WO2020246258A1 - Blood pressure measurement device, blood pressure measurement system, blood pressure measurement method, and blood pressure measurement program - Google Patents

Abstract

A blood pressure measurement device that comprises at least one processor. The processor acquires a received light signal that is detected on the basis of laser light that has been radiated into the body of measurement subject, performs a computation that is based on a laser Doppler method on the acquired received light signal to calculate a blood flow speed, calculates a blood flow acceleration on the basis of the calculated blood flow speed, and derives a blood pressure index value on the basis of the calculated blood flow acceleration.

Description

Blood pressure measuring device, blood pressure measuring system, blood pressure measuring method, and blood pressure measuring program

The present disclosure relates to a blood pressure measuring device, a blood pressure measuring system, a blood pressure measuring method, and a blood pressure measuring program.

As one of the blood pressure measuring devices, a portable small blood pressure measuring device has been proposed for the purpose of not only using it in a medical institution but also at home (see Japanese Patent Application Laid-Open No. 2016-112277).

The device described in Japanese Patent Application Laid-Open No. 2016-112277 irradiates the body with laser light, receives the laser light reflected or transmitted in the body, calculates the blood pressure and vascular resistance based on the received signal, and calculates the blood. Blood pressure is calculated based on flow rate and vascular resistance. Here, the blood flow rate is calculated by performing an operation based on the laser Doppler method on the received signal. As for the vascular resistance, the waveform of the volumetric pulse wave is read from the received signal, and the vascular resistance is calculated based on the ratio of the amplitudes of the ejection wave and the reflected wave in the volume pulse wave.

Blood pressure is said to be related to cerebral heart disease and dementia, and controlling blood pressure is important for extending healthy life expectancy. In addition, it has been reported that blood pressure is not constant and fluctuates within the day, and the risk of disease can be estimated by confirming the state of the fluctuation.

However, with the method of the blood pressure measuring device described in Japanese Patent Application Laid-Open No. 2016-112277, it may be difficult to accurately measure the state of blood pressure fluctuation. This is because, in Japanese Patent Application Laid-Open No. 2016-112277, it is necessary to detect the amplitudes of the ejection wave and the reflected wave included in the volume pulse wave from the received signal in order to obtain the vascular resistance. However, when the received signal has a large amount of high-frequency noise, it becomes difficult to accurately measure the amplitudes of the ejection wave and the reflected wave in the volume pulse wave. In that case, the vascular resistance cannot be calculated accurately. In the method described in JP-A-2016-112277, blood pressure is measured by utilizing vascular resistance. Therefore, if the vascular resistance is not accurate, there is a concern about the accuracy of blood pressure measurement. Therefore, there is a risk that the state of blood pressure fluctuation cannot be confirmed accurately.

In view of the above problems, it is an object of the present disclosure to provide a blood pressure measuring device, a blood pressure measuring system, a blood pressure measuring method, and a blood pressure measuring program capable of accurately confirming the state of blood pressure fluctuation.

The blood pressure measuring device according to one aspect of the present disclosure includes at least one processor, and the processor acquires a received light signal detected based on the laser beam emitted into the body of the person to be measured, and uses the acquired light receiving signal as the received light signal. On the other hand, the blood flow velocity is calculated by performing a calculation based on the laser Doppler method, the blood flow acceleration is calculated based on the calculated blood flow velocity, and the blood pressure index value is derived based on the calculated blood flow acceleration.

In the blood pressure measuring device of the above aspect, the processor may derive a blood pressure index value based on the correlation between the blood flow acceleration and the blood pressure.

Further, in the blood pressure measuring device of the above aspect, the processor may calculate the heart rate based on the time change of the received signal and derive the blood pressure index value based on the calculated blood flow acceleration and the heart rate.

Further, in the blood pressure measuring device of the above aspect, the processor may derive a blood pressure index value based on the correlation between blood flow acceleration and blood pressure and the correlation between heart rate and blood pressure.

Further, in the blood pressure measuring device of the above aspect, the processor further detects the behavioral state of the person to be measured, and the processor calculates the blood pressure index value based on the behavioral state of the person to be measured, the blood flow acceleration, and the heart rate. It may be derived.

Further, in the blood pressure measuring device of the above aspect, when the processor sets the blood pressure index value as BFV, the heart rate as HR, and the blood flow acceleration as diff,
BFV = HR x diff ... (1)
The blood pressure index value may be calculated using the equation (1) represented by.

Further, the blood pressure measuring device of the above embodiment, the processor is further adapted to detect the action status of the subject, the processor, a constant for adjusting the weights of the heart rate HR a _1, adjust the weighting of blood flow acceleration diff When the constant to be measured is b ₁ , the constant a ₁ and the constant b ₁ are determined based on the behavioral state of the person to be measured.
BFV = HR x diff x (a ₁ x HR + b ₁ x diff) / (HR + diff) ... (2)
The blood pressure index value may be calculated using the equation (2) represented by.

Further, in the blood pressure measuring device of the above aspect, the processor may calculate the blood pressure at the time of measurement based on the reference blood pressure of the subject to be measured and the blood pressure index value acquired in advance.

Further, the blood pressure measuring device of the above aspect, the processor, BP blood pressure at the time of measurement, BFV blood pressure index value, a constant determined based on at least one calculation method and measurement conditions of the blood pressure index value a _{2 ,} if a constant determined based on the reference blood pressure was b _2,
BP = a ₂ x BFV + b ₂ ... (3)
The blood pressure at the time of measurement may be calculated using the equation (3) represented by.

Further, the blood pressure measuring device of the above aspect may include an output unit that outputs information based on the blood pressure index value derived by the processor.

Further, in the blood pressure measuring device of the above aspect, the output unit outputs at least one of a real-time measured value of the blood pressure index value, a diurnal variation of the blood pressure index value, and a comparison of the blood pressure index value with a past measured value. You may.

Further, in the blood pressure measuring device of the above aspect, the processor calculates the blood pressure at the time of measurement based on the reference blood pressure of the subject to be measured and the blood pressure index value acquired in advance, and the output unit is the blood pressure. At least one of real-time measurements of blood pressure, diurnal variation in blood pressure, and comparison with past measurements of blood pressure may be output.

Further, in the blood pressure measuring device of the above aspect, the output unit may output information indicating an abnormality when the blood pressure index value derived by the processor exceeds a predetermined threshold value.

Further, in the blood pressure measuring device of the above aspect, an irradiation unit that irradiates the body of the person to be measured with a laser beam, a light receiving unit that receives the laser light reflected or transmitted inside the body, a processor, and an output unit are integrally held. However, it may be provided with a housing that can be carried by the person to be measured.

Further, in the blood pressure measuring device of the above aspect, the output unit may be a display.

