Air mattress for wheelchair

Abstract

To provide a user-friendly air mattress for a wheelchair.SOLUTION: An air mattress for a wheelchair comprises: a seat part air mattress to be laid on a seating face part of a wheelchair; a ventilation unit for supplying air to the seat part air mattress; a solenoid valve unit positioned between the seat part air mattress and the ventilation unit; an air pressure sensor for detecting an air pressure within the seat part air mattress; and a controlling unit for controlling the operation of the ventilation unit and the operation of the solenoid valve unit. The seat part air mattress includes a first air cell, and a second air cell positioned at the back of the first air cell, whose air supply / exhaust is controlled differently from that of the first air cell. When the first air cell or the second air cell discharges air, the controlling unit determines the user's position on the basis of the elapsed time until the air pressure drops to a specified level.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] FIELD OF THE INVENTION Aspects of the present invention generally relate to air mattresses for wheelchairs. [Background technology]

[0002] An air mattress that can be placed on a wheelchair is known (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-121365 Summary of the Invention [Problem to be solved by the invention]

[0004] If a wheelchair user's sitting or sleeping position is not appropriate, it may cause discomfort to the user, and using a wheelchair in an inappropriate position may be dangerous. Furthermore, for example, if the user's body is covered with a blanket or the like, it may be difficult to check the user's condition, making it difficult to determine whether the user's sitting or sleeping position is appropriate.

[0005] Aspects of the present invention provide a user-friendly air mattress for a wheelchair. [Means for solving the problem]

[0006] One aspect of the present invention is an air mattress for a wheelchair, comprising: a seat air mattress that is placed on the seat of a wheelchair; an air blower that supplies air to the seat air mattress; an electromagnetic valve unit located between the seat air mattress and the air blower; an air pressure sensor that detects the air pressure inside the seat air mattress; and a control unit that controls the operation of the air blower and the electromagnetic valve unit, wherein the seat air mattress has a first air cell and a second air cell located behind the first air cell and which has air intake and exhaust control different from that of the first air cell, and the control unit determines the position of the user based on the elapsed time for the air pressure to drop to a predetermined level when air is exhausted from the first air cell or the second air cell. [Effects of the Invention]

[0007] Aspects of the present invention can provide an air mattress for a wheelchair that is easy to use. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a side view showing a wheelchair equipped with an air mattress for a wheelchair according to an embodiment of the present invention. [Figure 2] FIG. 1 is a simplified explanatory diagram showing an air mattress unit placed on a wheelchair. [Figure 3] FIG. 1 is a block diagram showing a control system for a wheelchair air mattress. [Figure 4] FIG. 10 is a circuit diagram showing the air supply and exhaust system of the seat air mattress. [Figure 5] FIG. 10 is an explanatory diagram showing a state in which a person is seated on the second air cell of the seat air mattress. [Figure 6] FIG. 10 is a characteristic diagram showing the exhaust state of the air cell depending on the seating position. [Figure 7] 10 is a flowchart showing a control process for detecting a user's position executed by a control unit. DETAILED DESCRIPTION OF THE INVENTION

[0009] An air mattress for a wheelchair according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a side view showing a wheelchair equipped with an air mattress for a wheelchair according to an embodiment of the present invention.

[0010] The wheelchair 100 is designed so that the angle of the backrest 102 and the angle of the footrest 103 can be changed relative to the seat 101 on which the user sits. Specifically, the wheelchair 100 can be changed between a seated position shown by a solid line in FIG. 1 and a bed position shown by a two-dot chain line in FIG. 1. The position of the wheelchair 100 can be changed, for example, by operating the handle 110. In this example, the wheelchair 100 is designed so that the backrest 102 and the footrest 103 move in conjunction with the seat 101. In the wheelchair air mattress 10, the bed position will be described with the side closest to the user's feet as the "front," the side closest to the head as the "rear," the side closest to the right hand as the "right," and the side closest to the left hand as the "left."

[0011] The wheelchair 100 has handrails 120 on both the left and right sides. The handrails 120 are movable in the up and down direction. When the handrails 120 are positioned at the top, they serve as armrests for the user. On the other hand, as shown in FIG. 1, the wheelchair 100 is designed so that the handrails 120 can be lowered. In FIG. 1, the handrail 120 on the right side is lowered. By lowering the handrails 120 in the bed position, the caregiver can easily transfer the user from the bed into the wheelchair 100.

