Method for correcting biological value according to stability of biological value in biological information measurement system

Abstract

The present invention relates to a method for correcting a biological value of a user in a biological information measurement system, and more particularly, to a method for correcting a biological value, which determines whether the biological value is stable from the difference between a blood biological value and a body fluid biological value when a correction factor is calculated using a reference biological value, and which corrects the biological value when the biological value is unstable. This makes it possible to accurately determine a corrected biological value of a user from a biological value measured by a sensor by using a correction factor obtained by weighting the correction factor instead of using the correction factor calculated from a reference biological value as it is.

Description

Technical Field

[0001] The present invention relates to a method for correcting a user's biological value in a biometric information measurement system, and more specifically, to a method for correcting a biological value as follows, namely, when calculating a correction factor using a baseline biological value, whether the biological value is stable is judged by the difference between the blood biological value and the body fluid biological value. When the biological value is unstable, the correction factor calculated using the baseline biological value is not used as is, but a modified correction factor that gives a weight to the correction factor is used, so that the user's corrected biological value can be accurately judged from the biological value measured by a sensor. Background Art

[0002] Diabetes is a common chronic disease among modern people. In Korea, more than 2 million people, or 5% of the total population, suffer from diabetes.

[0003] Diabetes is caused by a variety of reasons such as obesity, stress, incorrect eating habits, congenital heredity, etc., which leads to an absolute or relative deficiency of insulin produced by the pancreas, which is unable to correct the balance of sugar in the blood, resulting in an absolute increase in the sugar content in the blood.

[0004] Blood normally contains a certain concentration of glucose, from which tissue cells obtain energy.

[0005] However, when glucose increases beyond necessity, it cannot be properly stored in the liver, muscles, or fat cells, etc., but accumulates in the blood. Therefore, the blood sugar level of diabetic patients is maintained much higher than that of normal people. As the excess blood sugar directly passes through the tissues and is excreted in the urine, the sugar that the body's tissues absolutely need becomes insufficient, causing abnormalities in the body's tissues.

[0006] The characteristic of diabetes is that there are almost no conscious symptoms in the early stage, but as the disease progresses, unique symptoms of diabetes such as polydipsia, polyphagia, polyuria, weight loss, general fatigue, itchy skin, and persistent wounds on the hands and feet appear. As the disease progresses further, complications such as visual impairment, hypertension, kidney disease, stroke, periodontal disease, muscle spasms, neuralgia, and gangrene may appear.

[0007] In order to diagnose such diabetes and manage it so that it does not develop into complications, systematic blood sugar measurement and treatment should be performed in parallel.

[0008] Diabetes requires continuous measurement of blood sugar for management, so the demand for devices related to blood sugar measurement is increasing. Various studies have confirmed that when diabetic patients strictly regulate blood sugar, the incidence of diabetic complications is significantly reduced. Accordingly, it is very important for diabetic patients to measure blood sugar regularly to regulate blood sugar.

[0009] Generally, the finger prick method is mainly used to manage the blood sugar of diabetic patients. Although this finger prick method helps to manage the blood sugar of diabetic patients, it is difficult to accurately grasp the frequently changing blood sugar value because it only displays the result at the time of measurement. In addition, the finger prick method requires blood sampling at any time throughout the day to measure blood sugar, which puts a heavy burden on diabetic patients.

[0010] In order to overcome the limitations of such blood sampling type blood glucose measuring instruments, a continuous glucose monitoring system (CGMS) has been developed that is inserted into the human body and measures blood glucose every few minutes, which can be used to easily cope with the management and emergency situations of diabetic patients.

[0011] The continuous blood glucose measurement system includes a sensor transmitter attached to the user's body to measure biological values ​​from interstitial fluid (ISF), and a communication terminal that outputs information about the received biological values ​​to the user. The sensor transmitter is provided with a continuous blood glucose measurement sensor that is partially inserted into the human body, and the sensor is inserted into the human body for a prescribed use period, for example, about 15 days, and continuously measures biological values. The sensor transmitter periodically measures biological values ​​from the body fluid, and a biological management application is provided in the communication terminal to periodically receive biological values ​​from the sensor transmitter and output information about the received biological values ​​to the user.

[0012] The sensor of the sensor transmitter is continuously inserted into the skin during the entire use period, and the sensitivity of the sensor may differ depending on the body part where the sensor is inserted, and even if the insertion position of the sensor in the body part is the same, the sensitivity of the sensor may change over time. Due to the change in sensitivity, there is an error between the biological value measured by the sensor transmitter and the actual biological value of the user. In order to overcome such an error, it is necessary to correct the biological value of the user by applying a correction factor to the measured biological value.

[0013] In order to provide accurate biological values ​​to the user, the biological values ​​received from the sensor transmitter need to be initially calibrated and then continuously calibrated at each prescribed calibration cycle during the use of the sensor transmitter. More specifically, a correction factor is calculated using a reference biological value continuously measured by a separate measuring instrument at each calibration cycle during the use of the sensor transmitter and the biological value received from the sensor transmitter, and the correction factor is applied until the next calibration cycle arrives to calibrate the biological value received from the sensor transmitter.

