JP2008168073A - Apparatus and method for processing biological information - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve reliability and efficiency of an arteriosclerosis inspection. <P>SOLUTION: A blood pressure and pulse wave measurement section 200 comprises a measurement control section 201 for the upper limb and a measurement control section 202 for the lower limb. The measurement control sections for the upper and lower limbs measure pulse waves of the right and left upper arms and the right and left ankles using cuffs 21R, 21L, 22R and 22L respectively. An operation control section 10 detects characteristic points for every pulse wave period of each acquired pulse wave. A display section 70 displays a waveform of the acquired pulse wave on a real-time basis while specifying detected characteristic points of the pulse wave. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a biological information processing apparatus and a biological information processing method.

  With the rapid aging of society, prevention of arteriosclerotic diseases has become an important theme in the medical field. Of the three major causes of death in Japan, arteriosclerosis is the main cause of heart disease and cerebrovascular disease excluding cancer. Therefore, it is important to detect arteriosclerosis early and treat it appropriately. In recent years, a blood flow disorder of the lower limb arteries called obstructive arteriosclerosis (ASO) is increasing mainly in elderly people. Obstructive arteriosclerosis is one that develops as a result of the progression of arteriosclerosis.

  The arteriosclerosis test includes, for example, a test for blood flow disorder in the lower limb blood vessels and a test for arterial extensibility. The blood pressure pulse wave inspection apparatus used for these examinations can measure biological information such as blood pressure and pulse wave, and derive an index (hereinafter referred to as “arteriosclerosis degree”) that can be used for the examination of arteriosclerosis. Hereinafter, some examples of the degree of arteriosclerosis will be described. In addition, the measuring method of each index is not limited to the one described here, and can be measured by various methods.

  For example, ABI (Ankle Brachial Index) is used for the examination of blood flow disorders in the lower limb blood vessels.

  ABI is a value obtained by dividing the value of the systolic blood pressure of the ankle by the value of the systolic blood pressure of the upper arm, and is sometimes called API or ABPI. As an index similar to ABI, there is an index called TBI (Toe Pressure Index). TBI is a value obtained by dividing the value of systolic blood pressure of the toes (toes) by the value of systolic blood pressure in the upper arm, and is sometimes called TPI or TBPI.

  For the examination of arterial extensibility, for example, aortic PWV (Pulse Wave Velocity) (see, for example, Non-Patent Document 1) and baPWV (brachial-ankle Pulse Wave Velocity: upper arm-ankle PWV) (for example, see Non-Patent Document 2) ), CAVI (Cardio-Ankle Vascular Index) (for example, see Non-Patent Document 3) and the like.

  PWV is a pulse wave velocity, and is a value having a velocity unit obtained by dividing the value of the distance between two different points on the blood vessel by the value of the time difference between the pulse waves at the two points. For measuring the pulse wave, for example, various types of pulse wave sensors such as an air conduction type, a photoelectric type, an air bag type, an amorphous type, and a tonometry type are used. Further, the aorta, which is an elastic artery, may be adopted as a target site for PWV measurement, and the PWV measured in the aorta is referred to as the aorta PWV. There are mainly two methods for measuring the aortic PWV.

In one aorta PWV measurement method, for example, the aorta PWV is obtained by the following equation (1).
PWV = (b + c−a) / ΔT (1)
Here, ΔT is the time difference between the pulse wave rising part at the carotid artery part and the pulse wave rising part at the femoral artery part, a is the distance from the suprasternal fossa to the carotid artery part, b is C is the distance from the umbilicus to the femoral artery.

In the other aorta PWV measurement method, for example, the aorta PWV is obtained by the following equation (2).
PWV = D × 1.3 / (ΔT + Tc) (2)
Here, ΔT is a time difference between the pulse wave rising portion in the carotid artery portion and the pulse wave rising portion in the femoral artery portion, and Tc is from the start of the heart II sound (heart sound generated when the aortic valve is closed). It is the time to the notch of the pulse wave in the carotid artery, and D is the linear distance from the right edge of the 2nd intercostal sternum where the heart sound microphone for measuring heart II sound is placed to the femoral artery Yes, 1.3 is an anatomical correction value.

