JP5101366B2 - Blood component measuring device - Google Patents

Description

  The present invention relates to a blood component measuring device that transmits light from a light projecting unit to a living body, receives light by a light receiving unit, and measures blood components in the living body based on a signal obtained by the light receiving unit.

  Research on irradiating a medium such as light to a medium such as light, and detecting and measuring the electromagnetic wave transmitted through or reflected from the medium in order to determine the characteristics of the components contained in the medium Development has been carried out (for example, see Patent Document 1).

  Such a detection method is more comfortable for the patient because it is performed non-invasively instead of collecting a substance such as blood from the patient's body for examination or inserting a measuring device into the body in the medical field. Therefore, more rapid measurement is possible, which is preferable.

  For example, during surgery, the blood and body's effective oxygen supply, ie blood oxygen saturation, is often monitored. Such measurements use a non-invasive technique that measures and evaluates the transmittance (or reflectance) of transmitted light (or reflected light) through a part of the body, such as a finger or earlobe, or forehead. Often done.

  However, when measuring glucose or the like contained in blood, noise due to other components such as protein and water constituting the living body is larger than signals obtained from the components. Also, most parts of the body, such as finger skin, muscles and blood vessels, are generally soft and easy to deform, and tissues and muscles are easily compressed and deformed by the pressure applied to the fingers when they move. End up.

  Therefore, if light is incident on the finger and the patient moves in such a way that the finger is distorted or compressed, the projecting and receiving portion of the living body will be dissociated. Since the movement of the finger is usually irregular, if the contact state of the contact part changes and dissociation occurs, a new air layer will be interposed, and reflection will occur at the interface with the air, which is expected. Attenuation will occur, making it difficult to interpret the measurement signal.

  Many conventional optical probes are designed to be used only when the patient is relatively stationary because noise induced by movement greatly distorts the measurement signal. In general, the probe has a strong output by maximizing contact between the light source and the medium and between the light detector and the medium and facilitating strong light coupling between the light source, the medium and the light detector. Generate signal strength. In this way, a strong and clear signal is transmitted through the medium when the patient is generally unable to move.

  Moreover, the device which ensures the contact | adherence state of light projection and a light-receiving end part and a biological body is made | formed by pressing a light projection and a light-receiving end part to a biological body mechanically.

  Patent Document 2 describes that a change in signal due to a change in a contact interface is improved by disposing a refractive index matching material such as fluorocarbon at a contact portion with skin.

  Patent Document 3 discloses an optical probe that uses a T-shaped wrap having a vertical axis and a horizontal crossbar to fix a light source and an optical sensor in optical contact with a finger. The light source is arranged in a window on one side of the vertical axis, and the sensor is arranged in a window on the opposite side of the vertical axis. The finger is aligned with this axis, and this axis is folded so that the light source and sensor are placed on opposite sides of the finger. A crossbar is then wrapped around the finger to secure the wrap, thereby providing good light coupling while keeping the light source and sensor in contact with the finger.

  Patent Document 4 describes a probe that allows a probe tip to protrude from a frame so that the tip of the probe can be brought into contact with a measurement site with an appropriate pressure, thereby enabling accurate in-vivo component measurement. .

  Patent Document 5 describes a probe that pressurizes a living body with a cuff to an anemic state and optically measures a blood component. In this probe, measurement is performed based on light of at least two wavelengths, and an optimum pressure is determined for each wavelength. In addition, a first cuff of the measurement portion and a second cuff for making blood bleed on the upstream side thereof are provided.

International Publication No. 03/079900 Pamphlet US Pat. No. 6,622,032 U.S. Pat. No. 4,825,879 JP 2007-89708 A Japanese translation of PCT publication No. 2003-526434 (FIG. 2)

  In the device disclosed in Patent Document 2, even if a refractive index matching material is used for the contact surface, if the amount of the matching material is insufficient or a gap is formed in the contact surface due to the movement of the living body, the interface with the air Reflection occurs and the signal fluctuates greatly. In addition, there is no effect on signal attenuation due to optical axis misalignment between the light projecting unit and the light receiving unit in transmission type absorbance measurement.

  In the above-mentioned device of Patent Document 3, in the fixing with the T-type wrap, if the wrap is loosely tightened, the fixing effect cannot be obtained. On the other hand, if it is too strong, the blood flow is inhibited.

  In the device of Patent Document 4, the fixing method for pressing the probe itself against the living body has problems such as being unable to obtain an effect depending on the pressing force as in the case of the wrap and causing blood flow inhibition.

  The probe disclosed in Patent Document 5 determines an optimum pressure for each wavelength for light of two wavelengths, and is not suitable for measuring a parameter that changes every moment. Further, since the two cuffs are provided and controlled separately, the structure is complicated, and there is no function for aligning the optical axes of the light projecting side and the light receiving side during pressurization.

  The present invention has been made in consideration of such problems, and is a non-invasive blood component measuring apparatus capable of accurately measuring blood components in a living body without being affected by the shape or movement of a measurement target. The purpose is to provide.

  A blood component measurement device according to the present invention is provided on the same optical axis at opposing positions, and a light projecting unit and a light receiving unit into which a living body to be measured can be inserted, and at least one of the light projecting unit and the light receiving unit A slide part for guiding one side along the optical axis; and the light projecting part and / or the light receiving part having the slide part inside, and the light projecting part and / or the light receiving part by pressurizing air. A cuff that makes the light-receiving unit contact the living body and pressurizes the living body, a pressure adjusting unit that adjusts the pressure of the cuff, and a pulse wave of the living body when the pressure adjusting unit pressurizes and depressurizes the cuff Obtained from the light receiving unit by repressurizing the cuff so as to become a predetermined measurement reference pressure based on a pulse wave measurement unit for measuring a change in the pulse wave and a pulse wave change obtained by the pulse wave measurement unit Blood pressure generation that measures blood components in the living body based on the signal And having a measuring unit.

  According to such a configuration, the optical axis of the light projecting unit and the light receiving unit is maintained in the same state by the action of the slide unit, and the pulse wave is stabilized when measured while being pressurized to the measurement reference pressure by the cuff, In addition, since the light projecting unit and the light receiving unit are in close contact with the living body, blood components in the living body can be accurately measured without being affected by the shape and movement of the measurement target.

  A contact member that is provided around each of the light projecting unit and the light receiving unit, contacts the living body together with the light projecting unit and the light receiving unit, and an adsorbing unit that adsorbs the contact member to the living body by negative pressure. You may have. According to such an adsorbing unit, the light projecting unit and the light receiving unit can be further brought into close contact with the living body, and blood flow is not hindered.

  The cuff may include a first cuff provided with the light projecting unit and a second cuff provided with the light receiving unit. According to such a two-part cuff, generation of wrinkles is prevented and the living body is easily pressurized.

  The pulse wave measurement unit pressurizes the cuff to a predetermined pressure, and then depressurizes, obtains a systolic blood pressure and a diastolic blood pressure based on the obtained pulse wave signal, and determines the measurement standard based on the systolic blood pressure and the diastolic blood pressure The pressure is obtained, and the measurement reference pressure is a range of ¼ of the difference in blood pressure between the highest blood pressure and the lowest blood pressure centered on the intermediate blood pressure or the maximum amplitude pulse wave between the highest blood pressure and the lowest blood pressure. The pressure may be set to any of the above. Thereby, the pulse wave can be further stabilized.

  The pulse wave measurement unit may obtain a maximum blood pressure and a minimum blood pressure by an oscillometric method. According to the oscillometric method, the maximum blood pressure and the minimum blood pressure can be obtained with a simple configuration.

  The means for pressurizing the cuff and the means for setting the suction part to a negative pressure may use at least part of the intake air and the exhaust gas in common. Thereby, it becomes a simple structure.

  According to the blood component measurement device of the present invention, the pulse wave is obtained when the optical axis of the light projecting unit and the light receiving unit is maintained in the same state by the action of the slide unit, and measurement is performed while applying a predetermined pressure by the cuff. Since the light projecting unit and the light receiving unit are in close contact with the living body, the blood components in the living body can be accurately measured without being affected by the shape and movement of the measurement target.

  Hereinafter, embodiments of the blood component measuring apparatus according to the present invention will be described with reference to FIGS.

  As shown in FIG. 1, a blood component measurement device 10 according to the present embodiment is a portable device that non-invasively measures glucose concentration in blood, and includes a finger insertion unit 12, a display unit 14, and an operation. A button group 16. The finger insertion part 12 is a hole which penetrates so that an index finger (living body) can be inserted and can protrude from the opposite surface, for example. The display unit 14 is a liquid crystal monitor, and can display the glucose concentration and various types of information as a measurement result, and is provided in a place with good visibility when the index finger is inserted into the finger insertion unit. The operation button group 16 includes a power button, a measurement start button, a measurement stop button, a setting button, and the like, and is provided at a position where the thumb can be operated with the index finger inserted into the finger insertion unit 12.

  As shown in FIG. 2, the blood component measuring apparatus 10 is integratedly controlled by a computer 20, which includes a display unit 14, an operation button group 16, a light projecting light source unit 22, a light receiving element unit 24, a temperature. The sensor 26, the suction means 28, and the pump 29 are connected.

  The light projecting light source unit 22 includes three infrared LEDs 30a, 30b, and 30c having different output wavelengths, a condenser 32 that collects light from the infrared LEDs 30a to 30c into one, and a light projecting light that guides the light from the condenser 32 to a finger. And a light body 34. Infrared LEDs may be 1, 2 or 4 or more based on design conditions. The infrared LEDs 30a to 30c generate, for example, light having a single wavelength corresponding to three wavelengths corresponding to the measurement purpose in the near infrared, and at least one light having a wavelength suitable for blood glucose (glucose) measurement (for example, A wavelength selected from 900 nm to 2000 nm).

  The light receiving element unit 24 includes a light receiving light guide 36 that receives light projected from the light projecting light guide 34 and transmitted through the finger, and a light receiving element 38 that receives the light guided to the light receiving light guide 36. Have The light receiving element 38 is, for example, a photodiode.

  The light projecting light guide 34 and the light receiving light guide 36 are one optical fiber, a plurality of optical fiber bundles, an acrylic light guide, or the like, and are connected to the probes 40 and 42 that come into contact with the finger. By using the light projecting light guide 34 and the light receiving light guide 36, the degree of freedom of arrangement of the light projecting light source unit 22 and the light receiving element unit 24 is increased, and the optical axis is stabilized. The light projecting light guide 34 and the light receiving light guide 36 are not necessarily provided. For example, the light receiving light guide 36 may be omitted and the light receiving element 38 may be provided at the tip of the probe 42.

  The temperature sensor 26 is a contact-type sensor that measures the temperature of a finger, and examples thereof include a thermistor, a thermocouple, and a semiconductor sensor. According to such a contact sensor, the skin temperature can be measured easily and reliably. The temperature sensor 26 is not limited to the contact type, and may be a radiation thermometer using a non-contact type infrared sensor (bolometer, thermopile, etc.). The probes 40 and 42 and the temperature sensor 26 are included in the measurement mechanism 44.

  The suction means 28 is a device that generates a negative pressure, such as a vacuum pump or an ejector, and has two suction tubes 46a and 46b connected to the probes 40 and 42 via the branch pipe 45. 42 can be adsorbed to the finger.

  The pump 29 is a pneumatic pressurizing device, and two pressurizing tubes 47a and 47b via a branch pipe 45 are connected to cuffs 72a and 72b described later, and pressurizes the cuffs 72a and 72b. Can do. A valve 48 and a pressure sensor 49 are provided in the middle of the output line of the pump 29.

  The suction means 28 and the pump 29 may share at least part of the intake action and the exhaust action. For example, the exhaust of the suction means 28 may be directly introduced into the cuffs 72a and 72b. Thereby, it can be set as a simple structure. In this case, in order to compensate for a predetermined positive pressure and a predetermined negative pressure, a regulator, a relief valve, a check valve and the like may be provided as appropriate.

  The computer 20 includes a timing control unit 50, a light projection control unit 52, a light reception control unit 54, a body temperature measurement unit 56, an adsorption control unit 58, a spectrum analysis unit 60, a difference analysis unit 62, a blood glucose level calculation unit 64, and a pressure adjustment unit 66. And a pulse wave measuring unit 68 and a storage unit (not shown). Each of these functional units is realized mainly by software processing.

  The timing control unit 50 controls a series of blood glucose measurement sequences. The light projecting control unit 52 is connected to the light projecting light source unit 22 and controls the light projecting of the infrared LEDs 30a to 30c. The light reception control unit 54 is connected to the light receiving element unit 24, and receives a light reception signal from the light receiving element 38 every minute time at a predetermined measurement timing and supplies it to the spectrum analysis unit 60. For example, the light reception control unit 54 performs measurement for several seconds at a light reception cycle of about 20 to 200 times per second. The body temperature measurement unit 56 is connected to the temperature sensor 26 and inputs a finger temperature signal. The adsorption control unit 58 controls the adsorption unit 28.

  The pressure adjustment unit 66 adjusts the pressure of the cuffs 72 a and 72 b via the pump 29 and the valve 48. Based on the signal from the pressure sensor 49, the pulse wave measurement unit 68 measures the change in the pulse wave of the finger when the pressure adjustment unit 66 increases or decreases the cuffs 72a and 72b.

  The spectrum analysis unit 60 performs spectrum analysis of each light reception signal obtained from the light reception control unit 54 and obtains the intensity of light having a predetermined wavelength. The difference analysis unit 62 specifies a systolic signal Q1 (see FIG. 3) and a diastole signal Q2 (see FIG. 3) from the spectrum signal obtained from the spectrum analysis unit 60, and obtains a difference spectrum waveform thereof.

  As shown in FIG. 3, the spectrum signal Q having a predetermined wavelength corresponding to blood glucose measurement has a shape corresponding to a pulse wave due to fluctuations in arterial blood, and is high in the systole and low in the diastole. A plurality of black circles in FIG. 3 are measurement signals. The spectrum signal Q includes a portion 69a that varies according to arterial blood, a portion 69b that corresponds to venous blood that does not vary, and a portion 69c that corresponds to tissue other than blood.

  The blood glucose level calculation unit 64 compares the difference spectrum waveform given as input data from the difference analysis unit 62 with a predetermined sample spectrum waveform, estimates and calculates the blood glucose level from the most similar one, and outputs it to the display unit 14 To do. The difference spectrum waveform is an absorption spectrum that depends only on the absorption component of arterial blood, and does not include absorption components from tissues other than venous blood or blood, so these effects can be removed and highly accurate blood glucose measurement Is possible. The blood sugar level calculation unit 64 further corrects the blood sugar level based on the skin temperature obtained from the temperature sensor 26. As described above, the influence of the body temperature on the blood glucose level can be compensated by the signal from the temperature sensor 26.

  The spectrum analysis unit 60, the difference analysis unit 62, and the blood glucose level calculation unit 64 may process in real time in accordance with the timing at which the light reception control unit 54 inputs a signal from the light receiving element unit 24, and once the obtained signal is processed. You may process after memorize | storing in a predetermined memory | storage part. The blood glucose level measurement process in the computer 20 may use, for example, the method described in Patent Document 1.

  As shown in FIGS. 4, 5, and 6, the measurement mechanism 44 is provided in the finger insertion portion 12, and supports the light projecting side probe 40, the light receiving side probe 42, and these probes 40 and 42. It has a frame 70, a cylinder 71 provided in the frame 70, and a (first) cuff 72 a and a (second) cuff 72 b provided in the cylinder 71.

  The cuffs 72a and 72b have a hollow elastic body structure similar to that of an arm used for blood pressure measurement, are semi-cylindrical, are opposed to each other vertically, and form a substantially cylindrical shape in pairs. A slight gap is provided between the cuff 72a and the cuff 72b so as to be inflatable. The tip surface of the probe 40 is fixed to the center portion of the inner surface of the cuff 72a, and the tip surface of the probe 42 is fixed to the center portion of the inner surface of the cuff 72b. The cuffs 72a and 72b are pressurized and expanded under the action of the pressure adjusting unit 66, and the light projecting unit of the probe 40 and the light receiving unit of the probe 42 are brought into contact with the finger, and the finger can be pressurized.

  The cuffs 72a and 72b may have an integrated structure similar to that for general blood pressure measurement depending on design conditions.

  As shown in FIG. 6, a hole constituted by a cylindrical wall 75 that communicates from the inner surface 74 a to the outer surface 74 b is provided at the center of the cuff 72 b, and the periphery of the flange body 78 of the probe 42 is in relation to the cylindrical wall 75. And hermetically fixed by welding or bonding. The cuff 72a has the same structure. The cylindrical wall 75 may have, for example, a bellows structure so as to easily expand and contract in the sliding direction of the rod 76.

  As shown in FIGS. 7 and 8, the probe 42 includes a rod 76 that can advance and retreat with respect to the frame body 70, a flange body (contact member) 78 provided at the tip of the rod 76, and the rod 76. And a coil spring (elastic body) 80 for urging in the direction of the finger.

The rod 76 has a skin contact surface 82 at the front end, a head 84 constituting the skin contact surface 82, and a stopper 86 at the rear end. The light receiving light guide 36 is linearly provided on the shaft core of the rod 76 from the rear end to the skin contact surface 82, and the front end surface 36a of the light receiving light guide 36 serves as a light receiving portion. The skin contact surface 82 is provided around the distal end surface 36a, forms the same surface together with the distal end surface 36a, and integrally contacts the finger. Area of the skin contact surface 82, it is preferable 7mm ² ~35mm ^2. Formation of the light projecting unit by setting the skin contact surface 82 to 7 mm ² or more and the light receiving portion is simplified, by the 35 mm ² or less, moderately become small area in close contact matches the surface of the living body easily. A temperature sensor 26 is provided on the skin contact surface 82. The temperature sensor 26 may be provided on the flange body 78.

  The rod 76 is inserted into a guide hole (slide part) 90 provided in the frame body 70 with almost no gap, and the axial direction along the guide hole 90 (in other words, the optical axis direction of the light projecting part). Will be guided along.

  The coil spring 80 is a weak spring and urges the head 84 lightly toward the finger via the flange body 78. The stopper 86 is brought into contact with the frame body 70 for initial positioning. By inserting a finger into the finger insertion portion 12, the coil spring 80 is compressed and lightly pressed down. By this coil spring 80, the skin contact surface 82 and the flange body 78 can be reliably brought into contact with the finger in the initial state.

The flange body 78 is a contact member that is provided around the head 84 and contacts the finger together with the distal end surface 36a. The flange body 78 has a central hole 88 into which the rod 76 is inserted and a shape that opens to the distal end side. It has a supporting recess 91, an annular groove (suction part) 94 provided on the front end surface 92, and a plurality of intake holes 96 provided on the bottom surface of the annular groove 94. Each intake hole 96 is connected to the suction tube 46b via an internal communication path 98, and the annular groove 94 can adsorb the flange body 78 and the rod 76 to the finger by negative pressure. Total area of the front end surface 92 and the skin contact surface 82 of the flange body 78, 35mm ² ~80mm ² is preferred, easily brought into close contact against the finger.

  The center hole 88 is a hole having a slightly larger diameter than the rod 76, and the flange body 78 can be inclined. The head 84 and the concave portion 91 constitute a simple tilting mechanism by the corresponding convex spherical surface and concave spherical surface, and the flange body 78 can tilt in any direction around the skin contact surface 82 by sliding these surfaces. In addition, the head 84 can be reliably supported.

  The probe 40 is different from the probe 42 in that the rod 76 is fixed to the frame body 70 and there is no stopper 86. The coil spring 80 in the probe 40 is provided to support the flange body 78 and hardly compresses. In the probe 40, a light projecting light guide 34 is provided instead of the light receiving light guide 36, and a front end surface 34 a of the light projecting light guide 34 serves as a light projecting unit. The communication path 98 inside the probe 40 is connected to the suction tube 46a. The temperature sensor 26 may be provided on either the probe 40 or the probe 42. Since the probe 40 has a vertically symmetrical structure with respect to the probe 42 except for these, the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the measurement mechanism 44 configured as described above, as shown in FIG. 10, when a finger is inserted into the finger insertion portion 12, the coil spring 80 of the probe 42 is compressed, and each rod 76 slides downward, and each skin The contact surface 82 contacts the upper and lower surfaces of the finger.

  The coil spring 80 is a sufficiently weak spring (at least weaker than the attracting force by the annular groove 94), is easy to insert a finger, and in the initial state, each skin contact surface 82 and the flange body 78 with respect to the finger. It can be made to contact lightly, and the subsequent adsorption by the annular groove 94 can be performed quickly and reliably. Moreover, since the coil spring 80 is sufficiently weak, the finger is not excessively pressed, the blood flow of the finger is not inhibited, and measurement of blood components is not affected. The coil spring 80 may be omitted depending on design conditions.

  Further, since each flange body 78 is inclined according to the surface of the finger, the flange body 78 and the skin contact surface 82 are more likely to be in close contact with the finger. The flange body 78 is brought into close contact with the finger by an adsorption action due to the negative pressure of the annular groove 94, but this adsorption action does not impede the blood flow of the finger.

  As is clear from FIGS. 4 and 10, the tip surface 34a as the light projecting portion and the tip surface 36a as the light receiving portion are provided on the same optical axis J at opposite positions, and a measurement target finger can be inserted therebetween. It is. The optical axis of the distal end surface 34a and the distal end surface 36a is maintained in the same state by the sliding action of the rod 76 by the guide hole 90. In addition, the distal end surface 34a and the distal end surface 36a do not dissociate with respect to the finger even if the finger moves irregularly to some extent, and contact with each other without fail, and there is no air layer. Light and light reception are possible. As a result, the blood component measuring apparatus 10 accurately measures the blood component in the living body without being affected by the optical axis being shifted or the air layer being not generated due to the shape or movement of the finger as the measurement target. can do.

  Next, the operation of the blood component measuring apparatus 10 configured as described above will be described. First, after turning on the power, a finger (for example, an index finger) is inserted into the finger insertion unit 12 and a predetermined measurement start button is pressed. Thereby, measurement is started. In the first half (steps S1 to S8) of this measurement process, blood pressure is measured by the oscillometric method, and in the second half (steps S9 to S16), blood glucose level is measured. According to the oscillometric method, the systolic blood pressure P1 and the systolic blood pressure P2 (see FIG. 13) can be obtained with a simple configuration.

  In step S1 of FIG. 11, the pump 29 is driven by the pressure adjusting unit 66 to pressurize the cuffs 72a and 72b to a predetermined pressure. Thereafter, a pulse wave signal is input from the pressure sensor 49, and after confirming that a pressure equal to or higher than the estimated maximum blood pressure has been reached from the change in the magnitude of each pulse wave, the process proceeds to step S2.

  In step S2, the valve 48 is opened, and the pressure reduction of the cuffs 72a and 72b is started. The subsequent decompression is a moderately moderate and continuous decompression.

  In step S3, a pulse wave signal is input from the pressure sensor 49 and recorded in a predetermined recording unit in correspondence with the pressures of the cuffs 72a and 72b at that time. An example of this recording is shown in FIG. The pulse wave signal may be recorded as waveform data as shown in the graph of FIG. 13, or each peak value of the pulse wave may be recorded as numerical data. The horizontal axis of the graph in FIG. 13 indicates that time elapses toward the right side or that the pressure becomes low.

  In step S4, it is confirmed whether or not the pressure of the cuffs 72a and 72b has decreased to a predetermined end reference pressure. When the pressure has decreased to the end reference pressure, the process proceeds to step S5, and when the pressure has not reached the end reference pressure, the process returns to step S3.

  In step S5, the valve 48 is fully opened, and the pressures of the cuffs 72a and 72b are set to zero. This step S5 may be omitted, and the pressure at that time may be held until step S10 described later.

  In step S6, the maximum Pmax among the peak values of each pulse wave is obtained from the pulse wave signal shown in FIG.

  In step S7, a location of a% with respect to Pmax is obtained at a location where the pressure is higher than Pmax, and recorded as a maximum blood pressure P1 in a predetermined recording unit.

  In step S8, a portion of b% relative to Pmax is obtained at a location lower in pressure than Pmax, recorded as a minimum blood pressure P2 in a predetermined recording unit, and the blood pressure measurement processing by the pulse wave method is terminated. The maximum blood pressure and the minimum blood pressure may be obtained based on the envelope 99 in the graph of FIG. 13 or an interpolation line corresponding thereto.

  The blood pressure measurement process in steps S1 to S8 is not limited to the oscillometric method, and may be the Korotkoff method based on the K sound (pulse wave signal), the photoelectric volume pulse wave method, the ultrasonic method, or the like. I can do it. The calculated maximum blood pressure and minimum blood pressure are displayed on the display unit 14.

  In step S9 of FIG. 12, the measurement reference pressure Pb is obtained. The measurement reference pressure Pb is a place where a pulse wave is stably obtained, and is simply matched with the intermediate blood pressure Pc (= (P1 + P2) / 2) between the highest blood pressure P1 and the lowest blood pressure P2, or corresponds to Pmax. The blood pressure may be matched with Pmax ′.

  The measurement reference pressure Pb may be any place where the pulse wave is stable other than Pc and Pmax '. In FIG. 13, the measurement reference pressure Pb may be selected from a place where the slope of the envelope 99 is gentle. When the blood pressure difference (that is, pulse pressure) Pd between the maximum blood pressure P1 and the minimum blood pressure P2 is used, the measurement reference pressure Pb is approximately the blood pressure difference Pd centered on the intermediate blood pressure Pc (or the position Pmax ′ of the maximum amplitude pulse wave). The pressure may be set to any pressure in the range of ¼ of the height. Thereby, a pulse wave can be stabilized.

  In step S10, the pressure adjusting unit 66 repressurizes the cuffs 72a and 72b until the measurement reference pressure Pb is reached. Thereafter, feedback is performed while referring to the value of the pressure sensor 49 until blood glucose level measurement is completed, and the measurement reference pressure Pb of the cuffs 72a and 72b is maintained.

  By pressurizing the cuffs 72a and 72b to the measurement reference pressure Pb, the pulse wave amplitude is sufficiently large and stable, and accurate measurement can be performed. The cuffs 72a and 72b have a two-part structure and are less likely to wrinkle, pressurize the entire circumference of the finger in a balanced manner, and blood flow is not significantly inhibited.

  The cuffs 72a and 72b can bring the probes 40 and 42 into contact with the upper and lower surfaces of the finger with an appropriate force. Since the cuffs 72a and 72b pressurize the fingers around the probes 40 and 42, the probes 40 and 42 can be shielded from the surroundings and the influence of ambient light can be reduced.

  In step S <b> 11, the suction control unit 58 causes the annular grooves 94 of the probes 40 and 42 to be in a negative pressure so as to be in close contact with the finger. At this time, the tip surfaces 34a and 36a of the probes 40 and 42 are already in contact with the finger by the action of the cuffs 72a and 72b and the coil spring 80, and can be more reliably brought into close contact by the negative pressure action of the annular groove 94. . Unlike the pressing action, this negative pressure action does not inhibit blood flow. It is desirable that the probes 40 and 42 do not obstruct blood flow because they are particularly in direct contact with the measurement location.

  In step S <b> 12, light is projected from the tip surface 34 a through the light projecting light guide 34 from the infrared LEDs 30 a to 30 c of the light projecting light source unit 22. Light that has passed through the artery, vein, and other tissues in the finger is received by the light receiving element 38 through the light receiving light guide 36 from the distal end surface 36a. The computer 20 receives a signal from the light receiving element 38 in a period corresponding to one or a plurality of pulses.

  At this time, the distal end surface 34a and the distal end surface 36a are provided on the same optical axis at opposite positions, and the optical axes of the distal end surface 34a and the distal end surface 36a are maintained in the same state by the sliding action of the rod 76 by the guide hole 90. ing. In addition, the distal end surface 34a and the distal end surface 36a do not dissociate with respect to the finger even if the finger moves irregularly to some extent, and contact with each other without fail, and there is no air layer. Light and light reception are possible. Further, the pulse wave is large and stable by the pressurizing action of the cuffs 72a and 72b.

  In step S13, the spectrum analysis unit 60 performs spectrum analysis of each light reception signal obtained from the light reception control unit 54, and obtains the intensity of light of a predetermined wavelength.

  In step S14, the difference analysis unit 62 specifies the signal Q1 and the signal Q2 (see FIG. 3) from the spectrum signal obtained from the spectrum analysis unit 60, and obtains these difference spectrum waveforms.

  In step S15, the blood sugar level calculation unit 64 compares the difference spectrum waveform given as input data from the difference analysis unit 62 with a predetermined sample spectrum waveform, and estimates and calculates the blood sugar level from the most similar one.

  In step S <b> 16, the obtained blood glucose level is output to the display unit 14. The blood glucose level is corrected based on the finger temperature obtained from the temperature sensor 26. Further, the valve 48 is opened to reduce the pressure of the cuffs 72a and 72b to 0, the infrared LEDs 30a to 30c are turned off, and a series of blood glucose measurement is completed.

  As described above, according to blood component measuring apparatus 10 according to the present embodiment, the optical axes of tip surface 34a of the light projecting unit and tip surface 36a of the light receiving unit are maintained in the same state by the action of guide hole 90. At the same time, the measurement is performed while applying pressure to the measurement reference pressure Pb by the cuffs 72a and 72b, so that the pulse wave is stabilized and the distal end surfaces 34a and 36a are in close contact with the finger. Therefore, the blood component can be accurately measured without being affected by the shape or movement of the finger that is the measurement target. This measurement is naturally non-invasive.

  The cuffs 72a and 72b of the blood component measuring device 10 are pressurized in the same manner at the same timing, and have substantially the same action. As in Patent Document 5, the cuffs 72a and 72b are individually separated on the upstream side and the downstream side. It is not a mechanism or individual control, but a simple structure. Further, during blood glucose measurement, the pressure of the cuffs 72a and 72b may be held at the measurement reference pressure Pb, and the control is simple.

  The blood component measurement device 10 measures blood glucose while the pulse wave is being generated, and is different from Patent Document 5 that is performed when blood is anemic. The blood component measurement apparatus 10 is suitable for acquiring a received light signal in real time without having to change or reselect the wavelengths of the infrared LEDs 30a to 30c in accordance with a pressure change.

  Note that both the probes 40 and 42 may be configured to be slidable with respect to the frame 70, and at least one of the probes 40 and 42 may be configured to be guided along the optical axis.

  The two skin contact surfaces 82 facing each other are not necessarily flat, and may be configured to have a gentle convex shape, for example. By providing the light projecting unit and the light receiving unit on the top of the convex surface, it becomes easier to adhere to the living body. The two skin contact surfaces 82 facing each other do not have to be parallel surfaces, and may be appropriately inclined so as to be easily contacted with a finger, for example.

  The blood component measuring apparatus 10 is not limited to a portable type, and may be a stationary type or the like, and is not limited to a finger type. For example, blood sugar may be measured using an earlobe or an arm. The blood component measurement apparatus 10 may be applied to hemoglobin concentration and oxygen saturation in addition to glucose concentration. In this case, the infrared wavelength may be emitted from the infrared LEDs 30a to 30c according to the measurement purpose.

  As shown in FIG. 14, the connection between the head 84 and the flange body 78 may be a spherical surface having the largest diameter at the center, and may be connected like a so-called ball joint. Thereby, while the head 84 and the flange body 78 are more reliably joined, the area of the skin contact surface 82 becomes small, and it is easy to make it adhere to skin.

   The connection between the head 84 and the flange body 78 may be performed by an elastic body that is elastic in the tilt direction and has little extension in the sliding direction of the rod 76.

  The blood component measuring apparatus according to the present invention is not limited to the above-described embodiment, but can of course adopt various configurations without departing from the gist of the present invention.

It is a perspective view of the blood component measuring device concerning this embodiment. It is a block block diagram of the blood component measuring device which concerns on this Embodiment. It is a received spectrum signal. It is a cross-sectional side view of a finger insertion part and a measurement mechanism. It is a cross-sectional front view of a finger insertion part and a measurement mechanism. It is a partially-omission cross-sectional perspective view of a finger insertion part and a measurement mechanism. It is a cross-sectional side view of the probe on the light receiving side. It is a perspective view of the probe by the side of light reception. It is a cross-sectional side view of the probe on the light projecting side. It is a cross-sectional side view of a finger insertion part and a measurement mechanism in a state where a finger is inserted. It is a flowchart (the 1) which shows the operation | movement procedure of a blood component measuring apparatus. It is a flowchart (the 2) which shows the operation | movement procedure of a blood component measuring apparatus. It is a graph of a pulse wave signal. It is a cross-sectional side view of the probe which concerns on a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Blood component measuring device 12 ... Finger insertion part 20 ... Computer (control part) 26 ... Temperature sensor 28 ... Adsorption means 29 ... Pump 30a-30c ... Infrared LED 34 ... Projection light guide 34a, 36a ... Tip surface (projection) 36, light receiving element 38, light receiving element 40, 42 ... probe 48 ... valve 49 ... pressure sensor 72a, 72b ... cuff 76 ... rod 78 ... flange body (contact member) 80 ... coil spring (elastic) body)
82 ... Skin contact surface 84 ... Head 88 ... Center hole 90 ... Guide hole (slide part)
94 ... annular groove (adsorption part) 96 ... intake hole

Claims (5)

A light projecting unit and a light receiving unit that are provided on the same optical axis at opposite positions and in which a living body to be measured can be inserted
A slide part for guiding at least one of the light projecting part and the light receiving part along the optical axis;
The light projecting portion and / or the light receiving portion having the slide portion on the inside thereof are provided, the light projecting portion and / or the light receiving portion are brought into contact with the living body by pressurizing air, and the living body is A cuff to pressurize,
A pressure adjusting unit for adjusting the pressure of the cuff;
A pulse wave measurement unit that measures a change in the pulse wave of the living body when the cuff is pressurized or depressurized by the pressure adjustment unit;
Based on the change of the pulse wave obtained by the pulse wave measurement unit, the cuff is repressurized so as to become a predetermined measurement reference pressure, and the blood component in the living body is measured based on the signal obtained from the light receiving unit. Blood pressure component measurement unit
An abutting member provided around each of the light projecting unit and the light receiving unit, and contacting the living body together with the light projecting unit and the light receiving unit;
An adsorbing part for adsorbing the contact member to the living body by negative pressure;
A blood component measuring apparatus comprising: A light projecting unit and a light receiving unit which are provided on the same optical axis at opposite positions and in which a living body to be measured can be inserted;
A slide part for guiding at least one of the light projecting part and the light receiving part along the optical axis;
The light projecting portion and / or the light receiving portion having the slide portion on the inside thereof are provided, the light projecting portion and / or the light receiving portion are brought into contact with the living body by pressurizing air, and the living body is A cuff to pressurize,
A pressure adjusting unit for adjusting the pressure of the cuff;
A pulse wave measurement unit that measures a change in the pulse wave of the living body when the cuff is pressurized or depressurized by the pressure adjustment unit;
Based on the change of the pulse wave obtained by the pulse wave measurement unit, the cuff is repressurized so as to become a predetermined measurement reference pressure, and the blood component in the living body is measured based on the signal obtained from the light receiving unit. Blood pressure component measurement unit
Have
The pulse wave measuring unit pressurizes the cuff to a predetermined pressure, and then depressurizes the cuff, obtains a systolic blood pressure and a diastolic blood pressure based on the obtained pulse wave signal, and determines the measurement standard based on the systolic blood pressure and the diastolic blood pressure. Find the pressure,
The measurement reference pressure is any one of a range of a high / low ¼ of a difference in blood pressure between the highest blood pressure and the lowest blood pressure centered on an intermediate blood pressure between the highest blood pressure and the lowest blood pressure or a location of a maximum amplitude pulse wave. A blood component measuring apparatus characterized by being set to pressure. The blood component measuring apparatus according to claim 1 or 2,
The blood component measuring apparatus according to claim 1, wherein the cuff includes a first cuff provided with the light projecting unit and a second cuff provided with the light receiving unit. In the blood component measuring apparatus according to claim 1 Symbol placement,
The blood wave measuring device, wherein the pulse wave measuring unit obtains a maximum blood pressure and a minimum blood pressure by an oscillometric method. The blood component measuring apparatus according to claim 1 , wherein
The blood component measuring apparatus according to claim 1, wherein the means for pressurizing the cuff and the means for bringing the adsorbing portion into a negative pressure share at least part of intake and exhaust.

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