JP6704281B2 - Blood pressure estimation device, blood pressure estimation method, blood pressure estimation program, and recording medium - Google Patents

Description

The present invention relates to a blood pressure estimating device, a blood pressure estimating method, a blood pressure estimating program, and a recording medium for estimating blood pressure using a pulse wave signal and an electrocardiographic signal.

In the related art, a blood pressure estimation method has been studied in which a pulse wave velocity and a pulse wave characteristic amount are calculated using a pulse wave signal and an electrocardiographic signal, and blood pressure is estimated from these.

In Patent Document 1, among electrocardiographic signals and pulse wave signals detected from a living body, biological information obtained from at least the pulse wave signal, a central blood vessel characteristic amount representing the blood vessel elasticity of the central blood vessel, and a blood vessel elasticity of a peripheral blood vessel. There is disclosed a blood pressure estimation device that estimates blood pressure using a peripheral blood vessel feature amount that represents.

Patent Document 2 discloses a blood pressure estimation device that estimates blood pressure using a reference pulse wave calculated from an electrocardiographic signal and a pulse wave signal by a pulse wave analysis device.

JP 2008-302127 A (Published December 18, 2008) JP 2012-071018 A (Published April 12, 2012)

When a blood pressure is estimated using a pulse wave signal and an electrocardiographic signal, noise and a signal are distinguished from each other. Therefore, it is necessary to accurately determine whether or not each signal is valid.

However, the amplitude of the pulse wave signal and the electrocardiographic signal changes for each beat, in addition to the effect of changing the mounting position due to the daily attachment and detachment of the measuring device. Therefore, according to the conventional method such as detecting a signal that exceeds a predetermined threshold value, if the threshold value is too low, noise is erroneously detected as a signal. Also, if the threshold is too high, signals that do not exceed the threshold cannot be detected. Then, if the accuracy of determination as to whether or not the pulse wave signal and the electrocardiographic signal are valid decreases, there is a problem that the accuracy of blood pressure estimation decreases as a result.

The present invention has been made in view of the above problems, and an object thereof is to accurately estimate whether or not each signal is effective in the technique of estimating blood pressure according to a pulse wave signal and an electrocardiographic signal. It is to provide a technique for determining.

In order to solve the above problems, a blood pressure estimation device according to an aspect of the present invention is a blood pressure estimation device that estimates blood pressure in accordance with an electrocardiographic signal and a pulse wave signal, wherein the electrocardiographic signal and the pulse wave are included. For at least one determination target signal selected from the signals, a validity determining unit that determines whether the validity condition is satisfied, and a blood pressure that estimates the blood pressure when the validity determining unit determines that the validity condition is satisfied. An estimation unit is provided, and the validity determination unit updates the validity condition according to the determination target signal.

A blood pressure estimation method according to one aspect of the present invention is a blood pressure estimation method for estimating blood pressure according to an electrocardiographic signal and a pulse wave signal, and at least one selected from the electrocardiographic signal and the pulse wave signal. For one determination target signal, a validity determining step of determining whether the valid condition is satisfied, and a blood pressure estimating step of estimating the blood pressure when it is determined that the valid condition is satisfied in the validity determining step, In the validity determining step, the validity condition is updated according to the determination target signal.

According to one aspect of the present invention, in the technique of estimating blood pressure according to a pulse wave signal and an electrocardiographic signal, it is possible to accurately determine whether or not each signal is valid.

It is a block diagram showing a schematic structure of a blood pressure estimation device concerning one embodiment of the present invention. 6 is a flowchart illustrating a blood pressure estimation method according to an embodiment of the present invention. 6 is a flowchart illustrating a process of determining whether a signal is valid according to an embodiment of the present invention. It is a figure explaining the process of determining whether a signal is effective in one embodiment of the present invention. 6 is a flowchart illustrating a process of determining whether a signal is valid according to an embodiment of the present invention. It is a figure explaining the process of determining whether a signal is effective in one embodiment of the present invention. 6 is a flowchart illustrating a process of determining whether a signal is valid according to an embodiment of the present invention. It is a figure explaining the process of determining whether a signal is effective in one embodiment of the present invention. 6 is a flowchart illustrating a blood pressure estimation method according to an embodiment of the present invention. 6 is a flowchart illustrating a blood pressure estimation method according to an embodiment of the present invention. 6 is a flowchart illustrating a blood pressure estimation method according to an embodiment of the present invention. 6 is a flowchart illustrating a blood pressure estimation method according to an embodiment of the present invention.

[Embodiment 1]
(Blood pressure estimation device 1)
FIG. 1 is a block diagram showing a schematic configuration of a blood pressure estimation device 1 according to one embodiment (Embodiment 1) of the present invention. As shown in FIG. 1, the blood pressure estimation device 1 includes a pair of electrodes 2 and 3, a pulse wave sensor 4, a manual input unit 5, an informing device 6, and a main control unit 10. The blood pressure estimation device 1 is an electronic control device centered on a well-known microcomputer, and is a device that estimates blood pressure based on signals from the electrodes 2, electrodes 3, pulse wave sensor 4, etc., and outputs the result. ..

The pair of electrodes 2 and 3 are electrodes for measuring an electrocardiographic signal of the subject, and function as electrodes of an electrocardiograph that applies a voltage to measure the electrocardiographic signal. The electrodes 2 and 3 are arranged so as to contact the left and right hands of the subject, for example.

The pulse wave sensor 4 is a sensor for measuring a pulse wave signal of a subject, and includes, for example, a well-known light emitting element (for example, LED (Light-Emitting Diode)) and a light receiving element (for example, PD (Photo Diode)). It may be an optical sensor provided. In this case, the pulse wave sensor 4 irradiates the fingertip of the subject with light and measures the pulse wave using the reflected wave.

The manual input unit 5 is a device for a subject to input data (reference information) referred to by the blood pressure estimation device 1 for measuring blood pressure. Examples of the manual input unit 5 include a keyboard, a numeric keypad, a remote controller, and the like. In addition, the manual input unit 5 can also be used as the notification device 6 by using a touch panel.

The reference information input by the subject via the manual input unit 5 includes reference blood pressure (eg, systolic blood pressure and diastolic blood pressure) measured by the subject using a cuff, and physical characteristic information of the subject (eg, weight, height, age). , Gender, etc.) and the like.

The notification device 6 is a device that notifies the subject of the blood pressure estimated by the blood pressure estimation device 1 (for example, the systolic blood pressure and the diastolic blood pressure). For example, a character, a symbol, or an image indicating the blood pressure is displayed, or a voice indicating the blood pressure is displayed. Output. Examples of the notification device 6 include a display such as a liquid crystal display and a speaker.

The main control unit 10 may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like, or may be realized by software using a CPU (Central Processing Unit). In the latter case, the blood pressure estimation device 1 is a ROM (Read Only Memory) in which a CPU that executes instructions of a program that is software that realizes each function, the program and various data are recorded so that they can be read by a computer (or CPU). Alternatively, it is provided with a storage device (these are referred to as “recording medium”), a RAM (Random Access Memory) for expanding the program, and the like.

Further, the main control unit 10 includes an electrocardiographic signal acquisition unit 11, a pulse wave signal acquisition unit 12, a parameter setting unit 13, an electrocardiographic signal analysis unit (validity determination unit, blood pressure estimation unit) 14, a pulse wave signal analysis unit (validity). Judgment unit, blood pressure estimation unit) 15, electrocardiogram and pulse wave signal analysis unit (blood pressure estimation unit) 16, blood pressure calculation unit (blood pressure estimation unit) 17, output processing unit (blood pressure output unit) 18, and error output processing unit It functions as the (error output unit) 19.

