Sensitivity calibration method for blood glucose measurement

Abstract

An embodiment may provide a sensitivity calibration method for blood glucose measurement, comprising: a step of calculating an offset value for determining sensitivity; a step of determining a first sensitivity from a sensing value and a reference blood glucose value on the basis of the offset value; and a step of adjusting the first sensitivity to determine the sensitivity; wherein the step of determining the sensitivity comprises the following steps: obtaining a sensitivity, reflecting an average sensing value obtained by averaging a plurality of sensing values and an average blood glucose value obtained by averaging a plurality of blood glucose values on the sensitivity, and adjusting the sensitivity to determine the sensitivity A; and a step of determining the sensitivity A as the sensitivity.

Description

Technical Field

[0001] The present embodiment relates to calibrating sensitivity for blood glucose measurement, and more particularly, to a technique for calibrating sensitivity including a plurality of steps for adjusting the sensitivity. Background Art

[0002] Recently, with the development of medical technology, various medical devices attached to the user's body have been developed and sold. The medical device attached to the user's body can be attached to the skin of a chronic disease patient and effectively used for monitoring biological information or treatment.

[0003] For example, chronic diseases such as diabetes require continuous management, and medical devices that attach to the skin to measure blood sugar can be used to monitor the blood sugar of diabetic patients. The characteristic of diabetes is that there are almost no subjective symptoms in the early stage, but as the disease progresses, diabetes-specific symptoms such as polydipsia, polyphagia, polyuria, weight loss, general fatigue, itchy skin, and long-term non-healing of wounds on hands and feet appear. As diabetes further develops, complications such as visual impairment, hypertension, kidney disease, stroke, periodontal disease, muscle spasms, neuralgia, gangrene, etc. will occur. In order to diagnose such diabetes and manage it to prevent it from progressing to complications, systematic blood sugar measurement and treatment must be carried out simultaneously.

[0004] Many medical device manufacturers are providing various types of blood glucose meters that can measure blood sugar for diabetic patients and for those who have not developed diabetes but have detected higher than normal levels of sugar in their blood.

[0005] Blood glucose meters are used in two methods: one in which the user collects blood from a fingertip and measures blood glucose once, and another in which the meter is attached to the user's abdomen or arm and measures blood glucose continuously.

[0006] Diabetic patients usually alternate between high and low blood sugar states, and emergencies come from low blood sugar states, which can lead to loss of life when the patient loses consciousness or continues to be in a low blood sugar state for a long time without sugar supply. Therefore, it is very important for diabetic patients to detect low blood sugar states immediately, but blood sampling blood glucose meters that measure blood sugar intermittently have limitations in accurately grasping this situation.

[0007] Recently, in order to overcome this limitation, a continuous glucose monitoring system (CGMS) has been developed and used, which is inserted into the human body and measures blood glucose levels every few minutes. In order to minimize the pain and resistance caused by blood sampling to the user, the continuous glucose monitoring system can continuously measure blood glucose after inserting a needle-shaped transdermal sensor into the abdomen and arms where the pain is relatively light.

[0008] The continuous blood glucose measurement system comprises a sensor transmitter and a terminal. The sensor transmitter is used to be inserted into the skin of a user to measure blood glucose in the body and transmit the measured blood glucose value. The terminal outputs the received blood glucose value.

[0009] Here, since the measurement of blood glucose is achieved in a state where the sensor transmitter is attached to the body and a part of the sensor is inserted into the human body, the sensor inserted into the human body may be identified as a foreign body. That is, a biological reaction to the sensor, such as a hydration reaction, may occur. Therefore, in the early stage of inserting the sensor, the sensitivity (sensitivity, slope) may change. As a result, the accuracy of the sensor may be reduced and it is difficult to maintain the service life. The changing slope may reduce the accuracy of the continuous blood glucose measurement system by calculating too much or too little blood glucose value for the measured biological signal. In the prior art, in order to compensate for this change in sensitivity (slope), a method of using a simple sensitivity and a preset offset value divided by a reference blood glucose value input by the user - a blood glucose value measured by a self blood glucose measurement system (blood glucose monitoring system, BGMS) - and a current value of the sensor, or a method of determining the sensitivity by regression analysis for a reference blood glucose value and a current value corresponding thereto, has been developed. However, this method may have the problem of providing inaccurate sensitivity and offset values ​​due to abnormal blood glucose values ​​or due to insensitive response to abnormal operation of the sensor. Summary of the invention

[0010] Technical issues to be solved

[0011] In this context, one object of the present embodiment is to provide a technique for calibrating sensitivity in order to calculate accurate sensitivity.

[0012] In this context, another object of the present embodiment is to provide a technology for providing calibrated sensitivity by adjusting the sensitivity in multiple steps in order to improve the accuracy of the sensitivity.

[0013] Solutions to the problem

[0014] In order to achieve the aforementioned purpose, one embodiment may provide a sensitivity calibration method for blood glucose measurement, comprising: a step of calculating an offset value for determining sensitivity; a step of determining a first sensitivity from a sensed value and a reference blood glucose value based on the offset value; and a step of adjusting the first sensitivity to determine the sensitivity; wherein the step of determining the sensitivity comprises: obtaining a sensitivity, and reflecting an average sensed value obtained by averaging multiple sensed values ​​and an average blood glucose value obtained by averaging multiple blood glucose values ​​in the sensitivity and adjusting the sensitivity to determine sensitivity A; and a step of determining the sensitivity A as the sensitivity.

[0015] Another embodiment may provide a sensitivity calibration method for blood glucose measurement, comprising: a step of calculating an offset value for determining sensitivity; a step of determining a first sensitivity from a sensing value and a reference blood glucose value based on the offset value; a step of adjusting the first sensitivity to determine sensitivity A by reflecting an average sensing value obtained by averaging a plurality of sensing values ​​within a given period and an average blood glucose value obtained by averaging a plurality of blood glucose values ​​within the given period in the first sensitivity; a step of determining a new sensitivity from the sensitivity A based on whether the blood glucose value calculated from the offset value and the sensitivity A falls within a given range; and a step of determining the new sensitivity as the sensitivity.

