Head wearable device, electroencephalogram signal detection method and device and storage medium

Abstract

The invention discloses a head wearing device, an electroencephalogram signal detection method and device and a storage medium. The head wearing equipment comprises a flexible device and a processing device. The flexible device can be in contact with the head of a target user of which electroencephalogram signals are to be collected; a plurality of conductive electrodes of the flexible device comprise a grounding electrode and a plurality of induction electrode groups, each induction electrode group comprises at least two induction electrodes which are adjacent in position, one of the induction electrodes serves as a reference electrode, and the rest of the induction electrodes serve as acquisition electrodes. The processing device is used for applying voltage to the acquisition electrode and the reference electrode and obtaining voltage difference. According to the application, the reference electrode and the at least one acquisition electrode which are adjacent to each other form the distribution of each induction electrode group, so that the interference of other physiological electric signals on the detection of the electroencephalogram signal due to the long distance between the acquisition electrode and the reference electrode can be reduced, and the acquired electroencephalogram signal is more effective.

Description

Technical Field

[0001] The present application relates to the field of signal processing, and in particular to a head-worn device, an electroencephalogram (EEG) signal detection method, device and storage medium. Background Art

[0002] EEG signals are a basic physiological signal of the human body and have important clinical diagnostic and medical value. At the same time, EEG signals can also realize information exchange between the brain and the device, thereby improving human-computer interaction capabilities and enriching people's daily lives.

[0003] In the traditional method, EEG signals are collected through an EEG cap, but conductive gel is required between the collection electrodes and the skin to ensure contact stability, which is not portable and comfortable to wear. In recent years, sufficient research has shown that effective EEG signals can also be obtained by directly contacting the surface of the human head with the collection electrodes. However, the method of obtaining EEG signals by directly contacting the surface of the human head with the collection electrodes still has shortcomings. For example, it is easy to be interfered by signals when obtaining EEG signals. Summary of the invention

[0004] The present application provides a head-worn device, an electroencephalogram (EEG) signal detection method, device, and storage medium, which can effectively obtain EEG signals. The technical solution is as follows:

[0005] In a first aspect, a head-worn device is provided, which includes a flexible device and a processing device. The flexible device has a plurality of conductive electrodes electrically connected to the processing device, and the plurality of conductive electrodes are distributed in the flexible device and arranged in a ring shape. The plurality of conductive electrodes include a ground electrode and a plurality of sensing electrode groups, each sensing electrode group includes at least two sensing electrodes adjacent to each other, one of the at least two sensing electrodes serves as a reference electrode, and the rest serve as collection electrodes. The processing device is used to apply voltages to the collection electrode and the reference electrode, respectively, and obtain the EEG signal of the target user based on the collection electrode and the reference electrode in the same sensing electrode group.

[0006] The surface material of the flexible device can be a relatively soft material such as fabric, leather, etc. The conductive electrode on the surface of the flexible device is a dry electrode, which refers to an electrode that can directly contact the skin without applying conductive gel between the electrode and the skin.

[0007] Since the surface material of the flexible device of the head wearable device is relatively soft, and the conductive electrodes on the surface of the flexible device can directly contact the skin, it can bring a comfortable and convenient wearing experience to the target user. In addition, since each sensing electrode group of the flexible device includes at least two sensing electrodes adjacent to each other, one of the at least two sensing electrodes is used as a reference electrode, and the rest are used as collection electrodes, that is, each sensing electrode group includes a reference electrode and at least one collection electrode, and the distance between the collection electrode and the reference electrode in the same sensing electrode group is relatively close. Therefore, when determining the EEG signal of the target user through the reference electrodes and collection electrodes in these sensing electrode groups, the collection electrodes in each sensing electrode group use their respective corresponding reference electrodes, instead of all the collection electrodes in these sensing electrode groups sharing the same collection electrode, which can reduce the interference of physiological electrical signals or motion artifacts generated in other parts of the head or other parts of the body due to the long distance between the collection electrode and the reference electrode on the detection of EEG signals, making the acquired EEG signals more effective.

[0008] Optionally, the sensing electrode group used to determine the brain electrical signal is a partial sensing electrode group among multiple sensing electrode groups.

[0009] Since the EEG signals of the target user are collected through some of the multiple sensing electrode groups during the actual EEG signal detection, the processing device only needs to process a limited number of signals instead of all the signals, which reduces the system complexity and speeds up the processing.

[0010] Optionally, the angle information of the flexible device corresponds to the sensing electrode group used to determine the EEG signal, and when the angle of the flexible device is different, the sensing electrode group used to determine the EEG signal is different.

[0011] Since effective EEG signals can only be obtained at certain positions of the user's head, but not at all positions, only some of the multiple sensing electrode groups of the flexible device may be able to collect effective EEG signals. However, the angle of the flexible device in actual applications is not necessarily fixed. For example, when the flexible device is worn in different ways, the angle of the flexible device is different. If some of the sensing electrode groups in the above-mentioned multiple sensing electrode groups are fixed as sensing electrode groups for determining EEG signals, then at certain angles, effective EEG signals may not be obtained. Based on this, by setting the corresponding relationship between the angle of the flexible device and the sensing electrode group used to determine the EEG signal, different sensing electrode groups can be selected to collect EEG signals at different angles of the flexible device, so that effective EEG signals can be obtained through a limited number of sensing electrode groups at different angles.

[0012] Optionally, the conductive electrode is in a long strip structure, and the long sides of the conductive electrode are distributed along the circumference of the ring.

[0013] Through the above distribution method, the distribution area of ​​the conductive electrodes along the radial direction of the ring can be reduced, avoiding the conductive electrodes being distributed in the area of ​​the flexible device near the central area with larger deformation, which causes the contact impedance with the skin to be affected by the bending or stretching of the flexible device. It can also ensure that the conductive electrodes can fully contact the skin of the target user under different wearing tightness of the head wearable device, ensuring that the contact impedance between the conductive electrodes and the skin changes as the wearing tightness is minimized.

[0014] Optionally, the conductive electrode includes a site electrode located on the surface of the flexible device and a thin film electrode located inside the flexible device, and the site electrode and the thin film electrode are connected by a conductive glue.

[0015] Since the conductive electrode is composed of a site electrode and a thin film electrode, that is, the conductive electrode is composed of two layers of electrodes, the conductive electrode can also be called a composite layer conductive electrode.

[0016] Since the site electrodes are located on the surface of a relatively soft flexible device, they can provide the target user with a comfortable wearing experience when collecting the target user's EEG signals.

[0017] Optionally, the thin film electrode is a stretchable structure.

[0018] This stretchable structure enables the thin film electrode to achieve ultra-high electrical performance while having excellent mechanical strength and sufficient flexibility. In other words, the thin film electrode has a certain degree of stretchability and the resistance does not change significantly.

[0019] Since the flexible device will inevitably be bent or stretched when the target user wears the head wearable device, when the site electrode is placed on the surface of the flexible device by printing, the site electrode itself on the surface of the flexible device is not a continuous layer of conductive material, but a series of conductive particles. When the site electrode is bent or stretched by the contact force, the conductive particles inside it will separate to a certain extent. Therefore, by placing a thin film electrode with a stretchable structure under the site electrode and connecting it to the site electrode to form a composite layer conductive electrode, it is possible to avoid the resistance of the composite layer conductive electrode constantly changing with the bending or stretching of the flexible device, thereby being able to obtain EEG signals more stably.

[0020] Optionally, the thin film electrode includes a flexible thin film substrate and a metal coating located on the surface of the flexible thin film substrate.

[0021] Optionally, the head-worn device is a headset, the flexible device is an earmuff, and the head-worn device further includes a connector having a symmetrical first connecting end and a second connecting end, and each of the first connecting end and the second connecting end is connected to a flexible device.

[0022] In a second aspect, a method for detecting EEG signals based on the head wearable device is provided, which is applied to the processing device, and comprises: applying voltages to the collection electrode and the reference electrode respectively, obtaining the voltage difference between the contact voltages of the collection electrode and the reference electrode in the same sensing electrode group and the head of the target user respectively, and determining the EEG signal of the target user based on the voltage difference.

