U.S. patent number 3,640,270 [Application Number 05/059,283] was granted by the patent office on 1972-02-08 for electric contactor with venturi-suction means for organic tissue.
This patent grant is currently assigned to Ingeborg Niess, Elektromedizinische. Invention is credited to Heiner Hoffmann.
United States Patent |
3,640,270 |
Hoffmann |
February 8, 1972 |
ELECTRIC CONTACTOR WITH VENTURI-SUCTION MEANS FOR ORGANIC
TISSUE
Abstract
A contactor for diagnostic or therapeutic use on human or animal
tissue comprises a suction cup of elastomeric material containing
an electrolyte-impregnated sponge near the mouth of the cup
supported on an electrode plate from which a conductor extends
insulatedly outwardly inside a tube leading to a source of air
under pressure. This tube, traversing the cup inwardly of the
electrode plate, forms a Venturi nozzle for aspirating air from the
interior of the cup and terminates in an outlet which opens into
the atmosphere for dispersing entrained liquid.
Inventors: |
Hoffmann; Heiner (Herrlingen,
DT) |
Assignee: |
Ingeborg Niess,
Elektromedizinische (Herrlingen, DT)
|
Family
ID: |
5741815 |
Appl.
No.: |
05/059,283 |
Filed: |
July 29, 1970 |
Foreign Application Priority Data
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|
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|
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Aug 2, 1969 [DT] |
|
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P 19 39 523.4 |
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Current U.S.
Class: |
600/387;
600/397 |
Current CPC
Class: |
A61N
1/0408 (20130101); A61B 5/252 (20210101); A61N
1/26 (20130101); A61N 1/0472 (20130101) |
Current International
Class: |
A61B
5/0408 (20060101); A61N 1/26 (20060101); A61N
1/30 (20060101); A61N 1/04 (20060101); A61N
1/20 (20060101); A61b 005/04 () |
Field of
Search: |
;128/2.6E,2.6R,2.1E,2.1R,404,410,411,417,418,DIG.4 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Kamm; William E.
Claims
I claim:
1. A contactor for establishing electric communication with organic
tissue, comprising a generally cup-shaped housing consisting at
least partly of conductive material, said housing having a mouth
bounded by a tissue-engaging rim; storage means in said housing
accessible through said mouth for maintaining a supply of liquid
electrolyte in contact with the conductive part of said housing;
conduit means leading from a source of high-pressure gas to the
atmosphere, said conduit means forming a Venturi nozzle and being
provided with a branch leading from said nozzle to the interior of
said housing for creating in the latter a partial vacuum to hold
said rim in contact with tissue engaged thereby while dispersing
entrained liquid from said storage means into the open air, and
conductor means extending outwardly from said conductive part for
connection to an external circuit.
2. A contactor as defined in claim 1 wherein said conduit means
comprises a tube rigid with said housing.
3. A contactor as defined in claim 2 wherein said conductive part
comprises an electrode plate in said housing spaced inwardly from
said rim, said plate having a hole forming part of said branch.
4. A contactor as defined in claim 3 wherein said tube is metallic
and contacts said electrode plate on the side thereof opposite said
mouth.
5. A contactor as defined in claim 4 wherein said conduit means
includes a metallic nipple integral with said tube and said
conductor means comprises a lead tied to said nipple, said conduit
means further including a hose fitted around said nipple and
enveloping at least part of said lead.
6. A contactor as defined in claim 4 wherein said housing comprises
an elastomeric shell surrounding said electrode plate and said
tube.
7. A contactor as defined in claim 3 wherein said storage means
comprises a sponge carried on a surface of said electrode plate
confronting said rim.
Description
The present invention relates to a contactor for establishing
electric communication with organic tissue, such as the skin of a
human or animal body, for diagnostic or therapeutic purposes. More
particularly, it relates to a contactor utilizing a partial vacuum
for holding an electrode onto the skin or other body tissue, in the
presence of a liquid electrolyte to facilitate the transition of
ions between the electrode and the tissue.
In simple cases a contactor of this type can be equipped with a
hand pump, such as a rubber ball, to create the necessary pressure
differential. In view of an unavoidable leakage between the tissue
and the rim of the cup-shaped electrode housing, however, such a
partial vacuum cannot be long maintained so that the contact time
between the electrode and the tissue is limited. For prolonged
contact, therefore, a suction pump must be used whereby the
pressure differential can be maintained indefinitely.
The application of such suction to the interior of the cup tends to
extract some of the electrolyte present therein with formation of
condutive bridges between the electrode and the normally grounded
pump housing, these bridges shunting the usually high-ohmic input
indepedance of a voltage source connected between that electrode
and ground. Such shunts are particularly objectionable in the case
of diagnostic instruments whose readings may be falsified by the
resulting leakage current. The use of liquid separators or traps in
the suction line, in order to break up these electrolytic bridges,
is cumbersome and expensive, especially where a single pump serves
several contactors of the aforedescribed type which must remain
electrically insulated not only from the pump housing but also from
one another. The maintenance of a specified pressure differential
with the aid of a suction pump operating through interposed liquid
separators is also difficult.