[0016] Effects of the Invention

[0017] As described above, according to this embodiment, accurate sensitivity can be calculated by calibrating the sensitivity.

[0018] Furthermore, according to the present embodiment, by adjusting the sensitivity in a plurality of steps, the accuracy of the sensitivity can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 FIG. 1 is a diagram for schematically illustrating a blood sugar measurement system according to an embodiment.

[0020] Figure 2 is a diagram for explaining an applicator for attaching a sensor transmitter to a human body according to an embodiment.

[0021] Figure 3 is a diagram for explaining a process of attaching a sensor transmitter to a human body using an applicator according to an embodiment.

[0022] Figure 4 is a diagram showing the structure of a sensor transmitter according to an embodiment.

[0023] Figure 5 is a diagram of a terminal structure according to an embodiment.

[0024] Figure 6is a flow chart illustrating a method of calibrating sensitivity according to an embodiment.

[0025] Figure 7 is an example diagram of adjusting sensitivity based on coded information of a sensor according to an embodiment.

[0026] Figure 8 is an example diagram of adjusting sensitivity based on a difference from a previously determined sensitivity according to an embodiment.

[0027] Figures 9 to 11 is an example diagram of adjusting sensitivity based on a specified range formed by a reference blood glucose value and a previous blood glucose value calculated from a previously determined sensitivity according to an embodiment.

[0028] Fig.12 is a flow chart illustrating a first method of calibrating sensitivity according to another embodiment.

[0029] Fig.13 It is shown based on Fig.12 Flow chart of a method for adjusting sensitivity based on average sensed values ​​and average blood glucose values.

[0030] Fig.14 It is shown based on Fig.13 Example graph of adjusting sensitivity based on average sensed values ​​and average blood glucose values.

[0031] Fig.15 is a flowchart illustrating one example of a first method of calibrating sensitivity according to another embodiment.

[0032] Fig.16 A flow chart illustrating a second method of calibrating sensitivity according to another embodiment. DETAILED DESCRIPTION

[0033] When describing the present invention, matters that are obvious to a person skilled in the art to which the present invention pertains will be omitted from detailed description when it is determined that the contents of well-known functions may unnecessarily obscure the gist of the present invention.

[0034] The terms used in this application are used only to illustrate specific embodiments and are not intended to limit the present invention. Unless otherwise clearly indicated in the context, singular expressions include plural expressions. It should be understood that in this application, terms such as "including" or "having" are only used to specify the existence of features, numbers, steps, actions, constituent elements, parts or combinations thereof recorded in the specification, and do not preclude the existence or additional possibility of one or more other features, numbers, steps, actions, constituent elements, parts or combinations thereof.

[0035] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. When describing with reference to the accompanying drawings, the same or corresponding components are given the same reference numerals and repeated description thereof will be omitted.

[0036] Figure 1 FIG. 1 is a diagram for schematically illustrating a blood sugar measurement system according to an embodiment.

[0037] Reference Figure 1 A blood glucose measurement system 10 (hereinafter, referred to as “system”) according to an embodiment may include a sensor transmitter 100 and a terminal 200 .

[0038] The sensor transmitter 100 is attached to the human body B. When the sensor transmitter 100 is attached to the human body B, one end of the sensor of the sensor transmitter 100 is inserted into the skin, so that the body fluid of the human body can be periodically extracted to measure blood sugar.

[0039] The terminal 200 can receive the biological signal including the blood sugar information from the sensor transmitter 100, and generate the blood sugar information from the biological signal and output it to the user. The terminal 200 can include various devices, such as a smart phone, a mobile phone, a tablet computer, a desktop, and a laptop, but is not limited thereto, and has a communication interface capable of communicating with the sensor transmitter 100, and can include a device capable of installing a program or application.

[0040] The sensor transmitter 100 may transmit the periodically measured biological signal to the terminal 200 according to the request of the terminal 200 or at each set time. In order to perform data communication between the sensor transmitter 100 and the terminal 200, the sensor transmitter 100 and the terminal 200 may be connected to each other by wire via a USB cable or the like, or may be connected wirelessly via infrared communication, NFC communication, Bluetooth, or the like.

[0041] Figure 2 is a diagram for explaining an applicator for attaching a sensor transmitter to a human body according to an embodiment, Figure 3 is a diagram for explaining a process of attaching a sensor transmitter to a human body using an applicator according to an embodiment.

[0042] Reference Figure 2 and Figure 3 According to an embodiment, the applicator 300 has the sensor transmitter 100 inside, and the sensor transmitter 100 is discharged to the outside by the user's operation so as to be attached to a specific body part of the user. The applicator 300 is formed in a shape with one side open, and the sensor transmitter 100 is set in the applicator 300 through the open side of the applicator 300.

[0043] When the applicator 300 is used to attach the sensor transmitter 100 to a part of the body, in order to insert one end of the sensor provided by the sensor transmitter 100 into the skin, the applicator 300 may include a needle (not shown) formed in a manner of surrounding one end of the sensor inside, a first elastic member (not shown) that pushes the needle and one end of the sensor together toward the skin, and a second elastic member (not shown) for withdrawing only the needle. With this structure of the applicator 300, the needle and one end of the sensor can be simultaneously inserted into the skin by releasing the compression of the first elastic member (not shown) configured inside the applicator 300 in a compressed state. When one end of the sensor is inserted into the skin, the compression of the compressed second elastic member (not shown) is released, and only the needle is withdrawn. The user can safely and easily attach the sensor transmitter 100 to the skin through the applicator 300.

