Detection device, calibration method and control device

Abstract

The application discloses a detection device, a calibration method and a control device, relates to the technical field of detection, and the detection device comprises a sensor, a control circuit, a digital-to-analog converter and a power module. When the control circuit disconnects the external reference voltage provided by the power module to the digital-to-analog converter, the internal reference voltage of the digital-to-analog converter is sampled to obtain a first voltage sampling signal, and the output voltage of the power module is sampled to obtain a second voltage sampling signal. The actual voltage value of the external reference voltage is determined based on the internal preset reference voltage, the first voltage sampling signal and the second voltage sampling signal, and the working parameters of the digital-to-analog converter are configured according to the actual voltage value. After the working parameters are configured, the power module provides the external reference voltage to the digital-to-analog converter. The application aims to improve the instability and temperature drift of the external reference power supply voltage, improve the accuracy of the output voltage of the digital-to-analog converter, and further improve the accuracy and reliability of blood glucose detection.

Description

Technical Field

[0001] The present invention relates to the field of detection technology, and in particular to a detection device, a calibration method and a control device. Background Art

[0002] Continuous glucose monitoring (CGM) systems provide real-time glucose level trends by monitoring interstitial fluid glucose concentrations in the subcutaneous tissue, and have become an essential tool for diabetes management. In CGM products, the digital-to-analog converter (DAC), a core component, converts digital signals into analog signals to precisely control the voltages of the working and reference electrodes. Therefore, the performance of the DAC is directly related to the selectivity and detection accuracy of the electrochemical sensor for glucose. The DAC's reference power supply primarily consists of an external or internal reference power supply. The external reference power supply is typically generated by a low-dropout regulator (LDO) or a DC-DC converter (DC / DC). While flexible and customizable based on specific product requirements, it is subject to individual differences and ambient temperature fluctuations, resulting in large voltage fluctuations that affect the stability of the DAC output voltage. The external reference power supply voltage typically fluctuates by up to ±5%, leading to deviations in the working and reference electrode voltages, which in turn affects the selectivity of the electrochemical reaction for glucose. In contrast, the internal reference power supply has higher precision and lower temperature drift coefficient, and its temperature drift coefficient can usually be as low as ±5ppm / ℃. However, its fixed voltage value has limitations in adapting to different product parameters, making it difficult to meet diverse product design requirements. Summary of the Invention

[0003] The main purpose of the present invention is to provide a detection device, a calibration method and a control device, aiming to improve the instability and temperature drift problems of the external reference power supply voltage, improve the accuracy of the output voltage of the digital-to-analog converter, and thus improve the accuracy and reliability of blood glucose detection.

[0004] To achieve the above object, the present invention provides a detection device, which includes a sensor, a control circuit, a digital-to-analog converter and a power module;

[0005] The power supply module is used to provide an operating voltage to the control circuit and an external reference voltage to the digital-to-analog converter;

[0006] The digital-to-analog converter is used to output the working electrode voltage and the reference electrode voltage to the sensor according to the external reference voltage or the internal reference voltage;

[0007] The control circuit is used to sample the internal reference voltage of the digital-to-analog converter and obtain a first voltage sampling signal, and to sample the output voltage of the power module and obtain a second voltage sampling signal, while disconnecting the external reference voltage provided by the power module to the digital-to-analog converter; determine the actual voltage value of the external reference voltage based on the internal preset reference voltage of the digital-to-analog converter, the first voltage sampling signal, and the second voltage sampling signal, and configure the operating parameters of the digital-to-analog converter according to the actual voltage value of the external reference voltage; after configuring the operating parameters of the digital-to-analog converter, control the power module to provide the external reference voltage to the digital-to-analog converter, so that the digital-to-analog converter outputs the working electrode voltage and the reference electrode voltage based on the configured operating parameters.

[0008] In one embodiment, the digital-to-analog converter has a reference voltage terminal, a configuration terminal, a first voltage output terminal and a second voltage output terminal, and the control circuit has a power supply terminal, an input terminal, an output terminal, a sampling terminal and a communication control terminal;

[0009] Among them, the power supply end and the input end are both electrically connected to the power supply module, the output end and the sampling end are both electrically connected to the reference voltage end, the communication control end is electrically connected to the configuration end, and the first voltage output end and the second voltage output end are electrically connected to the sensor.

[0010] In one embodiment, the control circuit includes:

[0011] Main controller;

[0012] a voltage conversion circuit, wherein an input end of the voltage conversion circuit is electrically connected to the power module, and an output end of the voltage conversion circuit is electrically connected to the main controller;

[0013] The voltage conversion circuit is used to convert the battery voltage of the power module and output a first voltage to the control circuit and the digital-to-analog converter;

[0014] an analog-to-digital conversion circuit, wherein an input end of the analog-to-digital conversion circuit is electrically connected to the digital-to-analog converter, and an output end of the analog-to-digital conversion circuit is electrically connected to the main controller;

[0015] The analog-to-digital conversion circuit is configured to perform analog-to-digital conversion on the internal reference voltage of the digital-to-analog converter and output a corresponding first voltage sampling signal to the main controller, and to sample the first voltage to obtain a second voltage sampling signal;

[0016] a switching circuit, wherein a first end of the switching circuit is electrically connected to the voltage conversion circuit, a second end of the switching circuit is electrically connected to the digital-to-analog converter, and a controlled end of the switching circuit is electrically connected to the main controller;

[0017] The main controller is used to control the switching circuit to be disconnected, so as to obtain a first voltage sampling signal when the external reference voltage provided by the power module to the digital-to-analog converter is disconnected; and determine the actual voltage value of the external reference voltage based on the internal preset reference voltage of the digital-to-analog converter, the first voltage sampling signal and the second voltage sampling signal, and configure the working parameters of the digital-to-analog converter according to the actual voltage value of the external reference voltage; after configuring the working parameters of the digital-to-analog converter, control the switching circuit to be turned on to control the power module to provide the external reference voltage to the digital-to-analog converter, so that the digital-to-analog converter outputs the working electrode voltage and the reference electrode voltage based on the configured working parameters.

