U.S. patent number RE32,724 [Application Number 06/786,710] was granted by the patent office on 1988-08-02 for reusable medical electrode having disposable electrolyte carrier.
This patent grant is currently assigned to American Hospital Supply Corporation. Invention is credited to James V. Cartmell.
United States Patent |
RE32,724 |
Cartmell |
August 2, 1988 |
**Please see images for:
( Certificate of Correction ) ** |
Reusable medical electrode having disposable electrolyte
carrier
Abstract
A medical electrode particularly suited for use as an EEG
electrode comprises initially separated electrode conductor and
electrolyte carrier components which are united prior to use of the
electrode. The electrolyte carrier component comprises a disposable
adhesive patch adhered to a disposable sponge member soaked with an
electrolyte. The electrode conductor component comprises a reusable
conductor ring having an affixed lead wire terminating with a
plug-in device for effecting attachment to a monitoring instrument.
Prior to use the electrolyte carrier components are stored in one
or more evaporation resistant tray devices.
Inventors: |
Cartmell; James V. (Dayton,
OH) |
Assignee: |
American Hospital Supply
Corporation (Evanston, IL)
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Family
ID: |
26728470 |
Appl.
No.: |
06/786,710 |
Filed: |
October 11, 1985 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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590182 |
Mar 16, 1984 |
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50626 |
Jun 21, 1979 |
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Reissue of: |
215277 |
Dec 11, 1980 |
04319579 |
Mar 16, 1982 |
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Current U.S.
Class: |
600/392; 600/383;
607/153 |
Current CPC
Class: |
A61B
5/274 (20210101); A61B 2562/0217 (20170801) |
Current International
Class: |
A61B
5/0408 (20060101); A61B 5/0416 (20060101); A61B
005/04 () |
Field of
Search: |
;128/639-641,644,783,791-793,798,802,803,731 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Cohen; Lee S.
Attorney, Agent or Firm: Dybvig & Dybvig
Parent Case Text
.Iadd.This is a continuation of co-pending application Ser. No.
590,182, filed Mar. 16, 1984, now abandoned. .Iaddend.
This is a continuation, of application Ser. No. 050,626, filed June
21, 1979 for REUSABLE MEDICAL ELECTRODE HAVING DISPOSABLE
ELECTROLYTE MEANS now abandoned.
Claims
Having thus described my invention, I claim:
1. A medical electrode comprising a disposable portion and a
reusable portion, said disposable portion comprising a shaped
absorbent body soaked with an electrolyte and a pliant sheet member
having an adhesive layer on one side thereof, said adhesive layer
adhering an end of said body to said one side of said sheet member,
said body protruding outwardly from said adhesive layer, said
reusable portion comprising terminal means for transmitting
electrical signals and readily separable from said disposable
portion, said terminal means having an inside wall embracing and
substantially surrounding said shaped body.
2. The medical electrode of claim 1 wherein said shaped body is a
cylindrical body and said end adhered to said adhesive layer is
disposed at one end of said cylindrical body.
3. The medical electrode of claim 2 wherein said terminal means
uninterruptedly surrounds said cylindrical body.
4. The medical electrode of claim 3 wherein said terminal means
comprises a ring portion having an outward projection from said
adhesive layer of said sheet member which is less than the outward
protrusion of said shaped body from such adhesive layer.
5. The medical electrode of claim 1 wherein said sheet member is an
oblong sheet member.
6. The medical electrode of claim 5 wherein said oblong sheet
member is elliptically shaped.
7. The medical electrode of claim 1 wherein said sheet member is a
vinyl plastic sheet member.
8. The medical electrode of claim 1 wherein said inside wall is a
metal wall.
9. The medical electrode of claim 8 wherein said metal wall is
silver metal.
10. The medical electrode of claim 8 wherein the metal of said wall
is chloridized.
11. The medical electrode of claim 1 wherein said sheet member has
an edge margin surrounding said protruding body and spaced from
said protruding body.
12. The medical electrode of claim 11 wherein a portion of said
adhesive layer disposed between said shaped body and said edge
margin adheres to a portion of said terminal means.
