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Claims  |
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What is claimed:
1. A surgical cannula including a hollow steel needle having an elongated
opening therethrough and terminating at a surgical tip at one end thereof,
a first plastic handle member circumferentially mounted on the hollow
steel needle adjacent the other end thereof, a second plastic handle
member removably attached to the first plastic handle member and having an
elongated passageway in alignment with the elongated opening of the hollow
steel needle, said second plastic handle member being removably attached
from the first plastic handle member to facilitate cleaning of the hollow
steel needle and the first and second plastic handle members, and means
for frictionally locking the first and second plastic handle members
relative to one another while simultaneously applying circumferential and
radially inwardly directed gripping pressure through the first plastic
handle member to the hollow steel member to inhibit relative movement
thereof.
2. The surgical cannula as defined in claim 1 wherein the first plastic
handle member includes additional means for longitudinal and
non-rotational mounting relative to the hollow steel needle.
3. The surgical cannula as defined in claim 2 wherein said additional means
includes a complementary molded bonded and tight fitting joint between the
hollow steel needle and the area of the first plastic handle member
circumferentially adjacent the hollow steel needle.
4. The surgical cannula as defined in claim 3 wherein said additional means
further includes longitudinal stop means between the first plastic handle
member and the hollow steel needle.
5. The surgical cannula as defined in claim 1 wherein the first and second
plastic handle members have complementary threaded portions to permit
removable attachment to one another, and cooperating wedge surfaces on
said first and second plastic handle members to create frictional locking
therebetween as they are moved into threaded engagement with one another
while also simultaneously applying circumferential and radially inwardly
directed gripping pressure through the first plastic handle member to the
hollow steel needle.
6. A surgical cannula comprising a hollow steel needle having an elongated
opening therethrough and terminating at a surgical tip at one end thereof,
a first plastic handle member having a complementary longitudinal cavity
for receiving the hollow steel needle therein at its other end, said first
plastic handle member having the plastic material adjacent its
complementary longitudinal cavity circumferentially and complementarily
molded as a bonded and tight fitting joint relative to the hollow steel
needle, said first plastic handle member also including an inner larger
diameter finger gripping section and an outer smaller diameter male
threaded section connected by a longitudinally facing wedging surface, and
a second plastic handle member including an outer finger gripping section
and an elongated passageway in alignment with the elongated opening of the
hollow steel needle, one end of the second plastic handle member being
configured to receive a surgical hose thereon, the other end of the second
plastic handle member being a complementary female threaded section formed
in the elongated longitudinal passageway thereof to receive the outer
smaller diameter male threaded section therein, said second plastic handle
member further being provided with a longitudinally facing outer wedging
surface in longitudinal alignment with the wedging surface of the first
plastic handle member, said first and second plastic handle members being
threadably connected to one another to bring the aligned wedging surfaces
into cooperating engagement with one another causing frictional locking
engagement between the first and second plastic handle members while also
simultaneously applying circumferential and radially inwardly directed
pressure through the male threaded section of the first plastic handle
member around the hollow steel needle.
7. A surgical cannula including a hollow steel needle having an elongated
opening therethrough and terminating at a surgical tip at one end thereof,
a first plastic handle member circumferentially mounted on the hollow
steel needle adjacent the other end thereof, a second plastic handle
member removably attached to the first plastic handle member and having an
elongated passageway in alignment with the elongated opening of the hollow
steel needle, and means for releasably locking the first and second
plastic handle members relative to one another as said first and second
plastic handle members are moved into and out of contact with one another,
said first plastic handle member having a finger depression therein which
is transversely aligned relative to side openings at the surgical tip of
the hollow steel needle.
8. The surgical cannula as defined in claim 7 wherein the means for
releasably locking the first and second plastic handle members to each
other includes frictional locking means.
9. The surgical cannula as defined in claim 8 and including a complementary
molded bonded and tight fitting joint between the hollow steel needle and
an area of the first plastic handle member circumferentially adjacent the
hollow steel needle.
10. The surgical cannula as defined in claim 8 wherein said frictional
locking means comprises longitudinally aligned wedging surfaces on said
first and second plastic handle members.
