JP6562658B2 - Pulse wave signal measuring apparatus and control method thereof - Google Patents

Description

  The present invention relates to a pulse wave signal measuring apparatus and a control method thereof.

  Conventionally, as an index of vascular diseases such as arteriosclerosis, the ratio of blood pressure measured in the lower limbs and upper limbs (lower limb upper limb blood pressure ratio), pulse wave velocity or pulse wave velocity (PWV) is generally used. ing. As the lower limb upper limb blood pressure ratio, for example, the ratio of systolic blood pressure measured with the upper arm and ankle (ABI) and the ratio of systolic blood pressure measured with the upper arm and toes (TBI) are known. Used as an indicator of presence or absence. On the other hand, PWV is the speed at which the wave generated when the blood vessel wall pressure derived from blood flow from the heart to the aorta travels through the artery is transmitted through the blood vessel wall, and the higher the speed, the harder the blood vessel. To do. PWV is obtained by measuring the pulse wave at two points on the blood vessel and its propagation time (PWT) and dividing the distance between the two points by the propagation time.

However, since the pulse wave propagation speed is a value that varies depending on the blood pressure, correction according to the blood pressure value is actually required. Therefore, the present applicant has proposed an evaluation value β expressed by the following formula as a vascular sclerosis index that does not depend on blood pressure (Patent Document 1).
β = (2ρ / ΔP) · ln (P _s / P _d ) · PWV ²
(Where ρ is blood density (constant), P _s is systolic blood pressure, P _d is diastolic blood pressure, ΔP = P _s −P _d , ln () is a natural logarithm)

Japanese Patent No. 4627418 JP 2014-61178 A

  In order to reduce the influence of errors for each pulse and to obtain an accurate PWT (and PWV), it is desirable to average the PWT calculated for a plurality of consecutive pulses. Therefore, it is important to measure a stable pulse wave for a plurality of consecutive heartbeats, but the pulse wave also varies depending on the body movement and tension of the subject.

  Patent Document 2 discloses a configuration in which the quality of a pulse wave is determined and displayed based on a variation in time difference between pulse wave division points. With this display, when the quality of the pulse wave is low, the user (examiner) can repeatedly measure the pulse wave until the pulse wave quality becomes high.

  However, even if the display is overlooked or the meaning of the display is not understood, if the user does not perform remeasurement, the accuracy of the PWT will remain low, which is not the fundamental solution. .

  The present invention has been made in view of the above-described problems of the prior art, and an object thereof is to provide a pulse wave inspection apparatus and a control method thereof that support easy measurement of a high-quality PWT.

The above-described object is to provide a measuring means for measuring a predetermined pulse wave propagation time with respect to a pulse wave signal for a predetermined time detected in at least one part, and a pulse wave propagation time measured by the measuring means. When the determination unit determines that the quality is determined and the quality determined by the determination unit is equal to or higher than a predetermined reference, the measurement of the pulse wave propagation time by the measurement unit and the determination by the determination unit are terminated. possess a control unit, a pulse wave signal a predetermined reference, characterized in that the total number of pulse wave propagation time measuring means has measured a percentage of what is included in the scope of a predetermined degree of variation Achieved by the measuring device.

  With such a configuration, according to the present invention, it is possible to provide a pulse wave inspection apparatus and a control method thereof that support easy measurement of a high-quality PWT.

It is a block diagram which shows the function structural example of a blood pressure pulse wave test | inspection apparatus as an example of the pulse wave signal measuring device which concerns on embodiment of this invention. It is a flowchart for demonstrating the detail of the cuff mistake mounting | wearing determination process of the blood pressure pulse wave inspection apparatus which concerns on embodiment. It is a schematic diagram for demonstrating the principle of the cuff mistake mounting | wearing determination process of the blood pressure pulse wave inspection apparatus which concerns on embodiment. It is a flowchart for demonstrating the detail of the pulse wave measurement process of the blood pressure pulse wave test | inspection apparatus which concerns on embodiment. It is a figure which shows the example of the display screen in the blood pressure pulse wave inspection apparatus which concerns on embodiment.

Hereinafter, the present invention will be described in detail based on exemplary embodiments with reference to the drawings.
● (Device configuration)
FIG. 1 is a block diagram illustrating a configuration example of a blood pressure pulse wave inspection apparatus as an example of a pulse wave signal measurement apparatus according to an embodiment of the present invention. The blood pressure pulse wave inspection apparatus includes a main body 200 and a cuff or a sensor connected to the main body 200.

