Method and system for establishing common reference for BIO-signals in wireless systems

Abstract

A method includes detecting, at a charging case associated with the wireless earbuds, an insertion of a right wireless earbud and a left wireless earbud into the charging case. The method includes measuring a voltage deviation of the right wireless earbud and the left wireless earbud when each of the wireless earbuds is not electrically connected to the charging case in response to detecting the insertion of the right wireless earbud and the left wireless earbud into the charging case. The method includes establishing a synchronized reference potential between the right wireless earbud and the left wireless earbud based on the measured voltage deviation, to ensure synchronization between both wireless earbuds. The method includes storing the synchronized reference potential in a voltage stabilizing module of each of the wireless earbuds, to provide a stable electrical reference for wireless acquisition of biosignals comprising Electroencephalography (EEG) signals.

Description

METHOD AND SYSTEM FOR ESTABLISHING COMMON REFERENCE FOR BIO- SIGNALS IN WIRELESS SYSTEMS FIELD OF THE INVENTION

[0001] The present invention generally relates to the field of bio-signal measuring devices (e.g., Electroencephalogram (EEG)), and more specifically relates to a method and a system for establishing common reference for bio-signals in wireless systems. BACKGROUND

[0002] The information disclosed in this background section is only for the enhancement of understanding of the general background of the disclosure and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

[0003] An electroencephalogram (EEG) serves as a diagnostic tool that measures and records the brain’s electrical activity, holding significant potential for monitoring and diagnosing various disorders, including epilepsy and sleep-related conditions. Developing a user-friendly EEG device is essential to ensure ease of interaction and minimal discomfort, particularly during extended usage periods. However, a persistent challenge in EEG technology involves identifying an appropriate reference point, leading to inconsistent practices. There is a growing global trend towards adopting wireless ear-worn devices (e.g., wireless earbuds) that incorporate bio-signal sensors, prioritizing user comfort, especially during long-term monitoring and overnight use, and enhancing user’s experience. However, several problems are encountered in the existing methods or applications, or wireless ear-worn devices, which are mentioned below.

[0004] When measuring ear electroencephalograms (Ear-EEGs), a compact design of the wireless ear-worn device complicates a selection of suitable sites for reference voltage measurement. A common practice involves placing a reference electrode close to a recording electrode, but this proximity can introduce substantial interference, potentially obscuring the bio- signals being recorded. To mitigate interference, positioning reference electrodes on opposite sides of an ear can enhance a quality of bio-signal data collection. Despite the effectiveness of this method, it typically requires wires, which detracts from achieving a modern design and increases complexity and cost. Additionally, wireless earbuds encounter difficulties in establishing and maintaining a common reference point necessary for optimal performance, especially without theaid of wires, presenting a challenge for the advancement of user-friendly and effective EEG monitoring solutions.

[0005] Thus, it is desired to address the above-mentioned disadvantages or other shortcomings or at least provide a useful alternative for establishing the common reference point for bio-signals in wireless systems. SUMMARY

[0006] This summary is provided to introduce a selection of concepts, in a simplified format, that are further described in the detailed description of the invention. This summary is neither intended to identify key or essential inventive concepts of the invention nor is it intended for determining the scope of the invention.

[0007] According to one embodiment of the present disclosure, a method for managing a wireless earbud is disclosed herein. The method includes detecting, at a charging case associated with the wireless earbuds, an insertion of a right wireless earbud and a left wireless earbud into the charging case. The method further includes measuring, using a controller of the charging case, a voltage deviation of the right wireless earbud and the left wireless earbud when each of the wireless earbuds is not electrically connected to the charging case in response to detecting the insertion of the right wireless earbud and the left wireless earbud into the charging case. The method further includes establishing, by the controller, a synchronized reference potential between the right wireless earbud and the left wireless earbud based on the measured voltage deviation, to ensure synchronization between both wireless earbuds. The method further includes storing, by the controller, the synchronized reference potential in a voltage stabilizing module of each of the wireless earbuds, to provide a stable electrical reference for wireless acquisition of biosignals comprising Electroencephalography (EEG) signals.

[0008] According to one embodiment of the present disclosure, a method for managing a wireless earbud. The method includes detecting, by a biosignal data acquisition module of the wireless earbud, at least one event associated with a user of the wireless earbuds while recording one or more EEG signals from a brain of the user. The method further includes segmenting, by a biosignal processor module of the wireless earbud, the one or more recorded EEG signals into one or more epochs relative to the at least one detected event. The method further includes extracting one or more Event Related Potential (ERP) features to establish a personalized neural baseline for the user in response to segmenting. The method further includes adjusting, by the biosignalprocessor module, one or more EEG signal processing parameters within the wireless earbuds to match the established personalized neural baseline.

[0009] According to one embodiment of the present disclosure, a method for managing a wireless earbud. The method includes employing a detachable conductive pathway through a quick fitting mechanism comprising at least one of a magnetic coupling and a snap fit, to establish an electrical connection between the right and left wireless earbuds. The conductive pathway electrically connects at least one electrode of one wireless earbud to a biosignal acquisition module of the other wireless earbud for contralateral referencing. The conductive pathway couples reference electrodes of both earbuds to form a unified reference potential. The conductive pathway comprises a flexible insulated conductor and an auxiliary power source integrated to extend battery life and enhance mechanical anchoring.

[0010] According to another embodiment of the present disclosure, a system for managing a wireless earbud is disclosed herein. The system comprises a charging case operably connected to the wireless earbud. The system is configured to detect, at a charging case associated with the wireless earbuds, an insertion of a right wireless earbud and a left wireless earbud into the charging case. The system configured to measure, using a controller of the charging case, a voltage deviation of the right wireless earbud and the left wireless earbud when each of the wireless earbuds is not electrically connected to the charging case in response to detecting the insertion of the right wireless earbud and the left wireless earbud into the charging case. The system is configured to establish, by the controller, a synchronized reference potential between the right wireless earbud and the left wireless earbud based on the measured voltage deviation, to ensure synchronization between both wireless earbuds. The system is configured to store, by the controller, the synchronized reference potential in a voltage stabilizing module of each of the wireless earbuds, to provide a stable electrical reference for wireless acquisition of biosignals comprising Electroencephalography (EEG) signals.

