JP2012179210A - Pulse wave measuring apparatus and method of measuring pulse wave - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulse wave measuring apparatus for determining the blood perfusion from the body motion of a subject, and measuring a pulse wave in consideration of conditions of a living body other than the pulse and the depth of a measuring object in the living body.SOLUTION: The pulse wave measuring apparatus includes: an acceleration measuring unit which detects an acceleration caused according to an external force, and outputs an acceleration signal that shows the acceleration in a site provided as a measurement site in the subject's body; an oscillating unit which transmits the pulsation to the inside of the body in the measurement site to give vibration different from the pulsation of the heart to a blood vessel in the body; and a biosensor unit which irradiates light from a body surface in the measurement site toward the blood vessel, in a condition that the vibration is given to the blood vessel in the body by the oscillating unit, to detect a plethysmogram based on the transmitted light or reflection light.

Description

  The present invention relates to a pulse wave measuring apparatus and a pulse wave measuring method for measuring a photoelectric volume pulse wave.

  There are various medical devices for grasping the state of a living body. One of the methods for non-invasively grasping the state of a living body is a method for measuring a numerical value related to a circulatory function. For example, there is a pulse wave measuring device that measures a pulse wave by irradiating light from the skin surface of a living body, receiving transmitted light or reflected light, and detecting blood flowing through a blood vessel. Such a pulse wave measuring device differentiates the value of the detected pulse wave, for example, and calculates an acceleration pulse wave which is one of the circulation dynamics. The obtained acceleration pulse wave is used to grasp the state of the living body. For example, the state of a living body is grasped by evaluating vascular elasticity characteristics.

  As the above measuring device, for example, an acceleration pulse wave measuring device using an ultrasonic wave and a photoelectric volume pulse wave is considered (see Patent Document 1). This acceleration pulse wave measuring device detects the blood flow velocity using the first circulation sensor means (ultrasonic wave or laser), and uses the second circulation sensor means (light such as laser or LED (Light Emitting Diode)). It has a function of detecting a photoelectric pulse signal, measuring circulation information from the blood flow velocity, and correcting the measurement conditions to be the same.

JP 2003-275184 A

  However, since the beat of the living body varies depending on the mental state, the state before and after the exercise, and the like, when measuring the pulse wave, a measurement result affected by the beat is obtained. Then, depending on the state of mind, before and after exercise, the pulse wave that is the measurement result varies, and the elastic characteristics of the blood vessel obtained from the pulse wave are also affected. In addition, the degree of tension or relaxation of the blood vessels varies depending on the warmth or cold felt by the living body, which may affect the measurement results. Therefore, it is desirable to obtain the elastic characteristics of blood vessels other than the heartbeat function of the heart. In addition, when the light emitted toward the inside of the living body is a single type, the depth of the arrival of the light is constant, so that measurement / diagnosis tends to be one-sided. Furthermore, the blood flow (hereinafter referred to as blood perfusion) varies from subject to subject depending on the subject's constitution, and local blood perfusion at the measurement site is also affected by gravity, thus affecting the elasticity of blood vessels. It will also be a thing.

  The present invention has been made in view of such circumstances, and its purpose is to consider the state of pulse waves in consideration of the state other than the heartbeat of the living body, the depth in the living body to be measured, and the influence of blood flow perfusion due to gravity. The object is to provide a pulse wave measuring device and a pulse wave measuring method for performing measurement.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 The pulse wave measurement device according to this application example detects acceleration generated according to an external force, and outputs an acceleration signal representing the acceleration at a site determined as a measurement site in the body of the subject. A measurement unit, a vibration applying unit that transmits a wave to the body of the measurement site and applying a vibration different from a heart beat to the blood vessel in the body, and the vibration applying unit applies the vibration to the blood vessel in the body. And a biological sensor unit that irradiates light from the body surface of the measurement site toward the blood vessel and detects a volume pulse wave based on the transmitted light or reflected light.

  Application Example 2 In the pulse wave measurement device according to the application example described above, the acceleration measuring unit decomposes and detects the acceleration generated according to the external force into three axial components orthogonal to each other. The direction of gravity acting on the measurement site and the effect thereof is attached to the measurement site or in the vicinity of the measurement site and specified by analyzing the acceleration signal, and the measurement result is taken into account It is characterized in that it is determined whether there is body movement for the subject when an acceleration signal indicating that acceleration has occurred in addition to gravitational acceleration is received from the acceleration measuring unit.

  According to the pulse wave measuring devices described in Application Example 1 and Application Example 2 described above, a wave that vibrates a blood vessel in the body is transmitted, and a volume pulse wave corresponding to the state of the blood vessel affected by the wave is transmitted to the living body. Since it is detected by the sensor unit, it is possible to grasp the behavior of the blood vessel to which vibration different from the heart beat is given, and further, the direction of gravity that affects blood perfusion at the measurement site by acceleration measurement and You can analyze the size and add the result. As a result, it is possible to accurately grasp the state of the blood vessel due to the influence of blood perfusion and obtain new data that can be used as an analysis target regarding the elastic characteristics of the blood vessel.

Application Example 3 In the pulse wave measurement device according to the application example described above, the biological sensor unit includes a plurality of types having different principal wavelengths in a state where the vibration is applied to the blood vessel in the body by the vibration applying unit. Of the light, one type of selected light is emitted from the body surface toward the blood vessel, and a volume pulse wave is detected based on the transmitted light or reflected light.

  Application Example 4 In the pulse wave measurement device according to the application example described above, the biological sensor unit emits a plurality of types of light having different principal wavelengths in a state where the vibration is applied to the blood vessel by the vibration applying unit. Irradiating toward the blood vessel from the body surface, volume pulse waves corresponding to each of the plurality of types of light are detected based on the transmitted light or reflected light.

