JP2000245702A - Ressure pulse wave detecting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressure pulse wave detecting device capable of successively providing a precise waveform of pressure pulse wave. SOLUTION: A ratio of the difference ΔMBP between the monitored maximum blood pressure value MBPSYS and monitored minimum blood pressure value MGPDIA successively determined by a monitored blood pressure value determining means 84 to the difference ΔEBP between two estimated blood pressure values EBPSYS and EBPDIA successively determined by an amplitude blood pressure ratio determining means or distortion value calculating means 86 is determined as amplitude blood pressure ratio R or distortion value D. Since the pressure pulse waveform of the pressure pulse wave detected by a pressure pulse wave sensor 46 can be successively corrected by multiplying the amplitude of this pressure pulse wave detected by the distortion value D calculated by the distortion value calculating means 86 by a pressure pulse wave amplitude correcting means 88, a precise waveform of pressure pulse wave can be successively provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure pulse wave detecting device capable of sequentially obtaining accurate pressure pulse wave waveforms.

[0002]

2. Description of the Related Art There is known a pressure pulse wave detecting device which sequentially detects a pressure pulse wave generated from an artery using a pressure pulse wave sensor pressed toward an artery of a living body. For example,
An apparatus described in Japanese Patent Application Laid-Open No. 8-187230 or the like is such an apparatus. According to this pressure pulse wave detection device, a pressure pulse wave is detected while the pressure pulse wave sensor is pressing the artery with an optimal pressing force set in advance so that a part of the blood vessel wall of the artery is substantially flat. Therefore, a relatively accurate pressure pulse wave can be obtained. Further, since the intensity of the pressure pulse wave changes in response to the change in the blood pressure value of the living body, the apparatus described in the above publication uses the pressure pulse wave to calculate the minimum blood pressure value, the maximum blood pressure value,
Changes in average blood pressure are monitored continuously.

Further, the waveform of the pressure pulse wave detected by the pressure pulse wave detecting device has a sudden change in blood pressure, so that it is necessary to continuously monitor the change in blood pressure. It is used in various circulatory function tests such as a stress test and a Valsalva test. Further, an apparatus for calculating a pressure waveform in the aorta by a transfer function from a waveform of the pressure pulse wave detected by the pressure pulse wave detection device has also been proposed. For example, the apparatus described in Japanese Patent Application Laid-Open No. H10-94526 is such an apparatus. Further, since the area of the pressure pulse wave detected by the pressure pulse wave detecting device corresponds to the amount of blood ejected from the heart, the blood ejection function of the heart can be evaluated.

[0004]

When evaluating the circulatory system of a living body using the waveform of the pressure pulse wave, it is necessary that the waveform of the pressure pulse wave is accurate. In order to accurately detect the pressure pulse wave waveform, it is necessary that the pressure pulse wave sensor presses the blood vessel with a pressing force that makes a part of the blood vessel wall of the artery substantially flat. However, in the conventional pressure pulse wave detecting device, when the optimum pressing force is determined, the optimum pressing force is maintained. However, the pressing force is maintained due to the familiarity between the pressure pulse wave sensor and the skin. In some cases, the pressure was no longer appropriate. Therefore, even if the pressing force of the pressure pulse wave sensor is maintained at the optimum pressing force, the waveform of the detected pressure pulse wave may not be accurate. Further, the determination of the optimal pressing force is as follows:
Since it was necessary to continuously change the pressing force over a preset range sufficiently including the optimum pressing force, the optimum pressing force could not be frequently determined again.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a pressure pulse wave detecting device capable of sequentially obtaining accurate pressure pulse wave waveforms. .

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the present invention is to use a pressure pulse wave sensor pressed toward an artery of a living body to generate a pressure pulse wave generated from the artery. A pressure pulse wave detection device for sequentially detecting,
(a) an estimated blood pressure value determining means for sequentially determining an estimated blood pressure value of the living body based on pulse wave propagation velocity information related to a pulse wave propagation velocity in the artery of the living body, and (b) the estimated blood pressure value determining means. Pressure pulse wave correcting means for sequentially correcting the shape of the pressure pulse wave detected by the pulse wave sensor based on the determined estimated blood pressure value.

[0007]

In this manner, the pressure pulse wave correcting means sequentially corrects the shape of the pressure pulse wave detected by the pressure pulse wave sensor based on the estimated blood pressure value determined by the estimated blood pressure value determining means. Therefore, it is possible to sequentially obtain an accurate pressure pulse waveform.

[0008]

In another preferred embodiment of the present invention, preferably, the pressure pulse wave detecting device comprises: (c) the pressure pulse wave sensor is pressed so that a part of a blood vessel wall of the artery is substantially flat. The apparatus further includes an optimal pressing force determining means for determining an optimal pressing force, wherein the estimated blood pressure value determining means (a) includes at least two of an estimated systolic blood pressure value, an estimated average blood pressure value, and an estimated diastolic blood pressure value of the living body.
The pressure pulse wave correcting means (b)
(B-1) at the time when the optimum pressing force is determined by the optimum pressing force determining means, is detected by the pressure pulse wave sensor and the difference between the two estimated blood pressure values determined by the estimated blood pressure value determining means. A reference amplitude blood pressure ratio determining means for determining a reference amplitude blood pressure ratio with respect to an estimated blood pressure of the amplitude of the pressure pulse wave based on the amplitude difference between the predetermined two portions of the pressure pulse wave; (b-2)
Based on the difference between the two estimated blood pressure values sequentially determined by the estimated blood pressure value determining means and the amplitude difference between the two portions of the pressure pulse wave sequentially detected by the pressure pulse wave sensor, Amplitude blood pressure ratio determining means for sequentially determining an amplitude blood pressure ratio with respect to the estimated blood pressure of the amplitude, and (b-3) a pressure pulse waveform sequentially detected by the pressure pulse wave sensor based on the reference amplitude blood pressure ratio and the amplitude blood pressure ratio. And (b-4) a pressure pulse wave detected by the pressure pulse wave sensor based on the distortion value of the pressure pulse waveform sequentially calculated by the distortion value calculation means. Pressure pulse wave amplitude correcting means for sequentially correcting the amplitude of the pressure pulse wave. With this configuration, the difference between the two estimated blood pressure values and the amplitude difference between two predetermined portions of the pressure pulse wave at the time when the optimum pressing force is determined by the optimum pressing force determining device is determined by the reference amplitude blood pressure ratio determining device. , A reference amplitude blood pressure ratio with respect to the estimated blood pressure of the pressure pulse wave is determined, and the two estimated blood pressure values sequentially determined by the amplitude blood pressure ratio determining means and the two portions of the pressure pulse wave sequentially detected are determined by the amplitude blood pressure ratio determining means. The amplitude blood pressure ratio is sequentially determined on the basis of the amplitude difference between the pressure pulse waves, and the distortion value calculating means detects the distortion value of the pressure pulse wave sequentially detected by the pressure pulse wave sensor based on the reference amplitude blood pressure ratio and the amplitude blood pressure ratio. Is calculated. Then, the amplitude of the pressure pulse wave detected by the pressure pulse wave sensor is sequentially corrected based on the strain value calculated by the strain value calculating means by the pressure pulse wave amplitude correcting means. Waveforms can be obtained sequentially. (In this specification, the amplitude means a magnitude (intensity) of the pulse wave for one beat from the minimum value, that is, a fluctuation component of the pulse wave.)

