Method for fabricating electromyographic / acoustomyographic bimodal stretchable device

Abstract

Embodiments of the present application provide a method for fabricating an electromyographic / acoustomyographic bimodal stretchable device. The method comprises: S1, fabricating a flexible stretchable electromyographic sensor using silica gel as the substrate and gold as the stretchable conductive material by means of thermal evaporation; and S2, integrating, on the basis of the fabricated flexible stretchable electromyographic sensor, a microphone with a multi-channel electromyographic electrode of the flexible stretchable electromyographic sensor by means of localized hardening and liquid metal connection, so as to complete the fabrication of the electromyographic / acoustomyographic bimodal stretchable device. The electromyographic electrode involved in the scheme of the present invention features flexibility and stretchability and is conformally adaptive to the skin to conduct stable electrophysiological signal monitoring. The involved device is flexible, stretchable, and conformally adaptive to the skin, so as to conduct stable in-situ synchronous monitoring of electromyographic and acoustomyographic bimodal signals.

Description

Preparation method of myoelectric and myoacoustic dual-modal stretchable device Technical Field

[0001] The embodiments of the present invention relate to the technical field of sensitive electronic components, and in particular to a method for preparing a myoelectric and myoacoustic dual-modal stretchable device. Background Art

[0002] Some medical diseases, such as muscular dystrophy and stroke, involve not only the failure of neural electrical signal conduction pathways, but also the failure of muscle activity responses. Therefore, when treating these diseases, it is necessary to monitor the human body's muscle activity.

[0003] On the one hand, surface electromyography (EMG) signals represent the superposition of electrical signals from multiple motor units in the body transmitted to the body surface. Monitoring surface electromyography signals helps to better understand muscle activity and neural control monitoring, and is of great significance in clinical diagnosis, rehabilitation assessment, and intelligent prosthetic control. On the other hand, acoustic myographs (AMG) originate from muscle vibrations caused by the friction of muscle fibers when the nerves control muscle contraction or relaxation. Monitoring acoustic myographs can provide a deep understanding of muscle activation patterns, force output, and fatigue levels, and can be used as a means to assess muscle function. However, monitoring of either electromyography or acoustic myographs alone cannot accurately determine the overall health of nerves and muscles. Only by simultaneously monitoring both modalities in the target area can the overall state of the nerves and muscles be fully reflected. Their combined monitoring can help detect lesions early and significantly improve diagnostic accuracy.

[0004] Although sensors for monitoring epidermal EMG and muscle sounds have been developed, devices for monitoring neuromuscular activity physiological information can only monitor a single physiological parameter in real time at a single location. Existing EMG electrodes and muscle sound sensors cannot achieve in-situ simultaneous acquisition of dual-modal signals. Even if single-channel EMG electrodes and single-channel microphones are integrated to achieve simultaneous acquisition of EMG and muscle sounds, the rigidity of the sensor as a whole can lead to slippage and detachment from the skin when detecting movements with large skin deformation, making signal artifacts difficult to remove. With the development of innovative flexible and stretchable conductive materials and microstructures, rigid electronic components can also achieve overall flexibility and stretchability through techniques such as localized hardening. This has largely enabled the flexible integration of multimodal physiological parameters, including temperature, heart rate, electrocardiogram (ECG), and humidity measurements. Currently, single-mode monitoring of EMG or AMG has been achieved. However, there is no research on dual-modal sensors integrating EMG and AMG in a flexible and stretchable form factor.

[0005] In summary, the existing technology has the following shortcomings:

[0006] (1) Commercial patch electrodes are not stretchable and are prone to slipping or even detaching from the skin when monitoring myoelectricity during large deformation movements, resulting in unstable or even lost signals.

[0007] (2) Hard sensors are difficult to match with human skin, causing motion artifacts and affecting signal quality.

[0008] (3) The information acquisition modality of flexible sensing is single and cannot perform in-situ multi-channel synchronous data acquisition for myoelectric and myoacoustic dual modalities.

[0009] Summary of the Invention

[0010] In view of this, an embodiment of the present invention provides a method for preparing a myoelectric and myoacoustic dual-modal stretchable device to at least partially solve the above problems.

[0011] According to a first aspect of an embodiment of the present invention, a method for fabricating a dual-mode stretchable myoelectric and myoacoustic device is provided, comprising: S1, using silicone as a substrate and gold as a stretchable conductive material via thermal evaporation to fabricate a flexible, stretchable myoelectric sensor; S2, integrating a microphone and the multi-channel myoelectric electrodes of the flexible, stretchable myoelectric sensor with the fabricated stretchable thin-film myoelectric sensor via localized hardening and liquid metal bonding, thereby completing the fabrication of the dual-mode stretchable myoelectric and myoacoustic device.

