JP5683445B2 - Mattress and its switching valve failure detection method - Google Patents

Description

  The present invention relates to a mattress that can detect a failure of a switching valve that switches supply / exhaust of air to and from an air bag by a pump and prevent abnormal expansion of a cell, and a switching valve failure detection method thereof.

  2. Description of the Related Art Conventionally, an air mattress composed of cells that expand by air pressure is known. The air mattress is used as a body pressure dispersion bedding or the like, and is useful as a bedding that prevents the body pressure of a patient lying on the mattress from concentrating and prevents bed slippage in the patient's body.

  For example, in Patent Document 1, a first system cell group and a second system cell group formed by a plurality of tubular cells and arranged alternately, an air supply pipe connected to each cell group, and an air supply pipe An air mat comprising an air switching valve for alternately supplying and exhausting air, a pump for sending air to the air switching valve, and a pressure sensor installed in the middle of the air tube immediately before the air switching valve is described . Based on the value of the pressure sensor, the pressure change in the air mat is suppressed by controlling the strength of the air switching valve and the pump.

Japanese Patent Laid-Open No. 11-46934

The pump continues to supply air. By opening and closing the switching valve, the air in the cell and the air from the pump are released to the atmosphere, and the air from the pump is supplied to the cell to control the supply and exhaust. .
However, if the switching valve fails and the switching operation cannot be performed during exhaust, there is a possibility that air will continue to be supplied to the cell and cause abnormal expansion. Although abnormal expansion can be detected by the pressure sensor, in the case of detecting a failure with only the pressure value, the pressure value itself does not increase significantly due to plastic deformation of the cell, but the cell may continue to expand. Therefore, even if the pressure threshold for abnormal inflation is determined and detected, detection is not possible unless the abnormal inflation has progressed to some extent, and the patient may be in an abnormal posture.
Further, if a switching valve that has a position sensor inside the switching valve and can check whether the valve is opened or closed can be used to detect the failure of the valve, it is very expensive.

  In view of such circumstances, the present invention intends to provide a mattress capable of detecting a failure of a switching valve early using a pressure sensor used for pressure detection to a cell and a switching valve failure detection method thereof. is there.

  The present invention includes a cell, a pressure sensor that detects an internal pressure of the cell, a pump connected to adjust the air amount of the cell, a communication path that communicates from the pump to the cell, A switching valve interposed on a communication path between a cell and the pump and capable of switching between at least a state in which the cell and the pump are in communication with each other and a state in which the cell is opened to an atmospheric pressure; and the pressure A failure detection unit that obtains a pressure increase value per unit time in the internal pressure of the cell from a sensor value, and detects the failure of the switching valve by comparing the pressure increase value with a failure threshold value. It is a mattress.

  The present invention is further characterized by further comprising a pump control unit that stops the pump when the failure detection unit determines that the switching valve has a failure.

  Further, the present invention is characterized in that the pressure increase value is obtained from a time from when the switching valve is switched to start exhaust or pressure maintenance from the cell and a change in pressure increase therebetween.

The present invention also includes a cell, a pressure sensor that detects an internal pressure of the cell, a pump connected to adjust the air amount of the cell, and a communication path that communicates from the pump to the cell. A switching valve interposed on a communication path between the cell and the pump and capable of switching between a state where at least the cell and the pump communicate with each other and a state where the cell is opened to atmospheric pressure; In the switching valve failure detection method used for the mattress having
A pressure increase value per unit time in the internal pressure of the cell is obtained from a value of the pressure sensor, and the pressure increase value compares a failure threshold value to detect a failure of the switching valve.

According to the present invention, the failure of the switching valve can be detected before abnormal expansion by measuring the increase in the internal pressure of the cell per unit time using the pressure sensor that measures the internal pressure of the cell. Moreover, since it is not necessary to newly provide a special sensor using a pressure sensor that measures the internal pressure of the cell, it is possible to achieve an excellent effect that a failure of the switching valve can be detected with an inexpensive and compact structure.
Further, since the pump is stopped by detecting the failure of the switching valve, abnormal expansion can be prevented in advance.
In addition, since the pressure increase value per unit time is determined by the time from when the switching valve is switched and the exhaust or pressure maintenance from the cell is started, a failure of the switching valve can be detected immediately, and abnormal expansion Can be prevented in advance.

