JP2015073835A - Biological information output device and method, and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately detect sudden change in a living body by suppressing influence of biological fluctuation in blood flow data.SOLUTION: A biological information output device (100) comprises: acquisition means (110) for acquiring blood flow data, which is data on a blood flow of a living body; normalization means (140) for normalizing an amplitude component, which is a component on fluctuation amplitude, included in the acquired blood flow data, by a blood flow volume component which is a component on a blood flow volume, included in the acquired blood flow data; and output means (150) for outputting normalization information which is information on the normalized amplitude component.

Description

  The present invention relates to a biological information output apparatus and method using data relating to measured blood flow, and a computer program technical field.

  As this type of device, for example, a system that measures the blood flow of a living body and determines the state of the living body according to the change in the measured blood flow is proposed (see Patent Document 1).

  Alternatively, the signal intensity obtained by integrating the intensity of each Doppler shift amount component is obtained from the Doppler signal obtained by the ultrasonic Doppler blood flow meter, and the change between the signal intensity at the maximum blood flow and the signal intensity at the minimum blood flow is obtained. An apparatus for calculating a ratio as an index of blood rheology has been proposed (see Patent Document 2).

  It is known that there is a correlation between the blood flow measured with a human earlobe and blood pressure (see Non-Patent Document 1).

JP-A-2005-192807 JP 2006-181268 A

Tetsuya Fujikawa, et al., “Measurement of Hemodynamics During Postural Changes Using a New Wearable Cephalic Laser Blood Flowmeter”, Circulation Journal Vol. 73, October 2009, Circ J 2009; 73: 1950-1955

  Depending on the measurement site and the condition of the subject, the blood flow may change irregularly at any time due to biological fluctuations such as partial vasoconstriction, vasomotion, and respiratory sway caused by reflex adjustment by the autonomic nerve. For this reason, there is a technical problem that, when the state of the living body is determined only by the blood flow volume as in the technique described in Patent Document 1, there is a high possibility of erroneous determination. In addition, the change ratio calculated as an indicator of blood rheology described in Patent Document 2 has a technical problem that it is difficult to detect a sudden change in the state of the subject.

  The present invention has been made in view of the above-mentioned problems, for example, and provides a biological information output device and method that can hardly detect the sudden change of a living body and that can detect a sudden change of the living body, and a computer program. And

  In order to solve the above-described problem, the biological information output device of the present invention includes an acquisition unit that acquires blood flow data that is data related to blood flow of the living body, and a component related to the blood flow included in the acquired blood flow data. A normalization unit that normalizes an amplitude component that is a component related to a fluctuation amplitude included in the acquired blood flow data and a normalization information that is information related to the normalized amplitude component are output based on a certain blood flow component. Output means.

  In order to solve the above-described problem, the biological information output method of the present invention includes an acquisition step of acquiring blood flow data that is data related to blood flow of the living body, and a component related to blood flow included in the acquired blood flow data. A normalization step for normalizing an amplitude component that is a component related to the fluctuation amplitude included in the acquired blood flow data and a normalization information that is information related to the normalized amplitude component are output based on a certain blood flow component. An output step.

  In order to solve the above-described problem, the computer program of the present invention uses a computer mounted on a biological information output device to acquire blood flow data that is data related to blood flow of the living body, and the acquired blood flow. A normalizing unit that normalizes an amplitude component that is a component related to a fluctuation amplitude included in the acquired blood flow data, based on a blood flow component that is a component related to a blood flow included in the data, and the normalized amplitude component It functions as an output means for outputting normalization information that is information.

  The effect | action and other gain of this invention are clarified from the form for implementing demonstrated below.

It is a block diagram which shows the structure of the biological monitor system which concerns on 1st Example. It is an example of a blood-flow data waveform. It is a flowchart which shows the biological monitor process which concerns on 1st Example. It is an example of a blood flow data waveform, a blood flow volume, a pulse wave amplitude, and a pulse wave amplitude after normalization. It is a block diagram which shows the structure of the biological monitor system which concerns on 2nd Example. It is a flowchart which shows the principal part of the biological monitor process which concerns on 2nd Example. It is a block diagram which shows the structure of the biological monitor system which concerns on 3rd Example.

  An embodiment according to the biological information output apparatus and the like of the present invention will be described.

