Note: Descriptions are shown in the official language in which they were submitted.
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TITLE OF THE INVENTION
1NSUFFLATOR AND METHOD OF USE
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to, and is a continuation-in-part of, U.S.
application
no. 10/324,050, filed on December 20, 2002, currently allowed, which is a
continuation
application of application serial no. 09/598,453, issued as USP 6,497,687;
which claims the
benefit of priority to provisional application serial no. 60/140,409, filed
June 22, 1999 and
also claims priority to provisional application no. 60/452,040, filed on March
6, 2003, and
provisional application no. 60/494,122, filed on August 12, 2003, each to
Blanco, the
disclosures of which are incorporated by reference herein in their entireties.
DESCRIPTION OF THE »TVENTION
An insufflator is a needle-like device through which a gas or other fluid can
be
injected into a space or potential space somewhere within the body. The device
and the
method of use thereof is not limited to use in humans. Indeed, the device
could find
applications in numerous unrelated faelds where precise penetration of
embedded spaces is
desired.
DISCUSSION OF THE BACKGROUND
Most existing trocars or insufflation needles used for endoscopic surgical
procedures
are incapable of truly effective prevention of injuries to internal organs
during insertion and
manipulation of the trocar. Despite intensive efforts to improve present
trocar designs, the
results are still dismal. Present procedures frequently injure internal
organs, and the resulting
wounds are sometimes serious or even fatal. The need for safer trocars and
insufflation
needles is thus imperative, especially given that endoscopic surgical
procedures are likely to
become more widespread in the future.
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Endoscopic or minimally invasive surgery presents an opportunity to improve
present
surgical procedures and instrumentation comparable only to the revolutionary
effect of the
introduction of anesthetics in the 19th Century.
Most present day trocars utilize a tip "shield", or cover, for the cutting
edges which is
usually deployed immediately after penetration of the body cavity has taken
place. Such a
penetration is fraught with danger of injury to internal organs. However
careful a surgeon
may be during penetration of the body cavity, the resistance to penetration
drops at the last
instant prior to damage to the internal organs. This sudden drop in the
resistance to
penetration is called a "plunge effect" and occurs prior to any safety feature
deployment. In
some trocars, the penetration is controlled in some fashion, either taking
place in small
increments or under some form of approximate direct observation, estimate, or
monitoring. In
all cases, however, the designs result in much of the piercing tip being
inserted to a dangerous
depth before any protecting devices is deployed. This is perhaps not
surprising since, after all,
a hole must be made before any protection is deployed.
Since in most cases delicate organs are very close to the inside of the skin
layer being
pierced, it is advisable to perform the penetration after internal cavities
have been filled with
carbon dioxide to minimize the danger of accidental injury due to contact with
the sharp
piercing tip or the cutting edges of the instrument. In most cases, however,
the force required
for penetration and the elastic nature of the muscular layer cause a severe
depression at the
surgical portal, therefore bringing the penetrating tip of the instrument
closer to the internal
organs. In some of those cases, the sudden penetration of the cavity wall and
the rapid drop in
resistance allow the instrument to be propelled far deeper than desired or is
possible control.
Furthermore, friction between the tissue walls and any protective device
retards the
deployment of the protective device, and an injury almost inevitably occurs.
Accordingly, one object of this invention was to insure that such events be
avoided
through a surgical device in which a penetrating tip or cutting edges) of the
instrument be
kept, at all times, sufficiently distant from delicate tissues. Thus, even
under dynamic
conditions, the probability of injury will be reduced. As mentioned in IJ.S.
Patent 6,497,657
invented by the inventor of the present application, most existing trocars
used for endoscopic
surgical procedures are incapable of truly effective prevention of injuries to
internal organs
during insertion and manipulation of the trocar. Despite intensive efforts to
improve present
trocar design the results are still dismal. Present procedures frequently
injure internal organs,
and the resulting wounds are sometimes serious or even fatal. The need for
safer trocars is
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thus imperative, especially given that endoscopic surgical procedures are
likely to become
more widespread in the future.
SUMMARY OF THE INVENTION
Accordingly, one object of this invention is to insure that such events be
avoided
through a surgical device in the form of a trocar or insufflation needle in
which a penetrating
tip or cutting edges) of the instrument be kept, at all times, sufficiently
distant from delicate
tissues. Thus, even under dynamic conditions, the probability of injury will
be reduced.
A further object of this invention is to provide a surgical device (trocar,
insufflation
needle or structurally equivalent device) wherein insufflation fluid can be
driven into a
patient during penetration of the body cavity by the surgical device to drive
the internal
organs away from the surgical device during penetration. The insufflation
fluid of the present
invention can either be supplied from an external pressurized reservoir, or
compressed (and
hence gathered) during penetration of the body cavity by the surgical device.
A further object of the invention is to provide a surgical trocar or
insufflation needle
that contains one or more cutting edge that provides low frictional forces
between the cutting
edge and tissue during penetration of the body eavity, thus reducing the force
needed to drive
the surgical device into the body cavity.
A further object of the invention is to provide a surgical device that
includes a
protective device that deploys while remaining substantially out of contact
with tissue, thus
reducing frictional forces between the protective device and ensuring a
controlled and
advantageous deployment.
A further object of the invention is to provide a surgical device that
includes a
protective device such as safety guards, wherein he guarding elements have an
apex and the
angle subscribed at the apex is smaller than the angle subscribed by the
blades or cutting
elements of the surgical device, thus insuring progressive coverage of the
blades or cutting
elements during deployment of the protective device.
A yet further object of this invention is to provide a surgical device with a
grip
mechanism that allows convenient gripping and twisting of the surgical device
during
penetration of the body cavity.
An additional object of this invention is to provide a surgical device that
includes a
locking system that prevents accidental reuse of he cutting elements after the
tip has been
used.
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It is therefor desired that this invention, in general, improve surgical
safety.
