JP4393571B2 - Biological information measuring device - Google Patents

Description

  The present invention relates to a biological information measuring device that detects biological information from a part of a living body such as a pinna of a human body.

  With the aging of society, dealing with adult lifestyle-related diseases has become a major social issue. It is recognized that long-term blood pressure data collection is very important, especially for diseases related to high blood pressure. From this point of view, various biological information measuring devices including blood pressure have been developed.

  2. Description of the Related Art Conventionally, there is a patient monitor device that is inserted into other parts of the external auditory canal or the external ear and is always worn as a device that measures biological information at the external ear (see, for example, Patent Document 1). In Patent Document 1, as a method for detecting a pulse wave or blood flow of an artery, scattered light scattered by an arterial body of a living body or blood cells in the artery is scattered by a light receiving element. A method for detecting pulse waves and blood flow from scattered light is disclosed. Here, the pulse, pulse wave, electrocardiogram, body temperature, arterial blood oxygen saturation, blood pressure, and the like can be calculated from the amounts of received infrared light and visible light scattered into the living body.

  Moreover, as an apparatus to be mounted on the ear canal or earlobe, there is an emergency information apparatus that includes wireless communication means and includes an arterial blood oxygen saturation sensor, a body temperature sensor, an electrocardiogram sensor, and a pulse wave sensor (for example, Patent Document 2). reference.).

  On the other hand, with regard to blood pressure measurement, blood pressure measurement devices based on pulsation waveforms of blood vessels are prominent along with blood pressure measurement devices using other methods such as the cuff vibration method and volume compensation method (for example, see Non-Patent Document 1). It is accepted as a method for measuring blood pressure.

In the present application, the name of the pinna is based on Non-Patent Document 2, and the name of the pinna cartilage is based on Non-Patent Document 3.
JP-A-9-128203 JP-A-11-128174 Kenichi Yamakoshi, Tatsuo Togawa, “Biological Sensors and Measuring Devices”, MM Japan Society / ME Textbook Series A-1, pages 39-52 Sobotta Illustrated Human Anatomy Volume 1 (Translation by Michio Okamoto), p. 126, Medical School, issued October 1, 1996 Sobotta Illustrated Human Anatomy Volume 1 (Translation by Michio Okamoto), p. 127, Medical School, issued October 1, 1996

  However, the pulse wave and blood flow detection methods using the light emitting element and the light receiving element are under development, and only experimental results are scattered, and the measurement results contain a lot of noise. When receiving scattered light scattered by an artery of a living body or blood cells in the artery among light irradiated to a living body by a light emitting element, the present inventors receive a lot of noise light on the light receiving element due to body movement. Found to join. That is, a housing that houses a sensor composed of a light emitting element and a light receiving element is mostly arranged so as to be incorporated in the cuff or separated from the cuff while utilizing tightening due to the expansion of the cuff. Since the cuff pressurizes the inside and further depressurizes, the shape of the cuff changes greatly. For this reason, the positional relationship between the light emitting element, the light receiving element, and the living body slightly changes, so that the direction of the reflected light and the amount of the reflected light also change variously. It was a great hindrance to wave detection.

  Therefore, the present invention provides a plurality of light receiving elements and uses each light receiving signal measured by each light receiving element to reduce a body motion noise or select a light receiving signal with less noise to obtain highly accurate pulse wave information. For the purpose.

  In order to achieve the above object, the biological information measuring apparatus according to the present invention is provided with at least one light emitting element and two or more light receiving elements.

The biological information measuring apparatus according to the first aspect of the present invention is a housing having one surface that is translucent, and at least one that emits emitted light to the outside of the housing through the one surface. A light emitting element, two or more light receiving elements that are disposed inside the housing and receive scattered light scattered from outside the housing through the one surface, and the light receiving elements measured And a third measured value processing means for selecting a received light signal having a maximum evaluation function value composed of an alternating current component and a direct current component of the waveform among the received light signals.

  As described above, by providing two or more light receiving elements, even if the shape of the cuff changes greatly and the direction of reflected light and the amount of reflected light change variously, Some measure light reception signals with little change. Therefore, among the light receiving signals measured by the light receiving elements, the light receiving signal with the least body motion noise is selected using the evaluation function value composed of the alternating current component and the direct current component of the waveform as an index. Wave information can be obtained.

