JP4881177B2 - Biological information measuring device - Google Patents

Description

  The present invention relates to a biological information measuring apparatus that is used to evaluate blood fluidity in a living body, and in particular, measures the flow velocity of blood flowing in a blood vessel.

  As one of the examination items for judging the health condition of the human body, blood rheology measurement focusing on blood fluidity has attracted attention. As a means for measuring blood rheology (fluidity), a micro-channel flow analyzer has been developed that measures the time for a certain amount of blood collected from a subject to pass through a micro-channel (micro channel) (Non-Patent Document). 1). At present, the micro-channel flow analyzer is a standard machine in blood rheology measurement.

  However, as described above, blood must be collected as described above for measurement using a micro-channel flow analyzer, and measurement is limited to medical institutions, and it is not always easy for everyone to check their health. No. In addition, blood sampling has a large physical and psychological burden on the subject, and the number of measurement operations that can be performed per day is limited to several times at most, so that there is a problem that continuous data cannot be obtained in time series. is there.

In order to solve the above-described problems associated with blood collection, an ultrasonic signal is transmitted from the surface of the living body to the blood vessel in the living body without requiring blood collection, and propagates in the living body to the blood flow in the blood vessel. A non-invasive Doppler type biological information measuring device that measures blood flow velocity from an ultrasonic Doppler shift signal obtained by reflection has already been proposed (see Patent Document 1).
This device determines that the blood fluidity is low, that is, the viscosity is high if the blood flow velocity is slow, while the fluidity is high if the blood flow velocity is slow, that is, the viscosity is low. By measuring the blood flow velocity, blood viscosity, which is cited as one of indices indicating blood rheology, is evaluated from the blood flow velocity in the living body.
JP 2003-159250 A Keiji Kikuchi “Measurement of whole blood fluidity using a capillary model” (Food Research Result Information, NO.11, 1999)

  However, ultrasonic Doppler measurement that measures blood flow velocity from the Doppler shift of ultrasonic waves that propagate in the living body and reflect on the blood flow in the blood vessel needs to greatly amplify a minute signal. The influence of the noise generated from the amplifier circuit is large, and there is a problem that a large noise component is easily included in the output signal and it is difficult to obtain a signal having an excellent S / N ratio (signal to noise ratio). Further, it is difficult to remove only noise without distorting the spectrum of a signal that is originally necessary with a simple filter circuit. Furthermore, in the living body being measured, there are veins and numerous capillaries in addition to arteries suitable for blood flow velocity measurement for evaluating blood rheology, and background signals ( It is difficult to accurately measure the blood flow velocity only in the artery.

  Therefore, the present invention allows anyone other than medical professionals to easily measure an accurate blood flow velocity without collecting blood, and calculates the blood flow velocity with high accuracy by reducing the influence of noise. It is an object of the present invention to provide a biological information measuring device and a biological information calculation method that can be used.

  In order to solve the above problems, a first feature according to the present invention is that a transmitter that transmits ultrasonic waves toward blood flowing through a living body, and a reflected wave that is reflected from the living body by the ultrasonic waves are received. A biological information measuring apparatus having a transmission / reception unit including a plurality of reception units, wherein the plurality of transmission / reception units include the transmission unit arranged along a predetermined direction and the first transmission / reception unit including the reception unit, and the predetermined direction. And a second transmitting / receiving unit having the transmitting unit and the receiving unit arranged along a direction orthogonal to the frequency of the reflected wave received by the first transmitting / receiving unit and the transmitted A first calculation unit that calculates a difference from the ultrasonic frequency as a first frequency, and a difference between the frequency of the reflected wave received by the second transmission / reception unit and the frequency of the transmitted ultrasonic wave is a second frequency. Calculated as A difference information calculation unit that calculates, as difference information, a difference between the intensity corresponding to the first frequency and the intensity corresponding to the second frequency, and the calculated difference information, The gist of the present invention is to include a flow velocity calculation unit that calculates the velocity of blood flow.

