A blood detection system and method

Abstract

The present invention discloses a blood detection system and method. Among them, the system includes: a detection instrument and a detection strip; the detection instrument includes a temperature sensor, a microprocessor, a detection strip connection port, and a display window; the detection strip includes a third layer board, an electrode layer, a reagent layer, a second layer board, and a first layer board, and the production raw material of the reagent layer contains water-soluble metal salts. Based on the electrochemical detection technology, the present invention can detect the viscosity of blood samples in a relatively wide temperature range with high detection accuracy by using the correlation between the solubility of salts and the electrical signals obtained by the detection strip.

Description

Technical Field

[0001] Embodiments of the present invention relate to the technical field of blood physical and chemical property detection, and in particular to the technical field of blood electrochemical detection. Background Art

[0002] Blood consists of plasma and blood cells suspended therein. Its physical and chemical properties include color, specific gravity, viscosity, osmotic pressure, and acidity and alkalinity. Viscosity, as one of the physical and chemical properties of blood, is an important indicator reflecting the smoothness of blood flow in blood vessels. When blood flows in blood vessels, resistance is generated due to the friction between molecules or particles of various substances inside the blood, making the blood have a certain viscosity. Blood viscosity mainly depends on the number of red blood cells and the content of plasma proteins. In addition, it also includes the shape of blood cells and their distribution characteristics in blood flow, surface structure and internal state, deformability, and their interactions with each other. Generally, the fluidity of a fluid is reflected and measured by viscosity. Therefore, the most important indicator reflecting the fluidity and viscosity of blood is the blood viscosity. The viscosity of whole human blood is mainly affected by the percentage of red blood cells in the total blood volume. In addition, it is also related to factors such as temperature, the state of red blood cells (such as red blood cell deformability and red blood cell aggregation), the content of hemoglobin and other proteins, and plasma viscosity. Also, because whole blood is a non-Newtonian fluid, its viscosity is affected by the shear rate of blood flow. At room temperature, the apparent viscosity of whole human blood at a high shear rate (200 / s) is generally between 4 and 6 mPa·s. Long-term dynamic monitoring of blood viscosity is of great significance for the monitoring and prevention of cardiovascular diseases because the onset and pathological characteristics of cardiovascular diseases are related to long-term accumulation, and during this process, changes in blood viscosity status often occur. Factors such as an increase in the number of red blood cells and platelets, a decrease in red blood cell deformability, an increase in plasma proteins and blood lipids, etc. will all lead to an increase in blood viscosity, which may thereby induce an increase in blood flow resistance, slow down blood flow, reduce organ blood supply, and cause diseases such as coronary heart disease, myocardial infarction, and cerebral thrombosis. Anemia and some hemorrhagic diseases (such as gastrointestinal bleeding, advanced tumors, functional uterine bleeding, etc.) are accompanied by a decrease in blood viscosity.

[0003] At present, the methods for measuring liquid viscosity mainly include capillary viscometry, rotational viscometry, and microflow-pressure sensing viscometry, etc. Among them, capillary viscometry can only be used to measure plasma viscosity, and currently, the instruments for blood viscosity detection in hospitals are mainly rheometers based on rotational viscometry or microflow-pressure sensing viscometry. The test results of such instruments are diverse and accurate, but the instruments are expensive, the test cycle is long, and each test requires hundreds of microliters of blood, making it difficult to achieve real-time and rapid viscosity testing. The principle of the non-invasive blood viscosity detection system proposed in Patent CN 110897617A is based on the linear relationship between the waveform coefficient of fingertip volume pulse wave and blood viscosity, and the accuracy and reliability of the test results are inferior to those of invasive methods. Electrochemical biosensors are now widely used to determine the concentrations of various analytes in blood samples. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the present invention provides a blood detection system and method, which are based on electrochemical methods and can quickly and accurately measure the viscosity of blood with a small amount of blood within a wide range of operating temperatures.

[0005] In a first aspect, the present invention further provides a blood detection system, including a detection instrument and a detection strip;

[0006] The detection instrument includes a temperature sensor, a microprocessor, a detection strip connection port, and a display window; the detection strip includes a third layer board, an electrode layer, a reagent layer, a second layer board, and a first layer board.

[0007] Optionally, the production raw materials of the reagent layer contain water-soluble metal salts.

[0008] Optionally, the production raw materials of the reagent layer further include a surfactant, a water-soluble polymer, and deionized water.

[0009] Optionally, the water-soluble metal salts include at least one of sodium chloride, potassium chloride, sodium sulfate, potassium sulfate, potassium carbonate, sodium carbonate, sodium nitrate, potassium nitrate, sodium monohydrogen phosphate, sodium dihydrogen phosphate, potassium monohydrogen phosphate, and potassium dihydrogen phosphate.

[0010] Optionally, the production raw materials of the reagent layer include 10-30% by mass of water-soluble metal salts, 0.1%-4% by mass of a surfactant, and 2%-15% by mass of a water-soluble polymer.

[0011] Optionally, the electrode layer is located above the third layer board, the reagent layer is located above the electrode layer, the second layer board material has adhesiveness for pasting the third layer board and the first layer board, and the second layer board is provided with a suction groove for accommodating a blood sample.

