CN118058746A

CN118058746A - Signal acquisition system

Info

Publication number: CN118058746A
Application number: CN202211422147.0A
Authority: CN
Inventors: 周鑫; 黎美琪; 苏雷; 张宇翔; 刘嘉; 朱慧进; 宁溢轩; 廖风云; 齐心
Original assignee: Shenzhen Voxtech Co Ltd
Current assignee: Shenzhen Voxtech Co Ltd
Priority date: 2022-11-14
Filing date: 2022-11-14
Publication date: 2024-05-24

Abstract

An embodiment of the present specification provides a signal acquisition system, including a wearable body; a plurality of electrodes fixed to the wearable body and in contact with the user's skin, the plurality of electrodes including a first electrode group and a second electrode group, the first electrode group including two first electrodes arranged at intervals to collect a first physiological signal, and the second electrode group including two second electrodes arranged respectively close to the two first electrodes to collect a second physiological signal; and a processing circuit for eliminating motion artifacts in the first physiological signal according to the second physiological signal.

Description

Signal acquisition system

Technical Field

The present disclosure relates to the field of signal acquisition, and in particular, to a signal acquisition system.

Background

The signal acquisition system widely applied to the fields of physiological detection, disease diagnosis, experimental study and the like can acquire data related to the physical condition of a user by acquiring physiological signals. For example, the signal acquisition system may detect and utilize information from the cardiac signal to reflect the operational state of the human heart. However, when the signal acquisition system acquires physiological signals, the acquired physiological signals often contain motion artifacts due to interference signals generated by some movement or shaking and the like of a human body in the signal acquisition process, so that the quality of the physiological signals is poor, and the physical state of a user is difficult to accurately reflect. Therefore, it is desirable to provide a signal acquisition system that reduces the interference of motion artifacts and improves the quality of the acquired physiological signals.

Disclosure of Invention

One of the embodiments of the present specification provides a signal acquisition system, including: wearing a body; the electrodes are fixed on the wearing body and are in contact with the skin of a user, the electrodes comprise a first electrode group and a second electrode group, the first electrode group is used for collecting physiological signals, and the second electrode group is used for collecting detection signals; and a processing circuit for removing motion artifacts in the physiological signal from the detected signal.

In some embodiments, the first electrode set includes two first electrodes arranged at intervals, the second electrode set includes two second electrodes arranged adjacent to the two first electrodes, respectively, the physiological signal is a first physiological signal, the detection signal is a second physiological signal, and the processor is configured to eliminate motion artifacts in the first physiological signal according to the second physiological signal.

In some embodiments, the conductivity of the material of the two second electrodes is different.

In some embodiments, the protrusions of the two second electrodes relative to the user's skin are different in height in a direction perpendicular to the surface of the user's skin.

In some embodiments, the hardness of the material of the two second electrodes is different, or the degree of wrinkling of the material of the two second electrodes is different.

In some embodiments, the areas of the two second electrodes are different.

In some embodiments, the first electrode set includes two first electrodes arranged at intervals, and the second electrode set includes one second electrode arranged near one of the two first electrodes, wherein the second electrode and the first electrode near the second electrode are used for acquiring detection signals.

In some embodiments, the material of each second electrode is less conductive than the material of the corresponding first electrode.

In some embodiments, the protrusions of each second electrode relative to the wearing body are smaller than the protrusions of the corresponding first electrode relative to the wearing body in a direction perpendicular to the skin surface of the user.

In some embodiments, the second material of each second electrode is harder than the first material of the corresponding first electrode, or the second material of each second electrode is wrinkled to a greater extent than the first material of the corresponding first electrode.

In some embodiments, each second electrode has a smaller area in contact with the skin than the corresponding first electrode.

In some embodiments, the first electrode set includes two first electrodes arranged at intervals, the second electrode set includes two second electrodes arranged adjacent to the two first electrodes, respectively, and the detection signal is a detection signal reflecting contact impedance between the two first electrodes and the skin of the user.

In some embodiments, an excitation source is also included in electrical communication with the two second electrodes, the excitation source for providing an excitation signal.

In some embodiments, the frequency of the physiological signal is in the range of 20Hz-400 Hz and the frequency of the excitation signal is not less than 250Hz.

In some embodiments, the difference between the frequency of the excitation signal and any integer multiple of 50Hz is not less than 1Hz; or the difference between the frequency of the excitation signal and any integer multiple of 60Hz is not less than 1Hz.

In some embodiments, the frequency of the excitation signal is higher than the frequency range of the physiological signal.

In some embodiments, the detection signal and the physiological signal are acquired separately over different time periods.

In some embodiments, the minimum distance between the edge of each second electrode and the edge of the corresponding first electrode is less than 10cm.

In some embodiments, each of the second electrodes is connected to one of the first electrodes by a non-elastic connection, and a ratio of a distance difference between the movable distance of the second electrode and the movable distance of the corresponding first electrode on a surface parallel to the skin surface to the movable distance of the corresponding first electrode on a surface parallel to the skin surface is not more than 50%.

In some embodiments, the processing circuitry is to:

Differential processing is carried out on signals acquired by the two first electrodes to obtain physiological signals;

Differentially processing signals acquired by the two second electrodes to obtain detection signals; and

Motion artifacts in the physiological signal are eliminated from the detected signal.

In some embodiments, an inertial sensor is also included, the inertial sensor being disposed on a side of the first electrode set facing away from the skin of the user and configured to measure motion artifacts of the first electrode set.

One of the embodiments of the present disclosure also provides a signal acquisition system, including: wearing a body; a plurality of electrodes fixed to the wearing body and contacting the skin of the user, the plurality of electrodes including two electrodes arranged at intervals to collect physiological signals; an excitation source electrically connected to the two electrodes, the excitation source for providing an excitation signal to generate a detection signal reflecting the contact impedance between the two electrodes and the skin of the user; and a processing circuit for removing motion artifacts in the physiological signal from the detected signal.

Drawings

FIG. 1 is a block diagram of an exemplary signal acquisition system shown in accordance with some embodiments of the present description;

FIG. 2 is a schematic diagram of an exemplary signal acquisition system shown in accordance with some embodiments of the present description;

FIG. 3 is a schematic diagram of an exemplary signal acquisition system shown in accordance with some embodiments of the present description;

FIG. 4 is a schematic diagram of an exemplary signal acquisition system shown in accordance with some embodiments of the present description;

FIG. 5 is a schematic diagram of an exemplary signal acquisition system shown in accordance with further embodiments of the present description;

FIG. 6 is a block diagram of an exemplary signal acquisition system shown in accordance with some embodiments of the present description;

FIG. 7A is a schematic diagram showing the relationship of contact impedance and electromyographic signals, according to some embodiments of the present disclosure;

FIG. 7B is a schematic diagram showing the relationship of contact impedance and electromyographic signals as shown in some embodiments of the present disclosure; and

Fig. 8 is a block diagram of an exemplary signal acquisition system shown in accordance with some embodiments of the present description.

Detailed Description

In order to more clearly illustrate the technical solution of the embodiments of the present application, the drawings that are required to be used in the description of the embodiments will be briefly described below. It is apparent that the drawings in the following description are only some examples or embodiments of the present application, and it is apparent to those of ordinary skill in the art that the present application may be applied to other similar situations according to the drawings without inventive effort. Unless otherwise apparent from the context of the language or otherwise specified, like reference numerals in the figures refer to like structures or operations.

It will be appreciated that "system," "apparatus," "unit" and/or "module" as used herein is one method for distinguishing between different components, elements, parts, portions or assemblies at different levels. However, if other words can achieve the same purpose, the words may be replaced by other expressions.

As used in the specification and in the claims, the terms "a," "an," "the," and/or "the" are not specific to a singular, but may include a plurality, unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that the steps and elements are explicitly identified, and they do not constitute an exclusive list, as other steps or elements may be included in a method or apparatus.

