JPH0856911A - Blood pressure monitoring system - Google Patents

Abstract

PURPOSE: To provide a blood pressure monitoring system capable of obtaining high blood pressure monitoring accuracy without forcing a burden on a living body. CONSTITUTION: In a process in which the oppressive pressure of a cuff 10 in a blood pressure measuring process by a blood pressure value measuring means 5 is gradually changed, cuff pressure Pms (s=1-j) when a pulse wave that is the pressure vibration of the cuff 10 appears and the amplitude Ams (s=1-j) of the pulse wave are stored in a first storage means 58, and after blood pressure is measured, the pressure of the cuff 10 is changed to a prescribed value PCH to monitor the blood pressure, and cuff pressure Pmm (m=1-k) when the pulse wave appears and the amplitude Amm (m=1-k) of the pulse wave are stored in a second storage means 60, respectively. A blood pressure change judging means 70 judges the change of blood pressure value of the living body based on the cuff pressure Pms (s=1-j) and the amplitude Ams (s=1-j) of the pulse wave, and the cuff pressure Pmm (m=1-k) and the amplitude Amm (m=1-k) of the pulse wave.

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 predetermined value, a pulse wave which is a pressure vibration generated in the cuff is detected, and a blood pressure value is determined based on the magnitude of the pulse wave. An apparatus for monitoring blood pressure by estimating has been proposed. 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.
Like the envelope curve of the pulse wave amplitude shown by the solid line, it changes with the pressure of the cuff, but when the blood pressure value decreases, it has the property of changing like the envelope curve of the pulse wave amplitude shown by the broken line in FIG. When detecting the pulse wave amplitude with the pressure of the cuff set relatively low as shown by P _K in FIG. 23, there is little change in the amplitude with respect to the change in blood pressure value, so such a low set pressure P _K is set. When blood pressure was monitored by using the method, sufficient accuracy could not be 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]

The gist of the present invention for achieving the above object is to change the compression pressure of a cuff wound around a part of a living body to a value equal to or higher than the maximum blood pressure value of the living body. By providing a blood pressure value measuring means for measuring the blood pressure value of the living body by doing, a blood pressure monitoring device for monitoring the blood pressure value of the living body, (a) in the blood pressure measurement process by the blood pressure value measuring means, the pressure vibration of the cuff The first cuff pressure when the pulse wave appears and the magnitude of the pulse wave, and (b) after the blood pressure measurement by the blood pressure value measuring means, the cuff pressure for a predetermined rest period. At least the cuff pressure control means for repeatedly changing to a predetermined pressure value lower than the maximum blood pressure value of the living body, and (c) when the cuff pressure is changed by the cuff pressure control means, the pulse wave is When it appeared Second storage means for storing the cuff pressure and the magnitude of the pulse wave, and (d) the cuff pressure and the magnitude of the pulse wave when the pulse wave stored in the first storage means appears, and 2 blood pressure change determination means for determining a change in the blood pressure value of the living body based on the cuff pressure when the pulse wave stored in the storage means appears and the magnitude of the pulse wave.

[0007]

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. The cuff pressure and the magnitude of the pulse wave when the pulse wave appears when the compression pressure of the cuff is changed by the cuff pressure control means are stored in the second storage means. In the blood pressure change determining means, the cuff pressure when the pulse wave stored in the first storage means appears and the magnitude of the pulse wave, and the cuff when the pulse wave stored in the second storage means appears. A change in the blood pressure value of the living body is determined based on the pressure and the magnitude of the pulse wave.

[0008]

Therefore, according to the blood pressure monitoring apparatus of the present invention, the cuff pressure when the pulse wave appears in the blood pressure measurement process by the blood pressure value measuring means and the magnitude of the pulse wave, and the cuff pressure control means controls the cuff pressure. When the pressure is changed,
Since the blood pressure is monitored based on the cuff pressure when the pulse wave appears and the magnitude of the pulse wave, high monitoring accuracy can be obtained. Further, since the blood pressure is monitored by changing the pressure of the cuff in the low pressure region from the atmospheric pressure to a predetermined pressure value lower than the maximum blood pressure value of the living body, the living body is not burdened.

