JP3002595B2 - Blood pressure monitoring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art A pulse wave sensor which is pressed onto an artery on the surface of a living body and detects a pressure pulse wave generated from the artery, and the pressing force of the pulse wave sensor is continuously changed, and the pressure is continuously detected in the process. Pressing force adjusting means for determining the optimum pressing force based on the pressure pulse wave to be performed and maintaining the pressing force of the pulse wave sensor at the optimum pressing force, based on the pressure pulse wave sequentially detected at the optimum pressing force 2. Description of the Related Art A blood pressure monitoring device of a type including a blood pressure value determining means for continuously determining a blood pressure value and a display for displaying the blood pressure value is known. For example, the one described in Japanese Utility Model Laid-Open Publication No. 2-82309, which was filed and filed by the present applicant, has been proposed.

[0003]

The optimum pressing force of the pulse wave sensor is usually determined to be the pressing force when a pressure pulse wave having the largest amplitude is detected in the process of changing the pressing force. If the blood pressure monitor is continued for a long time at such an optimum pressing force, the living body may feel the pressing by the pulse wave sensor as a burden.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a blood pressure measurement system based on a pressure pulse wave detected by a pulse wave sensor pressing an artery on the surface of a living body. An object of the present invention is to reduce a burden on a living body due to pressing of a pulse wave sensor in a blood pressure monitoring device that continuously measures a value.

[0005]

As a result of various studies, the present inventor has found that a first upper peak of a pressure pulse wave detected by a pulse wave sensor and a second upper peak appearing after the first upper peak. Since there is a close relationship between the peak interval between the peak pressure and the diastolic blood pressure value, if the blood pressure value monitored at the optimal pressing force is stable, Therefore, even if the pressing force of the pulse wave sensor is reduced from the optimum pressing force so that the actual peak interval is maintained within a range that hardly changes,
Based on the peak interval, it is possible to know whether or not the blood pressure value is in a stable state, and as a result, it has been found that the blood pressure value can be monitored with the pressing force of the pulse wave sensor lowered. The second upper peak is formed when the pulse-like blood flow sent out from the heart is reflected between the heart and a predetermined reflection point.

The present invention has been made based on such knowledge, and the gist of the present invention is as shown in the claim correspondence diagram of FIG. A pulse wave sensor that detects the generated pressure pulse wave,
A pressing force that continuously changes the pressing force of the pulse wave sensor, determines an optimum pressing force based on the pressure pulse waves sequentially detected in the process, and maintains the pressing force of the pulse wave sensor at the optimum pressing force. A blood pressure monitor device of a type comprising an adjusting means, a blood pressure value determining means for continuously determining a blood pressure value based on a pressure pulse wave sequentially detected at the optimum pressing force, and a display for displaying the blood pressure value. (A) peak interval determination means for determining a peak interval between a first upper peak of the pressure pulse wave and a second upper peak appearing subsequent to the first upper peak; (b)
Blood pressure stability determining means for determining whether or not the blood pressure value continuously measured at the optimum pressing force of the pulse wave sensor is stable; and (c) the blood pressure value is stable by the blood pressure stability determining means. If determined, the stable peak interval storage means for storing the stable peak interval determined by the peak interval determining means, (d) the actual peak interval for the stable peak interval is within a predetermined range A second pressing force adjusting means for lowering the pressing force of the pulse wave sensor by a predetermined value than the optimum pressing force so as to be maintained within the second pressing force and maintaining the reduced pressing force; (e) the second pressing force adjusting means; In a state where the pressing force of the pulse wave sensor is maintained at a pressing force lower than the optimum pressing force by a predetermined value by the pressing force adjusting means, the blood pressure value before the pressing force is reduced by the second pressing force adjusting means is determined. Display hand to be displayed on the display And (f) in a state where the pressing force of the pulse wave sensor is maintained at a pressing force lower than the optimum pressing force by a predetermined value, the peak interval sequentially obtained by the peak interval determining means with respect to the stable peak interval. Blood pressure change determining means for determining whether or not the blood pressure value has changed based on whether or not the blood pressure value is maintained within a predetermined range.