These and other objects of the invention are achieved by a surgical device
such as a
trocar tissue penetrator or insufflation, bladed needle including a set of
thin planar arrow-
pointed cutting blades joined at a cutting point coaxial and within a hollow
cylinder
penetrator and having the cutting edges converge at a cutting angle at the
cutting point. A
single flat blade can also be used if desired. The back outside of the set of
cutting blades can
be fixed o the inside of the hollow cylinder penetrator with the cutting edges
fully protruding.
The hollow cylinder can have its front end slotted and each segment pointed in
a triangular
shape and bent to fit between the blades and having its edges substantially
parallel to the
edges of the protruding blades but axially recessed behind such edges to act
as a tissue
expander to prevent contact between inside moving guards and the outside
tissue. The slots
between the triangularly shaped bent section tissue expanders at the end of
the hollow
cylinder penetrator can be wide enough to permit the passing between them and
the sides of
the cutting blades of a guard sheet at least as thick as the blades. One or
more elongated
axially bent sheet guards can be set to slide freely within the space between
the sides of the
cutting blades and the triangular bent segment of the hollow cylinder and
having their frontal
end with a tip angle profile substantially more acute than the adjacent angle
of the blade
edges and terminating in a very small dull round tip. The angular frontal
edges of the bent
sheet guards can have shallow angle ends and curving slowly toward the edges
so that at no
time their angle exceeds that of the adjacent cutting edges. The elongated
bent sheet guards
inserted between the cutting blades and the triangularly bent segments of the
hollow cylinder
can be attached at their opposite end to a stem which is urged toward the
frontal cutting edges
by a coil spring.
The advantageous characteristics of this surgical device include, e.g., the
following:
a multiple system of sharp planar knife edges that practically eliminate
lateral friction
and provide a reduced resistance to penetration, thereby reducing the
penetration "plunge
effect" and tissue springback.
a mechanical tissue protection device that includes a series of thin plastic
guards
sliding along the sides of the planar knives and, in a preferred embodiment,
having an angle
between their edges smaller than that of the cutting knife edges. It can then
be shown that,
with proper contouring of such plastic guard edges, it is possible to provide
complete
guarding between the cutting edges and the surrounding tissues from the very
start of the
penetration, and to do so in a truly progressive manner, without jerks or
discontinuities. The
progressive guarding action that results from the smaller angle between the
sides of the
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guards than the angle between the edges of the cutting blades allows the
guards to plunge into
the tiny opening made by the cutting tip and instantly surround it, thereby
preventing injury
to internal organs during the most crucial instant of the trocar insertion.
Therefore, guarding
action takes place in a truly progressive manner in which, as the cutting
lades continue
expanding the tiny initial opening, the guards progressively advance keeping
the cutting
edges constantly covered outside the penetrating region and isolated from
internal organs
until the penetration is completed and the cannula fully inserted;
one or more fixed conical deflectors to expand the cut tissue passage leaving
the
guards to contact tissue only at their tips, thus isolating the guards from
friction against the
tissue at the sides of the point of penetration. Therefore, as soon as even a
minute opening is
made at the tip by the cutting blades, the guards instantly plunge into the
opening and prevent
the blade tip from any contact with internal organs. Thus, using tissue
expanders outside the
guards prevents friction between the guards and the tissue, which would retard
the
deployment action. The use of this tissue expander allows the safety device to
function
without restriction, thereby eliminating one of the major deficiencies of
existing trocars. In
other words, the dynamic response of the guards is inherently much faster than
the rate of
penetration of the blades. As a result, cutting edges are never dangerously
exposed t~, contact
with internal organs, however fast the penetration rate may be; an
insufflation passage
configured to transport fluid into the body cavity during penetration. The
insufflation passage
can be pressurized either using an external reservoir or by compressing gas
contained in the
passage during penetration. ~nce an initial penetration of the epithelium has
been made, fluid
from the insufflation passage will drive the internal organs away from the
cutting edge(s). In
the case of an external carbon dioxide gas reservoir, a carbon dioxide gas
valve is opened,
hereby pressurizing the penetrator tubular body. Under such pressurization,
since the front is
enclosed by tissue, the cutting tip penetrates the tissues while the gas is
prevented from
exhausting, but as soon as the most minute opening starts to appear at the
tip, the gas expands
suddenly into the opening and forcibly deflects delicate internal organs away
from the tip of
the cutting surface while simultaneously the guard tips are forced through the
opening by
their spring. The use of a pressurized fluid (or gas) tissue deflector thus
creates an organ-free
zone in front of the.cutting blade tips at the instant o the incipient
penetration, even before the
guard tips plunge into the opening. It must also be pointed out that a sudden
as expansion can
also aid the deployment of the guards since the flow occurs between the
cutting blades and
the conical expanders, precisely where guards may be located. It could almost
be said that the
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guards are spit out by the fluid flow. This increases the velocity of their
deployment and
hence the overall safety of the surgical device;
a locking system for the guards, which is located at the proximal end of the
instrument, prevents accidental reuse of the cutting features after the tip
has been safely
introduced for the first time. The locking system for the trocar guards
includes a locking
cylinder attached to a locking button supported by a leaf spring and inserted
into a socket.
The cylinder has a conical tip and a circumferential groove at the bottom and
can be
depressed by way of the button and engaged by the groove into a U shaped
spring that will
hold it down permitting it sliding motion until it comes out of the U shaped
spring and is
ready for locking again on its return to the initial position. If a reset
action is desired it is
necessary to push hard downward against the locking button and deliberately
reset it for
another cycle. Since the locking button is located deep within a recess at the
proximal section
of the handle, it demands some effort to reach and actuate, and thus it is
difficult to
accidentally reset.
an ergonomic design which facilitates handling. The proximal hemispherical
knob
nestles easily into the hollow of the hand while the index and middle fingers
control rotation
by gripping the side home, thereby permitting push, pull, rotation, and
tilting in a very natural
and comfortable manner.