The terms "first," "second," and the like in the description and in the claims, are not used for any order, quantity, or importance, but are used for distinguishing between different elements. Likewise, the terms "a" or "an" and the like do not denote a limitation of quantity, but rather denote the presence of at least one. Unless otherwise indicated, the terms "front," "rear," "lower," and/or "upper" and the like are merely for convenience of description and are not limited to one location or one spatial orientation. In general, the terms "comprises" and "comprising" merely indicate that the steps and elements are explicitly identified, and they do not constitute an exclusive list, as other steps or elements may be included in a method or apparatus.

The embodiments of the present specification describe a signal acquisition system. In some embodiments, a signal acquisition system may include a wearable body and a plurality of electrodes. The electrodes are fixed on the wearing body, and when the wearing body is worn on a user, the electrodes are contacted with the skin of the user so as to collect physiological signals of the user through the electrodes. In some embodiments, the plurality of electrodes may include a first electrode set including two first electrodes arranged at intervals to acquire the first physiological signal and a second electrode set including two second electrodes arranged adjacent to the two first electrodes, respectively, to acquire the second physiological signal. In some embodiments, the two sets of electrodes (e.g., the first electrode set and the second electrode set) may be configured to collect the first physiological signal and the second physiological signal differently. For example, the first physiological signal may include a real physiological signal and motion artifacts, the second physiological signal may include motion artifacts and a small amount of real physiological signals, or the second physiological signal may include only motion artifacts, where the motion artifacts are interference signals generated by the motion of the user (e.g., shaking of the head and/or limbs, etc.) during the signal acquisition process. The second electrode is arranged close to the first electrode, and the second electrode and the first electrode have motion consistency, so that physiological signals acquired by the second electrode group and the first electrode group have strong correlation. In some embodiments, the motion artifact in the first physiological signal may be considered to be substantially the same as the motion artifact in the second physiological signal, with a negligible amount of the real physiological signal in the second physiological signal. In some embodiments, the signal acquisition system may further include processing circuitry to cancel motion artifacts in the first physiological signal from the second physiological signal to obtain a true physiological signal in the first physiological signal. The signal acquisition system described in the embodiments of the present disclosure may possibly eliminate motion artifacts in the acquired physiological signal, so that the finally obtained physiological signal has less interference and higher quality.

Fig. 1 is a block diagram of an exemplary signal acquisition system 100 shown in accordance with some embodiments of the present description. As shown in fig. 1, the signal acquisition system 100 includes a wearable body 110, a first electrode set 12, a second electrode set 13, and a processing circuit 140. The first electrode group 12 may include two first electrodes 120 and the second electrode group 13 may include two second electrodes 130.

The wearing body 110 is used for wearing on a user. In some embodiments, the wearable body 110 may be a coat (e.g., a T-shirt, a waistcoat, a vest, an outer garment, etc.) that is worn on the upper body of the user. In some embodiments, the wearing body 110 may be a pants garment (e.g., pants, shorts, etc.), which is worn on the lower body of the user. In some embodiments, the wearing body 110 may also be a leg ring or a waistband, which is worn on the legs or waist of the user, respectively. In some embodiments, the wearable body 110 may also include smart bracelets, smart footwear, smart glasses, smart helmets, smart watches, smart backpacks, smart accessories, and the like, or any combination thereof.

Electrodes (e.g., first electrode 120 in first electrode set 12, second electrode 130 in second electrode set 13) may refer to circuit elements for contacting other objects to input or output a voltage (current). In some embodiments, electrodes (e.g., first electrode 120 in first electrode set 12, second electrode 130 in second electrode set 13) may be in contact with the skin for acquiring physiological signals of the user. The physiological signal is a signal that may reflect the physical state of the user, and in some embodiments, may include one or more of a respiratory signal, an electrocardiographic signal (ECG), an electromyographic signal, a blood pressure signal, an oximetry signal, a temperature signal, and the like. During the acquisition of physiological signals, the electrodes may be fixed to the wearing body 110 and remain in contact with the skin of the user. In some embodiments, the electrodes may be disposed on the wearing body 110 at various locations relative to the human body, such as the lower leg, thigh, waist, back, chest, shoulder, neck, etc.

Taking the electrocardiographic signal acquisition as an example, a plurality of electrodes for acquiring the electrocardiographic signal may be disposed at positions (for example, waist, back, chest, hand, etc. of a human body) of different distances from the heart of the user on the wearing body 110. For example, the two first electrodes 120 of the first electrode group 12 may be spaced apart in a lumbar region of the human body, and the two second electrodes 130 of the second electrode group 13 are disposed adjacent to the two first electrodes 120, respectively. In some embodiments, to improve the similarity of motion artifacts in the electrocardiographic signals acquired by the two first electrodes (or the second electrodes), the wearable body 110 may symmetrically attach the two first electrodes (or the second electrodes) to both sides of the median sagittal plane of the human body. One of the two first electrodes 120, acquires a first potential and the other first electrode 120 acquires a second potential, with a first potential difference between the first and second potentials (the first potential difference may be used to generate a parameter reflecting the first electrocardiograph signal). One of the two second electrodes 130 captures a third potential and the other second electrode 130 captures a fourth potential, with a second potential difference between the third and fourth potentials (the second potential difference may be used to reflect a parameter of the second electrocardiograph signal).

Also taking the collection of electromyographic signals as an example, a plurality of electrodes for collecting electromyographic signals may be provided at a position having a large muscle group (for example, the back, waist, leg, etc. of the human body) on the wearing body 110. For example, two first electrodes 120 of the first electrode group 12 may be disposed at a distance on one muscle, and two second electrodes 130 of the second electrode group 13 may be disposed adjacent to the two first electrodes 120, respectively. In some embodiments, two first electrodes 120 and two second electrodes 130 may be disposed sequentially along the length of the muscle fiber at the site. The different positions in the length direction of the muscle fiber have different potentials, one first electrode 120 of the two first electrodes 120 can acquire a first potential, the other first electrode 120 can acquire a second potential, and a first potential difference is arranged between the first potential and the second potential (the first potential difference can be used for generating parameters reflecting the first electromyographic signals). One of the two second electrodes 130 may acquire a third potential and the other second electrode 130 may acquire a fourth potential, with a second potential difference between the third and fourth potentials (the third potential difference may be used to generate a parameter reflecting the second electromyographic signal).

The arrangement positions of the first electrode 120 and the second electrode 130 are exemplarily described below with reference to fig. 2 and 3.

Fig. 2 is a schematic diagram of an exemplary signal acquisition system 100 shown in accordance with some embodiments of the present description. As shown in fig. 2, the signal acquisition system 100 includes a wearing body 110, and the wearing body 110 is a jacket. The two first electrodes 120 are disposed at intervals, and one second electrode 130 of the two second electrodes 130 is disposed near one first electrode 120 of the two first electrodes 120, respectively. As shown in fig. 2, two first electrodes 120 and two second electrodes 130 may be disposed at positions of the upper garment corresponding to the chest of the human body.

Fig. 3 is a schematic diagram of an exemplary signal acquisition system 100 shown in accordance with some embodiments of the present description. As shown in fig. 3, the wearing body 110 is a strap, which is put on the lower leg of the human body. In some embodiments, a first electrode 120 and a second electrode 130 disposed adjacent thereto may be disposed on one side of the ribbon along the length of the muscle fibers; the other first electrode 120 and the second electrode 130 disposed adjacent thereto may be disposed on the other side of the band along the length of the muscle fiber.

