JP6304651B2 - Cardiovascular function arithmetic unit - Google Patents

Description

  The present invention relates to a circulatory function calculation device.

  The circulatory organ function calculation device of Patent Document 1 includes a compression unit, a pressure detection unit, a pulse wave detection unit, and a feature amount calculation unit. The compression unit compresses the measurement target portion of the measurement subject's body. The pressure detection unit detects the compression pressure generated by the compression unit. The pulse wave detector detects pulse wave information based on an output signal from the pressure detector. The feature amount calculation unit calculates an index of the subject's circulatory function based on the pulse wave information. The feature amount calculation unit matches the pattern portion including the envelope of the pulse wave with the trapezoidal outline pattern. The feature amount calculation unit calculates the value of the upper base of the pattern portion matched to the trapezoid as an index of the circulatory function.

JP 2005-323853 A

  The pulse wave information detected by the circulatory function calculating device is affected by hardware identification, biological characteristics, and measurement environment. Examples of the hard characteristics include characteristics such as a compression part and a pressure detection part. Examples of the biological characteristics include characteristics such as the age of the person to be measured, the size of the measurement unit, the ratio between fat and muscle, sex, and race. Examples of the measurement environment include a positional relationship between the measurement subject and the compression unit, and a change in the measurement posture of the measurement subject. The influence on the pulse wave information due to the hardware characteristics, the biological characteristics, the measurement environment, etc. affects the calculation result. For this reason, there exists a possibility that a calculation result may deviate from an appropriate result according to the actual condition of the person being measured.

On the other hand, by improving the calculation accuracy of the circulatory function calculation device, it is possible to reduce the possibility that the calculation result will deviate from an appropriate result due to the influence of hardware characteristics, biological characteristics, measurement environment, and the like.
The circulatory function calculating device uses only the value of the upper base of the pattern portion of the pulse wave information matched to the trapezoid, and does not consider other characteristic portions of the pulse wave information. On the other hand, the pulse wave information reflects the circulatory function also in other characteristic portions. For this reason, there is room for improvement in the calculation accuracy of the index of the cardiovascular function.

  The present invention was created based on the above background, and an object of the present invention is to provide a circulatory function calculation device that can improve the calculation accuracy of a circulatory function index.

  The means includes: a “compression unit that compresses a measurement unit of the body of the measurement subject, a pressure detection unit that detects a compression pressure generated by the compression unit, a pressure control unit that changes the compression pressure, and the pressure A pulse wave detection unit that detects pulse wave information based on an output signal from the pressure detection unit in the process of changing the compression pressure by the control unit, calculates a variable value from the pulse wave information, and performs multivariate analysis in advance. A circulatory function computing device comprising: a feature quantity computing unit that computes a feature quantity that serves as an index of a circulatory function by substituting the variable value into an arithmetic expression having a plurality of obtained variables and coefficients "including.

  The feature amount calculation unit determines the circulatory function by substituting a plurality of variable values obtained from the pulse wave information into an arithmetic expression having a plurality of variables and coefficients obtained in advance by multivariate analysis. For this reason, the calculation accuracy of the index of the circulatory function can be improved.

  One form of the above means is that “the pulse wave information has a plurality of pulse waves in the process of changing the compression pressure, and the feature amount calculation unit calculates values related to the plurality of pulse waves as the variable values. A circulatory function computing device ".

One form of the above means includes "the circulatory function computing device in which the feature quantity computing unit computes the amplitude of each of the plurality of pulse waves as the variable value".
One mode of the above means includes “the circulatory function computing device in which the feature quantity computing unit computes the widths of the plurality of amplitudes as the variable values”.

One mode of the above means includes “the circulatory function calculation device that calculates the width of each of the plurality of pulse waves as the variable value”.
One form of the above means is that “the feature amount is an index corresponding to a discriminant value for discriminating a state related to a specific disease related to the cardiovascular function, and the feature amount computing unit includes the feature amount and the discriminant value The cardiovascular function computing device for discriminating the condition relating to the specific disease of the subject.

