JP3027751B1 - Lower limb upper limb blood pressure index measurement device - Google Patents

Abstract

【wrap up】 [Purpose] To accurately measure the lower limb upper limb blood pressure index.
The present invention provides a lower limb and upper limb blood pressure index measuring device capable of performing the following. SOLUTION: Second cuff pressure control means 76 (SB1 to SB1)
B3), the cuff pressure P _C1Is pre-set during the slow pressure reduction process.
Determined predicted lower extremity systolic pressure EBP_LSYSAnd when
Cuff pressure P_C2Is a predetermined prediction in the slow pressure drop process
Upper limb systolic pressure EBP_USYSTime
And cuff pressure P_C1And cuff pressure P_C2Is controlled and its cuff
Pressure P_C1And cuff pressure P_C2In the control process, the ankle blood pressure measurement
Ankle systolic pressure BP by setting 16_LSYSIs measured and brachial blood
The upper arm systolic pressure BP by the pressure measuring device 18_USYSIs measured
You. Then, the ankle and upper arm blood pressure index calculating means 82 (SB8)
, The ankle systolic pressure BP_LSYSAnd upper arm systolic pressure BP
_USYSABI is calculated based on
High ABI can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a lower limb upper limb blood pressure index for measuring a lower limb upper limb blood pressure index (a ratio of a blood pressure value in the upper limb to a blood pressure value in the lower limb or a ratio of a blood pressure value in the lower limb to a blood pressure value in the upper limb). It relates to a measuring device.

[0002]

2. Description of the Related Art When there is an arterial occlusion disease or arterial stenosis, the lower limb blood pressure value of a living body is calculated from the upper limb blood pressure value corresponding to the lower limb blood pressure value (for example, upper limb systolic pressure corresponds to lower limb systolic pressure). Will also be lower. Conversely, if the lower limb blood pressure value is higher than the upper limb blood pressure value by a predetermined value or more, there is a possibility of aortic regurgitation or aortic syndrome limited to the aortic arch. Utilizing this, based on the ratio between the lower limb blood pressure value and the upper limb blood pressure value,
Evaluating arterial disease has been performed.

[0003] The lower limb upper limb blood pressure index is calculated by using an ankle as a lower limb,
Using the upper arm as the upper limb, ie, the Ankle Brachial Index = ABI; or
AnKle / Arm Blood Pressure Index = Also called AAI or API. ) Is used and is generally calculated by dividing the systolic pressure at the ankle by the systolic pressure at the upper arm. The diagnosis based on the ankle-brachial blood pressure index calculated as described above is performed based on whether or not the ankle-brachial blood pressure index is equal to or less than a predetermined value set to, for example, about 0.9. Therefore, a slight change in the lower limb blood pressure value and the upper limb blood pressure value greatly affects the diagnosis result.

[0004]

On the other hand, the blood pressure of a living body changes even in a short time. For example, even at rest, there may be a change of 20 mmHg or more in 10 seconds due to a physiological change. Therefore, if there is a time difference between the time when the lower limb blood pressure value is determined and the time when the upper limb blood pressure value is determined, the blood pressure value of the living body may have changed during that time. Therefore, in the conventional device, even if there is a difference between the lower limb blood pressure value and the upper limb blood pressure value, it is determined whether the difference is due to a change in the blood pressure value of the whole living body or a difference in the measurement site. The lower limb upper limb blood pressure index calculated based on the lower limb blood pressure value and the upper limb blood pressure value could not be determined, and the accuracy was insufficient.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a lower limb upper limb blood pressure index measuring device capable of measuring a lower limb upper limb blood pressure index with high accuracy. It is in.

[0006]

Means for Solving the Problems As a result of repeated studies to solve the above problems, the present inventors have found that the time when the blood pressure value is determined in the lower limb coincides with the time when the blood pressure value is determined in the upper limb. Then, it was found that the difference between the lower limb blood pressure value and the upper limb blood pressure value can be determined to be due only to the difference in the measurement site. The present invention has been made based on such findings.

That is, the gist of the present invention is as follows.
A lower limb blood pressure measurement device that measures a lower limb blood pressure value in the lower limb based on a pulse wave sequentially obtained in a slowly changing process of the compression pressure of the lower limb cuff wound on the lower limb of the living body, and a wrap around the upper limb of the living body A lower limb upper limb blood pressure index measuring device comprising: an upper limb blood pressure measuring device that determines an upper limb blood pressure value in the upper limb based on a pulse wave sequentially obtained in a slowly changing process of the compression pressure of the rotated upper limb cuff; (A) when the cuff pressure of the lower limb cuff becomes a predicted lower limb blood pressure value determined in advance as the predicted value of the lower limb blood pressure value in the slowly changing process, and the cuff pressure of the upper limb cuff is gradually reduced. In the rapid change process, the cuff pressure of the lower limb cuff and the cuff pressure of the upper limb cuff are controlled such that the predicted upper limb blood pressure value becomes a predicted upper limb blood pressure value as the predicted value of the upper limb blood pressure value. 2 cuff suppression And (b) a lower limb blood pressure value measured by the lower limb blood pressure measurement device while the second cuff pressure control means controls the compression pressure of the lower limb cuff and the compression pressure of the upper limb cuff. A lower limb upper limb blood pressure index calculating means for calculating a lower limb upper limb blood pressure index based on the upper limb blood pressure value measured by the upper limb blood pressure measurement device.