[0044] Looking in detail at the process of attaching the applicator 300 to the human body B, the open side of the applicator 300 is attached to the specific part of the skin S of the human body B in a state where the protective cover (not shown) is separated. In this way, when the applicator 300 is operated in a state where the applicator 300 is attached to the skin S of the human body B, the sensor transmitter 100 can be attached to the skin S while being ejected from the applicator 300. Here, one end of the sensor 101 is exposed from the sensor transmitter 100 and arranged at the lower part of the sensor transmitter 100, and one end of the sensor 101 can be partially inserted into the skin S by a needle provided in the applicator 300. Therefore, the sensor transmitter 100 can be attached to the skin S in a state where one end of the sensor 101 is inserted into the skin S.

[0045] Here, the contact surface of the sensor transmitter 100 and the human body B may be provided with an adhesive tape so that the sensor transmitter 100 can be fixedly attached to the skin S of the human body B. Therefore, when the applicator 300 is spaced apart from the skin S of the human body B, the sensor transmitter 100 can be in a state of being fixedly attached to the skin S of the human body B by the adhesive tape.

[0046] Afterwards, when the sensor transmitter 100 is powered on, the sensor transmitter 100 communicates with the terminal, and the sensor transmitter 100 can transmit the biological signal including the blood sugar information to the terminal. The sensor transmitter 100 can generate not only the blood sugar information but also various biological information. Hereinafter, the measurement of the blood sugar information as an example of the biological information is described.

[0047] Figure 4 is a diagram showing the structure of a sensor transmitter according to an embodiment.

[0048] Reference Figure 4According to an embodiment, a sensor transmitter 100 may include a sensor module 110 , a sensor communication unit 120 , a sensor control unit 130 , and a sensor storage unit 140 .

[0049] The sensor module 110 may include at least one sensor inserted into a human body to sense biomass. The at least one sensor may measure the biomass and generate a biosignal. The biosignal may include a current value as an analog signal.

[0050] The sensor communication unit 120 may exchange data or information with the terminal. For example, the sensor communication unit 120 may transmit a biological signal received from the sensor module 110 or data stored in the sensor storage unit 140 to the terminal.

[0051] The sensor control unit 130 includes the sensor module 110, the sensor storage unit 140, and the sensor communication unit 120, so that the overall structure of the sensor transmitter 100 can be controlled. For example, the sensor control unit 130 can receive a control signal from the terminal and thereby control the structure of the sensor transmitter 100. In addition, the sensor control unit 130 can process the biological signal. For example, the sensor control unit 130 can convert the biological signal into an analog or digital form, or perform a process for removing noise as needed.

[0052] The sensor storage unit 140 may store data or information. For example, the sensor storage unit 140 may store data on biomass measured by the sensor module 110, such as a current value of a biosignal or data received from a terminal (such as an instruction value of a control signal).

[0053] Figure 5 is a diagram of a terminal structure according to an embodiment.

[0054] Reference Figure 5 According to an embodiment, the terminal 200 may include an output unit 210 , a communication unit 220 , a control unit 230 and a storage unit 240 .

[0055] The output unit 210 may output biological information included in the biological signal, such as blood sugar information, so that the user can confirm it. For example, the output unit 210 may display the blood sugar information as a numerical value or further display it as a graph processed by the numerical value.

[0056] The communication unit 220 can communicate with the sensor communication unit of the sensor transmitter and exchange data or information. For example, the communication unit 220 can receive a biological signal including information (biological information) about the biomass measured by the sensor transmitter. Here, the communication unit 220 can receive the biological signal after a processing from the sensor transmitter. Alternatively, the communication unit 220 can transmit a control signal for controlling the sensor transmitter to the sensor transmitter.

[0057] The storage unit 240 may store data or information. For example, the storage unit 240 may store data received from a sensor transmitter, such as biological information. Here, the biological information includes blood sugar information, which may be in the form of a current value. Alternatively, the storage unit 240 may store data input by a user or environment setting data for setting an operating environment of the terminal.

[0058] The control unit 230 may include at least one processor for executing a program for calibrating sensitivity for blood glucose measurement and at least one memory storing the program. The memory and processor included in the control unit 230 may be integrated into one chip or may be physically separated.

[0059] In order to store various programs, data and / or information, the memory can be implemented as a non-volatile memory device such as ROM (read only memory), PROM (programmable ROM), EPROM (erasable programmable ROM), EEPROM (electrically erasable programmable ROM) and flash memory, or a volatile memory device such as RAM (random access memory).

[0060] On the other hand, the control unit 230 can generate a blood glucose value as digitized blood glucose information from the biological information. To this end, the control unit 230 can obtain the biological information in the form of a current value from the sensor transmitter and pre-process and / or process the current value of the biological information. The control unit 230 can first calculate the sensitivity and generate the blood glucose value based on the sensitivity.

[0061] The control unit 230 can determine the sensitivity based on the current value and the reference blood glucose value input from the outside, and the sensitivity can be determined according to the following mathematical formula 1. Here, C refers to the current value at the time point when the sensitivity is determined based on the reference blood glucose value, that is, the current value at the time point of calibrating the sensitivity, and BGr is the reference blood glucose value, which is a blood glucose value obtained by a self blood glucose monitoring system (BGMS) and does not necessarily have to be obtained at the time point of calibrating the sensitivity.

[0062]

Mathematical formula 1

[0063]

[0064] After the sensitivity is obtained as shown above, the control unit 230 can multiply the current value by the sensitivity to generate a blood glucose value corresponding to the current value. The control unit 230 can provide the new blood glucose value to the user through the output unit 210. For example, the control unit 230 calculates the sensitivity as shown in Mathematical Formula 1 using the first current value obtained at the first time point and a reference blood glucose value, and can use the sensitivity to calculate a new blood glucose value until the time point (second time point) when the next sensitivity calibration is performed. In addition, the control unit 230 can calibrate the sensitivity again at the second time point. The control unit 230 can calculate the sensitivity as shown in Mathematical Formula 1 using the second current value obtained at the second time point and another reference blood glucose value, and recalculate the blood glucose value corresponding thereto.

