JPH08187227A - Apparatus for continuously monitoring blood pressure - Google Patents

Abstract

PURPOSE: To provide an apparatus for continuously monitoring a blood pressure, which lightens a burden casting upon an organism and reduces an interruption ratio of a blood pressure decision by a means for continuously determining blood pressure. CONSTITUTION: In a step where a pressed pressure of a cuff 10 is increased at a predetermined speed by a cuff pressure increasing means 78, when an amplitude reduction of a pressure pulse wave which is generated near the maximum blood pressure is detected by an amplitude decrease detecting means 80, a cuff pressure PCn-1 one pulse before the start point of the amplitude decrease of the pressure pulse wave that is detected by the amplitude decrease detecting means 80 is corrected by a correction value (A-B+C) which corresponds to a decreased amount of the amplitude. Consequently, a maximum blood pressure Psyse of an organism is estimated by a maximum blood pressure estimating means 82. On the basis of the maximum blood pressure Psyse and a maximum blood pressure MBPsys which is determined by a means 76 for continuously determining a blood pressure, a relation judging means 84 judges whether the corresponding relation determined by a relation determining means 74 is proper or not.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous blood pressure monitoring device for continuously monitoring a blood pressure value of a living body based on a pressure pulse wave detected by a pressure pulse wave sensor which presses an artery on the surface of a living body. Is.

[0002]

2. Description of the Related Art A blood pressure value measuring means for measuring a blood pressure value of a living body by having a cuff attached to a part of the living body and changing the compression pressure by the cuff, and the cuff of the living body are attached. A pressure pulse wave sensor that detects a pressure pulse wave generated from an artery in a region downstream of the artery by being pressed by a region downstream of the artery and a pressure pulse wave detected by the pressure pulse wave sensor. Relationship determining means for previously determining a correspondence relationship between the size and the blood pressure value measured by the blood pressure value measuring means using the cuff, and the magnitude of the pressure pulse wave detected by the pressure pulse wave sensor from the correspondence relationship. A continuous blood pressure value determining means for continuously determining the blood pressure value of the living body based on
A continuous blood pressure monitoring device of the type including a display device that displays the blood pressure value determined by the continuous blood pressure value determining means is known. For example, it is the one described in Japanese Utility Model Application Laid-Open No. 2-82309, which was previously filed and published by the applicant.

In the above-mentioned conventional continuous blood pressure monitoring device, it is inevitable that the pressure pulse wave sensor is pressed against the artery due to changes in the mounting state of the pressure pulse wave sensor due to body movement of the living body. In order to improve the accuracy of the blood pressure value determined by the value determination means, the correspondence relationship between the blood pressure value determined by the continuous blood pressure value determination means and the blood pressure value measured by the blood pressure value measurement means using the cuff is updated. The calibration for performing is performed periodically.
In this calibration, the blood pressure value is measured in the process of changing the pressure of the cuff by the blood pressure value measurement means in a predetermined procedure, and the blood pressure value obtained by the measurement and when the measurement is performed. Further, the relationship with the magnitude of the pressure pulse wave detected by the pressure pulse wave sensor is newly determined by the relationship determining means.

[0004]

By the way, when the above-mentioned calibration is executed, the pressure on the cuff imposes a burden on the living body, and a pressure is applied to a portion of the living body on the downstream side of the portion where the cuff is attached. When the pulse wave sensor is attached, there is a disadvantage that the blood pressure monitoring by the continuous blood pressure value determining means is interrupted during the calibration execution period. Such inconvenience becomes more remarkable as the calibration execution cycle is shortened in order to improve the accuracy of continuous blood pressure monitoring.

The present invention has been made in view of the above circumstances, and an object thereof is to reduce the burden on the living body and reduce the rate at which the blood pressure determination by the continuous blood pressure value determining means is interrupted. It is to provide a continuous blood pressure monitoring device.

[0006]

