DE20308658U1 - Electrode element for attachment to human body to pick up signals for electrocardiogram uses suction cup with flexible lips, incorporating flat plate with array of projecting electrodes - Google Patents

Abstract

The electrode plate (16) is circular and generally flat, with an array of shallow projections, with a maximum height of between 0.1 to 2 mm, to make contact with the skin. The suction cup (18) surrounds the electrode and has an inner fastening rim (42), a flexure (44) and a sealing lip (46) engaging a groove (26) in a shoulder (24) on a housing (10). The suction cup has a flexure (48) joining the sealing lip to a conical or bowl-shaped portion (50). A flexure (52) at its outer edge joins it to an inward-extending lip (54). There is a connection for a suction hose (20).

Description

Müller 8s Sebastiani Elektronik GmbH M5466GDE - Mr/Dr/wo

Electrode element for a suction electrode and suction electrode with

an electrode element

The present invention relates to an electrode element for a suction electrode which can be attached to the body surface of a human for recording an electrocardiogram, as well as to a suction electrode with such an electrode element.

In medicine, electrocardiograms are often created to check heart function. Electrodes are used to derive potentials from specified areas on the body surface of the person being examined and fed to an electrocardiograph, which then records or evaluates them. The electrodes must be attached to the skin of the person being examined to ensure sufficient electrical contact between the electrode and the skin.

Adhesive electrodes can be used for attachment. These have a self-adhesive, ring-shaped area around the actual electrode element, for example made of self-adhesive film or foam, by means of which the adhesive electrodes are stuck to the skin of the person being examined. Electrical contact between the skin and the electrode element is usually made using a hydrogel. After the electrocardiogram has been recorded, the adhesive electrodes are removed from the skin and then thrown away.

However, there are also reusable electrodes that are designed as suction electrodes. These suction electrodes have a suction cup element in which an electrode element of the suction electrode is arranged. After the suction electrode is placed on the skin of the person to be examined, a negative pressure is generated in the suction electrode or in the suction cup element, so that the suction electrode is compressed by the higher normal pressure outside the suction electrode, deforming the suction cup element, until the electrode element rests on the skin. The suction electrode is then held on the skin by the negative pressure.

In order to achieve a particularly large contact surface between the electrode element and the skin, known electrode elements have a flat, level contact surface that allows contact with the skin over a large area. In particular, the contact pressure of the electrode element can deform the skin or the layer of fat underneath the skin so that it lies completely against the electrode element and good contact is thus achieved. However, if the surface of the skin is not sufficiently smooth, possibly even after deformation by the electrode element, contact with the electrode element can be impaired. This can either lead to a reduced signal strength or require the use of larger electrode elements, which can then allow a larger contact surface between the skin and the electrode element. However, this has the disadvantage that if the body surface is curved, for example in the area of the ribs, it is not possible to press the skin against the electrode element over the entire surface.

The present invention is therefore based on the object of creating an electrode element for a suction electrode which can be attached to the body surface of a person for recording an electrocardiogram, as well as a suction electrode equipped with such an electrode element, which enables good contact between the electrode element and the skin not only on smooth body surfaces or skin areas.

The object is achieved by an electrode element for a suction electrode having the features of claim 1.

The electrode element according to the invention for a suction electrode which can be attached to the body surface of a human being for recording an electrocardiogram comprises a profiled contact surface which faces the skin during use and has a plurality of blunt elevations, the maximum profile depth being between 0.1 mm and 2 mm.

The object is further achieved by a suction electrode with the features of claim 15, which has an electrode element according to the invention.

In addition, the suction electrode can have a suction cup element that at least partially surrounds the electrode element and is held on a housing of the suction electrode. The interior of the housing and the suction cup element can be placed under a negative pressure via a corresponding vacuum connection on the housing, so that the suction electrode, in particular with the electrode element held on a corresponding holder, is pressed against the upper body.

surface of a person to be examined, whereby the electrode element rests on the body surface or is pressed against it.

