Blood glucose concentration calculation method and sensor

Abstract

The invention discloses a blood glucose concentration calculation method and a sensor, and relates to the technical field of blood glucose concentration detection. A first excitation signal and a second excitation signal are input into a first working electrode, after the excitation signals of the first working electrode are completed, the first working electrode is in an open circuit state, and then input of an excitation signal sequence to a second working electrode is started; after the excitation signal sequence of the second working electrode is completed, the second working electrode is in an open circuit state, then a second excitation signal of the first working electrode is started, and the first excitation signal, the second excitation signal and the output current of a current acquisition point of the excitation signal sequence are acquired at regular intervals; and obtaining the concentration of blood glucose through a calculation formula. According to the blood glucose concentration calculation method disclosed by the invention, the mutual influence relationship among various interference factors related to the blood glucose concentration is considered, and the accuracy and precision of testing the blood glucose concentration in the biological sample are further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of blood glucose concentration detection. Specifically, it relates to a method for calculating blood glucose concentration and a sensor for analyzing analytes in biological samples. Background Art

[0002] Traditional biosensors achieve test selectivity through the catalytic action of biomolecules in a single reaction, which is based on two chain reactions. Among them, the reduced form of the mediator in the second reaction (the comb flow reaction) diffuses to the electrode and is then oxidized to generate a corresponding current signal. The catalytic process of the analyte can be described by the following three steps:

[0003] (1) Analyte + oxidized enzyme = biochemical reaction product + reduced enzyme

[0004] (2) Oxidized mediator + reduced enzyme = reduced mediator + oxidized enzyme

[0005] (3) Reduced mediator (electrode) = oxidized mediator + e-

[0006] The enzyme biomolecule of the glucose detection sensor system solely catalyzes the oxidation of glucose molecules in the blood. The added mediator reacts with the enzyme to convert the enzyme back from the reduced state to the oxidized state, thus playing a comb flow role. The glucose enzyme can be an oxidase or a dehydrogenase. Since oxidase is oxidized by dissolved oxygen in the blood sample while dehydrogenase is not, there is no "dissolved oxygen effect". Dehydrogenase has been the preferred enzyme in biosensors in the past two decades. The catalytic enzymes for other analytes may be oxidases or dehydrogenases, and the principles of their biosensors are basically the same. However, during the test, although the enzyme-catalyzed reaction is basically single, there may be other oxidizable interfering substances in the blood sample. These interfering substances may undergo oxidation reactions, resulting in interference signals. Generally speaking, the higher the standard potential of the mediator in the comb flow reaction, such as ferricyanide (Fe(CN)6 -3 ), the more likely it is to generate interference signals because the higher the electrode oxidation potential, the more interfering substances will be oxidized.

[0007] In addition to the above chemical interferents, there are other test interferences in glucose detection sensors. For example, the percentage of hematocrit (%-HCT) is a relatively obvious interference factor. This interference is due to the fact that during the diffusion of the mediator after the flow-through reaction to the electrode, the diffusion is hindered by blood cells, resulting in the change of the diffusion coefficient due to %-HCT. And the current in the electrochemical reaction will be affected by different %-HCT. Therefore, the factory batch calibration of the sensor test strips is usually centered around 42% HCT. If the user's %HCT is higher than 42%, a negative deviation will occur in the test. If the user's %HCT is lower than 42%, a positive deviation will occur in the test. In addition, the aging effect generated during the storage time of the test strips will also interfere with the blood glucose test results, that is, as the storage time prolongs, the sensitivity of the sensor test relatively declines, or more oxidizable substances for background signals will be generated. In addition, the interference factors also include the test temperature.

[0008] Traditional blood glucose detection sensors generally apply a voltage to the electrode in contact with the analyte sample to oxidize the reduced mediator generated after the flow-through reaction, thereby generating a current signal responsive to the analyte. Through corresponding calculation methods, the current signal is converted into the analyte concentration. For the interference factors in the test process, most of the existing methods use different single parameters to perform exclusion or weakening of interference compensation, so as to achieve the purpose of improving the test accuracy and precision. However, these methods of using single parameters for interference compensation often ignore the mutual influence relationship between multiple interference factors. For example, the mutual influence between temperature and HCT, the mutual influence between temperature and test strip aging, the mutual influence between HCT and test strip aging, and so on.

