GB2587185A

GB2587185A - Surface electromyography apparatus

Info

Publication number: GB2587185A
Application number: GB1912990.7A
Authority: GB
Inventors: Rose Hepworth Isabel; Egerton Brian
Original assignee: Prevayl Ltd
Current assignee: Prevayl Ltd
Priority date: 2019-09-09
Filing date: 2019-09-09
Publication date: 2021-03-24
Anticipated expiration: 2039-09-09
Also published as: GB2587185B; GB201912990D0

Abstract

Surface electromyography (EMG) apparatus 1 provided as a transfer, the apparatus comprising an electrically conductive layer forming a first electrode 101 and a non-conductive ink layer 107 covering the conductive layer. The electrically conductive layer may form one or more electrical pathways 113, 115. A second electrode 103, forming a bipolar pair 100 may be provided between the first and a second non-conductive ink layer and the electrodes may form a nested arrangement. An opening may be provided in the ink layer for the electrode. The transfer may be applied to a wearable item such as a garment (400 figure 4). An adhesive layer (125 figure 2) may cover the non-conductive ink layer (107 figure 2). A method of manufacturing a surface EMG by printing electrically conductive ink onto a surface and covering it with non-conductive ink is also claimed. A method (figure 7) of applying a surface EMG transfer to a surface by applying heat or pressure to the transfer is also claimed.

Description

SURFACE ELECTROMYOGRAPHY APPARATUS

The present disclosure is directed towards a surface electromyography (EMG) apparatus, textile, garment and method of making the same. The present disclosure is directed, in particular, to surface EMG apparatus in the form of a transfer.

Background

Electromyography (EMG) is a well-known process for detecting and processing electrical signals generated by muscle activity. Surface EMG apparatuses use electrodes that are designed to rest on the surface of the skin and thus measure EMG signals externally. Surface EMG apparatuses contrast with intramuscular EMG apparatuses that are required to penetrate the skin and measure EMG signals from within the muscle tissue. Intramuscular EMG is generally limited to clinical setting and requires skilled application by a medical professional. By contrast, surface EMG is far less invasive and can be incorporated into wearable items such as smartwatches and garments to measure EMG signals of users wearing the wearable items over an extending period of time. Surface EMG apparatuses are generally more appropriate for non-clinical settings and uses.

Surface EMG apparatuses include resistive EMG apparatuses and capacitive EMG apparatuses. Resistive EMG apparatus typically require that the electrode of the EMG apparatus is in direct physical contact with the user's skin. By contrast, for capacitive EMG sensors, the electrode is typically electrically insulated from the user's skin by an intervening layer of dielectric material.

It is an objective of the present disclosure, to provide an improved or at least an alternative to existing resistive and capacitive surface EMG apparatuses, and in particular improve one or more of the flexibility, durability, and ease of manufacture of the surface EMG apparatus.

Summary

According to the present disclosure there is provided an surface EMG apparatus, textile, garment and method as set forth in the appended claims. Other features of the invention will be apparent from the dependent claims, and the description which follows.

According to a first aspect of the present disclosure, there is provided a surface electromyography, EMG, apparatus in the form of a transfer. The surface EMG apparatus comprises an electrically conductive layer comprising a first area forming a first electrode; and a first non-conductive ink layer covering the electrically conductive layer.

Beneficially, the surface EMG apparatus is provided in the form of a transfer. A non-conductive ink layer covers the electrically conductive layer. The non-conductive ink layer can be applied to a surface such as a textile so that the surface EMG apparatus may be incorporated into a wearable item. This enables the surface EMG apparatus to be easily applied to a variety of surfaces. The non-conductive ink layer separates and insulates the surface electrode from the textile.

The electrically conductive layer may further comprise a second area forming a first electrically conductive pathway extending from the first electrode.

