JP3504360B2 - Blood pressure monitoring device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blood pressure monitor for monitoring a blood pressure value of a living body without imposing a burden on the living body.

[0002]

2. Description of the Related Art When continuously monitoring a blood pressure value of a living body, an automatic blood pressure measuring device having a cuff wound around a part of the living body is used, and the blood pressure measurement by the automatic blood pressure measuring device is performed at a predetermined cycle. In many cases, the blood pressure value is measured by starting it repeatedly. However, in such a case, if the measurement interval is shortened in order to improve the accuracy of blood pressure monitoring, the frequency with which the cuff is pressed against the living body becomes high, so that there is a drawback that a large burden is imposed on the living body.

On the other hand, a cuff attached to a part of a living body is pressurized to a relatively low predetermined value, a pulse wave which is pressure vibration generated in the cuff is detected, and based on the magnitude of the pulse wave. An apparatus has been proposed that monitors blood pressure by estimating a blood pressure value by using the above method. For example, those described in JP-A-61-103432 and JP-A-60-241422.

[0004]

However, in the above-mentioned conventional blood pressure monitoring apparatus, if the pressure of the cuff is set as low as possible in order to reduce the burden on the living body, the pulse wave amplitude corresponding to the change in the blood pressure value is changed. In some cases, changes did not appear easily, and sufficient blood pressure monitoring accuracy could not be obtained. That is, the pulse wave amplitude obtained from the cuff is, for example, as shown in FIG.
It changes with the pressure of the cuff like the envelope of the pulse wave amplitude shown by the solid line, but has the property of changing like the envelope of the pulse wave amplitude shown by the alternate long and short dash line in FIG. 14 when the blood pressure value decreases. from when detecting a pulse wave amplitude in the pressure of the cuff is set relatively low, as shown in P _K in FIG. 14, since the amplitude variation of the relative change in blood pressure value is small, such a low set pressure P _K When blood pressure was monitored in, sufficient accuracy was not obtained.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a blood pressure monitoring device which can obtain high blood pressure monitoring accuracy without imposing a burden on a living body.

[0006]

[0007]

[0008]

[0009]

[First Means for Solving the Problems]Achieving such purpose
Shown in claim 1 forThe gist of the invention is
The compression pressure of the cuff wrapped around a part of the living body should be
By changing the value to a value higher than the high blood pressure value,
A blood pressure value of a living body is provided with a blood pressure value measuring means for measuring the blood pressure value.
A blood pressure monitoring device for monitoring (a) Blood pressure measurement
After measuring the blood pressure by means, the cuff pressure is set to a predetermined value.
After a rest period of
Cuff pressure control means that repeatedly changes to the pressure value,
(b) In the blood pressure measuring process by the blood pressure value measuring means,
Cuff pressure when a pulse wave, which is pressure oscillation of the cuff, appears
And rising shape of the curve showing the first relationship between the magnitude of the pulse wave
And the cuff pressure is changed by the cuff pressure control means.
Cuff pressure and pulse wave magnitude obtained when forced
Based on the deviation between the rising shape of the curve showing the second relation of
Based on this, the blood pressure change judgment for judging the change in the blood pressure value of the living body
And a fixing means, and furtherBlood pressure change determination means,
(c) In the blood pressure measurement process by the blood pressure value measuring means,
When a pulse wave that is the pressure oscillation of the cuff that occurs next appears
Sequentially memorize mushroom cuff pressure and its pulse wave magnitude
1 storage means, and (d) the cuff pressure control means
When the pressure is changed, a pulse wave that appears sequentially appears.
Sequential storage of cuff pressure and pulse wave magnitude
2 storage means, and (e) stored in the first storage means
Rising line showing the first relationship between cuff pressure and pulse wave magnitude
Based on, the amplitude window with a predetermined width in the amplitude direction
C) Amplitude window setting means to set, and (f) its amplitude
Within the amplitude window set by the window setting means
At the cuff pressure stored in the second storage means.
And the number of points indicating the magnitude of the pulse wave are preset judgments.
Displacement judgment that determines the displacement based on whether it exceeds the reference value
And a fixed means.

[0010]

With this configuration, the cuff pressure and the magnitude of the pulse wave when the pulse wave that is the pressure oscillation of the cuff appears in the blood pressure measurement process by the blood pressure value measurement means are stored in the first storage means. When the compression pressure of the cuff is changed by the cuff pressure control means to a value equal to or lower than the average blood pressure value of the living body,
The cuff pressure when the pulse wave appears and the magnitude of the pulse wave are stored in the second storage means. The amplitude window is set by the amplitude window setting means on the basis of the relationship between the cuff pressure and the magnitude of the pulse wave stored in the first storage means.
Then, in the deviation determination means, the number of points indicating the cuff pressure and the magnitude of the pulse wave stored in the second storage means in the amplitude window set by the amplitude window setting means is set as a predetermined determination criterion. The deviation is determined based on whether or not the value is exceeded.

[0011]

Therefore, according to the first aspect of the invention, the cuff pressure and the magnitude of the pulse wave stored in the second storage means within the amplitude window set by the amplitude window setting means can be calculated. Since the change in the blood pressure value of the living body is determined based on the number of points shown, the change in the amplitude at the time of pulse wave generation based on the time of measuring the blood pressure is grasped, and thus the relatively high monitoring accuracy for the blood pressure change Is obtained. Further, since a predetermined pressure value lower than the average blood pressure value of the living body is only applied to the cuff to which pressure is applied for the monitoring, the living body is not burdened.

