Patent Description:
Many disease patients and surgery patients have requirements of exercise rehabilitation therapy. The exercise rehabilitation therapy is preferably made within the golden rehabilitation period to achieve good performance. For example, functional electrical stimulation (FES) is an active rehabilitation type, which introduces current under skin to occur muscle contraction thereby increasing functional activities of extremities.

The traditional electronic muscle stimulation (EMS) electrodes are disposable electrodes which cannot be multiple used and pollute the environment. Recently, textile electrodes which can be multiple used are well developed. The conductive fibers in the textile electrodes are utilized to contact the wearer's skin to generate muscle stimulation. However, due to the uneven conductive paths of the conductive fibers in the textile electrodes, the EMS points of the textile electrodes have uneven resistances, and the voltage potentials of the EMS points of the textile electrodes are different. Therefore, the wearer may feel spike and uncomfortable while using the textile electrodes.

Document Document <CIT> discloses the most relevant prior art.

SUMMARY The invention is defined in claim <NUM>.

An aspect of the disclosure provides an electrode structure for electronic muscle stimulation (EMS). The electrode structure includes a conductive fabric layer, a water retention fabric layer, and an insulation cover. The conductive fabric layer has a first surface and a second surface opposite to each other. The water retention fabric layer is connected to the first surface of the conductive fabric layer, in which the EMS points of the electrode structure are consisted of the water retention fabric layer. The insulation cover is disposed on the first surface of the conductive fabric layer and surrounding the edges of the water retention fabric layer.

According to some embodiments of the disclosure, the electrode structure has a surface resistance ranging from <NUM> kΩ to <NUM> kΩ, after the electrode structure absorbs moisture.

According to some embodiments of the disclosure, the electrode structure has an EMS current ranging from <NUM> mA to <NUM> mA.

According to some embodiments of the disclosure, the electrode structure further includes a dielectric isolation layer disposed on the second surface of the conductive fabric layer.

According to some embodiments of the disclosure, the electrode structure further includes a conductive contact penetrating the dielectric isolation layer and connecting to the conductive fabric layer such that a voltage is applied to the conductive fabric layer via the conductive contact.

According to some embodiments of the disclosure, the water retention fabric layer and the conductive fabric layer are interconnected by a plurality of water retention yarn loops of the water retention fabric layer and a plurality of conductive yarn loops of the conductive fabric layer, and the conductive yarn loops are completely hidden under the water retention yarn loops.

According to some embodiments of the disclosure, the conductive fabric layer is a fabric comprising conductive yarns or metal wires, or a non-woven fabric coated with a conductive layer.

According to some embodiments of the disclosure, the water retention fabric layer comprises cotton fibers, modified nylon fibers, alginate fibers, or combinations thereof.

According to some embodiments of the disclosure, the dielectric protection layer comprises silicon or elastic plastic.

According to some embodiments of the disclosure, a moisture transferring ability of the water retention fabric layer is greater than level <NUM>, following FTTS-FA-<NUM> test method.

The present disclosure provides an electrode structure to gently and indirectly transfer an external voltage to the wearer's skin. The EMS points of the electrode structure are consisted of the water retention fabric layer. The external voltage enters the conductive fabric layer then is transferred to the wet water retention fabric layer, and then the external voltage is transferred to the wearer's skin via the wet water retention fabric layer. Additionally, the wet water retention fabric layer as a whole has the same potential, thus the problem of local thermal points or local spike points can be prevented in the electrode structure of the present disclosure.

In the drawings,.

Reference will now be made in detail to the present embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.

Reference is made to <FIG> and <FIG>. <FIG> is a schematic view of an electrode structure for electronic muscle stimulation (EMS) according to some embodiments of the disclosure, and <FIG> is a cross-sectional view of the electrode structure for EMS of <FIG>. The electrode structure <NUM> includes a conductive fabric layer <NUM>, a water retention fabric layer <NUM>, and a dielectric protection layer <NUM>. The conductive fabric layer <NUM> has a first surface <NUM> and a second surface <NUM> opposite to each other, in which the first surface <NUM> of the conductive fabric layer <NUM> facing the wearer's skin. The water retention fabric layer <NUM> is connected to the first surface <NUM> of the conductive fabric layer <NUM>. The EMS points P of the electrode structure <NUM> are consisted of the water retention fabric layer <NUM>. The dielectric protection layer <NUM> is disposed on the first surface <NUM> of the conductive fabric layer <NUM> and surrounding a peripheral of the water retention fabric layer <NUM>. In some embodiments, the material of the dielectric protection layer <NUM> includes silicon or elastic plastic such as thermoplastic polyurethane (TPU).