[0011] According to one embodiment of the present disclosure, a system for managing a wireless earbud. The system comprises a charging case operably connected to the wireless earbud. The system is configured to detect, by a biosignal data acquisition module of the wireless earbud, at least one event associated with a user of the wireless earbuds while recording one or more EEG signals from a brain of the user. The system is configured to segment, by a biosignal processor module of the wireless earbud, the one or more recorded EEG signals into one or more epochs relative to the at least one detected event. The system is configured to extract one or more Event Related Potential (ERP) features to establish a personalized neural baseline for the user in responseto segmenting. The system is configured to adjust, by the biosignal processor module, one or more EEG signal processing parameters within the wireless earbuds to match the established personalized neural baseline.

[0012] According to one embodiment of the present disclosure, a system for managing a wireless earbud. The system comprises a charging case operably connected to the wireless earbud. The system is configured to employ a detachable conductive pathway through a quick fitting mechanism comprising at least one of a magnetic coupling and a snap fit, to establish an electrical connection between the right and left wireless earbuds. The conductive pathway electrically connects at least one electrode of one wireless earbud to a biosignal acquisition module of the other wireless earbud for contralateral referencing. The conductive pathway couples reference electrodes of both earbuds to form a unified reference potential. The conductive pathway comprises a flexible insulated conductor and an auxiliary power source integrated to extend battery life and enhance mechanical anchoring. The conductive pathway can be coiled up inside the charging case when not in use.

[0013] To further clarify the advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which are illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail in the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

[0015] FIG. 1 is a diagram of an example of an implementation environment in which systems and / or methods, described herein, may be implemented, according to an embodiment as disclosed herein;

[0016] FIG. 2 illustrates a block diagram of a charging case for establishing a common reference for one or more bio-signals, according to an embodiment as disclosed herein;

[0017] FIG.3 illustrates a block diagram of a wireless earbud for establishing the common reference for the one or more bio-signals, according to an embodiment as disclosed herein;

[0018] FIG. 4 is a flow diagram illustrating a method for providing a stable electrical reference while both wireless earbuds are placed into the charging case, according to an embodiment as disclosed herein;

[0019] FIG.5 is a flow diagram illustrating a method for adjusting one or more EEG signal processing parameters within the wireless earbuds to match an established personalized neural baseline, according to an embodiment as disclosed herein; and

[0020] FIG. 6 is a flow diagram illustrating a method for employing a detachable conductive pathway through a quick fitting mechanism, according to an embodiment as disclosed herein.

[0021] Further, skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have necessarily been drawn to scale. For example, the flow charts illustrate the method in terms of the most prominent steps involved to help to improve understanding of aspects of the present invention. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. DETAILED DESCRIPTION OF FIGURES

[0022] For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

[0023] It will be understood by those skilled in the art that the foregoing general description and the following detailed description are explanatory of the invention and are not intended to be restrictive thereof.

[0024] Reference throughout this specification to “an aspect”, “another aspect” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrase “in an embodiment”, “in one embodiment”, “in another embodiment”, and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

[0025] The terms “comprise”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or sub-systems or elements or structures or components proceeded by “comprises... a” does not, without more constraints, preclude the existence of other devices or other sub-systems or other elements or other structures or other components or additional devices or additional sub-systems or additional elements or additional structures or additional components.

[0026] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. Also, the various embodiments described herein are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments. The term “or” as used herein, refers to a non-exclusive or unless otherwise indicated. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein can be practiced and to further enable those skilled in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

[0027] As is traditional in the field, embodiments may be described and illustrated in terms of blocks that carry out a described function or functions. These blocks, which may be referred to herein as units or modules or the like, are physically implemented by analog or digital circuits such as logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive electronic components, active electronic components, optical components, hardwired circuits, or the like, and may optionally be driven by firmware and software. The circuits may, for example, be embodied in one or more semiconductor chips, or on substrate supports such as printed circuit boards and the like. The circuits constituting a block may be implemented bydedicated hardware, or by a processor (e.g., one or more programmed microprocessors and associated circuitry), or by a combination of dedicated hardware to perform some functions of the block and a processor to perform other functions of the block. Each block of the embodiments may be physically separated into two or more interacting and discrete blocks without departing from the scope of the invention. Likewise, the blocks of the embodiments may be physically combined into more complex blocks without departing from the scope of the invention.

[0028] The accompanying drawings are used to help easily understand various technical features, and it should be understood that the embodiments presented herein are not limited by the accompanying drawings. As such, the present disclosure should be construed to extend to any alterations, equivalents, and substitutes in addition to those which are particularly set out in the accompanying drawings. Although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are generally only used to distinguish one element from another.

[0029] Referring now to the drawings, and more particularly to FIGS.1 to 6, where similar reference characters denote corresponding features consistently throughout the figures, the preferred embodiments are shown.

[0030] FIG. 1 is a diagram of an example of an implementation environment in which systems and / or methods, described herein, may be implemented, according to an embodiment as disclosed herein. The system 1000 includes a charging case 100 and wireless earbuds 200. The wireless earbud 200 includes a right wireless earbud 200a and a left wireless earbud 200b. The system 1000 may execute multiple operations to establish a common reference for biosignals and / or to manage the wireless earbud 200, which are given below.

[0031] In some example embodiments, the system 1000 is configured to detect, at the charging case 100 associated with the wireless earbuds 200, an insertion of the right wireless earbud 200a and the left wireless earbud 200b into the charging case 100. In response to detecting the insertion of the right wireless earbud 200a and the left wireless earbud 200b into the charging case 100, the system 1000 is configured to measure, using a controller of the charging case 100 (not shown in FIG. 1), a voltage deviation of each of the wireless earbuds 200 when each of the wireless earbuds 200 is not electrically connected to the charging case 100. The system 1000 is further configured to establish, by the controller, a synchronized reference potential between the right wireless earbud 200a and the left wireless earbud 200b based on the measured voltage deviation, to ensure synchronization between both wireless earbuds 200. The system 1000 is further configured to store, by the controller, the synchronized reference potential in a voltagestabilizing module of each of the wireless earbuds 200, to provide a stable electrical reference for wireless acquisition of biosignals may include, for example, but is not limited to, Electroencephalography(EEG) signals.