(Biological information output device)
The biometric information output device according to the embodiment includes an acquisition unit, a normalization unit, and an output unit.

  The acquisition unit acquires blood flow data that is data relating to blood flow output from a known blood flow meter such as a laser Doppler blood flow meter or an ultrasonic Doppler blood flow meter. Here, “data related to blood flow” is not limited to data indicating the blood flow itself, but is a concept including a physical quantity or a parameter that varies according to the blood flow.

  For example, the normalization means including a memory, a processor, and the like is a component related to the fluctuation amplitude included in the acquired blood flow data by a blood flow component that is a component related to the blood flow included in the acquired blood flow data. Normalize the amplitude component.

  The output means outputs normalization information that is information on the normalized amplitude component. Here, the “information regarding the normalized amplitude component” is not limited to information (for example, a numerical value) indicating the normalized amplitude component itself, and corresponds to the normalized amplitude component and the biological information. It is a concept that includes information in a format desired by the user of the output device (for example, numerical values, graphs, colors, etc.).

  According to the inventor's research, the following matters have been found. That is, in the blood flow meter, blood flow data is often acquired based on a signal caused by Doppler shift of light or sound waves scattered by red blood cells moving in the blood. By the way, since blood is pumped out to the whole body by the heart, the moving speed of red blood cells differs between the systole of the heart (that is, at the time of maximum blood pressure) and the diastole of the heart (that is, at the time of minimum blood pressure). For this reason, blood flow data acquired by a blood flow meter fluctuates little by little according to the heartbeat. Therefore, the blood flow data includes a component caused by the blood flow (“blood flow component” according to the present invention) and a component caused by the heartbeat (“amplitude component” according to the present invention).

  For example, when the blood flow decreases as the blood pressure decreases, the living body works to increase (return) the blood pressure and to increase the cardiac output. It is thought that the (related) amplitude component increases. For this reason, it is considered that a sudden change in a living body can be detected by monitoring the amplitude component. On the other hand, the amplitude component is also affected by the fluctuation of the living body as it is, and it is difficult to appropriately detect the sudden change of the living body only with the amplitude component.

  Therefore, in this embodiment, the amplitude component is normalized by the blood flow component by the normalizing means. Since the blood flow component is also affected by biological fluctuation, it is considered that the influence of the biological fluctuation is reduced or offset by normalizing the amplitude component with the blood flow component. Therefore, sudden changes in the living body can be appropriately detected by referring to the normalization information output from the output means.

  In one aspect of the biological information output apparatus according to the embodiment, the normalizing unit normalizes the average value of the amplitude component in the predetermined period using the average value of the blood flow component in the predetermined period.

  According to this aspect, the amplitude component can be normalized relatively easily. Here, the “predetermined period” may be set as appropriate according to the operating conditions desired by the user of the biometric information output apparatus, but since the amplitude component is a target, the period is equal to or longer than a period corresponding to one heartbeat. Is desirable.

  In this aspect, the normalization means may normalize the average value of the amplitude component by dividing the average value of the amplitude component by the average value of the blood flow component.

  If comprised in this way, an amplitude component can be normalized appropriately and it is very advantageous practically.

  Alternatively, in another aspect of the biological information output apparatus according to the embodiment, the normalizing means uses the average value of the blood flow component in a period corresponding to one beat of the heart of the living body, and the amplitude in the period. Normalize the components.

  According to this aspect, the amplitude component can be normalized relatively easily. In addition, what is necessary is just to specify the period corresponded to one heartbeat using a well-known heart rate meter, a heart rate detector, etc., for example.

  In this aspect, the normalizing means may normalize the amplitude component by dividing a value indicating the amplitude component by an average value of the blood flow component.

  If comprised in this way, an amplitude component can be normalized appropriately and it is very advantageous practically.

  In another aspect of the biological information output apparatus according to the embodiment, the biological information output device further includes alarm means for issuing an alarm according to a comparison result between the output normalized information and a predetermined threshold value.

