Flexible wearable mechanical force-physiological electricity multi-mode sensing system

Abstract

The invention relates to a flexible wearable mechanical force-physiological electricity multi-mode sensing system, which comprises a flexible wearable multi-mode sensor, a data acquisition and processing module and an upper computer, and is characterized in that the multi-mode sensor is attached to the muscle, needing to be measured, of a human body and is in wired connection with the data acquisition and processing module through a coaxial line; the data acquisition circuit board is connected with the upper computer in a wired or wireless manner; according to the multi-mode sensor, the same PVDF-HFP / [EMIm] NTf2 ionic gel material system is used, and a porous ion fiber membrane used for pressure sensing and a compact ion film used for myoelectricity acquisition are respectively formed through differential preparation processes; the ion fiber membrane is used as a sensing layer material of the sensing electrode, and the compact ion film is used as a sensing layer material of the shared electrode, the reference electrode and the ground electrode. The flexible wearable multi-mode sensor is attached to the detected skin and can measure surface myoelectricity, surface muscle pressure and muscle tremor signals at the same position at the same time.

Description

Technical Field

[0001] This invention belongs to the field of medical rehabilitation sensor technology and relates to a flexible wearable mechanical force-physiological electrical multimodal sensing system. Background Technology

[0002] In the field of medical rehabilitation, human motor function is closely related to muscle status. Muscle status detection can be used to assess muscle function and strength, and can be applied to evaluate muscle contraction and relaxation function, local muscle fatigue, and muscle endurance in medical rehabilitation or sports. The mechanical and electrical signals generated by muscle activity are key indicators of muscle health. Surface electromyography (sEMG) is a widely used method for assessing muscle function; it measures the bioelectric current generated by surface muscles during contraction. It reflects the degree of skeletal muscle activation and is related to muscle strength. However, sEMG is not sensitive to the passive tension and subsequent work generated by the muscle-tendon unit (MTU), and the relationship between sEMG and force is affected by various factors, such as muscle length, fatigue, and elastic properties. Muscle mechanical signals, such as surface muscle pressure (SMP) and myosometry (MMG), provide valuable information on muscle mechanical behavior, while sEMG has limitations in these areas. Electromyographic signals and mechanical force signals characterize the neural drive and contractile function of muscles, respectively, and their synergistic analysis can provide a more comprehensive basis for muscle status assessment. Therefore, simultaneously measuring the electromyographic and mechanical force signals of muscles is of great significance for muscle status detection.

[0003] However, integrating mechanical force sensors with electrophysiological sensors remains a key challenge. To date, multimodal sensors measuring mechanical pressure and physiological electrical signals can only be achieved through the traditional method of combining various sensing elements into a single system (using a "heterogeneous integration" approach, where sensing elements with different functions and materials (such as independent pressure sensing units and independent electromyographic electrodes) are physically assembled onto a single system or substrate). For example, patents CN202310966759.4 (A robot control method based on multimodal signal motion intention recognition), CN202410044445.3 (A knee joint static progressive stretching trainer with integrated signal detection system), and CN202311291357.5 (A system and method for acquiring surface electromyography and muscle deformation information at the same point) all integrate two sets of sensing elements into a single system. However, sensors manufactured using this traditional method typically require multiple materials to heterogeneously integrate different components, resulting in several drawbacks, including complex manufacturing processes, portability difficulties, unsuitability for wearable devices, and difficulties in matching measurement data. Furthermore, the interfaces between different materials are prone to premature damage due to inherent mechanical property mismatches, especially when the human body deforms, severely affecting the stability of wearable devices. Therefore, it is crucial to develop a flexible, simple, multimodal sensing system capable of simultaneously acquiring mechanical force and physiological electrical signals at the same location. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the technical problem this invention aims to solve is to provide a flexible, wearable, simple-structured, multimodal sensing system capable of simultaneously measuring subcutaneous muscle mechanical force and physiological electrical activity at the same location. The flexible wearable multimodal sensor is attached to the skin being tested and can simultaneously measure surface electromyography, surface muscle pressure, and muscle tremor signals at the same location.