The surface EMG apparatus may further comprise a second non-conductive ink layer. The first electrically conductive pathway may be provided between the first and second non-conductive ink layers. The electrically conductive layer may be provided between the first and second non- conductive ink layers. The first electrode may be sandwiched between the first and second non-conductive ink layers. The second non-conductive ink layer may form a dielectric layer of the surface EMG apparatus such as if the surface EMG apparatus is a capacitive surface EMG apparatus. The second non-conductive ink layer may comprise an opening to expose the first electrode such as if the surface EMG apparatus is a resistive surface EMG apparatus.

The second non-conductive ink layer may comprise an opening to expose a contact point of the first electrically conductive pathway so as to enable one or more electronics modules to form a conductive connection with the first electrically conductive pathway and therefore form a conductive connection with the first electrode.

The second non-conductive ink layer may be printed onto a substrate. The substrate may be removable from the second non-conductive ink layer following an application of heat or pressure.

The surface EMG apparatus may further comprise an adhesive layer. The adhesive layer may be provided to enable the surface EMG apparatus to be adhered to a surface. The adhesive layer may be provided over the first non-conductive ink layer.

The surface EMG apparatus may comprise a second electrode.

The surface EMG apparatus may further comprise an electrically conductive layer comprising a first area forming the second electrode. A first non-conductive ink layer may cover the electrically conductive layer. The first and second electrodes may both be formed of the same electrically conductive layer and first non-conductive ink layer or may be formed from separate layers.

The first and second electrodes may be arranged together to form a bipolar electrode pair. In a bipolar electrode pair, the first and second electrodes are typically provided at a fixed spacing from one another. The first and second electrodes may have the same surface area.

The first electrode may be spaced apart from the second electrode. The first electrode and the second electrode may form a nested electrode arrangement such that the second electrode is arranged within an opening provided by the first electrode. The first electrode and the second electrode may form a concentric arrangement.

The electrically conductive layer may further comprise a second area forming a second electrically conductive pathway extending from the second electrode. The second electrically conductive pathway may be provided (e.g. sandwiched) between the first and second nonconductive ink layers. The second electrode may be provided between the first and second nonconductive ink layers. The second non-conductive ink layer may form a dielectric layer of the surface EMG apparatus such as if the surface EMG apparatus is a capacitive surface EMG apparatus. The second non-conductive ink layer may comprise an opening to expose the second electrode such as if the surface EMG apparatus is a resistive surface EMG apparatus. The second non-conductive ink layer may comprise an opening to expose a third area of the electrically conductive layer. The third area may form an electrical contact point for the second electrically conductive pathway.

The first electrode and/or the second electrode may have a generally circular or bar shape.

According to a second aspect of the present disclosure, there is provided a wearable item comprising the surface EMG apparatus of the first aspect of the disclosure.

According to a third aspect of the present disclosure, there is provided a textile comprising the surface EMG apparatus of the first aspect of the disclosure.

The textile may be a fabric. The textile may be constructed from a woven or a non-woven material. The textile may be constructed from natural fibres, synthetic fibres, or a natural fibre blended with one or more other materials which can be natural or synthetic. The yarn may be cotton. The cotton may be blended with polyester and/or viscose and/or polyamide according to the particular application. Silk may also be used as the natural fibre. Cellulose, wool, hemp and jute are also natural fibres that may be used in the textile panel. Polyester, polycotton, nylon and viscose are synthetic fibres that may be used in the textile panel. The textile panel may comprise a mesh material or a webbing material.

According to a fourth aspect of the present disclosure, there is provided a garment comprising the textile of the third aspect of the disclosure.

The garment may refer to any item of clothing or apparel. The garment may be a top. The top may be a shirt, t-shirt, blouse, sweater, jacket/coat, or vest. The garment may be a dress, brassiere, shorts, pants, arm or leg sleeve, vest, jacket/coat, glove, armband, underwear, headband, hat/cap, collar, wristband, stocking, sock, or shoe, athletic clothing, swimwear, wetsuit or drysuit. The garment may be constructed from a woven or a non-woven material. The garment may be constructed from natural fibres, synthetic fibres, or a natural fibre blended with one or more other materials which can be natural or synthetic. The yam may be cotton. The cotton may be blended with polyester and/or viscose and/or polyamide according to the particular application. Silk may also be used as the natural fibre. Cellulose, wool, hemp and jute are also natural fibres that may be used in the garment. Polyester, polycotton, nylon and viscose are synthetic fibres that may be used in the garment.