For example, baPWV is obtained by the following equation (3).
baPWV = (La−Lb) / Tba (3)
Here, Tba is the time difference between the pulse wave rising part at the upper arm and the pulse wave rising part at the ankle, each measured using a cuff, and La is the distance from the aortic valve opening to the ankle. , Lb is the distance from the aortic valve opening to the upper arm.

ここで、Ｐｓは、上腕の収縮期血圧であり、Ｐｄは、上腕の拡張期血圧であり、ρは血液密度であり、ΔＰは、Ｐｓ−Ｐｄである。また、ＰＷＶは、脈波伝播速度であり、例えば次の式（５）により求められる。

ここで、Ｔｂは、心II音の開始から上腕での脈波の切痕部までの時間であり、Ｔｂａは、上腕での脈波立ち上がり部と足首での脈波立ち上がり部との時間差であり、Ｄは、心II音を計測する心音マイクが置かれた胸骨右縁第II肋間から大腿動脈部までの直線距離であり、１．３は解剖学的補正値であり、Ｌ２は、大腿動脈部から膝関節中央部までの直線距離であり、Ｌ３は、膝関節中央部から足首カフ装着中央部までの直線距離である。 In CAVI measurement, a cuff is attached to the upper arm and ankle (or popliteal area) to measure blood pressure and pulse wave, and a heart sound microphone is attached to the sternum to measure heart sounds. CAVI is obtained by the following equation (4), for example.

Here, Ps is the systolic blood pressure of the upper arm, Pd is the diastolic blood pressure of the upper arm, ρ is the blood density, and ΔP is Ps−Pd. Moreover, PWV is a pulse wave propagation velocity and is calculated | required by following Formula (5), for example.

Here, Tb is the time from the start of the heart II sound to the pulse wave notch on the upper arm, and Tba is the time difference between the pulse wave rising part on the upper arm and the pulse wave rising part on the ankle. , D is the linear distance from the right heel of the sternum to the femoral artery where the heart sound microphone for measuring heart II sound is placed, 1.3 is the anatomical correction value, and L2 is the femoral artery L3 is a linear distance from the knee joint central part to the ankle cuff wearing central part.

  As can be seen from the above description, detection of the rising portion of the pulse wave is necessary to calculate the degree of arteriosclerosis related to the arterial extensibility test. As a method for detecting the pulse wave rising portion, for example, there is one described in Patent Document 1. In the technique disclosed in this document, a pulse wave rising portion within the cycle is detected based on the bottom and peak portions of the pulse wave within the same cycle.

When the pulse wave rising portion is detected, the degree of arteriosclerosis is calculated by the above-described method. The calculated degree of arteriosclerosis is printed on, for example, a report sheet. The measured pulse wave waveform is also printed on, for example, a report sheet. A user (for example, a doctor or a laboratory technician) can subjectively determine whether or not the waveform has a good quality as a sample by looking at the printed waveform. For example, when it is determined that the waveform quality is not good and the waveform measurement accuracy is not high, the user can remeasure the pulse wave.
JP 2004-33614 A Yoshiaki Masuda, Hiroshi Kanai, “Fundamental and Clinical Arterial Pulse Waves”, Kyoritsu Shuppan, 15-19 pages, 2000 Toshio Ozawa, Yoshiaki Masuda, "Pulse wave velocity", Medical View, 28-29 pages Kohji Shirai, Junji Utino, Kuniaki Ohtsuka, Masanobu Takada, "A Novel Blood Pressure-independent Arterial Wall Stiffness Parameter; Cardio-Ankle Vascular Index (CAVI)", Journal of Atherosclerosis and Thrombosis, Vol.13, No.2

  However, in the conventional blood pressure pulse wave inspection device, information for supporting the determination of pulse wave waveform quality is not provided in a timely manner during pulse wave measurement. Even high users have certain limitations in improving the reliability and efficiency of arteriosclerosis tests.

  The present invention has been made in view of such a point, and an object thereof is to provide a biological information processing apparatus and a biological information processing method that can improve the reliability and efficiency of an arteriosclerosis test.

  The biological information processing apparatus of the present invention includes a pulse wave acquisition unit that acquires a pulse wave of a subject, a detection unit that detects a feature point of the acquired pulse wave, and a feature point of the detected pulse wave. And a display unit that displays the acquired waveform of the pulse wave on the screen in real time.

