JPH0565177B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a cuff suitable for use in a blood pressure measuring device that measures blood pressure by indirect means.

[Prior Art] This type of blood pressure measuring device uses a cuff to intermittently pressurize a body part in a sawtooth wave pattern, detects a photoplethysmogram of a blood vessel passing through the pressurized part, and detects the photoplethysmogram. Some measure blood pressure based on wave signals and cuff pressure.

Conventionally, such indirect blood pressure measuring devices measure blood pressure on a finger, upper arm, etc., and the cuff that pressurizes the body part to be measured is a device into which a body part such as a finger is inserted. It had become a thing.

[Problems to be Solved by the Invention] However, since conventional blood pressure measuring devices measure blood pressure on fingers, upper arms, etc., it is not possible to use hands and arms freely when measuring blood pressure. In particular, when measuring blood pressure during exercise, it is important not to restrict the free movement of the whole body, and in this respect, the cuffs used in conventional blood pressure measurement devices are not suitable for measuring blood pressure during exercise. It was hot.

This invention was made in consideration of these circumstances, and even during various movements and movements,
Blood pressure can be measured without restricting body movements such as arms, and the cuff is thin and highly durable, providing even pressure evenly along the delicate unevenness of the head. The purpose is to provide

[Means for Solving the Problems] In order to solve the above-mentioned problems, the cuff of the present invention comprises: a bag made of two flat elastic plates facing each other and having their peripheral edges fixed to each other; and of the bag. It is characterized by comprising an outer frame that surrounds the peripheral edge and one side of the bag and exposes the other side of the inner bag.

[Operation] First, the outer frame is brought into close contact with the subject while the other side of the bag is facing the subject. When the bag is then inflated, the other side of the bag is exposed from the outer frame and presses against the subject. At this time, since the peripheral edge is surrounded by the outer frame, concentration of stress on the peripheral edge of the bag is prevented.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

In the figure, 1 is the head of a subject, and a cuff 2 is attached to a predetermined part of the head 1 with a belt 3.

As shown in FIGS. 2 and 3, the cuff 2 is attached to an annular stepped portion 2b of an annular pad 2a made of synthetic rubber.
Fit the transparent bag body 2c made of urethane rubber,
Thereafter, a synthetic rubber plate 2d is adhered to the upper surface of the pad 2a. Bag body 2c
This is made by heat-sealing the periphery of two circular sheets made of urethane rubber, and the inside is hollow. Further, a tube 2e that communicates with the hollow interior is attached to this bag body 2c, and the air pressure supplied to the inside of the bag body 2c through this tube 2e causes The bag body 2c bulges downward from the pad 2a and presses a predetermined portion of the head 1. Further, guide grooves 2f and 2g for guiding the tube 2e are formed in the pad 2a and the plate 2d.

Such a cuff 2 is attached to the head 1 by means of a belt 3.
The bag body 2c is placed on top of the superficial temporal artery, and the expansion of the bag body 2c compresses the superficial temporal artery. In this case, cuff 2
deforms to match the shape of the subject's head 1 and reliably compresses the superficial temporal artery. Further, in the belt 3, a pair of hook-and-loop fasteners 3a and 3b (see Fig. 4) are attached to the front surface near one end and the back surface near the other end, and by joining these, the belt 3 is attached to the head. It is designed so that it can be wrapped around 1.

On the lower surface of the plate 2d in the cuff 2, a second
As shown in the figure, a photoelectric sensor 5 consisting of a light emitting element (LED) 5a and a light receiving element 5b arranged facing each other is embedded and positioned so as to sandwich the superficial temporal artery of the head 1. The photoplethysmogram of the superficial temporal artery is detected. In the figure, L is a lead wire of the photoelectric sensor 5.

A heart position monitor 6 is attached to the subject's heart. This heart position monitor 6 is for correcting fluctuations in blood pressure caused by vertical movement of the head 1, and as shown in FIG.
A rubber cap 6b placed over the upper end of a, and a guard cap 6 for protecting the rubber cap 6b.
c, and a pressure sensor 6d connected to the lower end of the tube 6a. And tube 6
A pressure sensor 6d is attached so that the upper end of the tube 6a is at the position of the superficial temporal artery (measurement site) of the head 1 and the lower end of the tube 6a is at the heart position, and is connected to the lower end of the tube 6a. As a result, a pressure proportional to the height difference h between the superficial temporal artery at the measurement site and the heart is determined, and the resulting fluctuation in blood pressure value is corrected using the following equation. Note that if the superficial temporal artery at the measurement site is lower than the heart position, the above pressure becomes negative pressure.