The blood flow measurement system according to one aspect of the present disclosure acquires a light-receiving signal detected based on the laser beam radiated into the body of the person to be measured, and performs a calculation based on the laser Doppler method on the acquired light-receiving signal. A blood pressure measuring device main body provided with at least one processor that calculates the blood flow velocity, calculates the blood flow acceleration based on the calculated blood flow velocity, and derives the blood pressure index value based on the calculated blood flow acceleration. It includes an irradiation unit that irradiates the body of the person to be measured with a laser beam, and a light receiving signal detection unit including a light receiving unit that receives the laser light reflected or transmitted inside the body.

In the blood flow measuring method according to one aspect of the present disclosure, a light receiving signal detected based on the laser beam radiated into the body of the person to be measured is acquired, and the acquired light receiving signal is calculated based on the laser Doppler method. The blood flow velocity is calculated, the blood flow acceleration is calculated based on the calculated blood flow velocity, and the blood pressure index value is derived based on the calculated blood flow acceleration.

The blood pressure measurement program according to one aspect of the present disclosure includes a procedure for acquiring a received light signal detected based on the laser beam radiated into the body of the subject, and an operation based on the laser Doppler method for the acquired received signal. To have the computer execute the procedure of calculating the blood flow velocity, the procedure of calculating the blood flow acceleration based on the calculated blood flow velocity, and the procedure of deriving the blood pressure index value based on the calculated blood flow acceleration. ..

According to the present disclosure, it is possible to provide a blood pressure measuring device, a blood pressure measuring system, a blood pressure measuring method, and a blood pressure measuring program that can accurately confirm the state of blood pressure fluctuation.

External view of the blood pressure measuring device according to the first embodiment External view of the back surface of the main body case of the blood pressure measuring device according to the first embodiment. Functional configuration diagram of the blood pressure measuring device according to the first embodiment Graph showing the relationship between blood flow acceleration and blood pressure Graph showing the relationship between heart rate and blood pressure Flow chart explaining the flow of blood flow acceleration calculation Diagram explaining the propagation of laser light in the body Graph showing the time course of the received signal A graph showing an enlarged state of the waveform shown in FIG. Graph showing the beat signal included in the received signal Graph showing the power spectrum of the beat signal included in the received signal A flowchart illustrating a flow of blood pressure measurement processing according to the first embodiment. The figure which shows the display example of the measurement result in the display part The figure which shows the display example of the measurement result in the display part Functional configuration diagram of the blood pressure measuring device according to the second embodiment A flowchart illustrating a flow of blood pressure measurement processing in the second embodiment. A flowchart illustrating a flow of blood pressure measurement processing in the third embodiment. External view of the blood pressure measurement system according to the fourth embodiment

[First Embodiment]
Hereinafter, the first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an external view of the blood pressure measuring device 10 according to the first embodiment, and FIG. 2 is an external view of the back surface of the main body case 11 of the blood pressure measuring device 10. The blood pressure measuring device 10 irradiates the body of the person to be measured with a laser beam, receives the laser light reflected or transmitted in the body, and measures information on the blood pressure of the person to be measured based on the received signal. In this example, the blood pressure measuring device 10 is a wristwatch-type device that can be worn on the wrist and carried like a wristwatch.

As shown in FIGS. 1 and 2, the blood pressure measuring device 10 includes a main body case 11 which is a housing, and a fixing band 12 for attaching and fixing the main body case 11 to a measuring portion such as an arm of a person to be measured. ..

A touch panel display 13, an operation switch 14, a speaker 15, and the like are provided on the surface of the main body case 11 (that is, the surface that faces outward when worn by the person to be measured). As is well known, the touch panel display 13 is a device that combines a display device such as an LCD (Liquid Crystal Display) and a position detection device that detects the contact position of a hand on the screen. Using the touch panel display 13 and the operation switch 14, the person to be measured inputs a measurement start instruction or the like. Further, the touch panel display 13 displays an operation screen, measurement results, and the like. Further, the speaker 15 outputs voice guidance related to the measurement, a notification sound of the measurement result, and the like.

Further, when the main body case 11 is attached to the arm by the fixing band 12, the back surface of the main body case 11 comes into contact with the skin surface of the person to be measured. An irradiation unit 16 (see FIG. 3) and a light receiving unit 17 (see FIG. 3) are provided in the main body case 11, and an irradiation window 16A of the irradiation unit 16 and a light receiving unit 17 are provided on the back surface of the main body case 11. The light receiving window 17A of 17 is arranged.

The irradiation unit 16 has a light source that irradiates the person to be measured with the measurement light. The light source is, for example, a laser light source that irradiates a single wavelength laser light as measurement light. As the laser light source, for example, a laser light source such as VCSEL (Vertical Cavity Surface Emitting Laser) is used. In the present embodiment, since the laser light is emitted toward the inside of the body, the wavelength of the laser light is preferably a wavelength in the near-infrared light band having skin transparency.

The light receiving unit 17 receives a light receiving element that receives the laser light reflected or transmitted in the body and outputs a light receiving signal that is an electric signal according to the amount of light received, and receives the light receiving signal by converting the light receiving signal from an analog signal to a digital signal. It is equipped with an A / D (Analog / Digital) converter that outputs digital data of signals. As the light receiving element, for example, a photodiode is used. Instead of the photodiode, an element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) may be used.

Further, as the blood vessel for which the blood pressure is to be measured, for example, the radial artery of the wrist of the person to be measured is preferable. Since the blood pressure measuring device 10 is a wristwatch type, when the blood pressure measuring device 10 is attached to the wrist, the irradiation window 16A and the light receiving window 17A are arranged at positions corresponding to the radial artery of the wrist, which is a blood vessel to be measured. .. The laser beam emitted from the irradiation unit 16 enters the body from the skin surface of the subject and is diffusely reflected, and a part of the laser light reaches the light receiving unit 17.

FIG. 3 is a functional configuration diagram of the blood pressure measuring device 10. The blood pressure measuring device 10 includes an irradiation unit 16, a light receiving unit 17, an operation unit 110, a display unit 120, a sound output unit 130, a communication unit 140, a storage unit 150, a power supply unit 160, and a processing unit 200. And. Each of these parts is provided in the main body case 11 shown in FIG.

The operation unit 110 is an operation input device that inputs an operation signal corresponding to the operation to the processing unit 200. Various instructions such as a blood pressure measurement start instruction are input by the operation unit 110. The operation switch 14 and the touch panel display 13 of FIG. 1 correspond to the operation unit 110.

The display unit 120 performs various displays based on the display signal from the processing unit 200. The measurement result and the like are displayed on the display unit 120. The touch panel display 13 of FIG. 1 corresponds to the display unit 120.