  The arithmetic control unit 10 controls the operation of the entire blood pressure pulse wave inspection apparatus of the present embodiment. The arithmetic control unit 10 has, for example, one or more programmable processors (CPU, MPU, etc.), ROM, and RAM (including nonvolatile RAM) not shown. The arithmetic control unit 10 executes the control program stored in the ROM or the storage unit 80, thereby realizing the functions of the blood pressure pulse wave test apparatus including the cuff erroneous attachment detection process described later. The storage unit 80 may be a nonvolatile storage device such as a hard disk drive, a writable optical disk drive, or a nonvolatile semiconductor memory.

  The display unit 70 is a display device such as an LCD, and displays various operation guidance, a GUI (Graphical User Interface) screen, a measured biological signal, a measurement result report, and the like. The display unit 70 may be built in the main body 200 or an external display device connected to the main body 200.

  The recording unit 75 is typically a thermal printer, and prints out a measured biological signal, a measurement result report, and the like. The voice generation unit 85 includes a speaker and outputs various voice messages and notification sounds. The input / instruction unit 90 is an input device such as a keyboard, a mouse, a button, or a touch panel, and is used by a user to input instructions and settings to the blood pressure pulse measuring device. Similarly to the display unit 70, the input / instruction unit 90 may be built in the main body 200 or may be externally attached.

  The upper limb blood-feeding control unit 201 includes a rubber sac 21aR in the cuff 21R for mounting on the upper right limb (upper right arm) and a rubber sac 21aL in the cuff 21L for mounting on the left upper limb (left upper arm), respectively. It has a connector for connecting a pair of connected hoses 21h. Further, the upper limb blood pressure control unit 201 includes pressure sensors 211R and 211L that detect the internal pressure of each of the pair of hoses 21h.

  The lower limb blood stagnation control unit 202 is applied to the rubber sac 22aR in the cuff 22R for mounting on the right lower limb (right ankle) and the rubber sac 22aL in the cuff 22L for mounting on the left lower limb (left ankle), respectively. It has a connector for connecting a pair of connected hoses 22h. Further, the lower limb blood pressure control unit 202 includes pressure sensors 221R and 221L that detect internal pressures of the pair of hoses 22h.

Here, the configuration in which two cuffs are connected to the upper limb blood pressure control unit 201 and the lower limb blood pressure control unit 202 is shown, but a configuration in which one cuff is connected to each other may be used.
The upper limb blood drive control unit 201 and the lower limb blood drive control unit 202 basically have the same configuration, but the arithmetic control unit 10 outputs an upper limb measurement signal from the upper limb blood drive control unit 201, and the lower limb blood drive control unit 202. It is assumed that the measurement signal of the lower limb is output from the blood pressure control unit 202.

  Each of the upper limb blood pressure control unit 201 and the lower limb blood pressure control unit 202 includes a pump and an exhaust valve whose operations can be controlled by the arithmetic control unit 10. The arithmetic control unit 10 controls the pressurization / decompression (supply / exhaust) of the cuff rubber sac (21aR, 21aL, 22aR, 22aL) by controlling the operations of the pump and the exhaust valve. The pressure sensors 211R, L and 221R, L output an electrical signal corresponding to the internal pressure of the rubber couch 21aR, 21aL, 22aR, 22aL of the connected cuff. The upper limb blood pressure control unit 201 and the lower limb blood pressure control unit 202 apply signal processing such as amplification and A / D conversion to the electrical signals output from the pressure sensors 211R, L and 221R, L, and obtain pulse wave information. Output to the arithmetic control unit 10. Thereby, the calculation control part 10 can acquire the pulse wave required for calculation of PWV, the blood pressure required for calculation of ABI, and the like.

  A heart sound microphone 23 is connected to the heart sound detection unit 203, performs predetermined signal processing such as amplification and A / D conversion on the heart sound signal detected by the heart sound microphone 23 attached to the subject, and the arithmetic control unit 10. To supply. As will be described later, the heart sound signal is mainly used to determine the start time of the pulse wave in the heart.

  The electrocardiogram signal detection unit 204 is an electrocardiograph, applies predetermined signal processing to the electrocardiogram signals obtained from the plurality of connected electrocardiogram electrodes 24a and 24b, and supplies the signal to the arithmetic control unit 10. In the figure, for the sake of simplicity, two electrocardiographic electrodes 24a and 24b are shown, but in actuality, the number and types of electrodes corresponding to the type and number of electrocardiographic signals to be acquired are used. The electrocardiogram signal is acquired as necessary when performing a more comprehensive diagnosis.

