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Having thus described the preferred embodiment, the invention is now
claimed to be:
1. A vacuum delivery apparatus for laparoscopic implant of an operatively
associated diaphragm pacer, the apparatus comprising:
a first housing adapted on a first side for releasable attachment to said
operatively associated diaphragm pacer;
a second housing connected to said first housing and including:
first vacuum source connection means for connecting the second housing to a
first operatively associated vacuum source; and,
first port means defining a first opening on a first side of the second
housing in fluid communication with said first vacuum source connection
means; and,
a third housing connected to said first housing and including:
second vacuum source connection means for connecting the third housing to a
second operatively associated vacuum source; and,
second port means defining a second opening on a first side of the third
housing in fluid communication with said second vacuum source connection
means.
2. The apparatus according to claim 1, wherein: said first port means is
adapted to communicate vacuum from said first operatively associated
vacuum source to the first side of the second housing through the first
vacuum source connection means; and,
said second port means is adapted to communicate vacuum from said second
operatively associated vacuum source to the first side of the third
housing through the second vacuum source connection means.
3. The apparatus according to claim 2, wherein the first side of the first
housing, the first side of the second housing and the first side of the
third housing are substantially disposed in a single plane.
4. The apparatus according to claim 3 further comprising:
a first elongate vacuum tube, connected between said first vacuum source
connection means and said first operatively associated vacuum source, for
communicating vacuum from said first operatively associated vacuum source
to said second housing; and,
a second elongate vacuum tube, connected between said second vacuum source
connection means and said second operatively associated vacuum source, for
communicating vacuum from said second operatively associated vacuum source
to said third housing.
5. The apparatus according to claim 4 further comprising:
first connecting means for loosely connecting said second housing to said
first housing; and,
second connecting means for loosely connecting said third housing to said
first housing.
6. The apparatus according to claim 5, wherein said first and second
connecting means comprise said first elongate vacuum tube.
7. The apparatus according to claim 6, wherein said first housing and said
third housing are both adapted to loosely receive said first vacuum tube.
8. The apparatus according to claim 7 further comprising:
a manual positioning member;
an interface defined by said first housing, the interface being adapted to
releasably receive a first end of said manual positioning member; and,
tether means attached to said interface defined by said first housing.
9. The apparatus according to claim 8, wherein said manual positioning
member is adapted on said first end to axially receive said tether means.
10. The apparatus according to claim 9, wherein said interface includes a
first keyed portion and said manual positioning member includes a second
keyed portion adapted for selective mated coupling with said first keyed
portion.
11. The apparatus according to claim 9, wherein said manual positioning
member is adapted to axially receive said tether means for the length of
the manual positioning member.
12. The apparatus according to claim 1 further comprising:
a manual positioning member;
an interface defined by said first housing, the interface being adapted to
releasably receive a first end of said manual positioning member; and,
tether means attached to said interface defined by said first housing.
13. The apparatus according to claim 12, wherein said manual positioning
member is adapted on said first end to axially receive said tether means.
14. The apparatus according to claim 13, wherein said interface includes a
first keyed portion and said manual positioning member includes a second
keyed portion adapted for selective mated coupling with said first keyed
portion.
15. The apparatus according to claim 14, wherein said manual positioning
member is adapted to axially receive said tether means for the length of
the manual positioning member.
16. A laparoscopic pacer placement apparatus comprising:
a diaphragm pacer;
a collective arrangement of relatively moveable connected portions, the
arrangement including pacer connecting means in the form of a pocket on a
first side of the collective arrangement selectively releasably attaching
to said diaphragm pacer;
vacuum source connection means adapted to connect said collective
arrangement to an operatively associated external vacuum source; and,
means defining an opening on said first side of the collective arrangement,
the opening defining means in fluid communication with said vacuum source
connection means and adapted to communicate vacuum from said associated
vacuum source to diaphragm tissue adjacent said arrangement through said
opening.
17. The apparatus according to claim 16, wherein said collective
arrangement comprises first, second and third portions.
