JPH10295657A - Blood pressure measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a troublesome manipulation at measuring the blood pressure and enhance the easiness in handling the device by arranging it so that the blood pressure is calculated on the basis of the pulsation signal obtained through sensing, and therefore, only one sensor, a pulsation sensor, must be put on the body of a subject. SOLUTION: A blood pressure measuring device senses the pulsation generated by blood circulation in a human body using a pulsation sensing means 8, calculates the feature amount related to the blood pressure using a feature amount calculating means 11 on the basis of the pulsation signal obtained through sensing, and calculates the blood pressure using a blood pressure calculating means 18 on the basis of the obtained feature amount. According to this configuration where the blood pressure is determined on the basis of pulsation signals, only one sensor, a pulsation sensor, must be put on the body of a subject to lead to elimination of troublesomeness in manipulation at measuring the blood pressure and enhancement of the easiness in handling the device, and further because the blood pressure measurement is conducted through computation of the feature amount related to the blood pressure, accurate measurements can be obtained even with varying shape of pulsation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blood pressure measuring device, and more particularly to a low-restraint blood pressure measuring device for measuring blood pressure without using a cuff (compression band).

[0002]

2. Description of the Related Art A conventional low-restraint blood pressure measuring apparatus of this type is generally the one described in JP-A-8-140948. As shown in FIG. 25, the blood pressure measuring device includes cardiac potential electrodes 1 and 2, electrocardiographic processing means 3 for processing cardiac potential signals, fingertip photoelectric pulse wave sensor 4, pulse wave processing means 5 for processing pulse wave signals, Second-order differentiating means 6 for performing second-order differentiation of the pulse wave signal;
It comprises a calculating means 7 for calculating the blood pressure based on the next differential signal, and a display means 8 for displaying the calculation result. The cardiac potential electrodes 1 and 2 and the fingertip photoelectric pulse wave sensor 4 are attached to each part of the human body as shown in FIG.

[0003] As shown in FIG.
Calculates the pulse wave transit time PTT, the pulse wave interval PI, and the heart rate HR (= 1 / PI) from the cardiac potential waveform and the pulse wave waveform, as well as the positive first wave height x and negative of the second derivative waveform of the pulse wave. The ratio y / x of the first wave height y in the direction or the time difference Tb between the positive first peak and the positive second peak of the pulse wave is obtained as a vascular property parameter TP, and the blood pressure value (systolic blood pressure) is calculated based on the equation (1). (SYS), diastolic blood pressure (DIA)).

SYS, DIA = c1 * HR + c2 * PTT + c3 * TP + c4 Equation (1) where c1, c2, c3, and c4 are constants obtained statistically, and are different between SYS and DIA.

[0005]

However, in the above-mentioned conventional blood pressure measuring device, the pulse wave transit time has to be obtained in order to calculate the blood pressure. Therefore, as shown in FIG. The sensor has to be worn on the human body, and there is a problem in use. Especially for the cardiac potential electrodes, in order to accurately detect the cardiac potential, it is usually necessary to attach a conductive paste to the human body and attach an electrode plate for measuring the cardiac potential, which makes the operation for blood pressure measurement complicated. And there was a problem that usability was poor.

Further, as a parameter TP, a ratio y / of the positive first wave height x and the negative first wave height y of the second derivative waveform of the pulse wave is used.
The blood pressure is calculated using x or the time difference Tb between the positive first peak and the positive second peak of the pulse wave. For example, when hypertension or arteriosclerosis occurs, the pulse wave shape changes. There is a problem in that Tb cannot be obtained accurately, and blood pressure cannot be calculated correctly, because only a portion may appear.

[0007]

According to the present invention, in order to solve the above-mentioned problems, a pulse wave detecting means detects a pulse wave generated by blood circulation of a human body, and a characteristic value calculating means detects a blood pressure based on the detected pulse wave signal. The related feature value is calculated, and the blood pressure calculating means calculates the blood pressure based on the calculated feature value.

According to the above invention, since the blood pressure is calculated based on the detected pulse wave signal, only a pulse wave sensor needs to be worn on the human body, and the operation for measuring the blood pressure is not complicated, and the usability is improved. At the same time, since the blood pressure is measured by calculating a characteristic amount related to the blood pressure, the blood pressure can be accurately measured even if the pulse wave shape changes.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A blood pressure measuring apparatus according to a first aspect of the present invention includes a pulse wave detecting means for detecting a pulse wave generated by blood circulation in a human body, and a pulse wave signal output from the pulse wave detecting means. And a blood pressure calculating means for calculating a blood pressure based on a characteristic amount signal output from the characteristic amount calculating means.

[0010] Then, since a characteristic amount related to blood pressure is calculated from the detected pulse wave signal and the blood pressure is calculated based on the calculated characteristic amount, only a pulse wave sensor needs to be worn on the human body. Operational complexity is eliminated, continuous measurement for a long time is possible, and usability can be improved.In addition, since the blood pressure is measured by calculating the characteristic amount related to the blood pressure, the blood pressure can be accurately measured even if the pulse wave shape changes. The blood pressure measurement device according to claim 2 of the present invention includes a pulse wave correction unit for calculating a pulse wave interval by the pulse wave detecting means and correcting a pulse wave signal at the pulse wave interval.

Since the pulse wave correction unit corrects the pulse wave signal at pulse wave intervals, the blood pressure can be measured accurately regardless of the magnitude of the pulse.

According to a third aspect of the present invention, in the blood pressure measurement device, the characteristic amount calculating means may calculate each of the pulse heights of the pulse wave signal output from the pulse wave detecting means, the ratio of each of the pulse heights, and the pulse wave onset point. A pulse wave feature value calculation unit that calculates at least one of the time up to, the time interval between the waves, the integrated value of the pulse wave, and the pulse rate as the pulse wave feature value.

The pulse wave feature quantity calculation unit calculates each pulse height of the pulse wave signal, a ratio of each pulse height, a time from a pulse wave rising point to each wave, a time interval between the respective waves, an integral value of the pulse wave, Since at least one of the pulse rates is calculated as a pulse wave feature, and the blood pressure calculation means calculates the blood pressure based on the pulse wave feature, the blood pressure can be accurately measured even if the blood pressure changes due to high blood pressure or arteriosclerosis. it can.

According to a fourth aspect of the present invention, there is provided a blood pressure measuring apparatus, wherein the characteristic amount calculating means calculates a velocity pulse wave which is a first derivative of the pulse wave based on the pulse wave signal outputted from the pulse wave detecting means. Wave calculating unit, each wave height of the speed pulse wave signal output from the speed pulse wave calculating unit, the ratio of each wave height, the time from the rising point of the speed pulse wave to each wave, the time interval between each wave A speed pulse wave feature value calculation unit that calculates at least one of the zero pulse intervals of the speed pulse wave as a speed pulse wave feature value.

The speed pulse wave calculating section calculates a speed pulse wave, which is a first derivative of the pulse wave, and the speed pulse wave feature quantity calculating section calculates each of the wave heights of the speed pulse wave signal, the ratio of the wave heights, and the speed pulse wave. Time from the wave rising point to each wave, time interval between each wave,
At least one of the zero-cross intervals of the velocity pulse wave is calculated as a velocity pulse wave characteristic amount, and the blood pressure computation means computes the blood pressure based on the velocity pulse wave characteristic amount. Even with this, blood pressure can be accurately measured.

According to a fifth aspect of the present invention, there is provided a blood pressure measuring device, wherein the characteristic amount calculating means calculates an acceleration pulse wave which is a second derivative of the pulse wave based on the pulse wave signal output from the pulse wave detecting means. A wave calculating unit, and an acceleration for calculating at least one of each wave height of the acceleration pulse wave signal output from the acceleration pulse wave calculating unit, a ratio of the wave heights, and a time interval between the waves as an acceleration pulse wave feature amount. It has a pulse wave feature value calculation unit.

An acceleration pulse wave calculating section calculates an acceleration pulse wave which is a second derivative of the pulse wave based on the pulse wave signal output from the pulse wave detecting means. Each of the wave heights, the ratio of the wave heights, and at least one of the time intervals between the waves are calculated as the acceleration pulse wave feature amount, and the blood pressure calculation means calculates the blood pressure based on the acceleration pulse wave feature amount. Blood pressure can be accurately measured even if the pulse wave shape changes due to arteriosclerosis.

According to a sixth aspect of the present invention, in the blood pressure measuring device, the pulse wave detecting means has a plurality of pulse wave detecting sections for detecting pulse waves at different parts of the human body, and the characteristic value calculating means includes the pulse wave detecting means. A pulse wave feature calculating unit that calculates at least one of a pulse wave propagation time and a pulse wave propagation speed as a pulse wave feature based on the pulse wave signal from the detection unit.

