JPH11342116A - Bloodless continuous hemodynamometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bloodless continuous hemodynamometer to measure blood pressure by inducing vibrations in blood vessels in which blood pressure value measurement precision and reliability are improved. SOLUTION: Plural vibrations of different frequencies are generated by an MPU 6. One of vibrations of different excitation frequencies is induced from the body surface onto an artery in a living body using an excitation device 2. Transmitted waves of the induced vibration is detected by a transmitted wave sensor 3. Phase change in the detected transmitted waves is computed by the MPU 6 to be compared. The most suitable excitation frequency to measurement of blood pressure of each subject is determined as the optimum frequency among the different frequencies. Measurement result by the optimum frequency is compared with result of blood pressure measurement by a hemadynamometer 7 for calibration to determine blood pressure. The optimum frequency and waveform may be selected among plural frequencies and plural waveforms.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-invasive continuous sphygmomanometer, and more particularly, to applying a weak vibration to a blood vessel in a living body, detecting and analyzing the vibration propagated in the blood vessel, and continuously analyzing the blood pressure. It relates to a non-invasive continuous sphygmomanometer for measuring.

[0002]

2. Description of the Related Art As a method for non-invasively and continuously measuring blood pressure, a method disclosed in Japanese Patent Publication No. 9-506024 is known. This is based on the fact that the elasticity of a blood vessel changes in response to a change in blood pressure. By detecting the propagation speed of a signal in the blood vessel, the elasticity of the blood vessel is calculated, and the blood pressure is estimated from the elasticity of the blood vessel. Things. The outline of the processing is as follows. The blood vessel is vibrated from the body surface of the subject, and the vibration propagated on the blood vessel is detected. After converting the detected vibration into a digital signal, filtering processing and phase detection processing are performed, a phase change due to blood pressure fluctuation is calculated, and a change in vibration propagation velocity is obtained. The change in vibration propagation velocity indicates a change in blood vessel elasticity, and the change in blood vessel elasticity indicates a change in blood pressure, that is, a dynamic pressure. This change is calibrated with the measured values of the systolic blood pressure and the diastolic blood pressure by a calibration sphygmomanometer separately installed on the same subject, so that the blood pressure in the living body is measured non-invasively and continuously. The measured blood pressure waveform is displayed along with the electrocardiogram, the respiration curve, and the biological information waveform of the oxygen saturation while being swept over time on the same monitor.

[0003]

In the invention disclosed in Japanese Patent Publication No. Hei 9-506024, the accuracy and reliability of the measured blood pressure value depend on the excitation frequency and the excitation waveform when oscillating the blood vessel. It depends greatly. Further, there is an individual difference in the frequency propagation characteristics of the blood vessels of the subject, and the optimum frequency and the optimum waveform cannot be determined in a unified manner.

[0004] Japanese Patent Publication No. 9-506024 discloses that the excitation frequency at the time of exciting the vibration of a blood vessel in a living body is arbitrary, and the excitation waveform is also a sine wave, a rectangular wave, a triangular wave or any other suitable waveform. It is described that any may be used.
However, there is no description about means for determining an optimal excitation frequency and an excitation waveform for each subject.

The present invention uses a plurality of frequencies and a plurality of waveforms to induce vibrations on a blood vessel wall, so that a more suitable excitation frequency and waveform can be obtained for each subject. It is an object of the present invention to determine and thereby realize a highly reliable and accurate non-invasive continuous sphygmomanometer.

[0006]

In order to solve the above-mentioned problems, the present invention provides a means for vibrating an artery in a living body from a body surface using a plurality of different excitation frequencies and excitation waveforms, Vibration detecting means for converting the vibration transmitted on the artery given by the means into an electric signal, a calibration sphygmomanometer for measuring absolute values of systolic blood pressure and diastolic blood pressure, and a phase of the vibration signal detected by the vibration detecting means Means for calculating a relative change in blood pressure value from the change, and blood pressure calculating means for continuously calculating in-vivo blood pressure based on the calculated change in relative blood pressure value and the measurement value from the calibration sphygmomanometer. Provided, each excitation frequency used when inducing vibration in the blood vessel, performing a circular arc estimation from the phase change and amplitude change of the vibration signal detected by the vibration detection means for the vibration wave having the vibration waveform, Attenuation factor of width, the smallest vibration frequency arc radius variation rate, vibration waveform optimum vibration frequency, which is constituted so as to determine the vibration waveform.

With this configuration, a non-invasive continuous sphygmomanometer that determines a more suitable excitation frequency and excitation waveform for each subject, thereby realizing high reliability and high accuracy. can get.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention provides a vibrating means for vibrating a blood vessel, a vibration detecting means for detecting a vibration transmitted through the blood vessel, and an electric signal from the vibration sensor. A non-invasive continuous sphygmomanometer which comprises a phase detecting means for performing phase detection and a processor means for analyzing the phase detection signal, and continuously and non-invasively measures the blood pressure of a human body by measuring the propagation speed of vibration. Prior to measuring the blood pressure of the subject, means for exciting the blood vessel at a plurality of different exciting frequencies by the exciting means, means for detecting the vibration at each of these exciting frequencies by the vibration detecting means, A non-invasive continuous sphygmomanometer comprising means for analyzing an electric signal from the vibration detecting means to obtain an optimal vibration frequency, and means for determining the vibration frequency of the vibration means as the optimal frequency, Select the best frequency And by blood pressure measurement, it has the effect of improving the reliability and accuracy of blood pressure measurement.

According to a second aspect of the present invention, in the non-invasive continuous sphygmomanometer according to the first aspect, the means for determining the optimal frequency minimizes the attenuation of the excitation signal transmitted through the blood vessel. It has a means for selecting a frequency, and has the effect of measuring blood pressure using an excitation signal having an optimal frequency with little attenuation.

The third aspect of the present invention is the first aspect of the present invention.
The non-invasive continuous sphygmomanometer according to the above, wherein the means for determining the optimal frequency has means for selecting a frequency at which the variance of the amplitude of the excitation signal transmitted through the blood vessel is minimized,
The blood pressure is measured by an excitation signal having an optimal frequency with a small variance.

The fourth aspect of the present invention is the first aspect of the present invention.
In the non-invasive continuous sphygmomanometer according to the above, the means for determining the optimum frequency has means for selecting a frequency at which the phase shift of the excitation signal transmitted through the blood vessel is maximized, and the phase shift is large. This has the effect of measuring blood pressure using the excitation signal of the optimal frequency.