  The pulse wave detection unit 205 is a pulse wave signal detected by pulse wave sensors 25a and 25b which are, for example, amorphous pulse wave sensors or airbag type pulse wave sensors, specifically carotid, hip and popliteal arteries. A predetermined signal processing is applied to the wave signal and supplied to the arithmetic control unit 10. The number of pulse wave sensors may be three or more depending on the number of pulse wave signals to be measured.

  In addition, the main body 200 of the blood pressure pulse wave examination apparatus may be provided with a wired and / or wireless communication interface for communicating with other devices, a storage device using a removable medium, and the like in addition to the illustrated one. . Further, in the case where the display unit 70 and the recording unit 75 can be made a separate device from the main body 200, a known display interface and printer interface are provided.

  Of the components included in the main body 200 of the blood pressure pulse wave examination apparatus, one or more of the heart sound detection unit 203, the electrocardiogram signal detection unit 204, and the pulse wave detection unit 205 are not realized as individual circuits. The function may be realized by a programmable processor included in the arithmetic control unit 10 executing software.

● (Preparation before measurement)
A procedure and operation when performing measurement using the blood pressure pulse wave inspection apparatus having such a configuration will be described. Here, a case where measurement with the highest accuracy is performed will be described. The initial setting process relating to the device operation such as time setting, the process of attaching the sensor or cuff to the main body 200, the personal information of the subject such as ID, age, sex, height, and weight is input / instruction unit 90. It is assumed that the input process has already been performed. Moreover, although the case where it measures using all four cuffs is demonstrated below, the measurement using one upper limb and one lower limb is also possible.

  The blood pressure pulse wave inspection apparatus of the present embodiment can perform pulse wave measurement and blood pressure measurement. For example, when calculating the above-described evaluation value β (hereinafter referred to as CAVI value), the PWV is calculated. It performs in order of pulse wave measurement and blood pressure measurement. When only PWT or PWV measurement is performed, only pulse wave measurement is performed. When only ABI or TBI measurement is performed, only blood pressure measurement is performed. However, the pulse wave measurement related to the present invention will be described in detail below.

  First, as a preparation stage, a cuff, a sensor, and the like are attached to a predetermined part of the subject. Specifically, the cuff 21R for the upper limb is placed on the upper right arm of the subject, the cuff 21L is placed on the left upper arm of the subject, and the cuff 22R for the lower limb is placed on the right ankle or toe of the subject. 22L is attached to the left ankle or toe of the subject. The cuff attached to the ankle and the cuff attached to the toe are different in configuration, but here both are described as the lower limb cuff. The cuffs 21 and 22 can be attached with a hook-and-loop fastener or the like. Further, the electrocardiographic electrodes 24a and 24b are attached to the left and right wrists, for example. A cream or the like is applied to the mounting site as is usually done for good detection. The attachment site of the electrocardiographic electrodes 24a and 24b can be changed according to the type of guidance to be acquired. In addition, when the electrocardiogram signal is not measured, it is not necessary to attach the electrocardiogram electrodes 24a and 24b.

  Further, the heart sound microphone 23 is attached to a predetermined chest position of the subject (the left edge of the second intercostal sternum) with a tape or the like. Further, the pulse wave sensor 25a is attached to the neck (carotid artery pulsation site). Further, if necessary, the pulse wave sensor 25b is attached to the buttocks (hip artery pulsation site) or the right or left popliteal center. When the pulse wave signal is measured only with the cuff, it is not necessary to mount the pulse wave sensors 25a and 25b.

In the case of measuring PWV, next, the distance D from the left edge of the subject's II intercostal sternum (part where the heartbeat microphone 23 is attached) to the right hip artery pulsation part (part where the pulse wave sensor 25b is attached) ,
-Distance L2 from the right hip artery pulsation site to the center of the right knee joint,
-Distance L3 from the center of the right knee joint to the center of the right ankle cuff attachment site,
Are measured and input using a scale. These distances are used as blood vessel lengths. For these distances, statistical values corresponding to the height of the subject may be automatically used without actually measuring. This completes the preparation before measurement.

● (Pulse wave measurement processing)
When preparation for measurement is completed, for example, when a measurement start instruction is given from the input / instruction unit 90, the arithmetic control unit 10 first measures pulse wave measurements on the upper limb blood pressure control unit 201 and the lower limb blood pressure control unit 202. Instruct the start of. In response to this, the upper limb tourniquet control unit 201 detects the internal pressure of the rubber sac 21aR, 21aL of the cuff 21R, 21L (hereinafter referred to as cuff pressure) detected by the pressure sensors 211R, 211L as a predetermined pressure (for example 50 It supplies with a pump until it becomes about ~ 60mmHg). Similarly, the leg driving control unit 202 supplies air to the rubber sac 22aR and 22aL.

