JP3621181B2 - Automatic blood pressure measurement device with ECG-induced waveform detection function - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automatic blood pressure measuring apparatus with an electrocardiographic induction waveform detection function for detecting an electrocardiographic induction waveform generated in accordance with an action potential of a subject's myocardium.
[0002]
[Prior art]
As an automatic blood pressure measurement device for measuring the blood pressure of a measurement subject, for example, a pulse wave generated in synchronization with the heartbeat in the cuff in the process of changing the compression pressure of the cuff wound around a part of the living body is used. There is known an automatic blood pressure measuring device that detects and determines a blood pressure value of a living body by a well-known oscillometric method based on a change in the amplitude of the pulse wave. For example, this is an automatic blood pressure measuring device described in Japanese Patent Laid-Open No. 6-292660.
[0003]
By the way, with respect to the automatic blood pressure measuring apparatus as described above, a first support base for supporting one arm of the measurement subject provided with a first electrode for detecting an electrocardiogram-induced waveform, and protruding from the cuff; By providing a second electrode for detecting an electrocardiogram-induced waveform and providing a second support base for supporting the other arm of the measurement subject, detection is performed from both arms of the measurement subject simultaneously with blood pressure measurement. For example, an automatic blood pressure measuring device with an electrocardiographic waveform detection function capable of measuring the propagation speed of a pulse wave propagating through an artery of a living body based on the electrocardiogram waveform is considered.
[0004]
[Problems to be Solved by the Invention]
However, in such an automatic blood pressure measuring device with an electrocardiogram-induced waveform detection function, if an extra force enters the muscle of the arm of the measurement subject supported by the first support base and the second support base, Noise due to electric potential is generated, making it difficult to detect a stable electrocardiogram waveform. For example, when the propagation speed of a pulse wave propagating in a living artery is measured based on the electrocardiogram waveform The measurement accuracy is significantly reduced.
[0005]
The present invention has been made against the background of the above circumstances, and the object of the present invention is to eliminate the occurrence of noise caused by the strain of the arm muscles of the subject and to provide stable electrocardiographic induction. An object of the present invention is to provide an automatic blood pressure measurement device with an electrocardiogram-induced waveform detection function for detecting a waveform.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the gist of the present invention is that an automatic blood pressure measuring device having a through-hole provided on the inner peripheral surface thereof with a cuff that compresses the upper arm of a person to be measured in blood pressure measurement. One arm of the person to be measured protruding from the through hole is provided on the back side of the through hole with a longitudinal support surface for overall support from the elbow to the tip of the arm, A first support base having a first electrode for detecting an electrocardiogram-induced waveform generated in accordance with the action potential of the subject's myocardium on the support surface; and (b) the other arm of the subject. And a longitudinal support surface for overall support from the elbow to the tip of the arm, provided on the opposite side of the through hole, on the support surface, the action potential of the subject's myocardium A second support with a second electrode for detecting an electrocardiogram-induced waveform generated along with the second electrode. Located in.
[0007]
【The invention's effect】
If it does in this way, since it will be supported by the 1st support stand and the 2nd support stand from the elbow of the arm of a to-be-measured person to the front-end | tip part of an arm entirely, it will reach from the elbow to the front-end | tip part of an arm. Because the muscles up to and including the electrode are constantly kept relaxed, there is no extra tension in the arm muscles of the measurement subject's arm that is contacted with the electrode for detecting the electrocardiogram-induced waveform. Therefore, it is possible to detect a stable electrocardiogram waveform. For example, the propagation speed of a pulse wave propagating in a living artery is measured based on the electrocardiogram waveform. In this case, the measurement accuracy can be kept good.
[0008]
Other aspects of the invention
More preferably, in addition to the constituent features of the present invention, the first electrode is provided at the tip of the first support base, and the second electrode is provided at the tip of the second support base. It is characterized by that. In this way, when the arm is brought into contact with the electrode, as a result, the entire area from the elbow to the tip of the arm is supported over the entire support surface of the support base. , Because there is no tension in the muscles of the arm, and it becomes difficult to generate noise due to myoelectric potential, so it is possible to detect a stable electrocardiogram-induced waveform. When the propagation velocity of the pulse wave propagating in the artery of the living body is measured based on the electrocardiogram-induced waveform, the measurement accuracy can be kept good.
