Blood pressure pulse wave analysis device and blood pressure pulse wave analysis method

Abstract

To provide a blood pressure pulse wave measuring device and a blood pressure pulse wave measuring method capable of suppressing deterioration in reliability of an arteriosclerosis examination due to tension or the like felt by a subject.SOLUTION: A blood pressure pulse wave measuring device includes: a blood pressure pulse wave measuring part for measuring the blood pressure pulse wave of a subject; a heartbeat analysis part for detecting a rest state of the subject by analyzing a heartbeat trend of the subject; an extraction part for extracting the blood pressure pulse wave when the rest state of the subject is detected by the heartbeat analysis part, of the blood pressure pulse wave measured by the blood pressure pulse wave measuring part; and a degree-of-arteriosclerosis calculation part for calculating an index of the arteriosclerosis of the subject using the blood pressure pulse wave extracted by the extraction part.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a blood pressure pulse wave inspection device and a blood pressure pulse wave inspection method for calculating arteriosclerosis indices such as CAVI (Cardio Ankle Vascular Index) and PWV (Pulse Wave Velocity) from measured pulse waves.

Background Art

[0002] Conventionally, CAVI and PWV are generally used as arteriosclerosis indices. PWV is the speed at which the wave generated when the heart pumps blood into the aorta travels along the arterial blood vessel wall, and the faster it is, the harder the blood vessel is. PWV is obtained by measuring the pulse waves at two points on the blood vessel and their propagation time (PWT), and dividing the distance between these two points by the propagation time.

[0003] A blood pressure pulse wave inspection device capable of measuring PWV is described in, for example, Patent Document 1. A blood pressure pulse wave inspection device capable of measuring CAVI in addition to PWV is described in, for example, Patent Document 2.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, it is known that the hardness of the blood vessel is affected by the autonomic nerve and the like, and it increases when the vascular smooth muscle contracts during tension. Therefore, when measuring the hardness of the blood vessel, it is measured in a state of sufficient rest and no tension.

[0006] However, the examiner cannot know how nervous each subject is, and it is also difficult for the subject themselves to know. Therefore, if, for example, arteriosclerosis is measured when the subject is nervous, there is a risk of obtaining an inaccurate test result, such as the arteriosclerosis being more advanced than it actually is.

[0007] This invention has been made in consideration of the above points, and provides a blood pressure pulse wave testing device and a blood pressure pulse wave testing method that can suppress the decrease in reliability of arteriosclerosis testing caused by the subject's tension, etc. [Means for solving the problem]

[0008] One aspect of the blood pressure pulse wave testing device of the present invention is A blood pressure pulse wave measurement unit that measures the blood pressure pulse wave of the subject, The heart rate analysis unit detects the subject's resting state by analyzing the subject's heart rate trend, An extraction unit that extracts the blood pressure pulse wave from the blood pressure pulse wave measured by the blood pressure pulse wave measurement unit when the heart rate analysis unit detects the subject's resting state, An arteriosclerosis degree calculation unit calculates an index of arteriosclerosis in the subject using the blood pressure pulse wave extracted by the extraction unit, It is equipped with.

[0009] One embodiment of the blood pressure pulse wave examination method of the present invention is: The steps include measuring the blood pressure and pulse wave of the subject, The procedure involves analyzing the subject's heart rate trend to detect the subject's resting state, and The steps include: extracting the blood pressure pulse wave from the measured blood pressure pulse wave when the subject is in a resting state; The steps include: calculating an index of arteriosclerosis in the subject using the extracted blood pressure pulse wave; Includes. [Effects of the Invention]

[0010] According to the present invention, it becomes possible to calculate an index of arteriosclerosis using the blood pressure pulse wave at rest, thereby realizing a blood pressure pulse wave testing device and method that can suppress the decrease in reliability of arteriosclerosis tests caused by the subject's tension, etc. [Brief explanation of the drawing]

[0011] [Figure 1] Block diagram showing the overall configuration of the blood pressure pulse wave analysis device according to the embodiment. [Figure 2] Block diagram showing the main components for realizing the blood pressure pulse wave examination apparatus and method according to the embodiment. [Figure 3] Figure 3A shows an example of blood pressure pulse wave display according to the embodiment, and Figure 3B shows a magnified view of the heart rate trend (HR trend). [Figure 4] A diagram showing the flow of blood pressure and pulse wave measurement using a blood pressure and pulse wave analysis device. [Modes for carrying out the invention]

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0013] <1> Overall configuration of a blood pressure and pulse wave analysis device Figure 1 is a block diagram showing the overall configuration of a blood pressure pulse wave analysis device according to an embodiment of the present invention.

