Fluid mattress and bed system

Abstract

To provide a fluid mattress and bed system capable of determining the position of a user.SOLUTION: The fluid mattress includes a fluid supply means, a fluid passage, a plurality of mutually connected first cells, a plurality of mutually connected second cells, a plurality of mutually connected third cells, a pressure sensor, and a control part. The controller measures a first time during which the pressure of the first cell changes from the third pressure to the fourth pressure when shifting from the third mode to the first mode, measures a second time during which the pressure of the second cell changes from the third pressure to the fourth pressure when shifting from the first mode to the second mode, and measures a third time during which the pressure of the third cell changes from the third pressure to the fourth pressure when shifting from the second mode to the third mode, the position of the sacral region of the user is determined based on the first time, the second time, and the third time.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] FIELD OF THE INVENTION Embodiments of the present invention relate to fluid mattresses and bed systems. [Background technology]

[0002] Electric nursing care beds have adjustable backrest angles. By setting the backrest flat, the user can lie down, and by tilting the backrest, the user can sit up.

[0003] When the back bottom is flat, if the user is not sleeping in the appropriate position on the electric bed, the user's upper body cannot be raised smoothly when the back is raised. If the user's position is significantly off from the specified position, the caregiver can visually determine this. However, if the user's position is slightly off, it is difficult for the caregiver to visually determine this. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-049435 Summary of the Invention [Problem to be solved by the invention]

[0005] It is an object of embodiments of the present invention to provide a fluid mattress and bed system that is capable of determining the position of an occupant. [Means for solving the problem]

[0006] A fluid mattress according to an embodiment of the present invention comprises a fluid supply means capable of supplying a fluid, a fluid passage to which the fluid is supplied from the fluid supply means, a plurality of first cells connected to each other, a plurality of second cells connected to each other, a plurality of third cells connected to each other, a first solenoid valve having a first end connected to the plurality of first cells and a second end connected to the fluid passage, a second solenoid valve having a first end connected to the plurality of second cells and a second end connected to the fluid passage, a third solenoid valve having a first end connected to the plurality of third cells and a second end connected to the fluid passage, an external solenoid valve having a first end connected to the outside and a second end connected to the fluid passage, a pressure sensor that measures the pressure of the fluid in the fluid passage, and a control unit that receives the measurement results of the pressure sensor and controls the fluid supply means, the first solenoid valve, the second solenoid valve, the third solenoid valve, and the external solenoid valve. The control unit can realize a first mode in which the pressure in the second cell and the pressure in the third cell are set to a first pressure and the pressure in the first cell is set to a second pressure or less that is lower than the first pressure; a second mode in which the pressure in the third cell and the pressure in the first cell are set to the first pressure and the pressure in the second cell is set to the second pressure or less; and a third mode in which the pressure in the first cell and the pressure in the second cell are set to the first pressure and the pressure in the third cell is set to the second pressure or less.When transitioning from the third mode to the first mode, the control unit stops the fluid supply means, closes the second solenoid valve and the third solenoid valve, and opens the first solenoid valve and the external solenoid valve, and measures a first time period during which the measurement value of the pressure sensor changes from a third pressure that is lower than the first pressure and higher than the second pressure to a fourth pressure that is lower than the third pressure and higher than the second pressure; when transitioning from the first mode to the second mode, stops the fluid supply means, closes the third solenoid valve and the first solenoid valve, and opens the second solenoid valve and the external solenoid valve, and measures a second time period during which the measurement value of the pressure sensor changes from the third pressure to the fourth pressure; and when transitioning from the second mode to the third mode, stops the fluid supply means, closes the first solenoid valve and the second solenoid valve, and opens the third solenoid valve and the external solenoid valve, and measures a third time period during which the measurement value of the pressure sensor changes from the third pressure to the fourth pressure. The control unit determines that the user's sacrum is located on the first cell when the first time is longer than the second time and the third time, determines that the sacrum is located on the second cell when the second time is longer than the third time and the first time, and determines that the sacrum is located on the third cell when the third time is longer than the first time and the second time.

[0007] A bed system according to an embodiment of the present invention includes a bed bottom, an actuator for tilting the bed bottom, and the fluid mattress. The first cell, the second cell, and the third cell are repeatedly arranged on the bed bottom from the head side to the foot side. When a central cell of a set consisting of one of the consecutively arranged first cell, one of the consecutively arranged second cell, and one of the consecutively arranged third cell corresponds to a predetermined position where the sacrum should be located and a cell adjacent to the central cell corresponds to the determined position of the sacrum, the control unit controls the actuator to tilt the bed bottom so that the central cell is positioned lower than the cell corresponding to the determined position of the sacrum.

[0008] A bed system according to an embodiment of the present invention includes a bed bottom, an actuator for tilting the bed bottom, a position sensor for detecting the position of a user's sacrum on the bed bottom, and a fluid mattress. The fluid mattress includes a fluid supply means capable of supplying a fluid, a fluid passage through which the fluid is supplied from the fluid supply means, a plurality of interconnected first cells, a plurality of interconnected second cells, and a plurality of interconnected third cells, a first solenoid valve having a first end connected to the plurality of first cells and a second end connected to the fluid passage, a second solenoid valve having a first end connected to the plurality of second cells and a second end connected to the fluid passage, a third solenoid valve having a first end connected to the plurality of third cells and a second end connected to the fluid passage, an external solenoid valve having a first end connected to the outside and a second end connected to the fluid passage, a pressure sensor for measuring the pressure of the fluid in the fluid passage, and a control unit that receives measurement results from the position sensor and the pressure sensor and controls the fluid supply means, the first solenoid valve, the second solenoid valve, the third solenoid valve, and the external solenoid valve. The first cell, the second cell, and the third cell are repeatedly arranged on the bottom from the head side to the foot side. The control unit can realize a first mode in which the pressure in the second cell and the pressure in the third cell are set to a first pressure and the pressure in the first cell is set to a second pressure lower than the first pressure, a second mode in which the pressure in the third cell and the first cell are set to the first pressure and the pressure in the second cell is set to the second pressure or less, and a third mode in which the pressure in the first cell and the second cell are set to the first pressure and the pressure in the third cell is set to the second pressure or less. The control unit is configured such that, when a central cell of a set consisting of one of the first cell, one of the second cell, and one of the third cell arranged consecutively corresponds to a predetermined position where the sacrum should be located, and a cell adjacent to the central cell corresponds to the position of the sacrum detected by the position sensor, the actuator tilts the bottom so that the central cell is positioned lower than the cell corresponding to the detected position of the sacrum. [Effects of the Invention]