[0009]
Preferably, in addition to the constituent features of the present invention, the first support base and the second support base each have a longitudinal concave curved support surface that is recessed from the width direction both ends to the width direction center. It is characterized by being. In this way, the arms of the measurement subject respectively support the first support along the longitudinal concave curved surface that descends gently from the width direction both ends of the first support base and the second support base to the width direction center. Since it is fixed at the center in the width direction of the base and the second support base, when the support surface is flat, extra force in the left and right direction required to fix the arm to the electrode Since the muscle does not become tense and noise due to myoelectricity is less likely to be generated, a more stable electrocardiographic induction waveform can be detected. For example, a living body based on the electrocardiographic induction waveform can be detected. When the propagation speed of the pulse wave propagating in the artery is measured, the measurement accuracy can be kept good.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing an automatic blood pressure measuring device 8 with an electrocardiographic waveform detection function.
[0011]
In FIG. 1, the box 10 is provided with a through hole 14 for inserting the right arm 12 of the person to be measured, and a cuff made of a bag-like flexible cloth and a rubber bag is provided in the through hole 14. A belt 16 having a cylindrical shape with 15 provided on the inner peripheral surface is disposed. Further, a first armrest 17 for supporting the right arm 12 of the person to be measured protruding from the through hole 14 is provided in the back direction of the through hole 14 so as to be inclined upward, and the tip of the first armrest 17 is provided. the parts, in order to detect the ECG waveform generated in association with the action potential of the cardiac muscle of a subject, arranged such that the first electrode 18 _a is good contact to the wrist of the right arm 12 of the subject Has been. The first arm rest 17 corresponds to the first support base, and the first arm rest 17 can detect a right electrocardiographic induction waveform from the wrist of the subject to be detected at all times. A gradual longitudinal recess recessed from both ends in the width direction to the center in the width direction that supports the entire length from the elbow to the wrist so that the muscles from the elbow to the wrist are constantly relaxed. It has a curved support surface.
[0012]
Further, a second armrest 19 for supporting the left arm 13 of the person to be measured is provided horizontally on the left side surface of the box body 10, and at the tip of the second armrest 19 is also the person to be measured. In order to detect the electrocardiogram-induced waveform, the second electrode _18b is disposed so as to make good contact with the wrist of the left arm 13 of the measurement subject. The second armrest 19 corresponds to the second support base, and the second armrest 19 also has the same muscle from the elbow to the wrist of the left arm 13 of the person to be measured as in the first armrest 17. A support surface having a long concave curved surface that is recessed from both ends in the width direction to the center in the width direction, which supports the entire area from the elbow to the wrist so as to be kept in a relaxed state. The operation panel 20 of the box 10 is provided with a start switch 22, a stop switch 24, a printer 26, a card insertion slot 28, and the like, and a display panel 30 has a systolic blood pressure indicator 32, a diastolic blood pressure indicator 34, a pulse. A number display 36 and a time display 38 are provided.
[0013]
FIG. 2 is a block diagram illustrating a circuit configuration of the automatic blood pressure measurement device 8. In the figure, the cuff 15 is connected to the pressure sensor 40, the switching valve 42, and the air pump 44 via a pipe 46, and the switching valve 42 is a pressure supply state that allows the supply of pressure into the cuff 15. The cuff 15 is configured to be switched between three states, a slow exhaust pressure state in which the cuff 15 is gradually exhausted, and a rapid exhaust pressure state in which the cuff 15 is rapidly exhausted. Further, one end of a belt 16 having a cuff 15 provided on the inner peripheral surface and wound in a cylindrical shape is fixed, and the other end is tightened by a drum 50 driven by a DC motor 48 with a speed reducer. ing. The pressure sensor 40 detects the pressure in the cuff 15 and supplies a pressure signal SP representing the pressure to the static pressure discrimination circuit 52 and the pulse wave discrimination circuit 54, respectively.
