Patent Publication Number: US-2009227857-A1

Title: Biomedical electrode

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure generally relates to biomedical electrodes and, in particular, relates to a biomedical electrode capable of use in a garment. 
     2. Discussion of Related Art 
     Medical electrodes are used to transmit electrical signals between the body of a patient and external medical equipment, such as a monitoring, diagnostic, or stimulating device. 
     Biomedical electrodes are commonly used in therapeutic and diagnostic medical applications including, e.g., a variety of signal based rehabilitative procedures, electrocardiograph (ECG) or transcutaneous electrical nerve stimulation (TENS) procedures, maternal and/or fetal monitoring. Conventional biomedical electrodes are secured to the skin of a patient via a hydrogel and/or pressure sensitive adhesive. An electrical cable or lead wire is used to place the electrode in communication with an external electrical source. Various mechanisms for connecting a male/female terminal of the electrode to the complementary male/female terminal of the lead wire typically include “snap on” connectors, “pinch clip” arrangements, “twist on” couplings or magnetic couplings. A backside (i.e., a side opposite the hydrogel side) is typically provided with a non-conductive liner. 
     Accordingly, a need exists for an electrode including a first side supporting a hydrogel having a first adhesive quality or property for selective or removable fixation to the skin of a patient, and second side supporting a pressure sensitive adhesive (PSA) having a second adhesive quality or property for selective or removable fixation to a substrate, such as, for example, a garment or the like. 
     A further need exists for an electrode in which the adhesive properties of the PSA are greater than the adhesive properties of the hydrogel. 
     SUMMARY 
     A biomedical electrode assembly for attachment to a garment and to a subject includes a conductive member defining a first skin side relative to the subject and a second garment side, a conductive composition disposed on the first side of the conductive member for application to the subject, a pressure sensitive adhesive disposed on the second side of the conductive member or attached to a garment and an electrical lead in electrical communication with the conductive member. The pressure sensitive adhesive possesses an adhesiveness permitting repeated removal of the garment and the electrode assembly from the subject without substantially interfering with the bond between the pressure sensitive adhesive and the garment. 
     An electrode for selective attachment to at least one of a garment and a subject is provided. The electrode includes a conductive member defining a first side and a second side; a conductive composition disposed on the first side of the conductive member, wherein the conductive composition has a first adhesive strength; and a pressure sensitive adhesive disposed on the second side of the conductive member, wherein the pressure sensitive adhesive has a second adhesive strength that is greater than the adhesive strength of the conductive composition. The electrode is interposable between the garment and the subject such that the conductive composition is adhered to the subject and the pressure sensitive adhesive is adhered to the garment. In use, upon removal of the garment from the subject the electrode is removed only from the subject. 
     The electrode may further include an electrical lead in electrical communication with the conductive member. 
     The electrode may further include a reinforcement member disposed on the second side of the conductive member, wherein the reinforcement member supports the pressure sensitive adhesive. The reinforcement member may be a scrim. 
     The electrode may further include a release liner selectively, removably adhered to a surface of the conductive composition. The electrode may further include a release liner selectively, removably adhered to a surface of the pressure sensitive adhesive. 
     The pressure sensitive adhesive may be conductive or non-conductive. The pressure sensitive adhesive may be a hydrogel. 
     The electrode may further include a reinforcement member supporting the conductive composition. 
     The electrode may further include a reinforcement member supporting the conductive composition. The reinforcement member may be a scrim. 
     The electrode may further include a coating of silver provided on at least one of the first and second sides of the conductive member. 
     The electrode may further include a pig-tail style electrical lead. The electrical lead may be in electrical communication with at least one of the conductive member and the conductive composition. 
     The electrode may further include a snap-style electrical lead having a first end in electrical communication with at least one of the conductive member and the conductive composition. At least one of the conductive member and the pressure sensitive adhesive may define an aperture therein through which the second end of the electrical lead extends. 
