JP2000300525A - Manometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manometer which can obtain correct results of measurement by reducing possible errors attributed to personal difference, time difference or the like. SOLUTION: A main component computing means 20 obtains a main component showing the tendency of a change from an arterial pulse wave ingredient data Mnm stored in a memory means 4. Then, a stratification means 21 performs a comparison with a pattern of load line previously stored in a memory means 14 base on the shape of a load line of a first main component PC1 obtained by the main component computing means 20 to accomplish the stratification of the arterial pulse wave ingredient data Mnm. A selection means 22 selects the optimum threshold according the results of the stratification, and the selected threshold is applied to a judging means 16. Then, the blood pressure determination means 16 determines the maximum blood pressure value and the minimum blood pressure value from the data Mnm based on the threshold applied to the means 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a sphygmomanometer.

[0002]

2. Description of the Related Art Conventionally, an oscillometric extraction of an arterial pulse wave component for each heartbeat superimposed on a cuff pressure and judging a time point indicating a systolic blood pressure value and a diastolic blood pressure value based on a change in the arterial pulse wave component. Sphygmomanometers employing the method are known. FIG. 37 is a block diagram showing a conventional sphygmomanometer, in which a pressure pump 3, a rapid exhaust unit 4, and a gradual exhaust unit 5 are respectively connected to a cuff 1 attached to a main part of a human body to control a cuff pressure. 7 is controlled. The cuff pressure is converted to a voltage by the pressure sensor 2, converted to a digital signal by the A / D converter 6, and input to the control calculator 7. Then, the systolic blood pressure value and the diastolic blood pressure value of the subject are determined from the pressure value (pressure data) converted into a digital signal by the control arithmetic unit 7 and displayed on the display 8 or a notification means such as a buzzer Ring 9
Reference numeral 10 denotes an operation input unit for inputting a trigger signal for starting blood pressure measurement and the like to the control calculation unit 7, and reference numeral 11 denotes a power supply unit for supplying power to each unit.

FIG. 38 is a block diagram showing a specific configuration of the control operation unit 7. As shown in FIG. The digital signal input from the A / D converter 6 is converted into arterial pulse wave extracting means 12 and cuff pressure extracting means 13
The arterial pulse wave component (arterial counter pressure) superimposed on the cuff pressure is separated from the cuff pressure, and the arterial pulse wave extraction means 12
And the cuff pressure output from the cuff pressure extracting means 13 are sequentially stored in the storage means 14 as data. Using the arterial reaction pressure and the cuff pressure stored in the storage means 14, the calculation means 15 performs a comparison calculation described later.
The blood pressure determining means 16 obtains a systolic blood pressure value and a diastolic blood pressure value based on the calculation result by the calculating means 15 and displays the determined systolic and diastolic blood pressure values on the display 8.
Further, based on the calculation result of the calculation means 15, the exhaust speed and pulse rate are obtained by the exhaust speed / pulse rate monitor 17 and displayed on the display 8, and the cuff pressure is obtained by the cuff pressure monitor 18 and the display 8 is displayed. Will be displayed. Further, based on the cuff pressure detected by the cuff pressure monitor 18, the cuff pressure control means 19 controls the pressurizing pump 3, the quick exhaust unit 4, and the gradual exhaust unit 5. The arterial pulse wave extraction means 12,
The cuff pressure extracting means 13, the storing means 14, the calculating means 15, the blood pressure judging means 16, the exhaust speed / pulse rate monitor 18, the cuff pressure monitor 18, and the cuff pressure controlling means 19 are a CPU, a RO
A microcomputer having M, RAM, etc.
7 is operated according to a required program.

Next, the operation of the above conventional example will be described. First,
When the blood pressure measurement is started, the cuff pressure control unit 19 controls the pressurizing pump 3 to control the cuff 1 wound around the upper arm of the subject.
The air is sent to the inside to pressurize the blood. Thereafter, the cuff pressure control means 19 stops the pressurizing pump 3 and controls the gradual exhaust unit 5 to gradually exhaust the air inside the cuff 1 to gradually reduce the cuff pressure. During this exhaust period, the pressure sensor 2 detects a pressure at which the arterial reaction pressure and the cuff pressure are superimposed (see FIG. 39A). The analog output of the pressure sensor 2 is converted into a digital signal by the A / D converter 6 and input to the microcomputer 7. Here, the output of the A / D converter 6 is changed to the cuff pressure that decreases substantially linearly as shown in FIG.
(C) corresponds to the superimposed pressure, and by separating these, the arterial pulse wave extracting means 12 and the cuff pressure extracting means 13 separate the arterial reactive pressure as shown in FIG. And the pressure value of the cuff pressure as shown in FIG. And the maximum value Ma of the pulse wave value
x, and a predetermined ratio S [%], D is added to the maximum value Max.
The cuff pressure value corresponding to the arterial reaction pressure corresponding to the value multiplied by [%] is set as the maximum blood pressure value and the minimum blood pressure value, respectively.

[0005]

The peak value of each arterial pulse wave changes according to the blood flow in the blood-absorbing part as described above, but the degree of the change varies among individuals. Some people have little change in peak value near systolic or diastolic blood pressure (ie, the waveform shape of arterial pulse wave is different)
In some cases, even in the same person, the waveform of the arterial pulse wave may differ depending on the time. When the waveform shapes of the arterial pulse waves are different as described above, the systolic blood pressure timing and the diastolic blood pressure timing can be accurately determined even if the pulse wave value of the arterial reaction pressure is multiplied by a predetermined ratio as described above. However, there is a problem that it causes an error.

SUMMARY OF THE INVENTION An object of the present invention is to provide a sphygmomanometer capable of reducing the occurrence of errors due to individual differences and time differences and obtaining accurate measurement results.

[0007]

According to a first aspect of the present invention, there is provided a detecting means for detecting a physical value including biological information, and converting a detected value of the detecting means from an analog value to a digital value. A / D conversion means for performing processing, biological information extraction means for extracting a component corresponding to biological information from an output of the A / D conversion means, storage means for storing biological information data extracted by the biological information extraction means, and storage Principal component calculating means for calculating one or a plurality of principal components using the biological information data stored in the means as a variable, stratifying means for stratifying the biological information data by the principal components, Selecting means for selecting a determination criterion for determining a blood pressure value from biological information data from a plurality of candidates; and a blood pressure for determining a blood pressure value based on the biological information data according to the determination criterion selected by the selection means. Characterized in that a constant means,
Biological information data is stratified based on the principal components extracted from the biometric information data, and blood pressure values are determined according to criteria determined according to the stratified result. Measurement results are obtained.

A second aspect of the present invention is the same as the first aspect of the invention, wherein the detecting means detects the arterial pulse wave of the subject as the biological information. To play.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the stratification means has a calculation formula for associating the main component with the characteristics of the living body, and the stratification based on the biological characteristics obtained by the calculation formula. And has the same effect as the first or second aspect of the invention.

According to a fourth aspect of the present invention, in the first or second aspect of the present invention, the stratification means compares a main component with a plurality of patterns registered in advance and determines whether or not each component is substantially equivalent to each pattern. The present invention is characterized in that stratification is performed, and has the same effect as the first or second aspect of the invention.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects of the present invention, the stratifying means performs stratification by using only the first principal component among a plurality of principal components. Accordingly, the same operation as that of any one of the first to fourth aspects of the invention is achieved.

According to a sixth aspect of the present invention, in any one of the first to fourth aspects of the invention, the stratifying means performs stratification by using a principal component other than the first principal component among the plurality of principal components. It has the same effect as the invention of any one of claims 1 to 4.

According to a seventh aspect of the present invention, in any one of the first to fourth aspects, the stratifying means performs stratification by using a plurality of main components. It has the same effect as any of the inventions.

According to an eighth aspect of the present invention, in the second aspect of the present invention, there is provided means for averaging arterial pulse wave data corresponding to each heartbeat extracted in a time series. In addition to the effect similar to that of the invention, the S / N ratio of the arterial pulse wave data can be improved.

A ninth aspect of the present invention is characterized in that, in the second aspect of the present invention, there is provided means for obtaining data of arterial pulse waves corresponding to each heartbeat extracted in a time series as a change rate in a plurality of minute sections. Accordingly, the same effect as that of the invention of claim 2 can be obtained, and the S / N ratio of the arterial pulse wave data can be improved.

According to a tenth aspect of the present invention, in the first aspect of the present invention, the principal component calculating means obtains a principal component from a plurality of data sampled from the biological information data. In addition to the effect of the invention, the load of the calculation processing in the principal component calculation means can be reduced.

An eleventh aspect of the present invention is characterized in that, in the first aspect of the present invention, the sampling period in the A / D conversion means is variable, and in addition to the operation of the first aspect of the invention, the principal component arithmetic means Can reduce the load of the arithmetic processing.

According to a twelfth aspect of the present invention, in accordance with the eleventh aspect of the present invention, the sampling period in the A / D conversion means is varied according to the importance of the biological information.
In addition to the function of the eleventh aspect, necessary biological information can be reliably obtained.

According to a thirteenth aspect of the present invention, in the first aspect of the present invention, there is provided a temporary blood pressure determining means for determining a temporary blood pressure value of the subject based on the biological information data stored in the storage means. The means obtains a principal component from the biological information data in the vicinity of the provisional blood pressure value determined by the provisional blood pressure determination means. In addition to the operation of the invention according to claim 1, the processing load of the principal component calculation means is reduced. Can be reduced.

According to a fourteenth aspect of the present invention, in the second aspect of the present invention, the principal component calculating means obtains a principal component from the biological information data in the vicinity where the arterial pulse wave shows the maximum value.
In addition to the effect of the invention of claim 2, it is possible to reduce the load of the calculation processing in the principal component calculation means.

According to a fifteenth aspect of the present invention, in the second aspect of the present invention, the principal component calculating means is configured to unify the intervals of the arterial pulse wave of each one pulse to a substantially constant value. In addition to the effects of the invention, necessary arterial pulse wave components can be extracted without excess or deficiency.