[0009] Preferably, the pressure pulse wave detecting device comprises:
The apparatus further includes a display for graphically displaying the pressure pulse waveform, and waveform display means for sequentially displaying the pressure pulse waveform corrected by the pressure pulse wave correction means on the display as a graph. With this configuration, the accurate pressure pulse waveform corrected by the pressure pulse wave correction means is sequentially displayed on the display as a graph, so that the fluctuation of the blood pressure of the living body can be accurately monitored.

Preferably, the pressure pulse wave detecting device is
A correction monitoring blood pressure value determining means for continuously determining a correction monitoring blood pressure value of the living body based on the magnitude of the pressure pulse wave whose amplitude has been corrected by the pressure pulse wave amplitude correcting means from a preset relationship. In addition. If you do this,
Since the corrected monitoring blood pressure value determining means continuously determines the corrected monitoring blood pressure value based on the magnitude of the pressure pulse wave whose amplitude has been corrected, there is an advantage that an accurate blood pressure value can be continuously obtained.

[0011] Preferably, the pressure pulse wave detecting device comprises:
The correspondence between the pressure pulse wave used in the corrected monitoring blood pressure value determining means and the corrected monitoring blood pressure value is determined by the magnitude of the pressure pulse wave detected by the pressure pulse wave sensor and the estimated blood pressure value determining means. The apparatus further includes a correspondence determination unit that determines in advance based on at least two estimated blood pressure values. With this configuration, the preset relationship in the corrected monitoring blood pressure value determining means is determined based on the sequentially determined estimated blood pressure value. That is, since it is not necessary to measure the blood pressure value of the living body using a cuff that changes the compression pressure on a part of the living body in order to determine the above-described correspondence, there is an advantage that the correspondence can be determined quickly. is there.

[0012]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a diagram showing an example of the configuration of a pressure pulse wave detecting apparatus according to the present invention. For example, the apparatus is used to monitor the condition of a patient during or after an operation or a living body during an exercise load test. Used. In the drawing, reference numeral 10 denotes a cuff having a rubber bag in a cloth band-shaped bag, which is mounted, for example, in a state of being wound around the upper arm 12 of a patient. The cuff 10 has a pressure sensor 14, an exhaust control valve 16, and an air pump 18 connected to the pipe 2
0 are respectively connected. Exhaust control 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 22.
And the pulse wave discrimination circuit 24. The static pressure discriminating circuit 22 includes a low-pass filter, and the pressure signal S
A cuff pressure signal SK representing a steady pressure included in P is discriminated, and the cuff pressure signal SK is supplied to the arithmetic and control unit 28 via the A / D converter 26. The pulse wave discrimination circuit 24 includes a band-pass filter, discriminates the pulse wave signal SM ₁ which is a vibration component of the pressure signal SP, and converts the pulse wave signal SM ₁ to A
It is supplied to the arithmetic and control unit 28 via the / D converter 30.
Cuff pulse wave which the pulse wave signal SM ₁ represents is generated from the brachial artery (not shown) in synchronization with the patient's heart is the pressure vibration wave transmitted to the cuff 10, the pulse-wave filter circuit 24 cuff-pulse-wave It functions as detection means.

The arithmetic and 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 the storage function of the RAM 33 according to a program stored in the ROM 31 in advance. As a result, a drive signal is output from the I / O port to control the exhaust control valve 16 and the air pump 18 via a drive circuit (not shown). When measuring the blood pressure using the cuff 10, for example, the pressure in the cuff 10 is rapidly increased to a predetermined target pressure, and then gradually reduced at a speed of about 3 mmHg / sec. The systolic blood pressure value BP _SYS and the diastolic blood pressure value BP by the oscillometric method based on the change of the pulse wave represented by the wave signal SM ₁
The blood pressure value BP (reference blood pressure value) such as _DIA is determined, and the determined blood pressure value BP is displayed on the display 32.

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 35 attached to predetermined portions of a living body. An electrocardiogram lead signal SM ₂ indicating an electrocardiogram wave is supplied to the arithmetic and control unit 28. In addition, since the electrocardiogram guiding device 34 is for detecting the Q wave or the R wave of the electrocardiographic guiding waves corresponding to the time when the blood in the heart starts to be pumped toward the aorta, It functions as a first pulse wave detection device.

