U.S. patent number 3,768,487 [Application Number 05/236,910] was granted by the patent office on 1973-10-30 for electrode placement apparatus and pacer.
This patent grant is currently assigned to Norland Corporation. Invention is credited to Frederick A. Rose.
United States Patent |
3,768,487 |
Rose |
October 30, 1973 |
**Please see images for:
( Certificate of Correction ) ** |
ELECTRODE PLACEMENT APPARATUS AND PACER
Abstract
A heart electrode placement unit has a pair of displays, one for
an intercardiac electrocardiogram and a second for an external
sensed electrocardiogram. A pacing unit is releasably secured to
the placement unit by a plug-in connector having a switch normally
connecting a pulse source to electrode leads. The placement
connector part is connected to a switch to connect the electrode
directly to the input of the one display or reconnect the electrode
leads to the pulse source. When the connector is open, the pacing
switch automatically closes to reconnect the pulse source to the
electrode leads.
Inventors: |
Rose; Frederick A. (Fort
Atkinson, WI) |
Assignee: |
Norland Corporation (Fort
Atkinson, WI)
|
Family
ID: |
22891507 |
Appl.
No.: |
05/236,910 |
Filed: |
March 22, 1972 |
Current U.S.
Class: |
607/27 |
Current CPC
Class: |
A61N
1/372 (20130101); A61N 1/3702 (20130101) |
Current International
Class: |
A61N
1/362 (20060101); A61N 1/37 (20060101); A61N
1/372 (20060101); A61n 001/36 () |
Field of
Search: |
;128/2.5R,2.6A,2.6B,2.6F,2.6G,2.6R,2.6V,404,419P,421,422 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Furman et al., "Medical Research Engineering," Third Quarter, 1967,
pp. 29-32..
|
Primary Examiner: Kamm; William E.
Claims
I claim:
1. An electrode placement apparatus for intracardial placement of
an electrode, comprising
a multiple part circuit connection means including a first circuit
connector means and a second circuit connector means releasably
connected to the first connector means,
a pacing means having a pulsing means and an electrode connection
circuit connected to said first connector means,
an electrode placement means having electrode signal input means
for display of the output of the electrode connection circuit
means, said placement means including said second connector means,
and
selection switch means connected to said connection means to
selectively connect said electrode connection circuit to the
electrode signal input means and to the pulsing means.
2. The electrode placement apparatus of claim 1, wherein
said electrode placement means includes external electrode signal
means and display means for the output of the external
electrodes.
3. The electrode placement apparatus of claim 1, wherein
said first connector means includes a first contact member attached
to the pacing means and said second connector means includes a
second complementing member attached to the electrode placement
means,
said first contact member having electrode contact means connected
to the electrode connection means and pulse contact means connected
to said pulse means,
said second contact member having display contact means for
connection to the display means and second pulse contact means
connected to the first pulse contact means of the first contact
member,
automatic switch means being connected to said first contact member
and responsive to release of said connector means to connect the
electrode connection circuit means to the pulsing means and
responsive to interengagement of said connector means to
operatively disconnect the electrode connection circuit means from
the pulse means and operatively connect the electrode connection
circuit means to said connector means, and
said selection switch means being connected to said second contact
member for selectively operatively connecting the electrode input
means to the display means and to the pacing means for selectively
pacing the heart and for display of the heart action as appears at
the electrode connection means.
4. The electrode placement apparatus of claim 3, wherein
said electrode placement means includes a first display means
connected to said display contact means for visual display of
traces corresponding to the signal on the electrode and a second
display means, and
external electrode means connected to said second display means to
establish an external electrocardiogram.
5. The electrode placement apparatus of claim 3, wherein
said first contact member includes a socket having said electrode
contact means projecting into said socket and said pulse contact
means is longitudinally spaced from the electrode contact means and
projects into said socket, said contact means being spring
loaded,
said second contact member being a shaft and said second pulse
contact means axially spaced in accordance with the contact means
of the first contact member.
6. The electrode placement apparatus of claim 3, wherein
said automatic switch means includes a leaf spring integrally
connected to said first contact member and biased to a first
position to connect the electrode connection circuit means to the
pulsing means upon release of said connector means and moved to a
second position by the interengagement of said connector means to
open the electrode connection circuit means from the pulse means
and connect the electrode connection circuit means to said
connector means, and
said selection switch means connected to said second contact member
for selectively operatively connecting the electrode input means to
the display means and to the pulsing means for selectively pacing
the heart and for display of the heart action as appears at the
electrode connection means.
