JP3921775B2 - Blood pressure monitoring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a blood pressure monitoring apparatus that continuously monitors the blood pressure of a living body.
[0002]
[Prior art]
A blood pressure monitoring apparatus that monitors a blood pressure value of a living body over a relatively long period of time has a cuff wound around a part of the living body, and measures the blood pressure value of the living body by changing the compression pressure by the cuff. In general, the blood pressure measuring means is automatically activated at a predetermined cycle. This is because the blood pressure measurement value measured using the cuff by this blood pressure measurement means is relatively reliable.
[0003]
However, in the case of such an automatic blood pressure monitoring apparatus, if the automatic activation cycle is shortened in order to eliminate the delay in blood pressure monitoring, the cuff is pressed against the living body, and thus there is a disadvantage that a heavy burden is imposed on the living body. In addition, if the frequency of cuff compression is extremely high, congestion may occur and an accurate blood pressure value may not be obtained.
[0004]
On the other hand, blood pressure measuring means for changing the pressure of the cuff attached to the living body and measuring the blood pressure value of the living body based on the change of the pulse synchronous wave generated in the process of changing the pressure, and the artery of the living body A pressure pulse wave sensor for detecting a pressure pulse wave generated from the artery by being pressed by the blood pressure, and a magnitude of the pressure pulse wave detected by the pressure pulse wave sensor by activating the blood pressure measurement means at a predetermined cycle. The pressure pulse wave blood pressure correspondence determining means for determining the pressure pulse wave blood pressure correspondence relation with the blood pressure value measured by the blood pressure measuring means, and the monitored blood pressure based on the actual pressure pulse wave from the pressure pulse wave blood pressure correspondence relation There has been proposed a blood pressure monitoring device including monitoring blood pressure value determining means for sequentially determining values. According to this, there is an advantage that a monitoring blood pressure value is obtained for each beat and a delay in blood pressure monitoring is eliminated. For example, a blood pressure monitor device described in JP-A-2-177937 is one example.
[0005]
[Problems to be Solved by the Invention]
However, according to the above blood pressure monitor device, it is necessary to stably press the pressure pulse wave sensor from above the epidermis toward the artery in order to detect the pressure pulse wave generated from the artery of the living body. Since the place where the pulse wave sensor is pressed is limited to the place where the artery is located directly under the epidermis such as the wrist, it may not be used depending on the diseased part of the living body, or the pressure pulse wave sensor may be Even if it is fixed to the body, the pressing state changes due to the body movement of the living body and the pressure pulse wave signal shifts, and there is a problem that accurate monitoring may not be possible.
[0006]
The present invention has been made against the background of the above circumstances, and the object of the present invention is to continuously monitor blood pressure fluctuations without imposing a heavy burden on the living body and without restricting attachment to the living body. An object of the present invention is to provide a blood pressure monitoring device that can perform the above-described operation.
[0007]
The present inventor found out the fact that blood pressure fluctuates when the balance of the autonomic nerves is lost while conducting various studies on the background of the above situation. Autonomic nerves can be evaluated by analyzing fluctuations in heart rate information such as heart rate cycle, heart rate, pulse cycle, and pulse rate. The present invention has been made on the basis of such knowledge, and monitors fluctuations in blood pressure values by analyzing fluctuations in heart rate information so as to avoid blood pressure measurement by cuff as much as possible. It is.
[0008]
[Means for Solving the Problems]
That is, the gist of the present invention for achieving the above object is a blood pressure monitoring device for monitoring a blood pressure value of a living body, and (a) a cuff for changing the pressure applied to a part of the living body. Blood pressure measuring means for measuring the blood pressure value of the living body using (b) heart rate information calculating means for calculating heart rate information of the living body, and (c) fluctuation of heart rate information calculated by the heart rate information calculating means. Frequency analysis means for frequency analysis; (d) autonomic nerve evaluation means for determining an evaluation value indicating the activity state of the autonomic nerve of the living body from the spectrum analyzed by the frequency analysis means; and (e) evaluation of the autonomic nerve. Blood pressure measurement starting means for starting blood pressure measurement by the blood pressure measuring means based on the change in value.