[0012] FIG. 2 is a simplified explanatory diagram showing an air mattress unit placed on a wheelchair. The wheelchair air mattress 10 (hereinafter referred to as the air mattress 10) is removably attached to the wheelchair 100. The air mattress 10 has an air mattress unit 20 that supports the body of a user using the wheelchair 100. The air mattress 10 is designed so that its hardness can be changed by supplying or exhausting air from the air mattress unit 20. The air mattress 10 includes the air mattress unit 20 and a pump unit 60.

[0013] The air mattress unit 20 has a seat air mattress 30, a back air mattress 40, and a leg air mattress 50. As shown in Fig. 1, the seat air mattress 30, the back air mattress 40, and the leg air mattress 50 are housed inside a cover 15. Fig. 2 shows the unit with the cover 15 removed.

[0014] The seat air mattress 30 is the part that is placed on the seat surface 101 of the wheelchair 100. The seat air mattress 30 has a plurality of air cells 31 that correspond to the seat surface 101 of the wheelchair 100. In this example, the seat air mattress 30 has six air cells 31 lined up in the front-to-rear direction. In this example, an air supply and exhaust section is provided on the back side of each air cell 31 to which a tube 80, which will be described later, is connected.

[0015] The air cells 31 include a first air cell 31a, a second air cell 31b located behind the first air cell 31a and having different air intake and exhaust control from the first air cell 31a, and a third air cell 31c located behind the second air cell 31b and having different air intake and exhaust control from the first air cell 31a and the second air cell 31b. In this example, two of each of the first to third air cells 31a to 31c are provided.

[0016] The first air cells 31a are the air cells 31 located at the frontmost side (towards the leg air mattress 50) and the fourth air cell 31 from the front. The two first air cells 31a are connected to the same tube 80 and are controlled to supply and exhaust air together. The second air cell 31b is the air cell 31 located behind the first air cell 31a. The two second air cells 31b are connected to the same tube 80 and are controlled to supply and exhaust air together. The third air cell 31c is the air cell 31 located behind the second air cell 31b. The two third air cells 31c are connected to the same tube 80 and are controlled to supply and exhaust air together.

[0017] The seat air mattress 30 changes the hardness of each air cell 31 by supplying or discharging air inside each air cell 31. By changing the hardness of each air cell 31, the seat air mattress 30 can provide the user with a comfortable sitting or sleeping experience. In the seat air mattress 30, each air cell 31 is integrally connected by a band 32. The band 32 extends in the front-to-rear direction on the side of each air cell 31.

[0018] The back air mattress 40 is placed on the backrest 102 of the wheelchair 100. The back air mattress 40 has a plurality of air cells 41 corresponding to the backrest 102 of the wheelchair 100.

[0019] In this example, the back air mattress 40 has 11 air cells 41 arranged in the front-to-rear direction. On the back side of each air cell 41, an air supply / exhaust section is provided to which a tube 80 (described later) is connected.

[0020] The air cells 41 of the back air mattress 40 are integrated with the air cells 31 of the seat air mattress 30 by bands 42. The back air mattress 40 differs from the seat air mattress 30 only in number, and otherwise has the same configuration. By changing the hardness of each air cell 41, the back air mattress 40 can provide the user with a comfortable sitting or sleeping experience.

[0021] The leg air mattress 50 is placed on the foot rest 103 of the wheelchair 100. The leg air mattress 50 has a plurality of air cells 51 corresponding to the foot rest 103 of the wheelchair 100. In this example, the leg air mattress 50 has eight air cells 51 lined up in the front-to-rear direction. An air supply and exhaust section is provided on the back side of each air cell 51 to which a tube 80, described below, is connected.

[0022] The air cells 51 of the leg air mattress 50 have a different shape from the air cells 31 of the seat air mattress 30 and the air cells 41 of the back air mattress 40. The leg air mattress 50 is formed so as to become as thin as possible when the air inside it is evacuated. As shown in FIG. 2, the air cells 51 have an upper air cell 52 and a lower air cell 53 that communicates with the upper air cell 52 internally. The upper air cell 52 and the lower air cell 53 are elliptical in shape. When the air inside the leg air mattress 50 is evacuated, it becomes easier for the user to place their feet on the footrest 103 of the wheelchair 100.

