JPH0690912A - Pulse wave detector - Google Patents

Abstract

PURPOSE:To enable pulse wave detection with high accuracy by deciding the adequateness/inadequateness of the pressing state of a pulse wave sensor in accordance with a change in a min. value tonogram curve of the pulse wave detector which presses the top of the artery on the surface of a living body with the pulse wave sensor and detects pressure pulse waves and correcting a pressing state. CONSTITUTION:The pulse wave sensor 20 constituted by arranging many pressure detecting elements on a pressing surface 28 of a semiconductor chip is mounted by means of a band 14 to the wrist 16 by aligning the arranging direction of the pressure detecting elements intersected to the radial artery 30. Pressure air or the like past a pressure regulating valve 26 is supplied into a pressure chamber 22 within a housing 10 in this state, by which the pulse wave sensor 20 is pressed to the bodily surface 12. The pressure pulse waves are then detected by determining the optimum pressing force and the optimum pressure detecting element in accordance with the pulse wave vibrations obtd. in the boosting process in a controller 32 and the min. value notogram curve connecting the min. values of the pressure pulse waves by the respective pressure detecting elements is determined and the adequateness or inadequateness of the pressing force to the pulse wave sensor 20 is decided from the change thereof with lapse of time. The repressing is executed in the case of inadequateness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse wave detecting device for detecting a pressure pulse wave generated from an artery by pressing the artery on the surface of a living body with a pulse wave sensor.

[0002]

2. Description of the Related Art A pulse wave sensor having a pressing surface on which a plurality of pressure detecting elements are arranged and which is pressed on an artery on the surface of a living body so that the arrangement direction of the pressure detecting elements intersects the artery.
A pressing means for pressing the pressing surface of the pulse wave sensor onto the artery on the surface of the living body, and a pulse wave signal output from the pressure detecting element in the process of continuously changing the pressing force of the pulse wave sensor. The optimum pressing force is determined and the pressing force of the pulse wave sensor is maintained at the optimum pressing force, and based on the pulse wave signal output from the pressure detection element at the optimum pressing force. There is known a pulse wave detecting device of a type that sequentially detects a pressure pulse wave generated from the artery. For example, the one described in Japanese Patent Application Laid-Open No. 1-285244, which the applicant of the present application filed and published earlier, is such.

[0003]

However, in such a pulse wave detecting device, when the pressing state (contact manner, etc.) of the pulse wave sensor against the living body surface changes due to body movement or the like,
Since the detected pressure pulse wave is affected, when the detected pressure pulse wave changes, it is accurately determined whether the change is due to the actual blood pressure fluctuation or the change in the pulse wave sensor pressing state. Is difficult to do
There is a problem that the accuracy of the detected pressure pulse wave cannot be obtained sufficiently.

The present invention has been made in view of the above circumstances. An object of the present invention is to detect the pressure pulse wave by maintaining the pressing force of the pulse wave sensor on the surface of the living body at an optimum pressing force. It is an object of the present invention to provide a pulse wave detection device capable of suitably determining whether or not the pressed state of the pulse wave sensor is appropriate after the start.

[0005]

As a result of various studies to achieve the above object, the present inventor has found that the minimum of each pressure pulse wave obtained from a plurality of pressure detecting elements in the pressed state of the pulse wave sensor. It has been found that the minimum value tonogram curve connecting the values in the arrangement direction is closely related to the pressed state of the pulse wave sensor.

The present invention has been made on the basis of such knowledge, and its gist is to have a pressing surface on which a plurality of pressure detecting elements are arranged, as shown in the claim correspondence diagram of FIG. Then, the pulse wave sensor is pressed onto the artery on the surface of the living body so that the arrangement direction of the pressure detecting elements intersects the artery, and the pressing surface of the pulse wave sensor is pressed onto the artery on the surface of the living body. The optimum pressing force is determined based on the pulse wave signal output from the pressure detecting element in the process of continuously changing the pressing force of the pressing means and the pulse wave sensor, and the pressing force of the pulse wave sensor is optimized. And a pressing force control means for maintaining the pressing force, and a pulse wave detecting device of a type that sequentially detects the pressure pulse wave generated from the artery based on the pulse wave signal output from the pressure detecting element at the optimum pressing force. And (a) the pulse wave After the pressing force of the sensor is maintained at the optimum pressing force, in the two-dimensional coordinate consisting of the lowest value axis representing the lowest value of the pressure pulse wave and the pressure detecting element axis representing the plurality of pressure detecting elements, The lowest value tonogram curve determining means for sequentially determining the lowest value tonogram curve connecting the lowest values of each pressure pulse wave obtained from the pressure detection element, and (b) the lowest value tonogram curve determined by the lowest value tonogram curve determining means. And a pressed state determination means for determining whether or not the pressed state of the pulse wave sensor with respect to the surface of the living body is appropriate.