  According to this feature, the transmission unit and the reception unit in the first transmission / reception unit are arranged along a predetermined direction. Thereby, the longitudinal direction of a thick blood vessel such as a venous blood vessel arranged along the predetermined direction and the arrangement direction of the transmission unit and the reception unit in the first transmission / reception unit become substantially parallel. For this reason, the angle formed by the longitudinal direction and the arrangement direction is substantially zero, which is the difference between the frequency of the reflected wave received by the first transmitting / receiving unit and the frequency of the transmitted ultrasonic wave. The first frequency is the highest value in principle based on the Doppler effect. This first frequency is caused by the interaction between blood and ultrasonic waves, and includes a Doppler shift frequency (having a noise component).

  On the other hand, the transmission unit and the reception unit in the second transmission / reception unit are arranged along a direction (orthogonal direction) orthogonal to the predetermined direction. Thereby, the angle formed by the arrangement direction (orthogonal direction) of the transmission unit and the reception unit in the second transmission / reception unit and the longitudinal direction of a thick blood vessel such as a venous blood vessel becomes approximately 90. As a result, the second frequency, which is the difference between the frequency of the reflected wave received by the second transmitter / receiver and the frequency of the transmitted ultrasonic wave, is the smallest value in principle based on the Doppler effect. This second frequency is caused more largely by noise components due to other factors than by the interaction between blood and ultrasonic waves.

  Thus, by calculating the difference between the first frequency based on the Doppler shift frequency and the second frequency based on the noise component as difference information, the noise component at the Doppler shift frequency can be reduced. Can be calculated with high accuracy.

  That is, according to the present invention, blood flow velocity that has a strong correlation with blood rheology can be measured non-invasively without collecting blood from a subject, and the influence of noise is reduced to increase blood flow velocity. It can be calculated with accuracy.

  The second feature of the present invention relates to the first feature of the present invention, and is summarized in that the predetermined direction is the same as the longitudinal direction of the arterial blood vessel.

A third feature of the present invention includes a transmission / reception unit including a plurality of transmission units that transmit ultrasonic waves toward blood flowing through a living body and a reception unit that receives reflected waves reflected from the living body by the ultrasonic waves. A biological information measurement method that operates in a biological information measurement device, wherein the plurality of transmission / reception units include a first transmission / reception unit including the transmission unit and the reception unit arranged along a predetermined direction, and the predetermined direction. And a second transmitting / receiving unit having the transmitting unit and the receiving unit arranged along a direction orthogonal to each other, and the frequency of the reflected wave received by the first transmitting / receiving unit and the transmitted ultrasonic wave Calculating a difference between the frequency of the reflected wave and the frequency of the reflected ultrasonic wave received by the second transmitting / receiving unit as the second frequency. Calculating the difference between the intensity corresponding to the first frequency and the intensity corresponding to the second frequency as difference information, and calculating the velocity of the blood flow using the calculated difference information And the step of performing.
A fourth feature of the present invention relates to the third feature of the present invention, and is summarized in that the predetermined direction is the same as the longitudinal direction of the arterial blood vessel.

  In the present invention, measurement is performed using an ultrasonic sensor including an ultrasonic transmission element and an ultrasonic reception element, and the velocity is derived from frequency distribution information (frequency spectrum data) calculated from the signal of the ultrasonic sensor. However, it detects and outputs a signal that changes in accordance with the blood flow velocity, and detects and outputs a background signal and a noise component that do not have the blood flow velocity component. Then, by subtracting the background signal and the noise component from the frequency spectrum data, spectral data mainly relating to the flow rate of arteriole blood remains in the differential data, and by deriving the velocity from the differential data, the influence of noise can be obtained. Minimal and more accurate blood flow velocity is required.

  According to the present invention, it is possible to measure a blood flow velocity that has a strong correlation with blood rheology in a non-invasive manner without collecting blood from a subject, and to reduce the influence of noise to increase the blood flow velocity with high accuracy. Can be calculated.

  The configuration of the embodiment will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the biological information measuring apparatus 1 of the present invention. 2 is a configuration diagram of each sensor used in the present invention, FIG. 2 (a) is a plan view, and FIG. 2 (b) is a side view. FIG. 3 and FIG. 3 are explanatory diagrams for explaining the measurement principle of the biological information measuring apparatus 1 of the present invention.