[0009] Therefore, in order to avoid the generation of interference signals, there is still a large room for improvement in the method for testing blood glucose concentration in biological samples in terms of multi-pulse excitation and multi-parameter compensation, so as to further improve the accuracy and precision of testing blood glucose concentration in biological samples. Summary of the Invention

[0010] In order to solve the above problems, the present invention discloses a method for calculating blood glucose concentration, and its purpose is to solve the technical problem that the method of using a single parameter for interference compensation in the prior art often ignores the mutual influence relationship between multiple interference factors, resulting in low accuracy and precision of blood glucose concentration testing.

[0011] On the one hand, the present invention provides a method for calculating blood glucose concentration, which is applied to a biological sample analyte testing device. The biological sample analyte testing device includes a first working electrode and a second working electrode. The first working electrode is covered with a first chemical agent that can react with the analyte. The second working electrode is a blank electrode, covered with an inert substance that does not chemically react with the analyte, or covered with a second chemical agent different from the first chemical agent. A first excitation signal and a second excitation signal are input to the first working electrode, and after each excitation signal is completed, the first working electrode is in an open circuit state.

[0012] Between the first excitation signal and the second excitation signal, an excitation signal sequence is input to the second working electrode. After the excitation signal sequence is completed, the second working electrode is in an open circuit state. Wherein, the excitation signal sequence includes at least two consecutive or non-consecutive input signals, and each input signal is a constant value.

[0013] The output current at the current acquisition points of the first excitation signal, the second excitation signal, and the excitation signal sequence is collected at regular intervals to obtain an output current group, and the concentration of the blood glucose is obtained. The calculation method of the blood glucose concentration G is as follows:

[0014]

[0015]

[0016]

[0017] Wherein, i 平均 is the average value of the output currents at at least two current acquisition points in the second excitation signal, in nA; S is the slope of the linear equation of i 平均 and the glucose concentration; i n and i j are both output currents in the output current group, in nA; i 差 is the difference between the maximum output current of the excitation signal sequence and the output current at the last acquisition point, in nA; the value range of N is 10 to 53; the value range of J is 10 to 53; the value range of X n is -500 to 500; the value range of X j is -15 to 15; the value range of K is -30 to 0.

[0018] This calculation method inputs a first excitation signal and a second excitation signal to the first working electrode, and inputs an excitation signal sequence to the second working electrode between the first excitation signal and the second excitation signal. The input signals to the first and second working electrodes do not overlap in time. That is, after the excitation signal for the first working electrode is completed, the control of the first working electrode by the test device is in an open circuit state, and then the excitation signal sequence is started to be input to the second working electrode. After the excitation signal sequence for the second working electrode is completed, the control of the second working electrode by the test device is in an open circuit state, and then the second excitation signal for the first working electrode is started. The excitation signals input to the first and second working electrodes are defined as the "sandwich excitation method".

[0019] Further, it also includes the step of applying an alternating voltage to the second working electrode before inputting the first excitation signal to the working electrode to measure the impedance value of blood glucose, and obtaining the concentration of the blood glucose according to the output current group and the impedance value, where,

[0020]

[0021] where, R is the impedance value, Ω; i m is the output current in the output current group, nA; M ranges from 10 to 53; X m ranges from -120 to 120.

[0022] Further, it also includes the step of obtaining the measured ambient temperature, and obtaining the concentration of the blood glucose according to the output current group, the impedance value and the temperature, where,

[0023]

[0024] where, T is the ambient temperature, °C; i u is the output current in the output current group, nA; U ranges from 10 to 53; X u ranges from -7 to 3.

[0025] Optionally, the excitation time of the first excitation signal is 0.1 - 1 s, and the excitation time of the second excitation signal is 0.1 - 2 s.

[0026] Preferably, the excitation time of the first excitation signal is 0.5 s, and the excitation time of the second excitation signal is 1.25 s.

[0027] Optionally, i 平均 is the average value of the output currents at the last 5 current acquisition points in the second excitation signal.

[0028] Optionally, the voltage value of the first excitation signal is 0.2 - 0.4 V, and the voltage value of the second excitation signal is 0.2 - 0.4 V.

[0029] Preferably, the voltage values of the first excitation signal and the second excitation signal are both 0.3V.

