A research platform for olfactory cognitive neurons and a method of use

Abstract

The application provides a research platform and a use method for olfactory cognitive nerve, comprising: an integrated main control and synchronization module for controlling other modules; an olfactory stimulation module for mixing and transmitting test gas; an electroencephalogram acquisition module for testing a subject and acquiring brain wave data; and a data processing and cognitive component analysis module for preprocessing and analyzing the acquired data.The beneficial effect of the application is that the scheme successfully realizes reliable induction and extraction of high-level cognitive components such as oMMN and oP300 through a multi-channel MFC and a built-in cognitive paradigm.On this basis, the double mechanisms of "hardware-level breath synchronization" and "automatic delay compensation" ensure millisecond-level time lock precision, making the latency measurement real and reliable.High-density electroencephalogram combined with an optimized electrode layout provides unprecedented spatial details for revealing the distributed neural network mechanism of olfactory cognition.

Description

Technical Field

[0001] This invention relates to the technical field of olfactory cognitive nerves, and more specifically to a research platform and method for using olfactory cognitive nerves. Background Technology

[0002] Event-related potentials (ERPs) are a method of recording voltage fluctuations in the brain as it processes specific sensory or cognitive events using high-temporal-resolution electroencephalography (EEG). ERP technology is quite advanced in auditory and visual modalities. By designing sophisticated cognitive paradigms (such as the Oddball paradigm and the Go / No-Go paradigm), researchers have successfully induced ERP components closely related to specific cognitive functions, such as mismatch negative waves (MN) reflecting pre-attentional automatic processing mechanisms, and the P300 component reflecting attention allocation and working memory updates. These components have become indispensable objective electrophysiological indicators for studying higher brain functions such as perception, attention, memory, and decision-making.

[0003] However, current technologies and development in olfactory modalities lag significantly behind. As a chemical sense, the presentation and control of olfactory stimuli are far more complex than those of physical stimuli like hearing and vision. This has led to significant long-standing challenges in olfactory ERP (OERP) research, particularly in the study of higher cognitive functions. Currently, existing technical solutions in this field primarily focus on the objective assessment of olfactory sensory pathways, rather than the exploration of cognitive functions. These can be broadly categorized into two main types of similar existing implementations: Option 1: Olfactory pathway detection system based on a single chemical olfactory tincture.

[0004] These systems typically consist of an olfactory stimulator (olfactometer) that controls airflow and odor concentration, along with an electroencephalogram (EEG) acquisition system. The core operating mode involves repeatedly and intermittently presenting the subject with the same chemical odor stimulus (e.g., phenylethanol or isovaleric acid) while simultaneously recording scalp electrical signals using a limited-lead (usually <32 leads) EEG device. The analysis targets early components (e.g., N1, P2) appearing within hundreds of milliseconds after stimulus presentation, which are considered markers of successful activation of the olfactory pathway. The initial design and ultimate application of this approach are limited to assessing the integrity and conduction efficiency of the sensory pathway from the peripheral olfactory epithelium to the central primary olfactory cortex; its main clinical value lies in providing an auxiliary objective diagnosis of anosmia.

[0005] Option 2: A system for mimicking olfaction based on trigeminal nerve electrical stimulation.

[0006] Given the challenges of controlling chemical odors, such as delays, adaptation, and concentration stability, electrical stimulation is used to mimic olfactory perception. This type of system applies a weak current to activate trigeminal nerve endings by placing flexible electrodes inside the nasal cavity to directly stimulate the nasal mucosa, or by stimulating the skin of the nasal bridge with surface-mounted electrodes, inducing a non-specific sensation (such as tingling, coolness, or vibration). It is also combined with limited-lead EEG recording of the response potentials to electrical stimulation. The goal of this approach is to assess the functional status of the trigeminal nerve, a somatosensory neural pathway.

[0007] As can be seen from the above solutions, the main problems with the existing solutions include: 1. The singularity and non-physiological nature of the stimulus modal make it impossible to construct an effective cognitive research paradigm, resulting in low ecological validity and functional specificity.

