Test strip full absorption judgment method

Abstract

The invention relates to a test strip fullness judgment method which comprises the following steps: after determining that a sample enters a sample introduction channel, continuously applying alternating voltage to a first electrode and a second electrode according to a preset frequency, and obtaining a first mutation electric signal between the first electrode and the second electrode and a second mutation electric signal between the first electrode and the second electrode; according to a difference value between the first mutation electric signal and the second mutation electric signal and a preset threshold value, judging whether the test strip fully sucks the to-be-detected sample or not; according to the method, whether the test strip is full of the to-be-detected sample or not can be effectively judged, so that an electrode for judging whether the sample injection is sufficient or not does not need to be additionally arranged in the test strip of the multi-index electrochemical sensor, and the overhead of an electrode material and the utilization of a test strip space can be effectively saved; the accuracy of the detected concentration of the specific component in the to-be-detected sample can be further improved.

Description

Technical Field

[0001] The present application belongs to the field of electrochemical biosensor technology, and in particular relates to a method for determining whether a test strip is full. Background Art

[0002] Electrochemical sensors have been used to detect or measure the presence of a substance in a fluid sample. Electrochemical sensors are used to detect analytes in samples (e.g., blood or blood products, tears, urine, saliva, or other fluids) and can detect the concentration of specific components in the sample (e.g., blood ketone concentration, blood glucose concentration, and hematocrit, etc.).

[0003] At present, when the dose of the sample to be tested applied to the test strip of the electrochemical sensor is insufficient, that is, when the test strip is not fully filled with the sample to be tested, the concentration of the specific component of the sample to be tested detected by the electrochemical sensor will be inaccurate, or an error will be directly reported and the test result cannot be obtained. Therefore, in many electrochemical sensors, an additional electrode is added to determine whether the sample injection is sufficient. The electrode is generally located at the innermost end of the injection channel in the sensor.

[0004] With the development of market demand, multi-indicator electrochemical sensors have also emerged, which can detect two or more indicators at the same time through one sensor. The test strips of this type of sensor generally have multiple electrodes, and each detection indicator generally requires a corresponding working electrode. At the same time, other electrodes such as hematocrit (HCT) electrodes, reference electrodes or counter electrodes are also required to achieve accurate detection purposes. In this way, multiple electrodes need to be set inside the already narrow test strip, making the test strip's injection channel space very crowded, and there is no extra space to set up electrodes for judging whether the injection is sufficient.

[0005] Therefore, there is still room for improvement for this multi-index electrochemical sensor. Summary of the invention

[0006] The purpose of the present application is to provide a test strip fullness judgment method that can effectively judge whether the test strip has been fully filled with the sample to be tested, so that there is no need to add additional electrodes in the test strip of the multi-index electrochemical sensor for judging whether the sample is sufficiently injected, which can effectively save the cost of electrode materials and the utilization of test strip space, and further improve the accuracy of the concentration of specific components in the sample to be tested.

[0007] The technical solutions provided by this application are as follows: A method for determining whether a test strip is full, the test strip comprising a first electrode, a second electrode and an injection channel, the first electrode comprising a first fork located near an injection port of the injection channel, and a second fork located inside the injection channel, the second electrode being located between the first fork and the second fork, the method comprising: After determining that a sample has entered the injection channel, continuously applying an alternating voltage to the first electrode and the second electrode at a predetermined frequency, and acquiring a first sudden change electrical signal between the first electrode and the second electrode, and a second sudden change electrical signal between the first electrode and the second electrode; Whether the test strip has been fully filled with the sample to be tested is determined based on the difference between the first mutation electrical signal and the second mutation electrical signal and a preset threshold.

[0008] Optionally, judging whether the test strip has been fully filled with the sample to be tested according to the difference between the first mutation electrical signal and the second mutation electrical signal and a preset threshold value includes: It is determined whether the difference between the first mutation electrical signal and the second mutation electrical signal is greater than a preset threshold value. If so, it is determined that the test strip has been fully filled with the sample to be tested. If not, it is determined that the test strip is not fully filled with the sample to be tested.

[0009] Optionally, the preset threshold is determined by the following method: Under each test condition selected from a plurality of different temperatures and a plurality of different hematocrits, applying an AC voltage to the first electrodes and the second electrodes of a plurality of first test strips in an unabsorbed state at a predetermined frequency, and obtaining a first mutation test electrical signal between the first electrodes and the second electrodes of the plurality of first test strips; Under each test condition selected from a plurality of different temperatures and a plurality of different hematocrits, applying an AC voltage to the first electrodes and the second electrodes of a plurality of second test strips in a full absorption state at a predetermined frequency, and obtaining a second mutation test electrical signal between the first electrodes and the second electrodes of the plurality of second test strips; According to the plurality of the first mutation test electrical signals and the plurality of the second mutation test electrical signals corresponding to the respective test conditions, a test difference corresponding to each test condition is obtained, and a test difference set is constructed; A preset threshold is determined according to the test difference value set.