[0018] In one embodiment, the control circuit is configured to determine the actual voltage value of the external reference voltage based on the internal preset reference voltage of the digital-to-analog converter, the first voltage sampling signal, and the second voltage sampling signal, including:

[0019] The control circuit is used to determine the actual voltage value of the external reference voltage based on the ratio of the product of the voltage value corresponding to the second voltage sampling signal and the internal preset reference voltage to the voltage value corresponding to the first voltage sampling signal.

[0020] In one embodiment, the control circuit is configured to configure the operating parameters of the digital-to-analog converter according to the actual voltage value of the external reference voltage, including:

[0021] The control circuit is used to configure the register configuration value of the digital-to-analog converter according to the actual voltage value of the external reference voltage.

[0022] In one embodiment, the control circuit is configured to configure the register configuration value of the digital-to-analog converter according to the actual voltage value of the external reference voltage, including:

[0023] The control circuit is used to configure the register configuration value of the digital-to-analog converter according to the ratio of the product of the preset output voltage of the digital-to-analog converter and 2 to the Nth power to the actual voltage value of the external reference voltage, where N is the preset resolution of the digital-to-analog converter.

[0024] In one embodiment, the control circuit is configured to control the power supply module to provide an external reference voltage to the digital-to-analog converter after configuring the operating parameters of the digital-to-analog converter, including:

[0025] The control circuit is used to connect the electrical connection path between the power supply module and the digital-to-analog converter after configuring the working parameters of the digital-to-analog converter, and control the power supply module to provide an external reference voltage to the digital-to-analog converter.

[0026] In one embodiment, the sensor is a blood glucose sensor.

[0027] The present invention also provides a calibration method applied to a detection device, the detection device including a sensor, a control circuit, a digital-to-analog converter, and a power module; the power module is used to provide an operating voltage to the control circuit and an external reference voltage to the digital-to-analog converter; the digital-to-analog converter is used to output a working electrode voltage and a reference electrode voltage to the sensor based on the external reference voltage or the internal reference voltage; the calibration method includes:

[0028] When the external reference voltage provided by the power module to the digital-to-analog converter is disconnected, sampling the internal reference voltage of the digital-to-analog converter to obtain a first voltage sampling signal and sampling the output voltage of the power module to obtain a second voltage sampling signal;

[0029] determining an actual voltage value of the external reference voltage based on an internal preset reference voltage of the digital-to-analog converter, a first voltage sampling signal, and a second voltage sampling signal, and configuring operating parameters of the digital-to-analog converter according to the actual voltage value of the external reference voltage;

[0030] After configuring the working parameters of the digital-to-analog converter, the power supply module is controlled to provide an external reference voltage to the digital-to-analog converter, so that the digital-to-analog converter outputs a working electrode voltage and a reference electrode voltage based on the configured working parameters.

[0031] The present invention further provides a control device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the calibration method described above.

[0032] In actual applications, the ADC sampling is performed twice through the control circuit, and the actual voltage value of the external reference voltage is determined based on the internal preset reference voltage, the first voltage sampling signal, and the second voltage sampling signal, thereby offsetting the influence of temperature on the detection channel. The operating parameters of the analog-to-digital converter are configured based on the actual voltage value of the external reference voltage, so that it outputs the required working electrode voltage and reference electrode voltage. In this way, the instability and temperature drift problems of the external reference power supply voltage are improved. While the power supply module can be flexibly selected according to specific product requirements, the accuracy and reliability of blood glucose testing are also improved. Compared with the factory calibration solution, it reduces costs and improves the market competitiveness of the product and the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0035] Figure 1 A schematic diagram of functional modules provided for an embodiment of a detection device of the present invention;

[0036] Figure 2 A schematic diagram of functional modules provided for another embodiment of the detection device of the present invention;

[0037] Figure 3 A specific circuit diagram provided for an embodiment of the detection device of the present invention;

[0038] Figure 4 A diagram showing the relationship between the internal reference voltage and the power supply voltage provided in an embodiment of the related art;

[0039] Figure 5 A diagram showing the relationship between the internal reference voltage and temperature of a digital-to-analog converter provided in an embodiment of the related art;

[0040] Figure 6 A schematic diagram of a flow chart of an inspection device according to an embodiment of the present invention.

[0041] Description of Figure Numbers:

[0042] 10. Power module; 20. Sensor; 30. Control circuit; 40. Digital-to-analog converter; 31. Main controller; 32. Voltage conversion circuit; 33. Analog-to-digital conversion circuit; 34. Switch circuit.

[0043] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0044] It should be understood that the specific embodiments described herein are merely used to explain the technical solutions of the present invention and are not intended to limit the present invention.

[0045] In order to better understand the technical solution of the present invention, a detailed description will be given below with reference to the accompanying drawings and specific implementation methods.

[0046] It should be noted that in this article, step codes such as S100 and S200 are used for the purpose of expressing the corresponding content more clearly and concisely, and do not constitute a substantial limitation on the order. When implementing the step, those skilled in the art may execute S200 first and then S100, etc., but these should all be within the scope of protection of this application.