     According to yet another aspect of the present disclosure, an electrode system for selective use with a subject is provided. The electrode system comprises a garment having a first side and a second side; and at least one electrode for selective attachment to the first side of the garment and to the subject. The electrode includes a conductive member defining a first side and a second side; a conductive composition disposed on the first side of the conductive member, wherein the conductive composition has a first adhesive strength; and a pressure sensitive adhesive disposed on the second side of the conductive member, wherein the pressure sensitive adhesive has a second adhesive strength that is greater than the adhesive strength of the conductive composition. In use, the electrode is interposable between the garment and the subject such that the conductive composition is adherable to the subject and the pressure sensitive adhesive is adherable to the garment. Following use of the system, upon removal of the garment from the subject the electrode is removed only from the subject. 
     Each electrode may further comprise an electrical lead in electrical communication with the conductive member. Each electrode may further comprise a reinforcement member disposed on the second side of the conductive member, wherein the reinforcement member supports the pressure sensitive adhesive. The reinforcement member may be a scrim. 
     Each electrode may further comprise a release liner selectively, removably adhered to a surface of the conductive composition and/or to a surface of the pressure sensitive adhesive. The pressure sensitive adhesive may be one of non-conductive and conductive. The pressure sensitive adhesive may be a hydrogel. The conductive composition may be a hydrogel. 
     Each electrode may further comprise a reinforcement member supporting the conductive composition. The reinforcement member may be a scrim. 
     Each electrode may further comprise a coating of silver provided on at least one of the first and second sides of the conductive member. 
     Each electrode may further comprise a pig-tail style electrical lead. The electrical lead may be in electrical communication with at least one of the conductive member and the conductive composition. 
     Each electrode may further comprise a snap-style electrical lead having a first end in electrical communication with at least one of the conductive member and the conductive composition. At least one of the conductive member and the pressure sensitive adhesive may define an aperture therein through which the second end of the electrical lead extends. 
     The garment may include at least an aperture formed therein for each electrode supported thereon, wherein the electrical lead is positioned within a respective aperture when the electrode is adhered to the garment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and, together with a general description of the disclosure given above, and the detailed description of the embodiment(s) given below, serve to explain the principles of the disclosure, wherein: 
         FIG. 1  is a schematic illustration of a garment for use in a medical, diagnostic, muscle stimulation, and/or therapeutic procedure, incorporating an electrode according to an embodiment of the present disclosure; 
         FIG. 2  is a cross-sectional, side elevational view of the electrode of  FIG. 1 ; 
         FIG. 3  is a perspective view of the electrode of  FIGS. 1 and 2 , shown with layers separated; 
         FIG. 4  is a cross-sectional, side elevational view of an electrode according to another embodiment of the present disclosure; and 
         FIG. 5  is a perspective view of the electrode of  FIG. 4 , shown with layers separated. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENT 
     The exemplary embodiments of the electrodes as a component of a reusable multi-electrode garment system disclosed herein are discussed in terms of use in performing a surgical therapeutic or diagnostic procedure in delivering or collecting electrical signals relative to a subject. Such procedures are inclusive of, but, not limited to, a variety of signal based rehabilitative procedures, muscle stimulation, electrocardiograph procedures, maternal and/or fetal monitoring. 
     In the discussion that follows, the term “subject” refers to a human patient or other animal. The term “clinician” refers to a doctor, nurse or other care provider and may include support personnel. 
     Referring now to the drawings wherein like components are designated by like reference numerals throughout the several views,  FIG. 1  illustrates a garment  20  incorporating an electrode  100  in accordance with the principles of the present disclosure. Garment  20  may be any suitable garment member and may be in the form of a vest, shirt, gown, belt, wrapping or the like. Garment  20  may be worn during an electrotherapeutic, muscle stimulation, or medical monitoring procedure, and is subsequently removed after completion of the procedure. Garment  20  is intended to be reused for subsequent procedures. Garment  20  may be fabricated from cloth, polyester or the like and is non-conductive in nature. As illustrated in  FIG. 1 , in one embodiment, garment  20  may incorporate a plurality of electrodes  100  which may be secured to a surface of garment  20  (e.g., within the interior of the garment  20 ) at predefined positions relative to the subject to provide the desired therapeutic or diagnostic effect, either prior to the donning of garment  20  or after donning of garment  20 . 