[0010] Optionally, obtaining a test difference corresponding to each test condition according to the plurality of first mutation test electrical signals and the plurality of second mutation test electrical signals corresponding to each test condition, and constructing a test difference set, includes: According to the minimum value among the multiple first mutation test electrical signals corresponding to each test condition and the maximum value among the multiple second mutation test electrical signals, the test difference value corresponding to each test condition is obtained, and a test difference value set is constructed.

[0011] Optionally, determining a preset threshold according to the test difference set includes: The minimum value in the test difference set is used as the preset threshold.

[0012] Optionally, determining a preset threshold according to the test difference set includes: Based on the minimum value in the test difference set, the value is decreased by 10% to 30% to obtain a decreased value, and the decreased value is used as the preset threshold.

[0013] Optionally, the decreasing of the minimum value in the test difference set by 10% to 30% to obtain a decreased value, and using the decreased value as a preset threshold, comprises: The minimum value in the test difference set is decreased by 20% to obtain a decreased value, and the decreased value is used as the preset threshold.

[0014] Optionally, the step of decreasing the minimum value in the test difference set by 20% to obtain a decreased value, and using the decreased value as a preset threshold, comprises: Based on the minimum value in the test difference set, the value is decreased by 20% and rounded to obtain a decreased and rounded value, and the decreased and rounded value is used as the preset threshold.

[0015] Optionally, the test strip further comprises: a third electrode and a fourth electrode located between the first bifurcation and the second bifurcation, wherein the first bifurcation is a first detection index working electrode, and the second bifurcation is a sample suction judgment electrode; The second electrode, the third electrode and the fourth electrode respectively serve as any one of the HCT and background electrode, the reference electrode and the second detection index working electrode exclusively.

[0016] Optionally, The second electrode is an electrode between the first fork and the second fork and closest to the second fork.

[0017] Compared with the prior art, the present application provides a method for judging whether a test strip is full, wherein the test strip comprises a first electrode, a second electrode and an injection channel, wherein the first electrode comprises a first fork located at an injection port close to the injection channel, and a second fork located closer to the inside of the injection channel, and the second electrode is located between the first fork and the second fork. After determining that a sample has entered the injection channel, an AC voltage is continuously applied to the first electrode and the second electrode at a predetermined frequency, and a first mutation electrical signal between the first electrode and the second electrode and a second mutation electrical signal between the first electrode and the second electrode are obtained, and then, based on the difference between the first mutation electrical signal and the second mutation electrical signal and a preset threshold, it is judged whether the test strip is full of the sample to be tested. In the present application, the above method can effectively judge whether the test strip is full of the sample to be tested, so that there is no need to add an additional electrode for judging whether the injection is sufficient in the test strip of the multi-index electrochemical sensor, which can effectively save the cost of electrode materials and the utilization of the test strip space, and further effectively improve the accuracy of the concentration of specific components in the detected sample to be tested. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic diagram of a flow chart of a method for determining whether a test strip is full of liquid disclosed in an embodiment of the present application; Figure 2 A first structural schematic diagram of a test strip disclosed in an embodiment of the present application; Figure 3 This is a second structural schematic diagram of a test strip disclosed in an embodiment of the present application. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0021] It should be noted that when an element is referred to as being "fixed on" or "set on" another element, it can be directly on the other element or indirectly set on the other element; when an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0022] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0023] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "multiple" and "several" mean two or more, unless otherwise clearly and specifically defined.

[0024] It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions under which this application can be implemented. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in this application without affecting the effects and purposes that can be achieved by this application.