A pulse wave detecting unit detects pulse waves at different parts of the human body, and a pulse wave characteristic calculating unit calculates at least one of the pulse wave propagation time and the pulse wave propagation speed based on the pulse wave signal. The calculation is performed as the propagation characteristic amount, and the blood pressure calculation means calculates the blood pressure based on the pulse wave propagation characteristic amount, so that the pulse wave propagation characteristic amount can be calculated without the complicated mounting like the cardiac potential electrode, and the usability is improved. In addition, the blood pressure can be accurately measured even if the pulse wave shape changes due to high blood pressure or arteriosclerosis.

The blood pressure measuring device according to claim 7 of the present invention has a body characteristic amount input unit capable of inputting at least one of the height, weight, sex, and age of a human body as a body characteristic amount.

Since the blood pressure calculating means calculates the blood pressure based on the body characteristic amount input to the body characteristic amount input section, the practicality can be improved and the blood pressure can be measured with high accuracy.

In the blood pressure measuring device according to claim 8 of the present invention, the blood pressure calculating means includes at least one of a pulse wave feature, a velocity pulse wave feature, an acceleration pulse wave feature, a pulse wave propagation feature, and a body feature. Calculate the blood pressure based on

The blood pressure calculating means calculates the blood pressure based on at least one of the pulse wave characteristic amount, the velocity pulse wave characteristic amount, the acceleration pulse wave characteristic amount, the pulse wave propagation characteristic amount, and the body characteristic amount. , The blood pressure can be measured accurately even if the pulse wave shape changes.

According to a ninth aspect of the present invention, there is provided a blood pressure measuring device, wherein the blood pressure calculating means has a reference value input unit capable of inputting a reference value of blood pressure.
The relationship between at least one of the acceleration pulse wave feature, the pulse wave propagation feature, and the body feature and the blood pressure to be calculated can be corrected.

The relationship between at least one of the pulse wave characteristic amount, the velocity pulse wave characteristic amount, the acceleration pulse wave characteristic amount, the pulse wave propagation characteristic amount, and the body characteristic amount and the calculated blood pressure can be corrected by the input reference value. For example, it is possible to cope with a change in the user's blood circulation dynamics or a change in the user due to aging, change in constitution, exercise, change in body position, etc. Can be measured.

According to a tenth aspect of the present invention, in the blood pressure measurement device, the blood pressure value calculating means uses the reference value of the blood pressure as a teacher signal, and calculates a pulse wave characteristic amount, a velocity pulse wave characteristic amount, an acceleration pulse wave characteristic amount, and a pulse wave propagation. The relationship between at least one of the feature amount and the body feature amount and the calculated blood pressure is learned.

The relationship between the feature value information obtained from the feature value signal from the feature value calculating means and the blood pressure reference value signal from the reference value input unit is gradually learned on site, and finally the reference value is input. Since the blood pressure corresponding to the characteristic amount information from the characteristic amount calculating means is output without the correction by the above, the accuracy of the blood pressure measurement is improved.

[0028] In the blood pressure measuring device according to claim 11 of the present invention, the pulse wave detecting means may include a fingertip of a hand, an earlobe, a fingertip of a foot, an upper arm,
It can be attached to at least one site of the wrist, neck, and chest, and detects a pulse wave at the site.

Since the pulse wave can be easily detected at any part by the pulse wave detecting means, the usability can be improved.

[0030] In a blood pressure measuring apparatus according to a twelfth aspect of the present invention, the pulse wave detecting means detects a pulse wave from a fingertip of a hand, and is adjacent to the first pulse wave detecting unit. A second pulse wave detector that is installed and detects a pulse wave from a part other than the fingertip.

Since the first pulse wave detecting section and the second pulse wave detecting section are adjacent to each other, the size can be reduced and the apparatus is portable.

According to a thirteenth aspect of the present invention, there is provided a blood pressure measuring device, wherein the first pulse wave detecting section and the second pulse wave detecting section each detect a pulse wave by a photoelectric pulse wave method and a light receiving section. And both light emitting units are shared.

Since both light-emitting portions are shared, the number of components can be reduced and the practicability is high. Claim 1 of the present invention
The blood pressure measurement device according to 4 includes a pressure sensor in which the second pulse wave detector detects a pulse pressure.

Since the pressure pulse wave is detected from the neck and chest and the pulse wave can be detected at a position close to the heart, the calculation accuracy of the pulse wave propagation time and the pulse wave propagation speed can be improved.

In a blood pressure measuring device according to a fifteenth aspect of the present invention, the second pulse wave detector comprises a microphone for detecting a heart sound.

Since the vibration and heart sound due to the heartbeat are detected, the calculation accuracy of the pulse wave propagation time and pulse wave propagation speed can be improved.

The blood pressure measurement device according to claim 16 of the present invention has a storage unit for storing the blood pressure calculated by the blood pressure value calculation means.

Since the stored value can be reproduced at any time by the blood pressure calculating means, the trend of the judgment value from the past and the like can be understood and the usability is good.

A blood pressure measuring device according to a seventeenth aspect of the present invention has a display unit for displaying the blood pressure calculated by the blood pressure value calculating means.

In addition, real-time display and stored past data can be displayed at any time, so that it is convenient.

The blood pressure measurement device according to the eighteenth aspect of the present invention has an alarm generation unit that generates an alarm when the blood pressure calculated by the blood pressure value calculation means deviates from a preset normal range.

When the calculated blood pressure deviates from the normal range, the alarm generation unit generates an alarm, so that it is possible to check, for example, abnormalities in the body while sleeping or working, which is useful for health management.

The blood pressure measuring device according to the nineteenth aspect of the present invention has a communication terminal for the blood pressure value calculating means to communicate with an external medium.

Since communication with an external medium is performed through the communication terminal unit, intensive health management and necessary information can be updated on the external medium, and usability can be improved.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. (Embodiment 1) FIG. 1 is a block diagram of a blood pressure measuring apparatus according to Embodiment 1 of the present invention, and FIG. 2 is an external view of the apparatus. In this embodiment, the blood pressure is measured at the fingertip. In FIG. 1, reference numeral 8 denotes pulse wave detecting means for detecting a pulse wave at a fingertip generated by blood circulation of a human body. The pulse wave detecting unit 9 is of a photoelectric type and a pulse wave signal is output from a pulse wave signal output from the pulse wave detecting unit 9. A pulse wave correction unit 10 that calculates a wave interval and corrects a pulse wave signal at a pulse wave interval.
have. Reference numeral 11 denotes a feature value calculating unit that calculates a feature value related to blood pressure based on the pulse wave signal output from the pulse wave detecting unit 8, and a pulse wave feature value calculating unit 12 that calculates a pulse wave feature value from the pulse wave signal itself. A speed pulse wave calculating unit 13 for calculating a speed pulse wave which is a first derivative of the pulse wave signal; a speed pulse wave feature amount calculating unit 14 for calculating a speed pulse wave feature amount from the speed pulse wave; An acceleration pulse wave calculator 15 for calculating an acceleration pulse wave as a derivative, an acceleration pulse wave feature calculator 16 for calculating an acceleration pulse wave feature from an acceleration pulse wave, and a body feature input unit 17 capable of inputting a body feature. have. Reference numeral 18 denotes a blood pressure calculation unit that calculates a blood pressure based on the characteristic amount signal output from the characteristic amount calculation unit 11, and includes a pulse wave characteristic amount, a velocity pulse wave characteristic amount, an acceleration pulse wave characteristic amount, a pulse wave propagation characteristic amount, and a body characteristic. Blood pressure calculation unit 1 that calculates blood pressure based on at least one of the amounts
9, a reference value input unit 20 capable of inputting a reference value of blood pressure, a storage unit 21 for storing the calculated blood pressure, a display unit 22 for displaying the calculated blood pressure, and the calculated blood pressure is preset. It has an alarm generation unit 23 that generates an alarm when it deviates from the normal range.