[0005] The technical solution of the present invention to solve the aforementioned technical problem is, In a first aspect, the present invention provides a flexible wearable mechanical force-physiological electrophysiological multimodal sensing system, including a flexible wearable multimodal sensor, a data acquisition and processing module and a host computer. The multimodal sensor is attached to the muscle of the human body that needs to be measured and is connected to the data acquisition and processing module via a coaxial wire. The data acquisition circuit board is connected to the host computer via a Type-C wired or wireless method. The multimodal sensor uses the same PVDF-HFP / [EMIm]NTf2 ion gel material system, and through differentiated preparation processes, it forms a porous ion fiber membrane for pressure sensing and a dense ion membrane for electromyography acquisition, respectively. Ion-fiber membranes are used as the sensing layer material for the sensing electrode SE, and dense ion-membrane films are used as the sensing layer material for the shared electrode C-DE, the reference electrode REF, and the ground electrode GND. The sensing electrode SE and the shared electrode C-DE are used for pressure measurement, while the shared electrode C-DE, the ground electrode GND, and the reference electrode REF are used for measuring surface electromyography signals, with the shared electrode serving as a common electrode for the two measurements.

[0006] Furthermore, the ion-fiber membrane adopts a coating-nonwoven fabric loading-drying process to form a porous and easily deformable structure, achieving high-sensitivity pressure sensing; the dense ion-film adopts a spin coating-plasma pretreatment substrate-drying process to form a flat and dense interface, achieving low impedance and high-stability electromyography signal acquisition.

[0007] Furthermore, in the PVDF-HFP / [EMIm]NTf2 ionogel material system, the mass ratio of PVDF-HFP, [EMIm]NTf2, and DMAC is 1:1:5-15.

[0008] Furthermore, the preparation process of the ion-exchange fiber membrane is as follows: the gel solution is quantitatively coated onto a polyester nonwoven fabric, with a coating amount of 20-50 g / m². 2 Through the action of nonwoven fiber template, it is vacuum dried at 70-90℃ for 12-24 hours to form an open porous fiber network structure with high specific surface area; The preparation process of dense ion exchange films is as follows: spin-coating the gel solution onto a plasma-treated glass plate at a speed of 200-500 r / min for 60-90 seconds; then vacuum drying at 70-90℃ for 12-24 hours, during which the solvent slowly and completely evaporates, forming a film with an extremely smooth surface, dense interior, and few defects.

[0009] Furthermore, the principle of the data acquisition and processing module is as follows: Pressure signal acquisition: Using the capacitive voltage divider principle, a specific frequency AC excitation signal is applied to the circuit between the sensing electrode SE and the shared electrode C-DE. The pressure magnitude is reflected by detecting the change in capacitance or impedance of the circuit. This capacitance change originates from the change in double-layer capacitance caused by the change in the contact area between the ion fiber membrane and the skin due to pressure. Physiological electromyography signal acquisition: The differential amplification principle is adopted. The shared electrode C-DE and the reference electrode REF are used as the two input terminals of the differential amplifier to acquire weak surface electromyography signals. The ground electrode GND provides a reference ground for the circuit. The acquired signals are amplified and filtered, and then digitized by the analog-to-digital converter ADC. Signal isolation: Isolation measures are taken in the circuit to ensure that the pressure excitation signal does not interfere with the electromyographic signal.

[0010] Furthermore, the isolation measures include selecting the frequency of the pressure excitation signal outside the effective frequency band of the electromyography signal, or setting a notch filter on the electromyography signal acquisition path to filter out the excitation frequency component.