[0008]

In this manner, the second cuff pressure control means controls the timing at which the cuff pressure of the cuff for the lower limb reaches a predetermined predicted lower limb blood pressure value in the slow down process, and the cuff pressure of the cuff for the upper limb. The cuff pressure of the cuff for the lower limb and the cuff pressure of the cuff for the upper limb are controlled so that the time at which the predetermined upper limb blood pressure value becomes the predetermined upper limb blood pressure value in the slow pressure lowering process is controlled. In the process of controlling the cuff pressure of the cuff, the lower limb blood pressure measurement device measures the lower limb blood pressure value, and the upper limb blood pressure measurement device measures the upper limb blood pressure value. Then, since the lower limb upper limb blood pressure index calculating means calculates the lower limb upper limb blood pressure index based on the lower limb blood pressure value and the upper limb blood pressure value, a highly accurate lower limb upper limb blood pressure index can be obtained.

[0009]

In another preferred embodiment of the present invention, preferably, the lower limb upper limb blood pressure index measuring device includes: (c) the lower limb blood pressure measuring device performs the lower limb blood pressure index measurement before calculating the lower limb upper limb blood pressure index. Measuring the lower limb blood pressure value of the living body, a predicted lower limb blood pressure value determining means for determining the lower limb blood pressure value to the predicted lower limb blood pressure value, and (d) prior to the upper limb blood pressure measurement for calculating the lower limb upper limb blood pressure index, Predicted upper limb blood pressure value determination means for measuring the upper limb blood pressure value of the living body by the upper limb blood pressure measurement device, and determining the upper limb blood pressure value as the predicted upper limb blood pressure value.
In addition. In this way, the lower limb blood pressure value actually measured for the living body before the lower limb upper limb blood pressure index is calculated is determined by the predicted lower limb blood pressure value determining means as the predicted lower limb blood pressure value. By the calculation of the lower limb blood pressure index, since the actually measured upper limb blood pressure value for the living body is determined as the predicted upper limb blood pressure value before the lower limb blood pressure index is calculated, Since the time when the value is determined and the time when the upper limb blood pressure value is determined can be accurately matched, a more accurate lower limb upper limb blood pressure index can be obtained.

Preferably, the lower limb upper limb blood pressure index measuring device further comprises: (e) a cuff pressure of the lower limb cuff for measuring the lower limb blood pressure value by the predicted lower limb blood pressure value determining means;
The apparatus further includes first cuff pressure control means for controlling a cuff pressure of the upper limb cuff for measuring the upper limb blood pressure value by the predicted upper limb blood pressure value determining means using a common value. According to this configuration, since the first cuff pressure control means controls the cuff pressure of the lower limb cuff and the cuff pressure of the upper limb cuff to have a common value, the predicted lower limb blood pressure value and the predicted upper limb blood pressure value Are determined relatively close. Therefore,
Since the influence of the blood pressure fluctuation based on the time difference included in the difference between the predicted lower limb blood pressure value and the predicted upper limb blood pressure value can be reduced, the time when the lower limb blood pressure value is determined and the time when the upper limb blood pressure value is determined are further increased. Accurate matching can be achieved.

[0011]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a block diagram illustrating a configuration of an ankle-brachial index device 10 to which the present invention is applied. That is, in the ankle-brachial index, the ankle 12 is selected as the lower limb,
This is a lower limb upper limb blood pressure index measuring device in which the upper arm 14 is selected as the upper limb. It should be noted that this ankle-brachial index 10
Is measured in a prone position, a lateral position, or a lateral position so that the upper arm and the ankle are substantially at the same height.

In FIG. 1, an ankle-brachial blood pressure index measuring device 10 measures a blood pressure at an ankle 12 (for example, a right ankle), and measures a blood pressure at an ankle blood pressure measuring device 16 functioning as a lower limb blood pressure measuring device and a blood pressure at an upper arm 14. And an upper arm blood pressure measuring device 18 functioning as an upper limb blood pressure measuring device.