[0030] Optionally, the total application time of the excitation signal sequence is at least 1s, and the application time of each input signal in the excitation signal sequence is 0.1 - 0.3s.

[0031] Preferably, the application time of each input signal in the excitation signal sequence is equal, both being 0.2s.

[0032] Optionally, the voltage range of the excitation sequence is 0.1 - 3V, and the excitation signal sequence includes 4 - 8 consecutive input signals.

[0033] Preferably, the excitation signal sequence includes 5 consecutive input signals, and the voltage values of the 5 consecutive input signals are 0.3V, 0.8V, 1.2V, 1.7V, and 2.2V respectively.

[0034] Optionally, the output current at the current acquisition points of the first excitation signal, the second excitation signal, and the excitation signal sequence is collected every 0.05s.

[0035] On the other hand, the present invention provides an analyte sensor for testing biological samples, and the sensor can perform the above - mentioned blood glucose concentration calculation method.

[0036] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0037] (1) The blood glucose concentration calculation method of the present invention takes into account the mutual influence relationship among various interference factors related to blood glucose concentration, and further improves the accuracy and precision of testing blood glucose concentration in biological samples.

[0038] (2) The blood glucose concentration calculation method of the present invention takes into account the mutual influence relationship among various interference factors related to blood glucose concentration, which provides the possibility for barcode - free production of test strips. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The drawings described herein are used to provide a further understanding of the present invention, and constitute a part of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention, and do not constitute an improper limitation of the present invention. In the drawings:

[0040] Figure 1 An exemplary embodiment showing the main excitation signal schematic diagram of the sandwich excitation method of the present invention;

[0041] Figure 2 An exemplary embodiment showing the linear relationship diagram of i of the present invention 平均 with glucose concentration;

[0042] Figure 3 Shows the deviation comparison chart before and after calibration in Example 1;

[0043] Figure 4 Shows the deviation comparison chart before and after calibration in Example 2;

[0044] Figure 5 Shows the deviation comparison chart before and after calibration in Example 3;

[0045] Figure 6 Shows the deviation comparison chart after calibration for Examples 1 - 3. Detailed implementation manner

[0046] In order to more clearly illustrate the overall concept of the present invention, the following will be described in detail by way of examples in conjunction with the accompanying drawings of the specification.

[0047] In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited by the specific embodiments disclosed below. In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0048] The excitation described in the disclosure of the present invention is to apply an input signal to the electrodes in a biological testing device (such as a sensor), where the applied signal includes positive and negative DC constant voltages or positive and negative DC constant current sources, etc., so that a complete or partial oxidation or reduction reaction occurs on the electrode surface. The system processing center of the biological testing device applies an excitation input signal to the corresponding electrodes through the connection port end between the instrument and the test strip. When the predetermined excitation time ends, the system will no longer apply a signal to the electrodes, and the electrodes will be in an open - circuit state. The open - circuit state is not zero input. For example, applying a voltage of 0V (zero volts) to the electrode is not equal to an open - circuit. Zero voltage is also a kind of input voltage. After the electrodes are in an open - circuit state, the oxidation - reduction substances on the electrode surface and in the vicinity will cause the attenuation process of the residual signal. This attenuation signal will give information reflecting the state that the electrodes have experienced, so as to record other information related to the analyte of the biological testing device.

[0049] Example 1

[0050] The method for calculating blood glucose concentration is applied to a biological sample analyte testing device, which includes a first working electrode and a second working electrode. The first working electrode is covered with a first chemical agent that can react with the analyte. Specifically, the first chemical agent includes a bioenzyme that can catalyze the reaction of the analyte, one or more mediators that can generate a combing effect between the enzyme reaction and the electrode reaction, and an inert substance that aids the chemical agent. The second working electrode is a blank electrode, covered with an inert substance that does not chemically react with the analyte, or covered with a second chemical agent different from the first chemical agent. A first excitation signal and a second excitation signal are input to the first working electrode, and after each excitation signal is completed, the first working electrode is in an open-circuit state.

