JP2019076538A - Signal processing circuit and living body analyzing device - Google Patents

Abstract

A configuration for amplifying a high frequency component of voltages corresponding to a current generated by a light receiving element and generating a voltage maintaining a low frequency component is simplified.
A current / voltage conversion unit converts a current generated by a light receiving element into a first voltage, a high frequency component of the first voltage is amplified, and a low frequency component of the first voltage is maintained. A signal processing circuit comprising: a high band amplification unit that generates two voltages without separating the high band component and the low band component.
[Selected figure] Figure 3

Description

  The present invention relates to techniques for processing signals.

  Conventionally, techniques for processing a voltage signal according to the level of light received by the light receiving element have been proposed. For example, Patent Document 1 discloses a technique for removing a direct current component in a light reception signal generated by a light receiving element and then amplifying an alternating current component. The alternating current component after amplification is used to calculate the concentration of the blood component.

JP 2004-290545 A

  In the technique of Patent Document 1, when using the DC component of the light reception signal to calculate the concentration of the blood component, an element for processing the DC component is required separately from the component for processing the AC component. That is, a configuration is required to separate an AC component and a DC component from the light reception signal and process each component individually, and there is a problem that the configuration is complicated. In consideration of the above circumstances, the preferred embodiment of the present invention has a simple configuration for amplifying a high frequency component of the voltage corresponding to the current generated by the light receiving element to generate a voltage maintaining a low frequency component. Aims to

  In order to solve the above problems, a signal processing circuit according to a preferred aspect of the present invention includes a current / voltage conversion unit that converts a current generated by a light receiving element into a first voltage; The high-frequency amplification unit amplifies the component and generates a second voltage maintaining the low-frequency component of the first voltage without separating the high-frequency component and the low-frequency component. In the above aspect, the high voltage component of the first voltage is amplified, and the second voltage maintaining the low frequency component of the first voltage is generated without separating the high frequency component and the low frequency component. A second high-frequency component of the first voltage is amplified to maintain the low-frequency component, as compared with a configuration in which the high-frequency component and the low-frequency component of the first voltage are separated and processed individually. The configuration for generating the voltage is simplified.

  In a preferred aspect of the present invention, the high-frequency amplification unit includes an operational amplifier that includes a first input end to which the first voltage is input and a second input end, and outputs the second voltage; Between a first resistance element provided on a feedback path for feeding back two voltages to the second input end, a second resistance element connected to the second input end, and the second resistance element and the ground line And a first capacitive element connected to the In the above aspect, the high frequency component of the first voltage is amplified by the simple configuration in which the first capacitance element is added to the non-inversion amplification circuit composed of the operational amplifier, the first resistance element, and the second resistance element. Thus, the second voltage maintaining the low frequency component can be generated.

  In a preferred aspect of the present invention, the high frequency band amplification unit includes a second capacitive element connected in parallel to the first resistive element. In the above aspect, since the high-frequency amplification unit includes the second capacitive element connected in parallel with the first resistive element, high frequency noise in the second voltage can be reduced by the second capacitive element.

  A biological analysis apparatus according to a preferred aspect of the present invention includes a light receiving element for receiving light coming from a living body, the signal processing circuit according to each of the above aspects into which the current generated by the light receiving element is input, and the signal processing circuit And a biological analysis unit that calculates a biological index related to the living body according to the generated second voltage. Since each signal processing circuit described above simplifies the configuration for amplifying the high-frequency component of the first voltage and generating the second voltage maintaining the low-frequency component, the biological analyzer uses the second voltage as the second voltage. Accordingly, the configuration for calculating the biometrics related to the living body is also simplified.

  In a preferred aspect of the present invention, the biological index is an index related to blood flow or blood pressure of the living body. The above aspect has the advantage of being able to calculate an index related to blood flow or blood pressure, which is a basic and important index for diagnosing the condition of a living body.