In the biological information measuring apparatus according to the first aspect, when the third measurement value processing means uses the evaluation function as the alternating current component and selects the received light signal having the maximum value of the alternating current component among the received light signals. Is included. Among the received light signals, the waveform AC component includes biological information such as pulse wave information, while the waveform component DC component includes noise and stray light information. Therefore, the light reception signal with the least body motion noise is selected by selecting the light reception signal having the maximum value with the evaluation function as an AC component.

Alternatively, in the biological information measuring apparatus according to the first invention , the third measurement value processing means sets the evaluation function to (the AC component / the DC component), and among the received light signals, the AC component / the DC component. ) Includes the case where the received light signal having the maximum value is selected. By selecting the received light signal having the maximum value as the evaluation function (alternating current component / direct current component), the received light signal with less body motion noise is selected.

Alternatively, in the biological information measuring apparatus according to the first invention , the third measurement value processing means uses an evaluation function (a component in a specific frequency range of the AC component / the DC component), and among the received light signals, This includes the case of selecting a received light signal having a maximum value of the specific frequency range component / the direct current component) among the alternating current components. The AC component contains a lot of biological information such as pulse wave information, but also includes noise. Among these, the alternating current component derived from biological information is contained in 0.1-10 Hz, for example. On the other hand, the AC component of noise is large on the low frequency side of 0.1 Hz or less, and is also included on the high frequency side exceeding 10 Hz. Therefore, since there are many AC components related to biological information with respect to the AC component of the noise in the AC component of the specific frequency range, for example, in the frequency range of 0.5 to 10 Hz, the evaluation function (the component of the specific frequency range in the AC component / By selecting the light receiving signal having the maximum value as the DC component), the light receiving signal with less body movement noise is selected.

In the first invention , it is preferable to provide a separation wall between the light emitting element and the light receiving element in the housing. By providing the separation wall, stray light can be reduced, and the proportion of scattered light in the living body out of the light received by the light receiving element can be increased.

In the first invention , the light emitting element and the light receiving element are preferably arranged on the same paraboloid, the same spherical surface, or the same hyperboloid. By arranging the light emitting element and the light receiving element on these surfaces, it is possible to increase the proportion of scattered light in the living body among the light received by the light receiving element.

The biological information measuring apparatus of the first invention preferably has a structure in which the respective light receiving elements are arranged at predetermined intervals on the same circumference with the light emitting element as the center. At this time, the interval between the light emitting element and each light receiving element becomes constant, and the influence of each light receiving element on the light emitting element 6 can be made the same condition.

The first invention includes a case where two or more of the light emitting elements are arranged and a light emission switching means for emitting light of a selected light emitting element among the light emitting elements is provided. The light emitting element can emit light alone or arbitrarily, and the light emitting element that outputs the largest pulse wave information can be selected.

A first aspect of the present invention is a translucent elastic member that covers the one surface so as to be sealed and uses the one surface as a pressing surface, and an air supply pipe that supplies pressurized air to the inside of the housing And further provided. The present invention includes a form in which the casing and the cuff are separated, and may be a form in which the casing is incorporated in the cuff by providing an elastic member and an air supply pipe. Any of these forms can be used in combination with the measurement location of the living body.

  According to the biological information measuring apparatus of the present invention, a plurality of light receiving elements are provided, and by using each light receiving signal measured by each light receiving element, a body light noise is reduced or a light receiving signal with less noise is selected and accuracy is selected. High pulse wave information can be obtained.

Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiment described below is an example of the configuration of the present invention, and the present invention is not limited to the following embodiment.
(First embodiment)

  First, a basic configuration of the biological information measuring apparatus according to the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a schematic cross-sectional view of the biological information measuring apparatus according to the first embodiment. FIG. 2 is a schematic plan view when viewing the direction of one surface from the outside of the housing of the biological information measuring apparatus according to the first embodiment. Note that a cross-sectional view taken along a line AA in FIG. 2 corresponds to FIG. In FIG. 2, the pedestal of the light emitting element and the light receiving element is omitted. The biological information measuring apparatus 100 according to the first embodiment includes a housing 2 having a translucent surface 3 and an inside of the housing 2, and emits emitted light 25 to the outside of the housing 2 through the surface 3. And at least one light emitting element 6 that is arranged inside the housing 2 and eight light receiving elements 5a to 5h that receive the scattered light 4 that is emitted from the outside of the housing 2 by the emitted light 25 through the one surface 3. First measurement value processing means (not shown) for selecting a light reception signal with the least body motion noise among the light reception signals measured by the light receiving elements 5a to 5h.