[0012] Here, in another aspect of the invention described in claim 1, a suitably cuff pressure window relative to the relationship between the size of the cuff pressure and the pulse wave stored in the first storage unit Includes cuff pressure window setting means to set,
The blood pressure change determining means includes, in the cuff pressure window set by the cuff pressure window setting means, the number of points indicating the cuff pressure and the magnitude of the pulse wave stored in the second storage means, and the amplitude window. The change of the blood pressure value of the living body is determined based on the cuff pressure stored in the second storage means and the number of points indicating the magnitude of the pulse wave in the amplitude window set by the setting means.
In this way, the change in the cuff pressure at the time of pulse wave generation based on the time of blood pressure measurement can be grasped, so by combining it with the change of the pulse wave amplitude based on the time of blood pressure measurement, higher monitoring accuracy can be obtained. Is obtained.

Further, preferably, the amplitude window setting means has a relationship of a cuff pressure region lower than the average blood pressure of the living body in the relationship between the cuff pressure and the magnitude of the pulse wave stored in the first storage means. Is calculated by, for example, a least squares approximation line or a regression line, and an amplitude value range of a predetermined width set in the pulse wave amplitude direction from the approximation line Amplitude window calculating means for calculating an amplitude window serving as a boundary in the amplitude direction. In this way, the amplitude window is set accurately.

Further, preferably, the cuff pressure window setting means is in a cuff pressure region lower than the average blood pressure of the living body in the relationship between the cuff pressure and the magnitude of the pulse wave stored in the first storage means. Approximate line calculation means for calculating the approximate line indicating the relationship, for example, by obtaining a least squares approximate line or a regression line, and a cuff pressure range of a predetermined width centered on the approximate line and set in the cuff pressure direction. And a cuff pressure window calculating means for calculating a cuff pressure window that serves as a directional boundary. In this way, the cuff pressure window is set accurately.

[0015]

[Second Means for Achieving the Object ]
The gist of the invention according to claim 2 for achieving is that the compression pressure of the cuff wound around a part of the living body is applied to the living body.
By changing the value to a value above the maximum blood pressure value of
It is equipped with blood pressure measuring means for measuring the blood pressure of the body
A blood pressure monitoring device for monitoring a pressure value, comprising : (a) the blood pressure value
After measuring the blood pressure by the measuring means,
Places below the mean blood pressure of the living body after a predetermined rest period
Cuff pressure control means that repeatedly changes to a constant pressure value
When the blood pressure measurement process odor by (b) the blood pressure measuring means
The cuff when a pulse wave, which is the pressure oscillation of the cuff, appears
Rise of curve showing the first relationship between pressure and pulse wave magnitude
Shape and the cuff pressure by the cuff pressure control means
Large cuff pressure and pulse wave obtained when changed
Deviation between rising shape of curve showing second relation of size
The change in blood pressure of the living body based on
Cuff pressure when a pulse wave that is a pressure vibration of the cuff that sequentially occurs in the blood pressure measurement process by the blood pressure value measurement unit and the blood pressure change determination unit is included. A first storage means for sequentially storing the magnitude of the pulse wave, and (h) the cuff pressure and the pulse wave when the pulse wave sequentially generated when the cuff pressure is changed by the cuff pressure control means appears. A second storage means for sequentially storing the magnitude, and (i) a first rising edge indicating a first relationship between the cuff pressure and the pulse wave magnitude stored in the first storage means in a predetermined cuff pressure section. Area calculation means for calculating an area surrounded by a line and a second rising line showing a second relationship between the cuff pressure and the magnitude of the pulse wave stored in the second storage means, and (j) Based on the size of the area calculated by the area calculation means Deviation determination means for determining deviation.

[0016]

With this configuration, the cuff pressure and the magnitude of the pulse wave when the pulse wave that is the pressure oscillation of the cuff appears in the blood pressure measurement process by the blood pressure value measurement means are stored in the first storage means. When the compression pressure of the cuff is changed by the cuff pressure control means to a value equal to or lower than the average blood pressure value of the living body,
The cuff pressure when the pulse wave appears and the magnitude of the pulse wave are stored in the second storage means. In the area calculating means, a first rising line showing a first relationship between the cuff pressure stored in the first storage means and the magnitude of the pulse wave is stored in the second storage means in the predetermined cuff pressure section. The area surrounded by the second rising line indicating the second relationship between the existing cuff pressure and the magnitude of the pulse wave is calculated. Then, the shift determining means determines the shift based on the size of the area calculated by the area calculating means.

[0017]

According to the second aspect of the invention, therefore, the change in the blood pressure value of the living body is determined based on the size of the area surrounded by the first rising line and the second rising line. Therefore, since the change in the amplitude when the pulse wave is generated with reference to the time when the blood pressure is measured is obtained, relatively high monitoring accuracy for the blood pressure change can be obtained. Further, since a predetermined pressure value lower than the average blood pressure value of the living body is only applied to the cuff to which pressure is applied for the monitoring, the living body is not burdened.

Here, in another aspect of the invention of claim 2 , preferably, the area calculating means includes a first area located on a side having a larger pulse wave amplitude than the first rising line, and The second area located on the side where the pulse wave amplitude is larger than the second rising line is calculated, and the blood pressure change determining means determines that the blood pressure is lowered when the first area is larger than the second area. It further includes a blood pressure drop determining means for determining that there is.
In this way, the blood pressure change and the change tendency of the blood pressure are determined at the same time, so that the blood pressure monitoring accuracy of the living body is further improved.

Further, the area calculating means has a first area located on the side where the pulse wave amplitude is larger than the first rising line,
The second area located on the side where the pulse wave amplitude is larger than the second rising line is calculated, and the blood pressure change determining means determines that the blood pressure is increased when the second area is larger than the first area. It further includes blood pressure increase determination means for determining that there is. In this way, the blood pressure change and the change tendency of the blood pressure are determined at the same time, so that the blood pressure monitoring accuracy of the living body is further improved.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A blood pressure monitoring apparatus according to an embodiment of the present invention will be described below in detail with reference to the drawings.

