Patent Description:
An electronic device, which measures bio-signals such as ECG (ElectroCardioGram) and EEG (ElectroEncephaloGram), must have the electrodes of a patch electrode well contacted with the skin, and therefore the patch electrode is attached to the skin with an adhesive gel during the measurement.

When a user of the patch electrode sweats or gets otherwise wet, a continuous moisture layer from electrode to electrode on the skin forms an electrical conductor between the electrodes, which causes a short cut of varying impedance. The short cut substantially weakens the measurement signal from the electrodes. In the long run, a cumulative effect of the sweat becomes more and more significant. Additionally, the patch electrode of only one size is not an optimum size for all users. A larger patch electrode, where a distance between the electrodes is longer, would be better for a taller user and a smaller patch electrode, where the distance between the electrodes is shorter, would be better for a shorter user. Furthermore, when a user moves, the patch electrode experiences twisting, compressive and/or stretching forces, which may deteriorate the attachment of the electrodes to the skin despite the adhesive, which, in turn, may disturb the measurement. <CIT> presents a biomedical sensor system and patent document <CIT>presents an extended wear electrocardiography patch using interlaced wire electrodes.

The present invention seeks to provide an improvement in the bio-signal measurements.

All combinations of the embodiments are considered possible if their combination does not lead to structural or logical contradiction.

It should be noted that while Figures illustrate various embodiments, they are simplified diagrams that only show some structures and/or functional entities. The connections shown in the Figures may refer to logical or physical connections. It is apparent to a person skilled in the art that the described apparatus may also comprise other functions and structures than those described in Figures and text. It should be appreciated that details of some functions, structures, and the signalling used for measurement and/or controlling are irrelevant to the actual invention. Therefore, they need not be discussed in more detail here.

<FIG> illustrates an example of an electrode structure <NUM> which provides a bio-signal for a measurement. The electrode structure <NUM> comprises at least two electrodes <NUM>, which are adapted to be adhered on the skin <NUM> (see <FIG>) of a mammal with an adhesive <NUM> (see <FIG>), are separated from each other in a longitudinal direction of the electrode structure <NUM>. The mammal may be a human or an animal. The electrode structure <NUM> may be flat like a sheet. The electrode structure <NUM> may resemble a patch and it may be called a patch electrode. The longitudinal direction refers to a direction that extends parallel to a surface of the electrode structure <NUM> and is different from a direction of thickness of the electrode structure <NUM>. The thickness of the electrode structure <NUM> is small with respect to a square root of an area of the electrode structure <NUM> or even an area of the single side that faces the skin <NUM> during the measurement.

The electrode structure <NUM> also comprises a connector arrangement <NUM> for an electric contact with an external electric device <NUM>, the connector arrangement <NUM> being on an opposite side of the electrode structure <NUM> in a transverse direction of the electrode structure <NUM>. The transverse direction is parallel to the thickness of the electrode structure <NUM>.

In an embodiment an example of which is shown in <FIG>, the electrode structure <NUM> may further comprise electrical conductors <NUM>, which extend in both the longitudinal and transverse directions within the electrode structure <NUM>. The electrical conductors <NUM> are electrically connected with the at least two electrodes <NUM> and the connector arrangement <NUM>.

The electrode structure <NUM> comprises at least one attachable section <NUM> directly adjacent to or in physical contact with one of the at least two electrodes <NUM>, each of the attachable sections <NUM> being adapted to be adhered on the skin <NUM>. The attachable sections <NUM> may be adhered to the skin <NUM> with glue in corresponding manner to the electrodes <NUM>.