  The biological information processing method of the present invention detects a pulse wave acquisition step for acquiring a pulse wave of a subject and a feature point of the acquired pulse wave used for calculation of the degree of arteriosclerosis of the subject. A detection step; and a display step of displaying the acquired waveform of the pulse wave on the screen in real time while clearly indicating the detected feature point of the pulse wave.

  According to the present invention, the reliability and efficiency of an arteriosclerosis test can be improved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of a biological information processing apparatus according to an embodiment of the present invention. This biological information processing apparatus can be applied to various medical devices, but is particularly suitable for use as a blood pressure pulse wave inspection apparatus.

  The biological information processing apparatus includes an arithmetic control unit 10, a display unit 70, a recording unit 75, a storage unit 80, a sound generation unit 85, an input / instruction unit 90, an upper limb measurement control unit 201, a lower limb measurement control unit 202, and a heart sound. The measurement unit 203, the electrocardiogram measurement unit 204, and the pulse wave measurement unit 205 are integrated by being housed in a housing of the main body. Two cuffs 21R and 21L are connected to the upper limb measurement control unit 201 via hose 21h, and two cuffs 22R and 22L are connected to the lower limb measurement control unit 202 via hose 22h, respectively. The heart sound measuring unit 203 is connected to the heart sound microphone 23, the electrocardiogram measuring unit 204 is connected to the limb electrocardiographic electrode unit 24 a and the chest electrocardiographic electrode unit 24 b, and the pulse wave measuring unit 205. Are connected to amorphous pulse wave sensors 25a and 25b. The upper limb measurement control unit 201 and the lower limb measurement control unit 202 constitute a blood pressure pulse wave measurement unit 200 of this biological information processing apparatus.

  The arithmetic control unit 10 is a general-purpose computer device having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), various interfaces, and the like. The arithmetic control unit 10 controls and executes the operation of the entire apparatus described below by executing a control program stored in a built-in memory or an external storage device by the CPU. The control of the entire apparatus by the arithmetic control unit 10 may be realized only by software, or may be realized by a combination of software and hardware.

  The arithmetic control unit 10 also measures an upper limb measurement control unit 201, a lower limb measurement control unit 202, a heart sound measurement unit 203, an electrocardiogram measurement unit 204, and a pulse wave measurement unit 205 (hereinafter referred to as “biological information”). The measurement of the “collection unit” is generally controlled.

  Further, the arithmetic control unit 10 receives biological information supplied from each biological information measuring unit. The received biometric information is edited or converted into display data when it is necessary to display it on the screen, and then edited or converted into print data when it is necessary to print it on the report paper. After that, the data is output to the recording unit 75. The arithmetic control unit 10 appropriately stores the received biological information in the storage unit 80 and reads the stored biological information.

  In addition, the arithmetic control unit 10 as a detecting unit analyzes a waveform obtained from the biological information received from each biological information measuring unit. The analysis of the waveform includes detection of feature points in the waveform. The feature point detection will be described in detail later.

  The arithmetic control unit 10 calculates the degree of arteriosclerosis based on the analysis result and the numerical value indicated by the received biological information. Since the degree of arteriosclerosis that can be calculated and its calculation formula have already been described, they are omitted here. The arithmetic control unit 10 also edits or converts the arteriosclerosis degree and the waveform analysis result into display data when necessary to be displayed on the screen, as in the case of biological information, and then displays the report on a report sheet. When printing is necessary, the data is edited or converted into print data and output to the recording unit 75. In addition, the arithmetic control unit 10 appropriately stores the degree of arteriosclerosis and the analysis result in the storage unit 80 and reads out the stored information.

  The arithmetic control unit 10 as an evaluation unit performs various determination processes on the biological information, the degree of arteriosclerosis, and the waveform analysis result. The determination process includes an evaluation of the quality of the waveform obtained from the received biological information. The evaluation of the waveform quality will be described in detail later. Further, the calculation control unit 10 also edits or converts the result of this determination into display data when it is necessary to display it on the screen, like the degree of arteriosclerosis and the biological information, and then displays the report on the display unit 70. When it is necessary to print on paper, it is edited or converted into print data and output to the recording unit 75. In addition, the arithmetic control unit 10 appropriately stores the determination result in the storage unit 80 and reads out the stored determination result. In addition, the arithmetic control unit 10 outputs a signal instructing the output of the notification sound to the sound generation unit 85 according to the determination result.