[0009] According to an embodiment of the present invention, a fluid mattress and bed system capable of determining the position of an occupant can be realized. [Brief explanation of the drawings]

[0010] [Figure 1] 1(a) and (b) are diagrams showing a bed system according to a first embodiment. [Figure 2] FIG. 2 is a diagram showing a fluid mattress according to the first embodiment. [Figure 3] FIG. 3 is a flowchart showing the operation of the fluid mattress according to the first embodiment. [Figure 4] 4(a) to 4(c) are graphs showing the change in pressure in each air cell, with the horizontal axis representing time and the vertical axis representing the pressure in each air cell. [Figure 5] FIG. 5 is a graph showing pressure changes during exhaust, with the horizontal axis representing time and the vertical axis representing pressure inside the air cell. [Figure 6] 6(a) to 6(c) are diagrams showing the positional relationship between the air cells and the sacrum. [Figure 7] FIG. 7 is a flowchart showing the operation of the bed system according to the second embodiment. [Figure 8] 8(a) and (b) are diagrams showing the operation of the bed system according to the second embodiment. [Figure 9] FIG. 9(a) is a diagram showing a bed system according to a third embodiment, and FIG. 9(b) is a partially enlarged cross-sectional view showing a position sensor. [Figure 10] FIG. 10 is a flowchart showing the operation of the bed system according to the third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] First Embodiment

[0012] 1(a) and (b) are diagrams showing a bed system according to this embodiment. 1(a) and 1(b), a bed system 101 according to this embodiment is a bed system for nursing care or medical use. The bed system 101 is used, for example, in a user's home, a nursing home, or a medical facility such as a hospital. A user U of the bed system 101 is, for example, a person requiring nursing care or a patient.

[0013] The bed system 101 includes an electric bed 100 and a fluid mattress 1. The electric bed 100 includes a bottom 110 and an actuator 120. The bottom 110 includes, from the head side to the foot side of the electric bed 100, a back bottom 111, a waist bottom 112, a knee bottom 113, and a leg bottom 114.

[0014] The back bottom 111 is movable relative to the waist bottom 112. For example, the back bottom 111 can be tilted so that the head side is displaced upward while moving toward the head side relative to the waist bottom 112. This action is called "raising the back." The knee bottom 113 is also movable relative to the waist bottom 112. For example, the knee bottom 113 is rotatably connected to the waist bottom 112. The leg bottom 114 is rotatably connected to the knee bottom 113 and moves in conjunction with the knee bottom 113.

[0015] Fig. 1(a) shows a state in which the back bottom 111, the waist bottom 112, the knee bottom 113 and the leg bottom 114 are all flat. Fig. 1(b) shows a back-raised state in which the back bottom 111 is inclined relative to the waist bottom 112, the knee bottom 113 is inclined relative to the waist bottom 112, and the leg bottom 114 is linked to the knee bottom 113. Note that Fig. 1(b) shows only the electric bed 100, and the fluid mattress 1 is omitted.

[0016] The actuator 120 can tilt the entire bottom part 110. That is, the actuator 120 can make the bottom part 110 parallel to the floor, can tilt the bottom part 110 so that the head side is higher than the foot side, or can tilt the bottom part 110 so that the foot side is higher than the head side. The actuator 120 can also tilt the back bottom part 111 relative to the waist bottom part 112, and can also tilt the knee bottom part 113 relative to the waist bottom part 112. Note that a plurality of actuators 120 may be provided for different functions. For example, an actuator that tilts the entire bottom part 110, an actuator that tilts the back bottom part 111, and an actuator that tilts the knee bottom part 113 may be separate.

[0017] Next, the configuration of the fluid mattress 1 will be described. FIG. 2 is a diagram showing a fluid mattress according to this embodiment. 2, the fluid mattress 1 is provided with a blower 10, a fluid passage 20, air cells 31-33, solenoid valves 41-44, a pressure sensor 50, and a control unit 60. The air cells 31-33 are disposed above the bottom 110. The blower 10, solenoid valves 41-44, pressure sensor 50, and control unit 60 are disposed within a drive unit 70, which is disposed, for example, below the bottom 110.

[0018] The blower 10 is a fluid supply means capable of supplying air as a fluid. The blower 10 may be, for example, a pump. The fluid passage 20 is connected to the blower 10, and air is supplied from the blower 10. In this specification, "connected" means that a fluid can flow.

[0019] A plurality of air cells 31 to 33 are provided, and are repeatedly arranged in a direction from the head side to the foot side of the electric bed 100. The air cells 31 to 33 are made of a soft sheet material and can be filled with air. For example, the air cells 31, 32, and 33 have the same size and shape.

[0020] Each of the solenoid valves 41 to 44 has a first end and a second end, and can switch between permitting and prohibiting the flow of air between the first end and the second end. The plurality of air cells 31 (first cells) are connected to each other and are connected to a first end of the solenoid valve 41 (first solenoid valve). The plurality of air cells 32 (second cells) are connected to each other and are connected to a first end of the solenoid valve 42 (second solenoid valve). The plurality of air cells 33 (third cells) are connected to each other and are connected to a first end of the solenoid valve 43 (third solenoid valve).