The electrode structure <NUM> also comprises at least one loose section <NUM> between as shown in <FIG>. Each of the attachable sections <NUM> is located between one of the at least one electrode <NUM> and one of the at least one loose section <NUM>. Each of the loose sections <NUM> is flexible, elastic, and free from an adherence to the skin <NUM> when the electrode structure <NUM> is applied on the skin <NUM>. That is, no adhesive is used between the skin <NUM> and the loose section <NUM>. The attachable sections <NUM> may be stiff and/or straight. That is, the attachable sections <NUM> may be non-flexible and/or non-stretchable. The attachable sections <NUM> may be the curveless or less curved than the loose sections <NUM>.

The attachable sections <NUM> increase the adherence and thus protect the electrodes <NUM> from forces which are caused by clothes and the movement of the skin <NUM> and which might otherwise loosen the electrodes <NUM> or cause artefacts to the measurement signal.

The attachable sections <NUM> also limit the length of the loose sections <NUM> such that the loose sections <NUM> do not hit or stick with clothes, for example.

In an embodiment, a percentage of a length of a loose section <NUM> and a combined length of attachable sections <NUM> and the loose section <NUM>, which are between any two electrodes <NUM>, which the attachable sections <NUM> are directly adjacent to, may be <NUM> % to <NUM> %. In an embodiment, a percentage of a length of a loose section <NUM> and a combined length of attachable sections <NUM> and the loose section <NUM>, which are between any two electrodes <NUM>, which the attachable sections <NUM> are directly adjacent to, may be <NUM> % to <NUM> %. In an embodiment, a percentage of a length of a loose section <NUM> and a combined length of attachable sections <NUM> and the loose section <NUM>, which are between any two electrodes <NUM>, which the attachable sections <NUM> are directly adjacent to, may be about <NUM> %. In an embodiment, a percentage of a length of a loose section <NUM> and a combined length of attachable sections <NUM> and the loose section <NUM>, which are between any two electrodes <NUM>, which the attachable sections <NUM> are directly adjacent to, may be about <NUM> %.

In an embodiment an example of which is illustrated in <FIG>, the electrode structure <NUM> comprises the at least one loose section <NUM> between the connector arrangement <NUM> and each of the at least two electrodes <NUM>.

<FIG> illustrates an example where the connector arrangement <NUM> comprises separate connectors 102A, 102B, 102C for contacting the external electric device <NUM>. The external electric device <NUM> comprises counter connectors <NUM>, which are suitable for electric and mechanic connection with the connectors 102A to 102C, the electric and mechanic connection being also releasable and potentially repeatable. The connectors 102A to 102C may comprise tool-less connectors, for example. In an embodiment, which is illustrated in <FIG>, the connector arrangement may comprise an USB-connector (Universal Serial Bus), for example.

In an embodiment an example of which is illustrated in <FIG>, the electrode structure <NUM> may comprise a substrate layer <NUM>, <NUM>. The at least two electrodes <NUM> are attached to the substrate <NUM>, <NUM> and are separated from each other in a direction perpendicular to a normal N of the substrate layer <NUM>, <NUM>. The connector arrangement <NUM> may be attached over the substrate <NUM>, <NUM> on the opposite side of the electrode structure <NUM> in a direction parallel to the normal N of the substrate layer <NUM>, <NUM>. The electrical conductors <NUM> may extend in both the perpendicular and parallel directions to the normal N within the electrode structure <NUM>.

The substrate layer <NUM> may be made of threads of woven or non-woven fabric of plant or animal fibers. Additionally or alternatively, the substrate layer <NUM> may be made of felted fabric of plant or animal fibers. The substrate layer <NUM> may be made of textile. The substrate layer <NUM> may be made of breathable, soft and/or skin-friendly material, as it is usual for a gear of a physical activity. The substrate layer <NUM> may be made of non-woven spun lace, for example. The substrate layer <NUM> may be attached to the skin <NUM> with an adhesive <NUM>. That is the substrate layer <NUM> may have glue on both sides in order to have a reliable attachment to both the skin <NUM> and the conductor layer <NUM> where the conductors <NUM> are located. The substrate layer <NUM> at each of the at least one loose section <NUM> has no adhesive against the skin <NUM>, but there may be glue between the substrate layer <NUM> and the conductor layer <NUM>. That is, the substrate layer <NUM> has adhesive only on one side.