The sound output unit 130 is, for example, a speaker, and outputs sound based on an instruction from the processing unit 200. The sound output unit 130 outputs a notification sound such as the start and end of blood pressure measurement and / or a guidance voice. The speaker 15 in FIG. 1 corresponds to the sound output unit 130.

Note that at least one of the display unit 120 and the sound output unit 130 is an example of an output unit within the scope of claims.

The communication unit 140 realizes communication with an external device. The communication unit 140 includes at least one of a wired communication unit and a wireless communication unit. The wired communication unit includes, for example, a wired communication module composed of an electric circuit for performing wired communication and a jack for connecting a wired cable. The wireless communication unit includes, for example, a wireless communication module composed of an electric circuit for performing wireless communication and an antenna for transmitting and receiving radio waves.

The storage unit 150 is a storage medium such as a RAM (RandomAccessMemory), a ROM (ReadOnlyMemory), and / or a flash memory. The storage unit 150 stores a program, data, and the like for the processing unit 200 to integrally control the blood pressure measuring device 10. Further, the storage unit 150 stores the calculation result executed by the processing unit 200.

The power supply unit 160 is, for example, a rechargeable battery, and supplies electric power to each unit of the blood pressure measuring device 10. As a charging method for the battery, for example, a charging connector is provided in the main body case 11, and the charging connector and the charger are wiredly connected by a cable or the like. Of course, instead of the wired method, a wireless charging method using electromagnetic induction or the like may be used.

The processing unit 200 is realized by, for example, an electronic component such as a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), and / or a main memory. The processing unit 200 executes various arithmetic processes related to blood pressure measurement based on a predetermined program such as a blood pressure measurement program and data necessary for executing the program. Further, the processing unit 200 controls the operation of each unit of the blood pressure measuring device 10 based on an operation signal or the like from the operation unit 110.

The main memory is a storage medium that can store programs, program data, etc., and CPU calculation values, and is realized by RAM, ROM, and / or flash memory, etc.

Further, the processing unit 200 has an acquisition unit 201 and a calculation unit 202. The acquisition unit 201 acquires the received light signal output from the light receiving unit 17. The acquisition unit 201 acquires the received light signal after being converted into digital data. The calculation unit 202 derives a blood pressure index value based on the light receiving signal of the light receiving unit 17. In this example, the calculation unit 202 performs a calculation based on the calculation formula to calculate the blood pressure index value.

Hereinafter, the details of the processing executed by the calculation unit 202 will be described.
[principle]
(A) Method of calculating blood pressure index value based on blood flow acceleration and heart rate FIG. 4 is a graph showing the relationship between blood flow acceleration and blood pressure, and the horizontal axis is blood flow acceleration (unit: cm / s ^2). ), The vertical axis shows blood pressure (unit: mmHg). As shown in the graph of FIG. 4, there is a correlation between blood flow acceleration and blood pressure. Further, FIG. 5 is a graph showing the relationship between the heart rate and the blood pressure, and the horizontal axis shows the heart rate (unit: bpm (beats per minute)) and the vertical axis shows the blood pressure (unit: mmHg). As shown in the graph of FIG. 5, there is a correlation between heart rate and blood pressure. The inventor has found that a blood pressure index value can be derived based on the blood flow acceleration and the heart rate by using the correlation between the blood flow acceleration and the blood pressure and the correlation between the heart rate and the blood pressure.

In the present disclosure, the blood pressure index value means an index value indicating how much the blood pressure has changed from the reference state with reference to the blood pressure in the specific state of the person to be measured. Although this blood pressure index value does not indicate the actual blood pressure value, it is possible to confirm the state of blood pressure fluctuation by acquiring the blood pressure index value over time.

The blood pressure in a specific state of the subject to be measured as a reference may be any state of blood pressure. Further, the blood pressure includes systolic blood pressure (for example, systolic blood pressure) and diastolic blood pressure (for example, diastolic blood pressure), and either blood pressure may be used. Here, a case will be described in which a blood pressure index value for systolic blood pressure (for example, systolic blood pressure) is derived based on the resting systolic blood pressure (for example, systolic blood pressure) of the subject.

As a method of deriving the blood pressure index value based on the blood flow acceleration and the heart rate, specifically, the blood pressure index value is BFV (unit: none), the heart rate is HR (unit: bpm), and the blood flow acceleration is diff (diff). When the unit is: cm / s ² ), the blood pressure index value BFV is calculated using the formula (A).
BFV = HR x diff ... (A)

(A-1) Method of calculating blood flow acceleration First, a method of calculating blood flow acceleration will be described. FIG. 6 is a flowchart illustrating the flow of blood flow acceleration calculation. Further, FIG. 7 is a diagram for explaining the propagation of the laser beam in the body, and shows a cross section of the subject to be measured along the depth direction in the body. Hereinafter, the calculation of the blood flow acceleration based on the laser Doppler method will be described in detail with reference to FIG.

In the calculation of the blood flow acceleration, first, the light receiving signal acquired by the light receiving unit 17 is calculated based on the laser Doppler method, and the power spectrum representing the distribution state of the blood flow velocity of the plurality of blood vessels 21 in FIG. Is calculated (step S1). The power spectrum will be described later.

FIG. 8 is a graph showing the time course of the received signal. Blood vessels repeatedly expand and contract according to the heartbeat cycle. The amount of laser light absorbed by the blood vessels is large when the blood vessels are dilated and small when the blood vessels are contracted. Therefore, the amount of reflected light from the laser light (and the received signal indicating the amount of reflected light) depends on the heartbeat cycle. Repeat the increase and decrease. The change with time of the received light signal shown in FIG. 8 represents an increase or decrease of the received light signal according to the heartbeat cycle. FIG. 9 is an enlarged graph of a part of the waveform shown in FIG. 8 (specifically, the waveform for one heartbeat). FIG. 10 is a graph showing a beat signal included in the received light signal, and FIG. 11 is a graph showing a power spectrum of the beat signal included in the received signal. The beat signal will be described later.

When a moving object is irradiated with light, the Doppler effect occurs in which the frequency of scattered scattered light changes due to the reflection of light on the object according to the moving speed of the object. Since the hemoglobin 22 moves in the blood vessel 21 as shown in FIG. 7, the scattered light scattered by the hemoglobin 22 causes a Doppler shift which is a frequency change according to the movement speed (that is, the blood flow speed) of the hemoglobin 22. .. Since the frequencies of the laser light are the same, the difference between the frequency of the irradiated laser light and the frequency of the scattered light that has caused the Doppler shift is information that mainly reflects the moving speed of the hemoglobin 22. Therefore, it is possible to detect the blood flow velocity by using the laser light as the measurement light. The laser Doppler method is a method for calculating the blood flow velocity on the premise of such a Doppler shift of laser light. The calculation unit 202 calculates the blood flow velocity by performing a calculation based on the laser Doppler method.