[0008] Taking Scheme 1 as an example, it can only provide a chemical odor stimulus and cannot form a contrast sequence of "frequent standard stimuli" and "rare biased stimuli" in experiments. Therefore, it is impossible to apply it to cognitive paradigms such as Oddball and Go / No-Go, which have been proven to be extremely effective in auditory / visual ERPs. Scheme 2, on the other hand, uses non-chemical electrical stimulation, and its physical mechanism is completely different from the binding of odor molecules to olfactory receptors.

[0009] The problem arising from the above is that existing technologies can only induce EEG components reflecting primary sensory processing (such as N1 and P2), but are completely unable to induce specific ERP markers directly related to higher cognitive functions (such as pre-attentive memory comparison, intentional attention, and decision-making), such as mismatch negative waves (MMN) and P300. The phenomenon studied in Scheme 2 is unrelated to true olfactory cognitive processing; the trigeminal somatosensory response it elicits severely confuses and masks weak olfactory-specific signals, resulting in extremely poor ecological validity and functional specificity. Therefore, the existing technological system is trapped at the "sensory" level and cannot rise to the dimension of "cognitive" research.

[0010] 2. Due to insufficient spatial resolution of the EEG acquisition system, it is impossible to accurately locate the activity of brain regions related to olfactory cognition.

[0011] Current EEG systems generally employ limited-lead (<32 leads) connections. These systems have low electrode density and are concentrated in the mid-scalp (e.g., Cz, Pz points). However, the core brain regions known for higher-level olfactory cognitive processing (such as odor recognition, memory, and emotional valence assessment) (e.g., the orbitofrontal cortex, prefrontal cortex, and anterior insula) are located in the anterior and temporal regions of the scalp, and their signals are relatively weak and distributed. Low-density EEG spatial sampling is insufficient to effectively capture and separate the activity signals of these deep, distributed brain networks. Consequently, even if some responses are induced, limited-lead EEG cannot effectively perform source localization analysis of cognitive ERP components, greatly limiting the interpretation and application value of the data's deeper meaning and failing to answer the crucial scientific question of "where does olfactory cognitive processing occur?"

[0012] 3. Due to the independence and lack of deep integration between systems, the accuracy of time synchronization and the depth of data analysis are limited.

[0013] Current technologies typically treat olfactory stimulators, respiratory synchronizers, and EEG devices as multiple independent devices, simply connected by cables. Clock drift and communication delays exist between these devices, and chemical stimulation inherently has tubular transmission delays, resulting in uncompensated, variable time errors between the potentials recorded by EEG and the actual cognitive processing. For cognitive components such as the MMN and P300, which heavily rely on precise latency for interpretation, this uncompensated systematic error introduces significant noise, leading to poor reliability and repeatability of measurement results, making them unsuitable for rigorous scientific analysis and accurate cross-modal comparisons. Furthermore, the data streams are independent, lacking a unified software platform to integrate and automate the entire process from paradigm presentation to EEG analysis. Summary of the Invention

[0014] This invention overcomes the shortcomings of the prior art and provides a research platform and method for using olfactory cognitive neurons.

[0015] The objective of this invention is achieved through the following technical solution.

[0016] A research platform for olfactory cognitive neurons includes: An integrated main control and synchronization module is used to control other modules; The olfactory stimulation module is used for mixing and transporting the test gas; The EEG acquisition module is used to collect the subject's brainwave data; The data processing and cognitive component analysis module is used to preprocess and analyze the collected data.

[0017] The integrated main control and synchronization module includes: The main control computer is used to control and monitor the overall platform. The central synchronizer is used to connect to the main control computer. The central synchronizer has a built-in delay compensation unit and is connected to the respiratory sensor, the stimulation control unit and the EEG marker unit respectively. The delay compensation unit is used to eliminate the time offset caused by odor transmission and ensure that the trigger signal is strictly aligned with the actual odor stimulus in time. A breathing sensor is used to receive airflow signals from the subject's nasal cavity; The stimulation control unit is used to send drive commands to the olfactory stimulation module through the digital I / O port; The EEG tagging unit is used to connect to the EEG acquisition module circuit. The EEG tagging unit is connected to the amplifier trigger input port circuit of the EEG acquisition module through a cable to directly send TTL synchronization signals.