[0023] Optionally, applying voltages to the collection electrodes and the reference electrodes respectively includes: selecting a portion of the sensing electrode groups from the plurality of sensing electrode groups as target sensing electrode groups, and applying voltages to the collection electrodes and the reference electrodes in the target sensing electrode groups.

[0024] Since not all areas of the human head can effectively acquire EEG signals, it is only necessary to apply voltage to the sensing electrode group located in the area of ​​the head that can acquire effective EEG signals to collect EEG signals. In this way, only a limited number of signals are processed each time EEG signal detection is performed, without processing all signals, which reduces the complexity of the system and makes the signal processing process faster.

[0025] Optionally, selecting some sensing electrode groups from the plurality of sensing electrode groups as target sensing electrode groups includes: determining an angle of the flexible device, and determining the target sensing electrode group from a target correspondence relationship based on the angle of the flexible device. The target correspondence relationship is used to record the correspondence between the angle information of the flexible device and the sensing electrode group used to determine the EEG signal, and when the angle of the flexible device is different, the sensing electrode group used to determine the EEG signal is different.

[0026] In actual applications, the angle of the flexible device may be offset, and only certain areas of the head can effectively acquire EEG signals. If a fixed sensing electrode group is used as the target sensing electrode group for determining the EEG signal, the target sensing electrode group and the effective area of ​​the head that can acquire the EEG signal will be offset. Therefore, by determining the correspondence between different angles and the sensing electrode groups located in the effective area of ​​the head, different sensing electrode groups are selected at different angles to collect EEG signals. In this way, effective EEG signals can be acquired through a limited number of sensing electrode groups at different angles.

[0027] Optionally, before applying voltage to the collection electrode and the reference electrode, the method further comprises: in a case where the target user wears the flexible device, executing the step of applying voltage to the collection electrode and the reference electrode.

[0028] When the target user wears the flexible device, the step of applying voltage to the collection electrode and the reference electrode is performed, thereby avoiding waste of electricity and further avoiding ineffective consumption of system resources.

[0029] In a third aspect, an electroencephalogram signal detection device is provided, which has the function of implementing the electroencephalogram signal detection method in the second aspect. The electroencephalogram signal detection device includes at least one module, and the at least one module is used to implement the electroencephalogram signal detection method provided in the second aspect.

[0030] In a fourth aspect, a computer-readable storage medium is provided, wherein instructions are stored in the storage medium. When the instructions are executed on a computer, the computer executes the steps of the EEG signal detection method described in the second aspect.

[0031] In a fifth aspect, a computer program product comprising instructions is provided, which, when executed on a computer, enables the computer to execute the steps of the EEG signal detection method of the second aspect. In other words, a computer program is provided, which, when executed on a computer, enables the computer to execute the steps of the EEG signal detection method of the second aspect.

[0032] The technical effects obtained by the above-mentioned third aspect, fourth aspect and fifth aspect are similar to the technical effects obtained by the corresponding technical means in the second aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a structural schematic diagram of a head wearable device provided in an embodiment of the present application;

[0034] Figure 2 is a schematic structural diagram of a headset provided in an embodiment of the present application;

[0035] Figure 3 This is a schematic diagram of the position of the head area corresponding to a sensing electrode group provided in an embodiment of the present application;

[0036] Figure 4 is a schematic diagram of the structure of a smart eye mask provided in an embodiment of the present application;

[0037] Figure 5 is a schematic diagram of the position of the head area corresponding to another sensing electrode group provided in an embodiment of the present application;

[0038] Figure 6 Schematic diagram of the position distribution of three different conductive electrodes provided in the embodiments of the present application;

[0039] Figure 7 The same wearing tightness is provided in the embodiment of the present application. Figure 6 Schematic diagram of the contact impedance between the conductive electrodes and the skin in three distribution modes shown;

[0040] Figure 8 The present invention provides three different wearing tightness levels. Figure 6 Schematic diagram of the contact impedance between the conductive electrodes and the skin in three distribution modes shown;

[0041] Fig. 9 is a schematic structural diagram of a conductive electrode provided in an embodiment of the present application;

[0042] Fig.10 is a schematic diagram of a stretchable structure provided in an embodiment of the present application;

[0043] Fig.11 is a line graph of resistance changes of two different conductive electrodes under different bending and stretching times provided in an embodiment of the present application;

[0044] Fig.12 It is a structural schematic diagram of a wearable medical monitor provided in an embodiment of the present application;

[0045] Fig.13 is a flow chart of an EEG signal detection method provided in an embodiment of the present application;

[0046] Fig.14 is a schematic diagram of the position distribution of conductive electrodes of a headset provided in an embodiment of the present application;

[0047] Fig.15 is a schematic diagram of the position of the target sensing electrode group in three different situations provided in the embodiments of the present application;

[0048] Fig.16 It is a structural schematic diagram of an electroencephalogram detection device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0049] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the implementation methods of the present application will be further described in detail below in conjunction with the accompanying drawings.

[0050] Before explaining in detail the head-worn device and the EEG signal detection method provided in the embodiments of the present application, the application scenarios involved in the embodiments of the present application are first introduced.

[0051] EEG signals are a basic physiological signal of the human body and have important clinical diagnostic and medical value. At the same time, EEG signals can also be used to exchange information between the brain and the device, that is, by detecting changes in EEG signals to reflect the external stimulation of the human senses, thereby improving human-computer interaction capabilities and enriching people's daily lives. By using the head-worn device and the corresponding EEG signal detection method provided in the embodiment of the present application, while ensuring comfortable and convenient wearing, effective EEG signals can be obtained for application. Next, several application scenarios of the head-worn device and the EEG signal detection method are introduced.

[0052] Scenario 1: For some patients whose brain functions are intact but whose neuromuscular functions are damaged, the head wearable device provided in the embodiment of the present application can obtain the EEG signals of these patients, thereby realizing the communication control between the brain and the external environment through the obtained EEG signals. For example, patients can use their thoughts to realize the switching of lights, answering of telephones, control of electric wheelchairs, etc. This technology expands the range of activities of patients and has a positive effect on the rehabilitation training of patients.

[0053] Scene 2: EEG Figure 1 It has been widely used in the diagnosis and treatment of brain diseases, such as epilepsy, impaired consciousness, etc. By using the head wearable device provided in the embodiment of the present application, EEG signals can be easily obtained, giving patients a comfortable diagnosis and treatment experience. Moreover, the EEG signal detection method provided in the embodiment of the present application can more effectively obtain EEG signals, helping doctors to make more accurate diagnoses.

[0054] Scenario 3: For some games, the head wearable device provided in the embodiment of the present application can be used to obtain the EEG signals of the game player, and use these EEG signals of the game player to control the virtual props or virtual objects in the game, that is, directly control the virtual props or virtual objects in the game through the game player's thinking. This type of game can bring more novel experiences to the game players. While the players enjoy a colorful game time, they also exercise their brains and reaction abilities.

[0055] It should be noted that the application scenarios described in the embodiments of the present application are intended to more clearly illustrate the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided in the embodiments of the present application. A person of ordinary skill in the art can appreciate that, with the evolution of application scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

[0056] Next, the head wearable device provided in the embodiment of the present application is explained in detail.

[0057] Please refer to Figure 1 , Figure 1: is a schematic diagram of the structure of a head-worn device provided in an embodiment of the present application, and the head-worn device includes a flexible device 1 and a processing device 2. The flexible device 1 has a plurality of conductive electrodes 11 electrically connected to the processing device 2, and the plurality of conductive electrodes 11 are distributed in the flexible device and arranged in a ring shape; the plurality of conductive electrodes 11 include a ground electrode and a plurality of sensing electrode groups, and each sensing electrode group includes at least two sensing electrodes adjacent to each other, one of the at least two sensing electrodes serves as a reference electrode, and the rest serve as collection electrodes. The processing device 2 is used to apply voltages to the collection electrode and the reference electrode, respectively, and obtain the EEG signal of the target user based on the collection electrode and the reference electrode in the same sensing electrode group.