[0051] Between the first excitation signal and the second excitation signal, an excitation signal sequence is input to the second working electrode. After the excitation signal sequence is completed, the second working electrode is in an open-circuit state; wherein, the excitation signal sequence includes at least two continuous or discontinuous input signals, and each input signal is a constant value;

[0052] The output current at the current acquisition points of the first excitation signal, the second excitation signal, and the excitation signal sequence is collected at regular intervals to obtain an output current group, and the concentration of the blood glucose is obtained. The calculation method of the blood glucose concentration G is obtained by Equation 1;

[0053] Equation 1 is And G in Equation 1 计算 is obtained by Equation 2, and f in Equation 1 is obtained by Equation 3. f is a multi-parameter calibration factor.

[0054] Equation 2 is wherein, i 平均 is the average value of the output currents at at least two current acquisition points in the second excitation signal, in nA; S is the slope of the linear equation between i 平均 and the glucose concentration. Exemplarily, S is obtained by linear fitting of the known historical i 平均 and the historical glucose concentration. Or, the linear relationship between the historical i 平均 and the historical glucose concentration is directly tabulated through statistical laws, and the slope S value is obtained by looking up the table.

[0055] Equation 3 is

[0056] wherein, i n and i j are both output currents in the output current group, in nA; i 差 is the difference between the maximum output current of the excitation signal sequence and the output current at the last acquisition point, in nA; the value range of N is 10 to 53; the value range of J is 10 to 53; Xn ranges from -500 to 500; X j ranges from -15 to 15; K ranges from -30 to 0.

[0057] Optionally, i n and i j can be the output currents of consecutive acquisition points in the output current group. For example, i n can be i1, i2, i3, i4, i5, i6, i7, i8, i9, i 10 ; i j can be i6, i7, i8, i9, i 10 , i 11 , i 12 , i 13 , i 14 , i 15 . Optionally, i n and i j can be the output currents of non-consecutive acquisition points in the output current group. For example, i n can be i3, i5, i 11 , i 13 , i 21 ; i j can be i1, i2, i9, i 17 , i 20 , i 29 , i 30 . However, the present invention is not limited thereto, and those skilled in the art can select the values of i n and i j according to the statistical significance test method.

[0058] Optionally, the excitation time of the first excitation signal is 0.1 - 1 s, and the excitation time of the second excitation signal is 0.1 - 2 s; preferably, the excitation time of the first excitation signal is 0.5 s, and the excitation time of the second excitation signal is 1.25 s.

[0059] Optionally, i 平均 is the average value of the output currents of at least three current acquisition points in the second excitation signal. For example, i 平均 is the average value of the output currents of the last 5 current acquisition points in the second excitation signal.

[0060] Optionally, the voltage value of the first excitation signal is 0.2 - 0.4 V, and the voltage value of the second excitation signal is 0.2 - 0.4 V; preferably, the voltage values of the first excitation signal and the second excitation signal are both 0.3 V.

[0061] Optionally, the total application time of the excitation signal sequence is at least 1 s, and the application time of each input signal in the excitation signal sequence is 0.1 - 0.3 s; preferably, the application time of each input signal in the excitation signal sequence is equal, all being 0.2 s.

[0062] Optionally, the voltage range of the excitation sequence is 0.1 - 3 V, and the excitation signal sequence includes 4 - 8 consecutive input signals; preferably, the excitation signal sequence includes 5 consecutive input signals, and the voltage values of the 5 consecutive input signals are 0.3 V, 0.8 V, 1.2 V, 1.7 V, and 2.2 V respectively.

[0063] Optionally, the output current at the current acquisition point of the first excitation signal, the second excitation signal, and the excitation signal sequence is acquired every 0.05 s.

[0064] Example 2

[0065] Based on Example 1, the main difference is that it further includes the step of applying an alternating voltage to the second working electrode before applying the first excitation signal to the working electrode to measure the impedance value of blood glucose, and obtaining the concentration of the blood glucose according to the output current group and the impedance value, where

[0066]

[0067] where, R is the impedance value, Ω; i m is the output current in the output current group, nA; M ranges from 10 to 53; X m ranges from -120 to 120.

[0068] Compared with Example 1, in Example 2, the mutual influence between the impedance value and the output current is further considered.

[0069] Example 3

[0070] Based on Example 2, it further includes the step of obtaining the measured environmental temperature, and obtaining the concentration of the blood glucose according to the output current group, the impedance value, and the temperature, where

[0071]

[0072] where, T is the environmental temperature, °C; i u is the output current in the output current group, nA; U ranges from 10 to 53; X u ranges from -7 to 3.

