A high-precision blood sugar detection device

Abstract

The present invention provides a high-precision blood glucose detection device. The technical solution performs detection based on an electrochemical method, and introduces a system error correction term and a temperature compensation mechanism, thereby overcoming the influence of system errors and temperature changes on the detection results to a certain extent. Specifically, the present invention uses a bridge with both positive and negative temperature coefficient thermistor sensors for temperature measurement, and compensates the detection results according to the temperature value during data processing; at the same time, based on a dual-channel input mode, only one blood sample is required to obtain two test results at the same time, and the weighted average of the two results is helpful to eliminate random errors and improve detection accuracy. In addition, at the data processing level, the present invention introduces a dual-channel error feedback mechanism, and when the system deviation is too large, feedback and calibration can be provided in time. The present invention effectively improves the detection accuracy, and has higher temperature sensitivity. At the same time, it has the technical advantages of being easy to carry, easy to use, and low cost.

Description

Technical Field

[0001] The present invention relates to the technical field of medical equipment, and in particular to a high-precision blood sugar detection device. Background Art

[0002] Blood glucose testing is an important technical means to monitor the condition of diabetic patients. Therefore, blood glucose meters are widely used in the daily life of diabetic patients and people with high blood sugar. In terms of detection principle, the common blood glucose meters on the market are mainly divided into two categories: electrochemical testing and light reflection technology testing. The electrochemical method is based on the reaction of enzymes and glucose to produce electrons, and the glucose concentration value is obtained by the magnitude of the current; its advantage is that the price is relatively low, and its disadvantage is that it is easily affected by environmental factors, the electrodes are easily contaminated, and the error is relatively large. After a period of use, it must be calibrated at the maintenance station.

[0003] According to the current national standard: when the blood glucose meter detects blood glucose concentration less than or equal to 4.2nmol / L, the accuracy requirement allows the deviation to not exceed ±0.83nmol / L; when the blood glucose meter detects blood glucose concentration greater than 4.2nmol / L, the accuracy requirement allows the deviation to not exceed ±20%. At present, the test accuracy of home blood glucose meters is generally not high. On the one hand, according to the existing standards, home blood glucose meters have large random errors; on the other hand, blood glucose meters are greatly affected by the environment, especially temperature has a significant impact on blood glucose test results.

[0004] In order to reduce the detection error of the blood glucose meter and improve the detection accuracy, researchers in the prior art have made many attempts. Among them, the Chinese patent "A signal processing circuit, MCU and blood glucose meter" (publication number CN210041762U) provides a signal processing circuit, a microcontroller unit (MCU) and a blood glucose meter. Among them, the signal processing circuit is applied to the blood glucose meter, including: an operational amplifier closed-loop feedback circuit that converts the current signal generated by the blood glucose test strip into an analog voltage signal; an analog-to-digital converter (ADC); a digital-to-analog converter (DAC); wherein the ADC is an ADC that converts the analog voltage signal output by the operational amplifier closed-loop feedback circuit into a digital voltage signal using a first reference voltage and outputs it, and outputs the digital voltage signal to the DAC; the DAC is a DAC that generates a bias voltage using the digital voltage signal output by the ADC and the first reference voltage and inputs it to the non-inverting input terminal of the operational amplifier in the operational amplifier closed-loop feedback circuit. The use of this technical solution can reduce the influence of low-frequency noise on the output signal, improve the accuracy of the output signal, and thus improve the accuracy of the blood glucose meter detection results. However, the technical solution mainly processes to eliminate the influence of the reference voltage on the accuracy of the analog-to-digital converter, without considering the influence of the ambient temperature and system random errors on the blood glucose meter test.

[0005] The Chinese patent "A high-precision measurement circuit for a blood glucose meter" (publication number CN205879765U) provides a high-precision measurement circuit for a blood glucose meter, the circuit comprising: an optical measurement unit, the optical measurement unit comprising a light-emitting element and a light-receiving element; a measuring device body; wherein the measuring device body comprises an analog-to-digital converter, connected to the optical measurement unit and converting the analog signal detected by the optical measurement unit into a digital signal; a control storage unit, connected to the analog-to-digital converter and receiving the digital signal and the status display signal and storing them in the storage unit; a common-mode integrator, connected to the control storage unit and integrating the digital signal and / or the status display signal and outputting the first reference value after integration; the circuit can perform high-precision measurement of the blood glucose value signal through the common-mode integrator and the counter circuit, thereby obtaining an accurate value. Although this technical solution uses light reflection technology to detect blood glucose, compared with the electrochemical method of this patent, its structure is more complicated, which is not conducive to cost control.

