JPH1119054A - Pressing-correcting type continuous blood pressure monitoring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pressing-correcting type continuous blood pressure monitoring device wherein a blood pressure monitoring precision is kept even when a slack on the fitting belt of a pressure pulse wave sensor, and a habitual deformation or a recess at a pressed area by the pressure pulse wave sensor are generated during a continuous blood pressure monitoring. SOLUTION: In a continuous blood pressure monitoring using an presumed blood pressure, when it is judged that the pressing force of a pulse wave sensor 46 is shifted from an optimum pressing state by a pressing state shift judging means 84, the pressing force of the pulse wave sensor 46 is corrected in a manner to become optimum by an optimum pressing force correcting means 86 under a state wherein the pressing surface of the pulse wave sensor 46 is kept at an optimum position by an optimum pressing position control means 76. For this reason, the pressing force of the pressure pulse wave sensor 46 to a wrist is optimized without starting an optimum pressing position confirming operation, and an optimum pressing force determining operation, and the blood pressure monitoring is quickly continued.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-correcting continuous blood pressure for correcting an optimum pressing force of a pressure pulse wave sensor maintained for an artery while continuously monitoring a blood pressure value of a living body. It relates to a monitoring device.

[0002]

2. Description of the Related Art A pressure pulse wave sensor having a plurality of pressure detecting elements arranged in the width direction of an artery on a pressing surface for detecting a pressure pulse wave generated from an artery of a living body, and the pressure pulse wave sensor A pressing device that presses against the artery, and a pressure pulse wave sensor that is pressed by the pressing device with an optimum pressing force that is predetermined so that a part of a blood vessel wall of the artery is substantially flat, and the optimum pressing force. And an estimated blood pressure value for sequentially determining an estimated blood pressure value of the living body based on the magnitude of the pressure pulse wave detected by the pressure detecting element of the pressure pulse wave sensor from a preset relationship. There is known a continuous blood pressure monitoring device that includes value determination means and continuously monitors the blood pressure value of the living body based on the estimated blood pressure value. For example, this is a continuous blood pressure monitoring device described in Japanese Patent Application Laid-Open No. 8-187230.

[0003]

By the way, during the continuous blood pressure monitoring period of the continuous blood pressure monitoring device as described above,
Looseness of the wearing belt wearing the pressure pulse wave sensor on the living body,
Due to the conformational deformation or dent of the skin and the tissue immediately below the skin where the pressure pulse wave sensor is continuously pressed, it deviates from the optimum pressing state while being pressed by the initially determined optimum pressing force. Will occur,
There was a disadvantage that the accuracy of the monitoring blood pressure was reduced.

[0004] The present invention has been made in view of the above circumstances, and an object thereof is to loosen a belt for mounting a pressure pulse wave sensor or to determine a position pressed by a pressure pulse wave sensor during continuous blood pressure monitoring. An object of the present invention is to provide a pressure-correction-type continuous blood pressure monitoring device that maintains blood pressure monitoring accuracy even when conformational deformation or dent occurs.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the gist of the present invention is to detect a plurality of pressure pulses generated from an artery of a living body. A pressure pulse wave sensor having a pressure detection element on a pressing surface, a pressing device for pressing the pressure pulse wave sensor from the skin of a living body toward an artery, and a part of a blood vessel wall of the artery is substantially flat. An optimal pressing force control means for pressing the pressure pulse wave sensor by the pressing device with a predetermined optimum pressing force and maintaining the optimum pressing force, and a pressure detecting element of the pressure pulse wave sensor from a preset relationship. An estimated blood pressure value determining means for sequentially determining an estimated blood pressure value of the living body based on the magnitude of the detected pressure pulse wave, and a continuous blood pressure monitoring device for continuously monitoring the blood pressure value of the living body based on the estimated blood pressure value And ( a) In the state where the pressing force of the pressure pulse wave sensor is maintained at the optimum pressing force by the optimum pressing force control means and the estimated blood pressure value of the living body is determined by the estimated blood pressure value determining means, A pressing state shift determining means for determining a shift of the pressing state of the sensor against the artery from the optimum pressing state, and (b) the pressing state shift determining means determines the pressing force of the pulse wave sensor on the artery from the optimum pressing state. When the deviation is determined, the optimal pressing force of the pressure pulse wave sensor pressed by the pressing device, the optimal pressing force correction means for correcting so that the deviation from the optimal pressing state is reduced. , To include.

[0006]

As described above, during the continuous blood pressure monitoring based on the estimated blood pressure, the deviation of the pressing force of the pulse wave sensor on the artery from the optimal pressing state is determined by the pressing state deviation determining means. In this case, the optimal pressing force of the pressure pulse wave sensor pressed by the pressing device is corrected by the optimum pressing force correcting means so that the deviation from the optimum pressing state is reduced. Therefore, for example, during continuous blood pressure monitoring, even if the pressure belt for loosening the wearing belt of the pressure pulse wave sensor or conforming deformation or dent of the pressed portion by the pressure pulse wave sensor occurs and the pressing force for making the optimum pressing state is insufficient, The optimum pressing force correction means increases the pressing force of the pressure pulse wave sensor pressed by the pressing device from the previously maintained optimum pressing force and reduces the deviation from the optimum pressing state, so that the blood pressure monitoring accuracy is improved. Is maintained.