More specifically, as shown in FIG. 7, when the laser beam is irradiated into the body from the skin surface 20, when the laser beam is scattered by the hemoglobin 22 moving in the blood vessel 21, a Doppler shift occurs. On the other hand, the laser light does not cause Doppler shift even if it is scattered by a stationary tissue other than the blood vessel 21 such as skin. Assuming that the frequency of the irradiated laser light is ω0 and the frequency change caused by the moving speed of the hemoglobin 22 is the difference frequency Δω, the frequency of the scattered light scattered by the hemoglobin 22 is ω0 + Δω.

That is, when a laser beam having a frequency of ω0 is irradiated into the body, it is scattered by a stationary tissue and scattered by a laser beam that maintains the frequency ω0 without Doppler shift and a hemoglobin 22 that moves in the blood vessel 21. , Light interference occurs due to the laser light whose frequency is ω0 + Δω due to the Doppler shift. Due to this light interference, a beat signal having a difference frequency Δω is generated, and the beat signal is superimposed on the received signal. That is, as shown in the graphs of FIGS. 8 and 9, the received signal includes a volume pulse wave component corresponding to a pulse change of a blood vessel accompanying blood ejection from the heart, and a beat signal component.

The frequency of the volume pulse wave in the received signal is several tens of Hz or less, and the frequency of the beat signal in the received signal is about several hundred Hz to several tens of kHz. In addition, high-frequency noise having a frequency higher than that of the beat signal may be superimposed on the received signal. The frequency of the volume pulse wave, the frequency of the beat signal, and the frequency of the high frequency noise in the received signal are all different. Therefore, the calculation unit 202 executes, for example, a filtering process and separates only the beat signal as shown in the graph of FIG.

The calculation unit 202 performs frequency analysis such as FFT (Fast Fourier Transform) analysis on the beat signal at regular sampling periods (for example, about 10 seconds to 1 minute), so that the beat signal in each sampling period is performed. Calculate the power spectrum of. Since the laser beam irradiates a plurality of blood vessels 21, if the blood flow velocity is different for each blood vessel 21, the beat signal includes a plurality of frequency components reflecting the blood flow velocity of each blood vessel 21. The power spectrum of the beat signal represents the distribution state of the blood flow velocity of the plurality of blood vessels 21. FIG. 11 is an example of the power spectrum of the beat signal.

As shown in FIG. 6, in step S1, when a certain sampling period elapses, the calculation unit 202 calculates a power spectrum based on the beat signal acquired during the sampling period. Then, in step S2, the blood flow velocity is calculated based on the calculated power spectrum.

The calculation unit 202 obtains the average value of the blood flow velocities of the plurality of blood vessels 21 by calculating the frequency average value of the power spectrum, and calculates this average value as the blood flow velocity. Here, a method of calculating the blood flow velocity will be described. The frequency mean value ω _ave of the power spectrum P (ω) is the area obtained by integrating the product of the product of the frequency ω and the power spectrum P (ω) at the frequency ω with respect to the frequency ω in the area of the signal region of the power spectrum P (ω). It is proportional to the divided value. The frequency mean value ω _ave of the power spectrum P (ω) is calculated by using the equation (B) as an example.
ω _ave = (∫ω × P (ω) dω) / (∫P (ω) dω)… (B)

In step S3, the calculation unit 202 saves the calculated blood flow velocity. Then, in step S4, the calculation unit 202 repeats steps S1, S2, and S3 to acquire the blood flow velocity for a preset period. As a result, the time course of blood flow velocity is acquired. Then, in step S5, the calculation unit 202 calculates the blood flow acceleration by differentiating the blood flow velocity.

(A-2) Method of calculating heart rate Next, a method of calculating heart rate will be described. The calculation unit 202 calculates the heart rate by, for example, counting the number of peaks of the received signal including the component of the volume pulse wave for one minute as shown in FIG. Here, the calculation unit 202 performs a filtering process for extracting only the frequency component of the volume pulse wave from the received signal, for example, removes the frequency component unnecessary for the measurement of the number of peaks, and then calculates the heart rate. ..

(B) Method of calculating blood pressure based on blood pressure index value At least one of blood pressure at the time of measurement is BP (unit: mmHg), blood pressure index value is BFV (unit: none), blood pressure index value calculation method and measurement conditions. When the constant determined based on is a _{2 and the} constant determined based on the reference blood pressure is b ₂ , the calculation is performed using the equation (C).
BP = a ₂ x BFV + b ₂ ... (C)

The constant a ₂ is a coefficient parameter for adjusting the calculated value according to the BFV calculation formula and the measurement conditions.

The constant b ₂ is a reference parameter corresponding to the reference blood pressure of the subject. As described above, the reference blood pressure is the blood pressure obtained in a specific state of the person to be measured, and may be the blood pressure in any state. As described above, in the present embodiment, one example is the resting systolic blood pressure (for example, systolic blood pressure) of the subject.

An example of a method for determining the constant b ₂ will be described. First, at rest of the subject, the blood pressure is measured by a general sphygmomanometer different from the blood pressure measuring device 10 of the present embodiment and the blood pressure is measured by the blood pressure measuring device 10 of the present embodiment at the same time. As a result, the resting systolic blood pressure (for example, systolic blood pressure) BP _s and the resting blood pressure index value BFV _s of the subject are acquired. The systolic blood pressure (for example, systolic blood pressure) BP _s is input to the blood pressure measuring device 10 by the person to be measured via the touch panel display 13 or the like. When it is difficult to measure blood pressure with a general sphygmomanometer, the subject inputs his / her expected blood pressure (for example, blood pressure measured in the past) as systolic blood pressure (for example, systolic blood pressure) BP _s. You may.