[0065] On the other hand, this sensitivity may change due to various environmental variables. For example, changes in current value caused by hydration when the sensor is inserted into the body, or a negative intercept phenomenon in which the current value continues to decrease, may become factors that change the sensitivity. When the sensor transmitter sends a current value that is smaller than the original value to the terminal 200 due to the negative intercept phenomenon, the control unit 230 of the terminal 200 can calculate the sensitivity from the current value that is smaller than the original value according to mathematical formula 1. The sensitivity calculated in this way may be very large. When the control unit 230 calculates the blood sugar value with too high a sensitivity, the blood sugar value will become high even at a small current value, and the control unit 230 may generate an inaccurate blood sugar value.

[0066] To correct the error, the control unit 230 may calculate an offset value and reflect the offset value in the sensitivity calculation. The control unit 230 may calculate the offset value in various ways without limitation, and the offset value may be fixed or variable. The control unit 230 may determine the sensitivity reflecting the offset value according to the following mathematical formula 2. Here, Voff, as the offset value, may be a value preset by the user or a variable value according to the algorithm of the storage unit 250.

[0067]

Mathematical formula 2

[0068]

[0069] In the above example, the decrease in current value caused by the negative intercept phenomenon is offset by the offset value, and the smaller denominator becomes larger, so that the sensitivity can be changed to an appropriate level that is not excessive. However, according to an embodiment, the control unit 230 of the terminal 200 does not immediately apply the sensitivity reflecting the offset value to the blood glucose level calculation, but can adjust the sensitivity and finally apply the adjusted sensitivity to the blood glucose level calculation. The following is a method for calibrating the sensitivity by the control unit 230 of the terminal 200 through multiple steps of adjusting the sensitivity.

[0070] Figure 6is a flow chart showing a method for calibrating sensitivity according to an embodiment, Figure 7 is an example diagram of adjusting sensitivity based on coded information of a sensor according to an embodiment, Figure 8 is an example diagram of adjusting sensitivity based on a difference from a previously determined sensitivity according to an embodiment, Figures 9 to 11 is an example diagram of adjusting sensitivity based on a specified range formed by a reference blood glucose value and a previous blood glucose value calculated from a previously determined sensitivity according to an embodiment.

[0071] Reference Figure 6 , a method for calibrating sensitivity at a terminal constituting a blood glucose measurement system according to an embodiment can be shown. Although the following describes that sensitivity calibration is performed at the terminal, it is not limited thereto, and according to the configuration, it can also be performed at a sensor transmitter or a host connected to the terminal via a wired or wireless network, such as a server. The control unit of the terminal can first determine the sensitivity required to generate a blood glucose value from the current value, and apply the current value to the finally determined sensitivity to generate the blood glucose value.

[0072] To this end, the control unit of the terminal may first calculate an offset value for determining sensitivity (step S601). The offset value may be a value that compensates for a change in sensitivity caused by a decrease in a current value.

[0073] Furthermore, the control unit may determine the sensitivity according to Mathematical Formula 2 from the current value reflecting the offset value and the reference blood glucose value (step S603). The sensitivity determined here is not the final sensitivity, but may be the sensitivity that simply reflects the offset value before the adjustment step. Hereinafter, for ease of explanation, the sensitivity is named "first sensitivity". In addition, the current value is a type of value measured by the sensor included in the sensor module, and may also be named a sensing value.

[0074] First, the first sensitivity can be adjusted. The control unit of the terminal can determine the second sensitivity from the first sensitivity and the sensitivity preset according to the sensor (step S605). The sensitivity preset according to the sensor can be a sensitivity preset for a certain sensor, or can be a sensitivity preset for a certain group (lot) as a collection of multiple sensors. The sensitivity for a group of sensors can be understood as a specific sensitivity representing a group as a whole rather than representing the sensitivity of a single sensor. In the following, for ease of explanation, the sensitivity preset according to the sensor can be named "sensor sensitivity".

[0075] Here, the sensor sensitivity may include the ideal sensitivity expected by a sensor or a group of sensors under ideal conditions. For example, the sensor sensitivity may be understood as the sensitivity that a sensor or a group of sensors should have under ideal conditions such as a laboratory environment. Alternatively, the sensor sensitivity may be understood as the sensitivity preset in the factory when a sensor or a group of sensors is manufactured. The terminal needs to be encoded for initialization when in use, and during the encoding process, the sensor sensitivity may be included in the encoding information and input and / or stored in the terminal.

[0076] Reference Figure 7 , an example of determining the second sensitivity from the first sensitivity and the sensor sensitivity can be shown. The control unit of the terminal reflects the sensor sensitivity in order to adjust the first sensitivity, and as a result, the second sensitivity can be determined. However, the control unit of the terminal may reflect the sensor sensitivity differently according to certain circumstances.

[0077] First, the control unit may compare the first sensitivity and the sensor sensitivity. When the first sensitivity is greater than the sensor sensitivity, the control unit may determine the sensor sensitivity as the second sensitivity. For example, in this figure, when the first sensitivity S1 at the first calibration time point P1 is 25 and the sensor sensitivity Ss as the sensitivity based on the coded information is 20, the control unit may determine the second sensitivity S2 as 20. Hereinafter, for ease of explanation, the unit will be omitted. The control unit may trust the sensor sensitivity Ss more and determine the sensor sensitivity Ss as the second sensitivity S2.