Here, it is preferable that the pulse wave stored in the second storage means has a cuff pressure lower than the cuff pressure when the maximum amplitude of the pulse wave stored in the first storage means occurs. Further includes maximum amplitude generation pressure comparison means for determining whether or not the maximum amplitude has occurred, and the blood pressure change determination means is the maximum amplitude generation pressure comparison means for storing the pulse stored in the first storage means. When it is determined that the maximum amplitude of the pulse wave stored in the second storage means is occurring at a cuff pressure lower than the cuff pressure at the time when the maximum amplitude of the wave is generated, the blood pressure value of the living body. Determine the change in.

Further, preferably, the pulse wave stored in the second storage means is stored at a cuff pressure lower than the cuff pressure when the maximum amplitude of the pulse wave stored in the first storage means occurs. Maximum amplitude generated pressure comparison means for determining whether or not the maximum amplitude has occurred is further included, and the blood pressure change determination means is configured to detect the pulse wave stored in the first storage means by the maximum amplitude generated pressure comparison means. If it is determined that the maximum amplitude of the pulse wave stored in the second storage means does not occur at a cuff pressure lower than the cuff pressure when the maximum amplitude occurs, the pulse wave is stored in the second storage means. The change in the blood pressure value of the living body is determined based on the change in the pulse wave amplitude being stored with respect to the pulse wave amplitude stored in the first storage means being equal to or greater than a predetermined rate.

Preferably, the pulse wave amplitude is represented by an envelope connecting the maximum values of the pulse waves or an integrated value of the amplitudes of the pulse waves.

Preferably, the rate of change in the amplitude of the pulse wave stored in the first storage means with respect to the cuff pressure and the rate of change in the amplitude of the pulse wave stored in the second storage means with respect to the cuff pressure. A pulse wave change rate calculation means for calculating each is further included, and the blood pressure change determination means is stored in the second storage means and the amplitude change rate of the pulse wave with respect to the cuff pressure stored in the first storage means. The change in the blood pressure value of the living body is determined based on that the difference between the amplitude change rate of the pulse wave and the amplitude change rate with respect to the cuff pressure is equal to or greater than a predetermined value.

Preferably, the pulse rate of the living body is detected when the blood pressure is measured by the blood pressure value measuring means.
The apparatus further includes pulse rate detecting means and second pulse rate detecting means for detecting the pulse rate of the living body when the cuff pressure control means changes the cuff pressure, and the blood pressure change determining means includes the first pulse rate detecting means. When the pulse rate detected by the second pulse rate detecting means changes by a predetermined value or more with respect to the pulse rate detected by, it is determined that the blood pressure value of the living body has changed.

[0014]

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 does not expand and contract. 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 has, 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 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 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 synchronizes with the heartbeat during the gradual pressure change (2 to 3 mm / Hg) of the pressure of the cuff 10 for blood pressure measurement.
It has a relatively narrow frequency band characteristic for extracting the pressure vibration occurring at 0, that is, the pulse wave amplitude without the influence of noise such as motion artifact 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 changeover switch 40 is operated to switch between the once measurement mode and the continuous monitoring mode, and selectively supplies a signal instructing the once measurement mode or the continuous monitoring mode to the CPU 28. 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 a 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 70 described later determines that the blood pressure value of the living body has abnormally changed.

As shown in FIG. 3, 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 systolic 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 lowered at a speed of about 2 to 3 mm / Hg, while the pressure of the cuff 10 is set to be equal to or lower than the minimum blood pressure value P _DIA of the living body during the non-measurement period during which the blood pressure value measuring means 54 does not measure the blood pressure. The pressure is repeatedly changed to the predetermined pressure value P _{CH with a} predetermined rest period T _1M .

In the first storage means 58, a pulse wave, which is a pressure oscillation of the cuff 10, appears in 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. Cuff pressure Pm _s (s
= 1 to j) and the amplitude of the pulse wave Am _s (s = 1 to j)
Memorize each. In addition, the second storage means 60 is a cuff when a pulse wave appears when the pressure of the cuff 10 is changed for blood pressure monitoring after the blood pressure value measurement means 54 measures the blood pressure by the cuff pressure control means 56. Pressure Pm
_m (m = 1 to k) and pulse wave amplitude Am _m (m = 1 to 1)
k) are stored respectively.

