Non-invasive physiological signal monitoring device and monitoring method suitable for livestock ear canals

Abstract

The invention relates to the technical field of smart animal husbandry and biosensing, and provides a non-invasive physiological signal monitoring device suitable for livestock ear canals, which comprises an ear tag main body assembly, a flexible connection assembly and a monitoring probe assembly, the ear tag main body assembly comprises a main control circuit board and a metal fixing piece, and the metal fixing piece is electrically connected with the main control circuit board to serve as a reference electrode; the flexible connection assembly comprises a flexible cable, and the first end of the flexible cable is electrically connected with the main control circuit; the monitoring probe assembly comprises an elastic supporting framework and a measuring electrode, and the second end of the flexible cable is electrically connected with the measuring electrode; the elastic supporting framework is columnar, protruding structures are arranged on the measuring electrode in an array mode, and the elastic supporting framework is coated with the measuring electrode. The invention further provides a monitoring method. The defects that in the prior art, the physiological monitoring dimension is single, effective monitoring on the neural level cannot be achieved, and signal collection fails due to the fact that a traditional electrode is difficult to adapt to the special physiological structure of the livestock ear canal are overcome.

Description

Technical Field

[0001] This invention relates to the fields of smart animal husbandry and biosensing technology, and in particular to a non-invasive physiological signal monitoring device and method suitable for livestock ear canals. Background Technology

[0002] With the rapid development of precision animal husbandry, the refined management of the individual health status of livestock (such as dairy cows and beef cattle) has become the key to improving breeding efficiency.

[0003] Currently, livestock health monitoring relies primarily on indirect external behavioral data collection methods, which are insufficient to deeply reflect the internal physiological conditions of livestock. This approach suffers from limitations such as limited monitoring dimensions and information lag, failing to meet the direct monitoring needs for the nervous system's activity. Furthermore, due to significant differences between livestock and human physiological structures, conventional bioelectrical signal acquisition devices are ill-suited to the unique physiological environment of livestock, resulting in poor signal quality and insufficient stability, making long-term stable operation in livestock farming environments difficult. Summary of the Invention

[0004] This invention provides a non-invasive physiological signal monitoring device and method suitable for livestock ear canals, which solves the defects of existing technologies such as single physiological monitoring dimensions, inability to achieve effective monitoring at the neural level, and signal acquisition failure caused by the inability of traditional electrodes to adapt to the special physiological structure of livestock ear canals. It enables long-term stable acquisition of livestock electroencephalogram (EEG) signals and body temperature data through conventional ear tag wearing, and realizes localized status recognition and transmission.

[0005] The present invention provides a non-invasive physiological signal monitoring device suitable for the ear canal of livestock, comprising: an ear tag main component, a flexible connection component, and a monitoring probe component.

[0006] The ear tag main assembly includes a main control circuit board and a metal fastener. The main control circuit board is equipped with a main control circuit. The metal fastener is configured to be fixed to the base of the animal's auricle and is electrically connected to the main control circuit as a reference electrode. The flexible connection assembly includes a flexible cable, the first end of which is electrically connected to the main control circuit. The monitoring probe assembly includes an elastic support frame and a measuring electrode, the second end of which is electrically connected to the measuring electrode.

[0007] The elastic support frame is columnar, and the measuring electrodes are arrayed with protruding structures. The measuring electrodes are covered by the elastic support frame so that the elastic support frame applies a radial expansion force to the measuring electrodes, causing the protruding structures to penetrate the hair layer in the animal's ear canal and electrically connect with the ear canal skin.

[0008] According to the non-invasive physiological signal monitoring device for livestock ear canals provided by the present invention, the main control circuit includes a bioelectric analog front end, the bioelectric analog front end includes a right leg drive output end, and the metal fixing member is electrically connected to the right leg drive output end for feeding back an anti-phase common-mode signal to the livestock body surface to suppress power frequency interference.

[0009] According to the non-invasive physiological signal monitoring device for livestock ear canals provided by the present invention, the monitoring probe assembly further includes a temperature sensor, and an axial channel is provided within the elastic support frame, wherein the temperature sensor is disposed within the axial channel; the main control circuit includes a signal multiplexing unit, and the temperature sensor is electrically connected to the main control circuit through the signal multiplexing unit.

[0010] According to the non-invasive physiological signal monitoring device for livestock ear canals provided by the present invention, the protrusion structure is a cylindrical protrusion structure, a hemispherical protrusion structure, or a circular protrusion structure.

[0011] According to the non-invasive physiological signal monitoring device for livestock ear canals provided by the present invention, the protrusion height of the protrusion structure is 0.5 mm to 2.0 mm.

[0012] According to the non-invasive physiological signal monitoring device for livestock ear canals provided by the present invention, the first end and / or the second end of the flexible cable are provided with an S-shaped buffer structure; and / or, the flexible cable is provided with a limiting ring, which is configured to be fixed to the entrance of the livestock ear canal for limiting and fixing the monitoring probe assembly.