The surgical device having the above-noted characteristics can thus comprise a
trocar,
an insufflation needle or any other surgical/penetration device having a
similar function.
The insufflator in accordance with one embodiment of the present invention
comprises a needle-like device through which a gas or other fluid can be
injected into a space
or potential space somewhere within the body of a patient. The device is not
limited to use in
humans. Indeed, the devise could find applications in numerous unrelated
fields for precise
penetration of embedded spaces is desired.
Referring now to the drawings, wherein like reference numerals designate
identical or
corresponding parts throughout the several views, and more particularly to
FIG. 1 thereof,
wherein a cannula 2 corresponding to the background of the invention is firmly
attached to a
distal section of a handle which is formed from two segments, the distal one 6
externally
containing gripping horns 6a, insufflation device 11, and flap valve lever 12,
and a proximal
handle section 5 in the shape of a hemispherical knob to facilitate its
pushing with the palm
of the hand. This section also contains a depression 9 with a flat bottom 9a,
and external
mechanisms including a button 7 inserted for sliding into a slot 8 to monitor
and control the
position of safety guards at the extreme distal en of cannula 2. The safety
mechanisms
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protruding distally from cannula 2 include conical tissue expanders 4, and
safety guards 3
intended to cover a set of knives (not visible in this FIG. 1). Those are the
externally visible
features of this invention.
FIG. 2 shows details at the penetrating distal end of the trocar. A hollow
outside
cylinder 2 is the cannula which is firmly attached to the distal section of
the handle 6 as was
described in FIG. 1. Inside of the cannula 2, there is another hollow cylinder
13 which is the
penetrator. This is the removable part which is attached to the proximal
section of the handle
5, and can be removed after the penetration is completed to allow for the
introduction of
surgical instruments. The cannula 2 has its distal end beveled as shown by 2a
to facilitate its
introduction across the tissue opening with minimal resistance. The penetrator
hollow
cylinder 13 has its distal end formed as a plurality of conical segment
expanders 4 which are
spaced by slots 4a to allow for the protrusion of pointed flat knives 14
joined at the center of
the instrument and resembling thin arrowheads joined at a center. As shown in
FIG. 2, the
knives are positioned into the penetrator hollow cylinder 13 to a depth shown
at 14a. The
knife edges outside the slots 4a betyveen the conical segment expanders
protrude a substantial
distance to insure adequate cutting. The set of knives is assembled into the
penetrator cylinder
13 by spot welds 15, or by other similar mechanism. Right behind the cr~ssing
of the knife
blades can be seen the plastic guard tips 3a. In FIG. 2, the guards are shown
as removed from
the knives so as to facilitate the understanding of their shapes and relations
.lip to the knives.
The subassembly of the guards 3 is part of a support disk 16 which in turn is
part of the
guards hollow stem 17 connecting them to an actuator spring and locking
mechanism at the
proximal section of the handle (not shown here). In the real instrument, the
guard tips 3a are
inserted around the knife blades which fit into the narrow spaces 3b between
the guards. The
guards are then assembled by being pushed forward until they protrude between
the blade
sides and the conical expander slots 4a as can be shown in FIG. 3 below. Tn
FIG. 3, the tips of
the guards are barely visible because the guards are retracted as when the
trocar is first
pushed against the skin.
FIG. 4 shows the tips of the guards 3a protruding ahead of the tip of the
knives and
covering them. A short distance behind the tips of the guards 3a the edges of
the knives 14
are exposed and capable of cutting. FIG. 4 shows the configuration of the
trocar cutting tip
right after initiation of the penetration across the abdominal tissue. At that
instant, the guard's
tiny tips 3a plunge across the start of the opening and quickly cover the
sharp cutting point
while the exposed knife edges continue cutting inside the skin until the
penetration is
complete as shown in FIG. 5. FIG. 5 shows how the front end of the example
trocar looks
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after the penetration into the abdominal cavity has been completed. At that
time all edges of
the cutting knives are covered by the fully extended guards and the whole
penetrator
assembly can be pulled out with the proximal sector of the handle.
As will be shown later, in one embodiment, at the instant when the first
perforation of
the abdominal wall was made, a forceful jet of carbon dioxide gas issued
across the
perforation to deflect away any delicate organs close to the knives tip while
simultaneously
the guard tips entered the opening to cover the point of the knife edges. The
operations just
described above are a critical part of this invention, therefore they will
best be described
through the sequence of figures from FIG. 6 through to FIG. 11. It is noted,
however, that the
present invention can function without insufflation occurring since the blade
is guarded.
FIG. 6 represents the example trocar guard tips 3a as they begin to contact
the skin
layer 20. The internal organs are shown at the left side as 25. At this
instant, the skin outside
layer is deflected under the force of the guard tips which are urged forward
by their spring.
As the trocar is pushed forward, the guards will be forced into the penetrator
13 and displace
the base disk 16 and guard stem 17 toward the right against the force of their
spring.
FIG. 7 shows the guards 3 already completely retracted into the penetrator 13,
and the
knife edges 14 completely exposed. At that instant, the point of the knives
begins fio cut and
penetrate at 21 into the outside tissue layer. As shown in FIG. 7, the cutting
pathway of the
cutting tip/knife edge is of a smaller diameter than the inner diameter of the
cannula 2 such
that the cutting bade by the blade results in a smaller lumen or bore than
that of the cannula.
lit that time, the carbon dioxide gas is allowed to pressurise the inside of
the penetrator 13,
and while some gas may escape at first, the tissues around the tip will seal
the flow until the
cutting tip starts to emerge across the internal abdominal wall.
FIG. 8 shows the onset of penetration. At that instant, the cutting tip point
14b has
made a very minute perforation 23 and, because of the presence of the guard
tips 3a, there is
enough space to allow a fluid flow (shown here as a gas jet 24) to issue out
and cause the
displacement of nearby internal organ tissues 25a, while simultaneously the
guard tips 3a
expand the opening urged by their spring pushing at 17 and plunge through the
perforation
effectively covering the cutting tip 14b.