[0032] In some example embodiments, to establish the synchronized reference potential between the right wireless earbud 200a and the left wireless earbud 200b based on the measured voltage deviation, the system 1000 may execute multiple operations, for instance, recording a voltage level of each of the wireless earbuds 200 before inserting each of the wireless earbuds 200 into the charging case 100 to establish a baseline, and determining a difference between the recorded voltage level and the baseline to establish the common potential difference.

[0033] In some example embodiments, in response to detecting that each of the wireless earbuds 200 is not electrically connected to the charging case 100, the wireless earbud may execute multiple operations to establish the common reference for the biosignals and / or to manage the wireless earbuds 200, which are given below.

[0034] In some example embodiments, each of the wireless earbuds 200 maintains the synchronization of the reference potentials in the voltage stabilizing module.

[0035] In some example embodiments, each of the wireless earbuds 200 counteracts one or more external voltage variations using the voltage stabilizing module to maintain an integrity of the synchronized reference potential during use.

[0036] In some example embodiments, each of the wireless earbuds 200 continually monitors and resynchronizes the reference potential during collections of one or more Electroencephalography (EEG) signals to ensure that each of the wireless earbuds 200 operates with the established common reference potential.

[0037] In some example embodiments, a charge storage module (not shown in FIG. 1) of each of the wireless earbuds 200 provides an isolated power to a biosignal circuitry through charge storage components, thereby preventing noise interference from a main battery (not shown in FIG. 1).

[0038] In some example embodiments, in response to detecting that both wireless earbuds 200 are placed into the charging case 100, the system 1000 is configured to measure, by the controller, deviations from the common reference due to usage when the earbuds are returned to the charging case 100. The system 1000 is further configured to determine whether the measured deviations are above or below a baseline, to improve a reference model for future operations. The system 1000 is further configured to dynamically measure, based on a relative re-referencing mechanism, voltage deviations between an electrode of the left wireless earbud 200b, an electrodeof the right wireless earbud 200a, and a ground of the charging case 100. The system 1000 is further configured to compensate for voltage drift to ensure consistent signal acquisition across earbuds.

[0039] For instance, consider a scenario where a user frequently uses the wireless earbuds 200 for enjoying music and monitoring brain activity through EEG signals. When the user places both the right and left earbuds 200 into the charging case 100, the charging case 100 recognizes their insertion. In response, the controller within the charging case 100 measures the voltage deviations of each wireless earbud 200 while they are disconnected from the charging case 100. This measurement is essential for establishing the synchronized reference potential, ensuring harmonious operation between the two earbuds. Once the reference potential is established, the reference potential gets stored in the voltage stabilizing module located in each wireless earbud 200. This voltage stabilizing module is crucial as it provides the stable electrical reference for acquiring EEG signals during use. Even when disconnected from the charging case 100, the earbuds maintain this synchronization, counteracting any external voltage variations to uphold the integrity of the reference potential. As the user continues to utilize the wireless earbuds 200, the wireless earbuds 200 actively monitor and resynchronize the reference potential while collecting EEG signals, ensuring consistent performance. Furthermore, when the wireless earbuds 200 are placed back into the charging case 100, the controller evaluates any deviations from the established reference caused by usage. It determines whether these deviations exceed a predetermined baseline, which assists in refining the reference model for future operations. The system dynamically measures voltage deviations between the electrodes of both earbuds and the ground of the charging case 100, compensating for any voltage drift to guarantee reliable and consistent signal acquisition across both devices. This advanced management significantly enhances the user experience by delivering high-quality audio and accurate biosignal monitoring.

[0040] In some example embodiments, the system 1000 is configured to detect, by a biosignal data acquisition module (not shown in FIG.1) of the wireless earbud, at least one event associated with a user of the wireless earbuds 200 while recording one or more EEG signals from a brain of the user. The at least one event may include, for example, but is not limited to, one or more auditory cues (e.g., tones), one or more visual cues (e.g., light patterns), and one or more cognitive tasks (e.g., Mental arithmetic, mental singing, eyes-open / eyes-closed transition). The recording of one or more Electroencephalography (EEG) signals is time-locked to an onset of the at least one event to ensure precise alignment of EEG data with the at least one event.

[0041] In some example embodiments, the system 1000 is further configured to segment, by a biosignal processor module (not shown in FIG. 1) of the wireless earbud, the one or more recorded EEG signals into one or more epochs relative to the at least one detected event. The system 1000 is further configured to extract one or more Event Related Potential (ERP) features (e.g., peak amplitudes, latency of peaks, and waveform morphology) to establish a personalized neural baseline for the user in response to segmenting. The system 1000 is further configured to adjust, by the biosignal processor module, one or more EEG signal processing parameters within the wireless earbuds 200 to match the established personalized neural baseline.

[0042] In some example embodiments, the system 1000 is configured to average one or more EEG responses across multiple trials of the at least one detected event to enhance the one or more ERP features by reducing a background noise.

[0043] In some example embodiments, the system 1000 is configured to extract one or more morphological features of one or more electrocardiography (ECG) signals of the user instead of the one or more ERP features in the one or more EEG signals to establish a common biosignal baseline between the two earbuds for the user. The one or more morphological features of the one or more ECG signals comprising at least one of peak amplitude, segment width, segment intervals, and waveform shape. The system 1000 is configured to adjust, by the biosignal processor module, one or more EEG signal processing parameters within the wireless earbuds 200 to match the established biosignal baseline.