In an embodiment, the substrate layer <NUM> may be made of material that does not absorb water. In an embodiment, the substrate layer <NUM> may be made of material that is water repellant. In an embodiment, the substrate layer <NUM> may be made of material that is elastic. In an embodiment, the substrate layer <NUM> may be made of material that has at least one of the properties mentioned above. In an embodiment, the substrate layer <NUM> may be made of polyester liner, for example.

The substrate layer <NUM> comprises the at least one attachable section <NUM> each directly adjacent to or in physical contact with one of the at least two electrodes <NUM>. The substrate layer <NUM> comprises the at least one loose section <NUM> such that each of the attachable sections <NUM> is located between one of the at least one electrode <NUM> and one of the loose sections <NUM>.

<FIG> illustrates an embodiment where a route R along a loose section <NUM> between points P on opposite ends of each of the at least one loose section <NUM> may be longer than a direct distance D between said points P.

In an embodiment an example of which is shown in <FIG>, at least one of the at least one loose section <NUM> may be meandering such that the electrode structure <NUM> has, at the loose section <NUM>, a winding and turning shape.

In an embodiment an example of which is shown in <FIG>, at least one of the at least one loose section <NUM> may have the electrode structure <NUM> zig-zagged. The route R along a loose section <NUM> between the points P on the opposite ends of any of the at least one loose section <NUM> is longer than a direct distance D between said points P.

In an embodiment, at least one of the at least one loose section <NUM> may comprise at least one breakable bridge <NUM>, which materialistically connects length increasing sections <NUM> of the electrode structure <NUM> on opposite sides of at least one turn <NUM> of loose section <NUM>. In an embodiment, the breakable bridge <NUM> may be made of a material which breaks when the loose section <NUM> is stretched using a predetermined force. When the breakable bridge <NUM> breaks, it is cut into two or more pieces.

In an embodiment, the breakable bridge <NUM> may have weakened section <NUM>, which is configured to break when the loose section <NUM> is stretched using a predetermined force. The force of the bridge <NUM> limiting the stretching of the electrode structure <NUM> may be such that a person putting on the electrode structure <NUM> (himself/herself or for other human or animal), feels the limitation in his fingers. The breakable bridge <NUM> may be elastic such that it adapts to a stretch up to a predetermined amount before breaking. In that manner, the person does not stretch the electrode structure <NUM> up to its extreme when applying the electrode structure <NUM> on the skin <NUM>. However, when a person or an animal, which has the electrode structure <NUM> attached on his/her/its skin <NUM>, moves, the movement may result in stretching, twisting and compressing forces to the electrode structure <NUM>, which may cause the at least one bridge <NUM> break letting the loose section <NUM> freely give in to the forces affecting it.

In an embodiment where the conductor layer <NUM> comprises a pattern of the electrical conductors <NUM>, the electric conductors <NUM> are covered with electrically insulating material layer for electrical insulation from the skin <NUM>.

By having at least one loose section <NUM> in the electrode structure <NUM>, sweat and/or moisture cannot easily form a continuous moisture layer between the electrodes <NUM>. Additionally, the electrode structure <NUM> is easy to stretch or compress to an optimum size for users of different sizes. Furthermore, when a user moves, the electrode structure <NUM> experiences twisting, compressive and/or stretching forces, which cause minimized or no deterioration of attachment of the electrodes to the skin because the loose section <NUM> automatically adapts to the forces.