[0011] Secondly, this invention provides a flexible wearable multimodal sensor, comprising electrodes, sensing materials, and a flexible substrate. The electrodes include a sensing electrode SE, a shared electrode C-DE, a ground electrode GND, and a reference electrode REF. An ion-exchange fiber membrane is used as the sensing layer material for the sensing electrode SE, and a dense ion-exchange thin film is used as the sensing layer material for the shared electrode C-DE, the reference electrode REF, and the ground electrode GND. The sensing electrode SE and the shared electrode C-DE are used for pressure measurement, while the shared electrode C-DE, the ground electrode GND, and the reference electrode REF are used for measuring surface electromyography signals. The shared electrode serves as a common electrode for both measurements. All electrodes use the same basic sensing material system, which combines low electronic impedance with good mechanical flexibility, enabling it to collect bioelectrical signals as a low-noise electrode and to achieve pressure sensing based on its pressure-sensitive characteristics. The basic sensing material system is formed by a coating-nonwoven fabric loading-drying process to create an ion-exchange fiber membrane. The basic sensing material system is formed by a spin-coating-plasma pretreatment of the substrate-drying process to create a dense ion-exchange thin film.

[0012] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention proposes a sensor integration strategy that simultaneously utilizes electrodes that can be directly applied to the skin—skin electrodes and shared electrodes—to achieve synchronous, in-situ, and quantitative measurement of multimodal muscle signals—surface electromyography, surface muscle pressure, and muscle tremor signals—using a single sensitive material. The solid electrolyte material (sensitive material) in this invention possesses both low electronic impedance and good mechanical flexibility. It can serve as a low-noise electrode for acquiring bioelectrical signals and also achieve pressure sensing based on its pressure-sensitive properties. This makes the thin film more suitable for dual-mode detection requirements in terms of impedance and mechanical properties, rather than single-mode pressure signal measurement.

[0013] 2. The multimodal sensor of this invention uses only one sensitive material to acquire various signals, and it exhibits excellent electrophysiological and mechanical measurement performance. This invention employs a "homogeneous-heterogeneous" sensing layer: all electrodes use the same basic sensitive material system (PVDF-HFP / [EMIm]NTf2 ion gel), but are prepared in two forms according to functional requirements: ion-fiber membrane: used for the sensing electrode, utilizing its porous and deformable characteristics for pressure sensitivity; ion-film: used for the shared electrode, reference electrode, and ground electrode, utilizing its smooth surface and stable interface to provide low-impedance, high-stability contact for electromyography measurements. The electrophysiological signals acquired by the multimodal sensor have a high signal-to-noise ratio (SNR, 27.4 dB) and reusability; the acquired mechanical signals have a low detection limit (~25 Pa), a wide pressure range (0-320 kPa), a fast response time (~15 ms), and high linearity (R-squared approximately 0.99).

[0014] 3. The pressure sensing portion of the multimodal sensor of this invention uses parallel electrodes attached to the skin, enabling simultaneous measurement of surface muscle pressure and muscle tremor signals. Unlike the multi-layered structure of traditional pressure sensors, this structure, due to the direct contact between the sensing material and the skin, can more accurately capture muscle pressure and tremor signals. Therefore, the muscle tremor signal can be obtained from the pressure signal through high-pass filtering, without the need for additional measurement equipment.

[0015] 4. This multimodal sensor can be used to diagnose previously difficult-to-measure muscle diseases (such as Parkinson's disease and dystonia) because they require simultaneous measurement of mechanical and electrophysiological signals at the same location. This invention proposes a shared electrode strategy, which integrates two sensing structures into a single sensor, achieving co-location detection. The invention employs a "shared electrode" hardware architecture: in terms of hardware connection, the shared electrode is simultaneously connected to two different measurement circuits: one forms a pressure sensing loop together with the sensing electrode; the other forms a differential input loop for surface electromyography (sEMG) signal acquisition together with the reference electrode and the ground electrode.

[0016] 5. The multimodal sensor in this invention simplifies the monitoring process, eliminating the need for multiple wearable devices. Traditional methods involving multiple devices suffer from drawbacks such as complex setup, asynchronous recording, and spatial discrepancies between measurement locations.

