JP2015081916A - Blood glucose measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blood glucose measuring apparatus capable of measuring a blood glucose level without requiring fine optical axis adjustment between a light-emitting element and a light receiving element and without being restricted to the position of a blood vessel of the user.SOLUTION: The blood glucose measuring apparatus comprises: a lens substrate on which a plurality of lenses 1 each having a salient on one surface of a transparent plastic plate and having a flat shape on the other surface are integrally molded; a plurality of light-emitting elements 2 sequentially emitting a light beam of a specific wavelength having high absorption rate according to a blood glucose level, and transmitting the beam through the corresponding lens; a plurality of light receiving elements 3 formed corresponding to each of the plurality of lenses 1, receiving a beam of a wavelength transmitting through the lens and converging in a region defined by an inner edge and an outer edge outside the inner edge of the light-emitting element 2, and generating an electric signal indicating an intensity value of the beam; and an arithmetic circuit 301 calculating data of a blood glucose level of an object close to one surface of the lens substrate.

Description

  The present invention relates to a sugar content measuring apparatus for measuring the sugar content of blood.

  Diabetes, a lifestyle-related disease, tends to increase year by year. According to a 2002 survey by the Ministry of Health, Labor and Welfare, there are approximately 7.4 million diabetic patients in Japan, and about half of them are being treated. It is said. If the blood sugar level is high, the medicine is used to lower the blood sugar level. On the other hand, since it is extremely dangerous if hypoglycemia is caused by the influence of drugs, it is performed to raise blood sugar level by eating salmon and the like. For this reason, in the treatment of diabetes, blood is collected from a patient with an injection needle and the blood glucose level is measured. As a matter of course, there is a risk of infection after blood collection in addition to pain for the patient during blood collection.

Therefore, research has been conducted by a non-invasive means for measuring a blood glucose level using a near-infrared light beam without collecting blood from a patient with an injection needle.
For example, in a biological reaction measurement method and a biological reaction measurement system according to a proposal, when a user senses that a finger for detection has been inserted, near infrared light from a light source is irradiated to the measurement site of the finger, and measurement is performed. A near-infrared ray having a specific wavelength reflected from a part is detected by an absorption intensity detector, and the absorption spectrum is converted into an electric signal. (See Patent Document 1)
In addition, in a spectroscopic data capturing device for measuring glucose concentration according to a proposal, near-infrared light emitted from a light-emitting unit is obliquely irradiated to a finger that is a measurement site, and near-infrared reflected obliquely by the measurement site is irradiated. Detection is performed by the light receiving unit. (See Patent Document 2)
Furthermore, a blood glucose level measuring apparatus according to a proposal has a configuration in which a sensor having a light receiving element formed around a light emitting element is incorporated in a wristwatch (see Patent Document 3).

Japanese Patent No. 3566276 Japanese Patent No. 5090013 JP 2009-109927 A

However, in each of Patent Document 1 and Patent Document 2 described above, as shown in FIGS. 7 and 3, it is difficult to finely adjust the optical axis between the light emitting element and the light receiving element, and the near infrared ray that emits light. Since the amount of near infrared light received with respect to the amount of light decreases, there is a problem that the utilization efficiency of near infrared rays is reduced.
In Patent Document 3, as shown in FIG. 55, it is difficult to measure with high accuracy unless the blood vessel of the user is located near the window position of the wristwatch-type blood glucose level measuring device. It is.
The present invention has been made in order to solve such a conventional problem, and does not require delicate optical axis adjustment between the light emitting element and the light receiving element and is constrained by the position of the blood vessel of the user. An object of the present invention is to provide a sugar content measuring apparatus capable of reducing blood sugar and measuring blood sugar levels.

The present invention is a sugar content measuring apparatus for measuring blood sugar data, wherein a plurality of lenses having a convex portion on one surface of a transparent plastic plate and a flat shape on the other surface are integrally molded. A lens substrate and a lens corresponding to each of the plurality of lenses formed on the other surface of the lens substrate by sequentially emitting a light beam of a specific wavelength having a high absorption rate according to the sugar content. A plurality of light-emitting elements to be transmitted and the other surface of the lens substrate, corresponding to each of the plurality of lenses, surrounding the light-emitting element by an inner edge close to the outer edge of the light-emitting element; and In a region defined by the inner edge and the outer edge outside the inner edge, a plurality of light receiving elements that receive the light having the wavelength transmitted through the corresponding lens and generate an electric signal indicating the intensity value of the light. And sequentially storing the light intensity values indicated by the electrical signals generated from the light receiving elements surrounding the light emitting elements that emit the light beam, and approaching the one surface of the lens substrate based on the stored plurality of intensity values An arithmetic circuit for calculating sugar content data of the target to be
It is characterized by having.