[0006] The Chinese patent "A high-precision temperature-compensated blood glucose meter" (publication number CN202903801U) provides a high-precision temperature-compensated blood glucose meter, including a temperature sensor. During measurement, the sensor contacts the test strip directly below the reflection area, and can quickly sense the temperature of the test strip reflection area. The temperature sensor includes a thermistor, and the surface of the thermistor is encapsulated with thermally conductive epoxy resin, and the thermistor is arranged at the front end of the test strip slot. This utility model aims at the shortcomings of existing blood glucose meters. In terms of structural design, it takes into account that the test strip can be in thermal contact with the temperature sensor, so that the temperature of the test strip can be reflected in real time. During measurement, after the test strip is inserted, the sensor will sense the temperature of the test strip. After the test strip temperature is measured, the user is prompted to drop blood for measurement. This technical solution uses an ordinary thermistor to detect the temperature of the blood glucose test strip to reduce the impact of temperature on the measurement results. However, this mode has low temperature sensitivity and lacks feedback correction for system errors, so the detection accuracy still needs to be improved.

[0007] In summary, although some existing technologies have alleviated the problem of large errors in blood glucose meters to a certain extent, overall, their detection accuracy still needs to be improved, the influence of temperature is difficult to fully overcome, and the technical implementation methods also need to be improved. Summary of the invention

[0008] The present invention aims to provide a high-precision blood glucose detection device to address the technical defects of the prior art, so as to solve the technical problem in the prior art that the detection accuracy of conventional blood glucose meters needs to be improved.

[0009] Another technical problem to be solved by the present invention is how to reduce the influence of temperature factors on the detection results as much as possible.

[0010] Another technical problem to be solved by the present invention is how to improve the detection accuracy while giving full consideration to the portability and product cost of the blood glucose meter.

[0011] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0012] A high-precision blood sugar detection device, comprising a temperature detection system, a dual-channel input system, a signal processing system, and a control output system;

[0013] The temperature detection system includes a positive temperature coefficient thermistor sensor, a negative temperature coefficient thermistor sensor, two high-precision resistors, and a Hall sensor, wherein the positive temperature coefficient thermistor sensor, the negative temperature coefficient thermistor sensor, and the two high-precision resistors constitute a bridge circuit, and the Hall sensor detects the current value of the bridge circuit;

[0014] The dual-channel input system includes a blood sampling point, a channel A biological electrode, a channel B biological electrode, and two Hall sensors, wherein the two Hall sensors respectively detect the current values ​​from the channel A biological electrode and the channel B biological electrode, and transmit them to the signal processing system;

[0015] The signal processing system includes an IV conversion circuit, an operational amplifier, a negative feedback circuit, and an AD converter, wherein the IV circuit converts current into a voltage value, the operational amplifier amplifies a small voltage, the negative feedback circuit stabilizes circuit performance, and the AD converter converts the analog voltage value into a digital value and transmits it to the control output system;

[0016] The control output system includes a single-chip microcomputer and a display screen, wherein the single-chip microcomputer receives the detection value from the temperature detection system, obtains the temperature value by looking up the table in the internal ROM of the single-chip microcomputer, and adjusts the temperature influence factor according to the temperature value; the single-chip microcomputer receives data from two AD converters, obtains the blood glucose detection result after weighted averaging; and the single-chip microcomputer controls the display screen for display.

[0017] Preferably, the control output system further comprises a speaker module, and the single chip microcomputer controls the speaker module to play.

[0018] Preferably, the control and transmission system further comprises a system setting module, and the system setting module is used to set the blood glucose meter time or access stored data.

[0019] Preferably, a test strip is further included, wherein the test strip is in contact with a positive temperature coefficient thermistor sensor and a negative temperature coefficient thermistor sensor of the temperature detection system at the same time, and the temperature value obtained by looking up the table is the surface temperature value of the test strip.