7. An electrode placement apparatus for the intracardial placement
of an electrode, comprising
a heart pacing means for generating heart stimulating pulse
signals,
electrode means for insertion into a heart,
a display means adapted to respond to signals generated by the
heart in said electrode means, and
a connection means connected to said pacing means and said display
means and including a first switch means to selectively connect
said electrode means to said pacing means and to said display
means, and a second switch means to automatically connect said
pacing means to said electrode means in response to separation of
the pacing means from the display means.
8. The electrode placement apparatus of claim 7, wherein
said display means including a plurality of aligned display viewing
members each having a separate input means,
a first of said input means being connected to said first switch
means,
a set of external heart beat sensing electrode means connected to a
second of said input means, and
an auxiliary input means connected to a third of said input
means.
9. An electrode placement unit for intracardial placement of an
electrode by releasable connection to a pacing means having a
pulsing means and an electrode connection circuit means connected
to a first connector means of a multiple part circuit connection
means, comprising
a second circuit connector means of a said multiple part circuit
connection means and releasably connected to a complementing second
connector means,
a display means having an electrode signal input means for display
of the output of the electrode connection circuit means, said
placement means including said second connector means, and
selection switch means connected to said second connector means and
to said signal input means to selectively connect said electrode
connection circuit means to the electrode signal input means and to
the pulsing means.
10. The electrode placement unit of claim 9, having external
electrode signal means and related display means for the output of
the external electrodes.
11. The electrode placement unit of claim 9, wherein said selection
switch means includes a pair of pushbutton inputs, one pushbutton
input establishing the connection to the pulsing means and the
second pushbutton input establishing the connection to the display
means.
12. The electrode placement unit of claim 9, having
said display means including a plurality of aligned display viewing
portions each having a separate input means,
a first of said input means being connected to said selection
switch means,
a set of external heartbeat sensing electrode means connected to a
second of said input means, and
an auxiliary input means connected to a third of said input
means.
13. A pacing unit for selectively connecting an electrode for
pulsing a heart and for establishing a signal in accordance with
the function of the heart for operating an electrode placement unit
having a signal display means connected to a first connector means
of a multiple part circuit connection means, comprising
a pulsing means,
an electrode connection circuit means,
a second connector means of the circuit connection means releasably
engageable with said first connector means and connected to said
pulsing means and said connection circuit means,
automatic switch means responsive to release of said first and
second connector means to connect the electrode connection circuit
means to the pulsing means and responsive to interengagement of
said connector means to operatively disconnect the electrode
connection circuit means from the pulsing means and operatively
connect the electrode connection circuit means to said first
connector means for selective connection to the display means and
to the pulsing means.
14. The pacing unit of claim 13, wherein
said automatic switch means includes contacts connected to and
forming a part of said second connector means.
15. The pacing unit of claim 13, wherein
said automatic switch means includes a leaf spring defining a first
contact member of the second connector means and biased to a first
position engaging a fixed contact member to connect the electrode
connection circuit means to the pulsing means upon release of said
connector means and moved to a second position by the
interengagement of said connector means to open the electrode
connection circuit means from the pulsing means and connect the
electrode connection circuit means to said first connection means,
and
said second connector means having a third contact member connected
to the fixed contact member for selectively operatively connecting
the electrode input means through said first connector means to the
display means and to the pulsing means for selectively pacing the
heart and for display of the heart action as appears at the
electrode connection means.
Description
BACKGROUND OF THE INVENTION
This invention relates to an electrode placement apparatus which is
particularly constructed for intercardial electrographic insertion
of a catheter for heart pacing.
The human heart automatically contracts and relaxes in a periodic
manner, functioning as a pump to circulate the blood through the
body. The heart contractions, or beats, are generally controlled by
specialized tissues of the heart. Damage to one or more components
of the heart structure may result in either a permanent or
temporary malfunctioning and in particular a disruption of the
regular rhythm of the heart. In such cases, it is important to
provide artifical means, which have been developed, for stimulating
the heart action and thereby establishing and maintaining the
regular heart beat. In a significant number of cases, heart
malfunction creates an emergency condition where time is of the
essence and the immediate stimulation of the heart is required.