  According to the sugar content measuring apparatus of the present invention, it is possible to measure a blood sugar level without requiring a delicate optical axis adjustment between the light emitting element and the light receiving element and without being restricted by the position of the blood vessel of the user. The effect is obtained.

It is a figure which shows the optical component used for the sugar content measuring apparatus in the 1st Embodiment of this invention. It is a figure which shows the structure of the light emitting element and light receiving element in 1st Embodiment. It is a perspective view which shows the external appearance of the wristwatch-type sugar content measuring apparatus in 1st Embodiment. It is a figure which shows the structure of the electronic circuit accommodated in the main body and adapter of the sugar content measuring apparatus of FIG. It is a flowchart which shows the operation | movement of the blood glucose level detection process performed by CPU of FIG. It is a flowchart which shows the operation | movement of the search process for the blood glucose level analysis performed by CPU of FIG. It is a figure which shows the screen of the calibration mode displayed on the display part of the sugar content measuring apparatus in 1st Embodiment, and the screen of a measurement mode. It is the top view and side view which show the external appearance of the sugar content measuring apparatus in 2nd Embodiment. It is a figure which shows a mode that the optical filter in 2nd Embodiment is switched from the back surface of a sugar content measuring apparatus. It is a top view which shows the external appearance of the sugar content measuring apparatus in 3rd Embodiment.

Hereinafter, a first embodiment to a third embodiment of a sugar content measuring apparatus according to the present invention will be described with reference to the drawings.
The blood glucose level data includes glucose (glucose) (unit: mg / dl), which is an instantaneous blood glucose level that represents the current sugar content in blood as a unit mass, and hemoglobin (accumulated value of blood glucose level). Hb) A1C (unit:%).

  When a person's skin is irradiated with a light beam having a specific wavelength (for example, 900 nm to 1100 nm) of near infrared rays and the reflected light is received, the higher the sugar content in the blood, the more part of the irradiated light beam is. Since much is absorbed, the blood glucose level can be measured by measuring the intensity of the reflected light. Moreover, hemoglobin A1C can be measured by the cumulative value of blood glucose levels of several tens of days.

  FIG. 1 is a diagram showing optical components used in the first sugar content measuring apparatus. FIG. 1A is a plan view of a part of a lens substrate formed on a transparent plastic plate. FIG. 1B is a cross-sectional view of a part of the lens substrate along the line XX in FIG.

  1A and 1B, the lens 1 is located at the center of the regular hexagonal column region, has a convex portion on one surface of the lens substrate (on the right side in FIG. 1B), and the other surface. (Left side of FIG. 1B) has a flat shape. On this flat surface, the light emitting element 2 and the light receiving element 3 are formed with a transparent insulating film 4 made of silicon dioxide or the like interposed therebetween as shown in FIG.

  The light emitting element 2 emits a light beam having a specific range of wavelengths, specifically, a light beam having a wavelength λ of near infrared rays. As shown in FIG. 1A, the light receiving element 3 surrounds the light emitting element 2 by an inner edge close to the outer edge of the light emitting element 2 and is defined by an inner edge and an outer edge outside the inner edge (that is, an outer edge). In the donut-shaped region), light having a wavelength λ transmitted through the lens 1 is received and an electric signal indicating the intensity value of the light is generated. The center of the lens 1, the center of the light emitting element 2, and the center of the light receiving element 3 have the same optical axis 6.

  As shown in FIG. 1C, a plurality of optical units of a lens 1, a light emitting element 2, and a light receiving element 3 having a regular hexagonal column region as a unit are formed on the lens substrate. That is, a honeycomb (honeycomb) structure is constituted by a plurality of regular hexagonal column regions. However, the regular hexagonal lines shown in FIGS. 1A and 1C are virtually displayed to indicate the area occupied by each optical unit, and there is actually a boundary line like this line. Not to do.

In FIG. 1C, a plurality of optical units are centered on a lens 1 (0) on which a light emitting element 2 and a light receiving element 3 are formed, and a lens 1 (1), a lens 1 (2), and a lens 1 around the lens 1 (0). (3) ... are formed.
When the number of optical units on the lens substrate is Xi, Xi is represented by Xi = X (i−1) + 6i. Here, i is a positive integer. When i = 1, X1 = X0 + 6. Here, X0 = 1. Therefore, X1 = 7. That is, the minimum unit of the optical units (lens 1, light emitting element 2, light receiving element 3) constituting the lens substrate is seven.
In the case of i = 2, 3, 4,..., the number Xi of the optical units constituting the lens substrate is 19, 37, 61,.