The processing circuit 140 may be used to process the signals. In some embodiments, the processing circuitry 140 may be provided separately from the wearable body 110, and a plurality of electrodes may be communicatively connected to the processing circuitry 140. In still other embodiments, the processing circuitry 140 may be secured to the wearable body 110. In some embodiments, the first electrode set 12 (two first electrodes 120) and the second electrode set 13 (two second electrodes 130) may each be electrically connected to the processing circuit 140, the processing circuit 140 receiving the first and second potentials from the two first electrodes 120 and the third and fourth potentials from the two second electrodes 130. The processing circuit 140 can differentially process the first potential and the second potential to obtain a first potential difference for characterizing a physiological signal (e.g., a first physiological signal). The processing circuit 140 may differentially process the third potential and the fourth potential to obtain a second potential difference for characterizing the detection signal (e.g., the second physiological signal). In some embodiments, the processing circuit 140 may differentially process the first physiological signal with the second physiological signal to eliminate motion artifacts in the first physiological signal. In some embodiments, the ratio of the real physiological signal and the motion artifact in the first physiological signal to the ratio of the real physiological signal and the motion artifact in the second physiological signal may be made different by a differential design between the plurality of electrodes (e.g., the first electrode 120 and the second electrode 130, and/or the two second electrodes 130) to eliminate the motion artifact in the first physiological signal from the differential first physiological signal and the differential second physiological signal. For more description of electrode differentiation designs, see fig. 4,5 and related description elsewhere in this specification.

In some embodiments, the signal acquisition system 100 may also include an inertial sensor 150. Inertial sensor 150 is used to measure motion artifacts of first electrode set 12. In some embodiments, inertial sensor 150 may be disposed on first electrode set 12. For example, an inertial sensor 150 may be provided at any one of the two first electrodes 120 (e.g., the side of the first electrode 120 facing away from the skin of the user), where the inertial sensor 150 and the first electrode 120 at which it is positioned may be considered to have a consistent motion state, so that the motion signal detected by the inertial sensor 150 may be indicative of the motion state of the first electrode 120 at which it is positioned, and the detected motion signal may be used to characterize motion artifacts of the first electrode set 12. As another example, inertial sensors 150 may be provided at each of the two first electrodes 120 (e.g., at a side of each first electrode 120 facing away from the skin of the user). At this time, the two inertial sensors 150 may respectively detect motion signals indicating the motion states of the first electrodes 120 where they are located. In some embodiments, the two motion signals detected by the two inertial sensors 150 may be processed (e.g., averaged, weighted averaged, etc.) to obtain a motion artifact for the first electrode set 12.

In some embodiments, inertial sensor 150 may be electrically connected to processing circuitry 140. In some embodiments, the signal acquisition system 100 may include a first electrode set 12, an inertial sensor 150 disposed on a side of the first electrode set facing away from the skin of the user, and a processing circuit 140. The first electrode set 12 includes two first electrodes 120 arranged at intervals to acquire physiological signals (i.e., first physiological signals); inertial sensor 150 is configured to measure a motion signal of the first electrode set 12 as a motion artifact of the first electrode set 12; the processing circuit 140 is configured to cancel motion artifacts in the physiological signals acquired by the first electrode set 12 based on the motion signals measured by the inertial sensor 150. Since the principle of measuring the motion signal by the inertial sensor 150 is different from the principle of measuring the motion artifact contained in the physiological signal acquired by the first electrode set 12, the processing circuit 140 may perform differential processing after preprocessing the motion signal and the physiological signal (for example, normalizing the motion signal and the physiological signal) to eliminate the motion artifact in the motion signal. For another example, the motion signal and the physiological signal are both subjected to principal component analysis by preprocessing the motion signal and the physiological signal, and then the principal component of the motion signal is removed from the physiological signal and reconstructed to eliminate motion artifacts in the motion signal. In some embodiments, the information acquisition system 100 may include a first electrode set 12, a second electrode set 13, an inertial sensor 150 disposed on a side of the first electrode set facing away from the skin of the user, and a processing circuit 140. The processing circuit 140 is configured to determine a confidence level of the second physiological signal for eliminating motion artifacts in the first physiological signal based on the motion signal measured by the inertial sensor 150. For example, a threshold may be preset in the processing circuit 140, if the difference between the motion signal measured by the inertial sensor 150 and the second physiological signal acquired by the second electrode set 13 is smaller than the preset threshold, the confidence of the second physiological signal is considered to be higher, and the processing circuit 140 may perform differential processing on the first physiological signal according to the second physiological signal to eliminate motion artifacts in the first physiological signal; if the difference between the motion signal and the second physiological signal exceeds the preset threshold, the confidence of the second physiological signal is considered to be low, and the processing circuit 140 may send an instruction to reacquire the second physiological signal to the second electrode set 13. For another example, the processing circuit 140 may perform differential processing (as described above, performing preprocessing and then performing differential processing) on the first physiological signal according to the motion signal measured by the inertial sensor 150, so as to eliminate motion artifacts in the first physiological signal.

It should be noted that the signal acquisition system 100 may include a plurality of first electrode groups 12 and a plurality of second electrode groups 13. The plurality of first electrode sets 12 and the plurality of second electrode sets 13 are respectively fixed on the wearing body 110 corresponding to different parts of the human body so as to collect physiological signals of different parts of the human body of the user. It should be further noted that the technical solution of using the inertial sensor 150 may be applied to other embodiments of the present disclosure, for example, the signal acquisition system 100 shown in fig. 4 and 5, the signal acquisition system 300 shown in fig. 6, and the signal acquisition system 400 shown in fig. 8.

To obtain a more accurate, higher quality physiological signal, the differential first physiological signal and the second physiological signal may be obtained by a differential design between the plurality of electrodes (e.g., a differential design between the first electrode 120 and the second electrode 130 or a differential design between the two second electrodes 130). The differentiated design of the electrodes will be exemplarily described below with reference to fig. 4-5. Fig. 4 is a schematic diagram of the structure of an exemplary signal acquisition system 100 shown in accordance with some embodiments of the present description. Fig. 5 is a schematic diagram of an exemplary signal acquisition system 100 shown in accordance with further embodiments of the present description. As shown in fig. 4 and 5, a plurality of electrodes may be fixed on a side of the wearing body 110 close to the skin of the user and can be in contact with the skin. On the wearing body 110, two first electrodes 120 may be disposed at a distance, and two second electrodes 130 may be disposed near the first electrodes 120, respectively. In some embodiments, two first electrodes 120 and two second electrodes 130 may be disposed side by side, and two second electrodes 130 may be located on opposite sides of the two first electrodes 120. In some embodiments, two second electrodes 130 may be located between two first electrodes 120. In other embodiments, one of the second electrodes 130 may be located between two of the first electrodes 120, and the other second electrode 130 may be located on a side of the first electrode 120 adjacent thereto that is remote from the other first electrode 120. It should be noted that the two first electrodes 120 and/or the two second electrodes 130 are not limited to being arranged side by side as shown in fig. 4 and 5, but may be arranged in other manners. For example, the two first electrodes 120 may be separately disposed on the surface parallel to the skin surface in any of a plurality of spaced-apart manners, and the second electrode 130 disposed adjacent to each of the first electrodes 120 may be disposed at any position around the first electrodes 120 with a certain distance, which is not limited in this specification.

In some embodiments, the distance between the second electrode 130 and the corresponding first electrode 120 refers to the minimum distance between the edge of the second electrode 130 and the edge of the corresponding first electrode 120. As shown in fig. 4 and 5, the distance between the second electrode 130 and the corresponding first electrode 120 may refer to the dimension a, i.e., the minimum distance between the second electrode 130 and the edges of the first electrode 120 adjacent thereto that are adjacent to each other. To ensure that the movement of the second electrode set 13 is consistent with the movement of the first electrode set 12, the certain distance may be less than 10cm in some embodiments. For example, the certain distance may be less than 8cm. As another example, the certain distance may be less than 6cm. As used herein, "corresponding" refers to two closely disposed first and second electrodes 120, 130. That is, if a first electrode 120 and a second electrode 130 are disposed close to each other, the first electrode 120 may be referred to as a first electrode corresponding to the second electrode 130, or the second electrode 130 may be referred to as a second electrode corresponding to the first electrode 120.