The object of the present invention to achieve the above object is to have a cuff to be attached to a part of the living body, and to change the compression pressure by the cuff of the living body. Blood pressure measuring means for measuring blood pressure,
A pressure pulse wave sensor for detecting a pressure pulse wave generated from an artery at a site on the downstream side of the artery by being pressed to a site on the downstream side of the artery with respect to the site where the cuff of the living body is attached, and the pressure pulse wave sensor The relationship between the magnitude of the pressure pulse wave detected by the blood pressure value measuring means and the blood pressure value measured by using the cuff, the relationship determining means for determining in advance, and the pressure pulse wave sensor from the corresponding relationship. A continuous blood pressure monitoring device of the type comprising a continuous blood pressure value determining means for continuously determining the blood pressure value of the living body based on the magnitude of the detected pressure pulse wave, (a) the compression pressure of the cuff A cuff pressure increasing means for increasing the pressure at a predetermined speed, and (b) an amplitude decrease detecting means for detecting a decrease in the amplitude of the pressure pulse wave while the cuff pressure increasing means increases the compression pressure of the cuff at a predetermined speed. When,
(c) The cuff pressure one beat before the amplitude decrease start point of the pressure pulse wave detected by the amplitude decrease detecting means is corrected by a correction value corresponding to the amplitude decrease amount to determine the systolic blood pressure value of the living body. Estimated systolic blood pressure value estimating means, (d) systolic blood pressure value estimated by the systolic blood pressure value estimating means, and based on the systolic blood pressure value determined by the continuous blood pressure value determining means, by the relationship determining means And a relationship determining means for determining the suitability of the determined correspondence relationship.

[0007]

In this way, when the amplitude decrease detecting means detects the amplitude decrease that occurs near the systolic blood pressure value in the process of increasing the cuff pressure by the cuff pressure increasing means at a predetermined speed, The hypertension value estimating means corrects the cuff pressure one beat before the amplitude decrease start point of the pressure pulse wave detected by the amplitude decrease detecting means by the correction value corresponding to the amplitude decrease amount, and thereby the maximum blood pressure of the living body. The value is estimated and determined by the relationship determining means by the relationship determining means based on the systolic blood pressure value estimated by the systolic blood pressure value estimating means and the systolic blood pressure value determined by the continuous blood pressure value determining means. The suitability of the correspondence is determined.

[0008]

As described above, when the relationship determining means determines that the correspondence relationship already determined by the relationship determining means is appropriate, the blood pressure measurement by the cuff for calibration for redetermining the relationship is performed. Since there is no need to execute the procedure, the burden on the living body due to the pressure on the cuff for calibration is eliminated, and the pressure pulse wave sensor is attached to the portion of the living body on the downstream side of the portion where the cuff is attached. In this case, the blood pressure monitoring by the continuous blood pressure value determining means is not interrupted.

Here, in another aspect of the present invention,
Preferably, the systolic blood pressure value estimating means corresponds to the storage means for storing the cuff pressure one beat before the amplitude decrease start point of the pressure pulse wave detected by the amplitude decrease detecting means, and the amplitude decrease amount. A correction value calculation unit that calculates a correction pressure value and an addition unit that calculates the systolic blood pressure value by adding the correction pressure value and the cuff pressure one beat before the amplitude decrease start point of the pressure pulse wave are included. By doing so, there is an advantage that the correction calculation becomes simple while maintaining the determination accuracy.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a diagram showing an example of the configuration of the continuous blood pressure monitoring apparatus of the present invention, which is used for monitoring the condition of a patient during or after surgery, for example. In the figure, 10
Is a cuff having a rubber bag in a cloth band-like bag, and is attached to, for example, the patient's upper arm 12 in a wound state.
A pressure sensor 14, a switching valve 16, and an air pump 18 are connected to the cuff 10 via pipes 20, respectively. The switching valve 16 has three states: a pressure supply state that allows pressure to be supplied to the cuff 10, a slow exhaust pressure state that gradually exhausts the pressure inside the cuff 10, and a rapid exhaust pressure state that rapidly exhausts the pressure inside the cuff 10. It is configured to be switched to the state.

The pressure sensor 14 detects the pressure in the cuff 10 and outputs a pressure signal SP representing the pressure to the static pressure discrimination circuit 22.
And pulse wave discrimination circuit 24, respectively. The static pressure discrimination circuit 22 includes a low-pass filter, and the pressure signal S
The cuff pressure signal SK representing the steady pressure contained in P is discriminated and the cuff pressure signal SK is supplied to the control device 28 via the A / D converter 26. The pulse wave discrimination circuit 24 includes a bandpass filter, discriminates the pulse wave signal SM ₁ which is the vibration component of the pressure signal SP, and A / Ds the pulse wave signal SM _1.
It is supplied to the control device 28 via the converter 30. The cuff pulse wave represented by the pulse wave signal SM ₁ is a pressure vibration wave generated from the brachial artery (not shown) and transmitted to the cuff 10 in synchronism with the heartbeat of the patient. It functions as a detection means.

