A method for judging that a test strip is fully saturated

Abstract

The present application relates to a method for judging whether a test strip is fully filled. After it is determined that a sample enters the sampling channel, an alternating 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. Then, according to 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 has been fully filled with the sample to be measured. Through the above method, the present application can effectively judge whether the test strip has been fully filled with the sample to be measured, so that there is no need to additionally add an electrode for judging whether the sampling 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 the specific component in the sample to be measured detected.

Description

Technical Field

[0001] This application belongs to the technical field of electrochemical biosensing, and particularly relates to a method for judging whether a test strip is fully filled. Background Art

[0002] Electrochemical sensors have always been used to detect or measure the presence of a certain substance in a fluid sample. By using an electrochemical sensor to detect an analyte in a sample (such as blood or blood-derived products, tears, urine, saliva, or other liquids), the concentration of a specific component in the sample (such as blood ketone concentration, blood glucose concentration, and hematocrit, etc.) can be detected.

[0003] Currently, when the dose of the sample to be tested applied to the test strip of an electrochemical sensor is insufficient, that is, when the test strip is not fully filled with the sample to be tested, it will cause the concentration of the specific component of the sample to be tested detected by the electrochemical sensor to be inaccurate, or directly report an error and unable to obtain a test result. Therefore, an additional electrode for judging whether the sample injection is sufficient is added to many electrochemical sensors, and this electrode is generally located at the innermost end of the sample injection channel in the sensor.

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

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

[0006] The purpose of this application is to provide a method for judging whether a test strip is fully filled, which can effectively judge whether the test strip is fully filled with the sample to be tested, so that it is not necessary to additionally add an electrode for judging whether the sample injection is sufficient inside the test strip of the multi-index electrochemical sensor, 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 the specific component in the sample to be tested detected.

[0007] The technical solution provided by this application is as follows:

[0008] A method for judging whether a test strip is full of liquid. The test strip includes a first electrode, a second electrode, and a sample injection channel. The first electrode includes a first bifurcation near the sample injection port of the sample injection channel and a second bifurcation inside the sample injection channel. The second electrode is located between the first bifurcation and the second bifurcation. The method includes:

[0009] After determining that a sample has entered the sample injection channel, an alternating voltage is continuously applied to the first electrode and the second electrode at a predetermined frequency, and a first mutant electrical signal between the first electrode and the second electrode, and a second mutant electrical signal between the first electrode and the second electrode are acquired;

[0010] Based on the difference between the first mutant electrical signal and the second mutant electrical signal and a preset threshold, it is judged whether the test strip is full of the sample to be tested.

[0011] Optionally, the judging whether the test strip is full of the sample to be tested based on the difference between the first mutant electrical signal and the second mutant electrical signal and the preset threshold includes:

[0012] Judge whether the difference between the first mutant electrical signal and the second mutant electrical signal is greater than the preset threshold. If so, it is determined that the test strip is full of the sample to be tested; if not, it is determined that the test strip is not full of the sample to be tested.

[0013] Optionally, the preset threshold is determined by the following method:

[0014] Under each of various test conditions formed by arbitrarily selecting one from multiple different temperatures and multiple different hematocrits, an alternating voltage is applied to the first electrode and the second electrode of multiple first test strips in an unfilled state at a predetermined frequency, and a first mutant test electrical signal between the first electrode and the second electrode of the multiple first test strips is acquired;

[0015] Under each of various test conditions formed by arbitrarily selecting one from multiple different temperatures and multiple different hematocrits, an alternating voltage is applied to the first electrode and the second electrode of multiple second test strips in a filled state at a predetermined frequency, and a second mutant test electrical signal between the first electrode and the second electrode of the multiple second test strips is acquired;

[0016] Based on the multiple first mutant test electrical signals and the multiple second mutant test electrical signals corresponding to each test condition, test differences corresponding to each test condition are obtained, and a test difference set is constructed;

[0017] Based on the test difference set, the preset threshold is determined.

[0018] Optionally, obtaining a test difference corresponding to each test condition from the multiple first mutant test electrical signals and the multiple second mutant test electrical signals corresponding to each test condition, and constructing a test difference set, including:

[0019] Obtaining a test difference corresponding to each test condition from the minimum value among the multiple first mutant test electrical signals and the maximum value among the multiple second mutant test electrical signals corresponding to each test condition, and constructing a test difference set.

