RU2597135C2 - Defibrillation electrodes - Google Patents

Abstract

FIELD: medical equipment.

SUBSTANCE: invention relates to medical devices. Reusable component of a hands-free defibrillation electrode comprises a flexible nonconductive element and a flexible reusable metallic element supported by nonconductive element and configured to propagate current of electric defibrillation pulse through an exposure area of 15 square centimetres sufficient for defibrillation. Metal element comprises rigid metal elements interconnected by flexible metal binding elements. Flexible nonconductive material of nonconductive element encapsulates metal element except unsealed sections, which serve as surfaces for current supply into nonconductive material. Through unsealed sections rigid metal elements are open on side of reusable component, which faces patient and may be repeatedly stuck to disposable connecting part. Reusable component has dimensions and is configured to receive electric defibrillation pulse and propagate said and to each of surfaces for current supply, when it is supplied to exposure area in the patient's chest through disposable connecting part. Reusable component is configured for reuse every time with a new disposable connecting part, applied on side of reusable component facing patient.

EFFECT: use of invention provides a flexible electrode which repeats shape of patient's body, but is quite rough, owing to which can be reused.

24 cl, 9 dwg, 3 tbl

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority for provisional application US serial number 61/220946, filed June 26, 2009. This application is incorporated into this description by reference.

FIELD OF TECHNOLOGY

This application relates to the design of hand-held defibrillation electrodes.

BACKGROUND

External defibrillators often include a pair of hands-free disposable electrodes, which are essentially flexible applicators that adhere to a patient’s skin with a cardiac event (i.e., applied transdermally). By “hands-free” we mean electrodes of the type that are glued to the patient, and not flat electrodes that are held by a lifesaver during defibrillation. Non-hand-held disposable electrodes typically include a non-conductive backing layer, a conductive metal layer formed from a thin sheet of metal (e.g., tin or silver) or conductive inks (e.g., silver chloride) printed on a substrate, and liquid or solid conductive a gel covering the metal layer so that an electric current passes through the gel into the patient’s body. The area of contact between the gel and the patient’s body where the current is applied is called the “area of influence" in this description. Since a thin sheet of metal is used in such electrodes, flexibility is limited and repeated use leads to cracking. As a solution to this problem, a wire mesh or a stretched metal plate was proposed, but the wire mesh provides external “noise” during ECG monitoring, and a stretched metal plate is also prone to cracking. Cracking of the metal leads to the formation of an electric arc or the inability to provide the required treatment. As a result, such conventional electrodes are not reusable, require the purchase of electrodes after use and, consequently, increased costs.

External defibrillators also routinely use flat electrodes, such as those disclosed by Scharnberg in US Pat. No. 4,779,630. These flat electrodes are not “hands-free”. Typically, a lifeguard applies liquid gel to the metal surface of the flat electrodes and presses the gel-coated surface onto the patient’s chest during a defibrillation shock. Scharnberg has also disclosed an alternative design in which disposable, gel-containing applicators are attached to the metal surface of flat electrodes. But the rescuer still has to hold flat electrodes with attached applicators on the chest.

One important property of electrodes is that the material used in the metal layer is rapidly depolarized (within seconds) after the defibrillation pulse (“shock”) is supplied to the patient. In other words, the electrode is not able to sense a signal that will allow the defibrillator to generate a clean ECG and determine whether to give another shock within a short period of time.

US Patent Application Publication No. 2008/0221631, the disclosure of which is incorporated herein by reference, discloses that stainless steel and other metals that are polarized during a defibrillation pulse can be used as the conductive metal layer in the defibrillation electrode, provided that the defibrillator with which the electrode is used is configured to provide the patient with a defibrillation pulse signal that is capable of rapidly depolarizing the electrode. Stainless steel is the preferred material for the conductive layer, as it is resistant to corrosion, thus ensuring a long shelf life of the electrode. Also, stainless steel is durable and, therefore, its use in a conductive layer reduces the likelihood that the electrode will be damaged due to improper handling.

Such depolarizing pulsed signals include biphasic waveforms, such as those discussed in detail in US Pat. No. 5,769,872, the disclosures of which are incorporated herein by reference. As disclosed in the previous application, it is believed that the negative phase of the two-phase waveform reduces or eliminates the electric charge, making it possible to quickly depolarize the electrode after applying a defibrillation pulse.

SUMMARY OF THE INVENTION

In a first aspect, the invention characterizes a reusable component of a hands-free defibrillation electrode, the reusable component comprising a flexible non-conductive element and a flexible metal element supported by a flexible non-conductive element, wherein the flexible metal element contains a plurality of substantially inflexible metal elements interconnected by flexible metal bonding elements while most of the flexibility of the metal element is provided by a flexible and metal bonding elements, wherein the flexible metal element has an open surface on one side of the reusable component, and the open surface is adapted to adhere to the disposable connecting part, and the reusable component is configured to receive an electric defibrillation pulse and to propagate the electric pulse through the area of the open surface with which it is fed into the patient’s chest through a disposable connective part.