11. A surgical cannula including a hollow steel needle having an elongated
opening therethrough and terminating at a surgical tip at one end thereof,
a first plastic handle member circumferentially mounted on the hollow
steel needle adjacent the other end thereof, a second plastic handle
member removably attached to the first plastic handle member and having an
elongated passageway in alignment with the elongated opening of the hollow
steel needle, and means for releasably locking the first and second
plastic handle members relative to one another as said first and second
plastic handle members are moved into and out of contact with one another,
said means for releasably locking said first and second plastic handle
members includes frictional locking means having longitudinally aligned
wedging surfaces on said first and second plastic handle members.
12. The surgical cannula as defined in claim 11 wherein the first and
second plastic handle members have complementary threaded portions, and
said longitudinally aligned wedging surfaces are frictionally locked
together as they are moved into threaded engagement with one another.
13. The surgical cannula as defined in claim 11 wherein said longitudinally
aligned wedging surfaces are configured, arranged and dimensioned to also
apply circumferential and radially inwardly directed gripping pressure
through the first plastic handle member to the needle.
14. The surgical cannula as defined in claim 11 wherein said first plastic
handle member has a finger receiving depression therein which is
transversely aligned relative to side openings at the surgical tip of the
hollow steel needle.
15. The surgical cannula as defined in claim 14 wherein said second plastic
handle member is complementary mounted relative to surgical tubing. |
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Claims |
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Description |
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BACKGROUND OF THE INVENTION
Sedentary and over-eating habits in the Western world have produced various
regimens to maintain a desired body weight and image. These include
dieting, discipline, exercise and cosmetic surgery. It is known that while
cosmetic surgery won't replace the benefits of dieting, discipline and
exercise, it can enhance and complement those efforts. Thus, for an
overall program to maintain a desired body weight and image, all of the
aforementioned regimens and programs should be considered.
One of the fastest growing methods of cosmetic surgery is known as
lipo-suction. Pioneered in Europe over the last decade, this procedure has
become increasingly popular because it is relatively safe, effective and
affordable, and unlike the other regimens and programs, it is a permanent
means of removing unwanted body fat. The body does not regenerate fat
cells suctioned away through this technique. Still this procedure is not
for everyone because each individual case is different. Yet when warranted
and performed by a skilled surgeon trained and experienced in this
technique, it is an effective method of modifying body proportions to
alter the silhouette.
Lipo-suction surgery involves only a small incision near the fatty area. A
surgical cannula is then inserted, and fat is suctioned away through a
special vacuum. Surgeons performing this procedure must not only be highly
skilled in this technique, but they must possess high stamina and energy
since this procedure, by necessity, requires careful, but numerous
re-positioning of the cannula over a sustained period. Because of the
demand for the surgeon's skill, time and energy in this procedure, the
cannula has been re-designed to remove weight. This has resulted in
cannulas where lighter weight plastic handles have replaced heavier weight
metal cannula handles. While this has helped in providing a lighter and
less cumbersome cannula, there is still a problem with current designs in
that they are difficult to clean after use, thus leaving the potential for
fat to remain in the cannula. When this happens, it creates an un-sterile
surgical environment which, of course is unacceptable. There are various
design attempts to create a cannula which can be opened for cleaning, but
such designs have been less than satisfactory, and they have also not
considered the need for a lightweight and long lasting product, as well.
There has thus been felt a need to develop a new cannula which not only
overcomes existing problems, but is also safe, effective and easy to use
by the skilled surgeon.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a surgical
cannula which is not only safe, effective and easy to use, but which can
also be properly sterilized between uses.
More specifically, it is an object of the present invention to provide a
surgical cannula having the multi-purpose design features of permitting
opening for cleaning, providing locking of component parts when in use,
facilitating manipulation by being lighter and easier to use, while also
being longer lasting than all other previous designs known to date.
These and other objects and advantages of the present invention will become
apparent through the provision of a surgical cannula including a hollow
steel needle and first and second plastic handle members which are
circumferentially mounted adjacent one end of the hollow needle. The first
plastic handle member is mounted in non-rotational and non-shifting
movement relative to the hollow steel needle adjacent one end thereof.