[0009]
【The invention's effect】
In this way, the frequency analysis means performs frequency analysis on the heart rate information of the living body calculated by the heart rate information calculation means, and the autonomic nerve evaluation means evaluates the evaluation value of the autonomic nerve of the living body from the frequency analysis spectrum of the heart rate information. Is determined, and blood pressure measurement by the blood pressure measurement means is activated based on the determination that the evaluation value of the autonomic nerve has fluctuated in the blood pressure activation means. Accordingly, since fluctuations in blood pressure are continuously monitored without using a cuff, it is possible to eliminate blood pressure measurement with a cuff in a short cycle in order to reduce the delay in blood pressure monitoring. Is reduced.
[0010]
Here, preferably, the blood pressure monitoring device calculates a volume pulse wave detection device for detecting a volume pulse wave at a peripheral portion of the living body and an area of the volume pulse wave detected by the volume pulse wave detection device. The blood pressure measurement starting means is configured to determine that the pulse wave area has changed and that the evaluation value of the autonomic nerve has been changed. This activates blood pressure measurement. In this way, the pulse wave area calculating means calculates the area of the peripheral volume pulse wave, the blood pressure measurement starting means determines that the area of the volume pulse wave has changed, and evaluates the autonomic nerve. When it is determined that the value has fluctuated, the blood pressure measurement by the blood pressure measurement unit is activated, so that the cuff is more accurately compared with the case where the activation of the blood pressure measurement by the cuff is determined only by the evaluation value of the autonomic nerve. There is an advantage that it is possible to determine when to start the blood pressure measurement.
[0011]
Preferably, the heartbeat information is calculated based on a volume pulse wave output from the volume pulse wave detection device. In this way, there is an advantage that it is not necessary to separately attach a device for calculating heart rate information to the living body, and the volume pulse wave detection device can be mounted on the living body's epidermis without much restriction. There is an advantage that the pulse wave for calculating the heartbeat information can be easily detected.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration of a blood pressure monitoring apparatus 8 to which the present invention is applied.
[0013]
In FIG. 1, the blood pressure monitoring device 8 has a rubber bag in a cloth belt-like bag and is connected to the cuff 10 wound around the upper arm 12 of a patient, for example, and connected to the cuff 10 via a pipe 20. A pressure sensor 14, a switching valve 16, and an air pump 18 are provided. The switching valve 16 has a pressure supply state that allows supply of pressure into the cuff 10, a slow discharge state that gradually discharges the inside of the cuff 10, and a quick discharge state that rapidly discharges the inside of the cuff 10. It is configured to be switched to one state.
[0014]
The pressure sensor 14 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. Static pressure filter circuit 22 includes a low pass filter, the cuff pressure signal SK via the A / D converter 26 and discriminating the cuff pressure signal SK representative of a steady pressure or cuff pressure P _C is included in the pressure signal SP This is supplied to the electronic control unit 28.
[0015]
The pulse-wave filter circuit 24 includes a band-pass filter, the electronic control and the pulse-wave signal SM ₁ through the A / D converter 29 and discriminating the pulse wave signal SM ₁ which is an oscillating component of the pressure signal SP in frequency Supply to device 28. The cuff pulse wave represented by the pulse wave signal SM ₁ is a pressure vibration wave, that is, a cuff pulse wave generated from a brachial artery (not shown) and transmitted to the cuff 10 in synchronization with the heartbeat of the patient. 14 and the pulse wave discrimination circuit 24 function as a cuff pulse wave sensor.
[0016]
The electronic control unit 28 is constituted by a CPU 30, a ROM 32, a RAM 34, and a so-called microcomputer having an I / O port (not shown). By executing the signal processing while using it, the drive signal is output from the I / O port to control the switching valve 16 and the air pump 18 and the display content of the display 36 is controlled.