A sixteenth aspect of the present invention is characterized in that the substantially constant value is set to 0.375 to 2.0 seconds in the invention of the fifteenth aspect, and has the same effect as the invention of the fifteenth aspect.

According to a seventeenth aspect of the present invention, in the second aspect of the present invention, a cuff to be attached to a main part of a subject to block blood, a pressure means for increasing a pressure in the cuff, and a pressure in the cuff gradually. The pressure in the cuff is superimposed on the cuff pressure from the output of the pressure sensor during the evacuation period in which the pressure in the cuff is converted into an electric signal by the detection means comprising a pressure sensor and the pressure in the cuff is gradually lowered. Biological information extracting means is constituted by a cuff pressure extracting means and an arterial pulse wave extracting means for separating an arterial pulse wave component and extracting a cuff pressure and an arterial pulse wave component, respectively. The intersection of a straight line connecting the inflection points of the arterial pulse wave of the heartbeat and the curve indicating the change of the cuff pressure is set as the starting point of the arterial pulse wave. Pulse wave components can be extracted without excess or deficiency. That.

According to an eighteenth aspect of the present invention, in the second aspect of the present invention, a cuff to be attached to a main part of the subject to block blood, a pressure means for increasing the pressure in the cuff, and a pressure in the cuff gradually. The pressure in the cuff is superimposed on the cuff pressure from the output of the pressure sensor during the evacuation period in which the pressure in the cuff is converted into an electric signal by the detection means comprising a pressure sensor and the pressure in the cuff is gradually lowered. Biological information extracting means is constituted by a cuff pressure extracting means and an arterial pulse wave extracting means for separating an arterial pulse wave component and extracting a cuff pressure and an arterial pulse wave component, respectively. The area of a portion surrounded by a straight line connecting the starting points and a curve indicating a change in the cuff pressure is extracted as an arterial pulse wave component. Extract arterial pulse wave components without excess or deficiency Can.

According to a nineteenth aspect of the present invention, in the second aspect of the present invention, a cuff to be attached to a main part of the subject to block blood, a pressure means for increasing the pressure in the cuff, and a pressure in the cuff gradually. The pressure in the cuff is superimposed on the cuff pressure from the output of the pressure sensor during the evacuation period in which the pressure in the cuff is converted into an electric signal by the detection means comprising a pressure sensor and the pressure in the cuff is gradually lowered. Biological information extracting means is constituted by a cuff pressure extracting means and an arterial pulse wave extracting means for separating an arterial pulse wave component and extracting a cuff pressure and an arterial pulse wave component, respectively. The area of a portion surrounded by a straight line connecting the maximum points and a curve indicating a change in cuff pressure is extracted as an arterial pulse wave component. Extraction of various arterial pulse wave components Door can be.

The invention of claim 20 is the invention of claim 18 or 19
In the invention of the above, the arterial pulse wave extracting means corrects the curve indicating the change of the cuff pressure and converts the straight line connecting the starting points of the arterial pulse wave components or the straight line connecting the maximum points to be orthogonal to the pressure axis. It has the same function as the invention of claim 18 or 19.

According to a twenty-first aspect of the present invention, in the second aspect of the present invention, a cuff to be attached to a main part of a subject to block blood, a pressure means for increasing the pressure in the cuff, and a pressure in the cuff gradually. The pressure in the cuff is superimposed on the cuff pressure from the output of the pressure sensor during the evacuation period in which the pressure in the cuff is converted into an electric signal by the detection means comprising a pressure sensor and the pressure in the cuff is gradually lowered. Biological information extracting means is constituted by a cuff pressure extracting means and an arterial pulse wave extracting means for separating an arterial pulse wave component and extracting a cuff pressure and an arterial pulse wave component, respectively. The area of a portion surrounded by a reference line passing through the starting point and having a constant slope and a curve indicating a change in cuff pressure is extracted as an arterial pulse wave component. The necessary arterial pulse wave component It can be without extraction.

According to a twenty-second aspect of the present invention, in the second aspect of the present invention, the arterial pulse wave extracting means uses a straight line connecting the starting points of two adjacent arterial pulse waves as a reference line for the next arterial pulse wave. As a feature, in addition to the effect of the invention of claim 2,
Necessary arterial pulse wave components can be extracted without excess or deficiency.

According to a twenty-third aspect of the present invention, in the twenty-first aspect, the arterial pulse wave extracting means determines the inclination of a straight line connecting a plurality of points indicating the cuff pressure near the start point of the arterial pulse wave to the next arterial pulse wave. And has the same function as the invention of claim 21.

According to a twenty-fourth aspect of the present invention, in the second aspect of the present invention, a cuff to be attached to a main part of a subject to block blood, a pressure means for increasing the pressure in the cuff, and a pressure in the cuff gradually. The pressure in the cuff is superimposed on the cuff pressure from the output of the pressure sensor during the evacuation period in which the pressure in the cuff is converted into an electric signal by the detection means comprising a pressure sensor and the pressure in the cuff is gradually lowered. Biological information extracting means is constituted by cuff pressure extracting means and arterial pulse wave extracting means for extracting an arterial pulse wave component and extracting a cuff pressure and an arterial pulse wave component, respectively. And a filter function for extracting a frequency component corresponding to the arterial pulse wave component from the output of the section. In addition to the function of the invention of claim 2, necessary arterial pulse wave components can be extracted without excess or deficiency. .

According to a twenty-fifth aspect of the present invention, in accordance with the twenty-fourth aspect, the arterial pulse wave extracting means sets the arterial pulse wave as a starting point based on the pressure data, which has a tendency to increase from a predetermined reference level, of the filtered pressure data. It is characterized by extracting components and has the same effect as the invention of claim 24.

According to a twenty-sixth aspect of the present invention, in the fourth aspect, the stratification means performs stratification by comparing with a pattern corresponding to the number of inflection points of the main component. The same effect as that of the invention is achieved.

According to a twenty-seventh aspect of the present invention, in the fourth aspect of the present invention, the stratifying means finds a starting point, an ending point, and a maximum inflection point of the main component, and calculates the area of the triangular portion having these three vertices and the principal component. The present invention is characterized in that stratification is performed by comparing the pattern with a pattern corresponding to the difference between the areas and the same effect as the invention of claim 4.

According to a twenty-eighth aspect of the present invention, in the fourth aspect of the present invention, the stratifying means finds the starting point, the ending point, and the maximum inflection point of the main component, and puts them on a straight line connecting the starting point and the ending point from the maximum inflection point. 5. The method according to claim 4, wherein the stratification is performed by comparing with a pattern corresponding to an area ratio of a main component divided by a perpendicular line.
The same effect as that of the invention is achieved.

The invention of claim 29 is characterized in that, in the invention of claim 4, the stratification means performs stratification by comparing with a pattern according to the presence or absence of a superposition point of the main component. It has the same effect as the invention.

According to a thirtieth aspect of the present invention, in the thirty-ninth aspect of the present invention, the stratification means finds the maximum inflection point and the end point of the main component, and determines a superposition point based on a degree of divergence between the straight line connecting these two points and the main component. It is characterized by determining the presence or absence of the above, and has the same effect as the invention of claim 29.

According to a thirty-first aspect of the present invention, in the thirty-ninth aspect of the present invention, the stratification means finds a starting point, an ending point, and a maximum inflection point of the main component, and puts the starting point and the end point on the straight line connecting the maximum inflection point. 3. The method according to claim 2, wherein the presence or absence of a superimposition point is determined by an area ratio of a main component divided by a perpendicular line.
The same effect as that of the ninth invention is exerted.

According to a thirty-second aspect of the present invention, in the thirty-ninth aspect of the present invention, the stratification means obtains a starting point, an ending point, and a maximum inflection point of the main component, and obtains a center of gravity of a triangular portion having these three points as vertices. Characterized in that the presence or absence of a superimposition point is determined by the area ratio of the main component separated by a straight line substantially parallel to the start point and the end point through the center of gravity,
The same operation as that of the twenty-ninth aspect is achieved.

According to a thirty-third aspect, in the first aspect, the selection means has a plurality of determination reference values as candidates as determination criteria, and the blood pressure determination means includes a determination reference value selected by the selection means. The blood pressure value is determined by comparing with the biological information data, and the same operation as the invention of claim 1 is achieved.

According to a thirty-fourth aspect of the present invention, in the first aspect, when the stratified biometric information data can be stratified into a plurality of layers at the same time, the selection means can select a weight according to a ratio belonging to each layer. Wherein the blood pressure determination means determines the blood pressure value from the weighted biological information data selected by the selection means, and has the same effect as the first aspect of the present invention.

According to a thirty-fifth aspect of the present invention, in the first aspect, when the blood pressure determining means determines the blood pressure value from the biological information data, the area value and the peak value of the biological information data are determined according to the stratified result. The blood pressure value is determined by alternately switching between the two methods, and the same operation as the invention of claim 1 is achieved.

[0042]

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

(Embodiment 1) FIG. 1 shows Embodiment 1 of the present invention.
FIG. 3 is a block diagram showing a control calculation unit 7 in FIG. In addition,
Since the basic configuration including the control calculation unit 7 is common to the conventional example, the common configuration is denoted by the same reference numeral and illustration and description are omitted.

In the arterial pulse wave extracting means 12 and the cuff pressure extracting means 13, the arterial pulse wave component (arterial counter pressure) superimposed on the cuff pressure from the digital signal indicating the cuff pressure input from the A / D converter 6 The cuff pressure is separated from the cuff pressure, and the arterial pulse pressure data Mnm output from the arterial pulse wave extraction means 12 and the cuff pressure data output from the cuff pressure extraction means 13 are sequentially stored in the storage means 14. Then, as shown in FIG. 2A, when the extraction of the arterial reaction pressure data Mnm corresponding to a predetermined number of heartbeats H1 to Hm during the exhaust period is completed, the principal component calculating means 20 is stored in the storage means 14. The main component showing the tendency of the change is obtained from the present artery reaction pressure data Mnm. Here, the approximate heartbeat H1 as shown in FIG.
The matrix X of n rows and m columns each having n × m pieces of arterial reaction pressure data Mnm at the sampling times t1 to tn corresponding to the cycle of... The first main component PC as λ1 to λx
1, the second principal component PC2,..., The xth principal component PCx is obtained. In addition, the ratios (contribution ratios) W1 to Wx of the main components PC1 to all the main components are obtained.