[0020] Optionally, determining a preset threshold according to the test difference set, including:

[0021] Taking the minimum value in the test difference set as the preset threshold.

[0022] Optionally, determining a preset threshold according to the test difference set, including:

[0023] Based on the minimum value in the test difference set, decreasing it by 10% to 30% to obtain a decreased value, and taking the decreased value as the preset threshold.

[0024] Optionally, the operation of, based on the minimum value in the test difference set, decreasing it by 10% to 30% to obtain a decreased value, and taking the decreased value as the preset threshold, includes:

[0025] Based on the minimum value in the test difference set, decreasing it by 20% to obtain a decreased value, and taking the decreased value as the preset threshold.

[0026] Optionally, the operation of, based on the minimum value in the test difference set, decreasing it by 20% to obtain a decreased value, and taking the decreased value as the preset threshold, includes:

[0027] Based on the minimum value in the test difference set, decreasing it by 20% and rounding down to obtain a decreased and rounded-down value, and taking the decreased and rounded-down value as the preset threshold.

[0028] Optionally, the test strip further includes: a third electrode and a fourth electrode located between the first fork and the second fork, wherein the first fork is a working electrode for the first detection index, and the second fork is a sampling judgment electrode;

[0029] The second electrode, the third electrode, and the fourth electrode respectively serve as any one of the exclusive HCT and background electrode, reference electrode, and working electrode for the second detection index.

[0030] Optionally,

[0031] The second electrode is the electrode closest to the second bifurcation between the first bifurcation and the second bifurcation.

[0032] Compared with the prior art, a method for judging whether a test strip is full is provided in the present application. The test strip includes a first electrode, a second electrode, and a sampling channel. The first electrode includes a first bifurcation located at the sampling port near the sampling channel, and a second bifurcation located inside the sampling channel. The second electrode is located between the first bifurcation and the second bifurcation. After it is determined that a sample enters the sampling channel, an alternating 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. Then, according to 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 has been filled with the sample to be measured. By the above method in the present application, it is possible to effectively judge whether the test strip has been filled with the sample to be measured, so that there is no need to additionally add an electrode for judging whether the sampling 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 the specific component in the sample to be measured detected. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0034] Figure 1 It is a schematic flow chart of a method for judging whether a test strip is full disclosed in an embodiment of the present application;

[0035] Figure 2 It is a first structural schematic diagram of a test strip disclosed in an embodiment of the present application;

[0036] Figure 3 It is a second structural schematic diagram of a test strip disclosed in an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0038] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly disposed 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.

[0039] It should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying 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 construed as a limitation to the present application.

[0040] In addition, the terms "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, the meaning of "a plurality of" and "several" is two or more, unless otherwise specifically defined.

[0041] It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those skilled in the art to understand and read, and are not used to limit the implementation conditions of the present application. Therefore, they do not have a substantial technical meaning. Any modification of the structure, change of the ratio relationship, or adjustment of the size, without affecting the effects that the present application can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present application.

[0042] As Figure 1 shown, this embodiment provides a method for judging whether a test strip is full. As Figure 2 shown, the test strip includes a first electrode 10, a second electrode 20, and a sampling channel 30. The first electrode 10 includes a first bifurcation 11 located at the sampling port 31 near the sampling channel 30, and a second bifurcation 12 located inside the sampling channel 30. The second electrode 20 is located between the first bifurcation 11 and the second bifurcation 12. The method includes:

[0043] S11. After determining that a sample has entered the sampling channel, apply an alternating voltage to the first electrode and the second electrode continuously at a predetermined frequency, and obtain 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;

[0044] In this embodiment, the predetermined frequency may be 10 KHz - 50 KHz, preferably the predetermined frequency is 10 KHz. The first mutant electrical signal and the second mutant electrical signal may be impedance values or current values, preferably the first mutant electrical signal and the second mutant electrical signal are impedance values; preferably, the distance between the second bifurcation and the second electrode is less than the distance between the first bifurcation and the second electrode, and more preferably, the distance between the second bifurcation and the second electrode is much less than the distance between the first bifurcation and the second electrode.