[0017]
The photoelectric pulse wave sensor 40 functioning as a volume pulse wave detection device is configured in the same manner as that used for, for example, pulse detection in order to detect a volume pulse wave (plethysmograph) of a peripheral blood vessel of a living body. In the housing 42 that can accommodate a part of a living body such as a cusp, the living body has red light or infrared light in a wavelength band that can be reflected by hemoglobin, preferably a wavelength of about 800 nm that is not affected by oxygen saturation. A light-emitting element 44 that is a light source that irradiates the skin of the skin, and a light-receiving element 46 that is provided on the side of the housing 42 that faces the light-emitting element 44 and that detects light transmitted through a part of the living body. A photoelectric pulse wave signal SM ₂ corresponding to the blood volume in the blood vessel is output and supplied to the electronic control unit 28 via the A / D converter 48. Since the photoelectric pulse wave signal SM ₂ is a signal that pulsates at every beat corresponding to the amount of hemoglobin in the capillary at the peripheral portion, that is, the blood volume, the photoelectric pulse wave sensor 40 detects the heart beat signal of the living body. It also functions as a heartbeat signal detection device.
[0018]
FIG. 2 is a functional block diagram for explaining a main part of the control function of the electronic control device 28 in the blood pressure monitoring device 8. In FIG. 2, the blood pressure measurement means 70 is activated for every predetermined blood pressure measurement cycle, and the cuff pressure control means 72 applies the compression pressure of the cuff 10 wound around the upper arm of the living body to a predetermined target. The pulse wave signal SM ₁ that is sequentially collected is represented in the slow pressure reduction period in which the pressure is increased to a pressure value P _CM (for example, a pressure value of about 180 mmHg) and then gradually reduced at a speed of about 3 mmHg / sec. Based on the change in the amplitude of the pulse wave, a well-known oscillometric method is used to determine the systolic blood pressure value BP _SYS , the mean blood pressure value P _MEAN , the diastolic blood pressure value BP _DIA , and the determined systolic blood pressure value BP _SYS. The average blood pressure value P _MEAN and the minimum blood pressure value BP _DIA are displayed on the display 36.
[0019]
The pulse wave area calculating means 74 calculates the area of the volume pulse wave of the peripheral blood vessel detected by the photoelectric pulse wave sensor 40. Since the pulse wave signal SM ₂ output from the photoelectric pulse wave sensor 40 pulsates for each beat as shown in FIG. 3, the pulse wave area calculation means 74, for example, uses the pulse wave signal SM _2. The pulse wave area A representing the peripheral blood flow is calculated by integrating the intensity of each pulse at every beat or every predetermined number of beats of two or more. Alternatively, it is surrounded by a pulse wave and a line connecting from the rising point of the peak indicated by the alternate long and short dash line C to the rising point of the next peak, as shown by the preset broken line B and beyond the predetermined reference value. The area of the fluctuation component of the pulse wave may be mainly calculated by calculating the area of the range for every beat or every predetermined number of beats of two or more. Since the peripheral blood flow changes corresponding to blood pressure fluctuations, the pulse wave area A changes corresponding to blood pressure fluctuations.
[0020]
The heart rate information calculating means 76 calculates heart rate information relating to the heart rate of the living body, that is, heart rate cycle TP, heart rate PR, pulse rate TM, pulse rate MR, and the like from the heart rate signal detected by the heart rate signal detecting device. For example, by measuring an interval between predetermined portions of the pulse wave obtained from the photoelectric pulse wave signal SM ₂ detected by the photoelectric pulse wave sensor 40, for example, a peak interval or an interval between rising points of the pulse wave, for each beat, TP To decide. FIG. 4 shows an example of the heartbeat period TP continuously determined by the heartbeat information calculation means 76.
[0021]
The pulse wave area correcting unit 78 calculates the peripheral pulse wave area A calculated by the pulse wave area calculating unit 74 by the heart rate information calculating unit 76 and represents the blood flow rate per unit time based on the heart rate information. Normalize or correct as follows. For example, the corrected pulse wave area A ′ is obtained by dividing the pulse wave area A for one beat of the pulse wave signal SM ₂ calculated by the pulse wave area calculating unit 74 by the heartbeat period TP calculated by the heart rate information calculating unit 76. (= A / TP) is determined. The pulse wave area A fluctuates in response to blood pressure fluctuations, but also fluctuates when the heartbeat fluctuates, that is, when the heartbeat period TP fluctuates. For example, when the heartbeat period TP is shortened, the pulse wave area A for each beat decreases. However, since the heart rate TP is shortened and the heart rate PR per unit time is increased, the blood flow volume in the peripheral blood vessels is not necessarily decreased. If the blood flow in the peripheral blood vessels has not decreased, it can be predicted that the blood circulation has not decreased, so blood pressure measurement with the cuff 10 is not required. Therefore, the corrected pulse wave area A ′ representing the blood flow per minute is calculated by dividing the pulse wave area A by the heartbeat period TP.