FIG. 2 is a diagram illustrating the structure of the light emitting element 2 and the light receiving element 3 in the first embodiment. FIG. 2A is a cross-sectional view of the light-emitting element 2. The light emitting element 2 is composed of a PN junction light emitting diode. In the light-emitting element 2, a p-type semiconductor 2 a (anode) formed on the surface of the transparent insulating film 4 and an n-type semiconductor 2 b (cathode) formed thereon are PN-junctioned.
Further, a semiconductor circuit (not shown) is formed on the p-type semiconductor 2a and the n-type semiconductor 2b. This semiconductor circuit includes a drive circuit that causes a forward current as a drive signal to flow through the p-type semiconductor 2a and the n-type semiconductor 2b to emit a light beam having a wavelength λ, and a power supply line that supplies a voltage. The drive circuit is composed of a switch circuit that turns on (connects) or turns off (disconnects) the n-type semiconductor 2b (cathode) and a reference voltage of 0 volts in accordance with a control signal described later. The power supply line supplies a positive voltage to the p-type semiconductor 2a. Therefore, when the switch circuit is turned on, a forward current flows through the PN junction, and a light beam is emitted from the light emitting element 2.

FIG. 2B is a plan view of the light receiving element 3. FIG. 2C is a cross-sectional view taken along line YY in FIG. The light receiving element 3 is an example of a grounded-emitter phototransistor that receives light and generates an electrical signal. In the example shown in FIGS. 2B and 2C, the p-type semiconductor 3 a (base) is formed on the n-type semiconductor 3 b (emitter) formed on the surface of the transparent insulating film 4. Further, an n-type semiconductor 3c (collector) is formed on the p-type semiconductor 3a. The p-type semiconductor 3a receives light having a wavelength λ incident from the opening of the n-type semiconductor 3b.
Further, the above-described semiconductor circuit (not shown) is formed on the light receiving element 3. This semiconductor circuit includes a load resistor and an amplifier circuit connected to the n-type semiconductor 3c, a power supply line connected to the load resistor, and a selection circuit connected to the n-type semiconductor 3b. The selection circuit is configured by a switch circuit that turns on or off the n-type semiconductor 3b and a reference voltage of 0 volt by a control signal described later. Therefore, when the switch circuit is turned on, the phototransistor becomes active, and the light according to the light intensity incident on the p-type semiconductor 3a is output from the n-type semiconductor 3c. Of course, a grounded collector type can also be used.

  Next, a plurality of optical units (lens 1, light emitting element 2, light receiving element 3) composed of Xi pieces (7, 19, 37, 61...) And a plurality of optical units are formed. An apparatus for measuring sugar content using a semiconductor circuit will be described.

FIG. 3 is a perspective view showing an appearance of the wristwatch-type sugar content measuring apparatus 11 according to the first embodiment of the present invention. In FIG. 3A, the display unit 13, the four buttons 14 (14 a, 14 b, 14 c, 14 d) provided on one surface of the main body 12 of the sugar content measuring device 11, the belt 15, the fastener 16, and the belt 15. The solar cell 17 is formed.
When the sugar content measuring device 11 is attached to the user's wrist by the belt 15 and the clasp 16, the wrist is irradiated with a light beam having a wavelength λ from the back surface of the sugar content measuring device 11, that is, the surface opposite to the display unit 13. The
Although not shown in the drawing, the back surface of the sugar content measuring apparatus 11 is formed of a plastic member of an optical filter that transmits a light beam having a wavelength emitted from the light emitting element 2. In the present embodiment, an optical filter that blocks the wavelength of visible light and transmits light of about 900 nm or more is used. Therefore, when the back surface of the sugar content measuring apparatus 11 is applied to the palm, back of the hand, finger or other body part of the user, the light beam having the wavelength λ is irradiated to the part.

  In FIG. 3 (B), the adapter 18 has a cable 19 for mounting the sugar content measuring device 11 and connecting to a portable terminal or a personal computer described later. The cable 19 is constituted by a USB cable, for example.

  The adapter 18 is provided with a recess for mounting the sugar content measuring device 11. The surface of the recess is made of a total reflection member that totally reflects the light beam having the wavelength λ emitted from the light emitting element 2.

In addition, although not shown in the drawing, a communication optical unit (including a lens, a light emitting element, and a light receiving element) is formed at a position different from the plurality of Xi measurement optical units. Corresponding to the optical unit for communication, an optical communication connector (not shown) of the cable 19 for communicating with a portable terminal or a personal computer is formed in the concave portion of the adapter 18.
Further, a charging connector (not shown) for contacting the charging connector on the back surface of the sugar content measuring device 11 is formed in the concave portion of the adapter 18.

FIG. 4 is a diagram illustrating a configuration of an electronic circuit housed in the main body 2 and the adapter 18 of the sugar content measuring device 11. 4A, the display unit 13 and the button 14 shown in FIG. 3 are connected to the control unit 30, and the communication unit 31, the clock unit 32, the infrared light emitting unit 33, and the infrared light receiving unit 34 are connected to the control unit 30. ing.
Further, the main body 12 of the sugar content measuring apparatus 11 incorporates the solar battery 17 and the rechargeable battery 35 shown in FIG. 3 in order to supply the power supply voltage Vcc to the electronic circuit.