In FIG. 2, reference numeral 24 denotes a main body of the blood pressure measuring apparatus according to the present embodiment, and the main body 24 comprises the pulse wave detecting means 8 and the signal processing unit 25. The pulse wave detecting means 8 and the signal processing unit 25 are connected by a connecting portion 26 which can be flexibly extended and contracted so as to correspond to the dimensions of the finger when the main body is attached to the finger and the flexion of the finger joint. Reference numeral 27 denotes an insertion portion for inserting a fingertip when measuring a finger pulse wave, which has an expansion and contraction portion 28 which can expand and contract according to the thickness of the finger, and is designed so that the first joint of the finger can be sufficiently inserted. Have been. Insertion part 2
A first light emitting unit 29 and a first light receiving unit 30 as the pulse wave detecting unit 9 are mounted on 7. The first light emitting section 29 and the first
Although the light receiving section 30 of the type generally used when measuring a photoelectric volume pulse wave is used, a light emitting diode and a phototransistor may be used, or the first light emitting section 2 may be preferably used.
Reference numeral 9 denotes 5000 to 8000, which is the absorption band of hemoglobin.
A lamp having a wavelength of Angstroms is used, and a selenium sulfide cadmium photoelectric tube element is used for the first light receiving section 30. The insertion portion 27 may be configured to be foldable by using, for example, the expansion and contraction portion 28. In the above description, the first light emitting unit 29 and the first light receiving unit 30 face each other, and the pulse wave is detected based on the amount of light transmitted through the inserted fingertip. A configuration may also be adopted in which a pulse wave is detected by detecting reflected light from a fingertip inserted with the fingertip and the first light receiving unit 30 adjacent to each other. The signal processing unit 25 has the feature value calculation means 11 and the blood pressure calculation means 18, and the body feature value input unit 17, the reference value input unit 20, the display unit 22, and the alarm generation unit 23 are installed on the surface. Reference numeral 31 denotes a communication terminal unit for performing communication between the main body 24 and an external medium. The main body 24 is driven using a battery built in the main body as a power source, but power may be supplied from the outside via a terminal of the communication terminal portion 31.

Next, the operation and operation will be described. The fingertip is inserted into the insertion section 27, and the main body 24 is attached to the fingertip of the hand as shown in FIG. FIG. 4 is a flowchart at the time of blood pressure measurement. First, a pulse wave is detected in ST1. Here, the pulse wave detector 9 (the first light emitting unit 29 and the first light receiving unit 30) detects a fingertip pulse wave. The general shape of the detected pulse wave is shown in FIGS. 5 (a) and 6 (b). FIG. 5A shows a pulse waveform called a post-normal ridge which is mainly observed in a young person with normal blood pressure. FIG. 6A shows a pulse wave waveform called a prominent ridge which is seen in hypertensive and elderly people. The pulse wave signal detected by the pulse wave detection unit 9 may cause the base line to sway due to movement of the body or the like. Therefore, the pulse wave correction unit 10 extracts a plurality of pulse wave waveforms for each beat from the pulse wave signal. The baseline is adjusted and averaged to obtain an average pulse waveform. Then, based on this waveform, the pulse wave correction unit 10 determines the pulse wave interval Pi as needed (ST2), and corrects the time axis of the original pulse wave waveform. (S
T3) This is because there is an individual difference in the pulse rate, and it is necessary to correct the individual difference in the temporal element of the characteristic amount of the pulse waveform described later. As the correction equation, for example, the equation of Bazzet (Bazzet, H, C., 1920) shown in (Equation 1) is used.

[0048]

(Equation 1)

Next, in ST4, the characteristic amount calculating means 11 calculates the characteristic amount based on the pulse wave signal from the pulse wave correcting section 10. A method for obtaining the feature amount will be described with reference to FIGS. 5 and 6, (b) shows a waveform of a velocity pulse wave obtained by first-order differentiation of the pulse wave, which is computed by the velocity pulse wave computing unit 13. (C) is a waveform of the acceleration pulse wave obtained by secondarily differentiating the pulse wave, and is an acceleration pulse wave calculating unit 1.
5 is calculated. In FIGS. 5A and 6A, S
Is the rising point of the pulse wave, P is the peak of systole, T is the tidal wave, C is the notch, D is the relaxation peak, and A is the anterior ridge.

In the pulse wave feature quantity calculating section 12, P is obtained as the maximum point of the waveform. Fig. 5 for T, C and D
In (a), since it appears as a clear peak, it can be obtained as the zero cross point of the velocity pulse wave. FIG.
When A, C, and D do not appear as clear peaks as in (a), A, C, and D are obtained as shown in FIG. First, for A, a perpendicular l1 from the zero cross point of the acceleration pulse wave,
l2 is subtracted, and intersection points p1 and p2 between l1 and l2 and the pulse wave curve are obtained.
At, tangent lines l3 and l4 are drawn. When subtracting l2 here,
As shown in FIG. 7C, when there is no zero cross point near the point pc of the acceleration pulse wave, l2 is subtracted from the maximum point pγ. Then, a perpendicular 15 is drawn from the intersection p3 of l3 and l4 to the base line,
Let A be the intersection of 15 with the pulse wave curve. For C, perpendicular lines 16 and 17 are drawn from the zero cross point of the acceleration pulse wave, and l
At the intersections p4 and p5 of the pulse wave curve with the ligature l
Subtract 8,19. Then, a perpendicular 110 is drawn from the intersection p6 of l8 and l9 to the base line, and the intersection of l10 and the pulse wave curve is defined as C. For D, a perpendicular line l11 is drawn from the zero cross point of the acceleration pulse wave, and a tangent line l12 is drawn at the intersection p7 of the pulse wave curve with l11. Then, a perpendicular line l13 is drawn from the intersection p8 of l9 and l12 to the base line, and the intersection of l13 and the pulse wave curve is set to D. Although P, T, C, D, and A are obtained in this manner, they may be obtained using a technique such as waveform pattern recognition. In the pulse wave feature value calculation unit 12, P,
After obtaining T, C, D, and A, the wave heights of P, T, C, D, and A, the ratio of the wave heights, the time from the rising edge of the pulse wave to the waves, and the time interval between the waves , And at least one of an integrated value of a pulse wave and a pulse rate. For example, FIG.
(A), as shown in FIG. 6 (a), the amplitude of P, T, C, and D is α, β, γ,
δ, the amplitudes of A, P, C, and D are α, β, γ, and δ, respectively, and the maximum wave height is H (α for a normal rear ridge, β for a front ridge). Ask. Α / β is determined as EI and γ / H is determined as DI as the wave height ratio. S to P and S to C are obtained as Tu and Te, respectively, as the time from the pulse wave rising point to each wave. The time interval between each wave is P
To C are Tr, the integrated value of the pulse wave is Isp, and the pulse rate 60 / Pi is HR. The rising point S of the pulse wave is obtained as an intersection S 'between the tangent line 13 and the base line as shown in FIG.
("Base point side"), and A and C may be defined as a branch point between the pulse wave curve and the tangent line 13 (systole king P side) and a branch point with the tangent line 18 (base line side), respectively. You may ask.

The velocity pulse wave feature quantity calculating section 12 calculates each pulse height of the velocity pulse wave signal output from the velocity pulse wave computing section 13, the ratio of each pulse height, the time from the rising point of the velocity pulse wave to each wave, At least one of a time interval between the waves and a zero-cross interval of the velocity pulse wave is calculated as a velocity pulse wave feature value. Among them, for example, as shown in FIGS. 5 (b) and 6 (b), the maximum wave height v of the velocity pulse wave is obtained as the wave height, and the period Tu in which the velocity pulse wave is positive is obtained as the time interval between the waves. .

The acceleration pulse wave feature quantity calculation unit 16 calculates the pulse height of the acceleration pulse wave signal output from the acceleration pulse wave calculation unit 15,
At least one of the ratio of the wave heights and the time interval between the waves is calculated as an acceleration pulse wave feature value. Among them, for example, as shown in FIGS. 5C and 6C, the amplitudes a, b, c, d, and e of the maximum point and the minimum point of the waveform are obtained. Here, a, b, c, d, and e are positive values when the local maximum points and local minimum points are above the base line, and negative values when the local points are below the base line. The ratio of each wave height is b / a, c / a, d /
a, e / a are calculated, and Rb, Rc, Rd, Re
And

It is possible to input at least one of the user's height, weight, sex, and age from the body characteristic amount input section 17 as necessary.

The feature value calculating means 11 calculates the feature value related to the blood pressure as described above.
Or calculate the other index not shown above, such as obtaining the time from the rise of the waveform to the amplitude c in the acceleration pulse wave, or further calculate the higher-order differential waveform, each wave height, of each of the wave height At least one of the ratio and each of the wave intervals may be calculated as a feature amount.

