Extremely simple myoelectricity and body temperature monitoring electrode system

Abstract

The invention provides an extremely simple myoelectricity and body temperature monitoring electrode system, which is characterized in that firstly, a composite conductive film prepared by mixing PEDOT: PSS and PEO according to a mass ratio of 1: 2 is directly prepared on a flexible substrate to form an ultrathin integrated structure which is 250-350nm and can be conformally attached, and the single electrode structure has double functions of collecting a myoelectricity signal and a body temperature signal; secondly, the body temperature signal and the electromyographic signal are fused into an output signal in a simulation domain in a hardware circuit coupling mode, an electromyographic baseline is modulated through the body temperature, and true synchronization and single-channel output are achieved; therefore, the problems of wearing comfort and signal stability are solved through innovative electrode materials and structural design, synchronous acquisition and processing of myoelectricity and body temperature signals in a single channel are achieved through a unique signal coupling method, and therefore the problems that in the prior art, a system is complex, and synchronism is poor are solved.

Description

Technical Field

[0001] This invention belongs to the field of biomedical engineering and wearable health monitoring technology, and in particular relates to a minimally invasive electromyography and body temperature monitoring electrode system. Background Technology

[0002] Electromyography (EMG) signals and body temperature are important physiological parameters for assessing human health and athletic performance. Currently, the acquisition of physiological signals in wearable health monitoring devices largely relies on independent acquisition using different types of sensors. For example, EMG signal acquisition typically uses gel electrodes or rigid dry electrodes, while body temperature monitoring commonly employs thermistors. While these approaches are technically mature, they struggle to meet the comprehensive requirements of modern wearable devices for integration, comfort, and long-term stability. In recent years, although some research has attempted to develop flexible, multifunctional sensors, achieving high-quality synchronous acquisition and efficient coupling of multiple signals remains a significant technical challenge in practical applications.

[0003] Current electromyography (EMG) monitoring electrodes primarily use silver / silver chloride (Ag / AgCl) wet electrodes, which offer good conductivity but require electrolytic gel. Prolonged wear can lead to skin discomfort, and signal stability decreases as the gel dries. Recently developed dry electrodes are mostly fabricated using metals (such as gold and silver) or carbon-based materials (such as graphene and carbon nanotubes). While avoiding the use of gels, they still suffer from high skin contact impedance, insufficient flexibility, and complex fabrication processes. Body temperature monitoring electrodes mostly employ thermistors or metal resistance temperature detectors (RTDs). These components typically require additional encapsulation and protective layers, increasing the device's thickness and rigidity, thus affecting wearing comfort.

[0004] In signal acquisition and processing, existing technologies typically employ a separate approach. This involves acquiring electromyography (EMG) and body temperature signals using independent electrodes and sensors, then recording them synchronously through a multi-channel data acquisition system. This approach requires complex hardware circuitry for signal synchronization, increasing system complexity and power consumption. Another approach physically integrates the two sensors onto the same substrate, but the signals are still output and processed separately through different channels, failing to achieve true signal-level fusion. This type of approach cannot resolve the problem of mutual interference between signals and requires complex back-end algorithms for data fusion analysis.

[0005] Therefore, existing electromyography (EMG) and body temperature monitoring electrodes typically suffer from problems such as large size, uncomfortable wearing, and poor signal stability, making it difficult to meet the requirements of wearable devices for thinness, comfort, and high precision. Although some ultra-thin electrodes have been proposed, they often face challenges such as complex manufacturing processes, high costs, insufficient mechanical properties, and unstable signal acquisition. Furthermore, existing EMG and body temperature monitoring systems mostly use independent sensors to collect signals separately, leading to problems such as complex equipment, high costs, poor synchronization, poor portability, and complex data processing. Current technologies lack effective signal coupling methods, making it impossible to achieve efficient synchronous monitoring of the two signals. Therefore, there is currently no existing EMG and body temperature monitoring electrode system that can simultaneously meet the requirements of thinness, comfort, low cost, and high performance. Summary of the Invention

[0006] To address the aforementioned issues, this invention provides a simplified electromyography and body temperature monitoring electrode system. It employs analog circuitry to directly couple the DC signal of body temperature with the AC signal of electromyography at the front end, outputting a single composite signal, thus achieving complete synchronization of the two signals in time and space.