[0045]

(Equation 1) Then, the principal component calculating means 20 pays attention to the principal components having a contribution ratio of 50% or more (for example, the first principal component PC1), and loads the principal component loads PC11 to PCn on the first principal component PC1.
Find 1 The principal component loads PC11 to PCn1 are (X
^T− λI) · t → is shown as a vector t → (see FIG. 2C). Also, sampling times t1 to t
By plotting the principal component loads PC11 to PCn1 corresponding to n with the sampling times t1 to tn plotted on the horizontal axis, load lines as shown in FIGS. 2D and 3 are obtained.

Next, in the stratification means 21, the principal component calculation means 2
Based on the shape of the load line of the first principal component PC1 obtained at 0, the pattern of the arterial reaction pressure data Mnm is classified by comparing the load line pattern stored in the storage unit 14 in advance. Here, the arterial reaction pressure data M in the stratification means 21
The specific procedure for each layer of nm will be described with reference to the flowchart shown in FIG.

The principal component computing means 20 extracts the principal components PC1 to PCx from the arterial reaction pressure data Mnm as the biological information, and loads the principal components having a contribution ratio of 50% or more (for example, the first principal component PC1). Quantity PC11-PCn1
, The stratification means 21 divides the first as shown in FIG.
The number of inflection points of the load line of the main component PC1 is counted, and the number of inflection points is taken as a feature of the arterial pulse wave, and a plurality of patterns stored in the storage means 14 according to the number of inflection points. (The number of inflection points is the same) (classification), and the classification result is given to the selection means 22. Here, the pattern of the main components stored in the storage means 14 is obtained by an experiment in advance for factors considered to affect blood pressure, for example, age, gender, and the like. The method of finding the inflection point is conventionally known, and the point at which the differential value of the principal component load amounts PC11... Becomes zero (the principal component load amount) may be set as the inflection point.

On the other hand, the selection means 22 selects a determination criterion for determining a blood pressure value from the arterial reaction pressure data Mnm from a plurality of candidates according to the given stratified result. For example, in the conventional determination criteria, arterial reaction pressure data that matches a value (threshold) obtained by multiplying the maximum value of the arterial reaction pressure data by a predetermined ratio S [%], D [%] is used as the maximum blood pressure value and the maximum blood pressure value, respectively. Although it is determined as the diastolic blood pressure value, a plurality of types of threshold (determination reference value) candidates are prepared in accordance with factors such as age and gender, and stored in the storage unit 14. The selection unit 22 selects an optimal threshold value according to the stratification result as shown in the flowchart of FIG. 6 and provides the selected threshold value to the blood pressure determination unit 16. Then, the blood pressure determining means 16 obtains a systolic blood pressure value and a diastolic blood pressure value from the arterial reaction pressure data Mnm based on the given threshold value (see FIG. 7).

As described above, the arterial reaction pressure data Mn is obtained from the main components extracted from the artery reaction pressure data Mnm as the biological information.
m, and arterial reaction pressure data Mn according to the stratification result.
By selecting a determination criterion for determining the blood pressure value from m, the measurement error of the blood pressure value due to the difference in the waveform shape of the arterial pulse wave based on individual differences or time differences such as the age and gender of the subject is measured. The blood pressure value can be reduced, and the blood pressure value can be accurately determined. The biological information is not limited to the arterial pulse wave, but may be other information such as a Korotov sound. Further, the layering may be performed only by the first main component PC1 as in the present embodiment, but the second main component PC2 may be used.
Layering may be performed only by the first main component PC1 and the second main component PC2.

(Embodiment 2) In this embodiment, the stratifying means 21
Is characterized in the method of stratifying the arterial reaction pressure data Mnm in the above, and the other configurations and operations are common to the first embodiment. Therefore, illustration and description of the common configurations will be omitted.

The stratifying means 21 of this embodiment calculates the starting point, the ending point, and the maximum inflection point of the load line of the main component, and calculates the difference between the area of the triangular portion having these three vertices and the area of the main component. It is characterized in that it is stratified into any one of a plurality of patterns stored in the storage means 14 accordingly.

The arterial reaction pressure data Mn in the stratification means 21
The specific layer-by-layer procedure of m will be described with reference to the flowchart shown in FIG. Principal component P from the arterial reaction pressure data Mnm as biological information in the principal component calculating means 20
C1 to PCx are extracted, and the principal component load amount P is determined for the principal component (for example, the first principal component PC1) having a contribution ratio of 50% or more.
After calculating C11 to PCn1, the stratification unit 21 determines whether or not FIG.
As shown in the figure, the starting point of the load line of the first main component PC1 (time t
0, the end point (time tn)
And the maximum inflection point (for example, PCk1) corresponding to the three principal points PC11 and Pk.
The difference between the area of the triangular portion having the vertices of Cn1 and PCk1 and the area of the main component PC1 (the area enclosed by the straight line connecting the start point PC11 and the end point PCn1 and the load line) (hereinafter, referred to as “deviation degree”) is obtained. . This divergence is, for example, as shown in FIG.
This is indicated by the hatched portion in (b). Then, the obtained degree of divergence is taken as a characteristic of the arterial pulse wave, and stratified into any of a plurality of patterns (equal in degree of divergence) stored in the storage means 14 according to the degree of divergence. The result is given to the selection means 22. Here, the pattern of the main component stored in the storage unit 14 is obtained in advance by an experiment, as in the first embodiment. Further Embodiment 1
In the same manner as described above, the optimum threshold value is selected by the selection means 22 according to the stratification result given from the stratification means 21, and the systolic blood pressure value and the diastolic blood pressure value are determined by the blood pressure determination means 16 based on the selected threshold value. A value is required.

(Embodiment 3) In this embodiment, the stratifying means 21 is used.
Is characterized in the method of stratifying the arterial reaction pressure data Mnm in the above, and the other configurations and operations are common to the first embodiment. Therefore, illustration and description of the common configurations will be omitted.

The stratifying means 21 of this embodiment finds the starting point, the ending point and the maximum inflection point of the load line of the main component, and is divided by a perpendicular drawn on a straight line connecting the starting point and the ending point from the maximum inflection point. It is characterized in that it is stratified into one of a plurality of patterns stored in the storage means 14 according to the area ratio of the main component.

The arterial reaction pressure data Mn in the stratification means 21
A specific procedure for each layer of m will be described with reference to a flowchart shown in FIG. The principal component calculating means 20 extracts the principal components PC1 to PCx from the arterial reaction pressure data Mnm as the biological information, and calculates the principal component load P for the principal component (for example, the first principal component PC1) having a contribution ratio of 50% or more.
After obtaining C11 to PCn1, the stratifying means 21 performs the processing shown in FIG.
As shown in FIG. 1, the start point of the load line of the first principal component PC1 (the principal component load amount PC11 corresponding to the time t0) and the end point (the time t
n, and the maximum inflection point (for example, PCk1) is obtained, and the area S1 of a portion divided by a perpendicular drawn from the maximum inflection point PCk1 to a straight line connecting the start point PC11 and the end point PCn1 , S1 ratio S1 / S
2, and a time width T1 (= tk−t0) corresponding to each part,
T2 (= tn-tk) is obtained (see FIG. 11B). Then, the obtained area ratio S1 / S2 and time width T1,
The parameter of T2 is grasped as a feature of the arterial pulse wave, and stratified into any one of a plurality of patterns (the area ratio S1 / S2 and the time widths T1 and T2 are equal) stored in the storage means 14 according to both. And the stratification result is selected by means 2
Give to 2. Here, the pattern of the main component stored in the storage unit 14 is obtained in advance by an experiment, as in the first embodiment. Further, in the same manner as in the first embodiment, the optimum threshold value is selected by the selection unit 22 according to the stratification result given from the stratification unit 21, and the systolic blood pressure is determined by the blood pressure determination unit 16 based on the selected threshold value. A value and a diastolic blood pressure value are determined.

(Embodiment 4) In this embodiment, the stratifying means 21 is used.
Is characterized in the method of stratifying the arterial reaction pressure data Mnm in the above, and the other configurations and operations are common to the first embodiment. Therefore, illustration and description of the common configurations will be omitted.

The stratification means 21 of this embodiment is characterized in that stratification is performed into one of a plurality of patterns stored in the storage means 14 in accordance with the presence or absence of a superimposition point on the load line of the main component.

The arterial reaction pressure data Mn in the stratification means 21
A specific procedure for each layer of m will be described with reference to a flowchart shown in FIG. The principal component calculating means 20 extracts the principal components PC1 to PCx from the arterial reaction pressure data Mnm as the biological information, and calculates the principal component load P for the principal component (for example, the first principal component PC1) having a contribution ratio of 50% or more.
After obtaining C11 to PCn1, the stratifying means 21 performs the processing shown in FIG.
As shown in FIG. 3, the presence / absence of a superimposition point K on the load line of the first principal component PC1 is determined. Here, the superposition point K means an inflection point other than the maximum inflection point among the maximum points. Then, the presence / absence of the superposition point K is grasped as a feature of the arterial pulse wave, and any one of the plurality of patterns (with or without the superposition point K) stored in the storage unit 14 is determined according to the presence / absence of the superposition point K. In addition to stratification, the stratification result is provided to the selection means 22. Here, the pattern of the main component stored in the storage unit 14 is obtained in advance by an experiment, as in the first embodiment. Further, in the same manner as in the first embodiment, the stratifying means 21
The optimum threshold value is selected by the selecting means 22 according to the stratification result given from the above, and the systolic blood pressure value and the diastolic blood pressure value are obtained by the blood pressure determining means 16 based on the selected threshold value.