[0007]

In this blood pressure monitoring device, the blood pressure value is continuously determined by the blood pressure value determining means based on the pressure pulse wave sequentially detected by the pulse wave sensor maintained at the optimum pressing force by the pressing force determining means. If the blood pressure value at the optimum pressing force is determined to be stable by the blood pressure value stability determination means, the peak interval determination means The stable-time peak interval obtained in the step is stored by the stable-time peak interval storage means, and the actual peak interval is maintained within a predetermined range with respect to the stable-time peak interval by the second pressing force adjusting means. Thus, the pressing force of the pulse wave sensor is made lower than the optimum pressing force by a predetermined value, and is maintained at the reduced pressing force. In the state where the pressing force of the pulse wave sensor is maintained at the pressing force lower than the optimum pressing force by a predetermined value, the display means displays the blood pressure value before the pressing force is lowered on the display, The blood pressure change determining means determines whether or not the blood pressure value has changed based on whether or not the peak interval sequentially obtained by the peak interval determining means is maintained within a predetermined range with respect to the stable peak interval. Is determined.
In this case, since the peak interval is closely related to the diastolic blood pressure value, the peak interval in a state where the pressing force is reduced is maintained within a predetermined range with respect to the stable peak interval at the optimum pressing force. Means that the blood pressure value has hardly changed, and that the peak interval in the state where the pressing force is reduced is not maintained within the predetermined range with respect to the peak interval at the time of stability. This indicates that at least the minimum blood pressure value among the blood pressure values has changed.
Accordingly, the blood pressure value changes relatively largely in a state where the pressing force of the pulse wave sensor is maintained at the pressing force lower than the optimum pressing force by a predetermined value, and the peak interval is maintained within a predetermined range with respect to the stable peak interval. Until it is determined that no
The blood pressure value before the pressure reduction may be displayed on the display as the current blood pressure value. As a result, when the blood pressure value is stable, the blood pressure value can be appropriately monitored even if the pressing force of the pulse wave sensor is reduced below the optimum pressing force, so that the burden on the living body due to the pressing of the pulse wave sensor is reduced. It can be reduced appropriately.

[0008]

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

FIG. 2 is a diagram showing an example of the configuration of the blood pressure monitor device of the present invention, which is used, for example, to monitor the condition of a patient during or after an operation. In the figure, reference numeral 10 denotes a rubber bag-shaped cuff, for example, an upper arm 12 of a patient.
It is attached in a state wound around. A pressure sensor 14, a switching valve 16, and an air pump 18 are connected to the cuff 10 via a pipe 20. Switching valve 16
Switches between three states: a pressure supply state in which the supply of pressure into the cuff 10 is permitted, a slow discharge state in which the cuff 10 is gradually discharged, and a rapid discharge state in which the cuff 10 is rapidly discharged. It is configured to be. Pressure sensor 1
4 detects the pressure in the cuff 10 and supplies a pressure signal SP representing the pressure to the static pressure discrimination circuit 22 and the pulse wave discrimination circuit 24, respectively. The static pressure discriminating circuit 22 includes a low-pass filter, discriminates a cuff pressure signal SK representing a steady pressure included in the pressure signal SP, and converts the cuff pressure signal SK through an A / D converter 26 to a control device 28. Supply to The pulse wave discrimination circuit 24 includes a band-pass filter, discriminates a pulse wave signal SM ₁ which is a vibration component of the pressure signal SP, and converts the pulse wave signal SM ₁ to the control device 28 via the A / D converter 30. Supply. The pulse wave represented by this pulse wave signal SM ₁ is
These are pressure vibration waves generated from a brachial artery (not shown) and transmitted to the cuff 10 in synchronization with the heartbeat of the patient.