  In FIGS. 1 and 2 and the drawings described below, portions that can be realized by ordinary techniques such as a drive circuit of the light emitting element 6 and an amplifier that amplifies the signals of the light receiving elements 5a to 5h are not shown.

  The housing 2 serves as a container for the light emitting element 6 and the light receiving elements 5a to 5h, and at the same time shields the incidence of external light. The one surface 3 of the housing 2 is formed so as to have translucency, and light is allowed to enter and exit only from the one surface 3. For example, by opening one surface 3 and covering the opening with translucent glass or plastic sheet, the one surface 3 is formed to have translucency.

  The light emitting element 6 may be any light emitting element such as a light emitting diode (LED), an EL element, or a light bulb. In the present embodiment, it is preferable to use an LED in view of characteristics such as light quantity and power consumption. . The diameter of the package of the light emitting element 6 is preferably 0.5 to 2 mm, more preferably 0.8 to 1.2 mm, and most preferably about 1 mm. This is because, in a light emitting element such as an LED, when the amount of emitted light is the most commonly used, from several tens of microwatts to several hundreds of microwatts, the light emission efficiency is best when the size is several hundred micron squares.

  The emitted light 25 emitted from the light emitting element 6 to the outside of the housing 2 through the one surface 3 irradiates the living body 1 and is scattered inside the living body 1. The scattered light 4 enters the inside of the housing 2 through the one surface 3 and is measured by the light receiving elements 5a to 5h.

  As the light receiving elements 5a to 5h, any light receiving element such as a phototransistor, a photodiode, or a photoconductive element can be used. In the present embodiment, it is preferable to use a phototransistor. The diameter of the package of the light receiving elements 5a to 5h is preferably 0.5 to 2 mm, more preferably 0.8 to 1.2 mm, and most preferably about 1 mm. This is because, in the case of the light receiving element, when the incident light amount is from several tens of microwatts to several hundreds of microwatts, which is most often used, the light receiving efficiency becomes the best at a size of several hundred micron squares.

  The biological information measuring apparatus 100 according to the first embodiment shown in FIG. 1 and FIG. 2 has a configuration in which one light emitting element and eight light receiving elements are arranged, and the light receiving elements 5 a to 5 h are arranged surrounding the light emitting element 6. Although shown, the present invention is not limited to this arrangement. For example, in FIG. 2, two or more light emitting elements may be arranged, and a plurality of light receiving elements may be arranged around the light emitting elements. By providing a plurality of light receiving elements, the scattered light 4 can be detected not only by one light receiving element but also by other light receiving elements. Alternatively, FIG. 2 shows an example in which the light receiving elements 5a to 5h are arranged on the sides and corners of the square at regular intervals with the light emitting element 6 as the center, but the light receiving elements 5a to 5h are centered on the light emitting element 6. You may arrange | position with a predetermined space | interval on a concentric periphery, Preferably it is arrange | positioned at equal intervals. At this time, the distance between the light emitting element 6 and each of the light receiving elements 5a to 5h becomes constant, and the influence of the light receiving elements 5a to 5h on the light emitting element 6 can be made the same condition. Alternatively, as shown in FIG. 3, a pair 7 may be formed by the light emitting element 6 and the light receiving element 5, and a plurality of pairs 7 may be arranged so that adjacent elements are in contact with each other alternately for light emission and light reception. FIG. 3 is a schematic diagram illustrating another arrangement example of the light emitting element and the light receiving element. Since the light receiving elements adjacent to the light emitting elements are all at equivalent positions, the same effect as that of the apparent light receiving area can be obtained. In FIG. 3, the configuration other than the light emitting element and the light receiving element is not shown.

  In the present invention, the number of light emitting elements is one or more and the number of light receiving elements is two or more, and the number of light emitting elements and light receiving elements may be appropriately increased or decreased within a range satisfying this relationship. For example, (1) in the case where there is one light emitting element and a plurality of light receiving elements as shown in FIG. 2, (2) a plurality of light emitting elements, a plurality of light receiving elements as shown in FIG. When there are the same number of light emitting elements and light receiving elements, (3) when there are a plurality of light emitting elements, a plurality of light receiving elements, and there are more light emitting elements than the light receiving elements, (4) a plurality of light emitting elements, Any of a plurality of light-emitting elements and a case where there are fewer light-emitting elements than light-receiving elements may be used.

