Physiological optical signal credibility evaluation method, device, storage medium and system

Abstract

The invention provides a physiological optical signal credibility evaluation method and device, a storage medium and a system.The method comprises the steps that a plurality of physiological optical signal sequences of the same signal channel are obtained, each physiological optical signal sequence corresponds to a wavelength, and the wavelength of each physiological optical signal sequence corresponds to the wavelength; the plurality of physiological optical signals are arranged according to a collection time sequence and have corresponding wavelengths; performing at least one of correlation evaluation and quality evaluation on the plurality of physiological optical signal sequences; the credibility information of the signal channel is obtained based on the evaluation result of at least one of correlation evaluation and quality evaluation, the correlation evaluation comprises: evaluating the correlation between every two physiological optical signal sequences in the plurality of physiological optical signal sequences, the credibility is in positive correlation with the correlation, and the credibility is not in positive correlation with the correlation. The quality evaluation comprises: evaluating the signal-to-noise ratio quality of each physiological optical signal sequence in the plurality of physiological optical signal sequences, and the credibility is positively correlated with the signal-to-noise ratio quality.

Description

Technical Field

[0001] The present disclosure generally relates to the technical field of medical signal processing, and more specifically, to a method, device, storage medium and system for evaluating the credibility of physiological optical signals. Background Art

[0002] Near-infrared spectral functional imaging technology has been used in academia for many years, but its inherent limitations cannot be ignored: like EEG signals, near-infrared signals are affected by various noises and interferences during the acquisition process, resulting in a signal-to-noise ratio that is significantly lower than MRI (Magnetic Resonance Imaging).

[0003] Currently, the preprocessing of near-infrared functional imaging signals is focused on superficial noise processing such as signal detrending and drift removal, without paying attention to whether the instrument actually captures the hemodynamic feedback signal. This results in a large amount of invalid data in the signal data that serves as the basis for research, weakening the accuracy and reliability of related research. Summary of the invention

[0004] The present disclosure provides a physiological optical signal credibility assessment method, device, storage medium and system, which are used to solve at least one of the above problems.

[0005] According to one aspect of the present disclosure, a method for evaluating the credibility of physiological optical signals is provided, comprising: acquiring multiple physiological optical signal sequences of the same signal channel, wherein each physiological optical signal sequence corresponds to a wavelength and comprises multiple physiological optical signals with corresponding wavelengths arranged in a time order of acquisition; performing at least one of correlation evaluation and quality evaluation on the multiple physiological optical signal sequences; obtaining credibility information of the signal channel based on an evaluation result of at least one of the correlation evaluation and the quality evaluation, wherein the correlation evaluation comprises: evaluating the correlation between two physiological optical signal sequences in the multiple physiological optical signal sequences, wherein the credibility is positively correlated with the correlation, and wherein the quality evaluation comprises: evaluating the signal-to-noise ratio quality of each physiological optical signal sequence in the multiple physiological optical signal sequences, wherein the credibility is positively correlated with the signal-to-noise ratio quality.

[0006] Optionally, the evaluating the correlation between any two of the multiple physiological optical signal sequences includes: based on multiple wavelengths corresponding to the multiple physiological optical signal sequences, combining two different wavelengths into a wavelength pair to obtain multiple wavelength pairs, wherein each wavelength in the multiple wavelengths has a corresponding wavelength pair; for each wavelength pair, calculating a correlation measure of the physiological optical signal sequences of two different wavelengths; calculating the correlation measures of the multiple wavelength pairs to obtain a correlation index of the signal channel; and determining the correlation based on the correlation index.

[0007] Optionally, the multiple wavelengths corresponding to the multiple physiological optical signal sequences are combined into a wavelength pair by two different wavelengths to obtain multiple wavelength pairs, including: determining a wavelength from the multiple wavelengths corresponding to the multiple physiological optical signal sequences as a reference wavelength; and pairing the reference wavelength with each wavelength in the multiple wavelengths except the reference wavelength to obtain the multiple wavelength pairs.

[0008] Optionally, the correlation measure comprises a Pearson correlation coefficient.

[0009] Optionally, determining the correlation according to the correlation index includes: if the correlation index is greater than a correlation threshold, determining the correlation is relevant; otherwise, determining the correlation is irrelevant.

[0010] Optionally, evaluating the signal-to-noise ratio quality of each physiological optical signal sequence in the multiple physiological optical signal sequences includes: respectively calculating the power spectral density of each physiological optical signal sequence in the multiple physiological optical signal sequences; and determining the signal-to-noise ratio quality according to the power spectral density of each physiological optical signal sequence in the multiple physiological optical signal sequences.

[0011] Optionally, determining the signal-to-noise ratio quality according to the power spectral density of each physiological optical signal sequence in the multiple physiological optical signal sequences includes: when a peak value of the power spectral density of each physiological optical signal sequence in the multiple physiological optical signal sequences is greater than a peak threshold, determining that the signal-to-noise ratio quality is passed; otherwise, determining that the signal-to-noise ratio quality is failed.

[0012] Optionally, respectively calculating the power spectral density of each of the multiple physiological optical signal sequences includes: respectively performing filtering processing on each of the multiple physiological optical signal sequences to obtain multiple physiological optical signal sequences within specified frequency ranges; and respectively performing power spectral density calculation processing on each of the physiological optical signal sequences within the multiple specified frequency ranges to obtain the power spectral density of each of the multiple physiological optical signal sequences.

[0013] Optionally, the acquiring of multiple physiological optical signal sequences of the same signal channel includes: acquiring multiple physiological light intensity signal sequences of the same signal channel, wherein each physiological light intensity signal sequence corresponds to a wavelength and includes multiple physiological light intensity signals with corresponding wavelengths arranged in chronological order of acquisition; for each physiological light intensity signal sequence, taking the physiological light intensity signal at a reference moment as a reference signal, performing optical density calculation processing on the physiological light intensity signal sequence to obtain an optical density signal sequence as the physiological optical signal sequence.