The control device 28 includes a CPU 29, a ROM
31, a so-called microcomputer having a RAM 33, an I / O port (not shown), and the like.
The CPU 29 outputs a drive signal from an I / O port by executing signal processing using a storage function of the RAM 33 in accordance with a program stored in the ROM 31 in advance, and switches the switching valve 16 and the air through a drive circuit (not shown). By controlling the pump 18, the pressure in the cuff 10 is adjusted, and the systolic blood pressure value and the diastolic blood pressure value are determined based on the pulse wave represented by the pulse wave signal SM ₁ that is sequentially collected in the step of decreasing the pressure in the cuff 10, for example. The blood pressure value such as a value is determined, the determined blood pressure value is displayed on the display 32, and the blood pressure measurement is repeatedly performed at predetermined time intervals.

On the other hand, in FIG. 2, reference numeral 34 denotes a pressure pulse wave detecting probe, and a wearing band 40 is provided in a state in which the open end of a housing 36 having a container shape faces a body surface 38 of a human body.
, So that it can be detachably attached to the wrist 42. Inside the housing 36, a diaphragm 44 is provided.
, A pulse wave sensor 46 is provided so as to be relatively movable and protrudable from the open end of the housing 36, and a pressure chamber 48 is formed by the housing 36, 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 pulse wave sensor 46 has a pressing force P corresponding to the pressure in the pressure chamber 48. It is pressed against the body surface 38.

The pulse wave sensor 46 has a semiconductor pressure-sensitive element (not shown) on a pressing surface 54 of a semiconductor chip made of, for example, single crystal silicon or the like.
The pressure wave generated from the radial artery 56 and transmitted to the body surface 38, that is, the pressure pulse wave, is detected by being pressed on the radial artery 56 of the body surface 38 of the second body, and the pulse wave representing the pressure pulse wave is detected. The control device 2 converts the signal SM ₂ through the A / D converter 58.
8

The CPU 29 of the control device 28 has a ROM 31
In accordance with a program stored in advance, signal processing is performed using the storage function of the RAM 33, and a drive signal is output to the air pump 50 and the pressure regulating valve 52 via a drive circuit (not shown) to adjust the pressure in the pressure chamber 48. and determines the optimum pressing force P _s of the pulse wave sensor 46 based on the pressure pulse wave sequentially obtained by the slow boosting process in the pressure chamber 48, the pressure regulating valve 52 the optimum pressing force P _s of the pulse wave sensor 46 and controls so as to maintain the pulse wave sensor 46 at the highest blood pressure value and diastolic blood pressure values measured by the cuff 10 and the optimum pressing force P _s
The relationship between the blood pressure value and the magnitude (absolute value) of the pressure pulse wave is obtained based on the highest value and the lowest value of the pressure pulse wave detected in the above, and the pulse wave sensor 46 sequentially detects the relationship from this relationship. The systolic blood pressure value SYS and the diastolic blood pressure value DIA (monitor blood pressure value) are sequentially determined based on the received pressure pulse wave, and the determined monitor blood pressure value is displayed on the display 32.

The CPU 29 executes signal processing using the storage function of the RAM 33 in accordance with a program stored in the ROM 31 in advance, and determines the first upper peak of the pressure pulse wave detected by the pulse together determine the peak-to-peak time between the second upper peak appearing subsequently to the first upper peak, when the monitor blood pressure value is stable at the optimum pressing force P _s of the pulse wave sensor 46, the stable state The pressing force P of the pulse wave sensor 46 is reduced and maintained at the reduced pressing force P so that the actual peak time is maintained within a predetermined range with respect to the peak time. In the state where the pressure P is maintained, the monitor blood pressure value before the pressure P is reduced is displayed on the display 32, and the peak-to-peak time in the state where the pressure P is reduced is shorter than the peak-to-peak time in the stable state. Te is determined whether the blood pressure value has changed based on whether or not it is maintained within a predetermined range, the pressing force P of the pulse wave sensor 46 original if the blood pressure value is changed optimum pressing force P _The blood pressure monitor is performed with the value returned to _s . The second upper peak is formed by the reflection of a pulse-like blood flow sent out from the heart between the heart and a predetermined reflection point. This is called time, and corresponds to the peak interval in the present embodiment.