According to a fifth aspect of the disclosure, there is provided a method of manufacturing a surface EMG apparatus. The method comprises printing an electrically conductive ink onto a surface to produce an electrically conductive layer. The electrically conductive layer comprises a first area forming a first electrode of the surface EMG apparatus, The method comprises printing a non-conductive ink over the electrically conductive layer to form a first insulating layer covering the electrically conductive layer. The surface EMG apparatus may be the surface EMG apparatus of the first aspect of the disclosure.

The method may further comprise printing an adhesive layer over the first insulating layer to produce an adhesive layer.

The surface may be a substrate. The surface may be a second insulating layer.

The method may further comprise printing a non-conductive ink onto a substrate to produce the second insulating layer, wherein the electrically conductive ink is printed over the second insulating layer.

The second insulating layer may comprise openings to expose the first electrode.

The method may further comprise curing each layer following the printing of the respective layer, optionally wherein curing may comprise drying the layer.

According to a sixth aspect of the disclosure, there is provided a method of applying a surface electromyography, EMG, apparatus to a surface. The method comprises obtaining a surface EMG apparatus comprising a first electrode. The first electrode comprising: an electrically conductive layer comprising a first area forming the electrode; and a first insulating layer covering the electrically conductive layer. The method comprises positioning the surface EMG apparatus onto a surface. The method may comprise applying at least one of heat or pressure to the surface EMG apparatus such as the surface EMG apparatus adheres to the surface. The surface EMG apparatus may be the surface EMG apparatus of the first aspect of the disclosure.

The method may comprise removing a substrate of the surface EMG apparatus.

Brief Description of the Drawings

Examples of the present disclosure will now be described with reference to the accompanying drawings, in which: Figure 1 shows a simplified schematic view of an example surface EMG apparatus

according to aspects of the present disclosure;

Figure 2 shows a cross-sectional view of an example transfer forming a first electrode and first electrically conductive pathway according to aspects of the present disclosure; Figure 3 shows a simplified schematic view of an example surface EMG apparatus provided on a textile according to aspects of the present disclosure; Figure 4 shows an example garment comprising the textile of Figure 3; Figure 5 shows another example garment comprising the textile of Figure 3; Figure 6 shows a flow diagram for an example method of manufacturing a surface EMG apparatus according to aspects of the present disclosure; and Figure 7 shows a flow diagram for an example method of applying a surface EMG apparatus to a surface according to aspects of the present disclosure.

Detailed Description

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the disclosure. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the disclosure is provided for illustration purpose only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents.

It is to be understood that the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

The following examples describe a surface EMG apparatus comprising a bipolar electrode pair.

It will be appreciated that the present disclosure is not limited to bipolar EMG electrode pair and monopolar EMG electrodes and otherforms of surface EMG electrodes are also within the scope of the present disclosure.

Referring to Figure 1, there is shown an example surface EMG apparatus 1 according to aspects of the present disclosure. The surface EMG apparatus 1 is provided in the form of a transfer.

The surface EMG apparatus 1 comprises a bipolar electrode pair 100 comprising a first electrode 101 and a second electrode 103. An electrically conductive layer 105 is provided. The electrically conductive layer 105 comprises a first area that forms the first electrode 101. A first nonconductive ink layer 107 covers the electrically conductive layer 105. An electrically conductive layer 109 is provided. The electrically conductive layer 109 comprises a first area that forms the second electrode 103. A first non-conductive ink layer 111 covers the electrically conductive layer 105. A first electrically conductive pathway 113 extends from the first electrode 101. The first electrically conductive pathway 113 connects the first electrode 101 to an electronics module 200. The second electrically conductive pathway 115 extends from the second electrode 103.

The second electrically conductive pathway connects the second electrode 103 to the electronics module 200. In this way, the electronics module 200 is able to be conductively connected to the surface EMG apparatus 1.