[0025] like Figure 1 As shown, this embodiment provides a method for determining whether a test strip is full. Figure 2 As shown, the test strip includes a first electrode 10, a second electrode 20 and an injection channel 30, the first electrode 10 includes a first fork 11 located at an injection port 31 near the injection channel 30, and a second fork 12 located inside the injection channel 30, and the second electrode 20 is located between the first fork 11 and the second fork 12, and the method includes: S11, after determining that a sample has entered the injection channel, continuously applying an AC voltage to the first electrode and the second electrode at a predetermined frequency, and obtaining a first sudden change electrical signal between the first electrode and the second electrode, and a second sudden change electrical signal between the first electrode and the second electrode; In this embodiment, the predetermined frequency can be 10KHz-50KHz, and the preferred predetermined frequency is 10KHz. The first mutation electrical signal and the second mutation electrical signal can be impedance values ​​or current values. Preferably, the first mutation electrical signal and the second mutation electrical signal are impedance values; preferably, the distance between the second fork and the second electrode is smaller than the distance between the first fork and the second electrode, and more preferably, the distance between the second fork and the second electrode is much smaller than the distance between the first fork and the second electrode.

[0026] In this embodiment, according to the situation that the sample covers the electrode after the sample is applied to the injection channel, it is divided into three stages, as follows: The first stage: After the sample enters the injection channel from the injection port, the sample will cover the first fork. At this time, since there is no sample on the second electrode, the circuit between the first electrode and the second electrode is disconnected, and the impedance between the first electrode and the second electrode is equivalent to infinity; The second stage: as the sample flows into the injection channel, the sample covers the second electrode. At this time, the second electrode and the first bifurcation are connected through the sample, and the impedance between the first electrode and the second electrode changes suddenly from infinity to the first impedance Z1 between the second electrode and the first bifurcation, that is, the first sudden electrical signal; The third stage: as the sample continues to flow into the injection channel, the sample will contact or cover the second bifurcation. At this time, the second electrode is respectively connected to the first bifurcation and the second bifurcation through the sample, forming a parallel circuit between the first electrode and the second electrode. At this time, the impedance between the second electrode and the first bifurcation is the first impedance Z1, and the impedance between the second electrode and the second bifurcation is the third impedance Z3. At this time, the impedance between the first electrode and the second electrode obtained suddenly changes from the first impedance Z1 (i.e., the first mutation electrical signal) to the second impedance Z2 (i.e., the second mutation electrical signal) after Z1 and Z3 are connected in parallel. Since the total impedance after the impedances are connected in parallel is smaller than any impedance value in the parallel circuit, that is, Z2 is smaller than Z1 and Z3, the second mutation electrical signal is smaller than the first mutation electrical signal. Furthermore, if the distance between the second bifurcation and the second electrode is much smaller than the distance between the first bifurcation and the second electrode, the third impedance Z3 between the second bifurcation and the second electrode will be much smaller than the first impedance Z1 between the first bifurcation and the second electrode, and then the second impedance Z2 will be much smaller than the first impedance Z1, that is, the second mutation electrical signal is much smaller than the first mutation electrical signal.

[0027] S12. Determine whether the test strip is full of the sample to be tested based on the difference between the first mutation electrical signal and the second mutation electrical signal and a preset threshold value.

[0028] In this embodiment, the sample can be a blood sample, or a body fluid sample such as tears, urine and saliva, or a non-body fluid sample. The preferred sample is a blood sample, and the preset threshold is a pre-set threshold. When the test strip is in a full state, the second mutation electrical signal obtained is smaller than the first mutation electrical signal, and further, the second mutation electrical signal obtained is much smaller than the first mutation electrical signal, and when the test strip is not full, the second mutation electrical signal obtained is only slightly smaller than the first mutation electrical signal. Therefore, the difference between the first mutation electrical signal and the second mutation electrical signal can be compared with the preset threshold, and whether the test strip is full of the sample to be tested can be judged according to the comparison result.

[0029] Compared with the prior art, the present application provides a method for judging whether a test strip is full, wherein the test strip comprises a first electrode, a second electrode and an injection channel, wherein the first electrode comprises a first fork located at an injection port close to the injection channel, and a second fork located closer to the inside of the injection channel, and the second electrode is located between the first fork and the second fork. After determining that a sample has entered the injection channel, an AC voltage is continuously applied to the first electrode and the second electrode at a predetermined frequency, and a first mutation electrical signal between the first electrode and the second electrode and a second mutation electrical signal between the first electrode and the second electrode are obtained, and then, based on the difference between the first mutation electrical signal and the second mutation electrical signal and a preset threshold, it is judged whether the test strip is full of the sample to be tested. The present application can effectively judge whether the test strip is full of the sample to be tested through the above method, so that there is no need to add an additional electrode for judging whether the injection is sufficient in the test strip of the multi-index electrochemical sensor, which can effectively save the cost of electrode materials and the utilization of the test strip space, and further improve the accuracy of the concentration of specific components in the detected sample to be tested.