In some embodiments, to ensure that the movement of the second electrode set 13 and the first electrode set 12 is as consistent as possible, the second electrode 130 and the corresponding first electrode 120 may be physically connected. The physical connection described in the specification means connection in a physical sense through a structure, a material or a composite structural material. The physical connection is an insulating connection in order to avoid the influence of electrical signals between the first electrode 120 and the second electrode 130. In some embodiments, the connection between the second electrode 130 and the corresponding first electrode 120 may be achieved through an insulating structure (e.g., a silicone layer). Any position of the second electrode 130 (e.g., a side, or a localized area on a surface, etc.) may be physically connected to any position of the first electrode 120 (e.g., a side, or a localized area on a surface, etc.). In some embodiments, to enhance the motion consistency of the second electrode 130 with the corresponding first electrode 120, the second electrode 130 may be non-elastically connected (or rigidly connected) with the corresponding first electrode 120. In some embodiments, the ratio of the distance difference of each second electrode 130 to the movable distance of the corresponding first electrode 120 on a surface parallel to the skin surface may be no more than 50%. For example, when the signal acquisition system 100 is worn by a user, the first electrode group 12 and the second electrode group 13 may move on the skin surface, and when moving, the ratio of the distance difference of the movable distance of each second electrode 130 from the corresponding first electrode 120 on the surface parallel to the skin surface to the movable distance of the corresponding first electrode 120 on the surface parallel to the skin surface may be not more than 45%. For another example, the ratio of the distance difference of each of the second electrodes 130 to the movable distance of the corresponding first electrode 120 on the surface parallel to the skin surface may be not more than 40%.

In order to reduce the interference of motion artifacts and improve the quality of the finally obtained physiological signal, the difference between the first physiological signal and the second physiological signal can be improved by the differential design of the first electrode 120 and the second electrode 130.

In some embodiments, the material of each second electrode 130 is less conductive than the material of the first electrode 120 to which it corresponds (e.g., is physically connected). As such, the ratio of the actual physiological signal in the first physiological signal acquired by the first electrode set 12 is greater than the ratio of the actual physiological signal in the second physiological signal acquired by the second electrode set 13. In some embodiments, when the conductivity of the material of the second electrode 130 is weaker than the conductivity of the material of the first electrode 120 corresponding thereto to some extent (e.g., the impedance of the material of the second electrode 130 differs from the impedance of the material of the first electrode 120 corresponding thereto to some extent), the actual physiological signal in the second physiological signal acquired by the second electrode set 13 may be negligibly small, and thus the second physiological signal may be considered to contain only motion artifacts. For example, at 50Hz for example, the impedance of the first electrode 120 varies by more than 1 mohm from the impedance of the material of the first electrode 120 to the impedance of the material of the second electrode 130, and the component of the motion artifact signal in the second physiological signal collected by the second electrode set 13 is significantly increased; when the impedance of the material of the first electrode 120 differs from the impedance of the material of the second electrode 130 by more than 100 mohms, the primary motion artifact is collected in the second physiological signal. Meanwhile, because the movements of the first electrode set 12 and the second electrode set 13 have consistency, the movement artifact in the first physiological signal can be eliminated according to the second physiological signal, so that the interference of the movement artifact in the first physiological signal is reduced, and a high-quality physiological signal is obtained. In some embodiments, the electrode may be an electrode composed of a single material, such as a metal fabric electrode, a conductive silicon electrode, a hydrogel electrode, a metal electrode, or the like. For example, the material of each first electrode 120 may be a metal fabric, and the material of the corresponding second electrode 130 may be conductive silicon, where the metal fabric has a smaller electrode resistivity and a higher conductivity. In some embodiments, the difference in electrode materials affects not only the impedance of the electrode itself, but also the contact impedance between the electrode and the skin. For example, the material of each first electrode 120 may be hydrogel, and the material of the corresponding second electrode 130 may be conductive silicon, with the hydrogel being more skin-friendly and moist than the conductive silicon, so that the contact resistance of the first electrode 120 is smaller and the conductivity is stronger with respect to the corresponding second electrode 130. In some embodiments, the difference in electrode materials may also affect the potential strength of the stratum corneum. For example, silver chloride materials have a smaller absolute value of half cell potential, and a smaller stratum corneum potential than silver materials, and under the same other conditions, the effect of MA is small. In some embodiments, the differentiation of the first electrode 120 and the second electrode 130 may be achieved by different thicknesses of the same material. For example, since the thickness of the metal fabric electrode is within a certain range, the larger the thickness, the smaller the impedance and the contact impedance with the skin, the better the conductivity. In some embodiments, the material of each first electrode 120 and the material of the corresponding second electrode 130 may be metal fabrics, but the thickness of the material of the first electrode 120 in the direction perpendicular to the skin (see the direction a shown in fig. 4 and 5) is greater than the thickness of the material of the corresponding second electrode 130 in the direction a. For another example, since the greater the thickness of the conductive silicon electrode, the smaller its resistance and the better its conductivity, in some embodiments, the material of the first electrode 120 and the material of the second electrode 130 corresponding thereto may both be conductive silicon, but the thickness of the material of the first electrode 120 is greater than the thickness of the material of the second electrode 130 corresponding thereto. In some embodiments, the material of the first electrode 120 and/or the material of the second electrode 130 corresponding thereto may be a combination (e.g., laminated, bonded, etc.) of different materials. For example, the material of the first electrode 120 and the material of the second electrode 130 corresponding thereto are both composed of a metal fabric and a conductive silicon material, the thickness of the metal fabric in the material of the first electrode 120 is smaller than the thickness of the metal fabric in the material of the second electrode 130 corresponding thereto, and the thickness of the conductive silicon material in the material of the first electrode 120 is larger than the thickness of the conductive silicon material in the material of the second electrode 130 corresponding thereto.

In some embodiments, the electrode may be fixed on the wearing body 110 by means of gluing, fastening, velcro, stitching, pressing, etc., and there may be protrusions of the electrode with respect to the direction of the wearing body 110 towards the skin surface. In some embodiments, the height of each second electrode 130 with respect to the wearing body 110 may be smaller than the height of the corresponding first electrode 120 with respect to the wearing body 110 in a direction perpendicular to the skin surface of the user. "bulge" of the electrode in this specification means a portion of the electrode beyond the skin-approaching surface 111 of the wearing body 110; the height of the protrusions means the height of the electrode above the portion of the wearing body 110 near the surface 111 of the skin in a direction perpendicular to the surface of the skin of the user. As shown in fig. 4, each of the first electrodes 120 has a height c with respect to the protrusions of the wearing body 110 in a direction perpendicular to the skin surface (i.e., direction a); the corresponding second electrode 130 has a height b in a direction perpendicular to the skin surface (i.e., direction a) with respect to the protrusion of the wearing body 110. In order to make the pressure between the second electrode 130 and the skin smaller than the pressure between the corresponding first electrode 120 and the skin, the fitting degree of the second electrode 130 and the skin is made worse relative to the first electrode 120, and then the proportion of the actual physiological signals in the second physiological signals collected by the second electrode group 13 is made smaller, as shown in fig. 4, the height b of each second electrode 130 relative to the protrusion of the wearing body 110 along the direction perpendicular to the skin surface (i.e. the direction a) may be smaller than the height c of the corresponding first electrode 120 relative to the protrusion of the wearing body 110 along the direction perpendicular to the skin surface (i.e. the direction a). Thus, the first electrical signal collected by the first electrode set 12 is different from the second electrical signal collected by the second electrode set 13. In some embodiments, when the ratio of the difference between the height b of the protrusion of the second electrode 130 and the height c of the protrusion of the corresponding first electrode 120 to the height c of the corresponding first electrode 120 is greater than a certain height threshold (e.g., 5%), there is a significant difference between the first electrical signal acquired by the first electrode set 12 and the second electrical signal acquired by the second electrode set 13, and thus the second physiological signal may be considered to include only motion artifacts. Meanwhile, because the movements of the first electrode set 12 and the second electrode set 13 have consistency, the second physiological signal can be utilized to perform differential processing on the first physiological signal so as to eliminate movement artifacts in the first physiological signal, reduce the interference of the movement artifacts in the first physiological signal and obtain a high-quality physiological signal. In some embodiments, to generate the differential first physiological signal and the second physiological signal, the height of the protrusion of each first electrode 120 may be in the range of 1mm-10cm, and the height of the protrusion of the corresponding second electrode 130 may be in the range of 0mm-5 mm.

