JP2798750B2 - Pulse wave detector - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a pulse wave detection device that detects a pulse wave by pressing an artery of a living body.

2. Description of the Related Art A pulse wave sensor and pressure means for pressing the pulse wave sensor onto an artery on the surface of a living body with fluid pressure, and after setting the fluid pressure of the pressure means to an optimum fluid pressure, the pulse wave sensor There is known a pulse wave detecting device that sequentially detects a pulse wave generated from an artery. For example, this is described in Japanese Utility Model Application Laid-Open No. 64-12505, which was previously filed by the present applicant.

However, in such a pulse wave detection device, when a pulse wave sensor and a living body on which the pulse wave sensor is pressed relatively move due to body movement of a living body, the state of the artery being pressed by the pulse wave sensor is reduced. In some cases, the pulse wave cannot be suitably detected.

The present invention has been made in view of such circumstances, and its purpose is to detect the relative movement between the pulse wave sensor and the living body during the pulse wave detection, and to detect the movement. It is an object of the present invention to provide a pulse wave detecting device capable of canceling pulse wave data at the time of occurrence and detecting a suitable pulse wave at all times.

Means for Solving the Problems In order to achieve the above object, the present invention relates to a pulse wave detecting device of the type described above, wherein (a) the pressure A fluid pressure change amount calculating means for sequentially calculating a change amount per predetermined time of the fluid pressure generated in synchronization with a pulse after the fluid pressure of the means is set to the optimum fluid pressure, and (b) the fluid Motion detection for detecting that a relative motion has occurred between the pulse wave sensor and the living body when the change amount of the fluid pressure calculated by the pressure change amount calculation means exceeds a predetermined value. Means.

According to the pulse wave detection device having such a configuration, after the fluid pressure of the pressing unit that presses the pulse wave sensor onto the artery on the surface of the living body is set to the optimum fluid pressure, the pulse wave sensor is synchronized with the pulse. The amount of change in the fluid pressure generated per predetermined time is calculated sequentially by the fluid pressure change amount calculating means, and when the amount of change in the fluid pressure exceeds a predetermined value, the pulse wave sensor and the It is detected by the motion detecting means that a relative movement has occurred between the living body and the pressed body, so that the pulse wave data detected when the movement occurs can be canceled, and a preferable pulse wave is always obtained. Can be detected.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a diagram showing a configuration of a blood pressure monitoring device provided with the pulse wave detection device of the present invention. In the figure, reference numeral 10 denotes a rubber bag-shaped cuff which is wound around the upper arm 12 of a human body and presses the same. The cuff 10 has a pressure sensor 14, a switching valve 16,
And an electric pump 18 are connected via a pipe 20. The electric pump 18 supplies a fluid such as air into the cuff 10 and pressurizes it. The pressure sensor 14 detects a pressure (cuff pressure) in the cuff 10 and indicates a cuff pressure signal SK indicating the cuff pressure.
Is output to the CPU 24 via the A / D converter 22. The switching valve 16 is
A pressure supply state that allows the supply of pressure into the cuff 10
The state can be switched between three states, that is, a gradual exhaust state in which the inside of the cuff 10 is gradually exhausted and a rapid exhaust state in which the inside of the cuff 10 is quickly exhausted.

The CPU 24 is connected to the ROM 26, the RAM 28, and the output interface 30 via a data bus line, executes signal processing while utilizing the storage function of the RAM 28 according to a program stored in the ROM 26 in advance, and controls driving circuits (not shown), respectively. The cuff pressure is adjusted by controlling the electric pump 18 and the switching valve 16 through the cuff 10, and the systolic blood pressure is controlled based on the change in the magnitude of the fluctuation component of the cuff pressure detected in the step of reducing the pressure in the cuff 10. Determine the value and the diastolic blood pressure value.