[0047] Continuous glucose monitoring (CGM) systems, as key medical devices for real-time monitoring of blood glucose levels, operate by using glucose sensors to detect blood glucose concentrations and transmit real-time data to users or healthcare professionals, providing crucial insights for glucose management in diabetic patients. In CGM systems, the voltages of the working and reference electrodes of the glucose sensor are generated by a digital-to-analog converter (DAC). The accuracy of the DAC output voltage is closely tied to the reference power supply voltage, and the stability of the reference power supply directly determines the reliability of blood glucose measurement results. Specifically, the digital-to-analog converter (DAC), a core component of CGM products, is responsible for converting digital signals into analog signals to precisely control the voltages of the working and reference electrodes. Therefore, the performance of the DAC is directly related to the electrochemical sensor's selectivity for glucose and its detection accuracy.

[0048] There are two main options for the reference power supply of DAC: external reference power supply and internal reference power supply. The external reference power supply is generally generated by a low dropout regulator (LDO) or a DC-DC converter (DC / DC). Although it can be flexibly customized according to specific product requirements, it is affected by individual differences and changes in ambient temperature, resulting in a large voltage fluctuation range, which affects the stability of the DAC output voltage. The external reference power supply voltage fluctuation range can usually reach ±5%. In terms of temperature changes, when the ambient temperature fluctuates between 0-40°C, the voltage drift can be as high as ±3%. In this way, when the DAC parameters are configured according to the set value of the external reference power supply voltage, due to the fluctuation of the voltage output to the DAC, this instability will be directly transmitted to the DAC output voltage, which will cause the working electrode and reference electrode voltages to deviate. The actual voltage value is inconsistent with the working electrode and reference electrode voltages that match the set value of the external reference power supply voltage. This affects the selectivity of the electrochemical reaction to glucose. In contrast, the reference Figure 4 and Figure 5 ,like Figure 5As shown in the figure, different DAC chips have good consistency in their internal reference power supply voltage (reference voltage) under different temperature conditions. The internal reference power supply has higher precision and lower temperature drift coefficient, and its temperature drift coefficient can usually be as low as ±5ppm / ℃. However, its fixed voltage value has limitations in adapting to different product parameters and is difficult to meet the diverse product design requirements. Existing CGM products generally rely on factory calibration to compensate for the deviation of the reference power supply voltage, which is costly.

[0049] For this purpose, refer to Figure 1 , the present invention proposes a detection device, which includes a sensor 20, a control circuit 30, a digital-to-analog converter 40 and a power module 10;

[0050] The power supply module 10 is used to provide an operating voltage to the control circuit 30 and an external reference voltage to the digital-to-analog converter 40;

[0051] A digital-to-analog converter 40 is configured to output a working electrode voltage and a reference electrode voltage to the sensor 20 according to an external reference voltage or an internal reference voltage;

[0052] The control circuit 30 is used to sample the internal reference voltage of the digital-to-analog converter 40 and obtain a first voltage sampling signal, and to sample the output voltage of the power module 10 and obtain a second voltage sampling signal when the external reference voltage provided to the digital-to-analog converter 40 by the power module 10 is disconnected; determine the actual voltage value of the external reference voltage based on the internal preset reference voltage of the digital-to-analog converter 40, the first voltage sampling signal and the second voltage sampling signal, and configure the working parameters of the digital-to-analog converter 40 according to the actual voltage value of the external reference voltage; after configuring the working parameters of the digital-to-analog converter 40, control the power module 10 to provide the external reference voltage to the digital-to-analog converter 40, so that the digital-to-analog converter 40 outputs the working electrode voltage and the reference electrode voltage based on the configured working parameters.

[0053] In this embodiment, the power module 10 can be implemented using a lithium battery, a button battery, etc., and serves as an external reference power supply to provide an external reference voltage for the digital-to-analog converter 40 and an operating voltage for the control circuit 30 .

[0054] In this embodiment, the digital-to-analog converter 40 can be implemented using a DAC chip with an internal reference power supply. The DAC module (digital-to-analog converter 40) is used to generate the reference electrode voltage required by the reference electrode and the working electrode voltage required by the working electrode, and supports switching between the internal reference power supply and the external reference power supply.

[0055] In this embodiment, the control circuit 30 can be implemented using a main controller, such as an MCU (Micro Controller Unit), an FPGA (Field Programmable Gate Array), a PLC (Programmable Logic Controller), a DSP (Digital Signal Processor), or a SOC (System on Chip). The control circuit 30 can include a built-in multi-channel ADC module (analog-to-digital conversion circuit 33) for collecting the internal reference voltage of the digital-to-analog converter 40 and the operating voltage output to the control circuit 30 by the power module 10.

[0056] In this embodiment, the sensor 20 is a blood glucose sensor. Its operating principle is to use an enzyme (such as glucose oxidase or glucose dehydrogenase) to convert glucose in the blood into an electrical signal proportional to the blood glucose concentration. In this embodiment, although continuous glucose monitoring (CGM) systems often rely on tiny electrochemical sensors, they can continuously monitor the glucose concentration in the interstitial fluid of subcutaneous tissues rather than directly measuring glucose in the blood. This allows users to track their blood glucose trends in real time.

[0057] It is understood that when the main controller 31 starts the blood glucose concentration measurement process, the DAC module will output the corresponding working electrode voltage to the working electrode of the glucose sensor and the reference electrode voltage to the reference electrode of the glucose sensor according to the configuration. The ADC module inside the main controller 31 begins to collect the electrical signals generated by the glucose sensor, which are proportional to the glucose concentration in the sample. The main controller 31 MCU receives and processes the data from the ADC module, calculates the corresponding blood glucose concentration value through an internal preset algorithm, and displays the calculated blood glucose concentration value to the user, for example, directly displaying it on the screen of the blood glucose detection device or outputting it to an external terminal to notify the user.