  According to the pulse wave measurement device described in Application Example 3 and Application Example 4 above, the selected one type of light or the plurality of types of light among a plurality of types of light having different main wavelengths is emitted. It is possible to analyze the behavior of each of the arterial blood vessels and venous blood vessels by utilizing the reaction to the blood components contained in the arterial blood and venous blood, for each depth of the target tissue in the living body.

  Application Example 5 In the pulse wave measurement device according to the application example described above, the biological sensor unit detects the volume pulse wave in a state where the vibration is not applied in addition to the state where the vibration is applied. The vibration applying unit applies vibration according to the volume pulse wave detected by the biological sensor unit in a state where the vibration is not applied to the blood vessel in the body by the vibration applying unit. Features.

  According to the pulse wave measurement device described in Application Example 5 described above, a volume pulse wave corresponding to the state of the blood vessel is detected by the biological sensor unit without transmitting a wave that vibrates the blood vessel in the body, and the volume pulse wave is detected. Since the corresponding vibration is applied by the vibration applying unit, the behavior of the blood vessel corresponding to the expanded state and the contracted state of the blood vessel is grasped, and thereby new analysis data can be obtained.

  Application Example 6 In the pulse wave measurement device according to the application example described above, the pulse wave measurement device includes a reception unit that receives electrocardiogram data output from the electrocardiogram monitor device, and the vibration applying unit includes an electrocardiogram data received by the reception unit. The vibration is applied to the blood vessel at a time delayed by a predetermined time from the detection time of the R wave.

  According to the pulse wave measurement device described in Application Example 6 above, since the vibration applying unit applies vibration according to the electrocardiogram data output from the electrocardiogram monitoring device, the blood vessel behavior according to the dilated state and the contracted state of the blood vessel. As a result, it becomes possible to obtain new analysis data.

  [Application Example 7] In the pulse wave measurement method according to this application example, blood perfusion that is affected by gravity is determined by the direction and magnitude of acceleration acting on the measurement site, and light is directed from the body surface toward the blood vessel in the body. Irradiates and detects a volume pulse wave based on the transmitted or reflected light, transmits a wave according to the detected volume pulse wave to the body, and differs from the heart beat to the blood vessel in the body A vibration pulse is applied, and the volume pulse wave of the blood vessel in the body is detected when the wave is transmitted in consideration of blood perfusion of the subject.

  In this way, the influence of blood perfusion at the measurement site can be analyzed by the acceleration measuring unit, and the energy wave can be transmitted to the body of the subject by the vibration applying unit to detect the change in the kinetics of the blood vessel using the photoelectric pulse wave. As a result, it is possible to perform measurement that does not depend on the beat of the living body while capturing changes in the blood vessel state, and it is possible to obtain data on the elastic characteristics of the blood vessel more accurately.

It is a figure which shows an example of the external appearance of the pulse-wave measuring apparatus 1 of 1st Embodiment of this invention. It is a figure which shows an example of the mounting | wearing aspect of the sensor part 30 of the pulse wave measuring device. 2 is a schematic block diagram showing a configuration of the pulse wave measurement device 1. FIG. It is a figure explaining the relationship between a fingertip volume pulse wave and an acceleration pulse wave. It is a figure explaining the relationship between a fingertip volume pulse wave and an acceleration pulse wave. It is a figure explaining a synchronous timing. It is a figure which shows the waveform showing each volume pulse wave in each when the wave is not given by the wave part, and when this wave is given. It is a figure which shows an example of a posture with good blood perfusion, and a posture with bad blood perfusion. It is a figure showing the relationship between the quality of blood perfusion and the signal strength of a pulse wave signal. It is a figure showing the structure of the pulse-wave measuring apparatus 1a which concerns on 2nd Embodiment of this invention. It is a figure for demonstrating the main wavelength of the light which two light emission parts each irradiate, and the depth by which the light reaches | attains the inside of a biological body. It is a figure showing the structure of the pulse-wave measuring apparatus 1b which concerns on 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The embodiments described below do not unduly limit the contents of the present invention described in the claims. Also, not all of the configurations described below are essential constituent requirements of the present invention.

(First embodiment)
FIG. 1 is a diagram illustrating an example of an appearance of a pulse wave measurement device 1 according to the first embodiment of the present invention. The pulse wave measuring device 1a according to the second embodiment to be described later and the pulse wave measuring device 1b according to the third embodiment mobile phone can have the same configuration.
As shown in FIG. 1, the pulse wave measuring device 1 has a wristwatch structure, a device main body 10 to be attached to the wrist of a subject, and a sensor unit 30 connected to the device main body 10 via a cable 20. And have. As shown in FIG. 1, a wristband 12 is attached to the apparatus main body 10. The pulse wave measuring device 1 is worn on the subject's body by winding the wristband 12 around the subject's wrist (left wrist in the example shown in FIG. 1). A display unit 14 such as a liquid crystal display is provided on the surface of the apparatus body 10. The display unit 14 displays biological information such as the elastic characteristics of the blood vessel, the calculated pulse interval, and the pulse rate per unit time as an analysis target from the pulse wave signal detected by the sensor unit 30. A button switch 16 is provided on the outer periphery of the apparatus body 10. The button switch 16 is used for inputting various instructions such as measurement start and measurement end of the pulse wave measuring device, reset of the measurement result, and the like.

FIG. 2 is a diagram illustrating an example of how the sensor unit 30 is attached to the body of the subject.
As shown in FIG. 2, the sensor unit 30 includes a biological sensor 32 and a sensor fixing band 34. The sensor unit 30 is attached to the subject's body by, for example, winding a sensor fixing band 34 around a portion (hereinafter, a measurement site) between the base of the left index finger of the subject and the second finger joint. In a state where the sensor unit 30 is attached to the body of the subject, the biosensor 32 is shielded from external light by the sensor fixing band 34. This is to eliminate noise caused by external light. In the present embodiment, the case where the sensor unit 30 is attached to the left index finger of the subject will be described, but it may of course be attached to another finger such as the middle finger or the ring finger of the left hand. As shown in FIG. 1, in the first embodiment, the apparatus main body 10 is attached to the left arm of the subject. However, the apparatus main body 10 may be attached to the right arm. In this case, the sensor unit 30 is attached to the finger of the right hand. Should be installed. Furthermore, in the present embodiment, the measurement site has been described with respect to the left hand finger and the right hand finger of the subject. However, if the sensor portion 30 is a measurement site capable of measuring a pulse wave, the analysis target is based on the detected pulse wave signal. It is possible to obtain biological information such as the elastic characteristics of the blood vessels, the pulse interval, and the pulse rate per unit time.
The biological sensor 32 shown in FIG. 2 is a mode in which the light emitted toward the blood vessel from the body surface of the measurement site is a volume pulse wave detected based on the reflected light reflected by the biological tissue such as the blood vessel. Or the aspect which detects a volume pulse wave based on the transmitted light which the light irradiated toward the blood vessel from the body surface of a measurement site | part permeate | transmitted biological tissues, such as a blood vessel, may be sufficient.

Hereinafter, the embodiment of the present invention will be described with an aspect in which volume pulse waves are detected mainly based on reflected light reflected.
FIG. 3 is a schematic block diagram showing the configuration of the pulse wave measuring apparatus 1 according to the first embodiment of the present invention.
The pulse wave measuring device 1 includes a biosensor unit 110, a vibration applying unit 120, a data processing unit 130, and an acceleration measuring unit 140. Here, the electrocardiogram monitor device 2 can also be connected to the outside.

  The biosensor unit 110 includes a light emitting unit 111, a driving unit 112, a light receiving unit 113, and an amplifying unit 114. The light emitting unit 111 emits light from the body surface of the living body toward the inside of the body by emitting light. The driving unit 112 causes the light emitting unit 111 to emit light based on a control signal from the data processing unit 130. The light receiving unit 113 detects light emitted from the light emitting unit 111 and reflected by the living body. The amplifying unit 114 amplifies the detection result from the light receiving unit 113. For example, an electrical signal representing the detection result is amplified and output to the pulse wave processing unit 131.

  The vibration applying unit 120 includes a vibration oscillating unit 121, a wave transmitting unit 122, and a wave unit 123. The vibration oscillating unit 121 outputs a signal for vibration oscillation to the wave transmitting unit 122 based on an instruction from the data processing unit 130. Based on the volume pulse wave detected by the pulse wave processing unit 131, the vibration oscillating unit 121 generates a control signal that gives a vibration different from the pulsation of the heart and outputs the control signal to the wave transmission unit 122.

  Further, when the electrocardiogram monitor device 2 is not connected to the outside, the vibration oscillating unit 121 detects the peak value (or bottom value) of the volume pulse wave signal and is determined in advance from the time corresponding to the value. The control signal for transmitting the wave to the wave unit 123 is generated by delaying the time.

On the other hand, when the electrocardiogram monitor device 2 is connected to the outside, the vibration oscillating unit 121 delays a predetermined time from the electrocardiogram data received by the data calculation unit 132, for example, the R wave, and the wave unit A control signal for causing 123 to transmit a wave is generated.
The wave transmission unit 122 sends the control signal generated by the vibration oscillation unit 121 to the wave unit 123 to drive the wave unit 123. In response to the control signal, the wave unit 123 transmits a wave for applying vibration to the blood vessel in the body toward the body. This wave is, for example, a sound wave.

The data processing unit 130 includes a pulse wave processing unit 131 and a data calculation unit 132.
The pulse wave processing unit 131 detects the volume pulse wave when the vibration is given to the blood vessel by the wave unit 123 by the light receiving unit 113.
The data calculation unit 132 includes a receiving unit that receives electrocardiogram data output from the electrocardiogram monitor device 2 provided outside. In addition, the data calculation unit 132 performs various analysis processes based on the volume pulse wave obtained by the pulse wave processing unit 131 and performs a blood vessel state diagnosis. Here, as an example, a blood vessel state diagnosis is performed using a photoelectric fingertip volume pulse wave.

  Here, an acceleration pulse wave is used in the photoelectric fingertip volume pulse wave. The acceleration pulse wave is a second derivative of photoplethysmogram (SPTTG) of a photoelectric fingertip volume pulse wave (PTG). The acceleration pulse wave is used to clarify the inflection point of the fingertip volume pulse wave, which is the original waveform, and the inspection method using the acceleration pulse wave is now established as an independent inspection method. ing. This acceleration pulse wave is advantageous in that it is easy to record, does not take time, and has no pain to the subject. In addition, the interpretation and significance of waveforms are now fully clinically applicable. Here, the acceleration pulse wave is a differential (acceleration) of the fingertip volume pulse wave, which is the original waveform, twice, and is not directly related to the velocity or acceleration of the blood flow.

  FIG. 4 is a diagram for explaining the relationship between the fingertip volume pulse wave and the acceleration pulse wave. FIG. 4A is a diagram illustrating an example of a waveform representing the measurement result of the fingertip volume pulse wave obtained by the biological sensor unit 110. FIG. 4B is a diagram illustrating an example of a velocity pulse wave obtained by differentiating the fingertip volume pulse wave once. FIG.4 (c) is a figure showing an example of the acceleration pulse wave obtained by differentiating the fingertip volume pulse wave twice. The data calculation unit 132 includes a differentiating circuit, performs differentiation twice on the fingertip volume pulse wave obtained by the biosensor unit 110, and obtains an acceleration pulse wave.