According to this aspect, when normalization information that is larger than the predetermined threshold or smaller than the predetermined threshold is output, an alarm can be issued to the user of the biological information output device, which is very advantageous in practice. Here, the “predetermined threshold value” is a value that determines whether or not to issue an alarm, and is set in advance as a fixed value or as a variable value according to some physical quantity or parameter. Such a predetermined threshold is obtained by, for example, obtaining a relationship between normalized information (that is, information on the normalized amplitude component) and the state of the living body, and based on the obtained relationship, a living body that needs attention. What is necessary is just to obtain | require as the value of the normalization information corresponding to this state.

(Biological information output method)
The biological information output method according to the embodiment includes an acquisition step of acquiring blood flow data that is data related to blood flow of the living body, and a blood flow component that is a component related to blood flow included in the acquired blood flow data. A normalization step of normalizing an amplitude component that is a component related to the fluctuation amplitude included in the acquired blood flow data, and an output step of outputting normalization information that is information related to the normalized amplitude component.

  According to the biological information output method according to the embodiment, as in the biological information output device according to the above-described embodiment, the influence of biological fluctuation is suppressed, and normalization information that enables appropriate detection of a sudden change in the biological body is provided. can do. In addition, also in the biological information output method which concerns on embodiment, the various aspects similar to the various aspects of the biological information output device which concern on embodiment mentioned above can be taken.

(Computer program)
The computer program according to the embodiment relates to a computer mounted on the biological information output device, an acquisition unit that acquires blood flow data that is data related to blood flow of the living body, and a blood flow rate included in the acquired blood flow data. Normalization means for normalizing the amplitude component, which is a component related to the fluctuation amplitude included in the acquired blood flow data, and normalization information, which is information related to the normalized amplitude component, based on the blood flow component that is the component It functions as output means for outputting.

  According to the computer program according to the embodiment, from a recording medium such as a RAM (Random Access Memory), a CD-ROM (Compact Disc Read Only Memory), a DVD-ROM (DVD Read Only Memory) or the like that stores the computer program. If the computer program is read and executed by a computer provided in the biometric information output device, or if the computer program is executed after being downloaded via the communication means, the biometric information output according to the above-described embodiment is performed. The device can be realized with relative ease. Thereby, similarly to the biological information output device according to the above-described embodiment, it is possible to provide normalized information that suppresses the influence of biological fluctuation and enables appropriate detection of a sudden change in the biological body.

  An embodiment according to the biological information output apparatus of the present invention will be described with reference to the drawings. In the following embodiments, as a specific example, a biological monitor system including a control unit corresponding to the biological information output device of the present invention will be described.

<First embodiment>
A first embodiment of the biological information output apparatus of the present invention will be described with reference to FIGS.

  The configuration of the biological monitor system according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing the configuration of the biological monitor system according to the first embodiment.

  In FIG. 1, the living body monitor system includes a blood flow measurement unit 10 and a control unit 100.

  A known blood flow meter such as a laser Doppler blood flow meter or an ultrasonic Doppler blood flow meter can be applied to the blood flow measurement unit 10. For example, a blood flow data waveform is output from the blood flow measurement unit 10 (see the solid line in FIG. 2). In addition, although the vertical axis of FIG. 2 describes “blood flow”, it is a concept including not only the blood flow itself but also physical quantities or parameters that change according to the blood flow. FIG. 2 is an example of a blood flow data waveform.

  The control unit 100 includes a data acquisition unit 110, a blood flow rate calculation unit 120, a pulse wave amplitude calculation unit 130, a pulse wave amplitude normalization unit 140, an output unit, and an alarm unit 150.

  The data acquisition unit 110 acquires blood flow data including a blood flow data waveform. The blood flow calculation unit 120 calculates a blood flow (see “dotted line B” in FIG. 2) based on the acquired blood flow data. In addition, since various known aspects, such as a method for obtaining from the product of the blood flow velocity and the number of blood cells, can be applied to the method for calculating the blood flow, a detailed description thereof will be omitted.

  The pulse wave amplitude calculation unit 130 calculates a pulse wave amplitude (that is, an amplitude caused by a heartbeat appearing in the blood flow data waveform: see, for example, “width A” in FIG. 2) based on the acquired blood flow data. Since various known modes can be applied to the pulse wave amplitude calculation method, a detailed description thereof is omitted.

  The pulse wave amplitude normalization unit 140 normalizes the calculated pulse wave amplitude with the calculated blood flow volume. Specifically, for example, the pulse wave amplitude normalization unit 140 normalizes the average value of the pulse wave amplitude in a predetermined period with the average value of the blood flow volume in the predetermined period.

