Brain chemical substance analyzer

Abstract

The brain chemical substance analyzer comprises at least one acquisition board, the acquisition board comprises an acquisition microcontroller module, a DAC conversion module, a potentiostat module, a detection module, an amplification filtering module and an ADC conversion module, and the acquisition microcontroller module is electrically connected with a central control board; the detection module obtains a working electrode signal to obtain a detection output signal, the amplification filtering module is electrically connected with the detection module, and the amplification filtering module obtains the detection output signal to obtain an amplification filtering output signal; through cooperation of current and voltage conversion of the multi-level selectable conversion path and three-level amplification of the multi-level selectable conversion path, a suitable path can be flexibly selected for testing according to the use requirements of a test experiment, the test precision can be effectively improved, the electrochemical reaction test in different test environments can be flexibly adapted, and the test efficiency is improved. The test precision can be effectively improved, the noise can be effectively reduced, and the signal is kept stable and accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical substance detection, in particular to a brain chemical substance analyzer. Background Art

[0002] In recent years, the study of the changing patterns of chemical substances in physiological and pathological processes has become a frontier issue that has attracted widespread attention. This is mainly because the information on the real-time changes of chemical substances in living bodies can directly reflect the chemical nature of physiological and pathological processes. For example, the changes in glucose and lactic acid in the brain can directly reflect the energy metabolism process in the brain; glutamate is one of the excitatory neurotransmitters of the central nervous system, and its level in the brain and its changing patterns are directly related to important physiological phenomena such as learning and memory and neuroplasticity.

[0003] Neurotransmitters are a class of specific chemical substances that produce signal transduction between neuronal chemical synapses. After being synthesized in neurons, they are released from the presynaptic membrane and immediately bind to the corresponding postsynaptic membrane receptors to complete the function of neural information transmission. Neurotransmitters are closely related to human health, and play an important role in regulating physiological functions of the body, such as learning, memory, neuronal plasticity, body movement, and brain development. Therefore, conducting research on the detection of neurotransmitter release in the living brain is of great significance for understanding the operating mechanism of the brain, studying the etiology of brain diseases, drug treatment, and basic clinical research.

[0004] The study of chemicals in the brain is inseparable from the detection of chemicals in the brain. Only accurate detection can better understand the performance and use of chemicals. With the development of brain science research, the in situ and precise analysis of neurochemical signals in the brain has gradually received high attention from fields such as neuroscience and analytical chemistry. Electrochemical analysis methods usually have the advantages of high sensitivity, good selectivity, and high temporal and spatial resolution, and are suitable for in situ analysis in vivo. However, the physiological environment of the living body is complex. On the one hand, interference from different neurochemical substances is often encountered during the analysis process, resulting in inaccurate analysis of the concentration of the analyte. On the other hand, many physiological and pathological processes involve the simultaneous changes of multiple neurochemical substances. How to achieve the simultaneous recording of multiple neurochemical substances at the same site is also a challenge faced by in situ electrochemical analysis methods in vivo.

[0005] Fast scan cyclic voltammetry (FSCV) is an in-situ electrochemical analysis method that has been continuously developed and improved in recent decades. This method has a high temporal and spatial resolution and can achieve millisecond-level rapid analysis on a micrometer-level spatial scale. At the same time, it can also achieve qualitative distinction of different analytes based on the difference in the impact of the redox process of different substances on the peak shape of the electrode voltammetric curve. It has the potential to analyze multiple substances simultaneously. As an electrochemical scanning technology that can be used for online detection of chemical substances in the brain, its outstanding advantage is that it has an enrichment effect on the analytes and can increase the size of the detection current. The detection current obtained by detecting chemical substances in the brain needs further processing and analysis, including conversion, compensation, amplification, filtering, etc. In addition, traditional applicable methods include IT (detection current) and CV (detection current) and OCPT (detection voltage).

[0006] However, the above technical solution still has at least the following defects: during the test process, the traditional instrument has a single performance and can only use a fixed single test performance for detection, which greatly limits the measurement range, especially when performing current-voltage conversion and multi-stage amplification. Due to the design of the fixed circuit, the voltage signal obtained by the detection is greatly affected by the experimental environment in the subsequent processing, and cannot adapt to electrochemical reaction tests in different environments. It is also difficult to effectively reduce noise, which makes it difficult to keep the signal stable and accurate, reducing the reliability of the test results. It is difficult to achieve high-precision and rapid detection, and it is impossible to form experimental comparisons in a timely manner. It takes a lot of time to conduct experiments, which is time-consuming and labor-intensive, and the experimental efficiency is low, making it difficult to meet the use requirements of experimental detection. Summary of the invention