  Further, the arithmetic control unit 10 outputs guidance data to the voice generation unit 85 when voice guidance for assisting the user's operation is necessary.

  Further, the arithmetic control unit 10 receives the contents of the input and instruction by the user's operation from the input / instruction part 90, and according to the received contents, each biological information measuring unit, display unit 70, recording unit 75, storage unit 80, voice Settings related to the function of the generation unit 85 are made, and the start and stop of each operation are controlled.

  The display unit 70 has a display screen or the like as a main component, and displays biological information, waveform analysis results, arteriosclerosis degrees, and determination results input as display data from the arithmetic control unit 10 on the screen. The screen display will be described in detail later.

  The recording unit 75 has a paper feed mechanism, a print head, and the like as main components, and prints biometric information, waveform analysis result, arteriosclerosis degree, and determination result input as print data from the arithmetic control unit 10 on a sheet. .

  The storage unit 80 includes a hard disk drive, a writable optical disk drive, a nonvolatile memory, and the like, and can hold information from the arithmetic control unit 10.

  The sound generation unit 85 has a speaker or the like as a main component, and generates a guidance sound or a notification sound in accordance with guidance data or a notification sound output instruction signal input from the arithmetic control unit 10.

  The input / instruction unit 90 includes a keyboard, a mouse, buttons, a touch panel, and the like, and enables input and instructions by user operations. The contents of user input and instructions are notified to the arithmetic control unit 10.

  The pulse wave measurement unit 205 is an amorphous pulse wave acquisition unit. The pulse wave measurement unit 205 measures the pulse wave by supplying the pulse wave signal of the subject detected by the amorphous pulse wave sensors 25a and 25b attached to the subject to the arithmetic control unit 10. . The pulse wave measurement by the pulse wave measurement unit 205 is preferably used when the arithmetic control unit 10 obtains the aorta PWV. In this case, one of the amorphous pulse wave sensors 25a and 25b is the carotid part of the subject. The other is attached to the femoral artery of the subject.

  The electrocardiogram measurement unit 204 as an electrocardiogram acquisition means supplies the electrocardiogram signals detected by the limb electrocardiogram electrode unit 24a and the chest electrocardiogram electrode unit 24b attached to the subject to the arithmetic control unit 10, thereby Measure. The limb electrocardiogram electrode portion 24a typically includes four electrocardiogram electrodes attached to the right wrist, the left wrist, the right ankle, and the left ankle, respectively. The electrocardiographic electrodes for both ankles are preferably formed so as not to be hindered by the cuffs 22R and 22L attached to the lower limbs. Moreover, the electrocardiogram electrode portion 25b for the chest is typically composed of six electrocardiographic electrodes that are respectively attached to six locations on the chest.

  A heart sound measurement unit 203 as a heart sound acquisition unit supplies a heart sound signal detected by the heart sound microphone 23 attached to the subject to the arithmetic control unit 10 to measure heart sounds.

  In the present embodiment, the blood pressure pulse wave measurement unit 200 includes an upper limb measurement control unit 201 and a lower limb measurement control unit 202, but the upper limb measurement control unit 201 and the lower limb measurement control unit 202 are provided. The unit 202 may be integrated.

  The blood pressure pulse wave measurement unit 200 is an oscillometric blood pressure pulse wave acquisition unit, and has both functions of a blood pressure acquisition unit and a pulse wave acquisition unit. The upper limb measurement control unit 201 of the blood pressure pulse wave measurement unit 200 includes a pump, an exhaust valve, a CPU, and a memory in addition to the two pressure sensors 211R and 211L. The memory stores a program for controlling blood pressure measurement by the pump, exhaust valve, cuffs 21R and 21L and pulse wave measurement by cuffs 21R and 21L, and setting information related to this control. The measurement control unit 201 for the upper limb executes a program according to the setting information by the CPU. The measurement control unit 201 for the upper limbs uses the pump and the exhaust valve to pressurize the cuffs 21R and 21L by introducing air into the rubber sac 21aR and 21aL of the cuff 21R and cuff 21L through the hose 21h. The cuffs 21R and 21L are decompressed by discharging air from the rubber bags 21aR and 21aL. The cuff 21R indicates a cuff attached to the upper right arm, and the cuff 21L indicates a cuff attached to the left upper arm. The target value of the cuff pressure after pressurization is different for pulse wave measurement and blood pressure measurement, and can be set individually.

