JP2994269B2 - Sphygmomanometer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sphygmomanometer in which fluctuations in cuff pressure are suppressed, and more particularly to a sphygmomanometer suitable for exercise load.

[0002]

2. Description of the Related Art A conventional sphygmomanometer merely supplies pressurized air from a cuff pressure pressurizing means such as a pressurizing pump to an air tube. For this reason, in the conventional blood pressure monitor, it was necessary to be at rest during blood pressure measurement. When the subject moved, the pressure in the cuff fluctuated due to the movement, and accurate blood pressure measurement could not be performed.

[0003]

However, as recently attracting attention, various methods for imposing an exercise load test on a patient or the like and performing various diagnoses have appeared.
In the field of sphygmomanometer, the appearance of a sphygmomanometer capable of accurately measuring blood pressure during exercise load has been awaited.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has as its object to provide a sphygmomanometer capable of measuring blood pressure even during an exercise load test. And For example, the following configuration is provided as one means for achieving such an object. That is, a cuff for compressing a blood vessel, a pressurizing pump for supplying air to the cuff, and a damper mechanism including an air chamber whose volume increases when the inflow pressure increases and decreases when the inflow pressure decreases. An air tube connecting the pressurizing pump, the cuff, and an air chamber of the damper mechanism, wherein the damper mechanism is divided into two chambers by a diaphragm whose shape is deformed by an inflow pressure, and the first chamber is divided into two chambers. The air chamber is provided, and the second chamber is set to a substantially constant pressure state, and a pressing means for pressing the diaphragm from the second chamber toward the first chamber at a constant pressure is provided.

[0005] For example, the diaphragm of the damper mechanism is formed of a flexible rubber-based material. Alternatively, the pressing means presses the diaphragm from the second chamber toward the first chamber by an elastic force of a spring.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. In this example, a cuff, a pressure pump for supplying air to the cuff, a damper mechanism that increases the volume of the air chamber when the inflow pressure increases, and reduces the volume of the air chamber when the inflow pressure decreases, A pressure monitor is provided with a pressurizing pump, an air tube connecting the cuff and the damper mechanism, and a fluctuation in the cuff pressure is absorbed by the damper mechanism, thereby providing a blood pressure monitor with a small fluctuation in the cuff pressure.

Hereinafter, the structure of the above-described damper mechanism according to an embodiment of the present invention will be described in detail with reference to FIGS. FIG. 1 is a diagram showing a state before pressurization of the damper mechanism of this embodiment, and FIG. 2 is a diagram showing an equilibrium state after pressurization of the damper mechanism of this embodiment. 1 and 2, reference numeral 1 denotes a case, 1a denotes a case of the first chamber, and 1b denotes a case of the second chamber. Reference numeral 2 denotes a port for taking in air into the first chamber 7, and reference numeral 3 denotes a diaphragm which is deformed by pressure. In this embodiment, the diaphragm is formed of a rubber-based material to have flexibility. At the joint of the second chamber case 1b and the first chamber case 1a, a concave portion is formed over the entire circumference, and the outer peripheral end of the diaphragm 3 enters into the concave portion, and the pressing member (O) is in this state. The ring (1c) is fitted and the second chamber case (1b) and the diaphragm (3) are fixed.

Reference numeral 4 denotes a plate for holding down the diaphragm 3;
Is a set screw for fixing the diaphragm 3 and the plate 4 to each other, and 6 is a diaphragm screw 3 against the air pressure in the first chamber.
Is pressed in the first chamber direction with a constant elastic force. The spring 6 includes a spring engaging projection 4a having an outer diameter substantially equal to the inner diameter of the spring 6 formed on the plate 4, and the second chamber case 1b. Locked between the bottom and the bottom.

Reference numeral 7 denotes a first chamber and 8 denotes a second chamber. A hole 9 is provided at the bottom of the second chamber 8, and the second chamber is maintained at an air pressure substantially equal to the atmospheric pressure. It is configured to: On the other hand, the inside of the first chamber 7 is configured to have the air pressure of the air passage connected to the port 2. FIG. 3 is a diagram showing a configuration of a sphygmomanometer having the damper mechanism shown in FIG. 1 of the present embodiment.