In some embodiments, to generate the differential first physiological signal and the second physiological signal, the material of each second electrode 130 may be different from the material of the corresponding first electrode 120. For example, the material of each second electrode 130 may be harder than the material of the corresponding first electrode 120, such that the corresponding first electrode 120 is more conformable to the skin of the user than the second electrode 130, and therefore the ratio of the actual physiological signal in the second physiological signal is less relative to the first physiological signal (i.e., the ratio of motion artifacts in the second physiological signal is greater relative to the first physiological signal). In some embodiments, the material of each second electrode 130 may be wrinkled more than the material of its corresponding first electrode 120, such that the corresponding first electrode 120 is more conformable to the skin of the user than the second electrode 130, and therefore the ratio of the actual physiological signal in the second physiological signal is less relative to the first physiological signal (i.e., the ratio of motion artifacts in the second physiological signal is greater relative to the first physiological signal). It should be understood that the hardness or degree of wrinkling of the material is a comparison of measurements made under the same measurement method or the same measurement standard.

In some embodiments, the differential first physiological signal and the second physiological signal may be generated by a difference in contact impedance between the first electrode set 12 and the second electrode set 13 and the skin. In some embodiments, the differential contact impedance between the first electrode set 12 and the second electrode set 13 may be created by the difference in the area of each first electrode 120 and its corresponding second electrode 130 in contact with the skin. For example, the first electrode 120-skin contact surface (e.g., the B-surface as shown in fig. 4) may have a first area, and the corresponding second electrode 130-skin contact surface (e.g., the C-surface as shown in fig. 4) may have a second area, and the second area of each second electrode 130 may be smaller than the first area of the corresponding first electrode 120, such that the contact impedance between the first electrode 120 and the skin is smaller than the contact impedance between the corresponding second electrode 130 and the skin. As such, the real physiological signal of the first physiological signal acquired by the first electrode set 12 is more than the second physiological signal acquired by the second electrode set 13, and at the same time, the motion artifact of the second physiological signal is more than the first physiological signal. In some embodiments, the B-side of the first electrode 120 or the C-side of the second electrode 130 may be rectangular or rounded rectangular. In some embodiments, to make the contact impedance between the first electrode set 12 and the second electrode set 13 and the skin different, thereby generating the differential first physiological signal and the second physiological signal, the area of the contact surface (e.g., the B surface as shown in fig. 4) of the first electrode 120 and the skin may be in the range of 1cm ²-100 cm²; the area of the second electrode 130 in contact with the skin (e.g., the C-plane as shown in fig. 4) may be in the range of 0.5cm ²-50 cm². In some embodiments, the B-surface of the first electrode 120 or the C-surface of the second electrode 130 may be circular, triangular, hexagonal, or other regular or irregular shapes, and in practical applications, the shape of the B-surface or the C-surface may depend on the shape of the portion where the physiological signal is to be acquired. In some embodiments, a specific pattern of structures or folds may be disposed on the C-face of each second electrode 130, so as to reduce the adhesion between the second electrode 130 and the skin, and reduce the adhesion area between the second electrode 130 and the skin, so as to distinguish the first electrode 120 from the second electrode.

It should be understood that the signal acquisition system 100 shown in fig. 1-3, including four electrodes, is merely an example and is not intended to limit the number of electrodes in the signal acquisition system 100. The number of electrodes in the signal acquisition system 100 may be any number that can acquire differential motion signals and physiological signals, and is not limited herein. For example, the first electrode set 12 may include two first electrodes 120, and the second electrode set 13 may include only one second electrode 130 (i.e., the signal acquisition system 100 includes 3 electrodes). The two first electrodes 120 are used for acquiring a first physiological signal, and the second electrode 130 may be disposed near one of the first electrodes 120 and form an electrode pair with the first electrode 120 for acquiring a second physiological signal. It should be understood that, when the second electrode set 13 may include only one second electrode 130, parameters such as a material, conductivity, protrusion, hardness, wrinkle degree, and skin contact area of the second electrode 130 and the first electrode 120 corresponding thereto in the second electrode set may be the same as corresponding parameters of each second electrode 130 and the first electrode 120 corresponding thereto when the second electrode set 13 may include two second electrodes 130, which are not described herein. For another example, the signal acquisition system 100 may further include a reference electrode for acquiring a reference signal based on the above 3 electrodes. For another example, in the signal acquisition system 100 comprising four electrodes as shown in fig. 1-3, two first electrodes 120 are used to acquire a first physiological signal; the two second electrodes 130 may respectively form an electrode pair with the two first electrodes 120 to obtain a second physiological signal and a third physiological signal; the two second electrodes 130 may acquire a fourth physiological signal. In this manner, the signal acquisition system 100 including four electrodes can acquire four sets of differentiated electrical signals. It should be understood that the description of the first electrode set comprising two first electrodes 120 in this specification is only an example, and the first electrode set may comprise more than two first electrodes 120, correspondingly, in some embodiments, the second electrode set may comprise the same number of second electrodes 130 as the first electrodes 120. For example, the first electrode set includes three first electrodes 120 for acquiring physiological signals; the second electrode group includes three second electrodes 130 for collecting detection signals. In some embodiments, the first electrode set may include more than two numbers of first electrodes 120, and the second electrode set may include at least one second electrode 130. For example, the first electrode set may include three first electrodes 120 for acquiring physiological signals; the second electrode set may include one second electrode 130 for being disposed close to one of the first electrodes 120 to collect the detection signal.

In some embodiments, to facilitate the production of multiple electrodes in the signal acquisition system 100, two second electrodes 130 in the second electrode set 13 may be identical. For example, as shown in fig. 4, each of the second electrodes 130 may have the same conductivity, protrusion height, hardness, degree of wrinkles, contact area with skin, and the like. In some embodiments, to reduce the interference of motion artifacts and improve the quality of the physiological signal, a differential design may be implemented for the two second electrodes 130 of the second electrode set 13. When the two second electrodes 130 are different (e.g., one or any combination of conductivity, bump height, stiffness, degree of wrinkling, contact area with skin, etc.), the second electrode set 13 captures a second physiological signal having a ratio of motion artifacts that is greater than the second physiological signal captured by the same two second electrodes 130. Thus, the differential first physiological signal and the differential second physiological signal can be obtained through the differential design of the two second electrodes 130 in the second electrode group 13, so that when the motion artifact in the first physiological signal is eliminated by using the second physiological signal, the interference of the motion artifact is reduced.

In some embodiments, the differentiation between two second electrodes 130 may be similar to the differentiation design described above between a first electrode 120 and its corresponding second electrode 130. In some embodiments, the conductivity of the material of the two second electrodes 130 may be different. For example, the two second electrodes 130 may be conductive silicon electrodes having different thicknesses. For another example, the materials of the two second electrodes 130 may be conductive silicon electrodes and metal fabric electrodes, respectively. In some embodiments, the heights of the protrusions of the two second electrodes 130 relative to the wearing body 110 in the a direction (see heights d and e shown in fig. 5) may be different so that the fit of the two second electrodes 130 relative to the skin of the user is different. In some embodiments, the hardness of the material of the two second electrodes 130 may be different such that the fit of the two second electrodes 130 with respect to the user's skin is different. In some embodiments, the degree of wrinkling of the material of the two second electrodes 130 may be different such that the fit of the two second electrodes 130 with respect to the user's skin is different. In some embodiments, the areas of contact of the two second electrodes 130 with the skin (see E-plane and D-plane shown in fig. 5) may be different, so that the contact resistance between the two second electrodes 130 and the skin is different.