[0023] The seat air mattress 30, the back air mattress 40, and the leg air mattress 50 are each separable, so that the air mattress unit 20 allows each of the air mattresses 30, 40, and 50 to be replaced individually.

[0024] The back air mattress 40 and the leg air mattress 50 are able to rise and fall relative to the seat air mattress 30. That is, the air mattress unit 20 is bendable between the seat air mattress 30 and the back air mattress 40, and between the seat air mattress 30 and the leg air mattress 50. This allows the air mattress unit 20 to follow the bed position and the sitting position of the wheelchair 100.

[0025] FIG. 3 is a block diagram showing the control system of the wheelchair air mattress. The pump unit 60 is mounted, for example, below the seat 101 of the wheelchair 100. The pump unit 60 supplies air to the air mattress unit 20. That is, the pump unit 60 controls the hardness of the air mattress unit 20 by supplying and discharging air to and from each of the air cells 31, 41, and 51. The pump unit 60 has a control unit 61, an electromagnetic valve unit 62, an air blower 65, and an air pressure sensor 66.

[0026] The control unit 61 controls the hardness by changing the internal pressure of the air mattress unit 20. The control unit 61 has a memory unit 61a that stores a control program for controlling the hardness of the air mattress unit 20. The control unit 61 controls the operation of the blower unit 65 and the operation of the solenoid valve unit 62.

[0027] The control unit 61 is connected to an operation unit 70 (remote control) and controls the operation of the blower unit 65 and the opening and closing of the solenoid valve unit 62 based on command signals from the operation unit 70. The control unit 61 also executes position detection control to detect the position of the user on the seat air mattress 30. A control program for the position detection control is stored in the memory unit 61a. The position detection control executed by the control unit 61 will be described later.

[0028] The control unit 61 operates using power supplied from a battery 75. The battery 75 is mounted below the seat 101 of the wheelchair 100 and is a rechargeable secondary battery.

[0029] The solenoid valve unit 62 is located between the air mattress unit 20 and the blower 65. The solenoid valve unit 62 has a plurality of solenoid valves. Each solenoid valve is connected to a pipeline 67 and a tube 80. Of the air cells 31, 41, and 51, the same solenoid valve is used for the air cells that are commonly controlled. Note that the number of solenoid valves provided may correspond to the number of air cells 31, 41, and 51. The opening and closing operation of each solenoid valve is controlled by the controller 61.

[0030] The blower 65 supplies air to the air mattress unit 20. Specifically, the blower 65 supplies air to each of the air cells 31, 41, and 51 via the solenoid valve unit 62. The operation of the blower 65 is controlled by the control unit 61. Air is supplied to each of the air cells 31, 41, and 51 by the blower 65 operating while the solenoid valve of the solenoid valve unit 62 is in an open state.

[0031] The air pressure sensor 66 is provided in a pipe 67 connecting the solenoid valve unit 62 and the blower 65. The air pressure sensor 66 detects the internal pressure of the pipe 67, thereby detecting the internal pressure of each of the air cells 31, 41, and 51. The air pressure sensor 66 transmits the detected value to the control unit 61. Based on the detected value of the air pressure sensor 66, the control unit 61 controls the operation of the blower 65 and the opening and closing of each solenoid valve of the solenoid valve unit 62. The control unit 61 also determines the position of the user on the seat air mattress 30 based on the detected value of the air pressure sensor 66.

[0032] The operation unit 70 is connected to the control unit 61. The operation unit 70 serves as a remote control for operating various settings and hardness of the air mattress unit 20. The control unit 61 controls the air intake and exhaust of the air mattress unit 20 based on command signals from the operation unit 70. Furthermore, the operation unit 70 issues warnings by display, sound, vibration, etc. based on the position of the user determined by the control unit 61.

[0033] The angle sensor 76 is capable of detecting the position of the wheelchair 100 or the air mattress unit 20. The angle sensor 76 is provided, for example, in the air mattress unit 20, and detects the angle between the seat air mattress 30 and the back air mattress 40. The angle sensor 76 may also detect, for example, the angle between the seat air mattress 30 and the leg air mattress 50. The angle sensor 76 may also detect, for example, the angle between the seat portion 101 and the backrest portion 102 of the wheelchair 100, or the angle between the seat portion 101 and the footrest portion 103. The angle sensor 76 transmits the detected value to the control unit 61. The control unit 61 controls the internal pressure of the air mattress unit 20 based on the detected value of the angle sensor 76.