[0014] In Figure 1, the main body 1a of the blood pressure pulse wave testing device 1 is equipped with a calculation processing unit 10, an input unit 70, a display unit 80, a display control unit 81, a printing unit 91, a storage unit 92, an audio output unit 93, a blood pressure pulse wave measurement unit 30, a heart sound measurement unit 40, an electrocardiogram measurement unit 50, and a pulse wave measurement unit 60.

[0015] The blood pressure pulse wave measurement unit 30 includes an upper arm measurement control unit 31 and a lower limb measurement control unit 32. The upper arm measurement control unit 31 is connected to the right upper arm cuff 21R and the left upper arm cuff 21L via hoses 21h, and the lower limb measurement control unit 32 is connected to the right ankle cuff 22R and the left ankle cuff 22L via hoses 22h.

[0016] The blood pressure and pulse wave measurement unit 30 has an oscillometric blood pressure measurement function and an air bag type pulse wave measurement function.

[0017] The upper limb measurement control unit 31 includes a pressure sensor 33, a signal processing circuit that performs predetermined signal processing such as amplification on the detection signal from the pressure sensor 33, a pump and an exhaust valve for supplying and discharging air to and from the cuffs 21R and 21L, and a computer having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), various interfaces, etc. that controls this air supply and discharge operation. The upper limb measurement control unit 31 pressurizes the internal pressure of the cuffs 21R and 21L (hereinafter, the internal pressure of the cuff is referred to as "cuff pressure") by introducing air into the rubber bladders of the cuffs 21R and 21L via the hose 21h, and减压 the cuff pressure of the cuffs 21R and 21L by discharging air from the rubber bladders. The cuff 21R is attached to the right upper arm of the subject, and the cuff 21L is attached to the left upper arm of the subject. The target value of the cuff pressure after pressurization is different for pulse wave measurement and blood pressure measurement, and can be set individually.

[0018] In the case of pulse wave measurement, the upper limb measurement control unit 31 detects the fluctuation of the cuff pressure of the cuffs 21R and 21L after pressurization as a pulse wave signal with the pressure sensor 33, and outputs the detected pulse wave signal to the arithmetic processing unit 10. Pulse wave measurement is performed in response to a request from the arithmetic processing unit 10. Note that for pulse wave measurement, only one of the two cuffs 21R and 21L may be used, or both may be used.

[0019] In the case of blood pressure measurement, the upper limb measurement control unit 31 detects the vibration of cuff pressure of cuffs 21R and 21L using the pressure sensor 33 during decompression, and detects the cuff pressure with the most significant increase in amplitude as the systolic blood pressure, and the cuff pressure with the most significant decrease in vibration as the diastolic blood pressure. The upper limb measurement control unit 31 then outputs blood pressure signals indicating the detected systolic and diastolic blood pressures, respectively, to the calculation processing unit 10. Blood pressure measurement is performed in response to a request from the calculation processing unit 10. Normally, when a request is made from the calculation processing unit 10, right-side blood pressure measurement using only cuff 21R and left-side blood pressure measurement using only cuff 21L are performed sequentially, but these blood pressure measurements may be performed in parallel.

[0020] The lower limb measurement control unit 32 includes a pressure sensor 34, a signal processing circuit that performs predetermined signal processing such as amplification on the detection signal from the pressure sensor 34, a pump and exhaust valve for supplying and exhausting air to the cuffs 22R and 22L, and a computer having a CPU, ROM, RAM, various interfaces, etc., that controls this supply and exhaust operation. The lower limb measurement control unit 32 pressurizes the cuffs 22R and 22L by introducing air into the rubber sacs of the cuffs 22R and 22L via the hose 22h, and depressurizes the cuffs 22R and 22L by expelling air from the rubber sacs. Cuff 22R is attached to the subject's right ankle, and cuff 22L is attached to the subject's left ankle. The target value of the cuff pressure after pressurization differs for pulse wave measurement and blood pressure measurement, and can be set individually for each. The operation of the lower limb measurement control unit 32 during pulse wave measurement and blood pressure measurement is the same as that of the upper limb measurement control unit 31, so a detailed explanation is omitted here.

[0021] The computers of the upper limb measurement control unit 101 and the lower limb measurement control unit 32 execute control programs stored in ROM using the CPU to perform calculations for blood pressure and pulse wave measurement, as described below.