[0007]

In the pulse wave detecting device having such a structure, when the pressure pulse wave from the artery is successively detected when the pressing force of the pulse wave sensor is maintained at the optimum pressing force by the pressing force control means,
By the lowest value tonogram curve determining means, in the two-dimensional coordinates consisting of the lowest value axis representing the lowest value of the pressure pulse wave and the pressure detecting element axis representing the plurality of pressure detecting elements, each pressure obtained from the plurality of pressure detecting elements. The minimum value tonogram curve connecting the minimum values of the pulse wave is determined, and the pressed state determination means determines whether or not the pressed state of the pulse wave sensor is appropriate based on the change in the minimum value tonogram curve. .

[0008]

Therefore, according to the pulse wave detecting device of the present invention, after the pulse wave sensor starts to detect the pressure pulse wave at the optimum pressing force, the pressing state of the pulse wave sensor on the living body surface is maintained. When it becomes improper, it is judged that the pressing state of the pulse wave sensor is improper based on the change of the minimum value tonogram curve. For example, the pressing force control means is operated again according to the judgment. Since the pressing state of the pulse wave sensor can be corrected by the above, the accuracy of the detected pressure pulse wave can be suitably obtained.

[0009]

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

In FIG. 2, reference numeral 10 denotes a container-shaped housing which is open in one direction, and the wrist 1 is attached by a wearing band 14 with its open end facing the body surface 12 of the human body.
6 is detachably attached. A pulse wave sensor 20 is provided inside the housing 10 so as to be relatively movable via a diaphragm 18 and projectable from an opening end of the housing 10. A pressure chamber 22 is formed by the housing 10 and the diaphragm 18. ing. A pressure fluid such as pressure air is supplied into the pressure chamber 22 from a fluid supply source 24 via a pressure regulating valve 26.
As a result, the pulse wave sensor 20 is pressed against the body surface 12 with a pressing force corresponding to the pressure in the pressure chamber 22. In the present embodiment, the housing 10, the diaphragm 18, the fluid supply source 24, the pressure regulating valve 26, etc. constitute pressing means.

As shown in FIGS. 2 and 3, the pulse wave sensor 20 has a large number (for example, 30) of pressure detecting elements such as pressure sensitive diodes on the pressing surface 28 of a semiconductor chip made of, for example, single crystal silicon. 31 is arranged in one direction, and the pressure vibration wave generated from the radial artery 30 and transmitted to the body surface 12 by being pressed so that the arrangement direction is substantially orthogonal to the radial artery 30. That is, the pressure pulse wave is detected. The distance between the pressure detection elements 31 in the arrangement direction is made sufficiently small so that the necessary and sufficient number of pressure detection elements 31 are arranged on the radial artery 30, and the arrangement length of the pressure detection elements 31 is the radius. It is necessary and sufficiently larger than the diameter of the artery 30. The electric signal output from each pressure detection element 31, that is, the pulse wave signal SM representing the pressure pulse wave is supplied to the control device 32.