     Referring now to  FIGS. 2 and 3 , one embodiment of the electrodes of the present disclosure will be discussed in detail. Leadwire style biomedical electrode  100  is configured for selective attachment or affixation to garment  20  and for selective attachment or affixation to a subject  10 , e.g., to the skin of the subject  10 . Electrode  100  includes a conductive member  102  defining a first or skin side  102   a  relative to the subject  10  and a second or garment side  102   b , opposite first side  102   a . Conductive member  102  may be made from a conductive carbon, aluminum, tin or any other suitable material. As a further alternative, conductive member  102  may comprise a conductive plastic material. Conductive member  102  may include a coating of a silver composition  106  on either or both the skin and garment sides  102   a  and  102   b  thereof, respectively (only silver composition  106  disposed on garment side  102   b  is shown). 
     Electrode  100  further includes a conductive composition  104  disposed adjacent skin side  102   a  of the conductive member  102  for application/adhesion to or contact with the skin of subject  10 . Conductive composition  104  may be made from, for example, but not limited to, Promeon RG-63B hydrogel (TycoHealthcare Group LP d/b/a Covidien). As seen in  FIGS. 2 and 3 , in some embodiments, conductive composition  104  may incorporate a woven and/or nonwoven cloth or gauze material (e.g., scrim)  105  embedded therewithin or supporting the structure of the hydrogel. The conductive composition  104  may be any different commercially available conductive hydrogel. 
     In certain embodiments it may be desirable to provide a layer of adhesive (not shown) interposed between conductive member  102  and conductive composition  104 . 
     A first or skin side release liner  114  is releasably secured to conductive composition  104 . Release liner  114  can be made from a film or paper substrate having a release coating on one or both sides, such as, for example silicone. Release liner  114  protects and/or preserves conductive composition  104  (e.g., the hydrogel) and is removed prior to application on the skin of the subject  10 . Release liner  114  may be applied to conductive composition  104  after use of electrode  100  to preserve the conductive composition  104  for subsequent use. 
     In an embodiment, electrode  100  may further include a reinforcement member  108  disposed adjacent garment side  102   b  of conductive member  102 . In certain embodiments, reinforcement member  108  may overlie silver composition  106 . 
     Electrode  100  further includes a layer of pressure sensitive adhesive (PSA)  110  disposed adjacent garment side  102   b  of conductive member  102 . In an embodiment, pressure sensitive adhesive  110  overlies reinforcement member  108 . Reinforcement member  108  may be in the form of a scrim comprising a non-conductive fabric material. 
     Pressure sensitive adhesive  110  (PSA) is adapted and or selected to enable selective attachment of electrode  100  to garment  20 . The pressure sensitive adhesive  110  may be hot melt, acrylic, and/or rubber based adhesive. In one embodiment, pressure sensitive adhesive  110  is substantially a non-conductive acrylic adhesive. A second release liner  116  is positioned to cover pressure sensitive adhesive  110 . First and second release liners  114  and  116  may each be made from poly-coated paper having a thickness of about 0.127 millimeters (mm) (about 0.005 inches or 5 mils). 
     Electrode  100  further includes an electrical lead or lead wire  112 , e.g., a lead wire having a pig tail configuration that is in electrical communication with at least conductive member  102  and to power supply or monitor  150  (see  FIGS. 1 and 3 ). Electrical communication extends from lead wire  112  through the conductive member  102  (and silver composition  106 ) and through conductive composition  104  to subject  10 . 