The electrocardiographic signal acquisition unit 11 measures the electrical excitement associated with the activity of the subject's heart based on the potential difference between the electrodes 2 and 3 and outputs it as an electrocardiographic signal. The pulse wave signal acquisition unit 12 drives the pulse wave sensor 4 to acquire the pulse wave of the subject, and outputs it as a pulse wave signal. The parameter setting unit 13 receives the input of the reference information via the manual input unit 5, and the blood pressure calculation unit 17 generates and stores the parameter used for the calculation of the estimated blood pressure. The parameter setting unit 13 also stores the reference pulse wave transit time PTT0 output by the electrocardiographic and pulse wave signal analysis unit 16 at the time of preliminary measurement, and generates the parameter from the reference information and the PTT0. Good.

The electrocardiographic signal analysis unit 14 analyzes the electrocardiographic signal input from the electrocardiographic signal acquisition unit 11. The electrocardiographic signal analysis unit 14 calculates, for example, the first-order differential, the second-order differential, etc. of the electrocardiographic signal. Moreover, the electrocardiographic signal analysis unit 14 may calculate, for example, the heart rate, the heartbeat interval, or the like. Further, the electrocardiographic signal analysis unit 14 determines whether or not the electrocardiographic signal is valid.

The pulse wave signal analysis unit 15 analyzes the pulse wave signal input from the pulse wave signal acquisition unit 12. The pulse wave signal analysis unit 15 calculates, for example, the first-order differential, the second-order differential, etc. of the pulse wave signal. Further, the pulse wave signal analysis unit 15, for example, the velocity pulse wave (the wave height of the first peak of the first derivative of the pulse wave signal), the acceleration pulse wave (the wave height of the first peak of the second derivative of the pulse wave signal, etc.). ) Or the like may be calculated. Further, the pulse wave signal analysis unit 15 determines whether the pulse wave signal is valid.

Further, in the above, the photoelectric pulse wave sensor is described as an example of the pulse wave sensor, but the pulse wave sensor may be a pulse wave sensor using a piezoelectric element other than the photoelectric pulse wave sensor. When the pulse wave sensor using the piezoelectric element is used, the velocity pulse wave can be directly measured, so that the acceleration pulse wave can be calculated only by performing the first-order differentiation on the velocity pulse wave signal.

Furthermore, as described above, not only the pulse wave sensor using the photoelectric pulse wave sensor or the piezoelectric element, but the pulse wave sensor may be a pulse wave sensor capable of measuring and calculating velocity pulse wave/acceleration pulse wave. Of course, any sensor that can measure and calculate the pulse wave signal can be used.

In the present embodiment, a mode will be described in which a photoelectric pulse wave sensor is used as a pulse wave sensor, and an output pulse is subjected to first-order differentiation and second-order differentiation to calculate an acceleration pulse wave.

The electrocardiographic and pulse wave signal analysis unit 16 analyzes the electrocardiographic signal input from the electrocardiographic signal acquisition unit 11 and the pulse wave signal input from the pulse wave signal acquisition unit 12 to obtain a pulse corresponding to the electrocardiographic signal. A pulse wave transmission time (PTT), which is a delay time of the wave signal, is calculated. In order to calculate the PTT, the electrocardiographic and pulse wave signal analysis unit 16 further calculates the velocity pulse wave, the acceleration pulse wave, and the like calculated by the pulse wave signal analysis unit 15, and the heartbeat calculated by the electrocardiographic signal analysis unit 14. You may refer to a number, a heartbeat interval, etc.

The blood pressure calculation unit 17 receives the parameters acquired from the parameter setting unit 13, the electrocardiographic signal analysis unit 14, the pulse wave signal analysis unit 15, and the various characteristic amounts (PTT, velocity) acquired from the electrocardiographic and pulse wave signal analysis unit 16. The blood pressure is estimated based on a predetermined arithmetic expression using the pulse wave, the acceleration pulse wave, etc.). The output processing unit 18 outputs a signal indicating the blood pressure estimated by the blood pressure calculation unit 17 to the notification device 6. The error output processing unit 19 notifies the error display device 6 when the electrocardiographic signal analysis unit 14 and the pulse wave signal analysis unit 15 determine that at least one of the electrocardiographic signal and the pulse wave signal is not valid. Let's do it.

In addition, from one viewpoint, the electrocardiographic signal analysis unit 14 and the pulse wave signal analysis unit 15 configure a validity determination unit that determines whether the electrocardiographic signal and the pulse wave signal are valid. Further, in the electrocardiographic signal analysis unit 14, the pulse wave signal analysis unit 15, the electrocardiographic and pulse wave signal analysis unit 16, and the blood pressure calculation unit 17, the validity determining unit determines that the electrocardiographic signal and the pulse wave signal are valid. In this case, a blood pressure estimating unit that estimates blood pressure based on the electrocardiographic signal and the pulse wave signal is configured.

(Operation of blood pressure estimation device 1)
Next, the operation (blood pressure estimation method) of the blood pressure estimation device 1 according to the present embodiment will be described. FIG. 2 is a flowchart illustrating an example of the blood pressure estimation method according to this embodiment.

In the following, the blood pressure estimation device 1 estimates the systolic blood pressure by the arithmetic expression a·PTT+b and the diastolic blood pressure by the arithmetic expression c·PTT+d (a, b, c, d are set in advance. A parameter, and “·” is an operation symbol representing a product.) The configuration will be described, but the present invention is not limited to this, and various feature amounts (PTT, velocity pulse) derived from an electrocardiographic signal and a pulse wave signal. Various known methods (for example, the method described in Patent Document 1) for estimating blood pressure based on a wave, an acceleration pulse wave, etc.) can be used.

In step S1, the parameter setting unit 13 sets (generates and stores) parameters. In one embodiment, the parameter setting unit 13 receives, via the manual input unit 5, the input of the systolic blood pressure and the diastolic blood pressure measured by the subject with the cuff sphygmomanometer. Further, at step S1 or any timing before that, the blood pressure estimation device 1 performs preliminary measurement, acquires the electrocardiographic signal and the pulse wave signal of the subject, and uses the PTT0 calculated by the electrocardiographic and pulse wave signal analysis unit 16. The parameter setting unit 13 stores it. Then, the parameter setting unit 13 sets the above-mentioned parameters a, b, c, and d according to the systolic blood pressure and the diastolic blood pressure measured by the subject with the cuff sphygmomanometer, and the PTT0 stored in the parameter setting unit 13. .. In the present specification, PTT refers to a pulse wave velocity that changes from moment to moment, and PTT0 refers to a PTT measured in advance in the past.

Further, in another embodiment, the parameter setting unit 13 accepts the body feature information of the subject (for example, weight, height, age, sex, etc.) via the manual input unit 5, and based on the body feature information, The parameters may be modified, or the parameters may be set by referring to a table that describes a correspondence relationship between the body feature information and the parameters, which is input in advance. Further, the parameter setting unit 13 may set the parameters as appropriate according to the blood pressure estimation method used by the blood pressure estimation device 1.