The electrode element according to the invention has a profiled contact surface, the maximum profile depth of which is between 0.1 mm and 2 mm. The profiling allows skin irregularities such as small calluses and in particular body hair to be moved into the recesses of the profile between the blunt elevations or the electrode element to be moved accordingly. The movements required for this are so small that a displacement of the skin or the irregularities protruding from the skin and in particular the body hair is usually achieved by placing the electrode element on the surface.

A particular advantage of the electrode element according to the invention is that it is no longer necessary to shave the application site on the skin on which the electrode element is located in order to remove all body hair. Aside from the increased work involved in preparing for an examination, such a shave can also be a cosmetic problem for the patient. An equally important disadvantage of shaving is that shaving usually causes micro-injuries to the skin, which allow pathogens to penetrate. In hospitals or doctor's offices in particular, there is a general risk of infection, particularly with multi-resistant pathogens, so that the avoidability of shaving is a significant advantage of the electrode element according to the invention.

The maximum profile depth can be given in particular by the distance between the highest points of the highest elevations in relation to a base area and the lowest points of the profile in relation to the base area. The base area can be given in particular by a surface that runs parallel to a tangential surface that envelops the contact surface and is tangential to the highest points of the profile. The tangential surface that envelops the contact surface is smooth on the profiling scale. The maximum profile depth of between 0.1 mm and 2 mm allows the above-mentioned bumps on the skin and in particular body hair to be pressed into the profile recesses between the elevations, but also allows the electrode element to remain very flat and the area under the electrode element that needs to be evacuated or put under negative pressure to be kept very small, whereby an overall pressure force generated by the pressure remaining in the suction electrode can be achieved on the electrode element on the body surface.

In addition, a corresponding suction electrode can be very flat, which makes it easier to attach and also allows for a more stable attachment to the body surface, as the center of gravity of the suction electrode can then be closer to the body surface. For significantly greater profile depths, suction electrodes with unacceptably large suction cup elements would have to be used, and in addition, increased negative pressures, which could potentially cause bruising, may be necessary in order to keep the suction electrode in place even when the person being examined is moving.

for example during a stress electrocardiogram.

Finally, the low profile depth in the absence of unevenness also means that the skin of the underlying fat layer, which is typically at least 1 to 2 mm thick, presses into the depressions between the elevations, thus creating a contact surface that is at least as large as a flat contact surface, although depending on the design of the profile, the surface can also be larger.

Because the electrode elements are blunt at their free ends facing the skin, they do not injure the skin of the person being examined, so that infection problems cannot arise. In addition, this also results in greater comfort for the person being examined.

Further developments and preferred embodiments of the invention are described in the description, the claims and the drawings.

In order to achieve the greatest possible number of depressed areas between the elevations, it is preferred that the elevations are arranged next to one another. This results in a knob-like profile that provides depressions in many different directions in a small area between the elevations, so that body hair in particular can be easily pressed into such an area, largely independent of its direction on the skin.

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Furthermore, it is preferred that the profile depth is between about 0.1 mm and 1 mm, preferably between about 0.2 mm and 0.6 mm. The profile depth can in principle vary across the contact surface, whereby a corresponding maximum profile depth can also be derived from this. In particular, a profile depth of less than 1 mm enables a particularly good adaptation of hairless or flat skin to the elevations and the depressions between them, so that a particularly large contact surface can be achieved. This effect is even more pronounced with a profile depth of less than 0.6 mm. On the other hand, the thickness of human hair is between 0.02 and about 0.08 mm, so that if the skin can be easily adapted to the profile, it is possible for body hair to be completely absorbed into the depressions between the elevations, which allows good contact of the skin by the elevations immediately adjacent to the body hair.

In order to achieve good contact even with a larger surface density of skin irregularities and/or body hair, it is preferred that the average number of elevations per area is in the range between about 0.25 per mm ² and 100 per mm ² .

It is particularly preferred that a distance between the highest points of adjacent elevations is greater than about 0.02 mm and less than about 3 mm. The highest points can be understood to be the points that have the smallest distance from the electrode element to the contact surface from a tangential surface enveloping the contact surface. Alternatively, they can be defined by distances from a base surface running parallel to the tangential surface. This results in a comparatively

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dense arrangement of elevations forming a large number of depressions running in different directions.

