JPH1066680A - Blood pressure monitoring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide high blood pressure monitoring accuracy in a blood pres sure monitoring device for monitoring the blood pressure value of a living body based on the propagation speed or propagation time of pulse waves propa gated inside the artery of the living body. SOLUTION: By a correspondence relation correction means 86, the correspondence relation of the blood pressure value MBP and the propagation speed VM decided by a propagation speed and blood pressure correspondence relation decision means 76 based on the change δSR or δSD of the ratio SR or difference SD of the respective signal strength of a heart beat cycle fluctuation high-frequency component HFC2 and a propagation speed fluctuation low-frequency component LFC2 is corrected. Thus, in the case that the ratio or difference of the respective signal strength of the heart beat cycle fluctuation high-frequency component HFC1 and the propagation speed fluctuation low-frequency component LFC2 is changed, that is in the case that the state of the autonomic nerve of a person to be measured is changed, since the correspondence relation is corrected based on the change value, the accurate blood pressure value is decided at all times regardless of the state of the autonomic nerve of the person to be measured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blood pressure monitoring device for monitoring a blood pressure of a living body based on pulse wave propagation speed information such as a propagation speed or a propagation time of a pulse wave propagating in an artery of the living body. .

[0002]

2. Description of the Related Art Propagation speed of a pulse wave propagating in an artery of a living body
Propagation velocity V as information_M(M / s) or propagation time TD_RP
(Sec) is proportional to the blood pressure value BP (mmHg) of the living body or
It is known to have an inversely proportional relationship. So,
Blood pressure value BP and propagation velocity V measured_MFrom
For example, BP = A (V_M) + B
Coefficients A and B are determined in advance, and from the relational expression,
Next measured propagation velocity V _MBased on the blood pressure value B of the living body
A blood pressure monitoring device that monitors P has been proposed. Place
And the propagation speed V_MIs the heart, artery or periphery of the body
A pair of pulse-synchronous-wave sensors mounted on two sites on an artery
For each period of a pair of pulse synchronous waves detected by
Is the predetermined relationship based on the time difference between the predetermined parts that occur?
It is calculated from Generally, the propagation speed is increased by increasing the time difference.
V_MIn order to improve the measurement accuracy of the first pulse wave detection device,
Position on the more central heart or artery and the second pulse wave
The detection device is mounted on the peripheral artery.

[0003]

[SUMMARY OF THE INVENTION to be solved] However, for example, since the particular peripheral artery of the artery is known to be contracted by mental strain, etc., of the propagation velocity V _M and peripheral arteries are contracted to increase, Correspondence between pulse wave velocity information and blood pressure values because the arterial wall stiffness changes due to changes in the degree of autonomic nervousness due to the effects of physical stimuli given during the monitoring period and administered drugs. In some cases, the relationship has changed, and sufficient blood pressure monitoring accuracy cannot always be obtained within the blood pressure monitoring period.

The present invention has been made in view of the above circumstances, and an object of the present invention is to monitor a blood pressure value of a living body based on information on a velocity of a pulse wave propagating in an artery of the living body. It is an object of the present invention to obtain a high blood pressure monitoring accuracy in a blood pressure monitoring device.

[0005]

The present inventor has made various studies in view of the above circumstances, and as a result, among the fluctuation components of the heartbeat cycle, the relatively high frequency components substantially equal to the respiratory frequency of the living body have been obtained. Utilizing the fact that the heartbeat cycle fluctuation high-frequency component and the propagation velocity information fluctuation low-frequency component consisting of a relatively low frequency component lower than the living body's respiration frequency by a predetermined ratio are closely reflected in the autonomic nerve activity state of the living body. Then, it has been found that, when the correspondence is corrected based on the high frequency component of the heartbeat cycle fluctuation and the low frequency component of the propagation velocity information fluctuation, suitable blood pressure monitoring accuracy can be obtained. The present invention has been made based on such findings.

That is, the gist of the first aspect of the present invention is that the actual pulse wave propagation of the living body is determined from the correspondence between the blood pressure value of the living body and the value representing the pulse wave propagation velocity information of the living body. What is claimed is: 1. A blood pressure monitoring device for monitoring a blood pressure of a living body based on a value representing speed information, comprising: (a) a heartbeat cycle comprising a relatively high frequency component substantially equal to a respiration frequency of the living body based on a change in the heartbeat cycle of the living body; A heartbeat cycle variation high frequency component extracting means for extracting a variation high frequency component, and (b) a propagation speed comprising a relatively low frequency component lower than the respiration frequency of the living body by a predetermined ratio based on the variation of the value representing the pulse wave propagation speed information. A propagation speed information fluctuation low frequency component extraction means for extracting an information fluctuation low frequency component; and (c) a heartbeat cycle fluctuation high frequency component extracted by the heartbeat cycle fluctuation high frequency component extraction means and the transmission frequency information fluctuation low frequency component. Propagation velocity information is extracted by the velocity information fluctuation low frequency component extracting means varies based on the respective signal strength of the low-frequency component, and a correspondence relation modification means for modifying the relationship is to contain.

[0007]

In this way, the heartbeat cycle fluctuation high frequency component extracting means extracts the heartbeat cycle fluctuation high frequency component consisting of the frequency component substantially equal to the respiration frequency of the living body from the fluctuation of the heartbeat cycle of the living body, and the propagation speed. When the information fluctuation low frequency component extraction means extracts the propagation speed information fluctuation low frequency component consisting of a predetermined frequency component lower than the respiration frequency of the living body, the correspondence correcting means extracts the heart rate cycle fluctuation high frequency component and the propagation speed information. The correspondence is modified based on the respective signal strengths with the varying low frequency components. Therefore, when the signal strength of each of the high frequency component of the heartbeat cycle fluctuation and the low frequency component of the propagation speed information fluctuation changes, that is, when the state of the subject's autonomic nervous system changes, the corresponding response is made based on the change tendency. Since the relationship is corrected, an accurate blood pressure value can always be determined regardless of the state of the subject's autonomic nervous system.

[0008]

In another preferred embodiment of the present invention, the blood pressure monitoring device according to the first aspect of the present invention includes a blood pressure measuring means for measuring a blood pressure value of the living body using a cuff for pressing a part of the living body, Based on a predetermined relationship between the blood pressure value of the living body and the value representing the pulse wave propagation velocity information of the living body, the monitoring blood pressure value is sequentially determined based on the value representing the actual pulse wave propagation velocity information of the living body. Monitoring blood pressure value determining means, determining whether or not the monitoring blood pressure value sequentially determined by the monitoring blood pressure value determining means is an abnormal value exceeding a predetermined reference value; There is further provided monitoring blood pressure value abnormality determining means for starting blood pressure measurement by the blood pressure measuring means. According to this configuration, when the monitored blood pressure value abnormality determining means determines that the monitored blood pressure value is abnormal, the blood pressure measurement using the cuff by the blood pressure measuring means is started, so that the automatic monitoring is performed when the monitored blood pressure is abnormal. Since the blood pressure measurement value using the cuff is obtained, the reliability of blood pressure monitoring is further enhanced.