[0017] 6. Compared with other multimodal flexible sensors developed through research, this sensor has advantages such as simple preparation process, easy installation, and reusability. In terms of electrophysiological acquisition performance, this sensor can maintain signal quality during multiple acquisitions and long-term acquisition processes.

[0018] 7. In terms of pressure signal acquisition, the distance between the sensing electrode SE and the shared electrode C-DE has a negligible impact on pressure sensing performance, and can be flexibly used as a skin device or a textile-based wearable device.

[0019] In summary, this invention presents a highly integrated flexible wearable multimodal sensor capable of simultaneously acquiring surface electromyography (sEMG), surface muscle pressure (SMP), and mechanomyography (MMG) using a single sensing material, with each signal spatially corresponding. It directly addresses key limitations of existing multimodal systems, including spatial misalignment, temporal asynchrony, bulky mechanical size, and complex assembly. This invention reduces the structural complexity of EMG and mechanomyography measurement systems, decreases the number of sensing modules in multimodal measurements, overcomes the need for different sensor probes in hybrid electrode measurements of EMG and pressure signals, ensures temporal and spatial synchronization of EMG and pressure signals, and achieves modularity and integration of the EMG-pressure multimodal measurement system. These comprehensive breakthroughs enable this sensor to achieve robust, high-resolution neuromechanical monitoring in dynamic motion, fatigue assessment, and clinical rehabilitation scenarios, and it has broad application prospects in rehabilitation robots, neural prostheses, and human-computer interaction. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the flexible wearable multimodal sensing system of the present invention; Figure 2 This is a schematic diagram of the structure of the multimodal sensor of the present invention; in the figure: 1, FPC flexible substrate; 2, sensing electrode; 3, shared electrode; 4, reference electrode; 5, ground electrode; 6, ion fiber membrane; 7, ion film.

[0021] Figure 3 This is a schematic diagram of the mechanical force-physiological electrosensing principle of the multimodal sensor of the present invention; Figure 4 This is a schematic diagram of the data acquisition and processing module of the multimodal sensor of the present invention; Figure 5 This is a measurement signal diagram of the multimodal sensor in the embodiment under different load movements of the biceps brachii, including electromyographic signals, surface muscle pressure signals and muscle vibration signals. Detailed Implementation

[0022] Specific embodiments of the present invention are given below. These specific embodiments are only used to further illustrate the present invention and do not limit the scope of protection of this application.

[0023] This invention can simultaneously measure electromyographic (EMG) and mechanical force signals of muscles. Surface electromyography (sEMG), surface myoelectric potential (SMP), and mechanical electromyography (MMG) provide different but interdependent information: sEMG reflects neural activation, SMP captures overall muscle tension, and MMG indicates mechanical vibration. This integrated measurement method has been further validated in physiological scenarios. For example, when neuromuscular signal transmission is blocked (e.g., via botulinum toxin), muscle movement may cease, but residual electrical activity can still be detected. Conversely, in passive muscle movement in healthy individuals, changes in muscle tension may occur without surface EMG activity. These examples highlight the necessity of multimodal measurement to fully capture the complexity of neuromechanical interactions while leveraging the complementary robustness of mechanical (SMP / MMG) and electrical (sEMG) sensing. The sensing material used in the electrodes of this invention possesses "dual-function" characteristics, capable of efficiently measuring weak electrophysiological signals (requiring low impedance and good ion-electric contact) and sensitively responding to mechanical pressure signals (requiring elasticity and piezoresistive / piezoresistive characteristics), achieving effective acquisition of both signals.

[0024] This invention innovatively proposes a shared electrode strategy and a homogeneous heterogeneous process. Using the same PVDF-HFP / [EMIm]NTf2 ion gel material system, differentiated preparation processes are employed to form a porous ion-fiber membrane 6 for pressure sensing and a dense ion-film 7 for electromyography (EMG) acquisition, thereby achieving true synchronous, in-situ, and integrated multimodal signal acquisition, overcoming the fundamental shortcomings of existing technologies. Specifically: Shared electrode hardware architecture: The shared electrode serves as a common node for both the pressure sensing circuit and the electromyography differential input circuit, ensuring spatial overlap and temporal synchronization.