  The upper limb measurement control unit 201 detects the cuff pressure fluctuations of the cuffs 21R and 21L after the cuff pressurization as pulse wave signals by the pressure sensors 211R and 211L, and the detected pulse wave signal is sent to the arithmetic control unit 10. By supplying, the pulse wave is measured. Note that only one of the two cuffs 21R and 21L may be used for pulse wave measurement, or both may be used.

  Further, the upper limb measurement control unit 201 detects the cuff pressure with the most remarkable increase in amplitude as the systolic blood pressure while detecting the cuff pressure vibrations of the cuffs 21R and 21L by the pressure sensors 211R and 211L during the cuff pressure reduction. At the same time, the cuff pressure with the most significant vibration reduction is detected as the diastolic blood pressure, and the blood pressure signal is measured by supplying the blood pressure signals respectively indicating the detected systolic blood pressure and diastolic blood pressure to the arithmetic control unit 10. I do. The upper limb measurement control unit 201 can separately measure the right blood pressure using only the cuff 21R and the left blood pressure using only the cuff 21L. Further, the systolic blood pressure and the diastolic blood pressure can be detected from the vibrating cuff pressure by the arithmetic control unit 10 instead of the upper limb measurement control unit 201.

  The lower limb measurement control unit 202 of the blood pressure pulse wave measurement unit 200 includes a pump, an exhaust valve, a CPU, and a memory in addition to the two pressure sensors 221R and 221L. The memory stores a program for controlling blood pressure measurement by the pump, exhaust valve, cuffs 22R, 22L and pulse wave measurement by the cuffs 22R, 22L, and setting information related to this control. The lower limb measurement control unit 202 executes a program according to the setting information by the CPU. The lower limb measurement control unit 202 uses the pump and the exhaust valve to pressurize the cuffs 22R and 22L by introducing air into the rubber sac 22aR and 22aL of the cuff 22R and cuff 22L through the hose 22h. The cuffs 22R and 22L are depressurized by discharging air from the rubber pouches 22aR and 22aL. The cuff 22R indicates a cuff attached to the right ankle, and the cuff 22L indicates a cuff attached to the left ankle. The target value of the cuff pressure after pressurization is different for pulse wave measurement and blood pressure measurement, and can be set individually.

  Further, the measurement control unit 202 for the lower limbs detects a change in the cuff pressure of the cuffs 22R and 22L after the cuff pressurization as a pulse wave signal by the pressure sensors 221R and 221L, and the detected pulse wave signal is sent to the arithmetic control unit 10. By supplying, the pulse wave is measured. Note that only one of the two cuffs 22R and 22L may be used for pulse wave measurement, or both may be used.

  In addition, the measurement control unit 202 for the lower limbs detects the cuff pressure in which the fluctuation is remarkable as the systolic blood pressure while detecting the fluctuation of the cuff pressure of the cuffs 22R and 22L by the pressure sensors 221R and 221L during the cuff pressure reduction. At the same time, the cuff pressure in which the decrease in fluctuation is significant is detected as the diastolic blood pressure, and the blood pressure is measured by supplying the blood pressure signals respectively indicating the detected systolic blood pressure and diastolic blood pressure to the arithmetic control unit 10. . Note that the lower limb measurement control unit 202 can separately perform measurement of the right blood pressure using only the cuff 22R and measurement of the left blood pressure using only the cuff 22L. Further, the systolic blood pressure and the diastolic blood pressure can be detected from the vibrating cuff pressure by the arithmetic control unit 10 instead of the lower limb measurement control unit 202.

  The configuration of the biological information processing apparatus according to the present embodiment has been described above.

  Next, screen display by the display unit 70 of the biological information processing apparatus will be described with reference to an example of the screen display shown in FIG.

  A plurality of waveforms are displayed on the screen in real time, that is, substantially simultaneously with the measurement of biological information. More specifically, when the electrocardiogram signal, the heart sound signal, and the pulse wave signal are supplied from the electrocardiogram measurement unit 204, the heart sound measurement unit 203, and the blood pressure pulse wave measurement unit 200 to the calculation control unit 10, the calculation control unit 10 immediately The display waveform data for displaying the waveform obtained based on the supplied information on the screen is generated and supplied to the display unit 70. When the display waveform data is supplied, the display unit 70 immediately displays it on the screen.