[0022] In this embodiment, the blood pressure pulse wave measurement unit 30 is provided with an upper limb measurement control unit 31 and a lower limb measurement control unit 32, but the upper limb measurement control unit 31 and the lower limb measurement control unit 32 may be integrated into a single unit.

[0023] A heart sound microphone 23 is connected to the heart sound measurement unit 40. Limb electrocardiogram electrodes 24a and chest electrocardiogram electrodes 24b are connected to the electrocardiogram measurement unit 50. Amorphous pulse wave sensors 25a and 25b are connected to the pulse wave measurement unit 60.

[0024] The arithmetic processing unit 10 is a computer that includes a CPU, ROM, RAM, various interfaces, etc. The arithmetic processing unit 10 executes the control program stored in the ROM using the CPU.

[0025] The calculation processing unit 10 controls the blood pressure pulse wave measurement unit 30, the heart sound measurement unit 40, the electrocardiogram measurement unit 50, and the pulse wave measurement unit 60 (hereinafter referred to as "each biological information measurement unit").

[0026] Furthermore, the arithmetic processing unit 10 receives biological information supplied from each biological information measurement unit. When it is necessary to display the received biological information on the screen, it edits or converts it into display data and outputs it to the display unit 80. When it is necessary to print the information on report paper, it edits or converts it into print data and outputs it to the print unit 91. The arithmetic processing unit 10 also stores the received biological information in the storage unit 92 as appropriate, and reads the stored biological information.

[0027] Furthermore, the arithmetic processing unit 10 performs waveform analysis of the biological information received from each biological information measurement unit. In the waveform analysis, it detects characteristic parts (section points) in the waveform. Examples of characteristic parts include the start of the second heart sound, the rising part of the pulse wave in the upper arm, the rising part of the pulse wave in the ankle, the pulse wave notch, the pulse wave notch in the upper arm, and so on.

[0028] The calculation processing unit 10 calculates the degree of arteriosclerosis based on the analysis results and the numerical values ​​(e.g., blood pressure) indicated by the received biological information.

[0029] Let me explain in detail. The calculation processing unit 10 calculates the brachial-ankle pulse wave velocity (baPWV) and the heart-ankle artery pulse wave velocity (haPWV) as pulse wave velocity, and also calculates the ankle-brachial pressure index (ABI) as the lower limb-upper limb blood pressure ratio. In other words, the calculation processing unit 10 calculates the ankle-brachial pressure ratio (ABI) and pulse wave velocity (PWV) using the pulse wave detected by the blood pressure pulse wave measurement unit 30. The calculation processing unit 10 also calculates the subject's blood pressure value using the pulse wave detected by the blood pressure pulse wave measurement unit 30. Furthermore, the calculation processing unit 10 also calculates indices such as the cardio-ankle vascular index (CAVI), which is calculated based on the heart-ankle artery pulse wave velocity (haPWV). Here, the calculation control unit 10 calculates CAVI by correcting the cardiac-ankle arterial pulse wave velocity haPWV with a logarithmic pulse wave. As is well known, the brachial-ankle pulse wave velocity baPWV and the cardiac-ankle arterial pulse wave velocity haPWV are indicators of vascular stiffness, and the ankle-brachial index (ABI) is an indicator of vascular blockage.

[0030] Furthermore, the arithmetic processing unit 10 receives input and instructions from the user via the input unit 70, and, according to the received content, sets the functions related to each of the biometric information measurement units, display unit 80, printing unit 91, storage unit 92, and audio output unit 93, and controls the start and stop of their respective operations.

[0031] The display unit 80 is a display device having a display screen such as an LCD (Liquid Crystal Display), and displays biological information, analysis results, and arteriosclerosis degree, etc., input as display data from the arithmetic processing unit 10 on the screen.

[0032] The printing unit 91 mainly consists of a paper feeding mechanism and a print head, and prints biological information, analysis results, and arteriosclerosis degree, which are input as print data from the calculation processing unit 10, onto the paper.

[0033] The memory unit 92 is composed of a hard disk drive, a writable optical disk drive, non-volatile memory, etc., and is capable of storing information from the arithmetic processing unit 10. In addition, the memory unit 92 records biological information measured by each biological information measurement unit, namely electrocardiograms, pulse waves, and heart sounds.

[0034] The audio output unit 93 mainly consists of a speaker and outputs guidance voice or notification sound according to guidance data or notification sound output instruction signals input from the arithmetic processing unit 10.