Substituting the systolic blood pressure BP _s and the blood pressure index value BFV _s in the equation (C) gives the equation (D). When the equation (D) is rearranged for the constant b ₂ , it becomes the same as the equation (E), and the constant b ₂ can be calculated. The method for determining the constant b ₂ is not limited to the above, and may be determined by another method.
BP _s = a ₂ x BFV _s + b ₂ ... (D)
b ₂ = BP _s ―a ₂ × BFV _s … (E)

(C) Specific example of calculation of blood pressure index value and blood pressure As an example, based on the resting systolic blood pressure (for example, systolic blood pressure) of the subject, the blood flow acceleration diff and heartbeat are used using the formula (A). A case where the blood pressure index value BFV is calculated based on the number HR will be described. For example, when the blood flow acceleration diff (unit: cm / s ² ) measured by the blood pressure measuring device 10 is 0.20 and the heart rate HR (unit: bpm) is 65.0, it is based on the equation (A). The blood pressure index value BFV (unit: none) is calculated as 13.0.
BFV = HR x diff ... (A)

Next, a case where the blood pressure BP at the time of measurement of the subject is calculated based on the blood pressure index value BFV will be described using the formula (C). Here, the constant a ₂ is determined to be 0.870 based on the BFV calculation formula and the measurement conditions, and the constant b ₂ is the pre-obtained systolic blood pressure of the subject (for example, systolic blood pressure). ) Is determined as 107.150 as the reference blood pressure. As described above, since the blood pressure index value BFV (unit: none) is calculated as 13.0, the blood pressure BP (unit: mmHg) is calculated as 118.46 based on the equation (C).
BP = a ₂ x BFV + b ₂ ... (C)

[Processing flow]
FIG. 12 is a flowchart illustrating a flow of blood pressure measurement processing. This process is realized by the processing unit 200 executing the process according to the program. When the blood pressure measuring device 10 is attached to the measurement site of the person to be measured and the person to be measured gives an instruction to start measurement, the blood pressure measuring process is started.

First, the processing unit 200 starts irradiating the measurement light by the irradiation unit 16 and acquires the light receiving signal of the light receiving unit 17 at that time (step S11).

Next, the calculation unit 202 executes the process of step S1 of FIG. 6 based on the beat signal superimposed on the received light signal, calculates the power spectrum of the beat signal, and stores it in the storage unit 150 (step S12). ).

Next, the calculation unit 202 calculates the blood flow acceleration based on the power spectrum of the beat signal and stores it in the storage unit 150 (step S13). Specifically, the calculation unit 202 executes the processes from step S2 to step S4 in FIG. 6 and acquires the change with time of the blood flow velocity for a preset period based on the power spectrum of the beat signal. .. Then, the blood flow acceleration is calculated by differentiating the blood flow velocity based on the acquired blood flow velocity change with time. The calculation unit 202 stores the calculated blood flow acceleration in the storage unit 150.

Next, the calculation unit 202 calculates the heart rate based on the received signal and stores it in the storage unit 150 (step S14).

Next, the calculation unit 202 calculates the blood pressure index value based on the blood flow acceleration and the heart rate and stores it in the storage unit 150 (step S15).

Next, the calculation unit 202 calculates the blood pressure based on the blood pressure index value and stores it in the storage unit 150 (step S16).

Next, the processing unit 200 displays the measurement result including the calculated blood pressure on the display unit 120 (step S17).

Here, a display example of the measurement result on the display unit 120 will be described. As a measurement result, the processing unit 200 displays four icons 31 to 34 shown in FIG. 13 according to, for example, a blood pressure value in addition to the blood pressure. The four icons 31 to 34 are characters that imitate the faces of animals, and the four icons 31 to 34 have different facial expressions. The facial expression corresponds to the blood pressure value, and one of the four icons 31 to 34 is selected according to the blood pressure value.

Specifically, both icon 31 and icon 32 have a smile, but icon 31 has a higher degree of smile. Icon 31 is selected when the blood pressure value is in a very good range. The icon 32 is selected when the degree of smile is lower than that of the icon 31 and the blood pressure value is in a slightly good range. The facial expression of the icon 34 is a crying face and is selected when the blood pressure value is out of the appropriate range. The icon 33 is a normal facial expression that is neither a smiling face nor a crying face, and is selected when the blood pressure value is not good, but is within an appropriate range.

Further, as the measurement result, the blood pressure index value may be displayed in addition to or in place of the blood pressure and the icons 31 to 34. FIG. 14 is a display example of the blood pressure index value on the display unit 120. As shown in FIG. 14, the magnitude of the blood pressure index value may be indicated by the meter display by the meter 40. In this case, the meter display color is, for example, green when the blood pressure index value is 0, that is, a region close to the reference blood pressure, and gradually changes to red as the blood pressure index value approaches outside the appropriate range.

In the present embodiment, one blood pressure measurement is completed by performing the processes from step S11 to step S17 in response to the measurement start instruction, but the blood pressure measurement is continuously performed until the measurement end instruction is given. You may do it. That is, after the blood pressure measurement process is completed, if the measurement end instruction is not given, the process may be shifted to step S11.

[Action effect]
The blood pressure measuring device 10 of the present embodiment includes an acquisition unit 201 and a calculation unit 202, and the calculation unit 202 calculates a blood flow velocity by performing a calculation based on the laser Doppler method, and the calculated blood flow velocity is calculated. Since the blood flow acceleration is calculated based on the above and the blood pressure index value is derived based on the calculated blood flow acceleration, the state of blood pressure fluctuation can be confirmed accurately.

That is, the method shown in Japanese Patent Application Laid-Open No. 2016-112277 calculates blood pressure by obtaining heartbeat and vascular resistance based on a received signal. As shown in FIG. 9, in the method of determining the vascular resistance, it is necessary to accurately measure the amplitude AP of the ejection wave and the amplitude AT of the reflected wave in the volume pulse wave from the received signal. However, when high frequency noise is superimposed on the received signal, it is difficult to accurately measure the amplitude AP and the amplitude AT.

On the other hand, according to the blood pressure measuring device 10 of the present embodiment, the blood pressure index value is derived based on the blood flow acceleration. Since this method does not require the process of obtaining the vascular resistance based on the amplitude AP and the amplitude AT, which are difficult to read due to high frequency noise, it is possible to derive an accurate blood pressure index value as compared with the conventional method. .. In this way, if an accurate blood pressure index value can be derived, the state of blood pressure fluctuation can be confirmed accurately.

Further, the blood pressure measuring device 10 of the present embodiment calculates the heart rate based on the time change of the received signal in addition to the blood flow acceleration, and derives the blood pressure index value based on the blood flow acceleration and the heart rate. Therefore, the blood pressure index value can be derived more accurately than in the case of deriving the blood pressure index value based only on the blood flow acceleration. As described above, the heart rate can be calculated by counting the number of peaks of the volume pulse wave of the received signal. Unlike reading the amplitude AP and the amplitude AT, it can be accurately executed even if high frequency noise is superimposed on the received signal as long as the number of peaks of the volume pulse wave is counted.

Further, the blood pressure measuring device 10 of the present embodiment integrally holds the irradiation unit 16, the light receiving unit 17, the calculation unit 202, and the display unit 120 and the sound output unit 130, which are output units, and is to be measured. It includes a main body case 11 which is a housing that can be carried by a person. Since it is portable, it is possible to easily continue the measurement. Therefore, since the blood pressure index value or the time change of blood pressure can be easily recorded, it is easy to record the diurnal variation of blood pressure.