It is a figure for demonstrating the outline of the bed apparatus in this embodiment. It is the figure which represented the bed apparatus from the leg side front. It is a figure for demonstrating each cell of the bed apparatus in this embodiment. It is a figure for demonstrating operation | movement of the switching valve in this embodiment. It is a figure for demonstrating operation | movement of the switching valve in this embodiment. It is a figure for demonstrating operation | movement of the switching valve in this embodiment. It is a block diagram for demonstrating the function structure of the bed apparatus in this embodiment. It is a flowchart for demonstrating the operation | movement process of the bed apparatus of this embodiment.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

[1. Overall configuration diagram]
[1.1 Device outline]
First, the configuration of the entire bed apparatus to which the present invention is applied will be described with reference to FIGS. 1 and 2. FIG. 1 is a diagram for explaining an outline of the bed apparatus 1 in the present embodiment. FIG. 2 is a diagram illustrating the bed apparatus 1 from the front side on the foot side (the control unit 40 side in FIG. 1).

  In the bed apparatus 1, the mat body 10 is placed on a base 30. Here, the mat body 10 includes a plurality of cells 14 arranged continuously in the longitudinal direction. The mat body 10 is configured by being covered with a cover 12 including a top cover and a bottom cover.

  The bed apparatus 1 includes a rolling unit 20. The rolling unit 20 includes a side cell 22 and a rolling cell 24, and is used for changing the posture of the patient.

  Here, the bed apparatus 1 is used so that the patient's foot side is in the F direction in FIG. 1 (the control unit 40 side) and the head side is in the H direction in FIG. Therefore, the right side of the patient is the R direction in FIG. 1, and the left side is the L direction in FIG.

  The side cell 22 includes a side cell 22R on the right side and a side cell 22L on the left side. The rolling cell 24 is composed of a rolling cell 24R on the right side and a rolling cell 24L on the left side.

  A blower tube 42 is connected to each cell (cell 14, side cell 22, rolling cell 24) from the control unit 40. A blower tube 44 is connected to the control unit 40 from the pump 50. Further, the control unit 40 and the pump 50 are connected by a control cable 52, and various control signals are exchanged. The pump 50 is connected to a control cable 54 from the outside, and is connected to a power cable 56 for driving the pump.

  Each cell 14 is divided into a plurality of sets of systems and connected to a common blower tube 42 as a communication path. The blower tube 42 is connected to the switching valve via a blower tube connection connector, and the switch valve is connected to the pump 50 via the blower tube. The cells 50 are supplied and exhausted by the operation of the pump 50 and the switching valve. This switching valve uses a solenoid valve, but may be a rotary valve type.

  Similarly to the air supply / exhaust operation of each cell 14, the side cell 22 and the rolling cell 24 are also connected to the blower tube 42 and are connected to the switching valve via the blower tube 42. And the switching valve is connected to the pump 50 via the ventilation tube 44, and air supply / exhaust is performed.

  In addition, the structure may be such that one is output from the blower tube 42 and the pump 50 that are communication paths and is branched and input to each cell, or a plurality of outputs may be output from the pump 50. That is, it is sufficient if the pressure value of each cell is the same when the operation of communicating each cell is performed.

[1.2 Explanation of each cell configuration]
Next, the configuration of each cell (cell 14, side cell 22 and rolling cell 24) will be described with reference to FIG. As shown in FIG. 3, the side cell 22 is a system S, the rolling cell is a system R (the rolling cell L is a system R (L), the rolling cell R is a system R (R)), and the pump 50 is connected to the pump 50 via a switching valve. It is connected.

  Further, each cell is connected to the pump 50 separately from the system A to the system G. For example, the cell 14A is connected to the blower tube 42A as the system A. The cells 14A belonging to the system A are uniformly supplied and exhausted by the blower tube 42A.

[1.3 Operation of switching valve]
Subsequently, the operation of the switching valve will be described with reference to FIGS. The operation of the switching valve will be described as an example in which three cell systems are connected for convenience of explanation.

  In the figure, a cell system 1 (14a), a cell system 2 (14b), and a cell system 3 (14c) are shown. Each cell system is connected to a blower tube as a communication path from the pump 50, and can supply and exhaust air (air) into the cell.

  In addition, a switching valve is connected to each cell system. The switching valve has, for example, a valve body constituted by a plunger, a switching valve (valve body) connected to the pump side, and a switching valve (valve body) for releasing the air of the cell system to the atmosphere. And have. Specifically, a switching valve 60a connected to the pump and a switching valve 62a for opening to atmospheric pressure are connected to the cell system 1 (14a). The cell system 2 (14b) has a switching valve 60b connected to the pump and a switching valve 62b for opening to atmospheric pressure, and the cell system 3 (14c) has a switching valve connected to the pump. 60c and a switching valve 62c for opening to atmospheric pressure are connected to each other.