The electronics module 200 may be operable to receive signals from the bipolar electrode pair 100. The electronics module 200 may be any known electronics module in the art capable of measuring EMG signals from electrodes. The electronics module 200 may comprise a controller with instructions stored in memory, wherein implementation of the instructions causes the controller to receive signals from the bipolar electrode pair 100, amplify and digitize data from the signals. The electronics module 200 may further comprise or may be communicatively coupled to a communicator. The communicator may be operable to transmit signals or the digitized data to a remote computing device. The electronics module 200 may further comprise a power source.

Referring to Figure 2, there is shown a cross sectional view of an example first electrode 101 and first electrically conductive pathway 113 according to aspects of the present disclosure. The first electrode 101 and first electrically conductive pathway 113 are provided as a transfer. The transfer comprises an electrically conductive layer 105 provided between a first non-conductive ink layer 107 and a second non-conductive ink layer 117. The second non-conductive ink layer 117 has a first opening 119 such that a first area of the electrically conductive layer 105 is exposed to form an electrical contact point of the first electrode 101. A second area of the electrically conductive layer is sandwiched between the first and second non-conductive ink layers 107, 117 to form the first electrically conductive pathway 113. The non-conductive ink layers 107, 117 encapsulates the electrically conductive pathway 113. This ensures that the electrically conductive pathway 113 is kept in a waterproof environment such that, when applied to a suitable surface, the surface in combination with the transfer can be washed without damage to electrically conductive pathway 113. The second non-conductive ink layer 117 has a second opening 121 such that a third area of the electrically conductive layer 105 is exposed to form an electrical contact point of the electrically conductive pathway 113. This allows for the electronics module 200 to form an electrical connection with the electrically conductive pathway 113.

It will be appreciated that the first opening 119 may not be required if, for example, the electrode 101 is used in capacitive based surface EMG apparatus. In such examples, the second non-conductive ink layer 117 may cover the electrode 101 and act as a dielectric layer. Alternatively, a separate dielectric layer may be provided.

It will be appreciated that the second opening 121 may not be required if, for example, the electronics module 200 connects to the electrically conductive pathway 113 via a stud or prong that is configured to penetrate through one or both of the non-conductive ink layers 107, 117.

Moreover, the second opening 121 may be provided in the first non-conductive ink layer 107 in some examples. It will be further appreciated that depending on factors such as the conductive ink used for the electrically conductive ink layer 105 and the type of printing used, the electrically conductive layer 105 may extend into the openings 119, 121.

The second non-conductive ink layer 117 is provided on a substrate 123 which in this example is transfer paper 123. The first non-conductive ink layer 107 is covered with an adhesive layer 125. The adhesive layer 125 may be used to attach the transfer to a surface. The substrate 123 may then be removed to expose the first electrode 101. The layers of the transfer are applied onto the substrate 123 in sequence.

It will be appreciated that the second electrode 103 and second electrically conductive pathway 115 may have the same or similar structure to that shown in Figure 2. The second electrode 103 and the second electrically conductive pathway 115 may be formed from the same electrically conductive ink layer 105 as the first electrode 101 and first electrically conductive pathway 113. The first and second non-conductive ink layers 107, 117 may comprise a suitable printing ink such as a water-based printing ink; an ultraviolet cured printing ink; a solvent based ink; or a latex printing ink. Any other printing ink may be used. The electrically conductive layer 105 comprises any suitable conductive ink of any specified resistance and is configured to provide a conductive path on application of an electric current orvoltage. The conductive ink may comprise silver ink. The conductive ink may comprise graphene ink. The conductive ink may comprise a combination of silver and graphene ink.

The adhesive layer 125 may comprise a water based, solved based, printable, powder or any other suitable adhesive which can adhere the transfer to a surface. The substrate 123 may be any form of substrate onto which the layers mentioned above may be printed onto. The substrate 123 may be, for example, a paper film, polyester fil, coated paper or thermoplastic polyurethane film.