As shown in detail in FIG. 2, the pressure pulse wave detecting probe 36 has a case 38 for accommodating a sensor housing 37 in the form of a container, and a probe 38 for moving the sensor housing 37 in the width direction of the radial artery 56. And a screw shaft 40 screwed to the sensor housing 37 and rotationally driven by a motor (not shown) provided in a driving section 39 of the case 38. The case 38 has a mounting band 4
1 is attached and can be attached to and detached from the side on which the cuff 10 is not wound by the wearing band 41, for example, the left wrist 43, with the opening end of the sensor housing 37 having a container shape facing the body surface 42 of the human body. It can be attached to. Inside the sensor housing 37, a pressure pulse wave sensor 46 is provided via a diaphragm 44 so as to be relatively movable and protrudable from an open end of the sensor housing 37.
A pressure chamber 48 is formed by the diaphragm 44 and the like. The pressure chamber 48 is supplied with pressurized air from an air pump 50 via a pressure regulating valve 52, whereby the pressure pulse wave sensor 46 has a pressing force corresponding to the pressure in the pressure chamber 48. It is pressed against the body surface 38. In this embodiment, the pressing force of the pressure pulse wave sensor 46 is indicated by the pressure in the pressure chamber 48 (unit: mmHg).

The sensor housing 37 and the diaphragm 44 constitute a pressing device 62 for pressing the pressure pulse wave sensor 46 toward the radial artery 56. The pressing device 62
_Presses the pressure pulse wave sensor 46 with an optimum pressing force P _HDPO described later. The screw shaft 41 and a motor (not shown) constitute a pressing position changing device that changes a pressing position where the pressure pulse wave sensor 46 is pressed in the width direction of the radial artery 56, that is, a width direction moving device 64. are doing.

The pressure pulse wave sensor 46 also functions as a second pulse wave detecting device. For example, a large number of semiconductor pressure-sensitive elements (not shown) are provided on a pressing surface 54 formed of a semiconductor chip made of single crystal silicon or the like. ) Are arranged at regular intervals of about 0.2 mm in the width direction of the radial artery 56, that is, in the direction of movement of the pressure pulse wave sensor 46 parallel to the screw axis 40, and are arranged on the body surface 42 of the wrist 43. The body surface 42 generated from the radial artery 56 by being pressed onto the radial artery 56
Detecting a differentially pressure oscillation wave That pressure pulse wave transmitted to and supplies a pressure-pulse-wave signal SM ₃ representing the pressure pulse wave through the A / D converter 58 to the arithmetic and control unit 28.

The CPU 29 of the arithmetic and control unit 28 has a ROM
The signal processing is executed using the storage function of the RAM 33 in accordance with the program stored in advance in the
A drive signal is output to the pressure control valve 52 through a drive circuit (not shown) to adjust the pressure in the pressure chamber 48. For example, during continuous blood pressure monitoring, the arithmetic and control unit 28 makes the part of the blood vessel wall of the radial artery 56 substantially flat based on the pressure pulse wave sequentially obtained in the process of slowly changing the pressure in the pressure chamber 48. The optimal pressure _PHDPO of the pressure pulse wave sensor 46 is determined, and the pressure regulating valve 52 is controlled so as to maintain the optimal pressure _PHDPO .

FIG. 3 is a functional block diagram for explaining a main part of the control function of the arithmetic and control unit 28 in the pressure pulse wave detecting device configured as described above. In the figure, the pressure sensor 14 detects the compression pressure of the cuff 10 that is changed by the cuff pressure control means 68 when measuring the blood pressure. The blood pressure value measuring means 70 sets the compression pressure by the cuff 10 to 2 to 3
A pulse synchronizing signal BP _SYS , an average blood pressure BP _MEAN , and a diastolic blood pressure BP _{DIA of a} living body according to an oscillometric method based on a pulse synchronizing signal obtained in a process of gradually changing the speed at about mmHg / sec, for example, a pulse wave amplitude. (Reference blood pressure value) is measured.

The optimum pressing position control means 72 determines that the position of the pressure pulse wave sensor 46 with respect to the radial artery 56 is greatly deviated and the difference between the maximum value and the minimum value of the pressure detecting elements arranged on the pressing surface 54 is the smallest. When a predetermined pressing position update condition (APS activation condition) is satisfied, such as when the larger one is located at the end of the array position, the pressing device 62
The pressure pulse wave sensor 46, is pressed at a sufficiently low preset relatively small first pressing value P ₁ than the optimum pressing force, pressure out of the pressure sensing elements of the pulse-wave sensor 46 in this state It is determined whether or not the pulse wave having the largest difference between the maximum value and the minimum value of the pulse wave is located at a predetermined central portion in the arrangement direction of the pressure detecting elements. If the judgment is negative, that is, if the pressure pulse wave sensor 46 is not located at the center, the pressure pulse wave sensor 46 is temporarily separated from the body surface 38 and the pressure pulse wave sensor 46 is moved, and then the above operation and judgment are executed again. I do. However, if the above determination is affirmed, the optimal pressing position has been obtained, so that the pressure detecting element that maximizes the difference between the maximum value and the minimum value of the pressure pulse wave is the central position pressure detecting element ( (Active element) and stores the optimum pressing force determining means 74
Allow the operation of

The optimum pressing force determining means 74 continuously changes the pressing force of the pressure pulse wave sensor 46 positioned at the optimum pressing position by the optimum pressing position control means 72, and obtains the pressure pulse wave obtained in the changing process. The optimum pressing force P _HDPO is determined based on The optimum pressing force maintaining means 75 presses the pressure pulse wave sensor 46 with the optimum pressing force P _HDPO determined by the optimum pressing force determining means 74. The optimum pressing force P _HDPO is, for example, as shown in FIG. 4, the pressure obtained from the active element of the pressure pulse wave sensor 46 in the process of continuously increasing the pressing force in a range sufficiently including the optimum pressing force P _HDPO. central flat portion formed by the curve connecting the lower peak value P _Mmin in a two-dimensional diagram showing a pressing force of the lower peak value P _Mmin and pulse-wave sensor 46 of the pulse wave signal SM ₃ (dashed line in FIG. 4) Of the radial artery 56 pressed by the pressure value within the predetermined range, the side of the blood vessel wall pressed by the pressure pulse wave sensor 46 is substantially flat. .