[0044] In some example embodiments, the system 1000 is configured to identify one or more non-neural artifacts in the one or more recorded EEG signals based on the one or more ERP features to compare real-time EEG data against the personalized neural baseline for the user. In other words, the system 1000 is configured to identify one or more deviations in the one or more recorded EEG signals that exhibit one or more unnatural amplitudes or timing (e.g., such as sudden spikes occurring during eye blinks or muscle movements). The system 1000 is configured to reconstruct a clean EEG signal that retains neural activity while effectively removing the one or more identified non-neural artifacts. The cleaned EEG data is used for subsequent analysis, ensuring that one or more neural responses are accurately represented without interference from the one or more identified non-neural artifacts.

[0045] In some example embodiments, the system 1000 is configured to isolate the one or more identified non-neural artifacts by subtracting a user clean ERP template, derived from the established personalized neural baseline, from one or more contaminated EEG signals.

[0046] In some example embodiments, the system 1000 is configured to employ a detachable conductive pathway through a quick fitting mechanism comprising at least one of a magnetic coupling and a snap fit, to establish an electrical connection between the right and left wireless earbuds 200. The conductive pathway electrically connects at least one electrode of one wireless earbud to a biosignal acquisition module (not shown in FIG. 1) of the other wireless earbud for contralateral referencing. The conductive pathway couples reference electrodes of both earbuds to form a unified reference potential. The conductive pathway comprises a flexible insulated conductor 201 and an auxiliary power source 202 integrated to extend battery life and enhance mechanical anchoring. The conductive pathway can be coiled up inside the charging case 100 when not in use.

[0047] For instance, consider a scenario where a user engages in fitness activities while utilizing wireless earbuds 200 designed for optimal performance. These wireless earbuds 200 feature a quick fitting mechanism that employs a magnetic coupling to establish an electrical connection between the right and left wireless earbuds 200. When the user places the earbuds together, the magnetic coupling activates, creating a detachable conductive pathway. This pathway connects the electrodes of one earbud to the biosignal acquisition module in the other earbud, enabling contralateral referencing. As a result, both wireless earbuds 200 can share reference electrodes, forming a unified reference potential that enhances the accuracy of biosignal monitoring during workouts. The conductive pathway includes a flexible insulated conductor 201, which ensures a reliable electrical connection and integrates an auxiliary power source 202. This feature may extend battery life and provide mechanical anchoring, allowing the user to move freely without concerns about disconnection or power loss.

[0048] In some example embodiments, the system 1000 is configured to establish an electrical coupling between the right and left wireless earbuds 200 via a biological tissue of the user without a physical conductor. The at least one electrode on each of the wireless earbuds 200 maintains contact with one or more skin locations of the user, comprising a mastoid, a conchae, a mandibular region, and a neck. Contralateral referencing or a common reference potential is achieved through one or more resistive and capacitive coupling properties of a skin of the user. Geometry, material, and mechanical design of the at least one electrode is optimized to ensure stable, low-impedance contact during use.

[0049] For instance, consider a scenario where a user employs advanced wireless earbuds 200 equipped with technology that allows for electrical coupling through biological tissue. Each wireless earbud 200 has electrodes that maintain contact with specific skin locations on the user’sbody, such as the mastoid behind the ear and the mandibular region of the jaw. When the user wears the wireless earbuds 200, the electrodes establish the connection with the skin, utilizing the resistive and capacitive coupling properties of the tissue to achieve contralateral referencing. As a result, the wireless earbuds 200 can effectively share the common reference potential without needing the physical conductor. The design of the electrodes is optimized for stable, low- impedance contact, ensuring that the connection remains reliable during use. As the user moves around, the wireless earbud continuously monitors brain activity, providing accurate data without the constraints of wires or direct electrical connection.

[0050] In some example embodiments, when the wireless earbuds 200 are placed back into the charging case 100, the controller quantifies any deviation from the common ground level that the wireless earbuds 200 may have experienced. These deviations, whether higher or lower, offer valuable insights into the intricate relationships among the charging case 100, the left wireless earbud 200b, and the right wireless earbud 200a, contributing to an enhanced understanding of the system's operation and helping set up the common reference potential.

[0051] In some example embodiments, an intelligent set of charge storage modules (B2) but not limited to batteries and capacitors, are incorporated into each earbud system 1000 along with the already existing batteries in the earbuds (D2) that power the usual operation of speakers, wireless radios, noise cancellation etc. within the system 1000. These charge storage units (B2) serve as a source to power the sensitive biosignal data acquisition as well as the voltage stabilizing modules (not shown in FIG.1).

[0052] In some example embodiments, each of the wireless earbuds 200 is equipped with a calibration module (B3) (not shown in FIG. 1)capable of storing and discharging a limited amount of charge to any connected system. During a biosignal sensing operation, such as before or after a test, this module is linked to the fully configured electrode system for biosignal measurement. It measures the charge transferred at that moment, and this specific value serves as a fine-tuning calibration reference to establish a common point of reference between the wireless systems.

[0053] In some example embodiments, a common power source is employed to recharge the battery located within the Earbud charging case (B1). Consequently, this battery evenly charges all other charge-storing modules (not shown in FIG. 1), providing them with identical characteristics. The use of a common power source guarantees synchronization across all charge modules and components within the electrical system until they are taken out of the charging case 100.

[0054] In some example embodiments, the system 1000 employs relative re-referencing to quantify and establish connections among the left wireless earbud 200b, the right wireless earbud 200a, and the charging case 100, enabling the measurement of deviations from the common ground level, whether they trend higher or lower. This involves assessing the voltage differences between different components within the EEG system, including the various EEG Sensor electrodes placed on the individual wireless earbuds 200, allowing for a dynamic understanding of the electrical potential variations. This referencing technique, coupled with the chosen referencing method with the individual system (such as common reference, bipolar, or Laplacian), contributes to a comprehensive analysis of the biosignal to set up the common reference potential. The combination of relative referencing along with other methods mentioned above, ensures that deviations from the common ground level are effectively captured, contributing to the overall accuracy and reliability of the EEG system's performance.