As shown in FIGS. 1 to 4, the biological information measuring apparatus 1 according to the present embodiment includes a flow rate sensor module 10 including ultrasonic sensors 1 a and 1 b and a correction sensor 5.
The ultrasonic sensors 1a and 1b include transmitting elements 2a and 2b that transmit ultrasonic waves toward blood flowing through the living body and receiving elements 3a and 3b that receive reflected waves reflected from the living body by the ultrasonic waves. The correction sensor 5 includes a transmitting element 6 that transmits ultrasonic waves toward blood flowing through the living body, and a receiving element 7 that receives reflected waves reflected from the living body by the ultrasonic waves.
The transmitting elements 2a and 2b and the receiving elements 3a and 3b in the ultrasonic sensors 1a and 1b according to the present embodiment are arranged along a predetermined direction (for example, the length direction of a venous blood vessel or an arterial blood vessel). The transmitting element 6 and the receiving element 7 in the correction sensor 5 are arranged along a direction orthogonal to the predetermined direction.

The transmitting elements 2a, 2b, and 6 constitute a transmitting unit. The receiving elements 3a, 3b, and 7 constitute a receiving unit. The ultrasonic sensors 1a and 1b constitute a first transmission / reception unit. The correction sensor 5 constitutes a second transmission / reception unit. Hereinafter, the configuration of the biological information measuring apparatus 1 will be described in detail.
The transmitting elements 2a and 2b and the receiving elements 3a and 3b of the ultrasonic sensors 1a and 1b are all piezoelectric vibrating elements in which an electrode thin film is formed on a piezoelectric ceramic plate. In the present embodiment, the ultrasonic frequency is 15 MHz. In the present invention, two pairs of ultrasonic sensors 1a and 1b are used, and are arranged on the sensor support member 4 so that the directions of directivity of ultrasonic emission and reception are not parallel to each other. As shown in FIG. 3, a living body 71 (such as a subject's fingertip) as a measurement target is brought into contact with the flow velocity sensor module 10 to measure a blood flow velocity.

The ultrasonic wave (transmitted wave 78a) emitted from the transmitting element 2a of the ultrasonic sensor 1a propagates through the living tissue and is reflected by blood flowing in the blood vessel (mainly considered as red blood cells). The reflected wave 79a changes to a signal subjected to Doppler shift according to the blood flow speed. This reflected wave is received by the receiving element 3a.
Similarly for the ultrasonic sensor 1b, the ultrasonic wave (transmitted wave 78b) emitted from the transmitting element 2b is reflected by the Doppler shift due to blood flow and is detected by the receiving element 3b. However, the ultrasonic sensors 1a and 1b Then, the directivity directions in which ultrasonic waves are emitted are different. The blood flow velocity can be calculated from the angle difference α between the ultrasonic sensors 1a and 1b and the Doppler shift frequencies ΔFa and ΔFb obtained from the signals of the ultrasonic sensors 1a and 1b.

  Next, the flow velocity measuring unit 52 includes a flow velocity sensor 10 including two pairs of ultrasonic sensors 1, two detection circuits 23a and 23b, filter circuits 24a and 24b, amplification circuits 25a and 25b, and an A / D converter 26a. , 26b. The signals of the receiving elements 3a and 3b that have received the reflected waves 79a and 14b are detected by the detection circuits 23a and 23b, and only the Doppler shift signal component from which the ultrasonic carrier component (base component) is removed is extracted. The frequency components unnecessary for the A / D conversion process are removed by the filter circuits 24a and 24b, and amplified by the amplifier circuits 25a and 25b, respectively. The Doppler shift signal is an analog signal, but is converted into digital data by the A / D converters 26 a and 26 b and temporarily stored in the buffer memory 31.

  As shown in FIGS. 2 and 4, the correction measurement unit 53 includes the correction ultrasonic sensors 5 a and 5 b installed so as to be orthogonal to the arrangement (direction) of the ultrasonic sensors 1 a and 1 b and the ultrasonic sensors 1 a and 1 b. The detection circuit 23c, the filter circuit 24c, the amplifier circuit 25c, and the A / D converter 26c are connected. The frequency (sampling rate) of A / D conversion in the measurement is the same as that of the flow velocity measurement unit 52.