[0012] In one implementation, step S1 specifically includes: S101, mixing components A and B of Ecoflex-0020 liquid silicone in a ratio of 1:1 and vacuum degassing to obtain a mixture of Ecoflex-0020 liquid silicone; S102, spin-coating the mixture on an acrylic plate and letting it stand until solidified to form a silicone base; S103, placing a PET sheet with an electrode pattern on the silicone base; S104, covering a layer of gold on the film of the silicone base with the PET sheet by thermal evaporation technology to produce a multi-channel electromyographic electrode; S105, applying a layer of pressure-sensitive adhesive on the multi-channel electromyographic electrode to ensure safe adhesion to the skin, thereby completing the preparation of a flexible and stretchable electromyographic sensor.

[0013] In another implementation, step S1 further includes: spin-coating a layer of Ecoflex material on the multi-channel EMG electrode to insulate and protect the electrode while ensuring that the contact portion of the multi-channel EMG electrode is exposed.

[0014] In another implementation, step S2 specifically includes: S201, punching a hole on the back of the multi-channel electromyographic electrode to allow the myoacoustic signal to pass through; S202, placing a PET sheet on the back film of the silicone substrate, and uniformly processing the liquid metal to form a conductive line; S203, fixing the ICS-40300 microphone at a designated position of the flexible stretchable electromyographic sensor using Dow Corning 734 to complete the preparation of the myoacoustic and myoelectric dual-modal stretchable device.

[0015] In another implementation, step S2 further includes: spin-coating a layer of Ecoflex material on the surface of the myoelectric and myoacoustic dual-modal stretchable device to insulate and protect the liquid metal wire.

[0016] In another implementation, the thickness of the silicone substrate is 200 μm.

[0017] Compared with the prior art, the beneficial effects of the solution of the present invention are:

[0018] (1) Compared with commercial patch electrodes, the myoelectric electrodes of the present invention are soft and stretchable, can conform to the skin and move with it, and can stably monitor electrophysiological signals.

[0019] (2) Compared with existing dual-modal sensors, the device involved in the solution of the present invention is soft and stretchable as a whole, can conformally follow the skin, and can stably perform in-situ synchronous monitoring of myoelectric and myoacoustic dual-modal signals. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the embodiments of the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0021] FIG1 is a flowchart of the steps of a method for preparing a myoelectric and myoacoustic dual-modal stretchable device according to an embodiment of the present invention.

[0022] FIG2 is a specific operational flow chart of a method for preparing a myoelectric and myoacoustic dual-modal stretchable device according to another embodiment of the present invention.

[0023] FIG3 is a specific operational flow chart of a method for preparing a myoelectric and myoacoustic dual-modal stretchable device according to another embodiment of the present invention.

[0024] FIG4 is a distribution diagram of rigid dual-modal electromyographic and myoacoustic monitoring points in a method for preparing an electromyographic and myoacoustic dual-modal stretchable device according to another embodiment of the present invention.

[0025] Figure 5a shows images of the existing non-stretchable dual-modal sensor (i, ii) and the present invention (iii, iv) attached to the neck before and after exercise.

[0026] Figure 5b is the amplitude and time-frequency diagram of the existing non-stretchable dual-modal sensor and the monitored electromyographic and myoacoustic signals (electromyographic channel 11 and myoacoustic channel 4) on the left side of the neck.

[0027] FIG5 c is an amplitude and time-frequency diagram of the myoelectric and myoacoustic signals (the 11th channel of myoelectricity and the 4th channel of myoacousticity) of the left side of the neck monitored by the present invention.

[0028] FIG5 d is a diagram showing the amplitude distribution of the myoelectric signals and myoacoustic signals on the left and right sides of the neck when the present invention turns left.

[0029] Figure 5e shows the RMS values ​​of the myoelectric and myoacoustic signals of the monitoring channels in the circled positions of the present invention when turning right and left (left side: myoelectric channels 9, 10, 13, 14 and myoacoustic channel 3; right side: myoelectric channels 1, 2, 5, 6 and myoacoustic channel 1). DETAILED DESCRIPTION

[0030] In order to have a clearer understanding of the technical features, purposes and effects of the embodiments of the present invention, specific implementation methods of the embodiments of the present invention are now described with reference to the accompanying drawings.

[0031] In this document, “exemplary” means “serving as an example, instance or illustration”, and any illustration or implementation described as “illustrative” in this document should not be interpreted as a more preferred or more advantageous technical solution.

[0032] To simplify the drawings, only the parts relevant to the present invention are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, to simplify the drawings and facilitate understanding, in some figures, only one or more components with the same structure or function are schematically depicted or labeled.

[0033] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments in the embodiments of the present invention should fall within the scope of protection of the embodiments of the present invention.

[0034] The specific implementation of the embodiment of the present invention is further described below with reference to the accompanying drawings of the embodiment of the present invention.

