JPH0348822B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field to which the Invention Pertains] The present invention relates to a fluidized bed in which a bed is formed by fluidized fine particles by a leached air flow leached above a diffuser plate through a compressor. Furthermore, the present invention relates to a control device for varying the body surface pressure between the floor and the human body, or in other words, the "bed hardness" in a floating bed in which the human body is suspended and supported.

[Prior art and its problems]

The general structure and operation of this type of fluid bed will be explained in the first part.
This will be explained using Figure A. Note that in the following figures, the same reference numerals indicate the same or corresponding parts. In Fig. 1A, 1 is a ring compressor that pressurizes the external air AO, 1a is a motor that drives the ring compressor 1, and HC is a motor that cools the compressed air whose temperature has increased due to being pressurized by the ring compressor 1. F is a fan that sends air for heat exchange to the heat exchanger HC, and 2 is a fan that sends pressurized air A1 led through the air duct D to the day user board 3. It is a sealed chamber that opens on the bottom. The day user board 3 is a plate-shaped body made of a porous material, and the pressurized air A1 in the sealed chamber 2 is leached upward from a large number of thin gaps distributed over the entire board surface as air A2. , leached and diffused. Reference numeral 5 denotes a bed formed of fine particles such as beads that are made to flow by the leaching air A2, and is hereinafter referred to as a bead bed. 4 is a tank that accommodates the bead bed 5 and the day user board 3 and is integrated with the sealed chamber 2; S is a cloth sheet that covers the upper surface of the bead bed and has holes with a mesh smaller than that of the beads; While allowing the beads to pass through, it also prevents the beads from dispersing into the air, and can also be used in place of gauze or bandages when in contact with the human body.

These fluid beds prevent blood circulation disorders caused by localized pressure on the human body, so they have traditionally been used mainly to promote skin regeneration in patients with severe burns and to prevent pressure ulcers (so-called bedsores) in patients who have been bedridden for a long time. When the patient is placed on the bead bed 5 through the sheet S, the patient's entire body is supported by almost uniform pressure, and therefore the body surface pressure to support the body weight is maintained. Since pressure on the skin can be kept to a minimum, pressure on the skin is also less uneven, and blood circulation disorders due to pressure on peripheral blood vessels can be prevented.

FIG. 1B shows an example of floating support for a human body in this fluidized bed. Human body BH is a flowing bead bed 5
The patient is suspended and supported in a submerged manner as deep as possible to the extent that it does not interfere with treatment. For example, the equivalent specific gravity of the flowing bead bed 5 is approximately 1.29, and the human body sinks approximately as shown in the figure. Therefore, the human body BH is supported by the bead bed 5 over a correspondingly wider contact area, and the human body sinks as shown in the figure. Body surface pressure can be lowered.

As described above, the purpose of conventional fluid beds is to keep the pressure on the patient's body surface exerted by the fluid beads at a constant value that is as low as possible and almost uniform, like a "fluffy" futon, for example. However, with this method alone, it is not possible to change the futon from a fluffy one to a moderately firm one depending on the patient's recovery level or the doctor's stage of treatment, and on the other hand, it is not possible to change the futon from a fluffy one to a moderately firm one, depending on the patient's level of recovery or the doctor's stage of treatment. The problem is that they cannot meet the demands.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a control device for arbitrarily varying the hardness of a flowing bead bed.

[Key points of the invention]

The main point of the present invention is that the pressurized air A1 in the sealed chamber 2
The flow rate of the leaching air A2 by varying the pressure of and thus the equivalent specific gravity of the flowing bead bed 5,
The feature is that the body surface pressure, that is, the hardness of the bead bed, can be varied by varying the depth to which the human body sinks or the contact area between the bead bed 5 and the human body.

[Embodiments of the invention]

Next, embodiments of the present invention will be described using FIGS. 2 to 6.