[0012] Second aspect, the present invention also provides a blood detection method, which is implemented by using the blood detection system described in any one of the above embodiments, and includes:

[0013] S110. Insert the test strip into the test instrument and start the test instrument, and apply a first DC voltage to the first electrode and the second electrode of the test strip;

[0014] S120. Introduce the blood sample into the suction groove of the test strip, connect the first electrode and the second electrode, identify a first current signal through the test instrument, and record the ambient temperature at this time through the temperature sensor of the test instrument;

[0015] S130. After the test instrument identifies the first current signal, apply a second AC voltage to the first electrode, and the test instrument detects a second electrical signal of the blood sample after a certain time;

[0016] S140. Process the second electrical signal through the microprocessor of the test instrument to obtain a processed second electrical signal;

[0017] S150. Substitute the processed second electrical signal and the ambient temperature into the calculation formula of the blood sample viscosity preset in the microprocessor to calculate the viscosity value of the blood sample.

[0018] Optionally, the calculation formula of the blood sample viscosity is:

[0019] η=(K1*T + B1)x+(K2*T + B2);

[0020] Wherein, η represents the blood viscosity value, T represents the ambient temperature, x represents the processed second electrical signal, and K1, B1, K2, and B2 are all constant coefficients.

[0021] Optionally, the value range of K1 is 0.5 to 3.0, the value range of B1 is 2.0 to 6.0, the value range of K2 is -1.0 to 0, and the value range of B2 is 0 to 2.0.

[0022] Optionally, the value range of the first DC voltage is 0.1 to 0.8V.

[0023] Optionally, the second AC voltage is a low-frequency AC voltage or a high-frequency AC voltage, the peak value range of the second AC voltage is 0.05 to 1V, the frequency range of the second AC voltage is 10 to 1000Hz, and the application time range of the second AC voltage is 1 to 10 seconds.

[0024] The present invention is based on electrochemical detection technology and calculates the viscosity of a blood sample by utilizing the correlation between the solubility of salts and the electrical signals obtained by a test strip. It can detect the viscosity of blood samples within a relatively wide temperature range with high detection accuracy. Moreover, the present invention requires a small amount of blood sample, the operation process is simple, fast, and the detection time is only a few seconds to more than ten seconds, which is very rapid. It overcomes the problems of poor real-time performance and excessive blood collection volume in traditional blood viscosity detection, and can significantly improve the detection efficiency. In addition, the detection system provided by the present invention has a simple, reasonable and compact structure design, is convenient to carry, and has an economical manufacturing cost, which is conducive to large-scale production and manufacturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic structural diagram of the test strip in Embodiment 1 of the present invention;

[0026] Figure 2 It is a schematic circuit diagram of the detection instrument in Embodiment 1 of the present invention;

[0027] Figure 3 It is a flowchart of the blood detection method in Embodiment 1 of the present invention;

[0028] Figure 4 It is a schematic diagram showing the change of the electrical signal value (test AD value) obtained by the blood detection system of the present invention when testing a solution sample in Embodiment 2 with time;

[0029] Figure 5 It is a schematic diagram showing the relationship between the processed value of the electrical signal value obtained by the blood detection system of the present invention when testing a solution sample and the mass fraction of sodium chloride in Embodiment 2;

[0030] Figure 6 It is a schematic diagram showing the relationship between the processed value of the electrical signal value obtained by the blood detection system of the present invention when testing a solution sample and the mass fraction of polyethylene glycol - 6000 in Embodiment 2;

[0031] Figure 7 It is a schematic diagram showing the relationship between the processed value of the electrical signal value obtained by the blood detection system of the present invention when testing a solution sample and the viscosity of the solution in Embodiment 2;

[0032] Figure 8 It is a schematic diagram comparing the viscosity test results of 50 blood samples from different sources (including human fingertip blood samples and modulated human blood samples) by using the blood detection system in the embodiment of the present invention and a rheometer;

[0033] Reference numerals: 1. Third layer board; 2. Electrode layer; 201. First electrode; 202. Second electrode; 3. Reagent layer; 4. Second layer board; 401. Suction groove; 5. First layer board; 501. Air outlet hole; 6. Microprocessor; 7. Test strip connection port; 8. Temperature sensor; 9. Display window. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that for the convenience of description, only the parts related to the present invention rather than all the structures are shown in the drawings.

[0035] The technical solution of the embodiment of the present invention is based on the electrochemical detection technology. When the test strip is used to detect a blood sample, an alternating current working voltage is provided for the electrode system, so as to obtain an electrical signal related to the kinetic performance of the blood sample. The value obtained after the conversion of this electrical signal by analog-to-digital (AD) conversion is the AD value. The change of the AD value during the process of blood contacting the electrode is related to the hydration process of the electrode surface. After a large amount of data analysis, it is found that it is related to the salt dissolution kinetics on the surface of the test strip during a specific period, that is, the AD value is proportional to the concentration of sodium chloride dissolved on the electrode surface.

[0036] Embodiment 1

[0037] As Figures 1 - 2 shown, Figure 1 and Figure 2 respectively show a test strip and a test instrument in a blood detection system provided by Embodiment 1 of the present invention.

[0038] The test instrument includes a microprocessor 6, a test strip connection port 7, a temperature sensor 8, and a display window 9; the test strip includes a third-layer board 1, an electrode layer 2, a reagent layer 3, a second-layer board 4, and a first-layer board 5.