  In addition, the upper limb blood pressure control unit 201 and the lower limb blood pressure control unit 202 start the air supply control, and signals (pulse wave signals) representing changes in cuff pressure detected by the pressure sensors 211R, 211L, 221R, and 221L. ) To the arithmetic control unit 10 is started.

  When the arithmetic control unit 10 starts to receive pulse wave signals from the upper limb blood pressure control unit 201 and the lower limb blood pressure control unit 202, the arithmetic control unit 10 executes the cuff erroneous attachment determination process while saving the pulse wave signal in the storage unit 80. To do. The erroneous cuff wearing determination process is a process of determining whether or not the cuff wearing site is correct (in this embodiment, whether the upper limb and the lower limb are mistakenly worn).

(Incorrect cuff attachment determination process)
Details of the cuff erroneous attachment determination process will be described with reference to the flowchart of FIG. In S101, the arithmetic control unit 10 determines whether or not a predetermined feature point (segmentation point) is detected for the pulse wave signals received from the upper limb blood pressure control unit 201 and the lower limb blood pressure control unit 202. To do. Here, the rising point of the pulse wave signal is detected as the feature point, but may be another feature point such as a notch point. Then, if there is a pulse wave signal for which a feature point cannot be detected, the arithmetic control unit 10 displays a message on the display unit 70, for example, and confirms the wearing state of the cuff corresponding to the pulse wave signal. (S103), and the process returns to S101.

  If it is determined that the feature points can be detected from all of the pulse wave signals, in S105, the arithmetic control unit 10 uses the same heartbeat for the pair of pulse wave signals received as the pulse wave signals measured in the right half of the body. Corresponding feature points are detected. Here, the rising point of the pulse wave signal is detected, but it may be another feature point such as a notch point. Then, the arithmetic control unit 10 uses the same heartbeat of the pulse wave signal received as measured by the upper limb (upper right arm) and the pulse wave signal received as measured by the lower limb (right ankle). It is determined whether or not the context of the generation timing of the same feature point according to the above matches the context assumed when the cuff attachment site is correct.

  As shown in FIG. 3, if there is no mistake in the cuff wearing part between the upper limb and the lower limb, the pulse wave signal related to the same heartbeat has a distance from the heart higher than the rising point 301 measured by the upper right arm. The rising point 302 measured at the far right ankle should occur later. In other words, Tba (pulse wave propagation time between the upper arm and the ankle) in the figure should be a positive value. In this way, when the correct wearing site has a different positional relationship with respect to the distance from the heart, the front-rear relationship of the detection timing of the characteristic points of the pulse group related to the same heartbeat can be assumed in advance. Therefore, the arithmetic control unit 10 is assumed to have a context in which the relationship between the generation timings of the feature points of the pair of pulse wave signals received as measured by the same body is correct when the cuff attachment site is correct. It is determined whether or not. Note that the determination in S105 is that the pulse wave signal received as measured by the upper limb (upper right arm) rather than the rising point of the pulse wave signal received as measured by the lower limb (right ankle). It may be determined whether the rising point is early. The arithmetic control unit 10 performs the same determination on a pair of pulse wave signals received as pulse wave signals measured on the left half.

  In S105, if the anteroposterior relation of the generation timing of the feature point of the received pulse wave signal matches the assumed anteroposterior relation, the arithmetic control unit 10 advances the process to S107, and the upper limb and lower limb wearing parts It is determined that there is no mistake. And it transfers to the PWT measurement process mentioned later.

  On the other hand, when the context of the generation timing of the feature point of the received pulse wave signal does not match the expected context (the difference), the arithmetic control unit 10 advances the process to S109, and It is determined that a misplacement of the lower limb attachment site has occurred. Then, in S111, instructing the upper limb blood pressure control unit 201 and the lower limb blood pressure control unit 202 to stop the waveform measurement, and displaying a message on the display unit 70, for example, wearing that seems to be erroneously worn. Along with the information on the part, the user is prompted to confirm the part to which the cuff is attached. Then, it waits until a measurement start instruction is given again from the input / instruction unit 90.

(PWT measurement process)
Next, PWT measurement processing performed prior to calculation of PWV will be described with reference to the flowchart of FIG. In the above-described erroneous cuff wearing determination process, when it is determined that the cuff is worn without any mistake between the upper limb and the lower limb, the arithmetic control unit 10 starts calculating the PWT. In the present embodiment, variations in the values of a plurality of PWTs calculated for pulse wave signals for a plurality of beats detected in a predetermined time period (for example, 5 seconds, 8 seconds, or 16 seconds) are predetermined. The PWT calculation process is continued until the condition is satisfied.