[0018] The specific working steps of the delay compensation unit are as follows: A1. When the main control computer issues a stimulus trigger command, the command time is recorded as t1; A2. Determine whether the gas concentration detected by the gas sensor in the breathing sensor has reached the 50% peak value in real time. If the determination is yes, record the arrival time as t2. A3. Calculate the fixed transmission delay time Δt = t2 - t1; A4. Store Δt. In subsequent data analysis, use Δt to perform delay correction on the time point when the main control computer issues the stimulus trigger command. A5. Terminate the process.

[0019] The olfactory stimulation module includes: Air source, used to provide clean compressed air; There are multiple independent gas paths, each of which is connected to a gas source and a corresponding odorant transmission device to transmit carrier gas, standard odorant, and deviated odorant. Mass flow controllers (MFCs) are installed on each independent gas path to receive analog signals from the central synchronizer and control the instantaneous flow rate of each independent gas path, thereby achieving online dynamic dilution of concentration. High-speed solenoid valves are located downstream of each independent olfactory transmission gas path and are used to receive TTL commands from the central synchronizer to control the opening and closing of the corresponding independent gas path. The gas mixing chamber is interconnected with each independent gas path and is used to mix the gases transmitted in each gas path; The temperature and humidification unit is located in the gas mixing chamber and is used to control the temperature and humidification of the mixing chamber and its output pipeline. The activated carbon filter and vacuum pump are connected to each independent gas path and are used to start the vacuum pump during the stimulation interval to quickly draw out residual odor molecules and purify them through the activated carbon filter to ensure no odor background.

[0020] The EEG acquisition module is connected to the central synchronizer circuit to receive synchronization marker signals from the central synchronizer. The EEG acquisition module is also connected to the data processing and cognitive component analysis module to transmit the raw EEG data acquired by the EEG acquisition module to the processing module for data processing.

[0021] The EEG acquisition module has an electrode sampling area in the forehead region of the scalp. This sampling area covers the corresponding scalp regions within the Fp, AF, and F series location areas in the international standard EEG electrode positioning system. The EEG acquisition module has an electrode sampling area in the anterior temporal region, which covers the bilateral anterior temporal scalp area where FT7 and FT8 are located in the international standard EEG electrode localization system. Multiple electrodes are arrayed in the electrode sampling area of ​​the forehead and anterior temporal regions of the scalp, with a spacing of less than or equal to 2 cm between each electrode.

[0022] The specific data processing steps of the data processing and cognitive component analysis module are as follows: B1. Data preprocessing: bandpass filtering of the raw EEG data in the range of 0.1-30 Hz and removal of physiological artifacts. B2. Delay Compensation and Segmentation: The embedded markers in the EEG data are read, and the time points after time compensation for all markers are calculated. The formula for calculating the compensated time points is as follows: t_corrected = t_original - Δt In the formula, t_corrected is the time point after compensation; t_original is the marking time; Δt is the fixed transmission delay time; and the marking time is the time point when the central synchronizer sends the TTL trigger marking to the EEG acquisition module. B3. Based on the compensated time point, extract the EEG segments from 200ms before stimulation to 800ms after stimulation from the EEG data. B4. Baseline correction is performed on each EEG segment extracted in B3. The mean EEG signal 200 ms before stimulation is used as the baseline. The mean baseline is subtracted from the signal amplitude at each time point in the segment to eliminate the influence of baseline drift on the EEG signal. After baseline correction is completed, the EEG segments are grouped according to the stimulation type. All single-test EEG segments corresponding to the same stimulation type are superimposed and averaged.

[0023] The cognitive analysis extraction algorithms in the data processing and cognitive component analysis module include: olfactory mismatch negative wave oMMN extraction and olfactory oP300 extraction. When extracting the olfactory mismatch negative wave oMMN, under non-attentional conditions, the deviation stimulus ERP is subtracted from the standard stimulus ERP, and the negative component of the difference wave that appears within a time window of 150-250 ms is taken as the olfactory mismatch negative wave oMMN. When olfactory oP300 is extracted, under active attention task, the biased stimulus ERP is directly observed, and the positive components appearing within the 250-500 ms time window are taken as olfactory oP300.