  The infrared light emitting unit 33 is a decoding circuit that decodes the control signals in order to cause the plurality of light emitting elements 2 to emit light sequentially, that is, alternatively, in accordance with a control signal from the control unit 30. For example, when the number of optical units is 61, the decoding circuit decodes a 6-bit control signal output from the control unit 30 and outputs 1 of the light emitting elements 2 from 0 to 60. A drive circuit (semiconductor circuit formed on the lens substrate) for driving the two light emitting elements 2 is activated (the n-type semiconductor 2b and the reference voltage are connected).

The infrared light receiving unit 34 converts an analog signal supplied from an amplifier circuit connected to the light receiving element 3 into a digital signal and inputs the digital signal to the control unit 30 and a control signal from the control unit 30 Thus, a decoding circuit for selecting one of the plurality of light receiving elements 3 is configured.
The selection circuit included in the semiconductor circuit formed on the lens substrate is connected to the n-type semiconductor 3b (emitter) of one light receiving element 3 and the reference voltage 0 in accordance with a control signal supplied from the encoding circuit of the infrared light receiving unit 34. The light receiving element 3 which is a phototransistor is activated by connecting to the bolt.
In the case where 61 optical units are configured, the decoding circuit of the infrared light receiving unit 34 decodes the 6-bit control signal output from the control unit 30, and the light receiving elements 3 from 0 to 60 are decoded. One of the light receiving elements 3 is activated (the n-type semiconductor 3b and the reference voltage are connected).

  As described above, the light emitting element 2 and the light receiving element 3 corresponding to each of the plurality of optical units emit light beams sequentially in accordance with the control signal from the control unit 30 and irradiate the wrist of the user. The reflected light is received and an electric signal indicating the intensity value of the reflected light is generated.

  When the sugar content measuring device 11 is attached to the adapter 18, the communication unit 31 executes communication processing between an external portable terminal or personal computer connected to the adapter 18 via the cable 19 and the control unit 30.

  The communication unit 31 outputs an optical signal input from the control unit 30 to the optical communication connector of the adapter 18 via the light emitting element of the optical unit for communication described above. Further, the communication unit 31 outputs an optical signal input from the optical communication connector of the adapter 18 to the light receiving element of the optical unit for communication of the sugar content measuring apparatus 11.

  Since the clock unit 32, the solar cell 17, and the secondary battery 35 are the same as those in the prior art, a detailed description thereof is omitted. The contents displayed on the display unit 13 and the operation of the button 14 will be described later.

  FIG. 4B is a diagram illustrating an internal configuration of the control circuit 30. The control circuit 30 includes a CPU 301 that is an arithmetic circuit, an SRAM 302 that is a first storage circuit backed up by a battery, an EEPROM 303 that is a rewritable nonvolatile second storage circuit, and an internal bus 304 that connects them. . Although not shown in the figure, a memory (for example, a register in the CPU) that temporarily stores data to be processed is provided in the CPU 301.

  FIG. 4C is a diagram showing a connection state of the sugar content measuring device 11, the adapter 18, and an external device (mobile terminal or personal computer) 20. The adapter 18 includes an optical / electric conversion unit 181, a communication control unit 182, and a charging unit 183.

  The light / electricity conversion unit 181 converts the optical signal input from the communication unit 31 of the sugar content measurement device 11 into an electrical signal and outputs the electrical signal to the communication control unit 182. The light / electricity conversion unit 181 converts the electrical signal input from the communication control unit 182 into an optical signal and outputs the optical signal to the communication unit 31 of the sugar content measurement device 11.

  The communication control unit 182 processes information transmitted and received between the external device 20 and the sugar content measuring device 11. The external device 20 can access a medical institution server (not shown) that manages various data for the treatment and prevention of diabetes via a network such as the Internet.

  The charging unit 183 charges the secondary battery 35 of the sugar content measuring device 11 with a power source of an AC / DC converter (not shown) of the adapter 18 or with a power source supplied through the external device 20. For this purpose, an opening is formed in a part of the plastic member on the back surface of the sugar content measuring apparatus 11 shown in FIG. 3, and a charging connector for charging the rechargeable battery 35 is exposed.

  In the present embodiment, the rated voltage of the secondary battery 35 is slightly lower than the rated voltage of the solar battery 17. Therefore, normally, when the voltage Vcc from the solar cell 17 is supplied to the sugar content measuring device 11 and there is no external light or when the voltage of the solar cell 17 is lower than the rated voltage of the secondary battery 35 when not enough, The voltage Vcc from the secondary battery 35 is supplied to the sugar content measuring device 11.

Next, the operation and operation of the sugar content measuring apparatus 11 will be described.
Of the four buttons 14 (14a, 14b, 14c, 14d) shown in FIG. 3, the button 14b is the mode button “M”, the buttons 14a and 14c are the mode switching buttons “U” and “D”, and the button 14d is Start button “S”.