[0058] Assuming the battery voltage of the selected power module 10 is 3V, which is easily affected by temperature and fluctuates, when the DAC module is connected to an external reference voltage, the voltage value of the external reference voltage may not be equal to 3V, and the actual voltage value of the external reference voltage may be 2.8V. In this case, if the operating parameters of the DAC module are configured according to 3V, thereby controlling the output working electrode voltage and reference electrode voltage of the DAC module, the working electrode and reference electrode voltages output by the DAC module to the glucose sensor will be inaccurate, reducing the selectivity of the electrochemical reaction for glucose, thereby affecting the accuracy and reliability of blood glucose detection. Therefore, the present invention configures the operating parameters of the DAC by obtaining the actual voltage value of the precise external reference voltage to output the working electrode voltage and reference electrode voltage that meet the requirements, thereby achieving the purpose of improving the accuracy of blood glucose detection.

[0059] This embodiment takes a complete blood glucose detection cycle as an example to illustrate the working process of the detection circuit of the present invention. When the main controller 31 starts the blood glucose concentration measurement process, the digital-to-analog converter 40 is configured to use its internal reference power supply. At this time, the internal preset reference voltage V1 corresponding to the internal reference power supply is output to the control circuit 30 through the Vref pin of the digital-to-analog converter 40, where V1 is a known value. The ADC module inside the control circuit 30 performs analog-to-digital conversion to obtain a first voltage sampling signal corresponding to the internal reference voltage. The voltage value corresponding to the first voltage sampling signal is recorded as At the same time, the power supply terminal of the control circuit 30 is used to receive the voltage output by the power supply module 10, and the internal integrated ADC module performs analog-to-digital conversion and outputs the corresponding second voltage sampling signal. The voltage value corresponding to the second voltage sampling signal is recorded as Finally, the main controller 31 can be based on 、 , the internal preset reference voltage V1 determines the actual voltage value of the external reference voltage, and configures the operating parameters of the digital-to-analog converter 40 according to the actual voltage value, instead of configuring the operating parameters of the DAC according to the output voltage of the power module 10; after configuring the operating parameters of the digital-to-analog converter 40, the main controller 31 can control the reference voltage of the digital-to-analog converter 40 to switch to the external reference voltage provided by the power module 10 instead of the internal reference voltage. The digital-to-analog converter 40 then outputs the required working electrode voltage and reference electrode voltage based on the configured operating parameters. In this way, the power module 10 with different output voltage values ​​can be flexibly selected according to specific product requirements, and the accuracy of the working electrode voltage and reference electrode voltage can also be ensured.

[0060] In this embodiment, the control circuit 30 is configured to determine the actual voltage value of the external reference voltage based on the internal preset reference voltage of the digital-to-analog converter 40, the first voltage sampling signal, and the second voltage sampling signal, including:

[0061] The control circuit 30 is configured to determine an actual voltage value of the external reference voltage based on a ratio of a product of a voltage value corresponding to the second voltage sampling signal and the internal preset reference voltage to the voltage value corresponding to the first voltage sampling signal.

[0062] It is understandable that the first voltage sampling signal is a digital signal output by the ADC module, and the corresponding voltage value is The second voltage sampling signal is a digital signal output by the ADC module, and the corresponding voltage value .

[0063] The relationship between the voltage value corresponding to the first voltage sampling signal, the voltage value corresponding to the second voltage sampling signal, the internal preset reference voltage, and the actual voltage value of the external reference voltage can be expressed by the following formula (1):

[0064] ;

[0065] in, is the actual voltage value of the external reference voltage; It is the internal preset reference voltage; is the voltage value corresponding to the first voltage sampling signal, is the voltage value corresponding to the second voltage sampling signal. In this way, the actual voltage value of the external reference voltage is:

[0066] .

[0067] It should be noted that since the output digital value of the analog-to-digital converter is proportional to the input analog voltage value, its proportional coefficient is determined by the preset ADC reference voltage and resolution, and the reference voltage and resolution are both known fixed values, so the proportional coefficient is also a fixed value. In this embodiment, since the internal reference power supply voltage V1 of the digital-to-analog converter 40 is not easily affected by temperature, has high precision and small temperature drift, the internal preset reference voltage V1 is an accurate voltage value. The ADC module inside the control circuit 30 first collects the first voltage sampling signal corresponding to the preset reference voltage V1 inside the DAC, and then converts it into a digital signal. The voltage value is Since the external reference voltage provides the operating voltage for the main controller 31, the actual voltage value of the external reference voltage under the current ambient temperature can be collected by the ADC module, and the digital signal can be output after analog-to-digital conversion. Since the two ADC samples use the same ADC module, the above relationship (1) can be established to obtain the actual voltage value of the external reference voltage. In this way, since the output digital value of the ADC module is in direct proportion to the input analog voltage value, the external reference voltage is dynamically calibrated based on the proportional relationship. Calibration is performed before each blood glucose test so that the current temperature can be known before each blood glucose test. , which is the value after the temperature effect on the detection channel is offset, and the accurate working electrode voltage and reference electrode voltage loaded to the glucose sensor by the digital-to-analog converter 40 are obtained.

[0068] In actual applications, the control circuit 30 performs two ADC samplings, determining the actual voltage value of the external reference voltage based on the internal preset reference voltage, the first voltage sampling signal, and the second voltage sampling signal, thereby offsetting the effects of temperature on the detection channel. The operating parameters of the analog-to-digital converter are configured based on the actual voltage value of the external reference voltage, so that it outputs the required working electrode voltage and reference electrode voltage. This improves the instability and temperature drift of the external reference power supply voltage, while allowing for flexible selection of the power module 10 based on specific product requirements, and also enhances the accuracy and reliability of blood glucose testing. Compared to factory calibration solutions, this reduces costs, improves product market competitiveness, and enhances user experience.