Preferred embodiments of this aspect of the invention may include one or more of the following. The reusable component can be combined with a flexible disposable connecting part, while the flexible disposable connecting part may contain a conductive layer configured to be in electrical contact with the patient’s chest on one of its surfaces and in electrical contact with the exposed surface of the metal element of the reusable component on another of its surfaces. The reusable component and the disposable part can be arranged to be stored as separate elements and can be glued together when used to defibrillate a patient. The reusable component and the disposable part when bonded together can form an electrode capable of bending simultaneously in more than one direction of bending in order to fit the patient's chest shape. Flexible metal bonding elements can be narrower than essentially inflexible metal elements, and most of the flexibility of the metal element can be achieved by bending narrower flexible metal bonding elements. Essentially inflexible metal elements and flexible metal bonding elements can be cut from the same sheet of metal. The flexible metal element can be made of stainless steel. The flexible metal element may be sealed with a flexible non-conductive element by forming a flexible non-conductive element around portions of the flexible metal element. A flexible non-conductive element may contain an elastomeric material. The conductive layer of the connecting portion may comprise a conductive viscous fluid. The conductive viscous liquid may contain an electrolyte. The conductive layer of the connecting portion may comprise a solid conductive gel. The conductive layer may comprise a hydrogel. The disposable connecting portion may include a first peripheral adhesive region configured to adhere a reusable component to the periphery.

The disposable connecting portion may include a second peripheral adhesive region on a surface opposite the surface bearing the first peripheral adhesive region, wherein the second peripheral adhesive region may be adapted to adhere to the patient’s chest. The first and second peripheral adhesive areas can be generally peripherally outside the area through which electric current flows from the open surface of the reusable component through the conductive layer of the connecting part into the patient’s chest.

The conductive layer of the connecting part may contain a solid conductive gel with adhesive properties sufficient to adhere the connecting part to the patient’s chest. The electrode may further comprise first and second coating films, which, before installing the connecting part in a reusable component, cover the first and second peripheral adhesive regions, respectively. The electrode may further comprise first and second coating films, and before installing the connecting part in a reusable component, the first coating film may cover the first peripheral adhesive region, and the second coating film may cover the solid conductive gel. The reusable component can be combined with a sensor that provides an output signal from which information about the depth of chest compressions during cardiopulmonary resuscitation can be obtained. The sensor may include an accelerometer. The reusable component can be combined with a sensor that provides an output signal from which information about the force exerted on the chest during compression of the chest during cardiopulmonary resuscitation can be obtained. A reusable component can be combined with a sensor that provides an output signal from which information can be obtained on the compression rate of the chest during cardiopulmonary resuscitation. The exposed surface of the metal element may comprise exposed areas of each of the inflexible metal elements.

The metal bonding elements can be completely sealed inside the non-conductive element, so that the open surface contains many open metal areas separated by non-conductive areas. Each of the plurality of exposed metal regions may extend beyond the surface of the surrounding non-conductive element.

In other aspects of the invention, the electrode may comprise a composite structure, wherein the composite structure comprises a conductive metal component that is partially sealed in a non-conductive matrix. The electrode may further comprise a connecting layer. Non-conductive matrix can be flexible. The non-conductive matrix may be an elastomer. The non-conductive matrix may be selected from the group consisting of rubbers, silicone rubber, synthetic rubbers, polychloroprene, thermoplastic elastomers and thermoplastic vulcanizates. The conductive metal component may consist of a metal selected from the group consisting of alloys of stainless steel, tin, silver, silver chloride, aluminum and copper.

Stainless steel alloys can be selected from the group consisting of grades 302, 316 and 316L. The conductive metal component may be flexible. The conductive metal component may comprise a grating of two or more plates connected to each other by jumpers. The conductive metal component may comprise a grating of nine three by three plates connected to each other by jumpers. The plates may be substantially inflexible. Jumpers can be flexible. The electrode may be a medical electrode. Sections of the conductive metal component that are not sealed with a non-conductive matrix may be on the surface of the electrode that faces the patient. Sites can be flat or rounded, or both. The plots may extend beyond the surface of the non-conductive surface.

The area of influence associated with the electrode may be at least 15 sq. Cm. The combined area of action of the apical electrode and the sternum electrode when used in combination may be at least 45 sq. Cm. The area of influence associated with the electrode may be at least 50 sq. Cm. The combined area of action of the apical electrode and the sternum electrode when used in combination may be at least 150 sq. Cm. The metal component may be connected to an external source of electric current. Areas of the conductive metal component that are not sealed may be rounded in shape. The conductive metal component may consist of a single stamped component.

The connecting layer may consist of electrolyte. The connecting layer may consist of a hydrogel. The composite design can be reusable. The connecting layer may be disposable. The connecting layer may be detachably attached to the composite structure. The connecting layer may contain a hydrogel, which can be attached around its perimeter to the adhesive ring. The adhesive ring may be attached to the composite structure outside the area of influence. The connecting layer may be adapted to adhere to the skin of the patient. The bonding layer may be packaged between two coating films before attaching to the composite structure. The electrode may be configured for one or more of defibrillation, electrical signal monitoring, ECG monitoring, pacemaking and cardioversion. The connecting layer may include an additional metal layer in order to allow pacemaking.

Areas of conductive metal that are not sealed with a non-conductive matrix may be located in a 3 by 3 array. The electrode can be attached to a sensor designed to receive data indicating the depth and speed of compression during cardiopulmonary resuscitation. The sensor may be an accelerometer or one or more of pressure and force sensors. Data can be processed by the defibrillator to provide feedback during cardiopulmonary resuscitation.