The mode button “M” is a button for displaying the current mode on the display unit 13 by an ON operation. The mode includes “clock mode (normal mode)”, “single measurement mode”, “continuous measurement mode”, “calibration (CALIBRATION) mode”, “data transmission mode”, “program update mode”, and the like.
The mode switching buttons U and D are buttons for shifting from the current mode to another mode (U: upshift / D: downshift).
The start button S is a button for starting processing in the current mode except for the clock mode. When the start button S is turned on again after starting the current mode process, the mode process is stopped and the mode is changed to the normal mode.

  The CPU 301 of the control unit 30 detects the on operation of the four buttons 14 in accordance with the program stored in the EEPRM 302 and executes a process according to the button operation. For example, when the start button S is turned on in the “single measurement mode”, a light beam is sequentially emitted from the light emitting elements 2 of the plurality of optical units, and the reflected light is received to measure the blood glucose level of the user. To do. When the start button S is turned on in the “continuous measurement mode”, the blood glucose level is measured at regular intervals of a 24-hour period.

  When the start button S is turned on in the “calibration mode”, the reflected light with respect to the light beam sequentially emitted from each of the plurality of light emitting elements 2 is received by the corresponding light receiving element 3, and the intensity value of the reflected light is determined. The reference value of each lens 1, each light emitting element 2, and each light receiving element 3 is stored in the SRAM 302.

  When the start button S is turned on in the “data transmission mode”, the blood glucose level data stored in the SRAM 302 is transmitted to the external device 20. When the start button S is turned on in the “program update mode”, the blood sugar level detection processing program stored in the EEPROM 303 is updated by a program transmitted from the medical institution via the external device 20. A program for blood glucose level detection processing will be described later.

  Next, the operation of the blood sugar level detection process executed by the CPU 301 that is an arithmetic circuit in the single measurement mode will be described. In the first embodiment, a plurality of optical units (lens 1, light emitting element 2, light receiving element 3) and corresponding semiconductor circuits (light emitting element 2 drive circuit, light receiving element 3 selection circuit) are arranged in m groups. Each group is composed of n optical units and semiconductor circuits. Then, light beams having different wavelengths are emitted for each group.

  FIG. 5 is a flowchart showing the blood glucose level detection process performed by the CPU 301. When the single measurement mode is selected in the main flow (not shown), the CPU 301 transitions to the processing in FIG. In FIG. 5, each optical unit including the lens 1, the light emitting element 2, and the light receiving element 3 serving as a detection unit for blood glucose level measurement and each corresponding semiconductor circuit are referred to as “cell”.

  The CPU 301 first executes calibration processing (step S101). In the calibration process, the CPU 301 displays a message to the effect that the sugar content measuring device 11 is attached to the adapter 18 on the display unit 13. As to whether or not the sugar content measuring device 11 is attached to the adapter 18, the CPU 301 emits a light beam from the light emitting element 2 of the central optical unit corresponding to the lens 1 (0) shown in FIG. Then, it is determined whether or not the intensity of the light totally reflected by the adapter 18 is received by the light receiving element 3.

  When it is confirmed that the sugar content measuring device 11 is attached to the adapter 18, the CPU 301 sequentially emits a light beam from each light emitting element 2, and calculates the intensity value of the reflected light obtained from the corresponding light receiving element 3 for each optical light. Stored in the SRAM 302 as a reference value of a unit (including a semiconductor circuit). After the calibration process, the CPU 301 transitions to the measurement mode and displays a message that prompts the user to press the start button S to start the measurement.

  The CPU 301 determines whether or not the start button S has been turned on (step S102). When the start button S is not turned on (step S102; NO), the CPU 301 performs button processing for detecting whether another button is turned on (step S103). That is, processing for determining whether the mode button M or the mode switching button U or D is turned on is performed.

  When the start button S is turned on (step S102; YES), the CPU 301 designates a variable j that designates m groups of a plurality of optical units and semiconductor circuits, and n optical units and semiconductor circuits in the groups. Each variable k to be set is set to “1” (step S104). And CPU301 repeats the process from step S105 to step S111, updating these variables.

  The CPU 301 causes the light emitting element 2 of the cell (j; k) designated by the variables j and k to emit light with the light beam having the wavelength λ (j) (step S105). The emitted light beam is applied to the body part of the user, and the reflected light is received by the light receiving element 3 of the cell (j; k).

  The CPU 301 detects the intensity of the reflected light received by the light receiving element 3 of the cell (j; k) (step S106). Next, the CPU 301 stores the intensity value of the reflected light in the storage area (j; k) of the SRAM 302 (step S107).