[0021] That is, in the fluid mattress 1, a plurality of air cells that are the same size and shape and arranged in a row are divided into three flow paths by solenoid valves 41 to 43. A first end of solenoid valve 44 (external solenoid valve) is connected to the outside of the fluid mattress 1 and can draw in or discharge atmospheric air as air. Second ends of solenoid valves 41 to 44 are connected to the fluid passage 20.

[0022] The pressure sensor 50 measures the pressure of air in the fluid passage 20. The control unit 60 receives the measurement result of the pressure sensor 50 and controls the air blower 10 and the solenoid valves 41 to 44. The control unit 60 can perform a bedsore prevention operation. When the control unit 60 performs a bedsore prevention operation, it repeatedly performs a first mode, a second mode, and a third mode, which will be described later.

[0023] Next, the operation of the bed system according to this embodiment will be described. First, the general operation of the fluid mattress 1 will be described. FIG. 3 is a flowchart showing the operation of the fluid mattress according to this embodiment. 4(a) to (c) are graphs showing the change in pressure in each air cell, with time on the horizontal axis and pressure in each air cell on the vertical axis. FIG. 4(a) shows the change in pressure in air cell 31, FIG. 4(b) shows the change in pressure in air cell 32, and FIG. 4(c) shows the change in pressure in air cell 33.

[0024] As shown in step S11 of FIG. 3 and FIGS. 4(a) to 4(c), the control unit 60 realizes an initial state M0. In the initial state M0, the control unit 60 sets the internal pressure of all of the air cells 31 to 33 to a first pressure P1. The first pressure P1 is a pressure that maintains all of the air cells 31 to 33 in a moderately inflated state when a user U is lying on the fluid mattress 1, and enables the air cells 31 to 33 to comfortably support the user. For example, the first pressure P1 is a pressure that maximizes the contact area between the air cells 31 to 33 and the user. For example, the value of the first pressure P1 is set in advance in relation to the weight of the user.

[0025] Next, the control unit 60 determines whether the bedsore prevention operation is on or off, as shown in step S12 of Fig. 3. If the bedsore prevention function is on, the process proceeds to step S13.

[0026] In step S13, the control unit 60 measures the first time T1. The first time T1 is measured when transitioning from the initial state M0 or the third mode M3 to the first mode M1. The method for measuring the first time T1 will be described later.

[0027] Next, the process proceeds to step S14, where the first mode M1 is executed. As shown in FIG. 2 and FIGS. 4(a) to 4(c), in the first mode M1, the pressure in the air cells 32 and 33 is set to a first pressure P1, and the pressure in the air cell 31 is set to a second pressure P2 or less. The second pressure P2 is lower than the first pressure P1. The pressure in the air cell 31 is set to, for example, a pressure close to atmospheric pressure. As a result, the user is supported by the air cells 32 and 33, but not by the air cell 31. The duration of the first mode M1 is, for example, 5 minutes.

[0028] Next, the process proceeds to step S15, where the control unit 60 measures the second time T2. The second time T2 is measured when the mode transitions from the first mode M1 to the second mode M2. The method for measuring the second time T2 will be described later.

[0029] Next, the process proceeds to step S16, where the second mode M2 ​​is executed. In the second mode M2, the pressure in the air cell 31 is returned to the first pressure P1, and the pressure in the air cell 32 is set to a second pressure P2 or less. The pressure in the air cell 32 is set to, for example, a pressure close to atmospheric pressure. As a result, the user is supported by the air cells 31 and 33, but not by the air cell 32. The duration of the second mode M2 ​​is, for example, five minutes. Note that FIG. 2 shows the second mode M2.

[0030] Next, the process proceeds to step S17, where the control unit 60 measures the third time T3. The third time T3 is measured when the mode transitions from the second mode M2 ​​to the third mode M3. The method for measuring the third time T3 will be described later.

[0031] Next, the process proceeds to step S18, where the third mode M3 is executed. In the third mode M3, the pressure in the air cell 32 is returned to the first pressure P1, and the pressure in the air cell 33 is set to a pressure close to atmospheric pressure, for example. As a result, the user is supported by the air cells 31 and 32, but not by the air cell 33. The duration of the third mode M3 is, for example, five minutes.

[0032] Next, the process proceeds to step S19, where the control unit 60 determines the position Xs of the sacrum of the user U based on the measured values ​​at the first time T1, the second time T2, and the third time T3. This determination method will also be described later.

[0033] Next, the process proceeds to step S20, where the control unit 60 determines whether the position Xs of the sacrum is at the predetermined position X0, and if the position Xs of the sacrum is at the predetermined position X0, the process returns to step S12.

[0034] If the bedsore prevention operation is ON in step S12, the process proceeds to step S13 again, and the operations of steps S13 to S20 are repeated. If the bedsore prevention operation is OFF, the process proceeds from step S12 to step S22, the initial state M0 is realized, and then the control unit 60 ends its operation. Even after the control unit 60 ends its operation, the internal pressure of the air cells 31 to 33 remains at the first pressure P1.

[0035] In step S20, if the control unit 60 determines that the sacral position Xs is not the predetermined position X0, the process proceeds to step S21, where a caution signal is output. The caution signal will be described in detail later. Then, the process returns to step S12.

[0036] In this way, when the bedsore prevention operation is on, the control unit 60 sequentially reduces the internal pressure of the plurality of air cells 31, the plurality of air cells 32, and the plurality of air cells 33 to below the second pressure P2. This causes parts of the user U's body that are not pressed by the air cells to move little by little, thereby suppressing the occurrence of bedsores.