  In a preferred aspect of the present invention, the biological analysis unit may calculate, among the second voltages, a value obtained by integrating the product of the intensity of each frequency in the intensity spectrum of the second voltage and the frequency within a predetermined frequency range. The blood flow index is calculated by normalizing the low frequency component. In the above aspect, a value obtained by integrating the product of the intensity of each frequency in the intensity spectrum of the second voltage and the frequency within a predetermined frequency range is normalized to the low frequency component of the second voltage and the index related to blood flow Is calculated, for example, as compared with a configuration in which a value obtained by integrating the product of the intensity of each frequency in the intensity spectrum of the second voltage and the frequency in a predetermined frequency range is used as an index for blood flow. An index relating to blood flow can be calculated with equal or better accuracy in the configuration.

It is a side view of a living body analysis device concerning a 1st embodiment of the present invention. It is the block diagram which paid its attention to the function of a living body analysis device. It is a block diagram of a signal processing circuit. It is the graph which showed the 1st voltage and the 2nd voltage. It is a virtual block diagram showing the function of the amplification process part with respect to the high frequency component of feedback voltage. It is a virtual block diagram showing the function of the amplification process part with respect to the low-pass component of feedback voltage. It is a graph which shows the amplification factor characteristic of a high region amplification part. It is a schematic diagram which shows the usage example of the biometric analyzer which concerns on 2nd Embodiment. It is a schematic diagram which shows the other usage example of the biometric analyzer which concerns on 2nd Embodiment. It is a block diagram of the biometric analyzer in a modification. It is a block diagram of the biometric analyzer in a modification. It is a block diagram of the biometric analyzer in a modification.

First Embodiment
FIG. 1 is a side view of a biological analysis device 100 according to a first embodiment of the present invention. The biological analysis device 100 is a measurement device that non-invasively measures an index (hereinafter, referred to as a “blood flow index”) related to the blood flow of a living body of a subject. The biological analysis device 100 is attached to a specific part (hereinafter referred to as “measurement part”) H of the subject's body. For example, the wrist and the upper arm are illustrated as the measurement site H.

  The biological analysis device 100 is attached to the measurement site H. The biological analysis device 100 according to the first embodiment is a wristwatch-type portable device including a housing 12 and a belt 14 as illustrated in FIG. 1. The biological analysis device 100 is mounted on the subject's body by winding the belt 14 around the measurement site H.

  FIG. 2 is an electrical block diagram of the biological analysis device 100. As shown in FIG. The biological analysis device 100 includes a detection device 30, a biological analysis unit 22, and a display device 23. The biological analysis unit 22 is installed inside the housing unit 12. The display device 23 (for example, a liquid crystal display panel) is installed, for example, on the surface of the housing 12 opposite to the measurement site H, as illustrated in FIG. The display device 23 displays various images including the measurement results.

  The detection device 30 is an optical sensor module that generates a detection signal S according to the state of the measurement site H. As illustrated in FIG. 2, the detection device 30 according to the first embodiment includes a light emitting element 31, a light receiving element 32, a drive circuit 33, and a signal processing circuit 34. The light emitting element 31 and the light receiving element 32 are installed, for example, at a position facing the measurement site H in the housing 12. Note that one or both of the drive circuit 33 and the signal processing circuit 34 can be installed as an external circuit separate from the detection device 30.

  The light emitting element 31 is a light source for irradiating the measurement site H with light. The light emitting element 31 of the first embodiment irradiates the measurement site H with coherent laser light in a narrow band. For example, a VCSEL (Vertical Cavity Surface Emitting LASER) or the like that emits laser light due to resonance in a resonator is suitably used as the light emitting element 31. The light emitting element 31 according to the first embodiment irradiates, for example, light of a predetermined wavelength λ (λ = 800 nm to 1300 nm) in the near infrared region to the measurement site H. The drive circuit 33 causes the light emitting element 31 to emit light. Note that a plurality of light emitting elements 31 that emit light of different wavelengths may be used. Further, the light emitted from the light emitting element 31 is not limited to near infrared light.

  The light incident on the measurement site H from the light emitting element 31 passes through the inside of the measurement site H, repeats diffuse reflection, and exits the living body. Specifically, light passing through a blood vessel such as an artery (for example, the brachial artery, radial artery or ulnar artery) present inside the measurement site H and the blood in the blood vessel are emitted from the measurement site H. The light receiving element 32 receives light coming from the measurement site H. Specifically, the light receiving element 32 generates a current according to the intensity of the received light. For example, a photodiode (PD: Photo Diode) that generates a charge according to the light reception intensity is used as the light receiving element 32. Specifically, the light receiving element 32 in which the photoelectric conversion layer is formed of InGaAs (indium gallium arsenide) which exhibits high sensitivity in the near infrared region is preferable. As understood from the above description, the detection device 30 of the first embodiment is a reflective optical sensor in which the light emitting element 31 and the light receiving element 32 are positioned on one side of the measurement site H. However, a transmission type optical sensor in which the light emitting element 31 and the light receiving element 32 are located on the opposite side of the measurement site H may be used as the detection device 30.