[0055] In some example embodiments, the ERPs are harnessed for the calibration of the EEG system to an individual's baseline EEG level. ERPs, formerly known as evoked potentials, are indicative of voltage fluctuations in the ongoing EEG activity that synchronize with sensory, motor, and cognitive events. ERPs play a crucial role in detecting and classifying perceptual, memory, and linguistic processes, arising from the coordinated neural activity during information processing. Typically, ERPs are derived through signal averaging, which involves the summation of synchronized electrocortical responses during each event presentation, such as a sound or an image of a face. These ERPs, in conjunction with EEG signals recorded, provide valuable insights into various neural activities related to cognitive and emotional processes that unfold rapidly and transiently, often within milliseconds. The use of artificial stimuli, such as visual flickers and auditory cues, as well as biological stimuli, which involve directing a user to switch between states of eyes-open and eyes-closed, engaging in tasks like mental arithmetic, mental singing, or mathematical operations. These stimuli elicit diverse neural responses, which are subsequently observed, measured, and subjected to quantitative analysis.

[0056] As described, ERPs are harnessed for the calibration of EEG to an individual's baseline EEG level. That is; to calibrate the EEG, the individual is exposed to specific stimuli or events while EEG signals are recorded, and then ERPs are extracted from the recorded EEG data by aligning and averaging the EEG signal around the time of the presented stimuli. ERPs contribute to the establishment of baseline features for the individual. By establishing a baseline ERP specific to the individual, the EEG can be fine-tuned to match that person's unique neural responses, enhancing the precision and personalization of EEG data collection and analysis.

[0057] In some example embodiments, the system 1000 comprises an ERP-guided artifact removal module (not shown in FIG.1) for common reference potential calculation, which utilizes the unique properties of ERPs to identify and remove artifacts in the EEG signals. Artifacts are unwanted electrical signals that can distort or obscure the underlying EEG activity. Common artifacts include muscle activity, eye blinks, and movement-related noise. These artifacts can significantly degrade the quality of EEG recordings and make it difficult to accurately interpret the data.

[0058] In some example embodiments, test signals are used for calibrating the EEG signals and hence to ensure the reliability of EEG measurements. Typically, Test Signals involve the presentation of controlled stimuli or known patterns to an individual undergoing EEG recording. Below are the steps involved in test signal-based calibration: a. Unit test signal introduction: An initial unit test signal is introduced to the EEG system. This signal is carefully designed and controlled to have specific characteristics, making it suitable for calibration purposes. It may contain known frequency components, amplitudes, and temporal patterns. b. Response examination: The response of the EEG system to this unit test signal is examined and recorded. This response reflects how the EEG system perceives and processes the input signal. It provides a baseline for understanding how the EEG system responds to known input stimuli. c. Replication and mirroring: To calibrate the EEG system, the captured response to the unit test signal is replicated and applied in a mirrored manner to the opposite side of the EEG system. This means that the system is exposed to the same unit test signal but with the signal characteristics reversed or mirrored. By doing so, the calibration process takes into account the system's symmetry and ensures that the EEG system's response is consistent on both sides.

[0059] In some example embodiments, known signal introduction and impact assessment are used for calibration. Known signals from one EEG system or machine can be transmitted to another EEG system to investigate how the known signal influences the functionality and responses of the recipient system. This is particularly useful for comparing and calibrating multiple EEG systems to ensure that they produce consistent and reliable results.

[0060] In some example embodiments, a sensor-actuator concept (Mirroring) is used for calibration. This involves identifying the environmental characteristics on one side of the EEG system and replicating these characteristics on the other side. This can be achieved throughmathematical operations or alternative techniques, effectively mirroring the environmental conditions. By doing so, the EEG system can be calibrated to perform consistently in various environmental settings.

[0061] In some example embodiments, a specialized Machine Learning (ML) model, facilitated by the controller, plays a key role in managing charging, discharging, and common reference estimation across both systems. Employing the various analyses and methods detailed earlier, this sophisticated algorithm dynamically oversees charging and discharging cycles. Its primary objectives include ensuring optimal system performance and precise computation of output parameters. Moreover, the system 1000 incorporates a continuous Machine Learning Feedback Loop, engaging in iterative learning from user data and neurofeedback. This ongoing learning process serves to enhance the accuracy of common reference calculation, refine calibration parameters, improve signal processing capabilities, generate valuable insights, and offer personalized customization based on historical data. The model is designed to efficiently operate with the assistance of a cloud server-based architecture (in cases where connectivity is not an issue) using pre-trained weights, thereby reducing the time required to initially generate meaningful output.

[0062] In some example embodiments, the utilization of an edge computing machine learning model is implemented for conducting the various analyses described above-associated with common reference calculation and signal processing, directly within the device. This approach effectively reduces time latency and enhances the operational efficiency of the system 1000. Additionally, it contributes to improved data privacy and personalization features, as the processing and analysis occur locally on the device, minimizing the need for external data transmission. The hardware-enabled onboard neural network with its self-learning capabilities can tap into other foundation neuroscience models that are available to also engage in a transformer- based machine learning output generation, thereby reducing the training period and resources required.

[0063] In some example embodiments, customized data analysis and interpretation, comparing subsequent EEG data to established baselines, enhances accuracy and offers personalized insights into individual brain activity, minimizing the impact of variations. Additionally, merging the obtained EEG data with other biosignal and health parameters like Electromyography (EMG), Electrocardiography (ECG) and Electrooculography (EOG) data from the same user enables a holistic understanding of both brain and body through the application of biopotential synergy processing.

[0064] In some example embodiments, the system 1000 supports both physical and tissue- based contralateral referencing, and the electrode design is optimized for stable, low-impedance contact.

[0065] FIG. 2 illustrates a block diagram of the charging case 100 for establishing the common reference for one or more bio-signals, according to an embodiment as disclosed herein. In some example embodiments, the charging case 100 may include several key components such as a controller 110, a voltage equalizer module 120, an edge computing module 130, a Case Lid sensor module 140, a charging port 150, a charging case battery (B1) 160, and Other conventional module(s) 170.