[0014] According to another aspect of the present disclosure, a physiological optical signal credibility assessment device is provided, comprising: an acquisition unit, configured to acquire multiple physiological optical signal sequences of the same signal channel, wherein each physiological optical signal sequence corresponds to a wavelength and comprises multiple physiological optical signals with corresponding wavelengths arranged in a time order of acquisition; an assessment unit, configured to perform at least one of correlation assessment and quality assessment on the multiple physiological optical signal sequences; a determination unit, configured to obtain credibility information of the signal channel based on an assessment result of at least one of the correlation assessment and the quality assessment, wherein the correlation assessment comprises: assessing the correlation between two physiological optical signal sequences in the multiple physiological optical signal sequences, wherein the credibility is positively correlated with the correlation, and wherein the quality assessment comprises: assessing the signal-to-noise ratio quality of each physiological optical signal sequence in the multiple physiological optical signal sequences, wherein the credibility is positively correlated with the signal-to-noise ratio quality.

[0015] Optionally, the operation of evaluating the correlation between any two of the multiple physiological optical signal sequences performed by the evaluation unit includes: based on the multiple wavelengths corresponding to the multiple physiological optical signal sequences, combining two different wavelengths into a wavelength pair to obtain multiple wavelength pairs, wherein each wavelength in the multiple wavelengths has a corresponding wavelength pair; for each wavelength pair, calculating a correlation measure of the physiological optical signal sequences of two different wavelengths; calculating the correlation measures of the multiple wavelength pairs to obtain a correlation index of the signal channel; and determining the correlation based on the correlation index.

[0016] Optionally, the operation performed by the evaluation unit to group two different wavelengths into a wavelength pair based on the multiple wavelengths corresponding to the multiple physiological optical signal sequences to obtain the multiple wavelength pairs includes: determining a wavelength from the multiple wavelengths corresponding to the multiple physiological optical signal sequences as a reference wavelength; and pairing the reference wavelength with each wavelength in the multiple wavelengths except the reference wavelength to obtain the multiple wavelength pairs.

[0017] Optionally, the correlation measure comprises a Pearson correlation coefficient.

[0018] Optionally, the operation of determining the correlation according to the correlation index performed by the evaluation unit includes: if the correlation index is greater than a correlation threshold, determining that the correlation is relevant, otherwise determining that the correlation is irrelevant.

[0019] Optionally, the operation of evaluating the signal-to-noise ratio quality of each of the multiple physiological optical signal sequences performed by the evaluation unit includes: respectively calculating the power spectral density of each of the multiple physiological optical signal sequences; and determining the signal-to-noise ratio quality based on the power spectral density of each of the multiple physiological optical signal sequences.

[0020] Optionally, the operation of determining the signal-to-noise ratio quality according to the power spectral density of each physiological optical signal sequence in the multiple physiological optical signal sequences performed by the evaluation unit includes: when the peak value of the power spectral density of each physiological optical signal sequence in the multiple physiological optical signal sequences is greater than a peak threshold, determining that the signal-to-noise ratio quality is passed; otherwise, determining that the signal-to-noise ratio quality is failed.

[0021] Optionally, the operation of respectively calculating the power spectral density of each of the multiple physiological optical signal sequences performed by the evaluation unit includes: respectively performing filtering processing on each of the multiple physiological optical signal sequences to obtain multiple physiological optical signal sequences within specified frequency ranges; and respectively performing power spectral density calculation processing on each of the physiological optical signal sequences within the multiple specified frequency ranges to obtain the power spectral density of each of the multiple physiological optical signal sequences.

[0022] Optionally, the acquisition unit is further configured to: acquire multiple physiological light intensity signal sequences of the same signal channel, wherein each physiological light intensity signal sequence corresponds to a wavelength and includes multiple physiological light intensity signals with corresponding wavelengths arranged in the order of collection time; for each physiological light intensity signal sequence, taking the physiological light intensity signal at a reference moment as a reference signal, performing optical density calculation processing on the physiological light intensity signal sequence to obtain an optical density signal sequence as the physiological optical signal sequence.

[0023] According to another aspect of the present disclosure, a computer-readable storage medium storing instructions is provided, wherein when the instructions are executed by at least one computing device, the at least one computing device is prompted to perform the physiological optical signal credibility assessment method as described above.

[0024] According to another aspect of the present disclosure, a system is provided, including at least one computing device and at least one storage device storing instructions, wherein when the instructions are executed by the at least one computing device, the at least one computing device is prompted to perform the physiological optical signal credibility assessment method as described above.

[0025] According to another aspect of the present disclosure, a computer program product is provided, comprising instructions, wherein when the instructions are executed by at least one computing device, the at least one computing device is prompted to perform the physiological optical signal credibility assessment method as described above.

[0026] According to the physiological optical signal credibility assessment method, device, storage medium and system of the exemplary embodiments of the present disclosure, by performing at least one assessment on the physiological optical signal sequence of multiple wavelengths of the same signal channel, it is possible to assess the correlation between signals of different wavelengths in the collected signal and / or the signal-to-noise ratio quality of each wavelength signal, thereby reflecting the overall credibility of the collected signal, helping to eliminate invalid signal data with low credibility when conducting relevant research, reducing the impact of interference signals, and improving the accuracy and reliability of relevant research.

[0027] Additional aspects and / or advantages of the present general inventive concept will be set forth in part in the following description and in part will be apparent from the description or may be learned through practice of the present general inventive concept. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] These and / or other aspects and advantages of the present disclosure will become clear and more easily understood from the following description of the embodiments in conjunction with the accompanying drawings.

[0029] Figure 1 is a flow chart showing a method for evaluating the credibility of a physiological optical signal according to an exemplary embodiment of the present disclosure.

[0030] Figure 2 Schematic diagram showing the software and hardware connection relationship of the physiological optical signal credibility system according to a specific embodiment of the present disclosure.

[0031] Figure 3 is a schematic diagram showing a power spectral density curve according to a specific embodiment of the present disclosure.

[0032] Figure 4 is a block diagram showing a physiological optical signal credibility assessment device according to an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0033] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of the embodiments of the present invention as defined by the claims and their equivalents. Various specific details are included to assist in understanding, but these details are considered to be exemplary only. Therefore, one of ordinary skill in the art will recognize that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present invention. In addition, descriptions of well-known functions and structures are omitted for clarity and brevity.