[0013] According to the non-invasive physiological signal monitoring device for livestock ear canals provided by the present invention, the flexible cable is a shielded cable, and the shielding layer of the shielded cable is electrically connected to the active drive end of the main control circuit so that the potential of the shielding layer of the shielded cable follows the signal potential of the measuring electrode.

[0014] According to the non-invasive physiological signal monitoring device for livestock ear canals provided by the present invention, the elastic support frame is made of an insulating polymer material with shape memory properties, and in the initial state of compression, the outer diameter of the elastic support frame is smaller than the inner diameter of the livestock ear canal, and in the natural state of unfolding, the outer diameter of the elastic support frame is larger than the inner diameter of the livestock ear canal.

[0015] Another aspect of the present invention provides a monitoring method based on a non-invasive physiological signal monitoring device suitable for livestock ear canals, comprising the following steps.

[0016] The data acquisition is initiated when the contact impedance between the measuring electrode and the reference electrode is less than or equal to the preset contact impedance.

[0017] Physiological signals of livestock are collected using time-division multiplexing circuits.

[0018] The physiological signals are frequency-domain transformed using an edge computing module, and energy characteristics and electromyographic signal intensity of specific frequency bands are extracted.

[0019] Based on the energy characteristics and the electromyographic signal intensity, the physiological state information of livestock is determined, including sleep state, rumination state, activity state, and abnormal stress state.

[0020] The physiological state information is output via a wireless network.

[0021] The monitoring method of the non-invasive physiological signal monitoring device for livestock ear canals provided by the present invention further includes the following steps.

[0022] When the energy characteristics and / or the electromyographic signal intensity exceed a preset abnormal threshold, or when a waveform transmission command is received remotely, the system switches to the original waveform transmission mode. In the original waveform transmission mode, the system captures and sends the original EEG waveform data for a preset duration.

[0023] This invention provides a non-invasive physiological signal monitoring device for livestock ear canals. A metal fixing element penetrates the base of the animal's auricle (such as the cartilage at the root of the ear) and serves as a stable reference electrode. Combined with measuring electrodes encased in an elastic support frame and an array of protruding structures on their surface, the protruding structures, under the radial expansion force of the elastic support frame, effectively push aside and penetrate the dense hair and cerumen layer within the ear canal, directly establishing low-impedance, motion-interference-resistant physical electrical contact with the skin, thereby achieving high-quality acquisition of electroencephalogram (EEG) signals. Simultaneously, the device employs an integrated ear-tag design, eliminating the need for additional complex headgear or conductive gel, facilitating long-term, stable wear and continuous monitoring in the daily livestock farming environment. Therefore, this invention can directly acquire EEG signals reflecting the central nervous system activity of livestock, enabling accurate identification and early warning of neurophysiological states such as sleep, rumination, and stress. Furthermore, the integrated, low-interference structural design ensures reliability and practicality in real-world farming scenarios. It solves the systemic technical problems in existing technologies, such as signal acquisition failure caused by the special physiological structure of livestock ear canals, the inability of traditional behavior monitoring methods to reach the neurophysiological level, and the inability of existing EEG acquisition devices to meet the long-term, convenient, and low-maintenance requirements of animal husbandry. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of a non-invasive physiological signal monitoring device for livestock ear canals provided in an embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram of the monitoring probe assembly in a non-invasive physiological signal monitoring device for livestock ear canals provided in an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram of the elastic support frame in the initial state of the non-invasive physiological signal monitoring device for livestock ear canals provided in this embodiment of the invention.

[0028] Figure 4 This is a schematic diagram of the elastic support frame in the unfolded state of the non-invasive physiological signal monitoring device for livestock ear canals provided in the embodiments of the present invention.

[0029] Figure 5 This is a hardware circuit diagram of a non-invasive physiological signal monitoring device for livestock ear canals provided in an embodiment of the present invention.

[0030] Figure 6 This is a flowchart illustrating the monitoring method based on a non-invasive physiological signal monitoring device provided in an embodiment of the present invention.

[0031] Figure 7 This is a logic block diagram of a monitoring method based on a non-invasive physiological signal monitoring device provided in an embodiment of the present invention.

[0032] Figure label: 100. Ear tag main body assembly; 110. Main control circuit board; 120. Metal fastener; 130. Main body shell; 200. Flexible connection assembly; 210. Flexible cable; 220. S-shaped buffer structure; 230. Limiting ring; 300. Monitoring probe assembly; 310. Elastic support frame; 311. Axial channel; 320. Measuring electrode; 321. Protruding structure; 330. Temperature sensor. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0034] The following is combined Figures 1 to 7 This invention describes a non-invasive physiological signal monitoring device and method suitable for monitoring the ear canal of livestock.

