A bioelectric signal acquisition sensor conditioning and data conversion method and system

Abstract

The application is suitable for the field of bioelectric signal acquisition and sensor signal conditioning technology, and provides a bioelectric signal acquisition sensor conditioning and data conversion method and system. The method comprises the following steps: after a preset acquisition period is completed in a current weak bioelectric signal data output situation, the current local coupling attenuation intensity is calculated, and when the current local coupling attenuation intensity exceeds a local coupling attenuation reference value, a gain correction factor is generated according to the difference between the two, so as to correct the initial gain parameter range, and subsequent weak signal conditioning and analog-to-digital conversion are completed based on the corrected gain parameter range. By determining the local coupling attenuation reference value corresponding to the turning point of the effective conversion quality margin, and correcting the initial gain parameter range when the current local coupling attenuation intensity exceeds the reference value, the weak bioelectric signal compressed locally can be moderately compensated.

Description

Technical Field

[0001] This invention belongs to the field of bioelectric signal acquisition and sensor signal conditioning technology, and particularly relates to a method and system for bioelectric signal acquisition sensor conditioning and data conversion. Background Technology

[0002] With the development of flexible electronics and wearable data acquisition devices, adhesive flexible sensors are increasingly being used in scenarios involving the acquisition of weak bioelectrical signals. These sensors typically form an adhesive contact interface using an adhesive layer, flexible substrate, conductive contact layer, or flexible clamping structure to couple the weak bioelectrical signal at the interface to the sensor input. Because weak bioelectrical signals have low amplitudes and are susceptible to DC bias, low-frequency drift, transient impacts, and changes in contact state, they usually require a front-end conditioning module and an analog-to-digital converter to perform amplification, filtering, gain control, and data conversion.

[0003] In existing technologies, a common approach is to use existing gain control strategies to configure the initial gain parameter range for the current weak bioelectrical signal data output. This initial gain parameter range is generally determined based on the weak signal amplitude range, DC bias, low-frequency drift, transient impact, saturation risk, or ADC range utilization, and can ensure that weak signal conditioning and analog-to-digital conversion meet basic requirements in most cases. However, in the actual acquisition process of attached flexible sensors, factors such as micro-gap in the adhesive layer, micro-slippage at the interface, local warping, local debonding, uneven adhesive layer thickness, local rebound of the flexible substrate, and micro-fluctuations in flexible clamping pressure can easily cause micro-perturbations in local contact coupling.

[0004] For the aforementioned local contact coupling perturbations, existing technologies mostly treat them as ordinary noise, low-amplitude fluctuations, or anomalous segments, filtering, weakening, or eliminating them, with little further analysis of their impact on the effective conversion quality margin. In reality, such perturbations can cause a slight decrease in the coupling transmission efficiency of the weak bioelectrical signal at the contact interface to the sensor input within one or more local sampling segments. This results in a decrease in quality margins such as ADC range utilization, effective signal-to-noise ratio, or effective resolution, even though the initial gain parameter range can maintain basic acquisition and analog-to-digital conversion. Therefore, it is necessary to provide a bioelectrical signal acquisition sensor conditioning and data conversion method that can correct the initial gain parameter range for local coupling attenuation. Summary of the Invention

[0005] The purpose of this invention is to provide a method and system for conditioning and converting data from a bioelectric signal acquisition sensor, in order to solve the problems mentioned in the background art.

[0006] This invention is implemented as follows: a method for conditioning and data conversion of a bioelectrical signal acquisition sensor, the method comprising:

[0007] S1. Obtain the weak bioelectric signal data output by the current attached flexible sensor in the micro-vibration acquisition scenario of the structural component, and call the initial gain parameter range configured by the existing gain control strategy.

[0008] S2. Obtain reference samples from the historical sample library that match the background conditions of the current weak bioelectric signal data output, and determine the local coupling attenuation intensity and the corresponding effective conversion quality margin of each reference sample within the preset acquisition period; wherein, the local coupling attenuation intensity is a parameter characterizing the degree to which the coupling transmission efficiency of the weak bioelectric signal at the attached contact interface to the sensor input end is slightly reduced due to local contact coupling perturbation in one or more local sampling segments.

[0009] S3. Based on the relationship between the local coupling attenuation intensity and the effective conversion quality margin of each reference sample, determine the local coupling attenuation reference value that causes the effective conversion quality margin to decrease in a turning point.

[0010] S4. After completing the preset acquisition cycle under the current weak bioelectric signal data output condition, calculate the current local coupling attenuation intensity. When the current local coupling attenuation intensity exceeds the local coupling attenuation reference value, generate a gain correction factor based on the difference between the two to correct the initial gain parameter range. Then, complete the subsequent weak signal conditioning and analog-to-digital conversion based on the corrected gain parameter range.

[0011] As a further limitation of the technical solution of the present invention, the background conditions that match the current weak bioelectric signal data output situation mean that the reference sample and the current weak bioelectric signal data output situation are consistent at least in terms of sensor type, attachment or clamping method and initial gain parameter range, and are consistent in at least one of the following: material of the measured structure, acquisition conditions, sampling frequency, weak signal amplitude range and characteristic range of DC bias, low frequency drift and transient impact.

[0012] As a further limitation of the technical solution of the present invention, the preset acquisition period is the pre-acquisition stage after the current weak bioelectric signal data output is started; the pre-acquisition stage continuously acquires no less than N sampling points according to the preset sampling frequency, and the weak bioelectric signal data corresponding to the N sampling points contains at least one complete signal waveform segment, which is determined by the sampling data between two adjacent zero-crossing points in the same direction, the sampling data between two adjacent peaks, or the sampling data between two adjacent troughs.

[0013] As a further limitation of the technical solution of the present invention, the local contact coupling micro-perturbation includes at least one of the following: adhesive layer micro-gap, interface micro-slippage, local warping, local debonding, uneven adhesive layer thickness, local rebound of flexible substrate, and micro-fluctuation of flexible clamping pressure.