[0020] Preferably, the single chip microcomputer is a STC89C51 single chip microcomputer.

[0021] Preferably, the display screen is an LCD12864 liquid crystal display screen.

[0022] Preferably, the single chip receives data from two AD converters, and when the absolute value of the difference between the two blood glucose values ​​is less than the channel error constraint value, the blood glucose detection result is compensated according to the following formula:

[0023] P=(A+B) / 2+αT+ΔS

[0024] Among them, A is the blood glucose value of channel A, B is the blood glucose value of channel B, T is the temperature value, α is the temperature influence factor, and ΔS is the system error correction.

[0025] Preferably, the single chip receives data from two AD converters. When the absolute value of the difference between the two blood glucose values ​​is greater than the channel error constraint value, it counts once and repeatedly collects data from the A bio-electrode and the B bio-electrode. When the number of counts is greater than three times, a reminder is issued and the error is corrected.

[0026] Preferably, a test strip is also included, and the test strip is simultaneously attached to the blood sampling point, the A-path bio-electrode, and the B-path bio-electrode, and the blood flows to the A-path bio-electrode and the B-path bio-electrode respectively through the blood sampling point.

[0027] Preferably, it also includes a body, a display screen is fixedly connected to the front end of the body, and a speaker, a switch and a setting key, an increase key, and a decrease key are respectively arranged on the body.

[0028] The present invention provides a high-precision blood glucose detection device. The technical solution performs detection based on an electrochemical method, and introduces random error elimination, system error correction terms and temperature compensation mechanisms, thereby overcoming the influence of random errors, system errors and temperature changes on the detection results to a certain extent. Specifically, the present invention uses a bridge with both positive and negative temperature coefficient thermistor sensors for temperature measurement, and compensates the detection results according to the temperature value during data processing; at the same time, based on a dual-channel input mode, only one blood sample is required to obtain two test results at the same time, and the weighted average of the two results is beneficial to eliminate random errors and improve detection accuracy. In addition, at the data processing level, the present invention introduces a dual-channel error feedback mechanism, and when the system deviation is too large, feedback and calibration can be provided in time. The present invention effectively improves the detection accuracy, and has higher temperature sensitivity, and has the technical advantages of being easy to carry, easy to use, and low cost.

[0029] Compared with the prior art cited in the background technology, the present invention is essentially different in terms of temperature measurement and current measurement technology. The present invention uses a thermistor sensor with positive and negative temperature coefficients to form an electric bridge to improve the system's sensitivity to temperature changes, which can effectively eliminate the impact of temperature on the test results; it measures blood sugar based on an electrochemical method, which is low in price and easy to use and carry; the electric bridge composed of thermistor sensors with positive and negative temperature coefficients has higher temperature sensitivity.

[0030] In summary, the present invention is a high-precision blood sugar detection device that solves the problem of large errors in measuring blood sugar values ​​in most current blood sugar meters. The device is small in size and easy to use. Its beneficial effects are concentrated in the following aspects:

[0031] 1. Use temperature sensor bridges with positive and negative temperature coefficients to measure the temperature of blood glucose test strips to improve measurement accuracy.

[0032] 2. The dual-channel input system is equivalent to using only one sample to perform two tests at the same time. The weighted average of the results of the two tests is conducive to eliminating random errors and improving detection accuracy.

[0033] 3. The introduction of temperature compensation and system error correction further improves the detection accuracy.

[0034] 4. A dual-path excessive error feedback mechanism has been introduced to provide timely feedback and calibration when the system deviates too much. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 is a circuit diagram of a temperature detection system in the present invention;

[0036] Figure 2 is a structural diagram of a dual-path input system in the present invention;

[0037] Figure 3 It is a hardware system connection relationship diagram of the whole machine of the present invention;

[0038] Figure 4 : is a flow chart of the processing of the test data of the present invention; wherein A is the blood glucose value of channel A, B is the blood glucose value of channel B, C is the count value of the counter, T is the temperature value, P is the final output result, ΔS is the system error correction, α is the temperature influence factor, and ε is the channel error constraint;