18. The apparatus according to claim 17, wherein said first, second and
third portions are first, second and third rigid members respectively,
loosely connected for an overall flexibility of said collective
arrangement.
19. The apparatus according to claim 16, wherein said collective
arrangement is adapted to move in substantial correspondence with movement
of said diaphragm tissue.
20. The apparatus according to claim 16, wherein said collective
arrangement includes independently moveable portions.
21. A vacuum delivery device for laparoscopic implant of an associated
diaphragm pacer, the device comprising:
a first member connected to a first operatively associated external vacuum
source;
a first vacuum port on the first member connected to the first vacuum
source;
a second member connected to the first member and adapted for releasable
attachment to the associated diaphragm pacer;
a third member connected to the second member and connected to a second
operatively associated external vacuum source; and,
a second vacuum port on the third member connected to the second vacuum
source.
22. The device according to claim 21, wherein:
the first port is adapted for communicating vacuum from the first vacuum
source; and,
the second port is adapted for communicating vacuum from the second vacuum
source.
23. The device according to claim 22, wherein the first and second vacuum
ports are disposed in a single plane.
24. The device according to claim 22 further comprising:
first vacuum communicating means for communicating vacuum from the first
vacuum source to the first member; and,
second vacuum communicating means for communicating vacuum from the second
vacuum source to the third member.
25. The device according to claim 24 further comprising means for
connecting the first member to the second member and means for connecting
the second member to the third member.
26. The device according to claim 25, wherein the means for connecting the
first member to the second member and the means for connecting the second
member to the third member comprise the second vacuum communicating means.
27. The device according to claim 26 further comprising:
a manual positioning member;
an interface slot defined by the second member, the interface slot being
adapted to releasably receive a first end of said manual positioning
member; and,
a tether attached to the interface slot.
28. The device according to claim 27, wherein said manual positioning
member is adapted on said first end to axially receive said tether.
29. The device according to claim 28, wherein said interface slot includes
a first keyed portion and said manual positioning member includes a second
keyed portion adapted for selective mated coupling with said first keyed
portion.
30. The device according to claim 28, wherein said manual positioning
member is adapted to axially receive said tether means for the length of
the manual positioning member.
31. The device according to claim 21 further comprising:
a manual positioning member;
an interface defined by the second housing, the interface being adapted to
releasably receive a first end of said manual positioning member; and,
tether means attached to said second housing at said interface.
32. A method for laparoscopically placing an electrode at an optimal site
on a body tissue comprising:
a) receiving an electrode on a first side of a vacuum delivery apparatus;
(b) placing the vacuum delivery apparatus through a laparoscopic port and
into a body;
c) positioning the first side of the vacuum delivery apparatus on a body
tissue at a first site;
d) vacuum attaching the vacuum delivery apparatus to the body tissue by
connecting the vacuum delivery apparatus to an operatively associated
external source of vacuum; and,
e) during said vacuum attaching, applying an electrical signal to said
electrode to stimulate the body tissue.
33. The method according to claim 32 further comprising the steps of:
f) releasing the vacuum delivery apparatus from the body tissue by
disconnecting the apparatus from said operatively associated external
source of vacuum;
g) repositioning the first side of the vacuum delivery apparatus on said
body tissue at a second site; and,
h) repeating steps d and e. |
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Description |
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BACKGROUND OF THE INVENTION
The present invention relates to the art of electrical activation of the
diaphragm using epimysial electrodes.
It is to be appreciated that the invention is also applicable to control
other nerve groups through electrical activation using epimysial
electrodes.