In FIG. 1, a cuff 10 wound around an upper arm of a living body is compressed, and an inflatable bag 10a made of an elastic film such as a rubber sheet or a vinyl sheet has a non-stretchable arm band 10b. It is configured by being housed inside. Inflatable bag 10a of this cuff 10
Is a pressure sensor 12, an air pump 14, a pressure control valve 16
And the air pipe 18 are connected. Pressure control valve 1
Reference numeral 6 controls the pressure applied to the living body by the cuff 10, and corresponds to the cuff pressure control means 56 described later.

The pressure sensor 12 includes, for example, a semiconductor pressure detecting element, detects the pressure in the cuff 10, and supplies a pressure signal SP representing the pressure to the low pass filter 20 and the band pass filter 22. The low-pass filter 20 discriminates the DC component contained in the pressure signal SP to take out the cuff pressure (static pressure) P _C of the cuff 10, and outputs it as the cuff pressure signal SK to the A / D converter 24. The low pass filter 20 corresponds to the cuff pressure detecting means 50 described later.

Further, the bandpass filter 22 discriminates the frequency component of, for example, 1 to 10 Hz contained in the pressure signal SP, extracts the pulse wave component, and outputs it as the pulse wave signal SM1.
Output to the / D converter 24. In the cuff 10 wound around the upper arm of the living body, the pressure vibration synchronized with the heartbeat is generated based on the pulsation of the artery. The bandpass filter 22 detects the pressure vibration, that is, the pulse wave amplitude generated in the cuff 10 in synchronism with the heartbeat during the gradual pressure change (2 to 3 mmHg / sec) of the pressure of the cuff 10 for measuring the blood pressure as a motion artifact noise. It has a relatively narrow frequency band characteristic for the purpose of taking out without influence of noise. The A / D converter 24 includes a multiplexer that time-divisions the two types of input signals, and has a function of A / D converting the two types of input signals in parallel. The bandpass filter 22 corresponds to a pulse wave detecting means 52 described later.

The arithmetic and control unit 26 includes a CPU 28 and a RAM.
The CPU 28 is a so-called microcomputer including the ROM 30, the output interface 34, and the display interface 36. The CPU 28 stores the signal input from the A / D converter 24 in the ROM 32 in advance while using the temporary storage function of the RAM 30. Process according to the program
The air pump 14 and the pressure control valve 16 are drive-controlled via the output interface 34, and the display 38 is drive-controlled via the display interface 36.
The display 38 is provided with an image display plate capable of displaying numerical values and waveforms by a large number of pixels, and is also equipped with a printer capable of displaying numerical values and waveforms on the recording paper surface with ink as required.

The mode switch 40 is operated to switch between the once measurement mode and the continuous monitoring mode, and selectively supplies the CPU 28 with a signal instructing the once measurement mode or the continuous monitoring mode. Further, the start / stop switch 42 supplies the CPU 28 with a signal for alternately instructing start and stop for each pressing operation.

FIG. 2 is a functional block diagram for explaining the main part of the control function of the arithmetic and control unit 26. The blood pressure monitoring apparatus in the figure has the largest amplitude change rate of the series of pulse waves detected by the pulse wave detecting means 52 when the compression pressure of the cuff 10 wound around a part of the living body is changed. The cuff pressure detected by the cuff pressure detecting means 50 at the place is determined as the systolic blood pressure value P _SYS and the diastolic blood pressure value P _DIA of the living body, and the cuff pressure when the maximum amplitude pulse wave is generated is set as the living body average blood pressure value P _MEAN. A so-called oscillometric blood pressure value measuring means 54 for determining is provided. This blood pressure value measuring means 54
Performs the blood pressure measurement immediately at every preset measurement cycle or when the blood pressure change determining means 72 described later determines that the blood pressure value of the living body has changed significantly.

As shown in FIG. 8, the cuff pressure control means 56 rapidly increases the compression pressure of the cuff 10 to the target pressure P _CM which is set higher than the maximum blood pressure of the living body during the blood pressure measurement period of the blood pressure value measurement means 54. After that, the pressure is gradually decreased at a rate of about 2 to 3 mmHg / sec, while the pressure pressure of the cuff 10 is set to be equal to or lower than the average blood pressure value P _MEAN of the living body in the non-measurement period during which the blood pressure measurement unit 54 does not perform the blood pressure measurement. The predetermined monitoring target cuff pressure P _CH is repeatedly changed with a predetermined rest period T _1M , and thereafter, the compression pressure of the cuff 10 is gradually reduced in order to collect the pulse wave amplitude and the cuff pressure.

The first storage means 58 is the pressure vibration of the cuff 10 during the process of gradually changing the compression pressure of the cuff 10 for measuring the blood pressure of the living body by the blood pressure value measuring means 54 during the blood pressure measurement period. The cuff pressure Pms _n (n = 1 to j) when the pulse wave appears and the amplitude Ams _n (n = 1 to j) of the pulse wave are stored. FIG. 3 shows a pulse wave train whose size changes with an increase in the cuff pressure at that time. Further, the second storage means 60 changes the pressure of the cuff 10 to the monitoring target cuff pressure P _CH by the cuff pressure control means 56 for blood pressure monitoring during the non-measurement period after the blood pressure measurement by the blood pressure value measuring means 54. Cuff pressure Pmm _m (m = 1 to 1) when a pulse wave appears
k) and the amplitude of the pulse wave Amm _m (m = 1 to k) are stored. FIG. 4 shows a pulse wave train whose size changes with an increase in the cuff pressure at that time. The first storage means 58 stores the first cuff pressure Pms _n and the pulse wave magnitude Ams _n .
Is stored, and the cuff pressure P is stored in the second storage means 60.
second relationship of mm _m and the pulse wave amplitudes Amm _m is what is stored.