The total thickness of the layers forming the transfer may be between zero point five millimetres and five millimetres.

Referring to Figure 3, there is shown an example surface EMG apparatus 1 according to aspects of the present disclosure applied to a surface 300. The surface 300 in this example is a textile 300. The electrical contact points of the first electrode 101 and the second electrode 103 are exposed through openings in the second insulating layers 117, 127. The electrically conductive pathways extend from the first and second electrodes 101, 103 are covered by the second insulating layers 117, 127 except at the openings 121, 129.

Referring to Figure 4, there is shown a front view of an example garment 400 according to aspects of the present disclosure. The garment 400 comprises a T-shirt 401 with the textile 300 of Figure 3 incorporated into a side of the T-shirt 401. The textile 300 extends round to the back of the T-shirt 401.

Referring to Figure 5, there is shown a front view of an example garment 400 according to aspects of the present disclosure. The garment 400 comprises an outer textile layer 401 in the form of a T-shirt 401.The garment 400 comprises an inner textile layer 403 disposed within the outer textile layer 401. The inner textile layer 403 comprises the textile 300 of Figure 3. The textile 300 is incorporated into the side of the inner textile layer 403 and extends round the back of the inner textile layer 403. The inner textile layer 403 is in the form of a crop that covers the front and back upper chest regions of the wearer. The crop provides a relatively tight fit so as to help hold the sensing units in close proximity/skin contact with the skin surface of the wearer.

The outer textile layer 401 may be loose fitting for comfort and appearance. The inner textile layer 403 is attached to the outertextile layer401 at the shoulder regions 405 using a twin needle top stitch. The inner textile layer 403 defines armholes through which the arms may pass through when worn. The inner textile layer 403 formed of a raw edge mesh material. The textile 300 is made of a woven textile material. The woven textile material in this example is cut on the grain.

Referring to Figure 6, there is shown a process flow diagram for an example method according to aspects of the present disclosure for manufacturing a surface EMG apparatus. Step S101 of the method comprises printing an electrically conductive ink onto a surface to produce an electrically conductive layer, wherein the electrically conductive layer comprises a first area forming the first electrode and the second electrode of a bipolar electrode pair. Step S102 of the method comprises printing a non-conductive ink over the electrically conductive layer to form a first insulating layer covering the electrically conductive layer.

The method referred to in Figure 6 may be performed using a screen-printing process. The substrate may be laid onto a printing surface. Ink may be applied to the substrate via ink being applied through a screen. The screen includes a stencil which indicates the design to be printed. Once a layer has been printed, the layer is cured. The present disclosure is, however, not limited to screen printing. The method may be conducted by any form of printing such as ink jet printing, flexographic printing, digital printing or gravure printing.

Referring to Figure 7, there is shown an example method of applying a surface EMG apparatus to a surface. Step S201 of the method comprises obtaining a surface EMG apparatus comprising a bipolar electrode pair comprising a first electrode and a second electrode, each of the electrodes comprising: an electrically conductive layer comprising a first area forming the electrode; and a first insulating layer covering the electrically conductive layer. Step S202 of the method comprises positioning the surface EMG apparatus onto a surface. Step S203 of the method comprises applying at least one of heat or pressure to the surface EMG apparatus such as the surface EMG apparatus adheres to the surface. A heat press may be used to adhere the surface EMG apparatus to a surface.

At least some of the example embodiments described herein may be constructed, partially or wholly, using dedicated special-purpose hardware. Terms such as 'component', 'module' or 'unit' used herein may include, but are not limited to, a hardware device, such as circuitry in the form of discrete or integrated components, a Field Programmable Gate Array (FPGA) or Application Specific Integrated Circuit (ASIC), which performs certain tasks or provides the associated functionality. In some embodiments, the described elements may be configured to reside on a tangible, persistent, addressable storage medium and may be configured to execute on one or more processors. These functional elements may in some embodiments include, by way of example, components, such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. Although the example embodiments have been described with reference to the components, modules and units discussed herein, such functional elements may be combined into fewer elements or separated into additional elements. Various combinations of optional features have been described herein, and it will be appreciated that described features may be combined in any suitable combination. In particular, the features of any one example embodiment may be combined with features of any other embodiment, as appropriate, except where such combinations are mutually exclusive.