     As described above, electrode  100  may be selectively attached to a garment  20  as a component of a reusable multi-electrode garment system. Specifically, a plurality of electrodes  100  may be selectively adhered to an interior of garment  20  at predetermined locations depending on the medical therapeutic or diagnostic procedure being performed on the subject  10 . In one embodiment, the adhesive characteristics or properties of pressure sensitive adhesive  110  relative to garment  20  is greater than the adhesive characteristics or properties of conductive composition  104  (e.g., the hydrogel) relative to the skin. Since the bond between conductive composition  104  and conductive member  102  is more aggressive than the bond between conductive composition  104  and patient skin, removal of garment  20  from the skin of subject  10  will cause removal of electrodes  100  from the skin of subject  10  prior to removal of electrodes  100  from garment  20 . As such, garment  20  and electrodes  100  may be removed simultaneously. 
     That is, conductive composition  104  possesses an adhesive strength permitting repeated removal of garment  20  and electrode  100  from the subject  10  without substantially interfering with the bond between pressure sensitive adhesive  110  and garment  20 . With this arrangement, garment  20  and associated electrodes  100  may be reused in subsequent procedures during a course of therapy or diagnostic applications. 
     Referring to  FIG. 2 , in one method of application, release liner  116 , adjacent garment side  102   b  of conductive member  102 , is removed from the pressure sensitive adhesive  110  and the respective electrode  100  is applied to garment  20  at a predefined location. Such predefined locations will correspond to a selected area of the body of the subject to be treated or monitored. A number of electrodes  100  may be mounted to garment  20  at various preselected locations. Thereafter, garment  20  is applied to the subject  10  with the electrodes  100  being positioned at the desired body locations. Release liner  114  adjacent conductive composition  104  may be removed either before or after garment  20  is donned. Pressure may be applied to the external surface of the garment  20  adjacent each electrode  100  to secure conductive composition  104  to the skin of subject  10 . A therapeutic or diagnostic treatment may then be performed. Upon completion of the procedure, garment  20  is removed. Due to the relatively greater bond existing between pressure sensitive adhesive  110  and conductive member  102 , as compared to between conductive composition  104  and conductive member  102 , electrodes  100  are peeled away from the skin of subject  10  upon removal of garment  20 . Release liner  114  may then be reapplied to the conductive composition  104  to preserve the conductive composition for a subsequent use. 
     Another method of application or use may include the steps of removing release liner  114  disposed on conductive composition  104  of each electrode  100  to be used, placing or affixing each electrode  100  on the skin of subject  10  at the desired location, removing release liner  116  disposed on pressure sensitive adhesive  110  of each electrode  100 , placing garment  20  on subject  10 , and applying pressure to garment  20  to affix garment  20  to pressure sensitive adhesive  110  of each electrode  100 . Following placement or fixation of garment  20  to electrodes  100 , electrical energy may be transmitted to electrodes  100 , as is commonly known, to perform electrotherapy, stimulation and the like. Following the transmission of the electrical energy to electrodes  100 , garment  20  may be removed from subject  10 . As garment  20  is removed from the patient, electrodes  100  are peeled away from or removed from the skin of subject  10 . In particular, due to the higher adhesive properties of pressure sensitive adhesive  110  as compared to conductive composition  104 , electrodes  100  will more readily peel away from the skin of subject  10  as compared to garment  20 . In other words, the aggressiveness of the adhesion of electrode  100  to garment  20 , via pressure sensitive adhesive  110 , is greater than the aggressiveness of the adhesion of electrode  100  to the skin of subject  10 , via conductive composition  104 . 
     Following removal of garment  20 , original release liners  114  or replacement release liners (not shown) may be applied to conductive composition  104  to thereby protect conductive composition  104 . The release liners  114  may remain in place until the next course of treatment for the patient. In this manner, garment  20  is now provided with electrodes  100  which are properly located (or located at the same position) on the individual subject  10  for each subsequent course of treatment. 
     In the event that one electrode  100  is defective, said defective electrode  100  may be removed from garment  20  and replaced with a new electrode  100 . In this manner, the entire garment does not have to be replaced. 