  One form of the above means is that “the computing equation is obtained in advance by principal component analysis as multivariate analysis, and the feature quantity computing unit computes the feature quantity as a value for the principal component, A circulatory function computing device for determining the circulatory function.

  One form of the means is as follows: “The feature amount calculation unit calculates envelopes of the plurality of pulse waves with respect to a change in the compression pressure, and uses the envelopes for each predetermined change amount of the compression pressure or the pulse wave. And a circulatory function calculating device that uses the divided value relating to the envelope as the variable value.

  This circulatory function calculation device can improve the calculation accuracy of the circulatory function index.

The schematic diagram of the circulatory function calculating apparatus of embodiment. The graph which showed the relationship between the compression pressure detected by the pressure detection part of embodiment, and time. The graph which showed the relationship between the cuff pressure detected by the pulse wave detection part of embodiment, and a pulse wave. The graph which showed the relationship between the cuff pressure detected by the pulse wave detection part of embodiment, and a pulse wave area. The graph which showed the relationship between the pulse wave order detected by the pulse wave detection part of embodiment, and a pulse wave area. The schematic diagram which shows an example of the determination result of the circulatory function displayed on the display part of embodiment.

With reference to FIG. 1, the structure of the circulatory function calculating device 1 will be described.
The circulatory function calculation device 1 includes a compression unit 10, a pressure control unit 20, a pressure detection unit 30, a pulse wave detection unit 40, a feature amount calculation unit 50, a blood pressure calculation unit 90, and a display unit 100.

  The compression unit 10 includes a cuff 11 and a tube 12. The cuff 11 is wound around the upper arm as a part to be measured of the body of the person to be measured. The cuff 11 expands when air is supplied to the inside thereof and presses the arm of the measurement subject. The tube 12 connects the cuff 11 to an air pump (not shown) of the pressure control unit 20 and an air discharge valve (not shown).

  The pressure control unit 20 changes the pressure inside the cuff 11 (hereinafter, “compression pressure P”) by controlling the supply and discharge of air to the compression unit 10. The pressure control unit 20 includes an air pump (not shown) and an air discharge valve (not shown). When increasing the compression pressure P, the pressure control unit 20 drives the air pump to supply air to the cuff 11. When the pressure control unit 20 decreases the compression pressure P, the pressure control unit 20 opens the discharge valve and discharges air from the cuff 11.

  The pressure detection unit 30 detects the compression pressure P when the compression unit 10 compresses the upper arm of the measurement object. The pressure detection unit 30 includes a pressure sensor (not shown) and an A / D converter (not shown). The pressure detection unit 30 converts the compression pressure P of the compression unit 10 detected by the pressure sensor into a pressure signal composed of a digital signal by an A / D converter. The pressure signal converted by the pressure detection unit 30 is output to the pulse wave detection unit 40 and the blood pressure calculation unit 90.

  The pulse wave detector 40 detects pulse wave information based on the pressure signal from the pressure detector 30. The pulse wave detection unit 40 includes a filter circuit (not shown). The pulse wave detector 40 generates a pulse wave signal by removing a predetermined frequency component such as a direct current component from the output signal from the pressure detector 30 in the filter circuit, and the amplitude of the pulse wave from the generated pulse wave signal Is detected. The pulse wave detector 40 outputs the detected amplitude signal of the pulse wave to the feature amount calculator 50.

  The feature amount calculation unit 50 includes a pulse wave information storage unit 60, a variable value calculation unit 70, and a circulatory function determination unit 80. The pulse wave information storage unit 60 stores the amplitude signal from the pulse wave detection unit 40 in the pulse wave information storage unit 60 in association with the compression pressure P. The variable value calculation unit 70 calculates a variable value from the amplitude of the pulse wave stored in the pulse wave information storage unit 60. The circulatory function determination unit 80 substitutes the variable value calculated by the variable value calculation unit 70 into a predetermined calculation formula to determine the circulatory function of the measurement subject. The circulatory function determination unit 80 outputs the determination result of the subject's circulatory function to the display unit 100.

