JPS5855777B2 - Pressure control device in blood pressure measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressurization control device in a blood pressure measuring device.

Equipped with a pressure detector that detects the pressure of a pressure system including a cuff (a rubber bag wrapped around the arm), and a Korotkoff sound detector that collects pulse sounds and extracts Korotkoff sound signals from the pulse sounds signals, In a blood pressure measuring device that automatically measures systolic and diastolic blood pressure based on the outputs of both these detectors, air is automatically supplied to the pressure system to increase the pressure to the required pressure value, and then gradually reduce the pressure. There is something to do.

However, since systolic blood pressure differs depending on the person to be measured, if the maximum pressurization value is fixed, if the systolic blood pressure is high (in this case, the systolic blood pressure may not be measured due to insufficient pressurization).

Therefore, in order to pressurize to the optimum pressure, there is a pressurizing device that first pressurizes to the required pressurization value, determines whether the pressurization is insufficient, and if the pressurization is insufficient, pressurizes further (
For example, Japanese Patent Publication No. 50-2549).

According to this device, it is certainly convenient to be able to automatically pressurize the person to be measured (to the optimum pressure), but after pressurizing to the required pressure value, it is determined whether or not the pressurization is insufficient. If pressurization is insufficient, pressurization is continued to one level higher, which increases the time it takes to apply pressure and increases the pressure on the arteries that are already tense due to the initial pressurization. This may not only cause congestion and errors in blood pressure measurements, but may also have a negative impact on the subject's body.

This invention was made in view of the above circumstances, and
A blood pressure measuring device that automatically supplies air to the pressure system to pressurize it can pressurize it to the optimal value depending on the person being measured, and it also avoids errors in blood pressure measurement like with conventional devices. To provide a pressurization control device that does not pose a risk of adversely affecting people.

The pressurization control device according to the present invention includes a pressurizing pump that supplies air and pressurizes a pressure system including a manchet, a pressure detector that detects the pressure of the pressure system, a pressure detector that collects pulse sounds, and uses Korotkov's A Korotkoff sound detector that extracts a sound signal, a coincidence detection means that detects that the pressure detected by the pressure detector matches a predetermined pressurization value after the pressure pump is activated, and stops the operation of the pressure pump; and this coincidence detection. Pressure shortage detection means detects insufficient pressurization by outputting a Korotkoff sound signal from a Korotkoff sound detector when pressure coincidence is detected by the means; rapid evacuation means to open, means to time a predetermined period of time from the detection of insufficient pressurization, and then restart the pressurizing pump, and when insufficient pressurization is detected, the predetermined pressurization value (this It is characterized by comprising means for adding a required multiplication value and updating the predetermined pressurization value.

The above-mentioned multiplication value is preferably changed (rubbed) depending on the magnitude of the Korotkoff sound signal.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1. FIG. 1 shows a blood pressure measuring device.

In this figure, a pressure detector 21 is provided within a pressure system of a blood pressure measuring device and measures the pressure within this pressure system, and preferably uses a semiconductor pressure sensor.

The pressure system includes a manchet that is wrapped around the arm, a pressure pump 31 (described later) that supplies air to the manchette, and a rubber tube that communicates these.

A pressure signal output from the pressure detector 21 is sent to a blood pressure measurement circuit 23.

The Korotkoff sound detector 22 includes a microphone that collects pulse sounds containing Korotkoff sounds, a bandpass filter that extracts the Korotkoff sound signal from the pulse sound signal output from the microphone, and a waveform shaping circuit. There is.

The Korotkoff sound signal output from the Korotkoff sound detector 22 is also sent to the blood pressure measurement circuit 23.

Measurement of blood pressure is normally carried out by supplying air into the cuff using a pressurizing pump 31 to increase the pressure above the systolic blood pressure of the person being measured, and then gradually lowering this pressure, as will be described in detail later.

The pressure inside the manchet when one Korotkoff sound first occurs during this decompression process is defined as the systolic blood pressure, and then Korotkoff sounds occur continuously, and when the Korotkoff sound disappears or the last Korotkoff sound occurs. The pressure of is considered the lowest blood pressure.