  The output unit 150 outputs information on the normalized pulse wave amplitude calculated by the pulse wave amplitude normalization unit 140 as normalization information. The alarm unit 160 issues an alarm based on the output normalization information.

  The “blood flow” calculated by the blood flow calculation unit 120 is not limited to the blood flow itself, and is a concept including a physical quantity or a parameter that changes according to the blood flow. Similarly, the “pulse wave amplitude” calculated by the pulse wave amplitude calculation unit 130 is not limited to the pulse wave amplitude itself, and is a concept including a physical quantity or a parameter that changes in accordance with the pulse wave amplitude.

  Next, a biological monitor process performed in the biological monitor system configured as described above will be described with reference to the flowchart of FIG.

  In FIG. 3, first, when blood flow measurement by the blood flow measurement unit 10 is started, the data acquisition unit 110 acquires and records blood flow data (step S101). Next, the control unit 100 determines whether or not a preset time t (for example, 60 seconds) has elapsed (step S102). When it is determined that the time t has not elapsed (step S102: No), the control unit 100 performs the process of step S102 again.

  On the other hand, when it is determined that the time t has elapsed (step S102: Yes), the blood flow rate calculation unit 120 calculates the average value of the blood flow rate from the blood flow data recorded in the period from the time point retroactive by time t to the present time. Is calculated (step S103) (see the upper part of FIG. 4). In parallel with the processing of step S103, the pulse wave amplitude calculation unit 130 calculates the average value of the pulse wave amplitude from the blood flow data recorded in the period from the time point back by time t to the present time (step S104). (See the middle part of FIG. 4).

  Next, the pulse wave amplitude normalization unit 140 normalizes the average value of the pulse wave amplitude with the average value of the blood flow, and information Norm (t) regarding the normalized pulse wave amplitude (corresponding to “normalized information”) ) Is calculated (step S105) (see the lower part of FIG. 4). As a calculation method of “Norm (t)”, for example, “pulse wave amplitude / blood flow volume”, “pulse wave amplitude / (blood flow volume + pulse wave amplitude / 2)”, “pulse wave amplitude / (blood flow volume + constant). ) "And the like, but are not limited to these formulas.

  Next, the control unit 100 compares “Norm (t)” output from the output unit 150 this time with “Norm (t−α)” already output (here, “Norm (t) ) / Norm (t−α) ”) and the comparison result (here, the fluctuation amount) is determined to be larger than a predetermined threshold value such as 20% (step S106).

  Note that “α” is appropriately set by the user of the biological monitor system according to changes in the target and the living body. For example, if the change of the living body in a relatively short period is targeted, “α = 10 seconds” or the like is set. For example, if the change of the living body in a relatively long period is targeted, “α = 600 seconds "etc. The “predetermined threshold value” may be set as appropriate in relation to “α”, for example.

  When it is determined that the comparison result is greater than the predetermined threshold value (step S106: Yes), the alarm unit 160 issues an alarm, for example, by emitting a warning sound or blinking light (step S107).

  When it is determined that the comparison result is equal to or smaller than the predetermined threshold value (step S106: No), or after the process of step S107, the control unit 100 determines whether the measurement is finished (step S108). When it is determined that the measurement is not finished (step S108: No), the control unit 100 performs the process of step S102.

  On the other hand, when it is determined that the measurement is ended by detecting that a predetermined operation button of the biological monitor system is pressed or the like (step S108: Yes), the control unit 100 ends the biological monitor process.

  Here, a description will be added with reference to FIG. FIG. 4 is an example of a blood flow data waveform, a blood flow volume, a pulse wave amplitude, and a pulse wave amplitude after normalization.

  As described above, the blood flow data waveform (see the upper part of FIG. 4) includes a component caused by blood flow (“blood flow” in FIG. 4), a component caused by heartbeat (“pulse wave amplitude” in FIG. 4), Is included. In addition, the blood flow data waveform is affected by biological fluctuations such as respiration of the living body, autonomic nerves, and vasomotion. In the presence of biological fluctuations, it has been found by the inventor's research that the components caused by blood flow and the components caused by heartbeat are similarly affected by the biological fluctuations.