  As described above, the flow velocity measuring unit 52 detects the difference between the reflected wave signal received by the ultrasonic sensor 1 and the transmitted ultrasonic signal as a Doppler shift signal. Similarly, the correction measurement unit 53 also detects the difference between the reflected wave signal received by the correction sensor 5 and the transmitted ultrasonic signal as a Doppler shift signal. Then, the arithmetic processing unit 43 described later has a first frequency (frequency distribution data) that is a frequency of the Doppler shift signal based on the ultrasonic sensor 1 and a second frequency (a frequency of the Doppler shift signal that is based on the correction sensor 5). Frequency distribution data) and the blood flow velocity is calculated.

  Here, the function of emitting an ultrasonic transmission wave 88 in the living body from the transmitting element 6 and detecting the reflected wave 89 by the receiving element 7 is the same as that of the flow velocity measuring unit 52, but the blood flow in the artery is detected. Since the arrangement (direction) of the ultrasonic sensors 1a and 1b to be performed and the arrangement of the ultrasonic sensors for correction 5a and 5b are orthogonal, the blood flow velocity component that can be detected by the flow velocity measuring unit 52 cannot be detected by the correction measuring unit 53. Therefore, the correction measurement unit 53 detects only a low-speed signal and noise component of the blood flow. Further, unlike the flow rate measurement unit 52, the correction measurement unit 53 is a function that detects only the background reflection signal and noise component from the blood in the capillary blood vessels, not the fast flow rate component of the blood flow in the artery. A function for detecting an angle of a blood flow velocity vector, which will be described later, is not necessary, and only one circuit block configuration may be used. Therefore, the correction ultrasonic sensors 5a and 5b may simply add both signals and input them to the amplifier circuit.

  Next, the speed calculation unit 51 includes a buffer memory 31 (31a, 31b, 31c) and an arithmetic processing device 43. The measurement data from each ultrasonic sensor is A / D converted, and then temporarily stored in the buffer memory 31. The data in each buffer memory is sent to the arithmetic processing unit 43 for every fixed amount. Further, the data communication apparatus 50 can transmit data obtained by this apparatus to another terminal apparatus or a network.

  The arithmetic processing unit 43 includes a digital input unit 44 and a main storage unit 41 as described in detail below. The arithmetic processing unit 43 also includes a first frequency (frequency distribution data) that is the frequency of the Doppler shift signal based on the ultrasonic sensor 1 and a second frequency (frequency distribution) that is the frequency of the Doppler shift signal based on the correction sensor 5. Data), a difference calculation unit 49 that calculates the difference between the intensity corresponding to the first frequency and the intensity corresponding to the second frequency as difference information (difference data), and the calculated difference An angle calculation unit 46 and a speed calculation unit 48 that calculate blood flow velocity using data are provided. The flow velocity measurement unit 52 and the frequency analysis unit 45 constitute a first calculation unit. The correction measurement unit 53 and the frequency analysis unit 45 constitute a second calculation unit. The angle calculation unit 46 and the speed calculation unit 48 constitute a flow rate calculation unit.

  Specifically, the arithmetic processing device 43 performs arithmetic processing on the detection signal output from the measurement unit to calculate frequency distribution data, the frequency distribution data from the flow velocity measurement unit 52 and the correction measurement unit 53. A difference calculation unit 49 that calculates difference data of frequency distribution data from, an angle calculation unit 46 that calculates the direction angle of blood flow by calculating the frequency distribution data, and the value of the direction angle calculated in the angle calculation unit The flow rate calculation unit 48 for calculating the flow rate value of the blood is provided.

  The digital input unit 44 receives data from the ultrasonic sensors 1a and 1b and the correction ultrasonic sensor 5 digitized by the A / D converters 26a, 26b, and 26c via the buffer memories 31a, 31b, and 31c. After receiving it, it has a function of transferring it to the main storage unit 41 and storing it.

