Heart rate monitoring belt

Abstract

A belt equipped with at least one electrode, for example for heart rate measurement, comprising a stretchable fabric band on which the at least one electrode (6) is directly applied, wherein the at least one electrode (6) is backed at least largely flush with a stretch-resistant, flexible reinforcing fabric (15) and the fabric band is formed from a body-side fabric band layer (18) and an outer fabric band layer (10) with the reinforcing fabric (15) in between, wherein the fabric band layers (10, 18) are each coated on their mutually facing sides with a non-conductive thermoplastic elastomer, and wherein the at least one electrode (6) is formed by an electrically conductive thermoplastic elastomer layer applied over a window (17) in the body-side fabric band layer (18).characterized in that a conductor tape (13) arranged between the reinforcing fabric (15) and the body-side fabric tape layer (18), which consists of a conductive, stretchable material, contacts through the window (17) of the body-side fabric tape layer (18), wherein the conductor tape (13) extends between the fabric tape layers (10, 18) at least from the electrode (6) to a connecting means (5) for connection to a measuring instrument.

Description

[0001] The present invention relates to a belt provided with at least one electrode, for example for heart rate measurement, comprising a stretchable fabric band forming the belt, on which the at least one electrode is directly applied, wherein the at least one electrode is backed at least largely flush with a stretch-resistant, flexible reinforcing fabric, and the fabric band is formed from a body-side fabric band layer and an outer fabric band layer with the reinforcing fabric interposed, wherein the fabric band layers are each coated on their mutually facing sides with a non-conductive thermoplastic elastomer, and wherein the at least one electrode is formed by an electrically conductive thermoplastic elastomer layer applied over a window in the body-side fabric band layer, and a method for its manufacture.

[0002] Such a strap is already described in US 2007 / 0285868 A1. Further reference should be made to US 2004 / 0138546 A1, DE 10 2004 030 261 A1, and DE 11 2004 001 921 T5. The latter is specifically a chest strap formed by an elastic fabric band. The electrodes required for heart rate measurement are attached directly to the elastic fabric band by vapor deposition, using suitable masks. This creates electrode surfaces that can be manufactured with the desired shape and elasticity.

[0003] In principle, the manufacture of a heart rate monitoring belt presents a challenge between the need for the belt to fit the body as precisely as possible and the use of rigid electrodes. For a precise fit, the belt must possess a certain degree of elasticity so that it can be wrapped around the body and, due to this elasticity, fits snugly. This also ensures that the electrodes are positioned as close to the body as possible. Conversely, elastic electrodes make signal analysis more difficult due to the undefined surface area, and their lifespan is significantly reduced by the considerable stress caused by stretching.

[0004] For this reason, belts are also known that have elastic sections alternating with inelastic measuring sections containing electrodes, thus creating both elastic and inelastic areas. However, even with these belts, it can be observed that the fit on the body is not optimal, as the inelastic parts of the belt, which are made of materials such as plastic, do not adhere well and tend to slip.

[0005] Against this background, the present invention aims to create a cost-effectively manufactured heart rate measurement belt which, on the one hand, has the most consistent elasticity possible and, on the other hand, has durable, resilient electrodes which deliver the most accurate measurement results possible.

[0006] This problem is solved with a belt according to the features of claim 1 and a manufacturing method according to dependent claim 7. Further useful embodiments of such a belt and the manufacturing method can be found in the dependent claims.

[0007] According to the invention, a stretchable fabric band is used to manufacture a heart rate measurement belt, which possesses the necessary elasticity. Electrodes are arranged directly on this stretchable fabric band and are backed with a stretch-resistant, flexible reinforcing fabric. The reinforcing fabric behind the electrode is essentially flush with the electrodes, so that the electrodes and the underlying reinforcing fabric, which together constitute a non-elastic area on the surface of the fabric band, remain spatially confined as much as possible.

[0008] In this way, a virtually completely stretchable strap is created from a fabric band, which is only inelastic at specific points around the electrodes. Due to this elasticity, which extends in all directions around the electrode, the elasticity of the fabric band is minimally affected when applied to the body, ensuring a snug and comfortable fit for the user. While the reinforcing fabric is not stretchable, it is flexible, allowing the strap to bend slightly around the electrodes.

[0009] In a further development of such a belt, the fabric webbing can be formed in two layers, using a layer facing the body and an opposing, outer layer. Since both layers are elastic, the elasticity of the overall belt is not affected. This is also ensured by a coating applied to the facing sides of both layers. This coating consists of a non-electrically conductive thermoplastic elastomer, preferably elastic thermoplastic polyurethane. The reinforcing fabric is positioned between these two layers, effectively forming the core of the belt.