[0073] Compared with Example 2, in Example 3, the mutual influence between the impedance value, the environmental temperature, and the output current is further considered.

[0074] Experimental Example

[0075] The sensor capable of performing the blood glucose concentration calculation method of the above Embodiments 1-3 is used to detect the blood sample to be tested. A calculation module is provided in the sensor. The calculation module includes calculation formulas. The method and process of storing the calculation module are prior arts and can be implemented by those skilled in the art, so they will not be elaborated in this embodiment.

[0076] In this test method, the test time and potential control are as follows: (1) The pre-test neutral gear is 1.25 seconds; during the test neutral gear, an alternating voltage can be applied to the second working electrode to measure the impedance value of blood glucose; (2) Apply a first excitation signal to the first working electrode, input a potential difference of 0.3V to the first working electrode and the corresponding electrode, and last for 0.5 seconds, and synchronously measure the output current at intervals of every 0.05 seconds; (3) After the first excitation signal ends, set the first working electrode to an open circuit state, and measure the first potential decay signal of the first working electrode at intervals of every 0.005 seconds, lasting for 0.5 seconds; (4) While the first working electrode is continuously in the open circuit state, input an excitation signal sequence to the second working electrode and the corresponding electrode. The excitation signal sequence includes 5 excitations, and the excitation voltages are 0.3V, 0.8V, 1.2V, 1.7V, and 2.2V in sequence. The duration of each excitation is 0.2 seconds, and the output current is synchronously measured at intervals of every 0.05 seconds; (5) Set the second working electrode to an open circuit state; (6) After the first working electrode is open for 2.0 seconds, apply a second excitation signal to the first working electrode, with a voltage of 0.3V, lasting for 1.25 seconds, and synchronously measure the output current at intervals of every 0.05 seconds; (7) After the second excitation signal ends, set the first working electrode to an open circuit state, and measure the potential decay signal of the corresponding electrode at intervals of every 0.005 seconds, lasting for 0.5 seconds. The total time of the above test steps is 1.25 + 0.5 + 2 + 1.25 + 0.5 = 5.5 seconds. Refer to Figure 1 as shown Figure 1 shows a schematic diagram of the main excitation signals of the sandwich excitation method Figure 1 In the figure, the horizontal axis represents the sensor test time, and the vertical axis represents the excitation signal strength, which is the voltage applied to the electrode.

[0077] Refer to Figure 2 as shown Figure 2 shows the historical i 平均 and the linear relationship diagram with the historical glucose concentration, and the slope S is 22.181. In Embodiments 1-3, i 平均 is the average value of the output currents of the last 5 current acquisition points in the second excitation signal.

[0078] In Embodiment 1, f = -18.78 + 1.068i3 / i 平均 + 3.46i5 / i 平均-5.58i6 / i 平均 -5.14i9 / i 平均 +6.51i 10 / i 平均 -11.95i 12 / i 平均 -8.05i 18 / i 平均 +3.355i 21 / i 平均 +4.292i 23 / i 平均 -6.792i 24 / i 平均 +0.991i 26 / i 平均 +0.3292i 30 / i 平均 +0.4228i 31 / i 平均 -2.718i 32 / i 平均 +1.779i 33 / i 平均 +0.790i 37 / i 平均 +18.22i 52 / i 平均 -0.1262i 差 i2 / i 平均 -0.2950i 差 i4 / i 平均 +2.740i 差 i8 / i 平均 -2.310i 差 i9 / i 平均 +1.201i 差 i 11 / i 平均 +1.653i 差 i 18 / i 平均 -0.909i 差 i 22 / i 平均 -1.059i 差 i 23 / i 平均 +1.466i 差 i 24 / i 平均 -0.01481i 差 i 27 / i 平均 -0.04952i 差 i 29 / i 平均+0.3606i 差 i 32 / i 平均 -0.3276i 差 i 34 / i 平均 -0.298i 差 i 39 / i 平均 +0.228i 差 i 48 / i 平均 ;