[0007]

In another aspect of the present invention, preferably, the estimated blood pressure value determining means is relatively lower than the optimum pressing force among a plurality of pressure detecting elements arranged on the pressing surface of the pressure pulse wave sensor. In the pressing force, the central position pressure detecting element is determined so that the element that outputs the maximum pulse wave amplitude becomes the center of the pressure element, and the magnitude of the pressure pulse wave detected by the central position pressure detecting element and the cuff are used. The estimated blood pressure value of the living body is sequentially determined from the magnitude of the pressure pulse wave output from the center position pressure detection element based on a relationship previously obtained with the reference blood pressure measurement value measured in advance.

[0008] Preferably, the pressing state shift judging means is such that the pressing force of the pressure pulse wave sensor is maintained at the optimum pressing force by the optimum pressing force control means, and the biological pressure is determined by the estimated blood pressure value determining means. In the state where the estimated blood pressure value is determined, a pressure value preset in the amplitude range of the pressure value detected by the central position pressure detecting element of the pressure pulse wave sensor is detected by the central position pressure detecting element. At the time, based on the pressure value detected by each pressure detection element, the pressure value and the pressure detection element in two-dimensional coordinates of a pressure axis indicating the pressure value and a position axis indicating the position of the pressure detection element Pressure distribution curve on the pressing surface indicating the relationship between the pressure distribution curve and the pressure distribution curve obtained when the optimum pressing force is determined or the corresponding relationship is determined, that is, the reference pressure component. It is to determine the deviation from the optimum pressing condition of the pressure sensor based on the difference between the curve.

[0009] Preferably, the pressing state shift determining means is arranged so that a shift between both ends of the reference pressure distribution curve with respect to both ends of the actual pressure distribution curve is within a predetermined judgment reference range. , It is determined that the optimal pressure state of the pressure pulse wave sensor is maintained. However, when both ends of the actual pressure distribution curve are higher than both ends of the reference pressure distribution curve, the actual pressing state is changed from the optimum pressing state to the pressing force increasing direction. When it is determined that the pressure pulse has deviated, the optimal pressing force correction means causes the pressing device to reduce the pressing force of the pressure pulse wave sensor. Further, when both ends of the actual pressure distribution curve are lower than both ends of the reference pressure distribution curve, the pressing state shift determination means changes the actual pressing state from the optimum pressing state to the pressing force decreasing direction. When it is determined that the pressure pulse has deviated, the optimal pressing force correction means causes the pressing device to increase the pressing force of the pressure pulse wave sensor.

[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 a continuous pressure monitoring device of the present invention, which monitors the condition of a patient during and after an operation and the living body during an exercise load test. Used to 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. A pressure sensor 14, an exhaust control valve 16, and an air pump 18 are connected to the cuff 10 via a pipe 20, respectively. The exhaust control valve 16 has three states: a pressure supply state that allows the supply of pressure into the cuff 10, 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 switchable between two states.

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. A blood pressure value (reference blood pressure value) such as a systolic blood pressure value and a diastolic blood pressure value is determined by an oscillometric method based on a change in the pulse wave represented by the wave signal SM ₁ , and the determined blood pressure value is displayed on the display 32.

As shown in detail in FIG. 2, the pressure pulse wave detecting probe 34 has a case 37 for accommodating a sensor housing 36 in the form of a container, and a probe 37 for moving the sensor housing 36 in the width direction of the radial artery 56. And a screw shaft 41 screwed to the sensor housing 36 and rotationally driven by a motor (not shown) provided in a driving portion 39 of the case 37. The case 37 has a mounting band 4
In the state where the opening end of the container-shaped sensor housing 36 faces the body surface 38 of the human body, the mounting band 40 can be attached to and detached from the side where the cuff 10 is not wound, for example, the left wrist 42. It can be attached to. Inside the sensor housing 36, 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 36.
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 36 and the diaphragm 44 constitute a pressing device 62 for pressing the pressure pulse wave sensor 46 toward the radial artery 56.
1 and a motor (not shown) are 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 6
4.

The pressure pulse wave sensor 46 has a pressing surface 54 made of a semiconductor chip made of, for example, single crystal silicon.
A large number of semiconductor pressure-sensitive elements (not shown) 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 shaft 41. By being pressed onto the radial artery 56 on the body surface 38 of the wrist 42, a pressure vibration wave or pressure pulse wave generated from the radial artery 56 and transmitted to the body surface 38 is detected, and the pressure pulse wave is detected. The pressure pulse wave signal SM ₂ representing the pulse wave is supplied to the arithmetic and control unit 28 via the A / D converter 58. Figure 3 shows an example of a pressure pulse wave SM ₂ detected by the PPW sensor 46.