[0030] As an implementation mode, in the embodiment of the present application, judging whether the test strip has been fully filled with the sample to be tested according to the difference between the first mutation electrical signal and the second mutation electrical signal and a preset threshold value includes: It is determined whether the difference between the first mutation electrical signal and the second mutation electrical signal is greater than a preset threshold value. If so, it is determined that the test strip has been fully aspirated with the sample to be tested. If not, it is determined that the test strip has not been fully aspirated with the sample to be tested.

[0031] In this embodiment, it is determined whether the difference between the first mutation electrical signal and the second mutation electrical signal is greater than a preset threshold value. If the difference between the first mutation electrical signal and the second mutation electrical signal is greater than the preset threshold value, it is determined that the test strip has been fully absorbed by the sample to be tested. If the difference between the first mutation electrical signal and the second mutation electrical signal is less than or equal to the preset threshold value, it is determined that the test strip is not fully absorbed by the sample to be tested.

[0032] As an implementation manner, in the embodiment of the present application, the preset threshold is determined by the following method: S21, under each test condition consisting of one of a plurality of different temperatures and a plurality of different hematocrits, applying an AC voltage to the first electrodes and the second electrodes of a plurality of first test strips in an unabsorbed state at a predetermined frequency, and obtaining a first mutation test electrical signal between the first electrodes and the second electrodes of the plurality of first test strips; In this embodiment, the first test strip is Figure 2 The test strips used for testing have the same test strip structure as in the test strips, multiple different temperatures, which may include two extreme values ​​of 5°C and 45°C, and may also include other more temperature values, multiple different hematocrits, which may include two extreme values ​​of 10% HCT and 70% HCT, and may also include other more hematocrit values.

[0033] In this embodiment, a plurality of first test strips are prepared according to the number of test conditions and the number of tests for each test condition, a test condition consisting of a temperature from a plurality of different temperatures and a hematocrit from a plurality of different hematocrits is selected as the current test condition, and under the current test condition, a first test strip is selected as the current test strip, so that the first test strip is in a non-full state, an AC voltage is applied to the first electrode and the second electrode of the first test strip at a predetermined frequency, and a first mutation test electrical signal between the first electrode and the second electrode of the first test strip is obtained, and in this way, a total of multiple tests are performed to obtain the first mutation test electrical signals between the first electrode and the second electrode of the plurality of first test strips corresponding to the current test condition, and in this way, the first mutation test electrical signals between the first electrode and the second electrode of the plurality of first test strips in the non-full state corresponding to each test condition are obtained.

[0034] Specifically, according to the extreme test temperature of 5°C and 45°C, combined with the extreme hematocrit HCT10% and HCT70% to form four test conditions, each test condition needs to be tested 5 times, 20 first test strips can be prepared, and the test condition of 5°C, hematocrit HCT10% and HCT70% are selected from the temperature of 5°C and 45°C as the current test condition. Under the test conditions of temperature 5°C and hematocrit 10% HCT, a first test strip is selected as the current test strip, and the first test strip is in an unabsorbed state, and the first test strip is pressed at 10KH An AC voltage is applied to the first electrode and the second electrode of the first test strip at a frequency of z, and a first mutation test electrical signal between the first electrode and the second electrode of the first test strip in an incompletely filled state is obtained. Then, in this way, a total of 5 tests are performed to obtain the first mutation test electrical signals between the first electrode and the second electrode of 5 first test strips corresponding to the test conditions of a temperature of 5°C and a hematocrit of 10% HCT. In this way, the first mutation test electrical signals between the first electrode and the second electrode of 5 first test strips corresponding to each of the 4 test conditions are obtained. The test results are shown in Table 1 below: Table 1 Test conditions and the five first mutation test electrical signals corresponding to each test condition

[0035] Wherein, Z1 is the first mutation test electrical signal, and specifically, Z1 is the first test impedance value.

[0036] S22, under each test condition consisting of one of a plurality of different temperatures and a plurality of different hematocrits, applying an AC voltage to the first electrodes and the second electrodes of the plurality of second test strips in a full absorption state at a predetermined frequency, and obtaining a second mutation test electrical signal between the first electrodes and the second electrodes of the plurality of second test strips; In this embodiment, the second test strip is Figure 2 The test strips used for testing have the same test strip structure as in the test strips, multiple different temperatures, which may include two extreme values ​​of 5°C and 45°C, and may also include other more temperature values, multiple different hematocrits, which may include two extreme values ​​of 10% HCT and 70% HCT, and may also include other more hematocrit values.