[0007] In view of the above situation, in order to overcome the defects of the prior art, the present invention provides a brain chemical substance analyzer, comprising at least one acquisition board, wherein the acquisition board comprises an acquisition microcontroller module, a DAC conversion module, a constant potential instrument module, a detection module, an amplification and filtering module, and an ADC conversion module, wherein the acquisition microcontroller module is electrically connected to a central control board;

[0008] The detection module acquires the working electrode signal to obtain a detection output signal, the amplification and filtering module is electrically connected to the detection module, and the amplification and filtering module acquires the detection output signal to obtain a filter output signal;

[0009] The detection module includes a current detection unit, a voltage detection unit and a path control unit. The path control unit is electrically connected to the current detection unit and the voltage detection unit, respectively. The current detection unit obtains the working electrode signal to obtain a first detection signal, and the voltage detection unit obtains the working electrode signal to obtain a second detection signal; the path control unit obtains the first detection signal or the second detection signal to obtain the detection output signal.

[0010] Further preferably, the current detection unit includes a U3B transimpedance amplifier component, a U2B isolation component and a relay component;

[0011] The DAC conversion module is electrically connected to the U2B isolation component, and the U2B isolation component is electrically connected to the U3B transimpedance amplifier component;

[0012] The acquisition microcontroller module is electrically connected to the relay component, and the relay component is electrically connected to the U3B transimpedance amplifier component;

[0013] The U3B transimpedance amplifier component is electrically connected to the path control unit.

[0014] Further preferably, the voltage detection unit includes a U1B follower component, and the U1B follower component is electrically connected to the path control unit.

[0015] Further preferably, the path control unit includes an electronic switch component, the U3B transimpedance amplifier component and the U1B follower component are electrically connected to the electronic switch component respectively, and the electronic switch component is electrically connected to the acquisition microcontroller module.

[0016] Further preferably, the amplification and filtering module comprises a first-stage program-controlled amplification and filtering unit, a second-stage program-controlled amplification and filtering unit and a third-stage program-controlled amplification unit which are electrically connected in sequence;

[0017] The first-stage programmable amplification and filtering unit receives the detection output signal to obtain a first-stage filter release signal, the second-stage programmable amplification and filtering unit receives the first-stage filter release signal to obtain a second-stage filter release signal, and the third-stage programmable amplification unit receives the second-stage filter release signal to obtain a third-stage amplification signal.

[0018] Further preferably, the first-stage programmable amplification and filtering unit comprises a first-stage amplification component and a first-stage filtering component which are electrically connected in sequence, and the first-stage amplification component is electrically connected to the electronic switch component.

[0019] Further preferably, the secondary programmable amplifying and filtering unit comprises a secondary amplifying component and a secondary filtering component which are electrically connected in sequence, and the secondary amplifying component is electrically connected to the primary filtering component.

[0020] Further preferably, the three-stage programmable amplification unit includes a three-stage amplification component, the two-stage filtering component is electrically connected to the three-stage amplification component, and the three-stage amplification component is electrically connected to the ADC conversion module.

[0021] Further preferably, the constant potentiostat module is electrically connected to the DAC conversion module;

[0022] Wherein, the constant potential instrument module includes a potential unit and an electrode interface unit which are electrically connected in sequence, the electrode interface unit is electrically connected to the electrode wiring, and the electrode interface unit is electrically connected to the detection module.

[0023] Compared with the prior art, the present invention has an ingenious conception. Through the coordinated cooperation of multi-level optional conversion path current-voltage conversion and multi-level optional conversion path three-stage amplification, it can flexibly select the appropriate path for testing according to the use requirements of the test experiment. It can not only effectively improve the test accuracy, flexibly adapt to electrochemical reaction tests in different test environments, greatly increase the testable measurement range, but also effectively reduce noise, keep the signal stable and accurate, improve the reliability of the test results, and achieve high-precision rapid detection. It can also perform independent testing through dual channels, and can do two experiments for comparison at the same time, saving a lot of experimental time, effectively improving experimental efficiency, and being more practical, and better meeting the use requirements of experimental detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the acquisition board of the present invention.

[0025] Figure 2 It is a schematic diagram of the analysis instrument detection of the present invention.

[0026] Figure 3 It is a schematic diagram of the detection module structure of the present invention.

[0027] Figure 4 This is a schematic diagram of the structure of the current detection unit of the present invention.

[0028] Figure 5 It is a circuit diagram of the U2B isolation component and the U3B transimpedance amplifier component of the present invention.

[0029] Figure 6 Schematic diagram of the relay assembly circuit of the present invention.

[0030] Figure 7 It is a schematic diagram of the structure of the voltage detection unit of the present invention.

[0031] Figure 8 It is a schematic diagram of the U1B follower component circuit of the present invention.

[0032] Fig. 9 It is a schematic diagram of the structure of the pathway control unit of the present invention.

[0033] Fig.10 It is a circuit diagram of the electronic switch assembly of the present invention.

[0034] Fig.11 It is a schematic diagram of the structure of the amplification and filtering module of the present invention.