<FIG> illustrates an example of the external electric device <NUM>, which may have a polymer holder <NUM> for a bio-signal processing device <NUM>. The name refers to the fact that the polymer holder <NUM> is made of polymer such as plastic. The bio-signal processing device <NUM> may be an electronic device which may convert an analog bio-signal it receives to a digital bio-signal. The bio-signal processing device <NUM> may also filter the bio-signal in the analog or in the digital form. Additionally or alternatively, the bio-signal processing device <NUM> may perform data processing of the bio-signal, and it may also store data of the bio-signal and/or a result of its processing. The bio-signal may be related to body movement, body temperature, heart rate variability, electrocardiogram, electromyogram, electroencephalogram or the like for example.

The arrow in <FIG> illustrates the feature that the bio-signal processing device <NUM> can be inserted in the polymer holder <NUM>.

In an embodiment an example of which is illustrated in <FIG>, the external electric device <NUM> may include the polymer holder <NUM>, which may comprise a male connector <NUM>. The male connector <NUM> may connect with a female connector <NUM> of the bio-signal processing device <NUM> in response to the insert of the bio-signal processing device <NUM> in the pocket <NUM>.

In an embodiment, the male connector may be a male USB connector (USB = Universal Serial Bus), and the female connector of the bio-signal processing device <NUM> may be a female USB connector. Alternatively, the male connector <NUM> may be in the bio-signal processing device <NUM> and the female connector <NUM> may be in the polymer holder <NUM>. The counter-connectors <NUM> can be coupled with the connector arrangement <NUM> of the electrode structure <NUM>.

<FIG> illustrates an example of the electrode structure <NUM>. One of the loose sections <NUM> has one or more cuts <NUM>, where the electrode structure <NUM> is fully or partly cut in a vertical direction. If the electrode structure <NUM> is fully cut at the cuts <NUM>, the cuts <NUM> will widen into a gap when the loose section <NUM> is under a stretching force. If the electrode structure <NUM> is partly cut at the cuts <NUM>, the cuts <NUM> are like breakable bridges <NUM> (see <FIG>). Still, the cuts <NUM> will widen into a gap when the loose section <NUM> is under a stretching force which breaks the at least one bridge. In an embodiment, at least one of the cuts <NUM> (full or partial) has a round shape, which minimizes the number of sharp edges. The sharp edges may namely break easily. In general, round shapes of the cuts <NUM> are more durable in use.

Another of the loose sections <NUM> has thinner material thickness because of a hole <NUM> in the structure. The thinner material stretches more easily.

Claim 1:
An electrode structure of a bio-signal measurement the electrode structure (<NUM>) comprises
at least two electrodes (<NUM>), which are adapted to be adhered on the skin (<NUM>) of a mammal with an adhesive (<NUM>), are separated from each other in a longitudinal direction of the electrode structure (<NUM>);
a connector arrangement (<NUM>) for an electric contact with an external electric device (<NUM>) on a side of the electrode structure (<NUM>) opposite to that of the at least two electrodes (<NUM>) in a transverse direction of the electrode structure (<NUM>);
electric conductors (<NUM>), which are electrically connected with the at least two electrodes (<NUM>) and the connector arrangement (<NUM>);
the electrode structure (<NUM>) comprises at least one attachable section (<NUM>) directly adjacent to one of the at least two electrodes (<NUM>), each of the at least one attachable section (<NUM>) being adapted to be adhered on the skin (<NUM>);
the electrode structure (<NUM>) comprises at least one loose section (<NUM>) configured to be flexible, elastic, and free from an adherence to the skin (<NUM>) when the electrode structure (<NUM>) is applied on the skin (<NUM>), each of the at least one attachable section (<NUM>) being located between one of the at least one electrode (<NUM>) and one of the at least one loose section (<NUM>), characterized in that
at least one of the at least one loose section (<NUM>) comprises at least one breakable bridge (<NUM>), which is configured to materialistically connect length increasing sections (<NUM>) of the electrode structure (<NUM>) on opposite sides of at least one turn (<NUM>) of the loose section (<NUM>), and
the breakable bridge (<NUM>) comprises a weakened section (<NUM>), which is configured to break, when the loose section (<NUM>) is stretched using a predetermined force.