The ankle blood pressure measuring device 16 includes a cuff 20 wound around a patient's ankle 12 with a rubber bag in a cloth band-shaped bag.
And a pressure sensor 24, a switching valve 26, and an air pump 32 connected to the cuff 20 via a pipe 22.
And This switching valve 26 is in a pressure supply state that allows the supply of pressure into the cuff 20, a gradual exhaust pressure state in which the opening of the electric valve is controlled to gradually exhaust the cuff 20 at an arbitrary speed, It is configured to be able to be switched to three states of a rapid exhaust state in which the inside of the cuff 20 is quickly exhausted.

The pressure sensor 24 detects the pressure in the cuff 20.
Pressure signal SP ₁The static pressure discrimination circuit
0 and the pulse wave discrimination circuit 32, respectively. Static pressure valve
Another circuit 30 includes a low-pass filter, and the pressure signal SP₁
Pressure, ie, cuff pressure P_C1Cuff representing
Pressure signal SK₁And the cuff pressure signal SK₁A / D
The electric power is supplied to the electronic control device 36 via the converter 34.

The pulse wave discriminating circuit 32 includes a band pass filter, and a pulse wave signal S which is a vibration component of the pressure signal SP _1.
The pulse wave signal SM ₁ to discriminate the M ₁ in frequency A / D
The electric power is supplied to the electronic control unit 36 via the converter 38.

The upper arm blood pressure measuring device 18 is used for measuring the ankle blood pressure.
Cuff having the same configuration as that provided in the setting device 16.
40, piping 42, pressure sensor 44, and switching valve 46
The cuff 40 is wound around the upper arm 14, and the switching valve 46 is
It is connected to the air pump 32. And the pressure cell
The sensor 44 has a pressure signal SP representing the pressure in the cuff 40.
_TwoIs the same as that provided in the ankle blood pressure measurement device 16.
Static pressure discriminating circuit 48 and pulse wave discriminating circuit having one configuration
50 respectively. The static pressure discriminating circuit 48 is a pressure signal
SP_TwoPressure, ie, cuff pressure P_C2The table
Cuff pressure signal SK_TwoAnd the cuff pressure signal SK_TwoTo
Supply to the electronic control unit 36 via the A / D converter 52,
The pulse wave discrimination circuit 50 outputs the pressure signal SP_TwoIs the vibration component of
Pulse wave signal SM _TwoOf the pulse wave signal SM
_TwoIs supplied to the electronic control unit 36 via the A / D converter 54.
I do.

The electronic control unit 36 includes a CPU 56, R
It is constituted by a so-called microcomputer having an OM 58, a RAM 60, an I / O port (not shown), and the like. The CPU 56 executes signal processing while utilizing the storage function of the RAM 60 according to a program stored in the ROM 58 in advance. , Output a drive signal from the I / O port to control the air pump 28 and the two switching valves 26 and 46, and to control the display contents of the display 62.

FIG. 2 is a functional block diagram for explaining a main part of the control function of the electronic control unit 36. As shown in FIG. The first cuff pressure control means 70 includes a second lower limb blood pressure value determination means 78 described later.
Prior to the determination of the lower limb blood pressure value by the first and second upper limb blood pressure value determining means 80, the air pump 2
And controls the 8 and two switching valves 26, 46, synchronously with the cuff pressure P _C1 - P _C2 of the two cuffs 20, 40 with a common value, that is, the cuff pressure P _C1 and the cuff pressure P _C2 And change each one. For example, two switching valves 26
・ Switch 46 to the pressure supply state at the same time, and set the cuff pressure P _C1
・ P _C2 is set to a predetermined target pressure value P _CM (for example, 180 mmHg
It was quickly increased to the extent of the pressure value), then, by switching the two switching valve 26, 46 simultaneously Josoku buck state to slow decreasing the cuff pressure P _C1 - P _C2 at a rate of about 3 mmHg / sec.

The predicted lower limb blood pressure value determining means 72 includes a first cuff.
The cuff 20 wound around the ankle 12 by the pressure control means 70
Cuff pressure P_C1In the process of slowly changing
Pulse wave signal SM to be sampled₁Represents the anterior tibial artery and posterior
Changes in amplitude of tibial artery waves (hereinafter referred to as tibial artery waves)
Based on the oscillometric method
Ankle blood pressure value BP at neck 12_L(Ankle systolic pressure BP
_LSYS・ Ankle diastolic pressure BP _LDIAEtc.) and decide
Ankle blood pressure BP_LAny one of, preferably,
The ankle-brachial blood pressure index calculating means 82 described later
It is used to calculate the arm blood pressure index (hereinafter, referred to as ABI).
Blood pressure value BP of the same kind_LLower leg blood pressure EB
P_LTo be determined.