[0034] It should be noted that the phrase "at least one of the items" in the present disclosure includes three types of parallel situations: "any one of the items", "a combination of any number of the items", and "all of the items". For example, "including at least one of A and B" includes the following three types of parallel situations: (1) including A; (2) including B; (3) including A and B. Another example is "executing at least one of step 1 and step 2" which means the following three types of parallel situations: (1) executing step 1; (2) executing step 2; (3) executing step 1 and step 2.

[0035] Refer to the following Figures 1 to 3 A physiological optical signal credibility assessment method, device, storage medium and system according to exemplary embodiments of the present disclosure are described in detail.

[0036] Figure 1 is a flow chart showing a method for evaluating the credibility of a physiological optical signal according to an exemplary embodiment of the present disclosure. The method for evaluating the credibility of a physiological optical signal according to an exemplary embodiment of the present disclosure can be implemented in a computing device with sufficient computing power.

[0037] Reference Figure 1 In step S101, multiple physiological optical signal sequences of the same signal channel are acquired.

[0038] Each physiological optical signal sequence corresponds to a wavelength, and includes multiple physiological optical signals with corresponding wavelengths arranged in the order of acquisition time. Specifically, taking the acquisition of near-infrared brain imaging signals as an example, near infrared spectroscopy (NIRS) is a spectral analysis technology that can measure the absorption, reflection or transmission characteristics of substances in the near-infrared wavelength range (usually 600nm-900nm). In the field of mental psychology, by using NIRS to illuminate the prefrontal cortex of the brain, observing the concentration changes of oxygenated hemoglobin and deoxygenated hemoglobin in the prefrontal cortex of the brain during the verbal fluency task (VFT), near-infrared brain imaging data can be obtained, which can reflect the emotional characteristics of the subjects and their ability to regulate emotions. Near-infrared brain imaging signals need to be matched with corresponding equipment to realize acquisition, such as but not limited to prefrontal headgear, probe connection line, and near-infrared brain imaging instrument. There are multiple optical probes on the headgear, including a light source probe (for emitting near-infrared light) and a detector probe (for receiving light reflected or scattered back from brain tissue). These optical probes are distributed on the headgear and arranged at a certain interval. The near-infrared brain imaging instrument is connected to the optical probe through a probe connection line. The control module of the near-infrared brain imaging instrument controls the light source probe to emit near-infrared light of a specific wavelength. After the near-infrared light is scattered and absorbed by the brain tissue, the reflected light signal is received by the detector probe. These signals are transmitted to the data acquisition module of the near-infrared brain imaging instrument through the probe connection line, and finally processed and analyzed to reflect the changes in blood oxygen in the cerebral cortex. For the optical probe, the optical signal measurement path from a light source probe to a detector probe is called a signal channel. In other words, a signal channel is composed of a light source probe and a detector probe. For example, if the headgear is provided with 3 light source probes and 4 detector probes, 12 signal channels can be formed in theory, which can cover different areas of the brain and be used to measure the changes in blood oxygen at multiple locations at the same time. For each signal channel, signal acquisition is usually performed according to the set sampling frequency, and multiple signals of different wavelengths can be acquired by adopting specific technologies (for example, including but not limited to frequency division multiplexing, time division multiplexing, continuous wave method, phase-locked photon counting and other technologies, which are mature technologies in this field and will not be elaborated here). These signals are grouped according to wavelength, and the signals collected at different times under the same wavelength constitute a group. This group of signals is arranged into a sequence according to the time order of collection, and a near-infrared brain imaging signal sequence is obtained, which corresponds to a physiological optical signal sequence here. It should be understood that in addition to near-infrared brain imaging signals, other physiological signals collected using optical principles can also be used as physiological optical signals in the present disclosure, and their credibility is evaluated using the physiological optical signal credibility evaluation method of the embodiment of the present disclosure.

[0039] In some embodiments, optionally, step S101 includes: obtaining multiple physiological light intensity signal sequences of the same signal channel, wherein each physiological light intensity signal sequence corresponds to a wavelength and includes multiple physiological light intensity signals with corresponding wavelengths arranged in the order of the time of acquisition; for each physiological light intensity signal sequence, taking the physiological light intensity signal at the reference time as the reference signal, performing optical density calculation processing on the physiological light intensity signal sequence to obtain an optical density signal sequence as a physiological optical signal sequence. The physiological light intensity signal here is a signal directly collected by a signal acquisition device (for example, including but not limited to a near-infrared brain imaging instrument), and the optical density signal is a dimensionless quantity obtained based on the physiological light intensity signal. It is a logarithmic value that represents the attenuation degree of light when passing through a material and can be used to characterize the material's ability to absorb light. By using the optical density signal sequence as a physiological light intensity signal sequence, the concentration change of hemoglobin can be calculated more accurately, thereby reflecting the physiological activity of the brain. As an example, the starting time of each physiological light intensity signal sequence can be used as a reference time, that is, the first physiological light intensity signal in the sequence can be used as a reference signal. Of course, other times can also be selected as reference times, and the present disclosure does not limit this.

[0040] Specifically, the optical density signal sequence can be calculated based on the modified Beer-Lambert Law. The modified Beer-Lambert Law is a formula that describes the relationship between the amount of absorption of light and multiple factors when it passes through a substance. The original Beer's Law describes the linear relationship between the absorbance of light (or the logarithm of the transmittance) and its concentration and path length when light propagates in a uniform, non-scattering medium. The modified Beer-Lambert Law is usually used to describe complex situations in practical applications, such as considering scattering effects, refraction and reflection under non-ideal conditions (such as when there are suspended particles in the solution or the solvent itself has color). When calculating the optical density signal sequence, specifically for a physiological light intensity signal sequence, the ratio of each physiological light intensity signal to the reference signal can be calculated as the transmittance, and then the logarithm of the transmittance can be calculated to obtain the optical density signal. These optical density signals are arranged in the order of the corresponding physiological light intensity signals (i.e., the time order of acquisition) to form an optical density signal sequence.

[0041] In some other embodiments, optionally, step S101 includes: acquiring multiple physiological light intensity signal sequences of the same signal channel as physiological optical signal sequences.

[0042] In step S102, at least one of correlation evaluation and quality evaluation is performed on a plurality of physiological optical signal sequences.

