JP5625555B2 - Blood glucose concentration measuring device - Google Patents

Description

  The present invention relates to a portable blood glucose concentration measuring device that easily determines whether or not a measured blood glucose concentration is a normal value based on the background color of a display screen.

  In recent years, the number of diabetic patients is increasing in each country. An example of a treatment for diabetes is insulin therapy. Insulin is known as a drug that controls blood glucose levels and is administered to diabetic patients as a therapeutic agent for diabetes. The need to administer insulin is determined based on the blood glucose level of the diabetic patient. For this reason, grasping the blood glucose level is important for diabetic patients. The blood glucose level is the glucose concentration in the blood. For the purpose of allowing a diabetic patient to easily measure his / her blood glucose level, a small portable blood glucose measuring device has been developed.

  The measured blood glucose level can be displayed on a liquid crystal display or the like provided in the main body. Thereby, the measured blood glucose level can be confirmed. For such a liquid crystal display, a monochrome liquid crystal display is often used for reasons such as low cost and power saving.

  By the way, it is known that the readability of a liquid crystal display greatly depends on the illumination intensity of ambient light. Therefore, it becomes difficult to recognize the displayed blood glucose level in an environment where light is weak. In addition, there are generally many elderly people who use blood glucose measuring devices, and many elderly people are blind. Furthermore, since the blood glucose measuring device is configured in a small size, it becomes more difficult for the user to recognize the displayed blood glucose level. In addition, even if the blood glucose level displayed can be recognized, it is often the case that a patient without specialized knowledge cannot determine whether or not it is a normal value.

  2. Description of the Related Art A portable medical system including a display element including an organic light emitting diode display device and an optimization device for optimizing luminance, contrast, and power consumption is known for improving the readability of a liquid crystal display. (Patent Document 1).

  In addition, in order to easily determine whether or not the blood glucose level is a normal value, there is provided a blood glucose measuring device that displays any one of five colors on the screen according to the displayed blood glucose level. Are known. For example, a bar of blue, light blue, green, orange, or red is displayed at the bottom of the screen according to the blood glucose level being displayed (Non-Patent Document 1).

Special table 2009-517153

"One Touch Ultraview TM Self Test Glucose Meter Instruction Manual", Johnson & Johnson Medical Company, p27

  Since self-measurement of blood glucose levels is important for many diabetics, it is desirable that the equipment be as inexpensive as possible. However, the use of a color liquid crystal display increases the manufacturing cost of the device.

  Since a portable blood glucose measurement device is carried by a patient, it is required to operate continuously for a long time. By the way, in many portable blood glucose measuring devices, a dry battery or a button-type lithium battery is employed as a power source in order to reduce manufacturing cost and miniaturization, and many of them do not have a charging function. In such a blood glucose measurement device, low power consumption is particularly important. However, color liquid crystal displays consume more power than monochrome liquid crystal displays. Therefore, the blood glucose measurement device using a color liquid crystal display has a shorter operation time than that using a monochrome liquid crystal display.

  In terms of displaying characters, it is said that a monochrome liquid crystal display has a higher readable property than a color liquid crystal display.

  The present invention has been made in view of the above-described circumstances, and its purpose is to change the background color of a monochrome liquid crystal display according to the displayed glucose concentration, and based on the background color, the glucose concentration is normal. It is an object of the present invention to provide a portable blood glucose concentration measuring device that can easily determine whether or not the value is a value.

  (1) A portable blood glucose concentration measurement device according to the present invention is configured to transmit a measurement unit that generates a signal indicating glucose concentration in blood and at least a part of light irradiated on the back surface to the display surface. A monochrome liquid crystal display capable of illuminating, and capable of irradiating a plurality of colors of light using a display unit for displaying glucose concentration and an LED as a light source, from the back side of the monochrome liquid crystal display toward the monochrome liquid crystal display A backlight unit capable of irradiating any one of the light of the plurality of colors, a power source for supplying power to the backlight unit, and a glucose concentration value displayed on the display unit. One of the colors of light that can be irradiated by the light unit is determined, and the backlight unit is irradiated with the light of the determined color, and the display unit is And a control unit for displaying the concentration.

  Here, the monochrome liquid crystal display in the present invention is a liquid crystal display that does not include a color filter and does not support color display. The monochrome liquid crystal display includes those realized by any driving method and display method.

  The measurement unit generates and outputs a signal indicating the glucose concentration in the blood based on the operation of the operator. The display unit displays the glucose concentration as a numerical value based on the output signal. The backlight unit emits light of a color corresponding to the glucose concentration. The light emitted from the backlight unit is transmitted through the display surface of the display unit. As a result, the display unit emits light in a color corresponding to the displayed glucose concentration. The operator can determine the state of the glucose concentration based on the emission color of the display unit.