[0007] A minimalist electromyography and body temperature monitoring electrode system includes an electrode module, a processing module, and an adder; The electrode module includes four flexible thin-film electrodes that are all attached to the skin surface. One flexible thin-film electrode is used to collect temperature signals, and the other three flexible thin-film electrodes are used to collect electromyographic signals at different locations. Two of the electromyographic signals are used as the raw electromyographic signals, and the other electromyographic signal is used as the reference electromyographic signal. The processing module uses a three-electrode method to process three electromyographic signals to obtain noise-reduced electromyographic signals; The adder is used to superimpose the temperature signal and the noise-reduced electromyography (EMG) signal to output a coupled signal, wherein the baseline amplitude of the coupled signal represents the temperature and the pulse sequence of the coupled signal represents the noise-reduced EMG signal.

[0008] Furthermore, a minimalist electromyography and body temperature monitoring electrode system includes an amplifier; The amplifier is used to amplify the temperature signal, and then the amplified temperature signal is input into the adder.

[0009] Furthermore, each flexible thin-film electrode is an integrated structure coated with a composite conductive film on a flexible substrate, and the composite conductive film is made by mixing PEDOT:PSS and PEO in a mass ratio of 1:2.

[0010] Furthermore, the method for acquiring temperature signals using flexible thin-film electrodes is as follows: PEDOT:PSS in composite conductive films generates thermoelectric potential through the Seebeck effect when the temperature changes, and the temperature signal can be obtained by directly acquiring the thermoelectric potential.

[0011] Furthermore, the thickness of the composite conductive film is between 250 nm and 350 nm, and the thickness of the flexible substrate is set according to the actual application requirements.

[0012] Furthermore, the adder includes an operational amplifier, fixed resistors R1 and R2, a reference resistor Rf, and an adjustable resistor Ri; One end of the fixed resistor R1 is connected to the noise-reducing electromyography signal, and the other end is connected to the non-inverting input of the operational amplifier; one end of the fixed resistor R2 is connected to the temperature signal, and the other end is connected to the non-inverting input of the operational amplifier; one end of the reference resistor Rf is connected to the inverting input of the operational amplifier, and the other end is connected to the output of the operational amplifier; one end of the adjustable resistor Ri is connected to the inverting input of the operational amplifier, and the other end is grounded.

[0013] Furthermore, the fabrication method of the flexible thin-film electrode is as follows: (1) Preparation of PEO solution: Dissolve PEO in DMF to prepare a solution with a concentration of 10 mg / mL; (2) Mixing PEDOT:PSS solution: Mix aqueous PEDOT:PSS solution with PEO solution at a mass ratio of 1:2 and stir for 2 hours to obtain composite electrode solution; (3) Substrate treatment: The PET substrate is subjected to oxygen plasma treatment for 3 minutes; (4) Spin-coating composite electrode solution: Spin-coating the composite electrode solution onto the treated PET substrate to obtain the electrode sample; (5) Heat treatment: Place the electrode sample on a hot plate and anneal at 110°C for 15 minutes; (6) Patterned electrode: The annealed electrode sample is cut into the required electrode shape using a laser cutter to obtain the final flexible thin film electrode.

[0014] Furthermore, the spin coating time for the composite electrode solution was 20 seconds, and the rotation speed was 1500 rpm.

[0015] Beneficial effects: 1. This invention provides a simplified electromyography (EMG) and body temperature monitoring electrode system. First, a composite conductive film made by mixing PEDOT:PSS and PEO in a 1:2 mass ratio is directly fabricated on a flexible substrate to form an ultra-thin, conformally attachable integrated structure of 250-350 nm. This single electrode structure itself has the dual function of acquiring EMG and body temperature signals. Second, the body temperature and EMG signals are fused into a single output signal in the analog domain through hardware circuit coupling. The EMG baseline is modulated by body temperature, achieving true synchronization and single-channel output. Thus, this invention solves the problems of wearing comfort and signal stability through innovative electrode materials and structural design, and achieves synchronous acquisition and processing of EMG and body temperature signals in a single channel through a unique signal coupling method, thereby overcoming the problems of system complexity and poor synchronization in the prior art.