[0045] In this embodiment, according to the situation of the sample covering the electrode after the sample is applied to the injection channel, it is divided into three stages, which are specifically as follows:

[0046] The first stage: After the sample enters the injection channel from the injection port, the sample will cover the first bifurcation. At this time, since there is no sample on the second electrode, the circuit between the first electrode and the second electrode is open, and the impedance between the first electrode and the second electrode is equivalent to infinity;

[0047] The second stage: As the sample flows into the injection channel, the sample will cover the second electrode. At this time, the second electrode and the first bifurcation are conducted through the sample, and the impedance between the first electrode and the second electrode obtained changes from infinity to the first impedance Z1 between the second electrode and the first bifurcation, that is, the first mutant electrical signal;

[0048] 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 conducted with the first bifurcation and the second bifurcation through the sample, and a parallel circuit is formed 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 changes from the first impedance Z1 (i.e., the first mutant electrical signal) to the second impedance Z2 (i.e., the second mutant electrical signal) after Z1 and Z3 are connected in parallel. Since the total impedance after impedance parallel connection is less than any impedance value in the parallel circuit, that is, Z2 is less than Z1 and Z3. Therefore, the second mutant electrical signal is less than the first mutant electrical signal. Further, if the distance between the second bifurcation and the second electrode is much less than the distance between the first bifurcation and the second electrode, it will make the third impedance Z3 between the second bifurcation and the second electrode much less than the first impedance Z1 between the first bifurcation and the second electrode, and then make the second impedance Z2 much less than the first impedance Z1, that is, the second mutant electrical signal is much less than the first mutant electrical signal.

[0049] S12. Determine whether the test strip has absorbed the sample to be tested according to the difference between the first mutant electrical signal and the second mutant electrical signal and the preset threshold.

[0050] In this embodiment, the sample can be a blood sample, or a body fluid sample such as tear fluid, urine, and saliva, or a non-body fluid sample. Preferably, the sample is a blood sample, and the preset threshold is a threshold set in advance. Since when the test strip is in the fully-saturated state, the obtained second mutant electrical signal is smaller than the first mutant electrical signal, and further, the obtained second mutant electrical signal is much smaller than the first mutant electrical signal, while when the test strip is in the non-fully-saturated state, the obtained second mutant electrical signal is only slightly smaller than the first mutant electrical signal. Therefore, the difference between the first mutant electrical signal and the second mutant electrical signal can be compared with the preset threshold, and according to the comparison result, it can be determined whether the test strip has been fully saturated with the sample to be tested.

[0051] Compared with the prior art, for a method for judging whether a test strip is fully saturated provided by the present application, the test strip includes a first electrode, a second electrode, and a sampling channel. The first electrode includes a first bifurcation located at the sampling port close to the sampling channel and a second bifurcation located deeper inside the sampling channel. The second electrode is located between the first bifurcation and the second bifurcation. After it is determined that a sample has entered the sampling channel, an alternating voltage is continuously applied to the first electrode and the second electrode at a predetermined frequency, and the first mutant electrical signal between the first electrode and the second electrode, and the second mutant electrical signal between the first electrode and the second electrode are obtained. Then, according to the difference between the first mutant electrical signal and the second mutant electrical signal and the preset threshold, it is judged whether the test strip has been fully saturated with the sample to be tested. Through the above method, the present application can effectively judge whether the test strip has been fully saturated with the sample to be tested, so that no additional electrode for judging whether the sampling is sufficient needs to be added inside 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 the specific component in the sample to be tested detected.

[0052] As an implementation manner, in the embodiment of the present application, judging whether the test strip has been fully saturated with the sample to be tested according to the difference between the first mutant electrical signal and the second mutant electrical signal and the preset threshold includes:

[0053] Judging whether the difference between the first mutant electrical signal and the second mutant electrical signal is greater than the preset threshold. If it is, it is determined that the test strip has been fully saturated with the sample to be tested; if not, it is determined that the test strip has not been fully saturated with the sample to be tested.

[0054] In this embodiment, judging whether the difference between the first mutant electrical signal and the second mutant electrical signal is greater than the preset threshold. If the difference between the first mutant electrical signal and the second mutant electrical signal is greater than the preset threshold, it is determined that the test strip has been fully saturated with the sample to be tested; if the difference between the first mutant electrical signal and the second mutant electrical signal is less than or equal to the preset threshold, it is determined that the test strip has not been fully saturated with the sample to be tested.