The maximum amplitude generation pressure comparing means 62 is a first memory.
The cuff pressure of the pulse wave stored in the means 58 is a predetermined value.
P_CHMaximum amplitude Am of the pulse wave generated below_smaxPulse with
Cuff pressure Pm when wave is generated_smaxSecond, with lower cuff pressure
Maximum amplitude A of the pulse waves stored in the storage means 60
m_mmaxIt is determined whether or not a pulse wave having a value is generated. Well
Further, the pulse wave change rate calculation means 64 is stored in the first storage means 58.
Amplitude change rate K of stored pulse wave with respect to cuff pressure_s,
And the cuff pressure of the pulse wave stored in the second storage means
Amplitude change rate K_mAre calculated respectively. Amplitude variation
Conversion rate K_sAnd K _mIs, for example, the pulse for cuff pressure.
Passes near each amplitude point group in a two-dimensional diagram showing a wave train
It is represented by the slope of the approximate straight line or regression line.

The first pulse rate detecting means 66 detects and stores the pulse rate PR _s of the living body during the blood pressure measurement by the blood pressure value measuring means 54. Also, the second pulse rate detecting means 68
Detects and stores the pulse rate PR _m of the living body when the cuff pressure control means 56 changes the cuff pressure after measuring the blood pressure.

In the blood pressure change determining means 70, the maximum amplitude generated pressure comparison means 62 causes the maximum amplitude of the pulse wave generated when the cuff pressure of the pulse waves stored in the first storage means 58 is a predetermined value P _CH or less. If it is determined that the maximum amplitude Am _{mmax of the} pulse wave stored in the second storage means 60 does not occur at a cuff pressure lower than the cuff pressure P _mean when Am _smax occurs, the second storage is performed. The pulse wave amplitude stored in the means 60 is the first
While the increase in the blood pressure value of the living body is determined based on the change in the pulse wave amplitude stored in the storage unit 58 by a predetermined rate or more, the pulse wave amplitude stored in the second storage unit 60 is determined. The change in the blood pressure value of the living body is determined based on the change in the pulse wave amplitude stored in the first storage means 58 being equal to or more than a predetermined rate. Here, the pulse wave amplitude is represented by an envelope connecting the maximum values of the pulse waves or an integrated value of the amplitudes of the pulse waves.

Further, the blood pressure change determining means 70 has an amplitude change rate K _s with respect to the cuff pressure of the pulse wave generated when the cuff pressure of the pulse waves stored in the first storage means 58 is equal to or lower than a predetermined value P _CH. The change in the blood pressure value of the living body is determined based on the difference between the amplitude change rate K _m of the pulse wave stored in the second storage means 60 and the cuff pressure being larger than a predetermined value.

Further, the blood pressure change determining means 70 has a pulse rate P s detected by the second pulse rate detecting means 68 with respect to the pulse rate PR _s detected by the first pulse rate detecting means 66.
When R _m changes by a predetermined value or more, it is determined that the blood pressure value of the living body has changed. Then, the blood pressure change determination means 70
Comprehensive determination according to the evaluation function of Formula 1 based on each of the above determination results, that is, the change evaluation value D ₁ , the change evaluation value D ₂ , the equivalent evaluation value I, the change evaluation value U ₁ , the change evaluation value U ₂ , and the change evaluation value H. I do. When it is comprehensively determined that the blood pressure value of the living body has abnormally changed, the blood pressure value remeasurement means 72 immediately executes the blood pressure measurement by the cuff 10, and the blood pressure value at the time of abnormality is displayed on the display unit 38.

FIG. 4 is a flow chart for explaining a main part of the control operation of the arithmetic and control unit 26. FIG. 5 shows FIG.
It is a figure which shows the blood pressure value abnormal change determination routine of step S9.

In FIG. 4, 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. 3, 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 mm. It can be gradually lowered at a speed of about / Hg. The cuff pressure when the amplitude of the pulse wave train generated in this gradual decrease process is determined as the systolic blood pressure value P _SYS , and the cuff pressure when the amplitude of the pulse wave train sharply decreases is the minimum blood pressure. Determined as the value P _DIA ,
The cuff pressure when the maximum amplitude pulse wave is generated is the average blood pressure value P.
Determined as _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, at step S2, the cuff pressure Pm _s (s = _s ) when the pulse wave which is the 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 Am _s (s = 1 to j) of the pulse wave thereof are respectively stored in predetermined storage locations of the RAM 30, and the pulse rate PR _s is calculated based on the pulse wave generation interval at that time. Done with R
It is stored in a predetermined storage location of the AM 30. FIG. 6 shows an example of the pulse wave train stored in step S2. Therefore, the predetermined storage location of the RAM 30 used in step S2 corresponds to the first storage means 58 and the first pulse rate detection means 66.