Pr = P + h / 1.36 [mmHg] ... (1) where P is the blood pressure value obtained by measurement Pr is the true blood pressure value after correction In Fig. 1, 11 is the cuff for pumping air to cuff 2. This is a pressure reduction pump. This cuff pressurization/depressurization pump 11 has the ability to pressurize up to 300 mmHg in about 2 seconds, and is capable of controlling the initial pressure (for example, 40 mmHg) as appropriate. Air pressure (cuff pressure) P is detected by a pressure sensor 12, and its detection signal is sent to a cuff pressure sensor amplifier 13. The cuff pressure signal amplified by the cuff pressure sensor amplifier 13 is converted into a digital signal by the A/D converter 14 and supplied to the CPU 16 via the bus 15.

On the other hand, the output of the pressure sensor 6d, that is, the correction signal based on the position of the superficial temporal artery, is sent to the heart position detection sensor amplifier 17 and amplified, and then sent to the A/D
It is converted into a digital signal by converter 18 and supplied to CPU 16 via bus 15.

The light emitting element (LED) 5a is driven and lit by an LED drive circuit 19. The light emitted from the light emitting element 5a crosses the superficial temporal artery and is received by the light receiving element 5b. In this case, the amount of light received by the light receiving element 5b is proportional to the blood vessel volume of the superficial temporal artery, and the received light is photoelectrically converted and output from the light receiving element 5b as a so-called photoplethysmogram signal. This photoplethysmogram signal is amplified by a photoplethysmogram detection amplifier 20, then converted into a digital signal by an A/D converter 21, and supplied to the CPU 16 via a bus 15.

In addition, the cuff pressurization pump 11 and the LED
The drive circuit 19 is connected to the CPU 16 via an output I/O interface 22 and a bus 15.

Next, reference numeral 25 in FIG. 1 is an alarm setting device, which sets how far the average blood pressure value should fall to output an alarm. This alarm setting value is set by rotating a knob (not shown), and is set to, for example, 80 mmHg.
Further, reference numeral 26 denotes an interval setting device, which sets the interval of blood pressure measurement, that is, the driving interval of the cuff pressurization/depressurization pump 11. This measurement interval is set by rotating a knob (not shown), and is set to, for example, 1 to 2 minutes. These setting values are then supplied to the CPU 16 through the input I/O interface 27.
It is stored in RAM31.

The CPU 16 controls the cuff pressure/depressurization pump 11, calculates blood pressure values (average, maximum, and minimum blood pressure values) based on the photoplethysmogram signal and the cuff pressure, and calculates the average blood pressure based on the program stored in the ROM 30. It compares the value with the alarm setting value and controls the output of an alarm when the average blood pressure value falls below the alarm setting value, and the details of its operation will be described later.

Each blood pressure value calculated by the CPU 16 and the alarm signal output from the CPU 16 are sent to various monitor devices 36 such as an electrocardiogram monitor device, a display device 37, and a data memory device 38 via an output I/O interface 35. , alarm 39.

Next, the operation of this embodiment will be explained.

First, rotate the knob of the alarm setting device 25 to set the alarm setting value, that is, the lower limit value of the average blood pressure value, and also set the lower limit value of the average blood pressure value.
Rotate knob 6 to set the blood pressure measurement interval. In addition, the alarm setting value is, for example, 80mmHg,
The measurement interval is set to 1 minute, for example.

Under these settings, blood pressure measurement will begin,
Measurement start trigger signal output from CPU16
ST performs blood pressure measurements at regular time intervals.

FIG. 5 is a waveform diagram showing the operation for one blood pressure measurement, in which a shows the waveform of the trigger signal ST, b shows the waveform of the cuff pressure P, and c shows the waveform of the photoplethysmogram signal D. be.

As can be seen from this figure, the cuff pressurization/depressurization pump 11 is driven by the trigger signal ST through the output I/O interface 22 to supply air to the cuff 2 and to pump the subject's superficial temporal artery. Apply pressure.
In this case, prior to the start of measurement, the cuff pressure of about 40 mmHg is maintained for about 2 seconds, and the photoplethysmogram signal D is optimized.