For example, in the above, when the manual input unit 5 receives the input of the body feature information but does not receive the input of the systolic blood pressure or the diastolic blood pressure measured by the cuff sphygmomanometer, the parameter setting unit 13 preliminarily sets the user. The systolic blood pressure or the diastolic blood pressure may be estimated by referring to a table in which the correspondence between the body feature information input via the manual input unit 5 and the systolic blood pressure or the diastolic blood pressure is described. By such means, if the manual input unit 5 does not receive the input of the systolic blood pressure or the diastolic blood pressure measured by the cuff blood pressure in advance, and the accuracy of blood pressure measurement is such that the transition of blood pressure fluctuation can be roughly estimated. It can be used in good cases.

In step S2, the electrocardiographic signal acquisition unit 11 acquires an electrocardiographic signal via the electrodes 2 and 3. Further, the pulse wave signal acquisition unit 12 acquires a pulse wave signal via the pulse wave sensor 4.

In step S3, the electrocardiographic signal acquisition unit 11 filters the acquired electrocardiographic signal. An example of the filtering process is a process of extracting a frequency component effective as an electrocardiographic signal. Similarly, the pulse wave signal acquisition unit 12 performs filter processing on the acquired pulse wave signal. An example of the filtering process is a process of extracting a frequency component effective as a pulse wave signal.

In step S4, the electrocardiographic signal analysis unit 14 determines whether the electrocardiographic signal input from the electrocardiographic signal acquisition unit 11 is valid (a valid value as a measurement value). Further, the pulse wave signal analysis unit 15 determines whether the pulse wave signal input from the pulse wave signal acquisition unit 12 is valid (validity determination step). Details of the step of determining whether each signal is valid will be described later.

When it is determined in step S4 that at least one of the electrocardiographic signal and the pulse wave signal is not valid (NO in step S4), in step S5, the error output processing unit 19 causes the notification device 6 to execute the error output. To control. The content of the error output may indicate that a valid electrocardiographic signal cannot be detected, it may indicate that a valid pulse wave signal cannot be detected, or the blood pressure cannot be estimated. May be shown or a combination thereof may be used. The notification device 6 may display the error message on the display or output it from the speaker.

After that, the process may return to step S2, and the electrocardiographic signal and the pulse wave signal may be acquired again. Then, in step S4 executed again, when it is determined that the electrocardiographic signal or the pulse wave signal is valid, the error output processing unit 19 controls the notification device 6 to delete the error output described above. May be. Further, the blood pressure estimation device 1 may output an error and end the process without returning to step S2.

If it is determined in step S4 that at least one of the electrocardiographic signal and the pulse wave signal is not valid (NO in step S4), step S5 may be omitted and the process may return to step S2.

On the other hand, when it is determined in step S4 that both the electrocardiographic signal and the pulse wave signal are valid (YES in step S4), in step S6, the electrocardiographic signal analysis unit 14, the pulse wave signal analysis unit 15, and the heart The electric and pulse wave signal analysis unit 16 calculates a characteristic amount from the electrocardiographic signal and the pulse wave signal which are determined to be valid (blood pressure estimation step 1). In one embodiment, the electrocardiographic and pulse wave signal analysis unit 16 calculates the PTT from the electrocardiographic signal and pulse wave signal that are determined to be valid. Further, in order for the electrocardiographic and pulse wave signal analysis unit 16 to calculate the PTT, the pulse wave signal analysis unit 15 calculates the velocity pulse wave, the acceleration pulse, etc., and provides them to the electrocardiographic and pulse wave signal analysis unit 16. Alternatively, the pulse wave signal analysis unit 15 may calculate a heart rate, a heartbeat interval, and the like, and provide the calculated values to the electrocardiogram and pulse wave signal analysis unit 16.

In this way, by detecting that the pulse wave signal is valid and proceeding to the next step, the influence of the pulse wave signal with an extremely large peak or the pulse wave signal with an extremely small peak is excluded. Therefore, the detection accuracy of the pulse wave signal can be improved. Similarly, by detecting that the electrocardiographic signal is valid and proceeding to the next step, the effect of the electrocardiographic signal with an extremely large peak or the electrocardiographic signal with an extremely small peak is detected. It can be excluded, and the detection accuracy of the electrocardiographic signal can be improved.

In other words, when the validity determining unit (the electrocardiographic signal analyzing unit 14 and the pulse wave signal analyzing unit 15) determines that the pulse wave signal and the electrocardiographic signal are valid, the blood pressure estimating unit (the electrocardiographic signal analyzing unit 14). The pulse wave signal analysis unit 15, the electrocardiographic and pulse wave signal analysis unit 16 and the blood pressure calculation unit 17) are adapted to estimate blood pressure, and thereby, the electrocardiographic signal and pulse wave signal used for estimation of blood pressure. It is possible to improve the accuracy of, and the accuracy of blood pressure estimation. In particular, in the present embodiment, the blood pressure estimation unit estimates the blood pressure according to the electrocardiographic signal and the pulse wave signal determined to be valid by the validity determination unit, so that the blood pressure can be estimated with high accuracy.

Then, in step S7, the blood pressure calculation unit 17 calculates the estimated blood pressure from the PTT calculated by the electrocardiographic and pulse wave signal analysis unit 16 and the parameter set by the parameter setting unit 13 (blood pressure estimation step 2). For example, the blood pressure calculation unit 17 may calculate the systolic blood pressure by the arithmetic expression a·PTT+b. Further, the blood pressure calculation unit 17 may calculate the minimum blood pressure by the calculation formula c·PTT+d. Moreover, as described above, the blood pressure calculation unit 17 may estimate the blood pressure by another known method.

Next, in step S8, the output processing unit 18 controls the notification device 6 to output the systolic blood pressure and the diastolic blood pressure calculated by the blood pressure calculation unit 17. The notification device 6 may display the systolic blood pressure and the diastolic blood pressure on the display or may output them from the speaker. With the above, the blood pressure estimation device 1 completes the blood pressure estimation process.

(Details of validity judgment step)
Next, details of the step of determining whether or not each signal in step S4 is valid (validity determining step) will be described. First, the validity determination step in the present embodiment when the determination target signal is a pulse wave signal will be described. FIG. 3 is a flowchart illustrating the validity determining step in this embodiment, and FIG. 4 is a diagram illustrating the validity determining step in this embodiment.

4A to 4D are graphs showing the electrocardiographic signals acquired by the electrocardiographic signal acquisition unit 11, in which the vertical axis represents the signal value and the horizontal axis represents time.

In the present embodiment, the electrocardiographic signal analysis unit 14 determines that the electrocardiographic signal is valid when the peak value included in the electrocardiographic signal satisfies the valid condition. Then, the electrocardiographic signal analysis unit 14 updates this valid condition with the valid peak detected immediately before the electrocardiographic signal to be determined. Thereby, the valid condition can be set according to the signal to be determined, and it can be accurately determined whether or not the electrocardiographic signal is valid. The details will be described below.

First, the electrocardiographic signal analysis unit 14 detects the peak P _{1 of the} electrocardiographic signal (see (a) of FIG. 4 ). Various known methods can be used as a method for the electrocardiographic signal analysis unit 14 to detect the peak of the electrocardiographic signal. For example, the threshold value 1 and the threshold value 2 that are provided in advance for the value of the electrocardiographic signal are used. By doing so, the peak of the electrocardiographic signal can be detected.