The control device 28 includes a CPU 29 and a ROM.
31, a RAM 33, and a so-called microcomputer including an I / O port (not shown),
The CPU 29 outputs a drive signal from the I / O port by performing a signal process while utilizing the storage function of the RAM 33 according to a program stored in advance in the ROM 31, and outputs the drive signal from the I / O port to the switching valve 16 and the air through a drive circuit (not shown). Control the pump 18. When measuring the blood pressure using the cuff 10 for calibration, for example, the cuff 10
3mm after rapidly increasing the internal pressure to the specified target pressure
The blood pressure such as the systolic blood pressure value and the diastolic blood pressure value is measured by the oscillometric method on the basis of the change in the pulse wave represented by the pulse wave signal SM ₁ that is sequentially sampled in the step of gradually decreasing the blood pressure at a speed of about Hg / sec. The value is determined, and the determined blood pressure value is displayed on the display 32.

The pressure pulse wave detection probe 34 is detachably attached to a wrist 42 by a wearing band 40 in a state where an open end of a housing 36 having a container shape faces a body surface 38 of a human body. A pressure pulse wave sensor 46 is provided inside the housing 36 so as to be relatively movable via a diaphragm 44 and projectable from an open end of the housing 36. The housing 36, the diaphragm 44 and the like form a pressure chamber 48. Has been done. Pressure air is supplied from the air pump 50 into the pressure chamber 48 via the pressure regulating valve 52, whereby the pressure pulse wave sensor 46 presses the pressure P corresponding to the pressure in the pressure chamber 48. It is pressed against the body surface 38 with _HD .

The pressure pulse wave sensor 46 is constructed by arranging a large number of semiconductor pressure sensitive elements (not shown) on the pressing surface 54 of a semiconductor chip made of, for example, single crystal silicon, and the body of the wrist 42. Pressing onto the radial artery 56 of the surface 38 causes it to develop from the radial artery 56
The pressure oscillating wave, that is, the pressure pulsating wave, transmitted to the controller 28 is detected, and the pressure pulsating wave signal SM ₂ representing the pressure pulsating wave is supplied to the controller 28 via the A / D converter 58. The upper part of FIG. 2 shows an example of the pressure pulse wave detected by the pressure pulse wave sensor 46.

The CPU 29 of the control device 28 has a ROM 31
The signal processing is executed while utilizing the storage function of the RAM 33 according to the program stored in advance, and a drive signal is output to the air pump 50 and the pressure regulating valve 52 via a drive circuit (not shown) to adjust the pressure in the pressure chamber 48. To do. In continuous blood pressure monitoring, the optimum pressing force P _HDO of the pressure pulse wave sensor 46 is determined based on the pressure pulse wave successively obtained in the process of gradually changing the pressure in the pressure chamber 48, and the pressure regulating valve 52 is set to the pressure pulse wave sensor 46. The optimum pressing force P _HDO is controlled so as to be maintained, and the maximum blood pressure value BP _SYS and the minimum blood pressure value BP _{DI A} measured using the cuff 10 and the optimum pressing force P _HDO are maintained. Correspondence between the blood pressure value BP and the magnitude P _M (absolute value) of the pressure pulse wave measured based on the maximum value P _Mmax and the minimum value P _{Mmin of} the pressure pulse wave detected by the pulse wave sensor 46. The relationship is obtained, and the magnitude P _M (mmHg) of the pressure pulse wave sequentially detected by the pressure pulse wave sensor 46, that is, the maximum value (upper peak value) P _Mmax and the minimum value (lower peak value) P _Mmin are obtained from this relationship. systolic blood pressure value MBP _SYS and the diastolic blood pressure value MBP _DIA (audit on the basis of Blood pressure value) sequentially determining the numerical display the systolic blood pressure MBP _SYS and the diastolic blood pressure value MBP _DIA that the determined at indicator 32 for each beat, to continuously display the waveform representing the monitored blood pressure values MBP.

The above correspondence relationship is shown in FIG. 3, for example, and is expressed by Equation 1. In this formula 1,
A is a constant indicating a slope, and B is a constant indicating an intercept.

[0018]

[Equation 1] MBP = A · P _M + B

FIG. 4 is a functional block diagram for explaining a main part of the control function of the control device 28 in the continuous blood pressure monitoring device configured as described above. In the figure, the compression pressure of the cuff 10 is detected by the pressure sensor 14. The blood pressure value measuring means 72 measures the compression pressure of the cuff 10 by 2 to 3 mmHg / s.
The blood pressure value of the living body is measured according to the oscillometric method or the Korotkoff sound method based on the change of the pulse synchronization signal, for example, the pulse wave amplitude or the Korotkoff sound obtained in the process of gradually changing at a speed of about ec. The pressure pulse wave sensor 46 detects the pressure pulse wave generated from the radial artery at the site on the downstream side of the artery by being pressed by the site on the downstream side of the artery with respect to the site where the cuff 10 of the living body is attached. The relationship determining means 74
The correspondence between the magnitude of the pressure pulse wave detected by the pressure pulse wave sensor 46 and the blood pressure value measured by the blood pressure value measuring means 72 is determined in advance. The continuous blood pressure value determining means 76 continuously determines the monitored blood pressure value of the living body based on the magnitude of the pressure pulse wave detected by the pressure pulse wave sensor 46 from the correspondence relationship.