[0035] See Figures 1 to 4 As shown, the non-invasive physiological signal monitoring device for livestock ear canals provided in this embodiment of the invention includes: an ear tag main body assembly 100, a flexible connection assembly 200, and a monitoring probe assembly 300.

[0036] The ear tag main assembly 100 includes a main control circuit board 110 and a metal fastener 120. The main control circuit board 110 is equipped with a main control circuit. The metal fastener 120 is configured to be fixed to the base of the auricle of livestock and is electrically connected to the main control circuit as a reference electrode. The flexible connection assembly 200 includes a flexible cable 210. The first end of the flexible cable 210 is electrically connected to the main control circuit. The monitoring probe assembly 300 includes an elastic support frame 310 and a measuring electrode 320. The second end of the flexible cable 210 is electrically connected to the measuring electrode 320.

[0037] The elastic support frame 310 is columnar, and the measuring electrode 320 is provided with an array of protrusions 321. The measuring electrode 320 is covered by the elastic support frame 310 so that the elastic support frame 310 applies a radial expansion force to the measuring electrode 320, so that the protrusions 321 penetrate the hair layer in the animal's ear canal and are electrically connected to the ear canal skin.

[0038] The present invention provides a non-invasive physiological signal monitoring device for livestock ear canals. A metal fixing element 120 penetrates the base of the livestock auricle (such as the cartilage at the root of the ear) and serves as a stable reference electrode. Combined with a measuring electrode 320 covered by an elastic support frame 310 and its surface array of protrusions 321, under the radial expansion force of the elastic support frame 310, the protrusions 321 effectively push aside and penetrate the dense hair and cerumen layer within the ear canal, directly establishing low-impedance, motion-interference-resistant physical electrical contact with the skin, thereby achieving high-quality acquisition of electroencephalogram (EEG) signals. Simultaneously, the device adopts an integrated ear-tag design, eliminating the need for additional complex headgear or conductive gel, facilitating long-term, stable wear and continuous monitoring in the daily livestock farming environment. Therefore, the present invention can directly acquire EEG signals reflecting the central nervous system activity of livestock, achieving accurate identification and early warning of neurophysiological states such as sleep, rumination, and stress. Furthermore, the integrated, low-interference structural design ensures reliability and practicality in real-world farming scenarios. It solves the systemic technical problems in existing technologies, such as signal acquisition failure caused by the special physiological structure of livestock ear canals, the inability of traditional behavior monitoring methods to reach the neurophysiological level, and the inability of existing EEG acquisition devices to meet the long-term, convenient, and low-maintenance requirements of animal husbandry.

[0039] Specifically, the ear tag main component 100 is used to provide mechanical fixation and electrical reference functions. Its metal fastener 120 penetrates the ear cartilage to achieve reliable fixation and at the same time serves as a reference electrode connected to the main control circuit to provide a stable electrical reference point for signal acquisition. The main control circuit board 110 integrates signal processing, edge computing and wireless communication units, which are responsible for controlling the entire device's workflow and performing preliminary processing and status judgment on the acquired signals.

[0040] The ear tag main component 100 includes a main control circuit board 110 and a metal fastener 120. The main control circuit board 110 can be a PCB board, whose core components include a main control module (such as an STM32WLE5), an analog front-end (such as an ADS1291), and a signal multiplexing unit. The metal fastener 120 can be made of stainless steel (such as 316L medical-grade stainless steel), and its surface can be gold-plated to prevent oxidation. The metal fastener 120 is used to penetrate and lock the animal's ear cartilage for mechanical fixation, and is also electrically connected to the main control circuit and configured as a reference electrode for the monitoring device. The metal fastener 120 can also be electrically connected to the analog ground (AGND) of the circuit board and the right leg drive output terminal (RLD_OUT) via an internal spring. Because the displacement of the animal's ear root relative to the skull is minimal, and the penetrating contact avoids the high-resistivity keratin layer of the skin surface, it provides an extremely low impedance and mechanically stable reference potential, effectively suppressing motion artifacts.

[0041] In some embodiments, the ear tag body assembly 100 also includes a body shell 130, which may be made of weather-resistant engineering plastic and has a sealed cavity inside for housing and protecting the main control circuit board 110 and power supply; the body shell 130 is mechanically connected to the metal fastener 120 to form an external fixing structure worn on the base of the animal's ear, and its encapsulation design can ensure that the internal electronic components can work reliably for a long time in complex environments such as humid and dusty pastures.

[0042] The flexible connection assembly 200 is used to connect the ear tag body assembly 100 and the monitoring probe assembly 300. It includes a flexible cable 210, the first end of which is electrically connected to the main control circuit and the second end of which is electrically connected to the measuring electrode 320 to transmit electrophysiological signals.