The amplitude window setting means 62 is the first memory.
Cuff pressure Pms stored in the means 58_nAnd the magnitude of the pulse wave
Ams_nAmplitude window W based on the first relationship of_A
To set. The amplitude window setting means 62 is the first
Cuff pressure Pms stored in the storage means 58_nAnd pulse wave
Width Ams_nOf the first blood pressure value P of the measurement subject
_MEANPredetermined cuff pressure range defined below, for monitoring
Target cuff pressure P_CHLower and lower blood pressure P_DIAtaller than
Approximate line L that approximates the shape of the rising curve in the region
_STo calculate a least squares approximation line or regression line.
Approximate line calculation means 64 determined by and the approximate line L
_SCentered at and then set in the pulse wave amplitude direction
Width H_AAmplitude window whose boundary is the amplitude value range of
Indian W_AAnd an amplitude window calculating means 66 for calculating
including.

Further, the cuff pressure window setting means 68 is
A cuff pressure window W _{P based} on the first relationship between the cuff pressure Pms _n and the pulse wave magnitude Ams _n stored in the first storage means 58 is set. The cuff pressure window setting means 68, and the approximate line calculation unit 64, cuff pressure range then set in the cuff pressure direction and predetermined width H _P around the approximate line L _S calculated by the calculation means 64 the approximate line And a cuff pressure window calculation means 70 for calculating a cuff pressure window W _P having a boundary in the cuff pressure direction. FIG. 5 shows points (○ marks) indicating the cuff pressure Pms _n and the pulse wave amplitude Ams _n stored at the time of blood pressure measurement, and the approximate line L _S , the amplitude window W _A , and the cuff pressure window W _P obtained from the points. And are shown respectively.

The blood pressure change determining means 72 is a blood pressure value measuring means.
In the blood pressure measurement process by 54, the pressure vibration of the cuff 10
Cuff pressure when a pulse wave appears and the magnitude of that pulse wave
The rising shape of the curve showing the first relationship of the size (FIG. 3),
The cuff pressure is changed by the cuff pressure control means 56.
Of cuff pressure and pulse wave magnitude obtained when struck
The difference between the rising shape of the curve (Fig. 4) and
Based on this, a change in the blood pressure value of the living body is determined. That is,
The blood pressure change determination means 72 includes the first storage means 58 and
Second storage means 60 and the amplitude window setting means 62
And a cuff pressure window setting means 68 and a deviation determining means
74, and the deviation determining means 74,
Amplitude window set by the amplitude window setting means 62
Window W _AIn the second storage means 60
Cuff pressure Pmm_m(M = 1 to k) and pulse wave amplitude Amm
_mThe number of points indicating (m = 1 to k) and the cuff pressure window setting
Cuff pressure window W set by the setting means 68_PWithin
The cuff pressure Pmm stored in the second storage means 60
_m(M = 1 to k) and pulse wave amplitude Amm_m(M = 1 ~
The above first relation is shown based on the number of points indicating k)
Curve rising shape showing the second relationship with the curve rising shape
The deviation is detected or determined. This deviation determination means 7
When the deviation is determined by 4, that is, the blood pressure fluctuation of the living body
Is determined by the blood pressure change determining means 72, the blood pressure
The blood pressure value measuring means 5 is immediately measured by the value re-measurement means 76.
Blood pressure measurement using the cuff 10 according to No. 4 is executed,
The blood pressure value when the blood pressure of the fixed person changes is displayed on the display device 38.

FIG. 6 is a flow chart for explaining the main part of the control operation of the arithmetic and control unit 26. FIG. 7 shows FIG.
It is a figure which shows the blood pressure value abnormal change determination routine of step S9.

In FIG. 6, when it is determined that the start / stop switch 42 of the blood pressure monitor is operated and the continuous monitoring mode is selected by the mode changeover switch 40 in a step (not shown), the blood pressure is changed. The blood pressure measurement routine of step S1 corresponding to the value measuring means 54 is executed. In this step S1, as shown in the blood pressure measurement period of FIG. 8, the compression pressure P _C of the cuff 10 is rapidly raised to the target pressure P _CM set higher than the systolic blood pressure of the living body, and then 2-3 mmHg. It can be slowly lowered at a speed of about / sec. The cuff pressure when the amplitude of the pulse wave train (FIG. 3) generated in this slow-decreasing process is determined as the systolic blood pressure value P _SYS , and the cuff pressure when the amplitude of the pulse wave train is rapidly decreased. The pressure is determined as the minimum blood pressure value P _DIA , and the cuff pressure when the pulse wave having the maximum amplitude is generated is determined as the average blood pressure value P _MEAN . Then, when the determination of the blood pressure value is completed, the compression pressure P _C of the cuff 10 is rapidly lowered.

Next, in step S2, the cuff pressure Pms _n (n = _n ) when a pulse wave, which is pressure oscillation of the cuff 10, appears in the process of gradually changing the compression pressure of the cuff 10 during the blood pressure measurement period. 1 to j) and the amplitude Ams _n (n = _{1 to} j) of the pulse wave thereof are stored in predetermined storage locations of the RAM 30, respectively. FIG. 3 shows an example of the pulse wave train stored in step S2. Therefore, the predetermined storage location in the RAM 30 used in step S2 corresponds to the first storage means 58.

In the following step S3, the timer counter C
It is determined whether the content of T is _{equal to} or longer than a preset time interval T _1M . The timer counter CT is step S
The time interval T _1M is a value corresponding to the blood pressure monitoring interval after the blood pressure measurement is executed. Since the determination in step S3 is initially denied, "1" is added to the content of the timer counter CT in step S4, and then steps S3 and thereafter are repeatedly executed.

When the elapsed time after the blood pressure measurement in step S1 is executed reaches the preset time interval T _1M ,
If the determination in step S3 is positive, step S5
In step S6, after the compression pressure P _C of the cuff 10 is rapidly increased for blood pressure monitoring in step S6.
It is determined whether or not the compression pressure P _C of the cuff 10 has reached a predetermined value P _CH that is equal to or less than the average blood pressure value P _{MEAN. C} is gradually lowered at a speed of about 2 to 3 mmHg / sec. The blood pressure monitoring section in FIG. 8 shows this state.