[0069] In another embodiment, reference Figure 1 and Figure 2 , the digital-to-analog converter 40 has a reference voltage terminal Vref, a configuration terminal, a first voltage output terminal WE and a second voltage output terminal RE, and the control circuit 30 has a power supply terminal vcc, an input terminal IN, an output terminal OUT, a sampling terminal adc and a communication control terminal;

[0070] Among them, the power supply terminal vcc and the input terminal IN are both electrically connected to the power supply module 10, the output terminal OUT and the sampling terminal adc are both electrically connected to the reference voltage terminal Vref, the communication control terminal is electrically connected to the configuration terminal, the first voltage output terminal WE is electrically connected to the working electrode of the sensor 20, and the second voltage output terminal RE is electrically connected to the reference electrode of the sensor 20.

[0071] In this embodiment, reference Figure 2 , the control circuit 30 includes:

[0072] Main controller 31;

[0073] a voltage conversion circuit 32 , wherein an input end of the voltage conversion circuit 32 is electrically connected to the power module 10 , and an output end of the voltage conversion circuit 32 is electrically connected to the main controller 31 ;

[0074] The voltage conversion circuit 32 is used to convert the battery voltage of the power module 10 and output a first voltage to the control circuit 30 and the digital-to-analog converter 40;

[0075] an analog-to-digital conversion circuit 33 , wherein an input end of the analog-to-digital conversion circuit 33 is electrically connected to the digital-to-analog converter 40 , and an output end of the analog-to-digital conversion circuit 33 is electrically connected to the main controller 31 ;

[0076] The analog-to-digital conversion circuit 33 is used to perform analog-to-digital conversion on the internal reference voltage of the digital-to-analog converter 40 and output a corresponding first voltage sampling signal to the main controller 31, and to sample the first voltage to obtain a second voltage sampling signal;

[0077] a switching circuit 34 , wherein a first end of the switching circuit 34 is electrically connected to the voltage conversion circuit 32 , a second end of the switching circuit 34 is electrically connected to the digital-to-analog converter 40 , and a controlled end of the switching circuit 34 is electrically connected to the main controller 31 ;

[0078] The main controller 31 is used to control the switching circuit 34 to be disconnected, so as to obtain a first voltage sampling signal when the external reference voltage provided by the power module 10 to the digital-to-analog converter 40 is disconnected; and determine the actual voltage value of the external reference voltage based on the internal preset reference voltage of the digital-to-analog converter 40, the first voltage sampling signal and the second voltage sampling signal, and configure the working parameters of the digital-to-analog converter 40 according to the actual voltage value of the external reference voltage; after configuring the working parameters of the digital-to-analog converter 40, control the switching circuit 34 to be turned on to control the power module 10 to provide the external reference voltage to the digital-to-analog converter 40, so that the digital-to-analog converter 40 outputs the working electrode voltage and the reference electrode voltage based on the configured working parameters.

[0079] In conjunction with the above embodiments, the main controller 31 can be implemented using the aforementioned MCU, FPGA, PLC, DSP, etc. The analog-to-digital conversion circuit 33 can be implemented using an analog-to-digital conversion chip, such as a multi-channel ADC module built into the main controller 31. The voltage conversion circuit 32 can be implemented using a low-dropout voltage regulator (LDO), a DC-DC converter, a transformer, etc. In this embodiment, an LDO voltage regulator is used, meaning that the external reference power supply is generated by a low-dropout voltage regulator (LDO).

[0080] In this embodiment, the switching circuit 34 can be implemented by using switching tubes such as triodes, MOS tubes, IGBT tubes, etc., or by using devices such as relays and contactors.

[0081] refer to Figure 3, LDO is the voltage conversion circuit 32, Switch is the switching circuit 34, MCU is the main controller 31, and DAC is the digital-to-analog converter 40. The first end of Switch serves as the input end IN of the control circuit 30 and is electrically connected to the output end of the voltage conversion circuit 32. The second end of the switching circuit 34 serves as the output end of the control circuit 30 and is electrically connected to the reference voltage end Vref of the digital-to-analog converter 40. The controlled end EN of the switching circuit 34 is electrically connected to the IO signal end of the main controller 31. VCC is the power supply end of the control circuit 30. The digital-to-analog converter 40 is communicatively connected to the communication control end of the main controller 31 via the I2C bus. The MCU can output corresponding configuration signals to the digital-to-analog converter 40 via the I2C bus to configure the operating parameters of the digital-to-analog converter 40, so that the digital-to-analog converter 40 outputs the working electrode voltage and the reference electrode voltage based on the configured operating parameters.

[0082] It is understood that the main controller 31MCU can control the on / off state of the switch through the IO signal terminal, thereby determining whether to select the external reference power supply VDD as the reference power supply for the DAC. That is, when the switch is on, the reference voltage of the DAC is the external reference power supply, and when the switch is off, the reference voltage of the DAC is the internal reference power supply V1.

[0083] In this embodiment, when the main controller 31MCU starts the blood glucose concentration measurement process, the digital-to-analog converter 40 is first configured to use its internal reference power supply. The internal preset reference voltage V1 is not easily affected by temperature, and the actual output voltage value is V1. In other words, although the actual output voltage value will fluctuate slightly, it will not cause a large error in the accuracy of blood glucose detection, and the error caused by the fluctuation is within the allowable range. When the external reference voltage provided to the digital-to-analog converter 40 by the power module 10 is disconnected, the corresponding analog signal is output to the main controller 31 through the Vref pin of the digital-to-analog converter 40, and the ADC module samples it and outputs a first voltage sampling signal to the main controller 31, so that the MCU obtains the digital voltage corresponding to the first voltage sampling signal. At the same time, the power supply terminal of the main controller 31 is used to receive the power supply voltage output by the power module 10, and the ADC module performs analog-to-digital conversion and outputs the corresponding second voltage sampling signal to the main controller 31, and the main controller 31 obtains the second digital voltage The MCU uses a preset algorithm to determine the actual voltage value of the external reference voltage based on the internal preset reference voltage of the digital-to-analog converter 40, the first voltage sampling signal, and the second voltage sampling signal, that is, according to formula (1):

[0084] ;

[0085] Calculate the actual voltage value of the external reference voltage , and configure the working parameters of the digital-to-analog converter 40 according to the actual voltage value of the external reference voltage, so that the digital-to-analog converter 40 outputs the working electrode voltage and the reference electrode voltage based on the configured working parameters.