  Note that the above-described calculation units (frequency analysis unit 45, angle calculation unit 46, flow velocity calculation unit 48, difference calculation unit 49) are specifically a signal calculation processing unit that performs calculation processing and control using a computer function, and Although it will be described later in detail, the digital data stored in the main storage unit 41 is appropriately extracted and subjected to arithmetic processing. If necessary, the arithmetic processing is performed while being stored in the main storage unit 41 again. It has a function.

  Hereinafter, the frequency analysis unit 45, the angle calculation unit 46, and the flow velocity calculation unit 48 will be described in detail.

  First, the frequency analysis unit 45 performs Fourier transform on the digital data of the Doppler shift signals of the ultrasonic sensor 1a and the ultrasonic sensor 1b obtained by the above measurement in the signal calculation processing unit and the general-purpose calculation processing unit of the calculation processing device 43. It has a function of converting into frequency distribution (spectrum) data by (FFT) processing and storing the converted frequency distribution data in the main storage unit 41.

  For example, the frequency analysis unit 45 sets the sampling frequency of the A / D converters 26a and 26b to fs = 20 kHz, the number of FFT processes to Nf = 256, and Nf = 512 frequency distribution data every 0.0128 seconds. Then, frequency distribution data (Doppler shift frequency and Doppler shift signal intensity distribution corresponding to the Doppler shift frequency) every 0.0256 seconds are obtained. However, the number of data in the FFT processing and the time interval of the FFT processing do not necessarily match. For example, 256 pieces of data can be processed at intervals of 0.01 seconds.

  Similarly, data from the correction measurement unit 53 is separately subjected to FFT processing and converted to frequency distribution data. Further, the difference processing calculation unit 49 performs a calculation of subtracting the frequency distribution data of the correction measurement unit 53 (correction ultrasonic sensor 5) for each frequency element from the frequency distribution data from the flow velocity measurement unit 52 (ultrasonic sensor 1). The background reflection and the noise component are canceled out, and data in which only the fast flow velocity component of the blood flow in the arterial blood vessel remains is calculated.

  In the present embodiment, the Doppler shift signals detected by the ultrasonic sensors 1a and 1b are converted to Doppler shift frequencies Fa and Fb as the frequencies of the peak portions of the frequency distribution data converted by the frequency analysis unit 45 and the difference calculation unit 49, respectively. It is used for the calculation processing in the angle calculation unit 46 and the flow velocity calculation unit 48 described below.

  Next, before describing the angle calculator 46 and the flow velocity calculator 48, the calculation principle for calculating the blood flow velocity from the Doppler shift signals (Doppler shift frequency) obtained from the ultrasonic sensors 1a and 1b will be described.

  When the Doppler shift frequency obtained from the data of the ultrasonic sensor 1a by the above method is Fa and the Doppler shift frequency obtained from the data of the ultrasonic sensor 1b is Fb, the blood flow velocity Vh can be derived by the following equation. . Here, θ is an angle formed between the flow velocity sensor module 10 (ultrasonic sensor 1a or 1b) and the direction of blood flow. α is an angle formed by directivity of emission and reception of ultrasonic waves of the two ultrasonic sensors. c is the speed of sound in the living body. Fs is a transmission frequency (drive frequency) of the ultrasonic sensor.

Vh = cFa / 2Fscosθ (Formula 1)
θ = atan ((− cos α−Fb / Fa) / sin α) (Formula 2)
Here, the angle calculation unit 46 has the function of calculating the above-mentioned θ, and the flow rate calculation unit 48 has the function of calculating the Vh. The angle calculation unit 46 and the flow velocity calculation unit 48 perform calculation processing using the frequency distribution data calculated by the frequency analysis unit 45 to obtain the above θ (blood flow direction angle) and Vh (blood flow velocity). calculate. Note that θ may be calculated as shown in Equation 2 or may be determined in advance.

  Thus, the flow velocity calculation unit 48 functions as a device that calculates the blood flow velocity based on the frequency of the signal output from the ultrasonic sensor and the calculated Doppler shift frequency.

  Since the output signals of the ultrasonic sensors 1a and 1b are small, a large amplification factor is required to perform A / D conversion, and it is easily affected by external noise. If noise is mixed in the signal, the frequency distribution is greatly changed, an accurate Doppler shift frequency cannot be obtained, and a large error occurs in the calculated blood flow velocity. Therefore, a countermeasure for removing or reducing noise is required as in the present invention.