  Next, the CPU 301 increments the variable k (step S108). Then, the CPU 301 determines whether or not the value of the incremented variable k has exceeded the total number n of cells in the group (j) (step S109). If the value of the variable k does not exceed the total number n of cells in the group (step S109; NO), the CPU 301 proceeds to step S105 and repeats the processing up to step S109.

  In step S109, when the value of the variable k exceeds the total number n of cells in the group (step S109; YES), the CPU 301 increments the variable j designating the group, and the variable of the cell in the group. Is set to "1" (step S110).

  In this case, the CPU 301 determines whether or not the value of the incremented variable j has exceeded the total number m of groups (step S111). When the value of the variable j does not exceed the total number m of groups (step S111; NO), the CPU 301 proceeds to step S105 and repeats the processing up to step S111.

  In step S111, when the value of the variable j exceeds the total number m of groups (step S111; YES), the CPU 301 returns to the main flow.

  Next, the CPU 301 normalizes the intensity value of each optical unit (including the semiconductor circuit) stored in the SRAM 302 with a reference value stored in advance in the SRAM 302 before measurement. That is, the variation of each optical unit is corrected.

  In the main flow, when the blood glucose level detection process stop process (returning on the start button S) is not performed, the CPU 301 executes a storage area search process of the SRAM 302. FIG. 6 is a flowchart of the search process.

  In FIG. 6, the CPU 301 sets variables j and k for designating the arrangement of storage areas in the SRAM 302 and a variable r for the number of samples corresponding to the analysis target to “1” (step S201). Next, the CPU 301 repeats the processing from step S202 to step S211 while changing the variable.

  The CPU 301 searches the storage area (j; k) of the SRAM 302 (step S202) and determines whether or not the intensity value of the stored reflected light is less than the threshold value (th) (step S203). That is, it is determined whether or not the amount of the light beam absorbed by the sugar in the blood exceeds a preset amount. When the intensity value of the reflected light is large, the sugar content in the blood is low, but the irradiated light beam may be out of the blood vessel position. Therefore, in order to confirm that the irradiated light beam is a blood vessel position, a threshold value obtained experimentally is set in advance.

  If the intensity value of the reflected light is less than the threshold value (step S203; YES), the CPU 301 stores the intensity value as an analysis target in the analysis storage area of the register (step S204). Further, the value of the variable r is incremented (step S205).

  After step S205 or when the intensity value of the reflected light is greater than or equal to the threshold value in step S203 (step S203; NO), the CPU 301 increments the value of the variable k (step S206). Next, the CPU 301 determines whether or not the value of the incremented variable k exceeds the upper limit value n of k in the storage area array {j; k} (step S207).

  When the value of the variable k does not exceed the upper limit value n (step S207; NO), the CPU 301 proceeds to step S202 and repeats the processing up to step S207. On the other hand, when the value of the variable k exceeds the upper limit value n (step S207; YES), the CPU 301 increments the value of the variable j (step S208).

  Next, the CPU 301 determines whether or not the value of the incremented variable j has exceeded the upper limit value m of j in the storage area array {j; k} (step S209). When the value of the variable j does not exceed m (step S209; NO), the CPU 301 proceeds to step S202 and repeats the processing up to step S209.

  On the other hand, when the value of the variable j exceeds m (step S209; YES), the CPU 301 determines whether the ratio between the value of r and the total number of optical units (n × m) is less than a certain ratio P. A determination is made (step S210).

  When the ratio between the value of r and the total number of optical units is P or more (step S210; NO), it is necessary to narrow down the number of samples to be analyzed in order to increase the accuracy of blood glucose level measurement. In this case, the CPU 301 decrements the value of the threshold th (step S211), proceeds to step S202, and repeats the processing up to step S210 again. For example, if the value of P is “0.1” and the total number of optical units is 61, the value of the threshold th is decremented until the value of r becomes “6”, and the processing from step S202 to step S210 is performed. repeat.

  In step S210, when the ratio between the value of r and the total number of optical units is less than P (step S210; YES), the CPU 301 returns to the main flow.

  Thereafter, the CPU 301 selects the minimum intensity value from the intensity values of the reflected light less than the threshold value stored in the analysis storage area of the register, and calculates the blood sugar level based on the program stored in the EEPROM 303. . Specifically, the blood glucose level is specified with reference to the correspondence table between the intensity value of reflected light and the blood glucose level, stored in the SRAM 302 and displayed on the display unit 13.

  As a modification of the first embodiment, the CPU 301 calculates sugar content data based on an average value of intensity values less than a finally set threshold value (th) among a plurality of stored intensity values. You may do it.

  Further, the CPU 301 calculates hemoglobin A1C based on the blood glucose level in the past predetermined period (in this embodiment, 30 days in the present embodiment) stored in the SRAM 302 and the program in the EEPROM 303 and displays the hemoglobin A1C on the display unit 13.