FIG. 9 shows the result of the action described above. The gas jet 24
continues issuing
and driving internal organs 25a farther away while the guard tips 3a
completely enclose the
cutting tip 14b. All danger to internal issues has passed. The extremely quick
flow of the gas
and the action of the guard tips make the manipulation factors of this trocar
the safest to
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master easily. The force or speed of the penetration action are, within
reason, almost
immaterial.
FIG. 10 shows the penetration process. The cannula 2 is partly introduced
across the
tissue 27 and the guard tips 3a continue advancing and protecting the internal
tissues from the
knife edges while the portions of the edges not yet covered by the guards 14a
are seen cutting
the remainder of the opening ahead of the cannula, and the tissue expanders 4
facilitate
penetration by protecting the guards from tissue friction. At this point of
the penetration the
flow of carbon dioxide gas 24 is fairly unimpeded and performs the
insufflation stage of the
process, driving internal organs 25a farther away from the trocar portal.
FIG. 11 shows the trocar after full insertion and in the last stage of
insufflation. The
knife edges are now fully covered by the guards, and the cannula 2 is seen
fully inserted
across the tissue. The insufflation continues until completed and then the
penetrator 13 is
removed to allow the insertion of surgical instruments across the cannula.
Having described in sequential detail the insertion, guarding, and
insufflation
operations, and the mechanical parts that perform them, it remains to describe
the additional
way by which all that is accomplished. The mechanisms that allow this are
located in the
handle of the instrument.
FIG. 12 is a top view of the trocar showing some of the external parts as well
as a
partial broken view of some interior parts. The body of the handle is made out
of plastic and
has two main segments. The proximal segment 5 is designated to fit into the
palm of the hand
and has a proximal end of hemispherical shape with a depression of arcuate
profile 9 at the
top terminating at a flat surface 9a ~vhere the guard stem controls are
located. Those controls
are recessed into the flat depression 9a to prevent unwanted actuation, and
include a double
slot with vertical slots ~ and ~a into which is inserted a button 7 and its
rectangular guiding
shank 7a. The button 7 is capable of vertical and horizontal movement, the
latter movement
being limited between arrows 7b and 7c as will be described later. The
proximal segment 5 is
assembled as an integral part of the penetrator system. Its distal end 51
forms the interface
between the two segments of the handle.
The distal segment 6 of the handle has two lateral protruding horns 6b to
facilitate its
manipulation during penetration and orientation. The two handle segments 5 and
6 are locked
together during usage by way of a bayonet stud 29 and slot 29a. During
insertion the stud 29
on part 5 is aligned with the slot 29a on part 6, pushed, and turned
clockwise, until the stud
locks the two segments firmly, the knob on 5 and the horns 6b provide a good
grasp for that
operation. The slot 29a is slanted in the transversal direction running
slightly away from the
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interface 51 so as to insure that the turning-locking motion will assure a
firm and stable
connection. This will be discussed further in reference to FIG. 14.
The partial broken section at the top left of the distal segment 6 is intended
to show
the operation of the flap valve 32, which acts as a check valve in the
illustrated embodiment.
The valve has a shaft 34 pivoted between the upper 6 and lower 6a portions of
the handle and
is urged to rotate counterclockwise by a torsional spring 33 located around
the shaft 34. The
shaft of the flap valve is firmly attached to the valve and can be rotated
from outside the body
segment 6 as will be shown later on FIG. 14. An external lock allows the valve
to remain
open during desufflation if turned hard to its stop position 32a shown in
dotted lines. As
shown in the embodiment illustrated in FIG. 12, the valve has been opened by
the insertion of
the penetrator 13. In other cases, the valve could be opened for surgical or
visualization
instruments. When left to itself the valve will turn counterclockwise and snap
shut against the
face of seal 35 which serves as face seal for the valve and lip seal for the
penetrator 13. The
left end of FIG. 12 shows how the cannula 2 is attached to the handle segment
6 by way of a
flange 37, and prevented from leaking by an "O" ring 36. In the same FIG. 12
is shown how
the carbon dioxide gas spigot manual valve 11 is mounted at one side of the
t~p of segment 6.
FIG. 13 s a longitudinal vertical cr~ss section along a plane "A--A" to show
the
internal details of the handle. As can be noticed, he two segments of the
handle include a top
and a bottom part split along a horizontal plane for fabrication, one becoming
5 and Sa, and
the other 6 and 6a, and after each segment has been fitted with the internal
parts at assembly
the two hales of each segment are permanently bonded together. Each of the two
segments is
assembled separately since they must be detaclaed and attached during usage.
The penetrator
segment is only used t~ make the entry portal, but it must be emphasized that
it is such step
that involves the greatest risk.
The distal segment made of parts 6 and 6a houses the cannula 2 and all the gas
infusion and valuing. The connection of the cannula to the segment part 6 was
described
before. FIG. 13 shows the gas connector or layer l la to which the gas line is
a fixed. The
valve system is bonded via a conical stem 1 1b into a boss on plane 10 so the
incoming gas
flows in the direction of arrow 30 and pressurizes the space between the inlet
and the seal 35
from where it can enter the openings 3~ around tile penetrator 13 walls and
fill the space
between lip seals 40 and 41. Since the lip seals are oriented toward the front
the pressure will
open lip seal 40 but not lip seal 41 and the gas will fill and pressurize the
entire space along
the penetrator 13, not being able to escape when the trocar tip has been
inserted into the
tissue, however, as soon as the smallest opening is made by the point of the
blades the gas
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will escape as a jet and deflect the surrounding internal organs away from the
entry portal.
Lip seal 40 is intended to prevent back flow from the penetrator in case of
accidental opening
or leakage across the gas valve during a procedure. In such a case, the
pressurized volume of
gas within the penetrator 13 will suffice to insure the safe deflection of
nearby tissues even
before the tips of the guards 3a plunge into the opening. The guards stem 17
is completely
sealed at the front by disk 16 and thereby its interior can be at atmospheric
pressure.