[0022]
The frequency analysis means 80 uses the well-known fast Fourier transform (FFT) method or autoregressive (AR) method for the fluctuation of the heartbeat period TP continuously determined by the heartbeat information calculation means 76. Perform frequency analysis. As shown in FIG. 4, the heartbeat cycle TP has fluctuations. For example, a spectrum obtained by frequency analysis of a predetermined section previously set using the FFT method includes a respiratory frequency of a living body. A high frequency component HF having a peak in a frequency range substantially equal to the low frequency component, and a low frequency component having a peak in a frequency range sufficiently lower than the respiration frequency of a living body, for example, a frequency range of about 1/3 to 1/4 of the respiration frequency. LF exists. FIG. 5 shows an example of a frequency analysis spectrum of the heartbeat period TP obtained by the frequency analysis means 80.
[0023]
The autonomic nerve evaluation means 82 determines the signal intensity ratio (LF / HF) of the low frequency component LF and the high frequency component HF of the spectrum analyzed by the frequency analysis means 80 as an evaluation value of the autonomic nerve. The ratio (LF / HF) is known to be able to closely correspond to the autonomic nerve activity level in a state where the influence of individual differences is excluded. The change in the diameter of the peripheral blood vessel, that is, the change in the peripheral resistance is under the control of the autonomic nerve, and this peripheral resistance is considered to be largely involved in the fluctuation of blood pressure.
[0024]
The blood pressure measurement activation means 84 activates the blood pressure measurement by the blood pressure measurement means 70 based on the determination that the pulse wave area A has changed and the ratio (LF / HF) has changed. The determination of the fluctuation of the pulse wave area A is performed by, for example, the moving average value A of the determination reference range in which the corrected pulse wave area A ′ corrected by the pulse wave area correcting unit 78 is set in advance, for example, the corrected pulse wave area A ′. _{'AV [= (a' in + ··· +} a 'i-1 + a' it) / (n + 1) ] or abnormal is determined with a that it from the predetermined value or a predetermined percentage change was based on the blood pressure measurement by the previous cuff Judgment by the corrected pulse wave area abnormality determining means 86, and the determination of the fluctuation of the ratio (LF / HF) is, for example, a determination reference range in which the ratio (LF / HF) is set in advance, for example, the ratio (LF / HF). Moving average value (LF / HF) _AV [= {(LF / HF) _in +... + (LF / HF) _i−1 + (LF / HF) _i } / (n + 1)] or according to the previous cuff Based on the time of blood pressure measurement, then a predetermined value or a predetermined percentage Since it is determined by the autonomic nerve abnormality determining unit 88 that determines abnormality based on the change, the blood pressure measuring unit 84 includes, for example, the corrected pulse wave area abnormality determining unit 86 and the autonomic nerve abnormality determining unit 88, and the correction. When the abnormality of the corrected pulse wave area A ′ is determined by the pulse wave area abnormality determining unit 86 and the abnormality of the ratio (LF / HF) is determined by the autonomic nerve abnormality determining unit 88, the blood pressure measuring unit 70 starts blood pressure measurement.
[0025]
FIG. 6 is a flowchart for explaining a main part of the control operation of the electronic control device 28. After an initial process for clearing a counter or register (not shown) is executed in step S1 (hereinafter, step is omitted) in the figure, the signal is output from the photoelectric pulse wave sensor 40 in S2 corresponding to the pulse wave area calculating means 74. pulse wave area a of each one heartbeat is calculated intensity of the photoelectric pulse-wave signal SM ₂ was integrated to.