Preferably, a display is provided for displaying the monitored blood pressure value sequentially determined by the monitored blood pressure value determining means. With this configuration, by monitoring the blood pressure value displayed on the display, the blood pressure value of the living body can be continuously changed in a period in which the blood pressure measurement by the blood pressure measurement unit is not performed without imposing a pressure on the cuff. Can be monitored.

[0010]

A second aspect of the present invention to achieve the above object is to change the compression pressure of a cuff attached to a living body at a predetermined cycle,
Blood pressure measuring means for measuring a blood pressure value of the living body based on a change in the magnitude of a pulse wave generated in the process of changing the compression pressure; a first pulse wave detecting device mounted on two parts of the living body; Pulse wave velocity information calculating means for sequentially calculating a value representing pulse wave velocity information propagating through the artery of the living body based on the time difference of the pulse wave detection detected by the wave detecting device, and the pulse wave velocity Monitoring blood pressure value change determining means for initiating blood pressure measurement by the blood pressure measuring means based on a change value of a value representing pulse wave propagation velocity information calculated by the information calculating means exceeding a predetermined reference value And (a) extracting a heartbeat cycle fluctuation high frequency component consisting of a relatively high frequency component substantially equal to the respiration frequency of the living body from the heartbeat cycle fluctuation of the living body. A periodic variation frequency component extraction means,
(B) extracting a propagation speed information fluctuation low frequency component consisting of a relatively low frequency component lower than the respiration frequency of the living body by a predetermined ratio from the fluctuation of the value representing the pulse wave propagation speed information; Frequency component extracting means; and (c) a heart rate cycle fluctuation high frequency component extracted by the heart rate cycle fluctuation high frequency component extracting means and a propagation speed information fluctuation low frequency component extracted by the propagation speed information fluctuation low frequency component extracting means. Based on the respective signal strength, a determination correction means for correcting the determination by the monitoring blood pressure value change determination means,
To include.

[0011]

According to this configuration, the change value of the value representing the pulse wave propagation speed information sequentially calculated by the pulse wave propagation speed information calculating unit is determined by the monitoring blood pressure value change determining unit. The blood pressure measurement by the blood pressure measurement means is activated based on the fact that the reference value has been exceeded. At this time, the heartbeat cycle fluctuation high frequency component extraction means extracts a heartbeat cycle fluctuation high frequency component consisting of a frequency component substantially equal to the respiratory frequency of the living body from the fluctuation of the heartbeat cycle of the living body, and the propagation speed information fluctuation low frequency component extraction means extracts the living body. When the propagation speed information fluctuation low frequency component consisting of the predetermined frequency component lower than the respiration frequency is extracted, the judgment correcting means adds the signal intensity of each of the heartbeat cycle fluctuation high frequency component and the propagation speed information fluctuation low frequency component to each signal strength. The determination by the monitoring blood pressure value change determination means is corrected based on the determination. Therefore, when the signal strength of each of the high frequency component of the heartbeat cycle fluctuation and the low frequency component of the propagation speed information fluctuation changes, that is, when the state of the subject's autonomic nervous system changes, the monitored blood pressure is based on the change tendency. Since the determination by the value change determination means is corrected, it is possible to always monitor an accurate blood pressure value regardless of the state of the autonomic nerve of the subject.

[0012]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a block diagram illustrating a circuit configuration of a blood pressure monitoring device 8 to which the present invention has been applied.

In FIG. 1, a blood pressure monitoring device 8 has a rubber bag in a cloth band-shaped bag, for example, the upper arm 12 of a patient.
And a pressure sensor 14, a switching valve 16, and a cuff 10 connected to the cuff 10 via a pipe 20, respectively.
And an air pump 18. This switching valve 16
Switches between three states: a pressure supply state in which the supply of pressure into the cuff 10 is permitted, a slow discharge state in which the cuff 10 is gradually discharged, and a rapid discharge state in which the cuff 10 is rapidly discharged. It is configured to be.

The pressure sensor 14 detects the pressure in the cuff 10 and outputs a pressure signal SP representing the pressure to the static pressure discriminating circuit 2.
2 and the pulse wave discrimination circuit 24. The static pressure discriminating circuit 22 has a low-pass filter, discriminates a cuff pressure signal SK representing a steady pressure included in the pressure signal SP, that is, a cuff pressure, and converts the cuff pressure signal SK into an A / D converter 26.
To the electronic control unit 28 via the Pulse wave discrimination circuit 2
Reference numeral 4 denotes a band pass filter, which discriminates a pulse wave signal SM ₁ which is a vibration component of the pressure signal SP in frequency, and converts the pulse wave signal SM ₁ via the A / D converter 30 into the electronic control unit 2.
8 The cuff pulse wave represented by the pulse wave signal SM ₁ is
These are pressure vibration waves generated from a brachial artery (not shown) and transmitted to the cuff 10 in synchronization with the heartbeat of the patient.

The electronic control unit 28 includes a CPU 29, R
The microcomputer 29 includes a so-called microcomputer including an OM 31, a RAM 33, an I / O port (not shown), and the like. The CPU 29 executes signal processing using a storage function of the RAM 33 according to a program stored in the ROM 31 in advance. Thus, a drive signal is output from the I / O port to control the switching valve 16 and the air pump 18.

The electrocardiographic lead device 34 continuously detects an electrocardiogram, which is a so-called electrocardiogram, showing an action potential of the myocardium through a plurality of electrodes 36 attached to a predetermined portion of a living body. A signal SM ₂ indicating an electrocardiographic wave is supplied to the electronic control unit 28. It should be noted that the electrocardiographic guiding device 34
Is to detect the Q wave or the R wave of the electrocardiographic induction wave corresponding to the time when the blood in the heart starts to be pumped toward the aorta, that is, the pulse wave origin of the aortic internal pressure. , Function as a first pulse wave detection device.