However, since it must slide back and forth with the guards it must also be
supported at the
proximal end and must be guided over a stationary hollow steel stud 44
inserted into it to a
minimal depth of four diameters. The proximal end of stud 44 is flared to
provide fixation
between parts 5 and Sa of the proximal hemispherical knob. A hole 56 on the
hollow stud 44
serves to provide air passage in and out of the stud when the guards stem
moves back and
forth acting as a piston pump. The hole 56 should pass through the stud and be
of a diameter
such as not to impede flow and dampen the sliding action of the guards' stem.
Compression
coil spring 47 mounted around stud 44 serves to provide the required force to
urge the guards
stem in the distal direction. The proximal end of the penetrator outside
cylinder 13 is flared at
43 for fixation onto the proximal handle segment parts 5 and Sa. It is also
sealed at the front
by an "~" ring 42 to insure that no leakage of gas would occur even if seal 35
should leak:
flared tubular assemblies like 43 are not reliable seals.
The proximal handle segment formed by parts 5 and Sa is attached to the
penetrator
13 and contains all its functional and control elements. The guards stem 17
has at its proximal
end a shallow cylindrical depression int~ which a thin ring 4.5a which is part
of leaf spring 45
is affixed. The exact configuration of the locking system to which the spring
45 belongs can
be seen in FIGS. 16 and 17, and its function in the sequence of FIGS. 18
through 22. FIG. 17
is an exploded view of some of the elements of the locking system in their
proper
relationship. At assembly, the button 7 is inserted across slot 8 on the top
surface 9a on FIG.
13 and the locking cylinder 48, which has a circumferential groove 48a and a
conical end 48c
is pushed up along the stem 7b against the bottom of the rectangular guide 7a
thereby
assembling button 7 into the slot 8a. As the assembly continues the lower tip
of stem 7b is
pushed hard against the punched hole 45d of the leaf spring until grove 7c is
gripped by the
lateral tabs at 45d and the assembly of the button is complete. If now the
open hollow
cylinder 45a is snapped onto the surface depression at the proximal end of
stem 17, the button
7 becomes axially fixed to stem 17 and will follow its back and forth motion
in response to
coil spring 47 and the forces at the tip of the guards. FIG. 16 shows the
assembly of the IJ
spring 46 to the lower inside of 5 by the use of screw 50. FIG. 16 does not
show button 7 for
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the sake of clarity, but it shows flat spring 45 pushing up against the bottom
of the U spring
46. If the assembly of the button 7 and the locking cylinder 48 was shown
there, it would be
evident that the button would be pushed upwards and the locking cylinder 48
would be
forcibly inserted into the round socket 8b, thereby preventing any motion of
the flat spring 45
and the guards stem 17 attached to it by ring 45a. That is the situation
depicted on FIG. 13.
FIGS. 18 through 22 describe an operation of an example locking system in
detail, as
follows. In the position illustrated in FIG. 18, the system is locked. The
guards stem and the
guards cannot move at all since the cylinder 48 is inserted into the round
socket 8b. FIG. 19
shows what happens when button 7 is pushed down. When that is done the conical
end 48c of
cylinder 48 opens the U spring 46 and the spring then snaps close into the
groove 48a thereby
disengaging the locking cylinder from the round socket 8b. The system is then
unlocked. The
trocar is said to be "armed", and able to permit the motion of the guards
backwards, exposing
the cutting blades for penetration of the skin. That is the position depicted
on FIG. 6. The
following discussion is directed to the embodiment shown in FIG. 20. The
penetrating force
against the skin pushes on the guards and the guards stem 17, and the
connecting flat spring
45 moves the button 7 proximally. The rectangular slide section 7a enters the
space between
guides 8a, and soon afterwards, the locking cylinder groove 48a disengages
from the open
end of the U spring 46, and the spring 45 pushing upwards against the stem
groove 7c forces
the top of the locking cylinder to snap against the underside of the groove
8a. In that position,
the locking cylinder 48 is free to continue sliding along the underside of
groove 8a as shown
in FIG. 21 until the initial penetration is made and the force ~f the coil
spring 47 urges the
guards stern 17 and the flat spring 45 to return the button 7 t~ its initial
position, at which
time the locking cylinder will pass freely over the U spring 46 and snap back
into the round
socket 8b locking the system into the "safe position" where the guards cannot
move
accidentally. FIG. 22 shows the completion of the cycle back to the initial
configuration of
FIG. 18.
A quick review of the provided example locking system from the user viewpoint
reveals that the operations include "arming" the trocar by pushing down on the
button at the
top of the handle at position 7' shown in FIG. 12, until it "snaps" down; then
pushing the
trocar against the skin and watching or listening to the position of the
button as it slides
towards 7' and then "snaps" to its initial position 7'. That will be the
indication of having
completed the penetration. If, for any reason, button 7 were pushed down
accidentally, it
could be reset to the "safe" condition by merely moving it in the direction to
T and then
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WO 2004/080274 PCT/US2004/003370
releasing it. It should then get snap-locked at a high level in position 7'~
and could not be
moved without first pushing it down.
The details of operation of the example flap valve, its design, and locking
for
deflation are seen in FIGS. 14 and 15. FIG. 14 show the top view of the handle
distal
segment, previously presented in FIG. 12 as a partial broken section to show
the inter or
details. FIG. 14, however, is intended to show the external operative controls
on this segment
of the handle in the interest of the user. The flap valve lever 12 is shown in
the closed
position as it should be when the penetrator is removed. The lever is attached
to a shaft 34
whose opposite end is attached to the flap 32 as seen in FIG. 15. The
insertion of the internal
trocar elements is performed when the top 6 and bottom 6a of each handle
segment are
separated prior to their being bonded along plane 6d.