[0026]
In S3 corresponding to the subsequent heart rate information calculation means 76, the peak interval of the pulse wave detected by the photoelectric pulse wave sensor 40 is measured for each beat, so that the heart rate period TP is sequentially determined as shown in FIG. Is done. In S4 corresponding to the subsequent pulse wave area correction means 78, in order to normalize the pulse wave area A affected by the heartbeat information, the pulse wave area A for each beat calculated in S2 is determined in S3. By dividing by the period TP, a corrected pulse wave area A ′ (= A / TP) representing a blood flow rate per minute is calculated.
[0027]
Next, in S5 corresponding to the frequency analysis means 80, the fluctuation of the heartbeat period TP continuously determined in S3 is subjected to frequency analysis for each beat by using the FFT method in a predetermined section set in advance. . The preset predetermined section is set so that the low-frequency component LF, which is a frequency of about 1/3 to 1/4 of the respiratory frequency of the living body, can be analyzed. It is set as the section from the time of determination to 64 seconds before. When the predetermined section is 64 seconds, analysis is possible in a frequency region of 0.015 Hz or higher.
[0028]
In S6 corresponding to the subsequent autonomic nerve evaluation means 82, the ratio (LF / HF) of the signal intensity between the low frequency component LF and the high frequency component HF on the frequency analysis spectrum of the heartbeat period TP sequentially analyzed in S5. Calculated as an autonomic nerve evaluation value.
[0029]
Subsequently, S7 to S11 corresponding to the blood pressure measurement starting means 84 are executed. That is, in S7 corresponding to the corrected pulse wave area abnormality determining means 86, whether or not the corrected pulse wave area A ′ determined in S4 is abnormal is determined based on, for example, the previous blood pressure measurement by the cuff and then a predetermined value. Alternatively, it is determined that a state in which a change has occurred by a predetermined ratio (for example, 5% up and down) has continuously exceeded a predetermined number of beats, for example, 20 beats or more. If the determination in S7 is negative, S9 and the subsequent steps are directly executed. If the determination is positive, the A ′ flag for indicating an abnormality in the corrected pulse wave area A ′ is turned on in S8. The
[0030]
Next, in S9 corresponding to the autonomic nerve abnormality determining means 88, whether or not the ratio (LF / HF) determined as the evaluation value of the autonomic nerve in S6 is abnormal is based on, for example, the previous blood pressure measurement by the cuff. Then, it is determined that the state that has changed more than a predetermined value or a predetermined ratio (for example, 20% up and down) has continuously exceeded a predetermined number of beats, for example, 20 beats or more. If the determination in S9 is negative, S11 and the subsequent steps are directly executed. If the determination is positive, in S10, the LF for indicating an abnormality in the ratio (LF / HF) that is the evaluation value of the autonomic nerve. The / HF flag is turned on.
[0031]
In S11, it is determined whether or not the A ′ flag is turned on and the LF / HF flag is turned on. If the determination at S11 is negative, S12 is executed. In S12, it is determined whether or not a preset period of about 20 minutes, that is, a calibration period has elapsed since the blood pressure measurement by the cuff 10 was performed last time. If the determination in S12 is negative, S2 and subsequent steps are repeatedly executed.
[0032]
However, if the determination in S11 is affirmed, the corrected pulse wave area A ′ that fluctuates in response to blood pressure fluctuations and the ratio (LF / HF) that is the autonomic nerve evaluation value is an abnormal value. After the characters or symbols indicating the abnormality are displayed on the display 36, blood pressure measurement using the cuff 10 is started in S13, and the measured blood pressure value is displayed on the display 36. Further, when the determination of S12 is affirmed, that is, when the calibration cycle has elapsed, S13 is also executed. After S13 is executed, the steps after S2 are repeatedly executed.