  The blood pressure calculation unit 90 uses a predetermined algorithm such as an oscillometric method based on the relationship between the compression pressure P detected by the pressure detection unit 30 and the amplitude value of the pulse wave detected by the pulse wave detection unit 40. An estimate of the measurer's systolic blood pressure, diastolic blood pressure, and mean blood pressure is calculated. The blood pressure calculation unit 90 outputs the blood pressure calculation result to the display unit 100.

  The display unit 100 has a liquid crystal screen. The display unit 100 displays the determination result of the circulatory function determining unit 80 on the liquid crystal screen, and the measured values of the highest blood pressure, the lowest blood pressure, and the average blood pressure calculated by the blood pressure calculating unit 90.

With reference to FIGS. 2-6, the determination process of a circulatory function is demonstrated.
As shown in FIG. 2, when determining the circulatory function, the pressure control unit 20 changes the compression pressure P. Specifically, the pressure control unit 20 increases the compression pressure P to the first pressure PA. That is, the pressure control unit 20 supplies air to the compression unit 10 to expand the cuff 11. The pressure control unit 20 increases the compression pressure P to the first pressure PA, and then decreases the increase speed of the compression pressure P. The pressure control unit 20 increases the compression pressure P to the second pressure PB higher than the first pressure PA, and then decreases the compression pressure P. That is, the pressure control unit 20 discharges air from the cuff 11.

  The first pressure PA and the second pressure PB are set according to general blood pressure. Therefore, the compression pressure P detected by the pressure detection unit 30 during the period in which the pressure control unit 20 increases the compression pressure P from the first pressure PA to the second pressure PB (hereinafter, “pulse wave detection period TX”) is Fluctuates with the pulse wave W.

  As shown in FIG. 3, the change in the compression pressure P relative to the change in the pressure of the compression unit 10 (hereinafter, “cuff pressure C”) corresponding to the amount of air supplied to the compression unit 10 in the pulse wave detection period TX is Corresponds to the pulse wave W. The cuff pressure C corresponds to a value obtained by removing the influence of the pulse wave W from the compression pressure P. The pulse wave signal detected by the pulse wave detector 40 corresponds to a change in the compression pressure P with respect to the cuff pressure C.

  The pulse wave W reflects the change in the blood vessel volume corresponding to the blood pressure difference between the inside and outside of the blood vessel. For this reason, it is thought that it is comprised by the complex information containing blood pressure, a circulatory organ function, and the mechanical function of a biological body. The feature amount calculation unit 50 calculates the circulatory function from the pulse wave W by extracting optimal information corresponding to the target circulatory function from a large amount of information obtained from the pulse wave W.

  The variable value calculation unit 70 obtains information associating the area of the pulse wave W in each pulse wave W (hereinafter referred to as “pulse wave area A”) and the cuff pressure C from the information stored in the pulse wave information storage unit 60. Calculate as a variable value. The pulse wave area A of each pulse wave W is the magnitude of each pulse wave W and corresponds to the amplitude of each pulse wave W.

  The pulse wave area A is calculated by adding pulse wave signals during a period in which one pulse wave W is detected. When n pulse waves W are detected in the pulse wave detection period TX, A1 is a pulse wave area A1 indicating the magnitude of the pulse wave detected first, and A2 is a pulse wave area A detected second. The nth pulse wave area A is An. Hereinafter, the order of the pulse wave W corresponding to the increase in the cuff pressure C is set to pulse waves W1, W2,..., Wn, and the pulse wave area A of the pulse waves W1, W2,. Shown as An.

  As shown in FIG. 4, an envelope L is obtained from the relationship between the change in the cuff pressure C and the pulse wave area A. The pulse wave area A shows a characteristic change according to the slow pressurization of the compression part 10. For this reason, the envelope L draws a mountain shape. It is known that the envelope L has a characteristic shape depending on the individual and further changes in shape due to various circulatory diseases.

  The circulatory function determining unit 80 treats the output from the variable value calculating unit 70 as a data pair that combines the order of the cuff pressure C and the area of the pulse wave W. As shown in FIG. 5, the data pair includes coordinates “(W1, A1), (W2, A2),..., (Wn,) combining the pulse wave order (Wn) and the area (An) of the pulse wave W. An) ”. Thus, by making the order of the pulse waves W one variable, a plurality of data pairs of pulse wave information can be acquired. The variable value calculation unit 70 outputs the data pair as a variable value to the circulatory function determination unit 80.