[0086] The internal preset reference voltage V1 of the digital-to-analog converter 40 with higher precision and better temperature drift is used to calibrate the glucose sensor before the electrochemical reaction of the new cycle. The MCU is used to collect the digital voltage corresponding to the internal reference power supply voltage V1 of the DAC chip and the working voltage thereof to obtain the corresponding digital voltage. In this way, the VDD voltage output by the LDO is calibrated using the digital voltage corresponding to the collected reference power supply voltage V1, the digital voltage corresponding to the working voltage thereof and the known internal preset reference voltage to ensure accurate blood glucose measurement before blood glucose measurement. , the operating parameters of the DAC 40 are configured based on the actual voltage value of the external reference voltage, ultimately obtaining the accurate voltages output by the DAC to the working and reference electrodes on the glucose sensor. This precise calibration of the actual value of the external reference power supply ensures flexibility in power supply selection while achieving high-precision detection.

[0087] In one embodiment, the control circuit 30 is configured to configure the operating parameters of the digital-to-analog converter 40 according to the actual voltage value of the external reference voltage, including:

[0088] The control circuit 30 is used to configure the register configuration value of the digital-to-analog converter 40 according to the actual voltage value of the external reference voltage.

[0089] The control circuit 30 is used to configure the register configuration value of the digital-to-analog converter 40 according to the actual voltage value of the external reference voltage, including:

[0090] The control circuit 30 is used to configure the register configuration value of the digital-to-analog converter 40 according to the ratio of the product of the preset output voltage of the digital-to-analog converter 40 and 2 to the power of N to the actual voltage value of the external reference voltage, where N is the preset resolution of the digital-to-analog converter 40.

[0091] In this embodiment, the control circuit 30 can control the DAC module to select the internal reference power supply or the external reference power supply as the reference power supply. The output voltage formula (2) generated by the DAC module is:

[0092] ;

[0093] The following are the meanings of the parameters in the formula:

[0094] External or internal reference / base supply voltage; is the output voltage register configuration value of the digital-to-analog converter 40; N is the preset resolution of the digital-to-analog converter 40, The voltage required for the working electrode and the reference electrode.

[0095] From formula (2), we can see that Too large will cause the output voltage Low precision, if If it is too small, the output voltage will The output range is wide, so the general CGM product will be determined according to the working electrode and reference electrode voltage required by the glucose sensor (determined by the selective response to glucose). ,so An external reference supply voltage is generally used for greater flexibility.

[0096] In this embodiment, since the actual value of the external reference power supply voltage is measured by formula (1), ,at this time is the external reference power supply voltage, that is equal , so substitute into formula (2), since the working electrode and reference electrode voltages required by the detection system are known quantities, a unique register configuration value DAC can be obtained. In this way, the main controller 31 can configure the working parameter DAC of the digital-to-analog converter 40 to ensure that its output is accurate. to the working electrode and reference electrode to meet the detection requirements.

[0097] Using a high-precision, low-temperature drift internal reference voltage V1 within the digital-to-analog converter 40, the MCU samples the internal reference voltage V1 of the DAC chip before a new glucose sensor electrochemical reaction, generating a corresponding first voltage sampling signal. The MCU also samples its own operating voltage VDD and generates a second voltage sampling signal. The actual voltage value of the external reference voltage is determined based on the internal reference voltage, the first voltage sampling signal, and the second voltage sampling signal. In this way, the external reference voltage is calibrated using the internal reference voltage to ensure the exact actual value of the external reference voltage is known before each test. This allows the operating parameters of the digital-to-analog converter 40 to be configured to accurately determine the working electrode voltage and reference electrode voltage output by the analog-to-digital converter to the glucose sensor. This precise calibration of the external reference voltage improves the accuracy of blood glucose testing.

[0098] In one embodiment, the control circuit 30 is configured to control the power module 10 to provide an external reference voltage to the digital-to-analog converter 40 after configuring the operating parameters of the digital-to-analog converter 40, including:

[0099] The control circuit 30 is used to open the electrical connection path between the power module 10 and the DAC 40 after configuring the working parameters of the DAC 40 , and control the power module 10 to provide an external reference voltage to the DAC 40 .

[0100] In combination with the above embodiments, a complete blood glucose detection cycle is used as an example to illustrate the working process of the detection device. When the main controller 31 starts the blood glucose concentration measurement process, the MCU first controls the switching switch circuit 34 to disconnect through the IO port, that is, controls the Switch to disconnect the electrical connection path between the power module 10 and the digital-to-analog converter 40, so as to configure the digital-to-analog converter 40 to use its internal reference power supply. At this time, the internal reference voltage V1 corresponding to the internal reference power supply outputs the corresponding analog signal to the control circuit 30 through the Vref pin of the digital-to-analog converter 40. The ADC module inside the control circuit 30 performs analog-to-digital conversion on the analog signal to obtain a first voltage sampling signal corresponding to the internal reference voltage V1 and outputs it to the main controller 31, which is recorded as At the same time, the power supply terminal of the control circuit 30 is used to receive the power supply voltage output by the LDO module, and the internal integrated ADC module performs analog-to-digital conversion and outputs the corresponding second voltage sampling signal to the main controller 31, which is recorded as ;MCU based on 、 , the internal reference voltage V1 determines the actual voltage value of the external reference voltage, and configures the DAC parameters of the digital-to-analog converter 40 through the I2C bus based on the actual voltage value. After configuring the operating parameters of the digital-to-analog converter 40, the control circuit 30 controls the switch to turn on, switching the reference power supply of the DAC module to the outside, that is, provided by the power supply module 10. In this way, the digital-to-analog converter 40 can output accurate working electrode voltage and reference electrode voltage, and then obtain the electrochemical reaction current value through electrochemical reaction and convert it into a blood glucose concentration value. The blood glucose concentration value is displayed to the user, for example, directly displayed on the screen of the blood glucose detection device or output to an external terminal to notify the user.