[0035] Fig.12 It is a structural schematic diagram of the first-stage program-controlled amplifying and filtering unit of the present invention.

[0036] Fig.13 It is a circuit diagram of a first-stage amplifying component of the present invention.

[0037] Fig.14 It is a schematic diagram of the circuit of the primary filter component of the present invention.

[0038] Fig.15 It is a structural schematic diagram of the two-stage program-controlled amplification and filtering unit of the present invention.

[0039] Fig.16 It is a circuit diagram of a secondary amplifier assembly of the present invention.

[0040] Fig.17 It is a schematic diagram of the circuit of the secondary filter component of the present invention.

[0041] Fig.18 It is a schematic diagram of the structure of the three-stage program-controlled amplification unit of the present invention.

[0042] Fig.19 It is a schematic diagram of the circuit of the three-stage amplification component of the present invention.

[0043] Fig. 20 It is a schematic diagram of the structure of the potentiostat module of the present invention.

[0044] Fig.21 It is a schematic diagram of a potential unit circuit of the present invention.

[0045] Fig. 22 It is a circuit diagram of the electrode interface unit of the present invention.

[0046] Fig.23 It is a structural schematic diagram of the central control panel of the present invention.

[0047] Fig.24 It is a schematic diagram of the first isolation module circuit of the present invention.

[0048] Fig.25 It is a schematic diagram of the second isolation module circuit of the present invention. DETAILED DESCRIPTION

[0049] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0050] Depend on Figures 1 to 25 It is given that some embodiments of the present invention relate to a brain chemical substance analyzer, comprising at least one acquisition board 1, the acquisition board 1 comprising an acquisition microcontroller module 101, a DAC conversion module 102, a constant potential instrument module 103, a detection module 104, an amplification and filtering module 105, and an ADC conversion module 106, the acquisition microcontroller module 101 being electrically connected to a central control board 4;

[0051] The detection module 104 acquires the working electrode signal to obtain a detection output signal, the amplification and filtering module 105 is electrically connected to the detection module 104, and the amplification and filtering module 105 acquires the detection output signal to obtain a filter output signal;

[0052] The detection module 104 includes a current detection unit 1041, a voltage detection unit 1042 and a pathway control unit 1043. The pathway control unit 1043 is electrically connected to the current detection unit 1041 and the voltage detection unit 1042, respectively. The current detection unit 1041 obtains the working electrode signal to obtain a first detection signal, and the voltage detection unit 1042 obtains the working electrode signal to obtain a second detection signal; the pathway control unit 1043 obtains the first detection signal or the second detection signal to obtain a detection output signal.

[0053] In these embodiments, Figure 1-10 As shown, at least one acquisition board 1 is electrically connected to the chemical substance 3 to be detected through the electrode connection 2 to obtain the working electrode signal of the chemical substance 3 to be detected. In the detection module 104, the working electrode signal (WE) is detected by the current detection unit 1041, and the current-voltage conversion is performed through a multi-level optional conversion path to obtain a first detection signal, wherein the current is converted into a voltage for measurement through a negative feedback circuit composed of an operational amplifier.

[0054] In the detection module 104, the current is converted into voltage through a transimpedance amplifier. The collected current signal has a large noise after the current-voltage conversion. The noise is eliminated through low-pass filtering of multi-level optional paths to keep the signal stable and accurate and meet the low-frequency working requirements.

[0055] Furthermore, the working electrode signal (WE) is detected by the voltage detection unit 1042 to obtain a second detection signal, which is used to detect the voltage change of the chemical substance 3 to be detected, wherein the voltage change is directly measured by the U1B operational amplifier circuit. To prevent circuit noise crosstalk, the present invention uses a dedicated voltage measurement path and selects a high input impedance operational amplifier. The data received from the sensor will not be distorted or degraded due to the connection to the measuring device, ensuring that the signal remains in its original state.

[0056] Since the input range of the ADC conversion module 106 is relatively wide, different electrochemical experimental methods and different solutions and experimental environments will cause significant differences in the reaction current. In order to be able to measure a wider range of currents and improve measurement accuracy, the present invention designs each sensitivity level to use a different path, and each path uses a high-precision feedback resistor.

[0057] It should be understood that operational amplifiers in actual applications will have bias current flowing into the non-inverting input terminal of the operational amplifier, and the frequency response characteristics of the operational amplifier will also change with the change of signal frequency. Therefore, the operational amplifier selected in the present invention has a smaller bias current, a smaller input capacitance, and a flatter frequency response characteristic.