FIG. 15, as explained before, is the end view of the example embodiment
previously
illustrated in FIG. 14 as seen from the right side. That is how the distal
segment of the handle
will appear when the proximal segment is removed. The flap valve external
lever knob 53 is
provided with a small depression 54 at its bottom to allow it to be held ogen
when the
depression is forcibly made to engage a small knob 54a protruding from the
flat surface 10
after the lever has been turned in the direction of arrow 52. That is the
desufflation position of
the valve which allows the surgeon to use both hands to massage the
insufflated region and
expel the gas retained by the patient at the end of the procedure. The arc of
rotation needed
for the lever to engage the protruding knob 54a is labeled as 55. This locking
position is not
reached by the lever when the valve is opened by the insertion of the
penetrator. The locking
of the valve has to be done by the forceful and deliberate action of the
surgeon. The small
angle 52 shown at the bayonet locking stud 29 refers to the desirable slant
for the groove 29
so as to insure that the locking force increases sufficiently to prevent
accidental loosening
between the proximal and the distal segments of the handle. The elasticity of
the locking
elements determines the exact angle to be used, which should be somewhere
between 2 and S
degrees to account for tolerance errors. The infusion valve 11, its lever l
lc, and its lever
connector 11 a are shown on FIG. 14. In FIG. 15, the opening of the valve is
indicated by
arrow 1 1d. FIG. 15 also shows a broken section of the valve shaft 34, its top
"O" ring seal
34a, and its torsion spring 33 inserted into a slot in he operating bracket of
valve 32. In the
same FIG. 15, the seal 35 is seen, as well as the front surface S l a of the
distal handle
segment, which contacts the mating surface 51 of the proximal segment.
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BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant
advantages
thereof will be readily obtained as the same becomes better understood by
reference to the
following detailed description when considered in connection with the
accompanying
drawings, wherein:
FIG. 1 shows a general view of the trocar described in the background of the
invention in isometric pictorial form;
FIG. 2 illustrates a partial broken view of the penetrating end of the example
trocar
with guards removed to behind the tip knives to illustrate a shape of this
embodiment more
clearly;
FIG. 3 shows the same end of the example trocar with the guards installed but
retracted as when penetration of an example embodiment starts, and thus, the
knife edges are
exposed and ready to start cutting;
FIG. 4 shows the tip of the guards protruding ahead of the cutting tip as when
the tip
had just started to pierce the abdominal cavity;
FIG. 5 shows the tip of the example trocar with the guards fully extended and
covering the knife edges as when completely inside of the abdominal cavity;
FIG. 6 shows the example trocar tip at the moment it approaches the skin
layer, and
thus the guard tips are beginning to push against the skin and be retracted
into the penetrator;
FIG. 7 illustrates the point when, in an example embodiment, the guards are
completely pushed into the retracted position and the knife tips start to cut
into the tissue;
FIG. 8 illustrates tlae point when, in an example embodin~aent, the knife tips
have
completed the passage across the tissue and begins to emerge across the
endothelial layer into
the abdominal cavity, and thus the tips of the guards begin to push into the
incipient opening
while a forceful jet of pressurized carbon dioxide gas pushes delicate
internal tissues away
from the immediate penetration region;
FIG. 9 illustrates the point when, in an example embodiment, the tips of the
guards
have penetrated the opening and prevent any contact between the knife tips and
the
surrounding internal tissues while the exposed knife edges behind the opening
continue the
cutting action, and the pressurized carbon dioxide gas expansion continues to
hold delicate
tissues away from the cutting region;
FIG. 10 illustrates, in an example embodiment, the continuing penetration, and
thus
the guards have penetrated almost completely, while behind them the still-
exposed edges
continue the cutting action and the passage of gas continues;
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FIG. 11 illustrates the point in an example embodiment when the penetration
has been
completed. The knife edges are fully covered by the guards and the tissue
opening allows for
the passage of the cannula and the insufflation continues until completed and
the penetrator
assembly can be removed;
FIG. 12 shows the top view of an example trocar handle with a portion broken
away
to show some internal details;
FIG. 13 illustrates a longitudinal section along the horizontal plane 13-13 in
FIG. 12
to exhibit most of the internal details of an example trocar handle;
FIG. 14 illustrates a top view of the distal section of an example handle with
the
grasping horns to facilitate manipulation;
FIG. 15 illustrates an end view of the distal section of an example handle as
seen from
the right showing also a partial broken section detail of the flap valve pivot
and lever;
FIG. 16 illustrates a partial~isometric view of the example locking mechanism
for the
guards stem showing some of the element within the proximal section of the
handle;
FIG. 17 illustrates an exploded view of some of the example elements of the
guards
stem locking mechanism in an example spatial relationship;
FIG. 18 illustrates an example locking mechanism in a locked position;
FIG. 19 illustrates an example locking mechanism having been unlocked and
ready
for the start of penetration;
FIG. 20 illustrates how pushing the guards against the skin has forced their
stem
towards the right;
FIG. 21 illustrates a position of the stem where the guards are completely
retracted
and the knife edges fully exposed for cutting;
FIG. 22 illustrates a position of the locking mechanism after the full release
of the
guards into the abdominal cavity and the locking of their stem back to its
initial position
shown in FIG. 18.
FIG. 23 is a top plan view of a guard for the insufflator of the present
invention;
FIG. 24 is a top plan view partially in cross section of the cutting blade top
portion of
the insufflator;
FIG. 25 is a side elevational view of the cutting blade tip portion shown in
FIG. 23;
FIG. 26 is a top plan view of the tip portion of the guard;
FIG. 27 is a side elevational view of the tip portion of the guard;
FIG. 28a is a top plan view of the assembled distal tip shown when the guard
is
initially in contact with the skin;
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WO 2004/080274 PCT/US2004/003370
FIG. 28b is a top plan view of the assembled distal tip when pressed against
the skin;
FIG. 28c is a top plan view showing the device when penetrating tissue layers
of the
abdominal wall (for example);
FIG. 28d is a top plan view showing the device in an early stage of
penetration of a
final tissue layer of the abdominal wall with an option of gas/fluid provided
at the moment of
perforation;
FIG. 28e is a top plan view showing the distal tip in an extended position of
the guard
after puncture of the contiguous tissue layers.