[0037] Next, each operation will be described in detail. First, a method for realizing the initial state M0 shown in step S11 of FIG. 3 will be described.

[0038] As shown in FIGS. 2 and 4(a) to 4(c), in the initial state M0, the control unit 60 drives the blower 10 with the solenoid valves 41 to 43 open and the solenoid valve 44 closed. This causes air to be injected from the blower 10 into the air cells 31 to 33 via the fluid passage 20 and the solenoid valves 41 to 43. Then, when the measurement value of the pressure sensor 50 reaches the first pressure P1, the blower 10 is stopped. Because the solenoid valves 41 to 43 are open, the air cells 31 to 33 are interconnected and at the same pressure. In this way, the pressure in all of the air cells 31 to 33 becomes the first pressure P1.

[0039] Next, a method for measuring the first time T1 shown in step S13 of FIG. 3, a method for measuring the second time T2 shown in step S15, and a method for measuring the third time T3 shown in step S17 will be described. FIG. 5 is a graph showing pressure changes during exhaust, with the horizontal axis representing time and the vertical axis representing pressure inside the air cell.

[0040] As shown in FIG. 5, in this embodiment, a third pressure P3 and a fourth pressure P4 are set. The third pressure P3 is lower than the first pressure P1 and higher than the second pressure P2. The fourth pressure P4 is lower than the third pressure P3 and higher than the second pressure P2. That is, P1>P3>P4>P2. In one example, the first pressure P1 is atmospheric pressure plus approximately 3 kPa (kilopascals), the third pressure P3 is atmospheric pressure plus 2 kPa, the fourth pressure P4 is atmospheric pressure plus 0.7 kPa, and the second pressure P2 is atmospheric pressure plus 0.4 kPa. The atmospheric pressure is approximately 101 kPa.

[0041] First, a method for measuring the second time T2 shown in step S15 will be described. When transitioning from the first mode M1 to the second mode M2, the control unit 60 stops the blower 10, closes the solenoid valves 41 and 43, and opens the solenoid valves 42 and 44. This connects the air cell 32 to the outside. At this time, the user crushes the air cell 32, causing air to be discharged from the air cell 32 to the outside.

[0042] As shown in Figure 5, as air is discharged from the air cell 32 to the outside, the pressure inside the air cell 32 decreases. The rate at which the pressure decreases depends on the force applied to the air cell 32. The greater the force applied to the air cell 32, the longer it takes for the air to be discharged. This is because, while the solenoid valve 44 limits the air passing speed, the greater the force applied to the air cell 32, the greater the amount of air discharged between the third pressure P3 and the fourth pressure P4, and the longer it takes to discharge the air.

[0043] The control unit 60 stores the time t0 when the measurement value of the pressure sensor 50 reaches the third pressure P3. Next, the control unit 60 stores the time t1 when the measurement value of the pressure sensor 50 reaches the fourth pressure P4. The control unit 60 then calculates a second time T2 (=t1-t0) for the pressure in the air cell 32 to change from the third pressure P3 to the fourth pressure P4.

[0044] The third time T3 and the first time T1 are calculated in the same manner. That is, as shown in step S17, when transitioning from the second mode M2 ​​to the third mode M3, the control unit 60 stops the blower 10, closes the solenoid valves 41 and 42, opens the solenoid valves 43 and 44, and connects the air cell 33 to the outside. Then, the control unit 60 measures the third time T3 (= t1 - t0) when the measurement value of the pressure sensor 50 changes from the third pressure P3 to the fourth pressure P4.

[0045] Furthermore, as shown in step S13, when transitioning from the initial state M0 or the third mode M3 to the first mode M1, the control unit 60 stops the blower 10, closes the solenoid valves 42 and 43, opens the solenoid valves 41 and 44, and connects the air cell 31 to the outside. Then, the control unit 60 measures the first time T1 (= t1 - t0) when the measurement value of the pressure sensor 50 changes from the third pressure P3 to the fourth pressure P4. Figure 5 shows a case where the second time T2 indicated by the solid line is longer than the third time T3 and the first time T1 indicated by the dashed lines.

[0046] Next, a method for determining the position Xs of the sacrum of the user shown in step S19 of FIG. 3 will be described. When a user U lies in a supine position on the electric bed 100, the force that the user U applies to the air cells varies depending on the part of the user U's body. Usually, the greatest force is applied to the air cells at position Xs of the user U's sacrum. Therefore, it can be determined that the user U's sacrum is located above the air cell to which the greatest force is applied. In other words, by identifying the air cell to which the greatest force is applied, the position Xs of the sacrum can be identified.

[0047] The control unit 60 determines the position Xs of the sacrum by comparing the first time T1, the second time T2, and the third time T3. Specifically, when the first time T1 is longer than the second time T2 and the third time T3, the control unit 60 determines that the user's sacrum is located on one air cell 31. When the second time T2 is longer than the third time T3 and the first time T1, the control unit 60 determines that the sacrum is located on one air cell 32. When the third time T3 is longer than the first time T1 and the second time T2, the control unit 60 determines that the sacrum is located on one air cell 33.

[0048] Next, a method for determining the relationship between the position Xs of the sacrum and the predetermined position X0 shown in step S20 of FIG. 3 will be described. 6(a) to 6(c) are diagrams showing the positional relationship between the air cells and the sacrum.

[0049] In the electric bed 100, the back bottom section 111 is movable relative to the lumbar bottom section 112. For this reason, it is preferable that a boundary 119 between the back bottom section 111 and the lumbar bottom section 112 and the position Xs of the sacrum have a predetermined relationship. In other words, it is preferable that the sacrum of the user is located at a predetermined position X0 that has a fixed positional relationship with respect to the boundary 119.