In ST5, the blood pressure calculating means 18 calculates the blood pressure from the preset judgment line. The determination line and the calculation procedure will be described with reference to FIGS. FIG. 8 shows the determination lines L1 and L2 when the blood pressure BP is calculated using EI and DI as the feature amounts. Here, L1 is for maximal blood pressure, and L2 is for diastolic blood pressure. The EI is related to the elasticity of the arterial vascular wall, and the smaller the EI, the higher the blood pressure tends to be. DI is related to the caliber of the arterial tract, that is, the degree of arterial tract tension, and the larger the DI, the higher the blood pressure tends to be.
The blood pressure calculation unit 19 calculates the systolic blood pressure BP1 and the diastolic blood pressure BP2 from EI0 and DI based on FIG. FIG. 9 shows the determination lines L3 and L4 when the blood pressure BP is calculated using Tu and Te as the feature amounts. Where L3
Is for maximal blood pressure and L4 is for diastolic blood pressure. Tu is related to the time required for the systolic force to reach the maximum value after the aortic valve is opened, and when Tu is large, the blood pressure tends to increase. Also T
e is related to the time during which the aortic valve is open, and when Te is large, the blood pressure tends to increase. The blood pressure calculation unit 19 calculates the systolic blood pressure BP3 and the diastolic blood pressure BP4 from Tu0 and Te based on FIG. FIG. 10 shows Tu0 and v
Determination lines L5, L5 when calculating blood pressure BP using
6 is shown. Where L5 is for maximal blood pressure, L6
Is for diastolic blood pressure. In addition to the above, Tu is related to the magnitude of vascular resistance because the pulse wave velocity is positive and the time is short when blood is smoothly pumped to the periphery. As described above, blood pressure increases when Tu is large as described above. There is a tendency. v is related to the rising speed of the pulse wave, and when v is small, the blood pressure tends to increase. The blood pressure calculator 19 calculates Tu0 based on FIG.
And v, a systolic blood pressure BP5 and a diastolic blood pressure BP6 are calculated. FIG. 11 shows a blood pressure BP using Rb and Rd as feature amounts.
Are judgment lines L7 and L8 in the case of calculating. Here, L7 is for maximum blood pressure and L8 is for minimum blood pressure. Rb is related to the cardiac output, and the smaller the negative value of Rb, the higher the blood pressure tends to be. Rd is related to the magnitude of the burden on the heart, and a large negative value of Rd tends to increase blood pressure. The blood pressure calculation unit 19 calculates a systolic blood pressure BP7 and a diastolic blood pressure BP8 from Rb and Rd based on FIG. FIG. 12 shows the blood pressure B using EI0 and age as the feature amounts.
FIG. 9 shows determination lines L9 and L10 when P is calculated. Here, L9 is for maximum blood pressure, and L10 is for minimum blood pressure. The EI is as described above, and the blood pressure tends to increase as the age increases. FIG.
Based on EI0 and age, systolic blood pressure BP9, diastolic blood pressure B
P10 is calculated. FIG. 13 shows Tu0 and R as features.
Determination line L1 when calculating blood pressure BP using d
1, L12. Here, L11 is for maximum blood pressure, and L12 is for minimum blood pressure. Tu0 and Rd are as described above. The blood pressure calculation unit 19 calculates the systolic blood pressure BP11 and the diastolic blood pressure BP from Tu0 and Rd based on FIG.
12 is calculated.

In ST6, when the reference value of the blood pressure is inputted to the reference value input section 20, the judgment line is corrected in ST7. The specific procedure of the correction will be described with reference to FIG. FIG.
Is for correcting the determination lines L1 and L2 for calculating the blood pressure BP based on EI and DI shown in FIG.
It is assumed that DI is fixed for the sake of simplicity. During the measurement of EI0 ', blood pressures BP1' and BP2 'are simultaneously measured by a cuff-type sphygmomanometer, and these values are input from reference value input unit 20 as reference values. In ST7, based on the input reference value, the blood pressure calculation unit 19 determines the determination line L1,
L2 is corrected. That is, the reference value EI is obtained from FIG.
When the points p8 and p9 are obtained from 0 ', BP1' and BP2 ', the judgment lines L1 and L2 are translated so as to pass through p8 and p9, and the newly formed judgment lines are defined as L1' and L2 '. Thereafter, the blood pressure calculation unit 20 determines the determination lines L1 ', L2'
Are used to determine BP1 and BP2 from EI0. Note that ST
When there is no input of the reference value in Step 6, the blood pressure calculation unit 20 does not correct the determination line.

In ST8, the blood pressure thus obtained is stored in the storage unit 21, and in ST9, the blood pressure is displayed on the display unit 22. The value stored in the storage unit 21 can be reproduced at any time and can be displayed on the display unit 22. When the calculated blood pressure deviates from the preset normal range, the alarm generation unit 23 generates an alarm in ST10 and ST11. The generation of the alarm may be notified to a third person located away from the user by wire or wirelessly. The calculated and stored blood pressure value can be communicated to an external medium such as an external monitor, a centralized management device, a personal computer, a mobile phone, or the like via the communication terminal unit 31. It is also possible to input a feature value and a reference value from an external medium via the communication terminal unit 31, update a determination line and a normal range for generating an alarm, and the like.

The above-mentioned judgment line can be obtained by, for example, processing a result selected by a subject experiment or the like by a statistical method. In addition, the feature amount when obtaining the determination line is not limited to the range of the above embodiment, and other feature amounts calculated by the feature amount calculating unit 11, for example, α to δ, H
R, Pi, δ / γ, Isp, a to e, Rc, Re, acceleration pulse wave interval, at least one of feature quantities, height, weight, gender, etc. selected from fourth or higher differential waveform of pulse wave May be used to determine the determination line. Further, in the above embodiment, the blood pressure is calculated from at least two characteristic amounts, but the blood pressure may be calculated from three or more characteristic amounts.

In this embodiment, the pulse wave at the fingertip is detected as shown in FIG. 2 and FIG. 3. However, the structure to detect the photoelectric pulse wave from the earlobe or the fingertip of the toe, the upper arm, the wrist, A configuration in which a pressure pulse wave of a main artery is detected from the neck and chest may be adopted. In this case, as a configuration for detecting the photoelectric pulse wave, the first light emitting unit 29 and the first light receiving unit 30 as described in the above embodiment are used in accordance with the detection site. As a configuration for detecting a pressure pulse wave, for example, a pressure sensor or an acceleration sensor is used, and preferably, a sensor such as a film-shaped flexible polymer piezoelectric sensor or a strain gauge is used according to a detection portion.

According to the first embodiment of the present invention, a characteristic value related to blood pressure is calculated from the detected pulse wave signal, and the blood pressure is calculated based on the calculated characteristic value. It is only necessary to perform the measurement for blood pressure, which eliminates the complexity of the operation, enables continuous measurement for a long time, improves the usability, and measures the blood pressure by calculating the characteristic amount related to the blood pressure. Blood pressure can be measured accurately even if the wave shape changes.

Further, since the pulse wave correction unit corrects the pulse wave signal at pulse wave intervals, the blood pressure can be accurately calculated regardless of the magnitude of the pulse.

Further, the wave feature quantity calculation unit calculates each pulse height of the pulse wave signal, the ratio of each pulse height, the time from the rising point of the pulse wave to each wave, the time interval between each wave, the integral value of the pulse wave, Since at least one of the pulse rates is calculated as a pulse wave feature, and the blood pressure calculation means calculates the blood pressure based on the pulse wave feature, the blood pressure can be accurately measured even if the blood pressure changes due to high blood pressure or arteriosclerosis. it can.

The speed pulse wave calculating section calculates a speed pulse wave, which is the first derivative of the pulse wave, and the speed pulse wave feature quantity calculating section calculates each wave height of the speed pulse wave signal, the ratio of each wave height, and the speed. Time from the pulse wave rising point to each wave, time interval between each wave,
At least one of the zero-cross intervals of the velocity pulse wave is calculated as a velocity pulse wave characteristic amount, and the blood pressure computation means computes the blood pressure based on the velocity pulse wave characteristic amount. Even with this, blood pressure can be accurately measured.

The acceleration pulse wave calculating section calculates an acceleration pulse wave which is a second derivative of the pulse wave based on the pulse wave signal output from the pulse wave detecting means. At least one of each wave height of the signal, the ratio of each wave height, and the time interval between each wave is calculated as an acceleration pulse wave feature value, and the blood pressure calculation means calculates blood pressure based on the acceleration pulse wave feature value. Blood pressure can be accurately measured even if the pulse wave shape changes due to arteriosclerosis.

Further, since the blood pressure calculating means calculates the blood pressure based on the body characteristic amount input to the body characteristic amount input section, the practicality can be improved and the blood pressure can be measured with high accuracy.

In addition, since the relationship between at least one of the pulse wave characteristic amount, the velocity pulse wave characteristic amount, the acceleration pulse wave characteristic amount, and the body characteristic amount and the blood pressure to be calculated can be corrected by the input reference value. It is possible to respond to changes in the user's blood circulation dynamics or changes in users due to changes in constitution, exercise, changes in body position, etc.
Blood pressure can be measured accurately.

Further, the blood pressure calculating means has a storage unit for storing the calculated blood pressure, and the stored value can be reproduced at any time by the blood pressure calculating means. .

Further, since the blood pressure value calculating means has a display for displaying the calculated blood pressure, real-time display and stored past data can be displayed at any time, which is convenient.