FIG. 2 shows that the pressure P of pressurized air A1 in the sealed chamber 2 is controlled by varying the air flow rate by varying the opening degree of the throttle valve 11 provided at the air suction port 1b of the ring compressor 1. Here is an example of 1
2 is a pressure sensor that detects the pressure P; 13 is a pressure setting device; 14 is a pressure adjustment/control device; 15 is an actuator that operates the opening degree of the throttle valve 11;
16 is a pressure indicator that displays the pressure P, and 17 is a converter that amplifies and converts the pressure detection signal ei of the pressure sensor 12 and supplies it to the pressure indicator 16. That is, the pressure adjustment/control device 14 compares the pressure detection signal ei of the pressure sensor 12 and the pressure setting signal es of the pressure setting device 13, and performs an adjustment operation such as PI (D) operation on the difference between these signals. Later actuator 1
By converting and amplifying the signal to drive the ring compressor 1 and operating the actuator 15, the opening degree of the throttle valve 11 is varied, and the external air
The flow rate of the suction air of the AO is varied and controlled so that the pressure P in the sealed chamber 2 is always the pressure set by the pressure setting device 13.

FIG. 6 shows an example of the relationship between the opening diameter corresponding to the opening degree of the throttle valve 11 and the equivalent specific gravity of the bead bed 5. That is, as the opening diameter decreases, the flow rate of the suction air and hence the pressure P in the sealed chamber 2 decreases, and correspondingly, the flow rate of the leached air A2 leached from the day user board 3 also decreases, and the flow of beads decreases. decreases, and the equivalent specific gravity of the bead bed 5 increases. By variably adjusting the opening degree of the throttle valve 11 and the pressure P in the sealed chamber 2 in this manner, the equivalent specific gravity and thus the "hardness" of the bead bed 5 can be varied.

FIG. 3 shows an example in which the pressure P in the sealed chamber 2 is controlled by varying the rotational speed of the ring compressor 1, and 21 is a speed control device that controls the speed of the blower motor 1a of the ring compressor 1. . That is, the pressure regulator 14A compares the pressure detection signal ei and the pressure setting signal es, performs adjustment calculation,
The output is given as the speed setting signal eo as the speed setting value of the speed control device 21, and the pressure P is controlled to be the pressure set by the pressure setting device 13 through such speed control of the blower motor 1a.

The above is an example of controlling the pressure P in a closed loop, but in many cases the pressure P does not require high precision in practice, so it may also be controlled in an open loop. An example of open-loop manual control is shown below. FIG. 4 shows a system in which the opening degree of the throttle valve 11A is variably adjusted using a manual pressure setting device 15A. In this case, the pressure indicator 16 is not necessarily required if the value of the pressure P is directly calibrated as the setting scale of the manual pressure setting device.

Furthermore, in FIG. 5, the speed setting signal eo to be given to the speed control device 21 is given from a manual speed setting device 22. In this case as well, if the setting scale of the speed setting device 22 is directly changed to the value of pressure P, Pressure indicator 16 is not essential.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, it is possible to obtain a futon made of fluid beads having the hardness desired by a doctor or patient at any time, and the therapeutic effect can be further enhanced.

Furthermore, this invention makes it possible to use the fluidized bed not only for medical purposes but also as a health device for the elderly and even normal people.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of a conventional fluid bed, Figure 2~
FIG. 5 is a block diagram showing an embodiment of the fluidized bed according to the present invention, and FIG. 6 is an explanatory diagram illustrating the relationship between the pressure inside the closed chamber and the hardness of the bead bed. Symbol explanation, 1: Ring compressor, 1b: Air suction port, 1a: Blower motor, 2: Sealed chamber,
3: Day user board, 5: Beads, 11,1
1A: Throttle valve, 12: Pressure sensor, 13: Pressure setting device, 14: Pressure adjustment control device, 14A: Pressure regulator, 15: Actuator, 15A: Manual pressure setting device, 21: Speed control device, 22: Speed setting vessel.

Claims (1)

[Claims] 1. Pressurized air is leached upward from a diffusion plate that has a large number of pores on the plate surface, and a human body is suspended and supported on a floor formed of granules that are fluidized by the leached air flow obtained by this leaching. The flow bed configured as described above includes a pressure sensor that detects the pressure of the pressurized air and outputs a pressure detection signal, and a pressure setting device that sets the pressure and outputs a pressure setting signal, A fluid bed characterized in that a pressure variable means for varying the pressure of the human body is provided, and the body surface pressure between the bed and the human body is varied by varying the pressure of pressurized air by the pressure variable means. Hardness control device.