The control device 32 includes a CPU 34 and a ROM 3
6, a microcomputer including a RAM 38 and the like. The CPU 34 executes signal processing while utilizing the storage function of the RAM 38 according to a program stored in advance in the ROM 36, and based on the pulse wave signal SM obtained in the pressure increasing process in the pressure chamber 22, the optimum pressing force of the pulse wave sensor 20. And the optimum pressure detecting element 31a of all the pressure detecting elements 31 is determined, and the optimum pressure detecting element 31a is held and the pressure pulse wave is sequentially detected by the optimum pressure detecting element 31a, and the detected pressure pulse wave is displayed. While displaying and recording on the recording device 40, after holding at the optimum pressing force, a minimum value tonogram curve connecting the minimum value of each pressure pulse wave obtained from all the pressure detection elements 31 in the arrangement direction of the pressure detection elements 31 is displayed. The pulse wave sensor 20 is sequentially determined and based on the change of the minimum value tonogram curve with time.
It is determined whether or not the pressing state of the pulse wave sensor 20 against the body surface 12 is appropriate, and when it is determined that the pressing state of the pulse wave sensor 20 is not appropriate due to body movement or the like, the optimum pressing force of the pulse wave sensor 20 or the like is determined. Is determined again and is held at the determined optimum pressing force. Although not shown, a pressure sensor for detecting the pressure in the pressure chamber 22 is provided, and the pressure signal output from the pressure sensor is supplied to the control device 32.

Next, the operation of the pulse wave detecting device constructed as described above will be described with reference to the flowcharts of FIGS. 4 and 5.

After the power is turned on and an unillustrated initial process is executed, when an unillustrated start push button switch is turned on, step S1 is executed. This step S1
Then, the pressure regulating valve 26 is controlled so that the pressure chamber 22 is temporarily exhausted, and then a predetermined constant pressure (for example, 250 mm
The pressure is gradually increased until the pressure reaches about (Hg), and the pulse wave signal SM output from each pressure detection element 31 of the pulse wave sensor 20 in the gradual pressure increase process indicates the pressure in the pressure chamber 22. The signals are sequentially read, the amplitudes of the pressure pulse waves represented by the pulse wave signals SM from the respective pressure detection elements 31 are calculated, and the pressure detection element 31 that has detected the pressure pulse wave with the maximum amplitude serves as the optimum pressure detection element 31a. The pressing force of the pulse wave sensor 20 when the pressure pulse wave having the determined maximum amplitude is detected is determined as the optimum pressing force.

In the following step S2, the pressing force of the pulse wave sensor 20 is held at the optimum pressing force determined in step S1. Therefore, in this embodiment, the above steps S1 and S2, more precisely, the CP
A portion of the U34, the ROM 36, the RAM 38, etc. used for executing step S1 and step S2 corresponds to the pressing force control means.

Next, in step S3, one pressure pulse wave is detected and stored by all the pressure detection elements 31, and in step S4, the pressure pulse wave detected by the optimum pressure detection element 31a is detected. It is displayed and recorded on the display / recording device 40. In a succeeding step S5, it is determined whether or not the content of the flag F is "1". The content of this flag F is "1" in step S10 described later.
Since the content of the flag F is "0" until then, the determination in step S5 is denied and step S6 is executed.

In step S6, it is determined whether or not the pressure pulse wave is detected for eight beats after the optimum pressing force of the pulse wave sensor 20 is first determined and held at the optimum pressing force after the activation push button switch is turned on. Is determined.
If this judgment is negative, steps S3 to S6 are repeatedly executed, but if the judgment of step S6 is affirmative, step S7 is executed, and each pressure detection element 31 before this time. The minimum value of the pressure pulse wave of 8 beats is determined. In the following step S8, the above 8
The average value of the lowest values of the pressure pulse wave of the pulse is calculated for each pressure detection element 31.

In the subsequent step S9, for example, as shown by a solid line in FIG. 6, the lowest axis indicating the lowest value of the pressure pulse wave and the element No. of the total pressure detecting element 31. In the two-dimensional coordinate formed by the axis of the pressure detecting element and the minimum value tonogram curve connecting the average minimum values of the pressure detecting elements 31 is determined. In the next step S10, flag F is set to indicate that the lowest value tonogram curve has been determined.
Is set to "1". In the following step S11, it is determined whether or not the lowest value tonogram curve obtained in step S9 is the first one after being held at the latest optimum pressing force. Initially, the determination in step S11 is positive, so step S12 is executed. The minimum value tonogram curve determined immediately after holding the latest optimum pressing force is hereinafter referred to as a reference curve MTC _s .