The pulse oximeter photoelectric pulse wave detection probe 38 (hereinafter simply referred to as a probe) functions as a second pulse wave detection device for detecting a pulse wave transmitted to a peripheral artery including a capillary blood vessel. It is worn in close contact with a body surface 40 of a person to be measured, such as a fingertip, by a wearing band (not shown) or the like. The probe 38 is
A container-like housing 42 that opens in one direction, and a plurality of first light-emitting elements 44 _a that are provided on a portion located on the outer peripheral side of the inner surface of the bottom of the housing 42 and that include an LED or the like.
A light-emitting element 44 _b (hereinafter simply referred to as a light-emitting element 44 unless otherwise distinguished), a light-receiving element 46 provided at the center of the bottom inner surface of the housing 42 and including a photodiode or a phototransistor, and a housing 4.
2, a light emitting element 44 and a light receiving element 4
And a light-emitting element provided between the light-emitting element 44 and the light-receiving element 46 in the housing 42 and illuminated from the light-emitting element 44 toward the body surface 40. And an annular shielding member 50 that shields the reflected light toward 46.

[0018] The first light-emitting element 44 _a, for example 660
The second light emitting element 44 _b emits red light having a wavelength of about
Emits infrared light having a wavelength of about 800 nm, for example. The first light-emitting element 44 _a and the second light emitting element 44 _b, together are caused to emit light at a predetermined frequency for a predetermined time at a time order, from their light-emitting element 44 in the body of the light emitted toward the body surface 40 capillaries The reflected light from the area where the light is densely received is received by the common light receiving element 46. The wavelength of light emitted of the light emitting element 44 is not limited to the above values, the light absorption coefficient significantly different wavelength from the first light emitting element 44 _a is reduced oxyhemoglobin hemoglobin, the second light emitting element 44 _b is Any material may be used as long as it emits light having a wavelength having substantially the same absorption coefficient.

The light receiving element 46 outputs a photoelectric pulse wave signal SM ₃ having a magnitude corresponding to the amount of received light via a low-pass filter 52. An amplifier and the like are appropriately provided between the light receiving element 46 and the low-pass filter 52. Low pass filter 52 removes noise from the photoelectric pulse-wave signal SM ₃ input has a higher frequency than the frequency of the pulse wave, and outputs a signal SM ₃ whose noise has been removed to a demultiplexer 54. The photoelectric pulse wave represented by the photoelectric pulse-wave signal SM ₃ is a volume pulse wave generated in synchronism with the patient's pulse rate. This photoelectric pulse wave corresponds to the pulse synchronizing wave.

The demultiplexer 54 is connected to the electronic control unit 2
By being switched in synchronization with the emission of the first light-emitting element 44 _a and the second light emitting element 44 _b according to a signal from 8, an electric signal SM _R due to the red light through a sample hold circuit 56 and A / D converter 58 Then, an electric signal SM _IR by infrared light is sequentially supplied to an I / O port (not shown) of the electronic control device 28 via the sample hold circuit 60 and the A / D converter 62. When outputting the input electric signals SM _R , SM _IR to the A / D converters 58, 62, the sample hold circuits 56, 60 convert the A / D converters for the previously output electric signals SM _R , SM _IR . 58,
By the time the conversion operation at 62 is completed, the electric signals SM _R and SM _IR to be output next are respectively held.

The CPU 29 of the electronic control unit 28 has a RAM
The measurement operation is performed according to a program stored in the ROM 31 in advance while utilizing the storage function of the drive circuit 64.
Emitting element 44 outputs a control signal SLV to _a, 44 one for sequentially for a predetermined time increments emission at a predetermined frequency _b, their light-emitting element 44 _a, 44 _b switching signal S in synchronization with the emission of
By switching the demultiplexer 54 outputs the C, sample and hold circuit 56 to the electric signal SM _R
Then, the electric signal SM _IR is distributed to the sample and hold circuit 60. The CPU 29 calculates the blood oxygen saturation of the living body based on the amplitude values of the electric signals SM _R and SM _IR from an arithmetic expression stored in advance to calculate the blood oxygen saturation. As a method of determining the oxygen saturation, for example, a determination method described in Japanese Patent Application Laid-Open No. H3-15440, which was previously filed by the present applicant, is used.

FIG. 2 is a functional block diagram for explaining a main part of the control function of the electronic control unit 28 in the blood pressure monitoring device 8. In FIG. 2, after the cuff pressure control means 72 rapidly increases the compression pressure of the cuff 10, for example, to a predetermined target pressure value P _CM (for example, a pressure value of about 180 mmHg), the blood pressure measurement means 70 sets the pressure to about 3 mmHg / sec. During the gradual step-down period in which the blood pressure is gradually lowered at a predetermined speed, the systolic blood pressure value B is determined using a well-known oscillometric method based on a change in the amplitude of the pulse wave represented by the pulse wave signal SM ₁ sequentially sampled.
P _SYS and the diastolic blood pressure value BP _DIA are determined.

As shown in FIG. 3, the pulse wave propagation velocity calculating means 74 which functions as pulse wave propagation velocity information calculating means is a predetermined pulse wave generation cycle which is sequentially detected by the electrocardiographic guiding apparatus 34 and is generated at every cycle. A time difference calculating means for sequentially calculating a time difference (propagation time) TD _RP from a region, for example, an R wave, to a predetermined region, for example, a rising point or a lower peak point, which is generated in each cycle of the photoelectric pulse wave sequentially detected by the probe 38; Based on the time difference TD _RP sequentially calculated by the time difference calculating means, the propagation velocity V _M (m / sec) of the pulse wave propagating in the artery of the subject is sequentially calculated from Equation 1 stored in advance. . The sequentially calculated propagation speed V _M includes:
There is a variation as shown in FIG. In equation (1), L (m) is the distance from the left ventricle via the aorta to the site where the probe 38 is mounted, and T _PEP (se
c) is a pre-ejection period from the R wave of the electrocardiographic lead waveform to the lower peak point of the aortic root pulse wave. The distance L and the pre-ejection period T _PEP are constants, and values experimentally obtained in advance are used.

[0024]

[Number 1] _{V M = L / (TD RP} -T PEP)

The propagation speed blood pressure correspondence relationship determining means 76, which functions as the propagation speed information blood pressure correspondence relationship determining means, includes the systolic blood pressure value BP _SYS measured by the blood pressure measuring means 70 and the propagation speed V _M within each blood pressure measurement period. For example, based on the average value of the propagation velocity V _M during that period,
The coefficients A and B in the relational expression between the propagation speed V _M and the systolic blood pressure value BP _SYS represented by Expression 2 are also calculated, and the diastolic blood pressure value BP _DIA similarly measured by the blood pressure measuring means 70 and the propagation speed during the blood pressure measurement period. Based on V _M , the coefficients C and D in the relational expression between the propagation speed V _M and the diastolic blood pressure value BP _DIA represented by Expression 3 are determined in advance.