In other aspects of the invention, the electrode may have a reusable component. A reusable component may comprise a composite structure, wherein the composite structure comprises a conductive metal component that is partially sealed in a non-conductive matrix. Non-conductive matrix can be flexible. The non-conductive matrix may be an elastomer. The non-conductive matrix may be selected from the group consisting of rubbers, silicone rubber, synthetic rubbers, polychloroprene, thermoplastic elastomers and thermoplastic vulcanizates. The conductive metal component may consist of a metal selected from the group consisting of alloys of stainless steel, tin, silver, silver chloride, aluminum and copper. Stainless steel alloys can be selected from the group consisting of grades 302, 316 and 316L. The conductive metal component may be flexible. The conductive metal component may comprise a grating of two or more plates connected to each other by jumpers. The conductive metal component may comprise a grating of nine three by three plates connected to each other by jumpers. The plates may be substantially inflexible. Jumpers can be flexible. The electrode may be a medical electrode.

Sections of the conductive metal component that are not sealed with a non-conductive matrix may be on the surface of the electrode that faces the patient. Sites can be flat or rounded, or both. The plots may extend beyond the surface of the non-conductive surface. The area of influence associated with the electrode may be at least 15 sq. Cm. The combined area of action of the apical electrode and the sternum electrode when used in combination may be at least 45 sq. Cm. The area of influence associated with the electrode may be at least 50 sq. Cm. The combined area of action of the apical electrode and the sternum electrode when used in combination may be at least 150 sq. Cm. The metal component may be connected to an external source of electric current. Areas of a conductive metal component that are not sealed may be rounded in shape.

The conductive metal component may consist of a single stamped component. The reusable component may additionally be used with a disposable component that contains a bonding layer. The connecting layer may consist of electrolyte. The connecting layer may consist of a hydrogel. The connecting layer may be detachably attached to the composite structure. The connecting layer may contain a hydrogel, which can be attached along its perimeter to the adhesive ring. The adhesive ring may be attached to the composite structure outside the area of influence. The connecting layer may be adapted to adhere to the skin of the patient. The bonding layer may be packaged between two coating films before attaching to the composite structure. The electrode may be configured for one or more of defibrillation, electrical signal monitoring, ECG monitoring, pacemaking and cardioversion. The connecting layer may include an additional metal layer in order to allow pacemaking.

Areas of conductive metal that are not sealed with a non-conductive matrix may be in the form of a 3 by 3 lattice. The electrode can be attached to a sensor designed to receive data indicating the depth and speed of compression during cardiopulmonary resuscitation. The sensor may be an accelerometer or one or more of pressure and force sensors. Data can be processed by the defibrillator to provide feedback during cardiopulmonary resuscitation.

In yet another aspect of the invention, the electrode may be configured to use an “hands-free” electrode and to deliver a defibrillation pulse to a patient. In alternative embodiments, the electrodes are also configured to monitor electrical signals from the patient’s body and to deliver a defibrillation pulse having a waveform configured to substantially depolarize the metal. By "substantially depolarization" is meant that polarization is eliminated or significantly reduced, so that the defibrillator can read a clean ECG.

Other features and advantages of the invention will be found in the detailed description, drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A-1E are front, back, and side views of a composite electrode structure in accordance with one embodiment of the invention.

FIG. 2A-2B are illustrations of how a connector assembly can be attached to a composite structure.

FIG. 3A-3I are illustrations of various aspects of a conductive metal component (including the possibility of simultaneously bending the component in more than one bending direction in order to conform to the shape of the body).

FIG. 4A-4E are illustrations of various aspects of an alternative metal component.

FIG. 5A-5B are illustrations of an alternative metal component.

FIG. 6A-6C are illustrations of how a bonding layer can be connected to a composite structure.

FIG. 7A-7C are illustrations of electrodes in an alternative embodiment of the invention in which a sensor is integrated in the electrode assembly.

Fig. 8 is a waveform that can be used in connection with the electrodes of the invention.

Fig.9 is a diagram of a circuit suitable for generating the waveform of Fig.8.

DETAILED DESCRIPTION

There are a large number of possible embodiments of the invention, too large to be described herein. Some possible implementations that are currently preferred are described below. However, it cannot be emphasized that these are descriptions of embodiments of the invention, and not a description of the invention, which is not limited to the detailed embodiments described in this section, but described more generally in the claims.

As discussed above, a hands-free electrode typically includes a non-conductive back layer, a conductive layer formed of a thin sheet of metal or conductive ink printed on a substrate, and a bonding layer, typically a liquid or solid conductive gel or other electrolytic material, a covering metal layer so that an electric current passes through the gel (or other electrolyte) into the patient’s body. It also contains a wire connecting the electrode to the defibrillator. It is well known that two electrodes are used in defibrillators, usually called the sternum and apical electrodes.

The embodiment of the electrode disclosed below differs from the electrode described above in that it includes a reusable component having a composite structure comprising a conductive metal component that is partially sealed in a non-conductive matrix material (for example, by molding a non-conductive material around at least least areas of the conductive metal component). The disposable connecting portion is glued to the reusable component to form a hands-free electrode for delivering defibrillation currents to the patient.