[0050] If the actual position Xs of the user's sacrum deviates from the predetermined position X0, when the back bottom 111 is tilted and the back is raised, a part of the user's body may be unnaturally pressed or the user's body may shift, which may cause discomfort to the user. Furthermore, if the user is unable to adjust their posture by themselves, they may not be guided to an appropriate posture. Therefore, in this embodiment, the position Xs of the sacrum is determined using exhaust air from the air cell, as described above.

[0051] As shown in FIGS. 6(a) to 6(c), in this embodiment, a predetermined position X0 where the sacrum of the user U should be positioned is one of the air cells 32 (hereinafter referred to as "air cell 32a").

[0052] As shown in FIG. 6(a), when the position Xs of the sacrum of the user U is positioned on the air cell 32a, the control unit 60 determines that the position Xs coincides with the position X0.

[0053] As shown in FIG. 6(b), in a group 30S consisting of three air cells, namely, air cell 32a, air cell 31 located next to air cell 32a, and air cell 33, if position Xs of the sacrum of user U is located on air cell 31, control unit 60 determines that position Xs does not coincide with position X0.

[0054] As shown in Figure 6(c), in the above-mentioned set 30S, if the position Xs of the sacrum of the user U is located on the air cell 33 in the set 30S, the control unit 60 determines that the position Xs does not coincide with the position X0.

[0055] Next, the output of the caution signal shown in step S21 of FIG. 3 will be described. As described above, the control unit 60 determines whether the determined sacral position Xs coincides with the predetermined position X0 where the sacral should be located, and if not, outputs a warning signal. The warning signal is input to and displayed on the terminal of the caregiver or medical professional (hereinafter also referred to as "caregiver, etc.").

[0056] When the caution signal is displayed, the caregiver manually adjusts the body position of the user U to return it to the appropriate position. Note that if the sacral position Xs deviates from the position X0 beyond the range of set 30S, an appropriate caution signal will not be output, but in this case, the caregiver can visually recognize that the body position of the user U is out of alignment, so there is no problem.

[0057] The caution signal may include information indicating whether the sacral position Xs is located on the head side or the foot side of the predetermined position X0. If the electric bed 100 is provided with a display unit, the caution signal may be input to and displayed on this display unit. Furthermore, even when the sacral position Xs coincides with the position X0, the control unit 60 may output a signal indicating that they coincide.

[0058] Next, the effects of this embodiment will be described. According to this embodiment, the position Xs of the sacrum of the user U can be determined based on the time it takes for the air cells to evacuate. This makes it possible to determine even subtle deviations in the user's position. This effect is particularly effective when the user is using bedding such as a quilt. This allows a caregiver or the like to correct the body position of the user U if the position Xs of the sacrum is deviated from the predetermined position X0. As a result, discomfort to the user can be reduced when the electric bed 100 is operating.

[0059] Furthermore, according to this embodiment, the position Xs of the sacrum is determined using the bedsore prevention operation. Therefore, there is no need to perform a dedicated operation to determine the position Xs of the sacrum. Furthermore, because the position Xs of the sacrum can be determined for each cycle of the bedsore prevention operation, even if the user's posture or the state of the electric bed 100 changes, the position Xs of the sacrum can be determined accordingly. As a result, the position of the user can be constantly tracked, and a warning signal can be output if the user's position shifts. This eliminates the need for caregivers and others to pay excessive attention to the user's position, reducing the burden on caregivers and others.

[0060] <Second embodiment> FIG. 7 is a flowchart showing the operation of the bed system according to this embodiment. 8(a) and (b) are diagrams showing the operation of the bed system according to this embodiment. The configuration of the bed system according to this embodiment is the same as that of the first embodiment. In the following explanation, an example will be described in which the control unit 60 of the fluid mattress 1 also controls the actuator 120 of the electric bed 100, but the control unit 60 of the fluid mattress 1 and the control unit of the electric bed 100 may be separate.

[0061] The operation of the bed system according to this embodiment will be described below. As shown in FIG. 7, steps S11 to S20 are carried out in the same manner as in the first embodiment.

[0062] In step S20, if the sacral position Xs is different from the predetermined position X0, the process proceeds to step S31, where it is determined whether the sacral position Xs is located more headward than the predetermined position X0. When the sacral position Xs is located more headward than the predetermined position X0, it means that, within the range of the set 30S consisting of the three air cells, air cell 32a and air cells 31 and 33 adjacent to air cell 32a, the sacral position Xs is located directly above air cell 31, which is located more headward than air cell 32a, as shown in FIG. 6(b). On the other hand, when the sacral position Xs is not located more headward than the predetermined position X0, it means that, within the range of the set 30S, the sacral position Xs is located directly above air cell 33, which is located more footward than air cell 32a, as shown in FIG. 6(c).

[0063] If the sacral position Xs is located closer to the head than the predetermined position X0, the process proceeds from step S31 to step S32, where the actuator 120 tilts the entire bottom 110 so that the head side is higher than the foot side, as shown in FIG. 8(a). As a result, the predetermined position X0 is located lower than the determined sacral position Xs. Then, the process returns to step S13.

[0064] On the other hand, if the sacral position Xs is not located closer to the head than the predetermined position X0, that is, if the position Xs is located closer to the feet than the position X0, the process proceeds from step S31 to step S33, where the actuator 120 tilts the entire bottom 110 so that the feet are higher than the head, as shown in FIG. 8(b). This also positions the predetermined position X0 lower than the determined sacral position Xs. Then, the process returns to step S13.

[0065] This operation can be generally expressed as follows: That is, when the central air cell of set 30S consisting of one air cell 31, one air cell 32, and one air cell 33 arranged in succession corresponds to a predetermined position X0 where the sacrum should be located, and the air cell adjacent to this central air cell corresponds to the determined position Xs of the sacrum, control unit 60 causes actuator 120 to tilt bottom 110 so that the central air cell is positioned lower than the air cell corresponding to the determined position Xs of the sacrum.