[0078] Otherwise, that is, when the first sensitivity is less than the sensor sensitivity, the control unit may process the sensor sensitivity and determine the processed second sensitivity as the first sensitivity. For example, in this figure, when the first sensitivity S1 at the second calibration time point P2 is 5 and the sensor sensitivity Ss as the sensitivity based on the coded information is 20, the control unit may process the sensor sensitivity Ss and calculate a value equivalent to 1 / 3 of the sensor sensitivity Ss, and determine the value 20 / 3 (≈6.7) equivalent to 1 / 3 of the sensor sensitivity Ss as the second sensitivity S2. The control unit may trust the sensor sensitivity Ss more and determine the value of the processed sensor sensitivity Ss as the second sensitivity S2.

[0079] If the first sensitivity is the same as the sensor sensitivity, the control portion may determine the first sensitivity as it is as the second sensitivity.

[0080] Return again Figure 6, an adjustment can be made for the second sensitivity. The control unit of the terminal can adjust the second sensitivity and determine the third sensitivity based on the credibility of the first sensitivity based on the difference between the first sensitivity and the previously determined sensitivity (step S607). Here, the previously determined sensitivity refers to the final sensitivity at a previous time point, and the previous time point may refer to a specific time point in the past before the current time point of the sensitivity to be calibrated. The control unit of the terminal may also calculate the blood glucose value based on the previously determined sensitivity at the previous time point. In the following, for ease of explanation, it may be named "previous sensitivity".

[0081] Specifically, when the first sensitivity is continuously (at least twice) higher or lower than the previous sensitivity, the control unit of the terminal can trust the first sensitivity and determine that the credibility of the first sensitivity is high. Then, the control unit can calculate the combined sensitivity reflecting the first sensitivity and the second sensitivity, and determine the combined sensitivity as the third sensitivity. The control unit can calculate the combined sensitivity by averaging the first sensitivity and the second sensitivity.

[0082] Reference Figure 8 , an example of adjusting the second sensitivity to determine the third sensitivity can be shown. For example, in this figure, when the first sensitivity S1 at the first calibration time point P1 is 30 and the previous sensitivity Sp is 25, and the first sensitivity S1 at the second calibration time point P2 is 32 and the previous sensitivity Sp is 27, since the first sensitivity S1 has a higher value than the previous sensitivity Sp twice in a row at the calibration time point, the control unit determines that the credibility of the first sensitivity S1 having 29 at the third calibration time point P3 is high. Then, at the third calibration time point P3, the control unit can calculate the combined sensitivity from 29 of the first sensitivity S1 and 25 of the second sensitivity S2. The control unit can calculate the average value of 27 (= (29 + 25) / 2) of 29 of the first sensitivity S1 and 25 of the second sensitivity S2 as the combined sensitivity. The control unit can determine the combined sensitivity 27 as the third sensitivity S3.

[0083] As described above, when the first sensitivity is continuously high or low, it can be considered that the first sensitivity is appropriate, and unlike step S605, it is preferred that the first sensitivity is reflected more than the second sensitivity.

[0084] Return again Figure 6, the third sensitivity can be adjusted. The control unit of the terminal can calculate the blood glucose value from the offset value and the third sensitivity, and determine the fourth sensitivity from the third sensitivity according to whether the calculated blood glucose value is within the prescribed range. When the calculated blood glucose value is within the prescribed range, the control unit can consider the third sensitivity to be appropriate and determine the third sensitivity as the fourth sensitivity. Otherwise, the control unit can consider the third sensitivity to be inappropriate, thereby calculating the adjustment sensitivity instead of the third sensitivity, and determining the adjustment sensitivity as the fourth sensitivity.

[0085] Here, the prescribed range may be specified by a previous blood glucose value and a reference blood glucose value. The control unit may calculate the previous blood glucose value from the current value at the current time point, the previous sensitivity, and the previously calculated offset value (previous offset value). Furthermore, the control unit may obtain a reference blood glucose value from the outside (the reference blood glucose value used in determining the first sensitivity in step S601). The control unit may determine whether the blood glucose value calculated by the current value at the current time point, the offset value at the current time point, and the third sensitivity is within the region defined by the previous blood glucose value and the reference blood glucose value.

[0086] Reference Fig. 9 , an example of determining the fourth sensitivity from the third sensitivity according to whether the blood sugar value calculated by the third sensitivity is within a prescribed range can be shown. In one example, it can be assumed that the control unit determines the fourth sensitivity at the first calibration time point P1. First, the control unit can specify the prescribed range and determine the validity of the third sensitivity.

[0087] When the current value C at the first calibration time point P1 is 7, the previous sensitivity Sp is 20, and the previous offset value Voff_p is 0, the previous blood glucose value BGp may be 140 (= (7-0) 20). Here, the previous sensitivity Sp and the previous offset value Voff_p may be the sensitivity and offset value determined before the sensitivity calibration is performed at the first calibration time point P1. When the reference blood glucose value BGr at the first calibration time point P1 is 200, the blood glucose value region for making the blood glucose value by the third sensitivity effective, i.e., the prescribed range specified by the previous blood glucose value and the reference blood glucose value may correspond to 140 to 200.

[0088] Furthermore, since the current value C at the first calibration time point P1 is 7, the offset value Voff at the first calibration time point P1 is 0, and the third sensitivity S3 is 30, the control unit can calculate the blood sugar level BG as 210 (= (7-0) × 30) from them. Since the blood sugar level BG is 210, which is outside the prescribed range of 140 to 200, the control unit can consider that the third sensitivity S3 is invalid and calculate the adjustment sensitivity to determine the fourth sensitivity.

[0089] The control unit can calculate the adjustment sensitivity using the current value (at the current time point), the offset value (at the current time point), the previous blood sugar value, and the reference blood sugar value using the following Math 3.

[0090]

Mathematical formula 3

[0091]

[0092] According to this example, the current value C at the first calibration time point P1 is 7, the offset value Voff at the first calibration time point P1 is 0, the previous blood glucose value BGp is ​​140, and the reference blood glucose value BGr is 200, so the adjustment sensitivity Sa may be 24.29. The control unit may determine the adjustment sensitivity Sa as the fourth sensitivity. The control unit may determine 24.29 as the fourth sensitivity.

