U.S. patent number 3,760,332 [Application Number 05/233,069] was granted by the patent office on 1973-09-18 for pacer connector.
Invention is credited to Barouh V. Berkovits, Pieter J. Denouter, Edward L. Lewis.
United States Patent |
3,760,332 |
Berkovits , et al. |
September 18, 1973 |
PACER CONNECTOR
Abstract
A connector arrangement for an implantable pacer which allows an
electrode plug to be inserted into a pacer receptacle without the
need for set screws or the use of protective medical adhesives. The
connector includes a pair of spring-loaded collets each within its
own retainer for making reliable electrical connections to two plug
pins. A gasket is provided for each collet to prevent body fluids
from gaining access to it.
Inventors: |
Berkovits; Barouh V. (Newton
Highlands, MA), Denouter; Pieter J. (Marlboro, MA),
Lewis; Edward L. (Sharon, MA) |
Family
ID: |
22875760 |
Appl.
No.: |
05/233,069 |
Filed: |
March 9, 1972 |
Current U.S.
Class: |
439/381; 607/37;
439/281; 439/347; 439/843; 439/948 |
Current CPC
Class: |
H01R
13/5224 (20130101); A61N 1/3752 (20130101); Y10S
439/948 (20130101) |
Current International
Class: |
A61N
1/375 (20060101); A61N 1/372 (20060101); H01R
13/52 (20060101); H01r 013/62 () |
Field of
Search: |
;339/60,65,66,75,94
;128/418,419P |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: McGlynn; Joseph H.
Claims
What we claim is:
1. A pacer connector arrangement for connecting an electrode plug
having two pins extending from projections thereon to a pacer
circuit comprising a pair of connector assemblies, each for
coupling signals between the pacer circuit and a respective plug
pin, each of said connector assemblies having a multi-pronged
collet embedded in the pacer, each prong thereof having a ridge
projecting toward the central axis of the collet with the radial
spacings of the ridges being such that when a pin is inserted
therebetween the prongs are forced slightly outwardly, a guide ring
disposed around the forward end of said multi-pronged collet for
guiding a pin inserted therethrough along the axis of said collet,
and a gasket disposed forwardly of said guide ring and having an
internal configuration for effecting a water-tight seal with a
respective one of the pin projections on said plug, both of said
collets and their associated guide rings and gaskets being
contained at the rear of a receptacle in the pacer into which said
plug is insertable, and means for mechanically locking said plug in
said receptacle.
2. A pacer in accordance with claim 1 further including a retainer
disposed around each of said multi-pronged collets, the rear of
each collet being fixed to the rear of its respective retainer and
each of said retainers providing clearance around the retained
collet prongs for allowing slight outward movement thereof when a
plug pin is inserted therein.
3. A pacer in accordance with claim 2 wherein the rear end of each
retainer and its retained collet is closed.
4. A pacer in accordance with claim 3 wherein each of said guide
rings includes a tapered bore having its smaller diameter end
adjacent to the forward end of the respective collet.
5. A pacer in accordance with claim 4 wherein each of said gaskets
includes a plurality of internal ridges for securing a respective
one of said plug projections.
6. A pacer in accordance with claim 2 wherein each of said guide
rings includes a tapered bore having its smaller diameter end
adjacent to the forward end of the respective collet.
7. A pacer in accordance with claim 6 wherein each of said collets
extends slightly forward of its respective retainer and the
respective guide ring bears against the forward end of the retainer
and encloses the projecting portions of the prongs extending
therefrom.
8. A pacer connector arrangement for connecting an electrode plug
pin to a pacer circuit comprising a connector assembly for coupling
signals between the pacer circuit and the plug pin, said connector
assembly having a multi-pronged collet embedded in the pacer, each
prong thereof having a ridge projecting toward the central axis of
the collet with the radial spacings of the ridges being such that
when a pin is inserted therebetween the prongs are forced slightly
outwardly, means disposed forward of said multi-pronged collet for
guiding a pin inserted therethrough along the axis of said collet
and for effecting a water-tight seal with said plug, said collet
and said forwardly disposed means being contained at the rear of a
receptacle in the pacer into which said plug is insertable, means
for mechanically locking said plug in said receptacle, a retainer
disposed around said multi-pronged collet, the rear of said collet
being fixed to the rear of said retainer, said retainer providing
clearance around the retained collet prongs for allowing slight
outward movement thereof when a plug pin is inserted therein, and
wherein the pin extends from a projection of said plug, and said
forwardly disposed means includes a plurality of internal ridges
for securing said plug projection and effecting a water-tight seal
therewith.