On the other hand, the cuff pressure increasing means 78 continuously or stepwise increases the compression pressure of the cuff 10 at a predetermined speed to a preset target pressure higher than the systolic blood pressure value of the living body. The amplitude decrease detecting means 80 is the cuff pressure increasing means 7
The decrease in the amplitude of the pressure pulse wave is detected during the process in which the compression pressure of the cuff 10 is increased by 8 at a predetermined speed. The systolic blood pressure value estimation means 82 has a cuff pressure P _Cn-1 one beat before the start point of the amplitude reduction of the pressure pulse wave detected by the amplitude reduction detection means 80.
_Is corrected by a correction value corresponding to the amount of decrease in the amplitude to estimate the systolic blood pressure value P _SYSE of the living body. The relationship determining means 84, based on the systolic blood pressure value P _SYSE estimated by the systolic blood pressure value estimating means 82 and the _systolic blood pressure value MBP _SYS determined by the continuous blood pressure value determining means 76, the relationship determining means 74. The suitability of the correspondence relationship determined by is determined.

The systolic blood pressure value estimating means 82 stores the cuff pressure P _Cn-1 one beat before the amplitude decrease start point of the pressure pulse wave detected by the amplitude decrease detecting means 80.
And a correction value calculating means 88 for calculating the correction pressure values A, B and C corresponding to the amplitude reduction amount, and the cuff pressure P _Cn-1 and the correction pressure one beat before the amplitude reduction start point of the pressure pulse wave. Values A, B, C
And adding means 90 for calculating the systolic blood pressure value P _SYSE by adding and.

FIG. 5 is a flow chart for explaining a main part of the control operation of the control device 28, which is executed every preset calibration cycle. In step S1 (the step is omitted hereinafter) in the drawing, the pressure chamber 48 is gradually increased in pressure, and the pressure pulse wave sequentially detected by the pressure pulse wave sensor 46 in the process of gradually increasing the pressure in the pressure chamber 48. The pressure in the pressure chamber 48 at which the amplitude of the pressure is maximum, that is, the optimum pressing force P _HDO of the pressure pulse wave sensor 46 is determined, and
By keeping the pressure in the pressure chamber 48 at the optimum pressing force P _HDO , the pressing force of the pressure pulse wave sensor 46 is held at an optimum constant value. In the present embodiment, the air pump 50, the pressure regulating valve 52, and step S1 (more accurately, the portion of CPU 29, ROM 31, and RAM 33 used for executing step S1) correspond to the pressing force adjusting means. To do.

In subsequent S2, it is determined whether or not the correspondence shown in FIG. 3 has already been determined for the living body to which the cuff 10 is attached. When the determination in S2 is affirmative, the correspondence relation suitability determination routine for determining the suitability of the correspondence relation is executed in S3 to S6, but initially, the determination in S2 is denied, so the blood pressure measurement by the cuff 10 is performed. S6 and the subsequent steps are executed.

First, in S6 corresponding to the blood pressure value measuring means 72, the switching valve 16 is switched to the pressure supply state and the air pump 18 is operated to make the pressure in the cuff 10 higher than the expected maximum blood pressure value of the patient. High target pressure (eg 18
After raising the pressure to 0 mmHg), the air pump 18 is stopped and the switching valve 16 is switched to the gradual discharge pressure state to decrease the pressure in the cuff 10 at a predetermined gradual pressure reduction rate of about 2 to 3 mmHg / sec. As a result, the systolic blood pressure value BP _SYS and the average blood pressure are calculated according to the well-known oscillometric blood pressure value determination algorithm on the basis of the change in the amplitude of the pulse wave represented by the pulse wave signal SM _{1 that} is sequentially obtained in the slow pressure reduction process. Value B
P _MEAN and the minimum blood pressure value BP _DIA are measured, and the pulse rate and the like are determined based on the pulse wave interval. Then, the measured blood pressure value and pulse rate are displayed on the display 3
2 is displayed, and the switching valve 16 is switched to the rapid exhaust pressure state, so that the pressure inside the cuff 10 is rapidly exhausted.