[0035] FIG1 is a flowchart of a method for preparing a myoelectric and myoacoustic dual-mode stretchable device according to an embodiment of the present invention, which mainly includes:

[0036] Step S1: using silica gel as a substrate and gold as a stretchable conductive material by thermal evaporation technology to prepare a flexible and stretchable electromyographic sensor;

[0037] Step S2: Based on the manufactured stretchable thin film electromyographic sensor, the microphone and the multi-channel electromyographic electrodes of the flexible stretchable electromyographic sensor are integrated through local hardening and liquid metal connection to complete the preparation of the electromyographic and myoacoustic dual-modal stretchable device.

[0038] Compared with the prior art, the beneficial effects of the solution of the present invention are:

[0039] (1) Compared with commercial patch electrodes, the myoelectric electrodes of the present invention are soft and stretchable, can conform to the skin and move with it, and can stably monitor electrophysiological signals.

[0040] (2) Compared with existing dual-modal sensors, the device involved in the solution of the present invention is soft and stretchable as a whole, can conformally follow the skin, and can stably perform in-situ synchronous monitoring of myoelectric and myoacoustic dual-modal signals.

[0041] In one implementation, referring to FIG2 , step S1 specifically includes:

[0042] Step S101, mixing components A and B of Ecoflex-0020 liquid silicone rubber in a ratio of 1:1 and vacuum degassing to obtain a mixture of Ecoflex-0020 liquid silicone rubber;

[0043] Step S102: Spin-coat the mixture onto an acrylic plate and allow it to stand until solidified to form a silicone base;

[0044] Step S103: placing the PET sheet with the electrode pattern on the silicone substrate;

[0045] Step S104: Covering a layer of gold onto the thin film of the silicone substrate on which the PET sheet is placed by thermal evaporation technology to produce a multi-channel myoelectric electrode;

[0046] Step S105: Apply a layer of pressure-sensitive adhesive on the multi-channel EMG electrode to ensure safe adhesion to the skin, thereby completing the preparation of the flexible and stretchable EMG sensor.

[0047] In another implementation, step S1 further includes: spin-coating a layer of Ecoflex material on the multi-channel EMG electrode to insulate and protect the electrode while ensuring that the contact portion of the multi-channel EMG electrode is exposed.

[0048] In another implementation, referring to FIG3 , step S2 specifically includes:

[0049] Step S201: drilling a hole on the back of the multi-channel electromyographic electrode to allow myoacoustic signals to pass through;

[0050] Step S202: placing a PET sheet on the back film of the silicone substrate and uniformly treating the liquid metal to form conductive lines;

[0051] It should be understood that the introduction of liquid metal enables flexible and stretchable wires with low resistance.

[0052] Step S203: Fix the ICS-40300 microphone at a designated position of the flexible stretchable electromyographic sensor using Dow Corning 734 to complete the preparation of the myoelectric and myoacoustic dual-modal stretchable device.

[0053] It should be understood that the introduction of Dow Corning 734 enables the combination of low-modulus flexible stretchable electrodes and microphones to realize the preparation of myoelectric and myoacoustic dual-modal sensors, and realizes the combination of hard sensors and flexible sensors, thereby achieving the purpose of improving comfort.

[0054] In another implementation, step S2 further includes: spin-coating a layer of Ecoflex material on the surface of the myoelectric and myoacoustic dual-modal stretchable device to insulate and protect the liquid metal wire.

[0055] In another implementation, the thickness of the silicone substrate is 200 μm.

[0056] The following experiments were performed to verify the solution of the present invention:

[0057] Taking into account the high stretchability of the device involved in the present invention, it is very suitable for dynamic dual-modal monitoring of human skin subjected to large strain. The neck usually produces large deformation during daily movement, which is difficult for non-stretchable electrodes to operate. In this regard, the dual-modal signals during neck movement monitored by the non-stretchable dual-modal sensor and the myoelectric and myoacoustic dual-modal stretchable device involved in the present invention were studied. The results are shown in Figures 5a, 5b, 5c, 5d, and 5e, respectively. A purchased 64-channel commercial polyimide electrode was selected as the non-stretchable substrate, and 4 muscle sound acquisition microphones were integrated. The specific channel distribution is shown in Figure 4.

[0058] Sixteen channels were selected to verify functionality during exercise. In Figure 5a, during large movements such as neck rotation, the sensor separated from the skin due to the non-stretchability of existing devices, causing severe pain in the subject. In contrast, the stretchable dual-modal sensor of the present invention can deform appropriately with the deformation of the skin, ensuring not only comfort but also simultaneous acquisition of myoelectric and acoustic signals throughout the entire exercise process.