[0034] Next, the position detection control for detecting the position of the user in the wheelchair 100 will be described with reference to FIGS. FIG. 4 is a circuit diagram showing the air supply and exhaust system of the seat air mattress.

[0035] 4, the solenoid valve unit 62 has first to fourth solenoid valves 62a to 62d. The first solenoid valve 62a is connected to the first air cell 31a via a pipe 67. The second solenoid valve 62b is connected to the second air cell 31b via a pipe 67. The third solenoid valve 62c is connected to the third air cell 31c via a pipe 67. The fourth solenoid valve 62d is connected to the first to third solenoid valves 62a to 62c via a pipe 67, and serves as an exhaust valve that exhausts air from the first to third air cells 31a to 31c to the outside.

[0036] The control unit 61 operates the blower 65 while the first solenoid valve 62a is in the open state, thereby supplying air to the first air cell 31a. On the other hand, the control unit 61 operates the first solenoid valve 62a and the fourth solenoid valve 62d while in the open state, thereby stopping the blower 65, thereby exhausting air from the first air cell 31a. The same applies to the second and third air cells 31b and 31c.

[0037] Fig. 4 shows a state in which the second solenoid valve 62a and the fourth solenoid valve 62d are open, i.e., a state in which air is being exhausted from the second air cell 31b as indicated by the arrows in Fig. 4.

[0038] The control unit 61 acquires the air pressures (internal pressures) of the first to third air cells 31a to 31c based on the detected values ​​of an air pressure sensor 66 connected to a pipe 67. The control unit 61 controls the opening and closing operations of the blower 65 and the first to fourth solenoid valves 62a to 62d based on the acquired detected values.

[0039] FIG. 5 is an explanatory diagram showing a state in which a person is seated on the second air cell of the seat air mattress. The control unit 61 detects the position of the user H in the front-to-back direction of the seat air mattress 30. Of the first to third air cells 31a to 31c, the air cell 31 located below the ischium H1 of the user H receives the force F most downward. FIG. 5 shows a state in which the ischium H1 of the user H is located above the second air cell 31b. Therefore, the second air cell 31b receives the force F more downward than the first air cell 31a and the second air cell 31c.

[0040] FIG. 6 is a characteristic diagram showing the exhaust state of the air cell depending on the seating position. 6 shows the exhaust state when the ischial bones H1 of the user H are not above the air cell 31. On the other hand, the dotted characteristic line 95 in FIG. 6 shows the exhaust state when the ischial bones H1 of the user H are above the air cell 31.

[0041] The opening (hole diameter) of the fourth solenoid valve 62d is sized so that the air in the air cells 31 does not suddenly escape due to the weight of the user H. Therefore, as shown in Figure 6, the time it takes for the air pressure in the air cells 31 to drop from 5 kPa to a predetermined air pressure (e.g., 0 kPa) is longer when the ischial bones H1 of the user H are above the air cells 31 (time t0 to time t2) than when the ischial bones H1 of the user H are not above the air cells 31 (time t0 to time t1). The control unit 61 detects the position of the user H on the seat air mattress 30 based on this exhaust state.

[0042] FIG. 7 is a flowchart showing a control process for detecting the position of the user executed by the control unit. The memory unit 61a of the control unit 61 stores a position detection control program and an exhaust elapsed time threshold tx shown in Fig. 7. As shown in Fig. 6, the threshold tx is set to a value between the time t1 at which a predetermined air pressure (e.g., 0 kPa) is reached when the user H is not present on the air cell 31 and the time t2 at which a predetermined air pressure (e.g., 0 kPa) is reached when the user H is present on the air cell 31. The control process shown in Fig. 7 is repeatedly executed, for example, at predetermined time intervals or when an operation instruction is received from the operation unit 70. Each step is indicated by "S".

[0043] In S1, air is supplied to the first to third air cells 31a to 31c. That is, the control unit 61 operates the blower 65 with the first to third solenoid valves 62a to 62c in the open position and the fourth solenoid valve 62d in the closed position. Then, when the value detected by the air pressure sensor 66 reaches a first air pressure (for example, 5 kPa), the control unit 61 switches the first to third solenoid valves 62a to 62c to the closed position and stops the blower 65. As a result, the first to third air cells 31a to 31c are inflated with an internal pressure of 5 kPa.