Hereinafter, a case where the electrocardiographic signal analysis unit 14 analyzes at a certain time 1 will be described. The electrocardiographic signal analysis unit 14 determines whether the value of the electrocardiographic signal at time 1 exceeds the threshold 1 (step S44). When the value of the electrocardiographic signal at time 1 is equal to or greater than the threshold value 1, the electrocardiographic signal analysis unit 14 sequentially confirms the value of the electrocardiographic signal after time 1, and determines the value of the electrocardiographic signal that is the maximum value. The peak value of the electrocardiographic signal is used as a candidate, and it is determined whether or not the value of the electrocardiographic signal is less than the threshold value 2 at time 2 before time 1 (step S45). When the electrocardiographic signal becomes less than the threshold value 2 at time 2, the electrocardiographic signal analysis unit 14 determines the peak value candidate of the electrocardiographic signal as an effective peak value of the electrocardiographic signal and detects the effective peak. Then, it is determined that the electrocardiographic signal is valid (step S46). That is, the effective peak is a peak that is equal to or higher than the first threshold and that falls below the second threshold. On the other hand, if the value of the electrocardiographic signal at time 1 is smaller than the threshold value 1 in step S44, and if the value of the electrocardiographic signal at time 2 is not less than the threshold value 2 in step 45, the electrocardiographic signal analysis unit 14 does not detect the effective peak of the electrocardiographic signal, and determines that the electrocardiographic signal is not effective (step S47).

As described above, by setting the threshold values such as the threshold value 1 and the threshold value 2 to the value of the electrocardiographic signal, when the electrocardiographic signal is buried in the noise, the noise signal is erroneously detected as the electrocardiographic signal. It is possible to prevent that.

Alternatively, in another embodiment, the electrocardiographic signal analysis unit 14 may detect the peak of the electrocardiographic signal by performing first-order differentiation and second-order differentiation on the electrocardiographic signal. That is, the electrocardiographic signal analysis unit 14 can detect the extreme value by the first-order differentiation of the electrocardiographic signal, and the extreme value of the electrocardiographic signal calculated by the first-order differentiation is the maximum by the second-order differentiation of the electrocardiographic signal. It is possible to determine whether it is a value or a minimum value. Then, the electrocardiographic signal analysis unit 15 can detect the maximum value as the peak of the electrocardiographic signal.

Then, the electrocardiographic signal analysis unit 14 determines whether or not the detected peaks satisfy the valid conditions defined by the threshold 1 and the threshold 2 (steps S44 to S45). Specifically, the electrocardiographic signal analysis unit 14 determines a peak in which the maximum value of each peak exceeds the threshold value 1 and the fall of each peak is less than the threshold value 2 as an effective peak of the electrocardiographic signal. Then, if the effective peak of the electrocardiographic signal can be detected, the electrocardiographic signal analysis unit 14 determines that the electrocardiographic signal is effective (step S46), and cannot detect the effective peak. In this case, it is determined that the electrocardiographic signal is not valid (step S47).

At this time, the electrocardiographic signal analysis unit 14 updates the effective level of the electrocardiographic signal. Here, updating the effective level means updating the threshold 1 and the threshold 2. The threshold 1 and the threshold 2 updated by the electrocardiographic signal analysis unit 14 may be determined by the detected peak values (P0 to P2 in FIG. 4). For example, when the electrocardiographic signal analysis unit 14 detects that the peak P1 of the electrocardiographic signal is higher than the latest (previously detected) peak P0 (FIG. 4B), the electrocardiographic signal analysis unit 14 sets the signal detection level to The threshold may be updated to increase. When the peak of the electrocardiographic signal rises, the level of the whole electrocardiographic signal also rises. Therefore, after the electrocardiographic signal exceeds the threshold 1, it does not become lower than the threshold 2, and the electrocardiographic signal that is not noise is effective. This is because it cannot be determined that

Further, as shown in FIG. 4C, the electrocardiographic signal analysis unit 14 detects the peak P2 of the electrocardiographic signal, and when the peak P2 of the electrocardiographic signal is lower than the most recent peak P1, the signal The threshold values 1 and 2 may be updated so as to reduce the detection level (see FIG. 4(d)). When the peak of the electrocardiographic signal decreases, the level of the electrocardiographic signal as a whole also decreases, so that the electrocardiographic signal does not exceed the threshold value 1 and it is impossible to determine that the electrocardiographic signal that is not noise is valid. Is.

In addition, the electrocardiographic signal analysis unit 14 significantly reduces the level of the electrocardiographic signal due to poor contact with the sensor, etc., and the electrocardiographic signal does not exceed the threshold value 1, and the peak candidate of the electrocardiographic signal cannot be detected. If it is determined that the thresholds 1 and 2 have been set, the thresholds 1 and 2 may be updated to prescribed values (or initial values). Here, as an example of the method of determining that the candidate of the electrocardiographic signal peak cannot be detected by the electrocardiographic signal analysis unit 14, the time from when the candidate of the electrocardiographic signal peak cannot be detected is measured, and There is a method of making the above determination when the time has passed.

As described above, the thresholds 1 and 2 are set to detect the peaks, and when the peaks cannot be detected with the thresholds 1 and 2, the thresholds 1 and 2 are updated to the prescribed values, which is unnecessary. It is possible to detect signals with high sensitivity, while removing such signals as much as possible.

Up to this point, the explanation has been made mainly on the electrocardiographic signal, but the above-described method can be similarly applied to the pulse wave signal. That is, the pulse wave signal analysis unit 15 determines whether or not the pulse wave signal is valid by performing the same steps as S44 to S47 on the pulse wave signal acquired by the pulse wave signal acquisition unit 12. , And the effective level of the pulse wave signal can be updated. Thereby, the detection accuracy of the pulse wave signal can be improved.

As described above, the blood pressure estimation device 1 according to the present embodiment, when the determination target signal includes a peak equal to or higher than the first threshold value and includes an effective peak falling below the second threshold value, The judgment target signal is judged to be valid. Then, when the effective peak is detected from the determination target signal, the blood pressure estimation device 1 according to the present embodiment changes the first threshold value and the second threshold value according to the value of the detected effective peak. This makes it possible to accurately determine whether each signal is valid. Particularly, when the value of the detected effective peak is higher than the value of the effective peak detected immediately before, the blood pressure estimation device 1 according to the present embodiment raises the first threshold value and the second threshold value to detect the detected effective value. When the value of the peak is lower than the value of the effective peak detected immediately before, the first threshold value and the second threshold value may be lowered. Thereby, the first threshold value and the second threshold value can be adjusted appropriately.

[Embodiment 2]
The second embodiment of the present invention will be described below. The second embodiment is the same as the first embodiment except that the validity determination step executed by the blood pressure estimation device 1 is different. Hereinafter, description of members having the same functions as those described in the first embodiment will be omitted.

First, the validity determination step in the present embodiment when the determination target signal is an electrocardiographic signal will be described. FIG. 5 is a flowchart illustrating the validity determining step in this embodiment, and FIG. 6 is a diagram illustrating the validity determining step in this embodiment.

6A and 6B are graphs each showing an example of an electrocardiographic signal acquired by the electrocardiographic signal acquisition unit 11, in which the vertical axis represents the signal value and the horizontal axis represents time.