[0066] After returning to step S13, the bedsore prevention operation continues as shown in steps S13 to S18. As a result, as shown in Figures 3 and 4, the pressure in the air cells 31 to 33 gradually decreases to pressures equal to or lower than the second pressure P2. As a result, the body of the user U gradually moves downward due to the action of gravity, and the position Xs of the sacrum approaches the predetermined position X0. Thereafter, the operations shown in steps S12 to S20 and S31 to S33 are repeated.

[0067] Then, when the position Xs of the sacrum matches the predetermined position X0, the process proceeds from step S20 to step S34, where the actuator 120 returns the bottom 110 to a flat state. That is, the bottom 110 is made parallel to the floor. Then, the process returns to step S12. After this, it is optional whether or not to continue the bedsore prevention operation.

[0068] Next, the effects of this embodiment will be described. According to this embodiment, if the position Xs of the user U's sacrum deviates from the predetermined position X0, the actuator 120 tilts the bottom 110 while continuing the bedsore prevention operation, thereby automatically correcting the position of the user U to an appropriate position.

[0069] As a result, for example, when a user who is unable to correct their posture by themselves is receiving care at home, the user's position can be adjusted to an appropriate position even if there is no care professional nearby. This reduces the burden on family members and others providing care during home care. Furthermore, because the user's position can be adjusted without touching the user's body, even if a catheter is attached to the user's body at a medical institution, the user's position can be adjusted while preventing the catheter from becoming dislodged.

[0070] In this embodiment, an example has been shown in which a warning signal is not output when the sacral position Xs does not match the predetermined position X0 in step S20, but a warning signal may be output as in the first embodiment. This prevents a caregiver or the like from inadvertently lifting the user's back when the user's position is not appropriate. Furthermore, the warning signal may include information that the bed system is automatically correcting the user's position. Other configurations, operations, and effects of this embodiment are the same as those of the first embodiment.

[0071] <Third embodiment> FIG. 9(a) is a diagram showing a bed system according to this embodiment, and FIG. 9(b) is a partially enlarged cross-sectional view showing a position sensor.

[0072] As shown in Fig. 9(a), in the bed system 103 according to this embodiment, in addition to the configuration of the bed system 101 according to the first embodiment (see Fig. 1(a)), a position sensor 200 is provided between the bottom 110 and the air cells 31 to 33. The position sensor 200 detects the weight of the user U via the air cells 31 to 33, thereby detecting the position Xs of the sacrum of the user U on the bottom 110.

[0073] 9(b), the position sensor 200 is, for example, a pressure distribution sensor that uses electrostatic capacitance. The position sensor 200 is provided with urethane foam 210, and a plurality of anode electrodes 220 are provided on one surface of the urethane foam 210, for example, on the upper surface, and a plurality of cathode electrodes 230 are provided on the other surface of the urethane foam 210, for example, on the lower surface. The anode electrodes 220 and the cathode electrodes 230 are paired one-to-one to form a capacitor via the urethane foam 210.

[0074] In position sensor 200, when a load is applied locally and urethane foam 210 is compressed, the distance between anode electrode 220 and cathode electrode 230 in that area becomes shorter, and the capacitance increases. This allows position sensor 200 to measure pressure distribution. However, position sensor 200 is not limited to a sensor that uses capacitance.

[0075] Next, the operation of the bed system according to this embodiment will be described. FIG. 10 is a flowchart showing the operation of the bed system according to this embodiment.

[0076] 10, the control unit 60 realizes the initial state M0, and if the bedsore prevention operation is on, it performs a process of realizing the first mode M1 shown in step S14, a process of realizing the second mode M2 ​​shown in step S16, and a process of realizing the third mode M3 shown in step S18. At this time, the first time T1, the second time T2, and the third time T3 are not measured.

[0077] Next, as shown in step S41, the position Xs of the sacrum of the user U is determined. At this time, the control unit 60 determines the position Xs of the sacrum based on the detection result of the position sensor 200, rather than comparing the first time T1, the second time T2, and the third time T3. For example, the point where the position sensor 200 detects the strongest pressure is set as the position Xs of the sacrum. The subsequent operations are the same as those in the second embodiment.

[0078] In this embodiment, as in the second embodiment, if the position of the user U is misaligned, this can be detected and automatically corrected. The configuration, operation, and effects of this embodiment other than those described above are the same as those of the second embodiment.

[0079] The above-described embodiments are examples of realizing the present invention, and the present invention is not limited to these embodiments. For example, the present invention also includes embodiments in which some components or steps are added, deleted, or modified in the above-described embodiments.

[0080] For example, while the above-described embodiments have shown examples in which three systems of air cells are provided, this is not limiting. Two systems, or four or more systems of air cells may also be provided. Furthermore, while the above-described embodiments have shown examples in which multiple air cells are arranged in one direction from the head side to the foot side of the conduction bed, this is not limiting and they may also be arranged in the left-right direction. Furthermore, while the above-described embodiments have shown examples in which air is used as the fluid that drives the cells, this is not limiting. For example, water, gel, or oil may also be used as the fluid. Furthermore, the size of each air cell is selected appropriately depending on the location on the bed where it is placed and the desired function, and multiple air cells of different sizes may be combined and used within a single fluid mattress.

[0081] The present invention includes the following aspects.