[0058] In the present invention, through the coordinated cooperation of multi-level optional conversion path current-voltage conversion and multi-level optional conversion path three-stage amplification and multi-channel optional low-pass filtering circuits, it is possible to flexibly select a suitable path for testing according to the use requirements of the test experiment, which can not only effectively improve the test accuracy and flexibly adapt to electrochemical reaction tests in different test environments, greatly increase the testable measurement range, but also effectively reduce noise, keep the signal stable and accurate, and improve the reliability of the test results. In addition, independent testing can be performed through dual channels (two acquisition boards 1 operate independently of each other), and two experiments can be compared at the same time, saving a lot of experimental time, effectively improving experimental efficiency, and being more practical, so as to better meet the use requirements of experimental detection.

[0059] In a further embodiment, the current detection unit 1041 performs current-voltage conversion after detecting the working electrode signal, and sends the first detection signal to the subsequent circuit through the path control unit 1043. The voltage detection unit 1042 performs voltage following after detecting the working electrode signal, and sends the second detection signal to the subsequent circuit through the path control unit 1043. The ADC conversion module 106 of the present invention uses a pseudo-differential input method. When common-mode interference is input, it will be subtracted when entering the ADC conversion module 106, thereby ensuring high accuracy of the sampled data.

[0060] The current detection unit 1041 includes a U3B transresistance amplifier component 10411, a U2B isolation component 10412 and a relay component 10413;

[0061] The DAC conversion module 102 is electrically connected to the U2B isolation component 10412, and the U2B isolation component 10412 is electrically connected to the U3B transimpedance amplifier component 10411;

[0062] The acquisition microcontroller module 101 is electrically connected to the relay component 10413, and the relay component 10413 is electrically connected to the U3B transimpedance amplifier component 10411;

[0063] The U3B transimpedance amplifier component 10411 is electrically connected to the path control unit 1043 .

[0064] like Figure 4-6 As shown, the U2B isolation component 10412 is used to receive the analog voltage (VOUTB) sent by the DAC conversion module 102 to ensure that the non-inverting input of the operational amplifier is 0V. Specifically, the U2B isolation component 10412 includes a 1K R94 resistor, a C109 capacitor, a 1K R7 resistor, a C14 capacitor, and a U2B amplifier; the U3B transimpedance amplifier component 10411 is used to receive the working electrode signal (WE) and the output signal (AGND) of the U2B isolation component 10412 FF) and the optional multi-channel signal (E-2—E-9) sent by the relay component 10413. Specifically, the U3B transimpedance amplifier component 10411 includes a U3B op amp, a 0R R8 resistor, a 100R R6 resistor, a 0R R10 resistor, a 100R R14 resistor, a C29 capacitor, a 1K R19 resistor, a C21 capacitor, a 10K R17 resistor, a C19 capacitor, a 100K R13 resistor, a C28 capacitor, a 1M R9 resistor, a C17 capacitor, a 10M R11 resistor, a 100M R12 resistor, a 1000M R15 resistor, and a 0R R5 resistor. The connection relationship of the above components is as follows: Figure 5 As shown, the models of U2B amplifier and U3B amplifier can both be the precision amplifier AD8642ARZ produced by Analog Devices.

[0065] Further, the acquisition microcontroller module 101 controls the path selection of the U3B transimpedance amplifier component 10411 through the relay component 10413, and selects which path to use through the relay component 10413. The relay component 10413 specifically includes K2 signal relay, K3 signal relay, K4 signal relay, K5 signal relay, K5 signal relay, K7 signal relay, K8 signal relay, K9 signal relay, U4 driver, and U22 decoder. The connection relationship of the above components is as follows: Figure 6 As shown, the model of the signal relay can be IM03GR, the brand is TE Connectivity, the model of the U4 driver chip can be the driver chip TBD62083AFNG produced by Toshiba, and the model of the U22 decoder chip can be the decoder chip CD74HC238PWR produced by Texas Instruments (TI).

[0066] In some embodiments of the brain chemical substance analyzer, the voltage detection unit 1042 includes a U1B follower component 10421 , and the U1B follower component 10421 is electrically connected to the pathway control unit 1043 .

[0067] In these embodiments, Figure 7-8 As shown, the detected working electrode signal is sent to the channel control unit 1043 through the U1B follower component 10421. The U1B follower component 10421 specifically includes a 100R R4 resistor, a D1 diode, and a U1B amplifier. The connection relationship of the above components is as shown in Figure 8 As shown, the model of the U1B amplifier can be the high-precision operational amplifier OPA2182 produced by Texas Instruments.

[0068] Through the setting of the above-mentioned voltage follower circuit, a high input impedance can be achieved, and the impact on the signal source is very small. It is very suitable for use as an interface for extracting signals from a high impedance source. The voltage follower has a low output impedance and can drive a lower impedance load while maintaining signal integrity. The low output impedance helps to reduce signal loss and distortion during transmission. The voltage follower circuit does not amplify the signal, that is, the output voltage is equal to the input voltage. It can buffer or isolate the signal source and the load, and can also isolate the input and output, which can effectively avoid interference of the lower-level circuit with the upper-level signal source.