13. The medical electrode of claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
11 or 12 wherein said sheet member is moisture impervious.
14. The medical electrode of claim 13 wherein said sheet member is
imperforate.
15. In the method of preparing a patient for monitoring electrical
signals available at the body of the patient the steps comprising
connecting a distal end portion of a lead wire to a monitoring
instrument, connecting a proximal end portion of said lead wire to
electrode terminal means for transmitting electrical signals,
adhesively attaching a shaped absorbent body to an adhesive coating
on a patch member, soaking said shaped body with an electrolyte,
inserting said electrolyte soaked body in said electrode terminal
means, and placing said soaked body in contact with the body of the
patient by adhesively affixing the adhesive coating on said patch
member over said terminal means to the patient.
16. The method of claim 15 wherein the placement of said soaked
body in contact with the body of the patient comprises the
additional steps of parting the hair of the patient, positioning a
portion of the lead wire connected to said electrode terminal means
along the part formed by parting the patient's hair, and pressing
said adhesive patch member over said lead wire and onto the
patient's hair to secure said electrolyte soaked body and said
electrode terminal means to the body of the patient. .Iadd.
17. In combination:
a one-piece, imperforate and moisture impervious pliant plastic
sheet;
an adhesive layer completely coating one side of said sheet;
an aggregate comprising an electrolyte and a shaped body for
containing said electrolyte, said body having a planar end surface
facing toward said sheet and said body being adhered to a part of
said adhesive layer which is spaced from the margin of said sheet
by engagement of the entirety of said planar surface with said
part; and
relatively moisture impevious means providing a support having a
supporting surface, said supporting surface being adhesively
engaged to peripheral portions of said adhesive layer surrounding
said part,
said sheet and said adhesive layer thereby cooperating with said
support-providing means to seal said aggregate from the atmosphere
surrounding said support-providing means. .Iaddend. .Iadd.
18. In a medical electrode of the type comprising a disposable
portion and a reusable portion;
the improvement wherein said reusable portion comprises metal
terminal means connected to an insulated lead means for attachment
to peripheral equipment; and
said disposable portion comprises:
a. a one-piece, imperforate and moisture impervious pliant plastic
sheet;
b. an adhesive layer completely coating one side of said sheet;
and
c. an aggregate comprising an electrolyte and a shaped body for
containing said electrolyte, said body having a planar end surface
facing toward said sheet and said body being adhered to a part of
said adhesive layer which is spaced from the margin of said sheet
by engagement of the entirety of said planar surface with said
part;
said reusable portion being so constructed that said terminal means
may be located between said adhesive layer and the skin of a
patient in engagement with said aggregate with a portion of said
lead means located between said adhesive layer and the skin of the
patient. .Iaddend. .Iadd.
19. Apparatus for assembling a medical electrode on the skin of a
patient comprising:
A. means providing a relatively moisture impervious support having
a supporting surface;
B. a disposable assembly removably supported by said means
providing a support comprising:
a. a one-piece, imperforate and moisture impervious pliant plastic
sheet;
b. an adhesive layer completely coating one side on said sheet;
c. means forming a shaped body adhered to a part of said adhesive
layer separated from the margin thereof for containing an
electrolyte, peripheral portions of said adhesive layer surrounding
said electrolyte containing means being engaged with said
supporting surface so that said sheet and said adhesive layer
cooperate with said support providing means to seal said
electrolyte containing means from the atmosphere surrounding said
support providing means; and
C. a reusable portion comprising an insulated lead wire having a
metallic terminal which is uninsulated so that said disposable
assembly may be removed from said support providing means and
placed over the skin of a patient with said terminal covered by
said sheet and also engaging said electrolyte containing means to
form an electrode held to the skin of a patient by said adhesive
layer. .Iaddend. .Iadd.20. A method of assembling a medical
electrode onto the skin of a patient comprising the steps of:
providing a disposable assembly comprising means forming an
imperforate pliant sheet of moisture impervious plastic having an
adhesive layer completely coating one side thereof and further
comprising means forming a shaped body adhered to a part of said
adhesive layer separated from the margin thereof for containing an
electrolyte;
mounting said disposable assembly onto means providing a relatively
moisture impervious support with said disposable assembly removably
attached to said support providing means by a marginal portion of
said adhesive layer surrounding said part of said adhesive
layer;
removing said disposable assembly from said support providing means
when the medical electrode is to be assembled onto the skin of a
patient; and
adhering said disposable assembly in contact with the skin of the
patient by engaging said marginal portion of said adhesive layer to
the skin with an uninsulated terminal of an insulated layer wire
engaging said electrolyte containing means and held between said
sheet forming means and the patient's skin. .Iaddend.