Next, S corresponding to the relationship determining means 74.
In 7, the correspondence relationship between the magnitude of the pressure pulse wave from the pressure pulse wave sensor 46 (absolute value of the pressure pulse wave signal SM ₂ ) and the blood pressure values BP _SYS , BP _DIA by the cuff 10 measured in S6 above. Is required. That is, one pulse of the pressure pulse wave from the pressure pulse wave sensor 46 is read and the maximum value P _{Mm ax} of the pressure pulse wave is read.
And the minimum value P _Mmin is determined, and the cuff 1 is obtained at the maximum value P _Mmax and the minimum value P _{Mmin of the} pressure pulse wave and S6.
Based on the systolic blood pressure value BP _SYS and the diastolic blood pressure value BP _DIA measured by 0, the correspondence between the magnitude of the pressure pulse wave and the blood pressure value shown in FIG. 3 is determined.

When the correspondence is determined as described above, the continuous blood pressure monitoring routine is executed in S8 and subsequent steps. First, in S8, it is determined whether or not one pulse wave is input. If the determination in S8 is denied, 1
Although it is made to wait until one pulse wave is input, if the determination in S8 is affirmative, the continuous blood pressure value determining means 76
In S9 corresponding to, the maximum value P _Mmax and the minimum value P _{Mmin of the} wave are determined from the pressure pulse wave signal SM ₂ from the pressure pulse wave sensor 46 pressed by the optimum pressing force P _HDO , and in S7. The systolic blood pressure value MBP _SYS and the diastolic blood pressure value MBP _DIA (monitored blood pressure value) are determined based on the highest value P _Mmax and the lowest value P _Mmin of the pressure pulse wave from the correspondence relationship obtained in FIG. The determined monitor blood pressure value is displayed on the display 32 together with the continuous waveform of the pressure pulse wave.

Next, in S10, it is judged whether or not the elapsed time since the blood pressure measurement by the cuff 10 in the above step S6 has passed a preset cycle of about 5 to 20 minutes. If the determination in S10 is negative, the continuous blood pressure monitoring routine from S8 onward is repeatedly executed, and the systolic blood pressure value MBP _SYS and the diastolic blood pressure value MBP _DIA are continuously determined and displayed for each beat. . However, if the determination in S10 is affirmative, the above S2 and subsequent steps are executed again.

The correspondence is once determined as described above.
In the control cycle after
Then, by S3 corresponding to the cuff pressure increasing means 78,
10 is atmospheric pressure at a predetermined speed of 20 to 30 mmHg / sec
The pressure is increased relatively quickly. Then such a cuff
Estimated systolic blood pressure value P in 10 rapid pressurization processes_SYSECalculate
S4 which is a routine for issuing is executed. This S
In 4, the pressure pulse wave signal SM ₂ The amplitude of the pressure pulse wave represented by
Is detected and the amplitude of the pressure pulse wave is decreased.
Time point 1 beat before the start point₁Cuff pressure P at_Cn-1 But that
Be corrected by the correction value corresponding to the amplitude reduction amount of
Estimated systolic blood pressure P_SYSEIs determined.

That is, in FIG. 6 showing the above S4 in detail, at SB1, it is determined whether the amplitude of the pulse wave signal SM ₁ or the pressure pulse wave signal SM ₂ depends on whether the body is in motion or the cuff 10 is being stepped down. The determination is made based on that the amplitude shows an abnormal value or the cuff pressure signal SK shows a negative changing direction. If the determination at SB1 is affirmative, the pressure pulse wave is kept on standby until it reaches a stable state, but if not, at SB2 corresponding to the amplitude reduction detecting means 80, the amplitude of the pressure pulse wave, that is, the pulse is detected. It is determined whether the pressure ΔP _M is less than or equal to a preset determination reference value ΔP _M1 . The determination reference value ΔP _M1 is used to detect a decrease in the amplitude of the pressure pulse wave generated in the radial artery downstream of the brachial artery due to compression of the brachial artery by the cuff 10. It is set to a value of about 75% of the average pulse pressure ΔP _MAV which is the average value.

If the determination at SB2 is negative, SB
1 and below are repeatedly executed, but the compression pressure of the cuff 10 is generated.
SB2's judgment is affirmative by approaching the maximum blood pressure of the body
Once determined, the correction value is determined according to the decrease amount of the pulse wave amplitude.
SB3 and subsequent steps for execution are executed. First, smell in SB3
The current cuff pressure P_CnAnd the cuff pressure P one beat before_Cn-1By the difference
A correction value A (= P_Cn−P_Cn-1) Is calculated, then SB
4, pulse pressure ΔP _MIs zero, in other words
It is determined whether the pulse wave appears. Due to the pressure on the cuff 10.
Decrease in pulse wave amplitude caused by obstruction of blood flow
The pulse wave amplitude of the current pressure pulse wave does not appear when is detected
The state is t when the last pulse wave occurred.₁From living body pulse
Time t when the cycle has sufficiently passed₂For example, if the pulse cycle is 1.
Detection based on the presence or absence of pulse wave amplitude at the time when 5 times has passed
Is done.