[0010] The electrode itself can be made from an electrically conductive thermoplastic elastomer, which is applied to a window in the body-facing fabric band layer using a thermal process. This method of electrode manufacturing ensures that the entire belt production can be carried out using thermal processes, thus enabling simple, fast, and cost-effective production of such a belt. The electrically conductive thermoplastic elastomer layer has a soft, smooth surface, so that artifacts are avoided due to the resulting adhesion between the skin and the elastomer layer, and measurement accuracy is improved.

[0011] To connect the electrode to a measuring device, the belt advantageously has connecting elements which are connected to the electrode via a conductor strip. The conductor strip is a fabric strip made of a conductive textile material, which is also stretchable or elastic. The conductor strip runs beneath the window of the body-side fabric strip layer, so that it is bonded to the electrically conductive elastomer layer when it is applied. The conductor strip extends to a connection point where connecting elements for connecting to a measuring device are provided. Because the conductor strip itself is also elastic, there is an additional elastic section of the belt between the connecting elements and the electrodes.

[0012] The connecting element can be, for example, a metallic snap fastener, which is positioned on the outer layer of the fabric tape and whose counterpart is located in the center of the tape, i.e., above or below the plane of the conductor tape between the two layers of fabric tape. The entire connecting element assembly thus extends, as required, through the conductor tape and the outer layer of fabric tape, as well as a layer of reinforcing fabric that may also be located in the area of ​​the connection center.

[0013] In addition to the electrodes, the connecting elements can also be individually or in groups backed with a reinforcing fabric, thus ensuring greater durability of the strap in this area due to mechanical stress. If a measuring device is directly attached to several connecting elements simultaneously, the loss of elasticity when the connecting elements are arranged in groups on a reinforcing fabric is also negligible, as this elasticity would not be guaranteed by the measuring device anyway. On the contrary, in this case, it is advantageous to use the reinforcing fabric to maintain a constant spacing between the individual connecting elements and thus facilitate the connection of the measuring device.

[0014] For a better fit of the strap and better pressure of the electrode against the body, a cushion can be placed between the reinforcing fabric and the electrode.

[0015] It has proven advantageous to use thermoplastic polyurethane as the elastomer in both the electrode and the inner coating of the fabric tape layers. In the case of the inner coating, this polyurethane layer is non-conductive and capable of effectively insulating the conductor tape between them. The material used for the electrode, however, is electrically conductive polyurethane, produced, for example, by adding electrically conductive components.

[0016] A belt according to the invention typically has a plurality of electrodes, namely usually two or four electrodes.

[0017] To manufacture the belt according to the invention, the cut components are laid on top of each other in the correct position and pre-fixed in this position. Then, the unconnected components of the belt are placed in a heated press and thermally joined there under the influence of pressure and temperature. This makes it possible to manufacture the belt as a whole in a single step, thus making production very cost-effective.

[0018] Depending on the belt's design, the press can be adapted to the specific product being manufactured, in particular by being textured or having an integrated relief die that can be used to imprint a surface structure onto the electrodes. A rough surface structure will provide less adhesion to the skin than a smooth surface, allowing the electrodes to be adapted to specific requirements.

[0019] To accommodate the processing characteristics of different materials, the press can be adjusted by inserting cushions for greater elasticity. The press can also feature a height profile, allowing sections of the belt with varying thicknesses to be subjected to the same force simultaneously. Finally, the press can be operated in different zones at different temperatures, ensuring that each material is processed at its optimal temperature.

[0020] The invention described above will be explained in more detail below using an exemplary embodiment.

[0021] They show Fig. 1 a chest strap with two electrodes and two connecting means in a top view of the extended outer surface and a bottom view of the extended inner surface, each in top view, as well as Fig. 2 a lateral exploded view of the individual layers of the belt according to Fig. 1.

[0022] Fig. Figure 1 shows a top view of the outer surface in the upper section of the image, depicting a measuring section 2 containing the electrodes 6 and the connecting elements 5. In addition to the measuring section 2, the belt 1 has a closure section 3, which can be designed, for example, as a hook-and-loop fastener. The closure section 3 is threaded through a buckle 4 and then secured, for example, by a hook-and-loop fastener. Due to its elasticity, the belt 1 can be easily tightened, ensuring the most precise possible positioning of the electrodes 6 against the body. The connecting elements 5, which are located on the outside in the intended state, allow for the attachment and electrical connection of a measuring device to the belt and the electrodes 6 located therein.