FIG. 1A-1E depict one embodiment of the composite structure announced above. In FIG. 1A, the composite structure 100 includes an electrically non-conductive matrix 105 (one embodiment of the “flexible non-conductive element” referred to elsewhere) that seals a portion of the conductive metal component. The composite structure has a sealed high voltage wire 150 for connection to a power source such as a defibrillator. The wire may be connected by a loop or other connecting means, as discussed below, to a metal component. The conductive metal component will be separately described in more detail below. Those portions 110 of the metal component that are not sealed in the matrix are located on the upper surface (patient side) of the composite structure and supply electric current to the patient through an electrolyte or other conductive viscous fluid (not shown) that is between the composite structure and the patient. Accordingly, these portions 110 may be referred to herein as “open surfaces” or “current-supplying surfaces”. The contact area of the current supply surface may be inflexible, and the uppermost surface may be flat.

The composite structure is designed so that the area of influence (illustrated by region 115 within the dashed line in FIG. 1A as an example) can be at least 2.33 square meters. inches (15 sq. cm) with a combined area of influence associated with two electrodes (sternum electrode and apical electrode) of 6.98 square meters. inches (45 sq. cm) for pediatric electrodes; and 7.75 square inches (50 square cm), with a combined exposure area associated with two electrodes (sternum electrode and apical electrode) of at least 23.25 square inches (150 square cm) for all other electrodes, in accordance with AAMI DF-80 and international requirements.

In a preferred embodiment, the exposure area associated with each pediatric electrode is 7.56 square meters. inches (22.5 sq. cm), and for all other electrodes 11.63 square inches (75 square cm) per electrode. The area outside the impact area 115 (which consists of a non-conductive matrix) should be large enough to prevent lateral discharge of current into the outer edge of the electrode and to allow the adhesive ring to be attached to which a bonding layer such as a hydrogel is attached. As can be seen in FIG. 1B, which depicts the lower surface of the composite structure (opposite the patient side), the conductive metal component is completely coated with a non-conductive material of sufficient thickness so that no electric current passes through the lower surface. FIG. 1C is a longitudinal side view of a composite structure. FIG. 1D is a side view of a composite structure. FIG. 1E is an exploded view of the rounded section B in FIG. 1D. As can be seen (and as will be discussed in more detail below), the current-supplying surfaces 110 of the composite structure 100 may extend beyond the surface of the non-conductive matrix 105. As can be seen by the dashed lines in FIG. 1D and 1E (in more detail), the conductive metal component 120 (described in more detail below) can be partially mounted in the non-conductive matrix 105. A portion of the current-supplying surface that extends beyond the surface of the non-conductive matrix corresponds to step 375 (shown in Fig. 3D) . Thus, the non-conductive matrix can extend up to the top of the ledge 365 (shown in Fig. 3) or as shown by the number 120.

Alternative dimensions (length and width) for the metal component, impact area and composite structure are given below. It should be noted that these dimensions reflect composite structures (as well as metal components) with the same length and width, which is preferred for manufacturing and packaging. However, the invention is not limited to such sizes and is applicable to electrodes of any size (with the same or not length and width) or shape (for example, round, oval, rectangular or other shapes well known in the art), provided that the area of influence is large enough for defibrillation or cardioversion and the minimum exposure area standards specified in the AAMI DF-80 and stipulated by the regulations are met. For example, instead of having an electrode made for an area of influence that is 2 inches by 2 inches, an electrode could be made for an area of impact that is one inch by four inches. Of course, the apical and sternal electrodes can be of a different size and shape.

Table 1 shows non-limiting examples of possible size ranges (length and width) for pediatric electrodes, and Table 2 shows non-limiting examples of possible size ranges (length and width) for other non-pediatric electrodes.

Table 1 Pediatric Electrode - Size Range (inches) Preferred More preferred Even more preferred Min Max Min Max Metal component 1.5 × 1.5 3 × 3 2 × 2 3 × 3 2.5 × 2.5 Area of impact 2 × 2 3.5 × 3.5 2.5 × 2.5 3 × 3 2.75 × 2.75 Composite construction 2.5 × 2.5 5 × 5 3 × 3 4 × 4 3.5 × 3.5

table 2 Pediatric Electrode - Size Range (inches) Preferred More preferred Even more preferred Min Max Min Max Metal component 3 × 3 4 × 4 3 × 3 3.5 × 3.5 3 × 3 Area of impact 3.5 × 3.5 4,5 × 4,5 3.5 × 3.5 4 × 4 3.5 × 3.5 Composite construction 4 × 4 7.5 × 7.5 5 × 5 6 × 6 5 × 5

It should be noted that the dimensions of the impact area in either direction of length and / or width are preferably no larger than the dimensions of the composite structure in the same one or more directions.

Table 3 below illustrates alternative thicknesses for a composite structure. The thickness of the structure should take into account at least the following: (a) the thickness of the non-conductive material should preferably be sufficient to prevent the passage of current (for example, the current only leaves the electrode on the current-supplying surfaces; (b) the electrode should preferably be thin enough to be flexible and thick enough to be strong; (c) the wall thickness should preferably be thick enough to form the composite structure; and (d) sufficient surface area for the metal to bond Ia with a nonconducting matrix. The thickness may taper to an outer edge of the composite structure.