(Embodiment 5) In this embodiment, the stratifying means 21 is used.
Is characterized by a method of determining the presence or absence of a superimposition point in a load line of a main component, and other configurations and operations are common to the first and fourth embodiments. Therefore, illustration and description of common configurations are omitted.

The stratifying means 21 of this embodiment finds the maximum inflection point and the end point in the load line of the main component, and determines the presence or absence of a superposition point based on the degree of deviation between the straight line connecting these two points and the main component. There is a feature.

The procedure for determining the presence / absence of a superimposition point by the stratification means 21 will be described with reference to the flowchart shown in FIG. The principal component calculating means 20 extracts the principal components PC1 to PCx from the arterial reaction pressure data Mnm as the biological information, and loads the principal component loads PC11 to PC11 on the principal components (for example, the first principal component PC1) having a contribution ratio of 50% or more. After determining PCn1, the stratification unit 21 determines the maximum inflection point (for example, PCn) in the load line of the first main component PC1 as shown in FIG.
k1) and the end point PCn1 are obtained, and these two points PCk
The presence or absence of a superimposition point is determined based on the degree of deviation between the load line and the straight line connecting PCn1 and PCn1. Here, the above-mentioned divergence degree is represented by the number of principal component loads showing a value larger than the straight line connecting the two points PCk1 and PCn1, and the principal component showing a value larger than the straight line as shown in FIG. When there are a plurality of load amounts in succession, the load amounts are superimposed points K1, K
2 and K3. Then, according to the presence / absence of the superimposition point K, it is stratified into any one of a plurality of patterns stored in the storage means 14 (with or without the superimposition point K), and the stratification result is sent to the selection means 22. give.

(Embodiment 6) In this embodiment, the stratifying means 21
Is characterized by a method of determining the presence or absence of a superimposition point in a load line of a main component, and other configurations and operations are common to the first and fourth embodiments. Therefore, illustration and description of common configurations are omitted.

The stratifying means 21 of this embodiment finds the starting point, the ending point, and the maximum inflection point in the load line of the main component, and is divided by a perpendicular drawn on a straight line connecting the starting point and the ending point from the maximum inflection point. The feature is that the presence or absence of a superimposition point is determined based on the area ratio of the main components.

The procedure for determining the presence or absence of a superimposition point by the stratification means 21 will be described with reference to the flowchart shown in FIG. The principal component calculating means 20 extracts the principal components PC1 to PCx from the arterial reaction pressure data Mnm as the biological information, and loads the principal component loads PC11 to PC11 on the principal components (for example, the first principal component PC1) having a contribution ratio of 50% or more. After determining PCn1, the stratification means 21 starts the load line of the first main component PC1 (the main component load PC11 corresponding to the time t0) and the end point (the main component corresponding to the time tn) as shown in FIG. Load amount PCn1) and maximum inflection point (for example, PCk1)
From the maximum inflection point PCk1 to the start point PC11 and end point P
2 divided by a perpendicular drawn on a straight line connecting Cn1
The presence or absence of a superimposition point is determined from the ratio S1 / S2 of the areas S1 and S2 of the two parts. That is, in general, the area ratio S1 / S is larger because the area S2 is larger when there is a superimposition point.
2 is reduced, so that when the area ratio S1 / S2 is smaller than a predetermined value, it is determined that there is a superimposition point. Then, according to the presence / absence of the superimposition point K, it is stratified into any one of a plurality of patterns stored in the storage means 14 (with or without the superimposition point K), and the stratification result is sent to the selection means 22. give.

(Embodiment 7) In this embodiment, the stratifying means 21
Is characterized by a method of determining the presence or absence of a superimposition point in a load line of a main component, and other configurations and operations are common to the first and fourth embodiments. Therefore, illustration and description of common configurations are omitted.

The stratifying means 21 of this embodiment finds the starting point, the ending point, and the maximum inflection point in the load line of the main component, finds the center of gravity of a triangular portion having these three points as vertices, and passes the starting point through this center of gravity. And the presence or absence of a superimposition point is determined by the area ratio of the triangular portions separated by a straight line substantially parallel to the end point.

The procedure for determining the presence / absence of a superimposition point by the stratifying means 21 will be described with reference to the flowchart shown in FIG. The principal component calculating means 20 extracts the principal components PC1 to PCx from the arterial reaction pressure data Mnm as the biological information, and loads the principal component loads PC11 to PC11 on the principal components (for example, the first principal component PC1) having a contribution ratio of 50% or more. After obtaining PCn1, the stratifying means 21 starts the load line of the first main component PC1 (the main component load PC11 corresponding to the time t0) and the end point (the main component corresponding to the time tn) as shown in FIG. Load amount PCn1) and maximum inflection point (for example, PCk1)
, And the center of gravity G of the triangular portion having these three points PC11, PCn1, and PCk1 as vertices is obtained. Furthermore, the starting point P
A portion surrounded by a straight line connecting C11 and the end point PCn1 and a load line passes through the center of gravity G and is substantially parallel to a straight line connecting the start point PC11 and the end point PCn1 (dotted line in FIG. 19B).
The ratio S1 / S of the areas S1 and S2 of the two parts separated by
2, the presence or absence of a superimposition point is determined. That is, in general, the area ratio S1 / S2 increases when the superimposition point exists because the area S1 increases, so that the area ratio S1 /
When S2 is larger than a predetermined value, it is determined that there is a superimposition point. Then, according to the presence / absence of the superimposition point K, it is stratified into any one of a plurality of patterns stored in the storage means 14 (with or without the superimposition point K), and the stratification result is sent to the selection means 22. give.

As a stratification method in the stratification means 21, the principal component P obtained by the principal component calculation means 20 is used.
C1 to PCx are used as explanatory variables, and attribute values (age, gender, etc.) that reflect the characteristics of the arterial reaction pressure data Mnm are used as objective variables Y.
.. + XPCx, and stratification may be performed based on the objective variable Y. Here, the coefficients a, b,..., X in the regression equation are obtained in advance and stored in the storage unit 14. Then, the principal components PC1 to P
By substituting Cx into the regression equation, an objective variable Y (for example, the age or gender of the subject) is obtained, and a selection criterion corresponding to the objective variable Y is selected by the selection unit 22 to obtain the blood pressure determination unit 16. In, an accurate blood pressure value corresponding to the attribute value can be obtained. Note that the coefficients a,
Since the method of obtaining b,..., x is well known in the art, the description is omitted.

(Embodiment 8) In this embodiment, the selecting means 22
Is characterized in the method of selecting the determination standard in the first embodiment, and the other configurations and operations are the same as those in the first embodiment. Therefore, illustration and description of the common configurations will be omitted.

When the stratified biometric information data can be stratified into a plurality of layers at the same time, the selecting means 22 of the present embodiment has a weight corresponding to the ratio belonging to each layer as a candidate. The feature is that an appropriate weight is selected from a plurality of candidates according to the stratification result.

In general, when the main component extracted from the arterial reaction pressure data Mnm is stratified into any of a plurality of patterns stored in the storage means 14 in advance, the stratified pattern is divided into any one of the patterns. Since it is often difficult to distinguish the arterial reaction pressure data Mnm, if the main component of the artery reaction pressure data Mnm belongs to two patterns (layers) with a certain probability at the same time, the arterial reaction pressure data By weighting Mnm, a more accurate blood pressure value can be determined.

The procedure of weighting by the selection means 22 will be described with reference to the flowchart shown in FIG.
The principal component calculating means 20 extracts the principal components PC1 to PCx from the arterial reaction pressure data Mnm as the biological information, and the principal component having a contribution ratio of 50% or more (for example, the first principal component PC1).
After calculating the principal component loads PC11 to PCn1 for
The stratification means 21 stratifies the arterial reaction pressure data Mnm by the main component by any of the methods of the first to seventh embodiments. Then, the selection means 22 given the stratification result selects appropriate weighting candidates based on the stratified main component pattern, and selects the appropriate weighting candidates as shown in FIGS. 21 (b) and (c). The arterial reaction pressure data Mnm is weighted. And
Arterial reaction pressure data M weighted by the blood pressure determination means 16
The systolic blood pressure value and the diastolic blood pressure value are obtained from nm in the same manner as in the conventional example.

By weighting the arterial reaction pressure data Mnm according to the stratified result as described above, there is an advantage that the blood pressure with redundancy can be determined.

(Embodiment 9) The basic configuration and operation of this embodiment are the same as those of Embodiment 1, and illustration and description of the common configuration will be omitted.

In this embodiment, when the blood pressure determining means determines the blood pressure value from the arterial reaction pressure data Mnm, the area value and the peak value of the arterial reaction pressure data are selectively switched to determine the blood pressure value. There is a characteristic in that it is performed.

The procedure for determining blood pressure by the blood pressure determining means 16 will be described with reference to the flowchart shown in FIG. The main component calculating means 20 extracts the main components PC1 to PCx from the arterial reaction pressure data Mnm as the biological information,
A main component having a contribution ratio of 50% or more (for example, the first main component PC
After obtaining the principal component loads PC11 to PCn1 for 1), the stratification means 21 classifies the arterial reaction pressure data Mnm by the main component by any of the methods of Embodiments 1 to 7.
Here, since the area value of the arterial reaction pressure data Mnm has a larger amount of information than the peak value, the area value is normally used when determining the blood pressure. There are things that happen. Thus, it is possible to determine from the main component of the arterial reaction pressure data Mnm whether or not there is a high possibility of occurrence of a problem when the determination is made based on the area value. The blood pressure value is determined by selectively switching between the area value and the peak value of the data Mnm.

Thus, accurate blood pressure determination can always be performed regardless of the arterial reaction pressure data Mnm.

(Embodiment 10) By the way, the arterial reaction pressure data Mnm extracted by the arterial pulse wave extracting means 12 includes FIG.
As shown in FIG. 3A, noise may be included, and such noise becomes an error factor in blood pressure determination. Therefore, it is necessary to reduce such noise to improve the S / N ratio. Is needed to determine an accurate blood pressure value.