In some embodiments, as shown in fig. 4 and 5, the signal acquisition system 100 may also include an inertial sensor 150. The inertial sensor 150 is disposed on a side of the first electrode 120 facing away from the skin of the user such that the first electrode 120 has a consistent state of motion with the inertial sensor 150. It should be understood that fig. 4 and 5 are only two embodiments of the signal acquisition system 100 and are not intended to limit the structure of the signal acquisition system 100. For example, the signal acquisition system 100 may include a first electrode set 12, an inertial sensor 150 disposed on a side of the first electrode set 12 facing away from the skin of the user, and processing circuitry 140 (i.e., not including the second electrode set 13). As another example, as shown in fig. 4 or 5, the information acquisition system 100 may include a first electrode set 12, a second electrode set 13, an inertial sensor 150 disposed on a side of the first electrode set facing away from the skin of the user, and a processing circuit 140. For a description of inertial sensor 150, reference may be made to the associated description of FIG. 1. As another example, the signal acquisition system 100 may include the first electrode set 12, the second electrode set 13, and the processing circuitry 140 (i.e., not include the inertial sensor 150).

Fig. 6 is a block diagram of an exemplary signal acquisition system 300, shown in accordance with some embodiments of the present description. As shown in fig. 6, the signal acquisition system 300 may include a wearable body 310, a first electrode set 32, a second electrode set 33, and a processing circuit 340. The first electrode set 12 may include two first electrodes 320. The second electrode group 13 may include two second electrodes 330. The function and structural distribution of the wearing body 310 and the first electrode 320 shown in fig. 6 may be similar to those of the wearing body 110 and the first electrode 120 described in fig. 1 to 5, respectively, and will not be repeated here. The signal acquisition system 300 of fig. 6 differs from the signal acquisition system 100 described in fig. 1-5 in the functional and structural distribution of the second electrode 330. For example, the second electrode 330 is configured to collect a detection signal reflecting the contact impedance between the two first electrodes 320 and the skin of the user, and the processing circuit 340 is configured to eliminate motion artifacts in the physiological signal according to the detection signal, accordingly (for example, the detection signal and the physiological signal may be connected to a circuit, processed in an analog circuit, processed in a digital circuit, or processed in an algorithm). In some embodiments, the second electrodes 330 are used to collect detection signals reflecting the contact impedance between the two second electrodes 330 and the user's skin. To ensure motion consistency between the first electrodes 320 and the second electrodes 330, in some embodiments, the edge of each second electrode 330 may be positioned to be less than 10cm from the edge of the corresponding first electrode 320. In some embodiments, each of the second electrodes 330 may be further arranged to be connected to one of the first electrodes 320 by inelastic connection, and a ratio of a distance difference between the second electrode 330 and a movable distance of the corresponding first electrode 320 on a surface parallel to the skin surface to a movable distance of the corresponding first electrode 320 on a surface parallel to the skin surface is not more than 50%. For another example, in order to make the contact resistances between the two first electrodes 320 and the two second electrodes 330 as uniform as possible with the skin, so that the contact resistance of the second electrodes 330 may indirectly reflect the contact resistance of the first electrodes 320, each of the second electrodes 330 may be identical to the corresponding first electrode 320. For example, the conductivity of the material of each second electrode 330 and the material of the corresponding first electrode 320 may be the same. For another example, the protrusions of each of the second electrodes 330 with respect to the wearing body 310 may be the same as the protrusions of the corresponding first electrode 320 in a direction perpendicular to the skin of the user. As another example, the material of each second electrode 330 may have the same hardness and/or degree of wrinkling as the corresponding first electrode 320. For another example, the contact area of each of the second electrodes 330 with the skin may be the same as the contact area of the corresponding first electrode 320 with the skin. In this way, the motion consistency between the first electrode 320 and the second electrode 330 and the contact impedance with the skin are consistent as much as possible, and the detection signals of the contact impedance between the two second electrodes 330 and the skin of the user acquired by the two second electrodes 330 can be used to reflect the detection signals of the contact impedance between the two first electrodes 320 and the skin of the user. In some embodiments, the processing circuit 340 may process the signals acquired by the two first electrodes 320 differentially to obtain a physiological signal, process the signals acquired by the two second electrodes 330 differentially to obtain a detection signal, and eliminate motion artifacts in the physiological signal according to the detection signal.

In some embodiments, the signal acquisition system 300 further includes an excitation source 370 electrically connected to the two second electrodes 330. The excitation source 370 may be used to provide an excitation signal to generate a detection signal reflecting the contact impedance between the first electrode set 32 and the human body. In some embodiments, the excitation source 370 may be an ac excitation source, a dc excitation source, or a combination thereof. By way of example only, the excitation signal may be understood as forming a closed loop circuit after flowing through the human body via the second electrode 330, at which time the detection signal may correspond to a partial pressure of the contact impedance between the second electrode set 33 and the human body in the closed loop circuit. FIG. 7A is a schematic diagram showing the relationship of contact impedance and electromyographic signals, according to some embodiments of the present disclosure; fig. 7B is a schematic diagram showing a fluctuation relationship between contact impedance and electromyographic signals, in some embodiments of the present description. As shown in fig. 7A and 7B, the value of the contact impedance may fluctuate with movement at the same sampling point, regardless of whether the value of the contact impedance is large or small (e.g., the value of the contact impedance may increase with an increase in the electromyographic signal and also decrease with a decrease in the electromyographic signal). Thus, motion artifacts may be obtained from the contact impedance and may be removed from the physiological signal acquired by the first electrode set 32 using the obtained motion artifacts (e.g., motion artifacts characterized by a detection signal acquired by the second electrode set 33 reflecting the contact impedance between the first electrode set 32 and the skin of the user). For example, the contact impedance may be frequency analyzed to obtain a dominant frequency of the motion artifact, and the contact impedance may be amplitude analyzed (e.g., fluctuation/average nearby, etc.) to obtain intensity information of the motion artifact.

The excitation source 370 may be a circuit element that provides electrical energy. In some embodiments, the excitation source 370 may provide an excitation signal at a first frequency to generate a detection signal reflecting the contact impedance between the second electrode 330 and the human body. In some embodiments, excitation source 370 may be a current source or a voltage source. Meanwhile, the intensity of the excitation source 370 needs to be set by considering the safety voltage or the safety current of the human body, so as to ensure the safety of the human body, and the intensity of the excitation source 370 is not too high. In some embodiments, the current intensity of the excitation source 370 may be less than 1mA. Further, in some embodiments, the current intensity of the excitation source 370 may be less than 100 μA. Still further, in some embodiments, the current intensity of the excitation source 370 may be 10 μA.

In some embodiments, the number of excitation sources 370 may be one, and may be connected to the plurality of second electrodes 330 through a plurality of branches, to provide excitation signals to the plurality of second electrodes 330, where each branch may be provided with one second electrode 330. In some embodiments, the excitation source 370 may be multiple, and each excitation source 370 may be respectively connected to one or more second electrodes 330 to provide an excitation signal to each second electrode 330.

In some embodiments, the excitation source 370 may simultaneously generate a plurality of excitation signals having different frequencies, and may provide the plurality of second electrodes 330 with excitation signals having the same frequency or different frequencies, thereby generating detection signals of different frequencies. For example, the excitation source 370 may provide excitation signals of different frequencies to the plurality of second electrodes 330 to collect different detection signals. The plurality of second electrodes 330 may have a larger distance (for example, greater than or equal to 5 cm), so that the closed loop through which the excitation signal flows may be through different human tissues, and thus, the detection signals with different frequencies corresponding to the plurality of second electrodes 330 may be used to reflect body composition information of the human body, such as body fat rate, bone density, body fluid content, and the like. Specifically, the excitation source 370 may provide a second excitation signal at a second frequency different from the first frequency to generate a second detection signal. The second detection signal may reflect impedance information on a closed loop formed between the second electrode 330 and the human body at the second frequency, including contact impedance of the second electrode 330 with the human body and impedance of human tissue on the closed loop. In some embodiments, body composition information of a human body may be determined using a first detection signal generated by a first excitation signal (e.g., an excitation signal having a first frequency) and a second detection signal generated by a second excitation signal.