Further, for the calculation of the blood pressure index value, the correlation between the blood flow acceleration and the blood pressure and the correlation between the heart rate and the blood pressure are used. As an example, the blood pressure index value is calculated using the formula (A) that reflects these correlations. In this way, the blood pressure index value can be accurately calculated by calculating the blood pressure index value by reflecting the actual phenomenon in the body.
BFV = HR x diff ... (A)

In addition, the blood pressure at the time of measurement can be calculated based on the blood pressure index value and the reference blood pressure of the subject to be measured, which is obtained in advance. As an example, the blood pressure is calculated using the formula (C). doing. At this time, since the blood pressure index value is an accurate value as described above, the blood pressure can also be calculated accurately.
BP = a ₂ x BFV + b ₂ ... (C)

Further, since the output unit that outputs the information based on the blood pressure index value calculated by the calculation unit 202 is provided, the information based on the blood pressure index value calculated by the calculation unit 202 can be output to the outside. Since the display unit 120 (corresponding to the touch panel display 13 in this example) is provided as the output unit, the blood pressure index value and / or the blood pressure measurement result can be displayed numerically on the display unit 120, or the measurement result can be displayed. Information based on the blood pressure index value can be visually transmitted to the subject by displaying an image or the like.

Further, since the sound output unit 130 (corresponding to the speaker 15 in this example) is provided as the output unit, the blood pressure index value and / or the numerical value of the blood pressure measurement result can be output by voice or according to the measurement result. Information based on the blood pressure index value can be audibly transmitted to the person to be measured by outputting a sound effect or the like.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. FIG. 15 is a functional configuration diagram of the blood pressure measuring device 10B according to the second embodiment. In the following, the differences from the first embodiment will be mainly described, and the description of the contents overlapping with the first embodiment will be omitted.

The difference between the blood pressure measuring device 10B of the second embodiment and the first embodiment is that the blood pressure measuring device 10B of the second embodiment detects the behavioral state of the person to be measured by the processing unit 200. The point is that the detection unit 203 is further provided. In addition, the calculation unit 202 calculates the blood pressure index value based on the behavioral state of the person to be measured, the blood flow acceleration, and the heart rate.

FIG. 16 is a flowchart illustrating a flow of blood pressure measurement processing in the second embodiment.

The processing from the acquisition of the received light signal (step S21) to the calculation / storage of the heart rate (step S24) is the same as that of the first embodiment.

Next, the detection unit 203 detects the behavioral state of the person to be measured and stores it in the storage unit 150 (step S25). Here, as the detection unit 203, for example, a sensor that detects body movement, such as an acceleration sensor, is used. The detection unit 203 is built in the main body case 11, and the detection unit 203 detects the behavioral state of the person to be measured.

Next, the calculation unit 202 calculates the blood pressure index value based on the behavioral state of the person to be measured, the blood flow acceleration, and the heart rate, and stores it in the storage unit 150 (step S26). Specifically, the blood pressure index value is BFV (unit: none), the heart rate is HR (unit: bpm), the blood flow acceleration is diff (unit: cm / s ² ), and the constant for adjusting the weighting of the heart rate HR is set. When a ₁ and the constant for adjusting the weighting of the blood flow acceleration diff are b ₁ , the blood pressure index value BFV is calculated using the equation (F).
BFV = HR x diff x (a ₁ x HR + b ₁ x diff) / (HR + diff) ... (F)

Regarding the constant a ₁ and the constant b ₁ , for example, at rest, both the constant a ₁ and the constant b ₁ are set to 1. Further, since the influence of the heart rate becomes large during strenuous exercise, for example, the constant a _{1 is set} to 1.5 and the constant b _{1 is set} to 0.5 during exercise. The above values for the constant a ₁ and the constant b ₁ are examples, and are not limited to these values. As for exercise, the load level and duration such exercise, for example, a light load, during a middle load, and, as a high load, further stepwise finely adjust the constants a ₁ and a constant b ₁ You may.

The processing from the calculation / storage of blood pressure (step S27) to the output of the measurement result (step S28) after step S26 is the same as that of the first embodiment.

According to the blood pressure measuring device 10B of the present embodiment, the blood pressure index value is calculated based on the behavioral state, blood flow acceleration, and heart rate of the person to be measured, and based only on the blood flow acceleration and heart rate. Compared with the case of calculating the blood pressure index value, the blood pressure index value can be calculated by reflecting the phenomenon in the body more. Therefore, according to the second embodiment, a more accurate blood pressure index value can be calculated in the sense that it reflects the behavioral state of the person to be measured.

As a method of detecting the behavioral state of the person to be measured, the calculation unit 202 may function as a detection unit instead of using the detection unit 203 such as an acceleration sensor. For example, in the calculation unit 202, the behavioral state of the person to be measured is determined by determining that the blood flow acceleration and / or heart rate values are less than a preset threshold value at rest and above the threshold value during exercise. Is detected. In this case, since the calculation unit 202 functions as a detection unit, it is not necessary to provide a detection unit 203 composed of an acceleration sensor or the like separately from the calculation unit 202, so that the number of parts can be reduced.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. Since the functional configuration of the blood pressure measuring device in the present embodiment is the same as that of the blood pressure measuring device 10 in the first embodiment, the description thereof will be omitted. The blood pressure measuring device of the present embodiment is different from the blood pressure measuring device 10 of the first embodiment in that a blood pressure index value is derived only based on the blood flow acceleration.

FIG. 17 is a flowchart illustrating the flow of blood pressure measurement processing in the third embodiment.

The processing from the acquisition of the received light signal (step S31) to the calculation / storage of the blood flow acceleration (step S33) is the same as that of the first embodiment.

Next, the calculation unit 202 derives the blood pressure index value based on the blood flow acceleration and stores it in the storage unit 150 (step S34). Specifically, when the blood pressure index value is BFV (unit: none) and the blood flow acceleration is diff (unit: cm / s ² ), the blood pressure index value BFV can be derived using the equation (G). That is, in this example, the blood flow acceleration itself is used as the blood pressure index value.
BFV = diff ... (G)

The processing from the calculation / storage of blood pressure (step S35) to the output of the measurement result (step S36) after step S34 is the same as that of the first embodiment.

According to the blood pressure measuring device of the present embodiment, the blood pressure index value is derived based only on the blood flow acceleration, so that the blood pressure index value can be derived by a lighter process than that of the first embodiment. it can.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described. FIG. 18 is an external view of the blood pressure measuring system 50 according to the fourth embodiment.

The blood pressure measurement system 50 of the fourth embodiment has functions as an acquisition unit for acquiring a received signal, a calculation unit for deriving a blood pressure index value, and an output unit for outputting information based on the blood pressure index value. It is composed of an apparatus main body 51, an irradiation unit that irradiates a laser beam, and a light receiving signal detection unit 52 that includes a light receiving unit that receives the laser light reflected or transmitted in the body.