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 time elapsed since the blood pressure measurement in step S1 is executed reaches the time interval T _1M , the above step S1
If 3 the determination is affirmative, after being rapidly increased pressing pressure P _C of the cuff 10 for blood pressure monitor in step S5, the compression pressure P _C of the cuff 10 at step S6
Is reached to a predetermined value P _CH which is equal to or lower than the minimum blood pressure value P _DIA, and when the determination in step S6 is affirmed, the compression pressure P _C of the cuff 10 is 2-3 mm in step S7. It can be gradually lowered at a speed of about / Hg.
The blood pressure monitoring section in FIG. 3 shows this state.

Next, in step S8, the cuff pressure Pm _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.
To k) and the amplitude A _{m m} (m = 1 to k) of the pulse wave are stored, and the pulse rate PR _m is calculated based on the pulse wave generation interval at that time, and stored in a predetermined storage location of the RAM 30. Remembered. Therefore, the predetermined storage location of the RAM 30 used in step S8 is the second storage location.
It corresponds to the storage means 60 and the second pulse rate detection means 68.

Next, it corresponds to the blood pressure change judging means 70.
The blood pressure value change determination routine of step S9 is executed.
It is determined whether the blood pressure value of the living body has changed abnormally.
It This blood pressure value change determination routine is shown in FIG. 5, for example.
To be executed. That is, first, the maximum amplitude generation pressure ratio
In step SM1 corresponding to the comparing means 62, step S
2 of the pulse waves stored in the first storage means 58 in FIG.
Pressure P_CIs the predetermined value P _CHMaximum of pulse wave generated in
Amplitude Am_smaxCuff pressure Pm when a pulse wave with_{sm ax}Yo
Also, in step S8, the data is stored in the second storage means 60.
Maximum amplitude Am of the pulse wave_mmaxOf the pulse wave
Cuff pressure when generated Pm_mmaxIs determined to be low. This
If the determination in step SM1 is positive,
It is determined that the blood pressure value of the living body has changed in M2, and
Change evaluation value D indicating the degree of blood pressure change₁Is memorized. This
Change evaluation value D₁Is (Pm_smax-Pm_mmax) Function
It FIG. 7 shows that the judgment in step SM1 is positive.
The state is shown.

If the determination in step SM1 is negative, the cuff pressure P _C of the pulse wave stored in the first storage means 58 during the blood pressure measurement period in step SM3 corresponding to the pulse wave amplitude calculating means is determined. Those pulse wave amplitudes M _S are calculated from the pulse wave trains generated below the predetermined value P _CH , and those pulse wave amplitudes M _m are calculated from the pulse wave train stored in the second storage means 60 in the monitoring section. It The pulse wave amplitude M _S and the pulse wave amplitude M _m are represented by an envelope connecting the amplitude values of the pulse wave train or by an integrated value of the amplitudes of the pulse wave train.

Then, in step SM4 corresponding to the amplitude value comparing means, the pulse wave amplitude M _S and the pulse wave amplitude M _{m are obtained.}
Are compared. When the pulse wave amplitude M _m is within 20% above and below the pulse wave amplitude M _S , for example, as shown in FIG. 8, the pulse wave amplitude M _S in the monitoring section is compared with the pulse wave amplitude M _S in the blood pressure measurement period. _{Since m} is not changed, it is determined in step SM5 that the blood pressure value of the living body is equal to the blood pressure measurement period, and the equivalent evaluation value I indicating the degree of the equivalence is stored.

Further, in step SM4, when the pulse wave amplitude M _m changes by 50% or more above and below the pulse wave amplitude M _S , for example, as shown in FIG. 9 and FIG. Since the pulse wave amplitude M _m in the monitoring section is significantly changing compared to the wave amplitude M _S , it is determined in step SM6 that the blood pressure value of the living body is changed as compared with the blood pressure measurement period, and A change evaluation value U ₁ indicating the degree of change is stored. This change evaluation value U ₁ is (| M
_S −M _m |) function.

Next, the pulse wave change rate calculating means 64 will be described.
In step SM7, which is stored in the first storage means 58,
Cuff pressure P in the existing pulse wave_CIs the predetermined value P_CHBelow
Amplitude change rate K of generated pulse wave train with respect to cuff pressure_s,
And the pulse wave stored in the second storage means 60.
Pressure P_CIs a predetermined value P_CHCuff pressure of the pulse train generated below
Amplitude change rate K against force_mAre calculated respectively. Shake
Width change rate K_sAnd K _mIs, for example, for cuff pressure
Each amplitude in the two-dimensional diagram showing the size of the above pulse wave train
It is represented by the slope of the regression line of the point cloud.