Generally, artifical heart stimulating means includes a thin,
plastic coated wire, known as an electrode or, previously, as a
catheter, having a metal contact at its distal end. The electrode
is introduced through a large vein into the heart and particularly
through the right auricle and into the apex of the right ventricle.
An external electronic pulsing means, generally identified by the
term pulse generator, is interconnected to the proximal end of the
electrode and establishes a series of electrical pulses into the
heart. The heart condition may require temporary pacing or the
damage may be such that a permant pacing is required.
Generally, permanent pacing is provided by implanting a small
electronic Pacemaker within the fatty tissue overlying the
pectoralis major. The electronic pacer is, of course, connected
directly to the electrode which was implanted via the large vein in
the neck and which is run subdermally from the site of the
venipuncture to the Pacemaker.
The Pacemaker can be constructed to establish a continuous fixed
beat or through suitable constructions to provide a demand pacing
function.
The standard method of introducing the electrode into the heart has
been a generally surgical operation wherein the movement of an
electrode through the vein and into the heart is followed with the
aid of a fluoroscopic device. The physician through visual analysis
can properly manipulate an electrode into the desired position
within the heart.
Although fluoroscopic insertion has been highly satisfactory, there
are certain distinct disadvantages associated with its use. In many
instances, the pacing requirement arises under emergency conditions
with insufficient time to transport the patient to a medical center
where the majority of Pacemaker insertions are performed or even to
the necessary fluoroscopic facilities, when otherwise available.
Further, the patient may be so ill that even movement from a bed to
the fluoroscopic facilities within a center may be extremely
hazardous. Fluoroscopic insertion subjects both the patient and the
performing physician to radiation. Although this is not
particularly severe from the standpoint of the patient, as he will
not normally be subjected to more than a single operation, or a
couple of operations spaced by one or more years, the attending
physicians, particularly if they specialize in the operation and
thus perform a substantial number of such operations in a short
period, are exposed repeatedly to the x-rays and are thus subject
to accumulated radiation exposure which may be in excess of that
considered safe or desirable.
Further, because the visual insertion is a relatively delicate
procedure, the physician and assistants may tend to reject the
usual heavy lead protective clothing which is routinely recommended
in connection with fluoroscopic procedures. The x-ray room in which
the procedure is necessarily performed under the visual insertion
method is not normally a surgical facility, notwithstanding, the
procedure is basically a surgical procedure.
Additionally, the equipment employed must minimize to the greatest
possible extent the accidental impressing of an extraneous
electrical signal on the patient. Thus, the surgeon and/or
associates may accidentally form a circuit connection from the
equipment to the patient. The leakage current characteristic of the
equipment is such as to impress a current as low as the order of
ten microamperes on the patient, serious if not fatal, injury to
the patient may result. Generally, fluoroscopes are not designed
with the desirable low leakage current characteristic to establish
highly safe condition.
Although under emergency conditions it is possible and when
absolutely required, the physician will insert the alone and
without auxiliary fluoroscopic aid, this procedure cannot be
reliably employed. As an alternative to the fluoroscopic insertion
method and a blind feel method, research has indicated that the
catheter can be reliably and properly passed through the vein and
implated in the heart through intracardiac electrographic
processes. Various articles have suggested such a procedure. For
example, an article in the American Journal of Medicine in the
Apr., 1959 issue, pages 494 through 542, includes a report by a
Charles A. Bartran et al. on Intracardiac Electrography In Man. As
more fully disclosed therein, under this procedure the proximal end
of the catheter is interconnected to an electrocardiogram apparatus
with the reading providing the basis of determining the position of
the catheter. Generally, the author concluded that the
electrocardiogram obtained is sufficiently characteristic of the
location of the catheter within the chambers and vessels of the
heart to permit accurate localization of the catheter tip during
cardiac catherization. The article also notes the advantages of
this system in reducing exposure to radiation of both the patient
and the physician and further that the electrocardiogram
facilitated the detection of phenomena which would not be readily
apparent by the more conventional electrocardiogram taken with
surface attached electrodes. More recent articles have also
indicated the advantage of this system for emergency insertion of a
catheter at the bedside of the patient. An article entitled "Simple
Bedside Method for Travenous Intracardiac Pacing" by Kimball et al.
appeared in the July, 1965 issue of American Heart Journal, page 35
through 39, wherein an emergency temporary catheter pacing
procedure is disclosed.