[0058] Since the head wearable device is in direct contact with the target user's skin through a flexible device, and the surface material of the flexible device is relatively soft, it can provide the target user with a comfortable and convenient wearing experience. In addition, since each sensing electrode group of the flexible device includes at least two sensing electrodes in adjacent positions, one of the at least two sensing electrodes is used as a reference electrode, and the rest are used as collection electrodes, that is, each sensing electrode group includes a reference electrode and at least one collection electrode, and the distance between the collection electrode and the reference electrode in the same sensing electrode group is relatively close, therefore, when determining the target user's EEG signal through the reference electrodes and collection electrodes in these sensing electrode groups, the collection electrodes in each sensing electrode group use their respective corresponding reference electrodes, rather than all the collection electrodes in these sensing electrode groups sharing the same collection electrode, which can reduce the interference of physiological electrical signals or motion artifacts generated in other parts of the head or other parts of the body due to the long distance between the collection electrode and the reference electrode on the detection of EEG signals, making the acquired EEG signals more effective.

[0059] The number and form of the flexible device 1 included in the head-worn device can be adjusted according to the form and application scenario of the head-worn device, and the embodiments of the present application do not limit this. The surface material of the flexible device 1 can be a relatively soft material such as fabric and leather. The conductive electrode 11 on the surface of the flexible device 1 is a dry electrode, which refers to an electrode that can directly contact the skin, and there is no need to apply conductive gel between the electrode and the skin. Among them, the conductive electrode 11 on the surface of the flexible device 1 can have different names according to different functions, that is, a conductive electrode with a grounding function is called a grounding electrode, and a conductive electrode with a signal sensing function is called a sensing electrode.

[0060] The processing device 2 may be a general-purpose central processing unit (CPU), a network processor (NP), a microprocessor, or may be one or more integrated circuits for implementing the solution of the present application, such as an application-specific integrated circuit (ASIC), a programmable logic device (PLD) or a combination thereof. The above-mentioned PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL) or any combination thereof.

[0061] Based on the above description, each sensing electrode group includes at least two sensing electrodes adjacent to each other, that is, each sensing electrode group includes two or more sensing electrodes. When each sensing electrode group includes two sensing electrodes adjacent to each other, one of the two sensing electrodes is used as a reference electrode, and the other sensing electrode is used as a collection electrode, so that each two adjacent sensing electrodes form a sensing electrode group, and one reference electrode corresponds to one collection electrode. For example, the distribution form of the collection electrodes and the reference electrodes in the multiple sensing electrode groups is: collection electrode, reference electrode, collection electrode, reference electrode, etc. When each sensing electrode group includes two or more sensing electrodes adjacent to each other, one of the two or more sensing electrodes is used as a reference electrode, and the remaining sensing electrodes are used as collection electrodes, so that each two or more adjacent sensing electrodes form a sensing electrode group, and one reference electrode corresponds to at least one collection electrode. For example, each sensing electrode group includes two collection electrodes, and the distribution form of the collection electrodes and the reference electrodes in the multiple sensing electrode groups is: collection electrode, collection electrode, reference electrode, collection electrode, collection electrode, reference electrode, etc.

[0062] It should be noted that the number of collection electrodes included in different sensing electrode groups may be the same or different. In other words, the number of sensing electrodes included in different sensing electrode groups in the multiple sensing electrode groups may be the same or different. Moreover, the roles of the collection electrodes and the reference electrodes in the multiple sensing electrode groups are not fixed, that is, for a sensing electrode, the sensing electrode can be used not only as a collection electrode but also as a reference electrode, which is not limited in the embodiments of the present application.

[0063] Since a contact impedance is generated when the sensing electrode contacts the skin, when a voltage is applied to the surface of the sensing electrode to form a loop, the contact voltage between the collection electrode and the skin and the contact voltage between the reference electrode and the skin can be obtained. Therefore, when the EEG signal of the target user is obtained based on the collection electrode and the reference electrode in the same sensing electrode group, the EEG signal can be determined by the voltage difference between the two contact voltages. In the traditional EEG signal detection device, there is only one conductive electrode as the reference electrode, and all collection electrodes share this reference electrode. This method is called a unipolar lead method. Although the distribution of the conductive electrodes in the unipolar lead method is simple, the distance between some collection electrodes and the reference electrode is far, which makes it easy to be interfered by physiological electrical signals or motion artifacts generated in other parts of the head or other parts of the body when obtaining EEG signals, which is reflected in the fact that the voltage amplitude of the acquired EEG signal is basically outside the voltage range of the EEG signal. In the embodiment of the present application, each sensing electrode group includes a reference electrode, and the distance between the collection electrode and the reference electrode in the same sensing electrode group is relatively close. When collecting EEG signals, the collection electrodes in each sensing electrode group use their respective corresponding reference electrodes, so that the voltage difference obtained by each sensing electrode group is more stable, thereby reducing such interference and obtaining EEG signals more effectively.

[0064] In some embodiments, the sensing electrode group used to determine the EEG signal is a partial sensing electrode group among the above-mentioned multiple sensing electrode groups. That is, when realizing the detection of EEG signals, the EEG signals of the target user are collected through some sensing electrode groups among the multiple sensing electrode groups of the flexible device 1. In this case, the processing device 2 only needs to process a limited number of signals instead of all signals, the system complexity is low, and the processing process is faster. Of course, in practical applications, the EEG signals of the target user can also be collected through all the sensing electrode groups, and the embodiments of the present application are not limited to this.

[0065] In some embodiments, the angle information of the flexible device 1 corresponds to the sensing electrode group used to determine the EEG signal, and when the angle of the flexible device 1 is different, the sensing electrode group used to determine the EEG signal is different.

[0066] Since effective EEG signals can only be obtained at certain positions of the user's head, but not at all positions, only some of the multiple sensing electrode groups of the flexible device 1 may be able to collect effective EEG signals. However, in actual applications, the angle of the flexible device 1 is not necessarily fixed. For example, when the flexible device 1 is worn in different ways, the angle of the flexible device 1 is different. If some of the sensing electrode groups in the above-mentioned multiple sensing electrode groups are fixed as sensing electrode groups for determining EEG signals, then at certain angles, effective EEG signals may not be obtained. Based on this, the embodiment of the present application sets the corresponding relationship between the angle information of the flexible device 1 and the sensing electrode group used to determine the EEG signal, so that at different angles of the flexible device 1, different sensing electrode groups are selected to collect EEG signals, so that effective EEG signals can be obtained through a limited number of sensing electrode groups at different angles.

[0067] As an example, Figure 2 and Figure 3 As shown, the head wearable device is a headset, and the flexible device is an ear bag. Taking the left ear bag as an example, the left ear bag has a ground electrode and six sensing electrode groups. The ground electrode is recorded as GND, and the six sensing electrode groups are recorded as C1, C2, C3, C4, C5 and C6. When the headset is perpendicular to the user's head, it can be known through experiments that Figure 2 The three sensing electrode groups C2, C3 and C5 in the flexible device can collect EEG signals more effectively, that is, the areas around the left ear of the target user corresponding to the three sensing electrode groups C2, C3 and C5 can collect EEG signals more effectively. However, when the angle of the flexible device changes, the sensing electrode groups in contact with the three areas around the left ear of the target user may shift, and the experimental results show that the shift will reduce the effectiveness of obtaining EEG signals. Therefore, by setting the corresponding relationship between the angle information of the flexible device and the sensing electrode group used to determine the EEG signal, different sensing electrode groups are used to collect EEG signals at different angles of the flexible device, which can compensate for the problem of reduced effectiveness of obtaining EEG signals due to angle shift to a certain extent.