  FIG. 7 is a diagram showing a calibration mode screen and a measurement result screen displayed on the display unit 13 of the sugar content measuring apparatus 11. FIG. 7A is a calibration mode screen displayed on the display unit 13. FIG. 7B is a measurement result screen displayed on the display unit 13.

  As shown in FIG. 7A, when the CPU 301 confirms that the sugar content measuring device 11 is attached to the adapter 18 in the calibration mode, a message prompting the user to press the start button S is displayed.

  As shown in FIG. 7B, when the measurement result is found in the single measurement mode, the CPU 301 displays the blood glucose level and hemoglobin A1C, which are blood glucose data, and saves the measurement result. Displays a message to select

  Next, a second embodiment of the present invention will be described. FIG. 8 is a plan view and a side view showing the appearance of the sugar content measuring apparatus 11 in the second embodiment. The sugar content measuring apparatus 11 in the second embodiment is configured as the sugar content measuring apparatus 11 in the first embodiment shown in FIGS. 1, 2, 4 (A), (B), 5, and 6. Is almost the same. Therefore, while using these figures as appropriate, the sugar content measuring apparatus 11 of the second embodiment will be described focusing on the differences from the first embodiment.

  Of the buttons of the sugar content measuring apparatus 11 in the second embodiment, the start button “S” 14d is provided at the same position as the start button “S” 14d in the first embodiment, but the mode button “M”. 14e is provided at a position different from that of the first embodiment. In the second embodiment, the mode change buttons “U” and “D” are not provided. Mode switching in the second embodiment is performed cyclically by pressing the mode button M.

In the second embodiment, a special optical filter used in the calibration mode is provided in the sugar content measuring apparatus 11. This optical filter has a property of transmitting visible light having a wavelength of about 350 nm to 700 nm, but totally reflecting near infrared light having a wavelength of about 900 nm to 2500 nm. Examples of the optical filter that transmits visible light and totally reflects near-infrared light include high-refractive-index materials such as TiO ₂ , ZrO ₂ , Ta ₂ O ₅ , and Nb ₂ O ₅ , SiO ₂ , MgF _{2, and the} like. A dielectric multilayer plate in which a low refractive index material is alternately laminated on a transparent substrate is employed.

  FIG. 8A shows that in the calibration mode, an optical filter 41 that transmits visible light and totally reflects near-infrared rays is in contact with the back surface of the sugar content measuring device 11, that is, the surface opposite to the display unit 13. Indicates the state. The optical filter 41 has a substantially “U” shape in cross section, and is attached to the main body 12 of the sugar content measuring device 11 by a hinge 42. The hinge 42 has two rotation axes. In FIG. 8A, a y-axis indicated by a vertical arrow is a main axis for rotating the optical filter 41 and switching a surface (back surface or surface) that is in contact therewith. On the other hand, the x-axis indicated by the horizontal arrow is a sub-axis for rotating the optical filter 41 rotated 180 degrees by the main axis by the mechanism of the central portion 42a of the hinge 42. The rotation of the optical filter 41 will be described later.

  In the state shown in FIG. 8A, when the user presses the start button S according to the message on the display unit 13, the near infrared light beam from the light emitting element is reflected on the optical filter 41 on the back surface of the sugar content measuring device 11. Is totally reflected and received by the light receiving element. Therefore, as in the case of the sugar content measuring device 11 attached to the adapter 18 in the first embodiment, the CPU 301 uses the intensity value of the reflected light obtained from the light receiving element as a reference value for each optical unit (including a semiconductor circuit). It can be stored in the SRAM 302.

  After storing the reference value, the CPU 301 displays a message on the display unit 13 indicating that the calibration process has been completed, and prompting the user to move the optical filter 41 by operation to bring it into contact with the surface of the sugar content measuring device 11. To do.

  FIG. 9 is a diagram illustrating a state in which the optical filter 41 is switched from the back surface to the surface of the sugar content measuring device 11. FIG. 9A shows a state in which the optical filter 41 is in contact with the back surface of the main body 12 of the sugar content measuring apparatus 11, that is, a calibration mode. FIG. 9B shows a state in the middle of rotating the optical filter 41 around the main axis of the hinge 42. FIG. 9C shows a state in which the optical filter 41 is rotated 180 degrees. The rotation of the spindle is stopped at this position by a stopper. FIG. 9D shows a state in the middle of rotating the optical filter 41 about the auxiliary shaft of the hinge 42. FIG. 9E shows a state in which the optical filter 41 is rotated 180 degrees around the sub-axis. The rotation of the countershaft is stopped at this position by the stopper. FIG. 9F shows a state in which the optical filter 41 rotated around the main axis of the hinge 42 from the state of FIG. State.

  FIG. 8B shows a state in which the measurement result in the single measurement mode is displayed on the display unit 13 of the sugar content measuring device 11. Since the optical filter 41 covering a part of the display unit 13 transmits visible light, the user can easily recognize the measurement result of the display unit 13.