The blood pressure measurement circuit 23 reads the pressure signal of the pressure detector 21 when the Korotkoff sound signal is first sent from the Korotkoff sound detector 22, takes this pressure value as the systolic blood pressure, and when the Korotkoff sound signal is sent from the detector 22 at the end. The output of the detector 21 is read at the time when the blood pressure is output and is taken as the diastolic blood pressure.

The systolic pressure signal and the diastolic pressure signal from the blood pressure measurement circuit 23 are sent to the systolic and diastolic blood pressure indicators 24, respectively.
．． 25, and the systolic blood pressure and diastolic blood pressure are displayed.

Normally, the output of the pressure detector 21 is converted into a digital quantity by an A-D converter, so the systolic and diastolic blood pressure values are displayed in digital quantities.

The initial pressurization value setter 26 is used to preset an initial pressurization value PO, which is considered to be higher than the subject's systolic blood pressure, in a digital quantity, and the initial pressurization value PO is fixed. It may also be variable.

As this setting device 26, for example, a digital switch is used.

The multiplication value storage circuit 32 includes registers 44, 45, and
46, the multiplier value Pi, P2 or P sent from either
Remember 3.

The adder 27 receives the initial pressurization value PO set in the setter 26 and the added value P1 . Add P2 or P3.

This addition result is sent to the storage circuit 28 and stored therein.

The matching circuit 29 receives the stored contents of the memory circuit 28 and the pressure signal outputted from the pressure detector 21 and converted into a digital quantity by the blood pressure measurement circuit 23.

The coincidence circuit 29 outputs a coincidence signal and resets the flip-flop 30 when the value of the pressure signal matches the contents stored in the memory circuit 28 .

The pressurizing pump 31 is controlled by the output O of the flip-flop 30, operates when the flip-flop 30 is set, and stops operating when reset.

The underpressurization detection circuit 35 receives the coincidence signal of the coincidence circuit 29 and the blood pressure measurement circuit 2 outputted from the Korotkoff sound detector 22.
The Korotkoff sound signal sent via 3 is input.

This detection circuit 35 determines whether a Korotkoff sound signal is input when a coincidence signal is input, and outputs an insufficient pressurization detection signal if a Korotkoff sound signal is present.

This insufficient pressurization detection signal is used as a start signal by timer 3.
6t are sent to the AND gates 41, 42, and 43 as control signals.

The timer 36 starts timing operation from the time when the start signal is input.

Then, a signal at the tlHIt level is output from the start of the timing operation until a preset time is reached.

The time set by the timer 36 is set to a time sufficient for the rapid evacuation to be completed and the blood circulation in the brachial artery pressurized by the cuff to be restored, and is preferably in the range of about 20 to 60 seconds, for example.

The output of the timer 36 is sent to the rapid exhaust control circuit 37, insufficient pressurization, standby report device 38, and time-up detection circuit 39y.
This will be sent.

When the timer 36 starts operating and its output reaches the "H" level, the rapid exhaust control circuit 37 fully opens the control valve provided in the pressure system of the blood pressure measurement device to drain the pressure system. evacuate rapidly.

The alarm 38 also informs the user that when the output of the timer 36 reaches the lf Hn level, the pressure system is insufficiently pressurized and that the pressure system should be evacuated once and that the pressure should be pressurized again after a certain period of time. This is to be reported.

The time-up detection circuit 39 detects that when the set time of the timer 36 has elapsed, the output of the timer 36 changes from the H" level to the ``L'' level.
When the level is inverted, the fall of this output is detected and a pulse-like time-up detection signal is output.

This detection signal is sent to the AND gate 33, which opens the gate, and is also input to the OR circuit 34.

A start signal is also sent to the OR circuit 34 from a measurement start switch (path shown).

The output of the OR circuit 34 is sent to the storage circuit 28 as a read command signal, to the flip-flop 30 as a set signal,
Each timer 360 is sent as a reset signal.

The AC-DC converter 47, the AD converter 48, and the decoder 49 detect the magnitude of the Korotkoff sound signal.

The Korotkoff sound signal outputted through the blood pressure measurement circuit 23 is converted into a DC signal by a converter 47, then converted into a digital signal by a converter 48, and inputted to a decoder 49.

On the output side of the decoder 49 there are a number of output terminals, each of which represents the magnitude of the Korotkoff sound signal.