[0014]
The static pressure discriminating circuit 52 includes a low-pass filter, discriminates a cuff pressure signal SK representing a steady pressure, that is, a cuff pressure included in the pressure signal SP, and electronically transmits the cuff pressure signal SK via an A / D converter 56. This is supplied to the control device 58. The pulse wave discriminating circuit 54 includes a band-pass filter. The pulse wave signal SM ₁ that is a vibration component of the pressure signal SP is discriminated in frequency, and the pulse wave signal SM ₁ is passed through the A / D converter 60. This is supplied to the electronic control unit 58. The cuff-pulse-wave pulse wave signal SM ₁ represents is a pressure oscillation wave that is transmitted to the cuff 15 is generated from the brachial artery (not shown) in synchronism with heartbeat of the subject, the cuff 15, a pressure sensor 40, The pulse wave discrimination circuit 54 functions as a pulse wave sensor.
[0015]
The electronic control unit 58 includes a CPU 62, a ROM 64, a RAM 66, and a so-called microcomputer having an I / O port (not shown). The CPU 62 stores in the ROM 64 in advance using the temporary storage function of the RAM 66. The input signal is processed according to the procedure, and a drive signal, a display signal, and the like are output. That is, when measuring blood pressure, the CPU 62 drives the DC motor 48 with a speed reducer according to a predetermined procedure to wind the cuff 15 around the upper arm of the living body, and drives the air pump 44 to move the upper arm with the cuff 15. Part compress and then by driving the switching valve 42 gradually down the pressing pressure of the cuff 15, blood pressure oscillometric method, based on the pulse wave signal SM ₁ and the cuff pressure signal SK obtained at the slow decreasing process The blood pressure value is determined and displayed on the systolic blood pressure display 32 and the diastolic blood pressure display 34, and simultaneously stored in the blood pressure value storage area 69 of the storage device 68. The storage device 68 is a well-known storage device such as a magnetic disk, a magnetic tape, a volatile semiconductor memory, or a nonvolatile semiconductor memory.
[0016]
The electrocardiograph 70 continuously detects a so-called electrocardiogram, ie, an electrocardiogram showing the action potential of the myocardium through a pair of electrodes 18 brought into contact with the wrist of the right arm 12 and the wrist of the left arm 13 of the measurement subject. The signal SH indicating the electrocardiographic induction waveform is supplied to the electronic control unit 58.
[0017]
FIG. 3 is a flowchart for explaining a main part of the control operation of the electronic control unit 58. In step SA1 (hereinafter step is omitted) in the figure, it is determined whether or not the magnetic card 74 has been inserted into the card insertion slot 28 of the card reading device 72. If the determination at step SA1 is negative, this routine is terminated. If the determination is affirmative, the ID signal recorded on the magnetic card 74 is read at SA2.
[0018]
In the subsequent SA3, it is determined whether or not the read ID signal is registered in advance in the storage area of the storage device 68. If the determination of SA3 is negative, that is, if the ID signal recorded on the magnetic card 74 is not registered, SA15 described later is executed and the magnetic card 74 is sent out from the card insertion slot 28. However, if the determination at SA3 is affirmative, that is, if the ID signal recorded on the magnetic card 74 has already been registered, it is determined at SA4 whether the start switch 22 for blood pressure measurement has been operated. .
[0019]
If the determination of SA4 is denied, the process waits until it is affirmed. However, if the determination at SA4 is affirmative, first at SA5, the switching valve 42 is switched to the pressure supply state and the air pump 44 is driven to set the cuff pressure P to a preset target cuff pressure P ₁ (for example, After the pressure is increased to a pressure of about 180 mmHg, the air pump 44 is stopped. Next, at SA6, the switching valve 42 is switched to the slow exhaust pressure state so that the slow pressure reduction in the cuff 15 is started.
[0020]
Subsequently, in SA7, the pulse wave is read pulse wave signal SM ₁ is whether or not the detected one beat is determined. If this determination is negative, SA7 is repeatedly executed. If the determination is positive, a blood pressure value determination routine of SA8 is executed. In this blood pressure value determination routine, the maximum blood pressure value SBP ₁ , according to a well-known oscillometric blood pressure value determination algorithm, based on the change in the amplitude of the pulse wave sequentially detected in the process of gradually decreasing the cuff pressure P, The minimum blood pressure value DBP ₁ and the average blood pressure value MBP ₁ are determined, and the pulse rate HR ₁ is determined based on the pulse wave generation interval.