[0055] As an implementation manner, in the embodiment of the present application, the preset threshold is determined by the following method:

[0056] S21. Under each of various test conditions formed by arbitrarily selecting one combination from multiple different temperatures and multiple different hematocrits, an alternating voltage is applied to the first electrode and the second electrode of multiple first test strips in an unfilled state at a predetermined frequency, and a first mutant test electrical signal between the first electrode and the second electrode of the multiple first test strips is obtained.

[0057] In this embodiment, the first test strip is a test strip with the same strip structure as that in Figure 2 for testing. The multiple different temperatures may include two extreme values of 5°C and 45°C, and may also include more other temperature values. The multiple different hematocrits may include two extreme values of 10% HCT and 70% HCT, and may also include more other hematocrit values.

[0058] In this embodiment, multiple first test strips are prepared according to the number of test conditions and the number of tests for each test condition. A test condition formed by selecting one temperature from multiple different temperatures and one hematocrit from multiple different hematocrits is used as the current test condition. Under the current test condition, one first test strip is selected as the current test strip, and the first test strip is made to be in an unfilled state. An alternating voltage is applied to the first electrode and the second electrode of the first test strip at a predetermined frequency, and a first mutant test electrical signal between the first electrode and the second electrode of the first test strip is obtained. In this way, multiple tests are performed to obtain the first mutant test electrical signals between the first electrode and the second electrode of multiple first test strips corresponding to the current test condition. In this way, until the first mutant test electrical signals between the first electrode and the second electrode of multiple first test strips in an unfilled state corresponding to each test condition are obtained.

[0059] Specifically, according to the extreme test temperatures of 5°C and 45°C, combined with the extreme hematocrits of HCT 10% and HCT 70%, four test conditions are formed. Each test condition needs to be tested 5 times. 20 first test strips can be prepared. Select the test condition of temperature 5°C and hematocrit HCT 10% from the temperatures of 5°C and 45°C and the hematocrits of HCT 10% and HCT 70% as the current test condition. Under the test condition of temperature 5°C and hematocrit 10% HCT, select a first test strip as the current test strip, make the first test strip in an unfilled state, apply an alternating voltage to the first electrode and the second electrode of the first test strip at a frequency of 10 KHz, and obtain the first mutation test signal between the first electrode and the second electrode of the first test strip in the unfilled sample injection state. Then, in this way, a total of 5 tests are performed to obtain the first mutation test signals between the first electrode and the second electrode of 5 first test strips corresponding to the test condition of temperature 5°C and hematocrit 10% HCT. In this way, until the first mutation test 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:

[0060] Table 1 Test conditions and 5 first mutation test signals corresponding to each test condition

[0061]

[0062] Among them, Z1 is the first mutation test signal. Specifically, Z1 is the first test impedance value.

[0063] S22. Under each test condition formed by arbitrarily selecting one from multiple different temperatures and multiple different hematocrits, apply an alternating voltage to the first electrode and the second electrode of multiple second test strips in a filled state at a predetermined frequency, and obtain the second mutation test signals between the first electrode and the second electrode of the multiple second test strips;

[0064] In this embodiment, the second test strip is a test strip for testing with the same strip structure as Figure 2 The multiple different temperatures can include two extreme values of 5°C and 45°C, and can also include more other temperature values. The multiple different hematocrits can include two extreme values of 10% HCT and 70% HCT, and can also include more other hematocrit values.

[0065] 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 formed by selecting one temperature from a plurality of different temperatures and one hematocrit from a plurality of different hematocrits is used as the current test condition. Under the current test condition, one second test strip is selected as the current test strip, and the second test strip is made to be in a fully absorbed state. An alternating voltage is applied to the first electrode and the second electrode of the second test strip at a predetermined frequency, and a second mutant test electrical signal between the first electrode and the second electrode of the second test strip is obtained. In this way, the test is carried out multiple times, and the second mutant test electrical signals between the first electrode and the second electrode of a plurality of second test strips corresponding to the current test condition are obtained. In this way, until the second mutant test electrical signals between the first electrode and the second electrode of a plurality of second test strips corresponding to each test condition are obtained.