The predicted upper limb blood pressure value determining means 74 includes a first cuff.
The cuff 40 wound around the upper arm 14 by the pressure control means 70
Cuff pressure P_C2In the process of slowly changing
Pulse wave signal SM to be sampled_TwoChanges in the amplitude of the brachial artery wave
Based on the well-known oscillometric method
Upper arm blood pressure value BP at the upper arm 14_U(Upper arm systolic pressure BP
_USYS-Upper arm diastolic pressure BP_UDIAEtc.) and decide
Upper arm blood pressure BP_UAmong the above, the predicted blood pressure value determining means 7
2 predicted ankle blood pressure EBP_LDetermined ankle blood pressure
Value BP_LAnd the upper arm blood pressure value BP corresponding to_UPredict upper limb blood pressure
EBP_UTo be determined. For example, the predicted lower limb blood pressure
Ankle systolic pressure BP by value determination means 72 _LSYSIs predicted lower limb
Blood pressure value EBP_L, The upper arm systolic pressure BP
_USYSPredict the upper limb blood pressure EBP_UTo be determined.

The second cuff pressure control means 76 includes the air pump 2
8 and the switching valve 26, the cuff 20
Cuff pressure P_C1The predetermined target pressure lower than the diastolic blood pressure value
After rapidly increasing the pressure to a value, for example, to about 3 mmHg / sec
Slowly increase the pressure at the set predetermined speed, or
The pressure is rapidly increased until the specified target pressure higher than the pressure value is reached.
After that, a predetermined speed set at, for example, about 3 mmHg / sec.
Leg cuff pressure control means for slowly lowering pressure in degrees and an air pump
The cuff 40 is controlled by controlling the
Cuff pressure P inside_C2Is a predetermined target pressure lower than the diastolic blood pressure value.
After rapidly increasing the pressure to the force value, for example, about 3 mmHg / sec
Slowly increase the pressure at the specified speed set in
Increases pressure rapidly until the target pressure is higher than the blood pressure value
After that, a predetermined value set to, for example, about 3 mmHg / sec
Upper limb cuff pressure control means for gradually lowering pressure at a speed.
The cuff pressure P by the lower limb cuff pressure control means_C1Slow speed change
During the conversion process, the cuff pressure P_C1Is the predicted lower limb blood pressure value determination
Predicted lower limb blood pressure value EBP determined by means 72_LTona
And the cuff pressure P by the upper limb cuff pressure control means. _C2of
During the slow change process, the cuff pressure P_C2Is the predicted upper limb
Predicted upper limb blood pressure value E determined by blood pressure value determining means 74
BP_UThe switching valve 26 and the
And a cuff pressure adjusting means for controlling the cuff pressure. This mosquito
Control of the switching valves 26 and 46 by the pressure adjusting means.
Cuff pressure P_C1And P_C2The control of
If the pressure is increasing, it is necessary to reduce
Also means adjusting one side, and the slow speed change is
In some cases, step-down start time, step-down start pressure, step-down speed
Means to adjust at least one of

[0022] Figures 3 and 4, in the second cuff-pressure changing means 76, an example of control of the cuff pressure P _C1 and P _C2 by the control of the switching valve 26 and 46, both predicted lower limb BP value EBP _L Leg systolic pressure predicted as EBP _LSYS
Is used, and the predicted upper limb systolic pressure EBP _USYS is used as the predicted upper limb blood pressure value EBP _U. FIG.
One of the boost speed-step-down start pressure, antihypertensive speed of the cuff pressure P _{C1-P C2} is equal, the boosting start timing (i.e., in this case, the step-down start timing) is adjusted. Figure 4 is a step-up start timing and rate of rise-buck start timing of the two cuff pressures P _C1, P _{C2,
Equalize the} rate of pressure reduction, adjust the onset pressure to lower the lower extremity systolic pressure EBP _LSYS or the lower extremity systolic pressure EBP _USYS
And a predetermined value α previously determined based on an experiment.

The second lower limb blood pressure value determining means 78 generates the tibial artery wave represented by the pulse wave signal SM ₁ which is sequentially sampled by the second cuff pressure controlling means 76 while the cuff pressure P _C1 is gradually changed. Ankle blood pressure value BP _{L at} ankle 12 using well-known oscillometric method based on changes in amplitude
That is, ankle systolic pressure BP _LSYS / ankle diastolic pressure BP _{LD IA}
Etc. are determined. The second upper limb blood pressure value determining means 80 controls the change in the amplitude of the brachial artery wave represented by the pulse wave signal SM ₂ sequentially acquired in the process in which the cuff pressure PC ₂ is gradually changed by the second cuff pressure controlling means 76. Arm blood pressure value BP at the upper arm 14 using a well-known oscillometric method based on
_U, upper arm systolic pressure BP _USYS , upper arm diastolic pressure BP
_{Determine UDIA,} etc.