The pulse wave propagation velocity information calculating means 76 calculates the first pulse
It is generated at every pulse wave cycle detected by the wave detector
From a predetermined location to a location downstream of the first pulse wave detection device.
Of the pulse wave sequentially detected by the second pulse wave detection device
Based on the time difference to the specified part that occurs every cycle,
Calculation of pulse wave velocity information related to pulse wave velocity
Put out. For example, as shown in FIG.
From the R-wave of the electrocardiogram induced by
Rise point of the pressure pulse wave sequentially detected by the sensor 46
Time difference to (ie, lower peak point) (pulse wave transit time)
A time difference calculating means for sequentially calculating DT;
Based on the time difference DT sequentially calculated by the calculation means,
From equation 1 stored in advance, it propagates through the artery of the subject.
Pulse wave velocity V_M(M / sec) is calculated sequentially. still,
In Equation 1, L (m) is anterior from the left ventricle via the aorta.
The distance to the site where the pressure pulse wave sensor 46 is mounted.
, T _PEP(Sec) is aortic origin from R wave of electrocardiographic lead waveform
Precursor up to the rising or lower peak of the initial pulse wave
Period. These distance L and pre-ejection period T_PEPIs
It is a constant, and a value experimentally obtained in advance is used.

[0025]

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

The first correspondence determining means 78 is a means for measuring blood pressure.
Systolic blood pressure value BP measured by step 70_SYS・ Average blood pressure
Value BP_MEAN・ Diastolic blood pressure BP_DIA(Hereinafter, no particular distinction
If not, it is simply referred to as the blood pressure value BP. At least)
And within the blood pressure measurement period or immediately after the blood pressure measurement
Pulse wave propagation time DT or pulse wave velocity V after_MTo
Based on the pulse wave transit time shown in Equation 2 or Equation 3
DT or pulse wave velocity V_MAnd the measured blood pressure value B
The coefficients α and β in the relational expression with P are determined in advance.
Set. For example, measured by the blood pressure measurement unit 70
Systolic blood pressure BP _SYSAnd its pulse wave during blood pressure measurement
The average value of the propagation time DT is used as a set, and
Peak blood also determined in blood pressure measurement by step 70
Pressure value BP _SYSAnd another set of pulse wave pulse wave propagation time DT
Then, the coefficients α and β in the relational expression of Expression 2 are determined in advance.
I do.

[0027]

EBP = α (DT) + β (where α is a negative constant and β is a positive constant)

[0028]

EBP = α (V _M ) + β (where α is a positive constant, β is a positive constant)

The estimated blood pressure value determining means 80 calculates the blood pressure value of the living body.
Pulse wave propagation time DT or propagation velocity V of BP and its living body_M
From the above correspondence relationship (Equations 2 and 3) between
The actual body of the living body sequentially calculated by the wave propagation information calculating means 76
Pulse wave propagation time DT_RPOr the propagation speed V_MBased on
Estimated systolic blood pressure EBP_SYS・ Estimated systolic blood pressure EBP
_MEAN・ Estimated systolic blood pressure EBP_DIAAt least two of
Are sequentially determined.

The pressure pulse wave correcting means 81 comprises a second correspondence relation determining means 82, a monitoring blood pressure value determining means 84, an amplitude blood pressure ratio determining means 86, and a pressure pulse wave amplitude correcting means 88, and determines an estimated blood pressure value. Based on the estimated blood pressure value EBP determined by the means 80, the shape of the pressure pulse wave detected by the pressure pulse wave sensor 46 is sequentially corrected.

When the optimum pressing force P _HDPO is determined or updated by the optimum pressing force determining means 74, the second correspondence determining means 82 determines a plurality of pressures arranged on the pressing surface 54 of the pressure pulse wave sensor 46. based on the pressure pulse wave magnitude (intensity) P _M detected by the central position the pressure sensing element (active element) of the detecting element, and at least two estimated blood pressure EBP determined by the estimated blood pressure determining means 80 Te is predetermined to indicate the relation between the magnitude P _M of the pulse wave and monitoring blood pressure MBP, for example, in FIG. In FIG. 6, P _Mmin is the lowest value in a pulse wave for one beat.
_Mmax means the highest value in the pulse wave. Estimated blood pressure value EB
P is determined by the first correspondence relationship determining means 78 by the cuff 10
Is associated with the blood pressure value BP measured by the pressure pulse wave and the blood pressure value BP measured by the cuff 10 indirectly. Become. In FIG. 6, the correspondence is determined based on the estimated systolic blood pressure value EBP _SYS and the estimated diastolic blood pressure value EBP _DIA . However, in addition to these or in place of either one, the estimated average blood pressure value EBP
_MEAN may be used. In this case, the estimated average blood pressure value EBP _MEAN corresponds to the intensity indicated by the area center of gravity P _Mc of the pressure pulse wave.

[0032] correspondence between the said second relationship determining means 82 and the pressure pulse wave intensity P _M and monitoring blood pressure MBP is determined, the amplitude difference between two predetermined portions of the pressure pulse wave, It can be converted into the difference between the monitor blood pressure values MBP determined from the relationship on the basis of the magnitude P _M of the pressure pulse wave of the two sites. At the time when the correspondence is determined, the monitored blood pressure value MBP is equal to the estimated blood pressure value EBP. In this case, 2
For the difference ΔEBP between the two estimated blood pressure values, the monitoring blood pressure value (for example, ΔEBP) corresponding to the two estimated blood pressure values EBP
Is EBP _SYS -EBP _DIA , MBP _SYS , MBP
P _DIA ), the ratio of the difference ΔMBP, that is, the reference amplitude blood pressure ratio R
₀ is always “1”. Therefore, the second correspondence relationship determining means 82 functions as a special reference amplitude blood pressure ratio determining means that always sets the reference amplitude blood pressure ratio R ₀ to “1”.

The monitoring blood pressure value determining means 84 determines, for example, the center of the plurality of pressure detecting elements arranged on the pressing surface 54 of the pressure pulse wave sensor 46 from the correspondence determined in advance by the second correspondence determining means 82. based on the magnitude P _M of the pressure pulse wave detected by the position the pressure sensing element, monitoring the blood pressure value M
The BP is determined continuously. That is, since the magnitude of the pressure pulse wave is converted into the monitored blood pressure value MBP according to the correspondence shown in FIG. 6, for example, the minimum value P _{Mmin for} each beat of the sequentially detected pressure pulse wave is calculated as the monitored minimum blood pressure value. The maximum value P _{Mmax for} each beat is determined by the MBP _DIA and the monitored systolic blood pressure value MBP _SYS
Is determined.