  Specifically, the transmitting elements 2a and 2b and the receiving elements 3a and 3b in the ultrasonic sensor 1 are arranged along a predetermined direction. Thereby, the longitudinal direction of a thick blood vessel such as a venous blood vessel arranged along a predetermined direction and the arrangement direction of the transmitting elements 2a and 2b and the receiving elements 3a and 3b become substantially parallel. For this reason, the angle formed by the longitudinal direction and the arrangement direction is substantially zero, which is the difference between the frequency of the reflected wave received by the ultrasonic sensor 1 and the frequency of the transmitted ultrasonic wave. The first frequency is the highest value in principle based on the Doppler effect. This first frequency is caused by the interaction between blood and ultrasonic waves as described above, and includes a Doppler shift frequency (having a noise component).

  On the other hand, the transmitting element 6 and the receiving element 7 in the correction sensor 5 are arranged along a direction (orthogonal direction) orthogonal to a predetermined direction. As a result, the angle formed by the arrangement direction (orthogonal direction) of the transmitting element 6 and the receiving element 7 in the correction sensor 5 and the longitudinal direction of a thick blood vessel such as a venous blood vessel becomes approximately 90. As a result, the second frequency, which is the difference between the frequency of the reflected wave received by the correction sensor 5 and the frequency of the transmitted ultrasonic wave, is the smallest value in principle based on the Doppler effect. This second frequency is caused more largely by noise components due to other factors than by the interaction between blood and ultrasonic waves.

  Accordingly, by calculating the difference between the first frequency based on the Doppler shift frequency and the second frequency based on the noise component as difference data, the noise component at the Doppler shift frequency can be reduced. Can be calculated with high accuracy.

  In other words, the background reflection component and the external noise component inside the living body mixed in each ultrasonic sensor can be subtracted from the Doppler shift frequency, and the influence of noise and background reflection can be reduced to improve the blood flow velocity with higher accuracy. Can be calculated.

  In other words, the blood flow velocity having a strong correlation with blood rheology can be measured non-invasively without collecting blood from the subject, and the noise component can be reduced from the signal obtained from the ultrasonic sensor. N ratio is improved, more accurate blood flow velocity measurement is possible, and anyone other than a medical professional can easily check the accurate rheology without taking blood from the subject, and the health condition of the subject Can be used for confirmation.

  In addition, since the blood is pushed out by the blood pressure P of the living body and flows, the blood flow velocity Vh is considered to be affected by the blood pressure of the living body. Therefore, in consideration of the relationship between the blood flow velocity of the subject and the blood pressure value, in order to correct the influence of the blood pressure in the flow velocity calculation unit 48, the blood flow velocity Vh is the maximum blood pressure Ph measured by the blood pressure measuring instrument. It is also possible to perform arithmetic processing by dividing and calculating the corrected blood flow velocity Vc (= Vh / Ph) using the value of Vh / Ph.

  If the corrected blood flow velocity Vc is large, the blood fluidity in the living body is relatively high (viscosity is low), and if the correction blood flow velocity Vc is small, the blood fluidity is low (viscosity is high). It is possible to more accurately evaluate the fluidity of blood in a living body.

  The blood flow rate sensor module is not limited to the configuration shown in FIG. 2 and may have the configuration shown in FIG. The configuration shown in FIG. 2 is an example in which an ultrasonic sensor for correction is arranged in a target shape to detect background reflection in a living body without deviation, and an optical sensor 11 or the like as an auxiliary function is mounted. The optical sensor 11 can automatically detect the presence or absence of a measurement target. The configuration shown in FIG. 4 is an example of the simplest configuration that implements the functions of the present invention.

  The present invention is not only capable of measuring blood fluidity (ease of flow) for the purpose of medical care and health maintenance / promotion, but also the activity status of the living body (human body) and blood flow in various parts of the living body. It can also be used in measurement to know the correlation between states.

  In the present embodiment and each modified example, a finger has been described as an example of a living body. However, the present invention is not limited to this and may be a wrist, an arm, or the like.