The ankle and upper arm blood pressure index calculating means 82 calculates the ankle blood pressure value BP determined by the second lower limb blood pressure value determining means 78.
And _L, based on the upper arm blood pressure BP _U determined by the second limb blood-pressure determining means 80 calculates the ABI, is displayed on the display 62 and the calculated ABI.

FIGS. 5 and 6 show the electronic control unit 36.
It is a flowchart for explaining the main part of the control operation of,
FIG. 5 shows a first blood pressure measurement routine, and FIG. 6 shows a second blood pressure measurement routine. In FIG. 5, first, steps SA1 to SA3 (hereinafter, the steps are omitted) corresponding to the first cuff pressure control means 70 are executed. In SA1, the air pump 28 is driven and 2
When the two switching valves 26 and 46 are simultaneously switched to the pressure supply state, rapid pressure increase of the two cuffs 20 and 40 at the same pressure increasing speed is started. Time t _{0 in} FIG. 7A shows this state.

In the following SA2, the two cuffs 20 and 40
Cuff pressure P_C1・ P_C2Is preset to about 180mmHg
Target pressure P_cmIt is determined whether or not the above has been achieved. This S
When the determination of A2 is denied, the determination of SA2 is repeated.
The cuff pressure P _C1And P_C2Of rapid boost
The state continues.

When the determination in SA2 is affirmative due to the increase in the cuff pressures P _C1 and P _C2 , in subsequent SA3, the air pump 28 is stopped and the switching valves 26 and 46 are switched to the slow exhaust pressure state. Thus, the pressure in each of the cuffs 20 and 40 is lowered at a predetermined gentle speed of about 3 mmHg / sec. 7 time t ₁ of the (a) shows this state.

At SA4, the pulse wave signal SM ₁ sequentially supplied from the pulse wave discrimination circuit 32 and the pulse wave signal SM ₂ sequentially supplied from the pulse wave discrimination circuit 50 are read, and the tibial artery wave and the brachial artery wave are obtained. It is determined whether or not one beat has been detected. If this determination is denied, the determination of SA4 is repeatedly performed. If the determination is affirmed, the blood pressure value determination routine of SA5 is performed. That is, the amplitude (peak value) of the tibial artery wave and the amplitude (peak value) of the brachial artery wave for each beat are determined, and based on a change in the amplitude, a well-known oscillometric blood pressure value determination algorithm is used. ankle blood pressure BP _L and the upper arm blood pressure BP _U is determined in accordance with. FIG. 7B shows an example of a change with time of the amplitude of the tibial artery wave and the amplitude of the brachial artery wave sequentially determined in SA5. In addition to the determination of the blood pressure, the cuff 20 connected to each of the switching valves 26 and 46 with respect to the opening degree of each switching valve 26 and 46 is determined.
Rate of change of - 40 of the cuff pressure P _{C1-P C2} is stored in the RAM 60.

At SA6, it is determined whether or not the ankle systolic pressure _BPLSYS has been determined in the blood pressure value determination routine of SA5. If this determination is denied, S
A9 and below are directly executed. However, if the determination in SA6 is affirmative, in subsequent SA7, the ankle systolic pressure BP _LSYS is determined as the predicted lower limb systolic pressure EBP _LSYS . Therefore, SA5 and SA7 correspond to the predicted lower limb blood pressure value determining means 72. Then, in SA8, the time at which the ankle systolic pressure BP _LSYS is determined is stored in the RAM 60. In FIG. 7A, t ₂ indicates the time when the ankle systolic pressure BP _LSYS is determined.

When the determination at SA6 is denied, or when SA8 is executed, at SA9, the upper arm systolic pressure BP is determined in the blood pressure value determination routine at SA5.
_It is determined whether _USYS has been determined. If this determination is denied, SA12 and below are directly executed. However, if the determination in SA9 is affirmative, in subsequent SA10, the upper arm systolic pressure BP _USYS is determined as the predicted upper limb systolic pressure EBP _USYS . Therefore, SA5 and S
A10 corresponds to the predicted upper limb blood pressure value determining means 74. Then, in SA11, the time at which the upper arm systolic pressure BP _LSYS is determined is stored in the RAM 60. T _{3 in} FIG.
Indicates the time when the upper arm systolic pressure BP _USYS is determined. Note that, in the example of FIG. 7, the case where the ankle systolic pressure BP _LSYS is determined before the upper arm systolic pressure BP _{US YS} , that is, the case where the ankle systolic pressure BP _LSYS is higher than the upper arm systolic pressure BP _USYS Is shown.