  The switching valve connected to each cell system may have a switching valve, or may be configured by a single switching valve. That is, in one switching valve, the valve body may be operated so as to switch between a state of being connected to the pump side and being able to supply and exhaust air, a state of being able to exhaust to atmospheric pressure, and a state of sealing the cells, depending on the open / close state of the valve body .

  Furthermore, a pressure sensor is connected between the switching valve and the cell system. A pressure sensor 150a is connected to the cell system 1 (14a), a pressure sensor 150b is connected to the cell system 2 (14b), and a pressure sensor 150c is connected to the cell system 3 (14c). This pressure sensor can detect the internal pressure of the connected cell (system).

  The pump 50 is provided with a switching valve 64. Therefore, for example, by opening the switching valve 64 and driving the pump and opening the switching valve 60a to switching valve 60c, air can be supplied to the cell systems 1 to 3. Moreover, if the switching valve 60a-switching valve 60c is closed and switching valve 62a-62c is opened, exhaust will be possible from the cell systems 1-3. By individually controlling the opening and closing of these switching valves, the supply and exhaust of the cell systems 1 to 3 can be individually controlled.

  Here, the operation of the present embodiment will be described with reference to the drawings. First, FIG. 4 shows a state in which all the switching valves are closed. At this time, each cell system has its own pressure. An example in which the pump 50 is driven from this state to open and close the switching valve to control the supply and exhaust of the cell systems 1 to 3 individually is shown in FIGS.

  In FIG. 5, the switching valves 60a, 60b, 62c, 64 are opened, the switching valves 62a, 62b, 60c are closed, air is supplied to the cell systems 1, 2, and the cell system 3 is exhausted.

Next, in FIG. 6, the switching valves 60b, 60c, and 64 are opened, the switching valves 60a, 62a, 62b, and 62c are closed, air is supplied to the cell systems 2 and 3, and the cell system 1 is left as it is. State.
At this time, if the switching valve 60a remains open due to a failure, the air supply continues to be performed, and the cell system 1 undergoes abnormal expansion. In the present invention, the abnormal expansion of the cell system 1 is detected by the pressure sensor 150a to stop the pump.

  FIGS. 4 to 6 illustrate the abnormal expansion of the cell system 1 taking the case of the failure of the switching valve 60a as an example, assuming that there are three cell systems for convenience of explanation, but for detecting the failure of the switching valve in one or more cells. Can also be used.

[2. Functional configuration]
Next, the functional configuration of the bed apparatus 1 will be described with reference to FIG. As shown in FIG. 7, in the bed apparatus 1, a state detection unit 110, a storage unit 120, a pressure sensor 150, and a pump control unit 160 are connected to the CPU 100.

  A CPU (Central Process Unit) 100 is a functional unit for controlling the entire bed apparatus 1. The CPU 100 realizes various functions by reading and executing various programs stored in the storage unit 120.

  The state detection unit 110 is a functional unit for detecting various states in the bed apparatus 1. For example, the state is detected by detecting the state of the pressure sensor or detecting the operation signal of the actuator. Here, as a state to be detected, various states can be detected, for example, a back-up angle of a bed, a foot-down angle, a patient's weight, or a patient's bed state. Is possible. In addition, a pressure increase value per unit time in the internal pressure of the cell is obtained from the detection value of the pressure sensor 150, and the pressure increase value also functions as a failure detection unit that detects a failure of the switching valve by comparing a failure threshold value. .

  The storage unit 120 is a functional unit that stores various programs and various data necessary for the operation of the bed apparatus 1. The storage unit 120 includes, for example, a semiconductor memory, an HDD (Hard Disk Drive), or the like.

  In addition, the storage unit 120 stores a setting table 122. The setting table is a table in which the specified internal pressure value of each cell (cell 14, side cell 22 and rolling cell 24) in the bed apparatus 1 and a failure threshold value for detecting a failure of the switching valve are stored.

  The pressure sensor 150 is a functional unit for detecting the pressure of each cell, and includes a pressure sensor or the like. The pressure sensor 150 is connected to each switching valve (for each cell system) via a blower tube connector. The pressure of each cell is detected by the pressure sensor 150.

  The pump control unit 160 is a functional unit for controlling the pump 50. By operating and stopping the pump 50, air supply / exhaust control can be realized.

  The switching valve control unit 170 is a functional unit that controls the switching valve connected to each cell system and the switching valve connected to the pump 50. By controlling the switching valve, air can be supplied or exhausted together with the operation of the pump 50. In addition, control for holding air in each cell is performed.