[0026]

BP _SYS = A (V _M ) α + B

[0027]

## _EQU3 ## BP _DIA = C (V _M ) α + D

The monitoring blood pressure value determining means 78 is sequentially calculated by the pulse wave propagation velocity calculating means 74 from the correspondence (Equation 2 and Equation 3) between the blood pressure value of the living body and the pulse wave propagation velocity of the living body. that living based on the actual pulse wave velocity V _M successively determine the monitoring blood pressure value MBP _SYS and MBP _DIA, displays respectively it on the display unit 32. The monitoring blood pressure value abnormality determining means 80 determines whether or not the monitoring blood pressure value MBP _SYS sequentially determined by the monitoring blood pressure value determining means 78 is an abnormal value exceeding a predetermined reference value.
When an abnormal value is determined, the blood pressure measurement operation using the cuff 10 by the blood pressure measurement means 70 is started.

The heartbeat cycle fluctuation high frequency component extraction means 82
A cardiac cycle calculating means for continuously calculating the cardiac cycle T _{RR of the} living body for each beat from the time interval of the electrocardiographic guided waves of the living body sequentially detected by the electrocardiographic guiding device 34, for example, the time interval between R waves is provided. . The cardiac cycle T _RR has a variation as shown in FIG. From changes in the pulse period T _RR, as shown in FIG. 5, for sequential extraction pulse period fluctuation high frequency component HFC ₁ consisting substantially equal to the frequency component with the respiratory frequency of the living body. Further, the propagation velocity fluctuation low frequency component extracting means 84 which functions as a propagation velocity information fluctuation low frequency component extraction means, from changes in the propagation velocity V _M of the continuously calculated vivo by the pulse wave velocity calculation means 74, as shown in FIG. 5, sequentially extracting a predetermined ratio that is lower propagation velocity fluctuation low frequency component LFC ₂ than breathing frequency of the living body. The heartbeat cycle fluctuation high frequency component extraction means 82 and the propagation velocity fluctuation low frequency component extraction means 84 include, for example, a fast Fourier transform (FF).
T) method or frequency analysis of the pulse period T _RR and propagation velocity V _M by using a autoregressive (AR) method. Note that the low-frequency component extracted from the fluctuation of the blood pressure values continuously measured, that is, from the known fact that the variation of the propagation velocity V _M is equal to approximately the variation of continuously measured monitored blood pressure values, the propagation low frequency components LF extracted from changes in velocity V _M
C ₂ quantitatively represents the sympathetic nerve activity of the living body, and the high frequency component H extracted from the fluctuation of the cardiac cycle T _RR.
FC ₁ is quantitatively represents the activity of the parasympathetic biological.

The correspondence correcting means 86 is adapted to change the heartbeat cycle.
Dynamic high-frequency component extraction means 82 and propagation speed fluctuation low-frequency component
Of the living body, which are sequentially extracted by the
Cardiac cycle, a quantitative indicator of parasympathetic activity
Variable high frequency component HFC₁ And the sympathetic activity of the living body
Velocity fluctuation low frequency component LF, which is an index quantitatively expressing
C_Two , For example, their signal strength ratio SR [=
LFC_Two / HFC₁ ] Or signal strength difference SD [= LFC
_Two -HFC₁ ] Is calculated sequentially, and one cycle of the comparison value is calculated.
Change between the previously calculated comparison value and the currently calculated comparison value
Amount ΔSR [SR _n-SR_n-1 ] Or ΔSD [= SD
_n-SD_n-1 ], For example, as shown in FIG.
From the table, the propagation velocity V represented by the equation (2)_MAnd systolic blood pressure
Value BP_{SY S}The correction coefficient α of the relational expression with
Propagation speed V_MAnd diastolic blood pressure BP_DIAOf the relational expression
The correction coefficient α is determined. The function shown in FIG.
Is determined experimentally in advance, and ΔSR, α,
Is shown by a solid line, and the relationship between ΔSD and α is shown by a broken line.
I have.

FIG. 7 is a flowchart for explaining a main part of the control operation in the electronic control unit 28 of the blood pressure monitoring device 8. In FIG. 7, after an initial process of clearing a counter and a register (not shown) is performed in step SA1 (hereinafter, steps are omitted), in SA2 corresponding to the pulse wave propagation velocity calculating means 74, in the cuff boosting period, The time difference from the R wave of the electrocardiographic waveform to the rising point of the photoplethysmogram sequentially detected by the probe 38, that is, the propagation time TP (= TD _RP −T _PEP ), is determined. Pulse wave velocity V _M
(M / sec) is calculated immediately before the cuff pressure rise.

Next, at SA3 corresponding to the cuff pressure control means 72, the switching valve 16 is switched to the pressure supply state and the air pump 18 is driven, so that the cuff 10 is rapidly increased in pressure for blood pressure measurement. Is done.

SA4 corresponding to the subsequent cuff pressure control means 72
Then, cuff pressure P_CIs preset to about 180mmHg
Target pressure P_cmIt is determined whether or not the above has been achieved. This S
If the judgment of A4 is denied, the above SA2 and below are repeated.
Cuff pressure P_CContinues to rise
You. However, the cuff pressure P_COf the above SA4 due to the rise of
Is affirmative, the SA corresponding to the blood pressure measuring means 70 is
At 5, the blood pressure measurement algorithm is executed. sand
That is, the air pump 18 is stopped, and the switching valve 16 is gradually moved.
By switching to the exhaust pressure state, the pressure in the cuff 10 is determined in advance.
By lowering at a gentle speed of about 3 mmHg / sec.
And the pulse wave signal SM sequentially obtained in this slow down process.₁ But
Based on the change in the amplitude of the pulse wave
Best according to metric blood pressure determination algorithm
Blood pressure value BP_SYS, Mean blood pressure value BP _MEAN, And diastolic blood pressure
Value BP_DIAIs measured and based on the pulse interval
The pulse rate and the like are determined. And its measured
The displayed blood pressure value and pulse rate are displayed on the display 32.
At the same time, the switching valve 16 is switched to the rapid exhaust pressure state.
The pressure inside the cuff 10 is rapidly exhausted.

[0034] Next, in SA6 corresponding to the propagation velocity relationship between blood pressure determining means 76, and the pulse wave propagation velocity V _M obtained in SA2, the cuff was measured at SA5 1
A correspondence between the blood pressure values BP _SYS , BP _MEAN , or BP _DIA by 0 is determined. That is, when the blood pressure values BP _SYS , BP _MEAN , and BP _DIA are measured in SA5, the blood pressure values BP _SYS , BP _MEAN , or BP
With one of out of _DIA, based on the pulse wave velocity V _M,
The correspondence (Equation 2, Equation 3) between the pulse wave velocity V _M and the monitored blood pressure value MBP is determined.

