JPH048882Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to an improvement in an automatic switching valve device for a blood pressure monitor that automatically switches between supplying fluid to the cuff of the blood pressure monitor and discharging fluid from within the cuff. It is.

Prior Art During the pressure increase or decrease process of a cuff wrapped around a part of a living body, a pressure sensor detects an oscillating component of the cuff pressure, that is, a pulse wave, which changes in size as the cuff pressure changes, or BACKGROUND ART A type of sphygmomanometer that automatically measures a living body's blood pressure based on detecting the occurrence and disappearance of Korotkoff sounds using a microphone has been proposed. One type of blood pressure monitor is one in which an automatic switching valve device comprising an electromagnetic switching valve is provided between the pressure source and the cuff. In this automatic switching valve device, normally, depending on the operating state of the electromagnetic switching valve, there are two states: supplying fluid from the pressure source to the cuff, and blocking the supply of fluid to the cuff and discharging fluid from within the cuff. It is designed to be able to be selectively switched between two states.

Problems to be Solved by the Invention However, in such an automatic switching valve device, in order to maintain the two states, the electromagnetic switching valve must normally be continuously energized in one of the two states. First, there was a problem that a relatively large amount of electric power was required.

Means for Solving the Problems The present invention was developed against the background of the above circumstances, and its gist is to supply fluid from a pressure source to a cuff and to supply fluid from inside the cuff to the atmosphere. (a) a spool provided with a pair of pressure-receiving surfaces that are movable in the axial direction, have the same pressure-receiving area, and face in opposite directions; (b) a pair of pressure chambers each connected to the pressure source and applying pressure to the pair of pressure receiving surfaces of the spool, and (c) each provided between the pair of pressure chambers and the pressure source. (d) a pair of electromagnetic opening/closing devices each connected to the pair of pressure chambers, which prevent exhaustion of pressure from the pressure chamber when in a non-energized state, but exhaust pressure from the pressure chamber when in an energized state; and a valve.

By doing this, when a pair of electromagnetic switching valves connected to a pair of pressure chambers are both in a de-energized state, the pressure of the pressure source is applied to both pressure chambers, but the pressure of the electromagnetic switching valve is When one of the pressure chambers is energized, a throttle device is provided between the pressure chamber and the pressure source to allow exhaust pressure in one of the pressure chambers. As a result, the spool is moved toward one of the pressure chambers, and the switching valve device is switched to a predetermined state. At this time, since the pair of pressure-receiving surfaces facing opposite to each other on the spool are formed to have the same pressure-receiving area, even if the one electromagnetic switching valve is in a de-energized state after the movement of the spool is completed, the spool is The position is maintained.

Effects of the invention As a result, when switching, there is no need to directly drive the spool, and the relatively small electromagnetic on-off valve can be energized only when the automatic switching valve device is switched, so it requires less power than before. Consumption can be significantly reduced. This has the effect of greatly increasing the battery life, especially in portable blood pressure monitors.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.

FIG. 1 is a diagram showing the main parts of a blood pressure monitor equipped with an automatic switching valve device to which the present invention is applied, and 10 is a switching valve. The switching valve 1 includes a casing 12 and a spool 1 fitted inside the casing 12 so as to be movable in the axial direction.
A pair of pressure chambers 16 and 18 are formed between both ends of the spool 14 and the casing 12, and a pair of pressure receiving surfaces 20 and 22 of this spool 14 have the same pressure receiving area. It is formed by The casing 12 has eight ports 24, 26, 28, 30, 32, 34, 36,
38 are provided in sequence. Port 24, 38
are connected to the pressure cylinder 40 (pressure source) and opened to the pressure chambers 16 and 18, respectively, and the cross-sectional area near the openings on the pressure chambers 16 and 18 side is small over a predetermined length. The constricted portions 25 and 27 are formed by this. In this embodiment, these diaphragm sections 25 and 27 function as a diaphragm device. As a result, the pressure chambers 16,1
8 is supplied with high pressure (e.g. 20Kg/
cm ² ) can be applied. The port 26 is connected to the pressure cylinder 40 via a pressure reducing valve 42.
The port 28 is connected to the cuff 50 via the flow rate adjustment device 29 and ports 46 and 48 of the exhaust valve 44, respectively. Ports 30 and 32 are each open to the atmosphere, and port 34
is connected to port 52 of exhaust valve 44. Further, the port 36, together with the ports 24 and 38, is connected to a pressure cylinder 40, so that high pressure is supplied thereto. The flow rate adjustment device 29 is
For example, the patent application filed earlier by the applicant in 1983-
It is configured almost the same as the automatic control valve device described in No. 74574, and includes a pressure reducing valve 42, a port 26,
Low pressure (e.g. 3.5Kg/
The pressure within the cuff 50 is increased at a predetermined rate so that the blood pressure can be measured during the pressurization process by adjusting the flow rate of the fluid (approximately cm ² ). Note that this flow rate adjustment device 29 is not directly necessary for understanding the present invention, so a detailed explanation thereof will be omitted. When high pressure is applied to the port 52 of the exhaust valve 44, a movable member 54 disposed inside the exhaust valve 44 is moved against the biasing force of a spring 56, and the exhaust port 58 is closed. This allows the pressure inside the cuff 50 to increase due to the low pressure, while the movable member 54 is allowed to rise when the high pressure to the port 52 is released.
is pushed back according to the biasing force of the spring 56, and the exhaust port 58 is opened, thereby rapidly evacuating the inside of the cuff 50.