It is, therefore, the object of my present invention to provide a
contactor of the general character referred to, serving as an
attachment for therapeutic or diagnostic apparatus including a
source of electric current, in which the aforestated drawbacks are
avoided.
This object is realized, pursuant to the invention, by the
substitution of a source of high-pressure gas for the conventional
suction pump, the gas traversing a conduit with a Venturi-type
nozzle to create an underpressure communicated to the interior of
the suction cup via a branch from that conduit. Any liquid
aspirated through that branch and entrained by the gas passing
through the main conduit is dispersed into the open air through an
outlet discharging freely into the atmosphere, thereby positively
preventing the formation of any electrolyte bridge.
Advantageously, according to a more specific feature of my
invention, the conduit is a preferably metallic tube rigid with the
cup-shaped housing. In this case a branch leading from the Venturi
nozzle to the interior of the cup may be a short passage formed by
a hole in an electrode plate within a housing and an adjoining hole
in the tube wall. The metallic tube, together with a metallic
nipple extending outwardly therefrom for connection to an air hose,
may then form part of an electric conductor connecting the
electrode plate to the external power supply, this conductor
advantageously including a wire extending from the nipple toward
the power supply within the gas line itself.
Since the only medium traveling between the pump and the suction
cup is air or some other dry and nonconductive gas, the insertion
of liquid separators in that path becomes unnecessary.
The invention will be described in greater detail hereinafter with
reference to the accompanying drawing in which:
FIG. 1 is a sectional side view of a contactor embodying the
invention;
FIG. 2 is a cross-sectional view taken on the line II--II of FIG.
1: and
FIG. 3 is a top view partly in section on the line III--III of FIG.
1.
The device shown in the drawing, attached to a diagnostic or
therapeutic apparatus not further illustrated, comprises a housing
1 of rubber or other elastomeric material formed with a mouth 3
which is bounded by an elastically deformable rim 2. The lower part
of this housing as viewed in FIGS. 1 and 2 has the shape of an
inverted cup whose bottom includes an electrode plate 5 embedded in
the elastomeric material. Also embedded in that material, but
projecting downwardly toward the mouth 3, is a sponge 4 permeated
by liquid electrolyte; upon firm application of the rim 2 to the
skin of a human or animal body, the sponge 4 contacts the skin and
establishes an ionic path between the latter and the electrode 5
upon which it bears. This electrode, in turn, is in contact with a
metal tube 6 overlying same, tube 6 having a bore 8 with an outlet
7 opening into the atmosphere from the body of elastomeric material
in which it is embedded. A constriction 9 near the opposite end of
the tube receives a nozzle-shaped tip of a restrictive insert 10
held in place by a metallic nipple 11 threaded at 17 (FIG. 3) into
the inlet end of the tube. The Venturi effect created at the
junction of nozzle 10 with the restricted bore portion 9 of tube 6
generates suction which is communicated to the interior of the
housing above mouth 3 by way of a passage including a lateral hole
16 in tube 6, a hole 15 in plate 5 aligned therewith and a
corresponding hole in the layer of elastomeric material underlying
the electrode plate. The length of the wider part of bore 8 is
designed to attenuate the noise of the gas rushing through the tube
6. A wire 12, bearing insulation 13, extends from the free end of
nipple 11 to a source of operating voltage, not shown, by way of a
microammeter or equivalent means for testing the bioelectric
resistance of the body if the apparatus is to be used for
diagnostic purposes. A preferably flexible and electrically
nonconductive hose 14 is fitted onto nipple 11 (omitted in FIG. 3)
and extends to the discharge part of a compressor, storage tank or
other source of gas (e.g. air) under a sufficient pressure to
generate the desired suction within the cup-shaped lower part of
housing 1. The gas pressure may be adjusted to a desired level by
conventional regulating means likewise not illustrated.
Once the necessary suction has been created and the rim 2 of the
cup is firmly seated on the skin of the body under test, the volume
of air traversing the passage 15, 16 will be just sufficient to
balance leakage losses. A small amount of electrolyte entrained
with this air by the main flow through the tube 6 will be dispersed
into the atmosphere at outlet 7 without creating any low-resistance
current bridges between ground and the conductive housing part
represented by electrode 5.
In practice, the rate of gas flow through the Venturi nozzle 9, 10
needed to maintain the desired subatmospheric pressure will be
quite low. The orifice of insert 10 may have a diameter of about
0.25 mm.
It will be appreciated that parts of housing 1, other than
electrode plate 5, could also be made of metal or other conductive
material and that the sponge 4 is merely representative of a
variety of means (such as, for example, reservoirs with restricted
outlets) for storing a liquid electrolyte within the cup housing to
provide the desired ionic contact.
* * * * *