On the other hand, a pulse wave detection probe 33 is attached to the wrist 32, as shown in FIGS. The pulse wave detection probe 33 is a housing 34 having a bottomed cylindrical shape.
And fixed to the inner wall of the housing 34
A diaphragm 40 forming a pressure chamber 44 therein, and a pulse wave sensor 42 which is fixed to a surface of the diaphragm 40 opposite to the pressure chamber 44 side and can protrude from an open end of the housing 34, is configured. The pulse wave sensor 42 is on the body surface 36 of the wrist 32
A band 38 provided on the housing 34 is detachably attached to the wrist 32 in a state facing the wrist. In the pressure chamber 44, a switching valve is provided from the electric pump 18.
A pressure fluid is supplied through 46, whereby the pulse wave sensor 42 is pressed against the body surface 36 into the pressure chamber 44 with a pressing force corresponding to the fluid pressure P. Therefore, in the present embodiment, the housing 3 of the pulse wave detection probe 33
4, the band 38, the diaphragm 40, and the like constitute a pressing means. The switching valve 46 is in a pressure supply state that allows supply of pressure into the pressure chamber 44 at a relatively slow constant speed.
The state can be switched between a pressure maintaining state in which the pressure of the pressure chamber 44 is maintained and an exhaust pressure state in which the pressure in the pressure chamber 44 is exhausted. A pressure sensor is provided between the switching valve 46 and the pressure chamber 44.
A pressure sensor 46 detects a fluid pressure P in the pressure chamber 44 and outputs a pressure signal SP representing the fluid pressure P to the A / A.
Output to the CPU 24 via the D converter 49.

An inner wall near the open end of the housing 34 and a band
At positions respectively corresponding to both mounting portions 38, a pair of arc-shaped rubber bags 48 and 50 are fixed so as to be sandwiched between the pulse wave sensor 42 and the rubber bags 4 and 50, respectively.
A pressure fluid is supplied from the electric pump 18 into the 8, 50 via the switching valve 52. This switching valve 52 is
A state where the supply of pressure into the rubber bag 48 is allowed and the inside of the rubber bag 50 is exhausted, a state where the inside of the rubber bag 48 is exhausted and the supply of pressure to the inside of the rubber bag 50 is allowed, The state can be switched between the state where both the exhaust pressure is blocked and the state where both the rubber bags 48 and 50 are exhausted, and the pressure can be selectively supplied to the rubber bags 48 and 50. Thereby, the pulse wave sensor 42 is moved in a direction substantially orthogonal to the radial artery 54.

The pulse wave sensor 42 has a large number of pressure-sensitive elements 60 such as pressure-sensitive diodes arranged alternately in two rows on a pressing surface 58 of a semiconductor chip 56 such as single-crystal silicon. By being pressed against the body surface 36 of the wrist 32 so that the arrangement direction of the elements 60 is substantially orthogonal to the radial artery 54, a pressure vibration wave, that is, a pulse wave, generated from the radial artery 54 and transmitted to the body surface 36 is detected. Then, a pulse wave signal SM representing the pulse wave is output to the CPU 24 via the A / D converter 62. The spacing between the ends pressure sensitive element 60e ₁ and end pressure sensitive element 60e ₂ positioned at both ends keep the arrangement direction of the pressure sensitive element 60, set larger than the maximum outer diameter during the pressing of the radial artery 54 In addition, the intervals in the arrangement direction of the pressure-sensitive elements 60 are determined so that a plurality of pressure-sensitive elements 60 can be arranged on the radial artery 54.
In the present embodiment, the body surface 36 corresponds to the surface of a living body, and the radial artery 54 corresponds to an artery.

The CPU 24 adjusts the fluid pressure P in the pressure chamber 44 by controlling the switching valve 46 via a drive circuit (not shown) according to a program stored in advance, and is sampled in the process of increasing the pressure in the pressure chamber 44. Based on the pulse wave signal SM, the optimal pressure-sensitive element 60a is determined from among a number of pressure-sensitive elements 60, and the optimal fluid pressure HDP ^* is determined. The blood pressure value measured by the cuff 10 and the magnitude of the pulse wave signal SM are determined. The pulse wave represented by the actual pulse wave signal SM detected by the optimal pressure-sensitive element 60a at the optimal fluid pressure HDP ^* is determined from the relationship based on the maximum value and the minimum value. The values are sequentially determined, and the determined blood pressure values are sequentially displayed on the blood pressure display 64. Further, the CPU 24 sequentially obtains a change amount per predetermined time of the actual fluid pressure HDP, which is generated in synchronization with the pulse of the radial artery 54 and is set to the optimal fluid pressure HDP ^* , according to a program stored in advance. When the amount of change exceeds a predetermined value, it is detected that a relative movement has occurred between the pulse wave sensor 42 and the wrist 32, and the pulse wave detected until the movement is recovered. The blood pressure monitor based on the data is canceled, and when the movement is recovered, the blood pressure monitor is restarted from an appropriate operation as needed.

Next, the operation of the blood pressure monitoring device configured as described above will be described with reference to the flowcharts of FIGS. 5 (a) to 5 (d).