Table 3 Size Range (inches) Preferred More preferred Even more preferred Min Max Min Max Thickness within the affected area 0,063 0.250 0,094 0.188 0.125 Thickness Outside 0,032 0.125 0,047 0,094 0,063

FIG. 2A and 2B illustrate an embodiment of the electrode described above, which depicts how a composite structure connects to a bonding layer. As shown in FIG. 2A (exploded view), the connection assembly 200 (one possible embodiment of the “disposable connection part” referred to elsewhere), consisting of an adhesive ring 210 and containing a hydrogel 220, can be adhered to the composite structure 230. In FIG. 2B shows an assembled electrode structure. The adhesive ring 210 may also include an adhesive on the patient side for attaching the electrode to the patient. It should be mentioned that the connecting unit 200 may be disposable, while the composite structure may be reusable, as will be discussed in more detail below.

FIG. 3A depicts an embodiment of a construction of a conductive metal component 300. The conductive metal component 300 includes nine rounded three-to-three grid plates 310, each plate being connected by a metal bridge 320 (one possible implementation of the “metal bonding element” referred to in elsewhere) with one or more adjacent plates. The sizes 350, 355, 360, 370, 380, and 390 of the grating are determined by the total size of the electrode and the width of the area outside the area 115 exposure (shown in Fig.1A). Jumpers can be flexible. A loop 330 may be attached to one or more plates or jumpers. This loop provides the ability to attach a high voltage wire for defibrillation, and in alternative embodiments, for monitoring an electrical signal, ECG monitoring, cardiac pacing and / or cardioversion.

Flanges 340 may be added to the edges of the plates to increase the range of the metal mounted in the non-conductive matrix. FIG. 3B is a side view of the grating of FIG. 3A; wherein FIG. 3C and 3D depict detailed interpretations of circled areas. As can be seen from FIG. 3B-3D, the plates have a step design with steps of 365 and 375. Although a single step could be used (leading to the surface of a metal component that is flush with the non-conductive surface), using multiple steps provides certain advantages, such as improved attachment of the metal component to the non-conductive matrix (which can fill the area under the metal component and the area between each plate (above the jumpers) to the top of the ledge 365) and more lung overmolding a metal component with a non-conductive matrix. The step 375 allows the plate to protrude above the level of the non-conductive matrix, which provides improved contact with the connecting layer and improved fixation of the connecting layer with the composite element over the area of influence. In particular, in some aspects, the height of the second ledge (375) correlates with the thickness of the adhesive ring holding the connecting layer so that the surface of the connecting layer that is in contact with the patient is aligned, thus ensuring uniform application of current throughout the area exposure.

In a non-limiting example, with reference to FIG. 3A-3D, each of sizes 355 and 350 is three inches; size 360 (diameter of the current supply surface) is 0.813 inches (2.065 cm); size 370 is 0.063 inches (0.160 cm) and size 380 is 0.25 inches (0.635 cm). Sizes 315, 325, 335, 345 and 355, which represent the thickness of the metal at selected points on the grill, are 0.005 (0.013 cm) inches. The height of the ledge 365 is 0.063 inches (0.160 cm) and the height of the ledge 375 is 0.031 inches (0.787 cm).

FIG. 3E-3I illustrate the flexibility of the metal component of a three by three lattice described above. As described above, the flexibility of the metal component can be achieved due to the flexibility of the jumpers.

The metal component is not limited to the specific embodiments described above; instead, the metal component may have two or more current-supplying surfaces. For example, FIG. 4A depicts one embodiment of a construction of a conductive metal component 400 that includes three substantially inflexible rounded plates 410, with each plate connected via a metal bridge 420 to one or more adjacent plates. Jumpers can be flexible. A loop 430 may be attached to one or more of the plates or jumpers. This loop provides the ability to attach a high voltage wire for defibrillation. In certain embodiments, the same wire can be used to monitor an electrical signal, ECG monitoring, pacemaker and / or cardioversion. Another means for attaching wires for defibrillation, ECG monitoring, cardiac pacing and / or cardioversion may be used. Flanges can be added to the edges of the plates to increase the metal coverage in the non-conductive matrix.

FIG. 4B-4E illustrate the flexibility of a conductive component having three plates. In these figures, it can be seen that flexibility is obtained from the jumpers between the plates.

The thickness of the metal in the metal component can be on the order of 0.004-0.008 inch (0.010-0.020 cm). In one embodiment, the thickness is 0.005 inches (0.013 cm). The metal must be thick enough to provide durability and ease of manufacture, in addition, thin enough to provide the flexibility of the composite structure, sufficient to match the patient's body. The gap between the plates should be narrow enough so that when used in combination with the connecting layer, the longitudinal conductivity of the connecting layer produces a substantially uniform distribution of current on the interface between the connecting means and the patient’s skin over the affected area (for example, the electrode “functions” as a single plate instead of, for example, nine separate plates with reference to Fig. 3A). As indicated above, the area of influence should have a surface area large enough for defibrillation or cardioversion.

In one embodiment, the metal component is stainless steel. Suitable stainless steel alloys include, for example, grades 302, 316, 316L and alloys having a similar composition. Other metal alloys may be used. The metal component may also be made of tin, silver, aluminum, silver chloride, copper or another metal or combinations of metals (e.g. silver-plated copper) and may be in the form of metallic or conductive inks (e.g. silver-silver) located on a suitable substrate, such as polyester, which is known to those skilled in the art. In an alternative embodiment, the metal component consists of any metal that is polarized during the application of the defibrillation pulse. When such a metal is used, it is preferable to use it in combination with a waveform that essentially depolarizes the electrode within 6 seconds of applying a defibrillation pulse.