Further, when the calculated blood pressure deviates from the normal range, the alarm generation unit generates an alarm, so that it is possible to check, for example, abnormalities in the body while sleeping or working, which is useful for health management.

Further, since the blood pressure value calculating means has a communication terminal for communicating with an external medium and communicates with the external medium, it is possible to perform centralized health management and update necessary information on the external medium. Usability can be improved.

(Embodiment 2) FIG. 15 is a block diagram showing a blood pressure measurement apparatus according to Embodiment 2 of the present invention, and FIGS. 16 and 17 are external views of the apparatus.

The second embodiment differs from the first embodiment in that the pulse wave detector 8 has a plurality of pulse wave detectors 9a to 9n for detecting pulse waves at different parts of the human body. 11 has a pulse wave propagation feature amount calculation unit 32 that calculates at least one of a pulse wave propagation time and a pulse wave propagation speed as a pulse wave propagation feature amount based on the pulse wave signals from the pulse wave detection units 9a to 9n; The blood pressure calculating means 18 calculates the pulse wave feature amount, the speed pulse wave feature amount,
The blood pressure is calculated based on at least one of the acceleration pulse wave feature amount, the pulse wave propagation feature amount, and the body feature amount, and the reference value of the blood pressure is used as a teacher signal, and the pulse wave feature amount, the velocity pulse wave feature amount, the acceleration pulse wave are calculated. The point is to learn the relationship between at least one of the feature amount, the pulse wave propagation feature amount, and the body feature amount and the blood pressure to be calculated.
FIG. 16 and FIG. 17 are external views of the main body 24 when detecting pulse waves at two places, that is, a fingertip and another part. FIG. 16 is a view in which the insertion portion 27 of the first embodiment is viewed upward, and in the present embodiment, the second light emitting portion 33 and the second light emitting portion 33 are located on the side opposite to the side where the fingertip of the insertion portion 27 is inserted. Are mounted. The second light emitting unit 33 and the second light receiving unit 34 are configured to detect a pulse wave at a part other than the fingertip, and have, for example, the same structure as the first light emitting unit 29 and the first light receiving unit 30. I have. Here, the first light emitting section 29 and the first light receiving section 30 correspond to the first pulse wave detecting section 9a ', and the second light emitting section 33 and the second light receiving section 34 correspond to the second pulse wave detecting section 9b'. Become. Note that the first light emitting unit 29 and the second light emitting unit 33 may be configured to be the same as the same light emitting unit. FIG. 17 shows an embodiment in which the pressure sensor 35 as the second pulse wave detector 9b 'is mounted at the same place where the first light emitting unit 29 and the first light receiving unit 30 are mounted in FIG. is there. The pressure sensor 35 detects a pressure change (pressure pulse wave) on the skin surface due to a pulse at a part other than the fingertip and a vibration due to a heartbeat. For example, a film-like flexible polymer piezoelectric sensor or a strain gauge is used. Be composed. Further, the second pulse wave detector 9b 'may be constituted by a microphone for detecting heart sounds.

The components having the same reference numerals as in the first embodiment have the same structure, and the description is omitted. Next, the operation and operation will be described.
The fingertip is inserted into the pulse wave detection section 9a 'of the insertion section 27, and FIG.
As described above, the main body 24 is attached to the fingertip, and the pulse wave detector 9b 'is brought into contact with any one of the earlobe, neck, and chest to start measuring the blood pressure. The following description will be made on the assumption that the earlobe is brought into contact with the earlobe. Since the flowchart at the time of blood pressure measurement is the same as that in FIG.
The detailed procedure in T4 and ST5 will be described. ST1
When the pulse wave is detected in ST3 to ST3 and the pulse wave is corrected as necessary, the feature value calculating means 11
The feature amount is calculated based on the pulse wave signal from. The calculation of the pulse wave feature, the velocity pulse wave feature, the acceleration pulse wave feature, and the body feature are the same as described in the first embodiment. Here, the procedure of calculating the pulse wave propagation time and the pulse wave propagation velocity as the pulse wave propagation characteristic amount in the pulse wave propagation characteristic amount calculation unit 32 will be described with reference to FIGS. FIG. 19 (a),
(B) shows pulse wave signals detected at the fingertip and the earlobe, respectively. The pulse wave from the earlobe is detected by bringing the second pulse wave detector 9b 'in FIG. 16 into contact with the earlobe. From FIG. 19, the pulse wave propagation time is obtained as the time difference Tc between the rising points S1 and S2 of each pulse wave. If the user's height, weight, gender, age, and the like have been input in advance from the body feature input unit 17, the pulse wave propagation feature calculation unit 32 based on the input body feature inputs the heart of each of the earlobe and fingertip. Is calculated, and Tc is divided by the difference between the two lengths to obtain a feature amount corresponding to the pulse wave propagation velocity.

At ST5, the blood pressure calculating means 18 calculates the blood pressure from the preset judgment line. FIG. 20 shows the determination lines L13 and L14 when the blood pressure BP is calculated using Tu0 and Tc as the feature amounts. Where L1
3 is for maximum blood pressure, and L14 is for minimum blood pressure. Tu0 is as described above. Tc is related to the degree of resistance of the arterial duct, and when Tc is small, blood pressure tends to increase. The blood pressure calculation unit 19 calculates the systolic blood pressure BP13 and the diastolic blood pressure BP14 from Tu0 and Tc based on FIG.

In the above embodiment, the main body 24 shown in FIG.
17 was used to detect the photoelectric pulse wave from the fingertip and the earlobe.
As shown in FIG. 18, the second pulse wave detector 9b 'is brought into contact with the cervix and the chest using the main body 24 shown in FIG. 18 to detect the photoelectric pulse wave from the fingertip and to detect the pressure pulse wave from the neck and the chest. The pulse wave propagation time and the pulse wave propagation speed may be calculated from the detected pulse wave and the pulse wave at the fingertip of the hand. In addition, a heart sound may be detected by a microphone as a pulse wave, and a pulse wave propagation time or a pulse wave propagation velocity may be calculated from the heart sound and the pulse wave at the fingertip. Since the heart sound can be detected, the calculation accuracy of the pulse wave propagation time and the pulse wave propagation velocity is improved.

Next, in ST6, when the reference value of the blood pressure is inputted to the reference value input section 20, the judgment line is corrected in ST7. In this case, a reference value of blood pressure is input in the same procedure as in the first embodiment, and is calculated with at least one of a pulse wave feature, a velocity pulse wave feature, an acceleration pulse wave feature, a pulse wave propagation feature, and a body feature. Although the relationship with the blood pressure to be performed may be corrected,
Here, the blood pressure value calculation unit 19 further uses the input reference value of the blood pressure as a teacher signal, and sets at least one of the pulse wave feature amount, the speed pulse wave feature amount, the acceleration pulse wave feature amount, the pulse wave propagation feature amount, and the body feature amount. The determination line is corrected by learning the relationship between the blood pressure and the calculated blood pressure. A learning method that imitates a neural network is used as a component of the blood pressure value calculation unit 19 that performs learning. The input data is at least one of the pulse wave characteristic amount, the velocity pulse wave characteristic amount, the acceleration pulse wave characteristic amount, the pulse wave propagation characteristic amount, and the body characteristic amount from the characteristic amount calculating means 11, and the output data is the storage unit 21 and the display. It is assumed that the signal is a blood pressure signal to the unit 22, and a desired output (that is, a teacher signal) is a reference value input unit 20.
Output signal from The reference value is a value of the blood pressure measured by the cuff type sphygmomanometer. Examples of the neural network schematic means include Document 1 (PDP model, DE Ramelhart et al., 2 persons, translated by Shunichi Amari, 1989), Document 2 (Basic of neurocomputer, p102, Kaoru Nakano et al., 7 persons,
1990), and JP-B-63-55106.

Hereinafter, the configuration and operation of a specific neural network model will be described with reference to a multilayer perceptron using an error back propagation method as an example of the most well-known learning algorithm described in Document 1.

FIG. 21 is a conceptual diagram of a neural element which is a structural unit of the neural network model. In FIG. 21, 40
Numerals 1 to 40N are pseudo-synaptic coupling converters that schematically represent synaptic connections of nerves, and reference numeral 40a is an adder that adds outputs from the pseudo-synaptic coupling converters 401 to 40N.
0b is a set nonlinear function, for example, the threshold is h
Sigmoid function,

[0079]

(Equation 2)

Is a nonlinear converter for nonlinearly converting the output of the adder 40a. Although not shown for simplicity of the drawing, an input line for receiving a correction signal from the correction means is connected to the pseudo-synaptic coupling converters 401 to 40N and the non-linear converter 40b. Further, the pseudo synapse connection converters 401 to 40N serve as connection weight coefficients of the neural network model. This neural element has two types of operation modes, a signal processing mode and a learning mode.