The CPU 29 of the arithmetic and control unit 28 has a ROM
31 according to a program stored in advance in the RAM 33.
The signal processing is executed while utilizing the memory function, and the air pump 5
0 and the pressure regulating valve 52 are driven via a drive circuit (not shown).
A signal is output to adjust the pressure in the pressure chamber 48. Arithmetic
For example, when monitoring the continuous blood pressure,
Based on the pressure pulse wave sequentially obtained during the slow pressure change process in the chamber 48,
To make a part of the blood vessel wall of the radial artery 56 substantially flat.
Pressure P of the pressure pulse wave sensor 46_HDPODetermine that
Optimal pressing force P_HDPOControl the pressure regulating valve 52 to maintain
You. The arithmetic and control unit 28 performs measurement using the cuff 10.
Systolic blood pressure BP_SYSAnd diastolic blood pressure BP
_DIAAnd the optimal pressing force P_HDPOPressure pulse while maintaining
Of the radial artery 56 of the semiconductor pressure-sensitive elements of the wave sensor 46
The center position pressure detection element (active element
The maximum value P of the pressure pulse wave detected by_Mmaxand
Minimum value P _MminAnd the measured blood pressure value BP and pressure
Pulse wave size P_M(Absolute value)
From this correspondence, the pressure pulse wave sensor 46 sequentially detects
Pressure pulse wave size P_M(MmHg)
Peak value) P_MmaxAnd the lowest value (lower peak value) P_MminBased on
Blood pressure MBP_SYSAnd diastolic blood pressure MBP
_DIA(Estimated blood pressure value, that is, monitored blood pressure value) is sequentially determined,
The determined systolic blood pressure value MBP is displayed on the display 32._SYS
And diastolic blood pressure MBP_DIAIs displayed numerically for each beat,
A waveform indicating the estimated blood pressure value MBP is displayed continuously.

The above-mentioned correspondence is, for example, as shown in FIG. In this equation 1,
A is a constant indicating the slope, and B is a constant indicating the intercept.

[0019]

[Number 1] MBP = A · P _M + B

FIG. 5 is a functional block diagram for explaining a main part of the control function of the arithmetic and control unit 28 in the press-correction type continuous blood pressure monitoring device configured as described above. In the figure, at the time of blood pressure measurement, the compression pressure of the cuff 10 changed by the cuff pressure control means 68 is detected by the pressure sensor 14. The blood pressure value measuring means 70 performs the oscillometric method based on a pulse synchronization signal obtained in the process of gradually changing the compression pressure by the cuff 10 at a speed of about 2 to 3 mmHg / sec, for example, a pulse wave amplitude or a Korotkoff sound. measured systolic blood pressure value BP _SYS of a living body, the mean blood pressure value BP _{ME aN,} and the diastolic blood pressure BP _DIA (reference blood pressure value) in accordance with the Korotkoff sound technique.

The relation determining means 72 detects a central position pressure detecting element (active element) located just above the radial artery 56 among a plurality of pressure detecting elements arranged on the pressing surface 54 of the pressure pulse wave sensor 46. Pressure pulse wave size P
The correspondence between _M and the blood pressure value BP measured by the blood pressure value measuring means 70 is determined in advance, for example, as shown in FIG. Based on the correspondence, the estimated blood pressure value determination means 74 determines, for example, the magnitude of the pressure pulse wave detected by the active element among the plurality of pressure detection elements arranged on the pressing surface 54 of the pressure pulse wave sensor 46. Thus, the estimated blood pressure value MBP of the living body is continuously determined.

The optimum pressing position control means 76 detects the maximum amplitude of the pressure detecting elements arranged on the pressing surface 54 at the end of the arrangement position, such as at the time of initial mounting. If the predetermined pressing position update condition is satisfied, the pressing device 62 _{controls the} pressure pulse wave sensor 46 to a preset relatively small first pressing value P ₁ that is sufficiently smaller than an optimum pressing force P _HDPO described later. Pressed, and in that state, one of the pressure detecting elements of the pressure pulse wave sensor 46 which shows the maximum pulse wave amplitude is located at a substantially central portion set in advance in the arrangement direction of the pressure detecting elements. to decide. If the determination is denied, that is, if the element showing the maximum pulse wave amplitude is not located substantially at the center of the pressure detection element,
After the pressure pulse wave sensor 46 is once separated from the body surface 38 and the pressing device 62 and the pressure pulse wave sensor 46 are moved by the width direction moving device 64, the above operation and judgment are executed again. However, if the above judgment is affirmed,
That is, when the pressure detection element of the pressure pulse wave sensor 46 that shows the maximum pulse wave amplitude is located at a substantially central portion set in advance in the arrangement direction of the pressure detection elements, the optimum pressing position is obtained. In this state, the pressure detecting element that outputs the maximum pulse wave amplitude is set and stored as the central position pressure detecting element (active element), and the operation of the optimum pressing force control means 80 is permitted.