  FIG. 3 is a block diagram of the signal processing circuit 34. As shown in FIG. The signal processing circuit 34 generates a detection signal S according to the intensity of the light received by the light receiving element 32. Specifically, the signal processing circuit 34 includes a current / voltage conversion unit 341 and a high frequency amplification unit 343.

  The current / voltage converter 341 converts the current generated by the light receiving element 32 into the first voltage V1 by receiving the light. Specifically, the current / voltage conversion unit 341 is a transimpedance amplifier configured of, for example, the operational amplifier 51, the resistance element 53, and the capacitance element 55.

  The high band amplification unit 343 generates a second voltage V2 from the first voltage V1 generated by the current / voltage conversion unit 341. FIG. 4 is a graph showing the first voltage V1 (solid line) and the second voltage V2 (broken line). As understood from FIG. 4, the second voltage V2 is a voltage obtained by amplifying the high frequency component (AC component) of the first voltage V1 and maintaining the low frequency component (DC component) of the first voltage V1. . Specifically, the high band amplification unit 343 includes the amplification processing unit 60 and the second capacitive element 80 as illustrated in FIG. 3. The amplification processing unit 60 includes an operational amplifier 61, a first resistance element 63, a second resistance element 65, and a first capacitance element 67.

  The operational amplifier 61 includes a first input end (non-inverted input end) T1 and a second input end (inverted input end) T2. The first voltage V1 generated by the current / voltage converter 341 is input to the first input terminal T1. The second voltage V2 generated by the operational amplifier 61 is output from the output terminal Tout. The output end Tout and the second input end T2 of the operational amplifier 61 are connected via the first resistance element 63 (resistance value R1). That is, a feedback path (negative feedback path) for feeding back the second voltage V2 to the second input terminal T2 of the operational amplifier 61 is formed. Specifically, a voltage (hereinafter referred to as "feedback voltage") Vf corresponding to the second voltage V2 is input to the second input terminal T2 via a feedback path.

The second resistance element 65 (resistance value R2) is connected to the second input terminal T2 of the operational amplifier 61. A first capacitive element 67 (electrostatic capacitance C1) is connected between the second resistive element 65 and the ground line. Specifically, one terminal E1 of the first capacitive element 67 is connected to the second resistance element 65, and the other terminal E2 is connected to the ground line. The first capacitive element 67 of the first embodiment passes the high-frequency component of the current (specifically, the component above the frequency fL) according to the feedback voltage Vf, and the low-frequency component of the current (specifically, the frequency It functions as a high pass filter that blocks components below fL). The frequency fL is expressed by the following equation (1). The frequency fL can be set according to the resistance value R2 of the second resistance element 65 and the capacitance C1 of the first capacitance element 67.

FIG. 5 is a virtual block diagram showing the function of amplification processing unit 60 for high frequency components of feedback voltage Vf, and FIG. 6 is a virtual view showing the function of amplification processing unit 60 for low frequency components of feedback voltage Vf. FIG. As described above, since the high frequency component of the current corresponding to the feedback voltage Vf passes through the first capacitance element 67, the high frequency component is equivalent to the configuration in which the second resistance element 65 is grounded. That is, as illustrated in FIG. 5, the non-inverting amplification circuit (the operational amplifier in which the second resistance element 65 is connected to the second input terminal T2 with respect to the high frequency component of the feedback voltage Vf (the component exceeding the frequency fL) The amplification processing unit 60 functions as Therefore, the high frequency component of the first voltage V1 of FIG. 4 is amplified at a desired amplification factor A. The amplification factor A is expressed by the following equation (2). The amplification factor A can be set according to the resistance value R1 of the first resistance element 63 and the resistance value R2 of the second resistance element 65.