A relatively flexible Teflon coated stainless steel wire was
introduced into a vein and connected to the precordial lead of a
direct-writers electrocardiograph machine through suitable
interconnecting clip adapters. In addition, external limb leads
were attached in the standard manner. The wire is then readily
advanced into the heart and in particular to the right atrium. Once
located, a characteristic atrial pattern was recorded on the
electrocardiograph machine. It was found that with minimal
manipulation the electrode could be properly advanced through the
heart with the platinum reading tip resting on the proper surface
within the right ventricle. The electrocardiogram from that point
was readly recognized. After proper implanation the external ends
of the intercardiac electrodes were connected to the Pacemaker and
pacing was established. The system there employed is primarily for
interim intracardiac pacing with use of a relatively flexible wire
to avoid the possible potential hazard of puncture associated with
a more conventional stiff cardiac catheter. This sytem has the
advantage of permitting bedside catheter insertion or any other
situation where it is possible to perform a venipuncture or cutdown
on a vein. A more recent article entitled "Bedside Transvenous
Cardiac Pacing" was written by Rosenberg et al. and appears in the
May, 1969 issue of the American Heart Journal identified, at Vol.
77, No. 5, at pages 697 -703. This article reports on the bedside
insertion of a soft flexible catheter in a number of patients over
a period of time under a similar procedure, with simultaneous
electrocardiograms of the intracardiac trace and a limb trace
provided by the inserted electrode and an external limb electrode.
Both articles particularly suggest the procedure as satisfactory
for temporary catheter insertion which may be employed to pace the
heart during the insertion of a permanent transvenous Pacemaker
catheter. After the insertion of a permanent electrode, the
temporary electrode is removed of course.
Notwithstanding the apparent distinct advantages of the
intracardiac electrograph method of electrode insertion it has not
been widely adopted. Generally, the apparatus employed is the
conventional electrocardiographic apparatus which is interconnected
through auxiliary connectors and the like when employed. Applicant
has realized that one of the problems presented is the lack of
special instrumentation providing for convenient and standard
operating use in the electrographic insertion process.
SUMMARY OF THE INVENTION
The present invention is particularly directed to a novel, special
electrode placement apparatus for intracardiac electrographic
procedures and which will contribute to rapid and accurate
implanting of a pacing electrode.
Generally, in accordance with a particularly novel aspect of the
present invention, an electrode pacing means having a pulsing means
and electrode connection circuit means is connected to a first
connector means for selective interconnection with a second
connector means of a complementing multiple part connection means.
The latter forms a part of an electrode placement means which
includes means for visually displaying electrocardiograph traces
and the like. A selection switch is coupled to the multiple part
connection means for selectively setting and interconnecting of the
pacing means to transmit pacing pulse energy to the electrode or to
transmit the detected signal on the electrode to the display means.
When the pacing means is disconnected from the electrode placement
means, the pacing is automatically connected to establish and
maintain pacing signals to the electrode and thence to the
patient's heart.
During an implanting operation, the electrode is inserted with an
intracardiac electrocardiogram taken from the electrode tip. When
the desired placement has been achieved, the selection switch means
is actuated to establish pacing. An externally derived
electrocardiogram indicates whether or not proper capture has been
made. If an improper capture has been made, the surgeon merely
reverses the position of the switch means to again establish the
intracardiac trace. Once stable pacing is established, the pacing
means is separated from the electrode placement means to permit
transfer of the patient, if required.
The external and internal electrocardiogram traces are preferably
displayed in side-by-side relationship to provide for direct
comparison in determining proper placement. The simultaneous
display of the internal and external traces is important because a
damaged heart displays bizarre complexes which are not easily
recognizable without comparison to a known (external) signal.
Further, when proper placement is considered to have been made, the
selection switch means is actuated to a pacing position. The pulse
means will then provide the desired pacing while anticipating
pacing action which is compared with the trace provided by the
external electrocardiogram. As previously noted, if relocation of
the catheter electrode appears necessary, the switch means is
actuated to the display mode and the traces again compared during
the necessary movement for repositioning of the electrode.
After stable pacing has been established, the pacing means is
disconnected from the electrode placement means to automatically
establish heart pacing. Under emergency operating conditions or the
like, the patient can be moved to the desired facilities without
interruption of the pacing. There is virtually no interruption of
the pacing nor is any further action required because the
separation of the pacing means automatically establishes the
desired pacing interconnection.