Therefore, in the present embodiment, when the arterial pulse pressure data Mnm is extracted by the arterial pulse wave extracting means 12, the moving average processing is performed on the arterial pressure data Mnm corresponding to each heartbeat input in time series. Is characterized by performing By performing the moving average process on the arterial reaction pressure data Mnm in this manner, noise can be removed from the arterial reaction pressure data Mnm, and the envelope of the arterial reaction pressure data Mnm is as shown in FIG. It becomes a smooth waveform close to the original arterial pulse wave.
Since the moving average processing is conventionally known, a detailed description thereof will be omitted.

As described above, in the present embodiment, the moving average process is performed on the arterial reaction pressure data Mnm corresponding to each heartbeat input in a time series.
Can be improved. When the arterial pulse wave is extracted by the arterial pulse wave extracting means 12, the differential value of the digital value input from the A / D converter 6 is obtained, and the differential value is used as the arterial reaction pressure data Mnm. However, it is possible to improve the S / N ratio by removing noise.

(Embodiment 11) The present embodiment aims at reducing the calculation load on the principal component calculation means 20.

More specifically, when the main component calculating means 20 obtains the main component from the arterial reaction pressure data stored in the storage means 14, as shown in FIG. The arterial reaction pressure data in the section where the cuff pressure falls almost linearly (the hatched area in FIG. 24 (a)), ignoring the artery reaction pressure data of FIG. The main component is obtained only from the pressure data Mnm.

As described above, the principal component calculating means 20 determines the principal component only from the arterial reaction pressure data Mnm in the section where the cuff pressure can be regarded as falling substantially linearly. The calculation load can be reduced as compared with the case where the main component is obtained from the reaction pressure data, and as a result, the measurement time until finally obtaining the blood pressure value can be reduced.

(Embodiment 12) The present embodiment aims at reducing the calculation load on the principal component calculation means 20.

That is, as shown in FIG.
By increasing the sampling period in the D conversion unit 6, the number of arterial reaction pressure data Mnm is reduced as compared with the case where the sampling period is short as shown in FIG.
As a result, the calculation load on the principal component calculation means 20 can be reduced. As a result, it is possible to reduce the measurement time until finally obtaining the blood pressure value.

The sampling cycle of the A / D converter 6 may be varied according to the importance of the arterial pulse wave. For example, as shown in FIG. 25C, if the sampling period other than the portion corresponding to the vicinity of the systolic blood pressure value and the diastolic blood pressure value in the arterial pulse wave is increased, the entire sampling period is increased as described above. The calculation load can be reduced without reducing the number of data required for measuring the blood pressure value. In order to know a portion corresponding to the vicinity of the systolic blood pressure value and the diastolic blood pressure value in the arterial pulse wave, the blood pressure value may be measured in advance by a conventional procedure as a preliminary measurement, for example.

(Embodiment 13) The present embodiment aims at reducing the calculation load on the principal component calculation means 20.

Specifically, before the actual measurement is started, the systolic blood pressure value and the diastolic blood pressure value (hereinafter referred to as “temporary systolic blood pressure value” and “temporary systolic blood pressure value” In the actual measurement, the cuff pressure in the time periods TS1 and TS2 near the provisional systolic blood pressure value and the provisional diastolic blood pressure value is measured as shown in FIGS. 26 (a) to (c). The arterial pulse wave and cuff pressure are extracted by the arterial pulse wave extracting means 12 and the cuff pressure extracting means 13 only for.

Since the principal component calculating means 20 can determine the principal component from the arterial reaction pressure data Mnm near the tentative systolic blood pressure value and the tentative diastolic blood pressure value of the subject, the calculation load can be reduced. In addition, it is possible to obtain a principal component that more strongly reflects the individual characteristics of the subject, and improve the measurement accuracy of the blood pressure value. Note that a conventionally known means for measuring a blood pressure value based on Korotkoff sound may be provided, and the provisional systolic blood pressure value and the provisional diastolic blood pressure value may be obtained by this measuring means.

(Embodiment 14) The present embodiment aims at reducing the calculation load on the principal component calculation means 20.

More specifically, as in the thirteenth embodiment, preliminary measurement is performed before actual measurement is started, and an arterial pulse wave (maximal arterial pulse wave) having the largest area and the largest peak value is determined. At the time of actual measurement, as shown in FIGS. 27A and 27B, the principal component is calculated by the principal component calculation means 20 from the arterial reaction pressure data in the period TS3 near the maximum arterial pulse wave.

Since the principal component calculating means 20 obtains the principal component from the arterial reaction pressure data Mnm near the maximum arterial pulse wave of the subject, not only the calculation load can be reduced, but also the subject's personal It is possible to obtain a principal component that more strongly reflects the feature, and improve the measurement accuracy of the blood pressure value. A conventionally known means for measuring a blood pressure value based on Korotkoff sound may be provided, and the maximum arterial pulse wave may be determined by this measuring means.

(Embodiment 15) Since the human heartbeat is not constant, the intervals between the arterial pulse waves corresponding to the plurality of heartbeats H1... Do not always match as shown in FIG. The number of the arterial reaction pressure data Mnm corresponding to H1... Thus, even if the main components are obtained from the arterial reaction pressure data in a state where the intervals between the arterial pulse waves are different, it is not possible to extract the proper main components.

Therefore, in the present embodiment, as shown in FIG. 28B, the interval between the arterial pulse waves is unified to a predetermined constant value (preset value) in the principal component calculating means 20, and the number of the arterial reaction pressure data Mnm is increased. Are aligned. For example, the heart rate of a healthy person is usually 30 to 160 / min, and the interval between arterial pulse waves per heart beat is 0.375 to 2.0 seconds. Therefore, the preset value is 0.375 to 2.0 seconds. May be selected (see FIG. 29).

Thus, the principal component calculating means 20 obtains the principal component by unifying the intervals between the arterial pulse waves to a predetermined constant value (preset value) and making the number of the arterial reaction pressure data Mnm uniform. Therefore, it is possible to obtain a principal component that more accurately reflects the characteristics of the subject.

(Embodiment 16) The arterial pulse wave extracting means 12 in this embodiment is adapted to continuously generate a curve (hereinafter, abbreviated as "cuff pressure curve") V indicating a change in cuff pressure as shown in FIG. Pressure values Pv1 and Pv2 at the inflection points C1 and C2 of the arterial pulse waves corresponding to the two heartbeats H1 and H2, and a straight line connecting the two inflection points C1 and C2 and the cuff pressure curve V
Is the starting point of the arterial pulse wave corresponding to the heartbeat H0 following the heartbeats H1 and H2, and the pressure value P at the intersection (starting point) C0
Find v0. Thereby, the starting point of the arterial pulse wave corresponding to each heartbeat H1... Can be easily determined.

The arterial pulse wave extracting means 12 extracts, as an arterial pulse wave component, an area Sc1 of a portion surrounded by a straight line connecting the starting points C1 and C2 of the arterial pulse wave and the cuff pressure curve V. (See FIG. 30). As a result, the starting point C
Necessary data is not removed as compared with the case where the area of a portion surrounded by a straight line horizontal to the time axis and the cuff pressure curve V from C1 and C2 is used as an arterial pulse wave component, and more accurate Blood pressure values can be measured.

Alternatively, the maximum point (peak point) of the arterial pulse wave
The same effect can be obtained by obtaining D1 and D2 and extracting the area Sd1 of a portion surrounded by a straight line connecting the peak points D1 and D2 and a curve indicating a change in cuff pressure as an arterial pulse wave component. Play.

The other configurations and operations are the same as those of the first embodiment, so that illustration and description are omitted.

(Embodiment 17) This embodiment is characterized in that the arterial pulse wave extracting means 12 extracts an arterial pulse wave component. Therefore, the other configurations and operations are the same as those of the first embodiment, and thus illustration and description are omitted.

Hereinafter, the arterial pulse wave extraction processing of the arterial pulse wave extracting means 12 will be specifically described. First, as shown in FIG. 31, the area of a portion surrounded by a straight line connecting the inflection points C1 and C2 on the cuff pressure curve V and the cuff pressure curve V is defined as Sc2. Here, since the slope of the straight line connecting the inflection points C1 and C2 has a negative slope indicating the exhaust speed, the following processing is performed to extract the arterial pulse wave at zero level. That is, the point at which the inflection point C1 is moved in the plus direction of the pressure axis (vertically upward in FIG. 31) to a position parallel to the inflection point C2 (parallel to the time axis in FIG. 31) is defined as C1 ', and the line segment C1C2
Is projected onto a line segment C1′C2, and the area SA of a portion where a portion surrounded by the line segment C1C2 and the cuff pressure curve V is projected.
Is extracted as an arterial pulse wave component.

Alternatively, similar processing may be performed on the peak points D1 and D2 of the arterial pulse wave as described in the sixteenth embodiment. Further, an area obtained by rotating a portion surrounded by the line segment C1C2 and the cuff pressure curve V around the inflection point C2 to a position C1 "where the inflection point C1 becomes parallel to C2 is defined as an arterial pulse wave component. May be extracted.

(Embodiment 18) This embodiment is characterized in that the arterial pulse wave extracting means 12 extracts an arterial pulse wave component. Therefore, the other configurations and operations are the same as those of the first embodiment, and thus illustration and description are omitted.

Hereinafter, the arterial pulse wave extraction processing of the arterial pulse wave extracting means 12 will be specifically described. As shown in FIG. 32, a constant negative slope corresponding to the pumping speed (for example, 3 mmHg / sec)
Is assumed as a straight line (reference line) Ls having
And the area of the region surrounded by the cuff pressure curve V is extracted as the arterial pulse wave component.

(Embodiment 19) Embodiment 18
As described above, when the area of the region surrounded by the reference line Ls and the cuff pressure curve V is extracted as the arterial pulse wave component, the gradient of the exhaust velocity becomes large near the end of the exhaust period, and the arterial pulse wave is increased. The components may not be fully extracted.