[0082] (Appendix 1) a fluid supply means capable of supplying a fluid; a fluid passage through which the fluid is supplied from the fluid supply means; a plurality of interconnected first cells; a plurality of interconnected second cells; a plurality of interconnected third cells; a first solenoid valve having a first end connected to the plurality of first cells and a second end connected to the fluid passage; a second solenoid valve having a first end connected to the plurality of second cells and a second end connected to the fluid passage; a third solenoid valve having a first end connected to the plurality of third cells and a second end connected to the fluid passage; an external solenoid valve having a first end connected to the outside and a second end connected to the fluid passage; a pressure sensor for measuring the pressure of the fluid in the fluid passage; a control unit that receives the measurement results of the pressure sensor and controls the fluid supply means, the first solenoid valve, the second solenoid valve, the third solenoid valve, and the external solenoid valve; Equipped with The control unit a first mode in which the pressure in the second cell and the pressure in the third cell are set to a first pressure, and the pressure in the first cell is set to a second pressure lower than the first pressure; a second mode in which the pressure in the third cell and the pressure in the first cell are set to the first pressure and the pressure in the second cell is set to the second pressure or less; a third mode in which the pressure in the first cell and the pressure in the second cell are set to the first pressure and the pressure in the third cell is set to the second pressure or less; is feasible, The control unit When transitioning from the third mode to the first mode, the fluid supply means is stopped, the second solenoid valve and the third solenoid valve are closed, the first solenoid valve and the external solenoid valve are opened, and a first time is measured for the measurement value of the pressure sensor to change from a third pressure that is lower than the first pressure and higher than the second pressure to a fourth pressure that is lower than the third pressure and higher than the second pressure; When transitioning from the first mode to the second mode, the fluid supply means is stopped, the third solenoid valve and the first solenoid valve are closed, the second solenoid valve and the external solenoid valve are opened, and a second time period is measured for the measurement value of the pressure sensor to change from the third pressure to the fourth pressure; When transitioning from the second mode to the third mode, the fluid supply means is stopped, the first solenoid valve and the second solenoid valve are closed, the third solenoid valve and the external solenoid valve are opened, and a third time is measured for the measurement value of the pressure sensor to change from the third pressure to the fourth pressure; When the first time is longer than the second time and the third time, it is determined that the sacrum of the user is located on the first cell; When the second time is longer than the third time and the first time, it is determined that the sacrum is located on the second cell; A fluid mattress that determines that the sacrum is located on the third cell when the third time is longer than the first time and the second time.

[0083] (Appendix 2) The fluid mattress of Appendix 1, wherein the control unit repeatedly realizes the first mode, the second mode, and the third mode.

[0084] (Appendix 3) A fluid mattress as described in Appendix 1 or 2, wherein the control unit outputs a warning signal when the position of the sacrum determined by the control unit is different from a predetermined position.

[0085] (Appendix 4) Bottom and an actuator for tilting the bottom; A fluid mattress according to any one of appendices 1 to 3; Equipped with the first cells, the second cells, and the third cells are repeatedly arranged on the bottom from a head side to a foot side, The control unit is a bed system in which, when the central cell of a set consisting of one first cell, one second cell, and one third cell arranged in succession corresponds to a predetermined position where the sacrum should be located, and the cell located next to the central cell corresponds to the determined position of the sacrum, the actuator tilts the bottom so that the central cell is positioned lower than the cell corresponding to the determined position of the sacrum.

[0086] (Appendix 5) The bottom is Waist bottom and a back bottom that is movable relative to the waist bottom; and A bed system as described in Appendix 4, wherein the boundary between the waist bottom and the back bottom and the predetermined position have a fixed positional relationship.

[0087] (Appendix 6) Bottom and an actuator for tilting the bottom; a position sensor for detecting the position of the user's sacrum on the bottom; A fluid mattress; Equipped with The fluid mattress comprises: a fluid supply means capable of supplying a fluid; a fluid passage through which the fluid is supplied from the fluid supply means; a plurality of interconnected first cells; a plurality of interconnected second cells; a plurality of interconnected third cells; a first solenoid valve having a first end connected to the plurality of first cells and a second end connected to the fluid passage; a second solenoid valve having a first end connected to the plurality of second cells and a second end connected to the fluid passage; a third solenoid valve having a first end connected to the plurality of third cells and a second end connected to the fluid passage; an external solenoid valve having a first end connected to the outside and a second end connected to the fluid passage; a pressure sensor for measuring the pressure of the fluid in the fluid passage; a control unit that receives measurement results from the position sensor and the pressure sensor and controls the fluid supply means, the first solenoid valve, the second solenoid valve, the third solenoid valve, and the external solenoid valve; and the first cells, the second cells, and the third cells are repeatedly arranged on the bottom from a head side to a foot side, The control unit a first mode in which the pressure in the second cell and the pressure in the third cell are set to a first pressure, and the pressure in the first cell is set to a second pressure lower than the first pressure; a second mode in which the pressure in the third cell and the pressure in the first cell are set to the first pressure and the pressure in the second cell is set to the second pressure or less; a third mode in which the pressure in the first cell and the pressure in the second cell are set to the first pressure and the pressure in the third cell is set to the second pressure or less; The control unit is a bed system in which, when the central cell of a set consisting of one first cell, one second cell, and one third cell arranged in succession corresponds to a predetermined position where the sacrum should be located, and the cell located next to the central cell corresponds to the position of the sacrum detected by the position sensor, the actuator tilts the bottom so that the central cell is positioned lower than the cell corresponding to the detected position of the sacrum.