  The center-to-center distance between the light emitting element and the light receiving element is preferably 1 to 5 mm, and more preferably 1.55 to 1.95 mm. The optimum is about 1.75 mm.

  Here, as shown in FIG. 4, it is preferable to provide a separation wall 8 between the light emitting element 6 and the light receiving element 5 inside the housing 2. FIG. 4 is a schematic plan view showing an embodiment in which a separation wall is provided in the biological information measuring apparatus 100 shown in FIG. The separation wall is preferably formed of a light-shielding material, and the scattering on the separation wall may be further reduced by raising the wall surface. By providing the separation wall, stray light can be reduced, and the proportion of scattered light in the living body out of the light received by the light receiving element can be increased.

  The embodiment of FIG. 2 or FIG. 3 includes a case where the light emitting elements are connected in parallel. The circuit diagram of the 1st connection form of the light emitting element in the biological information measuring device which concerns on FIG. 5 at this embodiment was shown. In FIG. 5, 9 is a circuit power source and 10 is a constant current source. In this case, each light emitting element emits light simultaneously. However, in this embodiment, the light emission intensity of each light emitting element includes not only the case where light is emitted with the same intensity but also the case where light is emitted with mutually different intensity. Alternatively, two or more light emitting elements may be arranged, and a light emission switching unit that causes the light emitting element to emit light alone or emits light from only the light emitting element selected among the light emitting elements may be provided. The circuit diagram of the 2nd connection form of the light emitting element in the biological information measuring device which concerns on FIG. 6 at this embodiment was shown. In the circuit of FIG. 6, four light emitting elements 6 are arranged, and a switch 11 is provided so that the light emitting element is made to emit light alone by the light emission switching means 12 configured by switches corresponding to the respective light emitting elements. Only the selected light emitting element can be made to emit light. By switching the lighting of the light emitting element, it becomes possible to select the light emitting element at the position where the pulse wave becomes maximum. Further, since the current consumption of the light emitting element is generally several orders of magnitude higher than the current consumption of the light receiving element, it is possible to contribute to power saving by selecting an optimum light emitting element.

  The embodiment of FIG. 2 or 3 includes a case where the light receiving elements are connected in parallel. FIG. 7 shows a circuit diagram of a first connection form of the light receiving elements in the biological information measuring apparatus according to the present embodiment. In FIG. 7, the light receiving elements 5 are connected in parallel. Here, current-voltage conversion is performed by the resistor 13, and a pulse wave is extracted as a voltage signal. In this case, each light receiving element detects the scattered light 4 simultaneously. In the present embodiment, the output values of the respective light receiving elements are individually wired and input to the first measurement value processing means, and the output values of the respective light receiving elements are wired in parallel so as to be integrated into the first. Any case of inputting to the measured value processing means is included.

  In the biological information measuring apparatus 100, the light emitting element 6 and the light receiving elements 5a to 5h are arranged on the same plane, but the light emitting element and the light receiving element are the same paraboloid as shown in FIGS. You may arrange | position on a surface, the same spherical surface, or the same hyperboloid. FIG. 8 is a schematic cross-sectional view showing an arrangement example of a light emitting element and a light receiving element, where (a) is arranged on the same paraboloid, (b) is arranged on the same spherical surface, (c) is The case where it arrange | positions on the same hyperboloid is shown. By arranging the light emitting element and the light receiving element on the same paraboloid, the same spherical surface, or the same hyperboloid, as shown in FIG. 8, the normal line of the light emitting surface of the light emitting element and the normal line of the light receiving surface of the light receiving element are obtained. And the detection efficiency of scattered light can be increased. Thereby, the ratio of the scattered light in the living body among the light received by the light receiving element can be increased. Note that a lens may be disposed on the light emitting surface of the light emitting element or the light receiving surface of the light receiving element to focus the emitted light or scattered light.