  In the example of FIG. 2, six waveforms are displayed with the horizontal axis representing time and the vertical axis representing measured values of biological information. These waveforms translate in the right-hand direction as the measurement time elapses. The top waveform is an electrocardiogram waveform, the second waveform from the top is an electrocardiogram, the third waveform from the top is the right upper arm pulse waveform, and the fourth waveform from the top is the left upper arm This is a pulse waveform, the fifth waveform from the top is the right ankle pulse waveform, and the lowermost waveform is the left ankle pulse waveform.

  Further, a vertical line called a dividing line is displayed on the screen so as to be superimposed on the heart waveform and the pulse wave waveform. The division line clearly indicates the feature points of each period in each waveform (detection of the feature points is performed by the arithmetic control unit 10, which will be described later) on the screen so that the user can easily understand the position of the feature points. The display object is a line that intersects the waveform at the feature point. The dividing line is displayed substantially simultaneously with the display of the corresponding feature points. In the example of FIG. 2, the dividing line clearly indicates a feature point that specifies a section corresponding to a parameter (that is, Tb and Tba in the above formula (5)) used for calculating CAVI. Such feature points include a rising part of heart II sound in the heart sound waveform and a pulse wave rising part and a notch part in the pulse waveform.

  In this way, since the division line is provided in a timely manner as basic information for supporting the determination of the pulse waveform quality during pulse wave measurement, the user can quickly make a subjective determination on the pulse waveform quality. This can improve the reliability and efficiency of the arteriosclerosis test. In addition, since the division line is provided in a timely manner as information for supporting the determination of the heart sound waveform quality, the user can quickly make a subjective determination of the heart sound waveform quality, Efficiency can be improved.

  Furthermore, marks (including characters, symbols, icons, and the like) corresponding to the evaluation result of the pulse wave waveform quality are also displayed on the screen near the corresponding pulse wave waveform. The mark is a display object for clearly indicating the evaluation result of the quality of the pulse wave waveform on the screen so that the user can easily understand the quality of the pulse wave waveform, and is displayed substantially simultaneously with the division lines belonging to the same cycle. The quality of the pulse waveform is evaluated by the arithmetic control unit 10, thereby obtaining an evaluation result. In this example, the arithmetic control unit 10 evaluates the pulse wave waveform quality of each cycle in four stages by determining the reproducibility of the pulse wave waveform with a specific algorithm. The display unit 70 displays the highest quality as “◎”, the second highest quality as “◯”, the third highest quality as “△”, and the lowest quality as “×”. .

  In this way, the evaluation result of the pulse wave waveform quality obtained by using the specific algorithm by the arithmetic control unit 10 is applied in a timely manner as additional information for supporting the determination of the pulse wave waveform quality at the time of pulse wave measurement. Therefore, the user can objectively determine the pulse wave waveform quality, and can further improve the reliability and efficiency of the arteriosclerosis test.

  Next, feature point detection by the arithmetic control unit 10 of the biological information processing apparatus will be described. The characteristic points necessary for the calculation of CAVI are the heart II sound rising part, the pulse wave notch part of the upper arm, the pulse wave rising part of the upper arm, and the waveform rising part of the lower leg. Therefore, here, the upper arm pulse wave peak and upper arm pulse wave bottom, the upper arm pulse wave riser, the heart II sound riser, and the upper arm pulse are the characteristic points necessary for detecting the upper arm pulse wave riser. The detection of the wave notch portion will be described with reference to FIGS. 3 to 9 in order. 3 to 9, (a) shows an electrocardiogram waveform, (b) shows a cardiac sound waveform, (c) shows a pulse waveform, and these waveforms are an electrocardiogram, a heart sound and a pulse detected at the same timing. It is a waveform obtained from a wave.

  FIG. 3 shows a first stage of feature point detection, where the pulse wave peak portion C1 is detected as a feature point. Specifically, the R wave of the electrocardiogram waveform is first detected, and the first maximum point in the pulse wave after the R wave detection is detected as the pulse wave peak portion C1. Generally, the pulse wave peak portion C1 of the upper arm is located behind about 250 ms from the R wave.