In some embodiments, the size of the water retention fabric layer <NUM> is smaller than the size of the conductive fabric layer <NUM>. The shape of the dielectric protection layer <NUM> can be a rectangle having an opening <NUM>. The dielectric protection layer <NUM> covers the first surface <NUM> of the conductive fabric layer <NUM>, and the water retention fabric layer <NUM> is exposed from the opening <NUM> of the dielectric protection layer <NUM>. As a result, when the electrode structure <NUM> is used during the EMS test, only the water retention fabric layer <NUM> and the dielectric protection layer <NUM> contact the wearer's skin, and the conductive fabric layer <NUM> does not directly contact the wearer's skin. In some embodiments, the thickness of the water retention fabric layer <NUM> is thicker than the thickness of the dielectric protection layer <NUM>. Therefore, when the electrode structure <NUM> is worn and in contact with the wearer's skin, the water retention fabric layer <NUM> is protruded toward the wearer's skin such that the water retention fabric layer <NUM> can touch the wearer's skin firmly.

The material of the water retention fabric layer <NUM> has a property that can obviously change the surface resistance of the electrode structure <NUM> after the water retention fabric layer <NUM> absorbs moisture, in which the surface resistance of the electrode structure <NUM> is measured at the portion of the water retention fabric layer <NUM> exposed by the opening <NUM> of the dielectric protection layer <NUM>. It is noted that the portion of the water retention fabric layer <NUM> exposed by the opening <NUM> of the dielectric protection layer <NUM> is also served as the portion providing electric stimulation to the wearer's skin.

In some embodiments, the water retention fabric layer <NUM> has high moisture absorbing and transferring ability. The water retention fabric layer <NUM> is able to quickly absorb moisture from environment or from skin, and further evenly spreads the moisture in the fibers of the water retention fabric layer <NUM>. A moisture transferring ability of the water retention fabric layer <NUM> is greater than level <NUM>, following FTTS-FA-<NUM> test method. After the water retention fabric layer <NUM> absorbs sufficient amount of moisture, the moisture in the water retention fabric layer <NUM> is ionized by potential difference when an external voltage is applied to the water retention fabric layer <NUM>. The ionization of the moisture in the water retention fabric layer <NUM> leads to electron flow, and the ionized moisture becomes conductive. As a result, the surface resistance of the water retention fabric layer <NUM> can be greatly reduced.

Namely, before the water retention fabric layer <NUM> absorbs moisture, e.g. the water retention fabric layer <NUM> is dry, the electrode structure <NUM> has a huge surface resistance such as greater than <NUM> MΩ, and the water retention fabric layer <NUM> can be regarded as an insulator. After the water retention fabric layer <NUM> absorbs sufficient amount of moisture and an external voltage is applied to the water retention fabric layer <NUM>, the potential difference leads to ionization of the moisture, thus the surface resistance of the water retention fabric layer <NUM> is obviously reduced, and the water retention fabric layer <NUM> can be regarded as a conductor. The external voltage may enter the water retention fabric layer <NUM> via the conductive fabric layer <NUM> and then enter wearer's skin via the water retention fabric layer <NUM>. At this time, the surface resistance of the electrode structure <NUM> is reduced to a range from <NUM> kΩ to <NUM> kΩ.

The surface resistance of the water retention fabric layer <NUM> changes obviously after the water retention fabric layer <NUM> absorbs moisture. In some embodiments, the water retention fabric layer <NUM> can be cotton fibers, modified nylon fibers, alginate fibers, or combinations thereof. For example, the yarn utilized in the water retention fabric layer <NUM> can be core-spun yarn, in which the shell of the core-spun yarn can be hydrophilic fiber such as modified nylon fibers or alginate fibers, and the core of the core-spun yarn can be cotton fibers, to absorb moisture in the core-spun yarn to achieve the water retention purpose.

The material of the water retention fabric layer <NUM> is not selected from a conductor. Therefore, the problem of local thermal points or local spike points raised by using conductive fabric as EMS electrode contact plane in the traditional EMS device can be prevented.

Additionally, the water retention fabric layer <NUM> is directly connected to the conductive fabric layer <NUM>. The external voltage can be gently and indirectly transferred to the wearer's skin through the electrode structure <NUM>. More particularly, the external voltage first enters the conductive fabric layer <NUM>, then enters the wet water retention fabric layer <NUM>, then enters the wearer's skin for EMS. The wet water retention fabric layer <NUM> as a whole has the same potential, thus the problem of local thermal points or local spike points can be prevented in the electrode structure <NUM> of the present disclosure.