[0033]
As described above, according to the present embodiment, in the frequency analysis unit 80 (S5), the heart rate cycle TP of the living body calculated by the heart rate information calculation unit 76 (S3) is subjected to frequency analysis, and the autonomic nerve evaluation unit 82 ( In S6), the ratio (LF / HF) indicating the evaluation value of the autonomic nerve of the living body is determined from the frequency analysis spectrum of the heartbeat period TP, and the ratio (LF / HF) is determined in the blood pressure activation means 84 (S7 to S11). Based on the determination that the blood pressure has changed, blood pressure measurement by the blood pressure measurement means 70 (S13) is started. Accordingly, since fluctuations in blood pressure are continuously monitored without using a cuff, it is possible to eliminate blood pressure measurement with a cuff in a short cycle in order to reduce the delay in blood pressure monitoring. Is reduced.
[0034]
Further, according to this embodiment, the pulse wave area calculating means 74 (S2) calculates the area A of the peripheral volume pulse wave, and the pulse wave area A is calculated by the pulse wave area correcting means 78 (S4). The blood pressure measurement starting means 84 (S7 to S11) determines that the corrected pulse wave area A ′ has exceeded a preset judgment reference range, and represents the corrected pulse wave area A ′ representing the blood flow per minute. Since the blood pressure measurement by the blood pressure measurement means 70 (S13) is activated when the ratio (LF / HF) that is the evaluation value of the autonomic nerve exceeds a preset criterion range, the evaluation value of the autonomic nerve Compared to the case where the activation of blood pressure measurement by the cuff 10 is determined alone, there is an advantage that the timing for starting the blood pressure measurement by the cuff 10 can be determined more accurately.
[0035]
Preferably, the heartbeat period TP is calculated by measuring the peak interval of the pulse wave obtained from the photoelectric pulse wave signal SM ₂ output from the photoelectric pulse wave sensor 40 for each beat. . Therefore, there is an advantage that it is not necessary to separately attach a device for calculating heart rate information to the living body, and the photoelectric pulse wave sensor 40 can be mounted on the skin of the living body without much restriction. There is an advantage that a pulse wave for calculation can be easily detected.
[0036]
As mentioned above, although one Example of this invention was described based on drawing, this invention is applied also in another aspect.
[0037]
For example, in the above-described embodiment, the photoelectric pulse wave sensor 40 is used as the volume pulse wave detection device, but a photoelectric pulse wave detection probe or an impedance pulse wave sensor used for measuring oxygen saturation is used. May be. The photoelectric pulse wave detection probe is attached to a body surface such as a forehead of a living body, and absorbs light having a wavelength that greatly differs in absorption coefficient between oxygenated hemoglobin and anoxic hemoglobin, and absorption of oxygenated hemoglobin and anoxic hemoglobin. Light of two wavelengths of light having substantially the same wavelength is emitted toward the body surface, and the reflected light or transmitted light of the emitted light from the living body is received by the light receiving element, and a photoelectric pulse wave is output. The impedance pulse wave sensor includes at least two electrodes that are brought into contact with the epidermis of a living body at a predetermined interval, and blood of living tissue located between the two electrodes. An impedance pulse wave corresponding to the volume is output.
[0038]
In the above-described embodiment, the photoelectric pulse wave sensor 40 functioning as a volume pulse wave detection device also functions as a heartbeat signal detection device. However, the upper arm portion is attached to the cuff 10 wound around the upper arm portion 12 of the living body. The cuff pulse wave may be continuously detected by supplying pressure so as to slightly press 12, and the cuff pulse wave may be used as a heartbeat signal. It may be provided as a heartbeat signal detection device.
[0039]
Further, in the blood pressure measurement means 70 of the above-described embodiment, blood pressure measurement is executed at every preset blood pressure measurement cycle and when the blood pressure measurement activation means 84 determines that the blood pressure measurement is activated. The blood pressure measurement may not be performed for each cycle, and the blood pressure measurement may be performed only when the blood pressure measurement activation unit 84 determines that the blood pressure measurement is activated.
[0040]
The blood pressure measuring means 70 of the above-described embodiment is configured to determine the blood pressure value based on the change state of the magnitude of the pressure pulse wave that changes with the compression pressure of the cuff 10 according to the so-called oscillometric method. However, according to the so-called Korotkoff sound method, the blood pressure value may be determined based on the Korotkoff sound that is generated and disappears with the compression pressure of the cuff 10.