The metal component may be the only stamped part and be calcined for flexibility and to minimize the presence of brittle joints. The use of a single stamped part facilitates processing and reshaping and eliminates the need for welding or soldering jumpers and / or plates. Alternatively, the component may be made of a plurality of plates that are welded or brazed together, or which are mechanically bonded.

In yet another alternative embodiment, the wires may be connected directly to separate current supply surfaces. This would lead to good flexibility of the composite structure, but would be more difficult to manufacture. Wires can be arranged in a grid to optimize connectivity by creating redundant connections without compromising flexibility. The wires must be connected to the high voltage cable in a common node.

In yet another alternative embodiment, a flexible circuit with a printed conductive element may be used instead of the metal component described above.

In FIG. 5A and 5B, an additional embodiment is illustrated. As shown in FIG. 5B, individual (non-circular; although any shape may be used) conductive plates 510 are attached to the conductive back layer 520 (which may be flexible) via attachment points 530. A connection point 540 for a wired connection with a defibrillator is located inside the conductive back layer 520.

As indicated above, the metal component is partially sealed in an electrically non-conductive matrix. This can be done by molding the metal component inside the elastomer. The forming of the metal component inside the elastomer can be accomplished by any suitable method known to those skilled in the art. Such methods may include injection molding, reshaping, and insert molding. The constituent element may also be made by sandwiching a metal component between two (or more) parts of the non-conductive matrix and gluing the parts of the non-conductive matrix together. The metal can be passivated to remove any surface contaminants, a heat-activated adhesive is added to the metal (e.g., Chemlock 608, available from Lord Corporation, Cary, NC, USA) at the places where the elastomer will come into contact with the metal, while the elastomer is bonded with metal by hot vulcanization.

As a non-conductive matrix, any flexible elastomer or rubber may be used. These materials may have one or more of the following properties: flexibility, wear resistance, resistance to chemicals such as detergents and disinfectants (e.g. bleach, alcohol and glutaraldehyde), resistance to extreme temperatures, biocompatibility (e.g., corresponding to ISO 10993 ) and good bonding with metal. Such materials may include silicone rubber (e.g., Elastomer C6-150 class VI, available from Dow Corning Corporation, Midland, MI USA), synthetic rubbers (e.g. Neoprene polychloroprene, available from DuPont Performance Elastomers, Wilmington, DE, USA) thermoplastic elastomers (e.g. Sarlink plastics and rubbers available from DSM Termoplastic Elastomers, Inc. Heerlen, NL); or thermoplastic vulcanizates (TPVs) (e.g., Santoprene TPV, available from ExxonMobil, (Houston, TX, USA)), but are not limited to this.

The connecting layer may be located on the patient side of the electrode. In one embodiment, the connecting layer is attached to an adhesive ring, which is configured to adhere the electrode to the skin of the patient, and the connecting layer to the electrode. The connecting layer may also be interlaced between two adhesive rings. The bonding layer and the adhesive ring together form a modular bonding assembly. The connecting unit is generally disposable, i.e. It is discarded after a single use. The adhesive ring may include a pressure-sensitive adhesive that connects the non-conductive matrix connector assembly detachably beyond the region where the metal component protrudes through the non-conductive matrix. The perimeter of the adhesive ring may correspond to the perimeter of the composite element, which is outside the area 115 of the impact (see Fig. 1A), which in some embodiments, may be approximately 3/4 inch in width. It is necessary to mention that the sticky ring can act, in this respect, like a mask around the area of influence.

In one embodiment, the adhesive ring may consist of 5 mil low density polyethylene (LDPE) (DV216-127A, available from Lohmann Therapy Systems, West Caldwell, NJ) or 1/32 inch polyethylene (PE) foam (Part No. 22116, also available from Lohmann Therapy Systems). Both LDPE and PE provided by Lohmann Therapy Systems are coated with a pressure sensitive adhesive for use in medicine (solvent based acrylic adhesive MTC 611). Alternatively, the bonding layer may be sandwiched between the LDPE layers or PE layers disclosed above, or combinations thereof. Once the used connector has been removed, it can be replaced with a new one, allowing reuse of the composite structure. The composite design can be used for 100 applications or more, providing significant cost savings compared to pre-existing electrodes. Accordingly, the adhesive and materials for the non-conductive matrix should be selected so as to provide sufficient bonding with the non-conductive matrix, but to minimize the residue on the non-conductive matrix after removal of the connecting node to allow reuse of the electrode. The joint assembly may have a removable coating film on one or both sides to protect the joint layer before use.

FIG. 6A-6C illustrate the foregoing in more detail. FIG. 6A is an exploded view of an electrode before attaching a connection assembly. In particular, the connecting layer 630 is attached to the adhesive ring 640, then sandwiched between the removable films (also referred to as cover films) 620 and 650. The multi-layer construction allows the joint assembly to be separately packaged, which makes it possible to sell the joint assembly separately (as a disposable product) from a composite structure, which, as indicated above, can be reusable. In practice, a disposable joint assembly is removed from its packaging, the film 620 is removed, and the adhesive ring carrying the joint layer is glued to the composite structure. The film 650 is then removed and the electrode is attached to the patient.