This provides a very simple and reliable apparatus which is
especially constructed for electrode implanting and provides an
apparatus which can be readily transported to the bedside of a
patient or other location for immediate electrode and pacer
insertion. The present invention thus provides a means for
permitting emergency implanting with the same precision normally
obtained under controlled conditions. Further, the invention
completely eliminates the necessity of fluoroscopic procedures with
the attendant radiation exposures and also permits the implanting
in the usual surgical room and under controlled, electrically safe
conditions.
In accordance with a particularly practical and novel construction
of the present invention, the electrode placement means is provided
with a plurality of visual display means having individual and
related inputs. The one input is adapted to display the
intracardiac electrocardiogram and a second display provides a
simultaneous external electrode sensed electrocardiogram. One or
more auxiliary inputs can be provided with pressure sensing means
to establish a pressure signal display or other physiological
conditions. The pacing means and the electrode placement means
include complementing connecting components having interrelated and
complementing plug-in type contact members. The pacing means
connector component includes a switch normally providing for
interconnection of a pulse source to the electrode leads. When the
pacing means is attached to the electrode placement means, the
switch is automatically actuated to disconnect the pulse means from
the electrode leads through the complementing contact members and a
selection switch of the placement means. The pacing means contact
member includes a first contact connected to the pulse source and a
second contact connected to the electrode leads. In addition, a
common contact is selectively interconnected to the electrode leads
and to the pulse source. The contact member of the electrode
placement means includes three interrelated contacts which are
interconnected to the selection switch means and to the display
means. The selection switch means includes a movable contact means
connected to a first contact of the second contact member which in
the assembled relation is connected directly to the electrode
contact of the first contact member. The switch means includes an
input contact for the display means and a pacing contact which, in
turn, is connected to a second contact of the second contact
member. The third contact of the electrode placement contact member
is connected to the third common contact of the first contact
member. Thus, in the assembled relation, the switch may be set to
connect the electrode directly to the input of the oscilloscope
display means and provide a corresponding visual display of the
heart action as sensed by the electrode. When the switch means is
connected to the pacer contact, it automatically provides a
reconnection of the electrode contact and the Pacemaker contact of
the first contact member and thereby reinterconnects the pacemaker
to the electrode. When the connector is open, as by removing of the
pacing means from the electrode placement means, the contact
members are separated and simultaneously the switch means of the
pacing means automatically closes to reconnect the pulse generator
directly to the electrode and maintain the pacing connection.
The releasable connector is conveniently a jack-type unit with the
socket mounted and formed as a part of the pacing means. The
contact members include resiliently loaded contacts.
The invention thus provides a new and novel apparatus which is
particularly adapted for the reliable and rapid implanting of an
electrode unit based on the intracardiac electrographic procedures
and provides an apparatus which can be readily and conveniently
operated without interfering with the physician's normal implanting
procedures.
BRIEF DESCRIPTION OF THE DRAWING
The drawing furnished herewith illustrates the best mode presently
contemplated by the inventor for carrying out the invention in
which the above advantages and features are clearly disclosed as
well as others which will be readily understood from the following
description.
In the drawing:
FIG. 1 is a pictorial illustration of an electrode placement
apparatus constructed in accordance with the present invention;
FIG. 2 is a schematic illustration of the pacing means shown in
FIG. 1;
FIG. 3 is a schematic view of the pacing means shown in FIG. 1
schematically illustrating the switching circuitry of the pacing
means separated from the electrode placement means; and
FIG. 4 is a similar schematic view of FIGS. 2 and 3 showing the
pacing means interconnected to the electrode placement means.
DESCRIPTION OF THE ILLUSTRATED EMBODIMENT
Referring to the drawing and particularly to FIG. 1, an electrode 1
is illustrated connected through a suitable connecting means to a
special pacing unit 2 which is adapted to provide automatic timed
pulses through the electrode 1 to the heart, not shown, for pacing
of the heart. The special pacing unit 2 is releasably attached and
interconnected to an intracardiac electrode placement unit 3 for
initial insertion of the electrode 1 into the patient. The
electrode placement unit 3 is formed with a supporting recess 4
within which the pacing unit 2 is attached with a releasable
two-piece connector means 5, as shown in FIGS. 2 - 4, providing an
electrical circuit connection between the pacing unit 2 and the
placement unit 3. The pacing unit 2 is preferably constructed in
accordance with the known functional capability of producing
electrical impulses for heart pacing. Switch means may provide for
selection of continuous periodic pulsing or demand pulsing in
response to the actual heart functioning. Further, the normal
amplitude and rate adjustment are provided.