If the pulse wave amplitude is not zero in the current cycle in which the decrease in the pulse wave amplitude is detected by SB2, the determination at SB4 is denied, so that the pulse pressure Δ at SB5.
It is determined whether P _M is less than or equal to a preset determination reference value ΔP _M2 . The determination reference value ΔP _M2 is used to determine the magnitude of the current pressure pulse wave, and is set to, for example, about 45% of the average pulse pressure ΔP _MAV which is the moving average value of the pulse pressure. . If the pulse wave amplitude of the current pressure pulse wave in which the decrease of the pulse wave amplitude is detected by SB2 is relatively large, the determination at SB5 is denied, and therefore the correction value C is set to "10" at SB7 and SB8. After the correction value B is set to "0" in S,
At B9, the estimated systolic blood pressure value P _SYSE is calculated from Expression 2. In this case, P _SYSE = P _Cn-1 + A + 10. In Expression 2, P _{Cn -1} is the cuff pressure when the pulse wave is generated one beat before, and is stored in advance in the storage means 86 corresponding to the predetermined area of the ROM. The correction value B is determined in relation to the magnitude of the pulse wave amplitude in the previous cycle, and the correction value C is determined in relation to the magnitude of the pulse wave amplitude in the current cycle.

[0032]

[ _Equation 2] P _SYSE = P _Cn-1 + A-B + C

However, if the pulse wave amplitude of the pressure pulse wave at this time when the decrease of the pulse wave amplitude is detected by SB2 is relatively small, the determination at SB5 is affirmative, and therefore the correction value C is "-10" at SB6. , And the correction value B is set to “0” in SB8, the estimated systolic blood pressure value P _SYSE is calculated from Equation 2 in SB9. In this case,
P _SYSE = P _Cn-1 + A-10. From the above, the correction value C set in SB6 and SB7 is set to a larger value as the current pulse wave amplitude increases.

If the pulse wave amplitude is zero in this cycle when the decrease in the pulse wave amplitude is detected by SB2, the determination at SB4 is affirmative, so the correction value C is set to "0" at SB10. Then, in SB11, the pulse pressure ΔP _Mn-1 of the pulse wave one beat before is determined by a preset reference value Δ.
It is determined whether P _M3 or more. This judgment reference value Δ
P _M3 is a value for determining whether or not the pressure pulse wave one beat before has collapsed. For example, the value is about 88% of the average pulse pressure ΔP _MAV , which is the moving average value of the pulse pressure. Is set.

When the pressure pulse wave one beat before is not crushed, the determination at SB11 is affirmative, and therefore SB8 is set.
After the correction value B is set to “0” in, the estimated systolic blood pressure value P _SYSE is calculated from Equation 2 in SB9. In this case, P _SYSE = P _Cn-1 + A.

However, if collapse occurs in the pressure pulse wave one beat before, the determination at SB11 above is denied, so SB
12, the pulse pressure ΔP _Mn-1 of the pulse wave one beat before is equal to or greater than the preset determination reference value ΔP _M4 and the determination reference value ΔP
It is determined whether _M5 or more. This judgment reference value ΔP
_M4 and ΔP _M5 are values for determining the magnitude of the pressure pulse wave one beat before the collapse, and are, for example, about 80% of the average pulse pressure ΔP _MAV which is the moving average value of the pulse pressure. Value and a value of about 5 mmHg.

When the pressure pulse wave one beat before the crushing is relatively large, the determination at SB12 is affirmative, and therefore, after the correction value B is set to "A / 2" at SB13, In SB9, the estimated systolic blood pressure value P _SYSE is calculated from Expression 2. In this case, P _SYSE = P _Cn-1 + A-A
/ 2.

The pressure pulse wave one beat before the collapse is compared
If it is relatively small, the determination in SB12 above is denied.
Then, in SB14, the pulse pressure ΔP of the pressure pulse wave one beat before_Mn-1But
Predetermined judgment reference value ΔP_M6Whether or not it is above
Refused. This judgment reference value ΔP _M6Is crushed
Is a value for determining the magnitude of the pressure pulse wave one beat before,
For example, the value is set to about 5 mmHg.