  The circulatory function determination unit 80 substitutes the variable values calculated by the variable value calculation unit 70 into the following formulas (1) and (2), which are preset calculation formulas, and the feature value Z11 and the feature value Z21. Is calculated.

Z11 = a11 × A1 + a12 × A2 +... + A1n × An (1)
Z21 = a21 × A1 + a22 × A2 +... + A2n × An (2)
The feature amount Z11 quantitatively indicates the degree of blood vessel hardness Z1 as an index of the blood vessel state.

The feature amount Z21 quantitatively indicates the clogging degree Z2 of the blood vessel as an index of the blood vessel state.
The coefficients “a11, a12... A1n” for calculating the feature value Z11 of the equation (1) and the coefficients “a21, a22... A2n” for calculating the feature value Z21 of the equation (2) are preliminarily subjected to multivariate analysis. As determined by principal component analysis.

  As shown in FIG. 6, the circulatory function determining unit 80 includes the feature amount Z11 calculated by the equations (1) and (2) on the graph S having the feature amount Z1 axis and the feature amount Z2 axis. By plotting the feature value Z21, it is determined which of the four groups the circulatory function of the measurement subject belongs.

  In the first quadrant (region R1) of the graph S, the degree of blood vessel hardness Z1 is greater than a value with a low possibility of disease (hereinafter, “standard value”), and the degree of blood vessel clogging Z2 is higher than the standard value. (Cardiovascular high risk group).

The second quadrant (region R2) of the graph S indicates a state where the degree of blood vessel hardness Z1 is smaller than the standard value and the degree of blood vessel clogging Z2 is higher than the standard value (blood vessel clogging risk group).
The third quadrant (region R3) of the graph S indicates a state where the degree of blood vessel hardness Z1 is smaller than the standard value and the degree of blood vessel clogging Z2 is lower than the standard value (normal cardiovascular group).

The fourth quadrant (region R4) of the graph S indicates a state (blood vessel hardness risk group) in which the degree of blood vessel hardness Z1 is higher than the standard value and the degree of blood vessel clogging Z2 is lower than the standard value.
The display unit 100 plots and displays the feature value Z11 and the feature value Z21 calculated by the circulatory organ function determination unit 80 on the graph S.

A principal component analysis method for determining the coefficients of the equations (1) and (2) will be described.
Each coefficient is obtained by using cuffs obtained from a plurality of subjects having different blood vessel states using the compression unit 10, the pressure control unit 20, the pressure detection unit 30, and the pulse wave detection unit 40 of the circulatory function computing device 1. Principal component analysis is performed using a data string “(W1, A1), (W2, A2),..., (Wn, An)” that combines the order of pressure C (Wn) and the area (An) of pulse wave W. To obtain.

Specifically, an operation for calculating the first principal component and the principal components equal to or less than the second principal component using the data string “(W1, A1), (W2, A2),..., (Wn, An)”. Guide the formula.
Next, a data string obtained from a plurality of subjects is substituted into an arithmetic expression for computing each principal component, and a score of each principal component of each subject is computed.

Next, a scatter diagram is created using the score of each principal component of each person to be measured.
Next, the meaning of each principal component is given from the scatter diagram.
The meaning of the main component will be described.

  When the principal component X of the first to n-th principal components obtained by the principal component analysis tends to comprehensively indicate the hardness of the blood vessel as the blood vessel state, the principal component X is used as an index of the blood vessel hardness. To do. For this reason, an arithmetic expression for obtaining the score of the principal component X is represented by Expression (1). Also, “a11, a12... A1n” is determined as a coefficient for calculating the feature quantity Z1, which is an index of blood vessel hardness. Note that when there is a tendency to comprehensively indicate the hardness of the blood vessel, for example, the higher the principal component X score, the higher the blood pressure and the faster the pulse wave propagation speed (PWV), The principal component X can be meant as a tendency to comprehensively indicate the hardness of the blood vessel.