It is possible to support ventilation in patients with chronic ventilatory
insufficiency using a diaphragm pacer device. In broad terms, these
devices pass a small amount of electric current through a pair of
electrodes placed on the diaphragm muscle itself. The current passes
through the diaphragm muscle thereby activating the phrenic nerves which
are proximate the placement of the electrode pair, on the opposite side of
the muscle. A proportion of the current may also pass through tissues
other than the phrenic nerve and thus have no effect on the phrenic
nerves. Since the proportion of current affecting phrenic nerve activation
depends on the distance between the electrode and the phrenic nerves,
electrode placement is critical. In any case, by passing the small amount
of electric current through the pair of properly placed electrodes on the
diaphragm muscle, the phrenic nerves are activated in turn causing a
contraction of the diaphragm muscle, the primary muscle used for
breathing. The diaphragm muscle contraction draws air into the lungs and
the patient is ventilated. Although the above approach appears to be
simple, past attempts at diaphragm pacing have met with limited success
for a variety of reasons.
The general idea of stimulating the phrenic nerve for ventilation was
investigated by Sarnoff in the late 1940's (Sarnoff 1948). Sarnoff's work
was made a clinical reality by Glenn in the 1960's (Glenn 1973, Glenn
1988). In those systems, the electrodes are "cuffs" made of silicon rubber
with platinum stimulating surfaces which are placed directly on the nerve
in the neck or thorax. The electrodes themselves may be unipolar or
bipolar but the current trend is to implant electrodes of the unipolar
type. FIG. 1A illustrates a unipolar electrode 10 for diaphragm pacing.
FIG. 1B illustrates a bipolar electrode 20 also for diaphragm pacing. The
unipolar electrode 10 includes a first electrode 12 for placement around
the phrenic nerve and an anode 14 located somewhere in the body of the
patient. A pulse of current is applied to a first connector 16, through
the first electrode 12. The current passes through the body tissues into
the anode 14 and out of the diaphragm pacing system 10 through a second
connector 18. A reversal of the above-described flow occurs for a second
current pulse immediately following the first. After a short delay, the
pair of current pulses is repeated. This repetition continues as long as
diaphragm muscle contraction is desired. Current flowing from the first
electrode 12 to the anode 14 or from the anode 14 and to the first
electrode 12 stimulates the phrenic nerves inbetween.
FIG. 1B illustrates a bipolar electrode wherein a first electrode 22 is
electrically isolated from a second electrode 24 using suitable insulating
material. As illustrated in the FIGURE, the phrenic nerve is held between
the first and second electrodes 22, 24 by placing a suture in the
electrode extensions 23, 25. The first electrode 22 is connected to a
first connector 26 and the second electrode 24 is connected to a second
connector 28. As with the system illustrated in FIG. 1A, current may be
applied between the electrode pair 22, 24 in either polarity for suitable
activation of the phrenic nerves.
Although the above-described systems perform adequately, a number of
problems exist. One problem is that the implant procedure for installing
either the unipolar electrode 10 or the bipolar electrode 20 is difficult
and invasive. Also, the electrodes themselves impose a risk of
irreversible damage to the phrenic nerve through contact therewith. As a
result, the devices of FIGS. 1A and 1B have not been well accepted in the
medical community. Unfortunately, as a result, the full potential of
diaphragm pacing has not been realized through the reluctance to accept
these devices.
Another diaphragm pacer is illustrated in FIG. 1C. This pacer 30 uses a
similar type of electrode as the device of FIG. 1A placed in a similar
location at the phrenic nerve. However, the pacer 30 illustrated in FIG.
1C uses four electrodes 32 placed around the phrenic nerve 34 in a manner
slightly different than that possible with the unipolar electrode 10 or
the bipolar electrode 20. The main difference in the system illustrated in
FIG. 1C is that a four pole sequential nerve stimulation is possible
through selective stimulation of pairs of electrodes 32. Also, the pacer
30 is capable of changing anode and cathode configurations of the
electrodes during stimulation. Although the pacer 30 offers significant
advantages over the earlier described systems, the basic problems remain
including the difficulty in implanting the apparatus, the invasive nature
of the surgery and the possible risk of irreversible damage to the nerve.
Accordingly, other systems have been developed for electrical activation of
respiratory muscles by methods other than phrenic nerve cuff electrodes.