In the step S12, the step S
In step 9, it is determined whether or not 15 seconds have elapsed since the lowest value tonogram curve was determined. If this determination is negative, steps S3 to S5 and step S1 are performed.
2 is repeatedly executed to sequentially detect and display the pressure pulse wave. On the other hand, after the above 15 seconds, step S12
If the determination is YES, step S13 is executed to clear the contents of the flag F, and then step S13.
Returned to 5. At this time, the determination in step S5 is denied and the determination in subsequent step S6 is affirmed, so that steps S7 to S9 are executed and, for example, FIG.
At the step S10, the lowest value tonogram curve is determined as indicated by the broken line in FIG.
After the content of is set to "1", step S11 is executed. At this time, since the determination in step S11 is denied, steps S14 and thereafter are executed. The minimum value tonogram curve obtained every 15 seconds after the reference curve MTC _s will be simply referred to as curve MTC.

In step S14, the reference curve M
First area values SL, SM, SR (see FIG. 6) for determining the change pattern of the curve MTC with respect to TC _s are calculated. The first area value SL is, for example, from the value on the curve MTC to the reference curve MTC _s for each of the three pressure detection elements 31 located on one end side (the left end side in FIG. 6) in the arrangement direction of the pressure detection elements 31. The first area value SR is calculated, for example, by adding the values obtained by subtracting the value of 1 above, and the first area value SR is, for example, three pressure detection values located on the other end side (right end side in FIG. 6) in the arrangement direction. It is calculated by adding values obtained by subtracting the values on the reference curve MTC _s from the values on the curve MTC for each of the elements 31. Also, the first area value SM
Is calculated by adding values obtained by subtracting the value on the reference curve MTC _s from the value on the curve MTC for each of the optimum pressure detecting element 31a and the two pressure detecting elements 31 on both sides thereof. is there.

Next, in step S15, the second area value S representing the amount of change in the curve MTC with respect to the reference curve MTC _s is calculated according to equation 1. This second area value S is
For example, as shown in FIG. 7, in a state in which the curve MTC is moved in parallel with respect to the reference curve MTC _s so that the points on the reference curve MTC _s and the points on the curve MTC in the optimum pressure detection element 31a coincide with each other. , Reference curve MTC _s
And a value corresponding to the area of the portion surrounded by the curve MTC.

[0022]

[Equation 1]

Next, at step S16, it is judged if the second area value S is, for example, 80 or less. If this determination is affirmed, it is considered that the change in the pressure pulse wave is due to the blood pressure change and the pressing state of the pulse wave sensor 20 against the body surface 12 is appropriate, and thus step S
17 is executed to clear the contents of the counter C ₁ and the counter C ₂ which will be described later, and then the process returns to step S3 to continue the detection of the pressure pulse wave. On the other hand, step S
When the determination of 16 is denied, step S18 is performed and it is determined whether the second area value S is larger than 400, for example. If this determination is affirmed, the change in the pressure pulse wave is not due to the blood pressure change, but the pulse wave sensor 2
Since it is considered that the pressed state of 0 is unsuitable, step S19 is executed to clear the contents of the counter C ₁ and the counter C ₂ respectively, and then the process is returned to step S1. The optimum pressing force of the sensor 20 is determined again, the optimum pressure detecting element 31a is determined again, and the determined optimum pressing force is held, after which the detection of the pressure pulse wave is restarted.

If the determination in step S18 is negative, that is, if the first area value S is within the range of 80 <S≤400, step S20 is executed to determine the first area value SL and the first area value SL. It is determined whether the area value SM is equal to each other and the first area value SM and the first area value SR are equal to each other. If this determination is positive, step S
21, the change pattern of the curve MTC with respect to the reference curve MTC _s is, for example, in the pattern I shown in FIG.
The pulse wave sensor 2 is equivalent to (a) or (b).
It is determined that the pressed state of 0 is appropriate, and after the contents of the counter C ₁ and the counter C ₂ are cleared in step S17, the process returns to step S3 and the detection of the pressure pulse wave is continued.