[0024] The method of using a research platform for olfactory cognitive neurons includes the following specific steps: S1. Issue the experiment start command through the main control computer; S2, The central synchronizer continuously monitors the signals from the respiratory sensor; When a valid breath is detected at the start of the inspiratory phase, the central synchronizer performs the following operations synchronously. Send commands to the MFCs and solenoid valves of the olfactory stimulation module to release preset odor stimuli; Send a TTL trigger flag to the amplifier in the EEG acquisition module; S3, the EEG acquisition module records EEG data with TTL trigger markers; S4. After the experiment, the data collected by the EEG acquisition module is transmitted to the data processing and cognitive component analysis module for analysis.

[0025] The beneficial effects of this invention are as follows: This solution successfully achieves reliable induction and extraction of advanced cognitive components such as oMMN and oP300 through multi-channel MFC and built-in cognitive paradigms. Based on this, the dual mechanisms of "hardware-level respiratory synchronization" and "automatic delay compensation" ensure millisecond-level time-locking accuracy, making latency measurements truly reliable. High-density EEG combined with optimized electrode layout provides unprecedented spatial detail for revealing the distributed neural network mechanism of olfactory cognition.

[0026] In summary, this invention constructs a standardized and integrated research platform, effectively providing a complete and standardized solution from stimulus control, paradigm design, data acquisition to analysis processes, greatly reducing the research threshold and improving the reliability and reproducibility of results. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the working principle of the present invention; Figure 2 This is a schematic diagram of the working principle of the integrated main control and synchronization module; Figure 3 This is an example diagram showing the working results of the delay compensation unit in this embodiment; Figure 4 This is a diagram showing the electrode setup for the EEG acquisition module; In the diagram: 1. Integrated main control and synchronization module; 101. Main control computer; 102. Central synchronizer; 103. Respiratory sensor; 104. Stimulation control unit; 105. EEG labeling unit; 2. Olfactory stimulation module; 3. EEG acquisition module; 4. Data processing and cognitive component analysis module; Detailed Implementation

[0028] The technical solution of the present invention will be further described below through specific embodiments.

[0029] Example like Figure 1 As shown, a research platform for olfactory cognitive neurons includes: Integrated main control and synchronization module 1 is used to control other modules; Olfactory stimulation module 2 is used for mixing and transporting the test gas; EEG acquisition module 3 is used to acquire the subject's brain wave data; The data processing and cognitive component analysis module 4 is used to preprocess and analyze the collected data.

[0030] Preferably, the main control computer stores a control system, including: The experimental paradigm configuration module, stimulation parameter management module, real-time control and triggering module, and data monitoring and recording module work together to achieve unified control over the olfactory stimulation and EEG acquisition process.

[0031] The experimental paradigm configuration module is used to define olfactory cognition experimental paradigms through a graphical user interface. Its configuration content includes at least the following: (1) Identification of the stimulation type corresponding to different olfactory substances.

[0032] (2) Presentation probability parameters for each stimulus type (e.g., the probability ratio of standard stimuli to biased stimuli).

[0033] (3) Stimulus duration, stimulus interval and randomization range.

[0034] (4) Whether to enable the subject task conditions (such as attention or non-attention paradigm).

[0035] The experimental paradigm configuration module is used to generate a structured paradigm instruction sequence from the above parameters.

[0036] The stimulus parameter management module is used to convert abstract stimulus configuration parameters into executable hardware control parameters according to the paradigm instruction sequence. The hardware control parameters include at least: (1) Target flow value corresponding to each mass flow controller.

[0037] (2) The opening / closing sequence of each solenoid valve.

[0038] (3) Selection signals for each olfactory channel. This module sends hardware control parameters to the central synchronizer 102, which performs hardware-level control.

[0039] The real-time control and triggering module is used to communicate bidirectionally with the central synchronizer 102 during the experimental operation. After receiving the respiratory synchronization trigger event, it sends the stimulus execution command to the central synchronizer 102 in the time sequence of the paradigm command sequence, and synchronously generates the tag information corresponding to the stimulus type.