[0066] In some example embodiments, the controller 110 is configured to detect when the wireless earbuds 200 are inserted into the charging case. The controller 110 is configured to measure voltage deviations that occur when the wireless earbuds 200 are electrically disconnected and establishes the synchronized reference potential (i.e., common reference). This synchronization is crucial for ensuring that both wireless earbuds 200 operate in harmony, particularly during biosignal acquisition.

[0067] In some example embodiments, the voltage equalizer module 120 is configured to balance the voltage levels between the left and right earbuds 200 during both the charging and biosensing preparation phases. By maintaining a consistent electrical potential across both wireless earbuds 200, the voltage equalizer module 120 ensures that the common reference required for effective biosignal acquisition in a wireless system is achieved.

[0068] In some example embodiments, the edge computing module 130 is configured to perform auxiliary processing and coordination functions when the wireless earbuds 200 are docked in the charging case. This includes synchronizing biosignal acquisition parameters, logging diagnostic or calibration data, and securely transferring firmware or configuration updates relevant to biosensing. Additionally, the edge computing module 130 can provide co-processing capabilities, such as machine learning acceleration, by relaying data from the wireless earbuds 200 wirelessly during the undocked phase.

[0069] In some example embodiments, the Case Lid sensor module 140 is configured to detect when the lid of the charging case is opened or closed. This feature enables context-aware actions, such as initiating calibration routines or equalization sequences before the wireless earbuds 200 are removed for biosignal monitoring. This ensures that the wireless earbuds 200 are ready for accurate wireless biosensing as soon as they are in use.

[0070] In some example embodiments, the charging port 150 (typically a USB-C interface) is configured to charge the charging case battery (B1) 160 and indirectly supply power to both wireless earbuds 200. Additionally, this charging port 150 may function as a data interface for diagnostics, configuration, or firmware upgrades related to biosignal processing.

[0071] In some example embodiments, the charging case battery (B1) 160 is the primary energy storage component of the case. It not only supplies power for recharging the wireless earbuds 200 but also powers onboard modules such as the voltage equalizer module 120 and edge computing module 130, which assist in preparing the wireless earbuds 200 for biosensing tasks.

[0072] In some example embodiments, the charging case 100 contains other conventional components commonly found in typical wireless earbud charging cases 100. These include magnetic docking connectors, case microcontrollers, memory, processor, communicator, and safety circuits, all of which support basic power management and charging tasks. Together, these components create a sophisticated system that enhances the overall performance and user experience of the wireless earbuds 200.

[0073] Although FIG.2 shows various hardware components of the charging case 100, but it is to be understood that other embodiments are not limited thereon. In other embodiments, the charging case 100 may include less or more number of components. Further, the labels or names of the components are used only for illustrative purposes and does not limit the scope of the invention. One or more components can be combined to perform the same or substantially similar functions to establish the common reference for the one or more bio-signals.

[0074] FIG. 3 illustrates a block diagram of the wireless earbuds 200 for establishing the common reference for the one or more bio-signals, according to an embodiment as disclosed herein. In some example embodiments, the wireless earbuds 200 may include several key components such as an output display module 210, a biosignal data acquisition module 220, a biosignal processor module 230, an edge computing module 240, a Biosignal battery (B2) 250, a hardware enable biosignal filter 260, a voltage stabilizing module 270, a calibration module 280, an electrode sensor 290, and other conventional module(s) 291.

[0075] In some example embodiments, the output display module 210 is configured to provide visual or sensory feedback to the user. The output display module 210 may include features such as LEDs, haptic feedback, or audio indicators that communicate the system’s status, calibration prompts, or feedback related to biosignals.

[0076] In some example embodiments, the biosignal data acquisition module 220 is configured to capture and condition raw electrical signals from electrode sensor(s) 290. Thebiosignal data acquisition module 220 includes essential components like Analog Front-End (AFE) elements, which consist of instrumentation amplifiers, Analog-to-Digital Converters (ADCs), and circuits for measuring impedance, all optimized for biopotential signals such as EEG (electroencephalogram) and ECG (electrocardiogram).

[0077] In some example embodiments, the biosignal processor module 230 is configured to perform Digital Signal Processing (DSP) on the acquired biosignals. The biosignal processor module 230 carries out tasks such as noise reduction, artifact rejection, bandpass filtering, and converting raw data into detailed metrics for further analysis or transmission.

[0078] In some example embodiments, the edge computing module 240 is configured to execute higher-level computational tasks locally, such as event detection, classification (like estimating cognitive states), and biosignal quality analysis. By enabling on-device intelligence, reduces reliance on external devices.

[0079] In some example embodiments, the biosignal battery (B2) 250 serves as a dedicated power source for the biosensing electronics. The biosignal battery (B2) 250 is electrically isolated from the audio battery to minimize interference, ensuring improved signal integrity and uninterrupted operation of the sensing circuitry. This biosignal battery (B2) 250 also powers the voltage stabilizing module 270.

[0080] In some example embodiments, when the wireless earbuds 200 are removed from the charging case 100, the voltage stabilizing module 270 continuously monitors and maintains a constant reference potential. The voltage stabilizing module 270 actively counteracts any deviations in reference potential caused by external influences.

[0081] In some example embodiments, the hardware enable biosignal filter 260 is configured to implement fixed-function analog or mixed-signal filters to preprocess biosignals, such as notch filters to eliminate 50 / 60 Hz line noise and high-pass filters to remove DC offsets before digital conversion. The hardware enable biosignal filter 260 may also include hardware- accelerated digital filters for faster and more efficient filtering after conversion.

[0082] In some example embodiments, the calibration module 280 is configured to manage calibration procedures, including sensor offset correction, gain tuning, and dynamic impedance matching. The calibration module 280 may also facilitate synchronization between wireless earbuds 200 to establish a common electrical reference.

[0083] In some example embodiments, the electrode sensor(s) 290 are configured to design to contact the ear canal or nearby skin surfaces. The electrode sensor(s) 290 are tailored for lowskin contact impedance and low-noise detection of biopotentials such as EEG, ECG, or EOG (electrooculogram).