The housing 12 further includes a pressure chamber 16,
a pair of exhaust ports 60 each opening at 18;
62 are provided, and these exhaust ports 60,
Connected to 62 are relatively small electromagnetic on-off valves 64 and 66 that are configured similarly to each other. When the electromagnetic on-off valves 64 and 66 are in a non-energized state, the movable member 68 is pressed by a spring 70 and the port 7 is closed.
However, in the energized state, the movable member 68 is moved in a direction away from the port 72 (to the right in FIG. 1) against the urging force of the spring 70, and the port 72 is prevented from communicating with the port 74. and the port 74 are communicated with each other. As a result, the inside of the pressure chamber 16 or 18 is opened to the atmosphere by selectively energizing both the electromagnetic on-off valves 64 and 66.

In the automatic switching valve device configured as described above, when the switching valve 10 is in the state shown in FIG. While high pressure is applied, ports 26 and 28
Communication with port 36 and port 3 is blocked, and fluid supply to cuff 50 is blocked.
4 and the port 52 of the exhaust valve 44 is blocked.
No high pressure is applied to the exhaust port 58, and the exhaust port 58 is in an open state. Next, when one of the solenoid valves 66 is energized and its ports 72 and 74 are communicated, the port 38
Since the constriction portion 27 is formed in the pressure chamber 18, the pressure inside the pressure chamber 18 is exhausted. As a result, the spool 14
is moved toward the pressure chamber 18 and the switching valve 1
0 is switched to the state shown in FIG. In this state, communication between the port 34 and the port 32 is blocked and the port 34 and the port 36 are allowed to communicate with each other, so that high pressure is applied to the port 52 of the exhaust valve 44 and the exhaust port 58 is closed. At the same time, the communication between the ports 28 and 30 is blocked, and the ports 26 and 28 are allowed to communicate with each other, thereby starting the supply of fluid from the pressure cylinder 40 into the cuff 50. During the period of increasing the pressure of the cuff 50, the diastolic blood pressure, systolic blood pressure, etc. are sequentially determined by a measuring circuit (not shown).

Here, since the pressure receiving areas of the respective pressure receiving surfaces 20 and 22 of the spool 14 are formed to be the same, after the electromagnetic on-off valve 66 is energized and the movement of the spool 14 is completed as described above, the electromagnetic Even if the on-off valve 66 is de-energized and high pressure is applied to the pressure chamber 18 again, the spool 14
is not moved, and the switching state of the switching valve 10 is maintained. When the measurement of the systolic blood pressure is completed, the pressure inside the pressure chamber 16 is exhausted by energizing the electromagnetic on-off valve 64 connected to the port 60 in FIG. is switched to the state shown in FIG. 1 in which fluid supply is blocked, and port 52 is switched to port 3
4 and the exhaust port 5 through the port 32.
8 is in the open state, the pressure inside the cuff 50 is rapidly exhausted. In this case as well, the electromagnetic on-off valve 64
Even if the switching valve 10 is placed in a de-energized state immediately after the movement of the spool 14 is completed, the switching state of the switching valve 10 is maintained. As a result, when switching the switching valve 10 to a predetermined state, there is no need to directly drive the spool 14, and moreover, both relatively small electromagnetic on-off valves 64, 66
Since it is only necessary to momentarily excite one of the two, power consumption can be significantly reduced compared to conventional methods. This has the effect of significantly increasing battery life, especially in portable blood pressure monitors.