If the pressure pulse wave one beat before the occurrence of crushing is relatively small, but is larger than the value of about 5 mmHg, the determination at SB14 is affirmative, and therefore the correction value B at SB15 is "A / 2 + A". SB9 after being set to "/ 4"
At, the estimated systolic blood pressure value P _{SY SE} is calculated from Equation 2. In this case, P _SYSE = P _Cn-1 + A−A / 2−A /
It becomes 4. However, if the pressure pulse wave one beat before the collapse occurs is smaller than the value of about 5 mmHg, the determination at SB14 is negative, so after the correction value B is set to "A" at SB16, In SB9, the estimated systolic blood pressure value P _SYSE is calculated from Expression 2. In this case, P _SYSE
= P _Cn-1 . That is, the correction value B is determined to be larger as the pressure pulse wave one beat before becomes smaller. In this embodiment, SB3 to SB8 and SB10 to SB16 correspond to the correction value calculating means 88.

When the estimated systolic blood pressure value P _SYSE is calculated as described above, the latest systolic blood pressure value MBP _SYS calculated in S 9 and the above _SB 9 in S 5 of FIG. 5 corresponding to the relationship determining means 84. It is determined whether or not the difference | MBP _SYS −P _SYSE | with the estimated systolic blood pressure value P _SYSE calculated in _step 1 is less than or equal to a preset determination reference value ΔP _H. This judgment reference value ΔP _H is the monitored blood pressure value calculated based on the correspondence relationship in FIG. 3, that is, the systolic blood pressure value MBP.
It is a value for determining whether or not the difference between _SYS and the estimated systolic blood pressure value P _SYSE has become large enough to impair the reliability of monitoring, and is set to, for example, about 20 mmHg.

If the determination in S5 is affirmative, as shown in FIG.
Since the correspondence relationship of 1 is available with sufficient monitoring accuracy, after the pressure of the cuff 10 is released in S11, S8 and the following steps are executed to monitor blood pressure. 2 t
_{The three} time points show this state. However, if the determination in S5 is negative, the correspondence relationship in FIG. 3 is in a state of being out of alignment with the actual situation. Therefore, after the correspondence relationship is updated in S6 and S7, S8 and subsequent steps are executed to monitor blood pressure. Done.

As described above, according to the present embodiment, the pressure pulse generated near the systolic blood pressure value in the process of increasing the compression pressure of the cuff 10 at a predetermined speed by S3 corresponding to the cuff pressure increasing means 78. When the amplitude decrease of the wave is detected by SB2 corresponding to the amplitude decrease detecting means 80, the amplitude decrease of the pressure pulse wave detected by the amplitude decrease detecting means 80 is performed by SB3 to SB16 corresponding to the systolic blood pressure value estimating means 82. The systolic blood pressure value P _SYSE of the living body is estimated by correcting the cuff pressure P _Cn-1 one beat before the starting point by the correction value ( _AB + C) corresponding to the amplitude decrease amount, and the relationship determining means 84
Then, based on the systolic blood pressure value P _SYSE estimated by the systolic blood pressure value estimating means 82 and the _systolic blood pressure value MBP _SYS determined by the continuous blood pressure value determining means 76, by S7 corresponding to the relationship determining means 74. The suitability of the determined correspondence relationship is determined. In this way, the correspondence relationship already determined by the relationship determining means 74 is the relationship determining means 84.
By if it is determined to be appropriate, since the execution of the blood pressure measurement using the cuff for calibration to re-determine the relationship is not required, as shown in two-dot chain line t ₃ after the time of FIG. 2 calibration The pressure on the cuff for the cushion eliminates the strain on the living body, and
Even when the pressure pulse wave sensor is attached to a part on the downstream side of the part of the living body to which the cuff is attached, the continuous blood pressure value determining means 76.
Blood pressure monitoring is not interrupted.

Further, according to this embodiment, the systolic blood pressure value estimating means 82 has the cuff pressure P _Cn-1 one beat before the amplitude decrease start point of the pressure pulse wave detected by the amplitude decrease detecting means 80.
Storing means 86, a correction value calculating means 88 for calculating a correction pressure value corresponding to the amplitude reduction amount of the pressure pulse wave, and a cuff pressure P _Cn− one beat before the start point of the amplitude reduction of the pressure pulse wave. Since it is composed of the adding means 90 for calculating the systolic blood pressure value by adding ₁ and the correction pressure value (A−B + C), there is an advantage that the correction calculation is simple while maintaining the determination accuracy.