  On the other hand, the low frequency component of the current corresponding to the feedback voltage Vf is cut off by the first capacitance element 67, so the low frequency component is equivalent to a configuration in which the second resistance element 65 is isolated from the ground line. That is, as illustrated in FIG. 6, amplification processing is performed as a voltage follower type buffer circuit in which the amplification factor is set to 0 dB (1 ×) for the low frequency component (component below frequency fL) of feedback voltage Vf. The unit 60 functions. Therefore, the low frequency component of the first voltage V1 of FIG. 4 is maintained at the second voltage V2. As understood from the above description, the high frequency amplification unit 343 amplifies the high frequency component of the first voltage V1 and maintains the low voltage component of the first voltage V1 as a high frequency component. It functions as an element which produces | generates and low-pass components without separating.

As illustrated in FIG. 3, the second capacitive element 80 (electrostatic capacitance C2) is connected in parallel with the first resistive element 63 of the amplification processing unit 60. The second capacitive element 80 functions as a low pass filter that removes high frequency noise that may occur at the second voltage V2. Specifically, the component below the frequency fH (> fL) of the output voltage (second voltage V2) of the operational amplifier 61 is allowed to pass, and the component above the frequency fH is blocked. The frequency fH is expressed by the following equation (3). The frequency fH can be set according to the resistance value R1 of the first resistance element 63 and the capacitance C2 of the second capacitance element 80.

  FIG. 7 is a graph showing the amplification factor characteristic of the high-frequency amplification unit 343. As understood from FIG. 7, the low frequency component (component below the frequency fL) of the first voltage V1 is maintained, and the high frequency component (component above the frequency fL) of the first voltage V1 has an amplification factor A (1 + R1). / R2) is amplified. Further, among the high frequency components of the first voltage V1, a component exceeding the frequency fH (that is, a component that can be high frequency noise) is reduced. The second voltage V2 generated by the high-frequency amplification unit 343 is output to the biological analysis unit 22 as a detection signal S. Note that illustration of an A / D converter for converting the detection signal S output from the high-frequency amplification unit 343 from analog to digital is omitted for convenience.

  The light reaching the light receiving element 32 of FIG. 2 is a component diffused and reflected by the tissue (static tissue) at rest inside the measurement site H, and an object (typically, moving inside the artery inside the measurement site H (Red blood cells) and components reflected diffusely. The frequency of the light does not change before and after diffuse reflection at the static tissue. On the other hand, before and after diffuse reflection in red blood cells, the frequency of light changes by a change amount (hereinafter referred to as “frequency shift amount”) proportional to the moving speed of red blood cells (that is, blood flow speed). That is, the light passing through the measurement site H and reaching the light receiving element 32 contains a component that is shifted (frequency shifted) by the frequency shift amount with respect to the frequency of the light emitted by the light emitting element 31. The detection signal S supplied to the biological analysis unit 22 is a light beat signal in which the frequency shift due to the blood flow inside the measurement site H is reflected.

The biological analysis unit 22 calculates a blood flow index in accordance with the detection signal S (second voltage V2) generated by the signal processing circuit 34. For example, the biological analysis unit 22 is realized by execution of a program by an arithmetic processing unit such as a central processing unit (CPU) or a field-programmable gate array (FPGA). The biological analysis unit 22 of the first embodiment calculates a blood flow index F (so-called FLOW value) as a blood flow index. The blood flow index F is an index of the blood flow of the measurement site H (that is, the volume of blood moving in the artery within a unit time). Specifically, the biological analysis unit 22 calculates an intensity spectrum from the detection signal S, and calculates a blood flow index F from the intensity spectrum. The blood flow index F is calculated by the following equation (4a). The symbol <I ² > of the equation (4a) is an average value of the intensity G (0) (that is, the signal intensity of the low frequency component) at 0 Hz in the intensity spectrum. The living body analysis unit 22 separates the low frequency component from the detection signal S by arithmetic processing, and uses the average value of the signal intensities I of the low frequency component for the calculation of equation (4a). The blood flow index F may be calculated by setting the average intensity of the detection signal S over the entire band as <I ² >.