[0025] Homogeneous sensing layer process: All electrode interface materials are PVDF-HFP / [EMIm]NTf2 ionogels, but through differentiated preparation processes, two functional forms are formed: Ion fiber membrane (for sensing electrode SE): It adopts a coating-nonwoven fabric loading-drying process to form a porous and easily deformable structure, so as to achieve high-sensitivity pressure sensing.

[0026] Dense ion-exchange thin film (for shared electrode C-DE, reference electrode REF, and ground electrode GND): A spin-coating-plasma pretreatment substrate-drying process is used to form a flat and dense interface, enabling low impedance and highly stable electromyography signal acquisition.

[0027] The originality of the process of this invention is reflected in: Solvent system optimization: Dimethylacetamide (DMAC) was selected as the solvent. DMAC has a higher boiling point and stability, and solvent evaporation is more controllable during the subsequent drying process, which is conducive to the formation of a more uniform film structure with fewer defects, while also improving process safety.

[0028] Precise formulation control: The optimal ratio of PVDF-HFP, [EMIm]NTf2, and DMAC was determined to be 1:1:5-15. This ratio, after systematic optimization, balances ionic conductivity, mechanical flexibility, and film-forming processability, and is the basis for simultaneously achieving two functional forms.

[0029] Differentiated film formation processes: Ion-ion fiber membrane: The gel solution is quantitatively coated onto a polyester nonwoven fabric (20-50 g / m²). 2 Through the action of nonwoven fiber templates and specific conditions of vacuum drying at 70-90℃ for 12-24 hours, an open, porous fiber network structure with a high specific surface area is formed. This structure exhibits significant changes in contact area under pressure and has a sensitive capacitive response.

[0030] Dense ion exchange membrane: The gel solution is spin-coated onto a plasma-treated glass plate at 200-500 r / min for 60-90 seconds. Plasma treatment enhances the hydrophilicity of the substrate, and combined with the shear force of spin coating, the solution spreads extremely uniformly. After vacuum drying at 70-90℃ for 12-24 hours, the solvent slowly and completely evaporates, forming a membrane with an extremely smooth surface, dense interior, and few defects. This structure provides stable ion channels, low electrode-skin interface impedance, and low noise.

[0031] Targeted design of functional forms: This invention intentionally uses the same formulation solution to prepare two forms specifically for pressure sensitivity (porous fiber membrane) and for electrical signal acquisition (dense thin film) through two completely different process paths. This is a key process innovation to achieve "shared electrode dual function" and "homogeneous heterogeneous" integration.

[0032] This invention relates to a flexible wearable mechano-physioelectric multimodal sensing system, which is a multimodal sensing system that can be attached to the skin to simultaneously collect mechano-force and physiological electrical signals in the same muscle region. It includes a flexible wearable multimodal sensor (hereinafter referred to as a multimodal sensor or sensor), a data acquisition and processing module, and a host computer, such as... Figure 1 As shown.

[0033] The multimodal sensor comprises four electrodes: a sensing electrode (SE) 2, a shared electrode (C-DE) 3, a ground electrode (GND) 5, and a reference electrode (REF) 4. Each electrode is attached with sensing materials (6 and 7). The sensing electrode uses ion-exchange fiber membrane sensing material, while the shared electrode, ground electrode, and reference electrode use ion-exchange membrane sensing material. The sensing electrode SE and the shared electrode C-DE are used for pressure measurement, while the shared electrode C-DE, ground electrode GND, and reference electrode REF are used to measure surface electromyography (EMG) signals. The shared electrode serves as a common electrode for the two measurements. Figure 2 As shown; the multimodal sensor is connected to the data acquisition and processing module, which is used to acquire and process the pressure signal and physiological electrical signal of the sensor; the data acquisition and processing module transmits data to the host computer via a USB signal data transmission cable or wirelessly.