[0021]
Next, in SA9, it is determined whether or not the maximum blood pressure value SBP ₁ and the minimum blood pressure value DBP ₁ are determined. If this determination is denied, SA7 to SA9 are repeatedly executed. If this determination is affirmed, in the subsequent SA10, the measured systolic blood pressure value SBP ₁ , diastolic blood pressure value DBP ₁ , average The blood pressure value MBP ₁ , the pulse rate HR ₁ and the measurement date and time are stored for each person to be measured in the blood pressure value storage area 69 of the storage device 68, and the systolic blood pressure display 32, the diastolic blood pressure display 34, and the pulse rate display. Each is displayed on the device 36.
[0022]
Then, at SA11, the time difference TD _RP from R-wave of the ECG waveform as shown in FIG. 4 to the lower peak of the cuff pulse wave is detected. Subsequently, in SA12, the propagation velocity V _M1 of the cuff pulse wave is calculated based on the time difference TD _RP actually detected in SA11 from Equation 1 stored in advance. In Equation 1, L is the distance (m) from the left ventricle through the aorta to the pressed portion of the pressure sensor 40, and T _PEP is the precursor emission from the R wave of the electrocardiogram-induced waveform to the lower peak point of the cuff pulse wave. Time (sec). Values obtained experimentally in advance are used for the distance L and the precursor ejection time T _PEP .
[0023]
[Expression 1]
V _M1 = L / (TD _RP −T _PEP )
[0024]
Subsequently, in SA13, when the switching valve 42 is switched to the rapid exhaust pressure state, the rapid exhaust pressure in the cuff 15 is started. In SA14, the systolic blood pressure value SBP _{1 and the} like are displayed on the recording paper by the printer 26. Then, by executing SA15, the magnetic card 74 is sent out from the card insertion slot 28.
[0025]
As described above, according to the present embodiment, the first armrest 17 (corresponding to the first support base) and the second armrest 19 (corresponding to the second support base) are connected to the tip of the measurement subject from the elbows of both arms. Since the muscle from the elbow to the tip of the arm is constantly relaxed, the electrode 18 for detecting the electrocardiogram-induced waveform is contacted. Since the operator's arm muscles are not strained by excessive force and noise caused by myoelectric potential is less likely to occur, a stable electrocardiogram-induced waveform can be detected. The time difference TD _RP is detected very accurately, and as a result, the measurement accuracy of the propagation velocity V _M1 calculated based on the time difference TD _RP is kept very good.
[0026]
Further, according to the present embodiment, the electrode 18 _a is provided at the distal end portion of the first armrest 17 and the electrode 18 _b is provided at the distal end portion of the second armrest 19, so that the arm is brought into contact with the electrode 18. In this case, as a result, the distance from the elbow to the wrist is entirely supported over the entire support surface of the first armrest 17 and the second armrest 19, so that the arm muscles of the measurement subject are extraneous. forces prevents the nervous enters, since the noise caused by the myoelectric potential is unlikely to occur, since it is possible to detect a more stable ECG waveform, a very time difference TD _RP described above As a result, the measurement accuracy of the propagation velocity V _M1 calculated based on the time difference TD _RP is kept very good.
[0027]
In addition, according to the present embodiment, both arms of the measurement subject are along the longitudinal concave curved surface that gently descends from the widthwise both ends of the first armrest 17 and the second armrest 19 to the widthwise center. Since the first armrest 17 and the second armrest 19 are fixed at the center in the width direction, an extra force in the left-right direction necessary for fixing the arm to the electrode 18 when the support surface is planar is generated. prevents the arm muscles tense on, since the noise caused by the myoelectric potential is unlikely to occur, since it is possible to detect a more stable ECG waveform, very time difference TD _RP described above As a result, the measurement accuracy of the propagation velocity V _M1 calculated based on the time difference TD _RP is kept very good.
[0028]
As mentioned above, although one Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.