[0014] As a further limitation of the technical solution of this invention, the calculation process of the local coupling attenuation intensity includes: dividing multiple local sampling segments within a preset acquisition period; determining the amplitude attenuation ratio, energy loss ratio, duration ratio, and waveform correlation reduction ratio of each local sampling segment relative to a reference sampling segment; wherein, the reference sampling segment is a sampling segment in the same preset acquisition period that has not experienced local contact coupling perturbation; and performing weighted fusion based on the amplitude attenuation ratio, energy loss ratio, duration ratio, and waveform correlation reduction ratio to obtain the local coupling attenuation intensity.

[0015] As a further limitation of the technical solution of the present invention, the effective conversion quality margin is the difference or normalized difference between the actual conversion quality index corresponding to the reference sample and the preset qualified quality threshold; wherein, the actual conversion quality index is determined based on at least two of the following: ADC range utilization, effective signal-to-noise ratio, effective resolution, saturated sampling point ratio and waveform integrity.

[0016] As a further limitation of the technical solution of this embodiment of the invention, the process of determining the local coupling attenuation reference value includes: sorting several reference samples in order of increasing local coupling attenuation intensity to obtain a sample sequence; extracting the effective conversion quality margin change trend corresponding to each reference sample in the sample sequence; when the change trend shows a state of first stabilization, then a turning point and decrease, and then tending to stabilize after decreasing to a low range, the local coupling attenuation intensity corresponding to the position where the first turning point and decrease occurs is determined as the local coupling attenuation reference value; when the change trend does not meet the above state, the gain parameter range correction is stopped, and the initial gain parameter range is used.

[0017] As a further limitation of the technical solution of the present invention, the process of improving the initial gain parameter range includes: after completing a preset acquisition cycle in the current weak bioelectric signal data output situation, determining the current local coupling attenuation intensity within the preset acquisition cycle; determining whether the current local coupling attenuation intensity exceeds the local coupling attenuation reference value; if it exceeds, generating a gain correction factor based on the degree to which the current local coupling attenuation intensity exceeds the local coupling attenuation reference value, and using the gain correction factor to improve the gain parameter in the initial gain parameter range.

[0018] As a further limitation of the technical solution of this embodiment of the invention, in step S4, a preset correction function is used to correct the initial gain parameter range; wherein, for any gain value to be corrected in the initial gain parameter range... Corrected gain value satisfy:

[0019] ;

[0020] in, The current local coupling attenuation strength, The reference value for local coupling attenuation is greater than zero. This is the gain correction factor. To determine the slope of the decreasing trend of the effective conversion mass margin as a function of the local coupling attenuation intensity after the local coupling attenuation intensity exceeds the local coupling attenuation reference value, and These are the lower limit and upper limit of the safety gain, respectively. Used to limit the corrected gain value within a safe gain range; the corrected gain value corresponding to each gain value to be corrected in the initial gain parameter range constitutes the corrected gain parameter range.

[0021] A bioelectric signal acquisition sensor conditioning and data conversion system, the system comprising: a data acquisition module, used to acquire weak bioelectric signal data output by the current attached flexible sensor in the micro-vibration acquisition scenario of the structural component, and to call the initial gain parameter range configured by the existing gain control strategy;

[0022] The reference sample matching module is used to obtain reference samples from the historical sample library that match the background conditions of the current weak bioelectric signal data output, and to determine the local coupling attenuation intensity and the corresponding effective conversion quality margin of each reference sample within the preset acquisition period.

[0023] Local coupling attenuation intensity is a parameter characterizing the degree to which the coupling transmission efficiency of the weak bioelectrical signal at the contact interface to the sensor input is slightly reduced in one or more local sampling segments due to local contact coupling perturbation.

[0024] The reference value determination module is used to determine the local coupling attenuation reference value that causes the effective conversion quality margin to decrease in a turning point, based on the relationship between the local coupling attenuation intensity and the effective conversion quality margin of each reference sample.

[0025] The gain correction and conversion module is used to calculate the current local coupling attenuation intensity after completing a preset acquisition cycle under the current weak bioelectric signal data output condition. When the current local coupling attenuation intensity exceeds the local coupling attenuation reference value, a gain correction factor is generated based on the difference between the two to correct the initial gain parameter range. The subsequent weak signal conditioning and analog-to-digital conversion are then completed based on the corrected gain parameter range.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] To address the issue that when using attached flexible sensors to acquire weak bioelectrical signals, local contact coupling perturbations are easily treated as ordinary noise by existing technologies, resulting in a decrease in effective conversion quality margin even though the initial gain parameter range can meet the basic acquisition and analog-to-digital conversion requirements. Therefore, a secondary gain correction mechanism based on the relationship between the local coupling attenuation intensity and the historical variation of the effective conversion quality margin is proposed.

[0028] By determining the local coupling attenuation reference value corresponding to the turning point decrease in effective conversion quality margin, and correcting the initial gain parameter range when the current local coupling attenuation intensity exceeds the reference value, it is possible to moderately compensate for locally compressed weak bioelectric signals, improve ADC range utilization and effective signal-to-noise ratio, reduce data quality margin loss caused by slight changes in the attachment contact state, and thus improve the stability and adaptability of subsequent weak signal conditioning and analog-to-digital conversion. Attached Figure Description

[0029] Figure 1 A flowchart of the method provided in the embodiments of the present invention; Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0031] Figure 1 A flowchart of the method provided by an embodiment of the present invention is shown.

[0032] Specifically, a method for conditioning and converting data from a bioelectrical signal acquisition sensor includes the following steps:

[0033] Step S1: Obtain the weak bioelectrical signal data output by the current attached flexible sensor in the micro-vibration acquisition scenario of the structural component, and call the initial gain parameter range configured by the existing gain control strategy. The structural component is the attached support structure, flexible substrate structure, or clamping support structure in the attached flexible sensor, rather than the industrial structural component that is the object of detection.