[0039] Figure 5 It is the external structure diagram of the present invention;

[0040] In the figure:

[0041] 1. Test strip 2. Blood collection point 3. Bioelectrode A 4. Bioelectrode B

[0042] 5. Body 6. LCD screen 7. Speaker 8. Switch and setting button

[0043] 9. Increase key 10. Decrease key. DETAILED DESCRIPTION

[0044] The specific embodiments of the present invention will be described in detail below. In order to avoid too much unnecessary details, the well-known structures or functions will not be described in detail in the following examples. The approximate language used in the following examples can be used for quantitative expression, indicating that the quantity can be allowed to have a certain change without changing the basic function. Unless otherwise defined, the technical and scientific terms used in the following examples have the same meaning as those generally understood by those skilled in the art to which the present invention belongs.

[0045] A high-precision blood sugar detection device includes a temperature detection system, a dual-channel input system, a signal processing system, and a control output system;

[0046] Temperature detection system: The temperature detection system is mainly used to detect the surface temperature of the blood glucose meter test strip. It consists of 2 thermistor sensors with different temperature coefficients, two high-precision resistors and a Hall sensor. Four resistors R1-R4 form a bridge, in which thermistor sensor R1 has a positive temperature coefficient and thermistor sensor R3 has a negative temperature coefficient. R2 and R4 are high-precision resistors. Hall sensor S1 is used to detect the current of the bridge. According to the current, the surface temperature value of the test strip is obtained, the temperature influence factor is corrected, and the detection accuracy is improved. The temperature measurement on the thermistor sensor with positive and negative temperature coefficients is more accurate than that of a single thermistor sensor. For example Figure 1 shown.

[0047] Dual-channel input system: The dual-channel input system connects the blood collected from the blood sampling point to two pairs of biosensor electrodes A and B for signal processing. S2 and S3 are Hall sensors for current detection in the A and B inputs respectively. The current detected by S2 and S3 is input to the signal processing system respectively. This system can realize two-channel detection and analysis in one blood sampling, avoiding the inconvenience of multiple blood sampling. Figure 2 shown.

[0048] Signal processing system: The system consists of IV conversion circuit, operational amplifier, negative feedback circuit and AD converter. IV circuit is used to convert current into voltage value. Operational amplifier amplifies small voltage, negative feedback circuit is used to stabilize circuit performance, and AD converter converts analog voltage value into digital value for further processing by single chip microcomputer.

[0049] Control output system: This system consists of STC89C51 single-chip microcomputer, LCD12864 liquid crystal display, speaker module, and system setting module. STC89C51 single-chip microcomputer obtains the temperature value through the internal ROM table lookup based on the temperature detection system detection value, and adjusts the temperature influence factor. In order to further improve the detection accuracy of blood sugar, the blood sugar values ​​obtained by the two AD converters are weighted averaged to obtain the final blood sugar value. The single-chip microcomputer controls the LCD display to display and reminds the user of the blood sugar value through the speaker module. The system setting module is mainly used to set the blood sugar meter time or call up stored data.

[0050] The hardware system connection relationship of the blood glucose meter is as follows Figure 3 As shown in Figure 1, the blood glucose meter data processing flow is as follows: Figure 4 As shown, the external structure of the blood glucose meter is as follows Figure 5 shown.

[0051] Working principle: First, set the blood glucose meter through the power on / setting button. The increase and decrease keys can be used to increase and decrease the value and to review the records. When the blood glucose test strip is inserted, the blood glucose meter automatically turns on. The temperature detection module detects the temperature, and the single-chip microcomputer adjusts the temperature influence factor after obtaining the temperature value of the test strip. Blood is collected at the blood sampling point. The blood flows to the A-way bioelectrode and the B-way bioelectrode in two ways. The signal processing module processes the A and B signals. After the single-chip microcomputer receives the two signals, it determines whether the error of the blood glucose test results of A and B exceeds ε. If it does not exceed ε, the two signals are P=(A+B) / 2+α T+ΔS, where (A+B) / 2 can eliminate random errors, α T can be used for temperature compensation, and ΔS is used for system error correction. The final detection value P is output and displayed on the LCD screen, and the blood glucose value of the subject is notified through the speaker. When the error of the blood glucose test results of A and B exceeds ε, the error counter C is judged. If the error is too large for 3 times, a reminder is issued and the error is corrected. Since the whole system uses a bridge with positive and negative temperature coefficients for temperature measurement, the temperature of the test strip can be measured more accurately. Secondly, the final blood glucose value is obtained by weighted average of dual-channel input, which can eliminate the random error of the system. The introduction of system error correction items can overcome system errors, and the introduction of temperature compensation mechanism can overcome the influence of temperature changes on output results. At the same time, the blood glucose meter can perform two tests on the blood glucose meter (dual-channel input) after only collecting blood once, so the blood glucose meter has a higher measurement accuracy.