[0043] Specifically, the correlation evaluation includes: evaluating the correlation between two physiological optical signal sequences in a plurality of physiological optical signal sequences, wherein the credibility is positively correlated with the correlation. The quality evaluation includes: evaluating the signal-to-noise ratio quality of each physiological optical signal sequence in a plurality of physiological optical signal sequences, wherein the credibility is positively correlated with the signal-to-noise ratio quality.

[0044] In step S103, credibility information of the signal channel is obtained based on the evaluation result of at least one of the correlation evaluation and the quality evaluation.

[0045] As an example, all evaluation results may be directly summarized as credibility information, or all evaluation results may be further processed to obtain credibility information, which is not limited in the present disclosure.

[0046] According to the physiological optical signal credibility assessment method of the exemplary embodiment of the present disclosure, by performing at least one of the above assessments on the physiological optical signal sequences of multiple wavelengths of the same signal channel, it is possible to assess the correlation between signals of different wavelengths in the collected signals and / or the signal-to-noise ratio quality of each wavelength signal, thereby reflecting the overall credibility of the collected signals, helping to eliminate invalid signal data with low credibility when conducting relevant research, reducing the impact of interference signals, and improving the accuracy and reliability of relevant research.

[0047] As an example, when processing physiological optical signals to assist medical diagnosis or research, it is usually necessary to preprocess the signals first, for example, including but not limited to detrending and de-drifting. The physiological optical signal credibility assessment method according to the exemplary embodiment of the present disclosure can be performed before preprocessing the physiological optical signals, so there is no need to perform preprocessing on physiological optical signals with low credibility, which can effectively reduce unnecessary preprocessing calculations and improve subsequent data processing efficiency. Of course, in actual implementation, the timing of executing the method can also be determined according to specific needs, and the present disclosure does not limit this.

[0048] It should be understood that the collection of physiological optical signals often lasts for a period of time. For example, for near-infrared brain imaging signals, signals will be continuously collected while the subjects are performing speech process tasks. Therefore, according to the physiological optical signal credibility assessment method of the exemplary embodiment of the present disclosure, it can be performed at regular intervals during the signal collection process, that is, the credibility of the latest collected signal or all signals collected so far can be assessed at regular intervals, or the assessment can be performed after all signals are collected. The present disclosure does not impose any restrictions on this.

[0049] Next, the relevance assessment is introduced.

[0050] Optionally, evaluating the correlation between two physiological optical signal sequences in a plurality of physiological optical signal sequences includes: based on a plurality of wavelengths corresponding to the plurality of physiological optical signal sequences, forming a wavelength pair with two different wavelengths to obtain a plurality of wavelength pairs, wherein each wavelength in the plurality of wavelengths has a corresponding wavelength pair; for each wavelength pair, calculating the correlation measure of the physiological optical signal sequences of two different wavelengths; statistically calculating the correlation measures of the plurality of wavelength pairs to obtain the correlation index of the signal channel; and determining the correlation according to the correlation index. Considering that if the collected physiological optical signal is valid, the signal sequences of different wavelengths in the same signal channel should have a high correlation. Based on this, the present disclosure calculates the signal correlation measure between two wavelengths for the physiological optical signal sequences of different wavelengths in the same signal channel and performs statistics to obtain the correlation index of the signal channel, which can quantitatively reflect whether the physiological optical signal collected by the signal channel is valid as a whole by means of the correlation degree between the wavelengths, and realizes an objective evaluation of the credibility of the physiological optical signal collected by a single signal channel. In addition, by first determining a plurality of wavelength pairs and then calculating the correlation measure for the two wavelengths in each wavelength pair, the reliability of the calculation process can be guaranteed and the accuracy of the evaluation can be improved.

[0051] Regarding how to obtain multiple wavelength pairs, optionally, this step includes: determining a wavelength from multiple wavelengths corresponding to multiple physiological optical signal sequences as a reference wavelength; and pairing the reference wavelength with each wavelength in the multiple wavelengths except the reference wavelength to obtain multiple wavelength pairs. By combining a reference wavelength with other wavelengths to form wavelength pairs, that is, forming (N-1) wavelength pairs when there are N wavelengths in total, each wavelength can be indirectly paired with other wavelengths through the reference wavelength as a medium, thereby achieving the evaluation of the correlation between signal sequences of any two wavelengths and forming as few wavelength pairs as possible, reducing the amount of calculation and improving the calculation efficiency. As an example, the reference wavelength can be randomly selected from multiple wavelengths, or a specific wavelength, such as the minimum wavelength, can be selected, and the present disclosure does not limit this. Of course, other reasonable methods can also be used to obtain multiple wavelength pairs, such as but not limited to pairing each wavelength with each other wavelength to obtain when there are N wavelengths in total. wavelength pairs to achieve full pairing. For example, each wavelength is allowed to participate in only one wavelength pair, but when the total number of wavelengths is an odd number, one of the wavelengths is allowed to participate in two wavelength pairs. When there are N wavelengths in total and N is an even number, N / 2 wavelength pairs are obtained. When there are N wavelengths in total and N is an odd number, (N+1) / 2 wavelength pairs are obtained, so as to minimize the number of wavelength pairs and reduce the amount of calculation.

[0052] Regarding the correlation measure, optionally, the correlation measure includes the Pearson correlation coefficient. The Pearson correlation coefficient is a statistical method for measuring the strength and direction of the linear relationship between two variables, named after the British biostatistician Karl Friedrich Pearson. The Pearson correlation coefficient is obtained by calculating the standardized covariance of two variables and their respective standard deviations. By using the Pearson correlation coefficient, efficient quantification of the correlation between the signal sequences of two wavelengths is achieved. Of course, the embodiments of the present disclosure may also adopt other correlation measures, such as but not limited to cosine similarity and Euclidean distance.

[0053] Regarding how to calculate the correlation measures of multiple wavelength pairs, optionally, statistical values ​​such as the average, mode, median, and specified quantile of the correlation measures of multiple wavelength pairs can be calculated, and the present disclosure does not limit this.

[0054] Regarding how to determine the correlation based on the correlation index, optionally, this step includes: when the correlation index is greater than a correlation threshold, determining that the correlation is relevant, otherwise determining that the correlation is irrelevant. By setting the correlation threshold as a reference value of the correlation index indicating sufficient correlation, it is possible to conveniently implement a qualitative evaluation based on a quantitative evaluation, which facilitates the intuitive display of the evaluation results. It should be understood that the correlation threshold can be determined through theoretical analysis and experiments, and the larger its value is, the stricter the evaluation standard for the correlation is. The present disclosure does not limit the specific value of the correlation threshold and the specific determination method.