The amplitude blood pressure ratio determining means 86 determines the difference between the two estimated blood pressure values ΔEBP sequentially determined by the estimated blood pressure value determining means 80 and the monitored blood pressure value MBP continuously determined by the monitored blood pressure value determining means 84. Estimated blood pressure EB
The ratio of the difference ΔMBP between the two monitored blood pressure values corresponding to P is sequentially determined as the amplitude blood pressure ratio R. The distortion value D is the ratio of the amplitude blood pressure ratio R sequentially determined by the amplitude blood pressure ratio determining means 86 to the reference amplitude blood pressure ratio R ₀ determined by the reference amplitude blood pressure ratio determining means 82 (= R / R ₀ ). In Although,
In this embodiment, since the reference amplitude blood pressure ratio R ₀ is “1”, the amplitude blood pressure ratio R directly becomes the distortion value D. Therefore, in the present embodiment, the amplitude blood pressure ratio determining means 86 also functions as a distortion value calculating means.

The pressure pulse wave amplitude correcting means 88 calculates the distortion value.
Distortion calculated by the output means (amplitude blood pressure ratio determining means) 86
Output from the pressure pulse wave sensor 46 based on the measured value D (= R)
The amplitude of the obtained pressure pulse wave is sequentially corrected. Amplitude blood pressure ratio determination
The amplitude blood pressure ratio R sequentially determined by the determination means 86 is a pressure pulse.
Pressure pulse signal SM output from the wave sensor 46_ThreePressure
If the pulse wave is not distorted, determine the optimal pressing force.
When the relationship is determined by the relationship determining means 82)
Similarly, it becomes "1". However, over time,
The optimal pressing force maintaining means determined by the appropriate pressing force determining means 74
Optimal pressing force P maintained by step 75_HDPOBut actually
In some cases, the optimal pressing force may not be obtained. Optimal
Pulse wave detected when pressed with non-pressing force
Signal SM _ThreeDoes not show an accurate pulse wave,
In the degree direction), the estimated blood pressure value EBP and
The monitored blood pressure values MBP no longer match. Therefore, the distortion value D
The pressure pulse wave is corrected based on the pressure pulse wave. That is, the pressure pulse
The wave correcting means 88 detects the pressure output from the pressure pulse wave sensor 46.
Pulse wave signal SM_ThreeIs multiplied by the strain value D to obtain the pressure
Correct the pulse wave waveform sequentially.

The corrected monitoring blood pressure value determining means 90 uses the correspondence determined in advance by the second correspondence determining means 82 to determine the magnitude of the pressure pulse wave whose amplitude has been corrected by the pressure pulse wave amplitude correcting means 88. based on the P _M, modified monitoring blood pressure CB
Determine P continuously. The waveform display means 92 causes the display 32 to sequentially display the corrected monitored blood pressure value CBP continuously determined by the corrected monitored blood pressure value determining means 90 in a graph.

The DS time calculating means 94 is provided with the pressure pulse wave sensor 4
The pressure pulse wave is pulse-wave signal SM ₃ the sequentially detected represented by 6, the time from the rising point in Ichimyaku wave to the peak point (systolic point), that is, sequentially calculates the DS time. This DS time represents the external working time of the myocardium. The abnormality determining means 96 activates the blood pressure measurement by the blood pressure measuring means 70 based on the fact that the estimated blood pressure value EBP determined by the estimated blood pressure value determining means 80 has exceeded a predetermined reference value. For example, the estimated blood pressure value determining means 80
The estimated blood pressure value EBP determined by the above is determined by a predetermined reference criterion value such as the previous cuff 1 by the blood pressure measuring means 70.
An abnormality in the blood pressure of the living body is determined based on a change in the blood pressure by a predetermined value or a predetermined ratio from the time when the blood pressure is measured by 0, and the blood pressure measurement by the blood pressure measuring means 70 is started.

FIGS. 7 to 9 are flowcharts for explaining the main part of the control operation of the arithmetic and control unit 28 of the pressure pulse wave detecting device. FIG. 7 shows the measurement of blood pressure by the cuff 10 and the accompanying pulse wave propagation velocity. FIG. 8 shows a blood pressure measurement routine in which the correspondence between the blood pressure and the blood pressure is determined.
9 shows a pressing state determination routine for determining the pressing state of FIG.

The blood pressure measurement routine of FIG. 7 is executed when the pressure pulse wave detecting device is activated, or when the activation of blood pressure measurement is determined in the main routine of FIG. First, in step SA1 (hereinafter, the steps are omitted), the rising point of the pressure pulse wave sequentially input by the pressure pulse wave sensor 46 is obtained from the R wave of the electrocardiographic lead waveform sequentially input by the electrocardiographic lead device 34. , Ie, the pulse wave propagation time DT (msec) is calculated.

Next, in SA2 and SA3 corresponding to the cuff pressure control means 68, the exhaust control valve 16 is switched to the pressure supply state and the air pump 18 is driven, so that the cuff 10 is rapidly measured for blood pressure measurement. with boosting is started, the cuff pressure P _C is whether a preset target pressing pressure P _CM than about 180mmHg is determined. If the determination in SA4 is denied, the above SA1
The following increase in the cuff pressure P _C is continued by is repeatedly executed.

[0041] However, the SA by increasing the cuff pressure P _C
If the determination of 3 is affirmative, the blood pressure measurement algorithm is executed in SA4 corresponding to the blood pressure value measurement means 70. That is, the air pump 18 is stopped and the exhaust control valve 16 is switched to the slow exhaust pressure state to decrease the pressure in the cuff 10 at a predetermined gentle speed of about 3 mmHg / sec, thereby reducing the slow pressure. The systolic blood pressure value BP _SYS , the average blood pressure value BP _MEAN , and the well-known oscillometric blood pressure value determining algorithm are based on the change in the amplitude of the pulse wave represented by the pulse wave signal SM ₁ sequentially obtained in the process.
And the diastolic blood pressure value BP _DIA is measured, and the pulse rate and the like are determined based on the pulse wave interval. Thereafter, the exhaust control valve 16 is switched to the rapid exhaust pressure state, and the inside of the cuff 10 is exhausted rapidly. At the same time, the measured blood pressure value BP and the pulse rate are displayed on the display 32.