Accordingly, the arterial pulse wave extracting means 12 of the present embodiment
In extracting the arterial pulse wave component corresponding to an arbitrary heartbeat Hn, information on the arterial pulse wave component corresponding to the immediately preceding heartbeat Hn−1, for example, as shown in FIG. ,
The inclination of a line segment C1C2 connecting C2 and the area Sc1 of a portion surrounded by the line segment C1C2 and the cuff pressure curve V are used.

Hereinafter, the arterial pulse wave extraction processing of the arterial pulse wave extraction means 12 in the present embodiment will be described in detail. FIG.
As shown in the figure, points C1-1 (t1, Pv1-1) and C2 (t2, Pv1-) on the cuff pressure curve V near the inflection point C1.
2) slope (first derivative) k = (Pv1-2−Pv1-1) /
(T2−t1) is obtained, and the slope k is passed through the next inflection point C0.
Is extracted as an arterial pulse wave component. Thus, when extracting the arterial pulse wave component corresponding to an arbitrary heartbeat, if the information of the arterial pulse wave component corresponding to the previous heartbeat is used, the arterial pulse wave component can be extracted without excess or deficiency. .

(Embodiment 20) As shown in FIG. 35, the pressure value output from the pressure sensor 2 is a curve (cuff pressure curve) in which the arterial pulse wave component is superimposed on the cuff pressure that gradually decreases according to the pumping speed. ) V. Since the cuff pressure curve V includes a change according to the internal pressure of the cuff 1 and the exhaust speed at the time of measuring the blood pressure, there is a possibility that the arterial pulse wave component cannot be accurately extracted.

Therefore, the arterial pulse wave extracting means 12 of this embodiment
36 includes a high-pass filter function for removing low-frequency components (changes according to the internal pressure of the cuff 1 and the exhaust speed during blood pressure measurement) from the digital pressure data output from the A / D converter 6, and FIG. As shown in (1), pressure data from which the low-frequency component has been removed is obtained. Furthermore, arterial pulse wave extraction means 1
2 finds an intersection between the envelope V 'of the pressure data and a reference line (for example, zero level) La as shown in FIG. 36, and points a0, a0,
The processing of extracting the arterial pulse wave component is performed using a1, a2,... as the starting point of the arterial pulse wave. The time interval Ts between the points a0, a1, a2,... Represents one cycle of each arterial pulse wave.

By extracting the arterial pulse wave component by such processing, the arterial pulse wave component can be effectively extracted without excess or deficiency.

[0111]

According to the first aspect of the present invention, there is provided a detecting means for detecting a physical value including biological information, an A / D converting means for converting a detected value of the detecting means from an analog value to a digital value, and an A / D converter.
Biological information extracting means for extracting a component corresponding to biological information from the output of the converting means, storage means for storing the biological information data extracted by the biological information extracting means, and biological information data stored in the storage means as variables. A main component calculating means for calculating one or a plurality of main components, a stratifying means for stratifying biological information data by the main components, and a blood pressure value judging from the biometric data for each stratified layer. Since there is provided a selection unit that selects a determination criterion from among a plurality of candidates, and a blood pressure determination unit that determines a blood pressure value based on biological information data according to the determination criterion selected by the selection unit,
Biological information data is stratified based on the principal components extracted from the biometric information data, and blood pressure values are determined according to criteria determined according to the stratified result. There is an effect that an accurate measurement result can be obtained.

According to the second aspect of the present invention, since the detecting means detects the arterial pulse wave of the subject as the biological information, the same effect as the first aspect of the invention can be obtained.

According to a third aspect of the present invention, the stratification means has a calculation formula for associating the main component with the characteristics of the living body, and performs stratification based on the biological characteristics obtained by the calculation formula. The same effect as that of the invention is achieved.

According to a fourth aspect of the present invention, the stratification means performs stratification by comparing a main component with a plurality of patterns registered in advance and determining whether or not each pattern is substantially equivalent to each pattern. Or, the same effect as that of the second invention can be obtained.

According to a fifth aspect of the present invention, the stratification means performs stratification by using only the first principal component among a plurality of principal components. It works.

According to a sixth aspect of the present invention, the stratifying means performs stratification by using a principal component other than the first principal component among a plurality of principal components. It has the same effect as.

According to the invention of claim 7, since the stratifying means performs stratification by using a plurality of main components, the same effect as any of the inventions of claims 1 to 4 can be obtained.

According to the eighth aspect of the present invention, since means for averaging the arterial pulse wave data corresponding to each heartbeat extracted in time series is provided, the same effect as that of the second aspect of the invention can be obtained. There is an effect that the S / N ratio of the arterial pulse wave data can be improved.

According to the ninth aspect of the present invention, there is provided means for obtaining the data of the arterial pulse wave corresponding to each heartbeat extracted in time series as a change rate in a plurality of minute sections. In addition to the effect, the S / N ratio of the arterial pulse wave data can be improved.

According to a tenth aspect of the present invention, the principal component calculating means includes:
Since the principal component is obtained from a plurality of data sampled from the biological information data, in addition to the effect of the first aspect of the present invention, the effect that the load of the computation processing in the principal component computing means can be reduced. is there.

According to the eleventh aspect of the present invention, since the sampling period in the A / D conversion means is made variable, the load of the arithmetic processing in the principal component arithmetic means can be reduced in addition to the effect of the first aspect. it can.

According to the twelfth aspect of the present invention, the sampling period in the A / D conversion means is varied in accordance with the importance of the biological information. There is an effect that can be obtained.

A thirteenth aspect of the present invention provides a temporary blood pressure determining means for determining a temporary blood pressure value of a subject based on the biological information data stored in the storage means. Since the main component is obtained from the biological information data in the vicinity of the provisional blood pressure value determined in step (1), in addition to the effect of the first aspect of the present invention, there is an effect that the load of the calculation processing in the main component calculating means can be reduced.

According to a fourteenth aspect of the present invention, the principal component calculating means includes:
Since the main component is obtained from the biological information data in the vicinity where the arterial pulse wave shows the maximum value, in addition to the effect of the invention of claim 2, there is an effect that the load of the calculation processing in the main component calculation means can be reduced. .

According to a fifteenth aspect of the present invention, the principal component calculating means includes:
Since the intervals between the arterial pulse waves of each one beat are made substantially constant, there is an effect that necessary arterial pulse wave components can be extracted without excess or deficiency in addition to the effect of the invention of claim 2. .

According to a sixteenth aspect of the present invention, the substantially constant value is set to 0.37
Since the time is set to 5 to 2.0 seconds, the same effect as the invention of claim 15 is obtained.

According to the seventeenth aspect of the present invention, there is provided a cuff which is attached to a main part of a subject to block blood, a pressure means for increasing the pressure in the cuff, and an exhaust means for gradually decreasing the pressure in the cuff. The pressure sensor converts the arterial pulse wave component superimposed on the cuff pressure from the output of the pressure sensor during an evacuation period in which the pressure in the cuff is converted into an electric signal and the pressure in the cuff is gradually decreased by detecting means including a pressure sensor. The biological information extracting means is constituted by a cuff pressure extracting means and an arterial pulse wave extracting means for extracting a cuff pressure and an arterial pulse wave component, respectively.
Since the intersection of the straight line connecting the inflection points of the arterial pulse waves of the continuous arbitrary heartbeats and the curve showing the change of the cuff pressure is set as the start point of the arterial pulse wave, in addition to the effect of the invention of claim 2, necessary There is an effect that the arterial pulse wave component can be extracted without excess or deficiency.

The invention according to claim 18 is characterized in that a cuff to be attached to a main part of a subject to block blood, a pressurizing means for increasing the pressure in the cuff, and an exhaust means for gradually lowering the pressure in the cuff. The pressure sensor converts the arterial pulse wave component superimposed on the cuff pressure from the output of the pressure sensor during an evacuation period in which the pressure in the cuff is converted into an electric signal and the pressure in the cuff is gradually decreased by detecting means including a pressure sensor. The biological information extracting means is constituted by a cuff pressure extracting means and an arterial pulse wave extracting means for extracting a cuff pressure and an arterial pulse wave component, respectively.
Since the area of the part surrounded by the straight line connecting the starting points of the arterial pulse wave and the curve indicating the change of the cuff pressure is extracted as the arterial pulse wave component, it is necessary in addition to the effect of the second aspect of the present invention. There is an effect that a proper arterial pulse wave component can be extracted without excess or deficiency.

According to the nineteenth aspect of the present invention, there is provided a cuff which is attached to a main part of a subject to block blood, a pressure means for increasing the pressure in the cuff, and an exhaust means for gradually lowering the pressure in the cuff. The pressure sensor converts the arterial pulse wave component superimposed on the cuff pressure from the output of the pressure sensor during an evacuation period in which the pressure in the cuff is converted into an electric signal and the pressure in the cuff is gradually reduced by detecting means including a pressure sensor. The biological information extracting means is constituted by a cuff pressure extracting means and an arterial pulse wave extracting means for extracting a cuff pressure and an arterial pulse wave component, respectively.
Since the area of the part surrounded by the straight line connecting the maximum points of the arterial pulse wave and the curve indicating the change in the cuff pressure is extracted as the arterial pulse wave component, in addition to the effect of the invention of claim 2, There is an effect that necessary arterial pulse wave components can be extracted without excess or deficiency.

According to a twentieth aspect of the present invention, the arterial pulse wave extracting means corrects a curve indicating a change in cuff pressure so that a straight line connecting the starting points of arterial pulse wave components or a straight line connecting the maximum points is orthogonal to the pressure axis. Therefore, the same effect as the invention of claim 18 or 19 can be obtained.