  When the principal component Y among the plurality of principal components among the first to n-th principal components obtained by the principal component analysis tends to comprehensively indicate the clogging condition of the blood vessel as the blood vessel state, It is an index of the degree of clogging. For this reason, an arithmetic expression for obtaining the score of the principal component Y is represented by Expression (2). Further, the coefficients “a21, a22... A2n” are determined as coefficients for calculating the feature amount Z1 that is an index of the degree of clogging of blood vessels. Note that when there is a tendency to comprehensively indicate the degree of clogging of blood vessels, for example, the higher the score of the main component Y, the higher the blood cholesterol level and the higher the obesity level, Y can be defined as a tendency to comprehensively indicate the degree of clogging of blood vessels.

The circulatory function computing device 1 has the following effects.
(1) The feature quantity calculation unit 50 uses a plurality of variable values obtained from the pulse wave information as variables of the expressions (1) and (2) having a plurality of variables and coefficients obtained in advance by multivariate analysis. Substitute and determine cardiovascular function. For this reason, the calculation accuracy of the feature quantity Z11 and the feature quantity Z21 as an index of the circulatory function can be improved.

  (2) The feature amount calculation unit 50 uses the pulse wave area A as a variable value. For this reason, it becomes stronger against data noise than when the peak height of the pulse wave W is used as a variable value. For this reason, the calculation accuracy of the feature value Z11 and the feature value Z21 of the circulatory function can be improved.

  (3) The circulatory function computing device 1 makes the air supplied to the cuff 11 in the pulse wave detection period TX a slight pressurization. For this reason, it is possible to measure the state before the blood vessel is blocked by the compression of the upper arm by the cuff 11. For this reason, it is possible to detect the pulse wave W in a more natural state of the blood vessel as compared with the configuration in which the pulse wave W is detected while reducing the pressure. For this reason, the calculation accuracy is improved.

  (4) The feature amount calculation unit 50 uses the order of the pulse waves W as one variable in the data pair. The pulse wave W appears at different timing depending on the individual. For this reason, even different persons to be measured can be easily calculated. For this reason, it is possible to reduce the calculation load as compared with the configuration in which the timing at which the pulse wave W appears or the width of the pulse wave W is a variable.

  (5) The feature amount calculation unit 50 uses the pulse wave area A as one variable in the data pair. For this reason, much pulse wave information can be obtained compared with the case where the heart rate using the electrode or microphone which measures an electrocardiogram is used. For this reason, the accuracy in multivariate analysis is improved, and it is more resistant to noise. In addition, reproducibility is improved.

  (6) The feature amount calculation unit 50 uses all the pulse waves W in the pulse wave detection period TX as variables. For this reason, compared with the case where some pulse waves W in the pulse wave detection period TX are used, the calculation accuracy of the circulatory function can be improved.

  (7) The circulatory function computing device 1 uses principal component analysis as multivariate analysis. For this reason, the fluctuation | variation which a multivariable has can be decreased. For this reason, a more robust feature amount can be extracted.

  (8) The feature quantity computing unit 50 can determine the circulatory function with a two-dimensional graph by extracting the two feature quantities Z11 and Z21. Therefore, the feature quantities Z11 and Z21 and the cardiovascular function group can be displayed simultaneously. For this reason, it is easy for the measurement subject to understand.

  (9) The display unit 100 has a liquid crystal screen. For this reason, a result can be read directly from the inside of the feature amount calculation unit 50. For this reason, the determination result of the circulatory function can be quickly displayed.

  (10) The circulatory function computing device 1 uses multivariate analysis as quantitative analysis. For this reason, the circulatory function can be calculated as a numerical value. For this reason, the circulatory function can be expressed by the graph S. For this reason, the person being measured can easily grasp the level of the cardiovascular function.

(Other embodiments)
This circulatory function calculating device includes embodiments other than the above-described embodiment. Hereinafter, the modification of the said embodiment as other embodiment of this circulatory function calculating apparatus is shown. The following modifications can be combined with each other.