[0034] Step S2: Obtain reference samples from the historical sample library that match the background conditions of the current weak bioelectric signal data output, and determine the local coupling attenuation intensity and corresponding effective conversion quality margin of each reference sample within a preset acquisition period. The local coupling attenuation intensity is a parameter characterizing the degree to which the coupling transmission efficiency of the weak bioelectric signal at the adhesive interface slightly decreases within one or more local sampling segments due to local contact coupling perturbations. These local contact coupling perturbations include at least one of the following: adhesive layer micro-gap, interface micro-slippage, local warping, local debonding, uneven adhesive layer thickness, local rebound of the flexible substrate, and micro-fluctuations in flexible clamping pressure.

[0035] The background conditions that match the current weak bioelectric signal data output situation mean that the reference sample and the current weak bioelectric signal data output situation are consistent at least in terms of sensor type, attachment or clamping method and initial gain parameter range, and are consistent in at least one of the following: material of the structure under test, acquisition conditions, sampling frequency, weak signal amplitude range and characteristic range of DC bias, low frequency drift and transient impact.

[0036] The preset acquisition period is the pre-acquisition stage after the current weak bioelectric signal data output is started; the pre-acquisition stage continuously acquires no less than N sampling points according to the preset sampling frequency, and the weak bioelectric signal data corresponding to the N sampling points contains at least one complete signal waveform segment. The complete signal waveform segment is determined by the sampling data between two adjacent zero-crossing points in the same direction, the sampling data between two adjacent peaks, or the sampling data between two adjacent troughs.

[0037] In this embodiment of the invention, the main focus is on improving the gain parameter adaptation problem of bioelectric signal acquisition sensors during actual acquisition, conditioning, transmission, and analog-to-digital conversion. Bioelectric signals are typically weak signals with low amplitude, easily affected by contact conditions and environmental interference. When acquiring these signals using an adhesive flexible sensor, the sensor needs to form an adhesive contact interface with the area to be acquired through an adhesive layer, flexible substrate, conductive contact layer, or flexible clamping structure, and couple the weak bioelectric signal to the sensor input terminal through this interface. The adhesive flexible sensor can be a flexible electrode sheet, a flexible piezoresistive / piezoelectric composite acquisition sheet, a flexible conductive film sensor, or a wearable acquisition patch with a flexible substrate. It can adapt to slight deformations or vibrations at the attachment position to improve wearing or installation stability.

[0038] In existing technologies, pre-defined gain control strategies are typically configured for weak bioelectrical signal data output by attached flexible sensors. These strategies can configure an initial gain parameter range for the current weak bioelectrical signal data output by invoking preset rules, lookup table strategies, or automatic gain control algorithms, based on parameters such as the amplitude range, DC bias, low-frequency drift, transient impact, saturation risk, and ADC range utilization. This initial gain parameter range may include parameters such as a lower gain limit, an upper gain limit, selectable gain levels, gain step size, or gain switching threshold. Generally, this initial gain parameter range allows for reasonable subsequent weak signal conditioning and analog-to-digital conversion, ensuring the conversion results meet basic acquisition and transmission requirements.

[0039] However, after analyzing a large number of historical samples, this invention found that for cases where attached flexible sensors output weak bioelectrical signal data under micro-vibration acquisition scenarios of structural components, although the initial gain parameter range configured by existing gain control strategies can usually ensure that data acquisition, transmission, and analog-to-digital conversion meet the requirements, it does not necessarily guarantee that the effective conversion quality margin remains at a high level. Specifically, in this type of attached contact scenario, factors such as micro-gap in the adhesive layer, micro-slippage at the interface, local warping, local debonding, uneven adhesive layer thickness, local rebound of the flexible substrate, and micro-fluctuations in flexible clamping pressure may cause local contact coupling perturbations. These local contact coupling perturbations do not persist throughout the entire acquisition process but may occur sporadically in one or more local sampling segments, manifesting as a slight decrease in the coupling transmission efficiency of the weak bioelectrical signal at the attached contact interface to the sensor input.

[0040] The aforementioned local contact coupling perturbations are somewhat objective and unavoidable. This is because the attached flexible sensor does not connect to the object through a completely rigid connection, but rather relies on an adhesive layer, flexible substrate, conductive contact layer, or flexible clamping structure to form the attachment contact interface. During actual data acquisition, factors such as attachment pressure, adhesive layer thickness, local surface flatness, the rebound state of the flexible material, minute displacements, and local micro-vibrations of the object can all alter the local contact state, causing slight attenuation of the weak bioelectrical signal within the local sampling segment. This attenuation typically does not lead to complete acquisition failure, nor does it necessarily form a significant spike or saturation. Therefore, in existing technologies, it is easily categorized as ordinary noise, low-amplitude fluctuations, or abnormal segments, and is filtered out, weakened, or directly eliminated in subsequent data transmission or conversion processing.

[0041] Further investigation revealed that, among multiple reference samples under similar background conditions, the triggering degree of local contact coupling perturbations varied, resulting in differences in the local coupling attenuation intensity for each reference sample. Correlation analysis between local coupling attenuation intensity and effective conversion quality margin showed that, as local coupling attenuation intensity increases, the effective conversion quality margin does not immediately decrease. Instead, it typically exhibits a pattern of initial relative stability followed by a sharp decline at a certain point. In other words, when the local coupling attenuation intensity is in a low range, the initial gain parameter range configured by the existing gain control strategy can still maintain a good quality margin; however, when the local coupling attenuation intensity continues to increase and crosses the turning point in this relationship, even if subsequent weak signal conditioning and analog-to-digital conversion still meet the requirements, the effective conversion quality margin will significantly decrease.

[0042] Based on this discovery, this invention does not negate the rationality of existing gain control strategies. Instead, it introduces a historical relationship between local coupling attenuation strength and effective conversion quality margin, building upon the initial gain parameter range. Since local contact coupling perturbations primarily reduce the coupling transmission efficiency of weak bioelectrical signals to the sensor input, causing local compression of the effective signal amplitude, when subsequent outputs of the weak bioelectrical signal exhibit a similar attenuation trend, a secondary gain correction can be performed on the initial gain parameter range based on this attenuation trend. This allows the compressed effective signal to occupy a more reasonable ADC input range in subsequent analog-to-digital conversion, thereby suppressing further decline in the effective conversion quality margin.