  For this reason, for example, sudden changes in the physical condition of the living body can be made only by the blood flow volume obtained from the blood flow data waveform (see the dotted line in the upper part of FIG. 4) or only by the pulse wave amplitude obtained from the blood flow data waveform (see the middle part of FIG. May be detected erroneously even though the physical condition of the living body has not changed (deteriorated) due to the fluctuation of the living body.

  However, in the present embodiment, the pulse wave amplitude normalization unit 140 normalizes the pulse wave amplitude with the blood flow volume (“pulse wave amplitude / blood flow volume” in FIG. 4), thereby reducing or canceling the influence of biological fluctuations. (See the lower part of FIG. 4). Therefore, based on the normalized pulse wave amplitude (that is, “normalized information”), for example, a sudden change in the physical condition of a living body can be appropriately detected.

  The “control unit 100”, the “data acquisition unit 110”, the “pulse wave amplitude normalization unit 140”, the “output unit 150”, and the “alarm unit 160” according to the present embodiment are respectively “biological information” according to the present invention. It is an example of “output device”, “acquisition means”, “normalization means”, “output means”, and “alarm means”.

<Second embodiment>
A second embodiment of the biological information output apparatus of the present invention will be described with reference to FIGS. The second embodiment is the same as the configuration of the first embodiment except that the configuration of the biological monitor system is partially different. Therefore, the description overlapping with that of the first embodiment is omitted, and the same place on the drawing is not shown. The second embodiment will be described with reference to FIG. 5 and FIG. 6 only for parts that are basically different from the first embodiment. FIG. 5 is a block diagram showing the configuration of the biological monitor system according to the second embodiment. FIG. 6 is a flowchart showing a main part of the biological monitor process according to the second embodiment.

  In FIG. 5, the living body monitor system according to the present embodiment includes a blood flow measurement unit 10 and a control unit 101.

  As another example of the “biological information output device” according to the present invention, the control unit 101 includes a data acquisition unit 110, a blood flow rate calculation unit 120, a pulse wave amplitude calculation unit 130, a pulse wave amplitude normalization unit 140, and an output unit. 150, an alarm unit 160, and a heartbeat detection unit 170.

  The heartbeat detection unit 170 detects the heartbeat of the living body based on the blood flow data acquired by the data acquisition unit 110. It should be noted that various known modes can be applied to the heart rate detection unit 170, and thus the detailed description thereof is omitted. The heartbeat detection unit 170 may be a separate component from the control unit 101, such as an electrocardiograph, instead of being part of the control unit 101.

  Next, a biological monitor process performed in the biological monitor system configured as described above will be described with reference to the flowchart of FIG.

  In FIG. 6, after the process of step S <b> 101 described in the first embodiment (see FIG. 3), the heartbeat detection unit 170 is based on the blood flow data acquired by the data acquisition unit 110 for one heartbeat of the living body. It is determined whether or not blood flow data has been acquired (step S201).

  When it is determined that blood flow data for one heartbeat is not acquired (step S201: No), the heartbeat detection unit 170 performs the process of step S201 again.

  On the other hand, when it is determined that blood flow data for one heartbeat has been acquired (step S201: Yes), the blood flow calculation unit 120 calculates the blood flow from the blood flow data recorded for the period of one heartbeat. An average value is calculated (step S202). In parallel with the process of step S202, the pulse wave amplitude calculation unit 130 calculates the pulse wave amplitude from the blood flow data recorded during the period of one heartbeat (step S203).

  Next, the process of step S105 described in the first embodiment (see FIG. 3) is performed.

<Third embodiment>
A third embodiment of the biological information output apparatus of the present invention will be described with reference to FIG. The third embodiment is the same as the configuration of the first embodiment except that the configuration of the biological monitor system is partially different. Therefore, the description overlapping with that of the first embodiment is omitted, and the same place on the drawing is not shown. Only the parts different from the first embodiment will be described with reference to FIG. 7 for the third embodiment. FIG. 7 is a block diagram showing the configuration of the biological monitor system according to the third embodiment.

  The living body monitor system according to the present embodiment includes a laser Doppler blood flow meter 10a and a control unit 100.