[0029]
For example, in the above-described embodiment, the electrocardiogram-induced waveform is used only for calculating the pulse wave velocity, but for example, blood pressure measurement is automatically started when the heartbeat of the measurement subject is stabilized. An electrocardiographic waveform may be used as the starting condition. Even in this case, the more stable the electrocardiographic induction waveform is detected, the easier it is to determine the state in which the heartbeat is stable, so that the determination accuracy is improved. In this manner, the electrocardiographic induction waveform detected through the electrode 18 can be used in various other embodiments.
[0030]
In the above-described embodiment, the electrocardiographic induction waveform is detected from the electrode 18 that is brought into contact with the wrists of both arms of the measurement subject. However, the electrode 18 is configured to be brought into contact with the back of the measurement subject's hand. Even if configured as described above, when the arm is brought into contact with the electrode 18, as a result, the distance from the elbow to the wrist extends over the entire support surface of the first armrest 17 and the second armrest 19. By being supported as a whole, the effect that the extra force enters the arm and it does not become tense is sufficiently produced. Of course, the electrode 18 is not limited to such an installation location, and the temporary effect of stably detecting the electrocardiogram-induced waveform is sufficiently achieved regardless of the location on the support surface. .
[0031]
In the above-described embodiment, the first armrest 17 and the second armrest 19 are provided with a support surface having a long concave curved surface that is recessed from both ends in the width direction to the center in the width direction. It may be a support surface having a shape. Even in such a configuration, since the arm is fixed at a fixed position with respect to the electrode 18, the effect of preventing the arm from being strained due to excessive force in the left-right direction is sufficiently exerted. Of course, the shape of the support surface is not limited to such a shape, and may be flat or cylindrical. Even in such a configuration, the temporary effect of stably detecting the electrocardiographic induction waveform is sufficiently achieved.
[0032]
In the above-described embodiment, the right arm 12 is configured to be inserted into the through hole 14. However, the left arm 13 may be configured to be inserted into the through hole 14 separately. The armrest 17 may be provided horizontally without being inclined upward. In short, the muscles need only be kept relaxed.
[0033]
Various other modifications can be added to the present invention without departing from the spirit of the present invention.
[Brief description of the drawings]
FIG. 1 is a perspective view for explaining an automatic blood pressure measuring apparatus with an electrocardiographic induction waveform detecting function according to an embodiment of the present invention.
FIG. 2 is a block diagram illustrating a circuit configuration of the embodiment of FIG.
FIG. 3 is a flowchart for explaining a main part of control operation of the electronic control device of the embodiment of FIG. 1;
4 is a time chart for explaining a time difference TD _RP obtained by the control operation of the embodiment of FIG. 1; FIG.
[Explanation of symbols]
8: Automatic blood pressure measuring device with electrocardiographic induction waveform detection function 12: Right arm 13: Left arm 14: Through hole 15: Cuff 17: First armrest (first support base)
_18a : 1st electrode _18b : 2nd electrode 19: 2nd armrest (2nd support stand)

Claims (3)

In an automatic blood pressure measuring device with an electrocardiogram-induced waveform detection function having a through-hole provided on the inner peripheral surface with a cuff that presses the upper arm portion of the subject at the time of blood pressure measurement,
Provided on the back side of the through hole having a longitudinal support surface for supporting one arm of the measurement person protruding from the through hole from the elbow to the tip of the arm as a whole. A first support base comprising a first electrode for detecting an electrocardiogram-induced waveform generated on the support surface in accordance with the action potential of the subject's myocardium;
A longitudinal support surface for supporting the other arm of the measurement subject from the elbow to the tip of the arm as a whole, provided on the opposite side of the through hole, on the support surface And a second support with a second electrode for detecting an electrocardiogram-induced waveform generated in accordance with the action potential of the subject's myocardium. Blood pressure measurement device. 2. The automatic with ECG-inducing waveform detection function according to claim 1, wherein the first electrode is provided at a distal end portion of the first support base, and the second electrode is provided at a distal end portion of the second support base. Blood pressure measurement device. The electrocardiographic induction waveform detection function according to claim 1, wherein the first support base and the second support base each have a support surface having a long concave curved surface that is recessed from both ends in the width direction to a center portion in the width direction. Automatic blood pressure measuring device.

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