[0068] As another example, Figure 4 and Figure 5 As shown, the head wearable device is a smart eye mask, and the flexible device is an eye mask piece inside the eye mask body. Taking the right eye mask piece as an example, the right eye mask piece has a ground electrode and four sensing electrode groups, the ground electrode is recorded as GND, and the four sensing electrode groups are recorded as F1, F2, F3 and F4 respectively. When the smart eye mask is worn in the middle of the user's head, it can be known through experiments that Figure 4The two sensing electrode groups F2 and F3 in the flexible device can collect EEG signals more effectively, that is, the areas around the right eye of the target user corresponding to the two sensing electrode groups F2 and F3 can collect EEG signals more effectively. However, when the angle of the flexible device changes, the sensing electrode groups in contact with the two areas around the right eye of the target user may shift, and experimental results show that the shift will reduce the effectiveness of obtaining EEG signals. Therefore, by setting the corresponding relationship between the angle information of the flexible device and the sensing electrode group used to determine the EEG signal, different sensing electrode groups are used to collect EEG signals at different angles of the flexible device, which can compensate for the problem of reduced effectiveness of obtaining EEG signals due to angle shift to a certain extent.

[0069] In some embodiments, the head wearable device further includes but is not limited to at least one of the following sensors: an acceleration sensor, a gravity sensor, a direction sensor, and a rotation vector sensor. These sensors are used to sense the angle at which the target user wears the flexible device 1, so that the processing device 2 can select the corresponding sensing electrode group to collect the EEG signal, and realize the automatic switching of the sensing electrode group used to collect the EEG signal at different angles.

[0070] Based on the above description, the conductive electrode 11 is a dry electrode. Next, the conductive electrode involved in the embodiment of the present application is introduced.

[0071] In some embodiments, Figure 1 As shown, the conductive electrode 11 is in a long strip structure, and the long side of the conductive electrode 11 is distributed along the circumference of the ring. Through this distribution method, the distribution area of ​​the conductive electrode along the radial direction of the ring can be reduced, and the conductive electrode is distributed in the area of ​​the flexible device near the center area where the deformation is large, which causes the contact impedance with the skin to be affected by the bending or stretching of the flexible device. It can also make the conductive electrode fully contact with the target user's skin under different wearing tightness of the head wearable device, ensuring that the contact impedance between the conductive electrode and the skin changes as the wearing tightness is minimized.

[0072] For example, Figure 6 Three different distributions of conductive electrodes are shown. Figure 6 The left figure is a schematic diagram of the distribution of the long side of the conductive electrode of the long strip structure along the annular circumference, which is recorded as distribution mode 1; Figure 6 The middle figure is a schematic diagram of the distribution of the conductive electrodes of the disc-shaped structure on the surface of the flexible device, which is denoted as distribution mode 2; Figure 6 The right figure is a schematic diagram of the annular circumferential distribution of the short sides of the conductive electrode of the long strip structure. This distribution method is also called radial distribution method and is recorded as distribution method 3.

[0073] Figure 7 It shows that under a certain degree of wearing tightness, Figure 6 The contact impedance between the conductive electrode and the skin under the three distribution modes shown in the figure is Figure 7 It can be seen that when wearing the same tightness, Figure 6 The contact impedance between the conductive electrode and the skin is the smallest under the distribution mode 1 shown, and the contact impedance between the conductive electrode and the skin is relatively large under the distribution modes 2 and 3. This is because compared with the distribution modes 2 and 3, the distribution mode 1 can reduce the distribution area of ​​the conductive electrode in the radial direction along the ring of the flexible device, and reduce the distribution area of ​​the conductive electrode in the flexible device near the central area where the deformation is large, thereby avoiding the contact impedance between the conductive electrode and the skin being affected by the bending or stretching of the flexible device.

[0074] Figure 8 Shows the wearing conditions at three different tightness levels. Figure 6 The contact impedance between the conductive electrode and the skin under the three distribution modes shown in the figure is Figure 8 It can be seen that under different wearing tightness, the contact impedance between the conductive electrode and the skin is the smallest under distribution mode 1. This is because compared with distribution modes 2 and 3, distribution mode 1 allows the conductive electrode to fully contact the user's skin under different wearing tightness, thereby maintaining the stability of the contact impedance.

[0075] In some embodiments, please refer to Fig. 9 The conductive electrode 11 includes a site electrode 111 located on the surface of the flexible device 1 and a film electrode 112 located inside the flexible device 1 . The site electrode 111 and the film electrode 112 are connected via a conductive adhesive 113 .

[0076] Since the conductive electrode 11 is composed of a site electrode 111 and a thin film electrode 112 , that is, the conductive electrode 11 is composed of two layers of electrodes, the conductive electrode 11 can also be called a composite layer conductive electrode.

[0077] The site electrode 111 on the surface of the flexible device 1 is used to directly contact the skin of the target user, and the site electrode 111 can be a printed electrode on the surface of the flexible device 1. By printing the site electrode 111 on the surface of the relatively soft flexible device 1, the EEG signal of the target user can be collected while providing the target user with a comfortable wearing experience. Of course, in actual applications, under the condition of satisfying a certain wearing comfort, the site electrode can also be set on the surface of the flexible device 1 in other ways, and the embodiments of the present application are not limited to this.

[0078] The thin film electrode 112 inside the flexible device 1 is used as a conductive circuit to realize signal transmission between the site electrode 111 and the processing device 2. The conductive glue 113 between the site electrode 111 and the thin film electrode 112 is made of a special conductive polymer or antimony tin oxide, has low resistance, and is used as a conductive path between the site electrode 111 and the thin film electrode 112.

[0079] In some embodiments, please refer to Fig.10 The thin film electrode 112 is a stretchable structure. In this way, while achieving ultra-high electrical performance, it also has excellent mechanical strength and sufficient flexibility, so that the thin film electrode 112 has a certain degree of stretchability and the resistance does not change significantly.

[0080] The stretchable structure may be a wavy structure, a serpentine structure, or other structures with high ductility, which is not limited in the embodiments of the present application.

[0081] When the target user wears the head wearable device, the flexible device will inevitably be bent or stretched. When the site electrode is placed on the surface of the flexible device by printing, the site electrode itself on the surface of the flexible device is not a continuous layer of conductive material, but a series of conductive particles. When the site electrode is bent or stretched by contact force, the conductive particles inside it will separate to a certain extent. Therefore, by placing a thin film electrode under the site electrode and connecting it to the site electrode to form a composite layer conductive electrode, the resistance of the composite layer conductive electrode can be prevented from constantly changing with the bending or stretching of the flexible device, so that EEG signals can be obtained more stably.

[0082] For example, Fig.11 The left and right figures show the resistance changes of two different conductive electrodes under different bending and stretching times. These two conductive electrodes are respectively a conductive electrode formed by printing silver paste on the surface of a flexible device made of leather (also called a leather printed silver paste conductive electrode) and a composite layer conductive electrode with a stretchable structure. Fig.11 It can be seen that the resistance of the conductive electrode formed by printing silver paste on the surface of the flexible device made of leather material will increase rapidly after being bent or stretched more than 100 times, while the resistance of the composite layer conductive electrode with a stretchable structure is still small when it is bent or stretched 10,000 times, and the resistance is almost unchanged compared to when it was not bent or stretched at the beginning. It can be seen that the use of composite layer conductive electrodes with a stretchable structure can maintain the stability of the conductive electrode resistance and maintain good conductive properties under bending or stretching conditions, compared to printed electrodes only on the surface of materials such as fabrics or leather.

[0083] In some embodiments, the thin film electrode 112 includes a flexible thin film substrate and a metal coating layer located on the surface of the flexible thin film substrate.

[0084] Among them, the flexible film substrate can be made of thermoplastic polyester, polyimide and other materials, and the metal coating on the surface can be made of gold, silver, copper and other materials. The embodiment of the present application does not limit the materials of the flexible film substrate and the metal coating on the surface of the substrate.

[0085] In some embodiments, the head-mounted device further includes a proximity sensor. The proximity sensor is used to sense whether the target user is wearing a flexible device, and the processing device 2 in the head-mounted device uses this to determine whether to apply voltage to the collection electrode and the reference electrode and detect the EEG signal. The proximity sensor includes but is not limited to at least one of the following: a magnetic proximity sensor, a capacitive sensor, and a photoelectric sensor. Of course, in actual applications, the proximity sensor can also be of other types, which is not limited in the embodiments of the present application.