If the determination in SA9 is denied, or if SA11 is executed, in subsequent SA12,
In the blood pressure value determination routine of SA5, it is determined whether or not both the diastolic blood pressure values BP _LDIA and BP _{UDIA at the} two sites have been determined. While this determination is denied, the above SA4 and subsequent steps are repeatedly executed, the amplitude of the tibial artery wave and the amplitude of the brachial artery wave are determined for each beat, and the blood pressure value determination routine is performed based on the change in the amplitude. To be continued.

When the determination at SA12 is affirmative, subsequently, at SA13 corresponding to the first cuff pressure control means 70, the two switching valves 26 and 46 are switched to the rapid exhaust pressure state, so that two cuffs are released. The pressure inside 20 and 40 is rapidly exhausted.

At SA14, the time t ₂ stored at SA8 and the time t ₃ stored at SA10 are stored.
, That is, the time difference Δt from when the ankle systolic pressure BP _LSYS is determined to when the upper arm systolic pressure BP _USYS is determined, and the routine is terminated.

The first blood pressure measurement routine of FIG. 5 ends.
Then, the second blood pressure measurement routine shown in FIG. 6 is executed.
Is done. Cuff pressure P in FIG._C1And P_C2The control of
Predicted lower limb systolic pressure EBP determined in FIG._LSYSYou
And predicted upper extremity systolic pressure EBP _USYSTo match the control
As an example, the control of the cuff pressure shown in FIG.
In FIG. 5, the predicted ankle systolic pressure BP_LSYSBut
Predicted upper arm systolic pressure BP _USYSIf the decision is higher than
An example. Note that the blood pressure measurement routine of FIG.
Is set to about 10 seconds after the blood pressure measurement routine is completed.
It is executed after a predetermined time has passed.

In FIG. 6, first, SB1 to SB3 corresponding to the second cuff pressure control means 76 are executed. SB1
In the control of the cuff pressure P _C of the predicted systolic pressure EBP _SYS low side of the cuff (cuff pressure P _C2 in FIG. 6) is started. That is, the air pump 28 is driven, and
By switching valve 46 is switched to a pressure supply state, is quickly increased onset of cuff pressure P _C2 (in FIG. 3 described above t
₀ indicates this state. ), The cuff pressure P _{C2 of which} is 18
After being quickly increased to a predetermined target pressure value P _CM which is set to about 0 mmHg, preset speed (e.g. 3mm by switching valve 46 is switched to the slow exhaust pressure condition
(About Hg / sec). Incidentally, the second opening of the valve of the switching valve 46 in the blood pressure measurement is stored in the RAM60 in blood pressure measurement for the first time, based on the relationship between the valve of the switching valve 46 opening and rate of change of the cuff pressure P _C2 Is determined. Thus, the cuff pressure P _C2 is the slow is stepped down at precisely the preset speed.

In the following SB2, t₀Time from Figure 5
It is determined whether or not the time difference Δt calculated in SA14 has elapsed.
Refused. If this judgment is denied, the SB2 judgment
It is repeatedly executed, but if affirmative, the next SB
Cuff pressure P at 3_C1Is started. This cuff pressure
P_C1Is controlled by the cuff pressure P_C2And cuff pressure P_C1of
Rapid boosting is started (t in FIG. 3).₁Indicates this state.
You. ), Its cuff pressure P _C1Is cuff pressure P_C2Same target pressure value as
P_cmCuff pressure up to_C2Was rapidly boosted at the same speed as
After that, the switching valve 26 is switched to the slow exhaust pressure state.
Cuff pressure P_C2The pressure is reduced slowly at the same speed as What
In addition, the opening degree of the switching valve 26 in the second measurement
Is stored in the RAM 68 in the first blood pressure measurement,
The opening degree of the switching valve 26 and the cuff pressure P_C1With the speed of change
Determined based on the relationship. As a result, the cuff pressure P
_C1Accurately reduce the pressure gradually at the preset speed.
Can be

In the following SB4, the pulse wave signals SM ₁ and SM ₂
Is read, and it is determined whether one beat of the tibial artery wave and the brachial artery wave has been detected. If this determination is denied, the determination of SB4 is repeated. If the determination is affirmative, the SB5 blood pressure value determination routine corresponding to the second lower limb blood pressure value determination means 78 and the second upper limb blood pressure value determination means 80 continues. Blood pressure value B such as ankle systolic pressure BP _LSYS based on the change in the amplitude of the tibial artery wave detected in SB4 and SB4.
With P _L is determined, based on the change in the amplitude of the brachial artery pulse wave, the upper arm blood pressure BP _U such brachial systolic pressure BP _USYS
Is determined.

Then, at SB6, it is determined whether or not the blood pressure determination has been completed. When the blood pressure determination has been completed, at SB7 corresponding to the second cuff pressure control means 76, the inside of the cuffs 20 and 40 is rapidly discharged. Pressed.