Some of these systems are described in "Electrical Activation of
Respiratory Muscles by Methods Other Than Phrenic Nerve Cuff Electrodes",
D. K. Peterson, T. Stellato, M. L. Nochomovitz, A. F. DiMarco, T. Abelson
and J. T. Mortimer, Diaphragm Stimulation Symposium at Cardiostim 1988,
Jun. 15-18, 1988, pages 854-860.
With reference now to FIG. 1D, a prior art intramuscular diaphragm
stimulating electrode is illustrated. The electrode is shown, extending
from the tip of a hypodermic needle 42. The electrode itself is comprised
of a polymer barb set 44, a monofilament barb 46 and a coiled multistrand
stainless steel wire with teflon insulation. The insulation of the wire
ends at the barbs allowing electrical contact between the bare wires and
the surrounding tissue. The polymer barb set 44 and the monofilament barb
46 are connected to an associated electrical stimulating device by an
extension of the monofilament that passes through the center of the coil
of wire 48. The wire 48 carries current from the electrical apparatus to
the polymer barb set and the monofilament barb.
In use, the intramuscular diaphragm stimulating electrode 40 is urged down
through the hollow body of a hypodermic needle far enough to permit the
monofilament barb 46 to spring radially away from the wire 48. The wire is
then retracted leaving only the monofilament barb exposed at the tip of
the hypodermic needle. The monofilament barb indicates the depth of the
needle insertion into the diaphragm during device implant. Although this
system provides excellent results, placement of the electrode itself is
critical to the success of the procedure. To help with placing the
electrode, a laparoscope is inserted into the abdominal space and the
surface of the diaphragm itself is observed to locate an appropriate
implant site. Optimal theoretical placement of the electrode is known
using a "map" of the diaphragm based on anatomical landmarks. However, it
is often impossible to tell between patients which point would be most
optimal because anatomical landmarks are patient dependent. However,
equipped with the barbed intramuscular diaphragm stimulating electrode 40
illustrated in FIG. 1D, surgeons do not have the luxury of multiple
attempts at locating an optimal site.
The present invention contemplates a new and improved technique for phrenic
nerve stimulation and location of implant sites for diaphragm pacing
electrodes.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, an electrode
configuration is provided for establishing uniform current densities
between the electrode and tissue immediately adjacent the electrode.
In accordance with another aspect of the present invention, an apparatus
and method are provided whereby an electrode is placed in intimate contact
with the diaphragm muscle and held in place by a vacuum. An electrical
current is applied to the electrode such that the muscle activation may be
observed.
In this manner a method of locating an optimal electrode implant site on
the diaphragm is provided. The electrode is connected to an associated
vacuum assist delivery device which maintains the electrode in close
contact with the diaphragm muscle for test stimulation. Movement of the
electrode over the diaphragm is possible through controlled vacuum
application.
One advantage of the present invention is that it enables surgeons to
locate an optimal electrode implant site without damage to the diaphragm
muscle.
Another advantage of the present invention is that the current densities
through the electrode are maintained to be uniform.
Another advantage of the present invention is that a tethered wrench is
provided for manipulation by the surgeon for translation and rotation of
the vacuum assist delivery device over the diaphragm muscle.
Still further advantages of the present invention will become apparent from
the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may take form in certain parts and arrangements of parts, and
in various steps and arrangements of steps. The drawings are only for
purposes of illustrating the invention and are not to be construed as
limiting it.