[0086] In the embodiments of the present application, the head-worn device may be headphones, or may be a smart eye mask, smart glasses, a wearable medical monitor, an AR device, a VR device, a hat, etc. The embodiments of the present application do not limit the form of the head-worn device.

[0087] In some embodiments, please refer to Figure 2 The head-worn device is a headset, the flexible device 1 is an ear bag, and the head-worn device further comprises a connector 3, the connector 3 has a symmetrical first connection end and a second connection end, and the first connection end and the second connection end are both connected to a flexible device 1. In other words, the headset comprises two flexible devices 1, which are left and right ear bags.

[0088] The left ear bag and the right ear bag of the headset share a grounding electrode, that is, there is only one grounding electrode in the flexible device 1 of the headset, and the grounding electrode can be located in the left ear bag or in the right ear bag. In addition to the grounding electrode, the left and right ear bags also have the above-mentioned sensing electrode group. The number of sensing electrode groups in the left and right ear bags can be the same or different, and the number of collection electrodes in each sensing electrode group can be the same or different, that is, the number of conductive electrodes in the left and right ear bags can be the same or different, and the embodiment of the present application does not limit this. Of course, in actual applications, the left ear bag and the right ear bag can also have their own independent grounding electrodes, and the embodiment of the present application does not limit this.

[0089] In other embodiments, please refer to Figure 4The head-worn device is a smart eye mask, the flexible device 1 is an eye mask piece inside the main body of the smart eye mask, and the head-worn device further comprises a connector 3, the connector 3 has a symmetrical first connection end and a second connection end, and the first connection end and the second connection end are respectively connected to the left and right sides of the flexible device 1. In other words, the smart eye mask comprises two flexible devices 1, which are respectively the left and right eye mask pieces.

[0090] The left eye mask piece and the right eye mask piece of the smart eye mask share a grounding electrode, that is, there is only one grounding electrode in the flexible device 1 of the smart eye mask, and the grounding electrode can be located in the left eye mask piece or in the right eye mask piece. In addition to the grounding electrode, the left and right eye mask pieces also have the above-mentioned sensing electrode group. The number of sensing electrode groups in the left and right eye mask pieces can be the same or different, and the number of collection electrodes in each sensing electrode group can be the same or different, that is, the number of conductive electrodes in the left and right eye mask pieces can be the same or different, and the embodiment of the present application does not limit this. Of course, in actual applications, the left ear ear bag and the right ear ear bag can also have their own independent grounding electrodes, and the embodiment of the present application does not limit this.

[0091] In other embodiments, please refer to Fig.12 , the head-worn device is a wearable medical monitor, and the flexible device 1 is a headband (shown by the dotted line) inside the main body of the wearable medical monitor. Optionally, the head-worn device further includes a connector 3, the connector 3 having a symmetrical first connector end and a second connector end, the first connector end and the second connector end are respectively connected to the left and right sides of the flexible device 1.

[0092] In the embodiment of the present application, since the conductive electrode in the flexible device is a dry electrode that can directly contact the skin of the target user, it is not necessary to apply conductive gel between the skin of the target user and the conductive electrode when detecting EEG signals, which can reduce the cumbersome steps of applying conductive gel, making the EEG signal detection process more convenient, and also improve the comfort of the target user when detecting EEG signals. In addition, the distribution of the conductive electrodes in the flexible device is not the unipolar lead distribution in the traditional EEG signal detection device, but the distribution of each sensing electrode group is formed by a reference electrode and at least one acquisition electrode in adjacent positions. Such a distribution avoids the problem that the distance between some acquisition electrodes and the reference electrode in the unipolar lead distribution is far, which makes it easy to be interfered by physiological electrical signals or motion artifacts generated in other parts of the head or other parts of the body when acquiring EEG signals, so that the voltage difference obtained by each sensing electrode group is more stable, and thus the EEG signals can be acquired more effectively.

[0093] Moreover, the sensing electrode group used to determine the EEG signal is only a part of the sensing electrode group, and through the coordinated processing of appropriate sensors and processing devices, it can be achieved that at different angles of the flexible device, a limited number of sensing electrode groups can be used to obtain sufficiently effective EEG signals, so that the processing device only needs to process a limited number of signals, and does not need to process all signals. The complexity of the system is low and the processing process is faster. At the same time, the conductive electrodes of the flexible device are in a long strip structure, and the long sides of the conductive electrodes are distributed along the circumference of the ring. Through this distribution method, the distribution area of ​​the conductive electrodes along the radial direction of the ring can be reduced, avoiding the conductive electrodes being distributed in the area of ​​the flexible device near the central area where the deformation is larger, resulting in the contact impedance with the skin being affected by the bending or stretching of the flexible device, and can also make the conductive electrodes fully contact with the skin of the target user, ensuring that the contact impedance between the conductive electrodes and the skin changes as the tightness of wearing is minimized.

[0094] In addition, the conductive electrode of the flexible device is a composite conductive electrode composed of a site electrode and a thin film electrode. Among them, the site electrode is printed on the relatively soft surface of the flexible device, which can bring a comfortable wearing experience to the target user when collecting the EEG signal; the thin film electrode is located inside the flexible device, and the thin film electrode with a stretchable structure has a certain stretchability and the resistance will not change significantly. When the site electrode is placed on the surface of the flexible device by printing, the site electrode located on the surface of the flexible device is actually a conductive particle. When the site electrode is bent or stretched, the conductive particles inside it will separate to a certain extent. Therefore, by placing the thin film electrode under the site electrode and connecting it to the site electrode to form a composite conductive electrode, it can be achieved that when the target user wears the head wearable device, the flexible device is bent or stretched. When the resistance of the composite conductive electrode remains stable, it can obtain EEG signals more stably.

[0095] Next, the EEG detection method provided in the embodiment of the present application is explained in detail.

[0096] Fig.13 This is a flowchart of a method for detecting EEG signals based on the head wearable device provided in an embodiment of the present application, which is applied to the processing device. Fig.13 , the method comprises the following steps.

[0097] Step 1301: Apply voltage to the collection electrode and the reference electrode respectively.

[0098] Based on the above description, the sensing electrode group used to determine the EEG signal is a partial sensing electrode group among multiple sensing electrode groups. In this case, step 1301 may include the following steps (1)-(2).

[0099] (1) Selecting some sensing electrode groups from the plurality of sensing electrode groups as target sensing electrode groups.

[0100] In some embodiments, the angle of the flexible device is determined; based on the angle of the flexible device, a target sensing electrode group is determined from a target correspondence relationship, and the target correspondence relationship is used to record the correspondence between the angle information of the flexible device and the sensing electrode group used to determine the EEG signal, and when the angle of the flexible device is different, the sensing electrode group used to determine the EEG signal is different. In other words, the angle of the flexible device at the current moment is determined, and then based on the angle of the flexible device at the current moment, the corresponding sensing electrode group is determined from the target correspondence relationship, and then the determined sensing electrode group is used as the target sensing electrode group, that is, the sensing electrode group used to determine the EEG signal at the current moment.

[0101] The angle of the flexible device can be determined by at least one of the following sensors: an acceleration sensor, a gravity sensor, a direction sensor, and a rotation vector sensor. These sensors can convert physical characteristics such as acceleration when the flexible device moves into signals to detect changes in the angle of the flexible device. Of course, in practical applications, the angle of the flexible device can also be determined by other types of sensors, and the embodiments of the present application are not limited to this.

[0102] The above-mentioned target corresponding relationship can be obtained in the following manner, that is, for a target angle among multiple angles of the flexible device, when multiple test users wear the head wearable device according to the target angle, a brain induced signal of each test user among the multiple test users is obtained through a first sensing electrode group among the multiple sensing electrode groups to obtain multiple brain induced signals; based on the multiple brain induced signals, the EEG acquisition probability, the induction success probability, the correlation coefficient mean and the correlation coefficient standard deviation corresponding to the first sensing electrode group are determined; the first sensing electrode group is any one of the multiple sensing electrode groups, and after the EEG acquisition probability, the induction success probability, the correlation coefficient mean and the correlation coefficient standard deviation corresponding to other sensing electrode groups in the multiple sensing electrode groups are determined in the same manner as above, a sensing electrode group whose corresponding EEG acquisition probability is greater than the first probability threshold, the induction success probability is greater than the second probability threshold, the correlation coefficient mean is greater than the first coefficient threshold and the correlation coefficient standard deviation is less than the second coefficient threshold is selected from the multiple sensing electrode groups, and the selected sensing electrode group is determined as the sensing electrode group for acquiring EEG signals at the target angle. The target angle is any one of the multiple angles. After determining the sensing electrode groups used to obtain EEG signals at other angles among the multiple angles in the same manner as above, the sensing electrode groups used to obtain EEG signals at each angle among the multiple angles, that is, the target correspondence, can be obtained.