The bonding layer can be any type of electrolyte (or other conductive material) in gel or liquid form, and it can optionally be attached to a carrier. In some embodiments, the bonding layer comprises a high viscosity conductive gel (often referred to as a “solid” gel) or a hydrogel. Such hydrogels may include FW340 hydrogel (available from First Water Ltd., Wilshire, UK); AG604 hydrogel (available from Axelgaard Manufacturing Co., Fallbrook, CA); and RG63T hydrogel (available from Ludlow Manufacturing, Chicopee, MA). Alternatively, a layer of foam, cloth or sponge saturated with an electrically conductive liquid (e.g., saline) or gel may be used. When the electrode is to be used for pacemaking, additional metallic material (such as tin) should be added to the connecting layer between the electrolyte and the surface of the composite element.

In another embodiment, the adhesive ring is eliminated, and the connecting layer can be attached directly to the area affected by the electrode. In an alternative embodiment, the liquid gel may be applied either directly to the electrode or directly to the patient before placing the electrode on the patient. Then, you can use tape to attach the electrode to the body.

The electrodes described herein can be implemented as a multi-purpose defibrillator electrode, i.e. suitable for monitoring electrical signals from the patient, as well as for defibrillation, pacemaking and cardioversion. For example, after applying a defibrillation pulse, the electrode is configured to monitor a signal that can be used to create an ECG.

In FIG. 7A-7C illustrate a further embodiment. It should be noted that in these figures, the perspective is not shown from the patient’s electrode side. Therefore, in FIG. 7A, the metal component is delineated by a false contour, and wire bundles are provided for illustrative purposes only. In this embodiment (see FIGS. 7A and 7B), a sternum electrode 700 having the characteristics described above and configured for one or more of electrical signal monitoring, ECG monitoring, defibrillation, pacemaker and / or cardioversion is connected to a sensor (or sensors) 710, designed to obtain data indicating the depth and speed of compression during cardiopulmonary resuscitation. The sensor may be one or more of an accelerometer or force and pressure sensors. The system is adapted to provide feedback during cardiopulmonary resuscitation (in one mode in real time) to a patient carer. The functionality of the electrode and accelerometer is as described in the publication of US patent application 2006/0009809, the disclosure of which is incorporated herein by reference. The cardiopulmonary resuscitation sensor can be molded together with the composite structure using the molding methods described above. The wiring 720, necessary for the feedback functionality in cardiopulmonary resuscitation, can be formed into a non-conductive matrix material connecting the sensor 710 to the electrode 700, and bundled with a high voltage wiring 730 for connection via a combination beam 740 with a defibrillator (not shown) . It is noteworthy that for the purposes of this embodiment, the apical electrode 780 illustrated in FIG. 7C does not have additional feedback functionality for cardiopulmonary resuscitation.

As indicated above, the electrodes described above in this application can be used with any type of waveform known in the art. One such waveform is a biphasic waveform. An example of a two-phase waveform is shown in FIG. 8. The biphasic waveform 80 shown in FIG. 8 includes a generally rectilinear positive phase 82 having a sawtooth ripple 84. The positive phase current is approximately 9 amperes. The positive phase has a duration of approximately 6 milliseconds. The positive phase is followed by the negative phase 86. The negative phase has a duration of 4 milliseconds and has an initial current of approximately -8 amperes. The transition 88 between the positive and negative phases is generally very short, for example 0.1 milliseconds or less.

The waveform shown in FIG. 8 is just one example of a suitable waveform. Other waveforms having various characteristics may be used, including both biphasic waveforms having other waveforms and other types of waveforms. Preferably, the waveform used in combination with the electrode described in this application is able to depolarize the electrode (i.e. either completely depolarize the electrode or reduce the polarization to a level where a pure ECG can be obtained) within a few seconds, for example 4- 6 seconds or less after applying a pulse, as described in the publication of US patent application 2008/0221631 mentioned above. This provides an opportunity for the rescuer to continue treatment of the patient without interruption.

The waveform can be generated in any desired manner, for example using the circuit described in US Pat. No. 5,769,872. With reference to FIG. 9 in this description, which is a reproduction of FIG. 2 of US Pat. No. 5,769,872, the storage capacitor 20 ′ (115 μF) is charged to a maximum value of 2200 volts by means of a charging circuit 22 ′, while the relays 26 ′ and 28 ′ and the H-jumper are open, and then the electric charge stored in the storage capacitor 20 ', allow passage through the electrodes 21' and 23 'and the patient's body 24'. In particular, the relay switches 17 ′ and 19 ′ are opened, and then the relay switches 26 ′ and 28 ′ are closed. Then, the electronic switches 30 ', 32', 34 'and 36' of the H-jumper 48 'are closed to allow electric current to flow through the patient's body in one direction, after which the electronic switches 30', 32 ', 34', and 36 ' H-jumpers are opened, and switches 38 ', 40', 42 ', and 44' of the H-jumpers are closed to allow the passage of electric current through the patient's body in the opposite direction. Electronic switches 30'-44 'are controlled by signals from respective optical isolators, which, in turn, are controlled by signals from microprocessor 46' or alternatively from a hardware-implemented processor circuit. Relay switches 26 'and 28', which are also controlled by microprocessor 46 ', isolate the patient 24' from the leakage currents of the jumper switches 30'-44 ', which can be approximately 500 microamps. Relay switches 26 'and 28' can be relatively inexpensive due to the fact that they do not have to "hot-swap" the current pulse. They close a few milliseconds before the H-jumper 48 'is lit by closing some of the H-jumper switches.