When the propagation speed blood pressure correspondence is determined as described above, it is determined in SA7 whether the R wave of the electrocardiographic lead waveform and the photoelectric pulse wave have been input. This S
If the determination of A7 is denied, SA7 is repeatedly executed. If the determination is affirmed, in SA8 corresponding to the pulse wave propagation velocity calculation means 74, the R wave of the newly input electrocardiographic lead waveform and pulse wave velocity V _M of the photoelectric pulse wave is calculated in the same manner as SA2.

[0036] In SA9 corresponding to the monitor-blood-pressure determining means 78, from the propagation velocity relationship between blood pressure determined in the above SA6, based on the pulse wave velocity V _M obtained in the above SA8, monitoring blood pressure MBP (The systolic blood pressure value and / or the diastolic blood pressure value) is determined, and is output to the display 32 in order to display the monitor blood pressure value MBP for each beat in a trend display.

Next, the monitoring blood pressure value abnormality judging means 80
In SA10 corresponding to, it is determined whether or not the monitored blood pressure value MBP determined in SA9 has exceeded a predetermined reference range. If the determination in SA10 is denied, SA11 is executed, but if affirmed, S11 is executed.
After the blood pressure abnormality is displayed on the display 32 in A12, SA2 is used to re-determine the propagation speed blood pressure correspondence.
The following is performed again.

In SA11, the cuff 1 in SA5 is used.
It is determined whether or not the elapsed time since the blood pressure measurement by 0 has been performed has passed a preset cycle of about 15 to 20 minutes, that is, a calibration cycle. This S
If the determination in A11 is negative, the blood pressure monitoring routine of SA7 and below is repeatedly executed, and the monitored blood pressure value MB
P is determined continuously for each beat, and the determined monitored blood pressure value MBP is displayed on the display unit 32 in a time-series trend display. However, if the determination in SA11 is affirmative, the SA is re-determined to determine the correspondence.
Two or less cuff calibration routines are executed again.

FIG. 8 shows a relation correction routine executed in parallel with FIG. At SB1 in FIG. 8, it is determined whether or not the R wave of the electrocardiographically guided wave sequentially detected from the electrocardiographically guiding device 34 is detected. If this determination is denied, SB4 and subsequent steps are executed. However, if the determination at SB1 is affirmative, at SB2 and SB3 corresponding to the heartbeat cycle fluctuation high frequency component extraction means 82,
The cardiac cycle T _{RR of the} living body is sequentially calculated from the time interval of the electrocardiographic guided waves of the living body sequentially detected by the electrocardiographic guiding device 34, for example, the time interval between R waves, and the heart rate within a predetermined section obtained up to that time is calculated. from changes in the period T _RR, pulse period fluctuation high frequency component HFC ₁ consisting substantially equal to the frequency component with the respiratory frequency of the living body, it is sequentially extracted by fast Fourier transform (FFT) method or an autoregression (AR) method.

Next, at SB4, it is determined whether or not one photoplethysmogram is detected from the probe 38. This SB
If the determination of No. 4 is denied, this routine is ended. However, if the determination at SB4 is affirmative, at SB5 and SB6 corresponding to the propagation speed fluctuation low frequency component extraction means 84, based on the time difference TD _RP between the R wave and the rising point of the photoelectric pulse wave, From the equation 1 stored in advance, the propagation velocity V _{M of} the pulse wave propagating in the artery of the living body is obtained.
Is calculated and, for example, the fast Fourier transform (F
By using the FT) method or the auto-regression (AR) method, the propagation velocity V _{M of} the predetermined section determined so far is used.
Variation of by being frequency analysis, the propagation velocity fluctuation low frequency component LFC ₂ having a predetermined frequency components lower than the breathing frequency of the living body is extracted.

Next, at SB7 corresponding to the correspondence correcting means 86, the heartbeat cycle fluctuation high frequency component HFC ₁
Value of the transmission speed fluctuation low frequency component LFC _{2, that} is, the ratio SR [= LFC ₂ / HFC of the respective signal intensities]
₁ ] or the difference SD [= LFC ₂ −HFC ₁ ] and the change ΔSR [= SR _n −SR _n−1 ] or ΔS between the previously calculated comparison value and the currently calculated comparison value.
Based on D [= SD _n −SD _n−1 ], for example, the coefficient α in Equations 2 and 3 stored in advance is determined from the relationship shown in FIG.

As described above, according to the present embodiment, the cardiac cycle
SB2, SB3 corresponding to the variable high-frequency component extraction means 82
, The cardiac cycle TD of the living body_RPOf the living body from the fluctuation of the body
Heart rate fluctuation high frequency composed of frequency components approximately equal to frequency
Wave component HFC₁ Is extracted, and the low-frequency component
At SB5 and SB6 corresponding to the output means 84,
Propagation speed V_MFrom the fluctuation of the living body
Low propagation velocity fluctuation low frequency component LFC_Two Is extracted
Then, at SB7 corresponding to the correspondence relation correcting means 86,
These heartbeat cycle fluctuation high frequency components HFC₁ And propagation speed
Variable low frequency component LFC_Two Of the signal strength of each
Is a means for determining the blood pressure correspondence relation based on the change in the difference.
Blood pressure value MBP determined by SA6 corresponding to step 76
And propagation speed V_MIs corrected. Accordingly
, Heart rate cycle fluctuation high frequency component HFC ₁ And propagation speed variation
Dynamic low frequency component LFC_Two Of the signal strength of each
If the difference changes, that is, the state of the subject's autonomic nervous system
If the status has changed, the response
Since the relationship is corrected, the state of the subject's autonomic nervous system
It is possible to always determine an accurate blood pressure value regardless of
You.

Further, according to the present embodiment, when the monitored blood pressure value determining means 80 (SA10) determines that the monitored blood pressure value sequentially determined by the monitored blood pressure value determining means 78 is abnormal, the blood pressure measurement is performed. Since the blood pressure measurement using the cuff 10 by the means 70 is started, the blood pressure measurement value using the cuff is automatically obtained when the monitored blood pressure is abnormal, so that the reliability of the blood pressure monitoring is further enhanced.

Further, according to the present embodiment, since the display device 32 for displaying the monitored blood pressure value sequentially determined by the monitored blood pressure value determining means 78 is provided, the monitored blood pressure value displayed on the display device 32 is displayed. It can be seen that the blood pressure measuring means 70
During the period in which the blood pressure measurement is not performed, the blood pressure value of the living body can be continuously monitored without imposing a load due to the compression of the cuff 10.