[0035] The input unit 70 consists of a keyboard, mouse, buttons, touch panel, etc., and receives input and instructions from the user and sends them to the arithmetic processing unit 10.

[0036] The pulse wave measurement unit 60 supplies the pulse wave signals of the subject detected by amorphous pulse wave sensors 25a and 25b, which are appropriately attached to the subject, to the calculation processing unit 10. This allows for the measurement and analysis of the pulse wave. One of the amorphous pulse wave sensors 25a and 25b is attached, for example, to the subject's carotid artery, and the other is attached, for example, to the subject's femoral artery or knee.

[0037] The electrocardiogram measurement unit 50 supplies the electrocardiogram signals detected by the limb electrocardiogram electrode units 24a and the chest electrocardiogram electrode unit 24b attached to the subject to the calculation processing unit 10. This allows for the measurement and analysis of the electrocardiogram. The limb electrocardiogram electrode unit 24a typically consists of four electrocardiogram electrodes attached to the right wrist, left wrist, right ankle, and left ankle, respectively. Regarding the electrocardiogram electrodes for both ankles, it is preferable that they are designed so that attachment to both ankles is not hindered by the right ankle cuff 22R and the left ankle cuff 22L. The chest electrocardiogram electrode unit 25b typically consists of six electrocardiogram electrodes attached to six locations on the chest, respectively.

[0038] The heart sound measurement unit 40 supplies the heart sound signal detected by the heart sound microphone 23 attached to the subject to the processing unit 10. This enables the measurement and analysis of heart sounds.

[0039] <2> Main component configuration of this embodiment Figure 2 is a block diagram showing the main components of the blood pressure pulse wave analyzer according to this embodiment. In this embodiment, the components shown in Figure 2 are provided in the arithmetic processing unit 10. As described above, the arithmetic processing unit 10 is a computer having a CPU, ROM, RAM, various interfaces, etc. The arithmetic processing unit 10 realizes each of the functions shown in Figure 2 by executing a control program stored in ROM using the CPU.

[0040] The heart rate analysis unit 101 detects the subject's resting state by analyzing the subject's heart rate trend. Specifically, the heart rate analysis unit 101 receives the electrocardiogram obtained from the electrocardiogram measurement unit 50 as input to obtain heart rate information, and determines that the subject is in a resting state when the heart rate is below a predetermined heart rate and the change in heart rate is below a predetermined threshold. The heart rate analysis unit 101 outputs information indicating that the subject is in a resting state to the extraction unit 102.

[0041] The extraction unit 102 receives the blood pressure pulse wave measured by the blood pressure pulse wave measurement unit 30, extracts the blood pressure pulse wave from the measured blood pressure pulse wave when a resting state is detected by the heart rate analysis unit 102, and outputs it to the arteriosclerosis degree calculation unit 103.

[0042] The arteriosclerosis degree calculation unit 103 uses the blood pressure pulse wave input from the extraction unit 102 to calculate arteriosclerosis indicators such as CAVI and PWV. The method for calculating CAVI and PWV is a known technique described in Patent Documents 1 and 2, etc., so an explanation is omitted here.

[0043] As a result, the blood pressure pulse wave analyzer 1 of this embodiment detects the subject's resting state based on the subject's heart rate trend and calculates an index of arteriosclerosis using the blood pressure pulse wave under resting conditions. This allows for the calculation of an index of arteriosclerosis under normal conditions, rather than special conditions where vascular smooth muscle is contracted due to tension or other factors. Consequently, a decrease in the reliability of arteriosclerosis testing can be suppressed.

[0044] In this embodiment, the heart rate trend obtained by the heart rate analysis unit 101 is displayed on the display unit 80 via the display control unit 81.

[0045] Figure 3A shows an example of blood pressure pulse wave display according to this embodiment. The real-time blood pressure pulse wave waveform and heart rate trend (HR trend) are displayed on the same screen. Figure 3B is a magnified view of the heart rate trend (HR trend). Medical professionals such as doctors can determine whether the currently measured blood pressure pulse wave is from a resting or non-resting state by looking at the heart rate trend.

[0046] In this embodiment, the blood pressure pulse wave at rest is automatically extracted and the degree of arteriosclerosis at rest is calculated using the configuration shown in Figure 2. However, a healthcare professional may manually select the timing for calculating the degree of arteriosclerosis based on the heart rate trend as shown in Figure 3. For example, the blood pressure pulse wave analyzer 1 may be provided with a button to start calculating the degree of arteriosclerosis, and a healthcare professional may manually press the start button when they determine, based on the heart rate trend, that the subject is in a resting state.