The output terminals of the decoder 49 are divided into three groups in order of magnitude of the Korotkoff sound signals they represent.

In FIG. 1 these groups are indicated by a single line.

The output of each of these groups is AND gate (2) 41-43I
Each of these will be sent.

Therefore, the Korotkoff sound signal input to the decoder 49 is divided into three stages depending on its magnitude.

The registers 44, 45, and 46 are filled with additional values P1, P2, . P3 is set respectively.

If the Korotkoff sound signal has a relative magnitude in the range of, for example, 1 to 5, an output is generated at one of the output terminals of the decoder 49 connected to the AND gate 41, and the register 4
4 is specified.

Similarly, if the magnitude of the Korotkoff sound signal is in the range of 6 to 10, register 45 is designated, and if the magnitude of the Korotkoff sound signal is in the range of 11 to 15, register 46 is designated.

The multiplication value set in each register 44 to 46 is Pi
<P2<P3, for example, Pl is 20iiH
g1P2 is 40 mmHg1P3 is 60 mmHg pressure (corresponds to this).

When the Korotkoff sound signal is small, a small multiplication value is selected, and when the Korotkoff sound signal is large, a large multiplication value is selected.

Now, when the measurement start switch is turned on to measure blood pressure, a start signal is passed through the OR circuit 34 to the memory circuit 28,
Flip flop 30 and timer 360 are sent.

Therefore, the storage circuit 28 reads the contents of the adder 27,
Remember.

A because the time-up detection signal has not been output yet.
The ND gate 33 remains closed, and only the initial pressurization value PO set in the initial pressurization value setter 26 is input to the adder 27.

Therefore, the memory circuit 28 (in this case, the initial pressurization value PO is stored).

Since the flip-flop 30 is set by the start signal from the OR circuit 34, the pressurizing pump 31 starts operating, and air is supplied to the pressure system of the blood pressure measuring device including the cuff, and the inside of the pressure system is pressurized. .

Furthermore, the timer 36 is reset by the start signal.

As the pressure system is pressurized, the pressure sensor 21 outputs a pressure signal representing the pressure within the pressure system, and this pressure signal is converted into a digital quantity by the blood pressure measurement circuit 23 and sent to the coincidence circuit 29.
sent to.

Since the content stored in the memory circuit 28, that is, the initial pressurization value PO is input to the coincidence circuit 29, when the pressure in the pressure system matches this initial pressurization value PO, a coincidence signal is output and the flip-flop 30 is activated. Pressure pump 3 as it will be reset
1 stops operation.

As mentioned above, the Korotkoff sound signal is output when the pressure within the manchet is between the systolic blood pressure and the diastolic blood pressure of the subject.

When the coincidence signal is output from the coincidence circuit 29, the insufficient pressurization detection circuit 35 determines whether the Korotkoff sound signal is output.

If the Korotkoff sound signal is output, the pressure within the pressure system has not reached the systolic blood pressure, indicating insufficient pressurization, and an insufficient pressurization detection signal is output.

When this detection signal is output, the timer 36 starts timing operation, and the rapid exhaust control circuit 37 fully opens the control valve to rapidly exhaust the air in the pressure system, and the indicator 38 indicates that the pressure is insufficient. , a waiting message is displayed.

On the other hand, the magnitude of the Korotkoff sound signal being output at this point is determined by the decoder 49, and the AND gate 4
The output of the decoder 49 is sent to one of the decoders 1 to 43.

These AND gates 41~
Since the gate 43 is opened, one of the registers 44 to 46 is designated by the output of the decoder 49, and the multiplied value set in the designated register is stored in the multiplied value storage circuit 32.

After the set time of the timer 36 has elapsed, the output of the timer 36 becomes L.
When it is inverted to the H level, a time-up detection signal is output from the detection circuit 39 and sent to the OR circuit 34, so the flip-flop 30 is set and the pressure pump 31 is activated again, as in the case above. Air is then pumped into the pressure system.

Needless to say, the control valve is already closed at this time.

Furthermore, the timer 36 is reset by the output of the OR circuit 34.

Since the AND gate 33 is opened by the time-up detection signal, the multiplication value stored in the storage circuit 32 is ANDed.
It is sent to the adder 27 via the gate 33, and the adder 27 adds this multiplied value and the initial pressurization value PO.