[0101] Configuring DAC parameters based on actual voltage values ​​ensures the accuracy and long-term stability of the working electrode and reference electrode voltages subsequently output by the DAC, enhancing the accuracy of electrochemical reaction current measurements and significantly improving the accuracy of blood glucose concentration calculations. Calibration is performed during each measurement cycle, effectively eliminating errors introduced by power supply instability due to temperature, ensuring consistent measurement results across different temperature conditions.

[0102] The present invention also proposes a calibration method, which is applied to the detection device, referring to Figure 6The detection device includes a sensor 20, a control circuit 30, a digital-to-analog converter 40, and a power module 10; the power module 10 is used to provide a working voltage to the control circuit 30 and an external reference voltage to the digital-to-analog converter 40; the digital-to-analog converter 40 is used to output a working electrode voltage and a reference electrode voltage to the sensor 20 according to the external reference voltage or the internal reference voltage; the calibration method includes:

[0103] Step S100: While disconnecting the external reference voltage provided by the power module 10 to the digital-to-analog converter 40, sampling the internal reference voltage of the digital-to-analog converter 40 to obtain a first voltage sampling signal, and sampling the output voltage of the power module 10 to obtain a second voltage sampling signal;

[0104] Step S200, determining an actual voltage value of the external reference voltage based on an internal preset reference voltage of the digital-to-analog converter 40, a first voltage sampling signal, and a second voltage sampling signal, and configuring operating parameters of the digital-to-analog converter 40 according to the actual voltage value of the external reference voltage;

[0105] Step S300: After configuring the working parameters of the DAC 40, control the power supply module 10 to provide an external reference voltage to the DAC 40, so that the DAC 40 outputs the working electrode voltage and the reference electrode voltage based on the configured working parameters.

[0106] In this embodiment, the execution subject of the calibration method may be a processor having data processing and program running functions. When the calibration method is applied to a detection device, the execution subject may be the main controller 31 of the detection device.

[0107] In this embodiment, a complete blood glucose detection cycle is used as an example to illustrate the detection process of the present invention. When the blood glucose concentration measurement process is started, the digital-to-analog converter 40 is configured to use its internal reference power supply. At this time, the internal preset reference voltage V1 corresponding to the internal reference power supply is output to the control circuit 30 through the Vref pin of the digital-to-analog converter 40, where V1 is a known value. The ADC module inside the control circuit 30 performs analog-to-digital conversion to obtain a first voltage sampling signal corresponding to the internal reference voltage. The voltage value corresponding to the first voltage sampling signal is recorded as At the same time, the power supply terminal of the control circuit 30 is used to receive the voltage output by the power supply module 10, and the internal integrated ADC module performs analog-to-digital conversion and outputs the corresponding second voltage sampling signal. The voltage value corresponding to the second voltage sampling signal is recorded as Finally, the main controller 31 can 、 The internal preset reference voltage V1 determines the actual voltage value of the external reference voltage, and configures the operating parameters of the digital-to-analog converter 40 based on the actual voltage value, instead of configuring the DAC operating parameters according to the output voltage of the power module 10. After configuring the operating parameters of the digital-to-analog converter 40, the main controller 31 can control the reference voltage of the digital-to-analog converter 40 to switch to the external reference voltage provided by the power module 10 instead of the internal reference voltage. The digital-to-analog converter 40 then outputs the required working electrode voltage and reference electrode voltage based on the configured operating parameters. The detection device can then perform blood glucose testing, obtain an electrochemical reaction current value through the electrochemical reaction, convert it into a blood glucose concentration value, and display the blood glucose concentration value to the user.

[0108] Self-calibration using an internal, known and stable reference voltage V1 ensures accurate measurement of the external reference voltage, effectively reducing errors caused by external power supply fluctuations, thereby improving the accuracy of the final blood glucose concentration measurement. Automatic calibration and configuration not only reduces the potential for errors introduced by human operators but also improves the adaptability of the detection device in various operating environments. Furthermore, only the internal reference voltage is used during the calibration phase, switching to the external reference voltage when high-precision output is required. This achieves on-demand power supply while improving the accuracy of blood glucose testing.

[0109] The present invention further provides a control device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the calibration method described above.

[0110] The control device provided by the present invention can be the control circuit 30 of the detection device described above. Compared with the prior art, the beneficial effects of the control device provided by the present invention are the same as those of the calibration method provided by the above embodiment, and the other technical features of the control device are the same as those disclosed in the above embodiment method, and are not further described here.

[0111] The above descriptions are only some embodiments of the present invention and are not intended to limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's description and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included in the patent protection scope of the present invention.