In the present embodiment, the electrocardiographic signal analysis unit 14 determines that the electrocardiographic signal is valid when the peak time included in the electrocardiographic signal is within a predetermined time range from the first time. To do. Then, the electrocardiographic signal analysis unit 14 updates the first time to the time of the peak detected immediately before. As a result, it is possible to determine that the determination target signal having a peak with an interval from the immediately preceding peak in a predetermined time range is valid. The details will be described below.

First, the electrocardiographic signal analysis unit 14 buffers (temporarily stores) the time (time 1) of the peak value P1 detected last time (step S41). As the method for the electrocardiographic signal analysis unit 14 to detect the peak of the electrocardiographic signal, various known methods as described in the first embodiment can be used. Then, when the electrocardiographic signal analysis unit 14 newly detects the peak value P2 at the time 2 (step S42), the electrocardiographic signal analysis unit 14 determines the time interval between the time 1 of the peak P1 and the time 2 of the peak P2. , Is within a predetermined time range (effective range) (step S43). Then, the electrocardiographic signal analysis unit 14 validates the electrocardiographic signal when the time interval between the time 1 of the peak P1 and the time 2 of the peak P2 is within a predetermined time range (effective range). If the time interval between the time 1 of the peak P1 and the time 2 of the peak P2 is not within the predetermined time range (effective range), the electrocardiographic signal is not effective. It is determined that there is not (step S47).

In this way, the electrocardiographic signal analysis unit 14 determines whether the electrocardiographic signal is valid according to whether the detected peak of the electrocardiographic signal includes a peak within a predetermined time range from the first time. When determining whether or not to determine whether or not the first target time is updated to the time of the peak detected immediately before, the determination target signal having the peak in the time range in which the interval with the previous peak is within a predetermined time range is valid. Can be determined as As a result, a normal electrocardiographic signal as shown in (a) of FIG. 6 is determined to be valid, and a rapidly changing electrocardiographic signal as shown in (b) of FIG. 6 is determined to be invalid. You can

The time range (effective range) in step S43 can be determined by various methods. For example, the electrocardiographic signal analysis unit 14 may actually measure the interval between peaks of the electrocardiographic signal in advance and set the time range (effective range) so that each measured interval is included. Alternatively, by the above method, the electrocardiographic signal analysis unit 14 similarly calculates time ranges (effective ranges) for a plurality of subjects, and the time range (actual range) in which the average value of these time ranges (effective ranges) is actually used ( It may be set as an effective range). The set time range (effective range) may be stored in the parameter setting unit 13 in advance, for example.

Up to this point, the explanation has been made mainly on the electrocardiographic signal, but the above-described method can be similarly applied to the pulse wave signal. That is, the pulse wave signal analysis unit 15 performs the same steps as S41 to S43 and S46 to S47 on the pulse wave signal acquired by the pulse wave signal acquisition unit 12 to determine whether or not the pulse wave signal is valid. It becomes possible to determine and the effective level of the pulse wave signal can be updated. Thereby, the detection accuracy of the pulse wave signal can be improved.

[Embodiment 3]
The third embodiment of the present invention will be described below. In the third embodiment, the electrocardiographic and pulse wave signal analysis unit 16 is used instead of the electrocardiographic signal analysis unit 14 and the pulse wave signal analysis unit 15, and the validity determination step executed by the blood pressure estimation device 1 is different. Other than that is the same as the first embodiment. Hereinafter, description of members having the same functions as those described in the first embodiment will be omitted.

The validity determination step in this embodiment will be described. FIG. 7 is a flowchart illustrating the validity determining step in this embodiment, and FIG. 8 is a diagram illustrating the validity determining step in this embodiment. FIG. 8 is a graph showing an electrocardiographic signal acquired by the electrocardiographic signal acquisition unit 11, in which the vertical axis represents the signal value and the horizontal axis represents time. Note that FIG. 8A shows an example of the electrocardiographic signal acquired by the electrocardiographic signal acquisition unit 11. 8B is a diagram showing the pulse wave transit time calculated by the electrocardiographic and pulse wave signal analyzing unit 16, and the scale of time is the same as the electrocardiographic signal of FIG. 8A described above. , (A) and (b) of FIG. 8 correspond to each other. 8A, the electrocardiographic signal is normally measured in the section (i), and referring to FIG. 8B, the pulse wave transit time is the section (i). In, it can be seen that the value is calculated within a certain range. In the following, an example in which an electrocardiographic signal is used as a target for determining whether or not the electrocardiographic and pulse wave signal analysis unit 16 is valid is described, but the same applies when the pulse wave signal is a determination target. Can be used.

In the section (ii) in FIG. 8A, the signal level of the electrocardiographic signal greatly fluctuates, and in the section (ii) in FIG. 8B, the pulse wave transit time significantly fluctuates. There is. The cause of the large fluctuation of the signal level of the electrocardiographic signal in the section (ii) may be that the contact between the subject and the sensor is changed.

In the section (iii) in FIG. 8A, the pulse wave transit time is calculated within a certain range, although the signal level of the electrocardiographic signal is lowered. The cause of the decrease in the signal level of the electrocardiographic signal is considered to be poor contact between the subject and the sensor.

In the present embodiment, the electrocardiographic and pulse wave signal analysis unit 16 determines that the pulse wave propagation time is valid when the pulse wave propagation time satisfies the valid condition of being within the valid level range. Then, the electrocardiographic and pulse wave signal analysis unit 16 calculates the valid condition according to the plurality of pulse wave transit times immediately before the determination target pulse wave transit time. Thereby, the valid condition can be set according to the signal to be determined, and it can be accurately determined whether or not the pulse wave propagation time is valid. The details will be described below.

First, the electrocardiographic and pulse wave signal analysis unit 16 calculates the pulse wave transit time (see the vertical axis in (b) of FIG. 8) (step S51).

Next, the electrocardiographic and pulse wave signal analysis unit 16 uses the plurality of pulse wave transit times immediately before the pulse wave transit time of the determination target to calculate the median pulse wave transit time a ((b) in FIG. 8). Is calculated) (step S52). Then, the electrocardiographic and pulse wave signal analysis unit 16 calculates the effective range according to the median value a (step S53). Specifically, the electrocardiographic and pulse wave signal analysis unit 16 calculates a range of a predetermined width -α to +α centered on the median value a as an effective range (see (b) of FIG. 8 ).

Note that α in step S53 can be determined by various methods. For example, the electrocardiographic and pulse wave signal analysis unit 16 actually measures the pulse wave transit time in advance, calculates the median value of the pulse wave transit time, and calculates the median value and other effective pulse wave transit times. The maximum value of the difference may be set as α. Alternatively, by the above method, the electrocardiographic and pulse wave signal analysis unit 16 may similarly calculate α for a plurality of subjects and set the average value of these α as the actually used α. The set α may be stored in the parameter setting unit 13 in advance, for example.

Then, the electrocardiographic and pulse wave signal analysis unit 16 determines whether or not the calculated pulse wave propagation time is within the effective range (step S54). When the calculated pulse wave transit time is within the valid range (YES in step S54), the electrocardiographic and pulse wave signal analysis unit 16 determines that the pulse wave transit time to be determined is valid (step S55). ). On the other hand, when the calculated pulse wave transit time is not within the valid range (NO in step S54), the electrocardiogram and pulse wave signal analysis unit 16 determines that the pulse wave transit time to be determined is not valid ( Step S56). Explaining the pulse wave transit time shown in FIG. 8B as an example, since the pulse wave transit times are all within the effective range −α to +α in the section (i), the electrocardiogram and the pulse wave. The signal analysis unit 16 determines that the electrocardiographic signal in the section is valid. In the section (ii), all the pulse wave transit times are not within the effective range −α to +α, so the electrocardiogram and pulse wave signal analysis unit 16 determines that the electrocardiographic signal in the section is not valid. judge. In the section (iii), the pulse wave transit times are all within the valid range -α to +α, so the electrocardiographic and pulse wave signal analysis unit 16 validates the electrocardiographic signal in the section. To determine.