[0069] In some embodiments of the brain chemical substance analyzer, the pathway control unit 1043 includes an electronic switch component 10431, the U3B transimpedance amplifier component 10411 and the U1B follower component 10421 are electrically connected to the electronic switch component 10431, respectively, and the electronic switch component 10431 is electrically connected to the acquisition microcontroller module 101.

[0070] In these embodiments, Figure 9-10 As shown, the electronic switch component 10431 selects the path under the control of the acquisition microcontroller module 101. The electronic switch component 10431 specifically includes a U5 analog switch. The connection relationship of the above components is as follows: Fig.10 As shown, the model of the U5 analog switch may be an analog switch chip ADG1419BRMZ produced by Analog Devices Inc. (Analog Devices Semiconductor Corporation).

[0071] Furthermore, the U5 analog switch is controlled by the acquisition microcontroller module 101, and SA and SB are respectively turned on by the switch and pin 1. When different modes are selected (current detection unit 1041 or voltage detection unit 1042 is selected), the corresponding channel will be opened and then sent to the subsequent circuit through the U5 analog switch.

[0072] In some embodiments of the brain chemical substance analyzer, the amplification and filtering module 105 includes a first-stage programmable amplification and filtering unit 1051, a second-stage programmable amplification and filtering unit 1052, and a third-stage programmable amplification unit 1053 which are electrically connected in sequence;

[0073] The first-stage programmable amplification and filtering unit 1051 receives the detection output signal to obtain a first-stage filter release signal, the second-stage programmable amplification and filtering unit 1052 receives the first-stage filter release signal to obtain a second-stage filter release signal, and the third-stage programmable amplification unit 1053 receives the second-stage filter release signal to obtain a third-stage amplification signal.

[0074] In these embodiments, Fig.11 As shown, the detection output signal is transmitted to the amplification and filtering module 105. In the amplification and filtering module 105, it is amplified step by step by the first-stage programmable amplification and filtering unit 1051, the second-stage programmable amplification and filtering unit 1052 and the third-stage programmable amplification unit 1053, and is gradually transmitted as a first-stage filter signal, a second-stage filter signal and a third-stage amplification signal, and then transmitted to the acquisition microcontroller module 101 through the ADC conversion module 106.

[0075] Furthermore, the amplification and filtering module 105 is connected to the detection module 104, and is used to perform three-stage amplification on the first detection signal obtained by current-voltage conversion in the current detection unit 1041, or to perform three-stage amplification on the second detection signal obtained by voltage following in the voltage detection unit 1042, wherein each stage of amplification is amplified with a multi-level optional path, and the first two stages of amplification are connected to a low-pass filter with a multi-level optional path.

[0076] In the amplification and filtering module 105, a three-stage programmable amplification circuit is used, and each stage of the circuit can select an amplification factor of 1 or 10. During testing, the corresponding path is selected according to the test requirements.

[0077] It should be understood that the amplification path requires a precisely designed feedback network, and the present invention uses high-precision feedback resistors to ensure accurate gain.

[0078] Specifically, each of the first two stages of the program-controlled amplifier circuit is connected to a multi-channel optional low-pass filter circuit. The present invention uses a Sallen-Key second-order low-pass filter, and its noise performance is usually better than that of a pure passive filter. In addition, the Sallen-Key filter requires fewer components, including only two resistors, two capacitors and an operational amplifier. The use of the operational amplifier enhances the performance stability of the filter, and its noise performance is usually better than that of a pure passive filter. A high-order filter is constructed by connecting multiple Sallen-Key second-order units in series.

[0079] Through the synergistic effect of the first-stage programmable amplification and filtering unit 1051, the second-stage programmable amplification and filtering unit 1052 and the third-stage programmable amplification unit 1053, not only the stability of the amplified voltage signal is effectively improved, but the amplified voltage signal can also be filtered and noise reduced at the same time, thereby further improving the accuracy of the amplified voltage signal, and being able to ensure that the amplified signal stably reaches the required amplitude value, effectively reducing the difficulty of realizing high-speed and high-precision amplified voltage signals, better meeting the needs of subsequent detection, and thereby greatly improving the accuracy of chemical substance analysis results, and having higher application flexibility and reducing power consumption costs.

[0080] In some embodiments of the brain chemical substance analyzer, the first-stage programmable amplification and filtering unit 1051 includes a first-stage amplification component 10511 and a first-stage filtering component 10512 which are electrically connected in sequence, and the first-stage amplification component 10511 is electrically connected to the electronic switch component 10431 .