In the following step SM8, the amplitude change rates K _s and K _m are compared. As shown in FIG. 11, when the rate of change in amplitude K _m is smaller than the rate of change in amplitude K _s , the blood pressure value in the monitoring section is significantly higher than that in the blood pressure measurement period, so in step SM9, It is determined that the blood pressure value has changed, and the change evaluation value U ₂ indicating the degree of increase is stored. This change evaluation value U ₂ is (K _S −K
_m ) function. On the contrary, as shown in FIG. 12, when the difference between the amplitude change rate K _m and the amplitude change rate K _s is larger than the predetermined value α, the blood pressure value in the monitoring section significantly changes compared to the blood pressure measurement period. Since it is in the state, it is determined in step SM10 that the blood pressure value of the living body has changed, and the change evaluation value D ₂ indicating the degree of the decrease is stored. This change evaluation value D
₂ is a function of, for example, (K _m -K _S).

Next, in step SM11, blood pressure measurement
Period pulse rate PR_SAnd pulse rate PR of the monitoring section_mCompared with
Pulse rate PR during blood pressure measurement period_SAnd the pulse rate of the monitoring section
PR _mRatio with_m/ PR_SIs greater than 1, for example
It is determined whether or not the value is larger than the predetermined value K. This step
If the determination made in step SM11 is negative, step SM1
2 is not executed, but when it is affirmed, it is shown in FIG.
Pulse rate PR of the monitoring section_mIs the pulse during the blood pressure measurement period
Number PR_SSince the state has changed more than
It was determined that the blood pressure value of the living body changed significantly in SM12.
The change evaluation value H indicating the change is stored. This
The change evaluation value H of is, for example, PR_m/ PR_SIs a function of
It

Then, in step SM13, the change in blood pressure value of the living body is calculated based on the change evaluation value D ₁ , the change evaluation value D ₂ , the equivalent evaluation value I, the change evaluation value U ₁ , the change evaluation value U ₂ , and the change evaluation value H. Is executed. In this comprehensive judgment, for example, the comprehensive evaluation value S is calculated by the evaluation function of the following expression 1, and the blood pressure value of the living body is abnormally increased based on whether or not the comprehensive evaluation value S exceeds a preset judgment reference value. Alternatively, it is determined whether or not it has decreased. Note that k ₁ , k ₂ , k ₃ , k ₄ , k ₅ , and k ₆ in the following equation 1 are constants.

[0042]

[Equation 1] S = k ₁ H · [k ₂ U ₁ + k ₃ U ₂ − (k ₄ D
₁ + k ₅ D ₂ )] / k ₆ I

If no abnormal change in the blood pressure value of the living body is determined in step SM13, step 9 in FIG.
Is denied, the contents of the timer counter CT are cleared to "0" in step S10,
Steps S3 and below are repeatedly executed. But,
If the determination in step S9 is affirmative, the abnormal blood pressure value of the living body is output to the display unit 38 in step S11, and at the same time, the blood pressure measurement similar to that in step S1 is executed again to determine the blood pressure value at the time of abnormality. It is displayed on the display 38.
This step S11 corresponds to the blood pressure re-measurement means 72 that immediately executes blood pressure measurement when determining the blood pressure abnormality of the living body.

As described above, according to this embodiment, the blood pressure value
Of the blood pressure measuring process of step S1 corresponding to the measuring means 54.
In the process in which the compression pressure of the cuff 10 is gradually changed
When a pulse wave, which is a pressure vibration of the cuff 10, appears
Cuff pressure Pm_s(S = 1 to j) and the amplitude of its pulse wave
Am_s(S = 1 to j) are recorded in the first storage means 58, respectively.
After the blood pressure is measured by the blood pressure value measuring means 54, blood is stored.
The pressure of the cuff 10 is a predetermined value P for pressure monitoring._CHChanged
Cuff pressure Pm when the pulse wave appears_m
(M = 1 to k) and pulse wave amplitude Am_m(M = 1 to k)
Are stored in the second storage means 60, respectively. And blood
In step S9 corresponding to the pressure change determination means 70, the first
When the pulse wave stored in the storage means 58 appears,
Pressure Pm _s(S = 1 to j) and the amplitude Am of the pulse wave
_s(S = 1 to j) is stored in the second storage means 60.
Cuff pressure Pm when a pulse wave appears_m(M = 1 to k)
And pulse wave amplitude Am_mBased on (m = 1 to k) and
Changes in body blood pressure are determined.