[0066] Specifically, according to the extreme test temperatures of 5°C and 45°C, and the extreme hematocrits of HCT 10% and HCT 70%, four test conditions are combined. Each test condition needs to be tested 5 times, and 20 second test strips can be prepared. The test condition formed by selecting the temperature of 5°C from the temperatures of 5°C and 45°C and the hematocrit of HCT 10% from the hematocrits of HCT 10% and HCT 70% is used as the current test condition. Under the test condition of a temperature of 5°C and a hematocrit of 10% HCT, one second test strip is selected as the current test strip, and the second test strip is made to be in a fully absorbed state. An alternating voltage is applied to the first electrode and the second electrode of the second test strip at a frequency of 10 KHz, and the second mutant test electrical signal between the first electrode and the second electrode of the second test strip in the non-fully absorbed sample injection state is obtained. In this way, the test is carried out 5 times, and the second mutant test electrical signals between the first electrode and the second electrode of 5 second test strips corresponding to the test condition of a temperature of 5°C and a hematocrit of 10% HCT are obtained. In this way, until the second mutant 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:

[0067] Table 2 Test conditions and 5 second mutant test electrical signals corresponding to each test condition

[0068]

[0069] Among them, Z2 is the second mutant test electrical signal. Specifically, Z2 is the second test impedance value.

[0070] S23. According to the multiple first mutant test electrical signals and multiple second mutant test electrical signals corresponding to each test condition, obtain the test differences corresponding to each test condition, and construct a test difference set;

[0071] In this embodiment, one suitable first mutant test electrical signal among the multiple first mutant test electrical signals corresponding to each test condition and one suitable second mutant test electrical signal among the multiple second mutant test electrical signals can be used to obtain the test difference corresponding to this test condition. In this way, the test differences corresponding to each test condition among the multiple test conditions are obtained, and a test difference set is constructed based on the multiple test differences.

[0072] The test difference corresponding to this test condition can be obtained based on the minimum value among the multiple first mutant test electrical signals corresponding to each test condition and the maximum value among the multiple second mutant test electrical signals. Alternatively, the test difference corresponding to this test condition can be obtained based on the second smallest value among the multiple first mutant test electrical signals corresponding to each test condition and the second largest value among the multiple second mutant test electrical signals.

[0073] S24. Determine a preset threshold according to the test difference set.

[0074] In this embodiment, one of the multiple test differences in the test difference set can be used as the preset threshold, the minimum value of the multiple test differences in the test difference set can be used as the preset threshold, or the second smallest value of the multiple test differences in the test difference set can be used as the preset threshold.

[0075] As an implementation manner, in the embodiments of the present application, based on the multiple first mutant test electrical signals and the multiple second mutant test electrical signals corresponding to each test condition, the test differences corresponding to each test condition are obtained, and constructing a test difference set includes:

[0076] The test differences corresponding to each test condition are obtained based on the minimum value among the multiple first mutant test electrical signals corresponding to each test condition and the maximum value among the multiple second mutant test electrical signals, and a test difference set is constructed.

[0077] In this embodiment, the minimum value among the multiple first mutant test electrical signals corresponding to one test condition can be subtracted from the maximum value among the multiple second mutant test electrical signals to obtain the test difference corresponding to this test condition. In this way, the test differences corresponding to each test condition among the multiple test conditions are obtained, and a test difference set is constructed based on the multiple test differences.

[0078] Specifically, according to the data in Table 1 and Table 2, the minimum value of the five first test impedance values corresponding to the test conditions of temperature 5°C and hematocrit 10% is 2788.76, and the maximum value of the five second test impedance values is 1355.24. Subtracting the two values gives a test difference of 1433.52 corresponding to the test conditions of temperature 5°C and hematocrit 10%. In this way, a test difference of 6418.14 corresponding to the test conditions of temperature 5°C and hematocrit 70% is obtained, a test difference of 974.86 corresponding to the test conditions of temperature 45°C and hematocrit 10% is obtained, and a test difference of 3745.16 corresponding to the test conditions of temperature 45°C and hematocrit 70% is obtained. Based on the four test differences, a test difference set including 1433.52, 6418.14, 974.86, and 3745.16 is constructed.