[0039] Among them, the production raw material of the reagent layer 3 contains a water-soluble metal salt, and the water-soluble metal salt is one or a mixture of sodium chloride, potassium chloride, sodium sulfate, potassium sulfate, potassium carbonate, sodium carbonate, sodium nitrate, potassium nitrate, sodium hydrogen phosphate, sodium dihydrogen phosphate, potassium hydrogen phosphate, and potassium dihydrogen phosphate.

[0040] Further, the raw materials for making the reagent layer further include a surfactant, a water-soluble polymer, and deionized water; the surfactant can be one or a combination of Triton X-100, sodium dodecyl sulfate, perfluorooctane sulfonate, sodium stearate, sodium lauryl alcohol polyoxyethylene ether sulfate, ammonium dodecyl sulfate, dodecylbenzenesulfonic acid, triethanolamine lauryl sulfate, and sodium fatty alcohol hydroxyethyl sulfonate; the water-soluble polymer is one or a combination of polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), hydroxyethyl cellulose (HEC), hydroxypropyl cellulose (HPC), carboxymethyl cellulose (CMC), hydroxypropyl methyl cellulose (HPMC), polyethylene glycol (PEG), polyethyl acrylate (PEA), polyethylene oxide (PEO), polyacrylamide (PAM), hydrolyzed polyacrylamide (HPAM), polyvinylpyrrolidone-vinyl acetate (PVP-VA), polyvinylamine, cellulose acetate, and polyamide.

[0041] Optionally, the mass fraction range of the water-soluble metal salt contained in the raw materials for making the reagent layer is 10-30%, the mass fraction range of the surfactant is 0.1%-4%, and the mass fraction range of the water-soluble polymer is 2%-15%.

[0042] Further, the electrode layer 2 is located above the first layer of the third layer board, and at least includes a first electrode 201 and a second electrode 202. The reagent layer 3 is located above the electrode layer 2. The material of the second layer board 4 has adhesiveness and is used for pasting the third layer board 1 and the first layer board 5. The second layer board 4 is provided with a suction groove 401 for accommodating a blood sample; preferably, the materials of the first layer board 5 and the third layer board 1 can be ceramics, glass plates, or organic polymer materials; preferably, the first layer board 5 and the third layer board 1 can respectively adopt one of polyethylene terephthalate, polyvinyl chloride, and polycarbonate; preferably, the volume of the suction groove 6 is 0.5 microliters to 20 microliters. A transparent confirmation window corresponding to the suction groove 401 is provided on the first layer board 5 to facilitate observing the loading state of the blood sample in the suction groove. An air outlet 501 is provided at the end of the confirmation window. The combined setting of the suction groove 401 and the air outlet 501 can continuously introduce the blood sample into the suction groove, enabling the blood sample to fully contact and react with the reagent layer.

[0043] For further reference Figure 3 , Figure 3 A blood detection method provided for Embodiment 1, which specifically includes:

[0044] S110. Insert the test strip into the test instrument and start the test instrument, and apply a first DC voltage to the first electrode and the second electrode of the test strip.

[0045] S120. Introduce the blood sample into the suction groove of the test strip, connect the first electrode and the second electrode, identify the first current signal through the detection instrument, and record the ambient temperature at this time through the temperature sensor of the detection instrument.

[0046] Among them, the first DC voltage is preferably 0.1 - 0.8V, more preferably 0.2 - 0.5V; the peak value of the second AC voltage is preferably 0.1 - 0.8V, more preferably 0.2 - 0.5V, the frequency of the second AC voltage is preferably 50 - 500Hz; the application time of the second AC voltage is preferably 2 - 5 seconds.

[0047] S130. After the detection instrument identifies the first current signal, apply the second AC voltage to the first electrode, and the detection instrument detects the second electrical signal of the blood sample after a certain time.

[0048] The second AC voltage can be a low - frequency or high - frequency AC voltage, with a peak value of 0.05 - 1V, a frequency of 10 - 1000Hz, and an application time of 1 - 10 seconds. The second electrical signal of the blood sample, that is, the AD value, will be detected.

[0049] S140. Process the second electrical signal through the microprocessor of the detection instrument to obtain the processed second electrical signal.

[0050] Among them, the method for the microprocessor to process the AD value can be to select the AD value at a certain moment, select the maximum value among multiple AD values, select the minimum value among multiple AD values, select the AD values at multiple moments and calculate their average value, or select the AD values within a certain period of time and calculate their average value, and then perform basic algebraic operations; preferably, select the AD values within a certain period of time, calculate their average value, then perform a linear mapping to a specific interval and take the reciprocal to obtain the AD signal processing value x.

[0051] S150. Substitute the processed second electrical signal and the ambient temperature into the calculation formula of the blood sample viscosity preset in the microprocessor to calculate the viscosity value of the blood sample.

[0052] Specifically, the calculation formula of the blood sample viscosity is:

[0053] η=(K1*T + B1)x+(K2*T + B2);

[0054] Among them, η represents the blood viscosity value, T represents the ambient temperature identified by the temperature sensor, x represents the calculated value of the electrical signal identified by the microprocessor, and K1, B1, K2, B2 are constant coefficients.

[0055] Optionally, the value range of K1 is 0.5 to 3.0, the value range of B1 is 2.0 to 6.0, the value range of K2 is -1.0 to 0, and the value range of B2 is 0 to 2.0.