The elevations, as well as the depressions formed between them, can basically be designed in any way. In order to make production particularly simple, it is preferred that at least some of the elevations are pyramid-shaped or wedge-shaped.

However, it is particularly preferred that the elevations are arranged next to one another and that their upper end sections are each rotationally symmetrical, preferably to a respective axis that is essentially orthogonal to a tangential surface at the highest points of the elevations. This avoids lateral edges that could cause skin injury due to edges on the elevations when pressed onto the skin. In addition, a corresponding design of the elevations allows a very dense arrangement on the electrode surface.

It is particularly preferred that at least some of the elevations have a round end section with an average radius of curvature between 0.1 mm and 0.5 mm. The average radius of curvature is understood to be an average value of the curvatures of the end section at its highest point. By rounding off the end section, injuries to the skin are safely avoided, and the small radii of curvature mean that skin irregularities and in particular body hair can be moved very easily into the depressions formed between the elevations, so that the elevations can come into better contact with the skin surface and overall

a larger actual contact area between the skin and the contact surface of the electrode element is achieved.

Furthermore, it is preferred that adjacent elevations are separated from one another by lines or surfaces that are not or less raised and that are provided by areas between the respective elevations with locally lowest heights, and that the elevations end in the lines or surfaces in a concave curve. In particular, the elevations can have a bell-like shape that allows the skin to adapt particularly well to the contact surface and at the same time also allows for the absorption of skin irregularities and body hair.

It is particularly preferred that the lines or surfaces are oriented tangentially to the surfaces of the elevations. In other words, this means that the elevations merge into one another without the formation of edges at their deepest points, thereby preventing the formation of V-shaped sections in the electrode element. Accordingly, contaminants and in particular bacteria cannot simply settle in corresponding depressions or corners or edges, so that the corresponding electrode element can be cleaned very easily and at the same time thoroughly.

It is further preferred that in a plane intersecting two adjacent elevations in their middle, the two elevations merge into one another to form a concave curvature, and that the curvature has a radius of curvature that is larger than the radius of curvature of the round end section of the elevations, but preferably smaller than 1 mm. In this way, the elevations form

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between them are depressions that are "wider" than the round end sections of the elevations, so that body hair in particular, but also other skin irregularities, can be pushed more easily into the depressions simply by the effect of the elevations when placed on the skin.

Furthermore, it is preferred that the largest angle that the surfaces of at least some of the elevations form with a tangential surface enveloping the contact surface to the elevations is between 30° and 60°. The elevations therefore form a profile whose cross sections show a gently undulating surface. By avoiding surface areas of the elevations that are oriented essentially orthogonally to the tangential surface enveloping the contact surface to the elevations or a base surface running parallel to it, the skin can adapt particularly well to the surfaces of the elevations, resulting in a large actual contact surface between the electrode element and the skin during use. Accordingly, there is also less stress on the skin in the areas that do not have any unevenness or body hair, so that the electrode elements according to the invention are gentler on the skin.

Furthermore, it is preferred that the profile of the contact surface is designed in such a way that a tangential surface to the elevations of the profile is a plane. This allows good contact with the body surface in most areas, since these can usually be considered to be flat in relation to the usual diameters of the electrode elements in the places relevant for electrocardiograms.

The element according to the invention can basically be made up of several pieces. In order to simplify the manufacture of the electrode element according to the invention and to avoid edges or seams where contamination or bacteria could collect, it is preferred that the electrode element is made up of one piece. It can be made entirely from a sufficiently electrically conductive material. However, it is also possible for it to be coated electrically conductively only on the contact surface. However, an electrode element made from an electrically conductive material can also have a highly conductive coating on the contact surface.

In order to be able to use different electrode elements with the suction electrode according to the invention and to facilitate cleaning when used multiple times, it is preferred that the electrode element is detachably held on a holder of the suction electrode. For this purpose, the electrode element can in particular have a corresponding holding section that can be connected directly to the holder or via a corresponding connecting element to the holder.