First, the cuff 10 to the upper arm 12, after each wearing the pulse wave detecting probe 33 to the wrist 32, when the power switch (not shown) is turned ON, is initially processed (not shown) execution flag F ₁ to F ₅ Are cleared, and step S1 is executed to determine whether a manual start switch (not shown) has been turned ON. If this determination is denied, the standby state is set.If the determination is affirmative, step S2 is executed, and the electric pump 18 is driven and the switching valve 46 is switched to the pressure supply state. The pressure increase is started, and the pulse wave sensor 42 starts pressing the body surface 36. Next, step S3 is executed to read the pulse wave signal SM and the pressure signal SP representing the fluid pressure P in the pressure chamber 44, respectively, and step S4 is executed to execute the pulse wave corresponding to one pulse wave. It is determined whether signal SM has been detected. If one beat has not been detected yet, steps S3 and S4 are repeatedly executed. If one beat has been detected, the subsequent step S5 is executed to set the fluid pressure P to a predetermined fluid pressure Pa ( For example, it is determined whether or not the pressure has reached about 250 mmHg). The determination in step S5 is initially denied, and after the motion detection routine in step S6 is executed, steps S2 and subsequent steps are repeatedly executed.

This motion detection routine determines whether a relative movement (hereinafter simply referred to as “motion”) has occurred between the wrist 32 and the pulse wave sensor 42 due to the body movement of the subject during the rate-reducing pressurization in the pressure chamber 44. As shown in FIG. 6, first, at step SS1, the fluid represented by the pressure signal SP corresponding to one pulse wave detected at step S3 is executed. The maximum value _Pmax and the minimum value _{Pmin of the} pressure P are respectively determined, and step SS2 is executed to subtract the minimum value _Pmin from the maximum value _Pmax, thereby obtaining a fluid pressure fluctuating in synchronization with the pulse. The amplitude PA for one pulse wave of P is calculated. In the next step SS3, the content of the flag F ₁ is whether or not "1" is determined. "1" when the flag F ₁ is that motion has occurred
If it has not yet occurred, the following step SS4 is executed. In this step SS4, it is determined whether or not the one beat detected in the step S4 is the first one beat. If it is the first one beat, the steps S3 and subsequent steps are executed. If a beat subsequent to step SS5 is performed, the difference PA _diff between the amplitude PA ₂ is calculated this time and amplitude PA ₁ calculated the last time is calculated in step SS2. In the next step SS6, step SS5
It is determined whether or not the difference PA _diff obtained in is larger than a predetermined value PA _inahd . This value PA _inahd is a reference value for determining the occurrence of motion,
For example, initially set to a predetermined constant value, but a plurality of difference PAs in a state where no motion is detected
_{When diff} is found, the difference between the multiple PA _diffs is 2 of the average value.
The value is set to about three times. If the determination in step SS6 is denied, it is determined that no motion has occurred, and step S3 and subsequent steps are executed.If affirmative, it is determined that motion has occurred and the following steps
With the contents of the flag F ₁ in SS7 it is set to "1", and step SS8 is executed boosting the pressure chamber 44 is stopped. In the next step SS9, step S
The amplitude PA obtained this time in S2 is a predetermined value PA
_It is determined whether it is smaller than _outmot . This value PA _outmot
Is a reference value for determining the recovery of the motion, and is set to a predetermined constant value in an initial cycle for determining the optimal fluid pressure HDP ^{* and the} like.
In the subsequent cycle at the time of restart, the amplitude PA is set to a value which is about two to three times the amplitude PA obtained while the fluid pressure P in the pressure chamber 44 is in a substantially constant state (a state immediately before pressure increase). If the determination in step SS9 is denied, it is determined that the motion has not recovered, and the steps from step S3 are performed.At this time, since the determination in step SS3 is affirmed, step SS9 is performed following step SS3. You. Step SS
If the determination in step 9 is affirmative, the subsequent step SS10 is executed, so that the determination in step SS9 is, for example, 3
It is determined whether the result has been affirmed consecutively. Step SS
If the judgment of 10 is denied, it is determined that the motion has not yet recovered, and the steps S3 and subsequent steps are executed.If the result is affirmative, it is determined that the motion has recovered and the following step SS11 is performed. wherein together with the flag F ₁ is cleared, the step SS12 is executed, the pulse wave is loaded into the motion generating signals SM and pressure signal SP in
Are erased. Next, step SS13
Is executed, and the pressure increase in the pressure chamber 44 is restarted, and then the above-described step S3 and subsequent steps are executed.