[0093] Reference Fig.10 , another example of determining the fourth sensitivity from the third sensitivity according to whether the blood sugar value calculated by the third sensitivity is within the prescribed range can be shown. In another example, it can be assumed that the control unit determines the fourth sensitivity at the second calibration time point P2. First, the control unit can specify the prescribed range and determine the validity of the third sensitivity.

[0094] When the current value C at the second calibration time point P2 is 5, the previous sensitivity Sp is 30, and the previous offset value Voff_p is 1, the previous blood glucose value BGp may be 120 (= (5-1) 30). Here, the previous sensitivity Sp and the previous offset value Voff_p may be the sensitivity and offset value determined before the sensitivity calibration is performed at the second calibration time point P2. When the reference blood glucose value BGr at the second calibration time point P2 is 140, the blood glucose value region for making the blood glucose value by the third sensitivity effective, i.e., the prescribed range specified by the previous blood glucose value and the reference blood glucose value may be equivalent to 120 to 140.

[0095] Furthermore, since the current value C at the second calibration time point P2 is 5, the offset value Voff at the second calibration time point P2 is 0.5, and the third sensitivity S3 is 28, the control unit can calculate the blood sugar value BG as 126 (= (5-0.5) × 28) from them. Since the blood sugar value BG is 126, which is within the prescribed range of 120 to 140, the control unit can consider the third sensitivity S3 to be valid and determine it as the fourth sensitivity. Therefore, in this example, the fourth sensitivity can be 28.

[0096] Reference Fig.11 , another example of determining the fourth sensitivity from the third sensitivity according to whether the blood sugar value calculated by the third sensitivity is within the prescribed range can be shown. In another example, it can be assumed that the control unit determines the fourth sensitivity at the third calibration time point P3. First, the control unit can specify the prescribed range and determine the validity of the third sensitivity.

[0097] When the current value C at the third calibration time point P3 is 12, the previous sensitivity Sp is 25, and the previous offset value Voff_p is 0.5, the previous blood glucose value BGp may be 287.5 (= (12-0.5) × 25). Here, the previous sensitivity Sp and the previous offset value Voff_p may be the sensitivity and offset value determined before the sensitivity calibration is performed at the third calibration time point P3. When the reference blood glucose value BGr at the third calibration time point P3 is 200, the blood glucose value region for making the blood glucose value by the third sensitivity effective, i.e., the prescribed range specified by the previous blood glucose value and the reference blood glucose value, may correspond to 200 to 287.5.

[0098] Furthermore, the current value C at the third calibration time point P3 is 12, the offset value Voff at the third calibration time point P3 is 0.3, and the third sensitivity S3 is 15, so the control unit can calculate the blood sugar level BG as 175.5 (= (12-0.3) × 15) from them. Since the blood sugar level BG is 175.5, which is outside the prescribed range of 200 to 287.5, the control unit can consider that the third sensitivity S3 is invalid and calculate the adjustment sensitivity to determine the fourth sensitivity.

[0099] The control unit can calculate the adjustment sensitivity from the current value (at the current time point), the offset value (at the current time point), the previous blood glucose value, and the reference blood glucose value through the above-mentioned mathematical formula 3. According to this example, the current value C at the third calibration time point P3 is 12, the offset value Voff at the third calibration time point P3 is 0.3, the previous blood glucose value BGp is ​​287.5, and the reference blood glucose value BGr is 200, so the adjustment sensitivity Sa may be 20.33. The control unit may determine 20.33 as the fourth sensitivity.

[0100] Fig.12 FIG. 4 is a flow chart illustrating a first method for calibrating sensitivity according to another embodiment.

[0101] Reference Fig.12 , a first method for calibrating sensitivity in a terminal constituting a blood glucose measurement system according to another embodiment may be shown. The following is not limited to this, and depending on the configuration, it may also be executed in a host (e.g., a server) connected to a sensor transmitter or a terminal via a wired / wireless network. The control unit of the terminal may first determine the sensitivity required to generate a blood glucose value from a current value, and apply the current value to the finally determined sensitivity to generate a blood glucose value. In addition, another embodiment includes the same configuration as an embodiment and directly applies the description of an embodiment. The following description common to an embodiment is omitted, and the description will be centered on the differences.

[0102] First, the control unit of the terminal may calculate an offset value for determining sensitivity (step S1201). The offset value may be a value for compensating for a change in sensitivity caused by a decrease in the current value.

[0103] Furthermore, the control unit may determine the sensitivity (step S1203) from the current value reflecting the offset value and the reference blood glucose value according to Mathematical Formula 2. The determined sensitivity is the "first sensitivity" rather than the final sensitivity, and may be the sensitivity that simply reflects the offset value before the adjustment step.

[0104] Then, the first sensitivity may be adjusted. The control unit of the terminal may finally determine the sensitivity by adjusting the first sensitivity (step S1205). In order to finally determine the sensitivity from the first sensitivity, the control unit of the terminal may perform the following detailed adjustments.

[0105] Specifically, the control unit of the terminal can adjust the first sensitivity based on the average sensing value obtained by averaging multiple sensing values ​​and the average blood glucose value obtained by averaging multiple blood glucose values ​​(step S1205-1). Wherein, when the first sensitivity is adjusted based on the average sensing value obtained by averaging multiple sensing values ​​and the average blood glucose value obtained by averaging multiple blood glucose values, the adjusted first sensitivity can be named "sensitivity A".

[0106] The control unit of the terminal may determine the sensitivity A as the adjusted first sensitivity, that is, as the final sensitivity required by the control unit of the terminal (step S1205-2). The step of determining the sensitivity A is specifically examined below.