[0055] Next, the signal-to-noise ratio quality assessment is introduced.

[0056] Optionally, evaluating the signal-to-noise quality of each physiological optical signal sequence in the multiple physiological optical signal sequences includes: calculating the power spectral density of each physiological optical signal sequence in the multiple physiological optical signal sequences respectively; determining the signal-to-noise quality according to the power spectral density of each physiological optical signal sequence in the multiple physiological optical signal sequences. Power spectral density (PSD) is a function that describes the power distribution of a signal in the frequency domain. It represents the average power in a unit frequency band and is usually represented by S(f) or S(ω), where f is the frequency and ω is the angular frequency. It describes the characteristics of how the energy of a signal is distributed with frequency and provides an important tool for conversion from the time domain to the frequency domain. By understanding the power spectral density of a signal, it is possible to better analyze and design systems, filters, and perform applications such as communications. Although the size of the power spectral density does not directly represent the size of the signal-to-noise ratio (SNR), it is closely related to the signal-to-noise ratio and is easier to calculate than the signal-to-noise ratio. By determining the signal-to-noise ratio quality based on the power spectral density, compared with directly calculating the signal-to-noise ratio, the signal quality assessment requirement can be met with a smaller amount of calculation, thereby improving the assessment efficiency. Of course, in other embodiments, other reasonable forms may also be used to assess the signal-to-noise ratio quality, including but not limited to directly calculating the signal-to-noise ratio.

[0057] Regarding the calculation of power spectral density, optionally, this step includes: filtering each physiological optical signal sequence in a plurality of physiological optical signal sequences respectively to obtain a plurality of physiological optical signal sequences within a specified frequency range; performing power spectral density calculation processing on each physiological optical signal sequence in a plurality of physiological optical signal sequences within a specified frequency range respectively to obtain the power spectral density of each physiological optical signal sequence in a plurality of physiological optical signal sequences. By first filtering the time domain signal (i.e., a plurality of physiological optical signal sequences) for a specified frequency range, and then calculating the power spectral density of the filtered signal sequence, it is possible to only consider the signal components within the specified frequency range when calculating the power spectral density, so that the calculation result more accurately reflects the power distribution within the specified frequency range. Of course, filtering processing may be omitted, and power spectral density calculation processing may be performed directly on each acquired physiological optical signal sequence, and the power spectral density thus obtained may be further intercepted with the result within the specified frequency range (its accuracy is lower than the first filtering embodiment described above), which is also an implementation method of the present disclosure. Power spectral density calculation processing belongs to a mature technology in the art and will not be elaborated here. It should be understood that the specified frequency range can be set as needed, for example, including but not limited to 0.1 Hz to 3 Hz, and the present disclosure is not limited to this.

[0058] Regarding how to determine the signal-to-noise ratio quality, optionally, this step includes: when the peak value of the power spectral density of each physiological optical signal sequence in a plurality of physiological optical signal sequences is greater than the peak value threshold, the signal-to-noise ratio quality is determined to be passed, otherwise the signal-to-noise ratio quality is determined to be failed. On the one hand, by setting the peak value threshold as the peak value reference value of the power spectral density indicating that the signal-to-noise ratio quality of a single physiological optical signal sequence is sufficient, the signal-to-noise ratio quality of the signal can be evaluated more reliably using the power spectral density without calculating the signal-to-noise ratio, and a qualitative evaluation based on a quantitative evaluation can be conveniently implemented, which is convenient for intuitively displaying the evaluation results. On the other hand, by using the peak values ​​of the power spectral density of a plurality of physiological optical signals to be sufficiently large as the condition for evaluating the signal-to-noise ratio quality of the overall signal, the quality evaluation results of signal sequences of different wavelengths can be conveniently summarized, and the reliability of the overall quality evaluation results can be fully guaranteed. It should be understood that the peak value threshold can be determined by theoretical analysis and experiments, and the larger the value, the stricter the evaluation standard for the signal-to-noise ratio quality. The present disclosure does not limit the specific value of the peak value threshold and the specific determination method. It should also be understood that, in actual implementation, for the power spectrum density of each physiological optical signal sequence, the peak value can be calculated, and then the peak value can be compared with the peak value threshold value, or the peak value can be not calculated. As long as it is determined that there is a value greater than the peak value threshold value in the power spectrum density, it is considered that the peak value must also be greater than the peak value threshold value. This is the implementation method of the present disclosure. Of course, other reasonable embodiments other than the peak values ​​of each power spectrum density being greater than the peak value threshold value can also be used to determine the signal-to-noise ratio quality, and the present disclosure does not limit this.

[0059] Next, a method for evaluating the credibility of physiological optical signals according to a specific embodiment of the present disclosure is introduced.

[0060] This specific embodiment is used to evaluate the credibility of near-infrared brain imaging signals. The signals are affected by various noises and interferences during the acquisition process, including, for example, the following five influences.

[0061] (1) The sensor is exposed to ambient light or interfered by the magnetic field.

[0062] (2) The sensor has no contact with the scalp.

[0063] (3) Even if the sensor is in good contact with the scalp, the adjacent infrared laser is blocked by the hair, resulting in a weak detection signal or no detection signal.

[0064] (4) There is no appreciable blood vessel distribution at the depth of the detection location where the sensor is pointed.

[0065] (5) The sensor fiber or laser fiber is damaged, aged, or exposed, resulting in signals with no physiological significance.

[0066] This specific embodiment can identify the signal channel with the above problems (1) to (5) before preprocessing the data, and output whether the signal channel meets the standard of reflecting the hemodynamic characteristics, thereby reducing the impact of interference signals.