The optimum pressing force control means 80 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 76, and obtains the pressure pulse wave obtained in the changing process. The optimal pressing force P _HDPO is determined based on
The pressure pulse wave sensor 46 is pressed by the optimum pressing force P _HDPO .
Here, the optimum pressing force P _HDPO is, for example, as shown in FIG. 6, a predetermined range centered on the maximum value of the pulse wave amplitude obtained from the active element of the pressure pulse wave sensor 46 in the process of continuously increasing the pressing force. And / or the lower peak value S _Mmin of the pressure pulse wave signal SM ₂ obtained in the process of changing the pressing force.
And a pressing force of the pressure pulse wave sensor 46, a pressing value within a predetermined range centered on the center of a flat portion formed by a curve (dashed line in FIG. 6) connecting the lower peak value S _Mmin in the two-dimensional diagram. is there.

The reference pressure distribution curve storage means 82 determines that the pressing force detected by, for example, the active element at the time of determining the optimal pressing force P _HDPO is within the amplitude range of the present blood pressure fluctuation range (%) of the living body. When the pressure value is preset to be sufficiently inside, for example, a pressure corresponding to 90% of the maximum pulse wave amplitude, that is, a value obtained by adding 90% of the pulse pressure to the estimated diastolic blood pressure value MBP _DIA. The pressure distribution curve with the pressure (pressure signal SM ₂ ) detected by each pressure detection element when the pressure becomes equivalent to the vertical axis and the horizontal axis with the position of the pressure detection element is a reference pressure distribution curve ( (Reference pressure tonogram).

The pressing state shift judging means 84 maintains the pressing position of the pressure pulse wave sensor 46 at the optimum pressing position by the optimum pressing position control means 76, and controls the pressure pulse wave sensor 46 by the optimum pressing force control stage 80. Pressing force is optimal pressing force P
_HDPO is maintained, and in the state where the estimated blood pressure value of the living body is sequentially determined by the estimated blood pressure value determination means 74,
The deviation between the actual pressure distribution curve of the pressure pulse wave sensor and the reference pressure distribution curve at the time of pressing with the optimum pressing force P _HDPO stored in the reference pressure distribution curve storage means 82 is determined. That is, the pressing state shift determining means 84
At the time when the pressing force detected by the active element becomes the same as the pressing force at the time of determining the reference pressure distribution curve, the actual pressure distribution curve created based on the pressure pulse waves respectively detected by each pressure detecting element _Is determined based on the deviation between both ends of the pressure distribution curve and both ends of the reference pressure distribution curve stored at the time of setting the optimum pressing force P _HDPO by the reference pressure distribution curve storage means 82. The pressure deviation is determined.

For example, the pressing state shift determining means 84
As shown in FIG. 7, the difference between the both ends of the reference pressure distribution curve (solid line) and the both ends of the pressure distribution curve (dashed line), that is, the pressure difference is within a predetermined judgment reference range (for example, ± If it is 5 mmHg), it is determined that there is no deviation between the pressed state when the reference pressure distribution curve is determined and the current pressed state, that is, the pressing force is appropriate.
Note that FIG. 7 is a diagram in which attention is paid only to both ends of the pressure distribution curve, and the pressure difference between both ends is characteristically represented (the same applies to FIGS. 8, 9 and 10). Also, as shown in FIG.
The deviation between the both ends of the reference pressure distribution curve (solid line) and both ends of the pressure distribution curve (dashed line) exceeds a preset range,
If both ends of the pressure distribution curve are higher than both ends of the reference pressure distribution curve, it is determined that the pressing force of the pressing device 62 has shifted from the optimum pressing state in the pressing force increasing direction. Further, as shown in FIG. 9, the difference between both ends of the reference pressure distribution curve (solid line) and both ends of the pressure distribution curve (dashed line) exceeds a preset range, and both ends of the pressure distribution curve are set to the reference. If the pressure is lower than both ends of the pressure distribution curve, it is determined that the pressing force of the pressing device 62 has shifted from the optimal pressing state in the pressing force decreasing direction. Further, as shown in FIG. 10, the deviation between both ends of the reference pressure distribution curve (solid line) and both ends of the pressure distribution curve (dashed line) exceeds a preset range, and one end of the pressure distribution curve is set as a reference. If the pressure is higher than the end on the same side of the pressure distribution curve and the other end is lower than the end on the same side of the reference pressure distribution curve, it is determined that it cannot be eliminated by simple pressing force correction.