As understood from the equation (4a), the first moment (f × G (f)) which is the product of the signal strength G (f) of each frequency f in the intensity spectrum and the frequency f is the lower limit on the frequency axis The blood flow index F is calculated by integrating the range between the value f1 and the upper limit f2. As understood from the above description, the biological analysis unit 22 determines the product of the intensity G (f) of each frequency f in the intensity spectrum of the second voltage V2 and the frequency f within a predetermined frequency range (f1 to f2). The blood flow index F is calculated by normalizing the value integrated in step S2 with the low frequency component of the second voltage V2. The biological analysis unit 22 may calculate the blood flow index F by the following equation (4b) in which the integral of the equation (4a) is replaced with the sum (総 和). The calculation of the blood flow index F by the biological analysis unit 22 is repeatedly performed for each unit period. The display device 23 displays the blood flow index F calculated by the biological analysis unit 22.

  As understood from the above description, in the first embodiment, the second voltage V2 that amplifies the high frequency component of the first voltage V1 and maintains the low frequency component of the first voltage V1 is the high frequency component. Compared to the configuration in which the high frequency component and the low frequency component of the first voltage V1 are separated and each is individually processed because the low voltage component is generated without being separated from the low voltage component, The configuration for amplifying the high frequency component and generating the second voltage V2 maintaining the low frequency component is simplified. As a result, the configuration for calculating the blood flow index F in accordance with the second voltage V2 is also simplified. Since the high frequency component is very weak with respect to the low frequency component at the first voltage V1, the blood flow index F can not be calculated with high accuracy unless the high frequency component is amplified. In the first embodiment, since the high frequency component is amplified at the second voltage V2 (a high frequency component having a high SN ratio is obtained), the blood flow index F can be calculated with high accuracy.

  In the first embodiment, in particular, a value obtained by integrating the product of the intensity of each frequency in the intensity spectrum of the second voltage V2 and the frequency within a predetermined frequency range is normalized by the low frequency component of the second voltage V2. Since the blood flow index F is calculated, for example, a value obtained by integrating the product of the intensity of each frequency in the intensity spectrum of the second voltage V2 and the frequency in a predetermined frequency range is calculated as the blood flow index F Compared to the configuration in which the numerical values are not normalized, the influence of the variation of the light quantity of the light emitting element 31 and the variation of the quantity of ambient light (for example, illumination light and sunlight) is reduced. Therefore, the blood flow index F can be calculated with an accuracy equal to or higher than that of a configuration not normalized with a simple configuration.

Second Embodiment
FIG. 8 is a schematic view showing an example of use of the biological analysis device 100 in the second embodiment. As illustrated in FIG. 8, the biological analysis device 100 includes a detection unit 71 and a display unit 72 which are configured separately from each other. The detection unit 71 includes the detection device 30 illustrated in each of the embodiments described above. FIG. 8 exemplifies a detection unit 71 mounted on the upper arm of the subject. As illustrated in FIG. 9, a detection unit 71 configured to be worn on the subject's wrist is also suitable.

  The display unit 72 includes the display device 23 exemplified in each of the above-described embodiments. For example, an information terminal such as a mobile phone or a smartphone is a preferred example of the display unit 72. However, the specific form of the display unit 72 is arbitrary. For example, a wristwatch-type information terminal portable by a subject or a dedicated information terminal of the biological analysis device 100 may be used as the display unit 72.

  The biological analysis unit 22 is mounted on, for example, the display unit 72. The detection signal S generated by the detection device 30 of the detection unit 71 is transmitted to the display unit 72 in a wired or wireless manner. The biological analysis unit 22 of the display unit 72 calculates the blood flow index F from the detection signal S and displays it on the display device 23.

  The biological analysis unit 22 may be mounted on the detection unit 71. The biological analysis unit 22 calculates a blood flow index F from the detection signal S generated by the detection device 30, and transmits data for displaying the blood flow index F to the display unit 72 by wire or wirelessly. The display device 23 of the display unit 72 displays the blood flow index F indicated by the data received from the detection unit 71.

<Modification>
Each form illustrated above can be variously deformed. The aspect of a specific deformation | transformation is illustrated below. It is also possible to appropriately merge two or more aspects arbitrarily selected from the following exemplifications.