According to a twenty-first aspect of the present invention, a cuff which is attached to a main part of a subject to block blood, a pressurizing means for increasing the pressure in the cuff, and an exhaust means for gradually lowering the pressure in the cuff are provided. The pressure sensor converts the arterial pulse wave component superimposed on the cuff pressure from the output of the pressure sensor during an evacuation period in which the pressure in the cuff is converted into an electric signal and the pressure in the cuff is gradually decreased by detecting means including a pressure sensor. The biological information extracting means is constituted by a cuff pressure extracting means and an arterial pulse wave extracting means for extracting a cuff pressure and an arterial pulse wave component, respectively.
The area of a portion surrounded by a reference line passing through the start point of the arterial pulse wave and having a constant slope and a curve indicating a change in cuff pressure is extracted as an arterial pulse wave component. In addition, there is an effect that necessary arterial pulse wave components can be extracted without excess or deficiency.

According to a twenty-second aspect of the present invention, the arterial pulse wave extracting means uses a straight line connecting the starting points of two adjacent arterial pulse waves as a reference line for the next arterial pulse wave. In addition to the above, there is an effect that necessary arterial pulse wave components can be extracted without excess or deficiency.

According to a twenty-third aspect of the present invention, the arterial pulse wave extracting means uses the inclination of a straight line connecting a plurality of points indicating the cuff pressure near the starting point of the arterial pulse wave as the inclination of a reference line with respect to the next arterial pulse wave. Therefore, an effect similar to that of the twenty-first aspect is obtained.

According to a twenty-fourth aspect of the present invention, there is provided a cuff which is attached to a main part of a subject to block blood, a pressure means for increasing the pressure in the cuff, and an exhaust means for gradually lowering the pressure in the cuff. The pressure sensor converts the arterial pulse wave component superimposed on the cuff pressure from the output of the pressure sensor during an evacuation period in which the pressure in the cuff is converted into an electric signal and the pressure in the cuff is gradually decreased by detecting means including a pressure sensor. The biological information extracting means is constituted by a cuff pressure extracting means and an arterial pulse wave extracting means for extracting a cuff pressure and an arterial pulse wave component, respectively.
Since it has a filter function for extracting a frequency component corresponding to an arterial pulse wave component from the output of the A / D converter, in addition to the effect of the invention of claim 2, it is possible to extract necessary and sufficient arterial pulse wave components. There is an effect that can be.

According to a twenty-fifth aspect of the present invention, the arterial pulse wave extracting means extracts an arterial pulse wave component starting from the pressure data which has a tendency to increase from a predetermined reference level among the pressure data after the filter processing. The same effect as that of the twenty-fourth aspect is obtained.

According to the twenty-sixth aspect, the stratification means performs stratification by comparing with a pattern corresponding to the number of inflection points of the main component, so that the same effect as the fourth aspect of the invention is exerted.

According to a twenty-seventh aspect of the present invention, the stratifying means obtains the starting point, the ending point, and the maximum inflection point of the principal component, and calculates the difference between the area of the triangular portion having these three vertices and the area of the principal component. Since the stratification is performed in comparison with the formed pattern, the same effect as the invention of claim 4 can be obtained.

[0138] According to a twenty-eighth aspect of the present invention, the stratification means obtains a starting point, an ending point, and a maximum inflection point of the main component, and is divided by a perpendicular drawn on a straight line connecting the starting point and the ending point from the maximum inflection point. Since the stratification is performed in comparison with the pattern according to the area ratio of the components, the same effect as the invention of claim 4 is exerted.

According to the twenty-ninth aspect of the present invention, since the stratification means performs stratification in comparison with a pattern corresponding to the presence or absence of a superposition point of the main component, the same effect as the fourth aspect of the invention is obtained.

A thirty-third aspect of the present invention is characterized in that the stratifying means obtains the maximum inflection point and the end point of the main component, and determines the presence or absence of a superposition point based on the degree of deviation between a straight line connecting these two points and the main component. Therefore, an effect similar to that of the twenty-ninth aspect is obtained.

According to a thirty-first aspect of the present invention, the stratification means finds a starting point, an ending point, and a maximum inflection point of a main component, and is divided by a perpendicular drawn on a straight line connecting the starting point and the ending point from the maximum inflection point. Since the presence or absence of the superimposition point is determined by the area ratio of the components, the same effect as that of the twenty-ninth aspect is obtained.

According to a thirty-second aspect of the present invention, the stratifying means finds the starting point, the ending point, and the maximum inflection point of the principal component, finds the center of gravity of a triangular portion having these three points as vertices, and passes the starting point and the center through the center of gravity. Since the presence / absence of the superimposition point is determined by the area ratio of the main component separated by a straight line substantially parallel to the end point, the same effect as that of the twenty-ninth aspect is obtained.

According to a thirty-third aspect of the present invention, the selection means has a plurality of determination reference values as candidates as determination criteria, and the blood pressure determination means compares the determination reference value selected by the selection means with the biological information data. Since the blood pressure value is determined by the above method, the same effect as that of the first aspect of the invention can be obtained.

According to a thirty-fourth aspect of the present invention, when the stratified biological information data can be stratified into a plurality of layers at the same time, the selecting means has as a candidate a weight corresponding to the ratio belonging to each layer. Performs the determination of the blood pressure value from the weighted biological information data selected by the selection means, and thus has the same effect as the first aspect of the present invention.

According to a thirty-fifth aspect of the present invention, when the blood pressure determining means determines a blood pressure value from the biological information data, it selectively switches between the area value and the peak value of the biological information data according to the stratified result. Since the blood pressure value is determined by the above method, the same effect as that of the first aspect of the invention can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a main part of a first embodiment.

FIGS. 2A to 2D are explanatory diagrams for explaining the operation of the above.

FIGS. 3A to 3D are explanatory diagrams for explaining the operation of the above.

FIG. 4 is a flowchart for explaining the operation of the above.

FIGS. 5A and 5B are explanatory diagrams for explaining the operation of the above.

FIG. 6 is a flowchart for explaining the operation of the above.

FIGS. 7A and 7B are explanatory diagrams for explaining the operation of the above.

FIG. 8 is a flowchart for explaining the operation of the second embodiment.

FIGS. 9A and 9B are explanatory diagrams for explaining the operation of the above.

FIG. 10 is a flowchart for explaining the operation of the third embodiment.

FIGS. 11A and 11B are explanatory diagrams for explaining the operation of the above.

FIG. 12 is a flowchart for explaining the operation of the fourth embodiment.

FIGS. 13A and 13B are explanatory diagrams for explaining the operation of the above.

FIG. 14 is a flowchart for explaining the operation of the fifth embodiment.

FIGS. 15A and 15B are explanatory diagrams for explaining the operation of the above.

FIG. 16 is a flowchart for explaining the operation of the sixth embodiment.

FIGS. 17 (a) and (b) are explanatory diagrams for explaining the operation of the above.

FIG. 18 is a flowchart for explaining the operation of the seventh embodiment.

FIGS. 19 (a) and (b) are explanatory diagrams for explaining the operation of the above.

FIG. 20 is a flowchart for explaining the operation of the eighth embodiment.

FIGS. 21 (a) and (b) are explanatory diagrams for explaining the operation of the above.

FIG. 22 is a flowchart for explaining the operation of the ninth embodiment.

FIGS. 23 (a) and (b) are explanatory diagrams for explaining the operation of the tenth embodiment.

FIGS. 24A and 24B are explanatory diagrams for explaining the operation of the eleventh embodiment.

FIGS. 25A to 25C are explanatory diagrams for explaining the operation of the twelfth embodiment.

FIGS. 26A and 26B are explanatory diagrams for explaining the operation of the thirteenth embodiment.

FIGS. 27A and 27B are explanatory diagrams for explaining the operation of the fourteenth embodiment.

FIGS. 28A and 28B are explanatory diagrams for explaining the operation of the fifteenth embodiment; FIGS.

FIG. 29 is an explanatory diagram for explaining the above operation.

FIG. 30 is an explanatory diagram for explaining the operation of the sixteenth embodiment.

FIG. 31 is an explanatory diagram for explaining the operation of the seventeenth embodiment.

FIG. 32 is an explanatory diagram for explaining the operation of the eighteenth embodiment.

FIG. 33 is an explanatory diagram for explaining the operation of the nineteenth embodiment.

FIG. 34 is an explanatory diagram for explaining the above operation.

FIG. 35 is an explanatory diagram for explaining the operation of the twentieth embodiment.

FIG. 36 is an explanatory diagram for explaining the above operation.

FIG. 37 is a block diagram showing a conventional example.

FIG. 38 is a block diagram showing a main part of the above.

39 (a) to (d) are explanatory diagrams for explaining the operation of the above.

[Explanation of symbols]

 Reference Signs List 6 A / D conversion section 7 Control calculation section 12 Arterial pulse wave extraction means 13 Cuff pressure extraction means 14 Storage means 16 Blood pressure determination means 20 Principal component calculation means 21 Stratification means 22 Selection means

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Katsuhiko Maruo 1048 Kadoma, Kazuma, Osaka Prefecture Matsushita Electric Works, Ltd. (72) Inventor Masami Oka 1048 Kadoma, Kazuma, Kadoma, Osaka Prefecture Matsushita Electric Works, Ltd. 72) Inventor Ken Hiramatsu 1048 Kadoma Kadoma, Kadoma City, Osaka Prefecture (72) Inventor Shinichi Shinmuro 1048 Kadoma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works Co., Ltd. (72) Tomohiro Izumi Osaka 1048 Kadoma, Kadoma, Fumonma-shi F-term (reference) in Matsushita Electric Works, Ltd. 4C017 AA02 AA08 AA09 AC01 BC11 BD01 FF05 FF08

Claims (35)