[0103] In some embodiments, the number of brain induced signals whose voltage amplitudes are within the voltage amplitude range of the electroencephalogram (EEG) signal among the multiple brain induced signals is determined to obtain a first number; the ratio between the first number and the total number of the multiple brain induced signals is determined as the electroencephalogram (EEG) acquisition probability corresponding to the first sensing electrode group; the number of brain induced signals whose voltage amplitudes are within the voltage amplitude range of the EEG signal and have a p300 wave among the multiple brain induced signals is determined to obtain a second number; the ratio between the second number and the total number of the multiple brain induced signals is determined as the induction success probability corresponding to the first sensing electrode group; based on the brain induced signals whose voltage amplitudes are within the voltage amplitude range of the EEG signal and have a p300 wave among the multiple brain induced signals, the mean correlation coefficient and the standard deviation of the correlation coefficient corresponding to the first sensing electrode group are determined by a Pearson correlation algorithm.

[0104] The multiple test users are randomly selected users, and the number of the multiple test users can be sufficient. The embodiment of the present application does not limit the number of the multiple test users.

[0105] The above-mentioned multiple brain-induced signals are detected and recorded when the EEG signals of these test users are induced. Since the voltage amplitude of the EEG signal is very small and has a certain voltage amplitude range, it is necessary to determine whether the voltage amplitude of the acquired brain-induced signal is within the voltage amplitude range of the EEG signal. If the voltage amplitude of a certain brain-induced signal is within the voltage amplitude range of the EEG signal, it means that the brain-induced signal may be an EEG signal. If the voltage amplitude of the brain-induced signal is not within the voltage amplitude range of the EEG signal, it means that the brain-induced signal is not an EEG signal, but may be interference from other physiological signals.

[0106] Because when the EEG signal of the test user is induced, the brain of the test user will generate an induced signal under external stimulation, which is called event-related potential. This event-related potential has its own specific waveform and potential distribution. One of them is that a positive wave will appear 300ms after the stimulation occurs, which is called p300 wave. P stands for Positive and represents the direction of the waveform. Therefore, it is also necessary to detect the p300 wave of the acquired brain induced signal. If the voltage amplitude of a brain induced signal is within the voltage amplitude range of the EEG signal and has a p300 wave, it means that the brain induced signal is successfully induced and the brain induced signal is an EEG signal. In other words, it is not certain whether it is an EEG signal only by whether the voltage amplitude of the brain induced signal is within the voltage amplitude range of the EEG signal. It is also necessary to detect whether the brain induced signal has a p300 wave to determine whether the brain induced signal is an EEG signal.

[0107] When determining the mean value and standard deviation of the correlation coefficient corresponding to the first sensing electrode group by the Pearson correlation algorithm, the brain induced signals with voltage amplitudes within the voltage amplitude range of the electroencephalogram signal and having a p300 wave among the multiple brain induced signals can be called multiple electroencephalogram signals, and the signal waveforms of the multiple electroencephalogram signals are respectively subjected to Pearson correlation operations with the calibration waveforms to obtain the correlation coefficient corresponding to each electroencephalogram signal, and the calibration waveform is the waveform obtained by the standard electroencephalogram signal detection medical equipment for electroencephalogram signal detection of the head area where the first sensing electrode group is located. All the correlation coefficients corresponding to the multiple electroencephalogram signals are averaged to obtain the mean value of the correlation coefficient corresponding to the first sensing electrode group, and the standard deviation of the correlation coefficient corresponding to the first sensing electrode group is determined based on this.

[0108] Among them, the first probability threshold, the second probability threshold, the first coefficient threshold and the second coefficient threshold are set in advance. In different situations, these thresholds can also be adjusted as needed, and the embodiments of the present application do not limit this. The above method is to select the sensing electrode group through these thresholds. In other embodiments, for a certain sensing electrode group, the greater the EEG acquisition probability corresponding to the sensing electrode group, the greater the probability of successful induction, the greater the mean of the correlation coefficient and the smaller the standard deviation of the correlation coefficient, it indicates that the head area where the sensing electrode group is located can more effectively acquire EEG signals. At this time, the sensing electrode group can be determined as the sensing electrode group for acquiring EEG signals at the target angle. At this time, the sensing electrode group can be selected according to the EEG acquisition probability, the probability of successful induction, the mean of the correlation coefficient and the standard deviation of the correlation coefficient corresponding to each sensing electrode group.

[0109] Next, two examples are used to introduce the selection method of the sensing electrode group for determining the EEG signal at a certain angle of the flexible device.

[0110] Example 1: Please refer to Figure 2 , assuming that the head wearable device is a headset, and the flexible device is an ear bag, the left ear bag of the headset has a ground electrode and six sensing electrode groups, the ground electrode is denoted as GND, and the six sensing electrode groups are denoted as C1, C2, C3, C4, C5 and C6 respectively. The positions of the head areas corresponding to the six sensing electrode groups can be referred to Figure 3; The right ear bag has six sensing electrode groups that are symmetrical with the sensing electrode groups of the left ear bag, and the six sensing electrode groups are respectively recorded as C7, C8, C9, C10, C11, and C12. 50 test users were randomly selected, and when the headphones were perpendicular to the heads of the test users, the EEG acquisition probability, induction success probability, correlation coefficient mean, and correlation coefficient standard deviation corresponding to each sensing electrode group were determined according to the above method. As shown in Table 1 below, Table 1 shows the EEG acquisition probability, induction success probability, correlation coefficient mean, and correlation coefficient standard deviation corresponding to each sensing electrode group of the left ear bag. The * in Table 1 indicates that no brain induced signal was detected.

[0111] Table 1

[0112] Sensing electrode group EEG acquisition probability Probability of induced success Mean correlation coefficient Correlation coefficient standard deviation C1 * * * * C2 28 / 50 13 / 50 0.8421 0.0473 C3 34 / 50 17 / 50 0.8597 0.0509 C4 26 / 50 11 / 50 0.7678 0.1262 C5 30 / 50 15 / 50 0.8585 0.0539 C6 20 / 50 1 / 50 0.9750 0

[0113] For each sensing electrode group, when the corresponding EEG acquisition probability is greater, the probability of successful induction is greater, the correlation coefficient mean is greater, and the correlation coefficient standard deviation is smaller, it indicates that the head region where the sensing electrode group is located can more effectively acquire EEG signals. Based on this theory, by comparing the data in Table 1, it can be obtained that: at a vertical angle, the head region where the three sensing electrode groups C2, C3 and C5 in the left ear bag are located can more effectively acquire EEG signals, and symmetrically, the head region where the three sensing electrode groups C8, C9 and C11 in the right ear bag are located can also more effectively acquire EEG signals. Therefore, the three sensing electrode groups C2, C3 and C5 in the left ear bag and the three sensing electrode groups C8, C9 and C11 in the right ear bag are determined as the sensing electrode groups used to acquire EEG signals at a vertical angle.

[0114] At different angles, the head area where each sensing electrode group is located will change, but the effective head area that can more effectively obtain EEG signals remains unchanged. Therefore, at different angles of the flexible device, the sensing electrode group located in the effective head area is obtained as the sensing electrode group for obtaining EEG signals, and then the different angles of the flexible device and the sensing electrode group used to obtain EEG signals at each angle are stored accordingly. In this way, effective EEG signals can be obtained through a limited number of sensing electrode groups at different angles of the flexible device, thereby improving the effectiveness of obtaining EEG signals.