The feature amount calculation unit 50 according to the embodiment determines the circulatory function using the pulse wave area A as a variable value. However, the configuration of the feature amount calculation unit 50 is not limited to this. For example, the feature quantity calculation unit 50 of the modification example determines the circulatory function using any of the following (G1) to (G4) as a variable value.
(G1) The peak size of each pulse wave W.
(G2) A change amount of the cuff pressure C in each pulse wave W.
(G3) A change amount of the pulse wave W when the envelope L is divided for each predetermined change amount of the cuff pressure C.
(G4) A change amount of the cuff pressure C when the envelope L is divided for each predetermined change amount of the pulse wave W.

  (G1) corresponds to the amplitude of each pulse wave W. A value corresponding to the amplitude of each pulse wave W other than (G1) can also be adopted as the variable value. (G2) corresponds to the width of each pulse wave W. A value corresponding to the width of each pulse wave W other than (G2) can also be adopted as a variable value.

  -The feature-value calculating part 50 of embodiment calculates the feature-values Z11 and Z21 which show the parameter | index of a blood vessel state quantitatively. However, the configuration of the feature amount calculation unit 50 is not limited to this. For example, the feature amount calculation unit 50 according to the modification calculates a feature amount qualitatively indicating a blood vessel state index. In this case, the feature amounts Z1 and Z2 are calculated as indicators corresponding to the discriminant value for discriminating the state relating to the specific disease relating to the cardiovascular function. An arithmetic expression that can be compared with a discriminant value is used. For example, an arithmetic expression for discriminant analysis is used. In this case, the display unit 100 indicates that the result of the discriminant analysis, that is, the state relating to the specific disease related to the subject's cardiovascular function is “risk higher than the reference value” and “risk lower than the reference value”. One is displayed by character information.

  The feature amount calculation unit 50 according to the embodiment calculates the feature amounts Z11 and Z21 using principal component analysis. However, the configuration of the feature amount calculation unit 50 is not limited to this. For example, the feature amount calculation unit 50 according to the modification calculates the feature amounts Z11 and Z21 using multiple regression analysis. In this case, an arithmetic expression obtained in advance by multiple regression analysis is used as the arithmetic expression. Thereby, the optimal regression model of the objective variable can be created from a plurality of explanatory variables. For this reason, an accurate calculation value can be obtained. A canonical correlation analysis can be used instead of the multiple regression analysis. In this case, a coefficient that maximizes the correlation can be calculated for a plurality of cardiovascular functions. For this reason, it is possible to extract feature quantities that more accurately represent individual cardiovascular functions.

  -The circulatory function calculating apparatus 1 of embodiment displays the determination result of a circulatory function by the plot on the graph S. FIG. However, the configuration of the circulatory function computing device 1 is not limited to this. For example, the circulatory function computing device 1 according to the modified example displays the determination result of the circulatory function as character information or voice information. Examples of the character information include “is a high risk area for arteriosclerosis”. Further, in this modified example, in addition to the display of the circulatory function area, the circulatory function based on the feature quantities Z11 and Z21 such as “the hardness of the blood vessel is level 4” and “the degree of clogging is level 6”. Level display is possible.

  In the circulatory function calculation device 1 according to the embodiment, the supply of air to the cuff 11 is set to a slight increase in pressure during the pulse wave detection period TX. However, the configuration of the circulatory function computing device 1 is not limited to this. For example, in the circulatory function computing device 1 according to the modification, the supply of air to the cuff 11 is set to a slight pressure increase in the pulse wave detection period TX. Note that the compression pressure P at the start of the pulse wave detection period TX is the second pressure PB, and the compression pressure P at the end of the pulse wave detection period TX is the first pressure PA. In this case, the generation point of the pulse wave clearly appears as compared with the configuration of the slight pressure increase. For this reason, blood pressure can be accurately measured.

  The feature amount calculation unit 50 of the embodiment uses two feature amounts Z11 and Z21. However, the configuration of the feature amount calculation unit 50 is not limited to this. For example, the feature amount calculation unit 50 of the modification uses one or three or more feature amounts. When three or more feature quantities are used, the circulatory function can be determined based on more detailed numerical values and classification in a multidimensional space.