  (2) In the portable blood glucose concentration measurement device according to the present invention, the control unit has a data table associating a threshold value corresponding to the glucose concentration with a color of light that can be irradiated by the backlight unit. You may memorize | store and determine the color of the light with which the said backlight part is irradiated based on the said data table.

  The threshold value defines a plurality of numerical ranges corresponding to the glucose concentration. The low numerical value range can be associated with a blue color, and the high numerical value range can be associated with a red color. The control unit causes the backlight unit to emit light having a color corresponding to a numerical range to which the displayed glucose concentration belongs. As a result, the display unit emits red light when the glucose concentration is high, and emits blue light when the blood glucose concentration is low. The operator can intuitively determine the height of the glucose concentration based on the emission color of the display unit.

  (3) The portable blood glucose concentration measurement device according to the present invention may further include an operation unit that receives an operation by an operator and outputs an operation signal corresponding to the operation. The control unit may update the threshold value of the data table to a threshold value indicated by the operation signal on condition that an operation signal instructing the update of the threshold value is output from the operation unit.

  The threshold value can be updated by an operation signal output from the operation unit. Therefore, the doctor can set an optimal threshold according to the patient's health condition.

  (4) In the portable blood glucose concentration measuring device according to the present invention, the control unit is preset with a time for displaying the glucose concentration on the display unit, and the display unit displays the glucose concentration on the display unit. Only during the display, the backlight unit may be irradiated with light.

  Since the glucose concentration is displayed for a certain period of time, the battery consumption is reduced.

  (5) In the portable blood glucose concentration measuring apparatus according to the present invention, the light source of the backlight unit may be a full color LED.

  Here, the full-color LED in the present invention refers to an LED element that can simultaneously irradiate red, blue, and green light and can individually adjust the intensity of light of three colors.

  Since the full-color LED can irradiate light of any color with one LED element, the blood glucose concentration measuring device can be easily miniaturized.

  (6) In the portable blood glucose concentration measuring apparatus according to the present invention, the monochrome liquid crystal display may be a transflective monochrome liquid crystal display.

  Here, the transflective monochrome liquid crystal display in the present invention is a monochromatic liquid crystal in which a transflective film that reflects part of incident light and transmits part of light is laminated on the surface opposite to the display surface. Refers to a liquid crystal display.

  (7) In the portable blood glucose concentration measuring apparatus according to the present invention, the power source may be a dry battery or a lithium battery.

  As a result, the manufacturing cost of the blood glucose concentration measuring device can be reduced as compared with a built-in rechargeable battery.

  According to the blood glucose concentration measuring apparatus configured as described above, a visually impaired patient or a patient without specialized knowledge can easily determine whether or not the blood glucose concentration is a normal value. it can. In addition, since a monochrome liquid crystal display is adopted, the battery consumption is small and the character readable property is high. Such a blood glucose concentration measuring device is manufactured at low cost.

FIG. 1 is a perspective view showing an appearance of a blood glucose concentration measuring apparatus 10 according to an embodiment of the present invention. FIG. 2 is a functional block diagram of the blood glucose concentration measuring apparatus 10 according to the embodiment of the present invention. FIG. 3 is a perspective view showing an appearance of the light emitting device 30. FIG. 4 is a schematic view showing a laminated structure of the liquid crystal display 40 and the light emitting device 30. FIG. 5 is a conceptual diagram showing data constituting the data table. FIG. 6 is a flowchart showing a process performed by the control unit 27 when the glucose concentration is displayed. FIG. 7 is a diagram showing an example of a screen on which the glucose concentration is displayed. FIG. 8 is a diagram showing an example of the setting screen 70.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings as appropriate. Each embodiment described below is only an example of the present invention, and it is needless to say that the embodiment of the present invention can be changed as appropriate without departing from the gist of the present invention.

[Schematic configuration of blood glucose concentration measuring apparatus 10]

  FIG. 1 is a perspective view showing an appearance of a blood glucose concentration measuring apparatus 10 according to an embodiment of the present invention. As shown in the figure, the blood glucose concentration measuring device 10 is configured such that a sensor 15 is detachably attached to the main body 11. The main body 11 has a thin box shape. On the front side of the main body 11, a display screen 12 and three operation buttons 13A, 13B, 13C are provided. The display screen 12 is a transflective monochrome liquid crystal display and forms a part of the display unit 23 described later. The display screen 12 can display blood sugar levels and information necessary for operating the device. The operation buttons 13A, 13B, and 13C form a part of the operation unit 25 described later, and generate predetermined operation signals when pressed by the user. The number of operation buttons 13A, 13B, 13C and the like are appropriately designed. Moreover, the blood glucose concentration measuring apparatus 10 is configured such that a dry battery or a lithium battery can be used as a power source.