[0037] In this embodiment, a plurality of second test strips are prepared according to the number of test conditions and the number of tests for each test condition, a test condition consisting of a temperature from a plurality of different temperatures and a hematocrit from a plurality of different hematocrits is selected as the current test condition, and under the current test condition, a second test strip is selected as the current test strip, the second test strip is placed in a full absorption state, an AC voltage is applied to the first electrode and the second electrode of the second test strip at a predetermined frequency, and a second mutation test electrical signal between the first electrode and the second electrode of the second test strip is obtained, in this way, a total of multiple tests are performed to obtain second mutation test electrical signals between the first electrode and the second electrode of the plurality of second test strips corresponding to the current test condition, and in this way, the second mutation test electrical signals between the first electrode and the second electrode of the plurality of second test strips corresponding to each test condition are obtained.

[0038] Specifically, according to the extreme test temperature of 5°C and 45°C, combined with the extreme hematocrit HCT10% and HCT70% to form four test conditions, each test condition needs to be tested 5 times, 20 second test strips can be prepared, and the test condition of 5°C, hematocrit HCT10% and HCT70% are selected from the temperature of 5°C and 45°C as the current test condition. Under the test conditions of temperature 5°C and hematocrit 10% HCT, a second test strip is selected as the current test strip, and the second test strip is in a full absorption state, and the pressure is adjusted by 10K. An AC voltage is applied to the first electrode and the second electrode of the second test strip at a frequency of Hz, and a second mutation test electrical signal between the first electrode and the second electrode of the second test strip in an incompletely aspirated state is obtained. In this way, a total of 5 tests are performed to obtain the second mutation test electrical signals between the first electrode and the second electrode of 5 second test strips corresponding to the test conditions of a temperature of 5°C and a hematocrit of 10% HCT. In this way, the second mutation test electrical signals between the first electrode and the second electrode of 5 second test strips corresponding to each of the 4 test conditions are obtained. The test results are shown in Table 2 below: Table 2 Test conditions and the five second mutation test electrical signals corresponding to each test condition

[0039] Wherein, Z2 is the second mutation test electrical signal, and specifically, Z2 is the second test impedance value.

[0040] S23, obtaining a test difference corresponding to each test condition according to a plurality of first mutation test electrical signals and a plurality of second mutation test electrical signals corresponding to each test condition, and constructing a test difference set; In this embodiment, the test difference corresponding to each test condition can be obtained based on a suitable first mutation test electrical signal among multiple first mutation test electrical signals and a suitable second mutation test electrical signal among multiple second mutation test electrical signals corresponding to the test condition. In this way, the test difference corresponding to each of the multiple test conditions is obtained, and a test difference set is constructed based on the multiple test differences.

[0041] The test difference value corresponding to each test condition can be obtained based on the minimum value among the multiple first mutation test electrical signals and the maximum value among the multiple second mutation test electrical signals corresponding to each test condition, or the test difference value corresponding to the test condition can be obtained based on the second minimum value among the multiple first mutation test electrical signals and the second maximum value among the multiple second mutation test electrical signals corresponding to each test condition.

[0042] S24. Determine a preset threshold value according to the test difference set.

[0043] In this embodiment, one of the multiple test differences in the test difference set can be used as the preset threshold, the minimum value among the multiple test differences in the test difference set can be used as the preset threshold, or the second smallest value among the multiple test differences in the test difference set can be used as the preset threshold.

[0044] As an implementation mode, in the embodiment of the present application, according to the multiple first mutation test electrical signals and the multiple second mutation test electrical signals corresponding to the respective test conditions, the test difference corresponding to the respective test conditions is obtained, and a test difference set is constructed, including: According to the minimum value among the multiple first mutation test electrical signals and the maximum value among the multiple second mutation test electrical signals corresponding to the respective test conditions, the test difference value corresponding to the respective test conditions is obtained, and a test difference value set is constructed.

[0045] In this embodiment, the minimum value among multiple first mutation test electrical signals and the maximum value among multiple second mutation test electrical signals corresponding to a test condition can be subtracted to obtain the test difference corresponding to the test condition. In this way, the test difference corresponding to each of the multiple test conditions is obtained, and a test difference set is constructed based on the multiple test differences.