[0014] The biological value corrected in this way is a body fluid biological value measured from the user's body fluid (interstitial fluid, ISF), and there is a time delay between the body fluid biometric value measured from the body fluid and the blood biological value measured from blood (blood or plasma).

[0015] Figure 1 It is a diagram for explaining the delay model between the biological value of body fluid and the biological value of blood.

[0016] like Figure 1 As shown, blood vessels and body fluids are separated by a capillary barrier, and due to diffusion, there is a time delay for glucose to diffuse from blood vessels to body fluids.

[0017] The body fluid blood sugar level Iglu is calculated as shown in the following formula (1).

[0018] [Mathematical formula 1]

[0019] I glu =I sig ×α+b

[0020] Among them, I sig is the sensor signal representing the biological value measured by the sensor, usually a current value, α is the correction factor, and b is the offset.

[0021] The final blood biological value is calculated using the delay model of the body fluid biological value and the blood biological value as shown in the following mathematical formula (2) and the state transition matrix of the Kalman filter as shown in mathematical formula (3).

[0022] [Mathematical formula 2]

[0023]

[0024] Where B is the final blood biological value and τ is the time delay.

[0025] [Mathematical formula 3]

[0026]

[0027] In addition to the time delay caused by the delay model between the body fluid biological value and the blood biological value, there are also time delays such as delays caused by the physical structure of the sensor itself and calculation delays required to calculate the body fluid biological value from the sensor signal.

[0028] Therefore, the correction factor is calculated from the reference biological value and the sensor signal that is delayed by, for example, 1 minute to 15 minutes from the time when the reference biological value is measured. When calculating the correction factor, when the biological value is stable, there is no large difference between the reference biological value and the sensor signal that is mapped to the reference biological value and is delayed by time, but the time delay of the sensor signal varies depending on the type of sensor or the user, and when the biological value is unstable, the sensor signal that is mapped to the reference biological value and is delayed by time is unstable, so there is a problem that the correction factor cannot be accurately calculated using the reference biological value measured when the biological value is unstable.

[0029] On the other hand, after the sensor is inserted into the body, it takes a certain amount of time until the sensor stabilizes. Before the sensor stabilizes, the reliability of the biological value measured by the sensor is relatively low. After that, as the sensor stabilizes, the reliability of the biological value measured by the sensor also increases relatively. Therefore, when calculating the correction factor based on the reference biological value measured during the process in which the biological value of the user is unstable, it is necessary to calculate the correction factor differently in consideration of the stability of the sensor. Summary of the invention

[0030] Technical issues

[0031] The present invention aims to solve the problems existing in the previous correction factor calculation method mentioned above. One purpose of the present invention is to provide a method for judging whether the biological value is stable based on the difference between the blood biological value and the body fluid biological value, and accurately calculating the correction factor according to whether the user's biological value is unstable.

[0032] Another object of the present invention is to provide a method for calculating the correction factor by dividing the entire use period of the sensor into multiple calibration intervals when calculating the correction factor using the baseline biological value, and accurately calculating the correction factor based on the calibration interval taking into account the degree of stabilization of the sensor.

[0033] Technical Solution

[0034] In order to achieve the purpose of the present invention, the biological signal correction method of the present invention is characterized in that it includes: a step of determining whether a baseline biological value is input; a step of calculating a first biological parameter and a second biological parameter at the time point when the baseline biological value is input; a step of determining whether a correction condition is met based on the first biological parameter and the second biological parameter; a step of calculating a correction factor based on whether the correction condition is met, and a step of calculating a corrected biological value from the biological signal measured by the sensor using the correction factor.

[0035] The biosignal correction method of the present invention is characterized in that, when the correction condition is not satisfied, a current correction factor is calculated from the input reference biovalue, and a corrected biovalue is calculated from the biosignal using the current correction factor until the next reference biovalue is input.

[0036] Preferably, an embodiment of the present invention is characterized in that the step of calculating the blood-corrected biological value includes: a step of calculating a current correction factor from an input baseline biological value when a correction condition is met; a step of judging the correction interval to which the time point of the input baseline biological value belongs; a step of calculating a corrected correction factor from the current correction factor differently according to the correction interval to which the time point of the input baseline biological value belongs based on the judged correction interval; a step of calculating a body fluid-corrected biological value in the body fluid using a biological signal measured by a sensor and the corrected correction factor until the next baseline biological value is input; and a step of applying the body fluid-corrected biological value to a conversion model to calculate a blood-corrected biological value.

[0037] The biological signal correction method of the present invention is characterized in that, for the correction interval, the entire use period of the sensor is divided into a first interval, a second interval, and a third interval as time passes, based on the time point when the sensor is inserted into the body.