When the fluid pressure P in the pressure chamber 44 reaches the fluid pressure Pa and the judgment in the step S5 is affirmed, the step S7 is executed, and the pulse read by the all pressure-sensitive elements 60 in the step S3 is executed. The maximum value (mV) and the minimum value (mV) of each pulse wave by the wave signal SM are obtained, and the amplitude of each pulse wave is obtained by calculating the difference between the maximum value and the minimum value. Next, step S8
Is performed, the maximum value of the amplitude of each pressure-sensitive element 60 is determined, and the pressure-sensitive element 60 that has detected the pulse wave of the maximum amplitude among the maximum values of the amplitudes has the optimal pressure-sensitive element. Determined as element 60a.

In the next step S9, it is determined whether or not the optimal pressure-sensitive element 60a determined in step S8 is located substantially at the center of the arrangement range of the pressure-sensitive elements 60. If this determination is denied, step S10 is executed in order to position the pulse wave sensor 42 in a direction substantially perpendicular to the radial artery 54, and the switching valve 46 is switched to the exhaust pressure state. After the internal pressure is exhausted, step S11 is executed. In step S11, in order to position the radial artery 54 at substantially the center of the arrangement range of the pulse wave sensor 42, the switching valve 52
Is supplied to the rubber bag 48 or the rubber bag 50 so that the pulse wave sensor 42 is driven in a direction substantially orthogonal to the radial artery 54. Then, after the pulse wave sensor 42 is driven in this way, Step S2 and subsequent steps are executed again.

If it is determined in step S9 that the optimal pressure-sensitive element 60a is located at substantially the center of the array range, step S12 is executed, and the pulse having the maximum amplitude is obtained by the optimal pressure-sensitive element 60a. fluid pressure P while being determined as an optimal fluid pressure HDP ^*, the switching valve 46 is pressure-maintaining state after the pressure chamber 44 is adjusted to its optimum fluid pressure HDP ^* in the pressure chamber 44 when the wave is detected And it is held at the optimum fluid pressure HDP ^* .

Next, step S13 is executed, and blood pressure measurement is performed by a so-called oscillometric method. That is, after switching the switching valve 16 to the pressure supply state to increase the cuff pressure to a pressure higher than the expected maximum blood pressure value of the subject (for example, a pressure of about 180 mmHg), the electric pump 18 is stopped and the switching valve 16 is turned off. By switching to the deceleration exhaust pressure state and slowly lowering the cuff pressure, the systolic blood pressure value H (mmHg) and the minimum blood pressure value H (mmHg) are determined based on the change in the magnitude of the fluctuation component of the cuff pressure signal SK detected in the pressure-decrease process. The blood pressure value L (mmHg) is determined. When the blood pressure value is determined in this manner, the switching valve 16 is switched to the rapid pressure release state, and the pressure in the cuff 10 is rapidly discharged.

Next, by executing step S14, from the maximum value M _max-a ^* and the minimum value M _min-a ^{* of the} actual pulse wave detected by the optimal pressure-sensitive element 60a at the optimal fluid pressure HDP ^* ,
For determining the blood pressure value P _B, such as systolic blood pressure values SYS and diastolic blood pressure DIA, the relational expression showing the relationship between the size M of the blood pressure value P _B and the pulse wave signal SM (1) is the following formula (2) And (3). That is, the systolic blood pressure value H and the diastolic blood pressure value L measured by the cuff 10 and the highest value at the optimum fluid pressure HDP ^* by the optimum pressure sensing element 60a among the highest value and the lowest value obtained at step S7. M _max-a ^* and minimum value M
_{Based on min-a} ^* , constants a and b in equation (1) are determined.