[0016] 2. This invention provides a simplified electromyography and body temperature monitoring electrode system. A composite electrode based on PEO and PEDOT:PSS is prepared through steps including dissolution, mixing, substrate treatment, spin coating, heat treatment, and patterning. This preparation process is simple, efficient, and suitable for large-scale production. In other words, this invention, with its unique electrode preparation process and dual-mode signal coupling technology, provides an efficient, convenient, and reliable solution for the field of human physiological signal monitoring. This system is particularly suitable for medical monitoring, sports health monitoring, and other scenarios, possessing broad application prospects and significant innovative value. The process is simple and suitable for mass production. Attached Figure Description

[0017] Figure 1 A schematic diagram of a simplified electromyography and body temperature monitoring electrode system provided by the present invention; Figure 2 This is a schematic diagram of the output signal of dual-mode data coupling provided by the present invention; Figure 3 A schematic diagram of the adder circuit provided by the present invention; Figure 4 A flowchart illustrating the fabrication process of the simplified electrode provided by this invention; Figure 5 The uniformity of the simplified electrode provided by this invention; Figure 6 The conductivity and stability provided by this invention. Detailed Implementation

[0018] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0019] like Figure 1As shown, a simplified electromyography and body temperature monitoring electrode system includes an electrode module, a processing module, an adder, and an amplifier. The electrode module includes four flexible thin-film electrodes, each attached to the skin surface. One flexible thin-film electrode is used to acquire temperature signals, and the other three are used to acquire surface potentials at different locations. Two signals from the muscle activity zone are used as the raw electromyographic signals, and the signal from the electrical quiescent zone is used as the reference signal. Each flexible thin-film electrode is an integrated structure with a composite conductive film coated on a flexible substrate. The composite conductive film is made by mixing PEDOT:PSS and PEO in a 1:2 mass ratio. The PEDOT:PSS in the composite conductive film generates a thermoelectric potential through the Seebeck effect when the temperature changes. The temperature signal can be obtained by directly acquiring the thermoelectric potential. The thickness of the composite conductive film is between 250 nm and 350 nm, and the thickness of the flexible substrate is set according to the actual application requirements.

[0020] The processing module uses a three-electrode method to process the electromyographic signal to obtain a noise-reduced electromyographic signal; The amplifier is used to amplify the temperature signal, and then the amplified temperature signal is input into the adder. The adder is used to superimpose the temperature signal and the noise-reduced electromyographic signal, and output a coupled signal, wherein, as... Figure 2 As shown, the baseline amplitude of the coupled signal represents the temperature, and the pulse sequence of the coupled signal represents the noise-reduced electromyography (EMG) signal. It should be noted that this invention uses the temperature signal as the baseline; changes in temperature will alter the baseline position without affecting the integrity of the EMG signal. Furthermore, based on the PEDOT:PSS conductive electrode, its voltage output signal has a linear relationship with temperature. The signal processing system in the host computer can calculate the real-time temperature from the current signal value using preset linear calibration parameters.

[0021] Specifically, such as Figure 3 As shown, the adder includes an operational amplifier, fixed resistors R1 and R2, a reference resistor Rf, and an adjustable resistor Ri; wherein, one end of the fixed resistor R1 is connected to the noise-reduced electromyography signal, and the other end is connected to the non-inverting input of the operational amplifier; one end of the fixed resistor R2 is connected to the temperature signal, and the other end is connected to the non-inverting input of the operational amplifier; one end of the reference resistor Rf is connected to the inverting input of the operational amplifier, and the other end is connected to the output of the operational amplifier; one end of the adjustable resistor Ri is connected to the inverting input of the operational amplifier, and the other end is grounded.

[0022] In other words, the adder receives a clear electromyographic signal acquired by the three-electrode method and conditioned by the circuit, as well as a temperature signal (generated by thermoelectricity) after amplification, and then outputs a signal superimposed on the temperature baseline signal and the electromyographic signal.