[0038] The biological signal correction method of the present invention is characterized in that, for the modified correction factor, when the input reference biological value belongs to the first interval, the current correction factor is calculated as the modified correction factor.

[0039] The biological signal correction method of the present invention is characterized in that, for the modified correction factor, when the time point of inputting the reference biological value belongs to the second interval, the first weight is applied to the current correction factor to calculate the modified correction factor.

[0040] The biological signal correction method of the present invention is characterized in that, for the modified correction factor, when the time point of inputting the reference biological value belongs to the third interval, the second weight is applied to the current correction factor to calculate the modified correction factor.

[0041] The biological signal correction method of the present invention is characterized in that the first biological parameter is the blood sugar level of interstitial fluid (ISF) and the second biological parameter is the blood sugar level of blood (blood or plasma).

[0042] Preferably, the biological signal correction method of the present invention is characterized in that it also includes: a step of calculating the average value of the previously corrected correction factor calculated in the third interval based on the time point of inputting the baseline biological value; and a step of re-correcting the correction factor based on the average value.

[0043] Preferably, an embodiment of the present invention is characterized in that the step of re-correcting the correction factor includes: the step of calculating the correction critical range based on the average value; the step of determining whether the correction factor exceeds the correction critical range; the step of re-correcting the correction factor according to whether the correction factor exceeds the correction critical range to determine the final correction factor, and the final correction factor is used to calculate the corrected biological value.

[0044] The biological signal correction method of the present invention is characterized in that when the modified correction factor exceeds the correction critical range, the modified correction factor is re-corrected to the correction critical range to determine the final correction factor.

[0045] The biological signal correction method of the present invention is characterized in that when the modified correction factor is within the correction critical range, the modified correction factor is determined as the final correction factor.

[0046] Preferably, an embodiment of the present invention is characterized in that the step of re-correcting the correction factor includes: a step of calculating the difference between the corrected correction factor and the average value; a step of calculating the compensation value from the difference between the corrected correction factor and the average value; and a step of calculating the final correction factor by re-correcting the corrected correction factor using the compensation value, and calculating the corrected biological value using the final correction factor.

[0047] Effects of the Invention

[0048] According to the biological signal correction method of the present invention, when the correction factor is calculated using the baseline biological value, whether the biological value is stable is judged by the difference between the blood biological value and the body fluid biological value. When the biological value is unstable, the correction factor calculated from the baseline biological value is not used as it is. Instead, a weight is given to the correction factor, so that the user's biological value can be accurately judged from the biological signal.

[0049] In addition, according to the biological signal correction method of the present invention, when calculating the correction factor using the baseline biological value, the entire use period of the sensor is divided into multiple correction intervals. The correction factor is corrected based on the correction interval to which the time point of the input baseline biological value belongs, taking into account the stabilization degree of the sensor, so that the user's biological value can be accurately calculated from the biological signal of the sensor.

[0050] In addition, according to the biological signal correction method of the present invention, the average value of the correction factor in the sensor stabilization interval is calculated, and the correction factor is re-corrected considering the difference between the corrected correction factor and the average value, so that the user's biological value can be accurately calculated from the biological signal of the sensor in the sensor stabilization interval. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a diagram for explaining the delay model between the biological value of body fluid and the biological value of blood.

[0052] Figure 2 1 is a schematic diagram showing a biological value measuring system according to an embodiment of the present invention.

[0053] Figure 3 This is a functional block diagram for explaining the biological signal correction device of the present invention.

[0054] Figure 4 This is a functional block diagram for explaining the correction unit of the present invention.

[0055] Figure 5 This is a flowchart for explaining the biological signal correction method of the present invention.

[0056] Figure 6 This is a diagram for explaining an example of inputting correction information according to a correction cycle.

[0057] Figure 7 An example of classifying calibration intervals throughout the use period of a sensor according to the present invention is shown.

[0058] Figure 8 This is a flowchart for explaining an example of a method for calculating a correction factor in the present invention.

[0059] Fig. 9 This is a flowchart for explaining an example of the procedure of re-correcting the correction factor in the present invention.

[0060] Fig.10 This is a flowchart for explaining another example of the procedure of re-correcting the correction factor in the present invention. DETAILED DESCRIPTION

[0061] It should be noted that the technical terms used in the present invention are only used to describe specific embodiments and are not used to limit the present invention. In addition, unless otherwise defined in the present invention as having a different meaning, the technical terms used in the present invention should be interpreted as the meanings commonly understood by technicians in the technical field to which the present invention belongs, and should not be interpreted as over-encompassing meanings or over-narrowing meanings. In addition, when the technical terms used in the present invention are erroneous technical terms that cannot accurately express the ideas of the present invention, they should be replaced with technical terms that can be correctly understood by those skilled in the art.

[0062] In addition, singular expressions used in the present invention include plural expressions unless clearly defined differently in the context. In the present invention, terms such as "consisting of" or "comprising" should not be interpreted as necessarily including all constituent elements or steps recorded in the present invention, but should be interpreted as possibly excluding some of the constituent elements or some steps, or possibly further including additional constituent elements or steps.