When the pressing state shift determining means 84 determines that a pressing state shift has occurred, the optimum pressing force correcting means 86 determines whether both ends of the reference pressure distribution curve and both ends of the actual pressure distribution curve are correct. The pressing force of the pressing device 62 pressing the pressure pulse wave sensor 46 is corrected according to the degree of the deviation of the pressing state so that the difference between the pressure states is eliminated, that is, the deviation from the optimal pressing state is reduced. . For example, as shown in FIG. 8, when the pressing force of the pressing device 62 deviates from the optimum pressing state in the pressing force increasing direction, the pressing device 62 pressing the pressure pulse wave sensor 46 according to the degree of the deviation. As shown in FIG. 9, when the pressing force of the pressing device 62 deviates from the optimal pressing state in the pressing force decreasing direction, as shown in FIG.
As shown in FIG. 10, if the deviation cannot be completely eliminated by simple correction of the pressing force, as shown in FIG. The pressing force of the pressing device 62 pressing the pressure pulse wave sensor 46 is corrected so that the deviation from the both ends of the pressure distribution curve is minimized.

FIGS. 11 and 12 show the arithmetic and control unit 28.
It is a flowchart for explaining the main part of the control operation of,
FIG. 11 shows a main routine, and FIG. 12 shows a pressing force correction control routine for correcting the pressing force of the pressure pulse wave sensor 46 when the operation of determining the estimated blood pressure is continuously performed.

In step S1 of FIG. 11 (hereinafter, the steps are omitted), it is determined whether or not it is the first execution of S1, and the elapsed time since the last time the correspondence was updated is several ten minutes to several tens. It is determined whether or not the preset calibration cycle has been exceeded by about a minute. Normally, the determination in S1 is denied, so whether a predetermined pressing position update condition (APS activation condition) is satisfied in S2, for example,
It is determined whether or not the pressure detection element that detects the maximum amplitude among the pressure detection elements arranged on the pressing surface 54 of the pressure pulse wave sensor 46 is positioned at the end of the arrangement position.

If the pressure position of the pressure pulse wave sensor 46 on the radial artery 56 is within the normal range, the judgment in S2 is denied. In S3, for example, the pressure pulse wave Based on whether a body motion that changes the pressing condition of the sensor 46 has been detected, or whether the monitored blood pressure value MBP has changed significantly with respect to the blood pressure value BP measured using the previous cuff 10 or the like. Then, it is determined whether the activation condition for updating the correspondence for blood pressure monitoring or the optimal pressing force determination activation condition (HDP activation condition) is satisfied.

There is no change in the pressing condition of the pressure pulse wave sensor 46.
And it is considered that the correspondence in FIG. 4 has not changed.
Is denied in S3, so one in S8
It is determined whether or not the pressure pulse wave is generated by the pressure pulse signal SM._Two Based on
Is determined. If the determination at S8 is negative, S
1, S2, S3, S8 are repeatedly executed
Let me wait more. However, one pressure pulse wave is generated,
If the determination in S8 is affirmative, the estimated blood pressure value determining means 7
In S9 corresponding to 4, the optimal pressing force P_HDPOPress at
Active element of the pressure pulse wave sensor 46
Pressure pulse wave signal SM _Two From the highest value P of the wave_MmaxYou
And minimum value P_MminIs determined, and from the correspondence shown in FIG.
Maximum value P of pressure pulse wave_MmaxAnd the lowest value P_MminBased on
Constant systolic blood pressure MBP_SYSAnd estimated diastolic blood pressure MBP
_DIAIs determined, and is sequentially displayed on the display 32 for each beat.
4 and the pressure pulse wave signal SM in FIG._Two Determined from
The continuous waveform of the estimated blood pressure value is displayed on the display 32.
You.

While the above steps are repeatedly executed, if the time elapsed since the last time the correspondence was determined exceeds the calibration cycle set in advance, the above S1 is executed.
Is affirmative, the blood pressure measurement using the cuff 10 is executed in S6, the correspondence is updated in S7, and the above-mentioned S8 and thereafter are executed. That is,
First, in S6 corresponding to the blood pressure value measuring means 70, the exhaust control valve 16 is switched to the pressure supply state and the air pump 18 is operated to set the pressure in the cuff 10 to a target higher than the expected maximum blood pressure value of the patient. Pressure (eg 180mmHg)
After the pressure has been increased to a predetermined value, the air pump 18 is stopped and the exhaust control valve 16 is switched to the slow exhaust pressure state to lower the pressure in the cuff 10 at a predetermined slow pressure decreasing speed of about 3 mmHg / sec. The systolic blood pressure value BP _SYS and the average blood pressure value B are determined according to the well-known oscillometric blood pressure value determination algorithm based on the change in the amplitude of the pressure pulse wave represented by the pulse wave signal SM ₁ sequentially obtained in this slow pressure lowering process.
P _MEAN and the diastolic blood pressure value BP _DIA (reference blood pressure value) are measured, and the pulse rate and the like are determined based on the pulse wave interval. Then, the measured blood pressure value, the pulse rate, and the like are displayed on the display 32, and the exhaust control valve 1
6 is switched to the rapid exhaust pressure state, and the inside of the cuff 10 is quickly exhausted.