  A sensor insertion opening 14 is provided on the side surface of the main body 11. The sensor insertion port 14 is for the sensor 15 to be inserted and held. Although not shown in the figure, an electrode is provided in the back of the sensor insertion port 14, and the control unit 27 of the main body 11 and the sensor 15 are connected through the electrode so as to be able to transmit an electric signal. The sensor 15 introduces blood as a measurement sample, and causes an electrochemical reaction with glucose in the blood. Such a sensor 15 is known as a so-called biosensor. In the sensor 15, an electrochemical reaction with glucose in the blood occurs, and the control unit 27 receives the current generated in the reaction. The sensor 15, the electrode of the sensor insertion port 14, and the like constitute the measurement unit 21.

[Internal structure of main body 11]

  FIG. 2 is a functional block diagram of the blood glucose concentration measuring apparatus 10 according to the embodiment of the present invention. As shown in the figure, the main body 11 is provided with a control unit 27. The control unit 27 is an arithmetic unit configured by a CPU for performing various calculations, a ROM for storing various programs, a RAM for temporarily storing data for various calculations, a bus for transmitting data, and the like. The measurement unit 21, the storage unit 22, the display unit 23, the backlight unit 24, the operation unit 25, and the clock unit 26 are connected to the control unit 27 so as to be able to transmit and receive electrical signals.

  The control unit 27 stores various programs necessary for the operation of the device. To list typical ones, the stored program is a program for calculating the glucose concentration based on the current flowing through the sensor 15, a program for storing the glucose concentration in the storage unit 22, and displaying the glucose concentration on the display unit 23. And a program for controlling the timing at which the backlight unit 24 emits light and the color of light according to the display on the display unit 23.

  The measuring unit 21 generates an electrical signal corresponding to the glucose concentration by generating an electrochemical reaction with blood glucose introduced into the sensor 15 as a sample. The sensor 15 is provided with a working electrode and a counter electrode, and glucose dehydrogenase or glucose oxidase and a mediator are fixed to the working electrode. For example, glucose in the blood is decomposed into gluconic acid and hydrogen peroxide by glucose oxidase fixed to the working electrode, and the hydrogen peroxide is decomposed into water and electrons. The electrons generated in this way are transmitted to the working electrode. On the other hand, electrons are supplied from the counter electrode into the blood. In this way, a current flows between the working electrode and the counter electrode due to the reaction between glucose oxidase and glucose. Then, based on the flowing current value, the glucose concentration in the blood, that is, the blood glucose level is calculated. Such a reaction is referred to herein as an electrochemical reaction. The measurement unit 21 may be provided with a dedicated circuit for converting the electrical signal from the sensor 15 into a digital signal expressed numerically.

  The storage unit 22 includes a nonvolatile semiconductor memory and a peripheral circuit connected to the control unit 27. Further, a dedicated slot for a standardized flash memory may be provided in the main body 11, and the storage unit 22 may be configured as an external medium that can be attached and detached. The storage unit 22 stores the glucose concentration inside based on the control of the control unit 27. Therefore, when there is no need to confirm the stored glucose concentration afterwards, the storage unit 22 is not an essential component. Whether or not the blood glucose concentration measurement device 10 has a function of storing the glucose concentration can be appropriately determined by those skilled in the art. The storage unit 22 may be configured as a part of the control unit 27.

  The display unit 23 includes a liquid crystal display 40 described later and a peripheral circuit connected to the control unit 27. The liquid crystal display 40 is a transflective monochrome liquid crystal display. Characters and images can be displayed on the liquid crystal display 40 based on the control of the control unit 27. On the back surface of the liquid crystal display 40, a light emitting device 30 constituting the backlight unit 24 is provided. What is confirmed from the outside of the main body 11 is the display screen 12 described above.

  The backlight unit 24 includes a light emitting device 30 described later and a peripheral circuit connected to the control unit 27. The light emitting device 30 can selectively irradiate one of a plurality of colors of light using an LED as a light source. The light emitting device 30 provided on the back surface of the display screen 12 emits light of any color under the control of the control unit. Thereby, the backlight unit 24 functions as a backlight of the display unit 23.

  The operation unit 25 includes operation buttons 13A, 13B, and 13C provided on the main body 11, and peripheral circuits that generate predetermined operation signals corresponding to pressing of the operation buttons 13A, 13B, and 13C. For example, the operation button 13A accepts an input for mode selection or determination, and the operation buttons 13B and 13C accept an input for raising / lowering a numerical value or changing a menu. In response to the operation signal generated by the operation unit 25, the control unit 27 performs various operations. The operation unit 26 is not necessarily provided independently. For example, a pressure-sensitive or electrostatic touch panel sensor is provided so as to overlap the display screen 12, and the touch panel sensor is used as the operation unit 26. May function. The operation unit 26 receives various operations from the operator and outputs various operation signals. The control unit 27 controls the operation of each unit according to the output operation signal.