The placement unit 3 further includes an oscilloscopic display
portion 6 having three distinct display portions or traces 7, 8 and
9 which are adapted to individually display information from
corresponding inputs. The display portion 7 is connected, as
hereinafter described, to the releasable connector means 5. The
display portion 8 is connected to external electrodes 10 which are
applied to the patient's body to establish an electrocardiogram in
the normal manner. A patient ground electrode 11 is also provided.
In addition, the third display portion 9 is connected to a set of
auxiliary input leads 12 for insertion of an auxiliary significant
detection physiological input, for example, establishing a trace in
accordance with the blood pressure by connection of a blood
pressure transducer or the like to establish a corresponding trace.
The signals, as previously noted, are simultaneously displayed one
above the other and permit the surgeon performing the electrode
placement to simultaneously view the internal electrocardiogram
derived from the electrode 1, the external electrocardiogram
derived from the external electrodes and the physiological
information derived from the auxiliary input. Each display portion
7 - 9 is provided with suitable controls to allow accurate vertical
positioning of the traces and adjustment of the relative amplitudes
of several signals, in accordance with known electronic design.
In the illustrated embodiment of the invention, the electrode
placement unit further includes a selection switch means which is
connected to the connector means 5. The illustrated selection
switch means includes a pair of push buttons 13 and 14. The one
button 13 establishes a display position in which electrode 1 is
connected to the display portion 7. The second push button 14 of
the switch means interconnects the electrode 1 to the pacing unit 2
to provide for th desired periodic pulsing of the heart. During the
automatic pacing, the surgeon can visually detect the heart action
via the external electrodes related electrocardiogram presented on
display portion 8. The simultaneous trace presentation of the
various information is a great advantage to the surgeon in
insertion to a proper placement and subsequently in determining
whether or not proper placement in fact has been made.
The pacing unit 2 is further especially constructed for novel
cooperative functioning with the placement apparatus, and a
preferred construction is shown in FIG. 2. The unit 2 includes a
pulse source 15 which may be any suitable means such as that
presently widely employed in a Pacemaker pulse generator. In
accordance with the present invention, the connection component of
connector 5 includes an automatic switching means for selective
interconnection of the pulse source 15 to the electrode 1 and to
display portion 7. The connector 5 is particularly a two-part unit
providing a releasable electrical interconnection, with a socket or
receptacle 16 formed as a part of pulsing unit 2. The receptacle 16
is adapted to receive an electrical jack 17 formed as a part of the
placement unit 3.
The illustrated receptacle 16 is a spring loaded switch unit having
a first spring contact 18 which is connected to one side of the
electrode 1 via an electrode lead 19. The spring contact 18 is
biased to normally engage a fixed contact 20 as shown in FIG. 2.
The fixed contact 20 is connected via a lead 21 to one side of the
pulse source 15. Thus, the normally closed contacts 18 and 20
define a switch connecting the one side of the electrode to the
pulse source 15. The opposite side of the electrode 1 is connected
to a common electrode lead 22 directly to the opposite side of the
pulse source 15 and thus in the normal disengaged switched position
of FIG. 2, the pulse source 15 is connected directly to the
electrode 1 and will provide desired pulsing thereto.
The switch means further includes a second spring contact 23
connected to the lead 21 and thus to the switched side of the pulse
source 15. In the separated position of FIG. 2, the spring contact
23 is not otherwise connected in the circuit of the unit 2 but
provides an external contact means for selective connection to the
placement unit 3, as hereinafter described. The switching unit
similarly includes a third contact 24 shown as a ring-like contact
connected to the common electrode lead 22.
The spring contacts 18 and 23 and the ring contact 24 are mounted
within a suitable insulating housing portion 25 which is recessed
to accept the connector jack 17. The recess is generally a
cylindrical recess with the contacts 18, 23 and 24 axially spaced
within the recess. In particular, the spring contacts 18 and 23 are
leaf-spring members having their outer ends bent and biased
inwardly into the recess opening of the housing 25. The ring
contact 24 is mounted adjacent the entrance of the housing and is
generally a U-shaped spring contact which also projects slightly
inwardly into the recess.
The jack 17 includes a contact shaft which enters the recess and
forces the spring-like contacts 18, 23 and 24 outwardly to
establish a firm electrical and physical interengagement between
the respective contacts and the aligned portion of the contact
shaft.