[0043] In step S1, "current" refers to the current actual situation of weak bioelectrical signal data output. This can be a new acquisition task or any subsequent acquisition stage within the same task. After the currently attached flexible sensor outputs weak bioelectrical signal data in the micro-vibration acquisition scenario of the structural component, the system does not directly change the existing gain control strategy. Instead, it calls the initial gain parameter range already configured in the existing gain control strategy. The purpose of this setting is to enable the present invention to be compatible with existing automatic gain control, preset gain level control, or lookup table-based gain control mechanisms, and to focus the improvement on the subsequent correction of the initial gain parameter range, thereby avoiding repeated calculations or replacement of existing mature gain strategies.

[0044] In step S2, a reference sample matching the background conditions of the current weak bioelectrical signal data output is obtained from the historical sample library. This aims to ensure that the subsequently determined local coupling attenuation reference value reflects the patterns of the current actual scenario, rather than originating from a significantly different acquisition environment. If the reference sample differs too much from the current weak bioelectrical signal data output, for example, in sensor type, attachment or clamping method, initial gain parameter range, sampling frequency, or weak signal amplitude range, the relationship between local coupling attenuation strength and effective conversion quality margin may no longer be applicable to the current situation, leading to distortion of the local coupling attenuation reference value. Therefore, this invention requires that the reference sample be consistent with the current weak bioelectrical signal data output at least in sensor type, attachment or clamping method, and initial gain parameter range, and also consistent in all aspects of the measured structure material, acquisition conditions, sampling frequency, weak signal amplitude range, and the characteristic ranges of DC bias, low-frequency drift, and transient impact.

[0045] In some implementations, in addition to the matching conditions mentioned above, further auxiliary screening can be performed by considering factors such as attachment location, adhesive material type, adhesive thickness grade, flexible substrate material, sensor usage time, ambient temperature, ambient humidity, motion state of the target object, power supply status, ADC reference voltage, filtering parameters, or data transmission method. The system can set preset similarity values ​​for different background conditions. These preset similarity values ​​are calculated by assigning weights to the influence of each background condition on the local coupling attenuation strength and effective conversion quality margin. Since historical samples in actual acquisition scenarios cannot be completely identical to the current weak bioelectrical signal data output, this invention does not require all background conditions to be exactly the same. Instead, it allows for the determination of usable reference samples based on preset similarity values, provided that the core conditions are consistent, thus balancing sample representativeness and sample quantity.

[0046] During sample screening, a progressively looser screening approach can be adopted. Specifically, the system can first screen reference samples according to a higher preset similarity threshold; when the number of selected reference samples is insufficient to support subsequent change relationship analysis, the preset similarity threshold can be gradually lowered or some non-core background conditions can be relaxed; when the preset similarity threshold is lowered to a preset lower limit and still cannot obtain enough reference samples, the current gain parameter range correction is stopped, and the initial gain parameter range is retained. Since the historical sample database contains a large number of samples, and these samples involve multi-dimensional background conditions and various waveform features, in some implementations, machine learning models, clustering models, similarity retrieval models, or other artificial intelligence-assisted methods can be used to quickly match and sort historical samples to improve the efficiency of reference sample screening.

[0047] In step S2, the preset acquisition period is used to acquire basic data representing the current attachment contact state in the pre-process stage of the current weak bioelectrical signal data output. The preset acquisition period is not a data segment of arbitrary length, but rather a pre-process acquisition stage after the current weak bioelectrical signal data output is initiated. This pre-process acquisition stage continuously acquires no fewer than N sampling points at a preset sampling frequency, and the weak bioelectrical signal data corresponding to the N sampling points contains at least one complete signal waveform segment. The complete signal waveform segment can be determined by the sampling data between two adjacent zero-crossing points in the same direction, the sampling data between two adjacent peaks, or the sampling data between two adjacent troughs.

[0048] The significance of setting a preset acquisition period is to enable the system to identify the presence of local contact coupling perturbations at the current attachment interface and calculate the current local coupling attenuation strength before formally applying the corrected gain parameter range for subsequent weak signal conditioning and analog-to-digital conversion. If the preset acquisition period is too short, it may not cover a complete signal waveform segment, resulting in a lack of comparability between local sampling segments; if the preset acquisition period is too long, it may reduce the response speed of gain correction. Therefore, by limiting the preset acquisition period through the preset sampling frequency, the preset number of sampling points N, and the complete signal waveform segment, the reliability of the current local coupling attenuation strength calculation can be ensured while minimizing the impact on the real-time performance of subsequent weak signal conditioning and analog-to-digital conversion.

[0049] Furthermore, the bioelectric signal acquisition sensor conditioning and data conversion method also includes:

[0050] The calculation process of the local coupling attenuation intensity includes: dividing the sample into multiple local sampling segments within a preset acquisition period; determining the amplitude attenuation ratio, energy loss ratio, duration ratio, and waveform correlation reduction ratio of each local sampling segment relative to the reference sampling segment; wherein, the reference sampling segment is a sampling segment within the same preset acquisition period that has not experienced local contact coupling perturbation; and performing weighted fusion based on the amplitude attenuation ratio, energy loss ratio, duration ratio, and waveform correlation reduction ratio to obtain the local coupling attenuation intensity.

[0051] The effective conversion quality margin is the difference or normalized difference between the actual conversion quality index corresponding to the reference sample and the preset qualified quality threshold; wherein, the actual conversion quality index is determined based on at least two of the following: ADC range utilization, effective signal-to-noise ratio, effective resolution, saturation sampling point ratio, and waveform integrity.

