. As a result, the user's state of getting out of bed can be judged by detecting the air pressure, so that electrical contacts can be reduced and the occurrence of erroneous detections and malfunctions due to disconnections can be suppressed.

The control device 90 of the embodiment determines whether the user has left the bed based on the time rate of change Fp of the internal pressure detected by the pressure sensor 80. This makes it possible to avoid detecting slowly changing body movements such as the user turning over in bed.

In this embodiment, the time rate of change of the internal pressure Fp is 0.5 kPa/sec or more. This makes it possible to avoid detecting slowly changing body movements (turning over) such as the user turning over in their sleep.

The specified value Ps of the internal pressure in this embodiment is a value that is 0.25 kPa or more greater than the internal pressure P0 in the lying down state. This makes it possible to avoid detection of simple body movements that distribute the weight of the user, such as turning over in bed, and to detect a state in which the user is sitting on the edge of the bed (specifically, the mattress unit 1, and even more specifically, the intermediate mattress body 10b).

The mattress body 10 of this embodiment houses the air cell 70 and the control device 90. This eliminates the need for space around the bed to install each device for detecting the exit state.

Although the present invention has been described above using embodiments, it goes without saying that the technical scope of the present invention is not limited to the scope described in the above embodiments. In addition, it is clear to those skilled in the art that various modifications and improvements can be made to the above embodiments. Furthermore, it is clear from the claims that forms incorporating such modifications or improvements can also be included in the technical scope of the present invention.

In the above embodiment, the control device 90 determines whether the bed user has left the bed, is moving, or has raised the back of the bed. However, if the internal pressure detection value P1 of the air cell 70 falls below the internal pressure P0 in the lying-down state, it may be determined that the user has moved completely away from the bed from a position seated on the edge of the bed.

In the above embodiment, the pressure sensor 80 is provided inside the housing 90a of the control device 90, but it may be attached directly to the air cell 70 and the detection value P1 may be output from outside the housing 90a to the control device 90 via a signal wire, or it may be provided on a hose connecting the left and right air cells 70.

In the above embodiment, the housing 90a of the control device 90 is housed in the middle mattress body 10b, but it may be housed in the upper mattress body 10a or the lower mattress body 10c. Alternatively, it may be attached to the back side of the bed on which the mattress unit 1 is installed.

In the mattress body 10 of the above embodiment, the first reverse groove portion 43 and the second reverse groove portion 44 are provided, but as long as the first storage portion 46 that stores the air cell 70 is formed, the other configurations are not limited to those of the embodiment.

1 Mattress unit 10 Mattress body, 10a Upper mattress body, 10b Middle mattress body 10c Lower mattress body 20 Inner cover 30 Outer cover, 31 Handle 40 First layer, 40a First outer surface, 40b First inner surface 41 End, 42 Concave and convex portion, 43 First reverse groove, 44 Second reverse groove, 45 Fourth groove 46 First storage portion, 47 Second storage portion, 48 Cut 50 Second layer, 50a Second outer surface, 50b Second inner surface 51 End, 52 Fifth groove 60 End seating support portion 61 Base layer, 62 Support layer, 63 Third reverse groove 70 Air cell 80 Pressure sensor 90 Control device, 90a Housing 91 Calculation unit, 92 Memory unit, 93 Input unit, 94 Output unit, 95 Power supply unit

Claims (1)

A mattress unit comprising an upper mattress body, an intermediate mattress body and a lower mattress body ,
An air cell provided in the intermediate mattress body;
a pressure sensor for detecting an internal pressure of the air cell;
A control device to which the pressure sensor is connected,
The air cells are provided near the center of both short sides of the intermediate mattress body,
The control device determines that the user has left the bed when a time rate of change of the internal pressure detected by the pressure sensor is 0.5 kPa/sec or more.
A mattress unit characterized by: