JP2007202693A - Biological information detection sensor and blood pressure measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase an S/N ratio of a biological information detection sensor by reducing the noise thereof, more concretely, to reduce light which is reflected inside an elastic body provided in the photoelectric sensor of the biological information detection sensor and received by a light receiving element. <P>SOLUTION: The biological information detection sensor 10 is equipped with a pressure sensor 14 arranged on a substrate 11, the elastic body 12 for added pressure detection arranged on the substrate 11 for transmitting added pressure to the pressure sensor 14, and the photoelectric sensor 15 provided inside the elastic body 12 for the added pressure detection and provided with a light emitting element and the light receiving element, wherein the elastic body 12 for the added pressure detection includes an area where transmissivity to the light emission wavelength of the light emitting element is different, the transmissivity of the area between the substrate 11 and the photoelectric sensor 15 is made lower than the transmissivity between the photoelectric sensor 15 and the external contact surface 16 of the elastic body 12 for the added pressure detection and absorbance is increased. By configuring the transmissivity of the elastic body 12 for the added pressure detection as above, the intensity of light passing through an optical path not passing through a living body is reduced and noise components to detection signals for detecting biological information are reduced. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a blood pressure measurement device that measures the blood pressure of a subject and a biological information detection sensor used in the blood pressure measurement device.

  Conventionally, in a so-called blood pressure measurement device, a blood pressure value is measured using a measurement technique such as an oscillometric method or a volume vibration method. The oscillometric method, for example, compresses the blood vessel at the measurement site with a cuff (full circumference compression band) wrapped around the subject's living upper arm or wrist, and reflects the fluctuation of the cuff pressure that reflects the vibration of the blood vessel wall depending on the arterial pressure. From the behavior (pressure vibration wave), the maximum blood pressure (systolic blood pressure: SBP) and the minimum blood pressure (diastolic blood pressure: DBP) are obtained.

  On the other hand, the volume vibration method using a photoelectric sensor, for example, when the pressure of a cuff wrapped around a living body part such as a subject's finger or upper arm is increased or decreased, a minute blood vessel volume change caused by blood pressure is changed by the transmittance change by the sensor Detect as.

  The photoelectric sensor receives light transmitted from the light emitting element and transmitted through the living body by the light receiving element. In the volume vibration method, the blood pressure value is measured from the behavior with respect to the cuff pressure of the amplitude change of the volume pulse wave signal which is an AC component of the light reception signal of the light receiving element.

  A conventional blood pressure measurement device using such a volume vibration method is known not only in a configuration using a cuff (for example, Patent Documents 1, 2, and 3) but also in a configuration without using a cuff (for example, Patent Document 4). .

  A conventional blood pressure measurement device that uses a cuff and measures a blood pressure value using a volume vibration method measures blood pressure based on biological information related to arterial motion under cuff compression. As one example of this type of blood pressure measurement device, for example, a holding unit that holds a biological signal waveform that is a photoelectric volume pulse wave signal waveform at least four cycles before the present time, and a holding unit between the start of measurement and the end of measurement. And a display means for sequentially displaying the biological signal waveform from the present time until approximately four cycles before and the digital value of the current cuff pressure on the same display screen, for example, during the measurement of the blood pressure value And a cuff pressure are displayed to easily judge whether the measurement state is good or bad (see, for example, Patent Document 1).

  Further, as another blood pressure measuring device using the volume vibration method using the cuff, the cuff, the pressure detector for detecting the cuff pressure, the cuff pressure control pump for pressurizing the cuff, and the body pressurizing part by the cuff are different. A light emitting unit that emits light of two wavelengths, a light receiving unit that detects a transmitted light amount or a reflected light amount of light incident on the body from the light emitting unit, and a direct current component of each wavelength in a light reception signal obtained from the light receiving unit; There is also known a configuration having a demodulation circuit that separates a pulse wave component and a CPU (Central Processing Unit) that performs a process of obtaining a blood pressure value using a detection output from the demodulation circuit.

  The CPU captures the detection output from the demodulation circuit, calculates the allowable variation range from the oxygen saturation measured before cuff pressurization, and the oxygen saturation measured in the process of increasing the cuff pressure is the allowable variation range. If it is within the allowable variation range, the blood pressure value of the subject is calculated from the amplitude value and cuff pressure of the pulse wave component (photoelectric volume pulse wave signal), and within the allowable variation range If not, processing for invalidating the pulse wave component captured at that time is performed.

  Accordingly, the blood pressure value of the subject can be reliably measured even in a measurement environment accompanied by vibration, body movement, and the like, which are difficult to measure by a normal volume vibration method (see, for example, Patent Document 2).

  In addition, as another blood pressure measuring device using the volume vibration method using a cuff, a cuff, a pressure detector for detecting the cuff pressure, and a cuff pressure control for linearly pressurizing or lowering the cuff pressure Pump, a light emitting unit that irradiates light to the pressurized part of the body by the cuff, a light receiving unit that detects the amount of transmitted or reflected light incident on the body from the light emitting unit, and light reception obtained from the light receiving unit A configuration having a demodulation circuit that separates a pulse wave component in a signal and a CPU that performs processing for obtaining a blood pressure value using a detection output from the demodulation circuit is also known.

  When it is determined that the pulse wave component is not detected before cuff pressurization based on the detection output of the demodulation circuit, the CPU sends a control signal to the cuff pressure control pump to increase the cuff pressure or increase once Control to lower the cuff pressure, detect the inflection point in the received light signal in the process where the cuff pressure is increased or decreased, and the cuff pressure at this inflection point in the weak blood pressure state Output as the average blood pressure value of the subject.

  This makes it possible to determine whether or not the subject is in a weak blood pressure state and in a weak blood pressure state even for a subject placed in a shock state or an extremely low blood pressure state that is difficult to measure by the normal volume vibration method. For example, it is set as the structure which can measure the blood pressure value of the test subject (for example, refer patent document 3).

  Further, in the combination of the cuff and the photoelectric sensor, for example, the light emitting element and the light receiving element are provided close to each other on the inner wall of the cuff, and the light emitted from the light emitting element and reflected by the finger artery is received by the light receiving element. A configuration has also been proposed (see, for example, Patent Document 4).

  The blood pressure measurement device described above uses a cuff to compress the measurement site of the subject's living body to measure blood pressure, causing congestion at the measurement site, pain during measurement, and further increasing discomfort There is a risk of letting you. In addition, since the cuff needs to be attached to the measurement site, the measurement work may be troublesome. Furthermore, since the cuff is an essential configuration, there is a limit to downsizing, and it is difficult to reduce the number of parts.

  On the other hand, a blood pressure measurement device that measures a blood pressure value using a volume vibration method without using a cuff has been proposed. This blood pressure measuring device is output from, for example, a pressure body that has a photoelectric volume pulse wave sensor and a pressure bag attached to the tip, a pressure sensor that detects the pressure in the pressure bag, and a photoelectric volume pulse wave sensor. A control unit is provided that inputs a pulse wave signal and a pressure signal output from the pressure sensor to measure blood pressure.

  As a result, the blood pressure value can be measured by pressing an arbitrary part of the living body, the measurement work becomes extremely easy, and the measurement can be performed without being restricted with respect to the measurement part like measurement with a cuff. (For example, refer to Patent Document 5).

  There has also been proposed a blood pressure measurement device that detects a pressure pulse wave while applying varying pressure to an artery and determines blood pressure using waveform parameters obtained from pressure waveform data. In this blood pressure measurement device, by applying or urging the subject to apply variable pressure by audible or visual feedback, it is possible to recognize the state of force application to obtain the blood pressure value, and the blood pressure value by the subject is determined. It is set as the structure which can be measured (for example, refer patent document 6).

  In addition to the above, as a configuration for applying pressure to the living body without using a cuff, a configuration of a moving mechanism that presses the measurement head against the living body (see, for example, Patent Document 7), a fluid supply device, an air bag, or the like as the pressing means There are proposed a configuration in which the subject presses the blood pressure measuring device main body against the living body (see, for example, Patent Literature 10), and the like.

Japanese Examined Patent Publication No. 7-41028 Japanese Patent No. 2958503 Japanese Patent No. 2958471 Japanese Patent Laid-Open No. 61-238225 JP-A-6-311972 JP-T-2001-514916 Japanese Patent No. 3547379 Japanese Utility Model Publication No. 63-201509 Japanese Utility Model Publication No. 2-109603 Japanese Patent Publication No. 4-57338

  In the blood pressure measurement by the volume vibration method described above, a blood pressure measurement device that does not pressurize a living body with a cuff includes a sensor module having a pressure sensor and a photoelectric sensor, and this sensor module is used as a biological information detection sensor. The pressure pulse to the living body is measured by the pressure sensor, the volume pulse wave is detected by the photoelectric sensor, and the blood pressure value is measured from the behavior of the amplitude change of the volume pulse wave signal with respect to the cuff pressure.

  In detection of volume pulse waves by a photoelectric sensor, near red corresponding to the local blood volume due to arterial fluctuations on the optical path until light emitted from the light emitting element (for example, light in the near infrared region) is received by the light receiving element. This is done by detecting the change in the amount of light absorption in the outer region based on the received light intensity of the light receiving element. Therefore, this photoelectric sensor is desired to detect only light passing through the living body. However, in a photoelectric sensor, light that does not pass through a living body and is repeatedly reflected in the photoelectric sensor and received by the light receiving element exists between the light emitting element and the light receiving element. Such light that does not pass through the living body becomes noise for the photoelectric sensor, which may hinder accurate measurement of biological information.

  FIG. 16 is a configuration example of a biological information detection sensor. This biological information detection sensor 200 includes a photoelectric sensor having a light emitting element 215a and a light receiving element 215b, and a pressure sensor 214 on a substrate 211, and is covered with an elastic body 212. The living body information detection sensor 200 detects the pressure applied to the living body 20 by pressing the elastic body 212 against the living body 20 with the pressure sensor 214 as the pressure applied to the elastic body.

  Of the light emitted from the light emitting element 215a, the light passing through the optical path A in the elastic body 212 enters the living body 20, and then returns to the elastic body 212 again through the optical path B. The optical path in the elastic body 212 C is detected by the light receiving element 215b. While the light passes through the optical path B, the light absorption amount in the near infrared region corresponding to the local blood volume changes due to the arterial variation, and the light intensity changes in accordance with the light absorption amount change. The biological information detection sensor detects this change in light intensity as a volume pulse wave change.

  The light path from the light emitting element 215a to the light receiving element 215b is not limited to the light path A, B, C as described above, but passes through the living body, for example, the living body 20 like the light paths a, b, c in FIG. In some cases, the light reaches the light receiving element 215b by repeatedly reflecting at the interface of the elastic body 212 without passing through the light receiving element 215b. As an interface between the elastic body 212 and the boundary between the elastic body 212 and the atmosphere, there is a boundary between the elastic body 212 and the substrate 211.

  The optical path that passes only through the elastic body 212 changes as the elastic body 212 is deformed, and the optical path also changes. 16A shows a state where no pressure is applied to the elastic body 212, and FIG. 16B shows a state where pressure is applied to the elastic body 212. FIG.

  When the elastic body 212 is deformed by pressing the elastic body 212 against the living body 20, the optical path passing through the elastic body 212 also changes (A ', C', a ', b', c '). The light receiving element 215b detects the change in the optical path due to the deformation of the elastic body 212 as a change signal without distinguishing it from the volume pulse wave due to the arterial fluctuation in the living body 20. Distinguishing whether the intensity change of the received light signal detected by the light receiving element 215b is a change component of biological information to be originally detected or a deformation signal resulting from the deformation of the elastic body 212 due to external vibration. It is difficult. In blood pressure measurement devices and pulse measurement devices, it is important to acquire in-vivo optical information, and it is preferable that there is no change in the optical path in other parts of the living body.

  In the configuration shown in FIG. 16, due to the deformation of the elastic body 212, not only the optical path (for example, a, b, c) that passes through only the elastic body 212 but also a part of the optical path (for example, A, C) that passes through the living body 20. However, since the optical path changes, the light reception signal by the light passing through these optical paths becomes noise.

  FIG. 17 shows a configuration in which the light emitting element 215 a and the light receiving element 215 b are arranged away from the substrate 211 and close to the outer boundary surface of the elastic body 212. FIG. 17A shows a state where no pressure is applied to the elastic body, and FIG. 17B shows a state where pressure is applied to the elastic body.

  According to this configuration, since the light emitting element 215a and the light receiving element 215b approach the living body, even when the elastic body 212 is deformed, the amount of change in the optical path (A, B, C) passing through the living body is reduced. Can do. However, for the optical path (for example, a, b, c) that reaches the light receiving element 215b after repeated reflection inside the elastic body 212, the optical path varies with the change of the elastic body (for example, a ′ , B ′, c ′), the light reception signal by the light passing through the optical path passing through the elastic body 212 becomes noise.

  Thus, the presence of light whose optical path fluctuates due to the change of the elastic body 212 becomes noise when detecting biological information, and thus the S / N ratio (Signal to Noise ratio) is improved. Therefore, it is desirable to remove such light as much as possible.

  Therefore, the present invention aims to solve the conventional problems and reduce the noise of the biological information detection sensor to improve the S / N ratio. More specifically, the present invention provides an elastic body included in the photoelectric sensor of the biological information detection sensor. The object is to reduce the light reflected by the light receiving element.

  The living body information detection sensor of the present invention receives transmitted light emitted from the light emitting element and transmitted through the living body by the light receiving element, and detects information such as blood pressure and pulse of the living body by changing the light intensity or transmittance of the detected light. It is a sensor to do.

  This biological information detection sensor can be applied to a blood pressure measurement device using a volume vibration method. In this blood pressure measurement device based on the volume vibration method, when a living body is pressurized, a minute change in the volume of blood vessels caused by blood pressure is detected by a light receiving element that receives transmitted light that has been emitted from the light emitting element and transmitted through the living body. This is detected as a change in light intensity or a change in transmittance, and the blood pressure value is measured from the behavior of the amplitude change of the volume pulse wave signal, which is the AC component of the light reception signal of the light receiving element, with respect to the pressure of the additional pressure detecting elastic body.

  In the optical path connecting the light emitting element and the light receiving element, light passing through the optical path that does not pass through the living body becomes noise for detection of biological information. The biological information detection sensor of the present invention reduces the noise of the detection signal by making the transmittance of the optical path that does not pass through the living body smaller than the transmittance of the optical path that passes through the living body.

  The biological information detection sensor of the present invention includes a pressure sensor disposed on a substrate, an additional pressure detection elastic body that is disposed on the substrate and transmits pressure applied to the pressure sensor, and an additional pressure detection elastic body. In the configuration including the light emitting element and the photoelectric sensor including the light receiving element, the additional pressure detection elastic body includes a region having different transmittances with respect to the emission wavelength of the light emitting element, and between the substrate and the photoelectric sensor. The transmittance of the region is made smaller than the transmittance between the photoelectric sensor and the external contact surface of the additional pressure detecting elastic body, and the absorption rate is increased. The intensity of light that has passed through a region having a low transmittance and a high absorption rate is lower than the intensity of light that has passed through a region having a high transmittance. Therefore, by setting the transmittance of the elastic body for detecting additional pressure as described above, the intensity of light passing through the optical path that does not pass through the living body is reduced, and the noise component for the detection signal for detecting living body information is reduced. .

  One form of the biological information detection sensor of the present invention is a form in which the region provided in the elastic body for detecting the additional pressure is configured by at least two elastic bodies having different transmittances with respect to the emission wavelength of the light emitting element. In this embodiment, in order from the substrate side toward the external contact surface of the elastic body for detecting the additional pressure, the elastic body having a small transmittance with respect to the light emitting wavelength of the light emitting element, the photoelectric sensor, and the light emitting wavelength of the light emitting element An elastic body having a large transmittance is arranged in layers.

  Of the light emitted from the light emitting element, the light traveling to the elastic body having a small transmittance with respect to the light emitting wavelength of the light emitting element is compared with the light traveling to the elastic body having a large transmittance with respect to the light emitting wavelength of the light emitting element. It attenuates greatly.

  In the above-described form, the photoelectric sensor is configured such that an elastic body having a low transmittance is disposed on the substrate side and an elastic body having a large transmittance is disposed on the external contact surface side, so that the living body can be transferred from the external contact surface to the living body. While suppressing a decrease in the light intensity of the traveling light and the light returning through the living body, the intensity of the light traveling to the substrate side is reduced to reduce noise.

  In this embodiment, the at least two elastic bodies having different transmittances for the light emission wavelength of the light emitting element may be a first elastic body and a second elastic body having different transmittances for the light emission wavelength of the light emitting element. it can.

  In the embodiment including the first elastic body and the second elastic body, the first elastic body having a large transmittance with respect to the light emission wavelength of the light emitting element is disposed on the outer contact surface side of the photoelectric sensor, and light emission is performed. A second elastic body having a small transmittance with respect to the light emission wavelength of the element is disposed between the substrate and the photoelectric sensor.

  Of the light emitted from the light emitting element, the light traveling to the second elastic body having a small transmittance with respect to the light emitting wavelength of the light emitting element has the first elastic body having a large transmittance with respect to the light emitting wavelength of the light emitting element. It attenuates greatly compared to the light traveling to.

  In the above-described form, the photoelectric sensor has a configuration in which the second elastic body having a low transmittance is disposed on the substrate side and the first elastic body having a large transmittance is disposed on the external contact surface side. While suppressing the fall of the light intensity of the light which advances to a living body from an external contact surface, and the light which passed through the biological body and returned, the intensity | strength of the light which advances to a board | substrate side is reduced, and a noise component is reduced.

  In another form of the biological information detection sensor of the present invention, the area of the elastic body for detecting the additional pressure is provided such that the transmittance of the light emitting element with respect to the emission wavelength is directed from the substrate side to the external contact surface of the elastic body for detecting the additional pressure. In this configuration, the elastic body changes gradually or in multiple stages. In this embodiment, at least the transmittance at the position of the photoelectric sensor is set, and the light intensity of the emitted light on the external contact surface of the additional pressure detecting elastic body is set to a level sufficient for detection by the photoelectric sensor.

  Of the light emitted from the light emitting element, the light traveling in the direction of small transmittance with respect to the light emitting wavelength of the light emitting element is greatly attenuated compared with the light traveling in the direction of large transmittance with respect to the light emitting wavelength of the light emitting element. .

  The above-described form is configured to arrange an elastic body whose transmittance gradually or multistagely changes from the substrate side toward the external contact surface of the elastic body for detecting additional pressure, so that light traveling from the external contact surface to the living body, And while suppressing the fall of the light intensity of the light which returned through the biological body, the intensity | strength of the light which progresses to the board | substrate side is reduced, and a noise part is reduced.

  Moreover, the elastic body for additional pressure detection can form the optical path which connects between a photoelectric sensor and a biological body by the area | region where the transmittance | permeability differs. The optical path is configured to change the transmittance between the position of the external contact surface of the elastic body for detecting additional pressure and the light emitting element of the photoelectric sensor, and between the light receiving element and the light receiving element. It can be formed by making it larger than the transmittance.

  In the configuration in which the photoelectric sensor described above is arranged in the elastic body for detecting the additional pressure, the photoelectric sensor is added by placing the photoelectric sensor on the flexible substrate and providing the flexible substrate in the elastic body for detecting the additional pressure. It can be held in an elastic body for pressure detection.

  According to this configuration, the physical holding force of the elastic body for detecting the additional pressure is weak, and it is difficult to determine the position of the photoelectric sensor when the photoelectric sensor is placed in the elastic body for detecting the additional pressure. In addition, by using a flexible substrate, the contact area with the elastic body for detecting the additional pressure can be increased, whereby the positioning of the photoelectric sensor with respect to the elastic body for detecting the additional pressure can be facilitated.

  In addition, by making the elastic coefficient of the elastic body having different transmittances included in the biological information detection sensor of the present invention substantially the same, the elastic body for detecting the additional pressure is equivalent to being added to the living body by contacting the living body. The pressure can be transmitted to a pressure sensor placed on the substrate, and the pressure sensor can detect the magnitude of the pressure applied to the living body.

  Moreover, the elastic body for additional pressure detection of this invention can be formed with a gel.

  The biological information detection sensor of the present invention can be applied to a blood pressure measurement device. The blood pressure device has an inscribed portion that is inscribed in the subject's living body, and is relatively movable between the fixing means for fixing the living body via the inscribed portion and the fixing means, and the measurement site of the living body Detecting means for detecting volume pulse wave information relating to the volume pulse wave of the subject and pressure information relating to the pressing force, driving means for pressing the detecting means against the measurement site, and the volume detected by the detecting means A blood pressure value determining means for determining the blood pressure value of the subject based on the pulse wave information and the pressure information, and the biological information detecting sensor of the present invention is used as the detecting means.

  Moreover, the blood pressure measurement device 30 of the present invention includes a control unit that controls the operation of the drive unit that drives the detection unit. The control means controls the drive means based on predetermined operation parameters so that the volume pulse wave information and the pressure information are detected by an optimum pressing operation by the detection means.

  Further, the control means controls the driving means, performs a pressing operation on the measurement site by the detection means a plurality of times, and calculates predetermined operation parameters based on the volume pulse wave information and pressure information obtained by each pressing operation.

The blood pressure value determining means of the present invention calculates the blood pressure value based on the volume pulse wave information and pressure information obtained by the pressing process and the pressure reducing process to the measurement site by the detecting means, respectively. For example, the maximum blood pressure (Ps) and the average blood pressure (Pm) are calculated, and the minimum blood pressure (Pd) is calculated by the following calculation formula.
Pd = (3 × Pm−Ps) / 2

  Further, the blood pressure measurement device of the present invention includes an extraction means for extracting a subject's pulse rate and pulse wave amplitude value from volume pulse wave information detected by the detection means, and a pulse rate and pulse wave amplitude value extracted by the extraction means. Based on the determination result determined by the determination means and the determination result determined by the determination means, and whether or not the pulse rate and the pulse wave amplitude value are within the predetermined range An informing means for informing by at least one of sound, sound, vibration and display.

  According to the biological information detection sensor of the present invention, the noise of the biological information detection sensor can be reduced and the S / N ratio can be improved, and the light receiving element reflects the elastic body included in the photoelectric sensor of the biological information detection sensor. The received light can be reduced.

  According to the blood pressure measurement device of the present invention, blood pressure can be measured by mechanically pressing a measurement site of a living body without using a cuff. In addition, a highly accurate measurement result can be easily obtained, and the apparatus can be downsized and uncomfortable during measurement can be reduced.

  Hereinafter, a biological information detection sensor of the present invention and a blood pressure measurement device including the biological information detection sensor will be described in detail with reference to the drawings.

  1 and 3 to 7 are a schematic sectional view and a front view for explaining each form of the biological information detection sensor of the present invention, and FIG. 2 is an elastic body for detecting additional pressure of the biological information detection sensor of the present invention. It is a characteristic view of the transmittance | permeability (light reception intensity) with which is equipped.

[Description of the first embodiment: FIG. 1]
First, a first embodiment of the biological information detection sensor of the present invention will be described with reference to FIG. 1A shows a state where the pressing force is small, and FIG. 1B shows a state where the pressing force is large.

  The biological information detection sensor 10 of the present invention includes a pressure sensor 14 disposed on the substrate 11, an additional pressure detection elastic body 12 disposed on the substrate 11 and transmitting pressure applied to the pressure sensor 14, and an addition A photoelectric sensor 15 provided in the pressure detecting elastic body 12 is provided. The photoelectric sensor 15 includes a light emitting element 15a that emits light toward a living body and a light receiving element 15b that receives light returned from the living body. The photoelectric sensor 15 is electrically connected to the substrate 11 by the wiring 13. Although not shown, the substrate 11 is provided with a connector for connecting to the outside and transmitting and receiving electrical signals.

  The elastic body 12 for detecting additional pressure according to the present invention is compressed by the reaction of the additional pressure applied to the living body 20 when a pressing operation is performed between the biological information detecting sensor 10 and the living body 20, and is the same as the additional pressure. The pressure is transmitted to the pressure sensor 14 on the substrate 11. The pressure sensor 14 measures the applied pressure applied to the living body 20 by detecting this pressure. The measured additional pressure is detected as pressure information related to the pressing force.

  The additional pressure detecting elastic body 12 includes a region where the transmittance with respect to the emission wavelength of the light emitting element 15a is different, and the transmittance of the region between the substrate 11 and the photoelectric sensor 15 is expressed by the photoelectric sensor 15 and the additional pressure detecting elastic body. The transmittance between the 12 external contact surfaces 16 is made smaller. In the first embodiment shown in FIG. 1, the additional pressure detecting elastic body 12 includes a first elastic body 12a and a second elastic body 12b having different transmittances with respect to the emission wavelength of the light emitting element 15a. The photoelectric sensor 15 is disposed at the position of the boundary surface 12c between the elastic body 12a and the second elastic body 12b.

  Here, the first elastic body 12a constitutes an additional pressure detecting elastic body between the photoelectric sensor 15 and the external contact surface 16 of the additional pressure detecting elastic body 12, and the second elastic body 12b is a substrate. 11 and an elastic body for detecting an additional pressure between the photoelectric sensor 15.

  The transmittance of the light emitted from the light emitting element 15a with respect to the wavelength of the light is different between the first elastic body 12a and the second elastic body 12b, and the transmittance of the second elastic body 12b is the transmission of the first elastic body 12a. Set to be lower than the rate.

[Explanation of transmission spectrum in elastic body: Fig. 2]
FIG. 2 shows the transmittance of the first elastic body 12a and the second elastic body 12b with respect to the wavelength. The transmission spectrum of the first elastic body 12a has a characteristic of transmitting light having a wavelength emitted from the light emitting element 15a, whereas the transmission spectrum of the second elastic body 12b has a wavelength of light emitted from the light emitting element 15a. It has the property of not transmitting light.

  The light emitting element 15a is, for example, a near-infrared LED (Light Emitting Diode) having a peak wavelength in the range of λ = 700 nm to 1100 nm, and the light receiving element 15b is near the wavelength that the near-infrared LED emits. A phototransistor that receives infrared light can be used. At this time, the first elastic body 12a can use a near-infrared transmitting gel that transmits light having a wavelength in the near-infrared region, and the second elastic body 12b has a wavelength in the near-infrared region. A near infrared absorbing gel that absorbs light can be used.

[Description of optical path in elastic body: Fig. 1]
Due to the transmittance characteristics of each elastic body described above, in FIG. 1, a part of the light emitted from the light emitting element 15 a passes through the first elastic body 12 a (arrow A in the figure), and external contact occurs. After passing through the surface 16 and proceeding into the living body 20, passing through the living body 20 (arrow B in the figure), after passing through the external contact surface 16 again and returning into the first elastic body 12a (in the figure) Arrow C), and is detected by the light receiving element 15b.

  At this time, the light that has traveled into the living body 20 changes in light intensity in the near-infrared region corresponding to the local blood volume due to a minute change in blood vessel volume caused by blood pressure.

  On the other hand, of the light emitted from the light emitting element 15a, the other part of the light passes through the first elastic body 12a (arrow a in the figure), is reflected by the external contact surface 16, and the first elastic body It enters the boundary surface 12c between 12a and the second elastic body 12b (arrow b in the figure). The light that has entered the boundary surface 12c and travels to the second elastic body 12b is absorbed by the low transmittance of the second elastic body 12b, the light intensity is reduced, and the light intensity of the light that returns to the first elastic body 12a Is greatly attenuated (arrow c in the figure). Therefore, when the light passing through the first elastic body 12a is incident on the boundary surface 12c while being reflected by the external contact surface 16 or the like, it is absorbed by the transmittance characteristic of the second elastic body 12b and the light intensity is reduced. Therefore, of the light emitted from the light emitting element 15a, the light reaching the light receiving element 12b is limited to only light traveling on the optical path passing through the living body 20, as indicated by A, B, and C in the figure. it can.

  As a result, the light received by the light receiving element 15b can eliminate noise components that are repeatedly reflected in the first elastic body 12a, and the biological information obtained by passing through the living body 20 has a high S / N. The ratio can be detected.

  The passage of light described above acts in substantially the same manner regardless of the magnitude of pressure applied by pressing the living body. As shown in FIG.1 (b), the light which injected into the boundary surface 12c among the lights radiate | emitted from the light emitting element 15a is absorbed by the low transmittance | permeability with which the 2nd elastic body 12b is equipped, and light intensity falls, The light intensity of the light returning to the first elastic body 12a is greatly attenuated.

  The first elastic body 12a is compressed by being pressed, and the optical path is changed by this compression. However, since the first elastic body 12a is thinner than the entire thickness of the elastic body 12, the light emitting element 15a The amount of change in the optical path lengths of the optical paths A, B, and C from the living body 20 to the light receiving element 15b is small, and the change in the light intensity of the detection light accompanying the change in the optical path length can be suppressed to a small level.

  In the case of a biological information detection sensor that detects a change in the surface of the living body due to a blood vessel change of an artery (for example, vibration of the skin immediately above the blood vessel) as a change in the volume of the blood vessel, as a light source used for the light emitting element 15a. A light source that does not have emission characteristics in the near infrared region can also be selected.

  In this case, for example, the change in the volume of the blood vessel is detected by a change in the amount of light in the optical path that is emitted from the light emitting element 15a, reflected by the external contact surface 16 in contact with the living body 20, and reaching the light receiving element 15b. The change in the amount of light in the optical path from the light emitting element 15a to the light receiving element 15b through the transmission path becomes noise.

  Therefore, from the viewpoint of improving the S / N ratio of the signal detected by the light receiving element 15b, the scope of the present invention does not select the type of light source used for the light emitting element 15a.

[Explanation of the second to sixth embodiments: FIGS. 3 to 7]
Next, 2nd form-6th form of the biological information detection sensor of this invention is demonstrated using FIGS. In addition, description is abbreviate | omitted here about the part which is common in the 1st form already demonstrated.

[Explanation of the second embodiment: FIG. 3]
The 2nd form of this invention is the structure which supports the photoelectric sensor 15 with which the biometric information detection sensor 10 is equipped with the auxiliary | assistant board | substrate 15c. In FIG. 3, the auxiliary substrate 15c is a flexible substrate, and is connected to the substrate 11 by the wiring 13, and the photoelectric sensor 15 is electrically connected to the outside through the auxiliary substrate 15c. . Further, the auxiliary substrate 15c can be constituted by, for example, an FPC (flexible printed circuit) substrate. In this case, the FPC board itself can also serve as the wiring 13.

  When the additional pressure detecting elastic body 12 is made of a material having a weak physical holding force such as a gel material, the light emitting element 15a and the light receiving element 15b, which are the photoelectric sensors 15, are placed in the additional pressure detecting elastic body 12. In this case, it may be difficult to determine the positions of these elements. According to this configuration, by using the auxiliary substrate 15c, by increasing the contact area with the elastic body 12 for detecting the additional pressure, Positioning of the photoelectric sensor 15 with respect to the additional pressure detecting elastic body 12 can be facilitated.

[Description of the third embodiment: FIG. 4]
The third aspect of the present invention is a configuration in which an optical path is formed by regions of different transmittances of the additional pressure detecting elastic body 12 included in the biological information detection sensor 10. In FIG. 4, the additional pressure detecting elastic body 12 has a first region 12a having a high transmittance and a low absorptance with respect to the wavelength of light emitted from the light emitting element 15a, and a second region having a low transmittance and a high absorptance. With the region 12b, an optical path 70 from the light emitting element 15a through the living body 20 to the light receiving element 15b is formed.

  This optical path 70 can be formed by adjusting the transmittance of the elastic body 12 for detecting additional pressure, and includes a region extending from the light emitting element 15a to the external contact surface 16 and a region extending from the external contact surface 16 to the light receiving element 15b. Including.

  Of course, the shape of the optical path 70 is not limited to that shown in FIG. The light emitted from the light emitting element 15a only needs to have a path that reaches the living body 20 and reaches the light receiving element 15b, and can be freely selected depending on the arrangement relationship between the light emitting element 15a and the light receiving element 15b.

[Description of the fourth embodiment: FIG. 5]
According to the fourth embodiment of the present invention, the area of the additional pressure detection elastic body 12 of the biological information detection sensor 10 is provided, and the transmittance with respect to the emission wavelength of the light emitting element 15a is external to the additional pressure detection elastic body 12 from the substrate 11 side. In this configuration, the elastic body changes gradually or in multiple stages toward the contact surface 16. FIG. 5 shows an example of the fourth embodiment.

  In this embodiment, at least the transmittance at the position of the photoelectric sensor 15 and the transmittance that makes the light intensity of the emitted light on the external contact surface 16 of the additional pressure detecting elastic body 12 sufficiently large for detection by the light receiving element 15b, To do.

  Of the light emitted from the light emitting element 15a, the light traveling in the direction of a small transmittance (on the substrate 11 side) with respect to the light emitting wavelength of the light emitting element 15a (the direction of the large transmittance with respect to the light emitting wavelength of the light emitting element 15a (external) It is greatly attenuated compared to the light traveling to the contact surface 16).

  As a result, similarly to the above-described embodiments, the intensity of light traveling toward the substrate 11 can be reduced to reduce noise.

[Explanation about the fifth embodiment: FIG. 6]
In the fifth embodiment of the present invention, light that travels toward the substrate 11 out of light emitted from the light emitting element 15a is absorbed by the absorption layer 82 provided on the auxiliary substrate 81 that holds the photoelectric sensor 15, and the living body 20 is absorbed. In this configuration, light reaching the light receiving element 15b through an optical path other than the optical path passing therethrough is suppressed.

  6A is a cross-sectional view, and FIG. 6B is a front view at the position of the photoelectric sensor 15.

  The photoelectric sensor 15 is attached to the auxiliary substrate (or FPC substrate) 81 to be held in the elastic body 12 for detecting additional pressure. The auxiliary substrate 81 is connected to the substrate 11 by the wiring 13. The auxiliary substrate 81 is provided with an absorption layer 82 having a characteristic of absorbing the wavelength of light emitted from the light emitting element 15a on the surface opposite to the substrate 11 (surface facing the living body 20). The absorption layer 82 absorbs light that travels toward the substrate 11 out of the light emitted from the light emitting element 15a by the same action as the second elastic body 12b provided in the above-described embodiment, and other than the optical path that passes through the living body 20. The light reaching the light receiving element 15b through the optical path is suppressed.

  Note that the size of the auxiliary substrate 81 is not limited to the example shown in FIG. It can be freely selected according to the shape and size of the substrate 11 and the elastic body 12 for detecting additional pressure.

[Explanation about the sixth embodiment: FIG. 7]
In the sixth embodiment of the present invention, light traveling from the light emitting element 15a to the light receiving element 15b is absorbed by the absorption layer 91 provided between the light emitting element 15a and the light receiving element 15b in the elastic body 12 for detecting the applied pressure. Thus, the light reaching the light receiving element 15b through an optical path other than the optical path passing through the living body 20 is suppressed.

  7A shows a cross-sectional view, and FIG. 7B shows a front view at the position of the photoelectric sensor 15.

  In the additional pressure detecting elastic body 12, an absorption layer 91 having a low transmittance with respect to the emission wavelength of the light emitting element 15a and a high absorption rate is provided between the light emitting element 15a and the light receiving element 15b, and the other regions have already been described. Similarly to the first elastic body 12a shown in the form, the light-emitting element 15a is an elastic body having a high transmittance with respect to the emission wavelength.

  The absorption layer 91 absorbs light that travels toward the substrate 11 out of the light emitted from the light emitting element 15a by the same action as the second elastic body 12b included in the above-described form, and other than the optical path that passes through the living body 20. Light reaching the light receiving element 15b through the optical path is suppressed.

  The size of the absorption layer 91, such as the width, is not limited to the example shown in FIG. It can be freely selected depending on the shape and size of the substrate 11 and the additional pressure detecting elastic body 12, the arrangement relationship between the light emitting element 15a and the light receiving element 15b, and the like.

[Description of Blood Pressure Measuring Device: FIGS. 8 to 15]
Next, a blood pressure measurement device including the biological information detection sensor of the present invention will be described with reference to FIGS.

  FIG. 8 shows a schematic outer shape of the blood pressure measurement device, and FIG. 9 shows a schematic shape with a part of the blood pressure measurement device cut out. 8 and 9, the blood pressure measurement device 30 includes a frame composed of an upper frame 31 and a lower frame 32, and a mat 36 is provided on the upper frame 31 for placing a subject's arm when blood pressure is measured. It is done. In addition, the blood pressure measurement device 30 includes a frame that forms an arm 35 constituted by the middle frame 33 and the front frame 34. This frame is provided with a lift mat 37 for lifting a blood pressure measurement part (wrist) toward the photoelectric sensor 10 provided inside the tip of the arm 35 while placing a blood pressure measurement part such as a wrist part of the subject at the time of blood pressure measurement. It is done.

  The photoelectric sensor 10 is provided at the tip of the arm 35 on the inner side facing the lift mat 37. In addition, a slide mechanism that slides the photoelectric sensor 10 in the lateral direction with respect to the arm 35 in order to perform lateral alignment with respect to the blood pressure measurement unit (wrist) placed on the lift mat 37 at the tip of the arm 35. 51 is provided.

  In the slide mechanism 51, the knob 52 and the photoelectric sensor 10 are interlocked, and the photoelectric sensor 10 can be aligned by picking the knob 52 and moving it in the lateral direction. Further, the slide mechanism 51 can be slid only when the release button (release lever) 53 is operated in a state in which the slide is always stopped.

  Inside the middle frame 33 and the front frame 34 are provided a motor 41 that moves the lift mat 37 up and down, a lift drive shaft 42, a lift table 43, a drive circuit board 45, and the like. Drive control is performed based on a control signal from a control circuit mounted on a control circuit board 44 provided inside.

  Further, the control circuit board 44 is a circuit that performs calculation processing for obtaining blood pressure based on drive control of the light emitting element 15 a of the photoelectric sensor 10, received light intensity received by the light receiving element 15 b, and pressure change obtained by the pressure sensor 14. A circuit configuration for displaying the configuration and the obtained blood pressure value on the internal display device 61 or the external display device 62 is provided.

  The built-in display device 61 can be provided at an arbitrary position such as the arm portion 35 or each frame portion of the blood pressure measurement device 30. In addition, the external display device 62 and the blood pressure measurement device 30 are not limited to the configuration in which the external connection device 62 is connected by the wiring 63. For example, a configuration in which wireless control is performed by short-range communication such as Bluetooth or IrDA (infrared data communication) It is good.

  Further, the external display device 62 may be configured to include an input unit 64 for inputting each control such as ON / OFF of the blood pressure measurement device 30, measurement start, and measurement stop.

  FIG. 10 is a configuration example of the biological information detection sensor 10, FIG. 10A is a cross-sectional view, and FIG. 10B is a front view of the position of the photoelectric sensor. This biological information detection sensor is a configuration example corresponding to the second embodiment described above.

  The biological information detection sensor 10 includes a pressure sensor 14 on a substrate 11 and includes a first elastic body 12a and a second elastic body 12b covered with a polyurethane film 19, and is pressed by the two elastic bodies. The additional pressure detecting elastic body 12 is transmitted to the pressure sensor 14. A light emitting element 15a and a light receiving element 15b provided in the FPC 17 are disposed at the position of the boundary surface 12c between the first elastic body 12a and the second elastic body 12b.

  The FPC 17 is supported by the FPC backing plate 18 and is stably held at the installation position in the additional pressure detecting elastic body 12. The substrate 11 includes a connector 11a for connecting the pressure sensor 14, the light emitting element 15a, and the light receiving element 15b to the outside. The substrate 11 sends the detection signal of the pressure sensor 14 and the detection signal of the light receiving element 15b to the outside, and the light emitting element 15a. Drive current from outside.

  The blood pressure measurement device 30 drives the lift drive shaft 42 by the motor 41 in accordance with a control command from the control circuit, moves the lift table 43 up and down, and attaches the wrist placed on the lift mat 37 to the opposing surface of the arm 35. The measurement part is raised toward the biological information detection sensor 10, the measurement position of the wrist is brought into contact with the external contact surface of the biological information detection sensor 10, and the lift mat 37 is raised to press the measurement site. Then, based on the volume pulse wave information and pressure information detected by the pressure sensor 14 and the photoelectric sensor 15 of the biological information detection sensor 10, the control circuit determines the blood pressure value of the subject.

  Therefore, it is possible to easily and reliably perform blood pressure measurement work that is less likely to cause discomfort than conventional blood pressure measurement devices using a cuff, obtain highly accurate measurement results, and further reduce the size of the device. Can be realized.

[Description of functional configuration of blood pressure measurement device]
Next, the functional configuration of the blood pressure measurement device 30 will be described. FIG. 11 is a block diagram illustrating an example of a functional configuration of the blood pressure measurement device according to the present invention. As shown in FIG. 11, the blood pressure measurement device 30 includes an overall control unit 100, a pressure detection unit 111, a pulse wave detection unit 112, a drive unit 113, an analog / digital conversion unit (A / D) 114, The digital-analog conversion part (D / A) 115, the alerting | reporting part 116, the interface (I / F) 117, the display part 118, and the operation part 119 are comprised. The overall control unit 100 includes a pressure measurement unit 101, an extraction unit 102, a determination unit 103, a drive control unit 104, a storage unit 105, an acquisition unit 106, and a blood pressure value determination unit 107.

  The overall control unit 100 comprehensively controls the entire blood pressure measurement device 30. The overall control unit 100 is configured by, for example, a CPU or an MPU (Micro Processing Unit). The overall control unit 100 can be provided on the control circuit board 44 described above. The pressure measurement unit 101 in the overall control unit 100 measures the pressing force applied to the measurement site detected by the pressure detection unit 110 described later. The extraction unit 102 extracts the pulse rate and the pulse wave amplitude value of the subject from the volume pulse wave information including the pulse wave detected by the pulse wave detection unit 111 described later. The determination unit 103 determines whether or not the pulse rate and pulse wave amplitude value extracted by the extraction unit 102 are within a predetermined range set in advance in the overall control unit 100.

  The drive control unit 104 in the overall control unit 100 controls the drive operation of the drive unit 113 described later. For example, the drive control unit 104 controls the drive unit 113 based on predetermined operation parameters so as to detect the volume pulse wave information and the pressure information by performing an optimal pressing operation for the ascending / descending mechanism. The drive control unit 104 controls the drive unit 113 to perform the pressing operation on the wrist measurement site by a lift mechanism a plurality of times with different pressing patterns, and based on the obtained volume pulse wave information and pressure information, respectively. The predetermined operation parameter described above may be calculated. Thereby, for example, regardless of age or sex, it is possible to perform an optimal pressing operation even in blood pressure measurement work for different measurement sites for each subject.

  For example, the predetermined operation parameter may be acquired from the outside by the acquisition unit 106 via the interface 117 described later.

  The memory | storage part 105 memorize | stores the blood pressure value determined by the blood pressure value determination part 107 mentioned later. The storage unit 105 temporarily or permanently stores various information input to the overall control unit 100 and various types of information generated by the overall control unit 100. As the storage unit 105, an electrically rewritable semiconductor storage device such as an EEPROM or a magnetic storage device such as a hard disk can be used.

  The acquisition unit 106 acquires the physique information of the subject input to the overall control unit 100 from the operation unit 119 or the like via an interface 117 described later.

  The blood pressure value determination unit 107 determines the blood pressure value of the subject based on the detection results detected by the pressure detection unit 110 and the pulse wave detection unit 111 described later.

  In addition, the blood pressure value determination unit 107 calculates a blood pressure value based on volume pulse wave information and pressure information obtained by a pressing process and a decompression process on the measurement site, respectively. The calculated blood pressure value may be averaged to determine the blood pressure value of the subject.

  When determining the blood pressure value, the blood pressure value can be determined in either the pressing process or the decompression process. Therefore, by averaging the blood pressure values obtained in both processes and determining the final blood pressure value, high accuracy is obtained. Blood pressure measurement can be realized.

  The pressure detection unit 111 detects, for example, a pressing force on the measurement site of the upper arm portion of the subject. The pressure detection unit 111 is configured by the pressure sensor 14. The pulse wave detector 112 detects the pulse wave of the artery at the measurement site. Therefore, when the measurement site is on the wrist, the pulse wave of the wrist is detected. The pulse wave detection unit 112 is configured by the photoelectric sensor 15.

  Information such as the pressing force and the pulse wave detected by the pressure detection unit 111 and the pulse wave detection unit 112 is input to the analog / digital conversion unit 114, and the analog / digital conversion unit 114 converts the analog signal into a digital signal. It is converted and input to the overall control unit 100. The drive unit 113 is driven based on a drive control signal output from the overall control unit 100 and converted from a digital signal to an analog signal by the digital / analog conversion unit 115. The drive unit 113 is configured by the motor 41 described above.

  The notification unit 116 notifies a subject or the like of information related to the blood pressure value determined by the blood pressure value determination unit 107 and various information related to the blood pressure measurement device 30. Examples of the information notified by the notification unit 116 include information on whether or not the pulse rate and the pulse wave amplitude value of the subject determined by the determination unit 103 are within a predetermined range. In addition, the notification unit 116 notifies information such as whether or not the blood pressure measurement by the blood pressure measurement device 30 is normally performed. Of course, notification indicating that the blood pressure is being measured or notification of how long the measurement is completed may be performed.

  For example, the notification unit 116 may be configured by a speaker, a vibration device, a display device, or the like, and may notify various information by vibration or display. In addition, when the alerting | reporting part 116 is comprised with a speaker, various information is alert | reported by an alarm sound or a sound.

  The interface 117 outputs information on the blood pressure value determined by the blood pressure value determining unit 107 to, for example, a printing apparatus (not shown). The interface 117 transmits and receives various types of information between the overall control unit 100 and the display unit 118 and the operation unit 119. Transmission / reception of various information by the interface 117 is performed by wire or wireless.

  The display unit 118 displays images such as characters and graphics based on various information output from the overall control unit 100 via the interface 117. The display unit 118 can be configured by a display. The operation unit 119 is operated to input various information for the blood pressure measurement device 30 by a subject or the like. The operation unit 119 includes a push button switch, a keyboard, and other known input devices.

  Next, the blood pressure measurement process of the blood pressure measurement device 30 will be described. FIG. 12 is a flowchart showing an example of blood pressure measurement processing of the blood pressure measurement device of the present invention. In the following description, the same portions as those already described are denoted by the same reference numerals and description thereof is omitted. As shown in FIG. 12, first, input information instructing “device activation” is input from the operation unit 119 via the interface 117 to the overall control unit 100 by a subject using the blood pressure measurement device 30, for example. The acquisition unit 106 acquires input information. Then, the overall control unit 100 resets and initializes the settings of the blood pressure measurement device 30 based on the acquired input information (step S1).

  In this case, for example, the subject places the upper arm portion on the mat 36 of the blood pressure measurement device 30 with the living body surface of the upper arm portion exposed, and places the wrist on the lift mat 37.

  Next, for example, input information instructing “start measurement” is input to the overall control unit 100 from the operation unit 119 via the interface 117 by the subject or the like, and the acquisition unit 106 acquires this input information. Then, the drive control unit 104 controls the drive unit 113 (motor 41) to raise the lift table 43 and the lift mat 37 so that the measurement site of the wrist is brought into contact with the external contact surface 16 of the biological information detection sensor 10. The measurement site is pressed (step S2).

  When the measurement site is pressed, the pressure detection unit 111 (pressure sensor 14) detects the pressing force, and the pulse wave detection unit 112 (photoelectric sensor 15) detects the pulse wave of the radial artery of the wrist. The detection result (detection signal) is input to the overall control unit 100 via the analog / digital conversion unit 114. The pressure waveform of the pressing force detected by the pressure detection unit 111 and the volume pulse wave waveform of the pulse wave detected by the pulse wave detection unit 112 are as follows.

  FIG. 13 is a waveform diagram showing a pressure waveform detected by the blood pressure measurement device 30. FIG. 14 is a waveform diagram showing a volume pulse wave waveform detected by the blood pressure measurement device 30. As shown in FIG. 13, the pressure waveform 300 of the pressing force detected by the pressure detector 111 indicates that the pressure (mmHg) represented on the vertical axis changes with the passage of time (sec) represented on the horizontal axis. ing.

  Here, the pressure waveform 300 detected by the pressure detection unit 111 when the measurement site is gradually pressed by the lift table 43 and the lift mat 37 driven by the drive unit 113 over a period of about 20 seconds. Appears.

  Further, as shown in FIG. 14, the volume pulse waveform 301 of the pulse wave detected by the pulse wave detector 112 has a volume pulse wave intensity (A.V.) expressed on the vertical axis as time (sec) expressed on the horizontal axis elapses. U.), that is, the pulse wave amplitude value changes.

  Here, the pulse wave detection unit 112 detects when the wrist, which is the measurement site, is gradually pressed over a period of about 20 seconds by the lift table 43 and the lift mat 37 driven by the drive unit 113. A volume pulse waveform 301 is shown.

  During the pressing operation on the measurement site in step S2, the overall control unit 100 determines whether or not the pulse wave is detected based on the detection signal from the pulse wave detection unit 112 (step S3). When it is determined that no pulse wave is detected (step S3: No), the drive control unit 104 continues the pressing operation in step S2.

  On the other hand, when it is determined that the pulse wave has been detected (step S3: Yes), the drive control unit 104 controls the drive unit 113 to further press the measurement site with the lift table 43 and the lift mat 37 (step S4). ).

  During the pressing operation on the measurement site in step S4, the overall control unit 100 determines whether or not the pulse wave amplitude value of the pulse wave is increasing based on the detection signal from the pulse wave detection unit 111 (step). S5). If it is determined that the pulse wave amplitude value has not increased (step S5: No), the drive control unit 104 continues the pressing operation in step S4. On the other hand, when it is determined that the pulse wave amplitude value is increasing (step S5: Yes), the storage unit 105 averages the pressure at the time when the pulse wave amplitude value is maximum based on the detection signal from the pressure detection unit 111. Stored as a blood pressure value (Pm) (step S6).

  Then, the overall control unit 100 controls the drive unit 113 with the drive control unit 104 and further presses the measurement site with the lift table 43 and the lift mat 37 (step S7).

  During the pressing operation on the measurement site in step S7, the overall control unit 100 determines whether or not the pulse wave amplitude value of the pulse wave has become minute based on the detection signal from the pulse wave detection unit 112 (step). S8).

  When it is determined that the pulse wave amplitude value is not very small (step S8: No), the drive control unit 104 continues the pressing operation in step S7. On the other hand, when it is determined that the pulse wave amplitude value has become very small (step S8: Yes), the pressure at the time when the pulse wave amplitude value is very small is stored by the storage unit 105 based on the detection signal from the pressure detecting unit 111. Stored as a value (Ps) (step S9).

  Then, the overall control unit 100 calculates the minimum blood pressure value (Pd) by the blood pressure value determination unit 107 based on the average blood pressure value (Pm) and the maximum blood pressure value (Ps) stored in the storage unit 105 (step S10). ).

The minimum blood pressure value (Pd) can be estimated from the average blood pressure value (Pm) and the maximum blood pressure value (Ps). The calculation process of the minimum blood pressure value (Pd) in step S10 is performed by, for example, the blood pressure value determination unit 107 using the following mathematical formula.
Pd = (3 × Pm−Ps) / 2

  When the diastolic blood pressure value (Pd) is calculated in step S10, the overall control unit 100 controls the drive unit 113 by the drive control unit 104 to move the lift mat 37 in the direction opposite to the pressing direction (opening direction). The pressing operation on the part is terminated (step S11).

  After the process of step S <b> 11, the subject removes his / her wrist from the wrist mat 37 and detaches the forearm from the mat 36.

  Based on the blood pressure value determined by the blood pressure value determination unit 107 and the pulse rate extracted by the extraction unit 102, the overall control unit 100 outputs information on these measurement results to the display unit 118 via the interface 117, The display unit 118 displays the subject's maximum blood pressure value (Ps), minimum blood pressure value (Pd), and pulse rate in the measurement result (step S12). Thereby, a series of blood pressure measurement processing according to this flowchart is completed.

  In addition to the display process in step S12 or in place of the display process, for example, information related to the measurement result may be output as audio by the notification unit 116 or printed out by a printing apparatus (not shown). Further, the measurement site is not limited to the wrist or the upper arm.

  Thus, according to the blood pressure measurement process in the blood pressure measurement device 30, the blood pressure value can be determined by mechanically pressing the measurement site of the subject mechanically by raising and lowering the lift mat 37 instead of the cuff. Thus, it is possible to easily perform blood pressure measurement work that is less likely to cause discomfort, and to obtain highly accurate measurement results.

  Note that the pressing operation on the measurement site in Steps S2, S4, and S7 is performed by controlling the drive unit 113 based on a predetermined operation parameter by the drive control unit 104 of the overall control unit 100. At this time, the pressure waveform detected by the pressure detection unit 111 is as follows.

  FIG. 15 is a waveform diagram showing an example of a pressure waveform detected by a series of pressing operations performed based on predetermined operation parameters. As shown in FIG. 15, first, the pressing operation is started by the drive control unit 104, for example, at the time t0, and the biological information detection sensor 10 comes into contact with the measurement site at the time t1, and the pressure detection unit 111 presses the pressing force. Is detected, and the operation of the drive unit 113 is controlled so that the detected pressure gradually increases until the time t2, and the measurement site is slowly pressed by the lift mat 37. The pressing force at this time is, for example, about 5 mmHg / sec, and the time from t1 to t2 is preferably about 2 seconds.

  Next, the drive control unit 104 controls the operation of the drive unit 113 such that the pressure detection unit 111 detects a sudden increase in pressing force between t2 and t3, for example, and the lift mat 37 is lifted. To rapidly press the measurement site. The pressing force at this time is, for example, about 45 mmHg / sec, and the time from t2 to t3 is preferably about 1 second.

  Then, the drive control unit 104 performs the period from the time point t3 to the mean blood pressure value (Pm) detection time point (pulse wave amplitude value maximum time point) t4 and the maximum blood pressure value (Ps) detection time point (pulse wave amplitude value minute time point) t5. In addition, the operation of the driving unit 13 is controlled so that the pressing force detected by the pressure detection unit 111 gradually increases, and the measurement site is slowly pressed. The pressing force at this time is, for example, about 5 mmHg / sec, and the time from t3 to t5 is preferably about 20 seconds.

  Then, the drive control unit 104 controls the operation of the drive unit 113 so that the pressing force detected by the pressure detection unit 111 gradually increases from the time t5 to the time t6, for example, and the lift mat 37 is lifted. Slowly press the measurement site. The pressing force at this time is, for example, about 5 mmHg / sec, and the time from t5 to t6 is preferably about 2 seconds.

  In the example described with reference to the pressure waveform 300 and the volume pulse waveform 301 in FIGS. 13 and 14, for example, a case where the pressing force on the measurement site is about 7 to 8 mmHg / sec is shown. In general, in order to guarantee the accuracy of blood pressure value determination in blood pressure measurement, it is preferable to reduce the pressure change in the pulse cycle, but for example, increasing the pressing force using information such as an estimation algorithm Is possible. For this reason, in the example shown in FIG.13 and FIG.14, it is suggested that the blood pressure measurement apparatus 30 can perform a pressing operation rapidly.

  In addition, since the blood pressure value can be measured by pressing the biological information detection sensor 10 against the measurement site, for example, the contact area between the biological information detection sensor 10 and the measurement site is reduced to generate congestion in the measurement site. Can be effectively prevented.

  Further, since the elastic body for detecting the additional pressure of the biological information detecting sensor 10 can be configured by filling the bag body with the gel-like pressure guiding medium, the contact pressure between the elastic body for detecting the additional pressure 12 and the measurement site. Can be accurately transmitted to the pressure measuring means (pressure sensor 14), and the pressure can be measured accurately.

  Further, since the pulse rate and the pulse wave amplitude value are extracted to determine whether or not they are within a predetermined range, and the determination result can be notified by the notification unit 116, for example, the blood pressure measurement work is performed normally. Information such as whether or not it is being performed can be notified to the subject, and the pulse rate of the subject can be measured. In addition, since such information can be notified by alarm sound, voice, vibration, display, etc., the subject can easily check information such as whether or not blood pressure measurement work is normally performed.

  The biological information detection sensor of the present invention can be applied to a pulse measuring device in addition to a blood pressure measuring device.

It is a figure for demonstrating the 1st form of the biometric information detection sensor of this invention. It is a characteristic view of the transmittance | permeability (light reception intensity) with which the elastic body for additional pressure detection of the biological information detection sensor of this invention is provided. It is a figure for demonstrating the 2nd form of the biometric information detection sensor of this invention. It is a figure for demonstrating the 3rd form of the biometric information detection sensor of this invention. It is a figure for demonstrating the 4th form of the biometric information detection sensor of this invention. It is a figure for demonstrating the 5th form of the biometric information detection sensor of this invention. It is a figure for demonstrating the 6th form of the biometric information detection sensor of this invention. It is a figure which shows schematic outer shape of the blood-pressure measuring apparatus of this invention. It is a figure which shows the schematic shape which notched some blood pressure measuring devices of this invention. It is a figure for demonstrating the example of 1 structure of the biometric information detection sensor of this invention. It is a block diagram which shows an example of a functional structure of the blood-pressure measuring apparatus of this invention. It is a flowchart which shows an example of the blood pressure measurement process of the blood pressure measurement apparatus of this invention. It is a wave form diagram which shows the pressure waveform detected by the blood pressure measuring device. It is a wave form diagram which shows the volume pulse wave waveform detected by the blood pressure measuring device. It is a wave form chart showing an example of a pressure waveform detected by a series of press operations performed based on a predetermined operation parameter. It is a figure which shows the example of 1 structure of a biometric information detection sensor. It is a figure which shows the other structural example of a biometric information detection sensor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Living body information detection sensor 11 Board | substrate 12 Elastic body for added pressure detection 12a 1st elastic body 12b 2nd elastic body 12c Interface 13 Wiring 14 Pressure sensor 15 Photoelectric sensor 15a Light emitting element 15b Light receiving element 15c Auxiliary board 16 External contact surface 17 FPC
18 FPC backing substrate 19 Polyurethane film 20 Living body 70 Optical path 81 Substrate 82 Absorbing layer 91 Absorbing layer 30 Blood pressure measuring device 31 Upper frame 32 Lower frame 33 Middle frame 34 Front frame 35 Arm 36 Mat 37 Lift mat 41 Motor 42 Lift drive shaft 43 Lift Table 44 Control circuit board 45 Drive circuit board 51 Slide mechanism 52 Knob 53 Release lever (release button)
61 Internal Display Unit 62 External Display Unit 63 Wiring 64 Input Means 100 Overall Control Unit 101 Pressure Measurement Unit 102 Extraction Unit 103 Determination Unit 104 Drive Control Unit 105 Storage Unit 106 Acquisition Unit 107 Blood Pressure Value Determination Unit 111 Pressure Detection Unit 112 Pulse Wave Detection Unit 113 Drive unit 114 Analog / digital conversion unit 115 Digital / analog conversion unit 116 Notification unit 117 Interface 118 Display unit 119 Operation unit

Claims (9)

A pressure sensor disposed on the substrate;
An elastic body for detecting an additional pressure that is disposed on the substrate and transmits a pressure applied to the pressure sensor;
A photoelectric sensor including a light emitting element and a light receiving element provided in the elastic body for detecting the additional pressure,
The elastic body for detecting the additional pressure includes a region where the transmittance with respect to the emission wavelength of the light emitting element is different, and the transmittance of the region between the substrate and the photoelectric sensor is the elasticity for detecting the photoelectric sensor and the additional pressure. The biological information detection sensor characterized by being smaller than the transmittance | permeability between the external contact surfaces of a body. The region provided in the elastic body for detecting the additional pressure is at least two elastic bodies having different transmittances with respect to the emission wavelength of the light emitting element,
In order from the substrate side toward the external contact surface of the additional pressure detecting elastic body, the elastic body having a small transmittance with respect to the light emitting wavelength of the light emitting element, the photoelectric sensor, and the light emitting wavelength of the light emitting element The biological information detection sensor according to claim 1, wherein an elastic body having a large transmittance is arranged in a layered manner. The region provided in the elastic body for detecting the additional pressure is a first elastic body and a second elastic body that have different transmittances with respect to an emission wavelength of the light emitting element,
A first elastic body having a large transmittance with respect to the light emission wavelength of the light emitting element is disposed on the outer contact surface side of the photoelectric sensor, and a second transmittance having a small transmittance with respect to the light emission wavelength of the light emitting element. The biological information detection sensor according to claim 1, wherein an elastic body is disposed between the substrate and the photoelectric sensor. The region with which the additional pressure detecting elastic body is provided is an elastic body in which the transmittance of the light emitting element with respect to the emission wavelength changes gradually or in multiple steps from the substrate side toward the external contact surface of the additional pressure detecting elastic body. ,
The transmittance at least at the position of the photoelectric sensor is a transmittance that makes the light intensity of the emitted light on the external contact surface of the additional pressure detecting elastic body sufficiently large for detection by the photoelectric sensor. The biological information detection sensor according to claim 1.   The additional pressure detection elastic body includes a region connecting the position of the external contact surface of the additional pressure detection elastic body for entering and exiting light with a living body, and the light emitting element or the light receiving element. The biological information detection sensor according to claim 1, wherein an optical path is formed by a region connecting the light-emitting element and the light-receiving element with a transmittance different from that of the region.   The photoelectric sensor is installed on a flexible substrate, and the flexible substrate is provided in the additional pressure detection elastic body, thereby holding the photoelectric sensor in the additional pressure detection elastic body. The biological information detection sensor according to any one of claims 1 to 5.   The biological information detection sensor according to any one of claims 2 to 6, wherein the elastic bodies having different transmittances have substantially the same elastic coefficient.   The biological information detection sensor according to any one of claims 2 to 7, wherein the additional pressure detection elastic body is a gel. A fixing means that has an inscribed portion that is inscribed in the living body of the subject, and fixes the living body through the inscribed portion;
Detection means that is movable relative to the fixing means, and that detects the volume pulse wave information relating to the volume pulse wave of the subject and pressure information relating to the pressing force by pressing the measurement site of the living body;
Driving means for pressing the detection means against the measurement site;
Blood pressure value determining means for determining a blood pressure value of the subject based on the volume pulse wave information and the pressure information detected by the detecting means,
9. The blood pressure measuring apparatus according to claim 1, wherein the detection means is the biological information detection sensor according to any one of claims 1 to 8.