FIGS. 1A-1D are elevational views of prior art phrenic nerve stimulation
apparatus;
FIGS. 2A and 2B are cross-sectional illustrations of the electrode
configurations used with the diaphragm pacer of the present invention to
provide uniform current density;
FIGS. 3A-3C are top, front and side profile views of a disk used as the
stimulating electrode surface of the present invention;
FIGS. 4A and 4B are side and profile views of the strain relief coil used
for the epimysial electrode of the present invention;
FIGS. 5A-5C are a top partial cutaway views of the disk and strain relief
coil assembly of the present invention, and cross-sectional front and side
views of the disk and strain relief coil assembly of the present
invention;
FIG. 6 is a detailed, cross-sectional illustration of the disk and coil
assembly of FIGS. 5A-5C with a lead wire assembly attached thereto;
FIGS. 7A and 7B are top and detailed cross-sectional views of the overall
assembly enclosed in a silicon rubber housing;
FIG. 8 is a perspective view illustrating the vacuum delivery device for
use with a diaphragm pacer according to the present invention; and,
FIGS. 9A and 9B are partial cutaway side and end profile views of the
wrench used with the vacuum delivery device of the present invention
illustrated in FIG. 8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIGS. 2A and 2B, the stimulating surface of the electrode
comprising the ventilator prosthesis of the present invention may be
either hemispherical 52 or a flat surface 54 within a well of insulator
material 56. In either case, the current density of the electrodes 52, 54
with respect to the surrounding tissue, represented in the FIGURES as a
saline solution 58, is critical. Uniform current density through the
electrode surface prevents corrosion of the electrode and reduces damage
to the tissue. To reduce current density and make a more reliable
electrode, the surface area of the electrode contacting the tissue is 10
mm.sup.2. A maximum current amplitude of 20 milliamps at a maximum
frequency of 50 Hz, having a pulse width of less than 200 microseconds can
be used safely for an electrode with a surface area of 10 mm.sup.2.
Each of the electrodes 52, 54 illustrated in the FIGURES are formed of
stainless steel. The electrodes could be formed of iridium oxide to
increase the safety factor for the above stimulus parameters. The circular
stimulation surface of the hemispherical electrode 52 is preferably 1.75
mm in radius wherein a 10 mm.sup.2 surface area is provided. In any case,
each of the electrodes 52, 54 are generally encapsulated in an insulating
material 56 and have a surface area carefully selected according to an
intended stimulation signal. Since the surface conducts electricity
between the electrode and the tissue, prevention of corrosion and reduced
damage to the tissue is of utmost importance.
With reference now to FIGS. 3A-3C, the stimulating surface of the diaphragm
pacer of the preferred embodiment is illustrated as being formed of a disk
60. The disk is generally circular having a flat top 62 and bottom 64 for
the electrode with a stimulating surface in a well. The electrode with a
hemispherical stimulating surface has a hemispherical protrusion on the
bottom surface. A transverse bore 66 is provided running entirely through
the disk 60. The bore is appropriately sized to receive a strain relief
coil 70 as illustrated in FIGS. 5A and 5C. The strain relief coil 70
(FIGS. 4A, 4B) is received into the bore 66 (FIGS. 5A-5C) but leaving a
slight amount of the strain relief coil extending from the bore in a
"pigtail" configuration. The end of the strain relief coil 70 opposite the
pigtail is confined to remain within the disk 60 such that the strain
relief coil 70 extends from the disk 60 only on a single end. The strain
relief coil 70 is fixed in this position in the bore 66 by a weld of the
two pieces.
With reference next to FIG. 6, the disk 60 with the strain relief coil 70
received therein, is further provided with a coiled lead wire 80
co-axially received within the strain relief coil 70. In the preferred
embodiment, the coiled lead wire 80 is a multistranded stainless steel
wire. The multistranded stainless steel wire is ideally suited for
carrying current from a stimulator apparatus to the stimulating surface 64
of the disk 60. With continued reference to FIG. 6, the coiled lead wire
80 is formed into a helix having insulation removed from one end thereof
(left end in FIG. 6). The helical wire 80 is passed through the strain
relief coil 70 and the deinsulated wire is connected to the disk coil
assembly at 82. Since the coiled lead wire of the preferred embodiment is
very fine, the strain relief coil 70 as illustrated in the FIGURE is used
to discourage severe bends at the area where the wire 80 meets the disc
60. That is, the coiled lead wire 80 is surrounded by the strain relief
coil 70 as both exit from the bore 66 of the disk 60. A polypropylene
monofilament plug 84 is inserted coaxial with both the strain relief coil
70 and the coiled lead wire 80. The coiled lead wire 80 is suitably
provided with a deinsulated segment which is passed through the strain
relief coil 70 and welded to the disk 60 at a weld joint 82. Once welded,
the polypropylene plug 84 is inserted to prevent transfer of longitudinal
stresses on the coiled lead wire to the weld joint 82.