P _B = a · M + b (1) H = a · M _max-a ^* + b (2) L = a · M _min-a ^* + b (3) In this way, blood pressure and pulse wave After the relationship is determined,
Step S15 is executed, with the optimum pressure sensing element 60a and the end portion pressure-sensitive elements 60e ₁ located at both ends of the array range, 60e ₂ from the pulse wave signal SM are read respectively, the pressure chamber 44
The pressure signal SP, which represents the actual fluid pressure HDP in, is read. In the following step S16, it is determined whether or not the pulse wave signal SM corresponding to one pulse wave is detected together with the pressure signal SP. If this determination is denied, step S17 is performed.
Is executed to determine the actual fluid pressure HDP and the optimal fluid pressure HDP ^*.
After the difference H _e is calculated with, step S18 is executed.
In this step S18, the content of the flag F ₂ is "0"
Is determined. The flag F ₂ is the pulse wave sensor
This indicates whether or not a motion has occurred during the blood pressure monitoring by 42. When the content is “1”, it indicates that the motion has occurred. If no motion has yet occurred, step S19 is executed, and
For example whether the difference between H _e corresponding to 3 beats is calculated it is determined. This decision is initially denied, so step
Steps S15 to S19 are repeatedly executed. Step S1
Step S1 is performed while steps 5 to S19 are repeatedly executed.
If the determination in step 6 is affirmative, step S20 is executed and 1
Maximum H _emax and minimum value H of the difference H _e corresponding to the beats
with _emin respectively, are determined, step S21 is run, by subtracting the minimum value H _emin from its maximum value H _emax, the variation amount of the difference H _e corresponding to one beat H _ever
(Change amount of fluid pressure HDP per beat) is obtained.
Therefore, in the present embodiment, the steps S17, S20, and S21 correspond to the fluid pressure change amount calculating means.

Next, step S22 is executed, the contents of the flag F ₂ is whether a "1" is determined. If the motion has not yet occurred and the determination in step S22 is denied, the following step S23 is executed, and the variation amount _Ever obtained in step S20 is set to a predetermined value _Hinmot.
It is determined whether it is greater than. This value H _Inmot is a reference value serving to determine the occurrence of motion, initially is set to a constant value set in advance, a plurality of variation amounts H _ever in a state in which the motion is not detected When it is obtained, it is set to a value that is about two to three times the average value of the plurality of variation amounts _Have . Therefore, in the present embodiment, the above step S23 corresponds to the motion detecting means. If the determination in step S23 is denied, it is determined that no motion has occurred, and step S24 is executed, whereby the maximum value of one pulse wave detected by the optimal pressure-sensitive element 60a in step S15 M _max-a ^* and minimum value
M _min-a ^* and the minimum value M _min-e1 ^* and the minimum value M _min-e2 ^{* of} one pulse wave detected by the end pressure sensing elements 60e ₁ and 60e ₂ are determined, respectively. Next, by executing step S25, the maximum value _Mmax-a ^{* of the} optimal pressure-sensitive element 60a is obtained ^.
The systolic blood pressure value SYS and the diastolic blood pressure value DIA are determined from the relationship obtained in step S14 based on the minimum value M _min-a ^* and similarly, the end pressure sensing element 60
the lowest value by _{e 1, 60e 2 M min-} e1 *, the minimum value M _min-e2 ^* diastolic blood pressure value DIA _e1 be based on pressure, diastolic blood pressure DIA _e2 is determined, the systolic blood pressure value by the optimum pressure-sensitive element 60a SYS And the diastolic blood pressure value DIA is displayed on the blood pressure display 64. Continue, step S
In 26, the content of the flag F ₃ is whether or not "1" is determined. The flag F _3, there is shown whether the judgment of a motion detected in step S23 is restored has been made, the determination that the motion is restored when the content is "1" Indicates that this has been done. Yet if the motion does not occur, even made is to not not the content of the flag F ₃ decision of the motion has been restored is "0"
Therefore, the determination in step S26 is denied, and the
27 is executed. In this step S27, the flag F
It is determined whether the content of ₅ is “1”. The flag F _5, there is shown whether the determination in step S49 in which are executed after the motion recovery is negative, the determination in step S49 is negative when the content is "1" Is shown. If not yet motion occurs, because the content of the flag F ₅ is "0", the determination in step S27 is repeatedly executed is negative step S15 follows, the blood pressure monitor is continued.

If the determination in step S19 is affirmative, step S28
There is running, the mean value H _eav of the difference H _e corresponding to 3 beats
Is calculated, and step S29 is executed to determine whether or not the absolute value of the average value _Heav is larger than a predetermined constant value α. If this determination is denied, steps S15 and subsequent steps are executed.If the determination of step S29 is affirmed, step S30 is executed and the actual fluid pressure HDP in the pressure chamber 44 is controlled by feedback control. After the adjustment to the optimum fluid pressure HDP ^* , Step S15 and subsequent steps are executed.