If the determination in step S20 is negative, step S22 is executed to execute the first area value SL.
Is smaller than the absolute value of the second area value SM and the absolute value of
It is determined whether the absolute value of the area value SM is larger than the absolute value of the second area value SR. When this determination is affirmative, it is determined in step S21 that the change pattern of the curve MTC with respect to the reference curve MTC _{s corresponds to,} for example, (c) to (j) in the pattern I of FIG. It In (c) to (j) of this pattern I, the curve MTC hardly changes at both end sides with respect to the reference curve MTC _s , and the change of the pressure pulse wave is due to the blood pressure fluctuation, and the pulse wave sensor 20 Indicates that the pressed state of is appropriate. Then, after the contents of the counter C ₁ and the counter C ₂ are cleared in step S17 following step S21, the process returns to step S3 to continue the detection of the pressure pulse wave.

On the other hand, if the determination in step S22 is negative, step S23 is executed and the first area value S
It is determined whether the absolute value of L is larger than the absolute value of the second area value SM and the absolute value of the first area value SM is smaller than the absolute value of the second area value SR. When this determination is affirmed, step S24 is executed and the first area value SL and the first area value SL are determined based on whether or not the value obtained by multiplying the first area value SL and the second area value SR is negative. It is determined whether one of the two area values SR is negative and the other is positive.

When the determination in step S24 is affirmative, the change pattern of the curve MTC with respect to the reference curve MTC _{s corresponds to,} for example, (i) to (l) in the pattern II shown in FIG. 9 in step S25. It is determined to be a thing. This pattern II (i) to (l)
This is because the curve MTC is greatly changed on both end sides with respect to the reference curve MTC _s , and the change of the pressure pulse wave is not due to the blood pressure fluctuation but is due to the improper pressing state of the pulse wave sensor 20. It indicates that there is. Next, in step S26, it is determined whether the second area value S is larger than 150, for example. If this determination is denied, it is determined that the pressed state of the pulse wave sensor 20 is not inappropriate, and in step S27, a counter C ₂ described later is used.
After the content of is cleared, the process returns to step S3 and the detection of the pressure pulse wave is continued.

If the determination in step S26 is affirmative, step S28 is executed, "1" is added to the content of the counter C ₂ , and then step S29 is executed. The counter C ₂ is for counting the number of times that the determination in step S26 is affirmed. Step S
At 29, it is determined whether or not the content of the counter C ₂ is "2". If this determination is denied, that is, if the determination in step S26 is affirmative only once, it is difficult to conclude that the pressed state of the pulse wave sensor 20 is inadequate, so the process returns to step S3. Be done. If the determination in step S29 is positive, the pulse wave sensor 20
For pressing state is considered to be concluded to be inappropriate, step S30 is executed, after the contents of the counter C ₂ is cleared by being returned to the step S1, the pulse wave sensor 20 The optimum pressing force is determined again, the optimum pressure detecting element 31a is determined again, and the determined optimum pressing force is held, after which the detection of the pressure pulse wave is restarted.

When the determination in step S23 is negative, the change pattern of the curve MTC with respect to the reference curve MTC _{s corresponds to,} for example, (a) to (h) in the pattern II shown in FIG. 9 in step S25. After it is determined that it is one, steps S26 and thereafter are executed. In (a) to (h) of this pattern II, the curve MTC is greatly changed at one end side with respect to the reference curve MTC _s , and the change of the pressure pulse wave is not due to the blood pressure change, but the pressure of the pulse wave sensor 20 is pressed. It indicates that the condition is inappropriate.

If the determination in step S24 is negative, that is, if the first area value SL and the first area value SR are both positive or both are negative, then in step S31, the reference curve MTC _s. Curve to MTC
Changes in pattern III shown in FIG. 10, for example.
It is determined to correspond to (a) to (d).
In this pattern III, the curve MTC is the reference curve MTC _s.
On the other hand, both ends are greatly changed, indicating that the change of the pressure pulse wave is not due to the blood pressure change but is due to the improper pressing state of the pulse wave sensor 20. In step S32 following step S31, it is determined whether the second area value S is larger than 80, for example. If this determination is denied, it is considered that the pressed state of the pulse wave sensor 20 was not inappropriate, and therefore, after the content of the counter C ₁ described later is cleared in step S33, the flow is returned to step S3 and the pressure is returned. Pulse wave detection continues.