[0067] This specific embodiment is implemented based on a physiological optical signal credibility system. Figure 2 The figure shows the connection relationship between the hardware and software of the system. Figure 2 As shown, the near-infrared brain imaging instrument 20 can collect brain function signals of the subject and output a physiological light intensity (Optical Intensity) signal sequence. The evaluation method obtains multiple physiological light intensity signal sequences of the same signal channel from a data source (near-infrared brain imaging instrument 20) in real time or non-real time, and obtains the evaluation result (credibility information) after a series of data processing. The evaluation includes correlation evaluation and quality evaluation. The execution order of the two evaluations is not limited, and they can be executed successively (for example, including but not limited to following Figure 2 The evaluation results are output to a screen 30. The operator can improve the quality of the research data by adjusting the sensor in real time or by analyzing the data through the output of the system in the post-analysis of the data based on the evaluation results displayed on the screen 30.

[0068] The specific process of a series of data processing is as follows.

[0069] First, the system receives a physiological light intensity signal sequence from the near-infrared brain imaging instrument 20. Assuming that the instrument has a total of C channels, containing N wavelengths of independent near-infrared light, the system receives a total of C×N signal sequences. The system first sets the first signal value in each sequence as the reference signal R of the sequence, and then calculates each physiological light intensity signal OI(t) in the sequence based on the Beer-Lambert law modified by the reference signal to obtain the corresponding optical density signal OD(t), which is expressed as: OD(t) = log(OI(t) / R).

[0070] The physiological light intensity signal sequences OD of all wavelengths of the same signal channel are respectively recorded as ODλ1, ODλ2, ..., ODλN.

[0071] Then, the correlation evaluation is performed. Since the blood tissue in the human body shows a certain absorption pattern when absorbing near-infrared light, if the signals of all wavelengths successfully reflect the absorption, the positive correlation between the signals of two wavelengths will be high. Based on this, the Pearson correlation coefficient PC can be used to calculate all paired OD signals and obtain the correlation index E1: E1 = (1 / (N-1)) ×∑PCλ(a,b).

[0072] Among them, N wavelengths constitute (N-1) wavelength pairs, λ(a, b) represents a wavelength pair, and PCλ(a, b) represents the Pearson correlation coefficient of the OD signal sequences of two different wavelengths in the wavelength pair.

[0073] Set the correlation threshold T1. If E1>T1, the signal is considered to have passed the correlation evaluation. The larger T1 is, the stricter the correlation evaluation is. Correlation evaluation can effectively eliminate the signal interference caused by (3) and (5).

[0074] Next, quality assessment is performed. The system will identify which OD signal sequences contain real physiological signals with a high signal-to-noise ratio by analyzing the distribution of the power spectrum density and characteristic peaks of the OD signal sequence of each wavelength. For each OD signal sequence, filtering is first performed (retaining signals within 0.1Hz to 3Hz), then the power spectrum density is calculated, and finally the signal-to-noise ratio quality E2 is obtained through analysis.

[0075] Generally speaking, the power spectral density will show a peak at the main frequency component (e.g. Figure 3 As shown). If the power spectrum density of each OD signal sequence has a peak higher than the peak threshold T2, that is, the peak value is higher than the peak threshold T2, then the signal-to-noise ratio quality E2 is considered to be passed, otherwise it is considered to be failed. In other words, as long as there is a peak value of the power spectrum density of an OD signal sequence that is less than or equal to the peak threshold T2, the signal-to-noise ratio quality E2 is considered to be failed.

[0076] In actual experiments, the larger the peak threshold T2 is, the stricter the quality assessment is. Quality assessment can effectively eliminate the signal interference caused by (1), (2), and (4).

[0077] Finally, the system displays the pass / fail status of all signal channels on screen 30 using a list such as that shown in Table 1 below, and users can adjust their research strategies through the list.

[0078] Table 1 Credibility information list

[0079] The list can be updated in real time based on the data obtained in a time period. As an example, when updating, only the data of the latest time period is processed and output, that is, only the credibility of the physiological light intensity signal collected in the latest time period is evaluated, and the credibility information of the evaluation is output. The list can also be updated after all data are transmitted.

[0080] Figure 4 is a block diagram showing a physiological optical signal credibility assessment device according to an exemplary embodiment of the present disclosure.

[0081] Reference Figure 4 The physiological optical signal credibility assessment device 400 includes an acquisition unit 401 , an assessment unit 402 , and a determination unit 403 .

[0082] The acquisition unit 401 may acquire multiple physiological optical signal sequences of the same signal channel, wherein each physiological optical signal sequence corresponds to a wavelength and includes multiple physiological optical signals with corresponding wavelengths arranged in a time sequence of acquisition.

[0083] The evaluation unit 402 may perform at least one of correlation evaluation and quality evaluation on the multiple physiological optical signal sequences. The correlation evaluation includes: evaluating the correlation between two physiological optical signal sequences in the multiple physiological optical signal sequences, wherein the credibility is positively correlated with the correlation. The quality evaluation includes: evaluating the signal-to-noise ratio quality of each physiological optical signal sequence in the multiple physiological optical signal sequences, wherein the credibility is positively correlated with the signal-to-noise ratio quality.

[0084] The determination unit 403 may obtain the credibility information of the signal channel based on the evaluation result of at least one of the correlation evaluation and the quality evaluation.

[0085] Optionally, the operation of evaluating the correlation between any two physiological optical signal sequences in a plurality of physiological optical signal sequences performed by the evaluation unit 402 includes: based on a plurality of wavelengths corresponding to the plurality of physiological optical signal sequences, combining two different wavelengths into a wavelength pair to obtain a plurality of wavelength pairs, wherein each wavelength in the plurality of wavelengths has a corresponding wavelength pair; for each wavelength pair, calculating a correlation measure of the physiological optical signal sequences of two different wavelengths; calculating the correlation measures of the plurality of wavelength pairs to obtain a correlation index of the signal channel; and determining the correlation based on the correlation index.

[0086] Optionally, the operation performed by the evaluation unit 402 to group two different wavelengths into a wavelength pair based on the multiple wavelengths corresponding to the multiple physiological optical signal sequences to obtain the multiple wavelength pairs includes: determining a wavelength from the multiple wavelengths corresponding to the multiple physiological optical signal sequences as a reference wavelength; and pairing the reference wavelength with each wavelength in the multiple wavelengths except the reference wavelength to obtain multiple wavelength pairs.

[0087] Optionally, the correlation measure comprises a Pearson correlation coefficient.

[0088] Optionally, the operation of determining the correlation according to the correlation index performed by the evaluation unit 402 includes: if the correlation index is greater than a correlation threshold, determining the correlation is relevant, otherwise determining the correlation is irrelevant.