The electrode element according to the invention and the suction electrode according to the invention thus enable secure contact with the skin surface even in areas where it is not smooth due to skin irregularities or body hair. This avoids any injuries or severe irritations to the skin.

The invention will now be further explained by way of example with reference to the drawings.

Fig. 1 is a schematic sectional view through a suction electrode

with an electrode element according to a preferred embodiment

embodiment of the invention,

Fig. 2 is a schematic perspective view of the electrode element in Fig. 1,
10

Fig. 3 a top view of the contact surface of the electrode

elements in Fig. 1,

Fig. 4 a partial sectional view through the electrode element

in Fig. 1 along a line A-A in Fig. 3

drawn level, and

Fig. 5 is an enlarged view of the circle in Fig. 4

marked area.
20

In Fig. 1, a suction electrode according to a preferred embodiment of the invention comprises a housing 10, an electrically conductive contact pin 14 held therein by means of a holding element 12, an electrode element 16 held on the contact pin 14 and a suction cup element 18 held on the housing 10 and partially surrounding the electrode element 16.

The cap-like housing 10 has a vacuum connection 20 which is connected to an interior of the housing 10 which is open in the direction of the electrode element 16. A vacuum hose to a suction pump can be connected to the vacuum connection 20 in order to provide a vacuum in the housing 10 and the suction cup element 18 which is required for the use of the suction electrode.

Along a circular sector in the interior of the housing 10, a cable clamping groove 22 is formed by a wall section running parallel to a side wall of the housing 10, into which a contact cable guided in the vacuum hose can be inserted or clamped.

The housing 10 further comprises a circumferential shoulder 24 with a retaining groove 26 for the suction cup element 18, in which an annular sealing edge 28 is formed.

In the inside of the circumferential side wall of the housing 10, at the open end of the housing 10, a circumferential groove 30 is formed, into which the holding element 12 can be snapped.

The holding element 12 is locked into the groove 30 of the housing 10 by means of a circumferential first bead 32 in such a way that it cannot be removed from the housing 10 during normal use. 25

Furthermore, an opening 33 is formed in the holding element 12, which connects an area enclosed by the suction cup element 18 with the

Interior of the housing 10 and in particular the vacuum connection 20.

The holding element 12 further comprises a wall section 34 corresponding to the cable clamping groove 22, by means of which the contact cable can be clamped in the cable clamping groove 22.

The contact pin 14 has two circumferential holding flanges 36, by means of which it is held in the housing by the holding element 12 - arranged in a central opening 38 of the holding element 12 and a recess 40 in the front side of the housing 10.

The wire of the contact cable is held in conductive contact in a corresponding opening in the contact pin 12.

The suction cup element 18, which is made in one piece from a flexible silicone-based material, comprises a fastening section 42, a sealing section 46 connected to the fastening section 42 via a first joint section 44, a cup wall 50 connected to the sealing section 46 via a second joint section 48 and a sealing lip 54 movably connected to the cup wall 50 via a third joint section 52.

The suction cup element 18 is held in the holding groove 26 in the shoulder 24 of the housing 10 by means of the fastening section 42. In this case, an end face of the fastening area 42 is pressed against the sealing edge 28, which presses into the flexible material of the fastening area 42.

and thus seals the area inside the suction cup element 18 in the area of the shoulder 24 to the outside.

The joint sections 44, 48 and 52 allow the sealing section 46 to move relative to the fastening section 42, the cup wall 50 relative to the sealing section 46 and the sealing lip 54 relative to the cup wall 50, so that when the suction electrode is placed on an area of the body surface and a negative pressure is applied, the sealing lip 54 and the cup wall 50 are moved towards one another by the pressure difference acting on them compared to the normal pressure outside the suction cup element 18, whereby at the same time large-area unevenness of the body surface, which is caused for example by ribs, can be compensated for.

The electrode element 16, which is only shown schematically in Fig. 1, is essentially designed in the form of a circular disk, but has a truncated cone-shaped holding section 56 with a central locking recess 58 in the middle. The contact pin 14 has a second bead 60 at its end not guided in the housing 10, which can be locked into the locking recess 58 of the electrode element 16, so that the latter is detachably held on the suction electrode.