[0040] The data monitoring and recording module is used to display the system's operating status in real time during the experiment, including airflow parameters, stimulation status, respiratory synchronization status, and EEG acquisition status. It also records the experimental configuration parameters, stimulation trigger timestamps, and labeling information in a unified manner for subsequent EEG data processing and analysis.

[0041] like Figure 2 As shown, the integrated main control and synchronization module 1 includes: The main control computer 101 is used to control and monitor the overall platform; The central synchronizer 102 is used to connect to the main control computer 101. The central synchronizer 102 has a built-in delay compensation unit. The central synchronizer 102 is connected to the respiratory sensor 103, the stimulation control unit 104 and the EEG tagging unit 105 respectively. The delay compensation unit is used to eliminate the time offset caused by odor transmission and ensure that the trigger signal is strictly aligned with the actual odor stimulus in time. The breathing sensor 103 is used to receive airflow signals from the subject's nasal cavity. The breathing sensor calculates the slope (dv / dt) of the signal in real time through an algorithm embedded in the FPGA. When the slope exceeds a preset threshold, a trigger event is generated at the moment of the start of the inspiratory phase (<1ms accuracy). The stimulation control unit 104 is used to send drive commands to the olfactory stimulation module 2 through the digital I / O port; EEG tagging unit 105 is used to connect to the EEG acquisition module 3 circuit. EEG tagging unit 105 is connected to the amplifier trigger input port circuit of EEG acquisition module 3 through a cable and directly sends TTL synchronization signal.

[0042] The specific working steps of the delay compensation unit are as follows: A1. When the main control computer 101 issues a stimulus trigger command, the command time is recorded as t1; A2. Determine whether the gas concentration detected by the gas sensor in the breathing sensor 103 has reached the 50% peak value in real time. If the determination is yes, record the arrival time as t2. A3. Calculate the fixed transmission delay time Δt = t2 - t1; A4. Store Δt. In subsequent data analysis, use Δt to perform delay correction on the time point when the main control computer 101 issues the stimulus trigger command. A5. Terminate the process.

[0043] The function of the delay compensation unit is to read a fixed transmission delay time Δt during the subsequent analysis of olfactory event-related potential data, and to use this Δt to correct the timing of the stimulus events recorded in the EEG data.

[0044] Specifically, without delay compensation, the timing of the stimulus event marker in the EEG data corresponds to the time t1 when the stimulus trigger command is issued, while the actual time for the olfactory stimulus to reach the subject's nasal cavity is t2. Since there is a fixed physical delay in gas transmission, directly using t1 as a time reference will systematically delay the latency of olfactory event-related potentials.

[0045] Therefore, when performing EEG data segmentation and superposition averaging, the time reference point of the stimulus event is corrected from t1 to t2, that is, the event time axis is shifted and corrected by introducing the fixed transmission delay Δt.

[0046] Under this correction method, the latency of the obtained olfactory event-related potentials corresponds to the actual neural response time after the olfactory stimulus actually acts on the subject's olfactory system, thereby improving the temporal accuracy and comparability of data under different experimental conditions and different system configurations.

[0047] like Figure 3 As shown, taking Δt=80ms and the initial measurement of oERP=300ms as an example, the corrected data should be oERP=220ms.

[0048] Olfactory stimulation module 2 includes: Air source, used to provide clean compressed air; There are multiple independent gas paths, each of which is connected to a gas source and a corresponding odorant transmission device to transmit carrier gas, standard odorant, and deviated odorant. Mass flow controllers (MFCs) are installed on each independent gas path to receive analog signals from the central synchronizer 102, control the instantaneous flow rate of each independent gas path, and realize online dynamic dilution of concentration. A high-speed solenoid valve is located downstream of each independent odor transmission gas path and is used to receive TTL commands from the central synchronizer 102 to control the opening and closing of the corresponding independent gas path; preferably, the response time of the high-speed solenoid valve is less than 10ms.