9. A pacer connector arrangement for connecting an electrode plug
pin to a pacer circuit comprising a connector assembly for coupling
signals between the pacer circuit and the plug pin, said connector
assembly having a multi-pronged collet embedded in the pacer, each
prong thereof having a ridge projecting toward the central axis of
the collet with the radial spacings of the ridges being such that
when a pin is inserted therebetween the prongs are forced slightly
outwardly, means disposed forward of said multi-pronged collet for
guiding a pin inserted therethrough along the axis of said collet
and for effecting a water-tight seal with said plug, said collet
and said forwardly disposed means being contained at the rear of a
receptacle in the pacer into which said plug is insertable, means
for mechanically locking said plug in said receptacle, a retainer
disposed around said multi-pronged collet, the rear of said collet
being fixed to the rear of said retainer, said retainer providing
clearance around the retained collet prongs for allowing slight
outward movement thereof when a plug pin is inserted therein, and
wherein said collet extends slightly forward of said retainer and
said forwardly disposed means bears against the forward end of the
retainer and encloses the projecting portions of the prongs
extending therefrom.
Description
This invention relates to arrangements for connecting electrode
plugs to implantable pacers, and more particularly to pacer
connectors which do not require the use of set screws or protective
adhesives.
An implantable pacer, as supplied to the physician, is a
self-contained unit having at least one female receptacle into
which a two-pin male plug must be inserted during the implantation
procedure. Encapsulated leads are extended from the pins to
respective electrodes which are implanted in the patient's heart.
For proper pacing, it is essential that after implantation the plug
remain firmly in the receptacle and the pins make good electrical
contact with the connectors in the receptacle. It is also important
that there be an hermetic seal, that is, that body fluids not gain
access to the interior of the pacer or even to the connectors.
Prior art connectors have generally included set screws for making
positive electrical contact with each pin of the electrode plug. A
set screw is provided for each pin, and the screw head is turned
from outside the pacer to make contact with the respective pin.
Quite apart from reliability considerations, this procedure is time
consuming and therefore objectionable when carried out during the
course of an operation. Moreover, the hole for each set screw
provides a path from the connector within the pacer to the exterior
of the pacer, and body fluids might otherwise flow through the hole
even when a set screw is within it. For this reason, it is the
general practice to cover the head of each set screw with a
protective medical adhesive, as is known in the art. The
application of a medical adhesive to each set screw in this manner
is both time consuming and not perfectly reliable.
It is a general object of our invention to provide a pacer
connector arrangement which does not require the use of set screws
or protective medical adhesives, and which nevertheless insures
reliable electrical contacts and provides an hermetic seal.
In accordance with the principles of our invention, the receptacle
for each electrode plug is provided with two connectors each for
operating in conjunction with one of the two plug pins. Each
connector includes a four-pronged collet contained within a
respective retainer. The four prongs are configured to define a
central bore into which a plug pin is inserted. At the forward end
of each prong there is an internal ridge for making contact with an
inserted pin. The four ridges define a bore having an internal
diameter which is fifteen thousandths of an inch smaller than the
outer diameter of a plug pin. Each collet is held within its
retainer such that there is clearance between the exterior of each
of the collet prongs and the internal wall of the retainer. This
allows an inserted pin to force apart the four collet prongs; it is
the natural tendency of the prongs to return to their normal
position that ensures reliable electrical contact between the pin
and the prongs.
At the forward end of each collet-retainer pair there is a ring
which functions to guide the respective plug pin along the axis of
the respective collet. Forward of each guide ring is a gasket which
makes a water-tight seal with an inserted plug. Each connector
assembly thus consists of a retainer with a central collet, a guide
ring and a gasket, and two such assemblies are fixed within the
pacer receptacle into which a two-pin electrode plug is inserted.
As is known in the art, a lockpin is used to securely position the
plug within the pacer receptacle. (The connectors function to make
electrical contact between the plug pins and the pacer circuitry,
and are not designed to mechanically retain the plug in place.)
Further objects, features and advantages of our invention will
become apparent upon consideration of the following detailed
description in conjunction with the drawing, in which:
FIG. 1 depicts a type of pacer electrode plug and leads in current
use together with a mechanical lockpin used to secure the plug in
place within a pacer receptacle;
FIG. 2 is an exploded view of the connector element of our
invention;
FIG. 3 is a cross-sectional view of the assembled connector element
of our invention together with the guide ring and gasket used with
it in a pacer; and
FIG. 4 is a view similar to that of FIG. 3 but shows the connector
and associated elements in a pacer with the plug of FIG. 1 inserted
in it.