Such mounting is preferably achieved through a complementary molded bonded
and tight fitting joint between the first plastic handle member and the
hollow steel needle. The second plastic handle is removably attached to
the first plastic handle member to facilitate cleaning of the hollow steel
needle and first and second plastic handle members. The construction,
configuration and design of the first and second plastic handle members
also provides frictional locking therebetween, while simultaneously
applying circumferential and radially inwardly directed gripping pressure
through the first plastic handle member to the hollow steel needle to
inhibit movement thereof. In order to fix the first plastic handle member
to the surgical cannula in the non-rotational and non-shifting position
desired, a slightly undersized cavity is provided in the first plastic
member to receive the hollow steel needle in a press fit relationship, and
then the parts are assembled to one another while being relatively rotated
to one another to create frictional heat therebetween to a degree
sufficient to cause re-molding of the first plastic handle member
circumferentially about its complementary cavity such that subsequent
curing enable the first plastic handle member to form a complementary
molded bonded and tight fitting joint relative to the hollow steel needle.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded top plan view showing individual components of the
surgical cannula which is constructed in accordance with the teachings of
the present invention;
FIG. 2 is a partially exploded top plan view similar to FIG. 1, but showing
some of the components of the surgical cannula assembled to one another;
FIG. 3 is a top plan view of the surgical cannula of the present invention
in which all of the components are assembled to one another to provide an
interlocking design for surgical use;
FIG. 4 is a slightly enlarged fragmentary side elevational view of the
surgical cannula shown in FIG. 3;
FIG. 5 is a fragmentary sectional view of the surgical cannula shown in
FIG. 4;
FIG. 6 is an enlarged sectional view of the surgical cannula showing the
method of assembling/disassembling of handle components; and
FIG. 7 is also an enlarged sectional view similar to FIG. 6 which also
shows locking and gripping pressure being applied to and through the
various components of the surgical cannula.
Corresponding reference characters indicate corresponding parts throughout
the several views of the drawings.
DESCRIPTION OF PREFERRED EMBODIMENTS
While the surgical cannula of the present invention has been primarily
designed for use in connection with lipo-suction procedures as described
above, it will be understood by those skilled in the art that the surgical
cannula may be used for other procedures, as may be appropriate.
Referring now to the drawings and first to FIGS. 1-3, it will be seen that
the surgical cannula C of the present invention includes a hollow steel
needle 10 having an elongated opening 12 (See FIGS. 5-7) therethrough,
except at a surgical tip portion located at the frontal end thereof. Side
openings (not shown) are provided at the surgical tip portion 14 to allow
fat cells to be suctioned off through the elongated opening 12 thereof. At
the rear end of the hollow needle 10, there is an enlarged head section 16
which is formed during assembly of components, as will be described.
A second component of the surgical cannula C of the present invention
includes a ferrule or first plastic handle member 30 which is shown in
FIG. 1 prior to assembly to the hollow steel needle 10. When assembled to
the hollow steel needle 10, the ferrule or first plastic handle member 30
is mounted to the rear end thereof, as shown. The third component of the
surgical cannula C includes a gripping or second plastic handle member 50
which can be assembled/disassembled to the first plastic handle member 30
as shown in the drawings.
In order to be useful for long service life under extreme, heavy-duty
conditions, while also providing precision-engineered close tolerances in
molded/machined requirements, the preferred plastic material from which
the first and second plastic handle members 30, 50 are made is a
polycarbonate resin, such as Lexan, which is a polycarbonate resin made by
General Electric. The first and second plastic handle members 30, 50 may
be molded in the final shape shown in the drawings, or may be partially
molded/machined, as desired. Delrin, a DuPont acetal resin, is suitable
for similar reasons.
As shown in the drawings, the first plastic handle member includes an inner
larger diameter finger gripping section 32 and an outer smaller diameter
male threaded section 34 which are connected to one another by a
longitudinally facing wedging surface 36. An oval-shaped depression 38 is
formed in the inner larger diameter finger gripping section 32 to receive
the thumb of the surgeon in using the surgical cannula. The
oval-depression 38, when the first plastic handle member 30 is mounted on
the hollow steel needle 10, is positioned to extend transverse to the side
openings (not shown) at the front end 14 of the hollow steel needle 10, in
order that the side openings (not shown) will extend transverse to the
skin of the patient. Thus, it is important that the first plastic handle
member 30 is mounted in a non-rotational and non-shifting position on the
hollow steel needle 10.
In order to achieve this mounting, the first plastic handle member 30 is
formed with a complementary undersized cavity or opening 40 which extends
longitudinally therethrough for receiving the hollow steel needle 10 in a
press fit relationship thereto. As the hollow steel needle 10 is inserted
into the complementary undersized cavity 40, the hollow steel needle 10
and the first plastic handle member 30 are rotated relative to one another
to create frictional heat therebetween to a degree sufficient to cause
re-molding of the plastic material circumferentially around the
complementary cavity or opening 40. After curing, the plastic material
circumferentially around the complementary cavity or opening 40 of the
first plastic handle member forms a complementary molded bonded and tight
fitting join relative to the hollow steel needle 10. To enhance the bonded
and tight fitting complementary molded joint between these components, the
outer surface of the hollow needle 10 may be roughenend as at 18, by sand
blasting or the like.