Next, S corresponding to the relation determining means 72
In 7, the pressure pulse wave pressure pulse wave in the size of the active elements of the sensor 46 (absolute value, that the pressure-pulse-wave signal SM size of ₂₎ and the blood pressure value by the cuff 10 as measured in the above S6 BP _SYS, BP _DIA Is determined and updated. That is, one pulse of the pressure pulse wave from the active element of the pressure pulse wave sensor 46 is read, the maximum value _PMmax and the minimum value _PMmin of the pressure pulse wave are determined, and the maximum value _{PMmax of the} pressure pulse wave is determined. And the lowest value P
_Systolic blood pressure value B measured by cuff 10 at _Mmin and S6
The correspondence between the magnitude of the pressure pulse wave and the blood pressure value shown in FIG. 4 is determined based on P _SYS and the diastolic blood pressure value BP _DIA .

When the pressing position of the pressure pulse wave sensor 46 with respect to the radial artery 56 deviates and the predetermined pressing position change condition (APS activation condition) is satisfied, such as at the time of initial mounting, the above-described S is performed.
Since the determination of step 2 is affirmative, the APS control routine of S4 corresponding to the optimal pressing position control means 76 is executed. The APS control routine generates a pressure pulse wave signal SM detected by each pressure detecting element of the pressure pulse wave sensor 46.
_The element for detecting the maximum amplitude of the amplitude distribution curve of _2, the optimum pressing position is determined so as to be substantially the center position of the pressure detection element, and the element for detecting the maximum amplitude at that time is the center position pressure detection element, After the pressure pulse wave sensor 46 is set as the active element and the pressure pulse wave sensor 46 is positioned at the optimum pressing position, the pressing force of the pressure pulse wave sensor 46 is continuously In the process of increasing the radial artery 5
The pressure at which the amplitude of the pressure pulse wave detected by the active element positioned directly above the pressure pulse 6 becomes the maximum is determined and updated as the optimum pressure _PHDPO , and the pressure pulse wave sensor 4
The pressing force of _No. 6 is maintained at the optimum pressing force P _HDPO . Then, in a state where the pressure pulse wave sensor 46 is pressed by the optimum pressing force P _HDPO , the following S6 and subsequent steps are executed. Also,
If it is determined in S2 that the pressure position of the pressure pulse wave sensor 46 is appropriate, that is, the determination in S2 is denied, and the determination in S3 is affirmative in a state where blood pressure monitoring is continuously performed, The following steps of the HDP control routine of S5 are executed.

Hereinafter, in the main routine, during the operation in which the pressing force of the pressure pulse wave sensor 46 is held at the optimum pressing force P _{HDPO and} the blood pressure value of the living body is continuously monitored, that is, S1, S2, S3 , S8, and S9 are repeatedly executed, when a shift occurs in the pressing force of the pressure pulse wave sensor 46, the degree of the shift of the pressing force of the pressure pulse wave sensor 46 is determined, and the pressing force is optimized. A pressing force correction control routine for correcting the pressure will be described with reference to FIG.

In SS1 of FIG. 12, it is determined whether or not the update of the correspondence shown in FIG. 4 (cuff calibration) has been executed in S7 corresponding to the relation determining means 72, or in S5 corresponding to the optimum pressing force control means 80. It is determined whether or not the optimum pressing force P _HDPO of the pressure pulse wave sensor 46 has been updated. If the determination in SS1 is denied, the pressing force of the pressure pulse wave sensor 46 is held at the optimum pressing force P _HDPO , and SS3 and subsequent steps are executed. However, when the determination of SS1 is affirmed, in SS2 corresponding to the reference pressure distribution curve storage means 82, the pressure distribution curve when the correspondence is updated or the optimal pressing force P _HDPO is updated. The pressure distribution curve is stored as a reference pressure distribution curve. This reference pressure distribution curve serves as a reference for determining the deviation of the pressing force.

Next, in SS3, in order to remove the fluctuation value, the average calculation of the pressure distribution curve obtained for each beat after the previous determination of the deviation of the pressing force or after the update of the correspondence relationship is executed, An average pressure distribution curve averaged within a predetermined time is obtained. Then, in SS4, whether contents "N" number of beats counter CN for counting the number of beats it has become a preset determination reference value N _M or more is determined. The criterion value N _M corresponds to the shift determination cycle,
A value corresponding to several to several tens of beats is set. This SS4
Then, it may be determined whether or not the elapsed time since the previous deviation determination has reached a predetermined reference time.

At first, since the determination at SS4 is denied, the content "N" of the beat counter CN is determined at SS5.
After "1" is added to the above, SS3 and subsequent steps are executed again. Then, while the above SS3 to SS5 are repeatedly executed, when the determination of the above SS4 is affirmed, the average pressure distribution curve with respect to both ends of the reference pressure distribution curve is determined in SS6 corresponding to the pressing state deviation determination means 84. The deviation of both ends is determined.