[0056] This embodiment is based on electrochemical detection technology and calculates the viscosity of a blood sample by using the correlation between the solubility of salts and the electrical signals obtained by the test strip. It can detect the viscosity of blood samples in a relatively wide temperature range, requires a small amount of blood sample, has a simple and fast operation process, a short detection time, and high detection accuracy. It overcomes the problems of poor real-time performance and excessive blood collection volume in traditional blood viscosity detection, and can significantly improve the detection efficiency. In addition, the system structure is designed simply, is easy to carry, has an economical manufacturing cost, and is conducive to large-scale production and manufacturing.

[0057] Embodiment 2

[0058] The blood detection system provided in this embodiment includes a detection instrument and a test strip. Among them, the detection instrument includes a microprocessor, a test strip connection port, a temperature sensor, and a display window; the test strip includes a third layer board, an electrode layer, a reagent layer, a second layer board, and a first layer board.

[0059] In this embodiment, the material of the third layer board is polyethylene terephthalate, which serves as the bottom board of the test strip; the electrode layer is formed on the third layer board and includes at least a first electrode and a second electrode, both of which are made by screen printing with conductive carbon paste; the reagent layer is formed on the first electrode, and the raw materials for making the reagent layer include water-soluble metal salt sodium chloride, surfactant Triton X-100, water-soluble polymer polyvinyl alcohol (PVA), and deionized water. Among them, the mass fraction of sodium chloride is 20%, the mass fraction of Triton X-100 is 1%, and the mass fraction of polyvinyl alcohol (PVA) is 10%; the surfactant Triton X-100 is conducive to the uniform spreading of the reagent layer above the electrode layer during the manufacturing process to form a uniform thickness, and the water-soluble polymer polyvinyl alcohol (PVA) plays a supporting role; the second layer board uses a double-sided adhesive with adhesiveness to paste the third layer board and the first layer board together. The second layer board is provided with a suction groove for sucking the blood sample to be tested, and the volume of the suction groove is 0.5 microliters; the material of the first layer board 5 is polyethylene terephthalate, and a transparent confirmation window corresponding to the suction groove is provided on the first layer board to facilitate observing the loading state of the blood sample in the suction groove. An air outlet is provided at the end of the confirmation window. The combined setting of the suction groove and the air outlet can continuously introduce the blood sample into the suction groove, so that the blood sample can fully contact and react with the reagent layer.

[0060] The dissolution of sodium chloride is controlled by diffusion process and surface reaction or by mixed reaction, which can usually be described by the Stumm equation. It is reported in the literature that the dissolution kinetics of alkali metals satisfies the first-order Stumm equation, which is a diffusion-controlled process. The dissolution rate is proportional to the difference between the current concentration and the saturation concentration. That is, the concentration Ct of the dissolved salt at time t satisfies the following first-order Stumm equation: dCt / dt = K(Cs - Ct); the following parameters are also involved in this equation: Cs is the saturation concentration of the salt in this solvent, and K is the kinetic coefficient, which is related to the diffusion coefficient and kinetic viscosity of the solvent sample, etc. After integrating the first-order Stumm equation, we get Ct = Cs - exp(-K*t + B), where B is the integration constant.

[0061] Since the AD value is related to Ct, within a certain viscosity range, at a specific temperature, the AD value at a specific moment or the AD signal processing value obtained after basic arithmetic processing of the AD value within a specific time period and the liquid viscosity can be regarded as having a linear relationship. Using the above relationship, a blood viscosity test equation containing temperature can be obtained. Substituting the environmental temperature T and the AD signal processing value into the test equation, the accurate blood viscosity can be obtained.

[0062] The blood detection system of this embodiment is used to test the viscosity of simulated solutions. Solutions of two solutes, sodium chloride and polyethylene glycol - 6000 (PEG - 6K), with gradient concentrations are selected as simulated solutions to evaluate the influence of the conductivity and salt concentration of the samples on the test strip, and to determine the measurable viscosity range. The mass fraction of sodium chloride in the gradient concentration sodium chloride solution is 0.10%, 0.15%, 0.20%, 0.25%, 0.30% and 0.35%, and it contains 1.2% by volume of glycerol. The mass fraction of PEG - 6k in the gradient concentration PEG - 6k solution is 0, 4.2%, 10%, 15%, 20% and 25%, and it contains 0.3% by mass of sodium chloride.

[0063] The tests in this embodiment are all completed at room temperature (23 ± 2°C). The conductivity of the above two solutions is measured using a conductivity meter, with the unit of mS / cm; the viscosity of the gradient concentration PEG - 6k solution is measured using a rotational viscometer, with the unit of mPa·s. During the detection, an AC working voltage with a peak value of 200 mV and a frequency of 200 Hz is applied to the electrode system to obtain the electrical signal, that is, the AD value, within 0 - 3 s. Under each test condition, the test is carried out 5 times.

[0064] Next, preferably, the time range in which the effective AD value can be measured is determined. For the sake of convenience in processing, first divide the AD value by 200 to obtain the test AD value. Select the test AD value and the corresponding time, and according to different time ranges, such as four segments of 0 - 3.0 s, 0.5 - 3.0 s, 1.5 - 3.0 s, and 2.0 - 3.0 s, respectively use the non-linear fitting method to perform multi-parameter fitting on the data according to the function y = y0 + A1*exp(-(x - x0) / t1). Preferably select the time range with R2 > 0.99 and the longest time length. As Figure 4 shown, the schematic diagram of the change of the test AD value with time for the solution sample with a PEG-6k mass fraction of 25%, and the multi-parameter fitting result with the optimal time length, the fitting R 2 is greater than 0.995. Select the time period that conforms to the first-order Stumm equation in this time period. In this example, the preferably effective AD value time range is 0.5 - 3 s. Calculate the average value of the test AD value within 0.5 - 3.0 s, and take the reciprocal of this average value. For the sake of convenient expression, the reciprocal value of this average value is denoted as the AD signal processing value x.