At SB8 corresponding to the ankle-brachial blood pressure index calculating means 82, the ankle systolic pressure BP _LSYS determined at SB4 is divided by the upper arm systolic pressure BP _{USYS also} determined at SB4 to obtain ABI. Is calculated, and the calculated ABI is displayed on the display 62.

[0040] As described above, according to this embodiment, the second cuff-pressure changing means 76 (SB1 to SB3), the cuff pressure P _C1 is the slow predetermined predicted leg systolic pressure EBP _LSYS step-down process become timing and the predicted upper limb systolic pressure EBP the cuff pressure P _C2 is predetermined in the slow decreasing process
As timing and serving as _USYS matches are controlled cuff pressure P _C1 and the cuff pressure P _C2 is, the cuff pressure P _C1 and the cuff pressure P
_In the control process of _C2, the ankle systolic pressure BP _LSYS is measured by the ankle blood pressure measuring device 16, and the upper arm systolic pressure BP _USYS is measured by the upper arm blood pressure measuring device 18. By ankle brachial index determining means 82 (SB8), on the basis of its ankle systolic pressure BP _LSYS and brachial systolic pressure BP _USYS AB
Since I is calculated, highly accurate ABI can be obtained.

Further, according to the present embodiment, the ankle systolic pressure BP _LSYS actually measured for the living body immediately before the ABI is calculated is calculated by the predicted lower limb blood pressure value determining means 72 (SA5 / SA7). The systolic pressure EBP _LSYS is determined and the predicted upper limb blood pressure value determining means 74 (SA5 / SA10)
Since the upper arm systolic pressure BP _USYS actually measured for the living body immediately before the ABI is calculated is determined as the predicted upper limb systolic pressure EBP _USYS , the ankle contraction in the blood pressure measurement for calculating the ABI is performed. Since the time at which the period pressure BP _{LS YS} is determined and the time at which the upper arm systolic pressure BP _USYS is determined can be accurately matched, a more accurate ABI can be obtained.

Further, according to this embodiment, since the cuff pressure P _C1 and the cuff pressure P _C2 is controlled to be a common value by the first cuff pressure control means 70 (SA1 to SA3),
Predicted lower limb systolic pressure EBP _LSYS and predicted upper limb systolic pressure EBP
It will be decided at a time relatively close to _USYS . Therefore, the influence of the blood pressure fluctuation based on the time difference included in the difference between the predicted lower limb systolic pressure EBP _LSYS and the predicted upper limb systolic pressure EBP _USYS can be reduced, and the time when the ankle systolic pressure BP _LSYS is determined The timing at which the upper arm systolic pressure BP _USYS is determined can be more accurately matched.

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, the ankle blood pressure measuring device 16 provided in the ankle brachial blood pressure index measuring device 10 of the above-described embodiment is
Although only the blood pressure value at one ankle is measured, a device that measures the blood pressure value at both the left and right ankles may be provided. In this case, the cuff pressure of the cuff wrapped around the right ankle and the timing at which the cuff pressure of the cuff wrapped around the left ankle reaches the predetermined predicted left ankle blood pressure value are determined by the second cuff pressure control means. The respective cuff pressures are controlled such that the determined predicted right ankle blood pressure value and the timing at which the cuff pressure of the cuff wound around the upper arm becomes the predetermined predicted upper limb blood pressure value all coincide. Alternatively, it is determined in advance which of the left and right ankle blood pressure values is low, and the cuff pressure of the cuff wound around the lower ankle is the time when the predetermined lower limb blood pressure value becomes the predetermined lower limb blood pressure value, Each cuff pressure may be controlled so that the time when the cuff pressure of the cuff wound on the upper arm reaches a predetermined predicted upper limb blood pressure value.

Further, in the illustrated embodiment, the predicted lower limb by blood pressure determining means 72, ankle ABI was actually measured biological calculated blood pressure values BP _L is predicted blood pressure value EBP
_L has been determined, but the ankle brachial index measurement device 10
May be provided with an input device, and a value input from the input device may be determined as the predicted lower limb blood pressure value EBP _L. Similarly, in the case of the predicted upper limb blood pressure value EBP _U , the value input from the input device may be determined as the predicted upper limb blood pressure value EBP _U.

In the above-described embodiment, the ankle blood pressure measuring device 16 and the upper arm blood pressure measuring device 18 are configured to measure the blood pressure value using the oscillometric method. However, when the Korotkoff sound is generated and disappeared. The blood pressure may be measured by a so-called K-tone method that measures the blood pressure value based on the cuff pressure at the time, or an ultrasonic oscillator placed directly above the artery in the process of changing the compression pressure of the artery and a receiving device. The blood pressure may be measured by an ultrasonic Doppler system in which the opening and closing of the arterial duct is detected by a blood vessel.