  The clock unit 26 is a built-in clock for the control unit 27 to acquire a time signal during blood glucose level measurement. The clock unit 26 has a crystal resonator for controlling the time signal. The clock unit 26 may include a receiver and a dedicated circuit that are linked to the terrestrial time information and automatically adjust the time. For example, the control unit 27 acquires a time signal at the timing when the blood glucose concentration is measured. And the measurement date obtained from there can be displayed on the display part 23 with a measured value. Therefore, when the measurement date and time need not be displayed together with the glucose concentration, the clock unit 26 is not an essential component. Whether or not the blood glucose measuring device 10 has a function of displaying the measurement date and time together with the measurement value can be appropriately determined by those skilled in the art.

[Light Emitting Device 30]

  Subsequently, a detailed configuration of the above-described light emitting device 30 will be described. FIG. 3 is a perspective view showing an appearance of the light emitting device 30. As shown in the figure, the light emitting device 30 includes an LED light source 31 and a light guide plate 32. An LED element 36 is provided inside the LED light source 31. In the LED element 36, RGB three-color LEDs are sealed inside the bulb. The light intensity of each color can be adjusted by the control unit 27. Thereby, the LED element 36 can emit light of any color that can be expressed by the balance of the three primary colors. Such an LED element 36 is generally known as a full-color LED.

  The light guide plate 32 is made of a glass plate or an acrylic plate. The light irradiated by the LED element 36 enters the light guide plate 32 from the joint surface 35. The light incident on the light guide plate 32 is propagated to the right side in the figure while being reflected between the diffusing surface 33 and the reflecting surface 34. A reflection sheet that reflects light is attached to the reflection surface 34. A diffusion sheet is affixed to the diffusion surface 33. The diffusion sheet is a translucent sheet that scatters and diffuses light. Each time the propagated light is refracted by the diffusing surface 33, a part of the light is transmitted to the outside while being scattered and diffused. As a result, the entire diffusing surface 33 emits light with a substantially uniform amount of light.

  Next, the configuration and operation of the display unit will be explained. FIG. 4 is a schematic view showing a laminated structure of the liquid crystal display 40 and the light emitting device 30. As described above, the liquid crystal display 40 constitutes the display unit 23, and the light emitting device 30 constitutes the backlight unit 24. The light emitting device 30 is disposed on the back surface of the liquid crystal display 40. The upper surface of the liquid crystal display 40 in FIG.

[Liquid crystal display 40]

  The liquid crystal 45 is arranged in a state where liquid crystal molecules are arranged in a certain direction by the light distribution films 44 and 46. Although not shown in the drawing, a transparent electrode capable of applying a voltage to the liquid crystal 45 is connected to the light distribution films 44 and 46, and the transparent electrode is connected to the control unit 27 so that the voltage can be controlled for each cell. It is connected. The polarizing film (vertical) 47 and the polarizing film (horizontal) 43 arranged outside the light distribution films 44 and 46 are called polarizers, respectively, absorb polarized light in one direction of transmitted light, and are aligned in one direction. It transmits the linearly polarized light. The polarizing film (vertical) 47 and the polarizing film (horizontal) 43 are arranged so that their polarization directions intersect perpendicularly. Further, glass layers 42 and 48 capable of protecting these layers and transmitting light are provided on the outer side, and a transflective film 41 is provided on the outer side of the glass layer 42. The transflective film 41 reflects a part of the light incident from the display surface side and transmits the rest.

  Light incident from the display surface side becomes linearly polarized light by the polarizing film (vertical) 47. When no voltage is applied to the liquid crystal 45, the light travels straight. Since the polarizing film (vertical) 47 and the polarizing film (horizontal) 43 are arranged so that their polarization directions intersect perpendicularly, the light cannot pass through the polarizing film (horizontal) 43, and the light is there. Blocked. On the other hand, when a voltage is applied to the liquid crystal 45, the arrangement of liquid crystal molecules changes. At that time, the polarized light entering the direction of the axis of the liquid crystal molecule changes along the direction of the axis of the liquid crystal molecule, and the polarization direction changes by 90 degrees. Therefore, the light that has been linearly polarized by the polarizing film (vertical) 47 can be transmitted through the polarizing film (horizontal) 43 by changing the polarization direction. Thus, the liquid crystal display 40 can display various characters and figures on the display surface by recognizing the cells that do not transmit light as black dots and the cells that transmit light as white dots.