[0081] In these embodiments, Figure 12-14 As shown, the first-stage amplification component 10511 performs optional multi-channel amplification and then performs filtering processing through the first-stage filtering component 10512. The first-stage amplification component 10511 specifically includes R39 resistor, U7A amplifier, R37 resistor, R46 resistor, R40 resistor, R41 resistor, and U20 analog switch. The specific connection method of the above components is as follows Fig.13 As shown, R39 is 1K, the model of U7A amplifier is the high-precision operational amplifier OPA2182 produced by Texas Instruments, R37 is 100R, R46 is NC (NC means no resistor, generally used for early debugging), R40 is 1K, R41 is 10K, and U20 analog switch is ADG1419BRMZ produced by Analog Devices Inc.;

[0082] It is important to understand that Fig.13 In the figure, U20 is an electronic analog switch, and the SA and SB pins are connected to pin 1 respectively. When SA is selected, the gain is -1, and the amplification is 1 times. When SB is selected, the gain is -10, and the signal is amplified 10 times. The left part is the amplifier circuit: there are two amplification paths, which are controlled by U20 to be connected to output pin 1. The input signal AMP_OUT_QZ is amplified to AMP_OUT4. Moreover, U7A, R39, R40, and R41 form a typical inverting amplifier. R39, R40, and R41 are feedback resistors that determine the gain.

[0083] Furthermore, the primary filter component 10512 specifically includes a 0R R16 resistor (for isolation and convenience of early debugging), a 6.19K R25 resistor, an 8.45K R27 resistor, a U21 analog switch, a U7B amplifier, a U8 analog switch, and a 0R R26 resistor (for isolation and convenience of early debugging). The specific connection relationship of the above components is as follows: Fig.14 As shown, the models of U21 analog switch and U8 analog switch are both ADG1408YRUZ chips designed and manufactured by Texas Instruments (TI), and the model of U7B amplifier is OPA2182, a high-precision operational amplifier produced by Texas Instruments (TI).

[0084] It should be understood that through the multi-channel low-pass filter circuit, different filter paths have different cut-off frequencies. U8 and U21 are electronic analog switches, and S1-S8 are controlled by pins 1, 16, and 15. Noise reduction is required before AD acquisition to keep the signal stable and accurate. The present invention uses a Sallen-Key second-order low-pass filter, which usually has better noise performance than a pure passive filter and requires fewer components to build a high-order filter.

[0085] In some embodiments of the brain chemical substance analyzer, the secondary programmable amplification and filtering unit 1052 includes a secondary amplification component 10521 and a secondary filtering component 10522 electrically connected in sequence, and the secondary amplification component 10521 is electrically connected to the primary filtering component 10512.

[0086] In these embodiments, Figure 15-17 As shown, the secondary amplifier component 10521 performs optional multi-channel amplification and then performs optional multi-channel filtering through the secondary filtering component 10522. The secondary amplifier component 10521 specifically includes a 1K R48 resistor, a U28A amplifier, a 100R R36 resistor, an NC R44 resistor (NC means no resistor, disconnected here, and generally used for early debugging), a 10K R50 resistor, a U24 analog switch, an NC R47 resistor, and a 1K R51 resistor. The specific connection method of the above components is as follows: Fig.16 As shown, the model of the U28A amplifier is the high-precision operational amplifier OPA2182 produced by Texas Instruments, and the model of the U24 analog switch is the analog switch chip ADG1419BRMZ produced by Analog Devices Inc. (Analog Devices). The detailed working principle refers to the working principle of the aforementioned first-stage amplifier component 10511;

[0087] Furthermore, the secondary filter component 10522 specifically includes a 6.19K R42 resistor, an 8.45K R43 resistor, a U26 analog switch, a U28B amplifier, a U23 analog switch, a 0R R45 resistor (for isolation and convenience in early debugging), and the specific connection relationship of the above components is as follows: Fig.17 As shown, the models of U26 analog switch and U23 analog switch are both ADG1408YRUZ chips designed and manufactured by Texas Instruments (TI), and the model of U28B amplifier is OPA2182, a high-precision operational amplifier produced by Texas Instruments (Texas Instruments). For detailed working principles, please refer to the working principle of the aforementioned first-stage filter component 10512.

[0088] In some embodiments of the brain chemical substance analyzer, the three-stage programmable amplification unit 1053 includes a three-stage amplification component 10531, the secondary filtering component 10522 is electrically connected to the three-stage amplification component 10531, and the three-stage amplification component 10531 is electrically connected to the ADC conversion module 106.

[0089] In these embodiments, Figure 18-19 As shown, the three-stage amplifier component 10531 performs optional multi-channel amplification and then sends it to the ADC conversion module 106. The three-stage amplifier component 10531 specifically includes a 1K R53 resistor, a U9A amplifier, a 100R R63 resistor, an NC R52 resistor (NC means no resistor, disconnected here, and generally used for early debugging), a 10K R54 resistor, a U27 analog switch, an NC R49 resistor (NC means no resistor, disconnected here, and generally used for early debugging), and a 1K R55 resistor. The specific connection method of the above components is as follows Fig.19 As shown, the model of the U9A amplifier is the high-precision operational amplifier OPA2182 produced by Texas Instruments, and the model of the U27 analog switch is the analog switch chip ADG1419BRMZ produced by Analog Devices Inc.