The last step in the fabrication of the diaphragm pacer, with reference to
FIGS. 7A and 7B, is encasement of the entire assembly illustrated in FIG.
6 in a silicone rubber form 90 having a flat bottom surface 92 and a
strain relief portion 94. It is to be noted that the diaphragm pacer
electrode assembly 96 illustrated in FIGS. 7A and 7B has a stimulating
surface formed of the type illustrated in FIG. 2A. That is, the
stimulating surface of the device 96 is a flat surface 98 of the bottom 64
of the disk 60 (FIG. 6). The well walls 97 are formed by the silicone
covering 90 to a desired depth d illustrated in FIG. 2A. Also, as shown in
FIG. 7A, the well is circular having a radius a as shown in FIG. 2A.
It is to be further noted that the electrode assembly 96 may also be formed
around a suitably shaped bottom surface 64 of the disk 60 comprising a
hemispherical electrode surface such as illustrated in FIG. 2B. In that
case, the hemispherical surface would extend beyond the bottom 92 of the
assembly 96 as illustrated by the dashed line 98' which is exaggerated for
the purpose of illustration.
FIG. 8 illustrates the vacuum delivery device 100 for laparoscopic implant
of the diaphragm pacer. In general, the vacuum delivery device 100
provides a means of placing the epimysial electrode at the optimal point
on the muscle for phrenic nerve stimulation. The vacuum delivery device
100 is designed to carry the epimysial electrode through a port and into
the abdomen during a laparoscopic procedure, and hold the electrode
tightly against the diaphragm muscle surface for testing phrenic nerve
activation. The vacuum delivery device provides testing at many potential
implant sites because the electrode can be secured, released and resecured
to many locations on the muscle surface. When the implant site is
identified, the vacuum delivery device holds the electrode tightly against
the diaphragm muscle until it can be secured using an endoscopic stapler
(not shown). Suction provides the temporary holding mechanism and the
movement of the epimysial electrode is controlled by the surgeon using a
specialized tool which will be described in greater detail below.
With continued reference to FIG. 8, the vacuum delivery device 100 includes
three (3) basic members. The first member 110 is rectangular having
continuous surfaces on three sides. A left side surface of the first
member 110 as viewed in FIGURE is adapted to receive a first vacuum tube
102 at a first opening 112 and to fixedly receive a second vacuum tube 104
at a second opening 114. The first opening 112 is merely an enlarged bore
through the first member 110 sized slightly larger than the outer diameter
of the first vacuum tube 102. The first member 110 is provided on a bottom
surface as viewed in the drawing with a first vacuum port 116. The vacuum
port 116 presents a cavity toward the surface of the diaphragm muscle. The
diaphragm is represented in the FIGURE as a planar surface 118. As can be
seen in the FIGURE, the first vacuum port 116 is connected through second
port 114 to the second vacuum tube 104. Fluid suction as by the
application of a suitable vacuum apparatus to the second vacuum tube 104
causes the first member 110 to adhere to the surface 118 due to the
suction at the first vacuum port 116.
A second vacuum port 126 is provided on the bottom of a second member 120
as viewed in the FIGURE. The second vacuum port 126 opens towards the
surface 118 of the tissue. The second member 120 is ported to receive the
first vacuum tube 102 at an opening 122. Both vacuum tubes 102, 104 are
suitably connected to the first and second members 110, 120, by an
adhesive glue, a weld, or the like.
The vacuum delivery device 100 illustrated in FIG. 8 includes a third
member 130 having a bore therethrough 132 which is suitably sized to be
slightly larger than the outer diameter of the first vacuum tube 102.
Also, the third member 130 is provided, on the bottom as viewed in the
FIGURE, with a suitable cavity 134 to receive the electrode 96 illustrated
in FIGS. 7A and 7B. The electrode fits closely and is releasable from the
cavity 134. The top of the third member 130 defines a hexagonal opening
136 receiving a corresponding ball head hexagonal wrench 140.