[0089] Optionally, the operation of evaluating the signal-to-noise ratio quality of each physiological optical signal sequence in the multiple physiological optical signal sequences performed by the evaluation unit 402 includes: respectively calculating the power spectral density of each physiological optical signal sequence in the multiple physiological optical signal sequences; and determining the signal-to-noise ratio quality according to the power spectral density of each physiological optical signal sequence in the multiple physiological optical signal sequences.

[0090] Optionally, the operation of determining the signal-to-noise ratio quality according to the power spectral density of each physiological optical signal sequence in the multiple physiological optical signal sequences performed by the evaluation unit 402 includes: when the peak value of the power spectral density of each physiological optical signal sequence in the multiple physiological optical signal sequences is greater than the peak threshold, determining that the signal-to-noise ratio quality is passed; otherwise, determining that the signal-to-noise ratio quality is failed.

[0091] Optionally, the operation of respectively calculating the power spectral density of each of the multiple physiological optical signal sequences performed by the evaluation unit 402 includes: respectively performing filtering processing on each of the multiple physiological optical signal sequences to obtain multiple physiological optical signal sequences within a specified frequency range; and respectively performing power spectral density calculation processing on each of the multiple physiological optical signal sequences within the specified frequency range to obtain the power spectral density of each of the multiple physiological optical signal sequences.

[0092] Optionally, the acquisition unit 401 can also: acquire multiple physiological light intensity signal sequences of the same signal channel, wherein each physiological light intensity signal sequence corresponds to a wavelength and includes multiple physiological light intensity signals with corresponding wavelengths arranged in the order of collection time; for each physiological light intensity signal sequence, the physiological light intensity signal at a reference moment is used as a reference signal, and optical density calculation processing is performed on the physiological light intensity signal sequence to obtain an optical density signal sequence as a physiological optical signal sequence.

[0093] The above has been referred to Figures 1 to 4 A method and apparatus for evaluating the credibility of a physiological optical signal according to exemplary embodiments of the present disclosure are described.

[0094] Figure 4 Each unit in the physiological optical signal credibility assessment device shown can be configured as software, hardware, firmware or any combination of the above items to perform specific functions. For example, each unit can correspond to a dedicated integrated circuit, or a pure software code, or a module combining software and hardware. In addition, one or more functions implemented by each unit can also be uniformly executed by components in a physical entity device (e.g., a processor, a client or a server, etc.).

[0095] In addition, refer to Figure 1The physiological optical signal credibility assessment method described can be implemented by a program (or instruction) recorded on a computer-readable storage medium. For example, according to an exemplary embodiment of the present disclosure, a computer-readable storage medium storing instructions can be provided, wherein when the instructions are executed by at least one computing device, the at least one computing device is prompted to perform the physiological optical signal credibility assessment method according to the present disclosure.

[0096] The computer program in the computer-readable storage medium can be run in an environment deployed in a computer device such as a client, a host, an agent device, a server, etc. It should be noted that the computer program can also be used to perform additional steps in addition to the above steps or perform more specific processing when performing the above steps. The contents of these additional steps and further processing have been described in reference to Figure 1 It is mentioned in the description of the related method, so it will not be repeated here to avoid repetition.

[0097] It should be noted that the various units in the physiological optical signal credibility assessment device according to the exemplary embodiment of the present disclosure can completely rely on the operation of the computer program to realize the corresponding functions, that is, each unit corresponds to each step in the functional architecture of the computer program, so that the entire system is called through a special software package (for example, lib library) to realize the corresponding function.

[0098] on the other hand, Figure 4 The various units shown may also be implemented by hardware, software, firmware, middleware, microcode, or any combination thereof. When implemented by software, firmware, middleware, or microcode, the program code or code segment for performing the corresponding operation may be stored in a computer-readable medium such as a storage medium, so that the processor may perform the corresponding operation by reading and running the corresponding program code or code segment.

[0099] For example, an exemplary embodiment of the present disclosure may also be implemented as a computing device, which includes a storage component and a processor, wherein a set of computer executable instructions is stored in the storage component, and when the set of computer executable instructions is executed by the processor, the method for assessing the credibility of physiological optical signals according to the exemplary embodiment of the present disclosure is executed.

[0100] Specifically, the computing device can be deployed in a server or client, or can be deployed on a node device in a distributed network environment. In addition, the computing device can be a PC, a tablet device, a personal digital assistant, a smart phone, a web physiological optical signal credibility assessment, or other devices capable of executing the above instruction set.

[0101] Here, the computing device is not necessarily a single computing device, but may also be any device or circuit collection that can execute the above instructions (or instruction sets) individually or jointly. The computing device may also be part of an integrated control system or system manager, or may be configured as a portable electronic device that is interconnected with a local or remote (e.g., via wireless transmission) interface.

[0102] In a computing device, a processor may include a central processing unit (CPU), a graphics processing unit (GPU), a programmable logic device, a dedicated processor system, a microcontroller, or a microprocessor. By way of example and not limitation, a processor may also include an analog processor, a digital processor, a microprocessor, a multi-core processor, a processor array, a network processor, etc.

[0103] According to the physiological optical signal credibility assessment method of the exemplary embodiment of the present disclosure, some operations described in the method can be implemented by software, some operations can be implemented by hardware, and in addition, these operations can also be implemented by a combination of software and hardware.

[0104] The processor may execute instructions or codes stored in one of the storage components, which may also store data. Instructions and data may also be sent and received over a network via a network interface device, which may employ any known transmission protocol.

[0105] The storage component may be integrated with the processor, for example, RAM or flash memory is arranged within an integrated circuit microprocessor, etc. In addition, the storage component may include a separate device, such as an external disk drive, a storage array, or any other storage device that can be used by a database system. The storage component and the processor may be operatively coupled, or may communicate with each other, such as through an I / O port, a network connection, etc., so that the processor can read files stored in the storage component.

[0106] In addition, the computing device may also include a video display (such as a liquid crystal display) and a user interaction interface (such as a keyboard, a mouse, a touch input device, etc.) All components of the computing device may be connected to each other via a bus and / or a network.