(1) In each of the embodiments described above, the high frequency amplification unit 343 is configured by the amplification processing unit 60 and the second capacitive element 80, but the configuration of the high frequency amplification unit 343 is not limited to the above example. For example, the high frequency amplification unit 343 may be configured with only the amplification processing unit 60. That is, the second capacitive element 80 is not essential in the high frequency amplification unit 343. However, according to the configuration in which the high-frequency amplification unit 343 includes the second capacitive element 80, high frequency noise in the second voltage V2 can be reduced by the second capacitive element 80. Further, instead of the second capacitive element 80, a low pass filter capable of reducing high frequency noise of the second voltage V2 may be provided downstream of the output terminal Tout.

(2) In each of the above-described embodiments, the amplification processing unit 60 is configured by the operational amplifier 61, the first resistance element 63, the second resistance element 65, and the first capacitance element 67. It is not limited to the illustration of. However, according to each embodiment described above in which the amplification processing unit 60 is configured by the operational amplifier 61, the first resistive element 63, the second resistive element 65, and the first capacitive element 67, the operational amplifier 61 and the first resistive element 63 A second configuration in which the high frequency component of the first voltage V1 is amplified and the low frequency component is maintained by a simple configuration in which the first capacitive element 67 is added to the non-inversion amplification circuit configured by A voltage V2 can be generated.

(3) In the above-described embodiments, the biological analysis unit 22 calculates the blood flow index F as a blood flow index, but the blood flow index calculated by the biological analysis unit 22 is not limited to the above examples. For example, it is also possible to calculate the blood flow according to the blood flow index F or the blood flow velocity obtained by dividing the blood flow by the cross-sectional area of the blood vessel as the blood flow index. Further, the index calculated by the biological analysis unit 22 is not limited to the blood flow index. For example, blood volume index (so-called MASS value), blood vessel diameter or cross section of blood vessel according to blood volume index, oxygen saturation (SpO2), or index related to blood pressure of living body (eg blood pressure, average blood pressure or pulse pressure) The analysis unit 22 may calculate. Each index illustrated above is comprehensively expressed as an index about a living body (hereinafter, referred to as “biometric index”). The biological analysis unit 22 functions as an element that calculates a biological index according to the second voltage V2. Note that the condition (for example, blood pressure condition) of the subject is specified from a plurality of stages (for example, abnormal / high eye / normal, etc.) from the biological index (for example, blood pressure) calculated by the biological analysis unit 22 and notified to the subject Is also possible.

(4) In each of the above-described embodiments, the biological analysis device 100 configured as a single device is illustrated. However, as illustrated below, a plurality of elements of the biological analysis device 100 can be realized as separate devices. .

  Although the biological analysis device 100 including the detection device 30 is illustrated in the above-described embodiments, a configuration in which the detection device 30 is separated from the biological analysis device 100 is also assumed as illustrated in FIG. 10. The detection device 30 is, for example, a portable optical sensor module mounted on a measurement site H such as the subject's wrist or upper arm. The biological analysis device 100 is realized by an information terminal such as a mobile phone or a smartphone. The biological analysis device 100 may be realized by a watch-type information terminal. The detection signal S generated by the detection device 30 is transmitted to the biological analysis device 100 in a wired or wireless manner. The biological analysis unit 22 of the biological analysis device 100 calculates a biological index from the detection signal S and displays it on the display device 23. As understood from the above description, the detection device 30 can be omitted from the biological analysis device 100.

  In each of the above-described embodiments, the biological analysis device 100 including the display device 23 is exemplified. However, as exemplified in FIG. 11, a configuration in which the display device 23 is separated from the biological analysis device 100 is also assumed. The biological analysis unit 22 of the biological analysis device 100 calculates a biological index from the detection signal S, and transmits data for displaying the index to the display device 23. The display device 23 may be a dedicated display device, but may be mounted on, for example, an information terminal such as a mobile phone or a smartphone, or a wristwatch-type information terminal portable by a subject. The biological index calculated by the biological analysis unit 22 of the biological analysis device 100 is transmitted to the display device 23 by wire or wirelessly. The display device 23 displays the biological index received from the biological analysis device 100. As understood from the above description, the display device 23 can be omitted from the biological analysis device 100.

  As exemplified in FIG. 12, a configuration in which the detection device 30 and the display device 23 are separated from the biological analysis device 100 (biological analysis unit) is also assumed. For example, the biological analysis device 100 (biological analysis unit) is mounted on an information terminal such as a mobile phone or a smartphone.