FIG. 5 is a diagram for explaining the relationship between the fingertip volume pulse wave and the acceleration pulse wave. FIG. 5A shows an example of the waveform of the fingertip volume pulse wave, and FIG. 5B shows an example of the waveform of the acceleration pulse wave. In FIG. 5A, the vertical axis represents the magnitude of the pulse wave, and the horizontal axis represents time. The section (A) is a section representing the systolic anterior component, and represents a driving pressure wave generated by ejection of blood when the heart contracts. The section (B) is a section representing the backward systolic component, and represents the re-rising pressure wave that the driving pressure has propagated to the periphery, reflected, and returned. A value representing the magnitude of the pulse wave corresponding to the end time of the section (A) is represented by PT ₁ , and a value representing the magnitude of the pulse wave corresponding to the end time of the section (B) is represented by PT ₂ .

  In FIG.5 (b), a vertical axis | shaft represents the magnitude | size of a pulse wave, and a horizontal axis represents time. The acceleration pulse wave illustrated in the figure has five inflection points represented by wave heights a, b, c, d, and e. Regarding the pulse height ratios (b / a, c / a, d / a, e / a) of the acceleration pulse wave, there is no calibration in the strict sense of the wave height component of the acceleration pulse wave. Therefore, for comparison of wave heights, wave height ratios such as b / a, c / a, d / a, and e / a obtained by dividing each waveform component by the value of wave height a, which is a positive initial contraction wave, are used. The pulse height ratio of the acceleration pulse wave changes with aging. It is possible to diagnose the state of the blood vessel from this change. For example, data representing the relationship between the pulse height ratio of the acceleration pulse wave and the age is generated based on past cases and stored as table information, and the age corresponding to the obtained wave height ratio is stored in the table information. Get by referring to. In addition, data representing the relationship between each pulse height ratio of the acceleration pulse wave and the vascular elastic characteristic is generated based on past cases and stored as table information, and the vascular elastic characteristic corresponding to the obtained pulse height ratio is stored. obtain. In this way, the state of the blood vessel is diagnosed.

  Next, the synchronization timing when the electrocardiogram monitor device 2 is connected to the outside will be described with reference to FIG. FIG. 6A shows an electrocardiogram waveform obtained as electrocardiogram data. The vertical axis represents electrocardiogram data values, and the horizontal axis represents time. The vibration oscillation unit 121 detects the peak value of the R wave included in the electrocardiogram waveform, and detects the time of the peak value. Then, the vibration oscillating unit 121 detects a timing (time) delayed from the time by a predetermined time. FIG. 6B is a diagram illustrating the waveform of the volume pulse wave, where the vertical axis represents the value representing the volume pulse wave, and the horizontal axis represents time. In this figure, time t1 is the time from time T0 when the R wave is generated to time T1 when the peak value m of the volume pulse wave is generated. The value of the time t1 varies depending on the distance from the heart to the measurement site of the pulse wave measuring device 1. The vibration oscillating unit 121 stores, in a memory, a time from time T0 to any time between time T0 and time T1 or a time after a predetermined time has elapsed since time T1 arrived. When this time elapses from the time R0 when the R wave is detected, vibration (pulse vibration) is generated.

  FIG.6 (c) is a figure showing the value at the time of differentiating the volume pulse wave shown in FIG.6 (b) twice. The vertical axis represents the value after being differentiated twice, and the horizontal axis represents time. The data calculation unit 132 differentiates the detection result value obtained from the pulse wave processing unit 131 twice to detect the values of the wave heights a, b, c, d, and e.

  FIG. 7 is a diagram showing a waveform representing each volume pulse wave when the wave unit 123 does not give a wave and when the wave is given. The vertical axis represents the volume pulse wave value, and the horizontal axis represents time. The waveform of the volume pulsation wave in the section Ta is a waveform when vibration is not applied from the wave part 123, and the waveform of the volume pulsation wave in the section Tb is a waveform when vibration is applied from the wave part 123. is there. Here, at time T <b> 10, when vibration is applied from the wave unit 123, the volume pulse wave changes as represented by the symbol k. The volume pulse wave in which this change has occurred is detected, and the data calculation unit 132 performs differentiation twice to make a diagnosis.

  A value obtained by differentiating the volume pulse wave when vibration is applied twice is different from a value obtained by differentiating the volume pulse wave when vibration is not applied twice. Collecting data between the relationship between the value differentiated twice in the case where vibration is given and the case where vibration is not given, and the vascular elastic property at each measurement depth, analyze the correlation, and obtain the analysis result. It is stored in advance in a storage device as diagnostic data. Then, the pulse wave measuring device 1 obtains a value obtained by differentiating the volume pulse wave when vibration is not applied and the volume pulse wave when vibration is applied twice, and refers to the diagnostic data, Diagnosis can be made.

  As shown in FIG. 7, when the pulse wave measuring device 1 measures a volume pulse wave when no vibration is applied, the vibration applying unit 120 of the pulse wave measuring device 1 responds to the next heartbeat. A vibration may be applied to the pulsation of the heart to perform diagnosis from these two measurement results. In this way, by making a diagnosis by using continuous heart beats, it is possible to perform measurement while reducing fluctuations in the beats caused by mental fluctuations, differences in temperature, and the like experienced by the living body.

  Returning to FIG. The acceleration measurement unit 140 detects the presence or absence of body movement of the subject and the gravity at the measurement site that affects blood perfusion, and outputs a value corresponding to the gravity to the data processing unit 130. For example, the acceleration generated according to the external force is detected by decomposing it into components in directions of three axes (x, y and z axes) orthogonal to each other, and an acceleration signal AS indicating the magnitude of each component is output. As an example, the acceleration measuring unit 140 includes the sensor unit shown in FIG. 1 such that the x axis coincides with the extending direction of the sensor fixing band 34 in FIG. 1 and the y axis coincides with the direction indicated by the index finger in FIG. 30.

For this reason, when the subject wearing the pulse wave measuring device 1 on the left arm in a manner as shown in FIG. 1 is stationary with the left arm hanging vertically, the acceleration measuring unit 140 is gravity-induced in the y-axis direction. An acceleration signal AS indicating that is added is output. In addition, when the subject is stationary with the left arm pointing up with the left arm pointing up, the acceleration measurement unit 140 is subject to gravity in the x-axis direction. Is output. When receiving an acceleration signal indicating that acceleration other than gravitational acceleration is working, the data processing unit 130 can also determine that there is body movement.
In other words, in this embodiment, the acceleration measuring unit 140 can identify the direction of gravity acceleration with respect to the three axes of xyz by analyzing the acceleration signal AS.

  FIG. 8 shows a posture with good blood perfusion at the measurement site (in the example shown in FIG. 8, a posture in which the left arm is horizontally extended to the same height as the shoulder) and a posture with poor blood perfusion (in the example shown in FIG. 8). FIG. 3 is a view showing an example of a posture in which the left arm is hung vertically. When the posture of the subject changes from a posture with good blood perfusion to a posture with poor blood perfusion, blood accumulates in the left hand peripheral portion (that is, the left fingertip) due to the influence of gravity, thereby changing blood perfusion in the peripheral portion. In other words, “poor blood perfusion” refers to a state where blood accumulates in the peripheral portion and blood flow is inhibited by congestion of living tissue, etc., and “the state where blood perfusion is good” refers to the peripheral portion. The blood is not accumulated and the blood is flowing smoothly.

  FIG. 9 shows the pulse of the photoelectric conversion method when the posture is changed from the posture in which the left index finger is a measurement site and the left arm is horizontally extended to the same height as the shoulder to the posture in which the left arm is vertically hung. It is a figure which shows an example of the change of the pulse intensity measured by the wave measurement (the difference in level between the valley and the peak of the waveform of the pulse wave signal: hereinafter, the bottom-peak interval). As shown in FIG. 9, when the posture is changed from a posture in which the left arm is horizontally extended to the same height as the shoulder to a posture in which the arm is vertically suspended, the bottom-peak interval of the pulse wave signal is gradually reduced. When the value drops to a certain value, it no longer changes. The peak-to-bottom interval of the pulse wave signal gradually decreases after the posture is changed to the posture where the arm is hung vertically. The amount of light irradiated from the light emitting element increases as the amount of blood staying at the measurement site increases. This is because the reflected light is increased. Further, the reason why the bottom-peak interval of the pulse wave signal does not change after it has decreased to a certain value is that there is an upper limit on the amount of blood staying at the measurement site.

  As shown in FIG. 9, the influence of gravity on blood perfusion appears as a change in the bottom-peak interval of the pulse wave signal, but the magnitude of the influence of gravity on blood perfusion varies among individuals. Specifically, some people have a large fluctuation width of the peak / bottom interval of the pulse wave signal in a state where the blood perfusion is good and bad, and some people have a small fluctuation width. In general, blood perfusion is better and worse than healthy people in people with strong muscles such as those with cold muscles such as those with cold or those with advanced arteriosclerosis In many cases, the fluctuation range of the pulse strength at and is small.

  Thus, by specifying the direction of gravitational acceleration by the acceleration measuring unit 140, it is possible to grasp the magnitude of the influence of gravity on the blood perfusion at the measurement site and the blood retention state, and also whether the blood perfusion is good or bad Can be analyzed from the pulse intensity. Therefore, the pulse wave measuring device 1 of the present embodiment has a function of giving a vibration different from the above-described heart beat and a function of appropriately selecting a plurality of types of light while accurately grasping the state change of the subject. Therefore, it is possible to obtain various biological information. In particular, it is possible to acquire new data such as the elastic characteristics of blood vessels in a state where blood is accumulated in arterial blood vessels and venous blood vessels and blood perfusion is poor.

FIG. 10 is a schematic block diagram showing the configuration of the pulse wave measuring device 1a according to the second embodiment of the present invention. The parts corresponding to those in FIG. 3 are denoted by the same reference numerals, and different parts from the configuration of the pulse wave measuring apparatus 1 according to the first embodiment will be described. In the second embodiment, the pulse wave measuring device 1a includes a biological sensor unit 110a and an operation unit 150.
The biosensor unit 110a includes light emitting units 111a and 111b (hereinafter, collectively referred to as “light emitting unit 111” unless otherwise required), a driving unit 112, a light receiving unit 113, and an amplifying unit. 114. The light emitting units 111a and 111b emit light to emit light having different principal wavelengths from the body surface of the living body toward the body.

  FIG. 11 is a diagram for explaining the dominant wavelength of light emitted by the light emitting unit 111a and the light emitting unit 111b and the depth at which the light reaches the inside of the living body. A region called a capillary bed in which capillaries lie exists in a portion close to the body surface of a living body such as a human, that is, in a shallow portion of a living tissue. On the other hand, in a portion far from the body surface, that is, a deep portion of a living tissue, there is a region called a blood vessel bed on which a fibrillation vein, an arteriovenous anastomosis, etc. lie. A capillary blood vessel is the thinnest blood vessel in a mesh shape that connects an artery and a vein. The fibrillation veins are arterioles and venules. The arterioles are the portions of the arteries that are connected to the veins via capillaries. The venules are the arteries of the veins via capillaries. It is the part connected to An arteriovenous anastomosis is an arterial eradication that directly follows a vein without going through capillaries. That is, the arteriovenous anastomosis functions as a bypass that bypasses the capillaries.

  The pulse wave in the capillary bed and the pulse wave in the vascular bed may be different. In particular, in a region where there is an arteriovenous anastomosis, each pulse wave may differ depending on the state of the arteriovenous anastomosis. Therefore, by measuring and analyzing the pulse wave in the capillary bed and the pulse wave in the blood vessel bed, information indicating the ratio of blood flowing into the arteriovenous anastomosis and the state of the arteriovenous anastomosis such as changes in blood flow is obtained. can do.

  The main wavelength of light refers to the wavelength of the most contained light among the light. As the main wavelength of light is longer, the light tends to reach a deep part of living tissue and be reflected at that part. For example, the dominant wavelength of the light emitted from the light emitting unit 111a is longer than the dominant wavelength of the light emitted from the light emitting unit 111b. Each light emitting unit 111 is designed such that light emitted from the light emitting unit 111b is reflected by the capillary blood vessel bed and light emitted from the light emitting unit 111a is reflected by the blood vessel bed.

  Furthermore, an arterial blood oxygen saturation measuring device is generally known as a medical device that obtains biological information by irradiating multiple types of light. The arterial oxygen saturation meter uses two types of light, red and infrared, to display the percentage of oxygenated hemoglobin linked to oxygen out of hemoglobin in arterial blood, and this is expressed as arterial oxygen saturation. Say. That is, oxygen essential for physical activity combines with hemoglobin in red blood cells to form oxyhemoglobin, and is transported to each organ throughout the body and supplied to cells in each organ. Approximately 100 ml of blood contains 20.4 ml of oxygen as oxyhemoglobin.

  The detailed derivation principle of oxygen saturation is left to the public information such as literature, but it is measured using the difference in spectral absorption characteristics between oxygenated hemoglobin bound to oxygen and reduced hemoglobin released oxygen. Yes. Here, the spectral absorption characteristic is a property indicating which color has a characteristic to absorb well. Oxyhemoglobin absorbs light near infrared rays well, and reduced hemoglobin has a feature of absorbing light near red. The transmitted light or reflected light at these two wavelengths is measured, and the ratio of the two types of hemoglobin is determined from the ratio of the transmitted light of red light and infrared light or the ratio of the reflected light.

  Light irradiated to the living body is absorbed or reflected by tissues such as arterial blood layer and venous blood layer, but tissues other than arteries have no temporal fluctuation (fluctuation of light absorption or light reflection). . For this reason, the arterial blood oxygen saturation measuring device obtains the ratio of two types of hemoglobin from the temporal intensity change according to the arterial volume change due to pulsation. That is, the oxygen saturation is measured from only the information on arterial blood by looking only at the fluctuation component of the transmitted light or the fluctuation component of the reflected light.

In the pulse wave measuring device 1a of the present embodiment, a case where light near red and light near infrared are used as the light emitting portions 111a and 111b of the biosensor portion 110a shown in FIG. 10 will be described as an example.
In the present embodiment, the function of applying vibration from the vibration applying unit 120 shown in FIG. 10 can be used to give temporal variation to the venous blood layer tissue that does not change temporally in the same manner as the arterial blood layer. it can. At this time, by irradiating light in the vicinity of red of the biosensor unit 110a, the reduced hemoglobin that is abundant in venous blood is well absorbed, and the obtained signal contains a lot of information on venous blood vessels. In addition, by irradiating light in the vicinity of the infrared rays of the biosensor unit 110a, oxygenated hemoglobin that is abundant in arterial blood is well absorbed, and the obtained signal contains a lot of information on arterial blood vessels. In this way, by appropriately selecting a plurality of types of light, it is possible to perform a blood vessel state diagnosis for each of arterial blood vessels and venous blood vessels. Furthermore, by specifying the direction and magnitude of the gravitational acceleration by the acceleration measuring unit 140 shown in FIG. 10, the magnitude of the influence of gravity on the blood perfusion at the measurement site and the staying state of the blood are grasped, and the blood perfusion is in a good state New data such as the elastic characteristics of arterial blood vessels and the elastic characteristics of venous blood vessels can be acquired in a state where blood perfusion is poor, and comparison and analysis in each state are possible. For this reason, a more detailed biological state diagnosis can also be performed.

  Returning to FIG. The operation unit 150 includes an operation button (not shown) for selecting either the light emitting unit 111a or the light emitting unit 111b. For example, the operation unit 150 receives an operation by the user and sends an operation signal according to the operation content to the driving unit. 112. The drive unit 112 selects either the light emitting unit 111 a or the light emitting unit 111 b based on the operation signal from the operation unit 150, and causes the selected light emitting unit 111 to emit light based on the control signal from the data processing unit 130. The light receiving unit 113 detects reflected light emitted from the light emitting unit 111 and reflected by the living body. That is, when the light emitting unit 111a is selected by the driving unit 112, the light receiving unit 113 detects reflected light reflected by the blood vessel bed, and when the light emitting unit 111b is selected by the driving unit 112, the light receiving unit 113a receives light. The unit 113 detects the reflected light reflected by the capillary bed. In this manner, the tissue depth (measurement depth) for measuring the pulse wave is selected by the operation signal. In addition, an operation for selecting either the light emitting unit 111 a or the light emitting unit 111 b may have a function that can be selected without using the operation unit 150.

  FIG. 12 is a diagram illustrating a configuration of a pulse wave measurement device 1b according to the third embodiment. The parts corresponding to those in FIG. 10 are denoted by the same reference numerals, and the description thereof is omitted. In the third embodiment, the pulse wave measuring device 1b includes a vibration applying unit 120a instead of the vibration applying unit 120, and includes a data processing unit 130a instead of the data processing unit 130.

  In the vibration applying unit 120a, the receiving unit 124 receives the wave reflected from the blood flowing in the blood vessel. This wave is, for example, light or vibration. The wave amplifying unit 125 amplifies an electric signal representing the result received by the receiving unit 124. In addition to the vibration described in the second embodiment, the wave transmission unit 122 transmits a sound wave having a predetermined frequency to the living body by the wave unit 123.

  In the data processing unit 130 a, the blood flow measurement unit 133 measures the blood flow velocity based on the reception result of the reception unit 124 obtained via the wave amplification unit 125. For example, the Doppler effect of the blood flow is calculated by comparing the frequency of the ultrasonic wave transmitted by the wave transmitting unit 122 with the frequency obtained from the measurement result received by the receiving unit 124. And the blood flow velocity which flows into the blood vessel of the living body is calculated by the change of the frequency, and the time change of the velocity is obtained.

The data calculation unit 132 a corrects the volume pulse wave obtained by the pulse wave processing unit 131 based on the blood velocity obtained by the blood flow measurement unit 133. For example, a value obtained by calculating a value obtained by integrating the waveform of the pulsating component received by the light receiving unit 113 is set as the blood rheology correction coefficient K. Since the maximum blood flow velocity Vmax, which is one of the characteristic components of blood rheology, is correlated with the blood rheology, T is the maximum blood flow velocity Vmax and the blood rheology, where T is an index representing blood rheology. It is represented by the product (Vmax × K) with the correction coefficient K. Based on this equation, the influence of blood vessel tension is corrected. And by performing this correction | amendment, the influence of vascular tone can be reduced and a measurement precision can be improved.
It is also possible to detect the blood flow velocity and determine the state of the energy wave.

  In the second embodiment and the third embodiment described above, the biosensor unit 110a includes the two light emitting units 111a and 111b, but three or more light emitting units that emit light having different principal wavelengths. 111 may be included. In this case, for each main wavelength of the irradiation light irradiated by each light emitting unit 111, the data calculation unit 132 acquires information on the depth of the biological tissue to which the irradiation light is reflected, that is, the measurement depth, and for each measurement depth. A blood vessel state diagnosis may be performed.

  The light emitting unit 111 generates light including a plurality of types of light, and splits the light into a plurality of types of light having different main wavelengths by a spectroscopic unit such as a prism or a filter. You may make it irradiate one type of light. In this case, the driving unit 112 irradiates the selected one type of light by driving the spectroscopic unit of the light emitting unit 111 based on the control signal from the data processing unit 130.

  In addition, the driving unit 112 irradiates one type of light selected from a plurality of types of light having different main wavelengths from either of the light emitting units 111a and 111b. Two or more kinds of light may be irradiated simultaneously. Even when reflected by a living tissue, the dominant wavelength of the reflected light is almost the same as the dominant wavelength of the irradiation light. Therefore, in this case, the light receiving unit 113 only needs to include a spectroscopic unit that splits each light from light including a plurality of types of light having different main wavelengths, that is, for example, a prism. The plurality of types of reflected light corresponding to the plurality of types of irradiation light may be dispersed. The amplifying unit 114 amplifies the detection results of the plurality of types of reflected light that have been dispersed, and individually outputs the detection results to the pulse wave processing unit 131. The pulse wave processing unit 131 individually inputs a plurality of types of detection results detected by the light receiving unit 113 and amplified by the amplification unit 114, detects the volume pulse wave for each of the plurality of types of reflected light, Any one of the detection results may be output to the vibration oscillation unit 121.

  In the above-described embodiment, when the electrocardiogram monitor device 2 is not connected to the outside, the vibration oscillating unit 121 detects the peak value (or bottom value) of the volume pulse wave signal and corresponds to the value. When a control signal for causing the wave unit 123 to transmit a wave is generated at a time (transmission time) obtained by delaying a predetermined time from the time, and the electrocardiogram monitor device 2 is connected to the outside, data Based on the electrocardiogram data received by the arithmetic unit 132, a control signal for delaying a predetermined time from the R wave and causing the wave unit 123 to transmit the wave from the wave transmitting unit 122 is generated. The vibration oscillating unit 121 does not generate a control signal for causing the wave unit 123 to transmit a wave only at the above transmission time, but causes the wave unit 123 to transmit a continuous wave. Control signals may be generated. In this case, the wave unit 123 applies a continuous vibration to a blood vessel in the body instead of the pulse vibration as illustrated in FIG. 7 by transmitting a continuous wave. In short, the vibration applying unit 120 and the vibration applying unit 120a only need to apply vibration to the blood vessels in the body, and the biosensor unit 110 is in a state where vibration is applied to the blood vessels in the body by the vibration applying unit. A plurality of types of light different from each other may be irradiated from the body surface toward the inside of the body, and volume pulse waves corresponding to each of the plurality of types of light may be detected based on each transmitted light or each reflected light.

  In the above-described embodiment, the intensity of vibration applied from the wave unit 123 and the vibration pattern thereof are changed, and the volume pulse wave at each measurement depth in each case is measured to obtain a differential value twice. A diagnosis may be performed from a combination of a plurality of results obtained. For example, the measurement depth is set to two types, capillary bed and vascular bed, the wave intensity is set to two types A10 and A11, and the vibration pattern is set to two types B10 and B11. Then, the volume pulse wave is measured by each of the eight patterns that are combinations thereof, and values obtained by differentiating twice are obtained, and diagnosis may be performed from the correlation of the results of the eight patterns.