[0046] Specifically, according to the data in Table 1 and Table 2, the minimum value of 2788.76 among the five first test impedance values ​​corresponding to the test condition of temperature 5°C and hematocrit 10% and the maximum value of 1355.24 among the five second test impedance values ​​can be subtracted to obtain a test difference value of 1433.52 corresponding to the test condition of temperature 5°C and hematocrit 10%. In this way, a test difference value of 6418.14 corresponding to the test condition of temperature 5°C and hematocrit 70% is obtained, a test difference value of 974.86 corresponding to the test condition of temperature 45°C and hematocrit 10% is obtained, and a test difference value of 3745.16 corresponding to the test condition of temperature 45°C and hematocrit 70% is obtained. Based on the four test differences, a test difference value set including 1433.52, 6418.14, 974.86, and 3745.16 is constructed.

[0047] As an implementation manner, in the embodiment of the present application, determining a preset threshold value according to a test difference set includes: The minimum value in the test difference set is used as the preset threshold.

[0048] In this embodiment, by using the minimum value in the test difference value set constructed by the test difference values ​​corresponding to a plurality of test conditions as the preset threshold value, the accuracy of the sample aspiration judgment under various temperature and hematocrit conditions can be effectively guaranteed.

[0049] Specifically, the minimum value in the test difference set is 974.86, and 974.86 can be used as the preset threshold.

[0050] As an implementation manner, in the embodiment of the present application, determining a preset threshold value according to the test difference set includes: Based on the minimum value in the test difference set, it is decreased by 10% to 30% to obtain a decreased value, and the decreased value is used as the preset threshold.

[0051] In this embodiment, taking into account the inevitable batch differences between samples and test strips, and in order to ensure that the system design has sufficient redundancy to meet the needs of instrument identification and judgment, the minimum value among multiple test differences can be reduced by 10-30%, preferably by 20%, to obtain a reduced value, and the reduced value is used as the preset threshold to reduce the batch differences between samples and test strips and the judgment error caused by system design.

[0052] As an implementation mode, in the embodiment of the present application, based on the minimum value in the test difference set, the value after the decrease is decreased by 10% to 30%, and the value after the decrease is used as the preset threshold, including: Based on the minimum value in the test difference set, it is decreased by 20% to obtain a decreased value, and the decreased value is used as the preset threshold.

[0053] Specifically, the minimum value of 974.86 in the test difference set can be reduced by 20% to obtain a reduced value of 779.89.

[0054] As an implementation mode, in the embodiment of the present application, based on the minimum value in the test difference set, the value after the decrease is reduced by 20%, and the value after the decrease is used as the preset threshold, including: Based on the minimum value in the test difference set, the value is decreased by 20% and rounded to the integer, and the decreased and rounded value is used as the preset threshold.

[0055] In this embodiment, in order to reduce the instrument cost, the minimum value in the test difference set can be reduced by 20% and rounded to obtain the reduced and rounded value, and the reduced and rounded value can be used as the preset threshold. It can be rounded to ten, and further, it can be rounded to one hundred.

[0056] Specifically, the minimum value 974.86 in the test difference set is reduced by 20% to obtain a reduced value of 779.89, which can be rounded to 780. Furthermore, the value can be rounded to 800, and the value 800 can be used as the preset threshold.

[0057] In the embodiment of the present application, an experiment is designed to verify the electrode structure for judging full absorption and the method for judging full absorption of samples. Specifically, the experiment is carried out under two extreme test temperatures (5°C and 45°C) and seven sample conditions with different hematocrits (HCT10%, HCT20%, HCT30%, HCT40%, HCT50%, HCT60%, HCT70%), that is, a total of 14 verification test conditions, 5 tests are carried out under each verification test condition, including 3 samples fully absorbed (S3-S5, S8-S10) and 2 samples not fully absorbed (S1-S2, S6-S7), the frequency of the AC voltage is also 10KHz, and the first verification test impedance between the second electrode and the first bifurcation of each first verification test strip in the verification test, and the second verification test impedance between the second electrode and the second bifurcation of each second verification test strip are recorded. The judgment result obtained by comparing the difference between the first verification test impedance and the second verification test impedance under the same verification test condition with the preset threshold value is used to verify whether it is consistent with the actual full absorption of the sample. The data of the verification test are shown in Table 3 below: Table 3 Samples fully aspirated (S3-S5, S8-S10) and samples not fully aspirated (S1-S2, S6-S7) and the corresponding judgment results obtained based on the test data

[0058] Among them, Z1 in Table 3 is the first verification test impedance, Z2 is the second verification test impedance, S3-S5, S8-S10 are actually fully absorbed samples, and S1-S2, S6-S7 are actually not fully absorbed samples. According to the data in Table 3, the judgment results of samples S3-S5, S8-S10 obtained by comparing the difference Z1-Z2 between the first verification test impedance Z1 and the second verification test impedance Z2 with the preset threshold value 800 are also fully absorbed, and the judgment results of samples S1-S2, S6-S7 obtained by comparing the difference Z1-Z2 between the first verification test impedance Z1 and the second verification test impedance Z2 with the preset threshold value 800 are also not fully absorbed. It can be seen that the full absorption judgment electrode structure and the sample full absorption judgment method are verified by the experimental data to be very feasible, and the judgment accuracy of the sample full absorption judgment method is very high.