If the determination in step S23 is affirmative and a motion is detected, step S31 is executed, and the flag F ₂
Is set to "1" indicating that a motion has occurred. Next, by executing step S32, it is determined whether or not the variation amount _Ever obtained in step S21 is smaller than a predetermined value _Houtmot . This value H
_outmot is a value serving as a reference for judging the recovery of the motion. For example, although initially set to a predetermined constant value, the value H used in step S23 is
_{After inmot} is set from a predetermined constant value to a predetermined value, it is set to a value that is about half of the value _Hinmot . If the motion has not yet recovered and the determination in step S32 is denied, step S15 and subsequent steps are executed. At this time, step S33 is executed following step S18, and it is determined whether or not a predetermined period of time has elapsed after the occurrence of the motion without recovering the motion.If the predetermined period of time has elapsed, step S34 is executed. are but a flag F ₂ is the step S30 step S15 after being adjusted to have been executed optimum fluid pressure HDP ^* less while being cleared is performed, the fluid pressure HDP when not yet elapsed predetermined time Step S without performing feedback control
While step 15 and subsequent steps are executed, step S32 is executed following step S22, whereby the blood pressure monitor based on the pulse wave data detected during the motion is canceled.

If the determination in step S32 is affirmative, step S35 is reached.
Is executed, and it is determined whether or not the determination in step S32 has been consecutively affirmed, for example, three times. If the determination in step S35 is negative, step S15 is less repeatedly executed, the feedback control and blood pressure monitor of the fluid pressure HDP for the content of the flag F ₂ In this case remains "1" is canceled . If the determination in step S35 is affirmative, it is determined that the motion has recovered, and the subsequent step S36 is executed. In step S36, with the content of the flag F ₃ is set to "1" indicating that the determination that the motion is restored has been made, the flag F ₂ is cleared, then step S15 follows is executed. At this time, the determination in step S18 is denied, and a step for feedback control of the fluid pressure HDP is performed.On the other hand, the determination in step S22 is denied, and step S23 is executed following step S22. If it is determined that no motion has occurred, the step
After S24 and step S25 are executed to monitor the blood pressure, step S26 is executed. At this time, step S26
Is affirmative, step S37 is executed.

In step S37, it is determined whether a pulse wave signal SM corresponding to, for example, three beats has been detected since the motion was recovered. While still the step S15 or less if not detected 3 beats are performed, if it is detected third beat, the step S38 is the step S39 after the execution flag F ₃ is cleared executed. In step S39, a slope c corresponding to the slope a in the relational expression (1) determined in step S14 is calculated according to the following equation (4).

However, Sba: average value of three beats of systolic blood pressure value SYS before motion occurrence Dba: average value of three beats of diastolic blood pressure value DIA before motion occurrence Sft: maximum value M _max-a ^* after motion recovery average of 3 beats DFT: the average value of the minimum value after motion recovery M _min-a ^* of 3 beats Next, by step S40 is executed, the contents of the flag F ₅ is "1" Is determined. Determination of the flag F content of ₅ is "1" if it is not the step S40 is denied at step S50 to be described later, followed by step S41 is executed. In this step S41,
For example, an average Sba of three beats of the systolic blood pressure value SYS before the occurrence of the motion and a systolic blood pressure value SYS of three beats after the motion recovery.
The absolute value of the difference between the average value Sfa for beats is, for example, 5 mmHg or less, and the average value Dba for three beats of the diastolic blood pressure value DIA before the occurrence of the motion and the diastolic blood pressure value DIA after the motion recovery, for example, 3 The absolute value of the difference from the average value for beats is, for example, 5
It is determined whether it is equal to or less than mmHg. If this determination is affirmed, steps S15 and subsequent steps are executed to continue the blood pressure monitoring, while if denied, the subsequent step S4
2 is executed. In this step S42, it is determined whether the variation Sbv of the systolic blood pressure value SYS before the occurrence of the motion, for example, for three beats, exceeds 12 mmHg, for example, or the variation Dbv of the diastolic blood pressure value DIA, for example, for the three beats before the occurrence of the motion. For example, it is determined whether it exceeds 12 mmHg.
If this determination is affirmative, after the step S43 is executed contents of Fukugu F ₄ is "1", step S13
Is executed to perform the blood pressure measurement by the cuff 10 again, and step S14 is executed to update the relational expression (1) based on the newly measured systolic blood pressure value H and diastolic blood pressure value L. On the other hand, if the determination in step S42 is denied, step S44 is executed, whereby the average value Bb ₁ of, for example, three beats of the diastolic blood pressure value DIA _e1 by the end pressure sensing element 60e ₁ before the occurrence of the motion. and whether the absolute value of the difference between the average value Bf ₁ of 3 beats of diastolic blood pressure DIA _e1 by end pressure-sensitive element 60e ₁ after motion recovery is for example 30mmHg or less, or motion generation front end Pressure sensitive element
Average value B of the diastolic blood pressure value DIA _e2 based on 60e ₂ for three beats
whether the absolute value of the difference between b ₂ and the average value Bf ₂ of example 3 beats diastolic blood pressure DIA _e2 by end pressure-sensitive element 60e ₂ after the motion recovery is less than for example 30mmHg is determined. If this determination is affirmed, the blood pressure monitoring is continued by assuming that the blood pressure has actually fluctuated, and step S15 and subsequent steps are executed.
There is running, the contents of the flag F ₄ is whether or not "1" is determined. If the determination is affirmative and the relational expression (1) is updated based on the blood pressure value re-measured by the cuff 10, the following step S46 is executed, and the slope calculated this time in step S39 is executed. c is equal to or greater than or equal to 1.5 times the slope c ₁ calculated in step S39 immediately after the update equation based on the blood pressure value (1) is performed by the cuff 10 is determined. If the determination of step S46 is YES, step S47 is executed the flag F ₄ and the flag F ₅
Are cleared, and after step S48 is executed and the pressure in the pressure chamber 44 is exhausted, steps S2 and subsequent steps are executed to determine the optimal pressure-sensitive element 60a and the optimal fluid pressure HDP ^*. Will be restarted from On the other hand, if the determination in step S46 is negative, step S49 is executed, and it is determined whether the determination in step S46 has been consecutively negative three times, for example. If the determination of step S49 is negative, after the step S50 is executed the contents of the flag F ₅ is set to the "1", step S15 follows is executed. At this time, since the determination in step S27 is affirmative, step S39 is executed following step S27 to calculate the slope c,
Since the determination in step S40 following S39 is also affirmative, step S46 is executed following step S40. If the determination of step S49 is positive, with a flag F ₅ is cleared step S51 is executed, step
By executing S52, the relational expression (1) is updated in accordance with the following expression (5) using the slope c (calculated based on the blood pressure value before the occurrence of the motion) calculated this time in step S39. Then, steps S15 and subsequent steps are executed, and the blood pressure monitor is continued.