[0084] In some example embodiments, other conventional module(s) 291 include standard components such as speakers, microphones, touch sensors, memory, processor, communicator, and audio circuitry, allowing the device to function as a conventional audio playback system.

[0085] Although FIG.3 shows various hardware components of the wireless earbuds 200, but it is to be understood that other embodiments are not limited thereon. In other embodiments, the wireless earbuds 200 may include less or more number of components. Further, the labels or names of the components are used only for illustrative purposes and do not limit the scope of the invention. One or more components can be combined to perform the same or substantially similar functions to establish the common reference for the one or more bio-signals.

[0086] In some example embodiments, the charging case 100 and the wireless earbuds 200 may include the memory, the processor, and the communicator (not shown in FIG.2 and FIG.3).

[0087] In some example embodiments, the memory stores instructions to be executed by the processor for establishing the common reference for the one or more bio-signals, as discussed throughout the disclosure. The memory may include non-volatile storage elements like flash memories and non-transitory storage mediums like Random Access Memory (RAM) or caches .

[0088] In some example embodiments, the processor communicates with the memory, and the communicator. The processor is configured to execute instructions stored in the memory and to perform various processes for establishing the common reference for the one or more bio- signals, as discussed throughout the disclosure. The processor may include one or a plurality of processors, maybe a general-purpose processor, such as a Central Processing Unit (CPU), an Application Processor (AP), or the like, a graphics-only processing unit such as a Graphics Processing Unit (GPU), a Visual Processing Unit (VPU), and / or an Artificial Intelligence (AI) dedicated processor such as a Neural Processing Unit (NPU).

[0089] In some example embodiments, the communicator is configured for communicating internally between internal hardware components and with external devices (e.g., server) via one or more networks (e.g., radio technology). The communicator includes an electronic circuit specific to a standard that enables wired or wireless communication.

[0090] FIG.4 is a flow diagram illustrating a method 400 for providing the stable electrical reference while both wireless earbuds 200 are placed into the charging case 100, according to an embodiment as disclosed herein.

[0091] At operation 401, the method 400 includes detecting, at the charging case 100 associated with the wireless earbuds 200, the insertion of the right wireless earbud 200a and the left wireless earbud 200b into the charging case 100. At operation 402, the method 400 includes measuring, using the controller 110 of the charging case 100, a voltage deviation of each of the wireless earbuds 200 when each of the wireless earbuds 200 is not electrically connected to the charging case 100 in response to detecting the insertion of the right wireless earbud 200a and the left wireless earbud 200b into the charging case 100. At operation 403, the method 400 includes establishing, by the controller 110, the synchronized reference potential between the right wireless earbud 200a and the left wireless earbud 200b based on the measured voltage deviation, to ensure synchronization between both wireless earbuds 200. At operation 404, the method 400 includes storing, by the controller 110, the synchronized reference potential in the voltage stabilizing module 270 of each of the wireless earbuds 200, to provide the stable electrical reference for wireless acquisition of biosignals comprising EEG signals. Further, a detailed description related to the various operations of FIG. 4 is covered in the description related to FIG. 1, FIG. 2, and FIG.3, and is omitted herein for the sake of brevity.

[0092] FIG.5 is a flow diagram illustrating a method 500 for adjusting one or more EEG signal processing parameters within the wireless earbuds 200 to match the established personalized neural baseline, according to an embodiment as disclosed herein.

[0093] At operation 501, the method 500 includes detecting, by a biosignal data acquisition module 220 of the wireless earbud, the at least one event associated with the user of the wireless earbuds 200 while recording one or more EEG signals from the brain of the user. At operation 502, the method 500 includes segmenting, by the biosignal processor module 230 of the wireless earbuds 200, the one or more recorded EEG signals into one or more epochs relative to the at least one detected event. At operation 503, the method 500 includes extracting, in response to segmenting, the one or more ERP features to establish the personalized neural baseline for the user. At operation 504, the method 500 includes adjusting, by the biosignal processor module 230, one or more EEG signal processing parameters within the wireless earbuds 200 to match the established personalized neural baseline. Further, a detailed description related to the various operations of FIG. 5 is covered in the description related to FIG. 1, FIG. 2, and FIG. 3, and is omitted herein for the sake of brevity.

[0094] FIG. 6 is a flow diagram illustrating a method 600 for employing the detachable conductive pathway through the quick fitting mechanism, according to an embodiment as disclosed herein.

[0095] At operation 601, the method 600 includes employing the detachable conductive pathway through the quick fitting mechanism comprising at least one of the magnetic coupling and the snap fit. At operation 602, the method 600 includes establishing, in response to employing, the electrical connection between the right and left wireless earbuds 200. Further, a detailed description related to the various operations of FIG.6 is covered in the description related to FIG. 1, FIG.2, and FIG.3, and is omitted herein for the sake of brevity.

[0096] The various actions, acts, blocks, steps, or the like in the flow diagrams may be performed in the order presented, in a different order, or simultaneously. Further, in some embodiments, some of the actions, acts, blocks, steps, or the like may be omitted, added, modified, skipped, or the like without departing from the scope of the invention.

[0097] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one ordinary skilled in the art to which this invention belongs. The system, methods, and examples provided herein are illustrative only and not intended to be limiting.

[0098] While specific language has been used to describe the present subject matter, any limitations arising on account thereto, are not intended. As would be apparent to a person in the art, various working modifications may be made to the method to implement the inventive concept as taught herein. The drawings and the forgoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment.

[0099] The embodiments disclosed herein can be implemented using at least one hardware device and performing network management functions to control the elements.

[0100] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and / or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the scope of the embodiments as described herein.