[0090] In some embodiments of the brain chemical analyzer, the potentiostat module 103 is electrically connected to the DAC conversion module 102;

[0091] The potentiostat module 103 includes a potential unit 1031 and an electrode interface unit 1032 which are electrically connected in sequence. The electrode interface unit 1032 is electrically connected to the electrode connection 2 , and the electrode interface unit 1032 is electrically connected to the detection module 104 .

[0092] In these embodiments, Figure 20-22 As shown, the potential unit 1031 provides a detection voltage to the chemical substance 3 to be detected after receiving the detection analog voltage sent by the DAC conversion module 102, and is connected to the electrode connection 2 through the electrode interface unit 1032 to electrically connect the chemical substance 3 to be detected.

[0093] Potential unit 1031 specifically includes 1K R96 resistor, C113 capacitor, 2.2K R3 resistor, C15 capacitor, U2A amplifier, F1 self-recovery fuse, C4 capacitor, C3 capacitor, 2.2K R2 resistor, 2.2K R1 resistor. The specific connection relationship of the above components is as follows: Fig.21 As shown, the model of the U2A amplifier is the precision amplifier AD8642ARZ produced by Analog Devices, and the model of the F1 resettable fuse is BSMD0603-002-60V, and its brand is BHFUSE.

[0094] It is important to understand that Fig.21 As shown, U2A and the aforementioned U2B (U2B isolation component 10412) are dual operational amplifiers AD8642ARZ, R96 and C113, R3 and C15 respectively form two first-order filters. R1 (2.2kΩ) is located between the output and negative input of the operational amplifier, forming a feedback loop. This resistor and the input resistor R2 together determine the gain of the circuit. The formula for the gain is Gain = R1 / R2, and the gain is 1 in this circuit. F1 is a fuse. When the current passing through the fuse exceeds its rated value, the fuse inside the fuse will melt due to increased heat (the fuse element is usually metal), thereby cutting off the circuit and preventing more current from flowing to protect other components in the circuit from damage. C4 and C3 (both 2.2nF), these capacitors and resistor R2 (2.2kΩ) are connected between the inverting input and output of the operational amplifier. Together with the R2 resistor, they form a feedback network that helps stabilize the gain and reduce high-frequency oscillations. Capacitors C4 and C3 form an RC filter with R2, and the cut-off frequency is about 32.57KHz.

[0095] Furthermore, the electrode interface unit 1032 specifically includes a J3 interface, a J1 interface, and a J2 interface. The specific connection relationship of the above components is as follows: Fig. 22 As shown, the CE and RE signals output by the DAC conversion module 102 are input from the J1 interface and the J2 interface respectively, and are transmitted to the chemical substance to be detected 3 through the electrode connection 2, and the tested working electrode signal (WE) is output from the J3 interface.

[0096] In some embodiments of the brain chemical substance analyzer, the at least two acquisition boards 1 are electrically connected to the central control board 4 respectively, and the central control board 4 includes a first isolation module 401 and a second isolation module 402, the first isolation module 401 is electrically connected to one of the acquisition boards 1, and the second isolation module 402 is electrically connected to another one of the acquisition boards 1.

[0097] In some embodiments of the brain chemical analyzer, the first isolation module 401 includes a U3 isolation component 4011, a U4 isolation component 4012, a J3 protection component 4013, and a J4 protection component 4014, and the second isolation module 402 includes a U5 isolation component 4021, a U6 isolation component 4022, a J5 protection component 4023, and a J6 protection component 4024.

[0098] In these embodiments, Figure 23-25 As shown, the two acquisition boards 1 are connected to the central control board 4 through the first isolation module 401 and the second isolation module 402, respectively, to further improve the protection isolation effect. Specifically, the U3 isolation component 4011 includes a U3 digital isolator, the U4 isolation component 4012 includes a U4 digital isolator, the J3 protection component 4013 includes a J3 electrostatic discharge protector, and the J4 protection component 4014 includes a J4 electrostatic discharge protector; the U5 isolation component 4021 includes a U5 digital isolator, the U6 isolation component 4022 includes a U6 digital isolator, the J5 protection component 4023 includes a J5 electrostatic discharge protector, and the J6 protection component 4024 includes a J6 electrostatic discharge protector. The connection relationship of the above components is as shown in FIG. Figure 24-25 As shown, the model of the electrostatic discharge protector is RCLAMP0524, and the model of the digital isolator is ADUM142D0BRQZ produced by Analog Devices.