Hereinafter, the operation of each mode of the neural element will be described with reference to FIG. First, the operation in the signal processing mode will be described. The neural element has N inputs X1 to X1.
Receives Xn and produces one output. i-th input signal Xi
Is the i-th pseudo-synaptic coupling converter 4 indicated by a square.
At 0i, it is converted to Wi · Xi. N signals W1 · 1 converted by the pseudo-synaptic connection converters 401 to 40N
X1 to Wn · Xn enter the adder 40a, and the addition result y is sent to the non-linear converter 40b to be the final output f (y, h). Next, the operation in the learning mode will be described. In the learning mode, the pseudo synapse connection converters 401 to 40N
And conversion parameters W1 to Wn and h of the nonlinear converter 40b.
Are corrected by the correction amounts ΔW1 to ΔW1 of the conversion parameters from the correction means.
Upon receiving the correction signals representing Wn and Δh,

[0082]

(Equation 3)

The above is corrected. FIG. 22 is a conceptual diagram of a signal conversion unit in which four of the above neural elements are connected in parallel.
Needless to say, the following description does not specify the number of neural elements constituting the signal conversion means as four.
In FIG. 22, reference numerals 511 to 544 denote pseudo-synaptic coupling converters, and reference numerals 501 to 504 denote add-nonlinear converters that combine the adder 40a and the non-linear converter 40b described in FIG. In FIG. 22, the illustration is omitted as in FIG. 21 because the drawing becomes complicated, but the input lines for receiving the correction signals from the correction means are connected to the pseudo-synaptic coupling converters 511 to 544 and the addition nonlinear converters 501 to 504. . The pseudo synapse connection converters 511 to 544 also become connection weight coefficients. Regarding the operation of this signal conversion means, the operation of the neural element described in FIG. 21 is performed in parallel.

FIG. 23 is a block diagram showing the structure of the signal processing means when the error backpropagation method is employed as a learning algorithm. Reference numeral 61 denotes the above-described signal conversion means. However, here, M neural elements receiving N inputs are arranged in parallel. Reference numeral 62 denotes a correction unit that calculates a correction amount of the signal conversion unit 61 in the learning mode. Hereinafter, the operation in the case of learning the signal processing means will be described with reference to FIG. The signal conversion means 61 receives N inputs Sin (X) and outputs M outputs Sout (X). The correction means 62 includes an input signal Sin (X) and an output signal S
out (X), and waits until M error signals δj (X) are input from the error calculation means or the signal conversion means at the subsequent stage. The error signal δj (X) is input and the correction amount is

[0085]

(Equation 4)

The correction signal is sent to the signal conversion means 61. The signal conversion means 61 corrects the conversion parameters of the internal nerve elements according to the learning mode described above.

FIG. 24 is a block diagram showing the configuration of a multilayer perceptron using a neural network model.
X, 71Y, and 71Z are signal conversion means composed of K, L, and M neural elements, respectively.
2Z is a correction means, and 73 is an error calculation means. The operation of the multilayer perceptron configured as described above will be described with reference to FIG. In the signal processing means 70X, the signal conversion means 71X has the input Siin
(X) (i = 1 to N), and outputs Sjout (X) (j =
1 to K). The correcting means 72X outputs the signal Siin
(X) and the signal Sjout (X), and an error signal δj (X)
It waits until (j = 1 to K) is input. Hereinafter, the same processing is performed in the signal processing means 70Y and 70Z,
The final output Shout (Z) (h = 1
To M) are output. The final output Shout (Z) is also sent to the error calculation means 73. In the error calculating means 73, an error from the ideal output T (T1,..., TM) is calculated based on a square error evaluation function COST (Equation 5) shown below, and an error signal δh (Z) is the correction means 72Z
Sent to

[0088]

(Equation 5)

Here, μ is a parameter that determines the learning speed of the multilayer perceptron. Next, if the evaluation function is a square error, the error signal is

[0090]

(Equation 6)

Is obtained. The correction unit 72Z calculates the correction amount ΔW (Z) of the conversion parameter of the signal conversion unit 71Z according to the procedure described above, calculates an error signal to be sent to the correction unit 72Y based on (Equation 7), and calculates the correction signal. ΔW
(Z) is sent to the signal conversion means 71Z, and the error signal δ (Y)
To the correction means 72Y. The signal conversion means 71Z corrects internal parameters based on the correction signal ΔW (Z). Note that the error signal δ (Y) is given by (Equation 7).

[0092]

(Equation 7)

Here, wij (Z) is the signal converting means 71Z
Is a conversion parameter of the pseudo-synaptic coupling converter. Hereinafter, similar processing is performed in the signal processing units 70X and 70Y. By repeatedly performing the above procedure called learning, the multilayer perceptron, when given an input, outputs an output that approximates the ideal output T well. In the above description, a three-stage multilayer perceptron is used, but the number of stages may be any. Reference 1
The method for correcting the conversion parameter h of the non-linear conversion means in the signal conversion means and the method for speeding up learning, which is known as an inertia term, are omitted for simplicity of description, but this omission restricts the present invention. It does not do.

As described above, the blood pressure calculating section 19 having the neural network model means receives the pulse wave feature quantity, velocity pulse wave feature quantity, acceleration pulse wave feature quantity, pulse wave propagation feature quantity, Even if it is not easy to describe what operation is preferable by using simple rules using information obtained from a feature amount signal such as a body feature amount and an output signal of the reference value input unit 20, the past It can be expressed in a natural way by learning based on experience.

In other words, the blood pressure calculating section 19 gradually learns the relationship between the characteristic amount information obtained from the characteristic amount signal from the characteristic amount calculating section 11 and the blood pressure reference value signal from the reference value input section 20 on site. As a result, the blood pressure corresponding to the feature amount information from the feature amount calculating unit 11 is finally output without correction by inputting the reference value. Furthermore, when the same user changes his or her body position at the time of measurement, uses another user with a different body type, or measures during exercise, the user is newly calculated using the reference value input unit 20. If the blood pressure is corrected, the blood pressure calculation unit 19 follows this by learning.

Incidentally, as a component of the blood pressure calculating section 19 for performing learning, a vector quantization learning method of a competitive pattern classification type suitable for additional learning may be used instead of the error back propagation method. Instead of using a learning method imitating a neural network, a method such as a table lookup method based on an appropriate rule, artificial intelligence, or a genetic algorithm may be used.

According to the second embodiment of the present invention, the pulse wave detecting section detects pulse waves at different parts of the human body, and the pulse wave propagation characteristic amount calculating section calculates the pulse wave propagation time and the pulse wave based on the pulse wave signal. At least one of the propagation speeds is calculated as a pulse wave propagation feature, and the blood pressure calculation means calculates the blood pressure based on the pulse wave propagation feature,
The pulse wave propagation characteristic amount can be calculated without the complicated arrangement of the cardiac potential electrodes and the usability can be improved, and the blood pressure can be accurately measured even if the pulse wave shape changes due to hypertension or arteriosclerosis.

Further, the blood pressure calculating means calculates the blood pressure based on at least one of the pulse wave characteristic amount, the velocity pulse wave characteristic amount, the acceleration pulse wave characteristic amount, the pulse wave propagation characteristic amount, and the body characteristic amount. Blood pressure can be accurately measured even if the pulse wave shape changes due to curing.

Further, the relation between the characteristic amount information obtained from the characteristic amount signal from the characteristic amount calculating means and the blood pressure reference value signal from the reference value input unit is gradually learned on site, and finally the reference value Since the blood pressure corresponding to the characteristic amount information from the characteristic amount calculating means is output even without correction by input, there is an effect that the accuracy of blood pressure measurement is significantly improved as compared with the first embodiment.

Further, the pulse wave detecting means detects a pulse wave from a fingertip of the hand, and a pulse wave is installed from the portion other than the fingertip and installed adjacent to the first pulse wave detecting portion. Since it has the second pulse wave detecting unit for detection, it is possible to reduce the size and to carry it easily.

The first pulse wave detecting section and the second pulse wave detecting section each have a light emitting section and a light receiving section for detecting a pulse wave by the photoelectric pulse wave method, and both light emitting sections are shared. As a result, the number of parts can be reduced and the utility is high.

The second pulse wave detector comprises a pressure sensor for detecting a pulse pressure. The second pulse wave detector detects a pressure pulse wave from the neck and chest and can detect a pulse wave at a position close to the heart. The calculation accuracy of the wave propagation speed can be improved.