  The first measurement value processing means (not shown) performs a process of selecting a light reception signal with the least body movement noise among the light reception signals measured by the light reception elements 5a to 5h. A light reception signal including pulse wave information with a maximum pulse wave may be selected, or a light reception signal including pulse wave information with the lowest background may be selected. Alternatively, each received light signal may be compared to select a received light signal including average pulse wave information. Furthermore, the light reception signal from the same light receiving element may always be selected with respect to the elapsed time during measurement, but it is preferable to select the light reception signal with the least body movement noise each time as time elapses. .

  FIG. 9 is a schematic diagram illustrating an example of a specific fixing method of the biological information measuring apparatus 100. The biological information measuring apparatus 100 shown in FIG. 9 is fixed to one end side of the U-shaped arm 17. A cuff 16 is fixed to the other end side of the U-shaped arm 17 so as to face the one surface 3 of the biological information measuring device 100. The tragus 15 is sandwiched between the cuff 16 and the one surface 3. At this time, the tragus 15 can be tightened by the expansion of the cuff while the biological information measuring device 100 and the cuff 16 are separated. That is, when air is supplied to the inside of the cuff 16 and the cuff 16 expands, the tragus 15 is pressed against the one surface 3. Thereby, the pulse wave of the tragus 15 can be measured.

In the biological information measuring apparatus according to this embodiment, as another form, the biological information measuring apparatus and the cuff may be integrated. FIG. 10 is a schematic diagram illustrating an example of a specific fixing method of the biological information measuring apparatus 200. The biological information measuring apparatus 200 shown in FIG. 10 is fixed to one end side of the U-shaped arm 17. The biological information measuring apparatus 200 covers one surface so as to be sealed, and uses the one surface as a pressing surface 19, and a translucent elastic member 20 having air permeability, and air supplying pressurized air to the inside of the housing 2. A supply pipe 18 is provided. The translucent member 20 having translucency is preferably formed of a plastic resin sheet having low rigidity. The air supply pipe 18 is connected to an air compressor (not shown). By incorporating the expandable member 20 and the air supply pipe into the housing 2, the biological information measuring device 200 can also function as a cuff. The tragus 15 is sandwiched between the biological information measuring device 200 and the other end of the U-shaped arm 17. At this time, the biological information measuring device 200 is integrated with the cuff, and the tragus 15 can be tightened by the expansion of the elastic member 20. That is, when air is supplied from the air supply pipe 18 to the inside of the housing 2 and the elastic member 20 expands, the tragus 15 is pressed by the pressing surface 19. Thereby, the pulse wave of the tragus 15 can be measured.
(Second Embodiment)

  Next, a biological information measuring apparatus according to the second embodiment will be described. Since the biological information measuring device according to the second embodiment is different from the biological information measuring device according to the first embodiment only in the measured value processing means, only the measured value processing means will be described, and the other description will be omitted. To do. The second measured value processing means of the biological information measuring apparatus according to the second embodiment performs a combined process on the respective received light signals measured by the respective light receiving elements to obtain a received light signal with reduced body movement noise.

  For example, there are three processing methods in the combination processing performed by the second measurement value processing means. In the first combination treatment, each received light signal is averaged or two or more received light signals are selected from each received light signal and then averaged. For example, all (eight) light reception signals of the light receiving elements 5a to 5h in FIG. 2 are input to the second measurement value processing unit, and the second measurement value processing unit averages all (eight) light reception signals. Alternatively, for example, in FIG. 2, the second measurement value processing unit selects an arbitrary received light signal from the light receiving elements 5 a to 5 h and further averages the selected received light signals. Here, when selecting an arbitrary light reception signal, it is preferable to select the remaining light reception signals by eliminating signals with high background or noise. By averaging each received light signal, noise can be reduced.

  In the second combination treatment, each received light signal is weighted average, or two or more received light signals are selected from each received light signal and then weighted average is performed. For example, all (eight) light reception signals of the light receiving elements 5a to 5h in FIG. 2 are input to the second measurement value processing means, and the second measurement value processing means outputs noise (of eight) of the light reception signals. Emphasize less received light signals, while neglecting noisy received signals and weighted average. Alternatively, for example, an arbitrary received light signal is selected from the light receiving elements 5a to 5h in FIG. 2 and input to the second measured value processing unit, and the second measured value processing unit includes the selected received light signal, The light receiving signal with less noise may be emphasized, while the light receiving signal with much noise may be ignored and the weighted average may be performed. Here, when selecting an arbitrary received light signal, it is preferable to exclude signals with high background or noise. Noise can be further reduced by weighted averaging of each received light signal.