  First, the arithmetic control unit 10 instructs the heart sound detection unit 203, the electrocardiogram signal detection unit 204, and the pulse wave detection unit 205 to start measurement of a heart sound signal, an electrocardiogram signal, and a pulse wave signal. As described above, the electrocardiogram signal and the pulse wave signal of the carotid artery and the hip artery are measured as necessary. In response to this instruction, the heart sound detection unit 203, the electrocardiogram signal detection unit 204, and the pulse wave detection unit 205 are signals measured through the heart sound microphone 23, the electrocardiogram electrodes 24a and 24b, and the pulse wave sensors 25a and 25b. The output to the arithmetic control unit 10 is started.

  Note that a measurement start instruction for a heart sound signal (and an electrocardiogram signal or a pulse wave signal, if necessary) can be performed at any time after or simultaneously with the measurement start instruction for a pulse wave signal.

  The arithmetic control unit 10 stores the heart sound signal, the electrocardiogram signal, and the pulse wave signal output from the heart sound detection unit 203, the electrocardiogram signal detection unit 204, and the pulse wave detection unit 205 in the storage unit 80 as shown in FIG. The PWT calculation process shown is started.

  In S201, the arithmetic control unit 10 starts calculating PWT (Tb and Tba). Specifically, the arithmetic control unit 10 first detects the generation timing of the heart II sound in the heart sound signal acquired via the heart sound detection unit 203. When the electrocardiogram signal is measured, the arithmetic control unit 10 determines that the peak group of heart sound signals (peak group derived from the heart I sound) existing in the vicinity of the R wave generation timing of the electrocardiogram signal is in a lull state. The first rising point of the peak group that appears is detected as the heart II sound generation timing. When the electrocardiogram signal is not measured, the arithmetic control unit 10 detects the first rising point of the peak group first appearing in the heart sound signal after the rising point of any pulse wave signal as the generation timing of the heart II sound. To do.

Then, the arithmetic control unit 10 calculates the following values of Tb and Tba and Tb + Tba as PWT and stores them in the storage unit 80.
Tb: time difference from the generation timing of heart II sound to notch point of brachial pulse wave (or carotid artery wave) Tba: ankle (or toe) pulse from rising point of brachial pulse wave (or carotid artery wave) Time difference to the rise of the wave

  In S203, the arithmetic control unit 10 determines whether the PWT has been calculated for the pulse wave signals for the set time. If not, the process returns to S201, and if the calculation is completed, the process proceeds to S205.

In S205, the arithmetic control unit 10 evaluates the quality of the PWT calculated for the pulse wave signal for the set time based on, for example, the degree of variation in the PWT value. It is assumed that n beats of pulse wave signals are measured at the set time and n PWTs are calculated in S201. In this case, the arithmetic control unit 10 can determine the quality of the PWT based on the ratio of the total number of PWTs included in the range of the predetermined variation degree as the evaluation value of the variation degree.
The evaluation value is, for example, evaluation value (%) = (number of calculated values included in the range of average value ± σ) / total number of calculated values n × 100
It may be. Here, σ is a standard deviation of n PWTs. The evaluation value may be obtained for at least one of Tb, Tba, and Tb + Tba. When obtaining one evaluation value, it is preferable to obtain Tb + Tba.

And the arithmetic control part 10 determines the quality of PWT calculated about the pulse-wave signal for the set time according to an evaluation value as follows, for example.
◎: 75% or more ○: 50% or more and less than 75% Δ: 25% or more and less than 50% ×: less than 25%

The arithmetic control unit 10 can notify the user of the result determined here through the display unit 70, for example.
FIG. 5 shows an example of a display screen on the display unit 70 of the blood pressure pulse wave examination apparatus according to the present embodiment. The arithmetic control unit 10 starts display of this screen from, for example, a measurement preparation stage. When the electrocardiogram signal 331, the heart sound signal 332, and the pulse wave signal 333 are received, the calculation control unit 10 immediately approaches the waveform display unit 330 in the screen in real time. The waveform for a predetermined time is displayed.

  The upper part of the waveform display unit 330 corresponds to the quality display region 310 corresponding to the PWT calculated based on the pulse wave measured on the right half and the PWT calculated based on the pulse wave measured on the left half. The quality display area 320 is provided. The arithmetic control unit 10 can notify the user of the quality of the PWT by performing the display according to the above-described evaluation value in the quality display areas 310 and 320. In addition to displaying on the waveform display screen, the quality display may be performed on another display device or display device such as an LED provided on the housing of the blood pressure pulse wave inspection apparatus.