[0052] In this embodiment of the invention, the local coupling attenuation intensity is used to quantify the impact of local contact coupling perturbations on the coupling transmission efficiency of weak bioelectric signals. Its calculation does not directly classify local abnormal segments as ordinary noise, but rather uses a benchmark sampling segment comparison method for judgment. Specifically, within a preset acquisition period, the continuously acquired weak bioelectric signal data is divided into multiple local sampling segments, and sampling segments within the same preset acquisition period that have not experienced local contact coupling perturbations are selected as benchmark sampling segments; the benchmark sampling segment can be a sampling segment whose amplitude, energy, and waveform morphology are all in a relatively stable state.

[0053] For any local sampling segment, calculate its amplitude attenuation ratio, energy loss ratio, duration ratio, and waveform correlation decrease ratio relative to the reference sampling segment. The amplitude attenuation ratio characterizes the degree to which the effective amplitude of the local sampling segment decreases compared to the reference sampling segment; the energy loss ratio characterizes the degree to which the signal energy of the local sampling segment decreases compared to the reference sampling segment; the duration ratio characterizes the proportion of time the local sampling segment persists within the preset acquisition period; and the waveform correlation decrease ratio characterizes the degree of deviation in waveform shape between the local sampling segment and the reference sampling segment.

[0054] The above comparison distinguishes local coupling attenuation from ordinary noise. Ordinary noise typically manifests as random disturbances, spikes, or high-frequency fluctuations, while local coupling attenuation usually manifests as a synchronous decrease in effective amplitude and signal energy at the same or similar waveform positions, with a certain duration. Therefore, by comparing reference sampling segments, it can be shown that this change mainly originates from local contact state changes at the attached interface, rather than simply random noise.

[0055] After obtaining the amplitude attenuation ratio, energy loss ratio, duration ratio, and waveform correlation decrease ratio for each local sampling segment, a weighted fusion can be performed according to preset weights to obtain the local coupling attenuation strength. The preset weights can be set empirically or determined based on the correlation between each indicator and the effective conversion quality margin in historical samples. For example, in scenarios with low amplitude weak bioelectric signals, the weights of the amplitude attenuation ratio and energy loss ratio can be increased; in scenarios with high waveform integrity requirements, the weight of the waveform correlation decrease ratio can be increased.

[0056] Effective conversion quality margin is used to characterize the quality allowance that a reference sample retains after meeting basic conversion requirements. It can be calculated as the difference between the actual conversion quality index of the reference sample and a preset acceptable quality threshold, or as the normalized difference between the two. This calculation method is a relatively mature data quality evaluation method, aiming to distinguish between reference samples that are "just acceptable" and those with "high quality margins."

[0057] In some implementations, the actual conversion quality metrics can be determined based on at least two of the following: ADC range utilization, effective signal-to-noise ratio (SNR), effective resolution, saturation sampling point ratio, and waveform integrity. This invention prioritizes ADC range utilization and effective SNR. This is because secondary gain correction primarily affects the input range occupied by weak bioelectrical signals entering the ADC analog-to-digital conversion module, and also affects the relative distinguishability between the effective signal and noise. Therefore, ADC range utilization reflects whether the weak bioelectrical signal is adequately mapped to the ADC input range, and effective SNR reflects whether the conditioned and converted effective signal still has good identifiability.

[0058] In addition to the methods described above, the effective conversion quality margin can also be determined based on the difference between the effective resolution and the minimum resolution requirement, the difference between the waveform integrity and the minimum integrity requirement, the inverse difference between the saturated sampling point ratio and the allowable saturation ratio, or the difference between the comprehensive quality score obtained by weighting multiple quality indicators and the preset qualified quality threshold. In cases with multiple quality indicators, the minimum value among the individual quality margins can be taken as the effective conversion quality margin to ensure that the obtained effective conversion quality margin reflects the weakest conversion quality link in the reference sample.

[0059] Furthermore, the bioelectric signal acquisition sensor conditioning and data conversion method also includes the following steps:

[0060] Step S3: Based on the relationship between the local coupling attenuation intensity and the effective conversion mass margin of each reference sample, determine the local coupling attenuation reference value that causes the effective conversion mass margin to decrease in a turning point.

[0061] The process of determining the local coupling attenuation reference value includes: sorting several reference samples in ascending order of local coupling attenuation intensity to obtain a sample sequence; extracting the effective conversion quality margin change trend corresponding to each reference sample in the sample sequence; when the change trend shows a state of first stabilization, then a turning point and decline, and then tending to stabilize after declining to a low range, the local coupling attenuation intensity corresponding to the first turning point and decline is determined as the local coupling attenuation reference value; when the change trend does not meet the above state, the gain parameter range correction is stopped, and the initial gain parameter range is used.

[0062] In this embodiment of the invention, step S3 is used to identify whether there is a relationship between the local coupling attenuation intensity and the effective conversion quality margin within the reference sample range that can be used for gain parameter range correction. Specifically, after completing the reference sample screening, the reference samples are arranged in ascending order of local coupling attenuation intensity to obtain a sample sequence, and the effective conversion quality margin corresponding to each reference sample in the sample sequence is extracted to form the trend of the effective conversion quality margin changing with the local coupling attenuation intensity.

[0063] It should be noted that not all current weak bioelectrical signal data output scenarios necessarily exhibit the aforementioned trend. In some acquisition scenarios, local contact coupling perturbations may be weak, or the distribution of local coupling attenuation intensity in the reference sample may not be obvious. In such cases, the effective conversion quality margin may not exhibit a state of initial stabilization, followed by a sharp decline and then stabilization after reaching a low level. For such cases, it indicates that the local coupling attenuation intensity and the effective conversion quality margin are insufficient to form a stable correction basis. Therefore, gain parameter range correction is stopped, and the initial gain parameter range configured by the existing gain control strategy is used to avoid erroneous corrections based on unreliable changing relationships.