When the first plastic handle member 30 is thus assembled and mounted to
the hollow steel needle 10, any shifting movement, such as by rotation or
longitudinal movement of the components, is thereby prevented. This is
important since the oval-depression 38 of the first plastic handle member
30 which receives the physician's thumb must always be transverse to the
side openings (not shown) at the front tip 14 of the hollow steel needle
10 to avoid any possibility for skin damage due to improper postionment of
the side openings (not shown). The hollow steel needle 10, after assembly
to the first plastic handle member 30, may also have its rear end 16
swaged or deformed, as shown in FIGS. 6-7, to engage the rear facing
surface 42 of the first plastic handle member 30. As will be appreciated,
swaging or deforming the rear end 16 of the hollow steel needle 10 into an
enlarged head portion which engages the rear surface 42 of the first
plastic handle member 30, also assists in preventing longitudinal shifting
movement of the components.
Referring now to the second plastic handle member 50, it will be seen that
it has a substantially elongated shape to accomodate gripping thereof by
the physician in using the surgical cannula. Preferably, the outer surface
52 of the second plastic handle member 50 has a knurled or some other type
of roughened surface to enhance the physician's grip, through the
remaining four fingers and palm, while the thumb is received in the oval
opening 38 of the first plastic handle member 30. Similarly, the outer
surface of the first plastic handle member 30 in its inner larger diameter
finger gripping section 32.
The second plastic handle member 50 has an elongated passageway 54
therethrough which is in alignment with the elongated opening 12 of the
hollow steel needle 12 when the components are assembled to one another.
The outer free end 56 is configured to the shape of a male coupling hose
fitting to receive a surgical hose thereon (not shown). The hose (not
shown) is connected to a vacuum source (not shown) which draws air down
the elongated opening 12 and elongated passageway 54 to allow the
lipo-suction procedure, as described above, to be performed. The other end
of the second plastic handle member 50 has a complementary female threaded
section 58 formed in the elongated longitudinal passageway 54 thereof to
receive the outer smaller diameter male threaded section 34 of the first
plastic handle member 30 in threaded engagement therewith. There is also a
longitudinally facing wedging surface 60 in longitudinal alignment with
the wedging surface 36 of the first plastic handle member 30. Preferably,
the wedging surfaces 36 and 60 do not have the same angular inclination,
such that they can enhance frictional locking engagement of the first and
second plastic handle members 30, 50 to one another.
Thus, as the first and second plastic handle members 30, 50 are threadably
engaged with one another, as the wedging surfaces 36, 60 thereof come into
contact with one another as best seen in FIGS. 6-7, the first and second
plastic handle members 30, 50 will be in frictional locking engagement
with one another. As will be understood by those skilled in the art, as
the two non-mating wedging surfaces 36, 60 are forced into engagement,
they will apply an opposing or back pressure force on the threads of the
threaded sections 34,58, thus resisting any unauthorized retrograde
movement of the first and second plastic handle members 30, 50 relative to
one another. It is contemplated that hand tighting pressure will, through
the frictional locking engagement described above, be sufficient to
prevent undesired threaded separation of the first and second plastic
handle members 30, 50, until cleaning is desired. Then, by hand loosening
pressure, the first and second plastic handle members 30, 50 can be
threadably disassembled to facilitae cleaning thereof.
It is to be noted that as the wedging surfaces 36, 60 are forced into
wedging and frictional locking engagement with one another, there is also
simultaneously applied a circumferential and radially inwardly directed
pressure, as indicated by the arrow P in FIG. 7. This pressure P is
circumferentially and radially inwardly directed to the male threaded
section 34 of the first plastic handle member 30, which deforms the
plastic thereof, to also then apply a circumferential and radial gripping
action on the hollow steel needle 10. This provides an additional and
further locking action to inhibit rotational or logitudinal movement of
the components when assembled to one another, as described above.
From the foregoing, it will be seen that the objects of this invention are
achieved and other advantageous results are obtained.
As various changes could be made in the above constructions without
departing from the scope of the invention, it is intended that all matter
contained in the above description or shown in the accompanying drawing
shall be interpreted as illustrative and not in a limiting sense.
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Description |
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