In some embodiments, the excitation signal may be a voltage signal or a current signal. In some embodiments, the excitation signal may be an alternating current signal having a first frequency such that the generated detection signal also has the first frequency. The first frequency may be set in a frequency range that is less subject to external interference (e.g., power frequency interference) and less interference with physiological signals.

In some embodiments, the frequency of the excitation signal may be set according to the frequency range of the physiological signal. In some embodiments, the frequency of the excitation signal may be higher than the frequency range of the physiological signal, so as to avoid most frequency bands where the physiological signal is located, and reduce mutual interference between the physiological signal and the excitation signal. In some embodiments, the excitation frequency may be not less than 850Hz. For example, the excitation frequency may be not less than 400Hz. If the intensity of the excitation signal is high or the contact impedance corresponding to the electrode of the site to be measured can be divided to a sufficient voltage, the interference of the physiological signal to the excitation signal is low, and the excitation signal (for example, the excitation signal with the frequency of not less than 400 Hz) can tolerate a small part of the physiological signal (for example, the physiological signal with the frequency of 400Hz to 850 Hz). In some embodiments, because the frequency of the physiological signal (e.g., the electromyographic signal) is primarily centered at 20Hz to 400Hz and there are stronger motion artifacts in the low frequency band, the frequency of the excitation signal provided by the excitation source 370 may be greater than 250Hz in order to avoid being affected by the electromyographic signal and motion artifacts. In some embodiments, because interference from power frequency (e.g., 50Hz or 60Hz ac power and harmonics thereof) noise is also present in the signal acquisition system 300, the frequency of the excitation source may also avoid the frequency range in which the power frequency noise is located. In some embodiments, the difference between the frequency of the excitation signal provided by excitation source 370 and any integer multiple of 50Hz or 60Hz may be no less than 1Hz, or the difference between the frequency of the excitation signal provided by excitation source 370 and any integer multiple of 50Hz or 60Hz may be no less than 2%. In some embodiments, the excitation signal provided by excitation source 370 may have a frequency above 400Hz, such as 460Hz, 640Hz, 830Hz, and the like. In some embodiments, the setting of the frequency of the excitation signal provided by excitation source 370 may also need to be considered in connection with the sampling frequency of processing circuit 340. Specifically, to collect the detection signal, the sampling frequency may be at least 2 times and more the frequency of the excitation signal provided by the excitation source 370. To reduce errors, in some embodiments, the sampling frequency may be 4 times and more than the frequency of the excitation signal provided by excitation source 370. It should be noted that, since the number of channels to be sampled may be large, it is difficult for most of the processing circuits 340 to support the extremely high sampling frequency of the multiple channels, so the sampling frequency of the processing circuits 340 and the frequency of the excitation signal provided by the excitation source 370 are not too high. Based on this, in some embodiments, the frequency of the excitation signal provided by excitation source 370 may be in the range of 250 Hz-2000 Hz.

In some embodiments, the signal acquisition system 300 may acquire physiological signals and detection signals, respectively, over different time periods. For example, the signal acquisition system 300 may acquire physiological signals over a first period of time. The signal acquisition system 300 may acquire the detection signal for a second period of time. For example, the signal acquisition system 300 may include a switching circuit that may be used to control the conductive state of the first electrode set and the processing circuit 340, and may also be used to control the conductive state of the second electrode set and the excitation source 370, such that only the first electrode set and the processing circuit 340 remain electrically conductive at the same time, or only the second electrode set and the excitation source 370 remain electrically conductive. Therefore, the detection signals and the physiological signals are acquired and processed in a time-sharing way, so that the processing pressure of equipment can be reduced while the mutual interference of the signals is avoided, and the computing resources are saved. In some embodiments, the signal acquisition system 300 may acquire physiological signals and detection signals simultaneously and transmit the signals to different processing circuits through different transmission channels to avoid signal interference.

Fig. 8 is a block diagram of an exemplary signal acquisition system 400 shown in accordance with some embodiments of the present description. As shown in fig. 8, the signal acquisition system 400 may include a wearable body 410, two electrodes 420, a processing circuit 440, and an ac excitation source 470. The wearable body 410, the processing circuit 440, and the ac excitation source 470 shown in fig. 8 are similar to the wearable body 310 and the processing circuit 340 shown in fig. 6, and are not described here again. The signal acquisition system 400 of fig. 8 differs from the signal acquisition system 300 of fig. 6 in that the signal acquisition system 400 comprises only one set of electrodes (two electrodes 420), both electrodes 420 can acquire physiological signals and detect signals reflecting the contact impedance between the two electrodes 420 and the skin; the excitation source in the signal acquisition system 400 is an ac excitation source 470, and the excitation source in the signal acquisition system 300 may be an ac excitation source, a dc excitation source, or a combination of both. In some embodiments, two electrodes 420 for collecting physiological signals and detecting signals may be fixed to the wearing body 410 and in contact with the skin of the user.

In some embodiments, an ac excitation source 470 is electrically connected to both electrodes 420. The ac excitation source 470 is used to provide an excitation signal to generate a detection signal reflecting the contact impedance between the two electrodes 420 and the human body. By way of example only, the excitation signal may be understood as forming a closed loop after flowing through the human body via the electrode 420, at which time the detection signal may correspond to the partial pressure of the contact impedance between the electrode 420 and the human body in the closed loop. In some embodiments, as shown in fig. 7A and 7B, the value of the contact impedance may fluctuate with motion (e.g., the value of the contact impedance may increase with increasing electromyographic signals and also decrease with decreasing electromyographic signals). Thus, motion artifacts may be obtained from the contact impedance, i.e. the obtained motion artifacts (e.g. motion artifacts characterized by detection signals acquired by the two electrodes 420 reflecting the contact impedance between the two electrodes 420 and the skin of the user) may be used to cancel motion artifacts in the physiological signals acquired by the two electrodes 420. It should be appreciated that the frequency of the physiological signals, the frequency of the excitation signals, etc. acquired by the signal acquisition system 400 shown in fig. 8 may be similar to the signal acquisition system 300 shown in fig. 6 and are not described in detail herein. Since the physiological signal and the detection signal are collected by the same set of electrodes, the signal collection system 400 can collect the physiological signal and the detection signal, respectively, in different time periods. For example, the signal acquisition system 400 can acquire physiological signals over a first period of time. The signal acquisition system 400 may acquire the detection signal for a second period of time. For example, the signal acquisition system 400 may include a switching circuit that may be used to control the conductive state of the two electrodes 420 and the processing circuit 440, and may also be used to control the conductive state of the two electrodes 420 and the excitation source 370, such that the two electrodes 420 and the processing circuit 440 are kept in electrical conduction at the same time, or the two electrodes 420 and the ac excitation source 470 are kept in electrical conduction. Therefore, the detection signals and the physiological signals are acquired and processed in a time-sharing way, so that the processing pressure of equipment can be reduced while the mutual interference of the signals is avoided, and the computing resources are saved.

It should be noted that the above description of the signal acquisition system is merely an exemplary description and is not intended to limit the present disclosure to the scope of the illustrated embodiments. Wherein the benefits that may be realized by the different embodiments are different, and in the different embodiments, the benefits that may be realized by any one or a combination of the above, or any other possible benefits may be realized.