[0043] The monitoring probe assembly 300 is used to be inserted into the ear canal of livestock (to a depth of about 3cm to 5cm) to collect physiological signals. It includes an elastic support frame 310 and a measuring electrode 320 covering the elastic support frame 310. The elastic support frame 310 can adopt a "lantern-shaped" or "spring tube-shaped" columnar hollow structure, made of insulating polymer material. Its outer diameter in its natural state (e.g., 25mm) is larger than the inner diameter of the ear canal of livestock, so that after being inserted into the ear canal, the measuring electrode 320 is driven to fit tightly against the inner wall of the ear canal by its own radial rebound force. The surface of the measuring electrode 320 is provided with an array of protrusions 321. Under the action of the radial expansion force of the elastic support frame 310, the protrusions 321 are configured to penetrate the hair layer in the ear canal and establish an electrical connection with the skin.

[0044] It should be noted that the protrusion structure 321 can be used as an independent component and fixed to the metal substrate surface of the measuring electrode 320 by welding, insert molding or conductive adhesive bonding; or, the protrusion structure 321 can be integrally formed with the measuring electrode 320, that is, an array of micro-protrusions can be directly formed on the metal shell surface of the measuring electrode 320 by precision machining.

[0045] The protrusion structure 321 can be arranged in a uniform or non-uniform array. Specifically, it can be adapted to the hair distribution density and skin curvature in the animal's ear canal to ensure that the protrusion structure 321 can effectively penetrate the dense hair area and conform to the skin surface under the action of elastic expansion force, thereby achieving stable and reliable electrical contact.

[0046] As an example, in this embodiment, the main body of the measuring electrode 320 is a columnar shape adapted to the elastic support frame 310, and its end is formed with a hemispherical head structure, which is convenient for insertion into the ear canal of livestock.

[0047] According to some embodiments of the present invention, the main control circuit includes a bioelectric simulation front end, which includes a right leg drive output terminal. The metal fixing member 120 is electrically connected to the right leg drive output terminal and is used to feed back an anti-phase common-mode signal to the surface of the livestock to suppress power frequency interference.

[0048] By connecting the metal fastener 120 to the right leg drive output of the analog front end, it can actively collect common-mode interference components in biological signals and feed back anti-phase compensation signals to the surface of livestock while serving as a mechanical fastener and reference electrode. This effectively cancels out power frequency and other common-mode noise in the environment, significantly improves the signal-to-noise ratio of weak EEG signals, and ensures the quality and stability of signal acquisition in the complex electromagnetic environment of the pasture.

[0049] It should be noted that the bioelectric simulation front end is an integrated circuit specifically designed to amplify and process weak bioelectric signals. Its right leg drive circuit monitors the common-mode voltage between the organism and the acquisition system in real time through a reference electrode, and generates a drive signal with opposite phase and equal amplitude to feed back to the organism. This forms a negative feedback loop at the circuit level, actively canceling common-mode interference introduced by power line coupling, electromagnetic radiation, etc., providing key hardware support for achieving high-precision EEG acquisition in an unshielded open ranch environment.

[0050] See Figure 2 As shown, according to some embodiments of the present invention, the monitoring probe assembly 300 further includes a temperature sensor 330, an axial channel 311 is provided in the elastic support frame 310, and the temperature sensor 330 is disposed in the axial channel 311; the main control circuit includes a signal multiplexing unit, and the temperature sensor 330 is electrically connected to the main control circuit through the signal multiplexing unit.

[0051] By placing the temperature sensor 330 within the axial channel 311 of the elastic support frame 310 and electrically connecting it to the main control circuit via a signal multiplexing unit, integrated acquisition of EEG signals and body temperature data is achieved within the same probe space. Furthermore, the axial channel 311 can also serve as a communication channel between external air and sound waves, ensuring airflow inside and outside the livestock's ear canal, preventing obstruction of hearing, and mitigating stress responses caused by hearing loss.

[0052] Specifically, the signal multiplexing unit uses time-division switching of connection paths to make the metal shell of the measuring electrode 320 a conductive acquisition surface for EEG signals in the first time period and a medium for conducting heat to the temperature sensor 330 in the second time period. This achieves efficient synchronous monitoring of multiple physiological parameters without adding an additional independent probe, simplifying the device structure and improving wearing comfort and reliability.

[0053] It should be noted that the signal multiplexing unit is an electronic switching circuit controlled by the main control module. It is usually implemented using an analog switch chip with low on-resistance. Its common terminal is connected to the common signal line of the measuring electrode 320, and the two switching terminals are respectively connected to the signal input channel of the analog front end and the analog-to-digital conversion input channel of the main control module. Through the timing control of the main control module, the signal path connected to the measuring electrode 320 is switched to the EEG acquisition circuit or the temperature sensing circuit in a time-division manner. This enables the time-division multiplexing acquisition and transmission of two heterogeneous signals using a single cable, which minimizes the space occupation and connection complexity inside the ear canal probe while ensuring signal quality.

[0054] According to some embodiments of the present invention, the protrusion structure 321 is a cylindrical protrusion structure, a hemispherical protrusion structure, or an annular protrusion structure.