[0059] The recorded electromyographic signals and myoacoustic signals are shown in Figure 5b and Figure 5c, respectively, which show and analyze the amplitude and corresponding frequency of the dual-modal signals (electromyographic channel 11 and myoacoustic channel 4) obtained during the right turn over time. For non-stretchable PI-based sensors, motion artifacts are difficult to eliminate. The scheme of the present invention has the characteristics of being conformal and adaptive to the skin, and exhibits different waveforms and time-frequency characteristics in their respective frequency bands. This result proves that the scheme of the present invention has good signal acquisition performance when facing skin deformation.

[0060] The solution of the present invention can reliably collect 16 channels of electromyographic signals and 4 channels of acoustic muscle signals during large neck deformations. Synchronous data acquisition enables subsequent data analysis to understand muscle activation. The amplitude distribution of a complete neck rotation is shown in Figure 5d. The electromyographic and acoustic muscle signals demonstrate matching muscle activation states. When the neck turns to the left, the muscles on the left side of the neck relax, while the muscles on the right side become activated.

[0061] To further analyze the relationship between EMG and myoacoustic signals, we selected signals from symmetrical positions for investigation. As shown in the inset of Figure 5e, when the neck is turned to the right, the muscles on the left side are activated while those on the right side are relaxed, resulting in higher root mean square (RMS) values ​​of the EMG and myoacoustic signals on the left side than on the right side. The reverse is also true. There is a strong correlation between the EMG and myoacoustic signals, indicating that these signals can effectively reflect the active state of the muscles.

[0062] In summary, after experiments and use, the solution of the present invention has obtained stable dual-modal monitoring results of myoelectricity and muscle sound.

[0063] The solution involved in the present invention realizes the stability, softness and stretchability of the device, the functional integration of dual modality, and the in-situ synchronous acquisition of multi-channel dual modality signals, and can be used to monitor the electromyographic and myoacoustic dual modality signals on any skin surface.

[0064] It should be pointed out that, according to the needs of implementation, the various components / steps described in the embodiments of the present invention can be split into more components / steps, or two or more components / steps or partial operations of components / steps can be combined into new components / steps to achieve the purpose of the embodiments of the present invention.

[0065] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0066] The above implementation methods are only used to illustrate the embodiments of the present invention, and are not intended to limit the embodiments of the present invention. Ordinary technicians in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the embodiments of the present invention. Therefore, all equivalent technical solutions also fall within the scope of the embodiments of the present invention, and the scope of patent protection of the embodiments of the present invention should be defined by the claims.

Claims

1. A method for preparing an electromyogram and electromyophone dual-modal stretchable device, characterized in that, Including: S1. Using silicone as the substrate, gold is used as the stretchable conductive material by thermal evaporation technology to prepare a flexible and stretchable electromyography sensor; S2. Based on the manufactured stretchable thin-film electromyography sensor, the microphone and the multi-channel electromyography electrodes of the flexible and stretchable electromyography sensor are integrated through local hardening and liquid metal connection to complete the preparation of the electromyography and myoacoustic dual-modal stretchable device.

2. The method according to claim 1, characterized in that, Step S1 specifically includes: S101. Mix the A and B components of Ecoflex-0020 liquid silicone in a ratio of 1:1 and perform vacuum degassing to obtain a mixture of Ecoflex-0020 liquid silicone; S102. Spin-coat the mixture on an acrylic plate and let it stand until cured to form a silicone substrate; S103. Place the PET sheet with electrode patterns on the silicone substrate; S104. Cover a layer of gold on the film of the silicone substrate on which the PET sheet is placed through thermal evaporation technology to produce multi-channel electromyography electrodes; S105. Coat a layer of pressure-sensitive adhesive on the multi-channel electromyography electrodes to ensure safe adhesion to the skin, thereby completing the preparation of the flexible and stretchable electromyography sensor.

3. The method according to claim 2, characterized in that, Step S1 also includes: Spin-coat a layer of Ecoflex material on the multi-channel electromyography electrodes to insulate and protect the electrodes, while ensuring that the contact parts of the multi-channel electromyography electrodes are exposed.

4. The method according to claim 1, characterized in that, Step S2 specifically includes: S201. Drill holes in the back of the multi-channel electromyography electrodes to allow myoacoustic signals to pass through; S202. Place the PET sheet on the back film of the silicone substrate and uniformly process the liquid metal to form a conductive wire; S203. Fix the ICS-40300 microphone at the designated position of the flexible and stretchable electromyography sensor through Dow Corning 734 to complete the preparation of the electromyography and myoacoustic dual-modal stretchable device.

5. The method according to claim 4, characterized in that, Step S2 also includes: Spin-coat a layer of Ecoflex material on the surface of the electromyography and myoacoustic dual-modal stretchable device to insulate and protect the liquid metal wires.

6. The method according to any one of claims 1-5, characterized in that, The thickness of the silicone substrate is 200μm.

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