  In the second embodiment, the communication unit 31 illustrated in FIG. 4 communicates with an external personal computer or the like by short-range wireless communication such as Bluetooth (registered trademark) instead of the optical signal in the first embodiment. Therefore, when the start button S is turned on in the “data transmission mode”, the CPU 301 can transmit the blood sugar level information stored in the internal register to a medical institution server through a personal computer or the like. Further, when the start button S is turned on in the “program update mode”, the CPU 301 can update the blood sugar level detection processing program stored in the EEPROM 303 with a program transmitted from a medical institution through a personal computer or the like. it can.

  Next, a third embodiment of the present invention will be described. FIG. 10 is a plan view showing the appearance of the sugar content measuring apparatus 21 in the third embodiment. The sugar content measuring device 21 is a desktop sugar content measuring device. The sugar content measuring device 21 in the third embodiment is configured as the sugar content measuring device 11 in the first embodiment shown in FIGS. 1, 2, 4 (A), (B), 5, and 6. Is almost the same. Therefore, while using these figures as appropriate, the sugar content measuring apparatus 21 of the third embodiment will be described with a focus on the differences from the first embodiment.

  As shown in FIG. 10A, the sugar content measuring device 21 includes a main body 22, a display unit 23, four buttons 24, and a cover 25. The cover 25 is attached to the main body 22 so as to be opened and closed by a hinge (not shown). When the hook switch 26 of the main body 22 is pressed, the cover 25 can be opened as shown in FIG. In addition, the sugar content measuring device 21 can be connected to an external device (not shown) by a cable 29.

  10B, the main body 22 with the cover 25 opened is provided with a detection unit 27 for the user to measure the blood sugar level by touching the palm or finger. The detection unit 27 includes an optical filter, a plurality of optical units (lens, light emitting element, light receiving element), a semiconductor circuit, and the like as in the first embodiment, as shown in FIGS. 4A and 4B. A circuit is provided.

  A message prompting the user to press the start button S in the calibration mode is displayed on the display unit 23 shown in FIG. In the calibration mode, the reference value of the intensity of the reflected light of each optical unit for normalizing the intensity of the reflected light detected in the measurement mode by the reflecting member 28 shown in FIG. Can be obtained. Similar to the first embodiment, the blood glucose level and the measurement result of hemoglobin A1C are displayed on the display unit 23 shown in FIG.

  As a modification of the first to third embodiments, all the optical units may emit light beams having the same wavelength.

DESCRIPTION OF SYMBOLS 1 Lens 2 Light emitting element 3 Light receiving element 11, 21 Sugar content measuring apparatus 30 Control part 41 Optical filter 301 CPU (arithmetic circuit)

Claims (5)

A sugar content measuring device for measuring blood sugar data,
A lens substrate having a convex portion on one surface of a transparent plastic plate and a plurality of lenses having a flat shape on the other surface;
On the other surface of the lens substrate, a plurality of light beams of a specific wavelength that are formed corresponding to each of the plurality of lenses and have an absorptance that increases in accordance with the sugar content and sequentially pass through the corresponding lenses. A light emitting device of
The other surface of the lens substrate is formed corresponding to each of the plurality of lenses, surrounds the light emitting element by an inner edge adjacent to the outer edge of the light emitting element, and has an outer edge outside the inner edge and the inner edge. A plurality of light receiving elements that receive light of the wavelength that is transmitted through a corresponding lens and generate an electrical signal indicating an intensity value of the light in a region defined by
A light intensity value indicated by an electrical signal generated from a light receiving element surrounding a light emitting element that emits a light beam is sequentially stored, and an object close to the one surface of the lens substrate based on the stored plurality of intensity values An arithmetic circuit for calculating sugar content data of
A sugar content measuring apparatus comprising:   The sugar content measuring apparatus according to claim 1, wherein the arithmetic circuit calculates sugar content data based on a smallest strength value among a plurality of stored strength values.   The sugar content measuring apparatus according to claim 1, wherein the arithmetic circuit calculates sugar content data based on an average value of intensity values less than a preset threshold value among a plurality of stored intensity values.   A button for setting a calibration mode or a measurement mode according to an operation, and a reflecting member that is close to the one surface of the lens substrate according to a moving operation and reflects a light beam having the wavelength emitted by the light emitting element. The arithmetic circuit further includes: when the light receiving element corresponding to the reflected light from the reflecting member receives light beams sequentially emitted from the plurality of light emitting elements in the calibration mode; Is stored as a reference value for each lens, each light emitting element and each light receiving element, and in the measurement mode, the stored light intensity value is normalized with the reference value to calculate sugar content data. The sugar content measuring apparatus according to any one of claims 1 to 3, wherein   The sugar content measuring apparatus according to claim 4, wherein the reflecting member is an optical filter that transmits visible light and reflects the light beam having the specific wavelength.

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