The fifth aspect of the present invention is the first aspect of the present invention.
In the non-invasive continuous sphygmomanometer according to the above, the means for determining the optimal frequency includes: attenuating the excitation signal transmitted through the blood vessel; dispersion of the amplitude of the excitation signal transmitted through the blood vessel; Having a means for selecting a frequency that minimizes the evaluation function including any two or all of the phase shifts described above. Has an action.

According to a sixth aspect of the present invention, there is provided a vibrating means for vibrating a blood vessel, a vibration detecting means for detecting a vibration transmitted through the blood vessel, and a phase detection for phase-detecting an electric signal from the vibration sensor. A non-invasive continuous sphygmomanometer which comprises means for analyzing a phase detection signal and a processor means for analyzing a phase detection signal, and continuously and non-invasively measures the blood pressure of a human body by measuring the propagation speed of vibration. Prior to the measurement, means for exciting the blood vessel with a plurality of different excitation waveforms by the excitation means, means for detecting the vibration in each of the excitation waveforms by the vibration detection means, A non-invasive continuous sphygmomanometer comprising means for analyzing an electrical signal to obtain an optimal excitation waveform, and means for determining the excitation waveform of the excitation means as the optimal waveform. Select a signal to increase blood pressure It has the effect of a constant.

The invention according to claim 7 of the present invention is the invention according to claim 6
In the non-invasive continuous sphygmomanometer according to the above, regarding the method for selecting the optimal waveform, a waveform that minimizes the attenuation of the excitation signal transmitted through the blood vessel is selected, and the excitation signal having the optimal waveform with a small attenuation is selected. It has the effect of selectively measuring blood pressure.

The invention according to claim 8 of the present invention is the invention according to claim 6
The non-invasive continuous sphygmomanometer according to the above, wherein the means for determining the optimal waveform has means for selecting a waveform that minimizes the variance of the amplitude of the excitation signal transmitted through the blood vessel, and the optimal variance is small. This has the effect of selecting an excitation signal having a simple waveform and measuring blood pressure.

The ninth aspect of the present invention is the sixth aspect of the present invention.
In the non-invasive continuous sphygmomanometer according to the above, the means for determining the optimal waveform has means for selecting a waveform that maximizes the phase shift of the excitation signal propagated through the blood vessel, and has a large phase shift. This has the effect of selecting an excitation signal having an optimal waveform and measuring blood pressure.

According to a tenth aspect of the present invention, in the non-invasive continuous sphygmomanometer according to the sixth aspect, the means for determining the optimum waveform comprises: attenuating the excitation signal transmitted through the blood vessel; Means for selecting a waveform that minimizes an evaluation function that includes any two or all of the variance of the amplitude of the excitation signal and the phase shift of the excitation signal transmitted through the blood vessel. This has the effect of selecting a highly efficient excitation signal having an optimal waveform and measuring the blood pressure.

According to the eleventh aspect of the present invention, there are provided a vibrating means for vibrating a blood vessel, a vibration detecting means for detecting a vibration transmitted through the blood vessel, and a phase detecting means for phase detecting an electric signal from the vibration sensor. Means, comprising a processor means for analyzing the phase detection signal, in a non-invasive continuous blood pressure measurement method for continuously and non-invasively measuring the blood pressure of the human body by measuring the propagation speed of the vibration, Prior to blood pressure measurement, a blood vessel is vibrated at a plurality of different vibration frequencies by the vibration means, vibration at each of these vibration frequencies is detected by the vibration detection means, and an electric signal from the vibration detection means is detected. It is a non-invasive continuous blood pressure measurement method in which the optimum excitation frequency is obtained by analyzing and the excitation frequency of the excitation means is the optimum frequency.The blood pressure is measured by selecting the optimum frequency. Measurement It has the effect of improving the reliability and accuracy.

According to a twelfth aspect of the present invention, in the non-invasive continuous blood pressure measuring method according to the eleventh aspect, the method of selecting the optimum frequency is such that the attenuation of the excitation signal transmitted through the blood vessel is minimized. And has the effect of measuring the blood pressure using the excitation signal of the optimal frequency with little attenuation.

According to a thirteenth aspect of the present invention, in the non-invasive continuous blood pressure measuring method according to the eleventh aspect, the variance of the amplitude of the excitation signal transmitted through the blood vessel is minimized with respect to the method of selecting the optimum frequency. To select the frequency
The blood pressure is measured by an excitation signal having an optimal frequency with a small variance.

According to a fourteenth aspect of the present invention, in the non-invasive continuous blood pressure measuring method according to the eleventh aspect, the phase shift of the excitation signal propagated through the blood vessel is maximized with respect to the method of selecting the optimum frequency. The frequency is selected, and has the effect of measuring the blood pressure using the excitation signal of the optimal frequency having a large phase shift.

According to a fifteenth aspect of the present invention, in the non-invasive continuous blood pressure measurement method according to the eleventh aspect, the method of selecting the optimum frequency includes attenuating an excitation signal transmitted through a blood vessel and transmitting a blood vessel. And selecting the frequency that minimizes the evaluation function including any two or all of the variance of the amplitude of the excitation signal and the phase shift of the excitation signal transmitted through the blood vessel. It has the effect of measuring blood pressure with a vibration signal of a good optimal frequency.

According to a sixteenth aspect of the present invention, there is provided a vibrating means for vibrating a blood vessel, a vibration detecting means for detecting a vibration transmitted through the blood vessel, and a phase detection for phase-detecting an electric signal from the vibration sensor. Means, comprising a processor means for analyzing the phase detection signal, in a non-invasive continuous blood pressure measurement method for continuously and non-invasively measuring the blood pressure of the human body by measuring the propagation speed of the vibration, Prior to the blood pressure measurement, a blood vessel is vibrated with a plurality of different vibration waveforms by the vibration means, vibrations at the respective vibration waveforms are detected by the vibration detection means, and an electric signal from the vibration detection means is detected. This is a non-invasive continuous blood pressure measurement method in which an optimal excitation waveform is obtained by analyzing and the excitation waveform of the excitation means is set as the optimal waveform, and a blood pressure is measured by selecting an excitation signal having an optimal waveform. It has the action of:

According to a seventeenth aspect of the present invention, in the non-invasive continuous blood pressure measuring method according to the sixteenth aspect, the method for selecting the optimal waveform is such that the attenuation of the excitation signal propagated through the blood vessel is minimized. And has the effect of measuring the blood pressure by selecting an excitation signal having an optimal waveform with small attenuation.