Here, the method of judging the deviation of the pressing state is based on the average pressure distribution with respect to both ends of the reference pressure distribution curve stored when the correspondence is updated or when the optimum pressing force P _HDPO is updated last time. Judgment is made based on the deviation of both ends of the curve. For example, as shown in FIG. 7, both ends of the reference pressure distribution curve (solid line) and the average pressure distribution curve (dashed line)
Is within a predetermined reference range (for example, ± 5 mmHg), the pressing force is appropriate, that is, the pressing force when the reference pressure distribution curve is determined and the current pressing state. Judge that there is no deviation from SS6
Is denied. Then, in SS7, the pressing force of the pressure pulse wave sensor 46 is maintained at the pressing force up to that time.

However, when the determination in SS6 is affirmed, in SS8 corresponding to the optimal pressing force correction means 86, the deviation from the optimal pressing state is reduced according to the degree of deviation determined in SS6. The pressing force of the pressing device 62 is corrected. For example, as shown in FIG. 8, when both ends of the average pressure distribution curve (broken line) are higher than both ends of the reference pressure distribution curve (solid line), the pressing force of the pressing device 62 is changed from the optimum pressing state. It is determined that the pressing force has increased in the increasing direction, and the pressing force of the pressing device 62 is reduced according to the degree of the deviation so that the difference between both ends of the reference pressure distribution curve and both ends of the average pressure distribution curve is eliminated. Rara.
Further, as shown in FIG. 9, when both ends of the average pressure distribution curve (broken line) are lower than both ends of the reference pressure distribution curve (solid line), the pressing force of the pressing device 62 is in the optimum pressing state. The pressing force of the pressing device 62 is determined according to the degree of the deviation so that the difference between both ends of the reference pressure distribution curve and both ends of the average pressure distribution curve is eliminated. Strengthen. Further, as shown in FIG. 10, when the pressing position of the pressing surface 54 of the pressure pulse wave sensor 46 is shifted and the active element is shifted from directly above the radial artery 56, the average pressure distribution curve (dashed line) One end has a higher pressure than the end on the same side of the reference pressure distribution curve (solid line), and the other end has a lower pressure than the end on the same side of the reference pressure distribution curve. In this case, the pressing force of the pressing device 62 is corrected so that the displacement between both ends is minimized. Then, in subsequent SS12, the pressure distribution curve obtained at the time of correcting the pressing force is updated as the reference pressure distribution curve.

As described above, according to the present embodiment, during continuous blood pressure monitoring using the estimated blood pressure, the pressing state shift determining means 84 (SS6) determines the pressing force of the pressure pulse wave sensor 46 on the wrist 42. If the deviation is determined, the deviation of the pressing force of the pressure pulse wave sensor 46 is corrected by the optimum pressing force correction means 86 (SS8) so that the deviation from the optimum pressing state is reduced. For this reason, the optimal pressing position confirmation operation and the optimal pressing force determination operation are not started,
Since the pressing force of the pressure pulse wave sensor 46 on the wrist 42 is optimized, the blood pressure monitoring is immediately continued.

Further, according to the present embodiment, the depressed state shift judging means 84 (SS6) uses the estimated blood pressure value deciding means 74 (S6).
In the state where the estimated blood pressure value of the living body is continuously determined according to 9), the average value of the pressure distribution curve obtained from the sequential pressure pulse wave sensor 46, that is, both ends of the average pressure distribution curve, is updated at the time of updating the correspondence or the previous time. The deviation of the pressing state of the pressing surface is determined based on the deviation from both ends of the reference pressure distribution curve obtained at the time of the pressing force correction. The determination of the shift in the pressed state is such that if the degree of the shift is within the reference value, the pressing force is maintained, the degree of the shift exceeds the reference value, and the above-mentioned reference pressure distribution curve is more than both ends. When both ends of the average pressure distribution curve are high pressure, the pressing force of the pressing device is reduced by the optimum pressing force correcting means 86 (SS8) in a direction in which the deviation from the optimum pressing state decreases.
If both ends of the average pressure distribution curve have lower pressures than both ends of the reference pressure distribution curve, the optimum pressing force correcting means 86 (SS8) presses in a direction to reduce the deviation from the optimum pressing state. One end of the average pressure distribution curve is a pressure higher than the end of the same side of the reference pressure distribution curve, and the other end is the same end of the reference pressure distribution curve. When the pressure is lower, the pressing force of the pressing device 62 is corrected so that the displacement between both ends is minimized. Therefore, there is an advantage that the deviation of the pressure state of the pressure pulse wave sensor 46 can be determined relatively accurately and easily.

Further, according to the present embodiment, the reference pressure distribution curve and the actual pressure distribution curve indicate that the pressure detected by the center position pressure detecting element at the time of determining the optimum pressing force is the fluctuation width (pulse wave amplitude). Since it is determined from the detected pressure value of each pressure detecting element at the moment when the pressure value determined in
Since the pressure distribution curve is not affected by the blood pressure fluctuation of the living body, there is an advantage that the accuracy of the correction of the optimal pressing force can be improved.