[0064] In some implementations, the identification of the trend can be achieved through a rate of change determination method. Specifically, the rate of change of the effective conversion mass margin corresponding to adjacent reference samples is calculated sequentially along the sample sequence; when the rate of change of the effective conversion mass margin corresponding to consecutive adjacent reference samples is less than a first rate of change threshold, the corresponding segment is determined to be in a stable state; when, starting from a certain reference sample, the rate of decrease of the effective conversion mass margin is continuously greater than a second rate of change threshold, it is determined that a turning point in the decline has begun from the corresponding position of that reference sample, and the local coupling attenuation intensity corresponding to that position is determined as the local coupling attenuation reference value. The first rate of change threshold is used to determine whether the effective conversion mass margin remains basically stable, and the second rate of change threshold is used to determine whether the effective conversion mass margin has shown a continuous decline.

[0065] The significance of determining the local coupling attenuation reference value lies in providing a triggering basis for whether to subsequently make a secondary correction to the initial gain parameter range. In other words, the local coupling attenuation reference value is not an arbitrarily set empirical threshold, but rather a turning point determined based on the historical relationship between the local coupling attenuation intensity and the effective conversion quality margin in the reference sample. This local coupling attenuation reference value can distinguish between the situation where "local contact coupling perturbations exist but have not yet significantly affected the effective conversion quality margin" and the situation where "local contact coupling perturbations have caused the effective conversion quality margin to begin a downward trend."

[0066] Therefore, in the subsequent output of weak bioelectrical signal data, if the current local coupling attenuation intensity does not exceed the local coupling attenuation reference value, it indicates that the initial gain parameter range still has good applicability and can continue to be used; if the current local coupling attenuation intensity exceeds the local coupling attenuation reference value, it indicates that the local coupling attenuation at the current attachment contact interface has reached a level that may reduce the effective conversion quality margin. At this time, a gain correction factor is generated based on the difference between the two to correct the initial gain parameter range, so that subsequent weak signal conditioning and analog-to-digital conversion can obtain a more stable effective conversion quality margin.

[0067] Furthermore, the bioelectric signal acquisition sensor conditioning and data conversion method also includes the following steps:

[0068] Step S4: After completing the preset acquisition cycle under the current weak bioelectric signal data output condition, calculate the current local coupling attenuation intensity. When the current local coupling attenuation intensity exceeds the local coupling attenuation reference value, generate a gain correction factor based on the difference between the two to correct the initial gain parameter range. Then, complete the subsequent weak signal conditioning and analog-to-digital conversion based on the corrected gain parameter range.

[0069] The process of improving the initial gain parameter range includes: after completing a preset acquisition cycle under the current weak bioelectric signal data output condition, determining the current local coupling attenuation intensity within the preset acquisition cycle; determining whether the current local coupling attenuation intensity exceeds the local coupling attenuation reference value; if it exceeds, generating a gain correction factor based on the degree to which the current local coupling attenuation intensity exceeds the local coupling attenuation reference value, and using the gain correction factor to improve the gain parameter in the initial gain parameter range.

[0070] In step S4, a preset correction function is used to correct the initial gain parameter range; wherein, for any gain value to be corrected within the initial gain parameter range... Corrected gain value satisfy:

[0071] ;

[0072] in, The current local coupling attenuation strength, The reference value for local coupling attenuation is greater than zero. This is the gain correction factor. To determine the slope of the decreasing trend of the effective conversion mass margin as a function of the local coupling attenuation intensity after the local coupling attenuation intensity exceeds the local coupling attenuation reference value, and These are the lower limit and upper limit of the safety gain, respectively. Used to limit the corrected gain value within a safe gain range; the corrected gain value corresponding to each gain value to be corrected in the initial gain parameter range constitutes the corrected gain parameter range.

[0073] In this embodiment of the invention, step S4 is used to determine whether the initial gain parameter range needs to be corrected for the current weak bioelectric signal data output situation after it has been determined that there is indeed a downward trend between the local coupling attenuation intensity and the effective conversion quality margin, and the local coupling attenuation reference value has been obtained. Specifically, the system first calculates the current local coupling attenuation intensity after completing a preset acquisition cycle for the current weak bioelectric signal data output situation; if the current local coupling attenuation intensity does not exceed the local coupling attenuation reference value, it indicates that the current local contact coupling perturbation has not yet reached the level of significantly reducing the effective conversion quality margin, and the initial gain parameter range can be used in this case; if the current local coupling attenuation intensity exceeds the local coupling attenuation reference value, it indicates that the current weak bioelectric signal data output situation has entered a local coupling attenuation state that needs compensation, and a gain correction factor is generated based on the difference between the two to perform an incremental correction on the initial gain parameter range.

[0074] The gain correction factor is generated based on the degree to which the current local coupling attenuation strength exceeds the local coupling attenuation reference value. This is significant because it avoids using a fixed-amplitude, uniform correction. In different scenarios of weak bioelectrical signal data output, the degree of decrease in coupling transmission efficiency caused by local contact coupling perturbations varies. If only a fixed gain boost is used, it may lead to over-amplification when the exceedance is slight, or insufficient compensation when the exceedance is significant. Therefore, this invention determines the correction amplitude based on the degree of exceedance, ensuring that the gain boost matches the current local coupling attenuation strength, thereby improving the adaptability of the corrected gain parameter range.

[0075] The preset correction function provided by this invention employs a two-stage processing approach: when the current local coupling attenuation strength is less than or equal to the local coupling attenuation reference value, the corrected gain value is equal to the initial gain value; when the current local coupling attenuation strength is greater than the local coupling attenuation reference value, the corrected gain value is obtained based on the initial gain value, combined with the excess ratio of the current local coupling attenuation strength relative to the local coupling attenuation reference value, the downward slope of the effective conversion quality margin, and the gain correction coefficient. The corrected gain value is then limited by a lower and upper safety gain limit. This method is intuitive and effective because it triggers correction only when the local coupling attenuation reference value is exceeded, and the correction magnitude is constrained by both the historical downward trend and the safety gain range.