According to an eighteenth aspect of the present invention, in the non-invasive continuous blood pressure measuring method according to the sixteenth aspect, the variance of the amplitude of the excitation signal transmitted through the blood vessel is minimized with respect to the method of selecting the optimum waveform. This has the effect of selecting an excitation signal having an optimal waveform with small variance and measuring the blood pressure.

According to a nineteenth aspect of the present invention, in the non-invasive continuous blood pressure measuring method according to the sixteenth aspect, the phase shift of the excitation signal propagated through the blood vessel is maximized with respect to the method of selecting the optimum waveform. This has the effect of selecting an excitation signal having an optimal waveform having a large phase shift and measuring the blood pressure.

[0027] According to a twentieth aspect of the present invention, in the non-invasive continuous blood pressure measuring method according to the sixteenth aspect, the method of selecting the optimum waveform includes attenuating an excitation signal propagated through a blood vessel and propagating a blood vessel. And selecting a waveform that minimizes the evaluation function including any two or all of the variance of the amplitude of the applied excitation signal and the phase shift of the excitation signal transmitted through the blood vessel. This has the effect of selecting the excitation signal having a good optimal waveform and measuring the blood pressure.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described in detail with reference to FIG.

(First Embodiment) In a first embodiment of the present invention, prior to the measurement of the blood pressure of a subject, a blood vessel is vibrated at a plurality of different vibration frequencies by vibrating means. Vibration at the excitation frequency is detected by the vibration detection means, and the optimal excitation frequency is determined by analyzing the electric signal from the vibration detection means, and the non-invasive continuous blood pressure with the excitation frequency of the excitation means being the optimal frequency It is total.

FIG. 1 is a block diagram showing the configuration of the non-invasive continuous blood pressure monitor according to the first embodiment of the present invention. In FIG. 1, the exciter sensor 1 is an ultrasonic sensor. The vibrator 2 is an ultrasonic vibrator. The propagation wave sensor 3 is an ultrasonic sensor. The amplifier 4 is an amplifier that amplifies driving ultrasonic waves and ultrasonic waves from the sensor. The AD / DA converter 5 is an AD converter for performing digital conversion and a DA converter for performing analog conversion. The MPU 6 is a processor that generates a waveform, determines an optimal frequency, and performs various arithmetic processing. The calibration sphygmomanometer 7 is a device that measures a reference blood pressure. The monitor 8 is a display device.

The MPU 6 firstly generates an excitation waveform As having a frequency f _1.
in (2πf ₁ t) is generated. The excitation waveform Asin (2πf ₁ t) generated by the MPU 6 is DA-converted by the AD / DA converter 5 and amplified by the amplifier 4. The vibrator 2 induces the excitation waveform Asin (2πf ₁ t) amplified by the amplifier 4 on the blood vessel. The vibration at this time is measured by the vibrator sensor 1, amplified by the amplifier 4, AD-converted by the AD / DA converter 5, and input to the MPU 6.

The propagation wave sensor 3 measures the vibration induced by the vibrator 2 and propagated on the blood vessel wall. The vibration measured by the propagation wave sensor 3 is amplified by the amplifier 4 and AD-converted by the AD / DA converter 5,
Is input to the vibration signal W ₁ as MPU 6. This operation is performed continuously for T seconds. Then, MPU6 generates vibration waveforms of frequency _{f 2 Asin (2πf 2 t)} , through the same process as when the frequency f _1, the vibration signals W ₂ measured by the propagating wave sensor 3, the MPU6 Is entered. _{Similarly, f 3, f 4, ···} , any number of vibration waveforms Asin having a frequency of _{f n (2πf i t) (} i =
The above process is executed for 1, 2,..., N), and the vibration signal W _i (i = 1, 2,.
n) is input. The MPU 6 determines the excitation frequencies f ₁ , f ₂ ,... Based on the signal of the vibration sensor 1 and the vibration signal W _i.
- from among the f _n, to determine the most appropriate excitation frequency for the measurement of the blood pressure of the subject. The MPU 6 vibrates the vibrator 2 at the obtained optimal vibration frequency to induce vibration in the blood vessel, and outputs absolute values of the systolic blood pressure and the diastolic blood pressure output from the calibration sphygmomanometer 7 and the propagation wave sensor. 3, the continuous blood pressure is calculated from the input of the vibration signal detected by the method described in Japanese Patent Application Publication No. 9-506024. The calculated continuous blood pressure value is output to the monitor 8 as a time-series waveform. The monitor 8 also displays the maximum and minimum blood pressure and heart rate for each heartbeat.

As shown in FIG. 2, the first embodiment of the present invention comprises a step 51 of determining an optimum frequency and a step 52 of measuring blood pressure. FIG.
9 shows a procedure of an optimal excitation frequency determining step executed by the PU 6.

In the vibration signal W ₁ input to the MPU 6, the excitation waveform component of the frequency f ₁ is separated from other components by the filtering process in step 101. In step 102, a phase change of the excitation waveform component obtained by the filtering is calculated by a method known as quadrature detection, and a real component (I component) and an imaginary component (Q component) of the phase change are calculated. Is output.

In step 103, as shown in FIG. 4, the center of an arc formed by the I and Q components of the phase change of the excitation waveform formed on the IQ plane is estimated. In step 104,
The center point of the circular arc determined in step 103 and each point (I ₁ ,
_{Q 1), (I 2,} Q 2), determined ..., the average value R _F1Ave of (I _n, the distance between Q _n) (arc _{radius) r 1, r 2, ···} , r n, The attenuation rate P _f1 of the amplitude (arc radius) with respect to the amplitude A _ex of the exciter waveform detected by the exciter sensor 1 is calculated by the following equation. P _f1 = 1 · (R _f1Ave / A _ex )

In step 104, r ₁ , r ₂ ,.
-, also obtained variance value _R f1Var of r _n. Similarly, in step 104, the vibration signal W _2, W _3, · · ·, the W _n,
P _f2 , P _f3 ,..., P _fn , and R _f1Var , R _f2Var ,
..., R _fnVar is calculated.