Next, another embodiment of the present invention will be described in detail with reference to the drawings. Note that portions having the same configuration as the above embodiment are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 9, FIG. 10 and FIG. 11 are a functional block diagram and a flow chart for explaining a main part of a blood pressure monitoring apparatus according to an embodiment corresponding to the second invention. In the blood pressure monitoring device of this embodiment, the mechanism and circuit configuration of the device are common to those of the above-described embodiment of FIG. 1, but the blood pressure monitoring method by the electronic control device 28 is different. That is, in the blood pressure monitoring device of the present embodiment, while the blood pressure measurement using the cuff 10 to a preset pressure determined for each period T _B is performed in the measurement period wherein the blood pressure measurement is not performed, the pulse wave velocity V _M change value [Delta] V _M monitors the blood pressure fluctuation based on whether exceeds a predetermined determination reference value gamma, change value [Delta] V _M is the predetermined determination reference value gamma
If it is determined that the measured value has exceeded the threshold value, the blood pressure measurement by the cuff 10 is executed to obtain the latest blood pressure measurement value.

FIG. 9 is a functional block diagram for explaining a main control function of the electronic control unit 28 in the blood pressure monitoring apparatus according to the present embodiment. In the figure, the blood pressure measuring means 70 executes the blood pressure measurement operation using the cuff 10 by the blood pressure measurement is started at a preset blood pressure measurement for each period T _B,
The blood pressure value displayed on the display 32 is updated. Propagation velocity change value calculating means 88 which functions as the propagation speed information-change-value determining means calculates a change value [Delta] V _M of the pulse wave propagation velocity V _M calculated for each one heartbeat by pulse wave velocity calculation means 74.
This change value ΔV _M is calculated by, for example,
Successively by pulse wave velocity V _M moving average value V _{M AV} or blood pressure measuring means 70 as determined by 4 is a rate of change or variation with respect to the pulse wave velocity V _M at the time when the last blood pressure measurement is performed. Monitoring blood pressure change determining means 90, the living body based on the change value [Delta] V _M of the pulse wave propagation velocity V _M calculated by the propagation velocity change value calculating means 88 exceeds a γ preset determination reference value The blood pressure change is determined by determining the blood pressure change, displaying the change in the blood pressure of the living body on the display device 32, and obtaining a blood pressure measurement value using the cuff 10.
Of the blood pressure measurement operation is started. That is, the monitoring blood pressure change determining means 90, the change value ΔV of the pulse wave propagation velocity V _M
It also functions as an activation unit that activates the blood pressure measurement operation of the blood pressure measurement unit 70 when _M exceeds a preset judgment reference value γ.

The judgment correcting means 92 comprises a heartbeat cycle fluctuation high frequency component HFC ₁ extracted by the heartbeat cycle fluctuation high frequency component extraction means 82 and the propagation speed fluctuation low frequency component extraction means 8.
The determination by the monitoring blood pressure value change determination means 90 is corrected based on the respective signal intensities with the propagation speed fluctuation low frequency component LFC ₂ extracted by the step 4. Judgment correction means 92
, For example the cardiac cycle fluctuations high frequency component HFC ₁ and the ratio of the comparative value, that each of the signal strength and propagation velocity fluctuation low frequency component LFC ₂ SR [= LFC ₂ / HFC _1], or the difference between SD [= LFC ₂ -HFC ₁ ], And the variation Δ between the previously calculated comparison value and the currently calculated comparison value.
SR [= SR _n −SR _n−1 ] or ΔSD [= SD _n −
SD _n−1 ], the criterion value γ is corrected.

FIG. 10 is a flowchart for explaining the main part of the control operation of the electronic control unit 28 of the present embodiment. In the figure, after the same initial processing as that of SA1 is performed in SC1, it is determined in SC2 whether the R wave and the photoplethysmogram of the electrocardiographic lead waveform have been generated. If the determination in SC2 is negative, in SC3, the previous whether preset blood pressure measurement period T _B from the blood pressure measurement has elapsed with cuff by SC8 is determined. This blood pressure measurement cycle T _B is set to a relatively long time, for example, from ten minutes to several tens of minutes. If the determination at SC3 is denied, this routine is terminated, and the steps below SC1 are repeatedly executed. However, if the determination is affirmed, the blood pressure measurement period periodically arrives. In SC8 corresponding to the above, the blood pressure measurement is performed by the oscillometric method using the cuff 10, whereby the systolic blood pressure value BP _SYS and the diastolic blood pressure value BP _DIA are determined and displayed, and then this routine is ended. .

When the determination at SC2 is affirmative, S
At C4, the R wave and the photoelectric pulse wave of the electrocardiographic lead waveform are read, and the pulse wave propagation velocity calculating means 7 is read.
In SC5 corresponding to 4, pulse wave velocity V _M is calculated in the same manner as in SA8. Then, in the SC6 corresponding to the propagation speed change value calculating means 88, the change value [Delta] V _M of the pulse wave velocity V _M is calculated. This change value ΔV _M
As it is, the moving average value PWV _AV [= V _{M in} + ··· +
V _{M i-1} + V _{M i} / (n + 1)] (= V
_{M i} −V _{M AV} ) or change rate [= (V _{M i} −V _{M AV} )
/ V _{M AV} ] or the amount of change with respect to the pulse wave velocity V _{M m} (= V
_{M i} −V _{M m} ) or the rate of change [= (V _{M i} −V _{M m} )
/ V _{M m} ].

The monitoring blood pressure value change determining means 90
In corresponding SC7 to whether the change value [Delta] V _M of the pulse wave velocity V _M is preset criterion value γ or is determined. The judgment reference value γ is experimentally obtained in advance in order to judge whether or not the blood pressure value of the patient has changed to a problem in monitoring the condition of the living body.

If the determination in SC7 is negative, the blood pressure value of the patient is stable, so that the blood pressure measurement using the cuff 10 in SC8 is not performed, and the processes in SC3 and below are performed. However, if the determination of SC7 is affirmed, the blood pressure value of the patient has changed relatively largely, and thus the blood pressure measurement using the cuff 10 of SC8 is started immediately, and a character indicating the change in the monitored blood pressure value is displayed. Alternatively, the sign and the blood pressure value measured using the cuff 10 are displayed on the display 36.

FIG. 11 is a flowchart showing the parallel operation of the routine shown in FIG.
This is a determination correction routine executed in step (a). SD1 in FIG.
8 are executed in the same manner as SB1 to SB6 in FIG.
It is. In SD7 corresponding to the judgment correcting means 92, the heartbeat
SD3 corresponding to the period variation high frequency component extraction means 82
The extracted high frequency component of heart rate fluctuation HFC₁ And said propagation
According to SD6 corresponding to the speed fluctuation low frequency component extraction means 84
Extracted low-frequency component of propagation velocity fluctuation LFC_Two With it
Based on the respective signal intensities, the monitoring blood pressure value change determination
Correct the decision made by step 90. For example, heart rate fluctuation
Frequency component HFC ₁ And low velocity component LFC_Two When
, Ie, the ratio SR [= LF of the respective signal intensities.
C_Two / HFC₁ ] Or difference SD [= LFC_Two -HFC
₁ ] Between the value calculated last time and the value calculated this time.
Change amount ΔSR [= SR_n-SR_{n- 1} ] Or ΔSD [=
SD_n-SD_n-1 ], For example, the same as FIG.
The criterion value γ is corrected from the relationship.