[0065] As Figure 5 shown, the results of the test strip testing gradient concentration sodium chloride solutions: The AD signal processing value measured by the instrument slightly decreases as the mass fraction of sodium chloride in the solution increases, while the conductivity of the solution increases as the sodium chloride concentration increases.

[0066] As Figure 6 shown, the results of the test strip testing gradient concentration PEG-6k solutions: The AD signal processing value measured by the instrument increases as the mass fraction of PEG-6k in the solution increases, while the conductivity of the solution decreases as the PEG-6k concentration increases.

[0067] As Figure 7 shown, taking the AD signal processing value obtained by the test strip testing gradient concentration PEG-6k solutions as the ordinate and the viscosity of the corresponding solution measured by a rotational viscometer as the abscissa, perform linear fitting on the average value of the test AD value using the least squares method. The results show that for the PEG-6k venous blood simulation solution, there is a good linear relationship between the AD signal processing value and the viscosity value when the viscosity is within 1 - 12 mPa·s, R 2 = 0.995.

[0068] Example 3

[0069] The blood viscosity detection system provided in this example includes a detection instrument and a test strip. The detection instrument includes a microprocessor, a test strip connection port, a temperature sensor, and a display window; the test strip includes a third layer board, an electrode layer, a reagent layer, a second layer board, and a first layer board.

[0070] The material of the third-layer board is polyethylene terephthalate, serving as the bottom board of the test strip; the electrode layer, formed on the third-layer board, at least includes a first electrode and a second electrode, both of which are made by screen printing with conductive carbon paste; the reagent layer is formed on the first electrode, and the production raw materials of the reagent layer include water-soluble metal salt sodium chloride, surfactant Triton X-100, water-soluble polymer hydroxyethyl cellulose (HEC), and deionized water, where the mass fraction of sodium chloride is 15%, the mass fraction of Triton X-100 is 2%, and the mass fraction of hydroxyethyl cellulose (HEC) is 8%; the surfactant Triton X-100 is beneficial to the uniform spreading of the reagent layer above the electrode layer during the production process to form a uniform thickness, and the water-soluble polymer hydroxyethyl cellulose (HEC) plays a supporting role; the second-layer board uses a double-sided adhesive with adhesiveness to paste the third-layer board and the first-layer board together. The second-layer board is provided with a suction groove for sucking the blood sample to be tested, and the volume of the suction groove is 3 microliters; the material of the first-layer board is polyethylene terephthalate, and the first-layer board is provided with a transparent confirmation window corresponding to the suction groove to facilitate observing the loading state of the blood sample in the suction groove. An air outlet is provided at the end of the confirmation window. The cooperation of the suction groove and the air outlet can continuously introduce the blood sample into the suction groove, enabling the blood sample to fully contact and react with the reagent layer.

[0071] Five kinds of venous whole blood samples with the percentages of plasma and red blood cells in the whole blood volume being 15%, 30%, 42%, 55%, and 70% were prepared; then, at environmental temperature conditions of 4°C, 10°C, 17°C, 23°C, and 30°C respectively, a rotational viscometer was used to measure and record the apparent viscosity values of the plasma and the above five kinds of venous whole blood samples at a shear rate of 200 / s, with the unit of mPa·s.

[0072] The blood detection system of this embodiment was used to test the plasma and the above five kinds of venous whole blood samples in sequence, and each test condition was tested 5 times. Specifically, first, the test strip was inserted into the detection instrument, and the detection instrument was started. The first DC voltage applied between the first electrode and the second electrode was 500 mV; the sample to be tested was introduced into the suction groove of the test strip. The blood sample contacted the reagent layer, the first electrode and the second electrode were connected, the detection instrument recognized the first current signal, and the temperature sensor recorded the ambient temperature T at this time; then the second AC voltage applied was 200 mV, the frequency was 200 Hz, and the duration was 3 seconds to obtain the second electrical signal within 0 - 3 s, that is, the AD value. The microprocessor 6 performed AD value processing. First, the AD value was divided by 200 to obtain the test AD value. The test AD value and the corresponding time were selected, and different time ranges were chosen, such as four segments of 0 - 3.0 s, 0.5 - 3.0 s, 1.0 - 3.0 s, and 2.0 - 3.0 s. The data was respectively multi-parameter fitted using the non-linear fitting method according to the function y = y0 + A1*exp(-(x - x0) / t1). Preferably R2 The time range with an AD value greater than 0.99 and the longest time length. In this embodiment, the average value of the AD values within 1 - 3 s is selected, and the reciprocal of this average value is taken to obtain the AD signal processing value x; record the AD signal processing value x and calculate its average value, as shown in Tables 1 - 5, where CV represents the coefficient of variation, which is the ratio of the standard deviation to the average value.