In some embodiments, the EMS current of the electrode structure <NUM> is in a range from <NUM> mA to <NUM> mA, which is strong enough to induce the corresponding wearer's muscle reaction such as grasp or palm lifting, etc. With the increasing of the EMS current, the angle of wearer's muscle reaction such as the lifting angle of wearer's palm is increased accordingly.

Reference is made to table <NUM>, which shows the fabric dry rates and moisture transferring abilities of different embodiments of the water retention fabric layer <NUM> of the electrode structure <NUM> of the present disclosure. The water retention fabric layer <NUM> may be cotton fibers, alginate fibers and cotton fibers (e.g. the core-spun yarns including alginate fibers and cotton fibers), or modified nylon fibers (e.g. Aquatimo). Embodiments of water retention fabric layer <NUM> can be formed of different fibers and different weaving forms, and the test results following FTTS-FA-<NUM>, including fabric dry rates and moisture transferring abilities, of the embodiments of water retention fabric layer <NUM> are shown in table <NUM>. According to the measured fabric dry rates, these water retention fabric layer <NUM> have moisture-containing ratios greater than <NUM>%, which represent that the water retention fabric layers <NUM> have good moisture-containing abilities. According to the measured moisture transferring abilities, the water retention fabric layers <NUM> made of alginate fibers and cotton fibers or modified nylon fibers have good moisture transferring abilities and are able to provide uniform conductivities.

Generally, a single cycle of EMS is about <NUM> minutes to <NUM> minutes. According to the test result, the moisture-containing abilities of the water retention fabric layers <NUM> can to keep sufficient amount of moisture for complete the EMS cycle.

Reference is further made to <FIG> and <FIG>. <FIG> is a schematic view of an electrode structure for EMS according to some embodiments of the disclosure, and <FIG> is a cross-sectional view of the electrode structure for EMS of <FIG>. The electrode structure <NUM> includes a conductive fabric layer <NUM>, a water retention fabric layer <NUM>, a dielectric protection layer <NUM>, a dielectric isolation layer <NUM>, and a conductive contact <NUM>. The conductive fabric layer <NUM> has a first surface <NUM> and a second surface <NUM> opposite to each other, and the water retention fabric layer <NUM> is connected to the first surface <NUM> of the conductive fabric layer <NUM>. The EMS points P of the electrode structure <NUM> are consisted of the water retention fabric layer <NUM>. The dielectric protection layer <NUM> is disposed on the first surface <NUM> of the conductive fabric layer <NUM> and surrounding a peripheral of the water retention fabric layer <NUM>. The dielectric isolation layer <NUM> is disposed on the second surface <NUM> of the conductive fabric layer <NUM>. The conductive contact <NUM> penetrates the dielectric isolation layer <NUM> and is connected to the conductive fabric layer <NUM>. Thus an external voltage can be provides to the conductive fabric layer <NUM> via the conductive contact <NUM>.

The external voltage is gently and indirectly transferred to the wearer's skin through plural layers within the electrode structure <NUM>. The external voltage first enters the conductive fabric layer <NUM> via the conductive contact <NUM>. Then the external voltage enters the wet water retention fabric layer <NUM> through the conductive fabric layer <NUM> and then enters wearer's skin via the water retention fabric layer <NUM> for EMS. In order to improve the moisture-containing ability of the water retention fabric layer <NUM>, the dielectric isolation layer <NUM> is disposed on the second surface <NUM> of the conductive fabric layer <NUM> of the electrode structure <NUM>, to keep the moisture in the wet water retention fabric layer <NUM>.

In some embodiments, the material of the dielectric protection layer <NUM> includes silicon or elastic plastic such as TPU. The materials of the dielectric protection layer <NUM> and the dielectric protection layer <NUM> can be the same or different. In some embodiments, the dielectric protection layer <NUM> is detachably assembled to the conductive fabric layer <NUM> such as jacketing or wrapping on the conductive fabric layer <NUM>. Thus the electrode structure <NUM> can be free of damaged by the moisture environment while storing the electrode structure <NUM> not in EMS use.

In some embodiments, the conductive contact <NUM> is a metal plug or a metal pillar. The corresponding host can be coupled to or clamped to the metal plug or the metal pillar conductive contact <NUM> through a fastener or a clamp. The external voltage provided by the host is transferred to the conductive contact <NUM>, and is transferred to the conductive fabric layer <NUM> via the conductive contact <NUM>. Then the external voltage is transferred to the wet water retention fabric layer <NUM> through the conductive fabric layer <NUM>. The wet water retention fabric layer <NUM> is in contact with the wearer's skin such that the external voltage is transferred to the wearer's skin for EMS.