[0079] As an implementation manner, in the embodiments of the present application, determining a preset threshold according to the test difference set includes:

[0080] Taking the minimum value in the test difference set as the preset threshold.

[0081] In this embodiment, by taking the minimum value in the test difference set constructed from the test differences corresponding to multiple test conditions as the preset threshold, the accuracy of sampling judgment under various temperature and hematocrit conditions can be effectively guaranteed.

[0082] Specifically, the minimum value in the test difference set is 974.86, and 974.86 can be used as the preset threshold.

[0083] As an implementation manner, in the embodiments of the present application, determining a preset threshold according to the test difference set includes:

[0084] Based on the minimum value in the test difference set, decreasing it by 10% to 30% to obtain a decreased value, and taking the decreased value as the preset threshold.

[0085] In this embodiment, considering the inevitable batch - to - batch differences between samples and test strips, and to ensure that the system design has sufficient redundancy to meet the requirements of instrument recognition and judgment, on the basis of the minimum value among multiple test differences, it can be decreased by 10% - 30%, preferably 20%, to obtain a decreased value, and taking the decreased value as the preset threshold to reduce the batch - to - batch differences between samples and test strips and the judgment errors caused by system design.

[0086] As an implementation manner, in the embodiments of the present application, based on the minimum value in the test difference set, decreasing it by 10% to 30% to obtain a decreased value, and taking the decreased value as the preset threshold includes:

[0087] Based on the minimum value in the test difference set, decrease it by 20% to obtain the decreased value, and use the decreased value as the preset threshold.

[0088] Specifically, based on the minimum value of 974.86 in the test difference set, decrease it by 20% to obtain the decreased value of 779.89.

[0089] As an implementation manner, in the embodiments of the present application, based on the minimum value in the test difference set, decrease it by 20% to obtain the decreased value, and use the decreased value as the preset threshold, including:

[0090] Based on the minimum value in the test difference set, decrease it by 20% and round it to an integer to obtain the decreased and rounded value, and use the decreased and rounded value as the preset threshold.

[0091] In this embodiment, in view of reducing the instrument cost, based on the minimum value in the test difference set, decrease it by 20% and round it to an integer to obtain the decreased and rounded value, and use the decreased and rounded value as the preset threshold. It can be rounded to the nearest ten, and further, it can be rounded to the nearest hundred.

[0092] Specifically, based on the decreased value of 779.89 obtained by decreasing 20% from the minimum value of 974.86 in the test difference set, it can be rounded to the nearest ten to obtain 780 after rounding, and further, it can be rounded to the nearest hundred to obtain 800 after rounding. Use 800 after rounding as the preset threshold.

[0093] In the embodiments of the present application, an experiment is designed to verify the structure of the full-suction judgment electrode and the method for judging sample full suction. Specifically, the experiment is carried out under the sample conditions of two extreme test temperatures (5°C and 45°C) and seven different hematocrits (HCT10%, HCT20%, HCT30%, HCT40%, HCT50%, HCT60%, HCT70%), that is, a total of 14 verification test conditions. Five tests are carried out under each verification test condition, including 3 times of sample full suction (S3 - S5, S8 - S10) and 2 times of sample non-full suction (S1 - S2, S6 - S7). The frequency of the alternating voltage is also 10KHz. Record the first verification test impedance between the second electrode and the first bifurcation of each first verification test strip and the second verification test impedance between the second electrode and the second bifurcation of each second verification test strip in the verification test. According to 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, verify whether it is consistent with the actual situation of whether the sample is fully sucked. The data of the verification experiment is shown in Table 3 below:

[0094] Table 3 Samples fully absorbed (S3-S5, S8-S10) and samples not fully absorbed (S1-S2, S6-S7) and corresponding judgment results obtained from test data

[0095]

[0096] 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, S1-S2, S6-S7 are actually not fully absorbed samples. According to the data in Table 3, it can be seen that the judgment results obtained by comparing the difference Z1-Z2 between the first verification test impedance Z1 and the second verification test impedance Z2 of the samples S3-S5, S8-S10 with the preset threshold of 800 are also fully absorbed, and the judgment results obtained by comparing the difference Z1-Z2 between the first verification test impedance Z1 and the second verification test impedance Z2 of the samples S1-S2, S6-S7 with the preset threshold of 800 are also not fully absorbed. It can be seen that through the test data, it is verified that the fully absorbed judgment electrode structure and the sample fully absorbed judgment method are very feasible, and the judgment accuracy of the sample fully absorbed judgment method is very high.