[0063] In addition, it should be noted that the drawings are only used to facilitate understanding of the concept of the present invention and should not be interpreted as limiting the concept of the present invention through the drawings.

[0064] The method of correcting a biological signal according to the degree of stabilization of a biological value according to the present invention will be described in more detail below with reference to the accompanying drawings.

[0065] Figure 2 1 is a schematic diagram showing a biological value measuring system according to an embodiment of the present invention.

[0066] Hereinafter, a blood sugar level will be described as an example of a biological value, and a reference blood sugar level will be described as an example of a reference biological value, but various biological values ​​other than the blood sugar level may be measured depending on the field to which the present invention is applied.

[0067] Reference Figure 2 A biological value measuring system 1 according to an embodiment of the present invention includes a sensor transmitter 10 and a communication terminal 30 .

[0068] The sensor transmitter 10 is attached to the body. When the sensor transmitter 10 is attached to the body, one end of the sensor of the sensor transmitter 10 is inserted into the skin, and a biological signal representing the blood sugar level, namely, a blood sugar signal, is periodically measured from the body fluid of the human body.

[0069] The communication terminal 30 is a terminal that can receive the blood glucose signal from the sensor transmitter 10, and after correcting the received blood glucose signal using a correction factor to convert the unit into a body fluid blood glucose value, calculate the blood glucose value from the body fluid blood glucose value using a delay model between the body fluid blood glucose value and the blood glucose value, and display the blood glucose value to the user, and can use a terminal such as a smart phone, a tablet PC, or a notebook computer that can communicate with the sensor transmitter 10. Of course, the communication terminal 30 is not limited thereto, and can be any type of terminal as long as it includes a communication function and can be set with a program or application.

[0070] In the present invention, the blood glucose value converted by applying a correction factor to the blood glucose signal measured by the sensor transmitter 10 is called a body fluid blood glucose value, and the blood glucose value calculated from the body fluid blood glucose value using a delay model between the body fluid blood glucose value and the blood glucose value is called a blood blood glucose value. On the other hand, the body fluid blood glucose value or the blood blood glucose value calculated by applying a correction factor to the blood glucose signal is collectively referred to as a corrected blood glucose value. On the other hand, the blood glucose signal received from the sensor transmitter is also referred to as a measured blood glucose value.

[0071] The sensor transmitter 10 transmits the blood glucose signal to the communication terminal 30 based on the request of the communication terminal 30 or periodically at each set time. For data communication between the sensor transmitter 10 and the communication terminal 30, the sensor transmitter 10 and the communication terminal 30 can be connected to each other through a wired method such as a USB cable, or through a wireless communication method such as infrared communication, NFC communication, Bluetooth, etc.

[0072] When communication is established between the sensor transmitter 10 and the communication terminal 30, after the sensor transmitter 10 is initially stabilized, an initial correction factor is calculated using a reference blood sugar value measured by a separate blood sugar meter (not shown), and initial correction is performed on the blood sugar signal using the initial correction factor. Thereafter, the communication terminal 30 corrects the blood sugar signal received from the sensor transmitter 10 using the initial correction factor and outputs and provides the corrected blood sugar value to the user.

[0073] Here, initial stabilization can be determined as a predetermined period of time after the sensor is inserted into the body, such as 2 hours, or initial stabilization can be determined based on the blood glucose signal. Here, initial stabilization is the minimum stabilization time or condition required to inform the user of the corrected blood glucose level as soon as possible after the sensor is inserted into the body, and it may take additional time, such as 1 to 10 days, until the sensor is actually stabilized.

[0074] In order to accurately correct the blood glucose signal by the sensor transmitter 10 after initial stabilization, the communication terminal 30 calculates a new correction factor using the reference blood glucose value measured by a separate blood glucose meter in each calibration cycle during the use of the sensor transmitter 10, and uses the new correction factor to correct the blood glucose signal received from the sensor transmitter.

[0075] Preferably, the calibration cycle may be changed according to the progress of stabilization, for example, after initial stabilization, calibration may be performed at intervals of 12 hours, and thereafter, calibration may be performed at intervals of 24 hours or 48 hours depending on the progress of stabilization.

[0076] Figure 3 This is a functional block diagram for explaining the blood sugar signal correction device of the present invention.

[0077] The blood sugar signal correction device is implemented in a communication terminal such as a smart terminal that communicates with the sensor transmitter and informs the user of the corrected blood sugar value, or is implemented by a separate receiving device.

[0078] refer to Figure 3 More specifically, according to the correction period stored in the storage part 150 , when the correction period arrives, the correction alarm part 130 provides a correction alarm to the user through the user interface part 110 .