Next, the operation of the blood pressure monitoring device configured as described above will be described with reference to the flow charts shown in FIGS.

First, in step S1, the pressure in the pressure chamber 48 is gradually increased, and the pressure at which the amplitude of the pressure pulse wave sequentially detected by the pulse wave sensor 46 in the process of gradually increasing the pressure in the pressure chamber 48 is maximized. with pressure or optimum pressing force P _s of the pulse wave sensor 46 in the chamber 48 is determined, the pulse wave sensor 46
The pressing force P of is held in the optimum pressing force P _s. In this embodiment, the air pump 50, the pressure regulating valve 52,
And step S1 (more precisely, CPU 29, ROM
31 and a part of the RAM 33 used for executing the step S1) correspond to the pressing force adjusting means.

Next, in step S2, blood pressure measurement is performed using the cuff 10. That is, for example, the switching valve 1
6 is switched to the pressure supply state and the air pump 18 is activated to increase the pressure in the cuff 10 to a pressure higher than the expected systolic blood pressure value of the patient (for example, 180 mmHg), and then the air pump 18 is stopped and switched. By switching the valve 16 to the slow exhaust pressure state to decrease the pressure in the cuff 10 at a predetermined gentle speed, the amplitude of the pulse wave represented by the pulse wave signal SM ₁ sequentially obtained in the slow pressure decreasing process The blood pressure values such as the systolic blood pressure value and the diastolic blood pressure value are determined according to the well-known oscillometric blood pressure value determining algorithm for determining the blood pressure values such as the systolic blood pressure value and the diastolic blood pressure value based on the change of the blood pressure value. It is. When the blood pressure value is measured by the cuff 10 in this manner, the measured blood pressure value is displayed on the display 32, and the switching valve 16 is switched to the rapid exhaust pressure state, so that the inside of the cuff 10 is quickly exhausted. Pressed.

Next, in step S3, the pulse wave sensor 46
Of the pressure pulse wave (absolute value, ie, pulse wave signal SM ₂₎
Is determined between the blood pressure and the cuff 10. That is, one pulse of the pressure pulse wave from the pulse wave sensor 46 is read and the maximum value and the minimum value of the pressure pulse wave are determined, and the maximum value and the minimum value of the pressure pulse wave and the cuff 10 in step S2. The relationship between the magnitude of the pressure pulse wave and the blood pressure value is determined on the basis of the systolic blood pressure value and the diastolic blood pressure value measured by the above.

Next, in step S4, the optimum pressure pulse wave of the pressing force P _s from the pulse wave sensor 46 is read one beat, in step S5, the maximum value and the minimum value of the loaded pressure pulse wave is It is determined. In the following step S6, based on the relationship obtained in step S3, step S5
The systolic blood pressure value SYS and the diastolic blood pressure value DIA (monitor blood pressure value) are determined on the basis of the maximum value and the minimum value of the pressure pulse wave determined in step S7. In step S7, the determined monitor blood pressure value is displayed on the display. 32 is displayed. In the next step S8, a predetermined time T after the blood pressure measurement by the cuff 10 in the above step S2 is performed.
It is determined whether (for example, 10 minutes) has elapsed.
If the determination in step S8 is affirmed after the lapse of the predetermined time T, the process returns to step S2, and the cuff 10 is returned.
Is measured again and the blood pressure monitor is continued after the relationship is updated, but if the predetermined time T has not yet elapsed and the determination in step S8 is denied, step S9 is executed. .