In Fig. 1, the suction electrode or the suction cup element 18 is in an undeformed resting state, in which the sealing section 46 in a closed position rests all around the circumference of the electrode element 16 and thus seals the interior of the housing 10 against an area enclosed by the suction cup element 18 at a negative pressure

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is sealed in the interior of the housing 10. By moving the housing 10 towards the skin of a person being examined, the suction cup element 18 is compressed or deformed in this direction and the electrode element 16 is placed on the skin. The sealing section 46 is thereby pivoted out of the closed position into an open position and opens up a gap between the electrode element 16 and the sealing section 46, so that the area at least partially enclosed by the suction cup element 18 is connected via the opening 33 to the vacuum connection 20 in the then reached open position and can be placed under a vacuum. The suction electrode is thereby drawn to the body surface while the deformation of the suction cup element 18 is maintained, so that the electrode element 16 is then held resting on the body surface or skin.

The electrode element 16 is shown in more detail in Figs. 2 to 5. It has a profiled contact surface 62 which faces the skin during use and which has a plurality of blunt elevations 66 arranged on a base surface 64. As can be clearly seen in Figs. 2 and 3, the elevations are arranged next to one another and have upper round end sections 68 which are each designed to be rotationally symmetrical to an axis orthogonal to the base surface 64. The radius of curvature of these round end sections is approximately 0.2 mm in the example.

The elevations 66 are separated by areas which run parallel to the base surface 64, partly only in a linear manner.

The maximum profile depth, which is given by the distance between the highest points of the elevations in relation to the base area 64 and the lowest points of the profile in relation to the base area 64 (see Fig. 5), is approximately d = 0.3 mm in the example. In this example, the profile depth is constant over the entire contact surface 62 and thus corresponds to the maximum profile depth. The base area 64 runs parallel to a tangential surface 70 enveloping the contact surface 62, which in the example is given by a plane touching the elevations 66 at their highest points.

In this example, adjacent elevations 64 are only approximately the same distance from each other, as can be seen in Fig. 3. The closest adjacent elevations 66 or their highest points have a distance D of approximately 12 mm from each other (cf. Fig. 5).

Furthermore, the depressions 72 formed by the elevations 66 in the profile of the contact surface 62 are concave and round. In this case, at a point which is the smallest distance from the base surface 64, the tangent to the concave curvature in a plane which runs perpendicular to the base surface 64 through the centers of the two adjacent elevations (see Fig. 5) is parallel to the base surface 64. The radius of curvature of this curvature is larger than the radius of curvature of the end sections 64 and is approximately 0.5 mm in the exemplary embodiment.

The elevations 66 are shaped in such a way that the angles that their surfaces form with the base surface 64 are less than about 45°. This results in a maximum angle between the tangents to the turning points of the surface of an elevation 66 of, as can be seen in Fig. 5,

approximately α = 90°. This corresponds to a maximum angle between the surfaces and the base surface 64, given by the angle between a corresponding tangent to the surface and the base surface 64, of approximately 45°.
5

The electrode element 16 is formed in one piece from an electrically conductive material.

Due to the specified dimensions of the elevations, when the electrode element 16 is placed on a body surface, skin irregularities and in particular body hair can be pushed slightly from the end sections 68 into the area of the depressions 72, where they are sunk relative to a tangential plane parallel to the flat base surface 64 to the end sections 68 of the elevations 66, so that in this area at least the end sections 68 lie unhindered against the skin and thus an electrical contact is provided between the skin and the end sections 68 and thus the electrode element 16.

In the areas of the skin where there are no unevennesses, the skin is pressed into the depressions 72 formed by the elevations 66, resulting in a large contact surface overall, since the skin partially penetrates into the depressions 72 and also rests against the flanks of the elevations 66.

Since the end sections 68 are rounded and thus in particular blunt, no irritation of the skin and in particular no injuries to the skin occur.

Furthermore, the fact that the elevations only form curved depressions 72 without edges or corners prevents contaminants such as sweat, grease or even bacteria from settling in corners and edges, so that simple and thorough cleaning of the electrode element 16 is easily possible.