As the blood pressure measuring device main body 51, for example, a smartphone can be used. In this case, a blood pressure measurement program for causing the CPU of the smartphone to function as an acquisition unit and a calculation unit is installed in the smartphone. As a result, the smartphone can be used as the blood pressure measuring device main body 51. In addition, a touch panel display and a speaker provided in the smartphone are used as an output unit for outputting information based on the blood pressure index value.

The light receiving signal detection unit 52 has the same configuration as the blood pressure measuring device 10 of the first embodiment except that it does not have the functions of the acquisition unit and the calculation unit.

Both the blood pressure measuring device main body 51 and the received light signal detection unit 52 are provided with a communication unit and are connected via a wireless or wired communication line. When the blood pressure measuring device main body 51 and the received signal detection unit 52 are connected by a wireless line, for example, a communication standard such as Bluetooth (registered trademark) or wireless LAN (Local Area Network) can be used. Further, when connecting the blood pressure measuring device main body 51 and the received light signal detection unit 52 by a wired line, for example, a connection standard such as USB (Universal Serial Bus) can be used.

Since the functional configuration and processing flow other than the above are the same as those in the first embodiment, detailed description thereof will be omitted here.

According to the blood pressure measuring device of the present embodiment, since the smartphone can be used as the blood pressure measuring device main body, the same as in each of the above embodiments, only by newly adding the light receiving signal detection unit 52 and the blood pressure measuring program. Blood pressure can be measured. Since the light-receiving signal detection unit 52 only detects the light-receiving signal and does not execute the blood pressure measurement process, the device configuration is simple and the cost can be reduced as compared with the case where the light-receiving signal detection unit 52 has the blood pressure measurement function. Further, the touch panel display of a smartphone is generally larger than a wristwatch-type device. If such a large touch panel display is used for displaying the measurement result, the visibility and operability of the user are also improved.

A computer may be used instead of the smartphone as the main body of the blood pressure measuring device. A computer is, for example, a server on the cloud. The server is communicably connected to the light receiving signal detection unit 52 via a communication line such as the Internet. The server acquires a light-receiving signal from the light-receiving signal detection unit 52 via a communication line, and executes a blood pressure measurement process for deriving a blood pressure index value based on the acquired light-receiving signal. Further, the server transmits the measurement result to the light receiving signal detection unit 52. Servers often have higher processing power than smartphones. Therefore, if the server is used as the main body of the blood pressure measuring device, the measurement result can be obtained in a short time. Further, if the data storage function of the server is used, the measurement result can be saved in the server, and good convenience is ensured.

[Modification example]
Although the present invention has been described above based on its preferred embodiment, the embodiment to which the present invention can be applied is not limited to the above-described embodiment.

The calculation of the heart rate is not limited to the mode performed by counting the number of peaks of the volumetric pulse wave included in the received signal as described above, but is calculated based on the received signal and has the same periodicity as the volume pulse wave. This may be done by counting the number of peaks of the signal of the element value of. For example, when the values of blood flow velocity and / or blood flow acceleration are continuously acquired and graphed, the waveform is different from that of the volumetric pulse wave, but it has the same periodicity as the volume pulse wave. / Or the heart rate may be calculated based on the blood flow acceleration. In addition, it is possible to calculate the blood flow rate from the power spectrum calculated based on the received signal. When the value of the blood flow is continuously acquired and graphed, the heart rate may be calculated based on the blood flow because the waveform is different from that of the volumetric pulse wave but has the same periodicity as the volumetric pulse wave. ..

Regarding the derivation of the blood pressure index value, the storage unit 150 stores a table showing the correspondence between the blood flow acceleration and the blood pressure index value and / or a table showing the correspondence between the blood flow acceleration and the heart rate and the blood pressure index value. The blood pressure index value may be derived by referring to the table based on the blood flow acceleration and / or the heart rate calculated by the calculation unit 202. As described above, as a method for deriving the blood pressure index value, both the method using a table and the method using a calculation formula as shown in the above embodiment have the correlation between the blood flow acceleration and the blood pressure, and the blood pressure. / Or included in the method of deriving a blood pressure index value based on the correlation between heart rate and blood pressure.

Further, in the blood pressure measurement process, when the received signal is first acquired, it is determined whether the intensity of the received signal is equal to or higher than a predetermined threshold value, and if the intensity of the received signal is less than the threshold value, the blood pressure measurement process is performed. It may be interrupted. If the blood pressure measuring device is not properly attached and fixed to the measurement site of the person to be measured, the blood pressure index value and / or the blood pressure cannot be measured accurately. If the intensity of the received signal is less than the threshold value, it is highly possible that the blood pressure measuring device is not properly attached and fixed to the measurement site of the person to be measured. In this case, it is useless to interrupt the blood pressure measuring process. It is possible to prevent the processing from being performed.

In addition, when the blood flow acceleration is acquired in the blood pressure measurement process, it is determined whether the blood flow acceleration is within a predetermined threshold range (for example, a range assumed by the human body), and the blood flow acceleration is within the threshold range. If it is out of the range, the blood pressure measurement process may be interrupted. Similarly, at the stage of acquiring the heart rate, it is determined whether the heart rate is within a predetermined threshold range (for example, a range assumed by the human body), and if the heart rate is out of the threshold range, it is determined. , The blood pressure measurement process may be interrupted. If it is out of the range of blood flow acceleration and / or heart rate threshold, it is highly possible that the measurement cannot be performed accurately due to some abnormality. In this case, it is useless to interrupt the blood pressure measurement process. It is possible to prevent the processing from being performed.

Further, the output of the measurement result is not limited to the mode in which the icon as shown in FIG. 13 is displayed or the blood pressure index value is displayed on the meter as shown in FIG. 14, and a plurality of states of blood pressure are set to each state. Other aspects can be used, such as the aspect indicated by the corresponding color.

In addition, at least one of the real-time measured value of the blood pressure index value, the diurnal variation of the blood pressure index value, and the comparison of the blood pressure index value with the past measured value is displayed on the display unit 120, or the above information is voiced. May be output from the sound output unit 130. Here, the comparison of the blood pressure index value with the past measured value is, for example, a comparison between the real-time measured value and the blood pressure index value at the same time on the previous day, and the real-time measured value and the blood pressure index value in the predetermined time zone on the previous day. It means a comparison with past measured values, such as a comparison with the average value of the above, a comparison between the real-time measured value and the average value of the blood pressure index value for one week. By outputting such information, useful information about the value of the blood pressure index value, the state of blood pressure fluctuation, and the comparison with the past data for the reference person of the measurement result including the subject. Can be provided.