[0079] Preferably, when the correction cycle arrives, the correction alarm unit 130 extracts the biological parameters stored in the storage unit 150, and compares the extracted biological parameters with the correction limit conditions. When the correction limit conditions are met, the correction alarm may not be provided to the user interface unit 110, or the correction icon that can input the correction command to the user interface unit 110 may be deactivated. Here, the biological parameters are the blood glucose level of body fluids, the blood glucose level, the rate of change of the blood glucose level, the speed of change of the blood glucose level, etc., and the correction limit conditions may be whether the blood glucose level exceeds the critical limit blood glucose level, and whether the rate of change of the corrected blood glucose level exceeds the critical limit change rate.

[0080] When the reference blood sugar value is inputted through the user interface unit 110 because the correction restriction condition is not satisfied, the correction unit 170 determines the correction interval to which the reference blood sugar value is inputted, or determines whether the correction condition of the correction factor is satisfied based on the biological parameter at the time when the reference blood sugar value is inputted. The correction unit 170 calculates the correction factor based on whether the correction condition of the correction factor is satisfied and the correction interval to which the reference blood sugar value is inputted, and calculates the corrected blood sugar value using the calculated correction factor.

[0081] When the reference blood glucose value is input for calculating the correction factor, the correction unit 170 determines the measured blood glucose value corresponding to the input time of the reference blood glucose value among the measured blood glucose values ​​received by the transceiver unit 190, and generates a correction pair consisting of the reference blood glucose value and the corresponding measured blood glucose value. The correction unit 170 calculates the correction factor using the correction pair. Depending on the field of application of the present invention, the correction unit 170 may calculate the correction factor using the current correction pair consisting of the input reference blood glucose value and the measured blood glucose value corresponding to the reference blood glucose value, but in order to calculate an accurate correction factor, the correction factor may be calculated by a regressive method using the current correction pair and the past correction pair.

[0082] The correction unit 170 may directly use the calculated correction factor or correct the calculated correction factor based on whether the correction condition of the correction factor is satisfied at the time when the reference blood sugar value is input and the correction interval to which the reference blood sugar value is input.

[0083] The correction part 170 calculates a corrected blood sugar value by correcting the measured blood sugar value received after the reference blood sugar value is inputted with the correction factor, and provides the calculated corrected blood sugar value to the user through the user interface part 110 .

[0084] Figure 4 This is a functional block diagram for explaining the correction unit of the present invention.

[0085] refer to Figure 4More specifically, when a reference blood sugar level is input, the correction period determination unit 173 determines the correction period to which the reference blood sugar level at the time of input belongs based on the time of input of the reference blood sugar level.

[0086] On the other hand, the correction condition determination unit 175 determines the first biological parameter and the second biological parameter at the time of inputting the reference blood sugar value, and determines whether the correction condition of the correction factor is satisfied based on the first biological parameter and the second biological parameter. The correction factor calculation unit 177 calculates the current correction factor based on the current correction pair or the past correction pair.

[0087] Based on the correction interval to which the time point of the input benchmark blood sugar value belongs and the first biological parameter and the second biological parameter at the time point of the input benchmark blood sugar value, the correction factor determination unit 171 directly determines the current correction factor calculated by the correction factor calculation unit 177 as the correction factor based on whether the correction condition of the correction factor is satisfied, or causes the correction factor correction unit 178 to correct the current correction factor and determines the corrected correction factor as the correction factor.

[0088] When the correction condition of the correction factor is satisfied at the time point when the reference blood sugar value is input, the correction factor determination unit 171 requests the correction factor correction unit 178 to correct the current correction factor. Upon receiving the correction request for the current correction factor, the correction factor correction unit 178 assigns a weight to the current correction factor according to the correction interval to which the time point when the reference blood sugar value is input belongs, and calculates a corrected correction factor.

[0089] Depending on the degree of stabilization, when the stabilization degree of the sensor is high, it is necessary to maintain the correction factor so that it does not change significantly. When the time point of inputting the reference blood glucose value is judged to be a correction interval with a higher stabilization of the sensor, the correction factor correction unit 178 can re-correct the correction factor based on the average value of the previous correction factor in the correction interval with a higher stabilization of the sensor calculated by the average value calculation unit 179.

[0090] In this way, based on whether the correction condition of the correction factor is satisfied at the time point when the reference blood sugar value is input, when the correction condition is not satisfied, the correction factor determination unit 171 directly uses the calculated current correction factor. However, when the correction condition of the correction factor is satisfied at the time point when the reference blood sugar value is input, the correction factor may be corrected by assigning different weights to the current correction factor according to the correction interval to which the reference blood sugar value is input, or the correction factor may be re-corrected based on the average value of previous correction factors in the correction interval in which the sensor is more stabilized.

[0091] Figure 5 This is a flowchart for explaining the blood sugar signal correction method of the present invention.

[0092] refer to Figure 5More specifically, regardless of the arrival of the correction period or the correction period, it is determined whether or not the reference blood sugar value is input based on the user's request (S110).