[0034] The pressure sensing principle of the multimodal sensor of this invention utilizes the ionic conductivity of the ion-fiber membrane (a solid polymer electrolyte material) prepared in this invention and the skin. Its mechanical force sensing part is configured as an electrode-solid polymer electrolyte-skin structure. This structure creates an electric double layer between the electrode and the skin. When the sensor is subjected to pressure, the contact area between the ion-fiber membrane and the skin increases, leading to the displacement of more electrodes with opposite charges (cations and anions), thus increasing the sensor's measuring capacitance. Figure 3 As shown, its capacitance is proportional to the interfacial contact area between the electrode, the ion-fiber membrane, and the skin. Furthermore, this invention utilizes the mechanical stability and high-frequency, low-impedance properties of solid polymer electrolytes, selecting this material as the electrode material for long-term stable measurement of electrophysiological signals.

[0035] The principle of the data acquisition and processing module is as follows: Pressure signal acquisition: Utilizing the capacitive voltage divider principle. A specific frequency AC excitation signal is applied to the circuit between the sensing electrode (SE) and the shared electrode (C-DE). The pressure magnitude is reflected by detecting changes in the capacitance (or impedance) of this circuit. This capacitance change originates from the alteration of the double-layer capacitance caused by the change in the contact area between the ion-fiber membrane and the skin due to pressure.

[0036] Physiological electromyography (EMG) signal acquisition: Differential amplification is employed. The shared electrode (C-DE) and reference electrode (REF) serve as the two input terminals of the differential amplifier, acquiring weak surface EMG signals. The ground electrode (GND) provides a reference ground for the circuit. The acquired signal is amplified and filtered (typically including high-pass filtering to remove motion artifacts and band-pass filtering to extract characteristic EMG frequencies, such as 10-500 Hz), before being digitized by an analog-to-digital converter (ADC).

[0037] Signal isolation: To ensure that the pressure excitation signal does not interfere with the electromyographic signal, isolation measures are taken in the circuit. For example, the frequency of the pressure excitation signal is selected to be outside the effective frequency band of the electromyographic signal, or a notch filter is set on the electromyographic signal acquisition path to filter out the excitation frequency component.

[0038] Example 1 The fabrication process of the multimodal sensor of this invention is as follows: Electrode layer fabrication The flexible substrate portion of the sensor is fabricated using the FPC process, resulting in the FPC flexible substrate 1.

[0039] Preparation of ion-exchange fiber membranes and ion-exchange thin films for sensing materials (this invention uses dimethylacetamide (DMAC) as a solvent, which is more stable and safer. Two types of thin films were prepared: one is an ion-exchange thin film obtained by spin-coating the prepared solution, which is a dense ion-exchange thin film used for surface electromyography detection; the other is an ion-exchange fiber membrane obtained by coating the prepared solution onto non-woven fabric, which is a porous ion-exchange fiber membrane used for pressure detection): PVDF-HFP and 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([EMIm]NTf2) were sequentially added to a beaker containing a dimethylacetamide (DMAC) solution, wherein the mass ratio of PVDF-HFP, [EMIm]NTf2 and DMAC was 1:1:10. This setting was optimized to balance the ionic conductivity, mechanical properties and film quality of the materials. The beaker containing the mixed solution was placed in a thermostatically heated magnetic stirrer (DF-101S, Shanghai Bangxi Lichen Technology Co., Ltd.), with the oil bath heating temperature set to 80℃ and the rotor speed set to 300 rpm. Stir at r / min for 60 minutes to obtain a uniform PVDF-HFP / [EMIm]NTf2 ionogel solution.