As described above, the electrocardiographic and pulse wave signal analysis unit 16 is effective according to the median value of the pulse wave transit times, not the average value of the pulse wave transit times immediately before the determination target pulse wave transit time. The range is updated, and it is determined whether the electrocardiographic signal and the pulse wave signal are valid based on the valid range. As a result, it is possible to exclude the influence of the extremely large pulse wave transit time and the influence of the extremely small pulse wave transit time. Thereby, the calculation accuracy of the pulse wave transit time can be improved.

[Embodiment 4]
The following describes Embodiment 4 of the present invention. The fourth embodiment is the same as the first to third embodiments except for the validity determining step executed by the blood pressure estimation device 1. Hereinafter, description of members having the same functions as those described in Embodiments 1 to 3 will be omitted.

In the validity determining step in this embodiment, two or more selected from the validity determining step in the first embodiment, the validity determining step in the second embodiment, and the validity determining step in the third embodiment are executed. Then, when it is determined to be valid in all the validity determining steps, the determination target signal is determined to be valid. This makes it possible to more accurately determine whether or not the determination target signal is valid.

[Embodiment 5]
The fifth embodiment of the present invention will be described below. Hereinafter, description of members having the same functions as those described in Embodiments 1 to 4 will be omitted.

FIG. 9 is a flowchart illustrating an example of the blood pressure estimation method according to this embodiment. As shown in FIG. 9, in the blood pressure estimation method according to the present embodiment, steps S1 to S8 similar to those in the first embodiment are executed. The present embodiment is different from the first embodiment in that steps S11 to S14 are executed between step S1 and step S2.

That is, in the present embodiment, after step S1, in step S11, the blood pressure estimation device 1 acquires only one of the electrocardiographic signal and the pulse wave signal. Then, regarding one of the acquired signals (determination target signal), as in steps S3 to S5, the filtering process (step S12), the validity determination (step S13), and the case where it is determined that the signal is not valid in step S13 The error output process (step S14) is executed.

Then, if it is determined in step S13 that the one of the signals is valid (YES in step S13), the process proceeds to step S2, and the subsequent steps are performed in the same manner as in the first embodiment.

As described above, the blood pressure estimation device 1 newly acquires the pulse wave signal and the electrocardiographic signal in step S2 after the judgment target signal is determined to be valid in step S13, and the acquired pulse wave signal and electrocardiographic signal are acquired. Estimate blood pressure based on the issue. With this, the blood pressure is estimated according to the acquired signal after the effective signal is obtained, so that the blood pressure can be estimated with high accuracy.

[Sixth Embodiment]
The sixth embodiment of the present invention will be described below. Hereinafter, description of members having the same functions as those described in Embodiments 1 to 5 will be omitted.

FIG. 10 is a flowchart illustrating an example of the blood pressure estimation method according to this embodiment. As shown in FIG. 10, in the blood pressure estimation method according to the present embodiment, steps S1 to S3, S6 to S8, and S11 to S14 similar to those in the fifth embodiment are executed. The present embodiment is different from the fifth embodiment in that steps S4 to S5 are not executed.

That is, in the present embodiment, when one of the signals is determined to be valid in step S13 (YES in step S13), the process proceeds to step S2, and thereafter, it is not determined whether or not the signal is valid. Even with such a configuration, the blood pressure can be estimated with high accuracy because the blood pressure is estimated according to the signal acquired after the valid signal is obtained.

[Embodiment 7]
The seventh embodiment of the present invention will be described below. Hereinafter, description of members having the same functions as the members described in Embodiments 1 to 6 will be omitted.

FIG. 11 is a flowchart illustrating an example of the blood pressure estimation method according to this embodiment. As shown in FIG. 11, in the blood pressure estimation method according to the present embodiment, steps S1 to S8 and S11 to S14 similar to those in the fifth embodiment are executed. The present embodiment is different from the fifth embodiment in that Step S1 is executed between Step S13 and Step S2.

That is, in the present embodiment, step S1 is performed after it is determined in step S13 that one signal is valid (YES in step S13). As a result, it is possible to avoid useless input by accepting an input after a valid signal is obtained.

[Embodiment 8]
The eighth embodiment of the present invention will be described below. Hereinafter, description of members having the same functions as the members described in Embodiments 1 to 7 will be omitted.

FIG. 12 is a flowchart illustrating an example of the blood pressure estimation method according to this embodiment. As shown in FIG. 12, in the blood pressure estimation method according to the present embodiment, steps S1 to S3, S6 to S8, and S11 to S14 similar to those in the sixth embodiment are executed. The present embodiment is different from the sixth embodiment in that step S1 is executed between step S13 and step S2.

That is, in the present embodiment, step S1 is performed after it is determined in step S13 that one signal is valid (YES in step S13). As a result, it is possible to avoid useless input by accepting an input after a valid signal is obtained.

[Embodiment 9]
The first to eighth embodiments of the present invention have been described above in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and a design etc. within the scope not departing from the gist of the present invention are also possible. Within the scope of the claims.

Further, the program that operates on the device is a program that controls the CPU and the like (a program that causes a computer to function) so as to realize the functions of the above-described embodiments. Then, the information handled by these devices is temporarily stored in a temporary storage device (for example, RAM) at the time of the processing, and then stored in various ROM or HDD storage devices, and is read and corrected by the CPU as necessary. -Writing is performed.

Here, as a recording medium for storing the program, a semiconductor medium (for example, a ROM or a non-volatile memory card), an optical recording medium/a magneto-optical recording medium (for example, a DVD (Digital Versatile Disc), an MO (Magneto Optical) Disc), MD (Mini Disc), CD (Compact Disc), BD, etc.), magnetic recording medium (for example, magnetic tape, flexible disk, etc.), and the like. Further, by executing the loaded program, not only the functions of the above-described embodiment are realized, but also by processing in cooperation with the operating system or other application programs based on the instructions of the program, The function of the invention may be realized in some cases.

In the case of distribution in the market, the program can be stored in a portable recording medium for distribution or transferred to a server computer connected via a network such as the Internet. In this case, it goes without saying that the storage device of the server computer is also included in the present invention.

Further, a part or all of each device in the above-described embodiments may be typically realized as an LSI (Large Scale Integration) which is an integrated circuit. Each functional block of each device may be individually made into a chip, or a part or all of them may be integrated into a chip. Further, the method of circuit integration is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. Further, in the case where a technique for forming an integrated circuit which replaces the LSI appears due to the progress of the semiconductor technique, it goes without saying that an integrated circuit according to the technique can be used.