[0049] The gas mixing chamber is interconnected with each independent gas path and is used to mix the gases transmitted in each gas path; The temperature and humidification unit is located in the gas mixing chamber and is used to control the temperature (37±0.1°C) and humidification of the mixing chamber and its output pipeline; to ensure the stability of the physical parameters of the stimulating gas and avoid trigeminal nerve interference.

[0050] The activated carbon filter and vacuum pump are connected to separate gas lines. During the stimulation interval, the vacuum pump is activated to quickly draw out residual odor molecules and purify them through the activated carbon filter to ensure no odor background.

[0051] The EEG acquisition module 3 is connected to the central synchronizer 102 circuit to receive the synchronization marker signal from the central synchronizer 102. The EEG acquisition module 3 is also connected to the data processing and cognitive component analysis module 4 circuit to transmit the raw EEG data acquired by the EEG acquisition module 3 to the processing module for data processing.

[0052] like Figure 4 As shown, the EEG acquisition module has an electrode sampling area in the forehead region of the scalp. This electrode sampling area covers the corresponding scalp regions within the Fp, AF, and F series location areas in the international standard EEG electrode positioning system. The EEG acquisition module has an electrode sampling area in the anterior temporal region, which covers the bilateral anterior temporal scalp area where FT7 and FT8 are located in the international standard EEG electrode localization system. Multiple electrodes are arrayed in the electrode sampling area of ​​the forehead and anterior temporal regions of the scalp, with a spacing of less than or equal to 2 cm between each electrode.

[0053] Current EEG acquisition systems typically employ the international 10-20 electrode localization system. This system distributes electrodes proportionally according to the anatomical proportions of the scalp, and its structural characteristic is that the electrode spacing in each region remains basically uniform. However, due to the limited number of electrodes in the forehead and anterior temporal regions caused by this uniform distribution structure, the spatial sampling spacing in these areas is usually greater than 4 cm, resulting in insufficient spatial sampling resolution for the forehead and anterior temporal scalp regions related to olfactory cognition.

[0054] Based on international standard electrode positioning rules, this invention optimizes the layout of the forehead and anterior temporal regions of the scalp by increasing the electrode density in these regions, so that the electrode spacing in these regions is less than or equal to 2 cm and less than the average electrode spacing of the entire head.

[0055] By using the aforementioned regionally differentiated spatial sampling structure, the spatial sampling resolution of scalp regions related to olfactory cognition is improved while maintaining the overall integrity of scalp coverage. This enhances the signal detection capability of olfactory event-related potential components and provides higher-density spatial data support for subsequent source localization analysis.

[0056] Unlike high-density EEG systems that achieve uniform encryption across the entire head simply by increasing the total number of leads, this invention creates localized high-density sampling bands within specific functionally relevant regions, rather than a simple overall uniform and dense arrangement. This regionally targeted encryption structure tilts spatial sampling resources toward olfactory cognition-related brain regions, thereby achieving more efficient spatial sampling of target functional areas under the same or similar lead count conditions.

[0057] The specific data processing steps in Module 4 of Data Processing and Cognitive Component Analysis are as follows: B1. Data preprocessing: bandpass filtering of the raw EEG data in the range of 0.1-30 Hz and removal of physiological artifacts. B2. Delay Compensation and Segmentation: The embedded markers in the EEG data are read, and the time points after time compensation for all markers are calculated. The formula for calculating the compensated time points is as follows: t_corrected = t_original - Δt In the formula, t_corrected is the time point after compensation; t_original is the marking time; Δt is the fixed transmission delay time; and the marking time is the time point when the central synchronizer 102 sends the TTL trigger marking to the EEG acquisition module 3. B3. Based on the compensated time point, extract the EEG segments from 200ms before stimulation to 800ms after stimulation from the EEG data. B4. Baseline correction was performed on each EEG segment extracted in B3. The mean EEG signal value 200 ms before stimulation was used as the baseline. The mean baseline value was subtracted from the signal amplitude at each time point in the segment to eliminate the influence of baseline drift on the EEG signal. After baseline correction, the EEG segments were grouped according to the stimulation type. All single-trial EEG segments corresponding to the same stimulation type were superimposed and averaged. This process was used to suppress random noise in the EEG signal, highlight the olfactory event-related potential characteristics associated with the stimulation type, and provide a clear and reliable EEG data foundation for subsequent cognitive component analysis.