Throughout this specification, the term "comprising" or "comprises" means including the component(s) specified but not to the exclusion of the presence of others.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.

Claims

11 CLAIMS 1. A surface electromyography, EMG, apparatus in the form of a transfer, comprising: an electrically conductive layer comprising a first area forming a first electrode; and a first non-conductive ink layer covering the electrically conductive layer.

2. A surface EMG apparatus as claimed in claim 1, wherein the electrically conductive layer further comprises a second area forming a first electrically conductive pathway extending from the first electrode.

3. A surface EMG apparatus as claimed in claim 2, further comprising a second nonconductive ink layer, wherein the first electrically conductive pathway is provided between the first and second non-conductive ink layers.

4. A surface EMG apparatus as claimed in claim 3, wherein the first electrode is provided between the first and second non-conductive ink layers.

5. A surface EMG apparatus as claimed in claim 3 or4, wherein the second non-conductive ink layer comprises an opening to expose the first electrode.

6. A surface EMG apparatus as claimed in any of claims 3 to 5, wherein the second nonconductive ink layer comprises an opening to expose an electrical contact point of the electrically conductive pathway.

7. A surface EMG apparatus as claimed in any of claims 3 to 6, wherein the second non-conductive ink layer is printed onto a substrate.

8. A surface EMG apparatus as claimed in claim 7, wherein the substrate is removable from the second insulating layer following an application of heat or pressure.

9. A surface EMG apparatus as claimed in any preceding claim, further comprising an adhesive layer.

10. A surface EMG apparatus as claimed in any preceding claim, further comprising an electrically conductive layer comprising a first area forming a second electrode; and a first non-conductive ink layer covering the electrically conductive layer, wherein the first electrode and the second electrode form a bipolar electrode pair.

11. A surface EMG apparatus as claimed in claim 10, wherein the first electrode is spaced apart from the second electrode.

12. A surface EMG apparatus as claimed in claim 10, wherein the first electrode and the second electrode form a nested electrode arrangement such that the second electrode is arranged within an opening provided by the first electrode.

13. A wearable item comprising the surface EMG apparatus as claimed in any preceding claim. 10

14. A textile comprising the surface EMG apparatus as claimed in any of claims 1 to 12.

15. A garment comprising the textile of claim 14.

16. A method of manufacturing a surface EMG apparatus in the form of a transfer comprising: printing an electrically conductive ink onto a surface to produce an electrically conductive layer, wherein the electrically conductive layer comprises a first area forming a first electrode; and printing a non-conductive ink over the electrically conductive layer to form a first insulating layer covering the electrically conductive layer.

17. A method as claimed in claim 16, further comprising printing an adhesive layer over the first insulating layer to produce an adhesive layer.

18. A method as claimed in claim 16 or 17, wherein the surface is a substrate.

19. A method as claimed in claim 16 or 17, wherein the surface is a second non-conductive ink layer.

20. A method as claimed in claim 19, further comprising: printing a non-conductive ink onto a substrate to produce the second insulating layer, wherein the electrically conductive ink is printed over the second insulating layer.

21. A method as claimed in claim 19 or 20, wherein the second insulating layer comprises an opening to expose the first electrode.

22. A method as claimed in any of claims 16 to 21, further comprising curing each layer following the printing of the respective layer, optionally wherein curing comprises drying the layer.

23. A method of applying a surface electromyography, EMG, apparatus in the form of a transfer to a surface comprising: obtaining a surface EMG apparatus comprising an electrically conductive layer comprising a first area forming a first electrode; and a first insulating layer covering the electrically conductive layer; positioning the surface EMG apparatus onto a surface; applying at least one of heat or pressure to the surface EMG apparatus such as the surface EMG apparatus adheres to the surface.

24. A method as claimed in claim 23, further comprising removing a substrate of the surface EMG apparatus.