P _B = c · M + (Sba−c · Sft) (5) According to the present embodiment, the pressure in the pressure chamber 44 is set to the optimum fluid pressure HDP ^* , and the blood pressure monitor based on the pulse wave signal SM is obtained. Is started, the variation _Hever corresponding to the variation per one pulse of the actual fluid pressure HDP generated in synchronization with the pulse is sequentially calculated, and the variation _Hever is a predetermined value. Since it is configured to detect that a motion has occurred when H _inmot has been exceeded, and configured to cancel the blood pressure monitor based on the pulse wave data detected until the motion is restored, step
Even if the fluid pressure HDP feedback control performed based on the determination in S29 cannot cope with the motion, the blood pressure monitor can be suitably performed based on the suitable pulse wave after the motion recovery.

Further, according to the present embodiment, when a certain period of time has elapsed without recovery after the occurrence of the motion, the fluid pressure HDP is adjusted to the optimal fluid pressure HDP ^* , and the blood pressure monitor is continued, so that the blood pressure monitor is continued. Therefore, it is possible to prevent the blood pressure monitor from being interrupted for a long time without recovering the motion.

Further, according to the present embodiment, in steps S41 and S42, the change in the systolic blood pressure value or the diastolic blood pressure value before and after the motion recovery is relatively large and the systolic blood pressure value before the motion occurrence or If the variation of the diastolic blood pressure value is relatively large, the blood pressure is measured by the cuff 10 and the system is configured to restart from the step of obtaining the relationship between the measured blood pressure and the leg wave. In S42, and in step S44, even if the change in systolic blood pressure value or diastolic blood pressure value before and after motion recovery is relatively large, the variation in systolic blood pressure value and diastolic blood pressure value before motion occurrence is relatively small, The diastolic blood pressure value by the edge pressure-sensitive element before and after motion recovery Is relatively large, the relational expression between the blood pressure and the pulse wave is updated using the slope c obtained based on the blood pressure value before the motion occurs, and the like. as when the inclination c is much greater than the slope c ₁ calculated immediately after the Updater based on measured blood pressure cuff 10 after motion recovery, configured to restart from the point of determining the optimum fluid pressure HDP ^* etc. Therefore, the reliability of the blood pressure value monitored after the recovery of the motion generated during the blood pressure monitoring is further improved.