[0058] The cognitive analysis extraction algorithm in the data processing and cognitive component analysis module 4 includes: olfactory mismatch negative wave oMMN extraction and olfactory oP300 extraction. When extracting olfactory mismatch negative wave oMMN, under non-attentional conditions, the deviation stimulus ERP is subtracted from the standard stimulus ERP, and the negative component of the difference wave that appears within a time window of 150-250 ms is taken as the olfactory mismatch negative wave oMMN; it reflects the brain's automatic deviation detection ability in pre-attention.

[0059] When olfactory oP300 is retrieved, under an active attention task, the biased stimulus ERP is directly observed, and the positive components appearing within a time window of 250-500 ms are taken as olfactory oP300. This reflects the process of attention allocation and working memory updating.

[0060] The method of using a research platform for olfactory cognitive neurons includes the following specific steps: S1. Issue the experiment start command through the main control computer 101; S2, Central synchronizer 102 continuously monitors the signal of respiratory sensor 103; When a valid breath is detected at the start of the inspiratory phase, the central synchronizer 102 synchronously performs the following operations. Send commands to the MFCs and solenoid valves of the olfactory stimulation module 2 to release preset odor stimuli; Send a TTL trigger flag to the amplifier of EEG acquisition module 3; S3, EEG acquisition module 3 records EEG data with TTL trigger markers; S4. After the experiment, the data collected by the EEG acquisition module 3 is transmitted to the data processing and cognitive component analysis module 4 for analysis.

[0061] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A research platform for olfactory cognitive neurons, characterized in that, include: An integrated main control and synchronization module is used to control other modules; The olfactory stimulation module is used for mixing and transporting the test gas; The EEG acquisition module is used to collect the subject's brainwave data; The data processing and cognitive component analysis module is used to preprocess and analyze the collected data.

2. The olfactory cognitive neural research platform according to claim 1, characterized in that, The integrated main control and synchronization module includes: The main control computer is used to control and monitor the overall platform. The central synchronizer is used to connect to the main control computer. The central synchronizer has a built-in delay compensation unit and is connected to the respiratory sensor, the stimulation control unit and the EEG marker unit respectively. The delay compensation unit is used to eliminate the time offset caused by odor transmission and ensure that the trigger signal is strictly aligned with the actual odor stimulus in time. A breathing sensor is used to receive airflow signals from the subject's nasal cavity; The stimulation control unit is used to send drive commands to the olfactory stimulation module through the digital I / O port; The EEG tagging unit is used to connect to the EEG acquisition module circuit. The EEG tagging unit is connected to the amplifier trigger input port circuit of the EEG acquisition module through a cable to directly send TTL synchronization signals.

3. The olfactory cognitive neural research platform according to claim 2, characterized in that, The specific working steps of the delay compensation unit are as follows: A1. When the main control computer issues a stimulus trigger command, the command time is recorded as t1; A2. Determine whether the gas concentration detected by the gas sensor in the breathing sensor has reached the 50% peak value in real time. If the determination is yes, record the arrival time as t2. A3. Calculate the fixed transmission delay time Δt = t2 - t1; A4. Store Δt. In subsequent data analysis, use Δt to perform delay correction on the time point when the main control computer issues the stimulus trigger command. A5. Terminate the process.

4. The olfactory cognitive neural research platform according to claim 2, characterized in that, The olfactory stimulation module includes: Air source, used to provide clean compressed air; There are multiple independent gas paths, each of which is connected to a gas source phase and a corresponding odorant transmission device to transmit carrier gas, standard odorant, and deviation odorant. Mass flow controllers (MFCs) are installed on each independent gas path to receive analog signals from the central synchronizer and control the instantaneous flow rate of each independent gas path, thereby achieving online dynamic dilution of concentration. High-speed solenoid valves are located downstream of each independent olfactory transmission gas path and are used to receive TTL commands from the central synchronizer to control the opening and closing of the corresponding independent gas path. The gas mixing chamber is interconnected with each independent gas path and is used to mix the gases transmitted in each gas path; The temperature and humidification unit is located in the gas mixing chamber and is used to control the temperature and humidification of the mixing chamber and its output pipeline. The activated carbon filter and vacuum pump are connected to separate gas lines. During the stimulation interval, the vacuum pump is activated to quickly draw out residual odor molecules and purify them through the activated carbon filter to ensure no odor background.