[Summary]
A blood pressure estimation device (1) according to aspect 1 of the present invention is a blood pressure estimation device that estimates blood pressure according to an electrocardiographic signal and a pulse wave signal, and is at least selected from the electrocardiographic signal and the pulse wave signal. A validity determining section (electrocardiographic signal analyzing section 14, pulse wave signal analyzing section 15, electrocardiogram and pulse wave signal analyzing section 16) for determining whether or not the valid condition is satisfied for one determination target signal; When it is determined that the section satisfies the valid condition, the blood pressure estimating section that estimates the blood pressure (electrocardiographic signal analyzing section 14, pulse wave signal analyzing section 15, electrocardiogram and pulse wave signal analyzing section 16, blood pressure calculating section 17). ) And the validity determination unit updates the validity condition according to the determination target signal.

According to the above configuration, when determining whether the determination target signal is valid, the validity condition is updated according to the determination target signal. Accordingly, it is possible to set a valid condition according to the determination target signal, and it is possible to accurately determine whether each signal is valid.

In the blood pressure estimation device according to the second aspect of the present invention, in the first aspect, the valid condition is that the determination target signal is a peak equal to or higher than a first threshold and falls below a second threshold. Including the condition that includes, the valid determination unit, from the determination target signal, when the valid peak is detected, the value of the detected valid peak is higher than the value of the valid peak detected immediately before, If the value of the effective peak detected by increasing the first threshold and the second threshold is lower than the value of the effective peak detected immediately before, the first threshold and the second threshold are set to It may be lowered.

According to the above configuration, whether or not the determination target signal is effective depending on whether or not each determination target signal has a peak equal to or higher than the first threshold and includes an effective peak falling below the second threshold. When determining whether or not the effective peak is detected, the first threshold value and the second threshold value are increased according to the comparison result between the detected effective peak value and the immediately preceding detected effective peak value. By lowering and lowering, the first threshold value and the second threshold value can be adjusted appropriately.

In the blood pressure estimation device according to the third aspect of the present invention, in the first aspect or the second aspect, the valid condition includes a condition that the determination target signal includes a peak within a predetermined time range from the first time. The validity determining unit may update the first time to the time of the peak detected immediately before.

According to the above configuration, it is possible to determine that a determination target signal having a peak with an interval from the immediately preceding peak in a predetermined time range is valid.

In the blood pressure estimation device according to the fourth aspect of the present invention, in the first to third aspects, the valid condition includes a condition that the pulse wave propagation time calculated from the determination target signal exists within a valid range, and The validity determining section may calculate a median value of the pulse wave transit time calculated from the determination target signal and calculate the validity range according to the median value.

According to the above configuration, the pulse wave propagation time calculated from the determination target signal, when determining whether the determination target signal is valid depending on whether it is in the valid range, the determination target signal The median value of the pulse wave transit time calculated from is calculated, and the effective range is calculated according to the median value. In this way, when calculating the effective range, by using the median value of the pulse wave transit times instead of the average value of the pulse wave transit times, the extremely large pulse wave transit time or the extremely small pulse wave transit time is used. The effect of time can be excluded. This makes it possible to accurately determine whether each signal is valid.

In the blood pressure estimation device according to the fifth aspect of the present invention, in the fourth aspect, the validity determining section may calculate a range of a predetermined width centered on the median value as the valid range. ..

According to the above configuration, the effective range can be calculated appropriately.

In the blood pressure estimation device according to the sixth aspect of the present invention, in the first to fifth aspects, when the validity determination unit determines that at least one of the determination target signals does not satisfy the validity condition, an error output is executed. The error output unit (error output processing unit 19) may be further provided.

According to the above configuration, the subject can be notified that the blood pressure cannot be estimated based on the valid signal.

In the blood pressure estimation device according to the seventh aspect of the present invention, in the first to sixth aspects, the validity determination section uses both the electrocardiographic signal and the pulse wave signal as the determination target signals, and the blood pressure estimation section The validity determining unit may estimate the blood pressure according to the electrocardiographic signal and the pulse wave signal determined to satisfy the validity condition.

According to the above configuration, the blood pressure is estimated according to the signal determined to be valid, so that the blood pressure can be estimated with high accuracy.

In the blood pressure estimation device according to the eighth aspect of the present invention, in the first to sixth aspects, the validity determination unit uses one of the electrocardiographic signal and the pulse wave signal as the determination target signal, and the blood pressure estimation unit is The validity determining unit may estimate the blood pressure according to the electrocardiographic signal and the pulse wave signal acquired after determining that the determination target signal satisfies the validity condition.

According to the above configuration, since the blood pressure is estimated according to the signal acquired after the valid signal is obtained, the blood pressure can be estimated with high accuracy.

In the blood pressure estimation device according to the ninth aspect of the present invention, in the eighth aspect, after the validity determination section determines that all the determination target signals satisfy the validity conditions, the reference information is received and the reference information is received. The blood pressure estimating unit may further include a parameter setting unit (13) that sets a parameter based on information, and the blood pressure estimating unit may estimate the blood pressure by referring to the parameter.

According to the above configuration, the blood pressure can be appropriately estimated by referring to the parameter generated based on the input reference information. At this time, useless input can be avoided by accepting input after a valid signal is obtained.

A blood pressure estimation apparatus according to Aspect 10 of the present invention is the blood pressure estimation unit according to any one of Aspects 1 to 8, further including a parameter setting unit (13) that receives an input of reference information and sets a parameter based on the reference information. May estimate the blood pressure with reference to the parameters.

According to the above configuration, the blood pressure can be appropriately estimated by referring to the parameter generated based on the input reference information.

In the blood pressure estimation device according to the eleventh aspect of the present invention, in the tenth aspect, the reference information includes information indicating a reference blood pressure measured using a cuff and a pulse wave transit time measured in the past. Good.

According to the above configuration, it is possible to appropriately estimate the blood pressure using the input reference blood pressure measured using the cuff and the pulse wave transit time measured in the past.

In the blood pressure estimation device according to aspect 12 of the present invention, in the above aspects 1 to 11, the blood pressure estimation unit calculates a pulse wave transit time from the electrocardiographic signal and the pulse wave signal, and the calculated pulse wave transit time. The blood pressure may be estimated according to the above.

According to the above configuration, the blood pressure can be appropriately estimated using the calculated pulse wave transit time.

In the blood pressure estimation device according to the thirteenth aspect of the present invention, in the first to twelfth aspects, the blood pressure estimation unit may estimate the systolic blood pressure and the diastolic blood pressure as the blood pressure.

According to the above configuration, it is possible to provide the subject with the calculation results of the systolic blood pressure and the diastolic blood pressure.

The blood pressure estimation device according to the fourteenth aspect of the present invention may further include a blood pressure output unit (output processing unit 18) that outputs the blood pressure estimated by the blood pressure estimation unit in the first to thirteenth aspects.

According to the above configuration, the blood pressure estimation result can be suitably provided to the subject.

A blood pressure estimation method according to aspect 15 of the present invention is a blood pressure estimation method for estimating blood pressure according to an electrocardiographic signal and a pulse wave signal, and at least one determination selected from the electrocardiographic signal and the pulse wave signal. For the target signal, a validity determining step of determining whether or not the validity condition is satisfied, and a blood pressure estimating step of estimating the blood pressure when it is determined that the validity condition is satisfied in the validity determining step, are provided. In the determination step, the valid condition is updated according to the determination target signal.

According to the above configuration, the same effect as that of the first aspect is achieved.

The blood pressure estimation device according to each aspect of the present invention may be realized by a computer. In this case, the blood pressure estimation device is implemented by operating the computer as each unit (software element) included in the blood pressure estimation device. The blood pressure estimation program of the blood pressure estimation device realized by the above, and the computer-readable recording medium recording the program are also included in the scope of the present invention.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each of the embodiments.