In addition, at least one of the real-time measured value of blood pressure, the diurnal variation of blood pressure, and the comparison with the past measured value of blood pressure is displayed on the display unit 120, and the above information is output from the sound output unit 130 by voice. You may. Here, the comparison with the past measured value of blood pressure is, for example, the comparison between the real-time measured value and the blood pressure at the same time on the previous day, and the comparison between the real-time measured value and the average value of the blood pressure in the predetermined time zone on the previous day. , Means a comparison with past measurements, such as a comparison between real-time measurements and weekly mean blood pressure. By outputting such information, useful information about the value of the blood pressure index value, the state of blood pressure fluctuation, and the comparison with the past data for the reference person of the measurement result including the subject. Can be provided.

Further, when the blood pressure index value and / or the measured value of blood pressure exceeds a predetermined threshold value, for example, a display prompting attention is displayed on the display unit 120, or an alert sound is output to the sound output unit 130. Information indicating an abnormality may be output from the output unit, such as output from. By adopting such an aspect, it is possible to call attention when the blood pressure of the person to be measured is high.

Of course, other than the above, it can be changed as appropriate without departing from the spirit of the present invention. In addition to the program, the technique of the present disclosure extends to a storage medium for storing the program non-temporarily.

The entire disclosure of Japanese Application Japanese Patent Application No. 2019-103867 filed on June 3, 2019 is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are to the same extent as if the individual documents, patent applications, and technical standards were specifically and individually stated to be incorporated by reference. Incorporated herein by reference.

Claims (18)

1. With at least one processor
   The processor
   Acquires the received light signal detected based on the laser beam emitted into the body of the person to be measured,
   A blood flow velocity is calculated by performing a calculation based on the laser Doppler method on the acquired received signal, a blood flow acceleration is calculated based on the calculated blood flow velocity, and a blood pressure index is calculated based on the calculated blood flow acceleration. A blood pressure measuring device that derives values.
2. The blood pressure measuring device according to claim 1, wherein the processor derives the blood pressure index value based on the correlation between the blood flow acceleration and the blood pressure.
3. The blood pressure measuring device according to claim 1 or 2, wherein the processor calculates a heart rate based on a time change of the received signal, and derives the blood pressure index value based on the calculated blood flow acceleration and the heart rate. ..
4. The blood pressure measuring device according to claim 3, wherein the processor derives the blood pressure index value based on the correlation between blood flow acceleration and blood pressure and the correlation between heart rate and blood pressure.
5. The processor further detects the behavioral state of the subject to be measured.
   The blood pressure measuring device according to claim 3 or 4, wherein the processor derives the blood pressure index value based on the behavioral state of the person to be measured, the blood flow acceleration, and the heart rate.
6. The processor
   The blood pressure index value is BFV,
   The heart rate is HR,
   When the blood flow acceleration is diff,
   BFV = HR x diff ... (1)
   The blood pressure measuring device according to claim 4, wherein the blood pressure index value is calculated using the equation (1) represented by.
7. The processor further detects the behavioral state of the subject to be measured.
   The processor
   The constant that adjusts the weighting of the heart rate HR is a ₁ ,
   When the constant for adjusting the weighting of the blood flow acceleration diff is b ₁ .
   The constant a ₁ and the constant b ₁ are determined based on the behavioral state of the person to be measured.
   BFV = HR x diff x (a ₁ x HR + b ₁ x diff) / (HR + diff) ... (2)
   The blood pressure measuring device according to claim 6, wherein the blood pressure index value is calculated using the equation (2) represented by.
8. The blood pressure according to any one of claims 1 to 7, wherein the processor calculates the blood pressure at the time of measurement based on the reference blood pressure of the subject to be measured and the blood pressure index value acquired in advance. measuring device.
9. The processor
   The blood pressure at the time of the measurement is BP,
   The blood pressure index value is BFV,
   A constant determined based on at least one of the calculation method and measurement condition of the blood pressure index value is a _2.
   If a constant determined based on the reference blood pressure was b _2,
   BP = a ₂ x BFV + b ₂ ... (3)
   The blood pressure measuring device according to claim 8, wherein the blood pressure at the time of the measurement is calculated by using the formula (3) represented by.
10. The blood pressure measuring device according to any one of claims 1 to 9, further comprising an output unit that outputs information based on the blood pressure index value derived by the processor.
11. The output unit according to claim 10, wherein the output unit outputs at least one of a real-time measured value of the blood pressure index value, a diurnal variation of the blood pressure index value, and a comparison of the blood pressure index value with a past measured value. Blood pressure measuring device.
12. The processor calculates the blood pressure at the time of measurement based on the reference blood pressure as a reference of the subject and the blood pressure index value acquired in advance.
    The blood pressure measuring device according to claim 10 or 11, wherein the output unit outputs at least one of a real-time measured value of the blood pressure, a diurnal variation of the blood pressure, and a comparison with a past measured value of the blood pressure.
13. The blood pressure according to any one of claims 10 to 12, wherein the output unit outputs information indicating an abnormality when the blood pressure index value derived by the processor exceeds a predetermined threshold value. measuring device.
14. An irradiation unit that irradiates a laser beam inside the body of the person to be measured, a light receiving unit that receives the laser light reflected or transmitted inside the body, a processor, and an output unit that integrally hold the person to be measured. The blood pressure measuring device according to any one of claims 10 to 13, further comprising a portable housing.
15. The blood pressure measuring device according to claim 14, wherein the output unit is a display.
16. The blood flow velocity is calculated by acquiring a light-receiving signal detected based on the laser beam radiated into the body of the person to be measured and performing a calculation based on the laser Doppler method on the acquired light-receiving signal. A blood pressure measuring device main body including at least one processor that calculates the blood flow acceleration based on the velocity and derives the blood pressure index value based on the calculated blood flow acceleration.
    A blood pressure measurement system including an irradiation unit that irradiates a laser beam inside the body of the person to be measured, and a light receiving signal detection unit that includes a light receiving unit that receives the laser light reflected or transmitted inside the body.
17. Acquires the received light signal detected based on the laser beam emitted into the body of the person to be measured,
    The blood flow velocity is calculated by performing an operation based on the laser Doppler method on the acquired received signal.
    The blood flow acceleration is calculated based on the calculated blood flow velocity, and the blood flow acceleration is calculated.
    A blood pressure measurement method for deriving a blood pressure index value based on the calculated blood flow acceleration.
18. The procedure for acquiring the received light signal detected based on the laser beam emitted into the body of the person to be measured, and
    The procedure for calculating the blood flow velocity by performing an operation based on the laser Doppler method on the acquired received signal, and
    The procedure for calculating the blood flow acceleration based on the calculated blood flow velocity and
    A blood pressure measurement program that causes a computer to execute a procedure for deriving a blood pressure index value based on the calculated blood flow acceleration.

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