  The light transmitted through the liquid crystal display 40 is recognized by the operator's vision, so that the operator can check the displayed characters and figures. In this embodiment, normally, the light is acquired from the outside. The incident light 51 is natural light such as room lighting or sunlight. In the cell to which the voltage is applied, the incident light 51 passes through the glass layer 42 and reaches the transflective film 41. The transflective film 41 transmits a part of the incident light 51 and reflects a part thereof. The light reflected from the transflective film 41 is emitted from the display surface. Part of the light reflected from the semi-transmissive reflective film 41 is recognized by the operator's vision, and the operator can check the displayed characters and figures.

Also, the light emitting device 30 can be used to obtain the light described above. Incident light 52 is emitted from the light emitting device 30. Similarly to the above, the transflective film 41 transmits a part of the incident light 52 and reflects a part thereof. The light transmitted through the semi-transmissive reflective film 41 is emitted from the display surface. Part of the light transmitted through the transflective film 41 is recognized by the operator's vision, and the operator can check the displayed characters and figures.

  Thus, the liquid crystal display 40 used in the present embodiment can use both external light and light emitted from the light emitting device 30 as its light source. Such a liquid crystal display is generally known as a transflective liquid crystal display.

  Subsequently, a method of using the blood glucose concentration measuring device 10 and a flow of control performed by the control unit 27 at that time will be described. The function of the blood glucose concentration measuring device 10 is roughly divided into a function for measuring the blood glucose concentration and a function for displaying the measured glucose concentration. The blood glucose concentration measuring device 10 also has a function of deleting unnecessary data in the storage unit 22, a function of adjusting the date and time of the clock unit 26, and the like, which are appropriately designed by those skilled in the art. Can do.

[Function for measuring blood glucose concentration]

  First, the function for measuring blood glucose concentration is explained. The measurement subject presses the operation button 13A of the main body 11 or sets the sensor 15 on the main body 11 to set the blood glucose concentration measuring apparatus 10 to the mode for measuring the blood glucose concentration. When measuring the blood glucose concentration, the blood of the measurement subject is collected. The blood can be collected by the person himself / herself using, for example, a lancet. The collected blood is introduced into the sensor 15 as a sample. Although not shown in detail in each drawing, an opening for introducing blood is formed in the sensor 15, and when blood is attached to the opening, blood is introduced into the sensor 15 by capillary action. . The introduced blood is held between the working electrode and the counter electrode to cause an electrochemical reaction as described above. By this electrochemical reaction, an electric current having an electric quantity corresponding to the blood glucose concentration is generated between the working electrode and the counter electrode of the sensor 15. This current corresponds to a signal indicating the glucose concentration in blood in the present invention.

  The current is converted into numerical data indicating the blood glucose concentration by amplifying the current flowing in the sensor 15 by the control unit 27 or performing AD conversion. The numerical data is stored in the storage unit 22. The AD conversion process is performed using a circuit of the control unit 27 and a program stored in the ROM of the control unit 27. Alternatively, the AD conversion process may be performed by a dedicated circuit included in the measurement unit 21 before the signal is passed to the control unit 11. Such measurement of the blood glucose concentration may be programmed to be automatically performed by introducing blood into the sensor 15.

  At the time of measurement, the control unit 27 acquires a date / time signal from the clock unit 26 and stores the date / time signal in the storage unit 22 in a state associated with the measured glucose concentration. A person skilled in the art can appropriately determine what data structure is used for this association.

[Function for displaying glucose concentration]

  Subsequently, the function for displaying the stored glucose concentration is explained. A doctor or a person to be measured (hereinafter referred to as an operator) presses the operation button 13A of the main body 11 to set the blood glucose concentration measuring apparatus 10 to a mode for displaying the glucose concentration. Then, the glucose concentration measured most recently and the measurement date and time are displayed on the display screen 12. The displayed glucose concentration and measurement date and time are switched to the past by pressing the operation button 13B. Further, when the operation button 13C is pressed, it is switched to the future one.

  In order to realize the above-described function, the control unit 27 performs the following control. The control unit 27 sequentially reads the measurement date and time stored in the storage unit 22 using an operation signal output by pressing the operation button 13A as a trigger. And the control part 27 produces | generates the linear list which arranged the measurement date / time memorize | stored in the memory | storage part 22 in descending order with the appropriate sort algorithm. The control unit 27 causes the display unit 23 to display the last measurement date and time of the linear list and the corresponding glucose concentration. When an operation signal is output by pressing the operation button 13B, the control unit 27 refers to the measurement date and time one upstream of the linear list, and causes the display unit 23 to display the measurement date and time and the corresponding glucose concentration. When an operation signal is output by pressing the operation button 13C, the control unit 27 refers to the measurement date and time one downstream of the linear list, and displays the measurement date and time and the glucose concentration corresponding thereto on the display unit 23. . Through the above flow, the measurement date and glucose concentration displayed on the display screen 12 are changed in time series.