[0055] By designing the protrusion structure 321 into different geometric shapes such as cylindrical, hemispherical, or annular, it can adapt to different skin contact mechanics and hair penetration requirements. Among them, the cylindrical protrusion is conducive to deep dispersal of dense hair, the hemispherical protrusion provides a gentler skin contact pressure to reduce irritation, and the annular protrusion forms a ring-shaped conductive area upon contact to increase the contact area and stability. Thus, reliable low-impedance electrical contact can be achieved under different livestock breeds, ear canal physiological states, and wearing conditions, improving the adaptability of EEG signal acquisition.

[0056] According to some embodiments of the present invention, the protrusion height of the protrusion structure 321 is 0.5 mm to 2.0 mm.

[0057] By setting the height of the protrusion structure 321 to 0.5mm to 2.0mm, it can effectively penetrate the common velvet and cerumen layer in the ear canal of livestock. At the same time, it avoids excessive pressure on the skin due to excessive height, which may cause discomfort or damage, or insufficient height, which may prevent the establishment of effective electrical contact. This ensures that under the radial pressure of the elastic support frame 310, the protrusion structure 321 can reliably penetrate the hair insulation layer and establish stable physical contact with the skin surface to reduce impedance, while maintaining the comfort and safety of the livestock wearing it. This achieves a balance between signal quality and animal adaptability in long-term monitoring.

[0058] As an example, the protrusion height of the protrusion structure 321 can be 0.5mm, 1mm, 1.5mm or 2.0mm, etc. Preferably, it is 1mm to 1.5mm.

[0059] join Figure 1 As shown, according to some embodiments of the present invention, the first end and / or the second end of the flexible cable 210 are provided with an S-shaped buffer structure 220.

[0060] By setting an S-shaped buffer structure 220 at the first and / or second ends of the flexible cable 210, it can effectively absorb and buffer the tensile, bending and torsional loads at the connection between the cable and the ear tag main component 100 and the monitoring probe component 300 during the daily activities, head shaking or chewing of livestock. This prevents loosening of the connection, cable breakage or solder joint failure caused by stress concentration, thereby significantly improving the mechanical reliability and durability of the entire device in dynamic use environments, ensuring continuous and stable signal transmission, and extending the service life of the equipment under harsh pasture conditions.

[0061] It should be noted that the S-shaped buffer structure 220 is the redundant length of the buffer cable itself, or a curved wave section formed by pre-forming process at the end of the cable. Its function is to reserve a certain space for expansion and deformation, so that the cable itself can dissipate the tensile stress when the livestock's head moves, and avoid the rigid connection point from bearing too much mechanical load. Thus, while ensuring the reliability of electrical connection, it enhances the adaptability of the entire monitoring device to the daily activities of livestock.

[0062] join Figure 1 As shown, according to some embodiments of the present invention, a limiting ring 230 is provided on the flexible cable 210. The limiting ring 230 is configured to be fixed to the ear canal entrance of the livestock for limiting and fixing the monitoring probe assembly 300.

[0063] By setting a limiting ring 230 on the flexible cable 210 and fixing it at the entrance of the livestock's ear canal, the travel distance of the monitoring probe assembly 300 to the depth of the ear canal can be physically limited, preventing the probe from touching the sensitive bony ear canal or tympanic membrane area due to excessive insertion, thereby avoiding discomfort or damage to the livestock. At the same time, the limiting ring 230, together with the radial expansion force of the elastic support frame 310, ensures the axial position stability of the monitoring probe assembly 300 in the ear canal, reduces signal fluctuations or contact failures caused by probe displacement, and improves the stability of signal acquisition and the safety of wearing.

[0064] The limiting ring 230 is preferably made of soft silicone or thermoplastic elastomer to avoid pressure damage to the skin of the auricle, and has a certain coefficient of friction to maintain a stable position at the entrance of the ear canal, thereby ensuring the comfort of livestock while achieving a reliable limiting function.

[0065] According to some embodiments of the present invention, the flexible cable 210 is a shielded cable, and the shielding layer of the shielded cable is electrically connected to the active drive end of the main control circuit so that the potential of the shielding layer of the shielded cable follows the signal potential of the measuring electrode 320.

[0066] By setting the flexible cable 210 as a shielded cable and electrically connecting its shielding layer to the active drive end of the main control circuit, the potential of the shielding layer follows the signal potential of the measuring electrode 320 in real time, thereby eliminating the potential difference between the core wire and the shielding layer. This effectively suppresses the high-frequency signal attenuation caused by distributed capacitance and the noise generated by the triboelectric effect when the cable swings, ensuring the integrity and signal-to-noise ratio of the microvolt-level EEG signal during transmission and improving the signal acquisition quality of the entire system under dynamic and electromagnetic interference environments.