5. The olfactory cognitive neural research platform according to claim 2, characterized in that: The EEG acquisition module is connected to the central synchronizer circuit to receive synchronization marker signals from the central synchronizer. The EEG acquisition module is also connected to the data processing and cognitive component analysis module circuit to transmit the raw EEG data acquired by the EEG acquisition module to the processing module for data processing.

6. The olfactory cognitive neural research platform according to claim 5, characterized in that: The EEG acquisition module has an electrode sampling area in the forehead region of the scalp. This sampling area covers the scalp region corresponding to the Fp, AF, and F series positions in the international standard EEG electrode positioning system. The EEG acquisition module has an electrode sampling area in the anterior temporal region, which covers the bilateral anterior temporal scalp area where FT7 and FT8 are located in the international standard EEG electrode localization system. Multiple electrodes are arrayed in the electrode sampling area of ​​the forehead and anterior temporal regions of the scalp, with a spacing of less than or equal to 2 cm between each electrode.

7. The olfactory cognitive neural research platform according to claim 3, characterized in that, The specific data processing steps of the data processing and cognitive component analysis module are as follows: B1. Data preprocessing: bandpass filtering of the raw EEG data in the range of 0.1-30 Hz and removal of physiological artifacts. B2. Delay Compensation and Segmentation: The embedded markers in the EEG data are read, and the time points after time compensation for all markers are calculated. The formula for calculating the compensated time points is as follows: t_corrected = t_original - Δt In the formula, t_corrected is the time point after compensation; t_original is the marking time; Δt is the fixed transmission delay time; and the marking time is the time point when the central synchronizer sends the TTL trigger marking to the EEG acquisition module. B3. Based on the compensated time point, extract the EEG segments from 200ms before stimulation to 800ms after stimulation from the EEG data. B4. Baseline correction is performed on each EEG segment extracted in B3. The mean EEG signal 200 ms before stimulation is used as the baseline. The mean baseline is subtracted from the signal amplitude at each time point in the segment to eliminate the influence of baseline drift on the EEG signal. After baseline correction is completed, the EEG segments are grouped according to the stimulation type. All single-test EEG segments corresponding to the same stimulation type are superimposed and averaged.

8. The olfactory cognitive neural research platform according to claim 3, characterized in that, The cognitive analysis extraction algorithms in the data processing and cognitive component analysis module include: olfactory mismatch negative wave oMMN extraction and olfactory oP300 extraction. When extracting the olfactory mismatch negative wave oMMN, under non-attentional conditions, the deviation stimulus ERP is subtracted from the standard stimulus ERP, and the negative component of the difference wave that appears within a time window of 150-250 ms is taken as the olfactory mismatch negative wave oMMN. When olfactory oP300 is extracted, under active attention task, the biased stimulus ERP is directly observed, and the positive components appearing within the 250-500ms time window are taken as olfactory oP300.

9. A method of using an olfactory cognitive neural research platform, for using an olfactory cognitive neural research platform as described in any one of claims 1-7, characterized in that... The specific steps include: S1. Issue the experiment start command through the main control computer; S2, The central synchronizer continuously monitors the signals from the respiratory sensor; When a valid breath is detected at the start of the inspiratory phase, the central synchronizer performs the following operations synchronously. Send commands to the MFCs and solenoid valves of the olfactory stimulation module to release preset odor stimuli; Send a TTL trigger flag to the amplifier in the EEG acquisition module; S3, the EEG acquisition module records EEG data with TTL trigger markers; S4. After the experiment, the data collected by the EEG acquisition module is transmitted to the data processing and cognitive component analysis module for analysis.

Images