[0073] Table 1 AD signal processing value data at 4°C

[0074]

[0075]

[0076] Table 2 AD signal processing value data at 10°C

[0077]

[0078] Table 3 AD signal processing value data at 17°C

[0079]

[0080]

[0081] Table 4 AD signal processing value data at 23°C

[0082]

[0083] Table 5 AD signal processing value data at 30°C

[0084]

[0085] It can be seen from the CV values in Tables 1 - 5 that the AD signal processing values measured by the blood detection system provided in this embodiment have good repeatability.

[0086] Process the experimental data in Tables 1 - 5:

[0087] (1) At 4°C, 10°C, 17°C, 23°C, and 30°C respectively, with the average value of the AD signal processing value as the abscissa and the high shear apparent viscosity of the corresponding blood sample as the ordinate, perform linear fitting according to the least squares method to obtain 5 groups of viscosity test equations, as shown in Table 6.

[0088] Table 6 Coefficients and R of viscosity test equations at different ambient temperatures 2

[0089] Ambient temperature (°C) First-order coefficient Constant term <![CDATA[R 2 > 4 12.27 0.6457 0.9978 10 21.03 -0.1567 0.9934 17 34.40 -0.9851 0.9961 23 54.83 -2.0295 0.9990 30 59.07 -1.8540 0.9892

[0090] (2) Taking 4°C, 10°C, 17°C, 23°C, and 30°C as the abscissa and the first-order term coefficient of the viscosity test equation at each temperature as the ordinate, perform a linear fit to obtain where k represents the first-order term coefficient, T represents the temperature, and K1 and B1 are the fitting coefficients.

[0091] (3) Taking 4°C, 10°C, 17°C, 23°C, and 30°C as the abscissa and the constant term of the viscosity test equation at each temperature as the ordinate, perform a first-order linear fit to obtain b = K2*T + B2, where b represents the constant term, T represents the temperature, and K2 and B2 are the fitting coefficients.

[0092] (4) The viscosity test equation containing the temperature parameter is η = (K1*T + B1)x + (K2*T + B2), where η represents the blood viscosity value, T represents the ambient temperature, x represents the AD signal processing value, and K1, B1, K2, and B2 are the fitting coefficients;

[0093] Substitute the ambient temperature T and the AD signal processing value x of the blood sample into η = (K1*T + B1)*x + (K2*T + B2), and the apparent viscosity of the blood sample can be obtained. From Table 6 linear fit R 2 It can be seen that there is a good linear relationship between the measured high-shear viscosity of the blood sample and the measured AD value data at different ambient temperatures.

[0094] Using the linear fit results of the viscosity test equations at different ambient temperatures in Table 6, taking each temperature as the abscissa and the first-order term coefficient of the corresponding viscosity test equation as the ordinate, perform a linear fit to obtain the empirical equation (1):

[0095] k = 1.955*T + 3.4841 (1)

[0096] where k represents the first-order term coefficient in the viscosity test equation, T represents the temperature, R 2 = 0.9640.

[0097] Then, taking each temperature as the abscissa and the constant term coefficient of the corresponding viscosity test equation as the ordinate, perform a linear fit to obtain the empirical equation (2):

[0098] b = -0.1051*T + 0.8904 (2)

[0099] where b represents the constant term coefficient in the viscosity test equation, T represents the temperature, R 2 = 0.9107.

[0100] Combining the above empirical equations (1) and (2) to obtain the blood viscosity test equation containing temperature, that is, equation (3):

[0101] η = (1.955 * T + 3.4841) * x + (-0.1051 * T + 0.8904) (3)

[0102] Among them, η represents the blood viscosity value, T represents the temperature, and x represents the AD signal processing value.

[0103] After the microprocessor obtains the AD signal processing value x, the calculation module obtains the viscosity values of the plasma and the above 5 venous whole blood samples according to the environmental temperature T, the AD signal processing value x, and the calculation formula: η = (1.955 * T + 3.4841) * x + (-0.1051 * T + 0.8904).

[0104] Since the test sample is introduced into the suction tank, the detection instrument counts down for 5 seconds, and the detection result is displayed on the display window. Record the detection result, and calculate the absolute deviation and relative deviation between the average value of the 5 test results of the blood detection system in this embodiment and the test result of the rotational viscometer. Among them, the absolute deviation = the average value of the blood viscosity measured by the test strip - the blood viscosity value measured by the rotational viscometer, and the relative deviation = the absolute deviation / the average value of the blood viscosity measured by the test strip; the specific data are shown in Tables 7 to 11 as follows:

[0105] Table 7 Viscosity test results of plasma and 5 venous whole blood samples at 4°C (unit: mPa·s)

[0106]

[0107] Table 8 Viscosity test results of plasma and 5 venous whole blood samples at 10°C (unit: mPa·s)

[0108]

[0109]

[0110] Table 9 Viscosity test results of plasma and 5 venous whole blood samples at 17°C (unit: mPa·s)

[0111]

[0112] Table 10 Viscosity test results of plasma and 5 venous whole blood samples at 23°C (unit: mPa·s)

[0113]

[0114]

[0115] Table 11 Viscosity test results of plasma and 5 venous whole blood samples at 30°C (unit: mPa·s)

[0116]

[0117] Example 4

[0118] The blood detection system provided in this example is only different from the blood detection system provided in Example 3 as follows:

[0119] The material of the third layer plate of the test strip is polyvinyl chloride. The first electrode and the second electrode are both made by screen printing with conductive silver paste. The raw materials for making the reagent layer include water-soluble metal salt sodium sulfate, surfactant dodecylbenzenesulfonic acid, water-soluble polymer polyvinylpyrrolidone-vinyl acetate (PVP-VA), and deionized water. Among them, the mass fraction of sodium sulfate is 30%, the mass fraction of dodecylbenzenesulfonic acid is 4%, and the mass fraction of polyvinylpyrrolidone-vinyl acetate (PVP-VA) is 15%. The volume of the suction tank is 10 microliters.