Next, in step S8, the cuff pressure Pmm _m (m = 1) when a pulse wave appears in the process of gradually changing the compression pressure of the cuff 10 in the blood pressure monitoring section.
~ K) and pulse wave amplitude Amm _m (m = 1 to k) is RAM
It is stored in 30 predetermined storage locations. Therefore, the predetermined storage location in the RAM 30 used in this step S8 corresponds to the second storage means 60.

Then, the blood pressure value change determination routine of step S9 is executed to determine whether or not the blood pressure value of the living body has changed abnormally. This blood pressure value change determination routine is executed as shown in FIG. 7, for example. That is, first, in step S9-1 corresponding to the approximate line calculation means 64,
Of the relationship between the cuff pressure Pms _n and the pulse wave magnitude Ams _n stored in a predetermined storage location (first storage means 58) of the RAM 30, a predetermined blood pressure value P _MEAN of the subject or less is determined. The approximate line L _S indicating the relationship in the cuff pressure region lower than the monitoring target cuff pressure P _CH is determined by calculating a least squares approximation line or a regression line.

Next, the amplitude window calculating means 66
In step S9-2 corresponding to, the predetermined width H _A set in the pulse wave amplitude direction from the approximate line L _S as the center.
An amplitude window W _A having the amplitude value range of (for example, 30% above and below the approximate line L _S ) as the boundary in the pulse wave amplitude direction is calculated. In step S9-3 corresponds to the cuff pressure window calculation unit 70, the approximate line L predetermined _S then set in cuff pressure direction about the width H _P (for example 30% the left and right approximation lines L _S) A cuff pressure window W _P having the cuff pressure range as a boundary in the cuff pressure direction is calculated.

In the following step S9-4, the pressure Pmm _m (m = 1 to k) and the pulse wave amplitude Amm _m (m stored in a predetermined storage location (second storage means 60) of the RAM 30.
= 1 to k) (marked by □ in FIG. 5), it is determined whether or not the ratio existing in the amplitude window W _A is equal to or greater than a preset determination reference value A, and step S9. At −5, the proportion of those points existing in the cuff pressure window W _P is set to a preset judgment reference value B.
It is determined whether or not there is the above. The judgment reference values A and B are values for judging the presence or absence of blood pressure fluctuations of the subject to be monitored, and for example, a value of about 50% is used. In the present embodiment, the steps S9-4 and S9-5 correspond to the deviation determining means 74.

Steps S9-4 and S9 described above.
If either one of -5 is affirmative, it is determined in step S9-6 that there is no blood pressure change, but if the determinations in step S9-4 and step S9-5 are both negative, step S9. At -7, it is determined that there is blood pressure fluctuation.

When the abnormal change in the blood pressure value of the person to be measured is not determined in the above, the determination in step S9 of FIG. 6 is denied, so that the content of the timer counter CT is cleared to "0" in step S10. After that, step S3 and subsequent steps are repeatedly executed. However, if the determination in step S9 is affirmative, step S11
At the same time, the abnormal blood pressure value of the living body is output to the display device 38, and at the same time, the blood pressure measurement similar to step S1 is executed again, and the blood pressure value at the time of abnormality is displayed on the display device 38. This re-blood pressure measurement corresponds to that at the right end of the blood pressure measurement period in FIG. In this embodiment, step S11
Corresponds to the blood pressure value re-measurement means 76 that immediately executes blood pressure measurement when determining the blood pressure abnormality of the living body.

As described above, according to this embodiment, in the blood pressure measuring process in step S1 corresponding to the blood pressure value measuring means 54, the cuff pressure Pms _n and the pulse when the pulse wave which is the pressure vibration of the cuff appears. The wave size Ams _n is stored in the first storage means 58, and the cuff pressure control means 56 changes the cuff compression pressure P _C to a value P _CH set below the mean blood pressure value P _MEAN of the subject. The cuff pressure Pmm _m when the pulse wave appears and the amplitude Amm _m of the pulse wave are stored in the second storage means 60. In steps S9-1 and S9-2 corresponding to the amplitude window setting means 62, the cuff pressure Pms _n stored in the first storage means 58.
And an amplitude window W _A based on the relationship between the pulse wave magnitude Ams _n is set. Also, steps S9-1 and S9 corresponding to the cuff pressure window setting means 68.
At -3, the cuff pressure window W _{P based on} the relationship between the cuff pressure Pms _n and the pulse wave magnitude Ams _n stored in the first storage means 58 is set. Then, step S9-4 and step S9- corresponding to the deviation determining means 74.
5, the blood pressure of the subject is measured based on the number of points indicating the cuff pressure _{P mm m} and the pulse wave amplitude A mm _m stored in the second storage means 60 in the amplitude window W _A and the cuff pressure window W _P. The presence or absence of fluctuation is determined. Therefore, since the change based on the blood pressure measurement is grasped by the pulse wave amplitude when the pulse wave is generated and the cuff pressure at that time,
A relatively high accuracy of monitoring blood pressure changes can be obtained. Further, since a predetermined pressure value lower than the average blood pressure value of the living body is only applied to the cuff to which pressure is applied for the monitoring, the living body is not burdened.

Further, in the present embodiment, in step S9-4 and step S9-5 corresponding to the deviation determining means 74, the ratio of the points existing in the amplitude window W _A is equal to or less than the determination reference value A and the cuff. Since the blood pressure fluctuation of the measurement subject is determined when the ratio of the points existing in the pressure window W _P is equal to or less than the determination reference value B, the reliability is further enhanced.