Further, according to the present embodiment, it is determined whether or not motion has occurred even when the pressure in the pressure chamber 44 is being increased in order to determine the optimal fluid pressure HDP ^* and the optimal pressure-sensitive element 60a, and the motion has occurred. In this case, the boosting is stopped until the motion is recovered, and the optimal fluid pressure HDP ^* and the optimal pressure-sensitive element 60a are determined based on the data excluding the pulse wave data and the pressure data during the motion. , The optimal fluid pressure HDP ^* and the optimal pressure-sensitive element 60a can be determined more reliably, and it is not necessary to increase the pressure in the pressure chamber 44 every time a motion occurs. In this case, the motion detection during the pressure increase is not based on whether the amount of change in fluid pressure per beat exceeds a predetermined value as in blood pressure monitoring, but on the change in fluid pressure per beat this time. This is performed based on whether the difference between the volume and the previous change amount per beat exceeds a predetermined value, and therefore, the influence on the change amount per beat of the fluid pressure due to continuous pressure increase. Can be offset.

Incidentally, in the illustrated embodiment, the motion of the actual fluid pressure in the blood pressure monitor based on whether the variation amount H _ever the corresponding exceeds the value H _Inmot predetermined for the amount of change per one beat of the HDP of Although the detection is performed, it is not always necessary. For example, the motion can be detected based on whether or not the change amount of the fluid pressure HDP per several beats exceeds a predetermined value.

Further, in the above-mentioned embodiment, the fluid pressure change amount calculating means and the motion detecting means are respectively constituted by the software by the microcomputer, but these means can be constituted by a hard logic circuit having the same function. is there.

In the above-described embodiment, when the pressure in the pressure chamber 44 is continuously changed to determine the optimum fluid pressure HDP ^{* and the} like, the maximum value of the fluid pressure P in the pressure chamber 44 per beat is obtained. Motion is detected based on whether or not the difference PA _diff between the previous and current amplitude PA obtained from P _max and the minimum value P _min has exceeded a predetermined value. Almost like the case of motion detection during
Detecting a motion on the basis of the actual whether the difference between the previous and current variation quantity H _ever per beat difference H _e of the fluid pressure HDP and optimum fluid pressure HDP ^* exceeds a predetermined value It can also be configured as follows. In this case, as the optimum fluid pressure HDP ^* , for example, the fluid pressure determined at the previous blood pressure monitoring is used.

Further, in the above-described embodiment, the pulse wave sensor 42 includes a large number of pressure-sensitive elements 60, but may include one pressure-sensitive element.

In the above-described embodiment, the case where the pulse wave is detected from the radial artery 54 has been described. However, the pulse wave may be detected from the dorsal foot artery or the like.

Further, in the above-described embodiment, the blood pressure monitoring device including the pulse wave detecting device of the present invention has been described. However, it is needless to say that the pulse wave itself may be monitored.

In addition, the present invention can be variously modified without departing from the spirit thereof.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims. FIG. 2 is a block diagram showing a configuration of a blood pressure monitoring device provided with a pulse wave detection device as an example of the present invention. FIG. 3 is a view showing a mounted state of a probe for detecting a pulse wave in the blood pressure monitoring device of FIG. FIG. 4 is a view of the pulse wave detection probe of FIG. 3 viewed from the wrist side. Fifth
(A) to (d) are flowcharts for explaining the operation of the blood pressure monitoring device in FIG. FIG. 6 is a flowchart showing a motion detection routine in FIG. 5 (a). ｛34: housing, 38: band, 40: diaphragm｝ (pressing means) 36: body surface (body surface) 42: pulse wave sensor 54: radial artery (artery) Step S17, 20, 21: (fluid pressure change amount Calculation means) Step S23: (Motion detection means)

Claims (1)

(57) [Claims] 1. A pulse wave sensor comprising: a pulse wave sensor; and a pressing means for pressing the pulse wave sensor onto an artery on the surface of a living body with a fluid pressure. A pulse wave detection device of a type for sequentially detecting a pulse wave generated from the artery by a wave sensor, wherein the pulse wave is generated in synchronization with a pulse after the fluid pressure of the pressing means is set to the optimal fluid pressure. A fluid pressure change amount calculating means for sequentially calculating a change amount per predetermined time of the fluid pressure, and when the fluid pressure change amount calculated by the fluid pressure change amount calculating means exceeds a predetermined value, A pulse wave detection device, comprising: a motion detection unit that detects that a relative motion has occurred between the pulse wave sensor and the living body.