  -The circulatory function calculating device 1 of embodiment has the display part 100. FIG. However, the configuration of the circulatory function computing device 1 is not limited to this. For example, the circulatory function calculating device 1 according to the modification has a connection terminal for displaying the determination result on an external device instead of or in addition to the display unit 100. In this case, it is easy to prepare various applications in the external device. For this reason, data accumulation and analysis are prepared. For this reason, convenience can be improved.

  -The feature-value calculating part 50 of embodiment calculates the feature-values Z11 and Z21 using all the pulse waves W in the pulse-wave detection period TX. However, the configuration of the feature amount calculation unit 50 is not limited to this. For example, the feature amount calculation unit 50 of the modification calculates the feature amounts Z11 and Z21 using a part of the pulse wave W in the pulse wave detection period TX.

  The feature amount calculation unit 50 of the embodiment calculates a variable value using the relationship between the cuff pressure C and the pulse wave W. However, the configuration of the feature amount calculation unit 50 is not limited to this. For example, the feature amount calculation unit 50 according to the modification calculates a variable value using the relationship between the internal / external pressure difference of the blood vessel and the pulse wave W. The internal / external pressure difference of the blood vessel can be calculated by taking the difference of the compression pressure P from the average blood pressure value.

  -The cuff 11 of each embodiment is wound around the upper arm as a part to be measured of the body of the person to be measured. However, the configuration of the cuff 11 is not limited to this. For example, the cuff 11 of the modified example is wound around a wrist or a lower leg as a measured part of the body of the measured person. In short, any part can be used as the part to be measured as long as it can detect the pulse wave.

  DESCRIPTION OF SYMBOLS 1 ... Cardiovascular function calculating apparatus, 10 ... Compression part, 20 ... Pressure control part, 30 ... Pressure detection part, 40 ... Pulse wave detection part, 50 ... Feature-value calculation part.

Claims (7)

A compression part that compresses the measurement part of the body of the measurement subject;
A pressure detection unit for detecting a compression pressure generated by the compression unit;
A pressure control unit for changing the compression pressure;
A pulse wave detector that detects pulse wave information based on an output signal from the pressure detector in the process of changing the compression pressure by the pressure controller;
A feature that calculates a variable value from the pulse wave information, substitutes the variable value into an arithmetic expression having a plurality of variables and coefficients obtained in advance by multivariate analysis, and calculates a feature value that serves as an index of cardiovascular function and a quantity calculation unit,
The pulse wave information has a plurality of pulse waves in the process of changing the compression pressure,
The said feature-value calculating part is a circulatory function calculating device which calculates the value regarding these pulse waves as said variable value . The circulatory function calculation device according to claim 1 , wherein the feature amount calculation unit calculates the amplitude of each of the plurality of pulse waves as the variable value. The circulatory function calculation device according to claim 1 , wherein the feature amount calculation unit calculates the width of each of the plurality of pulse waves as the variable value. The feature amount is an index for quantitatively determining a blood vessel state as the circulatory function,
The circulatory function calculation device according to any one of claims 1 to 3 , wherein the feature amount calculation unit determines the blood vessel state using the feature amount. The feature amount is an index corresponding to a discriminant value for discriminating a state related to a specific disease related to the cardiovascular function,
The circulatory function according to any one of claims 1 to 3 , wherein the feature amount calculation unit determines a state of the measurement subject related to the specific disease by comparing the feature amount and the determination value. Arithmetic unit. The arithmetic expression is obtained in advance by principal component analysis as multivariate analysis,
The circulatory function calculation device according to any one of claims 1 to 4 , wherein the feature amount calculation unit calculates the feature amount as a value for a main component and determines the circulatory function based on the main component. The feature amount calculation unit calculates an envelope of the plurality of pulse waves with respect to a change in the compression pressure, and calculates the envelope for each predetermined change amount of the compression pressure or a predetermined change amount of the magnitude of the pulse wave. And using the divided value for the envelope as the variable value
Cardiovascular function computation device according to 請 Motomeko 6.