[0107] Fig.13 It is shown based on Fig.12 A flowchart of a method for adjusting sensitivity based on average sensing values ​​and average blood glucose values, Fig.14 It is shown based on Fig.13 Example graph of adjusting sensitivity based on average sensed values ​​and average blood glucose values.

[0108] Reference Fig.13 , a method of adjusting sensitivity based on an average sensed value and an average blood glucose value according to another embodiment, that is, a method of determining sensitivity A may be illustrated.

[0109] The control unit of the terminal can generate a first sensitivity by mathematical formula 2 (step S1301). Moreover, the control unit of the terminal can obtain an average sensing value and an average blood glucose value (step S1303). The average sensing value may mean a value obtained by averaging the sensing values ​​measured by the sensor until the current time point of calibrating the sensitivity. The starting time point of the average may be the time point of inserting the sensor or any time point before the current time point preset by the user. The sensing values ​​can be averaged from this time point to the current time point. In addition, the average blood glucose value may mean a value obtained by averaging the blood glucose values ​​calculated by the blood glucose measurement system until the current time point of calibrating the sensitivity. Like the average sensing value, after the starting time point of the average is determined, the blood glucose value can be averaged from this time point to the current time point.

[0110] Then, the control unit of the terminal may apply the first weighted value to the first sensitivity, the average sensing value, and the average blood glucose value to calculate the average sensitivity (step S1305). The first weighted value may be assigned to each of the first sensitivity, the average sensing value, and the average blood glucose value, and each first weighted value may change according to time. For example, the control unit of the terminal may apply the 1ath weighted value to the first sensitivity, the 1bth weighted value to the average sensing value, and the 1cth weighted value to the average blood glucose value. As the 1bth and 1cth weighted values ​​are adjusted, the proportion reflected in the first sensitivity may increase or decrease.

[0111] Furthermore, the control unit of the terminal may calculate the difference between the first sensitivity and the average sensitivity, and determine whether the difference exceeds a predetermined range (step S1307). If the difference exceeds a predetermined range, the control unit of the terminal may use the average sensitivity instead of the first sensitivity, and determine the sensitivity A from the average sensitivity (yes in step S1307 and step S1309). If the first sensitivity deviates excessively from the average sensitivity, the average sensitivity is used. The control unit of the terminal may apply a second weighted value to the average sensitivity and determine it as sensitivity A. Sensitivity A is determined as the final sensitivity, and the control unit of the terminal may calculate the blood sugar level from the current value through sensitivity A (step S1311).

[0112] If the difference does not exceed the predetermined range, the control unit of the terminal may not use the average sensitivity, but may determine the first sensitivity as sensitivity A (NO in step S1307 and step S1313). Sensitivity A is determined as the final sensitivity, and the control unit of the terminal may calculate the blood sugar level from the current value using sensitivity A (step S1315).

[0113] Reference Fig.16 , another example of adjusting the sensitivity based on the average sensing value and the average blood glucose value according to another embodiment can be shown. In this figure, the current value corresponding to the sensing value, the average current value corresponding to the average sensing value, and the average blood glucose value can be shown together.

[0114] The first calibration time point P1, as the current time point, may be the time point at which the control unit of the terminal calculates the final sensitivity in order to calculate the blood glucose value. At the first calibration time point P1, the control unit of the terminal may obtain the first sensitivity S1 as 20. Furthermore, the control unit of the terminal may apply the first weighted value to the average sensing value, the average blood glucose value, and the first sensitivity S1 and calculate the average sensitivity Savg as 30.

[0115] Moreover, the control unit of the terminal may determine the sensitivity A based on the average sensitivity Savg. Specifically, the control unit of the terminal may calculate the difference Diff between the first sensitivity S1 and the average sensitivity Savg. The difference Diff may be represented by the ratio of the difference between the first sensitivity S1 and the average sensitivity Savg relative to the average sensitivity Savg. If the above numerical value is applied, the difference Diff may be 33.3%. It may be judged that the difference Diff exceeds a predetermined range (for example, the predetermined range is 20%). The predetermined range may be the same concept as the preset threshold. Therefore, the average sensitivity Savg may be used to determine the sensitivity A, and a second weighted value may be applied to the average sensitivity Savg. The second weighted value may be set to 0.85, and the sensitivity A may be 25.5. Among them, the second weighted value may change in a manner that increases over time. As a result, the ratio reflected by the average sensitivity Savg for sensitivity A will increase. This is because the longer the time, the more accurate the average sensitivity Savg that reflects the past trend will be.

[0116] Fig.15 is a flowchart illustrating one example of a first method of calibrating sensitivity according to another embodiment.

[0117] Reference Fig.15 The first method of calibrating sensitivity of another embodiment may include at least a part of the sensitivity calibration step described in one embodiment. The first method may include an example of a step of calibrating sensitivity according to whether the blood glucose value calculated by the offset value and a sensitivity falls within a predetermined range.

[0118] An offset value for determining sensitivity may be calculated (step S1501). The offset value may be a value for compensating for a change in sensitivity caused by a decrease in the current value.

[0119] Furthermore, the control unit may determine the first sensitivity based on the current value reflecting the offset value and the reference blood sugar level according to Mathematical Formula 2 (step S1503).

[0120] Then, the first sensitivity may be adjusted. The control unit of the terminal may finally determine the sensitivity by adjusting the first sensitivity (step S1505). In order to finally determine the sensitivity from the first sensitivity, the control unit of the terminal may adjust the first sensitivity in detail as follows.

[0121] The control unit of the terminal may adjust the first sensitivity based on an average sensing value obtained by averaging a plurality of sensing values ​​and an average blood sugar value obtained by averaging a plurality of blood sugar values ​​to determine the sensitivity A (step S1505 - 1 ).

[0122] Furthermore, the control unit of the terminal may determine the fourth sensitivity from the sensitivity A according to whether the blood sugar level calculated from the offset value and the sensitivity A is within a predetermined range (step S1505-2). The determination of the fourth sensitivity may be the same as described in one embodiment.