The specification has the following technical effects: (1) The differentiation of physiological signals acquired by the first electrode group and the second electrode group can be realized through the differentiation design of the first electrode group and the second electrode group; (2) By means of the differential design of the two second electrodes in the second electrode group, differential physiological signals can be realized; (3) The differentiated physiological signals can reduce the interference of motion artifacts, so that the physiological signals with higher quality are extracted; (4) Due to the correlation between contact impedance and motion, the interference of motion artifacts in physiological signals is eliminated according to the contact impedance.

While the basic concepts have been described above, it will be apparent to those skilled in the art that the foregoing detailed disclosure is by way of example only and is not intended to be limiting. Although not explicitly described herein, various modifications, improvements and adaptations of the application may occur to one skilled in the art. Such modifications, improvements, and modifications are intended to be suggested within the present disclosure, and therefore, such modifications, improvements, and adaptations are intended to be within the spirit and scope of the exemplary embodiments of the present disclosure.

Meanwhile, the present application uses specific words to describe embodiments of the present application. Reference to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic is associated with at least one embodiment of the application. Thus, it should be emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various positions in this specification are not necessarily referring to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of the application may be combined as suitable.

Furthermore, the order in which the elements and sequences are processed, the use of numerical letters, or other designations are used in the application is not intended to limit the sequence of the processes and methods unless specifically recited in the claims. While certain presently useful inventive embodiments have been discussed in the foregoing disclosure, by way of example, it is to be understood that such details are merely illustrative and that the appended claims are not limited to the disclosed embodiments, but, on the contrary, are intended to cover all modifications and equivalent arrangements included within the spirit and scope of the embodiments of the application. For example, while the system components described above may be implemented by hardware devices, they may also be implemented solely by software solutions, such as installing the described system on an existing server or mobile device.

Similarly, it should be noted that in order to simplify the description of the present disclosure and thereby aid in understanding one or more inventive embodiments, various features are sometimes grouped together in a single embodiment, figure, or description thereof. This method of disclosure does not imply that the subject application requires more features than are set forth in the claims. Indeed, less than all of the features of a single embodiment disclosed above.

In some embodiments, numbers describing the components, number of attributes are used, it being understood that such numbers being used in the description of embodiments are modified in some examples by the modifier "about," approximately, "or" substantially. Unless otherwise indicated, "about," "approximately," or "substantially" indicate that the number allows for a 20% variation. Accordingly, in some embodiments, numerical parameters set forth in the specification and claims are approximations that may vary depending upon the desired properties sought to be obtained by the individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and employ a method for preserving the general number of digits. Although the numerical ranges and parameters set forth herein are approximations in some embodiments for use in determining the breadth of the range, in particular embodiments, the numerical values set forth herein are as precisely as possible.

Each patent, patent application publication, and other material, such as articles, books, specifications, publications, documents, etc., cited herein is hereby incorporated by reference in its entirety. Except for the application history file that is inconsistent or conflicting with this disclosure, the file (currently or later attached to this disclosure) that limits the broadest scope of the claims of this disclosure is also excluded. It is noted that the description, definition, and/or use of the term in the appended claims controls the description, definition, and/or use of the term in this application if the description, definition, and/or use of the term in the appended claims does not conform to or conflict with the present disclosure.

Finally, it should be understood that the embodiments of the present application are merely illustrative of the principles of the embodiments of the present application. Other variations are also possible within the scope of the application. Thus, by way of example, and not limitation, alternative configurations of embodiments of the application may be considered in keeping with the teachings of the application. Accordingly, the embodiments of the present application are not limited to the embodiments explicitly described and depicted herein.

Claims

1. A signal acquisition system comprising:

Wearing a body;

The electrodes are fixed on the wearing body and are in contact with the skin of a user, the electrodes comprise a first electrode group and a second electrode group, the first electrode group is used for collecting physiological signals, and the second electrode group is used for collecting detection signals; and

And the processing circuit is used for eliminating motion artifacts in the physiological signal according to the detection signal.

2. The signal acquisition system of claim 1, wherein the first electrode set includes two first electrodes arranged at intervals, the second electrode set includes two second electrodes arranged adjacent to the two first electrodes, respectively, the physiological signal is a first physiological signal, the detection signal is a second physiological signal, and the processing circuit is configured to cancel motion artifacts in the first physiological signal according to the second physiological signal.

3. The signal acquisition system of claim 2, wherein the two second electrodes satisfy at least one of the following conditions:

The conductivity of the materials of the two second electrodes is different;

The two second electrodes are different in height relative to the protrusions of the skin of the user along the direction perpendicular to the surface of the skin of the user;

The hardness of the materials of the two second electrodes is different;

the material of the two second electrodes has different wrinkling degrees; or (b)

The areas of the two second electrodes are different.

4. The signal acquisition system of claim 1 wherein the first electrode set comprises two first electrodes arranged in a spaced apart relationship and the second electrode set comprises one second electrode arranged adjacent one of the two first electrodes, wherein the second electrode and the first electrode adjacent thereto are used to acquire the detection signal.

5. The signal acquisition system of claim 2 or claim 4, wherein each second electrode satisfies at least one of the following conditions:

The material of each second electrode is weaker than the conductivity of the material of the corresponding first electrode;

The height of each second electrode relative to the protrusion of the wearing body is smaller than the height of the corresponding first electrode relative to the protrusion of the wearing body along the direction perpendicular to the skin surface of the user;

the second material of each second electrode is harder than the first material of the corresponding first electrode;

the second material of each second electrode is wrinkled to a greater extent than the first material of the corresponding first electrode; or (b)

The area of each second electrode contacted with the skin is smaller than the area of the corresponding first electrode contacted with the skin.

6. The signal acquisition system of claim 1, wherein the first electrode set comprises two first electrodes arranged at intervals, the second electrode set comprises two second electrodes arranged adjacent to the two first electrodes, respectively, and the detection signal is a detection signal reflecting contact impedance between the two first electrodes and the skin of the user.

7. The signal acquisition system of claim 6 further comprising an excitation source electrically connected to the two second electrodes, the excitation source for providing an excitation signal.

8. The signal acquisition system of claim 7, wherein the physiological signal has a frequency in the range of 20Hz-400Hz and the excitation signal has a frequency of not less than 250Hz.

9. The signal acquisition system of claim 8, wherein the excitation signal has a frequency that differs from any integer multiple of 50Hz by no less than 1Hz; or the difference between the frequency of the excitation signal and any integer multiple of 60Hz is not less than 1Hz.

10. The signal acquisition system of claim 6, wherein the excitation signal has a frequency that is higher than a frequency range of the physiological signal.

11. The signal acquisition system of claim 6, wherein the detection signal and the physiological signal are acquired separately over different time periods.

12. The signal acquisition system of claim 2, wherein a minimum distance between an edge of each second electrode and an edge of the corresponding first electrode is less than 10cm.

13. The signal acquisition system of claim 2, wherein each second electrode is connected to one of the first electrodes by a non-elastic connection, and wherein a ratio of a distance difference between a movable distance of the second electrode and the corresponding first electrode on a surface parallel to the skin surface to a movable distance of the corresponding first electrode on a surface parallel to the skin surface is not more than 50%.

14. The signal acquisition system of claim 1, wherein the processing circuit is configured to:

Differentially processing the signals acquired by the two first electrodes to obtain physiological signals;

And eliminating motion artifacts in the physiological signal according to the detection signal.

15. The signal acquisition system of claim 1, further comprising an inertial sensor disposed on a side of the first electrode set facing away from the skin of the user and configured to measure motion artifacts of the first electrode set.

16. A signal acquisition system comprising:

Wearing a body;

A plurality of electrodes fixed to the wearing body and contacting the skin of the user, the plurality of electrodes including two electrodes arranged at intervals to collect physiological signals;

An excitation source electrically connected to the two electrodes, the excitation source for providing an excitation signal to generate a detection signal reflecting an impedance of contact between the two electrodes and the skin of the user; and