With reference to both FIGS. 8 and 9A-9B, the use of the hexagonal wrench
140 with the vacuum delivery device 100 will be described. In general, the
ball head hexagonal wrench 140 includes a male hexagonal tip portion 142
defining a spherical hexagonal male member 144. The spherical hexagonal
male member on the tip 142 is provided with a bore receiving a tether 150
which is secured on one end to the third member 130 of the vacuum delivery
device generally denoted as 100. In the preferred embodiment, the tether
150 is a polypropylene filament.
The major portion of the ball head hexagonal wrench is formed from a 316 L
stainless steel rigid tube 148. The tether 150 is secured on one end to
the third member 130 and is threaded through both the head 142 and the
elongate portion 148 of the ball head hexagonal wrench and beyond.
Broadly viewed, the vacuum delivery device 100 defines an overall flexible
housing as provided by the spaced-apart and separate first, second and
third members 110, 120 and 130 respectively. Collectively, the first
through third housing members are arranged on a first side for releasable
attachment to the diaphragm pacer electrode 96. The first side of the
composite housing further includes a plurality of vacuum ports 116 and 126
for communicating vacuum from the hoses 104 and 102 respectively, to the
operatively associated diaphragm surface 118.
In use, the apparatus illustrated in FIGS. 8 and 9A-9B provides a surgeon
with positive control over the placement of the electrode assembly 96
through the operation of the first and second vacuum tubes 102, 104 and
the ball head hexagonal wrench 140. In particular, the apparatus is
inserted into the abdominal cavity with the ball head hexagonal wrench 140
received into the hexagonal opening 136 of the third member 130. Upon
finding a first appropriate location on the surface of the diaphragm
muscle, the vacuum is applied to the first and second vacuum tubes 102,
104, causing the first and second members 110, 120 to stick to the surface
118 of the tissue due to the suction in the first and second vacuum ports
116, 126. Next, with the vacuum on the tubes 102, 104 being maintained,
the ball head hexagonal wrench 140 is withdrawn from engagement with the
third member 130. According to the description above, the ball head
hexagonal wrench 140 remains only loosely connected to the third member
130 through the tether 150. The tether being formed of polypropylene
filament is flexible enough to permit movement of the first, second and
third members 110, 120, and 130 on the surface 118 of the tissue without
the influence of the rigid ball head hexagonal wrench 140. Then, current
is passed through the electrode causing the diaphragm muscle to move
separate and apart from the ball head hexagonal wrench 140. The quality of
the selected stimulation point is thereby evaluated without the influence
of the wrench 140.
In the event that the selected point is of marginal or poor quality judging
from the diaphragm's response to the electrical stimulation, the ball head
hexagonal wrench 140 is reinserted into the third member 130. Insertion of
the ball head hexagonal wrench is guided by the tether 150 by grasping the
tether extending beyond the tube 148 (not shown) and sliding the tube over
the tether toward the third member 130 and into the socket 136. This
procedure is performed while maintaining the vacuum applied to the first
and second vacuum tubes 102, 104.
Once the ball head hexagonal wrench 140 is secured into the third member
130, the suction is removed from the vacuum tubes 102, 104 causing the
first and second members 110, 120 to release their grip caused by the
suction on the surface 118 of the diaphragm muscle. The first, second and
third members 110, 120, and 130 connected directly to the ball head
hexagonal wrench 140 and indirectly through the first vacuum tube 102 are
translatable and/or rotatable by the surgeon merely by manipulating the
tube 148 of the wrench 140. This procedure is repeated until the optimal
placement point is located whereupon the electrode assembly 96 is stapled
to the diaphragm using an endoscopic stapler (not shown).
The invention has been described with reference to the preferred
embodiment. Obviously, modifications and alterations will occur to others
upon reading and understanding the preceding detailed specification. It is
intended that the invention be construed as including all such alterations
and modifications insofar as they come within the scope of the appended
claims or the equivalents thereof.
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