Next, at SA5 corresponding to the first correspondence relationship determining means 78, the pulse wave transit time DT finally obtained at SA1 in the repetition of SA1 to SA3, and the blood pressure by the cuff 10 measured at SA4. A correspondence between the values BP _SYS and BP _DIA is determined. That is, when the blood pressure values BP _SYS and BP _DIA are measured in SA4, the blood pressure values BP _SYS and BP
_{Based on the DIA} and the pulse wave transit time DT, the pulse wave transit time D
T, estimated systolic blood pressure value EBP _SYS , and pulse wave transit time D
The correspondence (Equation 2) between T and the estimated diastolic blood pressure value EBP _DIA is determined. When the blood pressure measurement routine is executed based on the determination of the activation of the blood pressure measurement in the main routine of FIG. 9 described later, the pulse wave propagation time D obtained in the present main routine is obtained.
The correspondence is determined using T and the blood pressure value BP as one set, and the pulse wave transit time DT and the blood pressure value BP obtained in the previous main routine as another set. When the present apparatus is started, two sets of the relationship between the pulse wave propagation time DT and the blood pressure value BP are obtained by executing this routine twice in succession, and the above-mentioned correspondence is determined based on the two sets. It is determined.

When the correspondence between the pulse wave propagation time DT and the estimated blood pressure value EBP is determined or updated as described above, the pressing state determination routine of FIG. 8 is executed.

In FIG. 8, first, the optimal pressing position control means 7
SB1 and SB2 corresponding to No. 2 are executed. At SB1, it is determined whether a predetermined pressing position update condition (APS activation condition) is satisfied, for example, the pressing surface 54 of the pressure pulse wave sensor 46.
It is determined whether or not one of the pressure detection elements arranged in the array for detecting the maximum amplitude is located at the end of the arrangement position.

When the pressure position of the pressure pulse wave sensor 46 with respect to the radial artery 56 is deviated and the predetermined pressure position change condition (APS activation condition) is satisfied, for example, at the time of initial mounting, the above-described S is performed.
Since the determination of B1 is affirmative, the APS control routine of SB2 is executed. The APS control Le - Chin element to be the largest value difference between the maximum value and the minimum value of the pressure-pulse-wave signal SM ₃ respectively detected by the pressure detecting element of the pressure-pulse-wave sensor 46, the pressure detection element The optimal pressing position is determined so as to be approximately the center position of the center position, and the element is set as a center position pressure detecting element, that is, an active element.

On the other hand, if the determination in SB1 is negative, in subsequent SB3, for example, it is determined whether or not a body movement that changes the pressing condition of the pressure pulse wave sensor 46 to such an extent that the correspondence shown in FIG. 6 is changed is detected. Condition for updating the correspondence between the pressure pulse wave for continuous blood pressure monitoring and the estimated blood pressure value EBP, that is, HD for redetermining the optimal pressing force.
It is determined whether the P start condition has been satisfied.

If it is determined that there is no change in the pressing condition of the pressure pulse wave sensor 46 and the correspondence in FIG. 6 has not changed, the determination in SB3 is negative, and this routine is terminated. The main routine of FIG. 9 described later is executed. However, when the determination of SB3 is affirmed, and when the APS control routine of SB2 is executed,
Subsequently, the HDP control routine of SB4 corresponding to the optimum pressing force determining means 74 and the optimum pressing force maintaining means 75 is executed.

That is, in the process of continuously increasing the pressing force of the pressure pulse wave sensor 46, the maximum value _PMmax and the minimum value of the pressure pulse wave from the central position pressure detecting element located just above the radial artery 56 The pressing force that maximizes the difference from P _Mmin is the optimum pressing force P
_After being determined and updated as _HDPO , the pressure pulse wave sensor 4
The pressing force of _No. 6 is maintained at the optimum pressing force P _HDPO . Then, in the state where the pressure pulse wave sensor 46 is pressed by the optimum pressing force P _HDPO , the following SB5 and subsequent steps are executed.

At SB5, it is determined whether the R wave of the electrocardiographic waveform and one beat of the pressure pulse wave have been input. This SB5
If the determination is negative, the process waits by repeatedly executing SB5. If the determination is affirmative, the process proceeds to SB6 corresponding to the subsequent pulse wave propagation velocity information calculation means 76, in the same manner as SA1 in FIG. The pulse wave propagation time DT is calculated by the processing.

The following S corresponds to the estimated blood pressure value determining means 80.
In B7, the relationship between the pulse wave transit time DT and the estimated systolic blood pressure value EBP _SYS and the relationship between the pulse wave transit time DT and the estimated diastolic blood pressure value EBP _DIA determined in SA5 in FIG. Pulse wave transit time DT is substituted, the estimated systolic blood pressure value EBP _SYS and the estimated diastolic blood pressure value E
Each BP _DIA is determined.

[0051] In the subsequent second relationship determining means 82 corresponding to SB8, the magnitude of the pressure pulse wave input by the SB5 (the magnitude of the absolute value, ie the pressure-pulse-wave signal SM _3), is determined by the SB7 The corresponding relationship between the estimated blood pressure value EBP and the estimated blood pressure value EBP is determined and updated. That is, the minimum value of the pulse wave read in SB5 P _Mmin and the maximum value P _Mmax
Is determined, and based on the minimum value P _Mmin and the maximum value P _{Mmax of the} pressure pulse wave and the estimated diastolic blood pressure value EBP _DIA and the estimated systolic blood pressure value EBP _SYS determined at SB7, the pressure pulse shown in FIG. wave magnitude P _M and monitoring blood pressure MBP
Is determined.