[0037] At step _105, P _f1, R f1Var calculated in step 104 (i = 1,2, ···, n) on the basis of the most suitable among the f _i in the measurement of the blood pressure of the subject Calculated vibration frequency. In step 105, first, the amplitude attenuation factor P _f1, P _f2, · · ·, and P _fn, arc radius variance value _R f1Var, R f2Var, ···, the standard deviation of _R fnVar P
_Std and R _Std are calculated. Next, using P _Std and R _Std , the optimum excitation frequency determination value Z _fi (i = 1, 2,...,
n) is obtained from the following equation. Z _fi = α · (P _fi / P _Std ) + β · (R _fiVar / R _Std )

[0038] At step 105, the Z _fi is minimized f _i, and outputs a most suitable excitation vibration frequency for the measurement of the blood pressure of the subject. Note that α and β are the respective judgment elements (P _fi
/ P _Std ) and (R _fiVar / R _Std ) are weighting values that are determined according to the degree of importance.

As described above, in the first embodiment of the present invention, the non-invasive continuous sphygmomanometer uses a plurality of different excitation frequencies to vibrate an artery in a living body from the body surface, Vibration detecting means for converting the vibration transmitted on the artery given by the vibration means into an electric signal, a calibration sphygmomanometer for measuring absolute values of systolic blood pressure and diastolic blood pressure, and a vibration signal detected by the vibration detecting means. Means for calculating a relative change in blood pressure value from a phase change, and blood pressure calculating means for continuously calculating in-vivo blood pressure based on the calculated change in relative blood pressure value and a measurement value from a calibration sphygmomanometer A circular arc is estimated from the phase change and the amplitude change of the vibration signal detected by the vibration detection means for the vibration waves having the respective excitation frequencies used when inducing the vibration in the blood vessel, and the amplitude attenuation rate Since it is configured as a circular arc radius of the variation rate is determined as the smallest vibration vibration optimum pressure frequency frequency, to determine a more suitable vibration frequency for each subject,
Thereby, high reliability and high accuracy can be realized.

(Second Embodiment) In a second embodiment of the present invention, prior to the measurement of the blood pressure of the subject, the blood vessel is vibrated by a plurality of vibrations having different waveforms by the vibration means. Vibration in each of these excitation waveforms is detected by the vibration detection means, and the optimal excitation waveform is obtained by analyzing the electric signal from the vibration detection means, and the excitation waveform of the excitation means is set as the optimal waveform. It is a continuous sphygmomanometer.

The second embodiment of the present invention is different from the first embodiment in that a blood vessel is vibrated by using a plurality of waveforms other than a sine wave, such as a rectangular wave and a triangular wave, so that an optimal vibration can be obtained. This is the point that determines the vibration waveform.

The configuration of the non-invasive continuous sphygmomanometer according to the second embodiment of the present invention is the same as the block diagram shown in FIG. FIG. 5 is a flowchart illustrating a processing procedure according to the second embodiment of this invention. It comprises an optimum waveform determination step of step 61 and a blood pressure measurement step of step 62.

The MPU 6 first generates an excitation rectangular wave having a frequency f. The excitation rectangular wave generated by the MPU 6 is
The signal is DA-converted by the AD / DA converter 5 and amplified by the amplifier 4. The vibrator 2 induces the excited rectangular wave amplified by the amplifier 4 on the blood vessel. The vibration at this time is measured by the vibrator sensor 1, amplified by the amplifier 4, AD-converted by the AD / DA converter 5, and input to the MPU 6.

The propagating wave sensor 3 measures the vibration induced by the vibrator 2 and propagating through the blood vessel wall. The vibration measured by the propagation wave sensor 3 is amplified by the amplifier 4 and AD-converted by the AD / DA converter 5,
Is input to the vibration signal W ₁ as MPU 6. This operation is performed continuously for T seconds. Next, the MPU 6 generates an excitation triangular wave of the frequency f, and the vibration signal W ₂ measured by the propagation wave sensor 3 is input to the MPU 6 through the same process as that of the rectangular wave. Similarly, the above-described process is executed for an arbitrary number of excitation waveforms such as a sawtooth waveform, and the MPU 6 sends a vibration signal W _i (i = 1, 2,.
., N) is input. MPU6 based on the exciter signal and the vibration signal W _i of the sensor 1, from the vibration waveform, determines the most appropriate vibration waveform in the measurement of the blood pressure of the subject. M
The PU 6 vibrates the vibrator 2 with the obtained optimal vibration waveform to induce vibration in the blood vessel, and the absolute values of the systolic blood pressure and the diastolic blood pressure output from the calibration sphygmomanometer 7;
From the input of the vibration signal detected by the propagation wave sensor 3, a continuous blood pressure is calculated by the method described in Japanese Patent Application Publication No. 9-506024. The calculated continuous blood pressure value is output to the monitor 8 as a time-series waveform. The monitor 8 also displays the maximum and minimum blood pressure and heart rate for each heartbeat.

As shown in FIG. 5, according to the second embodiment of the present invention, the optimal waveform
62 blood pressure measurement steps. The procedure of the optimum excitation waveform determination step executed by the MPU 6 is the same as that in FIG.

As described above, in the second embodiment of the present invention, the non-invasive continuous sphygmomanometer uses a plurality of different excitation waveforms to vibrate an artery in a living body from the body surface, Vibration detecting means for converting the vibration transmitted on the artery given by the vibration means into an electric signal, a calibration sphygmomanometer for measuring absolute values of systolic blood pressure and diastolic blood pressure, and a vibration signal detected by the vibration detecting means. Means for calculating a relative change in blood pressure value from a phase change, and blood pressure calculating means for continuously calculating in-vivo blood pressure based on the calculated change in relative blood pressure value and a measurement value from a calibration sphygmomanometer With respect to a vibration wave having each excitation waveform used when inducing vibration in a blood vessel, a circular arc estimation is performed from a phase change and a amplitude change of a vibration signal detected by a vibration detection unit, and an amplitude attenuation rate, a circle Since the excitation waveform having the smallest variation rate of the radius is determined as the optimal excitation waveform, an excitation waveform more suitable for each subject is determined, thereby achieving high reliability and high reliability. Accuracy can be realized.