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

For example, in the embodiment of FIG. 12 described above, SS2, SS4 and SS for calculating the average pressure distribution curve are used.
Although 5 is provided, it is not always necessary to provide it.

In the above embodiment, the cuff 10 is attached to the upper arm and the pressure pulse wave sensor 46 is attached to the wrist to detect the pressure pulse wave of the radial artery. The pressure pulse wave sensor 46 wound around the leg may be attached to the foot to detect the pressure pulse wave of the dorsal foot artery of the leg on which the cuff 10 is not wound.

In the above-described embodiment, when the pressing force of the pressure pulse wave sensor 46 is changed by the optimum pressing force correcting means 86, and when the estimated blood pressure changes by a predetermined value or a predetermined ratio or more, the blood pressure is changed. S6 and subsequent steps corresponding to the value determining means 70 may be automatically performed.

In the above-described embodiment, the pressing force detected by each pressure detecting element when the pressing force detected by the active element becomes a pressure corresponding to 90% of the maximum pulse wave amplitude is used. Although the reference pressure distribution curve was calculated, the pressure detected from the active element at the time of calculating the reference pressure distribution curve is 90% of the maximum pulse wave amplitude.
The pressure is not limited to 80% or 20%. Even if the blood pressure of the living body fluctuates, it is sufficient that the pressure is detected by the active element.
That is, the pressure pulse wave of the active element at the time when the reference pressure distribution curve was calculated should not be a value close to the maximum value _PMmax or a value close to the minimum value _PMmin .

The present invention can be variously modified without departing from the gist thereof.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a pressure-correction type continuous blood pressure monitoring 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 diagram illustrating a pressure pulse wave detected by the pressure pulse wave sensor of the embodiment of FIG. 1;

FIG. 4 is a diagram illustrating a correspondence relationship used in the embodiment of FIG. 1;

FIG. 5 is a functional block diagram for explaining a main part of a control function of the arithmetic and control unit according to the embodiment of FIG. 1;

FIG. 6 is a diagram illustrating an optimum pressing force determined by an optimum pressing force control unit in FIG. 5;

FIG. 7 is a view for explaining the content of the shift determination by the pressing state shift determining means in FIG. 5, and is a view for explaining a case where the pressing force of the pressure pulse wave sensor is appropriate.

8 is a diagram for explaining the content of the shift determination by the pressing state shift determining means in FIG. 5, and is a diagram for explaining a case where the pressing force of the pressure pulse wave sensor is shifted from the optimum pressing state in the pressing force increasing direction. is there.

9 is a diagram for explaining the content of the shift determination by the pressing state shift determining unit in FIG. 5, and is a diagram for explaining a case where the pressing force of the pressure pulse wave sensor is shifted from the optimum pressing state in the pressing force decreasing direction. is there.

FIG. 10 is a diagram for explaining the content of the shift determination by the pressed state shift determining means in FIG. 5, and is a diagram for explaining a case where the pressed position of the pressure pulse wave sensor is shifted.

11 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. 12 is a flowchart showing a pressing state shift correction control routine repeatedly executed in parallel with the main routine of FIG. 11;

[Description of sign]

 10: Cuff 42: Wrist (living body) 46: Pressure pulse wave sensor 56: Radial artery (artery) 62: Pressing device 64: Width moving device 76: Optimal pressing position control means 80: Optimal pressing force control means 82: Reference Pressure distribution curve storage means 84: Press state deviation determination means 86: Optimal pressing force correction means

Claims (1)

[Claims] 1. A pressure pulse wave sensor having a plurality of pressure detecting elements arranged on a pressing surface in a width direction of an artery for detecting a pressure pulse wave generated from an artery of a living body, and the pressure pulse wave sensor. A pressing device that presses from the skin of the living body toward the artery,
Optimum pressing force control means for pressing the pressure pulse wave sensor by the pressing device with an optimum pressing force determined in advance so that a part of the blood vessel wall of the artery is substantially flat, and maintaining the optimum pressing force; Estimated blood pressure value determining means for sequentially determining the estimated blood pressure value of the living body based on the magnitude of the pressure pulse wave detected by the pressure detecting element of the pressure pulse wave sensor from the set relationship, the estimated blood pressure value A continuous blood pressure monitoring device for continuously monitoring the blood pressure value of the living body, wherein the pressing force of the pressure pulse wave sensor is maintained at the optimum pressing force by the optimum pressing force control means and the estimated blood pressure value determining means A pressure state deviation determining means for determining a deviation of the pressure state of the pulse wave sensor from the optimal pressure state from the optimal pressure state in a state in which the estimated blood pressure value of the living body is determined; When the deviation of the pressing force of the pulse wave sensor against the artery from the optimal pressing state is determined, the optimal pressing force of the pressure pulse wave sensor pressed by the pressing device is changed to the optimum pressing state. A pressure-correction type continuous blood pressure monitoring device, comprising: an optimum pressing force correction unit that corrects the deviation from the pressure.