Claims

1. A detection device, characterized in that: The detection device includes a sensor, a control circuit, a digital-to-analog converter and a power module; The power supply module is used to provide an operating voltage to the control circuit and an external reference voltage to the digital-to-analog converter; The digital-to-analog converter is used to output the working electrode voltage and the reference electrode voltage to the sensor according to the external reference voltage or the internal reference voltage; The control circuit is configured to, when the external reference voltage provided by the power module to the digital-to-analog converter is disconnected, sample the internal reference voltage of the digital-to-analog converter to obtain a first voltage sampling signal and sample the output voltage of the power module to obtain a second voltage sampling signal; determining an actual voltage value of the external reference voltage based on an internal preset reference voltage of the digital-to-analog converter, the first voltage sampling signal, and the second voltage sampling signal, and configuring operating parameters of the digital-to-analog converter according to the actual voltage value of the external reference voltage; after configuring the operating parameters of the digital-to-analog converter, controlling the power supply module to provide the external reference voltage to the digital-to-analog converter, so that the digital-to-analog converter outputs a working electrode voltage and a reference electrode voltage based on the configured operating parameters; The control circuit is configured to determine the actual voltage value of the external reference voltage based on the internal preset reference voltage of the digital-to-analog converter, the first voltage sampling signal, and the second voltage sampling signal, including: The control circuit is configured to determine an actual voltage value of the external reference voltage based on a ratio of a product of a voltage value corresponding to the second voltage sampling signal and the internal preset reference voltage to a voltage value corresponding to the first voltage sampling signal; The control circuit is used to configure the operating parameters of the digital-to-analog converter according to the actual voltage value of the external reference voltage, including: The control circuit is used to configure the register configuration value of the digital-to-analog converter according to the actual voltage value of the external reference voltage; The control circuit is used to configure the register configuration value of the digital-to-analog converter according to the actual voltage value of the external reference voltage, including: The control circuit is used to configure the register configuration value of the digital-to-analog converter according to the ratio of the product of the preset output voltage of the digital-to-analog converter and 2 to the Nth power to the actual voltage value of the external reference voltage, where N is the preset resolution of the digital-to-analog converter.

2. The detection device according to claim 1, wherein The digital-to-analog converter has a reference voltage terminal, a configuration terminal, a first voltage output terminal and a second voltage output terminal, and the control circuit has a power supply terminal, an input terminal, an output terminal, a sampling terminal and a communication control terminal; Among them, the power supply end and the input end are both electrically connected to the power supply module, the output end and the sampling end are both electrically connected to the reference voltage end, the communication control end is electrically connected to the configuration end, and the first voltage output end and the second voltage output end are electrically connected to the sensor.

3. The detection device according to claim 1, wherein The control circuit comprises: Main controller; a voltage conversion circuit, wherein an input end of the voltage conversion circuit is electrically connected to the power module, and an output end of the voltage conversion circuit is electrically connected to the main controller; The voltage conversion circuit is used to convert the battery voltage of the power module and output a first voltage to the control circuit and the digital-to-analog converter; an analog-to-digital conversion circuit, wherein an input end of the analog-to-digital conversion circuit is electrically connected to the digital-to-analog converter, and an output end of the analog-to-digital conversion circuit is electrically connected to the main controller; The analog-to-digital conversion circuit is configured to perform analog-to-digital conversion on the internal reference voltage of the digital-to-analog converter and output a corresponding first voltage sampling signal to the main controller, and to sample the first voltage to obtain a second voltage sampling signal; a switching circuit, wherein a first end of the switching circuit is electrically connected to the voltage conversion circuit, a second end of the switching circuit is electrically connected to the digital-to-analog converter, and a controlled end of the switching circuit is electrically connected to the main controller; The main controller is used to control the switching circuit to be disconnected, so as to obtain a first voltage sampling signal when the external reference voltage provided by the power module to the digital-to-analog converter is disconnected; and determine the actual voltage value of the external reference voltage based on the internal preset reference voltage of the digital-to-analog converter, the first voltage sampling signal and the second voltage sampling signal, and configure the working parameters of the digital-to-analog converter according to the actual voltage value of the external reference voltage; after configuring the working parameters of the digital-to-analog converter, control the switching circuit to be turned on to control the power module to provide the external reference voltage to the digital-to-analog converter, so that the digital-to-analog converter outputs the working electrode voltage and the reference electrode voltage based on the configured working parameters.

4. The detection device according to claim 1, wherein The control circuit is used to control the power supply module to provide an external reference voltage to the digital-to-analog converter after configuring the working parameters of the digital-to-analog converter, including: The control circuit is used to connect the electrical connection path between the power supply module and the digital-to-analog converter after configuring the working parameters of the digital-to-analog converter, and control the power supply module to provide an external reference voltage to the digital-to-analog converter.

5. The detection device according to claim 1, wherein The sensor is a blood glucose sensor.

6. A calibration method, characterized in that: The detection device according to any one of claims 1 to 5, comprising a sensor, a control circuit, a digital-to-analog converter, and a power module; the power module is configured to provide an operating voltage to the control circuit and an external reference voltage to the digital-to-analog converter; the digital-to-analog converter is configured to output a working electrode voltage and a reference electrode voltage to the sensor based on an external reference voltage or an internal reference voltage; and the calibration method comprises: When the external reference voltage provided by the power module to the digital-to-analog converter is disconnected, sampling the internal reference voltage of the digital-to-analog converter to obtain a first voltage sampling signal and sampling the output voltage of the power module to obtain a second voltage sampling signal; determining an actual voltage value of the external reference voltage based on an internal preset reference voltage of the digital-to-analog converter, a first voltage sampling signal, and a second voltage sampling signal, and configuring operating parameters of the digital-to-analog converter according to the actual voltage value of the external reference voltage; After configuring the working parameters of the digital-to-analog converter, the power supply module is controlled to provide an external reference voltage to the digital-to-analog converter, so that the digital-to-analog converter outputs a working electrode voltage and a reference electrode voltage based on the configured working parameters.

7. A control device, characterized in that: The control device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program is configured to implement the steps of the calibration method according to claim 6 .

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