[0076] The gain correction coefficient can be set based on the experimental calibration results of historical samples, sensor type, gain level of the front-end conditioning module, ADC input range, and allowable saturation risk. For example, a smaller gain correction coefficient can be set for acquisition scenarios with small fluctuations in local contact state and high saturation risk; a larger gain correction coefficient can be set for acquisition scenarios with significant local coupling attenuation and low amplitude of weak bioelectric signals. In addition to using the above-mentioned preset correction function, the initial gain parameter range can also be corrected by using a lookup table method, a piecewise linear method, an exponential increment method, a curve fitting method based on historical samples, or a gain correction factor output based on a machine learning model.

[0077] For example, in a scenario where weak bioelectrical signal data is output, the initial gain parameter range of the existing gain control strategy is 8 to 16 times. The system selects multiple reference samples from the historical sample library and determines that the effective conversion quality margin begins to decline after the local coupling attenuation intensity reaches 0.24. Therefore, 0.24 is determined as the reference value for local coupling attenuation. After completing the preset acquisition cycle in the current weak bioelectrical signal data output scenario, the current local coupling attenuation intensity is calculated to be 0.30, indicating that it has exceeded the reference value for local coupling attenuation.

[0078] At this point, the current local coupling attenuation intensity exceeds the reference value by a ratio of 0.30 minus 0.24, then divided by 0.24, which equals 0.25. If the gain correction factor is 0.40 and the absolute value of the downward slope of the effective conversion quality margin is 0.50, then the gain increase ratio can be obtained by multiplying 0.40 by 1.50 and then by 0.25, which equals 0.15. Therefore, the 8x gain value in the initial gain parameter range can be corrected to 9.2x, and the 16x gain value can be corrected to 18.4x. If the safe gain range is 4x to 20x, then both 9.2x and 18.4x are within the safe gain range; therefore, the corrected gain parameter range is 9.2x to 18.4x. Subsequent weak signal conditioning and analog-to-digital conversion are based on this corrected gain parameter range, allowing weak bioelectric signals with amplitude compression caused by local coupling attenuation to occupy a more reasonable ADC input range.

[0079] If, in another scenario with weak bioelectrical signal data output, the calculated local coupling attenuation strength is 0.20, and since it does not exceed 0.24, no boost correction is generated, and the corrected gain parameter range remains 8 to 16 times. In this way, the present invention avoids unnecessary gain boosting when the local coupling attenuation strength is low, and also enables targeted compensation when the local coupling attenuation strength exceeds the local coupling attenuation reference value.

[0080] Therefore, this invention addresses the problem of effective signal amplitude compression caused by local contact coupling perturbations in attached flexible sensors. Without negating existing gain control strategies, it performs a secondary correction to the initial gain parameter range, improving ADC range utilization, effective signal-to-noise ratio, and effective conversion quality margin in subsequent weak signal conditioning and analog-to-digital conversion, while reducing the decrease in data quality margin due to local coupling attenuation. This invention responds to the aforementioned core research point: while existing initial gain parameter ranges can guarantee basic acquisition and conversion, they may not maintain a sufficient quality margin when local coupling attenuation intensifies.

[0081] This invention can be applied to adhesive flexible bioelectrical signal acquisition sensors, wearable weak bioelectrical signal acquisition devices, flexible electrode patches, portable physiological signal acquisition terminals, and sensor systems that require weak signal acquisition and analog-to-digital conversion through adhesive contact interfaces. For application scenarios involving adhesive layer adhesion, flexible clamping, local warping, or slight fluctuations in contact pressure, this invention can provide a more refined scenario-based gain correction mechanism based on existing gain control strategies, exhibiting good engineering adaptability and promotional value.

[0082] Furthermore, in another preferred embodiment provided by the present invention, a bioelectric signal acquisition sensor conditioning and data conversion system is also included.

[0083] The system includes: a data acquisition module, used to acquire the weak bioelectrical signal data output by the current attached flexible sensor in the micro-vibration acquisition scenario of the structural component, and to call the initial gain parameter range configured by the existing gain control strategy;

[0084] The reference sample matching module is used to obtain reference samples from the historical sample library that match the background conditions of the current weak bioelectric signal data output, and to determine the local coupling attenuation intensity and the corresponding effective conversion quality margin of each reference sample within the preset acquisition period.

[0085] Local coupling attenuation intensity is a parameter characterizing the degree to which the coupling transmission efficiency of the weak bioelectrical signal at the contact interface to the sensor input is slightly reduced in one or more local sampling segments due to local contact coupling perturbation.

[0086] The reference value determination module is used to determine the local coupling attenuation reference value that causes the effective conversion quality margin to decrease in a turning point, based on the relationship between the local coupling attenuation intensity and the effective conversion quality margin of each reference sample.

[0087] The gain correction and conversion module is used to calculate the current local coupling attenuation intensity after completing a preset acquisition cycle under the current weak bioelectric signal data output condition. When the current local coupling attenuation intensity exceeds the local coupling attenuation reference value, a gain correction factor is generated based on the difference between the two to correct the initial gain parameter range. The subsequent weak signal conditioning and analog-to-digital conversion are then completed based on the corrected gain parameter range.

[0088] It should be understood that although the steps in the flowcharts of the various embodiments of the present invention are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the various embodiments may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least a portion of the sub-steps or stages of other steps.

[0089] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided by this invention can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0090] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0091] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

[0092] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for conditioning and data conversion of a bioelectrical signal acquisition sensor, characterized in that, The method includes: S1. Obtain the weak bioelectric signal data output by the current attached flexible sensor in the micro-vibration acquisition scenario of the structural component, and call the initial gain parameter range configured by the existing gain control strategy. S2. Obtain reference samples from the historical sample library that match the background conditions of the current weak bioelectric signal data output, and determine the local coupling attenuation intensity and the corresponding effective conversion quality margin of each reference sample within the preset acquisition period. Among them, the local coupling attenuation intensity is a parameter characterizing the degree to which the coupling transmission efficiency of the weak bioelectric signal at the attached contact interface to the sensor input end is slightly reduced due to local contact coupling perturbation in one or more local sampling segments. S3. Based on the relationship between the local coupling attenuation intensity and the effective conversion quality margin of each reference sample, determine the local coupling attenuation reference value that causes the effective conversion quality margin to decrease in a turning point. S4. After completing the preset acquisition cycle under the current weak bioelectric signal data output condition, calculate the current local coupling attenuation intensity. When the current local coupling attenuation intensity exceeds the local coupling attenuation reference value, generate a gain correction factor based on the difference between the two to correct the initial gain parameter range. Then, complete the subsequent weak signal conditioning and analog-to-digital conversion based on the corrected gain parameter range.