- Then, the addition result of the adder 27 is read and stored in the storage circuit 28 by the output of the OR circuit 34.

Therefore, this time, the pressure system of the blood pressure measuring device is pressurized to a pressure equal to the sum of the initial pressurization value PO and the above-mentioned multiplication value, and when the value of the pressure signal coincides with this sum pressure, the coincidence circuit 29 outputs a A signal is output.

As a result, the pressurizing pump 31 stops operating.

If the Korotkoff sound signal is not output when the pressure system is pressurized to the sum of the initial pressurization value PO and the multiplication value, the detection circuit 35 will not output an insufficient pressurization detection signal. Therefore, the timer 36 does not start timing operation and rapid exhaust is not performed.

Thereafter, the control valve is opened manually or automatically, the pressure within the pressure system is gradually reduced, and the systolic blood pressure and diastolic blood pressure are measured.

If the Korotkoff sound signal is still being output, an insufficient pressurization detection signal is output, and the timer 36 starts a timing operation (rapid exhaust, insufficient pressurization, and standby notification are performed).

Similarly, one of the multiplication values P1 to P3 is selected and stored in the storage circuit 32.

In this case, the sum of the previous multiplication value and the current multiplication value is stored in the storage circuit 32 (or it may be stored in the storage circuit 32).
The current multiplication value is stored in , and the initial pressurization value P is stored in the adder 27.
The current multiplication value may be added to the sum of O and the previous multiplication value.

In any case, during the third pressurization (in this case, the pressure system of the blood pressure measuring device is pressurized to the sum of the initial pressurization value PO, the previous multiplication value, and the current multiplication value). Ru.

Note that the adder 27 and the memory circuit 32 are reset every time blood pressure is measured.

When the pressure is increased to an appropriate value higher than the subject's systolic blood pressure and then gradually reduced, a Korotkoff sound signal is output at the pressure of the systolic blood pressure.

As the pressure system is further reduced, the Korotkoff sound signal gradually increases in value, peaks at a certain pressure, and then gradually decreases until it reaches the diastolic pressure. It disappears.

Considering the pressure range higher than the pressure at which the Korotkoff sound signal shows the peak value, the smaller the Korotkoff sound signal output when the matching signal is output from the matching circuit 29 and the pressurization operation stops, the more the pressure increases. The pressure inside the system is close to 0 (systolic blood pressure) (meaning it has been pressurized to this point).

Conversely, if the Korotkoff sound is large, the pressure within the pressure system is only pressurized to a pressure that is far below the systolic blood pressure.

In the device shown in Figure 1, the multiplication value is changed depending on the magnitude of the Korotkoff sound signal; the smaller the Korotkoff sound signal, the smaller the multiplication value, and the thicker the Korotkoff sound signal, the larger the multiplication value. has been done.

Since the magnitude of the multiplication value is selected according to the systolic blood pressure of the person to be measured, the final pressurization pressure is an optimum pressure that is slightly higher than the systolic blood pressure of the person to be measured.

In the device shown in Fig. 1 f, three levels of multiplication values P1 to P3 are preset in registers 44 to 46, but the multiplication values are not limited to three levels, but can also be set to two levels, or four or more levels. Needless to say, you can leave it there.

Alternatively, the multiple multiplication values may be calculated each time according to the magnitude of the Korotkoff sound signal, without setting them in advance.

In this case, it is preferable to make the magnitude of the multiplication value proportional to the thickness 6 of the Korotkoff sound signal.

Some blood pressure measuring devices use a Korotkoff sound signal from a Korotkoff sound detector and a pressure signal from a pressure detector as input signals, and measure systolic blood pressure and diastolic blood pressure using a microprocessor.

The present invention can also be applied to such a blood pressure measuring device.

Even in blood pressure measurement devices using microprocessors,
Provide an initial pressurization value setter, timer, and insufficient pressurization/standby alarm.

In addition, there is a memory area M for the set pressure PS in the memory device.
S is prepared, and a plurality of multiplication values PK (K=1, 2, 3, etc.) are stored in advance in a predetermined storage area.