Next, the cuff pressure increase/decrease pump 11 is driven again to increase the cuff pressure P to 200 mmHg. Once the cuff pressure P rises to the maximum value in this way, the cuff pressure P is lowered at a constant speed. Eventually, at the point where the cuff pressure P matches the systolic blood pressure, a photoplethysmogram signal D begins to appear. The amplitude of this photoplethysmogram signal D gradually increases and reaches its maximum amplitude at the mean blood pressure.

Therefore, the CPU 16 can determine the systolic blood pressure value and the average blood pressure value from the amplitude of the photoplethysmogram signal D and the cuff pressure P. That is, the photoplethysmogram signal D
is the systolic blood pressure value of cuff pressure P when appears,
The cuff pressure P when the amplitude of the photoplethysmogram signal D is maximum is the average blood pressure value.

In this case, it has already been explained that an error occurs in the blood pressure value due to the height difference h between the measurement site, that is, the superficial temporal artery and the heart position. The CPU 16 is A/
The value h is determined using the data supplied from the D converter 18, and the blood pressure measurement value is corrected by calculating the value h using equation (1).

Furthermore, the diastolic blood pressure value is calculated by performing a certain calculation on the systolic blood pressure value and the average blood pressure value. Furthermore, since the frequency of the photoplethysmogram signal D matches the heart rate, the CPU 16 can determine the heart rate. These data are displayed on the display 37.

In this way, the blood pressure value is measured every time the trigger signal ST is output at regular intervals. In addition,
The maximum value of cuff pressure P is 1 for the second and subsequent measurements.
The systolic blood pressure value calculated at the first visit + 30 mmHg.

In this way, blood pressure is measured at regular intervals within 1 to 2 minutes, and when the average blood pressure value falls below the alarm setting value, it is displayed on the display 36 and the alarm 3
7 is sounded.

Note that the photoelectric sensor 5 can be attached to the cuff 2 in any manner. For example, as shown in FIG.
The light-emitting element 5a and the light-receiving element 5b may be bonded to the lower surface of the bag body 2c while facing each other. Further, in this case, it is also possible to handle the light emitting element 5a and the light receiving element 5b separately from the cuff 2 without adhering them to the bag body 2c of the cuff 2. That is, the light emitting element 5a and the light receiving element 5b are attached to the head 1 so as to sandwich the superficial temporal artery of the head 1, and then the light emitting element 5a and the light receiving element 5b are attached to the head 1 so as to cover them.
The cuff 2 may be attached to the head 1 by a belt 3. In short, it is sufficient that the photoelectric sensor 5 can detect the photoplethysmogram.

Further, the method of attaching the cuff 2 that compresses the superficial temporal artery is arbitrary, and the heart position monitor 6 may be attached to the cuff 2 or the belt 3.

It is also possible to connect the cuff 2 to an indirect blood pressure measuring device using another measurement method, for example, an indirect blood pressure measuring device using a volume compensation method. The volume compensation method is a method that continuously detects changes in cuff pressure as changes in blood pressure by applying pressure to blood vessels using a cuff that corresponds to blood pressure pulsations so as to keep the volume of the blood vessels constant. and in this case,
The detection means attached to the cuff 2 will detect the blood vessel volume of the superficial temporal artery.

[Effects of the Invention] As explained above, according to the cuff of the present invention, the cuff as a whole can be constructed to be thin, so that it is possible to reduce the discomfort when worn on the subject's head or the like. Furthermore, since the periphery of the bag is protected by the outer frame, stress concentration on the periphery can be prevented, and high durability can be achieved even when the bag is made of soft material. be.

[Brief explanation of the drawing]

1 to 6 are diagrams for explaining one embodiment of the present invention, in which FIG. 1 is a block diagram, FIG. 2 is a sectional view of the cuff, and FIG. 3 is an exploded perspective view of the cuff. , Fig. 4 is a plan view of the cuff and belt, Fig. 5 is a waveform diagram to explain the operation during blood pressure measurement, and Fig. 6 is a sectional view of the cuff to explain a modification of how to attach the photoelectric sensor. It is. 1... Head, 2... Cuff, 2a... Pad (outer frame), 2b... Annular step, 2c... Bag body, 2d...
...Plate (outer frame), 2e...Tube, 2f,
2g... Guide groove, 5... Photoelectric sensor (detection means), 5a... Light emitting element, 5b... Light receiving element, 1
1... Cuff pressurization/depressurization pump (pressurizing means), 16...
…CPU.

Claims (1)

[Scope of Claims] 1. A bag made of two flat elastic plates facing each other and having their peripheral edges fixed to each other; A cuff characterized by comprising an outer frame that exposes the other side of the bag body.