     Turning now to  FIGS. 4 and 5 , there is illustrated an electrode  200  according to an alternate embodiment of the present disclosure. More particularly, electrode  200  is configured for attachment to garment  20  and to subject  10  and includes a conductive member  202  defining first side  202   a  and second side  202   b . Conductive member  202  has at least one aperture  202   c  formed therein that is in communication with a second side  20   a  of garment  20 . A conductive composition  204  is disposed on a first or skin side of electrode  200 . A connector component  240  is disposed against conductive composition  204  and may, in certain embodiments (as seen in  FIG. 4 ), be embedded within conductive composition  204 . Connector component  240  may be conductive and may define a male terminal or male pin  242  as shown. 
     The electrode may further include a coating of silver provided on at least one of the first and second sides of the conductive member. In certain embodiments, electrode  200  may include a layer of silver composition  206  overlying second side  202   b  of conductive member  202 , on a side opposite conductive composition  204 . 
     As seen in  FIG. 4 , electrode  200  may be provided without a reinforcement member, or as seen in  FIG. 5 , electrode  200  may be provided with a reinforcement member  208  overlying silver composition  206 . As seen in  FIG. 4 , a non-conductive pressure sensitive adhesive  210  may be disposed on silver composition  206  of electrode  200 , or as seen in  FIG. 5 , non-conductive pressure sensitive adhesive  210  may be disposed on reinforcement member  208 . 
     Pressure sensitive adhesive  210  secures electrode  200  relative to the garment  20  in a similar manner to that described in the electrode embodiment of  FIGS. 2 and 3  and permits repeated removal and reuse without substantially affecting the bond created between pressure sensitive adhesive  210  and garment  20  (see  FIG. 2 ). As can be appreciated from the foregoing description, a plurality of electrodes  200  may be attached to the interior of garment  20  at desired locations depending on the procedure contemplated. 
     As seen in  FIGS. 4 and 5 , in some embodiments, conductive composition  204  may incorporate a woven and/or nonwoven cloth or gauze material (e.g., scrim)  205  embedded therewithin or supporting the structure of the conductive composition (e.g., hydrogel). 
     Each of silver composition  206  and pressure sensitive adhesive  210 , and optionally reinforcement member  208 , may be provided with a respective aperture  206   c ,  210   c , and  208   c  that is in general alignment with aperture  202   c  of conductive member  202  for accommodating pin  242 . 
     A second connector component  244  may be at least partially positioned within aperture  210   c  of pressure sensitive adhesive  210  and mechanically couples with connector component  240 . In an alternate embodiment, if connector component  240  is non-conductive, an electrical interface may be established via second connector component  244  and conductive member  202 . Second connector component  244  is thus in electrical contact with conductive member  202  via first connector component  240 . Second connector component  244  is also electrically conductive. In one embodiment, second connector component  244  includes a female receptacle  246  which receives male terminal or pin  242  of first connector component  240  in a snap-type or threaded relation therewith to couple components  240 ,  244  with one another. Conductive member  202  may be interposed between first and second connector components  240 ,  244 . Other arrangements for coupling first and second connector components  240 ,  244  are also envisioned including “pinch clip” arrangements, “twist on” couplings or the like. It is also envisioned that second connector component  244  may include the male pin or terminal and first connector component  240  may include the associated female receptacle to receive the male terminal to couple the components. 
     First and second connector components  240  and  244  may be used to electrically connect electrode  200  to a terminal of garment  20 . First and second connector components  240 ,  244  may be in the form of a suitable snap style connector adapted to mechanically and electrically couple with a complementary female terminal (not shown) of garment  20 . 
     Electrode  200  may be provided with first and second release liners  214 ,  216  to cover conductive composition  204  and pressure sensitive adhesive  210 , respectively, in a similar manner to release liners  114 ,  116  discussed hereinabove. 
     Although the illustrative embodiments of the present disclosure have been described herein with reference to the accompanying drawings, it is to be understood that the disclosure is not limited to those precise embodiments, and that various other changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the disclosure.