The contact shaft is secured to a suitable insulating housing or
support 26 within the placement unit 3 such that when the pacing
unit 3 is introduced into the recess 4 the contact shaft moves
inwardly into sliding engagement with the respective contacts 18,
23 and 24. The shaft is formed with three distinct contact portions
including a first contact 27 on the outermost end of the shaft. A
second intermediate contact 28 is spaced from the first contact 27
by a suitable insulator 29. The contacts 27 and 28 are generally
spaced in accordance with the axially spacing of the terminal ends
of the lead-spring contacts 18 and 23. In the assembled relation
therefor the spring contacts engage the first and second contacts
27 and 28 of the shaft and thereby provide for electrical circuit
interconnection. A third contact 30 is separated from the
intermediate contact 28 by a suitable insulator 31. The contact 30
is aligned with the ring contact 24 in the assembled relation of
the pacing unit 2 and the placement unit 3. The interconnection of
the contact shaft with the contacts results in the outward movement
of the spring contacts 18 and 23. The outward movement of the
spring contact 18 opens the switch to the pulse source 15 and
thereby removes the pulsing means connection to the electrode 1.
The pulse source 15 is now connected into the circuit through the
second spring contact 23 and the intermediate shaft contact 28.
The electrode 1 is now connected into the circuit through the
connection to the spring contact 18 and the shaft contact 27 and
through the common ring contact 24 and the third contact 30 of the
shaft, as follows.
Referring particularly to FIG. 3, the placement unit 3 is
diagrammatically illustrated including a first electrode signal
display preamplifier 32 connected through a three-channel
multiplexer 33 to the display portions 7 - 9 to establish the trace
in portion 7. A preamplifier 34 has its input connected to the
external trace electrodes 10 and a similar auxiliary preamplifier
35 connected to leads 12 is connected as a third input to the
multiplexer 33 to provide drive signals to the corresponding
portions of the oscilloscope display 7 - 9.
The selection switch means 13 - 14 is connected to the contact
member 17 and connects the electrode 1 to the preamplifier 32, or
to the pulse source 15. The illustrated selection switch means is a
single pole, double throw unit having a common pivoted pole 36
connected to the end contact 27 of the contact shaft. The pole 36
is selectively and oppositely movable by the buttons 13 and 14
between engagement with a pacing contact 37 and a display contact
38. Contact 37 is connected directly to the intermediate contact 28
of the contact jack. Contact 38 is connected as an input to the
preamplifier 32. The opposite sides of the preamplifier 32 is
connected directly to the third contact 30 of the jack.
In the assembled relationship shown in FIG. 1 and FIG. 3, the pulse
source 15 is disconnected from the electrode 1 at the contact 20
and is interconnected into the circuit through the external
connection of contact springs 18 and 23 to the interrelated
contacts of the placement contact member 17.
WIth the selection switch means in the display position, the
electrode leads 19 and 22 are connected directly as the input to
the related preamplifier 32, as follows. Lead 19 is connected to
the spring contact 18 and via the shaft contact 27 to the common
pole 36 of the selection switch means. The pole 36 is connected via
the display contact 38, in the assumed position, to the one side of
the preamplifier 32. The opposite side of the preamplifier 32 is
connected via the third contact 30 of the jack, the ring contact 24
and the lead 22 to the opposite side of the electrode. Thus, in
this position the signal output of the electrode 1 is displayed on
the oscilloscope and particularly in portion 7 to provide an
indication of the position of the electrode tip within the
heart.
In the alternate position of the selection switch means and
particularly in the pacing position, the electrode leads 19 and 22
are reinterconnected to the pulse source 15.
The Pacemaker lead 21 is connected to the actuated spring contact
23 and thus to the intermediate contact 28 of the jack. The pacing
contact 37 of the selection switch means which is now engaged by
the common pole 36 is connected to contact 28. The common pole 36
is also connected to the contact 27, now engaged by the spring
contact 18 to complete a connection of the power source lead 21 to
the electrode lead 18. The opposite side of the electrode 1 is
connected via the lead 22 directly to the opposite side of the
pulse source 15. Thus, in this position the electrode lead 19 is
disconnected from the preamplifier 32 and connected to the pulse
source 15 to provide for automatic pulsing of the electrode 1 and
the corresponding signaling of the heart.