[0123] The control unit of the terminal may determine any one of the sensitivity A and the fourth sensitivity as the first sensitivity after adjustment, that is, as the final sensitivity required by the control unit of the terminal (step S1505-3). In step S1505-1, the control unit of the terminal may calculate the sensitivity A, and in step S1505-2, the fourth sensitivity may also be determined based on the sensitivity A. The control unit of the terminal may determine any one of the sensitivity A and the fourth sensitivity as the final sensitivity for calculating the blood sugar value from the current value. The control unit of the terminal may adjust the first sensitivity to determine the sensitivity through steps S1505-1 to S1505-3.

[0124] Fig.16 is a flow chart illustrating a second method of calibrating sensitivity according to another embodiment.

[0125] Reference Fig.16 , a second method of calibrating sensitivity in a terminal constituting a blood glucose measurement system according to another embodiment may be shown. In the first method, the steps of determining the sensitivity A and the second to fourth sensitivities are selectively applied or applied in parallel, whereas in the second method, the steps may be applied serially in a manner having a sequence.

[0126] Specifically, an offset value for determining sensitivity may be calculated (step S1601). The offset value may be a value that compensates for a change in sensitivity caused by a decrease in the current value.

[0127] Furthermore, the control unit may determine the first sensitivity based on the current value reflecting the offset value and the reference blood sugar value according to Mathematical Formula 2 (step S1603).

[0128] In addition, the control unit of the terminal may obtain a first sensitivity and adjust the first sensitivity to determine a sensitivity A based on an average sensing value obtained by averaging a plurality of sensing values ​​and an average blood sugar value obtained by averaging a plurality of blood sugar values ​​(step S1605).

[0129] In addition, the control unit of the terminal may obtain the sensitivity A, and determine the fourth sensitivity from the sensitivity A according to whether the blood sugar level calculated from the offset value and the sensitivity A is within a predetermined range (step S1607).

[0130] Furthermore, the control unit of the terminal may determine the fourth sensitivity as the final sensitivity (step S1609).

[0131] Various aspects of the subject matter described in this specification may be described in the context of computer-executable instructions such as program modules executed on a computer. Typically, program modules include routines, programs, objects, components, data structures, etc., which perform specific tasks or specific abstract data types.

[0132] Alternatively or additionally, at least part of the functions described in this specification may be performed by one or more hardware logic components. As examples and not limitations, example types of hardware logic components that may be used include field programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), system-on-a-chip systems (SOCs), complex programmable logic devices (CPLDs), and the like.

[0133] On the other hand, the disclosed embodiments may be implemented in the form of a recording medium storing computer executable programs and / or instructions. The instructions may be stored in the form of program codes, and when executed by a processor, a program module may be generated to perform the operations of the disclosed embodiments. The recording medium may be implemented as a computer readable recording medium.

[0134] Computer-readable recording media include all types of recording media that store instructions that can be interpreted by a computer, such as ROM (read only memory), RAM (random access memory), magnetic tape, magnetic disk, flash memory, optical data storage, etc.

[0135] An embodiment of the present invention has been described above. However, a person skilled in the art can modify and change the present invention in various ways by adding, changing or deleting constituent elements without departing from the scope of the present invention as described in the claims. It can be said that this is also included in the scope of rights of the present invention.

Claims

1. A sensitivity calibration method for blood glucose measurement, comprising: The step of calculating an offset value for determining sensitivity; Based on the offset value, a step of determining a first sensitivity from the sensed value and a reference blood glucose value; and adjusting said first sensitivity to determine a sensitivity step; Wherein, the step of determining the sensitivity comprises: A step of obtaining a sensitivity, and reflecting an average sensing value obtained by averaging a plurality of sensing values ​​and an average blood glucose value obtained by averaging a plurality of blood glucose values ​​on the sensitivity to adjust the sensitivity to determine a sensitivity A; and The step of determining the sensitivity A as the sensitivity.

2. The sensitivity calibration method for blood glucose measurement according to claim 1, wherein: The step of determining the sensitivity A comprises: The step of calculating a result obtained by applying a first weighting value to the average sensing value, the average blood glucose value and the sensitivity as an average sensitivity; and The step of determining the sensitivity A based on the average sensitivity.

3. The sensitivity calibration method for blood glucose measurement according to claim 2, wherein: The step of determining the sensitivity A based on the average sensitivity is, If the difference between the one sensitivity and the average sensitivity exceeds a predetermined range, the sensitivity A is determined as the result of applying a second weighting value to the average sensitivity.

4. The sensitivity calibration method for blood glucose measurement according to claim 3, wherein: The second weighting value increases with time, thereby increasing the reflection ratio of the average sensitivity to the sensitivity A.

5. The sensitivity calibration method for blood glucose measurement according to claim 1, wherein: The step of determining the sensitivity further comprises: A step of obtaining another sensitivity and determining a new sensitivity from the another sensitivity according to whether the blood glucose value calculated from the offset value and the another sensitivity falls within a predetermined range; The step of determining the sensitivity A as the sensitivity is, Any one of the sensitivity A and the new sensitivity is determined as the sensitivity.

6. A sensitivity calibration method for blood glucose measurement, comprising: The step of calculating an offset value for determining sensitivity; Based on the offset value, a step of determining a first sensitivity from the sensed value and a reference blood glucose value; A step of reflecting an average sensing value obtained by averaging a plurality of sensing values ​​within a predetermined period and an average blood glucose value obtained by averaging a plurality of blood glucose values ​​within the predetermined period on the first sensitivity and adjusting the first sensitivity to determine sensitivity A; A step of determining a new sensitivity from the sensitivity A according to whether the blood sugar level calculated from the offset value and the sensitivity A falls within a predetermined range; and The step of determining the new sensitivity as the sensitivity.

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