[0052] The embodiments of the present invention are described in detail above, but the contents are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the scope of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high-precision blood sugar detection device, characterized in that Including temperature detection system, dual-channel input system, signal processing system and control output system; The temperature detection system includes a positive temperature coefficient thermistor sensor, a negative temperature coefficient thermistor sensor, two high-precision resistors and a Hall sensor, wherein the positive temperature coefficient thermistor sensor, the negative temperature coefficient thermistor sensor and the two high-precision resistors constitute a bridge circuit, and the Hall sensor detects the current value of the bridge circuit; The dual-channel input system includes a blood sampling point, a channel A biological electrode, a channel B biological electrode and two Hall sensors, wherein the two Hall sensors respectively detect the current values ​​from the channel A biological electrode and the channel B biological electrode, and transmit them to the signal processing system; The signal processing system includes an IV conversion circuit, an operational amplifier, a negative feedback circuit and an AD converter, wherein the IV circuit converts current into a voltage value, the operational amplifier amplifies a small voltage, the negative feedback circuit stabilizes circuit performance, and the AD converter converts the analog voltage value into a digital value and transmits it to the control output system; The control output system includes a single-chip microcomputer and a display screen, wherein the single-chip microcomputer receives the detection value from the temperature detection system, obtains the temperature value by looking up the table in the internal ROM of the single-chip microcomputer, and adjusts the temperature influence factor according to the temperature value; the single-chip microcomputer controls the display screen to display; The single chip receives data from two AD converters. When the absolute value of the difference between the two blood glucose values ​​is less than the channel error constraint value, the blood glucose test result is compensated according to the following formula: P = (A + B) / 2 + αT + ΔS Among them, A is the blood glucose value of channel A, B is the blood glucose value of channel B, T is the temperature value, α is the temperature influence factor, ΔS is the system error correction, and P is the final detection value; The single-chip microcomputer receives data from two AD converters. When the absolute value of the difference between the two blood glucose values ​​is greater than the channel error constraint value, it counts once and repeatedly collects data from biological electrodes A and B. When the number of counts is greater than three times, a reminder is issued and the error is corrected.

2. A high-precision blood sugar detection device according to claim 1, characterized in that: The control output system also includes a speaker module, and the single chip microcomputer controls the speaker module to play.

3. A high-precision blood sugar detection device according to claim 1, characterized in that: The control output system also includes a system setting module, which is used to set the blood glucose meter time or call up stored data.

4. A high-precision blood sugar detection device according to claim 1, characterized in that: It also includes a test strip, which contacts a positive temperature coefficient thermistor sensor and a negative temperature coefficient thermistor sensor of a temperature detection system at the same time, and the temperature value obtained by looking up the table is the surface temperature value of the test strip.

5. A high-precision blood sugar detection device according to claim 1, characterized in that: The single chip microcomputer is a STC89C51 single chip microcomputer.

6. A high-precision blood sugar detection device according to claim 1, characterized in that: The display screen is an LCD12864 liquid crystal display screen.

7. A high-precision blood sugar detection device according to claim 1, characterized in that: It also includes a test strip, which is attached to the blood sampling point, the A-path biological electrode, and the B-path biological electrode at the same time, and the blood flows to the A-path biological electrode and the B-path biological electrode respectively through the blood sampling point.

8. A high-precision blood sugar detection device according to claim 1, characterized in that: The machine body also includes a display screen fixedly connected to the front end of the machine body, and a speaker, a switch, a setting key, an increase key and a decrease key are respectively arranged on the machine body.

Images