[0120] The same detection ambient temperature, plasma, and 5 venous whole blood samples as in Example 3 are used. The blood detection system of this example is used to test plasma and 5 venous whole blood samples in turn. Each test condition is tested 5 times. The detection process is only different from the detection process in Example 3 as follows:

[0121] The first DC voltage applied to the first electrode and the second electrode is 1000 mV; the second AC voltage applied is 1000 mV, the frequency is 1000 Hz, and the duration is 1 second to obtain the second electrical signal within 0 - 1 s, that is, the AD value. The microprocessor processes the AD value, selects the AD value at 0.5 - 1 second, and performs calculations to obtain the AD signal processing value x. The processing process is similar to that in Example 3 and will not be elaborated here. The calculation formula in the calculation module of the microprocessor finally obtained is: η=(0.498*T + 6.1761)*x + (-0.0651*T + 2.1317).

[0122] Since the time when the test sample is introduced into the suction tank, the detection instrument counts down for 3 seconds, and the detection result is displayed on the display window. Record the detection results, and calculate the absolute deviation and relative deviation between the average value of the 5 test results using the blood detection system of this example and the test results of the rotational viscometer. Among them, the absolute deviation = the average value of the blood viscosity measured by the test strip - the blood viscosity value measured by the rotational viscometer, and the relative deviation = the absolute deviation / the average value of the blood viscosity measured by the test strip. The specific data are shown in Tables 12 to 16:

[0123] Table 12 Viscosity test results of plasma and 5 venous whole blood samples at 4°C (unit: mPa·s)

[0124]

[0125] Table 13 Viscosity test results of plasma and 5 venous whole blood samples at 10°C (unit: mPa·s)

[0126]

[0127]

[0128] Table 14 Viscosity test results of plasma and 5 venous whole blood samples at 17°C (unit: mPa·s)

[0129]

[0130] Table 15 Viscosity test results of plasma and 5 venous whole blood samples at 23°C (unit: mPa·s)

[0131]

[0132] Table 16 Viscosity test results of plasma and 5 venous whole blood samples at 30°C (unit: mPa·s)

[0133]

[0134] Example 5

[0135] The blood detection system provided in this example is only different from the blood detection system provided in Example 3 as follows:

[0136] The third layer plate of the test strip and the material of the third layer plate are both polycarbonate. The production raw materials of the reagent layer include water-soluble metal salt potassium dihydrogen phosphate, surfactant sodium dodecyl sulfate, water-soluble polymer polyvinylpyrrolidone (PVP), and deionized water. Among them, the mass fraction of potassium dihydrogen phosphate is 10%, the mass fraction of ammonium dodecyl sulfate is 0.1%, and the mass fraction of polyvinylpyrrolidone (PVP) is 2%; the volume of the suction groove is 20 microliters.

[0137] The same detection environmental temperature, plasma and 5 venous whole blood samples as in Example 3 are adopted. The blood detection system of this example is used to test plasma and 5 venous whole blood samples in sequence, and each test condition is tested 5 times. The detection process is only different from the detection process of Example 3 as follows:

[0138] The first DC voltage applied to the first electrode and the second electrode is 50 mV; the second AC voltage applied is 50 mV, with a frequency of 10 Hz and a duration of 10 seconds, obtaining the second electrical signal within 0 - 10 s, that is, the AD value; the microprocessor processes the AD value, selects the AD value within 1 - 10 s and calculates its average value, linearly maps it to a specific interval and then takes the reciprocal to obtain the AD signal processing value x. The processing process is similar to that of Embodiment 3 and will not be elaborated here. The calculation formula in the calculation module of the finally obtained microprocessor is: η = (3.179 * T + 1.9416) * x + (-0.9678 * T + 0.1801).

[0139] Since the detection instrument starts counting down 12 seconds when the test sample is introduced into the suction groove, and the detection result is displayed on the display window. Record the detection results, and calculate the absolute deviation and relative deviation between the average value of the 5 test results of the blood detection system in this embodiment and the test results of the rotational viscometer. Among them, the absolute deviation = the average value of the blood viscosity measured by the test strip - the blood viscosity value measured by the rotational viscometer, and the relative deviation = the absolute deviation / the average value of the blood viscosity measured by the test strip; the specific data are shown in Tables 17 to 21 as follows:

[0140] Table 17 Viscosity test results of plasma and 5 venous whole blood samples at 4°C (unit: mPa·s)

[0141]

[0142] Table 18 Viscosity test results of plasma and 5 venous whole blood samples at 10°C (unit: mPa·s)

[0143]

[0144] Table 19 Viscosity test results of plasma and 5 venous whole blood samples at 17°C (unit: mPa·s)

[0145]

[0146] Table 20 Viscosity test results of plasma and 5 venous whole blood samples at 23°C (unit: mPa·s)

[0147]

[0148] Table 21 Viscosity test results of plasma and 5 venous whole blood samples at 30°C (unit: mPa·s)

[0149]

[0150] As can be seen from the data in Tables 7 to 21, in the range of 4°C to 30°C, for the same blood sample, the relative errors between the viscosity values measured by the blood detection systems of Example 3, Example 4, and Example 5 and the viscosity values measured by a rotational viscometer are all within ±5%. Thus, it can be known that the blood detection system provided by the embodiments of the present invention can obtain accurate measurements of blood viscosity within a relatively wide temperature range, and the measurement time is only a few seconds to more than ten seconds. Compared with a rotational viscometer, the required measurement time is greatly shortened, and the detection efficiency is significantly improved.