Further, the second pulse wave detecting section may be a microphone for detecting a heart sound. Since the second pulse wave detecting section detects a vibration or a heart sound due to the heartbeat, it is possible to improve the calculation accuracy of the pulse wave propagation time and the pulse wave propagation speed. it can.

Each of the characteristic quantities calculated as described in the first and second embodiments is related to the blood pressure. For example, EI is related to the elasticity of the arterial tract wall, and DI is the caliber of the arterial tract. That is, it is also possible to determine whether the blood circulation dynamics of the human body other than the blood pressure is good or bad, based on the respective characteristic amounts, as in relation to the degree of arterial tract tension. In this case, the blood circulation dynamics of the human body may be determined simply from the respective characteristic amounts at a certain time, or the blood circulation dynamics of the human body may be determined based on the temporal variation of each characteristic amount, for example, The blood circulation dynamics of the human body may be determined based on the trend of the time-series data of each feature amount, the frequency analysis result of the time-series data, the degree of fluctuation, the chaos, and the like. In this way, while calculating the blood pressure based on each feature amount, for example, determine the blood circulation dynamics of the human body, such as the degree of arteriosclerosis,
The judgment result can be displayed simultaneously with the blood pressure, and the circulatory system of the human body can be comprehensively evaluated, which is useful for health management and the like.

[0105]

As described above, the blood pressure measurement device according to the first aspect of the present invention calculates a characteristic amount related to blood pressure from a detected pulse wave signal, and calculates a blood pressure based on the calculated characteristic amount. The sensor to be worn on the human body only needs to be a pulse wave sensor, which eliminates the complexity of operation when measuring blood pressure, enables continuous measurement for a long time, improves usability, and reduces the characteristic amount related to blood pressure. Since the blood pressure is measured by calculation, there is an effect that the blood pressure can be accurately measured even if the pulse wave shape changes.

Further, in the blood pressure measurement device according to the second aspect, since the pulse wave correction unit corrects the pulse wave signal at the pulse wave interval, there is an effect that the blood pressure can be accurately measured regardless of the magnitude of the pulse.

According to a third aspect of the present invention, in the blood pressure measurement device, the pulse wave characteristic quantity calculating section includes a pulse wave signal, a pulse wave signal ratio, and a pulse wave ratio.
At least one of the time from the pulse wave rising point to each of the waves, the time interval between each of the waves, the integral value of the pulse wave, and the pulse rate is calculated as a pulse wave feature value, and the blood pressure calculation means calculates the pulse wave feature value. Since the blood pressure is calculated based on the blood pressure, the blood pressure can be accurately measured even if the pulse wave shape changes due to high blood pressure or arteriosclerosis.

Further, in the blood pressure measuring device according to the fourth aspect, the velocity pulse wave calculating section calculates a velocity pulse wave which is a first derivative of the pulse wave, and the velocity pulse wave feature quantity computing section calculates each pulse height of the velocity pulse wave signal. The ratio of each wave height, the time from the rising point of the speed pulse wave to each wave, the time interval between the waves, at least one of the zero cross interval of the speed pulse wave is calculated as a speed pulse wave feature amount, Since the blood pressure calculating means calculates the blood pressure based on the velocity pulse wave feature quantity, there is an effect that the blood pressure can be measured accurately even if the pulse wave shape changes due to hypertension or arteriosclerosis.

According to a fifth aspect of the present invention, in the blood pressure measurement device, the acceleration pulse wave calculating section calculates an acceleration pulse wave, which is a second derivative of the pulse wave, based on the pulse wave signal output from the pulse wave detecting means. The feature amount calculation unit calculates at least one of each wave height of the acceleration pulse wave signal, the ratio of each wave height, and the time interval between the waves as an acceleration pulse wave feature amount, and the blood pressure calculation unit calculates the acceleration pulse wave feature amount. Since the blood pressure is calculated based on the blood pressure, the blood pressure can be accurately measured even if the pulse wave shape changes due to high blood pressure or arteriosclerosis.

Further, in the blood pressure measuring device according to the present invention, the pulse wave detecting section detects a pulse wave in a different part of the human body, and the pulse wave propagation characteristic quantity calculating section calculates the pulse wave propagation time and the pulse wave based on the pulse wave signal. Since at least one of the propagation velocities is calculated as a pulse wave propagation characteristic amount, and the blood pressure calculation means calculates the blood pressure based on the pulse wave propagation characteristic amount, the pulse wave propagation characteristic amount does not have to be worn like a cardiac potential electrode. Can be calculated, the usability is improved, and the blood pressure can be accurately measured even if the pulse wave shape changes due to hypertension or arteriosclerosis.

Further, in the blood pressure measuring device according to claim 7, since the blood pressure calculating means calculates the blood pressure based on the body characteristic amount inputted to the body characteristic amount input section, the practicality can be improved and the blood pressure can be accurately measured. It has the effect of being measurable.

In the blood pressure measuring apparatus according to the present invention, the blood pressure calculating means may be configured to determine the blood pressure based on at least one of a pulse wave feature, a velocity pulse wave feature, an acceleration pulse wave feature, a pulse wave propagation feature, and a body feature. Is calculated, the blood pressure can be accurately measured even if the pulse wave shape changes due to high blood pressure or arteriosclerosis.

Further, the blood pressure measurement device according to the ninth aspect calculates at least one of a pulse wave characteristic amount, a velocity pulse wave characteristic amount, an acceleration pulse wave characteristic amount, a pulse wave propagation characteristic amount, and a body characteristic amount based on the input reference value. Since the relationship with blood pressure can be corrected, it is possible to cope with a change in the user's blood circulation dynamics or a change in the user due to, for example, aging, change in constitution, exercise, change in body position, etc. In addition, the blood pressure can be accurately measured.

The blood pressure measurement device according to the tenth aspect gradually learns on-site the relationship between the characteristic amount information obtained from the characteristic amount signal from the characteristic amount calculation means and the blood pressure reference value signal from the reference value input unit. Finally, since the blood pressure corresponding to the feature amount information from the feature amount calculating means is output even without correction by inputting the reference value, there is an effect that blood pressure measurement accuracy is improved.

In the blood pressure measuring apparatus according to the eleventh aspect, the pulse wave detecting means may include a fingertip of a hand, an earlobe, a fingertip of a foot, an upper arm, a wrist,
Neck, can be attached to at least one part of the chest,
Since the pulse wave can be easily detected at any part, there is an effect that usability can be improved.

Further, the blood pressure measurement device according to the twelfth aspect has an effect that the first pulse wave detection unit and the second pulse wave detection unit are adjacent to each other, so that the size can be reduced and the device is portable.

Further, the blood pressure measurement device according to the thirteenth aspect has an effect that the number of parts can be reduced and the practicability is high because both light emitting parts are shared.

The blood pressure measuring device according to claim 14 can detect a pressure pulse wave from the neck and chest from the pressure sensor and detect a pulse wave at a position close to the heart, so that the calculation accuracy of the pulse wave propagation time and the pulse wave propagation speed can be improved. There is an effect that it can be improved.

Further, the blood pressure measuring device according to the fifteenth aspect has the effect of improving the calculation accuracy of the pulse wave propagation time and the pulse wave propagation speed because the microphone detects the vibration and heart sound caused by the beating of the heart with the microphone.

Further, in the blood pressure measuring device according to the sixteenth aspect, the stored value can be reproduced at any time by the blood pressure calculating means, so that there is an effect that the trend of the judgment value from the past can be recognized and the usability is good.

Further, the blood pressure measurement device according to the seventeenth aspect has an effect that the real-time display and the stored past data can be displayed at any time, and the usability is good.

In the blood pressure measuring device according to the eighteenth aspect, when the calculated blood pressure deviates from the normal range, the alarm generating unit generates an alarm, so that it is possible to check for abnormalities in the body while sleeping or working, for example, and to manage health. Has the effect of helping.

Further, since the blood pressure measurement device according to the nineteenth aspect communicates with an external medium via the communication terminal unit, it is possible to perform intensive health management and update necessary information with the external medium, thereby improving usability. This has the effect.

[Brief description of the drawings]

FIG. 1 is a block diagram of a blood pressure measurement device according to a first embodiment of the present invention.

FIG. 2 is an external view of the blood pressure measurement device.

FIG. 3 is a diagram showing a site where the blood pressure measurement device is attached to a human body.

FIG. 4 is a flowchart showing a blood pressure measurement procedure of the blood pressure measurement device.

FIG. 5A is a waveform characteristic diagram showing a post-normal ridge wave in the blood pressure measurement device. FIG. 5B is a waveform characteristic diagram showing a same-speed pulse wave. FIG. 5C is a characteristic diagram showing the same acceleration pulse wave.

FIG. 6A is a waveform characteristic diagram showing a pulse wave of a front ridge wave. FIG. 6B is a waveform characteristic diagram showing a pulse wave of the same velocity.