In FIG. 3, reference numeral 10 denotes a damper according to the embodiment of the present invention shown in FIGS. 1 and 2, reference numeral 11 denotes a cuff for pressing a blood vessel at a blood pressure measurement site, and reference numeral 12 denotes a blood pressure measurement blood vessel in the cuff 11. This is a K sound sensor that collects blood vessel sounds positioned so as to be positioned at the upper position, and is configured by, for example, a microphone, and detects Korotkoff sounds (hereinafter, referred to as “K sounds”) from the blood vessel sounds from the K sound sensor 12. It is for.

Reference numeral 13 denotes an air tube (air chamber), which is an air passage connecting the respective components of the air system to be described later, and reference numeral 14 denotes a pressure sensor, and electric parameters change according to the pressure in the cuff 11. Reference numeral 15 denotes a pressurizing pump for sending air to the cuff 11 to press the measurement site of the living body, 16 denotes a solenoid valve for exhausting to rapidly reduce the pressure in the cuff 11, and 17 measures a blood pressure value after pressurization. This is a pressure reducing valve for reducing the cuff pressure by evacuating the cuff pressure by a constant amount, for example, evacuating and reducing the pressure at 2-3 mmHg / sec.

Reference numeral 18 denotes a K-sound amplifier for amplifying the electric signal detected by the K-sound sensor 18, and 19 detects an electric parameter of the pressure sensor 14 which changes in accordance with a change in the cuff pressure. A pressure amplifier 20 converts and amplifies and outputs the analog electric signal from the K sound amplifier 18 and the pressure amplifier 19 to a corresponding signal and outputs A.
It is a D converter. The CPU 22 reads the digital information from the AD converter 20 and calculates a blood pressure measurement result.

Reference numeral 21 denotes a drive unit for driving the pressurizing pump 15, the exhaust electromagnetic valve 16, and the pressure reducing valve 17. Also, 2
Reference numeral 2 denotes a CPU for calculation and control configured by a single chip that controls the entire blood pressure monitor of the present embodiment in accordance with a control procedure stored in a ROM 23. Reference numeral 23 denotes a control procedure of the CPU 22, various parameters for blood pressure measurement, and the like. A read-only memory (ROM) 24 for storing a random access memory (RAM) for storing the processing progress of the CPU 22 and measurement results;
Reference numeral 25 denotes a display for displaying measurement guidance, a measurement result, a state of the apparatus, and the like.

In the above description, the blood pressure is measured by detecting, for example, Korotkoff sound (K sound) by the K sound sensor 12 provided in the cuff 11, but the present invention is limited to the above example. Instead, the blood pressure may be measured by detecting a pulsation sound with the K sound sensor 12, and the pulsation may be measured with the pressure sensor 14 by utilizing the fact that the pressure of the cuff 11 changes due to pulsation or the like. May be configured to measure the blood pressure by detecting a change in pressure caused by the pressure. Further, a configuration may be adopted in which pulsating, for example, arterial blood flow is irradiated with light by an LED or the like, and reflected light of light due to arterial blood flow is detected by a phototransistor or the like, thereby detecting a change in intravascular capacity and measuring blood pressure. Good. The blood pressure measurement method according to the present invention,
Any method can be used, and the method is not limited in any way.

In the above configuration, when the CPU 22 completes the mounting of the cuff 11 on the subject and completes the preparation for blood pressure measurement and inputs a measurement start instruction to the drive unit 21, the CPU 22 controls the exhaust electromagnetic valve 16. Then, the exhaust from the pressure reducing valve 17 is stopped, the pressurizing pump 15 is started, air is sent to the air tube 13, air is sent to the cuff 11 and the damper 10, and the cuff pressure and the first air chamber 7 of the damper 10 are sent. Increase air pressure. After that, the pressure reducing valve 17 is controlled by a known method to start reducing the pressure, and using the detection signals from the K sound sensor 12 and the pressure sensor 14, the K sound is detected from the K sound sensor 12 after the start of the pressure reduction. The absence state continues for a while, and then when the K sound is detected, the cuff pressure at that time becomes the systolic blood pressure value. For this reason, the blood pressure value is calculated and obtained by the CPU 22, and the result is displayed on the display 25 as the systolic blood pressure value.

If the CPU 22 immediately detects the K sound at the end of the pressurization, it is highly likely that the pressurization is insufficient. Therefore, the CPU 22 further drives the pressurizing pump 15 by a certain amount to increase the cuff pressure. And then measure blood pressure. After detecting the systolic blood pressure value, the CPU 22 further reduces the pressure, calculates the cuff pressure when the K sound is no longer detected, and displays the cuff pressure on the display 25 as the diastolic blood pressure value. Since the blood pressure measurement has been completed, the drive unit 21 is instructed to operate the exhaust solenoid valve 16 to release the pressure of the cuff 11 and the blood pressure measurement is completed.

In the above process, it is assumed that when the cuff pressure is increased to measure the blood pressure, the pressure in the cuff 11 fluctuates due to movement of the subject or the like. In this case, if the damper 10 of the present example is not provided, a change in the pressure in the cuff 11 is directly detected as a change in the pressure detected by the pressure sensor 14. The state of this pressure change is indicated by A in FIG. As a result, accurate blood pressure measurement cannot be performed, and the measured blood pressure value becomes unreliable.

In general, in order to prevent the fluctuation of the cuff pressure, when the volume of the whole air system is large, the influence of the fluctuation at a certain position is diluted, and the detection portion of the sensor such as the pressure sensor 14 or the like is reduced. The effect can be reduced. For this reason, it is conceivable to provide a large-sized air chamber separately from the cuff. However, if a large air chamber is provided, the influence of fluctuations in each pressure can be reduced, but the volume of air that must be pressurized by the pressurizing pump 15 also increases, requiring a lot of time for pressurization, and power consumption. And the exhaust takes time, and the burden on the measurer must be greatly increased. Also, the size of the device is increased.

For this reason, a battery-driven sphygmomanometer or a portable sphygmomanometer to be worn on the body cannot be provided with a separate large-volume air chamber. On the other hand, when the damper 10 shown in FIGS. 1 and 2 is provided, an apparent effect of increasing the mass of the air chamber can be obtained, and the influence of the pressure fluctuation of the air system can be reduced without providing the large-capacity air chamber. It can be minimized.

That is, in the damper 10 of the present embodiment, when the pressurizing pump 15 is not driven and pressurized air is not applied from the port 2 in an exhausted state (for example, the first chamber 7 and the second chamber 8). In the case where both are equal to the atmospheric pressure), the state shown in FIG. 1 is obtained, and the diaphragm 3 is deformed in the upper direction of the first chamber case 1a by the elastic force (spring force) of the spring 6.

When the pressurizing pump 15 is started to start the pressurizing operation from the state shown in FIG. 1, the cuff 11 is pressurized, and pressurized air is injected into the first chamber 7 from the port 2 and the first chamber 7 is opened. Pressure rises. As a result, the diaphragm 3 gradually deforms in the direction of the second chamber 8 against the elastic force of the spring 6. At this time, the pressure in the first chamber 7 is balanced with the pressure (atmospheric pressure) in the second chamber and the elastic force from the spring 6. FIG. 2 shows a state where the air pressure in the first chamber is sufficiently increased.

In this case, for example, when the subject wearing the cuff 11 moves due to body movement, the pressure of the air system fluctuates. Then, when the pressure is going to increase, the air flows into the first air chamber 7 from the port 2. At this time, in the damper 10 of this example,
When the pressure increases, the spring 6 contracts, the diaphragm 3 expands, and the volume of the air chamber increases, which acts to reduce the pressure.

Conversely, when the pressure is about to drop, the air in the first chamber flows out of the port 2 to the air tube 13. At this time, in the damper 10 of this example, when the pressure is going to decrease, the spring 6 is extended,
The diaphragm 3 shrinks to reduce the volume of the air chamber, and acts to increase the pressure. By acting in this way, it works to stabilize the pressure when the pressure is about to change rapidly. As a result, even with a small air chamber volume,
Due to the deformation of the spring 6 and the diaphragm 3, the same operation and effect as those of the air chamber having a very large air volume can be obtained.
Fluctuations in pressure can be kept low.

For example, when the spring 6 of the damper 10 is set to have a spring constant of about 200 g / mm and the maximum volume of the first air chamber 7 is set to 150 cc, for example, a good damper action can be obtained in a range of 50 mmHg at minimum and 280 mmHg at maximum. Can be obtained. In the above description, an example in which the diaphragm 3 is pressed in the first chamber direction by the spring 6 has been described. However, the present invention is not limited to the above example. The first chamber and the second chamber may be connected by an air path, and all or a part of the first and second chambers may be configured as a thin passage having air resistance. Also in this case, by appropriately designing the air resistance of the passage, the pressure fluctuation of the cuff and the like can be reduced.

As described above, according to the embodiment of the present invention, when the pressure of the cuff 11 fluctuates suddenly due to body movement, the pressure of the first chamber 7 also fluctuates, but the diaphragm 3 is deformed. As a result, the volume of the air chamber (first chamber 7) changes, and pressure fluctuation can be suppressed to a small value. For this reason, by using the sphygmomanometer of this example, for example, blood pressure measurement during exercise load, which could not be accurately measured in the past, can be performed more accurately than in the past. Fluctuations and the like can be measured.

FIG. 4B shows an example of the effect of suppressing the fluctuation of the cuff pressure when the damper 10 according to this embodiment is provided. The effect of providing the damper 10 is clear as compared with the example shown in A where the damper 10 is not provided.

[0027]

As described above, according to the present invention, even when the cuff pressure changes rapidly due to body movement, etc.
The effect of the fluctuation can be minimized by the action of the damper mechanism, and highly reliable measurement results can be obtained even in the measurement of blood pressure in an environment where body movement occurs during exercise load tests etc. Can be.

Further, by forming the diaphragm of the damper mechanism from a flexible rubber-based material, the processing performance can be improved, the cost can be reduced, and the airtightness can be improved. Furthermore,
By configuring the diaphragm to be pressed by the elastic force of the spring, the same pressure fluctuation suppression effect as when a large air chamber volume is provided with a small air chamber volume can be achieved, and the mechanism can be simplified. , A small and inexpensive damper mechanism.

[Brief description of the drawings]

FIG. 1 is a diagram showing a state before pressurization of a damper according to an example of an embodiment of the present invention.

FIG. 2 is a diagram showing a state after pressurization of a damper according to an example of an embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a sphygmomanometer having the damper mechanism shown in FIG. 1 of the present embodiment.

FIG. 4 is a diagram for explaining a state of fluctuation of the pressure in the cuff.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Case 1a Case of 1st chamber 1b Case of 2nd chamber 1c Pressing member (O-ring) 2 Port 3 Diaphragm 4 Plate 5 Set screw 6 Spring 4a Spring locking convex part 7 First room 8 Second room 9 Hole 10 Damper Reference Signs List 11 cuff 12 K sound sensor 13 air tube (air chamber) 14 pressure sensor 15 pressurizing pump 16 exhaust solenoid valve 17 pressure reducing valve 18 K sound amplifier 19 pressure amplifier 20 AD converter 21 drive unit 22 CPU 23 read-only memory (ROM) ) 24 Random access memory (RAM) 25 Display

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshimi Seshita 2-3-3, Shiba-koen, Minato-ku, Tokyo Inside Walbro Japan Co., Ltd. (72) Inventor Hitoshi Fujisawa 2-3-3, Shiba-koen, Minato-ku, Tokyo No. In Japan Walbro Co., Ltd. (58) Field surveyed (Int.Cl. ⁶ , DB name) A61B 5/00-5/03

Claims (3)

(57) [Claims] 1. A cuff for compressing a blood vessel, a pressurizing pump for supplying air to the cuff, and an air chamber whose volume increases when the inflow pressure increases and decreases when the inflow pressure decreases. A damper mechanism; and an air tube connecting the pressurizing pump, the cuff, and an air chamber of the damper mechanism, wherein the damper mechanism is divided into two chambers by a diaphragm whose shape is deformed by an inflow pressure. A sphygmomanometer, comprising: a pressure chamber, wherein the chamber is the air chamber, the pressure of the second chamber is substantially constant, and pressure means for pressing the diaphragm from the second chamber toward the first chamber at a constant pressure. 2. The sphygmomanometer according to claim 1, wherein the diaphragm of the damper mechanism is formed of a flexible rubber-based material. 3. The sphygmomanometer according to claim 1, wherein the pressing means presses the diaphragm from the second chamber toward the first chamber by an elastic force of a spring.