[0107] The physiological optical signal credibility assessment method according to the exemplary embodiment of the present disclosure can be described as various interconnected or coupled functional blocks or functional diagrams. However, these functional blocks or functional diagrams can be equally integrated into a single logical device or operate according to non-precise boundaries.

[0108] Therefore, refer to Figure 1 The physiological optical signal credibility assessment method described may be implemented by a system including at least one computing device and at least one storage device storing instructions.

[0109] According to an exemplary embodiment of the present disclosure, at least one computing device is a computing device for executing a physiological optical signal credibility assessment method according to an exemplary embodiment of the present disclosure, and a computer executable instruction set is stored in the storage device. When the computer executable instruction set is executed by the at least one computing device, the execution reference Figure 1 A method for evaluating the credibility of physiological optical signals is described.

[0110] According to an exemplary embodiment of the present disclosure, a computer program product may also be provided, comprising instructions, which, when executed by at least one computing device, prompt the at least one computing device to perform the physiological optical signal credibility assessment method according to the present disclosure.

[0111] The above describes various exemplary embodiments of the present disclosure, and it should be understood that the above description is only exemplary and not exhaustive, and the present disclosure is not limited to the disclosed exemplary embodiments. Without departing from the scope and spirit of the present disclosure, many modifications and changes are obvious to those of ordinary skill in the art. Therefore, the scope of protection of the present disclosure should be based on the scope of the claims.

Claims

1. A method for evaluating the credibility of physiological optical signals, characterized in that: include: Acquire multiple physiological optical signal sequences of the same signal channel, wherein each physiological optical signal sequence corresponds to a wavelength and includes multiple physiological optical signals with corresponding wavelengths arranged in a time sequence of acquisition; performing at least one of correlation evaluation and quality evaluation on the plurality of physiological optical signal sequences; Based on the evaluation result of at least one of the correlation evaluation and the quality evaluation, obtaining the credibility information of the signal channel, The correlation evaluation includes: evaluating the correlation between any two of the multiple physiological optical signal sequences, wherein the credibility is positively correlated with the correlation. The quality assessment includes: assessing the signal-to-noise ratio quality of each physiological optical signal sequence in the plurality of physiological optical signal sequences, wherein the credibility is positively correlated with the signal-to-noise ratio quality.

2. The physiological optical signal credibility assessment method according to claim 1, characterized in that: The step of evaluating the correlation between any two of the plurality of physiological optical signal sequences comprises: Based on the multiple wavelengths corresponding to the multiple physiological optical signal sequences, two different wavelengths are combined into a wavelength pair to obtain multiple wavelength pairs, wherein each wavelength in the multiple wavelengths has a corresponding wavelength pair; For each wavelength pair, a correlation measure of the physiological optical signal sequences at two different wavelengths is calculated; Counting the correlation measures of the multiple wavelength pairs to obtain a correlation index of the signal channel; The correlation is determined according to the correlation indicator.

3. The physiological optical signal credibility assessment method according to claim 2, characterized in that: The step of combining two different wavelengths into a wavelength pair based on the multiple wavelengths corresponding to the multiple physiological optical signal sequences to obtain multiple wavelength pairs includes: Determine a wavelength from a plurality of wavelengths corresponding to the plurality of physiological optical signal sequences as a reference wavelength; The reference wavelength is paired with each wavelength of the plurality of wavelengths except the reference wavelength to obtain the plurality of wavelength pairs.

4. The physiological optical signal credibility assessment method according to claim 2, characterized in that: Determining the correlation according to the correlation indicator includes: When the correlation index is greater than the correlation threshold, the correlation is determined to be relevant; otherwise, the correlation is determined to be irrelevant.

5. The physiological optical signal credibility assessment method according to claim 1, characterized in that: The evaluating the signal-to-noise ratio quality of each physiological optical signal sequence in the plurality of physiological optical signal sequences comprises: Performing filtering processing on each of the multiple physiological optical signal sequences respectively to obtain multiple physiological optical signal sequences within a specified frequency range; Performing power spectral density calculation processing on each of the multiple physiological optical signal sequences within the specified frequency ranges to obtain a power spectral density of each of the multiple physiological optical signal sequences; The signal-to-noise ratio quality is determined according to a power spectral density of each physiological optical signal sequence in the plurality of physiological optical signal sequences.

6. The physiological optical signal credibility assessment method according to claim 5, characterized in that: The determining the signal-to-noise ratio quality according to the power spectral density of each physiological optical signal sequence in the plurality of physiological optical signal sequences comprises: When the peak value of the power spectrum density of each physiological optical signal sequence in the multiple physiological optical signal sequences is greater than the peak threshold, the signal-to-noise ratio quality is determined to be passed; otherwise, the signal-to-noise ratio quality is determined to be failed.

7. A physiological optical signal credibility assessment device, characterized in that: include: an acquisition unit, configured to acquire a plurality of physiological optical signal sequences of the same signal channel, wherein each physiological optical signal sequence corresponds to a wavelength and includes a plurality of physiological optical signals with corresponding wavelengths arranged in a time sequence of acquisition; an evaluation unit configured to perform at least one of a correlation evaluation and a quality evaluation on the plurality of physiological optical signal sequences; a determining unit configured to obtain the credibility information of the signal channel based on an evaluation result of at least one of the correlation evaluation and the quality evaluation, The correlation evaluation includes: evaluating the correlation between any two of the multiple physiological optical signal sequences, wherein the credibility is positively correlated with the correlation. The quality assessment includes: assessing the signal-to-noise ratio quality of each physiological optical signal sequence in the plurality of physiological optical signal sequences, wherein the credibility is positively correlated with the signal-to-noise ratio quality.

8. A computer-readable storage medium storing instructions, characterized in that: When the instructions are executed by at least one computing device, the at least one computing device is prompted to execute the physiological optical signal credibility assessment method according to any one of claims 1 to 6.

9. A system comprising at least one computing device and at least one storage device storing instructions, characterized in that: When the instructions are executed by the at least one computing device, the at least one computing device is prompted to perform the physiological optical signal credibility assessment method according to any one of claims 1 to 6.

10. A computer program product comprising instructions, characterized in that When the instructions are executed by at least one computing device, the at least one computing device is prompted to perform the physiological optical signal credibility assessment method according to any one of claims 1 to 6.

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