[0067] It should be noted that the active drive terminal of the main control circuit provides a buffered voltage output pin with high input impedance and low output impedance for the bioelectric analog front-end chip. Its output voltage is synchronized in real time with the signal potential collected by the measurement electrode 320. Driving this voltage to the shielding layer of the shielded cable can make the shielding layer and the signal core wire be at the same potential, thereby eliminating the bypass effect of parasitic capacitance between the two on the high-frequency signal and preventing external electric fields from entering the signal path through capacitive coupling. This is a key anti-interference technology to maintain signal fidelity in high-impedance bioelectric measurements.

[0068] See Figure 3 and Figure 4 As shown, according to some embodiments of the present invention, the elastic support frame 310 is made of an insulating polymer material with shape memory properties, and in the initial state of compression, the outer diameter of the elastic support frame 310 is smaller than the inner diameter of the animal's ear canal, and in the natural state of unfolding, the outer diameter of the elastic support frame 310 is larger than the inner diameter of the animal's ear canal.

[0069] By designing the elastic support frame 310 to be made of an insulating polymer material with shape memory properties, its outer diameter is smaller than the inner diameter of the ear canal in the compressed state to facilitate insertion, while its outer diameter is larger than the inner diameter of the ear canal when it returns to its natural unfolded state after insertion into the ear canal. This allows the material to generate continuous and adaptive radial expansion pressure by relying on its own shape recovery force. On the one hand, this ensures that the measuring electrode 320 and its protruding structure 321 fit tightly against the ear canal skin and penetrate the hair layer. On the other hand, it also provides stable mechanical fixation for the probe, effectively resisting probe displacement or loosening caused by livestock movement. This achieves stable and reliable electrical contact and signal acquisition in complex dynamic environments without the need for external fastening devices.

[0070] The principle of the hardware circuit in the non-invasive physiological signal monitoring device for livestock ear canals provided by the present invention will be described below.

[0071] This embodiment focuses on describing the electronic hardware and signal flow, such as Figure 5As shown, the main control circuit is integrated on the PCB board of the ear tag main component 100, and the core includes a main control module (such as STM32WLE5), an analog front end (such as ADS1291) and a signal multiplexing unit.

[0072] Regarding probe multiplexing and signal path, due to the limited space of the ear canal probe, this embodiment uses time-division multiplexing technology to transmit two physical quantities, EEG and body temperature, through a single signal line. The specific connection logic is as follows: the metal measuring electrode 320 inside the probe shares a single signal core line with one end of the NTC thermistor, and the other end of the NTC is grounded via a return line; the signal multiplexing unit uses a low on-resistance analog switch chip, and its common terminal is connected to this shared signal core line; path A is the EEG mode, where the analog switch tangent channel 1 is connected to the positive input terminal of the analog front end, and the metal electrode only acts as a voltage sensing probe to collect microvolt-level EEG signals; path B is the temperature mode, where the analog switch tangent channel 2 is connected to the voltage divider resistor network and the analog-to-digital converter input terminal of the main control module, and the main control module outputs an excitation current that flows through the NTC to read the temperature value.

[0073] In terms of operating sequence, the system is in EEG mode by default. Every preset cycle, the main control module controls the analog switch to briefly switch to path B to complete the temperature measurement, and then immediately switches back to path A.

[0074] In terms of anti-interference and shielding design, the right leg drive amplifier inside the analog front end collects the common-mode interference components in the biological signal through the reference electrode, and after inversion processing, forms a compensation signal and feeds it back to the surface of the livestock through the same reference electrode to achieve active cancellation of common-mode noise. At the same time, the shielding layer of the flexible cable 210 is connected to the active drive end of the analog front end. The drive end outputs a buffer signal with the same potential as the signal core wire, so that the potential difference between the core wire and the shielding layer is kept at zero, thereby eliminating the cable distributed capacitance effect, preventing high-frequency signal attenuation and suppressing the triboelectric noise introduced by cable swing.

[0075] The monitoring method based on a non-invasive physiological signal monitoring device provided by this invention is described below. The monitoring method based on a non-invasive physiological signal monitoring device described below is the same as that described above. See Figure 6 and Figure 7 As shown in the figure, the monitoring method based on a non-invasive physiological signal monitoring device suitable for livestock ear canals provided by the embodiments of the present invention includes the following steps.

[0076] S610: Start data acquisition based on the fact that the contact impedance between the measuring electrode 320 and the reference electrode is less than or equal to the preset contact impedance.

[0077] S620: Collects physiological signals of livestock through a time-division multiplexing circuit, including electroencephalogram (EEG) signals.

[0078] S630: Use the edge computing module to perform frequency domain transformation on physiological signals and extract energy characteristics and electromyographic signal intensity of specific frequency bands.

[0079] S640. Based on energy characteristics and electromyographic signal intensity, determine the physiological state information of livestock, including sleep state, rumination state, activity state, and abnormal stress state.

[0080] S650 outputs physiological status information via wireless network.