  In this embodiment, the quality of the PWT (which can be said to be the quality of the measured pulse wave signal) is divided into four stages, so that the quality display is also performed in four stages. Although there is no particular limitation on the specific display method, in the present embodiment, the quality display areas 310 and 320 are divided into four partial areas 311 to 314 and 321 to 324, respectively, and display according to the above-described four stages of divisions. I do. The number of quality evaluation sections and the number of partial areas do not have to have a one-to-one correspondence.

  Specifically, from the leftmost of the four partial areas 311 to 314 and 321 to 324, according to the above-described evaluation classification, one in x, two from left in △, three in ◯, and four in ◎ (All) display (lights up). In addition to the number of partial areas to be displayed, the display color may be changed according to the number. In this embodiment, since x and △ are determined to have a problem in quality, display effects (color, brightness, presence / absence of blinking, etc.) are shown for cases corresponding to x and △ and cases corresponding to ○ and ◎. It may be different. When the evaluation value is calculated for a plurality of PWTs (two or more of Tb, Tba, and Tb + Tba in the present embodiment), one of the evaluation results (Tb + Tab in the present embodiment) is displayed in the quality display areas 310 and 320. Show it.

  By displaying the quality of the PWT calculated for the pulse wave signal for the set time in real time, the user can grasp the accuracy of the calculated PWT. And if the accuracy is low, stop the measurement, check whether the cuff is properly worn, wait for the subject to be in a resting state, and then measure again, so the accuracy is good The calculation result of PWT can be obtained.

  However, even if only PWT with low accuracy is obtained, conventionally, when the calculation of PWT for a pulse wave signal for a set time has been completed, the PWT measurement processing has been completed. Therefore, when the user overlooks the quality display areas 310 and 320 or does not understand the meaning of the display, there is a problem that the accuracy of the PWT remains low. The former can be prevented if the user monitors the quality display areas 310 and 320, but it is a burden on the user. In addition, as a result of looking at the quality display areas 310 and 320, measurement is performed until the best quality (◎) is obtained in spite of the acceptable quality (（) being obtained in order to obtain a more accurate PWT. It may be retried many times, which increases the burden on both the user and the subject.

  Therefore, in this embodiment, when the quality evaluation result is less than the threshold value (when it falls under the above-mentioned x or Δ category), even if the set time has elapsed, the PWT calculation result having the quality equal to or higher than the threshold value Is obtained, the blood pressure pulse wave inspection device automatically extends the PWT measurement process.

  Specifically, in S207, the arithmetic control unit 10 proceeds to S209 if the evaluation result in S205 is equal to or greater than a predetermined standard (the degree of variation is less than the predetermined standard), and the evaluation result is less than the predetermined standard (the degree of variation is equal to or greater than the predetermined standard). ), The process proceeds to S211. Here, if the above-described evaluation value (%) is 50% or more, that is, an evaluation value classified into ◯ or ◎, the evaluation result is equal to or greater than a predetermined standard (the degree of variation is less than the predetermined standard). When the evaluation values are calculated for a plurality of PWTs (two or more of Tb, Tba, and Tb + Tba in the present embodiment), all of them or one or more predetermined evaluation results are less than a predetermined standard (the degree of variation is predetermined). If it is greater than or equal to the reference, the process proceeds to S211. In the present embodiment, if the evaluation result of Tb + Tba is less than a predetermined reference (the degree of variation is equal to or greater than the predetermined reference), the process proceeds to S211 regardless of the evaluation results of other PWTs.

  In S209, the arithmetic control unit 10 performs a pulse wave measurement process end process. As a result, the measurement is automatically terminated when the quality of the PWT calculated from the pulse wave signal for the latest set time satisfies a predetermined standard. In addition, both of the arithmetic control units 10 are included in the range of the average value ± standard deviation σ of the calculated values of n PWTs (Tb, Tba and Tb + Tba) calculated from the pulse wave signals for the set time. An average value of the PWT is calculated as a representative value of the PWT in the pulse wave signal for the set time. Then, when calculating the CAVI value and / or the ABI value, the process proceeds to the blood pressure measurement process. When the blood pressure measurement is not performed, the pulse wave velocity (PWV) is calculated as necessary in S210 and the process is terminated. To do. PWV can be calculated, for example, as PWV = (D × 1.3 + L2 + L3) / (Tb + Tba) using the representative value of Tb and Tba calculated in S209 or the representative value of Tb + Tba. The calculation of PWV may be performed by blood pressure measurement processing.