[0047]

As described above, according to the present invention, by oscillating an artery in a living body from the body surface using a plurality of different excitation frequencies and excitation waveforms, it is most suitable for measuring the blood pressure of each subject. By determining a suitable excitation frequency and excitation waveform, the effect of improving the measurement accuracy and reliability of the non-invasive continuous blood pressure monitor can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of a first embodiment of the present invention;

FIG. 2 is a flowchart for explaining the operation of the first embodiment of the present invention;

FIG. 3 is a flowchart showing a procedure of an optimum excitation frequency determination program according to the first embodiment of the present invention;

FIG. 4 is a diagram showing an arc formed on an IQ plane by an I component and a Q component corresponding to a phase change of an excitation waveform;

FIG. 5 is a flowchart illustrating the operation of the second exemplary embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Exciter sensor 2 Exciter 3 Propagation wave sensor 4 Amplifier 5 AD / DA converter 6 MPU 7 Calibration blood pressure monitor 8 Monitor 51 Optimal frequency determination step 52 Blood pressure measurement step 61 Optimal waveform determination step 62 Blood pressure measurement step 101 Filter processing step 102 Quadrature detection step 103 Arc center estimation step 104 Arc radius dispersion value, attenuation rate calculation step 105 Optimal frequency calculation step

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[Procedure amendment]

[Submission date] April 12, 1999

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[ Title of the Invention] Non-invasive continuous blood pressure monitor

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-invasive continuous sphygmomanometer, and more particularly, to applying a weak vibration to a blood vessel in a living body, detecting and analyzing the vibration propagated in the blood vessel, and continuously analyzing the blood pressure. It relates to a non-invasive continuous sphygmomanometer for measuring.

[0002]

2. Description of the Related Art As a method for non-invasively and continuously measuring blood pressure, a method disclosed in Japanese Patent Publication No. 9-506024 is known. This is based on the fact that the elasticity of a blood vessel changes in response to a change in blood pressure. By detecting the propagation speed of a signal in the blood vessel, the elasticity of the blood vessel is calculated, and the blood pressure is estimated from the elasticity of the blood vessel. Things. The outline of the processing is as follows. The blood vessel is vibrated from the body surface of the subject, and the vibration propagated on the blood vessel is detected. After converting the detected vibration into a digital signal, filtering processing and phase detection processing are performed, a phase change due to blood pressure fluctuation is calculated, and a change in vibration propagation velocity is obtained. The change in vibration propagation velocity indicates a change in blood vessel elasticity, and the change in blood vessel elasticity indicates a change in blood pressure, that is, a dynamic pressure. This change is calibrated with the measured values of the systolic blood pressure and the diastolic blood pressure by a calibration sphygmomanometer separately installed on the same subject, so that the blood pressure in the living body is measured non-invasively and continuously. The measured blood pressure waveform is displayed along with the electrocardiogram, the respiration curve, and the biological information waveform of the oxygen saturation while being swept over time on the same monitor.

[0003]

In the invention disclosed in Japanese Patent Publication No. Hei 9-506024, the accuracy and reliability of the measured blood pressure value depend on the excitation frequency and the excitation waveform when oscillating the blood vessel. It depends greatly. Further, there is an individual difference in the frequency propagation characteristics of the blood vessels of the subject, and the optimum frequency and the optimum waveform cannot be determined in a unified manner.

[0004] Japanese Patent Publication No. 9-506024 discloses that the excitation frequency at the time of exciting the vibration of a blood vessel in a living body is arbitrary, and the excitation waveform is also a sine wave, a rectangular wave, a triangular wave or any other suitable waveform. It is described that any may be used.
However, there is no description about means for determining an optimal excitation frequency and an excitation waveform for each subject.

The present invention is directed to inducing vibration on a vessel wall.
Te, by using the vibration of multiple waveforms, for each subject, to determine a more suitable vibration frequency and vibration waveform, thereby, non-invasive continuous blood pressure reliable and accurate The purpose is to realize the total.

[0006]

In order to solve the above problems BRIEF SUMMARY OF THE INVENTION In the present invention, a means for vibrating the artery in a living body from the body by using a plurality of different name Ru vibration waveform, given by vibration means Vibration detecting means for converting the vibration propagated over the artery into an electrical signal, a calibration sphygmomanometer for measuring the absolute values of systolic blood pressure and diastolic blood pressure, and a relative change from the phase change of the vibration signal detected by the vibration detecting means. Blood pressure calculating means for continuously calculating the blood pressure in the living body based on the calculated relative blood pressure value change and the measured value from the calibration sphygmomanometer; vibration wave having a respective vibration waveforms used in inducing vibrations from the phase change and amplitude change in the detected vibration signal by the vibration detecting means performs an arc estimation, the amplitude attenuation rate, arc radius of Optimize the most small have vibration waveform kinematic rate
Is obtained by configured to determine the vibration waveform.

[0007] With this configuration, a non-invasive continuous sphygmomanometer that determines a more suitable excitation waveform for each subject and thereby achieves high reliability and high accuracy can be obtained.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION
Vibration means for vibrating a blood vessel, vibration detection means for detecting vibration transmitted through the blood vessel, phase detection means for phase-detecting an electric signal from the vibration sensor, and processor means for analyzing the phase detection signal In a non-invasive continuous sphygmomanometer that measures the blood pressure of a human body continuously and non-invasively by measuring the propagation speed of vibration, a plurality of different excitation devices are used by the vibration means before the blood pressure measurement of the subject. Means for vibrating a blood vessel with a vibration waveform, means for detecting vibration in each of these vibration waveforms by the vibration detection means, and means for obtaining an optimal vibration waveform by analyzing an electric signal from the vibration detection means And a means for determining a vibration waveform of the vibration means as the optimum waveform. The non-invasive continuous sphygmomanometer has an operation of selecting a vibration signal having an optimum waveform and measuring a blood pressure. .

[0009] The invention described in claim 2 of the present invention is claim 1.
The non-invasive continuous sphygmomanometer according to the above, wherein the means for determining the optimal waveform has means for selecting a waveform that minimizes the variance of the amplitude of the excitation signal transmitted through the blood vessel, and the optimal variance is small. This has the effect of selecting an excitation signal having a simple waveform and measuring blood pressure.

The third aspect of the present invention is the first aspect of the present invention.
In the non-invasive continuous sphygmomanometer according to the above, the means for determining the optimal waveform has means for selecting a waveform that maximizes the phase shift of the excitation signal propagated through the blood vessel, and has a large phase shift. This has the effect of selecting an excitation signal having an optimal waveform and measuring blood pressure.

The fourth aspect of the present invention is the first aspect of the present invention.
In the non-invasive continuous sphygmomanometer according to the above, the means for determining the optimal waveform includes an attenuation of the excitation signal transmitted through the blood vessel, a dispersion of an amplitude of the excitation signal transmitted through the blood vessel, and an excitation signal transmitted through the blood vessel. Means for selecting a waveform that minimizes the evaluation function including any two or all of the phase shifts of the phase shift. It has the effect of measuring.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described in detail with reference to FIG.