[0044] In the next step S2, the first air cell 31a is vented, the air pressure is acquired, and time measurement begins. That is, the control unit 61 switches the first solenoid valve 62a and the fourth solenoid valve 62d to the open position. As a result, the air in the first air cell 31a is exhausted to the outside via the first solenoid valve 62a and the fourth solenoid valve 62d. The control unit 61 also acquires the detected value (air pressure) detected by the air pressure sensor 66 and measures the elapsed time.

[0045] In the next step S3, it is determined whether the time it takes for the air pressure in the first air cell 31a to decrease to a predetermined air pressure (for example, the second air pressure = 0 kPa) is equal to or greater than the threshold value tx. That is, the control unit 61 monitors the elapsed time for the air pressure in the first air cell 31a to decrease from the first air pressure (5 kPa) to the second air pressure (0 kPa).

[0046] If S3 returns "YES," i.e., if it is determined that the elapsed time until the predetermined air pressure is reached is equal to or greater than the threshold value tx, the process proceeds to S4. In this case, the exhaust flow of the first air cell 31a is as shown by the dotted characteristic line 95 in Figure 6. On the other hand, if S3 returns "NO," i.e., if it is determined that the elapsed time until the predetermined air pressure is reached is less than the threshold value tx, the process proceeds to S5.

[0047] In S4, the control unit 61 issues a first warning from the operation unit 70. That is, when the control unit 61 determines that the user is present on the first air cell 31a, it issues a first warning from the operation unit 70. If the user is positioned on the first air cell 31a, this means that the user is sitting too shallowly on the seat air mattress 30. Therefore, the operation unit 70 issues a first warning, such as a message such as "Please sit down deeply immediately" or by turning on a lamp, and the process ends.

[0048] In S5, air is supplied to the first to third air cells 31a to 31c. That is, when it is determined in S3 that a user is not present on the first air cell 31a, the control unit 61 determines whether a user is present on the second air cell 31b. In S5, the same control process as in S1 is executed. Note that, since only the first air cell 31a is evacuated in S2, air may be supplied only to the first air cell 31a in S5.

[0049] In S6, the second air cell 31b is vented, the air pressure is acquired, and time measurement begins. That is, the control unit 61 switches the second solenoid valve 62b and the fourth solenoid valve 62d to the open position. As a result, the air in the second air cell 31b is exhausted to the outside via the second solenoid valve 62b and the fourth solenoid valve 62d. The control unit 61 also acquires the detected value (air pressure) detected by the air pressure sensor 66 and measures the elapsed time.

[0050] In the next step S7, it is determined whether the time it takes to drop to a predetermined air pressure (for example, second air pressure = 0 kPa) is equal to or greater than a threshold value tx. The control process in S7 is the same as the control process in S3. If S7 returns "YES," that is, if it is determined that the time it takes to drop to the predetermined air pressure is equal to or greater than the threshold value tx, the process proceeds to S8. On the other hand, if S7 returns "NO," that is, if it is determined that the time it takes to drop to the predetermined air pressure is less than the threshold value tx, the process ends.

[0051] In S8, the control unit 61 issues a second warning from the operation unit 70. That is, when the control unit 61 determines that the user is on the second air cell 31b, it issues the second warning from the operation unit 70. The second warning is a warning with a lower level of urgency than the first warning. That is, when the user is on the second air cell 31b, it means that the user is sitting somewhat shallowly on the seat air mattress 30. Therefore, the operation unit 70 issues a second warning, such as a message such as "Please sit deeply" or a light different from the first warning is turned on, and the process ends.

[0052] In this way, the control unit 61 determines the user's position based on the elapsed time until the air pressure drops to a predetermined level when the first air cell 31a or the second air cell 31b is deflated. This allows the user's position to be detected without using a dedicated sensor to identify the user's position, thereby reducing costs. Furthermore, since the user's position can be properly determined, the user can use the wheelchair 100 and wheelchair air mattress 10 comfortably. Furthermore, the user can use the wheelchair 100 and wheelchair air mattress 10 safely. Furthermore, the caregiver can recognize the user's position by checking the operating unit 70. As a result, the wheelchair air mattress 10 is easy to use.

[0053] Furthermore, the control unit 61 determines whether or not a user is present on the second air cell 31b after determining whether or not a user is present on the first air cell 31a. This allows early detection of a user sitting shallowly on the seat air mattress 30, allowing the user to be more quickly corrected to an appropriate position.