In the amplitude window setting means 62 or the cuff pressure window setting means 68 of this embodiment, the relationship between the cuff pressure Pms _n and the pulse wave magnitude Ams _n stored in the first storage means 58 is stored. Among them, the average blood pressure value of the living body P _MEAN
Since an approximate line calculation means 64 is provided for calculating the approximate line L _S indicating the relationship in the cuff pressure region lower than the value P _CH set below by, for example, obtaining a least squares approximation line or a regression line, the amplitude is set. There is an advantage that the window W _A and the cuff pressure window W _P are accurately set.

Further, in the present embodiment, when the blood pressure value abnormality of the living body is judged, the blood pressure value re-measurement means 76 immediately activates the blood pressure measurement by the cuff 10, and the blood pressure value at the time of abnormality is displayed. Therefore, it is possible to perform prompt treatment when blood pressure is abnormal.

Next, another embodiment of the present invention will be described. In the following description, the same parts as those in the above-described embodiment will be designated by the same reference numerals and the description thereof will be omitted.

FIG. 9 is a functional block diagram showing a main part of the control function of the arithmetic and control unit 26 in another embodiment of the present invention. In the figure, the blood pressure change determination means 80 shows a first relationship between the cuff pressure and the magnitude of the pulse wave when a pulse wave, which is the pressure oscillation of the cuff 10, appears in the blood pressure measurement process by the blood pressure value measurement means 54. The rising shape of the curve (FIG. 3) and the rising shape of the curve (FIG. 3) showing the second relationship between the cuff pressure and the magnitude of the pulse wave obtained when the cuff pressure is changed by the cuff pressure control means 56. The change in the blood pressure value of the living body is determined on the basis of the difference between 4). That is, the blood pressure change determination means 80 is configured to use the first storage means 5
8 and the second storage means 60, the area calculation means 82, the deviation determination means 84, the blood pressure increase determination means 86, and the blood pressure decrease determination means 88, and the area calculation means 82.
Is a predetermined cuff pressure range A defined below the average blood pressure value P _{MEAN of the} person to be measured, for example, in the cuff pressure range from the minimum blood pressure value P _DIA to the average blood pressure value P _MEAN or the monitoring target cuff pressure P _CH , A first rising line showing a rising portion of the first relationship between the cuff pressure Pms _n and the pulse wave magnitude Ams _n stored in the first storage means 58, and the second storage means 60.
Cuff pressure P _{mm m} and pulse wave size A mm _m stored in
The area S (= S _A + S _B ) surrounded by the second rising line indicating the rising portion of the second relationship with is calculated. Figure 1
1, FIG. 12, and FIG. 13, the solid line shows the first relationship and the broken line shows the second relationship. Then, the shift determining means 84 shifts the rising shape of the first relationship shown by the solid line and the rising shape of the second relationship shown by the broken line based on the size of the area S calculated by the area calculating means 82. Is detected or determined.

The area calculating means 82 is shown in FIG. 11 and FIG.
2, within the cuff pressure range A of FIG. 13, the first shown by the solid line
The first area S _A located on the side where the pulse wave amplitude is larger than the rising line and the second area S _B located on the side where the pulse wave amplitude is larger than the second rising line shown by the broken line are calculated. ,
The blood pressure increase determination means 86 determines that the blood pressure is increased when the second area S _B is larger than the first area S _A , and the blood pressure decrease determination means 88 determines that the first area S _A is the second area. S
If it is larger than _B, it is determined that the blood pressure is low.

FIG. 10 is a flow chart showing the main part of the control operation of the arithmetic and control unit 26 of this embodiment. In the figure, in step S9-11, the first area S _A and the second area S _B are calculated based on the data stored in the first storage means 58 and the second storage means 60, and step S9-
In 12, the first area S _A and the second area S _B are added to each other, so that the first relationship between the cuff pressure Pms _n and the pulse wave magnitude Ams _n stored in the first storage means 58. The first rising line showing the rising part of the second storage means 6 and the second storage means 6
Cuff pressure Pmm _m and pulse wave size Amm stored in 0
An area S surrounded by the second rising line indicating the rising portion of the second relationship with _m is calculated. In this embodiment, steps S9-11 and S9-12 correspond to the area calculating means 82.

[0051] At step S9-13 corresponding to the deviation determining means 84, whether the area S is preset determination reference value S _O more it is determined. This judgment reference value S _O is a value that has been experimentally obtained in advance in order to judge the change in the blood pressure value of the living body. This Step S9-13
If the determination is negative, it means that the deviation between the shapes of the first rising line and the second rising line is small as shown in, for example, FIG. 11, and thus, in step S9-14,
It is determined that there is no change in blood pressure.

However, if the determination in step S9-13 is affirmative, for example, as shown in FIGS. 12 and 13, there is a large deviation between the shapes of the first rising line and the second rising line. Therefore, in step S9-15,
It is determined whether the first area S _A is greater than or equal to the second area S _B. If the determination in step S9-15 is negative, for example, the state is as shown in FIG. 12, so it is determined in step S9-16 corresponding to the blood pressure increase determination means 86 that there is blood pressure fluctuation in the blood pressure increase direction. To be done. Conversely, if the determination in step S9-15 is affirmative,
For example, since the state is as shown in FIG. 13, it is determined in step S9-17 corresponding to the blood pressure decrease determining means 88 that the blood pressure changes in the blood pressure decreasing direction.

As described above, according to this embodiment, in the blood pressure measuring process by the blood pressure value measuring means 54, the cuff pressure Pms _n when the pulse wave which is the pressure oscillation of the cuff 10 appears and the magnitude of the pulse wave. Ams _n is stored in the first storage means 58, and the cuff pressure Pmm when the pulse wave appears when the cuff pressure control means 56 changes the cuff compression pressure to a value equal to or lower than the average blood pressure value of the living body. _m and pulse wave magnitude A
mm _m is stored in the second storage means 60. Area calculation means 8
2, in the predetermined cuff pressure range, the first storage means 58
Cuff pressure Pms _n and pulse wave magnitude Ams _n stored in
A first rising line showing a first relationship with the second storage means 6
Cuff pressure Pmm _m and pulse wave size Amm stored in 0
An area S surrounded by the second rising line indicating the second relationship with _m is calculated. Then, in the deviation determination means 84,
The deviation is determined based on the size of the area S calculated by the area calculation means 82. Therefore, since the change in the blood pressure value of the living body is determined based on the size of the area S, the change in the amplitude at the time of pulse wave generation based on the time at which the blood pressure is measured is grasped, and thus the change in blood pressure is relatively high. High monitoring accuracy can be obtained. Further, since the cuff to which the pressure is applied for the monitoring is merely pressed to the predetermined monitoring target cuff pressure P _CH which is equal to or lower than the average blood pressure value P _{MEAN of} the living body, the living body is burdened. There is no.