Plug and leads 10 of FIG. 1 is of a conventional type and is made
of silicone rubber. There are four ridges 24 around plug 16 and a
larger ridge 28 toward its rear. From the rear of the plug two
encapsulated leads 12 extend to electrodes (not shown) which are
connected to the heart tissue during implantation. The leads
extending through plug 16 to pins 20 which are embedded in plug
projections 18.
The plug is provided with a through-hole 22, into which a retaining
lockpin 26 can be passed. It is conventional practice for a pacer
to have a bore both above and below the plug receptacle so that
after a plug is inserted into it, a pin such as 26 can be passed
through the plug and held in the bores in the epoxy material used
to pot the pacer circuit. It is the lockpin which mechanically
holds the plug in place with a tight fit. The top of pin 26 is
shown with a ridge so that the pin can be gripped with a lockpin
tool as is known in the art for inserting it into or removing it
from the pacer.
FIG. 2 is an exploded view of the elements which comprise each
connector (exclusive of the associated guide ring and gasket).
Retainer 30 is simply a block of conductive metal, such as
stainless steel, having a long large-diameter bore 34 and a shorter
smaller-diameter bore 36. The retainer is soldered to a nickel
ribbon 32. It is the nickel ribbon which is actually mounted on the
pacer circuit board, with the ends of the ribbon being folded over
and soldered to the board as is known in the art. The collet 38 has
a central bore (of varying diameters) extending all the way through
it as will be described in detail below. Along most of the length
of the collet there are four slits which define four forwardly
extending prongs. A plug 40 is provided for insertion into the rear
of the collet bore to seal it, as will be described below. The
collet and the collet plug are also made of conductive material
such as stainless steel. (The plug is really an integral part of
the collet; the connector can be thought of as a two-piece element,
namely, a collet and a retainer. The plug is separate from the rest
of the collet only because it is easier to manufacture the collet
from two separate pieces, as will be described below.)
Referring to FIG. 3, it is apparent that collet 38 can be made from
a solid cylindrical section of stainless steel as follows. First, a
hole is drilled through the cylinder with a diameter equal to that
defined by the inner dimensions of the four ridges 58. Then a
tapered bore 48 is formed in the forward end of the collet, and the
bore in the rear of the collet is drilled to have a larger
diameter, the final bore wall being shown by the numeral 46.
Thereafter, a still larger diameter hole is drilled at the far rear
of the collet, this bore being shown by the numeral 56. In the last
step, the slots 52 are cut at 90.degree. intervals from the forward
edge of the collet along most of its length. The result is a
cylindrical section at the rear of the unit from which four prongs
extend, with a bore of varying diameters extending through the
unit.
Collet plug 40 is cylindrical in shape and has a small diameter
section 40a and a large diameter section 40b. The collet plug is
inserted into the rear of the collet and is secured by a friction
fit. The only reason for providing a small-diameter section 40a is
to allow simple initial insertion of the plug into the collet bore
since the small end of the plug is easily inserted as a result of
the loose fit. It is the rear section 40b which closes off the rear
of the collet. Since the entire connector unit, after mounting on a
circuit board, is potted in an epoxy compound, it is desirable that
none of the liquid epoxy material flow through the rear of the
collet into the central bore into which a plug pin must later be
inserted. Plug 40 seals off the rear of the collet so that the
epoxy material, during the conventional potting process, cannot
gain access to the interior of the connector unit.
The collet, with its rear plug, is then inserted into retainer 30.
This is accomplished by squeezing the four prongs together and
inserting the tips of the prongs into the small-diameter bore end
of the retainer. The collet is pushed all the way in until it is in
the position shown, with the rear end of the collet being flush
with the rear end of the retainer and the forward end of the prongs
extending slightly forward of the forward edge of the retainer.
Although the rear of the collet and retainer are fixed together, it
is apparent that the prongs 54 can be spread slightly outwardly
within bore 34 of the retainer. If this is accomplished, for
example, by the insertion of a pin whose diameter is slightly
larger than the inner diameter defined by ridges 58, then the
natural tendency of the prongs will be to spring inwardly, and the
prongs will thus tightly grip the pin.