According to the present embodiment, a method for calculating a propagation speed change value is described.
In step 88 (SC6), the pulse wave propagation velocity calculating means 74
Pulse wave velocity V calculated by (SC5)_MChange value of
ΔV_MIs calculated, the monitoring blood pressure value change determining means 90
By (SC7), the propagation speed change value calculating means 88
Pulse wave velocity V calculated from_MChange value ΔV_MBut in advance
Based on exceeding the set judgment reference value γ,
The blood pressure change is determined, and the SC corresponding to the blood pressure measurement unit 70 is determined.
At 8, the blood pressure measurement using the cuff 10 is immediately performed.
The measured blood pressure value is displayed on the display 32. this
At this time, the heartbeat cycle fluctuation high frequency component extraction means 82 (SD2,
SD3), the heartbeat cycle TD of the living body_RPOf the biological
Heart rate variability consisting of frequency components approximately equal to the respiratory frequency
High frequency component HFC₁ Is extracted, and the
Speed of the living body by the minute extraction means 84 (SD5, SD6)
Propagation velocity V as degree information_MOf the living body from the fluctuation of the body
Velocity fluctuation low frequency component LFC lower by a predetermined ratio than
_Two Is extracted, the judgment correcting means means 92 (SD7)
Thus, the determination by the monitoring blood pressure value change determination means 90 is corrected.
The high frequency component of the heartbeat cycle fluctuation HFC₁ And propagation
Speed fluctuation low frequency component LFC _Two Signal strength of each
In other words, the state of the subject's autonomic nervous system changes.
Changes in the monitored blood pressure value based on the
Since the determination by the conversion determination means 90 is corrected,
Always monitor accurate blood pressure values regardless of the state of the autonomic nervous system
It becomes possible to do.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be applied to other embodiments.

For example, in the above embodiment, the pulse wave velocity V _M is used as the pulse wave velocity information, and the correspondence with the blood pressure value, the monitored blood pressure value, and the like are determined. no problem even using the time difference to a predetermined portion from the R wave of the ECG waveform occurs every cycle of the photoelectric pulse wave corresponding to the one-to-one (pulse wave propagation time) TD _RP as pulse wave velocity information. In this case, for example, the time difference _TDRP is calculated by the pulse wave propagation time calculation means (time difference calculation means) instead of the pulse wave propagation velocity calculation means 74 of FIG. In addition, instead of the propagation speed blood pressure correspondence relation determining means 76, a propagation time blood pressure correspondence relation determination means is used, and based on Equations 4 and 5, the propagation time TD _RP and the systolic blood pressure value BP _SYS or the diastolic blood pressure value BP _DIA are calculated. _Is determined, and the monitored blood pressure value determining means 78 determines the monitored blood pressure value from the corresponding relationship based on the propagation time TDRP. In addition, instead of the propagation speed fluctuation low frequency component extraction means 84, the propagation time fluctuation low frequency component extraction means is used, so that the propagation time fluctuation low frequency component LFC ₂ ′ is extracted as the propagation speed information fluctuation low frequency component. The relation correcting means 86 corrects the correspondence between the propagation time TD _RP and the blood pressure value. Note that the propagation time variation low frequency component LFC ₂ ′ extracted here is substantially the same as the propagation speed variation low frequency component LFC ₂ because the propagation speed and the propagation time have a one-to-one correspondence.

[0057]

BP _SYS = A ((L / (TD _RP −T _PEP )) α + B

[0058]

BP _DIA = C ((L / (TD _RP −T _PEP )) α + D

In this case, also in other embodiments,
For example, the time difference _TDRP is calculated by a pulse wave propagation time calculation means (time difference calculation means) instead of the pulse wave propagation velocity calculation means 74 in FIG. Moreover, the propagation time variation value calculating means is used in place of the propagation velocity change value calculating means 88, the change value Delta] TD _RP propagation time TD _RP is calculated, the change value of the propagation time TD _RP in monitoring blood pressure change determining means 90 ΔTD
_It is determined whether or not _RP has exceeded a criterion value γ ′.
Further, instead of the propagation speed fluctuation low frequency component extraction means 84, a propagation time fluctuation low frequency component extraction means is used, and the propagation time fluctuation low frequency component LFC ₂ ′ is extracted. 'Is modified.

In the embodiment shown in FIG. 2, the correspondence correcting means 86 calculates the correction coefficient α contained in the propagation velocity blood pressure correspondence shown in the equations (2) and (3) from the relationship shown in FIG. Although there was intended to modify based a component HFC ₁ the propagation speed fluctuation low frequency component LFC _2, no problem even as to advance correcting the propagation velocity V _M which is used in equation 2 and equation 3.

In the embodiment shown in FIG. 9, the judgment correcting means 92 sets the judgment reference value γ used in the monitoring blood pressure value change judgment means 90 to the heartbeat cycle fluctuation high frequency component HF.
Although the correction is made based on C ₁ and the propagation speed fluctuation low frequency component LFC ₂ , the monitoring blood pressure value change determination means 90
No problem even intended to correct beforehand the propagation velocity V _M to be used in.

In the above-described embodiments of FIGS. 8 and 11,
Although the cardiac cycle varies from the R-wave and the photoelectric pulse wave is generated high-frequency component HFC ₁ and propagation velocity fluctuation low frequency component LFC ₂ has been extracted, R-wave and the photoelectric pulse wave of a predetermined number are extracted for each generated You may make it.

In the above-described embodiment, the electrocardiographic lead-in device 3
Although the device 4 functions as the first pulse wave detection device, another type such as a pulse wave sensor that presses the carotid artery to detect a pulse wave may be used.

Further, in the above-described embodiment, the photoelectric pulse wave detecting probe 38 for the oximeter functions as the second pulse wave detecting device. However, the cuff 10 detects the cuff pulse wave from the cuff 10 holding the predetermined pressure. A pulse wave sensor, a pressure pulse wave sensor for detecting a pulse wave by pressing a radial artery, an impedance pulse wave sensor for detecting the impedance of an arm or a fingertip through an electrode, and a photoelectric pulse wave attached to a fingertip for detecting a photoelectric pulse wave Other types, such as a type of photoelectric pulse wave sensor, may be used.