[0079] In Example 2, f = -27.81 - 33.79i 12 / i 平均 +11.87i 19 / i 平均 +1.321i 23 / i 平均 -6.96i 26 / i 平均 -0.2726i 29 / i 平均 +0.1939i 31 / i 平均 +1.046i 33 / i 平均 +28.46i 52 / i 平均 -0.0742i 差 i2 / i 平均 +0.2468i 差 i8 / i 平均 +1.290i 差 i 11 / i 平均 -0.2111i 差 i 22 / i 平均 -0.3908i 差 i 23 / i 平均 +0.6853i 差 i 26 / i 平均 -0.02858i 差 i 30 / i 平均 +0.0447i 差 i 31 / i 平均 +0.3847i 差 i 33 / i 平均 -0.675i 差 i 34 / i 平均 +0.599i差 i 37 / i 平均 -0.580i 差 i 39 / i 平均 +0.689Ri5 / i 平均 -0.839Ri6 / i 平均 +8.36Ri 13 / i 平均 -2.831Ri 19 / i 平均 +1.103Ri 26 / i 平均 -0.02016Ri 27 / i 平均 +0.1339Ri 30 / i 平均 -0.3000Ri 32 / i 平均 ;

[0080] In Example 3, f = -18.27 - 51.0i 11 / i 平均 -3.232i 24 / i 平均 +4.20i 27 / i 平均 -4.77i 30 / i 平均 +12.12i 31 / i 平均 -13.90i 32 / i 平均 -440i 51 / i 平均 +476i 52 / i 平均 +2.690i 差 i 12 / i 平均 +2.24i 差 i 14 / i 平均 -0.541i 差 i 23 / i 平均 +0.675i 差 i 24 / i 平均 +0.0220i 差 i 28 / i 平均 -0.1763i 差 i 29 / i 平均 +0.1496i 差 i 30 / i平均 +0.0723i 差 i 31 / i 平均 -0.2146i 差 i 34 / i 平均 +0.890i 差 i 39 / i 平均 -0.908i 差 i 41 / i 平均 +11.34Ri 11 / i 平均 +0.659Ri 23 / i 平均 -1.100Ri 27 / i 平均 +1.258Ri 30 / i 平均 -3.069Ri 31 / i 平均 +3.511Ri 32 / i 平均 +112.4Ri 51 / i 平均 -116.8Ri 52 / i 平均 -0.0202TG 计算 i 差 i2 / i 平均 +0.0574TG 计算 i 差 i3 / i 平均 -0.0318TG 计算 i 差 i4 / i 平均 +2.381TG 计算 i 差 i 11 / i 平均 -6.085TG 计算 i 差 i 12 / i 平均 +0.0665TG 计算 i 差 i 19 / i 平均 -0.1297TG 计算 i 差 i 22 / i 平均 -0.1133TG 计算 i 差 i 23 / i 平均 +0.1401TG 计算i 差 i 26 / i 平均 +0.03416TG 计算 i 差 i 27 / i 平均 +0.1098TG 计算 i 差 i 29 / i 平均 -0.1481TG 计算 i 差 i 30 / i 平均 -0.0645TG 计算 i 差 i 32 / i 平均 +0.0833TG 计算 i 差 i 33 / i 平均 -0.0434TG 计算 i 差 i 36 / i 平均 +0.02523TG 计算 i 差 i 53 / i 平均 ;

[0081] To verify the accuracy of the detection method in this embodiment, the following verification is carried out:

[0082] 1. Determine the reference value of blood glucose concentration. The reference value of blood glucose concentration is determined by a YSI 2300 blood glucose analyzer.

[0083] 2. Calculate the deviation. The deviation is the absolute deviation, and the deviation = the measured value of blood glucose concentration - the reference value of blood glucose concentration.

[0084] Referring to Table 1 shown below, Table 1 shows the proportion of the deviations of Examples 1-3 from the reference value of blood glucose concentration within each range.

[0085] Table 1

[0086]

[0087] Referring to Table 1 shown below, it can be seen that the blood glucose concentration calculated by the present invention has a deviation of 66% within ±10%, 85% within ±15%, and 95% within ±20% compared with the reference value of blood glucose concentration measured by the YSI 2300 blood glucose analyzer.

[0088] Refer to Figures 3 - 5 shown below, which respectively shows the deviation comparison diagrams before and after calibration of Examples 1-3. Among them, before calibration in the figure represents G计算 Comparison chart of deviation from blood glucose concentration reference value. In the chart, after calibration, it represents the comparison chart of the deviation between the detected value G of the blood glucose concentration of the present invention and the blood glucose concentration reference value. Figure 6 The deviation comparison charts after calibration for Examples 1-3 are shown. It can be seen that the calculation method of blood glucose concentration after calibration of the present invention comprehensively considers the mutual influence relationship among various interference factors related to blood glucose concentration, and further improves the accuracy and precision of measuring blood glucose concentration in biological samples.

