Sensory for measuring of signals on the surface of the skin and method for producing of the sensory

Abstract

The present invention relates to sensory for measuring signals on the surface of the skin and for producing sensory. In the sensory in accordance with the invention, the electrode surfaces required for measuring of a signal and/or conductors required for transmitting of a signal have been fastened to the textile material of an outfit or accessory used on the body. In the method in accordance with the invention, the electrode surfaces required for the sensory and/or conductors are added to the textile material of an outfit or accessory used on the body.

Description

The application is a continuation of International Patent Application No. PCT/FI2004/00594.

The present invention relates to sensory for recognizing and measuring signals on the surface of the skin. In addition, the present invention relates to a method for producing sensory.

BACKGROUND OF THE INVENTION

It is commonly recognized that by means of various kinds of sensors several signals in electrical form may be measured on the surface of the skin, such as:

• • electrical curve of heartbeat that is the ECG signal
  • electrical activity of muscles that is the EMG signal
  • electrical curve of brain function that is the EEG signal
  • conductivity of the surface of the skin
  • respiration rate
  • percentage of fat
  • intracellular and extracellular fluid balance in the body

In sensories today in use, two or several electrodes are typically used, between which an electrical signal describing the potential difference is measured and which signal is transmitted for further processing in an electronic device. Measuring electrodes mentioned earlier are either separate electrodes to be attached on the skin one by one or electrode groups comprising several electrode surfaces, or various constructions placed on outfits, belts, bands or similar to be worn by a person, in which case several individual electrode surfaces in those are situated on the skin in defined places and in defined order.

Electrodes in clinical measurements are fastened with glue or a suction cup on the skin and the quality of a signal is secured by means of a special gel or similar improving conductivity. Outside clinical environment, for instance, during a physical exercise these kinds of electrodes have proved to be unpractical despite their reliability.

Sensories so-called heart rate monitors meant for monitoring a physical exercise are based on recognizing heartbeat by means of a sensor placed on the chest. The sensor is typically a solid elastic band by shape (a sensor band) or an elastic textile belt (a sensor belt) or an outfit, to which conductive electrode constructions have been integrated. Most conductive electrode surfaces in sensor bands are fastened to a frame part, by means of which the electrodes are then placed against the skin. Typically, the frame part is not able to stick to the skin by itself but it needs a separate fastening part, for instance, an elastic band or belt.

Electrodes in a sensor band are usually made of electro conductive plastics. The band is fastened on the chest by means of an elastic ribbon, the tightness of which is adjustable. As the plastic electrode surface is of solid material, there will by nature appear a wet space maintaining conductivity between the skin and the electrodes. Especially, during long performances and while sweating a lot, the band, however, slips away from its place or it may feel uncomfortable or cause abrasion. In addition, various disturbances are easily connected to measuring of a signal since the band as a solid construction is not elastic enough during motions normally included in the performance.

In a textile sensor band or similar outfit, the electrodes have been made of conductive textile or of conductive fibres, which are integrated to isolating textile in other way. While the textile construction in itself is permeable, on the outside of the textile electrode a separate layer holding moisture must be attached, for instance, by sewing, in which case sufficient conductivity is created between an electrode and the skin. The electrode constructions gathered in this way are attached to a belt or an outfit, for instance, by sewing. The belt or the outfit is put on in which case electrodes in them are placed on the chest to points where they stay in place as well as possible from the measuring point of view also during physical exercise. Especially, in outfit-type solutions, in places where the electrodes are, there will be thicker areas in the outfit fabric where the extra thickness due to the electrode textile and the layers holding moisture and their seams stiffen the fabric hindering the wearability of the outfit and causing disturbance for its part in the measurement. In addition, the most advantageous shape of textile electrode surfaces and moisturizing layers is usually square, as that shape is the most convenient to cut and to sew in manufacturing phase. A square shape is, however, not always the best shape in terms of measuring the actual signal, as, for instance, free and flexible shapes fitting as good as possible to the body anatomy are needed in measuring muscle activities.

Measuring heart rate during swimming or some other activity in water is especially complicated. Water may pass between the sensor band and the skin during swimming or in some other water activity, in which case impurities in the water (among other things salt, chlorine etc.) cause a short circuit between the electrodes of the band or some other means, in which case the measuring signal is disturbed. In addition, the flow resistance of water tends to move the band on the chest downwards the body, in which case the band is inconvenient to wear and causes friction slowening swimming.

Outfits on market with integrated electrodes in them have usually been made by adding conductive fibres or areas made of conductive material already in the manufacturing phase of the fabric or the outfit. Conductive fibres may be sewed among the own fibres of the ready fabric or they may be knitted or weaved straight to the structure of the fabric in the manufacturing phase. In other words, conductive material is either conductive fibre-like material or material is of fibre the surface of which has been made conductive. These fibres are then integrated to an outfit. Conductive material needs a supporting construction to be able to be attached to an outfit. These conductive fibres must also be made to a fibre-like form, as conductive fibre-like raw material does not exist. Electrode areas on outfits are also made by cutting off normal fabric from a ready outfit and fitting fabric made of conductive material or some other material to the area made in this way. Implementation of all outfits mentioned earlier requires special design and/or extra working phases, which increase manufacturing costs and which also partly changes the original usability characteristics of the outfit.