Further, according to this embodiment, the area calculating means 8
According to 2, the first area S _A located on the side where the pulse wave amplitude is larger than the first rising line and the second area S _B located on the side where the pulse wave amplitude is larger than the second rising line are calculated. On the other hand, when the second area S _B is larger than the first area S _A , the blood pressure increase determination unit 86 determines that the blood pressure is in the blood pressure increasing direction, and the first area S _A is larger than the second area S _B. In this case, the blood pressure decrease determining means 88 determines that the blood pressure is in the blood pressure change direction, so that the blood pressure monitoring accuracy of the living body is further improved.

Although one embodiment of the present invention has been described above with reference to the drawings, the present invention can be applied to other modes.

For example, in the above-described embodiment, based on the number of points indicating the second rising line existing in the amplitude window and the cuff pressure window set on the basis of the first rising line, or at a predetermined cuff pressure. The blood pressure fluctuation of the living body is determined based on the area S surrounded by the first rising line and the second rising line in the range A. For example, the phase between the first rising line and the second coefficient rising line is determined. The blood pressure fluctuation of the living body may be determined based on the magnitude of the relationship number. In short, the first
It is only necessary to determine the blood pressure fluctuation of the living body based on the deviation between the shapes of the rising line and the second rising line.

Further, in step S9 of the above-described embodiment, the amplitude window W _A and the cuff pressure window W _{P are set.}
The abnormal change of the blood pressure value of the living body was determined using
Either of them may be used for the determination, for example, using only the amplitude window W _A.

Further, in the above-described embodiment, the amplitude window W _A and the cuff pressure window W _P are linearly approximated by approximating the first rising line of the curve showing the first relationship stored in the first storage means 58. Although the line L _S is set as the reference, the curved first rising line or the bent first rising line may be set as the reference.

Further, in the above-mentioned embodiment, when the fluctuation of the blood pressure value of the living body is not judged in step S9, the monitoring section for raising the cuff pressure P _C to the predetermined value P _CH is repeatedly provided. The step S1 and subsequent steps may be repeatedly executed at predetermined time intervals of minutes or one hour.

Further, in step S11 of the above-mentioned embodiment, the abnormal blood pressure value may only be output.

Further, in the above-described embodiment, the pulse wave generated in the gradual pressure reduction process after the pressure of the cuff 10 is rapidly increased toward the predetermined value P _CH by the cuff pressure control means 56 is stored in the second memory. Although it is configured to be stored in the means 60, the pulse wave generated in the process of gradually increasing the pressure may be collected and stored in the second storage means 60. Also in the blood pressure measurement period, the blood pressure value is determined based on the change in the magnitude of the pulse wave generated in the gradual depressurization process after the cuff 10 is rapidly raised to P _CM, and the pulse wave is the first pulse wave. Although it is configured to be stored in the storage means 58, the blood pressure value is determined based on the change in the magnitude of the pulse wave generated in the process of gradually increasing the pressure, and the pulse wave is stored in the first storage means 58. It may be stored.

Further, in the above-described embodiment, the cuff 10 is raised to the predetermined monitoring target cuff pressure P _CH set below the average blood pressure value P _MEAN in the monitoring section, but the minimum blood pressure value P _DIA A value set slightly higher may be used as the predetermined value P _CH .

Although the cuff pressure range A in the above-described embodiment is the range from the minimum blood pressure value P _DIA to the average blood pressure value P _MEAN , the target monitoring cuff pressure P _CH is slightly smaller than the average blood pressure value P _MEAN. When it is set low, it may be in the range from the minimum blood pressure value P _DIA to the monitoring target cuff pressure P _CH , or may be in a range narrower than that by a predetermined value.

The above description is merely one embodiment of the present invention, and the present invention can be variously modified without departing from the gist thereof.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a configuration of an embodiment of a blood pressure monitoring device of the present invention.

FIG. 2 is a functional block diagram illustrating a main part of a control function of the arithmetic control circuit of FIG.

3 is a pulse wave train generated in the blood pressure measurement period in the embodiment of FIG. 1 and stored in the first storage means of FIG. 2, the pulse wave amplitude of the pulse wave and the cuff pressure when the pulse wave is generated. FIG.

FIG. 4 is a pulse wave train generated in the monitoring section in the embodiment of FIG. 1 and stored in the second storage means of FIG.
It is a figure which shows the pulse wave amplitude of the collected pulse wave and the cuff pressure at the time of pulse wave generation.

5 is an approximate line L _S showing the relationship between the pulse wave amplitude of the pulse wave sampled during the blood pressure measurement period and the cuff pressure when the pulse wave is generated in the embodiment of FIG. 1, an amplitude window W _A , and a cuff pressure window W _P. It is a figure explaining each.

6 is a flowchart illustrating a part of control operation of the arithmetic and control unit of FIG.

FIG. 7 is a diagram showing a blood pressure value abnormal change determination routine in step S9 of FIG.

8 is a time chart for explaining changes in cuff pressure in the embodiment of FIG.

FIG. 9 is a functional block diagram illustrating a main part of a control function of an arithmetic and control unit according to another embodiment of the present invention.