(First Embodiment) In a first embodiment of the present invention, prior to measuring the blood pressure of a subject, a blood vessel is vibrated at a plurality of different vibration frequencies by vibrating means. Vibration at the excitation frequency is detected by the vibration detection means, and the optimal excitation frequency is determined by analyzing the electric signal from the vibration detection means, and the non-invasive continuous blood pressure with the excitation frequency of the excitation means being the optimal frequency It is total.

FIG. 1 is a block diagram showing a configuration of a non-invasive continuous blood pressure monitor according to a first embodiment of the present invention. In FIG. 1, the exciter sensor 1 is an ultrasonic sensor. The vibrator 2 is an ultrasonic vibrator. The propagation wave sensor 3 is an ultrasonic sensor. The amplifier 4 is an amplifier that amplifies driving ultrasonic waves and ultrasonic waves from the sensor. The AD / DA converter 5 is an AD converter for performing digital conversion and a DA converter for performing analog conversion. The MPU 6 is a processor that generates a waveform, determines an optimal frequency, and performs various arithmetic processing. The calibration sphygmomanometer 7 is a device that measures a reference blood pressure. The monitor 8 is a display device.

The MPU 6 firstly generates an excitation waveform As having a frequency f _1.
in (2πf ₁ t) is generated. The excitation waveform Asin (2πf ₁ t) generated by the MPU 6 is DA-converted by the AD / DA converter 5 and amplified by the amplifier 4. The vibrator 2 induces the excitation waveform Asin (2πf ₁ t) amplified by the amplifier 4 on the blood vessel. The vibration at this time is measured by the vibrator sensor 1, amplified by the amplifier 4, AD-converted by the AD / DA converter 5, and input to the MPU 6.

The propagation wave sensor 3 measures the vibration induced by the vibrator 2 and propagated on the blood vessel wall. The vibration measured by the propagation wave sensor 3 is amplified by the amplifier 4 and AD-converted by the AD / DA converter 5,
Is input to the vibration signal W ₁ as MPU 6. This operation is performed continuously for T seconds. Then, MPU6 generates vibration waveforms of frequency _{f 2 Asin (2πf 2 t)} , through the same process as when the frequency f _1, the vibration signals W ₂ measured by the propagating wave sensor 3, the MPU6 Is entered. _{Similarly, f 3, f 4, ···} , any number of vibration waveforms Asin having a frequency of _{f n (2πf i t) (} i =
The above process is executed for 1, 2,..., N), and the vibration signal W _i (i = 1, 2,.
n) is input. The MPU 6 determines the excitation frequencies f ₁ , f ₂ ,... Based on the signal of the vibration sensor 1 and the vibration signal W _i.
- from among the f _n, to determine the most appropriate excitation frequency for the measurement of the blood pressure of the subject. The MPU 6 vibrates the vibrator 2 at the obtained optimal vibration frequency to induce vibration in the blood vessel, and outputs absolute values of the systolic blood pressure and the diastolic blood pressure output from the calibration sphygmomanometer 7 and the propagation wave sensor. 3, the continuous blood pressure is calculated from the input of the vibration signal detected by the method described in Japanese Patent Application Publication No. 9-506024. The calculated continuous blood pressure value is output to the monitor 8 as a time-series waveform. The monitor 8 also displays the maximum and minimum blood pressure and heart rate for each heartbeat.

As shown in FIG. 2, the first embodiment of the present invention comprises a step 51 for deciding an optimum frequency and a step 52 for measuring a blood pressure. FIG.
9 shows a procedure of an optimal excitation frequency determining step executed by the PU 6.

In the vibration signal W ₁ input to the MPU 6, the excitation waveform component of the frequency f ₁ is separated from other components by the filtering process in step 101. In step 102, a phase change of the excitation waveform component obtained by the filtering is calculated by a method known as quadrature detection, and a real component (I component) and an imaginary component (Q component) of the phase change are calculated. Is output.

In step 103, as shown in FIG. 4, the center of an arc formed by the I and Q components of the phase change of the excitation waveform formed on the IQ plane is estimated. In step 104,
The center point of the circular arc determined in step 103 and each point (I ₁ ,
_{Q 1), (I 2,} Q 2), determined ..., the average value R _F1Ave of (I _n, the distance between Q _n) (arc _{radius) r 1, r 2, ···} , r n, The attenuation rate P _f1 of the amplitude (arc radius) with respect to the amplitude A _ex of the exciter waveform detected by the exciter sensor 1 is calculated by the following equation. P _f1 = 1 · (R _f1Ave / A _ex )

In step 104, r₁, R_Two, ...
・, R_nVariance R of_f1VarAlso ask. In the same way,
In step 104, the vibration signal W_Two, W_Three, ..., W_nFrom
P_f2, P _f3, ..., P_fn, And R_f1Var, R_f2Var,
..., R_fnVarIs calculated.

[0021] At step _105, P _f1, R f1Var calculated in step 104 (i = 1,2, ···, n) on the basis of the most suitable among the f _i in the measurement of the blood pressure of the subject Calculated vibration frequency. In step 105, first, the amplitude attenuation factor P _f1, P _f2, · · ·, and P _fn, arc radius variance value _R f1Var, R f2Var, ···, the standard deviation of _R fnVar P
_Std and R _Std are calculated. Next, using P _Std and R _Std , the optimum excitation frequency determination value Z _fi (i = 1, 2,...,
n) is obtained from the following equation. Z _fi = α · (P _fi / P _Std ) + β · (R _fiVar / R _Std )

[0022] At step 105, the Z _fi is minimized f _i, and outputs a most suitable excitation vibration frequency for the measurement of the blood pressure of the subject. Note that α and β are the respective judgment elements (P _fi
/ P _{St d)} (which is determined according to _R fiVar / R _Std) of importance, is the value for the weighting.

As described above, in the first embodiment of the present invention, the non-invasive continuous sphygmomanometer uses a plurality of different excitation frequencies to vibrate an artery in a living body from the body surface, Vibration detecting means for converting the vibration transmitted on the artery given by the vibration means into an electric signal, a calibration sphygmomanometer for measuring absolute values of systolic blood pressure and diastolic blood pressure, and a vibration signal detected by the vibration detecting means. Means for calculating a relative change in blood pressure value from a phase change, and blood pressure calculating means for continuously calculating in-vivo blood pressure based on the calculated change in relative blood pressure value and a measurement value from a calibration sphygmomanometer A circular arc is estimated from the phase change and the amplitude change of the vibration signal detected by the vibration detection means for the vibration waves having the respective excitation frequencies used when inducing the vibration in the blood vessel, and the amplitude attenuation rate Since it is configured as a circular arc radius of the variation rate is determined as the smallest vibration vibration optimum pressure frequency frequency, to determine a more suitable vibration frequency for each subject,
Thereby, high reliability and high accuracy can be realized.