[0023] Based on this, the working principle of the simplified electromyography and body temperature monitoring electrode system provided by the present invention can be summarized as follows: This invention involves patterning the prepared electrodes and then attaching four electrodes to the skin surface at specific positions. Based on the classic architecture of "dual acquisition electrodes + single reference electrode," two electrodes acquire the raw electromyographic (EMG) signals, while the reference electrode serves as a signal reference to cancel environmental noise and common-mode interference from the human body. The acquired raw EMG signals are then amplified by a differential amplifier circuit to suppress common-mode interference and obtain a clear EMG signal (voltage). PEDOT:PSS generates a thermoelectric potential due to the Seebeck effect; directly acquiring this potential yields the temperature signal. This method amplifies the voltage signal for body temperature monitoring using an amplifier, and then uses an adder circuit to couple the EMG signal with the amplified body temperature signal. The temperature signal raises the baseline of the EMG signal, enabling simultaneous monitoring of body temperature changes and complete EMG signals.

[0024] like Figure 4 As shown, the method for preparing the flexible thin-film electrode used in this invention is as follows: (1) Preparation of PEO solution: Dissolve PEO in DMF to prepare a solution with a concentration of 10 mg / mL; (2) Mixing PEDOT:PSS solution: Mix aqueous PEDOT:PSS solution with PEO solution at a mass ratio of 1:2 and stir vigorously for 2 hours to obtain composite electrode solution; (3) Substrate treatment: The PET substrate is subjected to oxygen plasma treatment for 3 minutes; (4) Spin-coating composite electrode solution: Spin-coating the composite electrode solution onto the treated PET substrate to obtain the electrode sample; the spin-coating time for the composite electrode solution is 20 seconds and the rotation speed is 1500 rpm; (5) Heat treatment: Place the electrode sample on a hot plate and anneal at 110°C for 15 minutes; (6) Patterned electrode: The annealed electrode sample is cut into the required electrode shape using a laser cutter to obtain the final flexible thin film electrode.

[0025] Figure 5 This illustrates the uniformity of the simplified electrode in this embodiment. The thickness of the PEDOT:PSS / PEO film is between 250 nm and 350 nm, and the thickness of the PET can be controlled according to usage requirements. This ultra-thin structural design not only improves the stability of signal acquisition but also significantly enhances wearing comfort, solving the problems of unstable signal acquisition and discomfort associated with traditional electrodes.

[0026] Figure 6This section describes the conductivity and stability of the electrode in this embodiment. The electrode's conductivity is approximately 200 S / cm, and after 15 days of continuous testing, the conductivity remained almost unchanged, demonstrating the electrode's stability. This characteristic ensures the electrode's reliability during long-term use and makes it suitable for continuous physiological signal monitoring.

[0027] In summary, compared with the prior art, the present invention has the following advantages: 1. The fabrication process is extremely simple, facilitating scalability and cost control: Using a solution-based spin coating method, electrode fabrication can be completed under mild conditions (110℃) based on a specific ratio of PEDOT:PSS and PEO. The entire process requires no complex photolithography or vacuum equipment, offers a wide process window and good repeatability, significantly reducing manufacturing and time costs, and laying the foundation for large-scale production applications.

[0028] 2. Hardware-level signal coupling for true synchronization and high fidelity: Analog circuitry (amplifier + adder) is used to directly couple the DC signal of body temperature with the AC signal of electromyography at the front end, outputting a single composite signal. This method avoids the inherent timing asynchrony and spatial mismatch problems of traditional multi-channel acquisition, achieving complete synchronization of the two signals in time and space, greatly facilitating backend data processing.

[0029] 3. Excellent mechanical flexibility and biological stability, suitable for long-term monitoring: The electrode body is a full polymer material system, which, when combined with a flexible PET substrate, exhibits excellent bending and fatigue resistance. Simultaneously, the material possesses good biocompatibility and electrochemical stability (experiments verify no conductivity decay within 15 days), ensuring continuous signal quality stability under long-term, dynamic wearing conditions, overcoming the shortcomings of traditional rigid electrodes or metal electrodes that are prone to failure and allergies.