Further, according to this embodiment, even during the blood pressure lowering process of the cuff 50, the measurement of the systolic blood pressure is completed and the switching valve 10
When the state is switched to the state shown in FIG. 1, the exhaust port 58 of the exhaust valve 44 is opened and the pressure inside the cuff 50 is rapidly exhausted, so that no pressure is applied to the upper arm of the subject. may be canceled promptly.

Further, according to this embodiment, only when switching the switching valve 10, the electromagnetic on-off valves 64, 6
6 is open and the fluid is discharged to the atmosphere, which has the advantage of saving fluid consumption.

In addition, in the above-mentioned embodiment, blood pressure measurement is performed during the pressurization process of the cuff 50, but
The blood pressure may be measured during the pressure reduction process of the cuff 50 by omitting the flow rate adjustment device 29, the exhaust valve 44, etc., and connecting a predetermined throttle device to the port 30.

Further, in the above-mentioned embodiment, the port 24,
A constriction part 2 is provided at each opening of the 38 pressure chambers 16 and 18.
5 and 27 are formed, but this is not necessarily necessary; for example, the ports 24 and 38 may be formed with a diameter sufficiently smaller than the inner diameter of the piping connected to the ports 24 and 38 over their entire length. It is okay to do so.

Furthermore, in the embodiment described above, the switching valve 10 has a pair of ports 24 and 3 provided in the housing 12.
Although pressure is applied to the pressure chambers 16 and 18 from the pressure chambers 16 and 18 through the constricted portions 25 and 27 formed therein, it is not necessary to configure them in this manner, for example, as shown in FIG. As shown in FIG.
A pair of constricted parts 80 having a diameter smaller than that of the hole 78 are fixed at both ends in the axial direction, and a portion of the hole 78 that opens into the outer peripheral surface serves as a pressure source regardless of the position of the spool 76. It may also be configured to communicate with the port 82 connected to. Note that the port 84 is connected to the cuff, and the port 86 is open to the atmosphere. Also in this case, the pair of pressure receiving surfaces 8 of the spool 76
8 and 90 with the same pressure receiving area, and an exhaust port 9 that opens into a pair of pressure chambers 92 and 94.
The effects of the present invention can be obtained by connecting electromagnetic on-off valves similar to those in the above-described embodiment to 6 and 98, respectively.

In addition, various changes may be made to the present invention without departing from the spirit thereof.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the main parts of a blood pressure monitor equipped with an automatic switching valve device to which the present invention is applied. FIG. 2 is a diagram showing another switching state of the switching valve shown in FIG. 1. FIG. 3 is a diagram showing a main part of another application example of the present invention, and corresponds to the switching valve in FIG. 1. 14,76...Spool, 16,18,92,
94... Pressure chamber, 20, 22, 88, 90... Pressure receiving surface, 25, 27... Throttle part, 40... Pressure cylinder, 50... Cuff, 64, 66... Solenoid on-off valve,
80...Aperture member.

Claims (1)

[Claims for Utility Model Registration] In a sphygmomanometer that measures the blood pressure of a living body based on pressure changes in a cuff wrapped around a part of the living body, a state in which fluid is supplied from a pressure source to the cuff; An automatic switching valve device that can be switched to a state where the fluid is discharged from inside the cuff to the atmosphere, which is movable in the axial direction and has a pair of pressure receiving surfaces having the same pressure receiving area and facing oppositely. a pair of pressure chambers that are respectively connected to the pressure source and apply pressure to the pair of pressure receiving surfaces of the spool, and a pair of pressure chambers that are respectively provided between the pair of pressure chambers and the pressure source. a throttle device, and a pair of electromagnetic on-off valves each connected to the pair of pressure chambers to prevent exhaust pressure from the pressure chamber when in a non-energized state, but to exhaust pressure from the pressure chamber when in an energized state. An automatic switching valve device for a blood pressure monitor, comprising: