JP2657923B2 - Automatic blood pressure measurement device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic blood pressure measurement device that automatically measures the blood pressure of a human body using a pump device that compresses and pressurizes a gas.

[Conventional technology]

In general, the measurement of blood pressure has been performed by medical staff such as doctors using a mercury column and a stethoscope connected to a manual pump. However, the demand for measuring blood pressure at home has been increasing due to the recent development of medical technology and recognition of wishing to improve the health of the nation, and automatic blood pressure measuring devices that can measure blood pressure with simple operations have become widespread.

FIG. 9 is a configuration diagram of a conventional automatic blood pressure measurement device. In the drawing, reference numeral 10 denotes a pressurizing pump device including a DC motor 10a and a pressurizing mechanism unit 10b that discharges high-pressure air by rotation of the DC motor, and 30 denotes air pressurized by the pressurizing pump device 10 to each unit. Pressurized piping to be sent, 40 is an arm band to be attached to the upper arm of the subject when measuring blood pressure and compresses blood vessels, 50 is an arm band
40 is a pressure sensor for detecting the pressure, 60 is a fine exhaust valve for gradually discharging the pressurized air accumulated in the arm band 40, and 70 is a rapid exhaust valve for rapidly discharging the pressurized air remaining in the arm band 40 after the end of the blood pressure measurement. Exhaust. A control unit 80 controls the activation of the pressurizing pump device 10 and adjusts the pressure in the arm band 40, calculates a blood pressure value based on a signal from the pressure sensor 50 obtained by the adjustment, and displays a display unit 90. To be displayed.

Now, the procedure for measuring blood pressure with this automatic blood pressure monitor will be described.
This will be described with reference to the characteristic diagram shown in FIG. First, the arm band 40 is attached to the upper arm of the person to be measured, and the pressure band device 40 pressurizes the arm band 40. Next, sufficient pressure for example 250mmHg for arm band 40 after a time T ₁ is to measure the "systolic blood pressure" in the upper arm
Reaches (point P), the controller 80 stops the pressurizing pump 10. The fine exhaust valve 60 has the shape of a small hole,
When 10 stops, pressurized air is gradually discharged to lower the pressure inside the arm band 40. And, for example, a pressure of 150 mmHg (point H)
At this time, when the pressure sensor 50 detects that the blood in the upper arm has begun to flow, the control unit 80 determines that the pressure at this time is “systolic blood pressure”. Further, the pressure of the arm band 40 decreases, for example, the pressure
When the pressure sensor 50 detects the pulsation of the blood at 90 mmHg (point L), the control unit 80 determines that the pressure at this time is “diastolic blood pressure”. In this way, when the blood pressure measurement is completed,
70 is opened to release all the pressurized air remaining in the cuff 40 (point C), and the display section 90 displays “systolic blood pressure 150” and “diastolic blood pressure 9”.
Displays "0".

The procedure for measuring the blood pressure follows the procedure performed by a doctor or the like with a manual pump and a stethoscope as it is,
Although there is no problem in principle, in the conventional procedure, the initial pressure of the arm band 40 must be increased to 250 mmHg in a short time as shown in FIG. 10 in order to measure `` systolic blood pressure '' first, and as a result, This causes the power consumption of the pressurized pump device to increase. In addition, the necessity of the minute exhaust valve 60 required a complicated structure.

For this reason, an improved procedure has been proposed as shown in the characteristic diagram of FIG. That is, the pressure on the cuff 40 is gradually increased, and when blood pulsation stops (point L), the pressure is determined to be “diastolic blood pressure”, and the pressure on the cuff 40 is further increased. When the flow rises (point H), the "systolic blood pressure"
Judge. Then, after measuring the "systolic blood pressure" of the subject, the quick exhaust valve is opened to discharge the pressurized air of the arm band 40 (point C). With such a procedure, there is no procedure for gradually discharging the pressurized air, so not only is the fine exhaust valve 60 unknown but also the arm band
There is no need to raise the initial pressure of 40 to 250 mmHg in a short time, which is superior to the procedure described above in this respect.

[Problems to be solved by the invention]

However, in the procedure described with reference to FIG. 11, while the pressurizing pump device
(Point L) and the "systolic blood pressure" (point H) are measured, the pressure sensor 50 measuring the blood pressure value mistakes the pulsation of the blood and the pulsation of the air pressurized by the pressurizing pump device 10. There is a danger that accurate blood pressure measurement cannot be expected.

[Means for solving the problem]

In order to solve the above-mentioned problem, the present invention provides a volume-invariant pressure regulator having a sufficiently long narrow path communicating with the discharge port of the pressure mechanism, and one or more pressure chambers in the middle of the narrow path. Have.

[Action]

The pulsation of the pressurized air generated when pressurizing with the pressurizing pump device is removed by the pressurizing regulator.

〔Example〕

Hereinafter, examples will be described. FIG. 1 is a block diagram showing an embodiment according to the present invention. In the figure, the same parts as those in FIG. 9 are denoted by the same reference numerals. Reference numeral 20 denotes a pressure regulator for removing the pulsation of the pressurized air. Figure 2 shows the pressure regulator 20
1A is a front view, and FIG. 1B is a side view. In the figure, 21 is a suction side container, 22 is packing, and 23 is a discharge side container having the same structure as the suction side container 21. The pressure regulator 20 is composed of these three main components. A bolt 24 and a nut 25 are arranged so that the containers 21 and 23 on both sides of the packing 22 sandwich the packing regulator 22.
And has concluded. Arrow A indicates the direction in which air sent from the pressure pump device 10 is sucked, and arrow B indicates the direction in which air is discharged. FIG. 3 is an assembly view of components of the pressure regulator 20. In the figure, 21a is a suction port, 21b is a concave portion, 21c is a groove portion, 22b is a flow port of a packing 22 formed with the same diameter as the concave portion 21b, 21d, 22d, 23d are through holes for passing bolts 24, 21e is This is a recess connected to the suction port 21a.
As described above, since the suction side container 21 and the discharge side container 23 have the same structure, the discharge port 23a, the concave portion 23b, the groove 23c, the discharge Exit 23
A concave portion 23e connected to a is formed. 4 (a) is a plan view of the suction side container 21 as viewed from the symbol C in FIG. 3, and FIG. 4 (b) is a cross-sectional view taken along the line IVB-IVB in FIG. In FIG. 9A, the groove 21c is bent and arranged so as to obtain a sufficient distance from the recess 21e to the recess 21b. The groove 21c has a small groove cross section as shown in FIG. 2B, whereas the recess 21b and the recess 21e have a large cross section (volume). FIG. 5 is FIG. 2 (a)
FIG. In the figure, the groove 21c of the suction side container 21 faces the packing 22 so that the recess 2c is formed.
A narrow path is formed from 1e to the recess 21b (referred to as a first narrow path). Similarly, the recess 21e faces the packing 22 to form a pressure chamber (referred to as a first pressure chamber).
The pressure chamber 21b is connected to the recess 23b through the flow port 22b to form a pressure chamber having two volumes of the recess 21b and the recess 23b (second
Pressure chamber). Furthermore, a groove in the discharge side container 23
23c also forms a narrow path from the concave part 23b to the concave part 23e as described above (referred to as a second narrow path), and the concave part 23e also forms a pressure chamber (referred to as a third pressure chamber).

Next, the operation will be described. In the configuration of FIG.
When blood pressure measurement is performed according to the procedure described with reference to FIG. 11, first, the control unit 80 starts the pressurizing pump device 10. Next, the air pressurized from the pressurizing pump device 10 is supplied to the inlet of the pressurizing regulator 20.
Supplied to 21a. The supplied pressurized air is sent to the first pressure chamber formed by the recess 21e as shown in the block diagram of FIG. This first pressure chamber accumulates the supplied pressurized air and prevents the flow rate of the pressurized air from decreasing when passing through the next first narrow path. In addition, the effect of accumulating pulsating energy when accumulating pressurized air is generated,
Smoothes the energy of the pulsation. Next, the pulsation of the pressurized air sent into the first narrow path is attenuated by the narrow path having high air resistance. Then, the pressurized air in which the pulsation has attenuated is sent to the second pressurized chamber formed by the concave portions 21b and 23b.
Since the capacity of the pressure chamber is sufficiently larger than that of the first narrow path, even if the supplied pressurized air has pulsation that cannot be removed by the first pressure chamber, the pulsating energy can be accumulated. As a result, the energy of the pulsation is smoothed again. Further, the compressed air passes through the second narrow path having the same structure as the first narrow path, so that the compressed air from which the pulsation has been substantially removed is sent to the third pressure chamber. The third pressure chamber is the second pressure chamber.
The same operation as that of the pressure chamber of the above is performed, and the pressure of the pressurized air supplied to the arm band 40 is stabilized. As described above, the pressure regulator 20 completely eliminates the pulsation of the pressurized air supplied from the pressure pump device 10. The basic principle of this operation is similar to a muffler of an automobile or the like.

Therefore, since the pulsation-removed pressurized air is supplied to the pressure sensor 50 and other components, the "diastolic blood pressure" (point L) and the "systolic blood pressure" (point H) described in FIG. 11 are measured. In, the blood pressure and the pulsation of the pressurized air are not mistakenly recognized by the pressure sensor 50, and accurate blood pressure measurement can be performed.

Further, by connecting the pressure regulator 20 to the pressure pump device 10, a constant flow rate characteristic as shown in the characteristic diagram of FIG. 7 can be expected. That is, as described above, the pressure regulator 20
Since it is composed of two narrow passages and a pressure chamber, even if the air resistance is high and the pressure is increased by increasing the voltage of the pressure pump device 10, a certain amount of pressurized air passes through the pressure regulator 20. Is limited to For example, the characteristic “a” of the pressurizing pump device 10 when the pressurizing regulator 20 is not attached indicates that the flow rate increases linearly as the pump voltage increases. On the other hand, the characteristics b, c, and d when the pressure regulator 20 is attached indicate that the first pressure chamber rises to the maximum pressure of the pressure pump device 10 as soon as the pump voltage is increased. For each flow rate 1 of characteristic a,
1 / 2,1 / 3,1 / 5. This means that a substantially constant flow rate can be obtained even when the working voltage value fluctuates in the working voltage range, and this characteristic enables stable blood pressure measurement. Further, by changing the shape of the narrow passage and the volume of the pressure chamber, a desired flow rate required for blood pressure measurement can be selected from the characteristics b, c, and d, and the degree of freedom in design can be secured.

In the above-described embodiment, the case where the pressurizing pump device 10 and the pressurizing regulator 20 are separate bodies is shown. However, as shown in the sectional view of FIG. In the figure, the same or corresponding parts as in FIG. 3 are denoted by the same reference numerals. Reference numeral 10c denotes an electric wire of a DC motor, and reference numeral 26 denotes packing that prevents air leakage when pressurized air is supplied from the pressurizing mechanism 10b to the suction side container 21.

〔The invention's effect〕

As described above, the present invention provides a volume-invariant pressure regulator having a narrow path disposed sufficiently long at the discharge port of the pressurizing mechanism and one or more pressure chambers in the middle of the narrow path. As a result, the pulsation of pressurized air can be eliminated, and when used in an automatic blood pressure measurement device, the pressure sensor can accurately measure blood pressure without erroneously recognizing pulsation of blood and pulsation of pressurized air. Become. Further, since a constant flow rate characteristic is obtained in the working voltage range of the pressurizing pump device, a stable blood pressure value can be measured even if the pump voltage fluctuates during blood pressure measurement.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment in which the present invention is used in an automatic blood pressure monitor, FIG. 2 (a) is a front view of a pressure regulator, FIG. 2 (b) is a side view thereof, and FIG. Fig. 4 (a) is a plan view of the suction side container 21 as viewed from the symbol c in Fig. 3, and Fig. 4 (b) is an IVB of Fig. 3 (a).
FIG. 5 is a cross-sectional view taken along the line VV in FIG.
6 is a block diagram showing the flow of pressurized air, FIG. 7 is a characteristic diagram of flow rate and pump voltage, FIG. 8 is a partial sectional view of the pressurized pump device, and FIG. 9 is a conventional pressurized pump device. Is used in an automatic blood pressure monitor, FIG. 10 is a conventional pressure-time characteristic diagram, and FIG. 11 is a proposed pressure-time characteristic diagram. 10 ... Pressure pump device, 10a… DC motor, 10b… Pressure mechanism, 20… Pressure adjustment unit, 30… Pressure piping, 40…
Arm band, 50 ... Pressure sensor, 70 ... Sudden valve, 80 ... Control unit, 90 ... Display unit.

Claims (1)

(57) [Claims] A pressurizing pump device comprising a motor and a pressurizing mechanism for discharging high-pressure gas by rotation of the motor; a sufficiently long narrow path communicating with a discharge port of the pressurizing mechanism; A pressure regulator having an invariable volume having one or more pressure chambers in the middle thereof, and a cuff for accumulating pressurized air sent from the pressure regulator, and pressurized by the pressure regulator. An automatic blood pressure measurement device characterized by sufficiently reducing the intrinsic capacity of the pump device, eliminating pulsation, and providing a constant flow characteristic with respect to the pump voltage.