Claims

We claim:

1. A method (400) for managing a wireless earbud, the method (400) comprising: detecting (401), at a charging case (100) associated with the wireless earbuds (200), an insertion of a right wireless earbud (200a) and a left wireless earbud (200b) into the charging case (100); in response to detecting the insertion of the right wireless earbud (200a) and the left wireless earbud (200b) into the charging case (100), measuring (402), using a controller of the charging case (100), a voltage deviation of the right wireless earbud (200a) and the left wireless earbud (200b) when each of the wireless earbuds (200) is not electrically connected to the charging case (100); establishing (403), by the controller, a synchronized reference potential between the right wireless earbud (200a) and the left wireless earbud (200b) based on the measured voltage deviation, to ensure synchronization between both wireless earbuds (200); and storing (404), by the controller, the synchronized reference potential in a voltage stabilizing module of each of the wireless earbuds (200), to provide a stable electrical reference for wireless acquisition of biosignals comprising Electroencephalography(EEG) signals.

2. The method (400) as claimed in claim 1, further comprising: in response to detecting that each of the wireless earbuds (200) is not electrically connected to the charging case (100), wherein each of the wireless earbuds (200) maintains the synchronization of the reference potentials in the voltage stabilizing module, wherein each of the wireless earbuds (200) counteracts one or more external voltage variations using the voltage stabilizing module to maintain an integrity of the synchronized reference potential during use, wherein each of the wireless earbuds (200) continually monitors and resynchronizes the reference potential during collections of one or more Electroencephalography (EEG) signals to ensure that each of the wireless earbuds (200) operates with the established common reference potential, andwherein a charge storage module of each of the wireless earbuds (200) provides an isolated power to a biosignal circuitry through charge storage components, thereby preventing noise interference from a main battery.

3. The method (400) as claimed in claim 2, further comprising: in response to detecting that both wireless earbuds (200) are placed into the charging case (100), measuring, by the controller, deviations from the common reference due to usage when the earbuds are returned to the charging case (100); determining whether the measured deviations are above or below a baseline, to improve a reference model for future operations; dynamically measuring, based on a relative re-referencing mechanism, voltage deviations between an electrode of the left wireless earbud (200b), an electrode of the right wireless earbud (200a), and a ground of the charging case (100); and compensating for voltage drift to ensure consistent signal acquisition across earbuds.

4. The method (400) as claimed in claim 1, wherein establishing the synchronized reference potential between the right wireless earbud (200a) and the left wireless earbud (200b) based on the measured voltage deviation comprises: recording a voltage level of each of the wireless earbuds (200) before inserting each of the wireless earbuds (200) into the charging case (100) to establish a baseline; and determining a difference between the recorded voltage level and the baseline to establish the common potential difference.

5. A method (500) for managing a wireless earbud, the method (500) comprising: detecting (501), by a biosignal data acquisition module of the wireless earbud, at least one event associated with a user of the wireless earbuds (200) while recording one or more EEG signals from a brain of the user; segmenting (502), by a biosignal processor module of the wireless earbud, the one or more recorded EEG signals into one or more epochs relative to the at least one detected event;in response to segmenting, extracting (503) one or more Event Related Potential (ERP) features to establish a personalized neural baseline for the user; and adjusting (504), by the biosignal processor module, one or more EEG signal processing parameters within the wireless earbuds (200) to match the established personalized neural baseline.

6. The method (500) as claimed in claim 5, comprising: wherein the at least one event comprises one or more auditory cues, one or more visual cues, and one or more cognitive tasks; wherein the recording of one or more Electroencephalography (EEG) signals is time-locked to an onset of the at least one event to ensure precise alignment of EEG data with the at least one event; and averaging one or more EEG responses across multiple trials of the at least one detected event to enhance the one or more ERP features by reducing a background noise 7. The method (500) as claimed in claim 5, further comprising: extracting one or more morphological features of one or more electrocardiography (ECG) signals of the user instead of the one or more ERP features in the one or more EEG signals to establish a common biosignal baseline between the two earbuds for the user, wherein one or more morphological features of the one or more ECG signals comprising at least one of peak amplitude, segment width, segment intervals, waveform shape; and adjusting, by the biosignal processor module, one or more EEG signal processing parameters within the wireless earbuds (200) to match the established biosignal baseline.

8. A method (600) for managing a wireless earbud, the method (600) comprising: employing (601) a detachable conductive pathway through a quick fitting mechanism comprising at least one of a magnetic coupling and a snap fit, to establish (602) an electrical connection between the right and left wireless earbuds (200), wherein the conductive pathway electrically connects at least one electrode of one wireless earbud to a biosignal acquisition module of the other wireless earbud for contralateral referencing,wherein the conductive pathway couples reference electrodes of both earbuds to form a unified reference potential, and wherein the conductive pathway comprises a flexible insulated conductor (201) and an auxiliary power source (202) integrated to extend battery life and enhance mechanical anchoring, and wherein the conductive pathway is coiled up inside the charging case (100) when not in use 9. The method (600) as claimed in claim 8, further comprising: establishing an electrical coupling between the right and left wireless earbuds (200) via a biological tissue of the user without a physical conductor, wherein at least one electrode on each of the wireless earbuds (200) maintains contact with one or more skin locations of the user, comprising a mastoid, a conchae, a mandibular region, a neck, wherein contralateral referencing or a common reference potential is achieved through one or more resistive and capacitive coupling properties of a skin of the user, and wherein geometry, material, and mechanical design of the at least one electrode is optimized to ensure stable, low-impedance contact during use.

10. A system (1000) for managing a wireless earbud, the system (1000) comprising: a right wireless earbud (200a) and a left wireless earbud (200b), each of wireless earbuds (200) comprising at least one biosensing electrode; a biosignal processor module for segmenting signals, extracting biosignal features, and adjusting parameters; a voltage stabilizing module for storing and maintaining a synchronized reference potential; a charge storage module providing isolated power to biosignal circuitry; a charging case (100) configured to detect insertion of the wireless earbuds (200), measure voltage deviations when disconnected, and establish a synchronized reference potential; a detachable conductive pathway comprising a flexible insulated conductor (201); an integrated auxiliary power source (202), and a magnetic or snap-fit coupling mechanism;and at least one skin-contact electrode enabling tissue-mediated electrical coupling; wherein the system (1000) supports both physical and tissue-based contralateral referencing, and the electrode design is optimized for stable, low-impedance contact.

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