[0097] As Figure 3 shown, as an implementation manner, 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 branch 11 and the second branch 12, wherein the first branch 11 is the working electrode for the first detection index, and the second branch 12 is the sampling judgment electrode; the second electrode 20, the third electrode 40, and the fourth electrode 50 are respectively any one of the exclusive HCT and background electrode, reference electrode, and working electrode for the second detection index.

[0098] In this embodiment, it may be that the second electrode is the HCT and background electrode, the third electrode is the reference electrode, and the fourth electrode is the working electrode for the second detection index, or the second electrode is the HCT and background electrode, the third electrode is the working electrode for the second detection index, and the fourth electrode is the reference electrode, or the second electrode is the reference electrode, the third electrode is the HCT and background electrode, and the fourth electrode is the working electrode for the second detection index, or the second electrode is the reference electrode, the third electrode is the working electrode for the second detection index, and the fourth electrode is the HCT and background electrode, or the second electrode is the working electrode for the second detection index, the third electrode is the reference electrode, and the fourth electrode is the HCT and background electrode, or the second electrode is the working electrode for the second detection index, the third electrode is the HCT and background electrode, and the fourth electrode is the reference electrode. Further, the second electrode, the third electrode, and the fourth electrode may also be the working electrode for the second detection index, the working electrode for the third detection index, and the working electrode for the fourth detection index. One or two of these electrodes can be defined as a multiplexed electrode through the instrument software, such as the HCT electrode, the background electrode, or the reference electrode.

[0099] 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 indexes: common electrochemistry detection indexes such as blood glucose, uric acid, blood ketone, creatinine, lactic acid, hemoglobin, glycated hemoglobin, cholesterol, lipoprotein, triglyceride, etc.

[0100] Taking the common blood glucose and blood ketone dual-index electrochemical test strip as an example, the index detection process is briefly described as follows. 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 the background electrode are used as the HCT electrode, an alternating excitation voltage with 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. The impedance signal is substituted into a preset linear equation to obtain the hematocrit of the blood sample, that is, HCT. Among them, the preset frequency is a pre-set frequency, and the preset linear equation is an equation obtained by fitting according to the test results. When the HCT and the background electrode are used as the background electrode, 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, which is the background current signal of the sample. The magnitude of the background current signal 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, and a current signal that continuously decreases over time can be detected on the blood ketone working electrode. The current intensity is in the range of nanoamperes to microamperes. 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 compensated and corrected based on the background current signal to obtain a corrected current signal representing the blood ketone concentration of the blood sample to be tested. A weak DC excitation voltage is applied between the blood glucose working electrode and the reference electrode, and a current signal that continuously decreases over time can be detected on the blood glucose working electrode. The current intensity is in the range of nanoamperes to microamperes. 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 compensated and corrected based on the background current signal to obtain a corrected current signal representing the blood glucose concentration of the blood sample to be tested.

[0101] As Figure 3 shown, as an implementation manner, in the embodiment of the present application, the second electrode 20 is the electrode closest to the second branch 12 between the first branch 11 and the second branch 12.

[0102] In this embodiment, by using the electrode closest to the second branch 12 between the first branch 11 and the second branch 12 as the second electrode 20, the difference between the obtained first electrical signal and the second electrical signal can be made larger, making the result of the sampling judgment more accurate.

[0103] 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, and the fourth electrode 50 is between the third electrode 40 and the first bifurcation 11 of the first electrode 10. The fourth electrode 50 is the HCT and background electrode.

[0104] The embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The same or similar parts among the various embodiments can be referred to each other.

[0105] 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 obvious to those skilled in the art. The general principles defined herein can 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 rather 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; Determining 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; 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.

2. The method according to claim 1, 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.

3. The method according to claim 2, 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.

4. The method according to claim 3, 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.

5. The method according to claim 3, 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.

6. The method according to claim 5, 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.

7. The method according to claim 6, 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.

8. The method according to any one of claims 1 to 7, 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.

9. The method according to claim 8, 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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