To insert the electrode 1 into the patient, the special pacing unit
2 is assembled with the placement unit 3. The external electrodes
10 are properly attached to the patient's body along with the
common ground electrode 11 connected to the patient's leg. The
pressure transducer or other auxiliary means is interconnected to
amplifier 35 as the third input. The electrode 1 is then introduced
into the patient's vein with the selection switch means 13 - 14 in
the display position. During the electrode placement, the surgeon
simultaneously views the external electrocardiogram trace on
portion 8, the internal electrocardiogram trace on the portion 7 as
well as the auxiliary physiological information presented on the
portion 9. When the trace portion 7 indicates that proper placement
has been achieved, the selection switch means 13 - 14 is actuated
to the pacing position and the results are observed. If a proper
capture has been achieved, the heart action will be readily
apparent by a review of the external electrocardiogram trace on
display portion 8. If proper capture had not been obtained, the
external electrocardiogram immediately reflects such information to
the surgeon. To relocate the electrode, the surgeon merely returns
the switch means 13 back to the display mode and again observes the
internal trace directly without the necessity of making any other
changes in the circuit or apparatus.
Once stable pacing has been established, the pacing unit 2 is
disconnected from the pacing unit 3. The contact 18 of the first
contact member 16 is released to connect lead 19 to the pulse
source 15 via contacts 18 - 20 and lead 21. There is no
interruption of the pacing and no new connection need be made to
the patient to maintain the already desired established pacing. The
patient is then in condition for removal back to his room or has
been provided with the necessary pacing assembly without the
necessity of any transport to or from his bed.
After removal of the pacing unit, the pacing unit can be attached
to the patient's arm or the like to maintain the desired pacing.
If, subsequently, a small permanet Pacemaker is to be implanted
within the patient's body the inserted electrode can be connected
to the permanent Pacemaker. Alternatively, emergency insertion of a
temporary pacing means unit may be made in accordance with the
teaching of the present invention. Subsequently, the temporarily
inserted electrode can be employed to maintain proper pulsing of
the heart while a permanent electrode is inserted into the heart
and connected to a permanent Pacemaker, after which the temporary
electrode is removed. Thus the various modifications to the present
invention can be made if desirable for any reason. The present or
illustrated embodiment of the invention, however, provides a
relatively inexpensive construction employing a common selection
means for any one of a number of different pacing units for
providing maximum convenience to the surgeon which is, of course,
of very great practical significance in view of the delicate nature
of the implanting operation under the most favorable
circumstances.
Although described in the above preferred construction, various
modifications can be made within the scope of the present
invention. Although the detection switch means is shown as a part
of the electrode placement unit, the pacing unit can be provided
with the desired switching means with the interconnecting contacts
providing for the selective intercircuit connection. The pacing
unit will not be of the variety which will be directly implanted
into the body as a permanent Pacemaker and consequently the
minaturization and the like is not as important. The switching
means is, however, preferably placed on the placement unit to
minimize the expense and the like. Further, if desired, the
switching means may be eliminated and the insertion and removal of
the pacing unit employed as the switching unit for selectively
establishing the automatic pacing and the interconnection of the
electrode unit to the placement unit. This, of course, would
require the removal and insertion of the pacing unit if it is
desired to check the capture and thus does not provide as
convenient a method as the relatively inexpensive concept of
providing the separate selection switch means.
The present invention thus provides a very convenient and reliable
instrumentation which permits convenient emergency implanting as
well as an improved implanting under surgical room conditions
without the necessity for fluoroscopic viewing.
The illustrated embodiment employs a pulse source unit especially
constructed to fit within a recess in the placement apparatus.
Various pulse sources are presently manufactured and cannot be used
as such. As a practical solution, the placement apparatus may be
constructed without a special Pacemaker plug in the recess and
provided with an adapter means to accommodate the various available
pulse sources. The adapter means would be connected to the output
of the Pacemaker and have means connected to the placement
apparatus and to the electrodes. The adapter would further have the
necessary internal switching to produce the previously described
function and operation. Further, the outer end assembly of the
adapter could be a two-piece unit which, when separated, provides
the automatic connection of the electrodes to the pulse source.
Alternatively the outer end of the assembly could be a single unit
which was separated from the pulse source and electrodes and the
electrodes then connected directly to the output of the pulse
source.
Various modes of carrying out the invention are contemplated as
being within the scope of the following claims, particularly
pointing out and distinctly claiming the subject matter which is
regarded as the invention.
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