In the above-described embodiment, the ankle is selected as the part for measuring the lower limb blood pressure value, and the upper arm is selected as the part for measuring the upper limb blood pressure value. May be selected, or a wrist or fingertip may be selected instead of the upper arm.

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

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of an ankle-brachial index device to which the present invention is applied.

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

3 is an example of control of cuff pressures P _C1 and P _C2 controlled by a second cuff pressure control unit in FIG. 2, showing an example in which a pressure increase start speed is adjusted.

[4] which is an example of the control of the cuff pressure P _C1 and P _C2 is controlled by the second cuff pressure control means of FIG. 2 is a diagram showing an example of the step-down start pressure is adjusted.

5 is a flowchart illustrating a main part of a control operation of the electronic control device of the embodiment of FIG. 1, and is a diagram illustrating an initial blood pressure measurement routine.

FIG. 6 is a flowchart illustrating a main part of a control operation of the electronic control device according to the embodiment of FIG. 1, and is a diagram illustrating a second blood pressure measurement routine.

It is a diagram illustrating the control of Figure 7 (a) cuff pressure first blood pressure measuring routine of Fig. 5 P _C1 and P _C2. (B) FIG.
FIG. 8 is a diagram showing an example of changes over time in the amplitude of the tibial artery wave and the amplitude of the brachial artery wave sequentially determined in the first blood pressure measurement routine of FIG.

[Explanation of symbols]

10: Ankle upper arm blood pressure index measuring device (lower limb upper limb blood pressure index measuring device) 20: Cuff (cuff for lower limb) 16: Ankle blood pressure measuring device (lower limb blood pressure measuring device) 18: Upper arm blood pressure measuring device (upper limb blood pressure measuring device) 40: Cuff (upper cuff) 70: first cuff pressure control means 72: predicted lower limb blood pressure value determining means 74: predicted upper limb blood pressure value determining means 76: second cuff pressure control means 82: ankle upper arm blood pressure index calculating means (lower limb upper limb blood pressure) Index calculation means)

──────────────────────────────────────────────────続 き Continued on the front page (58) Investigated field (Int.Cl. ⁷ , DB name) A61B 5/02-5/0295 INSPEC (DIALOG)

Claims (3)

(57) [Claims] 1. A lower limb blood pressure measurement device for measuring a lower limb blood pressure value in a lower limb based on a pulse wave sequentially obtained in a slowly changing process of a compression pressure of a lower limb cuff wound around a lower limb of a living body; A lower limb upper limb blood pressure index comprising: an upper limb blood pressure measuring device that determines an upper limb blood pressure value in the upper limb based on a sequentially obtained pulse wave in a slowly changing process of the compression pressure of the upper limb cuff wound on the upper limb of the living body The measurement device, wherein the cuff pressure of the cuff for the lower limb, in the slow change process, the time when the predicted lower limb blood pressure value becomes a predetermined lower limb blood pressure value as the predicted value of the lower limb blood pressure value, the cuff pressure of the upper limb cuff, Controlling the cuff pressure of the lower limb cuff and the cuff pressure of the upper limb cuff so that the time when the predicted upper limb blood pressure value becomes a predicted upper limb blood pressure value as the predicted value of the upper limb blood pressure value coincides with the gradual change process. The second mosquito Pressure control means, in the course of controlling the compression pressure of the cuff for the lower limb and the compression pressure of the cuff for the upper limb by the second cuff pressure control means, the lower limb blood pressure value measured by the lower limb blood pressure measurement device and the A lower limb upper limb blood pressure index calculating means for calculating a lower limb upper limb blood pressure index based on the upper limb blood pressure value measured by the upper limb blood pressure measuring device. 2. Prior to lower limb blood pressure measurement for calculating the lower limb upper limb blood pressure index, the lower limb blood pressure measuring device measures the lower limb blood pressure value of the living body, and determines the lower limb blood pressure value as the predicted lower limb blood pressure value. Predicted lower limb blood pressure value determining means, and prior to upper limb blood pressure measurement for calculating the lower limb upper limb blood pressure index, measure the upper limb blood pressure value of the living body by the upper limb blood pressure measurement device, and calculate the upper limb blood pressure value to the predicted upper limb blood pressure value. 2. The lower limb upper limb blood pressure index measuring device according to claim 1, further comprising a predicted upper limb blood pressure value determining means for determining a blood pressure value. 3. The cuff pressure of the cuff for lower limb for measuring the lower limb blood pressure value by the predicted lower limb blood pressure value determining means,
A first cuff pressure control means for controlling a cuff pressure of the cuff for the upper limb for measuring the upper limb blood pressure value by the predicted upper limb blood pressure value determining means using a common value is further included. The lower limb upper limb blood pressure index measuring device according to claim 2.