[0081] The present invention provides a monitoring method based on a non-invasive physiological signal monitoring device suitable for livestock ear canals. Before signal acquisition, the contact impedance between the measuring electrode 320 and the reference electrode is checked and confirmed to meet requirements, ensuring a reliable signal acquisition foundation. Then, time-division multiplexing circuits are used to alternately acquire EEG signals and body temperature data. An edge computing module is used to perform localized frequency domain analysis on the EEG signals, extracting characteristic indicators reflecting neural and muscle activity. Based on these characteristics, various physiological states of livestock, such as sleep, rumination, activity, and abnormal stress, are automatically identified. Finally, lightweight state classification results are output only through a low-power wireless network. This significantly reduces data transmission volume and overall system power consumption while ensuring real-time and accurate monitoring, achieving long-term, continuous, and non-invasive intelligent monitoring of the core physiological states of livestock.

[0082] Specifically, in step S610, the contact impedance between the measuring electrode 320 and the reference electrode can be periodically detected. If the detected contact impedance is lower than or equal to the preset contact impedance (e.g., 20MΩ), it is determined that the electrode and the skin conductance are in good contact, and the bioelectric signal acquisition process is automatically started. If the contact impedance is higher than the preset contact impedance threshold, it is determined that the contact is poor or the probe is dislodged. The system suspends the EEG acquisition and only maintains the basic temperature measurement and communication functions. At the same time, it reports the abnormal wearing status, so as to ensure that subsequent processing is only carried out under the premise that the signal quality is reliable, thus ensuring the effectiveness of data analysis and the accuracy of monitoring results from the source.

[0083] In step S620, the physiological signals include EEG signals and temperature signals. The main control module controls the analog switch in the signal multiplexing unit to perform time-division switching. During the default EEG acquisition period, the analog switch connects the measuring electrode 320 to the analog front-end input channel to acquire the raw EEG waveform at the microvolt level. During the periodically inserted temperature acquisition period, the analog switch briefly switches the path, switching the signal line connected to the measuring electrode 320 to the temperature sensing loop. The main control module applies excitation to the temperature sensor 330 and reads its response signal to calculate body temperature. This achieves time-division alternating acquisition of two heterogeneous physiological signals, EEG and body temperature, on a single path. While ensuring signal independence and quality, this simplifies the probe structure and enables multi-parameter integrated monitoring.

[0084] In step S630, the edge computing module performs a fast Fourier transform on a segment of the acquired EEG signal, converting it from the time domain to the frequency domain. It then calculates and extracts energy features within a preset frequency band. For example, low-frequency waves (energy in the 1Hz to 2Hz band) are used to assess deep sleep or pathological coma; mid-to-low-frequency waves (energy in the 2Hz to 5Hz band) are used to assess a conscious, still state; the alpha band (energy in the 5Hz to 10Hz band) is used to assess normal behavioral activity; and high-frequency electromyography (energy above 10Hz) is extracted as an electromyographic signal intensity index to assess rumination, chewing, or stress-induced movement levels, thus providing quantitative neural and muscular activity characteristics for subsequent state classification.

[0085] In step S640, the extracted energy features of each frequency band and the electromyographic signal intensity are input into a preset classification algorithm or rule model for comprehensive judgment: when the low-frequency energy is significantly dominant and the electromyographic intensity is extremely low, it is determined to be a sleep state; when the electromyographic signal shows regular rhythmic bursts and is accompanied by a specific mid-frequency energy pattern, it is determined to be a rumination state; when the energy distribution of each frequency band is balanced and the electromyographic signal is continuously active, it is determined to be an active state; when there is an abnormal mutation in the energy of a specific frequency band, a non-rhythmic strong burst of the electromyographic signal, or a feature combination that exceeds the normal range, it is determined to be an abnormal stress state, thereby realizing the automated identification and classification of the core behaviors and health status of livestock based on neuroelectrophysiological characteristics.

[0086] In step S650, the physiological state information obtained from the classification is encoded into lightweight data packets and sent through a low-power wide-area wireless network. In the normal monitoring mode, only a low-data-volume state report containing the state category code and key feature values ​​is uploaded periodically to achieve long-term battery life.

[0087] According to some embodiments of the present invention, the monitoring method based on a non-invasive physiological signal monitoring device suitable for livestock ear canals further includes the following steps.

[0088] When the energy characteristics and / or electromyographic signal intensity exceed a preset abnormal threshold, or when a waveform transmission command is received remotely, the system switches to the original waveform transmission mode. In the original waveform transmission mode, the system captures and sends the original EEG waveform data for a preset duration.

[0089] By establishing an abnormal triggering and command response mechanism, when the energy characteristics or electromyographic signal intensity obtained from local analysis exceed the preset abnormal threshold, or when the device receives a waveform transmission command actively issued remotely, the system automatically switches from the normal status reporting mode to the raw waveform transmission mode. In this mode, the device encapsulates and compresses the high-sampling-rate raw EEG waveform data of a preset duration before and after the triggering event in the cache, and uploads it through a wireless network. This ensures that raw signal data available for in-depth analysis can be provided when a suspected health event occurs or when manual intervention is required for diagnosis, while maintaining low power consumption most of the time, thus achieving an effective balance between monitoring efficiency and diagnostic capability.