10 is a flowchart illustrating a main part of control operation of the arithmetic and control unit according to the embodiment of FIG. 9, and is a diagram corresponding to FIG. 7.

FIG. 11 is a first rising curve (solid line) showing the first relationship between the pulse wave amplitude detected during the blood pressure measurement period and the cuff pressure at that time, and the pulse wave amplitude detected in the subsequent monitoring section. It is a figure which contrasts with the 2nd rising curve (broken line) which shows the 2nd relation between it and the cuff pressure at that time, and is a figure showing the state where there is no blood pressure fluctuation.

FIG. 12 is a first rising curve (solid line) showing the first relationship between the pulse wave amplitude detected during the blood pressure measurement period and the cuff pressure at that time, and the pulse wave amplitude detected in the subsequent monitoring section. It is a figure which contrasts with the 2nd rising curve (broken line) which shows the 2nd relation between it and the cuff pressure at that time, and is a figure showing the state where there is blood pressure fluctuation of the blood pressure rise direction.

FIG. 13 is a first rising curve (solid line) showing the first relationship between the pulse wave amplitude detected during the blood pressure measurement period and the cuff pressure at that time, and the pulse wave amplitude detected in the subsequent monitoring section. It is a figure which contrasts with the 2nd rising curve (broken line) which shows the 2nd relation between it and the cuff pressure at that time, and is a figure showing the state where there is blood pressure fluctuation in the direction of blood pressure decrease.

FIG. 14 is a diagram showing a blood pressure monitoring operation based on a pulse wave amplitude in a conventional blood pressure monitoring device.

[Explanation of symbols]

10: Cuff 20: Low-pass filter (50: Cuff pressure detection means) 22: band pass filter (52: pulse wave detecting means) 54: blood pressure value measuring means 56: Cuff pressure control means 58: First storage means 60: Second storage means 62: Amplitude window setting means 64: Approximate line calculation means 72, 80: blood pressure change determination means 74, 84: Deviation determining means 76: Blood pressure value re-measurement means 82: Area calculation means

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-6-142066 (JP, A) JP-A-6-292660 (JP, A) JP-A-53-51687 (JP, A) European Patent 698370 (EP , B1) US Patent 5563241 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61B 5/022

Claims (2)

(57) [Claims] 1. A compression pressure of a cuff wrapped around a part of a living body.
By changing the value to a value higher than the systolic blood pressure value of the living body.
A blood pressure value measuring means for measuring the blood pressure value of the living body,
A blood pressure monitoring device for monitoring a blood pressure value of a living body , wherein after the blood pressure is measured by the blood pressure value measuring means,
The cuff pressure is the average blood pressure of the living body after a predetermined rest period.
Cuff pressure that is repeatedly changed to a predetermined pressure value below the specified value
In the blood pressure measurement process by the control means and the blood pressure value measurement means,
Cuff pressure when a pulse wave, which is pressure vibration of
And the rising shape of the curve showing the first relationship of the magnitude of the pulse wave
And the cuff pressure is changed by the cuff pressure control means.
Of the cuff pressure and the pulse wave magnitude obtained when
Based on the deviation between the rising shape of the curve showing the second relation
The change in blood pressure of the living body
And a means for determining the blood pressure change , wherein the blood pressure change determining means determines the cuff pressure and the magnitude of the pulse wave when a pulse wave that is a pressure oscillation of the cuff sequentially occurs in the blood pressure measurement process by the blood pressure value measuring means. First storage means for sequentially storing, and second storage for sequentially storing the cuff pressure and the magnitude of the pulse wave when a pulse wave sequentially generated when the pressure of the cuff is changed by the cuff pressure control means appears. And an amplitude window setting means for setting an amplitude window having a predetermined width in the amplitude direction with reference to a rising line indicating the first relationship between the cuff pressure and the magnitude of the pulse wave stored in the first storage means. And the number of points indicating the cuff pressure and the magnitude of the pulse wave stored in the second storage means within the amplitude window set by the amplitude window setting means is preset. And determining deviation determination means the deviation based on whether exceeds the determination reference value, a blood pressure monitor, which comprises
apparatus. 2. A compression pressure of a cuff wrapped around a part of a living body.
By changing the value to a value higher than the systolic blood pressure value of the living body.
A blood pressure value measuring means for measuring the blood pressure value of the living body,
A blood pressure monitoring device for monitoring a blood pressure value of a living body , wherein after the blood pressure is measured by the blood pressure value measuring means,
The cuff pressure is the average blood pressure of the living body after a predetermined rest period.
Cuff pressure that is repeatedly changed to a predetermined pressure value below the specified value
In the blood pressure measurement process by the control means and the blood pressure value measurement means,
Cuff pressure when a pulse wave, which is pressure vibration of
And the rising shape of the curve showing the first relationship of the magnitude of the pulse wave
And the cuff pressure is changed by the cuff pressure control means.
Of the cuff pressure and the pulse wave magnitude obtained when
Based on the deviation between the rising shape of the curve showing the second relation
The change in blood pressure of the living body
And a means for determining the blood pressure change , wherein the blood pressure change determining means determines the cuff pressure and the magnitude of the pulse wave when a pulse wave that is a pressure oscillation of the cuff sequentially occurs in the blood pressure measurement process by the blood pressure value measuring means. First storage means for sequentially storing, and second storage for sequentially storing the cuff pressure and the magnitude of the pulse wave when a pulse wave sequentially generated when the pressure of the cuff is changed by the cuff pressure control means appears. Means, a first rising line indicating a first relationship between the cuff pressure and the magnitude of the pulse wave stored in the first storage means in a predetermined cuff pressure section, and stored in the second storage means. Area calculating means for calculating an area surrounded by a second rising line showing a second relationship between the cuff pressure and the magnitude of the pulse wave, and the area calculating means based on the area calculated by the area calculating means. Without judging the deviation Patent that the determining means includes
Blood pressure monitoring device.