[0052] As described above, when the relationship between the magnitude P _M of the pulse wave and monitoring blood pressure MBP is determined,
Alternatively, if the determination in SB3 is negative, the main routine shown in FIG. 9 is executed.

In FIG. 9, first, in SC1, it is determined whether an R wave of the electrocardiographic waveform and one beat of the pressure pulse wave have been input. While this determination is denied, the process is made to wait by repeatedly executing SC1. If the determination is affirmed, the SC corresponding to the subsequent pulse wave propagation velocity information calculating means 76 is executed.
In 2, the pulse wave propagation time DT is calculated by performing the same processing as SA1 in FIG. At SC3 corresponding to the estimated blood pressure value determining means 80, the pulse wave transit time DT and the estimated systolic blood pressure value EBP determined at SA5 in FIG.
_The pulse wave transit time DT calculated in SC2 is substituted into the relationship between _SYS and the pulse wave transit time DT and the estimated diastolic blood pressure value EBP _DIA, and the estimated systolic blood pressure value EBP _SYS and the estimated diastolic blood pressure value EBP _DIA is determined respectively.

In SC4 corresponding to the subsequent abnormality determining means 96, whether or not the estimated blood pressure value EBP determined in SC3 is abnormal is determined by, for example, the estimated systolic blood pressure value EBP _SYS . For example, the determination is made based on the fact that the state changed by a predetermined value or a predetermined ratio (for example, up and down 30%) from the time of the blood pressure measurement by the previous cuff continuously exceeds a predetermined number of beats, for example, 20 or more.

If the determination in SC4 is affirmative, the display 32 indicates an abnormality in the estimated blood pressure value EBP in the subsequent SC5, and then in order to obtain a reliable blood pressure value in FIG. In the blood pressure measurement routine, blood pressure measurement by the cuff is executed.

On the other hand, if the determination at SC4 is negative, the control proceeds to SC6 corresponding to the monitoring blood pressure value determining means 84, where the maximum value P _Mmax of the pressure pulse wave input at SC1 is obtained.
From the minimum value P _Mmin , the monitored systolic blood pressure value CBP _SYS and the monitored diastolic blood pressure value CBP _DIA are determined based on the pressure pulse wave blood pressure correspondence determined in SB8 of FIG.

Next, the SC corresponding to the distortion value calculating means 86
7, the estimated systolic blood pressure value EBP determined in SC3
Monitored systolic blood pressure value MBP _SYS determined in SC6 above for difference ΔEBP between _SYS and estimated diastolic blood pressure value EBP _DIA
Of the difference ΔMBP between the monitored diastolic blood pressure value MBP _DIA (ΔMP
BP / ΔEBP), that is, the amplitude blood pressure ratio R is calculated. In this embodiment, since the reference amplitude blood pressure ratio R ₀ is “1”, the amplitude blood pressure ratio R is determined as the distortion value D without any change.

S corresponding to the following pressure pulse amplitude correcting means 88
In C8, the intensity of the pressure pulse wave input with SC1 (i.e. the magnitude of the pressure pulse wave signal SM _3), by distortion value D calculated by the SC7 is applied, it is corrected amplitude of the pressure pulse wave is You. Therefore, in this flowchart, the SB8
And SC6 to SC8 correspond to the pressure pulse wave correcting means 81.

Further, the following corrected monitoring blood pressure value determining means 90
In step SC9, the correspondence determined by the accurate pressure pulse wave and the estimated blood pressure value EBP is determined in SB8 in FIG. 8 based on the magnitude P _M of the pressure pulse wave whose amplitude has been corrected in SC8. The correction monitoring blood pressure value CBP is continuously determined.

The SC corresponding to the following DS time calculation means 94
In 10, the time from the rising point of the pulse wave to the peak point, that is, the DS time is calculated based on the pressure pulse wave whose amplitude has been corrected in SC 8, and the calculated DS time is displayed on the display 32. Is displayed on the display part of. In SC11 corresponding to the subsequent waveform display means 92, S11
The corrected monitoring blood pressure value CBP determined in C9 is displayed on the display 32.
Is displayed as a graph. That is, the pressure pulse wave whose amplitude is corrected is displayed on the display 32. FIG. 10 is a diagram showing an example.

In the subsequent SC12, it is determined whether or not the elapsed time from the blood pressure measurement by the cuff 10 in the blood pressure measurement routine of FIG. 7 has passed a preset cycle of about 15 to 20 minutes, ie, a calibration cycle. Is determined. If the judgment of SC12 is denied,
The determination of the pressed state of the pressure pulse wave sensor 46 by the pressed state determination routine of FIG. 8, the correction of the waveform of the pressure pulse wave by the main routine, and the display of the corrected pressure pulse wave are performed for each beat. However, if the determination in SC12 is affirmative, it is time to re-determine the correspondence between the pulse wave transit time DT that periodically arrives and the blood pressure value BP, and the blood pressure measurement routine of FIG. 7 is executed again. Is done.

[0062] As described above, according to this embodiment, the pressure pulse wave correcting means 81 (SB8, SC6~SC8) by the estimated blood-pressure determining means 80 estimated blood pressure value determined by (SC3) EBP _SYS · EBP _Since the shape of the pressure pulse wave detected by the pressure pulse wave sensor 46 is sequentially corrected based on the _DIA , an accurate pressure pulse wave waveform can be sequentially obtained.

That is, according to the present embodiment, the second correspondence relationship determining means, that is, the reference amplitude blood pressure ratio determining means 82 (SB
8), the reference amplitude blood pressure ratio R ₀ to the estimated blood pressure of the amplitude of the pressure pulse wave at the time when the optimum pressing force P _HDPO is determined by the optimum pressing force determining means 74 (SB4) is set to “1”, and the amplitude blood pressure Ratio determining means, that is, distortion value calculating means 86
Two estimated blood pressure values E sequentially determined by (SC7)
The ratio of the difference ΔMBP between the monitored maximum blood pressure value MBP _SYS and the monitored minimum blood pressure value MBP _DIA sequentially determined by the monitored blood pressure value determining means 84 (SC6) to the difference ΔEBP between BP _SYS and EBP _DIA is determined as the amplitude blood pressure ratio R. Since the reference amplitude blood pressure ratio R ₀ is “1”, the amplitude blood pressure ratio R is determined as the distortion value D. Then, the pressure pulse wave amplitude correcting means 88 (SC8) provides the distortion value calculating means 86
Since the amplitude of the pressure pulse wave detected by the pressure pulse wave sensor 46 is sequentially corrected based on the distortion value D calculated by (SC7), an accurate pressure pulse wave waveform can be sequentially obtained.