Description
BRIEF SUMMARY OF THE INVENTION
In the present invention, shaped initially dry absorbent bodies or
sponges are adhered centrally to adhesive patches each sized to
ultimately adhere an assembled electrode to the body of a subject.
The sponges are then soaked with an adequate supply of electrolyte
and the resulting electrolyte carrier components are placed for
storage in wells of a storage tray, utilizing exposed adhesive on
the adhesive patches for sealing attachment of the electrolyte
carriers to the storage tray.
Electrode conductor components which are ultimately to be assembled
to the aforementioned electrolyte carrier components comprise
prechlorided, or otherwise suitably treated conductor ring
portions, sized to surround the aforementioned electrolyte loaded
sponges, said conductor ring portions having affixed lead wires
which terminate distally with plug-in terminals suitable for
attachment to monitoring equipment. Subsequent assembly of the
electrodes is effected by sliding the electrolyte loaded sponges of
the electrolyte carrier components each into a separate conductor
ring portion already attached to the monitoring equipment and then
applying the adhesive patches of the assembled components to the
body of a subject, the dimensions of the assembled components being
such that adhesive attachment to the body of the subject compresses
the electrolyte loaded sponge and, as such compression occurs,
securely affixes the electrolyte sponge, the conductor ring portion
and the lead wire emanating from the conductor ring portion to the
body of the subject.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view with a portion broken away
illustrating a tray supporting thereon a plurality of disposable
electrolyte carrier components.
FIG. 2 is a greatly enlarged fragmentary perspective view
illustrating one of the disposable electrolyte carrier components
being removed from the tray.
FIG. 3 is a fragmentary perspective view schematically illustrating
the manner in which a disposable electrolyte carrier component is
attached to a reusable electrode component in preparation for
affixation of an assembled electrode to a subject.
FIG. 4 is a greatly enlarged fragmentary perspective view
illustrating the reusable electrode component in solid lines before
assembly to the disposable component and in broken lines after
assembly to the disposable component.
FIG. 5 is a fragmentary perspective illustration of an assembled
electrode applied to the unshaven scalp of a subject.
DETAILED DESCRIPTION
Referring first to the disposable component of the electrode, FIGS.
1 and 2 illustrate a molded and generally planar supporting tray 10
having a plurality of recessed wells or cups 12, the wells
preferably being arranged in an orderly array such as the two
parallel rows illustrated in FIG. 1 with the wells in one row being
offset, or staggered, with respect to the wells in the other row.
Adhered to the upper surface of the tray 10 are a plurality of
pliant plastic patches 14, each having an adhesive coating 16 on
the side thereof which is contacted to the tray 10.
The patches 14 are preferably of an oblong or elliptical shape and
each has .Iadd.an electrolyte aggregate comprising .Iaddend.a
cylindrically shaped electrolyte loaded absorbent body 18 adhered
at one end thereof to a centrally disposed area of the adhesive
coating 16 which otherwise surrounds the adhered absorbent body 18.
The cylindrically shaped bodies are preferably adhered to the
patches 14 when in a dry state productive of good adhesion and are
thereafter generously soaked with a liquid electrolyte 18a.
Each of the patches 14 has a lifting tab 20 adhered to the adhesive
coating 16 where it projects outside the edge margin of the patch
14 for easy finger lifting of the lifting tab 20 and therewith easy
peeling of the associated patch 14 from the upper surface of the
tray 10. The staggered arrangement of the wells 12 allows ample
clearance between the patches 14 for finger engagement as
described.