2. The method according to claim 1, characterized in that, The background conditions that match the current weak bioelectric signal data output situation mean that the reference sample and the current weak bioelectric signal data output situation are consistent at least in terms of sensor type, attachment or clamping method and initial gain parameter range, and are consistent in at least one of the following: material of the structure under test, acquisition conditions, sampling frequency, weak signal amplitude range and characteristic range of DC bias, low frequency drift and transient impact.

3. The method according to claim 1, characterized in that, The preset acquisition period is the pre-acquisition stage after the current weak bioelectric signal data output is started; the pre-acquisition stage continuously acquires no less than N sampling points according to the preset sampling frequency, and the weak bioelectric signal data corresponding to the N sampling points contains at least one complete signal waveform segment. The complete signal waveform segment is determined by the sampling data between two adjacent zero-crossing points in the same direction, the sampling data between two adjacent peaks, or the sampling data between two adjacent troughs.

4. The method according to claim 1, characterized in that, The local contact coupling micro-perturbation includes at least one of the following: adhesive layer micro-gap, interface micro-slippage, local warping, local debonding, uneven adhesive layer thickness, local rebound of flexible substrate, and micro-fluctuation of flexible clamping pressure.

5. The method according to claim 4, characterized in that, The calculation process of the local coupling attenuation intensity includes: dividing the sample into multiple local sampling segments within a preset acquisition period; determining the amplitude attenuation ratio, energy loss ratio, duration ratio, and waveform correlation reduction ratio of each local sampling segment relative to the reference sampling segment; wherein, the reference sampling segment is a sampling segment within the same preset acquisition period that has not experienced local contact coupling perturbation; and performing weighted fusion based on the amplitude attenuation ratio, energy loss ratio, duration ratio, and waveform correlation reduction ratio to obtain the local coupling attenuation intensity.

6. The method according to claim 1, characterized in that, The effective conversion quality margin is the difference or normalized difference between the actual conversion quality index corresponding to the reference sample and the preset qualified quality threshold; wherein, the actual conversion quality index is determined based on at least two of the following: ADC range utilization, effective signal-to-noise ratio, effective resolution, saturation sampling point ratio, and waveform integrity.

7. The method according to claim 1, characterized in that, The process of determining the local coupling attenuation reference value includes: sorting several reference samples in ascending order of local coupling attenuation intensity to obtain a sample sequence; extracting the effective conversion quality margin change trend corresponding to each reference sample in the sample sequence; when the change trend shows a state of first stabilization, then a turning point and decline, and then tending to stabilize after declining to a low range, the local coupling attenuation intensity corresponding to the first turning point and decline is determined as the local coupling attenuation reference value; when the change trend does not meet the above state, the gain parameter range correction is stopped, and the initial gain parameter range is used.

8. The method according to claim 1, characterized in that, The process of improving the initial gain parameter range includes: after completing a preset acquisition cycle under the current weak bioelectric signal data output condition, determining the current local coupling attenuation intensity within the preset acquisition cycle; determining whether the current local coupling attenuation intensity exceeds the local coupling attenuation reference value; if it exceeds, generating a gain correction factor based on the degree to which the current local coupling attenuation intensity exceeds the local coupling attenuation reference value, and using the gain correction factor to improve the gain parameter in the initial gain parameter range.

9. The method for conditioning and data conversion of a bioelectrical signal acquisition sensor according to claim 8, characterized in that, In step S4, a preset correction function is used to correct the initial gain parameter range; wherein, for any gain value to be corrected within the initial gain parameter range... Corrected gain value satisfy: ； in, The current local coupling attenuation strength, The reference value for local coupling attenuation is greater than zero. This is the gain correction factor. To determine the slope of the decreasing trend of the effective conversion mass margin as a function of the local coupling attenuation intensity after the local coupling attenuation intensity exceeds the local coupling attenuation reference value. and These are the lower limit and upper limit of the safety gain, respectively. Used to limit the corrected gain value within a safe gain range; the corrected gain value is formed by the corrected gain value corresponding to each gain value to be corrected in the initial gain parameter range.

10. A system for conditioning and converting bioelectrical signal acquisition sensors, characterized in that, The system includes: The data acquisition module is used to acquire the weak bioelectric signal data output by the current attached flexible sensor in the micro-vibration acquisition scenario of the structural component, and call the initial gain parameter range configured by the existing gain control strategy. The reference sample matching module is used to obtain reference samples from the historical sample library that match the background conditions of the current weak bioelectric signal data output, and to determine the local coupling attenuation intensity and the corresponding effective conversion quality margin of each reference sample within the preset acquisition period. Local coupling attenuation intensity is a parameter characterizing the degree to which the coupling transmission efficiency of the weak bioelectrical signal at the contact interface to the sensor input is slightly reduced in one or more local sampling segments due to local contact coupling perturbation. The reference value determination module is used to determine the local coupling attenuation reference value that causes the effective conversion quality margin to decrease in a turning point, based on the relationship between the local coupling attenuation intensity and the effective conversion quality margin of each reference sample. The gain correction and conversion module is used to calculate the current local coupling attenuation intensity after completing a preset acquisition cycle under the current weak bioelectric signal data output condition. When the current local coupling attenuation intensity exceeds the local coupling attenuation reference value, a gain correction factor is generated based on the difference between the two to correct the initial gain parameter range. The subsequent weak signal conditioning and analog-to-digital conversion are then completed based on the corrected gain parameter range.

Images