  This local maximum point can be detected by performing smoothing differentiation of the measurement value of the pulse wave at every measurement timing, and is one of zero cross points of the smoothing differentiation value. It is preferable to set more points for smoothing differentiation. As a result, it is possible to avoid erroneous detection of a relatively small notch portion having a frequency component much larger than the frequency of the pulse wave as a maximum point.

  FIG. 4 shows a second stage of feature point detection. Here, the pulse wave bottom C2 is detected as a feature point. Specifically, the first minimum point is detected as the pulse wave bottom portion C2 by tracing the pulse wave waveform in the direction going back from the pulse wave peak portion C1. In general, the pulse wave bottom portion C2 is located about 150 ms before the pulse wave peak portion C1.

  FIG. 5 shows a third stage of feature point detection. Here, the pulse wave rising portion C4 is detected as a feature point. Specifically, first, a straight line L1 that intersects the waveform is obtained at the coordinates when the pulse wave bottom portion C2 is traced back by a predetermined period. The straight line L1 has an inclination θ determined from a difference value in height between the pulse wave peak portion C1 and the pulse wave bottom portion C2, and a value for a predetermined period. Then, the pulse wave rising search period D1 from the pulse wave bottom C2 to the inflection point C3 of the pulse wave waveform is specified. In the pulse wave rising search period D1, the point on the waveform that is perpendicular to the straight line L1 and that connects the straight line L1 and the pulse wave waveform has the longest length, in other words, the distance from the straight line L1. The point on the waveform that becomes the largest is detected as the pulse wave rising portion C4. Details of the feature point detection at this stage are disclosed in Patent Document 1.

  FIG. 6 shows a fourth stage of feature point detection. Here, the heart II sound peak portion C5 is detected as a feature point. Specifically, first, a mask period D2 having a certain length of time from the time of the R wave (usually about 250 ms, variable with reference to the subject's standard RT interval), and from the mask period end time A heart sound rising search period D3 having a certain time length (usually about 200 ms) is specified. Then, the heart sound waveform in the mask period D2 is masked, and the maximum point in the heart sound rising search period D3 is detected as the heart II sound peak portion C5.

  FIG. 7 shows a fifth stage of feature point detection. Here, the heart II sound rising portion C6 is detected as a feature point. Specifically, first, an envelope E1 having a heart sound waveform is generated over at least the heart sound rising search period D3. And the heart II sound rising part C6 is detected by applying the detection method similar to a 3rd step with respect to the envelope E1. In general, the heart II sound rising portion C6 is located about 300 ms behind the R wave.

  FIG. 8 shows a sixth stage of feature point detection, where a notch search period D4 is specified. The notch search period D4 is a section from the start point C7 to the end point C8 in the pulse wave waveform. The starting point C7 is located at the same time as the first upward convex portion on the heart sound waveform located about 40 ms behind from the time of the heart II sound rising portion C6. The end point C8 is located at the same time as the upward convex portion on the heart sound waveform located about 140 ms behind the heart II sound rising portion C6. After specifying the notch search period D4, a straight line L3 connecting the start point C7 and the end point C8 is obtained.

  FIG. 9 shows a seventh stage of feature point detection. Here, a pulse wave notch C9 is detected as a feature point. The pulse wave notch portion C9 is a point where the distance from the straight line L3 becomes the largest in the notch search period D4.

  As described above, feature points of each waveform are detected. In this feature point detection, the pulse wave rising portion C4 can be detected about 250 ms after the R wave detection, and the heart II sound rising portion C6 can be detected about 450 ms after the R wave detection, and the pulse wave notch of the upper arm can be detected. Part C9 can be detected about 440 ms after the R-wave detection. Therefore, detection of feature points necessary for calculating CAVI can be completed about 450 ms after the R wave detection. Then, the division lines can be displayed in a superimposed manner with a slight delay with respect to the real-time display of the waveform, that is, with good followability. In the conventional general feature point detection, the maximum point of the pulse wave waveform corresponding to the RR interval is detected as the pulse wave peak portion. Therefore, the detection of the pulse wave peak portion corresponds to the RR interval. It took at least time (1 second if the heart rate was 60). On the other hand, in the feature point detection of the present embodiment, the time required for detecting the pulse wave peak portion is significantly shortened, thereby reducing the time required for detecting the feature points necessary for CAVI calculation. The display of the waveform and the dividing line almost simultaneously is reliably realized.