[0115] Assume that each sensing electrode group includes a reference electrode and a collection electrode. Fig.14, assuming that the left ear bag has ten conductive electrodes, of which conductive electrode No. 6 is a grounding electrode, and the remaining conductive electrodes No. 1-5 and No. 7-10 are all sensing electrodes; the right ear bag and the left ear bag share a grounding electrode, so there are only nine conductive electrodes, and they are all sensing electrodes, of which conductive electrodes No. 11-15 are symmetrical with conductive electrodes No. 1-5 of the left ear bag, and conductive electrodes No. 16-19 are symmetrical with conductive electrodes No. 7-10 of the left ear bag. The corresponding relationship between different angles of the flexible device and the sensing electrode group used to determine the EEG signal is determined by the above method as shown in Table 2 below:

[0116] Table 2

[0117]

[0118] Example 2: Please refer to Figure 4 , assuming that the head wearable device is a smart eye mask, the flexible device is the eye mask piece inside the smart eye mask body, the right eye mask piece of the smart eye mask has a ground electrode and four sensing electrode groups, the ground electrode is recorded as GND, and the four sensing electrode groups are recorded as F1, F2, F3 and F4 respectively. The positions of the head areas corresponding to the four sensing electrode groups can be referred to Figure 5 The left eye mask has four sensing electrode groups symmetrically positioned with the sensing electrode groups of the right eye mask, and the four sensing electrode groups are respectively recorded as F5, F6, F7 and F8. 50 test users are randomly selected, and when the eye mask is perpendicular to the test user's head, the EEG acquisition probability, the probability of successful induction, the mean correlation coefficient and the standard deviation of the correlation coefficient corresponding to each sensing electrode group are determined according to the above method. It is determined by the obtained data that: at a vertical angle, the two sensing electrode groups F2 and F3 in the right eye mask and the two sensing electrode groups F6 and F7 in the left eye mask are the sensing electrode groups for acquiring EEG signals. In the same way, the target correspondence can be determined.

[0119] After determining the sensing electrode group used to determine the EEG signal, that is, the target sensing electrode group, in the above manner, if the target sensing electrode group is not switched when the angle changes, some sensing electrode groups will not be located in the area of ​​the head where the EEG signal can be effectively acquired. Since only some sensing electrode groups are used for signal acquisition when detecting the EEG signal of the target user, while other sensing electrode groups are in an inactive state, some sensing electrode groups in the target sensing electrode group cannot effectively acquire the EEG signal, thereby reducing the effectiveness of EEG signal acquisition. After obtaining the target correspondence in the above manner, the target sensing electrode group is switched at different angles of the flexible device, and different sensing electrode groups are selected to detect EEG signals. Compared with a fixed sensing electrode group, this can compensate to a certain extent for the reduction in the effectiveness of EEG signal acquisition caused by the angle offset.

[0120] The following is further verification of the above conclusion:

[0121] Continuing with Example 1, please refer to Fig.15 , Fig.15 The schematic diagrams showing the locations of the target sensing electrode groups in three cases are shown. Fig.15 The left figure is a schematic diagram of the position of the target sensing electrode group when the left ear bag is perpendicular to the head. At this time, the target sensing electrode group is located in the area of ​​the head where the EEG signal can be effectively obtained. This situation is recorded as situation 1; Fig.15 The middle figure is a schematic diagram of the target sensing electrode group unchanged when the left ear bag changes from being perpendicular to the head to being tilted forward. At this time, the position of the target sensing electrode group and the area of ​​the head that can effectively obtain EEG signals are offset. This situation is recorded as situation 2; Fig.15 The right picture is a schematic diagram of the left earmuff changing from perpendicular to the head to tilted forward but switching the target sensing electrode group. At this time, the target sensing electrode group is relocated to the area of ​​the head where the EEG signal can be effectively obtained. This situation is recorded as situation 3. Fig.15 In the figure, 1 represents the collection electrode, 2 represents the reference electrode, and 3 represents the ground electrode.

[0122] Three test users were randomly selected, and EEG was induced on these three test users under the above three conditions, and the correlation coefficients of the EEG signals collected by each sensing electrode group were determined as shown in Table 3. C2, C3, and C5 are the effective head areas around the left ear, and C8, C9, and C11 are the effective head areas around the right ear. * indicates that the p300 wave was not detected, that is, the EEG signal was not obtained.

[0123] Table 3

[0124]

[0125]

[0126] Analysis of the data in Table 3 shows that, compared with not switching the target sensing electrode group, switching the target sensing electrode group according to the target correspondence can compensate to a certain extent for the reduction in the effectiveness of EEG signal acquisition caused by the angle offset. This also verifies again that only some areas of the head can effectively obtain EEG signals, and also explains the rationality of selecting only some sensing electrodes for detecting EEG signals.

[0127] (2) Apply voltage to the collection electrode and reference electrode in the target sensing electrode group.

[0128] Except for the target sensing electrode group, the other sensing electrode groups are in an inactive state, and no voltage may be applied. Of course, voltage may be applied but data may not be collected, or voltage may be applied and data may be collected but no subsequent data processing may be performed.

[0129] In some embodiments, before applying voltage to the collection electrode and the reference electrode, it can also be determined whether the target user is wearing a flexible device. If the target user is wearing a flexible device, the step of applying voltage to the collection electrode and the reference electrode is performed; if the target user is not wearing a flexible device, the step of applying voltage to the collection electrode and the reference electrode is not performed.

[0130] In some embodiments, if the target user does not wear the flexible device within the first specified time after the head wearable device is turned on, the head wearable device automatically shuts down to avoid wasting power. The first specified time is set in advance, for example, the first specified time is 30s, and it can be adjusted to a suitable time according to different application scenarios. This embodiment of the present application does not limit this.

[0131] Since not all areas of the human head can effectively obtain EEG signals, it is only necessary to use the sensing electrode group located in the head area where effective EEG signals can be obtained to collect EEG signals. In this way, only a limited number of signals can be processed each time the EEG signal is detected, without processing all the signals, so that the system complexity is reduced and the signal processing process is faster. In addition, since the angle of the flexible device will inevitably change in actual applications, if only part of the sensing electrode group is fixed as the sensing electrode group used to determine the EEG signal, it may not be possible to obtain effective EEG signals at certain angles. Therefore, according to the corresponding relationship between the angle information of the flexible device and the sensing electrode group used to determine the EEG signal, a suitable sensing electrode group can be selected each time the detection is performed, so that effective EEG signals can be obtained through a limited number of sensing electrode groups at different angles.

[0132] Step 1302: Obtain the voltage difference between the contact voltages of the collection electrode and the reference electrode in the same sensing electrode group and the head of the target user.

[0133] Since contact impedance is generated when the sensing electrode contacts the skin, when voltage is applied to the surface of the sensing electrode to form a loop, the contact voltage between the collection electrode and the skin and the contact voltage between the reference electrode and the skin can be obtained, and then the voltage difference between the two contact voltages can be obtained.

[0134] Step 1303: Determine the EEG signal of the target user based on the voltage difference.

[0135] Since the EEG signal is quite weak, its voltage amplitude range is generally only 2μv-200μv. Therefore, after obtaining the voltage difference, the obtained voltage difference can be amplified. The amplification process can facilitate subsequent further observation and other analysis and processing of the EEG signal.

[0136] In the embodiment of the present application, by applying voltage to the collection electrodes and reference electrodes in some sensing electrode groups to collect the EEG signals of the target user, the processing device only needs to process a limited number of signal data, making the processing process faster and reducing the complexity of the system; at the same time, since the angle of the flexible device may be offset in actual applications, if a fixed sensing electrode group is used as the target sensing electrode group for determining the EEG signal, the target sensing electrode group will be offset from the effective head area where the EEG signal can be obtained. Therefore, by determining the corresponding relationship between the angle information of the flexible device and the sensing electrode group located in the effective head area, different sensing electrode groups are selected at different angles of the flexible device to collect EEG signals. In this way, effective EEG signals can be obtained through a limited number of sensing electrode groups at different angles of the flexible device. In addition, in the embodiment of the present application, when the target user wears the flexible device, the step of applying voltage to the collection electrode and the reference electrode is performed, thereby avoiding the waste of electricity and thus avoiding the ineffective consumption of system resources.