Therefore, according to the blood pressure monitoring apparatus of the present embodiment, the cuff pressure Pm _s (s when the pulse wave is generated during the blood pressure measurement period is determined.
= 1 to j) and the pulse wave amplitude Am _{s (s} = 1~j),
Cuff pressure Pm _m (m = 1 to 1) at the time of pulse wave generation in the blood pressure monitoring section
Since blood pressure is monitored based on k) and the pulse wave amplitude Am _m (m = 1 to k), high monitoring accuracy can be obtained. Further, since the blood pressure is monitored by changing the pressure P _{C of the} cuff 10 in the low pressure region from the atmospheric pressure to a predetermined pressure value P _CH which is equal to or lower than the minimum blood pressure value P _{DIA of} the living body, the living body is burdened. There is no.

Further, according to this embodiment, according to the evaluation function of Expression 1, the change evaluation value D ₁ , the change evaluation value D ₂ , the equivalent evaluation value I, the change evaluation value U ₁ , the change evaluation value U ₂ , the change evaluation Value H
Since the comprehensive determination of the change in the blood pressure value of the living body is executed based on the above, the reliability of blood pressure monitoring is enhanced.

Further, in the present embodiment, when the blood pressure value abnormality of the living body is judged, the blood pressure measurement by the cuff 10 is immediately activated and the blood pressure value at the time of abnormality is displayed, so that it is possible to promptly perform when the blood pressure is abnormal. Various treatments are possible.

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 embodiment, step S
If abnormalities change in blood pressure values of a living body is not determined in 9, cuff but pressure monitoring interval to raise the P _C to a predetermined value P _CH were provided repeatedly, 30 minutes or 1 hour or so for each predetermined time interval In addition, step S1 and subsequent steps may be repeatedly executed.

Further, in step S11 of the above-mentioned embodiment, the abnormal blood pressure value may 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 storage. 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 value P _CH which is preset below the minimum blood pressure value P _DIA in the monitoring section, but the average blood pressure value P
A value set slightly higher than _MEAN may be used as the predetermined value P _CH . In such a case, the above-described FIGS. 7 to 13 are as shown in FIGS. 14 to 20. A value set lower than the systolic blood pressure value P _SYS by a predetermined value may be used as the predetermined value P _CH . In such a case, FIGS. 7 and 13 described above are similar to FIGS.
As shown in 2.

Further, steps S2 and S8 of the above-mentioned embodiment.
Then, the pulse rate was detected from the pulse wave which is the pressure vibration of the cuff 10 for blood pressure measurement, but other photoelectric pulse waves, volume pulse waves,
A pulse wave sensor or an electrocardiographic sensor that detects an impedance pulse wave, an electrocardiographic signal, or the like may be provided, and the pulse rate may be calculated from these signals.

The above description is merely an embodiment of the present invention, and the present invention can be modified in various ways without departing from the spirit of the invention.

[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.

FIG. 3 is a time chart showing changes in cuff pressure controlled by the arithmetic control circuit of FIG.

FIG. 4 is a flowchart illustrating a part of control operation of the arithmetic control circuit of FIG.

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

FIG. 6 is a diagram showing a pulse wave train that is generated during a blood pressure measurement period and is stored in the first storage means of FIG.

FIG. 7 is a diagram showing a pulse wave train generated in a blood pressure monitoring section stored in the second storage means of FIG. 2 in comparison with a pulse wave generated in a blood pressure measurement period. The cuff pressure Pm _mmax at which the pulse wave with the maximum amplitude Am _mmax of the wave _train is generated is the maximum of the pulse waves generated during the blood pressure measurement period when the cuff pressure P _{m mmax} is equal to or lower than the predetermined pressure P _CH that is the pressure increase value of the cuff for blood pressure monitoring. It shows a state in which the pulse wave having the amplitude Am _smax is lower than the cuff pressure Pm _smax .