In step S9, it is determined whether the monitor blood pressure value based on the pressure pulse wave from the pulse wave sensor 46 is stable. The determination as to whether or not this blood pressure value is stable is made, for example, in a certain section (for example, a section of about 10 beats).
Is performed based on whether or not each monitor blood pressure value is within a range of ± 10 mmHg of their average value. In the present embodiment, step S9, more precisely, the CPU 29, the ROM 3
1, and the portion of the RAM 33 used to execute the step S9 corresponds to the blood pressure stability determination means.
If the blood pressure value is determined not to be stable at the step S9, blood pressure monitor is continued based on the pressure pulse wave from the pulse wave sensor 46 at the optimum pressing force P _s by being returned to step S4 If it is determined that the blood pressure value is stable, in step S10, the first upper peak of the pressure pulse wave read this time in step S4 and the second upper peak appearing subsequent to the first upper peak are determined. The inter-peak time (see FIG. 5) is determined. In the following description, the peak-to-peak time when the blood pressure is stable is referred to as a stable-time peak-to-peak time _Nta .

Next, in step S11, step S1
The stable time peak-to-peak time _Nta determined at 0 is stored in a predetermined storage location of the RAM 33, and at step S12, the pressing force P of the pulse wave sensor 46 is increased by a predetermined pressure ΔP (for example, a pressure of about 5 mmHg). Lowered. In the following step S13, one pulse of the pressure pulse wave from the pulse wave sensor 46 is read at the reduced pressing force P, and in step S14, the peak-to-peak time N _tb of the read pressure pulse wave is determined. You. In the present embodiment, the above-mentioned steps S10 and S14, or more precisely, the portion of the CPU 29, the ROM 31, and the RAM 33 used for executing the steps S10 and S14 corresponds to the peak interval determining means. Also,
In the present embodiment, the step S11 (more precisely, the part of the CPU 29, the ROM 31, and the RAM 33 that is used to execute the step S11) and R
A storage location for the stable inter peak time of AM33 N _ta corresponds to the peak interval storage means during stable.

Next, in step S15, step S
It is determined whether or not the inter-peak time N _tb obtained in 14 is within a range of ± α time centered on the stable inter-peak time N _ta . Is set to a relatively short time of about 10 msec, for example, where the stable peak-to-peak time _Nta is 300 msec. If the determination in step S15 is affirmative, that is, if the peak-to-peak time _Ntb is hardly different from the stable peak-to-peak time _Nta even if the pressing force P is reduced, the content of the flag F is set to "1" in step S16. Is determined. Since the content of the flag F is set to "1" in step S19 described later, the determination in step S16 is initially denied,
Accordingly, steps S12 to S16 are repeatedly executed until the determination in step S15 is denied, and the pressing force P of the pulse wave sensor 46 is reduced stepwise.

On the other hand, if the judgment in step S15 is denied, that is, if the inter-peak time N _tb changes relatively more than the stable inter-peak time N _ta by lowering the pressing force P, step S17 is performed. In, it is determined whether or not the content of the flag F is “1”. Initially, the determination in step S17 is denied, and step S18 is executed, so that the previous pressing force P in the stepwise decreasing process of the pressing force P of the pulse wave sensor 46, that is, when the peak-to-peak time N _tb is stable. The pressing force P is held at the pressing force P before being reduced to the pressing force P relatively changed more than the peak-to-peak time _Nta , and in order to indicate that the pressing force P is held, the flag F is set at step S19. The content is set to “1”. Thereby, the pulse wave sensor 4
As shown in FIG. 6, the pressing force P of 6 is reduced as low as possible within a range in which the actual peak-to-peak time _Ntb hardly _differs from the stable peak-to-peak time _Nta . In the present embodiment, the air pump 50, the pressure regulating valve 52, and the steps S12 to S18 (more precisely, C
The part of the PU 29, the ROM 31, and the RAM 33 used for executing the steps S12 to S18) corresponds to the second pressing force adjusting means.