[0093] When the reference blood sugar value is input, the correction interval (S130) to which the time point of inputting the reference blood sugar value belongs during the entire use period of the sensor is determined. Here, for the correction interval, the time point of the sensor's body insertion is used as a reference, and as time passes, the entire use period of the sensor can be divided into a first interval, a second interval, and a third interval. The first interval refers to an interval in which the stabilization degree of the sensor is low after the sensor is inserted, the second interval refers to an interval in which the stabilization degree of the sensor is further increased after the first interval, and the third interval is an interval in which the stabilization degree of the sensor is higher than that of the second interval after the second interval. Depending on the field of application of the present invention, the entire use period of the sensor can be divided into a plurality of correction intervals in a diversified manner, and this belongs to the scope of the present invention.

[0094] A correction factor is calculated based on the correction interval to which the time point of the input reference blood sugar value belongs (S150), the measured blood sugar value is corrected using the calculated correction factor and a corrected blood sugar value is calculated, and the calculated corrected blood sugar value is provided to the user (S170).

[0095] The correction factor may be calculated differently depending on whether the time point at which the reference blood sugar value is input satisfies the correction condition of the correction factor in the correction interval to which the time point at which the reference blood sugar value is input belongs.

[0096] Figure 6 The figure is used to explain an example of inputting correction information according to the correction cycle, wherein the correction information is a reference blood sugar level of the user measured by a separate blood sugar meter using a test strip.

[0097] refer to Figure 6 At the time point t1 when the sensor of the sensor transmitter is initially stabilized, the initial correction information is input to the communication terminal. The initial correction information may be input multiple times to accurately calculate the correction factor. The communication terminal calculates the initial correction factor using the initial correction information and the blood sugar value measured by the sensor transmitter, and calculates the corrected blood sugar value of the user by correcting the measured blood sugar value received from the sensor transmitter using the initial correction factor.

[0098] After the sensor of the sensor transmitter is initially stabilized, new calibration information is periodically input to the communication terminal, preferably at a calibration cycle of 12 hours, 24 hours, etc., until the use period of the sensor transmitter expires. After the sensor of the sensor transmitter is initially stabilized, new calibration information is input to the sensor at a first calibration cycle T1 every 12 hours within a prescribed time, and then new calibration information may be input to the sensor of the sensor transmitter at a second calibration cycle T2 of 24 hours, 48 ​​hours, etc.

[0099] When the sensor is manufactured in the same environment and under the same conditions, it will have a certain sensitivity change characteristic (sensitivity drift) after being inserted into the body. Based on this sensitivity change characteristic, the calibration cycle can be set differently according to the manufacturing environment of the sensor.

[0100] Figure 7 An example of classifying calibration intervals throughout the use period of a sensor according to the present invention is shown.

[0101] refer to Figure 7 , the first interval T is The second interval T is the interval in which the sensor has a lower degree of stabilization after the initial stabilization. fs The third interval T is the interval where the sensor is stabilized to an intermediate level after the first interval. es This is a section in which the stabilization degree of the sensor after the second section is higher than that of the second section.

[0102] According to the field of application of the present invention, the first interval can be set to 0.5 days to 1 day from the time when the sensor is inserted into the body, the second interval can be set to 3 days to 5 days from the time when the first interval ends, and the third interval can be set from the time when the second interval ends to the remaining sensor usage period. According to the field of application of the present invention, the first interval, the second interval, and the third interval can be set to different times from each other, which belongs to the scope of the present invention.

[0103] Figure 8 This is a flowchart for explaining an example of a method for calculating a correction factor in the present invention.

[0104] refer to Figure 8 Specifically, it is determined whether the correction interval to which the reference blood sugar value is inputted belongs is the first interval (S171). When the correction interval to which the reference blood sugar value is inputted belongs is the first interval, a current correction factor calculated from the reference blood sugar value and the measured blood sugar value corresponding to the time point at which the reference blood sugar value is inputted is calculated as a revised correction factor (S179).

[0105] On the other hand, when the correction interval to which the time point of inputting the reference blood glucose value belongs is not the first interval, it is determined whether the correction interval to which the time point of inputting the reference blood glucose value belongs is the second interval (S173). When the correction interval to which the time point of inputting the reference blood glucose value belongs is the second interval, it is determined whether the correction condition of the correction factor is satisfied at the time point of inputting the reference blood glucose value (S175). When the correction interval to which the time point of inputting the reference blood glucose value belongs is the second interval, and the correction condition of the correction condition is not satisfied at this time, the current correction factor is calculated as the corrected correction factor (S179). However, when the correction interval to which the time point of inputting the reference blood glucose value belongs is the second interval, and the correction condition of the correction condition is satisfied at this time, the first weight is assigned to the current correction factor to calculate the corrected correction factor (S176, S179).

[0106] For example, when the correction interval to which the reference blood sugar value is input belongs is the second interval and the correction condition of the correction condition is satisfied at this time, the correction factor can be calculated as shown in Math. 1 below.