FIG. 8 is a diagram showing a pulse wave train generated in a blood pressure monitoring section stored in the second storage means of FIG. 2 in comparison with a pulse wave generated in a blood pressure measurement period. The amplitude of the wave train shows a state equivalent to the amplitude of the pulse wave train generated during the blood pressure measurement period at a predetermined pressure P _CH or less which is the pressure increase value of the cuff for blood pressure monitoring.

FIG. 9 is a diagram showing a pulse wave train generated in a blood pressure monitoring section stored in the second storage means of FIG. 2 in comparison with a pulse wave generated in a blood pressure measurement period. It shows a state in which the amplitude of the wave train is lower than the amplitude of the pulse wave train generated during the blood pressure measurement period by a predetermined ratio below a predetermined pressure P _CH which is the pressure increase value of the cuff for blood pressure monitoring.

10 is a diagram showing a pulse wave train generated in a blood pressure monitoring section stored in the second storage means of FIG. 2 in comparison with a pulse wave generated in a blood pressure measurement period, and showing a pulse generated in the blood pressure monitoring section. It shows a state in which the amplitude of the wave train is higher than the amplitude of the pulse wave train generated during the blood pressure measurement period by a predetermined ratio below a predetermined pressure P _CH which is the pressure increase value of the cuff for blood pressure monitoring.

FIG. 11 is a diagram showing a pulse wave train generated in a blood pressure monitoring section stored in the second storage means of FIG. 2 in comparison with a pulse wave generated in a blood pressure measurement period. The amplitude change rate K _m of the wave train with respect to the cuff pressure is lower than the amplitude change rate K _{S of} the pulse wave train with respect to the cuff pressure generated during the blood pressure measurement period below a predetermined pressure P _CH which is the pressure increase value of the cuff for blood pressure monitoring. Shows a small state.

FIG. 12 is a diagram showing a pulse wave train generated in a blood pressure monitoring section stored in the second storage means of FIG. 2 in comparison with a pulse wave generated in a blood pressure measurement period. The amplitude change rate K _m of the wave train with respect to the cuff pressure is lower than the amplitude change rate K _{S of} the pulse wave train with respect to the cuff pressure generated during the blood pressure measurement period below a predetermined pressure P _CH which is the pressure increase value of the cuff for blood pressure monitoring. It shows a large state.

FIG. 13 is a diagram showing a pulse wave train generated in a blood pressure monitoring section stored in the second storage means of FIG. 2 in comparison with a pulse wave generated in a blood pressure measurement period. The state is higher than the pulse rate during the blood pressure measurement period.

FIG. 14 is a diagram corresponding to FIG. 7 in an embodiment in which a predetermined pressure P _CH which is a pressure increase value of a cuff for blood pressure monitoring is set to a value slightly higher than the average blood pressure value P _MEAN .

FIG. 15 is a diagram corresponding to FIG. 8 in the embodiment in which the predetermined pressure P _CH that is the pressure increase value of the cuff for blood pressure monitoring is set to a value slightly higher than the average blood pressure value P _MEAN .

FIG. 16 is a diagram corresponding to FIG. 9 in the embodiment in which the predetermined pressure P _CH that is the pressure increase value of the cuff for blood pressure monitoring is set to a value slightly higher than the average blood pressure value P _MEAN .

FIG. 17 is a diagram corresponding to FIG. 10 in the embodiment in which the predetermined pressure P _CH that is the pressure increase value of the cuff for blood pressure monitoring is set to a value slightly higher than the average blood pressure value P _MEAN .

FIG. 18 is a diagram corresponding to FIG. 11 in the embodiment in which the predetermined pressure P _CH that is the pressure increase value of the cuff for blood pressure monitoring is set to a value slightly higher than the average blood pressure value P _MEAN .

FIG. 19 is a diagram corresponding to FIG. 12 in the embodiment in which the predetermined pressure P _CH which is the pressure increase value of the cuff for blood pressure monitoring is set to a value slightly higher than the average blood pressure value P _MEAN .

20 is a diagram corresponding to FIG. 13 in the embodiment in which the predetermined pressure P _CH that is the pressure increase value of the cuff for blood pressure monitoring is set to a value slightly higher than the average blood pressure value P _MEAN .

FIG. 21 is a diagram corresponding to FIG. 7 of an embodiment in which the predetermined pressure P _CH , which is the pressure increase value of the cuff for blood pressure monitoring, is set to a value lower than the maximum blood pressure value P _SYS by a predetermined value.