[0047] Figure 4 shows the workflow for measuring blood pressure pulse waves (hereinafter sometimes simply referred to as pulse waves) in the blood pressure pulse wave measurement device 1.

[0048] First, in step F11, electrocardiogram electrodes are attached to the patient. From this point on, an electrocardiogram, i.e., heart rate, can be acquired. In step F12, when the user presses the start button, inflation of cuffs 21R, 21L, 22R, and 22L begins simultaneously (step F13). In step F14, cuff inflation ends and the pressure is maintained.

[0049] In step F15, pulse wave measurement begins after waiting for the pulse wave to stabilize. Here, pulse wave stabilization means, for example, that the fluctuation of the pulse wave baseline falls below a predetermined value.

[0050] In steps F16-1 to F16-3, an appropriate pulse wave is searched for based on the heart rate trend described above. Eventually, in step F17, when an appropriate pulse wave measurement range is found (i.e., when the heart rate analysis unit 102 determines that it is a resting heart rate), in step F18 the pulse wave within that measurement range is extracted and stored, and cuff deflation begins. When cuff deflation ends in step F19, blood pressure pulse wave measurement is completed.

[0051] <3> summary As described above, according to this embodiment, a blood pressure pulse wave measurement device 1 can be realized that can suppress the decrease in reliability of arteriosclerosis tests caused by the subject's tension, etc., by providing a blood pressure pulse wave measurement unit 30 for measuring the subject's blood pressure pulse wave, a heart rate analysis unit 101 for detecting the subject's resting state by analyzing the subject's heart rate trend, an extraction unit 102 for extracting the blood pressure pulse wave from the blood pressure pulse wave measurement unit 30 when the heart rate analysis unit 101 detects the subject's resting state, and an arteriosclerosis degree calculation unit 103 for calculating an index of the subject's arteriosclerosis using the blood pressure pulse wave extracted by the extraction unit 102.

[0052] The embodiments described above are merely examples of how the present invention can be implemented, and the technical scope of the present invention should not be limited by them. In other words, the present invention can be implemented in various ways without departing from its gist or its main features.

[0053] In the above-described embodiment, the heart rate analysis unit 101 detected fluctuations in heart rate based on the electrocardiogram, but it may also detect fluctuations in heart rate based on, for example, pulse waves or heart sounds to analyze whether the person is at rest or not. [Industrial applicability]

[0054] The present invention is widely applicable to blood pressure pulse wave analysis devices and blood pressure pulse wave analysis methods for calculating the degree of arteriosclerosis based on blood pressure pulse waves. [Explanation of Symbols]

[0055] 1. Blood pressure and pulse wave analyzer 10. Arithmetic Processing Unit 21R, 21L, 22R, 22L Cuff 30 Blood pressure and pulse wave measurement unit 50 Electrocardiogram Measurement Unit 101 Heart Rate Analysis Unit 102 Extraction part 103 Arteriosclerosis degree calculation section

Claims

1. A blood pressure pulse wave measurement unit that measures the blood pressure pulse wave of the subject, The heart rate analysis unit detects the subject's resting state by analyzing the subject's heart rate trend, An extraction unit that extracts the blood pressure pulse wave from the blood pressure pulse wave measured by the blood pressure pulse wave measurement unit when the heart rate analysis unit detects the subject's resting state, An arteriosclerosis degree calculation unit calculates an index of arteriosclerosis in the subject using the blood pressure pulse wave extracted by the extraction unit, Equipped with, The heart rate analysis unit detects that the subject is in a resting state when the subject's heart rate is below a predetermined heart rate and the change in the heart rate falls below a predetermined threshold. Blood pressure and pulse wave analyzer.

2. The system further includes a display unit that displays the heart rate trend graph on the same screen as the blood pressure pulse wave measured by the blood pressure pulse wave measurement unit. The blood pressure pulse wave testing device according to claim 1.

3. The steps include measuring the blood pressure and pulse wave of the subject, The procedure involves analyzing the subject's heart rate trend to detect the subject's resting state, and The steps include: extracting the blood pressure pulse wave from the measured blood pressure pulse wave when the subject is in a resting state; The steps include: calculating an index of arteriosclerosis in the subject using the extracted blood pressure pulse wave; Includes, In the step of detecting the resting state of the subject, the subject is detected to be in a resting state when the subject's heart rate is below a predetermined heart rate and the change in the heart rate falls below a predetermined threshold. Blood pressure and pulse wave analysis method.