[0151] In addition, the blood detection system in Example 3 was used to test 50 blood samples from different sources (including human fingertip blood samples and modulated human blood samples) at room temperature. The readings obtained using the blood detection system in Example 3 were respectively recorded and compared with the high-shear viscosity test values of a rheometer. The results are as Figure 8 shown, demonstrating that the blood detection system provided in this Example 3 has a deviation of within 20% from the rheometer during actual use (clinical), and has a relatively high accuracy.

[0152] Note that the above is only the preferred embodiments of the present invention and the applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein. Various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, it may also include more other equivalent embodiments, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A blood detection system, characterized in that, It includes a detection instrument and a test strip; The detection instrument includes a temperature sensor, a microprocessor, a test strip connection port, and a display window; the test strip includes a third layer board, an electrode layer, a reagent layer, a second layer board, and a first layer board; The blood detection system is used to execute a blood detection method, and the blood detection method includes: S110. Insert the test strip into the detection instrument and start the detection instrument, and apply a first DC voltage to the first electrode and the second electrode of the test strip; S120. Introduce a blood sample into the suction groove of the test strip, connect the first electrode and the second electrode, identify a first current signal through the detection instrument, and record the ambient temperature at this time through the temperature sensor of the detection instrument; S130. After the detection instrument identifies the first current signal, apply a second AC voltage to the first electrode, and the detection instrument detects a second electrical signal of the blood sample after a certain period of time; S140. Process the second electrical signal through the microprocessor of the detection instrument to obtain a processed second electrical signal; S150. Substitute the processed second electrical signal and the ambient temperature into the calculation formula of the blood sample viscosity preset in the microprocessor to calculate the viscosity value of the blood sample; The calculation formula of the blood sample viscosity is: η = (K1 * T + B1)x + (K2 * T + B2); Wherein, η represents the blood viscosity value, T represents the ambient temperature, x represents the processed second electrical signal, and K1, B1, K2, and B2 are all constant coefficients.

2. The system according to claim 1, wherein The production raw material of the reagent layer contains water-soluble metal salts.

3. The system according to claim 2, wherein The production raw material of the reagent layer also includes a surfactant, a water-soluble polymer, and deionized water.

4. The system according to claim 3, wherein The water-soluble metal salts include at least one of sodium chloride, potassium chloride, sodium sulfate, potassium sulfate, potassium carbonate, sodium carbonate, sodium nitrate, potassium nitrate, sodium monohydrogen phosphate, sodium dihydrogen phosphate, potassium monohydrogen phosphate, and potassium dihydrogen phosphate.

5. The system according to claim 4, characterized in that, The production raw material of the reagent layer includes 10% - 30% by mass of water-soluble metal salts, 0.1% - 4% by mass of surfactant, and 2% - 10% by mass of water-soluble polymer.

6. The system according to claim 1, characterized in that, The electrode layer is located above the third layer board, and the reagent layer is located above the electrode layer; the material of the second layer board has adhesiveness and is used to paste the third layer board and the first layer board; a suction groove is provided on the second layer board for accommodating the blood sample.

7. A blood detection method implemented by using the blood detection system according to any one of claims 1-6, characterized in that, It includes: S110. Insert the test strip into the detection instrument and start the detection instrument, and apply a first DC voltage to the first electrode and the second electrode of the test strip; S120. Introduce a blood sample into the suction groove of the test strip, connect the first electrode and the second electrode, identify a first current signal through the detection instrument, and record the ambient temperature at this time through the temperature sensor of the detection instrument; S130. After the detection instrument identifies the first current signal, apply a second AC voltage to the first electrode, and the detection instrument detects a second electrical signal of the blood sample after a certain period of time; S140. Process the second electrical signal through the microprocessor of the detection instrument to obtain a processed second electrical signal; S150. Input the processed second electrical signal and the ambient temperature into the calculation formula of the blood sample viscosity preset in the microprocessor to calculate the viscosity value of the blood sample.

8. The method according to claim 7, characterized in that, The calculation formula of the blood sample viscosity is as follows: η=(K1*T + B1)x+(K2*T + B2); where η represents the blood viscosity value, T represents the ambient temperature, x represents the processed second electrical signal, and K1, B1, K2, and B2 are all constant coefficients.

9. The method according to claim 8, wherein The value range of K1 is 0.5 to 3.0, the value range of B1 is 2.0 to 6.0, the value range of K2 is -1.0 to 0, and the value range of B2 is 0 to 2.

0.

10. The method according to claim 7, wherein The value range of the first DC voltage is 0.1 to 0.8V.

11. The method according to claim 7, wherein The second AC voltage is a low-frequency AC voltage or a high-frequency AC voltage. The peak value range of the second AC voltage is 0.05 to 1V, the frequency range of the second AC voltage is 10 to 1000Hz, and the application time range of the second AC voltage is 1 to 10 seconds.

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