22 is a diagram corresponding to FIG. 13 of an embodiment in which a predetermined pressure P _CH , which is a pressure increase value of a cuff for blood pressure monitoring, is set to a value lower than the maximum blood pressure value P _SYS by a predetermined value.

FIG. 23 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 detection means) 54: Blood pressure value measurement means 56: Cuff pressure control means 58: First storage means 60: Second Storage unit 62: Maximum amplitude generated pressure comparison unit 64: Pulse wave change rate calculation unit 66: First pulse rate detection unit 68: Second pulse rate detection unit 70: Blood pressure change determination output unit 72: Blood pressure value remeasurement unit

Claims (6)

[Claims] 1. A blood pressure value measuring means for measuring the blood pressure value of the living body by changing the compression pressure of a cuff wound around a part of the living body to a value equal to or higher than the systolic blood pressure value of the living body. A blood pressure monitoring device for monitoring the blood pressure value of the cuff pressure, and stores the cuff pressure and the magnitude of the pulse wave when a pulse wave, which is pressure oscillation of the cuff, appears in the blood pressure measurement process by the blood pressure value measuring means. Cuff pressure control for repeatedly changing the cuff pressure to a predetermined pressure value lower than at least the maximum blood pressure value of the living body after a predetermined blood pressure measurement by the first storage means and the blood pressure value measurement means. Means, second storage means for storing the cuff pressure and the magnitude of the pulse wave when the pulse wave appears when the pressure of the cuff is changed by the cuff pressure control means, and the first storage means Record Based on the cuff pressure when the pulse wave appears and the magnitude of the pulse wave, and the cuff pressure when the pulse wave appears and the magnitude of the pulse wave stored in the second storage means. A blood pressure change determining means for determining a change in the blood pressure value of the living body. 2. The maximum amplitude of the pulse wave stored in the second storage means is generated at a cuff pressure lower than the cuff pressure when the maximum amplitude of the pulse wave stored in the first storage means is generated. The maximum amplitude generation pressure comparison means for determining whether or not the maximum amplitude generation pressure comparison means determines whether the maximum amplitude of the pulse wave stored in the first storage means is generated by the maximum amplitude generation pressure comparison means. If it is determined that the maximum amplitude of the pulse wave stored in the second storage means is generated at a cuff pressure lower than the cuff pressure of, the change in the blood pressure value of the living body is determined. The blood pressure monitoring device according to claim 1. 3. The maximum amplitude of the pulse wave stored in the second storage means is generated at a cuff pressure lower than the cuff pressure when the maximum amplitude of the pulse wave stored in the first storage means is generated. The maximum amplitude generation pressure comparison means for determining whether or not the maximum amplitude generation pressure comparison means determines whether the maximum amplitude of the pulse wave stored in the first storage means is generated by the maximum amplitude generation pressure comparison means. If it is determined that the maximum amplitude of the pulse wave stored in the second storage means does not occur at a cuff pressure lower than that of the pulse wave stored in the second storage means. The change in the blood pressure value of the living body is determined based on the fact that the change in the amplitude with respect to the pulse wave amplitude stored in the first storage means is a predetermined ratio or more.
Blood pressure monitor. 4. The blood pressure monitoring device according to claim 2, wherein the pulse wave amplitude is represented by an envelope connecting the maximum values of the pulse waves or an integrated value of the amplitudes of the pulse waves. 5. A pulse for calculating the amplitude change rate of the pulse wave stored in the first storage means with respect to the cuff pressure and the pulse change rate of the pulse wave stored in the second storage means with respect to the cuff pressure, respectively. A change rate of amplitude of the pulse wave with respect to the cuff pressure stored in the first storage means;
The blood pressure monitoring apparatus according to claim 1, wherein the blood pressure value change of the living body is determined based on a difference between the pulse wave stored in the storage means and the amplitude change rate with respect to the cuff pressure being a predetermined value or more. 6. The first pulse rate detecting means for detecting the pulse rate of the living body when measuring the blood pressure by the blood pressure value measuring means, and the pulse rate of the living body when the cuff pressure changes by the cuff pressure control means. A second pulse rate detecting means, wherein the blood pressure change determining means has a predetermined pulse rate detected by the second pulse rate detecting means with respect to the pulse rate detected by the first pulse rate detecting means. The blood pressure monitoring device according to claim 1, wherein when the blood pressure value of the living body has changed, it is determined that the blood pressure value of the living body has changed.