The object of the invention is to provide a sensory for measuring signals on the surface of the skin and a method for producing sensory, with the use of which disadvantages related to present methods are eliminated. Especially, the object of the invention is to provide sensory, which meets the shape and elasticity demands important from the signal-measuring point of view, and while using which the measuring electrodes stay in their place and in reliable contact also during a long-term measuring, heavy perspiration and various movements. In addition, sensory enables reliable and easy-to-use measurements also on users differing from each other by anatomy. Furthermore, the object of the invention is to provide a method, with the use of which sensory is able to be realized simply, advantageously and reliably.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and other features of the invention are explained in the following description, taken in connection with the accompanying drawings, wherein:

FIG. 1 is a view of an untreated fabric;

FIG. 2 is a cross sectional view of one of the fibers shown in FIG. 1;

FIG. 3 is a view of the fabric of FIG. 1 with impervious to moisture material penetrating and coating the fabric;

FIG. 4 is a cross sectional view of one of the fibers shown in FIG. 3;

FIG. 5 is a view showing the fabric and material of FIG. 3 with a conductive coat;

FIG. 6 is a cross sectional view of one of the fibers shown in FIG. 5; and

FIG. 7 is a cross sectional view of an alternate embodiment of one of the fibers shown in FIG. 5.

Sensory according to an exemplary embodiment of the present invention is shown in FIG. 8. As shown, the sensory 20 comprises: a textile material 21, at least one non-conductive material layer 22 fastened by coating on the textile material 21, a conductive electrode surface 23 fastened by coating on the non-conductive material layer 22 and a conductor 24 fastened by coating on the non-conductive material layer 22.

In an advantageous application of the invention, the electrodes required for measuring the heart rate are placed on a swimming suit or similar outfit worn in water. In swimming trunks, the place is on the waist area of trunks. In other swimming suits, electrodes may be placed also such that they are near the chest. It is recognized that the surroundings of electrodes and the outfit fabric on electrodes may be tightened and impregnated with material or a film, impervious to water, which, on one hand prevents the access of water between electrodes and the skin and, on the other hand isolates electrodes from each other. With the method in accordance with the invention, measuring outfits used in water may be produced by adding isolating material around electrodes such that desired tightness and isolating characteristics are achieved. For example, an area, somewhat larger than the desired electrode, may first be moulded of non-conductive silicone to an outfit, on which area the electrode surface itself of conductive silicone is moulded. The size, shape and the tightness of border areas of electrodes may be improved by moulding new suitably designed layers of isolating silicone on the earlier mentioned layers. In this case, a silicone layer impervious to moisture is generated around the electrodes and between an electrode and fabric, which layer prevents the access of moisture from outside to the conductive surface of the electrode placed against the skin. In addition, the transmitting of signals from electrodes to measuring electronics may be realized similarly tightened and isolated. While being a part of an outfit, this kind of construction adapts anatomically right against the body, in which case the additions to the swimwear caused by electrodes do not increase the kinetic friction between the body and water.

In an advantageous additional application some substance or layers added to the surface of the material worn on the body is made of absorptive material, to which gel, improving conductivity, lotion, moisturizing the skin, cream improving elasticity of the skin or some other chemical meant for conditioning the skin is absorbed. By means of absorbed substance the conductivity between the skin and the electrode surface and the permanency of conductivity may be improved, for example, when the measuring situation does not include perspiration more than normally or when the skin type of the person measured is naturally dry, tight or in other ways disadvantageous in terms of measuring.

The invention is not limited to the presented advantageous application but it can vary within the frames of the idea of the invention formed in the claims.

Claims

1. Sensory for measuring signals on the surface of the skin, comprising:

conductive electrode surfaces for measuring signals fastened by a coating on textile material of an outfit configured to be worn on a body directly on the skin, forming a conductive coating, and

the conductive coating covering fibers of the textile itself thoroughly with a layer of desired thickness leaving loop areas between the coated fibers open and being formed to produce a membrane and effect an impervious nature of an electrode construction,

wherein both the coating and an impervious material that form the construction are coated on the textile material,

and the conductive coating and the impervious material are placed together overlapping each other in one plane to form the construction, which is both conductive and essentially impervious to moisture.

2. Sensory in accordance with claim 1, wherein the conductive electrode surfaces have been designed in accordance with anatomy of a body and/or in a functional way from a measuring point of view.

3. Sensory in accordance with claim 1, wherein the conductive electrode surfaces are flexible such that the shape of the surfaces stretches and damages weakening conductivity is not generated in the conductive surfaces.

4. Sensory in accordance with claim 1, wherein the fibers of the textile material comprise a first coating of the impervious material and then a subsequent coating of the conductive electrode surfaces leaving the open loop areas between the coated fibers.