  Alternatively, the measured glucose concentration can be automatically displayed after the measurement. At the time of measurement, the control unit 27 receives electrical signals from the measurement unit 21 and the clock unit 26 and causes the display unit 23 to display the glucose concentration and time obtained therefrom. A person skilled in the art can appropriately determine which display method is adopted. For example, when the blood glucose concentration measuring device does not include the storage unit 22, only the latter display method may be employed.

  When the control unit 27 displays each measurement date and time and glucose concentration on the display unit 23, the control unit 27 irradiates the backlight unit 24 with light. The control unit 27 stores a data table. The data table includes data that associates a threshold value corresponding to the glucose concentration with the color of light emitted from the backlight unit 24. FIG. 5 is a conceptual diagram showing data constituting the data table. As shown in the figure, the data constituting the data table includes the first threshold value, the second threshold value, the third threshold value, the first emission color, the second emission color, the third emission color, and the fourth emission color. The first threshold value, the second threshold value, and the third threshold value indicate blood glucose concentrations expressed in units of “mg / dl”, respectively. The first light emission color, the second light emission color, the third light emission color, and the fourth light emission color indicate the colors of light emitted by the backlight unit 24, respectively. In the figure, numerical values of 80, 120, and 160 are stored as the first threshold value, the second threshold value, and the third threshold value, respectively. In addition, character strings “blue”, “green”, “yellow”, and “red” are stored as the first emission color, the second emission color, the third emission color, and the fourth emission color, respectively.

  FIG. 6 is a flowchart showing a process performed by the control unit 27 when the glucose concentration is displayed. First, in step 1 (S1), the control unit 27 acquires data indicating the glucose concentration to be displayed and the measurement date and time from the storage unit 22. Alternatively, when the display is performed immediately after the measurement, those data may be directly acquired from the measurement unit 21 and the clock unit 26. In step 2 (S2), the control unit 27 stores the data (first threshold value, second threshold value, third threshold value and first emission color, second emission color, third emission color, and the like stored in the data table. 4 emission colors) is acquired from the flash memory provided in the control unit 27 itself.

  In step 3 (S3), the control unit 27 compares the glucose concentration with the first threshold value. When the glucose concentration is less than the first threshold value and the process branches to step 4 (S4), the control unit 27 causes the backlight unit 24 to emit light of a color corresponding to the first emission color. In step 5 (S5), the same comparison and branching are performed as in step 3 (S3). When the glucose concentration is less than the second threshold value and the process branches to step 6 (S6), the control unit 27 causes the backlight unit 24 to emit light of a color corresponding to the second emission color. The same applies to step 7 (S7). When the glucose concentration is equal to or higher than the third threshold value and the process branches to step 8 (S8), the control unit 27 causes the backlight unit 24 to emit light of a color corresponding to the third emission color. On the other hand, when branched to step 9 (S9), the control unit causes the backlight unit 24 to emit light of a color corresponding to the fourth emission color.

  As a result of the processing, the glucose concentration is (1) less than the first threshold, (2) more than the first threshold and less than the second threshold, (3) more than the second threshold and less than the third threshold, (4) more than the fourth threshold, In accordance with each of the above conditions, the backlight unit 24 emits light of colors corresponding to one emission color, second emission color, third emission color, and fourth emission color, respectively.

  Regardless of the route of step 4 (S4), step 6 (S6), step 8 (S8), or step 9 (S9), the process finally reaches step 10 (S10). The control unit 27 displays the measurement date and glucose concentration on the display unit 23. Almost at the same time when the operator performs an operation for displaying the glucose concentration, the display unit 23 emits light, and the glucose concentration and the measurement date and time are displayed on the display unit 23.

  FIG. 7 is a diagram showing an example of a screen on which the glucose concentration is displayed. In the measurement date display area 61 and the measurement time display area 62, the measurement date and time acquired in step 1 (S1) is displayed. Similarly, in the glucose concentration display area 63, the glucose concentration acquired in step 1 (S1) is displayed. The glucose concentration is displayed large in the center of the screen so that it can be confirmed even by elderly people and blindness. In the unit display area 64, “mg / dl” indicating the unit of glucose concentration is displayed. Since the liquid crystal display 40 constituting the display unit 23 is a monochrome liquid crystal display, all displayed characters or numerical values are displayed as black characters.

  Depending on the numerical value displayed in the glucose concentration display area 63, the background 65 emits light in any one of red, yellow, green, and blue. For example, the numerical value displayed in the glucose concentration display area 63 in the figure is 104. In the data table shown in FIG. 5, 104 is equal to or greater than the first threshold and less than the second threshold. Accordingly, the backlight unit 24 emits green light corresponding to the second emission color “green”. As a result, the background 65 emits green light by the irradiated light.