  For example, when the first pattern and the second pattern are within the range of the reference value, a diagnosis result is output indicating that the aging degree of the blood vessel is the youngest, or the vascular elastic characteristic is the most elastic characteristic. A diagnosis result indicating that the value is high may be output. This correlation is analyzed in advance and stored in a storage device by performing a number of measurements.

  From the diagnosis results obtained in this way, the cardiovascular system is diagnosed, the degree of aging of the blood vessels and the degree of arteriosclerosis are evaluated, and the rate of blood flowing into the arteriovenous anastomosis and the arteriovenous anastomosis such as blood flow changes It is possible to acquire information indicating the state of

  In the above-described embodiment, the biosensor unit 110 or the biosensor unit 110a detects a volume pulse wave based on the result received by the light receiving unit 113, and the detected volume pulse wave is directly input to the data calculation unit 132. You may make it output. In this case, the biosensor unit 110 may include a pulse wave processing unit 131.

  In the above-described embodiment, the case where the electrocardiogram monitor device 2 is connected to the outside has been described. When the electrocardiogram monitor device 2 is connected, the timing for transmitting the wave can be determined more accurately.

  Further, a program for realizing the functions of the pulse wave measuring device 1, the pulse wave measuring device 1a, and the pulse wave measuring device 1b in FIG. 1 is recorded on a computer-readable recording medium, and the program recorded on the recording medium The volume pulse wave may be detected by causing the computer system to read and execute. Here, the “computer system” includes hardware such as an OS (Operating System) and peripheral devices.

Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW (World Wide Web) system is used.
The “computer-readable recording medium” refers to a storage device such as a flexible disk, a magneto-optical disk, a portable medium such as a ROM (Read Only Memory) and a CD-ROM, and a hard disk incorporated in a computer system. Say. Furthermore, a “computer-readable recording medium” dynamically holds a program for a short time, like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. It also includes those that hold programs for a certain period of time, such as volatile memory inside computer systems that serve as servers and clients in that case. Further, the program may be a program for realizing a part of the above-described functions, and may be a program that can realize the above-described functions in combination with a program already recorded in a computer system. .

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

  DESCRIPTION OF SYMBOLS 1, 1a, 1b ... Pulse wave measuring device, 2 ... Electrocardiogram monitor device, 110, 110a ... Biosensor part, 111, 111a, 111b ... Light emission part, 112 ... Drive part, 113 ... Light receiving part, 114 ... Amplifying part, 120 , 120a ... vibration applying unit, 121 ... vibration oscillating unit, 122 ... wave transmitting unit, 123 ... wave unit, 124 ... receiving unit, 125 ... wave amplifying unit, 130, 130a ... data processing unit, 131 ... pulse wave processing unit, 132, 132a ... data calculation unit, 133 ... blood flow measurement unit, 140 ... acceleration measurement unit, 150 ... operation unit, AS ... acceleration signal.

Claims (7)

An acceleration measuring unit that detects an acceleration generated according to an external force and outputs an acceleration signal representing the acceleration in a part determined as a measurement part in the body of the subject;
A vibration applying unit that transmits a vibration to the body of the measurement site and applies a vibration different from a heart beat to a blood vessel in the body;
In the state where the vibration is applied to the blood vessel in the body by the vibration applying unit, light is emitted from the body surface of the measurement site toward the blood vessel, and the volume pulse wave is detected based on the transmitted light or reflected light. A living body sensor unit,
A pulse wave measuring device comprising: The acceleration measuring unit is a three-axis acceleration sensor that detects an acceleration generated according to an external force by decomposing into three axial components orthogonal to each other, and is attached to the measurement site or the vicinity of the measurement site, The direction of gravity acting on the measurement site and its influence are identified by analyzing the acceleration signal, and the quality of blood perfusion at the measurement site, taking into account the identification result,
In addition to gravitational acceleration, when an acceleration signal indicating that acceleration has occurred is received from the acceleration measuring means, the subject has body movement,
The pulse wave measuring device according to claim 1, wherein:   The biological sensor unit receives one type of light selected from a plurality of types of light having different main wavelengths from the body surface in a state where the vibration is applied to the blood vessel in the body by the vibration applying unit. The pulse wave measuring device according to claim 1, wherein the volume pulse wave is detected based on the transmitted light or reflected light.   The biological sensor unit irradiates a plurality of types of light having different principal wavelengths from the body surface toward the blood vessel in a state where the vibration is applied to the blood vessel by the vibration applying unit, and transmits each transmitted light or each 2. The pulse wave measuring device according to claim 1, wherein a volume pulse wave corresponding to each of the plurality of types of light is detected based on the reflected light.   The biological sensor unit detects the volume pulse wave in a state where the vibration is applied and in a state where the vibration is not applied, and the vibration applying unit is applied to the blood vessel in the body by the vibration applying unit. 2. The pulse wave measuring apparatus according to claim 1, wherein vibration according to the volume pulse wave detected by the biological sensor unit in a state where the vibration is not applied is applied to the blood vessel.   A receiving unit configured to receive electrocardiogram data output from the electrocardiogram monitoring device, wherein the vibration applying unit is configured to perform the vibration at a time delayed by a predetermined time from the detection time of the R wave in the electrocardiogram data received by the receiving unit; The pulse wave measuring device according to claim 1, wherein the pulse wave is applied to the blood vessel. Determine the blood perfusion affected by gravity depending on the magnitude of acceleration acting on the measurement site,
Irradiate light from the body surface toward the blood vessels in the body, detect volume pulse waves based on the transmitted or reflected light,
Sending a wave according to the detected volume pulse wave to the body to give a vibration different from the pulsation of the heart to the blood vessel in the body,
In consideration of blood perfusion of the subject, a volume pulse wave of a blood vessel in the body is detected when the wave is transmitted.

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