Optionally, an active resistance circuit 50 is provided in the current circuit, which includes series resistors 52, 54 and 56, each of which is connected in parallel with a switch 58, 60 and 62 with overlapping contacts controlled by microprocessor 46. Resistors have an unequal value varying in binary sequence to obtain 2 ⁿ possible resistances, where n represents the number of resistors. During the initial “sensor pulse”, when the 30 ', 32', 34 ', and 36' switches of the H-jumper are closed, all of the resistor switches 58, 60, and 62 with overlapping contacts are open, so that current flows through all resistors. The current-sensitive transducer 64 senses the current passing through the patient 24 ', from which the microprocessor 46 determines the resistance of the patient 24'.

Other embodiments of the invention are within the scope of the claims.

Claims (24)

1. Reusable component (100) glued defibrillation electrode containing:
a flexible non-conductive element (105), and
a flexible reusable metal element (120, 300) supported by a flexible non-conductive element (105) and configured to propagate the current of an electric defibrillation pulse through an exposure region sufficient for defibrillation of at least 15 square meters. cm,
however, the flexible metal element contains many essentially inflexible metal elements (310) interconnected by flexible metal bonding elements (320),
moreover, the flexible non-conductive element contains a flexible non-conductive material, essentially an encapsulating metal element with the exception of many unsealed portions, which serve as surfaces for supplying current in a non-conductive material through which the essentially inflexible metal elements are open on the side that faces the reusable patient component
moreover, the side that faces the patient is configured to provide multiple adhesion to the disposable connecting part (200),
wherein the reusable component is sized and configured to receive an electric defibrillation pulse and propagate this electric pulse to each of the surfaces for supplying current when it is delivered to the patient’s chest through a disposable connecting part, and
wherein the reusable component is configured for reuse, each time with a new disposable connecting portion applied to the side that faces the patient of the reusable component. 2. The reusable component according to claim 1, combined with a flexible disposable connecting part (200) to form a defibrillation electrode, in which the flexible disposable connecting part comprises a conductive layer configured to electrically contact one of its surfaces with the chest of the patient and make electrical contact with the side that faces the patient, a flexible reusable component (100) on another of its surfaces. 3. The reusable component according to claim 2, wherein the reusable component (100) and the disposable connecting part (200) are configured to be stored as separate elements and glued together when used to defibrillate a patient. 4. The reusable component according to claim 2, wherein the reusable component (100) and the disposable part (200), when bonded, form an electrode capable of bending simultaneously in more than one direction of bending in order to fit the patient's chest shape. 5. The reusable component of claim 1, wherein the flexible metal bonding elements (320) are narrower than the substantially inflexible metal elements (310). 6. The reusable component of claim 1, wherein the substantially inflexible metal elements (310) and flexible metal bonding elements (320) are cut from the same metal sheet. 7. The reusable component of claim 1, wherein the flexible metal element (120, 300) is made of stainless steel. 8. The reusable component of claim 6, wherein the flexible metal element is made of stainless steel. 9. The reusable component of claim 1, wherein the flexible non-conductive element comprises an elastomeric material. 10. The reusable component of claim 2, wherein the conductive layer of the connecting portion comprises a conductive viscous fluid. 11. The reusable component of claim 10, wherein the conductive viscous liquid contains an electrolyte. 12. The reusable component of claim 2, wherein the conductive layer of the connecting portion comprises a solid conductive gel. 13. The reusable component of claim 12, wherein the conductive layer comprises a hydrogel. 14. The reusable component of claim 2, wherein the disposable connecting portion comprises a first peripheral adhesive region configured to adhere to the periphery of the reusable component. 15. The reusable component of claim 14, wherein the disposable connecting portion comprises a second peripheral adhesive region on a surface opposite the surface bearing the first peripheral adhesive region, wherein the second peripheral adhesive region is adapted to adhere to the patient’s chest. 16. The reusable component of claim 15, wherein the first and second peripheral adhesive regions are generally peripherally outside the region through which electric current flows from surfaces to supply current of the reusable component through the conductive layer of the connecting portion into the patient’s chest. 17. The reusable component of claim 14, wherein the conductive layer of the connecting portion comprises a solid conductive gel with adhesive properties sufficient to adhere the connecting portion to the patient’s chest. 18. The reusable component according to claim 15, further comprising a first and second coating film, which, before installing the connecting part in the reusable component, cover the first and second peripheral adhesive regions, respectively. 19. The reusable component according to claim 17, further comprising a first and second coating film, and before installing the connecting portion in the reusable component, the first coating film covers the first peripheral adhesive region and the second coating film covers the solid conductive gel. 20. The reusable component according to claim 1, which is combined with a sensor that provides an output signal from which information about the depth of chest compressions during cardiopulmonary resuscitation can be obtained. 21. The reusable component of claim 20, wherein the sensor comprises an accelerometer. 22. The reusable component according to claim 1, which is combined with a sensor that provides an output signal from which information about the force exerted on the chest during chest compressions during cardiopulmonary resuscitation can be obtained. 23. The reusable component according to claim 1, which is combined with a sensor that provides an output signal from which information about the compression rate of the chest during cardiopulmonary resuscitation can be obtained. 24. The reusable component of claim 1, wherein each of the plurality of current supply surfaces extends beyond the surface of the surrounding non-conductive element.

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