[0041]
Further, in FIG. 6 of the above-described embodiment, the cardiac cycle TP of the living body is calculated in S3, and the corrected pulse wave area A ′ is calculated in S4 by dividing the pulse wave area A by the cardiac cycle TP. However, since the heartbeat period TP and the heart rate PR have a one-to-one correspondence, the product of the pulse wave area A and the heart rate PR may be calculated as the corrected pulse wave area A ′. In the present invention, since the heartbeat and the pulse can be treated as equivalent, the pulse wave number MR may be used instead of the pulse period TM or the heart rate PR instead of the heartbeat period TP.
[0042]
In FIG. 6 of the above-described embodiment, in S5 corresponding to the frequency analyzing means 80, the fluctuation of the heartbeat period TP is frequency-analyzed for each beat, but a predetermined number of beats of two or more beats or a predetermined time Frequency analysis may be performed every time.
[0043]
Further, in the above-described embodiment, the blood pressure measurement activation unit 84 determines the fluctuation of the pulse wave area A. In other words, the corrected pulse wave area abnormality determining means 86 determines whether or not the corrected pulse wave area A ′ exceeds the preset judgment reference range, but the fluctuation of the pulse wave area A is not determined. Good. That is, the blood pressure measurement activation means 84 may determine the activation of blood pressure measurement by the blood pressure measurement means 70 by determining only the abnormality of the autonomic nerve.
[0044]
In the above-described embodiment, in the blood pressure measurement starting unit 84, the corrected pulse wave area abnormality determining unit 86 has determined the abnormality of the corrected pulse wave area A ′ representing the blood flow per minute. A change rate or a change amount of a predetermined section of the wave area A ′ may be calculated, and abnormality of the change rate or change amount may be determined. Alternatively, the pulse wave area A that is not corrected, or the change rate or change amount thereof may be determined.
[0045]
In addition, the present invention can be variously modified without departing from the gist of the present invention.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a blood pressure monitoring apparatus according to an embodiment of the present invention.
2 is a functional block diagram for explaining a main part of a control function of the electronic control device of the embodiment of FIG. 1; FIG.
FIG. 3 is a diagram for explaining a photoelectric pulse wave detected by the photoelectric pulse wave sensor of the embodiment of FIG. 1;
4 is a diagram showing fluctuations in a heartbeat cycle TP determined by the heartbeat information detecting means in FIG. 2. FIG.
5 is a diagram showing an example of a spectrum obtained by frequency analysis of the heartbeat period TP of FIG.
6 is a flowchart for explaining a main part of the control operation of the electronic control device of the embodiment of FIG. 1; FIG.
[Explanation of symbols]
8: Blood pressure monitoring device 40: photoelectric pulse wave sensor (volume pulse wave detection device, heart rate signal detection device)
70: Blood pressure measuring means 76: Heart rate information detecting means 80: Frequency analyzing means 82: Autonomic nerve evaluating means 84: Blood pressure measurement starting means 88: Autonomic nerve abnormality determining means

Claims (2)

A blood pressure monitoring device for monitoring a blood pressure value of a living body,
A blood pressure measuring means for measuring a blood pressure value of the living body using a cuff that changes the pressure applied to a part of the living body;
Heart rate information calculating means for calculating heart rate information of the living body;
Frequency analysis means for frequency analysis of fluctuations in heart rate information calculated by the heart rate information calculation means;
Autonomic nerve evaluation means for determining an evaluation value indicating the activity state of the autonomic nerve of the living body from the spectrum analyzed by the frequency analysis means;
A blood pressure monitoring device comprising blood pressure measurement starting means for starting blood pressure measurement by the blood pressure measuring means based on a change in the evaluation value of the autonomic nerve. A volume pulse wave detecting device for detecting a volume pulse wave at a peripheral portion of the living body;
Pulse wave area calculating means for calculating the area of the volume pulse wave detected by the volume pulse wave detection device,
The blood pressure measurement activation means activates the blood pressure measurement by the blood pressure measurement means based on the determination that the area of the volume pulse wave has changed and the evaluation value of the autonomic nerve has changed. The blood pressure monitoring apparatus according to claim 1, wherein

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