[0059] like Figure 3 As shown, as an implementation mode, in the embodiment of the present application, the test strip further includes: a third electrode 40 and a fourth electrode 50 located between the first fork 11 and the second fork 12, wherein the first fork 11 is a first detection indicator working electrode, and the second fork 12 is a sample suction judgment electrode; the second electrode 20, the third electrode 40 and the fourth electrode 50 respectively serve as any one of the HCT and background electrode, the reference electrode, and the second detection indicator working electrode.

[0060] In the present embodiment, the second electrode may be HCT and background electrode, the third electrode may be reference electrode, and the fourth electrode may be second detection index working electrode, or the second electrode may be HCT and background electrode, the third electrode may be second detection index working electrode, and the fourth electrode may be reference electrode, or the second electrode may be reference electrode, the third electrode may be HCT and background electrode, and the fourth electrode may be second detection index working electrode, or the second electrode may be reference electrode, the third electrode may be second detection index working electrode, and the fourth electrode may be HCT and background electrode, or the second electrode may be second detection index working electrode, the third electrode may be reference electrode, and the fourth electrode may be HCT and background electrode, or the second electrode may be second detection index working electrode, the third electrode may be HCT and background electrode, and the fourth electrode may be reference electrode. Further, the second electrode, the third electrode, and the fourth electrode may be second detection index working electrode, the third detection index working electrode, and the fourth detection index working electrode, wherein one or two electrodes may be functionally defined as multiplexed electrodes, such as HCT electrode, background electrode, or reference electrode, by instrument software.

[0061] Specifically, the sample to be tested is a blood sample, and the detection index corresponding to each working electrode can be selected from the following indicators: blood glucose, uric acid, blood ketone, creatinine, lactic acid, hemoglobin, glycosylated hemoglobin, cholesterol, lipoprotein, triglyceride and other common electrochemical detection indicators.

[0062] Taking the common blood glucose and blood ketone dual-indicator electrochemical test strip as an example, the indicator detection process is briefly described. The working electrode is coated with a corresponding reaction reagent. For example, the blood ketone working electrode can be coated with a corresponding enzyme reagent, and the blood glucose working electrode is coated with a corresponding enzyme reagent. When the HCT and background electrodes are used as HCT electrodes, an AC excitation voltage of a preset frequency is applied between the HCT electrode and the reference electrode to obtain the impedance signal of the blood sample between the HCT electrode and the reference electrode, and the impedance signal is substituted into a preset linear equation to obtain the hematocrit of the blood sample, i.e., HCT, wherein the preset frequency is a pre-set frequency, and the preset linear equation is an equation fitted according to the test results. When the HCT and background electrodes are used as background electrodes, a weak DC excitation voltage is applied between the background electrode and the reference electrode, and a weak current signal can be measured on the background electrode, i.e., the background current signal of the sample. The size of the background current signal It can reflect the purity of the blood sample. A weak DC excitation voltage is applied between the blood ketone working electrode and the reference electrode. A current signal that decreases with the passage of time can be detected on the blood ketone working electrode. The current intensity is in the nanoampere to microampere level. This current signal is proportional to the blood ketone concentration in the blood. The current signal detected on the blood ketone working electrode can be subjected to data compensation and correction processing according to the background current signal to obtain a corrected current signal representing the blood ketone concentration of the blood to be tested. A weak DC excitation voltage is applied between the blood glucose working electrode and the reference electrode. A current signal that decreases with the passage of time can be detected on the blood glucose working electrode. The current intensity is in the nanoampere to microampere level. This current signal is proportional to the blood glucose concentration in the blood. The current signal detected on the blood glucose working electrode can be subjected to data compensation and correction processing according to the background current signal to obtain a corrected current signal representing the blood glucose concentration of the blood to be tested.

[0063] like Figure 3 As shown, as an implementation manner, in the embodiment of the present application, the second electrode 20 is an electrode between the first fork 11 and the second fork 12 and closest to the second fork 12 .

[0064] In this embodiment, by using the electrode between the first fork 11 and the second fork 12 closest to the second fork 12 as the second electrode 20, the difference between the acquired first electrical signal and the second electrical signal can be larger, making the result of the sample suction judgment more accurate.