  The operation display unit 180 is an input unit for a user (for example, a patient, a care recipient, a care staff, or the like) to instruct the bed apparatus 1 to perform an operation, and the state of the bed apparatus 1 to the user. It is a functional part for reporting. For example, it may be composed of a liquid crystal screen having a touch panel or a hardware key.

[3. Process flow]
Next, the flow of processing will be described with reference to the drawings. FIG. 8 shows a process for detecting a failure of the switching valve by the pressure sensor and preventing abnormal expansion of the cell in the present embodiment. In this processing, it is assumed that the pump 50 is in operation according to an instruction from the pump control unit 160 and the cell is exhausted or the state of the cell is maintained by opening and closing the switching valve according to an instruction from the switching valve control unit 170. .

  First, in response to an instruction from the switching valve control unit 170, the switching valve performs an opening / closing operation to start forced exhausting or maintaining the state of the cell (step S11). The internal pressure is measured by the pressure sensor 150 connected to each cell system, and the state detection unit 110 calculates the pressure increase per unit time from the start of the switching valve opening / closing control, and determines whether or not the failure threshold is exceeded. (Step S12). The measurement time of the pressure sensor is about 1 to 5 seconds after the switching operation of the switching valve, and the pressure increase value per unit time is calculated from the increase in the internal pressure of the cell at that time. The failure threshold is desirably set to 1 kPa or more. Since these values vary depending on the size and material of each cell and the capacity of the pump, they are set in advance and stored in the setting table 122 of the storage unit 120.

When the pressure sensor 150 has a pressure increase value per unit time less than the failure threshold (step S12; No), the internal pressure of the cell is stored in the setting table 122, assuming that there is no abnormality in the switching valve. The operation is continued until the value is reached (step S13).
When it becomes more than a failure threshold value (step S12; Yes), it determines that the switching valve has failed, and the pump control part 160 stops the pump 50 immediately (step S14).

  Thus, by detecting the failure of the switching valve based on the pressure increase value per unit time of the cell internal pressure, the failure of the switching valve can be detected before the cell causes abnormal expansion. Even if the failure point of the switching valve cannot be specified, the pump is stopped immediately, so that abnormal expansion of the cell can be prevented. Further, since the pressure increase value per unit time is obtained from the time from when the switching valve is switched and the exhaust from the cell or the maintenance of the pressure is started, a failure of the switching valve can be detected immediately. In this way, abnormal cell expansion can be prevented.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and the design and the like within the scope of the present invention are also within the scope of the claims. include.
For example, in the above-described embodiment, an example in which the air cell is divided into a plurality of parts (an example in which a cell close to the center is divided into an upper side and a lower side) has been described. May be.

1 Bed device 10 Mat body 12 Cover 14 Cell 14a, 14b, 14c Cell system 20 Rolling part 22, 22L, 22R Side cell 24, 24L, 24R Rolling cell 30 Base 40 Control part 42, 44 Blowing tube 50 Pump 52 Control cable 54 Control Cable 56 Power cable 60a, 60b, 60c, 62a, 62b, 62c, 64 Switching valve 100 CPU
110 State detector (failure detector)
DESCRIPTION OF SYMBOLS 120 Memory | storage part 122 Setting table 150, 150a, 150b, 150c Pressure sensor 160 Pump control part 170 Switching valve control part 180 Operation display part

Claims (4)

Cell,
A pressure sensor for detecting the internal pressure of the cell;
A pump connected to regulate the amount of air in the cell;
A communication path communicating from the pump to the cell;
A switching valve interposed on a communication path between the cell and the pump and capable of switching between a state in which the cell and the pump are in communication with each other and a state in which the cell is opened to atmospheric pressure;
From the value of the pressure sensor, obtain a pressure increase value per unit time in the internal pressure of the cell, the pressure increase value compares a failure threshold, and detects a failure of the switching valve,
A mattress characterized by comprising:   The mattress according to claim 1, further comprising a pump control unit that stops the pump when the failure detection unit determines that the switching valve has a failure.   3. The mattress according to claim 1, wherein the pressure increase value per unit time is obtained by a time from when the switching valve is switched to start exhaust or pressure maintenance from the cell. A cell, a pressure sensor for detecting an internal pressure of the cell, a pump connected to adjust the air amount of the cell, a communication path communicating from the pump to the cell, the cell and the pump Is used in a mattress having a switching valve that can be switched between a state in which at least the cell and the pump are in communication with each other and a state in which the cell is opened to atmospheric pressure. In the switching valve failure detection method,
A switching valve failure characterized in that a pressure increase value per unit time in the internal pressure of the cell is obtained from a value of the pressure sensor, and the pressure increase value compares a failure threshold value to detect a failure of the switching valve. Detection method.

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