In another embodiment, a surface enveloping the elevations or their end sections can also be curved and thus not run parallel to the base surface.
10

In another embodiment, the profile depth varies depending on the location on the electrode element.

20

List of references

10 Housing 12 Holding element 14 Contact pin 16 Electrode element 18 Suction cup element 20 Vacuum connection 22 Cable clamping groove 24 shoulder 26 H old nut 28 Sealing edge 30 groove 32 first bead 33 breakthrough 34 Wall section 36 Retaining flanges 38 Center opening 40 Recess 42 Mounting section 44 first joint section 46 Sealing section 48 second joint section 50 Bowl wall 52 third joint section 54 Sealing lip 56 Holding section 58 Recess

60 second bead 62 Contact surface 64 Floor space 66 Surveys 5 68 End sections 70 Tangential plane 72 Deepenings d Tread depth 10 D Distance between neighboring elevations &agr; angle

Claims (16)

1. Electrode element for a suction electrode which can be attached to the body surface of a human being for recording an electrocardiogram, with
a profiled contact surface ( 62 ) facing the skin during use, which has a plurality of blunt elevations ( 66 ),
where the maximum tread depth (d) is between 0.1 mm and 2 mm. 2. Electrode element according to claim 1, characterized in that the elevations ( 66 ) are arranged next to one another. 3. Electrode element according to claim 1 or 2, characterized in that the profile depth (d) is between about 0.1 mm and 1 mm, preferably between about 0.2 mm and 0.6 mm. 4. Electrode element according to one of the preceding claims, characterized in that the average number of elevations ( 66 ) per area is in the range between about 0.25 per mm ² and 100 per mm ² . 5. Electrode element according to one of the preceding claims, characterized in that a distance (D) between the highest points of adjacent elevations ( 66 ) is greater than about 0.02 mm and less than about 3 mm. 6. Electrode element according to one of the preceding claims, characterized in that at least some of the elevations are pyramid-shaped or wedge-shaped. 7. Electrode element according to one of the preceding claims, characterized in that the elevations ( 66 ) are arranged next to one another and their upper end sections ( 68 ) are each rotationally symmetrical, preferably to a respective axis which is substantially orthogonal to an enveloping tangential surface ( 70 ) at the highest points of the elevations. 8. Electrode element according to one of the preceding claims, characterized in that at least some of the elevations ( 66 ) have a round end portion ( 68 ) with an average radius of curvature between 0.1 mm and 0.5 mm. 9. Electrode element according to one of the preceding claims, characterized in that adjacent elevations ( 66 ) are separated from one another by non- or less elevated lines or surfaces which run around them and which are defined by regions between the respective elevations ( 66 ) with locally lowest heights. 10. Electrode element according to claim 9, characterized in
that these elevations ( 66 ) end concavely curved in the lines or surfaces, and
that the lines or surfaces are oriented tangentially to the surfaces of the elevations ( 66 ). 11. Electrode element according to claim 10, characterized in
that in a plane intersecting two adjacent elevations ( 66 ) in their middle, the two elevations ( 66 ) merge into one another to form a concave curvature, and
that the curvature has a radius of curvature which is greater than the radius of curvature of the round end portion ( 68 ) of the elevations ( 66 ), but preferably less than 1 mm. 12. Electrode element according to one of the preceding claims, characterized in that the largest angle which the surfaces of at least some of the elevations ( 66 ) enclose with a tangential surface ( 70 ) enveloping the contact surface ( 62 ) to the elevations ( 66 ) is between 30° and 60°. 13. Electrode element according to one of the preceding claims, characterized in that the profile of the contact surface ( 62 ) is designed such that a tangential surface ( 70 ) to the elevations ( 66 ) of the profile is a plane. 14. Electrode element according to one of the preceding claims, characterized in that it is formed in one piece. 15. Suction electrode with an electrode element according to one of the preceding claims. 16. Suction electrode according to claim 15, characterized in that the electrode element ( 16 ) is detachably held on a holder ( 12 ) of the suction electrode.