[0088] (Appendix 7) The bottom is Waist bottom and a back bottom that is movable relative to the waist bottom; and A bed system as described in Appendix 6, wherein the boundary between the waist bottom and the back bottom and the predetermined position have a fixed positional relationship. [Explanation of symbols]

[0089] 1. Fluid Mattress 10. Blower 20 Fluid passage 30S group 31, 32, 32a, 33 Air cells 41, 42, 43, 44 Solenoid valves 50 Pressure Sensor 60 Control Unit 70 Drive Unit 100 Electric Beds 101, 103 Bed System 110 Bottom 111 Back Bottom 112 Waist Bottoms 113 Knee Bottoms 114 Leg Bottom 119 Boundary 120 Actuator 200 Position Sensor 210 urethane foam 220 Anode electrode 230 Cathode electrode t0, t1 time T1 1st Hour T2 2nd Hour T3 Third Hour U user X0 in place Xs Sacral position

Claims

1. a fluid supply means capable of supplying a fluid; a fluid passage through which the fluid is supplied from the fluid supply means; a plurality of interconnected first cells; a plurality of interconnected second cells; a plurality of interconnected third cells; a first solenoid valve having a first end connected to the plurality of first cells and a second end connected to the fluid passage; a second solenoid valve having a first end connected to the plurality of second cells and a second end connected to the fluid passage; a third solenoid valve having a first end connected to the plurality of third cells and a second end connected to the fluid passage; an external solenoid valve having a first end connected to the outside and a second end connected to the fluid passage; a pressure sensor for measuring the pressure of the fluid in the fluid passage; a control unit that receives the measurement result of the pressure sensor and controls the fluid supply means, the first solenoid valve, the second solenoid valve, the third solenoid valve, and the external solenoid valve; Equipped with The control unit a first mode in which the pressure in the second cell and the pressure in the third cell are set to a first pressure, and the pressure in the first cell is set to a second pressure lower than the first pressure; a second mode in which the pressure in the third cell and the pressure in the first cell are set to the first pressure and the pressure in the second cell is set to the second pressure or less; a third mode in which the pressure in the first cell and the pressure in the second cell are set to the first pressure and the pressure in the third cell is set to the second pressure or less; is feasible, The control unit When transitioning from the third mode to the first mode, the fluid supply means is stopped, the second solenoid valve and the third solenoid valve are closed, the first solenoid valve and the external solenoid valve are opened, and a first time is measured for the measurement value of the pressure sensor to change from a third pressure that is lower than the first pressure and higher than the second pressure to a fourth pressure that is lower than the third pressure and higher than the second pressure; When transitioning from the first mode to the second mode, the fluid supply means is stopped, the third solenoid valve and the first solenoid valve are closed, the second solenoid valve and the external solenoid valve are opened, and a second time period is measured for the measurement value of the pressure sensor to change from the third pressure to the fourth pressure; When transitioning from the second mode to the third mode, the fluid supply means is stopped, the first solenoid valve and the second solenoid valve are closed, the third solenoid valve and the external solenoid valve are opened, and a third time is measured for the measurement value of the pressure sensor to change from the third pressure to the fourth pressure; When the first time is longer than the second time and the third time, it is determined that the sacrum of the user is located on the first cell; When the second time is longer than the third time and the first time, it is determined that the sacrum is located on the second cell; A fluid mattress that determines that the sacrum is located on the third cell when the third time is longer than the first time and the second time.

2. The fluid mattress of claim 1 , wherein the control unit repeatedly implements the first mode, the second mode, and the third mode.

3. The fluid mattress according to claim 1 , wherein the control unit outputs a warning signal when the position of the sacrum determined by the control unit is different from a predetermined position.

4. Bottom and an actuator for tilting the bottom; A fluid mattress according to any one of claims 1 to 3; Equipped with the first cells, the second cells, and the third cells are repeatedly arranged on the bottom from a head side to a foot side, The control unit is a bed system in which, when the central cell of a set consisting of one first cell, one second cell, and one third cell arranged in succession corresponds to a predetermined position where the sacrum should be located, and the cell located next to the central cell corresponds to the determined position of the sacrum, the actuator tilts the bottom so that the central cell is positioned lower than the cell corresponding to the determined position of the sacrum.

5. The bottom is Waist bottom and a back bottom that is movable relative to the waist bottom; and The bed system according to claim 4, wherein the boundary between the lower back bottom and the back bottom and the predetermined position have a fixed positional relationship.

6. Bottom and an actuator for tilting the bottom; a position sensor for detecting the position of the user's sacrum on the bottom; A fluid mattress; Equipped with The fluid mattress comprises: a fluid supply means capable of supplying a fluid; a fluid passage through which the fluid is supplied from the fluid supply means; a plurality of interconnected first cells; a plurality of interconnected second cells; a plurality of interconnected third cells; a first solenoid valve having a first end connected to the plurality of first cells and a second end connected to the fluid passage; a second solenoid valve having a first end connected to the plurality of second cells and a second end connected to the fluid passage; a third solenoid valve having a first end connected to the plurality of third cells and a second end connected to the fluid passage; an external solenoid valve having a first end connected to the outside and a second end connected to the fluid passage; a pressure sensor for measuring the pressure of the fluid in the fluid passage; a control unit that receives measurement results from the position sensor and the pressure sensor and controls the fluid supply means, the first solenoid valve, the second solenoid valve, the third solenoid valve, and the external solenoid valve; and the first cells, the second cells, and the third cells are repeatedly arranged on the bottom from a head side to a foot side, The control unit a first mode in which the pressure in the second cell and the pressure in the third cell are set to a first pressure, and the pressure in the first cell is set to a second pressure lower than the first pressure; a second mode in which the pressure in the third cell and the pressure in the first cell are set to the first pressure and the pressure in the second cell is set to the second pressure or less; a third mode in which the pressure in the first cell and the pressure in the second cell are set to the first pressure and the pressure in the third cell is set to the second pressure or less; is feasible, The control unit is a bed system in which, when the central cell of a set consisting of one first cell, one second cell, and one third cell arranged in succession corresponds to a predetermined position where the sacrum should be located, and the cell located next to the central cell corresponds to the position of the sacrum detected by the position sensor, the actuator tilts the bottom so that the central cell is positioned lower than the cell corresponding to the detected position of the sacrum.

7. The bottom is Waist bottom and a back bottom that is movable relative to the waist bottom; and The bed system according to claim 6, wherein the boundary between the lower back bottom and the back bottom and the predetermined position have a fixed positional relationship.

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