[0023] Fig.Figure 2 shows an exploded view of the various layers of the belt 1, which, with respect to the visible sides, consist of an outer fabric tape layer 10 and an inner, body-side fabric tape layer 18. Both fabric tape layers 10 and 18 are coated on their facing sides with a polyurethane layer 11 and 19, respectively, which act as electrical insulators. The body-side fabric tape layer 18 has windows 17, into the area of ​​which the electrodes 6, consisting of conductive polyurethane, are applied by a thermal process. The window 17 is backed on the opposite side of the electrode 6 with a conductor strip 13, which is connected to the electrode by applying the conductive polyurethane to the window 17 of the body-side fabric tape layer 18. This conductor strip 13 is elastic and then covers the area of ​​the window 17.The electrode 6 connects to a connector 5 and its counterpart 16. The counterpart 16 penetrates the conductor tape 13, forming an electrical contact, and subsequently also the outer fabric tape layer 10 with its polyurethane layer 11. By attaching the connector 5 to the counterpart 16, a continuous electrical connection between the connector 5 and the electrode 6 is established. By connecting a measuring device to the connector 5, the electrical signals received by the electrode can be evaluated. Furthermore, the window 17 is backed with a cushion 14, which provides greater thickness in the area of ​​the electrode 6 and thus enables better pressure of the electrode 6 against the skin when a strap 1 is applied. Finally, a reinforcing fabric 15 is also provided in the area of ​​the window 17, which gives the electrode 6 the necessary durability.Due to the tensile-resistant yet flexible reinforcing fabric 15, deformation of the electrode 6 during the application of the belt 1 to the body is prevented, thus improving the durability of the electrode and increasing the measurement accuracy. Because the electrode 6 and the associated reinforcing fabric 15 are arranged only in a small section of the belt 1, the elasticity of the overall assembly is essentially maintained despite this small, tensile-resistant area. Additionally, another reinforcing fabric 12 can be arranged in the area of ​​the connecting elements 5, and one reinforcing fabric 12 can also connect several connecting elements 5.

[0024] The above description describes a heart rate measurement belt whose electrodes, despite largely maintaining the belt's elasticity, are selectively inelastic to improve measurement accuracy and electrode durability. This is achieved by locally reinforcing the electrodes with a suitable fabric that is flexible yet resistant to stretching. REFERENCE MARK LIST 1 strap 2 measuring section 3 Closure section 4 buckles 5 Connection devices 6 electrode 10 outer fabric tape layer 11 Polyurethane layer 12 reinforcing fabrics 13 ladder band 14 pillows 15 reinforcing fabrics 16 counterpart 17 windows 18 body-side fabric tape layer 19 Polyurethane layer

Claims

[1] A belt equipped with at least one electrode, for example for measuring heart rate, comprising a stretchable fabric band on which the at least one electrode (6) is directly applied, wherein the at least one electrode (6) is backed at least largely flush with a stretch-resistant, flexible reinforcing fabric (15) and the fabric band is formed from a body-side fabric band layer (18) and an outer fabric band layer (10) with the reinforcing fabric (15) in between, wherein the fabric band layers (10, 18) are each coated on their mutually facing sides with a non-conductive thermoplastic elastomer, and wherein the at least one electrode (6) is formed by an electrically conductive thermoplastic elastomer layer applied over a window (17) in the body-side fabric band layer (18). characterized by, that a conductor tape (13) arranged between the reinforcing fabric (15) and the body-side fabric tape layer (18), which consists of a conductive, stretchable material, contacts through the window (17) of the body-side fabric tape layer (18), wherein the conductor tape (13) extends between the fabric tape layers (10, 18) at least from the electrode (6) to a connecting means (5) for connection to a measuring instrument. [2] Belt according to claim 1, characterized by , that the connecting means (5) is a metallic push button which penetrates at least the outer fabric tape layer (10) and the conductor tape (13), the latter with electrical contact. [3] Belt according to one of claims 1 or 2, characterized by , that connecting means (5) of several electrodes (6) are each individually or in groups backed with a reinforcing fabric (12). [4] Belt according to any one of claims 1 to 3, characterized by, that a cushion (14) is placed between the electrode (6) and the reinforcing fabric (15) associated with it. [5] Belt according to any one of claims 1 to 4, characterized by that the thermoplastic elastomer is thermoplastic polyurethane. [6] Belt according to one of the preceding claims with at least two, preferably four electrodes (6). [7] Method for manufacturing a belt according to any one of the preceding claims, characterized by , that all components are first cut to size and arranged on top of each other, after which a thermal bonding of the components takes place as part of a combined heating and pressing process. [8] Method according to claim 7, characterized by , that to imprint a structure onto the electrodes, these are placed underneath with a structure-giving, temperature-resistant stamp or the press is relief-shaped for structure formation. [9] Method according to one of claims 7 or 8, characterized by that components in the press are supported with cushions. [10] Method according to any one of claims 7 to 9, characterized by that the press has a height profile. [11] Method according to any one of claims 7 to 10, characterized by that the press has zones of different temperatures during the combined heating and pressing process.

Images