[0040] Preparation of ion-exchange fiber membrane: The above ion-exchange gel solution was uniformly coated onto a membrane with a specification of 40 g / m² using a coating rod. 2 On a polyester fiber nonwoven fabric, the volume (ml) of the ion gel solution is related to the area (cm²) of the nonwoven fabric. 2 The ratio of solvent to ion-exchange fiber is controlled at approximately 1:3. This coating amount ensures that the solution fully impregnates the nonwoven fibers to form a porous structure. Subsequently, vacuum drying at 80°C for 24 hours allows the solvent to completely evaporate, resulting in a porous, flexible ion-exchange fiber membrane. This porous structure makes it easily deformable under pressure, with significant changes in contact area, thus achieving high pressure sensitivity.

[0041] Preparation of ion-coated thin films: An ion-gel solution was poured onto a clean glass plate treated with plasma, and then placed on a centrifugal coater and rotated at 200 r / min for 60 seconds to form a uniform thin film through spin coating. Finally, the solvent was removed by vacuum drying at 80℃ for 24 hours, resulting in a smooth and dense PVDF-HFP / [EMIm]NTf2 ion-coated thin film. This spin coating process and its parameters (rotation speed and time) are crucial for obtaining a low-impedance, high-stability interface.

[0042] Finally, the prepared ion-fiber membrane and ion-film were cut into 10 mm diameter circles using a punch to serve as the sensing layer. The sensor's four skin electrodes are divided into two categories: the sensing electrode (SE) is attached to the ion-fiber membrane sensing layer; while the shared electrode (C-DE), reference electrode (REF), and ground electrode (GND) are all attached to the ion-film sensing layer.

[0043] Sensor Packaging and Wearable The multimodal sensor has four circular electrodes, each 10 mm in diameter. Each electrode is led out to a coaxial cable with a 1 mm lead wire, and connected to the data acquisition and processing module via terminals on the coaxial cable. Figure 1 As shown.

[0044] The sensor's electrodes are attached to the belly of the muscle being measured.

[0045] Sensor wiring and data transmission The four leads of the four electrodes of the multimodal sensor are led out through a four-core coaxial cable and connected to the data acquisition and processing module through the terminal block at the end of the coaxial cable. The data is then transmitted to the host computer through the signal conditioning circuit and wireless module (or wired interface) in the data acquisition and processing module.

[0046] Host computer display On the host computer interface, after selecting the corresponding serial port and baud rate, clicking the start button will begin displaying the acquired multi-channel data. Additionally, selecting the file save path and clicking the "Save Data" button will begin storing the multi-channel electromyography and pressure signals; clicking again will complete the save. Both data reception and transmission use hexadecimal notation.

[0047] The format of the custom data packet for the data acquisition and processing module is shown in Table 1. Each frame of the custom data packet contains a 1-byte frame header plus a frame length of AAFF F130, eight 2-byte electromyography data points, eight 1-byte pressure data points, a 1-byte frame tail plus a checksum. The checksum calculation includes the frame header and frame tail, totaling 27 bytes.

[0048] Table 1. Data format of a frame of data

[0049] Figure 5The image shows the measurement signal diagrams of the multimodal sensor in the embodiment under different load movements of the biceps brachii, including electromyographic signals, surface muscle pressure signals and muscle vibration signals, with good signal quality.

[0050] The above-disclosed embodiments are merely specific examples of the present invention. However, the present invention is not limited thereto, and any variations that can be conceived by those skilled in the art should fall within the protection scope of the present invention.

[0051] Any aspects not covered in this invention are applicable to existing technologies.

Claims

1. A flexible wearable mechanomechanical-physiological electrophysiological multimodal sensing system, comprising a flexible wearable multimodal sensor, a data acquisition and processing module, and a host computer, characterized in that, The multimodal sensor is attached to the muscle on the human body that needs to be measured and is connected to the data acquisition and processing module via a coaxial cable. The data acquisition circuit board is connected to the host computer via a wired or wireless means. The multimodal sensor uses the same PVDF-HFP / [EMIm]NTf2 ion gel material system, and through differentiated preparation processes, it forms a porous ion fiber membrane for pressure sensing and a dense ion membrane for electromyography acquisition, respectively. Ion-fiber membranes are used as the sensing layer material for the sensing electrode SE, and dense ion-membrane films are used as the sensing layer material for the shared electrode C-DE, the reference electrode REF, and the ground electrode GND. The sensing electrode SE and the shared electrode C-DE are used for pressure measurement, while the shared electrode C-DE, the ground electrode GND, and the reference electrode REF are used for measuring surface electromyography signals, with the shared electrode serving as a common electrode for the two measurements.