  In the present embodiment, the 1 emission color, the 2nd emission color, the 3rd emission color, and the 4th emission color have glucose concentrations of “lower”, “normal”, “slightly higher”, and “higher”, respectively. It is shown that. That is, that the background 65 emits green light means that the glucose concentration being displayed is normal. The user can intuitively determine whether the glucose concentration is at a normal value by checking the color of the background 65. What values are adopted as the first threshold value, the second value threshold value, and the third threshold value, and what colors are selected as the first emission color, the second emission color, the third emission color, and the fourth emission color. Whether it is adopted can be appropriately determined by those skilled in the art.

  The control unit 27 controls the backlight unit 24 to continue irradiation while displaying the glucose concentration on the display unit 23. The operator can end the display of the glucose concentration by pressing the operation button 13A. The control unit 27 uses the operation signal output when the operation button 13A is pressed as a trigger to end the display of the glucose concentration on the display unit 23. At the same time, the control unit 27 causes the backlight unit 24 to stop emitting light. That is, the display screen 12 emits light only while displaying the glucose concentration. Thereby, the battery consumption of the main body 11 is reduced.

  Further, the control unit 27 can also control the backlight unit 24 to continue irradiation only for a certain time. The control unit 27 causes the display unit 23 to start displaying the glucose concentration, and at the same time, starts counting time using a timer. The function of the clock unit 26 may be used as this timer. When 5 seconds elapse after the control unit 27 starts displaying the glucose concentration, the control unit 27 causes the backlight unit 24 to stop emitting light. Accordingly, the display screen 12 emits light for a certain time after the display of the glucose concentration is started. Thereby, the battery consumption of the main body 11 is further reduced. At this time, the display of the glucose concentration may be terminated simultaneously with the backlight unit 24 stopping the light irradiation. The time for which the display screen 12 continues to emit light can be appropriately determined by those skilled in the art. Moreover, the blood glucose concentration measuring apparatus 10 may be designed so that the operator can change the time during which the display screen 12 continues to emit light.

  In addition, the control unit 27 can cause the backlight unit 24 to start irradiating light with the operation signal output by pressing the operation button 13C as a trigger. The light irradiated at this time is white light. The control unit 27 starts counting the time using a timer at the same time that the backlight unit 24 starts irradiating light. When no operation signal is output from the operation unit 25 for 20 seconds from the start of the count, the control unit 27 stops the light irradiation of the backlight unit 24. That is, the operator can arbitrarily cause the display screen 12 to emit light by pressing the operation button 13C. Thereby, the operator can operate the blood glucose concentration measuring apparatus 10 even in an environment where it is difficult to obtain external light such as at night or in a dark room. Further, when the operator does not perform an operation for 20 seconds, the light is automatically turned off, so that the battery consumption is reduced. The time for which the display screen 12 continues to emit light can be appropriately determined by those skilled in the art. Moreover, the blood glucose concentration measuring apparatus 10 may be designed so that the operator can change the time during which the display screen 12 continues to emit light.

  In the present embodiment, the first threshold value, the second threshold value, and the third threshold value constituting the data table can be changed afterwards by the operator. The operator presses the operation button 13A of the main body 11 to place the blood glucose concentration measuring apparatus 10 in the setting mode. FIG. 8 is a diagram showing an example of the setting screen 70 displayed at that time. In the figure, numerical fields 71, 72 and 73 are used for setting a first threshold value, a second threshold value and a third threshold value, respectively. Here, 80, 120, and 160 are set as the first threshold value, the second threshold value, and the third threshold value, respectively. When the setting screen is displayed, the outer frame of the numerical value field 71 is blinking. This indicates that the first threshold is changeable. The operator raises or lowers the numerical value in the numerical value field 71 one by one by pressing the operation buttons 13B and 13C. At this time, the numerical value in the first threshold value display area 74 also changes in conjunction with the numerical value in the numerical value field 71. After setting the target value, the operator can press the operation button 13A to end the setting of the first threshold value and make the second threshold value changeable. The second threshold value can also be set in the same manner, and the numerical value in the second threshold value display area 75 changes in conjunction with the numerical value field 72. After setting the target value, the operator can press the operation button 13A to end the setting of the second threshold value and make the third threshold value changeable. The third threshold value can also be set in the same manner, and the numerical value in the third threshold value display area 76 changes in conjunction with the numerical value field 73. After setting the target value, the operator can complete all the settings and end the setting mode by pressing the operation button 13A. When the setting mode is terminated, the control unit 27 updates the first threshold value, the second threshold value, and the third threshold value based on the values set in the numerical fields 71, 72, and 73.