  By the end processing of the pulse wave measurement process, the upper limb blood pressure control unit 201 and the lower limb blood pressure control unit 202 exhaust the rubber sac 21aR, 21aL, 22aR, and 22aL of the cuffs 21R, 21L, 22R, and 22L. Further, the operations of the heart sound detection unit 203, the electrocardiogram signal detection unit 204, and the pulse wave detection unit 205 may be stopped.

  When measuring the CAVI value or the ABI value, the arithmetic control unit 10 instructs the upper limb blood pressure control unit 201 and the lower limb blood pressure control unit 202 to start blood pressure measurement, and performs blood pressure measurement by the oscillometric method. . When only the CAVI value is measured, only the blood pressure of the upper right arm may be measured. When measuring the ABI value, blood pressure is measured with one pair or two pairs of the upper limb and the lower limb, similar to the measurement of PWT. Since details of the blood pressure measurement and calculation of the CAVI value and the ABI value can be performed by a known method, the description of further details is omitted.

  On the other hand, in S211, the arithmetic control unit 10 determines whether or not a predetermined upper limit time of pulse wave measurement (for example, 120 seconds) has been reached, and if the upper limit time has been reached, the upper limit time has been reached in S217. If not, the process proceeds to S213.

  In S217, the arithmetic control unit 10 performs the same pulse wave measurement process termination process as in S209, and displays a message on the display unit 70, for example, to inform the user that the pulse wave measurement has not been performed normally. To do. At this time, it is desirable to report together the parts (the right half and / or the left half) whose quality did not reach the standard.

  If the duration of the pulse wave measurement has not reached the upper limit time, the arithmetic control unit 10 continues the pulse wave measurement and the calculation of the PWT in S213. At this time, the arithmetic control unit 10 may notify that the PWT measurement process is automatically extended by displaying a message on the display unit 70 or the like. In S215, the arithmetic control unit 10 performs quality evaluation in the same manner as in S205 on one or more types of n PWTs (Tb, Tba, Tb + Tba) calculated from pulse wave signals for the most recently set time, The process returns to S207.

  In this way, the arithmetic control unit 10 starts the measurement of the pulse wave and then determines a predetermined 1 of n PWTs (Tb, Tba, Tb + Tba) calculated from the pulse wave signals for the latest set time. The PWT calculation and its quality evaluation are automatically extended (continued) until the degree of variation satisfies a predetermined standard for more than one type. Then, each time a new PWT is calculated, it is determined whether the variation degree of the n PWTs calculated from the pulse wave signals for the most recently set time satisfies a predetermined criterion, and if the predetermined criterion is satisfied, the pulse is automatically generated. The wave measurement process is terminated.

  Therefore, the user can measure a PWT having a quality that satisfies the necessary standard, except by giving a measurement start instruction, except when the cuff is not properly worn. In addition, when the cuff is worn with the upper limb and the lower limb mixed up, the device automatically detects and notifies the user before the PWT measurement, so that it is possible to cope with it early and the PWT measurement operation. Can be avoided. In addition, if the pulse wave signal measurement device of the present embodiment is applied to a device such as a blood pressure pulse wave inspection device that performs pulse wave measurement and blood pressure measurement with the same configuration (here, cuff), the cuff is measured prior to blood pressure measurement. It is possible to confirm that the wearer is worn without making a mistake between the upper limb and the lower limb, which is useful.

(Other embodiments)
When only the PWV measurement is performed, the PWT may be obtained as a time difference between the R wave timing of the electrocardiogram signal and one pulse wave notch point (notch). In this case, the pulse wave measurement with the cuff may be performed at one place.

  In addition, regarding the cuff mis-attachment determination process, if the pulse wave is measured at two locations where the detection timing of the same kind of feature points of the same pulse related to the same heartbeat is significantly different, the measurement site is the upper arm portion. It is not limited to one part of the upper limb and one part of the lower limb such as an ankle or toe. The pulse signal detection means is not limited to a cuff, and may be any sensor capable of detecting a pulse.

  In the above-described embodiment, for ease of explanation and understanding, PWTs calculated for all n heartbeats included in a pulse wave signal for a preset measurement time are collectively evaluated, and representative values are set. The case where it asks was explained. However, the number of PWTs to be evaluated or to obtain a representative value may be smaller than the total heart rate included in the pulse wave signal for a preset measurement time. In this case, if the evaluation results performed a plurality of times for the pulse wave signal for the preset measurement time are all equal to or higher than the reference, the measurement is terminated.