[0090] In the hierarchical transmission strategy, the normal mode is as follows: the system only sends status codes and corresponding values ​​through the LoRa protocol, and the data format is as follows.

[0091] Diagnostic Mode (Trigger-based): When the local algorithm detects pain stress characteristics or receives a "waveform retrieval" command from the cloud, the system compresses the cached 10-second raw waveform data, uploads it in packets to the gateway, and allows users to perform remote waveform diagnosis.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A non-invasive physiological signal monitoring device suitable for livestock ear canals, characterized in that, include: The ear tag main body assembly includes a main control circuit board and a metal fastener. The main control circuit board is provided with a main control circuit. The metal fastener is configured to be fixed to the base of the auricle of a domestic animal, and the metal fastener is electrically connected to the main control circuit to serve as a reference electrode. A flexible connection assembly, the flexible connection assembly including a flexible cable, the first end of the flexible cable being electrically connected to the main control circuit; A monitoring probe assembly, comprising an elastic support frame and measuring electrodes, wherein the second end of the flexible cable is electrically connected to the measuring electrodes; The elastic support frame is columnar, and the measuring electrodes are arrayed with protruding structures. The measuring electrodes are covered by the elastic support frame so that the elastic support frame applies a radial expansion force to the measuring electrodes, causing the protruding structures to penetrate the hair layer in the animal's ear canal and electrically connect with the ear canal skin.

2. The non-invasive physiological signal monitoring device for livestock ear canals according to claim 1, characterized in that, The monitoring probe assembly also includes a temperature sensor, and the elastic support frame has an axial channel, in which the temperature sensor is located; The main control circuit includes a signal multiplexing unit, and the temperature sensor is electrically connected to the main control circuit through the signal multiplexing unit.

3. The non-invasive physiological signal monitoring device for livestock ear canals according to claim 1, characterized in that, The main control circuit includes a bioelectric simulation front end, which includes a right leg drive output terminal. The metal fixing component is electrically connected to the right leg drive output terminal and is used to feed back an anti-phase common-mode signal to the animal's body surface to suppress power frequency interference.

4. The non-invasive physiological signal monitoring device for livestock ear canals according to claim 1, characterized in that, The protrusion structure is a cylindrical protrusion structure, a hemispherical protrusion structure, or a circular protrusion structure.

5. The non-invasive physiological signal monitoring device for livestock ear canals according to claim 1, characterized in that, The protrusion height of the protrusion structure is from 0.5 mm to 2.0 mm.

6. The non-invasive physiological signal monitoring device for livestock ear canals according to any one of claims 1 to 5, characterized in that, The first and / or second ends of the flexible cable are provided with an S-shaped buffer structure; And / or, the flexible cable is provided with a limiting ring, which is configured to be fixed to the ear canal entrance of the livestock for limiting and fixing the monitoring probe assembly.

7. The non-invasive physiological signal monitoring device for livestock ear canals according to any one of claims 1 to 5, characterized in that, The flexible cable is a shielded cable, and the shielding layer of the shielded cable is electrically connected to the active drive end of the main control circuit so that the potential of the shielding layer of the shielded cable follows the signal potential of the measuring electrode.

8. The non-invasive physiological signal monitoring device for livestock ear canals according to any one of claims 1 to 5, characterized in that, The elastic support frame is made of an insulating polymer material with shape memory properties. In the initial state of compression, the outer diameter of the elastic support frame is smaller than the inner diameter of the animal's ear canal. In the natural state of unfolding, the outer diameter of the elastic support frame is larger than the inner diameter of the animal's ear canal.

9. A monitoring method based on a non-invasive physiological signal monitoring device suitable for livestock ear canals as described in any one of claims 1 to 8, characterized in that, include: The data acquisition is initiated based on the contact impedance between the measuring electrode and the reference electrode being less than or equal to the preset contact impedance. Physiological signals of livestock are collected using time-division multiplexing circuits; The physiological signals are frequency domain transformed using an edge computing module, and energy features and electromyographic signal intensity of specific frequency bands are extracted. Based on the energy characteristics and the electromyographic signal intensity, the physiological state information of livestock is determined, including sleep state, rumination state, activity state and abnormal stress state. The physiological state information is output via a wireless network.

10. The monitoring method of the non-invasive physiological signal monitoring device for livestock ear canals according to claim 9, characterized in that, Also includes: When the energy characteristics and / or the electromyographic signal intensity exceed a preset abnormal threshold, or when a waveform transmission command is received remotely, the system switches to the original waveform transmission mode. In the original waveform transmission mode, the system captures and sends the original EEG waveform data for a preset duration.

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