Referring to FIG. 2, first, the initial pressurization value PO is stored in the storage area MS as the set pressurization pressure PS (step 1), the timer is reset, and the pressurization pump is started to operate (step 2).

Then, the pressure P in the pressure system represented by the pressure signal G is compared with the set pressurization pressure PS (in this case, the initial pressurization value PO) stored in the area MSG.
S! It is determined whether the pressure P has reached the set pressure PSI (step 3), and when the pressure P reaches the set pressure PSI, the process proceeds to step 4, and the operation of the pressurizing pump is stopped.

Next, it is determined whether or not pressurization is insufficient based on the presence or absence of the input of the Korotkoff sound signal, and if the Korotkoff sound signal is not input, the process moves to step 14 and blood pressure measurement processing is executed.

If the Korotkoff sound signal is input, it means that there is insufficient pressurization, so move to step 6, notify that there is insufficient pressurization, rapidly exhaust the air in the pressure system (step 7), and wait for a certain period of time. (Step 8), and starts the timer operation (Step 9).

If the timer setting time has elapsed (step 10)
, standby, and cancel the notification of insufficient pressurization Step 11
, 12), select a pre-stored multiplication value PK according to the magnitude of the Korotkoff sound, add this multiplication value PK and the set pressure PS stored in the area MS,
This addition result is stored in the area MSG and used as a new set pressurizing pressure PS (step 13).

Thereafter, the process returns to step 2 and the same process as above is repeated to increase the pressure to a pressure higher than the systolic blood pressure (step 5), and then the process moves to blood pressure measurement process (step 14).

As explained in detail above, according to the present invention, in the case of insufficient pressurization, the pressurization is interrupted by rapid evacuation, the blood circulation in the brachial artery of the subject is restored, and then the pressure is increased again. Since the blood pressure is pressurized to the maximum, there is no possibility of blood congestion resulting in errors in blood pressure measurement, and there is no negative effect on the body of the person to be measured.

Furthermore, in the case of insufficient pressurization, the pressure can be increased to the optimum value in the second and subsequent pressurization operations.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a flow chart showing part of a microprocessor execution program when the invention is executed using a microprocessor. 21...Pressure detector, 22...Korotkoff sound detector, 26...Initial pressure value setting device, 2
7... Adder, 28... Memory circuit, 2
9... Match circuit, 30... Flip.
Flop, 31... Pressure pump, 32...
...Additional value storage circuit, 35...Insufficient pressurization detection circuit, 36...Timer, 37...Rapid exhaust control circuit, PO... Initial pressure value, PK, P
l, P2゜P3...Additional value.

Claims (1)

[Scope of Claims] 1. A pressurizing pump that supplies air to a pressure system including a manchet to pressurize it, a pressure detector that detects the pressure of the pressure system, a pulse sound that is collected, and a Korotkoff sound signal that is obtained from the pulse sound signal. After the Korotkoff sound detector extracts the pressurized pump,
Coincidence detection means detects that the pressure detected by the pressure detector matches a predetermined value and stops the operation of the pressurizing pump, when the coincidence of pressures is detected by the coincidence detection means,
Insufficient pressurization detection means for detecting insufficient pressurization by outputting a Korotkoff sound signal from a Korotkoff sound detector. A rapid evacuation means opens a pressure system control valve upon detection of insufficient pressurization, means measures a predetermined period of time from detection of insufficient pressurization and then restarts the pressurizing pump, and means detects insufficient pressurization. A pressurization control device for a blood pressure measuring device, comprising means for updating the predetermined pressurization value by adding a required value to the predetermined pressurization value when the predetermined pressurization value is increased. 2. Claim 1, wherein the above-mentioned multiplication value is determined according to the magnitude of the Korotkoff sound signal when insufficient pressurization is detected.
A pressurization control device in the blood pressure measuring device described in 1. 3. A plurality of multiplication values having different values are prepared in advance, and an optimal multiplication value is selected from the plurality of multiplication values according to the magnitude of the Korotkoff sound signal.
A pressurization control device in the blood pressure measuring device described in 1. 4. A pressurization control device for a blood pressure measuring device according to claim 1, which notifies the user of insufficient pressurization. 5 The above-mentioned certain time is in the range of 20 seconds to 60 seconds,
A pressurization control device in a blood pressure measuring device according to claim 1.