If the determination in step S32 is affirmative, step S34 is executed, "1" is added to the content of the counter C ₁ , and then step S35 is executed. The counter C ₁ is for counting the number of times the determination in step S32 is affirmed. Step S
At 35, it is determined whether the content of the counter C ₁ is "2". If this determination is denied, that is, if the determination in step S33 is affirmative only once, it is difficult to necessarily conclude that the pressed state of the pulse wave sensor 20 is inadequate, and thus the process returns to step S3. Be done. If the determination in step S35 is positive, the pulse wave sensor 30
Since it is possible to determine that the pressed state of is unsuitable, step S36 is executed, the content of the counter C ₁ is cleared, and then the process returns to step S1, whereby the pulse wave sensor 20 The optimum pressing force is determined again, the optimum pressure detecting element 31a is determined again, and the determined optimum pressing force is held, after which the detection of the pressure pulse wave is restarted. In this embodiment, the above step S
14 to step S36, more accurately, the CPU 34,
Step S14 of the ROM 36 and the RAM 38
The portion used to execute step S36 corresponds to the pressed state determination means.

As described above, according to this embodiment, after the pulse wave sensor 20 starts detecting the pressure pulse wave at the optimum pressing force, the pressing state of the pulse wave sensor 20 against the body surface 12 is inappropriate. When, the pulse wave sensor 20 is pressed based on the change pattern and the change amount of the subsequent curve MTC with respect to the reference curve MTC _s in the appropriate pressed state of the pulse wave sensor 20 obtained immediately after the optimum pressure hold. By determining that the pressing state is inappropriate and restarting from determining the optimum pressing force of the pulse wave sensor 20,
Since the detection of the pressure pulse wave is restarted in a state where the pressed state of the pulse wave sensor 20 is corrected, the accuracy of the pressure pulse wave that is sequentially detected can be suitably obtained.

Although one embodiment of the present invention has been described in detail with reference to the drawings, the present invention can be applied to other modes.

For example, in the above embodiment, the first area values SL, SM, SR for determining the change pattern of the curve MTC with respect to the reference curve MTC _s , and the second area value representing the amount of change of the curve MTC with respect to the reference curve MTC _s . Based on the area value S, whether or not the pressed state of the pulse wave sensor 20 is appropriate is determined, but the first area values SL, SM,
It is also possible to determine the appropriateness of the pressed state of the pulse wave sensor 20 based on only one of SR and the second area value S.

In the above embodiment, the reference curve MTC _s
And the curve MTC is the reference curve MT so that the points on the optimum pressure detection element 31a on the curve MTC match each other.
Although it is moved in parallel with respect to C _s , the curve MTC is moved in parallel so that the reference curve MTC _s and the points on the curve MTC in the predetermined pressure detection element 31 other than the optimum pressure detection element 31 a coincide with each other. You may allow it.

Further, in the above-described embodiment, the pulse wave sensor 20 is pressed based on the change of the subsequent curve MTC with respect to the reference curve MTC _s obtained immediately after the pressing force of the pulse wave sensor 20 is held at the optimum pressing force. Although it is configured that the suitability of the state is determined, this is not always necessary. For example, the curve MTC obtained immediately before the curve MTC is determined.
It is also possible to determine the suitability of the pressed state based on the change in

Further, in the above embodiment, when it is determined that the pulse wave sensor 20 is not properly pressed, it is automatically restarted from step S1. There is no need, for example, the pulse wave sensor 2
The detection of the pressure pulse wave may be terminated after a predetermined alarm or display indicating that the pressed state of 0 is inappropriate is given.

In the above embodiment, step S2
1, S25 and S31 are not always necessary and can be deleted.

Further, in the above-mentioned embodiment, the minimum value tonogram curve is determined every 15 seconds based on the average value of the minimum values of the pressure pulse wave of 8 beats, but this is not always necessary, and for example, for 1 beat The lowest value tonogram curve may be determined for each predetermined time or each beat based on the lowest value of the pressure pulse wave.