7A is a characteristic diagram showing a procedure for obtaining a feature amount of a frontal ridge in the same blood pressure measurement device. FIG. 7B is a characteristic diagram showing a procedure for obtaining a feature amount of the frontal ridge. Characteristic diagram showing the procedure for obtaining feature values

FIG. 8 is a characteristic diagram showing a relationship between blood pressure and EI and DI in the blood pressure measurement device.

FIG. 9 is a characteristic diagram showing a relationship between blood pressure and Tu and Te in the blood pressure measurement device.

FIG. 10 is a characteristic diagram showing a relationship between blood pressure and Tu, v in the blood pressure measurement device.

FIG. 11 is a characteristic diagram showing a relationship between blood pressure and Rb and Rd in the blood pressure measurement device.

FIG. 12 is a characteristic diagram showing a relationship between blood pressure, EI, and age in the blood pressure measurement device.

FIG. 13 is a characteristic diagram showing a relationship between blood pressure and Tu and Rd in the blood pressure measurement device.

FIG. 14 is a characteristic diagram showing a procedure for correcting a blood pressure determination line with a reference value in the blood pressure measurement device.

FIG. 15 is a block diagram of a blood pressure measurement device according to a second embodiment of the present invention.

FIG. 16 is an external view of the blood pressure measurement device.

FIG. 17 is an external view of the blood pressure measurement device.

FIG. 18 is a diagram showing a site where the blood pressure measurement device is attached to a human body.

FIG. 19A is a characteristic diagram showing a procedure for obtaining Tc in the blood pressure measurement device. FIG. 19B is a characteristic diagram showing a procedure for obtaining the TC.

FIG. 20 is a characteristic diagram showing a relationship between blood pressure and Tu and Tc in the blood pressure measurement device.

FIG. 21 is a conceptual diagram of a neural element which is a structural unit of a neural network schematic unit of the blood pressure measurement device.

FIG. 22 is a conceptual diagram of a signal conversion unit in which four neural elements of the blood pressure measurement device are connected in parallel.

FIG. 23 is a block diagram illustrating a configuration of a signal processing unit when an error back propagation method is employed as a learning algorithm of the blood pressure measurement device.

FIG. 24 is a block diagram showing a configuration of a multilayer perceptron using a neural network model of the blood pressure measurement device.

FIG. 25 is a block diagram of a conventional blood pressure measurement device.

FIG. 26 shows PTT and P in the conventional blood pressure measurement device.
A characteristic diagram showing a procedure for obtaining I, Tb, x, and y.

[Explanation of symbols]

 Reference Signs List 8 pulse wave detecting means 9 pulse wave detecting section 9a to 9n pulse wave detecting section 9a 'first pulse wave detecting section 9b' second pulse wave detecting section 10 pulse wave correcting section 11 feature amount calculating means 12 pulse wave feature amount Calculation part 13 Velocity pulse wave calculation part 14 Velocity pulse wave feature quantity calculation part 15 Acceleration pulse wave calculation part 16 Acceleration pulse wave feature quantity calculation part 17 Body feature quantity input part 18 Blood pressure calculation means 20 Reference value input part 21 Storage part 22 Display Unit 23 alarm generating unit 29 first light emitting unit 30 first light receiving unit 31 communication terminal unit 32 pulse wave propagation feature quantity calculating unit 33 second light emitting unit 34 second light receiving unit 35 pressure sensor

Claims (19)

[Claims] 1. A pulse wave detecting means for detecting a pulse wave generated by blood circulation of a human body, and a characteristic amount calculating means for calculating a characteristic amount related to blood pressure based on a pulse wave signal output from the pulse wave detecting means. A blood pressure calculating means for calculating a blood pressure based on the characteristic amount signal output from the characteristic amount calculating means. 2. The blood pressure measurement device according to claim 1, wherein the pulse wave detecting means has a pulse wave correction unit for calculating a pulse wave interval and correcting a pulse wave signal at the pulse wave interval. 3. The characteristic value calculating means includes means for calculating each pulse height of the pulse wave signal output from the pulse wave detecting means, a ratio of each of the pulse heights, a time from a pulse wave rising point to each of the waves, and a time interval between the waves. 3. A pulse wave feature value calculation unit for calculating at least one of an integrated value of a pulse wave and a pulse rate as a pulse wave feature value.
The blood pressure measurement device according to any one of the preceding claims. 4. A speed pulse wave calculating section for calculating a speed pulse wave which is a first derivative of the pulse wave based on a pulse wave signal output from the pulse wave detecting means, and a speed pulse wave calculating section. At least one of the wave height of the speed pulse wave signal output from the vehicle, the ratio of the wave heights, the time from the rising point of the speed pulse wave to the waves, the time interval between the waves, and the zero-cross interval of the speed pulse wave. The blood pressure measurement device according to any one of claims 1 to 3, further comprising a speed pulse wave feature value calculation unit that calculates one as a speed pulse wave feature value. 5. An acceleration pulse wave calculating section for calculating an acceleration pulse wave, which is a second derivative of the pulse wave, based on a pulse wave signal output from the pulse wave detecting means; An acceleration pulse wave feature value calculation unit that calculates at least one of each wave height of the acceleration pulse wave signal output from the unit, a ratio of the wave heights, and a time interval between the waves as an acceleration pulse wave feature amount. The blood pressure measurement device according to any one of claims 1 to 4. 6. The pulse wave detecting means has a plurality of pulse wave detecting sections for detecting pulse waves at different parts of a human body, and the characteristic amount calculating means is based on a pulse wave signal from the pulse wave detecting section. Propagation time,
The blood pressure measurement device according to any one of claims 1 to 5, further comprising a pulse wave propagation feature value calculation unit that calculates at least one of the pulse wave propagation speeds as a pulse wave propagation feature value. 7. The feature calculating means according to claim 1, wherein said feature calculating means has a body feature input unit capable of inputting at least one of a height, a weight, a sex, and an age of a human body as a body feature. Blood pressure measuring device. 8. The blood pressure calculation means calculates a blood pressure based on at least one of a pulse wave feature, a velocity pulse wave feature, an acceleration pulse wave feature, a pulse wave propagation feature, and a body feature. The blood pressure measurement device according to any one of claims 1 to 7. 9. The blood pressure calculation means has a reference value input unit capable of inputting a reference value of blood pressure, and includes a pulse wave characteristic amount, a velocity pulse wave characteristic amount, an acceleration pulse wave characteristic amount, and a pulse wave propagation characteristic amount. The blood pressure measurement device according to any one of claims 3 to 8, wherein a relationship between at least one of the body characteristic amounts and the calculated blood pressure can be corrected. 10. A blood pressure value calculating means calculates a reference value of blood pressure as a teacher signal and calculates at least one of a pulse wave characteristic amount, a velocity pulse wave characteristic amount, an acceleration pulse wave characteristic amount, a pulse wave propagation characteristic amount, and a body characteristic amount. The blood pressure measurement device according to any one of claims 3 to 9, wherein the blood pressure measurement device learns a relationship with the blood pressure to be performed. 11. The pulse wave detecting means can be attached to at least one of a fingertip, an earlobe, a toe fingertip, an upper arm, a wrist, a neck, and a chest, and detects a pulse wave at said portion. The blood pressure measurement device according to any one of claims 10 to 13. 12. A pulse wave detecting means for detecting a pulse wave from a fingertip of a hand, and a pulse wave detecting means installed adjacent to the first pulse wave detecting unit to detect a pulse wave from a part other than the fingertip. The blood pressure measurement device according to claim 11, further comprising a second pulse wave detection unit that detects the pulse wave. 13. A first pulse wave detecting section and a second pulse wave detecting section each have a light emitting section and a light receiving section for detecting a pulse wave by a photoelectric pulse wave method, and both light emitting sections are shared. Claim 12
The blood pressure measurement device according to any one of the preceding claims. 14. The blood pressure measurement device according to claim 12, wherein the second pulse wave detector comprises a pressure sensor for detecting a pulse pressure. 15. The blood pressure measurement device according to claim 12, wherein the second pulse wave detector comprises a microphone for detecting a heart sound. 16. The blood pressure measurement device according to claim 1, wherein the blood pressure value calculation means has a storage unit for storing the calculated blood pressure. 17. The blood pressure measurement device according to claim 1, wherein the blood pressure value calculation means has a display for displaying the calculated blood pressure. 18. The blood pressure measurement device according to claim 1, wherein the blood pressure value calculation means has an alarm generation unit that generates an alarm when the calculated blood pressure deviates from a predetermined normal range. apparatus. 19. The blood pressure measurement device according to claim 1, wherein the blood pressure value calculation means has a communication terminal for communicating with an external medium.