  In the configuration in which the detection device 30 and the biological analysis device 100 are separated, it is also possible to mount an element for calculating the intensity spectrum in the detection device 30. The intensity spectrum calculated by the detection device 30 is transmitted to the biological analysis device 100 by wire or wireless.

(5) In each of the above-described embodiments, the wristwatch-type biological analysis device 100 including the housing unit 12 and the belt 14 is illustrated. However, the specific configuration of the biological analysis device 100 is arbitrary. For example, a patch type that can be applied to the subject's body, an ear worn type that can be worn on the subject's ear, a finger worn type that can be worn on the subject's fingertip (for example, nailed), or can be worn on the subject's head Any form of biological analysis apparatus 100 such as a head-mounted type can be employed.

(6) In each of the above-described embodiments, the indicator of the subject is displayed on the display device 23. However, the configuration for notifying the subject of the indicator is not limited to the above example. For example, it is also possible to notify the subject of the biological index by voice. In the ear worn type biological analysis apparatus 100 that can be attached to the subject's ear, a configuration in which the biological index is notified by voice is particularly preferable. In addition, it is not essential to notify the subject of the biological index. For example, the biometric index calculated by the biological analysis device 100 may be transmitted from the communication network to another communication device. In addition, the biological index may be stored in a storage device (not shown) of the biological analysis device 100 or a portable recording medium that is removable from the biological analysis device 100.

(7) The biological analysis device 100 according to each of the above-described embodiments is realized by the cooperation of an arithmetic processing device such as a CPU and a program, as described above. The program according to the preferred embodiment of the present invention may be provided in the form of being stored in a computer readable recording medium and installed on the computer. Moreover, it is also possible to provide a computer stored in a recording medium of the distribution server in the form of distribution via a communication network. The recording medium is, for example, a non-transitory recording medium, and is preferably an optical recording medium (optical disc) such as a CD-ROM, but any known medium such as a semiconductor recording medium or a magnetic recording medium may be used. Recording media of the form Note that non-transitory recording media include any recording media except transient propagation signals, and do not exclude volatile recording media.

DESCRIPTION OF SYMBOLS 100 ... Biometric-analysis apparatus 12, 12 ... Housing | casing part, 14 ... Belt, 22 ... Biometric-analysis part, 23 ... Display apparatus, 30 ... Detection apparatus, 31 ... Light emitting element, 32 ... Light receiving element, 33 ... Drive circuit, 34 ... Signal Processing circuit 341: voltage conversion unit 343: high frequency amplification unit 51: operational amplifier 53: resistance element 55: capacitance element 60: amplification processing unit 61: operational amplifier 63: first resistance element 65 ... second resistance element, 67 ... first capacitance element, 80 ... second capacitance element.

Claims (6)

A current / voltage converter for converting the current generated by the light receiving element into a first voltage;
A high band amplification that amplifies a high band component of the first voltage and generates a second voltage maintaining the low band component of the first voltage without separating the high band component and the low band component A signal processing circuit comprising a part. The high frequency amplification unit
An operational amplifier that includes a first input end to which the first voltage is input and a second input end, and outputs the second voltage.
A first resistance element disposed on a feedback path for feeding back the second voltage to the second input terminal;
A second resistive element connected to the second input terminal;
The signal processing circuit according to claim 1, further comprising: a first capacitive element connected between the second resistive element and a ground line. The signal processing circuit according to claim 2, wherein the high frequency band amplification unit includes a second capacitive element connected in parallel to the first resistive element. A light receiving element for receiving light coming from a living body;
The signal processing circuit according to any one of claims 1 to 3, wherein the current generated by the light receiving element is input.
And a biological analysis unit configured to calculate a biological index related to the living body according to the second voltage generated by the signal processing circuit. The biological analysis device according to claim 4, wherein the biological index is an index related to blood flow or blood pressure of the living body. The biological analysis unit normalizes a value obtained by integrating a product of an intensity of each frequency in the intensity spectrum of the second voltage and the frequency within a predetermined frequency range with a low frequency component of the second voltage. The biological analysis device according to claim 5, wherein an index related to blood flow is calculated.

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