[0107] [Mathematical formula 1]

[0108] CF R =α1CF C +(1-α1)CF P

[0109] Among them, CF R CF C CF P , α1 refer to the revised correction factor, the current correction factor, the previous correction factor, and the first weight respectively.

[0110] Here, the first weight may be set to be between 0.3 and 0.6. Here, the first weight may be calculated in proportion to the difference between the first bio-parameter and the second bio-parameter within the range of the set first weight.

[0111] On the other hand, when the correction interval to which the reference blood sugar value is inputted belongs is not the second interval, the correction interval to which the reference blood sugar value is inputted belongs is determined to be the third interval, and it is determined whether the correction condition of the correction factor is satisfied at the time point of the reference blood sugar value inputted (S177). When the correction interval to which the reference blood sugar value is inputted belongs is the third interval, and the correction condition of the correction factor is not satisfied at this time, the current correction factor is calculated as the corrected correction factor (S179). However, when the correction interval to which the reference blood sugar value is inputted belongs is the third interval, and the correction condition of the correction factor is satisfied at this time, the second weight is assigned to the current correction factor to calculate the corrected correction factor (S178, S179).

[0112] For example, when the correction interval to which the reference blood sugar value is input belongs is the third interval and the correction parameter satisfies the correction condition at this time, the correction factor can be calculated as shown in Math. 2 below.

[0113] [Mathematical formula 2]

[0114] CF R =α2CF C +(1-α2)CF P

[0115] Among them, CF R CF C CF P , α2 refer to the revised correction factor, the current correction factor, the previous correction factor, and the second weight respectively.

[0116] Here, the second weight may be set to 0.6 to 0.9. Here, within the set second weight range, the second weight may be calculated in proportion to the difference between the first bio-parameter and the second bio-parameter.

[0117] Here, the correction condition is a condition for determining whether the biological value of the user is unstable, and may be set differently or identically in each calibration interval.

[0118] For example, an example of the correction condition is as follows.

[0119] 1) When the baseline blood glucose value exceeds the upper critical blood glucose value, and at the same time, the current correction factor is greater than the previous correction factor;

[0120] 2) When the baseline blood glucose value is less than the lower critical blood glucose value, and the previous correction factor is greater than the current correction factor;

[0121] 3) When the difference between the first biological parameter and the second biological parameter exceeds a critical value.

[0122] In the present invention, the first biological parameter may be a blood glucose level, and the second biological parameter may be a body fluid blood glucose level. The blood glucose level may be calculated using the delay model between the blood glucose level and the body fluid blood glucose level described above.

[0123] When the user's biological value is stable, the difference between the blood glucose value and the body fluid blood glucose value is not large, but when the user's biological value is unstable, a significant difference between the blood glucose value and the body fluid blood glucose value can be confirmed. Therefore, when the difference between the blood glucose value and the body fluid blood glucose value exceeds the critical value, it can be determined that the user's biological value is unstable.

[0124] Fig. 9 This is a flowchart for explaining an example of the procedure of re-correcting the correction factor in the present invention.

[0125] When the calibration interval to which the reference blood sugar value is input belongs is the third interval, since the sensor is more stabilized in the third interval, it is necessary to maintain the calibration factor so that it does not change significantly. To this end, the calibration factor can be recalibrated to follow the average value of the calibration factors calculated in the third interval.

[0126] refer to Fig. 9 Specifically, the average value of the previously corrected correction factor is calculated in the third interval based on the time point of inputting the reference blood glucose value (S211), and the correction critical range is calculated based on the calculated average value (S213). Here, the previously corrected correction factor is a correction factor previously obtained based on the time point of inputting the reference blood glucose value.

[0127] It is determined whether the modified correction factor exceeds the critical correction range (S215), and based on whether the modified correction factor exceeds the critical correction range, the modified correction factor is re-corrected to determine the final correction factor (S217).

[0128] That is, when the modified correction factor exists in the correction critical range, the modified correction factor is determined as the final correction factor. However, when the modified correction factor exceeds the correction critical range, the modified correction factor is re-corrected to the correction critical range to determine the final correction factor (S219). When the final correction factor is determined, the corrected blood sugar level is calculated using the final correction factor.

[0129] For example, when the modified correction factor exceeds the upper limit of the modified critical range, the modified correction factor is re-corrected to the upper limit of the modified critical range; when the modified correction factor exceeds the lower limit of the modified critical range, the modified correction factor is re-corrected to the lower limit of the modified critical range.

[0130] Fig.10 This is a flowchart for explaining another example of the procedure of re-correcting the correction factor in the present invention.

[0131] refer to Fig.10 More specifically, based on the time point when the reference blood sugar value is input, the average value of the previously corrected correction factor is calculated in the third interval (S221), and the compensation value is calculated based on the calculated average value (S223).

[0132] Here, the compensation value may be calculated in consideration of the difference between the modified correction factor and the average value so that the modified correction factor follows the average value, and the compensation value may be calculated as shown in Math. 4 below.