[0099] It should be understood that ADUM142D0BRQZ is a digital isolator produced by Analog Devices, which ensures that the accuracy and integrity of the signal are not interfered with and can be used for electrical isolation between circuits. ADUM142D0BRQZ provides digital signal isolation between circuits to prevent high voltage or current interference from affecting sensitive microcontrollers or other logic circuits; ADUM142D0BRQZ contains multiple isolation channels and can isolate multiple digital signals at the same time. RCLAMP0524P.TCT is a circuit protection device produced by Semtech. This device is mainly used to suppress transient voltages and provide circuit protection, especially in the protection of sensitive electronic equipment. It is very effective. It is commonly used to protect high-speed data lines and signal lines from transient voltages such as electrostatic discharge (ESD), cable discharge events (CDE), electrical fast transients (EFT) and lightning-induced voltage surges.

[0100] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A brain chemical substance analyzer, characterized in that The invention comprises at least one acquisition board (1), wherein the acquisition board (1) comprises an acquisition microcontroller module (101), a DAC conversion module (102), a constant potential instrument module (103), a detection module (104), an amplification and filtering module (105), and an ADC conversion module (106); the acquisition microcontroller module (101) is electrically connected to a central control board (4); The detection module (104) acquires the working electrode signal to obtain a detection output signal, the amplification and filtering module (105) is electrically connected to the detection module (104), and the amplification and filtering module (105) acquires the detection output signal to obtain a filter output signal; The detection module (104) includes a current detection unit (1041), a voltage detection unit (1042) and a path control unit (1043). The path control unit (1043) is electrically connected to the current detection unit (1041) and the voltage detection unit (1042), respectively. The current detection unit (1041) obtains the working electrode signal to obtain a first detection signal, and the voltage detection unit (1042) obtains the working electrode signal to obtain a second detection signal; the path control unit (1043) obtains the first detection signal or the second detection signal to obtain the detection output signal.

2. The brain chemical substance analyzer according to claim 1, characterized in that: The current detection unit (1041) comprises a U3B transresistance amplifier component (10411), a U2B isolation component (10412) and a relay component (10413); The DAC conversion module (102) is electrically connected to the U2B isolation component (10412), and the U2B isolation component (10412) is electrically connected to the U3B transimpedance amplifier component (10411); The acquisition microcontroller module (101) is electrically connected to the relay component (10413), and the relay component (10413) is electrically connected to the U3B transimpedance amplifier component (10411); The U3B transimpedance amplifier component (10411) is electrically connected to the path control unit (1043).

3. The brain chemical substance analyzer according to claim 2, characterized in that: The voltage detection unit (1042) includes a U1B follower component (10421), and the U1B follower component (10421) is electrically connected to the path control unit (1043).

4. The brain chemical substance analyzer according to claim 3, characterized in that: The path control unit (1043) comprises an electronic switch component (10431), a U3B transimpedance amplifier component (10411) and a U1B follower component (10421) are electrically connected to the electronic switch component (10431), respectively, and the electronic switch component (10431) is electrically connected to the acquisition microcontroller module (101).

5. The brain chemical substance analyzer according to claim 4, characterized in that: The amplification and filtering module (105) comprises a first-stage program-controlled amplification and filtering unit (1051), a second-stage program-controlled amplification and filtering unit (1052), and a third-stage program-controlled amplification unit (1053) which are electrically connected in sequence; The first-stage programmable amplification and filtering unit (1051) receives the detection output signal to obtain a first-stage filter release signal, the second-stage programmable amplification and filtering unit (1052) receives the first-stage filter release signal to obtain a second-stage filter release signal, and the third-stage programmable amplification unit (1053) receives the second-stage filter release signal to obtain a third-stage amplification signal.

6. The brain chemical substance analyzer according to claim 5, characterized in that: The first-stage programmable amplification and filtering unit (1051) comprises a first-stage amplification component (10511) and a first-stage filtering component (10512) which are electrically connected in sequence, and the first-stage amplification component (10511) is electrically connected to the electronic switch component (10431).

7. The brain chemical substance analyzer according to claim 6, characterized in that: The secondary programmable amplification and filtering unit (1052) comprises a secondary amplification component (10521) and a secondary filtering component (10522) which are electrically connected in sequence, and the secondary amplification component (10521) is electrically connected to the primary filtering component (10512).

8. The brain chemical substance analyzer according to claim 7, characterized in that: The three-stage programmable amplification unit (1053) includes a three-stage amplification component (10531), the two-stage filtering component (10522) is electrically connected to the three-stage amplification component (10531), and the three-stage amplification component (10531) is electrically connected to the ADC conversion module (106).

9. The brain chemical substance analyzer according to claim 1, characterized in that: The constant potential instrument module (103) is electrically connected to the DAC conversion module (102); The constant potential instrument module (103) comprises a potential unit (1031) and an electrode interface unit (1032) which are electrically connected in sequence, the electrode interface unit (1032) is electrically connected to the electrode wiring (2), and the electrode interface unit (1032) is electrically connected to the detection module (104).

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