  In addition, although an example of the present invention has been described, the present invention is merely illustrated as a specific example, and the present invention is not particularly limited, and the specific configuration and the like in the embodiment can be appropriately changed in design. In addition, each of the specific configurations of the embodiment and each modified example can be combined. Furthermore, the actions and effects of the embodiment are merely a list of the most preferable actions and effects resulting from the present invention, and the actions and effects of the present invention are not limited to those described in the embodiments.

It is a block diagram which shows the structure of the biological information measuring device which concerns on this invention. It is a figure which shows the structure of each sensor which concerns on this invention. It is a figure explaining the measurement principle of the biological information measuring device concerning the present invention. It is a figure explaining the measurement principle of the biological information measuring device concerning the present invention. It is a figure which shows the structure of each sensor which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a, 1b Ultrasonic sensor 2a, 2b Transmitting element 3a, 3b Receiving element 4 Sensor support member 5a, 5b Correction ultrasonic sensor 6a, 6b Transmitting element 7a, 7b Receiving element 10 Flow rate sensor module 11 Optical sensor 21 Oscillation circuit 23a, 23b Detection circuit 24a, 24b Filter circuit 25a, 25b Amplification circuit 26a, 26b A / D converter 27 Amplification circuit 28 Filter circuit 29 A / D converter 31a, 31b, 31c Buffer memory 41 Main storage unit 43 Processing unit 44 Digital Input / output unit 45 Frequency analysis unit 46 Angle calculation unit 48 Flow rate calculation unit 49 Difference calculation unit 50 Data communication device 51 Speed calculation unit 52 Flow rate measurement unit 53 Correction measurement unit 71 Living body (fingertip)
72 Arterial blood vessel 73 Venous blood vessel 78a, 78b Transmitted wave 79a, 79b Reflected wave 88a, 88b Transmitted wave 89a, 89b Reflected wave

Claims (4)

A biological information measuring apparatus having a transmission / reception unit including a transmission unit that transmits ultrasonic waves toward blood flowing through a living body, and a reception unit that receives reflected waves reflected from the living body by the ultrasonic waves,
The plurality of transmission / reception units include: a first transmission / reception unit including the transmission unit and the reception unit arranged along a predetermined direction; the transmission unit arranged along a direction orthogonal to the predetermined direction; A second transmission / reception unit having a reception unit,
A first calculation unit that calculates a difference between the frequency of the reflected wave received by the first transmission / reception unit and the frequency of the transmitted ultrasonic wave as a first frequency;

A second calculation unit that calculates a difference between the frequency of the reflected wave received by the second transmission / reception unit and the frequency of the transmitted ultrasonic wave as a second frequency;

A difference information calculation unit that calculates a difference between the intensity corresponding to the first frequency and the intensity corresponding to the second frequency as difference information;
A biological information measurement device comprising: a flow rate calculation unit that calculates the blood flow velocity using the calculated difference information.   The biological information measuring apparatus according to claim 1, wherein the predetermined direction is the same as a longitudinal direction of the arterial blood vessel. Biological information that operates in a biological information measuring apparatus having a transmission / reception unit that includes a transmission unit that transmits ultrasonic waves toward blood flowing through the living body and a reception unit that receives reflected waves reflected from the biological body by the ultrasonic waves A measuring method,
The plurality of transmission / reception units include: a first transmission / reception unit including the transmission unit and the reception unit arranged along a predetermined direction; the transmission unit arranged along a direction orthogonal to the predetermined direction; A second transmission / reception unit having a reception unit,
Calculating a difference between the frequency of the reflected wave received by the first transceiver and the frequency of the transmitted ultrasonic wave as a first frequency;
Calculating a difference between the frequency of the reflected wave received by the second transceiver and the frequency of the transmitted ultrasonic wave as a second frequency;
Calculating a difference between the intensity corresponding to the first frequency and the intensity corresponding to the second frequency as difference information;
A biological information measurement method comprising: calculating the blood flow velocity using the calculated difference information.   The biological information measuring method according to claim 3, wherein the predetermined direction is the same as the longitudinal direction of the arterial blood vessel.

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