DESCRIPTION OF SYMBOLS 1 Blood pressure estimation device 2, 3 electrode 4 Pulse wave sensor 5 Manual input part 6 Notification device 10 Main control part 11 Electrocardiographic signal acquisition part 12 Pulse wave signal acquisition part 13 Parameter setting part 14 Electrocardiographic signal analysis part (effectiveness determination part, Blood pressure estimation unit)
15 Pulse wave signal analysis unit (validity determination unit, blood pressure estimation unit)
16 Electrocardiogram and pulse wave signal analysis unit (blood pressure estimation unit)
17 Blood pressure calculation unit (blood pressure estimation unit)
18 Output processing unit (blood pressure output unit)
19 Error output processing unit (error output unit)

Claims (17)

A blood pressure estimation device for estimating blood pressure according to an electrocardiographic signal and a pulse wave signal,
At least one determination target signal selected from the electrocardiographic signal and the pulse wave signal, the validity determination unit for determining whether to satisfy the validity condition,
A blood pressure estimating unit that estimates the blood pressure when the validity determining unit determines that the validity condition is satisfied,
The validity determination unit updates the validity condition according to the determination target signal ,
The valid condition includes a condition that the determination target signal includes a valid peak which is a peak equal to or higher than a first threshold and falls below a second threshold,
If the value of the detected effective peak is higher than the value of the effective peak detected immediately before when the effective peak is detected from the determination target signal, the effective determination unit determines the first threshold value and The second threshold value is increased, and when the value of the detected effective peak is lower than the value of the effective peak detected immediately before, the first threshold value and the second threshold value are decreased. Blood pressure estimation device. The valid condition includes a condition that the determination target signal includes a peak within a predetermined time range from the first time,
The blood pressure estimation device according to claim 1, wherein the validity determination unit updates the first time to a time of a peak detected immediately before. The valid condition includes a condition that the pulse wave propagation time calculated from the determination target signal exists within the valid range,
The validity determination unit calculates a median value of the pulse wave propagation time calculated from the determination target signal, in accordance with the median value, any claim 1 or 2, characterized in that calculating the effective range The blood pressure estimation device according to claim 1. The blood pressure estimation device according to claim 3 , wherein the validity determination unit calculates a range of a predetermined width centered on the median value as the validity range. The validity determination unit, when it is determined that the at least one of the determination target signal does not satisfy the validity condition, according to claim 1-4, characterized by further comprising an error output unit for performing an error output The blood pressure estimation device according to claim 1. The validity determination unit, both the electrocardiographic signal and the pulse wave signal, the determination target signal,
The blood pressure estimation unit, any the validity determination unit according to claim 1-5, characterized in that for estimating the blood pressure in response to a determination by the above electrocardiographic signal and the pulse wave signal satisfies the validity condition The blood pressure estimation device according to claim 1. The validity determining unit, one of the electrocardiographic signal and the pulse wave signal is the determination target signal,
The blood pressure estimation unit estimates the blood pressure according to the electrocardiographic signal and the pulse wave signal acquired after the validity determination unit determines that the determination target signal satisfies the validity condition, blood pressure estimation apparatus according to any one of claim 1 to 5. A blood pressure estimation device for estimating blood pressure according to an electrocardiographic signal and a pulse wave signal,
At least one determination target signal selected from the electrocardiographic signal and the pulse wave signal, the validity determination unit for determining whether to satisfy the validity condition,
A blood pressure estimating unit that estimates the blood pressure when the validity determining unit determines that the validity condition is satisfied,
The validity determination unit updates the validity condition according to the determination target signal,
The validity determining unit, one of the electrocardiographic signal and the pulse wave signal is the determination target signal,
The blood pressure estimating unit estimates the blood pressure according to the electrocardiographic signal and the pulse wave signal acquired after determining that the validity determining unit satisfies the validity condition for the determination target signal,
After determining that the validity determination unit satisfies the validity conditions for all of the determination target signals, the input of reference information is accepted, and a parameter setting unit that sets parameters based on the reference information is further provided.
The blood pressure estimating device estimates the blood pressure with reference to the parameters. Further comprising a parameter setting unit that accepts input of reference information and sets parameters based on the reference information,
The blood pressure estimation unit, by referring to the parameter, the blood pressure estimation apparatus according to any one of claim 1 to 7, characterized in that for estimating the blood pressure. The blood pressure estimation device according to claim 9 , wherein the reference information includes a reference blood pressure measured using a cuff and information indicating a pulse wave transit time measured in the past. The blood pressure estimation unit calculates a pulse wave propagation time from the electrocardiographic signal and the pulse wave signal, calculated in accordance with the pulse wave propagation time of claims 1-10, characterized in that for estimating the blood pressure The blood pressure estimation device according to any one of claims. The blood pressure estimation unit, as the blood pressure, the blood pressure estimation apparatus according to any one of claim 1 to 11, characterized in that for estimating the systolic blood pressure and diastolic blood pressure. Blood pressure estimation apparatus according to any one of claim 1 to 12, characterized by further comprising a blood pressure output unit for outputting the blood pressure the blood pressure estimating portion is estimated. A blood pressure estimation method for estimating blood pressure according to an electrocardiographic signal and a pulse wave signal,
At least one determination target signal selected from the electrocardiographic signal and the pulse wave signal, a valid determination step of determining whether to satisfy the valid condition,
In the validity determining step, if it is determined that the validity condition is satisfied, a blood pressure estimating step of estimating the blood pressure is provided,
In the validity determining step, the validity condition is updated according to the determination target signal,
The valid condition includes a condition that the determination target signal includes a valid peak which is a peak equal to or higher than a first threshold and falls below a second threshold,
In the validity determination step, when the valid peak is detected from the determination target signal, the detected valid peak value is higher than the immediately preceding detected valid peak value, and the first threshold value and When the value of the effective peak detected by increasing the second threshold is lower than the value of the effective peak detected immediately before, the first threshold and the second threshold are decreased. Blood pressure estimation method. A blood pressure estimation method for estimating blood pressure according to an electrocardiographic signal and a pulse wave signal,
At least one determination target signal selected from the electrocardiographic signal and the pulse wave signal, a valid determination step of determining whether to satisfy the valid condition,
In the validity determining step, if it is determined that the validity condition is satisfied, a blood pressure estimating step of estimating the blood pressure is provided,
In the validity determining step, the validity condition is updated according to the determination target signal,
In the validity determination step, one of the electrocardiographic signal and the pulse wave signal is the determination target signal,
In the blood pressure estimation step, the blood pressure is estimated according to the electrocardiographic signal and the pulse wave signal acquired after it is determined that the valid condition is satisfied for the determination target signal in the validity determination step,
After determining that the valid condition is satisfied for all of the determination target signals in the validity determination step, the input of reference information is accepted, and the method further includes a parameter setting step of setting a parameter based on the reference information,
In the blood pressure estimation step, the blood pressure is estimated with reference to the parameters, the blood pressure estimation method. A blood pressure estimation program for causing a computer to function as the blood pressure estimation apparatus according to any one of claim 1 to 13 blood pressure estimation program for causing a computer to function as each section provided in the blood pressure estimation apparatus. A computer-readable recording medium in which the blood pressure estimation program according to claim 16 is recorded.

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