(Second Embodiment) In a second embodiment of the present invention, prior to the measurement of the blood pressure of a subject, a blood vessel is vibrated by vibrating means having a plurality of different waveforms by vibrating means. Vibration in each of these excitation waveforms is detected by the vibration detection means, and the optimal excitation waveform is obtained by analyzing the electric signal from the vibration detection means, and the excitation waveform of the excitation means is set as the optimal waveform. It is a continuous sphygmomanometer.

The second embodiment of the present invention is different from the first embodiment in that a plurality of waveforms other than a sine wave, such as a rectangular wave and a triangular wave, are used to oscillate a blood vessel to provide an optimal vibration. This is the point that determines the vibration waveform.

The configuration of the non-invasive continuous sphygmomanometer according to the second embodiment of the present invention is the same as the block diagram shown in FIG. FIG. 5 is a flowchart illustrating a processing procedure according to the second embodiment of this invention. It comprises an optimum waveform determination step of step 61 and a blood pressure measurement step of step 62.

The MPU 6 first generates an excitation rectangular wave having a frequency f. The excitation rectangular wave generated by the MPU 6 is
The signal is DA-converted by the AD / DA converter 5 and amplified by the amplifier 4. The vibrator 2 induces the excited rectangular wave amplified by the amplifier 4 on the blood vessel. The vibration at this time is measured by the vibrator sensor 1, amplified by the amplifier 4, AD-converted by the AD / DA converter 5, and input to the MPU 6.

The propagation wave sensor 3 measures the vibration induced by the vibrator 2 and propagating through the blood vessel wall. The vibration measured by the propagation wave sensor 3 is amplified by the amplifier 4 and AD-converted by the AD / DA converter 5,
Is input to the vibration signal W ₁ as MPU 6. This operation is performed continuously for T seconds. Next, the MPU 6 generates an excitation triangular wave of the frequency f, and the vibration signal W ₂ measured by the propagation wave sensor 3 is input to the MPU 6 through the same process as that of the rectangular wave. Similarly, the above-described process is executed for an arbitrary number of excitation waveforms such as a sawtooth waveform, and the MPU 6 sends a vibration signal W _i (i = 1, 2,.
., N) is input. MPU6 based on the exciter signal and the vibration signal W _i of the sensor 1, from the vibration waveform, determines the most appropriate vibration waveform in the measurement of the blood pressure of the subject. M
The PU 6 vibrates the vibrator 2 with the obtained optimal vibration waveform to induce vibration in the blood vessel, and the absolute values of the systolic blood pressure and the diastolic blood pressure output from the calibration sphygmomanometer 7;
From the input of the vibration signal detected by the propagation wave sensor 3, a continuous blood pressure is calculated by the method described in Japanese Patent Application Publication No. 9-506024. The calculated continuous blood pressure value is output to the monitor 8 as a time-series waveform. The monitor 8 also displays the maximum and minimum blood pressure and heart rate for each heartbeat.

As shown in FIG. 5, according to the second embodiment of the present invention, an optimum waveform
62 blood pressure measurement steps. The procedure of the optimum excitation waveform determination step executed by the MPU 6 is the same as that in FIG.

As described above, in the second embodiment of the present invention, the non-invasive continuous sphygmomanometer uses a plurality of different excitation waveforms to vibrate an artery in a living body from the body surface, Vibration detecting means for converting the vibration transmitted on the artery given by the vibration means into an electric signal, a calibration sphygmomanometer for measuring absolute values of systolic blood pressure and diastolic blood pressure, and a vibration signal detected by the vibration detecting means. Means for calculating a relative change in blood pressure value from a phase change, and blood pressure calculating means for continuously calculating in-vivo blood pressure based on the calculated change in relative blood pressure value and a measurement value from a calibration sphygmomanometer With respect to a vibration wave having each excitation waveform used when inducing vibration in a blood vessel, a circular arc estimation is performed from a phase change and a amplitude change of a vibration signal detected by a vibration detection unit, and an amplitude attenuation rate, a circle Since the excitation waveform having the smallest variation rate of the radius is determined as the optimal excitation waveform, an excitation waveform more suitable for each subject is determined, thereby achieving high reliability and high reliability. Accuracy can be realized.

[0031]

As described in the foregoing, in the present invention, by vibrating the artery in a living body from the body by using a plurality of different name Ru vibration waveform, most suitable pressure for the measurement of each subject blood pressure The effect of determining the vibration waveform and improving the measurement accuracy and reliability of the non-invasive continuous sphygmomanometer can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of a first embodiment of the present invention;

FIG. 2 is a flowchart for explaining the operation of the first embodiment of the present invention;

FIG. 3 is a flowchart showing a procedure of an optimum excitation frequency determination program according to the first embodiment of the present invention;

FIG. 4 is a diagram showing an arc formed on an IQ plane by an I component and a Q component corresponding to a phase change of an excitation waveform;

FIG. 5 is a flowchart illustrating the operation of the second exemplary embodiment of the present invention.

[Description of Signs] 1 Exciter sensor 2 Exciter 3 Propagation wave sensor 4 Amplifier 5 AD / DA converter 6 MPU 7 Calibration sphygmomanometer 8 Monitor 51 Optimal frequency determination step 52 Blood pressure measurement step 61 Optimal waveform determination step 62 Blood pressure measurement step 101 Filter processing step 102 Quadrature detection step 103 Arc center estimation step 104 Calculation of variance and attenuation rate of arc radius 105 Optimal frequency calculation step

Claims (20)