[0089] The above are only the embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, various modifications and changes can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims

1. A method for calculating blood glucose concentration, characterized in that, Applied to a biological sample analyte testing device, the biological sample analyte testing device includes a first working electrode and a second working electrode. The first working electrode is covered with a first chemical agent that can react with the analyte. The second working electrode is a blank electrode, covered with an inert substance that does not chemically react with the analyte, or covered with a second chemical agent different from the first chemical agent. A first excitation signal and a second excitation signal are input to the first working electrode, and after each excitation signal is completed, the first working electrode is in an open-circuit state; After the excitation signal sequence is completed, the second working electrode is in an open-circuit state; wherein, the excitation signal sequence includes at least two consecutive or non-consecutive input signals, and each input signal is a constant value; The output current at the current acquisition points of the first excitation signal, the second excitation signal, and the excitation signal sequence is collected at regular intervals to obtain an output current group, and the concentration of blood glucose is obtained. The calculation method of the blood glucose concentration G is as follows: where i 平均 is the average value of the output currents of at least two current acquisition points in the second excitation signal, in nA; S is the slope of the linear equation between i 平均 and the glucose concentration; i n and i j are both output currents in the output current group, in nA; i 差 is the difference between the maximum output current of the excitation signal sequence and the output current of the last acquisition point, in nA; the value range of N is 10 to 53; the value range of J is 10 to 53; X n has a value range of -500 to 500; X j has a value range of -15 to 15; the value range of K is -30 to 0.

2. The calculation method according to claim 1, characterized in that, It also includes a step of applying an alternating voltage to the second working electrode before inputting the first excitation signal to the working electrode to measure the impedance value of blood glucose. According to the output current group and the impedance value, the concentration of blood glucose is obtained, where where, R is the impedance value, Ω; i m is the output current in the output current group, nA; M ranges from 10 to 53; X m ranges from -120 to 120.

3. The calculation method according to claim 2, wherein It also includes a step of obtaining the measured ambient temperature. According to the output current group, the impedance value, and the temperature, the concentration of blood glucose is obtained, where where T is the ambient temperature, in °C; i u is the output current in the output current group, in nA; U ranges from 10 to 53; X u ranges from -7 to 3.

4. The calculation method according to any one of claims 1-3, characterized in that The excitation time of the first excitation signal is 0.1 - 1 s, and the excitation time of the second excitation signal is 0.1 - 2 s; Preferably, the excitation time of the first excitation signal is 0.5 s, and the excitation time of the second excitation signal is 1.25 s.

5. The calculation method according to claim 4, wherein i 平均 It is the average value of the output currents of the last 5 current acquisition points in the second excitation signal.

6. The calculation method according to any one of claims 1-3, characterized in that The voltage value of the first excitation signal is 0.2 - 0.4 V, and the voltage value of the second excitation signal is 0.2 - 0.4 V; Preferably, the voltage values of the first excitation signal and the second excitation signal are both 0.3 V.

7. The calculation method according to claim 6, characterized in that The total application time of the excitation signal sequence is at least 1 s, and the application time of each input signal in the excitation signal sequence is 0.1 - 0.3 s; Preferably, the application time of each input signal in the excitation signal sequence is equal, both being 0.2 s.

8. The calculation method according to claim 6, characterized in that The voltage range of the excitation sequence is 0.1 - 3 V, and the excitation signal sequence includes 4 - 8 consecutive input signals; Preferably, the excitation signal sequence includes 5 consecutive input signals, and the voltage values of the 5 consecutive input signals are 0.3 V, 0.8 V, 1.2 V, 1.7 V, and 2.2 V respectively.

9. The calculation method according to any one of claims 1 to 3, characterized in that, The output current at the current acquisition points of the first excitation signal, the second excitation signal, and the excitation signal sequence is collected every 0.05 s.

10. An analyte sensor for testing a biological sample, characterized in that, The sensor can execute the blood glucose concentration calculation method described in any one of claims 1 - 9.

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