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Since the operator can change each threshold value afterwards, the doctor can set a normal glucose concentration range according to the health condition of the patient. Note that the range of thresholds that can be set by the above-described method can be determined as appropriate by those skilled in the art. In order to prevent a patient with incorrect operation from changing the threshold value, a password may be required to enter the setting mode.

[Operational effects of this embodiment]

  The display screen 12 emits light in one of blue, green, yellow, and red depending on the glucose concentration. The operator can intuitively determine the height of the glucose concentration based on the emission color of the display screen 12.

  The threshold value can be easily updated by performing an operation on the setting screen. Therefore, the doctor can set an optimal threshold according to the patient's health condition. In addition, since the password is required to change the threshold value, it is possible to prevent the threshold value from being changed by a patient whose operation is incorrect.

  The backlight unit 24 irradiates only while the display unit 23 displays the blood glucose concentration. This reduces battery consumption. Further, the display of the blood glucose concentration on the display unit 23 and the light irradiation by the backlight unit 24 are performed for a certain period of time, thereby further reducing the battery consumption.

  The backlight unit 24 can also perform irradiation by pressing the operation button 13C. Therefore, the operator can operate the blood glucose concentration measuring device 10 by causing the display screen 12 to emit light even at night or in a dark room.

  Since the LED element 36 is a full color LED, the blood glucose concentration measuring apparatus 10 can be easily downsized.

  Since a dry cell or a lithium battery is used as a power source of the blood glucose concentration measuring device 10, the manufacturing cost of the blood glucose concentration measuring device 10 is reduced.

  Since the liquid crystal display 40 is a monochrome liquid crystal display, the character readable property is high.

DESCRIPTION OF SYMBOLS 10 ... Blood glucose level measuring device 11 ... Main body 12 ... Display screen 13A ... Operation button 13B ... Operation button 13C ... Operation button 14 ... Sensor insertion port 15 ... Sensor 21 ... Measurement unit 22 ... Storage unit 23 ... Display unit 24 ... Backlight unit 25 ... Operation unit 26 ... Clock unit 27 ... Control unit 30 ... Light emitting device 31 ... LED light source 32 ... light guide plate 33 ... diffusing surface 34 ... reflecting surface 35 ... joining surface 36 ... LED element 40 ... liquid crystal display 41 ... semi-transmissive reflecting film 42 ... Glass layer 43 ... Polarizing film (horizontal)
44 ... light distribution film 45 ... liquid crystal 46 ... light distribution film 47 ... polarizing film (vertical)
48 ... Glass layer 51 ... Incident light 52 ... Incident light 61 ... Measurement date display area 62 ... Measurement time display area 63 ... Glucose concentration display area 64 ... Unit display area 65 ... Background 70 ... Setting screen 71 ... Numeric field 72 ... Numeric field 73 ... Numeric field 74 ... First threshold display area 75 ... Second threshold display area 76 ... Third threshold display area

Claims (7)

A measurement unit that generates a signal indicating the glucose concentration in the blood;
A monochrome liquid crystal display capable of transmitting at least part of the light irradiated on the back surface to the display surface; and a display unit for displaying the glucose concentration;
A backlight unit capable of irradiating light of a plurality of colors using an LED as a light source, and capable of irradiating any one of the light of the plurality of colors from the back side of the monochrome liquid crystal display toward the monochrome liquid crystal display;
A power supply for supplying power to at least the backlight unit;
Based on the value of the glucose concentration displayed on the display unit, one is determined from the color of light that can be irradiated by the backlight unit, and the backlight unit is irradiated with the light of the determined color, A portable blood glucose concentration measurement apparatus comprising: a control unit that displays a glucose concentration on the display unit.   The control unit stores a data table that associates a threshold value corresponding to a glucose concentration with a color of light that can be emitted by the backlight unit, and determines a color of light that is emitted to the backlight unit based on the data table. The portable blood glucose concentration measuring device according to claim 1 to be determined. An operation unit that receives an operation by the operator and outputs an operation signal corresponding to the operation;
The said control part updates the threshold value of the said data table to the threshold value which the said operation signal shows on condition that the operation signal which instruct | indicates the update of the said threshold value was output from the said operation part. Portable blood glucose concentration measurement device.   A time for displaying the glucose concentration on the display unit is set in advance in the control unit, and the backlight unit is irradiated with light only while the glucose concentration is displayed on the display unit. The portable blood glucose concentration measuring device according to any one of 1 to 3.   The portable blood glucose concentration measuring device according to any one of claims 1 to 4, wherein a light source of the backlight unit is a full color LED.   6. The portable blood glucose concentration measuring device according to claim 1, wherein the monochrome liquid crystal display is a transflective monochrome liquid crystal display.   The portable blood glucose concentration measuring device according to any one of claims 1 to 6, wherein the power source is a dry battery or a lithium battery.

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