[0054] In the above-described embodiment, the case where the process ends when S7 returns "NO" has been described as an example. However, the control unit 61 may determine whether or not a user is present on the third air cell 31c when S7 returns "NO." In this case, the control unit 61 may cause the operating unit 70 to notify that the user is seated on the third air cell 31c.

[0055] In the above embodiment, the case where it is determined whether or not a user is present on three of the six air cells 31 of the seat air mattress 30 has been described as an example. However, the present invention is not limited to this, and for example, user position detection may be performed sequentially for all (six) air cells. In this case, it is preferable that the control unit 61 perform user position determination sequentially, starting with the air cell 31 located at the front.

[0056] In the above-described embodiment, an example has been described in which the seated position of the user is detected when the wheelchair 100 and air mattress unit 20 are in the seated position. However, the present invention is not limited to this, and for example, the control unit 61 may detect the position of the user when the wheelchair 100 and air mattress unit 20 are in the bed position. Even when the user is in a lying position, the downward force from the vicinity of the buttocks (ischium) is large, so position detection can be performed.

[0057] In the above-described embodiment, the air mattress unit 20 has been described as having the seat air mattress 30, the back air mattress 40, and the leg air mattress 50. However, the present invention is not limited to this, and for example, the air mattress unit 20 does not have to have the back air mattress 40 and the leg air mattress 50.

[0058] Embodiments may include the following features. (Configuration 1) An air mattress that is placed on the seat of the wheelchair; a blower for supplying air to the seat air mattress; an electromagnetic valve unit located between the seat air mattress and the blower; an air pressure sensor for detecting the air pressure in the seat air mattress; a control unit that controls the operation of the blower unit and the operation of the solenoid valve unit; Equipped with The seat air mattress is A first air cell; a second air cell located behind the first air cell and having air intake and exhaust control different from that of the first air cell; and An air mattress for a wheelchair, characterized in that the control unit determines the user's position based on the elapsed time for the air pressure to drop to a predetermined level when air is released from the first air cell or the second air cell. (Configuration 2) The air mattress for a wheelchair described in configuration 1 is characterized in that the control unit determines whether a user is present on the first air cell and then determines whether a user is present on the second air cell. (Configuration 3) The seat air mattress further includes an operating unit for operating the internal pressure of the seat air mattress, 3. The air mattress for a wheelchair according to claim 1 or 2, wherein the control unit causes the operation unit to issue a warning based on the user's position.

[0059] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention described in the claims and their equivalents. [Explanation of symbols]

[0060] 10. Wheelchair air mattress 15 Cover 20 air mattress units 30 Seat air mattress 31 Air Cell 31a 1st Air Cell 31b Second air cell 31c 3rd Air Cell 32 bands 40 Back Air Mattress 41 Air Cell 42 bands 50 Leg Air Mattress 51 Air Cell 52 Upper air cell 53 Lower air cell 60 Pump Unit 61 Control Unit 61a Storage section 62 Solenoid valve unit 62a First solenoid valve 62b Second solenoid valve 62c Third solenoid valve 62d 4th solenoid valve 65 Blower 66 Air pressure sensor 67 Conduit 70 Operation section 75 Battery 76 Angle Sensor 80 tubes 90, 95 characteristic lines 100 wheelchairs 101 Seat part 102 Backrest 103 Footrest 110 Handle 120 Handrail H user

Claims

1. An air mattress that is placed on the seat of the wheelchair; a blower for supplying air to the seat air mattress; an electromagnetic valve unit located between the seat air mattress and the blower; an air pressure sensor for detecting the air pressure in the seat air mattress; a control unit that controls the operation of the blower unit and the operation of the solenoid valve unit; Equipped with The seat air mattress is A first air cell; a second air cell located behind the first air cell and having air intake and exhaust control different from that of the first air cell; and An air mattress for a wheelchair, characterized in that the control unit determines the user's position based on the elapsed time for the air pressure to drop to a predetermined level when the air is exhausted from the first air cell or the second air cell.

2. 2. The air mattress for a wheelchair according to claim 1, wherein the control unit determines whether a user is present on the first air cell and then determines whether a user is present on the second air cell.

3. The seat air mattress further includes an operating unit for operating the internal pressure of the seat air mattress, 3. The air mattress for a wheelchair according to claim 1, wherein the control unit issues a warning to the operation unit based on the user's position.

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