At the forward end of the collet and its retainer there is
positioned a guide ring 62 which is preferably made of Teflon. The
rear of the guide ring has a large diameter bore 68 which fits over
the forwardly extending prongs 54, with the rear of the guide ring
resting against the forward face of the retainer. The central bore
66 of the guide ring has a diameter equal to that of the forward
end of conical bore 48. The forward end of the guide ring is
provided with an enlarged tapered bore 64. The purpose of the guide
ring is to guide a pin to a position which is central to all four
of the collet prongs. Even if the pin is not inserted into the
pacer receptacle in a position which is aligned perfectly with the
central axis of the collet, the pin is guided by guide ring 62
until the forward end of the pin is along the central axis of the
collet. (The guide ring is properly aligned with the collet and its
retainer because, as will be described below, the guide ring is
inserted into the pacer receptacle and is retained in the proper
position by the walls of the receptacle.)
Forward of the guide ring there is provided an O ring or gasket 80.
The gasket has a bore whose inner wall 70 fits over the forward end
of guide ring 62. The gasket has a plurality of internal ridges 84
which serve to grip a projection 18 on plug 16. It is into end 86
of the gasket that a pin 20 and a projection 18 are inserted in the
final assembly steps to be described below.
FIG. 4 depicts a connector assembly within a pacer and a plug 16
held in place in the pacer receptacle. It is conventional practice
to mount a pair of connectors on a circuit board and to then pot
the overall pacer circuit (including the batteries) in an epoxy
compound. (although not shown, it is also conventional practice to
cover the final potted unit with a silicone rubber boot.) It is
during the molding process that the plug receptacle is formed. The
inner wall 96 of the receptacle has a shape to accept plug 16 of
FIG. 1. The molded receptacle includes two large-diameter sections
for containing two gaskets 80. After the pacer circuit is potted
and the epoxy material has hardened, a guide ring 62 is placed
forward of each of gaskets 80, and the two assemblies are then
pushed into the receptacle. Each rubber gasket is compressed as it
is pushed in and then expands into the respective recess in the
receptacle provided to contain it. In this position, as shown in
FIG. 4, each guide ring 62 is held centrally disposed around the
respective connector element and the guide ring and the gasket are
held securely within the receptacle. The gasket cannot slide out of
the receptacle by virtue of a wall 98 in the epoxy package; when a
gasket is pushed all the way into the receptacle it expands into
the recess as shown in the drawing. An even more secure fit can be
obtained by placing some adhesive around each receptacle recess
prior to insertion of the respective guide ring and the gasket.
During implantation of the pacer, all that is required of the
physician to effect a connection of plug 16 to the pacer is to
insert the plug as shown in FIG. 4 and, while the plug is pushed
in, to insert lockpin 26. During the potting process, a hole 94 is
formed above the receptacle and a tapered bore is formed below it.
The lockpin is simply forced through the upper hole and the hole 22
in the plug into the bottom tapered bore 92. In this position, the
plug is held tightly up against the forward ends of gaskets 80. The
plug is held securely, and with a water-tight fit, within bore 96
by virtue of its ridges 24. Each of plug projections 18 is held
securely within the internal ridges 84 of a respective one of the
two gaskets, and the respective pin 20, after being guided by guide
ring 62 into a respective connector, is held there by virtue of the
fact that the four connector prongs are bent outwardly slightly
because the diameter of the pin is slightly larger than the
diameter defined by ridges 58. There is no need for a set screw for
each pin because a perfectly reliable electrical contact is made
between the prongs of each collet and the respective pin. An
hermetic seal is achieved because of the manner in which each of
gaskets 80 makes a water-tight seal around a respective one of plug
projections 18. All that is required to effectuate a reliable
connection is to insert lockpin 26 as described above.
Although the invention has been described with reference to a
particular embodiment, it is to be understood that this embodiment
is merely illustrative of the application of the principles of the
invention. For example, in the Bifocal implantable pacers marketed
by the assignee of the subject application, two receptacles (with
two connectors in each) are provided so that two electrode plugs
can be coupled to the pacer in order to provide atrial as well as
ventricular stimulation. Such a pacer is provided with two female
receptacles with a single lockpin being used for insertion through
the two receptacles and the two contained electrical plugs. The
present invention is applicable to such a pacer, with each
receptacle and its contained elements being made as shown in the
drawing. Thus it is to be understood that numerous modifications
may be made in the illustrative embodiment of the invention and
other arrangements may be devised without departing from the spirit
and scope of the invention.
* * * * *