5. Method for producing a sensory for measuring signals on the surface of the skin, comprising:

adding conductive electrode surfaces, for the sensory, by coating textile material of an outfit configured to be worn on a body directly on the skin, to form a conductive coating,

the conductive coating covering fibers of the textile itself thoroughly with a layer of desired thickness leaving loop areas between the coated fibers open and being formed to produce a membrane and effect an impervious nature of an electrode construction,

wherein both the coating and an impervious material that form the construction are coated on the textile material,

and the conductive coating and the impervious material are placed together overlapping each other in one plane to form the construction, which is both conductive and essentially impervious to moisture.

6. Method in accordance with claim 5, in which a surface of the textile material is vaporized with an electro conductive material to form the conductive electrode surfaces.

7. Method in accordance with claim 5, in which a conductive electrode surface is produced of silver/silver chloride Ag/AgCl.

8. Method in accordance with claim 5, in which a conductive electrode surface is produced of silicon, in which case a diamond surface is created.

9. Method in accordance with claim 5, in which a conductive electrode surface is produced of a material, which is absorbed with a substance improving and/or maintaining moisture and conductivity of the skin.

10. Method in accordance with claim 5, in which electrodes of the electrode surfaces and material surrounding the electrodes are produced of conductive and non-conductive material such that access is prevented of external moisture and impurities between the electrodes and the skin and/or the electrodes are isolated from each other.

11. Method in accordance with claim 5, wherein the fibers of the textile material are first coated by the impervious material and then subsequently coated with the conductive electrode surfaces leaving the open loop areas between the coated fibers.

12. Sensory for measuring signals on the surface of the skin, comprising:

a textile material having loops,

at least one non-conductive material layer which is impervious to moisture fastened by coating on the textile material of an outfit or accessory,

conductive electrode surfaces for measuring signals fastened by coating on the non-conductive material layer configured to be worn on a body directly on the skin,

conductors for transmitting a signal from the conductive electrode surfaces, said conductors fastened by coating on the non-conductive material layer, and

wherein the at least one non-conductive material layer is fastened by coating on the textile material and the conductive electrode surfaces are fastened by coating on the non-conductive material layer such that the loops of the textile material are open.

13. Sensory in accordance with claim 12, wherein the conductors are coated with an isolating material.

14. Sensory in accordance with claim 12, wherein the conductive electrode surfaces and/or the conductors are electro conductive plastics, rubbers or polymers.

15. Sensory in accordance with claim 12, wherein the conductive electrode surfaces are flexible.

16. Sensory in accordance with claim 12, wherein the at least one non-conductive material layer has an area larger than the conductive electrode surfaces.

17. Sensory in accordance with claim 16, wherein the at least one non-conductive material layer surrounds the periphery of the conductive electrode surfaces.

18. Sensory in accordance with claim 12, wherein the conductors are each in electrical connection with a conductive electrode surface.

19. Sensory in accordance with claim 12, wherein the coating of at least one of the conductive electrode surfaces and conductors is a laminated coating.

20. Sensory in accordance with claim 12, wherein the coating of at least one of the non-conductive layer, conductive electrode surfaces and conductors is a vaporized coating.

21. A method for producing sensory for measuring signals on the surface of the skin comprising the steps of;

fastening at least one non-conductive material layer, which is impervious to moisture, by coating on a textile material of an outfit or accessory, said textile material having loops,

fastening conductive electrode surfaces by coating on the non-conductive material layer such that they are configured to be worn on a body directly on the skin,

fastening conductors, for transmitting a signal from the conductive electrode surfaces, by coating on the non-conductive material layer, and

wherein the at least one non-conductive material layer fastened by coating on the textile material and the conductive electrode surfaces are fastened by coating on the non-conductive material layer such that the loops of the textile material remain open.

22. A method according to claim 21, further comprising coating the conductors with an isolating material.

23. A method according to claim 21, wherein the conductive electrode surfaces and/or the conductors are electro conductive plastics, rubbers or polymers.

24. A method according to claim 21, wherein the at least one non-conductive material layer has an area larger than the conductive electrode surfaces which are fastened thereto, and the conductive electrode surfaces are fastened to the non-conductive material layer such that the non-conductive material layer surrounds the periphery of the conductive electrode surfaces.

25. A method according to claim 21, wherein the coating of at least one of the conductive electrode surfaces and conductors is lamination.

26. A method according to claim 21, wherein the coating of at least one of the non-conductive layer, conductive electrode surfaces and conductors is vaporization.

27. A method according to claim 21, wherein the conductive electrode surfaces and/or conductors are fastened to the non-conductive material layer prior to fastening the non-conductive material layer to the textile material.

28. A method according to claim 21, wherein the conductive electrode surfaces are produced by silver/silver chloride or silicon.

29. Sensory in accordance with claim 12, wherein the textile material is a woven textile material.

30. Sensory in accordance with claim 12, wherein the non-conductive material layer and conductive electrode surfaces are coatings of the textile material.

31. A method according to claim 21, wherein the textile material is a woven textile material and the non-conductive material layer and conductive electrode surfaces are coatings of the textile material.