[0065] Further, in the embodiment described above, the pulse wave velocity V _M had been calculated on the basis of the time difference to the rising point of the photoelectric pulse wave from the R-wave, the electrocardiographic waveform from the Q wave of the photoelectric pulse wave Other calculation methods such as using a time difference up to the rising point are used.

In the above-described embodiment, the blood pressure is monitored for each beat of the R wave or the photoelectric pulse wave. However, the blood pressure may be monitored for every two or more beats.

The present invention can be modified in various other ways without departing from the gist thereof.

[Brief description of the drawings]

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

FIG. 2 is a functional block diagram illustrating a main part of a control function of an electronic control device in the embodiment of FIG. 1;

FIG. 3 is a diagram illustrating a time difference TD _RP obtained by a control operation of the electronic control device 28 in the embodiment of FIG. 1;

4 is a diagram illustrating a variation of the propagation velocity V _M and pulse period T _RR obtained by the control operation of the electronic control device 28 in the embodiment of FIG.

[5] cardiac cycle fluctuations variations in propagation velocity V _M and pulse period T _RR obtained by the control operation of the electronic control device 28 is extracted by being frequency analysis in the embodiment of FIG. 1 high frequency component HFC ₁ and propagation Speed fluctuation low frequency component LF
It is a diagram illustrating a C _2.

[6] corresponding relationship and correction value α for correcting, pulse period fluctuation high frequency component HFC ₁ and the signal intensity ratio of the propagation velocity fluctuation low frequency component LFC ₂ that is previously calculated with propagation velocity V _M and blood pressure BP It is a figure which illustrates the relationship with the change amount (DELTA) SR of SR, or the change amount (DELTA) SD of the signal strength difference SD. In the drawing, the relationship between the change amount ΔSR and the correction value α is indicated by a solid line, and the relationship between the change amount ΔSD and the correction value α is indicated by a broken line.

FIG. 7 is a flowchart illustrating a main part of a control operation of the electronic control device in the embodiment of FIG. 1, and is a diagram illustrating a blood pressure monitoring routine.

8 is a flowchart illustrating a main part of the control operation of the electronic control unit 28 in the embodiment of FIG. 1, and is a diagram illustrating a relation correction routine.

FIG. 9 shows an electronic control unit according to another embodiment of the present invention.
FIG. 3 is a functional block diagram for explaining a main part of the control function of FIG.

FIG. 10 is a flowchart illustrating a main part of a control operation of the electronic control device in the embodiment of FIG. 9, and is a diagram illustrating a blood pressure monitoring routine.

11 is a flowchart illustrating a main part of a control operation of the electronic control device in the embodiment of FIG. 9, and is a diagram illustrating a blood pressure change determination correction routine.

[Explanation of symbols]

 70: blood pressure measuring means 74: pulse wave propagation velocity calculating means 76: propagation velocity blood pressure correspondence relation determining means 78: monitoring blood pressure value determining means 80: monitoring blood pressure abnormality determining means 82: heart rate cycle fluctuation high frequency component extracting means 84: propagation velocity fluctuation Low frequency component extraction means 86: Correspondence correction means 88: Propagation velocity change value calculation means 90: Monitoring blood pressure value change determination means 92: Determination correction means

Claims (3)

[Claims] An actual pulse wave velocity information of a living body is represented from a predetermined relationship between a blood pressure value of the living body and a value representing pulse wave velocity information related to the pulse wave velocity of the living body. A blood pressure monitoring device that monitors the blood pressure of the living body based on the value, and extracts a heartbeat cycle fluctuation high frequency component including a relatively high frequency component substantially equal to the respiration frequency of the living body from the heartbeat cycle variation of the living body. Heartbeat cycle fluctuation high frequency component extraction means, and from the fluctuation of the value representing the pulse wave propagation velocity information, a propagation velocity information fluctuation low frequency component comprising a relatively low frequency component lower than the respiration frequency of the living body by a predetermined ratio. Extraction means for extracting low-frequency component of propagation speed information fluctuation, extraction of high-frequency component of heartbeat cycle fluctuation extracted by the high-frequency component of heartbeat cycle fluctuation and extraction means for low-frequency component of propagation speed information fluctuation. A blood pressure monitoring device, comprising: a correspondence correction unit that corrects the correspondence based on the respective signal intensities of the output propagation speed information fluctuation low frequency components. 2. A blood pressure measuring means for measuring a blood pressure value of the living body using a cuff for compressing a part of the living body, and a blood pressure value of the living body and a value representing pulse wave propagation velocity information of the living body in advance. A monitoring blood pressure value determining means for sequentially determining a monitoring blood pressure value based on a value representing actual pulse wave propagation velocity information of the living body from the obtained correspondence, and a monitoring blood pressure sequentially determined by the monitoring blood pressure value determining means. It further includes monitoring blood pressure value abnormality determining means for determining whether or not the value is an abnormal value exceeding a predetermined reference value, and when determining the abnormal value, activating blood pressure measurement by the blood pressure measuring means. The blood pressure monitoring device according to claim 1. 3. A blood pressure for changing a compression pressure of a cuff attached to a living body at a predetermined cycle, and measuring a blood pressure value of the living body based on a change in a magnitude of a pulse wave generated in the process of changing the compression pressure. A pulse wave propagation velocity propagating through an artery of the living body based on measuring means and a time difference between pulse wave detections detected by the first pulse wave detecting device and the second pulse wave detecting device attached to the two parts of the living body, respectively. Pulse wave propagation speed information calculating means for sequentially calculating a value representing pulse wave propagation speed information related to, and a change value of the value representing the pulse wave propagation speed information calculated by the pulse wave propagation speed information calculating means, A monitoring blood pressure value change determining unit that activates blood pressure measurement by the blood pressure measuring unit based on exceeding a set determination reference value, the blood pressure monitoring device comprising: Respiratory frequency and Heartbeat cycle variation high frequency component extraction means for extracting a heartbeat cycle variation high frequency component composed of equal relatively high frequency components, and comparing the variation representing the pulse wave propagation velocity information with a predetermined rate lower than the respiration frequency of the living body. Propagation speed information fluctuation low frequency component extracting means for extracting a propagation speed information fluctuation low frequency component composed of a typical low frequency frequency component; heart rate cycle fluctuation high frequency component extracted by the heart rate cycle fluctuation high frequency component extracting means; Determination correction means for correcting the determination by the monitoring blood pressure value change determination means based on the respective signal intensities with the propagation speed information fluctuation low frequency component extracted by the information fluctuation low frequency component extraction means, Blood pressure monitoring device.