Reference is made to <FIG>, which is an arrangement of the conductive fabric layer and the water retention fabric layer of the electrode structure according to some embodiments of the disclosure. The conductive fabric layer <NUM> and the water retention fabric layer <NUM> can be integrately formed by a weaving process. For example, the electrode structure <NUM> has first regions <NUM> and a second region <NUM>, in which the second region <NUM> is between the first regions <NUM>. The first regions <NUM> are formed by conductive fibers, and the second region <NUM> is formed by conductive fibers and water retention fibers. The rectangle dielectric isolation layer with an opening (not shown) is further sealed thereon. The dielectric isolation layer covers the first regions <NUM> and peripheral of the second region <NUM> and allows a portion of the second region <NUM> exposing from the opening of the dielectric isolation layer.

It is noted that on the inner side of the electrode structure <NUM>, only the water retention fibers are revealed at the second region <NUM>, and the conductive fibers are hidden under the water retention fibers. For example, the conductive fabric layer <NUM> and the water retention fabric layer <NUM> can be formed by flat knitting, in which the water retention yarn loops of the water retention fabric layer <NUM> and the conductive yarn loops of the conductive fabric layer <NUM> are interconnected at the second region <NUM>, and the conductive yarn loops are completely hidden under the water retention yarn loops of the water retention fabric layer <NUM>.

Reference is made to <FIG>, which are the knitting rules of forming the first regions and second region of <FIG>. The first regions <NUM> in <FIG> are formed by the knitting rule disposed in <FIG>. The sequence of the needle plate and the operation of the needles are shown in <FIG>, in which "^" represents forming a yarn loop, and F1 is a conductive yarn. The second region <NUM> in <FIG> is formed by the knitting rule disposed in <FIG>. The sequence of the needle plate and the operation of the needles are shown in <FIG>, in which "∧" and "v" both represent forming a yarn loop, F1 is a conductive yarn, and F2 is a water retention yarn.

In some embodiments, the water retention fibers can be cotton fibers, modified nylon fibers, alginate fibers, or combinations thereof. The water retention fibers can be single core yarns or core-spun yarns. In some embodiments, the conductive fibers can be fibers including metal wires or fibers coated with a metal layer. The metal utilized in the conductive fibers can be Au, Ag, Cu, Ni, Cr, or alloys thereof.

Reference is made to <FIG>, which is an arrangement of the conductive fabric layer and the water retention fabric layer of the electrode structure according to some other embodiments of the disclosure. The conductive fabric layer <NUM> and the water retention fabric layer <NUM> of the electrode structure <NUM> can be formed separately, and then the conductive fabric layer <NUM> and the water retention fabric layer <NUM> are combined. For example, the conductive fabric layer <NUM> cane be a fabric comprising conductive yarns or metal wires, or the conductive fabric layer <NUM> can be a non-woven fabric coated with a conductive layer. The water retention fabric layer <NUM> can be a fabric or a non-woven fabric made of cotton fibers, modified nylon fibers, alginate fibers, or combinations thereof. The water retention fabric layer <NUM> can be combined with the conductive fabric layer <NUM> by a needling punching process.

The rectangle dielectric isolation layer with an opening (not shown) is further sealed thereon. The dielectric isolation layer covers an edge of the water retention fabric layer <NUM> and allows a portion of the water retention fabric layer <NUM> exposing from the opening of the dielectric isolation layer. Because the edge of the water retention fabric layer <NUM> is sandwiched between the dielectric isolation layer and the conductive fabric layer <NUM>, the binding of the conductive fabric layer <NUM> and the water retention fabric layer <NUM> is secured to prevent unwanted delamination.

Claim 1:
An electrode structure for electronic muscle stimulation (EMS) (<NUM>, <NUM>, <NUM>, <NUM>), characterized by comprising:
a conductive fabric layer (<NUM>, <NUM>, <NUM>, <NUM>) having a first surface (<NUM>, <NUM>) and a second surface (<NUM>, <NUM>) opposite to each other;
a water retention fabric layer (<NUM>, <NUM>, <NUM>, <NUM>) connected to the first surface (<NUM>, <NUM>) of the conductive fabric layer (<NUM>, <NUM>, <NUM>, <NUM>), wherein a plurality of EMS points (P) of the electrode structure (<NUM>, <NUM>, <NUM>, <NUM>) are consisted of the water retention fabric layer (<NUM>, <NUM>, <NUM>, <NUM>); and
a dielectric protection layer (<NUM>, <NUM>) disposed on the first surface (<NUM>) of the conductive fabric layer (<NUM>, <NUM>, <NUM>, <NUM>) and surrounding a peripheral of the water retention fabric layer (<NUM>, <NUM>, <NUM>, <NUM>).