FIG. 29 is a partial cross sectional view of the locking mechanism utilized in
accordance with the present invention.
FIG. 30 is a cross-sectional view of FIG. 29.
FIG. 31 is an enlarged side elevational view of a portion of FIG. 29.
FIG. 32 is a top plan view of the lock mechanism shown in FIG. 29 with the
lock
mechanism removed.
FIG. 33 shows a side view of an additional embodiment of the invention in
cross
sectional.
FIG. 34 shows a top plan view of the sliding inner guard of the embodiment of
FIG.
33.
FIG. 35 shows a side elevational view of the sliding inner guard tip.
FIG. 36 is a side axial view of the assembled additional embodiment.
FIG. 37 illustrates a further embodiment of the present invention.
FIG. 38 shows the distal end of the sleeve of the third embodiment, including
the
blade.
FIG. 39 discloses a top plan view of the distal end of the sleeve having a
tapered
flange.
FIG. 40 is a top plan view showing the guard when in position in the sleeve;
FIG. 41 shows a side view of an additional embodiment of the present
invention; and
FIG. 42 shows a side view of the cannula and blade thereof.
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DESCRIPTION OF THE PREFERRED EMBODIMENTS
In one embodiment, fluid is delivered into and through the device from an
appropriate
tubing or syringe via a Luer lock coupler 101 and is flow controlled with a
simple stopcock
mechanism 102, both items being common and well-known in the industry.
The outer body of the device is a hollow cylinder 104 (possibly made of
surgical
steel) and which is contemplated as being of a diameter of 1.0 - 4.0 mm in the
preferred
embodiment, to which is fixed a distal cutting blade 104a. Within the outer
body cylinder
resides a coaxial sliding spring-loaded cylinder 105 with a blunt blade guard
l OSd fashioned
distally. The proximal extent of the sliding blade guard is compressed with a
spring
mechanism comprised of a fixed proximal block 103a attached to the outer body,
an
appropriate gauge spring 103b, and an attachment 103c to the sliding guard
lOSa. The block
103a has a central opening formed therein for passage of the fluid
therethrough. The spring
mechanism may additionally contain a locking mechanism that prevents
retraction of a
sliding guard after the guard fully protrudes distally (i.e., after tip
penetration of the desired
space).
The distal cutting end of the outer guard is comprised of a thin pointed fixed
blade
104a across the open end of the distal cylinder, fixed at position 104f.
Lateral to the flat
aspect of the cutting blade 104x, the cylinder walls 107 slant proximally away
and terminate
in a beveled edge 104b to facilitate penetration. The blade 104b has a
centrally located
opening 104b to facilitate flow of fluid through this region of the
insufflator and into the tip
and primary exit ports 105b. The angle 104.c subtended by the opposing blade
edges is
defined as ~blade. The angle 104e subtended by the imaginary line from the
blade tip to the
inner exposed edge of the outer cylinder perpendicular to the plane of the
blade is defined as
~tip.
The sliding inner guard mechanism 105 has a substantially conical tip l OS and
an
open lumen l OSa that extends distally past the paired primary exit ports
105b. The distal
lumen of the inner guard mechanism may be hollowed out in such a way as to
maximize fluid
flow through the tip of the device, and is not restricted to the specific
internal shape portrayed
by reference numeral l OSa. Perpendicular to the exit ports is a slit l OSc
that is just wide
enough to accommodate the cutting blade 104a. The slit l OSc is extended
proximally to a
position l OSf far enough to allow distal deployment of the guard over the
blade cutting
surfaces and the guard has a blunt tip l OSd as shown. The angle lOSe
subtended by the
tapered edges of the distal blade guard in the plane of the cutting blade is
defined as 6shield .
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WO 2004/080274 PCT/US2004/003370
The propel functioning of the shield requires that Bshield be less than
Bblade. The angle l OSg
subtended by the distal tapering guard edges perpendicular to the plane of the
blade is defined
as Btip. The angles 104e and l OSg should be approximately equal.
The insufflator is constructed, and the spring compression is adjusted, so as
to allow
the sliding blade guard to retract proximally and expose the distal cutting
blade when pressed
against the skin or outer surface of the area to be penetrated (Figs. 28a,
28b). At the moment
the point of the device penetrates a (potential) space, the distal blunt tip
of the guard advances
beyond the sharp tip of the blade and a puff of fluid discharges from the
distal tip of the
instrument (Fig. 28d). As penetration of the space is completed, the sliding
blade guard
continues to advance over the blade and the device appears as shown in Fig.
28e. The
primary fluid exit ports are thus fully exposed and maximum outflow can
proceed. Further
distal protrusion of the sliding guard is prevented by contact of the most
proximal aspect of
the guard slit Sc coming into contact with the most proximal aspect of the
blunt side of the
cutting blade.
The blade 104c has features similar to the blade utilized in the above-noted
patent
publication and patent application and thus can include a slightly rounded or
blunt tip and
also has a guard and blade apex relationship as described therein.
The guard lock mechanism (Figures 29-32) here is constructed from paired,
bilateral
lever arms 207a which are textured to allow firm digital grip. A device with
one or more
levers and receiver slots is also possible. Axial compression of the spring-
loaded lever arms
allows disengagement of the locking pegs 207c, whereas pressure on the rnore
perpendicular,
distal lever arms allows the needle to be pushed into the desired space. The
levers are
anchored via hinges 207b at the lever fulcrum. The lever pegs 207c are
compressed into
corresponding holes in the outer sleeve 204 and corresponding receiver grooves
207d in the
sliding inner guard 205. The peg ends are rounded and designed to slide within
the receiver
grooves with a minimal amount of friction. The area of the lever arm around
the peg is
contoured to tightly fit the surrounding outside surfaces of the outer sleeve
so as to seal the
holes and prevent escape or ingress of fluids through the bilateral defects.