Further, in the above embodiment, the pulse wave sensor 2
In order to position 0 in the direction intersecting with the radial artery 30, a driving means such as a motor and a ball screw as described in Japanese Utility Model Application Laid-Open No. 1-126205, which was previously filed and published by the applicant of the present application. May be provided. In this case, when it is determined that the pressed state of the pulse wave sensor 20 is inappropriate and the pulse wave sensor 20 is restarted from step S1, if necessary, the radius of the pulse wave sensor 20 is preceded by the restart of step S1. It may be configured to adjust the position in the direction intersecting with the artery 30.

Further, in the above-mentioned embodiment, the pressure pulse wave detected by the pulse wave detecting device is configured to be displayed and recorded on the display / recording device 40. It is configured to obtain a relationship between the pressure pulse wave and the blood pressure value measured by the cuff in advance, and determine and display the blood pressure value for each beat based on the pressure pulse wave that is sequentially detected from the relationship. Good.

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

[Brief description of drawings]

FIG. 1 is a diagram corresponding to a complaint.

FIG. 2 is a diagram showing an example of the pulse wave detection device of the present invention, and is a block diagram showing the configuration.

FIG. 3 is an enlarged view of the pulse wave sensor of the apparatus of FIG. 2 viewed from the pressing surface side, and is a view schematically showing a pressure detection element.

FIG. 4 is a diagram showing a first half portion of a flowchart for explaining the operation of the apparatus of FIG.

5 is a diagram showing the latter half of the flowchart for explaining the operation of the apparatus of FIG.

FIG. 6 is a diagram showing an example of a reference minimum value tonogram curve MTC _s and a subsequent minimum value tonogram curve MTC determined in step S9 of the flowchart of FIG. 4;

FIG. 7 is a diagram showing a state in which the MTC of FIG. 6 is moved in parallel with respect to MTC _{s so} that points on the optimum pressure detection element coincide with each other.

FIG. 8 is an MT in the case where the pulse wave sensor is pressed properly.
It is a figure showing various examples of change pattern I of C.

FIG. 9 shows M when the pulse wave sensor is pressed in an inappropriate state.
It is a figure showing various examples of change pattern II of TC.

FIG. 10 is a diagram showing various examples of a change pattern III of MTC when the pulse wave sensor is pressed in an inappropriate state.

[Explanation of symbols]

{10: Housing, 18: Diaphragm, 24: Fluid supply source, 26: Pressure regulating valve} Pressing means 12: Body surface 20: Pulse wave sensor 28: Pressing surface 30: Radial artery 31: Pressure detecting element Steps S1, S2: Pushing Pressure control means Steps S7 to S9: Minimum value tonogram curve determination means Steps S14 to S36: Pressed state determination means

Claims (1)

[Claims] 1. A pulse wave sensor having a pressing surface on which a plurality of pressure detecting elements are arranged, and pressed onto an artery on the surface of a living body so that the arrangement direction of the pressure detecting elements intersects the artery.
A pressing means for pressing the pressing surface of the pulse wave sensor onto the artery on the surface of the living body, and a pulse wave signal output from the pressure detecting element in the process of continuously changing the pressing force of the pulse wave sensor. An optimum pressing force is determined and the pressing force of the pulse wave sensor is maintained at the optimum pressing force, and based on a pulse wave signal output from the pressure detection element at the optimum pressing force. A pulse wave detection device of the type that sequentially detects the pressure pulse wave generated from the artery, wherein, after the pressing force of the pulse wave sensor is maintained at an optimum pressing force, the minimum value representing the minimum value of the pressure pulse wave. In two-dimensional coordinates consisting of an axis and a pressure detecting element axis representing the plurality of pressure detecting elements, the lowest value for sequentially determining the lowest value tonogram curve connecting the lowest values of the pressure pulse waves obtained from the plurality of pressure detecting elements. Value tonogram curve determining means, Based on the change of the lowest value tonogram curve determined by the value tonogram curve determining means, including a pressing state determination means for determining whether the pressing state of the pulse wave sensor against the surface of the living body is appropriate. Characteristic pulse wave detection device.