[0065] Specifically, the second electrode 20 closest to the second bifurcation 12 is the blood glucose working electrode, the third electrode 40 is close to the second electrode 20, the third electrode 40 is the reference electrode, the fourth electrode 50 is between the third electrode 40 and the first bifurcation 11 of the first electrode 10, and the fourth electrode 50 is the HCT and background electrode.

[0066] The embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referenced to each other.

[0067] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for determining whether a test strip is full, characterized in that: The test strip comprises a first electrode, a second electrode and an injection channel, the first electrode comprises a first fork located near an injection port of the injection channel, and a second fork located inside the injection channel, the second electrode is located between the first fork and the second fork, and the method comprises: After determining that a sample has entered the injection channel, continuously applying an alternating voltage to the first electrode and the second electrode at a predetermined frequency, and acquiring a first sudden change electrical signal between the first electrode and the second electrode, and a second sudden change electrical signal between the first electrode and the second electrode; Whether the test strip has been fully filled with the sample to be tested is determined based on the difference between the first mutation electrical signal and the second mutation electrical signal and a preset threshold.

2. The method according to claim 1, characterized in that The step of judging whether the test strip is full of the sample to be tested according to the difference between the first mutation electrical signal and the second mutation electrical signal and a preset threshold value comprises: It is determined whether the difference between the first mutation electrical signal and the second mutation electrical signal is greater than a preset threshold value. If so, it is determined that the test strip has been fully filled with the sample to be tested. If not, it is determined that the test strip is not fully filled with the sample to be tested.

3. The method according to claim 2, characterized in that The preset threshold is determined by the following method: Under each test condition selected from a plurality of different temperatures and a plurality of different hematocrits, applying an AC voltage to the first electrodes and the second electrodes of a plurality of first test strips in an unabsorbed state at a predetermined frequency, and obtaining a first mutation test electrical signal between the first electrodes and the second electrodes of the plurality of first test strips; Under each test condition selected from a plurality of different temperatures and a plurality of different hematocrits, applying an AC voltage to the first electrodes and the second electrodes of a plurality of second test strips in a full absorption state at a predetermined frequency, and obtaining a second mutation test electrical signal between the first electrodes and the second electrodes of the plurality of second test strips; According to the plurality of the first mutation test electrical signals and the plurality of the second mutation test electrical signals corresponding to the respective test conditions, a test difference corresponding to each test condition is obtained, and a test difference set is constructed; A preset threshold is determined according to the test difference value set.

4. The method according to claim 3, characterized in that The step of obtaining a test difference value corresponding to each test condition according to the plurality of first mutation test electrical signals and the plurality of second mutation test electrical signals corresponding to each test condition, and constructing a test difference value set, comprises: According to the minimum value among the multiple first mutation test electrical signals corresponding to each test condition and the maximum value among the multiple second mutation test electrical signals, the test difference value corresponding to each test condition is obtained, and a test difference value set is constructed.

5. The method according to claim 4, characterized in that The step of determining a preset threshold value according to the test difference value set includes: The minimum value in the test difference set is used as the preset threshold.

6. The method according to claim 4, characterized in that The step of determining a preset threshold value according to the test difference value set includes: Based on the minimum value in the test difference set, the value is decreased by 10% to 30% to obtain a decreased value, and the decreased value is used as the preset threshold.

7. The method according to claim 6, characterized in that The step of decreasing the minimum value in the test difference set by 10% to 30% to obtain a decreased value, and using the decreased value as a preset threshold, comprises: The minimum value in the test difference set is decreased by 20% to obtain a decreased value, and the decreased value is used as the preset threshold.

8. The method according to claim 7, characterized in that The step of decreasing the minimum value in the test difference set by 20% to obtain a decreased value, and using the decreased value as a preset threshold, comprises: Based on the minimum value in the test difference set, the value is decreased by 20% and rounded to obtain a decreased and rounded value, and the decreased and rounded value is used as the preset threshold.

9. The method according to any one of claims 1 to 8, characterized in that: The test strip further comprises: a third electrode and a fourth electrode located between the first bifurcation and the second bifurcation, wherein the first bifurcation is a first detection index working electrode, and the second bifurcation is a sample suction judgment electrode; The second electrode, the third electrode and the fourth electrode respectively serve as any one of the HCT and background electrode, the reference electrode and the second detection index working electrode exclusively.

10. The method according to claim 9, characterized in that The second electrode is an electrode between the first fork and the second fork and closest to the second fork.

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