  In the third combination treatment, each received light signal is subtracted. For example, among the light receiving elements 5a to 5h in FIG. 2, the first light receiving signal including biological information and noise and the second light receiving signal mainly including noise are selected, and the second light receiving signal is selected from the first light receiving signal. The noise can be reduced by obtaining the difference between the two. When the noise is due to a single factor, the noise can be reduced by obtaining the difference. Further, when the noise is caused by a plurality of factors, the noise may be reduced by classifying each type of noise and obtaining a difference.

  In addition, after calculating | requiring the average of each light reception signal containing biological information and noise, and calculating | requiring the average of each light reception signal mainly containing noise, these differences may be calculated | required and noise may be reduced.

Similarly to the case of the first embodiment, in the second embodiment, the received light signal from the same light receiving element may always be used for the elapsed time during measurement. It is desirable to use a light receiving signal with the least noise.
(Third embodiment)

  Next, a biological information measuring apparatus according to the third embodiment will be described. Since the biological information measuring apparatus according to the third embodiment is different from the biological information measuring apparatus according to the first embodiment only in the measured value processing means, only the measured value processing means will be described, and other description will be omitted. To do. The third measurement value processing means of the biological information measuring apparatus according to the third embodiment includes a light reception signal that maximizes an evaluation function value composed of an alternating current component and a direct current component of the waveform among the respective light reception signals measured by the respective light receiving elements. Select.

  There are, for example, three evaluation functions as the evaluation function used when the third measurement value processing means selects the received light signal. The first evaluation function is an AC component of the waveform of the received light signal. FIG. 11 is a graph showing the relationship between the received light signal intensity and the elapsed time. A waveform 30 is a pulse wave waveform obtained from the received light signal as pulse wave information. Here, the pulse wave waveform 30 includes an AC component 28 and a DC component 29 as shown in FIG. The AC component 28 of the pulse wave waveform 30 includes biological information such as pulse wave information, while the DC component 29 of the pulse wave waveform 30 includes noise and stray light information. Even if two or more light receiving elements are provided so that the shape of the cuff changes greatly and the direction of reflected light and the amount of reflected light change variously, any one of the light receiving elements does not change this. Some measure a small number of received light signals. Therefore, it is possible to obtain highly accurate pulse wave information by selecting a received light signal that maximizes the AC component of the waveform from among the received light signals measured by the respective light receiving elements.

  The second evaluation function uses the evaluation function as (AC component / DC component). High-accuracy pulse wave information can be obtained from a light reception signal in which an AC component including biological information is larger than a DC component including noise and stray light information. Even if two or more light receiving elements are provided so that the shape of the cuff changes greatly and the direction of reflected light and the amount of reflected light change variously, any one of the light receiving elements does not change this. Some measure a small number of received light signals. Therefore, it is possible to obtain highly accurate pulse wave information by selecting the light receiving signal having the maximum (AC component / DC component) from the light receiving signals measured by the light receiving elements.

  The third evaluation function uses the evaluation function as (the component of the specific frequency range / DC component of the AC component). FIG. 12 shows a conceptual diagram of the relationship between the received light signal intensity and the frequency of the AC component. The AC component contains a lot of biological information such as pulse wave information, but also includes noise. Among these, the AC component 33 derived from biological information is included in, for example, 0.1 to 10 Hz. On the other hand, the AC component 34 of noise is mostly on the low frequency side of 0.1 Hz or less, and is also included on the high frequency side exceeding 10 Hz. Therefore, since there are many biological information-related alternating current components relative to noise alternating current components in the alternating frequency component of the specific frequency range 32, for example, in the frequency range of 0.5 to 10 Hz, the evaluation function (the specific frequency range component of the alternating current component) / DC component). It is good also as a frequency range of 0.3-6 Hz and also a frequency range of 0.5-4 Hz. By providing two or more light receiving elements, even if the shape of the cuff changes greatly and the direction of reflected light and the amount of reflected light change variously, any of the light receiving elements has little change. Some measure light reception signals. Accordingly, it is possible to obtain pulse wave information with high accuracy by selecting a light reception signal having a maximum (a component in a specific frequency range / DC component among AC components) from among the respective light reception signals measured by each light receiving element.

  As in the case of the first embodiment, in the third embodiment, a light reception signal from the same light receiving element may always be selected with respect to the elapsed time during measurement. It is preferable to select a light receiving signal with the least noise.