When the pressing force P of the pulse wave sensor 46 is reduced as described above, in step S20, the pressing force P
After the monitor blood pressure value at the time of stability before decreasing the pressure is displayed on the display 32 as the current blood pressure value, the process proceeds to step S13.
In step S1, one pulse is read, and
After the peak-to-peak time N _tb of the pressure pulse wave is determined in step 4, the step S15 is executed. Time between peaks N
_{If tb} is substantially the same as the stable peak-to-peak time _Nta, and the determination in step S15 is affirmative, step S16 is executed. At this time, the content of the flag F is set to "1". Therefore, the determination in step S16 is affirmed, and step S20 is executed. As a result, until the determination in step S15 is denied, steps S13 to S16 and step S20 are repeatedly executed, and the monitor blood pressure value before the pressure P is reduced is continuously displayed on the display 32. In addition,
Since the time between peaks is closely related to the diastolic blood pressure value, the determination is made in step S15 executed when the pressing force P of the pulse wave sensor 46 is reduced to a predetermined pressure and held. An affirmation indicates that at least the diastolic blood pressure value of the blood pressure value has hardly changed, and a negative judgment indicates that at least the diastolic blood pressure value of the blood pressure value has changed. Is shown. In this embodiment,
Step S15, more precisely, the CPU 29, ROM
31 and a portion of the RAM 33 used to execute the step S15 correspond to the blood pressure change determining means, and the step S20, more precisely, the CPU 29, R
The part of the OM 31 and the RAM 33 used for executing the step S20 corresponds to the display means.

When the above-mentioned steps S13 to S16 and step S20 are repeatedly executed, the peak-to-peak time N _tb changes relatively greatly with respect to the stable-time peak-to-peak time N _{ta and} the judgment in step S15 is denied. ,
That is, when the blood pressure value changes, the above-described step S1
At this time, since the content of the flag F is set to "1", the determination in step S17 is affirmed, and step S21 is executed. In step S21, as shown in FIG. 6, the pressing force P of the pulse wave sensor 46 is returned to the optimum pressing force P _s. In a succeeding step S22, the content of the flag F is cleared, and thereafter,
By step S4 following is executed, so that the blood pressure monitor based on the pressure pulse wave from the pulse wave sensor 46 at the optimum pressing force P _s is resumed.

It should be noted that the main routine shown in the flowcharts of FIGS. 3 and 4 preferably determines whether it is necessary to restart from step S1 or step S2 based on predetermined restart conditions. A restart routine (not shown) for determination is interrupted and executed at an extremely short predetermined time interval. As the restart condition, for example, Japanese Patent Application Laid-Open No.
No. 7937 can be used.

According to the present embodiment as described above, when monitoring the blood pressure value at the optimum pressing force P _s of the pulse wave sensor 46 is stable, the actual relative stable inter peak time N _ta In a state where the pressing force P of the pulse wave sensor 46 is lowered as low as possible within a range where the peak-to-peak time N _tb hardly changes, and in a state where the pressing force P is lowered, the monitor blood pressure value at the time of stabilization before being lowered is displayed. Pressing force P
If the actual peak-to-peak time N _tb changes relatively largely with respect to the stable peak-to-peak time N _ta and the blood pressure value changes in a state where
The pressing force P is a blood pressure monitor based on the pressure pulse wave from the pulse wave sensor 46 at the optimum pressing force P _s by being returned to the optimum pressing force P _s of is resumed. Thus, when the blood pressure value is stable, even if the pressing force P of the pulse wave sensor 46 lower than the optimum pressing force P _s, the peak change in blood pressure values at reduced the pressing force P Since the blood pressure value can be suitably monitored by grasping based on the time interval, the burden on the patient due to the pressing of the pulse wave sensor 46 can be suitably reduced.

Also, according to the present embodiment, the pulse wave sensor 46
Since the pressing force P of is configured to be reduced in stages to the limit vicinity of the range that does not almost the actual peak time N _tb against stable inter peak time N _ta, press according to the patient There is an advantage that the pressure P is suitably reduced.

Although 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 above embodiment, the peak interval is represented by the time between peaks, but may be represented by the distance between peaks.

Further, in the foregoing embodiments, it is configured to be returned to the optimum pressing force P _s when the pressure change is detected in the state where the pressing force P of the pulse wave sensor 46 has been lowered, it is not always necessary that, for example, optimum pressing force P that the decision was to determine the new optimum pressing force P _s
You may make it hold to _s .