[0137] Fig.16 is a schematic diagram of the structure of an electroencephalogram detection device provided in an embodiment of the present application. The electroencephalogram detection device can be implemented by software, hardware, or a combination of both to become part or all of a head-worn device. The head-worn device can be Figure 2 Headphones or Figure 4 The smart eye mask shown or Fig.12 Wearable medical monitor shown. Fig.16 The device includes: an applying module 1601, an acquiring module 1602 and a determining module 1603.

[0138] An application module 1601, used to apply voltage to the collection electrode and the reference electrode respectively;

[0139] An acquisition module 1602 is used to acquire a voltage difference between a collection electrode and a reference electrode in the same sensing electrode group and a contact voltage with the head of a target user;

[0140] The determination module 1603 is used to determine the EEG signal of the target user based on the voltage difference.

[0141] Optionally, the applying module 1601 includes:

[0142] A selection submodule, used for selecting some sensing electrode groups from the plurality of sensing electrode groups as target sensing electrode groups;

[0143] The first applying submodule is used to apply voltage to the collection electrode and the reference electrode in the target sensing electrode group.

[0144] Optionally, the selection submodule includes:

[0145] A first determining unit, configured to determine an angle of the flexible device;

[0146] The second determination unit is used to determine the target sensing electrode group from the target correspondence based on the angle of the flexible device. The target correspondence is used to record the correspondence between the angle information of the flexible device and the sensing electrode group used to determine the electroencephalogram signal. When the angle of the flexible device is different, the sensing electrode group used to determine the electroencephalogram signal is different.

[0147] Optionally, the device further comprises:

[0148] The trigger module is used to trigger the application module 1601 to apply voltage to the collection electrode and the reference electrode when the target user wears the flexible device.

[0149] In an embodiment of the present application, voltage is applied to the collection electrodes and reference electrodes in some sensing electrode groups to collect the EEG signals of the target user, so that the processing device only needs to process a limited amount of signal data, which makes the processing process faster and reduces the complexity of the system; at the same time, since the angle of the flexible device may be offset in actual applications, if a fixed sensing electrode group is used as the target sensing electrode group for determining the EEG signal, the target sensing electrode group and the effective head area where the EEG signal can be obtained will be offset. Therefore, by determining the correspondence between the angle information of the flexible device and the sensing electrode group located in the effective head area, different sensing electrode groups are selected at different angles of the flexible device to collect EEG signals. In this way, effective EEG signals can be obtained through a limited number of sensing electrode groups at different angles of the flexible device.

[0150] It should be noted that: the EEG detection device provided in the above embodiment only uses the division of the above functional modules as an example when detecting EEG signals. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. In addition, the EEG detection device provided in the above embodiment belongs to the same concept as the EEG detection method embodiment. The specific implementation process is detailed in the method embodiment and will not be repeated here.

[0151] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) mode to another website site, computer, server or data center. The computer-readable storage medium can be any available medium that a computer can access, or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a digital versatile disc (DVD)), or a semiconductor medium (e.g., a solid state disk (SSD)). It is worth noting that the computer-readable storage medium mentioned in the embodiment of the present application may be a non-volatile storage medium, in other words, a non-transient storage medium.

[0152] It should be understood that the "multiple" mentioned herein refers to two or more. In the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in order to facilitate the clear description of the technical solution of the embodiments of the present application, in the embodiments of the present application, the words "first", "second" and the like are used to distinguish between the same items or similar items with basically the same functions and effects. Those skilled in the art can understand that the words "first", "second" and the like do not limit the quantity and execution order, and the words "first", "second" and the like do not limit them to be necessarily different.

[0153] It should be noted that the information (including but not limited to user device information, user personal information, etc.), data (including but not limited to data used for analysis, stored data, displayed data, etc.) and signals involved in the embodiments of the present application are all authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data need to comply with relevant laws, regulations and standards of relevant countries and regions.

Claims

1. A head wearable device, characterized in that: The head-worn device comprises a flexible device and a processing device; The flexible device has a plurality of conductive electrodes electrically connected to the processing device, and the plurality of conductive electrodes are distributed in the flexible device and arranged in a ring shape; The plurality of conductive electrodes include a ground electrode and a plurality of sensing electrode groups, each sensing electrode group includes at least two sensing electrodes located adjacent to each other, one of the at least two sensing electrodes is used as a reference electrode, and the others are used as collection electrodes; The processing device is used to apply voltage to the collection electrode and the reference electrode respectively, and obtain the EEG signal of the target user based on the collection electrode and the reference electrode in the same sensing electrode group.

2. The head-mounted device according to claim 1, characterized in that: The sensing electrode groups used to determine the brain electrical signal are part of the sensing electrode groups among the plurality of sensing electrode groups.

3. The head-mounted device according to claim 2, wherein: The angle information of the flexible device corresponds to the sensing electrode group used to determine the brain electrical signal, and when the angle of the flexible device is different, the sensing electrode group used to determine the brain electrical signal is different.

4. The head-mounted device according to claim 1, wherein: The conductive electrode is in a long strip structure, and the long sides of the conductive electrode are distributed along the circumference of the ring.

5. The head-mounted device according to claim 1, wherein: The conductive electrodes include a site electrode located on the surface of the flexible device and a film electrode located inside the flexible device, and the site electrode and the film electrode are connected via a conductive adhesive.

6. The head-mounted device according to claim 5, characterized in that: The thin film electrode is a stretchable structure.

7. The head-mounted device according to claim 5 or 6, characterized in that: The thin film electrode comprises a flexible thin film substrate and a metal coating located on the surface of the flexible thin film substrate.

8. The head-worn device according to any one of claims 1 to 7, characterized in that: The head-mounted device is a headset, the flexible device is an earmuff, and the head-mounted device also includes a connector having a symmetrical first connecting end and a second connecting end, and each of the first connecting end and the second connecting end is connected to one of the flexible devices.

9. A method for detecting electroencephalogram signals based on the head-worn device according to any one of claims 1 to 8, characterized in that: Applied to the processing device, the method comprises: applying voltages to the collection electrode and the reference electrode respectively; Acquire the voltage difference between the contact voltages of the collection electrode and the reference electrode in the same sensing electrode group and the head of the target user; An electroencephalogram signal of the target user is determined based on the voltage difference.

10. The method according to claim 9, characterized in that The step of applying voltage to the collection electrode and the reference electrode respectively comprises: selecting a portion of the sensing electrode groups from the plurality of sensing electrode groups as target sensing electrode groups; A voltage is applied to the collection electrode and the reference electrode in the target sensing electrode group.

11. The method according to claim 10, characterized in that The selecting a part of the sensing electrode groups from the plurality of sensing electrode groups as target sensing electrode groups comprises: determining an angle of the flexible device; Based on the angle of the flexible device, the target sensing electrode group is determined from the target correspondence, and the target correspondence is used to record the correspondence between the angle information of the flexible device and the sensing electrode group used to determine the electroencephalogram signal, and when the angle of the flexible device is different, the sensing electrode group used to determine the electroencephalogram signal is different.

12. The method according to any one of claims 9 to 11, characterized in that: Before applying voltage to the collection electrode and the reference electrode, the method further comprises: In a case where the target user wears the flexible device, a step of applying voltage to the collection electrode and the reference electrode is performed.

13. An electroencephalogram signal detection device, characterized in that: Included in a head-worn device, the device comprises: An application module, used for applying voltage to the collection electrode and the reference electrode respectively; An acquisition module, used to acquire the voltage difference between the contact voltages of the collection electrode and the reference electrode in the same sensing electrode group and the head of the target user; A determination module is used to determine the EEG signal of the target user based on the voltage difference.

14. A computer-readable storage medium, characterized in that: The storage medium stores instructions, and when the instructions are executed on the computer, the computer executes the steps of the method according to any one of claims 9 to 12.

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