  The embodiment of the present invention has been described above. The above description is an illustration of a preferred embodiment of the present invention, and the scope of the present invention is not limited to this. That is, the description of the configuration and operation of the above apparatus is an example, and it is apparent that various modifications and additions to these examples are possible within the scope of the present invention.

The block diagram which shows the structure of the biological information processing apparatus which concerns on one embodiment of this invention The figure for demonstrating the screen display which concerns on one embodiment of this invention The figure for demonstrating the 1st step of the feature point detection which concerns on one embodiment of this invention The figure for demonstrating the 2nd step of the feature point detection which concerns on one embodiment of this invention The figure for demonstrating the 3rd step of the feature point detection which concerns on one embodiment of this invention The figure for demonstrating the 4th step of the feature point detection which concerns on one embodiment of this invention The figure for demonstrating the 5th step of the feature point detection which concerns on one embodiment of this invention The figure for demonstrating the 6th step of the feature point detection which concerns on one embodiment of this invention The figure for demonstrating the 7th step of the feature point detection which concerns on one embodiment of this invention

Explanation of symbols

10 Arithmetic Control Unit 21R, 21L, 22R, 22L Cuff 21aR, 21aL, 22aR, 22aL Rubber Sac 21h, 22h Hose 23 Heart Sound Microphone 24a Limb Electrocardiogram Electrode 24b Chest Electrocardiogram Electrode 25a, 25b Amorphous Pulse Wave Sensor 70 Display Unit 75 recording unit 80 storage unit 85 sound generation unit 90 input / instruction unit 200 blood pressure pulse wave measurement unit 201 upper limb measurement control unit 202 lower limb measurement control unit 203 heart sound measurement unit 204 electrocardiogram measurement unit 205 pulse wave measurement unit 211R, 211L 221R, 221L Pressure sensor

Claims (9)

Pulse wave acquisition means for acquiring the pulse wave of the subject;
Detecting means for detecting the characteristic points of the acquired pulse wave;
Display means for displaying the acquired waveform of the pulse wave in real time on the screen while clearly indicating the characteristic points of the detected pulse wave;
A biological information processing apparatus characterized by comprising:   The biological information processing apparatus according to claim 1, wherein the detection unit detects a rising portion and a notch portion of the pulse wave as characteristic points of the pulse wave. A heart sound acquisition means for acquiring the heart sound of the subject;
The detection means detects a feature point of the acquired heart sound,
The biological information processing apparatus according to claim 1, wherein the display unit displays the acquired waveform of the heart sound on the screen in real time while clearly indicating a feature point of the detected heart sound.   The biological information processing apparatus according to claim 3, wherein the detection unit detects a rising portion of a heart II sound in the heart sound as a feature point of the heart sound.   The display means displays a line that intersects the acquired waveform of the pulse wave or the acquired waveform of the heart sound at the detected feature point of the pulse wave or the detected feature point of the heart sound with the screen. The biological information processing apparatus according to claim 1, wherein the biological information processing apparatus is displayed. An evaluation means for evaluating the waveform quality of the detected pulse wave;
The biological information processing apparatus according to claim 1, wherein the display unit displays the acquired waveform of the pulse wave on the screen in real time while clearly indicating the evaluation result of the waveform quality. An electrocardiogram acquisition means for acquiring an electrocardiogram of the subject;
The detection means detects an R wave of the acquired electrocardiogram, detects an initial maximum point after the detection of the R wave in the acquired pulse wave as a peak portion of the pulse wave, and is detected 2. The living body according to claim 1, wherein an initial rising portion after detection of the R wave in the acquired pulse wave is detected as a feature point of the pulse wave based on a peak portion of the pulse wave. Information processing device.   The biological information processing apparatus according to claim 7, wherein the detection unit detects the maximum point by performing smoothing differentiation on the acquired value of the pulse wave. A pulse wave acquisition step for acquiring the pulse wave of the subject;
A detection step for detecting a feature point of the acquired pulse wave, which is used to calculate the degree of arteriosclerosis of the subject;
A display step of displaying the acquired waveform of the pulse wave on the screen in real time while clearly indicating the feature point of the detected pulse wave;
A biological information processing method characterized by comprising:

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