  The biological information measuring apparatus according to the present invention can be used for blood pressure measurement, pulse wave measurement, and blood flow measurement for health and beauty. Moreover, it is suitable for detecting the pulsation of an arteriole and can be applied to a place where the transmission type cannot be used.

It is a schematic sectional drawing of the biological information measuring device which concerns on 1st Embodiment. It is a schematic plan view when the direction of one surface is seen from the outside of the housing of the biological information measuring device according to the first embodiment. It is the schematic which shows the other example of arrangement | positioning of a light emitting element and a light receiving element. It is a schematic plan view which shows one form which provided the separation wall in the biological information measuring device. It is a circuit diagram of the 1st connection form of the light emitting element in the living body information measuring device concerning this embodiment. It is a circuit diagram of the 2nd connection form of the light emitting element in the living body information measuring device concerning this embodiment. It is a circuit diagram of the 1st connection form of the light receiving element in the living body information measuring device concerning this embodiment. It is a schematic sectional drawing which shows the example of arrangement | positioning of the light emitting element and light receiving element in the biological information measuring device which concerns on this embodiment, When (a) arrange | positions on the same paraboloid, (b) has arrange | positioned on the same spherical surface In the case, (c) shows a case where they are arranged on the same hyperboloid. It is the schematic which shows an example of the concrete fixing method of the biometric information measuring device 100. FIG. It is the schematic which shows an example of the concrete fixing method of the biological information measuring device 200. FIG. It is a graph which shows the relationship between received light signal intensity and elapsed time. It is a conceptual diagram of the relationship between a received signal strength and the frequency of an alternating current component.

Explanation of symbols

1, living body 2, housing 3, one surface 4, scattered light 5, 5a-5h, light receiving element 6, light emitting element 7, pair 8, separation wall 9, circuit power supply 10, constant current source 11, switch 12, light emission switching Means 13, resistor 15, tragus 16, cuff 17, U-shaped arm 18, air supply pipe 19, pressing surface 20, telescopic member 25, outgoing light 28, AC component 29, DC component 30, pulse waveform 32, specific Frequency range 33, AC component 34 derived from biological information, AC component 100, 200 of noise Biometric information measuring device

Claims (9)

A housing whose one surface is translucent,
At least one light emitting element disposed inside the housing and emitting emitted light to the outside of the housing through the one surface;
Two or more light receiving elements that are disposed inside the housing and receive scattered light scattered by the emitted light outside the housing through the one surface;
A third measured value processing means for selecting a received light signal having a maximum evaluation function value composed of an alternating current component and a direct current component of the waveform among the received light signals measured by the light receiving elements;
A biological information measuring device comprising: 2. The biological information according to claim 1, wherein the third measurement value processing means uses the evaluation function as the alternating current component, and selects the received light signal having the maximum value of the alternating current component among the received light signals. Measuring device. The third measured value processing means selects the received light signal having the maximum value (the alternating current component / the direct current component) among the received light signals, with the evaluation function being (the alternating current component / the direct current component). The living body information measuring device according to claim 1 characterized by things. The third measurement value processing means has an evaluation function (a component of a specific frequency range among the AC components / DC component), and among the received light signals, (a component of a specific frequency range among the AC components / the component described above). 2. The biological information measuring device according to claim 1 , wherein a light reception signal having a maximum value of a direct current component) is selected. 5. The biological information measuring apparatus according to claim 1 , wherein a separation wall between the light emitting element and the light receiving element is provided inside the casing. 6. The biological information measuring apparatus according to claim 1, wherein the light emitting element and the light receiving element are arranged on the same paraboloid, the same spherical surface, or the same hyperboloid. 7. The biological information measuring device according to claim 1, wherein each of the light receiving elements has a structure arranged at a predetermined interval on the same circumference with the light emitting element as a center. Wherein placing the light emitting element 2 or more, according to claim 1,2,3,4,5,6 or 7 wherein the provision of the emission switching means for the light emitting element selected among the light emitting element Biological information measuring device. Covering the one surface so as to be sealed, and using the one surface as a pressing surface, a translucent member having translucency,
An air supply pipe for supplying pressurized air to the inside of the housing;
9. The biological information measuring device according to claim 1, 2, 3, 4, 5, 6, 7 or 8 .

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