[Claims] 1. A detecting means for detecting a physical value including biological information, an A / D converting means for converting a detected value of the detecting means from an analog value to a digital value, and a biological information from an output of the A / D converting means. A biological information extracting unit for extracting a corresponding component, a storing unit for storing the biological information data extracted by the biological information extracting unit, and one or more principal components having the biological information data stored in the storing unit as a variable. A main component calculating means for calculating, a stratifying means for stratifying the biological information data by the main component, and a judgment criterion for judging a blood pressure value from the biometric information data for each stratified layer for a plurality of candidates. A sphygmomanometer, comprising: a selection unit that selects from among them; and a blood pressure determination unit that determines a blood pressure value based on biological information data according to a determination criterion selected by the selection unit. 2. The sphygmomanometer according to claim 1, wherein the detecting means detects an arterial pulse wave of the subject as biological information. 3. The stratification means according to claim 1, wherein the stratification means has a calculation formula for associating the main component with the characteristics of the living body, and performs stratification based on the biological characteristics obtained by the calculation formula. Sphygmomanometer. 4. The stratification means according to claim 1 or 2, wherein said stratification means performs stratification by comparing a main component with a plurality of patterns registered in advance and determining whether or not each pattern is substantially equivalent to each pattern. Sphygmomanometer as described. 5. The stratifying means, wherein the first one of the plurality of main components is
The sphygmomanometer according to any one of claims 1 to 4, wherein stratification is performed using only the main component. 6. The stratifying means includes a first one of a plurality of main components.
The sphygmomanometer according to any one of claims 1 to 4, wherein stratification is performed using a main component other than the main component. 7. The sphygmomanometer according to claim 1, wherein the stratification unit performs stratification using a plurality of main components. 8. The sphygmomanometer according to claim 2, further comprising means for averaging arterial pulse wave data corresponding to each heartbeat extracted in time series. 9. The sphygmomanometer according to claim 2, further comprising: means for obtaining arterial pulse wave data corresponding to each heartbeat extracted in a time series as a rate of change in a plurality of minute sections. 10. The sphygmomanometer according to claim 1, wherein the principal component calculating means obtains a principal component from a plurality of data sampled from the biological information data. 11. The sphygmomanometer according to claim 1, wherein a sampling cycle in the A / D conversion means is variable. 12. The sphygmomanometer according to claim 11, wherein the sampling period in the A / D conversion means is varied according to the importance of the biological information. 13. A temporary blood pressure determining means for determining a temporary blood pressure value of a subject based on biological information data stored in a storage means, wherein the principal component calculating means includes a temporary blood pressure determined by the temporary blood pressure determining means. 2. The sphygmomanometer according to claim 1, wherein a main component is obtained from biological information data near the value. 14. The sphygmomanometer according to claim 2, wherein the principal component calculating means obtains the principal component from the biological information data in the vicinity where the arterial pulse wave shows the maximum value. 15. The sphygmomanometer according to claim 2, wherein the principal component calculation means unifies the intervals of the arterial pulse wave of each one beat to a substantially constant value. 16. The sphygmomanometer according to claim 15, wherein the substantially constant value is 0.375 to 2.0 seconds. 17. A cuff to be attached to a main part of a subject to block blood, pressurizing means for increasing the pressure in the cuff, and exhaust means for gradually lowering the pressure in the cuff. The detection means converts the pressure in the cuff into an electric signal and separates the arterial pulse wave component superimposed on the cuff pressure from the output of the pressure sensor during the evacuation period in which the pressure in the cuff is gradually reduced, thereby separating the cuff pressure and the artery. Biological information extracting means is constituted by cuff pressure extracting means and arterial pulse wave extracting means for extracting pulse wave components, respectively, and the arterial pulse wave extracting means comprises a straight line connecting inflection points of arterial pulse waves of any continuous heartbeat. 3. The sphygmomanometer according to claim 2, wherein an intersection of the curve indicating the change in the cuff pressure is set as a starting point of the arterial pulse wave. 18. A cuff which is attached to a main part of a subject to block blood, pressurizing means for increasing the pressure in the cuff, and exhaust means for gradually decreasing the pressure in the cuff. The detection means converts the pressure in the cuff into an electric signal and separates the arterial pulse wave component superimposed on the cuff pressure from the output of the pressure sensor during the evacuation period in which the pressure in the cuff is gradually reduced, thereby separating the cuff pressure and the artery. A biological information extracting means is constituted by a cuff pressure extracting means for extracting a pulse wave component and an arterial pulse wave extracting means, and the arterial pulse wave extracting means defines a straight line connecting the starting points of the arterial pulse waves and a change in the cuff pressure. 3. The sphygmomanometer according to claim 2, wherein an area of a portion surrounded by the curved line is extracted as an arterial pulse wave component. 19. A cuff which is attached to a main part of a subject to block blood, pressurizing means for increasing the pressure in the cuff, and exhaust means for gradually lowering the pressure in the cuff. The detection means converts the pressure in the cuff into an electric signal and separates the arterial pulse wave component superimposed on the cuff pressure from the output of the pressure sensor during the evacuation period in which the pressure in the cuff is gradually reduced, thereby separating the cuff pressure and the artery. A biological information extracting means is constituted by a cuff pressure extracting means for extracting a pulse wave component and an arterial pulse wave extracting means, and the arterial pulse wave extracting means comprises a straight line connecting the maximum points of the arterial pulse wave and a change in the cuff pressure. 3. The sphygmomanometer according to claim 2, wherein an area of a portion surrounded by a curve indicating the following is extracted as an arterial pulse wave component. 20. The arterial pulse wave extracting means corrects a curve indicating a change in cuff pressure and converts the curve so that a straight line connecting the starting points of arterial pulse wave components or a straight line connecting the maximum points is orthogonal to the pressure axis. 20. The sphygmomanometer according to claim 18 or 19, comprising: 21. A cuff to be attached to a main part of a subject to block blood, pressure means for increasing the pressure in the cuff, and exhaust means for gradually lowering the pressure in the cuff. The detection means converts the pressure in the cuff into an electric signal and separates the arterial pulse wave component superimposed on the cuff pressure from the output of the pressure sensor during the evacuation period in which the pressure in the cuff is gradually reduced, thereby separating the cuff pressure and the artery. Biological information extracting means is constituted by a cuff pressure extracting means for extracting a pulse wave component and an arterial pulse wave extracting means, and the arterial pulse wave extracting means comprises a reference line having a constant slope passing through the starting point of the arterial pulse wave. 3. The sphygmomanometer according to claim 2, wherein an area of a portion surrounded by a curve indicating a change in pressure is extracted as an arterial pulse wave component. 22. The sphygmomanometer according to claim 21, wherein the arterial pulse wave extracting means comprises a straight line connecting the starting points of two adjacent arterial pulse waves as a reference line for the next arterial pulse wave. 23. The arterial pulse wave extracting means, wherein the inclination of a straight line connecting a plurality of points indicating the cuff pressure near the starting point of the arterial pulse wave is defined as the inclination of a reference line for the next arterial pulse wave. A blood pressure monitor according to claim 21. 24. A pressure sensor comprising: a cuff to be attached to a main part of a subject to block blood; pressurizing means for increasing the pressure in the cuff; and exhaust means for gradually lowering the pressure in the cuff. The detection means converts the pressure in the cuff into an electric signal and separates the arterial pulse wave component superimposed on the cuff pressure from the output of the pressure sensor during the evacuation period in which the pressure in the cuff is gradually reduced, thereby separating the cuff pressure and the artery. Biological information extracting means is constituted by cuff pressure extracting means and arterial pulse wave extracting means for extracting pulse wave components, respectively, and the arterial pulse wave extracting means obtains a frequency corresponding to the arterial pulse wave component from the output of the A / D converter. 3. The sphygmomanometer according to claim 2, wherein the sphygmomanometer has a filter function for extracting components. 25. The arterial pulse wave extracting means, wherein the arterial pulse wave component is extracted by using, as a starting point, pressure data having a tendency to increase from a predetermined reference level in the pressure data after the filtering process. Item 24. The blood pressure monitor according to Item 24. 26. The sphygmomanometer according to claim 4, wherein the stratification means performs stratification by comparing with a pattern corresponding to the number of inflection points of the main component. 27. The stratification means finds a starting point, an ending point, and a maximum inflection point of the main component, and compares the starting point, the ending point, and the maximum inflection point with a pattern corresponding to the difference between the area of the triangular portion having these three vertices and the area of the main component. 5. The sphygmomanometer according to claim 4, wherein stratification is performed. 28. The stratification means finds a starting point, an ending point, and a maximum inflection point of the main component, and calculates an area ratio of the main component divided by a perpendicular drawn on a straight line connecting the starting point and the ending point from the maximum inflection point. 5. The sphygmomanometer according to claim 4, wherein stratification is performed by comparing with a corresponding pattern. 29. The sphygmomanometer according to claim 4, wherein the stratification means performs stratification by comparing with a pattern according to the presence or absence of a superposition point of the main component. 30. The stratification means, wherein a maximum inflection point and an end point of the main component are obtained, and the presence or absence of a superposition point is determined based on the degree of deviation between a straight line connecting these two points and the main component. A sphygmomanometer according to claim 29. 31. The stratification means obtains a starting point, an ending point, and a maximum inflection point of the main component, and calculates an area ratio of the main component divided by a perpendicular drawn on a straight line connecting the starting point and the ending point from the maximum inflection point. 30. The sphygmomanometer according to claim 29, wherein the presence or absence of a superimposition point is determined. 32. The stratification means obtains a starting point, an ending point, and a maximum inflection point of the principal component, obtains a center of gravity of a triangular portion having these three points as vertices, and forms a straight line connecting the starting point and the ending point through the center of gravity. 30. The sphygmomanometer according to claim 29, wherein the presence / absence of a superimposition point is determined by an area ratio of a main component separated by a substantially parallel straight line. 33. The selection means has a plurality of determination reference values as candidates as determination criteria, and the blood pressure determination means compares the determination reference value selected by the selection means with the biological information data to determine the blood pressure value. The sphygmomanometer according to claim 1, wherein 34. When the biometric information data stratified can be stratified into a plurality of layers at the same time, the selecting means has as a candidate a weight corresponding to a ratio belonging to each layer. The sphygmomanometer according to claim 1, wherein a blood pressure value is determined from the selected weighted biological information data. 35. The blood pressure determination means, when determining a blood pressure value from the biological information data, selectively switches between the area value and the peak value of the biological information data according to the stratified result, and determines the blood pressure value. The sphygmomanometer according to claim 1, wherein