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, the above-mentioned blood pressure value measuring means 72 is
According to the so-called oscillometric method, the blood pressure value is determined based on the change state of the magnitude of the pressure pulse wave that changes with the compression pressure of the cuff 10, but according to the so-called Korotkoff sound method, It may be configured to determine the blood pressure value based on the Korotkoff sound that occurs and disappears with the pressing pressure.

[0046] Further, the relationship determining means 84 described above, although the latest systolic blood pressure value MBP _SYS determined in a continuous blood pressure determining means 76 has been used, the highest blood pressure value determined by the latest few beats MBP _SYS The moving average value or the like may be used. By doing so, it is possible to mitigate the influence of abnormal values due to body movements and the like.

Further, in the continuous blood pressure monitoring apparatus of the above embodiment, the routine of FIG. 5 is executed at every predetermined calibration setting cycle, but the blood pressure value MBP determined by the continuous blood pressure value determining means 76 becomes abnormal. A determination step is provided to determine whether the blood pressure value MBP has changed, and if it is determined in this determination step that the blood pressure value MBP has changed abnormally, S
You may comprise so that 7 or less may be performed.

Further, in the above-described embodiment, the cuff 10 is attached to the upper arm and the pressure pulse wave sensor 46 is attached to the wrist for detecting the pressure pulse wave of the radial artery, but the cuff 10 is attached to the thigh. A pressure pulse wave sensor 46 may be attached to the foot in order to detect the pressure pulse wave of the dorsal foot artery.

In addition, 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 showing a configuration of a continuous blood pressure monitoring device that is an embodiment of the present invention.

FIG. 2 is a diagram illustrating a pressure pulse wave detected by a pressure pulse wave sensor of the embodiment of FIG. 1 in association with a pressure change of a cuff.

FIG. 3 is a diagram illustrating a correspondence relationship used in the embodiment of FIG.

FIG. 4 is a functional block diagram illustrating a control function of the control device according to the embodiment of FIG.

5 is a flow chart illustrating a control operation of the control device of the embodiment of FIG.

6 is a flowchart illustrating an estimated systolic blood pressure value determination routine of FIG.

[Description of sign]

 10: Cuff 46: Pressure pulse wave sensor 72: Blood pressure value measuring means 74: Relationship determining means 76: Continuous blood pressure value determining means 78: Cuff pressure increasing means 80: Amplitude decrease detecting means 82: Maximum blood pressure value estimating means 84: Relationship determination Means 86: Storage Means 88: Correction Value Calculation Means 90: Addition Means

Claims (2)

[Claims] 1. A blood pressure value measuring means having a cuff attached to a part of a living body, for measuring a blood pressure value of the living body by changing a compression pressure by the cuff, and the cuff of the living body is attached. A pressure pulse wave sensor for detecting a pressure pulse wave generated from an artery in a region downstream of the artery by being pressed by a region downstream of the artery, and a pressure pulse wave detected by the pressure pulse wave sensor. Relationship determining means for previously determining a correspondence relationship between the magnitude and the blood pressure value measured by the blood pressure value measuring means using the cuff, and the magnitude of the pressure pulse wave detected by the pressure pulse wave sensor from the correspondence relationship. A continuous blood pressure monitoring device of the type comprising a continuous blood pressure value determining means for continuously determining a blood pressure value based on the level of the pressure, and a cuff pressure increasing means for increasing the compression pressure of the cuff at a predetermined speed, The cuff pressure is increased by the cuff pressure increasing means. Amplitude decrease detecting means for detecting the decrease in the amplitude of the pressure pulse wave in the process of increasing the pressure pulse at a predetermined speed, and the cuff pressure one beat before the amplitude decrease start point of the pressure pulse wave detected by the amplitude decrease detecting means. And a systolic blood pressure value estimating means for estimating a systolic blood pressure value of the living body by correcting the systolic blood pressure value by a correction value corresponding to the amplitude decrease amount, and a systolic blood pressure value estimated by the systolic blood pressure value estimating means,
A continuous blood pressure monitoring device comprising: a relationship determination unit that determines whether the correspondence relationship determined by the relationship determination unit is appropriate based on the maximum blood pressure value determined by the continuous blood pressure value determination unit. 2. The systolic blood pressure value estimating means corresponds to the storage means for storing the cuff pressure one beat before the amplitude decrease start point of the pressure pulse wave detected by the amplitude decrease detecting means, and the amplitude decrease amount. Correction value calculating means for calculating the corrected pressure value, and addition means for calculating the systolic blood pressure value by adding the cuff pressure one beat before the amplitude reduction start point of the pressure pulse wave and the corrected pressure value. The continuous blood pressure monitoring device according to claim 1, which is a non-use device.