  The laser Doppler blood flow meter 10 a includes a laser unit 11, a light receiving element 12, an amplifier 13, an analog-digital converter 14, and a blood flow calculation unit 15.

  The laser light irradiated to the living body from the laser unit 11 is scattered by the blood flow in the capillary of the living body, that is, the red blood cells moving in the blood. The light receiving element 12 receives scattered light scattered by red blood cells and reflected light from a skin tissue or the like of a living body.

  Here, in the scattered light, the frequency of the light changes due to the laser Doppler action corresponding to the moving speed of the red blood cells that are the scatterers. On the other hand, the frequency does not change in the reflected light. As a result, the scattered light incident on the light receiving element 12 and the reflected light interfere with each other to generate beat signal light (that is, light resulting from the difference between the frequency of the scattered light and the frequency of the reflected light).

  The light receiving element 12 outputs a detection current corresponding to the beat signal light. For example, the amplifier 13 including a transimpedance amplifier converts the output detection current into a voltage and amplifies it. The analog-digital converter 14 quantizes the output of the amplifier 13 and outputs a sample value corresponding to the beat signal light.

  The output sample value is buffered in a memory (not shown), and the blood flow calculation unit 15 performs frequency analysis by FFT. The blood flow calculation unit 15 calculates the blood flow data amount using the result of frequency analysis by FFT and outputs the blood flow data amount to the control unit 100. In FIG. 7, the control unit 100 includes the blood flow rate calculation unit 120 that calculates the average value of the blood flow rate. However, the laser Doppler blood flow meter 10 a may calculate the average value of the blood flow rate.

  If comprised in this way, a blood flow can be measured non-invasively and easily, and it is very advantageous practically. In addition, the structure of the laser Doppler blood flow meter 10a is not restricted to the above-mentioned structure, Various well-known aspects are applicable.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the scope or spirit of the invention that can be read from the claims and the entire specification. Apparatuses and methods, and computer programs are also included in the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 10 ... Blood flow measurement part, 10a ... Laser Doppler blood flow meter, 100, 101 ... Control part, 110 ... Data acquisition part, 120 ... Blood flow volume calculation part, 130 ... Pulse wave amplitude calculation part, 140 ... Pulse wave amplitude normalization 150, output unit, 160 ... alarm unit, 170 ... heart rate detection unit

Claims (9)

An acquisition means for acquiring blood flow data which is data relating to blood flow of a living body;
Normalization means for normalizing an amplitude component that is a component related to a fluctuation amplitude included in the acquired blood flow data by a blood flow component that is a component related to a blood flow included in the acquired blood flow data;
Output means for outputting normalized information which is information relating to the normalized amplitude component;
A biological information output device comprising:   The biological information output apparatus according to claim 1, wherein the normalizing unit normalizes the average value of the amplitude component in the predetermined period using an average value of the blood flow component in the predetermined period.   The biometric information output according to claim 2, wherein the normalizing means normalizes the average value of the amplitude component by dividing the average value of the amplitude component by the average value of the blood flow component. apparatus.   The normalization unit normalizes the amplitude component in the period using an average value of the blood flow component in a period corresponding to one heartbeat of the living body. Biological information output device.   5. The biological information output apparatus according to claim 4, wherein the normalizing unit normalizes the amplitude component by dividing a value indicating the amplitude component by an average value of the blood flow component.   6. The biological information output apparatus according to claim 1, further comprising alarm means for issuing an alarm in accordance with a comparison result between the output normalized information and a predetermined threshold value. An acquisition step of acquiring blood flow data, which is data relating to blood flow of a living body;
A normalization step of normalizing an amplitude component that is a component related to a fluctuation amplitude included in the acquired blood flow data by a blood flow component that is a component related to a blood flow included in the acquired blood flow data;
An output step of outputting normalization information that is information on the normalized amplitude component;
A biological information output method comprising: A computer installed in the biological information output device
An acquisition means for acquiring blood flow data which is data relating to blood flow of a living body;
Normalization means for normalizing an amplitude component that is a component related to a fluctuation amplitude included in the acquired blood flow data by a blood flow component that is a component related to a blood flow included in the acquired blood flow data;
Output means for outputting normalized information which is information relating to the normalized amplitude component;
A computer program that functions as a computer program.   A recording medium in which the computer program according to claim 8 is stored.