The lever pegs
207c are curved to the radius of the fulcrum to allow smooth passage of the
pegs through the
holes and receiver grooves.
The receiver grooves 207d (Figures 31,32) are slanted (deeper at the proximal
end) so
that compression from the bilateral lever arms via their pegs does not impede
the movement
of the sliding inner guard 205. Indeed, this geometry aids in the forward
protrusion of the
sliding guard and assists the safety features. At the most proximal extent of
the receiver
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WO 2004/080274 PCT/US2004/003370
grooves is a deeper peg seal 207f. When the lever arm pegs bilaterally seat
into these
depressions, the distal protrusion of the sliding inner guard 205 is held
firmly in place. When
this occurs, the operator will feel the seating motion through the fingers,
thus confirming
guard activation. The depth and size of the receiver grooves can be variable,
but must not
significantly compromise the flow of fluid through the needle lumen. The axial
length of the
receiver groove slot corresponds to the travel length of the sliding inner
guard.
A further embodiment of the invention is designed to increase the dilating
forces of
the outer sleeve 204 by the addition of a larger surface area at the distal
end 210c (Figure 33).
This larger surface area may be created by thickening the wall of the outer
sleeve. The
proximal extent of this thickened wall is denoted as 21 Of. Although the inner
guard lumen is
somewhat narrowed, it is still adequate for the passage of fluids 210e. The
cutting edge 204a
is of the same relative geometry to the sliding inner guard as the first
embodiment, but the
cutting blade, itself, may be made as a solid, flat piece of metal without an
internal window
204b. The line denoted 210b (Fig. 39) shows the proximal extent of this
cutting blade. The
blade may be securely fixed the outer sleeve at the area denoted 210d.
The sliding inner guard of the second embodiment retains the same relative
geometry
to the cutting edge as described earlier in the invention. The most distal tip
212a of the guard
may have a semi-conical shape, convex to the outside (Figure 34~). The guard
tip 212a may
also be of a more squared shape, depending on its application. The flow of
fluid through the
tip of the device is augmented by greatly enlarging the defect in the guard
tip and reducing
the support of the guard tip to two bilateral, parallel rails or posts. The
argxple cornmunication
between the inner guard lumen and large guard defects is demonstrated in the
rotated axial
side view of the sliding inner guard tip. The distal extent of the defect is
denoted by the line
213a (Figure 35).
A side axial view of the assembled an additional embodiment is shown (Figure
34).
When the guard is fully extended, it is apparent that there is ample space
through the distal tip
for the flow of fluid 212b, yet there is a large area of the outer cutting
sheath 210c for the
creation of expansive forces separate from the sliding inner guard. A rotated
axial side view
of the extended guard of this additional embodiment (Figure 37) demonstrates
how the
sliding inner guard 212a covers and protects the cutting blade 210a, and is
separated from the
dilating forces created by the outer sleeve surface 210c.
A further embodiment (Figure 38) of the invention further augments the
dilating
forces of the outer sleeve 204. The distal end of the sleeve has plurality of
distally tapering
flanges 216a (Figures 38-40) to help shield the blade 210a. These flanges
parallel the cutting
19
CA 02518043 2005-09-02
WO 2004/080274 PCT/US2004/003370
blade 204a, yet provide adequate space for the egress of the sliding inner
guard. These
flanges create virtually all the dilating forces required for entry of the
device into the
substance of the tissue (or other medium being penetrated). This allows the
sliding inner
guard to move distally without any significant frictional forces on said
guard. Once a space
or potential space is reached by the distal tip of the device, the sliding
inner guard extends
distally into the position denoted (Figure 40). This allows exposure of the
guard defect 212b
and thereby creates an adequate channel for the passage of fluid through the
device. An
axially rotated view of the assembled device (Figure 41) further shows the
relationship of the
components and the distal extent of the inner guard defect channel 213a
distally past the
dilating flanges.
An additional embodiment of the device is shown (Figure 42). This embodiment
combines aspects of both the second and third versions described above. In
this version, the
distal dilating flanges are thickened into a more conical shape 220a with a
thicker base. This
thickened, stronger flange would be supported by the thickened walls of the
outer sleeve 204
that terminate at 210f, yet allow for fluid flow through the lumen 10e. The
flanges 220a may
be perforated 220b in a manner that facilitates flow of fluids through the tip
of the device.
The needle device may be fitted with an optional guard locking mechanism
(Figure
29). This lock maintains the sliding guard 205 in its extended, blade-covering
position after
penetration of a space or potential space. The lock may be disengaged by
squeezing the lever
arms 207a, allowing the guard to retract proximally, which then allows the
needle to be
ad~ranced through deeper, successive layers of tissue. The operator will have
a tactile
sensation of the lever arms closing as the lever pegs 207c seat in the peg
seats 207f in the
sliding inner guard 205 each time the guard slides distally and locks in
position. In this
manner, the operator can access a desired space or potential space within the
body (e.g., the
epidural space, amniotic cavity, peritoneal cavity, intravascular space, etc.)
in a safe, step by
step, controlled manner.
A modification to each embodiment includes a blade which is somewhat wider
than
the diameter of the outer sleeve 204. This will cut a larger defect in the
tissue (or other
medium being penetrated) and facilitate penetration through strong; dense
tissues (e.g.,
ligaments). This modification may ease the performance of medical procedures
such as
epidural anesthesia.
In the third and fourth embodiments, the shape of the proximal end of the
guard slot
202c between the blade 210a and dilating flange 220a can be variable. The slot
may
terminate as indicated 202d (Figure 42) or may be squared or rounded, for
example.
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Obviously, numerous modifications and variations of the present invention are
possible in light of the above teachings. It is therefore to be understood
that within the scope
of the appended claims, the invention may be practiced otherwise than as
specifically
described herein.
21