[0030] 4. Excellent user experience and comfortable, imperceptible wear: Thanks to its ultra-thin (micron-level) characteristics, the electrodes can achieve highly conformal contact with the skin, with almost no foreign body sensation, greatly improving the user's wearing comfort and acceptance.

[0031] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A simplified electromyography and body temperature monitoring electrode system, characterized in that, Includes electrode module, processing module, and adder; The electrode module includes four flexible thin-film electrodes that are all attached to the skin surface. One flexible thin-film electrode is used to collect temperature signals, and the other three flexible thin-film electrodes are used to collect electromyographic signals at different locations. Two of the electromyographic signals are used as the raw electromyographic signals, and the other electromyographic signal is used as the reference electromyographic signal. The processing module uses a three-electrode method to process three electromyographic signals to obtain noise-reduced electromyographic signals; The adder is used to superimpose the temperature signal and the noise-reduced electromyography (EMG) signal to output a coupled signal, wherein the baseline amplitude of the coupled signal represents the temperature and the pulse sequence of the coupled signal represents the noise-reduced EMG signal.

2. The simplified electromyography and body temperature monitoring electrode system as described in claim 1, characterized in that, Including amplifiers; The amplifier is used to amplify the temperature signal, and then the amplified temperature signal is input into the adder.

3. The simplified electromyography and body temperature monitoring electrode system as described in claim 1, characterized in that, Each flexible thin-film electrode is an integrated structure coated with a composite conductive film on a flexible substrate, and the composite conductive film is made by mixing PEDOT:PSS and PEO in a mass ratio of 1:

2.

4. The simplified electromyography and body temperature monitoring electrode system as described in claim 3, characterized in that, The method for acquiring temperature signals using flexible thin-film electrodes is as follows: PEDOT:PSS in composite conductive films generates thermoelectric potential through the Seebeck effect when the temperature changes, and the temperature signal can be obtained by directly acquiring the thermoelectric potential.

5. A simplified electromyography and body temperature monitoring electrode system as described in claim 3 or 4, characterized in that, The thickness of the composite conductive film is between 250 nm and 350 nm, and the thickness of the flexible substrate is set according to the actual application requirements.

6. The simplified electromyography and body temperature monitoring electrode system as described in claim 1, characterized in that, The adder includes an operational amplifier, fixed resistors R1 and R2, a reference resistor Rf, and an adjustable resistor Ri; One end of the fixed resistor R1 is connected to the noise-reducing electromyography signal, and the other end is connected to the non-inverting input of the operational amplifier; one end of the fixed resistor R2 is connected to the temperature signal, and the other end is connected to the non-inverting input of the operational amplifier; one end of the reference resistor Rf is connected to the inverting input of the operational amplifier, and the other end is connected to the output of the operational amplifier; one end of the adjustable resistor Ri is connected to the inverting input of the operational amplifier, and the other end is grounded.

7. The simplified electromyography and body temperature monitoring electrode system as described in claim 1, characterized in that, The fabrication method of flexible thin-film electrodes is as follows: (1) Preparation of PEO solution: Dissolve PEO in DMF to prepare a solution with a concentration of 10 mg / mL; (2) Mixing PEDOT:PSS solution: Mix aqueous PEDOT:PSS solution with PEO solution at a mass ratio of 1:2 and stir for 2 hours to obtain composite electrode solution; (3) Substrate treatment: The PET substrate is subjected to oxygen plasma treatment for 3 minutes; (4) Spin-coating composite electrode solution: Spin-coating the composite electrode solution onto the treated PET substrate to obtain the electrode sample; (5) Heat treatment: Place the electrode sample on a hot plate and anneal at 110°C for 15 minutes; (6) Patterned electrode: The annealed electrode sample is cut into the required electrode shape using a laser cutter to obtain the final flexible thin film electrode.

8. The simplified electromyography and body temperature monitoring electrode system as described in claim 7, characterized in that, The spin coating time for the composite electrode solution was 20 seconds, and the spin speed was 1500 rpm.

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