2. The system according to claim 1, characterized in that, The ion-fiber membrane adopts a coating-nonwoven fabric loading-drying process to form a porous and easily deformable structure, achieving high-sensitivity pressure sensing; the dense ion membrane adopts a spin coating-plasma pretreatment substrate-drying process to form a flat and dense interface, achieving low impedance and high-stability electromyography signal acquisition.

3. The system according to claim 1, characterized in that, In the PVDF-HFP / [EMIm]NTf2 ionogel material system, the mass ratio of PVDF-HFP, [EMIm]NTf2, and DMAC is 1:1:5-15.

4. The system according to claim 1, characterized in that, The preparation process of the ion-exchange fiber membrane is as follows: a gel solution is quantitatively coated onto a polyester nonwoven fabric, with a coating amount of 20-50 g / m². 2 Through the action of nonwoven fiber template, it is vacuum dried at 70-90℃ for 12-24 hours to form an open porous fiber network structure with high specific surface area; The preparation process of dense ion exchange films is as follows: spin-coating the gel solution onto a plasma-treated glass plate at a speed of 200-500 r / min for 60-90 seconds; then vacuum drying at 70-90℃ for 12-24 hours, during which the solvent slowly and completely evaporates, forming a film with an extremely smooth surface, dense interior, and few defects.

5. The system according to claim 1, characterized in that, The principle of the data acquisition and processing module is as follows: Pressure signal acquisition: Using the capacitive voltage divider principle, a specific frequency AC excitation signal is applied to the circuit between the sensing electrode SE and the shared electrode C-DE. The pressure magnitude is reflected by detecting the change in capacitance or impedance of the circuit. This capacitance change originates from the change in double-layer capacitance caused by the change in the contact area between the ion fiber membrane and the skin due to pressure. Physiological electromyography signal acquisition: The differential amplification principle is adopted. The shared electrode C-DE and the reference electrode REF are used as the two input terminals of the differential amplifier to acquire weak surface electromyography signals. The ground electrode GND provides a reference ground for the circuit. The acquired signals are amplified and filtered, and then digitized by the analog-to-digital converter ADC. Signal isolation: Isolation measures are taken in the circuit to ensure that the pressure excitation signal does not interfere with the electromyographic signal.

6. The system according to claim 5, characterized in that, The isolation measures include selecting the frequency of the pressure excitation signal outside the effective frequency band of the electromyography (EMG) signal, or setting a notch filter on the EMG signal acquisition path to filter out the excitation frequency component.

7. A flexible wearable multimodal sensor, comprising electrodes and sensing material, and a flexible substrate, characterized in that, The electrodes include a sensing electrode SE, a shared electrode C-DE, a ground electrode GND, and a reference electrode REF. An ion-exchange fiber membrane is used as the sensing layer material for the sensing electrode SE, and a dense ion-exchange thin film is used as the sensing layer material for the shared electrode C-DE, the reference electrode REF, and the ground electrode GND. The sensing electrode SE and the shared electrode C-DE are used for pressure measurement, while the shared electrode C-DE, the ground electrode GND, and the reference electrode REF are used for measuring surface electromyography signals. The shared electrode serves as a common electrode for both measurements. All electrodes use the same basic sensitive material system, which combines low electronic impedance with good mechanical flexibility. This system can be used as a low-noise electrode to collect bioelectrical signals and can also achieve pressure sensing based on its pressure-sensitive characteristics. The basic sensitive material system adopts a coating-nonwoven fabric loading-drying process to form an ion fiber membrane; the basic sensitive material system adopts a spin coating-plasma pretreatment substrate-drying process to form a dense ion film.

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