It will be noted that the electrolyte soaked bodies 18 have
diameters which are small in relation to the inside diameters of
the wells 12, such that when the patches 14 are peeled away from
the tray 10 none of the electrolyte contained in the absorbent
bodies 18 will be transferred to the walls of the wells 12. Thus
the bodies 18 may be prefilled each with a measured quantity of
electrolyte and since the bodies 18 are sized so as not to
physically contact the tray 10, none of the measured quantity of
electrolyte will be lost by transfer to the surfaces which form the
wells 12.
The tray 10, which may be sized to support some 23 of the patches
14, is preferably molded or otherwise formed of a relatively
moisture impermeable plastic, such as polyethylene. The patches 14
are preferably formed of a relatively limp moisture impervious
plastic, such as a vinyl plastic. The adhesive comprising the
adhesive surface 16 is preferably a pressure sensitive medical
adhesive of which a number of types are commercially available.
With the adhesive surfaces 16 securely affixing the patches 14 of
the upper surface of the tray 10, the wells 12 are sealed against
the entry of ambient atmosphere and the electrolyte soaked bodies
or sponges 18 protected against evaporation of the electrolyte for
long periods of time.
The formed absorbent bodies 18 are conveniently punched out of a
sheet of a foamed plastic, such as a polyurethane plastic of the
open cell type. However, other absorbent bodies, such as fibrous
gauzes, sponges and the like may be utilized in lieu of foamed
plastics.
The reusable portion of the electrode, which is best illustrated in
FIG. 4, comprises a stamped metal terminal 32 for transmitting
electrical signal of the type comprising a circular ring 34 having
a radially disposed integrally formed lug extending outwardly from
the ring. The outwardly extending terminal lug does not fully
appear in the drawings because covered by a shrink-fitted plastic
sleeve 30. Before being covered by the sleeve 30 the lug is
attached by solder, or the like, not shown, to an electrical
conductor 27 covered by an insulating sheath so as to form an
insulated wire 28. It can be noted that the sleeve 30 is of such a
length that approximately one-half of the sleeve covers the lug
emanating from the terminal 32 and the remainder of the sleeve
snugly surrounds the wire 28. As those skilled in the art will
appreciate, the solder connection between the conductor 27 and the
terminal lug may be overpainted with a moisture impervious plastic,
not shown, so as to assure that no electrolyte from the body 18
will have access to the solder or to the conductor 27.
The terminal 32 is preferably a very high quality silver, such as
99.9% silver, and the terminal lug extending through the sleeve 30,
being one piece with the terminal ring 34, would of course comprise
the same high quality silver. The outer surfaces of the terminal
ring 34 are preferably chlorided by contacting the ring 34 with any
suitable chloriding solution. This chloridization preferably occurs
before the sleeve 30 is shrunk into position so as to assure that
no part of the terminal ring 34, which is later permitted to
contact electrolyte as will be explained, has not been first
chlorided. The sleeve 30 is preferably any moisture impervious heat
shrinkable plastic, such as tetrafluoroethylene (Teflon).
The end of the conductor 27 which has been soldered to the terminal
lug covered by the sleeve 30 may be referred to as the proximal end
of the wire 28. The opposite or distal end of the wire 28 is
soldered, or otherwise connected, to a conventional bayonet plug 26
which, as will be described, is used for connecting the assembled
electrode to an external signal monitoring device, such as an
electroencephalograph recording device.
As apparent in FIG. 4, the disposable and the reusable electrode
components are assembled together by passing the chlorided ring 34
over any one of the electrolyte soaked bodies 18, such bodies
having been sized with a diameter only slightly less than the
inside diameter of the ring 34. FIG. 4 illustrates the ring 34 and
associated wire 28 before assembly to the disposable component in
solid lines and shows by broken lines the manner in which the ring
34 fits over the electrolyte soaked body 18 so as to become adhered
to the adhesive layer 16 present on the patch 14 and surrounding
the body 18.
FIG. 3 illustrates a patient P lying adjacent an EEG terminal board
22 in preparation for an EEG examination. The terminal board 22 is
provided with a number of bayonet receptacles 24. Plugged into a
number of the receptacles 24 are bayonet plugs 26 from which dangle
insulated wires 28. The insulated wires may be, for example, 4 ft.
in length.