Further, according to the present embodiment, the waveform display means 9
2 (SC11), the pressure pulse wave amplitude correction means 88 (SC
The accurate pressure pulse waveform corrected in step 8) is sequentially and graphically displayed on the display 32, so that the fluctuation of the blood pressure of the living body can be accurately monitored.

[0065] Further, according to this embodiment, by modifying the monitoring blood pressure determining means 90 (SC9), continuously determining the correction monitoring blood pressure CBP based on the magnitude P _M of the pressure pulse wave amplitude is corrected Therefore, there is an advantage that accurate blood pressure values can be continuously obtained.

Further, according to the present embodiment, the magnitude P _{M of the} pressure pulse wave used in the corrected monitoring blood pressure value determining means 90 (SC9) is determined by the second correspondence relation determining means 82 (SB8).
And modifying the correspondence relationship between the monitoring blood pressure CBP is two estimated blood pressure value determined by the pressure pulse wave magnitude P _M and the estimated blood pressure determining means 80 is detected by the PPW sensor 46 (SB7) Since it is determined in advance based on EBP _SYS and EBP _DIA , the corrected monitoring blood pressure value determining means 90 (SC
Since it is not necessary to execute the blood pressure measuring means 70 (SA4) for obtaining the blood pressure value BP measured using the cuff 10 in order to determine the preset relationship in 9), the relationship is determined quickly. There are advantages that can be done.

While 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.

[0068] For example, although in the foregoing embodiments, the second correspondence relationship determining unit 82, that the relationship between the size P _M of the pulse wave and monitoring blood pressure MBP is determined on the basis of the estimated blood pressure EBP , The reference amplitude blood pressure ratio R ₀ is the difference ΔMBP between the monitored blood pressure value and the difference ΔEBP between the two estimated blood pressure values.
Was always set to "1". However, the magnitude P _M of the pressure pulse wave is not converted to monitoring blood pressure MBP, the reference amplitude pressure ratio R ₀ with the size P _M direct pressure pulse wave may be determined. That is, the ratio of the amplitude difference between two predetermined portions of the pressure pulse wave detected by the pressure pulse wave sensor 46 to the difference ΔEBP between the two estimated blood pressure values may be determined as the reference amplitude blood pressure ratio R ₀ . Note that the predetermined two sites are, for example, a peak point and a rising point of the pressure pulse wave if the difference ΔEBP between the estimated blood pressure values is EBP _SYS −EBP _DIA . In this case, the amplitude blood pressure ratio determination means determines the ratio of the difference ΔEBP between the two sequentially determined estimated blood pressure values and the amplitude difference between the predetermined two portions of the sequentially detected pressure pulse wave as the amplitude blood pressure ratio R. The ratio (R / R ₀ ) of the amplitude blood pressure ratio R to the reference amplitude blood pressure ratio R ₀ is determined as the distortion value D by the distortion value calculating means.

In the above-described embodiment, the pressure pulse wave sensor 4
6 functions as a second pulse wave detecting device for calculating the pulse wave propagation time DT, but a volume pulse wave detecting device for detecting a volume pulse wave in a peripheral portion of a living body is used as the second pulse wave detecting device. You may be.

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 configuration of a pressure pulse wave detection device according to an embodiment of the present invention.

FIG. 2 is an enlarged view illustrating a pressure pulse wave detection probe of the embodiment of FIG. 1 with a part cut away.

FIG. 3 is a functional block diagram for explaining a main part of the function of the arithmetic and control unit in the embodiment of FIG. 1;

FIG. 4 is a view for explaining an optimum pressing force determined by an optimum pressing force determining means of FIG. 3;

FIG. 5 is a diagram illustrating a time difference DT obtained by a control operation of the arithmetic and control unit in the embodiment of FIG. 1;

FIG. 6 is a diagram exemplifying a correspondence relationship between the magnitude of a pressure pulse wave and a monitored blood pressure value used in the embodiment of FIG. 1;

FIG. 7 is a flowchart illustrating a main part of a control operation of the arithmetic and control unit according to the embodiment of FIG. 1, and illustrates a blood pressure measurement routine.

8 is a flowchart illustrating a main part of a control operation of the arithmetic and control unit according to the embodiment of FIG. 1, and illustrates a pressing state determination routine.

FIG. 9 is a flowchart illustrating a main part of a control operation of the arithmetic and control unit according to the embodiment of FIG. 1, and shows a main routine.

FIG. 10 is a diagram showing an example of a corrected monitored blood pressure value displayed as a graph on a display device.

[Explanation of symbols]

46: pressure pulse wave sensor 62: pressing device 70: blood pressure measuring means 74: optimum pressing force determining means 75: optimum pressing force maintaining means 76: pulse wave propagation velocity information calculating means 78: first correspondence relation determining means 80: estimated blood pressure Value determining means 82: Second correspondence relationship determining means (reference amplitude blood pressure ratio determining means) 86: Amplitude blood pressure ratio determining means, distortion value calculating means 88: Pressure pulse wave amplitude correcting means

Claims (1)

[Claims] 1. A pressure pulse wave detecting device for sequentially detecting a pressure pulse wave generated from an artery using a pressure pulse wave sensor pressed toward an artery of a living body, wherein the pulse wave propagation in the artery of the living body is provided. Estimated blood pressure value determining means for sequentially determining an estimated blood pressure value of the living body based on pulse wave propagation velocity information related to the velocity; and the pulse wave sensor based on the estimated blood pressure value determined by the estimated blood pressure value determining means. A pressure pulse wave correcting device for sequentially correcting the shape of the detected pressure pulse wave.