  In addition, even when the evaluation values are obtained for all the heartbeats included in the pulse wave signal for the preset measurement time, the quality of the PWT for the preset measurement time is evaluated using a plurality of evaluation values. May be. For example, if the preset measurement time is 8 seconds, the PWT quality evaluation obtained from the pulse wave signal measured in the last 8 seconds is performed every second, and the evaluation above the standard is performed 8 times in succession. You may comprise so that measurement may be complete | finished by making the measurement result into the last 8 seconds when the result was obtained. In this case, since the quality evaluation is performed every second, eight evaluations are performed for the measurement time of 8 seconds, and the quality evaluation can be performed with higher accuracy. The evaluation may be performed every beat instead of every second.

  In addition, the control method of the pulse wave signal measuring apparatus according to the present invention can also be realized as a program (application software) that causes a programmable processor (computer) included in the arithmetic control unit 10 to execute the above-described operation. Therefore, such a program and a storage medium storing the program (an optical recording medium such as a CD-ROM or DVD-ROM, a magnetic recording medium such as a magnetic disk, a semiconductor memory card, etc.) also constitute the present invention. .

21L, 21R, 22L, 22R ... cuff, 23 ... heart sound microphone, 24a, 24b ... electrocardiographic electrodes, 25a, 25b ... pulse wave sensor, 70 ... display unit, 201 ... Upper extremity blood drive control unit, 202 ... lower limb blood drive control unit, 203 ... heart sound detection unit, 204 ... electrocardiogram signal detection unit, 205 ... pulse wave detection unit, 211L, 211R, 221L 221R ... Pressure sensor

Claims (11)

Measuring means for measuring a predetermined pulse wave propagation time for a pulse wave signal for a predetermined time detected in at least one part;
Determining means for determining the quality of the pulse wave propagation time measured by the measuring means;
Control means for ending the measurement of the pulse wave propagation time by the measurement means and the determination by the determination means when the quality determined by the determination means is equal to or higher than a predetermined reference and the determination means;
I have a,
The pulse wave signal measuring apparatus according to claim 1, wherein the predetermined reference is a ratio of a total number of pulse wave propagation times measured by the measuring means that is included in a range of a predetermined degree of variation .   When the quality determined by the determination unit is less than a predetermined reference, the control unit determines the quality of the pulse wave propagation time measured by the measurement unit for the pulse wave signal for the most recent predetermined time. 2. The pulse according to claim 1, wherein measurement of the pulse wave propagation time by the measurement unit and determination by the determination unit are executed until the determination unit determines that is equal to or greater than the predetermined reference. Wave signal measuring device.   The pulse wave signal measuring apparatus according to claim 2, further comprising a notifying means for notifying a user that the measurement is extended when the quality determined by the determining means is less than a predetermined reference. .   Even if the predetermined upper limit time is reached, if the quality of the pulse wave propagation time measured by the measuring means is not determined by the determining means to be equal to or higher than the predetermined reference, the control means can detect the pulse wave by the measuring means. The pulse wave signal measuring apparatus according to any one of claims 1 to 3, wherein the measurement of the propagation time and the determination by the determination unit are stopped.   5. The pulse wave propagation time is measured by the measurement means using an electrocardiogram signal or a heart sound signal and a pulse wave signal detected at one site of an upper limb or a lower limb. The pulse wave signal measuring device according to any one of the above.   The measurement means measures two types of pulse wave propagation times using a heart sound signal and pulse wave signals detected at one part of the upper limb and one part of the lower limb. 5. The pulse wave signal measuring device according to any one of 1 to 4.   The at least one part is two parts, one is an upper arm part or a neck part, and the other is a thigh, a knee, an ankle, or a toe, according to claim 5 or 6 characterized by things. Pulse wave signal measuring device. The range of the predetermined variation degree, pulse wave signal according to any one of claims 1 to 7, wherein the measuring means is characterized by a range of mean ± standard deviation of the pulse wave propagation time measured Measuring device. 9. The apparatus according to claim 1, further comprising a calculation unit that calculates a pulse wave propagation speed based on a pulse wave propagation time measured by the measurement unit and included in the range of the predetermined degree of variation . The pulse wave signal measuring device according to any one of the above. A measurement step of measuring a predetermined pulse wave propagation time for a predetermined amount of pulse wave signals detected at at least one site;
A determination step of determining the quality of the pulse wave propagation time measured in the measurement step;
When the quality determined by the determination step is determined by the determination step to be equal to or higher than a predetermined reference, the control step ends the execution of the measurement step and the determination step;
I have a,
The method for controlling a pulse wave signal measuring apparatus, wherein the predetermined reference is a ratio of a total number of pulse wave propagation times measured in the measuring step and included in a range of a predetermined degree of variation . The program for functioning a computer as each means of the pulse-wave signal measuring device of any one of Claim 1 to 9 .