[Claims] 1. Vibration means for vibrating a blood vessel, vibration detection means for detecting vibration transmitted through a blood vessel, phase detection means for phase detecting an electric signal from a vibration sensor, and analyzing the phase detection signal. A non-invasive continuous sphygmomanometer which continuously and non-invasively measures the blood pressure of a human body by measuring a propagation speed of vibration, the processor comprising: Means for exciting the blood vessel at a plurality of different excitation frequencies, means for detecting the vibration at each of these excitation frequencies by the vibration detection means, and analysis of the electric signal from the vibration detection means for optimal excitation. A non-invasive continuous sphygmomanometer comprising: means for determining a vibration frequency; and means for determining a vibration frequency of the vibration means as the optimum frequency. 2. The non-invasive continuous sphygmomanometer according to claim 1, wherein the means for determining the optimum frequency includes means for selecting a frequency at which the attenuation of the excitation signal transmitted through the blood vessel is minimized. . 3. The non-invasive continuous system according to claim 1, wherein the means for determining the optimum frequency includes means for selecting a frequency at which the variance of the amplitude of the excitation signal transmitted through the blood vessel is minimized. Sphygmomanometer. 4. The non-invasive continuous system according to claim 1, wherein the means for determining the optimum frequency includes a means for selecting a frequency at which the phase shift of the excitation signal propagated through the blood vessel is maximized. Sphygmomanometer. 5. The means for determining the optimum frequency includes attenuating the excitation signal transmitted through the blood vessel, dispersing the amplitude of the excitation signal transmitted through the blood vessel, and calculating the phase shift of the excitation signal transmitted through the blood vessel. 2. The non-invasive continuous sphygmomanometer according to claim 1, further comprising means for selecting a frequency that minimizes an evaluation function including any two or all of them. 6. Vibrating means for vibrating a blood vessel, vibration detecting means for detecting vibration transmitted through a blood vessel, phase detecting means for phase detecting an electric signal from a vibration sensor, and analyzing the phase detected signal. A non-invasive continuous sphygmomanometer which continuously and non-invasively measures the blood pressure of a human body by measuring a propagation speed of vibration, the processor comprising: Means for exciting a blood vessel with a plurality of different excitation waveforms, means for detecting the vibration with each of the excitation waveforms by the vibration detection means, and analysis of the electric signal from the vibration detection means for optimal excitation. A non-invasive continuous sphygmomanometer comprising: means for obtaining a vibration waveform; and means for determining a vibration waveform of the vibration means as the optimum waveform. 7. The non-invasive continuous sphygmomanometer according to claim 6, wherein, with respect to the method of selecting the optimum waveform, a waveform that minimizes the attenuation of the excitation signal transmitted through the blood vessel is selected. How to improve. 8. The non-invasive continuous blood flow according to claim 6, wherein the means for determining the optimal waveform includes means for selecting a waveform that minimizes the variance of the amplitude of the excitation signal transmitted through the blood vessel. Sphygmomanometer. 9. The non-invasive continuous system according to claim 6, wherein the means for determining the optimum waveform includes means for selecting a waveform that maximizes the phase shift of the excitation signal propagated through the blood vessel. Sphygmomanometer. 10. The means for determining the optimum waveform includes attenuation of an excitation signal transmitted through a blood vessel, dispersion of an amplitude of the excitation signal transmitted through the blood vessel, and phase shift of the excitation signal transmitted through the blood vessel. 7. The non-invasive continuous sphygmomanometer according to claim 6, further comprising means for selecting a waveform that minimizes an evaluation function including any two or all of them. 11. A vibration means for vibrating a blood vessel,
A vibration detecting means for detecting vibration transmitted through the blood vessel, a phase detecting means for detecting a phase of an electric signal from the vibration sensor, and a processor for analyzing the phase detected signal; In the non-invasive continuous blood pressure measurement method for continuously and non-invasively measuring the blood pressure, prior to measuring the blood pressure of the subject, vibrating the blood vessels at a plurality of different vibration frequencies by the vibration means, The vibration at each excitation frequency is detected by the vibration detection means, and the optimal excitation frequency is obtained by analyzing the electric signal from the vibration detection means, and the excitation frequency of the excitation means is set to the optimal frequency. A non-invasive continuous blood pressure measurement method, characterized in that: 12. The method for selecting the optimum frequency,
The non-invasive continuous blood pressure measurement method according to claim 11, wherein a frequency at which the attenuation of the excitation signal transmitted through the blood vessel is minimized is selected. 13. The method for selecting the optimum frequency,
12. The non-invasive continuous blood pressure measurement method according to claim 11, wherein a frequency that minimizes the variance of the amplitude of the excitation signal transmitted through the blood vessel is selected. 14. The method for selecting the optimum frequency,
The non-invasive continuous blood pressure measurement method according to claim 11, wherein a frequency at which a phase shift of the excitation signal propagated through the blood vessel is maximized is selected. 15. The method for selecting the optimum frequency,
Minimize the evaluation function including any two or all of the attenuation of the excitation signal transmitted through the blood vessel, the dispersion of the amplitude of the excitation signal transmitted through the blood vessel, and the phase shift of the excitation signal transmitted through the blood vessel. The non-invasive continuous blood pressure measurement method according to claim 11, wherein a frequency to be measured is selected. 16. Vibration means for vibrating a blood vessel,
A vibration detecting means for detecting vibration transmitted through the blood vessel, a phase detecting means for detecting a phase of an electric signal from the vibration sensor, and a processor for analyzing the phase detected signal; In the non-invasive continuous blood pressure measurement method for continuously and non-invasively measuring the blood pressure, prior to the measurement of the blood pressure of the subject, vibrating the blood vessel with a plurality of different excitation waveforms by the excitation means, Vibration at each excitation waveform is detected by the vibration detection means, and an optimal excitation waveform is obtained by analyzing an electric signal from the vibration detection means,
A non-invasive continuous blood pressure measurement method, characterized in that a vibration waveform of the vibration means is the optimum waveform. 17. The non-invasive continuous blood pressure measurement method according to claim 16, wherein a waveform that minimizes attenuation of an excitation signal transmitted through a blood vessel is selected with respect to the method of selecting the optimal waveform. 18. The non-invasive continuous blood pressure measurement method according to claim 16, wherein a waveform that minimizes the variance of the amplitude of the excitation signal transmitted through the blood vessel is selected with respect to the method of selecting the optimal waveform. 19. The non-invasive continuous blood pressure measurement method according to claim 16, wherein a waveform that maximizes the phase shift of the excitation signal transmitted through the blood vessel is selected with respect to the method of selecting the optimal waveform. 20. The method for selecting an optimum waveform, the method comprising: attenuating an excitation signal transmitted through a blood vessel, dispersion of an amplitude of an excitation signal transmitted through a blood vessel, or phase shift of an excitation signal transmitted through a blood vessel. 17. The non-invasive continuous blood pressure measurement method according to claim 16, wherein a waveform that minimizes an evaluation function including at least two or all of them is selected.