Further, in the above-described embodiment, the actual peak-to-peak time N _{tb, which} is performed when the pressing force P of the pulse wave sensor 46 is reduced and when the reduced pressing force P is maintained, is stable. The determination as to whether or not the time between peaks _Nta is maintained within a predetermined range is performed in step S15, but the range may be changed to be performed in separate steps. it can.

Further, in the above embodiment, the blood pressure monitor has a blood pressure measuring device using the cuff 10 and determines in advance between the pressure pulse wave from the pulse wave sensor 46 and the blood pressure measured value by the cuff 10. The blood pressure value is configured to be measured based on the pressure pulse wave detected by the pulse wave sensor 46 from the relationship described above. For example, as described in US Pat. Of course, the present invention can also be applied to a blood pressure monitor configured to directly measure the blood pressure value based on the absolute value of the pressure pulse wave.

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 of the present invention.

FIG. 2 is a diagram illustrating a configuration of a blood pressure monitoring device according to an embodiment of the present invention.

FIG. 3 is a diagram showing the first half of a flowchart for explaining the operation of the blood pressure monitoring device of FIG. 2;

FIG. 4 is a diagram showing a latter half of a flowchart for explaining the operation of the blood pressure monitoring device of FIG. 2;

FIG. 5 is a diagram illustrating an example of a pressure pulse wave detected by a pulse wave sensor of the device in FIG. 2, and is a diagram for explaining a time between peaks.

FIG. 6 is a diagram illustrating an example of a state in which the pressing force of the pulse wave sensor of the apparatus in FIG. 2 is reduced.

[Description of sign]

{33 RAM, Step S11} Stable peak interval storage means 38 Body surface 46 Pulse wave sensor # 50 Air pump, 52 Pressure regulating valve, Step S1 Pressing force adjusting means # 50 Air pump, 52 Pressure regulating valve, Steps S12-
S18｝ Second pressing force adjusting means 56 Radial artery Step S9 Blood pressure stability determining means Step S10, S14 Peak interval determining means Step S15 Blood pressure change determining means Step S20 Display means

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) A61B 5/00-5/03

Claims (1)

(57) [Claims] 1. A pulse wave sensor which is pressed onto an artery on the surface of a living body and detects a pressure pulse wave generated from the artery, and the pressing force of the pulse wave sensor is continuously changed, and the pressure is sequentially detected in the process. A pressing force adjusting means for determining an optimum pressing force based on the pressure pulse wave performed and maintaining the pressing force of the pulse wave sensor at the optimum pressing force, based on the pressure pulse wave sequentially detected at the optimum pressing force. What is claimed is: 1. A blood pressure monitor device comprising: a blood pressure value determining means for continuously determining a blood pressure value; and a display for displaying the blood pressure value, wherein the first upper peak and the first upper peak of the pressure pulse wave are provided. A peak interval determining means for determining a peak interval between the second upper peak appearing subsequently, and a blood pressure for determining whether or not a blood pressure value continuously measured at an optimum pressing force of the pulse wave sensor is stable. The blood pressure value is reduced by the stability determination means and the blood pressure stability determination means. If it is determined that the peak interval is stable, a stable peak interval storage unit that stores the stable peak interval obtained by the peak interval determination unit; A second pressing force adjusting means for lowering the pressing force of the pulse wave sensor by a predetermined value from the optimum pressing force and maintaining the pressing force at the reduced pressing force so as to be maintained within the range of In a state where the pressing force of the pulse wave sensor is maintained at a pressing force lower than the optimum pressing force by a predetermined value by the pressure adjusting means, the blood pressure value before the pressing force is reduced by the second pressing force adjusting means is set to the above-mentioned value. Display means for displaying on a display, and in a state where the pressing force of the pulse wave sensor is maintained at a pressing force lower than the optimum pressing force by a predetermined value, the peak interval sequentially obtained by the peak interval determining means is set to be stable. Pea Based on whether or not it is maintained within a predetermined range with respect to the spacing, a blood pressure monitoring device which comprises a change in blood pressure determining means for determining whether or not the blood pressure value is changed.