EEG examinations typically involve the mounting of a large number
of recording electrodes to the scalp and sometimes other parts of
the body of the patient and the simultaneous recording of a
plurality of traces derived from combinations of the mounted
electrodes. Individual traces, each of which may be derived from a
combination of two or more electrodes, are simultaneously recorded
side-by-side on an EEG chart. Any one of the side-by-side traces is
sometimes referred to as a channel and a display of a plurality of
side-by-side traces or channels is typically referred to as a
montage.
Each single recording of a trace or channel involves a comparison
of electrodes attached to different portions of the patient's scalp
or body, with the resultant trace being the difference in the
voltages derived from the patient's body by means of the
electrodes. A trace produced by a large number of electrodes all
referenced to a single other electrode is sometimes referred to as
a monopolar trace or channel. A trace in which one electrode is
referenced to a single other electrode is typically referred to as
a bipolar trace or channel.
The number and location of the wires 28 and receptacles 24 employed
during any monitoring procedure varies depending upon the number of
traces or channels forming the montage desired to be accomplished.
As a convenience, wires 28 may be color coded or otherwise marked
to simplify wire selection for montage formation.
As appears in FIG. 3 an attendant has selected a given one of the
wires 28 for passage of its terminal ring portion 34 onto an
electrolyte soaked body 18 protruding from an adhesive patch 14.
Then, as shown in FIG. 5, the assembled electrode is applied to the
patient's scalp after separating the patient's hair so as to form a
part 36 which exposes a portion of the patient's skin surface 38.
The direction in which the part 36 extends will obviously depend on
the direction in which the patient's hair has been parted and the
location of the electrode along such part in turn depends upon the
nature of the montage sought to be produced.
In general, the illustrated elliptical shape for the patches 14 is
preferred. Thus the direction in which a particular part of the
patient's hair extends is subject to the control of the attendant
who can so arrange the hair partings that the major axes of the
elliptical patches extend along the hair partings so as to maximize
adhesive contact with the skin exposed by such partings without, at
the same time, generating unmanageable overlaps between patches
required to be mounted in close proximity.
As apparent in FIG. 5 it is also desirable that the wire 28 also
extend along the part 36 so that a minimum of the patient's hair
lies under the wire 28, with the consequence that the wire position
is firmly anchored and tensions developed along the length of the
wires will have a minimal affect upon the electrode position.
It can be appreciated that as the patch 14 is pressed against the
patient's scalp, the electrolyte loaded body 18 will be compressed
in that the body 18 is longer than the ring portion 34 is thick.
This compression generously wets with electrolyte the patient's
scalp under the patch 14 and, at the same time, expands the body 18
against the inside wall of the ring 34 so as to effect a secure
attachment between the body 18 and the ring 34. Inasmuch as the
rings 34 will have been prechlorided, or otherwise treated, it can
be appreciated that assembled electrodes are ready immediately for
signal monitoring.
In the foregoing description, the patches 14 with their
accompanying electrolyte loaded bodies 18 have been characterized
as disposable electrolyte components, or carriers. Thus upon
completion of the monitoring desired to be accomplished, the
patches 14 may be readily removed from the patient's scalp with the
aid of a solvent in conventional fashion and then the patches 14,
together with the electrolyte loaded bodies 18, discarded. The lead
wire 28 together with the prechlorided terminal ring 34 may then be
cleaned under suitably aseptic conditions and reused with a clean
and previously unused disposable electrolyte carrier. The number of
times the reusable electrode part may be reused will, of course,
depend upon the permanency of the chloriding process or other
electrode preparation procedure and the abrasiveness of the aseptic
cleaning process used between successive monitoring operations.
Those skilled in the art will appreciate, of course, that
chloriding is frequently the most desirable preparation for an
electrode metal such as silver which is relatively noble and that
when lesser electrode metals, such as tin or copper, are to be
employed in the practice of the present invention, chloriding may
be less desirable.
Although the preferred embodiment of this invention has been
described, it will be understood that various changes may be made
within the scope of the appended claims. .Iadd.As used herein, the
term "aggregate" means an assemblage or group of distinct
particulars massed together.
* * * * *