[0133] [Formula 4]

[0134] CF R2 =CF R -(CF R-CF M )×α3

[0135] Among them, CF R2 CF R CF M , α3 refer to the final correction factor, the modified correction factor, the average value, and the third weight, respectively. (CF R -CF M )×α3 refers to the compensation value.

[0136] Here, the third weight may be set to 0.7 to 0.9.

[0137] For example, the third weight can be set to 0.8. When the correction factor is 10 and the average value is 8, the final correction factor can be calculated using CF R2 =10-(10-8)×0.8=8.4 is re-corrected to follow the mean.

[0138] On the other hand, the embodiments of the present invention described above may be written as a program that can be executed on a computer, and may be implemented in a general-purpose digital computer that runs the program using a computer-readable recording medium.

[0139] The computer-readable recording media include storage media such as magnetic storage media (e.g., ROM, floppy disks, hard disks, etc.), optical reading media (e.g., CD-ROM, DVD, etc.), and carrier waves (e.g., transmission through the Internet).

[0140] Although the present invention is described with reference to the embodiments shown in the drawings, this is merely exemplary, and those skilled in the art will appreciate that various modifications and other equivalent embodiments may be made. Therefore, the true technical protection scope of the present invention should be defined by the technical ideas of the appended claims.

Claims

1. A biological signal correction method, characterized in that: include: The step of determining whether to input a baseline biological value; The step of acquiring a first biological parameter and a second biological parameter at a time point when the reference biological value is input; A step of determining whether a correction condition is satisfied based on the first biological parameter and the second biological parameter; as well as A step of acquiring a correction factor according to whether the correction condition is satisfied, and acquiring a corrected biological value from the biological signal using the correction factor.

2. The biological signal correction method according to claim 1, characterized in that: The step of obtaining a corrected biological value from the biological signal comprises: When the correction condition is not met, calculating a current correction factor from the inputted baseline biological value; and The step of obtaining the corrected bio-value from the bio-signal based on the current correction factor.

3. The biological signal correction method according to claim 1, characterized in that: The step of obtaining a corrected biological value from the biological signal comprises: When the correction condition is met, The step of obtaining a current correction factor from the inputted reference biological value; The step of determining the correction interval to which the time point of inputting the reference biological value belongs; A step of obtaining a modified correction factor from a current correction factor based on the determined correction interval; The step of measuring the biological signal using a sensor; A step of obtaining a corrected biological value of a body fluid based on the biological signal and the modified correction factor; and The step of obtaining a blood-corrected biological value based on the body fluid-corrected biological value.

4. The biological signal correction method according to claim 3, characterized in that: The correction section is divided into a first section, a second section following the first section, and a third section following the second section.

5. The biological signal correction method according to claim 4, characterized in that: When the time point of inputting the reference biological value belongs to the first interval, The revised correction factor is the current correction factor.

6. The biological signal correction method according to claim 4, characterized in that: When the time point of inputting the reference biological value belongs to the second interval, The step of obtaining the modified correction factor from the current correction factor comprises: The step of applying a first weight to said current correction factor.

7. The biological signal correction method according to claim 4, characterized in that: When the time point of inputting the reference biological value belongs to the third interval, The step of obtaining the modified correction factor from the current correction factor comprises: The step of applying a second weight to said current correction factor.

8. The biological signal correction method according to any one of claims 1 to 7, characterized in that: The first biological parameter is a body fluid blood glucose level, and the second biological parameter is a blood blood glucose level.

9. The biological signal correction method according to claim 4, characterized in that: Also includes: When the time point of inputting the reference biological value belongs to the third interval, the step of obtaining at least one previously modified correction factor; a step of obtaining an average value of said previously modified correction factors; and The step of revising the correction factor based on the average value.

10. The biological signal correction method according to claim 9, characterized in that: The step of re-correcting the correction factor comprises: A step of obtaining a modified critical range based on the average value; A step of determining whether the modified correction factor exceeds the modified critical range; and According to whether the correction factor exceeds the correction critical range, re-correcting the correction factor, And also includes: The step of obtaining a final correction factor based on the re-corrected correction factor; and The step of calculating said corrected biological value based on said final correction factor.

11. The biological signal correction method according to claim 10, characterized in that: Also includes: When the correction factor exceeds the correction critical range, The step of re-correcting the correction factor so that the correction factor belongs to the correction critical range.

12. The biological signal correction method according to claim 10, characterized in that: When the correction factor is within the correction critical range, The modified correction factor is the final correction factor.

13. The biological signal correction method according to claim 9, characterized in that: The step of re-correcting the correction factor also includes: A step of obtaining a difference between the modified correction factor and the average value; A step of obtaining a compensation value based on a difference between the modified correction factor and the average value; and The step of re-correcting the correction factor based on the compensation value, And also includes: The step of obtaining a final correction factor based on the re-corrected correction factor; and The step of obtaining said corrected biological value based on said final correction factor.

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